Stator manufacturing method for rotating electrical machines

Abstract

A method for manufacturing a stator for a rotating electric machine is disclosed, comprising: a first configuration step, in which a workpiece for a stator is configured at a first station (ST1); a first welding step, in which a first portion of a stator coil in a workpiece is welded in ST1; a second configuration step, in which another workpiece for a stator is configured at a second station (ST2); and a second welding step, in which a second portion of a stator coil in the other workpiece is welded in ST2. The first welding step includes a first irradiation step in which a welding laser beam (110) is irradiated onto the first portion, and the second welding step includes a second irradiation step in which a welding laser beam is irradiated onto the second portion. The first irradiation step and the second irradiation step have a time difference, and the laser beams used in the first irradiation step and the second irradiation step are generated based on the same oscillator (71, 71A).

Description

Technical Field

[0001] This disclosure relates to a method for manufacturing a stator for a rotating electrical machine. Background Technology

[0002] A known method for manufacturing a stator involves bringing the front ends of one coil piece for forming a stator of a rotating electric motor abutting each other, and irradiating the welding target area at the abutting front ends with a laser beam moving in a ring-shaped manner.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2018-20340

[0004] However, the existing technologies described above are insufficient for achieving efficient stator manufacturing methods. In particular, in the case of stators for rotating motors where the stator coils are formed from multiple coil segments, there are many welding points, requiring efficient manufacturing methods. Summary of the Invention

[0005] Therefore, the purpose of this disclosure is to provide an efficient method for manufacturing stators for rotating electric machines.

[0006] According to one aspect of this disclosure, a method for manufacturing a stator for a rotating electric machine is provided, wherein the stator coil is formed from a plurality of coil plates in the form of segmented coils, comprising:

[0007] The first configuration process involves configuring a workpiece for the stator at the first workstation.

[0008] In the first welding process, at the first station mentioned above, the welding of the first part of the stator coil in the workpiece is completed.

[0009] The second configuration process involves configuring another workpiece for the stator at the second station; and

[0010] In the second welding process, at the second station mentioned above, the welding of the second part of the stator coil in the other workpiece is completed.

[0011] The aforementioned first welding process includes a first irradiation process that irradiates the coil sheet of the welding object in the aforementioned first part with a welding laser beam.

[0012] The second welding process described above includes a second irradiation process in which a welding laser beam is irradiated onto the coil sheet of the welding object in the second part described above.

[0013] The first irradiation step and the second irradiation step have a time difference, and the laser beams used in the first irradiation step and the second irradiation step are generated based on the same oscillator.

[0014] According to this disclosure, an efficient method for manufacturing stators for rotating electric machines can be provided. Attached Figure Description

[0015] Figure 1 This is a cross-sectional view schematically illustrating the cross-sectional structure of a motor according to one embodiment.

[0016] Figure 2 This is a top view of the stator core in its individual state.

[0017] Figure 3 It is a schematic diagram showing a pair of coil plates assembled on a stator core.

[0018] Figure 4 It is a three-dimensional view of the area around the end of the stator coil.

[0019] Figure 5 This is a three-dimensional view showing a portion of the coil sheet of the same phase that has been extracted.

[0020] Figure 6 This is a simplified front view of a coil sheet.

[0021] Figure 7 This is a diagram showing the front end of the coil pieces that are joined together and their vicinity.

[0022] Figure 8 It is along the welded object area. Figure 7 A sectional view of line AA.

[0023] Figure 9 It is a flowchart that schematically illustrates the manufacturing process of the stator.

[0024] Figure 10 It indicates the joining process ( Figure 9 The flowchart of each process in step S22).

[0025] Figure 11 This is an explanatory diagram of multiple workstations.

[0026] Figure 12 It is an illustrative diagram illustrating the flow of workpieces between multiple workstations.

[0027] Figure 13A It is a schematic diagram showing the configuration of the fixture when viewed from above the workpiece.

[0028] Figure 13B yes Figure 13A Enlarged view of part Q1.

[0029] Figure 14 This is a simplified diagram showing the relationship between the laser head and the workpiece.

[0030] Figure 15A This is an explanatory diagram of a scanned area.

[0031] Figure 15B This is an explanatory diagram of another scanned area.

[0032] Figure 15C This is an explanatory diagram of another scanned area.

[0033] Figure 16A This is a simplified diagram illustrating an example of a head-moving type laser irradiation device.

[0034] Figure 16B This is a simplified diagram illustrating another example of a head-switching type laser irradiation device.

[0035] Figure 17A This is a simplified diagram of the overall structure when a head-moving laser irradiation device is used.

[0036] Figure 17B This is a simplified diagram of the overall structure when a head-switching type laser irradiation device is used.

[0037] Figure 18 This is an illustrative diagram illustrating an example of the collaborative method between the first and second welding processes.

[0038] Figure 19 This is an illustration of an example of a collaborative method that can be achieved using a 6-turn retaining fixture.

[0039] Figure 20A yes Figure 19 The diagram illustrates the welding waiting time in the example shown.

[0040] Figure 20B This is an explanatory diagram of the welding waiting time in the case of the first variation. Detailed Implementation

[0041] Hereinafter, various embodiments will be described in detail with reference to the accompanying drawings. Furthermore, in this specification, the word "specify" is used to mean "pre-specified".

[0042] Figure 1 This is a cross-sectional view schematically showing the cross-sectional structure of a motor 1 (an example of a rotary electric machine) according to an embodiment.

[0043] Figure 1 The diagram shows the rotating shaft 12 of the motor 1. In the following description, axial direction refers to the direction in which the rotating shaft (center of rotation) 12 of the motor 1 extends, and radial direction refers to the radial direction centered on the rotating shaft 12. Therefore, radial outer side refers to the side away from the rotating shaft 12, and radial inner side refers to the side facing the rotating shaft 12. In addition, circumferential direction corresponds to the direction of rotation about the rotating shaft 12.

[0044] Motor 1 can be, for example, a vehicle drive motor used in hybrid vehicles or electric vehicles. However, motor 1 can also be used for any other purpose.

[0045] Motor 1 is an internal rotor type, with stator 21 arranged radially around rotor 30. The radially outer side of stator 21 is fixed to motor housing 10.

[0046] 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 radially outside the rotor shaft 34 and rotates integrally with the rotor shaft 34. The rotor shaft 34 is supported by the motor housing 10 via bearings 14a and 14b to enable rotation. Furthermore, the rotor shaft 34 divides the rotation axis 12 of the motor 1.

[0047] The rotor core 32 is formed, for example, from a stack of steel plates containing a ring-shaped strong magnetic material. Permanent magnets 321 are inserted inside the rotor core 32. The number and arrangement of the permanent magnets 321 are arbitrary. In a modified example, the rotor core 32 may also be formed from a compacted powder body formed by compressing magnetic powder.

[0048] End plates 35A and 35B are installed on both sides of the rotor core 32 along the axial direction. In addition to supporting the rotor core 32, the end plates 35A and 35B can also adjust the imbalance of the rotor 30 (by cutting or the like to eliminate the imbalance).

[0049] like Figure 1 As shown, the rotor shaft 34 has a hollow portion 34A. The hollow portion 34A extends along the entire axial length of the rotor shaft 34. The hollow portion 34A can also function as an oil passage. For example, in the hollow portion 34A, such as Figure 1 As indicated by arrow R1, oil is supplied from one end of the axial direction and 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 along the radially inner surface of the rotor shaft 34 can also be sprayed radially outward through oil holes 341 and 342 formed at both ends of the rotor shaft 34 (arrows R5 and R6) to cool the coil tail ends 220A and 220B.

[0050] In addition, Figure 1 The diagram shows a motor 1 with a specific construction, but the construction of motor 1 is arbitrary as long as it has stator coils 24 joined by welding (described later). Therefore, for example, the rotor shaft 34 may or may not have a hollow portion 34A, or it may have a hollow portion with an inner diameter significantly smaller than that of the hollow portion 34A. Furthermore, in... Figure 1The specific cooling method is disclosed, but the cooling method of motor 1 is arbitrary. Therefore, for example, an oil inlet pipe inserted into the hollow part 34A may be provided, or oil may be dripped from the oil passage inside the motor housing 10 from the radial outside toward the coil tail ends 220A and 220B.

