Method of joining the neutral wire

Abstract

The present invention provides a method for joining neutral wires that suppresses damage and deformation of the neutral wire busbar even when the neutral wire busbar is clamped with multiple clamping devices. [Solution] The present disclosure is a method for joining neutral wires, wherein the first U-phase neutral wire 22U1 and the neutral wire busbar 30 are clamped by a first clamping device, the first V-phase neutral wire 22V1 and the neutral wire busbar 30 are clamped by a second clamping device, and the first W-phase neutral wire 22W1 and the neutral wire busbar 30 are clamped by a third clamping device, and the first U-phase neutral wire 22U1, the first V-phase neutral wire 22V1, and the first W-phase neutral wire 22W1 are joined to the neutral wire busbar 30 by welding, the method comprising the step of positioning the neutral wire busbar 30 by providing a predetermined gap between the reference jig branch section 53 and the support jig 55 and the neutral wire busbar 30.

Description

Technical Field

[0001] The present disclosure relates to a method for joining neutral lines.

Background Art

[0002] Patent Document 1 discloses a method for manufacturing a stator including a plurality of clamping devices that clamp the tips of two legs of a segment coil together.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When clamping a neutral line busbar with a plurality of clamping devices, the internal stress of the neutral line busbar increases, and there is a possibility that the neutral line busbar may be damaged or deformed. The present disclosure solves such problems and provides a method for joining neutral lines that suppresses damage and deformation of the neutral line busbar even when the neutral line busbar is clamped with a plurality of clamping devices.

Means for Solving the Problems

[0005] This disclosure comprises a neutral wire busbar that connects to the U-phase neutral wire, V-phase neutral wire, and W-phase neutral wire of a stator coil; a jig for positioning the neutral wire busbar when connecting the U-phase neutral wire, V-phase neutral wire, and W-phase neutral wire of the stator coil to the neutral wire busbar; a first clamping device for clamping the U-phase neutral wire of the stator coil to the neutral wire busbar; a second clamping device for clamping the V-phase neutral wire of the stator coil to the neutral wire busbar; and a third clamping device for clamping the W-phase neutral wire of the stator coil to the neutral wire busbar. A method for joining neutral wires, comprising the following steps: clamping the U-phase neutral wire and the neutral wire busbar of the stator coil with a first clamping device, clamping the V-phase neutral wire and the neutral wire busbar of the stator coil with a second clamping device, and clamping the W-phase neutral wire and the neutral wire busbar of the stator coil with a third clamping device, and then welding the U-phase neutral wire, V-phase neutral wire, and W-phase neutral wire of the stator coil to the neutral wire busbar, wherein the jig includes a step of positioning the neutral wire busbar by providing a predetermined gap between it and the neutral wire busbar. This configuration suppresses damage and deformation of the neutral wire busbar.

[0006] The process includes clamping the U-phase neutral wire of the stator coil and the neutral wire busbar with the first clamping device, then clamping the V-phase neutral wire of the stator coil and the neutral wire busbar with the second clamping device, and then clamping the W-phase neutral wire of the stator coil and the neutral wire busbar with the third clamping device. This configuration suppresses damage and deformation of the neutral wire busbar.

[0007] The neutral wire busbar has a U-phase connection portion that connects to the U-phase neutral wire of the stator coil, a V-phase connection portion that connects to the V-phase neutral wire of the stator coil, and a W-phase connection portion that connects to the W-phase neutral wire of the stator coil. The U-phase connection portion, V-phase connection portion, and W-phase connection portion of the neutral wire busbar are arranged along the length of the neutral wire busbar in the order of the V-phase connection portion, the U-phase connection portion, and the W-phase connection portion. This configuration suppresses damage and deformation of the neutral wire busbar.

[0008] The stator coil's U-phase neutral wire has a first U-phase neutral wire and a second U-phase neutral wire, the stator coil's V-phase neutral wire has a first V-phase neutral wire and a second V-phase neutral wire, and the stator coil's W-phase neutral wire has a first W-phase neutral wire and a second W-phase neutral wire. The process includes welding the first U-phase neutral wire, the first V-phase neutral wire, and the first W-phase neutral wire of the stator coil to the neutral wire busbar, removing the jig from the neutral wire busbar, and welding the second U-phase neutral wire, the second V-phase neutral wire, and the second W-phase neutral wire of the stator coil to the neutral wire busbar. This configuration allows for an increase in the ratio of processing time to production time. [Effects of the Invention]

[0009] This disclosure provides a method for joining neutral wires that suppresses damage and deformation of the neutral wire busbar even when the neutral wire busbar is clamped by multiple clamping devices. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic plan view of the stator showing how the neutral wire busbar is positioned using a jig. [Figure 2] This diagram shows how a clamping device clamps the first U-phase neutral wire, the first V-phase neutral wire, and the first W-phase neutral wire and neutral wire busbar of the stator coil. [Figure 3] This is a schematic diagram of a stator coil. [Figure 4] This is a schematic diagram of the positioning reference unit and its surrounding area, viewed from the direction shown in IV of Figure 1. [Figure 5] This is a schematic plan view of the area near the notch at the branching section of the standard jig. [Figure 6] This is a schematic diagram of the configuration near the notch of the branching section of the standard jig, viewed from the direction shown in VI of Figure 5. [Figure 7] This is a schematic plan view of the area near the notch of the support jig. [Figure 8] This is a schematic diagram of the support jig's vicinity near the notch, viewed from the direction shown in VIII of Figure 7. [Figure 9] This diagram shows how a clamping device clamps the 2U-phase neutral wire, 2V-phase neutral wire, and 2W-phase neutral wire and neutral wire busbar of the stator coil. [Modes for carrying out the invention]

