JP2008236844A - Rotary electric machine and its manufacturing method and automobile equipped with rotary electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary electric machine employing a magnet produced by binding a magnet material with a binding agent in which the characteristics are improved. <P>SOLUTION: A permanent magnet produced by binding a magnet material with a binding agent the precursor of which exhibits good wettability to the magnet material, is used in a permanent magnet rotary electric machine. A proportion of a magnetic material in the magnet is increased by using a binding agent exhibiting good wettability to the magnet material, and since deterioration in magnetic characteristics of the magnet is reduced as compared with the case where epoxy resin is used as the binding agent, good characteristics is maintained. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotating electrical machine, a method for manufacturing the same, and an automobile including the rotating electrical machine.

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

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

Japanese Patent Laid-Open No. 11-238640

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

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

  The rotating electrical machine of the present invention includes a rotor including a field winding and a claw pole, and a permanent magnet disposed between the claw poles. The permanent magnet is formed by binding magnetic powder with a SiO-based material. It is characterized by being molded.

  The method of manufacturing a rotating electrical machine according to the present invention includes a step of pressure-molding magnetic powder, impregnating the pressure-molded body with a solution of a binder precursor, and manufacturing a permanent magnet. It is characterized by being mounted between the claw magnetic poles of the rotor.

  In addition, in an automobile equipped with the rotating electrical machine of the present invention, a permanent magnet in which magnetic powder is bound with a binder is disposed between the claw magnetic poles of the rotor, and the binder is compressed in a liquid state. It is characterized by being able to penetrate between the magnetic powders.

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

[First embodiment]
Hereinafter, an embodiment of an electric four-wheel drive vehicle equipped with a rotating electrical machine according to the present invention will be described. FIG. 1 is a system configuration diagram showing the configuration of an electric four-wheel drive vehicle according to a first embodiment of the present invention.

In the electric four-wheel drive vehicle of this embodiment, the driving force output from the engine (ENG) 1010 is transmitted to the front wheels WH-FR and WH-FL via the transmission 1012, and the front wheels WH-FR and WH-. Drive FL. The generator 1014 is, for example, a generator that generates a higher voltage, for example, 42V system power, in a completely different system from the 14V system power generator that supplies power to an on-vehicle supplement such as a battery having a nominal voltage of 14V system. The AC power generated by the generator 1014 is smoothed by a smoothing capacitor 1022 after full-wave rectification, supplied to an inverter (INV) 1016, and converted into AC power. This AC power is supplied to an armature winding of an AC motor (synchronous motor) 1100 to drive the synchronous motor 1100. The driving force output from the synchronous motor 1100 is transmitted to the rear wheels WH-RR and WH-RL via the clutch 1018 and the differential gear 1020 to drive the rear wheels WH-RR and WH-RL. A control unit (CU) 1200 controls the field current of the generator 1014 to control the generated power. The control unit (CU) 1200 controls the inverter 1016 to control the electric power supplied to the synchronous motor 1100 to control the driving force of the synchronous motor 1100. Further, the controller clutch 1018 is controlled to be released / engaged. Specifically, the clutch 1018 is engaged from the start to a predetermined vehicle speed (medium speed), and the clutch 1018 is released in a higher speed region so that only the front wheels are driven by the engine 1010. Here, since the inverter 1016 is switched by the control unit 1200 to generate AC power, the voltage at the input of the inverter 1016 pulsates. The smoothing capacitor 1022 functions to smooth the pulsation when the AC power generated by the generator 1014 is full-wave rectified as described above, and to smooth the pulsation of the inverter.

  In a conventional electric four-wheel drive vehicle, a DC motor is used as a motor for driving the rear wheels. Since this DC motor is mounted in the vicinity of the differential gear 1020 and under the vehicle body, the size of the motor that can be mounted is limited. On the other hand, since the output that can be generated with a small DC motor cannot be increased so much, it has been difficult to apply to a vehicle larger than 1 liter class.

  On the other hand, in this embodiment, since an AC motor is used as the motor for driving the rear wheels, the output can be increased as compared with the DC motor, and therefore, there is an effect that can be applied to an automobile having a larger displacement.

  AC motors include induction motors, permanent magnet type synchronous motors, field winding type synchronous motors, etc. In order to cope with high torque and high output, it is particularly necessary to use field winding type synchronous motors. It is effective in the following points.

  That is, the torque at the time of low speed rotation can be increased compared to the induction motor. Further, a permanent magnet type synchronous motor that does not have a field winding requires field weakening control in order to suppress an induced voltage during high-speed rotation. For this reason, when it is attempted to expand the operating range to high speed rotation, the motor efficiency in the high speed operating range is reduced and the internal temperature of the motor is increased. In the field winding type synchronous motor, the induced voltage can be controlled by controlling the disclosed current.

  In addition, as an electric four-wheel drive vehicle, the performance required of an electric motor is that the operation range is wide from a rotation stop state to a high-speed rotation range. For example, when starting on a snowy road, it is desirable to start only by driving the electric motor, and it is desirable to be able to output a large torque in a low-speed rotation range. Moreover, when it is assumed that the four-wheel drive is continued to the middle speed traveling region, it is necessary to make the motor very high. Here, in the permanent magnet synchronous motor, since the magnetic flux of the permanent magnet is damaged, there is a case where the permanent magnet synchronous motor cannot be driven to a necessary high rotation range. Therefore, it is effective to use a field winding type synchronous motor having claw magnetic poles that can be easily controlled as an AC motor used in the electric 4-wheel drive system.

  In the case of a field winding type synchronous motor, it is possible to reduce the magnetic flux by suppressing the field current in the high rotation range, and as a result, the induced voltage can be suppressed to a low level and the motor can be driven to a high rotation.

  Here, the output characteristics of a field winding type synchronous motor and a permanent magnet type synchronous motor having no field winding will be described with reference to FIG.

FIG. 2 is an output characteristic diagram of a field winding type synchronous motor (with a permanent magnet) and a permanent magnet type synchronous motor having no field winding. In FIG. 2, the horizontal axis indicates the rotational speed (min ⁻¹ ), and the vertical axis indicates the torque (Nm).

  As shown in FIG. 2, the maximum rotational speed of the permanent magnet type synchronous motor having no field winding is determined in a range satisfying (maximum rotational speed / maximum rotational speed at maximum torque) ≦ 10. Therefore, the maximum rotation speed of the permanent magnet type synchronous motor having no field winding is lower than the maximum rotation speed of the field winding type synchronous motor. The field winding type synchronous motor is used up to the maximum rotational speed range, and when the rotational speed becomes higher than the maximum rotational speed, the synchronous motor is disconnected from the rear wheel by releasing the clutch arranged between the synchronous motor and the rear wheel. It is.

  As described above, in the field winding type AC synchronous motor, the magnetic flux can be changed by the field current. Therefore, in the electric four-wheel drive system, the field current is changed with respect to the rotation speed of the electric motor, and the magnetic flux generated actively is varied. Thus, using the field winding type synchronous motor, the required motor operating point is driven within the allowable motor current range within the maximum voltage of the system by controlling the field current by the operating point of the motor. Is possible.

  Further, the electric four-wheel drive vehicle of this embodiment shown in FIG. 1 is characterized in that a battery dedicated to the synchronous motor 1100 is not mounted or the capacity may be small. In the case of a normal hybrid vehicle or the like, a battery used as a power generation source or a power recovery source is maintained between the generator and the motor, and the battery has a large capacity. However, it is desirable that the electric four-wheel drive vehicle has a function equivalent to the cost lower than that of the conventional mechanical four-wheel drive vehicle, and it is a system that can cope without using a large-capacity battery.

  Next, the control principle of an electric four-wheel drive vehicle not equipped with a large-capacity battery will be described with reference to FIG.

  FIG. 3 is an energy flow diagram of the electric four-wheel drive vehicle in the present embodiment in which the AC motor is driven using a battery with no large capacity or a very small capacity.

  An electric four-wheel drive vehicle system using an AC motor does not have a large-capacity battery that absorbs and accumulates electric power. Therefore, the electric motor Pg is output from the generator 1014 to which rotational force is applied from the engine and the inverter. It is necessary to perform coordinated control so that the drive energy Pm input to is substantially equal. When the generated energy Pg is larger than the driving energy Pm, surplus power flows into the smoothing capacitor, and the voltage of the DC bus increases. If the voltage of the DC bus exceeds the allowable value, the power element of the capacitor or inverter may be destroyed. Further, when the generated energy Pg is smaller than the drive energy Pm, since the electric power stored in the capacitor is used for driving the motor although it is very small, the voltage decreases, and as a result, the required torque cannot be output.

  In order to solve such a problem, the generator is controlled such that energy Pm necessary for driving the AC motor is output from the generator.

  Further, the inverter 1016 can perform torque control with high response and high accuracy by performing current control in the dq coordinate of the synchronous motor 1100. On the other hand, the power generation control performed on the generator has no choice but to control the field current that has a slow response. The power generation control of the generator needs to be performed with high accuracy in accordance with the behavior of the inverter 1016 and the synchronous motor 1100.

  Therefore, the output voltage of the generator is feedback-controlled so that the voltage Vdc on the input side of the inverter 1016 becomes the voltage command value Vdc * for generating the energy Pm consumed by driving the AC motor. The output current of the generator is feedback-controlled so that the input-side current Idc becomes a current command value Idc * for generating energy Pm consumed by driving the AC motor.

  The fact that a large-capacity battery is not installed does not prevent the installation of a small-capacity battery. Here, for example, a small-capacity battery is a battery with a capacity sufficient to satisfy the maximum output of the motor when used alone with the generator output. is there. Moreover, this system is applicable also to the simple HEV system which has a battery.

  Next, the configuration of the control device for the electric four-wheel drive vehicle according to the present embodiment will be described with reference to FIGS.

  First, the system configuration of the control device for the electric four-wheel drive vehicle according to this embodiment will be described with reference to FIG.

  FIG. 4 is a system configuration diagram showing the configuration of the control device for the electric four-wheel drive vehicle according to the first embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.

