JP4862049B2 - Permanent magnet rotating electric machine - Google Patents

Description

  The present invention relates to a rotating electrical machine technology that uses a permanent magnet.

A sintered magnet produced by sintering a rare earth magnet material as a permanent magnet having excellent magnetic properties. Although this sintered magnet has excellent magnetic properties, there is a problem that the electric resistance in the magnet is small and eddy current flows.
A so-called bonded magnet in which a magnet material is hardened with an epoxy resin increases the electric resistance in the magnet due to the resin, but has a problem that the magnetic characteristics are remarkably deteriorated. This bonded magnet is a magnet manufactured by mixing a thermosetting epoxy resin and a magnet material, and molding the mixture, and the magnet material is bonded with the epoxy resin. It is necessary to increase the ratio of the epoxy resin for adhering the magnet material to the magnet material, and there is a problem that the amount of the magnet material per unit volume is lowered and the magnetic properties are lowered.
Magnets using an epoxy resin are disclosed in the following Patent Documents 1 to 3. In these Patent Documents, techniques relating to improvement of magnetic characteristics and the like are disclosed.
Magnets using SiO ₂ instead of epoxy resin are disclosed in the following Patent Documents 4 to 5. Patent Document 4 discloses a technique for binding a ferrite magnet material with SiO ₂ . Patent Document 5 discloses a technique using particulate SiO ₂ in order to increase the electric resistance of a rare earth magnet.
Japanese Patent Laid-Open No. 11-238640 Japanese Patent Laid-Open No. 11-067514 Japanese Patent Laid-Open No. 10-208919 Japanese Patent Laid-Open No. 08-115809 Japanese Patent Laid-Open No. 10-32427

Rare earth permanent magnets have a problem that the internal resistance is low and eddy current flows and heat is generated inside the magnet. Of course, to improve the efficiency of the rotating electrical machine, it is necessary to keep the eddy current loss of the rotating electrical machine low, and from the viewpoint of efficiency in addition to heat generation, it is desirable to increase the internal resistance of the rare earth permanent magnet. Although the magnet using the epoxy resin can increase the electric resistance, there is a problem that the magnetic properties of the magnet are deteriorated. A rotating electrical machine that can suppress the heat generation of the magnet while reducing the decrease in magnetic properties is desirable.
In particular, a rotating electrical machine mounted on an automobile is often used in a severer environment due to temperature compared to a rotating electrical machine installed in a place with a good temperature environment such as in a factory. When the temperature of the rare earth permanent magnet increases due to the internal heat generation of the rare earth permanent magnet and the increase in ambient temperature, there is a problem that the magnetic properties of the magnet deteriorate. Increasing the electrical resistance in the magnet has the effect of reducing the heat generation in the magnet, and it is desirable to reduce the heat generation from the viewpoint of reliability in a rotating electrical machine mounted on an automobile.
An object of the present invention is to provide a highly reliable rotating electrical machine that uses a permanent magnet.
A feature of the present invention is that a permanent magnet using a binder having good wettability with a rare earth magnet material as a precursor is used in a permanent magnet rotating electric machine. In the present invention, a thin SiO binder film in an amorphous state can be formed between rare earth magnet materials by using a binder having good wettability with the magnet material. With this binding film, the rare earth magnet material can be bound, and the thin film can increase the electrical resistance between the rare earth magnet materials and suppress eddy currents.
A SiO-based precursor, for example, a precursor of SiO ₂ can be used as a binder whose precursor has good wettability with the rare earth magnet material. By binding the rare earth magnet material with the SiO-based binder in this way, it is possible to suppress a decrease in the magnetic properties of the permanent magnet that occurs when an epoxy resin is used as the binder. By using this magnet, a rotating electrical machine with good characteristics can be obtained.
A sintered magnet obtained by sintering rare earth magnet material has low electric resistance, eddy current flows inside the magnet, and heat is generated inside the magnet.
By using the present invention, the reliability is improved in a permanent magnet or a rotating electrical machine using a permanent magnet. That is, internal heat generation can be suppressed in a rotating electrical machine used in a severe temperature environment such as a situation where it is mounted on an automobile. As a result, it is possible to provide a rotating electrical machine suitable for maintaining high reliability by using the present invention.

FIG. 1 is a configuration diagram showing a configuration of an electric vehicle including a rotating electrical machine to which the present invention is applied.
FIG. 2 is an electric circuit diagram of the power converter.
FIG. 3 is a cross-sectional view along the rotation axis of the rotating electrical machine.
FIG. 4 is a cross-sectional view of the stator and the rotor on a plane perpendicular to the rotation axis of the rotating electrical machine.
FIG. 5 is an enlarged view of a magnetic pole portion of the rotor shown in FIG.
FIG. 6 is a diagram showing a d-axis magnetic flux in the stator and the rotor shown in FIG.
FIG. 7 is a diagram showing a q-axis magnetic flux in the stator and the rotor shown in FIG.
FIG. 8 is a diagram showing a manufacturing process of a magnet assembly.
FIG. 9 is a diagram showing another embodiment of the manufacturing process of the magnet assembly.
FIG. 10 is a view showing still another embodiment of the manufacturing process of the magnet assembly.
FIG. 11 is a cross-sectional view of the manufactured magnet.
FIG. 12 shows the experimental results of the manufactured magnet.
FIG. 13 is a partial cross-sectional view showing another embodiment of the rotor shown in FIG.
FIG. 14 is a view showing the magnetic flux intensity of the portion shown in FIG.
FIG. 15 is a sectional view showing still another embodiment of the rotating electrical machine to which the present invention is applied.
FIG. 16 is a diagram showing a process of manufacturing a magnet assembly.
FIG. 17 is a view showing another embodiment of a process for producing a magnet assembly.
FIG. 18 is a diagram for explaining a process of impregnating a compression-molded magnetic body with a binder precursor.
FIG. 19 is a cross-sectional view illustrating another structure of the magnet assembly.
FIG. 20 is a perspective view for explaining still another embodiment of the magnet assembly.
FIG. 21 is a perspective view for explaining still another embodiment of the magnet assembly.
FIG. 22 is a sectional view showing still another embodiment of the rotating electrical machine to which the present invention is applied.
FIG. 23 is a cross-sectional view showing still another embodiment of a rotor to which the present invention is applied.
FIG. 24 is a partial enlarged view of a cross section showing still another embodiment of a rotor to which the present invention is applied.
FIG. 25 is a partial enlarged view of a cross section showing still another embodiment of a rotor to which the present invention is applied.
FIG. 26 is a sectional view showing still another embodiment of the rotating electrical machine to which the present invention is applied.
FIG. 27 is a cross-sectional view showing still another embodiment of a rotor to which the present invention is applied.
FIG. 28 is a view for explaining still another method of manufacturing a rotor to which the present invention is applied.

