Apparatus for molding oriented magnet and plastic magnet in magnetic field

Abstract

To provide an oriented magnet which is formed by combining a plurality of members and has good dimensional accuracy, and to provide an apparatus for molding a plastic magnet using the oriented magnet in a magnetic field.SOLUTION: The oriented magnet 200 is an oriented magnet formed by combining a first member 210 and a second member 220. The first member and the second member are combined with each other such that the first surface 212 of the first member and the second surface 222 of the second member face and contact each other. The first member has a protrusion 214 protruding from the first surface toward the second member. The second member has a recess 224 which is recessed from the second surface in a direction away from the first member and into which the projection is fitted.SELECTED DRAWING: Figure 5B

Description

[Technical Field]

[0001] The present invention relates to an orienting magnet and a magnetic field molding device for plastic magnets that is equipped with the orienting magnet. [Background technology]

[0002] Conventionally, as in Patent Document 1 (Japanese Patent Laid-Open Publication No. 2001-267164), an oriented magnet is known that is manufactured by joining a plurality of members with an adhesive and is used in a magnetic field molding device for plastic magnets.

[0003] By using the method of Patent Document 1 (Japanese Patent Application Laid-Open No. 2001-267164), it is possible to increase the size of the oriented magnets, and by using the increased size of the oriented magnets to manufacture large rotors using plastic magnets, it is possible to manufacture high-output motors. Summary of the Invention [Problem to be solved by the invention]

[0004] However, with magnets having a structure such as that of Patent Document 1 (Japanese Patent Laid-Open Publication No. 2001-267164), it is difficult to control the thickness of the adhesive, and there is a risk that variations in the size of the oriented magnets will occur.

[0005] To make the size of oriented magnets uniform, it is possible to perform machining after bonding with adhesive, but when forming oriented magnets by joining two parts with adhesive, the adhesive does not conduct electricity, so wire EDM cutting, which is suitable for machining oriented magnets, cannot be used. [Means for solving the problem]

[0006] The oriented magnet of a first aspect is an oriented magnet formed by combining a first member and a second member. The first member and the second member are combined so that a first surface of the first member and a second surface of the second member face each other and contact each other. The first member has a convex portion that protrudes from the first surface toward the second member. The second member has a concave portion that is recessed from the second surface in a direction away from the first member and into which the convex portion fits.

[0007] In the oriented magnet of the first aspect, by providing a convex portion on the first member and a concave portion on the second member into which the convex portion fits, it is possible to prevent the first member and the second member from becoming misaligned in a direction along the first surface of the first member and the second surface of the second member. Therefore, in the oriented magnet of the first aspect, the oriented magnet can be manufactured with good dimensional accuracy by combining multiple members without using adhesive.

[0008] The oriented magnet of a second aspect is the oriented magnet of the first aspect, wherein the orientation direction of the oriented magnet is perpendicular to the first and second surfaces, and the magnetic poles of the first surface and the second surface are opposite magnetic poles.

[0009] In the oriented magnet of the second aspect, the magnetic poles on the first surface and the second surface are opposite magnetic poles, so an attractive force acts between the first surface and the second surface. Therefore, in the oriented magnet of the second aspect, misalignment between the combined first and second members is easily suppressed.

[0010] An aligning magnet according to a third aspect is the aligning magnet according to the first or second aspect, wherein the recess has a restricting portion that restricts movement of the protrusion in a direction perpendicular to the second surface.

[0011] In the oriented magnet of the third aspect, the recessed portions restrict movement of the protruding portions in a direction perpendicular to the second surface, so that the combined first and second members are less likely to come apart.

[0012] The oriented magnet of a fourth aspect is the oriented magnet of any one of the first aspect to the third aspect, wherein the convex portion extends in a direction perpendicular to the first surface from a first end portion, which is a connection portion with the first surface, to a second end portion. When the convex portion is viewed from a first direction parallel to the first and second surfaces, the convex portion has a first portion at the second end portion or between the first end portion and the second end portion. The width of the first portion of the convex portion in the second direction, which is parallel to the first surface and perpendicular to the first direction, is wider than the width of the first end portion in the second direction.

[0013] In the oriented magnet of the fourth aspect, when the protrusion is viewed along the first direction, the protrusion has a first portion at the second end or between the first end and the second end that is wider than the width of the first end, and the recess into which the protrusion fits has a shape that corresponds to the protrusion. Therefore, in the oriented magnet of the fourth aspect, the first member and the second member are prevented from moving away from each other.

[0014] The aligning magnet of a fifth aspect is the aligning magnet of the fourth aspect, and the first direction is the alignment direction of the aligning magnet.

[0015] In the oriented magnet of the fifth aspect, the orientation direction is parallel to the first and second surfaces, so a repulsive force acts between the first and second surfaces. However, here, even if a repulsive force acts between the first and second surfaces, the convex and concave portions prevent the first and second members from moving away from each other.

