Manufacturing apparatus and method for a stator for a rotating electric machine

Abstract

To enhance welding quality by forming an appropriate space environment for a laser irradiation path from laser irradiation means to a welding target portion.SOLUTION: A device for manufacturing a stator for a rotary electric machine includes: a jig for forming a cylindrical hollow section that forms a state in which tip sections of one conductor piece and the other conductor piece for forming the stator of the rotary electric machine are in contact with each other, and causing each of the tip sections in contact with each other to communicate with an outside; laser irradiation means for emitting a laser beam toward the tip sections in a contact state via the hollow section; and gas supply means for supplying a gas to the hollow section.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present disclosure relates to an apparatus for manufacturing a stator for a rotating electric machine and a method for manufacturing a stator for a rotating electric machine. [Background technology]

[0002] A method for manufacturing a stator is known that involves clamping the ends of one coil piece and another coil piece for forming a stator coil for a rotating electric machine in abutting relationship with each other, and welding the ends together by irradiating a laser beam onto a welding target area related to the abutting ends (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-48359 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when laser welding the ends of the coil pieces as described above, it is necessary to irradiate the laser beam from the laser irradiation means while exposing the areas to be welded to the laser irradiation means, and it is important from the standpoint of improving welding quality to create an appropriate spatial environment for the laser irradiation path from the laser irradiation means to the areas to be welded.

[0005] Therefore, in one aspect, the present disclosure has an object to improve welding quality by forming an appropriate spatial environment for a laser irradiation path from a laser irradiation means to a location to be welded. [Means for solving the problem]

[0006] According to one aspect, a jig is provided for forming a state in which a tip end portion of one conductor piece and a tip end of another conductor piece for forming a stator of a rotating electric machine are in contact with each other, and for forming a cylindrical cavity portion that connects the tip ends in the contacted state to the outside; a laser irradiation means for irradiating a laser beam from outside through the cavity toward the tip portion in the abutting state; and a gas supplying means for supplying a gas to the cavity. Effect of the Invention

[0007] According to one aspect, the present disclosure makes it possible to improve welding quality by forming an appropriate spatial environment for a laser irradiation path from a laser irradiation means to a location to be welded. [Brief description of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing a schematic cross-sectional structure of a motor according to an embodiment; [Diagram 2] FIG. 2 is a plan view of the stator core in a single component state. [Diagram 3] 3A and 3B are diagrams illustrating a pair of coil pieces to be assembled to a stator core. [Figure 4] FIG. 2 is a perspective view of the periphery of a coil end of a stator. [Diagram 5] FIG. 4 is a perspective view showing a part of a coil piece of the same phase. [Figure 6] FIG. 2 is a schematic front view of one coil piece. [Figure 7] 1 is a diagram showing the tip portions of the coil pieces joined together and their vicinity; FIG. [Figure 8] 8 is a cross-sectional view taken along line AA in FIG. 7 passing through the points to be welded. [Figure 9] FIG. 1 is a schematic diagram showing a manufacturing apparatus including a jig. [Figure 10] FIG. [Figure 11] 1 is a two-view diagram showing a side view of the jig and a cross-sectional view taken along line BB. FIG. [Figure 12] FIG. 2 is a diagram showing a plan view and two cross-sectional views of the jig in a three-view format. [Figure 13] 1 is a flowchart illustrating a general flow of the present manufacturing method. [Figure 14] FIG. 4 is an explanatory diagram of a gas supplying step in the present manufacturing method. [Figure 15] FIG. 4 is an explanatory diagram of a gas supplying step in the present manufacturing method. [Figure 16] FIG. 4 is an explanatory diagram of a welding step in the present manufacturing method. [Figure 17] FIG. 4 is an explanatory diagram of a welding step in the present manufacturing method. [Figure 18] FIG. 13 is an explanatory diagram of other applicable welding target portions. [Figure 19] FIG. 13 is an explanatory diagram illustrating another jig configuration. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Each embodiment will be described in detail below with reference to the accompanying drawings. Note that the dimensional ratios in the drawings are merely examples and are not intended to be limiting, and shapes and the like in the drawings may be partially exaggerated for the sake of explanation. Note that in this specification, the word "predetermined" is used to mean "predetermined in advance."

[0010] FIG. 1 is a cross-sectional view that shows a schematic cross-sectional structure of a motor 1 according to an embodiment.

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

[0012] The motor 1 may be a motor for driving a vehicle, for example, used in a hybrid vehicle or an electric vehicle, but the motor 1 may also be used for any other purpose.

[0013] The motor 1 is an inner rotor type, and the stator 21 is provided so as to surround the radial outside of the rotor 30. The radial outside of the stator 21 is fixed to the motor housing 10. The central axis of the stator 21 is the same as the rotating shaft 12.

[0014] The rotor 30 is disposed radially inside the stator 21. The rotor 30 includes a rotor core 32 and a rotor shaft 34. The rotor core 32 is fixed to the radially outside of the rotor shaft 34 and rotates integrally with the rotor shaft 34. The rotor shaft 34 is rotatably supported by the motor housing 10 via bearings 14a and 14b. The rotor shaft 34 defines the rotating shaft 12 of the motor 1.

[0015] Rotor core 32 is formed, for example, from laminated steel plates of a circular magnetic material. Permanent magnets 321 are inserted inside rotor core 32. The number and arrangement of permanent magnets 321 are optional. In a modified example, rotor core 32 may be formed from a green compact obtained by compressing and solidifying magnetic powder.

[0016] End plates 35A, 35B are attached to both axial sides of rotor core 32. End plates 35A, 35B may have a function of adjusting imbalance of rotor 30 (a function of eliminating imbalance by cutting or the like) in addition to a function of supporting rotor core 32.

[0017] As shown in FIG. 1, the rotor shaft 34 has a hollow portion 34A. The hollow portion 34A extends over the entire axial length of the rotor shaft 34. The hollow portion 34A may function as an oil passage. For example, as shown by an arrow R1 in FIG. 1, oil is supplied to the hollow portion 34A from one axial end side, and the oil flows along the radially inner surface of the rotor shaft 34, thereby cooling the rotor core 32 from the radially inner side. In addition, the oil flowing along the radially inner surface of the rotor shaft 34 may be ejected radially outward through oil holes 341, 342 formed at both ends of the rotor shaft 34 (arrows R5, R6) and used to cool the coil ends 220A, 220B.

[0018] 1 shows a motor 1 having a specific structure, the structure of the motor 1 is arbitrary as long as it has a stator coil 24 (described later) joined by welding. Thus, for example, the rotor shaft 34 may not have a hollow portion 34A, or may have a hollow portion whose inner diameter is significantly smaller than that of the hollow portion 34A. Furthermore, while FIG. 1 shows a specific cooling method, the cooling method of the motor 1 is arbitrary. Thus, for example, an oil introduction pipe inserted into the hollow portion 34A may be provided, or oil may be dripped from an oil passage in the motor housing 10 from the radial outside toward the coil ends 220A, 220B.

[0019] 1 shows an inner rotor type motor 1 in which the rotor 30 is disposed inside the stator 21, but the motor 1 may be applied to other types of motors. For example, the motor 1 may be applied to an outer rotor type motor in which the rotor 30 is disposed concentrically outside the stator 21, or a dual rotor type motor in which the rotor 30 is disposed both outside and inside the stator 21.

[0020] Next, the configuration of the stator 21 will be described in detail with reference to FIG. 2 and subsequent figures.

