JP7596974B2 - Armature manufacturing apparatus and armature manufacturing method - Google Patents

Description

The present invention relates to an armature manufacturing device and an armature manufacturing method.

Conventionally, armatures such as the stator of a rotating electric machine include a cylindrical iron core with multiple slots, a coil arranged inside the slots, and an insulating sheet arranged between the inner surface of the slot and the coil.

Specifically, the core has a cylindrical yoke and a plurality of teeth protruding radially inward from the yoke, and the slots are formed between adjacent teeth.
For example, Patent Document 1 discloses that the coil is formed by using a pressing tool to press a conductor arranged to extend axially inside a slot in a radial direction toward the inner surface of the slot, thereby plastically deforming the coil.

JP 2021-87284 A

However, conventional pressing jigs, including the pressing jig disclosed in Patent Document 1, have a flat pressing surface that is perpendicular to the radial direction of the iron core. When using such pressing jigs, there is a problem in that stress tends to concentrate on the insulating sheet at the end position of the iron core in the axial direction.

The armature manufacturing device that solves the above problem includes a cylindrical core having multiple slots, a coil arranged inside the slot, and an insulator arranged between the coil and the inner surface of the slot, and the coils are arranged in a radial direction of the core. The device includes a pressing tool that presses a conductor arranged inside the slot so as to extend in the axial direction of the core toward the inner surface of the slot in the radial direction to plastically deform the coil, and forms the coil. The pressing tool has a pressing surface that presses the portion of the conductor arranged inside the slot over the entire axial direction, and the pressing surface has a closest portion that is closest to the inner surface of the slot in the radial direction, and an inclined portion that is connected to the closest portion and inclined so as to move away from the inner surface in the radial direction as it moves away from the closest portion in the axial direction.

A method for manufacturing an armature that solves the above problem includes a cylindrical core having a plurality of slots, a coil arranged inside the slots, and an insulator arranged between the coil and the inner surface of the slot, and the coils are arranged in a radial direction of the core. The method includes a conductor arrangement process for arranging a conductor inside the slot so that the conductor extends in the axial direction of the core, and a pressing process for pressing the conductor against the inner surface of the slot with the pressing tool to plastically deform the conductor to form the coil.

According to the above configuration and method, when the pressing surface of the pressing tool presses the conductor placement portion, the load is greatest at the closest portion. In addition, because the pressing surface of the pressing tool has an inclined portion, the load is smaller at the end of the pressing surface that is farther from the closest portion in the axial direction than at the closest portion. In addition, because the pressing surface has an inclined portion, abrupt changes in the load in the axial direction are suppressed. As a result, it is possible to suppress stress concentration in the insulator at the end position of the iron core in the axial direction. Therefore, stress concentration in the insulator can be suppressed.

FIG. 1 is a cross-sectional view showing a stator according to an embodiment. FIG. 2 is an enlarged cross-sectional view showing a part of FIG. FIG. 3 is an exploded perspective view showing the stator core and the segment coils in the same embodiment in a separated state. FIG. 4 is a cross-sectional perspective view showing the segment coils arranged inside the slots of the stator core and the pressing jig separated from each other in the embodiment. FIG. 5 is a cross-sectional view showing the segment coils arranged inside the slots of the stator core in the embodiment and the pressing jig separated from each other. FIG. 6 is a cross-sectional view showing a state in which five segment coils are arranged inside the slots of the stator core in the same embodiment. FIG. 7 corresponds to FIG. 6 and is a cross-sectional view showing the five segment coils and the pressing jig of the same embodiment separated from each other. FIG. 8 corresponds to FIG. 6 and is a cross-sectional view showing the state in which the five segment coils of the same embodiment are pressed by a pressing jig. FIG. 9 corresponds to FIG. 6 and is a cross-sectional view showing the state in which the eight segment coils of the same embodiment are pressed by a pressing jig. FIG. 10 is a cross-sectional view taken along line 10A-10A in FIG. FIG. 11 is a diagram corresponding to FIG. 10 and is a cross-sectional view showing a state in which a segment coil is pressed by a conventional pressing jig. FIG. 12 is a cross-sectional view showing the state in which the segment coil is pressed by the first modified example. FIG. 13 is a cross-sectional view showing the state in which the segment coil is pressed by the second modified example. FIG. 14 is a cross-sectional view showing the state in which the segment coil is pressed by the third modified example. FIG. 15 is a cross-sectional view showing the state in which the segment coil is pressed by the fourth modified example.

Hereinafter, with reference to FIGS. 1 to 11, an embodiment in which an armature manufacturing apparatus and an armature manufacturing method are embodied as a stator manufacturing apparatus and a stator manufacturing method will be described.
In the drawings, for the convenience of explanation, some components may be shown exaggerated or simplified, and the dimensional ratios of each part may differ from the actual ones.

(Stator 10)
As shown in Figures 1 and 2, the stator 10 includes a stator core 20, a coil 30, and a plurality of insulating sheets 50. The stator core 20 is cylindrical. The coil 30 is wound around the stator core 20. Each insulating sheet 50 covers the outer surface of the coil 30. The stator core 20 corresponds to an "iron core."

The stator 10 of this embodiment is used in a three-phase synchronous rotating electric machine, and is provided so as to surround a rotor (not shown).
Hereinafter, the axial direction, radial direction, and circumferential direction of the stator core 20 will be simply referred to as the axial direction, radial direction, and circumferential direction, respectively.