In the embodiment described below, the iron powder is hardened to form part or all of the stator core or the rotor core, or both the stator core and the rotor core are formed. For this reason, in addition to the reduction of eddy current loss in the above-described permanent magnet, eddy current loss inside the stator core or rotor core can be suppressed, and internal heat generation can be suppressed. Furthermore, in addition to heat generation reduction, the efficiency of the rotating electrical machine can be improved. For example, the electrical resistance is 5 to 10 times that of a conventional sintered type permanent magnet, and even higher in some cases, and heat generation due to eddy current can be reduced.
In the embodiment described below, a thin amorphous film is formed between plate-like rare earth magnet materials, and the plate-like rare earth magnet materials are bound to each other by this film. The binder can be in the form of a thin film. As a result, the ratio of the rare earth magnet material per unit volume of the magnet is increased, and good magnetic properties are obtained. On the other hand, the electric resistance between the rare earth magnet materials is increased by the thin film of the binder, and the internal resistance of the magnet is increased.
For example, 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.
In the following embodiments, the following excellent effects are further obtained. In the rare earth sintered magnet, it is necessary to heat the rare earth magnet material to a high temperature in order to sinter, and a process to heat to the sintering temperature is required, which increases the production cost of the magnet or rotating electric machine including the equipment cost. .
Moreover, the shape and dimension after a sintering process will change with respect to the shape and dimension before a sintering process by the sintering process which heats a magnet material to final temperature. Therefore, in the molding process after the sintering process, a molding operation including significant cutting is required to obtain dimensional accuracy. In the embodiment of the present invention described below, since the magnet can be manufactured at a relatively low temperature, the magnet material can be bound while maintaining the shape and dimensions of the magnet material by press molding with high accuracy. . As a result, it becomes easy to produce magnets with high accuracy. For this reason, the magnet after being hardened by the binder is much easier to form than the sintered magnet, and in some cases, cutting is not required.
It is not easy to cut a magnet into a shape having a curve. Cutting a simple curve such as a circle is easy, but cutting a complicated curve is not easy. When machining a magnet into a curved shape, press working is easier than cutting. However, sintered magnets need to be heated to a high temperature for sintering as described above, and cutting is always required after the sintering process. In the embodiment of the present invention described below, since it is not necessary to heat to the sintering temperature after the press working, the shape and dimensional relationship of the press working are maintained with high accuracy even after the binding process of the magnet material. . For this reason, the final shape of the magnet is often obtained by a slight cutting process, and in some cases, the magnet can be completed without a cutting operation.
According to the present invention, it is possible to easily produce a curved magnet that has been difficult to manufacture. As a result, the characteristics of the rotating electrical machine can be improved.
In the embodiment described below, the magnet material processed after pressing the magnet material is attached to the motor part, for example, inserted into the magnet insertion hole of the rotor, and then the binding work for infiltrating the binder is performed. Is possible. According to this method, in the magnet material binding step, not only the magnet material but also the magnet material and the rotating electrical machine component in the vicinity of the magnet can be bound together. For example, the inner surface of the magnet insertion hole and the inserted magnet can be bonded simultaneously. This improves workability. In addition, the durability of the magnet or the rotary electric component including the magnet is improved. If it is strong, durability or reliability of a rotary electric machine will improve.
<Electric vehicle 100>
FIG. 1 is a block diagram showing an embodiment of a hybrid electric vehicle equipped with a rotating electrical machine 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. Alternatively, 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 for controlling the transmission 130, an engine control device 124 for controlling the engine 120, a power conversion device 600, a battery control device 184 for controlling a battery 180 such as a lithium ion battery, and an integrated control device 170, Each is connected by a communication line 174.
The integrated control device 170 transmits information representing 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 control devices than the integrated control device 170, to the communication line. Receive via 174. Based on these pieces of information, the integrated control device 170 calculates a control command for each control device, and a 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.
When the integrated control device 170 determines from the report that the battery 180 needs to be charged, the integrated control device 170 instructs the power conversion device 600 to perform a power generation operation. The integrated controller 170 also manages the output torque of the engine 120 and the first and second rotary electric machines 200 and 202, and the total torque or torque distribution of the output torque of the engine and the first and second rotary electric machines 200 and 202. The ratio is calculated 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 power semiconductors constituting an 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, the power conversion device 600 includes a capacitor module containing a plurality of smoothing capacitors that suppresses voltage fluctuations of the DC power supply, a power module containing a plurality of power semiconductors, and a switching operation of the power module. The rotating electric machine control circuit includes a switching drive circuit to be controlled 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. Output from the battery.
<Description of electrical circuit>
FIG. 2 is a circuit diagram of power converter 600 shown in FIG. The power converter 200 includes a first inverter for generating three-phase AC power to be supplied to the first rotating electric machine 200 or for converting three-phase AC power from the first rotating electric machine 200 into DC power. The apparatus and the second rotary electric machine for generating three-phase AC power to be supplied to the second rotary electric machine 202 or converting the three-phase AC power from the second rotary electric machine second rotary electric machine 202 into DC power A second inverter device is provided. The first inverter device includes a first power module 610, a first drive circuit 652 that controls the switching operation of each power semiconductor 21 that constitutes each arm of the inverter built in the first power module 610, A current sensor 660 for detecting the current of the rotating electrical machine 200, a control circuit 648 used in common with a second inverter device described below, a transmission / reception circuit 644 mounted on the connector board 642, and a capacitor module 630 are provided. ing. 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 that constitutes each arm of the inverter built in the second power module 620, A current sensor 662 for detecting the current of the rotating electrical machine 202, a control circuit 648 used in common with the first inverter, a transmission / reception circuit 644, and a capacitor module 630 are provided. The second drive circuit 656 is mounted on the second drive circuit board 654, the control circuit 648 is mounted on the 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. The 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.
<Description of Power Modules 610 and 620>
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 respectively connected to the positive side and the negative side of the battery 180. Are electrically 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) is used as the switching power semiconductor 21. The IGBT 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. The diode 38 has two electrodes, a cathode electrode and an anode electrode. The cathode electrode is the collector electrode of the IGBT and the anode electrode is the IGBT so that the direction from the emitter electrode to the collector electrode of the IGBT 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. Since the MOSFET includes a parasitic diode between the source electrode and the drain electrode in which the direction from the drain electrode to the source electrode is the forward direction, there is no need to provide the diode 38 in FIG.
The series circuit of each phase is configured by electrically connecting an emitter electrode of the IGBT as the upper arm and a collector electrode of the IGBT as the lower arm in series. In this embodiment, one IGBT for each upper and lower arm of each phase is not shown, but since the current capacity to be controlled is large, a plurality of IGBTs are actually electrically connected in parallel. ing. In order to simplify the explanation below, each arm of the inverter will be described as being composed of one power semiconductor 21.
In the embodiment shown in FIG. 2, each upper and lower arm of each phase is constituted by three power semiconductors 21. The collector electrode of the power semiconductor 21 of each upper arm of each phase is electrically connected to the positive electrode side of the battery 180, and the emitter electrode of the power semiconductor 21 of each lower arm of each phase is electrically connected to the negative electrode side of the battery 180.
Each phase of each arm, that is, the middle point of the series circuit, that is, the connection portion between the emitter electrode of the upper arm side IGBT and the collector electrode of the IGBT on the lower arm side becomes each phase of the three-phase AC power. It is electrically connected to the corresponding phase armature winding.
The first and second drive circuits 652 and 656 constitute a drive unit for controlling each inverter device of the corresponding first and second power modules 610 and 620, and are output from the control circuit 648. Based on the control signal, a signal for controlling the power semiconductor 21 is generated. Signals generated by the drive circuits 652 and 656 are output to the gates of the power semiconductors of the corresponding first power module 610 and second power module 620, respectively. In this embodiment, two integrated circuits for generating respective signals to be supplied to the gates of the upper and lower arms of each phase are incorporated in one integrated circuit. Since the first power module 610 and the second power module 620 have twelve upper or lower arms in total, the drive circuits 652 and 656 have the six integrated circuits, and these six integrated circuits. A circuit is housed in one block. In other words, the drive circuits 652 and 656 are constituted by the partially locked integrated circuit.
The control circuit 648 constitutes a control unit of the first and second power modules 610 and 620, and a control value, that is, an operation timing for operating (turning on or off) the plurality of power semiconductors 21 constituting the inverter circuit. It comprises a microcomputer that computes. 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 of the power semiconductor 21 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 with other apparatuses via the communication line 174 in FIG. Send and receive.
The capacitor module 630 is for constituting a smoothing circuit for suppressing fluctuations in the DC voltage generated by the switching operation of the power semiconductor 21, and is provided on the DC side of the first power module 610 and the second power module 620. The terminals are electrically connected in parallel by a DC bus bar having a laminated structure of plate-like conductors arranged to face each other with an insulating sheet interposed therebetween.
<Description of Rotating Electric Machine 200 or 202>
FIG. 3 is a cross-sectional view of the rotating electrical machine 200 or 202 shown in FIGS. The rotating electric machines 200 and 202 have substantially the same structure, and the structure of the rotating electric machine 200 will be described with reference to FIGS. 3 to 6 as representative examples thereof. FIG. 4 is an AA cross section of the stator 230 and the rotor 250 shown in FIG. 3, and illustration of the housing 212 and the shaft 218 is omitted.
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 stator core 232 and the rotor core 252 are formed by compressing iron powder that has been subjected to a process of attaching an electrical insulating film to the surface. The stator core 232 has a structure formed by compressing iron powder. By taking such a structure, the stator winding is first molded, then the stator winding is temporarily fixed, and the temporarily fixed stator winding is built in and filled with iron powder. Next, the entire iron powder is compression-molded to produce the entire stator, thereby improving productivity and improving the space factor of the stator winding. Furthermore, eddy current can be reduced and the efficiency of the rotating electrical machine is improved.
The rotor core 252 can be reduced in eddy current of the rotor core 250 by compressing and molding the iron powder that has been subjected to the process of attaching an electrical insulating film to the surface. Further, the permanent magnets 254 and 256 described below have a structure for reducing eddy current, and the internal heat generation of the rotor 250 can be reduced comprehensively. Rare earth permanent magnets have the disadvantage that their magnetic properties deteriorate, that is, demagnetize when the temperature rises. In-vehicle rotating electrical machines are often used in situations where the ambient temperature is high, and reducing internal heat generation is very preferable for maintaining high reliability.
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 a control circuit 648 shown in FIG. 2, and the first and second power modules 610 and 620 are controlled based on the outputs of these sensors.
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, the stator core 232 has a large number of slots 234 and teeth 236 evenly in the circumferential direction, and the slot 234 has a stator winding 238. Yes. There are two methods for winding the stator winding: distributed winding and concentrated winding. In this embodiment, both winding methods can be applied. In FIG. 4, teeth 236 and slots 234 are provided on the entire rotor side of the stator. Since all these symbols are complicated, only some teeth and slots are represented by symbols.
The rotor core 252 is provided with permanent magnet insertion holes for inserting permanent magnets 254 and 256, and the permanent magnets 254 and 256 are inserted into the permanent magnet insertion holes. The magnetization direction of the permanent magnets 254 and 256 is a direction in which the side surface of the stator of the magnet is an N pole or an S pole, and the magnetization direction is reversed for each pole of the rotor.
The permanent magnets 254 and 256 may be magnetized and inserted into the permanent magnet insertion hole in a state of becoming a permanent magnet, or the magnets may be inserted in a state where the permanent magnets 254 and 256 are not magnetized (hereinafter referred to as a magnet body). The magnet may be inserted into the insertion hole and magnetized by applying a strong magnetic field after being inserted into the magnet insertion hole, so that a permanent magnet may be obtained. Inserting a magnet body that is not magnetized into the magnet insertion hole and magnetizing the magnet body after insertion improves the productivity of the rotating electrical machine. That is, these permanent magnets are magnets made of a very strong rare earth material. When magnetized before being inserted into the magnet insertion hole, a strong attractive force is generated between the rotor core 252 and the centripetal force is used for insertion work. Hinder. Moreover, there is a possibility that dust such as iron powder adheres to the permanent magnet due to the strong attractive force.
In the embodiment shown in FIG. 4, the permanent magnets 254 and 256 act as one pole of the rotor 250. The 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 eight poles. However, the application object to which the present invention is applied is not fixed to 8 poles, but may be 10 poles or more and 30 poles or more in some cases. However, the number of poles is determined by the required output as a motor. Further, when the number of poles is increased, the number of magnets increases and workability decreases. In some cases, it may be 8 or less. The portion of the rotor core existing on the stator side of the permanent magnets 254 and 256 acting as each pole of the rotor 250 acts as a magnetic pole piece 280, and the magnetic lines of force entering and exiting the permanent magnets 254 and 256 are fixed through this magnetic pole piece 280. Enter and exit the child core 232.
As described above, the permanent magnets 254 and 256 acting as the poles of the rotor 250 are magnetized in the opposite directions for each pole so that the magnets 254 and 256 of a certain pole are the N pole on the stator side and the S pole on the shaft side. Are magnetized such that the permanent magnets 254 and 256 acting as poles on both sides thereof are S-pole on the stator side and N-pole on the shaft side. A portion acting as an auxiliary magnetic pole 290 exists between the poles of the rotor 250, and the reluctance is determined by the difference in magnetic resistance between the q-axis magnetic flux passing through the auxiliary magnetic pole 290 and the d-axis magnetic flux passing through the magnet. Generate torque. Between the auxiliary magnetic poles 290 and the magnetic pole pieces 280, there are bridge portions 282 and 284, respectively. In the bridge portions 282 and 284, the magnetic circuit 262 and 264 narrow the cross-sectional area of the magnetic circuit. Yes. For this reason, a magnetic saturation phenomenon occurs in each of the bridge portions 282 and 284, and the amount of magnetic flux passing between the magnetic pole piece 280 and the auxiliary magnetic pole 290, that is, passing through the bridge portions 282 and 284 is suppressed to a predetermined amount or less.
<Description of Permanent Magnets 254 and 256>
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 that has a good affinity between the neodymium (Nd) and a precursor. Yes. Here affinity excellent precursor precursor of the binder in the SiO-based, is alkoxysiloxane or alkoxysilane such as SiO ₂ precursors. 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. Residual properties are improved. 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. When neodymium (Nd) further contains dysprosium (Dy), the characteristics are improved, and more preferable characteristics can be obtained as a vehicular rotating electrical machine. 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%. A magnet having a structure in which a rare earth magnet material powder is bound with a binder will be described in detail later.
3 and 4, the first drive circuit 652 shown in FIG. 2 controls the first power module 610 based on the outputs of the rotational speed sensor 226 and the rotor position sensor 224 of the rotor. A control signal is generated and transmitted to the first power module 610. The first power module performs a switching operation based on the control signal, and converts DC power supplied from the battery 180 into three-phase AC power. The three-phase alternating current power is supplied to the stator winding 238 shown in FIGS. 3 and 4, and the frequency of the three-phase alternating current is controlled based on the detection value of the rotational speed sensor 226, so that the rotor position sensor Based on the detected value of 224, the phase of the three-phase alternating current with respect to the rotor is controlled.
A rotating magnetic field having the phase and frequency is generated in the stator 230 by the 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. The rotating magnetic field acts on the auxiliary magnetic pole 290 of the rotor 250, and the reluctance torque is applied to the rotor 250 based on the difference in magnetic resistance between the magnetic circuit passing through the magnets 254 and 256 of the rotating magnetic field and the magnetic circuit passing through the auxiliary magnetic pole 290. Is generated. The rotational torque of the rotor 250 is a value determined based on both the torque of the magnet based on the permanent magnet and the reluctance torque based on the auxiliary magnetic pole.
Since the reluctance torque is generated by the difference between the magnetic resistance generated by the stator winding and the magnetic resistance passing through the magnet and the magnetic resistance passing through the auxiliary magnetic pole 290, the control circuit 648 shown in FIG. The resultant vector of the armature magnetomotive force by the line 238 is controlled so as to be on the advance side in the rotation direction from the center position of the auxiliary magnetic pole, and reluctance torque is generated by the advance side phase of the rotating magnetic flux with respect to the auxiliary magnetic pole 290 of the rotor.
Since the reluctance torque is generated in the rotor 250 in the direction added to the magnet torque by the permanent magnets 254 and 256 in the start-up state and the low-speed operation state of the rotating electrical machine, the reluctance torque rotates with the addition torque of the magnet torque and the reluctance torque The required torque that the electric machine must generate can be created. Therefore, the generation of magnet torque can be reduced by the amount corresponding to the reluctance torque, and the magnetomotive force of the permanent magnet can be lowered. By lowering the magnetomotive force of the permanent magnet, it is possible to suppress the induced voltage caused by the permanent magnet during high-speed operation of the rotating electrical machine, and it becomes easy to supply power to the rotating electrical machine during high-speed rotation. Furthermore, the amount of magnets can be reduced by increasing the reluctance torque. Since rare earth permanent magnets are expensive, it is desirable from an economical viewpoint that the amount of magnets used can be reduced.
<Description of Torque Output of Rotor 250>
Magnet torque and reluctance torque will be described with reference to FIGS. 5, 6 and 7. FIGS. 5 to 7 are enlarged views of the pole portion of the rotor shown in FIG. One set of the magnets 254 and 256 constituting the poles of the rotor 250 in FIG. 4 is typically the magnets 254-1 and 256-1, and the adjacent pole set magnets are the magnets 254-2 and 256-2. As shown. 5 and 6 show the d-axis magnetic flux generated by the magnets 254-1 and 256-1, and FIG. 7 shows the q-axis magnetic flux generated by the stator 230. In addition to the magnetic fluxes shown in FIGS. 5 and 6, the d-axis magnetic flux of the rotating electric machine 200 includes a magnetic flux generated by the stator winding, which is not shown in FIGS. 5 and 6. . When the rotating electrical machine shown in FIG. 4 is in operation, both the d-axis and q-axis magnetic fluxes exist in the rotating electrical machine.
5 and 6, non-magnetic portions including magnetic gap portions 262 and 264 are formed at both ends in the circumferential direction of the permanent magnets 254 and 256 constituting each pole of the rotor 250. . Bridge portions 282 and 284 are formed in the rotor core 232 on the stator side by the magnetic gaps 262 and 264. The bridge portions 282 and 284 are magnetically saturated, and act to limit the magnetic flux leaking from the magnetic pole piece portion 280 to the auxiliary magnetic pole 290 through the bridge portions 282 and 284. By forming the bridge portions 282 and 284, changes in the magnetic flux density distribution of the permanent magnets 254 and 256 between the circumferential ends of the permanent magnets 254 and 256 and the auxiliary magnetic pole portion 290 in each pole of the rotor, that is, magnetic The change in the magnetic flux density distribution from the stator side to the stator in the gaps 262 and 264 can be moderated, and the torque pulsation of the rotating electrical machine 250 is reduced.
In the present embodiment, the magnetic gaps 262 and 264 are formed by forming a gap in the electromagnetic steel sheet, and the gap is formed integrally with a permanent magnet insertion hole for inserting a permanent magnet. In this integral formation, the magnetic gaps 262 and 264 are formed adjacent to the circumferential end of the permanent magnet 22 when the permanent magnets 254 and 256 are inserted into the permanent magnet insertion holes. The magnetic gaps 262 and 264 may be filled with a SiO-based binder that is a non-magnetic material for forming a magnet described later, or may be filled with a filler such as a varnish that is a non-magnetic material. . Of course, nothing may be filled, that is, the air gap may exist.
In this embodiment, by providing the magnetic air gaps 262 and 164, the cogging torque and other torque pulsations can be reduced as described above, and further, the magnetic air gaps 262 and 164 are formed between the magnetic pole piece portion 280-1 and the auxiliary magnetic pole portion 290. The radial dimension of the bridge portions 282 and 284 can be made smaller than the radial width of the permanent magnets 254 and 256, and leakage of magnetic flux generated by the permanent magnet can be reduced. In this embodiment, the radial dimension of the bridge portions 282 and 284 is less than half the radial width of the permanent magnets 254 and 256.
The magnetic gaps 262 and 164 have a shape in which the side on the central axis side of the rotor is shorter than the side on the stator side, in this embodiment, a trapezoidal shape. In addition, the shape between the hypotenuse side on the auxiliary magnetic pole side connecting the side on the stator side of the magnetic gap 262 or 164 and the side on the central axis side of the rotor and the side on the stator side is a predetermined curve. It has a shape. By doing so, the stress generated by the centrifugal force due to the rotation of the rotor 250 is prevented from concentrating locally. Further, it is possible to prevent the mold of a processing machine such as a press for processing the rotor core 252 from becoming an acute angle. When the processing means has an acute shape, there is a problem that the wear in the cutting process becomes severe.
The rotor core 252 can be manufactured by press-bonding iron powder instead of laminated steel sheets, and in this case, it is desirable to prevent the die of the press machine that compresses the iron powder from having an acute angle shape. When the mold has an acute angle shape, the mold of the press machine that compresses the iron powder is heavily worn. For this reason, it is desirable that the magnetic air gaps 262 and 164 have rounded corners to avoid acute angles.
The magnetic air gaps 262 and 164 may be physical air gaps, but may be filled with a material having almost no magnetic properties, such as a nonmagnetic material such as aluminum or stainless steel. For example, in the process of making the rotor core 252 by compressing iron powder, which is a magnetic material, members made in the form of magnetic gaps 262 and 164 made of aluminum or stainless steel are inserted, and these magnetic The rotor core 252 can be compression-molded by incorporating the members of the gaps 262 and 164. In this compression molding process, the rotor core 252 is compression-molded by compressing and molding the above-described magnet using the SiO-based binder and the above-described magnetic gap 262 or 164-shaped member in iron powder as a magnetic material. To manufacture.
FIG. 5 shows the magnetic flux generated by the permanent magnets 254-1 and 256-1 of the rotor 250 formed by compressing the iron powder, which is a magnetic material, as described above in a state where the stator winding 238 is not energized. Shows the flow. FIG. 6 is a diagram schematically showing the magnetic flux generated by the magnet. Magnets 254-1 and 256-1 constitute one rotor pole, and are magnetized in a direction in which the stator side of these magnets becomes an N pole. Magnetic flux generated by the magnets 254-1 and 256-1 enters the stator 230 through the pole piece 280-1. On the other hand, magnets 254-2 and 256-2 constitute the poles of the adjacent rotor, and are magnetized in the direction in which the stator side of these magnets becomes the south pole. Magnetic flux enters the magnets 254-2 and 256-2 from the stator 230 through the magnetic pole piece 280-2.
The magnetic flux shown in FIG. 6 is a d-axis magnetic flux produced by the magnet, and each circulates around the auxiliary magnetic pole 290. When a three-phase alternating current is supplied to the stator winding 238, a magnet torque is generated by the action of the magnetic flux generated by the three-phase alternating current and the d-axis magnetic flux.
FIG. 7 shows the q-axis magnetic flux among the magnetic flux generated when a three-phase alternating current is supplied to the stator winding 238. The q-axis magnetic flux passes through the auxiliary magnetic pole 290 and circulates around the permanent magnet constituting the pole. Of the magnetic fluxes generated by the stator winding 238, the q-axis magnetic flux passes through the auxiliary magnetic pole 290 and passes through a magnetic circuit that circulates the permanent magnet, so that the magnetic resistance is small and the amount of magnetic flux is large. On the other hand, among the magnetic fluxes generated by the stator winding 238, the d-axis magnetic flux passes through a magnetic circuit crossing the permanent magnet, so that the magnetic resistance is large and the amount of magnetic flux is small. A reluctance torque is generated by the magnetic flux difference between the d-axis and the q-axis.
4 to 7 show a magnet motor having an auxiliary magnetic pole 290 that generates reluctance torque. By using the reluctance torque, it is possible to reduce the amount of magnets required to satisfy the torque characteristics required for the rotating electrical machine. In addition to the effect that the internal heat generation of the magnet is reduced by reducing the amount of magnets, the induced voltage inside the rotating machine at high speed rotation can be reduced, and the supply voltage to the rotating electrical machine at high speed rotation can be kept low. However, when used as a rotating electrical machine, the above-described effect cannot be obtained. However, even if the auxiliary magnetic pole 290 is not provided, the motor operation and the generator operation can be performed as the rotating electrical machine. In this case, the structure shown in FIGS. 4 to 7 does not have the auxiliary magnetic pole 290 or has a small proportion of the auxiliary magnetic pole 290, and conversely, the proportion of the magnet increases.
<Method for Manufacturing Permanent Magnets 254 and 256>
An example of the manufacturing process of the permanent magnets 254 and 256 according to the present embodiment is shown in FIG. 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.
The rare earth magnet magnetic powder produced in step 10 has a plate-like shape, and the rare earth plate-like magnetic powder is laminated in layers by compression molding described in step 17 below. By impregnating the binder precursor described below, the binder precursor enters the narrow gaps between the laminated layers, forming a film-like binder in an amorphous state. Plate-like magnetic powder binds strongly. Therefore, good magnetic properties can be obtained.
In the present embodiment, non-oxide magnetic powder is used, and in particular, rare earth magnet, for example, magnetic powder such as NdFeB is used. In the present invention, a permanent magnet can be manufactured in a relatively low temperature step by using the method described in detail below. Thereby, even if it is a case where a non-oxide magnetic powder is used, the oxidation of a magnetic powder can be suppressed and a magnet with a high magnetic characteristic can be obtained.
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 being cooled after being heated 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. Also, it is difficult to process a curved shape by cutting, and a magnet having a curved shape cannot be easily produced. In order to manufacture a magnet having a curved shape, a method such as forming through a roller for cutting many times is used, and a lot of time and special processing equipment are required for processing.
In step 20, the compression-molded magnet molded body is impregnated with a SiO-based precursor, for example, 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 having good wettability with respect to the magnet compact, the surface of each magnetic powder constituting the magnet compact is covered with the binder, 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, the 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
Further, since the precursor described in detail below is cured at a relatively low temperature, the step 20 can be performed in a temperature range of 120 degrees to 200 degrees, particularly about 150 degrees. Thereby, the final magnet can be obtained while maintaining the size and shape of the compression molded body with high accuracy. Moreover, it can suppress that the magnetic powder for magnets, such as NdFeB, oxidizes, and can prevent the fall of a magnetic characteristic.
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 body can be obtained by binding a magnet material using SiO ₂ as a binder. As will be described in detail below, the processing temperature in step 25 is a relatively low temperature, and the shape and dimensions of the magnet compact are hardly changed by this heat treatment, and the shape and dimensions of the manufactured magnet body. The relationship maintains high accuracy with respect to the compression-molded shape and dimensions. Thereafter, the magnet body may be heated to a high temperature in order to obtain magnetically good characteristics. The temperature in this case may be lower than the sintering temperature of the conventional sintered magnet, and the shape and dimensions are maintained with higher accuracy as described above than in the case of the sintered magnet.
<Binder of permanent magnets 254 and 256>
The solution of the binder precursor used in the step 20 has an alkoxysiloxane and an alkoxysilane that are precursors of SiO ₂ , and has terminal groups and side chains as shown in Chemical Formula 2 and Chemical Formula 3. 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, and aqueous ammonia, but are not limited thereto.
The total content of alkoxysiloxane, alkoxysilane, its hydrolysis product, and its dehydration condensate, 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 4 and chemical formula 5 occurs with 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 the 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 preferable 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.
The following matters can be confirmed about the one aspect | mode of the binder of this invention demonstrated above.
First, the precursor of SiO ₂ is not a solution using an aqueous solution as a solvent but a solution using an alcohol as a solvent. Water is only added to adjust the hydrolysis reaction. By impregnating with an alcohol-based solution instead of an aqueous solution, almost no water remains after thermosetting. Since the remaining water in the permanent magnet is suppressed, the magnetic characteristics are not deteriorated over time due to oxidation or the like. On the other hand, it is considered that methoxy remains because hydrolysis is performed using alkoxysiloxane, alkoxysilane, or the like as a precursor of SiO ₂ . Therefore, it is conceivable that the manufactured permanent magnet contains magnetic powder and methoxy in addition to the binder for binding the magnetic powder.
Next, the magnet produced | generated by the said process becomes a structure which bound the rare earth magnet magnetic powders, such as NdFeB, with the SiO-type binder. This binder takes an amorphous (non-crystalline) continuous film structure. As described above, the binder is basically composed of SiO ₂ , but since it is amorphous, a composition such as SiO may partially exist. If a continuous film mainly composed of Si and O, that is, a binder composed of a SiO-based continuous film is formed, it is considered that the magnet according to the present embodiment is configured.
Next, a configuration using an oxide glass material other than SiO-based as a binder will be examined. As described above, various requirements are imposed on the precursor as the impregnation solution in order to perform the manufacturing process of the present invention. It has a low viscosity, high permeability, high stability, and curing at a relatively low temperature. It has been confirmed that the SiO-based binder is the best for satisfying these requirements, but other oxide glassy materials can be used as binders if the requirements suitable for this production process are satisfied. However, a certain degree of effect can be expected.
<Other Embodiments of Manufacturing Method of Permanent Magnets 254 and 256>
9 and 10 show another embodiment of the magnet manufacturing process according to the present invention. The embodiment of FIG. 9 is different from the process of FIG. 8 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. 10 is different in that a compression-molded magnet is attached to the rotor, and thereafter a treatment of impregnating the binder is performed. Also in the methods shown in FIGS. 9 and 10, after rare earth magnetic powder is bound with a SiO-based binder, heat treatment may be performed in order to stably maintain the magnetic properties. As described above, the heat treatment temperature is lower than the sintering temperature.
In FIG. 9, the same process numbers as those in FIG. 8 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. Since the SiO-based binder is an insulator, and in this embodiment, a thin amorphous film is formed on the surface of the plate-like magnetic powder and the magnetic powder is bound together, the rare earth magnetic powder is a conductive material. The completed magnet body has a high electrical resistance. For this reason, eddy current is suppressed, and there is an effect of improving efficiency and reducing heat generation.
As described above, according to the present embodiment, the internal resistance of the magnet body increases, but in addition to this, the surface of each powder of the magnet material is covered with an insulating layer, thereby further reducing the eddy current inside the magnet. It is possible to suppress the decrease in efficiency of the rotating machine. Moreover, the heat generation of the magnet can be further suppressed, and the heat generation of the entire rotating electrical machine can be suppressed. In particular, in the magnet built in the rotor, the rotor is mechanically connected to the housing of the rotating electrical machine via a bearing, and the heat conductivity is not good. For this reason, suppressing the heat generation of the magnet has a great effect.
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. Further, the amount of boric acid is desirably 0.05 to 0.4 g with respect to 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 of the surfactant 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 to wet the surface of the magnetic powder is insufficient, and if it exceeds 1% by weight, no further effect can be expected, which 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 diameter 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 effective concentrations and the like as processing solutions for rare earth fluoride and alkaline earth metal fluoride coating films.
In the process of FIG. 9, an insulating film is formed on the surface of each powder of the rare earth magnet material in step 12, and then the magnet material is compression molded in step 15 to form a porous magnet. Thereafter, the precursor of the binder is impregnated in step 20 as in FIG. 8, 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. 10 shows a method in which a porous magnet compression-molded before the binder impregnation step is inserted into the magnet insertion hole of the rotor, and then the binder precursor is 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 compression 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, when the temperature of the rotor itself is raised in step 27, 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.