[0021] Fig. 2 is a plan view of the stator core 22 in a single component state. Fig. 3 is a schematic diagram of a pair of coil pieces 52 assembled to the stator core 22. Fig. 3 shows the relationship between the pair of coil pieces 52 and the slots 220 in a state in which the radially inner side of the stator core 22 is developed. In Fig. 3, the stator core 22 is shown by dotted lines, and part of the slots 220 is not shown. Fig. 4 is a perspective view of the periphery of the coil end 220A of the stator 21. Fig. 5 is a perspective view showing part of the coil pieces 52 of the same phase.

[0022] The stator 21 includes a stator core 22 and a stator coil 24 (see FIG. 1).

[0023] The stator core 22 is made of, for example, laminated steel plates of a magnetic material having an annular shape, but in a modified example, the stator core 22 may be formed of a green compact obtained by compressing and solidifying magnetic powder. The stator core 22 may be formed of a divided core divided in the circumferential direction, or may not be divided in the circumferential direction. A plurality of slots 220 around which the stator coil 24 is wound are formed on the radially inner side of the stator core 22. Specifically, as shown in FIG. 2, the stator core 22 includes an annular back yoke 22A and a plurality of teeth 22B extending radially inward from the back yoke 22A, and the slots 220 are formed between the plurality of teeth 22B in the circumferential direction. The number of slots 220 is arbitrary, but in this embodiment, as an example, 48 slots are used.

[0024] The stator coil 24 includes a U-phase coil, a V-phase coil, and a W-phase coil (hereinafter, when U, V, and W are not distinguished from each other, they are referred to as "phase coils"). The base end of each phase coil is connected to an input terminal (not shown), and the end of each phase coil is connected to the end of the other phase coil to form a neutral point of the motor 1. In other words, the stator coil 24 is star-connected. However, the connection mode of the stator coil 24 may be changed as appropriate depending on the required motor characteristics, etc. For example, the stator coil 24 may be delta-connected instead of star-connected.

[0025] Each phase coil is formed by joining a plurality of coil pieces 52. Fig. 6 is a schematic front view of one coil piece 52. The coil pieces 52 are in the form of segment coils obtained by dividing the phase coil into units that are easy to assemble (for example, units that can be inserted into two slots 220). The coil pieces 52 are formed by covering a linear conductor (rectangular wire) 60 having a rectangular cross section with an insulating coating 62. In this embodiment, the linear conductor 60 is formed of copper, as an example. However, in a modified example, the linear conductor 60 may be formed of another conductive material such as iron.

[0026] Before being assembled to the stator core 22, the coil pieces 52 may be formed into a substantially U-shape having a pair of straight portions 50 and a connecting portion 54 connecting the pair of straight portions 50. When assembling the coil pieces 52 to the stator core 22, the pair of straight portions 50 are inserted into the slots 220 (see FIG. 3). As a result, as shown in FIG. 3, the connecting portion 54 extends in the circumferential direction so as to straddle the teeth 22B (and the slots 220 accordingly) at the other axial end side of the stator core 22. The number of slots 220 straddled by the connecting portion 54 is arbitrary, but is three in FIG. 3. After being inserted into the slots 220, the straight portions 50 are bent in the circumferential direction midway as shown by the two-dot chain line in FIG. 6. As a result, the straight portion 50 becomes a leg portion 56 extending axially within the slot 220 and a transition portion 58 extending circumferentially at one axial end side of the stator core 22 .

[0027] In Fig. 6, the pair of straight portions 50 are bent in a direction away from each other, but this is not limited thereto. For example, the pair of straight portions 50 may be bent in a direction toward each other. The stator coil 24 may also have a neutral point coil piece for connecting the ends of the three phase coils to form a neutral point.

[0028] A plurality of leg portions 56 of the coil pieces 52 shown in Fig. 6 are inserted into one slot 220, lined up in the radial direction. Therefore, a plurality of circumferentially extending jumper portions 58 are lined up in the radial direction at one axial end side of the stator core 22. As shown in Figs. 3 and 5, the jumper portion 58 of one coil piece 52 protruding from one slot 220 and extending to one circumferential side is joined to the jumper portion 58 of another coil piece 52 protruding from another slot 220 and extending to the other circumferential side.

[0029] Here, as described above, the coil pieces 52 are covered with the insulating coating 62, but the insulating coating 62 is removed only from the tip portion 40. This is to ensure electrical connection with the other coil pieces 52 at the tip portion 40.

[0030] As shown in Figures 5 and 6, the coil piece 52 has an axially outer end surface 42 of the tip portion 40 thereof, i.e., one end surface in the width direction of the coil piece 52 (axially outer end surface 42), which is an arc surface convex outward in the axial direction.

[0031] Fig. 7 is a diagram showing tip portions 40 and the vicinity thereof of coil pieces 52 joined together. Fig. 7 also shows a schematic view of a circumferential range D1 of a portion to be welded 90. Fig. 8 is a cross-sectional view taken along line AA in Fig. 7 which passes through portion to be welded 90.

[0032] When joining the tip portions 40 of the coil pieces 52, one coil piece 52 and another coil piece 52 are butted against each other such that the tip portions 40 form a C-shape in the view shown in Fig. 7 (as viewed in a direction perpendicular to the abutting surface 401). At this time, the two tip portions 40 to be joined to each other may be overlapped in the thickness direction and joined so that the central axes of the respective arcuate surfaces (axially outer end surfaces 42) coincide. By overlapping with the central axes aligned in this manner, even when the bending angle α is relatively large or small, the axially outer lines of the two tip portions 40 to be joined to each other coincide and they can be appropriately overlapped.

[0033] In this case, as shown in ranges D1 and D2, the welding target area 90 extends linearly along the contact surface 401. That is, the welding target area 90 extends linearly over the range D1 with a width of the range D2 when viewed from the irradiation side of the laser beam 110 (see arrow W in FIGS. 7 and 8).

[0034] Here, in this embodiment, welding is used as a joining method when joining the tip portions 40 of the coil pieces 52. In this embodiment, the welding method is not arc welding, as typified by TIG welding, but laser welding using a laser beam source as a heat source. By using laser welding instead of TIG welding, the axial length of the coil ends 220A, 220B can be reduced. That is, in the case of TIG welding, it is necessary to bend the tip portions of the coil pieces to be abutted each other axially outward and extend them in the axial direction, whereas in the case of laser welding, such bending is not necessary, and as shown in FIG. 7, welding can be realized in a state in which the tip portions 40 of the coil pieces 52 to be abutted each other extend in the circumferential direction. As a result, the axial length of the coil ends 220A, 220B can be reduced compared to the case in which the tip portions 40 of the coil pieces 52 to be abutted each other are bent axially outward and extend in the axial direction.

[0035] In laser welding, as shown in Fig. 5, a welding laser beam 110 is applied to a welding target portion 90 of the two abutted tip portions 40. The irradiation direction (propagation direction) of the laser beam 110 is approximately parallel to the axial direction, and is a direction toward the axially outer end faces 42 of the two abutted tip portions 40 from the axially outer side. In the case of laser welding, localized heating is possible, so that only the tip portions 40 and their vicinity can be heated, and damage (carbonization) of the insulating coating 62 can be effectively reduced. As a result, the coil pieces 52 can be electrically connected while maintaining appropriate insulation performance.

[0036] 7, the circumferential range D1 of the welding area 90 is a portion of the entire circumferential range D0 of the axially outer end face 42 at the contact portion between the tip ends 40 of the two coil pieces 52, excluding both ends. This is because it is difficult to ensure a sufficient welding depth (see dimension L1 in FIG. 7) at both ends due to the convex arc surface of the axially outer end face 42. The circumferential range D1 of the welding area 90 may be adapted so as to ensure the necessary joint area, the necessary welding strength, etc. between the coil pieces 52.

