Rotor manufacturing method, rotor and IPM motor with rotor

Abstract

The invention provides a method for manufacturing a rotor in which a magnet is held in a rotor core. The method for manufacturing the rotor includes: a magnet insertion step of inserting the magnet into the magnet insertion hole of the rotor core; a rotor core holding step of covering at least a part of an end surface in a lamination direction of the rotor core into which the magnet is inserted from the lamination direction by using a plate having a pin insertion hole into which a staking pin can be inserted, and pressurizing the rotor core in the lamination direction by using the plate; and a caulking step of caulking the rotor core in the lamination direction by using a caulking pin inserted into the pin insertion hole, and holding the magnet in the magnet insertion hole. In the rotor core holding step, the rotor core is held in a state in which an avoidance portion into which the plastically deformed steel plate enters is provided between the plate and a swaging surface on which the swaging pin comes into contact, and in the swaging step, the swaging pin comes into contact with the swaging pin, and the swaging pin comes into contact with the swaging pin. The rotor core held by the plate is crimped in the lamination direction by the crimp pin.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a rotor, a rotor, and an IPM motor having the rotor. Background Art

[0002] In a rotor that holds a magnet in a receiving hole that passes through a rotor core in an axial direction, a structure is known in which a portion of the receiving hole is plastically deformed to hold the magnet. For example, the rotor described in Japanese Publication No. 2013-34363 has a recessed portion that is recessed in the axial direction from an end face of the rotor core in the axial direction. The recessed portion extends radially inward from the receiving hole that holds the magnet. That is, the recessed portion is located radially inward of the receiving hole of the rotor core. The rotor causes the open front end portion that opens to the magnet side to abut against the magnet through the plastic deformation of the recessed portion. Thus, the rotor holds the magnet in the receiving hole.

[0003] As a manufacturing method of the rotor, first, the magnet is inserted into the receiving hole of the rotor core from the axial direction, and then, the rotor core is swaged (riveted) from both sides of the axial direction of the rotor core using a swaging jig while the magnet is inserted.

[0004] In the rotor core, the radial center of the recess is pushed in along the axial direction by the caulking tool that is larger than the width of the recess. The circumferential side walls of the recess are plastically deformed radially outward by the caulking jig. As a result, the open front end is pushed out radially outward by the plastic deformation of the circumferential side walls and contacts the magnet. The magnet is held in the accommodation hole by contacting the open front end.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2013-34363 Summary of the invention

[0008] Problems to be solved by the invention

[0009] The corner formed by the inner surface of the receiving hole and the circumferential side wall contacts the magnet by caulking. The force pressing the magnet radially outward by point contact is concentrated on the surface portion of the magnet contacted by the corner. Therefore, when caulking, excessive stress may be generated by the portion of the magnet contacted by the corner. Therefore, the following structure is desired: when the magnet is fixed to the rotor core by riveting, excessive stress is not generated in the magnet.

[0010] An object of the present invention is to provide a method for manufacturing a rotor and a rotor, wherein magnets located in magnet insertion holes of a rotor core are retained in the rotor core by riveting the rotor core, wherein when the magnets are fixed to the rotor core by riveting, no excessive stress is generated in the magnets.

[0011] Solutions to Solve Problems

[0012] In a rotor manufacturing method according to one embodiment of the present invention, the rotor has a plurality of steel plates stacked in a thickness direction and a magnet insertion hole penetrating the plurality of steel plates in the stacking direction, and the magnets located in the magnet insertion holes are retained in the rotor core by riveting the rotor core.

[0013] The manufacturing method of the above-mentioned rotor is characterized in that it comprises: a magnet insertion process, inserting the above-mentioned magnet into the above-mentioned magnet insertion hole; a rotor core holding process, using a plate having a pin insertion hole into which a rivet pin for riveting the above-mentioned rotor core can be inserted, covering at least a part of the end surface in the stacking direction of the above-mentioned rotor core in which the above-mentioned magnet is inserted from the stacking direction, and using the above-mentioned plate to pressurize the end surface in the stacking direction of at least one side of the above-mentioned rotor core in the stacking direction; and a riveting process, using a rivet pin inserted into the above-mentioned pin insertion hole to rivet the above-mentioned rotor core in the stacking direction to hold the above-mentioned magnet in the above-mentioned magnet insertion hole.

[0014] In the rotor core holding step, the rotor core is held in a state where an escape portion is provided between the rivet surface contacted by the rivet pin and the plate, into which the plastically deformed steel plate enters. In the riveting step, the rotor core held by the plate is riveted in the stacking direction using the rivet pin.

[0015] In addition, a rotor according to one aspect of the present invention comprises: a rotor core having a plurality of steel plates stacked in a thickness direction and a magnet insertion hole penetrating the plurality of steel plates in the stacking direction; and a magnet inserted into the magnet insertion hole, the magnet being held in the magnet insertion hole of the rotor core. A portion of the rotor core that contacts the magnet by riveting protrudes in the stacking direction from a riveted surface of the rotor core.

[0016] Furthermore, an IPM motor according to one aspect of the present invention includes: the above-mentioned rotor; and a stator including a stator coil and a stator core.

[0017] Effects of the Invention

[0018] According to the rotor manufacturing method, the rotor, and the IPM motor having the rotor according to one embodiment of the present invention, it is possible to realize a structure in which an excessive stress is not generated in the magnet when the magnet is fixed to the rotor core by caulking. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a cross-sectional view showing a schematic structure of an IPM motor according to an embodiment.

[0020] Figure 2 It is a perspective view showing a schematic structure of a rotor according to the embodiment.

[0021] Figure 3 yes Figure 2 Sectional view along line III-III.

[0022] Figure 4 It is a process diagram showing an example of a method for manufacturing a rotor according to an embodiment.

[0023] Figure 5 It is a diagram showing an example of a magnet inserting process according to the embodiment.

[0024] Figure 6 It is a diagram showing an example of a rotor core holding process according to the embodiment.

[0025] Figure 7 It is a diagram showing an example of a caulking process according to the embodiment.

[0026] Figure 8 It is a perspective view showing a schematic structure of a rotor according to the second embodiment.

[0027] Fig. 9 yes Figure 8 Sectional view along line IX-IX.

[0028] Fig.10 This is a diagram showing an example of a magnet inserting step according to the second embodiment.