[0016] The oriented magnet of a sixth aspect is the oriented magnet of any one of the first aspect to the fifth aspect, which is made of samarium cobalt.

[0017] Samarium-cobalt magnets have excellent properties such as strong magnetic force and can be used at relatively high temperatures.

[0018] On the other hand, grinding is not suitable for samarium-cobalt oriented magnets, and when forming an oriented magnet by joining two members with an adhesive, as in Patent Document 1 (JP 2001-267164 A), wire discharge cutting cannot be used because the adhesive does not conduct electricity. Therefore, when forming an oriented magnet made of samarium-cobalt by joining two members with an adhesive, it is difficult to perform the necessary machining on the oriented magnet.

[0019] In contrast, the oriented magnet of the present disclosure does not use adhesive when combining the two components, so even with an oriented magnet made of samarium-cobalt, the occurrence of such problems can be suppressed.

[0020] A seventh aspect of the present invention relates to a magnetic field molding device for plastic magnets, which includes a mold and an oriented magnet according to any one of the first to sixth aspects. Molten plastic magnet raw material is supplied into the mold. The oriented magnet is placed within the mold.

[0021] The magnetic field molding apparatus for plastic magnets according to the seventh aspect makes it possible to manufacture large motors. [Brief explanation of the drawings]

[0022] [Figure 1A] FIG. 1A is a schematic vertical cross-sectional view of an apparatus for molding a plastic magnet in a magnetic field according to one embodiment. [Figure 1B] FIG. 1B is a bottom view of the inner mold of the magnetic field molding apparatus of FIG. 1A, seen from below. [Figure 1C] 1C is an exploded perspective view illustrating the inner mold of the magnetic field molding apparatus of FIG. 1A and a plastic magnet molded by the magnetic field molding apparatus of FIG. 1A. [Figure 2A] FIG. 2A is a schematic vertical cross-sectional view of a magnetic field molding apparatus for plastic magnets according to another embodiment. [Figure 2B] FIG. 2B is a bottom view of the bottom mold of the magnetic field molding apparatus of FIG. 2A, seen from below. [Figure 3A] 1B is a schematic cross-sectional view of a radial motor using a plastic magnet formed by the magnetic field molding apparatus of FIG. 1A, taken along a plane along the rotation axis. [Figure 3B] 3B is a view of the rotor of the radial motor of FIG. 3A viewed along the direction of the rotation axis. [Figure 4A] 2B is a schematic cross-sectional view of an axial motor using a plastic magnet formed by the magnetic field molding apparatus of FIG. 2A, taken along a plane along the rotation axis. FIG. [Figure 4B] 4B is a view of the rotor of the axial motor of FIG. 4A as viewed along the direction of the rotation axis. [Figure 5A] FIG. 2 is a schematic perspective view of an example of an aligning magnet used in a magnetic field molding device. [Figure 5B]FIG. 5B is a schematic plan view of the orienting magnet of FIG. 5A. [Figure 6A] FIG. 10 is a schematic perspective view of another example of an aligning magnet used in a magnetic field molding device. [Figure 6B] FIG. 6B is a schematic plan view of the orienting magnet of FIG. 6A. [Figure 7A] FIG. 10 is a schematic perspective view of an aligning magnet according to Modification A. [Figure 7B] FIG. 7B is a schematic plan view of the orienting magnet of FIG. 7A. [Figure 8] FIG. 10 is a schematic perspective view of an aligning magnet according to Modification B. [Figure 9] FIG. 10 is a side view of a first member of an aligning magnet according to modification C. [Figure 10] FIG. 10 is a side view of the first member of the aligning magnet according to modification D. [Figure 11] FIG. 10 is a schematic perspective view of an aligning magnet according to Modification Example E. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, the oriented magnet of the present disclosure and a magnetic field molding device for plastic magnets (also called bonded magnets) equipped with the oriented magnet will be described with reference to the drawings.

[0024] (1) Magnetic field molding equipment for plastic magnets The magnetic field molding device for plastic magnets is a device that heats and melts plastic magnet raw materials, supplies the plastic magnet raw materials to a mold, cools them, and molds a plastic magnet. Orientation magnets formed into a predetermined shape are placed in a predetermined arrangement within the mold of the magnetic field molding device for plastic magnets. The orientation direction of the plastic magnet is aligned by molding the molten plastic magnet in the magnetic field of the orienting magnets.

[0025] Plastic magnet raw materials are made by dispersing and mixing magnetic powder in a resin binder. Examples of plastic magnet raw materials include, but are not limited to, ferrite-based materials that use magnetic powder mainly composed of iron oxide, rare earth-based materials that use magnetic powder mainly composed of neodymium, iron, and boron, rare earth-based materials that use samarium-cobalt as the magnetic powder, and hybrid materials that mix neodymium magnetic powder and ferrite magnetic powder.

[0026] Plastic magnets have excellent features such as a high degree of freedom in shape and the ability to reduce the weight of parts. Plastic magnets are used, for example, in motor rotors. A specific example will be explained.