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. The NdFeB-based master alloy is made uniform by mixing Nd with iron or an Fe-B alloy (ferroboron) and dissolving it in a vacuum, an inert gas or a reducing gas atmosphere. 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 higher and 700 ° C. or lower, and Nd ₂ Fe ₁₄ B crystallites grow by this heat treatment. The ribbon is 10 to 100 μm thick, and the crystallite size of Nd ₂ Fe ₁₄ B is 10 to 100 nm.
When the crystallites of Nd ₂ Fe ₁₄ B 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 crystallites of Nd ₂ Fe ₁₄ B 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 occurs due to 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, and the pulverized powder is inserted into a WC carbide die to which Co has been added and then compression molded with an upper and lower punch at a press pressure of 5 t-20 t / cm ^2. There are few nonmagnetic parts between magnetic particles in the direction perpendicular to the pressing direction. This is because the magnetic powder is a flat powder obtained by pulverizing a ribbon, and 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 press direction. 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, 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) CH 3 O- (Si (} CH 3 O) 2 -O) m -CH 3 (m is 3-5, average 4) 5 ml, water 0.96 ml, dehydrated methanol 95 ml, dibutyltin dilaurate 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 .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 viscosity of the SiO ₂ precursor solutions 1) to 3) was measured at a temperature of 30 ° C. using an Ostwald viscometer.
(1) The above Nd ₂ Fe ₁₄ B magnetic powder is filled into 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 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, and 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 is vacuumed against 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. 11 shows an example of the SEM observation result of the cross section of 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). FIG. 11 (a) is a secondary electron image, (b) is an oxygen surface analysis image, and (c) 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). , and the demagnetization curve was measured at 20 ° C., the values 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%) in the case of no 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 it is close to 3% in the case of the epoxy-based bond magnet (Comparative Example 1). Value. 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 containing 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 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 results are shown in FIG. Here, the demagnetization curves of the magnet impregnated under the above condition 2) and the compression molded bond magnet containing 15 vol% of an epoxy resin as a binder, which will be described later, are compared. In FIG. 12, 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 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 bond 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 the oxidation during heating in the atmosphere is prevented, and as a result, the coercive force is less likely to decrease.
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 is 30 MPa or more after the SiO ₂ impregnation heat treatment. ), 3) When the SiO ₂ precursor solution was used, it was possible to produce a magnet compact 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 into 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 properties of the present example and (Example 2) to (Example 5) described later when the binders 1) to 3) are used.

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. Also, with the following three solutions as SiO ₂ of the precursor, which is binding agent.
_{1) CH 3 O- (Si (} CH 3 O) 2 -O) m -CH 3 (m is 3-5, average 4) 25 ml, water 0.96 ml, dehydrated methanol 75 ml, dibutyltin dilaurate 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 .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 .05 ml was mixed and left at a temperature of 25 ° C. for 2 days and nights.
The viscosity of the SiO ₂ precursor solutions 1) to 3) was measured at a temperature of 30 ° C. using an Ostwald viscometer.
(1) The above Nd ₂ Fe ₁₄ B magnetic powder is filled into 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 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, and 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 is vacuumed against 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 values 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%) in the case of no SiO ₂ impregnation. Further, the irreversible thermal demagnetization factor is 1% or less after the SiO ₂ impregnation heat treatment after being kept 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 the 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 70 MPa or more after the SiO ₂ impregnation heat treatment, ₂ in this example. ), 3) When the SiO ₂ precursor solution was used, it was possible to produce a magnet compact 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 into 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.

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 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) 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 .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 6-8, average 7) a 25 ml, water 4.6 ml, dehydrated methanol 75 ml, dibutyltin dilaurate 0 .05 ml was mixed and left at a temperature of 25 ° C. for 2 days and nights.
The viscosity of the SiO ₂ precursor solutions 1) to 3) was measured at a temperature of 30 ° C. using an Ostwald viscometer.
(1) The above Nd ₂ Fe ₁₄ B magnetic powder is filled into 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 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, and 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 is vacuumed against 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 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 in the atmosphere at 200 degrees Celsius 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 factor is 1% or less after the SiO ₂ impregnation heat treatment after being kept 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 the 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 the 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 into 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.

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 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₎ a _{C 2 H 5 O- (Si (} C 2 H 5 O) 2 -O) -CH 3 25ml, water 4.3 ml, dehydrated ethyl alcohol 75 ml, and dibutyltin dilaurate 0.05 ml, 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 .05 ml was mixed and left at a temperature of 25 ° C. for 6 days and nights.
The viscosity of the SiO ₂ precursor solutions 1) to 3) was measured at a temperature of 30 ° C. using an Ostwald viscometer.
(1) The above Nd ₂ Fe ₁₄ B magnetic powder is filled into 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 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, and 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 is vacuumed against 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 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 in the atmosphere at 200 degrees Celsius 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 is 1% or less after the SiO ₂ impregnation heat treatment after being kept in the atmosphere at 200 ° C. for 1 hour, and 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 the 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 the 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 into 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.

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 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 .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 .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 .05 ml was mixed and left at a temperature of 25 ° C. for 4 days and nights.
The viscosity of the SiO ₂ precursor solutions 1) to 3) was measured at a temperature of 30 ° C. using an Ostwald viscometer.
(1) The above Nd ₂ Fe ₁₄ B magnetic powder is filled into 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 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, and 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 is vacuumed against 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 for 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%) in the case of no SiO ₂ impregnation. Further, the irreversible thermal demagnetization factor is 1% or less after the SiO ₂ impregnation heat treatment after being kept 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 the 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 into 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.

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 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 the gel-like LaF ₃ was formed was stirred for 1 hour or more using an ultrasonic stirrer.
(4) 4000-6000 r. p. After centrifugation at a rotational speed of m, the supernatant was removed and approximately the same amount of methanol was added.
(5) A methanol solution containing gel-like LaF ₃ was stirred to form 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 used are summarized in Table 3.
The process of forming a 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 forming process: NdF ₃ concentration 1 g / 10 ml translucent sol solution (1) To 100 g of magnetic powder obtained by pulverizing NdFeB-based ribbon, 15 ml of NdF ₃ coat film forming treatment solution is added, The mixing was performed until it was confirmed that the entire magnetic powder for rare earth magnet was wet.
(2) The methanol of the solvent was removed from the magnetic powder for rare-earth magnet subjected to the NdF ₃ coat film forming process of (1) under a reduced pressure of 2 to 5 torr.
(3) The rare earth magnet magnetic powder from which the solvent of (2) was removed was transferred to a quartz boat and heat-treated at 200 ° C. for 30 minutes and at 400 ° C. for 30 minutes under a reduced pressure of 1 × 10 ⁻⁵ torr. .
(4) After the magnetic powder heat-treated in (3) is transferred to a lid made by Macor (manufactured by Riken Denshi Co., Ltd.), it is heat-treated at 700 ° C. for 30 minutes under a reduced pressure of 1 × 10 ⁻⁵ torr. It was.
The SiO ₂ precursor as a binder includes 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, and dehydration. A solution in which 75 ml of methyl alcohol and 0.05 ml of dibutyltin dilaurate were mixed and left at a temperature of 25 ° C. for 2 days was used.
(1) A magnetic powder of Nd ₂ Fe ₁₄ B 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 10 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 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 the 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, and 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 (5) above.
(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 produced in the above (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 for 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%) in the case of no SiO ₂ impregnation. Further, the irreversible thermal demagnetization factor is 1% or less after the SiO ₂ impregnation heat treatment after being kept 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 the magnetic powder.
A magnet using a rare earth magnetic powder formed with a rare earth fluoride or alkaline earth metal fluoride coating film of this example not only functions as an insulating film described later, but also uses TbF ₃ and DyF ₃ and PrF, although less effective. _{When 3} was used for coating film formation, it was found that it 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 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 the value of the magnet of the present invention compared to 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 into 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. 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 highly reliable. In addition, TbF ₃ and DyF ₃ can be coated. It was found that the magnetic properties can be greatly improved when used for formation.

In this example, a magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Example 1] was used. The process of forming a 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 formation 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) The methanol of the solvent was removed from the magnetic powder for a rare earth magnet subjected to the PrF ₃ coat film formation 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 at 400 ° C. for 30 minutes under a reduced pressure of 1 × 10 ⁻⁵ torr. It was.
(4) The magnetic powder heat-treated in (3) above is transferred to a lid made by Macor (manufactured by Riken Denshi Co., Ltd.), and then subjected to heat treatment at 700 ° C. for 30 minutes under a reduced pressure of 1 × 10 ⁻⁵ torr. went.
The SiO ₂ precursor as a binder includes 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, and dehydration. A solution in which 75 ml of methyl alcohol and 0.05 ml of dibutyltin dilaurate were mixed and left at a temperature of 25 ° C. for 2 days was used.
(1) Nd ₂ Fe ₁₄ B magnetic powder coated with the 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. Further, 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 the 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, and 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 (5) above.
(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 produced in the above (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 for 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%) in the case of no SiO ₂ impregnation. Further, the irreversible thermal demagnetization factor is 1% or less after the SiO ₂ impregnation heat treatment after being kept 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 the 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 the value of the magnet of the present invention compared to the sintered type rare earth magnet, and the same value as that of the compression 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 into 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. 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 made highly reliable, and PrF ₃ is used for forming the coat 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 magnetic properties, bending strength and reliability as a whole.

In this example, a magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Example 1] was used. The process of forming a 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 translucent sol solution was used.
(1) 10 ml of DyF ₃ coat film forming treatment liquid was added to 100 g of magnetic powder obtained by pulverizing NdFeB-based ribbons, and mixed until it was confirmed that the entire magnetic powder for rare earth magnets was wet.
(2) The methanol of the solvent was removed from the rare earth magnet magnetic powder 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 at 400 ° C. for 30 minutes under a reduced pressure of 1 × 10 ⁻⁵ torr. It was.
(4) The magnetic powder heat-treated in (3) above is transferred to a lid made by Macor (manufactured by Riken Denshi Co., Ltd.), and then subjected to heat treatment at 700 ° C. for 30 minutes under a reduced pressure of 1 × 10 ⁻⁵ torr. went.
The SiO ₂ precursor as a binder includes 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, and dehydration. A solution in which 75 ml of methyl alcohol and 0.05 ml of dibutyltin dilaurate were mixed and left at a temperature of 25 ° C. for 2 days 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 Further, 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 the 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, and 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 (5) above.
(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 produced in the above (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 for 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%) in the case of no SiO ₂ impregnation. Further, the irreversible thermal demagnetization factor is 1% or less after the SiO ₂ impregnation heat treatment after being kept 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 the magnetic powder.
It was found that the magnet using the rare earth magnetic powder formed with the DyF ₃ coat film of this example not only functions as an insulating film described later, but can contribute to 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 into 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. 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 highly reliable. In addition, TbF ₃ and DyF ₃ can be coated. It was found that the magnetic properties can be greatly improved when used for formation.

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, ZnO, CdO, CaO or BaO are dissolved in 1 l of water, and EF-104 (manufactured by Tochem Products), EF-122 (Tochem Products) are dissolved as surfactants. EF-132 (manufactured by Tochem Products) was added to a concentration of 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 Nd ₂ Fe ₁₄ B magnetic powder 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 a 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 as a binder includes 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, and dehydration. A solution in which 75 ml of methyl alcohol and 0.05 ml of dibutyltin dilaurate were mixed and left at a temperature of 25 ° C. for 2 days was used.
(1) Nd ₂ Fe ₁₄ B magnetic powder subjected to the above phosphatization film formation treatment is filled in a mold, and is 10 mm long, 10 mm wide and 5 mm thick for measuring magnetic properties at a pressure of 16 t / cm ^2. Further, 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 the 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, and 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 (5) above.
(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 produced in the above (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 values 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%) in the case of no SiO ₂ impregnation. Further, the irreversible thermal demagnetization factor is 1% or less after the SiO ₂ impregnation heat treatment after being kept 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 the 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 the value of the magnet of the present invention compared to 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 into 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.