[0029] Fig.11 This is a diagram showing an example of a rotor core holding step according to the second embodiment.

[0030] Fig.12 This is a diagram showing an example of a caulking step according to the second embodiment. DETAILED DESCRIPTION

[0031] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same or equivalent parts in the drawings are marked with the same symbols, and their descriptions are not repeated. In addition, the sizes of the components in each figure do not faithfully express the actual sizes of the components and the size ratios of the components.

[0032] In the following description, the direction parallel to the central axis P of the rotor 2 is referred to as the axial direction, the direction perpendicular to the central axis P is referred to as the radial direction, and the direction along the arc centered on the central axis P is referred to as the circumferential direction. However, the definition of this direction is not intended to limit the orientation of the motor 1 when in use.

[0033] In the following description, the thickness direction refers to a direction perpendicular to the surface having the largest area among the surfaces of the plate-like member.

[0034] In the following description, stacking refers to a state in which at least a portion of a plurality of plate-like members are positioned so as to overlap each other when viewed in the thickness direction of the plate-like members, and the adjacent plate-like members are in close contact with each other.

[0035] In the following description, the direction in which the plurality of steel plates 23 are stacked in the thickness direction is referred to as the stacking direction. In the following description, the stacking direction is the same as the direction parallel to the central axis P of the rotor 2, that is, the axial direction. However, the definition of this direction is not intended to limit the orientation of the rotor 2 when in use.

[0036] In the following description, “the same” includes not only the case of being strictly the same but also includes a range that can be regarded as substantially the same.

[0037] In addition, in the following description, expressions such as "fixed", "connected", "joined", and "mounted" (hereinafter referred to as fixed, etc.) include not only cases where components are directly fixed to each other, but also cases where components are fixed via other components. That is, in the following description, expressions such as fixed, etc. include the meaning of direct and indirect fixing of components to each other.

[0038] (Implementation Method 1)

[0039] (Motor structure)

[0040] Figure 1 1 is a cross-sectional view showing a schematic structure of a motor 1 according to Embodiment 1. The motor 1 is an IPM (Interior Permanent Magnet) motor. Figure 1 As shown, the motor 1 includes a rotor 2, a stator 3, a housing 4, and a shaft 20. The rotor 2 rotates about a central axis P relative to the stator 3. In the present embodiment, the motor 1 is a so-called inner rotor type motor in which the rotor 2 is rotatable about the central axis P in the cylindrical stator 3.

[0041] The rotor 2 includes a rotor core 21 formed by laminating a plurality of steel plates 23 and a magnet 22. The rotor 2 is located radially inside the stator 3 and is rotatable relative to the stator 3. The shaft 20 is fixed to the rotor core 21 in a state where the shaft 20 passes through the through hole 21a in the axial direction. Thus, the rotor core 21 rotates together with the shaft 20. The detailed structure of the rotor 2 will be described later.

[0042] The stator 3 is accommodated in the housing 4. In the present embodiment, the stator 3 is cylindrical. The rotor 2 is located radially inside the stator 3. That is, the stator 3 is located at a position facing the rotor 2 in the radial direction. The rotor 2 is located radially inside the stator 3 so as to be rotatable about the central axis P.

[0043] The stator 3 includes a stator core 31 and a stator coil 32. The stator coil 32 is wound around the stator core 31. The stator 3 is a well-known stator, and a detailed description of the structure is omitted.

[0044] The housing 4 is cylindrical and extends along the central axis P. In the present embodiment, the housing 4 is cylindrical and has an internal space capable of accommodating the rotor 2 and the stator 3. The detailed structure of the housing 4 will be omitted.

[0045] (Rotor Structure)

[0046] Next, the detailed structure of the rotor 2 will be described. Figure 2 2 is a perspective view showing a schematic structure of the rotor 2 according to the first embodiment. Figure 2 As shown, the rotor 2 has a rotor core 21 and a plurality of magnets 22 .

[0047] The rotor core 21 is columnar and extends along the central axis P, and has a plurality of steel plates 23 and a plurality of magnet insertion holes 21b. The plurality of steel plates 23 are stacked in the thickness direction. The magnet insertion holes 21b extend in the axial direction. Each steel plate 23 is a disc-shaped electromagnetic steel plate formed into a predetermined shape. The following description takes the case where the rotor 2 has one rotor core 21 as an example. In addition, the rotor can also be formed by stacking a plurality of rotor core blocks having the same structure as the rotor core described in the present embodiment in the axial direction.

[0048] The rotor core 21 has a through hole 21a at the center when viewed from the stacking direction. The rotor core 21 has a plurality of magnet insertion holes 21b arranged at predetermined intervals in the circumferential direction. The plurality of magnet insertion holes 21b penetrate the rotor core 21 in the stacking direction. Magnets 22 are inserted into these magnet insertion holes 21b.

[0049] When the rotor core 21 is viewed from the stacking direction, the magnet insertion hole 21b has a shape that is long in one direction. In the present embodiment, when viewed from the axial direction, the inner surface of one of the pair of inner surfaces constituting the long side of the magnet insertion hole 21b is located radially inward of the rotor core 21. The inner surface of the other of the pair of inner surfaces is located radially outward of the rotor core 21. Hereinafter, the inner surface of the magnet insertion hole 21b located radially inward is referred to as the inner insertion hole inner surface 21c, and the inner surface located radially outward is referred to as the outer insertion hole inner surface 21d.

[0050] The magnet 22 is a rectangular parallelepiped having an end face shape that can be inserted into the magnet insertion hole 21b. The end face of the magnet 22 has a long side that is substantially the same length as the long side of the magnet insertion hole 21b viewed from the stacking direction. In addition, the length of the magnet 22 in a direction perpendicular to the end face is substantially the same as the length of the magnet insertion hole 21b in the stacking direction.

[0051] Each of the plurality of steel plates 23 has an opening 23 a that constitutes a portion of the magnet insertion hole 21 b .

[0052] The steel plates 23 located at the two ends of the stacking direction among the plurality of steel plates 23 have riveted surfaces 23b riveted in the stacking direction. The riveted surfaces 23b are located on the outer surfaces in the thickness direction of the steel plates 23 located at the two ends of the stacking direction of the rotor core 21. The riveted surfaces 23b are riveted in the stacking direction by riveting pins A described later (see Figure 7 ).