[0027] Fig. 3A is a schematic cross-sectional view of a radial motor 10 using a plastic magnet 22, taken along a plane along the rotation axis. Fig. 3B is a view of the rotor 20 of the motor 10 as seen along the rotation axis. Although not limited to this, the motor 10 is an outer rotor type motor.

[0028] The motor 10 in which the plastic magnet 22 is used mainly includes a rotor 20 and a stator 30 .

[0029] The rotor 20 has plastic magnets 22 arranged radially outward of the stator 30. A motor rotating shaft 24 is fixed to the inner periphery of the rotor 20. As shown in FIG. 3B, the plastic magnets 22 have north and south poles arranged alternately in the circumferential direction.

[0030] When a current flows through the coil of the stator 30, a magnetic field is generated, causing the rotor 20, which has the plastic magnets 22 arranged around the stator 30, to rotate. As a result, the motor shaft 24 attached to the rotor 20 rotates. For example, if the motor 10 is used as a fan, the rotation of the motor shaft 24 causes the impeller (not shown) fixed to the motor shaft 24 to rotate.

[0031] Fig. 4A is a schematic cross-sectional view of an axial motor 10A using a plastic magnet 22A, taken along a plane along the rotation axis. Fig. 4B is a view of rotor 20A of motor 10A as seen along the rotation axis.

[0032] A motor 10A using a plastic magnet 22A mainly includes a pair of rotors 20A and a stator 30A, as shown in FIG. 4A, for example.

[0033] A motor rotating shaft 24A is attached to the center of the pair of rotors 20A. When viewed in the axial direction of the motor rotating shaft 24A, plastic magnets 22A are arranged around the motor rotating shaft 24A of the rotor 20A, as shown in Figure 4B. When the rotor 20A is viewed along the rotation axis direction, north and south poles are arranged alternately in the circumferential direction around the motor rotating shaft 24A of the rotor 20A.

[0034] The stator 30A is disposed between a pair of rotors 20A spaced apart in the axial direction of the motor shaft 24A. When current flows through the coil of the stator 30A, a magnetic field is generated, causing the rotor 20A, which has the plastic magnet 22A, to rotate. As a result, the motor shaft 24A attached to the rotor 20A rotates, and if the motor 10A is used as a fan, for example, an impeller (not shown) fixed to the motor shaft 24A rotates.

[0035] Fig. 1A is a schematic longitudinal sectional view of a magnetic field molding apparatus 100 used to manufacture the plastic magnet 22 depicted in Figs. 3A and 3B. Fig. 1B is a bottom view of the internal mold 114 of the magnetic field molding apparatus 100, as viewed from below. Fig. 1C is an exploded perspective view depicting the internal mold 114 of the magnetic field molding apparatus 100 of Fig. 1A and the plastic magnet 22 molded by the magnetic field molding apparatus 100.

[0036] As shown in FIG. 1A, the magnetic field molding apparatus 100 mainly includes a mold 110 and an aligning magnet 200.

[0037] 1A, the mold 110 mainly includes a bottom mold 112, an inner mold 114, and an outer mold 116. A space S into which molten plastic magnet raw material is supplied is formed inside the mold 110. The bottom mold 112 surrounds the bottom of the space S, the inner mold 114 surrounds the inner periphery of the space S, and the outer mold 116 surrounds the outer periphery and top of the space S.

[0038] As shown in Figures 1A to 1C, the inner mold 114 is formed in a cylindrical shape. As shown in Figure 1C, the aligning magnets 200 are placed inside the mold 110, particularly in the recessed portion 115 of the inner mold 114. Specifically, a plurality of aligning magnets 200 are arranged in the circumferential direction in the recessed portion 115 of the inner mold 114. The orientation direction of each of the plurality of aligning magnets 200 is along the radial direction of the inner mold 114. The plurality of aligning magnets 200 are arranged in the circumferential direction on the outer circumferential surface of the inner mold 114 so that the north poles and south poles are alternately arranged (see Figure 1B).

[0039] In the example of Figure 1B, ten oriented magnets 200 are arranged in a circumferential direction inside the inner mold 114, but the number of oriented magnets 200 is not limited to ten, and the number of oriented magnets 200 may be determined appropriately depending on the configuration of the plastic magnet 22 to be created.

[0040] Heated and melted plastic magnet raw material is supplied into the space S of the mold 110 of the magnetic field molding device 100, and then the plastic magnet raw material is cooled to manufacture the rotor 20 equipped with the plastic magnets 22 depicted in Figures 3A and 3B. Thereafter, the outer mold 116 is removed, and the rotor 20 equipped with the plastic magnets 22 is removed from the mold 110.

[0041] Fig. 2A is a schematic longitudinal sectional view of a magnetic field molding apparatus 100A used to manufacture the plastic magnet 22A depicted in Fig. 4A and Fig. 4B. Fig. 2B is a bottom view of the bottom mold 112A of the magnetic field molding apparatus 100A as seen from below.