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 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 Nd ₂ Fe ₁₄ B magnetic powder 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) was heat-treated at 180 ° C. for 30 minutes under a reduced pressure of 2 to 5 torr.
The SiO ₂ precursor as a binder includes 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, and dehydration. A solution in which 75 ml of methyl alcohol and 0.05 ml of dibutyltin dilaurate were mixed and left at a temperature of 25 ° C. for 2 days was used.
(1) Nd ₂ Fe ₁₄ B magnetic powder subjected to the above phosphatization film formation treatment is filled in a mold, and is 10 mm long, 10 mm wide and 5 mm thick for measuring magnetic properties at a pressure of 16 t / cm ^2. Further, 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 the 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, and 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 (5) above.
(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 produced in the above (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 for 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%) in the case of no SiO ₂ impregnation. Further, the irreversible thermal demagnetization factor is 1% or less after the SiO ₂ impregnation heat treatment after being kept 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 the 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 the value of the magnet of the present invention compared to 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 into 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.

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) was used as a surfactant, and the concentration was 0.01 to 1 wt%. The process of forming the phosphate chemical conversion film on the Nd ₂ Fe ₁₄ B magnetic powder 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 wet.
(2) The magnetic powder for a rare earth magnet subjected to the phosphating film forming process of (1) was heat-treated at 180 ° C. for 30 minutes under a reduced pressure of 2 to 5 torr.
The SiO ₂ precursor as a binder includes 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, and dehydration. A solution in which 75 ml of methyl alcohol and 0.05 ml of dibutyltin dilaurate were mixed and left at a temperature of 25 ° C. for 2 days was used.
(1) Nd ₂ Fe ₁₄ B magnetic powder subjected to the above phosphatization film formation treatment is filled in a mold, and is 10 mm long, 10 mm wide and 5 mm thick for measuring magnetic properties at a pressure of 16 t / cm ^2. Further, 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 the 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. did.
(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 (5) above.
(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 produced in the above (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 values 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%) in the case of no SiO ₂ impregnation. Further, the irreversible thermal demagnetization factor is 1% or less after the SiO ₂ impregnation heat treatment after being kept 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 the 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 the value of the magnet of the present invention compared to 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 into 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.