[0053] A portion of the rivet surface 23b is plastically deformed by the rivet. That is, the rivet surface 23b has two rivet marks 23c formed by the plastic deformation of the rivet pin A. The two rivet marks 23c are located radially inward of the magnet insertion hole 21b and near the magnet insertion hole 21b. That is, the steel plate 23 is plastically deformed toward the magnet insertion hole 21b by the rivet.

[0054] Figure 3 yes Figure 2 The III-III line cross-sectional view in FIG. Figure 3 As shown, in the rotor core 21, a portion of the inner surface 21c of the inner insertion hole is plastically deformed toward the inside of the magnet insertion hole 21b by riveting. That is, a portion of the inner peripheral surface of the opening 23a with low rigidity of at least one steel plate 23 riveted in the stacking direction by the rivet pin A, that is, the inner surface 21c of the inner insertion hole protrudes toward the magnet 22.

[0055] A portion of the inner surface 21c of the inner insertion hole protruding toward the magnet 22 contacts the magnet 22 in the magnet insertion hole 21b. The magnet 22 is pressed toward the outer surface 21d of the insertion hole by the portion of the inner surface 21c of the inner insertion hole that contacts. Thus, the magnet 22 is in a state of being clamped by a portion of the inner surface 21c of the inner insertion hole and the outer surface 21d of the insertion hole. Therefore, the magnet 22 is held in the magnet insertion hole 21b in a state where a portion of the inner surface 21c of the inner insertion hole that has been plastically deformed is pressed against the outer surface 21d of the insertion hole.

[0056] In addition, in the steel plate 23 that has been plastically deformed, at least a portion from the position where the rivet pin A contacts to the magnet insertion hole 21b protrudes in the stacking direction from the rivet surface 23b. In other words, at least a portion of the steel plate 23 that has been plastically deformed by rivet protrudes outward in the stacking direction from the position of the riveted steel plate 23 in the stacking direction of the rotor core 21.

[0057] In the above structure, in the rotor core 21, at least a portion of the steel plate 23 that has been plastically deformed from the position where the caulking pin A contacts to the magnet insertion hole 21b protrudes further than the caulking surface 23b toward the end portion in the stacking direction of the rotor core 21. That is, a portion of the steel plate 23 is plastically deformed in the stacking direction of the rotor core 21 by the force applied by the caulking pin A.

[0058] As a result, the force applied to the magnet 22 by the plastically deformed steel plate 23 is dispersed by the plastic deformation in the stacking direction. Therefore, the rotor core 21 does not generate excess stress on the magnet 22. Therefore, compared with the case where the force applied to the magnet 22 is not dispersed in the stacking direction, the rotor core 21 can rivet the magnet 22 with a stronger force. Thus, the force required to hold the magnet 22 can be increased within a range that does not generate excess stress. In addition, even if force is applied to the magnet 22 in the radial direction due to magnetization or the operation of the motor, the portion in contact with the magnet 22 is difficult to elastically deform. Therefore, the rotor core 21 can stably hold the magnet 22 in the magnet insertion hole 21b.

[0059] In the above-described configuration, the motor 1 includes the rotor 2 and the stator 3, and the stator 3 includes the stator coil 32 and the stator core 31. Thus, the motor 1 including the rotor 2 having the above-described effects can be realized.

[0060] (Method for manufacturing rotor)

[0061] Next, a method for manufacturing the rotor 2 using the rotor core 21 and the magnet 22 formed of a plurality of steel plates 23 stacked in the thickness direction will be described. Hereinafter, only riveting in one direction of stacking will be described.

[0062] Figure 41 is a process diagram showing an example of a method for manufacturing the rotor 2 according to the first embodiment. Figure 4 As shown, the manufacturing method of the rotor 2 of the first embodiment includes a magnet inserting step S1, a rotor core holding step S2, and a caulking step S3. The manufacturing method of the rotor 2 is performed in the order of the magnet inserting step S1, the rotor core holding step S2, and the caulking step S3.

[0063] Figure 5 1 is a diagram showing an example of the magnet insertion step S1 of the first embodiment. Figure 5 As shown, the magnet insertion step S1 is a step of inserting the magnet 22 into the magnet insertion hole 21b of the rotor core 21. In the magnet insertion step S1, the rotor core 21 is placed on one plate B of a pair of plates B. One end surface of the rotor core 21 in the stacking direction contacts the contact surface B2 which is one end surface of one plate B in the thickness direction.

[0064] Next, the magnets 22 are inserted into the respective magnet insertion holes 21b on the other end surface of the rotor core 21 placed on one plate B by an insertion device (not shown). The magnets 22 are inserted into the magnet insertion holes 21b to a position where one end in the longitudinal direction contacts one plate B. Thus, the magnets 22 are held in the magnet insertion holes 21b.

[0065] Figure 6 1 is a diagram showing an example of the rotor core holding step S2 of the first embodiment. Figure 6 As shown, the rotor core holding step S2 is a step of holding the rotor core 21 with the magnets 22 inserted into the magnet insertion holes 21 b by a pair of plates B in a state where the rotor core 21 is pressed in the stacking direction.

[0066] In the rotor core holding step S2, the contact surface B2 of the other plate B is brought into contact with the other end surface of the rotor core 21 placed on the one plate B in the stacking direction by a driving device not shown. Then, the rotor core 21 is pressed in the stacking direction by the pair of plates B. Thus, the rotor core 21 is held by the pair of plates B at both ends in the stacking direction in a pressed state. In addition, the portion of the other end surface of the rotor core 21 in the stacking direction, which includes at least the magnet insertion hole 21b, is covered by the other plate B.

[0067] The pair of plates B has two pin insertion holes B1 into which the rivet pins A can be inserted. The two pin insertion holes B1 penetrate in the thickness direction of the plate B. Thus, in the rotor core 21, the portion overlapping with each pin insertion hole B1 as viewed from the stacking direction is riveted by the rivet pins A. In this way, the pair of plates B determines the rivet position on the rotor core 21. In the present embodiment, the two pin insertion holes B1 are located radially inward of the magnet insertion hole 21b and near the magnet insertion hole 21b relative to the rotor core 21 as viewed from the stacking direction.

