JP2008167565A - Permanent magnet rotary electric machine, its manufacturing method, and automobile equipped with permanent magnet rotary electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a permanent magnet rotary electric machine having excellent characteristics, in the permanent magnet rotary electric machine using a permanent magnet for the surface of a rotor. <P>SOLUTION: A permanent magnet formed by binding magnetic powder by an SiO based material is provided to the surface of the rotor. A precursor of SiO<SB>2</SB>can be a binding agent excellent in wettability to a magnetic material, and therefore the ratio of the magnetic material in the magnet can be increased, while reducing the deterioration in the magnetic characteristics as compared with an epoxy resin used as the binding agent, with excellent characteristics. Furthermore, the permanent magnet can be molded into a complex shape, thereby forming a continuous skew. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a permanent magnet type rotating electrical machine, a method for manufacturing the same, and an automobile equipped with the permanent magnet type rotating electrical machine.

  In recent years, the properties of permanent magnets have improved significantly. A typical high-performance permanent magnet is a sintered magnet manufactured by sintering a rare earth magnet material. Although this sintered magnet has excellent magnetic properties, it requires a manufacturing process for sintering at a high temperature, which is a factor of deterioration in productivity.

  On the other hand, as shown in Patent Document 1, a so-called bonded magnet in which a magnet material is hardened with a thermosetting epoxy resin has been studied. This bonded magnet does not require a manufacturing process for sintering, and can form a complicated shape to some extent.

Japanese Patent Laid-Open No. 11-238640

  However, in a magnet using an epoxy resin as a binder, the ratio of the epoxy resin material to the magnet material is increased, and the ratio of the magnet material used for the magnet is decreased. For this reason, there has been a problem that the magnetic characteristics are deteriorated and the characteristics of the rotating electrical machine are remarkably lowered.

  An object of the present invention is to provide a permanent magnet type rotating electrical machine having good magnetic properties and productivity, a method for manufacturing the same, and an automobile equipped with the permanent magnet type rotating electrical machine.

  The permanent magnet type rotating electrical machine of the present invention is characterized in that a permanent magnet in which a magnetic powder is bound with a SiO-based material is disposed on the surface of a rotor core.

  The method for manufacturing a permanent magnet type rotating electrical machine according to the present invention is a method in which a magnetic powder coated with an inorganic insulating film is pressure-molded, and the pressure-molded body is impregnated with a SiO-based material to produce a permanent magnet. The permanent magnet is fixed to the surface of the rotor core.

  In addition, in an automobile equipped with the permanent magnet type rotating electrical machine of the present invention, a permanent magnet in which magnetic powder is bound with a binder is disposed on the surface of a rotor core, and the binder is a precursor thereof. Is made of a material having good wetting characteristics with respect to the magnetic powder.

  The permanent magnet type rotating electrical machine of the present invention can have good magnetic properties and productivity.

[First embodiment]
FIG. 1 is a configuration diagram showing an embodiment of a hybrid electric vehicle equipped with a permanent magnet type rotating electrical machine as a first embodiment according to the present invention. The rotating electrical machine according to the present invention can be applied to a pure electric vehicle and a hybrid electric vehicle. Examples of the hybrid electric vehicle will be described below.

  The hybrid electric vehicle 100 supplies high-voltage DC power to the engine 120, the first rotating electrical machine 200, the second rotating electrical machine 202, and the first rotating electrical machine 200 and the second rotating electrical machine 202. A battery 180 that receives high-voltage DC power from the first rotating electrical machine 200 and the second rotating electrical machine 202 is mounted. Further, a battery for supplying low voltage power of 14 volt system power is mounted on the vehicle, and low voltage direct current power is supplied to a control circuit described below. Is omitted.

  Rotational torque based on the engine 120, the first rotating electric machine 200, and the second rotating electric machine 202 is transmitted to the transmission 130 and the differential gear 132, and is transmitted to the front wheels 110. A transmission control device 134 that controls the transmission 130, an engine control device 124 that controls the engine 120, a rotating electrical machine control circuit 604 that controls the power converter 600, and a battery control device 184 that controls a battery 180 such as a lithium ion battery, The integrated control device 170 is connected to each other by a communication line 174.

  The integrated control device 170 transmits information indicating the respective states from the transmission control device 134, the engine control device 124, the power conversion device 600, and the battery control device 184, which are lower-level control devices than the integrated control device 170, through the communication line 174. Receive through. Based on these pieces of information, the control command of each control device is calculated by the integrated control device 170, and the control command from the integrated control 170 to each control device is transmitted to each control device via the communication line 174.

  For example, the battery control device 184 reports the discharge status of the battery 180 which is a lithium ion battery and the status of each unit cell battery constituting the lithium ion battery to the integrated control device 170 via the communication line 174 as the status of the battery 180.

If the integrated control device 170 determines from the above report that the battery 180 needs to be charged, it instructs the power conversion device 600 to perform a power generation operation. The integrated control device 170 also manages the output torque of the engine 120 and the first and second rotating electrical machines 200 and 202, and the total torque or torque distribution ratio of the output torque of the engine and the first and second rotating electrical machines 200 and 202. And a control command based on the processing result is transmitted to the transmission control device 134, the engine control device 124, and the power conversion device 600. Based on the torque command, the power conversion device 600 controls the first rotating electric machine 200 and the second rotating electric machine 202, and generates a command torque output or generated electric power with one or both of the rotating electric machines. These rotating electric machines are controlled as follows.

  The power conversion device 600 controls the switching operation of the power semiconductor constituting the inverter in order to operate the first rotating electrical machine 200 and the second rotating electrical machine 202 based on a command from the integrated control device 170. By the switching operation of these power semiconductors, the first rotating electric machine 200 and the second rotating electric machine 202 are operated as an electric motor or a generator.

  When operating as an electric motor, DC power from the high-voltage battery 180 is supplied to the DC terminal of the inverter of the power converter 600. By controlling the switching operation of the power semiconductor constituting the inverter, the supplied DC power is converted into three-phase AC power and supplied to the rotating electrical machine 200 or 202. On the other hand, when the first rotating electrical machine 200 or the second rotating electrical machine 202 is operated as a generator, the rotor of the rotating electrical machine 200 or 202 rotates with a rotational torque applied from the outside, and the rotating electrical machine is based on this rotational torque. Three-phase AC power is generated in the stator winding. The generated three-phase AC power is converted to DC power by the power converter 600, DC power is supplied to the high-voltage battery 180, and the battery 180 is charged with DC power.

  As shown in FIG. 1, a power conversion apparatus 600 includes a plurality of smoothing capacitor modules that suppress voltage fluctuations of a DC power supply, a power module that includes a plurality of power semiconductors, and a switching drive that controls the switching operation of the power module. The rotating electrical machine control circuit includes a circuit and a circuit for generating a signal for determining a time width of the switching operation, that is, a PWM signal for controlling pulse-wide modulation.

  The high voltage battery 180 is a secondary battery such as a lithium ion battery or a nickel metal hydride battery, and a high voltage DC power of 250 to 600 volts or more is charged to the secondary battery, or the secondary battery. Is output from.

FIG. 2 is a circuit diagram of power converter 600 shown in FIG. The power conversion device 600 is provided with a first inverter device for the first rotating electrical machine 200 and a second inverter device for the second rotating electrical machine 202. The first inverter device includes a first drive module 652 that controls the switching operation of each power semiconductor 21 in the first power module 610, the first power module 610, and a current sensor 660 that detects the current of the rotating electrical machine 200. A control circuit 648 used in common with the second inverter device described below, and a transmission / reception circuit 644 and a capacitor module 630 mounted on the connector substrate 642 are provided. Note that the drive circuit 652 is provided on the drive circuit board 650, and the control circuit 648 is provided on the control circuit board 646.

The second inverter device includes a second power module 620, a second drive circuit 656 that controls the switching operation of each power semiconductor 21 in the second power module 620, and a current sensor 662 that detects the current of the rotating electrical machine 202. A control circuit 648, a transmission / reception circuit 644, and a capacitor module 630 that are used in common with the first inverter are provided. The second drive circuit 656 is mounted on the second drive circuit board 654, the control circuit 648 is mounted on the rotating electrical machine control circuit board 646, and the transmission / reception circuit 644 is mounted on the connector board 642.

  The first power module 610 and the second power module 620 operate according to the drive signals output from the corresponding first and second drive circuits 652 and 656, respectively, and are supplied with DC power supplied from the high voltage battery 180. Is converted into three-phase AC power, and the power is supplied to the corresponding armature windings of the rotating electric machines 200 and 202. Also, AC power induced in the stator windings that are the armature windings of the rotating electric machines 200 and 202 is converted into DC and supplied to the high voltage battery.

  The first and second power modules 610 and 620 are each provided with a three-phase bridge circuit as shown in FIG. 2, and series circuits corresponding to the three phases are electrically connected between the positive electrode side and the negative electrode side of the battery 180, respectively. Are connected in parallel. Each series circuit includes a power semiconductor constituting the upper arm and a power semiconductor constituting the lower arm, and the power semiconductor 21 constituting the upper arm and the power semiconductor 21 constituting the lower arm are connected in series.

  As shown in FIG. 2, the first power module 610 and the second power module 620 have substantially the same circuit configuration, and the first power module 610 will be described as a representative. In this circuit, an IGBT (insulated gate bipolar transistor) 21 is used as a switching power semiconductor element. The IGBT 21 includes three electrodes, a collector electrode, an emitter electrode, and a gate electrode. A diode 38 is electrically connected between the collector electrode and the emitter electrode of the IGBT 21. The diode 38 includes two electrodes, a cathode electrode and an anode electrode. The cathode electrode is the collector electrode of the IGBT 21 and the anode electrode is the IGBT 21 so that the direction from the emitter electrode to the collector electrode of the IGBT 21 is the forward direction. Each is electrically connected to the emitter electrode.

  A MOSFET (metal oxide semiconductor field effect transistor) may be used as the power semiconductor element for switching. The MOSFET includes three electrodes, a drain electrode, a source electrode, and a gate electrode. Note that the MOSFET includes a parasitic diode in which the direction from the drain electrode to the source electrode is a forward direction between the source electrode and the drain electrode, so that it is not necessary to provide the diode 38 of FIG.

  The arm of each phase is configured by electrically connecting the source electrode of the IGBT 21 and the drain electrode of the IGBT 21 in series. In this embodiment, only one IGBT for each upper and lower arm of each phase is shown, but since the current capacity to be controlled is large, a plurality of IGBTs are actually connected in parallel. ing. Hereinafter, in order to simplify the description, it will be described as one power semiconductor.

  In the embodiment shown in FIG. 2, each upper and lower arm of each phase is constituted by three IGBTs. The drain electrode of the IGBT 21 in each upper arm of each phase is electrically connected to the positive electrode side of the battery 180, and the source electrode of the IGBT 21 in each lower arm of each phase is electrically connected to the negative electrode side of the battery 180.

  The midpoint of each arm of each phase (the connection portion between the source electrode of the upper arm side IGBT and the drain electrode of the lower arm IGBT) is electrically connected to the armature winding of the corresponding phase of the corresponding rotating electric machine 200 or 202. Connected.

The first and second drive circuits 652 and 656 constitute a drive unit for controlling the corresponding inverter devices 610 and 620, and drive the IGBT 21 based on the control signal output from the control circuit 648. For generating a driving signal. The drive signals generated by the respective drive circuits 652 and 656 are output to the gates of the respective power semiconductors in the corresponding first power module 610 and second power module 620, respectively. Two sets of circuits that generate drive signals to be supplied to the gates of the upper and lower arms of each phase are used as one integrated circuit. Each of the drive circuits 652 and 656 includes six integrated circuits, and the six integrated circuits are accommodated to constitute the drive circuits 652 and 656 as one block.

The control circuit 648 constitutes a control unit of each inverter device 610 and 620, and is constituted by a microcomputer that calculates a control signal (control value) for operating (turning on / off) a plurality of switching power semiconductor elements. ing. The control circuit 648 receives a torque command signal (torque command value) from the host controller, and signals (sensor output) detected by the current sensors 660 and 662 and the rotation sensors mounted on the rotating electrical machines 200 and 202. . The control circuit 648 calculates a control value based on these input signals, and outputs a control signal for controlling the switching timing to the drive circuits 652 and 656.

  The transmission / reception circuit 644 mounted on the connector board 642 is for electrically connecting the power conversion apparatus 600 and an external control apparatus, and communicates information with other apparatuses via the communication line 174 in FIG. Send and receive.

  The capacitor module 630 is for configuring a smoothing circuit for suppressing fluctuations in the DC voltage generated by the switching operation of the IGBT 21, and is connected to a DC side terminal in the first power module 610 or the second power module 620. They are electrically connected in parallel.

FIG. 3 is a cross-sectional view of the rotating electrical machine 200 or 202 shown in FIGS. 1 and 2. The rotating electrical machines 200 and 202 have substantially the same structure, and the structure of the rotating electrical machine 200 will be described with reference to FIGS. 3 to 5 as typical examples thereof. 4 is a cross-sectional view taken along the line AA in FIG. 3. FIG. 4 is a cross-sectional view taken along the line AA in the stator 230 and the rotor 250 in FIG.

A stator 230 is held inside the housing 212, and the stator 230 includes a stator core 232 and a stator winding 238. A rotor 250 is arranged on the inner side surface of the stator core 232 via a gap 222. The rotor 250 includes a rotor core 252 and a permanent magnet 254, and the rotor core 252 is fixed to the shaft 218. The housing 212 has end brackets 214 on both sides in the rotation axis direction of the shaft 218, and the shafts 218 having the rotor core 252 are rotatably held by bearings 216 on the end brackets 214.

The shaft 218 is provided with a rotor position sensor 224 that detects the position of the rotor pole and a rotation speed sensor 226 that detects the rotation speed of the rotor. Outputs from these sensors 224 and 226 are taken into the control circuit 648 shown in FIG. 2, and the power module 610 is controlled based on the outputs of these sensors.

  FIG. 4 is a cross-sectional view of the stator 230 and the rotor 250 shown in FIG. A specific structure of the stator 230 and the rotor 250 shown in FIG. 3 will be described with reference to FIG. The stator 230 has a stator core 232, and the stator core 232 has a large number of slots 234 and teeth 236 equally in the circumferential direction, and distributed winding is provided in the slots 234. 238 is provided. In FIG. 4, teeth 236 and slots 234 are provided on the entire rotor side of the stator. It should be noted that not all of these are provided with reference numerals, and representatively only some of the teeth and slots are assigned reference numerals.

In addition, permanent magnets 254 and 256 are attached to the surface of the rotor core 252 with an adhesive or the like. When careful safety measures are required depending on the application, the permanent magnets 254 and 256 are covered with a non-magnetic material such as a stainless steel tube to prevent the permanent magnets 254 and 256 from being scattered due to the centrifugal force of the magnet. can do. Further, a magnet insertion hole may be provided on the surface side of the rotor core 252 and the permanent magnets 254 and 256 may be mounted in the insertion hole. The magnet acts as a field pole of the rotor 250, and the magnetization directions of the permanent magnets 254 and 256 constituting these field poles are directions in which the stator side surface of the magnet is an N pole or an S pole, and is magnetized for each field pole. The direction is reversed.

Permanent magnets 254 and 256 may be magnetized and affixed to rotor core 252 in the form of permanent magnets, or may be affixed to rotor core 252 while permanent magnets 254 and 256 are not magnetized and rotated. After the child 250 is constructed, it may be magnetized by applying a strong magnetic field to form a permanent magnet. In this case, the permanent magnet 254 that is not magnetized.
The productivity of the rotating electrical machine is improved by attaching 256 to the rotor core 252 and then magnetizing it. That is, these permanent magnets 254 and 256 are very strong magnets. If the magnets are magnetized before the permanent magnets 254 and 256 are fixed to the rotor 250, the permanent magnets 254 and 254 are fixed.
When the 256 is fixed, a strong suction force is generated between the rotor core 252 and this centripetal force hinders work. Moreover, there is a possibility that dust such as iron powder adheres to the permanent magnets 254 and 256 due to the strong attractive force.

  In the embodiment shown in FIG. 4, each magnetic pole, that is, each field magnetic pole is composed of one permanent magnet 254, 256, and the magnetization direction is reversed for each field magnetic pole. In this embodiment, the permanent magnets 254 and 256 have opposite polarities. The magnetic poles of the rotor 250 including the permanent magnets 254 and 256 are arranged at equal intervals in the circumferential direction of the rotor 250, and in this embodiment, there are 8 poles.

  In the embodiment of FIG. 4, the pole pitch τp of the rotor 250 is 45 ° in angle. On the other hand, is smaller. By adjusting this ratio, τm / τp, the harmonic component of the magnetic flux density distribution produced by the rotor can be changed. Thereby, it is possible to adjust the cogging torque, the torque ripple during energization, the waveform of the induced voltage, and the like, which are basic characteristics of the rotating electrical machine.

  FIG. 5 shows a rotating electrical machine that uses a concentrated winding stator instead of the distributed winding stator winding shown in FIGS. Moreover, the same code | symbol has shown the corresponding structure. In the case of the concentrated winding motor as shown in FIG. 5, the magnet width τm can be adjusted in the same manner. In addition, what concentratedly wound the coil around the teeth of the stator as shown in the figure is called concentrated winding here. On the other hand, in the distributed winding, a coil is inserted across the slot. Although only the W-phase winding is shown in FIG. 5, these coils can be connected in series or in parallel to adjust the voltage viewed from the terminals.

  In the embodiment of FIG. 5, on the rotor side, the curvature arc of the magnet surface is made smaller than the radius of the gap surface as shown on the stator side surface of the permanent magnets 254 and 256. Looking at the state of the cross section on the vertical plane of the rotating shaft, each magnet has a shape that faces from the rotor 250 toward the stator 230 at both circumferential ends of the rotor 250, and the side surface of the stator 230 is closer to the rotor 250 surface. A curved shape having a high polarity is formed, and the central portion in the circumferential direction of the magnet is closest to the stator 230.

  With this shape (hereinafter referred to as a kamaboko type), the magnetic flux density on the surface of the magnet on the stator 230 side can be smoothly distributed in a sinusoidal shape in the circumferential direction. Due to this effect, harmonic components can be reduced, cogging torque can be reduced, and harmonics of the waveform of the induced voltage can be reduced. Such a permanent magnet having a kamaboko shape can be easily made by using this embodiment.

  Here, the difference between the permanent magnet used in the present embodiment and the sintered magnet and bond magnet used in the conventional rotating electric machine will be described below.

  Sintered magnets are used in electric vehicles, hybrid vehicles, and the like because the motor can be miniaturized by taking advantage of its high energy density. However, since the sintered magnet is indispensable for high temperature treatment in the sintering process due to its manufacturing method, the production cost including the equipment cost becomes high. In addition, in order to obtain parts with accurate dimensions, the shape and dimensions after the sintering process change due to thermal shrinkage, etc., due to the sintering process in which the magnet material is heated to a high temperature. In the molding process after the sintering process, a molding operation including a large amount of cutting was required to obtain dimensional accuracy. This has led to an increase in the cost of the magnet motor, which is an obstacle to obtaining an inexpensive and good controllable motor.

  The bonded magnet is manufactured by mixing a thermosetting epoxy resin and a magnet material and molding the mixture. That is, it is a magnet obtained by bonding a magnet material with an epoxy resin. In a magnet using an epoxy resin as a binder, a magnet is manufactured by compression molding a mixture of a magnet material and an epoxy resin. Bonded magnets that bond magnet materials with such epoxy resins increase the proportion of the epoxy resin material relative to the magnet material, reduce the proportion of the magnet material to be put on the magnet, have poor magnetic properties, and significantly reduce the properties of the rotating electrical machine. There's a problem. Since such a bond magnet has a low energy density, it is not often used for large capacity and large torque applications, and is used for small fan motors and the like.

  As described above, in order to make such a shape with a sintered magnet, surface processing is required, which increases the cost. Actually, since the sintered magnet is sintered at 1000 ° C. or higher, it is necessary to correct deformation due to thermal shrinkage, and it is indispensable to process it later. Moreover, it is difficult to use an epoxy resin as a binder at a high temperature of 150 ° C. or higher in a bond magnet bonded with an organic substance, and there are many needs for automobiles to be used in a thermal environment exceeding 150 ° C. It was unsuitable for rotating electrical machines in terms of durability.

  The embodiment of the kamaboko magnet shown in FIG. 5 can be applied to the embodiment of FIG. In the embodiment shown in FIG. 4, the permanent magnets 254 and 256 held by the rotor 250 can be changed to the kamaboko-shaped magnet shown in FIG. 5. In the distributed winding motor, the rotating magnetic field generated by the stator can be made smoother than the concentrated winding. In addition to this, the permanent magnet is shaped like a semi-cylindrical shape and placed on the outer periphery of the rotor core, so that the change in magnetic flux density on the stator side surface of the magnet can be made close to a sine wave function. Torque ripple can be reduced. In particular, since low pulsation torque can be generated at low speed rotation, acceleration at the start of the vehicle is smooth, which is suitable for giving the driver a high-class feeling regarding the drivability of the vehicle.

  Such permanent magnets are expensive in the conventional sintered magnet type because of the deformation after the heat treatment and need to be molded. However, in the case of a rotating machine using the permanent magnet of the present invention, if this shape is made with a press die, deformation after press working is reduced, and post-processing of the magnet is not necessary. Alternatively, even if post-processing is necessary, there is an effect that the amount of processing work is small and the processing process is simplified.

  FIG. 6 shows another method of making the rotor 250. The magnet restraint 260 prevents the permanent magnet from scattering due to centrifugal force. The magnet restraint 260 may be integrated with the rotor core 252 or may be fixed to the rotor core 252 later. Moreover, if the magnet restraint 260 is made of a magnetic material, a motor utilizing reluctance torque can be obtained. Since the reluctance torque can be used more often in the distributed winding motor, there is a method in which the stator structure is distributed winding.

  The application object to which the present invention is applied is not fixed to 8 poles. The number of poles of the rotor 250 may be more poles such as 10 poles and 12 poles. Conversely, the number of poles may be small. There are two methods for winding the stator winding: distributed winding and concentrated winding. In the case of a three-phase motor, the number of slots in the distributed winding stator is 3n of the number of poles (n is a natural number). Also, in the case of concentrated winding, if the number of slots of the stator is N and the number of poles is P, it becomes an efficient three-phase motor in the relationship of 2/3 <= P / N <= 4/3, Applicable to any combination. In the concentrated winding motor, since the number of coils on the stator side constituting one pole is small, the stator has a large harmonic component other than the basic synchronization frequency. In particular, there are many lower-order harmonic components than the basic synchronization frequency. For this reason, there are many eddy currents flowing through the permanent magnets on the rotor surface, and measures such as division have been indispensable for conventional motors using sintered magnets. This principle and application examples will be described later. In a magnet having magnetic powder bound with a SiO-based binder described below, since there is a binder as an insulating material between the magnetic powders, the internal resistance of the permanent magnet becomes high and the eddy current is reduced accordingly. . It is also possible to bind using magnetic powder having an insulating film formed on the surface. For this reason, compared with the conventional sintered type magnet, there is little necessity for countermeasures, such as division | segmentation of a permanent magnet, and when a countermeasure is unnecessary, a rotary electric machine can be made cheaply. Moreover, efficiency can be improved with respect to a rotating electrical machine which has not been conventionally taken, and heat can be easily taken because heat generation from the magnet can be reduced.

Here, the permanent magnets 254 and 256 have a structure in which a neodymium (Nd) powder of a rare earth material, which is a magnet material, is bound with a binder having a property that the neodymium (Nd) and the precursor have good wettability. is doing. Here, the precursor having excellent wettability is, for example, alkoxysiloxane or alkoxysilane which is a precursor of SiO ₂ . The neodymium (Nd) powder has a plate-like shape, and the thickness in the X-axis and Y-axis directions is several times larger than the value in the Z-axis direction, which is the height direction. I am doing. The size of neodymium (Nd) powder in the X-axis or Y-axis direction should be large. For example, it is better to use powder whose size in the X-axis or Y-axis direction is 45 μm or more. Improve residual properties. It becomes fine because the powder of neodymium (Nd) breaks during molding, and it is difficult to mix small-sized powder, but it is desirable that more than half of the powder is a powder having a size of 45 μm or more, Furthermore, more preferable results can be obtained when 70% or more is a powder having a size of 45 μm or more. Even more preferable results can be obtained when 90% or more is a powder having a size of 45 μm or more. If neodymium (Nd) further contains dysprosium (Dy), the characteristics are improved. By including this dysprosium (Dy), good magnetic properties are maintained even if the temperature of the rotating electrical machine rises. The content of dysprosium (Dy) is about several percent, and at most 10%. Details of a magnet having a structure in which a rare earth magnet material powder is bound with a binder and a method of manufacturing the magnet will be described later.

  3 and 4, the first drive circuit 652 shown in FIG. 2 generates a control signal for controlling the first power module 610 based on the outputs of the rotation speed sensor 226 and the rotor position sensor 224 of the rotor. To the first power module 610. The first power module performs a switching operation based on the control signal, and converts the DC power supplied from the battery 180 into three-phase AC power. This three-phase AC power is supplied to the stator winding 238 shown in FIGS. 3 and 4, and the frequency of the three-phase AC current is controlled based on the detection value of the rotation speed sensor 226, and the detection value of the rotor position sensor 224. Is used to control the phase of the three-phase alternating current with respect to the rotor.

A rotating magnetic field having the above phase and frequency is generated in the stator 230 by a three-phase alternating current. The rotating magnetic field of the stator 230 acts on the permanent magnets 254 and 256 of the rotor 250, and magnet torque based on the permanent magnets 254 and 256 is generated in the rotor 250.

  Next, a method for manufacturing the permanent magnets 254 and 256 will be described. In FIG. 7, an example of the manufacturing process of the permanent magnets 254 and 256 which concern on this embodiment is shown. In step 10, a powdered magnet material is generated. For example, rare earth magnet magnetic powders can be produced by quenching a mother alloy with an adjusted composition.

  In step 15, the powdery magnet material is compression molded. For example, when manufacturing a permanent magnet for use in a rotating electrical machine, in this step 15, a final magnet-shaped mold for the permanent magnet used in the rotating electrical machine is used, and a powdered magnet material is supplied to the mold and compression molded. . The compression-molded magnet material is in a porous state whose shape is determined by a mold, has a low mechanical strength, and is broken when subjected to a strong impact. Moreover, since it is not magnetized, it does not have the characteristics as a permanent magnet. Even if magnetized in this compression-molded state, it is difficult in mechanical strength to be used as a component of a rotating electric machine.

  The compression-molded magnet uses the manufacturing method described in detail below, so that the dimensional relationship of the magnet shape does not change much in the subsequent steps. That is, the shape compression-molded in step 15 can be maintained with high accuracy. For example, when the following manufacturing process is used, it may be necessary to cut and mold a part such as a burr of the binder that binds the magnet material, but many parts of the shape are maintained with high accuracy. Is likely to achieve the required magnet accuracy.

  In sintered magnets, it is necessary to heat the compression-molded magnet material to a high temperature in the manufacturing process, and there is a problem that the shape of the magnet is deformed from the shape of the compression-molding by cooling after heating to a high temperature. . For this reason, in the conventional sintered magnet, in order to maintain the precision of a final shape, cutting was essential. As a result, there is a problem that productivity is deteriorated. In addition, it is difficult to process a curved shape by cutting, and a magnet having a curved shape cannot be easily produced.

In step 20, the compression-molded magnet molded body is impregnated with a SiO ₂ precursor solution. The compression-molded magnet compact is in a porous state, impregnated with a binder precursor having a low viscosity and good wettability with respect to the magnet material. Since the precursor has good wettability and low viscosity with respect to the compression-molded magnet molded body, it is impregnated so that the precursor is sucked into the porous compression molded body. Specific precursors are described in detail below.

