JP2019097326A - Stator coil and method of forming lead portion of the same - Google Patents

Abstract

To provide a stator coil including a conductor segment that can secure an insulation distance from another conductor segment when mounted on a stator core and can suppress insulation failure due to floating of an insulation film.SOLUTION: The stator coil includes a plurality of conductor segments consisting of flat wire. An end 12a of a lead portion of each of the conductor segments is provided with a bent portion 20 bent in a direction away from a stator core in an axial direction when mounted on the stator core, and partially cut away. An insulation film on an inner circumferential side of the bent portion 20 in the bending direction is cut off, and a laser irradiation surface 36 is formed when the bent portion 20 is cut into a pseudo arc shape and the conductor segments are joined together. When the conductor segments are joined to each other, an insulating coating on a joint surface 38 in contact with the other conductor segments is peeled off on a surface different from the laser irradiation surface 36.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a stator coil of a rotating electrical machine and a method of forming a lead portion thereof.

  Conventionally, there have been proposed stator coils formed by inserting a large number of U-shaped conductor segments into slots of a stator core of a rotating electrical machine and sequentially joining them.

  In Patent Document 1, a continuous flat wire is bent at a desired position to form a bent portion, the wire is cut at the bend portion to cut out a conductor segment, and the cut out conductor segment is bent in a U shape, A method of forming a conductor segment is disclosed. By cutting the conducting wire at the bending portion, an axially outward bending portion of the stator core when mounted on the stator core is formed at the end of the lead portion of the conductor segment. When a large number of U-shaped conductor segments are mounted on a stator core to form a stator coil by a bent portion, the distance between the stator core and another conductor segment adjacent in the axial direction is increased, and an insulation distance is secured. .

JP, 2017-85701, A

  When the conductor segment is provided with a bend, the bent portion is stressed. In particular, on the inner side of the bent portion (on the side where the radius of curvature is small), the volume of the conducting wire decreases with bending, and the adhesion of the insulating coating decreases. In such a portion where the adhesion of the insulating film is lowered, the heat of bonding the lead portions of the conductor segments with a laser may cause floating of the insulating film, which causes insulation failure.

  On the other hand, it is desirable to provide a bent portion in a conductor segment to make a distance from another conductor segment to secure an insulation distance.

  An object of the present invention is to provide a stator coil provided with a conductor segment which can secure insulation distance from another conductor segment when mounted on a stator core and can suppress insulation failure due to floating of an insulating film. It is to do.

  The stator coil according to the present invention is a stator coil including a plurality of conductor segments composed of flat rectangular conductors, and is directed away from the stator core in the axial direction when the conductor segments are mounted on the stator core at the ends of the lead portions of the conductor segments. A bent portion which is bent and partially cut is provided, the insulating film on the inner peripheral side in the bending direction of the bent portion is cut, and the bent portion is cut into a pseudo arc shape. A laser irradiation surface at the time of bonding the conductor segments is formed, and when the conductor segments are bonded, the insulating film on the bonding surface in contact with the other conductor segments is peeled off in a surface different from the laser irradiation surface. Are characterized.

  In the stator coil of the present invention, it is also preferable that the insulating coating remains on a part of the outer bent portion of the bent portion.

  In the stator coil of the present invention, it is preferable that the region of the joint surface where the insulating film is peeled off be located at a predetermined distance from the outer bent portion of the bent portion.

  The method for forming a lead portion of a stator coil according to the present invention is a method for forming a lead portion of a stator coil including a plurality of conductor segments consisting of flat rectangular conductors, and the conductor segment is mounted on the stator core at the end of the lead portion of the conductor segment. Bending process which bends in a direction away from the stator core in the axial direction to form a bent portion, cuts out the insulating film on the inner bent portion of the bent portion, and cuts out the bent portion in a pseudo arc shape And a peeling step of peeling an insulating film on a joint surface in contact with another conductor segment when the conductor segments are joined, and a part of the bent portion is formed by the cutting step to form the conductor segment A laser irradiation surface at the time of joining together is formed, It is characterized by the above-mentioned.