The control unit 1200 includes a power generation control unit 1210 and a motor control unit 1220. The configuration and operation of the power generation control unit 1210 will be described later with reference to FIGS. 5 and 6. However, the power generation control unit 1210 generates power so that the voltage Vdc across the capacitor 1022 matches the capacitor voltage command Vdc * output from the motor control unit 1220. The field voltage command C1 (Vgf *) of the field winding of the machine 1014 is feedback-controlled. The field voltage command C1 (Vgf *) is input to a chopper (CH) circuit 1032 that controls the field current of the generator 1014.

The motor control unit 1220 includes a rectangular control unit 1220A and a PWM control unit 1220B. Although the configuration and operation of the motor control unit 1220 will be described later with reference to FIG. 5, the motor torque command Tr * output from the engine control unit 1030, the motor rotation speed detected by the rotation speed sensor provided in the synchronous motor 1100. Based on ωm and the magnetic pole position θ detected by the magnetic pole position sensor provided in the synchronous motor 1100, three-phase AC voltage commands Vu *, Vv *, Vw * supplied to the inverter 1016 are output, and the inverter 1016 is And thereby controlling the AC power supplied to the armature winding of the synchronous motor 1100, thereby controlling the driving force output by the synchronous motor 1100. The driving force output by the synchronous motor 1100 is controlled such that the driving torque of the synchronous motor decreases as the rotational speed of the synchronous motor increases. Further, the motor control unit 1220 outputs a field current command Imf * to the chopper (CH) circuit 1034 that controls the field current of the synchronous motor 1100 and controls the chopper circuit 1034, so that the field of the synchronous motor 1100 is controlled. The current If is controlled.

Field current command Imf * is determined based on torque command Tr * and motor rotation speed ωm in current command calculation unit 1222 shown in FIG. As an example, a field current command Imf * is obtained from the torque command Tr * and the motor rotation speed ωm using a three-dimensional table (map) including the torque command Tr *, the motor rotation speed ωm, and the field current command Imf *. be able to. Basically, since the induced voltage increases as the motor speed increases, the field current command Imf * is operated to decrease. Further, the field current If can be changed in accordance with the torque command. When the field current If is changed according to the magnitude of the torque command, the motor efficiency can be improved with respect to the constant field current. The field current If according to the field current command Imf * is controlled by feedback-controlling the motor field current detection value with respect to the field current command Imf * determined by the current command calculation unit 1222 based on such logic. generate.

  At this time, the output value obtained by performing feedback control calculation of the field current If corresponds to the field voltage command Vgf *, and the field voltage command Vgf * is input to the chopper circuit 1034 to flow the field current If. . Here, the chopper circuit 1034 has been described as an H-bridge circuit. However, since the field current If flows in a constant direction, the object can be achieved even in a circuit in which one switching element is wired in series with the field winding. .

  As described above, the field current command Imf * is changed according to the operating point of the motor, and control is performed so that the actual field current accurately follows the command value. This makes it possible to achieve highly efficient and highly accurate torque control.

The motor control unit 1220 switches between the rectangular wave control unit 1220A and the PWM control unit 1220B according to the motor speed. For example, the stop / low speed range is driven by PWM control, and the medium / high speed range (for example, 5000 rpm or more) is driven by rectangular wave control.

  Next, the configuration of the power generation control unit 1210 in the control device for the electric four-wheel drive vehicle according to the present embodiment will be described with reference to FIGS. 5 and 6.

  FIG. 5 is a block diagram showing the configuration of the control device for the electric four-wheel drive vehicle according to the first embodiment of the present invention. The same reference numerals as those in FIG. 4 indicate the same parts. FIG. 6 is a flowchart showing the operation of the generator control unit in the control device for the electric four-wheel drive vehicle according to the first embodiment of the present invention.

  As shown in FIG. 5, the power generation control unit 1210 includes a subtraction unit 1212, a voltage feedback control unit 1214, and a Duty (C1) calculation unit 1216.

  In step s10 of FIG. 6, the subtraction unit 1212 calculates a deviation ΔVdc from the capacitor voltage command value Vdc * output from the motor control unit 1220 and the capacitor voltage Vdc that is the voltage across the capacitor 22.

  Next, in step s20 of FIG. 6, the voltage feedback control unit 1214 performs a proportional integration (PI) operation on the deviation ΔVdc obtained by the subtraction unit 1212 and outputs a field voltage command Vgf *. The control is PI control, but is not limited to this. Further, when there is a problem in response with only the feedback control system, feed forward compensation may be included.

  In step s30 of FIG. 6, the Duty (C1) calculation unit 1216 obtains the duty C1 (Vgf *) as Vgf * / Vdc from the field voltage command Vgf * output from the voltage feedback control unit 1212, and the duty C1. The (Vgf *) signal is supplied to the field winding of the generator 1014 and is feedback controlled so that the capacitor voltage Vdc, which is the voltage across the capacitor 1022, is positioned at the capacitor voltage command value Vdc *.

  Next, the configuration of the motor control unit 1220 in the control device for the electric four-wheel drive vehicle according to this embodiment will be described with reference to FIGS. 5, 7, and 8.

  As shown in FIG. 5, the motor control unit 1220 includes a current command calculation unit 1222, a voltage command calculation unit 1224, a three-phase voltage command calculation unit 1226, a DC voltage Vdc1 calculation unit 1228, and a capacitor voltage command value Vdc *. A calculation unit 1232 and a PWM / rectangular wave signal processing unit 1234 are provided.

Based on the torque command Tr * from the ECU 30 shown in FIG. 4 and the motor rotation speed ωm detected by the rotation speed sensor provided in the synchronous motor 1100 shown in FIG. Are used to calculate the d-axis current command Id *, the q-axis current command Iq *, and the field current command Imf * for the synchronous motor 1100. The field current command Imf * is a chopper (CH) circuit 1034 that controls the field current of the synchronous motor 1100.
And the field current If of the synchronous motor 1100 is controlled by controlling the chopper circuit 1034.

  The voltage command calculation unit 1224 calculates a d-axis voltage command Vd * and a q-axis voltage command Vq * from the d-axis current command Id * and the q-axis current command Iq * calculated by the current command calculation unit 1222.

  The three-phase voltage command unit 1226 detects the θ detected by the magnetic pole position sensor provided in the synchronous motor 1100 with respect to the d-axis voltage command Vd * and the q-axis voltage command Vq * calculated by the voltage command calculation unit 1224. Are used to calculate AC voltage commands Vu *, Vv *, Vw * for the synchronous motor 1100.

  The PWM / rectangular wave signal processing unit 1234 performs inverter PWM control or rectangular wave control on the inverter 1016 based on the AC voltage commands Vu *, Vv *, and Vw * calculated by the three-phase voltage command unit 1226. A drive signal for the internal switching element is generated and output to the inverter 1016.

  Next, the operation of the DC voltage Vdc1 calculation unit 1228 will be described with reference to FIG.

  FIG. 7 is a flowchart showing the operation of the motor control unit in the control device for the electric four-wheel drive vehicle according to the first embodiment of the present invention.

The DC voltage Vdc1 calculation unit 1228 calculates the output voltage of the generator 1014, that is, the voltage Vdc1 across the capacitor 1022, based on the d-axis voltage command Vd * and the q-axis voltage command Vq * calculated by the voltage command unit 1224. .

In step s100 of FIG. 7, the DC voltage Vdc1 calculation unit 1228 calculates a DC voltage command value Vdc1 based on the d-axis voltage command Vd * and the q-axis voltage command Vq *. The DC voltage Vdc1 calculating unit 1228 calculates the phase voltage V of the electric motor based on the d-axis voltage command Vd * and the q-axis voltage command Vq * by the following equation (1).

V = (√ (vd * ² + Vq * ² )) / √3 (1)
Furthermore, the DC voltage Vdc1 calculating unit 228 calculates the DC voltage command value Vdc1 from the phase voltage V of the motor based on the following equation (2) in the case of PWM control, and in the case of rectangular wave control. , Based on the following equation (3).

Vdc1 = (2√2) · V (2) (2)
Vdc1 = ((2√2) · V) /1.27 (3)
Next, in step s110, the capacitor voltage command value Vdc * calculation unit 1232 extracts an operating point at which the output voltage of the generator becomes Vdc1 at the engine speed ωg using the characteristics of the generator. A reduction mechanism is provided between the engine 1010 and the generator 1014. When the reduction ratio is 2.5, for example, the engine speed ωg = 600 min ⁻¹ corresponds to the generator speed ωg ′ = 1500 min ⁻¹ . To do.

  Here, the power generation characteristics of the generator will be described with reference to FIG.

  FIG. 8 is a characteristic diagram showing the power generation characteristics of the generator.

In FIG. 8, the horizontal axis indicates the output current of the generator, and the vertical axis indicates the output voltage. The output voltage / current of the generator changes as shown in the curve in the figure. At this time, when the generator rotational speed ωg ′ changes (ωg1 ′ <ωg2 ′ <ωg3 ′), the output voltage / current of the generator also changes as shown in the curve in the figure.

  The capacitor voltage command value Vdc * calculation unit 1232 uses the characteristics of the generator shown in FIG. 7, for example, when the engine speed is ωg and the generator speed is ωg2 ′. The operating point at which becomes Vdc1, that is, the point of the current Idc1 is extracted.

  Next, in step s120 of FIG. 7, the capacitor voltage command value Vdc * calculation unit 1232 detects the operating point, that is, when the output voltage of the generator is Vdc1 and the synchronous motor 1100 is driven by the output current Idc1. It is determined whether or not the driving force (torque) of the synchronous motor 1100 satisfies the required power Pm (= motor rotational speed ωm × torque command Tr *). If satisfied, the process proceeds to step s130. If not satisfied, the process proceeds to step s140.

