Method for manufacturing rotor for IPM motor and manufacturing apparatus for rotor for IPM motor

Abstract

A manufacturing method and manufacturing apparatus for a rotor for an IPM motor, capable of suppressing breakage of a rotor magnet in a process of fixing the rotor magnet to a rotor core. The manufacturing method for a rotor for an IPM motor includes a rotor magnet insertion process of inserting a rotor magnet into a magnet insertion hole; a rotor magnet positioning process of pushing a side end face of the rotor magnet in an axial direction, which is inserted into the magnet insertion hole, to the other side in the axial direction within the magnet insertion hole; a first riveting process of riveting an end face of the other side in the axial direction of the rotor core in the axial direction around the magnet insertion hole in a state where the rotor magnet is pushed to the other side in the axial direction by the rotor magnet positioning process; and a second riveting process of riveting an end face of the one side in the axial direction of the rotor core in the axial direction around the magnet insertion hole, thereby fixing the rotor magnet within the magnet insertion hole.

Description

TECHNICAL FIELD

[0001] The present application relates to a manufacturing method of a rotor for an IPM motor and a manufacturing apparatus of a rotor for an IPM motor. BACKGROUND

[0002] A method of fixing a rotor magnet inserted into a magnet insertion hole of a rotor core by caulking an end surface of the rotor core in an axial direction of the rotor core in the axial direction is known. For example, a method of fixing a magnet to a rotor core by caulking is disclosed in Patent Literature 1. The rotor core is formed with a recessed portion of a shape recessed inward from a radially inner side of a through hole for inserting a magnet. In the above-described rotor core, each open front end portion of the recessed portion is pressed against the magnet in a radially outer direction by caulking performed on core pieces at both ends in the axial direction. Thereby, the magnet is fixed by the open front end portions of the recessed portion.

[0003] [Patent Literature]

[0004] [Patent Literature]

[0005] [Patent Literature 1] Japanese Patent Application Publication No. 2017-169400 SUMMARY

[0006] However, a rotor magnet inserted into a magnet insertion hole is shorter in length in an axial direction of the magnet insertion hole than the above-described magnet insertion hole. Therefore, when caulking an end surface of a rotor core in the axial direction of the rotor core, the rotor magnet sometimes moves in the magnet insertion hole in a direction pushed by caulking. Therefore, for example, after caulking an end surface on one side in the axial direction of the rotor core, if caulking is performed on an end surface on the opposite side, the rotor magnet moves in the magnet insertion hole in a state of contacting a protrusion portion formed when caulking the end surface on the one side. At this time, the rotor magnet can possibly be broken by the protrusion portion formed when caulking the end surface on the one side. Therefore, a manufacturing method capable of suppressing breakage of the rotor magnet in a process of fixing the rotor magnet to the rotor core is sought.

[0007] An object of the present application is to provide a manufacturing method capable of suppressing breakage of a rotor magnet in a process of fixing the rotor magnet to a rotor core.

[0008] The manufacturing method of the rotor for an IPM motor of one embodiment of the present application is a manufacturing method of a rotor for an IPM motor including a rotor core including a plurality of disc-shaped core plates stacked in a thickness direction and a magnet insertion hole in which a rotor magnet is accommodated. The manufacturing method of the rotor for an IPM motor includes a rotor magnet insertion step of inserting the rotor magnet into the magnet insertion hole, a rotor magnet positioning step of pushing a side end surface of the rotor magnet in an axis direction on the other side in the axis direction within the magnet insertion hole, a first riveting step of riveting an end surface of the rotor core on the other side in the axis direction around the magnet insertion hole in the axis direction in a state where the rotor magnet is pushed on the other side in the axis direction by the rotor magnet positioning step, and a second riveting step of riveting an end surface of the rotor core on the side in the axis direction around the magnet insertion hole in the axis direction, whereby the rotor magnet is fixed in the magnet insertion hole.

[0009] The manufacturing device of the rotor for an IPM motor of one embodiment of the present application is a manufacturing device of a rotor for an IPM motor including a rotor core including a plurality of disc-shaped core plates stacked in a thickness direction and a magnet insertion hole in which a rotor magnet is accommodated. The manufacturing device of the rotor for an IPM motor includes a rotor core support portion which supports the rotor core in a state where an axis direction coincides with an up-down direction, a magnet upward pushing mechanism which pushes a lower end surface of the rotor magnet upward to move the rotor magnet upward within the magnet insertion hole, and a riveting mechanism including a pin which rivets the rotor core in the axis direction and a pin moving portion which moves the pin in the up-down direction with respect to the rotor core.

