Welding method and jig

Abstract

The present invention provides a welding method which makes it possible to suppress variations in welding inside an assembly. Provided is a welding method in which welding is performed with a conductive wire 15 and a terminal 17 inside an assembly 1 brought into contact with each other, wherein a jig 19 which is operable from the outside of the assembly 1 is driven to cause a contact between the conductive wire 15 and the terminal 17. By managing this drive force of the jig 19, welding is performed with a predetermined pressing force applied between the conductive wire 15 and the terminal 17.

Description

Welding method and jig

[0001] The present invention relates to a welding method and a jig used for welding a stator of a rotating electrical machine or the like.

[0002] A conventional welding method is described in Patent Document 1. In this welding method, a bus bar of a stator of a rotating electric machine has a conductor connection portion as a terminal, and the conductor connection portion is held by crimping a side wall portion that is bent to surround, for example, two conductor wires of a coil. In this held state, the conductor connection portion and the conductor wires are joined by arc welding.

[0003] In the welding method described in Patent Document 1, variations in the accuracy of various dimensions and the crimping process may result in variations in the contact area and contact pressure between the conductive wires and the conductive wire connecting portions.

[0004] Generally, welding provides good thermal conductivity when the contact area and pressure between two parts are large and strong. In other words, welding preferentially begins to melt areas with good thermal conductivity. Therefore, if there is variation in the contact area and pressure between the electric wire and the conductive wire connection, for example, areas with weak contact pressure will not penetrate sufficiently, which can easily lead to variations in the welding.

[0005] In contrast, if the welding time is increased, it is possible to fully melt the entire weld. However, inside assemblies such as stators, the weld area is surrounded by conductive wires, insulating coatings for coils, and surrounding resin materials, and the welding time is limited from the standpoint of heat resistance.

[0006] Patent No. 5417721

[0007] The problem that is being solved is the tendency for welding within the assembly to be variable.

[0008] The present invention provides a welding method for welding a conductive wire of a coil and a terminal of a bus bar inside an assembly by bringing them into contact with each other, by driving a jig from outside the assembly to bring one of the conductive wire of the coil and the terminal of the bus bar into contact with the other of the conductive wire of the coil and the terminal of the bus bar by applying a pressing force from the jig, and by controlling the driving force of the jig to perform the welding while keeping the pressing force within a specified range.

[0009] The present invention also provides a jig for use in the welding method. The jig includes a base member supporting the assembly, a movable body movable relative to the base member, a pressing unit provided on the movable body and oriented toward one of the conductive wires of the coil and the terminals of the bus bar across the other of the conductive wires of the coil and the terminals of the bus bar, and a drive unit that moves the movable body to bring the other of the conductive wires of the coil and the terminals of the bus bar into contact with the one of the conductive wires of the coil and the terminals of the bus bar with a pressing force exerted by the pressing unit. The drive unit controls the driving force of the movable body to keep the pressing force within a specified range.

[0010] The present invention can reduce welding variations within an assembly.

[0011] Fig. 1 is a perspective view of a stator according to an embodiment. Fig. 2 is a perspective view showing a jig supporting the stator of Fig. 1. Fig. 3 is an exploded perspective view showing the stator and jig of Fig. 1. Fig. 4 is a cross-sectional view showing the jig of Fig. 2. Fig. 5 is an enlarged plan view of a portion of the jig of Fig. 2. Fig. 6 is an enlarged cross-sectional view of a portion of the jig of Fig. 2. Fig. 7 is an enlarged plan view of a portion of Fig. 5.

[0012] The objective of suppressing welding variations within the assembly was achieved by using a jig to ensure that the coil's conductive wires and the bus bar terminals are in contact with each other with a specified pressure.

[0013] The welding method involves bringing the conductive wire 15 of the coil 7 inside the assembly 1 and the terminal 17 of the bus bar 9 into contact with each other and welding them together. In this welding method, a jig 19 is driven from outside the assembly 1, and one 17 of the conductive wire 15 and the terminal 17 is brought into contact with the other 15 of the conductive wire 15 and the terminal 17 by applying a pressing force from the jig 19. By controlling the driving force of this jig 19, welding is performed while keeping the pressing force within a specified range.