  In the method for forming a lead portion of a stator coil according to the present invention, it is also preferable that an insulating film is left on a part of the outer bent portion of the bent portion in the cutting step.

  In the method for forming a lead portion of a stator coil according to the present invention, the bending step is performed by pressing a predetermined position of the end portion of the lead portion of the conductor segment with a jig, and the bending portion is cut in the cutting step. It is preferable that the portion to be formed includes the contact portion between the conductor segment and the jig in the bending step.

  In the method for forming a lead portion of a stator coil according to the present invention, in the peeling step, the region where the insulating film is peeled off of the joint surface is a position separated from the outer bending portion of the bending portion by a predetermined distance. It is suitable.

According to the present invention, when the conductor segment is mounted on the stator core, the insulation distance from the other conductor segment can be secured by providing the bent portion in the conductor segment.
By cutting off the insulating film on the inside of the bent portion where floating of the insulating film is likely to occur, it is possible to suppress the occurrence of insulation failure when mounted on the stator core.

It is a flowchart which shows the procedure of the process of forming a stator coil. It is a side view which shows the conductor segment cut out. It is a figure which shows a mode that a bending part is formed in the edge part of the lead part of a conductor segment. It is a figure which shows a mode that a part of bending part is cut away. It is a perspective view which shows the edge part of the lead part from which a part of bending part was cut away. It is a side view which shows the state from which the insulating film of the joint surface peeled. It is a schematic diagram which shows a mode that a U-shaped conductor segment is inserted in the slot of a stator core. It is a side view of a stator core which shows the state which turned over the lead part of a plurality of conductor segments in the peripheral direction of a stator core. It is a perspective view which shows the edge part of the lead part of two conductor segments joined. It is a side view which shows the lead part of the several conductor segment mounted in the stator core. It is the side view which expanded the area | region enclosed with the broken line of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The conductor segment which concerns on this embodiment comprises the stator coil of rotary electric machine. A large number of U-shaped conductor segments are inserted into the slots of the stator core, and the ends of their lead portions are joined sequentially to form a stator coil. The rotary electric machine includes a stator having a stator core on which a stator coil is wound, and a rotor provided on the inner circumferential side of the stator. The rotary electric machine is mounted, for example, on an electric vehicle such as a hybrid car or an electric car and used as a motor and a generator.

  Here, a method of forming the stator coil according to the present embodiment will be described. FIG. 1 is a flow chart showing the procedure of the step of forming a stator coil, wherein S100 to S108 are the procedure of the step of forming a conductor segment, and the steps of S110 to S114 are a step of forming a stator coil using a plurality of them. It is. The conductor segment of the present embodiment is characterized by the end portion of its lead portion, which will be described in detail below with reference to the flow of FIG.

  First, in S100 of FIG. 1, for example, the conducting wire wound around a bobbin or the like is drawn out, and the drawn conducting wire is straightly drawn out using a roller or the like. The conducting wire is a flat rectangular conducting wire, and the flat conducting wire is formed by applying an insulating covering around a metal (conductor) such as copper having high conductivity. For insulating insulation, resin such as highly insulating enamel is used.

  Next, the straightened lead wire is cut out with a length constituting one conductor segment to obtain a straight conductor segment. FIG. 2 is a side view showing the conductor segment 10 cut out. As shown in FIG. 2, at both ends of the conductor segment 10, there are lead portions 11a and 11b which are portions projecting from the end face of the stator core when the conductor segment 10 is U-shaped and inserted into the slot of the stator core. Further, as shown by dashed lines in FIG. 2, there are end portions 12a and 12b of the lead portions which are tip portions of the respective lead portions 11a and 11b.

