WO2023054407A1

WO2023054407A1 - Stator manufacturing method

Info

Publication number: WO2023054407A1
Application number: PCT/JP2022/036034
Authority: WO
Inventors: 敬一伊藤
Original assignee: 日本発條株式会社
Priority date: 2021-09-29
Filing date: 2022-09-27
Publication date: 2023-04-06

Abstract

The present invention uniformly welds two coil ends to a busbar with one weld.　Provided is a stator manufacturing method in which two coil ends (181) that lead out from a coil (18) wrapped around teeth of a stator core are welded to a coil joining part (22U2) of a busbar (22U), so as to manufacture a stator. In this manufacturing method, when the two coil ends (181) are welded to the coil joining part (22U2) by generating an arc between one of the coil ends (181) and an electrode of an arc welding machine in a state where the two coil ends (181) which each extend in a first direction and are adjacent to each other in a second direction are placed in contact in a third direction with an end face of the coil joining part (22U2), the combined volume of the two coil ends (181) and the coil joining part (22U2) is set to be greater on one coil end (181) side than on the other coil end (181) side.

Description

Stator manufacturing method

The present invention relates to a method for manufacturing a stator.

Japanese Patent No. 5153167 discloses a winding connection device for a rotating machine provided with a connection member (bus bar) externally connected to a stator winding (coil) wound around a stator iron core of a stator. In this device, the connection members are provided with winding connection terminals for receiving the ends of the stator windings. The winding connection terminals are provided with a U-shaped groove that accommodates the stator windings between the main body and two corners extending from the main body. One end of the stator winding (coil end) is accommodated in this U-shaped groove, and the two corners are melted and welded by TIG welding. The winding connection terminals are formed so as to satisfy 1≤(T/S)≤3, where T is the total area of the two corners and S is the cross-sectional area of the stator winding. As a result, the winding connection terminal is formed into an optimum welding shape.

In the above prior art, one coil end is welded to the busbar, but there are cases where two coil ends are welded to the busbar. In this case, for example, two coil terminals are brought into contact with the bus bar by means of a jig, and arc welding is performed by aiming at one of the coil terminals. In this way, if one coil end is targeted, the one coil end is preferentially melted, and the other coil end may become insufficiently welded.

An object of the present invention is to provide a method of manufacturing a stator that can evenly weld two coil ends to a busbar in one welding operation.

A stator manufacturing method according to a first aspect of the present invention includes welding two coil ends derived from coils wound around teeth of a stator core to coil joints of a bus bar to manufacture a stator. wherein the two coil terminals each extending in a first direction and adjacent to each other in a second direction orthogonal to the first direction are arranged in the first direction and the An arc is generated between one of the coil terminals and an electrode of an arc welding machine while contacting in a third direction orthogonal to the second direction, and the two coil terminals are welded to the coil joint. In this case, the total volume of the two coil terminals and the coil joint is set larger on the one coil terminal side than on the other coil terminal side.

Note that, in the first aspect, the volume of the two coil terminals is defined by the portion of the two coil terminals that overlaps the coil joint when viewed from the third direction, and the tips of the two coil terminals that are larger than those portions. is the volume of the side part.

In the stator manufacturing method of the first aspect, the stator is manufactured by welding two coil ends derived from the coils wound around the teeth of the stator core to the coil joints of the busbar. In this manufacturing method, two coil ends each extending in a first direction and adjacent to each other in a second direction orthogonal to the first direction are arranged in the first direction and the second direction with respect to the end surface of the coil joint portion. is contacted in a third direction perpendicular to the . In this state, an arc is generated between one coil end and the electrode of the arc welder to weld the two coil ends to the coil joint. That is, arc welding is performed aiming at one coil end. In this welding, the total volume of the two coil ends and the coil joint is set larger on one coil end side than on the other coil end side. As a result, when arc welding is performed targeting one coil end, the heat capacities including the coil joint portion can be equalized between the one coil end side and the other coil end side. As a result, the two coil ends and the coil joint can be evenly melted on both sides, so that the two coil ends can be evenly welded to the busbar in one welding. .

In the method of manufacturing a stator according to the second aspect of the present invention, in the first aspect, the coil joints are formed in an asymmetrical shape in the second direction.

In the stator manufacturing method of the second aspect, the coil joints of the busbars are formed in an asymmetrical shape in the second direction. As a result, the volume of the coil joint can be set larger on one coil terminal side than on the other coil terminal side.

In the method of manufacturing a stator according to the third aspect of the present invention, in the second aspect, the coil joint portion is provided with an overhang portion that contacts the one coil end from the side opposite to the other coil end.