[0068] The pair of plates B has two recesses B3 that are recessed from their respective contact surfaces B2 in the thickness direction by the thickness of the steel plate 23. When the pair of plates B are in contact with the rotor core 21, the two recesses B3 are recessed toward the outside of the rotor core 21 in the stacking direction relative to the rotor core 21. In addition, when the pair of plates B are in contact with the rotor core 21, the two recesses B3 extend from each pin insertion hole B1 toward the magnet insertion hole 21b as viewed from the stacking direction. In the present embodiment, as viewed from the stacking direction, the recess B3 extends from the pin insertion hole B1 to a position overlapping with the magnet insertion hole 21b. A gap is formed between the plate B on one side and the plate B on the other side and the steel plate 23 by the recess B3. That is, the recess B3 is configured as an escape portion into which the steel plate 23 enters after being plastically deformed in the stacking direction by the riveting step S3 described later.

[0069] Figure 7 1 is a diagram showing an example of the riveting step S3 of the first embodiment. Figure 7 As shown, the caulking step S3 is a step of caulking both ends of the rotor core 21 in the lamination direction by using the caulking pins A to hold the magnets 22 in the magnet insertion holes 21 b. Hereinafter, only the caulking in the other lamination direction will be described.

[0070] In the caulking step S3, the rotor core 21 is further pressurized in the lamination direction by the pair of plates B. While the rotor core 21 is pressurized, a caulking pin A is inserted into the pin insertion hole B1 of the other plate B by a driving device (not shown). The caulking pin A contacts the caulking surface 23b of the steel plate 23 in contact with the other plate B.

[0071] The rivet pin A is pressed against the steel plate 23 radially inward of the magnet insertion hole 21b and near the magnet insertion hole 21b in the stacking direction by a driving device (not shown). As a result, at least one of the plurality of steel plates 23 uses the outer surface of the steel plate 23 in contact with the other plate B as the rivet surface 23b, and the rivet pin A rivets the vicinity of the magnet insertion hole 21b.

[0072] A portion of the inner insertion hole inner surface 21c of the rotor core 21 is plastically deformed toward the inside of the magnet insertion hole 21b due to riveting. That is, the inner peripheral surface of the opening 23a with low rigidity of the steel plate 23 riveted in the stacking direction by the riveting pin A, i.e., the inner insertion hole inner surface 21c, is plastically deformed toward the magnet 22.

[0073] A portion of the inner surface 21c of the inner insertion hole that is plastically deformed toward the inner side of the magnet insertion hole 21b by riveting contacts the magnet 22. Furthermore, a portion of the inner surface 21c of the inner insertion hole abuts the magnet 22 against the outer surface 21d of the outer insertion hole. Thus, the magnet 22 is held in the magnet insertion hole 21b by the friction force generated between a portion of the inner surface 21c of the inner insertion hole that is plastically deformed by riveting and the outer surface 21d of the outer insertion hole.

[0074] In addition, at least a portion of the portion of the riveted steel plate 23 that overlaps with the recessed portion B3 when viewed in the stacking direction is plastically deformed outward in the stacking direction. That is, when viewed in the stacking direction, at least a portion of the portion of the steel plate 23 riveted in the stacking direction by the rivet pin A that overlaps with the recessed portion B3 of the plate B that is not in contact with the other side is plastically deformed outward in the stacking direction. The portion that is plastically deformed outward in the stacking direction enters the recessed portion B3.

[0075] In the manufacturing method configured as described above, in the rotor core holding step S2, the stacking direction end surface of the rotor core 21 stacked with a plurality of steel plates 23 is pressed in the stacking direction by a pair of plates B. At this time, a clearance portion, into which a part of the plastically deformed steel plate 23 enters, is formed between the steel plate 23 and the other plate B by the recessed portion B3 of the other plate B when viewed from the stacking direction.

[0076] In the rotor core holding process S2, the steel plate 23 of the rotor core 21 is plastically deformed toward the magnet insertion hole 21b by riveting while the other plate B is in contact with the steel plate 23. The inner surface 21c of the inner insertion hole is in contact with the magnet 22, and the magnet 22 is pressed against the inner surface 21d of the outer insertion hole. The portion of the steel plate 23 that overlaps with the recess B3 when viewed in the stacking direction is not pressurized by the other plate B, so it can be plastically deformed toward the outside of the stacking direction. Therefore, when the inner surface 21c of the inner insertion hole is in contact with the magnet 22 and is difficult to be plastically deformed toward the magnet 22, at least a portion of the portion of the steel plate 23 that overlaps with the recess B3 when viewed in the stacking direction is plastically deformed toward the recess B3. That is, the force applied to the steel plate 23 by riveting is dispersed into a force that causes the steel plate 23 to be plastically deformed toward the magnet 22 and a force that causes the steel plate 23 to be plastically deformed toward the recess B3. Therefore, in the caulking step S3, by plastically deforming a part of the steel plate 23 toward the recessed portion B3, when the magnet 22 is fixed to the rotor core 21 by caulking, an excessive stress is not generated in the portion of the magnet 22 that contacts the steel plate 23. Therefore, compared with the case where the force applied to the magnet 22 is not dispersed in the stacking direction, the rotor core 21 can be caulked with a stronger force to the magnet 22. As a result, the force required to hold the magnet 22 can be increased within a range where an excessive stress is not generated.

[0077] In addition, in the rotor core holding step S2, the recessed portion B3 of the other plate B is arranged as a relief portion in the stacking direction of the rotor core 21. In addition, in the riveting step S3, a portion of the riveted steel plate 23 is plastically deformed toward the relief portion, i.e., the recessed portion B3, located between the riveting surface 23b and the other plate B. Therefore, the rotor core 21 does not need to have a relief portion around the magnet insertion hole 21b. Therefore, for example, even if a radial external force is applied to the magnet 22, the portion that is plastically deformed by riveting is difficult to elastically deform in the radial direction. That is, the rotor 2 that does not have a relief portion around the magnet insertion hole 21b makes it difficult to release the force of holding the magnet 22 generated by riveting. Moreover, the rotor 2 does not have a space as a relief portion around the magnet 22, so it is possible to suppress the reduction of magnetic properties.

