Rotor manufacturing method and rotor manufacturing apparatus for rotor

Abstract

The invention relates to a method for manufacturing a rotor for a rotating electric machine and an apparatus for manufacturing a rotor for a rotating electric machine. The method for manufacturing a rotor for a rotary electric machine includes: a heating step of heating a workpiece in a non-placed state in which an orientation magnetic field applying device is separated from the workpiece of a rotor core for a rotary electric machine provided with a magnet hole; a placement step in which, after the heating step, a placement state in which the orientation magnetic field applying device is brought closer to the workpiece than in a non-placement state is formed; and an injection molding step of applying the orientation magnetic field from the orientation magnetic field applying device to the workpiece in the placed state, and filling the magnet hole of the workpiece with a material for bonding the magnet.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a rotor for a rotating electric machine and an apparatus for manufacturing a rotor for a rotating electric machine. Background Art

[0002] There is a well-known technology, that is, assembling an orientation magnetic field applying device (orientation yoke, etc.) into a mold, applying an orientation magnetic field to a workpiece (a rotor workpiece for a rotating electric machine) molded with the mold by the orientation magnetic field applying device, and injection molding the material for bonding the magnet into the magnet hole of the workpiece.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2017-34765

[0004] However, in the prior art as described above, when the workpiece is heated together with the mold during injection molding, the orientation magnetic field applying device is assembled in the mold, so there is a problem that the orientation magnetic field applying device is also heated through the mold, and the thermal efficiency is low. In addition, from the perspective of generating a relatively high magnetic field required for magnetic field orientation, the high temperature of the orientation magnetic field applying device is also disadvantageous. Summary of the invention

[0005] Therefore, in one aspect, an object of the present invention is to reduce the amount of heat that is conducted to an alignment magnetic field applying device, out of the heat generated by a heating device for heating a workpiece or the like during injection molding.

[0006] In one aspect, a method for manufacturing a rotor for a rotating electric machine is provided, which includes the following steps: a heating step, heating the workpiece in a non-placed state in which an orientation magnetic field applying device is away from the workpiece of a rotor core for a rotating electric machine having a magnet hole; a placing step, after the heating step, forming a placing state in which the orientation magnetic field applying device is closer to the workpiece than in the non-placed state; and an injection molding step, applying an orientation magnetic field from the orientation magnetic field applying device to the workpiece in the placing state, and filling the magnet hole of the workpiece with a material for bonding a magnet.

[0007] In one aspect, according to the present invention, the amount of heat generated by a heating device for heating a workpiece or the like during injection molding that is conducted to an alignment magnetic field applying device can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a cross-sectional view schematically showing the cross-sectional structure of a motor according to an embodiment.

[0009] Figure 2 It is a cross-sectional view of the rotor (a cross-sectional view taken along a plane perpendicular to the axial direction).

[0010] Figure 3 yes Figure 2 An enlarged view of a portion of one magnetic pole is shown.

[0011] Figure 4 This is a flowchart schematically showing the flow of the method for manufacturing the rotor of Example 1.

[0012] Figure 5 yes Figure 4 An explanatory diagram of the clamping step of the manufacturing method shown.

[0013] Figure 6 yes Figure 4 An explanatory diagram of a heating step in the manufacturing method shown.

[0014] Figure 7 yes Figure 4 An explanatory diagram of the placement step (part 1) in the manufacturing method shown.

[0015] Figure 8 yes Figure 4 An explanatory diagram of the placement step (part 2) in the manufacturing method shown.

[0016] Fig. 9 yes Figure 4 An explanatory diagram of the injection molding step in the case of only unipolar orientation in the manufacturing method shown.

[0017] Fig.10 yes Figure 4 An explanatory diagram of the injection molding step in the case of omnipolar orientation in the manufacturing method shown.

[0018] Fig.11 yes Figure 4 An explanatory diagram of the removal step in the manufacturing method shown.

[0019] Fig.12 It is an explanatory diagram of one state of an orientation magnetic field applying device of a manufacturing apparatus according to a modified example.

[0020] Fig.13 It is an explanatory diagram of the placement state of the alignment magnetic field applying device of the manufacturing apparatus of the modified example.

[0021] Fig.14 It is an explanatory diagram of another state of the alignment magnetic field applying device of the manufacturing apparatus according to the modified example.

[0022] Fig.15 This is a flow chart briefly showing the flow of the method for manufacturing a rotor according to the second embodiment.

[0023] Fig.16 yes Fig.15 An explanatory diagram of the temperature raising step in the manufacturing method shown.

[0024] Fig.17 yes Fig.15 An explanatory diagram of the arrangement step in the manufacturing method shown.

[0025] Fig.18 yes Fig.15 An explanatory diagram of the mold clamping step and the placing step in the manufacturing method shown.

[0026] Fig.19 yes Fig.15 An explanatory diagram of the injection molding step in the manufacturing method shown.

[0027] Fig. 20 yes Fig.15 An explanatory diagram of a mold opening step and a retracting step in the manufacturing method shown.

[0028] Fig.21 This is an explanatory diagram of the manufacturing method and manufacturing apparatus of Example 3 (part 1).

[0029] Fig. 22 This is an explanatory diagram of the manufacturing method and manufacturing apparatus of Example 3 (part 2).

[0030] Fig.23 This is an explanatory diagram of the manufacturing method and manufacturing apparatus of Example 3 (Part 3). DETAILED DESCRIPTION

[0031] Hereinafter, each embodiment will be described in detail with reference to the drawings. The dimensional ratios in the drawings are merely examples and are not limited thereto. In addition, for the sake of convenience of description, the shapes and the like in the drawings may be partially exaggerated.

