Method for manufacturing a magnet and method for manufacturing a rotor

Abstract

The present invention provides a method for manufacturing a magnet and a method for manufacturing a rotor. The intermediate body includes a sheet and a plurality of magnet bodies. The sheet has a first sheet surface and a second sheet surface on the side opposite to the first sheet surface. The plurality of magnet bodies are located on the first sheet surface. The first mold is made of an elastic material having an elastic modulus smaller than that of the magnet body. The intermediate body is disposed between the first mold and the second mold such that the second sheet surface of the sheet faces the first mold. The first mold and the second mold sandwich the intermediate body. Accordingly, the sheet is cut at positions between the adjacent magnet bodies arranged adjacent to each other.

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a magnet and a method for manufacturing a rotor. Background Art

[0002] The rotor of the motor disclosed in Japanese Patent Publication No. 5967297 has a rotor core and a plurality of magnets. A plurality of slots are formed in the rotor core. The plurality of magnets are located in the respective slots. Summary of the Invention

[0003] According to one aspect of the present disclosure, there is provided a method for manufacturing a magnet. The manufacturing method includes a step of producing an intermediate body. The intermediate body includes a sheet and a plurality of magnet bodies. The sheet has a first sheet surface and a second sheet surface on the side opposite to the first sheet surface. The plurality of magnet bodies are located on the first sheet surface. The manufacturing method includes a step of disposing the intermediate body between a first mold and a second mold. The first mold is made of an elastic material having an elastic modulus smaller than that of the magnet body. The second mold faces the first mold. The intermediate body is disposed between the first mold and the second mold such that the second sheet surface of the sheet faces the first mold. The manufacturing method includes a step of sandwiching the intermediate body between the first mold and the second mold and cutting the sheet at a position between adjacent magnet bodies arranged adjacent to each other.

[0004] In the above configuration, when cutting the sheet, the first mold elastically deforms in a direction extending laterally with respect to the magnet body. The first mold also elastically deforms so as to enter between adjacent magnet bodies. As a result, a force in a direction away from each other acts on adjacent magnet bodies. In addition, the force from the elastically deformed first mold easily acts intensively on the edge portions of each magnet body. As a result, the sheet is cut at a position between adjacent magnet bodies. The cutting of the sheet occurs at various positions of adjacent magnet bodies. Therefore, the sheet can be cut efficiently.

[0005] In addition, as a magnet for a rotor, a magnet having a magnet body and a sheet piece as a sheet-like coating film adhered to the surface of the magnet body is sometimes used.

[0006] However, it takes time to cut one by one the sheet as a material for the coating film in accordance with the shape of each magnet body. Therefore, a technique for efficiently cutting the sheet for covering the surface of the magnet body is desired. The above configuration contributes to such a technique.

[0007] In the method for manufacturing a magnet, the magnet body has a planar first magnet surface and a planar second magnet surface adjacent to the first magnet surface. In the process of manufacturing the intermediate body, the plurality of magnet bodies may be arranged on the first sheet surface of the sheet in such a manner that the first magnet surface contacts the sheet.

[0008] According to the above configuration, when the first mold is pressed against the intermediate body, it is easy to apply a force from the first mold to the boundary between the first magnet surface and the second magnet surface in the magnet body. Therefore, it is easy to cut the sheet at the above boundary.

[0009] In the method for manufacturing a magnet, the surface of the first mold facing the sheet has a planar flat surface and a protruding surface protruding from the flat surface. Alternatively, in the process of arranging the intermediate body between the first mold and the second mold, the intermediate body may be arranged such that the boundary between the first magnet surface and the second magnet surface in the magnet body and the protruding surface sandwich the sheet therebetween and face each other.

[0010] According to the above configuration, when the first mold is pressed against the intermediate body, the force easily acts on the sheet from the protruding surface of the first mold. Specifically, a very strong force is applied to the portion of the sheet clamped by the protruding surface of the first mold and the boundary between the first magnet surface and the second magnet surface in the magnet body. Therefore, the sheet can be more reliably cut at this portion of the sheet clamped by the protruding surface and the boundary of the magnet body.

[0011] In the method for manufacturing a magnet, the sheet contains thermoplastic resin fibers and inorganic fibers. In the process of manufacturing the intermediate body, the sheet may be heated to a temperature above the glass transition temperature of the thermoplastic resin fibers while being pressed, so that the sheet is thermally bonded to the plurality of magnet bodies in a state where the inorganic fibers are elastically compressed.

[0012] A sheet containing thermoplastic resin fibers and inorganic fibers is thermally bonded to the magnet body. After that, if the sheet and the magnet body are heated again, the thermoplastic resin fibers in the sheet are softened again. Then, due to the action of the restoration of the elastically compressed inorganic fibers, the sheet expands. In order to utilize the characteristic of the expansion of the sheet, the magnet formed by thermally bonding the sheet to the magnet body is arranged in the slot of the rotor core, and the sheet is cut to generate the thin sheet. By heating the magnet in the slot to expand the thin sheet, the magnet can be fixed to the rotor core.

[0013] In the above-described form, in the process of manufacturing the intermediate, the sheet is thermally bonded to a plurality of magnet bodies. Therefore, in the process of cutting the sheet, a plurality of magnets in a state where the thin sheet is thermally bonded to the magnet body can be manufactured. The above-described plurality of magnets are arranged in the slots of the rotor core. By heating the magnets in the slots, the magnets can be fixed to the rotor core. Thus, according to the above-described form, a rotor can be manufactured very efficiently.

[0014] According to another aspect of the present disclosure, a method for manufacturing a rotor is provided. The manufacturing method includes a process of manufacturing an intermediate. The intermediate has a sheet and a plurality of magnet bodies. The sheet has a first sheet surface and a second sheet surface on the side opposite to the first sheet surface. The sheet includes thermoplastic resin fibers and inorganic fibers. While heating the sheet to a temperature above the glass transition temperature of the thermoplastic resin fibers in a state where the plurality of magnet bodies are located on the first sheet surface of the sheet, the sheet is pressed. Therefore, the sheet is thermally bonded to the plurality of magnet bodies in a state where the inorganic fibers are elastically compressed. The manufacturing method includes a process of arranging the intermediate between a first mold and a second mold. The first mold is made of an elastic material having an elastic modulus smaller than that of the magnet body. The second mold faces the first mold. The intermediate is arranged between the first mold and the second mold such that the second sheet surface of the sheet faces the first mold. In the manufacturing method, in order to manufacture a magnet, a process of cutting the sheet at a position between adjacent magnet bodies by sandwiching the intermediate with the first mold and the second mold is included. The magnet has a magnet body and a thin sheet generated by cutting the sheet and covering the magnet body. The manufacturing method includes a process of heating the magnet to a temperature above the glass transition temperature in a state where the magnet is arranged in a slot formed in a rotor core. By heating the magnet to a temperature above the glass transition temperature, the inorganic fibers elastically recover. Therefore, the magnet is fixed to the rotor core.

[0015] If a sheet containing thermoplastic resin fibers and inorganic fibers is thermocompression-bonded to a magnet body and then heated again, the thermoplastic resin fibers in the sheet are softened again, and the sheet expands due to the action of the inorganic fibers restored after elastic compression. In the above form, by utilizing this property, the thin sheet thermocompression-bonded to the magnet body expands in the slots of the rotor core, thereby fixing the magnet to the rotor core. On the basis of fixing the magnet to the rotor core in this way, in the above form, an intermediate body in which the sheet is thermocompression-bonded to a plurality of magnet bodies is prepared in advance. Then, by sandwiching the intermediate body with a first mold and a second mold, the intermediate body is cut between adjacent magnet bodies. When the first mold is pressed against the intermediate body by sandwiching the intermediate body with the first mold and the second mold, the first mold elastically deforms in a manner extending in the lateral direction and elastically deforms in a manner of entering between adjacent magnet bodies. As a result, a force in the direction of moving away from each other acts on adjacent magnet bodies. In addition, the force from the elastically deformed first mold easily acts concentratedly on the edge portions of each magnet body. As a result, the sheet is cut between adjacent magnet bodies. The cutting of the sheet occurs at various positions of the adjacent magnet bodies in the cutting process. Therefore, the sheet can be cut efficiently.