In the method of manufacturing a stator according to the third aspect, the coil joint portion is provided with an overhang portion that contacts one coil end from the side opposite to the other coil end. Thus, the coil joints of the busbar can be formed in an asymmetrical shape in the second direction, and the volume of the coil joints can be set larger on one coil terminal side than on the other coil terminal side.

A method of manufacturing a stator according to a fourth aspect of the present invention is a method of manufacturing a stator by welding two coil ends derived from coils wound around teeth of a stator core to coil joints of a bus bar. wherein the two coil terminals each extending in a first direction and adjacent to each other in a second direction orthogonal to the first direction are arranged in the first direction and the An arc is generated between one of the coil terminals and an electrode of an arc welder while the two coil terminals are in contact with each other using a jig in a third direction orthogonal to the second direction. When welding to the coil joints, the total volume of the two coil terminals, the coil joints and the jig is set larger on the one coil terminal side than on the other coil terminal side.

In the method for manufacturing a stator according to the fourth aspect, the stator is manufactured by welding two coil ends derived from coils wound around the teeth of the stator core to the coil joints of the busbar. In this manufacturing method, two coil ends each extending in a first direction and adjacent to each other in a second direction orthogonal to the first direction are arranged in the first direction and the second direction with respect to the end surface of the coil joint portion. is contacted using a jig in a third direction perpendicular to the . In this state, an arc is generated between one coil end and the electrode of the arc welder to weld the two coil ends to the coil joint. That is, arc welding is performed aiming at one coil end. During this welding, the total volume of the two coil ends, the coil joint and the jig is set larger on one coil end side than on the other coil end side. As a result, when arc welding is performed targeting one coil end, the heat capacities of the one coil end side and the other coil end side, including the coil joint portion and the jig, can be equalized. As a result, the two coil ends and the coil joint can be evenly melted on both sides, so that the two coil ends can be evenly welded to the busbar in one welding. .

As described above, in the stator manufacturing method according to the present invention, it is possible to evenly weld two coil ends to the busbar in one welding operation.

It is a perspective view which shows the state in the middle of manufacture of the stator which concerns on embodiment. FIG. 4 is a plan view showing a state in the middle of manufacturing the stator according to the embodiment; It is a perspective view which expands and shows a part of FIG. FIG. 3 is a plan view showing an enlarged part of FIG. 2; It is a perspective view showing a part of bus bar unit with which the stator concerning an embodiment is provided. FIG. 4 is a plan view showing a coil joint portion of a busbar and two coil terminals; FIG. 3 is a schematic diagram showing an arc welder used for welding a coil joint and two coil ends; FIG. 4 is a plan view showing a state in which a coil joint and two coil ends are welded; FIG. 4 is a side view showing a state in which a coil joint and two coil ends are welded; FIG. 8 is a plan view showing a coil joint portion of a busbar and two coil terminals according to a comparative example; FIG. 7 is a plan view showing a state in which a coil joint portion of a busbar and two coil ends are welded together according to a comparative example; FIG. 11 is a plan view showing a coil joint portion of a busbar and two coil terminals provided in a stator according to a first modified example; 13 is a side view showing the two coil terminals shown in FIG. 12 as viewed from the side; FIG. FIG. 11 is a plan view showing a coil joint portion of a busbar and two coil terminals included in a stator according to a second modified example; FIG. 15 is a side view showing the two coil terminals shown in FIG. 14 as viewed from the side; FIG. 11 is a plan view showing a coil joint portion of a busbar and two coil terminals provided in a stator according to a third modified example; 17 is a side view showing the configuration shown in FIG. 16 as viewed from the right side of FIG. 16; FIG. FIG. 11 is a plan view showing a coil joint portion of a busbar and two coil terminals provided in a stator according to a fourth modification; FIG. 19 is a side view showing the configuration shown in FIG. 18 as viewed from the right side of FIG. 18; FIG. 11 is a plan view showing a coil joint portion of a busbar and two coil terminals provided in a stator according to a fifth modified example; FIG. 11 is a plan view showing a coil joint portion of a busbar, two coil ends, and a jig provided in a stator according to a sixth modification;

A method of manufacturing a stator according to an embodiment of the present invention will be described below with reference to FIGS. In addition, in each figure, the scale of drawing is changed suitably. Also, in each drawing, some reference numerals may be omitted for the purpose of making the drawings easier to read.

FIGS. 1 and 2 show a state in the middle of manufacturing a stator 10 manufactured by the stator manufacturing method according to the present embodiment. First, the configuration of the stator 10 will be described. The stator 10 is an armature (stator) that includes a stator core 12 , a plurality of (here, 24) coils 18 , and a busbar unit 20 . The stator core 12 , multiple coils 18 and busbar unit 20 are housed in a cylindrical case 28 . A rotor (not shown) is arranged inside the stator 10 to constitute an inner rotor type motor (rotary electric machine). This motor is, for example, a three-phase motor.