  By impregnating a precursor solution of a binder that has good wettability with respect to the magnet compact, the binder covers the surface of each magnetic powder constituting the magnet compact, resulting in a large number of powders. It works to join together. Further, since the precursor solution of the binder enters into the details of the magnet molded body due to the action of good wettability, a good binding effect can be obtained with a small amount of binder. In addition, the use of good wettability makes the equipment relatively simple and inexpensive compared to the use of epoxy resin. Further, since the precursor described in detail below is cured at a relatively low temperature, a final magnet can be obtained while maintaining the size and shape of the compression molded body with high accuracy. Of course, burr of the binder can be made in the step of impregnating the precursor, but since the size and shape of the compacted compact of the powder magnet do not change, the magnet is manufactured by cutting the binder. The

Step 25 is a step of binding the magnet material with the binder by heat-treating the impregnated compression molded body. As described in detail below, a good magnet can be obtained by binding a magnet material using SiO ₂ as a SiO-based material as a binder. As will be described in detail below, the treatment temperature in step 25 is a relatively low temperature, and the shape and dimensions of the magnet molded body are hardly changed by this heat treatment. High accuracy is maintained with respect to the compression-molded shape and dimensions.

Next, the binder for the permanent magnets 254 and 256 will be described. The binder precursor solution used in the step 20 has an alkoxysiloxane and an alkoxysilane, which are SiO ₂ precursors, and has terminal groups and side chains as shown in Chemical Formula 1 and Chemical Formula 2. It has a compound having an alkoxy group.

  Further, the alcohol of the solvent is preferably a compound having the same skeleton as the alkoxy group in alkoxysiloxane or alkoxysilane, but is not limited thereto. Specific examples include methanol, ethanol, propanol, isopropanol and the like. The catalyst for hydrolysis and dehydration condensation may be any of an acid catalyst, a base catalyst, and a neutral catalyst, but the neutral catalyst is most preferable because corrosion of the metal can be minimized. As the neutral catalyst, an organotin catalyst is effective. Specifically, bis (2-ethylhexanoate) tin, n-butyltris (2-ethylhexanoate) tin, di-n-butylbis (2-ethyl) Hexanoate) tin, di-n-butylbis (2,4-pentanedionate) tin, di-n-butyl dilauryl tin, dimethyl dineodecanoate tin, dioctyl dilarylate tin, dioctyl dineodecano Examples include, but are not limited to, ate tin. Examples of the acid catalyst include dilute hydrochloric acid, dilute sulfuric acid, dilute nitric acid, formic acid, acetic acid, and the like, and examples of the base catalyst include sodium hydroxide, potassium hydroxide, aqueous ammonia, and the like, but are not limited thereto.

The total content of alkoxysiloxane, alkoxysilane, hydrolysis product thereof, and dehydration condensate thereof, which is a precursor of SiO _{2 in} the binder solution, is preferably 5 vol% or more and 96 vol% or less. When the total content of alkoxysiloxane, alkoxysilane, its hydrolysis product, and its dehydration condensate is less than 5 vol%, the binder content in the magnet is low. The strength of is slightly reduced. On the other hand, alkoxysiloxane, alkoxysilane, hydrolysis product thereof, and when the content of dehydrated condensates total is more than 96 vol%, alkoxysiloxane that is a precursor of SiO _2, the fast reaction of the molecular weight of the alkoxysilane Therefore, the thickening speed of the binder solution is also increased. This means that it is more difficult to control the proper viscosity of the binder solution, and it becomes more difficult to use this binder solution for the impregnation method than the materials described above.

Hydroxylation shown in the following chemical formula 3 and chemical formula 4 occurs between alkoxysiloxane or alkoxysilane, which is a precursor of SiO _{2 in} the binder solution, and water. Here, the chemical reaction formula is a reaction formula when hydrolysis partially occurs.

At this time, the amount of water added is one of the factors governing the progress of the hydrolysis reaction of alkoxysiloxane or alkoxysilane. This hydrolysis reaction is important for increasing the mechanical strength of the binder after curing. This is because if the hydrolysis reaction of alkoxysiloxane or alkoxysilane does not occur, the dehydration condensation reaction between the alkoxysiloxane or alkoxysilane hydrolysis reaction products that occurs next does not proceed. This is because the dehydration condensation reaction product is SiO ₂ , and this SiO ₂ has high adhesiveness with magnetic powder and becomes an important material for increasing the mechanical strength of the binder. Furthermore, the OH group of silanol has a strong interaction with the O atom or OH group on the surface of the magnetic powder and contributes to high adhesion. However, when the hydrolysis reaction proceeds and the concentration of silanol groups increases, dehydration condensation reaction between organosilicon compounds containing silanol groups (alkoxysiloxane or alkoxysilane hydrolysis products) proceeds, and the molecular weight of the organosilicon compounds increases. The viscosity of the binder solution increases. This is a characteristic that an appropriate state of the binder solution used in the impregnation method is not suitable. Accordingly, it is necessary to add an appropriate amount of water to the alkoxysiloxane or alkoxysilane that is the precursor of SiO _{2 in} the binder solution. Here, the addition amount of water in the insulating layer forming treatment liquid is preferably 1/10 to 1 of the reaction equivalent in the hydrolysis reaction shown in the chemical reaction formulas 1 and 2. When the amount of water added is 1/10 or less of the reaction equivalent in the hydrolysis reaction shown in Chemical Reaction Formulas 1 and 2, since the concentration of silanol groups in the organosilicon compound is low, the organosilicon compound containing silanol groups and the magnetic powder surface low interaction, but also because the alkoxy group in the product for dehydration condensation reaction is hard to occur to produce SiO ₂ is that a large amount of remaining defect is generated number in SiO _2, the strength of the SiO ₂ is low Become. On the other hand, if the amount of water added is greater than 1 of the reaction equivalent in the hydrolysis reaction shown in Chemical Reaction Formulas 1 and 2, the organosilicon compound containing silanol groups is likely to undergo dehydration condensation and the binder solution increases. Since it is viscous, the binder solution cannot penetrate into the gap between the magnetic powder and the magnetic powder, and the binder solution used in the impregnation method has a characteristic of moving away from an appropriate state. Alcohol is usually used as the solvent in the binder solution. This is because the alkoxy group in the alkoxysiloxane has a fast dissociation reaction in the solvent used for the binder solution, and is in equilibrium with the solvent alcohol. Therefore, methanol, ethanol, n-propanol, and iso-propanol having a boiling point lower than that of water and low viscosity are preferred as the solvent alcohol. However, although the stability of the solution is slightly decreased chemically, the viscosity of the binder solution does not increase in a few hours and the solvent of the present invention has a lower boiling point than water. Any water-soluble solvent such as ketones such as acetone can be used.

  Next, another manufacturing method of the permanent magnets 254 and 256 will be described. Another embodiment of the magnet manufacturing process according to the present invention is shown in FIGS. The embodiment shown in FIG. 8 is different from the process shown in FIG. 7 described above in that a step of applying a process of forming an insulating film after generating a powdered magnet material and before compression molding is added. Further, FIG. 9 is different in that the compression-molded magnet is attached to the rotor, and thereafter the treatment of impregnating the binder is performed.

  In FIG. 8, the same process numbers as those in FIG. 7 indicate substantially the same processing contents. In step 10, a powdered magnet material is generated, and an electrical insulating film is formed on the surface of each powder of the magnet material generated in step 12. It is desirable to make an electrical insulating layer as uniform as possible on the entire surface of the magnetic powder as much as possible, and a specific treatment method will be described later. When the manufactured magnet is used for a rotating electrical machine, it is used in an alternating magnetic field as described above. The magnetic flux passing through the magnet changes periodically, and an eddy current is generated in the magnet due to the change of the magnetic flux. This eddy current has a problem of lowering the efficiency of the rotating electrical machine, and there is a risk of increasing heat generation in the magnet due to the eddy current. By covering the surface of each powder in the magnet material with an insulating layer, this eddy current can be suppressed, and a reduction in efficiency of the rotating electrical machine can be suppressed. Further, if the magnet generates heat, the heating of the rotating electrical machine can be suppressed. In particular, in the magnet built in the rotor, the rotor is mechanically connected to the rotating electrical machine housing through a bearing, and the thermal conductivity is not good. For this reason, it is important to suppress the heat generation of the magnet.

When magnets are used under the condition that AC magnetic flux containing harmonics is applied to the magnets, the rare earth magnet material has a low electrical resistance and the surface of the rare earth magnet powder from the viewpoint of suppressing eddy current and heat generation. It is preferable that an inorganic insulating film is formed. In order to form an inorganic insulating film on the surface of the rare earth magnet powder, a phosphate chemical conversion film is preferably applied as the inorganic insulating film. When phosphoric acid, magnesium, or boric acid is used for the phosphating solution, the following composition is good. Phosphorus acid content is desirably 1~163g / dm ^3, cause a decrease in 163 g / dm ³ larger than the magnetic flux density, smaller and insulating 1 g / dm ³ is deteriorated. The amount of boric acid is preferably 0.05 to 0.4 g per 1 g of phosphoric acid, and if it exceeds this range, the stability of the insulating layer is deteriorated. In order to form the insulating layer as uniformly as possible on the entire surface of the magnetic powder, it is effective to improve the wettability of the insulating layer forming treatment liquid to the magnetic powder. For this, addition of a surfactant is desirable. Examples of such surfactants include perfluoroalkyl-based, alkylbenzenesulfonic acid-based, zwitterionic-based, or polyether-based surfactants, and the amount added is 0.01 in the insulating layer forming treatment liquid. If it is less than 0.01% by weight, the effect of lowering the surface tension and wetting the surface of the magnetic powder is insufficient, and if it exceeds 1% by weight, no further effect can be expected and it is uneconomical. It is.

Further, it is desirable to add a rust preventive agent from the viewpoint of preventing deterioration of the characteristics of the magnet. The amount of rust inhibitor is desirably 0.01~0.5mol / dm ^3, 0.01mol / dm difficult suppression of rust surface of the magnetic powder is less than ^3, 0.5 mol / dm more than ³ more than the effect Is not economical because it cannot be expected.

  The addition amount of the phosphating solution depends on the average particle size of the rare earth magnet magnetic powder. When the average particle size of the rare earth magnet magnetic powder is 0.1 to 500 μm, 300 to 25 ml is desirable for 1 kg of the rare earth magnet magnetic powder. If the amount exceeds 300 ml, the insulating film on the surface of the magnetic powder becomes too thick, and rust is likely to occur, leading to a decrease in magnetic flux density at the time of magnet production. As a result, the amount of rust generated increases, which may cause deterioration of the magnet characteristics.

  The rare earth fluoride or alkaline earth metal fluoride in the coating film forming treatment liquid swells in a solvent mainly composed of alcohol. The rare earth fluoride or alkaline earth metal fluoride gel has a gelatinous flexible structure. This is because alcohol has excellent wettability with respect to rare earth magnet magnetic powder. Also, the average particle size of the rare earth fluoride or alkaline earth metal fluoride in the gel state must be pulverized to a level of 10 μm or less because the coating film formed on the surface of the rare earth magnet magnetic powder has a uniform thickness. It is easy. Furthermore, by using a solvent containing alcohol as a main component, it is possible to suppress the oxidation of rare earth magnet magnetic powder that is very easily oxidized.

Furthermore, a fluoride coat film is desirable as the inorganic insulating film for the purpose of improving the insulating properties and magnetic characteristics of the magnetic powder. For this reason, when a fluoride coating film is formed on the surface of rare earth magnet powder, the concentration of rare earth fluoride or alkaline earth metal fluoride in the fluoride coating film forming solution is formed on the surface of the magnetic powder for rare earth magnets. Depending on the film thickness, the rare earth fluoride or alkaline earth metal fluoride is swollen in a solvent mainly composed of alcohol, and the average particle diameter of the rare earth fluoride or alkaline earth metal fluoride in a gel state Is preferably pulverized to a level of 10 μm or less and dispersed in a solvent containing alcohol as a main component. The concentration of rare earth fluoride or alkaline earth metal fluoride is 200 g / dm ³ to 1 g / dm. ³

  The addition amount of the rare earth fluoride coating film forming treatment liquid depends on the average particle diameter of the rare earth magnet magnetic powder. When the average particle diameter of the rare earth magnet magnetic powder is 0.1 to 500 μm, 300 to 10 ml is desirable for 1 kg of the rare earth magnet magnetic powder. This is because if the amount of the treatment liquid is large, not only it takes time to remove the solvent, but also the magnetic powder for rare earth magnets is easily corroded. On the other hand, when the amount of the processing liquid is small, a portion where the processing liquid does not get wet occurs on the surface of the rare earth magnet magnetic powder. Regarding the above matters, Table 1 summarizes the effective concentrations and the like of the treatment liquid for rare earth fluoride and alkaline earth metal fluoride coating films.

  In the process of FIG. 8, in step 12, an insulating film is formed on the surface of each powder in the rare earth magnet material, and in step 15, the magnet material is compression molded to form a porous magnet. Thereafter, the precursor of the binder is impregnated in step 20 as in FIG. 7, and the precursor is cured in step 25 to bind the magnet material with the binder.

The example of the magnet manufacturing process according to the present invention has been described above with reference to FIGS. FIG. 9 shows a rotary electric machine having a magnet insertion hole for inserting a permanent magnet on the outer peripheral surface side of the rotor, and a porous magnet compression-molded before the binder impregnation step is used as the rotor magnet insertion hole. In this method, the binder precursor is then poured into the magnet insertion hole and impregnated. The processes up to step 15 are the same as those already described. In step 17, a porous compressed magnet is inserted into the magnet insertion hole provided in the rotor core, and the SiO ₂ precursor solution is poured into the rotor magnet insertion hole in step magnet 22.

  Next, in step 27, when the temperature of the rotor itself is raised, the precursor is cured, the strength of the compression-molded magnet is increased, and the magnet is fixed in the magnet insertion hole of the rotor core.

  As mentioned above, although the example of the magnet manufacturing process which concerns on this invention was described, the Example of a specific permanent magnet is described below.

[Example 1 of permanent magnet]
In this example, magnetic powder obtained by pulverizing a NdFeB-based ribbon produced by rapidly cooling a mother alloy having an adjusted composition was used as the rare earth magnet magnetic powder. NdFeB master alloy is iron,
Nd is mixed with Fe-B alloy (ferroboron) and dissolved in a vacuum or in an inert gas or reducing gas atmosphere to make the composition uniform. If necessary, the master alloy cut by a single roll or twin roll method is used, and the master alloy dissolved on the surface of the rotating roll is injected and quenched in an inert or reducing gas atmosphere such as argon gas. After forming the ribbon, heat treatment is performed in an inert gas or a reducing gas atmosphere. The heat treatment temperature is 200 ° C. or more and 700 ° C. or less, and Nd ₂ Fe ₁₄ B microcrystals grow by this heat treatment. The ribbon is 10-100
The thickness is μm, and the crystallite size of Nd ₂ Fe ₁₄ B is 10 to 100 nm.

When the Nd ₂ Fe ₁₄ B microcrystals have an average size of 30 nm, the grain boundary layer has a composition close to that of Nd ₇₀ Fe ₃₀ and is thinner than the single domain critical grain size, so that the inside of the Nd ₂ Fe ₁₄ B microcrystals It is difficult to form a domain wall. The magnetizations of Nd ₂ Fe ₁₄ B microcrystals are magnetically coupled in the respective microcrystals, and it is presumed that the magnetization reversal is caused by propagation of the domain wall. One technique for suppressing magnetization reversal is to facilitate magnetic coupling between magnetic powders obtained by pulverizing a ribbon. For this purpose, it is effective to make the nonmagnetic part between magnetic powders as thin as possible. The pulverized powder is inserted into a WC carbide mold to which Co is added and then compression molded with a top and bottom punch at a press pressure of 5t-20t / cm ^2. There are few nonmagnetic parts between magnetic particles in the direction perpendicular to the pressing direction. Since the magnetic powder is a flat powder obtained by pulverizing a ribbon, anisotropy occurs in the arrangement of the flat powder in a compression molded product, and the long axis of the flat powder (thickness of the ribbon) is perpendicular to the pressing direction. (Parallel to the direction perpendicular to the direction). As a result of the long axis direction of the flat powder being easily oriented in the direction perpendicular to the press direction, the magnetization direction is reversed in the vertical direction of the formed body because the magnetization is continuous in the vertical direction and the permeance is greater in each powder. It becomes difficult to do. For this reason, a difference occurs in the demagnetization curve between the pressing direction of the compact and the direction perpendicular to the pressing direction. When a 10 × 10 × 10 mm compact is magnetized at 20 kOe in the direction perpendicular to the press direction and the demagnetization curve is measured, the residual magnetic flux density (Br) is 0.64 T and the coercive force (iHc) is 12.1 kOe. On the other hand, when magnetized with a magnetic field of 20 kOe in the direction parallel to the press direction, the demagnetization curve was measured in the magnetization direction to be Br 0.60 T and iHc 11.8 kOe. This difference in demagnetization curve is considered to be caused by the fact that flat powder is used for the magnetic powder used in the molded body, and the orientation of the flat powder has anisotropy in the molded body. It is done.

This difference in demagnetization curve is considered to be caused by the fact that flat powder is used for the magnetic powder used in the molded body, and the orientation of the flat powder has anisotropy in the molded body. It is done. The crystal grains of each flat powder are as small as 10-100 nm and the crystal orientation is small, but the shape of the flat powder has anisotropy. Is magnetically anisotropic. The test piece of such a molded body was impregnated with the following SiO ₂ precursor solutions 1) to 3) and heat-treated. The implemented process is demonstrated below.

The following three solutions were used for the SiO ₂ precursor as a binder.

1) 5 ml of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, average is 4), 0.96 ml of water, 95 ml of dehydrated methyl alcohol, dibutyltin dilaurate 0 0.05 ml was mixed and left at a temperature of 25 ° C. for 2 days and nights.

_{2) CH 3 O- (Si (} CH 3 O) 2 -O) m -CH 3 (m is 3-5, average 4) 25 ml, water 4.8 ml, dehydrated methanol 75 ml, dibutyltin dilaurate 0 0.05 ml was mixed and left at a temperature of 25 ° C. for 2 days and nights.

_{3) CH 3 O- (Si (} CH 3 O) 2 -O) m -CH 3 (m is 3-5, average 4) 100 ml, water 3.84 ml, dibutyltin dilaurate 0.05ml were mixed It was left at a temperature of 25 ° C. for 4 hours.

The viscosities of the SiO ₂ precursor solutions 1) to 3) were measured at a temperature of 30 ° C. using an Ostwald viscometer.

(1) The above Nd ₂ Fe ₁₄ B magnetic powder is filled in a mold, and a test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm is used for measuring magnetic properties at a pressure of 16 t / cm ² . A compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm was prepared.

(2) The compression molded test piece prepared in (1) is placed in the bat so that the pressing direction is horizontal, and the SiO ₂ precursor solution of 1) to 3) as the binder is placed in the bat. Injection was performed so that the liquid level was 1 mm / min in the vertical direction. The SiO ₂ precursor solution was poured into the vat until it was finally 5 mm above the upper surface of the compression molded specimen.

(3) The compression-molded test piece used in (2) was placed, and the bat filled with the SiO ₂ precursor solution was set in a vacuum vessel and gradually exhausted to about 80 Pa. The sample was left until the generation of bubbles from the surface of the compression molded test piece was reduced.

(4) The compression molded test piece was placed, the internal pressure of the vacuum vessel in which the bat filled with the SiO ₂ precursor solution was set was gradually returned to atmospheric pressure, and the compression molded test piece was taken out from the SiO ₂ precursor solution. .

(5) The compression molding test piece impregnated with the SiO ₂ precursor solution prepared in (4) is set in a vacuum drying furnace, and vacuum is applied to the compression molding test piece under the conditions of 1 to 3 Pa and 150 ° C. Heat treatment was applied.

  (6) The specific resistance was measured by the four-probe method for the compression molded test piece of 10 mm length, 10 mm width, and 5 mm thickness produced in (5).

  (7) Further, a pulse magnetic field of 30 kOe or more was applied to the compression molded test piece whose specific resistance was examined. The compression molded specimen was examined for magnetic properties.

  (8) A mechanical bending test was carried out using the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (5). For the bending test, a compression molded body having a sample shape of 15 mm × 10 mm × 2 mm was used, and the bending strength was evaluated by a three-point bending test with a distance between supporting points of 12 mm.

FIG. 10 shows an example of SEM observation results of the cross-sectional portion of a compression molded test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm produced in (5). 10A is a secondary electron image, FIG. 10B is an oxygen surface analysis image, and FIG. 10C is a silicon surface analysis image. As shown to (a), the flat powder has accumulated with anisotropy and the crack has generate | occur | produced partially. Further, oxygen and silicon are detected along the surface of the flat powder and the cracks inside the flat powder. This crack is generated at the time of compression molding and is a cavity before the impregnation treatment. From this, it was found that the SiO ₂ precursor solution was impregnated into the cracks in the magnetic powder.

Regarding the magnetic properties of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (5), the residual magnetic flux density can be improved by 20-30% compared to the resin-containing bond magnet (Comparative Example 1). in and, 20 ° C. demagnetization curve measured at (invention confirmation necessity to have) the value of residual magnetic flux density and coercivity and SiO ₂ before impregnated and molded body after SiO ₂ infiltration and heating were almost the same. In addition, the thermal demagnetization rate after 1 hour holding in the atmosphere at 200 ° C. (need to be confirmed by the inventor) is 3.0% for the SiO ₂ impregnated bonded magnet, which is higher than the thermal demagnetization factor without SiO ₂ impregnation (5%). small. Furthermore, the irreversible thermal demagnetization rate after returning to room temperature after 1 hour at 200 ° C (requires confirmation by the inventor) is less than 1% when impregnated, whereas an epoxy bond magnet (comparative example) 1) The value was close to 3%. This is because the surface of the powder containing cracks is protected by SiO ₂ by the impregnation treatment, so that corrosion such as oxidation is suppressed and the irreversible thermal demagnetization rate is reduced. That is, since the surface of the powder including cracks is protected by the impregnation treatment with the SiO ₂ precursor, corrosion such as oxidation is suppressed, and the irreversible thermal demagnetization rate is reduced. In addition to suppressing irreversible thermal demagnetization, the impregnated magnet has obtained less demagnetization results in the PCT test and the salt spray test.

  Further, the compression molded test piece having a length of 10 mm, a width of 10 mm and a thickness of 5 mm produced in (5) was kept at 225 ° C. for 1 hour in the atmosphere, and after cooling, the demagnetization curve was measured at 20 ° C. The magnetic field application direction was 10 mm. First, after magnetization with a magnetic field of +20 kOe, a demagnetization curve was measured by alternately applying a magnetic field between ± 1 kOe and ± 10 kOe.

The result is shown in FIG. Here, the demagnetization curves of a magnet impregnated under the above condition 2) and a compression-molded bonded magnet containing 15 vol% of an epoxy resin as a binder, which will be described later, are compared. In FIG. 11, the horizontal axis represents the applied magnetic field, and the vertical axis represents the residual magnetic flux density. In the magnet subjected to the impregnation treatment, when a magnetic field larger than −8 kOe is applied to the negative side, the magnetic flux rapidly decreases. The compression-molded bonded magnet has a magnetic field whose value is smaller than that of the impregnated magnet, and the magnetic flux rapidly decreases. The magnetic field on the negative side of −5 kOe is significantly decreased. The residual magnetic flux density after applying a magnetic field of −10 kOe is 0.44 for the impregnated magnet, 0.11 T for the compression molded bond magnet, and the residual magnetic flux density of the impregnated magnet is four times the value of the compression molded magnet. Yes. This is because the magnetic anisotropy of the NdFeB crystals constituting each NdFeB powder is reduced by oxidizing the surface of each NdFeB powder and the crack surface of the NdFeB powder while the compression molded bonded magnet is heated at 225 ° C. This is considered to be because the coercive force decreased and the magnetization was easily reversed by applying a negative magnetic field. On the other hand, in the impregnated magnet, the NdFeB powder and the crack surface are covered with the SiO ₂ film, so that it is considered that the reduction in coercive force is small as a result of preventing oxidation during heating in the atmosphere.

The bending strength of the compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm produced in (7) is ₂ MPa or less before the SiO ₂ impregnation, but after the SiO ₂ impregnation heat treatment, it is 30 MPa or more. ), 3) When the SiO ₂ precursor solution was used, it was possible to produce a magnet molded body having a bending strength of 100 MPa or more.

  The specific resistance of the magnet was about 10 times that of the sintered rare earth magnet, but about 1/10 that of the compressed rare earth bonded magnet. became. However, when used as a rotating electrical machine, the occurrence of eddy current loss is small and there is no problem. In particular, in a rotating electric machine with a built-in magnet, harmonic magnetic flux does not penetrate deeply from the magnetic pole piece 280 of the rotor, so there is little eddy current in the magnet and this is not a big problem.

From the results of this example, the rare earth bonded magnet impregnated in the rare earth magnet molded body produced by the cold forming method without using the low-viscosity SiO ₂ precursor of the present invention is compared with a normal resin-containing rare earth bonded magnet. Thus, it was found that the magnetic characteristics were improved by 20 to 30%, the bending strength was equivalent to 3 times, the irreversible thermal demagnetization rate was reduced to half or less, and the magnet was highly reliable.

  Table 2 summarizes the magnetic characteristics of the present example and [Embodiment 2 of permanent magnet] to [Embodiment 5 of permanent magnet] described later when binders 1) to 3) are used. .

[Example 2 of permanent magnet]
In this example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used for the rare earth magnet magnetic powder. In addition, the following three solutions were used as precursors for the SiO ₂ binder.

1) 25 ml of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, average is 4), 0.96 ml of water, 75 ml of dehydrated methyl alcohol, dibutyltin dilaurate 0 0.05 ml was mixed and left at a temperature of 25 ° C. for 2 days and nights.

_{2) CH 3 O- (Si (} CH 3 O) 2 -O) m -CH 3 (m is 3-5, average 4) 25 ml, water 4.8 ml, dehydrated methanol 75 ml, dibutyltin dilaurate 0 0.05 ml was mixed and left at a temperature of 25 ° C. for 2 days and nights.

_{3) CH 3 O- (Si (} CH 3 O) 2 -O) m -CH 3 (m is 3-5, average 4) 100 ml, water 9.6 ml, dehydrated methanol 75 ml, dibutyltin dilaurate 0 0.05 ml was mixed and left at a temperature of 25 ° C. for 2 days and nights.

The viscosities of the SiO ₂ precursor solutions 1) to 3) were measured at a temperature of 30 ° C. using an Ostwald viscometer.

(1) The above Nd ₂ Fe ₁₄ B magnetic powder is filled in a mold, and a test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm is used for measuring magnetic properties at a pressure of 16 t / cm ² . A compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm was prepared.

(2) The compression molded test piece prepared in (1) is placed in the bat so that the pressing direction is horizontal, and the SiO ₂ precursor solution of 1) to 3) as the binder is placed in the bat. Injection was performed so that the liquid level was 1 mm / min in the vertical direction. The SiO ₂ precursor solution was poured into the vat until it was finally 5 mm above the upper surface of the compression molded specimen.

(3) The compression-molded test piece used in (2) was placed, and the bat filled with the SiO ₂ precursor solution was set in a vacuum vessel and gradually exhausted to about 80 Pa. The sample was left until the generation of bubbles from the surface of the compression molded test piece was reduced.

(4) The compression molded test piece was placed, the internal pressure of the vacuum vessel in which the bat filled with the SiO ₂ precursor solution was set was gradually returned to atmospheric pressure, and the compression molded test piece was taken out from the SiO ₂ precursor solution. .

(5) The compression molding test piece impregnated with the SiO ₂ precursor solution prepared in (4) is set in a vacuum drying furnace, and vacuum is applied to the compression molding test piece under the conditions of 1 to 3 Pa and 150 ° C. Heat treatment was applied.

  (6) The specific resistance was measured by the four-probe method for the compression molded test piece of 10 mm length, 10 mm width, and 5 mm thickness produced in (5).

  (7) Further, a pulse magnetic field of 30 kOe or more was applied to the compression molded test piece whose specific resistance was examined. The compression molded specimen was examined for magnetic properties.

  (8) A mechanical bending test was carried out using the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (5). For the bending test, a compression molded body having a sample shape of 15 mm × 10 mm × 2 mm was used, and the bending strength was evaluated by a three-point bending test with a distance between supporting points of 12 mm.

Regarding the magnetic properties of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (5), the residual magnetic flux density can be improved by 20-30% compared to the resin-containing bond magnet (Comparative Example 1). , and the demagnetization curve was measured at 20 ° C., the value of residual magnetic flux density and coercivity and SiO ₂ before impregnated with the molded body after SiO ₂ infiltration and heating were almost the same. Further, the thermal demagnetization factor after 1 hour of holding at 200 ° C. in the atmosphere is 3.0% for the SiO ₂ impregnated bonded magnet, which is smaller than the thermal demagnetization factor (5%) without SiO ₂ impregnation. Furthermore, the irreversible heat demagnetization rate is also maintained in the atmosphere at 200 ° C. for 1 hour,
It is 1% or less after the SiO ₂ impregnation heat treatment and is smaller than a value close to 3% in the case of no SiO ₂ impregnation. This is because SiO ₂ suppresses deterioration due to oxidation of magnetic powder.

The bending strength of the compression molded test piece having a length of 15 mm, a width of 10 mm and a thickness of 2 mm produced in (7) is ₂ MPa or less before the SiO ₂ impregnation, but after the SiO ₂ impregnation heat treatment, it is 70 MPa or more. ), 3) When the SiO ₂ precursor solution was used, it was possible to produce a magnet molded body having a bending strength of 100 MPa or more.

  The specific resistance of the magnet was about 10 times that of the sintered rare earth magnet, but about 1/10 that of the compressed rare earth bonded magnet. became. Although eddy current loss may increase slightly, it does not interfere with use.

From the results of this example, the rare earth bonded magnet impregnated in the rare earth magnet molded body produced by the cold forming method without using the low-viscosity SiO ₂ precursor of the present invention is compared with a normal resin-containing rare earth bonded magnet. As a result, it was found that the magnetic properties are 20-30%, the bending strength is 2-3 times, the irreversible thermal demagnetization rate is reduced to less than half, and the magnet can be highly reliable.

[Example 3 of permanent magnet]
In this example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used for the rare earth magnet magnetic powder. The following three solutions were used for the SiO ₂ precursor as a binder.

1) CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ was mixed with 25 ml, water 5.9 ml, dehydrated methyl alcohol 75 ml, and dibutyltin dilaurate 0.05 ml. Left at temperature.

_{2) CH 3 O- (Si (} CH 3 O) 2 -O) m -CH 3 (m is 3-5, average 4) 25 ml, water 4.8 ml, dehydrated methanol 75 ml, dibutyltin dilaurate 0 0.05 ml was mixed and left at a temperature of 25 ° C. for 2 days and nights.

3) 25 ml of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 6 to 8, average is 7), water 4.6 ml, dehydrated methyl alcohol 75 ml, dibutyltin dilaurate 0 0.05 ml was mixed and left at a temperature of 25 ° C. for 2 days and nights.

The viscosities of the SiO ₂ precursor solutions 1) to 3) were measured at a temperature of 30 ° C. using an Ostwald viscometer.

(1) The above Nd ₂ Fe ₁₄ B magnetic powder is filled in a mold, and a test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm is used for measuring magnetic properties at a pressure of 16 t / cm ² . A compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm was prepared.

(2) The compression molded test piece prepared in (1) is placed in the bat so that the pressing direction is horizontal, and the SiO ₂ precursor solution of 1) to 3) as the binder is placed in the bat. Liquid level is 1 in the vertical direction
Injection was performed so as to be mm / min. The SiO ₂ precursor solution was poured into the vat until it was finally 5 mm above the upper surface of the compression molded specimen.

(3) The compression-molded test piece used in (2) was placed, and the bat filled with the SiO ₂ precursor solution was set in a vacuum vessel and gradually exhausted to about 80 Pa. The sample was left until the generation of bubbles from the surface of the compression molded test piece was reduced.

(4) The compression molded test piece was placed, the internal pressure of the vacuum vessel in which the bat filled with the SiO ₂ precursor solution was set was gradually returned to atmospheric pressure, and the compression molded test piece was taken out from the SiO ₂ precursor solution. .

(5) The compression molding test piece impregnated with the SiO ₂ precursor solution prepared in (4) is set in a vacuum drying furnace, and vacuum is applied to the compression molding test piece under the conditions of 1 to 3 Pa and 150 ° C. Heat treatment was applied.

  (6) The specific resistance was measured by the four-probe method for the compression molded test piece of 10 mm length, 10 mm width, and 5 mm thickness produced in (5).

  (7) Further, a pulse magnetic field of 30 kOe or more was applied to the compression molded test piece whose specific resistance was examined. The compression molded specimen was examined for magnetic properties.

  (8) A mechanical bending test was carried out using the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (5). For the bending test, a compression molded body having a sample shape of 15 mm × 10 mm × 2 mm was used, and the bending strength was evaluated by a three-point bending test with a distance between supporting points of 12 mm.

Regarding the magnetic properties of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (5), the residual magnetic flux density can be improved by 20-30% compared to the resin-containing bond magnet (Comparative Example 1). in and, 20 ° C. demagnetization curve measured at (invention confirmation necessity to have) the value of residual magnetic flux density and coercivity and SiO ₂ before impregnated and molded body after SiO ₂ infiltration and heating were almost the same. In addition, the thermal demagnetization rate after 1 hour holding in the atmosphere at 200 ° C. (need to be confirmed by the inventor) is 3.0% for the SiO ₂ impregnated bonded magnet, which is higher than the thermal demagnetization factor without SiO ₂ impregnation (5%). small. Further, the irreversible thermal demagnetization rate is 1% or less after the SiO ₂ impregnation heat treatment after being held in the atmosphere at 200 ° C. for 1 hour, and is smaller than the value close to 3% in the case of no SiO ₂ impregnation. This is because SiO ₂ suppresses deterioration due to oxidation of magnetic powder.

The bending strength of the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (7) is ₂ MPa or less before SiO ₂ impregnation, but has a bending strength of 100 MPa or more after SiO ₂ impregnation heat treatment. It was possible to make a body.

  The specific resistance of the magnet was about 10 times that of the sintered rare earth magnet, but about 1/10 that of the compressed rare earth bonded magnet. became. However, this decrease in resistance is not a big problem. For example, when used as a rotating electrical machine, the eddy current loss slightly increases, but does not become a problem that hinders use.

From the results of this example, the rare earth bonded magnet impregnated in the rare earth magnet molded body produced by the cold forming method without using the low-viscosity SiO ₂ precursor of the present invention is compared with a normal resin-containing rare earth bonded magnet. As a result, it was found that the magnetic properties are 20-30%, the bending strength is 2-3 times, the irreversible thermal demagnetization rate is reduced to less than half, and the magnet can be highly reliable.

[Embodiment 4 of permanent magnet]
In this example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used for the rare earth magnet magnetic powder. The following three solutions were used for the SiO ₂ precursor as a binder.

1) CH ₃ O— (Si (CH ₃ O) ₂ —O) —CH ₃ was mixed with 25 ml, water 5.9 ml, dehydrated methyl alcohol 75 ml, and dibutyltin dilaurate 0.05 ml. Left alone.

2) 25 ml of C ₂ H ₅ O— (Si (C ₂ H ₅ O) ₂ —O) —CH ₃ , 4.3 ml of water, 75 ml of dehydrated ethyl alcohol, and 0.05 ml of dibutyltin dilaurate were mixed for 3 days and nights. It was left at a temperature of 25 ° C.

_{3) n-C 3 H 7} O- (Si (C 2 H 5 O) 2 -O) -n-C 3 a H ₇ 25 ml, water 3.4 ml, dried iso- propyl alcohol 75 ml, dibutyltin dilaurate 0 0.05 ml was mixed and left at a temperature of 25 ° C. for 6 days and nights.

The viscosities of the SiO ₂ precursor solutions 1) to 3) were measured at a temperature of 30 ° C. using an Ostwald viscometer.

(1) The above Nd ₂ Fe ₁₄ B magnetic powder is filled in a mold, and a test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm is used for measuring magnetic properties at a pressure of 16 t / cm ² . A compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm was prepared.

(2) The compression molded test piece prepared in (1) is placed in the bat so that the pressing direction is horizontal, and the SiO ₂ precursor solution of 1) to 3) as the binder is placed in the bat. Liquid level is 1 in the vertical direction
Injection was performed so as to be mm / min. The SiO ₂ precursor solution was poured into the vat until it was finally 5 mm above the upper surface of the compression molded specimen.

(3) The compression-molded test piece used in (2) was placed, and the bat filled with the SiO ₂ precursor solution was set in a vacuum vessel and gradually exhausted to about 80 Pa. The sample was left until the generation of bubbles from the surface of the compression molded test piece was reduced.

(4) The compression molded test piece was placed, the internal pressure of the vacuum vessel in which the bat filled with the SiO ₂ precursor solution was set was gradually returned to atmospheric pressure, and the compression molded test piece was taken out from the SiO ₂ precursor solution. .

(5) The compression molding test piece impregnated with the SiO ₂ precursor solution prepared in (4) is set in a vacuum drying furnace, and vacuum is applied to the compression molding test piece under the conditions of 1 to 3 Pa and 150 ° C. Heat treatment was applied.

  (6) The specific resistance was measured by the four-probe method for the compression molded test piece of 10 mm length, 10 mm width, and 5 mm thickness produced in (5).

  (7) Further, a pulse magnetic field of 30 kOe or more was applied to the compression molded test piece whose specific resistance was examined. The compression molded specimen was examined for magnetic properties.

  (8) A mechanical bending test was carried out using the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (5). For the bending test, a compression molded body having a sample shape of 15 mm × 10 mm × 2 mm was used, and the bending strength was evaluated by a three-point bending test with a distance between supporting points of 12 mm.

Regarding the magnetic properties of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (5), the residual magnetic flux density can be improved by 20-30% compared to the resin-containing bond magnet (Comparative Example 1). , and the demagnetization curve was measured at 20 ° C., the value of residual magnetic flux density and coercivity and SiO ₂ before impregnated with the molded body after SiO ₂ infiltration and heating were almost the same. In addition, the thermal demagnetization factor after 1 hour of holding at 200 ° C. in the atmosphere is 3.0% for the SiO ₂ impregnated bonded magnet, which is smaller than the thermal demagnetization factor (5%) without SiO ₂ impregnation. Further, the irreversible thermal demagnetization rate is 1% or less after the SiO ₂ impregnation heat treatment after being held in the atmosphere at 200 ° C. for 1 hour, and is smaller than the value close to 3% in the case of no SiO ₂ impregnation. This is because SiO ₂ suppresses deterioration due to oxidation of magnetic powder.

The bending strength of the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (7) is ₂ MPa or less before SiO ₂ impregnation, but has a bending strength of 80 MPa or more after SiO ₂ impregnation heat treatment. It was possible to make a body.

  The specific resistance of the magnet was about 10 times that of the sintered rare earth magnet, but about 1/10 that of the compressed rare earth bonded magnet. became. Although the generation of eddy current loss is slightly increased, such a decrease in resistance value is not a problem.

From the results of this example, the rare earth bonded magnet impregnated in the rare earth magnet molded body produced by the cold forming method without using the low-viscosity SiO ₂ precursor of the present invention is compared with a normal resin-containing rare earth bonded magnet. Thus, it has been found that the magnetic properties are 20-30%, the bending strength is about twice, the irreversible thermal demagnetization rate can be reduced to less than half, and the magnet can be highly reliable.

[Example 5 of permanent magnet]
In this example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used for the rare earth magnet magnetic powder. The following three solutions were used for the SiO ₂ precursor as a binder.

_{1) CH 3 O- (Si (} CH 3 O) 2 -O) m -CH 3 (m is 3-5, average 4) 25 ml, water 9.6 ml, dehydrated methanol 75 ml, dibutyltin dilaurate 0 0.05 ml was mixed and left at a temperature of 25 ° C. overnight.

_{2) CH 3 O- (Si (} CH 3 O) 2 -O) m -CH 3 (m is 3-5, average 4) 25 ml, water 9.6 ml, dehydrated methanol 75 ml, dibutyltin dilaurate 0 0.05 ml was mixed and left at a temperature of 25 ° C. for 2 days and nights.

_{3) CH 3 O- (Si (} CH 3 O) 2 -O) m -CH 3 (m is 3-5, average 4) 100 ml, water 9.6 ml, dehydrated methanol 75 ml, dibutyltin dilaurate 0 0.05 ml was mixed and left at a temperature of 25 ° C. for 4 days.

The viscosities of the SiO ₂ precursor solutions 1) to 3) were measured at a temperature of 30 ° C. using an Ostwald viscometer.

(1) The above Nd ₂ Fe ₁₄ B magnetic powder is filled in a mold, and a test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm is used for measuring magnetic properties at a pressure of 16 t / cm ² . A compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm was prepared.

(2) The compression molded test piece prepared in (1) is placed in the bat so that the pressing direction is horizontal, and the SiO ₂ precursor solution of 1) to 3) as the binder is placed in the bat. Injection was performed so that the liquid level was 1 mm / min in the vertical direction. The SiO ₂ precursor solution was poured into the vat until it was finally 5 mm above the upper surface of the compression molded specimen.

(3) The compression-molded test piece used in (2) was placed, and the bat filled with the SiO ₂ precursor solution was set in a vacuum vessel and gradually exhausted to about 80 Pa. The sample was left until the generation of bubbles from the surface of the compression molded test piece was reduced.

(4) The compression molded test piece was placed, the internal pressure of the vacuum vessel in which the bat filled with the SiO ₂ precursor solution was set was gradually returned to atmospheric pressure, and the compression molded test piece was taken out from the SiO ₂ precursor solution. .

(5) The compression molding test piece impregnated with the SiO ₂ precursor solution prepared in (4) is set in a vacuum drying furnace, and vacuum is applied to the compression molding test piece under the conditions of 1 to 3 Pa and 150 ° C. Heat treatment was applied.

  (6) The specific resistance was measured by the four-probe method for the compression molded test piece of 10 mm length, 10 mm width, and 5 mm thickness produced in (5).

  (7) Further, a pulse magnetic field of 30 kOe or more was applied to the compression molded test piece whose specific resistance was examined. The compression molded specimen was examined for magnetic properties.

  (8) A mechanical bending test was carried out using the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (5). For the bending test, a compression molded body having a sample shape of 15 mm × 10 mm × 2 mm was used, and the bending strength was evaluated by a three-point bending test with a distance between supporting points of 12 mm.

Regarding the magnetic properties of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (5) above, the residual magnetic flux density is improved by 20-30% compared to the resin-containing bond magnet (Comparative Example 1). are possible, the demagnetization curve was measured at 20 ° C., the value of residual magnetic flux density and coercivity and SiO ₂ before impregnated with the molded body after SiO ₂ infiltration and heating were almost the same. Further, the thermal demagnetization factor after 1 hour of holding at 200 ° C. in the atmosphere is 3.0% for the SiO ₂ impregnated bonded magnet, which is smaller than the thermal demagnetization factor (5%) without SiO ₂ impregnation. Further, the irreversible thermal demagnetization rate is 1% or less after the SiO ₂ impregnation heat treatment after being held in the atmosphere at 200 ° C. for 1 hour, and is smaller than the value close to 3% in the case of no SiO ₂ impregnation. This is because SiO ₂ suppresses deterioration due to oxidation of magnetic powder.

The bending strength of the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (7) above is ₂ MPa or less before SiO ₂ impregnation, but has a bending strength of 130 MPa or more after SiO ₂ impregnation heat treatment. It was possible to produce a molded body.

  The specific resistance of the magnet was about 10 times that of the sintered rare earth magnet, but about 1/10 that of the compressed rare earth bonded magnet. became. Although the generation of eddy current loss is slightly increased, such a decrease in resistance value is not a problem.

From the results of this example, the rare earth bonded magnet impregnated in the rare earth magnet molded body produced by the cold forming method without using the low-viscosity SiO ₂ precursor of the present invention is compared with a normal resin-containing rare earth bonded magnet. As a result, it was found that the magnetic properties are 20-30%, the bending strength is 3-4 times, the irreversible thermal demagnetization rate can be reduced to less than half and the magnet can be highly reliable.

[Example 6 of permanent magnet]
In this example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used for the rare earth magnet magnetic powder. A treatment liquid for forming a rare earth fluoride or alkaline earth metal fluoride coating film was prepared as follows.

  (1) A salt having high solubility in water, for example, in the case of La, acetic acid La or nitric acid La 4 g was introduced into 100 ml of water, and completely dissolved using a shaker or an ultrasonic stirrer.

(2) The equivalent of the chemical reaction in which LaF ₃ produces hydrofluoric acid diluted to 10% was gradually added.

(3) The solution in which LaF ₃ of gelled precipitate was formed was stirred for 1 hour or more using an ultrasonic stirrer.

  (4) After centrifuging at 4000 to 6000 rpm, the supernatant was removed and approximately the same amount of methanol was added.

(5) A methanol solution containing gelled LaF ₃ was stirred to make a complete suspension, and then stirred for 1 hour or more using an ultrasonic stirrer.

  (6) The operations of (4) and (5) were repeated 3 to 10 times until no anion such as acetate ion or nitrate ion was detected.

(7) When finally LaF _3, was the LaF ₃ almost transparent sol-like. As the treatment liquid, a methanol solution containing 1 g / 5 ml of LaF ₃ was used.

  The other rare earth fluoride or alkaline earth metal fluoride coating film forming treatment liquids are summarized in Table 3.

The process of forming the rare earth fluoride or alkaline earth metal fluoride coat film on the magnetic powder of Nd ₂ Fe ₁₄ B was carried out by the following method.

In the case of NdF ₃ coat film formation process: NdF ₃ concentration 1 g / 10 ml translucent sol solution (1) Add 15 ml of NdF ₃ coat film forming treatment liquid to 100 g of magnetic powder obtained by pulverizing NdFeB thin ribbon, The mixing was performed until it was confirmed that the entire magnetic powder for rare earth magnet was wet.

(2) The methanol powder of the rare earth magnet subjected to the NdF ₃ coat film forming treatment of (1) was subjected to methanol removal under a reduced pressure of 2 to 5 torr.

(3) The rare earth magnet magnetic powder from which the solvent in (2) was removed was transferred to a quartz boat and heat-treated at 200 ° C. for 30 minutes and 400 ° C. for 30 minutes under a reduced pressure of 1 × 10 ⁻⁵ torr. .

(4) The magnetic powder heat-treated in (3) is transferred to a Macor lidded lid (manufactured by Riken Denshi Co., Ltd.) and then heat-treated at 700 ° C. for 30 minutes under a reduced pressure of 1 × 10 ⁻⁵ torr. It was.

The SiO ₂ precursor, which is a binder, contains 25 ml of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, the average is 4), 4.8 ml of water, dehydrated A solution obtained by mixing 75 ml of methyl alcohol and 0.05 ml of dibutyltin dilaurate and leaving it at a temperature of 25 ° C. for 2 days and nights was used.

(1) Nd ₂ Fe ₁₄ B magnetic powder coated with the rare earth fluoride or alkaline earth metal fluoride coating film is filled in a mold, and is 10 mm in length and 16 mm in width for measuring magnetic properties at a pressure of 16 t / cm ^2. A test piece having a thickness of 10 mm and a thickness of 5 mm was prepared, and a compression test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm was prepared for strength measurement.

(2) The SiO ₂ precursor solution, which is a binder, placed in a bat so that the pressing direction is in the horizontal direction and left at a temperature of 25 ° C. for two days and nights. Was injected into the vat so that the liquid level was 1 mm / min in the vertical direction. The SiO ₂ precursor solution was poured into the vat until it was finally 5 mm above the upper surface of the compression molded specimen.

(3) The compression molding test piece used in the above (2) was arranged, and a bat filled with the SiO ₂ precursor solution was set in a vacuum vessel and gradually exhausted to about 80 Pa. The sample was left until the generation of bubbles from the surface of the compression molded test piece was reduced.

(4) The compression molded test piece was placed, the internal pressure of the vacuum vessel in which the bat filled with the SiO ₂ precursor solution was set was gradually returned to atmospheric pressure, and the compression molded test piece was taken out from the SiO ₂ precursor solution. .

(5) The compression molding test piece impregnated with the SiO ₂ precursor solution prepared in the above (4) is set in a vacuum drying furnace, and the compression molding test piece is subjected to a pressure of 1 to 3 Pa at 150 ° C. Vacuum heat treatment was applied.

  (6) The specific resistance was measured by the four-probe method for the compression molded test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm produced in the above (5).

  (7) Further, a pulse magnetic field of 30 kOe or more was applied to the compression molded test piece whose specific resistance was examined. The compression molded specimen was examined for magnetic properties.

  (8) A mechanical bending test was performed using the compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm prepared in (5) above. For the bending test, a compression molded body having a sample shape of 15 mm × 10 mm × 2 mm was used, and the bending strength was evaluated by a three-point bending test with a distance between supporting points of 12 mm.

Regarding the magnetic properties of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (5) above, the residual magnetic flux density is improved by 20-30% compared to the resin-containing bond magnet (Comparative Example 1). are possible, the demagnetization curve was measured at 20 ° C., the value of residual magnetic flux density and coercivity and SiO ₂ before impregnated with the molded body after SiO ₂ infiltration and heating were almost the same. Further, the thermal demagnetization factor after 1 hour of holding at 200 ° C. in the atmosphere is 3.0% for the SiO ₂ impregnated bonded magnet, which is smaller than the thermal demagnetization factor (5%) without SiO ₂ impregnation. Further, the irreversible thermal demagnetization rate is 1% or less after the SiO ₂ impregnation heat treatment after being held in the atmosphere at 200 ° C. for 1 hour, and is smaller than the value close to 3% in the case of no SiO ₂ impregnation. This is because SiO ₂ suppresses deterioration due to oxidation of magnetic powder.

The magnet using the rare earth magnetic powder formed with the rare earth fluoride or alkaline earth metal fluoride coating film of this embodiment not only functions as an insulating film described later, but also uses TbF ₃ and DyF ₃ , and although the effect is small, PrF It was found that when ₃ was used for coating film formation, it could contribute to the improvement of the coercive force of the magnet.

The bending strength of the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (7) above is ₂ MPa or less before SiO ₂ impregnation, but has a bending strength of 50 MPa or more after SiO ₂ impregnation heat treatment. It was possible to produce a molded body.

  Further, the specific resistance of the magnet is about 100 times or more that of the sintered type rare earth magnet, and is equivalent to that of the compressed type rare earth bonded magnet. . Therefore, the eddy current loss is small, and it has good characteristics.

From the results of this example, the rare earth bonded magnet impregnated in the rare earth magnet molded body produced by the cold forming method without using the low-viscosity SiO ₂ precursor of the present invention is compared with a normal resin-containing rare earth bonded magnet. In addition, the magnetic properties are about 20%, the bending strength is equivalent to 3 times, the irreversible thermal demagnetization rate can be reduced to less than half, and the magnet can be made more reliable, and TbF ₃ and DyF ₃ are coated. It was found that the magnetic characteristics can be greatly improved when used for forming.

[Example 7 of permanent magnet]
In this example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used. The process of forming the rare earth fluoride or alkaline earth metal fluoride coat film on the magnetic powder of Nd ₂ Fe ₁₄ B was carried out by the following method.

In the case of the PrF ₃ coat film forming process: A PrF ₃ concentration of 0.1 g / 10 ml translucent sol solution was used.

(1) 1 to 30 ml of PrF ₃ coat film forming treatment liquid was added to 100 g of magnetic powder obtained by pulverizing NdFeB-based ribbon, and mixed until it was confirmed that the entire magnetic powder for rare earth magnets was wet.

(2) Methanol was removed from the solvent of the rare earth magnet magnetic powder subjected to the PrF ₃ coat film forming treatment of (1) above under a reduced pressure of 2 to 5 torr.

(3) The rare earth magnet magnetic powder from which the solvent of (2) has been removed is transferred to a quartz boat and heat-treated at 200 ° C. for 30 minutes and 400 ° C. for 30 minutes under a reduced pressure of 1 × 10 ⁻⁵ torr. It was.

(4) After the magnetic powder heat-treated in (3) above is transferred to a lid made by Macor (manufactured by Riken Denshi), heat treatment is performed at 700 ° C. for 30 minutes under a reduced pressure of 1 × 10 ⁻⁵ torr. went.

The SiO ₂ precursor, which is a binder, contains 25 ml of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, the average is 4), 4.8 ml of water, dehydrated A solution obtained by mixing 75 ml of methyl alcohol and 0.05 ml of dibutyltin dilaurate and leaving it at a temperature of 25 ° C. for 2 days and nights was used.

(1) Nd ₂ Fe ₁₄ B magnetic powder coated with the above PrF ₃ coating film is filled in a mold, and a test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm is used for measuring magnetic properties at a pressure of 16 t / cm ^2. Also, a compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm was prepared for strength measurement.

(2) The SiO ₂ precursor solution, which is a binder, placed in a bat so that the pressing direction is in the horizontal direction and left at a temperature of 25 ° C. for two days and nights. Was injected into the vat so that the liquid level was 1 mm / min in the vertical direction. The SiO ₂ precursor solution was poured into the vat until it was finally 5 mm above the upper surface of the compression molded specimen.

(3) The compression molding test piece used in the above (2) was arranged, and a bat filled with the SiO ₂ precursor solution was set in a vacuum vessel and gradually exhausted to about 80 Pa. The sample was left until the generation of bubbles from the surface of the compression molded test piece was reduced.

(4) The compression molded test piece was placed, the internal pressure of the vacuum vessel in which the bat filled with the SiO ₂ precursor solution was set was gradually returned to atmospheric pressure, and the compression molded test piece was taken out from the SiO ₂ precursor solution. .

(5) The compression molding test piece impregnated with the SiO ₂ precursor solution prepared in the above (4) is set in a vacuum drying furnace, and the compression molding test piece is subjected to a pressure of 1 to 3 Pa at 150 ° C. Vacuum heat treatment was applied.

  (6) The specific resistance was measured by the four-probe method for the compression molded test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm produced in the above (5).

  (7) Further, a pulse magnetic field of 30 kOe or more was applied to the compression molded test piece whose specific resistance was examined. The compression molded specimen was examined for magnetic properties.

  (8) A mechanical bending test was performed using the compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm prepared in (5) above. For the bending test, a compression molded body having a sample shape of 15 mm × 10 mm × 2 mm was used, and the bending strength was evaluated by a three-point bending test with a distance between supporting points of 12 mm.

Regarding the magnetic properties of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (5) above, the residual magnetic flux density is improved by 20-30% compared to the resin-containing bond magnet (Comparative Example 1). are possible, the demagnetization curve was measured at 20 ° C., the value of residual magnetic flux density and coercivity and SiO ₂ before impregnated with the molded body after SiO ₂ infiltration and heating were almost the same. Further, the thermal demagnetization factor after 1 hour of holding at 200 ° C. in the atmosphere is 3.0% for the SiO ₂ impregnated bonded magnet, which is smaller than the thermal demagnetization factor (5%) without SiO ₂ impregnation. Further, the irreversible thermal demagnetization rate is 1% or less after the SiO ₂ impregnation heat treatment after being held in the atmosphere at 200 ° C. for 1 hour, and is smaller than the value close to 3% in the case of no SiO ₂ impregnation. This is because SiO ₂ suppresses deterioration due to oxidation of magnetic powder.