[0016] "At least one of A and B" described in this specification should be understood to mean "only A", "only B", or "both A and B". Description of the Drawings

[0017] Figure 1 It is a cross-sectional view of an electric motor including a rotor manufactured by the manufacturing method of the present disclosure.

[0018] Figure 2 is Figure 1 a top view of the rotor shown.

[0019] Figure 3 is Figure 1 and Figure 2 a perspective view of the magnet shown.

[0020] Figure 4 is a diagram showing Figure 2 a flowchart of the manufacturing process of the rotor shown.

[0021] Figure 5 is Figure 4 an explanatory view of the intermediate body manufacturing process shown.

[0022] Figure 6 is an explanation of Figure 5 an explanatory view of the intermediate body manufacturing apparatus for the intermediate body manufacturing process shown.

[0023] Figure 7 is Figure 4 an explanatory view of the arrangement process shown.

[0024] Figure 8 is Figure 4 an explanatory diagram of the cutting process shown in

[0025] Figure 9 is Figure 4 an explanatory diagram of the insertion process shown in

[0026] Figure 10 is Figure 4 an explanatory diagram of the fixing process shown in

[0027] Figure 11 is related to Figure 8 a diagram showing a modification example of the cutting device

[0028] Figure 12 is related to Figure 8 a diagram showing a modification example of the cutting device

[0029] Figure 13 is related to Figure 6 a diagram showing a modification example of the intermediate manufacturing process Detailed implementation mode

[0030] Hereinafter, with reference to Figures 1 to 10 , an embodiment of a method for manufacturing a magnet and a method for manufacturing a rotor will be described.

[0031] <Overall structure of the motor>

[0032] First, the schematic structure of the motor will be described.

[0033] As Figure 1 shown, the motor 50 has a stator 70, a rotor 60, and a shaft 55.

[0034] The stator 70 is cylindrical as a whole. The stator 70 has a stator core 72 and a coil 76. Moreover, the stator core 72 has a main body of the stator core 72 (hereinafter, referred to as the stator core main body) 72A and a plurality of teeth 72B. The stator core main body 72A is cylindrical. The plurality of teeth 72B project from the inner peripheral surface of the stator core main body 72A toward the central axis J of the stator core main body 72A. The plurality of teeth 72B are arranged at equal intervals in the circumferential direction. In addition, in Figure 1 , a double-dot chain line is marked at the boundary between the stator core main body 72A and the teeth 72B.

[0035] The coil 76 is wound around each tooth 72B. The coil 76 reaches a position outside the ends of the stator core main body 72A in the direction along the central axis J of the stator core main body 72A. That is, the coil 76 protrudes from the stator core 72 in the direction along the central axis J of the stator core main body 72A. In addition, in this specification, the same reference numeral J is assigned to the central axes of members having a central axis coaxial with the central axis J of the stator core main body 72A. For example, the central axis of the rotor 60 is also assigned the reference numeral J.

[0036] The rotor 60 is cylindrical. The rotor 60 is located inside the stator core main body 72A. The central axis J of the rotor 60 coincides with the central axis J of the stator core main body 72A. There is a gap between the outer peripheral surface of the rotor 60 and the radially inner ends, i.e., the protruding ends of the respective teeth 72B in the stator 70. In Figure 1 the illustration of this gap is omitted. In addition, the details of the rotor 60 will be described later. The rotor 60 can rotate relative to the stator 70.

[0037] The shaft 55 is cylindrical. The shaft 55 passes through the hole at the center of the rotor 60. The central axis J of the shaft 55 coincides with the central axis J of the rotor 60. The shaft 55 rotates integrally with the rotor 60.

[0038] <Structure of the rotor>

[0039] The rotor 60 will be described in detail. The rotor 60 has a rotor core 62 and a plurality of magnets 80. The rotor core 62 is cylindrical. Although not shown in the illustration, the rotor core 62 is formed by laminating a plurality of electromagnetic steel sheets processed into a circular ring shape in the direction along their central axis J.

[0040] A plurality of slots 64 are formed in the rotor core 62. The plurality of slots 64 are through holes that penetrate the rotor core 62 in the direction along the central axis J of the rotor core 62. As Figure 2 shown, the plurality of slots 64 are located at positions near the outer peripheral surface of the rotor core 62, i.e., near the outer peripheral side. The plurality of slots 64 are arranged in the circumferential direction of the rotor core 62.

[0041] As Figure 2 shown, when viewed from above in the direction along the central axis J of the rotor core 62, the slot 64 is substantially rectangular in shape. Taking two adjacent slots 64 in the circumferential direction of the rotor core 62 as a pair, a total of eight pairs of slots 64 are provided. When viewed from above in the direction along the central axis J of the rotor core 62, the two paired slots 64 are arranged in a V-shaped configuration. Specifically, it can be said that the closer the two paired slots 64 are to the inner peripheral side of the rotor core 62, the closer the distance between them.

[0042] A plurality of magnets 80 are respectively located within the respective slots 64. That is, there is one magnet 80 in each slot 64. Each magnet 80 has a main body of the magnet 80 (hereinafter, referred to as the magnet main body) 82 and two thin sheets 85.

[0043] The magnet main body 82 is composed of a permanent magnet. In the present embodiment, the magnet main body 82 is a neodymium magnet made of raw materials such as iron, neodymium, and boron. As Figure 3 shown, the magnet main body 82 is in the shape of a rectangular plate. Specifically, the magnet main body 82 has two first magnetic surfaces 82A, two second magnetic surfaces 82B, and two third magnetic surfaces 82C. The first magnetic surface 82A is the surface with the largest area among the outer surfaces of the magnet main body 82. The first magnetic surface 82A is rectangular in shape. The first magnetic surface 82A is not bent and is planar. The two first magnetic surfaces 82A are in a parallel positional relationship with each other. The second magnetic surfaces 82B respectively connect the long sides of the two first magnetic surfaces 82A to each other. That is, the second magnetic surface 82B is adjacent to the first magnetic surface 82A. The second magnetic surface 82B is not bent and is planar. The first magnetic surface 82A and the second magnetic surface 82B are substantially orthogonal. That is, the boundary 82S between the first magnetic surface 82A and the second magnetic surface 82B has sharp corners. The third magnetic surfaces 82C respectively connect the short sides of the two first magnetic surfaces 82A to each other. That is, the third magnetic surface 82C is adjacent to the first magnetic surface 82A. The third magnetic surface 82C is not bent and is planar. The first magnetic surface 82A and the third magnetic surface 82C are substantially orthogonal. That is, the boundary 82T between the first magnetic surface 82A and the third magnetic surface 82C has sharp corners.

[0044] The thin sheets 85 are non-woven fabrics made of polyetherimide fibers as thermoplastic resin fibers and glass fibers as inorganic fibers. The two thin sheets 85 respectively cover the two first magnetic surfaces 82A in the magnet main body 82. The two thin sheets 85 form an insulating layer. In addition, in each of the figures in the drawings, the thickness of the thin sheet 85 is exaggerated and enlarged.

[0045] The shape and size of the magnet 80 are substantially the same as the shape and size of the slot 64. As Figure 2 shown, when viewed from above in the direction along the central axis J of the rotor core 62, the direction along the short side of the rectangular slot 64 is referred to as the width direction of the slot 64. As Figure 1 shown, in the state where the magnet 80 is fixed to the slot 64, the two thin sheets 85 in the magnet 80 are in contact with the inner surfaces on both sides in the width direction in the slot 64. In addition, in the direction along the central axis J of the rotor core 62, the positions of both ends of the magnet 80 coincide with the positions of both ends of the slot 64. In addition, as Figure 2As shown, when viewed from above in the direction along the central axis J of the rotor core 62, there is a gap between the magnet 80 and the inner surfaces on both sides in the longitudinal direction of the slot 64. The inner surfaces on both sides in the longitudinal direction of the slot 64 are depicted as arc-shaped in Figure 2 .

[0046] As Figure 2 shown, a pair of magnets 80 disposed in a pair of two slots 64 constitute each magnetic pole of the motor 50. That is, the radially outer surfaces of the pair of magnets 80 disposed in a pair of two slots 64 of the rotor 60 are magnetized to the same polarity with each other. And this pair of magnets 80 constitutes a magnetic pole of N pole or S pole. In addition, the polarities are opposite between a pair of magnets 80 and a pair of magnets 80 adjacent thereto. As a result, in the rotor 60, N poles and S poles are alternately arranged in the circumferential direction.