[0037] As shown in FIG. 8, the radial range D2 of the welding target area 90 is centered on the contact surface 401 between the tip portions 40 of the two coil pieces 52. The radial range D2 of the welding target area 90 may correspond to the diameter (beam diameter) of the laser beam 110. That is, the laser beam 110 is irradiated in such a manner that the irradiation position changes linearly along the circumferential direction without substantially changing in the radial direction. In other words, the laser beam 110 is moved so that the irradiation position changes linearly parallel to the contact surface 401. This allows the laser beam 110 to be irradiated to the linear welding target area 90 more efficiently than when the irradiation position is changed in a loop (spiral) or zigzag (meandering) shape, for example.

[0038] Next, with reference to FIG. 9 and subsequent figures, a manufacturing device 7 including a jig 70 suitable for laser welding tip portions 40 of coil pieces 52 will be described as part of a manufacturing device for stator 21.

[0039] Fig. 9 is a schematic diagram showing a manufacturing apparatus 7 including a jig 70. Fig. 9 shows a schematic representation of a portion (a portion including a tip portion 40) of each of a pair of coil pieces 52 to be joined.

[0040] As shown in FIG. 9, the manufacturing apparatus 7 includes a jig 70, a gas supplying means 80, and a laser irradiating means 89.

[0041] The jig 70 forms a state in which the tip portions 40 of one coil piece 52 and the other coil piece 52 are in contact with each other for a pair of coil pieces 52, and maintains the state of contact. That is, the jig 70 clamps the pair of coil pieces 52 so that the tip portions 40 of the pair of coil pieces 52 are maintained in contact with each other. Note that, in the following, only the portion of the jig 70 relating to the tip portions 40 of the pair of coil pieces 52 is shown, but the jig 70 may be configured to simultaneously clamp the tip portions 40 of multiple pairs (e.g., 12 pairs) of coil pieces 52. In this case, the jig 70 may be formed in a manner in which the configuration shown in FIG. 9 is continuous in the circumferential direction. Also, in this case, the jig 70 may simultaneously form separate cavities 500 for each pair of the multiple pairs of coil pieces 52. In the case of a configuration in which the tip portions 40 of multiple pairs (e.g., 12 pairs) of coil pieces 52 are clamped simultaneously, the lead time of the welding process can be efficiently shortened compared to the case of clamping the coil pieces one pair at a time.

[0042] In the clamped state where the pair of coil pieces 52 is restrained as described above, the jig 70 forms a cylindrical cavity 500 that communicates the tip portions 40 of the pair of coil pieces 52 (the tip portions 40 in abutting state) with the outside. That is, the jig 70 restrains the pair of coil pieces 52 as described above, and at the same time forms a cylindrical cavity 500 that communicates the tip portions 40 of the pair of coil pieces 52 with the outside. The cavity 500 forms a path (laser irradiation path) of the laser beam 110 from the laser irradiation means 89 to the welding target portion 90 of the tip portions 40. The cavity 500 is preferably in a form in which only the side where the laser beam 110 from the laser irradiation means 89 is incident is open. However, when the jig 70 is formed by two or more jig members (in this embodiment, three jig members 71, 72, 73 as described later) that move relative to each other, a small gap due to the clearance between the jig members may be formed.

[0043] In this embodiment, the jig 70 includes three jig members 71, 72, and 73 that are movable relative to one another. The configurations of the jig members 71, 72, and 73 will be described in detail with reference to FIG.

[0044] The gas supplying means 80 supplies gas to the cavity 500. By appropriately supplying gas to the cavity 500, a desired gas environment can be realized in the cavity 500. In this manner, according to the present embodiment, by having the gas supplying means 80, it is possible to form an appropriate spatial environment for the laser irradiation path from the laser irradiation means 89 to the welding target portion 90.

[0045] In this embodiment, the gas supply means 80 includes a first gas supply means 81 and a second gas supply means 82 .

[0046] The first gas supplying means 81 supplies air as a gas to the cavity 500. The air supplied by the first gas supplying means 81 mainly has a function of removing objects to be removed, such as spatter and soot, which may be generated during laser welding, from the cavity 500. Note that spatter refers to metal particles and the like that are scattered due to disturbance of the molten pool, etc. Note that, from the viewpoint of cost, air is preferable as the gas supplied by the first gas supplying means 81, but other gases such as nitrogen may be used, or a mixture of air and other gases may be used.

[0047] The first gas supply means 81 preferably generates at least one of a positive pressure and a negative pressure that forcibly exhausts the air in the cavity 500 to the outside. In this embodiment, the first gas supply means 81 includes a positive pressure source 811 and a negative pressure source 812 to generate both the positive pressure and the negative pressure that forcibly exhausts the air in the cavity 500 to the outside.

[0048] The positive pressure source 811 is a so-called air blow source, and generates a flow of air to be sprayed into the cavity 500. The positive pressure source 811 may be a compressor, a fan, a blower, or the like.

[0049] Negative pressure source 812 is a so-called vacuum source, and generates a negative pressure that draws in air from inside cavity 500. Negative pressure source 812 may be a vacuum pump, a vacuum blower, an ejector (vacuum generator), or the like.

[0050] In this case, the first gas supply means 81 can generate an air flow that blows away spatters in the cavity 500 by the positive pressure source 811, and can also draw (purge) the air in the cavity 500 by the negative pressure source 812. This makes it possible to effectively remove spatters that may be generated during laser welding from the cavity 500.

[0051] The configuration of the pipelines for communicating each of the positive pressure source 811 and the negative pressure source 812 with the cavity 500 in the first gas supply means 81 will be described in detail with reference to FIG. 10 and subsequent figures.

[0052] The second gas supply means 82 supplies an inert gas to the cavity 500. The inert gas supplied by the second gas supply means 82 mainly functions as a shielding gas (gas that prevents oxidation, nitridation, etc. of the molten metal). The inert gas is arbitrary and may be nitrogen, argon, helium, etc. In this case, the inert gas functioning as a shielding gas can effectively improve the welding quality. In a modified example, carbon dioxide gas may be used instead of or in addition to the inert gas.

[0053] The second gas supply means 82 includes an inert gas source 820. The inert gas source 820 may be in the form of a tank or the like that stores an inert gas or a source thereof. The configuration of the pipeline for communicating the inert gas source 820 and the cavity 500 in the second gas supply means 82 will be described in detail with reference to FIG. 10 and subsequent figures.

[0054] The laser irradiation means 89 irradiates the above-mentioned laser beam 110. The position of the laser irradiation means 89 with respect to the fixed reference position of the jig 70 may be variable or may be constant. That is, the laser irradiation means 89 may be of a movable type or a fixed type.

[0055] The wavelength of the laser beam 110 irradiated by the laser irradiation means 89 is arbitrary, but preferably, the wavelength of the laser beam 110 is a wavelength that forms a green laser. The green laser is a concept that includes not only a laser with a wavelength of 532 nm, i.e., an SHG (Second Harmonic Generation) laser, but also a laser with a wavelength close to 532 nm. In a modified example, a laser with a wavelength of 0.6 μm or less that does not belong to the category of green laser may be used. The wavelength related to the green laser can be obtained by converting the fundamental wavelength generated by, for example, a YAG laser or a YVO4 laser through an oxide single crystal (for example, LBO: lithium triborate).