[0032] Figure 1 It is a cross-sectional view schematically showing the cross-sectional structure of a motor 1 according to an embodiment. Figure 2 is a cross-sectional view of the rotor 30 (a cross-sectional view taken along a plane perpendicular to the axial direction). Figure 2 In the foregoing, for the sake of easy understanding, among the parts having the same attribute that exist in plurality, only a part thereof may be denoted by a reference numeral.

[0033] exist Figure 1 The middle figure shows the rotating shaft 12 of the motor 1. In the following description, the axial direction refers to the direction in which the rotating shaft (rotation center) 12 of the motor 1 extends, and the radial direction refers to the radial direction centered on the rotating shaft 12. Therefore, the radial outer side refers to the side away from the rotating shaft 12, and the radial inner side refers to the side toward the rotating shaft 12. In addition, the circumferential direction corresponds to the rotation direction around the rotating shaft 12.

[0034] The motor 1 may be a vehicle driving motor used in, for example, a hybrid vehicle or an electric vehicle, but the motor 1 may be used for any other purpose.

[0035] The motor 1 is an inner rotor type, and is provided with a stator 21 surrounding the radially outer side of the rotor 30. The radially outer side of the stator 21 is fixed to the motor housing 10. The stator 21 has a stator core 211 composed of, for example, an annular magnetic laminated steel plate, and a plurality of slots (not shown) for winding the coil 22 are formed on the radially inner side of the stator core 211.

[0036] The rotor 30 is arranged radially inside the stator 21 .

[0037] The rotor 30 includes a rotor core 32 , a rotor shaft 34 , end plates 35A and 35B, and bond magnets 61 and 62 .

[0038] The rotor core 32 is fixed to the radially outer surface of the rotor shaft 34 and rotates integrally with the rotor shaft 34. The rotor core 32 has an axial hole 320 (see Figure 2 ), 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. In addition, the rotor shaft 34 divides the rotating shaft 12 of the motor 1.

[0039] The rotor core 32 is formed of, for example, a stacked steel plate of annular magnetic bodies. In a modified example, the rotor core 32 may be formed of a powder compact obtained by compressing and fixing magnetic powder. Bonded magnets 61 and 62 are arranged inside the rotor core 32 (see Figure 2 That is, the rotor core 32 has magnet holes 321 and 322 that penetrate in the axial direction (see Figure 2 ), bonded magnets 61, 62 are formed in magnet holes 321, 322. Each of the plurality of bonded magnets 61, 62 is formed by injection molding a material for bonded magnets (hereinafter referred to as "bonded magnet material") obtained by mixing magnet powder and a binder (e.g., resin material). The injection molding method is arbitrary, and may include, for example, transfer molding, resin injection using compression molding with a cylinder, etc. The details of the method for forming the bonded magnet will be described in conjunction with the manufacturing method described later.

[0040] like Figure 2 As shown, the rotor core 32 has a rotationally symmetrical shape around the rotation axis 12 when viewed in the axial direction. Figure 2 In the example shown, each set of bonded magnets 61 and 62 overlaps each other every time the rotor core 32 rotates 45 degrees around the rotating shaft 12 .

[0041] exist Figure 2In the example shown, the plurality of bonded magnets 61, 62 are arranged in pairs in a roughly V-shape (a roughly V-shape with radially outer sides open) when viewed in the axial direction. In this case, a common magnetic pole is formed between a pair of bonded magnets 61 and a pair of bonded magnets 62. In addition, the plurality of bonded magnets 61, 62 are arranged in a manner that the S pole and the N pole appear alternately in the circumferential direction. In addition, in the present embodiment, the number of magnetic poles is eight, and the number of magnetic poles is arbitrary.

[0042] In addition, although Figure 1 The motor 1 having a specific structure is shown in FIG. 1 , but the structure of the motor 1 is not limited to the above-mentioned specific structure. Figure 1 In the embodiment, the rotor shaft 34 is hollow, but may also be solid.

[0043] Next, refer to Figure 3 The rotor core 32 and the bonded magnets 61 and 62 will be further described in the following figures. Although the structure of one magnetic pole is described below, the structures of the other magnetic poles are also described in the same manner.

[0044] Figure 3 yes Figure 2 An enlarged view of a portion of one magnetic pole is shown. The structure of one magnetic pole is basically symmetrical with respect to the d-axis. Hereinafter, the circumferential outer side refers to the side away from the d-axis.

[0045] The rotor core 32 includes a radially outer magnet hole 321 (hereinafter also referred to as a “first magnet hole 321 ”) and a radially inner magnet hole 322 (hereinafter also referred to as a “second magnet hole 322 ”).

[0046] For the first magnet holes 321, two are paired and formed into a roughly V-shape (a roughly V-shape that is opened radially outward). However, in a modified example, the first magnet holes 321 may be two paired and formed into a straight line, or only one may be formed into 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. In addition, in the first magnet hole 321, a gap (hole) is formed at both ends of the bonded magnet 61 in the long side direction. The gap functions as a magnetic flux barrier. A non-magnetic body 71 may be arranged in the gap of the magnetic flux barrier. In this case, the non-magnetic body 71 may be provided in a manner adjacent to the bonded magnet 61.

[0047] The second magnet hole 322 is arranged radially inwardly of the first magnet hole 321. The two second magnet holes 322 are paired and formed into a roughly V-shape (a roughly V-shape that is opened radially outward). In addition, the circumferential extension range of a pair of second magnet holes 322 is larger than the circumferential extension range of a pair of first magnet holes 321. A bonded magnet 62 is set in each of the second magnet holes 322. In addition, in the second magnet hole 322, a gap (hole) is formed at both ends of the bonded magnet 62 in the long side direction. The gap functions as a magnetic flux barrier. A non-magnetic body 72 can be arranged in the gap of the magnetic flux barrier. The non-magnetic body 72 can be arranged in a manner adjacent to the bonded magnet 62. The structure of the non-magnetic body 72 itself can be the same as the above-mentioned non-magnetic body 71.

