JP2013236523A - Assembled conductor wire, coil formed by processing the same, and process of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an assembled conductor wire capable of forming a coil in high precision even when undergoing a bending process with a small bending radius.SOLUTION: An assembled conductor wire 50 is formed by arranging mutually in parallel a plurality of element conductor wires having rectangular cross-sections and integrating the conductor wires, wherein the element conductor wires are welded at positions 21a that is an end of a bending part 22 for forming a segment coil 20 to 21k. The process of manufacturing the coil includes steps of: collectively arranging mutually in parallel the plurality of element conductor wires having rectangular cross-sections and forming the integrated assembled conductor wire 50; welding the element conductor wires at an end of the bending part for forming the coil; and performing a process of bending into a coil shape.

Description

  The present invention relates to a structure of an assembly conductor, a structure of a coil obtained by processing the assembly conductor, and a method for manufacturing the coil.

  In recent years, vehicles driven by motors such as hybrid vehicles and electric vehicles have been frequently used. Since motors mounted on these electric vehicles are required to be small and have high output, embedded permanent magnet synchronous motors (IPMSMs) in which permanent magnets are embedded in a rotor are often used. A stator core of an embedded permanent magnet synchronous motor (IPMSM) is provided with a plurality of concave portions (slots) and convex portions that are alternately formed on the inner peripheral wall in the circumferential direction. In each slot, a conductor wire such as an enamel wire constituting a coil is disposed. Since the slot has a square cross section, when a conductor wire having a circular cross section is arranged in the slot, a gap is formed between the slot and the conductor wire, so that the filling rate of the conductor wire of the slot becomes low, and the motor There has been a problem that the output with respect to the size of the outer shape of the device becomes small.

In recent years, motors for electric vehicles such as hybrid vehicles are often driven by high-frequency alternating current generated by an inverter. Therefore, if there is a gap between the slot and the conductor wire due to the skin effect, the motor flows in the conductor wire. There is a problem that the current is concentrated near the surface of the conductor wire and the AC resistance increases.

  Therefore, in order to increase the filling factor of the conductor wire inside the slot, that is, the conductor cross-sectional area (conductor space factor) occupying the predetermined cross-sectional area of the slot, and to reduce the AC effect due to the skin effect and eddy current, It has been proposed to use a set conducting wire in which a plurality of strands of a cross section are gathered so that the overall cross-sectional shape is a rectangle (see, for example, Patent Document 1). In Patent Document 1, a coating layer such as an oxide film is formed on the surface of a strand having a rectangular cross section, and a plurality of strands having a rectangular cross section are bonded by providing a binding layer (adhesive layer) between the coating layers. As a whole, it is described that the conductive wire has a rectangular cross section.

  Also, a heat-sealing layer (insulating layer) is formed on the surface of the coating layer, and a plurality of strands are aligned in a non-twisted state so as to have a rectangular cross section as a whole, and heated to about 200 ° C. The heat-bonding layers of adjacent wires are fused together to form a collective conducting wire, and a PTFE tube is placed on the outside, and the tube is thermally contracted by heating to 330 ° C. to 340 ° C. A collective conducting wire in which a coating layer is formed has been proposed (see, for example, Patent Document 2). The assembly conductor described in Patent Document 2 can suppress damage when the assembly conductor is inserted into the slot of the stator core by configuring the outer peripheral coating layer with a material having a small frictional resistance.

JP 2007-227266 A JP 2008-193860 A

  By the way, when the motor of an electric vehicle is reduced in size, it becomes a big factor to make the size of a coil end small. In order to reduce the size of the coil end, it is necessary to bend the conductor wire with a small bending radius at the portion where the conductor wire protrudes from the slot of the stator core to the end surface, and to reduce the protruding amount of the coil end from the end surface of the stator core. .

  However, as described in Patent Documents 1 and 2, the collective conducting wire in which the strands are integrated by bonding is a difference in bending radius between the outer peripheral side and the inner peripheral side when bending with a small bending radius. Alternatively, a large shearing force acts between the strands due to the difference in the length of the bent portions, and the adhesive between the strands peels off due to this shearing force, and the coil cannot be accurately formed with a small bending radius. was there.