The stator core 12 is constructed by laminating a plurality of iron core pieces made of electromagnetic steel sheets. The stator core 12 is formed in an annular shape and has a yoke 14 and a plurality of (here, 24) teeth 16 . The yoke 14 has a cylindrical shape. The plurality of teeth 16 are formed to protrude radially inward of the stator core 12 from the inner peripheral surface of the yoke 14 . A plurality of teeth 16 are formed side by side at regular intervals in the circumferential direction of the stator core 12 , and slots (reference numerals omitted) are formed between the plurality of teeth 16 . The stator 10 is fitted inside the case 28 . The numbers of poles and slots of the stator 10 shown in FIGS. 1 and 2 are merely examples, and are not limited to these.

The plurality of coils 18 are spirally wound around the plurality of teeth 16 respectively. An insulator such as an insulator, insulating paper, or varnish is interposed between each coil 18 and each tooth 16 . Each coil 18 is configured such that a wire made of, for example, copper, aluminum, silver, or an alloy wire thereof is coated with an insulating film such as enamel. Although the wire is a round wire here, it may be a rectangular wire, a hexagonal wire, or the like. When viewed from the radial direction of the stator core 12 , the coil 18 is wound in a substantially elongated rectangular shape whose longitudinal direction is the axial direction of the stator core 12 . In this embodiment, as an example, each coil 18 is configured by winding two electric wires. The two wires may be wound together or separately.

As shown in FIGS. 3 and 4, two coil terminals 181 as one end and two coil terminals 182 as the other end are led out from each coil 18 . In this embodiment, as an example, two coil terminals 181 and two coil terminals 182 are both led out to one side of the stator core 12 in the axial direction. The two coil terminals 181 are arranged on the root side of the teeth 16 , and the two coil terminals 182 are arranged on the tip side of the teeth 16 . The two coil ends 181 extend parallel to each other in the axial direction of the stator core 12 and are adjacent to each other (here, in contact) in the circumferential direction of the stator core 12 . Similarly, the two coil terminals 182 extend parallel to each other in the axial direction of the stator core 12 and are adjacent to each other in the circumferential direction of the stator core 12 (here, in contact with each other). The axial direction of the stator core 12 corresponds to the "first direction" of the invention, and the circumferential direction of the stator core 12 corresponds to the "second direction" of the invention. Note that the two coil ends 181 may be separated by up to about 10% or less of the coil diameter. The same is true for the two coil terminals 182 . Further, both of the

coil terminals

181 and 182 may be arranged close to the inner diameter or outer diameter of the stator core 12 , or the

coil terminals

181 and 182 may be separated vertically in the axial direction of the stator core 12 .

The plurality of coils 18 includes a plurality (eight in this case) of U-phase coils 18U, a plurality of (eight in this case) of V-phase coils 18V, and a plurality of (eight in this case) of W-phase coils 18W. ing. A U-phase coil 18U, a V-phase coil 18V, and a W-phase coil 18W are sequentially arranged along the circumferential direction of the stator core 12 . The U-phase coils 18U, the V-phase coils 18V, and the W-phase coils 18W are mounted on the teeth 16 of the stator core 12 at intervals in the circumferential direction of the stator core 12, respectively. Adjacent in-phase coils 18 (same phase among U-phase, V-phase, and W-phase) are electrically connected to each other by a busbar unit 20 .

As shown in FIGS. 1 to 4, the busbar unit 20 is arranged on one side of the stator core 12 in the axial direction. As shown in FIG. 5 , the busbar unit 20 includes a first busbar 22 , a second busbar 24 and an insulator 26 . Both the first bus bar 22 and the second bus bar 24 correspond to the "bus bar" in the present invention. The first busbar 22 is composed of a U-phase busbar 22U, a V-phase busbar 22V, and a W-phase busbar 22W. As an example, the second busbar 24 is composed of a plurality of (here, eight) busbar divisions 24S. The U-phase busbar 22U, the V-phase busbar 22V, the W-phase busbar 22W, and the busbar divisions 24S are manufactured by press-molding a metal plate as an example, but they are not limited to this. For example, like the coil 18, the U-phase busbar 22U, the V-phase busbar 22V, the W-phase busbar 22W, and the busbar divisions 24S may be made of round wire, rectangular wire, hexagonal wire, or the like. Also, the configuration of the busbar unit 20 is merely an example, and can be changed as appropriate.

The U-phase busbar 22U, the V-phase busbar 22V, and the W-phase busbar 22W respectively include first extending portions 22U1, 22V1, and 22W1 extending annularly along the yoke 14 in the circumferential direction of the stator core 12, and first extending portions 22U1, 22V1, and 22W1. It has a plurality of first coil joint portions 22U2, 22V2 and 22W2 extending from the portions 22U1, 22V1 and 22W1 to the root side of each tooth 16. As shown in FIG. All of the plurality of first coil junctions 22U2, 22V2, 22W2 correspond to "coil junctions" in the present invention. Furthermore, the U-phase bus bar 22U, the V-phase bus bar 22V, and the W-phase bus bar 22W include a U-phase terminal portion 22U3 extending radially outward of the stator core 12 from the first extension portions 22U1, 22V1, and 22W1, a V-phase terminal It has a portion 22V3 and a W-phase terminal portion 22W3 (see FIGS. 1 and 2). The U-phase terminal portion 22U3, the V-phase terminal portion 22V3, and the W-phase terminal portion 22W3 may be configured to extend outward in the axial direction of the stator core 12 from the first extension portions 22U1, 22V1, and 22W1.

First extension portion 22U1 of U-phase bus bar 22U, first extension portion 22V1 of V-phase bus bar 22V, and first extension portion 221W1 of W-phase bus bar 22W are arranged concentrically with stator core 12. . The first extension portion 22U1, the first extension portion 22V1, and the first extension portion 22W1 are arranged in this order from the radially outer side of the stator core 12 with a gap therebetween. The first extending portions 22U1, 22V1, 22W1 are arranged in a region overlapping the yoke 14 when viewed from the axial direction of the stator core 12. As shown in FIG. The positional relationship of the first extension portion 22U1, the first extension portion 22V1, and the first extension portion 22W1 in the radial direction of the stator core 12 is merely an example, and can be changed as appropriate. Alternatively, a plurality of bus bars may be arranged in the axial direction of the stator core 12 .

First coil joint portions 22U2, 22V2, and 22W2 once extend from first extension portions 22U1, 22V1, and 22W1 to the opposite side of stator core 12, and then bend radially inward of stator core 12. A tip portion is arranged near the root of each tooth 16 . The tip surfaces of the first coil joint portions 22U2, 22V2, and 22W2 face radially inward of the stator core 12. As shown in FIG. The radial direction of the stator core 12 corresponds to the "third direction" in the present invention. The axial direction, circumferential direction, and radial direction of the stator core 12 are orthogonal to each other.

As shown in FIG. 6 , two concave curved surfaces 23 that are circularly concave radially outward of the stator core 12 when viewed from the axial direction of the stator core 12 are provided on the tip surfaces of the first coil joint portions 22U2, 22V2, and 22W2. (reference numerals omitted except in FIG. 6) are formed side by side in the circumferential direction of the stator core 12 . The outer peripheral surfaces of the two coil terminals 181 are in contact with the two concave curved surfaces 23 respectively. Each concave curved surface 23 is formed concentrically with the outer peripheral surface of each coil end 181 .

In addition, at each tip of the first coil joints 22U2, 22V2, and 22W2, a tension member that is in contact with one coil end 181 from the side opposite to the other coil end 181 (that is, from one side in the circumferential direction of the stator core 12). An outlet 25 is provided. As a result, the distal end portions of the first coil joint portions 22U2, 22V2, and 22W2 are formed in an asymmetrical shape in the circumferential direction of the stator core 12. As shown in FIG. As will be described in detail later, two coil ends 181 are welded to each tip of the first coil joints 22U2, 22V2, and 22W2. A configuration in which the two concave curved surfaces 23 are not formed on each tip end surface of each of the one joint portions 22U2, 22V2, and 22W2 may be adopted. In that case, for example, the tip end surfaces of the one joint portions 22U2, 22V2, and 22W2 are flat surfaces, and two coil terminals 181 are in contact with the flat surfaces.

Each of the plurality of busbar divisions 24S constituting the second busbar includes a second extending portion 24S1 extending in an arc shape in the circumferential direction of the stator core 12 along the yoke 14, and the teeth 16 extending from the second extending portion 24S1. and a plurality of (here, three) second coil joint portions 24S2 extending toward the distal end side of the coil. The second extension portion 24S1 is spaced radially inward of the stator core 12 with respect to the first extension portion 22W1 of the W-phase bus bar 22W, and is curved in an arc concentric with the stator core 12. .

The plurality of second coil joint portions 24S2 extends from the second extension portion 24S1 to the side opposite to the stator core 12 and then bends radially inward of the stator core 12. located near the tip of the The tip surface of each second coil joint portion 24S2 faces radially inward of the stator core 12. As shown in FIG. As shown in FIG. 6 , two concave curved surfaces 23 (other than FIG. 6 ) that are arcuately recessed radially outward of the stator core 12 when viewed from the axial direction of the stator core 12 are formed on the tip surface of each second coil joint portion 24S2. ) are formed side by side in the circumferential direction of the stator core 12 . The outer peripheral surfaces of the two coil terminals 182 are in contact with the two concave curved surfaces 23 respectively. Each concave curved surface 23 is formed concentrically with the outer peripheral surface of each coil end 182 .