[0051] In addition, Figure 1 In this case, the rotor 30 is arranged inside the stator 21, which is an inner rotor type motor 1, but it can also be applied to other types of motors. For example, it can also be applied to an outer rotor type motor in which the rotor 30 is arranged concentrically on the outside of the stator 21, or a dual rotor type motor in which the rotor 30 is arranged on both the outside and inside of the stator 21.

[0052] Next, refer to Figure 2 The accompanying drawings and the figures thereafter provide a detailed description of the structure related to the stator 21.

[0053] Figure 2 This is a top view of the stator core 22 in its single-item state. Figure 3 This is a schematic diagram showing a pair of coil plates 52 assembled on the stator core 22. Figure 3 In the image, with the radial inner side of the stator core 22 unfolded, the relationship between a pair of coil plates 52 and the slot 220 is shown. Additionally, in... Figure 3 In the diagram, the stator core 22 is represented by a dashed line, and a portion of the slot 220 is omitted from the illustration. Figure 4 This is a 3D view of the area around the coil tail end 220A of stator 21. Figure 5 This is a perspective view showing a portion of the in-phase coil piece 52.

[0054] The stator 21 includes the stator core 22 and the stator coil 24.

[0055] The stator core 22 is, for example, composed of stacked steel plates of a ring-shaped strong magnetic material. However, in a modified example, the stator core 22 may also be formed from a compacted powder body formed by compressing magnetic powder. Furthermore, the stator core 22 may be formed from a segmented core divided in the circumferential direction, or it may be an undivided core. Multiple slots 220 for winding the stator coil 24 are formed on the radially inner side of the stator core 22. Specifically, as... Figure 2 As shown, the stator core 22 includes an annular back yoke 22A and a plurality of teeth 22B extending radially inward from the back yoke 22A, with grooves 220 formed between the plurality of teeth 22B in the circumferential direction. The number of grooves 220 is arbitrary, but in this embodiment, 48 are provided as an example.

[0056] The stator coil 24 includes a U-phase coil, a V-phase coil, and a W-phase coil (hereinafter, without distinguishing between U, V, and W, they are referred to as "phase coils"). The base 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 coils to form the neutral point of the motor 1. That is, the stator coil 24 is star-connected. However, the connection method of the stator coil 24 can be appropriately changed according to the required motor characteristics, etc. For example, the stator coil 24 can also be delta-connected instead of star-connected. In addition, the stator coil 24 includes a neutral point portion and a power line portion, but hereafter, the portion other than these will sometimes be referred to as the "general portion".

[0057] Each phase coil is constructed by joining multiple coil pieces 52 together. Figure 6 This is a simplified front view of a coil sheet 52. The coil sheet 52 is in the form of a segmented coil obtained by dividing the phase coil into easily assembled units (e.g., units inserted into two slots 220). The coil sheet 52 is formed by covering a linear conductor (flat wire) 60 with an insulating film 62, which has a generally rectangular cross-section. In this embodiment, the linear conductor 60 is formed of copper as an example. However, in variations, the linear conductor 60 may also be formed of other conductor materials such as iron.

[0058] Before being assembled into the stator core 22, the coil sheet 52 can be shaped into a generally U-shape having a pair of straight sections 50 and a connecting section 54 connecting the pair of straight sections 50. When assembling the coil sheet 52 into the stator core 22, the pair of straight sections 50 are respectively inserted into slots 220 (see reference). Figure 3 Therefore, as Figure 3 As shown, the connecting portion 54 extends circumferentially across multiple teeth 22B (and multiple slots 220 accompanying the teeth 22B) on the other axial end side of the stator core 22. The number of slots 220 spanned by the connecting portion 54 is arbitrary, but... Figure 3 There are three in the middle. Additionally, after the straight section 50 is inserted into the slot 220, as in... Figure 6 As shown by the double-dotted line, it bends circumferentially in the middle. Thus, the straight section 50 becomes a foot 56 extending axially in the slot 220 and an overlapping section 58 extending circumferentially at one end of the axial direction of the stator core 22.

[0059] In addition, Figure 6 In this configuration, the pair of straight sections 50 bend in a direction of separation from each other, but this is not a limitation. For example, the pair of straight sections 50 may also bend in a direction of approaching each other. In addition, the stator coil 24 may sometimes also have a neutral point coil piece, etc., for connecting the ends of the phase coils of the three phases to form a neutral point with each other. The shape of the front end portion 40 described later may also be applied to the aforementioned connecting coil piece and neutral point coil piece.

[0060] Multiple Figure 6 The feet 56 of the coil laminations 52 shown are arranged radially and inserted into a slot 220. Therefore, on one axial end side of the stator core 22, a plurality of circumferentially extending overlapping portions 58 are arranged radially. Figure 3 and Figure 5 As shown, the overlap 58 of a coil piece 52 extending from one slot 220 and extending circumferentially to a first side (e.g., clockwise) engages with the overlap 58 of another coil piece 52 extending from another slot 220 and extending circumferentially to a second side (e.g., counterclockwise).

[0061] In this embodiment, as an example, six coil pieces 52 are assembled in a slot 220. Hereinafter, starting from the outermost coil piece 52 in the radial direction, they are referred to as the first turn, the second turn, and the third turn. In this case, the coil pieces 52 of the first turn and the coil pieces 52 of the second turn are joined together at their front ends 40 by a joining process described later, the coil pieces 52 of the third turn and the coil pieces 52 of the fourth turn are joined together at their front ends 40 by a joining process described later, and the coil pieces 52 of the fifth turn and the coil pieces 52 of the sixth turn are joined together at their front ends 40 by a joining process described later.

[0062] Here, the coil piece 52 is covered with an insulating film 62 as described above, but only the front end 40 has this insulating film 62 removed. This is to ensure electrical connection with other coil pieces 52 through the front end 40. Additionally, as... Figure 5 and Figure 6 As shown, the final axially outer end face 42 of the front end portion 40 of the coil piece 52, that is, the end face of the coil piece 52 in the width direction, is set as an arc surface that protrudes axially outward.

[0063] Figure 7 This is a diagram showing the front end 40 of the interlocking coil pieces 52 and its vicinity. Furthermore, in... Figure 7 The diagram schematically represents the circumferential range D1 of the welding object part 90. Figure 8 It is along the 90° of the welding object. Figure 7 A sectional view of line AA.

[0064] When joining the front ends 40 of the coil sheet 52, the two front ends 40 that are joined together can be joined by overlapping them in their thickness direction so that the central axis O of their respective arc surfaces (axially outer end faces 42) is aligned. By overlapping them so that the central axis is aligned, the axially outer lines of the two front ends 40 that are joined together can be aligned and properly coincided even when the buckling angle α is relatively large or relatively small.

[0065] Here, in this embodiment, welding is used as the joining method when joining the front ends 40 of the coil pieces 52. Furthermore, in this embodiment, instead of arc welding, such as TIG welding, laser welding, which uses a laser beam source as a heat source, is employed as the welding method. By using laser welding instead of TIG welding, the axial length of the coil tail ends 220A and 220B can be reduced. That is, in the case of TIG welding, the front ends of the abutting coil pieces need to bend outwards axially and extend axially, while in the case of laser welding, this bending is not required. Figure 7 As shown, welding can be achieved with the front ends 40 of the abutting coil pieces 52 extending circumferentially to each other. Therefore, compared with the case where the front ends 40 of the abutting coil pieces 52 are bent outward axially and extended axially, the axial length of the coil tail ends 220A and 220B can be reduced.

[0066] In laser welding, such as Figure 5 As schematically shown, a welding laser beam 110 is irradiated onto the welding target portion 90 of the two abutting front ends 40. Furthermore, the irradiation direction (propagation direction) of the laser beam 110 is approximately parallel to the axial direction, moving from the outer axial direction towards the outer axial end faces 42 of the two abutting front ends 40. In the case of laser welding, localized heating is possible, thus heating only the front ends 40 and their vicinity, effectively reducing damage (carbonization) to the insulating film 62. As a result, multiple coil pieces 52 can be electrically connected while maintaining appropriate insulation properties.

[0067] like Figure 7 As shown, the circumferential range D1 of the welding object 90 is the entire circumferential range D0 of the outermost end faces 42 of the two coil pieces 52 in the abutting portion between each other, excluding the two ends. Due to the protruding arcuate surface of the outermost end faces 42 at both ends, it is difficult to ensure sufficient welding depth (see reference). Figure 7 The circumferential range D1 of the welding object 90 can be adapted to ensure the required joint area, required welding strength, etc. between the coil pieces 52.