[0048] The rotor core 32 has the first magnet hole 321 and the second magnet hole 322 to have three portions 3211 , 3212 , and 3213 (hereinafter also referred to as a first portion 3211 , a second portion 3212 , and a third portion 3213 ) connected in the radial direction only via bridge portions.

[0049] Specifically, the first portion 3211 extends radially outward from the first magnet hole 321. The first portion 3211 forms a portion of the outer peripheral surface 328 of the rotor core 32.

[0050] The second portion 3212 extends to the outer peripheral surface 328 of the rotor core 32 through the circumferential sides between the second magnet hole 322 and the first magnet hole 321. The second portion 3212 forms a part of the outer peripheral surface 328 of the rotor core 32 on both circumferential sides of the first portion 3211. The second portion 3212 forms a magnetic path of the q-axis magnetic flux. Specifically, the q-axis magnetic flux flows from one end of the second portion 3212 toward the other end through the second magnet hole 322 and the first magnet hole 321.

[0051] The third portion 3213 passes radially inward from the second magnet hole 322 and extends to both circumferential sides to the outer peripheral surface 328 of the rotor core 32. The third portion 3213 forms a part of the outer peripheral surface 328 of the rotor core 32 on both circumferential sides of the second portion 3212.

[0052] Furthermore, the rotor core 32 has the three portions 3211 , 3212 , and 3213 , and thus has the plurality of bridge portions 41 , 42 , 43 , and 44 connecting the three portions 3211 , 3212 , and 3213 .

[0053] The bridge portion 41 (hereinafter also referred to as "first bridge portion 41") supports the first portion 3211 radially outwardly relative to the second portion 3212. A pair of first bridge portions 41 are provided on both circumferential sides (circumferentially outwardly) of the first portion 3211. The first bridge portion 41 extends between the outer peripheral surface 328 of the rotor core 32 and the first magnet hole 321.

[0054] The bridge portion 42 (hereinafter also referred to as "second bridge portion 42") supports the second portion 3212 radially outwardly relative to the third portion 3213. A pair of second bridge portions 42 are provided on both circumferential sides (circumferentially outwardly) of the second portion 3212. The second bridge portion 42 extends between the outer peripheral surface 328 of the rotor core 32 and the second magnet hole 322.

[0055] The bridge portion 43 supports the first portion 3211 with respect to the second portion 3212 on the d-axis.

[0056] The bridge portion 44 supports the second portion 3212 on the d-axis with respect to the third portion 3213 .

[0057] The structure of the rotor core 32 related to the bonded magnets 61 and 62 is arbitrary and is not limited to Figure 2 as well as Figure 3 For example, in Figure 2 as well as Figure 3 In the example shown, bonded magnets 61 and 62 are provided, but one of bonded magnets 61 and 62 may be omitted. Alternatively, the other bonded magnet may be arranged radially inward of bonded magnet 62 so that third portion 3213 becomes a magnetic path of q-axis magnetic flux.

[0058] Next, refer to Figure 4 The following figures describe the manufacturing device 100 in detail together with the manufacturing method of the rotor core 32 described above. In the following description, the equipment refers to the equipment in which the manufacturing device 100 is set, usually the equipment of a factory, etc. In addition, in the following description, although the fixed-type components among the various structural components of the manufacturing device 100 are components that are fixed in a manner that cannot be moved relative to the equipment during the operation of the present manufacturing method, the components can also be movable during the installation, etc. In addition, the fixed-type components do not need to be fixed as a whole, and a part of them can also be movable relative to other fixed parts. On the other hand, the movable-type components among the various structural components of the manufacturing device 100 are components that are moved as a whole relative to the equipment during the operation of the present manufacturing method. In addition, the equipment does not necessarily need to be fixed to the ground, and can also be a structure that is movable relative to the ground.

[0059] In the following description, as described above, the axial direction refers to the direction in which the central axis of the rotor core 32 (workpiece W) corresponding to the rotating shaft 12 of the motor 1 extends, and the radial direction refers to the radial direction centered on the central axis of the rotor core 32. In addition, the circumferential direction corresponds to the rotation direction around the central axis of the rotor core 32.

[0060] Figure 4 1 is a flowchart schematically showing the flow of the method for manufacturing the rotor 30 according to the present embodiment. Figures 5 to 11 yes Figure 4 Detailed description of a specific step in the manufacturing method shown. Figure 5 This is a diagram illustrating the clamping process. Figure 6 This is a diagram illustrating the heating process. Figure 7 as well as Figure 8 This is an illustration of the placement process. Fig. 9 This is an explanatory diagram of the injection molding process in the case of only unipolar orientation. Fig.10 It is an explanatory diagram of the injection molding process in the case of omnipolar orientation. Fig.11 This is a diagram for explaining the removal process.

[0061] First, the manufacturing method includes a preparation step (step S500) of preparing a workpiece W for the rotor core 32. In addition, as described above, the rotor core 32 has magnet holes 321 and 322. In addition, the preparation step may also include a step of arranging the non-magnetic bodies 71 and 72 in the magnet holes 321 and 322. In this case, the workpiece W includes the rotor core 32 and the non-magnetic bodies 71 and 72.

[0062] Next, the manufacturing method includes a clamping step (an example of a holding step) of clamping the rotor core 32 (workpiece W) to the die fixture 130 (step S502). Figure 5 1 and 2 schematically show the rotor core 32 clamped by the mold clamp 130 in a cross-sectional view (a cross-sectional view of a section passing through the rotating shaft 12 , the same applies hereinafter).