[0056] In a modified example, an infrared laser (a laser with a wavelength of 1064 nm) may be used. However, the absorption rate of the infrared laser is low, about 10%, for copper, which is the material of the linear conductor 60 of the coil pieces 52. That is, in the case of an infrared laser, most of the laser beam 110 is reflected by the coil pieces 52 and not absorbed. For this reason, a relatively large amount of heat input is required to obtain the required joint area between the coil pieces 52 to be joined, which may cause a large thermal effect and make the welding unstable.

[0057] In contrast, the green laser has a high absorptance of approximately 50% for copper, which is the material of the linear conductor 60 of the coil pieces 52. Therefore, according to this embodiment, it is possible to ensure the necessary bonding area between the coil pieces 52 with a smaller amount of heat input compared to the case of using an infrared laser.

[0058] Next, the configuration of the jig 70 of this embodiment will be further described with reference to FIGS.

[0059] Fig. 10 is an exploded perspective view of the jig 70, and Fig. 11 is a two-plan view of the side view of the jig 70 and a cross-sectional view showing a cross-section along line BB. Fig. 12 is a three-plan view of the jig 70 and cross-sectional views in two directions (cross-sections along lines CC and DD). Figs. 10 to 12 show schematic views of each of a pair of coil pieces 52 to be joined (a portion including the tip portion 40). Hereinafter, the pair of coil pieces 52 refers to the coil pieces 52 to be clamped by the jig 70.

[0060] In Fig. 10, the X direction along the radial direction, the X1 side and the X2 side are defined, and the Y direction along the circumferential direction, the Y1 side and the Y2 side are defined. In addition, in Fig. 10, the Z direction along the axial direction, the Z1 side and the Z2 side are defined. In the following description, the Z direction is the up-down direction, and the Z1 side is the upper side. However, the jig 70 may be disposed in such a manner that the Z direction does not coincide with the direction of gravity.

[0061] The jig 70 includes a jig member 71 (hereinafter also referred to as the "radially inner jig member 71"), a jig member 72 (hereinafter also referred to as the "radially outer jig member 72") arranged radially outer than the jig member 71 (X-direction X2 side), and a jig member 73.

[0062] The radially inner jig member 71 and the radially outer jig member 72 are movable relative to each other. For example, the radially inner jig member 71 is movable in the circumferential direction relative to the radially outer jig member 72. The radially inner jig member 71, in cooperation with the radially outer jig members 72 and 73, is capable of switching the state of the pair of coil pieces 52 between a clamped state in which the pair of coil pieces 52 are constrained to the jig 70 and an unclamped state in which the pair of coil pieces 52 are not constrained to the jig 70. FIGS. 10 to 12 show the jig 70 when the clamped state of the pair of coil pieces 52 is realized.

[0063] The radially inner jig member 71 has mating surfaces 718, 719 that, in a clamped state, radially face the radially outer jig member 72. The mating surface 718 is substantially parallel to the mating surface 719 and is offset radially outward from the mating surface 719. Note that substantially parallel is not intended to be limited to strict parallelism, and is a concept that allows for an error of, for example, about 10%. In this case, the mating surface 718 may be offset radially outward from the mating surface 719 by a dimension corresponding to the thickness (radial thickness) of the pair of coil pieces 52. By utilizing such an offset, the tip portions 40 of the pair of coil pieces 52 can be appropriately restrained (clamped).

[0064] In the clamped state, the radially inner jig member 71 abuts in the circumferential direction against the radially inner coil piece 52 of the pair of coil pieces 52 (see FIG. 12), thereby restricting the circumferential displacement of the radially inner coil piece 52. In addition, in the clamped state, the jig member 71 abuts in the radial direction against the radially inner coil piece 52 of the pair of coil pieces 52 (see FIG. 11), thereby restricting the radial displacement of the pair of coil pieces 52.

[0065] In a clamped state, the radially outer jig member 72 has mating surfaces 728, 729 that radially face the radially inner jig member 71. The mating surface 728 is substantially parallel to the mating surface 729 and is offset radially outward from the mating surface 729. In this case, the mating surface 728 may be offset radially outward from the mating surface 729 by a dimension corresponding to the thickness (radial thickness) of the pair of coil pieces 52. By utilizing such an offset, the tip portions 40 of the pair of coil pieces 52 can be appropriately restrained (clamped).

[0066] In the clamped state, the radially outer jig member 72 abuts circumferentially against the radially outer coil piece 52 of the pair of coil pieces 52 (see Figure 12), thereby restraining the circumferential displacement of the radially outer coil piece 52.

[0067] The jig member 73 is movable in the radial direction relative to the jig member 72 on the radially outer side. In a clamped state, the jig member 73 abuts against the radially outer coil piece 52 of the pair of coil pieces 52 from the radially outer side (see FIG. 11). At this time, the jig member 73 abuts against the overlapping portion (see FIG. 7) of the pair of coil pieces 52 (see FIG. 11). The jig member 73 presses the pair of coil pieces 52 against the jig member 71 on the radially inner side, thereby restricting the radial displacement of the pair of coil pieces 52 (see FIG. 11). That is, the jig member 73 cooperates with the jig member 71 on the radially inner side to clamp the pair of coil pieces 52 in the radial direction, thereby restricting the radial displacement of the pair of coil pieces 52.

[0068] According to such a jig 70 of the present embodiment, a clamped state in which radial and circumferential displacement of the pair of coil pieces 52 is restricted can be formed by using substantially two movable parts (jig member 71 and jig member 73).

[0069] In this embodiment, in the clamped state, the jig 70 forms the above-mentioned cavity 500 above the pair of coil pieces 52. That is, the jig 70 restrains the pair of coil pieces 52 in the circumferential and radial directions below the cavity 500 as described above. The cavity 500 is substantially closed at the lower side (Z-direction Z2 side) by the pair of coil pieces 52 and is open at the upper side (Z-direction Z1 side). Note that the upper opening is for irradiating the laser beam 110 from the laser irradiation means 89 as described above.

[0070] Jig 70 preferably forms hollow portion 500 such that, as viewed in the axial direction, the center of hollow portion 500 is located at the center of the overlapping portion (see FIG. 7) of tip ends 40 of a pair of coil pieces 52. In this case, the radial center of hollow portion 500 is located at the position of abutment surface 401 (see FIG. 8) between tip ends 40 of a pair of coil pieces 52, and the circumferential center of hollow portion 500 is located at the circumferential center of the overlapping portion (the center of circumferential range D1 of welding target point 90 shown in FIG. 7).

[0071] The hollow portion 500 is closed on the radially inner side by a radial side wall portion 706 of the radially inner jig member 71, and on the radially outer side by a radial side wall portion 708 of the radially outer jig member 72.

[0072] One circumferential side (Y1 side) of the hollow portion 500 is closed by a circumferential side wall portion 710 of the radially inner jig member 71 and a circumferential side wall portion 720 of the radially outer jig member 72. The side wall portion 710 and the side wall portion 720 are radially continuous with each other via a slight radial clearance between mating surfaces 718, 728. Note that this clearance may be a minimum dimension that allows the radially inner jig member 71 to move in the circumferential direction relative to the radially outer jig member 72.

[0073] The other circumferential side (Y2 side) of the hollow portion 500 is closed by a circumferential side wall portion 712 of the radially inner jig member 71 and a circumferential side wall portion 722 of the radially outer jig member 72. The side wall portion 712 and the side wall portion 722 are radially continuous with each other via a slight radial clearance between mating surfaces 719, 729. This clearance may be a minimum dimension that allows the radially inner jig member 71 to move circumferentially relative to the radially outer jig member 72.