[0014] The conductive wires 15 and terminals 17 inside the assembly 1 to be welded can be conductive wires and busbar terminals of rotating electrical machines or power electronic devices.

[0015] In one embodiment, the assembly 1 is an assembly used in a rotating electrical machine.

[0016] The conductive wire 15 may be pressed at a position offset in the axial direction of the conductive wire 15 from the contact portion between the conductive wire 15 and the terminal 17, so that the conductive wire 15 comes into contact with the terminal 17.

[0017] The edge of the terminal 17 may have an edge recess 17a for positioning the conductive wire 15. In this case, the conductive wire 15 contacts the terminal 17 at the edge recess 17a.

[0018] There is no particular limitation on the number of conductive wires 15 welded to the terminal 17. In one embodiment, at least two conductive wires 15 may be arranged in parallel and brought into contact with the terminal 17 with a specified pressing force.

[0019] The jig 19 used in this welding method includes a base member 21, a movable body 23, a pressing unit 25, and a drive unit 27. The base member 21 supports the assembly 1. The movable body 23 is provided so as to be movable relative to the base member. The pressing unit 25 is provided on the movable body 23 and is oriented toward one of the conductive wire 15 and the terminal 17, sandwiching the other of the conductive wire 15 and the terminal 17 therebetween. The drive unit 27 moves the movable body 23 to bring the other of the conductive wire 15 and the terminal 17 into contact with the one of the conductive wire 15 and the terminal 17 with the pressing force of the pressing unit 25. The drive unit 27 controls the driving force of the movable body 23 to keep the pressing force within a specified range.

[0020] The pressing portion 25 may have any suitable shape, and in one embodiment may have a concave pressing surface 53 c for pressing against the conductive wire 15 .

[0021] The pressing portion 25 may be integral with or separate from the movable body 23, but may be configured as a separate body and supported by the movable body 23 in a replaceable manner.

[0022] The movable body 23 may include a slide portion 45 and a pressing force transmission portion 47. The slide portion 45 moves along the base member 21 in conjunction with the drive portion 27. The pressing force transmission portion 47 is provided integrally with the slide portion 45 and is connected to the pressing portion 25.

[0023] In one embodiment, the drive unit 27 may include a drive bolt 49. The drive bolt 49 has a radially inner portion that penetrates the base member 21 in the radial direction and threads into the movable body 23, and a radially outer portion that protrudes from the base member 21 so as to be rotatable about its axis.

[0024] The base member 21 may include a cover 37 via a stud portion 35. The stud portion 35 is provided upright on the base member 21, and the cover 37 covers the coil 7 and the bus bar 9. The cover 37 includes an access window 41 that exposes the terminal 17 and the conductive wire 15.

[0025] [Stator] FIG. 1 is a perspective view of an example of a stator.

[0026] The stator 1 in Fig. 1 and a rotor (not shown) constitute a rotating electric machine. This rotating electric machine is configured as, for example, a three-phase (U-phase, V-phase, and W-phase) AC motor. In the following description, the terms "radial direction," "circumferential direction," and "axial direction" refer to the radial direction, circumferential direction, and axial direction of the stator 1.

[0027] The stator 1 includes a stator core 3, insulators 5, coils 7, bus bars 9, etc. The stator 1 is an example of the assembly of this embodiment, and other configurations may also be adopted. Furthermore, the assembly is not limited to the stator 1, which is an assembly of a rotating electrical machine, but may also be a power electronics device or the like.

[0028] The stator core 3 is formed by laminating, for example, a plurality of annular electromagnetic steel plates. The stator core 3 has a yoke 11 and teeth 13, and is covered with the insulator 5 as described above. Each tooth 13 is wound with a conductive wire 15 covered with an insulating film, and the wound conductive wire 15 forms the coil 7. In this embodiment, the conductive wire 15 has a circular cross section.

[0029] The bus bars 9 are conductive members for supplying three-phase drive current to the coils 7. The bus bars 9 for each phase are routed appropriately from connectors 18 over the insulators 5 and connected to the coils 7. For this reason, the bus bars 9 are provided with terminals 17 for connection to the coils 7.

