JP6907742B2 - Magnet material manufacturing method, motor manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a magnet material and a method for manufacturing a motor.

Conventionally, motors such as brushed motors and brushless motors have magnets for driving. For example, the rotor included in the motor is formed by aligning the anisotropic magnet and then magnetizing it (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 63-36508

By the way, the stator included in the motor includes a tubular magnet attached to the inner peripheral surface of the yoke or the case housing. It may be difficult to apply a sufficient alignment magnetic field to such a tubular anisotropic magnet. Therefore, it is required to easily generate a magnet used for a motor by applying a sufficient alignment magnetic field.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for manufacturing a magnet and a method for manufacturing a motor, which can easily form a magnet used for a motor.

The method for manufacturing a magnet material that solves the above problems is a method for manufacturing a magnet included in a motor, in which a mixed material containing anisotropic magnet powder and a flexible binder is filled in a mold, and the mold is used. have a step of generating oriented sheet magnet having an orientation to flexible the anisotropic magnet powder by applying a magnetic field to said mixed material in the mold with molding the mixed material into a sheet, The anisotropic magnet powder is oriented to generate the alignment sheet magnet in which N poles and S poles are alternately arranged along one direction, and the alignment sheet magnet is parallel to the arrangement direction of the magnetic poles. Diagonally cut along two imaginary lines to form a parallel quadrilateral oriented sheet magnet, and the length of the two diagonally cut sides of the aligned sheet magnet is the peripheral surface of the rotor or stator member of the motor. Orientation sheet magnets for one round of the above are generated .

According to this configuration, since the anisotropic magnet powder is oriented at the stage of molding the sheet-shaped magnet, a sufficient alignment magnetic field can be applied as compared with the case where the annular magnet is oriented, and the magnet is highly oriented. Is obtained. Then, the magnet of the motor can be easily formed by attaching the flexible alignment sheet magnet to the peripheral surface of a member of the rotor or the stator, for example, a cylindrical yoke. In addition, by controlling the orientation magnetic field at the stage of molding a mixed material containing anisotropic magnet powder and a flexible binder into a sheet, tubular magnets with various orientations such as radial orientation and polar anisotropic orientation. Is easily obtained.

According to this configuration, in a tubular magnet obtained by attaching an alignment sheet magnet to the peripheral surface of a rotor or stator member, a magnet having a skew in which each magnetic pole is inclined in the circumferential direction with respect to the axial direction. Is easily obtained.
In the above method for manufacturing a magnet material, at least in the step of controlling the applied magnetic field to generate the alignment sheet magnet a plurality of times to generate a plurality of alignment sheet magnets and generating the alignment sheet magnet. It is preferable to have a step of generating a plurality of alignment sheet magnets in which the orientation of one alignment sheet magnet is different from the orientation of the other alignment sheet magnets, and laminating the plurality of alignment sheet magnets.

According to this configuration, by laminating a plurality of alignment sheet magnets having different orientation directions from the others and forming them into a cylindrical shape, magnets having various orientations that cannot be obtained by one alignment sheet magnet can be obtained. Be done.

A method for manufacturing a motor that solves the above problems is a method for manufacturing a motor having a tubular magnet, in which a mixed material containing anisotropic magnet powder and a flexible binder is filled in a mold, and the mold is used. A step of molding the mixed material into a sheet and applying a magnetic field to the mixed material in the mold to orient the anisotropic magnet powder to generate a flexible oriented sheet magnet, and the orientation. possess a step of attaching the sheet magnets in the circumferential surface of the rotor or stator members, a step of said tubular magnet magnetized processing the oriented sheet magnet, and then orienting the anisotropic magnet powder A parallel quadrilateral shape is formed by cutting the alignment sheet magnet, in which N poles and S poles are alternately arranged along one direction, diagonally along two imaginary lines parallel to the arrangement direction of the magnetic poles. Alignment sheet magnets of No. 1 and the lengths of the two diagonally cut sides of the alignment sheet magnets are one circumference of the peripheral surface of the rotor or the member of the stator, and the alignment sheet magnets are generated. The alignment sheet magnet is attached to the peripheral surface of the member with its two sides along the circumferential direction of the member, and the alignment sheet magnet for one circumference is magnetized to obtain the tubular magnet .