[0078] In the above-mentioned structure, in the riveting step S3, the rotor core 21 is riveted in a state where the rotor core 21 is further pressurized in the stacking direction by the one plate B and the other plate B. Thus, the stacked plurality of steel plates 23 are riveted in a tightly contacted state, so that the force input from the riveting pin A does not escape in the stacking direction but is transmitted along the riveted surface 23b. Therefore, compared with the case where the pair of plates B are not further pressurized in the stacking direction during riveting, the magnet 22 can be more reliably held in the magnet insertion hole 21b.

[0079] In the above structure, the recess B3 extends from the pin insertion hole B1 to the magnet insertion hole 21b when viewed in the stacking direction. Therefore, the portion plastically deformed by caulking between the pin insertion hole B1 and the magnet insertion hole 21b can be moved away from the recess B3.

[0080] The rotor manufacturing method as described above and the rotor manufactured by the manufacturing method as described above can release the excess force applied to the magnet 22 and stably hold the magnet 22 in the magnet insertion hole 21 b.

[0081] (Implementation Method 2)

[0082] (Rotor Structure)

[0083] Next, the rotor 102 according to the second embodiment of the present invention is described. The rotor 102 includes a rotor core 121 and a magnet 22. In the rotor 102, the shape of the steel plates 123 located at both ends of the rotor core 121 in the lamination direction is different from the shape of the steel plates 23 located at both ends of the rotor core 21 in the lamination direction in the first embodiment. Hereinafter, only the configuration different from the first embodiment will be described, and the same reference numerals are given to the same configuration as the first embodiment, and the description thereof will be omitted.

[0084] Figure 8 1 is a perspective view showing a schematic structure of the rotor 102 according to the second embodiment. Figure 8 As shown, the rotor core 121 includes a plurality of steel plates 23 having a predetermined shape and stacked in the thickness direction, and steel plates 123. The steel plates 123 are stacked on both ends in the stacking direction of the plurality of steel plates 23 stacked in the thickness direction.

[0085] The steel plate 123 has an opening 123a constituting a part of the magnet insertion hole 21b. A part of the portion constituting the inner surface 21c of the inner insertion hole in the inner peripheral surface of the opening 123a has two cutout portions cut radially inward. Therefore, two recesses 24 constituted by the cutout portion of the steel plate 123 and the steel plate 23 adjacent to the steel plate 123 are provided at both ends in the stacking direction of the rotor core 121. The two recesses 24 extend radially inward from each magnet insertion hole 21b.

[0086] Fig. 9 yes Figure 8 The IX-IX line section view in Fig. Fig. 9 As shown, the depth of the recess 24 in the stacking direction is the thickness of one steel plate 123. The bottom surface of the recess 24, i.e., the surface of the steel plate 23, is riveted in the stacking direction by the riveting pin A. That is, the bottom surface of the recess 24 is the riveting surface 23b.

[0087] The rotor core 121 is caulked by the caulking surface 23b, so that a portion of the inner insertion hole inner surface 21c is plastically deformed toward the inner side of the magnet insertion hole 21b. That is, the inner insertion hole inner surface 21c of the steel plate 23 riveted in the stacking direction by the caulking pin A, i.e., the inner peripheral surface of the opening 23a, protrudes toward the magnet 22.

[0088] A portion of the inner surface 21c of the inner insertion hole protruding toward the magnet 22 contacts the magnet 22 in the magnet insertion hole 21b. In addition, in the steel plate 23, a portion from the position where the rivet pin A contacts to the magnet insertion hole 21b is plastically deformed to the outside in the stacking direction than the rivet surface 23b. That is, the portion plastically deformed to the outside in the stacking direction by riveting protrudes to the outside in the stacking direction than the position of the riveted steel plate 23 in the stacking direction in the rotor core 121. In addition, the portion of the steel plate 23 plastically deformed to the outside in the stacking direction is located in the recess 24.

[0089] A portion of the inner surface 21c of the inner insertion hole that is plastically deformed by riveting abuts against the magnet 22 in the magnet insertion hole 21b. The magnet 22 is pressed toward the outer surface 21d of the outer insertion hole by a portion of the inner surface 21c of the inner insertion hole. Therefore, the magnet 22 is held in the magnet insertion hole 21b by a portion of the inner surface 21c of the inner insertion hole that is plastically deformed by riveting while being pressed against the outer surface 21d of the outer insertion hole.

[0090] In the above structure, in the rotor core 121, the rivet surface 23b is located at the bottom surface of the recess 24 connected to the magnet insertion hole 21b at least one end in the stacking direction. A portion of the steel plate 23 after riveting and the portion protruding in the stacking direction from the rivet surface 23b is located in the recess 24. Therefore, it is possible to prevent the size of the rotor 102 in the stacking direction from increasing. In addition, the force applied to the magnet 22 by riveting is dispersed by plastic deformation in the stacking direction. Therefore, it is possible to prevent damage to the magnet 22. In addition, when the magnet 22 is fixed to the rotor core 121 by riveting, no excessive stress is generated in the portion of the magnet 22 that contacts the steel plate 23. Therefore, the rotor core 121 can rivet the magnet 22 with a stronger force than in the case where the force applied to the magnet 22 is not dispersed in the stacking direction. As a result, the force required to hold the magnet 22 can be increased within a range where no excessive stress is generated.

[0091] In addition, in the above-mentioned structure, the caulking surface 23b is located in the plurality of steel plates 23 constituting the rotor core 121 and the steel plates 23 from the second end in the stacking direction. Therefore, the portion protruding in the stacking direction from the caulking surface 23b does not protrude in the stacking direction from the end in the stacking direction of the rotor core 121. Therefore, by caulking the rotor core 121 in the stacking direction, the size of the rotor 102 in the stacking direction can be prevented from increasing. In addition, by notching the stacked steel plates 23 and the steel plates 123 at the end in the stacking direction, and using the second steel plate 23 from the end in the stacking direction of the rotor core 121 as the caulking surface 23b, it is possible to suppress the reduction of the magnetic characteristics of the rotor core 121. In addition, the magnet 22 is not applied with excessive force, and is retained in the magnet insertion hole 21b by a stable retaining force.

[0092] This can suppress the magnets 22 from being displaced in the stacking direction due to vibration caused by the rotational motion of the rotor 102 .

[0093] (Method for manufacturing rotor)

[0094] Next, a method for manufacturing the rotor 102 using the rotor core 121 and the magnet 22 composed of a plurality of steel plates 23 and 123 stacked in the thickness direction is described. Hereinafter, only the structures different from the first embodiment are described, and the same symbols are attached to the same structures as the first embodiment, and the description is omitted. In addition, only the riveting in one direction of stacking is described below.