[0042] As shown in FIG. 2A, the magnetic field molding apparatus 100A mainly includes a mold 110A and an orienting magnet 200A.

[0043] As shown in Fig. 2A, the mold 110A mainly includes a bottom mold 112A and an outer mold 116A. A space S is formed inside the mold 110A, into which molten plastic magnet raw material is supplied. The bottom mold 112A surrounds the bottom of the space S, and the outer mold 116A surrounds the outer periphery and top of the space S.

[0044] As shown in FIGS. 2A and 2B, the bottom mold 112A is formed in a disk shape. The aligning magnet 200A is disposed inside the mold 110A, particularly inside the bottom mold 112A. Specifically, inside the bottom mold 112A, a plurality of aligning magnets 200A are arranged side by side in the circumferential direction. The orientation direction of each of the plurality of aligning magnets 200A is along the thickness direction (vertical direction) of the bottom mold 112A. When the bottom mold 112A is viewed from above, the plurality of aligning magnets 200A are arranged side by side in the circumferential direction so that north poles and south poles are alternately arranged in the bottom mold 112A.

[0045] In the example of Figure 2B, ten oriented magnets 200A are arranged circumferentially inside the bottom mold 112A, but the number of oriented magnets 200A is not limited to ten, and the number of oriented magnets 200A may be determined appropriately depending on the configuration of the plastic magnet 22A to be created.

[0046] Heated and melted plastic magnet raw material is supplied into the space S of the mold 110A of the magnetic field molding device 100A, and then the plastic magnet raw material is cooled to manufacture the rotor 20A equipped with the plastic magnets 22A depicted in Figures 4A and 4B. Thereafter, the outer mold 116A is removed, and the rotor 20A equipped with the plastic magnets 22A is removed from the mold 110A.

[0047] (2) Oriented magnet An embodiment of the aligning magnets 200 and 200A used in the magnetic field molding apparatuses 100 and 100A will be described.

[0048] Although there is no limitation on the material, aligning magnets 200 and 200A are samarium-cobalt magnets. Samarium-cobalt magnets have high heat resistance and strong magnetic force, making them excellent as aligning magnets to be used in magnetic field molding devices 100 and 100A.

[0049] In order to manufacture large plastic magnets 22, 22A to realize high-output motors 10, 10A, it is necessary to also increase the size of the oriented magnets 200, 200A. However, there is a limit to the size of the base material for manufacturing the oriented magnets 200, 200A that is generally available.

[0050] Therefore, the aligning magnets 200, 200A of the present disclosure are formed by combining multiple members. Here, an example is described in which the aligning magnets 200, 200A are each formed by combining two members, but the aligning magnets 200, 200A may also be formed by combining three or more members.

[0051] Fig. 5A is a schematic perspective view of an aligning magnet 200 used in the magnetic field molding apparatus 100. Fig. 5B is a plan view of the aligning magnet 200 of Fig. 5A disassembled into two members 210 and 220, viewed along direction Z of Fig. 5A (from above in this embodiment). Note that the aligning magnet 200 depicted in Figs. 5A and 5B is formed in a trapezoidal shape when viewed from above, but the shape of the aligning magnet 200 is merely an example, and it may be formed in any appropriate shape as needed.

[0052] As shown in FIG. 5A, the aligning magnet 200 is formed by combining a first member 210 and a second member 220. The first member 210 and the second member 220 are combined so that a first surface 212 of the first member 210 and a second surface 222 of the second member 220 face each other and are in contact with each other (see FIG. 5B). The first member 210 has a protrusion 214 that protrudes from the first surface 212 toward the second member 220. The second member 220 has a recess 224 that is recessed from the second surface 222 in a direction away from the first member 210 and into which the protrusion 214 fits. The protrusion 214 is formed over the entire first surface 212 in direction Z. The recess 224 is formed over the entire second surface 222 in direction Z.

[0053] The aligning magnet 200 is magnetized after the first member 210 and the second member 220 are combined together so that the convex portion 214 of the first member 210 fits into the concave portion 224 of the second member 220. The orientation direction of the magnetized aligning magnet 200 is a direction perpendicular to the first surface 212 and the second surface 222 (direction A in FIG. 5A).

[0054] When magnetized in this manner, the magnetic pole of the first surface 212 of the first member 210 and the magnetic pole of the second surface 222 of the second member 220 become opposite magnetic poles. Note that in Fig. 5B, the magnetic pole of the first surface 212 is depicted as an S pole and the magnetic pole of the second surface 222 as an N pole, but this is not limited to this, and the magnetic pole of the first surface 212 may be an N pole and the magnetic pole of the second surface 222 may be an S pole.

[0055] When the magnetic poles of the first surface 212 of the first member 210 and the second surface 222 of the second member 220 are opposite to each other, after magnetization, the magnetic force makes it difficult for the first member 210 and the second member 220 to become separated from each other in direction A.