  Accordingly, an object of the present invention is to provide a collective conducting wire that can form a coil with high accuracy even if it is bent with a small bending radius.

  The collective conducting wire of the present invention is an integrated collective conductor in which a plurality of conductor strands having a rectangular cross section are arranged in parallel to each other, and the conductor strands are welded at the end of a bent portion for forming a coil. It is characterized by that.

  In the collective conducting wire of the present invention, the welding is preferably performed by welding all around the outer circumference of the collective conducting wire, and the collective conducting wire is integrated with each conductor strand so as to have a rectangular cross section, Is preferably a unidirectional welding in which the surfaces of the conductor strands in contact with each other are welded in one direction intersecting the longitudinal direction of each conductor strand, and the welding is a rectangular cross section of the collective conductor It is also preferable that the welding is one-way welding toward the long side direction or the short side direction, and the bending portion is also preferably a bending portion configured to form a coil end.

  The coil of the present invention is a coil in which a plurality of conductor strands having a rectangular cross section are arranged in parallel to each other, and the integrated assembly conductor is bent. The assembly conductor is at the end of the bent portion for forming the coil. The conductor strands are welded together.

  In the coil of the present invention, the welding is also preferable as the entire circumference welding of the outer periphery of the assembly conductor, and the assembly conductor is integrated with each conductor wire so as to have a rectangular cross section, Welding is also preferable as unidirectional welding in which the surfaces of the conductor strands in contact with each other are welded in one direction intersecting the longitudinal direction of the conductor strands. It is also preferable that it is a unidirectional welding toward the long side direction or the short side direction of the cross section, and that the bending portion is also a bending portion configured to form a coil end. .

  The coil manufacturing method of the present invention includes a step of arranging a plurality of rectangular strands of conductor wires in parallel to each other to form an integrated conductor wire, and connecting the conductor wires at the end of a bent portion for forming the coil. A step of welding, and a step of bending the coil into a shape of a coil.

  In the coil manufacturing method of the present invention, the welding step may be preferably performed by welding the outer circumference of the collective conducting wire all around, and the step of forming the collective conducting wire includes the conductor wires integrated so as to have a rectangular cross section. And the step of welding is preferably performed as one-way welding toward the one direction intersecting the longitudinal direction of each conductor strand between the surfaces where each conductor strand is in contact, and the step of welding is It is also preferable to perform unidirectional welding toward the long side direction or the short side direction of the rectangular cross section of the assembly conductor, and the bending portion is a bending portion configured to form a coil end, The step of bending the coil into the shape of the coil is a step of bending the coil into a substantially U shape. After bending the coil, the step of inserting the straight portion into the slot of the stator core is performed. And a step of bending a portion protruding from the end face of the stator core, and further comprising the step of welding, wherein the step of welding further includes a bent portion end on the opposite side across the bent portion from the stator core side. It is also suitable as including welding of these.

  The present invention has an effect that it is possible to provide a collective conducting wire capable of forming a coil with high accuracy even when bending with a small bending radius.

It is a top view of the stator incorporating the assembly conducting wire or coil in the embodiment of the present invention. It is a side view of the stator incorporating the assembly conducting wire or coil in the embodiment of the present invention. It is explanatory drawing which shows the manufacturing process of the assembly conducting wire in embodiment of this invention. It is explanatory drawing which shows the welding of the assembly conducting wire in embodiment of this invention. It is explanatory drawing which shows the process of bending the assembly conducting wire in embodiment of this invention to a segment coil. It is an enlarged view of the A section shown in FIG. It is BB sectional drawing shown in FIG. It is explanatory drawing which shows the manufacturing process of the assembly conducting wire in other embodiment of this invention. It is explanatory drawing which shows the welding of the assembly conducting wire in other embodiment of this invention. It is explanatory drawing which shows the manufacturing process of the assembly conducting wire in other embodiment of this invention. It is explanatory drawing which shows the welding of the assembly conducting wire in other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Before describing the collective conducting wire or coil of the present invention, a stator incorporating the collective conducting wire or coil of the embodiment of the present invention will be described.