[0068] like Figure 8 As shown, the radial range D2 of the welding target area 90 is centered on the abutment surface 401 of the front ends 40 of the two coil plates 52. The radial range D2 of the welding target area 90 can correspond to the diameter (beam diameter) of the laser beam 110. That is, the laser beam 110 irradiates in a manner that the irradiation position does not actually change radially but changes linearly along the circumference.

[0069] Next, refer to Figure 9 The manufacturing process of stator 21 is described in detail. Figure 9This is a flowchart schematically illustrating the manufacturing process of stator 21.

[0070] The manufacturing method of stator 21 includes the steps of first preparing stator core 22 and preparing straight coil pieces 52 (coil pieces 52 before forming) for forming stator coil 24 (S12).

[0071] Next, the manufacturing method of the stator 21 includes a step (S14) of removing the insulating film 62 from the front end 40 (start and end) of the coil sheet 52. The method for removing the insulating film 62 is arbitrary, but for example, it can be removed mechanically using a cutting tool, or chemically using etching or the like. Alternatively, a laser can be used to thermally remove the insulating film 62.

[0072] In addition, in order to join the coil pieces 52 together, it is only necessary to remove the insulating film 62 of the facets that are actually joined at least in the front end 40, or the insulating film 62 of the other faces (the back or the other side of the surface, and the side faces) can be left.

[0073] Next, the manufacturing method of the stator 21 includes a forming step (S16) after the removal process, in which the straight coil sheet 52 is bent and shaped using a mold or the like. For example, the coil sheet 52 is shaped into... Figure 6 It has a roughly U-shaped structure as shown, with a pair of straight sections 50 and a connecting section 54 connecting the pair of straight sections 50. Furthermore, the order of steps S16 and S14 can be interchanged.

[0074] Next, the manufacturing method of stator 21 includes an installation process (S18) after the forming process, in which coil pieces 52 are inserted into slots 220 of stator core 22. The insertion process is completed when all coil pieces 52 have been inserted.

[0075] Next, the manufacturing method of the stator 21 includes a deformation process (S20) after the insertion process, in which a special jig is used to lay down the portion protruding from each slot 220 in the straight section 50 in the circumferential direction. As a result, the straight section 50 becomes a foot 56 extending axially in the slot 220 and an overlapping portion 58 extending circumferentially at one end in the axial direction.

[0076] Next, the manufacturing method of the stator 21 includes a joining step (S22) after the deformation process, in which the front end portion 40 of the overlap portion 58 of one coil piece 52 extending circumferentially to a first side (e.g., clockwise) is joined to the front end portion 40 of the overlap portion 58 of another coil piece 52 extending circumferentially to a second side (e.g., counterclockwise). In this embodiment, as described above, the two front ends 40 are joined by welding. The details of the joining step (a laser welding-based joining step) are as described above. Welding is performed for every two front ends 40, and the joining step ends when all two front ends 40 of the group have been welded.

[0077] Next, the manufacturing method of stator 21 includes a finishing process (S24) after the joining process. The finishing process may include, for example, a process of insulating the coil ends 220A and 220B formed by assembling the coil pieces 52 as described above. In addition, the insulation treatment may be a process of molding resin to seal the coil ends 220A and 220B as a whole, or a process of applying varnish or the like.

[0078] Next, refer to Figure 10 The accompanying drawings and the drawings thereafter describe the aforementioned joining process. Figure 9 Step S22) is explained in detail.

[0079] Figure 10 It indicates the joining process ( Figure 9 The flowchart of each process in step S22). Figure 11 yes Figure 10 The diagram is an explanation diagram of multiple workstations ST1 to ST4. Figure 12 yes Figure 10 The diagram illustrates the workflow between multiple workstations ST1 to ST4. Figure 12 The diagram shows the workpieces processed at workstations ST1 to ST4 in each state, starting from state 1 and transitioning to state 2, state 3, etc.

[0080] In this embodiment, the joining process is implemented using four stations ST1 to ST4 as an example. Furthermore, the number of stations can be arbitrary as long as there are two or more. Workpieces are moved into stations ST1 to ST4 respectively. Here, the workpieces are specifically designated for sub-assembly; more specifically, they are workpieces used as… Figure 9 The workpiece being processed in step S22.

[0081] Reference Figure 10 First, in step S220, workpieces are moved to each station ST1 to ST4. Furthermore, the workpieces moved to each station ST1 to ST4 are individually different workpieces. For example, in... Figure 12In the example shown, state 4 following state 3 is the state where workpiece k4 is moved in at station ST1, workpiece k3 is moved in at station ST2, workpiece k2 is moved in at station ST3, and workpiece k1 is moved in at station ST4. Furthermore, the timing of the workpieces moved in at stations ST1 through ST4 is preferably simultaneous, but a significant time difference is also possible.

[0082] In the next step S222, the prescribed process assigned to each of stations ST1 to ST4 is performed. In this embodiment, as an example, a first welding process is assigned to station ST1, which completes the welding of the first portion of the stator coil 24 in the workpiece. A second welding process is assigned to station ST2, which completes the welding of the second portion of the stator coil 24 in the workpiece. A third welding process is assigned to station ST3, which completes the welding of the third portion of the stator coil 24 in the workpiece. A fourth welding process is assigned to station ST4, which completes the welding of the fourth portion of the stator coil 24 in the workpiece.

[0083] The first to fourth parts of the stator coil 24 are, for example, mutually distinct parts, and the method of dividing the first to fourth parts is arbitrary. In this embodiment, as an example, the first part of the stator coil 24 is the coil piece 52 of the first and second turns, the second part of the stator coil 24 is the coil piece 52 of the third and fourth turns, the third part of the stator coil 24 is the coil piece 52 of the fifth and sixth turns, and the fourth part of the stator coil 24 is the coil piece 52 of the power line and neutral line of the stator coil 24. Furthermore, in other embodiments, the first part of the stator coil 24 may be the coil piece 52 of the first to sixth turns inserted into the slot 220 of the first group, the second part of the stator coil 24 may be the coil piece 52 of the first to sixth turns inserted into the slot 220 of the second group (different from the first group), the third part of the stator coil 24 may be the coil piece 52 of the first to sixth turns inserted into the slot 220 of the third group (different from the first and second groups), and the fourth part of the stator coil 24 may be the coil piece 52 of the power line and neutral line of the stator coil 24.

[0084] In the next step S224, the workpieces that have completed their assigned welding processes at each station ST1 to ST4 are moved to the next process. For example, in Figure 12In the example shown, during the transition from state 4 to state 5, workpiece k4, which has completed the welding in the first welding process, is moved out from station ST1; workpiece k3, which has completed the welding in the second welding process, is moved out from station ST2; workpiece k2, which has completed the welding in the third welding process, is moved out from station ST3; and workpiece k1, which has completed the welding in the fourth welding process, is moved out from station ST4. In this case, a new workpiece k5 is moved into station ST1; workpiece k4, which has completed the welding in the first welding process, is moved into station ST2; workpiece k3, which has completed the welding in the second welding process, is moved into station ST3; and workpiece k2, which has completed the welding in the third welding process, is moved into station ST4.

[0085] Furthermore, step S224 and the following step S222 are preferably executed simultaneously, but there can also be a significant time difference.

[0086] Thus, according to Figures 10-12 In the example shown, each workpiece utilizes multiple stations ST1 to ST4 to achieve a joining process. Figure 9 Welding in step S22).

[0087] Next, each welding step from the first welding step to the fourth welding step will be described in detail. Furthermore, hereinafter, when referring to any welding step that is not limited to a specific welding step from the first to the fourth welding steps, it will be simply referred to as a "welding step".

[0088] Figure 13A and Figure 13B This is an explanatory diagram of fixture 80 that can be used in the first welding process. Figure 13A This is a diagram that schematically shows the configuration of fixture 80 from a top view of workpiece 1300. Figure 13B yes Figure 13A An enlarged view of part Q1. Figure 13A and Figure 13B In the diagram, for ease of understanding, fixture 80 is marked with a shading instead of a sectional view. Furthermore, Figure 13A The workpiece 1300 shown, for example, can be coupled with... Figure 12 The workpiece k1 to workpiece k5 shown corresponds to any one of them.