[0056] However, if the convex portion 214 and the concave portion 224 are not present, when a force acts on the first member 210 and the second member 220 in the opposite direction in a direction perpendicular to the direction A (for example, the direction B shown in FIG. 5B), the first member 210 and the second member 220 may become disengaged.

[0057] In contrast, due to the presence of the convex portion 214 and the concave portion 224, the movement of the convex portion 214 in direction B is restricted by the concave portion 224, thereby preventing the first member 210 and the second member 220 from becoming misaligned in direction B.

[0058] Fig. 6A is a schematic perspective view of an oriented magnet 200A used in a magnetic field molding apparatus 100A. Fig. 6B is a plan view of the oriented magnet 200A of Fig. 6A disassembled into two members 210A and 220A, viewed along direction Z. Note that the oriented magnet 200A depicted in Figs. 6A and 6B is formed in a trapezoidal shape when viewed from above, but the shape of the oriented magnet 200A is merely an example, and the oriented magnet 200A may be formed in any appropriate shape as needed.

[0059] As shown in FIG. 6A, the aligning magnet 200A is formed by combining a first member 210A and a second member 220A. The first member 210A and the second member 220A are combined so that a first surface 212A of the first member 210A and a second surface 222A of the second member 220A face each other and contact each other (see FIG. 6B). The first member 210A has a protrusion 214A that protrudes from the first surface 212A toward the second member 220A. The second member 220A has a recess 224A that is recessed from the second surface 222A in a direction away from the first member 210A and into which the protrusion 214A fits. The protrusion 214A is formed over the entire first surface 212A in the Z direction. The recess 224A is formed over the entire second surface 222A in the Z direction.

[0060] The recess 224A has a restricting portion 228 that restricts movement of the protrusion 214A in a direction (direction A) perpendicular to the second surface 222A. This will be described in detail.

[0061] In aligning magnet 200A, protrusion 214A extends in direction A perpendicular to first surface 212A from first end 216A, which is a connection portion with first surface 212A, toward second member 220A to second end 216B. When protrusion 214A is viewed from direction Z (first direction) parallel to first surface 212A and second surface 222A, protrusion 214A has at second end 216B a first portion (here, second end 216B) whose width in direction B (second direction) is wider than the width of first end 216A in direction B (second direction) parallel to first surface 212A and orthogonal to direction Z (first direction).

[0062] The recess 224A that fits into the protrusion 214A has a shape that corresponds to the shape of the protrusion 214A (the shape of the protrusion 214A when viewed from the Z direction and the shape of the recess 224A when viewed from the Z direction are substantially the same).

[0063] Specifically, recess 224A extends in direction A perpendicular to second surface 222A (first surface 212A) from a first end 226A, which is a boundary with second surface 222A, to a second end 226B in a direction away from first surface 212A. When recess 224A is viewed from direction Z parallel to first surface 212A and second surface 222A, recess 224A has a portion (here, second end 226B) at second end 226B whose width in direction B is wider than the width of first end 226A in direction B parallel to second surface 222A and orthogonal to direction Z (first direction).

[0064] In aligning magnet 200A, when convex portion 214A is combined with concave portion 224A (when convex portion 214A is fitted into concave portion 224A along the Z direction), the width of second end 216B of convex portion 214A in direction B (second direction) is wider than the width of first end 226A of concave portion 224A in direction B, and therefore movement of convex portion 214A in direction A perpendicular to second surface 222A is restricted by first end 226A of concave portion 224A. In other words, first end 226A of concave portion 224A is an example of restriction portion 228.

[0065] The aligning magnet 200A is magnetized after the first member 210A and the second member 220A are combined together so that the convex portion 214A of the first member 210A fits into the concave portion 224A of the second member 220A. The orientation direction of the aligning magnet 200A after magnetization is direction Z shown in Fig. 6A, which is a direction parallel to the first surface 212A and the second surface 222A.

[0066] When magnetized in this manner, the magnetic pole of the first surface 212A of the first member 210A and the magnetic pole of the second surface 222A of the second member 220A become the same magnetic pole. Note that in Fig. 6A, the upper parts of the first member 210A and the second member 220A are depicted as south poles and the lower parts of the first member 210A and the second member 220A are depicted as north poles, but this is not limited thereto, and the upper parts of the first member 210A and the second member 220A may be north poles and the lower parts of the first member 210A and the second member 220A may be south poles.

[0067] When the magnetic poles of the first surface 212A of the first member 210A and the second surface 222A of the second member 220A are the same magnetic pole, if the convex portion 214A and the concave portion 224A are not provided, the first member 210A and the second member 220A will be separated from each other due to a repulsive force after magnetization.

[0068] In contrast, since the oriented magnet 200A has a convex portion 214A and a concave portion 224A (by providing a regulating portion 228 in the concave portion 224A), movement of the convex portion 214A in the direction A perpendicular to the second surface 222A is regulated by the regulating portion 228 of the concave portion 224A, and the first member 210A and the second member 220A are regulated from being separated from each other due to the repulsive force.

