JP7432290B2 - Manufacturing method of segment coil - Google Patents

Description

The present invention relates to a method for manufacturing a segment coil.

In recent years, electric vehicles such as hybrid cars and electric cars are rapidly becoming popular for the purpose of reducing greenhouse gas emissions. Among the various motors installed in these electric vehicles, it is particularly desired that the drive motor be small and have high output. Therefore, as a material for forming the stator coil of this type of motor, rectangular wire (coated rectangular wire consisting of a conductor wire with a substantially rectangular cross section and an insulating film covering the periphery), which can increase the space factor of the stator coil, is important. There is a tendency to In this case, the stator coil has a U-shape consisting of a pair of parallel straight parts and a mountain part connecting these parts, and a plurality of rectangular wires (segment coils) with conducting wires exposed at the free ends of the straight parts are attached to the annular stator core. It is manufactured by following the steps of attaching the segment coils to the same phase, electrically joining the free ends (conducting wires) of segment coils of the same phase to each other by means such as welding, and then applying insulation treatment to this joint.

The above segment coil is produced, for example, as follows.
The long rectangular wire is unwound from the drum (bobbin) on which the rectangular wire is wound and fed in the longitudinal direction (intermittently fed). First, the insulating film is removed using a processing machine for film removal. Then, the portion from which the insulating film has been removed is cut using a cutting machine disposed downstream of the processing machine for removing the film. As a result, a rectangular wire (coil material) of a predetermined length with conducting wires exposed at both ends in the longitudinal direction is obtained. Thereafter, this coil material is bent and formed to obtain a U-shaped segment coil (see, for example, Patent Document 1).

JP2020-54156A

By the way, to form one stator coil, multiple types of segment coils with different overall length dimensions are required, but the multiple types of segment coils required to form one stator coil affect the quality of the motor. From the viewpoint of guarantee, it is desirable to form the wires using rectangular wires unwound from the same bobbin. Therefore, when producing a coil material in the above manner, it is necessary to move the processing machine (change the arrangement position of the processing machine) according to the overall length dimension of the segment coil to be produced.

However, if the arrangement position of the processing machine is changed depending on the overall length of the segment coil, an increase in cycle time is inevitable. In addition, in order to smoothly change the location of the processing machine, it is necessary to use a movable processing machine that is easy to move. Since it is inferior in terms of rigidity, it has disadvantages such as difficulty in securing the required machining accuracy and short durability life. Furthermore, when the arrangement position of the processing machine is changed, it is also necessary to change the feed amount of the rectangular wire, resulting in a problem that processing equipment becomes complicated and expensive to control.

In view of the above circumstances, the main object of the present invention is to enable efficient and accurate manufacture of multiple types of segment coils having different overall length dimensions.

The present invention, which was created to achieve the above object, manufactures a segment coil that has a U-shape consisting of a pair of parallel straight parts and a mountain part connecting these parts, and has a conducting wire exposed at the free end of the straight part. This is a method for sequentially performing predetermined processing on a long rectangular wire fed in the longitudinal direction using a plurality of processing machines arranged at intervals along the longitudinal direction (feeding direction). This method was introduced into the material manufacturing process: a material manufacturing process in which coil materials are cut into a predetermined length and conductive wires are exposed at both ends in the longitudinal direction, and a bending process to obtain segment coils by bending the coil material. A protrusion forming step in which a protrusion is formed that protrudes in a direction perpendicular to the longitudinal direction of the rectangular wire before being molded, and the protrusion amount of the protrusion formed in the protrusion forming step is determined by determining the amount of protrusion of the segment coil to be produced. It is characterized by changing according to the overall length dimension. Note that the "flat wire" as used in the present invention is a coated flat wire consisting of a conducting wire having a rectangular cross section and an insulating film covering the periphery thereof.