[0030] Terminal 17 extends radially inward from bus bar 9 and protrudes in the shape of a plate having a width in the circumferential direction. The radially inner edge of terminal 17 is joined to the end portion of conductive wire 15 of coil 7 by welded portion W (see FIG. 7 ). Each end of bus bar 9 is arranged in connector 18 as three-phase connector terminals 18a, 18b, and 18c.

[0031] [Welding Method] The welding method of this embodiment is to weld the conductive wire 15 of the coil 7 of the starter 1 to the terminal 17 of the bus bar 9. During this welding, the conductive wire 15 is brought into contact with the terminal 17 using a jig 19.

[0032] Fig. 2 is a perspective view showing the jig 19 supporting the stator 1 of Fig. 1. Fig. 3 is an exploded perspective view showing the stator 1 and jig 19 of Fig. 2, with the cover 37 omitted. Fig. 4 is a cross-sectional view of the jig 19 of Fig. 2. Fig. 5 is an enlarged plan view showing a part of the jig 19 of Fig. 2, with the cover 37 omitted.

[0033] 2 to 5, the jig 19 used in the welding method of this embodiment constitutes a jig that can be driven from outside the stator 1. This jig 19 is driven to bring the conductive wires 15 of the coils 7 into contact with the terminals 17 of the bus bars 9 with a pressing force, and the driving force is controlled to keep the pressing force within a specified range. In this embodiment, the jig 19 includes a base member 21, a movable body 23, a pressing unit 25, and a driving unit 27.

[0034] The base member 21 supports the stator 1 on one side in the axial direction. In this embodiment, the base member 21 is formed in a plate shape and has a hexagonal planar shape. However, the shape of the base member 21 is not particularly limited. A recess 29 is formed in the center of the base member 21. The recess 29 is recessed in the thickness direction of the base member 21 and is open at the top. Here, "top" refers to the top in the drawing and does not necessarily refer to the vertical direction.

[0035] In this embodiment, the thickness direction of the base member 21 coincides with the axial direction of the stator 1. The central portion of the base member 21 is the portion excluding the outer periphery of the base member 21. The planar shape of the recess 29 is not particularly limited, but is circular in this embodiment.

[0036] A core metal 33 is disposed in the central portion of the recess 29, excluding the outer periphery, via a spacer 31. The outer periphery of the recess 29 is a circular portion surrounding the spacer 31. A plurality of groove-shaped recesses 34 are formed in the outer periphery of this recess 29. Like the recesses 29, each groove-shaped recess 34 is concave in the thickness direction of the base member 21 and is open at the top. In a plan view, the groove-shaped recesses 34 are groove-shaped extending radially outward from the wall portion that defines the recess 29. The plurality of groove-shaped recesses 34 are disposed at intervals in the circumferential direction.

[0037] The circumferential width of the groove-shaped recess 34 corresponds to the width of the slide portion 45 of the movable body 23. The depth of the groove-shaped recess 34 is the same as the depth of the recess 29. The groove-shaped recess 34 is radially connected to an insertion hole 21a formed in the base member 21. The insertion hole 21a penetrates radially from the radial outer surface of the base member 21 to the groove-shaped recess 34.

[0038] Stud bosses 35 are provided as stud portions on the base member 21. The locations and number of the stud bosses 35 are not particularly limited, but in this embodiment, six stud bosses 35 are provided corresponding to the respective corners of the planar shape of the base member 21.

[0039] The stud bosses 35 support at their tips covers 37 that cover the coils 5 and bus bars 9. Through holes (not shown) are formed in the cover 37 corresponding to the stud bosses 35. Bolts 39 are fastened to the female threads (not shown) of the stud bosses 35 via the respective through holes. The cover 37 is attached and detached using the bolts 39.

[0040] The stud portion may be a columnar portion that supports the cover 37, and may be configured such that a stud bolt is attached to the stud boss 35. In this case, a nut is used instead of the bolt 39. Furthermore, as long as the cover 37 can be fixed, bolts, nuts, etc. may not be used.

[0041] The cover 37 is formed in a plate shape, a disk shape in this embodiment, that covers the coil 7 and the bus bar 9. However, there are no particular limitations on the planar shape of the cover 37. The cover 37 has an access window 41 that exposes the terminals 17 and the conductive wires 15, and a cutout 43 for a connector.