[0089] The clamp 80 is held in a state where the front ends 40 of the coil pieces 52 to be welded abut each other. The clamp 80 provided at station ST1 is held in a state where the front ends 40 of the first coil piece 52 and the second coil piece 52 abut each other. The clamp 80 can also function to constrain the front ends 40 of the coil pieces 52 to be welded in the radial, axial and circumferential directions. In addition, the clamp 80 is provided separately at stations ST1 to ST4. Although not shown, the clamp 80 provided at station ST2 is held in a state where the front ends 40 of the third coil piece 52 and the fourth coil piece 52 abut each other, and the clamp 80 provided at station ST3 is also held in the same state.

[0090] In this embodiment, as an example, such as Figure 13A As shown, the clamps 80 are arranged at 30-degree intervals along the circumference, totaling 12. Therefore, since there are 48 groups of coil pieces 52 of the welding object in station ST1 (corresponding to 48 slots 220), one-quarter of them are held simultaneously by 12 clamps 80. Furthermore, the number of clamps 80 relative to the groups of coil pieces 52 of the welding object is arbitrary, but from the viewpoint of maximizing the efficiency of the welding process, it is desirable to have as many as possible. Hereinafter, the action of the clamps 80 holding the coil pieces 52 of the object is also referred to as "locking," and the action of separating the held coil pieces 52 is also referred to as "unlocking."

[0091] Figure 14 This is a simplified diagram showing the relationship between the laser head 72 and the workpiece 1300. Figures 15A-15C This is an explanatory diagram of the scan area 1400A to 1400C. Figures 15A-15C The scanning areas 1400A to 1400C are represented by shaded areas when viewed from above on workpiece 1300. Furthermore, Figure 14 The workpiece 1300 shown, for example, can be coupled with Figure 12 The workpiece k1 to workpiece k5 shown corresponds to any one of them.

[0092] In the first welding process (and the same applies to the second to fourth welding processes), a laser beam of any wavelength can be used, but in this embodiment, instead of an infrared laser, a green laser is used. Furthermore, the concept of a green laser includes not only lasers with a wavelength of 532 nm, i.e., SHG (Second Harmonic Generation) lasers, but also lasers with wavelengths close to 532 nm. Additionally, in variations, lasers with wavelengths below 0.6 μm, which are not considered green lasers, can also be used. The wavelength of the green laser can be obtained, for example, by converting the basic wavelength generated by a YAG laser or a YVO4 laser using an oxide single crystal (e.g., LBO: lithium triborate).

[0093] In the case of green laser, the absorption rate is higher than that of copper, which is the material of the linear conductor 60 of the coil sheet 52, by about 50%. Therefore, according to this embodiment, compared with the case of using infrared laser, the required bonding area between the coil sheets 52 can be ensured with less heat input.

[0094] The laser head 72 is a device capable of directing a laser beam toward an irradiation position. The laser head 72 can cover the welding target area 90 of the stator coil 24 covering the entire circumference of the workpiece 1300 simply by moving (scanning) the irradiation position, and can also be configured concentrically with respect to the central axis of the workpiece 1300 (corresponding to the rotation axis 12 of the motor 1). In this case, the laser head 72 can be fixed during the welding process (step S222) on one workpiece 1300. However, in this embodiment, the laser head 72 is movable because it cannot cover the welding target area 90 of the stator coil 24 covering the entire circumference of the workpiece 1300 simply by moving the irradiation position of the laser beam 110. In this case, the laser head 72 has a reference axis 1304 parallel to the central axis of the workpiece 1300, such as... Figure 14 As shown, the reference axis 1304 is eccentric relative to the central axis of the workpiece 1300. In this case, the laser head 72 rotates about the central axis of the workpiece 1300 (see reference). Figure 14 (arrow R130), thereby covering the welding target area 90 of the stator coil 24 throughout the entire circumference of the workpiece 1300.

[0095] Right now, Figure 15A The scanning area 1400A (an example of the first and third regions) represents the position of the laser head 72 at a certain rotation angle (an example of the first and third positions). Figure 15B This indicates the scan area 1400B (an example of the second and fourth regions) when the device is in a position with another rotation angle (an example of the second and fourth positions). Figure 15C The scanning area 1400C represents the position at another rotation angle. In this embodiment, by being placed in three different positions, the laser head 72 covers the entire group (48 groups) of coil sheets 52 of the object to be welded in the first welding process. Specifically, scanning areas 1400A to 1400C each cover 120 degrees, working together to cover a full 360 degrees. Figures 15A-15C In the diagram, the angular positions covered by the scanned areas 1400A to 1400C, and the angular positions where the fixture 80 functions, are schematically shown as ○P1 to P12. Furthermore, the workpiece 1300 can rotate about the rotation axis 12, and by performing three 7.5-degree rotations, the fixture 80 can hold all groups.

[0096] Next, the relationship (cooperation) between the first and second welding processes will be explained. Furthermore, the same cooperation can be achieved for the third and fourth welding processes, but this will be omitted here.

[0097] Figure 16A This is a simplified diagram illustrating an example of a head-moving type laser irradiation device 70 that can be used in this embodiment. Figure 16A In the diagram, solid and dashed lines schematically represent the paths (optical paths) of the laser beam 110 and the visible light 112, respectively. Additionally, in... Figure 16A In the diagram, two motors, 1600 and 1602, are shown as related structures.

[0098] like Figure 16A As shown, the laser irradiation device 70 includes a laser oscillator 71, a laser head 72, a camera 74, a processing device 76, etc.

[0099] The laser head 72 is, for example, a galvanometer scanning laser head. The laser head 72 includes lenses L1-L3, a semi-reflecting mirror HM, and reflecting mirrors M1 and M2. A laser beam (seed light) is input from the laser oscillator 7 to a pair of laser heads 72. Based on the input laser beam, the laser head 72 generates the aforementioned laser beam 110 (see reference). Figure 5 Specifically, the laser head 72 directs the input laser beam sequentially through lens L1, semi-reflective mirror HM, lens L2, reflectors M1, M2, and lens L3 toward the welding target area 90. Furthermore, the visible light 112 reflected from the welding target area 90 sequentially passes through lens L3, reflector M2, reflector M1, lens L2, and semi-reflective mirror HM of the laser head 72, and further passes through reflector 75 before entering the camera 74. In this way, the camera 74 can acquire an image including the welding target area 90 and its surroundings.

[0100] As described above, camera 74 is capable of acquiring images including the welding object 90 and its surroundings. The images acquired by camera 74 are input to processing device 76.

[0101] The processing device 76 may include a microcomputer, comprising a position determination unit 760, a head position control unit 762, and an illumination position data storage unit 766. Furthermore, the position determination unit 760 and the head position control unit 762 may be implemented by executing one or more programs stored in a storage device such as a ROM (Read Only Memory) using a CPU (Central Processing Unit). The illumination position data storage unit 766 may be implemented using a ROM, or an auxiliary storage device such as a HDD (Hard Disk Drive) or an SSD (Solid State Drive).

[0102] The position determination unit 760 processes the image from the camera 74 to determine the laser irradiation position. In this embodiment, as an example, the position is determined relative to the position of the laser head 72 (refer to...). Figures 15A-15C The nominal value of the corresponding laser irradiation position is stored in the irradiation position data storage unit 766. In this case, the position determination unit 760 processes the image from the camera 74 to correct the nominal value of the laser irradiation position, thereby determining the final laser irradiation position. Hereinafter, the processing of such a position determination unit 760 will also be referred to as "position correction".

[0103] The head position control unit 762 controls the position of the laser head 72 via motors 1600 and 1602. Motor 1600 generates power for the laser head 72 to rotate around the central axis of the workpiece 1300. In addition, motor 1602 generates power for the laser head 72 to move between station ST1 and station ST2 (described later).

[0104] The irradiation position data storage unit 766 stores the position of the laser head 72 as described above (see reference). Figures 15A-15C The data of the nominal value of the corresponding laser irradiation position.

[0105] according to Figure 16A The head-moving type laser irradiation device 70 shown is, for example... Figure 17A As schematically indicated by arrow R1702, by moving the laser head 72 between station ST1 and station ST2, the laser oscillator 71 and laser head 72 can be shared in both the first and second welding processes. That is, the laser oscillator 71 and laser head 72 function in both the first and second welding processes. This allows for a highly efficient structure that covers both stations ST1 and ST2 with a single set of laser oscillators 71 and laser heads 72. Furthermore, in Figure 17A (To be continued) Figure 17B Similarly, arrow R1700 schematically represents the flow of workpiece 1300 through workstations ST1 to ST4.

