Apparatus for manufacturing rotors for rotating electric machines and method for manufacturing rotors for rotating electric machines

Abstract

To prevent unwanted deformation to a radial outer side of a workpiece caused by an injection pressure at the time of an injection molding.SOLUTION: A present invention provides a rotor manufacturing device for a rotary electric machine, that comprises: a metal molding device that can set a workpiece of a rotor core for the rotary electric machine having a magnetic hole; a movable contact part that is arranged to the metal molding, and can be moved between a contact position contacted to a front surface on a radial outer side of the workpiece and a non-contact position separated from the front surface of the radial outer side of the workpiece; an injection device that can fill a material for an injection molding into the magnetic hole in the workpiece. The movable contact part can be moved along a radial direction of the workpiece set to the metal molding device.SELECTED DRAWING: Figure 12

Description

Technical Field

[0001] The present disclosure relates to a rotor manufacturing apparatus for a rotating electrical machine and a method for manufacturing a rotor for a rotating electrical machine.

Background Art

[0002] Regarding a manufacturing method of inserting a permanent magnet into a hole of a laminated core for a magnet-embedded rotor and filling a resin material between the hole and the permanent magnet, a technique is known in which a slide member is clamped in a state of contacting the outer peripheral portion of the laminated core during injection molding of the resin material.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional technology as described above, when the resin material is injection-molded, since the slide member is abutted against and fixed to the laminated core, when the injection pressure increases, there is a possibility that deformation of the laminated core outward in the radial direction due to the injection pressure cannot be prevented. Such a problem similarly occurs with respect to a rotor core (workpiece) for a rotating electrical machine in a form other than the laminated core.

[0005] Therefore, on one aspect, the present disclosure aims to prevent undesirable deformation of the workpiece outward in the radial direction due to the injection pressure during injection molding.

Means for Solving the Problems

[0006] On one aspect, a mold device capable of setting a workpiece of a rotor core for a rotating electrical machine having magnet holes, A movable contact portion is arranged in the mold apparatus and is movable between a contact position that abuts the radially outer surface of the workpiece and a non-contact position that is away from the radially outer surface of the workpiece. The workpiece comprises an injection device capable of filling the magnetic hole with material for injection molding. A rotor manufacturing apparatus for a rotating electric machine is provided, wherein the movable contact portion is movable along the radial direction of the workpiece set in the mold apparatus. [Effects of the Invention]

[0007] In one aspect, the present disclosure makes it possible to prevent undesirable radial outward deformation of the workpiece caused by the injection pressure during injection molding. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic cross-sectional view showing the cross-sectional structure of a motor according to one embodiment. [Figure 2] This is a cross-sectional view of the rotor (a cross-sectional view taken from a plane perpendicular to the axial direction). [Figure 3] This is an enlarged view of the portion related to one of the magnetic poles shown in Figure 2. [Figure 4] This is an enlarged view of the portion related to one of the magnetic poles, based on a modified example. [Figure 5] This flowchart schematically shows the manufacturing process of the rotor in this embodiment. [Figure 6] This is a plan view showing the initial workpieces prepared during the preparation process. [Figure 6A] This is an enlarged view of section Q1 in Figure 6. [Figure 7] This is a schematic diagram showing the state of the non-magnetic material inserted during the insertion process. [Figure 8] This diagram schematically shows the state of the bonded magnet material after it has been filled during the filling process. [Figure 9] This flowchart provides a schematic overview of one example of the filling process. [Figure 10] This diagram schematically shows a cross-sectional view of a workpiece set in the lower mold of a manufacturing device. [Figure 11] It is a diagram schematically showing the tightened state in a cross-sectional view. [Figure 12] It is a diagram schematically showing the state after the moving process in a cross-sectional view. [Figure 13] It is a diagram schematically showing the contact state of the movable contact part in a partial range in the circumferential direction. [Figure 14] It is an explanatory diagram of a movable contact mechanism according to another example. [Figure 15] It is a diagram schematically showing the state during the injection molding process in a cross-sectional view. [Figure 16] It is a diagram schematically showing the state of the force (reaction force, etc.) generated by the non-magnetic body during the injection molding process in an axial view. [Figure 17] It is an explanatory diagram of the bridge protection function by the movable contact part. [Figure 18] It is an explanatory diagram of the protection function of other parts by the movable contact part according to a modified example.

Embodiments for Carrying out the Invention

[0009] Hereinafter, each embodiment will be described in detail with reference to the accompanying drawings. Note that the dimensional ratios in the drawings are merely examples and are not limited thereto, and the shapes, etc. in the drawings may be exaggerated partially for the convenience of explanation.

