JP2021016229A - Connection method for square-shaped conductor and manufacturing method of stator of rotary electric machine - Google Patents

Abstract

To provide a connection method for a square-shaped conductor capable of causing a sufficient current to flow in a connection of conductors.SOLUTION: A connection method for a square-shaped conductor includes the steps of: in the state where a first end face of a first conductor having a rectangular cross section and a second end face of a second conductor having a rectangular cross section are adjacent to each other, disposing a cover member over the first end face and the second end face so as to cover at least partially the first end face and the second end face; and melting the entire cover member by irradiating the cover member disposed over the first end face and the second end face with an energy beam, and generating a melting layer in which the cover member, an end portion of the first conductor and an end portion of the second conductor are molten.SELECTED DRAWING: Figure 5

Description

The present disclosure relates to a method of connecting a square lead wire and a method of manufacturing a stator of a rotary electric machine.

For example, in a rotary electric machine such as an electric motor or a generator, for example, a stator winding is mounted on a stator core to form a stator. Further, for example, in a rotary electric machine, in order to improve the space factor of the winding due to the demand for miniaturization and efficiency improvement, a square wire (square lead wire) having a rectangular cross section is used as the winding instead of a round wire having a circular cross section. It is supposed to be.
Further, for example, in a rotary electric machine, it is known that a plurality of segment conductors made of flat wire are connected and used as a stator winding (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-7794

For example, in Patent Document 1, as a conductor joining method for a rotary electric machine, a plate-shaped conductive plate is installed on the tip surface of each of the two segment conductors to be joined, and a laser is irradiated to form the two segment conductors. It is disclosed that the respective tips are welded to the conductive plate.
In the conductor joining method described in Patent Document 1, the current flowing between the two segment conductors mainly flows through the conductive plate. However, when the contact between the tip surface of the segment conductor and the surface of the conductive plate facing the tip surface is not good, the current flowing between the segment conductor and the conductive plate is mainly conductive with the tip of the segment conductor. The current flows through the portion where the plate is joined so as to be skewered, that is, the molten region formed so as to extend along the extending direction of the segment conductor during laser irradiation. The cross-sectional area of the joined portion is smaller than the area of the tip surface of the segment conductor. Therefore, it may be difficult to pass a sufficiently large current between the two segment conductors.

In view of the above circumstances, it is an object of at least one embodiment of the present disclosure to provide a method for connecting a square conducting wire capable of passing a sufficient current at a connecting portion between the conducting wires.

(1) The method of connecting the square lead wire according to at least one embodiment of the present disclosure is as follows.
With the first end face of the first lead wire having a rectangular cross section and the second end face of the second lead wire having a rectangular cross section adjacent to each other, the first end face and the first end face straddling the first end face and the second end face. A step of arranging the covering member so as to cover at least a part of the second end surface, and
An energy beam is applied to the covering member arranged so as to straddle the first end surface and the second end surface to melt the entire covering member, and the covering member, the end portion of the first lead wire, and the first lead wire are melted. 2 Steps to form a molten layer in which the ends of the conductors are melted,
To be equipped.

According to the method (1) above, the entire covering member is melted to form a molten layer in which the covering member, the end of the first lead wire, and the end of the second lead wire are melted, so that the first lead wire and the first lead wire are formed. It is possible to secure the size of the connecting portion in which the two conducting wires are connected by welding. This makes it possible to pass a sufficient current through the connection portion. Therefore, the reliability of the connection between the first lead wire and the second lead wire can be improved.
Further, according to the method (1) above, at least a part of the first end face and the second end face is covered with a covering member straddling the first end face and the second end face, so that, for example, the end of the first lead wire and the second end face Even if there is a gap between the wire and the end of the wire, it is possible to prevent the irradiated energy beam from passing through the gap and insufficiently forming the molten layer.
Further, according to the method (1) above, it is possible to prevent the irradiated energy beam from passing through the gap as described above, so that it is not necessary to unnecessarily increase the output of the energy beam and the energy beam. It is possible to prevent the performance required for the irradiation device for outputting the energy from becoming excessive.

(2) In some embodiments, in the method (1) above, the step of arranging the covering member is a step of arranging the first end surface and the end facing portion formed so as to face the second end surface. The covering member having the first lead wire and the side facing portion formed so as to face at least a part of the side surface of the second lead wire is provided with the first end face and the second end face at the end facing portion. Arrange so as to cover at least a part of.

According to the method (2) above, the side facing portion and at least a part of the side surface of the first lead wire and the second lead wire come into contact with each other, so that the position shift between the first lead wire or the second lead wire and the covering member is prevented. Can be prevented.

(3) In some embodiments, in the method (1) or (2), the step of arranging the covering member is an extension of the first end surface and the second lead wire with respect to the first end surface. The covering member is arranged so as to straddle the second end surface arranged at a position protruding in the existing direction.

According to the method (3) above, even if the positions of the first end face and the second end face are deviated in the extending direction of the first lead wire or the second lead wire, they are arranged across the first end face and the second end face. By irradiating the covered member with an energy beam, the above-mentioned molten layer can be formed.

(4) In some embodiments, in any of the methods (1) to (3) above, the step of forming the molten layer is performed by irradiating the energy beam while scanning the entire covering member. Is melted to form a molten layer in which the covering member, the end of the first lead wire, and the end of the second lead wire are melted.

According to the method (4) above, the above-mentioned molten layer can be efficiently formed.