It was found that the magnet using the rare earth magnetic powder formed with the PrF ₃ coat film of this example not only functions as an insulating film to be described later, but can contribute to the improvement of the coercive force of the magnet although the effect is small.

The bending strength of the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (7) above is ₂ MPa or less before SiO ₂ impregnation, but has a bending strength of 100 MPa or more after SiO ₂ impregnation heat treatment. It was possible to produce a molded body.

  Further, the specific resistance of the magnet is about 100 times or more that of the sintered type rare earth magnet, and is equivalent to that of the compressed type rare earth bonded magnet. . Therefore, the occurrence of eddy current loss is small and it has good characteristics.

From the results of this example, the rare earth bonded magnet impregnated in the rare earth magnet molded body produced by the cold forming method without using the low-viscosity SiO ₂ precursor of the present invention is compared with a normal resin-containing rare earth bonded magnet. In addition, the magnetic properties are about 20%, the bending strength is 2 to 3 times, the irreversible thermal demagnetization rate can be reduced to less than half and the magnet can be highly reliable, and PrF ₃ is used for forming the coating film. It was found that magnetic characteristics can be improved at times. It was found that a magnet using rare earth magnetic powder formed with a coating film of PrF ₃ is a well-balanced magnet with improved overall magnetic properties, bending strength and reliability.

[Example 8 of permanent magnet]
In this example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used. The process of forming the rare earth fluoride or alkaline earth metal fluoride coat film on the magnetic powder of Nd ₂ Fe ₁₄ B was carried out by the following method.

In the case of the DyF ₃ coat film formation process: A DyF ₃ concentration of 2 to 0.01 g / 10 ml of a translucent sol solution was used.

(1) 10 ml of DyF ₃ coat film forming solution was added to 100 g of magnetic powder obtained by pulverizing NdFeB-based ribbon, and mixed until it was confirmed that the entire magnetic powder for rare earth magnet was wetted.

(2) The methanol of the solvent was removed from the rare earth magnet magnetic powder that had been subjected to the DyF ₃ coat film forming process of (1) above under a reduced pressure of 2 to 5 torr.

(3) The rare earth magnet magnetic powder from which the solvent of (2) has been removed is transferred to a quartz boat and heat-treated at 200 ° C. for 30 minutes and 400 ° C. for 30 minutes under a reduced pressure of 1 × 10 ⁻⁵ torr. It was.

(4) After the magnetic powder heat-treated in (3) above is transferred to a lid made by Macor (manufactured by Riken Denshi), heat treatment is performed at 700 ° C. for 30 minutes under a reduced pressure of 1 × 10 ⁻⁵ torr. went.

The SiO ₂ precursor, which is a binder, contains 25 ml of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, the average is 4), 4.8 ml of water, dehydrated A solution obtained by mixing 75 ml of methyl alcohol and 0.05 ml of dibutyltin dilaurate and leaving it at a temperature of 25 ° C. for 2 days and nights was used.

(1) Nd ₂ Fe ₁₄ B magnetic powder coated with the above DyF ₃ coating film is filled in a mold, and a test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm is used for measuring magnetic properties at a pressure of 16 t / cm ^2. Also, a compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm was prepared for strength measurement.

(2) The SiO ₂ precursor solution, which is a binder, placed in a bat so that the pressing direction is in the horizontal direction and left at a temperature of 25 ° C. for two days and nights. Was injected into the vat so that the liquid level was 1 mm / min in the vertical direction. The SiO ₂ precursor solution was poured into the vat until it was finally 5 mm above the upper surface of the compression molded specimen.

(3) The compression molding test piece used in the above (2) was arranged, and a bat filled with the SiO ₂ precursor solution was set in a vacuum vessel and gradually exhausted to about 80 Pa. The sample was left until the generation of bubbles from the surface of the compression molded test piece was reduced.

(4) The compression molded test piece was placed, the internal pressure of the vacuum vessel in which the bat filled with the SiO ₂ precursor solution was set was gradually returned to atmospheric pressure, and the compression molded test piece was taken out from the SiO ₂ precursor solution. .

(5) The compression molding test piece impregnated with the SiO ₂ precursor solution prepared in the above (4) is set in a vacuum drying furnace, and the compression molding test piece is subjected to a pressure of 1 to 3 Pa at 150 ° C. Vacuum heat treatment was applied.

  (6) The specific resistance was measured by the four-probe method for the compression molded test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm produced in the above (5).

  (7) Further, a pulse magnetic field of 30 kOe or more was applied to the compression molded test piece whose specific resistance was examined. The compression molded specimen was examined for magnetic properties.

  (8) A mechanical bending test was performed using the compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm prepared in (5) above. For the bending test, a compression molded body having a sample shape of 15 mm × 10 mm × 2 mm was used, and the bending strength was evaluated by a three-point bending test with a distance between supporting points of 12 mm.

Regarding the magnetic properties of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (5) above, the residual magnetic flux density is improved by 20-30% compared to the resin-containing bond magnet (Comparative Example 1). are possible, the demagnetization curve was measured at 20 ° C., the value of residual magnetic flux density and coercivity and SiO ₂ before impregnated with the molded body after SiO ₂ infiltration and heating were almost the same. Further, the thermal demagnetization factor after 1 hour of holding at 200 ° C. in the atmosphere is 3.0% for the SiO ₂ impregnated bonded magnet, which is smaller than the thermal demagnetization factor (5%) without SiO ₂ impregnation. Further, the irreversible thermal demagnetization rate is 1% or less after the SiO ₂ impregnation heat treatment after being held in the atmosphere at 200 ° C. for 1 hour, and is smaller than the value close to 3% in the case of no SiO ₂ impregnation. This is because SiO ₂ suppresses deterioration due to oxidation of magnetic powder.

It was found that the magnet using the rare earth magnetic powder formed with the DyF ₃ coating film of this example not only functions as an insulating film described later, but can contribute to the improvement of the coercive force of the magnet.

The bending strength of the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (7) above is ₂ MPa or less before SiO ₂ impregnation, but has a bending strength of 40 MPa or more after SiO ₂ impregnation heat treatment. It was possible to produce a molded body.

  Further, the specific resistance of the magnet is about 100 times or more that of the sintered type rare earth magnet, and the same value as that of the compression type rare earth bonded magnet. Therefore, the eddy current loss is small, and it has good characteristics.

From the results of this example, the rare earth bonded magnet impregnated in the rare earth magnet molded body produced by the cold forming method without using the low-viscosity SiO ₂ precursor of the present invention is compared with a normal resin-containing rare earth bonded magnet. In addition, the magnetic properties are about 20%, the bending strength is equivalent to 3 times, the irreversible thermal demagnetization rate can be reduced to less than half, and the magnet can be made more reliable, and TbF ₃ and DyF ₃ are coated. It was found that the magnetic properties can be greatly improved when used for formation.

[Example 9 of permanent magnet]
In this example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used for the rare earth magnet magnetic powder. The treatment liquid for forming the phosphate chemical conversion film was prepared as follows.

20 g of phosphoric acid, 4 g of boric acid and 4 g of MgO, ZnO, CdO, CaO or BaO are dissolved in 1 l of water, and EF-104 (manufactured by Tochem Products), EF-122 (Tochem Products) are used as surfactants. EF-132 (manufactured by Tochem Products) was added to 0.1 wt%. As rust preventives, benzotriazole (BT), imidazole (IZ), benzimidazole (BI), thiourea (TU), 2-mercaptobenzimidazole (MI), octylamine (OA), triethanolamine (TA), o-Toluidine (TL), indole (ID), and 2-methylpyrrole (MP) were added at 0.04 mol / l.

The process of forming the phosphate chemical conversion film on the magnetic powder of Nd ₂ Fe ₁₄ B was carried out by the following method. Table 4 shows the composition of the phosphating solution used.

  (1) 5 ml of a phosphating solution was added to 100 g of magnetic powder obtained by pulverizing a NdFeB-based ribbon, and mixed until it was confirmed that the entire magnetic powder for rare earth magnets was wetted.

  (2) The magnetic powder for rare earth magnet subjected to the phosphatization film forming treatment of (1) was heat-treated at 180 ° C. for 30 minutes under a reduced pressure of 2 to 5 torr.

The SiO ₂ precursor, which is a binder, contains 25 ml of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, the average is 4), 4.8 ml of water, dehydrated A solution obtained by mixing 75 ml of methyl alcohol and 0.05 ml of dibutyltin dilaurate and leaving it at a temperature of 25 ° C. for 2 days and nights was used.

(1) Filling the mold with Nd ₂ Fe ₁₄ B magnetic powder that has been subjected to the above-mentioned phosphatization film formation treatment, and measuring the magnetic properties at a pressure of 16 t / cm ² , the length is 10 mm, the width is 10 mm, and the thickness is 5 mm. In addition, a compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm was prepared for strength measurement.

(2) The SiO ₂ precursor solution, which is a binder, placed in a bat so that the pressing direction is in the horizontal direction and left at a temperature of 25 ° C. for two days and nights. Was injected into the vat so that the liquid level was 1 mm / min in the vertical direction. The SiO ₂ precursor solution was poured into the vat until it was finally 5 mm above the upper surface of the compression molded specimen.

(3) The compression molding test piece used in the above (2) was arranged, and a bat filled with the SiO ₂ precursor solution was set in a vacuum vessel and gradually exhausted to about 80 Pa. The sample was left until the generation of bubbles from the surface of the compression molded test piece was reduced.

(4) The compression molded test piece was placed, the internal pressure of the vacuum vessel in which the bat filled with the SiO ₂ precursor solution was set was gradually returned to atmospheric pressure, and the compression molded test piece was taken out from the SiO ₂ precursor solution. .

(5) The compression molding test piece impregnated with the SiO ₂ precursor solution prepared in the above (4) is set in a vacuum drying furnace, and the compression molding test piece is subjected to a pressure of 1 to 3 Pa at 150 ° C. Vacuum heat treatment was applied.

  (6) The specific resistance was measured by the four-probe method for the compression molded test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm produced in the above (5).

  (7) Further, a pulse magnetic field of 30 kOe or more was applied to the compression molded test piece whose specific resistance was examined. The compression molded specimen was examined for magnetic properties.

  (8) A mechanical bending test was performed using the compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm prepared in (5) above. For the bending test, a compression molded body having a sample shape of 15 mm × 10 mm × 2 mm was used, and the bending strength was evaluated by a three-point bending test with a distance between supporting points of 12 mm.

Regarding the magnetic properties of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (5), the residual magnetic flux density can be improved by 20-30% compared to the resin-containing bond magnet (Comparative Example 1). , and the demagnetization curve was measured at 20 ° C., the value of residual magnetic flux density and coercivity and SiO ₂ before impregnated with the molded body after SiO ₂ infiltration and heating were almost the same. Further, the thermal demagnetization factor after 1 hour of holding at 200 ° C. in the atmosphere is 3.0% for the SiO ₂ impregnated bonded magnet, which is smaller than the thermal demagnetization factor (5%) without SiO ₂ impregnation. Furthermore, the irreversible heat demagnetization rate is also maintained in the atmosphere at 200 ° C. for 1 hour,
It is 1% or less after the SiO ₂ impregnation heat treatment and is smaller than a value close to 3% in the case of no SiO ₂ impregnation. This is because SiO ₂ suppresses deterioration due to oxidation of magnetic powder.

The bending strength of the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (7) above is ₂ MPa or less before SiO ₂ impregnation, but has a bending strength of 100 MPa or more after SiO ₂ impregnation heat treatment. It was possible to produce a molded body.

  Further, the specific resistance of the magnet is about 100 times or more that of the sintered type rare earth magnet, and is equivalent to that of the compressed type rare earth bonded magnet. . Therefore, the eddy current loss is small, and it has good characteristics.

From the results of this example, the rare earth bonded magnet impregnated in the rare earth magnet molded body produced by the cold forming method without using the low-viscosity SiO ₂ precursor of the present invention is compared with a normal resin-containing rare earth bonded magnet. Thus, it has been found that the magnetic properties are 20-30%, the bending strength is about 3 times, the irreversible thermal demagnetization rate is reduced to less than half, and the magnet can be highly reliable.

[Example 10 of permanent magnet]
In this example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used for the rare earth magnet magnetic powder. The treatment liquid for forming the phosphate chemical conversion film was prepared as follows. 20 g of phosphoric acid, 4 g of boric acid and 4 g of MgO as a metal oxide were dissolved in 1 liter of water, and EF-104 (manufactured by Tochem Products) was added as a surfactant to a concentration of 0.1 wt%. Benzotriazole (BT) was used as a rust preventive agent, and the concentration was added to be 0.01 to 0.5 mol / l. The process of forming the phosphate chemical conversion film on the magnetic powder of Nd ₂ Fe ₁₄ B was carried out by the following method.

  (1) 5 ml of a phosphating solution was added to 100 g of magnetic powder obtained by pulverizing a NdFeB-based ribbon, and mixed until it was confirmed that the entire magnetic powder for rare earth magnets was wetted.

(2) The rare earth magnet magnetic powder subjected to the phosphatization film forming process of (1) above is heated at 180 ° C.
Heat treatment was performed for 30 minutes under a reduced pressure of 2 to 5 torr.

The SiO ₂ precursor, which is a binder, contains 25 ml of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, the average is 4), 4.8 ml of water, dehydrated A solution obtained by mixing 75 ml of methyl alcohol and 0.05 ml of dibutyltin dilaurate and leaving it at a temperature of 25 ° C. for 2 days and nights was used.

(1) Filling the mold with Nd ₂ Fe ₁₄ B magnetic powder that has been subjected to the above-mentioned phosphatization film formation treatment, and measuring the magnetic properties at a pressure of 16 t / cm ² , the length is 10 mm, the width is 10 mm, and the thickness is 5 mm. In addition, a compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm was prepared for strength measurement.

(2) The SiO ₂ precursor solution, which is a binder, placed in a bat so that the pressing direction is in the horizontal direction and left at a temperature of 25 ° C. for two days and nights. Was injected into the vat so that the liquid level was 1 mm / min in the vertical direction. The SiO ₂ precursor solution was poured into the vat until it was finally 5 mm above the upper surface of the compression molded specimen.

(3) The compression molding test piece used in the above (2) was arranged, and a bat filled with the SiO ₂ precursor solution was set in a vacuum vessel and gradually exhausted to about 80 Pa. The sample was left until the generation of bubbles from the surface of the compression molded test piece was reduced.

(4) The compression molded test piece was placed, the internal pressure of the vacuum vessel in which the bat filled with the SiO ₂ precursor solution was set was gradually returned to atmospheric pressure, and the compression molded test piece was taken out from the SiO ₂ precursor solution. .

(5) The compression molding test piece impregnated with the SiO ₂ precursor solution prepared in the above (4) is set in a vacuum drying furnace, and the compression molding test piece is subjected to a pressure of 1 to 3 Pa at 150 ° C. Vacuum heat treatment was applied.

  (6) The specific resistance was measured by the four-probe method for the compression molded test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm produced in the above (5).

  (7) Further, a pulse magnetic field of 30 kOe or more was applied to the compression molded test piece whose specific resistance was examined. The compression molded specimen was examined for magnetic properties.

  (8) A mechanical bending test was performed using the compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm prepared in (5) above. For the bending test, a compression molded body having a sample shape of 15 mm × 10 mm × 2 mm was used, and the bending strength was evaluated by a three-point bending test with a distance between supporting points of 12 mm.

Regarding the magnetic properties of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (5) above, the residual magnetic flux density is improved by 20-30% compared to the resin-containing bond magnet (Comparative Example 1). are possible, the demagnetization curve was measured at 20 ° C., the value of residual magnetic flux density and coercivity and SiO ₂ before impregnated with the molded body after SiO ₂ infiltration and heating were almost the same. Further, the thermal demagnetization factor after 1 hour of holding at 200 ° C. in the atmosphere is 3.0% for the SiO ₂ impregnated bonded magnet, which is smaller than the thermal demagnetization factor (5%) without SiO ₂ impregnation. Further, the irreversible thermal demagnetization rate is 1% or less after the SiO ₂ impregnation heat treatment after being held in the atmosphere at 200 ° C. for 1 hour, and is smaller than the value close to 3% in the case of no SiO ₂ impregnation. This is because SiO ₂ suppresses deterioration due to oxidation of magnetic powder. The bending strength of the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (7) above is ₂ MPa or less before SiO ₂ impregnation, but has a bending strength of 100 MPa or more after SiO ₂ impregnation heat treatment. It was possible to produce a molded body. Further, the specific resistance of the magnet is about 100 times or more that of the sintered type rare earth magnet, and is equivalent to that of the compressed type rare earth bonded magnet. . Therefore, the eddy current loss is small, and it has good characteristics.

From the results of this example, the rare earth bonded magnet impregnated in the rare earth magnet molded body produced by the cold forming method without using the low-viscosity SiO ₂ precursor of the present invention is compared with a normal resin-containing rare earth bonded magnet. Thus, it has been found that the magnetic properties are 20-30%, the bending strength is about 3 times, the irreversible thermal demagnetization rate is reduced to less than half, and the magnet can be highly reliable.

[Example 11 of permanent magnet]
In this example, magnetic powder obtained by pulverizing a NdFeB-based ribbon similar to [Example 1] was used for the rare earth magnet magnetic powder. The treatment liquid for forming the phosphate chemical conversion film was prepared as follows. 20 g of phosphoric acid, 4 g of boric acid and 4 g of MgO as a metal oxide were dissolved in 1 l of water, and benzotriazole (BT) was added as a rust preventive to 0.04 mol / l. EF-104 (manufactured by Tochem Products) is used as a surfactant, and its concentration is 0.01 to 1.
It added so that it might become wt%. The process of forming the phosphate chemical conversion film on the magnetic powder of Nd ₂ Fe ₁₄ B was carried out by the following method.

  (1) 5 ml of a phosphating solution for 100 g of magnetic powder obtained by pulverizing a NdFeB-based ribbon was added and mixed until it was confirmed that the entire magnetic powder for a rare earth magnet was wetted.

  (2) The magnetic powder for a rare earth magnet subjected to the phosphating film forming treatment of (1) was heat-treated at 180 ° C. for 30 minutes under a reduced pressure of 2 to 5 torr.

The SiO ₂ precursor, which is a binder, contains 25 ml of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, the average is 4), 4.8 ml of water, dehydrated A solution obtained by mixing 75 ml of methyl alcohol and 0.05 ml of dibutyltin dilaurate and leaving it at a temperature of 25 ° C. for 2 days and nights was used.

(1) Filling the mold with Nd ₂ Fe ₁₄ B magnetic powder that has been subjected to the above-mentioned phosphatization film formation treatment, and measuring the magnetic properties at a pressure of 16 t / cm ² , the length is 10 mm, the width is 10 mm, and the thickness is 5 mm. In addition, a compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm was prepared for strength measurement.

(2) The SiO ₂ precursor solution, which is a binder, placed in a bat so that the pressing direction is in the horizontal direction and left at a temperature of 25 ° C. for two days and nights. Was injected into the vat so that the liquid level was 1 mm / min in the vertical direction. The SiO ₂ precursor solution was poured into the vat until it was finally 5 mm above the upper surface of the compression molded specimen.

(3) The compression molding test piece used in the above (2) was arranged, and a bat filled with the SiO ₂ precursor solution was set in a vacuum vessel and gradually exhausted to about 80 Pa. The sample was left until the generation of bubbles from the surface of the compression molded test piece was reduced.

(4) The compression molding test piece is arranged, and the internal pressure of the vacuum vessel in which the bat filled with the SiO ₂ precursor solution is set is gradually returned to the atmospheric pressure, and the compression molding test piece is taken out from the SiO ₂ precursor solution. It was.

(5) The compression molding test piece impregnated with the SiO ₂ precursor solution prepared in the above (4) is set in a vacuum drying furnace, and the compression molding test piece is subjected to a pressure of 1 to 3 Pa at 150 ° C. Vacuum heat treatment was applied.

  (6) The specific resistance was measured by the four-probe method for the compression molded test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm produced in the above (5).

  (7) Further, a pulse magnetic field of 30 kOe or more was applied to the compression molded test piece whose specific resistance was examined. The compression molded specimen was examined for magnetic properties.

  (8) A mechanical bending test was performed using the compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm prepared in (5) above. For the bending test, a compression molded body having a sample shape of 15 mm × 10 mm × 2 mm was used, and the bending strength was evaluated by a three-point bending test with a distance between supporting points of 12 mm.

Regarding the magnetic properties of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (5), the residual magnetic flux density can be improved by 20-30% compared to the resin-containing bond magnet (Comparative Example 1). , and the demagnetization curve was measured at 20 ° C., the value of residual magnetic flux density and coercivity and SiO ₂ before impregnated with the molded body after SiO ₂ infiltration and heating were almost the same. Further, the thermal demagnetization factor after 1 hour of holding at 200 ° C. in the atmosphere is 3.0% for the SiO ₂ impregnated bonded magnet, which is smaller than the thermal demagnetization factor (5%) without SiO ₂ impregnation. Furthermore, the irreversible heat demagnetization rate is also maintained in the atmosphere at 200 ° C. for 1 hour,
It is 1% or less after the SiO ₂ impregnation heat treatment and is smaller than a value close to 3% in the case of no SiO ₂ impregnation. This is because SiO ₂ suppresses deterioration due to oxidation of magnetic powder.

The bending strength of the compression-molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (7) above is ₂ MPa or less before SiO ₂ impregnation, but has a bending strength of 90 MPa or more after SiO ₂ impregnation heat treatment. It was possible to produce a molded body.

  Further, the specific resistance of the magnet is about 100 times or more that of the sintered type rare earth magnet, and is equivalent to that of the compressed type rare earth bonded magnet. . Therefore, the eddy current loss is small, and it has good characteristics.

From the results of this example, the rare earth bonded magnet impregnated in the rare earth magnet molded body produced by the cold forming method without using the low-viscosity SiO ₂ precursor of the present invention is compared with a normal resin-containing rare earth bonded magnet. Thus, it has been found that the magnetic properties are 20-30%, the bending strength is about 3 times, the irreversible thermal demagnetization rate is reduced to less than half, and the magnet can be highly reliable.

[Example 12 of permanent magnet]
In this example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used for the rare earth magnet magnetic powder.

The treatment liquid for forming the phosphate chemical conversion film was prepared as follows. Dissolve 20 g of phosphoric acid, 4 g of boric acid, 4 g of MgO as a metal oxide in 1 l of water, and use EF- as a surfactant.
104 (manufactured by Tochem Products) was added at 0.1 wt%, and benzotriazole (BT) as a rust inhibitor was added at 0.04 mol / l. The process of forming the phosphate chemical conversion film on the magnetic powder of Nd ₂ Fe ₁₄ B was carried out by the following method.

  (1) 2.5 to 30 ml of phosphating solution was added to 100 g of magnetic powder obtained by pulverizing a NdFeB-based ribbon, and mixed until it was confirmed that the entire magnetic powder for rare earth magnets was wet.

  (2) The magnetic powder for a rare earth magnet subjected to the phosphating film forming treatment of (1) was heat-treated at 180 ° C. for 30 minutes under a reduced pressure of 2 to 5 torr.

The SiO ₂ precursor, which is a binder, contains 25 ml of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, the average is 4), 4.8 ml of water, dehydrated A solution obtained by mixing 75 ml of methyl alcohol and 0.05 ml of dibutyltin dilaurate and leaving it at a temperature of 25 ° C. for 2 days and nights was used.

(1) Filling the mold with Nd ₂ Fe ₁₄ B magnetic powder that has been subjected to the above-mentioned phosphatization film formation treatment, and measuring the magnetic properties at a pressure of 16 t / cm ² , the length is 10 mm, the width is 10 mm, and the thickness is 5 mm. In addition, a compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm was prepared for strength measurement.

(2) The SiO ₂ precursor solution, which is a binder, placed in a bat so that the pressing direction is in the horizontal direction and left at a temperature of 25 ° C. for two days and nights. Was injected into the vat so that the liquid level was 1 mm / min in the vertical direction. The SiO ₂ precursor solution was poured into the vat until it was finally 5 mm above the upper surface of the compression molded specimen.

(3) The compression molding test piece used in the above (2) was arranged, and a bat filled with the SiO ₂ precursor solution was set in a vacuum vessel and gradually exhausted to about 80 Pa. The sample was left until the generation of bubbles from the surface of the compression molded test piece was reduced.

(4) The compression molded test piece was placed, the internal pressure of the vacuum vessel in which the bat filled with the SiO ₂ precursor solution was set was gradually returned to atmospheric pressure, and the compression molded test piece was taken out from the SiO ₂ precursor solution. .

(5) The compression molding test piece impregnated with the SiO ₂ precursor solution prepared in the above (4) is set in a vacuum drying furnace, and the compression molding test piece is subjected to a pressure of 1 to 3 Pa at 150 ° C. Vacuum heat treatment was applied.

  (6) The specific resistance was measured by the four-probe method for the compression molded test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm produced in the above (5).

  (7) Further, a pulse magnetic field of 30 kOe or more was applied to the compression molded test piece whose specific resistance was examined. The compression molded specimen was examined for magnetic properties.

  (8) A mechanical bending test was performed using the compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm prepared in (5) above. For the bending test, a compression molded body having a sample shape of 15 mm × 10 mm × 2 mm was used, and the bending strength was evaluated by a three-point bending test with a distance between supporting points of 12 mm.

Regarding the magnetic properties of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (5) above, the residual magnetic flux density is improved by 20-30% compared to the resin-containing bond magnet (Comparative Example 1). are possible, the demagnetization curve was measured at 20 ° C., the value of residual magnetic flux density and coercivity and SiO ₂ before impregnated with the molded body after SiO ₂ infiltration and heating were almost the same. Further, the thermal demagnetization factor after 1 hour of holding at 200 ° C. in the atmosphere is 3.0% for the SiO ₂ impregnated bonded magnet, which is smaller than the thermal demagnetization factor (5%) without SiO ₂ impregnation. Further, the irreversible thermal demagnetization rate is 1% or less after the SiO ₂ impregnation heat treatment after being held in the atmosphere at 200 ° C. for 1 hour, and is smaller than the value close to 3% in the case of no SiO ₂ impregnation. This is because SiO ₂ suppresses deterioration due to oxidation of magnetic powder.

The bending strength of the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (7) above is ₂ MPa or less before SiO ₂ impregnation, but has a bending strength of 100 MPa or more after SiO ₂ impregnation heat treatment. It was possible to produce a molded body.

  Further, the specific resistance of the magnet is about 100 times or more that of the sintered type rare earth magnet, and is equivalent to that of the compressed type rare earth bonded magnet. . Therefore, the eddy current loss is small, and it has good characteristics.

From the results of this example, the rare earth bonded magnet impregnated in the rare earth magnet molded body produced by the cold forming method without using the low-viscosity SiO ₂ precursor of the present invention is compared with a normal resin-containing rare earth bonded magnet. Thus, it has been found that the magnetic properties are 20-30%, the bending strength is about 3 times, the irreversible thermal demagnetization rate is reduced to less than half, and the magnet can be highly reliable.

[Comparative example 1 of permanent magnet]
In this comparative example, magnetic powder obtained by pulverizing a NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used as the rare earth magnet magnetic powder.

  (1) The rare earth magnet magnetic powder and a solid epoxy resin having a size of 100 μm or less (EPX6136 manufactured by Somaru) were mixed using a V mixer so that the volume might be 0 to 20%.

(2) The rare earth magnet magnetic powder produced in (1) above and a compound of resin were loaded into a mold and subjected to heat compression molding at 80 ° C. in an inert gas atmosphere under a molding pressure of 16 t / cm ² . . The produced magnet is 10 mm long, 10 mm wide and 5 mm thick for measuring magnetic properties, and 15 mm long, 10 mm wide and 2 mm thick for measuring strength.