In the present invention, a protrusion that protrudes in a direction perpendicular to the longitudinal direction of a long rectangular wire (for example, a rectangular wire immediately after being unwound from a bobbin) before being introduced into the material manufacturing process is provided. The protruding amount of the protruding portion is changed depending on the overall length L of the segment coil to be produced. In this case, it is possible to change the overall length of the coil material, which is the material for forming the segment coil, according to the amount of protrusion of the protrusion, so the arrangement position of each processing machine (the arrangement interval of processing machines) can be changed. Coil materials having a total length corresponding to the total length of the segment coil to be manufactured can be manufactured one after another without changing the feeding amount of the flat wire. Therefore, it is possible to efficiently manufacture (mass produce) a plurality of types of segment coils having different overall lengths. Note that the protrusion formed on the coil material can be eliminated by performing a bending process of bending the coil material. Therefore, the shape accuracy of the segment coil does not deteriorate because the protrusion is formed on the coil material.

When carrying out the present invention, it will be necessary to additionally provide a processing machine for forming the protrusion and to change (adjust) the stroke amount of this processing machine each time, but the cost and effort required for this will be reduced. , compared to changing the arrangement position of the processing machine or the feed amount of the flat wire, etc., it is much less necessary. In addition, if the present invention is adopted, as mentioned above, there will be no need to change the arrangement positions of the various processing machines used to produce the coil material, so the processing precision and durability of the processing machines will be higher than that of movable machines. A fixed-point installation type with excellent performance can be adopted. Thereby, it is possible to stably and accurately mass-produce coil materials having different overall length dimensions, and by extension, segment coils.

Preferably, the protrusion is formed in the longitudinal center of the coil material. In this way, the protrusion can be used for positioning when bending the coil material into a symmetrical U-shape, so that the shape accuracy of the segment coil can be easily improved.

As described above, according to the present invention, it is possible to efficiently and accurately manufacture a plurality of types of segment coils having different overall length dimensions.

(a) is a plan view of the segment coil, and (b) is an enlarged sectional view taken along the ZZ line in FIG. (a). It is a flow chart showing a manufacturing procedure of a segment coil. FIG. 2 is a side view conceptually showing the overall structure of processing equipment for obtaining a coil material. FIG. 4 is a diagram showing three types of coil materials obtained using the processing equipment shown in FIG. 3 and a state in which these coil materials are developed. It is a figure which shows an example of a bending process.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1(a) is a plan view of a segment coil 1 manufactured by applying the present invention, and FIG. 1(b) is an enlarged sectional view taken along the line ZZ in FIG. 1(a). This segment coil 1 includes a conductor wire 3 having a rectangular cross-section and a pair of parallel wide surfaces (flatwise surfaces) and a pair of mutually parallel narrow surfaces (edgewise surfaces), and an insulator covering the periphery of the conductor wire 3. A rectangular wire 2 (specifically, a rectangular wire 2 of a predetermined length with conductive wires 3 exposed at both ends in the longitudinal direction) consisting of a film 4 is connected to a pair of mutually parallel straight portions 1a, and both straight portions 1a are connected. It is obtained by bending it into a bilaterally symmetrical U-shape consisting of the peaks 1b.

The above-mentioned segment coil 1 is used, for example, as a material for forming a stator coil of a drive motor of an electric vehicle such as a hybrid vehicle or an electric vehicle, but the stator coil is usually made of a plurality of stator coils having different overall lengths L. It is formed using a seed segment coil 1. The manufacturing method according to the present invention is characterized in that a plurality of types of segment coils 1 having different overall lengths L can be manufactured efficiently and accurately. Hereinafter, a method of manufacturing a segment coil 1 according to the present invention and a processing equipment 10 used when implementing this manufacturing method will be described.

As shown in FIG. 2, the segment coil 1 is obtained through a protrusion forming step S1, a material manufacturing step S2, and a bending step S3 in this order. Among these steps S1 to S3, the protrusion forming step S1 and the material manufacturing step S2 are performed successively using the processing equipment 10 conceptually shown in FIG. 3, and the bending step S3 is performed separately from the processing equipment 10. The process is carried out using a bending machine equipped with a

Note that the protrusion forming step S1 is a step of forming a protrusion 5 that protrudes in a direction perpendicular to the longitudinal direction on the long rectangular wire 2 fed in the longitudinal direction, and the material production step S2 is a step of forming a protrusion 5 to a long rectangular wire 2 fed in the longitudinal direction. A process of obtaining a coil material 6 (see the diagram on the left side of the paper in FIG. 4) in which the conductive wire 3 is exposed at both ends in the longitudinal direction and the protrusion 5 is formed in the central part in the longitudinal direction, and a bending process. S3 is a step of bending the coil material 6 to obtain the segment coil 1 shown in FIG. 1(a).