(5) In some embodiments, in any of the methods (1) to (3), the step of forming the molten layer is the edge of the first end face of the covering member and the second. The energy beam is irradiated to a portion covering a region where the edge portions of the end faces are adjacent to each other to melt the entire covering member, and the end portion of the covering member, the first lead wire, and the second lead wire. A molten layer is formed in which the ends are melted.

According to the method (5) above, it is possible to prevent the shape of the molten layer described above from being different between the first lead wire side and the second lead wire side.

(6) In some embodiments, in any of the methods (1) to (5), the step of arranging the covering member straddles the first end surface and the second end surface facing upward, respectively. The covering member is arranged so as to cover at least a part of the first end surface and the second end surface.

According to the method (6) above, it is less necessary to temporarily fix the arranged covering member to the first lead wire or the second lead wire, and the labor and cost required for the temporary fix can be suppressed.

(7) In some embodiments, in any of the methods (1) to (6) above, the step of arranging the covering member is formed so as to face the first end surface and the second end surface. The covering member having a plate thickness of 0.1 mm or more and 0.5 mm or less at the end facing portion is arranged so as to straddle the first end face and the second end face.

As a result of diligent studies by the inventors, if the plate thickness of the end facing portion is 0.1 mm or more, even if there is a gap between the end of the first lead wire and the end of the second lead wire. It was found that it is possible to prevent the irradiated energy beam from penetrating the covering member and passing through the gap. Further, as a result of diligent studies by the inventors, it was found that if the plate thickness of the end facing portion is 0.5 mm or less, the time required for forming the above-mentioned molten layer hardly changes depending on the presence or absence of the covering member. It was.
According to the method (7) above, the above-mentioned molten layer can be efficiently formed.

(8) In some embodiments, in any of the methods (1) to (7), the step of arranging the covering member is made of the same material as the first lead wire and the second lead wire. The covering member is arranged so as to straddle the first end surface and the second end surface.

According to the method (8) described above, the composition of the molten layer described above is the same as that of the first and second conducting wires, so that the influence on the electrical characteristics can be suppressed.

(9) In some embodiments, in any of the methods (1) to (7), the step of arranging the covering member is a covering whose material is different from that of the first conducting wire and the second conducting wire. The member is arranged so as to straddle the first end surface and the second end surface.

According to the method (9) above, for example, if the covering member is made of a material having a higher absorption rate of the energy beam than the first lead wire and the second lead wire, the above-mentioned molten layer can be efficiently generated.

(10) In some embodiments, in any of the methods (1) to (9) above, the step of arranging the covering member is such that the length of one side of the rectangular cross section is 1 mm or more and 5 mm or less. The covering member may be arranged so as to straddle the first end surface of the first lead wire and the second end face of the second lead wire having a length of one side of the rectangular cross section of 1 mm or more and 5 mm or less.

(11) In some embodiments, in any of the methods (1) to (10) above,
The first lead wire is inserted from one end of one of the plurality of slots in the stator core of the rotary electric machine toward the other end, and the first end surface protrudes from the other end to the outside of the one slot. Steps to make and
A step of inserting the second lead wire from one end of another slot different from the one slot toward the other end to project the second end surface from the other end to the outside of the other slot.
A step of arranging the first end face and the second end face projecting to the outside of the slot next to each other,
With more
The step of arranging the covering member is carried out after performing the step of arranging the covering members next to each other.

According to the method (11) above, the windings of the stator of the rotary electric machine can be efficiently connected.

(12) The method for manufacturing a stator of a rotary electric machine according to at least one embodiment of the present disclosure is described.
A first lead wire having a rectangular cross section is inserted from one end of one slot of a plurality of slots in a stator core of a rotary electric machine toward the other end, and the first end surface of the first lead wire is inserted from the other end. Steps to project outside one slot,
A second lead wire having a rectangular cross section is inserted from one end of another slot different from the one slot toward the other end, and the second end surface of the second lead wire is moved from the other end to the outside of the other slot. Steps to protrude and
A step of arranging the first end face and the second end face projecting to the outside of the slot next to each other,
A step of arranging a covering member so as to cover at least a part of the first end face and the second end face straddling the first end face and the second end face arranged adjacent to each other.
An energy beam is applied to the covering member arranged so as to straddle the first end surface and the second end surface to melt the entire covering member, and the covering member, the end portion of the first lead wire, and the first lead wire are melted. 2 Steps to form a molten layer in which the ends of the conductors are melted,
To be equipped.

According to the method (12) above, the stator of the rotary electric machine can be efficiently manufactured.

According to at least one embodiment of the present disclosure, it is possible to provide a method for connecting a square lead wire capable of passing a sufficient current at a connection portion between the lead wires.

It is a figure which showed typically the structure of the rotary electric machine which concerns on some Embodiments. It is a perspective view of the housing and the stator which concerns on some embodiments. It is a schematic perspective view of the segment conductor which constitutes a stator winding. It is a schematic diagram for demonstrating the process of forming a stator winding which concerns on some embodiments. It is a schematic diagram which shows the neighborhood of the end part in the state where the end faces are arranged side by side. It is a schematic diagram which shows the state which the covering member is arranged across two end faces arranged side by side. It is a schematic view which looked at the covering member arranged over two end faces arranged side by side from above. It is a schematic perspective view about an example of the covering member which concerns on some embodiments. It is a schematic diagram which shows the state immediately after starting the irradiation of a laser beam after arranging the covering member on the end face of a segment conductor. It is a schematic diagram which shows the state immediately after starting the irradiation of a laser beam. It is a figure which shows typically the formation state of the molten layer. It is a figure which shows an example of another embodiment about the irradiation of a laser beam. It is a schematic diagram which shows the mode that the covering member is arranged on the end faces arranged side by side. It is a schematic diagram which shows the state after arranging the covering member on the end face when the position of the 1st end face and the 2nd end face is deviated in the extending direction of a 1st lead wire and a 2nd lead wire. It is a flowchart which shows the processing procedure in the manufacturing method of the stator of the rotary electric machine which concerns on some Embodiments.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention to this, but are merely explanatory examples. Absent.
For example, expressions that represent relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" are exact. Not only does it represent such an arrangement, but it also represents a state of relative displacement with tolerances or angles and distances to the extent that the same function can be obtained.
For example, expressions such as "same", "equal", and "homogeneous" that indicate that things are in the same state not only represent exactly the same state, but also have tolerances or differences to the extent that the same function can be obtained. It shall also represent the state of existence.
For example, the expression representing a shape such as a quadrangular shape or a cylindrical shape not only represents a shape such as a quadrangular shape or a cylindrical shape in a geometrically strict sense, but also an uneven portion or chamfering within a range where the same effect can be obtained. The shape including the part and the like shall also be represented.
On the other hand, the expressions "equipped", "equipped", "equipped", "included", or "have" one component are not exclusive expressions that exclude the existence of other components.

(Outline of configuration of rotary electric machine 1)
FIG. 1 is a diagram schematically showing the configuration of a rotary electric machine according to some embodiments. FIG. 1 illustrates a partial cross section of a rotary electric machine according to some embodiments. The rotary electric machine 1 shown in FIG. 1 may be used as an electric motor or a generator.
The rotary electric machine 1 according to some embodiments includes a housing 3 and a stator 10 fixed inside the housing 3. The stator 10 includes a stator core 11 and a stator winding 13. Inside the stator core 11, a rotor 5 is rotatably held through a gap. The rotor 5 is fixed to a columnar shaft 7. The housing 3, the stator 10, and the rotor 5 are arranged inside the case 9. The case 9 rotatably supports the shaft 7.
In the following description, the extending direction of the axis AX of the shaft 7 is also simply referred to as the axial direction, the circumferential direction centered on the axis AX is also simply referred to as the circumferential direction, and the radial direction centered on the axis AX is also simply referred to as the radial direction. ..

FIG. 2 is a perspective view of the housing 3 and the stator 10 according to some embodiments. The stator 10 shown in FIG. 2 is in a state before the end portions 25 of the segment conductors 20, which will be described later, are connected to each other by welding.
FIG. 3 is a schematic perspective view of the segment conductor 20 constituting the stator winding 13, and shows a state before being mounted on the stator core 11.

In the stator 10 according to some embodiments, a square wire (square lead wire) having a rectangular cross section is used as the stator winding 13 in order to improve the space factor of the winding due to a request for miniaturization and efficiency improvement of the rotary electric machine 1. ) 2 is used. In some embodiments, the square conductor 2 is formed into a segment conductor 20 having a U-shape as shown in FIG. That is, in some embodiments, the segment conductor 20 has a U-shaped portion 21 bent in a U-shape and two straight-line portions 23 extending linearly from the U-shaped portion 21.
Although not shown in FIG. 3, the surface of the square conductor 2 used for the segment conductor 20 according to some embodiments is coated with an insulating coating 29 (see FIG. 5) such as enamel. You may.
In the stator 10 according to some embodiments, the stator windings are formed by connecting the ends 25 of the plurality of segment conductors 20 inserted into the plurality of slots 15 of the stator core 11 by welding as described later. 13 is formed.

(Outline of the procedure for forming the stator winding 13)
FIG. 4 is a schematic diagram for explaining a procedure for forming the stator winding 13 according to some embodiments. Note that FIG. 4 shows a state in which the stator 10 is unfolded along the circumferential direction when viewed from the inside in the radial direction.
For convenience of explanation, FIG. 4 will refer to two segment conductors 20 in which the end portions 25 of the straight line portions 23 are connected by welding as described later, out of a large number of segment conductors 20. In the following description, when it is necessary to distinguish between the two segment conductors 20, one segment conductor 20 is referred to as a first segment conductor 20A, and the other segment conductor 20 is referred to as a second segment conductor 20B. .. Further, the square conductor 2 constituting the first segment conductor 20A is also referred to as a first conductor 2A, and the square conductor 2 constituting the second segment conductor 20B is also referred to as a second conductor 2B.

In some embodiments, the stator winding 13 is formed as follows.
For example, in some embodiments, the segment conductor 20 as shown in FIG. 3 is inserted into the slot 15 of the stator core 11 from the axial direction. At this time, the straight portion 23 of the segment conductor 20 is inserted into the two slots 15 that are separated from each other across the plurality of slots 15. For example, in some embodiments, the segment conductor 20 is maintained in the posture of the stator core 11 so that the axial direction of the stator core 11 is the same as the vertical direction, as shown by the arrow a in FIG. Is inserted into the slot 15 from the bottom to the top.
In this way, the straight portion 23 is inserted from one end of the slot 15 toward the other end, and the end surface 27 on the tip end side of the straight portion 23 is projected from the other end of the slot 15 to the outside of the slot 15.