  (3) Resin curing of the bonded magnet produced in (2) was performed in a nitrogen gas at 170 ° C. for 1 hour.

  (4) The specific resistance was measured by the four-probe method on the compression molded test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm produced in the above (3).

  (5) Further, a pulse magnetic field of 30 kOe or more was applied to the compression molded test piece whose specific resistance was examined. The compression molded specimen was examined for magnetic properties.

  (6) A mechanical bending test was performed using the compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm produced in (3) above. For the bending test, a compression molded body having a sample shape of 15 mm × 10 mm × 2 mm was used, and the bending strength was evaluated by a three-point bending test with a distance between supporting points of 12 mm.

The magnetic properties of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in the above (4) were examined. As a result, the residual magnetic flux density of the magnet decreased as the epoxy resin content in the magnet increased. Compared with the bonded magnets (Examples 1 to 5) produced by impregnating the SiO ₂ binder, when compared with a magnet having a bending strength of 50 MPa or more, the epoxy resin-containing bonded magnet has a magnetic flux density of 20 to 30. % Declined. Moreover, the thermal demagnetization rate after 1 hour of holding at 200 ° C. in the air is 5% for the epoxy resin-containing bond magnet and 3.0% for the SiO ₂ impregnated bond magnet. Furthermore, the irreversible heat demagnetization rate after returning to room temperature after 1 hour at 200 ° C. and re-magnetization is less than 1% when impregnated, [Embodiments 1-5 of permanent magnet], epoxy resin-containing bond In the case of the magnet [Comparative Example 1 of permanent magnet], the value was close to 3% and large. In addition to the suppression of irreversible thermal demagnetization, the epoxy resin-containing bond magnet was at a lower level than the SiO ₂ impregnated bond magnet in the PCT test and the salt spray test.

Further, the compression molded test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm produced in the above (4) was held at 225 ° C. for 1 hour in the atmosphere, and after cooling, a demagnetization curve was measured at 20 ° C. The magnetic field application direction was 10 mm. First, after magnetization with a magnetic field of +20 kOe, a magnetic field was applied alternately between ± 1 kOe and ± 10 kOe, and a demagnetization curve was measured. The result is shown in FIG. In FIG. 4, a magnet that has been impregnated with SiO ₂ under the condition 2) of [Example 1 of permanent magnet] and a compression-bonded magnet containing 15 vol% of an epoxy resin as a binder, as shown in this comparative example, The demagnetization curves are compared. In FIG. 4, the horizontal axis represents the applied magnetic field, and the vertical axis represents the magnetic flux density.
In the magnet impregnated with the SiO ₂ binder, the magnetic flux rapidly decreases when a magnetic field greater than −8 kOe is applied to the negative side. The compression-molded bonded magnet has a magnetic field whose value is smaller than that of the impregnated magnet, and the magnetic flux rapidly decreases. The magnetic field on the negative side of −5 kOe is significantly decreased. The residual magnetic flux density after applying a magnetic field of −10 kOe is 0.44 for the impregnated magnet, and 0.11 T for the compression-molded bonded magnet, and the residual magnetic flux density of the impregnated magnet is four times the value of the compression-molded bonded magnet. ing. This is because the magnetic anisotropy of the NdFeB crystals constituting each NdFeB powder is reduced by oxidizing the surface of each NdFeB powder and the crack surface of the NdFeB powder while the compression-molded bonded magnet is heated at 225 ° C. This is considered to be because the coercive force decreased and the magnetization was easily reversed by applying a negative magnetic field. On the other hand, in the impregnated magnet, the NdFeB powder and the crack surface are covered with the SiO ₂ film, so that it is considered that the reduction in coercive force is small as a result of preventing oxidation during heating in the atmosphere.

The bending strength of the compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm produced in the above (7) increases the bending strength when the epoxy resin content of the binder is increased.
With a vol%, the bending strength of the magnet is 48 MPa, which is necessary for a bonded magnet. The specific resistance of the epoxy resin-containing bonded magnet was equivalent to that of the SiO ₂ impregnated bonded magnet.

From the result of this comparative example, the epoxy resin-containing rare earth bonded magnet is compared with the rare earth bonded magnet in which the low viscosity SiO ₂ precursor of the present invention is impregnated into a rare earth magnet molded body prepared by a cold forming method without a resin. Thus, it was found that the magnetic properties were 20 to 30% lower, and the irreversible thermal demagnetization rate and the reliability of the magnet were low.

  In addition, in this comparative example, the evaluation result of the epoxy resin containing bond magnet which changed the volume fraction of resin (The resin volume fraction in the magnetic powder for resin and rare earth magnets) is summarized in Table 5.

[Comparative example 2 of permanent magnet]
In this comparative example, magnetic powder obtained by pulverizing a NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used as the rare earth magnet magnetic powder.

The SiO ₂ precursor as a binder includes 1 ml of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, average is 4), 0.19 ml of water, A solution obtained by mixing 99 ml of dehydrated methyl alcohol and 0.05 ml of dibutyltin dilaurate and leaving it at a temperature of 25 ° C. for two days and nights was used.

The viscosity of the SiO ₂ precursor solution was measured at a temperature of 30 ° C. using an Ostwald viscometer.

(1) The above Nd ₂ Fe ₁₄ B magnetic powder is filled in a mold, and a test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm is used for measuring magnetic properties at a pressure of 16 t / cm ² . A compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm was prepared.

(2) The compression-molded test piece prepared in (1) above is placed in the bat so that the pressing direction is horizontal, and the SiO ₂ precursor solution as the binder is placed vertically in the bat. Injection was performed so as to be 1 mm / min in the direction. The SiO ₂ precursor solution was poured into the vat until it was finally 5 mm above the upper surface of the compression molded specimen.

(3) The compression molding test piece used in the above (2) was arranged, and a bat filled with the SiO ₂ precursor solution was set in a vacuum vessel and gradually exhausted to about 80 Pa. The sample was left until the generation of bubbles from the surface of the compression molded test piece was reduced.

(4) The compression molded test piece was placed, the internal pressure of the vacuum vessel in which the bat filled with the SiO ₂ precursor solution was set was gradually returned to atmospheric pressure, and the compression molded test piece was taken out from the SiO ₂ precursor solution. .

(5) The compression molding test piece impregnated with the SiO ₂ precursor solution prepared in the above (4) is set in a vacuum drying furnace, and the compression molding test piece is subjected to a pressure of 1 to 3 Pa at 150 ° C. Vacuum heat treatment was applied.

  (6) The specific resistance was measured by the four-probe method for the compression molded test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm produced in the above (5).

  (7) Further, a pulse magnetic field of 30 kOe or more was applied to the compression molded test piece whose specific resistance was examined. The compression molded specimen was examined for magnetic properties.

  (8) A mechanical bending test was performed using the compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm prepared in (5) above. For the bending test, a compression molded body having a sample shape of 15 mm × 10 mm × 2 mm was used, and the bending strength was evaluated by a three-point bending test with a distance between supporting points of 12 mm.

Regarding the magnetic properties of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (5) above, the residual magnetic flux density is improved by 20-30% compared to the resin-containing bond magnet (Comparative Example 1). are possible, the demagnetization curve was measured at 20 ° C., the value of residual magnetic flux density and coercivity and SiO ₂ before impregnated with the molded body after SiO ₂ infiltration and heating were almost the same. Further, the thermal demagnetization factor after 1 hour of holding at 200 ° C. in the atmosphere is 3.0% for the SiO ₂ impregnated bonded magnet, which is smaller than the thermal demagnetization factor (5%) without SiO ₂ impregnation. Furthermore, the irreversible thermal demagnetization rate after returning to room temperature after 1 hour at 200 ° C. and re-magnetization is less than 1% when the impregnation treatment is performed, whereas it is close to 3% in the case of an epoxy bond magnet [ Permanent magnet comparative example 1].

However, the bending strength of the compression molded test piece of 15 mm in length, 10 mm in width, and 2 mm in thickness produced in the above (7) is a low level, and the SiO ₂ impregnated bond magnet of this comparative example is compared with the epoxy resin-containing bond magnet. Only a value of about 1/10 was obtained. This is because the content of the SiO ₂ precursor in the binder in this comparative example is 1 vol%, which is 1 to 2 orders of magnitude less than the content of the SiO ₂ precursor in the binder in the examples. Even if the bending strength of SiO ₂ alone is large, the content in the magnet is too small.

  In conclusion, the magnet of this comparative example has a disadvantage that the magnet strength is low, and depending on the object of use, it is necessary to consider the bending strength.

  Table 6 summarizes various characteristics of this comparative example and 1), 2), and [Comparative example 4 of permanent magnet] described later [Comparative example 3 of permanent magnet].

[Comparative example 3 of permanent magnet]
In this comparative example, magnetic powder obtained by pulverizing a NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used as the rare earth magnet magnetic powder.

The following two solutions were used for the SiO ₂ precursor as a binder.

1) 25 ml of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, average is 4), 0.19 ml of water, 75 ml of dehydrated methyl alcohol, dibutyltin dilaurate 0 0.05 ml was mixed and left at a temperature of 25 ° C. for 2 days and nights.

_{2) CH 3 O- (Si (} CH 3 O) 2 -O) m -CH 3 (m is 3-5, average 4) 25 ml, water 24 ml, dried ethyl alcohol 75 ml, dibutyltin dilaurate 0.05ml And left at a temperature of 25 ° C. for 2 days and nights.

The viscosities of the SiO ₂ precursor solutions 1) and 2) were measured at a temperature of 30 ° C. using an Ostwald viscometer.

(1) The above Nd ₂ Fe ₁₄ B magnetic powder is filled in a mold, and a test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm is used for measuring magnetic properties at a pressure of 16 t / cm ² . A compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm was prepared.

(2) The compression molded test piece prepared in (1) above is placed in the bat so that the pressing direction is horizontal, and the SiO ₂ precursor solution of 1) and 2) as the binder is placed in the bat. The liquid surface was injected at 1 mm / min in the vertical direction. The SiO ₂ precursor solution was poured into the vat until it was finally 5 mm above the upper surface of the compression molded specimen.

(3) The compression molding test piece used in the above (2) was arranged, and a bat filled with the SiO ₂ precursor solution was set in a vacuum vessel and gradually exhausted to about 80 Pa. The sample was left until the generation of bubbles from the surface of the compression molded test piece was reduced.

(4) The compression molded test piece was placed, the internal pressure of the vacuum vessel in which the bat filled with the SiO ₂ precursor solution was set was gradually returned to atmospheric pressure, and the compression molded test piece was taken out from the SiO ₂ precursor solution. .

(5) The compression molding test piece impregnated with the SiO ₂ precursor solution prepared in the above (4) is set in a vacuum drying furnace, and the compression molding test piece is subjected to a pressure of 1 to 3 Pa at 150 ° C. Vacuum heat treatment was applied.

  (6) The specific resistance was measured by the four-probe method for the compression molded test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm produced in the above (5).

  (7) Further, a pulse magnetic field of 30 kOe or more was applied to the compression molded test piece whose specific resistance was examined. The compression molded specimen was examined for magnetic properties.

  (8) A mechanical bending test was performed using the compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm prepared in (5) above. For the bending test, a compression molded body having a sample shape of 15 mm × 10 mm × 2 mm was used, and the bending strength was evaluated by a three-point bending test with a distance between supporting points of 12 mm.

Regarding 1) of [Comparative Example 3 of Permanent Magnet], the residual magnetic flux density is a resin-containing bond magnet [permanently] for the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (5) above. compared to Comparative example 1] of the magnet, improved 20-30%, 20 demagnetization curve measured at ℃, the residual magnetic flux density and coercive in the shaped body after the SiO ₂ before impregnated and SiO ₂ infiltration and heating The values of magnetic force almost coincided. Further, the thermal demagnetization factor after 1 hour of holding at 200 ° C. in the atmosphere is 3.0% for the SiO ₂ impregnated bonded magnet, which is smaller than the thermal demagnetization factor (5%) without SiO ₂ impregnation. Further, the irreversible thermal demagnetization rate after returning to room temperature after 1 hour at 200 ° C. and re-magnetization is less than 1% when the impregnation treatment is performed, whereas in the case of epoxy-based bonded magnet [Comparative Example 1 of permanent magnet] 3 The value was close to%.

However, the bending strength of the compression molded test piece of 15 mm in length, 10 mm in width, and 2 mm in thickness produced in the above (7) is a low level, and the SiO ₂ impregnated bond magnet of this comparative example is compared with the epoxy resin-containing bond magnet. Only a value of about 1/6 was obtained. This is because the amount of water added in the binder in this comparative example is small, so the hydrolysis of the methoxy group in the SiO ₂ precursor material shown in chemical reaction formula 1 does not proceed, so silanol groups do not form, and SiO 2 _This is because the dehydration condensation reaction between silanol groups in the thermosetting reaction of the _two precursors does not occur, so that the amount of SiO ₂ generated after thermosetting is small and the bending strength of the SiO ₂ -impregnated bonded magnet is low.

  In conclusion, since the magnet of 1) of [Comparative Example 3 of permanent magnet] has a low magnet strength, it is desirable to use it by fully considering the relationship of the magnet strength in the object of use.

About 2) of Comparative Example 3 of the permanent magnet, the longitudinal 15mm prepared in (7), lateral 10 mm, the flexural strength of the compression molded test piece having a thickness of 2mm but is 2MPa or less before SiO ₂ impregnation, SiO ₂ After the impregnation heat treatment, it was possible to produce a magnet compact having a bending strength of 170 MPa.

Regarding the magnetic properties of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (5), the residual magnetic flux density is improved by 20% compared to the resin-containing bonded magnet [Comparative Example 1 of permanent magnet]. are possible, the demagnetization curve was measured at 20 ° C., the value of residual magnetic flux density and coercivity and SiO ₂ before impregnated with the molded body after SiO ₂ infiltration and heating were almost the same. However, the thermal demagnetization rate after 1 hour of holding at 200 ° C. in the atmosphere was 4.0% in this comparative example, which was a large value compared to 3.0% in the SiO ₂ impregnated bonded magnet in the example. Further, the irreversible thermal demagnetization rate after returning to room temperature after 1 hour at 200 ° C. and re-magnetization is less than 1% when the SiO ₂ impregnation treatment is performed in the example, whereas in this comparative example, the value is close to 2%. Met. This was found to be due to the fact that the SiO ₂ precursor solution penetrated into the magnet only up to about 1 mm from the magnet surface. Therefore, the magnetic powder in the central part of the magnet causes oxidative degradation during heating in the atmosphere, which is the reason why the magnet of this comparative example has a larger irreversible heat demagnetization rate than the magnet of the example.

  From this result, although the bonded magnet of this comparative example is not inferior to the conventional epoxy-based bonded magnet, the long-term reliability may be lower than that of the conventional epoxy-based bonded magnet. It is desirable to use it in consideration of oxidative deterioration in the object of use.

[Comparative example 4 of permanent magnet]
In this comparative example, magnetic powder obtained by pulverizing a NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used as the rare earth magnet magnetic powder. The SiO ₂ precursor that is the binder contains CH ₃ O—
_{(Si (CH 3 O) 2} -O) m -CH 3 (m is 3-5, average 4) 25 ml, mixed water 9.6 ml, dehydrated methanol 75 ml, dibutyltin dilaurate 0.05 ml, The solution which was left standing at a temperature of 25 ° C. for 6 days was used. The viscosity of the SiO ₂ precursor solution was measured at a temperature of 30 ° C. using an Ostwald viscometer.

(1) The above Nd ₂ Fe ₁₄ B magnetic powder is filled in a mold, and a test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm is used for measuring magnetic properties at a pressure of 16 t / cm ² . A compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm was prepared.

(2) The compression-molded test piece prepared in (1) above is placed in the bat so that the pressing direction is horizontal, and the SiO ₂ precursor solution as the binder is placed vertically in the bat. Injection was performed so as to be 1 mm / min in the direction. The SiO ₂ precursor solution was poured into the vat until it was finally 5 mm above the upper surface of the compression molded specimen.

(3) The compression molding test piece used in the above (2) was arranged, and a bat filled with the SiO ₂ precursor solution was set in a vacuum vessel and gradually exhausted to about 80 Pa. The sample was left until the generation of bubbles from the surface of the compression molded test piece was reduced.

(4) The compression molded test piece was placed, the internal pressure of the vacuum vessel in which the bat filled with the SiO ₂ precursor solution was set was gradually returned to atmospheric pressure, and the compression molded test piece was taken out from the SiO ₂ precursor solution. .

(5) The compression molding test piece impregnated with the SiO ₂ precursor solution prepared in the above (4) is set in a vacuum drying furnace, and the compression molding test piece is subjected to a pressure of 1 to 3 Pa at 150 ° C. Vacuum heat treatment was applied.

  (6) The specific resistance was measured by the four-probe method for the compression molded test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm produced in the above (5).

  (7) Further, a pulse magnetic field of 30 kOe or more was applied to the compression molded test piece whose specific resistance was examined. The compression molded specimen was examined for magnetic properties.

  (8) A mechanical bending test was performed using the compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm prepared in (5) above. For the bending test, a compression molded body having a sample shape of 15 mm × 10 mm × 2 mm was used, and the bending strength was evaluated by a three-point bending test with a distance between supporting points of 12 mm.

The bending strength of the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (7) above is ₂ MPa or less before the SiO ₂ impregnation, but the magnet forming has a bending strength of 190 MPa after the SiO ₂ impregnation heat treatment. It was possible to make a body.

Regarding the magnetic properties of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (5) above, the residual magnetic flux density can be improved by 20% compared to the resin-containing bond magnet (Comparative Example 1). There the demagnetization curve measured at 20 ° C., the value of residual magnetic flux density and coercivity and SiO ₂ before impregnated with the molded body after SiO ₂ infiltration and heating were almost the same. However, the thermal demagnetization rate after 1 hour of holding at 200 ° C. in the atmosphere was 3.6% in this comparative example, which was a large value compared with 3.0% in the SiO ₂ impregnated bonded magnet in the example. Furthermore, the irreversible thermal demagnetization rate after returning to room temperature after 1 hour at 200 ° C. and re-magnetization is less than 1% when the SiO ₂ impregnation treatment is performed in the example, whereas 1.6% in this comparative example. It became the value of. This was found to be due to the fact that the SiO ₂ precursor solution penetrated into the magnet only up to about 2 mm from the magnet surface. Therefore, the magnetic powder in the central part of the magnet causes oxidative degradation during heating in the atmosphere, which is the reason why the magnet of this comparative example has a larger irreversible heat demagnetization rate than the magnet of the example.

  From this result, although the bonded magnet of this comparative example is not inferior to the conventional epoxy-based bonded magnet, the long-term reliability may be lower than that of the conventional epoxy-based bonded magnet. It is desirable to use it in consideration of this point.

[Comparative example 5 of permanent magnet]
In this comparative example, magnetic powder obtained by pulverizing a NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used as the rare earth magnet magnetic powder. A treatment liquid for forming a rare earth fluoride or alkaline earth metal fluoride coat film was prepared as follows.

  (1) A salt having high solubility in water, for example, in the case of Nd, Nd acetate Nd or 4 g of nitrate Nd was introduced into 100 ml of water, and completely dissolved using a shaker or an ultrasonic stirrer.

(2) Hydrofluoric acid diluted to 10% was gradually added in an amount equivalent to the chemical reaction for producing NdF ₃ .

(3) The solution in which the gel-like precipitate NdF ₃ was produced was stirred for 1 hour or more using an ultrasonic stirrer.

  (4) After centrifuging at 4000 to 6000 rpm, the supernatant was removed and approximately the same amount of methanol was added.

(5) A methanol solution containing gel-like NdF ₃ was stirred to form a complete suspension, and then stirred for 1 hour or more using an ultrasonic stirrer.

  (6) The above operations (4) and (5) were repeated 3 to 10 times until no anion such as acetate ion or nitrate ion was detected.

(7) Finally, in the case of NdF ₃ , an almost transparent sol-like NdF ₃ was obtained. A methanol solution containing 1 g / 5 ml of NdF ₃ was used as the treatment liquid.

The process of forming the rare earth fluoride or alkaline earth metal fluoride coat film on the magnetic powder of Nd ₂ Fe ₁₄ B was carried out by the following method.

In the case of NdF ₃ coat film formation process: NdF ₃ concentration 1 g / 10 ml translucent sol solution (1) Add 15 ml of NdF ₃ coat film forming treatment liquid to 100 g of magnetic powder obtained by pulverizing NdFeB thin ribbon, The mixing was performed until it was confirmed that the entire magnetic powder for rare earth magnet was wet.

(2) Methanol removal of the solvent was performed on the magnetic powder for rare earth magnets subjected to the NdF ₃ coat film forming treatment of (1) above under a reduced pressure of 2 to 5 torr.

(3) The rare earth magnet magnetic powder from which the solvent of (2) has been removed is transferred to a quartz boat and heat-treated at 200 ° C. for 30 minutes and 400 ° C. for 30 minutes under a reduced pressure of 1 × 10 ⁻⁵ torr. It was.

(4) After the magnetic powder heat-treated in (3) above is transferred to a lid made by Macor (manufactured by Riken Denshi), heat treatment is performed at 700 ° C. for 30 minutes under a reduced pressure of 1 × 10 ⁻⁵ torr. went.

(5) Nd ₂ Fe ₁₄ B magnetic powder coated with the rare earth fluoride or alkaline earth metal fluoride coating film is filled in a mold, and is 10 mm in length and 16 mm in width for measuring magnetic properties at a pressure of 16 t / cm ^2. 10
A test piece having a thickness of 5 mm and a thickness of 5 mm was prepared, and a compression test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm was prepared for strength measurement.

  (6) The specific resistance was measured by the four-probe method for the compression molded test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm produced in the above (5).

  (7) Further, a pulse magnetic field of 30 kOe or more was applied to the compression molded test piece whose specific resistance was examined. The compression molded specimen was examined for magnetic properties.

  (8) A mechanical bending test was performed using the compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm prepared in (5) above. For the bending test, a compression molded body having a sample shape of 15 mm × 10 mm × 2 mm was used, and the bending strength was evaluated by a three-point bending test with a distance between supporting points of 12 mm.

Regarding the magnetic properties of the compression molded test piece of 10mm length, 10mm width and 5mm thickness produced in (5) above, the residual magnetic flux density can be improved by about 20% compared to the resin-containing bond magnet (Comparative Example 1). , and the demagnetization curve was measured at 20 ° C., the value of residual magnetic flux density and coercivity and SiO ₂ before impregnated with the molded body after SiO ₂ infiltration and heating were almost the same. Further, the thermal demagnetization factor after 1 hour of holding at 200 ° C. in the atmosphere was 3.0% in this comparative example, which was equivalent to 3.0% in the SiO ₂ impregnated bonded magnet in the example. Further, the irreversible thermal demagnetization rate after returning to room temperature after 1 hour at 200 ° C. and re-magnetization is less than 1% when the SiO ₂ impregnation treatment is performed in the example, whereas in this comparative example, it is less than 1%. Value. The results are shown in Table 7.

However, the bending strength of the compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm produced in (7) is 2.9 MPa because it is not impregnated with SiO _{2 in} this comparative example. The value was about 1/15 compared to the bond magnet.

  From this result, the bonded magnet of this comparative example has poor mechanical strength compared to the conventional epoxy-based bonded magnet, and attention should be paid to this point in use.

[Comparative example 6 of permanent magnet]
In this example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used for the rare earth magnet magnetic powder. Moreover, the process liquid which forms a phosphate chemical conversion treatment film was produced as follows.

  20 g of phosphoric acid, 4 g of boric acid and 4 g of MgO as a metal oxide were dissolved in 1 liter of water, and EF-104 (manufactured by Tochem Products) as a surfactant was added to 0.1 wt%. As a rust preventive agent, benzotriazole (BT) was added to 0.04 mol / l.

The process of forming the phosphate chemical conversion film on the magnetic powder of Nd ₂ Fe ₁₄ B was carried out by the following method. Table 4 shows the composition of the phosphating solution used.

  (1) 5 ml of a phosphating solution was added to 100 g of magnetic powder obtained by pulverizing a NdFeB-based ribbon, and mixed until it was confirmed that the entire magnetic powder for rare earth magnets was wetted.

(2) The rare earth magnet magnetic powder subjected to the phosphatization film forming process of (1) above is heated at 180 ° C.
Heat treatment was performed for 30 minutes under a reduced pressure of 2 to 5 torr.

(3) A magnetic mold of Nd ₂ Fe ₁₄ B subjected to the above phosphatization film formation treatment is filled in a mold, and at a pressure of 16 t / cm ² , 10 mm in length, 10 mm in width, and 5 mm in thickness for measuring magnetic properties. In addition, a compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm was prepared for strength measurement.

  (4) The specific resistance was measured by the four-probe method on the compression molded test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm produced in the above (3).

  (5) Further, a pulse magnetic field of 30 kOe or more was applied to the compression molded test piece whose specific resistance was examined. The compression molded specimen was examined for magnetic properties.

  (6) A mechanical bending test was carried out using the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (3) above. For the bending test, a compression molded body having a sample shape of 15 mm × 10 mm × 2 mm was used, and the bending strength was evaluated by a three-point bending test with a distance between supporting points of 12 mm.

Regarding the magnetic characteristics of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (3), the residual magnetic flux density is about 25% compared to the resin-containing bond magnet [Comparative Example 1 of permanent magnet]. a possible improvement the demagnetization curve measured at 20 ° C., the value of residual magnetic flux density and coercivity and SiO ₂ before impregnated with the molded body after SiO ₂ infiltration and heating were almost the same. In addition, the thermal demagnetization factor after 1 hour of holding at 200 ° C. in the atmosphere was 3.1% in this comparative example, which was almost equivalent to 3.0% in the SiO ₂ impregnated bonded magnet in the example. Further, the irreversible thermal demagnetization rate after returning to room temperature after 1 hour at 200 ° C. and re-magnetization is less than 1% when the SiO ₂ impregnation treatment is performed in the example, whereas in this comparative example, it is 1.2%. Although there was a slight increase in the value, there was no significant difference (Table 7). However, with respect to the bending strength of the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in the above (5), since it was not impregnated with SiO _{2 in} this comparative example, a value of 2.9 MPa was obtained. The value was about 1/20 compared with the system bond magnet.

  From this result, the bonded magnet of this comparative example has poor mechanical strength compared to the conventional epoxy-based bonded magnet, and it is necessary to use this point with sufficient consideration in use.

  Although the present invention has been described with reference to the above-described embodiments, the magnet of the present invention has the following effects.

  1) Performance as a magnet is superior to conventional resin magnets.

  2) In addition to superior properties, it also has a strong strength as a magnet. It is possible to obtain a magnet that has excellent characteristics and strength that could not be obtained with a resin magnet.

  The effects 1) and 2) are achieved as described above, for example, as follows.

  It is necessary to infiltrate the binder solution into the gap between the magnetic powder of 1 μm or less and the magnetic powder, which is generated when the magnetic powder is compression molded without a resin. For this purpose, the viscosity of the binder solution must be 100 mPa · s or less, and the wettability of the magnetic powder and the binder solution must be high. Furthermore, it is important that the adhesive between the binder after curing and the magnetic powder is high, the mechanical strength of the binder is large, and the binder is continuously formed.