[0011] The embodiments of this disclosure will be described below with reference to Figures 1 to 9. Figure 1 is a schematic plan view of a stator showing how the neutral wire busbar is positioned by a jig. Figure 2 is a diagram showing how the first U-phase neutral wire, first V-phase neutral wire, and first W-phase neutral wire of the stator coil and the neutral wire busbar are clamped by a clamping device. Figure 3 is a schematic diagram of the stator coil. Figure 4 is a schematic configuration diagram of the positioning reference section and its surroundings as seen from the direction shown in IV of Figure 1. Figure 5 is a partial schematic plan view of the area near the notch of the reference jig branch section. Figure 6 is a schematic configuration diagram of the area near the notch of the reference jig branch section as seen from the direction shown in VI of Figure 5. Figure 7 is a partial schematic plan view of the area near the notch of the support jig. Figure 8 is a schematic configuration diagram of the area near the notch of the support jig as seen from the direction shown in VIII of Figure 7. Figure 9 shows how the clamping device clamps the second U-phase neutral wire, the second V-phase neutral wire, and the second W-phase neutral wire and neutral wire busbar of the stator coil. In the following description, the axial, radial, and circumferential directions of the stator 10 will be referred to as the Z-direction, R-direction, and C-direction, respectively (see Figure 2).

[0012] First, using Figures 1 to 3, the stator 10 to which the neutral wire is joined by the neutral wire joining method according to this disclosure will be explained. The stator 10, in combination with a rotor (not shown), constitutes a rotating electric machine. A rotating electric machine is a rotating electrical machine that has the functions of both an electric motor and a generator, and is mounted on vehicles such as electric vehicles, hybrid vehicles, and fuel cell vehicles; it is a so-called motor generator.

[0013] As shown in FIGS. 1 and 2, the stator 10 has a stator core 11, a stator coil 20, and a neutral bus bar 30. The stator core 11 is formed in a substantially cylindrical shape, and a plurality of substantially annular electromagnetic steel sheets are laminated in the axial direction (the depth direction of the paper surface of FIG. 1). Each electromagnetic steel sheet constituting the stator core 11 has substantially the same shape and is formed by punching or the like. The stator core 11 has an annular yoke 12 extending along the circumferential direction (direction C in FIG. 1), a plurality of teeth 13 protruding radially inward (direction R in FIG. 1) from the inner peripheral surface of the yoke 12, and a plurality of slots 14 formed between the teeth.

[0014] The stator coil 20 is wound around the stator core 11. The stator coil 20 is formed by electrically connecting a plurality of segment coils 21 inserted into the slots 14. Note that the stator coil 20 is disposed along the entire slot 14 in the radial direction (direction R in FIG. 1) of the stator core 11, but only a part of the stator coil 20 is shown in FIG. 1.

[0015] The segment coil 21 is an electrical conductor formed by bending a flat wire having an insulating film formed on the surface thereof, made of, for example, an enamel resin or the like, into a substantially U shape. The segment coil 21 has two (a pair) legs, and at the tip of each leg, the insulating film is removed and the conductor is exposed. The tip of the leg of the segment coil 21 is electrically connected to the tip of the leg of another segment coil 21 by welding. Thereby, the stator coil 20 is wound around the stator core 11.

[0016] As shown in FIG. 3, the stator coil 20 includes a U-phase stator coil 20U, a V-phase stator coil 20V, and a W-phase stator coil 20W. The U-phase stator coil 20U, the V-phase stator coil 20V, and the W-phase stator coil 20W are connected by a double-star connection (2Y connection). Note that the stator coil 20 may also be connected by a single-star connection.

[0017] The U-phase stator coil 20U is composed of the first coil 20U1 and the second coil 20U2 connected in parallel. The first coil 20U1 and the second coil 20U2 respectively have a first U-phase lead wire 23U1, a second U-phase lead wire 23U2, a first U-phase neutral wire 22U1, and a second U-phase neutral wire 22U2 formed by one leg of the segment coil 21. The first U-phase lead wire 23U1 and the second U-phase lead wire 23U2 are respectively formed at one end side of the first coil 20U1 and the second coil 20U2 and are connected to the input terminal 25U. The input terminal 25U is connected to a power line that supplies power from the outside. The first U-phase neutral wire 22U1 and the second U-phase neutral wire 22U2 are respectively formed at the other end side of the first coil 20U1 and the second coil 20U2 and are connected to the neutral bus bar 30.

[0018] The V-phase stator coil 20V is composed of the first coil 20V1 and the second coil 20V2 connected in parallel. The first coil 20V1 and the second coil 20V2 respectively have a first V-phase lead wire 23V1, a second V-phase lead wire 23V2, a first V-phase neutral wire 22V1, and a second V-phase neutral wire 22V2 formed by one leg of the segment coil 21. The first V-phase lead wire 23V1 and the second V-phase lead wire 23V2 are respectively formed at one end side of the first coil 20V1 and the second coil 20V2 and are connected to the input terminal 25V. The input terminal 25V is connected to a power line that supplies power from the outside. The first V-phase neutral wire 22V1 and the second V-phase neutral wire 22V2 are respectively formed at the other end side of the first coil 20V1 and the second coil 20V2 and are connected to the neutral bus bar 30.

