Coil wiring

Abstract

To provide a coil wiring that allows a coil to be arranged in an appropriate position on a stator via an insulating sheet.SOLUTION: A coil wiring 30 includes a wiring body 40 made of copper wire and an insulating sheet 20 wrapped around the wiring body 40. The insulating sheet 20 has an insulating sheet core material 23, an outer cover layer 21 that forms the outer surface of the coil wiring 30, and an inner cover layer 22 that contacts the wiring body 40. Between the outer cover layer 21 and the wiring body 40, a first adhesive layer 26A is provided including a first adhesive 24A and a first foam bead 25A. Between the inner cover layer 22 and the wiring body 40, a second adhesive layer 26B is provided including a second adhesive 24B and a second foam bead 25B. The foaming start temperature of the first foam bead 25A is higher than the foaming start temperature of the second foam bead 25B.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to coil wiring used for coils arranged on teeth formed on a stator of a rotating electric machine. [Background technology]

[0002] Conventionally, a slot is formed in the stator of a rotating electric machine, and a coil is arranged in the slot. In order to fix the coil in the slot, a sheet material or the like is sometimes used. For example, Patent Document 1 discloses a rotating electric machine in which an insulating sheet is wrapped around the entire circumference of a coil. In this technology, the inner circumference side of the coil covered with the insulating sheet is inserted along the outer surface of the teeth. The insulating sheet expands when heated, and the coil is bonded to both the teeth and the coil part in the slot via the insulating sheet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-162565 A Summary of the Invention [Problem to be solved by the invention]

[0004] The sheet material described in Patent Document 1 places an insulating sheet between the stator and the coil, and by heating this, the gap between the coil and the inner wall surface of the slot can be eliminated or reduced. However, there is a risk that the position of the insulating sheet may shift when the insulating sheet expands.

[0005] The present invention has been made in consideration of such problems, and has an object to provide coil wiring that enables a coil to be arranged in an appropriate position on a stator via an insulating sheet. [Means for solving the problem]

[0006] In consideration of the above problems, the coil wiring of the present invention is a coil wiring used for a coil arranged on a tooth formed in a stator core of a rotating electric machine, the coil wiring comprising a wiring body made of copper wire and an insulating sheet wrapped around the wiring body, the insulating sheet having an insulating sheet core material, an outer cover layer forming an outer surface of the coil wiring, and an inner cover layer in contact with the wiring body, a first adhesive layer containing a first adhesive and first foaming beads is provided between the outer cover layer and the wiring body, a second adhesive layer containing a second adhesive and second foaming beads is provided between the inner cover layer and the wiring body, and the foaming start temperature of the first foaming beads is higher than the foaming start temperature of the second foaming beads. Effect of the Invention

[0007] According to the present invention, the coil can be disposed at an appropriate position on the stator via an insulating sheet. [Brief description of the drawings]

[0008] [Figure 1] 1A is a cross-sectional view of an insulating sheet, FIG. 1B is an oblique view of the coil wiring, FIG. 1C is a cross-sectional view of the coil wiring, FIG. 1D is an enlarged view of part A when the coil wiring shown in FIG. 1C is heated, and FIG. 1E is an oblique view of the coil wiring after it has been deformed. [Diagram 2] FIG. 1(a) is an oblique view for explaining the operation of inserting the coil wiring shown in FIG. 1(e) into a stator core, FIG. 1(b) is an oblique view for explaining the state in which the coil wiring is arranged in the stator core, and FIG. 1(c) is an enlarged view of part B when the coil wiring shown in FIG. 1(b) is heated. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] An embodiment of the coil wiring according to the present invention will be described in detail below with reference to the drawings. The rotating electric machine 10 in which the coil wiring 30 according to this embodiment is arranged is a three-phase AC motor, and FIG. 2(b) shows a main part of a stator showing only the portion where the U phase and the V phase of the coil are in contact at the coil end. Therefore, in other portions, there are portions where the U phase and the W phase are in contact at the coil end, and portions where the V phase and the W phase are in contact at the coil end. It is needless to say that the rotating electric machine is not limited to a three-phase AC motor.

[0010] Specifically, as shown in Fig. 2(b), slots 14 are formed in the stator core 11 of the rotating electric machine 10, and coils 30A formed by bending coil wiring 30 are arranged in the slots 14. The slots 14 are spaces sandwiched between the teeth 12, 12 extending toward the center of the stator 2, and the coils 30A are arranged in these spaces. Although not shown, the coils 30A are formed by stacking a plurality of coil wirings 30, 30... each having a rectangular cross-sectional shape and adhesively fixing them together.

[0011] As shown in FIG. 1(b), the coil wiring 30 includes a wiring body 40 made of a copper wire, and an insulating sheet 20 spirally wound around the wiring body 40. The insulating sheet 20 is a strip-shaped sheet. The insulating sheet 20 is spirally wound around the wiring body 40 so that the periphery of the insulating sheet 20 is wrapped around the wiring body 40, but for example, the insulating sheet 20 may be wrapped around the center of the insulating sheet 20 in a spiral manner. In this way, two layers of the insulating sheet 20 can be formed in the coil wiring 30.

[0012] As shown in Figures 1(a) and (c), the insulating sheet 20 has an insulating sheet core material 23, an outer cover layer 21 that forms the outer surface of the coil wiring 30, and an inner cover layer 22 that contacts the wiring main body 40.

[0013] The insulating sheet core material 23 is not particularly limited as long as it has insulating properties and flexibility, but may be a resin film such as polyethylene naphthalate (PEN), or may be a woven or nonwoven fabric made of resin fibers. A first adhesive layer 26A including a first adhesive 24A and first foamed beads 25A is provided between the outer cover layer 21 and the wiring body 40. A second adhesive layer 26B including a second adhesive 24B and second foamed beads 25B is provided between the inner cover layer 22 and the wiring body 40. The foaming start temperature (expansion start temperature) of the first foamed beads 25A is higher than the foaming start temperature (expansion start temperature) of the second foamed beads 25B.

[0014] The materials for the outer cover layer 21 and the inner cover layer 22 are not particularly limited as long as they are capable of allowing the first adhesive 24A or the second adhesive 24B to seep out, and it is preferable that the outer cover layer 21 and the inner cover layer 22 are a porous resin sheet material, or a woven or nonwoven fabric made of resin fibers.

[0015] The first adhesive 24A and the second adhesive 24B may be, for example, an epoxy adhesive. Although not shown, the first foaming beads 25A are foaming beads in which a first expansion agent is encapsulated in a first shell made of a thermoplastic resin, and the second foaming beads 25B are foaming beads in which a second expansion agent is encapsulated in a second shell made of a thermoplastic resin. The first shell and the second shell may be, for example, a polypropylene resin or an acrylic resin.

[0016] The first and second expanding agents are made of hydrocarbons, and expand and gasify when heated, and the first expanding agent has a higher boiling point and is less likely to gasify than the second expanding agent, so that the expansion start temperature of the first foaming beads 25A can be made higher than the expansion start temperature of the second foaming beads 25B.

[0017] Such coil wiring 30 is used as follows: Specifically, as shown in Fig. 1(c), the coil wiring 30 is heated by a heating device 50 at a heating temperature lower than the foaming start temperature of the first foaming beads 25A and equal to or higher than the foaming start temperature of the second foaming beads 25B.

[0018] 1(d), the second foamed beads 25B of the second adhesive layer 26B expand, causing the second adhesive layer 26B to foam (expand). This expansion causes the second adhesive 24B to seep out from the second adhesive layer 26B into the inner cover layer 22, and the second adhesive 24B can fill the gap between the inner cover layer 22 and the wiring main body 40. As a result, the insulating sheet 20 can be bonded to the wiring main body 40.

[0019] Thereafter, even if the coil wiring 30 is deformed so as to be wound around the teeth 12 of the stator core as shown in FIG. 1(c), the insulating sheet 20 is hardly displaced relative to the wiring main body 40 because the wiring main body 40 and the insulating sheet 20 are adhered to each other.

[0020] After the coil wiring 30 is deformed in this manner, as shown in Fig. 2(a), it is placed in the slot 14 so as to be wound around the teeth 12 of the stator core 11. Next, as shown in Fig. 2(b), the coil wiring 30 is heated by a heating device 50 at a heating temperature equal to or higher than the foaming start temperature of the first foaming beads 25A.

[0021] 2(c), the first foaming beads 25A of the first adhesive layer 26A expand, causing the first adhesive layer 26A to foam (expand). This expansion causes the first adhesive 24A to seep out from the first adhesive layer 26A into the outer cover layer 21, and the first adhesive layer 26A can be filled between the outer cover layer 21 and the wall surface 15 of the tooth 12. As a result, the coil wiring 30 can be adhered to an appropriate position of the stator core 11.

[0022] Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment, and various design modifications can be made without departing from the spirit of the present invention described in the claims. [Explanation of symbols]

[0023] 10: rotating electric machine, 11: stator core, 14: slot, 20: insulating sheet, 21: outer cover layer, 22: inner cover layer, 23: sheet core material, 24A: first adhesive, 24B: second adhesive, 25A: first foam beads, 25B: second foam beads

Claims

[Claim 1] A coil wiring used for a coil arranged on a tooth formed on a stator core of a rotating electric machine, The coil wiring includes a wiring body made of a copper wire, and an insulating sheet wrapped around the wiring body, the insulating sheet has an insulating sheet core material, an outer cover layer forming an outer surface of the coil wiring, and an inner cover layer in contact with the wiring main body, a first adhesive layer including a first adhesive and first foam beads is provided between the outer cover layer and the wiring body; a second adhesive layer including a second adhesive and second foam beads is provided between the inner cover layer and the wiring body; A coil wiring, characterized in that the foaming start temperature of the first foaming beads is higher than the foaming start temperature of the second foaming beads.

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