[0010] According to the manufacturing method of the rotor of the present application, a manufacturing method in which breakage of a rotor magnet can be suppressed in a process of fixing the rotor magnet to a rotor core can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 FIG. 1 is a diagram illustrating a schematic structure of a motor including a rotor manufactured by a rotor manufacturing device of an embodiment.

[0012] Figure 2 FIG. 2 is a perspective view illustrating a schematic structure of a rotor.

[0013] Figure 3 FIG. 3 is a III-III line sectional view of FIG. 1. Figure 2

[0014] Figure 4 FIG. 4 is a diagram illustrating a schematic structure of a rotor manufacturing device of an embodiment.

[0015] ​Figure 5 is a flowchart showing a manufacturing method of a rotor.

[0016] Figure 6 is a diagram schematically showing a state in which a rotor magnet is inserted in a magnet insertion hole.

[0017] Figure 7 is a diagram schematically showing a state in which a magnet moving portion pushes a magnet.

[0018] Figure 8 is a diagram schematically showing a state in which a riveting of the other side end surface of a rotor core is performed.

[0019] Figure 9 is a diagram schematically showing a state in which a riveting of the one side end surface of a rotor core is performed.

[0020] (Symbol explanation)

[0021] 1 Rotor manufacturing device (IPM motor rotor manufacturing device); 2 Rotor core support portion; 3 Upper side positioning member; 5 Magnet pushing-up mechanism; 6 Riveting mechanism; 8 Motor; 21 Spring housing portion; 51 Compression coil spring; 52 Spring support portion; 61 Pin; 62 Pin moving portion; 80 Rotor; 81 Rotor core; 81a Through-hole; 81b Riveting trace; 81c First end surface; 81d Second end surface; 82 Rotor magnet; 83 Core plate; 84 Magnet insertion hole; 85 First protruding portion; 85a Protruding front end portion; 86 Second protruding portion; 90 Stator; 91 Housing; 92 Shaft; 93 Stator core; 94 Stator coil. DETAILED DESCRIPTION

[0022] Exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. In addition, the same or similar portions in the drawings are designated by the same reference numerals and their explanations will not be repeated. In addition, the sizes of the constituent members in each drawing are not faithfully shown to the sizes of the actual constituent members and the size ratios of the constituent members, and the like.

[0023] In addition, in the following explanation, a direction parallel to the central axis P of the rotor 80 placed on the rotor manufacturing device 1 will be referred to as an "axial direction", a direction orthogonal to the central axis P will be referred to as a "radial direction", and a direction along a circular arc centered on the central axis P will be referred to as a "circumferential direction". In addition, in the radial direction, the central axis P side will be referred to as a "radially inner side" with respect to the structure as an object, and the side opposite to the central axis P will be referred to as a "radially outer side" with respect to the structure as an object. In addition, in the following explanation, a vertical direction in a state in which the rotor manufacturing device 1 is provided will be referred to as an "up-down direction", and a direction orthogonal to the up-down direction will be referred to as a "left-right direction". However, it is not intended to limit the orientation at the time of use of the rotor manufacturing device 1 of the present application by the definition of the directions.

[0024] In addition, in the following description, "fixing", "connecting", "joining", and "mounting" and the like (hereinafter referred to as fixing and the like) include not only cases where components are fixed to each other directly, but also cases where components are fixed to each other via other components. That is, in the following description, the expression of fixing and the like includes direct and indirect fixing and the like of components to each other.

[0025] (Embodiment)

[0026] The rotor manufacturing device 1 of the exemplary embodiment of the present application is a manufacturing device of a rotor 80 for an IPM motor. First, the motor 8 provided with the rotor 80 manufactured by the rotor manufacturing device 1 is simply described with reference to Figure 1 and Figure 2

[0027] (Structure of Motor)

[0028] Figure 1 is a diagram showing the schematic structure of the motor 8. The motor 8 is an IPM motor. The motor 8 includes the rotor 80, a stator 90, a housing 91, and a shaft 92. The rotor 80 rotates with the center axis P as the center with respect to the stator 90. In the present embodiment, the motor 8 is a so-called inner rotor type motor in which the rotor 80 is rotatably positioned inside the cylindrical stator 90 with the center axis P as the center.

[0029] The rotor 80 has a rotor core 81 and rotor magnets 82. The rotor 80 is positioned on the radially inner side of the stator 90 and is rotatable with the center axis P as the center with respect to the stator 90.

[0030] The stator 90 is housed in the housing 91. In the present embodiment, the stator 90 is cylindrical. The rotor 80 is positioned on the radially inner side of the stator 90. That is, the stator 90 opposes the rotor 80 in the radial direction.

[0031] The stator 90 has a stator core 93 and a stator coil 94. The stator coil 94 is wound around the stator core 93. The detailed structure of the stator 90 is omitted.