The viscosity of the binder solution depends on the size of the magnet, but when the thickness of the compression molded body is 5 mm or less and the gap between the magnetic powder and the magnetic powder is about 1 μm, the viscosity of the binder solution is about 100 mPa · s. It is possible to introduce the binder solution into the gap between the magnetic powders up to the center of the compression molded body. When the thickness of the compression molded body is 5 mm or more and the gap between the magnetic powder and the magnetic powder is about 1 μm, for example, in the compression molded body having a thickness of about 30 mm, the binder solution is introduced to the center of the compression molded body When the viscosity of the binder solution is about 100 mPa · s, the viscosity of the binder solution is 20 mPa · s or less, preferably 10 mPa · s or less. This is a viscosity that is one digit or more lower than that of a normal resin. For that purpose, it is necessary to control the hydrolysis amount of the alkoxy group in the alkoxysiloxane which is the precursor of SiO ₂ and to suppress the molecular weight of the alkoxysiloxane. That is, when an alkoxy group is hydrolyzed, a silanol group is generated. The silanol group easily undergoes a dehydration condensation reaction, and the dehydration condensation reaction means an increase in the molecular weight of the alkoxysiloxane. Further, since silanol groups generate hydrogen bonds with each other, the viscosity of the alkoxysiloxane solution that is the precursor of SiO ₂ increases. Specifically, the amount of water added to the hydrolysis reaction equivalent of alkoxysiloxane and the hydrolysis reaction conditions are controlled. As the solvent used for the binder solution, it is desirable to use alcohol because the alkoxy group in alkoxysiloxane has a fast dissociation reaction. The solvent alcohol is preferably methanol, ethanol, n-propanol or iso-propanol having a boiling point lower than that of water and a low viscosity, but the viscosity of the binder solution does not increase in several hours and the solvent has a boiling point lower than that of water. If it is, it can be used for manufacture of the magnet according to the present invention.

For the adhesion between the binder and the magnetic powder after curing, SiO ₂ precursor, which is binding agent is used in the present invention because the product after the heat treatment is SiO _2, the surface of the magnetic powder in the natural oxide film If covered, the adhesion between the surface of the magnetic powder and SiO ₂ is large, and rare earth magnets using SiO ₂ as the binder have a cohesive fracture surface of the magnetic powder or SiO ₂ when the magnet is broken. On the other hand, when a resin is used as the binder, the adhesion between the resin and the magnetic powder is generally smaller than that of the magnetic powder surface and SiO ₂ . Therefore, in a bonded magnet using a resin, the surface when the magnet is broken has both an interface between the resin and magnetic powder or a cohesive failure surface of the resin. Therefore, in order to improve the magnet strength, it is more advantageous to use SiO ₂ as the binder than to use the resin as the binder.

When the content of rare earth magnetic powder in the magnet is 75 vol% or more, a compression-molded type rare earth magnet is used, but the strength of the rare earth magnet after curing the binder is that of the binder after curing. Whether or not a continuum is generated has a great influence. This is because the breaking strength of the binder alone having the same area is larger than the breaking strength of the adhesive interface. When resin such as epoxy resin is used, if the resin volume fraction in the total solid content is 15 vol% or less, it cannot be said that the wettability between the resin and the rare earth magnetic powder is good. Does not become a continuum but is distributed in islands. On the other hand, as described above, the SiO ₂ precursor has good wettability with the rare earth magnetic powder. Therefore, the SiO ₂ precursor spreads continuously on the surface of the magnetic powder, and is cured by heat treatment in the continuously spread state. It becomes SiO ₂ . On the other hand, when the strength of the binder after curing is expressed in terms of bending strength, SiO ₂ is 1 to 3 orders of magnitude larger than that of the resin system. Therefore, the strength of the rare earth magnet after the binder is cured is much higher when the SiO ₂ precursor is used as the binder than when the resin is used.

Next, magnet materials more suitable for the magnet according to the present invention will be described. Rare earth magnet powder consists of a ferromagnetic main phase and other components. When the rare earth magnet is an Nd—Fe—B based magnet, the main phase is an Nd ₂ Fe ₁₄ B phase. Considering improvement of magnet characteristics, the rare earth magnet powder is preferably a magnet powder prepared by using the HDDR method or hot plastic working. Rare earth magnet powder
In addition to Nd—Fe—B magnets, Sm—Co magnets are exemplified. Considering the magnet characteristics of the obtained rare earth magnet and the manufacturing cost, Nd—Fe—B type magnets are preferable. However, the rare earth magnet of the present invention is not limited to Nd—Fe—B magnets. In some cases, two or more rare earth magnet powders may be mixed in the rare earth magnet. That is, two or more types of Nd—Fe—B magnets having different composition ratios may be included, and Nd—Fe—B magnets and Sm—Co magnets may be mixed.

  In the present specification, the “Nd—Fe—B magnet” is a concept including a form in which a part of Nd or Fe is substituted with another element. Nd may be substituted with other rare earth elements such as Dy and Tb. Only one of these may be used for substitution, or both may be used. The substitution can be performed by adjusting the blending amount of the raw material alloy. By such replacement, the coercive force of the Nd—Fe—B magnet can be improved. The amount of Nd to be substituted is preferably 0.01 atom% or more and 50 atom% or less with respect to Nd. If it is less than 0.01 atom%, the effect of substitution may be insufficient. If it exceeds 50 atom%, the residual magnetic flux density may not be maintained at a high level, and it is desirable to pay attention to the application in which the magnet is used.

  On the other hand, Fe may be substituted with other transition metals such as Co. By such substitution, the Curie temperature (Tc) of the Nd—Fe—B magnet can be increased and the operating temperature range can be expanded. The amount of Fe to be substituted is preferably 0.01 atom% or more and 30 atom% or less with respect to Fe. If it is less than 0.01 atom%, the effect of substitution may be insufficient. If it exceeds 30 atom%, the coercive force may decrease significantly, and it is desirable to pay attention to the application in which the magnet is used.

  The average particle diameter of the rare earth magnet powder in the rare earth magnet is preferably 1 to 500 μm. When the average particle size of the rare earth magnet powder is less than 1 μm, the specific surface area of the magnetic powder is large and the influence of oxidative degradation is great, and there is a concern that the magnet characteristics of a rare earth magnet using the rare earth magnet powder may be deteriorated. Therefore, in this case, it is desirable to pay attention to the usage state of the magnet.

On the other hand, if the average particle size of the rare earth magnet powder is larger than 500 μm, the magnet powder is crushed by the pressure at the time of manufacture, and it becomes difficult to obtain sufficient electric resistance. In addition, when an anisotropic magnet is manufactured using anisotropic rare earth magnet powder as a raw material, the main phase in rare earth magnet powder (Nd ₂ Fe _{14 in} Nd—Fe—B magnets) extends over a size exceeding 500 μm. It is difficult to align the orientation direction of the (B phase). The particle size of the rare earth magnet powder is controlled by adjusting the particle size of the rare earth magnet powder that is the raw material of the magnet. The average particle size of the rare earth magnet powder can be calculated from the SEM image.

  The present invention relates to an isotropic magnet manufactured from isotropic magnet powder, an isotropic magnet in which anisotropic magnet powder is randomly oriented, and an anisotropic magnet in which anisotropic magnet powder is oriented in a certain direction. Any of them can be applied. If a magnet having a high energy product is required, an anisotropic magnet using anisotropic magnet powder as a raw material and oriented in a magnetic field is suitable.

The rare earth magnet powder is produced by blending raw materials according to the composition of the rare earth magnet to be produced. When producing an Nd—Fe—B based magnet whose main phase is the Nd ₂ Fe ₁₄ B phase, a predetermined amount of Nd, Fe, and B is blended. As the rare earth magnet powder, one produced by a known method may be used, or a commercially available product may be used. Such rare earth magnet powder is an aggregate of a large number of crystal grains. The crystal grains constituting the rare earth magnet powder are suitable for improving the coercive force when the average particle diameter is not more than the single domain critical particle diameter. Specifically, the average grain size of the crystal grains is preferably 500 nm or less. In the HDDR method, the Nd—Fe—B alloy is hydrogenated to decompose the Nd ₂ Fe ₁₄ B compound as the main phase into three phases of NdH ₃ , α-Fe, and Fe ₂ B, Thereafter, Nd ₂ Fe ₁₄ B is again generated by forced dehydrogenation. The UPSET method is a technique in which an Nd—Fe—B alloy produced by an ultra-quenching method is subjected to plastic working hot after pulverization and temporary molding.

  As a use application of the magnet, an inorganic insulating film is preferably formed on the surface of the rare earth magnet powder under a condition where a high frequency magnetic field including harmonics is applied to the magnet. Thereby, the electrical resistance inside a magnet can be enlarged, an eddy current can be reduced, and the eddy current loss in a magnet can be reduced. As such an inorganic insulating film, a film formed by using a phosphating solution containing phosphoric acid, boric acid, and magnesium ions is preferable. In order to ensure the uniformity of the film thickness and the magnetic properties of the magnetic powder, the surface activity is required. It is desirable to use an agent and a rust inhibitor in combination. In particular, it is desirable that the surfactant is a perfluoroalkyl surfactant and the rust inhibitor is a benzotriazole rust inhibitor.

Furthermore, a fluoride coat film is desirable as the inorganic insulating film for the purpose of improving the insulating properties and magnetic characteristics of the magnetic powder. As the treatment liquid for forming the fluoride coat film, rare earth fluoride or alkaline earth metal fluoride is swollen in a solvent mainly composed of alcohol, and the rare earth fluoride or alkaline earth metal fluoride is used. Is preferably a solution in a sol state in which the average particle size is pulverized to 10 μm or less and dispersed in a solvent containing alcohol as a main component. In order to improve the magnetic properties, it is desirable to heat-treat the magnetic powder having the fluoride coat film formed on the surface in an atmosphere of 1 × 10 ⁻⁴ Pa or less and at a temperature of 600 to 700 ° C.

Next, the function and effect of the first embodiment will be described below. The magnets used in the first and second rotating electric machines 200 and 202 shown in FIG. 1 have the above-described structure, that is, a powder magnetic material and a binder having good wettability are used as magnets. Producing magnets by impregnation has at least one or more of the following effects. As described above, SiO ₂ is most suitable as a binder for the powder magnetic material and the precursor having good wettability.

  Effect 1 In the above-described magnet manufacturing process, there is no sintering process heated to a high temperature, so that the magnet can be manufactured easily.

  Since it is not the magnet which uses the epoxy resin called the effect 2 and a common bond magnet, the energy density of a magnet is large, and the rotary electric machine of a comparatively favorable characteristic can be obtained cheaply.

  Effect 3, after the magnet is molded with the magnet material, the binder can be cured at a relatively low temperature, and the shape and size of the molded magnet material are less changed. Since it can be manufactured with high accuracy with respect to the shape and dimensions of the magnet, high characteristics can be obtained as a motor or a generator. For example, the cogging torque due to a dimensional error can be reduced, and the harmonics of the magnetic flux density in the gap can be reduced by a complicated magnet shape. Even with a magnet material alone, the cutting after binding with a binder is very little and easy. For example, it is not a substantial magnet-shaped forming process, such as cutting the protruding portion of the adhesive, so that the process is easy. Since the conventional sintered magnet is heated to a high temperature for sintering, it shrinks in the process of lowering the temperature thereafter, and the shape of the magnet material changes. Therefore, in the conventional sintered magnet, it has been necessary to spend a lot of time for cutting for adjusting the shape and dimensions of the magnet after the sintering process. In the above-described embodiment, a necessary magnet shape can be obtained with extremely few cutting processes and, in some cases, without a cutting process.

  Effect 4, as described above, since the molding shape of the magnet material hardly changes in the subsequent binder impregnation or curing process, the magnet is manufactured while maintaining the curved shape of the magnet material by pressing or the like with high accuracy. It is possible. Theoretically, even if the thickness and shape of the preferred magnet are known, it is possible to achieve the curved shape of the magnet that was difficult to commercialize because there is no method that can be mass-produced, and it is possible to obtain a rotating electrical machine with good characteristics It is. More complex shapes than those shown in FIG. 5 are possible.

  Effect 5, sintered rare earth magnets have low electrical resistance and large loss and heat generation due to eddy currents. The magnet can form an insulating film on the surface of the powder magnet, and the eddy current loss and heat generation of the magnet can be greatly reduced. A rotating electrical machine for automobiles, particularly a rotating electrical machine used in a hybrid vehicle, may be used in an environment exceeding 100 degrees, and it is necessary to suppress heat generation due to eddy current in the magnet. In the above-described embodiment, since the electric resistance can be increased, the heat generation of the magnet can be reduced. Further, the loss of the rotating electrical machine can be reduced correspondingly, and the efficiency is improved.

[Second Embodiment]
Next, a second embodiment in which the permanent magnet rotating electrical machine of the present invention is applied to an on-vehicle electric actuator device electrical system will be described. In the second embodiment, an electric power steering device will be described as an example of the on-vehicle electric actuator device.

  First, the schematic configuration of the electric power steering apparatus of the present embodiment will be described with reference to FIG. FIG. 12 shows a system configuration of the electric power steering apparatus of the present embodiment.

  An electric power steering apparatus (hereinafter referred to as “EPS”) 300 of the present embodiment is a column type EPS that assists the steering shaft by providing a permanent magnet rotating electrical machine 401 in the vicinity of the steering shaft (column).

  The EPS includes a pinion type EPS that assists the pinion gear by providing a motor in the vicinity of the rack and pinion gear, and a rack cross type EPS that assists the rack by providing a motor in the vicinity of the rack and pinion gear. The permanent magnet rotating electric machine 401 of the present embodiment is also applicable to those EPS.

  When the driver rotates the steering wheel (handle) 301, the main steering force (rotational force) is transmitted to the rack and pinion gear 307 via the steering shaft 302. Further, the auxiliary steering force (rotational force) output from the permanent magnet rotating electrical machine 401 is transmitted to the steering shaft 302 via the speed reducer 304.

  The rack and pinion gear 307 is a mechanism that converts the input main steering force (rotational force) and auxiliary steering force (rotational force) into a linear reciprocating force and transmits it to the left and right tie rods. It comprises a shaft (all not shown) and a pinion shaft (not shown) on which a pinion gear is formed. The rack gear and the pinion gear mesh with each other in a power converter (not shown), and the rotational force is converted into a linear reciprocating force.

  The steering force converted into the linear reciprocating force in the rack and pinion gear 307 is transmitted to the left and right tie rods connected to the rack shaft, and is transmitted from the left and right tie rods to the left and right wheels. Thereby, the left and right wheels are steered.

  A torque sensor 303 is provided on the steering shaft 302. The torque sensor 303 is for detecting a steering force (rotational torque) applied to the steering wheel 301.

The permanent magnet rotating electrical machine 401 is controlled by the control device 305. The permanent magnet rotating electric machine 401 and the control device 305 constitute an EPS actuator (electrical system).
EPS uses a vehicle-mounted battery 306 as a power source. The control device 305 is an inverter device that converts the DC power supplied from the battery 306 into multiphase AC power so that the output torque of the permanent magnet rotating electrical machine 401 becomes the target torque based on the output of the torque sensor 303. And supplied to the permanent magnet rotating electric machine 401.

  In this embodiment, since the cogging torque is small, the light weight, and the high efficiency concentrated winding permanent magnet rotating electric machine 401 is used for the EPS, a compact EPS with good operability can be provided.

  Next, the electrical connection relationship of the electric actuator (electrical system) used in the EPS of this embodiment will be described with reference to FIG.

  FIG. 13 shows an electrical circuit configuration of an electric actuator (electrical system) used in the EPS of this embodiment.

  The control device 305 includes a power module 416 that constitutes an inverter main circuit (conversion circuit), and a control module 422 that controls an on / off operation (switching operation) of a power semiconductor switching element of the power module 416. The inverter main circuit of the power module 416 includes a three-phase bridge circuit configured by bridge-connecting six power semiconductor switching elements. The battery 306 is electrically connected to the input side (DC side) of the inverter main circuit of the power module 416, and the armature winding 238 of the permanent magnet rotating electrical machine 401 is electrically connected to the output side (AC side). By controlling the switching of each of the six power semiconductor switching elements of the power module 316 by the control module 422, the DC power output from the battery 306 is converted into three-phase AC power in the inverter main circuit of the power module 416, It is supplied to the armature winding 238 of the permanent magnet rotating electrical machine 1.

  The control module 422 forms a control unit that generates a control signal for controlling the on / off operation (switching operation) of the power semiconductor switching element and outputs the control signal to a driver circuit (not shown) of the power module 416. is doing. The control module 416 includes, as input parameters, the detected torque value Tf of the steering wheel 301 detected by the torque sensor 303, the detected rotational speed value of the rotor 250 detected by the encoder E, and converted by the F / V converter 418. ωf and the magnetic pole position detection value θm of the rotor 250 detected by the resolver PS are input.

The torque detection value Tf is input to the torque control circuit 17 together with the torque command value Ts. The torque control circuit 417 calculates a torque target value Te based on the detected torque value Tf and the torque command value Ts, and outputs a current command value Is and a rotation angle θ1 by proportional integration of the calculated torque target value Te. . The rotation angle θ1 is input to the phase shift circuit 423 together with the position information θ output from the encoder E. The phase shift circuit 423 shifts the phase information θ of the rotor 250 in accordance with the command of the rotation angle θ1 and outputs it as the rotation angle θa. The rotation angle θa is input to the sine wave / cosine wave generation circuit 419 together with the magnetic pole position detection value θm. The sine wave / cosine wave generation circuit 419 is a sine wave basic waveform (in which the induced voltage of each phase winding (here, three phases) of the armature winding 238 is phase-shifted based on the rotation angle θa and the magnetic pole position detection value θm. Drive current waveform) A value Iav is generated and output. The phase shift amount may be zero.

The sine wave basic waveform (drive current waveform) value Iav is input to the two-phase / three-phase conversion circuit 420 together with the current command value Is. The two-phase / three-phase conversion circuit 420 outputs current commands Isa, Isb, Isc corresponding to each phase based on the sine wave basic waveform (drive current waveform) value Iav and the current command Is. The control module 422 includes current control systems 421A, 421B, and 421C for each phase. Current control systems 421A, 421B, and 421C for each phase are input with current commands Isa, Isb, Isc for the corresponding phases and current detection values Ifa, Ifb, Ifc for the corresponding phases. The current detection values Ifa, Ifb, Ifc are detected by the current detector CT and are phase currents supplied from the conversion circuit of the power module 416 to the armature winding 238 of each phase. The current control systems 421A, 421B, and 421C for each phase are power semiconductor switching elements for the corresponding phase based on the current commands Isa, Isb, Isc for the corresponding phases and the detected current values Ifa, Ifb, Ifc for the corresponding phases. A control signal for controlling the switching operation is output. The control signal for each phase is input to the driver circuit (not shown) for the corresponding phase of the power module 416.

A driver circuit (not shown) for each phase of the power module 416 outputs a drive signal for switching the power semiconductor switching element of the corresponding phase based on the control signal of the corresponding phase. The drive signal for each phase is input to the power semiconductor switching element for the corresponding phase. When the power semiconductor switching element performs a switching operation, the DC power supplied from the battery 306 is converted into AC power and supplied to the armature winding 238. The permanent magnet rotating electrical machine 401 generates a rotating magnetic field corresponding to the rotational position of the rotor 250, and the rotor 250 rotates.

  The combined current of each phase current supplied to the armature winding 438 is a position that is orthogonal or phase-shifted to the field magnetic flux (the control that advances the combined magnetomotive force of each phase current by 90 degrees or more from the permanent magnet is called field weakening control). ) Always formed. Thereby, it is a commutator-less and can obtain the characteristic equivalent to a DC machine.

  A maximum torque is generated by creating a combined vector of armature magnetomotive force generated by the current flowing through the armature winding 438 by the control device 305 at a position 90 degrees from the center of the permanent magnet, and the phase is shifted as necessary. By doing so, it can be rotated to a high speed.

  By such control, the output (torque) generated by the three-phase sine wave induced voltage and the three-phase sine wave current can be obtained with a constant output with little pulsation regardless of rotation.

  Next, a permanent magnet rotating electric machine used for EPS will be described. The schematic configuration is the same as in FIG. 3, but the configuration of the rotor will be described with reference to FIG.

  The permanent magnet rotating electric machine 401 according to the present embodiment uses an in-vehicle battery (for example, an output voltage of 12 V) as a power source and is disposed in the vicinity of the steering shaft. Therefore, downsizing is required due to the limitation of the mounting position, and a large torque (for example, 4 Nm) output is required because the steering is power-assisted.

The permanent magnet rotating electrical machine 401 is a surface magnet type synchronous motor including a stator 230 and a rotor 250 rotatably supported inside the stator 230. The permanent magnet rotating electrical machine 401 is driven by electric power supplied from a 14-volt power supply (battery having an output voltage of 12 volts). In-vehicle power sources include 24-volt power sources, 42-volt power sources (battery output voltage 36 volts), and 48-volt power sources. For hybrid vehicles, there are 100V, 300V, 600V, etc. The drive power supply voltage of the permanent magnet rotating electric machine 401 varies depending on the type of automobile. The EPS of this embodiment is compatible with any of the above power sources.

  The stator 230 includes a stator core 232 made of a magnetic material in which silicon steel plates are laminated, and an armature winding 438 shown in FIG. 13 held in a slot 234 of the stator core. However, in FIG. 14, the armature winding 438 provided in the slot 234 is wound as shown in FIG. 5, but this description is omitted. The stator core 232 is configured with teeth 236 arranged at equal intervals. An armature winding 438 is wound around each of the plurality of teeth 236. The armature winding 438 may be either a distributed winding method or a concentrated winding method, but is wound in a concentrated winding method in this embodiment.

  When the armature winding 438 is a distributed winding, the field weakening control is excellent, and the generation of reluctance torque is also excellent. As the permanent magnet rotating electrical machine 401, miniaturization of the motor and reduction of winding resistance are very important. By making the armature winding 438 concentrated, the coil end length of the armature winding 5 can be shortened. Thereby, the length of the rotation direction of the permanent magnet rotating electrical machine 401 can be shortened. Further, since the length of the coil end of the armature winding 438 can be shortened, the resistance of the armature winding 438 can be reduced, and the temperature rise of the motor can be suppressed. Further, since the coil resistance can be reduced, the copper loss of the motor can be reduced. Therefore, the ratio consumed by the copper loss in the input energy to the motor can be reduced, and the efficiency of the output torque with respect to the input energy can be improved.

  In addition, the permanent magnet rotating electrical machine 401 may be placed near the steering shaft (column) or may be placed near the rack and pinion. Further, it is necessary to fix the armature winding with a miniaturized structure, and it is also important that the winding work is easy. Concentrated winding is easier to wind and fix the winding than distributed winding.

  The armature winding 238 is composed of three phases of U phase, V phase, and W phase, each composed of a plurality of unit coils. The plurality of unit coils are connected by a connection ring 411 shown in FIG. 21 formed from a plate-like conductor for each of the three phases in the coil end portion.

  The permanent magnet rotating electric machine 401 is required to have a large torque. For example, when the steering wheel (handle) is rapidly rotated in a driving stop state or a driving state close to the stop of driving, a large torque is required for the motor due to frictional resistance between the steering wheel and the ground. At this time, a large current is supplied to the stator coil. This current varies depending on conditions, but a current of 100 amperes or more flows. In order to supply such a large current safely and to reduce heat generation due to the current, it is very important to use a connection ring 411 formed from a plate-like conductor. By supplying current to the armature winding 438 via the connection ring 411, the connection resistance can be reduced, and the voltage drop due to copper loss can be suppressed. This facilitates the supply of a large current. Further, there is an effect that the rising time constant of the current accompanying the operation of the inverter element is reduced.

The rotor 250 includes a rotor core 252 made of a magnetic material in which silicon steel plates are laminated, and a permanent magnet 254 that is a plurality of permanent magnets fixed to the surface of the rotor core 252 with an adhesive. Permanent magnets 254 and 256 are magnets bound by the SiO ₂ described above. The rotor core is fixed to the shaft 218. In order to prevent the permanent magnets 254 and 256 from scattering, a magnet cover may be provided or a tape may be wound around the entire outer circumference (stator side) of the permanent magnets 254 and 256. .

As shown in FIG. 21, the stator core 232 is supported and fixed so as to be sandwiched between cup-shaped brackets 409 from both sides in the axial direction. A bearing 216 is provided on the bracket 409. The bearing 216 rotatably supports the shaft 218. On the shaft 218, a resolver PS for detecting the position of the rotor 250 and an encoder E are provided.

  Power is supplied from an external battery to the U phase, V phase, and W phase connected by the connection ring 411 via a power cable.

  In the embodiment shown in FIG. 14, the rotor 250 is a so-called 10-pole 12-slot motor having 10 magnets that form a 5-pole pair of N and S, and the stator 230 has 12 slots 234. This motor has a periodicity of 60 cogging torques, which is the least common multiple of the number of poles P and the number of slots N, and has a smaller cogging torque than a concentrated winding motor obtained by repeating two poles and three slots.

  However, in EPS applications, it is desirable to further reduce the cogging torque because the person holding the handle feels even with a very small cogging torque.

  In order to reduce the torque pulsation, it is desirable to skew the field pole, that is, the magnet arrangement in the circumferential direction. A specific structure is shown in FIG. Only the magnet may be skewed, but considering the ease of manufacture, the rotor iron core and magnet holding the magnet are first integrated, and the rotor iron core and magnet integrated body, hereinafter referred to as the core, are in the circumferential direction. A structure that is fixed so as to be skewed is preferable. In the upper figure, the rotor is divided into two cores, and the divided cores are shifted in the circumferential direction by an electrical angle θ. In the case of a three-phase motor, the electrical angle θ is generally 30 ° or 15 °.

  Another embodiment is shown in FIG. In this embodiment, the rotor is divided into three cores, and the second core is skewed by an angle θ with respect to the first and third cores. The ratio of the axial lengths of the divided first to third cores is a: b: c = 1: 2: 1. As a result, in the case of FIG. 15, a force acts in the axial direction during rotation, but in the case of FIG. 16, it becomes an internal force and no force acts in the axial direction. This is effective in reducing noise.

  In the second embodiment, in order to reduce the cogging torque, the rotor may be divided and skewed, that is, shifted in the circumferential direction. FIG. 17 shows the state of cogging torque, the horizontal axis is the rotation angle expressed in electrical angle, the vertical axis shows the magnitude of the torque, and each graph shows the fluctuation part of the torque. For example, if the cogging torque having an electrical angle of 60 ° is divided into two in the axial direction when there is a skew and the electrical angle is shifted by 30 ° in the circumferential direction, the pulsation having an electrical angle of 60 ° can be reduced. it can. However, a cogging torque with an electrical angle of 30 ° remains. Similarly, if the rotor is divided into two parts and shifted from each other by an electrical angle of 15 °, the cogging component having an electrical angle of 30 ° disappears, but the cogging component having a 60 ° period remains. This is effective when the order component included in the waveform of the cogging torque is one and there are no or few other order components.

In yet another method of the present embodiment, the rotor is ideally skewed as a method for solving the cogging torque that cannot be reduced by division. The shape of the magnet is a helical shape shifted so as to be continuously inclined in the circumferential direction with respect to the rotation axis direction of the rotor. The magnet shape is shown in FIG. FIG. 19 shows the principle. FIG. 19 shows a view of a rotor having two poles, that is, a pair of poles developed on a plane. The magnet is configured to be shifted from the end of the shaft to the end by 60 ° in the case of a three-phase motor. When this shape is rounded into a cylindrical shape, the magnet has the helical shape of FIG. Since the point A portion and the point B portion are shifted by 30 °, the torque ripple is canceled with the same effect as the points A and B are relatively skewed by 30 °. Further, since the points A and C are deviated by 15 °, the same effect as the 15 ° skew described above is obtained. In this way, there is a pair of points that cancel out torque pulsation on all axes, so even in higher order, cogging torque due to all harmonics can be eliminated by the same principle, and torque pulsation is reduced. be able to. Electrically, torque pulsations with a period of 60 ° or less can theoretically be all zero. Although the magnet shape of FIG. 18 and the magnet shape of FIG. 19 are different, since the cogging torque can be reduced by skewing the field pole, the cogging reduction effect can be obtained even if the magnet shapes are different.