Next, in order to electrically connect the ends 25 to each other by welding, one end 25 of the first segment conductor 20A and one end 25 of the second segment conductor 20B are brought close to each other to bring the first segment into the first segment. The end face 27 of one end 25 of the conductor 20A and the end face 27 of one end 25 of the second segment conductor 20B are arranged next to each other. Specifically, as shown by the arrow b in FIG. 4, the end portion 25 is connected to the segment conductor 20 of the connection partner by bending each of the linear portions 23 protruding from the other end of the slot 15 to the outside of the slot 15. Close to the end 25 of. Then, as shown by the arrow c in FIG. 4, each end portion 25 is bent so that the end faces 27 face in the same direction, for example, upward at the end portions 25 that are close to each other. As a result, the end face 27 of one end 25 of the first segment conductor 20A and the end face 27 of one end 25 of the second segment conductor 20B are arranged next to each other.
FIG. 5 is a schematic view showing the vicinity of the end portion 25 in a state where the end faces 27 are arranged next to each other as described above. As shown in FIG. 5, in some embodiments, one end 25 of the first segment conductor 20A and one end 25 of the second segment conductor 20B are arranged along the radial direction, but the circumference They may be lined up along the direction.
It is desirable that the insulating coating 29 at the end portion 25 is removed in advance.
In the following description, the end surface 27 of the first segment conductor 20A (first conductor 2A) is also referred to as the first end surface 27A, and the end surface 27 of the second segment conductor 20B (second conductor 2B) is also referred to as the second end surface 27B.

Next, the ends 25 that are lined up next to each other are connected by welding. In some embodiments, the covering member 40 is placed across two side-by-side end faces 27, as indicated by arrows d in FIGS. 4 and 5, prior to welding the ends 25 to each other. .. Then, by irradiating the covering member 40 arranged on the end face 27 with an energy beam (for example, a laser beam), the end portion 25 together with the covering member 40 is melted and connected. Hereinafter, the method of connecting the square lead wires according to some embodiments will be described in detail. Note that FIG. 6 is a schematic view showing a state in which the covering member 40 is arranged so as to straddle the two end faces 27 arranged adjacent to each other. Further, FIG. 7 is a schematic view of a covering member 40 arranged so as to straddle two end faces 27 arranged adjacent to each other as viewed from above.

(About the connection method of the square lead wire)
In some embodiments, the ends 25 of the segment conductors 20 are welded together by a laser beam as described above. However, as shown in FIG. 5, for example, even if the straight portion 23 having the end portion 25 protruding outward from the slot 15 of the stator 10 is bent and the end faces 27 are arranged next to each other, one of the first lead wires 2A A gap 17 may be formed between the end portion 25 of the wire and one end portion 25 of the second lead wire 2B.

There are various causes for this gap 17, but the following causes can be given as some examples. For example, even if the straight line portion 23 is bent as described above, the side surface 25a of one end portion 25 of the first lead wire 2A and the side surface 25a of one end portion 25 of the second lead wire 2B are once brought into contact with each other. It is conceivable that the side surfaces 25a of the end portion 25 are separated from each other due to the springback of the square lead wire 2. In particular, as shown in FIG. 5, when the surface of the square lead wire 2 is provided with the insulating coating 29, the distances between the end portions 25 are further separated by the thickness of the insulating coating 29. It is also considered that a gap 17 is likely to occur.
Further, if the segment conductor 20 moves with respect to the stator core 11 due to the gap between the slot 15 and the straight portion 23, a gap 17 is generated.

When the ends 25 of the segment conductor 20 are connected by welding with an energy beam such as a laser beam, the molten layer generated by the laser beam and the connecting portion formed by solidification of the molten layer have two ends. It is desired that the shape does not become distorted, such as being biased toward any of the portions 25. Therefore, it is desirable that the laser beam irradiates the region where the edge portion 27a of one end face 27 and the edge portion 27a of the other end face 27 are adjacent to each other.
However, when the gap 17 as described above is present, the irradiated laser beam may escape from the gap 17 and the end face 27 may not be sufficiently heated.

Therefore, in the method of connecting the square lead wires according to some embodiments, two end faces arranged next to each other as shown by arrows d in FIGS. 4 and 5 prior to welding the end portions 25 to each other. The covering member 40 is arranged so as to straddle the 27.
As a result, since the covering member 40 covers the two end faces 27 arranged next to each other, the irradiated laser beam escapes from the gap 17 even if there is a gap 17 between the adjacent end portions 25. The covering member 40 suppresses this. As a result, even if there is a gap 17 between the adjacent end portions 25, the end face 27 can be sufficiently heated, so that the reliability of the connection between the adjacent end portions 25 by welding can be improved.

FIG. 8 is a schematic perspective view of an example of the covering member 40 according to some embodiments. In FIG. 8, the covering member 40 is drawn in such a posture that a surface facing the end surface 27 of the segment conductor 20 appears. The covering member 40 according to some embodiments includes an end facing portion 41 formed so as to face the first end surface 27A and the second end surface 27B arranged adjacent to each other, and the first lead wire 2A and the second lead wire 2B. It has a side facing portion 43 formed so as to face at least a part of the side surface 25a of the above. That is, for example, the covering member 40 according to some embodiments is a cap-shaped member having an end facing portion 41 as a top plate. In the covering member 40 shown in FIG. 8, the side facing portion 43 is formed over the entire circumference along the edge portion of the end facing portion 41, but is a portion along the edge portion of the end facing portion 41. There may be regions that are not formed.