[0063] In this embodiment, the mold clamp 130 includes an upper clamp 131 and a lower clamp 132, and the rotor core 32 is clamped between the upper clamp 131 and the lower clamp 132. The upper clamp 131 and the lower clamp 132 can be fastened in the axial direction. In this case, the upper clamp 131 and the lower clamp 132 can apply axial pressure (along the direction of the rotating shaft 12) to the rotor core 32. The upper clamp 131 can function as an injection mold and can have a bonded magnet material 90 from the injection molding device 108 (refer to Fig. 9 The mold fixture 130 may include a sprue or the like connected to a nozzle (not shown) of an injection molding machine.

[0064] The mold fixture 130 is movable (i.e., can be moved relative to the device) and can move between a placement position placed on the alignment magnetic field applying device 120 described later and a non-placement position away from the alignment magnetic field applying device 120. In addition, the movement of the mold fixture 130 can be achieved by a robot or the like, or by a conveyor or the like.

[0065] Next, the manufacturing method includes a heating step (step S504) of heating the rotor core 32 (workpiece W) while the rotor core 32 is placed in the mold fixture 130. Figure 6 , the rotor core 32 heated in the heating furnace 140 is schematically shown in a cross-sectional view. In addition, the heating process can also be achieved by any heating device other than the heating furnace 140 (for example, an induction heating device). In addition, a heating device such as an induction heating device can also be built into the mold fixture 130 itself. In this case, during the injection molding process described later, the mold fixture 130 can be heated to a suitable temperature together with the rotor core 32.

[0066] Next, the manufacturing method includes a placement process (step S506) of forming a state in which the orientation magnetic field applying device 120 abuts against the radial outer side of the workpiece W (hereinafter also referred to as the "placement state"). That is, the manufacturing method includes a placement process of moving the workpiece W from a non-placement position to a placement position. The orientation magnetic field applying device 120 can apply an orientation magnetic field to the workpiece W in the placement state. The orientation magnetic field acts on the bonded magnet material 90 ejected in the injection molding process described later. That is, the orientation magnetic field has the effect of orienting the magnetic components in the bonded magnet material 90 and functioning as a magnet (bonded magnet 61, 62). In addition, in the placement state, although the orientation magnetic field applying device 120 abuts against the radial outer side of the workpiece W, it can also be opposed (radially opposed) with a slight gap.

[0067] exist Figure 7 as well as Figure 8 In FIG. 1 , as an explanatory diagram of the placement process, the process of the workpiece W being transferred to the placement state is schematically shown in a cross-sectional view. Figure 7 as well as Figure 8 In the example shown, the workpiece W is moved to the placement state by descending together with the mold fixture 130 (see arrow R70). That is, the workpiece W is positioned relative to the orientation magnetic field applying device 120 by descending together with the mold fixture 130 (see arrow R70) while being clamped by the mold fixture 130. In addition, the descending action of the workpiece W can also be achieved by a robot or the like.

[0068] The orientation magnetic field applying device 120 may be a fixed type, such as Figure 7 as well as Figure 8As shown, it can be set (fixed) on the device 200. The orientation magnetic field applying device 120 abuts against the workpiece W over the entire axial length. The orientation magnetic field applying device 120 can have an axial length significantly longer than the entire axial length of the workpiece W. In addition, the orientation magnetic field applying device 120 can have non-magnetic parts 122 at both ends (upper and lower parts) in the axial direction.

[0069] The orientation magnetic field applying device 120 may be any structure as long as it can generate an orientation magnetic field, for example, it may be in the form of an orientation magnetic yoke with a relatively large heat capacity. Although the orientation magnetic field applying device 120 may have a permanent magnet for generating an orientation magnetic field built in, it is preferred to have an electromagnet (not shown) built in so as to be able to turn on / off the generation state of the orientation magnetic field. In this case, as described later, when the mold fixture 130 is moved from the placement position to the non-placement position, the force required for the movement can be relatively small by turning off the electromagnet, which can simplify the equipment.

[0070] Next, the manufacturing method includes an injection molding process (step S508) of filling the magnet holes 321 and 322 with the bonded magnet material 90 by the injection molding device 108. The injection molding process is performed in a state where an orientation magnetic field is applied to the workpiece W in the above-mentioned placed state by the orientation magnetic field applying device 120. The state where the orientation magnetic field is applied can be maintained until the subsequent removal process (step S510).

[0071] The orientation by such an orientation magnetic field applying device 120 can be performed only for a single pole or for all poles. Hereinafter, the case of performing only a single pole orientation is also referred to as "the case of single pole orientation", and the case of performing all pole orientation is also referred to as "the case of all pole orientation".

[0072] exist Fig. 9 The two figures schematically show the state of the injection molding process in the case of only monopolar orientation, the upper side is a top view, and the lower side is a side view (cross-sectional view). Fig. 9 As shown, the orientation magnetic field applying device 120 abuts against the semicircular portion of the workpiece W in the radial direction. Fig. 9 As shown, the bolts BT for fastening the mold clamp 130 (i.e., the bolts BT for applying axial pressing force between the upper clamp 131 and the lower clamp 132) can be set over a relatively large range without the orientation magnetic field applying device 120. As a result, even when the injection pressure is increased, the possibility of the bonded magnet material 90 leaking out from the interlayers of the workpiece W (between the steel plates) during injection molding can be effectively reduced. As a result, it is also possible to improve the magnetic properties of the motor 1 by using a bonded magnet material (for example, a bonded magnet material with a high magnetic powder content) that has relatively low fluidity (and therefore needs to be injected at a relatively high injection pressure).

[0073] exist Fig.10 The two figures schematically show the injection molding process in the case of omnipolar orientation, the upper side is a top view, and the lower side is a side view (cross-sectional view). Fig.10 As shown, the orientation magnetic field applying device 120 may be in contact with the entire circumference of the workpiece W in the radial direction. Fig.10 As shown in FIG. 1 , the bolt BT for fastening the mold fixture 130 may also be set near the rotating shaft 12. In this case, the bolt fastening portion may also have a tapered surface 1114 so that the pressing force of the bolt BT is also transmitted to the outer peripheral side of the workpiece W (that is, an axial force is also generated on the outer peripheral side of the workpiece W). Fig. 9 The structure shown is the same and can effectively reduce the possibility of the bonded magnet material 90 leaking out from between the layers of the workpiece W (between the steel plates) during injection molding even when the injection pressure is increased.

[0074] Next, the present manufacturing method includes a taking-out step (step S510) of moving the workpiece W after the filling of the bonded magnet material 90 is completed to a position away from the orientation magnetic field applying device 120. That is, the present manufacturing method includes a taking-out step (step S510) of moving the workpiece W from the placement position to the non-placement position. The start of the taking-out step (step S510) may also be performed at a stage where the fluidity of the filled bonded magnet material 90 actually disappears (that is, a stage where the orientation is maintained even if the application of the orientation magnetic field by the orientation magnetic field applying device 120 disappears). In addition, the non-placement position may be the same as or different from the non-placement position of the moving source of the above-mentioned placement step. Fig.11 The state of the workpiece W being taken out in the middle is schematically shown in a cross-sectional view. In this case, the workpiece W can also be lifted up by being ejected upward by the ejector pin 202 or a similar component (e.g., a workpiece ejector) on the equipment side (see arrow R110). Alternatively, the workpiece W can also be lifted up by being held by a robot (not shown). In this way, the method of taking out the workpiece W is arbitrary.

[0075] Next, the present manufacturing method includes a step (step S512) of completing the solidification of the bonded magnet material 90 by heating the removed workpiece W. This step may be omitted as appropriate.

[0076] Thus, according to the manufacturing method and the manufacturing apparatus 100, the workpiece W is heated together with the mold fixture 130 by the heating process before the injection molding process, so that in the injection molding process, the heated workpiece W can be filled with the bonded magnet material 90 via the heated mold fixture 130. Thus, the bonded magnet material 90 can be filled in a desired flow manner. In addition, the temperature (temperature after heating) reached by the workpiece W and the mold fixture 130 through the heating process can be determined according to the target temperature to be achieved in the injection molding process.

[0077] In particular, according to the present manufacturing method and manufacturing apparatus 100, the heating process of the workpiece W is performed in a state where the workpiece W is away from the orientation magnetic field applying device 120 (for example, in a state where the workpiece W is placed in the heating furnace 140). As a result, it is possible to prevent the inconvenience caused when the heating process is performed on the workpiece W in a state where the workpiece W is placed in the orientation magnetic field applying device 120. That is, when the heating process is performed on the workpiece W in a state where the workpiece W is placed in the orientation magnetic field applying device 120, as described in the above-mentioned column of "Problems to be Solved by the Invention", not only the thermal efficiency is reduced, but also there is a possibility that a relatively high magnetic field for magnetic field orientation cannot be generated due to the high temperature of the orientation magnetic field applying device 120. In contrast, according to the present manufacturing method and manufacturing apparatus 100, as described above, the thermal efficiency is good, and a relatively high magnetic field for magnetic field orientation can be stably generated from the orientation magnetic field applying device 120.

[0078] In addition, in reference Figures 5 to 11 In the above-mentioned manufacturing method and manufacturing device 100, although the mold fixture 130 moves between the non-placement position and the placement position together with the workpiece W relative to the fixed orientation magnetic field applying device 120, it is also possible to move the mold fixture 130 and the workpiece W together with the workpiece W between the non-placement position and the placement position, for example, as follows Figure 12 to Figure 14 As in the illustrated modification, a part of the alignment magnetic field applying device is movable.

[0079] In addition, in reference Figures 5 to 11 In the above-mentioned manufacturing method, when the heating device used in the heating process (step S504) is a heating device built into the mold fixture 130, the heating of the heating device can also be performed in the injection molding process (step S508). In this case, the heating of the heating device can be performed in order to maintain the mold fixture 130 (and the workpiece W) at a desired temperature. The heating in this case is for the purpose of maintaining or slightly increasing the temperature of the mold fixture 130 that has been heated in the heating process (step S504), so compared with the case where there is no heating process (step S504), less energy is sufficient. Therefore, the loss caused by the transfer of heat to the orientation magnetic field application device 120 is less, and the effect of the above-mentioned embodiment can still be obtained.

[0080] Figure 12 to Figure 14 1 is an explanatory diagram of an alignment magnetic field applying device 120A of a manufacturing device 100A according to a modified example, and schematically shows the state of a specific step of the present manufacturing method in a top view. Specifically, Fig.12 This is a diagram to illustrate the placement process. Fig.13 This is an illustration of the injection molding process (placement state). Fig.14 This is a diagram for explaining the removal process.

[0081] exist Figure 12 to Figure 14 In the modified example shown, the orientation magnetic field applying device 120A includes a first orientation magnetic yoke 121A and a second orientation magnetic yoke 122A. The first orientation magnetic yoke 121A and the second orientation magnetic yoke 122A are cylindrical in shape as a whole. The second orientation magnetic yoke 122A can move radially relative to the first orientation magnetic yoke 121A. Specifically, the second orientation magnetic yoke 122A can move between a non-placement position radially away from the first orientation magnetic yoke 121A and a placement position radially abutting or approaching the first orientation magnetic yoke 121A. The placement state of the workpiece W relative to the orientation magnetic field applying device 120A (the state in which the second orientation magnetic yoke 122A is in the placement position) is the same as that of the orientation magnetic field applying device 120 of the above-mentioned embodiment, and the first orientation magnetic yoke 121A and the second orientation magnetic yoke 122A abut against the workpiece W over the entire axial length and over the entire circumference.

[0082] This modification example can also be applied and referred to Figure 4 However, in the case of this modified example, the second orientation yoke 122A waits in the non-placed position before the placement step (step S506) after the heating step (step S504) of heating the rotor core 32 (workpiece W). In addition, the heating step (step S504) of heating the rotor core 32 (workpiece W) is similar to the above-mentioned manufacturing method. Figure 4 The above-mentioned manufacturing method is the same and is performed in a state where the rotor core 32 and the orientation magnetic field applying device 120A are thermally separated. In this modified example, in the placing step (step S506), Fig.12As schematically shown, the rotor core 32 (workpiece W) is positioned relative to the first orientation yoke 121A (see arrow R122), and the second orientation yoke 122A is positioned relative to the first orientation yoke 121A (see arrow R121). That is, the second orientation yoke 122A is moved from the non-placement position to the placement position. In addition, in this modification, although the second orientation yoke 122A is capable of moving in the radial direction, it may also be capable of moving in the axial direction in addition to or instead of this. In this case, the non-placement position of the second orientation yoke 122A can be set to a position where there is no possibility of interfering with the movement of the rotor core 32 when positioning the rotor core 32 (workpiece W) relative to the first orientation yoke 121A. The placement state, as compared to the reference Figure 4 The above-mentioned manufacturing method is the same as Fig.13 As shown in FIG. 1 , the first orientation yoke 121A and the second orientation yoke 122A surround the rotor core 32 as a whole. When the injection molding process is completed, the removal process (step S510) is performed. In the removal process (step S510), as shown in FIG. Fig.14 As schematically shown, the second orientation yoke 122A moves to the non-placed position away from the first orientation yoke 121A (see arrow R141 ), and the rotor core 32 (workpiece W) moves to a position away from the first orientation yoke 121A (see arrow R142 ).

[0083] According to this modification, it is possible to obtain a reference Figure 4 The same effects as those of the above-mentioned manufacturing method and manufacturing apparatus 100. In addition, according to this modified example, by moving the second orientation yoke 122A from the non-placement position to the placement position immediately before the injection molding process, the heat that may be generated before the injection molding process is performed can be suppressed to a minimum from the movement of the rotor core 32 (workpiece W) to the second orientation yoke 122A.

[0084] Next, refer to Fig.15 The following figures illustrate a manufacturing method and a manufacturing apparatus 100B of an embodiment (hereinafter, also referred to as “embodiment 2” for distinction) that is different from the above-described embodiment (hereinafter, also referred to as “embodiment 1” for distinction).

[0085] Fig.15 1 is a flowchart schematically showing the flow of the method for manufacturing the rotor 30 of the present embodiment (Example 2). Figures 16 to 20 yes Fig.15 Detailed description of a specific step in the manufacturing method shown. Fig.16 This is a diagram illustrating the heating process. Fig.17 This is a diagram to illustrate the configuration process. Fig.18 This is a diagram to explain the mold closing process and placement process. Fig.19 This is an illustration of the injection molding process. Fig. 20This is a diagram for explaining the mold opening process and the retreat process.

[0086] The manufacturing apparatus 100B of this embodiment is different from the manufacturing apparatus 100 of the above-mentioned embodiment 1 in that the mold fixture 130 is replaced by the mold 160, and the orientation magnetic field applying apparatus 120 is replaced by the orientation magnetic field applying apparatus 120B. In addition, the manufacturing apparatus 100B of this embodiment is different from the manufacturing apparatus 100 of the above-mentioned embodiment 1 in that a heating apparatus 140B is added. In this embodiment, there are cases where the same reference numerals are attached to the structural members that are substantially the same as those of the above-mentioned embodiment 1, and the description thereof is omitted.

[0087] The following, with Fig.15 The manufacturing apparatus 100B will be described together with the description of the present manufacturing method shown.

[0088] First, the manufacturing method includes a preparation step (step S1500) of preparing a workpiece W of the rotor core 32. The preparation step (step S1500) may be the same as the preparation step (step S500) of the first embodiment.

[0089] Next, the manufacturing method includes a heating step of heating the mold 160 (step S1502). Fig.16 As shown schematically, the mold 160 may have a built-in heater 142 of the heating device 140B. The heater 142 may be built-in each of the upper mold 161 on the movable side and the lower mold 162 on the fixed side. In addition, the heater 142 may be in the form of an induction heating device.

[0090] In this embodiment, the orientation magnetic field applying device 120B is movable and can move between a non-placement position and a placement position that are thermally separated from the mold 160. The orientation magnetic field applying device 120B is maintained in the non-placement position during the heating process (step S1502). As a result, the heat from the heating device 140B during the heating process (step S1502) will not be transferred to the orientation magnetic field applying device 120B via the mold 160, and the thermal efficiency of the heating process (step S1502) can be improved.

[0091] Next, the manufacturing method includes a heating step (step S1504) of heating the rotor core 32 (workpiece W). The heating step (step S1504) is similar to the heating step (step S1504). Figure 6The heating process (step S504) of the above-mentioned embodiment 1 is the same and can be performed using the heating furnace 140. In addition, the heating process can also be implemented by any heating device other than the heating furnace 140 (for example, an induction heating device). In the case of using any heating device other than the heating furnace 140, the heating process (step S1504) can be performed at a position where heat is not actually transferred to the orientation magnetic field application device 120B. As a result, in the heating process (step S1504), the heat from the heating device is not actually transferred to the orientation magnetic field application device 120B, and the thermal efficiency of the heating process (step S1504) can be improved.

