JP2008035636A - Magnetizing yoke - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetizing yoke capable of stably forming a wanted intermediate magnetizing region. <P>SOLUTION: A magnetizing yoke 44 comprises an insert hole 46 in which a rotor (magnetic material) 10 is fitted, a plurality of magnetizing conductive wire insert holes 48 arranged outside the insert hole 46, and a plurality of cuts 50 that are provided between the plurality of magnetizing conductive wire insert holes 48 and the insert hole 46 so that the magnetizing conductive wire insert holes 48 are communicated with the insert hole 46. It is arranged close to the outer peripheral side of the rotor 10. The magnetizing conductive insert holes 48 are arranged with a specified interval in circumferential direction, at the positions away by a specified distance d1 toward the outer peripheral side from the insert hole 46. The cut 50 becomes wider as advances from the magnetizing conductive wire insert hole 48 to the insert hole 46, having a tapered part 56 that is connected to an internal peripheral surface IF of the insert hole 46. At such place as has circumferential direction dimension corresponding to the tapered part 56 of the rotor 10, intermediate magnetizing regions (12b+14b) are stably obtained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a magnetizing yoke used for magnetizing a magnetic material when manufacturing a permanent magnet which is a component of an electric motor.

  When manufacturing ring-shaped permanent magnets, which are components of permanent magnet electric motors such as AC servo motors, brushless DC motors, and synchronous motors, a magnetized yoke fitted on the outside of the magnetic material is used. Magnetization is performed, and different magnetic poles are provided alternately in the circumferential direction. The electric motor may be used, for example, for driving a magnetic disk or an optical disk in an acoustic device or OA device, or for configuring an electric actuator of a mechanical device. Torque ripple (pulsation component of output torque) that is a pulsation component of output torque and cogging torque (torque change when the output shaft is rotated with the drive current being zero) are as small as possible. It is desired.

On the other hand, in Patent Document 1, for example, the skew magnetization that rotates in one direction as the boundary line between the S-pole magnetized region and the N-pole magnetized region moves in one axial direction is the ring shape. Discloses a technique for setting the skew angle α (the twist angle range of the magnetization boundary line around the axis) within a predetermined numerical range. Further, in Patent Document 2, for example, a magnet known as a neoquenched magnet among neodymium magnets, that is, a neodymium magnet processed so as to hold a fine crystal is a fine crystal in the radial direction. Providing an intermediate magnetization region in which the magnetization strength (magnetic flux density on the surface) is gently changed at a predetermined magnetization inclination angle θ in the circumferential direction at the boundary between the magnetization region and the N-pole magnetization region; Including the saturation (complete) magnetization region sandwiched between the intermediate magnetization regions, the magnetization strength is a trapezoidal wave in the circumferential direction, and the ratio of the trapezoidal wave magnetization is determined by the cogging torque. A technique is disclosed in which the generation period is substantially half of the region.
JP 2004-129487 A JP 2004-242489 A

  By the way, the skew angle α for minimizing the torque ripple does not become a value for minimizing the cogging torque, while the magnetizing inclination angle θT for minimizing the torque ripple minimizes the cogging torque. Not the same as the value to do. For this reason, it is necessary to provide the skew angle α and the magnetization inclination angle θT so as to be an optimum combination. However, it is relatively difficult to obtain a desired value of the magnetization inclination angle θT among the skew angle α and the magnetization inclination angle θT.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a magnetized yoke capable of stably forming a desired intermediate magnetized region.

  As a result of repeating various studies on the background of the above circumstances, the present inventor has formed magnetic conducting wire insertion holes at predetermined intervals in the circumferential direction at positions spaced a predetermined distance from the insertion holes for inserting magnetic materials to the outer peripheral side. When the tapered portion is arranged and connected to the inner peripheral surface of the insertion hole, the width dimension becomes wider toward the insertion hole from the magnetization conducting wire insertion hole, and the notch corresponds to the taper portion. It has been found that an intermediate magnetized region having a circumferential dimension can be stably obtained. The present invention has been made based on such findings.

  That is, the invention according to claim 1 is an insertion hole for fitting a magnetic material, a plurality of magnetization conducting wire insertion holes arranged outside the fitting hole, the plurality of magnetization conducting wire insertion holes, A plurality of notches that are respectively provided between the insertion holes and communicate with the insertion holes of the magnetized conductive wires, and are adjacent to the outer peripheral side of the magnetic material in order to magnetize the magnetic material. (A) the magnetization conducting wire insertion holes are arranged at a predetermined interval in the circumferential direction at a position spaced a predetermined distance from the insertion hole to the outer peripheral side, (b) 2. The magnetized yoke according to claim 1, wherein the notch has a tapered portion that becomes wider in width toward the insertion hole from the magnetization conducting wire insertion hole and connects to the inner peripheral surface of the insertion hole.