[0095] use Figure 4 A method for manufacturing the rotor 102 according to the second embodiment will be described. Figure 4As shown, the manufacturing method of the rotor 102 of the second embodiment includes a magnet inserting step S1, a rotor core holding step S2, and a riveting step S3. The manufacturing method of the rotor 102 is performed in the order of the magnet inserting step S1, the rotor core holding step S2, and the riveting step S3. In the manufacturing method of the rotor 102 of the second embodiment, a pair of plates B10 is used instead of the pair of plates B used in the manufacturing method of the rotor 2 of the first embodiment. The pair of plates B10 is a shape that does not have the recessed portion B3 in the pair of plates B.

[0096] Fig.10 1 is a diagram showing an example of the magnet insertion step S1 of the second embodiment. Fig.10 As shown, the magnet inserting step S1 is a step of inserting the magnet 22 into the magnet insertion hole 21 b of the rotor core 121 .

[0097] In the magnet insertion step S1, the recess 24 of the rotor core 121 placed on one plate B10 overlaps with the pin insertion hole B1 of one plate B10 when viewed from the stacking direction. The magnet 22 is inserted into the magnet insertion hole 21b until the end in one longitudinal direction contacts the plate B10. Thus, the magnet 22 is maintained in the magnet insertion hole 21b.

[0098] Fig.11 1 is a diagram showing an example of the rotor core holding step S2 of the second embodiment. Fig.11 As shown, the rotor core holding step S2 is a step of pressurizing the rotor core 121 into which the magnets 22 are inserted in the stacking direction by using a pair of plates B10.

[0099] In the rotor core holding step S2, a driving device (not shown) is used to bring the contact surface B2 of the other plate B10 into contact with the end surface in the stacking direction of the other side of the rotor core 121 placed on the plate B10 on one side. When the plate B10 and the steel plate 123 are in contact, the pin insertion holes B1 of the pair of plates B10 overlap with the recessed portion 24 of the rotor core 121 in the stacking direction. Therefore, when viewed from the stacking direction, the recessed portion 24 extends from the pin insertion hole B1 toward the magnet insertion hole 21b. A gap is formed by the recessed portion 24 between the plate B10 on one side and the plate B10 on the other side and the steel plate 123. That is, the recessed portion 24 is formed as an escape portion into which the steel plate 23, which is plastically deformed in the stacking direction by the riveting step S3 described later, enters.

[0100] Next, the rotor core 121 is pressed in the stacking direction by the pair of plates B10 while the pair of plates B10 and the rotor core 121 are in contact with each other. Thus, the rotor core 121 is held by the plates B10 located at both end surfaces in the stacking direction.

[0101] Fig.12 1 is a diagram showing an example of the riveting step S3 of the second embodiment. Fig.12 As shown, the caulking step S3 is a step of caulking the rotor core 121 in the lamination direction using the caulking pins A inserted into the pin insertion holes B1 to hold the magnets 22 in the magnet insertion holes 21b. Hereinafter, only the caulking in the other lamination direction will be described.

[0102] In the caulking step S3, the rotor core 121 is further pressed in the stacking direction by the pair of plates B10. While the rotor core 121 is further pressed in the stacking direction by the pair of plates B10, the caulking pin A is inserted in the stacking direction from the pin insertion hole B1 of the other plate B10 to which the rotor core 121 is caulked.

[0103] The rivet pin A contacts the bottom surface of the recess 24 of the rotor core 121, that is, the rivet surface 23b. The rivet pin A presses the steel plate 23 radially inward of the magnet insertion hole 21b and near the magnet insertion hole 21b in the stacking direction by a driving device (not shown). Thus, the steel plate 23 adjacent to the steel plate 123 is riveted in the stacking direction by the rivet pin A.

[0104] A portion of the inner surface 21c of the inner insertion hole of the rotor core 121 is plastically deformed toward the inside of the magnet insertion hole 21b due to riveting. That is, at least a portion of the recessed portion 24 of the steel plate 23 riveted in the stacking direction by the riveting pin A that is not in contact with the other plate B10 is plastically deformed toward the outside in the stacking direction. The portion that is plastically deformed toward the outside in the stacking direction is located inside the recessed portion 24.

[0105] The portion of the steel plate 23 that is plastically deformed by the riveting of the riveting pin A and that is plastically deformed toward the inside of the magnet insertion hole 21b contacts the magnet 22, and the magnet 22 abuts against the inner surface 21d of the outer insertion hole. Thus, the magnet 22 is held in the magnet insertion hole 21b by the portion of the steel plate 23 that is plastically deformed by the riveting and the inner surface 21d of the outer insertion hole.

[0106] In the manufacturing method constructed as described above, the avoidance portion is a recessed portion 24 located at the end of the rotor core 121 in the stacking direction and recessed in the stacking direction. The riveting surface 23b, i.e., the bottom surface of the recessed portion 24, which is plastically deformed in the stacking direction in the riveting step S30, does not protrude in the stacking direction more than the end surface of the rotor core 121 in the stacking direction. Therefore, by riveting the rotor core 121 in the stacking direction, it is possible to prevent the size of the rotor 102 in the stacking direction from increasing. In addition, in the riveting step S30, a portion of the steel plate 23 that is plastically deformed by riveting and abuts against the magnet 22 is deformed toward the recessed portion 24 located between the riveting surface 23b of the rotor core 121 and the plate B10. That is, the force applied to the magnet 22 by the plastically deformed steel plate 23 is dispersed by the plastic deformation in the stacking direction. Therefore, damage to the magnet 22 can be prevented.