[0092] In addition, the heating step (step S1504) may be performed in parallel with the temperature increasing step (step S1502).

[0093] Next, the manufacturing method includes a configuration step of positioning (putting) the heated workpiece W into the mold 160 in the mold opening state (step S1506). Fig.17 1 shows the workpiece W in a state of being positioned relative to the mold 160. At this time, the orientation magnetic field applying device 120B is still maintained in the non-placed position. As a result, the space around the mold 160 is opened, and the workability when positioning the workpiece W relative to the mold 160 is improved. In addition, the movement of heat that may be generated before the injection molding process is performed from the rotor core 32 (workpiece W) to the orientation magnetic field applying device 120B can be suppressed to a minimum.

[0094] Next, the manufacturing method comprises: Fig.18 As shown by arrows R181 and R182, the mold 160 is moved from the open mold state to the closed mold state in the mold closing process (step S1508A), and the orientation magnetic field application device 120B is moved from the non-placement position to the placement position in the placement process (step S1508B). If the placement process is executed, the same as the reference Figure 7 as well as Figure 8The placement process (step S506) of the above-mentioned embodiment 1 is the same, and the state (placement state) in which the orientation magnetic field applying device 120B abuts against the radial outer side of the workpiece W is formed. In addition, the mold clamping process (step S1508A) and the placement process (step S1508B) are preferably performed in parallel from the perspective of efficiency, but they can also be performed separately with a time difference. For example, when the time required for the mold clamping process (step S1508A) is longer than the time required for the placement process (step S1508B), the start time of the placement process (step S1508B) can be delayed in such a way that the mold clamping process (step S1508A) and the placement process (step S1508B) are ended at the same time. In this case, just before the next injection molding process (step S1510), the orientation magnetic field applying device 120B can be moved from the non-placement position to the placement position, and the heat that may be generated before the injection molding process is performed can be suppressed to a minimum from the movement of the rotor core 32 (workpiece W) to the orientation magnetic field applying device 120B.

[0095] Then, if Fig.19 As shown schematically, the manufacturing method includes an injection molding process (step S1510) of filling the magnet holes 321 and 322 with the bonded magnet material 90 by the injection molding device 108. The injection molding process is performed in a state where an orientation magnetic field is applied to the workpiece W in the above-mentioned placed state by the orientation magnetic field applying device 120. The state where the orientation magnetic field is applied can be maintained until the subsequent retreat process (step S1512B).

[0096] In this embodiment, the upper mold 161 of the mold 160 functions as an injection mold and has a bonding magnet material 90 from the injection molding device 108 (refer to Fig. 9 etc.) through path 400.

[0097] Next, the manufacturing method comprises: Fig. 20 As shown by arrows R201 and R202, the mold opening process (step S1512A) of migrating the mold 160 from the mold closing state to the mold opening state, and the retreat process (step S1512B) of moving the orientation magnetic field applying device 120B from the placement position to the non-placement position. In addition, the mold opening process (step S1512A) and the retreat process (step S1512B) are preferably performed in parallel from the perspective of efficiency, but can also be performed separately with a time difference.

[0098] Next, the manufacturing method includes a removal step (step S1514) of removing the workpiece W from the mold 160 at a stage where the bonded magnet material 90 is solidified to a certain extent. The stage where the bonded magnet material 90 is solidified to a certain extent may correspond to a stage where the fluidity of the filled bonded magnet material 90 is substantially lost (i.e., a stage where the orientation is maintained even if the orientation magnetic field applied by the orientation magnetic field applying device 120 is lost). This removal step may be implemented by a robot or the like.

[0099] Next, the present manufacturing method includes a step (step S1516) of completing the solidification of the bonded magnet material 90 by heating the removed workpiece W. This step may be omitted as appropriate.

[0100] According to this embodiment, the same effects as those of the above-mentioned embodiment can be obtained.

[0101] In particular, according to the present manufacturing method and manufacturing apparatus 100B, the temperature increase process (step S1502) for the mold 160 and the heating process (step S1504) for the workpiece W are performed when the orientation magnetic field applying device 120B is in a non-placed position. As a result, it is possible to prevent the inconvenience caused by the same temperature increase process and heating process when the orientation magnetic field applying device 120B is in a placed position. That is, when the same temperature increase process and heating process are performed when the orientation magnetic field applying device 120B is in a placed position, as described in the above-mentioned "Problems to be Solved by the Invention" column, there is a possibility that not only the thermal efficiency is reduced, but also a relatively high magnetic field for magnetic field orientation cannot be generated due to the high temperature of the orientation magnetic field applying device 120B. In contrast, according to the present manufacturing method and manufacturing apparatus 100B, as described above, the thermal efficiency is good, and a relatively high magnetic field for magnetic field orientation can be stably generated from the orientation magnetic field applying device 120B.

[0102] In addition, in the present manufacturing method and manufacturing device 100B, the heating process (step S1504) is performed separately from the above-mentioned temperature increase process (step S1502), but it can also be realized by the heating device 140B instead of or in addition to it. In this case, the heating process (step S1504) and the temperature increase process (step S1502) can also be performed by the heating device 140B after the arrangement process (step S1506) and before the placement process (step S1508B).

[0103] Next, refer to Fig.21 The following drawings illustrate a manufacturing method and a manufacturing apparatus 100C according to yet another embodiment (hereinafter, also referred to as “Embodiment 3” for distinction).