In a conventional sintered magnet, such a complicated shape is manufactured by post-processing after sintering, and thus it is expensive and cannot be employed in an automobile motor that requires low cost. However, it is relatively easy to form this shape with a press. Since the motor of the present embodiment uses a magnet bound by SiO ₂ , the shape of the press is almost the final shape as it is. For this reason, the cutting process of the magnet after being bound with the binding agent becomes unnecessary or simplified. By using the magnet having the above shape, it is possible to realize a motor in which high-order cogging torque is reduced to a very low value.

  FIG. 20 shows a magnet having a more complicated shape than FIG. In FIG. 19, the magnet shape is a kamaboko shape, whereas FIG. 19 is a block shape and the specific shape is different, but the cogging is reduced by skewing the magnetic poles. The magnet shown in FIG. 20 has a shape that is substantially V-shaped in the direction of the rotation axis. A rotating electrical machine that uses this magnet has a shaft that generates a permanent magnet with respect to a rotating magnetic field generated by a stator. Since the force component in the direction is reversed in one side and the other in the V shape and cancels each other, no force is received in the axial direction. For this reason, there is an advantage that noise reduction and configuration are simplified. This magnet may be divided into two parts in the axial direction, and the same magnets may be arranged opposite each other. Here, the V-shape of the magnet means that the magnet is gradually skewed in the circumferential direction of the rotor, which is the rotation direction, when viewed from the axis along the rotation axis of the rotor, and the skew direction is reversed and rotated in the middle of the magnet. The shape is opposite to the circumferential direction of the child, and the magnet gradually skews in the opposite direction. By setting the position where the skew direction is reversed near the center in the rotation axis direction of the magnet, the forces generated in the rotation axis direction can be canceled each other. As described above, the same effect can be obtained even if the magnet is divided at the turn-back point of the skew.

  Even if the cogging torque is solved by such a method, a further problem appears in the electric power steering motor. That is torque pulsation due to manufacturing errors. In general, the harmonic component is lower than the power supply frequency and has second, fourth, sixth, eighth, tenth, and twelfth orders with respect to the rotational speed. In the above-described motor, since 10 poles are used as an example, the effect of reducing torque pulsation due to skew is 30th or higher with respect to the rotational speed. Lower-order pulsations are caused by manufacturing errors.

  In addition, due to manufacturing errors such as the gap between the salient pole magnetic core 42 and the stator yoke 41, or the length of the salient pole magnetic poles, the core circularity of the stator inner diameter deteriorates and cogging torque and pulsation torque are generated. To do. Since the cogging torque and pulsation torque are different from general pulsation torque, the magnitude and phase are different for each motor, so that prevention is very difficult.

  For example, when one of the segment-like permanent magnets 256 becomes thick as indicated by S3, for example, the rotor 250 has a cogging torque corresponding to the number 12 of salient pole magnetic cores 42 per rotation. appear. This is a much larger value than the cogging torque of 60 cycles / rotation caused by the number of poles of the permanent magnet and the salient pole magnetic core 42 described above. Among the in-vehicle actuator devices, particularly in the electric power steering device, the pulsation is transmitted to the driver via the handle.

  As described above, in order to suppress the cogging torque that is so small that pulsation is transmitted to the driver, it is very difficult to deal with the imbalance caused by assembly and processing on a component basis with high accuracy, and the manufacturing cost increases. There was a problem.

Therefore, a magnetic imbalance of the rotor having a weight that generates a cogging torque opposite in phase to the cogging torque due to a manufacturing error can be created by cutting the rotor magnet. This makes use of the characteristics of the magnet in which magnetic powder is bound by the above-mentioned SiO ₂ , that is, the workability of processing only that part without breaking the peripheral part of the magnet during the cutting work. This is possible because of goodness. In the conventional bonded magnet, the peripheral portion is broken by post-processing. On the other hand, there is a problem such as cracking of the sintered magnet, and the magnet itself cannot be processed after the rotor is manufactured.

  In this way, since cogging torque generated by manufacturing can be compensated by post-processing, a motor in which cogging torque due to manufacturing error becomes a problem, such as EPS, can be provided at low cost.

  In this correction, the magnetic unbalance amount is measured after the stator 230 is assembled, and the corresponding magnetic unbalance amount can be removed by, for example, cutting.

  Next, the magnetic imbalance correction apparatus of this embodiment will be described with reference to FIG.

The permanent magnet rotating electric machine 401 is driven at a constant speed at a low speed. A torque detector 413 outputs a measured value of cogging torque. Further, the resolver PS and encoder E for detecting the rotation position can output the phase together with the magnitude of the cogging torque. 414 is a magnetic unbalance amount calculation device, and the phase and size of the 442a groove on the surface of the salient pole magnetic core 442 that corrects it based on the measurement result of the cogging torque from the permanent magnet rotating electrical machine 401, or the permanent magnet 254 This is a device for calculating the amount of magnetic unbalance correction by calculating the phase and size of the groove 406a on the 256 surface from the shape of the stator and rotor and the characteristics of the permanent magnet. In a motor having a large cogging torque, the cogging torque can be reduced by providing the rotor 250 with a groove 406a corresponding to magnetic imbalance. By performing the total number of motors, for example, it is possible to perform the cogging torque correction in the same manner as taking all the rotational balances, thereby providing a motor with a small cogging torque. Moreover, it is also possible to correct only a motor having a large cogging torque as necessary.

  As described above, in the present embodiment, the method of correcting by providing a groove on the gap surface between the stator 230 and the rotor 250 has been described, but it is also possible to attach a magnetic material to a groove provided in advance. Needless to say. Further, correction can also be made by adding and removing the magnetic material to and from the air gap surface and its periphery, or adding and removing the magnetic material by other methods. Further, if necessary, the magnetic field calculation is used to calculate the stator magnetic correction amount and the rotor magnetic correction amount that make the cogging torque detected by the torque sensor 413 zero, and the accuracy can be further improved.

  In this embodiment, the number of salient poles is 12 in the concentrated winding stator and the number of poles of the rotor 250 is 10. That is, the ratio between the number of salient poles M and the number of poles P of the rotor is M: P = 6n: 6n ± 2 (where n is a positive integer) has been described as a permanent magnet rotating electrical machine. However, the present invention is not limited to this, and the number of salient poles M and the number of poles P of the rotor 250 It is also applicable to a permanent magnet rotating electrical machine in which the ratio of M: P = 3n: 3n ± 1 (n is a positive integer). For example, the number of poles of the permanent magnet can be set to 8, and the number of salient poles of the stator can be set to 9.

  Similar cogging torque correction can also be performed by selecting the so-called 3: 2 magnetic poles where the number of salient poles is 12 and the number of salient poles is 8, depending on the position of the groove on the surface of the salient pole pole. In this case, the cogging torque can be minimized by disposing a groove of an appropriate size not at the center of the salient pole magnetic pole surface but at a specific position of the salient pole magnetic pole where the cogging torque can be reduced.

Next, operational effects of the second embodiment will be described below. In the second embodiment shown in FIGS. 12 to 21, the magnet used for the rotating electrical machine has the structure described above, that is, the powder magnet material and the binder precursor with good wettability are used as the magnet. Producing magnets by impregnation has at least one or more of the following effects. As described above, SiO ₂ is most suitable as a binder for the powder magnetic material and the precursor having good wettability.

  Effect 1 In the above-described magnet manufacturing process, there is no sintering process heated to a high temperature, so that the magnet can be manufactured easily. Even if the temperature is raised in order to improve the magnetic properties after binding with the binder, the temperature is lower than 1000 ° C. and lower than the sintering temperature of the magnet material, and the influence of strain is smaller than that of the sintered magnet. Therefore, the manufacturing cost can be reduced compared with the sintered magnet.

  Since it is not the magnet which uses the epoxy resin called the effect 2 and a common bond magnet, the energy density of a magnet is large, and the rotary electric machine of a comparatively favorable characteristic can be obtained cheaply.

  Effect 3, after the magnet is molded with the magnet material, the binder can be cured at a relatively low temperature, and the shape and size of the molded magnet material are less changed. Since it can be manufactured with high accuracy with respect to the shape and dimensions of the magnet, high characteristics can be obtained as a motor or a generator. For example, the magnetic flux density of the gap can be reduced by reducing the cogging torque due to dimensional errors, or by the shape of a complex magnet such as a helical skew where the magnet is arranged so as to be displaced in the circumferential direction relative to the direction parallel to the rotation axis of the rotor Can be reduced. Even with a magnet material alone, the cutting after binding with a binder is very little and easy. For example, it is not a substantial magnet-shaped forming process, such as cutting the protruding portion of the adhesive, so that the process is easy. Since the conventional sintered magnet is heated to a high temperature for sintering, it shrinks in the process of lowering the temperature thereafter, and the shape of the magnet material changes. Therefore, in the conventional sintered magnet, it has been necessary to spend a lot of time for cutting for adjusting the shape and dimensions of the magnet after the sintering process. In the above-described embodiment, a necessary magnet shape can be obtained with extremely few cutting processes and, in some cases, without a cutting process.

  Effect 4, as described above, since the molding shape of the magnet material hardly changes in the subsequent binder impregnation or curing process, the magnet is manufactured while maintaining the curved shape of the magnet material by pressing or the like with high accuracy. It is possible. Theoretically, even if the skew is known as the preferred magnet shape, it is possible to realize a helical magnet that was difficult to commercialize because there is no method for mass production, and it is possible to obtain a rotating electrical machine with good characteristics It is. More complicated shapes than those shown in FIGS. 18 and 20 are possible.

  Effect 5, sintered rare earth magnets have low electrical resistance and large loss and heat generation due to eddy currents. Since the magnet binds rare earth magnetic powder with a SiO-based binder that is an electrical insulator, the electrical resistance inside the permanent magnet is large and eddy currents are reduced, thereby reducing eddy current loss and heat generation. In addition, the binder precursor described above has good wettability and can produce a permanent magnet having a very high internal resistance with respect to rare earth magnetic powder provided with an electrical insulating film. For this reason, eddy current loss and heat generation inside the magnet can be greatly reduced. A rotating electrical machine for automobiles, particularly a rotating electrical machine used in a hybrid vehicle, may be used in an environment exceeding 100 degrees, and it is necessary to suppress heat generation due to eddy current in the magnet. In the above-described embodiment, since the electric resistance can be increased, the heat generation of the magnet can be reduced. Further, the loss of the rotating electrical machine can be reduced correspondingly, and the efficiency is improved.

  Effect 6: The sintered rare earth magnet is coated after cutting to prevent corrosion. Incorporating this into the rotor is a conventional method. For this reason, it could not be processed after being incorporated into the rotor. Furthermore, bond magnets could not be processed after rotor molding. In the rotating machine using the magnet according to the present invention, the cogging torque is measured after the rotor is assembled and further magnetized, taking advantage of the good post-processing property of the magnet, and the magnetic pole imbalance is detected therefrom, and the cutting is performed accordingly. Processing.

  The harmonic components of the magnetomotive force produced by these stator windings are shown in FIGS. The horizontal axis of the bar graph indicates the order of the spatial magnetomotive force in the circumferential direction per pole pair as the first order, the black bar indicates the synchronous order, and the hatched bar indicates the asynchronous order. FIG. 22 is a so-called distributed winding, in which (A) shows the harmonic component of the magnetomotive force produced by the stator of the 2-pole 6-slot motor, and (B) shows the stator of the 2-pole 12-slot motor. The harmonic component of the magnetomotive force to be created is shown. As can be seen from the figure, the asynchronous component has only a spatial fifth or higher order. The 2-pole 12-slot motor has less spatial harmonics. This harmonic causes the eddy current of the magnet.

  On the other hand, FIG. 23 shows concentrated winding, where (A) shows the harmonic component of the magnetomotive force produced by the stator of the 8-pole 9-slot motor, and (B) shows the stator of the 10-pole 9-slot motor. The harmonic component of the magnetomotive force to be created is shown. Thus, concentrated winding has a larger asynchronous component of magnetomotive force than distributed winding. In particular, in the case of 8 poles and 9 slots, the 5 / 4th order component is large, and in the case of 10 poles and 9 slots, the 4 / 5th order component is large. Torque is generated in the motor only when the number of magnetic poles of the rotor matches the spatial order of the stator magnetomotive force. Therefore, in the case of a 10-pole 9-slot motor, the component does not synchronize with the rotor even though there is a fixed magnetic force that can rotate the 8-pole motor. Causes eddy currents. This causes demagnetization due to the temperature rise of the magnet.

  Similarly, FIG. 24 shows concentrated winding, and shows the harmonic component of the magnetomotive force produced by the stator of the 2-pole 3-slot series motor. FIG. 24B shows the magnetomotive force produced by the stator of the 4-pole 3-slot series motor. The harmonic component of is shown. This corresponds to the embodiment of FIG. It can be seen that the 2-pole 3-slot motor does not have asynchronous harmonics lower than the primary, but still has more harmonics than the distributed winding. Conversely, a 4-pole 3-slot series motor has a large low-order component of 1/2 order.

  Similarly, FIG. 25 shows a harmonic component of a magnetomotive force generated by a 10-pole 12-slot motor stator, and FIG. 25B shows a magnetomotive force generated by a 14-pole 2-slot motor stator. The harmonic component of is shown. This corresponds to the motor of FIG. In this case also, it can be seen that there is an asynchronous large harmonic component.

  Of the above, it should be particularly noted that the asynchronous component increases as the number of poles> the number of slots. When the stator is to form a pole, it means that the higher the number of coils, the lower the harmonics. Therefore, since the concentrated winding motor has a small number of slots, it has a large eddy current, and it can be said that the eddy current of the magnet tends to flow particularly in the combination of the number of poles> slot number.

  FIG. 27 is a schematic drawing of rare earth magnetic powder. The magnetic powder 502 has a flat shape having a first surface 504 having a large area and a second surface 506 having a smaller area than the first surface. is doing. Since the second surface 506 is very thin, the second surface 506 is often nearly perpendicular to the first surface. In this figure, since the magnetic powder 502 is schematically drawn, a flat rectangle is formed. However, the shape and size are not constant, but are not a rectangle but are flat.

  FIG. 27 is a diagram schematically showing the arrangement of the magnetic powder 502 when the magnetic powder 502 is compression molded. In order to simplify the explanation, the magnetic powder 502 is a flat rectangle having a first surface 504 having a large area and a second surface 506 having a smaller area than the first surface. As shown in the figure, it is very flat but has various shapes. When the magnetic powder is compressed along the Z-axis shown in FIG. 27, many magnetic powders are arranged so that the first surfaces 504 face each other, that is, the first surface is substantially along the surface composed of the axes X and Y. It is laminated so that The first surface 504 having a large area shown in FIG. 27 is magnetized along the surface composed of the axis X and the axis Y with respect to the laminated magnet composed of the surface composed of the axis X and the axis Y. In comparison with the case of magnetization along the Z axis, the magnetic properties such as residual magnetic flux density and coercive force are greater when magnetized along the plane consisting of the axes X and Y than when magnetized along the Z axis. It is good.

  FIG. 28 shows the kamaboko type permanent magnet 254 described with reference to FIGS. 5 and 14. The permanent magnet 254 or 256 has the opposite magnetization direction but the same shape and the same amount of generated magnetic flux. The permanent magnet 254 will be described below as a representative example. A surface 276 facing the stator in the radial direction of the rotor has a curved surface shape having a higher rate than the rotor core. Further, both sides in the circumferential direction of the permanent magnet 254 are directed substantially in the radial direction, but may be slightly inclined in a direction in which the stator side is slightly narrower with respect to the radial direction so that it can be easily removed from the mold when compression molding is performed. .

  When the rare earth magnetic powder is compressed and compressed in the direction of the rotation axis of the rotor, the magnetic characteristics of the permanent magnet are improved. In FIG. 27, when the Z-axis for compressing the magnet powder 502 is in the direction of the rotation axis of the rotor, most of the magnetic powder 502 is laminated so that the first surface 504 having a large area becomes a surface perpendicular to the rotation axis. The This is almost the same direction as the lamination direction of the steel plates of the laminated rotor cores. The laminated magnet in this direction is magnetized on the surfaces of the axes X and Y in FIG. Therefore, a magnet having good magnetic characteristics as described above is obtained, which is preferable from the viewpoint of the characteristics of the rotating electrical machine.

  In order to facilitate compression molding from the viewpoint of improving productivity, compression from the radial direction of the rotor in FIG. 28 is preferable. The compression of the rotor in the radial direction is a direction in which the magnetic powder to be compressed is thin. Rare earth magnetic powder is very hard compared to iron or the like, and the density of the compressed magnetic powder increases as the width of the magnetic powder in the compression direction is thinner. The density of the magnetic powder in the compressed state has a great influence on the magnetic flux density of the permanent magnet. When the density of the magnetic powder is low, the magnetic characteristics of the permanent magnet are deteriorated. Moreover, when the magnet shape has a curved surface and accuracy with respect to the shape from the characteristic surface becomes a problem, it is easier to obtain a preferable result by compressing from the smaller width of the magnetic powder in the compression direction. Therefore, in some cases, it is better to perform compression molding from the radial direction for the kamaboko type magnet.

  FIG. 29 is a view showing a state in which the kamaboko type permanent magnet 254 is attached to the rotor core 252 in a cross section perpendicular to the rotation axis. The rotor core 252 has a recess 282 formed on the surface thereof, and the core side portion of the permanent magnet 254 is fixed inside the recess 282 by an adhesive layer 284. As shown in FIG. 28, the permanent magnets 254 and 256 are the same except for the magnetization direction and the mounting structure is the same, so the permanent magnet 254 is described as a representative example. The shape of the kamaboko shape is as described in FIG. 28, and the same reference numerals indicate the same as other figures including FIG. This kamaboko type permanent magnet may be manufactured by compression molding in the rotation axis direction in FIG. 28 or may be manufactured by compression molding in the radial direction of the rotor. An array of magnetic powders in the magnet interior 286 when molded by radial compression is shown enlarged at 278. The first surface having a large area faces a surface substantially perpendicular to the radial direction of the rotor, that is, the stator core. As described above, this magnetic powder is magnetized almost perpendicularly to the first surface having a large area, so that the magnetization characteristics with respect to the arrangement of the magnetic powder are deteriorated, but the magnetic powder in the compression direction is reduced in thickness. And has the advantage of easily increasing the compression density of the magnetic powder. Increasing the compression density of the magnetic powder leads to improved magnetic properties.

  FIG. 30 is an explanatory diagram of a method for manufacturing the cylindrical magnet 712. It is possible to make the above-described rotating electric machine as shown in FIG. 3 by fitting a cylindrical magnet 712 on the outer periphery of the rotor 250 and magnetizing the magnet so that the magnetization direction is reversed at the magnetic pole position. A relatively small rotating electrical machine uses this cylindrical magnet 712 to improve productivity.

  A magnet is formed by filling rare earth magnetic powder between the outer mold 702 and the inner mold 704 to be compression-molded, compression-molding in the direction of the rotation axis, and then impregnating the above-mentioned binder precursor. This magnet is fixed to the outer periphery of the rotor core 252 and magnetized to complete the rotor. In this case, in many of the magnetic powder arrangements, the first surface with a large area is arranged in a direction perpendicular to the rotation axis, so the magnetization direction is a direction along the first surface with a large area, and the magnetic powder arrangement Excellent magnetic properties are obtained when viewed in the direction.

  In FIG. 30, the magnet has a simple cylindrical shape for ease of explanation, but it is desirable that the side surface of the magnet stator be curved in order to reduce torque pulsation including cogging. In conventional sintered magnets, due to the change in the shape of the magnet due to the sintering temperature, it has been difficult to make the outer shape of a curve from the viewpoint of manufacturing technology, but the manufacturing method described above is relatively easy. Can be manufactured.

  FIG. 31 shows a state where a rotor using a cylindrical magnet 712 having a curved stator side surface is sectioned along a plane perpendicular to the rotation axis. A rotor 250 is fixed to the shaft 218, and a cylindrical magnet 712 is provided on the outer periphery of the rotor 250. The stator side of the cylindrical magnet 712 is a curve with a high polarity, and this curve is such that the internal induced voltage of the rotating electrical machine approaches a sine wave. Since such a cylindrical magnet can be made by compression molding in the direction along the rotation axis as shown in FIG. 30, the productivity can be greatly improved as compared with the sintered mold. Further, most of the magnetic component has a first surface perpendicular to the axis, and excellent magnetic properties can be obtained. Further, it coincides with the laminated surface of the rotor, which is also magnetically preferable. Eddy currents are difficult to flow.

  The magnets and rotating electrical machines described in FIGS. 30 and 31 are suitable for relatively small rotating electrical machines. Not only for automobiles but also for rotating electrical machines used in other fields, the effect is great. Although all the embodiments of the above description including FIG. 30 and FIG. 31 have been described for automobiles, it can be used for rotating electrical machines in fields other than automobiles, and the effects described for automobiles can be applied to other fields. The same applies to rotating electrical machines. Since the use environment for automobiles is harsh, the effect is particularly prominent. However, rotating electric machines in other fields are more effective than conventional rotating electric machines, and can of course be used.

The present invention is characterized in that since the rotor is constituted by magnets bound by SiO ₂ , eddy currents of the magnets hardly flow. Since each magnetic powder of the magnet is electrically bound by SiO ₂ which is an insulator, the electric resistance inside the magnet is increased. Rare earth magnetic powder is very hard compared to pure iron and the like, and even when pressed, gaps are easily formed between laminated magnetic powders. The precursor of SiO ₂ has very good wettability to the rare earth magnetic powder and penetrates into the gaps between the magnetic powders to bind the magnetic powders to each other. For this reason, a magnet having high magnet strength and high internal electrical resistance can be obtained. Such magnets are unlikely to generate eddy currents. The rotating electric machine for automobiles has a small volume of the rotating machine with respect to electric power used for rotating electric machines in other fields. That is, the amount of power per volume is large. A vehicular rotating electrical machine used in such a severe environment has a large effect of reducing eddy currents. In addition, eddy current is more likely to occur in concentrated winding than in distributed winding. Therefore, the magnet is effective for concentrated winding motors.

  While the embodiments of the present invention have been described above, the following effects can be obtained by using these embodiments.

  According to each embodiment of the present invention, the permanent magnet provided in the rotating electrical machine is manufactured as follows. First, the magnetic material is compression-molded, and the compression-molded magnetic material is impregnated with this material and a binder precursor having excellent wettability to obtain a magnet in which the magnetic material is bound with the binder. By using such a magnet for a rotating electrical machine, a rotating electrical machine with higher performance can be obtained than a rotating electrical machine using a magnet using an epoxy resin as a binder. Thus, the magnet weight ratio of the formed magnet can be increased by compressing the magnet powder without mixing an insulating material such as epoxy. Therefore, a magnet with a high energy density can be obtained, and the output of the motor can be increased. In addition, in the manufacture of the permanent magnet, in addition to the step of binding the magnetic material with the binder, a step of further magnetizing is necessary. This magnetizing step may be performed after a magnet material formed by binding a magnetic material with a binder (described as a magnet) is incorporated into a rotating electrical machine part. Rather, it is often easy to manufacture a rotating electrical machine by fixing it to a component such as a rotor of a rotating electrical machine without being magnetized and then magnetizing it. The magnet functions as a permanent magnet by being magnetized in the magnetizing step.

  Further, according to each embodiment of the present invention, the precursor is a binder having good wettability with the magnet material, and the permanent magnet bound with the magnet material is used for the permanent magnet rotating electric machine. In the present invention, a magnetic material and a binder with good wettability can be used to increase the proportion of the magnetic material in the magnet, reducing the decrease in magnetic energy of the magnet compared to the case where an epoxy resin is used as the binder. And good characteristics can be maintained.

Further, according to each embodiment of the present invention, the magnet has a binder which is an insulator between the magnet materials, and the magnets of each part are insulated, so that the three-dimensional As a typical solid magnet, the electrical resistivity is high and the eddy current loss is small. As a result, it is possible to obtain a rotating electric machine that is highly efficient and can handle high-speed rotation. Specifically, the SiO ₂ precursor is thinly impregnated as a binder with good wettability into the magnet powder, and since SiO ₂ is an insulator, each magnet powder is in a state of having a thin insulating coating. As a result, the electrical resistivity of the magnet is increased and eddy current is less likely to flow. By sticking this magnet on the rotor surface, the temperature of the magnet can be suppressed during high-speed rotation, and a motor with resistance against demagnetization can be realized. In particular, in the surface magnet type rotating electrical machine as in this embodiment, since the eddy current loss tends to flow in the magnet on the gap surface, the magnet may generate heat, but the magnet of the rotating machine in this embodiment has an electric resistance. Since it is large, eddy currents can be reduced and such problems can be solved.

In addition, according to each embodiment of the present invention, by using a rare earth magnet material having excellent magnetic properties as a magnet material, a magnet having excellent magnetic properties can be manufactured, and a rotating electrical machine having good properties can be obtained. . For example, SiO ₂ can be used as a binder that has good wettability with a rare earth magnet material as a precursor, and a rare magnet material is bound with SiO ₂ to produce a permanent magnet that suppresses deterioration of magnetic properties. It is possible to obtain a rotating electrical machine with good characteristics by using this magnet for a rotor.

  Further, according to each embodiment of the present invention, since the permanent magnet can be manufactured at a relatively low temperature, the magnet material can be bound in a state in which the shape and dimensions of the magnet material by press molding are maintained with high accuracy. it can. As a result, it becomes easy to produce magnets with high accuracy. For this reason, the magnet after being hardened with a binder is much easier to form than a sintered magnet, and the final shape of the magnet is often obtained with a slight amount of cutting work. The magnet can be completed. In addition, since the magnets with complicated shapes have almost no heat shrinkage, it is possible to achieve the dimensional accuracy of the magnet with the accuracy of the mold, and to obtain a high-precision rotating electric machine without uneven rotation using a magnet with high dimensional accuracy. Can do. This makes it possible to easily construct a rotor using a particularly complex and continuous three-dimensional magnet having a curved shape that could not be achieved with a conventional sintered magnet, for example, a helical skew magnet. It is possible to make a motor with good controllability.

  Moreover, according to each Example of this invention, since the workability of a permanent magnet is good and only a part can be processed, there exists the characteristic that it is easy to cut after a final shape. For this reason, after attaching a magnet and assembling and magnetizing a rotor, it cuts in order to balance each magnetic pole. By cutting a magnet having a strong magnetic pole energy in this way, it is possible to suppress variations in the energy of the rotor magnetic pole and reduce the cogging torque resulting therefrom. This cutting process makes use of the feature that the magnet material can be post-processed. In conventional sintered magnets, when processed after the assembly of the rotor, problems of cracking and corrosion due to oxidation occurred, and this could not be done in practice. Thereby, torque pulsation can be reduced and a rotating machine with good controllability can be obtained.

  Next, other embodiments relating to permanent magnets applicable to each of the above examples will be listed below.

In the permanent magnet of the above embodiment, the magnetic powder is bound by the binder, but when used in a rotating electrical machine, the size of the particles of the magnetic powder may be changed depending on the location. Here, the larger the magnetic powder particle size, the better the magnetic properties. For example, collecting large magnetic powder at the corners and surface of permanent magnets with severe demagnetization improves reliability. can do. Note that the technique of changing the size of the magnetic powder particles depending on the location does not need to be made of SiO _{2 as the} binder, and can be applied to a conventional bonded magnet. In addition, it is not necessary to perform compression molding at once to change the size of magnetic powder particles. For example, magnets having different particle sizes are separately molded, and finally these magnets are integrated. It doesn't matter.

Furthermore, it is conceivable to arrange a magnetic powder having a high coercive force on the side facing the stator and a magnetic powder having a high residual magnetic flux density on the side away from the stator. By configuring the permanent magnet in this way, the magnetic powder with a high residual magnetic flux density has less rare earth content than the magnetic powder with a high coercivity, and the magnetic flux density is higher than that formed with a magnetic powder with a high coercivity. Therefore, high torque and low cost can be achieved. In particular, different magnetic powders may be arranged in layers. In addition, as a molding method of this permanent magnet, after each magnetic powder is separately or simultaneously compression molded in the same mold,
It is conceivable to impregnate a precursor of SiO ₂ .