  Next, in S102 of FIG. 1, the end portions 12a and 12b (ends of the flat wire) of the lead portion are bent to form a bent portion at the end portions 12a and 12b of the lead portion (bending step). FIG. 3 is a view showing how a bent portion 20 is formed at the end 12 a of the lead portion of the conductor segment 10. Although the process for the end 12a of one lead portion will be described below with reference to FIGS. 3 to 6, the same process is performed symmetrically on the end 12b of the other lead portion. As shown in FIG. 3, the conductor segment is sandwiched and fixed by the clamp 14, and a bending portion 20 is formed on the end 12 a of the lead by pressing a predetermined position of the end 12 a of the lead with a pressing jig 18. Form Specifically, when the conductor segment is mounted on the stator core, the bent portion 20 is formed such that the end 12a of the lead portion is bent outward in the axial direction of the stator core. In other words, when the conductor segment is mounted on the stator core, the bent portion 20 is formed such that the end 12a of the lead portion is bent in the direction away from the stator core in the axial direction. As a result, as will be described later, when the conductor segment is mounted on the stator core, the insulation distance from other conductor segments adjacent in the axial direction of the stator core is secured.

  Next, in S104 of FIG. 1, a part of the bending portion 20 is cut off (cut-off step). FIG. 4 is a view showing how a part of the bending portion 20 is cut away. The upper side of FIG. 4 shows the state before excising the bending portion 20, and the position of excising is shown by a dashed dotted line, and the lower side shows the state after excising the bending portion 20 , The resected range PR is shown. By this process, as shown in FIG. 4, the insulating coating on the inside 22 of the bent portion (inward bent portion of the bent portion) is cut off, and the bent portion 20 is cut in a pseudo arc shape. In other words, the insulating coating on the inner peripheral side of the bending portion 20 in the bending direction is cut off, and the bending portion 20 is cut in a pseudo arc shape. In this way, the insulating film in a part of the bent portion and the conductor inside are cut off.

  By forming the bent portion, the volume of the conducting wire becomes smaller and the adhesion of the insulating film is reduced on the inner side 22 of the bent portion, and the portion where the adhesion of such insulating film is reduced is the lead of the conductor segment The heat generated when the end portions of the portions are joined with a laser causes floating of the insulating film, which causes insulation failure. However, the conductor segment of this embodiment can prevent this problem from occurring because the insulation film on the inner side 22 of the bent portion is cut off as described above.

  As described above, when the bent portion 20 is cut into a pseudo arc shape, a part of the bent portion 20 is formed to form a laser irradiation surface when joining the end portions of the lead portions of the conductor segments. FIG. 5 is a perspective view of the end 12a of the lead portion of the conductor segment in which a part of the bent portion 20 is cut away. In FIG. 5, a region (conductor exposed region 30) in which the internal conductor is exposed by cutting off the bent portion 20 with diagonal lines is shown, and a laser irradiation surface 36 is shown surrounded by a broken line.

In this cutting step, the portion where the bent portion is cut includes a portion (contact portion) where the pressing jig 18 is in contact with the flat wire in the step of forming the bent portion (bending step). When the pressing jig 18 contacts the flat wire, there is a possibility that the insulating film of the contacting portion may be damaged, and in this case, the conductor segment may cause insulation failure when mounted on the stator core.
However, in the present embodiment, since the insulating film of the contact portion is cut off and the damaged insulating film does not remain on the conductor segment, the insulation failure is prevented.

  Further, as shown in the lower side of FIG. 4 and FIG. 5, in this cutting process, the insulating film remains on a part of the outer side 24 (outer bending portion of the bending portion) of the bending portion. Thus, as will be described later, when the conductor segment is mounted on the stator core, insulation with other conductor segments adjacent in the axial direction of the stator core is secured.

  Returning to FIG. 1, the description of the process of forming the conductor segment 10 will be continued. After S104, in S106, when the conductor segments are joined, the insulating film on the joining surface in contact with the other conductor segment is peeled off on a surface different from the laser irradiation surface 36 (peeling step). FIG. 6 is a side view showing a state in which the insulating film on the bonding surface 38 is peeled off. As shown in FIG. 6, the region (peeling region 40) of the bonding surface 38 where the insulating film is peeled off is located at a predetermined distance from the outer bending portion 24 of the bending portion. As a result, as will be described later, when the conductor segment is mounted on the stator core, an insulation distance from another conductor segment adjacent in the axial direction of the stator core is secured.