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. Dissolve 20 g of phosphoric acid, 4 g of boric acid and 4 g of MgO as a metal oxide in 1 liter of water, 0.1 wt% of EF-104 (manufactured by Tochem Products) as a surfactant, and 0.1% of benzotriazole (BT) as a rust inhibitor. It added so that it might become 04 mol / l. The phosphate chemical conversion treatment film is made of the above Nd ₂ Fe ₁₄ The process for forming B magnetic powder was carried out by the following method.
(1) 2.5 to 30 ml of a phosphatizing 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 process of (1) was heat-treated at 180 ° C. for 30 minutes under a reduced pressure of 2 to 5 torr.
SiO as a binder ₂ The precursor is CH ₃ O- (Si (CH ₃ O) ₂ -O) _m -CH ₃ (M is 3-5, average is 4) 25 ml, water 4.8 ml, dehydrated methyl alcohol 75 ml, dibutyltin dilaurate 0.05 ml were mixed and used at room temperature for 2 days and nights.
(1) Nd subjected to the phosphating film formation process ₂ Fe ₁₄ Fill the mold with B magnetic powder, 16t / cm ² A test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm was measured for measuring magnetic characteristics, and 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) SiO, which is a binder that is placed in a bat so that the compression direction is the horizontal direction and the compression molding test piece prepared in (1) is left at a temperature of 25 ° C. for two days and nights. ₂ The precursor solution was injected into the vat so that the liquid level was 1 mm / min in the vertical direction. It is SiO until it finally becomes 5mm above the upper surface of the compression molding test piece. ₂ The precursor solution was injected into the vat.
(3) The compression molded test piece used in (2) above is placed and SiO ₂ The vat filled with the 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) Compression molding test piece is placed and SiO ₂ The internal pressure of the vacuum vessel in which the bat filled with the precursor solution is set is gradually returned to the atmospheric pressure, and the compression molded specimen is made of SiO. ₂ Removed from within the precursor solution.
(5) SiO prepared in (4) above ₂ The compression molding test piece impregnated with the precursor solution was set in a vacuum drying furnace, and the compression molding test piece was subjected to vacuum heat treatment under the conditions of 1 to 3 Pa and 150 ° C.
(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 (5) above.
(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 produced in the above (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 for 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). The demagnetization curve measured at 20 ° C. is SiO 2 ₂ Before impregnation and SiO ₂ The values of residual magnetic flux density and coercive force almost coincided with the molded body after the impregnation heat treatment. Moreover, the thermal demagnetization factor after 1 hour holding at 200 ° C. in the atmosphere is SiO ₂ Impregnated bonded magnet is 3.0% and SiO ₂ It is smaller than the thermal demagnetization factor (5%) when there is no impregnation. Furthermore, the irreversible thermal demagnetization rate is also kept at 200 ° C. in the atmosphere for 1 hour, and then SiO 2 ₂ Less than 1% after impregnation heat treatment and SiO ₂ It is smaller than the value close to 3% without impregnation. This is SiO ₂ This is because deterioration due to oxidation of magnetic powder is suppressed. 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) is SiO. ₂ It is 2 MPa or less before impregnation, but SiO ₂ After the impregnation heat treatment, it was possible to produce a magnet molded body having a bending strength of 100 MPa or more.
Further, the specific resistance of the magnet is about 100 times or more the value of the magnet of the present invention compared to 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 low-viscosity SiO of the present invention. ₂ The rare earth bonded magnet impregnated into the rare earth magnet molded body prepared by cold forming without using the resin as a precursor has a magnetic property of 20 to 30% and a bending strength of about 20% compared to a normal resin-containing rare earth bonded magnet. It was found that the irreversible thermal demagnetization factor can be reduced to three times or less and the reliability of the magnet can be increased.
(Comparative Example 1)
In this comparative example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Example 1] was used for 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 compound of rare earth magnet magnetic powder and resin prepared in (1) above is loaded into a mold, and the molding pressure is 16 t / cm in an inert gas atmosphere. ² Under the conditions of 80 ° C., heat compression molding was performed. 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 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 (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 the above (3). 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 characteristics of 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) were examined. As a result, the residual magnetic flux density of the magnet decreased as the epoxy resin content in the magnet increased. SiO ₂ Compared with bonded magnets (Examples 1 to 5) produced by impregnating the binder, the epoxy resin-containing bonded magnet has a magnetic flux density reduced by 20 to 30% when compared with a magnet having a bending strength of 50 MPa or more. Was. In addition, the thermal demagnetization rate after 1 hour of holding at 200 ° C. in the atmosphere is 5% for the epoxy resin-containing bond magnet and SiO 2 ₂ Large compared to 3.0% of impregnated bonded magnets. 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 impregnated (Examples 1 to 5), whereas the bonded magnet containing an epoxy resin In the case of (Comparative Example 1), the value was close to 3%. In addition to the suppression of irreversible thermal demagnetization, bonded resin magnets containing epoxy resin are also used in PCT tests and salt spray tests. ₂ The level was lower than that of the impregnated bonded magnet.
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 kept 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 results are shown in FIG. In FIG. 4, SiO under the conditions of 2) of (Example 1). ₂ A demagnetization curve is compared between the magnet impregnated with the above and a compression-bonded magnet containing 15 vol% of an epoxy resin as a binder as shown in this comparative example. In FIG. 4, the horizontal axis represents the applied magnetic field, and the vertical axis represents the magnetic flux density. SiO ₂ In a magnet impregnated with a 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 bond 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. In contrast, in the impregnated magnet, the NdFeB powder and the crack surface are SiO. ₂ It is considered that the decrease in coercive force is small as a result of preventing oxidation during heating in the air because it is covered with a film.
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, and the volume content is 20 vol%. The bending strength of the magnet is 48 MPa, which is necessary for a bonded magnet. Epoxy resin-containing bonded magnet is made of SiO. ₂ Compared with the impregnated bonded magnet, the specific resistance was on the same level.
From the result of this comparative example, the epoxy resin-containing rare earth bonded magnet is the low-viscosity SiO of the present invention. ₂ Compared with rare earth bonded magnets impregnated into a rare earth magnet molded body prepared by cold forming without using a resin, the magnetic properties are 20-30% lower, the irreversible thermal demagnetization rate and the reliability of the magnet are low. It has been found.
In addition, in this comparative example, the evaluation result of the epoxy resin containing bonded 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)
In this comparative example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Example 1] was used for the rare earth magnet magnetic powder.
SiO as a binder ₂ The precursor includes CH ₃ O- (Si (CH ₃ O) ₂ -O) _m -CH ₃ (M is 3 to 5, average is 4) 1 ml, water 0.19 ml, dehydrated methyl alcohol 99 ml, and dibutyltin dilaurate 0.05 ml were mixed, and a solution that was allowed to stand at 25 ° C. for 2 days and nights was used.
SiO ₂ The viscosity of the precursor solution was measured at a temperature of 30 ° C. using an Ostwald viscometer.
(1) Nd ₂ Fe ₁₄ Fill the mold with B magnetic powder, 16t / cm ² A test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm was measured for measuring magnetic characteristics, and 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 compression molded test piece prepared in (1) above is placed in the bat so that the pressing direction is horizontal, and the SiO as a binder is added. ₂ The precursor solution was injected into the vat so that the liquid level was 1 mm / min in the vertical direction. It is SiO until it finally becomes 5mm above the upper surface of the compression molding test piece. ₂ The precursor solution was injected into the vat.
(3) The compression molded test piece used in (2) above is placed and SiO ₂ The vat filled with the 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) Compression molding test piece is placed and SiO ₂ The internal pressure of the vacuum vessel in which the bat filled with the precursor solution is set is gradually returned to the atmospheric pressure, and the compression molded specimen is made of SiO. ₂ Removed from within the precursor solution.
(5) SiO prepared in (4) above ₂ The compression molding test piece impregnated with the precursor solution was set in a vacuum drying furnace, and the compression molding test piece was subjected to vacuum heat treatment under the conditions of 1 to 3 Pa and 150 ° C.
(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 (5) above.
(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 produced in the above (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 for 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). The demagnetization curve measured at 20 ° C. is SiO 2 ₂ Before impregnation and SiO ₂ The values of residual magnetic flux density and coercive force almost coincided with the molded body after the impregnation heat treatment. Moreover, the thermal demagnetization factor after 1 hour holding in the atmosphere at 200 ° C. is SiO ₂ Impregnated bonded magnet is 3.0% and SiO ₂ It is smaller than the thermal demagnetization factor (5%) when there is no impregnation. Further, the irreversible thermal demagnetization rate after returning to room temperature after 1 hour at 200 ° C. and re-magnetization was less than 1% when the impregnation treatment was performed, whereas it was close to 3% in the case of the epoxy-based bond magnet. (Comparative Example 1).
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 the above (7) is a low level value, and the SiO 2 of this comparative example is low. ₂ The impregnated bonded magnet was only about 1/10 of the epoxy resin-containing bonded magnet. This is the SiO in the binder in this comparative example. ₂ The content of the precursor is 1 vol% and SiO in the binder in the examples. ₂ Compared to the precursor content, it is 1 to 2 orders of magnitude less, so the cured SiO ₂ Even if the bending strength of a single substance is large, the fact that the content in the magnet is too small has an influence.
In conclusion, the magnet of this comparative example has a disadvantage that the magnet strength is low, and it is necessary to consider the bending strength depending on the object of use.
The various characteristics of this comparative example and 1), 2), and (Comparative Example 4) of (Comparative Example 3) described later are summarized in Table 6.
(Comparative Example 3)
In this comparative example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Example 1] was used for the rare earth magnet magnetic powder.
SiO as a binder ₂ The following two solutions were used as precursors.
1) CH ₃ O- (Si (CH ₃ O) ₂ -O) _m -CH ₃ (M is 3-5, average is 4) 25 ml, water 0.19 ml, dehydrated methyl alcohol 75 ml, and dibutyltin dilaurate 0.05 ml were mixed and allowed to stand at a temperature of 25 ° C. for 2 days.
2) CH ₃ O- (Si (CH ₃ O) ₂ -O) _m -CH ₃ (M is 3-5, average is 4) 25 ml, water 24 ml, dehydrated ethyl alcohol 75 ml, dibutyltin dilaurate 0.05 ml were mixed and left at a temperature of 25 ° C. for 2 days and nights.
SiO of 1) and 2) ₂ The viscosity of the precursor solution was measured at a temperature of 30 ° C. using an Ostwald viscometer.
(1) Nd ₂ Fe ₁₄ Fill the mold with B magnetic powder, 16t / cm ² A test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm was measured for measuring magnetic characteristics, and 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 compression molded test piece prepared in (1) above is placed in the bat so that the pressing direction is horizontal, and the SiO 1) and 2) which are binders ₂ The precursor solution was injected into the vat so that the liquid level was 1 mm / min in the vertical direction. It is SiO until it finally becomes 5mm above the upper surface of the compression molding test piece. ₂ The precursor solution was injected into the vat.
(3) The compression molded test piece used in (2) above is placed and SiO ₂ The vat filled with the 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) Compression molding test piece is placed and SiO ₂ The internal pressure of the vacuum vessel in which the bat filled with the precursor solution is set is gradually returned to the atmospheric pressure, and the compression molded specimen is made of SiO. ₂ Removed from within the precursor solution.
(5) SiO prepared in (4) above ₂ The compression molding test piece impregnated with the precursor solution was set in a vacuum drying furnace, and the compression molding test piece was subjected to vacuum heat treatment under the conditions of 1 to 3 Pa and 150 ° C.
(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 (5) above.
(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 produced in the above (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 (1) of (Comparative Example 3), the residual magnetic flux density is a resin-containing bond magnet (Comparative Example 1) with respect to the magnetic properties of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (5) above. 20-30% improvement, and the demagnetization curve measured at 20 ° C. is SiO 2 ₂ Before impregnation and SiO ₂ The values of residual magnetic flux density and coercive force almost coincided with the molded body after the impregnation heat treatment. Moreover, the thermal demagnetization factor after 1 hour holding in the atmosphere at 200 ° C. is SiO ₂ Impregnated bonded magnet is 3.0% and SiO ₂ It is smaller than the thermal demagnetization factor (5%) when there is no impregnation. Furthermore, the irreversible 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 3% in the case of an epoxy bond magnet (Comparative Example 1). It was close.
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 the above (7) is a low level value, and the SiO 2 of this comparative example is low. ₂ The impregnated bonded magnet was only about 1/6 of the value compared to the epoxy resin-containing bonded magnet. This is because the addition amount of water in the binder in this comparative example is small, and SiO shown in Chemical Reaction Formula 1 ₂ Silanol groups are not generated because hydrolysis of methoxy groups in the precursor material does not proceed, and SiO ₂ Since there is no dehydration condensation reaction between silanol groups in the thermosetting reaction of the precursor, SiO after heat curing ₂ The production amount of SiO is small ₂ This is because the bending strength of the impregnated bonded magnet was low.
In conclusion, since the magnet of 1) of (Comparative Example 3) has a low magnet strength, it is desirable to use it in consideration of the relationship of the magnet strength in the object of use.
Regarding (2) of (Comparative Example 3), 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 prepared in (7) is SiO. ₂ It is 2 MPa or less before impregnation, but 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 for 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% compared to the resin-containing bond magnet (Comparative Example 1). The demagnetization curve measured at 20 ° C. is SiO ₂ Before impregnation and SiO ₂ The values of residual magnetic flux density and coercive force almost coincided with the molded body after the impregnation heat treatment. However, the thermal demagnetization factor after 1 hour of holding at 200 ° C. in the atmosphere is 4.0% in this comparative example, which is SiO in the example. ₂ It was a large value compared with 3.0% for the impregnated bonded magnet. Furthermore, the irreversible thermal demagnetization rate after returning to room temperature after 1 hour at 200 ° C. and re-magnetization is the SiO 2 in the example. ₂ In the case of the impregnation treatment, the value was less than 1%, whereas in this comparative example, the value was close to 2%. This is SiO ₂ It was found that the effect was that the 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 deterioration 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)
In this comparative example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Example 1] was used for the rare earth magnet magnetic powder. SiO as a binder ₂ The precursor is CH ₃ O- (Si (CH ₃ O) ₂ -O) _m -CH ₃ (M is 3-5, average is 4) 25 ml, water 9.6 ml, dehydrated methyl alcohol 75 ml, dibutyltin dilaurate 0.05 ml were mixed and used for 6 days and nights at a temperature of 25 ° C.
SiO ₂ The viscosity of the precursor solution was measured at a temperature of 30 ° C. using an Ostwald viscometer.
(1) Nd ₂ Fe ₁₄ Fill the mold with B magnetic powder, 16t / cm ² A test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm was measured for measuring magnetic characteristics, and 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 compression molded test piece prepared in (1) above is placed in the bat so that the pressing direction is horizontal, and the SiO as a binder is added. ₂ The precursor solution was injected into the vat so that the liquid level was 1 mm / min in the vertical direction. It is SiO until it finally becomes 5mm above the upper surface of the compression molding test piece. ₂ The precursor solution was injected into the vat.
(3) The compression molded test piece used in (2) above is placed and SiO ₂ The vat filled with the 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) Compression molding test piece is placed and SiO ₂ The internal pressure of the vacuum vessel in which the bat filled with the precursor solution is set is gradually returned to the atmospheric pressure, and the compression molded specimen is made of SiO. ₂ Removed from within the precursor solution.
(5) SiO prepared in (4) above ₂ The compression molding test piece impregnated with the precursor solution was set in a vacuum drying furnace, and the compression molding test piece was subjected to vacuum heat treatment under the conditions of 1 to 3 Pa and 150 ° C.
(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 (5) above.
(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 produced in the above (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.
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) is SiO. ₂ It is 2 MPa or less before impregnation, but SiO ₂ After the impregnation heat treatment, it was possible to produce a magnet compact having a bending strength of 190 MPa.
Regarding the magnetic characteristics for 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). Yes, the demagnetization curve measured at 20 ° C is SiO ₂ Before impregnation and SiO ₂ The values of residual magnetic flux density and coercive force almost coincided with the molded body after the impregnation heat treatment. However, the thermal demagnetization factor after 1 hour of holding at 200 ° C. in the atmosphere is 3.6% in this comparative example, which is SiO in the example. ₂ It was a large value compared with 3.0% for the impregnated bonded magnet. Furthermore, the irreversible thermal demagnetization rate after returning to room temperature after 1 hour at 200 ° C. and re-magnetization is the SiO 2 in the example. ₂ Whereas the impregnation treatment was less than 1%, the value was 1.6% in this comparative example. This is SiO ₂ It was found that the effect was that the 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 deterioration 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)
In this comparative example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Example 1] was used for 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, 4 g of Nd acetate or Nd nitrate was introduced into 100 ml of water, and completely dissolved using a shaker or an ultrasonic stirrer.
(2) Hydrofluoric acid diluted to 10% is NdF ₃ The equivalent amount of the chemical reaction that produces was gradually added.
(3) NdF of gel-like precipitate ₃ The resulting solution was stirred for 1 hour or more using an ultrasonic stirrer.
(4) 4000-6000 r. p. After centrifugation at a rotational speed of m, the supernatant was removed and approximately the same amount of methanol was added.
(5) Gel NdF ₃ The methanol solution containing was stirred to make 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 NdF ₃ In the case of almost transparent sol-like NdF ₃ It became. NdF as processing solution ₃ Used a 1 g / 5 ml methanol solution.
A rare earth fluoride or alkaline earth metal fluoride coating film is formed on the Nd ₂ Fe ₁₄ The process for forming B magnetic powder was carried out by the following method.
NdF ₃ For coating film formation process: NdF ₃ Concentration 1g / 10ml translucent sol solution
(1) 15 ml of NdF with respect to 100 g of magnetic powder obtained by grinding NdFeB-based ribbons ₃ The coating film forming treatment liquid was added and mixed until it was confirmed that the entire magnetic powder for rare earth magnet was wet.
(2) NdF of (1) above ₃ The methanol powder of the rare earth magnet subjected to the coating film formation treatment was removed with methanol 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 1 × 10 ^-5 Heat treatment was performed at 200 ° C. for 30 minutes and 400 ° C. for 30 minutes under reduced pressure of torr.
(4) After the magnetic powder heat-treated in (3) above is transferred to a lid made by Macor (made by Riken Denshi Co.), 1 × 10 ^-5 Heat treatment was performed at 700 ° C. for 30 minutes under a reduced pressure of torr.