According to this configuration, since the anisotropic magnet powder is oriented at the stage of molding the sheet-shaped magnet, a sufficient alignment magnetic field can be applied as compared with the case where the annular magnet is oriented, and the magnet is highly oriented. Is obtained. Then, the magnet of the motor can be easily formed by attaching the flexible alignment sheet magnet to the peripheral surface of a member of the rotor or the stator, for example, a cylindrical yoke. In addition, by controlling the orientation magnetic field at the stage of molding a mixed material containing anisotropic magnet powder and a flexible binder into a sheet, tubular magnets with various orientations such as radial orientation and polar anisotropic orientation. Is easily obtained.
According to this configuration, a tubular magnet obtained by attaching an alignment sheet magnet to the peripheral surface of a member of a rotor or a stator can be easily obtained.

In the above method for manufacturing a motor, at least one step is performed in a step of controlling an applied magnetic field to generate the alignment sheet magnet a plurality of times to generate a plurality of alignment sheet magnets and generating the alignment sheet magnet. The orientation of the plurality of alignment sheet magnets is different from the orientation of the other alignment sheet magnets to generate a plurality of alignment sheet magnets, and the plurality of alignment sheet magnets are laminated. It is preferable to attach the rotor or stator to the peripheral surface of the member and magnetize the plurality of alignment sheet magnets to obtain the tubular magnet.

According to this configuration, by laminating a plurality of alignment sheet magnets having different orientation directions from the others and forming them into a cylindrical shape, magnets having various orientations that cannot be obtained by one alignment sheet magnet are included. A motor is obtained.

According to the method for manufacturing a magnet material and the method for manufacturing a motor of the present invention, a magnet used for a motor can be easily formed.

The schematic explanatory view of the motor of 1st Embodiment. (A) to (d) are schematic explanatory views of the alignment sheet magnet and the manufacturing process of the stator using the alignment sheet magnet. (A) to (c) are explanatory views showing the orientation state of the alignment sheet magnet. (A) is an explanatory view of an alignment sheet magnet to be cut, (b) is an explanatory view of the alignment sheet magnet after cutting, and (c) is an explanatory view of a tubular magnet. (A) is an explanatory view of an alignment sheet magnet to be cut, (b) is an explanatory view of the alignment sheet magnet after cutting, and (c) is an explanatory view of a tubular magnet. (A) is a schematic explanatory view of the motor of the second embodiment, and (b) is an explanatory view showing the tubular magnet of the second embodiment in an unfolded manner. (A) is an explanatory view of laminated alignment sheet magnets, and (b) is an explanatory view of laminated alignment sheet magnets. Explanatory drawing which shows polar anisotropic orientation with respect to a tubular magnet. (A) and (b) are explanatory views showing polar anisotropic orientation with respect to a tubular magnet.

Hereinafter, each form will be described.
In the attached drawings, the components may be enlarged for easy understanding. The dimensional ratios of the components may differ from the actual ones or those in another drawing. Further, in the cross-sectional view, hatching of some components may be omitted for easy understanding.

(First Embodiment)
Hereinafter, the first embodiment will be described.
As shown in FIG. 1, the motor 1 of the present embodiment has a stator 10 and a rotor 20. The stator 10 includes a tubular yoke 11 and a tubular magnet 12 attached to the inner peripheral surface of the yoke 11. In FIG. 1, the tubular magnet 12 is radially oriented and magnetized so that north poles and south poles are alternately arranged in the circumferential direction on the inner peripheral surface. The tubular magnet 12 is composed of an alignment sheet magnet as a flexible magnet material. The alignment sheet magnet has flexibility and is formed in a substantially flat plate shape. Further, the alignment sheet magnet has a desired orientation in a substantially flat plate shape. This alignment sheet magnet is arranged along the inner peripheral surface 11a of the yoke 11. After that, it is magnetized to obtain a tubular magnet 12.

The manufacturing process of the alignment sheet magnet and the manufacturing process of the tubular magnet 12 using the alignment sheet magnet will be described.
As shown in FIG. 2A, a mixed material 30 containing the magnet powder 31 and the binder 32 is produced. The magnet powder 31 is, for example, anisotropic magnet powder. As the anisotropic magnet powder, magnet powder such as neodymium (Nd-Fe-B) magnet, ferrite magnet, samarium iron nitrogen (Sm-Fe-N) magnet, samarium cobalt (Sm-Co) magnet, etc. .. The binder 32 is a flexible binder, and rubber or the like can be used, for example. Although a liquid binder is shown as the binder 32 in FIG. 2A, a solid binder can also be used. The additive 33 may be added to the mixed material 30. The additive 33 is, for example, a coupling material, a lubricant, or the like.