[0069] Furthermore, in the oriented magnet 200A, similar to the oriented magnet 200, the movement of the convex portion 214A in direction B (see FIG. 6B) is restricted by the concave portion 224A, thereby preventing the first member 210A and the second member 220A from becoming misaligned in direction B.

[0070] In addition to the method disclosed herein, another possible method for forming an oriented magnet by combining multiple components is to bond two components together with an adhesive. However, this method makes it difficult to control the thickness of the adhesive, which can lead to variations in size between the components. If such variations in size occur, it is necessary to increase the clearance between the plastic magnet molding mold 110, 110A and the oriented magnet. In this case, variations in the magnetic field orientation of the plastic magnet manufactured by the magnetic field molding device 100, 100A may occur, and in motors using these plastic magnets, the cogging torque and torque ripple may increase, resulting in increased noise and vibration.

[0071] One method of manufacturing oriented magnets is to machine the oriented magnets after bonding them with an adhesive to make them uniform in size. For example, wire electric discharge machining is suitable for machining oriented magnets because it allows for high-precision machining, reduces chipping without applying load, and allows for continuous machining of oriented magnet shapes, whether linear or curved, without the need for tool changes. However, when forming oriented magnets by joining two components with an adhesive, wire electric discharge machining cannot be used because adhesives do not conduct electricity.

[0072] Furthermore, cutting processes using a machining center or processes using a polishing machine or profile grinding machine (grinding processes) are not suitable for processing oriented magnets for the following reasons.

[0073] First, when using a machining center, cutting load is applied to the oriented magnet, which may cause chipping or, in the worst case, shatter the base material.

[0074] Next, when using a polishing machine or profile grinder, chipping occurs at the corners due to the grinding load. Also, because grinding can only remove a small amount of material at a time, it takes a long time to process if the size of the base material to be cut is large compared to the size of the oriented magnet. Furthermore, when the size of the base material to be cut is large compared to the size of the oriented magnet, it is possible to create the rough shape using cutting processing with a machining center and then finish it off with grinding, but using a machining center could result in the base material being destroyed as mentioned above.

[0075] In this way, when an oriented magnet is manufactured by bonding two components together with an adhesive, various problems arise, whereas the oriented magnets 200 and 200A of the present disclosure can realize large oriented magnets without causing such problems.

[0076] (3) Features (3-1) The oriented magnets 200, 200A are formed by combining first members 210, 210A and second members 220, 220A. The first members 210, 210A and second members 220, 220A are combined so that first surfaces 212, 212A of the first members 210, 210A and second surfaces 222, 222A of the second members 220, 220A face and contact each other. The first members 210, 210A have protrusions 214, 214A that protrude from the first surfaces 212, 212A toward the second members 220, 220A. The second members 220, 220A are recessed from the second surfaces 222, 222A in a direction away from the first members 210, 210A, and have recesses 224, 224A into which the protrusions 214, 214A fit.

[0077] In the oriented magnets 200, 200A, convex portions 214, 214A are provided on the first members 210, 210A, and concave portions 224, 224A are provided on the second members 220, 220A, thereby suppressing positional misalignment between the first members 210, 210A and the second members 220, 220A in the direction along the first surfaces 212, 212A of the first members 210, 210A and the second surfaces 222, 222A of the second members 220, 220A (direction B in Figures 5B and 6B).

[0078] Therefore, in the oriented magnets 200 and 200A, the oriented magnets can be manufactured with good dimensional accuracy by combining a plurality of members without using adhesive.

[0079] (3-2) The orientation direction of the aligning magnet 200 is a direction A perpendicular to the first surface 212 and the second surface 222. The magnetic pole of the first surface 212 and the magnetic pole of the second surface 222 are opposite to each other.

[0080] In aligning magnet 200, the magnetic poles of first surface 212 and second surface 222 are opposite to each other, so an attractive force acts between first surface 212 and second surface 222. Therefore, in aligning magnet 200, misalignment of combined first member 210 and second member 220 is easily suppressed.

[0081] (3-3) In the aligning magnet 200A, the recess 224A has a restricting portion 228 that restricts movement of the protrusion 214A in the direction A perpendicular to the second surface 222A.

[0082] In the aligning magnet 200A, the recessed portion 224A restricts the movement of the protruding portion 214A, so that the combined first member 210A and second member 220A are unlikely to come apart.

[0083] Specifically, in aligning magnet 200A, protrusion 214A extends in direction A perpendicular to first surface 212A from first end 216A, which is a connection portion with first surface 212A, to second end 216B. When protrusion 214A is viewed from direction Z (first direction) parallel to first surface 212A and second surface 212A, protrusion 214A has a first portion at second end 216B. The width of first portion of protrusion 214A in direction B (second direction), which is parallel to first surface 212A and perpendicular to direction Z, is wider in direction B than the width of first end 216A in direction B.