[0047] <Intermediate manufacturing device>

[0048] The intermediate manufacturing device 200 used when manufacturing the above-mentioned magnet 80 will be described. In addition, hereinafter, the description will be made based on the up and down in the drawings, but the up and down in the drawings do not need to be the same as the actual up and down.

[0049] As Figure 6 shown, the intermediate manufacturing device 200 is a stamping die device. The intermediate manufacturing device 200 has a first pressing die 201 and a second pressing die 202. The first pressing die 201 has a substantially rectangular parallelepiped shape. The first pressing die 201 is made of copper. The reason for using copper as the material of the first pressing die 201 is that copper has a high thermal conductivity. The shape and material of the second pressing die 202 are the same as those of the first pressing die 201. The second pressing die 202 is located above the first pressing die 201. The upper surface of the first pressing die 201 faces the lower surface of the second pressing die 202. By driving with a servo motor, the second pressing die 202 approaches or separates from the first pressing die 201.

[0050] The first pressing die 201 has a first recess 201A. The first recess 201A is recessed downward on the upper surface of the first pressing die 201. The shape of the first recess 201A when viewed from above the first pressing die 201 is a rectangular shape. The dimensions of the long side and the short side of the first recess 201A when viewed from above the first pressing die 201 are larger than the dimensions of the long side and the short side of the sheet 86 prepared in the subsequent preparation process S10. The depth of the depression of the first recess 201A is less than half of the thickness of the magnet body 82. The second pressing die 202 has a second recess 202A similar to the first recess 201A of the first pressing die 201. The second recess 202A is recessed upward on the lower surface of the second pressing die 202.

[0051] The intermediate manufacturing device 200 includes two heaters H, two cooling water passages W, two temperature sensors T, and a load sensor 204. One of the two heaters H is located inside the first pressing die 201. Additionally, the other heater H is located inside the second pressing die 202. Each heater H can adjust the temperature of the first pressing die 201 and the second pressing die 202 respectively. One of the two cooling water passages W is a space partitioned inside the first pressing die 201. The other cooling water passage W is a space partitioned inside the second pressing die 202. Although not shown in the figure, there is a switching mechanism outside the first pressing die 201 and the second pressing die 202 that allows or prohibits the flow of cooling water to the two cooling water passages W. One of the two temperature sensors T detects the temperature of the first recess 201A of the first pressing die 201. The other temperature sensor T detects the temperature of the second recess 202A of the second pressing die 202. Each temperature sensor T is constituted by, for example, a thermocouple. The load sensor 204 detects the force applied to the object sandwiched between the first pressing die 201 and the second pressing die 202 when the second pressing die 202 approaches the first pressing die 201. The load sensor 204 is constituted by, for example, a force measuring sensor. Additionally, in Figure 6 for convenience, the load sensor 204 is shown on the side surface of the first pressing die 201.

[0052] <Cutting device>

[0053] The cutting device 300 used in manufacturing the magnet 80 will be described.

[0054] As Figure 7 shown, the cutting device 300 includes a first base member 301 and a second base member 302. The first base member 301 is substantially rectangular parallelepiped-shaped. The first base member 301 is made of metal. The shape and material of the second base member 302 are the same as those of the first base member 301. The second base member 302 is located above the first base member 301. By being driven by a servo motor, the second base member 302 approaches or moves away from the first base member 301.

[0055] The cutting device 300 includes a first die 303 and a second die 304. The first die 303 is substantially rectangular parallelepiped-shaped. The first die 303 is made of an elastic material. Specifically, the material of the first die 303 is a thermosetting elastomer, i.e., rubber. The elastic modulus of the first die 303 is smaller than the elastic modulus of the magnet body 82. The Shore hardness of the first die 303 is about 70 - 90 HS. The Shore hardness is an index indicating the hardness of an object. The larger the Shore hardness, the harder the object. The shape, material, elastic modulus, and Shore hardness of the second die 304 are the same as those of the first die 303.

[0056] The first mold 303 and the second mold 304 are located between the first base member 301 and the second base member 302. Specifically, the first mold 303 is located on the upper surface of the first base member 301. The first mold 303 is fixed to the upper surface of the first base member 301. The second mold 304 is located on the lower surface of the second base member 302. The second mold 304 is fixed to the lower surface of the second base member 302. The lower surface of the second mold 304 faces the upper surface of the first mold 303. The lower surface of the second mold 304 and the upper surface of the first mold 303 are both not bent but planar. The second mold 304 moves integrally with the second base member 302. That is, when the second base member 302 approaches or moves away from the first base member 301, the second mold 304 approaches or moves away from the first mold 303.

[0057] <Method for manufacturing a magnet and a rotor>

[0058] A method for manufacturing the magnet 80 and the rotor 60 will be described. As Figure 4 shown, the manufacturing method of the rotor 60 has respective steps such as a preparation step S10, an intermediate body manufacturing step S20, an arrangement step S30, a cutting step S40, an insertion step S50, and a fixing step S60. In addition, the magnet 80 is manufactured by the steps from the preparation step S10 to the cutting step S40 among these six steps. That is, the manufacturing method of the magnet 80 has respective steps from the preparation step S10 to the cutting step S40.

[0059] When manufacturing the rotor 60, first, the preparation step S10 is performed. In the preparation step S10, a rotor core 62, a magnet body 82, and a sheet 86 are prepared. Regarding the rotor core 62 and the magnet body 82, a rotor core and a magnet body having the shapes already described are prepared. In addition, sixteen magnet bodies 82 are prepared for each rotor core 62 in accordance with the number of slots 64 in the rotor core 62. In the present embodiment, the total number of magnet bodies 82 provided in one rotor core 62 is 16. Two sheets 86 are prepared for each rotor core 62. The sheet 86 has a rectangular shape. Each sheet 86 is larger than the total size of the plurality of thin sheets 85. In the present embodiment, the size of one sheet 86 is larger than the total size of the thin sheets 85 for each rotor core 62. In other words, one sheet 86 is wider than the total width of the sixteen thin sheets 85. As Figure 5As shown, the dimension of the short side Y1 of the sheet 86 is longer than the dimension of the long side of the first magnetic surface 82A in the magnet body 82. The dimension of the long side Y2 of the sheet 86 is longer than 32 times the dimension of the short side of the first magnetic surface 82A in the magnet body 82. Further, in the following description, when individually referring to the two sheets 86, they are referred to as the first sheet 86A and the second sheet 86B. When collectively referring to the first sheet 86A and the second sheet 86B, they are referred to as the sheet 86.

[0060] <Intermediate body manufacturing process>

[0061] As Figure 4 shown, after the preparation process S10, an intermediate body manufacturing process S20 is performed. The intermediate body manufacturing process S20 is a process of manufacturing the intermediate body 88 using the intermediate body manufacturing apparatus 200. Further, at the start time of the intermediate body manufacturing process S20, the second pressing die 202 of the intermediate body manufacturing apparatus 200 stops at the initial position. The initial position is a position where the second pressing die 202 is quite far from the first pressing die 201.

[0062] As Figure 5 shown by the arrow U1, in the intermediate body manufacturing process S20, first, for example, the first sheet 86A is disposed in the first recess 201A of the first pressing die 201 in the intermediate body manufacturing apparatus 200 using a robot. Then, as Figure 5 shown by the arrow U2, sixteen magnet bodies 82 are disposed on the first sheet 86A. When disposing each magnet body 82 on the first sheet 86A, the first magnetic surface 82A of each magnet body 82 faces the first sheet 86A. Further, the long side of the first magnetic surface 82A in each magnet body 82 is parallel to the short side Y1 of the first sheet 86A. In this case, the second magnetic surfaces 82B of adjacent magnet bodies 82 face each other. In such a state, the sixteen magnet bodies 82 are arranged in a row with intervals therebetween. The gap between adjacent magnet bodies 82 is shorter than the dimension of the short side of the first magnetic surface 82A in the magnet body 82. After that, as Figure 5As shown by the arrow U3, the second sheet 86B is disposed on the sixteen magnet bodies 82. At this time, the four sides of the second sheet 86B are aligned with the four sides of the first sheet 86A. In this way, a state is formed in which the two sheets 86 cover the upper and lower first magnet surfaces 82A of each magnet body 82. In addition, when the second sheet 86B is viewed from above, the second sheet 86B extends from the sixteen magnet bodies 82. That is, the first sheet 86A also extends from the sixteen magnet bodies 82. Specifically, the first sheet 86A has a first sheet surface 87 and a second sheet surface 89 on the side opposite to the first sheet surface 87. The second sheet 86B has a first sheet surface 87 and a second sheet surface 89 on the side opposite to the first sheet surface 87. The plurality of magnet bodies 82 are arranged on the first sheet surface 87 of the first sheet 86A in such a manner that the first magnet surface 82A contacts the first sheet 86A. The second sheet surface 89 of the first sheet 86A faces the first pressing die 201. The plurality of magnet bodies 82 are arranged on the first sheet surface 87 of the second sheet 86B in such a manner that the first magnet surface 82A contacts the second sheet 86B. The second sheet surface 89 of the second sheet 86B faces the second pressing die 202.

