JP2023045670A - Conductive member manufacturing method - Google Patents

Abstract

To secure an insulation property of a conductive member, while suppressing an insulative film of the conductive member as a whole from getting thicker.SOLUTION: A conductive member manufacturing method has a step of coating a conductive body with an insulative film (an insulative coated film), where the step has a first step of forming a bent part on a conductive body using a forming die and a second step of flowing an insulative material to a gap between the forming die and the conductive body to form an insulative film on a surface of the conductive body. This can suppress the insulative film at an outer periphery side of the bent part of the conductive body from getting thinner, in comparison with a case where the conductive body is coated with the insulative film and then the bent part is formed.SELECTED DRAWING: Figure 4

Description

The present invention relates to a method for manufacturing a conductive member.

Conventionally, it has been proposed that a plurality of U-shaped segment coils for constituting a stator coil of a rotating electrical machine are each formed of a rectangular wire in which the outer circumference of a conductor is coated with an insulating film (insulating film). (See Patent Document 1, for example).

WO2019/003559

When forming a U-shaped segment conductor by bending a rectangular wire whose outer periphery is coated with an insulating film (insulating film), the insulating film on the outer peripheral side of the bent portion may become thin. In order to ensure the thickness of the insulating film in this portion, the insulating film needs to be thickened as a whole, leading to a reduction in the space factor.

A main object of the method for manufacturing a conductive member of the present invention is to ensure the insulating properties of the conductive member while suppressing an increase in the thickness of the insulating film over the entire conductive member.

The method for manufacturing a conductive member of the present invention employs the following means to achieve the above-described main object.

The method for manufacturing a conductive member of the present invention comprises:
A method for manufacturing a conductive member, comprising a step of coating a conductor with an insulating film,
Said step is
a first step of forming a bend in the conductor using a mold;
and a second step of forming the insulating film on the surface of the conductor by flowing an insulating material into the gap between the mold and the conductor.
This is the gist of it.

In the method for manufacturing a conductive member of the present invention, the step of coating the conductor with an insulating film (insulating film) includes a first step of forming a bent portion in the conductor using a mold; and a second step of forming an insulating film on the surface of the conductor by pouring an insulating material into the gap between the mold and the conductor. By doing so, it is possible to suppress thinning of the insulating film on the outer peripheral side of the bent portion of the conductor, as compared with the case where the bent portion is formed after covering the conductor with the insulating film. As a result, the insulating properties of the conductive member can be ensured while preventing the insulating film of the entire conductive member from becoming thicker (lowering the space factor).

1 is a configuration diagram showing the outline of the configuration of a stator 10 using a conductive member manufactured by a manufacturing method of a conductive member as one embodiment of the present invention; FIG. 2 is a configuration diagram showing an outline of the configuration of a segment coil 13; FIG. 4A to 4C are process diagrams showing each step of the method for manufacturing the segment coil 13. FIG. It is explanatory drawing of process S100, S110.

Next, a mode for carrying out the present invention will be described using examples.

FIG. 1 is a configuration diagram showing the outline of the configuration of a stator 10 using a conductive member manufactured by a method for manufacturing a conductive member as one embodiment of the present invention. The stator 10 constitutes a three-phase AC motor (a synchronous motor or an induction motor) used in an electric vehicle or a hybrid vehicle together with a rotor (not shown). This stator 10 comprises a stator core 11 and a plurality of stator coils 12 . A segment coil 13, which is used in the stator coil 12 and will be described later, corresponds to the conductive member of the embodiment.

The stator core 11 is formed, for example, by laminating a plurality of electromagnetic steel plates formed into an annular shape by pressing and connecting them in the lamination direction by caulking or the like. The stator core 11 may be integrally formed by, for example, press-molding and sintering ferromagnetic powder. The stator core 11 extends radially from the annular outer peripheral portion (yoke portion) toward the axial center (the center of the stator core 11) and is adjacent to the center hole in which the rotor is arranged at a constant interval in the circumferential direction. It has a plurality of tooth portions (not shown) that match each other and a plurality of slots (not shown) formed between adjacent tooth portions. The plurality of slots each extend in the radial direction of the stator core 11, are arranged in the circumferential direction at regular intervals, and open at the center hole.

The plurality of stator coils 12 has coils of each phase (U phase, V phase, W phase), and each stator coil 12 electrically connects a plurality of segment coils (conductive members) 13 inserted into the stator core 11. It is formed by Each segment coil 13 is, as shown in FIG. 2, a substantially U-shaped rectangular wire in which the surface of a conductor 17 is covered with an insulating film (insulating coating) 18 . As a material of the conductor 17, for example, copper or the like is used. As the material of the insulating film 18, for example, a low dielectric constant fluororesin, polyimide, polyetherimide, polyamide, or the like is used. Each segment coil 13 has a base portion 14 and a pair (two) of leg portions 16 extending from both ends of the base portion 14 to the same side via bent portions 15 . At the tip of each leg 16, the insulating film 18 is removed and the conductor 17 is exposed.

The two legs 16 of each segment coil 13 are inserted through different slots of the stator core 11, respectively. The tip of leg 16 of each segment coil 13 protruding from one end face (upper end face in FIG. 1) of stator core 11 is electrically welded to the tip of leg 16 of another corresponding segment coil 13 . is spliced to Thereby, a plurality of stator coils 12 are wound around the stator core 11 . A coil end portion 12a is formed on one end side (upper end side in FIG. 1) of the stator core 11 in the axial direction, and an annular coil end portion 12b is formed on the other end side (lower end side in FIG. 1). The coil end portions 12a and 12b are each formed by a plurality of stator coils 12, that is, a plurality of segment coils 13, and protrude outward from the end face of the stator core 11 in the axial direction.

Next, a method for manufacturing the U-shaped segment coil 13 will be described. FIG. 3 is a process chart showing each process of the method for manufacturing the segment coil 13. As shown in FIG. In the method for manufacturing the segment coil 13, the linear conductor 17 is formed into a U shape (step S100), and the conductor 17 is covered with the insulating film 18 to form the intermediate member 13a (step S110). Hereinafter, each portion of the U-shaped conductor 17 and an intermediate member 13a, which will be described later, will be referred to as a base portion 14, a bent portion 15, and a leg portion 16, like the segment coil 13. FIG.

FIG. 4 is an explanatory diagram of steps S100 and S110. As shown, the mold 20 has a recess 21 whose length (depth) in the direction of penetrating the paper surface is slightly longer than that of the linear conductor 17 and whose lower side in FIG. ), and a plurality of sprayers 22 for spraying the liquid insulating material onto the substrate. The mold 24 has a convex portion 25 that can enter the concave portion 21 and a plurality of sprayers 26 for spraying the insulating material to the outside. As the insulating material, as described above, for example, a low dielectric constant fluororesin, polyimide, polyetherimide, polyamide, or the like is used. The number and positions of sprayers 22 and 26 are determined based on the size and shape of conductor 17 . In FIG. 4, the gap between the molds 20 and 24 and the conductor 17 is exaggerated. In step S100, a linear conductor 17 is bent using molds 20 and 24 to form a U-shaped conductor 17 having a base 14, a pair of bent portions 15, and a pair of legs 16. , a conductor 17 is formed. In step S110, an insulating film 18 is formed on the surface of the conductor 17 by spraying an insulating material from a plurality of sprayers 22 and 26 into the gap between the molds 20 and 24 and the U-shaped conductor 17. An intermediate member 13a is formed.

Then, the molding dies 20 and 24 are separated from the intermediate member 13a (step S120), and the insulating film 18 is removed from the tip end portions of the pair of (two) leg portions 16 of the intermediate member 13a (step S130) to form a segment coil. Complete 13.

Thus, by manufacturing the U-shaped segment coil 13 including the step S110 of covering the entire U-shaped conductor 17 with the insulating film 18, the entire linear conductor 17 is coated with the insulating film 18. It is possible to suppress thinning of the insulating film 18 on the outer peripheral side of the bent portion 15 (see FIGS. 2 and 4) of the segment coil 13, as compared with the case of forming the U shape after coating. As a result, the insulation of the segment coil 13 can be ensured while suppressing the thickness of the insulating film 18 of the entire segment coil 13 (lowering of the space factor).

