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EP-4742503-A1 - METHOD OF MANUFACTURING ROTATION ELECTRIC MACHINE ROTOR AND ROTATION ELECTRIC MACHINE ROTOR

EP4742503A1EP 4742503 A1EP4742503 A1EP 4742503A1EP-4742503-A1

Abstract

Disclosed is a method of manufacturing a rotation electric machine rotor, the method including a step of preparing a rotor core (32) having an annular shape when viewed in an axial direction and having a magnet hole (321, 322) in the axial direction and a first through hole (324) in the axial direction, an injection step of injecting a first molten material brought into a molten state by heating into the first through hole (324), and a magnet disposing step of disposing a permanent magnet (61, 62) in the magnet hole (321, 322) by injecting a second molten material brought into a molten state by heating into the magnet hole (321, 322) after the injection step, wherein the magnet disposing step includes fixing a magnet for the permanent magnet (61, 62) inserted into the magnet hole (321, 322) in the magnet hole (321, 322) as the second molten material is cured, or forming a bonded magnet for the permanent magnet (61, 62) in the magnet hole (321, 322) as the second molten material containing a magnet powder is cured.

Inventors

  • ADACHI, AKIFUMI

Assignees

  • AISIN CORPORATION

Dates

Publication Date
20260513
Application Date
20251021

Claims (7)

  1. A method of manufacturing a rotation electric machine rotor, the method comprising: a step of preparing a rotor core (32) having an annular shape when viewed in an axial direction and having a magnet hole (321, 322) in the axial direction and a first through hole (324) in the axial direction; an injection step of injecting a first molten material brought into a molten state by heating into the first through hole (324); and a magnet disposing step of disposing a permanent magnet (61, 62) in the magnet hole (321, 322) by injecting a second molten material brought into a molten state by heating into the magnet hole (321, 322) after the injection step, wherein the magnet disposing step includes fixing a magnet for the permanent magnet (61, 62) inserted into the magnet hole (321, 322) in the magnet hole (321, 322) as the second molten material is cured, or forming a bonded magnet for the permanent magnet (61, 62) in the magnet hole (321, 322) as the second molten material containing a magnet powder is cured.
  2. The method of manufacturing a rotation electric machine rotor according to Claim 1, wherein the magnet disposing step is performed in a state where a temperature of the rotor core (32) is increased by heat from the first molten material injected in the injection step.
  3. The method of manufacturing a rotation electric machine rotor according to Claim 1 or 2, wherein a melting point of the first molten material is higher than a melting point of the second molten material.
  4. The method of manufacturing a rotation electric machine rotor according to any one of Claims 1 to 3, the method further comprising: a step of preparing an end plate (35A, 35B) having a second through hole (352A) or a bottomed hole (352B) in the axial direction; and a setting step of setting the end plate (35A, 35B) on an axial end face of the rotor core (32) in a relationship in which the second through hole (352A) or the bottomed hole (352B) of the end plate (35A, 35B) overlaps the first through hole (324) of the rotor core (32) when viewed in the axial direction, wherein the injection step is performed after the setting step, and includes injecting the first molten material into the second through hole (352A) or the bottomed hole (352B).
  5. The method of manufacturing a rotation electric machine rotor according to any one of Claims 1 to 4, wherein the rotor core (32) is formed by stacking a plurality of steel plates in the axial direction.
  6. A rotation electric machine rotor comprising: a rotor core (32) having an annular shape when viewed in an axial direction and having a magnet hole (321, 322) in the axial direction and a first through hole (324) in the axial direction; a sintered magnet fixed to the magnet hole (321, 322) with a fixing resin or a bonded magnet disposed in the magnet hole (321, 322); and a material curing unit formed in the first through hole (324) and formed by curing a molten material brought into a molten state by heating.
  7. The rotation electric machine rotor according to Claim 6, further comprising: an end plate (35A, 35B) disposed on an axial end face of the rotor core (32) and having a second through hole (352A) or a bottomed hole (352B) in the axial direction, wherein the first through hole (324) of the rotor core (32) and the second through hole (352A) or the bottomed hole (352B) of the end plate (35A, 35B) overlap each other when viewed in the axial direction, and wherein the material curing unit is formed continuously in the first through hole (324), and the second through hole (352A) or the bottomed hole (352B), in the axial direction.