  As shown in FIG. 1, the stator 10 of the motor 100 includes a stator core 11 in which thin electromagnetic steel plates are laminated, a slot 12 formed in an inner peripheral wall 15 of the stator core 11, and a tooth 13 between the slots 12. A plurality are provided alternately in the direction. In each slot 12, a plurality of segment coils 20 having a square cross section constituting a stator coil are arranged in a line.

  As shown in FIG. 2, each segment coil 20 is bent into a substantially U shape, and then inserted into the slot 12 from the open end side of the U shape toward the thickness direction of the stator core 11 (motor axial direction). Is done. In the embodiment shown in FIG. 2, the substantially U-shaped segment coil 20 is inserted upward as indicated by an arrow 60 in the lower side of FIG. 2. As will be described later, the segment coil 20 is a collective conducting wire in which conductor wires having a rectangular cross section are integrated. The surfaces of the conductor wires are bonded together by an adhesive 53, and the reference numeral 21a in FIG. To 21k so as to prevent the conductor wires from being separated from each other at the site indicated by 21k.

  As shown in FIG. 2, the linear portion that protrudes in the axial direction of the motor (in the direction of the arrow 60 in FIG. 2) from the end face of the stator core 11 of the segment coil 20 inserted into the slot 12 is indicated by a dashed line in FIG. 2. After being bent into the shape as shown, the tips of adjacent segment coils 20 are welded together to form coil ends.

  As described above, since the segment coil 20 is attached to the stator 10 and the coil end is molded, when the height dimension of the stator 10 in the axial direction (the direction of the arrow 60 in FIG. 2) is reduced, the segment It is necessary to reduce the bending radius of the lower bending portion 22 of the coil 20 or the upper bending portion 32 to be bent after the segment coil 20 is inserted into the slot 12. Next, the collective conducting wire of the present invention that can form the coil with high accuracy even if the bending portions 22 and 32 are processed with a small bending radius will be described with reference to FIGS.

  FIG. 3 shows a process in which a plurality of copper strands 51 having a square cross section are assembled and integrated into a collective conducting wire 50. First, as shown in FIG. 3A, a copper wire 51 having a square cross section is prepared, and an insulating film 52 is formed on the outer surface of the copper wire 51 as shown in FIG. The insulating film 52 only needs to have a higher electric resistance than the copper wire 51, and copper oxide is often used. When copper oxide is used as the insulating film 52, the surface of the copper wire 51 is simply oxidized or stored in the air, and the copper oxide insulating film 52 is formed on the surface of the copper wire 51 having a square cross section. A copper wire 51 in a state is used. In the following description, the copper wire 51 having the insulating film 52 on the surface is defined as a “conductor wire” and represented by reference numerals 25a to 25d and 26a to 26d.

  As shown in FIG. 3C, an adhesive 53 is applied to the outer surface of the copper oxide insulating film 52 (the outer surfaces of the conductor strands 25 a to 25 d and 26 a to 26 d), or the binding layer 53 is formed. Then, as shown in FIG. 3 (d), eight conductor strands 25a to 25d and 26a to 26d each having an adhesive 53 or a binder layer 53 formed on the outer surface are bundled in two steps to form a rectangular shape. Integrate into the cross section. For example, the conductor wires 25a to 25d and 26a to 26d are aligned by passing the eight conductor wires 25a to 25d and 26a to 26d through a die having a rectangular cross-sectional opening. This is performed by bringing the surfaces of 25a to 25d and 26a to 26d into close contact with each other. In addition, each of the adhesive wires 25a to 25d and 26a to 26d is bonded by heating the integrated assembly wire 50, thereby thermosetting the adhesive 53 or the binder 53 on the surfaces of the conductor wires 25a to 25d and 26a to 26d. Then, the eight conductor strands may be integrated into a rectangular shape as shown in FIG.