[0106] Figure 16B This is a simplified diagram illustrating another example of a head-switching type laser irradiation device 70A that can be used in this embodiment. Figure 16B The diagram schematically illustrates the paths (optical paths) of the laser beam 110 and the visible light 112. Additionally, in... Figure 16B In the diagram, two motors, 1600 and 1600A, are shown as part of the relevant structure. Figure 16B In the middle, targeting what can be with Figure 16A For constituent elements that are identical as shown, there are cases where the same reference mark is used but the description is omitted.

[0107] Figure 16B The laser irradiation device 70A shown is relative to Figure 16A The laser irradiation device 70 shown is a head-moving type. The laser oscillator 71 is replaced by a laser oscillator 71A, and the processing device 76 is replaced by a processing device 76A. The second welding process differs in that it includes a further laser head 72A and a further processing device 76A. In this case, the laser head 72A functions only in the first welding process and the second welding process, respectively.

[0108] exist Figure 16B In the example shown, laser head 72 is dedicated to station ST1 and will not move between station ST1 and station ST2. Therefore, in Figure 16B In the example shown, motor 1602 is omitted.

[0109] Laser oscillator 71A is connected to two laser heads 72 and 72A. Laser oscillator 71A can switch between any one of the input laser beams in laser heads 72 and 72A in a time-division manner. That is, laser oscillator 71A has a beam switching function and can switch between any one of the input laser beams in laser heads 72 and 72A.

[0110] Laser head 72A is dedicated to station ST2 and will not move between station ST1 and station ST2. Like the laser head 72 described above, laser head 72A is, for example, a galvanometer scanning type laser head. Laser head 72A receives a laser beam from laser oscillator 71A. Based on the input laser beam, laser head 72A generates the aforementioned laser beam 110 (see reference). Figure 5 Specifically, the laser head 72A directs the input laser beam sequentially through lens L1, half-reflector HM, lens L2, reflectors M1, M2, and lens L3 toward the welding target area 90.

[0111] The processing device 76A, for example, comprises a microcomputer and includes a position determination unit 760, a head position control unit 762A, and an irradiation position data storage unit 766. Furthermore, in Figure 16B The image shows two processing devices 76A for laser head 72 and laser head 72A, but the functions of the two processing devices 76A can also be achieved by a single processing device.

[0112] The head position control unit 762A of the processing device 76A for the laser head 72 controls the position of the laser head 72 via a motor 1600A. The head position control unit 762A of the processing device 76A for the laser head 72A controls the position of the laser head 72A via a motor 1600A. The motor 1600A generates power for the laser head 72A to rotate about the central axis of the workpiece 1300 (see reference). Figure 14 The driving force of ).

[0113] according to Figure 16B The head-switching type laser irradiation device 70A shown is, for example... Figure 17B As illustrated, by switching the laser beam input from the laser oscillator 71A between the laser head 72 at station ST1 and the laser head 72A at station ST2, the laser oscillator 71A can be shared in both the first and second welding processes. That is, the laser oscillator 71A functions in both the first and second welding processes. Thus, a highly efficient structure can be achieved that covers both stations ST1 and ST2 with a single laser oscillator 71A.

[0114] According to this embodiment, by utilizing Figure 16A The head-moving type laser irradiation device 70 shown Figure 16B The head-switching type laser irradiation device 70A shown enables the first welding process at station ST1 to cooperate with the second welding process at station ST2, and achieves an efficient method for manufacturing the stator 21.

[0115] Next, refer to Figure 18 And the accompanying figures, for the use of Figure 16A The head-moving type laser irradiation device 70 shown Figure 16B The method of cooperation between the first welding process at station ST1 and the second welding process at station ST2, which can be achieved by the head-switching type laser irradiation device 70A shown, will be explained below. Unless otherwise specified, the following will describe the method of cooperation using... Figure 16B The example shown is of a head-switching type laser irradiation device 70A, but it can also be used... Figure 16A The head-moving type laser irradiation device 70 shown is illustrated.

[0116] Figure 18 This is an illustrative diagram illustrating an example of the collaborative method between the first welding process at station ST1 and the second welding process at station ST2.

[0117] exist Figure 18 In the diagram, the process number, process content, and irradiation sequence are shown on the left. On the right, the execution periods E1 to E20 for each process number are represented by bars. The execution periods E1 to E20 for each process number are indicated by a time sequence, with time flowing further to the right. The origin "0" of the time axis corresponds to the start time of processing a workpiece 1300. Furthermore, for easier differentiation, [the diagram is missing from the original text]. Figure 18 (To be continued) Figure 19 In the same way, the execution periods E1 to E20, and the execution periods E3, E5, E7, E9, E13, E15, E17 and E19 of the first irradiation process and the second irradiation process are blacked out.

[0118] Operation numbers 1 to 10 refer to the various operations performed at workstation ST1, executed in ascending order of operation number. Similarly, operation numbers 11 to 20 refer to the various operations performed at workstation ST2, executed in ascending order of operation number.

[0119] Specifically, at station ST1, the first configuration step (process number 1) is executed. In the first configuration step, a new workpiece 1300 is moved into station ST1 and a completed workpiece 1300 is moved from station ST1 to station ST2 (refer to E1). In this case, by equalizing the operation time at each station, an efficient method of simultaneously moving workpieces in and out can be achieved.

[0120] If the first configuration process is completed and the new workpiece 1300 is moved in, the first welding process is executed. In the first welding process, a first preparation process and a first irradiation process are performed on every 12 of the 48 welding target locations 90 between the first and second turns. Furthermore, the first preparation process is a preparation process for performing the first irradiation process. That is, firstly, as the first preparation process numbered 2, the coil sheets 52 of the initial 12 welding target locations 90 are locked by the clamp 80 (an example of a first clamp) at station ST1 (see E2). Figure 13A Next, as the first irradiation step (step number 3), welding is performed on the 12 welding target locations 90 of the locked coil sheet 52 (refer to E3). In the first irradiation step, the laser head 72 sequentially changes the scanning area (refer to...). Figures 15A-15C While irradiating 12 welding target areas 90 sequentially with laser beam 110, as the first preparatory step (step number 4), after unlocking, the workpiece 1300 is rotated 7.5 degrees. After rotation, the coil plates 52 (refer to E4) of the next 12 welding target areas 90 are locked by clamp 80. Then, as the first irradiation step (step number 5), welding is performed in the same way (refer to E5). This first preparatory step and first irradiation step (refer to E6-E9) are repeated for every 12 locations. When all 48 welding target areas 90 are welded, the first welding step of the workpiece 1300 is completed by unlocking (refer to E10).

[0121] In workstation ST2, the same process as in workstation ST1 is performed.

[0122] Specifically, at station ST2, the second configuration step (process number 11) is executed first. In this second configuration step, a new workpiece 1300 (from station ST1) is moved into station ST2, and a completed workpiece 1300 is moved from station ST2 to station ST3 (see E11). In this case, by equalizing the operation time at each station, an efficient method of simultaneously moving workpieces in and out can be achieved.

[0123] If the second configuration process is completed and the new workpiece 1300 is moved in, the second welding process is executed. In the second welding process, a second preparation process and a second irradiation process are performed on every 12 of the 48 welding target locations 90 between the third and fourth turns. Furthermore, the second preparation process is a preparation process for performing the second irradiation process. That is, firstly, as process number 12, the second preparation process locks the coil sheets 52 of the initial 12 welding target locations 90 using the clamp 80 (an example of a second clamp) at station ST2 (refer to E12). Figure 13A Next, as the second irradiation step (step number 13), welding is performed on the 12 welding target locations 90 of the locked coil sheet 52 (see E13). In the second irradiation step, the laser head 72A sequentially changes the scanning area (see...). Figures 15A-15C While irradiating 12 welding target areas 90 sequentially with laser beam 110, as part of the second preparation step (step number 14), after unlocking, the workpiece 1300 is rotated 7.5 degrees. After rotation, the coil plates 52 of the next 12 welding target areas 90 are locked by the clamp 80 (see E14). Then, as part of the second irradiation step (step number 15), welding is performed in the same way (see E15). This second preparation step and second irradiation step are repeated for every 12 locations (see E16 to E19). When all 48 welding target areas 90 are completed, the second welding step of the workpiece 1300 is completed by unlocking (see E20).