[0010] FIG. 1 is a cross-sectional view schematically showing the cross-sectional structure of the motor 1 according to an embodiment. FIG. 2 is a cross-sectional view of the rotor 30 (a cross-sectional view by a plane perpendicular to the axial direction). In FIG. 2 and the like, for the sake of easy viewing, only some of the parts having the same attribute may be provided with reference signs.

[0011] In FIG. 1, the rotation shaft 12 of the motor 1 is shown. In the following description, the axial direction refers to the direction in which the rotation shaft (central axis) 12 of the motor 1 extends, and the radial direction refers to the radial direction centered on the rotation shaft 12. Therefore, the outer side in the radial direction refers to the side away from the rotation shaft 12, and the inner side in the radial direction refers to the side toward the rotation shaft 12. Also, the circumferential direction corresponds to the rotation direction around the rotation shaft 12.

[0012] The motor 1 may be a motor for vehicle drive used, for example, in a hybrid vehicle or an electric vehicle. However, the motor 1 may be used for any other application.

[0013] The motor 1 is of an inner rotor type, and the stator 21 is provided so as to surround the outer side in the radial direction of the rotor 30. The outer side in the radial direction of the stator 21 is fixed to the motor housing 10. The stator 21 includes, for example, a stator core 211 made of a laminated steel plate of an annular magnetic material, and a plurality of slots (not shown) in which coils 22 are wound are formed on the inner side in the radial direction of the stator core 211.

[0014] The rotor 30 is disposed on the inner side in the radial direction of the stator 21.

[0015] The rotor 30 includes a rotor core 32, a rotor shaft 34, end plates 35A and 35B, and bonded magnets 61 and 62.

[0016] The rotor core 32 is fixed to the surface on the outer side in the radial direction of the rotor shaft 34 and rotates integrally with the rotor shaft 34. The rotor core 32 has a shaft hole 320 (see FIG. 2), and the rotor shaft 34 is fitted into the shaft hole 320. The rotor shaft 34 is rotatably supported by the motor housing 10 via bearings 14a and 14b. Note that the rotor shaft 34 defines the rotation axis 12 of the motor 1.

[0017] The rotor core 32 is formed, for example, from laminated steel plates of annular magnetic material. In a modified example, the rotor core 32 may be formed from compacted magnetic powder. Bonded magnets 61 and 62 (see Figure 2) are arranged inside the rotor core 32. That is, the rotor core 32 has magnet holes 321 and 322 (see Figure 2) that penetrate in the axial direction, and the bonded magnets 61 and 62 are formed within the magnet holes 321 and 322. Each of the multiple bonded magnets 61 and 62 is formed by injection molding a bonded magnet material (hereinafter also simply referred to as "bonded magnet material") which is a mixture of magnetic powder and a binder. The injection molding method is arbitrary and may include, for example, transfer molding or resin injection by compression molding using a cylinder. Details of the method for forming the bonded magnets will be explained in relation to the manufacturing method described later.

[0018] As shown in Figure 2, the rotor core 32 has a rotationally symmetrical configuration with respect to the rotation axis 12 when viewed in the axial direction. In the example shown in Figure 2, the rotor core 32 is configured such that each pair of bonded magnets 61 and 62 overlaps every 45 degrees of rotation around the rotation axis 12.

[0019] In the example shown in Figure 2, the multiple bond magnets 61 and 62 are arranged in a roughly V-shape (a roughly V-shape with the radially outward side opening) with pairs of two types of bond magnets 61 and 62 when viewed in the axial direction. In this case, a common magnetic pole is formed between the pairs of bond magnets 61 and between the pairs of bond magnets 62. The multiple bond magnets 61 and 62 are arranged in a manner in which the south poles and north poles appear alternately in the circumferential direction. In this embodiment, there are eight magnetic poles, but the number of magnetic poles is arbitrary.

[0020] Although Figure 1 shows a motor 1 with a specific structure, the structure of the motor 1 is not limited to this specific structure. For example, in Figure 1, the rotor shaft 34 is hollow, but it may be solid.

[0021] Next, the rotor core 32 and bonded magnets 61 and 62 will be further described with reference to Figure 3 and subsequent figures. The following description will focus on the configuration for one magnetic pole, but the configurations for other magnetic poles may be similar.