As shown in FIG. 2B, the mixing material 30 is stored in the tank 41 of the magnetic field forming apparatus 40. Then, the mixed material 30 is filled from the tank 41 into the mold 42. In the tank 41, the magnet powder 31 contained in the mixing material 30 is uniformly dispersed. In FIG. 2B, the arrows shown by the magnet powders 31 indicate the orientation direction of the magnet powders 31.

The mold 42 is for molding the mixed material 30 into a sheet shape. The mold 42 is a non-magnetic material that allows a magnetic field to pass through. Alignment devices 43 and 46 are provided above and below the mold 42. The alignment devices 43 and 46 apply a magnetic field to the mixing material 30 in the mold 42. In the present embodiment, the alignment device 43 has a core 44 and coils 45a and 45b wound around the core 44. The alignment device 43 is arranged with the magnetic poles 44a and 44b of the core 44 facing the mold 42. Similarly, the alignment device 46 has a core 47 and coils 48a and 48b wound around the core 47. The alignment device 46 is arranged with the magnetic poles 47a and 47b of the core 47 facing the mold 42.

The alignment devices 43 and 46 generate a magnetic field according to the direction of the applied current of the coils 45a, 45b, 48a, 48b, the magnitude of the applied current, and the like. This magnetic field orients the magnet powder 31 contained in the mixing material 30 in the mold 42. The positions of the magnetic poles 44a, 44b, 47a, 47b of the cores 44, 47 around which the coils 45a, 45b, 48a, 48b are wound, the direction of the applied current of the coils 45a, 45b, 48a, 48b, and the magnitude of the applied current are appropriately adjusted. By setting, the orientation of the magnet powder 31 contained in the mixed material 30 can be controlled. In FIG. 2B, the alignment device 43 is controlled, and the magnet powder 31 of the mixing material 30 is oriented in a very anisotropic direction (an orientation in which magnetic poles are generated on one surface and no magnetic poles are generated on the other surface). It is shown. The magnetic flux may be controlled by using a ferromagnetic material at the entrance of the mold 42.

Further, the magnetic field forming apparatus 40 includes a processing machine 49. The processing machine 49 applies energy required for solidification of the mixing material 30 (for example, cross-linking of the binder 32) to the mixing material 30. As the energy, high frequency, electron beam, heat, etc. can be used. The magnetic field forming apparatus 40 obtains the alignment sheet magnet 50 shown in FIG. 2 (c).

The alignment sheet magnet 50 shown in FIG. 2C has a rectangular plate shape, and for example, the north pole and the south pole are alternately oriented along the long side on the upper surface. In the arrangement direction of the magnetic poles, the size (magnetic pole width) of the N pole and the S pole is set by the positions (intervals) of the magnetic poles 44a, 44b, 47a, 47b of the alignment devices 43, 46. That is, by setting the number (number of poles) and spacing (pole pitch) of the magnetic poles 44a, 44b, 47a, 47b of the alignment devices 43 and 46, the alignment sheet magnet 50 having an arbitrary magnetic pole width can be obtained. Further, by setting the direction and magnitude of the applied currents of the coils 45a, 45b, 48a, 48b of the alignment device 43 shown in FIG. 2B, an alignment sheet magnet 50 having an arbitrary orientation can be obtained.

The alignment devices 43 and 46 shown in FIG. 2B outline the device that applies an alignment magnetic field to the mixing material 30 in the mold 42, that is, the alignment sheet magnet 50 molded by the mold 42. Yes, the shape, number of magnetic poles, etc. are not limited to this. Further, at least one of the alignment devices 43 and 46 may be embedded in the mold 42. In addition, permanent magnets can also be used as the alignment devices 43 and 46. As the permanent magnet, for example, a sintered magnet (for example, a rare earth sintered magnet) can be used.

As shown in FIG. 2D, the alignment sheet magnet 50 is attached to the inner peripheral surface of the yoke 11. Then, the alignment sheet magnet 50 is magnetized by a magnetizing device (not shown). As a result, the desired tubular magnet 12 can be obtained.

3 (a) to 3 (c) show alignment examples in the alignment sheet magnet. The orientation of the alignment sheet magnet 51 shown in FIG. 3A is a radial orientation in which magnetic poles appear on both main surfaces and are oriented in the thickness direction.