[0084] In aligning magnet 200A, when protrusion 214A is viewed along the orientation direction, protrusion 214A has a first portion at second end 216B that is wider than first end 216A, and recess 224A into which protrusion 214A fits has a shape that corresponds to protrusion 214A. Therefore, in aligning magnet 200A, first end 226A of recess 224A functions as restriction portion 228, and prevents first member 210A and second member 220A from moving away from each other.

[0085] In particular, in the aligning magnet 200A described in the above embodiment, direction Z is the alignment direction of aligning magnet 200A. Therefore, the magnetic poles of first surface 212A and second surface 222A corresponding to first surface 212A are the same, and a repulsive force acts between first surface 212A and second surface 222A. Therefore, without a means for restricting movement, first surface 212A and second surface 222A will move in directions away from each other.

[0086] However, even if a repulsive force acts between the first surface 212A and the second surface 222A, the convex portion 214A and the concave portion 224A prevent the first member 210A and the second member 220A from moving away from each other.

[0087] In the above embodiment, the oriented magnet 200A is described as a magnet whose orientation direction is direction Z, but the structure of the oriented magnet 200A can also be used when the orientation direction is direction A perpendicular to the first surface 212A and the second surface 222A.

[0088] (3-4) The orienting magnets 200 and 200A are made of samarium cobalt.

[0089] Samarium-cobalt magnets have excellent properties such as strong magnetic force and can be used at relatively high temperatures.

[0090] On the other hand, grinding is not suitable for samarium-cobalt oriented magnets, and when forming an oriented magnet by joining two members with an adhesive, as in Patent Document 1 (JP 2001-267164 A), wire discharge cutting cannot be used because the adhesive does not conduct electricity. Therefore, when forming an oriented magnet made of samarium-cobalt by joining two members with an adhesive, it is difficult to perform the necessary machining on the oriented magnet.

[0091] In contrast, in the aligning magnets 200, 200A of the present disclosure, no adhesive is used when combining the two members, so even with the aligning magnets 200, 200A made of samarium-cobalt, the occurrence of such problems can be suppressed.

[0092] (4) Variations The following are modifications of the above embodiment. The modifications may be combined as appropriate as long as they are not inconsistent with each other.

[0093] (4-1) Variation A In the above embodiment, the case where the oriented magnet 200A has a convex portion 214A (and a correspondingly shaped concave portion 224A) that is trapezoidal when viewed from direction Z has been described, but the shape of the convex portion 214A (and the corresponding shape of the concave portion 224A) may be selected as appropriate.

[0094] For example, in the oriented magnet 200B shown in FIGS. 7A and 7B, the convex portion 214B has an arc shape (an arc shape with an angle greater than 180°) when viewed along the Z direction.

[0095] The protrusion 214B extends in a direction A (see FIG. 7A) perpendicular to the first surface 212A from a first end 216A, which is a connection portion with the first surface 212A, toward the second member 220A to a second end 216B. When the protrusion 214B is viewed from a direction Z (first direction) parallel to the first surface 212A and the second surface 222A, the protrusion 214B has a first portion 218 between the first end 216A and the second end 216B, which has a width in direction B (second direction) parallel to the first surface 212A and perpendicular to direction Z, greater than the width of the first end 216A in direction B.

[0096] The recess 224B that fits into the protrusion 214B has a shape corresponding to the shape of the protrusion 214B (the shape of the protrusion 214B when viewed from the Z direction and the shape of the recess 224B when viewed from the Z direction are substantially the same).

[0097] The recess 224B extends in a direction A perpendicular to the second surface 222A (first surface 212A) from a first end 226A, which is a boundary with the second surface 222A, to a second end 226B in a direction away from the first surface 212A. When the recess 224B is viewed from a direction Z (first direction) parallel to the first surface 212A and the second surface 222A, the recess 224B has a portion between the first end 226A and the second end 226B whose width in the direction B (second direction) is wider than the width of the first end 226A in the direction B parallel to the second surface 222A and perpendicular to the direction Z.

[0098] Here, when the protrusion 214B is fitted into the recess 224B (when the protrusion 214B is fitted into the recess 224B along the Z direction), the width of the first portion 218 of the protrusion 214B in direction B is narrower than the width of the first end 226A of the recess 224B in direction B, and therefore movement of the protrusion 214B in direction A perpendicular to the second surface 222A is restricted by the first end 226A of the recess 224B. In other words, the first end 226A of the recess 224B is an example of a restricting portion 228.

[0099] Note that oriented magnet 200B of this modified example may be a magnet oriented in direction Z, or may be a magnet oriented in direction A perpendicular to first surface 212A and second surface 222A.

[0100] (4-2) Variation B In the above embodiment, the first member 210 of the aligning magnet 200 has a single protrusion 214, and the second member 220 of the aligning magnet 200 has a single recess 224, but this is not limiting.

[0101] As shown in FIG. 8, the aligning magnet 200 may have a first member 210 having a plurality of protrusions 214, and a second member 220 having recesses 224 in a number corresponding to the number of protrusions 214.