[0019] The W-phase stator coil 20W consists of a first coil 20W1 and a second coil 20W2 connected in parallel. The first coil 20W1 and the second coil 20W2 each have a first W-phase lead wire 23W1 and a second W-phase lead wire 23W2, and a first W-phase neutral wire 22W1 and a second W-phase neutral wire 22W2, respectively, formed by one leg of the segment coil 21. The first W-phase lead wire 23W1 and the second W-phase lead wire 23W2 are formed on one end of the first coil 20W1 and the second coil 20W2, respectively, and are connected to the input terminal 25W. The input terminal 25W is connected to a power line that supplies power from an external source. The first W-phase neutral wire 22W1 and the second W-phase neutral wire 22W2 are formed on the other end of the first coil 20W1 and the second coil 20W2, respectively, and are connected to the neutral wire busbar 30.

[0020] As shown in Figures 1 and 2, the first U-phase neutral wire 22U1, the second U-phase neutral wire 22U2, the first V-phase neutral wire 22V1, the second V-phase neutral wire 22V2, the first W-phase neutral wire 22W1, and the second W-phase neutral wire 22W2 protrude outward from the axial end face of the stator core 11 (towards the front of the paper in Figure 1, and towards the Z-axis in Figure 2). The first U-phase neutral wire 22U1, the second U-phase neutral wire 22U2, the first V-phase neutral wire 22V1, the second V-phase neutral wire 22V2, the first W-phase neutral wire 22W1, and the second W-phase neutral wire 22W2 are arranged in a line along the circumferential direction of the stator core 11 at predetermined intervals, and are arranged in the order of second V-phase neutral wire 22V2, first V-phase neutral wire 22V1, second U-phase neutral wire 22U2, first U-phase neutral wire 22U1, second W-phase neutral wire 22W2, and first W-phase neutral wire 22W1 from one side to the other in the circumferential direction of the stator core 11 (from the top to the bottom in Figure 1).

[0021] As shown in Figures 1 and 2, the neutral wire busbar 30 is formed from a flat metal member and has a substantially arc shape. The neutral wire busbar 30 is arranged to extend along the circumferential direction (direction C in Figure 1) of the stator core 11. The neutral wire busbar 30 has a busbar body portion 31 and a first U-phase connection portion 32U1, a second U-phase connection portion 32U2, a first V-phase connection portion 32V1, a second V-phase connection portion 32V2, a first W-phase connection portion 32W1, and a second W-phase connection portion 32W2.

[0022] The busbar body 31 functions as the neutral point of the stator coil 20 by connecting the neutral wires of the U-phase stator coil 20U, V-phase stator coil 20V, and W-phase stator coil 20W to the neutral wire busbar 30.

[0023] The first U-phase connection section 32U1, the second U-phase connection section 32U2, the first V-phase connection section 32V1, the second V-phase connection section 32V2, the first W-phase connection section 32W1, and the second W-phase connection section 32W2 are provided at predetermined intervals on the busbar body 31 along the length direction of the neutral wire busbar 30, and are arranged in the order of second V-phase connection section 32V2, first V-phase connection section 32V1, second U-phase connection section 32U2, first U-phase connection section 32U1, second W-phase connection section 32W2, and first W-phase connection section 32W1 from one side to the other in the circumferential direction of the stator core 11 (from the top to the bottom in Figure 1). The first U-phase connection portion 32U1, the second U-phase connection portion 32U2, the first V-phase connection portion 32V1, the second V-phase connection portion 32V2, the first W-phase connection portion 32W1, and the second W-phase connection portion 32W2 extend radially (in the R direction in Figure 2) inward from the busbar body portion 31 to the stator core 11, and then are bent at approximately a right angle to extend in the axial direction (in the Z direction in Figure 2) of the stator core 11, away from the stator core 11.

[0024] The first U-phase connection section 32U1 and the second U-phase connection section 32U2 are connected to the first U-phase neutral wire 22U1 and the second U-phase neutral wire 22U2 of the U-phase stator coil 20U, respectively, on the radially (R-direction in Figure 1) outer side of the stator core 11. The first V-phase connection section 32V1 and the second V-phase connection section 32V2 are connected to the first V-phase neutral wire 22V1 and the second V-phase neutral wire 22V2 of the V-phase stator coil 20V, respectively, on the radially (R-direction in Figure 1) outer side of the stator core 11. The first W-phase connection section 32W1 and the second W-phase connection section 32W2 are connected to the first W-phase neutral wire 22W1 and the second W-phase neutral wire 22W2 of the W-phase stator coil 20W, respectively, on the radially (R-direction in Figure 1) outer side of the stator core 11.

