JP2017121118A - Method of manufacturing anisotropic magnet, method of manufacturing anisotropic soft magnetic material and method of manufacturing rotor of dynamo-electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an anisotropic magnet, divided into multiple pieces, well and efficiently.SOLUTION: A method of manufacturing multiple permanent magnets 24 having anisotropy and being built in a rotor 2 includes a preparation step of preparing a mold 31 including a lower mold 31A (first mold) having a lower mold body 32 (mold body) composed of a nonmagnetic material and having multiple recesses 33 arranged in the circumferential direction, and multiple magnetic field coils 36 provided at positions corresponding to respective recesses 33 of the lower mold body 32, and an upper mold 31B (second mold) having multiple salients 43 composed of a soft magnetic material, and forming a cavity together with the multiple recesses 33, a magnetic field molding step of forming a mold body by clamping the mold while filling each recess 33 of the lower mold 32, respectively, with a magnet material, and compressing the magnet material in each cavity while forming a magnetic field of different magnetic pole by means of the magnetic field coils 36 adjoining each other, and a magnetization step of magnetizing the mold body formed in the magnetic field molding step.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a method for manufacturing an anisotropic ferromagnetic body incorporated in a rotor of a rotating electrical machine such as a permanent magnet synchronous motor, that is, an anisotropic magnet and an anisotropic soft magnetic body, and a method for manufacturing the rotor.

  In a rotating electrical machine such as a permanent magnet synchronous motor having a permanent magnet in the rotor, when the surface magnetic flux of magnets adjacent to each other in the rotor changes suddenly, the cogging torque and the torque clip increase, and the vibration and noise of the rotating electrical machine increase. There are challenges. In this case, if an annular permanent magnet having anisotropy (polar anisotropy) is used as the permanent magnet, the surface magnetic flux waveform of the rotor can be made closer to a sine waveform, reducing cogging torque and torque clip. It is effective in doing. For example, Patent Document 1 discloses a method of manufacturing an annular magnet having such anisotropy.

JP 2006-49554 A

  In recent years, in a rotating electrical machine such as a permanent magnet synchronous motor, in order to suppress a decrease in rotational torque caused by short-circuiting of magnetic flux between adjacent magnets, a structure in which adjacent magnets are separated is used to further increase rotational torque. In addition, it is considered that a reluctance torque is positively generated by interposing a soft magnetic material between adjacent magnets. In such a rotating electrical machine, since the magnets constituting the magnetic poles of the rotor are separated from each other, each magnet is manufactured separately. It becomes difficult to maintain the mutual relationship accurately, and as a result, the surface magnetic flux between adjacent magnets is likely to change, and the cogging torque and the torque clip may be increased.

  The present invention has been made in view of the above circumstances, and includes a plurality of anisotropic magnets and a plurality of anisotropic soft magnets that are incorporated into a rotor of a rotating electrical machine such as a permanent magnet synchronous motor and used simultaneously. It is an object of the present invention to provide a technique for producing a magnetic material satisfactorily and efficiently, and to provide a technique for producing a rotating electric machine such as a permanent magnet synchronous motor that can further reduce cogging torque and torque clips.

  In order to solve the above problems, the present invention provides a method of manufacturing the plurality of magnets used in a rotor that includes a plurality of magnets arranged at intervals in the circumferential direction and each having anisotropy. A mold body made of a non-magnetic material having a plurality of recesses as many as the magnets, and a plurality of magnetic field coils provided at positions respectively corresponding to the recesses of the mold body. Preparing a mold including a first mold and a second mold having a plurality of convex portions made of a soft magnetic material forming a cavity together with the plurality of concave portions, and each concave portion of the mold body Each of which is filled with a magnet material and clamped, and in the magnetic field forming step of forming a molded body by compressing the magnet material in each cavity while forming magnetic fields having different magnetic poles by magnetic field coils adjacent to each other, and In a magnetic field A magnetizing step of applying a magnetizing treatment to the formed molded body in the mold process, is intended to include.

  According to this manufacturing method, in the molding process in the magnetic field, the magnetic field is formed so that the magnetic flux passes through the magnet materials filled in the cavities adjacent to each other, and the crystal direction of the magnet material is aligned along this magnetic field (that is, the magnetic field The magnet material is aligned so that the direction of easy magnetization is aligned). Therefore, it becomes possible to manufacture a plurality of magnets used simultaneously in the rotor while accurately ensuring the mutual relationship of the anisotropy of adjacent magnets.

  In this case, in the magnetic field molding step, it is preferable that a soft magnetic material is interposed between adjacent convex portions of the second mold.

  According to this manufacturing method, it is possible to form a good magnetic field (magnetic field) through which the magnetic flux passes through the convex portion and the soft magnetic body and reaches the magnet material in the cavity adjacent to each other. Therefore, it becomes possible to manufacture an anisotropic magnet with high accuracy.

  In the above manufacturing method, it is preferable that the magnet material in each cavity is vibrated in the molding step in the magnetic field. For example, it is preferable to apply ultrasonic vibration to the magnet material.