  When the operating point of the generator satisfies the required power, in step s130, the DC voltage Vdc1 calculation unit 1228 causes the synchronous motor 1100 and the generator 1014 to operate most efficiently with respect to the DC voltage command value Vdc1. The voltage command value Vdc2 is recalculated. That is, the motor control unit 1220 has an efficiency map for each operating point (engine speed, voltage, current) of the generator inside, and outputs the required power of the motor that is equal to or higher than the DC voltage command value Vdc1. From the range of possible voltages, the voltage with the maximum efficiency is searched. When voltage command value Vdc2 is calculated, capacitor voltage command value Vdc * calculation unit 1232 outputs voltage command value Vdc * for voltage command value Vdc2 to power generation control unit 1210. The power generation control unit 1210 performs feedback control so that the capacitor voltage Vdc becomes the voltage command value Vdc *.

  If the operating point of the generator does not satisfy the required power, in step s140, the DC voltage Vdc1 calculation unit 228 sets the voltage command value Vdc3 and the torque command value Tr * within a range where necessary power can be obtained. Recalculate. That is, when the generator cannot output the required power of the motor, first, a motor torque command value that can be output with the maximum power of the generator at the current engine rotation is calculated. Then, a DC voltage command value necessary for the torque is calculated. However, since the calculated DC voltage may be lower than the induced voltage generated by the electric motor, in such a case, the motor torque command value is further lowered, and the DC voltage and the motor torque that can be actually output are finally determined. The torque command value Tr * is sent to the current command calculation unit 1222, and again the three-phase voltage command value Vu * is obtained by the current command calculation unit 1222, the voltage command calculation unit 1224, and the three-phase voltage command calculation unit 1226. , Vv *, Vw * are calculated. Capacitor voltage command value Vdc * calculation unit 1232 outputs voltage command value Vdc * for voltage command value Vdc3 to power generation control unit 1210. The power generation control unit 1210 performs feedback control so that the capacitor voltage Vdc becomes the voltage command value Vdc *.

  Here, the control operation by the control device for the electric four-wheel drive vehicle according to the present embodiment will be described with reference to FIG.

  FIG. 9 is a timing chart showing a control operation by the control device for the electric four-wheel drive vehicle according to the first embodiment of the present invention. FIG. 9A shows the engine speed ωg, and FIG. 9B shows the motor speed ωm. FIG. 9C shows the motor torque Tm, and FIG. 9D shows the required capacitor voltage Vdc. The horizontal axis is time (sec).

  As shown in FIG. 9 (A), the engine speed ωg increases and decreases as the speed is changed to 1st, 2nd, and 3rd after idling. On the other hand, as shown in FIG. 9B, the motor rotation speed ωm increases and decreases monotonously. Here, as shown in FIG. 9C, during idling, since the electric four-wheel drive vehicle has not started yet, the required motor torque Tm may be small, but at low speed immediately after starting, it is large. Torque is needed. As the vehicle speed increases, the necessary motor torque Tm can be reduced.

  Therefore, as shown in FIG. 9D, during idling (in the vicinity of X1 in the figure), the required capacitor voltage Vdc is lowered and, for example, the generator is operated near point C in FIG. In the low engine rotation range at the time of start (in the vicinity of X2 in the figure), the generator is operated in the vicinity of point B in FIG. Further, when the engine speed increases (in the vicinity of X3 in the figure), the necessary capacitor voltage Vdc is increased, for example, the generator is operated near the point A in FIG. Thus, the required driving force can be efficiently obtained by adjusting the required Vdc with respect to the engine speed.

  Next, the configuration of the field winding type synchronous motor used in the electric four-wheel drive vehicle according to the embodiment of the present invention will be described with reference to FIG.

  First, the overall configuration of the first field winding type synchronous motor used in the electric four-wheel drive vehicle according to one embodiment of the present invention will be described with reference to FIG. FIG. 10 is a cross-sectional view showing the overall configuration of a permanent magnet rotating electric machine having field windings used in the electric four-drive vehicle.

  A permanent magnet type synchronous rotating electrical machine 1100 having field windings is a tandem field magnet in which two rotors instructed to rotate on the inner peripheral side of a stator are provided on the same shaft (output shaft). A permanent magnet rotating electric machine having windings.

  The housing 1102 includes a bearing bracket 1108 to which the rear side bearing 1109b is fixed, and a resolver bracket 1122 in which a magnetic pole position detector 1120 (for example, a resolver) is accommodated. In the bearing bracket 1108, a bracket and a housing for housing the front side bearing 1109a are integrally formed. A shaft 1115 is supported at the center of each bracket via a front bearing 1109a and a rear bearing 1109b. A pair of slip rings 1019 is attached to one end of the shaft 1115.

A stator 1103 and a rotor 1110 are provided inside the housing 1102. The stator 1103 includes a stator core 1104 and a stator winding 1106. A stator core 1104 is disposed in the housing 1102 by fitting. A stator winding 1106 is housed in a slot of the stator core 1104.

Inside the stator core 1104, a rotor 1110 is rotatably supported by bearings 1109a and 1109b via a mechanical gap (air gap length). The rotor 1110 includes claw magnetic poles 1111a, 1112a, 1111b, and 1112b, field windings 1113a and 1113b, and permanent magnets 1130a and 1130b. The claw magnetic poles 1111a and 1112a, the field winding 1113a, and the permanent magnet 1130a constitute a first rotor. The claw magnetic poles 1111b and 1112b, the field winding 1113b, and the permanent magnet 1130b constitute a second rotor. A pair of claw magnetic poles 1111a,
1112a is arranged so that each claw portion is positioned between the claw portions facing each other, and the pair of claw magnetic poles 1111b and 1112b are also positioned between the claw portions facing each claw portion. Are arranged to be. A bobbin 1114a is incorporated between the claw magnetic poles 1111a and 1112a, and a bobbin 1114b is incorporated between the claw magnetic poles 1111b and 1112b. Field windings 1113a and 1113b are wound around the bobbins 1114a and 1114b, respectively. A plurality of permanent magnets 1130a and 1130b are mounted between the pair of claw magnetic poles 1111a and 1112a and the claw magnetic poles 1111b and 1112b. A brush 1118 is slidably attached to each of the two slip rings 1119, and a direct current from the battery is supplied to the field windings 1113 a and 1113 b via the slip rings 1119.

The claw magnetic poles 1111 a and 1112 a are alternately excited with N and S poles in the circumferential direction by the field winding 1113 a via the brush 1118. The claw magnetic poles 1111 b and 1112 b are also alternately excited with N and S poles in the circumferential direction by the field winding 1113 b via the brush 1118. The polarity of the tandem claw poles is the same on the side where both claw poles are in contact. The polarities of the permanent magnets 1130a and 1130b are magnetized to the same polarity as the polarity of the surface on which the polarity of the claw magnetic pole is determined by the excitation of the field winding.

  When one of the tandem configurations of the claw magnetic pole rotor is shifted in the circumferential direction as a reference for the magnetic pole position detector 1120, a waveform obtained by adjusting the reference of the position detector at the center of both or by synthesizing the induced voltages of the two. To match.

  A resolver stator 1120 is accommodated in the resolver bracket 1122. A resolver rotor 1121 is attached to an end portion of the shaft 1115 with a mechanical gap (air gap length) with respect to the resolver stator 1120. A cover 1123 is attached to the resolver bracket 1122, and the position of the resolver stator 1120 can be adjusted by removing the cover 1123.

  Although the permanent magnet type synchronous rotating electrical machine 1100 has been described with reference to FIG. 10, the generator 1014 has a substantially similar structure, and has a permanent magnet similarly to the structure of the permanent magnet type synchronous rotating electrical machine 1100. By using a permanent magnet using a SiO-based binder described in the following embodiment as a permanent magnet used in the permanent magnet type synchronous rotating electric machine 1100 or the generator 1014, a great effect in productivity and the like can be obtained. is there. The permanent magnet synchronous rotating electric machine 1100 and the permanent magnets used in the generator 1014 have the same configuration, operation, and effect as described below. Therefore, the permanent magnet synchronous rotating electric machine 1100 will be described using the permanent magnet as a representative. To do. This description can be applied to the magnet of the generator 1014 almost as it is.

  Next, the permanent magnets 1130a and 1130b will be described. Before describing the permanent magnet of the present example, the conventional permanent magnet, that is, the conventional permanent magnet is not specialized so that the permanent magnet of the embodiment of the present invention can be compared with the conventional permanent magnet. The sintered magnet and bond magnet used in the permanent magnet type rotating electrical machine are shown below.

  High temperature treatment is indispensable for the production method of sintered magnets, so that production costs including equipment costs are high. In addition, in order to obtain parts with accurate dimensions, the shape and dimensions after the sintering process change due to thermal shrinkage, etc., due to the sintering process in which the magnet material is heated to a high temperature. In the molding process after the sintering process, a molding operation including a large amount of cutting was required to obtain dimensional accuracy. This has increased the cost of the magnet motor, and it has been difficult to obtain a motor that is inexpensive and has good controllability.

  The bond magnet is a magnet in which a thermosetting epoxy resin and a magnet material are mixed and the mixture is molded and manufactured, that is, a magnet material is bonded with an epoxy resin. Since such a bond magnet has a low energy density, it is not often used for large capacity and large torque applications, and is used for small fan motors and the like. However, in a magnet using an epoxy resin as a binder, a magnet is manufactured by compression molding a mixture of a magnet material and an epoxy resin. The magnet which adheres a magnet material with an epoxy resin has a problem that the ratio of the epoxy resin material to the magnet material is increased, the ratio of the magnet material used for the magnet is decreased, and the magnetic properties are deteriorated. For this reason, when it is going to be used for a pure permanent magnet type rotating electrical machine using the magnet, there is a problem that the characteristics of the rotating electrical machine are remarkably deteriorated.

  For example, since the material itself is demagnetized at a high temperature, the rotating electrical machine cannot be set to a high temperature specification, and since the energy density is low, the energy density of the magnetic circuit cannot be increased and the size cannot be sufficiently reduced. There were problems such as being unable to be used for automobiles for the above two reasons.