[0104] Figure 21 to Figure 231 is an explanatory diagram of a manufacturing method and a manufacturing apparatus 100C according to Embodiment 3. Fig.21 Indicates the state after injection molding. Fig. 22 represents the state in which the mold 160C is opened (i.e., the state in which the upper mold 161C and the lower mold 162C are separated), Fig.23 The diagram shows a state in which the orientation magnetic field applying device 120C is moved upward in the axial direction.

[0105] The manufacturing method and manufacturing device 100C of the third embodiment are mainly different from the second embodiment in that the orientation magnetic field applying device 120C is movable in the axial direction. In this case, the ejector pin 202 of the device 200 can also be used to drive the orientation magnetic field applying device 120C in the axial direction. Fig. 22 ), the orientation magnetic field applying device 120C moves to an axially upper position that does not overlap with the workpiece W when viewed in the radial direction. Fig.23 As shown, in order to remove the workpiece W, the robot 290 or the like pushes out the workpiece W in the radial direction (see arrow R230 ), thereby being able to move (discharge) the workpiece W in the radial direction (see arrow R231 ).

[0106] In the third embodiment, the workpiece W may be heated in the heating furnace 140 or the like in the first embodiment, and then formed into Fig.21 Alternatively, the orientation magnetic field applying device 120C may be in a state of retreating upward ( Fig.23 ) is performed, and the workpiece W is heated by a heating device (not shown) in the mold 160C. In this case, after the workpiece W is heated, the orientation magnetic field applying device 120C may be moved axially downward to form Fig.21 In this case, by moving the orientation magnetic field applying device 120C from the non-placement position to the placement position immediately before the injection molding process (step S1510), the heat that may be generated before the injection molding process is performed can be suppressed to a minimum from the movement of the rotor core 32 (workpiece W) to the orientation magnetic field applying device 120C.

[0107] According to such a third embodiment, the same effects as those of the above-mentioned embodiments can be obtained.

[0108] In addition, although the manufacturing method and manufacturing apparatus 100C of Example 3 use the mold 160C like the mold 160 described in Example 2, they can also be applied to the case of using the mold fixture 130 described in Example 1. That is, in the manufacturing apparatus 100A of the modified example, the orientation magnetic field applying apparatus 120C of Example 3 can also be used to replace the orientation magnetic field applying apparatus 120A.

[0109] Although each embodiment is described in detail above, it is not limited to a specific embodiment, and various modifications and changes can be made within the scope of the technical solution. In addition, all or multiple structural components of the above-mentioned embodiments can also be combined.

[0110] Description of Reference Numerals

[0111] 1…motor (rotating electric machine), 32…rotor core (rotor core for rotating electric machine), 321, 322…magnet holes, 61, 62…bonded magnets, 100…manufacturing device, 108…injection molding device, 120, 120A, 120B, 120C…orientation magnetic field applying device, 130…mold fixture, 160, 160C…mold, 140…heating furnace (heating device), 140B…heating device, W…workpiece.

Claims

1. A method for manufacturing a rotor for a rotating electrical machine, comprising the following steps: A heating step of heating the workpiece in a non-placed state where the orientation magnetic field applying device is away from the workpiece of the rotor core for a rotating electrical machine having a magnet hole; a placing step of forming a placing state in which the alignment magnetic field applying device is closer to the workpiece than the non-placement state after the heating step; and In the injection molding process, in the above-mentioned placement state, the orientation magnetic field from the above-mentioned orientation magnetic field applying device is applied to the above-mentioned workpiece, and the material for bonding the magnet is filled into the above-mentioned magnet hole of the above-mentioned workpiece.

2. The method for manufacturing a rotor for a rotating electrical machine according to claim 1, wherein: The heating step includes a step of heating the workpiece while being thermally separated from the alignment magnetic field applying device.

3. The method for manufacturing a rotor for a rotating electrical machine according to claim 1, wherein: The orientation magnetic field applying device is capable of moving between a placement position corresponding to the placement state and radially opposite to or in contact with the workpiece, and the non-placement position radially outward or axially offset from the placement position. The placement step includes a step of moving the alignment magnetic field application device from the non-placement position to the placement position.

4. The method for manufacturing a rotor for a rotating electrical machine according to any one of claims 1 to 3, wherein: It also includes the heating process of the mold used for heating injection molding. The placing step is performed after the heating step.

5. The method for manufacturing a rotor for a rotating electrical machine according to claim 1 or 2, wherein: The method further comprises a step of holding the workpiece with a mold fixture. The heating step includes a step of heating the workpiece held by the mold fixture together with the mold fixture, which is performed after the holding step. The placing step is performed after the holding step and includes positioning the workpiece held by the mold fixture relative to the alignment magnetic field applying device.

6. A rotor manufacturing device for a rotating electrical machine, comprising: A mold or a movable mold fixture on which a workpiece of a rotor core for a rotating electrical machine having a magnet hole is placed; A movable or fixed orientation magnetic field applying device; An injection molding device for filling the magnet hole of the workpiece with a material for bonding the magnet; and A heating device is thermally separated from the alignment magnetic field applying device and heats the workpiece.

7. The rotating electrical machine rotor manufacturing device according to claim 6, wherein: The alignment magnetic field applying device is of a movable type and can be moved in a radial direction or an axial direction of the workpiece relative to the mold or the movable mold fixture.

8. The rotating electrical machine rotor manufacturing device according to claim 6, wherein: The above-mentioned orientation magnetic field applying device is of fixed type. The mold fixture holds the workpiece that has been placed, and is movable between a placement position where an orientation magnetic field from the orientation magnetic field applying device can be applied to the workpiece, and a non-placement position away from the orientation magnetic field applying device. The heating device heats the mold fixture that holds the workpiece and is in the non-placed position together with the workpiece.

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