  According to this manufacturing method, the vibration facilitates the alignment of the crystal direction of the magnet material along the magnetic field, so that it is possible to manufacture a magnet with higher accuracy of anisotropy.

  The above manufacturing method can be applied to both radial gap type and axial gap type rotating electrical machines. For example, the rotor is a rotor of an axial gap type rotating electrical machine, and the plurality of magnets rotate. In the case of a substantially fan-like plate shape in plan view having a thickness in the axial direction, in the molding process in the magnetic field, the magnet material is compressed in the direction corresponding to the thickness of the magnet, and the magnet material is compressed. The magnetic field is formed so that the magnetic flux passes in a direction parallel to the direction.

  According to this manufacturing method, a plurality of magnets applied to a rotor of an axial gap type rotating electrical machine, specifically, a magnetic flux passing through the central portion of the magnet in the thickness direction from one side to the other side in the thickness direction. Thus, it becomes possible to satisfactorily manufacture a plurality of magnets each having anisotropy that spreads to both sides.

  In this case, as the magnetic field coil, it is preferable to use a core whose interlinkage magnetic flux surface has a substantially fan shape in plan view.

  According to this manufacturing method, a magnet having the above-described anisotropy can be manufactured with higher accuracy with respect to a substantially fan-shaped magnet in a plan view incorporated in a rotor of an axial gap type rotating electrical machine.

  On the other hand, a method for manufacturing a rotor of a rotating electrical machine according to the present invention is a method for manufacturing a rotor including a plurality of magnets arranged at intervals in the circumferential direction and each having anisotropy. A magnet manufacturing process for manufacturing the plurality of magnets using a method, and the rotor in the magnetic field forming step performed in the magnet manufacturing process by arranging the plurality of magnets manufactured in the magnet manufacturing process. And an assembly process to be incorporated.

  According to this manufacturing method, it is possible to efficiently manufacture a rotor in which the anisotropy of adjacent magnets is accurately secured.

  On the other hand, the present invention is a method of manufacturing a plurality of soft magnetic bodies having anisotropy, and a mold body made of a nonmagnetic material having a plurality of recesses arranged in the circumferential direction and the recesses of the mold body A gold including a first mold having a plurality of magnetic field coils installed at corresponding positions, and a second mold having a plurality of convex portions made of a soft magnetic material that form a cavity together with the plurality of concave portions. A preparatory step of preparing a mold, filling the concave portion of the mold body with a soft magnetic material, and clamping the mold, forming magnetic fields with different magnetic poles by magnetic field coils adjacent to each other, and forming the soft magnetic material in each cavity And a molding step in a magnetic field that forms a plurality of molded bodies that are a plurality of soft magnetic bodies having anisotropy by compression.

  The anisotropic soft magnetic body manufactured in this way is applied to a rotor structure in which anisotropic magnets and anisotropic soft magnetic bodies are alternately arranged in the circumferential direction. According to this manufacturing method, in the molding process in the magnetic field, the magnetic field is formed so that the magnetic flux passes through the soft magnetic materials filled in the cavities adjacent to each other, and the crystal direction of the soft magnetic material is aligned along this magnetic field ( That is, the soft magnetic materials are aligned along the magnetic field so that the easy magnetization directions are aligned). Therefore, it is possible to manufacture a plurality of soft magnetic bodies that are used simultaneously in the rotor while accurately ensuring the mutual relationship of anisotropy between adjacent soft magnetic bodies. Thereby, the magnetic flux in the soft magnetic material easily flows in the easy magnetization direction, and by controlling the surface magnetic flux waveform, the cogging torque and the torque clip can be suppressed and the reluctance torque can be obtained.

  In the above manufacturing method, it is preferable that the soft magnetic material in each cavity is vibrated in the molding step in the magnetic field. For example, it is preferable to apply ultrasonic vibration to the magnet material.

  According to this manufacturing method, since the crystal orientation of the soft magnetic material is promoted to be aligned along the magnetic field by vibration, it is possible to manufacture a soft magnetic body with higher accuracy of anisotropy.

  Another method of manufacturing a rotor for a rotating electrical machine of the present invention includes a plurality of magnets having anisotropy and a plurality of soft magnetic bodies having anisotropy, and the magnets and the soft magnetic bodies are circumferential. And a plurality of magnets having anisotropy manufactured using any of the above-described anisotropic magnet manufacturing methods, and any of the above-mentioned anisotropic softening methods. A plurality of anisotropy soft magnetic bodies manufactured by using a magnetic body manufacturing method is incorporated into the rotor.

  According to the rotor manufactured by this manufacturing method, the surface magnetic flux waveform can be brought close to a sine waveform for both the magnet torque and the reluctance torque, which is effective in reducing cogging torque and torque clip.

  As described above, according to the method for manufacturing an anisotropic magnet and the method for manufacturing an anisotropic soft magnetic body of the present invention, a plurality of the magnets incorporated in a rotor of a rotating electrical machine such as a permanent magnet synchronous motor and used simultaneously. The anisotropic magnet and the plurality of anisotropic soft magnetic materials can be manufactured satisfactorily and efficiently. Further, according to the rotor manufacturing method of the present invention, it is possible to manufacture a rotating electrical machine such as a permanent magnet synchronous motor that can further reduce cogging torque and torque clips.