[0022] Figure 3 is an enlarged view of the portion related to one of the magnetic poles shown in Figure 2. The configuration related to one of the magnetic poles is basically symmetrical with respect to the d-axis. Hereafter, "outer circumferentially" refers to the side away from the d-axis. The d-axis is the direction of the magnetic field generated by the permanent magnets (i.e., bonded magnets 61 and 62) placed on the rotor 30.

[0023] The rotor core 32 has a radially outer magnet hole 321 (hereinafter also referred to as the "first magnet hole 321") and a radially inner magnet hole 322 (hereinafter also referred to as the "second magnet hole 322").

[0024] The first magnet holes 321 are formed in pairs in a substantially V-shape (a substantially V-shape with the radially outward side opening). However, in modified examples, the first magnet holes 321 may be formed in pairs in a straight line, or only one may be formed in a straight line (a straight line perpendicular to the d-axis). A bonded magnet 61 is provided in each of the first magnet holes 321. Gaps (cavities) are formed in the first magnet holes 321 at both longitudinal ends of the bonded magnet 61. These gaps function as flux barriers. In this embodiment, a non-magnetic material 71 is placed in the gap related to the flux barrier. The non-magnetic material 71 is provided adjacent to the bonded magnet 61. For example, of the non-magnetic materials 71 on both sides of the bonded magnet 61, the radially outward non-magnetic material 71 abuts (in this case, surface contact) against the radially outward end face of the bonded magnet 61. The non-magnetic material 71 may be provided in such a manner that it fills the entire flux barrier portion, or it may be provided in such a manner that a cavity remains in a part of the flux barrier portion. Further details of the non-magnetic material 71 will be described in relation to the manufacturing method described later.

[0025] The second magnet holes 322 are provided radially inward from the first magnet holes 321. The two second magnet holes 322 are paired and formed in a substantially V-shape (a substantially V-shape with the radially outward side opening). The pair of second magnet holes 322 have a wider circumferential extension than the pair of first magnet holes 321. Bonded magnets 62 are provided in each of the second magnet holes 322. Gaps (cavities) are formed in the second magnet holes 322 at both longitudinal ends of the bonded magnets 62. These gaps function as flux barriers. In this embodiment, a non-magnetic material 72 is placed in the gap related to the flux barrier. The non-magnetic material 72 is provided adjacent to the bonded magnets 62. The configuration of the non-magnetic material 72 itself may be the same as that of the non-magnetic material 71 described above.

[0026] The rotor core 32 has such a first magnet hole 321 and a second magnet hole 322, and has three parts 3211, 3212, and 3213 (hereinafter also referred to as the first part 3211, the second part 3212, and the third part 3213) that are connected only radially via a bridge portion.

[0027] Specifically, the first portion 3211 extends radially outward from the first magnet hole 321. The first portion 3211 forms part of the outer circumferential surface 328 of the rotor core 32.

[0028] The second portion 3212 extends circumferentially from the second magnet hole 322 to the outer circumferential surface 328 of the rotor core 32, passing between the second magnet hole 322 and the first magnet hole 321. On both circumferential sides of the first portion 3212, the second portion 3212 forms a part of the outer circumferential surface 328 of the rotor core 32. The second portion 3212 forms a magnetic path for the q-axis magnetic flux. Specifically, the q-axis magnetic flux flows from one end of the second portion 3212 to the other, passing between the second magnet hole 322 and the first magnet hole 321.

[0029] The third portion 3213 extends radially inward from the second magnet hole 322, with both sides extending circumferentially to the outer circumferential surface 328 of the rotor core 32. On both sides circumferentially of the second portion 3212, the third portion 3213 forms a part of the outer circumferential surface 328 of the rotor core 32.

[0030] Furthermore, the rotor core 32, having these three parts 3211, 3212, and 3213, has multiple bridge sections 41, 42, 43, and 44 connecting the three parts 3211, 3212, and 3213.

[0031] The bridge portion 41 (hereinafter also referred to as the "first bridge portion 41") supports the first portion 3211 radially outward relative to the second portion 3212. The first bridge portions 41 are provided in pairs on both sides (outward in the circumferential direction) of the first portion 3211. The first bridge portions 41 extend between the outer circumferential surface 328 of the rotor core 32 and the first magnet hole 321.

[0032] The bridge portion 42 (hereinafter also referred to as the "second bridge portion 42") supports the second portion 3212 radially outward from the third portion 3213. The second bridge portions 42 are provided in pairs on both sides (outward in the circumferential direction) of the second portion 3212. The second bridge portions 42 extend between the outer peripheral surface 328 of the rotor core 32 and the second magnet hole 322.

[0033] The bridge portion 43 supports the first portion 3211 on the d-axis relative to the second portion 3212.