[0102] Although not shown in the drawings, the aligning magnet 200A may also have a first member 210A having a plurality of protrusions 214A, and a second member 220A having recesses 224A in a number corresponding to the number of protrusions 214A.

[0103] (4-3) Variation C In the above embodiment, the convex portion 214 of the first member 210 of the aligning magnet 200 is provided over the entire first surface 212 in direction Z, but the shape of the convex portion 214 is not limited to this shape.

[0104] For example, as shown in Fig. 9, a first member 210 of an oriented magnet 200 may have a convex portion 214 provided only in the center in direction Z. The left-hand view of Fig. 9 is a view of the first member 210 viewed along direction B in Fig. 5A etc., and the right-hand view of Fig. 9 is a view of the first member 210 viewed (along direction A) in a state facing the first surface 212. Then, a concave portion 224 may be provided in the second member 220 of the oriented magnet 200 at a position facing the convex portion 214 (the concave portion 224 is not shown).

[0105] With this configuration, in addition to the misalignment of the first member 210 and the second member 220 along the direction B, the misalignment of the first member 210 and the second member 220 along the direction Z can also be suppressed.

[0106] (4-4) Variation D For example, as shown in Fig. 10, the first member 210A of the oriented magnet 200A may be provided with an L-shaped protrusion 214A that extends in direction A toward the second member 220A and then extends downward along direction Z. The left-hand view of Fig. 10 is a view of the first member 210A viewed along direction B in Fig. 6A etc., and the right-hand view of Fig. 10 is a view of the first member 210A viewed (along direction A) in a state facing the first surface 212A. The second member 220A of the oriented magnet 200A may be provided with a recess 224A of an opposing shape (in which the L-shaped protrusion 214A fits) at a position facing the protrusion 214A (recess 224A is not shown).

[0107] (4-5) Variation E In the above embodiment, the convex portion 214 of the first member 210 of the oriented magnet 200 extends along the direction Z, and the concave portion 224 of the second member 220 of the oriented magnet 200 extends along the direction Z. However, the present invention is not limited to this embodiment. 11, the convex portion 214 of the first member 210 of the aligning magnet 200 may extend along direction B, and the concave portion 224 of the second member 220 of the aligning magnet 200 may also extend along direction B. In this case, the first member 210 and the second member 220 are prevented from being misaligned along direction Z.

[0108] The same applies to the orienting magnet 200A.

[0109] (4-6) Variation F In the above embodiment, the aligning magnets 200, 200A have a trapezoidal shape when viewed along the direction Z, and the convex portions 214, 214A are provided on the members 210, 210A on the shorter side, and the concave portions 224, 224A are provided on the members 220, 220A on the longer side. However, this is not limited to this, and the concave portions may be provided on the members 210, 210A, and the convex portions may be provided on the members 220, 220A.

[0110] <Additional Note> Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure as defined in the claims. [Explanation of symbols]

[0111] 100,100A magnetic field molding device 110,110A mold 200,200A oriented magnet 210, 210A First member 212,212A 1st page 214,214A convex part 216A 1st end 216B Second end (first part) 218 Part 1 220, 220A Second member 222,222A 2nd side 224,224A recess 228 Regulatory Department 230,230A Corner [Prior art documents] [Patent documents]

[0112] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-267164

Claims

1. An oriented magnet (200, 200A) formed by combining a first member (210, 210A) and a second member (220, 220A), The first member and the second member are combined so that a first surface (212, 212A) of the first member and a second surface (222, 222A) of the second member face each other and contact each other, The first member has a protrusion (214, 214A) protruding from the first surface toward the second member, The second member has a recess (224, 224A) recessed from the second surface in a direction away from the first member and into which the protrusion fits. Oriented magnet.

2. The orientation direction of the orientation magnet is perpendicular to the first surface (210) and the second surface (220), The magnetic poles on the first surface and the magnetic poles on the second surface are opposite to each other. The aligning magnet (200) of claim 1.

3. The recess (224A) has a restricting portion (228) that restricts movement of the protrusion (214A) in a direction perpendicular to the second surface (212A). The oriented magnet (220A) of claim 1.

4. The convex portion (214A) extends in a direction perpendicular to the first surface (212A) from a first end (216A) that is a connection portion with the first surface to a second end (216B), When the convex portion is viewed from a first direction (Z) parallel to the first surface and the second surface (222A), the convex portion has a first portion (216B, 218) at the second end or between the first end and the second end, the first portion having a width in the second direction that is parallel to the first surface and perpendicular to the first direction, the first portion being wider than the width of the first end in the second direction. The oriented magnet according to claim 1 .

5. The first direction is the orientation direction of the orientation magnet. The oriented magnet according to claim 4 .

6. Made from samarium cobalt The oriented magnet according to claim 1 .

7. a mold (110, 110A) into which molten plastic magnet raw material is supplied; The aligning magnet (200, 200A) according to any one of claims 1 to 5, which is placed in the mold; A magnetic field molding device (100, 100A) for plastic magnets.

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