(5) Nd coated with the rare earth fluoride or alkaline earth metal fluoride coating film ₂ Fe ₁₄ Fill the mold with B magnetic powder, 16t / cm ² A test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm was measured for measuring magnetic characteristics, and 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.
(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 (5) above.
(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 produced in the above (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 can be improved by about 20% compared to the resin-containing bond magnet (Comparative Example 1). The demagnetization curve measured at 20 ° C. is SiO ₂ Before impregnation and SiO ₂ The values of residual magnetic flux density and coercive force almost coincided with the molded body after the impregnation heat treatment. In addition, the thermal demagnetization factor after 1 hour of holding in the atmosphere at 200 ° C. is 3.0% in this comparative example, which is SiO in the example. ₂ With the impregnated bonded magnet, the value was equivalent to 3.0%. Furthermore, the irreversible thermal demagnetization rate after returning to room temperature after 1 hour at 200 ° C. and re-magnetization is the SiO 2 in the example. ₂ In the case of the impregnation treatment, the value was less than 1%, whereas in this comparative example, the value was less than 1%. The results are shown in Table 7.
However, regarding the bending strength of the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (7), in this comparative example, SiO 2 ₂ Since impregnation was not performed, the value was 2.9 MPa, which was about 1/15 compared to the epoxy-based bonded 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)
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. 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) was added as a surfactant to a concentration of 0.1 wt%. As a rust inhibitor, benzotriazole (BT) was added so as to be 0.04 mol / l.
The phosphate chemical conversion treatment film is made of the above Nd ₂ Fe ₁₄ The process for forming B magnetic powder 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) was heat-treated at 180 ° C. for 30 minutes under a reduced pressure of 2 to 5 torr.
(3) Nd subjected to the phosphating film formation process ₂ Fe ₁₄ Fill the mold with B magnetic powder, 16t / cm ² A test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm was measured for measuring magnetic characteristics, and 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 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 (3) above.
(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 prepared in the above (3). 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 (3), the residual magnetic flux density can be improved by about 25% compared to the resin-containing bond magnet (Comparative Example 1). Yes, the demagnetization curve measured at 20 ° C is SiO ₂ Before impregnation and SiO ₂ The values of residual magnetic flux density and coercive force almost coincided with the molded body after the impregnation heat treatment. Further, the thermal demagnetization factor after 1 hour of holding at 200 ° C. in the atmosphere is 3.1% in this comparative example, and SiO in the example. ₂ The value was almost equivalent to 3.0% for the impregnated bonded magnet. Furthermore, the irreversible thermal demagnetization rate after returning to room temperature after 1 hour at 200 ° C. and re-magnetization is the SiO 2 in the example. ₂ In the case of the impregnation treatment, the value was less than 1%, but in this comparative example, the value was 1.2%, which was slightly increased (Table 7). However, regarding 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), in this comparative example, SiO 2 ₂ Since impregnation was not performed, the value was 2.9 MPa, which was about 1/20 of that of an epoxy 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 a 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, SiO ₂ Therefore, it is necessary to control the hydrolysis amount of the alkoxy group 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, SiO ₂ The viscosity of the alkoxysiloxane solution, which is the precursor of, 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. As the solvent alcohol, methanol, ethanol, n-propanol, and iso-propanol having a lower boiling point than water and a low viscosity are preferable, but the viscosity of the binder solution does not increase in several hours and the boiling point is lower than that of water. If it is, it can be used for manufacture of the magnet according to the present invention.
Regarding the adhesion between the cured binder and the magnetic powder, SiO, which is the binder used in the present invention, is used. ₂ As for the precursor, the product after heat treatment is SiO ₂ Therefore, if the magnetic powder surface is covered with a natural oxide film, the magnetic powder surface and SiO ₂ Adhesion with SiO ₂ For rare earth magnets with a binder, the surface when the magnet is broken is magnetic powder or SiO ₂ Most of the cohesive failure surface. On the other hand, when a resin is used as the binder, the adhesion between the resin and the magnetic powder is such that the surface of the magnetic powder and SiO ₂ Is generally smaller than 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, to improve the magnet strength, SiO ₂ It is more advantageous to use as a binder than to use a resin as a binder.
When the content of the rare earth magnetic powder in the magnet is 75 vol% or more, a compression molding 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 using a resin such as an epoxy resin, 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, SiO ₂ Since the precursor has good wettability with rare earth magnetic powder, SiO ₂ The precursor spreads continuously, and is cured by heat treatment in the continuously spread state. ₂ become. On the other hand, the strength of the binder after curing is expressed as SiO ₂ Is 1 to 3 orders of magnitude larger than that of resin. Therefore, the strength of the rare earth magnet after curing the binder is ₂ Using the precursor is orders of magnitude higher than using the resin.
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 magnet, the main phase is 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. Examples of the rare earth magnet powder include Sm—Co magnets in addition to Nd—Fe—B magnets. 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. If the average particle diameter 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 deteriorate. 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 (in Nd-Fe-B magnets, Nd ₂ Fe ₁₄ 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. The main phase is Nd ₂ Fe ₁₄ When producing an Nd-Fe-B magnet that is a B phase, Nd, Fe, and B are mixed in a predetermined amount. 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 addition, HDDR method is Nd which is a main phase by hydrogenating a Nd-Fe-B type alloy. ₂ Fe ₁₄ Compound B is NdH ₃ , Α-Fe, and Fe ₂ B is decomposed into three phases and then again Nd by forced dehydrogenation. ₂ Fe ₁₄ This is a technique for generating B. 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, 1 × 10 of the magnetic powder on which the fluoride coat film is formed is used. ^-4 It is desirable to perform heat treatment in an atmosphere of Pa or lower and a temperature of 600 to 700 ° C.
<Effect of rotating electrical machine with the above structure>
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, the powder magnet material and the binder precursor having good wettability are magnets. By manufacturing the magnet by impregnating with, it has at least one or more of the following effects. As described above, as a binder for a powder magnet material and a precursor with good wettability, SiO ₂ Is the best.
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 magnetic characteristic of a magnet is superior to a bond magnet, and it can be cheap and can obtain the rotary electric machine of a comparatively favorable characteristic.
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. That is, the cutting work after binding the magnet material with the binder is very little and easy. For example, it is not a substantial magnet-shaped forming process such as cutting the protruding part 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.
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.
<Other embodiments of rotating electrical machine>
FIG. 13 shows another embodiment relating to the rotating electrical machines 200 and 202 described in FIGS. Each of these rotating electric machines 200 and 202 is formed by compression molding iron powder by a fixed 230 or a rotor 250. The structure and operation of the stator 230 are the same as those of the stator 230 of the rotating electrical machines 200 and 202 described with reference to FIGS.
As described above, the stator core 232 of the stator 230 is formed by compressing iron powder having an electric insulating film on the surface. First, the stator winding is molded, the stator winding is temporarily fixed, the iron winding is filled so that the temporarily fixed stator winding is built in, and then the entire iron powder is compression-molded to form the entire stator. Can be made and productivity is improved. In some cases, the space factor of the stator winding can be further improved. The electrical insulation film on the surface of the iron powder increases the electrical resistance in the stator core, thereby reducing eddy currents in the stator core, reducing heat generation and improving the efficiency of the rotating electrical machine.
The rotor core 252 can also reduce the eddy current of the rotor core 250 by compressing and molding the iron powder that has been subjected to the process of attaching an electrical insulating film to the surface. Further, as described above, the permanent magnets 254 and 256 have a structure that reduces eddy currents, so that the internal heat generation of the rotor 250 can be reduced comprehensively. Rare earth permanent magnets have the disadvantage that their magnetic properties deteriorate, that is, demagnetize when the temperature rises. In-vehicle rotating electrical machines are often used in situations where the ambient temperature is high, and reducing internal heat generation can prevent the deterioration of the magnetic properties of the magnet, reducing various obstacles caused by heat and reliability. It is very preferable for maintaining a high value.
The permanent magnets 254 and 256 provided on the rotor 250 shown in FIG. 13 are basically the same as the permanent magnets 254 and 256 described in FIGS. 3 to 6, but the magnet shape is different. Along with this, the action is slightly different. In FIG. 13, the permanent magnets 254 and 256 have an integral shape, and at least the stator side has a curved shape. At both ends of the permanent magnets 254 and 256, the radial thickness of the magnet is thinner than that of the central portion. As a result, the magnetomotive force of the permanent magnet at the central portion of the magnetic pole of the rotor 250 is larger than the magnetomotive force of the permanent magnet at the magnetic pole end, and the thickness in the diameter direction of the permanent magnets 254 and 256 changes gently. The magnetomotive force changes smoothly. As described below, there is an effect of smoothing the torque and electromotive force of the rotating electrical machine.
The thickness in the radial direction of the magnetic pole piece 280 located on the rotor side of the permanent magnets 254 and 256 is thinner than that described in FIG. With this structure, the magnetic circuit between the magnetic pole piece 280 and the auxiliary magnetic pole 290 is in a temporally saturated state, and the amount of magnetic flux is suppressed. The bridge structure 282 or 284 is also provided in the structure of FIG. 13, and the amount of magnetic flux existing between the magnetic pole piece 280 and the auxiliary magnetic pole 290 is limited by saturating the magnetic circuit including the bridge section. is doing. At the end of the auxiliary pole side magnet from the bridge portions 282 and 284, the iron core width between the magnet and the outer periphery of the rotor on the stator side is gradually increased. In the vicinity of both ends of the permanent magnets 254 and 256, the width of the iron core between the magnet and the outer periphery of the rotor on the stator side is gradually increased as the auxiliary magnetic pole 290 is approached. The change in the amount of magnetic flux in the circumferential direction in the air gap gradually changes from the portion where the magnets 254 and 256 are present to the auxiliary magnetic pole. The torque pulsation is reduced by the gentle change in the amount of magnetic flux. There is an effect that the cogging of the torque pulsation can be reduced.
Furthermore, as described above, the thickness of the permanent magnet in the radial direction is reduced between the bridge portions 282 and 284 and both end portions of the permanent magnet, so that the magnetomotive force of the magnet is gently reduced, and the stator 230 and the rotor The amount of magnetic flux between 250 and 250 decreases smoothly.
FIG. 14 shows the magnetic flux distribution in the circumferential direction of the gap 222 when no current flows through the stator winding. FIG. 14 (A) shows the structure of the stator and the rotor described in FIG. 13. The rotor 230 and the stator 250 have a circular shape centering on the rotation axis of the rotor, but are planar. This is shown in the figure. FIG. 14B shows the change in the circumferential direction of the magnetic flux amount of the gap 222, that is, the magnetic flux density. Between the auxiliary magnetic pole part 290 and the stator 230, the amount of magnetic flux by the permanent magnets 254 and 256 is substantially zero as shown by the area (d) in FIG. 14 (B). Between the left end portion of the permanent magnet 254/256 and the bridge portion 282, the magnet width in the radial direction is gradually increased, and the magnetic force is gradually increased. Along with this, as shown in region (a) of FIG. 14B, the amount of magnetic flux from the rotor 250 to the stator 230 gradually increases. Between the bridge part 282 and the bridge part 284, the thickness of the magnet in the diametrical direction of the rotor changes gently, and the magnet center part is thicker than the end part. The amount of magnetic flux from the rotor to the stator is the end of the magnet, as shown by the region (b) in FIG. 14 (B), where the amount of magnetic flux at the center of the magnetic pole is large corresponding to the radial thickness of the magnet. The magnetic flux amount changes more slowly than the region (a) or the region (c) in a state where the magnetic flux amount at the magnetic pole end is small. Between the bridge portion 282 and the right end portion of the permanent magnet 254/256, the magnet width in the radial direction of the rotor is gradually decreased, and the magnetic force is gradually decreased. Along with this, as shown in a region (c) of FIG. 14B, the amount of magnetic flux from the rotor 250 to the stator 230 is gradually reduced. The change in the amount of magnetic flux in the region (a) and the region (c) is based on the change in the radial thickness of the magnet, and this change is a little sharper than the region (b), but is a smooth change that is not angular. Yes, the pulsation of torque and generated voltage can be reduced.
In the region (d) of FIG. 14 (B), the magnetic flux by the permanent magnet is almost zero as described above. The further right side of the auxiliary magnetic pole portion 290 at the right end in FIG. 14 (A) is the adjacent magnetic pole, and the shape of the permanent magnet is the same, but the magnetization direction is reversed. That is, the stator side is the S pole and the center side of the rotor is the N pole. The relationship between the thickness of the magnet in the radial direction and the strength of the magnetic flux is as described above, but the magnetization direction is opposite, and the direction of the magnetic field lines is the direction from the stator to the rotor.
<Effects of Embodiments of FIGS. 13 and 14>
13 and 14, the permanent magnet 254/256 is bonded to a rare earth magnet material and a precursor having good wettability, preferably SiO. ₂ Is used, and the above-described magnet is used, so that at least one of the following effects is provided.
Since the magnet of the effect 1 and a curved shape is used, as shown in FIG. 14 (B), the amount of magnetic flux based on the permanent magnet can be changed smoothly. Torque pulsation can be reduced when this rotating electrical machine is used as a motor. When used as a generator, the pulsation of the generated voltage can be reduced, the pulsation change of the load acting as a load can be reduced, and the influence of the load pulsation on the system including the rotating electrical machine can be reduced.
Effect 2, harmonic flux acts on the stator side of the rotor along with the shape of the slot and the like during operation. By making the above-mentioned rotor into a laminated structure of laminated electromagnetic steel sheets, iron loss and heat generation due to harmonic magnetic flux are suppressed. Further, in order to prevent the harmonic magnetic flux from acting on the permanent magnets 254/256 to generate eddy currents in the magnets and increase eddy current loss and heat generation of the magnets, an insulating film is applied to the powder surface of the magnet material. After the formation, the magnetic material formed from the magnet powder is impregnated with a binder. Thereby, the electrical resistance inside the permanent magnet can be increased, the eddy current loss can be reduced, and the heat generation of the magnet can be reduced. In a rotating electrical machine for automobiles, in particular, a rotating electrical machine for hybrids, there is a possibility that the magnet is used under a high temperature condition in which the ambient temperature exceeds 100 degrees, and it is desirable to reduce internal heat generation of the magnet. Magnets using rare earth materials should be used at 180 degrees or less, preferably 140 degrees or less, and it is desirable to reduce internal heat generation.
<Embodiment of FIGS. 15 to 18>
FIG. 15 shows another embodiment of a three-phase motor rotating electrical machine. The basic structure and operation of the stator 230 and the rotor 250 of the rotating electrical machine are the same as those of the rotating electrical machine shown in FIG. The stator 230 is provided with a three-phase stator winding as in FIG. 4, but the illustration is omitted.
The stator core 232 and the rotor core 252 are formed by compressing iron powder that has been subjected to a process of attaching an electrical insulating film to the surface. The stator core 232 has a structure formed by compressing iron powder. By adopting such a structure, the stator winding is formed first, the stator winding is temporarily fixed, the iron winding is filled so as to incorporate the temporarily fixed stator winding, and then the iron powder is filled. By forming the entire stator by compression molding, the productivity is improved and the space factor of the stator winding is improved. Furthermore, eddy current can be reduced and the efficiency of the rotating electrical machine is improved.
The rotor core 252 can be reduced in eddy current of the rotor core 250 by compressing and molding the iron powder that has been subjected to the process of attaching an electrical insulating film to the surface. Further, the permanent magnets 254 and 256 described below have a structure for reducing eddy current, and the internal heat generation of the rotor 250 can be reduced comprehensively. Rare earth permanent magnets have the disadvantage that their magnetic properties deteriorate, that is, demagnetize when the temperature rises. In-vehicle rotating electrical machines are often used in situations where the ambient temperature is high, and reducing internal heat generation is very preferable for maintaining high reliability.
In FIG. 15, the rotor 250 is compression-molded with iron powder whose surface is electrically insulated, and a magnet insertion hole 258 is provided in the rotor 250 that has been compression-molded. A magnet assembly 270 is inserted into the magnet insertion hole. This structure is the same as the structure shown in FIG. 4 except that the magnet inserted into the magnet insertion hole 258 is a magnet assembly 270. In this embodiment, a rotor 250 is provided, and each magnet insertion hole 258 has a magnet assembly 270 disposed therein. However, the four magnet insertion holes 258 are an example, and may be eight, ten, or twelve. The magnet inserted into each magnet insertion hole 258 forms a pole of the rotor, but the magnet that forms the pole may be divided and inserted as shown in FIG. The magnet assembly 270 includes a permanent magnet 254/256 and an iron core obtained by compressing a powdery iron core described below, and acts as a main magnetic pole. In this embodiment, auxiliary magnetic poles 290 that generate reluctance torque exist between the main magnetic poles. The method for manufacturing the magnet assembly will be described below with reference to FIG. 16 or FIG.
In FIG. 16, steps 12 to 25 are the same as described in FIG. In step 12, an electrical insulating film is formed on the surface of the plate-like rare earth magnetic material, and in step 15, a press machine press-molds it into a predetermined shape to produce a magnetic body having a predetermined shape. In step 20, a precursor of a magnetic binder having a predetermined shape is impregnated, and in step 25, the binder is cured by being heated to several hundred degrees to produce a magnetic body. In step 25, since the temperature for curing the binder is low, the insulating film formed in step 12 is less damaged and can maintain high electrical resistance. Further, there is almost no change in the shape of the magnetic body in step 25. In the embodiment shown in FIGS. 4 and 13, the magnetic body made in step 25 is inserted into the magnet insertion hole. In the embodiment shown in FIG. 16, the magnetic body and powder made in step 25 are used. The magnet core is made by compression-molding the iron core material in a step 30 in step 30. In step 35, the magnet assembly is inserted into the magnet insertion hole 258 and magnetized. In step 30, the magnet assembly is compression-molded so that a powdery magnetic core exists on one side or both sides of the magnetic body. The powdered iron core material used in step 30 has an electrical insulating film formed on the surface thereof, and has a large electric resistance and very little eddy current loss.