Description

TECHNICAL FIELD The present disclosure relates to a method of manufacturing a rotation electric machine rotor and a rotation electric machine rotor. BACKGROUND DISCUSSION A known technique is disclosed in JP 2008-54376 A in which a resin material in the molten state is injected into a magnet hole of a rotor core to fix a permanent magnet in the magnet hole. In the step of injecting a resin material in the molten state into the rotor core, the rotor core is required to be preheated for curing when the resin material is a thermosetting resin, and for enhancing fluidity when the resin material is a thermoplastic resin. As such a preheating method, for example, there is a method of applying heat from the outside (surroundings) of the rotor core by a heating device in a state where the rotor core is sandwiched between the upper mold and the lower mold. However, in the preheating method as described above, heat transfer to the inside of the rotor core takes a relatively long time, and it is difficult to reduce the preheating time. Therefore, in an aspect, an object of the present disclosure is to reduce the preheating time in a method of manufacturing a rotation electric machine rotor and to provide a rotation electric machine rotor having a structure capable of reducing a preheating time. A need thus exists for a rotation electric machine rotor which is not susceptible to the drawback mentioned above. SUMMARY In an aspect, disclosed is a method of manufacturing a rotation electric machine rotor, the method including a step of preparing a rotor core having an annular shape when viewed in an axial direction and having a magnet hole in the axial direction and a first through hole in the axial direction, an injection step of injecting a first molten material brought into a molten state by heating into the first through hole, and a magnet disposing step of disposing a permanent magnet in the magnet hole by injecting a second molten material brought into a molten state by heating into the magnet hole after the injection step, wherein the magnet disposing step includes fixing a magnet for the permanent magnet inserted into the magnet hole in the magnet hole as the second molten material is cured, or forming a bonded magnet for the permanent magnet in the magnet hole as the second molten material containing a magnet powder is cured. In an aspect, according to the present disclosure, it is possible to reduce a preheating time in a method of manufacturing a rotation electric machine rotor, or to provide the rotation electric machine rotor having a structure capable of reducing a preheating time. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and additional features and characteristics of this disclosure will become more apparent from the following detailed description considered with the reference to the accompanying drawings, wherein: Fig. 1 is a cross-sectional view schematically illustrating a cross-sectional structure of a motor according to an embodiment;Fig. 2 is a perspective view of a rotor from which an end plate and a nut are removed;Fig. 3 is a perspective view of the end plate when viewed from the axially outside;Fig. 4 is a perspective view of the end plate when viewed from the axially inside;Fig. 5 is a perspective view illustrating an end plate integrated with a rotor shaft;Fig. 6 is a schematic flowchart illustrating a flow of an example of a method of manufacturing a rotor;Fig. 8 is a cross-sectional view of part of a workpiece passing through one through hole;Fig. 9 is an enlarged view of part Q9 in Fig. 8;Fig. 10 is an explanatory view of a positional relationship between two injection molding machines for a workpiece on a conveyance unit in a resin injection step;Fig. 11 is an explanatory diagram of a positional relationship between two injection molding machines for a workpiece on a conveyance unit in a magnet fixing step; andFig. 12 is a schematic flowchart illustrating a flow of another example of the method of manufacturing the rotor. DETAILED DESCRIPTION Hereinafter, each embodiment will be described in detail with reference to the accompanying drawings. Note that the dimensional ratios in the drawings are merely examples, and the dimensional ratios are not limited thereto, and shapes and the like in the drawings may be partially exaggerated for convenience of description. In addition, in the drawings, only some of a plurality of parts having the same attribute may be denoted by reference numerals for the sake of clarity. Fig. 1 is a cross-sectional view schematically illustrating a cross-sectional structure of a motor 1 according to an embodiment. Fig. 2 is a perspective view of a rotor 30 in a state where an end plate 35A and a nut 36 are removed. Note that, in Fig. 2 and the like, for the sake of visibility, there is a case where only some of a plurality of parts having the same attribute is assigned with reference numerals. Fig. 1 illustrates a rotation axis 12 of the motor 1. In the followin