  As described above, in order to make such a shape with a sintered magnet, surface processing is required, which increases the cost. Actually, since the sintered magnet is sintered at 1000 ° C. or higher, it is necessary to correct deformation due to thermal shrinkage, and it is indispensable to process it later. In addition, the bonded magnet bonded with an organic material has no thermal durability exceeding 150 ° C. necessary for use in an automobile.

On the other hand, the permanent magnet of this embodiment uses a magnetic powder that is formed by binding a magnetic powder with an inorganic material such as SiO ₂ that is a SiO-based material. For this reason, since the heat resistance of a binder is as high as 200 degreeC or more, the magnetic flux density of the gap which a magnet makes becomes a sine wave shape, and a harmonic component can be reduced. Thus, the cogging torque, torque ripple, and induced voltage waveform can be made very smooth, and high-precision control can be performed as a rotating machine. The details of the permanent magnet of this embodiment will be described in detail below.

The permanent magnets 1130a and 1130b of the present embodiment have a structure in which a neodymium (Nd) powder of a rare earth material, which is a magnet material, is bound with a binder having a property that the neodymium (Nd) and a precursor have good affinity. I am doing. Here, the precursor having excellent affinity is, for example, alkoxysiloxane or alkoxysilane which is a precursor of SiO ₂ . The neodymium (Nd) powder has a plate-like shape, and the thickness in the X-axis and Y-axis directions is several times larger than the value in the Z-axis direction, which is the height direction. I am doing. The size of the neodymium (Nd) powder in the X-axis or Y-axis direction is preferably large. For example, the size of the powder in the X-axis or Y-axis direction is 45.
Residual characteristics are improved by using powders with a size of μm or more. Although the powder of neodymium (Nd) breaks down during molding, it is difficult to mix small powders, but more than half of the powders are desirably large powders of 45 μm or more, and A more preferable result is obtained when 70% or more is a powder having a size of 45 μm or more. Even more preferable results can be obtained when 90% or more is a powder having a size of 45 μm or more. If neodymium (Nd) further contains dysprosium (Dy), the characteristics are improved. By including this dysprosium (Dy), good magnetic properties are maintained even if the temperature of the rotating electrical machine rises. The content of dysprosium (Dy) is about several percent, and at most 10%.

  Next, an example of a manufacturing process of the permanent magnets 1130a and 1130b 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.

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

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

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

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

  By impregnating a precursor solution of a binder 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

Step 25 is a step of fixing the magnet material with the binder by heat-treating the impregnated compression molded body. As described in detail below, a good magnet can be obtained by binding a magnet material using SiO ₂ as a SiO-based material as a binder. As will be described in detail below, the 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 relationship between the shape and dimensions of the manufactured magnets. High accuracy is maintained for the compression-molded shape and dimensions.

[Permanent magnet binder]
The binder precursor solution used in the step 20 has an alkoxysiloxane and an alkoxysilane, which are SiO ₂ precursors, and has terminal groups and side chains as shown in Chemical Formula 1 and Chemical Formula 2. It has a compound having an alkoxy group.

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

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

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

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

  Next, another manufacturing method of the permanent magnets 254 and 256 will be described. Another embodiment of the magnet manufacturing process according to the present invention is shown in FIGS. The embodiment shown in FIG. 12 is different from the process shown in FIG. 11 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. 13 is different in that a compression-molded magnet is attached to the rotor and thereafter a treatment of impregnating the binder is performed.

  In FIG. 12, the same process numbers as those in FIG. 11 indicate substantially the same processing contents. In step 10, a powdered magnet material is generated, and an electrical insulating film is formed on the surface of each powder of the magnet material generated in step 12. It is desirable to make an electrical insulating layer as uniform as possible on the entire surface of the magnetic powder as much as possible, and a specific treatment method will be described later. When the manufactured magnet is used for a rotating electrical machine, it is used in an alternating magnetic field as described above. The magnetic flux passing through the magnet changes periodically, and an eddy current is generated in the magnet due to the change of the magnetic flux. This eddy current has a problem of lowering the efficiency of the rotating electrical machine, and there is a risk of increasing heat generation in the magnet due to the eddy current. By covering the surface of each powder in the magnet material with an insulating layer, this eddy current can be suppressed, the efficiency of the rotating machine can be suppressed, and the heat generated by the magnet can be suppressed.

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

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

  The addition amount of the phosphating solution depends on the average particle size of the rare earth magnet magnetic powder. When the average particle 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. When the amount is more than 300 mL, the insulating film on the surface of the magnetic powder becomes too thick, and rust is easily generated, so that the magnetic flux density at the time of magnet production is reduced. As a result, the amount of rust generated increases, which may cause deterioration of the magnet characteristics.

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

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

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

  In the process of FIG. 12, in step 12, an insulating film is formed on the surface of each powder in the rare earth magnet material, and in step 15, the magnet material is compression molded to form a porous magnet. Thereafter, the precursor of the binder is impregnated in step 20 as in FIG. 11, and the precursor is cured in step 25 to fix 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. 13 shows that a porous magnet compression-molded before the binder impregnation step is inserted into a desired magnet insertion frame (not shown) surrounded by adjacent claw magnetic poles and field windings of the rotor. Then, the binder precursor is poured into a magnet insertion frame 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 a magnet insertion frame provided on the rotor core, and a SiO ₂ precursor solution is poured into the rotor magnet insertion frame 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.

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

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

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

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

1) 5 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, average is 4), water 0.96 mL, dehydrated methyl alcohol 95 mL, dibutyltin dilaurate 0 .05 mL was mixed and left at a temperature of 25 ° C. for 2 days and nights.

2) 25 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, average 4), water 4.8 mL, dehydrated methyl alcohol 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 mixed It was left at a temperature of 25 ° C. for 4 hours.

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

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

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

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

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

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

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

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

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

FIG. 14 shows an example of SEM observation results of the cross-sectional portion of a compression molded test piece having a length of 10 mm, a width of 10 mm, and a thickness of 5 mm produced in (5). 14A is a secondary electron image, FIG. 14B is an oxygen surface analysis image, and FIG. 14C 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 value of residual magnetic flux density and coercivity and SiO ₂ before impregnated with the molded body after SiO ₂ infiltration and heating were almost the same. Further, the thermal demagnetization factor after 1 hour of holding at 200 ° C. in the atmosphere is 3.0% for the SiO ₂ impregnated bonded magnet, which is smaller than the thermal demagnetization factor (5%) without SiO ₂ impregnation. Further, the irreversible thermal demagnetization rate 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, thereby preventing corrosion such as oxidation and reducing the irreversible thermal demagnetization rate. That is, since the surface of the powder including cracks is protected by the impregnation treatment with the SiO ₂ precursor, corrosion such as oxidation is suppressed, and the irreversible thermal demagnetization rate is reduced. In addition to suppressing irreversible thermal demagnetization, the impregnated magnet has obtained less demagnetization results in the PCT test and the salt spray test.

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

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

The bending strength of the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (7) is ₂ MPa or less before the SiO ₂ impregnation, but 30 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 molded body having a bending strength of 100 MPa or more.

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

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

  Table 2 summarizes the magnet characteristics when binders 1) to 3) are used for this example and (Example 2) to (Example 5) described later.

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

1) 25 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, average 4), water 0.96 mL, dehydrated methyl alcohol 75 mL, dibutyltin dilaurate 0 .05 mL was mixed and left at a temperature of 25 ° C. for 2 days and nights.

2) 25 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, average 4), water 4.8 mL, dehydrated methyl alcohol 75 mL, dibutyltin dilaurate 0 .05 mL was mixed and left at a temperature of 25 ° C. for 2 days and nights.

3) 100 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, average is 4), 9.6 mL of water, 75 mL of dehydrated methyl alcohol, dibutyltin dilaurate 0 .05 mL was mixed and left at a temperature of 25 ° C. for 2 days and nights.

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

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

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

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

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

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

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

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

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

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

The bending strength of the compression molded test piece of 15 mm length, 10 mm width and 2 mm thickness produced in (7) is ₂ MPa or less before the SiO ₂ impregnation, but 70 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 molded body having a bending strength of 100 MPa or more.

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

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

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

1) 25 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) —CH ₃ , 5.9 mL of water, 75 mL of dehydrated methyl alcohol, and 0.05 mL of dibutyltin dilaurate were mixed, and the temperature was kept at 25 ° C. for 2 days and nights. Left alone.

2) 25 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, average 4), water 4.8 mL, dehydrated methyl alcohol 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 viscosities of the SiO ₂ precursor solutions 1) to 3) were measured at a temperature of 30 ° C. using an Ostwald viscometer.

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

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

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

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

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

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

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

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

Regarding the magnetic properties of the compression molded test piece of 10 mm length, 10 mm width and 5 mm thickness produced in (5), the residual magnetic flux density can be improved by 20-30% compared to the resin-containing bond magnet (Comparative Example 1). , and the demagnetization curve was measured at 20 ° C., the value of residual magnetic flux density and coercivity and SiO ₂ before impregnated with the molded body after SiO ₂ infiltration and heating were almost the same. Further, less than 200 ° C. (heat demagnetization rate no SiO ₂ infiltration and heat demagnetization after the atmosphere held for 1 hour 3.0% of SiO ₂ infiltrated bond magnet (5%). Further, the irreversible heat after demagnetizing be 200 ° C. 1 hour in air retention, less than the value of almost 3% when no SiO ₂ infiltration is less than 1% after SiO ₂ infiltration and heating. it suppress deterioration SiO ₂ is due to oxidation of the magnetic powder It is because it is doing.

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

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

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

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

1) 25 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) —CH ₃ , 5.9 mL of water, 75 mL of dehydrated methyl alcohol, and 0.05 mL of dibutyltin dilaurate were mixed, and the temperature was kept at 25 ° C. for 2 days and nights. Left alone.

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

_{3) n-C 3 H 7} O- (Si (C 2 H 5 O) 2 -O) -n-C 3 a H ₇ 25 mL, water 3.4 mL, dehydrated 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 viscosities of the SiO ₂ precursor solutions 1) to 3) were measured at a temperature of 30 ° C. using an Ostwald viscometer.