[0124] Here, in Figure 18 In the example shown, such as Figure 18 As shown in E1 to E20 during the execution period, there is a time difference between the first irradiation process and the second irradiation process. For example, the second irradiation process of process number 13 is executed after the first irradiation process of process number 3 (refer to the dashed arrow R180), and the first irradiation process of process number 5 is executed after the second irradiation process of process number 13 (refer to the dashed arrow R181), and so on.

[0125] Thus, according to Figure 18 In the example shown, since the first irradiation step and the second irradiation step are performed with a time difference, therefore, the following can be achieved: Figure 16B The head-switching type laser irradiation device 70A shown can realize both the first irradiation process and the second irradiation process. That is, the laser beams 110 used in the first irradiation process and the second irradiation process are generated based on the same laser oscillator 71A. Thus, by using the common laser oscillator 71A, the first welding process and the second welding process can be realized efficiently.

[0126] In addition, Figure 18 In the example shown, to create a time difference between the first irradiation step and the second irradiation step, the second irradiation step of step 13 is executed after the completion of the second preparation step of step 12 (a preparation step executed concurrently with the first preparation step of step 2), waiting for a time corresponding to that time difference. However, in a variant example, as long as the same time difference can be created, the second preparation step of step 12 can also be executed in a manner that creates a time difference relative to the first preparation step of step 2.

[0127] In addition, Figure 18 In the example shown, the first irradiation step and the second irradiation step are executed simultaneously with the second preparation step. Specifically, the first preparation steps for steps 4, 6, and 8 are executed during the execution periods E13, E15, and E17 of the second irradiation step, respectively, and the second preparation steps for steps 12, 14, 16, and 18 are executed during the execution periods E3, E5, E7, and E9 of the first irradiation step, respectively. This minimizes the waiting time during the switch between the first and second irradiation steps.

[0128] In this respect, Figure 18 In the example shown, the first irradiation step and the second irradiation step are executed consecutively, with the second irradiation step starting shortly after the first irradiation step is completed. That is, the waiting time during the switch between the first and second irradiation steps is practically zero. In this case, the laser oscillator 71A alternately inputs laser beams (seed light) to the laser heads 72 and 72A via the beam switching function virtually without interruption. That is, in Figure 18 In the example shown, using Figure 16BThe head-switching type laser irradiation apparatus 70A shown implements the process of switching between a first state where the laser oscillator 71A and the laser head 72 (an example of a first laser head) are connected, and a second state where the laser oscillator 71A and the laser head 72A (an example of a second laser head) are connected, in a manner that virtually eliminates the stop period of the laser oscillator 71A (refer to arrows R180, R181). However, in a modified example, the first irradiation process and the second irradiation process can also be performed such that the second irradiation process begins shortly after the completion of the first irradiation process via a brief stop period.

[0129] In addition, Figure 18 In the example shown, the first irradiation steps of steps 5, 7, and 9 are performed concurrently with the second preparation steps of their corresponding steps 14, 16, and 18 throughout their execution, but this is not a limitation. That is, the simultaneous execution of the first irradiation steps and the second preparation steps is arbitrary; it can be a combination of the first irradiation steps (part or all) and the second preparation steps (part or all) being performed simultaneously. This also applies to the second irradiation steps.

[0130] In addition, Figure 18 In the example shown, the first preparation step and the second preparation step may also include position correction performed using the position determination unit 760 described above. The position correction performed using the position determination unit 760 can be performed after the fixture 80 is locked. In this case, position correction can be performed on all welding target locations 90 (i.e., 12 welding target locations 90) in all scanned areas whenever the workpiece 1300 rotates 7.5 degrees. Alternatively, the position correction performed by the position determination unit 760 can also be performed during the first welding step and the second welding step when the scanned area changes. In this case, position correction for 8 of the 12 locations is performed during the first welding step and the second welding step when the scanned area changes.

[0131] In addition, Figure 18 In the example shown, the following was utilized: Figure 16B The head-switching type laser irradiation device 70A shown is an example, but as described above, it can also be used... Figure 16A The laser irradiation device 70 shown is a head-moving type. In this case, when switching as indicated by arrows R180 and R181, it is sufficient to perform the process of moving the laser head 72 between station ST1 and station ST2.

[0132] However, refer to Figure 13A and Figure 13BAs described above, the fixture 80 located at station ST1 holds a coil piece 52 with two turns (the first and second turns in the case of station ST1). However, the fixture applicable to this embodiment is not limited to such a fixture 80. For example, the fixture located at station ST1 can also be implemented by a combination of a fixture holding the first and second turns of the coil piece 52 (hereinafter also referred to as "fixture 80A"), a fixture holding the third and fourth turns of the coil piece 52 (hereinafter also referred to as "fixture 80B"), and a third fixture holding the fifth and sixth turns of the coil piece 52 (hereinafter also referred to as "fixture 80C").

[0133] Next, the cases where the aforementioned fixtures 80A to 80C are installed at workstations ST1 and ST2 will be described. Furthermore, in this case, at each of workstations ST1 and ST2, the coil piece 52, consisting of a total of 48 welding target locations 90, including 12 locations between the first and second turns, 12 locations between the third and fourth turns, and 12 locations between the fifth and sixth turns, can be simultaneously held (locked).

[0134] For the sake of distinction, this type of clamp will also be referred to as a "6-turn retaining clamp" below, see reference. Figure 13A and Figure 13B The aforementioned type of clamp 80 is also referred to as a "2-turn holding type clamp 80".

[0135] Compared to using a 2-turn holding type clamp 80, using a 6-turn holding type clamp can hold more coil pieces 52, thus correspondingly shortening the time required for the welding process. Furthermore, in this embodiment, the 48 welding locations 90 between the first and second turns, the 48 welding locations 90 between the third and fourth turns, and the 48 welding locations 90 between the fifth and sixth turns are welding locations 90 in the general section (excluding the neutral point and the power line portion), totaling 48 × 3 = 244 locations.

[0136] Therefore, when using the 2-turn retaining type clamp 80, with the cooperation of stations ST1 to ST3, 244 / 12 = 12 locking actions based on clamp 80 are required. As a result, in each of stations ST1 to ST3, 12 / 3 = 4 locking actions based on clamp 80 can be performed (see reference). Figure 18 ).

[0137] In contrast, when using a 6-turn retaining fixture, with the cooperation of stations ST1 to ST3, 244 / 36 = 4 locking operations based on the 6-turn retaining fixture are required. In this case, to equalize the time of each welding operation at stations ST1 to ST3, the locking operation based on the 6-turn retaining fixture can be performed twice at each of stations ST1 to ST3 (see reference). Figure 18 In this case, one of the two scans can be performed simultaneously with the execution of all welds in scanning areas 1400A to 1400C, while the remaining scan can be performed simultaneously with the execution of one weld in scanning areas 1400A to 1400C (see reference). Figure 18 ).

[0138] Figure 19 This is an illustrative diagram illustrating an example of a collaborative welding process at station ST1 and a second welding process at station ST2, achievable using a 6-turn retaining fixture. Figure 19 In the middle, with the above Figure 18 Similarly, the process number, process content, and irradiation sequence are shown on the left, while the execution periods E22 to E42 for each process number are represented by bars on the right. The execution periods E22 to E42 for each process number are represented by a time sequence where time flows more as it moves to the right. Furthermore, in Figure 19 In the diagram, scanning areas 1400A to 1400C are labeled as "scanning areas A to C".

[0139] Process numbers 22 to 31 refer to various processes performed at workstation ST1, executed in ascending order of process number. In this case, process numbers 22 to 29 (refer to reference numeral 1900) involve 36 welding object locations 90 (all of the scanning areas 1400A to 1400C), and process numbers 30 and 31 (refer to reference numeral 1903) involve 12 of the 36 welding object locations 90 (scanning area 1400A of the scanning areas 1400A to 1400C).

[0140] In addition, process numbers 33 to 42 are various processes performed at workstation ST2, executed in ascending order of process number. In this case, process numbers 33 to 40 (refer to reference numeral 1902) involve 36 welding object locations 90 (all of the scanning areas 1400A to 1400C), and process numbers 41 and 42 (refer to reference numeral 1904) involve 12 of the 36 welding object locations 90 (scanning area 1400B of scanning areas 1400A to 1400C).