[0034] The bridge portion 44 supports the second portion 3212 on the d-axis relative to the third portion 3213.

[0035] The configuration of the bonded magnets 61 and 62 in the rotor core 32 is arbitrary and not limited to the configurations shown in Figures 2 and 3. For example, in the examples shown in Figures 2 and 3, a bonded magnet 61 is provided, but as in the modified rotor 30A (rotor core 32A) shown in Figure 4, the bonded magnet 61 may be omitted. In this case, the first part 3211 and the second part 3212 are integrated, and the first bridge part 41 is substantially eliminated. Alternatively, a further bonded magnet may be arranged radially inward from the bonded magnet 62 in a manner in which the third part 3213 becomes the magnetic path for the q-axis magnetic flux.

[0036] Next, we will explain in detail the manufacturing method of the rotor core 32 (and the rotor core 32A) as described above.

[0037] Figure 5 is a flowchart illustrating the general flow of the manufacturing method for the rotor 30 in this embodiment. Figures 6 to 8 are explanatory diagrams of specific steps in the manufacturing method shown in Figure 5.

[0038] This manufacturing method first includes a preparation step (step S500) to prepare the rotor core 32 workpiece. As described above, the rotor core 32 has magnet holes 321 and 322. Figure 6 is a plan view showing the initial workpiece (rotor core 32) prepared in the preparation step. Figure 6A is an enlarged view of part Q1 in Figure 6. At the preparation stage, as shown in Figure 6, nothing is placed in the magnet holes 321 and 322.

[0039] Next, this manufacturing method includes a preparation step (step S502) for preparing non-magnetic materials 71 and 72. The non-magnetic materials 71 and 72 have sizes corresponding to the flux barrier portions in the magnet holes 321 and 322 to be inserted. Figure 6A shows the space SC0 that will become the bonded magnet 62 described above, and the other spaces on either side of it (spaces that will become the flux barrier portions) SC1 and SC2 within the magnet hole 322. Note that in Figure 6A, for illustrative purposes, the spaces SC0, SC1 and SC2 are shown slightly inward from the hole edge 3221 of the magnet hole 3222, but the hole edge 3221 defines the spaces SC0, SC1 and SC2.

[0040] Next, this manufacturing method includes an insertion step (step S504) in which non-magnetic materials 71 and 72 are inserted into the spaces SC1 and SC2, which are flux barrier portions that are part of the magnetic holes 321 and 322, respectively. Figure 7 is a schematic diagram showing the state of the non-magnetic material 72 inserted in the insertion step (state in the magnetic hole 322).

[0041] Next, this manufacturing method includes a filling step (step S510) in which bonded magnet material is filled into the portions of the magnet holes 321 and 322 adjacent to the non-magnetic materials 71 and 72, using a manufacturing apparatus 100 described later. The filling step (step S510) may be performed while an orientation magnetic field is applied. Figure 8 is a schematic diagram showing the state of the bonded magnet material 90 filled in the filling step (state in the magnet hole 322). Details of the filling step will be described later with reference to Figure 9 and subsequent figures.

[0042] Furthermore, this manufacturing method includes other post-processing steps (step S520). These post-processing steps may include, for example, the assembly of end plates 35A, 35B, rotor shaft 34, etc.

[0043] Next, we will describe the details of the filling process (step S510) in this manufacturing method, along with the configuration of a manufacturing apparatus 100 suitable for realizing the filling process.

[0044] Figure 9 is a flowchart schematically showing an example of the filling process (step S510). Figures 10 to 13, 15 and 16 are explanatory diagrams of specific steps in this filling process. Figure 14 is an explanatory diagram of the movable contact mechanism 120A in another example. In Figures 10 to 12, 15 and 16, the Z direction corresponding to the vertical direction is defined, with Z1 corresponding to the upper side and Z2 corresponding to the lower side. Also, in Figures 10 to 12 and 15, the central axis I of the manufacturing apparatus 100 is shown by a dashed line. Note that the manufacturing apparatus 100 may be substantially rotationally symmetrical around the central axis I.