It is a disassembled perspective view of an axial gap type motor. It is a top view (partial sectional view) of a rotor body applied to the axial gap type motor. It is sectional drawing (III-III sectional view taken on the line of FIG. 2) of the said rotor main body. It is principal part sectional drawing (IV-IV sectional view taken on the line of FIG. 2) of the said rotor main body. It is process drawing which shows the manufacturing method of an anisotropic magnet. It is a cross-sectional schematic diagram which shows the shaping | molding apparatus in a magnetic field used for the manufacturing method of the anisotropic magnet which concerns on this invention, (a) is a lower mold | type, (b) is the lower mold | die and upper mold | die which were opened. Each is shown. It is a cross-sectional schematic diagram which shows the shaping | molding apparatus in a magnetic field in the shaping | molding process in a magnetic field, (a) shows the state in which the type | mold was closed, (b) shows the state in the process in a magnetic field, respectively. It is a plane schematic diagram which shows the lower mold | type of the shaping | molding apparatus in a magnetic field. It is a principal part enlarged view of the said lower mold | type. It is a principal part enlarged view of the said lower mold | type which concerns on a modification. It is a perspective view of the magnet manufactured using the lower mold | type of FIG. It is a top view of the other rotor applied to the said axial gap type motor.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

(Structure of axial gap type motor)
Before describing the manufacturing method of the anisotropic magnet according to the present invention, first, an axial gap type motor to which the anisotropic magnet manufactured by the manufacturing method is applied will be described.

  FIG. 1 is an exploded perspective view of an axial gap type motor.

  As shown in the figure, the axial gap type motor 1 (hereinafter abbreviated as “motor 1”) is located between a rotor 2 having a rotating shaft 14 as a center and a pair of rotor bodies 16a and 16b described later. A so-called two-rotor comprising a stator 4 facing the rotor bodies 16a and 16b at a predetermined interval in the axial direction of the rotary shaft 14 and a cylindrical case 6 in which the rotor 2 and the stator 4 are accommodated. This is a single stator type motor. In the description herein, the direction parallel to the rotation shaft 14 is referred to as “axial direction”, the direction orthogonal to the rotation shaft 14 is referred to as “radial direction”, and the rotation direction of the rotation shaft 14 (rotor 2) is referred to as “circumferential direction”. .

  The stator 4 includes a plurality of stator cores 10 arranged in the circumferential direction, and a coil 12 that is attached (wound) to each stator core 10.

  On the other hand, the rotor 2 includes a pair of disk-shaped rotor main bodies 16a and 16b and a rotating shaft 14 penetrating through the centers of the rotor main bodies 16a and 16b. The rotating shaft 14 passes through the center of the stator 4, and the rotor main bodies 16 a and 16 b are fixed to the rotating shaft 14 at positions on both sides in the axial direction of the stator 4. The rotary shaft 14 is inserted into a bearing held by the end plate 6 b described later of the case 6, and is thereby supported by the case 6 so as to be rotatable relative to the rotor 2.

  FIG. 2 is a plan view of the rotor body 16a, and FIG. 3 is a cross-sectional view of the rotor body 16a. The pair of rotor bodies 16a and 16b has the same basic structure except that the fixing direction to the rotating shaft 14 is different. Therefore, here, the configuration of one rotor body 16a will be described.

  As shown in FIGS. 2 and 3, the rotor body 16 a includes a magnet holder 20, a rotor core 22 accommodated in the magnet holder 20, a plurality of (eight in this example) permanent magnets 24, and each permanent magnet 24. And a clamp member 26 fixed to the magnet holder 20.

  The magnet holder 20 has a circular and dish shape having an inner cylinder portion 21a, an outer cylinder portion 21b, and a bottom portion 21c, and is integrally formed of a nonmagnetic material (austenite stainless steel, aluminum, etc.). . An annular groove formed by the inner cylinder part 21a, the outer cylinder part 21b and the bottom part 21c is provided on the stator facing surface of the magnet holder 20, and the rotor core 22 and the permanent magnet 24 are accommodated in the groove part. ing.

  The rotor core 22 is formed in a substantially disk shape by winding a strip-shaped electromagnetic steel sheet in a spiral shape, and is fixed to the inner bottom surface of the groove portion of the magnet holder 20.

  The plurality of permanent magnets 24 have the same shape, and have a substantially fan shape in plan view and a flat shape (flat in the axial direction). These permanent magnets 24 are arranged on the rotor core 22 so as to be aligned in the circumferential direction along the inner cylinder portion 21a and the outer cylinder portion 21b of the magnet holder 20, and are fixed to the rotor core 22 with a magnetically permeable adhesive. Yes.