[0063] After that, the intermediate body manufacturing apparatus 200 is driven. Then, as Figure 6 shown by the arrow A, the second pressing die 202 approaches the first pressing die 201. And, the bottom surface of the recess in the first recess 201A of the first pressing die 201 and the bottom surface of the recess in the second recess 202A of the second pressing die 202 sandwich the two sheets 86 and the sixteen magnet bodies 82. At this time, the first sheet 86A is clamped by the bottom surface of the first recess 201A and the first magnet surface 82A of each magnet body 82. The second sheet 86B is similarly clamped by the bottom surface of the second recess 202A and the first magnet surface 82A of each magnet body 82. The second pressing die 202 stops operating at the position where the force applied to the two sheets 86 becomes the specified load N. In addition, the force applied to the two sheets 86 can be grasped based on the detection value of the load sensor 204. For the above-mentioned specified load N, it is, for example, determined in advance by experiments as a magnitude equal to or greater than the minimum load required to elastically compress the glass fiber of the sheet 86 and less than the minimum load at which the glass fiber breaks. In addition, in Figure 6 , in order to represent the two sheets 86 in an easily understandable manner, dots are marked on the first sheet 86A and the second sheet 86B.

[0064] Thereafter, the first pressing die 201 and the second pressing die 202 are heated by the heater H. Moreover, the temperature of the first recess 201A of the first pressing die 201 is made the first specified temperature Z1. In addition, the temperature of the second recess 202A of the second pressing die 202 is made the first specified temperature Z1. The temperature of each of the first recess 201A and the second recess 202A can be grasped based on the detection value of the temperature sensor T. The above-mentioned first specified temperature Z1 is predetermined to be a temperature equal to or higher than the glass transition temperature of the polyetherimide constituting the sheet 86 and lower than the temperature at which the polyetherimide vaporizes. In the present embodiment, the first specified temperature Z1 is determined to be a temperature slightly higher than the glass transition temperature of the polyetherimide.

[0065] The state of heating and pressing the two sheets 86 as described above is maintained for the first specified period L1. For the first specified period L1, for example, it is determined in advance through experiments as the length of time required to soften the polyetherimide to such an extent that the glass fibers of the sheet 86 are elastically compressed in the state where the sheet 86 is at the first specified temperature Z1.

[0066] After the first specified period L1 has elapsed, while maintaining the pressing of the two sheets 86, the temperatures of the first pressing die 201 and the second pressing die 202 are lowered. For example, the temperature of the heating by the heater H is lowered, or cooling water is made to flow through the cooling water passage W. Then, the temperature of the first recess 201A of the first pressing die 201 is made the second specified temperature Z2. In addition, the temperature of the second recess 202A of the second pressing die 202 is made the second specified temperature Z2. The second specified temperature Z2 is predetermined to be a temperature lower than the glass transition temperature of the polyetherimide. In the present embodiment, the second specified temperature Z2 is determined to be a temperature slightly lower than the glass transition temperature of the polyetherimide.

[0067] While maintaining the pressing of the two sheets 86, the state in which the first recess 201A of the first pressing die 201 and the second recess 202A of the second pressing die 202 are maintained at the second specified temperature Z2 is maintained for the second specified period L2. For the second specified period L2, for example, it is determined in advance through experiments as the length of time required to cure the polyetherimide of the sheet 86 in the state where the sheet 86 is at the second specified temperature Z2.

[0068] After the above-mentioned second specified period L2 has elapsed, the second pressing die 202 is returned to the initial position. Then, in the first recess 201A of the first pressing die 201, there is an intermediate body 88 in which sheets 86 are thermocompression bonded to the upper and lower first magnetic surfaces 82A of each magnet body 82. At this moment, the inorganic fibers of the two sheets 86 are in a state of elastic compression. The above series of processes of the intermediate body manufacturing apparatus 200 is the intermediate body manufacturing process S20. Further, as described above, in the intermediate body 88, the two first magnetic surfaces 82A of each magnet body 82 are respectively covered by the sheets 86. In other words, in the intermediate body 88, one of the two first magnetic surfaces 82A of each magnet body 82 is on the same surface as the first sheet 86A, and the other first magnetic surface 82A of each magnet body 82 is on the same surface as the second sheet 86B. In other words, the plurality of magnet bodies 82 are located on the first sheet surface 87 of the first sheet 86A and are not located on the second sheet surface 89 of the first sheet 86A. The plurality of magnet bodies 82 are located on the first sheet surface 87 of the second sheet 86B and are not located on the second sheet surface 89 of the second sheet 86B.

[0069] <Configuration Process>

[0070] As Figure 4 shown, after the intermediate body manufacturing process S20, a configuration process S30 is performed. The configuration process S30 is a process of disposing the intermediate body 88 in the cutting device 300. Further, at the start time of the configuration process S30, the second base member 302 and the second die 304 of the cutting device 300 stop at the initial position. The initial position is a position where the second die 304 is considerably separated from the first die 303. In this state, for example, the intermediate body 88 is disposed on the upper surface of the first die 303 by using a robot as Figure 7 shown. At this time, the first sheet 86A faces the upper surface of the first die 303. That is, the second sheet surface 89 on the side of the first sheet 86A opposite to the first sheet surface 87 where the first magnetic surface 82A of the magnet body 82 is located faces the upper surface of the first die 303. Further, the second sheet surface 89 on the side of the second sheet 86B opposite to the first sheet surface 87 where the first magnetic surface 82A of the magnet body 82 is located faces the lower surface of the second die 304. That is, the intermediate body 88 is disposed between the first die 303 and the second die 304 such that the second sheet surface 89 of the first sheet 86A faces the first die 303 and the second sheet surface 89 of the second sheet 86B faces the second die 304. Further, as Figure 6 the same as Figure 7 in, points are marked on the first sheet 86A and the second sheet 86B.

[0071] <Cutting Process>

[0072] As Figure 4 shown, after the configuration process S30, the cutting process S40 is performed. The cutting process S40 is a process of cutting two sheets 86 in the intermediate body 88. In the cutting process S40, the cutting device 300 is driven. Then, as shown by the arrow B in Figure 8 , the second die 304 approaches the first die 303 together with the second base member 302. Then, the first die 303 and the second die 304 clamp the intermediate body 88. When the second die 304 moves to the specified approaching position Q, the second base member 302 and the second die 304 stop operating. Then, in this state, it stands by for the standby period M. The standby period M is, for example, 5 seconds. During this standby period M, the two sheets 86 are cut according to each magnet body 82. That is, the two sheets 86 are cut at the positions between adjacent magnet bodies 82, or along the long side or the short side of the first magnetic surface 82A of each magnet body 82. Therefore, by cutting each sheet 86, a number of thin sheets 85 corresponding to the number of magnet bodies 82 are generated from each sheet 86. In addition, the mechanism for cutting the sheet 86 will be described in the column of the action described later. In addition, for the above-mentioned approaching position Q, as the position of the second die 304 when the force required to cut the sheet 86 is applied to the intermediate body 88, it is determined in advance by experiments, for example. In addition, for the standby period M, as the length of the time required to complete the cutting of the sheet 86 in the state where the second die 304 stops at the approaching position Q, it is determined in advance by experiments, for example. Similarly to Figure 7 , in Figure 8 , dots are marked on the first sheet 86A, the second sheet 86B, and the thin sheet 85.