The orientation of the alignment sheet magnet 52 shown in FIG. 3 (b) is a polar anisotropic orientation in which magnetic poles appear only on one main surface (upper surface in FIG. 3 (b)).
The orientation of the alignment sheet magnet 53 shown in FIG. 3C is a Halbach orientation including magnetic poles appearing on both main surfaces and an orientation along the main surface between the magnetic poles.

In the case of the radial alignment sheet magnet 51 shown in FIG. 3 (a), the alignment sheet magnet 51 is yoked so that the upper surface or the lower surface of the alignment sheet magnet 51 faces the inner peripheral surface of the yoke 11 shown in FIG. 2 (d). It is attached to the inner peripheral surface of 11. As a result, a stator 10 (see FIG. 1) having a tubular magnet 12 and a yoke 11 made of an alignment sheet magnet 51 can be obtained.

In the case of the polar anisotropic oriented oriented sheet magnet 52 shown in FIG. 3 (b), the oriented sheet magnet 52 is yoked with the lower surface of the oriented sheet magnet 52 facing the inner peripheral surface of the yoke 11 shown in FIG. 2 (d). It is attached to the inner peripheral surface of 11. In the case of the orientation sheet magnet 52 having an extremely anisotropic orientation, the member to be attached may be a non-magnetic material. For example, a stator can be obtained by attaching an alignment sheet magnet 52 to the inner peripheral surface of a non-magnetic case housing.

In the case of the Halbach-oriented oriented sheet magnet 53 shown in FIG. 3 (c), the oriented sheet magnet 53 is yoked so that the upper surface or the lower surface of the oriented sheet magnet 53 faces the inner peripheral surface of the yoke 11 shown in FIG. 2 (d). It is attached to the inner peripheral surface of 11. When the Halbach-aligned alignment sheet magnet 53 is used, the magnetic flux density distribution in the circumferential direction of the stator can be a substantially sinusoidal wave.

It is preferable to cut the alignment sheet magnet 50 (51 to 53) according to the size of the member to be attached.
As shown in FIG. 4 (a), the alignment sheet magnet 51 is cut along the arrangement direction (direction indicated by the two-dot chain line) of the magnetic poles (N pole and S pole), and is shown in FIG. 4 (b). A rectangular alignment sheet magnet 51a is obtained. The longitudinal direction of the alignment sheet magnet 51a (horizontal direction in FIG. 4B) is the circumferential direction, and the direction orthogonal to the circumferential direction (vertical direction in FIG. 4B) is the width direction. The length in the circumferential direction is defined as one circumference of the inner peripheral surface of the yoke 11 shown in FIG. 2 (d). As shown in FIG. 4C, the alignment sheet magnet 51a is made into a rounded cylindrical magnet. As a result, the alignment sheet magnet 51a is attached to the inner peripheral surface of the yoke 11 shown in FIG. 2 (d) in just proportion.

As shown in FIG. 5A, the alignment sheet magnet 50 is cut and processed in a direction inclined with respect to the arrangement direction of the magnetic poles (N pole, S pole) (indicated by a two-dot chain line), and is cut in FIG. 5 (b). ) Is obtained as a parallel quadrilateral oriented sheet magnet 51b. The length of the side of the alignment sheet magnet 51b (the length of the side in the left-right direction in FIG. 5B) is defined as one circumference of the inner peripheral surface of the yoke 11 shown in FIG. 2D. As shown in FIG. 5C, the alignment sheet magnet 51b is made into a rounded cylindrical magnet.

As a result, the alignment sheet magnet 51b is attached to the inner peripheral surface of the yoke 11 shown in FIG. 2 (d) in just proportion. Further, the cylindrical magnet (alignment sheet magnet 51b) is skewed with an inclination in the circumferential direction with respect to the axial direction (width direction in FIG. 5B). Then, in the motor having the tubular magnet 12, the change of the magnetic flux at the time of pole switching becomes smooth due to the skew of the magnetic poles (N pole, S pole). Therefore, it is possible to suppress an increase in cogging torque in the motor.

Although the alignment sheet magnet 51b having a parallel quadrilateral shape was generated in FIG. 5B, the shape of the alignment sheet magnet obtained by cutting may be rectangular. Even in this case, the alignment sheet magnet is rolled so that the direction forming a right angle with respect to the cut side is the axial direction on the main surface of the alignment sheet magnet to generate a tubular magnet. Even with the tubular magnet thus generated, it is possible to obtain a skew-oriented tubular magnet having an inclination in the circumferential direction with respect to the axial direction. Then, in the motor having this tubular magnet, the change of the magnetic flux at the time of pole switching becomes smooth due to the skew orientation. Therefore, it is possible to suppress an increase in cogging torque in the motor.