FIG. 3 is a side view conceptually showing the overall structure of the processing equipment 10 used to successively carry out the protrusion forming step S1 and the material manufacturing step S2, as described above. In the processing equipment 10 shown in the figure, a long rectangular wire 2 is unwound from a bobbin 11 and is intermittently fed in the longitudinal direction (horizontal direction) from the left side to the right side in the figure by a conveying means not shown. By sequentially performing predetermined processing in each of the plurality of processing machines provided in the first area A1 and the second area A2, various coil materials 6 as shown in FIG. Coil materials 6 having different dimensions are produced one after another.

Note that, as the conveying means, for example, one that moves along the longitudinal direction of the flat wire 2 while chucking the flat wire 2 is used. Since it is necessary to apply a feeding force to the flat wire 2 before cutting, the conveying means is, for example, one of the plurality of processing machines 12 to 15 provided in the second area A2, which cuts the flat wire 2. 4 is provided upstream of the processing machine 15. The coil material 6 produced by cutting the rectangular wire 2 is taken out from the processing equipment 10 manually or by a device provided separately from the above-mentioned transport means.

The first area A1 is provided with a processing machine for carrying out the protrusion forming step S1, specifically, a forming machine for forming the protrusion 5 on the long rectangular wire 2. This forming processing machine uses a pressure member 16 disposed below the rectangular wire 2 that is sent in the horizontal direction, and a pressure member 16 that is moved at an arbitrary timing (here, a protrusion is formed at the longitudinal center of each coil material 6). The stroke amount of the pressure member 16 (the amount of upward movement with respect to the bottom dead center indicated by the two-dot chain line in FIG. 3) is It can be changed arbitrarily. The pressure member 16 has a pressure surface that presses the rectangular wire 2 upward as it moves upward, and the pressure surface in this embodiment has an inverted V shape.

Note that if the region of the flat wire 2 on the downstream side of the part where the protrusion 5 is to be formed is lifted due to the upward movement of the pressure member 16, the protrusion 5 of a predetermined shape may not be formed on the rectangular wire 2. There is a possibility that the desired coil material 6 cannot be obtained. Therefore, although not shown in the drawings, for example, on the downstream side of the pressure member 16 (an area between the pressure member 16 and the first processing machine 12 described later), the pressure surface of the pressure member 16 has a rectangular line. 2 and until the pressure member 16 moves to the upper limit, a regulating means is provided for regulating the region of the flat wire 2 on the downstream side of the part where the protruding part 5 is to be formed from being lifted up. is preferred. As a result, when the pressurizing surface of the pressurizing member 16 is pressed against the flat wire 2 as the pressurizing member 16 moves upward, the inverted V-shaped (pointed) protrusion 5 that protrudes upward from the rectangular wire 2 can be pressed with precision. Can be molded well.

The stroke amount of the pressure member 16 is changed according to the overall length L of the segment coil 1 (coil material 6) to be manufactured. Specifically, the stroke amount of the pressure member 16 is increased as the overall length L of the segment coil 1 to be manufactured increases. Therefore, the amount of protrusion of the protrusion 5 formed on the rectangular wire 2 increases as the overall length L of the segment coil 1 to be manufactured increases.

In the processing equipment 10 of the illustrated example, as shown in the right side view of FIG. 4, there are three types of coil materials 6 having different total length dimensions (total length dimensions when unfolded), specifically, a coil material 6A having a total length dimension L1. Then, a coil material 6A having a total length L2 (L2>L1) and a coil material 6A having a total length L3 (L3>L2) are obtained. In this case, [stroke amount of the pressure member 16 when producing the coil material 6A]<[stroke amount of the pressure member 16 when producing the coil material 6B]<[pressure when producing the coil material 6C] The stroke amount of the pressurizing member 16 is changed so that the following relational expression is established.