[0045] This filling process first includes a setting process (step S5102) in which a rotor core 32 (hereinafter also referred to as "workpiece W") with non-magnetic materials 71 and 72 assembled to it is set in the lower mold 110 of the manufacturing apparatus 100. Figure 10 is a schematic cross-sectional view showing the state in which the workpiece W is set in the lower mold 110 of the manufacturing apparatus 100. In Figure 10, the cross-sectional view of the workpiece W is shown including the rotation axis 12 of the rotor core 32 and passing through the space SC0 (the same applies to Figure 11 and so on). The workpiece W may be set in the lower mold 110 such that the rotation axis 12 of the rotor core 32 coincides with the central axis I of the manufacturing apparatus 100. Therefore, in the following description, the axial direction refers to the direction in which the rotation axis (center of rotation) 12 or central axis I of the motor 1 extends, and the radial direction refers to the radial direction centered on the rotation axis 12 or central axis I. Therefore, the radially outward direction refers to the side away from the rotation axis 12 or the central axis I, and the radially inward direction refers to the side toward the rotation axis 12 or the central axis I. Furthermore, the circumferential direction corresponds to the direction of rotation around the rotation axis 12 or the central axis I.

[0046] In this embodiment, the manufacturing apparatus 100 includes a lower mold 110, a movable contact mechanism 120 (described later with reference to Figure 12, etc.), an upper mold 130 (described later with reference to Figure 11), and an injection molding apparatus 140 (described later with reference to Figure 15). The lower mold 110 may have, for example, a support surface 111 in a horizontal plane, and the workpiece W may be supported such that the axial end face of the rotor core 32 is in surface contact with the support surface 111.

[0047] Next, the filling process includes a mold clamping process (step S5104) in which the upper mold 130 of the manufacturing apparatus 100 is lowered (see arrow R12 in Figure 11) and the rotor core 32 of the workpiece W is pressed in the axial direction. Specifically, in this filling process, a mold clamping state is formed on the workpiece W by the upper mold 130 and the lower mold 110. In the mold clamping state, a state is achieved in which the rotor core 32 of the workpiece W is pressed in the axial direction with the target pressure. Therefore, the axial distance between the upper mold 130 and the lower mold 110 in the mold clamping state may change depending on the variation in the axial dimensions (i.e., stacking thickness) of the rotor core 32. Figure 11 is a schematic diagram showing the mold clamping state in cross-sectional view. In this embodiment, the manufacturing apparatus 100 is implemented in a manner that includes a mold clamping device for an injection molding machine related to the injection molding apparatus 140, and the upper mold 130 includes structures such as ports for injecting bonded magnet material 90 into the space SC0, as schematically shown in Figure 11.

[0048] Next, the filling process includes a moving step (step S5106) to move the movable contact portion 122 of the movable contact mechanism 120 to a position where it contacts the outer circumferential surface of the rotor core 32, as schematically shown by arrow R13 in Figure 12. Figure 12 is a schematic cross-sectional view showing the state after the moving step (the state in which the movable contact portion 122 contacts the outer circumferential surface of the rotor core 32). In this embodiment, the movable contact portion 122 is positioned between the upper mold 130 and the lower mold 110 in the vertical direction. The movable contact portion 122 is configured to be able to move translationally in a horizontal plane toward the central axis I. In this embodiment, the movable contact portion 122 is supported by the lower mold 110 in such a manner that it can slide on the support surface 111 (horizontal plane) of the lower mold 110, as schematically shown in Figures 10 to 12. However, in a modified example, the movable contact portion 122 may be supported by the lower mold 110 in such a manner that it can slide on the support surface 131 (horizontal plane) of the upper mold 130.

[0049] The movable contact portion 122 is movable between a contact position (see Figure 12) in which it contacts the radially outer surface (outer peripheral surface) of the rotor core 32 of the workpiece W, and a non-contact position (see Figures 10 and 11) away from the radially outer surface of the rotor core 32 of the workpiece W. For this purpose, the movable contact mechanism 120 includes an actuator 124 for moving the movable contact portion 122. The type of actuator 124 is arbitrary and may be, for example, an air cylinder or a motor. If the actuator 124 is a motor, the movable contact mechanism 120 may include a mechanism (for example, a screw mechanism) that converts the rotation of the motor into linear motion.

[0050] In the example shown in Figure 10, the actuator 124 of the movable contact mechanism 120 generates a load in the horizontal plane and toward the central axis I, but it is not limited to this. For example, as in the other example shown in Figure 14, an actuator 124A that generates a load in the vertical direction may be used. In this case, the movable contact mechanism 120A may include a cam mechanism that converts the vertical movement based on the vertical load from the actuator 124A (see arrow R140) into movement in the horizontal plane and toward the central axis I (see arrow R141), as schematically shown in Figure 14.