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

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

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

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

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

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

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

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

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

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

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

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

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

1) 25 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, average is 4), 9.6 mL of water, 75 mL of dehydrated methyl alcohol, dibutyltin dilaurate 0 .05 mL was mixed and allowed to stand at a temperature of 25 ° C. overnight.

2) 25 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, average is 4), 9.6 mL of water, 75 mL of dehydrated methyl alcohol, dibutyltin dilaurate 0 .05 mL was mixed and left at a temperature of 25 ° C. for 2 days and nights.

3) 100 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, average is 4), 9.6 mL of water, 75 mL of dehydrated methyl alcohol, dibutyltin dilaurate 0 .05 mL was mixed and left at a temperature of 25 ° C. for 4 days and nights.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The SiO ₂ precursor as a binder includes 25 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, average is 4), 4.8 mL of water, dehydration A solution in which 75 mL of methyl alcohol and 0.05 mL of dibutyltin dilaurate were mixed and allowed to stand at a temperature of 25 ° C. for 2 days was used.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The SiO ₂ precursor as a binder includes 25 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, average is 4), 4.8 mL of water, dehydration A solution in which 75 mL of methyl alcohol and 0.05 mL of dibutyltin dilaurate were mixed and allowed to stand at a temperature of 25 ° C. for 2 days was used.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

(1) 10 mL of DyF ₃ coat film forming solution was added to 100 g of magnetic powder obtained by pulverizing a 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 rare earth magnet magnetic powder that had been subjected to the DyF ₃ coat film forming process of (1) above under a reduced pressure of 2 to 5 torr.

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

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

The SiO ₂ precursor as a binder includes 25 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, average is 4), 4.8 mL of water, dehydration A solution in which 75 mL of methyl alcohol and 0.05 mL of dibutyltin dilaurate were mixed and allowed to stand 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. Also, a compression molded test piece having a length of 15 mm, a width of 10 mm, and a thickness of 2 mm was prepared for strength measurement.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The SiO ₂ precursor, which is a binder, includes 25 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, 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 allowed to stand at a temperature of 25 ° C. for 2 days was used.

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

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

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

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

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

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

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

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

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

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

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

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

[Example 10 of permanent magnet]
In this example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used for the rare earth magnet magnetic powder. The treatment liquid for forming the phosphate chemical conversion film was prepared as follows. 20 g of phosphoric acid, 4 g of boric acid and 4 g of MgO as a metal oxide were dissolved in 1 L 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, and the concentration was added to be 0.01 to 0.5 mol / L. The process of forming the phosphate chemical conversion film on the magnetic powder of Nd ₂ Fe ₁₄ B was carried out by the following method.

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

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

The SiO ₂ precursor, which is a binder, includes 25 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, 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 allowed to stand at a temperature of 25 ° C. for 2 days was used.

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

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

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

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

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

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

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

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

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

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

[Example 11 of permanent magnet]
In this example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used for the rare earth magnet magnetic powder. The treatment liquid for forming the phosphate chemical conversion film was prepared as follows. 20 g of phosphoric acid, 4 g of boric acid and 4 g of MgO as a metal oxide were dissolved in 1 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 added to a concentration of 0.01 to 1 wt%. The process of forming the phosphate chemical conversion film on the magnetic powder of Nd ₂ Fe ₁₄ B was carried out by the following method.

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

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

The SiO ₂ precursor, which is a binder, includes 25 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, 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 allowed to stand at a temperature of 25 ° C. for 2 days was used.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The SiO ₂ precursor, which is a binder, includes 25 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, 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 allowed to stand at a temperature of 25 ° C. for 2 days was used.

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

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

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

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

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

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

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

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

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

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

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

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

[Comparative example 1 of permanent magnet]
In this comparative example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] 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 rare earth magnet magnetic powder produced in (1) above and a compound of resin were loaded into a mold and subjected to heat compression molding at 80 ° C. in an inert gas atmosphere under a molding pressure of 16 t / cm ² . . The produced magnet is 10 mm long, 10 mm wide and 5 mm thick for measuring magnetic properties, and 15 mm long, 10 mm wide and 2 mm thick for measuring strength.

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

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

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

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

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

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

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

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

  In addition, in this comparative example, the evaluation result of the epoxy resin containing 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 of permanent magnet]
In this comparative example, magnetic powder obtained by pulverizing an NdFeB-based ribbon similar to [Embodiment 1 of permanent magnet] was used for the rare earth magnet magnetic powder.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

1) 25 mL of CH ₃ O— (Si (CH ₃ O) ₂ —O) _m —CH ₃ (m is 3 to 5, average is 4), water 0.19 mL, dehydrated methyl alcohol 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 24 mL, dried ethyl alcohol 75 mL, dibutyltin dilaurate 0.05mL And left at a temperature of 25 ° C. for 2 days and nights.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  (1) A salt having high solubility in water, for example, Nd acetate in the case of Nd, or 4 g of 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% was gradually added in an amount equivalent to the chemical reaction for producing NdF ₃ .

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

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

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

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

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

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

In the case of NdF ₃ coat film forming process: NdF ₃ concentration 1 g / 10 mL translucent sol solution (1) 15 mL of NdF ₃ coat film forming treatment liquid is added to 100 g of magnetic powder obtained by pulverizing NdFeB-based ribbon. 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) above under a reduced pressure of 2 to 5 torr.

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

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

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

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

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

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

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

しかしながら、（７）で作製した縦１５mm，横１０mm，厚さ２mmの圧縮成形試験片の曲げ強度に関しては本比較例ではＳｉＯ₂ 含浸を実施していないため、２.９ＭＰａ という値となり、エポキシ系ボンド磁石と比較して１／１５程度の値となった。

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The viscosity of the binder solution depends on the size of the magnet, but when the thickness of the compression molded body is 5 mm or less and the gap between the magnetic powder and the magnetic powder is about 1 μm, the viscosity of the binder solution is about 100 mPa · s. It is possible to introduce the binder solution into the gap between the magnetic powders up to the center of the compression molded body. When the thickness of the compression molded body is 5 mm or more and the gap between the magnetic powder and the magnetic powder is about 1 μm, for example, in the compression molded body having a thickness of about 30 mm, the binder solution is introduced to the center of the compression molded body When the viscosity of the binder solution is about 100 mPa · s, the viscosity of the binder solution is 20 mPa · s or less, preferably 10 mPa · s or less. This is a viscosity that is one digit or more lower than that of a normal resin. For that purpose, it is necessary to control the hydrolysis amount of the alkoxy group in the alkoxysiloxane which is the precursor of SiO ₂ and to suppress the molecular weight of the alkoxysiloxane. That is, when an alkoxy group is hydrolyzed, a silanol group is generated. The silanol group easily undergoes a dehydration condensation reaction, and the dehydration condensation reaction means an increase in the molecular weight of the alkoxysiloxane. Further, since silanol groups generate hydrogen bonds with each other, the viscosity of the alkoxysiloxane solution that is the precursor of SiO ₂ increases. Specifically, the amount of water added to the hydrolysis reaction equivalent of alkoxysiloxane and the hydrolysis reaction conditions are controlled. As the solvent used for the binder solution, it is desirable to use alcohol because the alkoxy group in alkoxysiloxane has a fast dissociation reaction. 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.

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

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

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

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

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

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

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

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

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

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

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

Next, the function and effect of the first embodiment will be described below. The magnets used in the permanent magnet type synchronous rotating electrical machine 1100 and the generator 1014 shown in FIG. 1 have the above-described structure, that is, a powder magnetic material and a binder precursor having good wettability are used as magnets. Producing magnets by impregnation has at least one or more of the following effects. As described above, SiO ₂ is most suitable as a binder for the powder magnetic material and the precursor having good wettability.

Since SiO ₂ is used as a binder for the magnetic material of the powder and the precursor with good wettability, the surface of the magnetic material powder is covered with the binder precursor to form a film of the magnetic material powder. The body can be settled strongly. As a result, many magnetic material powders can be settled with a small amount of binder precursor, and sufficient binding force can be obtained in the completed permanent magnet even though the ratio of the binder to the magnetic material powder is small. effective. The finished magnet has good magnetic properties.

  Further, the magnetic material powder is compressed and formed in step 15 of FIGS. 11, 12, and 13 to be arranged in layers as shown in FIG. The magnet material powder is thin and has a wide shape. By compressing the powder of this shape, a laminated structure is formed in which the powders are stacked in the thin direction. Since the precursor of the SiO-based binder has good wettability with the powder of the magnet material, the precursor of the SiO-based binder enters between the powder layers, and the surface of the powder between the powder layers. It exists as a thin film in an amorphous state so as to cover the film, and exhibits a strong binding action when the precursor is chemically changed. Therefore, a magnet with sufficient strength can be obtained with a small amount of binder with respect to the magnet material, and a magnet with good characteristics can be obtained.

  As described above, the structure enters the gap between the magnet materials, and the film-like binder is present in an amorphous state between the layers of the magnet materials, so that the electrical resistance is increased. The conventional heat-sintered rare earth magnet has a small electric resistance and a large eddy current flows inside, causing the magnet to generate heat. However, the magnet of this embodiment has a large electric resistance and reduces the eddy current of the magnet. There is an effect that can be done. In particular, generators and electric motors for driving automobiles have a high rotational speed, and eddy currents are a problem.

  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.

  Further, since it is not a magnet using an epoxy resin commonly called a bond magnet, it is possible to obtain a rotating electrical machine having a large energy density, inexpensive and relatively good characteristics.

  After the magnet is molded with the magnet material, the binder can be cured at a relatively low temperature, and the shape and dimensions of the molded magnet material are small. 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 portion of the adhesive, so that the process is easy. Since the conventional sintered magnet is heated to a high temperature for sintering, it shrinks in the process of lowering the temperature thereafter, and the shape of the magnet material changes. Therefore, in the conventional sintered magnet, it has been necessary to spend a lot of time for cutting for adjusting the shape and dimensions of the magnet after the sintering process. In the above-described embodiment, a necessary magnet shape can be obtained with extremely few cutting processes and, in some cases, without a cutting process.