  In the above embodiment, a permanent magnet is attached to the surface of the rotor core, or a magnet insertion hole is formed in the rotor core, and the permanent magnet is inserted into the magnet insertion hole. Since the permanent magnet of the example can be easily formed into a cylindrical shape, the permanent magnet may be formed into a cylindrical shape, and the cylindrical permanent magnet may be disposed and fixed outside the rotor core. Such a cylindrical permanent magnet is easy to manufacture because it only needs to be inserted into the rotor core from the axial direction, and the permanent magnet is separated from the rotor core by centrifugal force unless the permanent magnet is damaged. There is no end to it. Further, if the permanent magnet of the above embodiment is used, the inner and outer diameters of the cylindrical shape can be formed with high accuracy, so that the outer periphery and the permanent of the rotor core can be made permanent without cutting after mold forming. The gap between the inner periphery of the magnet can be made as small as possible, and the gap between the stator and the outer periphery of the permanent magnet can be improved with high accuracy.

  Moreover, if the permanent magnet of the said Example is used, it will become possible to manufacture the permanent magnet provided with both the anisotropy and isotropic property in one permanent magnet. When used in a rotating electrical machine, it is better to make the side close to the adjacent poles anisotropic and to make it isotropic, and with this configuration, magnetization can be performed satisfactorily.

  Further, the general magnetic powder has a flat plate shape, but the permanent magnet of the above embodiment is compression-molded before impregnating the binder, so that the magnetic powder as shown in FIG. The direction in which the body is flattened is almost in the same direction. Here, when used in a rotating electrical machine, if the flat surface is directed to the stator side, superior magnetic characteristics can be obtained than the non-flat surface is directed to the stator side. . Also, magnetization can be performed well by matching the direction of the flat surface of the magnetic powder with the direction of magnetization. Further, since the direction compressed from the direction of the flat surface has a stronger strength than the direction compressed from the direction of the non-flat surface, it may be configured so that the flat surface faces in the direction in which the stress acts. . For example, it may be configured such that a flat surface faces in the direction in which the centrifugal force acts.

  Further, in the first embodiment, the description has been made as an equivalent rotating electric machine. However, the first rotating electric machine is a low-speed and high-torque rotating electric machine, and the second rotating electric machine is a high-speed and low-torque rotating electric machine. Thus, the first rotating electrical machine may mainly be driven mainly, and the second rotating electrical machine may be mainly performed to generate power. At this time, since the first rotating electrical machine is small and requires high torque characteristics, a sintered magnet having a high magnetic flux density may be used as the magnetic pole of the rotor. On the other hand, the second rotating electrical machine does not require much torque, but it is desired to reduce the iron loss when the second rotating electrical machine is rotated at high speed. Here, when a sintered magnet having a high magnetic flux density is used as the magnetic pole of the rotor in the second rotating electrical machine, the iron loss is proportional to the square of the magnetic flux density of the permanent magnet when rotated at high speed. Because it grows, it is not very effective. Therefore, a permanent magnet formed by binding magnetic powder with a SiO-based material as used in the above embodiment as the magnetic pole of the rotor in the second rotating electrical machine is used, and the utilization rate of the reluctance torque is set to the first. By making it larger than the rotating electric machine, the overall efficiency of the vehicle can be improved.

In the above embodiment, SiO ₂ is used as a binder for the magnetic powder, but it is also conceivable to use SiO ₂ as an insulator. Specifically, SiO ₂ may be interposed between the steel plates of the laminated steel plates used for the rotor core and the stator core. In this case, one does not need to be integrated with an adhesive is applied to one of the laminated steel, a lower SiO ₂ precursor viscosity by dipping the precursor of SiO ₂ in a state of being laminated laminated steel sheet The steel sheets can be brought into contact with each other and bonded together.

Further, as a method of using the SiO ₂ precursor in another application, it is conceivable to form an insulating layer on the surface of the coil by applying the SiO ₂ precursor to the coil. Since the precursor of SiO ₂ has a low viscosity, it is possible to form an insulating layer on each of the coils wound in a bundle. Thus, by applying the precursor of SiO ₂ , it is possible to perform a surface treatment with a high hardness having an insulating function in any narrow area.

  Next, inventions other than those described in the claims that can be grasped from each of the above embodiments will be described below together with the effects thereof.

  (1) A permanent magnet type rotating electrical machine in which a rotor rotates relative to a stator, wherein the stator includes a stator core having a plurality of slots in a circumferential direction, and the slots in the stator core. The rotor has a permanent magnet that is magnetized so that different magnetic poles are formed in the circumferential direction, and the permanent magnet is A permanent magnet type rotating electric machine characterized in that it is formed by binding magnetic powder, and the particle size of the magnetic powder varies depending on the position. By configuring in this way, it is possible to use a magnetic powder having large particles in a place where excellent magnetic properties are required depending on the application.

  (2) The permanent magnet type rotating electrical machine according to (1), wherein the permanent magnet is formed in a shape having a corner portion, and the particles of the magnetic powder in the corner portion are compared with other portions. Permanent magnet type rotating electrical machine characterized by being large and large. By configuring in this way, it is possible to improve the magnetic characteristics of the corners where demagnetization is severe.

  (3) The permanent magnet type rotating electrical machine according to (1), wherein the permanent magnet has a larger particle size of the magnetic powder on the surface side facing the stator than other portions. Permanent magnet type rotating electric machine. With this configuration, the magnetic characteristics and reliability can be improved.

  (4) A permanent magnet type rotating electrical machine in which a rotor rotates relative to a stator, wherein the stator includes a stator core having a plurality of slots in the circumferential direction, and the slots in the stator core. And the rotor includes a permanent magnet that is magnetized so that different magnetic poles are formed in the circumferential direction. A permanent magnet type rotating electrical machine characterized by binding different types of magnetic powder depending on the location. As described above, since the characteristics of the permanent magnet can be varied depending on the location, it is possible to make the permanent magnet suitable for the desired characteristics.

  (5) The permanent magnet type rotating electrical machine according to (4), wherein the permanent magnet is bound in a state in which different kinds of magnetic powders are arranged in layers. Since the magnetic powder has a flat shape, different types of magnetic powder can be clearly separated by forming different types of magnetic powder in layers, and manufacturing is facilitated.

  (6) The permanent magnet type rotating electrical machine according to (4), wherein the permanent magnet has a high coercivity magnetic powder disposed on a side facing the stator core, and on a side away from the stator core. A permanent magnet type rotating electric machine characterized by arranging magnetic powder having a high residual magnetic flux density. By configuring in this way, the magnetic powder with a high residual magnetic flux density has less rare earth content than the magnetic powder with a high coercive force, and the magnetic flux density is higher than when the whole is formed with a magnetic powder with a high coercive force, High torque and low cost can be achieved.

(7) The method for manufacturing a permanent magnet type rotating electrical machine according to (4), wherein the permanent magnet is formed by compressing each magnetic powder separately or simultaneously in the same mold, and then forming a precursor of SiO ₂ A method for manufacturing a permanent magnet type rotating electrical machine, wherein the body is impregnated and molded. By comprising in this way, it becomes possible to manufacture easily the permanent magnet from which a characteristic changes with places.

  (8) A permanent magnet type rotating electrical machine in which a rotor rotates relative to a stator, wherein the stator includes a stator core having a plurality of slots in a circumferential direction, and the slots in the stator core. The rotor is arranged on the outer periphery of the rotor core and magnetized so that different magnetic poles are formed in the circumferential direction. The permanent magnet is formed in a cylindrical shape by binding magnetic powder with a SiO-based material and attached to the rotor core. Permanent magnet type rotating electric machine. By comprising in this way, the number of parts of a permanent magnet can be reduced and assembly property can also be improved. Further, it is possible to prevent the permanent magnet from falling off even when centrifugal force is applied.

  (9) A permanent magnet type rotating electrical machine in which a rotor rotates relative to a stator, wherein the stator includes a stator core having a plurality of slots in a circumferential direction, and the slots in the stator core. The rotor has a permanent magnet that is magnetized so that different magnetic poles are formed in the circumferential direction, and the permanent magnet is A permanent magnet type rotating electrical machine characterized by having both an anisotropic place and an isotropic place. In this way, the permanent magnet can be made isotropic or anisotropic depending on the location, so that it is possible to make the permanent magnet suitable for the desired characteristics.

  (10) A permanent magnet type rotating electrical machine according to (9), characterized in that a side close to the adjacent pole is made anisotropic and isotropic between the sides. By comprising in this way, magnetization can be performed favorably.

  (11) A permanent magnet type rotating electrical machine in which a rotor rotates relative to a stator, wherein the stator includes a stator core having a plurality of slots in a circumferential direction, and the slots in the stator core. The rotor has a permanent magnet that is magnetized so that different magnetic poles are formed in the circumferential direction, and the permanent magnet is A permanent magnet type rotating electrical machine characterized in that it is configured by binding flat magnetic powders, and each of the magnetic powders has a flat surface facing substantially toward the stator core. If comprised in this way, the outstanding magnetic characteristic can be acquired rather than the surface of the side which is not flat turned to a stator side.

  (12) A permanent magnet type rotating electrical machine in which a rotor rotates relative to a stator, wherein the stator includes a stator core having a plurality of slots in a circumferential direction, and the slots in the stator core. The rotor has a permanent magnet that is magnetized so that different magnetic poles are formed in the circumferential direction, and the permanent magnet is A permanent magnet type rotating electrical machine, characterized in that it is configured by binding flat magnetic powder, and the magnetic powder has a flat surface whose direction substantially coincides with the direction of magnetization. By comprising in this way, magnetization can be performed favorably.

  (13) A permanent magnet type rotating electrical machine in which a rotor rotates relative to a stator, wherein the stator includes a stator core having a plurality of slots in the circumferential direction, and the slots in the stator core. The rotor has a permanent magnet that is magnetized so that different magnetic poles are formed in the circumferential direction, and the permanent magnet is A permanent magnet type rotating electrical machine, characterized in that it is formed by binding flat magnetic powder, and the direction of the flat surface of the magnetic powder substantially coincides with the direction in which stress acts. By comprising in this way, durability of the permanent magnet with respect to stress can be improved.

  (14) The permanent magnet type rotating electrical machine according to (13), wherein the direction of the flat surface of the magnetic powder is substantially the same as the direction in which the centrifugal force acts. Magnet rotating electric machine. By comprising in this way, durability of the permanent magnet with respect to the centrifugal force which acts when a rotor rotates can be improved.

  (15) A hybrid vehicle driven by an engine and a rotating electrical machine, wherein the rotating electrical machine can rotate at a higher speed than the first rotating electrical machine that mainly drives the vehicle and the first rotating electrical machine. A second rotating electrical machine that is capable of generating electric power and has a maximum torque smaller than that of the first rotating electrical machine. The first rotating electrical machine uses a sintered magnet as a magnetic pole, The second rotating electrical machine uses a permanent magnet in which magnetic powder is bound with a SiO-based material as a magnetic pole, and is configured to obtain more reluctance torque than the first rotating electrical machine. A hybrid vehicle characterized by that. Note that the first rotating electrical machine may not obtain reluctance torque. By configuring in this way, the first rotating electrical machine is small and can obtain a high torque, and the second rotating electrical machine can reduce the iron loss when it is rotated at the time of high speed rotation. Overall efficiency can be improved.

(16) A rotating electrical machine in which a rotor rotates relative to a stator, wherein the stator is wound around a stator core having a plurality of slots in a circumferential direction and the slots of the stator core. The rotor is composed of a rotor core formed by laminating steel plates and a magnetic pole portion that generates different magnetic poles in the circumferential direction of the rotor core. A rotating electrical machine characterized in that SiO ₂ is interposed between the steel plates in the rotor core. By immersing the laminated steel sheets in the SiO ₂ precursor, the low viscosity SiO ₂ precursor can enter between the steel sheets and bind the steel sheets together.

(17) A rotating electrical machine in which a rotor rotates relative to a stator, wherein the stator is wound around a stator core having a plurality of slots in a circumferential direction and the slots of the stator core. The rotor has different magnetic poles in the circumferential direction, and a SiO ₂ layer is formed on the surface of the stator winding. A rotating electric machine that is characterized. Since the precursor of SiO ₂ has a low viscosity, it is possible to form an insulating layer on each of the coils wound in a bundle. Thus, by applying the precursor of SiO ₂ , it is possible to perform a surface treatment with a high hardness having an insulating function in any narrow area.

1 is a system diagram showing an embodiment of the present invention. The electric circuit for driving the rotary electric machine of FIG. Sectional drawing along the rotating shaft of the rotary electric machine of FIG. Sectional drawing in a surface perpendicular | vertical to the rotating shaft of the rotary electric machine of FIG. Sectional drawing of a concentrated winding motor. The Example regarding the fixing method of a magnet. The figure explaining the manufacturing process of a magnet assembly. The other Example in the manufacturing process of a magnet assembly. The other Example in the manufacturing process of a magnet assembly. Sectional drawing of the manufactured magnet. The figure which shows the experimental result of a magnet. The block diagram of electric power steering. 14 is a circuit configuration for moving FIG. Typical sectional drawing of the motor for EPS. An embodiment in which the image is skewed in two. An embodiment in which the skew is divided into three. Relationship between skew method and cogging torque. Magnet shape as an example of continuous skew method. The principle that the skew eliminates the torque pulsation. Example of a substantially skew-shaped magnet having a substantially V-shape. A device that measures the unbalance of a rotor. Harmonic component of magnetomotive force in a 2-pole 6-slot or 2-pole 12-slot motor. Harmonic component of magnetomotive force in 8-pole 9-slot or 10-pole 9-slot motor. Harmonic component of magnetomotive force in 2-pole 3-slot series and 4-pole 3-slot series motors. Harmonic component of magnetomotive force in 10 pole 12 slot and 14 pole 2 slot motors. The figure which drawn rare earth magnetic powder typically. The figure which showed typically the arrangement | sequence of the magnetic powder at the time of compressing and molding magnetic powder. The figure which showed the kamaboko type permanent magnet. The figure which showed the state which attached the kamaboko type permanent magnet to the rotor core in a cross section perpendicular to the rotation axis. Explanatory drawing of the manufacturing method of a cylindrical magnet. The figure which shows the state which carried out the cross section of the rotor using the cylindrical magnet which made the stator side surface curved in the surface perpendicular | vertical to a rotating shaft.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Electric vehicle 200,202 Rotating electric machine 230 Stator 232 Stator iron core 250 Rotor 252 Rotor iron core 254,256 Permanent magnet 300 EPS
401 Permanent magnet rotating electric machine

Claims (31)

A permanent magnet type rotating electrical machine in which the rotor rotates relative to the stator,
The stator is composed of a stator core having a plurality of slots in the circumferential direction, and a stator winding wound in the slot of the stator core.
The rotor is arranged with permanent magnets magnetized so that different magnetic poles are alternately formed in the circumferential direction on the surface of the rotor core facing the stator core,
The permanent magnet rotating electric machine is characterized in that the permanent magnet is formed by binding magnetic powder with a SiO-based material.   2. The permanent magnet type rotating electrical machine according to claim 1, wherein dents are formed at regular intervals in the circumferential direction on the surface of the rotor core of the rotor, and the magnetic powder is made of SiO-based material in each of the dents. A permanent magnet type rotating electrical machine in which a permanent magnet configured by binding is disposed. In the permanent magnet type rotating electrical machine according to claim 1,
The stator is configured by winding the three-phase stator windings intensively in the slots of the stator core,
When the number of poles of the permanent magnet in the rotor is P and the number of slots in the stator core is N, the relationship 2/3 <= P / N <= 4/3 is satisfied. Rotating electric machine. In the permanent magnet type rotating electrical machine according to claim 1,
The permanent magnet type rotating electrical machine, wherein the permanent magnet in the rotor is arranged so as to be shifted in a circumferential direction with respect to a direction parallel to a rotation axis of the rotor. In the permanent magnet type rotating electrical machine according to claim 4,
A permanent magnet type rotating electrical machine characterized in that the permanent magnet is continuously displaced in the circumferential direction. In the permanent magnet type rotating electrical machine according to claim 4,
The permanent magnet type rotating electrical machine, wherein the permanent magnet is magnetized so as to be substantially V-shaped in a direction parallel to a rotation axis of the rotor. In the permanent magnet type rotating electrical machine according to claim 1,
The permanent magnet type rotating electric machine, wherein at least one of the permanent magnets is formed by cutting. In the permanent magnet type rotating electrical machine according to claim 1,
A permanent magnet type rotating electrical machine, wherein a three-phase alternating current is supplied to the stator winding to generate a rotational torque in the rotor. The permanent magnet type rotating electrical machine according to claim 8,
A permanent magnet type rotating electrical machine that is used as a drive source for a hybrid vehicle. The permanent magnet type rotating electrical machine according to claim 8,
A permanent magnet type rotating electrical machine used for an electric power steering device for a vehicle. A method of manufacturing a permanent magnet type rotating electrical machine in which a rotor rotates relative to a stator,
The stator is manufactured by a step of forming a stator core having a plurality of slots in the circumferential direction, and a step of winding a stator winding in the slot of the stator core.
The rotor is manufactured by a step of forming a rotor core and a step of fixing the permanent magnets so that different magnetic permanent magnets are alternately arranged in the circumferential direction on the surface of the rotor core,
Further, the permanent magnet is formed by pressure-molding a magnetic powder coated with an inorganic insulating film, and the pressure-molded body is impregnated with a binder solution having a viscosity at 30 ° C. of 0.52 to 100 mPa · s. A method of manufacturing a permanent magnet type rotating electrical machine, characterized by being manufactured by a step of applying a heat treatment to the pressure-formed body. A method of manufacturing a permanent magnet type rotating electrical machine in which a rotor rotates relative to a stator,
The stator is manufactured by a step of forming a stator core having a plurality of slots in the circumferential direction, and a step of winding a stator winding in the slot of the stator core.
The rotor is manufactured by a step of forming a rotor core and a step of fixing the permanent magnets so that different magnetic permanent magnets are alternately arranged in the circumferential direction on the surface of the rotor core,
Further, the permanent magnet is formed by pressure-molding a magnetic powder coated with an inorganic insulating film, impregnating the pressure-molded body with a SiO-based material, and subjecting the pressure-molded body to a heat treatment. A method of manufacturing a permanent magnet type rotating electrical machine, characterized by being manufactured by a process. In the manufacturing method of the permanent magnet type rotating electrical machine according to claim 12,
A manufacturing method of a permanent magnet type rotating electrical machine, wherein the permanent magnet is cut to adjust an unbalance of the plurality of permanent magnets. A method of manufacturing a permanent magnet type rotating electrical machine in which a rotor rotates relative to a stator,
The stator is manufactured by a step of forming a stator core having a plurality of slots in the circumferential direction, and a step of winding a stator winding in the slot of the stator core.
The rotor is manufactured by a step of forming a rotor core and a step of fixing the permanent magnets so that different magnetic permanent magnets are alternately arranged in the circumferential direction on the surface of the rotor core,
Further, the permanent magnet is formed by pressure-molding a magnetic powder coated with an inorganic insulating film, impregnating the pressure-molded body with a SiO-based material, and subjecting the pressure-molded body to a heat treatment. A method of manufacturing a permanent magnet type rotating electrical machine, comprising: a step, a step of cutting the pressure formed body, and a step of applying antiseptic measures to a cutting portion of the pressure formed body. A method of manufacturing a permanent magnet type rotating electrical machine in which a rotor rotates relative to a stator,
The stator is manufactured by a step of forming a stator core having a plurality of slots in the circumferential direction, and a step of winding a stator winding in the slot of the stator core.
The rotor is manufactured by a step of forming a rotor core and a step of fixing the permanent magnets so that different magnetic permanent magnets are alternately arranged in the circumferential direction on the surface of the rotor core,
Furthermore, the permanent magnet includes a step of pressure-molding magnetic powder coated with an inorganic insulating film, a step of impregnating the pressure-molded body with a precursor of SiO ₂ , and heat-treating the pressure-molded body. The manufacturing method of the permanent-magnet-type rotary electric machine characterized by the above-mentioned. In the manufacturing method of the permanent magnet type rotating electrical machine according to claim 12,
The binder solution contains at least one of alkoxysiloxane, alkoxysilane, a hydrolysis product thereof, and a dehydration condensate thereof, and water, and is formed from an alcohol and a hydrolysis catalyst if necessary. A method for manufacturing a permanent magnet type rotating electrical machine. In the manufacturing method of the permanent magnet type rotating electrical machine according to claim 12,
The method of manufacturing a permanent magnet type rotating electrical machine, wherein the pressure-molded body is molded into a shape having a curved surface. An automobile equipped with a permanent magnet type rotating electrical machine in which the rotor rotates relative to the stator,
The rotor includes a rotor core and permanent magnets arranged on the outer peripheral side of the rotor core in order to create an even number of field poles in the circumferential direction of the rotor, and the permanent magnet has alternating polarity of the field poles Is magnetized to reverse
The permanent magnet is constituted by binding magnetic powder with a binder,
An automobile having a permanent magnet type rotating electrical machine, wherein the binder is made of a material whose precursor has good wetting characteristics with respect to the magnetic powder. In the motor vehicle provided with the permanent magnet type rotating electrical machine according to claim 18,
An automobile equipped with a permanent magnet type rotating electrical machine, wherein the binder contains SiO ₂ as a main component and an alkoxy group. In the motor vehicle provided with the permanent magnet type rotating electrical machine according to claim 19,
The binder, in its precursor, alkoxysiloxane, alkoxysilane which is a precursor of SiO _2, its hydrolysis products, and and at least one water of dehydration condensation product, if further necessary and alcohol An automobile equipped with a permanent magnet type rotating electrical machine, characterized in that it is formed from a catalyst for hydrolysis. In the motor vehicle provided with the permanent magnet type rotating electrical machine according to claim 18,
An automobile equipped with a permanent magnet type rotating electrical machine, wherein the magnetic powder is provided with an inorganic insulating film having a thickness of 10 μm to 10 nm. In the motor vehicle provided with the permanent magnet type rotating electrical machine according to claim 18,
The automobile provided with a permanent magnet type rotating electric machine, wherein the permanent magnet is continuously skewed. Having a stator and a rotor arranged rotatably,
The stator has a stator core and a stator winding wound around the stator core;
The rotor has a rotor core and a plurality of permanent magnets respectively constituting a plurality of field poles provided in the circumferential direction of the rotor core;
The permanent magnet is arranged such that the stator side surface is located on the stator side with respect to the stator side surface of the rotor core, and the permanent magnets constituting the field pole are of opposite polarity for each field pole. Is magnetized so that
The permanent magnet rotating electric machine is characterized in that the permanent magnet is formed by binding magnetic powder with a SiO-based material. A stator having a stator iron core and a three-phase stator winding wound around the stator iron core, and a rotor arranged rotatably.
The rotor includes a rotor core and a plurality of permanent magnets held by the rotor core;
An even number of field poles constituted by the permanent magnets are formed in the circumferential direction on the rotor, and the permanent magnets constituting the field poles are magnetized with different polarities for each field pole,
The permanent magnet is formed by binding rare earth magnetic powder with an SiO-based material in an amorphous state,
The rare earth magnetic powder forming the permanent magnet has a flat shape having a wide first surface and a narrow second surface,
The rare earth magnetic powder is laminated so that the first surface of the flat-shaped rare earth magnetic powder faces each other, and the laminated rare earth magnetic powder is bound with an amorphous SiO-based binder. An in-vehicle permanent magnet rotating electrical machine in which the permanent magnet is formed. A stator having a stator core and a three-phase stator winding;
A rotor arranged to be rotatable with a gap between the stator and
The rotor includes a rotor core and a plurality of permanent magnets, and the permanent magnet constitutes a field pole of the rotor, and an even number of field poles are formed in the circumferential direction on the rotor. And
The permanent magnet is formed by laminating a flat rare earth magnetic powder having a first surface having a wide width and a second surface having a width smaller than that of the first surface so that the first surface faces each other. A rare earth magnetic powder and a binder containing SiO ₂ as a main component and containing an alkoxy group,
In-vehicle use in which the permanent magnet is formed by binding the flat rare earth magnetic powder forming the permanent magnet with a continuous film-shaped binder in an amorphous state mainly composed of the SiO ₂ Permanent magnet rotating electric machine. The permanent magnet rotating electric machine according to claim 23 to 25,
The magnetic powder has an inorganic insulating film having a thickness of 10 μm to 10 nm on the surface, and the permanent magnet is formed by binding the magnetic powder having the inorganic insulating film with SiO _2. Rotating electric machine. A stator having a stator core and a three-phase stator winding wound around the stator core, and a rotor rotatably disposed with a gap provided between the stator and the stator core; And
The rotor includes a rotor core and a plurality of permanent magnets held by the rotor core;
In the rotor, an even number of field poles constituted by the permanent magnets are arranged at substantially equal intervals in the circumferential direction, and the permanent magnets constituting the field poles are magnetized in reverse polarity for each field pole,
The permanent magnet is formed by binding rare earth magnetic powder with an amorphous binder mainly composed of SiO ₂ ;
The rare earth magnetic powder forming the permanent magnet has a flat shape having a first surface and a second surface that is narrower than the first surface;
The permanent magnet has a laminated structure in which the rare earth magnetic powder is laminated so that the first surfaces face each other, and the laminated rare earth magnetic powder is bound to the amorphous binder. Have
The on-vehicle permanent magnet rotating electric machine, wherein the permanent magnet is held by the rotor so that the first surface of the laminated structure constituting the main structure faces substantially the stator side. The in-vehicle permanent magnet rotating electric machine according to claim 27,
The permanent magnet has a curved shape in which a central portion protrudes toward the stator from both sides in the circumferential direction of the rotor in a cross-sectional state in which the stator side surface is perpendicular to the rotation axis, and further, the main structure is formed. An in-vehicle permanent magnet rotating electrical machine in which the first surface of the laminated structure is formed so as to face substantially the stator side in the cross-sectional state. A stator having a stator core and a three-phase stator winding wound around the stator core, and a rotor rotatably disposed with a gap provided between the stator and the stator core; And
The rotor includes a rotor core and a plurality of permanent magnets held by the rotor core;
In the rotor, an even number of field poles constituted by the permanent magnets are arranged at substantially equal intervals in the circumferential direction, and the permanent magnets constituting the field poles are magnetized in reverse polarity for each field pole,
The permanent magnet is formed by binding rare earth magnetic powder with an amorphous binder mainly composed of SiO ₂ ;
The rare earth magnetic powder forming the permanent magnet has a flat shape having a first surface and a second surface that is narrower than the first surface;
The permanent magnet has a laminated structure in which the rare earth magnetic powder is laminated so that the first surfaces face each other, and the laminated rare earth magnetic powder is bound to the amorphous binder. Have
The permanent magnet is a vehicle-mounted permanent magnet that is held by the rotor so that the first surface of the laminated structure forming the main structure faces a direction substantially along the rotation axis of the rotor. Magnet rotating electric machine. The in-vehicle permanent magnet rotating electric machine according to claim 29,
The permanent magnet has a curved shape in which a central portion protrudes toward the stator from both sides in the circumferential direction of the rotor in a cross-sectional state in which the stator side surface is perpendicular to the rotation axis, and further, the main structure is formed. An in-vehicle permanent magnet rotating electrical machine in which the first surface of the laminated structure is formed so as to face a direction substantially along the rotation axis in the cross-sectional state. The in-vehicle permanent magnet rotating electrical machine according to claim 27 to claim 30,
A permanent magnet rotating electrical machine for vehicle use in which the binder mainly composed of SiO ₂ contains an alkoxy group.

Images