  Next, in S108 of FIG. 1, the conductor segment 10 is bent in a U-shape. FIG. 7 shows a conductor segment 10 bent in a U-shape. The steps S100 to S108 described above are the process of forming the conductor segment.

  Next, steps (S110 to S114) of forming a stator coil using a plurality of conductor segments formed in the steps of S100 to S108 will be described. In addition, since the formation process of this stator coil is the same as that of a prior art (for example, patent document 1), it simplifies and demonstrates.

  At S110, two legs of each of the plurality of U-shaped conductor segments 10 are inserted into the slots of the stator core (assembly step). FIG. 7 shows how the two legs 13 of one U-shaped conductor segment 10 are inserted into the slots of the stator core. In FIG. 7, the stator core 42 is drawn small. The stator core 42 is formed in an annular shape, and a plurality of slots are formed parallel to the central axis thereof. In this process, each conductor segment 10 is assembled to the slot of the stator core 42 by inserting the two legs 13 of each U-shaped conductor segment 10 into the slot of the stator core.

  Next, in S112, the lead portions of the conductor segments 10 protruding from the end face of the stator core are tipped down in the circumferential direction of the stator core (step-down step). FIG. 8 is a side view of the stator core 42 showing a state in which the lead portions 11 of the conductor segments 10 are turned in the circumferential direction of the stator core 42. As shown in FIG. For example, this causes the lead portions 11 of the outermost conductor segments 10 to fall in the circumferential direction and counterclockwise direction, and the lead portions 11 of the conductor segments 10 adjacent in the radial direction to the circumferential direction and clockwise direction Further, the lead portions 11 of the conductor segments 10 adjacent to the radially inner side of these radially inwards are turned over while alternately changing the direction, such as falling in the circumferential direction and counterclockwise direction. The tipping of the lead portion 11 of the conductor segment 10 is performed using, for example, an annular coil end bending jig.

  Next, in S114, the ends of the lead portions of the corresponding conductor segments adjacent in the radial direction of the stator core are joined (joining step). FIG. 9 is a perspective view showing the end 12 of the lead of two conductor segments to be joined. In this bonding step, the laser is applied to the laser-irradiated surface 36 in which the internal conductor is exposed, with the bonding surfaces of the end portions 12 of the lead portions of the adjacent conductor segments in close contact and the peeling regions of the bonding surfaces in close contact. The end portions 12 are joined by irradiation and welding (laser welding). The laser irradiation surface 36 is formed in a pseudo arc shape (R-shaped) by the cutting process (S104 in FIG. 1). Therefore, as shown in FIG. 9, when the bonding surfaces of the two conductor segments are brought into intimate contact, the two laser irradiation surfaces 36 form one curved laser irradiation surface having substantially no difference in level. By laser-irradiating the formed one laser-irradiated surface, the two end portions 12 are securely bonded without causing a bonding failure.

  The stator coil is formed by the flow of FIG. 1 described above. In the stator coil thus formed, a portion (leads 11 of the plurality of conductor segments 10) protruding from the end face of the stator core is a lead of the stator coil. Next, the function and effect of the stator coil of the present embodiment will be described.

  FIG. 10 is a side view showing the lead portions 11 of a plurality of conductor segments mounted on the stator core 42, and FIG. 11 is an enlarged side view of a region surrounded by a broken line in FIG. In FIG. 11, the outline of the peeling area 40 in the bonding surface, which is the side surface opposite to the visible side surface, is indicated by an imaginary line (one-dot chain line). As shown in FIGS. 10 and 11, when the conductor segments are mounted on the stator core, the lead portions 11 of the conductor segments are adjacent to each other in the axial direction of the stator core. Therefore, it is necessary to ensure insulation with the lead portions 11 of other conductor segments adjacent in the axial direction.