[0025] As shown in Figure 1, a recess 33 is provided between the first U-phase connection portion 32U1 and the second W-phase connection portion 32W2 of the neutral wire busbar 30, recessed radially (R-direction in Figure 1) outward from the stator core 11. Furthermore, a first end portion 34, which is L-shaped in plan view, is provided at the end of the neutral wire busbar 30 on the first W-phase connection portion 32W1 side. Additionally, a second end portion 35, also L-shaped in plan view, is provided at the end of the neutral wire busbar 30 on the second V-phase connection portion 32V2 side. The recess 33, the first end portion 34, and the second end portion 35 are used for positioning the neutral wire busbar 30, and further details will be described later.

[0026] A thermistor unit 40 is attached to the neutral busbar 30 to determine the temperature of the neutral busbar 30 and the temperature of the stator coil 20.

[0027] Next, we will explain how to connect the neutral wires of the U-phase stator coil 20U, the V-phase stator coil 20V, and the W-phase stator coil 20W to the neutral wire busbar 30. The joining method is carried out by the following steps (1) to (6). (1) The neutral wire busbar 30 is positioned using the jig 50. (2) The first clamping device 60, the second clamping device 70, and the third clamping device 80 clamp the first U-phase neutral wire 22U1, the first V-phase neutral wire 22V1, and the first W-phase neutral wire 22W1 of the stator coil 20 to the neutral wire busbar 30. (3) The first U-phase neutral wire 22U1, the first V-phase neutral wire 22V1, and the first W-phase neutral wire 22W1 are joined to the neutral wire busbar 30 by welding. (4) Remove the jig 50 from the neutral busbar 30. (5) The first clamping device 60, the second clamping device 70, and the third clamping device 80 clamp the second U-phase neutral wire 22U2, the second V-phase neutral wire 22V2, and the second W-phase neutral wire 22W2 of the stator coil 20 to the neutral wire busbar 30. (6) The second U-phase neutral wire 22U2, the second V-phase neutral wire 22V2, and the second W-phase neutral wire 22W2 are joined to the neutral wire busbar 30 by welding.

[0028] First, the process of (1) positioning the neutral wire busbar 30 with the jig 50 will be explained using Figures 1 and 4 to 8. As shown in Figure 1, the jig 50 for positioning the neutral wire busbar 30 has a reference jig 51 and a support jig 55. The reference jig 51 has a reference jig body 52 and a reference jig branch 53.

[0029] The main body portion 52 of the reference jig has a rectangular cross-section and is roughly shaped like a rectangular parallelepiped, extending in the radial direction (direction R in Figure 1) of the stator core 11. The branch portion 53 of the reference jig has a rectangular cross-section and is formed in an L-shape in plan view of the stator core 11. The branch portion 53 of the reference jig extends from the longitudinal center of the main body portion 52 of the reference jig in the circumferential direction (direction C in Figure 1) of the stator core 11, and then is bent at approximately a right angle and extends in a direction approaching the stator core 11.

[0030] A notch 52a is provided at the tip of the reference jig body 52 on the radially inner side of the stator core 11 (left side in Figure 1). The notch 52a is a portion cut out by a predetermined length from the radially inner end of the stator core 11 (left side in Figure 1) to the radially outer side of the stator core 11 (right side in Figure 1) on the axially outer side of the reference jig body 52 of the stator core 11 (foreground side in Figure 1).

[0031] The main body of the reference jig 52 has a side surface 52b and a bottom surface 52c formed on the radially inward side of the stator core 11 (left side in Figure 1). The side surface 52b faces the radially inward side of the stator core 11 (left side in Figure 1) and constitutes one surface of the radially outward side of the notch 52a (right side in Figure 1). The bottom surface 52c faces the axially outward side of the stator core 11 (front side in Figure 1) and constitutes one surface of the axially inward side of the notch 52a (back side in Figure 1).

[0032] The reference jig body 52 is provided with a positioning reference portion 52d. The positioning reference portion 52d is formed by a roughly rectangular prism-shaped protrusion that extends from the bottom surface portion 52c outward in the axial direction of the stator core 11 (towards the foreground in Figure 1). In other words, the positioning reference portion 52d is formed in part of the space created by the notch portion 52a. The positioning reference portion 52d is located at the radially inner end of the reference jig body 52 of the stator core 11 (left side in Figure 1), and is provided in the center of the circumferential direction (direction C in Figure 1) of the stator core 11.

[0033] The peripheral portion of the recess 33 of the neutral wire busbar 30 fits into the notch 52a, and the positioning reference portion 52d is fitted into the recessed portion of the recess 33. As shown in Figure 4, a predetermined gap G12 is provided between the recess 33 and the positioning reference portion 52d in the circumferential direction of the stator core 11 (direction C in Figure 4). Although not shown, a predetermined gap G11 is also provided between the recess 33 and the positioning reference portion 52d in the radial direction of the stator core 11 (depth direction in Figure 4). These gaps G11 and G12 are formed to fit the positioning reference portion 52d into the recessed portion of the recess 33. The neutral wire busbar 30 and the bottom surface portion 52c are in contact in the axial direction of the stator core 11 (direction Z in Figure 4).

[0034] As shown in Figure 1, a notch 53a is provided at the tip of the reference jig branch 53 on the radially inner side of the stator core 11 (left side in Figure 1). The notch 53a is on the axially outer side of the reference jig branch 53 of the stator core 11 (front side of the paper in Figure 1), and is a portion cut out by a predetermined length from the longitudinal end of the reference jig branch 53 toward the radially outer side of the stator core 11 (lower right side in Figure 1), and from the end of the reference jig branch 53 toward the reference jig body 52 side (upper side in Figure 1), toward the opposite side of the reference jig body 52 in the circumferential direction of the stator core 11 (lower left side in Figure 1).

[0035] The reference jig branch portion 53 has a first side portion 53b, a second side portion 53c, and a bottom portion 53d formed on the radially inward side of the stator core 11 (left side in Figure 1). The first side portion 53b is a surface facing the radially inward side of the stator core 11 (upper left side in Figure 1) and constitutes one surface of the notch portion 53a on the radially outward side of the stator core 11 (lower right side in Figure 1). The second side portion 53c is a surface facing the reference jig body portion 52 side in the circumferential direction of the stator core 11 (upper right side in Figure 1) and constitutes one surface of the notch portion 53a on the opposite side from the reference jig body portion 52 in the circumferential direction of the stator core 11 (lower left side in Figure 1). The bottom portion 53d is a surface facing the axially outward side of the stator core 11 (front side in Figure 1) and constitutes one surface of the notch portion 53a on the axially inward side of the stator core 11 (back side in Figure 1).

[0036] The first end 34 of the neutral wire busbar 30 fits into the notch 53a. As shown in Figure 5, a predetermined gap G21 is provided between the first end 34 and the first side surface 53b in the radial direction (R direction in Figure 5) of the stator core 11. As shown in Figures 5 and 6, a predetermined gap G22 is provided between the first end 34 and the second side surface 53c in the circumferential direction (C direction in Figure 5) of the stator core 11. As shown in Figure 6, a predetermined gap G23 is provided between the first end 34 and the bottom surface 53d in the axial direction (Z direction in Figure 6) of the stator core 11.

[0037] As shown in Figure 1, the support jig 55 has a roughly rectangular cross-section and is in the shape of a rectangular parallelepiped, extending in a direction inclined in the circumferential direction (direction C in Figure 1) with respect to the radial direction (direction R in Figure 1) of the stator core 11. As shown in Figure 1, a notch 55a is provided at the tip of the support jig 55 on the neutral wire busbar 30 side (lower side in Figure 1).

[0038] The notch 55a is located on the outer side of the support jig 55 in the axial direction of the stator core 11 (the front side of the paper in Figure 1), and is a portion cut out by a predetermined length from the end of the support jig 55 on the inner side of the support jig 55 in the radial direction of the stator core 11 (lower left side in Figure 1) to the outer side of the support jig 55 in the radial direction of the stator core 11 (upper right side in Figure 1), and from the end of the support jig 55 on the side of the reference jig body 52 in the circumferential direction of the stator core 11 (lower right side in Figure 1) to the opposite side from the reference jig body 52 in the circumferential direction of the stator core 11 (upper left side in Figure 1).

[0039] The end of the support jig 55 on the neutral wire busbar 30 side (lower side in Figure 1) has a first side portion 55b, a second side portion 55c, and a bottom portion 55d. The first side portion 55b is a surface facing the radially inward side of the stator core 11 (lower left side in Figure 1) and constitutes one surface of the notch portion 55a facing radially outward (upper right side in Figure 1) of the stator core 11. The second side portion 55c is a surface facing the reference jig body portion 52 side (lower right side in Figure 1) in the circumferential direction of the stator core 11 and constitutes one surface of the notch portion 55a opposite to the reference jig body portion 52 in the circumferential direction of the stator core 11 (upper left side in Figure 1). The bottom portion 55d is a surface facing the axially outward side of the stator core 11 (front side in Figure 1) and constitutes one surface of the notch portion 55a facing axially inward (back side in Figure 1).

[0040] The second end 35 of the neutral busbar 30 fits into the notch 55a. As shown in Figure 7, a predetermined gap G31 is provided between the second end 35 and the first side surface 55b in the radial direction (R direction in Figure 7) of the stator core 11. As shown in Figures 7 and 8, a predetermined gap G32 is provided between the second end 35 and the second side surface 55c in the circumferential direction (C direction in Figure 7) of the stator core 11. As shown in Figure 8, a predetermined gap G33 is provided between the second end 35 and the bottom surface 55d in the axial direction (Z direction in Figure 8) of the stator core 11.

[0041] Next, using Figure 2, the process of clamping the first U-phase neutral wire 22U1, the first V-phase neutral wire 22V1, and the first W-phase neutral wire 22W1 of the stator coil 20 to the neutral wire busbar 30 using the first clamping device 60, the second clamping device 70, and the third clamping device 80 will be explained. First, the clamping of the first U-phase neutral wire 22U1 of the U-phase stator coil 20U to the first U-phase connection portion 32U1 of the neutral wire busbar 30 by the first clamping device 60 will be explained.

[0042] The first clamping device 60 has a movable part 61 and a fixed part 62. The movable part 61 extends in the radial direction of the stator core 11 (direction R in Figure 2), and the fixed part 62 is positioned in a through hole formed on the radial side of the stator core 11, extending in the axial direction of the stator core 11 (direction Z in Figure 2). Between the radial side end of the fixed part 62 and the radial side end of the movable part 61, there is a through part 63 formed by a through hole in the axial direction of the stator core 11. The first U-phase neutral wire 22U1 of the U-phase stator coil 20U and the first U-phase connection part 32U1 of the neutral wire busbar 30 are inserted into the through part 63. With the first U-phase neutral wire 22U1 and the first U-phase connection part 32U1 inserted into the through-hole 63, the movable part 61 is pulled radially outward from the stator core 11 by an actuator (not shown), thereby clamping the first U-phase neutral wire 22U1 and the first U-phase connection part 32U1.

[0043] Next, using Figure 2, we will explain how the second clamping device 70 clamps the first V-phase neutral wire 22V1 of the V-phase stator coil 20V and the first V-phase connection part 32V1 of the neutral wire busbar 30. The second clamping device 70 has a movable part 71, a fixed part 72, and a through part 73. Since the structure and function of these movable part 71, fixed part 72, and through part 73 are the same as the movable part 61, fixed part 62, and through part 63 of the first clamping device 60, we will omit their explanation. The second clamping device 70 clamps the first V-phase neutral wire 22V1 and the first V-phase connection part 32V1.

[0044] Next, using Figure 2, we will explain how the third clamping device 80 clamps the first W-phase neutral wire 22W1 of the W-phase stator coil 20W and the first W-phase connection portion 32W1 of the neutral wire busbar 30. The third clamping device 80 has a movable part 81, a fixed part 82, and a through part 83. Since the structure and function of these movable part 81, fixed part 82, and through part 83 are the same as the movable part 61, fixed part 62, and through part 63 of the first clamping device 60, we will omit their explanation. The third clamping device 80 clamps the first W-phase neutral wire 22W1 and the first W-phase connection portion 32W1.

[0045] The clamping by the first clamping device 60, the second clamping device 70, and the third clamping device 80 is not performed simultaneously, but in a predetermined order. Specifically, first, the first clamping device 60 clamps the first U-phase neutral wire 22U1 and the first U-phase connection part 32U1. Next, the second clamping device 70 clamps the first V-phase neutral wire 22V1 and the first V-phase connection part 32V1. Finally, the third clamping device 80 clamps the first W-phase neutral wire 22W1 and the first W-phase connection part 32W1.

[0046] Next, using Figure 2, we will explain the process of welding together (3) the first U-phase neutral wire 22U1, the first V-phase neutral wire 22V1, and the first W-phase neutral wire 22W1 with the neutral wire busbar 30. First, we will explain the welding process between the first U-phase neutral wire 22U1 of the U-phase stator coil 20U and the first U-phase connection portion 32U1 of the neutral wire busbar 30.

[0047] The first clamping device 60 is connected to the positive side of a welding power supply (not shown) and functions as an electrode. Above the first clamping device 60, a torch electrode (not shown) is positioned, connected to the negative side of the welding power supply. By bringing the torch electrode close to the penetration portion 63 of the first clamping device 60 and generating a high-temperature arc from the torch electrode, the first U-phase neutral wire 22U1 and the first U-phase connection portion 32U1 are melted and joined together.

[0048] Next, using Figure 2, the welding joint between the first V-phase neutral wire 22V1 of the V-phase stator coil 20V and the first V-phase connection portion 32V1 of the neutral wire busbar 30 will be explained. The second clamping device 70 is connected to the positive side of a welding power supply (not shown) and functions as an electrode. Above the second clamping device 70, a torch electrode (not shown) is positioned, connected to the negative side of the welding power supply. By bringing the torch electrode close to the penetration portion 73 of the second clamping device 70 and generating a high-temperature arc from the torch electrode, the first V-phase neutral wire 22V1 and the first V-phase connection portion 32V1 are melted and joined together.

[0049] Next, using Figure 2, the welding joint between the first W-phase neutral wire 22W1 of the W-phase stator coil 20W and the first W-phase connection portion 32W1 of the neutral wire busbar 30 will be explained. The third clamping device 80 is connected to the positive side of a welding power supply (not shown) and functions as an electrode. Above the third clamping device 80, a torch electrode (not shown) is positioned, connected to the negative side of the welding power supply. By bringing the torch electrode close to the penetration portion 83 of the third clamping device 80 and generating a high-temperature arc from the torch electrode, the first W-phase neutral wire 22W1 and the first W-phase connection portion 32W1 are melted and joined together.

[0050] Next, (4) remove the jig 50 from the neutral busbar 30. Also, release the clamps from the first clamping device 60, the second clamping device 70, and the third clamping device 80.

[0051] Next, using Figure 9, the process of clamping the second U-phase neutral wire 22U2, the second V-phase neutral wire 22V2, and the second W-phase neutral wire 22W2 of the stator coil 20 to the neutral wire busbar 30 using the first clamping device 60, the second clamping device 70, and the third clamping device 80 will be explained.

[0052] First, as shown in Figure 9, the first clamping device 60 clamps the second U-phase neutral wire 22U2 of the U-phase stator coil 20U and the second U-phase connection portion 32U2 of the neutral wire busbar 30. This clamping is the same as the clamping of the first U-phase neutral wire 22U1 and the first U-phase connection portion 32U1 by the first clamping device 60, so no explanation is given.

[0053] Next, as shown in Figure 9, the second clamping device 70 clamps the second V-phase neutral wire 22V2 of the V-phase stator coil 20V and the second V-phase connection part 32V2 of the neutral wire busbar 30. This clamping is the same as the clamping of the first V-phase neutral wire 22V1 and the first V-phase connection part 32V1 by the second clamping device 70, so no explanation is given.