  As described above, since the molding shape of the magnet material hardly changes during the subsequent impregnation or curing process of the binder, it is possible to manufacture the magnet while maintaining the curved shape of the magnet material with high accuracy by pressing or the like. It is. 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.

  Sintered rare earth magnets have low electrical resistance and large loss and heat generation due to eddy currents. When a SiO-based binder is used, a film is formed between the rare earth magnetic powders so that the binder enters. For this reason, the internal resistance of a magnet becomes high and the eddy current inside a magnet at the time of being used for a rotary electric machine is suppressed. For example, the internal resistance of the magnet is five to several tens of times that of a sintered rare earth magnet, and the eddy current is reduced by increasing the resistance value. Further, in the above embodiment, an inorganic insulating film is formed on the surface of the powder magnet, and magnetic powder coated with this insulating film can be used. Therefore, the eddy current can be made extremely small, and eddy current loss and heat generation of the magnet can be greatly reduced. . Among rotating electrical machines for automobiles, the rotating electrical machine may be used in an environment exceeding 100 degrees, and it is necessary to suppress heat generation due to eddy current in the magnet to a low level. In the above-described embodiment, since the electric resistance can be increased, the heat generation of the magnet can be reduced. Further, the loss of the rotating electrical machine can be reduced correspondingly, and the efficiency is improved.

[Second Embodiment]
Next, a second embodiment in which the rotating electrical machine of the present invention is applied to a generator will be described with reference to FIG. FIG. 16 shows a case where a permanent magnet is employed in an AC generator for a vehicle, and has substantially the same structure as the generator 1014 shown in FIGS. First, the configuration will be described. A vehicular AC generator 2500 has a pulley 2203 attached to a shaft, and the pulley 2203 is connected to a crank pulley of an engine by a belt. A rotor 1110 is disposed at the center of the shaft. The rotor 1110 includes a claw magnetic pole 1111 a and a field winding 1113. A cooling fan 2103 is disposed on the opposite side of the rotor 1110 from the pulley. This cooling fan 2103 has a structure larger than the outer diameter of the rotor 1110, and has a structure that cannot be inserted and removed with a continuous stator core as in the prior art. The rotor 1110 is supported on the bracket by bearings 1109a and 1109b. The bracket has a structure divided into two parts, and includes a pulley-side front bracket 2212 and a rear bracket 2205. A stator 1103 is disposed between these brackets, and the stator 1103 is magnetically coupled to the rotor 1110 via a gap. The stator 1103 is composed of two sets of magnetic poles and a stator winding 700. Further, a slip ring 1119 for passing a direct current to the field winding 1113 is attached to the rotor 1110, and power is supplied from a brush 1118 provided on the rear bracket 2205. The stator 1103 is composed of three-phase windings, and each winding is connected to a rectifier circuit 2211. The negative side of the rectifier circuit 2211 is connected to the main body of the vehicle alternator 2500, and the positive side is connected to a terminal 2206, which is connected to a battery (not shown). These rectifier circuit 2211, brush 1118 and the like are protected by a rear cover 2210.

  Next, the power generation operation will be described. Since the rotation of the engine and the pulley 2203 rotate in conjunction with each other, when a field current is supplied to the field winding 1113 disposed at the center of the rotor 1110, the claw magnetic pole 1111 is magnetized and moves in the circumferential direction. N pole and S pole are made alternately. Specifically, a field current is supplied to the field winding 1113b via the brush 1118, and the claw magnetic poles 1111a and 1112a are excited by this field current, and N pole and S pole magnetic poles are alternately arranged in the circumferential direction. Become. The permanent magnet 1130a is magnetized so that the polarity of the claw magnetic poles excited by the field winding 1113b and the polarity of the claw magnetic poles excited by the permanent magnet 1130a are the same. An alternating magnetic field is generated in the stator 1103 facing the claw magnetic pole 1111 as the rotor 1110 rotates.

The permanent magnet 1130a uses the above-mentioned magnet using a binder of a precursor having excellent wettability with a rare earth magnet material, preferably SiO ₂ as a binder.

  Since the stator 1103 has three-phase windings, a three-phase induced voltage is generated. A power generation operation is performed at a rotational speed at which the induced voltage is higher than that of a battery (not shown) connected to the terminal 2206 after being converted into a DC voltage by the rectifier circuit 2211. The magnitude of the three-phase induced voltage varies as a function of the field current and the rotor speed, but the voltage supplied to the connected battery can be considered to be substantially constant (strictly speaking, the battery Although the supply target voltage is controlled to be different depending on the state and the load state), it is necessary to control the field current according to the rotational speed. The voltage control circuit is built in the rectifier circuit 2211.

Next, operational effects of the second embodiment will be described below. In FIG. 16, the permanent magnet 1130a uses the above-mentioned magnet using a binder of a rare earth magnet material and a precursor having excellent wettability, preferably SiO ₂ as a binder. In addition to the effects described above, the following effects are also obtained.

  Since it is not a magnet using an epoxy resin commonly called a bond magnet, the temperature characteristic of the magnet is superior to that of the bond magnet, so that it can be used even in a high temperature environment near the engine.

  Sintered rare earth magnets have low electrical resistance and large loss and heat generation due to eddy currents. The magnet can form an insulating coating on the surface of the powder magnet, and the eddy current loss and heat generation of the magnet can be greatly reduced. Among rotating electrical machines for automobiles, the rotating electrical machine may be used in an environment exceeding 100 degrees, and it is necessary to suppress heat generation due to eddy current in the magnet to a low level. In the above-described embodiment, since the electric resistance can be increased, the heat generation of the magnet can be reduced. Therefore, the eddy current loss generated in the permanent magnet when the generator rotates at high speed can be reduced, and the power generation characteristics at high speed rotation can be improved.

[Third embodiment]
Next, a third embodiment of the rotating electrical machine will be described with reference to FIG. FIG. 17 shows a third embodiment relating to the generator 1014 and AC motor 1100 described with reference to FIGS. 1 and 10, and further to the vehicle AC generator 2500 shown in FIG.

  The rotor of the third embodiment shown in FIG. 17 is basically the same material as the permanent magnet 1130a provided on the rotor 1110, but the magnet shape is different. In the magnet using the SiO-based binder manufactured as described above, as shown in FIG. 17, the space between the claw magnetic pole 1111a and the claw magnetic pole 1112a adjacent to each other and the space between the field winding 1113a are filled. Such a shape and a shape divided for each pole can be easily manufactured.

Next, details of the permanent magnet 1130a of the third embodiment will be described with reference to FIG. The permanent magnet 1130a is independently provided between the claw magnetic poles 1111a and 1112a. For this reason, a plurality of permanent magnets 1130a are arranged in the circumferential direction. One of them has thin portions extending inward in the circumferential direction of the claw magnetic poles 1111a and 1112a, and the thin portions are shaped along the claw magnetic poles 1111a and 1112a. That is, the thin portion is formed in a shape having an inclined surface that is thin on one end side in the axial direction and thick on the other end side in the axial direction. The curved surface shape is an arc shape along the inner peripheral surface of 1112a. Further, the field winding 1113a is arranged on the inner peripheral side of the thin portion, and the inner peripheral side of the thin portion is also curved along the curved surface of the outer periphery of the field winding 1113a. Both of the inner and outer circumferences are curved surfaces curved in the rotation direction of the rotor 1110. The permanent magnet 1130a includes claw magnetic poles 1111a,
It arrange | positions so that it may become a symmetrical shape on the circumferential direction both sides of 1112a.

Further, a step extending along the shape of the claw magnetic poles 1111a, 1112a is formed on the inner peripheral side of both sides in the circumferential direction of the claw magnetic poles 1111a, 1112a, and the thick part of the permanent magnet 1130a is engaged with this step. It is like that. For this reason, the permanent magnet 1130a is positioned and held between the claw magnetic poles 1111a and 1112a.

Note that the permanent magnet 1130a of the third embodiment also uses the above-mentioned magnet having a binder of a precursor having excellent wettability with a rare earth magnet material, preferably a precursor of SiO _2. Therefore, a complicated shape having a curved surface can be accurately and easily formed. For this reason, it has at least the above-described effects, and in addition, has the following effects.

  In the third embodiment, since a magnet having a curved shape is used, an arbitrary shape can be taken as shown in FIG. 17 in the region surrounded by the claw magnetic pole and the field winding. Therefore, it is possible to install a permanent magnet having a volume larger than the shape of a rectangular parallelepiped existing between adjacent claw magnetic poles. Since the magnet volume increases, the amount of magnetic flux generated by the permanent magnet can be increased. Torque can be increased when this rotating electrical machine is used as a motor. In addition, when used as a generator, the amount of power generation can be increased.

Further, since the rotor 1110 rotates at a high speed, a centrifugal force acts. In the embodiment of FIG. 17, the centrifugal force acting on the permanent magnet 1130a is divided into a step between the claw magnetic poles 1111a and 1112a and a thin portion of the permanent magnet 1130a. Since it can receive by the inner peripheral part which opposes, holding | maintenance of the permanent magnet 1130a can also be made favorable. If the thin portion has a thickness that can withstand centrifugal force, the step between the claw magnetic poles 1111a and 1112a can be omitted, and the permanent magnet 1130a can be held only by the inner circumference of the claw magnetic poles 1111a and 1112a. Is possible.

[Fourth embodiment]
Next, a fourth embodiment of the rotating electrical machine will be described. FIG. 18 is a perspective view showing the rotor of the fourth embodiment.

The permanent magnet 1130a shown in FIG. 18 is formed by integrating the permanent magnets 1130a arranged in the circumferential direction in the third embodiment into a ring shape. In this way, a permanent magnet having a more complicated shape is also subjected to compression molding of a rare earth magnet powder in a mold, and then a rare earth magnet material and a precursor having excellent wettability, preferably a precursor of SiO _2. It can be easily molded by impregnation. The permanent magnet may be magnetized after molding, or may be magnetized by being incorporated into an integral mold. Further, a magnetized one may be incorporated.