[0141] Specifically, at station ST1, the first configuration operation, operation number 22, is executed first. In the first configuration operation, a new workpiece 1300 is moved into station ST1 and a completed workpiece 1300 is moved from station ST1 to station ST2 (see E22).

[0142] If the first configuration process is completed and the new workpiece 1300 is moved in, the first welding process is executed. In the first welding process, a first preparation process and a first irradiation process are performed on every 12 of the 48 welding target locations 90 in the first welding process. That is, firstly, as the first preparation process (process number 23), a 6-turn holding type fixture (an example of a first fixture) at station ST1 is used to perform locking at 36 locations, and scanning of area 1400A is performed. Figure 15A The initial 12 welding target locations 90 within the scanning area 1400A are corrected (see E23). Next, as the first irradiation step (step number 24), welding is performed on the 12 welding target locations 90 of the locked coil sheet 52 (within the scanning area 1400A) (see E24). In this first irradiation step, the laser head 72 fixes the scanning area within the scanning area 1400A (…). Figure 15A In the state of ), laser beam 110 is sequentially irradiated onto 12 welding object locations 90. Next, as the first preparatory step of process number 25, in order to move the scanning area from scanning area 1400A ( Figure 15A Switch to scan area 1400B ( Figure 15B ) Perform a 120-degree rotation of the laser head 72 (refer to) Figure 14 ), Perform scan on area 1400B ( Figure 15B The next 12 welding target locations 90 within the range are corrected in position (refer to E25). Then, as the first irradiation step of step number 26, welding is performed in the same way (refer to E26). This first preparation step and first irradiation step are repeated for every 12 locations (refer to E27, E28). If welding of 36 welding target locations 90 is completed, the first preparation step of step number 29 is performed. In the first preparation step of step number 29, after unlocking, the workpiece 1300 is rotated (for example, 7.5 degrees counterclockwise), and then locked (refer to E29). Furthermore, as the first preparation step of step number 30, scanning area 1400A is performed. Figure 15AThe positions of the 12 welding target locations 90 within the area are corrected (refer to E30). Next, as the first irradiation step (step number 31), welding is performed on the 12 welding target locations 90 (within the scanning area 1400A) of the locked coil sheet 52 (refer to E31). This first preparation step and first irradiation step (refer to E23-E31) are repeated for every 12 locations. If welding of all 48 welding target locations 90 is completed, the area is unlocked (in... Figure 19 Not shown in the image, please refer to the diagram. Figure 18 (E20), the first welding process of workpiece 1300 is completed.

[0143] In workstation ST2, the same process as in workstation ST1 is performed.

[0144] Specifically, at station ST2, firstly, the second configuration step, step number 33, is executed. In the second configuration step, a new workpiece 1300 (from workpiece 1300 at station ST1) is moved to station ST2, and a completed workpiece 1300 is moved from station ST2 to station ST3 (refer to E33). Here, as an example, workpiece 1300 is configured with its position rotated 15 degrees clockwise relative to its position at station ST1.

[0145] If the second configuration process is completed and the new workpiece 1300 is moved in, the second welding process is executed. In the second welding process, a second preparation process and a second irradiation process are performed on every 12 of the 48 welding target locations 90 in the second welding process. That is, firstly, as the second preparation process (process number 34), a 6-turn holding type fixture (an example of a second fixture) at station ST2 is used to perform locking at 36 locations, and scanning of area 1400A is performed. Figure 15A The initial 12 welding target locations 90 within the scanning area 1400A are corrected (see E34). Next, as a second irradiation step (step number 35), welding is performed on the 12 welding target locations 90 of the locked coil sheet 52 (within the scanning area 1400A) (see E35). In this second irradiation step, the laser head 72A fixes the scanning area within the scanning area 1400A (…). Figure 15A In the state of ), laser beam 110 is sequentially irradiated onto 12 welding objects. Next, as the second preparation step (process number 36), in order to move the scanning area from scanning area 1400A (… Figure 15A Switch to scan area 1400B ( Figure 15B ) Perform a 120-degree rotation of the laser head 72A (refer to) Figure 14 ), Perform scan on area 1400B ( Figure 15BThe next 12 welding target locations 90 within the range are corrected in position (refer to E36). Then, as the second irradiation step (step number 37), welding is performed in the same way (refer to E37). This second preparation step and second irradiation step are repeated for every 12 locations (refer to E38, E39). If welding of the 36 welding target locations 90 is completed, the second preparation step (step number 40) is performed. In the second preparation step (step number 40), after unlocking, the workpiece 1300 is rotated (e.g., 15 degrees counterclockwise), and after rotation, it is locked (refer to E40). Furthermore, as the second preparation step (step number 41), scanning area 1400A is performed. Figure 15A The positions of the 12 welding target locations 90 within the area are corrected (refer to E41). Next, as the second irradiation step (step number 42), welding is performed on the 12 welding target locations 90 of the locked coil sheet 52 (within the scanning area 1400A) (refer to E42). This second preparation step and second irradiation step are repeated for every 12 locations (refer to E23-E31). If welding of all 48 welding target locations 90 is completed, the position is then unlocked (in... Figure 19 Not shown in the image, please refer to the diagram. Figure 18 (E20), the second welding process of workpiece 1300 is completed.

[0146] Here, in Figure 19 In the example shown, such as Figure 19 As shown in E22 to E42 during the execution period, and Figure 18 Similarly, in the examples shown, the first irradiation step and the second irradiation step have a time difference. For example, the second irradiation step of step number 35 is performed after the first irradiation step of step number 24 (refer to the dashed arrow R180), and the first irradiation step of step number 26 is performed after the second irradiation step of step number 35 (refer to the dashed arrow R181), and so on.

[0147] Thus, according to Figure 19 In the example shown, since the first irradiation step and the second irradiation step are performed with a time difference, therefore, the following can be achieved: Figure 16B The head-switching type laser irradiation device 70A shown can realize both the first irradiation process and the second irradiation process. That is, the laser beams 110 used in the first irradiation process and the second irradiation process are generated based on the same laser oscillator 71A. Thus, by using the common laser oscillator 71A, the first welding process and the second welding process can be realized efficiently.

[0148] In addition, Figure 19In the example shown, to create a time difference between the first irradiation step and the second irradiation step, the second irradiation step of step 35 is executed after the completion of the second preparation step of step 34 (a preparation step executed concurrently with the first preparation step of step 23), waiting for a time corresponding to that time difference. However, in a variant example, as long as the same time difference can be created, the second preparation step of step 34 can also be executed in a manner that creates a time difference relative to the first preparation step of step 23.

[0149] In addition, Figure 19 In the example shown, the first irradiation step and the second irradiation step are executed simultaneously with the second preparation step. Specifically, the first preparation steps for steps 25, 27, and 29 are executed during the execution periods E35, E37, and E39 of the second irradiation step, respectively, and the second preparation steps for steps 36, 38, and 40 (or 40) are executed during the execution periods E26, E28, and E31 of the first irradiation step. This minimizes the waiting time during the switch between the first and second irradiation steps.

[0150] In this respect, Figure 19 In the example shown, the first irradiation step and the second irradiation step are executed consecutively, with the second irradiation step starting shortly after the first irradiation step is completed. That is, in Figure 19 In the example shown, using Figure 16B The head-switching type laser irradiation apparatus 70A shown implements the process of switching between a first state where the laser oscillator 71A and the laser head 72 (an example of a first laser head) are connected, and a second state where the laser oscillator 71A and the laser head 72A (an example of a second laser head) are connected, in a manner that virtually eliminates the stop period of the laser oscillator 71A (refer to arrows R180, R181). However, in a modified example, the first irradiation process and the second irradiation process can also be performed such that the second irradiation process begins shortly after the completion of the first irradiation process via a brief stop period.

[0151] In addition, Figure 19 In the example shown, the first irradiation steps of steps 26 and 28 are performed concurrently with the corresponding second preparation steps of steps 36 and 38 throughout their execution, but this is not a limitation. That is, the simultaneous execution of the first irradiation steps and the second preparation steps is arbitrary; it can be a combination of the first irradiation steps (part or all) and the second preparation steps (part or all) being performed simultaneously. This also applies to the second irradiation steps.

[0152] In addition, Figure 19 In the example shown, the following was utilized: Figure 16B The head-switching type laser irradiation device 70A shown is an example, but as described above, it can also be used... Figure 16A The laser irradiation device 70 shown is a head-moving type. In this case, when switching as indicated by arrows R180 and R181, it is sufficient to perform the process of moving the laser head 72 between station ST1 and station ST2.