  In the invention according to claim 2, in the invention according to claim 1, the maximum interval among the intervals between the inner peripheral surface of the insertion hole and the tapered portion in the radial direction is set to at least 1 mm. It is characterized by.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the circumferential dimension of the tapered portion is greater than the intermediate magnetization region formed in the magnetic material in the circumferential direction of the magnetic material. It is characterized by having a dimension that is larger by a predetermined value.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the plurality of magnetized conducting wire insertion holes and notches are divided at equal angles around the center of the insertion hole. It is characterized by being formed in a line symmetrical shape with respect to the line.

  Further, the invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the magnetic material is obtained by bulkizing a flat metal powder obtained by ultra-cooling a molten metal by hot pressing, It is a neo-quenched radial anisotropic magnetic material formed by intermediate back extrusion.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, characterized in that the magnetic material is an Nd—Fe—B-based metal.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the magnetic material has an energy product of 30 MGOe or more.

  According to the magnetizing yoke of the invention according to claim 1, a fitting hole for fitting a magnetic material, a plurality of magnetizing conducting wire insertion holes arranged outside the fitting hole, and the plurality of magnetizing conducting wires. A plurality of notches provided between the insertion hole and the insertion hole, each of which communicates the magnetization conducting wire insertion hole with the insertion hole, and an outer periphery of the magnetic material for magnetizing the magnetic material. In the magnetized yoke arranged close to the side, (a) the magnetized conducting wire insertion holes are arranged at predetermined intervals in the circumferential direction at positions spaced a predetermined distance from the insertion holes to the outer peripheral side, and (b ) Since the notch has a shape that has a tapered portion connected to the inner peripheral surface of the insertion hole, the width dimension increases from the magnetization conducting wire insertion hole toward the insertion hole. In the magnetic material, in the location of the circumferential dimension corresponding to the tapered portion, The Chaku磁領 region can be obtained stably.

  Further, according to the magnetized yoke of the invention according to claim 2, since the maximum interval among the intervals between the inner peripheral surface of the insertion hole and the tapered portion in the radial direction is set to at least 1 mm, An intermediate magnetization region in which the magnetic flux density changes smoothly can be obtained stably.

  According to the magnetizing yoke of the invention of claim 3, the circumferential dimension of the tapered portion is larger by a predetermined value than the intermediate magnetized region formed in the magnetic material in the circumferential direction of the magnetic material. Since it has dimensions, an intermediate magnetization region in which the magnetic flux density changes smoothly can be accurately obtained in the circumferential direction of the magnetic material.

  According to the magnetizing yoke of the invention according to claim 4, the plurality of magnetized conducting wire insertion holes and notches are line-symmetrical with respect to a dividing line obtained by dividing the center of the insertion hole at an equal angle. Therefore, the N region and the S region in the intermediate magnetization region can be obtained uniformly.

  Further, according to the magnetized yoke of the invention according to claim 5, the magnetic material is formed by hot backward extrusion after bulkizing the flat metal powder obtained by ultra-quenching the molten metal by hot pressing. Further, since it is a neo-quenched radial anisotropic magnetic material, fine crystals can be obtained, and an intermediate magnetization region can be suitably obtained in the radial magnetization.

  According to the magnetized yoke of the invention according to claim 6, since the magnetic material is a Nd—Fe—B metal, a high energy product can be obtained. Preferably, the magnetic material has an energy product of 30 MGOe or more.

  Here, preferably, the magnetic material has a ring shape or a cylindrical shape and is used as a rotor (rotary armature) on the inner peripheral side or outer peripheral side of the electric motor. If present, it may be used as a stator.

  Preferably, the magnetized yoke is made of a metal having a high saturation magnetic flux density and a low hysteresis, such as soft iron and silicon steel.