  Adjacent permanent magnets 24 are magnets having different magnetic poles, and are arranged in a circumferential direction with a certain gap as shown in FIG. 4, and the adjacent permanent magnets 24 are integrated as a set by the clamp member 26. In particular, it is fixed to the magnet holder 20. Specifically, as shown in FIG. 3, the clamp member 26 is formed in a U shape when viewed from the side, and the clamp member 26 is located at the end of each permanent magnet 24 in the circumferential direction at a pair of adjacent permanent magnets. The magnet 24 and the magnet holder 20 are attached to the magnet holder 20 from the outside in the radial direction so as to be held together.

  As shown in FIG. 4, step portions 24 a extending in the radial direction are formed at both ends in the circumferential direction of each permanent magnet 24. A groove (not shown) extending in the axial direction is formed at a position corresponding to the stepped portion 24a on the outer peripheral surface of the magnet holder 20 (the outer peripheral surface of the outer cylinder portion 21b), and the lower surface (bottom portion) of the magnet holder 20 is formed. A groove 21d extending in the radial direction is formed at a position corresponding to the stepped portion 24a in the lower surface of 21c. The clamp member 26 is engaged with the stepped portion 24 b while being interposed between the adjacent permanent magnets 24 and is fitted into the groove 21 d of the magnet holder 20. Thereby, the surface of each clamp member 26 and the surfaces of the magnet holder 20 and the permanent magnet 24 are flush with each other.

  The rotor body 16a is fixed to the rotating shaft 14 in a state where the rotating shaft 14 is inserted inside the inner cylinder portion 21a. Specifically, as shown in FIG. 3, a flange portion 14 a is provided at an intermediate portion of the rotating shaft 14, and the rotor body 16 a is in contact with the flange portion 14 a via a ring member 29. Although not shown in detail, a fixing member 28 such as a nut member is attached to the rotating shaft 14 from the opposite side of the rotor main body 16a, so that the rotor main body 16a is supported by the fixing member 28 and the flange portion 14a. It is fixed to the rotating shaft 14 while being sandwiched in the axial direction. In addition, although illustration is abbreviate | omitted, the inner cylinder part 21a and the rotating shaft 14 of the magnet holder 20 are stopped by key coupling.

  In the state where the rotor main body 16a is fixed to the rotary shaft 14 in this way, as shown in FIG. 3, the flange portions 26a and 26b formed at the tip of the clamp member 26 are respectively fixed by the fixing member 28 and the ring member 29. With this configuration, the magnet holder 20, the permanent magnet 24, and the rotor core 22 are firmly fixed by the clamp members 26.

  The case 6 includes a cylindrical portion 6a that covers the rotor 2 and the stator 4 and a pair of end plates 6b that are fixed to both ends of the cylindrical portion 6a.

  In the motor 1, when a predetermined current is applied to each coil 12, a magnetic flux is formed between the coil 12 and the permanent magnet 24 as shown in FIG. 4. In this case, according to the structure of the motor 1, a gap is formed between adjacent permanent magnets 24, so that the generated magnetic flux passes from the permanent magnets 24 through the rotor core 22 as shown in FIG. Toward the adjacent permanent magnet 24. Therefore, the generation of a magnetic flux that is short-circuited from the permanent magnet 24 to the adjacent permanent magnet 24 is suppressed, and a decrease in rotational torque due to the short-circuit of the magnetic flux is suppressed.

  An anisotropic magnet is applied to the rotor 2 as each permanent magnet 24. Specifically, the magnetic flux is formed by energizing the coil 12 so as to spread from the magnet central part (circumferential center part) to both sides in the thickness direction of the permanent magnet 24 as indicated by broken line arrows in FIG. A magnet having anisotropy (anisotropic magnet) is applied.

  The motor 1 has a structure in which the permanent magnets 24 of the rotor 2 are separated from each other. However, when each permanent magnet 24 is manufactured individually, the anisotropy of adjacent permanent magnets 24 is accurately determined. It becomes difficult to maintain well, and as a result, the surface magnetic flux between the adjacent permanent magnets 24 is likely to change, and the cogging torque and the torque clip may be increased. Therefore, the permanent magnet 24 applied to the rotor 2 is manufactured based on the manufacturing method described below and incorporated in the rotor 2 in order to eliminate such inconvenience.

(Manufacturing method of permanent magnet 24 and manufacturing method of rotor 2)
The permanent magnet 24 is a neodymium sintered magnet in this example. Therefore, first, a manufacturing method (manufacturing process) of a neodymium-based sintered magnet will be described.

  FIG. 5 is a process diagram showing a method for producing a neodymium sintered magnet. As shown in the figure, the neodymium-based sintered magnet includes a magnet material manufacturing process, a magnetic field molding process, a sintering / heat treatment process, a processing / surface treatment process, and a magnetization process.

1) Magnet material manufacturing process By blending neodymium (Nd), iron (Fe) boron (B), etc., which are raw materials for neodymium magnets, these are melted in a melting furnace (melted at about 1250 ° C). It is alloyed and poured into a mold to produce an ingot. Thereafter, the ingot is pulverized to a differential powder of about several microns (for example, 3 to 5 μm) through a plurality of stages. Thereby, magnet powder (magnet material) is manufactured.