[0153] In addition, Figure 19 In the example shown, both the first preparation step and the second preparation step include position correction using the position determination unit 760 described above, but this position correction may be omitted.

[0154] In addition, Figure 19 In the example shown, position correction is performed in the first welding process (and similarly for the second welding process), prior to each first irradiation process. In this case, position correction for 8 out of 12 locations is performed in both the first and second welding processes when the scanned area changes.

[0155] However, in a modified example, after locking, the positions of the 36 welding target locations 90 within the three scanning areas 1400A to 1400C can also be corrected simultaneously. In this case, the waiting time of the first second irradiation step in the second welding process (the time from the completion of the second preparation step of the second welding process to the completion of the first first irradiation step in the first welding process, hereinafter also referred to as "welding waiting time") becomes longer, but it is possible to obtain the same... Figure 19 The example shown has the same effect. Hereinafter, such a variation will also be referred to as the "first variation".

[0156] Specifically, Figure 20A yes Figure 19 The diagram illustrates the welding wait time in the example shown. Figure 20B This is an explanatory diagram of the welding waiting time in the first modified example. Figure 20A and Figure 20B In this context, for each irradiation step (first irradiation step and second irradiation step) and various preparation steps (first preparation step and second preparation step), the execution period is represented sequentially by bar segments E22–E42 and E50–E66. Furthermore, in… Figure 20A In the middle, to and Figure 19 The execution periods E22 to E42 shown actually correspond to the same reference numerals E22 to E42 in the attached figures. In this case, execution period E23 (and the same applies to execution period E34) is represented by two separate execution periods E23-1 and E23-2.

[0157] By Figure 20A and Figure 20B A comparison reveals that, compared to the first variant, in Figure 19 In the example shown, the welding waiting time ΔT1 can be shortened.

[0158] Specifically, in the first modified example, the position correction is performed simultaneously on 36 welding object locations 90 within the three scanning areas 1400A to 1400C, therefore, as Figure 20B As shown, with Figure 19 The example shown (refer to) Figure 20A Compared to the execution period E23-2, the execution period E52 for position correction becomes longer. Therefore, in the case of the first modified example, the waiting time until the first second irradiation process can be started (the second irradiation process relative to the 36 welding target parts 90), i.e., the welding waiting time ΔT1, becomes longer.

[0159] In contrast, according to Figure 19 In the example shown, the position correction is performed in a distributed manner, with 12 locations at each of the 36 welding object sites 90 within the three scanning areas 1400A to 1400C (see reference). Figure 19 and Figure 20A (E23, E25, E27). Therefore, compared to the case of the first variation, in Figure 19 In the example shown, the waiting time, i.e., the welding waiting time ΔT1, can be significantly shortened until the first second irradiation process (relative to the second irradiation process of the 12 welding object parts 90) can begin. As a result, the overall time for both the first and second welding processes can be reduced.

[0160] Furthermore, in the case of the first variation, the execution period E63 of a second irradiation step is relatively long, therefore the welding waiting time ΔT2 of the second first irradiation step (relative to the second irradiation step of the 12 weldable parts 90) tends to be longer. In contrast, according to... Figure 19 In the example shown, because the execution period E63 of the second irradiation step is relatively short, the welding waiting time for the second and subsequent first irradiation steps can be significantly shortened compared to the case of the first variation. Figure 19 In the process, the welding waiting time for the second and subsequent first irradiation steps is 0.

[0161] The embodiments have been described in detail above, but are not limited to specific embodiments. Various modifications and alterations are possible within the scope of the claims. Furthermore, all or more of the constituent elements of the above embodiments can be combined.

[0162] For example, in the above embodiment, when using a 6-turn retaining type fixture, the welding of the general part is achieved through the cooperation of stations ST1, ST2, and ST3, but it is not limited to this. For example, when using a 6-turn retaining type fixture, the welding of the general part of the stator coil 24 can also be achieved through the cooperation of four stations, including stations ST1, ST2, and ST3, as well as a further station. In this case, in each of the four stations including stations ST1, ST2, ST3, and the further station, the locking is only required once, which can further improve the efficiency.

[0163] In addition, in the above embodiments, the laser oscillator 71 and laser head 72 (or laser oscillator 71A) are shared between two workstations, but the laser oscillator 71 and laser head 72 (or laser oscillator 71A) can also be shared between three or more workstations.

[0164] Explanation of reference numerals in the attached figures

[0165] 1…motor (rotary motor), 24…stator coil, 52…coil piece, 40…front end, 401…abutment surface, 110…laser beam, 90…welding object part.

Claims

1. A method for manufacturing a stator for a rotating electric motor, wherein the stator coil is formed from multiple coil segments in the form of segmented coils, the method being characterized in that it includes: The first configuration process involves configuring a workpiece for the stator at the first workstation. In the first welding process, at the first station, the welding of the first part of the stator coil in the workpiece is completed; The first welding process includes a first irradiation process of irradiating the coil sheet of the first part of the object to be welded with a welding laser beam. The second configuration process involves configuring another workpiece for the stator at the second station; and In the second welding process, at the second station, the welding of the second portion of the stator coil in the other workpiece is completed. The second welding process includes a second irradiation process in which a welding laser beam is irradiated onto the coil sheet of the welding object in the second part. The first irradiation step and the second irradiation step have a time difference, and the laser beams used in the first irradiation step and the second irradiation step are generated based on the same oscillator. The first welding process further includes a first preparation process for performing the first irradiation process. The second welding process further includes a second preparation process for performing the second irradiation process. The first irradiation step and the second preparation step are performed simultaneously. The second irradiation step is performed simultaneously with the first preparation step. The first preparation step includes a first holding step in which the front ends of the coil pieces of the first part to be welded are held together by a first clamp. The second preparation step includes a second holding step in which the front ends of the coil pieces of the second part of the welding object are held together by a second clamp. The first irradiation step and the second holding step are performed simultaneously. The second irradiation process and the first holding process are performed simultaneously.

2. The method for manufacturing a stator for a rotary electric machine according to claim 1, characterized in that, The first preparation step includes a first position determination step, which determines the irradiation position of the laser beam in the first irradiation step based on a first image obtained by photographing the coil sheet of the first part of the welding object. The first preparation step includes a second position determination step, which determines the irradiation position of the laser beam in the second irradiation step based on a second image obtained by photographing the coil sheet of the welding object in the second part. The first irradiation step and the second position determination step are executed simultaneously. The second irradiation process is executed simultaneously with the first position determination process.

3. The method for manufacturing a stator for a rotating electric machine according to claim 1, characterized in that, The first configuration step and the second configuration step include moving the other workpiece, which has completed the welding of the second part in the second welding step, out of the second station, moving the one workpiece, which has completed the welding of the first part in the first welding step, into the second station, and moving a new workpiece into the first station.

4. The method for manufacturing a stator for a rotary electric machine according to claim 2, characterized in that, The first configuration step and the second configuration step include moving the other workpiece, which has completed the welding of the second part in the second welding step, out of the second station, moving the one workpiece, which has completed the welding of the first part in the first welding step, into the second station, and moving a new workpiece into the first station.

5. The method for manufacturing a stator for a rotating electric machine according to any one of claims 1 to 4, characterized in that, The first irradiation step involves irradiating the laser beam from the first laser head. The second irradiation process involves irradiating the laser beam from the first laser head. It also includes a process of moving the first laser head between the first station and the second station.

6. The method for manufacturing a stator for a rotating electric machine according to any one of claims 1 to 4, characterized in that, The first irradiation step involves irradiating the laser beam from the first laser head. The second irradiation process involves irradiating the laser beam from the second laser head. It also includes a process of switching between a first state in which the oscillator and the first laser head are connected and a second state in which the oscillator and the second laser head are connected.

7. The method for manufacturing a stator for a rotating electric machine according to any one of claims 1 to 4, characterized in that, The laser beam has a wavelength of less than 0.6 μm. The first irradiation process includes: The process of irradiating the laser beam from a laser head positioned at a first location covering a first region of the workpiece; and The process of irradiating the laser beam from a laser head positioned at a second location covering a second region of the workpiece. The second irradiation process includes: The process of irradiating the laser beam from a laser head positioned in a third location covering a third region of the other workpiece; and The process of irradiating the laser beam from a laser head positioned at a fourth location covering a fourth region of the workpiece.

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