  Hereinafter, a rotor used in a brushless motor according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing a rotor 10 used in, for example, a brushless motor. The rotor 10 is a magnetic material formed in a cylindrical shape from an Nd—Fe—B-based metal, and includes three S-pole magnetized regions 12 magnetized to the S pole on the outer peripheral surface, and N on the outer peripheral surface. This is a six-pole permanent magnet provided with three N-pole magnetized regions 14 magnetized to poles in a state of being twisted in one circumferential direction toward a single axial direction at a predetermined skew angle α. This skew angle α is centered on an axis C where the magnetization boundary line 16 between the S pole magnetized region 12 and the N pole magnetized region 14 indicates a twist range from one end of the rotor 10 to the other end. Is an angle.

  The S pole magnetized region 12 of the rotor 10 is composed of an S pole saturated magnetized region 12a that is saturated and magnetized to the S pole and an S pole intermediate magnetized region 12b that is unsaturated magnetized to a lower level. The N-pole magnetized region 14 is also composed of an N-pole saturated magnetized region 14a that is saturated and magnetized to the N-pole, and an N-pole intermediate magnetized region 14b that is unsaturated and magnetized lower than that. FIG. 2 is a diagram showing the magnetization intensity of the S pole saturation magnetization region 12a and the S pole intermediate magnetization region 12b. The N-pole magnetized region 14 is also shown by a waveform obtained by inverting the same waveform.

  The rotor 10 is made of a magnetic material that is an Nd—Fe—B metal, and is made of a neodymium magnet having a high energy product of 30 MGOe or more. In particular, this neodymium magnet is obtained by hot-extrusion after hot metal is used to bulkize flat metal powder that has been ultra-cooled and powdered by dropping molten metal onto a rotating body. It is comprised from the radial anisotropic magnetic material shape | molded by the cylindrical shape. For this reason, the neodymium magnet of the present embodiment is also called a neoquenched magnet and includes fine crystal grains (in the present embodiment, the average grain diameter is 1 μm or less). And

  FIG. 2 is a two-dimensional coordinate of an axis indicating the position in the circumferential direction and an axis indicating the magnetization strength (magnetic flux density: Tesla T). In the S-pole saturated magnetization region 12a, a certain magnetization strength is obtained. As shown, in the pair of S pole intermediate magnetization regions 12b adjacent to both sides, the magnetization strength is continuously linearly toward zero from the saturation magnetization as the strength of the magnetization is separated from the S pole saturation magnetization region 12a. Has been reduced. In FIG. 2, the point K on the horizontal axis corresponds to the position of the magnetization boundary line 16.

  FIG. 3 shows a main part of the magnetizing device 20 for magnetizing the rotor 10. In FIG. 3, the magnetizing device 20 includes a magnetizing power source 22 and a magnetizing yoke device 26 connected to the magnetizing power source 22 by a pair of exciting conducting wires 24. For example, as shown in FIG. 4, the magnetized power source 22 is configured to boost the output voltage of the AC power source 30, the inverter 32 that controls the output current of the AC power source 30, and the inverter 32 to several hundred to several thousand volts. A step-up transformer 34, a rectifier 36 that converts the AC output of the step-up transformer 34 into a direct current, a capacitor 38 that stores the DC charge output from the rectifier 36, and 1 to 10 kA based on the charge stored in the capacitor 38. And a switching element 40 for outputting a magnetizing current Ic of a certain level to the magnetizing yoke device 26 in the form of pulses.

  As shown in FIG. 3, the magnetizing yoke device 26 includes a base 42, a plurality of disk-shaped magnetizing yokes 44 fixed in a stacked state on the base 42, and concentrically fixing them. And a yoke fixing device (not shown).

  FIG. 6 is a plan view showing the magnetizing yoke 44, and FIG. 7 is an enlarged view showing a central portion which is a main part of the magnetizing yoke 44. As shown in FIG. 6 and 7, the magnetizing yoke 44 has a fitting hole 46 having the same inner diameter as the outer diameter of the rotor 10 so that the cylindrical rotor 10 can be fitted thereinto, and the exciting conducting wire 24 to be inserted therethrough. A plurality of magnetization conducting wire insertion holes 48 arranged outside the fitting hole 46 and a plurality of magnetization conducting wire insertion holes 48 and the fitting hole 46 are provided, and the magnetization conducting wire insertion holes 48 are inserted into the fitting holes. 46, a plurality of notches 50 communicated with 46, and a mounting hole 52 formed in the outer peripheral portion and formed long in the circumferential direction. By passing the positioning jig through the mounting hole 52, the through bolts (not shown) of the yoke fixing device are fixed to the base 42 through the mounting hole 52 in a state where the positions around the axis C are sequentially positioned. In this state, when the rotor 10 is inserted into the insertion hole 46, the axis C of the rotor 10 is aligned with the axis of the insertion hole 46, so that the inner peripheral surface IF of the insertion hole 46 is in the cross section of the rotor 10. The magnetizing yoke 44 is arranged in a laminated state adjacent to the outer peripheral side of the rotor 10 in order to magnetize the rotor 10.