2) Molding process in a magnetic field Magnet powder is filled in a mold, and the magnetic powder is pressed by a mold while forming a magnetic field (magnetic field) by a magnetic field coil. As a result, the crystal direction of the magnet powder is aligned with the magnetic field direction (the easy magnetization direction is aligned with the magnetic field direction), and a green compact having magnetic properties with anisotropy in the magnetic field direction is molded.

  In addition, the manufacturing method of the said permanent magnet 24 which concerns on this invention has the characteristics mainly in this formation process in a magnetic field, and this point is explained in full detail behind.

3) Sintering / heat treatment process,
The compacted compact molded in the molding process in a magnetic field is sintered and heat-treated in a vacuum sintering furnace. For example, the compacted compact is sintered at 1000 ° C. to 1200 ° C. and then heat-treated at about 600 ° C.

4) Processing / Surface Treatment Step By subjecting the sintered compacted body to a polishing process or the like, the oxide layer on the surface is removed and the compacted compact is shaped. Then, surface treatment for rust prevention, such as nickel plating, is performed.

5) Magnetization process The compacted compact after surface treatment is set in a magnetizing device, and the compacted compact is magnetized by a strong magnetic field formed by a magnetic field coil. This completes the neodymium magnet.

  Next, the process of the above-described forming step in a magnetic field will be described in detail.

  6 (a) and 6 (b) schematically show, in cross-sectional view, a magnetic field molding apparatus used in the magnetic field molding step, and (a) shows a lower mold of the magnetic field molding apparatus, (B) has shown the shaping | molding apparatus in the magnetic field of the state which opened the type | mold.

  As shown in these drawings, the magnetic field molding apparatus 30 includes a mold 31 including a lower mold 31A that is a fixed mold and an upper mold 31B that is a movable mold, and a drive device that opens and closes the mold 31. ing. In this example, the lower mold 31A corresponds to the first mold of the present invention, and the upper mold 31B corresponds to the second mold of the present invention.

  As shown in FIGS. 6A and 8, the lower mold 31A includes a lower mold body 32 (a gold mold according to the present invention) having a plurality of recesses 33 that constitute a cavity for magnet molding together with a post-projection 43 of the upper mold 31B. A plurality of magnetic fields interposed between the lower mold main body 32 and the base 34 at the positions of the recesses 33, respectively. And a coil 36.

  The concave portions 33 of the lower mold main body 32 are formed at equal intervals in the circumferential direction, and each has a substantially fan shape in plan view corresponding to the permanent magnet 24 and is slightly less than twice the thickness dimension of the permanent magnet 24. Has a depth of. The number and arrangement of the recesses 33 correspond to the number and arrangement of the plurality of permanent magnets 24 incorporated in the rotor 2.

  As shown in the figure, the lower mold body 32 has a position on the upper side (or a position slightly above it) as much as the thickness of the permanent magnet 24 from the inner bottom of the recess 33, and is below the boundary position. The (lower part 32a) is made of a nonmagnetic material, and the upper side (upper part 32b) is made of a soft magnetic material.

  The base 34 also serves as a back yoke for the magnetic field coil 36 and is formed of a soft magnetic material.

  The magnetic field coil 36 includes a core 37 and a coil body 38 wound on the outer peripheral surface thereof. The core 37 passes through the bottom wall of the lower mold body 32 and is provided so that the end surface thereof is flush with the inner bottom surface of the recess 33. Thereby, a part of the inner bottom surface of the recess 33 is formed by the core 37. As shown in FIG. 9, the core 37 has a substantially fan-like shape in plan view that is narrower than the recess 33, and is disposed at the center of the recess 33 in the circumferential direction of the lower mold body 32. . The area of the end surface of the core 37 facing the recess 33, that is, the interlinkage magnetic flux surface 37a is 10% to 50% of the area of the inner bottom surface of the recess 33 (that is, the interlinkage magnetic flux surface (stator facing surface) of the permanent magnet 24). It is preferable to be within the range of%. This is because the interlinkage magnetic flux surface 37a of the core 37 needs to be at least about 10% of the area of the interlinkage magnetic flux surface of the permanent magnet 24 in order to secure the amount of magnetic flux generated by the magnetic field coil 36, and exceeds 50%. This is because the anisotropic magnetization orientation may be disturbed.

  On the other hand, as shown in FIG. 6B, the upper die 31B includes an upper die body 42 having a plurality of convex portions 43 that protrude downward at positions corresponding to the respective concave portions 33 of the lower die 31A. And an oscillator 44 fixed to the upper mold main body 42. The upper mold 31B is connected to the driving device and is moved up and down by being driven by the driving device. In this way, the upper and lower molds 31B move up and down relative to the lower mold 31A, so that the mold 31 is opened and closed.