When cutting the alignment sheet magnet 50, it is preferable to demagnetize the alignment sheet magnet 50. By the demagnetization treatment, it is possible to prevent tools, chips, and the like for cutting the alignment sheet magnet 51 from adhering to the alignment sheet magnet 51. Then, the oriented sheet magnets 51a and 51b (see FIGS. 4 (b) and 5 (b)) after cutting are attached to the inner peripheral surface of the yoke 11 shown in FIG. 2 (d). Then, the alignment sheet magnets 51a and 51b are magnetized by a magnetizing device (not shown) to form a tubular magnet 12. Then, after magnetization, the cylindrical magnet 12 can be easily obtained as compared with the case where the cylindrical magnet material is magnetized after the orientation treatment.

Note that FIGS. 4 (a) to 4 (b) and 5 (a) to 5 (c) show examples of cutting the radial orientation sheet magnet 51. The polar anisotropic oriented sheet magnet 52 shown in FIG. 3 (b) and the Halbach oriented sheet magnet 53 shown in FIG. 3 (c) can also be cut in the same manner.

(Action)
First, the orientation method of the comparative example will be described. Here, a case of obtaining a polar anisotropy tubular magnet will be described.

FIG. 8 shows a case where the magnetic poles appear only on the outer peripheral surface of the annular magnet 61 and are oriented in a polar anisotropic orientation (peripheral polar anisotropic orientation). The alignment device 71 has a plurality of cores 71a arranged on the outer side in the radial direction of the annular magnet 61, and a coil 71b wound around each core 71a. An alignment magnetic field 71c is generated by the currents supplied to the plurality of cores 71a, and the annular magnet 61 is oriented.

9 (a) and 9 (b) show a case of orientation in a polar anisotropic orientation (inner circumferential polar anisotropic orientation) in which magnetic poles appear only on the inner peripheral surface of the annular magnet 62. The alignment device 72 shown in FIG. 9A has a core 72a arranged inside the annular magnet 62, and a plurality of coils 72b wound around the core 72a. A current is supplied to each coil 72b, and the annular magnet 62 is oriented by the generated alignment magnetic field 72c. The alignment device 73 shown in FIG. 9B aligns the annular magnet 62 with a permanent magnet.

As shown in FIGS. 9 (a) and 9 (b), in the case of anisotropic orientation of the inner peripheral poles, it is necessary to arrange the orientation devices 72 and 73 inside the annular magnet 62. However, when the annular magnet 62 having a small inner diameter is oriented, the alignment devices 72 and 73 become small and a sufficient alignment magnetic field cannot be applied to the annular magnet 62.

In the case of the present embodiment, as described above, the alignment sheet magnet 50 (51 to 53) is oriented at the molding step of the flexible alignment sheet magnet 50 (51 to 53). Therefore, a sufficient alignment magnetic field can be applied to the alignment sheet magnets 50 (51 to 53). Then, by using the oriented sheet magnets 50 (51 to 53) oriented in this way, for example, magnets having an anisotropic orientation of the inner peripheral pole can be easily formed. Further, when the alignment sheet magnet 51 is cut to obtain the alignment sheet magnets 51a and 51b, a sufficient alignment magnetic field can be applied by aligning the alignment sheet magnets 51a and 51b at the stage of being flat after the cutting process.

Further, the orientation method of the above-mentioned comparative example requires different orientation devices 71 to 73 for the outer peripheral polar anisotropic orientation and the inner peripheral polar anisotropic orientation. On the other hand, in the present embodiment, the alignment sheet magnet 50 is oriented at the molding stage of the flexible alignment sheet magnet 50. For example, by using an oriented sheet magnet 52 that is extremely anisotropically oriented and forming the oriented sheet magnet 52 so that the magnetic poles are on the inner peripheral side, a tubular magnet having an anisotropically oriented inner peripheral electrode can be obtained. Further, by forming the alignment sheet magnet 52 so that the magnetic poles are on the outer peripheral side, a tubular magnet having an anisotropic orientation on the outer periphery can be obtained. That is, the flexible alignment sheet magnet 52 makes it possible to obtain a tubular magnet having an anisotropic orientation of the inner peripheral pole and a tubular magnet having an anisotropic orientation of the outer peripheral pole.