At the tip of the second coil joint portion 24S2, an overhang portion 25 is provided that contacts one coil end 182 from the side opposite to the other coil end 182 (that is, one side in the circumferential direction of the stator core 12). It is As a result, the distal end portion of the second coil joint portion 24S2 is formed in an asymmetrical shape in the circumferential direction of the stator core 12. As shown in FIG. As will be described in detail later, two coil ends 182 are welded to the tip of the second coil joint portion 24S2. A configuration in which the two concave curved surfaces 23 are not formed on the distal end surface of the second coil joint portion 24S2 may be adopted. In that case, for example, the distal end surface of the second coil joint portion 24S2 is a flat surface, and two coil terminals 182 are in contact with the flat surface. Alternatively, the second busbar 24 may be integrally formed without being divided into a plurality of busbar divisions 24S.

The insulator 26 is made of mold resin, for example, and has an annular shape. This insulator 26 is fitted inside the case 28 . The insulator 26 is made by kneading a thermosetting resin such as an epoxy resin, a thermoplastic resin, or the like with non-magnetic powder as a filler, and has thermal conductivity and insulating properties. The insulator 26 is embedded with the first extending portions 22U1, 22V1, 22W1 of the U-phase busbar 22U, the V-phase busbar 22V, and the W-phase busbar 22W, and the second extending portions 24S1 of the plurality of busbar divisions 24S. is The insulators 26 hold the first extending portions 22U1, 22V1, 22W1 of the U-phase busbar 22U, the V-phase busbar 22V, and the W-phase busbar 22W, and the second extending portions 24S1 of the plurality of busbar divisions 24S. ing.

It should be noted that the configuration of the insulator 26 is not limited to the above and can be changed as appropriate. For example, a plurality of annular grooves are concentrically formed in the insulator 26, which is annularly molded from a resin having thermal conductivity and insulating properties, opening to one side of the stator core 12 in the axial direction. A configuration may be adopted in which the first extension portions 22U1, 22V1, 22W1 and the second extension portion 24S1 are inserted and held. Further, for example, an insulator (not shown) interposed between the stator core 12 and each coil 18 and the insulator 26 may be integrated.

Next, the main part of this embodiment will be described. In the method of manufacturing the stator according to the present embodiment, two coil terminals 181 are welded to each tip of the first coil joints 22U2, 22V2, and 22W2, and two coil terminals 181 are welded to the tip of the second coil joint 24S2. Coil ends 182 are welded. The welding of the two coil terminals 181 to each tip of the first coil joints 22U2, 22V2, and 22W2 and the welding of the two coil terminals 182 to the tip of the second coil joint 24S2 are basically the same. Since they are basically the same, welding of the two coil ends 181 to the tip of the first coil joint portion 22U2 will be mainly described below, and welding of other portions will be omitted. In the following description, first coil junction 22U2 may be simply referred to as "coil junction 22U2", and U-phase bus bar 22U may be simply referred to as "bus bar 22U".

An arc welder 40 shown in FIG. 7 is used for the above welding. The arc welder 40 has a welder body 42, a torch 44, and a drive source (not shown) for driving the torch 44 up and down. A lower end of the torch 44 is provided with a tungsten electrode 46 and an outlet (not shown) for argon gas G, which is an inert gas. Two coil ends 181 are arranged below the tungsten electrode 46 and are brought into contact with the coil joint portion 22U2 of the bus bar 22U toward the radially outer side of the stator core 12 . The two coil ends 181 are brought into contact with the coil joint portion 22U2 using a jig provided in the arc welder 40, for example.

In welding using the arc welder 40, first, the two coil ends 181 are brought into contact with the coil joint portion 22U2 toward the radially outer side of the stator core 12 as described above, and one coil is A tungsten electrode 46 is brought into contact with a position of the terminal 181 near the other coil terminal 181 (refer to the position labeled WP1 in FIG. 6) to confirm continuity. At this time, the reason why the tungsten electrode 46 is brought into contact with one coil end 181 is to ensure that the arc discharge is made in the targeted direction and the whole is welded uniformly. The above position is set, for example, in a one-third region of one coil terminal 181 near the other coil terminal 181 . Further, for example, in the case of high-voltage arc welding, it is not necessary to bring the tungsten electrode 46 and the coil end 181 into contact with each other. Arc welding can be performed by applying a high-frequency voltage to cause dielectric breakdown in the air even when the two are separated from each other. In the case of high-voltage arc welding, for example, three-dimensional image recognition eliminates the need to bring the tungsten electrode 46 into contact with the one coil end 181 .