[0032] Figure 2 is a perspective view showing the schematic structure of the rotor 80. The rotor core 81 of the rotor 80 is cylindrical and extends along the center axis P. The rotor core 81 has a through-hole 81a extending along the center axis P. As shown in Figure 1 , the shaft 92 is fixed to the rotor core 81 in a state of penetrating the through-hole 81a in the axial direction. Thus, the rotor core 81 rotates together with the shaft 92.

[0033] In addition, the rotor core 81 has a plurality of magnet insertion holes 84 arranged at a prescribed interval in the circumferential direction. The plurality of magnet insertion holes 84 penetrate the rotor core 81 in the axial direction. The plurality of magnet insertion holes 84 are rectangular. The rotor magnets 82 are housed in these magnet insertion holes 84.​

[0034] The rotor core 81 has a plurality of disc-shaped core plates 83 formed into a prescribed shape and stacked in the thickness direction. The plurality of core plates 83 are electromagnetic steel sheets. The plurality of core plates 83 each have an opening that constitutes a portion of a magnet insertion hole 84.

[0035] The rotor core 81 has a riveting mark 81b that is recessed in the axial direction at a riveting position Q in the periphery of the magnet insertion hole 84. In the present embodiment, the riveting mark 81b is located in the rotor core 81 at a position that is radially inward of the magnet insertion hole 84. In addition, in the example shown in FIG. 1, two riveting marks 81b are located at positions that are radially inward of the magnet insertion hole 84. Figure 2

[0036] Figure 3 is a cross-sectional view taken along the line III-III in FIG. 1. As shown in FIG. 2, the riveting mark 81b is located on a first end face 81c that is one end face of the rotor core 81 in the axial direction. In addition, the riveting mark 81b is also located on a second end face 81d that is the other end face of the rotor core 81 in the axial direction. The riveting mark 81b is a press mark of a pin 61 that rivets the first end face 81c and the second end face 81d in the axial direction in a rotor manufacturing device 1 described later. Figure 2 Figure 3

[0037] The rotor core 81 has a first protrusion 85 that protrudes into the interior of the magnet insertion hole 84 on the first end face 81c side of the inner surface of the magnet insertion hole 84, and a second protrusion 86 that protrudes into the interior of the magnet insertion hole 84 on the second end face 81d side. The first protrusion 85 is formed by riveting the first end face 81c in the axial direction at the riveting position Q in a first riveting process in a rotor manufacturing process described later. The second protrusion 86 is formed by riveting the second end face 81d in the axial direction at the riveting position Q in a second riveting process in the manufacturing process of the rotor 80 described later. That is, in the process prior to the above first riveting process and the above second riveting process, the rotor core 81 does not have the first protrusion 85 and the second protrusion 86.

[0038] ​​​The rotor magnet 82 is columnar. The length in the axial direction of the rotor magnet 82 is shorter than the length in the axial direction of the magnet insertion hole 84. Therefore, in a state of being inserted into the magnet insertion hole 84, at least one of the end surfaces on both sides in the axial direction of the rotor magnet 82 is recessed in the axial direction with respect to the end surface in the axial direction of the rotor core 81. The rotor magnet 82 is rectangular as viewed in the axial direction. The length in the short side direction of the rotor magnet 82 is shorter than the length between the long sides extending in the length direction of the magnet insertion hole 84 as viewed in the axial direction. The rotor magnet 82 is held in a state of being inserted into the magnet insertion hole 84 by the first protruding portion 85 and the second protruding portion 86. In the present embodiment, the rotor magnet 82 is fixed to the rotor core 81 in a state where the position of the end surface in the axial direction of the rotor magnet 82 coincides with the position of the first end surface 81c of the rotor core 81.

[0039] (protruding portion)

[0040] Next, with reference to Figure 3 , the riveting that forms the first protruding portion 85 will be described. By pushing the pin 61 in the axial direction against the first end surface 81c at the riveting position Q, among the core plates 83 that constitute the first end surface 81c of the rotor core 81 and the plurality of core plates 83 adjacent in the stacking direction of the core plates 83, the portion between the riveting position Q and the magnet insertion hole 84 bulges toward the inside of the magnet insertion hole 84. Thereby, the first protruding portion 85 that protrudes inside is formed on the inner surface of the magnet insertion hole 84. The first protruding portion 85 has a protruding tip portion 85a of which a part of the protruding portion protrudes most toward the inside of the magnet insertion hole 84.