A magnet having an anisotropy of the outer peripheral pole can be used for the rotor. For example, the alignment sheet magnet 50 (51 to 53) is attached to the outer peripheral surface of a member (for example, a rotor core) included in the rotor. For example, when the oriented sheet magnet 52 having a very anisotropic orientation shown in FIG. 3B is used, a non-magnetic material can be used for a member (for example, a rotor core) included in the rotor. In FIG. 3B, the lower surface of the alignment sheet magnet 52 is directed toward the outer peripheral surface of the rotor member, and the alignment sheet magnet 52 is attached to the member.

As described above, according to the present embodiment, the following effects are obtained.
(1-1) The mixing material 30 containing the magnet powder 31 and the binder 32 is filled in the mold 42 of the magnetic field forming apparatus 40, and the alignment magnetic field is applied to the mixing material 30 by the alignment devices 43 and 46 to apply the magnet powder 31. Orient. Then, the alignment sheet magnet 50 having flexibility is generated by the mixing material 30. In this way, in the molding step of the flexible alignment sheet magnet 50 (51 to 53), the alignment sheet magnet 50 (51 to 53) is oriented. Therefore, a sufficient alignment magnetic field can be applied to the alignment sheet magnets 50 (51 to 53).

(1-2) By using the oriented oriented sheet magnet 50 (51 to 53), for example, a magnet having an anisotropic direction of the inner peripheral pole can be easily formed. Further, when the alignment sheet magnet 51 is cut to obtain the alignment sheet magnets 51a and 51b, a sufficient alignment magnetic field can be applied by aligning the alignment sheet magnets 51a and 51b at the stage of being flat after the cutting process.

(1-3) At the molding stage of the flexible alignment sheet magnet 50, the alignment sheet magnet 50 is oriented. For example, by using an oriented sheet magnet 52 that is extremely anisotropically oriented and forming the oriented sheet magnet 52 so that the magnetic poles are on the inner peripheral side, a tubular magnet having an anisotropically oriented inner peripheral electrode can be obtained. Further, by forming the alignment sheet magnet 52 so that the magnetic poles are on the outer peripheral side, a tubular magnet having an anisotropic orientation on the outer periphery can be obtained. That is, the flexible alignment sheet magnet 52 provides a tubular magnet having an anisotropic orientation of the inner peripheral pole and a tubular magnet having an anisotropic orientation of the outer peripheral pole.

(1-4) The alignment sheet magnet 51 is cut along the arrangement direction of the magnetic poles (N pole, S pole) to obtain a rectangular alignment sheet magnet 51a. The longitudinal direction of the alignment sheet magnet 51a is the circumferential direction, and the length in the circumferential direction is one circumference of the inner peripheral surface of the yoke 11. As a result, the alignment sheet magnet 51a can be attached to the inner peripheral surface of the yoke 11 without excess or deficiency.

(1-5) The alignment sheet magnet 51 is cut in a direction inclined with respect to the arrangement direction of the magnetic poles (N pole, S pole) to obtain an alignment sheet magnet 51b having a parallel quadrilateral shape. The length of the side of the alignment sheet magnet 51b is defined as one circumference of the inner peripheral surface of the yoke 11. As a result, the tubular magnet (alignment sheet magnet 51b) attached to the inner peripheral surface of the yoke 11 is skewed with an inclination in the circumferential direction with respect to the axial direction. Then, in the motor having the tubular magnet 12, the change of the magnetic flux at the time of pole switching becomes smooth due to the skew of the magnetic poles (N pole, S pole). Therefore, it is possible to suppress an increase in cogging torque in the motor.

(Second Embodiment)
Hereinafter, the second embodiment will be described.
In this embodiment, the same components as those in the above embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 6A, the motor 101 of this embodiment has a stator 110 and a rotor 20. The stator 110 includes a tubular yoke 11 and a tubular magnet 120 attached to the inner peripheral surface of the yoke 11. In FIG. 6A, the tubular magnet 120 is composed of a plurality of (three in this embodiment) alignment sheet magnets 121, 122, 123 stacked in the radial direction. FIG. 6B shows a state in which the tubular magnet 120 is deployed, and shows the orientation state of each alignment sheet magnet 121, 122, 123.