  Through the processing steps up to FIG. 3C, as shown in FIG. 4, the eight conductor strands 25a to 25d and 26a to 26d are bonded to each other by the adhesive 53 or the binder 53 to form a rectangular cross section. A straight collective conducting wire 50 is formed. Then, as shown in FIG. 4, a specific portion is spot-welded so that the conductor strands 25a to 25d and 26a to 26d are not separated from each other. Spot welding 54 is performed by laser welding, resistance welding, or the like, as shown in FIG. 4, with the surfaces of the conductor wires 25a to 25d and 26a to 26d in contact with each other in one direction intersecting the longitudinal direction of each conductor wire. Welding in one direction. More specifically, in the spot welding 54, the mating surfaces of the conductor wires 25 a to 25 d arranged in a row and the conductor wires 26 a to 26 d arranged in a row are arranged in the long side direction of the rectangular cross section of the collective conducting wire 50. One-way welding is performed in which welding is performed toward the bottom (from the top to the bottom in FIG. 4). As shown in FIG. 3 (e), the spot welding 54 can weld and fix all the conductor wires 25a to 25d and 26a to 26d integrally by one welding. In this way, spot welding 54 is performed on the portion of the collective conducting wire 50 from 21a to 21k shown in FIG. After the spot welding 54 is finished, a resin layer 55 is formed on the surface of the collective conducting wire 50 by electrodeposition, as shown in FIG. The resin layer 55 reduces the friction coefficient of the surface of the collective conducting wire 50 to facilitate insertion into the slot 12 and suppresses peeling of the conductor wires 25a to 25d and 26a to 26d during processing during manufacture.

  The collective conducting wire 50 shown in FIG. 5 has a linear shape before bending. As described above, reference numerals 21a to 21k in FIG. 5 indicate positions where the spot welding 54 described with reference to FIG. 4 is performed.

  As shown in FIG. 6 which is an enlarged view of part A in FIG. 5, positions 21d and 21e in FIG. 5 are gathered at an angle of about 90 degrees by applying a bending jig 70 (round bar) between them. A bending portion 22 for bending the conducting wire 50 to form the segment coil 20 is included. As shown in FIG. 6, the position 21d of the end of the bent portion 22 and the position 21e of the end opposite to the bent portion 22 are each conductor wire as described with reference to FIG. 3 (e) and FIG. 25a to 25d and 26a to 26d are parts fixed by welding. When the bent portion 22 is bent with a small bending radius as shown in FIG. 6, conductor strands 25a on the inner peripheral side (center line 71 side of the jig 70) of the bent portion 22 as shown in FIG. 25b, 26a, and 26b are deformed so as to bulge outward by a distance d shown in FIG. 7 due to the compressive force applied by the bending process. It is deformed so that the thickness is reduced by the pulling force applied by. Thus, since each conductor strand 25a, 25b, 26a, 26b is being fixed by the spot welding 54 in the position 21c, 21d of the both ends of the bending part 22, the conductor strand 25a of the inner peripheral side in the case of a bending process is carried out. , 25b, 26a, 26b and the outer conductor wires 25c, 25d, 26c, 26d are deformed to absorb bending deformation energy or force, and the conductor wires 25a-25d, 26a-26d. The shear force acting during For this reason, even when the collective conducting wire 50 integrated with a small bending radius is bent, the conductor strands 25a to 25d and 26a to 26d are not separated from each other, and the segment coil 20 can be bent accurately. Play. As described above, in this embodiment, spot welding is performed on both end portions of the bent portion 22 when bending the collective conducting wire 50 into the segment coil 20, such as positions 21d, 21e or 21f, 21g shown in FIG. 54. Further, when the bending angle in the case of the segment coil 20 is not so large, for example, spot welding 54 is performed only on one end of the bending portion 22 as in the position 21k, and each conductor is subjected to bending. It can suppress that the strands 25a-25d and 26a-26d peel from each other.