[0074] The hollow portion 500 has a cross-sectional area (cross-sectional area in the XY plane) that becomes wider toward the upper side. That is, the hollow portion 500 has a tapered shape. The inclination degree of the tapered shape may be set according to the variable range of the irradiation angle of the laser beam 110 from the laser irradiation means 89. This makes it possible to minimize the opening area (opening area communicating with the outside) on the upper side of the hollow portion 500 according to the variable range of the irradiation angle of the laser beam 110. The variable range of the irradiation angle of the laser beam 110 may be determined according to the length (e.g., the length in the circumferential direction) of the welding target portion 90.

[0075] In this embodiment, the jig 70 has a flow path structure that connects the positive pressure source 811 , the negative pressure source 812 , and the inert gas source 820 of the gas supply means 80 described above to the cavity 500 .

[0076] Specifically, in this embodiment, the jig 70 includes a blow flow path 851, a vacuum flow path 852, and an inert gas flow path 853 as flow path structures that connect each of the positive pressure source 811, the negative pressure source 812, and the inert gas source 820 to the hollow portion 500.

[0077] The blow flow path 851 communicates the positive pressure source 811 with the cavity 500. That is, one end of the blow flow path 851 communicates with the positive pressure source 811, and the other end opens to the cavity 500. The blow flow path 851 is formed in the jig 70. This makes it possible to easily form the blow flow path 851 that opens at a desired position in the cavity 500. Moreover, the blow flow path 851 is preferably formed in the jig member 71 on the radially inner side of the jig 70. In this case, the opening 8510 (the opening 8510 on the cavity 500 side) of the blow flow path 851 can be directed radially outward, and an air flow (blow) directed radially outward can be formed.

[0078] In the example shown in Fig. 10 to Fig. 12, an opening 8510 of the blow flow passage 851 (opening 8510 on the cavity 500 side) is formed in the radial side wall 706 of the jig member 71 on the radially inner side. That is, the blow flow passage 851 opens radially from the radially inner side relative to the cavity 500. The blow flow passage 851 preferably applies a positive pressure above the tip end 40 (the part to be welded 90) of the pair of coil pieces 52. This makes it possible to form an air flow for removing spatters above the part to be welded 90 in a manner that does not easily hinder accumulation (retention) of an inert gas (described later) near the tip end 40 (the part to be welded 90) of the pair of coil pieces 52.

[0079] The blow flow passage 851 extends linearly in a direction (radial direction) approximately perpendicular to the axial direction in a section immediately before reaching the opening 8510 (the opening 8510 on the cavity 500 side). The term "approximately perpendicular" is intended not to be limited to a strict right angle, and is a concept that allows an error of, for example, about 10%. This makes it possible to realize an air flow that is less likely to hinder the accumulation (retention) of an inert gas described later near the tip end 40 (welding target portion 90) of the pair of coil pieces 52, as compared with a case in which the blow flow passage 851 extends obliquely downward like the pair of inert gas flow passages 853. That is, when the air discharged from the blow flow passage 851 directly hits the tip end 40 (welding target portion 90) of the pair of coil pieces 52, the inert gas described later that is supplied near the tip end 40 (welding target portion 90) of the pair of coil pieces 52 may be blown away and partially replaced with air. In this regard, such inconvenience can be effectively reduced by making the blow flow passage 851 extend linearly substantially within the XY plane in the section immediately before the opening 8510. "Substantially within the XY plane" does not necessarily mean that the blow flow passage 851 is strictly parallel to the XY plane, and is a concept that allows for a certain degree of error (for example, an error of about 10%). Note that in the examples shown in Figs. 10 to 12, the blow flow passage 851 is shown to have a portion extending in the radial direction, but may include a portion extending upward along the axial direction toward the positive pressure source 811 in a section not shown, for example.

[0080] The opening 8510 of the blow flow passage 851 preferably has a relatively small opening area and may be, for example, in the form of a nozzle. In this embodiment, the opening 8510 has a significantly smaller opening area than the opening 8520 (opening 8520 on the cavity 500 side) of the vacuum flow passage 852 described later. This makes it possible to efficiently increase the flow rate of air discharged from the opening 8510 into the cavity 500 through the blow flow passage 851. Note that the higher the flow rate of air discharged from the opening 8510 into the cavity 500 through the blow flow passage 851, the more improved the ability to remove spatter that may occur during laser welding from the cavity 500 (by guiding it into the vacuum flow passage 852).

[0081] The vacuum flow path 852 communicates the negative pressure source 812 with the cavity 500. That is, one end of the vacuum flow path 852 communicates with the negative pressure source 812, and the other end opens to the cavity 500. The vacuum flow path 852 is formed in the jig 70. This makes it possible to easily form the vacuum flow path 852 that opens at a desired position in the cavity 500. In addition, the vacuum flow path 852 is preferably formed in the jig member 72 on the radially outer side of the jig 70. In this case, it becomes easy to discharge the air (air that may contain sputters) in the cavity 500 collected via the vacuum flow path 852 to the radially outer side of the jig 70. Note that a relatively larger space is available on the radially outer side than on the radially inner side, and this makes it easy to arrange a configuration (not shown) for processing the air (air that may contain sputters) in the cavity 500 collected via the vacuum flow path 852.

[0082] In the example shown in Fig. 10 to Fig. 12, the opening 8520 of the vacuum flow passage 852 (the opening 8520 on the cavity 500 side) is formed in the radial side wall 708 of the jig member 72 on the radial outer side. That is, the vacuum flow passage 852 opens radially from the radial outer side to the cavity 500. The vacuum flow passage 852 preferably applies negative pressure above the pair of coil pieces 52 (the welding target portion 90). This makes it possible to form an air flow for removing spatters above the welding target portion 90 in a manner that does not easily hinder accumulation (retention) of an inert gas, which will be described later, near the tip end 40 (the welding target portion 90) of the pair of coil pieces 52.

[0083] In the examples shown in Figures 10 to 12, the vacuum flow path 852 is shown to have a radially extending portion, but it may also include a portion (e.g., a chimney-shaped flow path portion) that extends upward along the axial direction toward the negative pressure source 812, for example, in a section not shown.

[0084] The vacuum flow path 852 preferably faces the blow flow path 851 in the radial direction with the cavity 500 interposed therebetween. In this case, the opening 8520 (the opening 8520 on the cavity 500 side) of the vacuum flow path 852 preferably faces the opening 8510 of the blow flow path 851 in the radial direction with the cavity 500 interposed therebetween. This allows air (air carrying spatter) discharged from the opening 8510 of the blow flow path 851 to be guided into the vacuum flow path 852 in a linear radial path. Specifically, the vacuum flow path 852 cooperates with the blow flow path 851 to form an air flow (for example, an air flow substantially parallel to the XY plane) that intersects with the Z direction above the tip end 40 (the welding target portion 90) of the pair of coil pieces 52. This effectively forms an air flow that does not easily hinder accumulation (retention) of inert gas, which will be described later, near the tip ends 40 (welding target points 90) of the pair of coil pieces 52. Also, by minimizing the distance of the section passing through cavity 500 from opening 8510 of blow flow path 851 to opening 8520 of vacuum flow path 852, pressure loss is minimized, and positive pressure and negative pressure can be efficiently applied to cavity 500.

[0085] The opening 8520 of the vacuum flow path 852 (the opening 8520 on the cavity 500 side) preferably has a relatively large opening area. In this embodiment, the opening 8520 has a relatively large opening area, and as described above, the opening area is significantly larger than the opening 8510 of the blow flow path 851 (the opening 8510 on the cavity 500 side). This makes it possible to directly guide most of the spatter blown away by the air from the blow flow path 851 to the opening 8520 of the vacuum flow path 852, and efficiently reduce spatter that may adhere to the radial side wall portion 708 (the surface around the opening 8520).