As shown in detail in FIG. 7, the magnetized conducting wire insertion hole 48 is long in the radial direction and is circumferential in a position separated from the insertion hole 46 by a predetermined distance d <b> 1 (5 mm in this embodiment). Are arranged at a predetermined angular interval θ1 (60 degrees in this embodiment). The notch 50 includes a slit portion 54 having a predetermined length d2 (1 mm in this embodiment) corresponding to the opening of the magnetized conducting wire insertion hole 48, and the magnetized conducting wire insertion hole 48 following the slit portion 54. The width dimension, that is, the dimension in the circumferential direction increases toward the insertion hole 46 from the insertion hole 46, and has a tapered portion 56 connected to the inner peripheral surface IF of the insertion hole 46 with a predetermined radius of curvature R of about 1 mm. In the radial direction, the maximum distance d _max out of the distance between the inner peripheral surface IF of the insertion hole 46 and the tapered portion 56 is set to a distance of about 1 to 3 mm, that is, at least 1 mm.

  The plurality of magnetized conducting wire insertion holes 48, the slit portions 54, and the notches 50 are line-symmetrical with respect to the dividing line DL obtained by dividing the center of the insertion hole 46 at an equal angle (60 degrees in this embodiment). Is formed. The circumferential dimension WT of the tapered portion 56 is a predetermined value W1 (in this embodiment, 0 of WT) than the circumferential dimension WC of the intermediate magnetization region (12b + 14b) formed in the rotor 10 in the circumferential direction of the rotor 10. It is set to have a dimension that is larger by a factor of.

  In the magnetizing device 20 configured as described above, when magnetizing the magnetic material constituting the rotor 10 inserted into the magnetizing yoke device 26, a controller (not shown) causes the switching element 40 to pass for a predetermined time. By closing, the DC magnetizing current Ic illustrated in FIG. 5 is supplied to the magnetizing yoke device 26. In the inner peripheral part of each magnetizing yoke 44, the magnetic flux generated by this magnetizing current Ic is formed between the magnetic poles 44j which are parts between the tapered parts 56, that is, parts located on the innermost periphery. A part of the rotor 10 guided along the magnetic path and located in the magnetic path is locally magnetized. That is, the portion of the outer peripheral surface of the rotor 10 facing the magnetic pole 44j is saturated and magnetized. For example, when a portion of the outer peripheral surface of the rotor 10 facing the magnetic pole 44j is magnetized in the S pole magnetized region 12, the back surface of the S pole is magnetized to the N pole. At the same time, a part of the rotor 10 facing the tapered portion 56 of the magnetizing yoke 44 is unsaturated magnetized, and the magnetization intensity is linearly continuous between the S pole magnetized region 12 and the N pole magnetized region 14. The intermediate magnetization region (12b + 14b) that changes with time is formed.

Here, FIG. 8 shows a magnetization gradient in an AC servomotor having a rotor 10 made of a cylindrical 6-pole permanent magnet of 39.0 mmφ × 33.0 mmφ and a 9-slit (9-pole) stator. This shows the relationship between the rotation angle of the rotor 10 composed of a neo-quenching magnet and the cogging torque (pulsation of the rotation torque of the rotor at zero drive current) TC with the angle θT as a parameter, and the magnetization inclination angle θT is 15 degrees In some cases, the cogging torque TC is the minimum value. FIG. 9 shows the relationship between the skew angle α and the fundamental wave content (%) in the same AC servomotor with the magnetization tilt angle θT as a parameter. This fundamental wave content rate is the ratio that the primary waveform (fundamental wave that is a sine wave) component is included in all frequency components when frequency analysis is performed on the induced voltage waveform induced in the coil when the rotor is driven to rotate at 1000 rpm. It can be evaluated that the higher the fundamental wave content, the lower the torque ripple. According to FIG. 9, the fundamental wave content rate is the highest in the region where the skew angle α is centered at 24.3 degrees for each magnetization inclination angle θT, and is fundamental when the magnetization inclination angle θT is 8 degrees. The wave content is the highest. As described above, in order to minimize the cogging torque TC and maximize the fundamental wave content, it is necessary to set an optimum value of the combination of the magnetization inclination angle θT and the skew angle α. The skew angle α is arbitrarily set by setting a circumferential shift of the magnetized yokes 44 stacked in the magnetizing device 20. Regarding the magnetization inclination angle θT, the circumferential dimension WT of the taper portion 56 of the magnetizing yoke 44 constituting the magnetizing device 20 and the maximum from the inner peripheral surface IF of the insertion hole 46 in the radial direction of the taper portion 56. It is suitably set by setting the interval d _max .