In the above-described embodiment, a process for forming an electrical insulating film on the surface of the plate-like rare earth magnetic material is performed. However, when the binder precursor is impregnated in the step 20, the binder precursor enters between the rare earth magnetic materials that are layered, and an electrical insulating film is formed between the layered rare earth magnetic materials. Therefore, even if it does not perform the process which produces an electrical insulating film, it will have an electrical resistance 5 to 10 times or more compared with the conventional sintered rare earth magnet. Accordingly, the heat generation is reduced by 5 to 10 times or more. This also applies to the embodiment shown in FIG.
FIG. 17 shows another embodiment of FIG. The powdered rare earth magnetic material having an insulating film formed on the surface in step 12 is compression-molded into a predetermined shape in step 15. After step 15, in step 17, it is compression molded into a predetermined shape together with a powdered iron core material having an insulating film on the surface, and a porous magnet assembly is made. In step 22, the porous magnet assembly is impregnated with the binder precursor, and in step 27, the precursor of the binder is cured by heat treatment to produce a magnet assembly. In step 37, the magnet assembly is inserted into the rotor magnet insertion hole 258 and magnetized. Note that the binder precursor may be poured after the magnet assembly is inserted into the magnet insertion hole. In this case, the porous magnet assembly in the previous stage of the step 22 and the step 27 may be inserted into the magnet insertion hole 258 of the rotor, and then the steps 22 and 27 may be performed. And may be cured by heat treatment.
In FIG. 17, as in the description of FIG. 16, an insulating film is formed on the plate-like powder of rare earth magnetic material in step 12. By doing in this way, electrical resistance can be made very high and the eddy current in a magnet can be made very low. However, even if the insulating film is not formed on the powder surface of the rare earth magnetic material in step 12, a thin film of SiO-based amorphous state is formed on the powder surface of the rare earth magnetic material. It becomes high, eddy current can be reduced, and heat generation inside the magnet can be kept low.
The thin film of the SiO type amorphous state has an effect of increasing electric resistance as well as an effect of a binder. Moreover, since it is in the form of a thin film in an amorphous state, the ratio of the magnetic material per unit volume of the magnet can be increased, and the magnetic characteristics are also good.
FIG. 18 is a view showing a state in which the porous magnet assembly 270 in step 22 is impregnated with a binder precursor. SiO, which is a binder, in the container 360 ₂ The precursor magnetic solution 362 is contained, and the porous magnet assembly 270 is immersed in the solution. The magnet assembly 270 includes a magnet 254/256 which is a porous magnetic body and a dust core 312 or 314 provided on the outer periphery thereof. As described above, the dust cores 312 and 314 are iron cores obtained by compression-molding pure iron powder whose surface is treated with an insulating film. Since the iron powder is deformed in the powder iron core part, the solution is difficult to penetrate, but the porous magnetic material part is penetrated by the precursor with good wettability, and the porous solution fills the porous pores. It becomes. Thereafter, in the step 27, the precursor is cured by heat treatment and has a binding action.
In the description using FIGS. 15 to 18, the rotor 250 is compression-molded with iron powder whose surface is electrically insulated, and the magnet-insertion hole 258 is provided in the compression-molded rotor 250. Yes. However, as described above, a manufacturing method different from the manufacturing method in which the magnet insertion hole 258 is provided in the rotor 250 in advance and the magnet is inserted into the magnet insertion hole 258 may be used. In this case, the magnet assembly 270 is temporarily fixed, and the iron powder that has been electrically insulated so as to incorporate the temporarily fixed magnet assembly 270 is supplied, and the iron powder is incorporated in the state where the magnet assembly 270 is incorporated. And the rotor 250 is compression-molded. By manufacturing in this way, the magnet assembly 270 and the rotor core 252 can be integrally formed.
<Effects of Embodiment of FIGS. 15 to 18>
The embodiment described in FIGS. 15 to 18 has one, a plurality, or all of the following effects.
Effect 1 The shape of the magnet insertion hole 258 provided in the rotor 250 of FIG. 15 can be made simple. When the rotor iron core is made by cutting magnetic steel sheets and laminating the cut magnetic steel sheets, the workability is improved by making the magnet insertion hole a simple shape. Although it is possible to make the shape of the magnets 254/256 have a curved shape, it is easy to form a magnet insertion hole in an electromagnetic steel sheet by cutting such as punching in accordance with such a curve. There is no workability. Such a decrease in workability can be prevented.
When the rotor core 252 is manufactured by compression molding of iron powder instead of using the laminated electromagnetic steel sheet, the shape of the compressor to be manufactured can be made simple. This makes the compressor mold difficult to wear and reduces the possibility of breakage.
Effect 2, the compression-molded magnetic body may have a narrow end, a bend as a whole, or a shape that is vulnerable to mechanical shock. In the case of a shape that is vulnerable to such an impact, there is a risk that the magnetic body molded into the magnet insertion hole of the rotor may be damaged when inserted. In the present embodiment, the powder iron core is reinforced from a shape that is vulnerable to impact to a shape that is resistant to impact, and thus is less likely to break. Moreover, it is possible to make it easy to insert into the magnet insertion hole.
The internal heat generation of the rotor can be reduced. That is, the heat generation inside the magnet can be reduced, and the rotor core 252 of the rotor 250 is made by compression molding powdered iron powder having an electric insulating film on the surface, thereby reducing the heat generation inside the rotor core 252. it can. Rare earth permanent magnets have the disadvantage of demagnetizing when the temperature rises above a predetermined temperature, but it is possible to suppress the temperature rise of the permanent magnets by suppressing heat generation. This makes it easy to maintain high reliability of the rotating electrical machine.
<Other embodiments>
FIG. 19 shows another embodiment of the magnet assembly 270 of FIG. The rotor 250 to which the magnet assembly 270 shown in FIG. 19 is fixed is the same as described above. That is, the eddy current of the rotor core 250 can be reduced by compressing and molding the rotor core 252 with iron powder that has been subjected to a process of attaching an electrical insulating film to the surface. The magnet assembly 270 described below has a structure that reduces eddy currents, and the internal heat generation of the rotor 250 can be reduced comprehensively. Rare earth permanent magnets have the disadvantage that their magnetic properties deteriorate, that is, demagnetize when the temperature rises. In-vehicle rotating electrical machines are often used in situations where the ambient temperature is high, and reducing internal heat generation is very preferable for maintaining high reliability.
A magnet assembly 270 shown in FIG. 19A has the same structure as the magnet assembly shown in FIG. FIG. 19B shows a structure in which two magnetic bodies are inserted into the magnet insertion hole 258. Forming a complex-shaped magnetic flux insertion hole in the rotor core 252 reduces productivity. Further, the magnets 272 and 274 themselves are thin and are vulnerable to mechanical shock. Therefore, a plurality of magnetic bodies 272 and 274 are integrally compression-molded with a powdered iron core material further coated with an electrical insulating film, and handled as a shape resistant to impact. A plurality of magnetic bodies 272 and 274 are integrated with the dust cores 314 and 312, and this is easier to form integrally with the rotor core 252, and the workability of manufacturing the rotor is improved.
FIG. 19 (C) shows a structure in which the magnetomotive force of the magnet assembly is changed. The powder iron core and the magnetic body are compression-molded. The compression-molded magnet 254/256 and the dust core are compressed together. Molded. Workability is improved as described above. Further, the amount of magnetic flux in the circumferential direction of each main magnetic pole can be changed with high accuracy along the axial direction of the rotating electrical machine, and torque pulsation and induced voltage pulsation can be reduced.
FIG. 19 (D) shows a magnet assembly composed of a compacted iron core 314 formed by compression molding of a powdery iron core and a magnet 254/256 formed by compression molding, and the magnet insertion hole of the rotor core is largely formed. The magnet assembly 270 can be inserted into the magnet insertion hole formed in the above-described size with the magnet 254/256 having an optimum shape with high accuracy. Thereby, improvement of workability | operativity and ensuring of the favorable characteristic by precision improvement can be made compatible.
19 (A) to 19 (D), as described above, by using iron powder whose surface is treated with an insulating film, eddy currents in the dust cores 314 and 312 can be reduced, and iron loss can be reduced. Can be reduced. Further, since the magnets 254/256, 272, and 274, which are magnetic materials, use a magnetic powder material whose surface is treated with an insulating film, the amount of eddy current inside the magnet can be reduced.
The magnet assembly 270 in FIGS. 19C and 19D has magnets arranged asymmetrically in the circumferential direction, and is suitable for use as a magnetic pole of a rotating electrical machine whose rotational direction is one direction.
FIG. 20 shows still another embodiment of the magnet assembly 270. The magnet assembly 270 inserted into the magnet insertion hole 258 is composed of a magnet 272, a magnet 270, and a dust core 312. The magnet 272 and the magnet 270 are skewed with respect to the rotation axis. Thereby, the torque pulsation of a rotary electric machine and the torque pulsation of an induced voltage can be reduced. The structure of the magnet assembly has a skew effect, the manufacture of the rotor core is easy, and the productivity is improved as a whole. Further, the manufacturing accuracy is improved and the characteristics are improved.
The magnet assembly disclosed in FIG. 21 has a structure in which a magnetic assembly is formed by combining a magnetic body 254/256 and a nonmagnetic material such as aluminum. FIG. 21 (A) shows a nonmagnetic material 266 provided on both sides in the circumferential direction of the magnetic material 254/256. In the manufacturing method of FIG. 16 or FIG. The magnet assembly is compression molded by adding the non-magnetic material powder. The non-magnetic material 266 functions in the same manner as the air gaps 262 and 264 in FIG. By press-molding the shape of the non-magnetic material 266, it can be molded with high accuracy and the characteristics of the rotating electrical machine are improved. FIG. 21 (B) shows a structure in which a dust core is added to one side to form a magnet assembly. This is suitable for rotating electric machines in one direction.
In FIGS. 21A and 21B, the voids of the rotor core are compression-molded with a non-magnetic material, and good characteristics can be obtained by maintaining high molding accuracy. Further, since the voids in the iron core are not required, the mechanical strength is increased. In addition, workability is improved.
FIG. 22 shows cross sections of the stator 230 and the rotor 250 in the same manner as the cross section shown in FIG. The structure and operating principle are also almost the same. As in FIG. 4, the stator core 232 of the stator 230 and the rotor core 252 of the rotor 250 are formed by compressing iron powder having an electric insulating film on the surface. As in FIG. 4, the eddy current in the stator core 232 can be reduced, the efficiency of the rotating electrical machine can be improved, and the heat generation in the stator core 232 can be reduced. Similarly, the rotor core 252 can reduce internal heat generation and eddy current loss, thereby improving the efficiency of the rotating electrical machine.
The difference between the embodiment shown in FIG. 22 and the embodiment shown in FIG. 4 is that the shape of the permanent magnet 276 shown in FIG. 22 is a block shape. The manufacturing method is as described with reference to FIGS. 8 to 12 or with reference to FIGS. The operation of the permanent magnet 276 and the operation of the stator 230 and the rotor 250 are substantially the same as those described in FIG. 4. The permanent magnet 276 corresponds to the permanent magnets 254 and 256 in FIG. The block-type magnet has a rectangular cross section in a plane perpendicular to the rotation axis of the rotor, and extends along the rotation axis. Each permanent magnet 276 acts as a magnetic pole, and an auxiliary magnetic pole 290 that passes a q-axis magnetic flux exists between the magnetic poles. The rotor core 252 on the stator side of each permanent magnet 276 acts as a pole piece 280 as in FIG. As described above, a bridge portion exists between the magnetic pole piece 280 and the auxiliary magnetic pole 290, and the amount of magnetic flux passing through the bridge portion is limited to be very small due to a saturation phenomenon. The permanent magnets 276 constituting the magnetic poles have different magnetization directions on both sides of the magnetic pole piece 280. For example, if one permanent magnet 276 is magnetized so that the stator side has an N pole, the other permanent magnet 276 is provided. Is magnetized so that the stator side is the south pole.
The permanent magnet 276 of FIG. 22 may be skewed as shown in FIG. 20, in which case torque pulsation is reduced. Further, the permanent magnet 276 of FIG. 22 may have a non-magnetic material such as aluminum or stainless steel as shown in FIG. In this case, the magnetic air gap is made of the aluminum material or the stainless steel material, and has the same action as the magnetic air gaps 262 and 264 described with reference to FIG. Further, when the nonmagnetic material shown in FIG. 21 is used for the magnetic air gaps 262 and 264 in comparison with the physical air gap, there is an advantage that the mechanical strength is increased, and the bridge portions 282 and 284 described in FIG. It can be set as the shape with the favorable characteristic of a rotary electric machine. For example, even if it cannot be thinned in the radial direction due to mechanical strength, the mechanical strength can be increased as described above. Therefore, when the nonmagnetic material shown in FIG. It becomes possible.
FIG. 23 shows a structure in which the shape of the permanent magnet 276 in FIG. 22 is changed, and a permanent magnet is provided on a rotor core 252 formed by compressing iron powder having an electric insulating film on the surface. is there. In particular, FIG. 23 shows a structure in which a permanent magnet is embedded in the rotor core 252. The basic operation of the rotating electrical machine disclosed in FIG. 23 is substantially the same as FIG. 4 and FIG. FIG. 23A shows an example in which the shape of the permanent magnet 276 is an arc type. FIG. 23B is an example in which the shape of the permanent magnet 276 is U-shaped. FIG. 23C shows an example in which the shape of the permanent magnet 276 is V-shaped. Similarly to the rotating electrical machine with the built-in block magnet shown in FIG. 22, the rotating electrical machine shown in FIG. 23 (A), FIG. 23 (B), and FIG. Exists and the principle of torque generation is substantially the same. As described with reference to FIG. 15, a rotor core 252 provided with a magnet insertion hole in advance is formed, and the magnet body described with reference to FIGS. 8 to 11 or the magnet assembly described with reference to FIGS. Can be inserted to produce a rotor. Further, the magnet body described in FIGS. 8 to 11 or the magnet assembly described in FIGS. 16 to 21 is manufactured in advance, and the magnet body, the magnet assembly and iron powder are compression molded. A rotor may be manufactured.
FIG. 24 is a partially enlarged view of a rotor showing still another embodiment of the rotor 250 shown in FIG. 22 and FIG. The rotor 250 shown in FIG. 24 is different from the shape of the permanent magnet 276 shown in FIG. 22 and FIG. When a complex-shaped permanent magnet is used, such as the so-called crescent-shaped permanent magnet 276 shown in FIG. 24, it is difficult to provide a complex-shaped magnet insertion hole in the laminated steel sheet. Productivity can be improved by using a powdery iron core having an electrical insulating film on the surface as described above instead of the laminated steel sheet. That is, by compressing and molding the powdery iron core and the complex-shaped permanent magnet integrally, a rotor 250 incorporating the complex-shaped permanent magnet can be manufactured, for example, as shown in FIG.
FIG. 25 is a partially enlarged view of a rotor showing still another embodiment of the rotor 250 shown in FIGS. The rotor 250 shown in FIG. 25 is different from the shape of the permanent magnet 276 shown in FIGS. 22 to 24. The permanent magnet 276 shown in FIG. 25 has an asymmetrical magnet thickness in the rotational direction of the rotor. A rotating electrical machine may require similar characteristics in both directions of rotation, or may require different characteristics depending on the direction of rotation. In this case, it is desirable to match the magnet shape of the permanent magnet 276 according to the characteristics to the required characteristics. By matching these characteristics, the permanent magnet 276 can be made asymmetric.
A rotating electrical machine may be used in both motor and generator operating modes. Even when the direction of the rotor of the rotating electrical machine is the same, it may be desirable to make the permanent magnet 276 asymmetric when used in both motor and generator operating modes. In this case, for example, as shown in FIG. 25, the radial thickness of the permanent magnet 276 is asymmetric in the circumferential direction, and the generated magnetic flux density is asymmetric in the circumferential direction.
A rotor having an asymmetric shape in the circumferential direction shown in FIG. 25 is prepared by preliminarily creating a magnet body or magnet assembly as an asymmetric shape, and compressing and molding the powdered iron core and the above-described complex shape permanent magnet as one body. Easy to manufacture.
FIG. 26 and FIG. 27 show still another embodiment. In FIG. 27, the stator is the same as FIG. The stator 230 has a stator core 232 having a slot 234, and the stator 230 and the stator core 232 have the same structure as described in FIG.
The basic structure and operation are the same as those described in FIGS. 4 and 15 except that the arrangement of the permanent magnets of the rotor 250 is different. Each pole of the rotor 250 has a plurality of permanent magnets, for example, two permanent magnets arranged in the radial direction of the rotor. 26 and 27, a permanent magnet 277 and a permanent magnet 278 are arranged so as to overlap each other in the radial direction of the rotor, and these permanent magnets 277 and 278 constitute each magnetic pole of the rotor 250. The permanent magnets 277 and 278 use the magnets described with reference to FIGS. These permanent magnets 277 and 278 are manufactured in advance, and then the permanent magnets 277 and 278 are temporarily fixed inside the compressor, and then the interior of the compressor is filled with iron powder having an electrically insulating film on the surface. The rotor is formed by compression molding the permanent magnet and filled iron powder with the compressor. By doing so, the rotor can be easily manufactured.
FIG. 27 shows a rotor 250 in which nonmagnetic powder 279 is mixed in a place where a magnetic space is to be specially provided and compression-molded by the compressor. Conventionally, it was created by forming a physical gap filled with air in a magnetic space. In this embodiment, the nonmagnetic powder 279 is mixed to form a magnetic space, so that the mechanical strength is stronger than that of the conventional structure. As shown in FIGS. 26 and 27, the rotor 250 can be easily manufactured by compressing the iron powder together with the magnet body and the magnet assembly with a compressor, and a portion requiring a magnetic space is required. A non-magnetic powder 279 is mixed into the rotary electric machine, so that a rotary electric machine suitable for the characteristics required for the rotary electric machine can be easily manufactured.
26 and 27, the permanent magnets 277 and 278 are manufactured and used in advance by the manufacturing method described with reference to FIGS. 8 to 12, but steps 10 to 15 in FIGS. 8 to 9 are performed. In this state, the stator is temporarily fixed inside the compressor, and then the iron powder whose surface is provided with an electric insulating film is filled in the compressor, and the magnet manufactured in the above steps 10 to 15 and the iron powder filled. The rotor may be formed by compression molding with the above compressor. In this case, since the magnet is not impregnated with the binder precursor, the binder SiO as shown in FIG. ₂ A rotor formed by compression molding is immersed in the precursor of the binder SiO. ₂ The precursor may be impregnated. Binder SiO ₂ In addition to impregnating the magnet portion, the precursor of the surface of the rotor 250 compression-molded with iron powder and the vicinity of the surface are bound to the binder SiO. ₂ It is possible to fix with, and has the effect of increasing the mechanical strength. The rotor 250 formed by compression-molding iron powder has a drawback that the mechanical strength against centrifugal force or the like tends to be lower than that of the laminated iron core, and it is a very desirable effect that the mechanical strength is increased.