[0086] The inert gas flow path 853 connects the inert gas source 820 to the cavity 500. That is, one end of the inert gas flow path 853 connects to the inert gas source 820, and the other end opens to the cavity 500. The inert gas flow path 853 is formed in the jig 70. This makes it possible to easily form the inert gas flow path 853 that opens to a desired position in the cavity 500.

[0087] The inert gas flow paths 853 are preferably formed in pairs for one cavity 500. This allows the inert gas flows from two directions to be mixed above the tip ends 40 (welding target locations 90) of the pair of coil pieces 52, thereby effectively stabilizing the accumulation (retention) of the inert gas. Note that when the above-mentioned laser welding is performed with the accumulation of the inert gas stabilized, the quality of the welded portion can be effectively improved.

[0088] The inert gas passage 853 preferably opens into the cavity 500 below the opening 8520 of the vacuum passage 852 from the opening 8510 of the blow passage 851. This allows a pool (retention) of inert gas to be formed above the tip 40 (welding target portion 90) of the pair of coil pieces 52 in a manner that is not easily affected by the flow of air supplied by the first gas supply means 81. The speed (flow rate) of the inert gas supplied from the pair of inert gas passages 853 to the cavity 500 is significantly smaller than the speed (flow rate) of the air supplied from the blow passage 851. The inert gas supplied from the pair of inert gas passages 853 to the cavity 500 may be supplied in a manner that compensates for a portion that may be discharged via the vacuum passage 852 without excess or deficiency.

[0089] The pair of inert gas flow paths 853 preferably face each other in the circumferential direction with the hollow portion 500 in between. In this case, the inert gas can be supplied from two directions facing each other in the circumferential direction (directions parallel to the abutment surface 401 between the tip portions 40 of the pair of coil pieces 52), so that the inert gas can be efficiently supplied to the welding target portion 90 located at the center of the circumferential direction in the hollow portion 500. As a result, the distribution of the inert gas above the abutment surface 401 between the tip portions 40 of the pair of coil pieces 52 can be made uniform along the circumferential direction. This makes it possible to improve the welding quality over the entire circumferential range D1 of the welding target portion 90. In a modified example, the inert gas may be supplied from three or more different directions.

[0090] The pair of inert gas flow passages 853 preferably open in the circumferential direction and obliquely downward with respect to the hollow portion 500. This allows the inert gas to be directly supplied from the upper side of the tip portion 40 (welding target portion 90) of the pair of coil pieces 52 toward the tip portion 40 (welding target portion 90) of the pair of coil pieces 52. In this embodiment, as shown in FIG. 12, the pair of inert gas flow passages 853 are inclined in a manner that the angle they form with respect to the XY plane is smaller (for example, an angle of about 45 degrees) than the side wall portion 712 and the side wall portion 710 in the circumferential direction when viewed in the radial direction. However, in a modified example, one or both of the pair of inert gas flow passages 853 may extend linearly in approximately the XY plane in a section immediately before reaching the opening 8530, similar to the blow flow passage 851 described above. The term "approximately in the XY plane" does not need to be strictly parallel to the XY plane, and is a concept that allows a certain degree of error (for example, an error of about 10%).

[0091] The pair of inert gas flow paths 853 are preferably formed in only one of the radially inner jig member 71 and the radially outer jig member 72, while facing each other in the circumferential direction across the hollow portion 500. In this case, the configuration related to the second gas supply means 82 can be arranged more efficiently than when, for example, one inert gas flow path 853 is provided in each of the radially inner jig member 71 and the radially outer jig member 72. For example, when a common inert gas source 820 is connected to the pair of inert gas flow paths 853, it is possible to share part of a path (not shown) for such communication.

[0092] In this embodiment, as an example, the inert gas flow passages 853 are provided in a pair in the radially inner jig member 71. However, in a modified example, the inert gas flow passages 853 may be provided in each of the radially inner jig member 71 and the radially outer jig member 72, or may be provided in a pair in the radially outer jig member 72.

[0093] In this embodiment, since both of the pair of inert gas flow passages 853 are formed in the jig member 71 on the radially inner side, the openings 8530 (openings 8530 on the hollow portion 500 side) of the pair of inert gas flow passages 853 face each other in the circumferential direction while being slightly offset from each other in the radial direction. Specifically, of the pair of inert gas flow passages 853, the inert gas flow passage 853 on the Y-direction Y1 side has an opening 8530 in the side wall portion 710 of the jig member 71 on the radially inner side, and the inert gas flow passage 853 on the Y-direction Y2 side has an opening 8530 in the side wall portion 712 of the jig member 71 on the radially inner side. In this case, as shown in FIG. 12, the openings 8530 of the side wall portion 710 may be formed at a radial position corresponding to the approximate center position in the radial direction of the hollow portion 500 (the position of the abutting surface 401 between the tip portions 40 of the coil pieces 52).

[0094] In this manner, the jig 70 according to the present embodiment can form a clamped state in which the pair of coil pieces 52 are clamped, and in this clamped state, a cavity 500 with only the upper side being substantially open can be formed above the welding target portion 90 between the tip ends 40 of the pair of coil pieces 52. This allows the tip ends 40 to be laser welded together within the highly closed cavity 500, and the effect of the inert gas from the second gas supply means 82 (the effect of improving welding quality) can be promoted.

[0095] Furthermore, according to this embodiment, among the various openings to the cavity 500, the openings 8510, 8520 related to the first gas supply means 81 are located above the opening 8530 of the second gas supply means 82, so that an air flow related to the first gas supply means 81 can be formed in the cavity 500 without significantly impairing the function (function of improving welding quality) of the inert gas supplied from the second gas supply means 82. This makes it possible to remove spatters without significantly impairing the function (function of improving welding quality) of the inert gas, and effectively improve the welding quality.

[0096] Further, according to this embodiment, the opening 8510 of the blow flow passage 851 and the opening 8520 of the vacuum flow passage 852 face each other in the radial direction, while the opening 8530 of the paired inert gas flow passage 853 faces each other in the circumferential direction, so that the blow flow passage 851, the vacuum flow passage 852, and the paired inert gas flow passage 853 can be efficiently formed in the jig 70. For example, when the opening 8510 of the blow flow passage 851 and the opening 8520 of the vacuum flow passage 852 face each other in the radial direction, and the opening 8530 of the paired inert gas flow passage 853 faces each other in the radial direction as well, it becomes difficult to form the blow flow passage 851, the vacuum flow passage 852, and the paired inert gas flow passage 853 in the jig 70 so as not to communicate with each other, and the jig configuration may become complicated. In contrast, according to this embodiment, it is easy to form the blow flow passage 851, the vacuum flow passage 852, and the paired inert gas flow passage 853 in the jig 70 so as not to communicate with each other. However, in a modified example, the opening 8510 of the blow flow passage 851 and the opening 8520 of the vacuum flow passage 852 may be radially opposed, and the opening 8530 of the paired inert gas flow passage 853 may similarly be radially opposed, or the opening 8510 of the blow flow passage 851 and the opening 8520 of the vacuum flow passage 852 may be circumferentially opposed, and the opening 8530 of the paired inert gas flow passage 853 may similarly be circumferentially opposed.