  As described above, in the fourth embodiment, since the respective permanent magnets 1130a are integrated, in addition to the operational effects of the above-described embodiment, there are operational effects that the number of parts can be reduced and the assembly is facilitated.

Further, FIG. 19 shows an enlarged view of the claw magnetic pole 1112a of this embodiment. In order to cope with the problem caused by the centrifugal force acting on the permanent magnet 1130a, in this embodiment, the permanent magnet is integrated over the entire circumference. Since it was molded, the permanent magnet 1130a can suppress the force in the direction of projecting to the outer diameter side even if centrifugal force is applied. For this reason, it is possible to suppress excessive force from acting on the claw magnetic poles 1112a and 1112b, and it is possible to minimize deformation of the claw magnetic poles 1112a and 1112b due to centrifugal force. Further, in the embodiment shown in FIG. 19, when individual magnets are arranged apart from one another between the magnetic poles, it is not necessary to process the step of suppressing the magnets to prevent each magnet from jumping out due to centrifugal force, and the structure is simple. There is an advantage that it can be made cheaper accordingly.

[Fifth embodiment]
Next, a fifth embodiment of the rotating electrical machine will be described. FIG. 20 shows a fifth embodiment relating to the AC motor 1100 described with reference to FIGS.

As in FIG. 10, the rotor of the fifth embodiment has a tandem structure in which a rotor having claw magnetic poles 1111a and 1112a and two claw magnetic poles 1111b and 1112b are connected in the axial direction. In this way, permanent magnets are arranged between the claw magnetic poles 1111a and 1112a and between the claw magnetic poles 1111b and 1112b of the respective rotors arranged in the axial direction, and one rotor (FIG. 20). A sintered magnet 1300a is fixed between the claw magnetic poles 1111a and 1112a on the left side of FIG. 20, and the magnet used in the above embodiment is provided between the claw magnetic poles 1111b and 1112b of the other rotor (right side in FIG. 20). Similarly, a permanent magnet 1130b obtained by binding a powder made of a rare earth magnet material with a binder having a good wettability, preferably with a binder of SiO ₂ , is fixed.

  According to the fifth embodiment, since one rotor uses a sintered permanent magnet, the amount of magnetic flux per permanent magnet volume is large and a high output can be obtained. That is, in the fifth embodiment, it is possible to obtain a rotating electrical machine system having a higher output density than the above embodiment.

[Sixth embodiment]
Further, as a modified example of the above embodiment, in a vehicle system, particularly an automobile, when a generator having a rotor with permanent magnets between claw magnetic poles of a Landell type iron core or a plurality of rotating electric machines such as electric motors, At least one rotating electric machine uses the above-mentioned magnet having a binder of a rare earth magnet material and a precursor having excellent wettability as a permanent magnet, preferably a precursor of SiO ₂ , and the other It is conceivable to use a sintered magnet as a permanent magnet in a rotating electrical machine.

In the sixth embodiment, a sintered magnet is used as a permanent magnet, and therefore a binder of a precursor having excellent wettability with a rare earth magnet material, preferably a precursor of SiO ₂ is used as a binder. Thus, it is possible to obtain a rotating electrical machine system having a higher output density than the embodiment in which the rotating electrical machine using the above-described magnet is used alone.

  While the embodiments of the present invention have been described above, the following effects can be obtained by using these embodiments. Many of these effects have been described in the above embodiment, but will be described again.

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

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

In addition, according to each embodiment of the present invention, each magnet material is coated with a binder, and as a result, each portion of the magnet is insulated. Features include high electrical resistivity and low eddy current loss. As a result, the motor can be made highly efficient and capable of handling high-speed rotation. Specifically, SiO ₂ is thinly impregnated as a binder with good wettability into the magnet powder, and since SiO ₂ is an insulating material, each magnet powder is in a state of having a thin insulating coating. As a result, the electrical resistivity of the magnet is increased and eddy current is less likely to flow.

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

  Further, according to each embodiment of the present invention, since the permanent magnet can be manufactured at a relatively low temperature, the magnet material can be bound in a state in which the shape and dimensions of the magnet material by press molding are maintained with high accuracy. it can. As a result, it becomes easy to produce magnets with high accuracy. For this reason, the magnet after being hardened with a binder is much easier to form than a sintered magnet, and the final shape of the magnet is often obtained with a slight amount of cutting work. The magnet can be completed. In addition, since the magnets with complicated shapes have almost no heat shrinkage, it is possible to achieve the dimensional accuracy of the magnet with the accuracy of the mold, and to obtain a high-precision rotating electric machine without uneven rotation using a magnet with high dimensional accuracy. Can do. Thereby, a rotor can be comprised using the magnet which had the curved shape which was not made with the conventional sintered magnet, and the complicated and continuous three-dimensional shape. For this reason, it becomes possible to manufacture the rotary electric machine with more excellent characteristics.

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

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

  Since the permanent magnet of the above embodiment has good workability, it has a feature that it can be easily cut after the final shape. For this reason, after mounting a permanent magnet between claw magnetic poles of a rotor, in order to balance a permanent magnet, it can cut. By cutting the permanent magnet having a strong magnetic flux energy in this way, it is possible to suppress variations in the energy of each permanent magnet and to reduce the cogging torque resulting therefrom. This cutting process makes use of the feature that the magnet material can be post-processed. With conventional sintered magnets, if they were processed after being mounted on a rotor, problems of corrosion due to cracking and oxidation occurred, which could not be actually achieved. Thereby, torque pulsation can be reduced and a rotating machine with good controllability can be obtained.

Moreover, although the permanent magnet of the said Example bind | concludes magnetic powder with a binder, when using it for a rotary electric machine, you may change the magnitude | size of the particle | grains of magnetic powder according to a place. . Here, the larger the magnetic powder particle size, the better the magnetic properties. For example, collecting large magnetic powder at the corners and surface of permanent magnets with severe demagnetization improves reliability. can do. In this way, the technique of changing the size of the magnetic powder particles depending on the location does not necessarily require the binder to be SiO ₂ and can be applied to a conventional bonded magnet. In addition, it is not necessary to perform compression molding at once to change the size of magnetic powder particles. For example, magnets having different particle sizes are separately molded, and finally these magnets are integrated. It doesn't matter.

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

Moreover, if the permanent magnet of the said Example is used, it will become possible to manufacture the permanent magnet provided with both the anisotropy and isotropic property in one permanent magnet. When used in a rotating electrical machine, it is better to make the side close to the claw magnetic poles anisotropic and to make it isotropic, and with this configuration, magnetization can be performed satisfactorily. Note that the technique of having anisotropy and isotropic properties depending on the location does not necessarily require the binder to be SiO ₂ , and can be applied to a conventional bonded magnet.

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

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

In the above embodiment, SiO ₂ is used as a binder for the magnetic powder, but it is also conceivable to use SiO ₂ as an insulator. Specifically, SiO ₂ may be interposed between the steel plates of the laminated steel plate used for the stator core. In this case, it is not necessary to apply an adhesive to each of the laminated steel sheets to integrate them, and the low viscosity SiO ₂ precursor can be immersed in the SiO ₂ precursor in a state where the laminated steel sheets are laminated. The steel sheets can be brought into contact with each other and bonded together.

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

  Next, the characteristics that can be grasped from each of the above-described embodiments will be described below together with the effects. These features include those other than those described above and those that overlap, but will be described again in addition to the descriptions of the features described above.

  (1) A rotating electrical machine in which a rotor rotates relative to a stator, and the stator is wound around a stator core having a plurality of slots in a circumferential direction and the slots of the stator core. The rotor has a plurality of permanent magnets in the circumferential direction, and at least one of the permanent magnets has a cutting mark formed thereon. A rotating electric machine that is characterized. Alternatively, in the rotating electrical machine in which the rotor rotates relative to the stator, the stator includes a stator core having a plurality of slots in the circumferential direction, and a stator wound around the slots of the stator core. A rotor winding, and the rotor in the manufacturing method of a rotating electrical machine having a plurality of permanent magnets in the circumferential direction, the permanent magnet is used to adjust the imbalance of the plurality of permanent magnets. The manufacturing method of the rotary electric machine characterized by cutting a magnet. By cutting the permanent magnet having a strong magnetic flux energy in this way, it is possible to suppress variations in the energy of each permanent magnet and to reduce the cogging torque resulting therefrom.

  (2) The rotating electrical machine according to (1), wherein after the permanent magnet is cut, anticorrosive measures are applied to the cut portion. By comprising in this way, preserving of a cutting location can be prevented.

  (3) A rotating electrical machine in which a rotor rotates relative to a stator, wherein the stator is wound around a stator core having a plurality of slots in a circumferential direction and the slots of the stator core. The rotor has a permanent magnet, and the permanent magnet is formed by binding magnetic powder, and the size of the particles of the magnetic powder. A rotating electric machine characterized in that the height varies depending on the position. By configuring in this way, it is possible to use a magnetic powder having large particles at a location where excellent magnetic properties are required depending on the application.

  (4) The rotating electrical machine according to (3), wherein the permanent magnet is formed in a shape having a corner, and the particles of the magnetic powder in the corner are larger than other portions. Rotating electric machine. By configuring in this way, it is possible to improve the magnetic characteristics of the corners where demagnetization is severe.

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

  (6) A rotating electrical machine in which a rotor relatively rotates with respect to a stator, and the stator is wound around a stator core having a plurality of slots in a circumferential direction and the slots of the stator core. The rotor has a permanent magnet, and the permanent magnet is formed by binding different kinds of magnetic powder depending on the location. A rotating electric machine that is characterized. As described above, since the characteristics of the permanent magnet can be varied depending on the location, it is possible to make the permanent magnet suitable for the desired characteristics.

  (7) The rotating electrical machine according to (6), wherein the permanent magnet is bound in a state in which different types of magnetic powders are arranged in layers. Since the magnetic powder has a flat shape, different types of magnetic powder can be clearly separated by forming different types of magnetic powder in layers, and manufacturing is facilitated.