In some embodiments, the covering member 40 is arranged so that the end facing portion 41 covers at least a part of the first end surface 27A and the second end surface 27B.
As a result, the side facing portion 43 comes into contact with at least a part of the side surface 25a of the first lead wire 2A and the second lead wire 2B, so that the position shift between the first lead wire 2A or the second lead wire 2B and the covering member 40 is prevented. Can be prevented. If the side facing portions 43 are provided at two locations separated by the end facing portion 41, the movement of at least one of the first lead wire 2A or the second lead wire 2B is restricted by the two side facing portions 43. it can. Further, as shown in FIG. 8, if the side facing portion 43 is provided over the entire circumference of the edge portion of the end facing portion 41, the first conducting wire 2A and the first conducting wire 2A and the second conducting wire 2A and the second in the direction parallel to the first end surface 27A and the second end surface 27B. It is possible to prevent the two lead wires 2B from being displaced from each other.

FIG. 9 is a schematic view showing a state immediately after the covering member 40 is arranged on the end surface 27 of the segment conductor 20 and then the irradiation of the laser beam is started, and is a view seen from above of the covering member 40. Similarly, FIG. 10 is a schematic view showing a state immediately after starting irradiation of the laser beam, and is a view of the covering member 40 and the segment conductor 20 viewed from the circumferential direction.
In some embodiments, for example, the edge portion 27a of the first end surface 27A and the edge portion 27a of the second end surface 27B of the laser beam 51 are adjacent to each other with respect to the covering member 40 arranged on the end surface 27. Irradiate the area. In other words, in some embodiments, the centroid of the projection plane including the first end face 27A and the second end face 27B when the first end face 27A and the second end face 27B arranged adjacent to each other are viewed from above. The laser beam 51 is irradiated toward G.
Then, in some embodiments, as shown in FIG. 11, the entire covering member 40 is melted to melt the covering member 40, the end portion 25 of the first lead wire 2A, and the end portion 25 of the second lead wire 2B. A molten layer 55 is formed. FIG. 11 is a diagram schematically showing the formation state of the molten layer 55. The connection portion 57 is formed by solidifying the molten layer 55. The connection portion 57 is a portion that electrically connects the end portion 25 of the first lead wire 2A and the end portion 25 of the second lead wire 2B.

According to some embodiments, the entire covering member 40 is melted to form a molten layer 55 in which the covering member 40, the end portion 25 of the first lead wire 2A, and the end portion 25 of the second lead wire 2B are melted. , The size of the connecting portion 57 in which the first lead wire 2A and the second lead wire 2B are connected by welding can be secured. This makes it possible for a sufficient current to flow through the connection portion 57. Therefore, the reliability of the connection between the first lead wire 2A and the second lead wire 2B can be improved. Here, the "sufficient current" may be, for example, a current equivalent to the allowable current that can be passed through the first lead wire 2A and the second lead wire 2B.
Further, according to some embodiments, at least a part of the first end surface 27A and the second end surface 27B is covered with the covering member 40 across the first end surface 27A and the second end surface 27B, so that, for example, the first lead wire 2A Even if a gap 17 exists between the end portion 25 and the end portion 25 of the second lead wire 2B, the irradiated laser beam passes through the gap 17 and the formation of the molten layer 55 becomes insufficient. It can be suppressed.
Further, according to some embodiments, since the existence of the gap 17 is allowed, high accuracy is not required for the alignment between the first end surface 27A and the second end surface 27B, which is required for manufacturing the stator 10. Time and manufacturing costs can be reduced.
According to some embodiments, since the covering member 40 is arranged on the first end surface 27A and the second end surface 27B, the covering member 40 to the first lead wire 2A and the first lead wire 2A and the first conductor 40 immediately after the start of laser beam irradiation. Since energy is used to melt the covering member 40 itself rather than heat being transferred to the end 25 of the two conducting wires 2B, the covering member 40 is preferentially melted. After that, heat energy is transferred from the melted covering member 40 to the end 25 of the first lead 2A and the second lead 2B, and the end 25 of the first lead 2A and the second lead 2B can be efficiently melted.

FIG. 12 is a diagram showing an example of another embodiment for irradiating a laser beam. In some embodiments, when the covering member 40 is irradiated with the laser beam 51, when the covering member 40 is viewed from above, that is, from the emission end side of the laser beam, it is within the region where the end facing portion 41 exists. The laser beam 51 may be irradiated while being scanned. In this case, for example, as shown in FIG. 12, scanning of the laser beam 51 is started from the centroid position of the first end surface 27A or the centroid position of the second end surface 27B when viewed from above, and the end facing portion is formed. The laser beam 51 may be scanned in a circular motion within the region where the 41 exists.

FIG. 13 is a schematic view showing how the covering member 40 is arranged on the end faces 27 arranged adjacent to each other. Note that FIG. 13 shows a case where the positions of the first end surface 27A and the second end surface 27B are displaced in the extending direction of the first lead wire 2A and the second lead wire 2B. In the example shown in FIG. 13, the second end surface 27B is arranged at a position protruding from the first end surface 27A in the extending direction of the second lead wire 2B.
In FIG. 14, when the positions of the first end surface 27A and the second end surface 27B are displaced in the extending direction of the first lead wire 2A and the second lead wire 2B as shown in FIG. 13, the covering member 40 is arranged on the end face 27. It is a schematic diagram which shows the state after it has been done.
As shown in FIG. 14, when the positions of the first end surface 27A and the second end surface 27B are deviated in the extending direction of the first lead wire 2A and the second lead wire 2B, when the cover member 40 is arranged on the end face 27, the cover member 40 is covered. The member 40 is in an inclined state with respect to the end surface 27, but the contact with the side surface 25a of the end portion 25 prevents the covering member 40 from slipping off. Therefore, as shown in FIG. 14, even if the positions of the first end surface 27A and the second end surface 27B are deviated in the extending direction of the first lead wire 2A or the second lead wire 2B, the first end face 27A and the second end face 27B The molten layer 55 can be formed by irradiating the covering member 40 arranged so as to straddle the above with a laser beam.