  As shown in FIG. 5, spot welding 54 is also performed at the positions 21 a, 21 b, and 21 c of the collective conducting wire 50. As shown in FIG. 2, the positions 21a and 21b are positions at both ends of the bending portion 32 where the bending is performed after the segment coil 20 formed in the U-shape is inserted into the slot 12. Further, the position 21 c is a position corresponding to the opposite end of the bent portion across the bent portion 32 from the surface of the stator core 11. When bending the segment coil 20, the portion inserted into the slot 12 is fixed by the slot 12, so that spot welding 54 is not necessary, so that the end of the bent portion 32 on the slot 12 side is spotted. Welding is not performed. The positions 21j, 21i, and 21h illustrated in FIG. 5 are the same as the positions 21a, 21b, and 21c described above.

  As described above, the position serving as the end of the bent portion 22 when the linear assembly conductor 50 is bent into the segment coil 20, or the bent portion when bending after inserting the segment coil 20 into the slot 12. By performing spot welding 54 at a position that is the end of 32, the segment coil 20 can be accurately molded and the coil end can be accurately molded. In addition, by forming the resin layer 55 on the outer surface of the collective conducting wire 50, there is an effect that it is possible to effectively suppress the conductor wires of the collective conducting wire 50 from being peeled from each other during handling after processing.

  Next, another embodiment of the present invention will be described with reference to FIGS. The same parts as those described above with reference to FIGS. 1 to 7 are denoted by the same reference numerals, and description thereof is omitted. In the above-described embodiment, the welding of the conductor wires 25a to 25d and 26a to 26d has been described as the unidirectional spot welding 54 as shown in FIG. 4, but the welding method is not limited thereto. Instead, as shown in FIGS. 8 and 9, all-around welding for welding the entire circumference of the outer periphery of the assembly conducting wire 50 may be used. The all-around welding 56 shown in FIG. 8 is made by welding the outer periphery of a rectangular section in which eight conductor wires 25a to 25d and 26a to 26d are integrated, and the section is shown in FIG. 9 (a). As shown in FIG. 4, the outer surface portions of the eight conductor wires 25a to 25d and 26a to 26d are welded in a circumferential shape, and the effect thereof is the spot welding 54 described above with reference to FIG. It is the same. As described above with reference to FIG. 5, the all-around weld 56 is positioned at the end of the bent portion 22 when the linear collective conducting wire 50 is bent into the segment coil 20, or at the segment in the slot 12. By performing at the position that becomes the end of the bending portion 32 when bending after inserting the coil 20, the segment coil 20 can be molded with high accuracy and the coil end with high accuracy.

  Next, another embodiment of the present invention will be described with reference to FIGS. The same parts as those described above with reference to FIGS. 1 to 7 are denoted by the same reference numerals, and description thereof is omitted. In the present embodiment, in the embodiment described above with reference to FIGS. 1 to 7, as shown in FIG. 4, what is welded in one direction toward the long side of the rectangular cross section of the assembly conductor 50, One-way welding is performed in the short side direction. In the case of this embodiment, as shown in FIG. 11 at one welding position (21a to 21k) shown in FIG. 5, it is necessary to perform spot welding 57 three times, but the depth of unidirectional welding is shallow, It can be easily fixed by welding. The effect of this embodiment is the same as that of the previously described embodiment.

  In each of the embodiments described above, the end portions of the bent portions 22 and 32 are described as being welded by spot welding 54 and 57, full circumference welding 56, and the like. It is good also as welding the linear part extended from an end. In this case, it is possible to suppress the shearing force generated in the straight line portion by bending, and to suppress the peeling of the conductor wires 25a to 25d and 26a to 26d in the straight line portion.

  Further, in the embodiment described above, the case has been described in which the collective conducting wire 50 is formed into the segment coil 20, but the collective conducting wire 50 of the present invention is not only used for the segment coil 20, but also, for example, a corrugated shape. It is good also as using for shaping | molding of this coil. In this case, the conductor wires 25a to 25d and 26a to 26 at positions that become the ends of the bent portions of the corrugated coil may be fixed by spot welding 54 and 57 and all-around welding 56.