[0054] Next, as shown in Figure 9, the third clamping device 80 clamps the second W-phase neutral wire 22W2 of the W-phase stator coil 20W and the second W-phase connection portion 32W2 of the neutral wire busbar 30. This clamping is the same as the clamping of the first W-phase neutral wire 22W1 and the first W-phase connection portion 32W1 by the third clamping device 80, so no explanation is provided.

[0055] Next, (6) the process of joining the second U-phase neutral wire 22U2, the second V-phase neutral wire 22V2, and the second W-phase neutral wire 22W2 to the neutral wire busbar 30 by welding will be explained.

[0056] First, the second U-phase neutral wire 22U2 of the U-phase stator coil 20U and the second U-phase connection portion 32U2 of the neutral wire busbar 30 are joined by welding. This welding is the same as the welding of the first U-phase neutral wire 22U1 and the first U-phase connection portion 32U1, so the explanation is omitted.

[0057] Next, the second V-phase neutral wire 22V2 of the V-phase stator coil 20V and the second V-phase connection part 32V2 of the neutral wire busbar 30 are joined by welding. This welding is the same as the welding of the first V-phase neutral wire 22V1 and the first V-phase connection part 32V1, so the explanation is omitted.

[0058] Next, the second W-phase neutral wire 22W2 of the W-phase stator coil 20W and the second W-phase connection part 32W2 of the neutral wire busbar 30 are joined by welding. This welding is the same as the welding of the first W-phase neutral wire 22W1 and the first W-phase connection part 32W1, so the explanation is omitted.

[0059] This disclosure provides a jig 50 for positioning the neutral wire busbar 30 when joining the first U-phase neutral wire 22U1, the first V-phase neutral wire 22V1, and the first W-phase neutral wire 22W1 of the stator coil 20 to the neutral wire busbar 30. Furthermore, the first U-phase neutral wire 22U1 and the neutral wire busbar 30 are clamped by a first clamping device 60, the first V-phase neutral wire 22V1 and the neutral wire busbar 30 are clamped by a second clamping device 70, and the first W-phase neutral wire 22W1 and the neutral wire busbar 30 are clamped by a third clamping device 80, and then the first U-phase neutral wire 22U1, the first V-phase neutral wire 22V1, and the first W-phase neutral wire 22W1 to the neutral wire busbar 30 are joined by welding. The jig 50 then positions the neutral wire busbar 30 by providing a predetermined gap between itself and the neutral wire busbar 30.

[0060] When the neutral wire and neutral wire busbar of the stator coil are clamped by multiple clamping devices, the internal stress on the neutral wire busbar increases, potentially causing damage or deformation to the neutral wire busbar. Specifically, when clamping with the second clamping device 70, a force acts on the movable part 71 pulling it outward in the radial direction of the stator core 11 (direction R in Figure 2). As a result, a force acts on the vicinity of the second end 35 of the neutral wire busbar 30, causing twisting and rotation in the horizontal direction (direction R or C in Figure 2). Furthermore, when clamping with the third clamping device 80, a force acts on the movable part 81 pulling it outward in the radial direction of the stator core 11. As a result, a force acts on the vicinity of the first end 34 of the neutral wire busbar 30, causing twisting and rotation in the horizontal direction (direction R or C in Figure 2).

[0061] In contrast, this disclosure provides a predetermined gap between the jig 50 and the neutral wire busbar 30. Specifically, as shown in Figures 5 and 6, predetermined gaps G21, G22, and G23 are provided between the first end 34 of the neutral wire busbar 30 and the reference jig branch 53 in the radial, circumferential, and axial directions of the stator core 11, respectively. Also, as shown in Figures 7 and 8, predetermined gaps G31, G32, and G33 are provided between the second end 35 of the neutral wire busbar 30 and the support jig 55 in the radial, circumferential, and axial directions of the stator core 11, respectively.

[0062] By providing such gaps, the forces acting on the neutral wire busbar 30 can be relieved, preventing the internal stress of the neutral wire busbar 30 from increasing and suppressing damage and deformation of the neutral wire busbar 30. The number and location of the gaps between the jig 50 and the neutral wire busbar 30 may be changed as appropriate.

[0063] Furthermore, in this disclosure, first, the first U-phase neutral wire 22U1 and the first U-phase connection part 32U1 are clamped by the first clamping device 60. Next, the first V-phase neutral wire 22V1 and the first V-phase connection part 32V1 are clamped by the second clamping device 70. Finally, the first W-phase neutral wire 22W1 and the first W-phase connection part 32W1 are clamped by the third clamping device 80.

[0064] Even if the clamping by the first clamping device 60, the second clamping device 70, and the third clamping device 80 is attempted to be performed simultaneously, the timing of clamping between the devices will be different due to manufacturing errors in the neutral wire busbar 30. Since this difference is not constant between products, the clamping order will differ between products, and ultimately, the shape of the neutral wire busbar 30 after joining will not be reproducible. Therefore, in this disclosure, the clamping by the first clamping device 60, the second clamping device 70, and the third clamping device 80 is performed in a predetermined order. Specifically, the first clamping device 60 is used first, followed by the second clamping device 70, and finally the third clamping device 80.