In FIG. 6A, the first alignment sheet magnet 121, the second alignment sheet magnet 122, and the third alignment sheet magnet 123 are used in this order from the inside to the outside.
As shown in FIG. 7A, the first alignment sheet magnet 121 is radially oriented. That is, the first alignment sheet magnet 121 has magnetic poles appearing on the inner peripheral surface and the outer peripheral surface, and is oriented so that the north and south poles are alternately arranged in the circumferential direction on the inner peripheral surface. The second alignment sheet magnet 122 is radially oriented like the first alignment sheet magnet 121. The third orientation sheet magnet 123 is very anisotropically oriented. That is, the third oriented sheet magnet 123 has magnetic poles appearing on the inner peripheral surface and is oriented so that the north and south poles are alternately arranged in the circumferential direction on the inner peripheral surface. In the first to third oriented sheet magnets 121 to 123, the arrangement pitches of the magnetic poles are equal to each other. Therefore, as shown in FIG. 7B, the tubular magnet 120 obtained by stacking the first to third oriented sheet magnets 121 to 123 has magnetic poles appearing on the inner peripheral surface and has a long magnetic path (high permeance). It is a tubular magnet with a very anisotropic orientation. By stacking a plurality of oriented sheet magnets in this way, it is possible to increase the magnetic path (high permeance).

The alignment sheet magnet obtained by laminating the first to third alignment sheet magnets 121 to 123 may be formed into a cylindrical shape so that the first alignment sheet magnet 121 is on the outer peripheral side. In this case, magnetic poles appear on the outer peripheral surface, and a tubular magnet having a long magnetic path (high permeance) with extremely anisotropic orientation can be obtained.

Further, each of the alignment sheet magnets 121 to 123 may be cut in the same manner as in FIGS. 4 (a) and 4 (b) or FIGS. 5 (a) and 5 (b) described above. For example, the alignment sheet magnet (see FIG. 7B) obtained by laminating the first to third alignment sheet magnets 121 to 123 may be cut. Further, each of the alignment sheet magnets 121 to 123 may be individually cut and processed, and the processed alignment sheet magnets may be laminated.

By cutting in the same manner as in FIGS. 5 (a) and 5 (b), a tubular magnet skewed by a long magnetic path (high permeance) can be obtained. A motor using this magnet has a high magnetic flux and can suppress an increase in cogging torque.

When cutting the alignment sheet magnets 121 to 123, it is preferable to demagnetize the alignment sheet magnets 121 to 123. By the demagnetization treatment, it is possible to prevent tools, chips, and the like for cutting the alignment sheet magnets 121 to 123 from adhering to the alignment sheet magnets 121 to 123. Then, the cut alignment sheet magnets 121 to 123 are attached to the inner peripheral surface of the yoke 11 shown in FIG. 6A. Then, the alignment sheet magnets 121 to 123 are magnetized using a magnetizing device (not shown). As a result, the cylindrical magnet 120 can be easily obtained as compared with the case where the cylindrical magnet material is magnetized after the orientation treatment.

As described above, according to the present embodiment, the following effects are obtained.
(2-1) A plurality of orientation sheet magnets 121 to 123 oriented in a desired orientation are generated. The alignment sheet magnets 121 to 123 are obtained by controlling the applied magnetic field in the magnetic field forming apparatus 40. These alignment sheet magnets 121 to 123 are laminated, and the laminated alignment sheet magnets 121 to 123 are attached to the inner peripheral surface of the yoke 11 to form a tubular magnet 120. As a result, tubular magnets 120 having various orientations, which cannot be obtained with a single alignment sheet magnet, can be obtained.

(2-2) Radially oriented alignment sheet magnets 121 and 122 and polar anisotropic oriented sheet magnets 123 were laminated to form a tubular magnet 120. The tubular magnet 120 is a tubular magnet in which magnetic poles appear on the inner peripheral surface and the long magnetic path (high permeance) is extremely anisotropically oriented. By stacking a plurality of oriented sheet magnets in this way, it is possible to increase the magnetic path (high permeance).

(2-3) The alignment sheet magnets 121 to 123 are cut diagonally with respect to the arrangement direction of the magnetic poles, and the processed alignment sheet magnets are attached to the inner peripheral surface of the yoke 11. As a result, a tubular magnet skewed by a long magnetic path (high permeance) can be obtained. A motor using this magnet has a high magnetic flux and can suppress an increase in cogging torque.