[0042] In this embodiment, the work windows 41 are formed in six locations. Each work window 41 has a cross-sectional shape that expands in the thickness direction from the terminal 17 and conductive wire 15 side toward the outer surface of the cover 37. The cross-sectional shape of the work windows 41 is not particularly limited, but in this embodiment, the work windows 41 expand in a stepped shape.

[0043] The cover 37 serves to suppress the influence of heat on the stator 1 during welding, but may be omitted.

[0044] The movable body 23 is provided so as to be movable relative to the base member 21. In this embodiment, the movable body 23 is provided on the base member 21. However, the movable body 23 does not have to be provided on the base member 21 as long as it is configured to be movable relative to the base member 21.

[0045] The movable bodies 23 are arranged along the groove-like recesses 34 and are movable in the radial direction. However, the movement direction of the movable bodies 23 is appropriately set depending on the contact direction between the conductive wires 15 of the coil 7 and the terminals 17 of the bus bars 9.

[0046] The movable body 23 of this embodiment includes a slide portion 45 and a pressure force transmitting portion 47 .

[0047] The slide portion 45 moves along the base member 21 in conjunction with the drive portion 27. The slide portion 45 has a base portion 45a on the radially outer side that is formed to be relatively wide.

[0048] The circumferential width of the base portion 45a corresponds to the width of the groove-shaped recess 34. The base portion 45a fits into the groove-shaped recess 34 and is guided along the groove-shaped recess 34. A tip portion 45b on the radially inner side of the slide portion 45 protrudes toward the spacer 31 and is located below the bottom surface of the core metal 33. Therefore, the slide portion 45 can be stably moved in the radial direction.

[0049] The pressing force transmission part 47 is formed in a columnar shape and stands up in the axial direction from the sliding part 45. A sloped part 47a is formed between the pressing force transmission part 47 and the sliding part 45. The pressing force transmission part 47 supports the pressing part 25, and the pressing part 25 is provided on the movable body 23.

[0050] In a plan view, the pressing portion 25 is oriented radially inward with respect to the terminal 17, sandwiching the conductive wire 15. In this embodiment, the pressing portion 25 is supported at the tip of the pressing force transmission portion 45. However, the pressing portion 25 may also be supported at the middle portion of the pressing force transmission portion 45 in the axial direction, for example.

[0051] The pressing portion 25 is in relatively movably contact with the lower surface of the cover 37. However, the pressing portion 25 can also be separated from the lower surface of the cover 37. Details of the pressing portion 25 will be described later.

[0052] The driving portion 27 is linked to the movable body 23 and moves the movable body 23. This movement of the movable body 23 causes the pressing portion 25 to press the conductive wire 15 against the terminal 17 to bring the conductive wire 15 into contact with the terminal 17.

[0053] In this embodiment, the drive unit 27 is configured with a plurality of drive bolts 49. Each drive bolt 49 penetrates the base member 21 in the radial direction via the insertion hole 21a. The drive bolt 49 penetrates the base member 21 from the inside to the outside in the radial direction and has a radially inner portion that is threadedly engaged with the movable body 23 and a radially outer portion that protrudes from the base member 21 so as to be rotatable about its axis.

[0054] In this embodiment, the radially outer portion of the drive bolt 49 has a head 49a, which is disposed so as to protrude radially outward from the base member 21. A washer 51 is interposed between the head 49a and the outer surface of the base member 21. The head 49a can be rotated about its axis using a tool or device.

[0055] Therefore, the drive unit 27 can move the movable body 23 in the radial direction by rotating the drive bolt 49 .

[0056] The drive bolt 49 may be configured to be threaded into the base member 21 and to be engaged with the movable body 23 so as to be relatively rotatable. In this case, the drive bolt 49 moves radially in response to axial rotation operation to move the movable body 23. The head portion 49 a of the drive bolt 49 may be omitted, and it is sufficient that the drive bolt 49 can be axially rotated using a tool or device within the range that protrudes from the base member 21.

[0057] The driving unit 27 controls the driving force that moves the movable body 23, so that the pressing unit 25 contacts the conductive wire 15 with the terminal 17 with a specified pressing force. In this embodiment, the tightening torque of the driving bolt 49, which serves as the driving force, is controlled, so that the conductive wire 15 can be brought into contact with the terminal 17 with a specified pressing force.