[0041] In the present embodiment, the position of the upper end surface among the end surfaces on both sides in the axial direction of the rotor magnet 82 coincides with the position of the first end surface 81c of the rotor core 81. Therefore, the position at which the protruding tip portion 85a of the first protruding portion 85 formed by riveting the first end surface 81c contacts the rotor magnet 82 is farther from the end portion in the axial direction of the rotor magnet 82 than when the first end surface 81c of the rotor core 81 is recessed with respect to the upper end surface of the rotor magnet 82. Although detailed description is omitted, by similarly riveting the second end surface 81d, the second protruding portion 86 is formed on the inner surface of the magnet insertion hole 84 on the second end surface 81d side.

[0042] (rotor manufacturing device)

[0043] Next, with reference to Figure 4 , the rotor manufacturing device 1 of the exemplary embodiment that manufactures the rotor 80 having the above structure will be described in detail. The rotor manufacturing device 1 has a rotor core support portion 2, an upper side positioning member 3, a magnet upward pushing mechanism 5, and a riveting mechanism 6.

[0044] The rotor core support portion 2 is a flat plate shape extending in the left-right direction. The rotor core support portion 2 supports the rotor core 81 in a state in which the axial direction of the rotor core 81 coincides with the up-down direction. That is, the rotor core 81 is placed on the rotor core support portion 2 in a state in which the axial direction coincides with the up-down direction. The rotor core support portion 2 has a spring housing portion 21 recessed downward at a position overlapping the magnet insertion hole 84 of the rotor core 81 when viewed in the axial direction in a state in which the rotor core 81 is placed. Inside the spring housing portion 21, a compression coil spring 51 and a spring support portion 52 of a magnet push-up mechanism 5 described later are housed.

[0045] The rotor core support portion 2 has a rotor core positioning portion for positioning the magnet insertion hole 84 of the rotor core 81 at a position overlapping the spring housing portion 21 when viewed in the axial direction. The illustration of the rotor core positioning portion is omitted. In addition, the explanation of the structure of the rotor core positioning portion is omitted.

[0046] The upper positioning member 3 is a flat plate shape extending in the left-right direction. The upper positioning member 3 is supported on the rotor core support portion 2. The upper positioning member 3 is driven by an unillustrated actuator to move in the up-down direction. In detail, the upper positioning member 3 moves in the up-down direction between a position above the upper end surface of the rotor core 81 and a position in contact with the end surface. The upper positioning member 3 is held at a position in contact with the upper end surface of the rotor core 81 in a state in which the rotor core 81 is placed on the rotor core support portion 2 and the rotor magnet 82 is inserted into the magnet insertion hole 84 of the rotor core 81.

[0047] The upper positioning member 3 has a through-hole that penetrates to a position radially inside the magnet insertion hole 84 of the rotor core 81 in a state in which the rotor core 81 is placed on the rotor core support portion 2 in the thickness direction. The through-hole is located at a riveting position Q at which the rotor core 81 placed on the rotor core support portion 2 is riveted. A pin 61 described later is inserted into the through-hole in a manner so as to be movable in the axial direction.

[0048] The magnet push-up mechanism 5 pushes the rotor magnet 82 inside the magnet insertion hole 84 upward in a state in which the rotor core 81 is placed on the rotor core support portion 2. In the present embodiment, the magnet push-up mechanism 5 includes the compression coil spring 51 and the spring support portion 52. The compression coil spring 51 is housed in the spring housing portion 21 of the rotor core support portion 2 in a state in which the extension direction coincides with the up-down direction.

[0049] The spring support portion 52 supports the end surface of the lower side of the rotor magnet 82. The spring support portion 52 is a member extending in the up-down direction. The spring support portion 52 is supported by the compression coil spring 51. The spring support portion 52 is housed in the spring housing portion 21 by the compression coil spring 51 being compressed. By releasing the compression state of the compression coil spring 51, the upper side end portion of the spring support portion 52 protrudes upward from the upper surface of the rotor core support portion 2. That is, the spring support portion 52, in a state in which the rotor core 81 is placed on the rotor core support portion 2, pushes the rotor magnet 82 upward in the magnet insertion hole 84 by the elastic restoring force of the compression coil spring 51. Therefore, the compression coil spring 51 is an elastic member that pushes the rotor magnet 82 upward in the magnet insertion hole 84 by the elastic restoring force.

[0050] The riveting mechanism 6 has a pin 61 and a pin moving portion 62. The pin 61 is a columnar member. The pin 61 has a tapered portion that is smaller in diameter toward the front end at the front end portion. The pin 61 is held on the pin moving portion 62 with the front end downward. The front end side of the pin 61 is inserted into the through hole of the upper side positioning member 3.

[0051] The pin moving portion 62 is a flat plate shape extending in the left-right direction. The pin moving portion 62 is supported by the upper side positioning member 3. The pin moving portion 62 is located above the upper side positioning member 3. The pin moving portion 62 moves in the up-down direction. By this, the pin moving portion 62 moves the pin 61 held on the lower side in the up-down direction. In the present embodiment, the pin moving portion 62 moves the pin 61 between a position in which the front end of the pin 61 is housed in the through hole of the upper side positioning member 3 and a position in which the front end protrudes downward from the through hole. By moving the pin 61 downward by the pin moving portion 62, the end surface of the upper side of the rotor core 81 placed on the rotor core support portion 2 is riveted in the axial direction.

[0052] That is, in a state in which the first end surface 81c is located on the upper side in the axial direction of the rotor core 81, by causing the riveting mechanism 6 to operate, a first protruding portion 85 is formed on the first end surface 81c side of the inner surface of the magnet insertion hole 84. In addition, in a state in which the second end surface 81d is located on the upper side in the axial direction of the rotor core 81, by causing the riveting mechanism 6 to operate, a second protruding portion 86 is formed on the second end surface 81d side of the inner surface of the magnet insertion hole 84.

[0053] That is, the rotor manufacturing apparatus 1 having the above structure is an IPM motor rotor manufacturing apparatus provided with a rotor core 81 having a plurality of disc-shaped core plates 83 stacked in a thickness direction and a magnet insertion hole 84 capable of accommodating a rotor magnet 82. The rotor manufacturing apparatus 1 has a rotor core support portion 2 that supports the rotor core 81 in a state in which an axial direction and an up-down direction coincide with each other, a magnet upward pushing mechanism 5 that pushes a lower side end surface of the rotor magnet 82 upward to move the rotor magnet 82 upward within the magnet insertion hole 84, and a riveting mechanism 6 that has a pin 61 that rivets the rotor core 81 in the axial direction and a pin moving portion 62 that moves the pin 61 in the up-down direction with respect to the rotor core 81.

[0054] According to the above structure, the magnet upward pushing mechanism 5 is capable of holding the rotor magnet 82 in a state in which the rotor magnet 82 is pushed upward. Thereby, when the first end surface 81c of the rotor core is riveted in the axial direction of the rotor core, it is possible to suppress the rotor magnet from moving downward with respect to the rotor core due to riveting and gravity. Thus, it is possible to make the protruding tip end portion 85a of the first protruding portion 85 formed on the inner surface of the magnet insertion hole by riveting contact with a position that is farthest from the end portion in the axial direction of the rotor magnet 82.

[0055] In the present embodiment, the magnet upward pushing mechanism 5 is constituted by an elastic member that pushes the rotor magnet 82 upward within the magnet insertion hole 84 by elastic restoring force. By using the elastic restoring force of the elastic member in this way, it is possible to easily move the rotor magnet 82 with respect to the rotor core 81.

[0056] In the present embodiment, the rotor manufacturing apparatus 1 has an upper side positioning member 3 that positions a position of an upper side end surface of the rotor magnet 82 inserted into the magnet insertion hole 84 with respect to the rotor core 81. Thereby, in the axial direction of the rotor core 81, it is possible to make the rotor magnet 82 be positioned at the uppermost side within the magnet insertion hole 84. Thereby, it is possible to make the protruding tip end portion 85a of the first protruding portion 85 formed on the inner surface of the magnet insertion hole 84 by riveting contact with a position that is farthest from the end portion in the axial direction of the rotor magnet 82.

[0057] (Method of manufacturing rotor)

[0058] An example method of manufacturing the rotor 80 by the rotor manufacturing apparatus 1 will now be described with reference to Figures 5 to 9 An example method of manufacturing the rotor 80 by the rotor manufacturing apparatus 1 will now be described with reference to

[0059] Figure 5 is a flowchart showing a method of manufacturing the rotor 80. The method of manufacturing the rotor has a rotor core placement process S1, a rotor magnet insertion process S2, a rotor magnet positioning process S3, a first riveting process S4, a rotor core up-down flipping process S5, and a second riveting process S6.

[0060] In the rotor core placement step S1, the rotor core 81 is placed on the rotor core support portion 2 of the rotor manufacturing apparatus 1 with the first end surface 81c of the rotor core 81 on the upper side. At this time, the first protruding portion 85 and the second protruding portion 86 are not formed on the rotor core 81.

[0061] In the rotor magnet insertion step S2, the rotor magnet 82 is inserted into the magnet insertion hole 84 of the rotor core 81 placed on the rotor core support portion 2 of the rotor manufacturing apparatus 1. Figure 6 is a view schematically showing a state after the rotor magnet 82 is just inserted into the magnet insertion hole 84. As shown in Figure 6 the lower side end surface of the rotor magnet 82 inserted into the magnet insertion hole 84 is supported by the spring support portion 52 of the magnet push-up mechanism 5 protruding from the rotor core support portion 2. Thereby, the upper side end surface of the rotor magnet 82 is positioned at a position higher than the first end surface 81c of the rotor core 81.