(Modification example)
In addition, each of the above-mentioned embodiments may be carried out in the following embodiments.
-For each of the above embodiments, a rotor having a magnet may be configured. For example, the alignment sheet magnet 50 (51 to 53) is attached to the outer peripheral surface of a member (for example, a rotor core) included in the rotor. For example, when the oriented sheet magnet 52 having a very anisotropic orientation shown in FIG. 3B is used, a non-magnetic material can be used for a member (for example, a rotor core) included in the rotor. In FIG. 3B, the lower surface of the alignment sheet magnet 52 is directed toward the outer peripheral surface of the rotor member, and the alignment sheet magnet 52 is attached to the member. Similarly, as in the second embodiment, the rotor may have a plurality of laminated alignment sheet magnets.

In the second embodiment, the radial orientation sheet magnets 121 and 122 and the polar anisotropic orientation sheet magnet 123 are laminated to form one alignment sheet magnet. On the other hand, the Halbach-aligned alignment sheet magnet 53 shown in FIG. 3C may be laminated in combination with another alignment sheet magnet. By stacking the orientation sheet magnets having different orientations in this way, a magnet having a complicated orientation that cannot be obtained by a single alignment sheet magnet can be obtained.

-In the second embodiment, three alignment sheet magnets 121 to 123 are laminated, but two or four or more alignment sheet magnets may be laminated.

10,110 ... stator, 11 ... yoke, 12,120 ... tubular magnet, 20 ... rotor, 31 ... magnet powder, 32 ... binder, 40 ... magnetic field forming device, 42 ... mold, 43,46 ... alignment device, 50 , 51-53, 121-123 ... Alignment sheet magnet.

Claims (4)

A method for manufacturing magnet materials contained in motors.
A mixed material containing anisotropic magnet powder and a flexible binder is filled in a mold, the mixed material is molded into a sheet by the mold, and a magnetic field is applied to the mixed material in the mold. have a step of generating oriented sheet magnet having flexibility by orienting the anisotropic magnet powder,
The anisotropic magnet powder is oriented to generate the oriented sheet magnet in which N poles and S poles are alternately arranged along one direction.
The alignment sheet magnet is cut diagonally along two imaginary lines parallel to the arrangement direction of the magnetic poles to obtain a parallelogram-shaped alignment sheet magnet, and the two sides of the alignment sheet magnet cut diagonally. A method for manufacturing a magnet material, which produces an oriented sheet magnet having a length equal to one circumference of a peripheral surface of a rotor or stator member of the motor. The step of controlling the applied magnetic field to generate the alignment sheet magnet is executed a plurality of times to generate a plurality of alignment sheet magnets.
In the step of producing the alignment sheet magnet, a plurality of alignment sheet magnets in which the orientation of at least one alignment sheet magnet is different from the orientation of the other alignment sheet magnets are generated.
Having a step of laminating the plurality of alignment sheet magnets,
The method for manufacturing a magnet material according to claim 1. A method for manufacturing a motor having a tubular magnet.
A mixed material containing anisotropic magnet powder and a flexible binder is filled in a mold, the mixed material is molded into a sheet by the mold, and a magnetic field is applied to the mixed material in the mold. A step of orienting the anisotropic magnet powder to produce a flexible oriented sheet magnet, and
The step of attaching the alignment sheet magnet to the peripheral surface of the rotor or stator member, and
A step of magnetizing the alignment sheet magnet to obtain the tubular magnet, and
Have a,
The alignment sheet magnet in which the north pole and the south pole are alternately arranged along one direction by orienting the anisotropic magnet powder is obliquely along two imaginary lines parallel to the arrangement direction of the magnetic poles. Orientation sheet magnet that is cut into a parallel quadrilateral shape to make an alignment sheet magnet, and the length of the two diagonally cut sides of the alignment sheet magnet is one circumference of the peripheral surface of the rotor or the member of the stator. Is attached to the peripheral surface of the member with the two sides along the circumferential direction of the member, and the alignment sheet magnet for one circumference is magnetized. A method for manufacturing a motor using the tubular magnet. The step of controlling the applied magnetic field to generate the alignment sheet magnet is executed a plurality of times to generate a plurality of alignment sheet magnets.
In the step of producing the alignment sheet magnet, a plurality of alignment sheet magnets in which the orientation of at least one alignment sheet magnet is different from the orientation of the other alignment sheet magnets are generated.
It has a step of laminating the plurality of alignment sheet magnets, and has a step of laminating the plurality of alignment sheet magnets.
Attaching the plurality of aligned sheet magnets laminated to the peripheral surface of a member of a rotor or a stator, and magnetizing the plurality of oriented sheet magnets to obtain the tubular magnet.
The method for manufacturing a motor according to claim 3.

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