[0058] The driving unit 27 may be another linear actuator using, for example, fluid pressure or solenoid force.

[0059] Fig. 6 is an enlarged cross-sectional view showing a part of the jig 19 of Fig. 2. Fig. 7 is an enlarged plan view of a part of Fig. 5.

[0060] 6 and 7 , each pressing portion 25 includes a wire-facing portion 53 and a cover contact portion 55. The cover contact portion 55 protrudes axially from the wire-facing portion 53. The wire-facing portion 53 is formed in a plate or block shape and includes a plurality of holes 53a and 53b and a pressing surface 53c. The holes 53a and 53b are arranged side by side in the radial direction.

[0061] The holes 53a and 53b are provided along the axial direction, and the fitting pin 47b at the tip of the pressing force transmission part 47 is inserted in the axial direction and fitted into the holes 53a and 53b. By this fitting, the pressing part 25 is supported replaceably with respect to the movable body 23.

[0062] The hole 53a is recessed relative to the wire-facing portion 53, and the hole 53b penetrates the wire-facing portion 53 in the axial direction. The replaceable support of the pressing portion 25 can be achieved by various structures such as fitting, screw fastening, etc. The pressing portion 25 can also be formed integrally with the movable body 23.

[0063] The pressing surface 53c is a surface that comes into contact with and presses the conductive wire 15. In this embodiment, the pressing surface 53c is oriented radially outward and is positioned closer to the base member 21 in the axial direction than the contact portion between the terminal 17 and the conductive wire 15.

[0064] In this embodiment, the pressing surface 53c is concave relative to the conductor 15 in plan view. Specifically, the pressing surface 53c is made up of a pair of inclined surfaces that transition from the circumferential center toward both sides toward the conductor 15. However, the pressing surface 53c may also be made concave with a curved surface or may be made up of a flat surface, etc.

[0065] The pressing surface 53c holds the pair of conductors 15 when the pair of inclined surfaces press the pair of conductors 15. In this embodiment, the pressing surface 53c holds the pair of conductors 15 while applying a force to the pair of conductors 15 that pushes them inward in the circumferential direction.

[0066] The shape of the pressing surface 53c may be formed on the terminal 17. The shape of the edge recess 17a may also be formed on the wire-facing portion 53. One or both of the wire-facing portion 53 and the edge of the terminal 17 may also be formed linearly in a plan view, perpendicular to the radial direction.

[0067] When using such a jig, as shown in Figure 3, the stator 1 before welding is placed inside the stud boss 35 on the base member 21. In this placement, the pressing portion 25 of the jig 19 is positioned so as to be directed radially toward the terminal 17 via the conductive wire 15 in a plan view.

[0068] Next, the cover 37 is attached to the tip of the stud boss 35. That is, the cover 37 is placed on the tip of the stud boss 35, and bolts 39 are fastened to the female threads of the stud boss 35 through the through holes in the cover 37. In this state, the terminals 17 and the conductive wires 15 are exposed in the working windows 41 of the cover 37.

[0069] Then, the conductive wires 15 are brought into contact with the terminals 17. Specifically, when the head portions 49a of the drive bolts 49 are rotated, the slide portions 45 of the movable bodies 23 that are threadedly engaged with the drive bolts 49 are pulled and moved radially outward by the rotation of the drive bolts 49. The rotation of the head portions 49a can be performed automatically by a device such as a robot, or manually by a tool.

[0070] This movement of the movable body 23 causes the pressing force transmission portion 47 to move in the same direction. As a result, the wire-facing portion 53 of the pressing portion 25 presses the conductors 15 with the pressing surface 53c. This pressing force brings the pair of conductors 15 into contact with the terminals 17. The contact is achieved by pressing the pair of conductors 15 against the edge recesses 17a of the terminals 17. In this embodiment, when the pressing portion 25 presses the conductors 15, the pair of inclined surfaces of the pressing surface 53c also press the pair of conductors 15 inward in the circumferential direction, thereby positioning the conductors 15.

[0071] Each edge recess 17a with which the conductive wire 15 comes into contact is formed on the terminal 17 as an arc with approximately the same curvature as the outer peripheral surface of the conductive wire 15. The outer peripheral surfaces of the conductive wire 15 accommodated in the edge recess 17a may be slightly separated in the circumferential direction, but may still be in contact. The edge recess 17a may be omitted. The shape of the edge recess 17a may also be provided on the pressing surface 53c.