[0062] In the rotor magnet positioning step S3, after the rotor magnet 82 is inserted into the magnet insertion hole 84, the upper side positioning member 3 is moved to a position in contact with the upper side first end surface 81c of the rotor core 81. Thereby, as shown in Figure 7 the upper side end surface of the rotor magnet 82 positioned at a position higher than the first end surface 81c of the rotor core 81 is pushed down by the upper side positioning member 3. In addition, the spring support portion 52 in contact with the lower side end surface of the rotor magnet 82 pushes up the rotor magnet 82 by the elastic restoring force of the compression coil spring 51. Therefore, the rotor magnet 82 is held at a position where the upper side end surface coincides with the position of the first end surface 81c on the upper side of the rotor core 81. That is, the rotor magnet 82 is positioned at the uppermost position in the axial direction within the magnet insertion hole 84. In the rotor magnet positioning step S3, the lower side end surface of the rotor magnet 82 in the axial direction is the one end surface of the present application.

[0063] In the first riveting step S4, the first end surface 81c of the rotor core 81 is riveted in the axial direction at the riveting position Q in a state where the rotor magnet 82 is pushed up with respect to the rotor core 81. Thereby, as shown in Figure 8 the first end surface 81c of the inner surface within the magnet insertion hole 84 is formed with the first protruding portion 85. Thereby, the rotor magnet 82 is pressed by the first protruding portion 85 in the direction in which the first protruding portion 85 protrudes within the magnet insertion hole 84. Thereby, the position of the rotor magnet 82 in the magnet insertion hole 84 where the position of one end surface coincides with the position of the first end surface 81c is fixed with respect to the position of the rotor core 81 in the axial direction.

[0064] In the rotor core upside-down turning step S5, as shown in Figure 9The upper and lower positions of the first end surface 81c and the second end surface 81d of the rotor core 81 placed on the rotor core support portion 2 are exchanged as shown. That is, the rotor core 81 is placed on the rotor core support portion 2 of the rotor manufacturing device 1 in a state where the second end surface 81d of the rotor core 81 is on the upper side. Thus, the first protruding portion 85 formed in the first riveting process S4 is disposed on the lower side of the rotor core 81. That is, the rotor core 81 is placed on the rotor core support portion 2 in a state where the rotor magnet 82 is fixed by the first protruding portion 85 on the lower side in the axial direction and the rotor magnet 82 is located at the lowermost position in the axial direction within the magnet insertion hole 84. Thus, the compression coil spring 51 of the magnet push-up mechanism 5 is housed in the spring housing portion 21 in a compressed state.

[0065] In the second riveting process S6, the second end surface 81d of the rotor core 81 is riveted in the axial direction at the riveting position Q. Thus, the second protruding portion 86 is formed at a position of the inner surface within the magnet insertion hole 84 close to the second end surface 81d. At this time, the position of the rotor magnet 82 in the axial direction with respect to the rotor core 81 is fixed by the first protruding portion 85. In addition, the end surface of the lower side of the rotor magnet 82 is pushed upward by the magnet push-up mechanism 5. Therefore, it is possible to suppress the movement of the rotor magnet 82 in the axial direction downward within the magnet insertion hole 84.

[0066] That is, the manufacturing method of the rotor described above is a manufacturing method of an IPM motor rotor provided with a rotor core 81 having a plurality of disc-shaped core plates 83 stacked in the thickness direction and a magnet insertion hole 84 capable of housing a rotor magnet 82. The manufacturing method of the rotor has: a rotor magnet insertion process of inserting the rotor magnet 82 into the magnet insertion hole 84; a rotor magnet positioning process of pushing the one end surface of the rotor magnet 82 inserted into the magnet insertion hole 84 in the axial direction to the other side within the magnet insertion hole 84; a first riveting process of riveting the end surface of the other side of the rotor core 81 in the axial direction around the magnet insertion hole 84 in the axial direction in a state where the rotor magnet 82 is pushed to the other side in the axial direction by the rotor magnet positioning process; and a second riveting process of riveting the end surface of the one side of the rotor core 81 in the axial direction around the magnet insertion hole 84 in the axial direction to fix the rotor magnet 82 within the magnet insertion hole 84.