[0073] After that, the second die 304 and the second base member 302 are returned to the initial position together. Then, sixteen magnets 80 and the waste of the sheet 86 remain on the upper surface of the first die 303. In addition, the magnet 80 has a magnet body 82 and thin sheets 85 that respectively cover the two first magnetic surfaces 82A in the magnet body 82.

[0074] <Insertion Process>

[0075] As Figure 4 shown, after the cutting process S40, the insertion process S50 is performed. The insertion process S50 is a process of inserting the magnets 80 into the respective slots 64 of the rotor core 62. As shown in Figure 9As shown, in the insertion step S50, for example, the disk-shaped support disk 400 is disposed substantially horizontally. Then, the rotor core 62 is disposed above the support disk 400. Each slot 64 has two openings at both ends in a direction parallel to the central axis J of the rotor core 62. When the rotor core 62 is disposed above the support disk 400, one of the two openings of each slot 64 faces the support disk 400, and the other opening faces upward. Then, as shown by the arrow C in Figure 9 , for example, a magnet 80 is inserted into each slot 64 of the rotor core 62 on the support disk 400 by means of a robot.

[0076] In addition, at the stage of manufacturing the magnet 80 through the cutting step S40, the thin sheet 85 of the magnet 80 is in a state compressed by the thermocompression bonding to the magnet body 82 based on the intermediate manufacturing step S20. Therefore, the thickness of the magnet 80 including the thin sheet 85 is smaller than the dimension in the width direction of the slot 64 in the rotor core 62. Thus, when the magnet 80 is inserted into the slot 64 in the insertion step S50, the magnet 80 quickly moves into the slot 64.

[0077] <Fixing Step>

[0078] As shown in Figure 4 , after the insertion step S50, a fixing step S60 is performed. The fixing step S60 is a step of fixing the magnet 80 to the rotor core 62. As shown in Figure 10 , in the fixing step S60, a furnace 500 capable of adjusting the temperature is used. Specifically, in the fixing step S60, the rotor core 62 and the support disk 400 with the magnet 80 inserted into each slot 64 are disposed together in the furnace 500. Then, the rotor core 62 is heated in the furnace 500. At this time, the temperature in the furnace 500 is adjusted to a third specified temperature Z3. The third specified temperature Z3 is predetermined to be a temperature equal to or higher than the glass transition temperature of the polyetherimide forming the thin sheet 85 and lower than the temperature at which the polyetherimide vaporizes. In the present embodiment, the third specified temperature Z3 is determined to be the same temperature as the first specified temperature Z1. Figure 10 The double-dot dash line in Figure 10 indicates the position of the thin sheet 85 in a state where the glass fiber is elastically compressed. That is, Figure 9 the double-dot dash line in

[0079] The heating of the rotor core 62 in the furnace 500 continues for a third specified period L3. For the third specified period L3, the length of time required to soften the polyetherimide to a degree sufficient for the glass fibers of the sheet 85 to elastically recover in a state where the sheet 85 is at a third specified temperature Z3 is determined in advance through experiments or the like. After the heating of the rotor core 62 is continued for the third specified period L3, the rotor core 62 is taken out of the furnace 500. Thereafter, the rotor core 62 is returned to normal temperature. Thus, the rotor 60 is completed.

[0080] <Function of the Embodiment>

[0081] (I) Regarding the mechanism of fixing the magnet to the slot

[0082] As Figure 6 shown, in the intermediate production process S20, the first recess 201A of the first pressing die 201 and the second recess 202A of the second pressing die 202 are heated to a first specified temperature Z1 which is a temperature higher than the glass transition temperature of the polyetherimide. Along with this, the polyetherimide of the sheet 86 located on the first magnetic surface 82A of each magnet body 82 softens. On this basis, in the intermediate production process S20, the sheet 86 is pressed. Therefore, the glass fibers of the sheet 86 are in a state of being flexed and elastically compressed. Moreover, in the intermediate production process S20, while maintaining the state of pressing the sheet 86 unchanged, the first recess 201A of the first pressing die 201 and the second recess 202A of the second pressing die 202 are cooled to a second specified temperature Z2 which is a temperature lower than the glass transition temperature of the polyetherimide. Therefore, the sheet 86 is bonded to the first magnetic surface 82A of each magnet body 82 while maintaining the state of elastic compression of the glass fibers unchanged.

[0083] For the above reasons, in each magnet 80 at the time of production in the cutting process S40, the sheet 85 is in a state of elastic compression. In the fixing process S60, such a sheet 85 is heated again to a third specified temperature Z3 which is a temperature higher than the glass transition temperature of the polyetherimide. Along with this, the polyetherimide of the sheet 85 softens again. Then, the glass fibers after elastic compression elastically recover. Along with this, as Figure 10 the arrow D in Figure 10 shows, the sheet 85 expands from the position where the glass fibers shown by the double-dot dash line in

[0084] (II) Regarding the mechanism of cutting the sheet

[0085] AsFigure 8 As shown, in the cutting process S40, the first die 303 and the second die 304 sandwich the intermediate body 88. That is, the first die 303 and the second die 304 are pressed against the intermediate body 88. Along with the elastic deformation of the first die 303 and the second die 304 at this time, the sheet 86 is cut. Hereinafter, taking the first die 303 as an example, the relationship between the elastic deformation of the first die 303 and the cutting of the sheet 86 will be described.

[0086] As Figure 8 shown, in a state where the first die 303 is pressed against the first sheet 86A, the first die 303 is flattened from above and below by the first base member 301 and the first magnetic surface 82A of the magnet body 82. Therefore, as Figure 8 indicated by the arrow B1 in, a portion directly below the first magnetic surface 82A of the magnet body 82 in the first die 303 elastically deforms in a manner extending laterally. That is, since the portion of the first die 303 between the first base member 301 and the magnet body 82 is flattened by the first base member 301 and the magnet body 82, it is pushed out laterally with respect to the first base member 301 and the magnet body 82. It can be said that the lateral direction refers to the lateral direction with respect to the direction in which the magnet body 82 flattens the first die 303. In other words, the lateral direction refers to the lateral direction with respect to the driving direction of the cutting device 300 indicated by the arrow B. Or, it can be said that the lateral direction refers to the direction parallel to the first magnetic surface 82A of the magnet body 82. Or, it can be said that the lateral direction refers to the direction parallel to the first base member 301. The first die 303 deforms laterally in this way, and furthermore, as Figure 8 indicated by the arrow B2 in, it also elastically deforms in a manner of entering between adjacent magnet bodies 82. That is, the portion of the first die 303 between the first base member 301 and the magnet body 82 is pushed out laterally with respect to the first base member 301 and the magnet body 82, and furthermore, it deforms in a manner of retreating into the space between adjacent magnet bodies 82. The first die 303 that deforms laterally and enters between adjacent magnet bodies 82 attempts to expand the region between adjacent magnet bodies 82 laterally. That is, a force in the direction of moving away from each other acts on adjacent magnet bodies 82. Therefore, the distance between adjacent magnet bodies 82 may sometimes become longer. As a result, since a large tension is applied to the portion between adjacent magnet bodies 82 in the first sheet 86A, the first sheet 86A is cut.

[0087] In addition, the sheet 86 is also cut due to the influence of the shape of the magnet body 82. The boundary 82S between the first magnetic surface 82A and the second magnetic surface 82B in the magnet body 82 has sharp corners. The boundary 82T between the first magnetic surface 82A and the third magnetic surface 82C in the magnet body 82 also has sharp corners. Therefore, when the first mold 303 is pressed against the intermediate body 88, it is easy to apply force to the above-mentioned boundaries 82S and 82T in the magnet body 82 from the first mold 303. As a result, the first sheet 86A facing the first mold 303 is cut at the portions in contact with the above-mentioned boundaries 82S and 82T.

[0088] As described above, the cutting mechanism of the sheet 86 has been described by taking the first mold 303 and the first sheet 86A as examples, but it can be said that the same applies to the second mold 304 and the second sheet 86B.

[0089] In addition, at various locations of the intermediate body 88, there are portions where the sheet 86 is cut mainly due to the force acting to increase the distance between adjacent magnet bodies 82, and there are also portions where the sheet 86 is cut mainly due to the contact between the sheet 86 and the corner portions of the magnet body 82. In addition, there are also portions where the above two mechanisms overlap to cut the sheet 86. That is, in a state where a large tension is applied to the sheet 86 by acting in a manner that increases the distance between adjacent magnet bodies 82, the sheet 86 is cut by the corner portions of the magnet body 82.

[0090] <Effect of the Embodiment>

[0091] (1) As described in the above operation, when the first mold 303 and the second mold 304 are pressed against the intermediate body 88 in the cutting step S40, the first mold 303 and the second mold 304 elastically deform in a manner extending laterally with respect to the pressing direction, and elastically deform in a manner of entering between adjacent magnet bodies 82. As a result, forces in the direction of moving away from each other act on adjacent magnet bodies 82. As a result, the sheet 86 is cut at the position between adjacent magnet bodies 82. Such cutting of the sheet 86 occurs at various locations of adjacent magnet bodies 82. Therefore, the sheet 86 can be cut efficiently.

[0092] (2) As described in the above function, when the first die 303 and the second die 304 are pressed against the intermediate body 88, it is easy to apply a force from the first die 303 and the second die 304 to the boundary 82S between the first magnetic surface 82A and the second magnetic surface 82B and the boundary 82T between the first magnetic surface 82A and the third magnetic surface 82C in the magnet body 82. Therefore, the sheet 86 can be cut at the above boundaries 82S and 82T. In addition, when the sheet 86 is cut at the boundaries 82S and 82T between the surfaces of the magnet body 82 in this way, the sheet 86 can be cut along the outer edge of the magnet body 82. Therefore, a magnet 80 can be produced in a form with less excess thin sheet 85 protruding from the magnet body 82.

[0093] (3) As described in the above function, the sheet 86 containing thermoplastic resin fibers and inorganic fibers is thermally bonded to the magnet body 82. After that, when the thermoplastic resin fibers and the inorganic fibers are heated again, the thermoplastic resin fibers in the thin sheet 85 are softened again. Therefore, due to the action of the inorganic fibers restored by elastic compression, the thin sheet 85 expands. This characteristic is utilized in the fixing process S60. In the fixing process S60, the magnet 80 is fixed to the rotor core 62 by expanding the thin sheet 85 thermally bonded to the magnet body 82 in the slot 64 of the rotor core 62. On the basis of fixing the magnet 80 to the rotor core 62 in this way, in the present embodiment, in the intermediate body manufacturing process S20, the sheet 86 is thermally bonded to the sixteen magnet bodies 82 in advance. Therefore, in the cutting process S40, sixteen magnets 80 in a state where the thin sheet 85 is thermally bonded to the magnet body 82 can be produced. That is, at the end of the cutting process S40, the thin sheet 85 has already been thermally bonded to the magnet body 82. Therefore, in the fixing process S60, as long as the above sixteen magnets 80 are heated in the slot 64 of the rotor core 62, the magnet 80 can be fixed to the rotor core 62. Therefore, as long as the manufacturing method of the rotor 60 of the present embodiment is used, the rotor 60 can be manufactured very efficiently.

[0094] In addition, the present embodiment can be implemented with the following modifications. The present embodiment and the following modification examples can be implemented in combination with each other within the range where there is no technical contradiction.

[0095] · The structure of the cutting device 300 used in the cutting process S40 is not limited to the example of the above embodiment. The cutting device 300 only needs to have a structure that can cut the sheet 86 by clamping the intermediate body 88 with the first die 303 and the second die 304. For example, as Figure 11Like the cutting device 350 shown, the upper surface of the first die 353 may also have a flat surface 353P in a planar shape and a protruding surface 353B protruding from the flat surface 353P. Specifically, a plurality of convex portions 353A protrude from the flat surface 353P of the first die 353. The surface of the convex portion 353A includes the protruding surface 353B. The plurality of convex portions 353A are arranged in a row at equal intervals. Specifically, the plurality of convex portions 353A are provided according to the respective dimensions of the short side of the first magnetic surface 82A of the magnet body 82. The protruding end of each convex portion 353A is in a planar shape. That is, a part of the protruding surface 353B is in a planar shape. Similarly, a plurality of convex portions 354A protrude from the flat surface 354P of the second die 354. The surface of the convex portion 354A is the protruding surface 354B. Each convex portion 354A of the second die 354 is located at a position facing each convex portion 353A of the first die 353.

[0096] When using the cutting device 350 as described above, in the intermediate body manufacturing process S20, the intermediate body 88 is manufactured in a state where there is almost no gap between the respective magnet bodies 82. Then, in the arranging process S30, the intermediate body 88 is arranged in such a manner that the boundary 82S between the first magnetic surface 82A and the second magnetic surface 82B facing downward in the magnet body 82 faces the protruding surface 353B of the first die 353 with the first sheet 86A interposed therebetween. When arranging the intermediate body 88 in this way, the boundary 82S between the first magnetic surface 82A and the second magnetic surface 82B facing upward in the magnet body 82 faces the protruding surface 354B of the second die 354. Under such an arrangement, the cutting process S40 is performed.

[0097] When the convex portion 353A is provided on the upper surface of the first die 353 as described above, if the first die 353 is pressed against the intermediate body 88, in the first die 353, the force easily acts on the first sheet 86A from the protruding surface 353B of the first die 353. Specifically, a very strong force is applied to the portion of the first sheet 86A clamped by the protruding surface 353B of the first die 353 and the boundary 82S of the magnet body 82. Therefore, at this portion of the first sheet 86A, the first sheet 86A can be more reliably cut. It can be said that the same applies to the cutting of the second sheet 86B and the protruding surface 354B of the second die 354. In addition, in Figure 11 the illustration of the first base member 301 and the second base member 302 is omitted. In addition, in Figure 11 the Figure 7 similarly, dots are marked on the first sheet 86A and the second sheet 86B.

[0098] · As Figure 12Like the cutting device 370 shown, a plurality of convex portions may be irregularly provided on the upper surface of the first die 373. That is, continuous irregularities exist on the upper surface of the first die 373. For example, as in Figure 7 the above-described embodiment shown, when the upper surface of the first die 303 is planar, the force applied to the intermediate body 88 from the upper surface of the first die 303 is substantially uniform everywhere on the upper surface of the first die 303. On the other hand, as in Figure 12 shown, when a plurality of convex portions are irregularly provided on the upper surface of the first die 373, the force applied to the intermediate body 88 from the upper surface of the first die 373 is different everywhere on the upper surface of the first die 373. And, depending on the location, a locally strong force is applied to the intermediate body 88. Since there are multiple locations on the first die 373 where such a locally strong force is applied, for example, between the first base member 301 and each magnet main body 82, the first die 373 will elastically deform irregularly, and thus, the force may act in a manner that separates adjacent magnet main bodies 82 from each other. Therefore, the sheet 86 can be cut. In addition, by applying a locally strong force to the boundary 82S between the first magnetic surface 82A and the second magnetic surface 82B of the magnet main body 82, the sheet 86 can be cut using this boundary 82S. Similarly to the first die 373, irregularities may also be provided on the lower surface of the second die 374. In addition, in Figure 12 , the illustration of the first base member 301 and the second base member 302 is omitted. In addition, in Figure 12 , similar to Figure 7 , dots are marked on the first sheet 86A and the second sheet 86B.

[0099] · The Shore hardness of the first die 303 is not limited to the example of the above-described embodiment. It can also be considered that if the Shore hardness of the first die 303 is large, even if the force pressing the first die 303 against the intermediate body 88 is small, the sheet 86 can be cut. And, if the force pressing the first die 303 against the intermediate body 88 is small, it is difficult to apply a load to the first die 303, which is advantageous from the viewpoint of the durability of the first die 303. It is only necessary to set an appropriate Shore hardness in consideration of such durability of the first die 303 and also in consideration of, for example, cost. The same applies to the Shore hardness of the second die 304. In the first die 303 and the second die 304, the Shore hardness may also be different from each other.

[0100] · In the first die 303 and the second die 304, the elastic moduli may also be different from each other. The elastic modulus of the first die 303 only needs to be smaller than that of the magnet main body 82. The same applies to the second die 304. The elastic modulus of the second die 304 only needs to be smaller than that of the magnet main body 82.

[0101] · The material of the first mold 303 is not limited to the examples of the above-described embodiments. The first mold 303 only needs to be made of an elastic material. For example, the material of the first mold 303 can also be a thermoplastic elastomer. The same applies to the second mold 304. In the first mold 303 and the second mold 304, the materials can also be different from each other.