  10 Stator, 11 Stator Core, 12 Slot, 13 Teeth, 15 Inner Wall, 20 Segment Coil, 21a-21k Position, 22, 32 Bend, 25a-25d, 26a-26d Conductor Wire, 50 Assembly Wire, 51 Copper Wire , 52 Insulating film, 53 Adhesive or binding layer, 54, 57 Spot welding, 55 Resin layer, 56 Full circumference welding, 60 arrows, 70 Jig, 71 Center line, 100 Motor.

Claims (16)

A plurality of conductor wires having a rectangular cross section are arranged in parallel to each other, and are integrated conductor wires,
The conductor strands are welded together at the end of the bend to form the coil,
An assembly conductor characterized by The assembly conductor according to claim 1,
Welding is all around the outer periphery of the assembly conductor,
An assembly conductor characterized by The assembly conductor according to claim 1,
Each conductor strand is integrated so that the assembly conductor has a rectangular cross section,
Welding is a unidirectional welding that welds the surfaces of the conductor wires in contact with each other in one direction intersecting the longitudinal direction of the conductor wires;
An assembly conductor characterized by The assembly conductor according to claim 3, wherein
Welding is unidirectional welding toward the long side direction or short side direction of the rectangular cross section of the assembly conductor,
An assembly conductor characterized by The assembly conductor according to any one of claims 1 to 4,
The bend is a bend configured to form a coil end;
An assembly conductor characterized by A coil in which a plurality of conductor strands having a rectangular cross section are arranged in parallel to each other, and the integrated assembly conductor is bent,
The assembly conductor is such that the conductor strands are welded at the end of the bent portion for forming the coil,
Coil characterized by The coil according to claim 6,
Welding is all around the outer periphery of the assembly conductor,
Coil characterized by The coil according to claim 6,
Each conductor strand is integrated so that the assembly conductor has a rectangular cross section,
Welding is a unidirectional welding that welds the surfaces of the conductor wires in contact with each other in one direction intersecting the longitudinal direction of the conductor wires;
Coil characterized by The coil according to claim 8, wherein
Welding is unidirectional welding toward the long side direction or short side direction of the rectangular cross section of the assembly conductor,
Coil characterized by The coil according to any one of claims 6 to 9,
The bend is a bend configured to form a coil end;
Coil characterized by A method for manufacturing a coil, comprising:
A step of arranging a plurality of conductor strands having a rectangular cross section in parallel with each other to form an integrated assembly conductor;
Welding the conductor wires at the end of the bend to form a coil;
Bending to the shape of the coil;
The manufacturing method of the coil characterized by including. It is a manufacturing method of the coil according to claim 11, Comprising:
The welding step is to weld the outer circumference of the assembly conductor all around,
A method for manufacturing a coil, characterized in that It is a manufacturing method of the coil according to claim 11, Comprising:
In the step of making the assembly conductor, the conductor wires are integrated so as to have a rectangular cross section,
The welding step is to perform one-way welding between the surfaces where the conductor strands contact each other in one direction intersecting the longitudinal direction of each conductor strand;
A method for manufacturing a coil, characterized in that A method of manufacturing a coil according to claim 13,
The step of welding is to perform one-way welding toward the long side direction or the short side direction of the rectangular cross section of the collective conducting wire;
A method for manufacturing a coil, characterized in that A method for manufacturing a coil according to any one of claims 11 to 14,
The bend is a bend configured to form a coil end;
A method for manufacturing a coil, characterized in that It is a manufacturing method of the coil according to claim 11, Comprising:
The step of bending into the shape of the coil is a step of bending the coil into a substantially U shape,
After bending the coil, inserting the straight portion into the slot of the stator core;
Then, bending the portion protruding from the end face of the stator core;
A method of manufacturing a coil including:
The step of welding further includes welding of an end of the bending portion on the opposite side across the bending portion from the stator core side;
A method for manufacturing a coil, characterized in that

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