[0067] In the manufacturing method of the rotor described above, the end surface on the other side in the axis direction of the rotor core 81 is riveted in a state where the end surface on the one side in the axis direction of the rotor magnet 82 inserted into the magnet insertion hole 84 is pushed in the other side in the axis direction of the magnet insertion hole 84. Thereby, the rotor magnet 82 can be restrained from moving in the magnet insertion hole 84 when the rotor core is riveted. In addition, the protruding tip end portion 85a of the first protruding portion 85 formed on the inner surface of the magnet insertion hole 84 by riveting can be brought into contact with a position apart from the end portion in the axis direction of the rotor magnet 82. Thereby, the rotor magnet 82 can be restrained from breaking at the contact position of the protruding tip end portion 85a when the end surface on the other side in the axis direction of the rotor core 81 is riveted in the axis direction.

[0068] In addition, in the rotor magnet positioning step S3, the rotor core 81 is disposed in a state where the axis direction described above coincides with the vertical direction, and the end surface on the lower side of the rotor magnet 82 is pushed upward.

[0069] In the case where the axis direction of the rotor core 81 is the vertical direction, the first end surface 81c of the rotor core on the upper side can be held in a state where the rotor magnet 82 is lifted when the first end surface 81c is riveted below in the axis direction. Thereby, the rotor magnet 82 can be restrained from moving downward with respect to the rotor core 81 due to riveting and gravity. In addition, the protruding tip end portion 85a of the first protruding portion 85 formed by riveting can be brought into contact with a position apart from the end portion in the axis direction of the rotor magnet 82. Therefore, the rotor magnet 82 can be restrained from breaking at the contact position of the protruding tip end portion 85a when the second end surface 81d on the opposite side in the axis direction of the rotor core 81 is riveted in the axis direction.

[0070] In addition, in the rotor magnet positioning step S3, the end surface on the one side in the axis direction of the rotor magnet 82 is pushed in the other side in the axis direction of the magnet insertion hole 84 by the elastic restoring force of the elastic member. In this way, the rotor magnet 82 can be easily moved with respect to the rotor core 81 by using the elastic restoring force of the elastic member.

[0071] In addition, in the rotor magnet positioning step, the rotor magnet 82 is moved in the axis direction until the end surface on the other side of the rotor magnet 82 coincides with the end surface on the other side in the axis direction of the rotor core 81.

[0072] Thus, the rotor magnet 82 can be positioned at the most other side with respect to the rotor core 81 in the axial direction of the rotor core 81. Thus, the protruding tip portion 85a of the first protruding portion 85 formed on the inner surface of the magnet insertion hole 84 by caulking can be brought into contact with a position apart from the end portion in the axial direction of the rotor magnet 82. Thus, when caulking the end surface of the one side in the axial direction of the rotor core 81 along the axial direction, the rotor magnet 82 can be prevented from being broken at the contact position of the protruding tip portion 85a.

[0073] (Other Embodiments)

[0074] The above-described embodiments are merely examples for carrying out the present application. Thus, the present application is not limited to the above-described embodiments, and the above-described embodiments can be appropriately modified without departing from the scope of the present application.

[0075] In the above-described embodiment, the magnet pushing-up mechanism 5 of the rotor manufacturing device 1 does not compress the compression coil spring 51 when the rotor magnet 82 is inserted into the magnet insertion hole 84 of the rotor core 81 in the rotor magnet insertion process S2. However, the magnet pushing-up mechanism can be configured to compress the compression coil spring when the rotor magnet is inserted into the magnet insertion hole, and to release the compression of the compression coil spring in the rotor magnet positioning process S3.

[0076] In the above-described embodiment, the magnet pushing-up mechanism 5 of the rotor manufacturing device 1 positions the rotor magnet 82 at the uppermost position in the axial direction in the magnet insertion hole 84 by bringing the rotor magnet 82 into contact with the upper positioning member 3. However, the magnet pushing-up mechanism can position the rotor magnet at a position lower than the uppermost position in the axial direction in the magnet insertion hole.

[0077] In the above-described embodiment, the magnet pushing-up mechanism 5 of the rotor manufacturing device 1 is configured by the compression coil spring 51 that pushes the rotor magnet by the elastic restoring force. However, the magnet pushing-up mechanism can be configured by members other than the compression coil spring as long as the magnet pushing-up mechanism can push the rotor magnet.

[0078] In the above-described embodiment, the magnet pushing-up mechanism 5 of the rotor manufacturing device 1 determines the pushing-up amount by the elastic restoring force of the compression coil spring 51. However, the amount by which the rotor magnet is pushed upward can be controlled by an actuator.

[0079] In the above-described embodiment, the rotor manufacturing device 1 has the upper positioning member 3. However, the rotor manufacturing device can not have the upper positioning member.