[0051] In this embodiment, the movable contact portion 122 is movable even in the mold clamping state described above. That is, in the mold clamping state, the movable contact portion 122 is not clamped between the upper mold 130 and the lower mold 110, and is still able to move translationally in the horizontal plane toward the central axis I. For this purpose, the movable contact portion 122 may have an upper surface 1220 (see Figure 12) located below the upper mold 130. That is, the upper surface 1220 of the movable contact portion 122 has a vertical clearance Δ with respect to the support surface 131 of the upper mold 130. The magnitude of the clearance Δ is any value greater than 0, but may be adjusted according to the variation in the vertical dimensions (i.e., stacking thickness) of the rotor core 32. That is, even when the vertical dimensions of the rotor core 32 reach their lower limit, the clearance Δ may be adjusted to be significantly greater than 0.

[0052] In this way, according to this embodiment, by making the movable contact portion 122 movable even in the mold clamped state, it is possible to prevent undesirable radial outward deformation of the rotor core 32 caused by injection pressure during injection molding. Furthermore, in the mold clamped state, as described above, a clearance Δ is secured between the upper mold 130 and the movable contact portion 122, so that the rotor core 32 can be maintained in a state of axial pressure with the target pressure regardless of the movement of the movable contact portion 122, throughout the mold clamped state. Therefore, according to this embodiment, it is possible to apply axial pressure to the rotor core 32 with the target pressure while preventing undesirable radial outward deformation of the rotor core 32 caused by injection pressure during injection molding.

[0053] Preferably, the movable contact portion 122 makes surface contact with the outer circumferential surface 328 of the rotor core 32 at the contact position. Furthermore, preferably, the movable contact portion 122 makes surface contact with the outer circumferential surface 328 of the rotor core 32 along its entire axial length at the contact position. This effectively reduces stress concentration in the bridge portions 41 and 42 that may occur due to injection pressure, as will be described later with reference to Figures 16 and 17. The movable contact portion 122 may also contact the outer circumferential surface 328 of the rotor core 32 over its entire circumference around the central axis I. Figure 13 is a schematic diagram showing the contact state of the movable contact portion 122 in a portion of the circumferential range, and is a cross-sectional view taken when cut by a plane perpendicular to the axial direction. As shown in Figure 13, the movable contact portion 122 may contact the entire circumferential range of the outer circumferential surface 328 of the rotor core 32 where the bridge portions 41 and 42 are located. In the example shown in Figure 13, fixtures 125 are provided on both sides of the movable contact portion 122 in the circumferential direction. The fixtures 125 may have contact surfaces at radial positions corresponding to the maximum allowable outer diameter of the rotor core 32. In this case, the movable contact portion 122 functions radially inward from the contact surfaces of the fixtures 125.

[0054] In this filling process, the transfer process (step S5106) is performed after the mold clamping process (step S5104), but it may also be performed before the mold clamping process (step S5104).

[0055] Next, this manufacturing method includes an injection molding step (step S5108) in which bonded magnet material is injected into the portions of the magnet holes 321 and 322 adjacent to the non-magnetic materials 71 and 72. Figure 15 is a schematic cross-sectional view showing the state during the injection molding process. In Figure 15, arrow R15 schematically shows the flow pattern of the bonded magnet material 90 into the space SC0.

[0056] This manufacturing method includes a curing step (step S5110) that follows the injection molding step (step S5108) to cure the bonded magnet material 90. The curing step may be a heating step that heat-cures the bonded magnet material 90.

[0057] This manufacturing method includes an adjustment step (step S5112) in parallel with the injection molding step (step S5108) to adjust the position of the movable contact portion 122 (radial position with respect to the central axis I). The adjustment step includes maintaining the position of the movable contact portion 122 in the contact position. The contact position, with respect to the central axis I (or the rotation axis 12 of the rotor core 32), may be a position corresponding to the outer diameter of the rotor core 32. The contact position to be adjusted does not need to be a single point, but may be defined by a specific position range (a range in which the contact state is maintained) according to the tolerance of the outer diameter of the rotor core 32. For example, the adjustment step may include maintaining the position of the movable contact portion 122 so that it does not deviate from the specific position range. Furthermore, in order to accommodate such variations in contact position, the portion of the upper mold 130 that contacts the axial end face of the rotor core 32 may have an outer diameter that is slightly smaller (for example, an outer diameter that is about 0.1 mm to 1 mm smaller) than the lower limit of the outer diameter that the rotor core 32 can take.

[0058] The adjustment step (step S5112) may include applying a radially inward pressing force along the radial direction to the radially outer surface of the workpiece (i.e., the outer circumferential surface 328 of the rotor core 32) via the movable contact portion 122. In this case, the pressing force may be a pressing force to maintain the position of the movable contact portion 122 within a specific position range. For example, the pressing force may change in conjunction with changes in the injection pressure of the injection molding process (step S5108) during the injection molding process.