  FIG. 10 shows the magnetization curve (BH curve) of the rotor 10 made of a neoquenched magnet, and FIG. 11 shows the magnetization curve of the rotor 10 made of a sintered neodymium magnet without fine crystals. In the rotor 10 composed of a neo-quenching magnet, as shown in FIG. 10, the intermediate magnetization (incomplete magnetization) of each value as indicated by each black dot is set by separating the maximum magnetization point of each curve. Is easy. However, in the rotor 10 composed of a sintered neodymium magnet having no fine crystal, as shown in FIG. 11, the setting of intermediate magnetization (incomplete magnetization) of each value as indicated by each black dot is as follows. Since the maximum magnetization point is close, it was extremely difficult.

  As described above, according to the magnetizing yoke 44 of the present embodiment, the insertion hole 46 for inserting the rotor (magnetic material) 10 and the plurality of magnetization conducting wire insertions arranged outside the insertion hole 46 are inserted. A hole 48, and a plurality of notches 50 provided between the plurality of magnetization conducting wire insertion holes 48 and the insertion hole 46, respectively, and communicating the magnetization conducting wire insertion hole 48 with the insertion hole 46; In the magnetizing yoke 44 disposed close to the outer peripheral side of the rotor 10 for magnetizing the rotor 10, (a) the magnetized conducting wire insertion hole 48 is separated from the fitting hole 46 to the outer peripheral side by a predetermined distance d1. (B) The notches 50 become wider in width toward the insertion hole 46 from the magnetization conducting wire insertion hole 48 toward the insertion hole 46, and the inner peripheral surface IF of the insertion hole 46. With a tapered portion 56 connected to the Since, the location of the circumferential dimension corresponds to the tapered portion 56 in the rotor 10 can be obtained intermediate magnetization region and (12b + 14b) stable.

Further, according to the magnetized yoke 44 of the present embodiment, the maximum distance d _{max of the} distance between the inner peripheral surface IF of the insertion hole 46 and the tapered portion 56 in the radial direction is set to at least 1 mm. The intermediate magnetization region (12b + 14b) in which the magnetic flux density changes smoothly can be obtained stably.

  Further, according to the magnetized yoke 44 of the present embodiment, the circumferential dimension WT of the tapered portion 56 is a predetermined value than the intermediate magnetized region (12b + 14b) formed in the rotor 10 in the circumferential direction of the magnetic material. Since it has a dimension larger by W1, an intermediate magnetization region (12b + 14b) in which the magnetic flux density changes smoothly can be accurately obtained in the circumferential direction of the magnetic material.

  Further, according to the magnetizing yoke 44 of the present embodiment, the plurality of magnetized conducting wire insertion holes 48 and the notches 50 are line symmetrical with respect to the dividing line DL obtained by dividing the center of the insertion hole 46 at an equal angle. Thus, the N-pole magnetized region and the S-pole magnetized region in the intermediate magnetized region (12b + 14b) can be obtained uniformly.

  Further, according to the magnetized yoke 44 of the present embodiment, the rotor 10 is a neo-quenching system formed by hot backward extrusion after bulkizing flat metal powder obtained by ultra-cooling the molten metal into powder by hot pressing. Since this is a radial anisotropic magnetic material, fine crystals are obtained, and an intermediate magnetization region (12b + 14b) is suitably obtained in the radial magnetization.

  Further, according to the magnetized yoke 44 of the present embodiment, since the rotor 10 is an Nd—Fe—B metal, a high energy product, for example, an energy product of 30 MGOe or more can be obtained.

  As mentioned above, although one Example of this invention was described based on drawing, this invention is applied also in another aspect.

  For example, in the above-described embodiment, the cylindrical magnetic material is applied to the rotor 10, but may be applied to the stator of the electric motor.

  Further, the magnetizing yoke 44 of the above-described embodiment has a circular plate shape, but may be configured in a rectangular plate shape.