[0072] This pressing force causes the conductive wire 15 to come into contact with the terminal 17. At this time, the pressing of the conductive wire 15 is performed at a position shifted in the axial direction of the conductive wire 15 from the contact portion between the conductive wire 15 and the terminal 17. Therefore, the conductive wire 15 comes into contact with the terminal 17 with its own elasticity in response to the pressing force of the jig 19.

[0073] The contact pressure of the conductive wire 15 can be reliably received by the terminal 17 in the direction of the plate-like surface.

[0074] As a result, it is possible to accurately maintain the pressing force of the pressing portion 25 against the terminal 17 via the conductive wire 15 .

[0075] The pressure is increased to a specified value by controlling the tightening torque, which is the driving force of the head portion 49a. The specified pressure is a pressure that provides an appropriate contact pressure for, for example, arc welding, in the contact area between the conductive wire 15 and the terminal 17. The appropriate pressure is a level that allows sufficient penetration of the conductive wire 15, and is set appropriately depending on the welding method and the type of materials to be welded.

[0076] In this embodiment, the tightening torque increases due to the elasticity of the conductive wire 15 in response to the tightening of the drive bolt 49. By controlling this tightening torque, the pressing force of the jig 19 for contacting the conductive wire 15 with the terminal 17 is set within a specified range.

[0077] After the pressing force is adjusted to the specified range, welding is performed on the conductive wires 15 and the terminals 17 in each working window 41. In this embodiment, arc welding is performed, but resistance welding can also be used.

[0078] In arc welding, the coil 7 side is earthed, and the conductor 15 is at a negative voltage via the coil 7. A torch comes into contact through the working window 41 to perform arc welding between the terminal 17 and the conductor 15. The torch is positioned near the contact point between the terminal 17 and the conductor 15. Note that the torch may not be brought into contact with the terminal 17 or the conductor 15.

[0079] This arc welding forms a weld W that joins the contacting portions of the terminals 17 and the conductive wires 15. At this time, the pair of conductive wires 15 are in contact with the terminals 17 uniformly with a specified pressing force, so that uniform and sufficient penetration is achieved.

[0080] As described above, in the welding method of this embodiment, the jig 19, which can be operated from outside the stator 1, is driven to bring the conductor 15 into contact with the terminal 17. Then, by controlling the driving force of the jig 19, welding can be performed while applying a specified pressing force between the conductor 15 and the terminal 17.

[0081] Therefore, the welding quality can be stabilized without variations in the contact area and contact pressure between the conductive wire 15 and the terminal 17. In this embodiment, the welding quality can be uniformly stabilized at a plurality of welding points, and the performance of the stator 1 can be stabilized.

[0082] Furthermore, in each welding portion, the two conductive wires 15 are arranged in parallel and are uniformly brought into contact with the terminals 17 with a specified pressing force, thereby making it possible to suppress variations in the welding of the conductive wires 15 and stabilize the welding quality.

[0083] The conductive wire 15 is pressed at a position offset in the axial direction of the conductive wire 15 from the contact portion between the conductive wire 15 and the terminal 17, and the conductive wire 15 comes into contact with the terminal 17 by its elasticity.

[0084] Therefore, the driving force of the jig 19 can be reliably increased in accordance with an increase in the pressing force for contacting the conductive wire 15 with the terminal 17, and the pressing force can be easily and reliably controlled.

[0085] The conductive wire 15 can be positioned in the edge recess 17a of the terminal 17, making it easier to make the contact area and contact pressure of the conductive wire 15 with the terminal 17 uniform, thereby more reliably stabilizing the welding quality.

[0086] The jig 19 used in the welding method of the present invention supports the stator 1 on the base member 21, and the movable body 23 is moved by rotating the head portion 49a of the drive unit 27, so that the conductive wire 15 can be brought into contact with the terminal 17 by the pressing portion 25.

[0087] At this time, the jig 19 can bring the conductive wire 15 and the terminal 17 into contact with each other with a specified pressing force by controlling the driving force of the movable body 23. Therefore, by welding the conductive wire 15 and the terminal 17 in such a contact state, it is possible to suppress variations in welding and stabilize the welding quality.