[0065] First, by clamping the first U-phase connection portion 32U1 located in the longitudinal center of the neutral busbar 30, displacement of the longitudinal end of the neutral busbar 30 can be suppressed. Furthermore, while the first U-phase connection portion 32U1 and the first W-phase connection portion 32W1 are supported at two points by the reference jig body portion 52 and the reference jig branch portion 53, the first U-phase connection portion 32U1 and the first V-phase connection portion 32V1 are supported at only one point by the support jig 55. Therefore, by clamping the first V-phase connection portion 32V1, which has fewer support points, second, displacement of the first V-phase connection portion 32V1 can be suppressed. By performing the clamping in this predetermined order, the amount of displacement of the neutral busbar 30 can be suppressed, and the reproducibility of the shape of the neutral busbar 30 after joining can be obtained.

[0066] This disclosure describes positioning the neutral wire busbar 30 with a jig 50 and welding the first U-phase neutral wire 22U1, first V-phase neutral wire 22V1, and first W-phase neutral wire 22W1 of the stator coil 20 to the neutral wire busbar 30. Then, after removing the jig 50 from the neutral wire busbar 30, welding the second U-phase neutral wire 22U2, second V-phase neutral wire 22V2, and second W-phase neutral wire 22W2 of the stator coil 20 to the neutral wire busbar 30.

[0067] After welding the first U-phase neutral wire 22U1, the first V-phase neutral wire 22V1, and the first W-phase neutral wire 22W1 to the neutral wire busbar 30, the position of the neutral wire busbar 30 is fixed. Therefore, the jig 50 can be removed from the neutral wire busbar 30, and the second U-phase neutral wire 22U2, the second V-phase neutral wire 22V2, and the second W-phase neutral wire 22W2 to the neutral wire busbar 30 can be welded. As a result, the ratio of processing time to production time (net processing time ratio) can be increased.

[0068] This disclosure is not limited to the embodiments described above, and may be modified as appropriate without departing from its spirit. [Explanation of Symbols]

[0069] 20. Stator coil 22U1...1st U phase neutral wire 22U2...2nd U phase neutral wire 22V1...1st V phase neutral wire 22V2...2nd V phase neutral wire 22W1...1st W phase neutral line 22W2...2nd W phase neutral line 30···Neutral line busbar 52...Reference jig main body 53...Standard jig branch section 55...Support jig 60...First clamping device 70...Second clamping device 80...Third clamping device

Claims

1. A neutral wire busbar that connects to the U-phase neutral wire, V-phase neutral wire, and W-phase neutral wire of the stator coil, A jig for positioning the neutral wire busbar when joining the U-phase neutral wire, V-phase neutral wire, and W-phase neutral wire of the stator coil to the neutral wire busbar, The system comprises a first clamping device for clamping the U-phase neutral wire of the stator coil and the neutral wire busbar, a second clamping device for clamping the V-phase neutral wire of the stator coil and the neutral wire busbar, and a third clamping device for clamping the W-phase neutral wire of the stator coil and the neutral wire busbar. A method for joining neutral wires, comprising: clamping the U-phase neutral wire and the neutral wire busbar of the stator coil with the first clamping device; clamping the V-phase neutral wire and the neutral wire busbar of the stator coil with the second clamping device; and clamping the W-phase neutral wire and the neutral wire busbar of the stator coil with the third clamping device, while welding the U-phase neutral wire, V-phase neutral wire, and W-phase neutral wire of the stator coil to the neutral wire busbar, The jig includes a step of positioning the neutral wire busbar by providing a predetermined gap between it and the neutral wire busbar. Method of joining the neutral wire.

2. The process includes the steps of clamping the U-phase neutral wire and the neutral wire busbar of the stator coil with the first clamping device, then clamping the V-phase neutral wire and the neutral wire busbar of the stator coil with the second clamping device, and then clamping the W-phase neutral wire and the neutral wire busbar of the stator coil with the third clamping device. The method for joining neutral wires according to claim 1.

3. The neutral busbar has a U-phase connection portion that connects to the U-phase neutral wire of the stator coil, a V-phase connection portion that connects to the V-phase neutral wire of the stator coil, and a W-phase connection portion that connects to the W-phase neutral wire of the stator coil. The U-phase connection portion, V-phase connection portion, and W-phase connection portion of the neutral busbar are arranged along the length of the neutral busbar in the order of the V-phase connection portion, the U-phase connection portion, and the W-phase connection portion. A method for joining neutral wires according to claim 1 or claim 2.

4. The stator coil's U-phase neutral wire has a first U-phase neutral wire and a second U-phase neutral wire. The V-phase neutral wire of the stator coil has a first V-phase neutral wire and a second V-phase neutral wire. The W-phase neutral wire of the stator coil has a first W-phase neutral wire and a second W-phase neutral wire. A step of joining the first U-phase neutral wire, the first V-phase neutral wire, and the first W-phase neutral wire of the stator coil to the neutral wire busbar by welding, The steps include removing the jig from the neutral wire busbar, The process includes welding together the second U-phase neutral wire, the second V-phase neutral wire, and the second W-phase neutral wire of the stator coil with the neutral wire busbar. The method for joining neutral wires according to claim 1.

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