  In addition, the magnetized conducting wire insertion hole 48 provided in the magnetizing yoke 44 of the above-described embodiment is a long ellipse that is long in the radial direction, but may be another shape such as a circle.

  In the magnetizing yoke 44 of the above-described embodiment, the eight magnetized conducting wire insertion holes 48 and the notches 50 are formed, but the number thereof can be variously changed according to the number of magnetic poles of the rotor 10 to be magnetized. Is added.

  The above description is merely an example of the present invention, and the present invention can be modified in various ways without departing from the spirit of the present invention.

It is a perspective view which shows the rotor which is a cylindrical magnetic material magnetized using the magnetizing yoke of one Example of this invention. It is a graph which shows the change of the magnetic flux density of the circumferential direction in the surface of the rotor of FIG. It is a conceptual diagram which shows the principal part of the magnetizing apparatus for magnetizing the rotor of FIG. It is a circuit diagram explaining the structure of the magnetization power supply of the magnetization apparatus of FIG. It is a figure which shows the magnetizing current output from the magnetizing power supply of the magnetizing apparatus of FIG. It is a top view which shows the magnetizing yoke laminated | stacked in multiple numbers in the magnetizing yoke apparatus of the magnetizing apparatus of FIG. It is a figure which expands and demonstrates the center part of the magnetizing yoke of FIG. In the AC servomotor having the rotor of FIG. 1 composed of a permanent magnet of 6 poles and the stator of 9 slits (9 poles), the rotational angle and cogging of the rotor composed of a neoquenched magnet with the magnetization tilt angle θT as a parameter. It is a figure which shows the relationship with torque (pulsation of the rotational torque of the rotor in the drive current zero) TC. In the AC servo motor similar to FIG. 8, the relationship between the skew angle α and the fundamental wave content rate (%) is shown with the magnetization inclination angle θT of the rotor of FIG. 1 as a parameter. It is a figure which shows the magnetization curve (BH curve) of the rotor of FIG. 1 which consists of a magnet of a neo quench system. It is a figure which shows the magnetization curve (BH curve) of the magnetic material which consists of a sintered neodymium magnet which does not have a fine crystal.

Explanation of symbols

10: Rotor (magnetic material)
12: S pole magnetized region 12b: S pole intermediate magnetized region 14: N pole magnetized region 14b: N pole intermediate magnetized region 12b, 14b: Intermediate magnetized region 24: Excitation lead 44: Magnetized yoke 46: Insertion Hole 48: Magnetized conducting wire insertion hole 50: Notch 56: Tapered portion d1: Predetermined distance IF: Inner circumferential surface WT: Circumferential dimension DL of tapered portion DL: Dividing line

Claims (7)

An insertion hole for inserting a magnetic material, a plurality of magnetization conducting wire insertion holes arranged outside the insertion hole, and a plurality of magnetization conducting wire insertion holes and the insertion hole are provided respectively. A magnetizing yoke provided with a plurality of notches communicating the magnetized conducting wire insertion hole with the insertion hole, and disposed close to the outer peripheral side of the magnetic material in order to magnetize the magnetic material; ,
The magnetized conducting wire insertion holes are arranged at predetermined intervals in the circumferential direction at positions spaced a predetermined distance from the insertion holes to the outer peripheral side,
The notch has a tapered portion that becomes wider in width toward the insertion hole from the magnetization conducting wire insertion hole and connects to the inner peripheral surface of the insertion hole. . 2. The magnetized yoke according to claim 1, wherein a maximum interval among the intervals between the inner peripheral surface of the insertion hole and the tapered portion in the radial direction is set to at least 1 mm. The circumferential dimension of the taper-shaped portion has a dimension larger by a predetermined value than an intermediate magnetization region formed in the magnetic material in the circumferential direction of the magnetic material. 2 magnetized yokes. The plurality of magnetized conducting wire insertion holes and notches are formed in a line-symmetric shape with respect to a dividing line obtained by dividing the center of the insertion hole at an equal angle. Any magnetized yoke. The magnetic material is a neo-quenched radial anisotropic magnetic material formed by hot backward extrusion after bulking flat metal powder obtained by ultra-cooling the molten metal into powder by hot pressing. The magnetized yoke according to any one of claims 1 to 4. The magnetized yoke according to any one of claims 1 to 5, wherein the magnetic material is an Nd-Fe-B metal. The magnetized yoke according to claim 1, wherein the magnetic material has an energy product of 30 MGOe or more.

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