(About the manufacturing method of the stator of the rotary electric machine)
A method of manufacturing a stator of a rotary electric machine using the above-mentioned method of connecting a square lead wire will be described.
FIG. 15 is a flowchart showing a processing procedure in the method for manufacturing a stator of a rotary electric machine according to some embodiments. The method for manufacturing a stator of a rotary electric machine according to some embodiments includes an insertion step S1, a bending step S3, an arrangement step S5, and a welding step S7.
In the insertion step S1, the first lead wire 2A having a rectangular cross section is inserted from one end to the other end of one of the plurality of slots 15 in the stator core 11 of the rotary electric machine 1 and the first lead wire 2A is inserted. A step of projecting the first end surface 27A of the above from the other end to the outside of the one slot 15 is included. Further, in the insertion step S1, a second lead wire 2B having a rectangular cross section is inserted from one end of another slot 15 different from the one slot 15 toward the other end, and the second end surface 27B of the second lead wire 2B is inserted. It includes a step of projecting from the other end to the outside of the other slot 15.
In the insertion step S1, as described above, the segment conductor 20 as shown in FIG. 3 is inserted into the slot 15 of the stator core 11 from the axial direction.

The bending step S3 is a step of arranging the first end surface 27A and the second end surface 27B projecting to the outside of the slot 15 side by side. In the bending step S3, as described above, one end 25 of the first segment conductor 20A and one end 25 of the second segment conductor 20B are brought close to each other, and one end 25 of the first segment conductor 20A is brought close to each other. And the end face 27 of one end 25 of the second segment conductor 20B are arranged next to each other.

The arranging step S5 is a step of arranging the covering member 40 so as to cover at least a part of the first end surface 27A and the second end surface 27B across the first end surface 27A and the second end surface 27B arranged adjacent to each other. In the arranging step S5, as described above, the covering member 40 is arranged across the two end faces 27 arranged adjacent to each other.

In the welding step S7, the covering member 40 arranged so as to straddle the first end surface 27A and the second end surface 27B is irradiated with an energy beam such as a laser beam to melt the entire covering member 40 and the covering member 40 and the first. This is a step of forming the connecting portion 57 by forming a molten layer 55 in which the end portion 25 of the first conducting wire 2A and the end portion 25 of the second conducting wire 2B are melted. In the welding step S7, as described above, by irradiating the covering member 40 arranged on the end face 27 with a laser beam, the end portion 25 is melted and connected together with the covering member 40.
The above-described method for manufacturing the stator of the rotary electric machine can efficiently manufacture the stator 10 of the rotary electric machine 1.

The above-mentioned connection method of the square lead wire can be summarized as follows.
In the method of connecting the square lead wires according to some embodiments, the first end surface 27A and the second end surface 27B straddle the first end surface 27A and the second end surface 27B in a state where the first end surface 27A and the second end surface 27B are adjacent to each other. The arrangement step S5 is included in which the covering member 40 is arranged so as to cover at least a part of the second end surface 27B. Further, in the method of connecting the square lead wire according to some embodiments, the covering member 40 arranged so as to straddle the first end surface 27A and the second end surface 27B is irradiated with an energy beam such as a laser beam to cover the covering member. The welding step S7 includes a welding step S7 in which the entire 40 is melted to form a molten layer 55 in which the covering member 40, the end portion 25 of the first lead wire 2A, and the end portion 25 of the second lead wire 2B are melted.
In the method of connecting the square lead wires according to some embodiments, the molten layer 55 described above is formed, so that the size of the connecting portion 57 can be secured. This makes it possible for a sufficient current to flow through the connection portion 57. Therefore, the reliability of the connection between the first lead wire 2A and the second lead wire 2B can be improved.
Further, in the method of connecting the square lead wire according to some embodiments, at least a part of the first end surface 27A and the second end surface 27B is covered with the covering member 40 across the first end surface 27A and the second end surface 27B. For example, even if the above-mentioned gap 17 is present, it is possible to prevent the irradiated laser beam from passing through the gap 17 and insufficiently forming the molten layer 55.
Further, according to the method of connecting the square lead wires according to some embodiments, it is possible to prevent the irradiated laser beam from passing through the gap 17 as described above, so that the output of the laser beam is unnecessary. It is not necessary to increase the performance to the maximum, and it is possible to prevent the performance required for the irradiation device for outputting the laser beam from becoming excessive.

In the method of connecting the square lead wires according to some embodiments, in the arrangement step S5, as shown in FIGS. 13 and 14, the first end face 27A and the second lead wire 2B extend with respect to the first end face 27A. The covering member 40 can also be arranged so as to straddle the second end surface 27B arranged at a position protruding in the direction.
Therefore, as shown in FIG. 14, even if the positions of the first end surface 27A and the second end surface 27B are deviated in the extending direction of the first lead wire 2A or the second lead wire 2B, the first end face 27A and the second end face 27B The molten layer 55 can be formed by irradiating the covering member 40 arranged so as to straddle the above with a laser beam.