Next, the torch 44 is lifted upward to generate an arc between one coil terminal 181 and the tungsten electrode 46 . Next, after the torch 44 is pulled up to a predetermined height, final welding is performed. As a result, the two coil ends 181 are welded to the coil joint portion 22U2. The welding current is, for example, within the range of 100A to 300A, and the welding time is, for example, within the range of 0.1 to 0.3 seconds.

In the above welding, the volume of the coil joint 22U2 is set larger on the side of one coil end 181 (the coil end 181 denoted by symbol WP1 in FIG. 6) than on the other coil end 181 side. Specifically, in the present embodiment, the coil joint portion 22U2 is provided with an overhang portion 25 that contacts one coil terminal 181 from the side opposite to the other coil terminal 181, so that the coil joint portion 22U2 is connected to the stator core. It is formed in an asymmetrical shape in the 12 circumferential directions (second directions). As a result, the total volume of the two coil terminals 181 and the coil joint portion 22U2 is set larger on one coil terminal 181 side than on the other coil terminal 181 side. Then, with the volume set as described above, the coil joint portion 22U2 and the two coil ends 181 are welded. FIG. 8 shows a plan view of the configuration around the welded portion 30 between the coil joint portion 22U2 and the two coil terminals 181, and FIG. shown in the figure. Note that the volume of the two coil terminals 181 is divided into a portion of the two coil terminals 181 that overlaps the coil joint portion 22U2 when viewed from the radial direction (third direction) of the stator core 12, and two coil terminals 181 that overlap with the coil joint portion 22U2. It is the volume of the tip side portion of the coil terminal 181 .

When the welding of the two coil terminals 181 to the plurality of first coil joints 22U2, 22V2, and 22W2 and the welding of the two coil terminals 182 to the plurality of second coil joints 24S2 are completed, the stator 10 is completed. do. In the completed stator 10, U-phase terminal portions 22U3, V-phase terminal portions 22V3, and W-phase terminal portions 22W3 of U-phase busbar 22U, V-phase busbar 22V, and W-phase busbar 22W are connected to a three-phase power source. As a result, the stator 10 configured as described above functions as a stator of a three-phase motor.

(Action and effect)
In this embodiment, stator 10 is manufactured by welding two coil ends 181 led out from coils 18 wound around teeth 16 of stator core 12 to coil joints 22U2 of bus bar 22U. In this manufacturing method, two coil ends 181 each extending in the axial direction of the stator core 12 and in contact with each other in the circumferential direction of the stator core 12 are arranged in the radial direction of the stator core 12 with respect to the tip surface of the coil joint portion 22U2. be brought into contact. In this state, an arc is generated between one coil terminal 181 and the tungsten electrode 46 of the arc welder 40, and the two coil terminals 181 are welded to the coil joint 22U2. That is, arc welding is performed by aiming at one of the two coil terminals 181 .

In the above welding, the total volume of the coil joints 22U2 is set larger on one coil terminal 181 side than on the other coil terminal 181 side. As a result, when arc welding is performed targeting one coil terminal 181, the heat capacities of the one coil terminal 181 side and the other coil terminal 181 side, including the coil joint portion 22U2, can be equalized. As a result, the two coil ends 181 and the coil joint portion 22U2 can be evenly melted on both sides, so that the two coil ends 181 are evenly welded to the U-phase bus bar 22U in one welding. It becomes possible to

Also, in the present embodiment, the coil joint portion 22U2 of the U-phase bus bar 22U is formed in an asymmetrical shape in the circumferential direction of the stator core 12. Thereby, the volume of the coil joint portion 22U2 can be set larger on one coil terminal 181 side than on the other coil terminal 181 side.

In addition, in the present embodiment, the coil joint portion 22U2 is provided with an overhang portion 25 that contacts one coil terminal 181 from the side opposite to the other coil terminal 181 . As a result, the coil joint portion 22U2 can be formed in an asymmetrical shape in the circumferential direction of the stator core 12, and the volume of the coil joint portion 22U2 can be set larger on one coil terminal 181 side than on the other coil terminal 181 side. can.