[0107] In the above-mentioned structure, the caulking surface 23b is located in the steel plate 23 of the second and subsequent steel plates 23 from the end in the stacking direction among the plurality of steel plates 23 and the steel plates 123. That is, in the rotor core 121, the steel plates 23 of the second and subsequent steel plates 23 from the end in the stacking direction are caulked. Thus, a recess 24 deeper than the amount of plastic deformation in the stacking direction caused by caulking is formed in the rotor core 121. The steel plate 23 that is plastically deformed in the stacking direction in the caulking step S30 is located in the recess 24. Therefore, even if the recess 24 is plastically deformed in the stacking direction due to caulking, the dimension of the rotor 102 in the stacking direction of the rotor core 121 can be prevented from increasing. In addition, the rotor core 121 has the recess 24 formed by cutting the steel plate 123 at the end in the stacking direction, thereby minimizing the reduction in magnetic properties. In addition, in the caulking step S30, the force applied to the magnet 22 by caulking is dispersed by the plastic deformation in the stacking direction. Therefore, when the magnet 22 is fixed to the rotor core 121 by riveting, no excessive stress is generated in the portion of the magnet 22 that contacts the steel plate 123. Therefore, compared with the case where the force applied to the magnet 22 is not dispersed in the stacking direction, the rotor core 121 can be riveted with a stronger force to the magnet 22. Thus, the force required to hold the magnet 22 can be increased within a range that does not generate excessive stress.

[0108] Thereby, it is possible to release the excess force applied to the magnet 22 and stably hold the magnet 22 in the magnet insertion hole 21 b.

[0109] (Other embodiments)

[0110] The embodiments of the present invention have been described above, but the above embodiments are merely examples for implementing the present invention. Therefore, the present invention is not limited to the above embodiments, and the above embodiments can be appropriately modified and implemented within the scope of the gist thereof.

[0111] In the above-mentioned first embodiment, as the structure of the motor 1, Figure 1 However, the motor can also be Figure 1 That is, as long as the motor is an IPM motor, it may also have Figure 1 Motors with structures other than those specified above.

[0112] In each of the above-mentioned embodiments, one of the pair of inner surfaces constituting the long sides of the magnet insertion hole 21b is located radially inward of the rotor core 21 when viewed from the axial direction. The other of the pair of inner surfaces is located radially outward of the rotor core 21. However, the pair of inner surfaces constituting the long sides of the magnet insertion hole may not be located radially inward or radially outward.

[0113] In the above-mentioned first embodiment, the riveted surface 23b is located radially inward of the magnet insertion hole 21b and is riveted at two locations near the magnet insertion hole 21b. However, the riveting of the riveted surface only needs to be located around the magnet insertion hole. In addition, the number of rivets can be one or more than three.

[0114] In the above-mentioned first embodiment, the pair of plates B has a recessed portion B3 that is recessed from the respective contact surfaces B2 in the thickness direction by the thickness of the steel plate 23. In addition, when the pair of plates B and the rotor core 21 are in contact, the two recessed portions B3 are located radially inward of the magnet insertion hole 21b. However, the recessed portion only needs to be located around the magnet insertion hole when the pair of plates and the rotor core are in contact. In addition, the number of recessed portions around each magnet insertion hole may be one, or may be three or more.

[0115] In each of the above-mentioned embodiments, in the magnet inserting step S1, the rotor core 21, 121 is placed on the plates B, B10. However, in the magnet inserting step, the rotor core may be placed on a plate without a pin insertion hole. In this case, in the rotor core holding step, the rotor core is pressed from one end surface in the stacking direction of the rotor core through the plate. In addition, in the riveting step, one end of the rotor core in the stacking direction is riveted by a riveting pin.

[0116] In each of the above-mentioned embodiments, in the riveting step S3, the rotor cores 21 and 121 are riveted in the stacking direction by the riveting pins A while being further pressurized in the stacking direction by the plates B and B10. However, in the riveting step, the rotor cores may be riveted in the stacking direction by the riveting pins without being further pressurized in the stacking direction by the plates.

[0117] In the above-mentioned embodiments, the escape portion extends from the pin insertion hole B1 toward the magnet insertion hole 21b when viewed from the stacking direction. However, the escape portion only needs to be formed between the pin insertion hole and the magnet insertion hole when viewed from the stacking direction.

[0118] In the above-mentioned second embodiment, the steel plates 123 located at both ends of the rotor core 121 in the stacking direction have cutouts. The cutouts are cut radially inward from a portion of the portion of the inner peripheral surface of the opening 123a that constitutes the inner surface 21c of the inner insertion hole. However, the cutouts may also be through holes that penetrate in the thickness direction of the steel plates located at both ends of the rotor core in the stacking direction and into which the rivet pins can be inserted. In addition, when viewed from the stacking direction, the through holes only need to be formed between the pin insertion hole and the magnet insertion hole.

[0119] In the above-mentioned second embodiment, the steel plates 123 having the cutouts are stacked on both stacking direction ends of the rotor core 121. However, the steel plates having the cutouts may be stacked on one stacking direction end of the rotor core. That is, the rotor core may have a recessed portion formed only on one stacking direction end of the rotor core.

[0120] In the above-mentioned second embodiment, the depth of the concave portion 24 formed in the rotor core 121 in the stacking direction is the same as the thickness of one steel plate 123. However, the depth of the concave portion formed in the rotor core in the stacking direction may be shallower or deeper than the thickness of one steel plate. That is, the rotor core may have a plurality of steel plates with cutouts at both ends in the stacking direction. In addition, the steel plate with the cutout may have a shape in which a portion is recessed in the stacking direction.

[0121] In the above-mentioned second embodiment, the recess 24 is located radially inward of the magnet insertion hole 21b in the rotor core 121. In addition, the two recesses 24 are located radially inward of the magnet insertion hole 21b. However, the recesses only need to be located around the magnet insertion hole. In addition, the number of recesses around each magnet insertion hole may be one, or may be three or more. (1)

[0123] A method for manufacturing a rotor, the rotor having a plurality of steel plates stacked in a thickness direction and magnets penetrating the plurality of steel plates in the stacking direction, and the magnets located in the magnet insertion holes are held in the rotor core by riveting the rotor core. The method for manufacturing the rotor comprises: a magnet inserting step of inserting the magnets into the magnet insertion holes; a rotor core holding step of covering at least a portion of the end face in the stacking direction of the rotor core into which the magnets are inserted, from the stacking direction, using a plate having a pin insertion hole into which a rivet pin for riveting the rotor core can be inserted, and applying pressure to at least one end face in the stacking direction of the rotor core using the plate; and a riveting step of riveting the rotor core in the stacking direction using a rivet pin inserted into the pin insertion hole to hold the magnets in the magnet insertion hole. In the rotor core holding step, the rotor core is held in a state where an escape portion is provided between the rivet surface contacted by the rivet pin and the plate, into which the plastically deformed steel plate enters. In the riveting step, the rotor core held by the plate is riveted in the stacking direction using the rivet pin. (2)