  Each convex portion 43 of the upper mold main body 42 has a substantially sector shape in plan view corresponding to each concave portion 33 of the lower mold main body 32, and the concave portion 33 and the convex portion 43 form a cavity for forming a magnet. Is done. Reference numeral 42 a in the drawing is a horn provided on the upper portion of each convex portion 43. In the upper die main body 42, only the plurality of convex portions 43 are formed of a soft magnetic material, and the other portions are formed of a nonmagnetic material.

  The vibrator 44 applies vibration to the upper mold main body 42. In this example, the vibrator 44 is an ultrasonic vibrator and is fixed to the upper part of the upper mold body 42.

  In this example, the step of preparing the magnetic field molding device 30 corresponds to the preparation step of the present invention, and the processing using the magnetic field molding device 30 corresponds to the magnetic field molding step of the present invention.

  The details of the processing in the magnetic field molding process using the magnetic field molding device 30 as described above (referred to as molding in the magnetic field as appropriate) are as follows. First, as shown in FIG. 6B, in a state where the mold 31 is opened, the magnet powder (magnet material) manufactured in the magnet material manufacturing process is filled in each recess 33 of the lower mold body 32, and then As shown in FIG. 7A, the mold 31 is closed by lowering the upper mold 31B.

  And while pressing the magnetic powder in the recessed part 33 with the metal mold | die 31, and supplying electric power to all the magnetic field coils 36, a magnetic field (magnetic field) is formed by each magnetic field coil 36. FIG. Thereby, the crystal directions of the magnet powder in each concave portion 33 are aligned with the magnetic field direction (the easy magnetization direction is aligned with the magnetic field direction), and the eight compacts having magnetic properties with anisotropy in the magnetic field direction are provided. The molded body Cp is molded at the same time. At this time, as shown in FIG. 7 (b), powers of opposite phases are supplied to the adjacent magnetic field coils 36 so that the adjacent magnetic field coils 36 have different magnetic poles. In this way, as indicated by the broken line arrow in the figure, a magnetic field in which the magnetic flux passes in a loop shape in a certain direction over the magnet powder of the specific recess 33 and the magnet powder of the recess 33 adjacent to the magnet powder. As a result, the crystal directions of the magnet powders in the recesses 33 adjacent to each other are aligned in opposite directions. That is, the magnet powder in the adjacent concave portion 33 is given anisotropy (magnetic characteristics) in opposite directions corresponding to the magnetic poles of the magnetic field coil 36.

  When the magnet powder is pressed, the vibrator 44 is driven, and the upper die main body 42 and the lower die main body 32 are ultrasonically vibrated integrally. Thereby, the movement of the magnet powder during pressing is promoted, and the alignment of the crystal direction in the magnetic field direction is promoted.

  The above is the molding process in a magnetic field. The eight compacts Cp thus molded are then subjected to the above-described sintering / heat treatment process, processing / surface treatment process, and magnetizing process, whereby the rotor 2 is subjected to the above processes. A set of eight permanent magnets 24 to be incorporated is manufactured.

  Then, the eight permanent magnets 24 manufactured in this way (corresponding to the magnet manufacturing process of the present invention) are incorporated into the common rotor bodies 16a and 16b (corresponding to the assembling process of the present invention). Specifically, in the state in which the surface of the permanent magnet 24 facing the magnetic field coil 36 side in the molding process in the magnetic field faces the stator 4 side, the same set as the array in the molding process in the magnetic field is used. Each permanent magnet 24 is fixed on the rotor core 22.

  According to the rotor 2 (rotor bodies 16a, 16b) having such a configuration, the eight permanent magnets 24 are incorporated in the rotor 2 in the same arrangement as that in the magnetic field molding step, so that the permanent magnets adjacent to each other are arranged. The anisotropy of the magnet 24 is favorable. Therefore, the surface magnetic flux between adjacent permanent magnets 24 hardly changes, and the generation of cogging torque and torque clips is effectively suppressed.

  As described above, according to the method of manufacturing the permanent magnet 24, in the magnetic field molding step, the magnetic field is formed so that the magnetic flux passes through the magnet powder (magnet material) filled in the cavities adjacent to each other. Are aligned along this magnetic field (that is, the magnetic material is aligned along the magnetic field so as to align the easy magnetization direction). Therefore, it is possible to manufacture a plurality of permanent magnets 24 that are simultaneously used in the rotor 2 (rotor bodies 16a and 16b) while ensuring the anisotropy of adjacent permanent magnets 24 with high accuracy.

  In particular, in the method for manufacturing the permanent magnet 24, the lower die body 32A is provided with an upper portion 32b made of a nonmagnetic material and an upper portion 32b made of a soft magnetic material, as shown in FIG. ), The magnetic field molding process is performed with the soft magnetic body (upper part 32b) interposed between the adjacent convex parts 43 of the upper die main body 42, so that it has anisotropy. The permanent magnet 24 can be manufactured with high accuracy. That is, since the soft magnetic body (upper part 32b) is interposed between the adjacent convex parts 43 of the upper die main body 42, the convex part 43 and the soft magnetic body (upper part) are shown in FIG. A good magnetic field can be formed through which the magnetic flux passes through 32b) to the magnet material in the adjacent cavities. Therefore, as shown in FIG. 4, the permanent magnet 24 having anisotropy through which magnetic flux passes can be accurately manufactured.