The effect of this embodiment will be supplemented with reference to the comparative example shown in FIGS. In this comparative example, the coil joint portion 22U2 is provided with overhanging portions 25 on both sides of the stator core 12 in the circumferential direction with respect to the two coil terminals 181, and the coil joint portion 22U2 extends in the circumferential direction of the stator core 12. It is formed in a symmetrical shape. The volume of the coil joint portion 22U2 is set equal between the one coil terminal 181 side and the other coil terminal 181 side. In this comparative example, when arc welding is performed aiming at a position near the other coil terminal 181 (see the position labeled WP1 in FIG. 10) in one coil terminal 181, as shown in FIG. The other coil terminal 181 side is preferentially melted, and the welding part 30 is biased toward one coil terminal 181 side, so that the other coil terminal 181 is insufficiently welded.

In the above comparative example, arc welding can be performed by aiming at a position near the middle of the two coil terminals 181 in the coil joint portion 22U2 (the position denoted by symbol WP2 in FIG. 10). , two coil ends 181 are melted in the vicinity of the positions denoted by reference numerals WP2, but the entire area of the two coil ends 181 is not melted, resulting in insufficient welding. Further, in the above comparative example, the two protruding portions 25 of the coil joint portion 22U2 can be crimped in a direction approaching each other to be electrically connected to the two coil ends 181, and welding can be performed in this state. is. However, if there is a variation in the strength of the crimping, the melting tends to propagate to the side of the two coil ends 181 that is in strong contact with the coil joint portion 22U2, resulting in variation in the welded state. Therefore, it is preferable to bring the coil joint portion 22U2 into contact with the two coil terminals 181 using a jig or the like without caulking.

In this embodiment, the two coil ends 181 can be evenly welded to the U-phase bus bar 22U by one welding, so that the production tact time can be shortened while improving quality, durability, and production yield. can be done. In addition, since the caulking process is unnecessary, the manufacturing process can be simplified. Furthermore, since it is not necessary to secure a space for inserting a crimping tool in the stator 10, the space can be used effectively.

In this embodiment, the first insertion portions 23 into which the coil terminals 181 of the coils 18 are inserted are formed in the first coil joint portions 22U2, 22V2, 22W2 of the first busbars 22, and the second busbars 24 A second insertion portion 25 into which the coil end 182 of the coil 18 is inserted is formed in the second coil joint portion 24S2. This insertion stabilizes the positional relationship between the

coil terminals

181 and 182 of the coil 18 and the first coil joints 22U2, 22V2, 22W2 and the second coil joints 24S2. The work of joining the first coil joints 22U2, 22V2, 22W2 and the second coil joints 24S2 is facilitated.

<Modification>
Modifications of the present embodiment will be described below with reference to FIGS. 12 to 20. FIG. 12 to 20, the same reference numerals are given to the same configurations as in the above-described embodiment. 13 and 15, SW is the wire of the coil 18, and IC is the insulating coating of the coil 18. As shown in FIG. In the first modification shown in FIGS. 12 and 13, the coil joint portion 22U2 is not formed in an asymmetrical shape, but the two wires forming the coil 18 are set to have different thicknesses. The coil terminals 181 of the book have different thicknesses. For example, the diameter of one coil terminal 181 is set to φ2.0, and the diameter of the other coil terminal 181 is set to φ1.5. In this first modified example, arc welding is performed aiming at a position of one coil terminal 181 near the other coil terminal 181 (see the position denoted by reference numeral WP1 in FIG. 12). As a result, the total volume of the two coil terminals 181 and the coil joint portion 22U2 is set larger on one coil terminal 181 side than on the other coil terminal 181 side. Also in this first modified example, the heat capacities including the coil joint portion 22U2 can be equalized between the one coil terminal 181 side and the other coil terminal 181 side. As a result, the two coil ends 181 and the coil joint portion 22U2 can be evenly melted on both sides, so that the two coil ends 181 are evenly welded to the U-phase bus bar 22U in one welding. It becomes possible to 12 and 13 show a method of uniformly welding by changing the diameter of the coil terminals 181, but the two coil terminals 181 are assumed to have the same diameter and the height is changed. It is also possible to make a difference in heat capacity by increasing the height of the heat capacity. It is also possible to change both the diameter and height of the coil terminal 181 to make a difference in heat capacity.

In the second modification shown in FIGS. 14 and 15, the two wires forming the coil 18 are set to have the same thickness. At 181, the electric wire is shaved more than one coil end 181. As a result, the other coil terminal 181 is made thinner than the one coil terminal 181 . In this second modification, arc welding is performed by aiming at a position of one coil end 181 near the other coil end 181 (see the position denoted by reference numeral WP1 in FIG. 14). Also in this second modification, the heat capacities including the coil joint portion 22U2 can be equalized between the one coil terminal 181 side and the other coil terminal 181 side. As a result, the two coil ends 181 and the coil joint portion 22U2 can be evenly melted on both sides, so that the two coil ends 181 are evenly welded to the U-phase bus bar 22U in one welding. It becomes possible to

The same effects as those of the above-described embodiment can be obtained in the above-described first modified example and second modified example. Moreover, in the above-described first and second modified examples, the coil joint portion 22U2 does not need to have an asymmetrical shape, so there is no need to distinguish the orientation of the coil joint portion 22U2 during manufacturing, which facilitates manufacturing. .