[0080] In the above embodiment, the riveting mechanism 6 of the rotor manufacturing device 1 is held on the upper positioning member 3. However, the riveting mechanism 6 can be held on the rotor core support portion. The riveting mechanism 6 can be held on both the upper positioning member and the rotor core support portion. In this case, it can be a structure in which the riveting mechanism held by the upper positioning member and the riveting mechanism held by the rotor core support portion respectively rivet both end surfaces in the axial direction of the rotor core.

[0081] In the above embodiment, the riveting mechanism 6 of the rotor manufacturing device 1 is located at the upper portion of the rotor manufacturing device 1. However, the riveting mechanism can be located at the lower portion of the rotor manufacturing device. The riveting mechanism can be located at both the upper portion and the lower portion of the rotor manufacturing device. In this case, it can be a structure in which the riveting mechanism at the upper portion rivets the end surface on the upper side of the rotor core in the axial direction along the axial direction, and the riveting mechanism at the lower portion rivets the end surface on the lower side of the rotor core in the axial direction along the axial direction.

[0082] In the above embodiment, the manufacturing process of the rotor core has the rotor core upside-down turning process S5. However, the manufacturing process of the rotor core can not have the rotor core upside-down turning process. In this case, in the second riveting process S6, the riveting mechanism located at the lower portion of the rotor manufacturing device can be used to rivet the end surface on the lower side of the rotor core in the axial direction along the axial direction.

[0083] In the above embodiment, the core plate 83 is an electromagnetic steel plate. However, the core plate can be a plate member other than an electromagnetic steel plate.

[0084] The present application can be used for a rotor that holds rotor magnets housed in magnet insertion holes by riveting.

Claims

1. A manufacturing method of a rotor for an IPM motor, the rotor for the IPM motor having a rotor core with a plurality of disc-shaped core plates stacked in a thickness direction and a magnet insertion hole capable of accommodating a rotor magnet, the manufacturing method characterized by comprising: a rotor magnet insertion process of inserting the rotor magnet into the magnet insertion hole; a rotor magnet positioning process of pushing a side end surface of the rotor magnet in an axial direction of the rotor magnet inserted into the magnet insertion hole to the other side in the axial direction in the magnet insertion hole to move the rotor magnet in the axial direction until the other side end surface of the rotor magnet coincides with an end surface of the other side in the axial direction of the rotor core; a first riveting process of riveting an end surface of the other side in the axial direction of the rotor core around the magnet insertion hole in the axial direction in a state where the rotor magnet is pushed to the other side in the axial direction by the rotor magnet positioning process; and a second riveting process of riveting an end surface of the one side in the axial direction of the rotor core around the magnet insertion hole in the axial direction to thereby fix the rotor magnet in the magnet insertion hole.

2. The manufacturing method of a rotor for an IPM motor according to claim 1, characterized in that, in the rotor magnet positioning process, the rotor core is disposed in a state where the axial direction coincides with an up-down direction, and the lower end surface of the rotor magnet is pushed upward.

3. The manufacturing method of a rotor for an IPM motor according to claim 1 or 2, characterized in that, in the rotor magnet positioning process, the side end surface of the rotor magnet in the axial direction is pushed to the other side in the axial direction in the magnet insertion hole by an elastic restoring force of an elastic member.

4. A manufacturing apparatus of a rotor for an IPM motor, the manufacturing apparatus of a rotor for an IPM motor being a manufacturing apparatus of a rotor for an IPM motor, the rotor for the IPM motor having a rotor core with a plurality of disc-shaped core plates stacked in a thickness direction and a magnet insertion hole capable of accommodating a rotor magnet, the manufacturing apparatus characterized by comprising: a rotor core support portion that supports the rotor core in a state where an axial direction coincides with an up-down direction; and a riveting mechanism that has a pin that rivets the rotor core in the axial direction, and a pin moving portion that moves the pin in the up-down direction with respect to the rotor core, the magnet pushing-up mechanism moves the rotor magnet in the up-down direction until the upper end surface of the rotor magnet coincides with an end surface of the upper side in the up-down direction of the rotor core.

5. The manufacturing apparatus of a rotor for an IPM motor according to claim 4, characterized in that, the magnet pushing-up mechanism is constituted by an elastic member that pushes the rotor magnet upward in the magnet insertion hole by an elastic restoring force.

6. The manufacturing apparatus of a rotor for an IPM motor according to claim 4 or 5, characterized in that, ​ ​ ​ ​ ​ ​ a magnet pushing-up mechanism that pushes up an end surface of a lower side of the rotor magnet to move the rotor magnet upward in the magnet insertion hole; ​ ​ ​ ​ ​ ​ ​ An upper side positioning member positions an upper side end surface of the rotor magnet inserted into the magnet insertion hole with respect to the rotor core. An upper side positioning member positions an upper side end surface of the rotor magnet inserted into the magnet insertion hole with respect to the rotor core.

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