  Furthermore, according to the manufacturing method of the permanent magnet 24, ultrasonic vibration is applied to the magnet powder during the molding process in the magnetic field, thereby promoting the alignment of the crystal direction of the magnet powder in the magnetic field direction (the magnet powder is easily magnetized). Therefore, there is also an advantage that a good permanent magnet 24 with high anisotropy accuracy can be manufactured. In this example, the ultrasonic vibration is applied to the magnet powder. However, the vibration may be a vibration other than the ultrasonic vibration as long as the alignment of the crystal direction of the magnet powder in the magnetic field direction can be promoted. .

  The manufacturing method of the permanent magnet 24 and the manufacturing method of the rotor 2 described above are exemplifications of preferred embodiments of the manufacturing method of the anisotropic magnet and the manufacturing method of the rotor according to the present invention. The present invention can be changed as appropriate without departing from the gist of the present invention.

(Modifications, etc.)
(1) As shown in FIG. 10, as the lower mold body 32 of the lower mold 31A, a plurality of arc-shaped partition plates 33a are arranged in parallel in the radial direction (the radial direction of the lower mold body 32) on the inner bottom portion of each recess 33. You may make it perform the shaping | molding process in a magnetic field using what was provided. According to this manufacturing method, as shown in FIG. 11, the permanent magnet 24 in which arc-shaped grooves 24 b arranged in parallel to each other are formed on the stator facing surface (linkage magnetic flux surface) of the permanent magnet 24. Is possible.

  According to such a permanent magnet 24, since a plurality of grooves 24b are formed and the stator facing surface (linkage magnetic flux surface) is subdivided, generation of eddy current is suppressed. Therefore, there is an advantage that the permanent magnet 24 capable of further reducing the eddy current loss while ensuring good anisotropy can be manufactured.

  (2) In the above embodiment, the manufacturing method of the permanent magnet 24 used for the rotor 2 of the axial gap motor 1 and the manufacturing method of the rotor 2 have been described as application examples of the present invention. Is applicable to the manufacture of permanent magnets and rotors used in the rotors of radial gap motors. Further, the present invention is not limited to the motor, and can be applied to the manufacture of permanent magnets and rotors used in the rotors of the generator.

  (3) In the above embodiment, the permanent magnet 24 is a neodymium-based sintered magnet, but may be a magnet other than this, for example, a neodymium-based bonded magnet. The specific manufacturing process of the neodymium-based bonded magnet is slightly different from that of the neodymium-based sintered magnet, but basically the magnet is used by using an apparatus equivalent to the in-field molding apparatus 30 shown in FIGS. 6 (a) and 6 (b). It can be manufactured by subjecting the material to a molding process in a magnetic field and subjecting the molded body to a magnetizing process.

  (4) In the above embodiment, as shown in FIG. 4, a method for manufacturing the permanent magnet 24 incorporated in the rotor 2 (rotor bodies 16a, 16b) of the type in which the permanent magnets 24 are arranged in the circumferential direction with a gap therebetween. As described above, in this method, as shown in FIG. 12, a plurality of permanent magnets 24 and soft magnetic bodies 25 are alternately arranged in the circumferential direction, whereby the rotor 2 configured to gain reluctance torque. This method can be applied to the method for manufacturing the permanent magnet 24 and the soft magnetic body 25.

  That is, the permanent magnet 24 is manufactured based on the process shown in FIG. Separately from this, the soft magnetic body 25 is manufactured based on other processes except the magnetizing process in the processes shown in FIG. In this case, in the magnetic field forming step, the mold 1 in which cavities (concave portions 33 and convex portions 43) having a shape corresponding to the soft magnetic body 25 are arranged in the circumferential direction is used, and the soft magnetic material is used as the cavity instead of the magnet material. Fill and perform the molding process in a magnetic field.

  According to such a manufacturing method of the soft magnetic body 25, in the molding process in the magnetic field, the magnetic field is formed so that the magnetic flux passes through the soft magnetic materials filled in the cavities adjacent to each other, and the crystal direction of the soft magnetic material is Align along the magnetic field (ie align the soft magnetic material along the magnetic field so that the easy magnetization directions are aligned). Therefore, it is possible to manufacture a plurality of soft magnetic bodies 25 that are used simultaneously in the rotor 2 while accurately ensuring the anisotropy of the adjacent soft magnetic bodies 25. According to the soft magnetic body 25 configured as described above, the magnetic flux in the soft magnetic body 25 easily flows in the direction of easy magnetization, and the cogging torque and the torque clip are suppressed by controlling the surface magnetic flux waveform. You can earn reluctance torque.

  Then, the plurality of permanent magnets 24 and the plurality of soft magnetic bodies 25 manufactured as described above are incorporated into the rotor 2 in the same arrangement as in the magnetic field molding step.