In the second area A2, a plurality of processing machines used to perform the material manufacturing step S2 are arranged at intervals along the longitudinal direction. In the illustrated example, a total of four processing machines, the first to fourth processing machines 12 to 15, are arranged at the same pitch P1. The first processing machine 12 to the fourth processing machine 15 each perform the following processing on the rectangular wire 2, for example.
- First processing machine 12: Make cuts to facilitate the removal of the insulating film 4 at both ends of the rectangular wire 2 in the longitudinal direction of the region where the insulating film 4 is scheduled to be removed (hereinafter simply referred to as the "scheduled removal region"). Form.
- Second processing machine 13: performs processing to remove a part of the insulating film 4 existing in the region to be removed of the rectangular wire 2 (for example, peeling processing using a blade type).
- Third processing machine 14: performs processing to remove the remaining portion of the insulating film 4 existing in the region to be removed of the rectangular wire 2 (for example, peeling processing using a blade type).
- Fourth processing machine 15: Cuts the longitudinal center of the flat wire 2 from which the insulating film 4 has been removed.

Hereinafter, embodiments of the protrusion forming step S1 and material manufacturing step S2 will be briefly described based on FIG. 3, and an embodiment of the bending step S3 will be briefly described based on FIG.

First, a protrusion 5 (5A) is formed on the long flat wire 2 unwound from the bobbin 11, which is wound with the flat wire 2, by a forming machine (pressing member 16) provided in the first area A1. molded. At the same time, a first processing is performed in a second area A2 at both ends in the longitudinal direction of the area to be removed of the insulating film 4 located downstream of the molded part of the protrusion 5 (5A) of the flat wire 2. A cut is formed by the machine 12. When the processing by the above-mentioned forming machine and the first processing machine 12 is completed, the rectangular wire 2 is moved to the downstream side so that the area to be removed with cuts formed at both ends in the longitudinal direction is introduced into the second processing machine 13. Sent.

When the part of the rectangular wire 2 in which the cut is formed is introduced into the second processing machine 13, the second processing machine 13 performs processing to remove a part of the insulating film 4 on the part, and also, A cut is formed by the first processing machine 12 in a region of the insulating film 4 to be removed that is located upstream of the portion of the rectangular wire 2 where the protruding portion 5A is formed. At the same time, a protrusion 5 (5B) having a larger protrusion amount than the protrusion 5A is formed on the rectangular wire 2 by a molding machine (pressure member 16). Thereafter, each time the processing by each processing machine is completed, the rectangular wire 2 is intermittently fed to the downstream side, and predetermined processing is simultaneously performed at a plurality of locations in the longitudinal direction of the rectangular wire 2. Then, when the flat wire 2 is cut by the fourth processing machine 15, the conducting wire 3 is exposed at both ends in the longitudinal direction, and a protrusion 5 (5A) is formed at the center in the longitudinal direction. Coil material 6 (6A) is obtained. In addition, in the processing equipment 10 shown in FIG. 3, a coil material 6B (or 6C) having a protrusion 5B (or 5C) having a different protrusion amount from the protrusion 5A can also be obtained. The longitudinal dimensions of the coil materials 6A, 6B, and 6C are the same (see the diagram on the left side of the paper in FIG. 4).

The coil material 6 obtained as described above is introduced into a bending step S3. In the bending step S3, the coil material 6 is bent using a bending device (forming die) as shown in FIG. By performing this, a U-shaped segment coil 1 shown in FIG. 1(a) is obtained.

As explained above, in the present invention, the long rectangular wire 2 (the rectangular wire 2 immediately after being unwound from the bobbin 11) before the material manufacturing step S2 is performed, in the longitudinal direction. A material manufacturing step S1 of forming the protrusion 5 protruding in the orthogonal direction is performed, and in the step S1, the amount of protrusion of the protrusion 5 is changed according to the overall length L of the segment coil 1 to be produced. In this case, it is possible to change the overall length of the coil material 6, which is the material for forming the segment coil 1, according to the amount of protrusion of the protrusion 5 (see the diagram on the right side of the paper in FIG. 4). Without changing the arrangement positions of the processing machines 12 to 15 provided for carrying out the manufacturing process S2 or changing the feed amount of the flat wire 2 (in short, the arrangement intervals of the processing machines 12 to 15 can be set at a constant pitch). P1), it is possible to successively manufacture coil materials 6 having a total length dimension corresponding to the total length dimension of the segment coil 1 to be manufactured. Therefore, it is possible to efficiently manufacture a plurality of types of segment coils 1 having different overall length dimensions.