In the manufacturing method of the segment coil 13 of the embodiment described above, the U-shaped segment coil 13 is manufactured including the step of covering the entire U-shaped conductor 17 with the insulating film 18 . In this step, the linear conductor 17 is formed with a bent portion 15 using molding dies 20 and 24 to be molded into a U-shape, and the gap between the molding dies 20 and 24 and the U-shaped conductor 17 is bent. An insulating material is sprayed from a plurality of sprayers 22 and 26 to form an insulating film 18 on the surface of the conductor 17 . As a result, thinning of the insulating film 18 on the outer peripheral side of the bent portion 15 of the segment coil 13 can be suppressed. As a result, the insulation of the segment coil 13 can be ensured while suppressing the thickness of the insulating film 18 of the entire segment coil 13 (lowering of the space factor).

In the manufacturing method of the segment coil 13 of the embodiment, in step S110, the surface of the conductor 17 is insulated by spraying the insulating material from the plurality of sprayers 22 and 26 into the gap between the molds 20 and 24 and the conductor 17. It was assumed that the film 18 was deposited. However, any method may be used as long as the insulating material is poured into the gap between the molds 20 and 24 and the conductor 17 to form the insulating film 18 on the surface of the conductor 17. sol-gel method, electrodeposition coating method, physical vapor deposition method (vacuum vapor deposition method, ion plating method, sputtering method), chemical vapor deposition method, and the like. As the insulating material in this case, fluorine-based resin, polyimide, polyetherimide, polyamide, or the like can be used as in the embodiment. Alternatively, the gap between the molds 20 and 24 and the conductor 17 may be filled with ozone to form an oxide film (alumina or the like) on the surface of the conductor 17 .

In the embodiment, the method for manufacturing the U-shaped segment coil 13 has been described as the method for manufacturing the conductive member. However, any conductive member may be used as long as it has a bent portion and the surface of the conductor is covered with an insulating film. , various ones can be mentioned. A conductor and an insulating film can be appropriately selected according to the conductive member. Examples of the conductor include gold, silver, aluminum, conductive resin, etc., in addition to the copper described above. Examples of the insulating film include acrylic, wood, paper, concrete, etc., in addition to the fluorine-based resin, polyimide, polyetherimide, and polyamide described above.

The correspondence relationship between the main elements of the embodiments and the main elements of the invention described in the column of Means for Solving the Problems will be described. In the embodiment, the conductor 17 corresponds to the "conductor", the insulating film 18 corresponds to the "insulating film", and the segment coil 13 corresponds to the "conductive member".

Note that the correspondence relationship between the main elements of the examples and the main elements of the invention described in the column of Means for Solving the Problems is the Since it is an example for specifically explaining the mode for solving the problem, it does not limit the elements of the invention described in the column of the means for solving the problem. That is, the interpretation of the invention described in the column of Means to Solve the Problem should be made based on the description in that column, and the Examples are based on the description of the invention described in the column of Means to Solve the Problem. This is only a specific example.

Although the embodiments for carrying out the present invention have been described above, the present invention is not limited to such embodiments at all, and can be modified in various forms without departing from the scope of the present invention. Of course, it can be implemented.

INDUSTRIAL APPLICABILITY The present invention can be used in the manufacturing industry of conductive members.

10 stator, 11 stator core, 12 stator coil, 12a, 12b coil end portion, 13 segment coil, 13a intermediate member, 14 base portion, 15 bent portion, 16 leg portion, 17 conductor, 18 insulating film, 20, 24 mold, 21 concave portion, 22, 26 sprayer, 25 convex portion, 30 reservoir, 32 liquid.

Claims (1)

A method for manufacturing a conductive member, comprising a step of coating a conductor with an insulating film,
Said step is
a first step of forming a bend in the conductor using a mold;
and a second step of forming the insulating film on the surface of the conductor by flowing an insulating material into the gap between the mold and the conductor.
A method for manufacturing a conductive member.

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