  The conductor segment 10 constituting the stator coil of the present embodiment has a bent portion formed at the end 12 of the lead portion. Therefore, as shown in FIG. 11, an air gap 50 is generated between the lead portions 11 of the other conductor segments adjacent in the axial direction, and the insulation distance between the lead portions 11 of the other conductor segments can be secured. Further, according to the conductor segment 10 of the present embodiment, as shown in FIG. 11, since the insulating coating remains on the outer bent portion 24 of the bent portion, the leads of other conductor segments adjacent in the axial direction It is possible to secure insulation with the part. Furthermore, according to the conductor segment 10 of the present embodiment, since the peeling region 40 of the joint surface 38 is at a position separated by a predetermined distance from the outer bending portion 24 of the bending portion, the other conductor segments adjacent in the axial direction A large insulation distance with the lead portion of the As described above, the conductor segment 10 of the present embodiment has a configuration in which insulation measures against the other adjacent conductor segments are performed synergistically, and insulation with the other conductor segments can be reliably ensured.

  Moreover, the conductor segment 10 which comprises the stator coil of this embodiment is stressed by having formed the bending part, and the insulation film inside the bending part which adhesive force fell is cut off. Therefore, in the conductor segment 10 of the present embodiment, the insulation film having such reduced adhesion is left on the conductor segment, so that the insulation film is reduced in adhesion due to heat when joining the end portions with a laser. And insulation failure does not occur. Thus, the stator coil of this embodiment and the conductor segment 10 which comprises a stator coil are what has high insulation.

  DESCRIPTION OF SYMBOLS 10 conductor segment, 11, 11a, 11b lead part, 12, 12a, 12b end part of lead part, 13 legs, 14 clamps, 18 pressing jigs, 20 bending parts, 22 inside of bending parts (inward bending of bending parts Part), 24 outside of bending part (outside bending part of bending part), 26 inside starting point of bending part, 28 outside starting point of bending part, 30 conductor exposed area, 36 laser irradiated surface, 38 bonding surface, 40 peeling area, 42 stator cores, 50 air gaps.

Claims (7)

A stator coil comprising a plurality of conductor segments consisting of a flat wire, comprising:
The end of the lead portion of the conductor segment is provided with a bent portion which is bent in a direction away from the stator core in the axial direction when the conductor segment is mounted on the stator core, and a partially cut bent portion
The insulating coating on the inner peripheral side in the bending direction of the bent portion is cut off, and the bent portion is cut into a pseudo arc shape to form a laser irradiation surface when bonding the conductor segments together,
When the conductor segments are joined, the insulating film on the joining surface in contact with the other conductor segments is peeled off in a plane different from the laser irradiation plane.
Stator coil characterized by. The stator coil according to claim 1, wherein
An insulating film remains on a part of the outside bent part of the bent part,
Stator coil characterized by. The stator coil according to claim 1 or 2, wherein
The region of the bonding surface where the insulating film is peeled off is located at a predetermined distance from the outer bending portion of the bending portion.
Stator coil characterized by. A method of forming a lead portion of a stator coil comprising a plurality of conductor segments consisting of a flat wire,
Bending the ends of the lead portions of the conductor segments in a direction away from the stator core in the axial direction when the conductor segments are mounted on the stator core to form a bend;
A cutting step of cutting the insulating film of the inward bending portion of the bending portion and cutting the bending portion into a pseudo arc shape;
And a peeling step of peeling an insulating film on a joint surface in contact with another conductor segment when the conductor segments are joined.
By the cutting step, a part of the bent portion is formed to form a laser irradiation surface when the conductor segments are joined to each other.
A method of forming a lead portion of a stator coil, characterized in that: 5. The method for forming a lead portion of a stator coil according to claim 4, wherein
In the cutting step, an insulating film is left on a part of the outer bent portion of the bent portion.
A method of forming a lead portion of a stator coil, characterized in that: A method of forming a lead portion of a stator coil according to claim 4 or 5, wherein
The bending step is performed by pressing a predetermined position of the end of the lead portion of the conductor segment with a jig,
The portion where the bent portion is cut off in the cutting step includes the contact portion between the conductor segment and the jig in the bending step.
A method of forming a lead portion of a stator coil, characterized in that: A method of forming a lead portion of a stator coil according to any one of claims 4 to 6, wherein
In the peeling step, a region where the insulating film on the bonding surface is peeled is a position separated from the outer bent portion of the bent portion by a predetermined distance.
A method of forming a lead portion of a stator coil, characterized in that: