JP2022142737A - Magnet producing method and rotor producing method - Google Patents

Abstract

To efficiently cut a sheet material covering a surface of a magnet body.SOLUTION: An intermediate body 88 in which a plurality of magnet bodies 82 are located on the same surface of a first sheet material 86A is prepared. Then, the intermediate body 88 is placed between a first mold 303 made from an elastic material having an elastic modulus smaller than that of the magnet bodies 82 and a second mold 304 facing the first mold 303. Then, the first mold 303 and the second mold 304 sandwich the intermediate body 88, whereby the first sheet material 86A is cut between the adjacently arranged magnet bodies 82.SELECTED DRAWING: Figure 8

Description

The present invention relates to a magnet manufacturing method and a rotor manufacturing method.

The rotor of the motor disclosed in Patent Document 1 has a rotor core and a plurality of magnets. A plurality of slots are vacant in the rotor core. A plurality of magnets are positioned within each slot.

Japanese Patent No. 05967297

As a rotor magnet as disclosed in Patent Document 1, a magnet having a sheet-like film attached to the surface of a magnet body may be used. However, it is troublesome to cut the sheet material, which is the material of the film, one by one according to the shape of each magnet body. Therefore, a technique for efficiently cutting the sheet material for covering the surface of the magnet body is desired.

A method of manufacturing a magnet for solving the above problems includes an intermediate body manufacturing step of manufacturing an intermediate body in which a plurality of magnet bodies are positioned on the same surface of a sheet material; The sheet material is placed between a first mold made of a material and a second mold facing the first mold so that the surface of the sheet material opposite to the magnet main body faces the first mold. and a cutting step of cutting the sheet material between the magnet bodies arranged adjacent to each other by sandwiching the intermediate between the first mold and the second mold. have

In the above configuration, in the cutting step, the first die elastically deforms so as to extend in the lateral direction and also elastically deforms so as to enter between adjacent magnet bodies. As a result, forces acting in directions away from each other act on adjacent magnet bodies. In addition, the force from the elastically deformed first die tends to concentrate on the edge of each magnet body. As a result, the sheet material is cut between adjacent magnet bodies. This cutting of the sheet material occurs at various locations on adjacent magnet bodies during the cutting process. Therefore, the sheet material can be efficiently cut.

In the method for manufacturing a magnet, the magnet body has a planar first surface and a planar second surface adjacent to the first surface, and in the intermediate manufacturing step, the first surface is the A plurality of the magnet bodies may be arranged on the same surface of the sheet material so as to contact the sheet material.

According to the above configuration, when the first mold is pressed against the intermediate body, the first mold tends to apply force to the boundary between the first surface and the second surface of the magnet body. Therefore, it becomes easier to cut the sheet material at the boundary.

In the magnet manufacturing method, the surface of the first mold facing the sheet material has a planar flat surface and a protruding surface protruding from the flat surface, and in the arranging step, the magnet main body , The intermediate body may be arranged such that a boundary between the first surface and the second surface faces the projecting surface with the sheet material interposed therebetween.

According to the above configuration, when the first die is pressed against the intermediate body, force is likely to act on the sheet material from the projecting surface of the first die. Specifically, a very strong force is applied to the portion of the sheet material sandwiched between the projecting surface of the first die and the boundary between the first surface and the second surface of the magnet body. Therefore, the sheet material can be cut more reliably at this portion.

In the method for manufacturing a magnet, the sheet material contains thermoplastic resin fibers and inorganic fibers, and in the intermediate preparation step, the sheet material is heated to a temperature equal to or higher than the glass transition temperature of the thermoplastic resin fibers and pressed. Thus, the sheet material may be thermocompression bonded to the plurality of magnet bodies while the inorganic fibers are elastically compressed.

When a sheet material containing thermoplastic resin fibers and inorganic fibers is thermocompressed to a magnet body and then heated again, the thermoplastic resin fibers in the sheet material are softened again, and the elastically compressed inorganic fibers are restored to their original state. The action expands the sheet material. Using this characteristic, the magnet can be fixed to the rotor core by disposing the magnet, which is formed by thermally compressing the sheet material to the magnet main body, in the slot of the rotor core and expanding the sheet material.

In the above configuration, the sheet material is thermocompression bonded to the plurality of magnet bodies in the intermediate body manufacturing process. As a result, in the cutting step, a plurality of magnets can be produced by thermocompression bonding the sheet material to the magnet body. The magnets can be secured to the rotor core simply by placing these magnets in the slots of the rotor core and heating them. Thus, according to the above configuration, the rotor can be manufactured very efficiently.

A method for manufacturing a rotor for solving the above-mentioned problems is a sheet material containing a thermoplastic resin fiber and an inorganic fiber, in which a plurality of magnet bodies are positioned on the same surface of the sheet material. An intermediate body producing step of producing an intermediate body in which the sheet material is thermocompressed to a plurality of the magnet bodies in a state where the inorganic fibers are elastically compressed by applying pressure while heating to a temperature or higher, and Between a first mold made of an elastic material having a small elastic modulus and a second mold facing the first mold, the surface of the sheet material opposite to the magnet main body is positioned as the first mold. An arrangement step of arranging the intermediate body so as to face the first mold, and sandwiching the intermediate body between the first mold and the second mold, thereby placing the sheet material between the magnet bodies arranged adjacent to each other. A cutting step of cutting to produce a magnet in which the magnet main body is covered with the sheet material, and heating the magnet to the glass transition temperature or higher in a state where the magnet is placed in a slot in a rotor core. and a fixing step of elastically returning the inorganic fibers to fix the magnets to the rotor core.

When a sheet material containing thermoplastic resin fibers and inorganic fibers is thermocompressed to a magnet body and then heated again, the thermoplastic resin fibers in the sheet material are softened again, and the elastically compressed inorganic fibers are restored to their original state. The action expands the sheet material. In the above configuration, this characteristic is utilized to fix the magnets to the rotor core by expanding the sheet material thermocompressed to the magnet main body in the slots of the rotor core. In order to fix the magnets to the rotor core in this manner, in the above configuration, an intermediate body is prepared in advance by thermally compressing a sheet material to a plurality of magnet bodies. Then, the intermediate body is sandwiched between the first die and the second die to cut the intermediate body between adjacent magnet bodies. When the intermediate body is sandwiched between the first die and the second die and the first die is pressed against the intermediate body, the first die elastically deforms so as to extend in the lateral direction and also elastically enters between adjacent magnet bodies. transform. As a result, forces acting in directions away from each other act on adjacent magnet bodies. In addition, the force from the elastically deformed first die tends to concentrate on the edge of each magnet body. As a result, the sheet material is cut between adjacent magnet bodies. This cutting of the sheet material occurs at various locations on adjacent magnet bodies during the cutting process. Therefore, the sheet material can be efficiently cut.

Sectional drawing of a motor. The top view of a rotor. A perspective view of a magnet. 4 is a flow chart showing a manufacturing process of the rotor; Explanatory drawing of an intermediate production process. Explanatory drawing of an intermediate production process. Explanatory drawing of an arrangement|positioning process. Explanatory drawing of a cutting process. Explanatory drawing of an insertion process. Explanatory drawing of a fixing process. The figure showing the example of a change of a cutting device. The figure showing the example of a change of a cutting device. The figure showing the example of a change of an intermediate production process.

An embodiment of a magnet manufacturing method and a rotor manufacturing method will be described below with reference to the drawings.
<Overall Configuration of Motor>
First, a schematic configuration of the motor will be described.

As shown in FIG. 1, motor 50 has stator 70 , rotor 60 and shaft 55 .
Stator 70 is generally cylindrical. The stator 70 has a stator core 72 and coils 76 . Furthermore, the stator core 72 has a main body of the stator core 72 (hereinafter referred to as a stator core main body) 72A and a plurality of teeth 72B. The stator core body 72A is cylindrical. The plurality of teeth 72B protrude from the inner peripheral surface of the stator core body 72A toward the center axis J of the stator core body 72A. The plurality of teeth 72B are arranged circumferentially at regular intervals. In FIG. 1, the boundary between the stator core body 72A and the teeth 72B is indicated by a two-dot chain line.

A coil 76 is wound around each tooth 72B. The coil 76 extends outside both ends of the stator core body 72A in the direction along the central axis J of the stator core body 72A. That is, the coil 76 protrudes from the stator core 72 in the direction along the center axis J of the stator core body 72A. In this specification, the reference numeral J is given to those coaxial with the central axis J of the stator core body 72A.

The rotor 60 is cylindrical. The rotor 60 is positioned inside the stator core body 72A. The central axis J of the rotor 60 coincides with the central axis J of the stator core body 72A. There is a gap between the outer peripheral surface of rotor 60 and the projecting end of each tooth 72B in stator 70 . In FIG. 1, illustration of this gap is omitted. Details of the rotor 60 will be described later. Rotor 60 is rotatable with respect to stator 70 .

The shaft 55 is cylindrical. Shaft 55 passes through a central hole in rotor 60 . A central axis J of the shaft 55 coincides with a central axis J of the rotor 60 . The shaft 55 rotates integrally with the rotor 60 .

<Rotor configuration>
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 illustration is omitted, the rotor core 62 is formed by laminating a plurality of electromagnetic steel sheets processed into an annular shape in a direction along the central axis J thereof.

A plurality of slots 64 are provided 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 thereof. As shown in FIG. 2 , the plurality of slots 64 are located near the outer circumference of the rotor core 62 . The multiple slots 64 are arranged in the circumferential direction of the rotor core 62 .

As shown in FIG. 2 , the slot 64 has a substantially rectangular shape when viewed from above along the central axis J of the rotor core 62 . A total of eight pairs of slots 64 are provided, with slots 64 adjacent in the circumferential direction forming a pair. In a plan view along the central axis J of the rotor core 62, the paired two slots 64 are arranged in a V shape. Specifically, the two slots 64 that form a pair are closer to each other as they are located closer to the inner circumference of the rotor core 62 .

A plurality of magnets 80 are positioned within each slot 64 . That is, there is one magnet 80 per slot 64 . Each magnet 80 has a main body 82 of the magnet 80 (hereinafter referred to as magnet main body) and two sheets 86 .

The magnet main body 82 is composed of a permanent magnet. In this embodiment, the magnet body 82 is a neodymium magnet made from iron, neodymium, boron, or the like. As shown in FIG. 3, the magnet body 82 has a rectangular plate shape. Specifically, the magnet body 82 has two first surfaces 82A, two second surfaces 82B, and two third surfaces 82C. 82 A of 1st surfaces are the surfaces with the largest area among the outer surfaces of the magnet main body 82. As shown in FIG. The first surface 82A is rectangular. The first surface 82A is flat and not curved. The two first surfaces 82A are in a parallel positional relationship. The second surface 82B connects the long sides of the two first surfaces 82A. That is, the second surface 82B is adjacent to the first surface 82A. The second surface 82B is flat and not curved. The first surface 82A and the second surface 82B are substantially orthogonal. That is, the boundary 82S between the first surface 82A and the second surface 82B is angular. The third surface 82C connects the short sides of the two first surfaces 82A. That is, the third surface 82C is adjacent to the first surface 82A. The third surface 82C is flat and not curved. The first surface 82A and the third surface 82C are substantially orthogonal. That is, the boundary 82T between the first surface 82A and the third surface 82C is angular.

The sheet material 86 is a non-woven fabric made from fibers of polyetherimide, which are thermoplastic resin fibers, and glass fibers, which are inorganic fibers. The two sheet materials 86 cover the two first surfaces 82A of the magnet body 82, respectively. The two sheet materials 86 constitute an insulating layer. It should be noted that the thickness of the sheet material 86 is exaggerated and enlarged in each of the drawings.

The shape and size of magnet 80 is generally the same as the shape and size of slot 64 . As shown in FIG. 2 , the direction along the short side of the rectangular slot 64 in plan view along the center axis J of the rotor core 62 is referred to as the width direction of the slot 64 . As shown in FIG. 1 , when the magnet 80 is fixed to the slot 64 , the two sheet members 86 of the magnet 80 are in contact with the inner surfaces of the slot 64 on both sides in the width direction. In addition, the positions of both ends of the magnet 80 coincide with the positions of both ends of the slot 64 with respect to the direction along the central axis J of the rotor core 62 . In addition, as shown in FIG. 2 , gaps exist between the magnets 80 and the inner surfaces of the slots 64 on both sides in the longitudinal direction in plan view from the direction along the central axis J of the rotor core 62 .

As shown in FIG. 2, a pair of magnets 80 arranged in two pairs of slots 64 constitute each magnetic pole of the motor 50 . That is, the radially outer surfaces of the rotor 60 in the pair of magnets 80 arranged in the two slots 64 forming a pair are magnetized with the same polarity. The pair of magnets 80 constitute magnetic poles of north poles or south poles. Also, the polarities of the pair of magnets 80 and the pair of magnets 80 positioned next to them are reversed. As a result, in the rotor 60, N poles and S poles are alternately arranged in the circumferential direction.

<Intermediate manufacturing equipment>
An intermediate manufacturing apparatus 200 used when manufacturing the magnet 80 described above will be described. Although the following description is based on the top and bottom of the drawing, it is not necessary that the top and bottom of the drawing match the actual top and bottom.

As shown in FIG. 6, the intermediate manufacturing device 200 is a press die device. The intermediate manufacturing apparatus 200 has a first pressure mold 201 and a second pressure mold 202 . The first pressurizing mold 201 has a substantially rectangular parallelepiped shape. The first pressure mold 201 is made of copper. The reason why copper is used as the material for the first pressing die 201 is that it has a high thermal conductivity. The shape and material of the second pressure mold 202 are the same as those of the first pressure mold 201 . The second pressure mold 202 is positioned above the first pressure mold 201 . The upper surface of the first pressure mold 201 and the lower surface of the second pressure mold 202 face each other. The second pressurizing die 202 approaches or separates from the first pressurizing die 201 by being driven by a servomotor.

The first pressure mold 201 has a first concave portion 201A. The first concave portion 201A is recessed on the upper surface of the first pressure mold 201 . The first recess 201A has a rectangular shape when the first pressure mold 201 is viewed from above. The long side and short side dimensions of the first recess 201A when the first pressure mold 201 is viewed from above are larger than the long side and short side dimensions of the sheet material 86 prepared in the preparation step S10 described later. The recess depth of the first recess 201A is less than half the thickness of the magnet body 82 . The second pressure mold 202 has a second recess 202A similar to the first recess 201A of the first pressure mold 201 . The second recess 202A is recessed on the lower surface of the second pressure mold 202. As shown in FIG.

The intermediate manufacturing apparatus 200 has two heaters H, two cooling water passages W, two temperature sensors T, and a load sensor 204 . One heater H is located inside the first pressure mold 201 . The other heater H is positioned inside the second pressure mold 202 . Each heater H can adjust the temperature of each of the first pressure mold 201 and the second pressure mold 202 . One cooling water passage W is a space defined inside the first pressurizing mold 201 . The other cooling water passage W is a space defined inside the second pressurizing mold 202 . Although not shown, there is a switching mechanism outside the first pressurizing die 201 and the second pressurizing die 202 that permits or prohibits the cooling water from flowing through the two cooling water passages W. As shown in FIG. One temperature sensor 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 pressurizing die 202 . Each temperature sensor T is composed of, for example, a thermocouple. The load sensor 204 detects the force applied to the object sandwiched between the first pressure die 201 and the second pressure die 202 when the second pressure die 202 is brought closer to the first pressure die 201 . The load sensor 204 is composed of, for example, a load cell. In addition, in FIG. 6, the load sensor 204 is illustrated on the side surface of the first pressing die 201 for convenience.

<Cutting device>
A cutting device 300 used when manufacturing the magnet 80 will be described.
As shown in FIG. 7, the cutting device 300 has a first base member 301 and a second base member 302. As shown in FIG. The first base member 301 has a substantially rectangular parallelepiped shape. 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 positioned above the first base member 301 . The second base member 302 approaches or separates from the first base member 301 by being driven by a servomotor.

The cutting device 300 has a first die 303 and a second die 304 . The first mold 303 has a substantially rectangular parallelepiped shape. The first mold 303 is made of elastic material. Specifically, the material of the first mold 303 is a thermosetting elastomer, that is, rubber. The modulus of elasticity of the first mold 303 is smaller than that of the magnet body 82 . Shore hardness of the first mold 303 is about 70 to 90 HS. Shore hardness is an index that indicates the hardness of an object. The higher the Shore hardness, the harder the object. The shape, material, elastic modulus, and Shore hardness of the second mold 304 are the same as those of the first mold 303 .

A first die 303 and a second die 304 are positioned between the first base member 301 and the second base member 302 . Specifically, the first mold 303 is positioned on the upper surface of the first base member 301 . The first mold 303 is fixed to the top surface of the first base member 301 . The second mold 304 is located on the bottom surface of the second base member 302 . The second mold 304 is fixed to the bottom surface of the second base member 302 . The bottom surface of the second mold 304 faces the top surface of the first mold 303 . Both the lower surface of the second mold 304 and the upper surface of the first mold 303 are flat and not curved. The second mold 304 operates integrally with the second base member 302 . That is, when the second base member 302 approaches or separates from the first base member 301 , the second die 304 approaches or separates from the first die 303 .

<Manufacturing method of magnet and rotor>
A method of manufacturing the magnet 80 and the rotor 60 will be described. As shown in FIG. 4, the method for manufacturing the rotor 60 includes a preparation step S10, an intermediate body preparation step S20, an arrangement step S30, a cutting step S40, an insertion step S50, and a fixing step S60. Of these six steps, the magnet 80 is manufactured through the steps from the preparation step S10 to the cutting step S40. That is, the method for manufacturing the magnet 80 has steps from the preparation step S10 to the cutting step S40.

When manufacturing the rotor 60, a preparatory step S10 is first performed. In the preparation step S10, the rotor core 62, the magnet body 82, and the sheet material 86 are prepared. As for the rotor core 62 and the magnet body 82, those having the shapes already described are prepared. Sixteen magnet bodies 82 are prepared for each rotor core 62 in accordance with the number of slots 64 in the rotor core 62 . Two sheet materials 86 are prepared for one rotor core 62 . The sheet material 86 has a rectangular shape. As shown in FIG. 5, the dimension of the short side Y1 of the sheet material 86 is longer than the dimension of the long side of the first surface 82A of the magnet body 82. As shown in FIG. The dimension of the long side Y2 of the sheet material 86 is longer than 32 times the dimension of the short side of the first surface 82A of the magnet body 82 . In the following description, the two sheet materials 86 will be referred to as the first sheet material 86A and the second sheet material 86B when they are individually described, and the sheet materials 86 when collectively described. called.

<Intermediate production process>
As shown in FIG. 4, after the preparation step S10, an intermediate production step S20 is performed. The intermediate production step S<b>20 is a step of producing the intermediate 88 using the intermediate production apparatus 200 . At the start of the intermediate production step S20, the second pressure mold 202 of the intermediate production apparatus 200 is stopped at the initial position. The initial position is a position where the second pressure mold 202 is considerably separated from the first pressure mold 201 .

As indicated by an arrow U1 in FIG. 5, in the intermediate manufacturing step S20, first, the first sheet material 86A is placed in the first concave portion 201A of the first pressure mold 201 in the intermediate manufacturing apparatus 200 by, for example, a robot hand. Then, as indicated by arrow U2 in FIG. 5, 16 magnet bodies 82 are arranged on the first sheet member 86A. When arranging each magnet body 82 on the first sheet material 86A, the first surface 82A of each magnet body 82 faces the first sheet material 86A. Also, the long side of the first surface 82A of each magnet body 82 and the short side Y1 of the first sheet material 86A are made parallel. In this case, the second surfaces 82B of the adjacent magnet bodies 82 face each other. In this state, 16 magnet bodies 82 are arranged in a line with a space therebetween. The gap between the adjacent magnet bodies 82 is made shorter than the dimension of the short side of the first surface 82A of the magnet bodies 82 . After that, the second sheet material 86B is arranged on the 16 magnet bodies 82 as indicated by the arrow U3 in FIG. At this time, the four sides of the second sheet material 86B are aligned with the four sides of the first sheet material 86A. In this way, the upper and lower first surfaces 82A of the magnet bodies 82 are covered with the two sheet materials 86. As shown in FIG. When the second sheet material 86B is viewed from above, the second sheet material 86B protrudes from the 16 magnet main bodies 82 . That is, the first sheet material 86A also protrudes from the 16 magnet main bodies 82. As shown in FIG.

After that, the intermediate manufacturing apparatus 200 is driven. Then, the second pressure mold 202 approaches the first pressure mold 201 as indicated by arrow A in FIG. The two sheet members 86 and the 16 magnet bodies 82 are sandwiched between the bottom surface of the recess in the first recess 201A of the first pressure mold 201 and the bottom surface of the recess in the second recess 202A of the second pressure mold 202. At this time, the first sheet member 86A is sandwiched between the bottom surface of the first concave portion 201A and the first surface 82A of each magnet main body 82. As shown in FIG. The second sheet member 86B is similarly sandwiched between the bottom surface of the second concave portion 202A and the first surface 82A of each magnet body 82. As shown in FIG. The second pressure die 202 stops operating at a position where the force applied to the two sheet materials 86 becomes the specified load N. As shown in FIG. It should be noted that the force applied to the two sheet materials 86 can be grasped from the detection value of the load sensor 204 . The specified load N is set in advance by experiment, for example, as a magnitude equal to or greater than the minimum load required to elastically compress the glass fibers of the sheet material 86 and less than the minimum load at which the glass fibers break. There is. In FIG. 6, dots are added to the first sheet material 86A and the second sheet material 86B in order to clearly represent the two sheet materials 86. As shown in FIG.

After that, the heater H heats the first pressure mold 201 and the second pressure mold 202 . Then, the temperature of the first concave portion 201A of the first pressing die 201 is set to the first specified temperature Z1. Also, the temperature of the second recess 202A of the second pressure mold 202 is set to the first specified temperature Z1. The temperature of each recess 201A, 202A can be grasped from the detection value of the temperature sensor T. FIG. The first specified temperature Z1 is set in advance as a temperature higher than the glass transition temperature of the polyetherimide forming the sheet material 86 and lower than the temperature at which the polyetherimide evaporates. In this embodiment, the first specified temperature Z1 is set as a temperature slightly higher than the glass transition temperature of polyetherimide.

The state in which the two sheet materials 86 are heated and pressed as described above is maintained for the first specified period L1. The first specified period L1 is the length of time required for the polyetherimide to soften sufficiently to elastically compress the glass fibers of the sheet material 86 when the sheet material 86 is at the first specified temperature Z1. It is determined in advance by experiment, for example.

After that, the temperatures of the first pressure mold 201 and the second pressure mold 202 are lowered while the pressure on the two sheet materials 86 is maintained. For example, the temperature of heating by the heater H is lowered, or the cooling water is supplied to the cooling water passage W. Then, the temperature of the first concave portion 201A of the first pressing die 201 is set to the second specified temperature Z2. Also, the temperature of the second recess 202A of the second pressure mold 202 is set to the second specified temperature Z2. The second specified temperature Z2 is predetermined as a temperature lower than the glass transition temperature of polyetherimide. In this embodiment, the second specified temperature Z2 is set as a temperature slightly lower than the glass transition temperature of polyetherimide.

After that, the state in which the first recess 201A of the first pressure mold 201 and the second recess 202A of the second pressure mold 202 are lowered to the second specified temperature Z2 while maintaining the pressurization of the two sheet materials 86 is 2 L2 is maintained for a specified period. The second specified period L2 is predetermined, for example, by experiments as the length of time required for the polyetherimide of the sheet material 86 to solidify when the sheet material 86 is at the second specified temperature Z2.

After the second specified period L2 has passed, the second pressing die 202 is returned to the initial position. Then, in the first concave portion 201A of the first pressure mold 201, an intermediate body 88 is formed by thermocompression bonding the sheet material 86 to the upper and lower first surfaces 82A of each magnet body 82, respectively. At this point, the inorganic fibers of the two sheet materials 86 are in an elastically compressed state. The series of steps described above is the intermediate production step S20. As described above, the intermediate body 88 is obtained by covering the two first surfaces 82A of each magnet body 82 with the sheet material 86, respectively. In other words, in the intermediate body 88, one first surface 82A of each magnet main body 82 is positioned on the same surface of the first sheet material 86A, and each magnet main body 82 is positioned on the same surface of the second sheet material 86B. The other first surface 82A of is located.

<Placement process>
As shown in FIG. 4, an arrangement step S30 is performed after the intermediate production step S20. The placement step S<b>30 is a step of placing the intermediate 88 in the cutting device 300 . It should be noted that the second base member 302 and the second die 304 of the cutting device 300 are stopped at the initial positions at the start of the placement step S30. The initial position is a position where the second die 304 is considerably separated from the first die 303 . In this state, the intermediate 88 is placed on the upper surface of the first die 303 as shown in FIG. 7 by, for example, a robot hand. At this time, the first sheet member 86A faces the upper surface of the first die 303. As shown in FIG. That is, the surface of the first sheet member 86A opposite to the first surface 82A of the magnet main body 82 faces the upper surface of the first die 303. As shown in FIG. The surface of the second sheet member 86B opposite to the first surface 82A of the magnet main body 82 faces the lower surface of the second die 304. As shown in FIG. As in FIG. 6, in FIG. 7 dots are added to the first sheet material 86A and the second sheet material 86B.

<Cutting process>
As shown in FIG. 4, the cutting step S40 is performed after the arranging step S30. The cutting step S40 is a step of cutting the two sheet materials 86 in the intermediate body 88 . In the cutting step S40, the cutting device 300 is driven. Then, the second mold 304 approaches the first mold 303 together with the second base member 302, as indicated by arrow B in FIG. Then, the first die 303 and the second die 304 sandwich the intermediate body 88 . When the second die 304 moves to the predetermined approach position Q, the second base member 302 and the second die 304 stop moving. Then, it waits for the waiting period M in this state. The waiting period M is, for example, 5 seconds. During this waiting period M, two sheets 86 are cut for each magnet body 82 . That is, the two sheet materials 86 are cut between adjacent magnet bodies 82 or cut along the long side or short side of the first surface 82A of each magnet body 82 . The mechanism by which the sheet material 86 is cut will be described later in the section of action. Note that the above approach position Q is determined in advance, for example, by experiment as a position at which the force required to cut the sheet material 86 is applied to the intermediate body 88 . Further, the waiting period M is determined in advance by experiment, for example, as the length of time required until the cutting of the sheet material 86 is completed while the second die 304 is stopped at the approach position Q. As shown in FIG. As in FIG. 7, in FIG. 8 dots are added to the first sheet material 86A and the second sheet material 86B.

After that, the second mold 304 is returned to the initial position together with the second base member 302 . Then, 16 magnets 80 and a scrap of sheet material 86 are formed on the upper surface of the first die 303 . The magnet 80 is obtained by covering two first surfaces 82A of a magnet main body 82 with sheet materials 86, respectively.

<Insertion process>
As shown in FIG. 4, the inserting step S50 is performed after the cutting step S40. The inserting step S<b>50 is a step of inserting the magnets 80 into the slots 64 of the rotor core 62 . As shown in FIG. 9, in the inserting step S50, for example, a disc-shaped support board 400 is arranged substantially horizontally. Then, the rotor core 62 is arranged on the support plate 400 . At this time, one of the two openings in each slot 64 faces the support plate 400 and the other faces upward. Then, as indicated by arrow C in FIG. 9, the magnets 80 are inserted into the slots 64 of the rotor core 62 on the support plate 400 by, for example, a robot hand.

At the stage where the magnet 80 is produced by the cutting step S40, the sheet material 86 of the magnet 80 is in a state of being compressed by thermocompression bonding. Therefore, the thickness of the magnet 80 including the sheet material 86 is smaller than the dimension of the slot 64 in the rotor core 62 in the width direction. Therefore, when inserting the magnet 80 into the slot 64 in the inserting step S50, the magnet 80 moves into the slot 64 quickly.

<Fixation process>
As shown in FIG. 4, the fixing step S60 is performed after the inserting step S50. The fixing step S<b>60 is a step of fixing the magnets 80 to the rotor core 62 . As shown in FIG. 10, in the fixing step S60, a temperature-adjustable furnace 500 is used. Specifically, in the fixing step S60, the rotor core 62 with the magnets 80 inserted into the respective slots 64 is placed in the furnace 500 together with the support plate 400 . Then, the rotor core 62 is heated within the furnace 500 . At that time, the temperature inside the furnace 500 is adjusted to the third specified temperature Z3. The third specified temperature Z3 is predetermined as a temperature higher than the glass transition temperature of the polyetherimide forming the sheet material 86 and lower than the temperature at which the polyetherimide vaporizes. In this embodiment, the third specified temperature Z3 is set as the same temperature as the first specified temperature Z1.

Heating of the rotor core 62 in the furnace 500 continues for the third prescribed period L3. The third specified period L3 is the length of time required for the polyetherimide to soften sufficiently for the glass fibers of the sheet material 86 to elastically recover when the sheet material 86 is at the third specified temperature Z3. is determined in advance by experiment or the like. After heating the rotor core 62 for the third prescribed period L3, the rotor core 62 is taken out from the furnace 500 . After that, the rotor core 62 is returned to room temperature. Thus, the rotor 60 is completed.

<Action of Embodiment>
(b) Mechanism for Fixing Magnets to Slots As shown in FIG. 6, in the intermediate manufacturing step S20, the first recess 201A of the first pressure mold 201 and the second recess 202A of the second pressure mold 202 are made of polyetherimide. is heated to a temperature above the glass transition temperature of Along with this, the polyetherimide of the sheet material 86 positioned on the first surface 82A of each magnet body 82 is softened. In addition, in the intermediate production step S20, the sheet material 86 is pressurized. As a result, the glass fibers of the sheet material 86 are bent and elastically compressed. Further, in the intermediate manufacturing step S20, the first recess 201A of the first pressure mold 201 and the second recess 202A of the second pressure mold 202 are placed at the glass transition temperature of polyetherimide while the sheet material 86 is kept pressed. Cool to a lower temperature than As a result, the sheet material 86 is joined to the first surface 82A of each magnet body 82 while the glass fibers are elastically compressed.

Due to the above reason, the sheet material 86 of each magnet 80 produced in the cutting step S40 is elastically compressed. In the fixing step S60, such sheet material 86 is reheated to a temperature higher than the glass transition temperature of polyetherimide. Along with this, the polyetherimide of the sheet material 86 softens again. Then, the elastically compressed glass fibers are elastically restored. Accordingly, as indicated by arrow D in FIG. 10, the sheet material 86 expands from the position where the glass fibers indicated by the two-dot chain line in FIG. 10 were elastically compressed. When the sheet material 86 expands and reaches the inner surface of the slot 64 , the sheet material 86 and the inner surface of the slot 64 come into contact with each other, causing friction to fix the magnet 80 in the slot 64 .

(b) Mechanism for Cutting Sheet Material As shown in FIG. 8, in the cutting step S40, the intermediate 88 is sandwiched between the first mold 303 and the second mold 304. As shown in FIG. That is, the first die 303 and the second die 304 are pressed against the intermediate body 88 . The sheet material 86 is cut with the elastic deformation of the first die 303 and the second die 304 at this time. In the following, the relation between the elastic deformation of the first die 303 and the cutting of the sheet material 86 will be described by taking the first die 303 as an example.

As shown in FIG. 8, when the first mold 303 is pressed against the first sheet material 86A, the first mold 303 is crushed by the first base member 301 and the first surface 82A of the magnet body 82 from above and below. As a result, the portion of the first die 303 immediately below the first surface 82A of the magnet main body 82 is elastically deformed so as to extend in the lateral direction, as indicated by arrow B1 in FIG. While the first mold 303 deforms in the lateral direction in this manner, it also elastically deforms so as to enter between adjacent magnet bodies 82 as indicated by arrow B2 in FIG. The first mold 303 that enters between the adjacent magnet bodies 82 while deforming in the lateral direction tries to widen the area between the adjacent magnet bodies 82 in the lateral direction. In other words, forces acting in directions away from each other act on the adjacent magnet bodies 82 . This increases the distance between adjacent magnet bodies 82 . As a result, a large tension is applied to the portion of the first sheet material 86A between the adjacent magnet bodies 82, and the first sheet material 86A is cut.

Also, the sheet material 86 can be cut depending on the shape of the magnet main body 82 . A boundary 82S between the first surface 82A and the second surface 82B of the magnet body 82 is angular. A boundary 82T between the first surface 82A and the third surface 82C of the magnet body 82 is also angular. Therefore, when the first die 303 is pressed against the intermediate body 88 , force is likely to be applied from the first die 303 to the boundaries 82 S and 82 T of the magnet main body 82 . As a result, the first sheet material 86A facing the first die 303 is cut at the portions in contact with the boundaries 82S and 82T.

Although the first die 303 and the first sheet material 86A have been described above as an example, the same can be said for the second die 304 and the second sheet material 86B.
It should be noted that there are places where the sheet material 86 is cut at various places on the intermediate body 88 only because the distance between the adjacent magnet bodies 82 is long, and the sheet material 86 is cut only because of contact with the corners of the magnet bodies 82 . There are places where it can be cut. Also, there are places where the sheet material 86 is torn due to the folding of both mechanisms. That is, the sheet material 86 is cut at the corners of the magnet bodies 82 in a state where a large tension is applied to the sheet material 86 due to the increased distance between the adjacent magnet bodies 82 .

<Effects of Embodiment>
(1) As described in the above operation, when the first die 303 and the second die 304 are pressed against the intermediate body 88 in the cutting step S40, the first die 303 and the second die 304 are elastically deformed so as to extend in the lateral direction. At the same time, it is elastically deformed so as to enter between adjacent magnet bodies 82 . As a result, forces acting in directions away from each other act on the adjacent magnet bodies 82 . As a result, the sheet material 86 is cut between adjacent magnet bodies 82 . Such cutting of the sheet material 86 occurs at various locations of the adjacent magnet bodies 82 . Therefore, the sheet material 86 can be cut efficiently.

(2) As described in the above operation, when the first mold 303 and the second mold 304 are pressed against the intermediate body 88, the boundary 82S between the first surface 82A and the second surface 82B in the magnet body 82 and the first surface Force is likely to be applied from the first die 303 and the second die 304 to the boundary 82T between 82A and the third surface 82C. Therefore, the sheet material 86 can be cut at these boundaries 82S and 82T. Moreover, when the sheet material 86 is cut at the boundary between the surfaces of the magnet body 82 in this manner, the sheet material 86 can be cut along the outer edge of the magnet body 82 . Therefore, the magnet 80 can be manufactured with a small amount of extra parts protruding from the magnet main body 82 .

(3) As described in the above operation, the sheet material 86 containing thermoplastic resin fibers and inorganic fibers is thermocompression bonded to the magnet body 82, and then heated again, so that the thermoplastic resin fibers in the sheet material 86 are softened again. Then, the elastically compressed inorganic fibers return to their original state, and the sheet material 86 expands. In the fixing step S<b>60 , using this characteristic, the sheet material 86 thermocompressed to the magnet body 82 is expanded within the slot 64 of the rotor core 62 , thereby fixing the magnet 80 to the rotor core 62 . In order to fix the magnets 80 to the rotor core 62 in this way, in the present embodiment, the sheet material 86 is thermo-compressed to the 16 magnet bodies 82 in the intermediate production step S20. As a result, in the cutting step S40, 16 magnets 80 in which the sheet material 86 is thermocompression bonded to the magnet body 82 can be produced. That is, the sheet material 86 is already thermocompression-bonded to the magnet main body 82 when the cutting step S40 is finished. Therefore, in the fixing step S<b>60 , the magnets 80 can be fixed to the rotor core 62 simply by heating these 16 magnets 80 in the slots 64 of the rotor core 62 . Therefore, by using the method of manufacturing the rotor 60 of the present embodiment, the rotor 60 can be manufactured very efficiently.

In addition, this embodiment can be changed and implemented as follows. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
- The configuration of the cutting device 300 used in the cutting step S40 is not limited to the example of the above embodiment. The cutting device 300 may be configured to cut the sheet material 86 when the intermediate body 88 is sandwiched between the first die 303 and the second die 304 . For example, like the cutting device 350 shown in FIG. 11, the upper surface of the first mold 353 may have a planar flat surface 353P and a projecting surface 353B projecting from the flat surface 353P. Specifically, a plurality of convex portions 353A protrude from the flat surface 353P of the first die 353. As shown in FIG. The surface of the convex portion 353A is the projecting surface 353B. The plurality of protrusions 353A are arranged in a row at regular intervals. Specifically, the plurality of protrusions 353A are provided for each short side dimension of the first surface 82A of the magnet body 82 . A protruding end of each convex portion 353A is planar. That is, part of the projecting surface 353B is planar. Similarly, from the flat surface 354P of the second mold 354, a plurality of protrusions 354A protrude. The surface of the convex portion 354A is a protruding surface 354B. Each convex portion 354A of the second mold 354 is present at a position facing each convex portion 353A of the first mold 353. As shown in FIG.

When the cutting device 350 as described above is used, the intermediate bodies 88 are manufactured in a state in which there are not many gaps between the magnet main bodies 82 in the intermediate body manufacturing step S20. Then, in the placement step S30, the boundary 82S between the downward facing first surface 82A and the second surface 82B of the magnet body 82 faces the projecting surface 353B of the first die 353 with the first sheet member 86A interposed therebetween. to When the intermediate body 88 is arranged in this way, the boundary 82S between the upward facing first surface 82A and the second surface 82B of the magnet body 82 faces the projecting surface 354B of the second mold 354. As shown in FIG. Cutting process S40 is performed under such arrangement|positioning.

When the first mold 353 is provided with the convex portion 353A on the upper surface thereof as described above, when the first mold 353 is pressed against the intermediate body 88, the first mold 353 moves from the projecting surface 353B of the first mold 353 to the first sheet. A force is likely to act on the material 86A. Specifically, a very strong force is applied to the portion of the first sheet member 86A sandwiched between the protruding surface 353B of the first die 353 and the boundary 82S of the magnet body 82 . Therefore, the first sheet material 86A can be cut more reliably at this portion. The same can be said for the second sheet material 86B. 11, illustration of the first base member 301 and the second base member 302 is omitted. 11, like FIG. 7, dots are added to the first sheet material 86A and the second sheet material 86B.

- Like the cutting device 370 shown in FIG. That is, on the upper surface of the first die 373, continuous unevenness is irregularly present. For example, when the upper surface of the first mold 303 is planar as in the above embodiment, the force applied from the upper surface of the first mold 303 to the intermediate body 88 is substantially uniform at various locations on the upper surface of the first mold 303. . On the other hand, when the upper surface of the first mold 373 is irregularly provided with a plurality of protrusions, the force applied from the upper surface of the first mold 373 to the intermediate body 88 differs at various locations on the upper surface of the first mold 373 . Depending on the location, a strong force is locally applied to the intermediate body 88 . For example, the first mold 373 is elastically deformed irregularly between the first base member 301 and each magnet main body 82 due to the presence of such a plurality of locations where a strong force is applied locally. can act to move adjacent magnet bodies 82 apart. This allows the sheet material 86 to be cut. Also, if a strong force is locally applied to the boundary 82S between the first surface 82A and the second surface 82B of the magnet body 82, the sheet material 86 can be cut at the boundary. As with the first die 373 , unevenness may be provided irregularly on the lower surface of the second die 374 . 12, illustration of the first base member 301 and the second base member 302 is omitted. 12, like FIG. 7, dots are added to the first sheet material 86A and the second sheet material 86B.

- The Shore hardness of the first die 303 is not limited to the example of the above embodiment. If the Shore hardness of the first die 303 is high, the sheet material 86 can be cut even if the force pressing the first die 303 against the intermediate body 88 is small. If the force for pressing the first die 303 against the intermediate body 88 is small, the first die 303 is less likely to be burdened, which is advantageous in terms of the durability of the first die 303 . In consideration of the durability of the first die 303, an appropriate Shore hardness may be set in consideration of, for example, cost. The same applies to the Shore hardness of the second die 304 . The first mold 303 and the second mold 304 may have different Shore hardnesses.

- The first mold 303 and the second mold 304 may have different moduli of elasticity. The modulus of elasticity of the first mold 303 should be smaller than that of the magnet main body 82 . The same applies to the second mold 304 as well.

- The material of the first die 303 is not limited to the example of the above embodiment. The first mold 303 may be made of an elastic material. The material of the first mold 303 may be thermoplastic elastomer, for example. The same applies to the second mold 304 as well. The materials of the first mold 303 and the second mold 304 may be different from each other.

- When only one sheet material 86 is used to form the intermediate body 88, as in the modification described later, the first die 303 may be made of an elastic material, and the second die 304 may not be made of an elastic material. good too. In this case, the sheet material 86 may face the first mold 303 in the placement step S30.

- With respect to the arrangement of the first mold 303 and the second mold 304, they may be arranged by changing the top and bottom of the aspect of the above embodiment. That is, the first die 303 may be positioned above the second die 304 .

- The first die 303 and the second die 304 may be arranged side by side in the direction of gravity, or may be arranged side by side along the horizontal plane. For example, when the first mold 303 and the second mold 304 are arranged side by side along the horizontal plane, in the arrangement step S30, for example, the intermediate 88 is hung between the first mold 303 and the second mold 304. Then, in the cutting step S40, the intermediate 88 is sandwiched between the first die 303 and the second die 304 from both sides in the direction along the horizontal plane. The sheet material 86 may be cut by adopting such a mode.

- You may change the mechanism which drives the cutting device 300 from the example of the said embodiment. For example, the cutting device 300 may be driven hydraulically.
- The waiting period M of the cutting step S40 is not limited to the example of the above embodiment. The waiting period M should be the length of time required for the cutting of the sheet material 86 to be completed.

- The method of producing the intermediate 88 in the intermediate producing step S20 is not limited to the example of the above embodiment. For example, as shown in FIG. 13, the intermediate body 88 may be produced using a pressing jig 600 . The pressing jig 600 has a first plate 601 and a second plate 602 made of copper, for example. When the intermediate body 88 is produced using the pressing jig 600 , first, the first sheet material 86A is arranged on the first plate 601 . A plurality of magnet bodies 82 are arranged on the first sheet member 86A. After that, the second sheet material 86B is arranged on the plurality of magnet bodies 82. As shown in FIG. Then, the second plate 602 is arranged thereon. In this manner, a plurality of magnet bodies 82 covered with two sheet materials 86 is sandwiched between the first plate 601 and the second plate 602 . Then, the first plate 601 and the second plate 602 are fixed with the bolts 603 in a state where the specified load N is applied to the two sheet members 86 . In this state, each magnet body 82 and two sheet members 86 are placed in the furnace 650 together with the pressing jig 600 . Furnace 650 is temperature adjustable. Thereafter, the temperature inside the furnace 650 is maintained at the first specified temperature Z1 for the first specified period L1. Thereafter, the temperature inside the furnace 650 is maintained at the second specified temperature Z2 for the second specified period L2. After that, the pressure jig 600 is taken out from the furnace 650 . Then, when the second plate 602 is removed together with the bolt 603, the intermediate body 88 is completed. Intermediate 88 may be produced in this manner. 13, like FIG. 6, the first sheet material 86A and the second sheet material 86B are marked with dots.

- The structure of the intermediate body 88 is not limited to the example of the said embodiment. For example, the number of magnet bodies 82 included in the intermediate body 88 may be changed from the number in the above embodiment. The number of magnet bodies 82 included in intermediate body 88 may be greater than the number of slots 64 in one rotor core 62 . The number of magnet main bodies 82 included in the intermediate body 88 may be two or more.

- The arrangement of the magnet main body 82 in the intermediate body 88 is not limited to the example of the above embodiment. For example, a plurality of magnet bodies 82 may be arranged in a plurality of rows.
- In the intermediate body 88, there may be no gap between adjacent magnet bodies 82 at all. Even when the first die 303 and the second die 304 are pressed against the intermediate body 88, the sheet material 86 is cut according to the elastic deformation of the first die 303 and the second die 304. That is, when the first mold 303 is pressed against the intermediate body 88, the first mold 303 is crushed between the first base member 301 and each magnet main body 82, and the first mold 303 extends laterally. It deforms elastically. Along with such elastic deformation, the first mold 303 separates the adjacent magnet bodies 82 from each other. This causes the sheet material 86 to be cut between adjacent magnet bodies 82 . The same applies to the second mold 304 as well.

- The shape and dimensions of the sheet material 86 are not limited to the examples of the above embodiment. The shape and dimensions of the sheet material 86 may be appropriately adjusted so that the plurality of magnet main bodies 82 forming the intermediate body 88 can be covered.

- The intermediate body 88 may not be formed by thermocompression bonding the sheet material 86 to the plurality of magnet main bodies 82 . For example, the intermediate body 88 may be formed by attaching the sheet material 86 to a plurality of magnet bodies 82 with, for example, an adhesive or double-sided adhesive tape. In this case, it is sufficient to temporarily fasten the sheet material 86 to the magnet main body 82, so the adhesive strength of the adhesive or the double-sided adhesive tape need not be so high. When such an intermediate body 88 is employed, the sheet material 86 may be thermocompression bonded to the magnet main body 82 after the cutting step S40. The intermediate body 88 may have a configuration in which a plurality of magnet bodies 82 are positioned on the same surface of the sheet material 86 .

- Only one sheet material 86 may be used to form the intermediate body 88 . That is, the intermediate body 88 may have a configuration in which the sheet material 86 covers only one of the two first surfaces 82A of each magnet body 82 .

- The structure of the intermediate manufacturing apparatus 200 is not limited to the example of the said embodiment. The intermediate manufacturing apparatus 200 may have any configuration as long as it can pressurize the sheet material 86 while heating it. For example, the mechanism for driving the intermediate manufacturing apparatus 200 may be changed from the example of the above embodiment. For example, the intermediate manufacturing apparatus 200 may be driven by hydraulic pressure.

- The material of the first pressure mold 201 is not limited to the example of the above embodiment. For example, the first pressure mold 201 may be made of iron. The same applies to the second pressure mold 202 as well. The first pressure mold 201 and the second pressure mold 202 may be made of different materials.

- When the sheet material 86 constituting the intermediate body 88 is one, as in the above modified example, the heater H built in either the first pressure mold 201 or the second pressure mold 202 is not necessarily required. do not do. In this case, the unnecessary heater H may be eliminated. The cooling water passage W is also the same. Also, the cooling water passage W may be eliminated from both the first pressurization die 201 and the second pressurization die 202 . Even in this case, the intermediate manufacturing apparatus 200 can be cooled by waiting for some time after the heater H is stopped.

- A structure other than the cooling water passage W may be used as a mechanism for cooling the first pressure mold 201 . The same applies to the mechanism for cooling the second pressure mold 202 .
- The 1st specified temperature Z1 of intermediate production process S20 may be considerably higher than the glass transition temperature of a thermoplastic resin fiber.

- The 2nd specified temperature Z2 of intermediate production process S20 may be considerably lower than the glass transition temperature of a thermoplastic resin fiber. The second specified temperature Z2 may be normal temperature, for example.
- The third specified temperature Z3 in the fixing step S60 may be different from the first specified temperature Z1 in the intermediate production step S20.

- The method of heating the sheet material 86 in the fixing step S60 is not limited to the example of the above embodiment. For example, high frequency induction heating may be used. That is, the rotor core 62 with the magnets 80 accommodated in the slots 64 is arranged inside the coil for induction heating. Then, the sheet material 86 may be heated together with the rotor core 62 by applying a current to the coil to generate a magnetic field.

- The type of permanent magnets forming the magnet main body 82 is not limited to the example of the above embodiment. The magnet main body 82 should just be a permanent magnet. Examples of permanent magnets employed in the magnet body 82 include ferrite magnets, alnico magnets, samarium-cobalt magnets, praseodymium magnets, samarium nitrogen iron magnets, platinum magnets, cerium-cobalt magnets, and the like.

- The shape of the magnet main body 82 is not limited to the example of the said embodiment. For example, the boundary between the first surface 82A and the second surface 82B may be chamfered. Even in this case, the first surface 82A and the second surface 82B are adjacent to each other via the chamfered surface. Also, the first surface 82A may be curved. Further, the magnet body 82 may have any shape that can be accommodated within the slot 64 of the rotor core 62 .