[0059] The adjustment process (step S5112) may also be performed during the curing process (step S5110) that follows the injection molding process (step S5108).

[0060] Next, this manufacturing method includes a step (step S5114) in which, once the bonded magnet material 90 has hardened, the upper mold 130 and the movable contact portion 122 are moved to their initial positions. The initial position of the movable contact portion 122 corresponds to the non-contact position described above (see Figures 10 and 11).

[0061] Next, this manufacturing method ends by removing the workpiece (step S5116).

[0062] Next, with reference to Figures 16 and 17, further effects of this embodiment will be described.

[0063] Figure 16 is a schematic diagram showing the state of forces (reaction forces, etc.) generated by the non-magnetic material 72 during the injection molding process (step S5108) in an axial view. Figure 17 is an explanatory diagram of the bridge protection function by the movable contact portion 122, and is a schematic diagram showing the state of the pressing force of the movable contact portion 122 during the injection molding process (and adjustment process) in an axial view, in the same view as Figure 13.

[0064] As shown in Figure 16, when the bonded magnet material 90 is injection molded, the bonded magnet material 90 fills the space SC0 with a fluid pressure corresponding to the injection pressure. At this time, a pressure corresponding to the injection pressure is generated in the non-magnetic material 72 from the bonded magnet material 90, as schematically shown by pressure p91 in Figure 16. This pressure p91 acts on the bridge portion 42 (and similarly on the bridge portion 41) and becomes a source of stress in the bridge portion 42.

[0065] In contrast, according to this embodiment, as described above, the radially inward pressing force from the movable contact portion 122 can function as a resistance force against the injection pressure, as schematically shown by arrow F13 in Figures 15 and 17. As a result, the force transmitted to the bridge portions 41 and 42 via the non-magnetic materials 71 and 72 (a force directed radially outward) from the bonded magnet material to the non-magnetic materials 71 and 72 due to the injection pressure can be reduced. As a result, stress concentration in the bridge portions 41 and 42 that may occur due to the injection pressure can be reduced. In other words, even if the injection pressure of the bonded magnet material is increased, stress concentration in the bridge portions 41 and 42 can be reduced, making it possible to use bonded magnet materials with relatively low fluidity (and therefore requiring injection at a relatively high injection pressure) but good magnetic properties (for example, bonded magnet materials with a high magnetic powder content), and thus improving the magnetic properties of the motor 1.

[0066] Incidentally, in a configuration like the motor 1 of this embodiment, where bonded magnets 61 and 62 are arranged symmetrically with respect to the d-axis (see Figures 3 and 4), the portion of the first part 3211 on the d-axis is also prone to deformation radially outward due to the injection pressure from the bonded magnet material 90. Taking this into consideration, in a modified example, as shown in Figure 18, for example, another movable contact part 122B may be provided, which has a different contact range with respect to the rotor core 32 from the movable contact part 122. The movable contact part 122B contacts the rotor core 32 in a circumferential range centered on the d-axis. In this case, the movable contact part 122B can apply the same effect as the movable contact part 122 on the bridge parts 41 and 42 to the portion of the first part 3211 of the rotor core 32 on the d-axis. That is, stress concentration in the portion of the first part 3211 on the d-axis that may occur due to injection pressure can be reduced. In the example shown in Figure 18, both the movable contact portion 122 and the movable contact portion 122B are provided, but it is also possible to provide only the movable contact portion 122B.

[0067] Although each embodiment has been described in detail above, the invention is not limited to any particular embodiment, and various modifications and changes are possible within the scope described in the claims. Furthermore, it is possible to combine all or more of the components of the embodiments described above.

[0068] For example, in the above-described embodiment, the movable contact mechanism 120 (and the movable contact mechanism 120A) is applied in the filling process (injection molding process) of the bonded magnet material 90, but it is not limited to this. The movable contact mechanism 120 (and the movable contact mechanism 120A) can also be applied to, for example, the injection molding process (not shown) of a resin material for fixing a sintered magnet in a magnet hole. In addition, in the above-described embodiment, the non-magnetic materials 71 and 72 are prepared in the preparation process (step S502), but they may also be formed by injection molding prior to the filling process (injection molding process) of the bonded magnet material 90. In this case, the movable contact mechanism 120 (and the movable contact mechanism 120A) can also be applied to the injection molding process (not shown) for the non-magnetic materials 71 and 72. [Explanation of symbols]