In the method of connecting the square lead wires according to some embodiments, in the welding step S7, as shown in FIG. 12, the laser beam 51 is irradiated while scanning to melt the entire covering member 40 and cover member 40. And the end portion 25 of the first lead wire 2A and the end portion 25 of the second lead wire 2B may form a molten layer 55 in which the melted layer 55 is formed.
Thereby, the above-mentioned molten layer can be efficiently generated.

In the method of connecting the square lead wires according to some embodiments, in the welding step S7, a region of the covering member 40 in which the edge portion 27a of the first end surface 27A and the edge portion 27a of the second end surface 27B are adjacent to each other. A laser beam 51 is irradiated to the portion covering the cover member 40 to melt the entire covering member 40, and the molten layer 55 in which the covering member 40, the end portion 25 of the first lead wire 2A, and the end portion 25 of the second lead wire 2B are melted is formed. It may be generated.
As a result, it is possible to prevent the shape of the molten layer 55 described above from being different between the first lead wire 2A side and the second lead wire 2B side. That is, it is possible to prevent the shape of the molten layer 55 from becoming distorted, such as being biased toward either of the two end portions 25 of the first lead wire 2A and the second lead wire 2B.

In the method of connecting the square lead wires according to some embodiments, in the arrangement step S5, at least a part of the first end surface 27A and the second end surface 27B straddling the first end surface 27A and the second end surface 27B facing upward, respectively. It is preferable to arrange the covering member 40 so as to cover the above.
As a result, the need for temporarily fixing the arranged covering member 40 to the first lead wire 2A and the second lead wire 2B is reduced, and the labor and cost required for the temporary fixing can be suppressed.
For example, when the first end surface 27A and the second end surface 27B are facing downward, in the arrangement step S5, the covering member 40 arranged across the first end surface 27A and the second end surface 27B is placed on the first lead wire 2A. It may be temporarily fixed to the second lead wire 2B.

In the method of connecting the square lead wires according to some embodiments, in the arrangement step S5, the covering member 40 having the plate thickness of the end facing portion 41 of 0.1 mm or more and 0.5 mm or less is attached to the first end surface 27A and the second end surface 27A. It may be arranged so as to straddle the end face 27B.

As a result of diligent studies by the inventors, if the plate thickness of the end facing portion 41 is 0.1 mm or more, a gap 17 is assumed between the end portion 25 of the first lead wire 2A and the end portion 25 of the second lead wire 2B. It was found that even in the presence of the laser beam, it is possible to prevent the irradiated laser beam from penetrating the covering member 40 and passing through the gap 17. Further, as a result of diligent studies by the inventors, if the plate thickness of the end facing portion 41 is 0.5 mm or less, the time required to form the above-mentioned molten layer 55 hardly changes depending on the presence or absence of the covering member 40. It turned out.
Therefore, according to the method of connecting the square lead wires according to some embodiments, the above-mentioned molten layer 55 can be efficiently generated.

In the method of connecting the square lead wires according to some embodiments, in the arrangement step S5, the covering member 40 having the same material as the first lead wire 2A and the second lead wire 2B is formed into the first end face 27A and the second end face 27B. It is good to place them across.
As a result, the composition of the molten layer 55 becomes the same as that of the first lead wire 2A and the second lead wire 2B, so that the influence on the electrical characteristics can be suppressed.

In the method of connecting the square lead wires according to some embodiments, in the arrangement step S5, the covering member 40 whose material is different from that of the first lead wire 2A and the second lead wire 2B is the first end face 27A and the second end face 27B. It may be arranged across.
Thereby, for example, if the covering member 40 is made of a material whose absorption rate of the laser beam is higher than that of the first lead wire 2A and the second lead wire 2B, the molten layer 55 can be efficiently generated.

In the method of connecting the square lead wires according to some embodiments, in the arrangement step S5, the first end surface 27A of the first lead wire 2A having a length of one side of the rectangular cross section of 1 mm or more and 5 mm or less and one side of the rectangular cross section. The covering member 40 may be arranged so as to straddle the second end surface 27B of the second lead wire 2B having a length of 1 mm or more and 5 mm or less.

In the method of connecting the square lead wire according to some embodiments, in the insertion step S1, a rectangle is formed from one end to the other end of one of the plurality of slots 15 in the stator core 11 of the rotary electric machine 1. It is preferable to include a step of inserting the first lead wire 2A having a cross section and projecting the first end surface 27A of the first lead wire 2A from the other end to the outside of the one slot 15. Further, in the method of connecting the square lead wire according to some embodiments, in the insertion step S1, the second lead wire having a rectangular cross section from one end to the other end of another slot 15 different from the one slot 15. It is preferable to include a step of inserting the 2B and projecting the second end surface 27B of the second lead wire 2B from the other end to the outside of the other slot 15.
Such a method of connecting the square lead wire can efficiently connect the windings of the stator of the rotary electric machine.