[0102] · As in the modification example described later, when only one sheet 86 constituting the intermediate body 88 is provided, the first mold 303 only needs to be made of an elastic material, and the second mold 304 does not have to be made of an elastic material. In this case, in the arranging step S30, it is only necessary to face the sheet 86 with the first mold 303.

[0103] · Regarding the arrangement of the first mold 303 and the second mold 304, the first mold 303 and the second mold 304 can also be arranged by swapping their positions up and down from the form of the above-described embodiment. That is, the first mold 303 can also be located above the second mold 304.

[0104] · The first mold 303 and the second mold 304 can be arranged facing each other and arranged in the gravitational direction, or can be arranged along the horizontal plane. For example, when the first mold 303 and the second mold 304 are arranged along the horizontal plane, in the arranging step S30, for example, the intermediate body 88 is suspended between the first mold 303 and the second mold 304. Then, in the cutting step S40, the intermediate body 88 is clamped by the first mold 303 and the second mold 304 from both sides in the direction along the horizontal plane. By adopting such a form, the sheet 86 can also be cut.

[0105] · The mechanism for driving the cutting device 300 can also be changed from the examples of the above-described embodiments. For example, the cutting device 300 can also be driven by hydraulic pressure.

[0106] · The standby period M of the cutting step S40 is not limited to the example of 5 seconds in the above-described embodiment. The standby period M only needs to be the length of time required to complete the cutting of the sheet 86.

[0107] · The method for manufacturing the intermediate body 88 in the intermediate body manufacturing step S20 is not limited to the examples of the above-described embodiments. For example, as Figure 13As shown, a pressing jig 600 can also be used to fabricate the intermediate body 88. The pressing jig 600 has, for example, a first plate 601 and a second plate 602 made of copper. When fabricating the intermediate body 88 using the pressing jig 600, first, a first sheet 86A is disposed on the first plate 601. Then, a plurality of magnet bodies 82 are disposed on the first sheet 86A. After that, a second sheet 86B is disposed on the plurality of magnet bodies 82. Then, the second plate 602 is disposed on the second sheet 86B. In this way, the plurality of magnet bodies 82 covered by the two sheets 86 are clamped by the first plate 601 and the second plate 602. Then, with a predetermined load N applied to the two sheets 86, the first plate 601 and the second plate 602 are fixed using bolts 603. In this fixed state, each magnet body 82 and the two sheets 86 are disposed together with the pressing jig 600 in a furnace 650. The furnace 650 can adjust the temperature. After that, the state in which the temperature inside the furnace 650 is the first predetermined temperature Z1 is maintained for a first predetermined period L1. After that, the state in which the temperature inside the furnace 650 is the second predetermined temperature Z2 is maintained for a second predetermined period L2. After that, the pressing jig 600 is taken out from the furnace 650. Then, when the second plate 602 is removed together with the bolts 603, the intermediate body 88 is completed. The intermediate body 88 can be fabricated in this way. In addition, in Figure 13 the same way as Figure 6 in, dots are marked on the first sheet 86A and the second sheet 86B.

[0108] · The structure of the intermediate body 88 is not limited to the examples of the above-described embodiments. For example, the number of magnet bodies 82 included in the intermediate body 88 can be changed from the number in the above-described embodiment, which is sixteen. The number of magnet bodies 82 included in the intermediate body 88 can also be more than the number of slots 64 of one rotor core 62. The number of magnet bodies 82 included in the intermediate body 88 only needs to be two or more.

[0109] · The arrangement of the magnet bodies 82 in the intermediate body 88 is not limited to the examples of the above-described embodiments. For example, a plurality of magnet bodies 82 can be arranged in multiple columns.

[0110] · In the intermediate body 88, there may also be no gap at all between adjacent magnet bodies 82. Even when the first die 303 and the second die 304 are pressed against such an intermediate body 88, the sheet 86 will be cut according to the elastic deformation of the first die 303 and the second die 304. That is, when the first die 303 is pressed against the intermediate body 88, the first die 303 is flattened between the first base member 301 and each magnet body 82, and the first die 303 elastically deforms in a manner extending in the lateral direction. Along with such elastic deformation, the first die 303 applies a force to the magnet bodies 82 in a manner that makes the adjacent magnet bodies 82 move away from each other. Therefore, the sheet 86 is cut at the position between the adjacent magnet bodies 82. The second die 304 can also cut the sheet 86 in the same manner.

[0111] · The shape and size of the sheet 86 are not limited to the examples of the above-described embodiments. The shape and size of the sheet 86 may be appropriately adjusted as long as they can cover the plurality of magnet bodies 82 constituting the intermediate body 88.

[0112] · The intermediate body 88 may not thermally bond the sheet 86 to the plurality of magnet bodies 82. For example, the intermediate body 88 may paste the sheet 86 on the plurality of magnet bodies 82 by an adhesive or a double-sided adhesive tape. In this case, if the sheet 86 can be temporarily fixed to the magnet body 82, since it is sufficient for the cutting process S40, the adhesive force of the adhesive or the double-sided adhesive tape may not be so high. In the case of adopting such an intermediate body 88, it is only necessary to thermally bond the sheet 86 to the magnet body 82 after the cutting process S40. The intermediate body 88 only needs to have a structure in which the plurality of magnet bodies 82 are located on the same surface of the sheet 86. In other words, the intermediate body 88 only needs to be configured such that the plurality of magnet bodies 82 are located on the first sheet surface 87 of the sheet 86.

[0113] · The sheet 86 constituting the intermediate body 88 may be provided as only one piece. That is, the intermediate body 88 may have a structure in which the sheet 86 covers only one of the two first magnet surfaces 82A of each magnet body 82.

[0114] · The structure of the intermediate body manufacturing apparatus 200 is not limited to the examples of the above-described embodiments. The intermediate body manufacturing apparatus 200 only needs to have a structure capable of applying pressure while heating the sheet 86. For example, the mechanism for driving the intermediate body manufacturing apparatus 200 may be changed from the examples of the above-described embodiments. For example, the intermediate body manufacturing apparatus 200 may be driven by hydraulic pressure.

[0115] · The material of the first pressing die 201 is not limited to the examples of the above-described embodiments. For example, the first pressing die 201 can also be made of iron. The same applies to the second pressing die 202. In the first pressing die 201 and the second pressing die 202, the materials can also be different from each other.

[0116] · As in the above modification example, when the sheet 86 constituting the intermediate 88 is one, the heater H built in either the first pressing die 201 or the second pressing die 202 is not necessarily required. In this case, the unnecessary heater H can also be abolished. The same applies to the cooling water passage W. In addition, for the cooling water passage W, it can also be abolished from both the first pressing die 201 and the second pressing die 202. In this case, it is also possible to cool the intermediate manufacturing apparatus 200 by leaving time after stopping the heater H.

[0117] · As a mechanism for cooling the first pressing die 201, a structure other than the cooling water passage W can also be used. The same applies to the mechanism for cooling the second pressing die 202.

[0118] · It can also be that the first specified temperature Z1 in the intermediate manufacturing process S20 is considerably higher than the glass transition temperature of the thermoplastic resin fiber.

[0119] · It can also be that the second specified temperature Z2 in the intermediate manufacturing process S20 is considerably lower than the glass transition temperature of the thermoplastic resin fiber. The second specified temperature Z2 can also be, for example, room temperature.

[0120] · The third specified temperature Z3 in the fixing process S60 can also be different from the first specified temperature Z1 in the intermediate manufacturing process S20.

[0121] · The method of heating the thin sheet 85 in the fixing process S60 is not limited to the examples of the above-described embodiments. For example, high-frequency induction heating can also be used. That is, the rotor core 62 with the magnet 80 housed in the slot 64 is arranged inside the coil for induction heating. And it can also be that a magnetic field is generated by passing an electric current through the coil, thereby heating the rotor core and the thin sheet 85.

[0122] · The type of the permanent magnet constituting the magnet main body 82 is not limited to the examples of the above-described embodiments. The magnet main body 82 only needs to be a permanent magnet. As examples of the permanent magnet used for the magnet main body 82, at least one of a ferrite magnet, an alnico magnet, a samarium-cobalt magnet, a neodymium magnet, a samarium-nitrogen-iron magnet, a platinum magnet, or a cerium-cobalt magnet can be cited.