In the third modification shown in FIGS. 16 and 17, two coil terminals 181 are arranged in the radial direction of the stator core 12, and the two coil terminals 181 and the coil joint 22U2 are arranged in the circumferential direction of the stator core 12. in contact. This third modification also provides the same effects as those of the above-described embodiment.

In the fourth modification shown in FIGS. 18 and 19, two coil terminals 181 are arranged in the radial direction of the stator core 12 as in the third modification. The coil joint portion 22U2 has a plate shape whose plate thickness direction is the circumferential direction of the stator core 12, and is in contact with the two coil terminals 181 in the circumferential direction of the stator core 12. As shown in FIG. The distal end portion of the coil joint portion 22U2 is formed as an overhang portion 25 curved in an arc shape toward one side in the stator core circumferential direction, and contacts one coil end portion 181 from the opposite side to the other coil end portion 181. ing. This fourth modification also provides the same effects as those of the above-described embodiment. 16 and 18 show examples in which the two coil terminals 181 are arranged in the radial direction of the stator core 12 , but the two coil terminals 181 are arranged diagonally with respect to the radial direction of the stator core 12 . You can configure it.

The fifth modification shown in FIG. 20 is similar to the fourth modification, but two coil terminals 181 are arranged in the circumferential direction of the stator core 12, and the coil joint portion 22U2 is connected to the two coil terminals 181. is in contact with the stator core 12 in the radial direction. This fourth modification also provides the same effects as those of the above-described embodiment.

In the sixth modification shown in FIG. 21, two coil terminals 181 are brought into contact with the end face of the coil joint portion 22U2 using a jig 50. In this state, an arc is generated between one coil terminal 181 and the tungsten electrode 46 of the arc welder 40, and the two coil terminals 181 are welded to the coil joint 22U2. During this welding, the total volume of the two coil ends 181, the coil joint portion 22U2 and the jig 50 is set larger on one coil end 181 side than on the other coil end 181 side. Specifically, the jig 50 is provided with a protruding portion 51 that contacts one coil terminal 181 from the opposite side to the other coil terminal 181, and the jig 50 has an asymmetrical shape. ing. As a result, when arc welding is performed targeting one coil terminal 181, the heat capacities of the one coil terminal 181 side and the other coil terminal 181 side, including the coil joint portion 22U2 and the jig 50, are equalized. be able to. This sixth modification can also provide the same effect as the above embodiment.

Although the present invention has been described above with reference to the embodiment and some modifications, the present invention can be implemented with various modifications without departing from the gist thereof. In addition, it goes without saying that the scope of rights of the present invention is not limited to the above-described embodiments and modifications.

In addition, the disclosure of Japanese Patent Application No. 2021-160056 filed on September 29, 2021 is incorporated herein by reference in its entirety. All publications, patent applications and technical standards mentioned herein are to the same extent as if each individual publication, patent application and technical standard were specifically and individually indicated to be incorporated by reference. incorporated herein by reference.

Claims

A stator manufacturing method for manufacturing a stator by welding two coil ends derived from coils wound around teeth of a stator core to coil joints of a bus bar,
The two coil terminals each extending in a first direction and adjacent to each other in a second direction perpendicular to the first direction are arranged in the first direction and the second direction with respect to the end face of the coil joint portion. When welding the two coil ends to the coil joint by generating an arc between one of the coil ends and an electrode of an arc welding machine in a state of contact in a third direction orthogonal to the A method for manufacturing a stator, wherein the total volume of two coil terminals and the coil joint is set larger on the one coil terminal side than on the other coil terminal side.
The method of manufacturing a stator according to claim 1, wherein the coil joint portion is formed in an asymmetrical shape in the second direction.
The method of manufacturing a stator according to claim 2, wherein the coil joint portion is provided with an overhang portion that contacts the one coil end from the side opposite to the other coil end.
A stator manufacturing method for manufacturing a stator by welding two coil ends derived from coils wound around teeth of a stator core to coil joints of a bus bar,
The two coil terminals each extending in a first direction and adjacent to each other in a second direction perpendicular to the first direction are arranged in the first direction and the second direction with respect to the end face of the coil joint portion. Arc is generated between one of the coil terminals and the electrode of the arc welder while contacting with a jig in a third direction orthogonal to A method for manufacturing a stator in which, when welding, the total volume of the two coil ends, the coil joint and the jig is set larger on the one coil end side than on the other coil end side.