Claims (42)

A stator having a stator core and a three-phase stator winding;
Having a gap between the stator and a rotor disposed rotatably,
The rotor includes a rotor core and a plurality of permanent magnets, and the permanent magnets constitute field poles,
The rotor core is formed by compressing iron powder,
The permanent magnet contains an alkoxy group and is formed by binding rare earth magnetic powder with an amorphous and continuous film-shaped binder containing SiO ₂ as a main component,
The rotor is formed with an even number of field poles composed of the permanent magnets in the circumferential direction of the rotating shaft,
When a three-phase alternating current is supplied to the stator winding , rotational torque is generated in the rotor having the permanent magnet formed by binding rare earth magnetic powder with a SiO-based material . Permanent magnet rotating electric machine. A stator having a stator core and a three-phase stator winding;
Having a gap between the stator and a rotor disposed rotatably,
The stator core is formed by compressing iron powder,
The rotor includes a rotor core and a plurality of permanent magnets, and the permanent magnets constitute field poles,
The permanent magnet contains an alkoxy group and is formed by binding rare earth magnetic powder with an amorphous and continuous film-shaped binder containing SiO ₂ as a main component,
The rotor is formed with an even number of field poles composed of the permanent magnets in the circumferential direction of the rotating shaft,
When a three-phase alternating current is supplied to the stator winding , rotational torque is generated in the rotor having the permanent magnet formed by binding rare earth magnetic powder with a SiO-based material . Permanent magnet rotating electric machine. In the permanent magnet rotating electric machine according to claim 1 or 2 ,
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 to form the permanent magnet. Rotating electric machine. In the permanent magnet rotating electric machine according to any one of claims 1 to 3 ,
The SiO-based material or the binder mainly composed of SiO ₂ for forming the permanent magnet is a precursor of SiO ₂ , alkoxysiloxane, alkoxysilane, a product obtained by hydrolysis thereof, and dehydration condensation thereof. An in-vehicle permanent magnet rotating electrical machine including at least one kind of object and water. A stator having a stator core and a stator winding;
Having a gap between the stator and a rotor disposed rotatably,
The rotor includes a rotor core and a plurality of permanent magnets,
The permanent magnet is formed by binding magnetic powder with a SiO-based material,
The rotor core is formed by compressing iron powder,
A rotor having a permanent magnet formed by binding magnetic powder with a SiO-based material and provided on a rotor core made by compression molding iron powder, and a stator winding. When alternating current is supplied, rotational torque is generated,
SiO-based material for forming the permanent magnet or SiO ₂ The binder mainly composed of SiO is SiO. ₂ A permanent magnet rotating electrical machine for vehicle use containing at least one of alkoxysiloxane, alkoxysilane, a product of hydrolysis thereof, and a dehydration condensate thereof, and water. A stator having a stator core and a stator winding;
Having a gap between the stator and a rotor disposed rotatably,
The rotor includes a rotor core and a plurality of permanent magnets,
The rotor is formed with an even number of field poles composed of the permanent magnets in the circumferential direction of the rotating shaft,
The permanent magnet is magnetized so that the magnetic flux generated by the permanent magnet passes through the stator core, and the permanent magnet is magnetized so that the magnetization direction is reversed for each field pole,
The rotor core is formed by compressing iron powder,
The permanent magnet is formed by binding magnetic powder with a SiO-based material,
A rotor having a permanent magnet formed by binding magnetic powder with a SiO-based material and provided on a rotor core made by compression molding iron powder, and a stator winding. When alternating current is supplied, rotational torque is generated,
SiO-based material for forming the permanent magnet or SiO ₂ The binder mainly composed of SiO is SiO. ₂ A permanent magnet rotating electrical machine for vehicle use containing at least one of alkoxysiloxane, alkoxysilane, a product of hydrolysis thereof, and a dehydration condensate thereof, and water. A stator having a stator core and a three-phase stator winding;
Having a gap between the stator and a rotor disposed rotatably,
The rotor includes a rotor core and a plurality of permanent magnets,
The rotor is formed with an even number of field poles composed of the permanent magnets in the circumferential direction of the rotating shaft,
Auxiliary magnetic poles are formed between the field magnetic poles, and permanent magnets constituting the field magnetic poles on both sides of the auxiliary magnetic poles are magnetized with different polarities,
The rotor core is formed by compressing iron powder,
The permanent magnet has a rare earth magnetic powder bound with a SiO-based material in an amorphous state,
When a three-phase alternating current is supplied to the stator winding, a rotational torque is generated in the rotor having the permanent magnet formed by binding rare earth magnetic powder with a SiO-based material,
SiO-based material for forming the permanent magnet or SiO ₂ The binder mainly composed of SiO is SiO. ₂ A permanent magnet rotating electrical machine for vehicle use containing at least one of alkoxysiloxane, alkoxysilane, a product of hydrolysis thereof, and a dehydration condensate thereof, and water. A stator having a stator core and a stator winding;
Having a gap between the stator and a rotor disposed rotatably,
The stator core is formed by compressing iron powder,
The rotor includes a rotor core and a plurality of permanent magnets,
The permanent magnet is formed by binding magnetic powder with a SiO-based material,
A rotor having a permanent magnet formed by binding magnetic powder with a SiO-based material and provided on a rotor core made by compression molding iron powder, and a stator winding. When alternating current is supplied, rotational torque is generated,
SiO-based material for forming the permanent magnet or SiO ₂ The binder mainly composed of SiO is SiO. ₂ A permanent magnet rotating electrical machine for vehicle use containing at least one of alkoxysiloxane, alkoxysilane, a product of hydrolysis thereof, and a dehydration condensate thereof, and water. A stator having a stator core and a stator winding;
Having a gap between the stator and a rotor disposed rotatably,
The stator core is formed by compressing iron powder,
The rotor includes a rotor core and a plurality of permanent magnets,
The rotor is formed with an even number of field poles composed of the permanent magnets in the circumferential direction of the rotating shaft,
The permanent magnet is magnetized so that the magnetic flux generated by the permanent magnet passes through the stator core, and the permanent magnet is magnetized so that the magnetization direction is reversed for each field pole,
The permanent magnet is formed by binding magnetic powder with a SiO-based material,
A rotor having a permanent magnet formed by binding magnetic powder with a SiO-based material and provided on a rotor core made by compression molding iron powder, and a stator winding. When alternating current is supplied, rotational torque is generated,
SiO-based material for forming the permanent magnet or SiO ₂ The binder mainly composed of SiO is SiO. ₂ A permanent magnet rotating electrical machine for vehicle use containing at least one of alkoxysiloxane, alkoxysilane, a product of hydrolysis thereof, and a dehydration condensate thereof, and water. A stator having a stator core and a three-phase stator winding;
Having a gap between the stator and a rotor disposed rotatably,
The stator core is formed by compressing iron powder,
The rotor includes a rotor core and a plurality of permanent magnets,
The rotor is formed with an even number of field poles composed of the permanent magnets in the circumferential direction of the rotating shaft,
Auxiliary magnetic poles are formed between the field magnetic poles, and permanent magnets constituting the field magnetic poles on both sides of the auxiliary magnetic poles are magnetized with different polarities,
The permanent magnet has a rare earth magnetic powder bound with a SiO-based material in an amorphous state,
When a three-phase alternating current is supplied to the stator winding, a rotational torque is generated in the rotor having the permanent magnet formed by binding rare earth magnetic powder with a SiO-based material,
SiO-based material for forming the permanent magnet or SiO ₂ The binder mainly composed of SiO is SiO. ₂ A permanent magnet rotating electrical machine for vehicle use containing at least one of alkoxysiloxane, alkoxysilane, a product of hydrolysis thereof, and a dehydration condensate thereof, and water. In the permanent magnet rotating electric machine according to any one of claims 1 to 10 ,
The SiO-based material for forming the permanent magnet or the binder mainly composed of SiO ₂ is composed of an alkoxysiloxane, an alkoxysilane, a hydrolysis product thereof, and a dehydration condensate thereof, which are precursors of SiO ₂ . An in-vehicle permanent magnet rotating electrical machine comprising at least one kind and water, and further containing an alcohol and a catalyst for hydrolysis. A stator having a stator core and a stator winding;
Having a gap between the stator and a rotor disposed rotatably,
The rotor includes a rotor core and a plurality of permanent magnets,
The permanent magnet is formed by binding magnetic powder with a SiO-based material,
The rotor core is formed by compressing iron powder,
A rotor having a permanent magnet formed by binding magnetic powder with a SiO-based material and provided on a rotor core made by compression molding iron powder, and a stator winding. When alternating current is supplied, rotational torque is generated,
SiO-based material for forming the permanent magnet or SiO ₂ The binder mainly composed of SiO is SiO. ₂ A permanent component for automobile use, which contains at least one of alkoxysiloxane, alkoxysilane, hydrolysis product thereof, and dehydration condensate thereof, water, and an alcohol and a catalyst for hydrolysis. Magnet rotating electric machine. A stator having a stator core and a stator winding;
Having a gap between the stator and a rotor disposed rotatably,
The rotor includes a rotor core and a plurality of permanent magnets,
The rotor is formed with an even number of field poles composed of the permanent magnets in the circumferential direction of the rotating shaft,
The permanent magnet is magnetized so that the magnetic flux generated by the permanent magnet passes through the stator core, and the permanent magnet is magnetized so that the magnetization direction is reversed for each field pole,
The rotor core is formed by compressing iron powder,
The permanent magnet is formed by binding magnetic powder with a SiO-based material,
A rotor having a permanent magnet formed by binding magnetic powder with a SiO-based material and provided on a rotor core made by compression molding iron powder, and a stator winding. When alternating current is supplied, rotational torque is generated,
SiO-based material for forming the permanent magnet or SiO ₂ The binder mainly composed of SiO is SiO. ₂ A permanent component for automobile use, which contains at least one of alkoxysiloxane, alkoxysilane, hydrolysis product thereof, and dehydration condensate thereof, water, and an alcohol and a catalyst for hydrolysis. Magnet rotating electric machine. A stator having a stator core and a three-phase stator winding;
Having a gap between the stator and a rotor disposed rotatably,
The rotor includes a rotor core and a plurality of permanent magnets,
The rotor is formed with an even number of field poles composed of the permanent magnets in the circumferential direction of the rotating shaft,
Auxiliary magnetic poles are formed between the field magnetic poles, and permanent magnets constituting the field magnetic poles on both sides of the auxiliary magnetic poles are magnetized with different polarities,
The rotor core is formed by compressing iron powder,
The permanent magnet has a rare earth magnetic powder bound with a SiO-based material in an amorphous state,
When a three-phase alternating current is supplied to the stator winding, a rotational torque is generated in the rotor having the permanent magnet formed by binding rare earth magnetic powder with a SiO-based material,
SiO-based material for forming the permanent magnet or SiO ₂ The binder mainly composed of SiO is SiO. ₂ A permanent component for automobile use, which contains at least one of alkoxysiloxane, alkoxysilane, hydrolysis product thereof, and dehydration condensate thereof, water, and an alcohol and a catalyst for hydrolysis. Magnet rotating electric machine. A stator having a stator core and a stator winding;
Having a gap between the stator and a rotor disposed rotatably,
The stator core is formed by compressing iron powder,
The rotor includes a rotor core and a plurality of permanent magnets,
The permanent magnet is formed by binding magnetic powder with a SiO-based material,
A rotor having a permanent magnet formed by binding magnetic powder with a SiO-based material and provided on a rotor core made by compression molding iron powder, and a stator winding. When alternating current is supplied, rotational torque is generated,
SiO-based material for forming the permanent magnet or SiO ₂ The binder mainly composed of SiO is SiO. ₂ A permanent component for automobile use, which contains at least one of alkoxysiloxane, alkoxysilane, hydrolysis product thereof, and dehydration condensate thereof, water, and an alcohol and a catalyst for hydrolysis. Magnet rotating electric machine. A stator having a stator core and a stator winding;
Having a gap between the stator and a rotor disposed rotatably,
The stator core is formed by compressing iron powder,
The rotor includes a rotor core and a plurality of permanent magnets,
The rotor is formed with an even number of field poles composed of the permanent magnets in the circumferential direction of the rotating shaft,
The permanent magnet is magnetized so that the magnetic flux generated by the permanent magnet passes through the stator core, and the permanent magnet is magnetized so that the magnetization direction is reversed for each field pole,
The permanent magnet is formed by binding magnetic powder with a SiO-based material,
A rotor having a permanent magnet formed by binding magnetic powder with a SiO-based material and provided on a rotor core made by compression molding iron powder, and a stator winding. When alternating current is supplied, rotational torque is generated,
SiO-based material for forming the permanent magnet or SiO ₂ The binder mainly composed of SiO is SiO. ₂ A permanent component for automobile use, which contains at least one of alkoxysiloxane, alkoxysilane, hydrolysis product thereof, and dehydration condensate thereof, water, and an alcohol and a catalyst for hydrolysis. Magnet rotating electric machine. A stator having a stator core and a three-phase stator winding;
Having a gap between the stator and a rotor disposed rotatably,
The stator core is formed by compressing iron powder,
The rotor includes a rotor core and a plurality of permanent magnets,
The rotor is formed with an even number of field poles composed of the permanent magnets in the circumferential direction of the rotating shaft,
Auxiliary magnetic poles are formed between the field magnetic poles, and permanent magnets constituting the field magnetic poles on both sides of the auxiliary magnetic poles are magnetized with different polarities,
The permanent magnet has a rare earth magnetic powder bound with a SiO-based material in an amorphous state,
When a three-phase alternating current is supplied to the stator winding, a rotational torque is generated in the rotor having the permanent magnet formed by binding rare earth magnetic powder with a SiO-based material,
The SiO-based material for forming the permanent magnet or the binder mainly composed of SiO ₂ is composed of an alkoxysiloxane, an alkoxysilane, a hydrolysis product thereof, and a dehydration condensate thereof, which are precursors of SiO ₂ . An in-vehicle permanent magnet rotating electrical machine comprising at least one kind and water, and further containing an alcohol and a catalyst for hydrolysis. The permanent magnet rotating electrical machine according to any one of claims 1 to 17 ,
The permanent magnet, compression molding the rare earth magnetic powder, the rare earth magnetic powder formed by compression molding is impregnated with a SiO ₂ precursor was molded by binding a rare earth magnetic powder with SiO ₂ , Permanent magnet rotating electric machine for in-vehicle use. A stator having a stator core and a stator winding;
Having a gap between the stator and a rotor disposed rotatably,
The rotor includes a rotor core and a plurality of permanent magnets arranged inside the rotor core;
The rotor core is formed by compressing iron powder,
In the rotor core, a plurality of auxiliary magnetic pole portions formed at equal intervals in the circumferential direction of the rotation shaft,
A permanent magnet insertion hole provided between the auxiliary magnetic pole portions;
Magnetic pole piece formed on the rotor core on the stator side of the permanent magnet insertion hole;
A magnetic gap formed between the permanent magnet and the auxiliary magnetic pole part, and a bridge part formed on a rotor core on the outer peripheral side of the magnetic gap,
The permanent magnet is disposed inside the permanent magnet insertion hole, and the permanent magnet is magnetized so that polarities of the permanent magnets disposed on both sides in the circumferential direction with the auxiliary magnetic pole interposed therebetween are opposite to each other. ,
The permanent magnet rotating electric machine for vehicle use, wherein the permanent magnet is formed by binding rare earth magnetic powder with amorphous and continuous film-shaped SiO ₂ . A stator having a stator core and a three-phase stator winding;
Having a gap between the stator and a rotor disposed rotatably,
The rotor includes a rotor core and a plurality of permanent magnets embedded in the rotor core and constituting a field pole,
The rotor core is formed by compressing iron powder,
The rotor core is formed with a plurality of permanent magnet insertion holes, a magnetic pole piece formed on a rotor core on the stator side of the permanent magnet insertion hole, and a circumferential direction of the rotation axis of the rotor core. A plurality of auxiliary magnetic pole portions and a bridge portion connecting the magnetic pole piece portion and the auxiliary magnetic pole are formed,
The permanent magnet is magnetized so that polarities of the permanent magnets arranged on both sides in the circumferential direction with the auxiliary magnetic pole in between are opposite to each other,
The permanent magnet has a rare earth magnetic powder arranged in a substantially layered manner and an amorphous, film-shaped SiO-based material that is present between the layers and binds the rare earth magnetic powder. Permanent magnet rotating electric machine. In the permanent magnet rotating electric machine according to any one of claims 19 and 20 ,
The permanent magnet constitutes a field pole,
The on-vehicle permanent magnet rotating electrical machine, wherein the permanent magnet has a curved shape so as to approach the outer peripheral side of the rotor as it approaches the auxiliary magnetic pole from the center of the field magnetic pole. In the permanent magnet rotating electric machine according to any one of claims 19 and 20 ,
The permanent magnets are arranged in a plurality of rows in the radial direction,
The on-vehicle permanent magnet rotating electrical machine has a curved shape so that the permanent magnet approaches the rotor outer peripheral side as it approaches the auxiliary magnetic pole side. In the permanent magnet rotating electric machine according to any one of claims 19 and 20 ,
The SiO-based material for binding the rare-earth magnetic powder of the permanent magnet includes at least one of an alkoxysiloxane, an alkoxysilane, a hydrolysis product thereof, and a dehydration condensate thereof, which are SiO ₂ precursors, and water. In-vehicle permanent magnet rotating electric machine. A stator having a stator core and a three-phase stator winding;
Having a gap between the stator and a rotor disposed rotatably,
The rotor includes a rotor core and a plurality of permanent magnets embedded in the rotor core and constituting a field pole,
The rotor core is formed by compressing iron powder,
The rotor core is formed with a plurality of permanent magnet insertion holes, a magnetic pole piece formed on a rotor core on the stator side of the permanent magnet insertion hole, and a circumferential direction of the rotation axis of the rotor core. A plurality of auxiliary magnetic pole portions and a bridge portion connecting the magnetic pole piece portion and the auxiliary magnetic pole are formed,
The permanent magnet is magnetized so that polarities of the permanent magnets arranged on both sides in the circumferential direction with the auxiliary magnetic pole in between are opposite to each other,
The permanent magnet is formed by binding rare earth magnetic powder with a SiO-based material containing an alkoxy group,
The SiO-based material for binding the rare earth magnetic powder of the permanent magnet is SiO ₂ An in-vehicle permanent magnet rotating electrical machine comprising at least one of alkoxysiloxane, alkoxysilane, a product of hydrolysis thereof, and a dehydration condensate thereof, and water. In the permanent magnet rotating electric machine according to any one of claims 19 and 20 ,
The material of SiO system for binding a rare earth magnetic powder of the permanent magnet, alkoxysiloxane that is a precursor of SiO _2, an alkoxysilane, hydrolysis product thereof, and at least one of the dewatering condensate, and water An in-vehicle permanent magnet rotating electric machine that further includes alcohol and a catalyst for hydrolysis. A stator having a stator core and a three-phase stator winding;
Having a gap between the stator and a rotor disposed rotatably,
The rotor includes a rotor core and a plurality of permanent magnets embedded in the rotor core and constituting a field pole,
The rotor core is formed by compressing iron powder,
The rotor core is formed with a plurality of permanent magnet insertion holes, a magnetic pole piece formed on a rotor core on the stator side of the permanent magnet insertion hole, and a circumferential direction of the rotation axis of the rotor core. A plurality of auxiliary magnetic pole portions and a bridge portion connecting the magnetic pole piece portion and the auxiliary magnetic pole are formed,
The permanent magnet is magnetized so that polarities of the permanent magnets arranged on both sides in the circumferential direction with the auxiliary magnetic pole in between are opposite to each other,
The permanent magnet is formed by binding rare earth magnetic powder with a SiO-based material containing an alkoxy group,
The SiO-based material for binding the rare earth magnetic powder of the permanent magnet is SiO ₂ Permanent magnet for vehicle use, comprising at least one of alkoxysiloxane, alkoxysilane, hydrolysis product thereof, and dehydration condensate thereof, and water, and further containing alcohol and a catalyst for hydrolysis. Rotating electric machine. In the permanent magnet rotating electric machine according to any one of claims 23 and 24 ,
The SiO-based material of the permanent magnet is an in-vehicle permanent magnet rotating electrical machine that contains a neutral catalyst as a catalyst for hydrolysis. The permanent magnet rotating electric machine according to claim 27 ,
An in-vehicle permanent magnet rotating electrical machine, wherein the neutral catalyst is a tin catalyst. In the permanent magnet rotating electric machine according to any one of claims 25 and 26 ,
An in-vehicle permanent magnet rotating electrical machine in which the total volume fraction of an alkoxysiloxane, an alkoxysilane, a hydrolysis product thereof, and a dehydration condensate thereof in a SiO-based material is 5 vol% or more and 96 vol% or less. The permanent magnet rotating electric machine according to claim 29 ,
The water content in the SiO-based material is equivalent to the hydrolysis reaction equivalent to the total amount of alkoxysiloxane, alkoxysilane, the product of hydrolysis thereof, and the alkoxysiloxane and alkoxysilane that are precursors of the dehydration condensate thereof. 1/10 to 1 of the in-vehicle permanent magnet rotating electric machine. The permanent magnet rotating electric machine according to any one of claims 19 to 29 ,
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 a binder mainly composed of SiO _2. An in-vehicle permanent magnet rotating electrical machine in which is formed. The permanent magnet rotating electric machine according to claim 31 ,
The said inorganic insulating film is a permanent magnet rotary electric machine for vehicles which consists of a coating film of a rare earth fluoride or an alkaline earth metal fluoride, or a phosphate chemical conversion treatment film. The permanent magnet rotating electric machine according to claim 32 ,
The coating film of rare earth fluoride or alkaline earth metal fluoride is Mg, Ca, Sr, Ba, La, Ce, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu fluoride. An in-vehicle permanent magnet rotating electrical machine containing at least one of them. The permanent magnet rotating electric machine according to claim 33 ,
The coating film of rare earth fluoride or alkaline earth metal fluoride has the rare earth fluoride or alkaline earth metal fluoride swelled in a solvent containing alcohol as a main component, and the rare earth fluoride or alkaline earth fluoride in a sol state. An in-vehicle permanent magnet rotating electric machine formed by using a treatment liquid in which an average particle size of a metal fluoride is pulverized to 10 μm or less and mixed with a solvent containing alcohol as a main component. The permanent magnet rotating electric machine according to claim 34 ,
The on-vehicle permanent magnet rotating electric machine, wherein the alcohol is methyl alcohol, ethyl alcohol, n-propyl alcohol or isopropyl alcohol. The phosphate chemical conversion film according to claim 31 contains phosphoric acid, boric acid, and one or more of Mg, Zn, Mn, Cd, Ca, Sr, and Ba. Electric. The phosphate chemical conversion treatment film according to claim 32 is formed from an aqueous solution containing at least one of phosphoric acid, boric acid, Mg, Zn, Mn, Cd, Ca, Sr, and Ba. Permanent magnet rotating electric machine. The phosphate chemical conversion treatment film according to claim 32 contains at least one of phosphoric acid, boric acid, Mg, Zn, Mn, Cd, Ca, Sr, and Ba, and a surfactant and a rust inhibitor. An in-vehicle permanent magnet rotating electrical machine formed of an aqueous solution containing The in-vehicle permanent magnet rotating electric machine, wherein the surfactant according to claim 38 is a perfluoroalkyl-based, alkylbenzenesulfonic acid-based, zwitterionic-based, or polyether-based material. The rust preventive agent according to claim 38 is an on-vehicle permanent magnet rotating electrical machine that is an organic compound containing at least one of nitrogen and sulfur having an isolated couple. The organic compound rust preventive agent containing at least one of nitrogen and sulfur having an isolated couple according to claim 40 is represented by chemical formula 1
(In the formula, X is any one of H, CH ₃ , C ₂ H ₅ , C ₃ H ₇ , NH ₂ , OH, and COOH.) Rotating electric machine. The permanent magnet rotating electric machine according to any one of claims 19 to 30 ,
The permanent magnet compresses rare earth magnetic powder, inserts the rare earth magnetic powder formed by the compression molding into the permanent magnet insertion hole, and adds SiO ₂ to the rare earth magnetic powder inserted into the permanent magnet insertion hole. An in-vehicle permanent magnet rotating electric machine formed by impregnating the above precursor and binding rare earth magnetic powder with a binder mainly composed of SiO ₂ .