[0088] The pressing portion 25 has a pressing surface 53 c that is concave relative to the conductive wire 15 , so that the conductive wire 15 can be positioned relative to the edge of the terminal 17 .

[0089] Therefore, variations in welding can be suppressed, and the welding quality can be more reliably stabilized.

[0090] In this embodiment, since the pressing portion 25 is replaceable relative to the movable body 23, repair or replacement of the pressing portion 25 can easily stabilize the welding quality.

[0091] In the movable body 23, the slide portion 45 linked to the drive portion 27 can be moved accurately along the base member 21. By this movement, force is accurately transmitted to the pressing portion 25 via the pressing force transmission portion 47, and a specified pressing force can be accurately applied to the conductive wire 15.

[0092] The drive unit 27 can rotate the head portion 49a of the drive bolt 49 around its axis on the radial outside of the base member 21, and can reliably transmit the drive force to the pressing portion 25 located radially inside the stator 1.

[0093] REFERENCE SIGNS LIST 1 stator 3 stator core 7 coil 9 bus bar 13 teeth 15 conductive wire 17 terminal 17a edge recess 19 jig 21 base member 23 movable body 25 pressing portion 27 drive portion 35 stud boss (stud portion) 37 cover 41 work window 5 slide portion 47 pressing force transmission portion 49 drive bolt 49a head portion 53 electric wire facing portion 53c pressing surface W welded portion

Claims

1. A welding method for welding a conductive wire of a coil inside an assembly to a terminal of a bus bar by bringing them into contact with each other, comprising the steps of: a jig is driven from outside the assembly to bring one of the conductive wire and the terminal into contact with the other of the conductive wire and the terminal by a pressing force of the jig; the contact between the conductive wire and the terminal is made by pressing the conductive wire with the jig at a position shifted in the axial direction of the conductive wire from a contact portion between the conductive wire and the terminal; The welding is performed while keeping the pressing force within a specified range by controlling the driving force of the jig. Welding method.

2. The welding method of claim 1, The assembly is an assembly used in a rotating electric machine. Welding method.

3. The welding method of claim 1, The terminal edge has an edge recess for positioning the conductive wire, The conductive lines are such that the contact is made in the edge recess. Welding method.

4. The welding method according to any one of claims 1 to 3, At least two of the conductive wires are arranged in parallel and contact the terminals with the specified pressing force. Welding method.

5. A welding method for welding by bringing the conductive wire of a coil inside an assembly and the terminal of a bus bar into contact with each other, wherein a jig is driven from outside the assembly to bring one of the conductive wire and the terminal into contact with the other of the conductive wire and the terminal by the pressing force of the jig, and the welding is performed while keeping the pressing force within a specified range by controlling the driving force of the jig, comprising: a jig used in the welding method; a base member supporting the assembly; a movable body provided so as to be movable relative to the base member; a pressing portion provided on the movable body and directed toward one of the conductive wire of the coil and the terminal of the bus bar, sandwiching the other of the conductive wire of the coil and the terminal of the bus bar; a drive unit that moves the movable body to press the other of the conductive wire of the coil and the terminal of the bus bar against one of the conductive wire of the coil and the terminal of the bus bar with a pressing force from the pressing unit, The driving unit controls the driving force of the movable body to keep the pressing force within a specified range. jig.

6. The jig of claim 5, The pressing portion has a pressing surface that is concave with respect to the conductive wire. jig.

7. The jig of claim 5, The pressing portion is supported replaceably on the movable body. jig.

8. The jig of claim 5, The movable body includes a slide portion that moves along the base member in conjunction with the drive portion, and a pressing force transmission portion that is integrally provided on the slide portion and coupled to the pressing portion. jig.

9. The jig of claim 5, the drive portion includes a drive bolt; the drive bolt radially penetrates the base member and includes an inner radial portion threadedly engaged with the movable body and an outer radial portion protruding from the base member so as to be rotatable about its axis; jig.

10. The jig according to any one of claims 5 to 9, The base member has a stud portion extending upright therefrom, the stud portion supports a cover that covers the coil and the bus bar; The cover has an access window through which the terminals and the conductive wires are exposed. jig.