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

(9) The method for manufacturing a rotating electrical machine according to (6), wherein the permanent magnet is impregnated with a precursor of SiO ₂ after compression-molding each magnetic powder separately or simultaneously in the same mold. A method of manufacturing a rotating electrical machine, characterized in that the rotating electrical machine is molded. By comprising in this way, it becomes possible to manufacture easily the permanent magnet from which a characteristic changes with places.

  (10) A rotating electrical machine in which a rotor rotates relative to a stator, wherein the stator is wound around a stator core having a plurality of slots in a circumferential direction and the slots of the stator core. The rotor has a permanent magnet, and the permanent magnet has both an anisotropic location and an isotropic location. A rotating electric machine that is characterized. In this way, the permanent magnet can be made isotropic or anisotropic depending on the location, so that it is possible to make the permanent magnet suitable for the desired characteristics.

  (11) A rotating electric machine according to (10), wherein both sides in the circumferential direction are anisotropic and isotropic between them. By comprising in this way, magnetization can be performed favorably.

  (12) A rotating electrical machine in which a rotor rotates relative to a stator, wherein the stator is wound around a stator core having a plurality of slots in a circumferential direction and the slots of the stator core. The rotor has a permanent magnet, and the permanent magnet is formed by binding flat magnetic powders, and each of the magnetic powders. The rotating electric machine is characterized in that the direction of the flat surface is substantially directed to the stator core side. If comprised in this way, the outstanding magnetic characteristic can be acquired rather than the surface of the side which is not flat turned to a stator side.

  (13) A rotating electrical machine in which a rotor rotates relative to a stator, wherein the stator is wound around a stator core having a plurality of slots in a circumferential direction and the slots of the stator core. The rotor has a permanent magnet, and the permanent magnet is formed by binding flat magnetic powder, and the magnetic powder is: A rotating electrical machine characterized in that the direction of a flat surface substantially coincides with the direction of magnetization. By comprising in this way, magnetization can be performed favorably.

  (14) A rotating electrical machine in which a rotor rotates relative to a stator, the stator being wound in a slot of a stator core having a plurality of slots in the circumferential direction and the stator core. The rotor has a permanent magnet, and the permanent magnet is formed by binding flat magnetic powder, and the magnetic powder is: A rotating electrical machine characterized in that a direction of a flat surface substantially coincides with a direction in which stress acts. By comprising in this way, durability of the permanent magnet with respect to stress can be improved.

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

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

(17) A rotating electrical machine in which a rotor rotates relative to a stator, wherein the stator includes a stator core having a plurality of slots in a circumferential direction formed by stacking steel plates, and the stator. A rotating electrical machine comprising a stator winding wound in the slot of an iron core, wherein SiO ₂ is interposed between the steel plates in the stator core. By immersing the laminated steel sheets in the SiO ₂ precursor, the low viscosity SiO ₂ precursor can enter between the steel sheets and bind the steel sheets together.

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

The system block diagram which shows the structure of the electric four-wheel drive vehicle by 1st Example of this invention. The output characteristic figure of a permanent magnet type synchronous motor which does not have a field winding type synchronous motor and a field winding. Energy flow diagram of an electric four-wheel drive vehicle using an AC motor without a large-capacity battery. The system block diagram which shows the structure of the control apparatus of the electric four-wheel drive vehicle by 1st Example of this invention. The block diagram which shows the structure of the control apparatus of the electric four-wheel drive vehicle by 1st Example of this invention. The flowchart which shows operation | movement of the generator control part of the control apparatus of the electric four-wheel drive vehicle by 1st Example of this invention. The flowchart which shows operation | movement of the electric motor control part of the control apparatus of the electric four-wheel drive vehicle by 1st Example of this invention. The characteristic view which shows the electric power generation characteristic of a generator. The timing chart which shows the control action by the control apparatus of the electric four-wheel drive vehicle by 1st Example of this invention. Sectional drawing which shows the whole structure of the permanent magnet motor which has the 1st field winding used for the electric four-wheel drive vehicle of this invention. The figure explaining the manufacturing process of a magnet assembly. Another embodiment in the manufacturing process of a magnet assembly. Another embodiment in the manufacturing process of a magnet assembly. Sectional drawing of the manufactured magnet. The figure which shows the experimental result of a magnet. Sectional drawing of the generator as 2nd Example of this invention. The disassembled perspective view of the claw magnetic pole type | mold rotor which shows 3rd Example of this invention. The disassembled perspective view of the claw pole type | mold rotor which shows 4th Example of this invention. The enlarged view of the claw magnetic pole front-end | tip part of 4th Example. The perspective view of the rotor in 5th Example of this invention.

Explanation of symbols

1014 Generator 1016 Inverter 1040 12V battery generator 1100 Synchronous motor 1103 Stator 1104, 1104a, 1104b Stator core 1106 Stator winding 1110 Rotor 1111a, 1111b, 1112a, 1112b Claw magnetic pole 1113a, 1113b Field winding 1130a , 1130b Permanent magnet 1210 Power generation control unit 1220 Motor control unit 2500 AC generator for vehicle

Claims (20)

A rotating electrical machine in which the rotor rotates relative to the stator,
The stator is composed of a stator core having a plurality of slots in the circumferential direction, and a stator winding wound in the slot of the stator core.
The rotor has a field winding excited from the outside and at least a pair of claw magnetic poles each generating a magnetic field having a different polarity by excitation of the field winding,
A permanent magnet disposed between the nail poles,
The permanent magnet is formed by binding magnetic powder with a SiO-based material. In the rotating electrical machine according to claim 1,
The rotating electric machine according to claim 1, wherein the polarity of the permanent magnet is magnetized to the same polarity as the polarity of the surface on which the polarity of the claw magnetic pole is determined by excitation of the field winding. In the rotating electrical machine according to claim 1,
The rotating electric machine according to claim 1, wherein the permanent magnet has a thin portion extending toward an inner peripheral side of each of the claw magnetic poles. In the rotating electrical machine according to claim 1,
A plurality of pairs of claw magnetic poles are provided, and a permanent magnet disposed between the claw magnetic poles is integrated. In the rotating electrical machine according to claim 4,
A rotating electric machine characterized in that a permanent magnet disposed between each of the claw magnetic poles has a ring shape. In the rotating electrical machine according to claim 5,
The rotating electric machine according to claim 1, wherein the permanent magnet has a shape along an inner periphery of the claw magnetic pole. In the rotating electrical machine according to claim 1,
The rotating electric machine characterized in that the permanent magnet has a curved surface. The rotating electrical machine according to claim 7,
The rotating electric machine characterized in that a curved surface portion of the permanent magnet is curved in a rotation direction of the rotor. In the rotating electrical machine according to claim 1,
The rotor has a plurality of claw pole pairs in the axial direction,
A rotating electrical machine, wherein a sintered magnet is disposed between at least one of the plurality of claw magnetic pole pairs. A method of manufacturing a rotating electrical machine in which a rotor rotates relative to a stator,
The stator is manufactured by a step of forming a stator core having a plurality of slots in the circumferential direction, and a step of winding a stator winding in the slot of the stator core.
The rotor includes a step of forming a divided rotor core having at least a pair of claw magnetic poles, a step of winding a field winding in the rotor core, and a permanent magnet between the claw magnetic poles. And a process of integrating a rotor core divided into a plurality of parts,
Further, the permanent magnet is formed by press-molding magnetic powder, impregnating the press-molded body with a solution that is a binder precursor, and impregnating the binder precursor with the binder. A method of manufacturing a rotating electrical machine, wherein the press-molded body is manufactured by a heat treatment. In the manufacturing method of the rotary electric machine according to claim 10,
The method for manufacturing a rotating electrical machine, wherein the binder solution is a precursor of SiO ₂ . In the manufacturing method of the rotary electric machine according to claim 11,
The binder solution contains at least one of alkoxysiloxane, alkoxysilane, a hydrolysis product thereof, and a dehydration condensate thereof, and water, and is formed from an alcohol and a hydrolysis catalyst if necessary. A method of manufacturing a rotating electrical machine. In the manufacturing method of the rotary electric machine according to claim 10,
The method for manufacturing a rotating electrical machine, wherein the binder contains an alkoxy group. In the manufacturing method of the rotary electric machine according to claim 10,
An automobile equipped with a rotating electrical machine, wherein the magnetic powder is provided with an inorganic insulating film having a thickness of 10 μm to 10 nm. In the manufacturing method of the rotary electric machine according to claim 10,
A plurality of pairs of the claw magnetic poles are provided, and the processed molded body is formed so that permanent magnets arranged between the claw magnetic poles are integrated, and the binding is formed from a part of the processed molded body. A method of manufacturing a rotating electrical machine, wherein the impregnating solution is impregnated so as to spread throughout. In the manufacturing method of the rotary electric machine according to claim 10,
The method of manufacturing a rotating electrical machine, wherein the pressure-molded body is impregnated with the binder solution under atmospheric pressure. An automobile equipped with a rotating electrical machine in which the rotor rotates relative to the stator,
The rotor includes a permanent magnet between the claw magnetic poles of the Landell type iron core,
The permanent magnet is configured by binding magnetic powder with a binder, and the binder is configured to be capable of entering between compressed magnetic powders in a liquid state. An automobile equipped with a rotating electric machine. In the motor vehicle provided with the rotating electrical machine according to claim 17,
The permanent magnet rotating electric machine has a plurality, and at least one of the permanent magnet rotating electric machines uses the permanent magnet formed by binding magnetic powder with a binder, and the other permanent magnet rotating electric machines Is an automobile equipped with a rotating electrical machine, wherein a sintered magnet is used. In the motor vehicle provided with the rotating electrical machine according to claim 17,
An automobile equipped with a rotating electrical machine, wherein the rotating electrical machine is used as the rotating electrical machine in an electric four-wheel drive vehicle in which some wheels are driven by an engine and other wheels are driven by a rotating electrical machine. In the motor vehicle provided with the rotating electrical machine according to claim 17,
The rotating electric machine is used in an AC generator driven by an engine. An automobile equipped with the rotating electric machine.

Images