[0097] In addition, according to this embodiment, the opening 8510 of the blow passage 851 and the opening 8520 of the vacuum passage 852 face each other in the radial direction, while the opening 8530 of the paired inert gas passage 853 faces each other in the circumferential direction, and the openings 8510 and 8520 are offset in the vertical direction with respect to the opening 8530. This makes it easy to form the supply path of the air for removing spatters and the supply path of the inert gas in a manner that is unlikely to interfere with each other and at desired positions suited to their respective purposes. For example, the air for removing spatters can be supplied so as to pass through approximately the center of the welding target portion 90 as viewed in the axial direction, and the inert gas can be supplied so as to stagnate at approximately the center of the welding target portion 90.

[0098] In this embodiment, the opening 8510 of the blow flow passage 851 and the opening 8520 of the vacuum flow passage 852 face each other in the radial direction, while the opening 8530 of the paired inert gas flow passage 853 faces each other in the circumferential direction, but the opposite may be true. That is, the opening 8510 of the blow flow passage 851 and the opening 8520 of the vacuum flow passage 852 face each other in the circumferential direction, while the opening 8530 of the paired inert gas flow passage 853 faces each other in the radial direction. However, in this case, it becomes necessary to form the paired inert gas flow passages 853 in each of the jig member 71 on the radial inner side and the jig member 72 on the radial outer side, which may cause a disadvantage that the configuration (for example, the configuration of the piping, etc.) is likely to become complicated.

[0099] Next, as part of the method for manufacturing the stator 21, a method for manufacturing the stator 21 using the manufacturing apparatus 7 will be described with reference to FIG. 13 and subsequent figures.

[0100] FIG. 13 is a flow chart showing a flow of the manufacturing method of the stator 21 by the manufacturing apparatus 7 (hereinafter, also referred to as "this manufacturing method"). FIG. 14 to FIG. 17 are explanatory diagrams of specific steps in this manufacturing method, FIG. 14 and FIG. 15 are diagrams showing a state in which air and inert gas for removing sputters are supplied to the pair of coil pieces 52, which is the workpiece, from two directions, and FIG. 16 and FIG. 17 are diagrams showing a state in which laser welding is performed in a state in which air and inert gas for removing sputters are supplied to the pair of coil pieces 52 from two directions. In FIG. 14 to FIG. 17, only a part related to the manufacturing apparatus 7 is shown typically, and the flow of gas is shown typically by arrows R130 and R132. In FIG. 16 and FIG. 17, the laser beam 110 is also shown typically.

[0101] First, this manufacturing method includes a clamping step (step S1300) of forming a clamped state in which the pair of coil pieces 52 are restrained using a jig 70. That is, in the clamping step (step S1300), the radially inner jig member 71 and jig member 73 are positioned together with the pair of coil pieces 52 in a predetermined positional relationship for clamping relative to the radially outer jig member 72 to form the clamped state. Note that, in the clamped state, as described above, the tip ends 40 of the pair of coil pieces 52 are maintained in contact with each other, and a hollow portion 500 is formed that connects the tip ends 40 in the contacted state to the outside.

[0102] Next, the present manufacturing method includes a gas supplying step (step S1302) of supplying a gas to cavity 500. In the present manufacturing method, the gas supplying step (step S1302) includes a first gas supplying step (step S1302A) and a second gas supplying step (step S1302B).

[0103] Specifically, in this manufacturing method, as a first gas supplying step (step S1302A), a state is created in which air for removing sputters is supplied to cavity 500 using first gas supplying means 81. Also, in this manufacturing method, as a second gas supplying step (step S1302B), a state is created in which an inert gas is supplied to cavity 500 using second gas supplying means 82. First gas supplying means 81 and second gas supplying means 82 are as described above.

[0104] It should be noted that the first gas supply process (step S1302A) and the second gas supply process (step S1302B) may be started either first or simultaneously.

[0105] In this manner, when the gas supply process (step S1302) is executed, as shown in Figures 14 and 15, a state in which air is supplied to the hollow portion 500 (see arrow R130) and a state in which an inert gas is supplied to the hollow portion 500 (see arrow R132) are simultaneously achieved.

[0106] Next, this manufacturing method includes a welding step (step S1304) in which laser irradiation means 89 is used to irradiate laser beam 110 onto welding target locations 90 of the pair of coil pieces 52, thereby joining tip portions 40 together by laser welding.

[0107] In this embodiment, the welding process (step S1304) is performed while maintaining a state in which both air and inert gas are supplied to the cavity 500 (see arrows R130 and R132) as shown in Figures 16 and 17. This allows the inert gas from the second gas supply means 82 to function as a shielding gas to improve welding quality, and also allows spatters that may be generated during laser welding to be instantly removed from the cavity 500 as soon as they are generated. In this way, an appropriate spatial environment is formed for the laser irradiation path from the laser irradiation means 89 to the welding target portion 90, thereby effectively improving the welding quality.

[0108] Next, this manufacturing method includes a gas supply stopping step (step S1306) of stopping the supply of gas to cavity 500 when the welding step (step S1304) is completed. The gas supply stopping step (step S1306) includes a first stopping step (step S1306A) of stopping the supply of air by first gas supply means 81, and a second stopping step (step S1306B) of stopping the supply of inert gas by second gas supply means 82.

[0109] It should be noted that the first stopping step (step S1306A) and the second stopping step (step S1306B) may be started either first or at the same time.

[0110] Next, this manufacturing method includes an unclamping step (step S1308) of releasing the clamped state (clamped state by the jig 70) of the pair of coil pieces 52 for which laser welding has been completed. The unclamping step (step S1308) may be achieved by positioning the radially inner jig member 71 and jig member 73 in a predetermined positional relationship for unclamping with respect to the radially outer jig member 72.

[0111] According to this manufacturing method, by creating a state in which both air and inert gas are supplied to cavity 500 (see arrows R130 and R132), an appropriate spatial environment can be created for the laser irradiation path from laser irradiation means 89 to welding target portion 90. Then, the welding process (step S1304) can be performed in such an appropriate spatial environment. That is, the welding process (step S1304) can be performed while maintaining a state in which both air and inert gas are supplied to cavity 500 (see arrows R130 and R132). As a result, the welding quality can be effectively improved.

[0112] For the sake of explanation, this manufacturing method is described with respect to one pair of coil pieces 52, but as described above, it can be expanded to a configuration in which the tip portions 40 of multiple pairs (e.g., 12 pairs) of coil pieces 52 are clamped simultaneously. In a configuration in which the tip portions 40 of multiple pairs of coil pieces 52 are clamped simultaneously, the clamping step (step S1300) and the clamping release step (step S1308) may be performed simultaneously for each of the multiple pairs of coil pieces 52, and each step from the gas supply step (step S1302) to the gas supply stop step (step S1306) may be performed simultaneously or sequentially for each of the multiple pairs of coil pieces 52. This makes it possible to efficiently shorten the lead time related to this manufacturing method compared to the case in which various steps are performed for each pair.

[0113] Although each embodiment has been described above in detail, it is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the claims. It is also possible to combine all or a plurality of the components of the above-mentioned embodiments. Furthermore, among the effects of each embodiment, the effects related to the dependent claims are additional effects that are distinguished from the generic concept (independent claim).

[0114] For example, the above-described embodiment relates to joining the tip ends 40 of the coil pieces 52, but it is also applicable to joining the tip ends 40 of the coil pieces 52 to the end of a bus bar (not shown). In this case, the tip ends 40 of the coil pieces 52 joined to the end of the bus bar may be the tip ends of the transition parts that form the power lines or neutral points.