The present invention is not limited to the above-described embodiment, and includes a modified form of the above-described embodiment and a combination of these embodiments as appropriate.
For example, the method of connecting the square lead wires according to some of the above-described embodiments may be applied to the connection of the lead wires other than the square lead wire 2 of the rotary electric machine 1.
Further, in some of the above-described embodiments, for example, as shown in FIG. 7, the covering member 40 straddles the first end surface 27A and the second end surface 27B and covers the entire first end surface 27A and the second end surface 27B. There is. However, in some embodiments, the covering member 40 does not necessarily cover the entire first end face 27A and second end face 27B, and the laser beam 51 can be prevented from coming out of the gap 17 described above. For example, it suffices to cover at least a part of the first end surface 27A and the second end surface 27B.

1 Rotating electric machine 2 Square wire (square lead wire)
2A 1st conductor 2B 2nd conductor 10 Stator 11 Stator iron core 13 Stator winding 15 Slot 20 Segment conductor 20A 1st segment conductor 20B 2nd segment conductor 25 End 27 End face 27A 1st end face 27B 2nd end face 40 Cover Member 41 End facing part 43 Side facing part 51 Laser beam 55 Melted layer 57 Connection part

Claims (12)

With the first end face of the first lead wire having a rectangular cross section and the second end face of the second lead wire having a rectangular cross section adjacent to each other, the first end face and the first end face straddling the first end face and the second end face. A step of arranging the covering member so as to cover at least a part of the second end surface, and
An energy beam is applied to the covering member arranged so as to straddle the first end surface and the second end surface to melt the entire covering member, and the covering member, the end portion of the first lead wire, and the first lead wire are melted. 2 Steps to form a molten layer in which the ends of the conductors are melted,
How to connect a square lead wire. The step of arranging the covering member faces the first end face and the end facing portion formed so as to face the second end face, and at least a part of the side surface of the first lead wire and the second lead wire. The square shape according to claim 1, wherein the covering member having the side facing portion formed as described above is arranged so that the end facing portion covers at least a part of the first end surface and the second end surface. How to connect the leads. In the step of arranging the covering member, the covering member is straddled between the first end surface and the second end surface arranged at a position protruding from the first end surface in the extending direction of the second conducting wire. The method for connecting a square lead wire according to claim 1 or 2 to be arranged. In the step of forming the molten layer, the energy beam is irradiated while scanning to melt the entire covering member, and the covering member, the end portion of the first lead wire, and the end portion of the second lead wire are formed. The method for connecting a square lead wire according to any one of claims 1 to 3, wherein a molten molten layer is generated. In the step of forming the molten layer, the energy beam is applied to a portion of the covering member that covers a region where the edge portion of the first end surface and the edge portion of the second end surface are adjacent to each other. The angle according to any one of claims 1 to 3, wherein the entire covering member is melted to form a molten layer in which the covering member, the end portion of the first lead wire, and the end portion of the second lead wire are melted. How to connect the mold lead wire. A claim in which the step of arranging the covering member is to arrange the covering member so as to cover at least a part of the first end surface and the second end surface so as to straddle the first end surface and the second end surface facing upward, respectively. The method for connecting a square lead wire according to any one of 1 to 5. In the step of arranging the covering member, the covering member having a plate thickness of 0.1 mm or more and 0.5 mm or less at the end facing portion formed so as to face the first end face and the second end face is said to be the first. The method for connecting a square lead wire according to any one of claims 1 to 6, which is arranged so as to straddle one end surface and the second end surface. The step of arranging the covering member is any one of claims 1 to 7 in which the covering member having the same material as the first conducting wire and the second conducting wire is arranged so as to straddle the first end surface and the second end surface. The method for connecting the square lead wire according to the first item. The step of arranging the covering member is any one of claims 1 to 7 in which the covering member whose material is different from that of the first conducting wire and the second conducting wire is arranged so as to straddle the first end surface and the second end surface. The method for connecting a square lead wire according to item 1. In the step of arranging the covering member, the length of one side of the rectangular cross section is 1 mm or more and 5 mm or less, and the length of one side of the first conducting wire is 1 mm or more and 5 mm or less. The method for connecting a square lead wire according to any one of claims 1 to 9, wherein the covering member is arranged so as to straddle the second end surface of the second lead wire. The first lead wire is inserted from one end of one of the plurality of slots in the stator core of the rotary electric machine toward the other end, and the first end surface protrudes from the other end to the outside of the one slot. Steps to make and
A step of inserting the second lead wire from one end of another slot different from the one slot toward the other end to project the second end surface from the other end to the outside of the other slot.
A step of arranging the first end face and the second end face projecting to the outside of the slot next to each other,
With more
The method for connecting a square lead wire according to any one of claims 1 to 10, wherein the step of arranging the covering member is performed after performing the step of arranging the covering members next to each other. A first lead wire having a rectangular cross section is inserted from one end of one slot of a plurality of slots in a stator core of a rotary electric machine toward the other end, and the first end surface of the first lead wire is inserted from the other end. Steps to project outside one slot,
A second lead wire having a rectangular cross section is inserted from one end of another slot different from the one slot toward the other end, and the second end surface of the second lead wire is moved from the other end to the outside of the other slot. Steps to protrude and
A step of arranging the first end face and the second end face projecting to the outside of the slot next to each other,
A step of arranging a covering member so as to cover at least a part of the first end face and the second end face straddling the first end face and the second end face arranged adjacent to each other.
An energy beam is applied to the covering member arranged so as to straddle the first end surface and the second end surface to melt the entire covering member, and the covering member, the end portion of the first lead wire, and the first lead wire are melted. 2 Steps to form a molten layer in which the ends of the conductors are melted,
A method for manufacturing a stator of a rotary electric machine.