  According to the rotor 2 having such a configuration (FIG. 12), the permanent magnets 24 and the soft magnetic bodies 25 interposed therebetween are combined into the rotor 2 while being arranged in the respective magnetic field forming steps. Since it is incorporated, it is possible to ensure a good without impairing the anisotropy of the permanent magnet 24 and the soft magnetic body 25 adjacent to each other. Further, the surface magnetic flux waveform of the rotor 2 can be made close to a sine waveform with respect to the magnet torque and the reluctance torque, which is effective in reducing cogging torque and torque clip.

DESCRIPTION OF SYMBOLS 1 Axial gap type motor 2 Rotor 4 Stator 24 Permanent magnet 30 Magnetic field molding apparatus 31 Mold 31A Lower mold (1st type)
31B Upper mold (second mold)
32 Lower mold body 33 Concave part 34 Base 36 Magnetic coil 42 Upper mold body 43 Convex part

Claims (10)

A method of manufacturing the plurality of magnets used in a rotor provided with a plurality of magnets arranged at intervals in the circumferential direction and having anisotropy respectively.
A mold body made of a non-magnetic material having a plurality of recesses as many as the magnets, arranged at intervals in the circumferential direction, and a plurality of magnetic field coils provided at positions respectively corresponding to the recesses of the mold body. A preparation step of preparing a mold including a first mold provided and a second mold provided with a plurality of convex portions made of a soft magnetic material that form a cavity together with the plurality of concave portions;
Each concave portion of the mold body is filled with a magnet material and clamped, and a molded body is formed by compressing the magnet material in each cavity while forming magnetic fields with different magnetic poles by magnetic field coils adjacent to each other. A molding process in a magnetic field;
A method for producing an anisotropic magnet, comprising: a magnetizing step of magnetizing a molded body formed in the molding step in the magnetic field. In the manufacturing method of the anisotropic magnet of Claim 1,
In the said magnetic field shaping | molding process, a soft-magnetic body is interposed between the said adjacent convex parts, The manufacturing method of the anisotropic magnet characterized by the above-mentioned. In the manufacturing method of the anisotropic magnet of Claim 1 or 2,
In the magnetic field forming step, the magnet material in each cavity is vibrated, and the anisotropic magnet manufacturing method is characterized in that: In the manufacturing method of the anisotropic magnet of Claim 3,
A method for producing an anisotropic magnet, wherein ultrasonic vibration is applied to a magnet material. In the manufacturing method of the anisotropic magnet as described in any one of Claims 1 thru | or 4,
The rotor is a rotor of an axial gap type rotating electrical machine, and each of the plurality of magnets has a substantially fan-like plate shape in plan view having a thickness in a rotation axis direction.
In the molding step in the magnetic field, the magnetic field is compressed in a direction corresponding to the thickness of the magnet, and the magnetic field is formed so that a magnetic flux passes through the magnet material in a direction parallel to the compression direction. A method for producing an anisotropic magnet. In the manufacturing method of the anisotropic magnet of Claim 5,
A method for producing an anisotropic magnet, wherein the magnetic flux coil has a shape of a flux linkage surface of a core that is substantially fan-shaped in plan view. A method for producing a rotor comprising a plurality of magnets arranged at intervals in the circumferential direction and each having anisotropy,
A magnet manufacturing process for manufacturing the plurality of magnets using the anisotropic magnet manufacturing method according to any one of claims 1 to 6;
An assembly process for incorporating the plurality of magnets manufactured in the magnet manufacturing process into the rotor in an arrangement at the time of the magnetic field molding process performed in the magnet manufacturing process. Rotor manufacturing method. A method for producing a plurality of soft magnetic materials having anisotropy,
A first mold comprising a mold body made of a non-magnetic material having a plurality of recesses arranged in the circumferential direction, and a plurality of magnetic field coils installed at positions corresponding to the recesses of the mold body; A preparation step of preparing a mold including a second mold having a plurality of convex portions made of a soft magnetic material that forms a cavity together with the concave portions;
By filling the concave portion of the mold body with a soft magnetic material and clamping it, and compressing the soft magnetic material in each cavity while forming magnetic fields with different magnetic poles by magnetic coils adjacent to each other, anisotropy is achieved. A method for producing an anisotropic soft magnetic material, comprising: a molding step in a magnetic field for forming a plurality of molded products that are a plurality of soft magnetic materials having a magnetic field. In the manufacturing method of the anisotropic soft magnetic material according to claim 8,
The method for producing an anisotropic soft magnetic material, wherein the soft magnetic material in each cavity is vibrated in the molding step in the magnetic field. A method of manufacturing a rotor comprising a plurality of magnets having anisotropy and a plurality of soft magnetic bodies having anisotropy, wherein the magnets and the soft magnetic bodies are alternately arranged in a circumferential direction,
A plurality of magnets having anisotropy manufactured using the method for manufacturing an anisotropic magnet according to any one of claims 1 to 6, and an anisotropic soft magnet according to claim 8 or 9. A rotor manufacturing method for a rotating electrical machine, wherein a plurality of anisotropic soft magnetic bodies manufactured using a magnetic body manufacturing method are incorporated into the rotor.

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