[0123] · The shape of the magnet body 82 is not limited to the examples of the above-described embodiments. For example, chamfering may be performed on the boundary portion between the first magnetic surface 82A and the second magnetic surface 82B. In this case, the first magnetic surface 82A and the second magnetic surface 82B are also adjacent to each other with the chamfered surface therebetween. Additionally, the first magnetic surface 82A may be curved. Moreover, the magnet body 82 only needs to be in a shape that can be accommodated in the slot 64 of the rotor core 62.

[0124] In addition, it can be considered that there is no angular portion in the magnet body 82 by changing the shape of the magnet body 82 from the examples of the above-described embodiments. In this case, by elastically deforming the first mold 303 and the second mold 304, a force can also be applied to the magnet body 82 to move the adjacent magnet bodies 82 away from each other, thereby cutting the sheet 86.

[0125] · The types of thermoplastic resin fibers constituting the sheet 86 and the thin sheet 85 are not limited to the examples of the above-described embodiments. The thermoplastic resin fibers can be, for example, polyethersulfone or polysulfone. Here, when the motor 50 is in use, the rotor 60 may become hot. Additionally, depending on the usage environment of the motor 50, water or oil may splash onto the rotor 60, or an external force may act on the rotor 60. Considering such a situation, the thermoplastic resin fibers are preferably thermoplastic resin fibers having at least one of high heat resistance, water resistance, oil resistance, creep resistance, heat shock resistance, or insulation.

[0126] · As in the above-described modification example, when the types of thermoplastic resin fibers constituting the sheet 86 and the thin sheet 85 are changed, the first specified temperature Z1 of the intermediate production process S20 can be appropriately changed according to the glass transition temperature of the thermoplastic resin fibers used. The first specified temperature Z1 only needs to be determined as a temperature that is equal to or higher than the glass transition temperature of the thermoplastic resin fibers used and lower than the temperature at which the thermoplastic resin fibers vaporize. The same applies to the third specified temperature Z3 of the fixing process S60.

[0127] · Similarly to the above-described modification example, the second specified temperature Z2 can be changed according to the glass transition temperature of the thermoplastic resin fibers used. The second specified temperature Z2 only needs to be determined as a temperature that is lower than the glass transition temperature of the thermoplastic resin fibers used.

[0128] · The types of inorganic fibers constituting the sheet 86 and the thin sheet 85 are not limited to the examples of the above-described embodiments. As the inorganic fibers, for example, at least one of asbestos, carbon fiber, alumina fiber, calcium silicate fiber, potassium titanate fiber, or ceramic fiber can be used.

[0129] ·When the types of inorganic fibers constituting the sheet 86 and the thin sheet 85 are changed as in the above modification example, the specified load N in the intermediate production process S20 may be appropriately changed according to the inorganic fibers used. The specified load N only needs to be determined to be equal to or greater than the minimum load required to elastically compress the inorganic fibers used and less than the minimum load at which the inorganic fibers used are damaged.

[0130] ·When changing the type of thermoplastic resin fibers or the type of inorganic fibers constituting the sheet 86 and the thin sheet 85, the first specified period L1 in the intermediate production process S20 may be appropriately changed according to the combination of the thermoplastic resin fibers and the inorganic fibers. The first specified period L1 only needs to be determined to be the length of the time required to soften the inorganic plastic resin fibers to an extent sufficient to elastically compress the inorganic fibers of the sheet 86 in a state where the sheet 86 is at the first specified temperature Z1. Similarly to the first specified period L1, for the second specified period L2 in the intermediate production process S20 and the third specified period L3 in the fixing process S60, they only need to be appropriately changed according to the combination of the thermoplastic resin fibers and the inorganic fibers.

[0131] ·The arrangement of the slots 64 in the rotor core 62 is not limited to the example of the above embodiment. The slots 64 may not be arranged in a V - shaped configuration as in the above embodiment, but may be arranged, for example, along the circumferential direction of the rotor core 62. As long as the magnets 80 can be arranged in such a way that the N - poles and S - poles are alternately arranged in the circumferential direction of the rotor core 62, the arrangement of the slots 64 is arbitrary.

[0132] ·The number of slots 64 in the rotor core 62 is not limited to the example of the above embodiment. Similarly to the above modification example, as long as the magnetic poles can be appropriately formed, the number of slots 64 is arbitrary.

[0133] ·If high efficiency is not emphasized in the manufacture of the rotor 60, it is not necessary to use the method of thermally expanding the thin sheet 85 on the basis of fixing the magnet 80 to the rotor core 62. If the magnet 80 is fixed to the rotor core 62 by a method other than the method of thermally expanding the thin sheet 85, the sheet 86 and the thin sheet 85 may not contain thermoplastic resin fibers and inorganic fibers. Regardless of the structure of the sheet 86, it is effective to use the cutting device 300 in the aspect of manufacturing a plurality of magnets 80 by cutting the sheet 86 of the intermediate body 88.

[0134] ·In applications for manufacturing magnets to be installed on components other than the rotor 60, a plurality of magnets can also be manufactured by using the cutting device 300.

Claims

1. A method for manufacturing a magnet, wherein: The manufacturing method includes: A step of manufacturing an intermediate body, the intermediate body having a sheet and a plurality of magnet bodies, the sheet having a first sheet surface and a second sheet surface on the side opposite to the first sheet surface, and the plurality of magnet bodies being located on the first sheet surface; A step of disposing the intermediate body between a first mold and a second mold, the first mold being made of an elastic material having an elastic modulus smaller than that of the magnet body, and the second mold facing the first mold, and disposing the intermediate body between the first mold and the second mold such that the second sheet surface of the sheet faces the first mold; And A step of sandwiching the intermediate body between the first mold and the second mold and cutting the sheet at positions between adjacent magnet bodies while the first mold and the second mold are elastically deformed.

2. The method for manufacturing a magnet according to claim 1, wherein: The magnet body has a planar first magnet surface and a planar second magnet surface adjacent to the first magnet surface, In the step of manufacturing the intermediate body, the plurality of magnet bodies are disposed on the first sheet surface of the sheet such that the first magnet surface contacts the sheet.

3. The method for manufacturing a magnet according to claim 2, wherein: The surface of the first mold facing the sheet has a planar flat surface and a protruding surface protruding from the flat surface, In the step of disposing the intermediate body between the first mold and the second mold, there is a step of disposing the intermediate body such that the boundary between the first magnet surface and the second magnet surface of the magnet body and the protruding surface sandwich the sheet therebetween and face each other.

4. The method for manufacturing a magnet according to any one of claims 1 to 3, wherein: The sheet includes thermoplastic resin fibers and inorganic fibers, In the step of manufacturing the intermediate body, there is a step of thermally pressing the sheet to the plurality of magnet bodies in a state where the inorganic fibers are elastically compressed by heating the sheet to a temperature above the glass transition temperature of the thermoplastic resin fibers and pressing the sheet.

5. A method for manufacturing a rotor, wherein The manufacturing method includes: A step of manufacturing an intermediate body, the intermediate body having a sheet and a plurality of magnet bodies, the sheet having a first sheet surface and a second sheet surface on the side opposite to the first sheet surface, the sheet including thermoplastic resin fibers and inorganic fibers, and by heating the sheet to a temperature above the glass transition temperature of the thermoplastic resin fibers and pressing the sheet while the plurality of magnet bodies are located on the first sheet surface of the sheet, the sheet is thermally pressed to the plurality of magnet bodies in a state where the inorganic fibers are elastically compressed; A step of disposing the intermediate between a first mold and a second mold, wherein the first mold is made of an elastic material having an elastic modulus smaller than that of the magnet body, and the second mold faces the first mold, and the intermediate is disposed between the first mold and the second mold in such a manner that the second sheet surface of the sheet faces the first mold; A step of cutting the sheet, in order to manufacture a magnet, the intermediate is sandwiched by the first mold and the second mold, and the sheet is cut at a position between adjacent magnet bodies with elastic deformation of the first mold and the second mold. The magnet includes the magnet body and a thin sheet generated by cutting the sheet and covering the magnet body; And A step of fixing the magnet to the rotor core, by heating the magnet to a temperature above the glass transition temperature in a state where the magnet is disposed in a slot formed in the rotor core, thereby fixing the magnet to the rotor core. By heating the magnet to a temperature above the glass transition temperature, the inorganic fibers elastically recover, thereby fixing the magnet to the rotor core.

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