Note that the protrusion 5 formed on the coil material 6 can be eliminated by performing the bending step S3 of bending the coil material 6 into a U-shape. Therefore, since the protruding portion 5 is formed on the coil material 6, the shape accuracy of the segment coil 1 does not deteriorate. Rather, as shown in the figure on the left side of the paper in FIG. 4, if the protruding part 5 is formed in the longitudinal center of the coil material 6, the protruding part 5 can be positioned easily when the coil material 6 is bent into a U-shape. This is advantageous in improving the shape accuracy of the segment coil 1.

In carrying out the present invention, it is necessary to additionally provide a molding machine (pressure member 16, etc.) for molding the protrusion 5, and to change (adjust) the stroke amount of the pressure member 16 each time. However, the cost and effort required for this are much lower than when changing the arrangement positions of the processing machines 12 to 15, the feed amount of the flat wire 2, etc. according to the overall length of the segment coil 1 to be manufactured. . Furthermore, if the present invention is adopted, as described above, there is no need to change the arrangement positions of the various processing machines 12 to 15 used to produce the coil material 6, so the processing machines 12 to 15 are movable It is possible to adopt a fixed-point installation type, which has superior processing accuracy and durability. Therefore, it is possible to stably and accurately mass-produce the coil materials 6 and the segment coils 1 having different overall lengths.

From the above, according to the method for manufacturing the segment coil 1 according to the present invention, even when using the flat wire 2 unwound from the same bobbin 11, multiple types of segment coils 1 having different overall lengths L can be efficiently manufactured. Moreover, it can be manufactured (mass produced) with high precision. Thereby, a stator coil having a predetermined quality and, by extension, an electric motor can be stably manufactured.

Although the method for manufacturing the segment coil 1 according to the embodiment of the present invention has been described above, various changes can be made to the method for manufacturing the segment coil 1 according to the present invention without departing from the gist thereof. .

For example, the processing steps sequentially performed on the rectangular wire 2 in order to remove the insulating film 4 in the material manufacturing step S2 are just an example, and the insulating film 4 may be removed in other processing steps (using other processing machines). may be removed.

Further, in the embodiment described above, the inverted V-shaped (pointed) protrusion 5 is formed into the rectangular wire 2, but the shape of the protrusion 5 can be arbitrarily selected. However, considering that the protrusion 5 is used for positioning during the bending step S3, it is preferable that the protrusion 5 is formed into an inverted V shape.

1 Segment coil 2 Flat wire (flat wire with film)
3 Conductor wire 4 Insulating film 5, 5A, 5B, 5C Projecting part 6, 6A, 6B, 6C Coil material 10 Processing equipment 12, 13, 14, 15 Processing machine 16 Pressure member A1 1st area A2 2nd area L segment coil Total length dimension S1 Projection forming process S2 Material manufacturing process S3 Bending process

Claims (2)

A method for manufacturing a segment coil having a U-shape consisting of a pair of mutually parallel straight parts and a mountain part connecting these parts, and in which a conducting wire is exposed at the free end of the straight part, the method comprising:
A long rectangular wire fed in the longitudinal direction is cut into a predetermined length by sequentially performing predetermined processing using a plurality of processing machines arranged at intervals along the longitudinal direction. A material manufacturing process in which coil materials with conducting wires exposed at both ends are successively manufactured;
a bending step of bending the coil material to obtain the segment coil;
a protrusion forming step of forming a protrusion protruding in a direction perpendicular to the longitudinal direction on the rectangular wire before being introduced into the material manufacturing step;
A method for producing a segment coil, characterized in that the amount of protrusion of the protrusion formed in the protrusion forming step is changed depending on the overall length of the segment coil to be produced. 2. The method for manufacturing a segment coil according to claim 1, wherein the protruding portion is formed in a longitudinally central portion of the coil material.

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