[0125] In the rotor manufacturing method described in (1), the escape portion is a recessed portion located at at least one end of the rotor core in the stacking direction and recessed in the stacking direction. In the riveting step, the bottom surface of the recessed portion is riveted in the stacking direction using a riveting pin inserted into the pin insertion hole. (3)

[0127] In the rotor manufacturing method described in (1) or (2), the caulking surface is located on a steel plate other than the steel plate with which the plate contacts among the plurality of steel plates. (4)

[0129] In the rotor manufacturing method described in (1), the relief portion is a recessed portion located on a contact surface of the plate that contacts the rotor core and is recessed outward in the stacking direction from the contact surface. In the riveting step, at least one stacking direction end of the rotor core is riveted in the stacking direction using a riveting pin inserted into the pin insertion hole as the riveting surface. (5)

[0131] In the rotor manufacturing method described in any one of (1) to (4), in the caulking step, the rotor core is caulked in a state where the rotor core is further pressurized in the laminating direction by the plate. (6)

[0133] In the rotor manufacturing method described in any one of (1) to (5), the escape portion extends from the pin insertion hole to the magnet insertion hole when viewed in the lamination direction.

[0134] (7) A rotor comprising: a rotor core having a plurality of steel plates stacked in a thickness direction and a magnet insertion hole penetrating the plurality of steel plates in the stacking direction; and a magnet inserted into the magnet insertion hole, the magnet being held in the magnet insertion hole of the rotor core. A portion of the rotor core that contacts the magnet by riveting protrudes in the stacking direction from a riveted surface of the rotor core. (8)

[0136] In the rotor described in (7), the rotor core has a recessed portion connected to the magnet insertion hole at at least one end portion in the lamination direction, and the bottom surface of the recessed portion is the caulking surface. (9)

[0138] In the rotor described in (7) or (8), the caulking surface is located on a steel plate other than a steel plate located at the at least one end in the stacking direction among the plurality of steel plates.

[0139] (10) An IPM motor comprising: a rotor as described in any one of (7) to (9); and a stator having a stator coil and a stator core.

[0140] Availability in production

[0141] The present invention can be used for a method for manufacturing a rotor, a rotor, and an IPM motor having the rotor.

[0142] Explanation of symbols

[0143] 1—motor (IPM motor), 2, 102—rotor, 3—stator, 4—housing, 20—shaft, 21, 121—rotor core, 21a—through hole, 21b—magnet insertion hole, 21c—inner surface of inner insertion hole, 21d—inner surface of outer insertion hole, 22—magnet, 23, 123—steel plate, 23a, 123a—opening, 23b—riveted surface, 23c—riveted mark, 24, B3—recess, 31—stator core, 32—stator coil, S1—magnet insertion process, S2—rotor core holding process, S3—riveting process, A—riveting pin, B, B10—plate, B1—pin insertion hole, B2—contact surface, P—center axis.

Claims

1. A method for manufacturing a rotor, the rotor comprising a plurality of steel plates stacked in a thickness direction and a magnet insertion hole penetrating the plurality of steel plates in a stacking direction, wherein a magnet located in the magnet insertion hole is held in the rotor core by riveting the rotor core, The above-mentioned method for manufacturing a rotor is characterized by comprising: A magnet inserting step of inserting the magnet into the magnet insertion hole; a rotor core holding step of covering at least a portion of an end surface in the stacking direction of the rotor core into which the magnet is inserted, from a stacking direction, using a plate having a pin insertion hole into which a caulking pin for caulking the rotor core can be inserted, and applying pressure to at least one end surface in the stacking direction of the rotor core using the plate in the stacking direction; and a riveting step of riveting the rotor core in a lamination direction using a riveting pin inserted into the pin insertion hole to hold the magnet in the magnet insertion hole; In the rotor core holding step, the rotor core is held in a state where a relief portion into which the plastically deformed steel plate enters is provided between the caulking surface contacted by the caulking pin and the plate. In the caulking step, the rotor core held by the plates is caulked in a laminating direction by the caulking pins.

2. The method for manufacturing a rotor according to claim 1, characterized in that: The escape portion is a recessed portion located at at least one end of the rotor core in the stacking direction and recessed in the stacking direction. In the caulking step, the caulking is performed in the stacking direction using the caulking pin inserted into the pin insertion hole, with the bottom surface of the recessed portion serving as the caulking surface.

3. The method for manufacturing a rotor according to claim 1 or 2, characterized in that: The caulking surface is located on a steel plate other than the steel plate with which the plate contacts among the plurality of steel plates.

4. The method for manufacturing a rotor according to claim 1, characterized in that: The escape portion is a recessed portion located on a contact surface of the plate that contacts the rotor core and is recessed from the contact surface toward the outside in the stacking direction. In the caulking step, at least one lamination direction end portion of the rotor core is caulked in the lamination direction using the caulking pin inserted into the pin insertion hole as the caulking surface.

5. The method for manufacturing a rotor according to claim 1, characterized in that: In the caulking step, the rotor core is caulked in a state where the rotor core is further pressurized in a laminating direction by the plate.

6. The method for manufacturing a rotor according to claim 1, characterized in that: The escape portion extends from the pin insertion hole to the magnet insertion hole when viewed in the stacking direction.

7. A rotor comprising: a rotor core including a plurality of steel plates stacked in a thickness direction and magnet insertion holes penetrating through the plurality of steel plates in a stacking direction; and A magnet is inserted into the magnet insertion hole. The magnet is held in the magnet insertion hole of the rotor core. The above rotor is characterized in that A portion of the rotor core that contacts the magnet by caulking protrudes in a laminating direction relative to a caulking surface of the rotor core that is caulked.

8. The rotor according to claim 7, characterized in that The rotor core has a recessed portion connected to the magnet insertion hole at at least one end in the stacking direction. The bottom surface of the recessed portion is the caulking surface.

9. The rotor according to claim 7, characterized in that The caulking surface is located on a steel plate other than a steel plate located at the at least one end in the stacking direction among the plurality of steel plates.

10. An IPM motor, characterized in that: have: The rotor of claim 7; and The stator comprises a stator coil and a stator core.

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