[0115] For example, FIG. 18 shows a perspective view of another applicable welding target portion. In FIG. 18, the same reference numerals are used for components that may be the same as those in the above-mentioned embodiment. In the example shown in FIG. 18, ends 680, 681 of a bus bar held by a terminal block 670 and a tip portion 40A of a coil piece 52A related to a stator coil 24A are joined to each other. In this case, a part of the bus bar held by the terminal block 670 is electrically connected to a three-phase external terminal 671 in the terminal block 670. Laser welding using the jig 70 according to this embodiment may also be applied to the joint between the ends 680, 681 of such a bus bar and the tip portion 40A of the coil piece 52A. In this case, for example, as shown in the axial cross section of FIG. 19, jig members 71A, 72A forming a hook-shaped jig 70A may realize the same function as the jig members 71 and 72 described above. In this case, the jig members 71A and 72A may form a hollow portion 500A on the upper side (Z1 side) of the contact surface 401A between the tip portions 40A. Also, in this case, the jig members 71A and 72A may form a blow flow passage 851A, a vacuum flow passage 852A, and an inert gas flow passage 853A having functions similar to the blow flow passage 851, the vacuum flow passage 852, and the inert gas flow passage 853 of the jig 70 described above, as shown in FIG.

[0116] In the above embodiment, the first gas supply means 81 uses both the positive pressure source 811 and the negative pressure source 812, but only one of the positive pressure source 811 and the negative pressure source 812 may be used. Even in this case, spatters that may be generated during laser welding can be effectively removed from the cavity 500. For example, when only the positive pressure source 811 is used, the vacuum flow path 852 may function as a flow path that collects spatters and the like together with the air injected from the blow flow path 851. When only the negative pressure source 812 is used, the blow flow path 851 may function as a flow path that forms a flow of air from the outside toward the cavity 500 due to the negative pressure from the negative pressure source 812. [Explanation of symbols]

[0117] REFERENCE SIGNS LIST 1 motor (rotating electric machine), 12 rotating shaft (central shaft), 21 stator, 40 tip portion, 52 coil piece (conductor piece), 500 hollow portion, 110 laser beam, 70 jig, 71, 71A jig member (first jig member), 72, 72A jig member (second jig member), 80 gas supply means, 81 first gas supply means, 82 second gas supply supplying means, 811... positive pressure source (pressure generating source), 812... negative pressure source (pressure generating source), 820... inert gas source, 851... blow flow path (first flow path), 8510... opening (first opening), 852... vacuum flow path (first flow path), 8520... opening (first opening), 853... inert gas flow path (second flow path), 8530... opening (second opening), 89... laser irradiation means

Claims

1. a jig for forming a state in which tip portions of one conductor piece and another conductor piece for forming a stator of a rotating electric machine are brought into contact with each other, and for forming a cylindrical cavity portion that connects the tip portions in the contacted state to the outside; a laser irradiation means for irradiating a laser beam from outside through the cavity toward the tip portion in the abutting state; a gas supply means for supplying a gas to the cavity; The gas supply means includes a first gas supply means for supplying air into the cavity in a manner that forms an air flow within the cavity in a direction that intersects with the laser irradiation direction by the laser irradiation means.

2. 2. The manufacturing apparatus for a stator for a rotating electric machine according to claim 1, wherein said gas supplying means further includes a second gas supplying means for supplying an inert gas to said cavity portion.

3. 3. The manufacturing apparatus for a stator for a rotating electric machine according to claim 2, wherein the first gas supply means supplies air into the cavity by generating at least one of a positive pressure and a negative pressure that forcibly discharges air in the cavity to the outside.

4. The first gas supply means is A pressure generating source including at least one of a positive pressure source and a negative pressure source; a first flow path having one end communicating with the pressure generating source and the other end opening into the cavity through a first opening; The second gas supply means is a source of inert gas; one or more second flow paths, one end of which communicates with the inert gas source and the other end of which opens into the cavity through a second opening; 4. The manufacturing apparatus for a stator for a rotating electric machine according to claim 2, wherein the second opening is located farther from the laser irradiation means than the first opening in a direction of laser irradiation by the laser irradiation means.

5. the first flow path includes a positive pressure side flow path portion, one end of which is in communication with the positive pressure source, and a negative pressure side flow path portion, one end of which is in communication with the negative pressure source, The first opening is formed at the other end of the positive pressure side flow passage portion and the other end of the negative pressure side flow passage portion, 5. The manufacturing apparatus for a stator for a rotating electric machine according to claim 4, wherein the first opening on the positive pressure side and the first opening on the negative pressure side face each other across the cavity in a direction intersecting a laser irradiation direction by the laser irradiation means.

6. 6. The manufacturing apparatus for a stator for a rotating electric machine according to claim 5, wherein the positive pressure side flow passage portion extends linearly in a direction approximately perpendicular to the laser irradiation direction by the laser irradiation means in a section leading to the first opening on the positive pressure side.

7. The manufacturing apparatus for a stator for a rotating electric machine according to claim 5 , wherein the first flow passage and the one or more second flow passages are formed in the jig.

8. The jig includes a first jig member on a radially inner side close to a central axis of the stator and a second jig member on a radially outer side, The positive pressure side flow passage portion is formed in the first jig member, The manufacturing apparatus for a stator for a rotating electric machine according to claim 7 , wherein the negative pressure side flow passage portion is formed in the second jig member.

9. 9. The manufacturing apparatus for a stator for a rotating electric machine according to claim 8, wherein the one or more second flow passages are formed in only one of the first jig member and the second jig member.

10. The manufacturing apparatus for a stator for a rotating electric machine according to any one of claims 4 to 9, wherein the supply direction of the inert gas from the second opening intersects with the air flow direction formed by the first gas supply means when viewed in the laser irradiation direction by the laser irradiation means.

11. The manufacturing apparatus for a stator for a rotating electric machine according to claim 10 , wherein the one or more second flow paths are inclined in such a manner that the closer the one or more second flow paths are to the second opening, the farther the one or more second flow paths are from the laser irradiation means in the laser irradiation direction by the laser irradiation means.

12. The manufacturing apparatus for a stator for a rotating electric machine according to any one of claims 4 to 11, wherein the second gas supply means supplies the inert gas from two or more of the second flow paths opposing each other across the hollow portion toward the tip portion in abutting state.

13. The manufacturing device for a stator for a rotating electric machine according to any one of claims 1 to 12, wherein the jig functions simultaneously for multiple pairs of the conductor pieces in a manner that forms a separate cavity for each of the multiple pairs of the conductor pieces.

14. a clamping process in which a jig is used to bring a tip end portion of one conductor piece and a tip end of another conductor piece for forming a stator of a rotating electric machine into contact with each other, and a cylindrical cavity is formed to connect the tip ends in the contacted state to the outside; a gas supplying step of supplying a gas to the cavity portion after the clamping step; a welding step that is performed after the clamping step in a state in which the gas is being supplied by the gas supplying step, and that joins the tip portions together by laser welding by irradiating a laser beam from outside through the hollow portion, The gas supplying step includes supplying air into the cavity in a manner that forms an air flow in the cavity in a direction that intersects with the irradiation direction of the laser beam in the welding step.

15. The method for manufacturing a stator for a rotating electric machine according to claim 14, wherein the gas supplying step further includes supplying an inert gas.

16. the gas supplying step includes supplying air through a first flow path having a first opening that opens into the hollow portion, while supplying the inert gas toward the tip portion in a contacting state through a second flow path having a second opening that opens into the hollow portion; The method for manufacturing a stator for a rotating electric machine according to claim 15 , wherein the second opening is closer to the tip portion in a contacted state than the first opening in a laser irradiation direction.

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