[0069] 1...Motor (rotating electric machine), 32, 32A...Rotor core (rotor core for rotating electric machine, laminated iron core), 3211...First part (rotor core part), 3212...Second part (rotor core part), 3213...Third part (rotor core part), 321, 322...Magnet hole, 41, 42...Bridge part (outer bridge), 71, 72...Non-magnetic material, 61, 62...Bonded magnet, 100...Manufacturing equipment (rotor manufacturing equipment for rotating electric machine), 130...Upper mold (mold equipment), 110...Lower mold (mold equipment), 122...Movable contact part, 140...Injection molding equipment (injection equipment), W...Workpiece

Claims

1. A mold device capable of setting a workpiece for a rotor core of a rotating electric machine equipped with a magnetic hole, A movable contact portion is arranged in the mold apparatus and is movable between a contact position that abuts the radially outer surface of the workpiece and a non-contact position that is away from the radially outer surface of the workpiece. The workpiece comprises an injection device capable of filling the magnetic hole with material for injection molding. The movable contact portion is made movable along the radial direction of the workpiece set in the mold device during injection molding by the injection device. The workpiece is an outer peripheral bridge adjacent to the radially outer side of the magnet hole, and has an outer peripheral bridge connecting the rotor core portions separated by the magnet hole. Rotor manufacturing apparatus for a rotating electric machine, wherein the movable contact portion is arranged to be limited to a specific range corresponding to at least one of the range of the outer circumferential bridge and the range of the d-axis related to each magnetic pole of the rotating electric machine in the circumferential direction.

2. The rotor manufacturing apparatus for a rotating electric machine according to Claim 1, wherein the movable contact portion is capable of contacting the workpiece in the circumferential range where the outer peripheral bridge is located, out of the entire circumference of the workpiece.

3. The rotor manufacturing apparatus for a rotating electric machine according to claim 1, wherein the movable contact portion is capable of contacting the workpiece in a circumferential range centered on the d-axis within the entire circumference of the workpiece.

4. The rotor core for the aforementioned rotating electric machine is in the form of a laminated iron core. The mold apparatus includes an upper mold and a lower mold that are movable relative to each other in the vertical direction, and the workpiece can be set between the upper mold and the lower mold in the vertical direction. The injection device is capable of filling the injection molding material in the mold clamped state by the upper and lower molds of the mold device. The movable contact portion is positioned vertically between the upper mold and the lower mold, and is movable along the radial direction of the workpiece when the mold device is clamped, as described in claim 1, for the rotor manufacturing apparatus for a rotating electric machine.

5. The rotary electric machine rotor manufacturing apparatus according to claim 4, wherein the movable contact portion has a gap in the vertical direction with respect to the upper mold or the lower mold when the mold clamping state of the mold apparatus.

6. The rotor manufacturing apparatus for a rotating electric machine according to claim 4, wherein the movable contact portion is supported by the upper mold or the lower mold in such a manner that it can translate toward the central axis of the workpiece on the horizontal plane of the upper mold or the horizontal plane of the lower mold.

7. A setting process in which a rotor core for a rotating electric machine, equipped with magnetic holes, is set in a mold device, Following the setting step, a moving step is performed to move the movable contact portion, thereby transitioning from a non-contact state, where it is separated from the radially outer surface of the workpiece, to a contact state, where it is in contact with the radially outer surface of the workpiece. An injection molding step in which, in the contact state of the movable contact portion, an injection molding material is filled into the magnetic hole in the workpiece, An adjustment step, performed in parallel with the injection molding step, includes adjusting the position of the movable contact portion so that the movable contact portion is maintained in the contact state, or adjusting the pressing force applied to the radially outer surface of the workpiece in the contact state, The workpiece is an outer peripheral bridge adjacent to the radially outer side of the magnet hole, and has an outer peripheral bridge connecting the rotor core portions separated by the magnet hole. A method for manufacturing a rotor for a rotating electric machine, wherein the movable contact portion is arranged to be limited to a specific range corresponding to at least one of the range of the outer circumferential bridge and the range of the d-axis related to each magnetic pole of the rotating electric machine in the circumferential direction.

8. The workpiece is an outer peripheral bridge adjacent to the radially outer side of the magnet hole, and has an outer peripheral bridge connecting the rotor core portions separated by the magnet hole. The method for manufacturing a rotor for a rotating electric machine according to claim 7, wherein the contact state includes a state in which the movable contact portion contacts the circumferential range in which the outer peripheral bridge is arranged within the entire circumference of the workpiece.

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