By changing the shape of the magnet body 82 from the example of the above-described embodiment, even if the magnet body 82 does not have an angular portion, the first mold 303 and the second mold 304 are elastically deformed so that the adjacent magnet bodies Sheet material 86 can be cut by acting to move 82 away.

- The type of thermoplastic resin fibers forming the sheet material 86 is not limited to the example of the above embodiment. The thermoplastic fibers may be, for example, polyethersulfone or polysulfone. Here, the rotor 60 may become hot during use of the motor 50 . Further, depending on the usage environment of the motor 50 , water or oil may splash on the rotor 60 or an external force may act on the rotor 60 . Considering these circumstances, the thermoplastic resin fibers preferably have high heat resistance, water resistance, oil resistance, creep resistance, thermal shock resistance, and insulating properties.

- When the type of thermoplastic resin fibers constituting the sheet material 86 is changed as in the above modification, the first specified temperature Z1 in the intermediate production step S20 is changed according to the glass transition temperature of the thermoplastic resin fibers to be adopted should be changed as appropriate. The first specified temperature Z1 may be determined as a temperature that is equal to or higher than the glass transition temperature of the employed thermoplastic resin fiber and lower than the temperature at which the employed thermoplastic resin fiber evaporates. The same applies to the third specified temperature Z3 in the fixing step S60.

- The second specified temperature Z2 may be changed according to the glass transition temperature of the thermoplastic resin fiber to be employed, as in the above modified example. The second specified temperature Z2 may be determined as a temperature lower than the glass transition temperature of the thermoplastic resin fibers employed.

- The type of inorganic fibers forming the sheet material 86 is not limited to the example of the above embodiment. As inorganic fibers, for example, rock wool, carbon fibers, alumina fibers, calcium silicate fibers, potassium titanate fibers, ceramic fibers, and the like may be employed.

- When the type of inorganic fibers forming the sheet material 86 is changed as in the above modified example, the specified load N in the intermediate production step S20 may be appropriately changed according to the inorganic fibers to be employed. The prescribed load N may be determined as a magnitude equal to or greater than the minimum load required to elastically compress the inorganic fibers employed and less than the minimum load at which the inorganic fibers employed are broken.

When the type of thermoplastic resin fibers constituting the sheet material 86 is changed or the type of inorganic fibers is changed, depending on the combination of the thermoplastic resin fibers and the inorganic fibers, the first The prescribed period L1 may be changed as appropriate. The first specified period L1 is the time required for the inorganic plastic fiber of the sheet material 86 to soften sufficiently to elastically compress the inorganic fiber of the sheet material 86 while the sheet material 86 is at the first specified temperature Z1. It should be defined as a length. As with the first specified period L1, the second specified period L2 of the intermediate production step S20 and the third specified period L3 of the fixing step S60 may be appropriately changed according to the combination of thermoplastic resin fibers and inorganic fibers.

- 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 be arranged, for example, along the circumferential direction of the rotor core 62 instead of the V-shaped arrangement as in the above embodiment. As long as the magnets 80 can be arranged so that the N poles and S poles are arranged alternately in the circumferential direction of the rotor core 62, the arrangement of the slots 64 does not matter.

- The number of slots 64 in the rotor core 62 is not limited to the example of the above embodiment. As in the modification above, the number of slots 64 does not matter as long as the magnetic poles can be formed appropriately.
- If high efficiency is not important in manufacturing the rotor 60, it is not essential to use the technique of thermally expanding the sheet material 86 in fixing the magnets 80 to the rotor core 62. If the magnets 80 are fixed to the rotor core 62 by a technique other than thermally expanding the sheet material 86, the sheet material 86 need not contain thermoplastic resin fibers and inorganic fibers. Regardless of the configuration of the sheet material 86 , it is effective to use the cutting device 300 to cut the sheet material 86 of the intermediate body 88 to produce the plurality of magnets 80 .

- A plurality of magnets may be manufactured using the cutting device 300 for the purpose of manufacturing magnets to be attached to a part other than the rotor 60 .

60... Rotor 62... Rotor core 64... Slot 80... Magnet 82... Magnet main body 82A... First surface 82B... Second surface 82S... Boundary 86... Sheet material 88... Intermediate body 303... First mold 304... Second mold 353... Second mold First die 354 Second die 353B Projected surface 353P Flat surface 354B Projected surface 354P Flat surface

Claims (5)

an intermediate manufacturing step of manufacturing an intermediate in which a plurality of magnet bodies are positioned on the same surface of a sheet material;
A first mold made of an elastic material having a smaller elastic modulus than the magnet body and a second mold facing the first mold, on the opposite side of the sheet material where the magnet body is located. an arrangement step of arranging the intermediate body so that the surface of the intermediate body faces the first mold;
and a cutting step of cutting the sheet material between the magnet bodies arranged adjacent to each other by sandwiching the intermediate between the first mold and the second mold. The magnet body has a planar first surface and a planar second surface adjacent to the first surface,
2. The method of manufacturing a magnet according to claim 1, wherein in the step of preparing the intermediate body, the plurality of magnet bodies are arranged on the same surface of the sheet material so that the first surface is in contact with the sheet material. The surface facing the sheet material in the first mold has a planar flat surface and a protruding surface protruding from the flat surface,
3. The magnet according to claim 2, wherein in the arranging step, the intermediate body is arranged such that a boundary between the first surface and the second surface of the magnet body faces the projecting surface with the sheet material interposed therebetween. manufacturing method. The sheet material contains thermoplastic resin fibers and inorganic fibers,
In the intermediate manufacturing step, the sheet material is pressed while being heated to a temperature equal to or higher than the glass transition temperature of the thermoplastic resin fiber, so that the sheet material is attached to the plurality of magnet bodies while the inorganic fibers are elastically compressed. The method for producing a magnet according to any one of claims 1 to 3, wherein the magnet is thermocompression bonded. In a state in which a plurality of magnet bodies are positioned on the same surface of a sheet material containing thermoplastic resin fibers and inorganic fibers, the sheet material is heated to a temperature equal to or higher than the glass transition temperature of the thermoplastic resin fibers and pressurized to remove the inorganic fibers. an intermediate manufacturing step of manufacturing an intermediate by thermocompression bonding the sheet material to a plurality of the magnet bodies in a state where the fibers are elastically compressed;
A first mold made of an elastic material having a smaller elastic modulus than the magnet body and a second mold facing the first mold, on the opposite side of the sheet material where the magnet body is located. an arrangement step of arranging the intermediate body so that the surface of the intermediate body faces the first mold;
By sandwiching the intermediate body between the first die and the second die, the sheet material is cut between the magnet bodies arranged adjacent to each other to form a magnet in which the magnet body is covered with the sheet material. a cutting step to produce;
a fixing step of fixing the magnets to the rotor core by heating the magnets to a temperature equal to or higher than the glass transition temperature while the magnets are arranged in slots formed in the rotor core, thereby elastically restoring the inorganic fibers. manufacturing method.

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