(Stator core 20)
The stator core 20 has a yoke 21, a plurality of teeth 22, and a plurality of slots 23. The yoke 21 is cylindrical. The plurality of teeth 22 protrude radially inward from the yoke 21 and are spaced apart from one another in the circumferential direction. One slot 23 is formed between each pair of adjacent teeth 22 in the circumferential direction. Each slot 23 is open radially inward and on both sides in the axial direction. The stator core 20 of this embodiment has a total of 48 slots 23.

As shown in FIG. 1, the stator core 20 has three fixing portions 24 that protrude radially outward from the yoke 21. The three fixing portions 24 are spaced apart from one another in the circumferential direction. Each fixing portion 24 has a bolt hole 24a that passes through the fixing portion 24 in the axial direction. A bolt (not shown) is inserted into the bolt hole 24a and fastened to a housing (not shown), thereby fixing the stator core 20 to the housing.

The stator core 20 is formed, for example, by joining together a plurality of electromagnetic steel plates that are stacked in the axial direction.
(Coil 30)
The coil 30 is configured with three phase windings constituting a U phase, a V phase, and a W phase. Each phase winding is wound across a plurality of teeth 22.

The coil 30 has a conductor and an insulating coating that covers the outer circumference of the conductor. The conductor is made of a metal material such as an aluminum alloy. The insulating coating is not shown in each figure.

As shown in FIGS. 3 and 4 , the coil 30 has a plurality of arrangement portions 31 , a plurality of first coil ends 32 , and a plurality of second coil ends 33 .
The arrangement portions 31 are arranged inside the slots 23. The arrangement portions 31 extend linearly in the axial direction. Eight arrangement portions 31 are provided inside the slots 23 and aligned in the radial direction.

As shown in Figures 2 and 4, the cross-sectional shape of the coil 30 perpendicular to the length direction is a rectangle having long and short sides. The long side of the cross-sectional shape of the arrangement portion 31 extends in the width direction of the slot 23, and the short side of the cross-sectional shape of the arrangement portion 31 extends in the radial direction. The long side of the arrangement portion 31 is the same as the opening width of the insulating sheet 50. The width direction of the slot 23 is the direction perpendicular to both the axial direction and the radial direction.

The first coil end 32 extends from the arrangement portion 31 in one axial direction. The first coil end 32 protrudes from the slot 23 in one axial direction. Although not shown, the first coil end 32 is bent in the circumferential direction to connect two arrangement portions 31 arranged inside two different slots 23.

The second coil end 33 extends from the arrangement portion 31 on the opposite side of the axial direction. The second coil end 33 protrudes from the slot 23 on the other side opposite the axial direction and is bent in the circumferential direction. The second coil end 33 connects two arrangement portions 31 arranged inside two different slots 23.

(Segment coil 40)
2 and 4, each phase winding of the coil 30 described above is formed by joining together a plurality of segment coils 40. In this embodiment, eight segment coils 40 are arranged radially inside one slot 23.

As shown in FIG. 3, the segment coil 40 has two straight sections 34 that extend in parallel and a connecting section 35 that connects the ends of the two straight sections 34. The segment coil 40 is U-shaped.

The two straight portions 34 of such a segment coil 40 are inserted into two different slots 23 from one side in the axial direction. After that, a part of the straight portion 34 protruding from the slot 23 is bent in one or the other circumferential direction. Then, the straight portion 34 of one segment coil 40 is joined to the straight portion 34 of another segment coil 40. In this way, each phase winding is formed.

Each straight section 34 is composed of a first coil end 32, a placement section 31, and a second coil end 33. Thus, the segment coil 40 has two placement sections 31 that are respectively placed inside two different slots 23, two first coil ends 32 that are independent of each other, and two second coil ends 33. The two first coil ends 32 in the segment coil 40 extend in a cantilevered manner from the two placement sections 31. The two second coil ends 33 are connected by a connecting section 35 at the portions of the two placement sections 31 opposite the first coil ends 32. The segment coil 40 corresponds to a "conductor wire."

(Insulating sheet 50)
As shown in Fig. 2, one insulating sheet 50 is disposed inside each slot 23. The insulating sheet 50 is disposed between the inner surface of the slot 23 and the outer surface of the coil 30. The insulating sheet 50 covers the entire inner surface of the slot 23. The insulating sheet 50 is open on the radially inner side and on both sides in the axial direction, similar to the slot 23, for example. Both ends of the insulating sheet 50 in the axial direction protrude from the slot 23. The insulating sheet 50 is made of a synthetic resin material. The insulating sheet 50 corresponds to an "insulator".

(Stator manufacturing device 60)
4 and 5, a stator manufacturing apparatus 60 (hereinafter referred to as the manufacturing apparatus 60) includes a pressing jig 70. The pressing jig 70 presses the segment coils 40 arranged inside the slots 23 so as to extend in the axial direction in the slots 23 in the radial direction toward the inner surface 23a of the slots 23 to plastically deform them.

(Pressing jig 70)
4 and 5, the pressing jig 70 has a plate shape extending in both the axial direction and the radial direction. The axial length of the pressing jig 70 is greater than the axial length of the segment coil 40. The width of the pressing jig 70 is a constant size in the axial direction and is approximately the same as the opening width of the insulating sheet 50.

The pressing jig 70 may be made of, for example, a metal material such as an iron-based material.
As shown in Figures 4 and 5, the pressing jig 70 has a pressing surface 71 that presses the arrangement portion 31 of the segment coil 40 over the entire axial direction.

The pressing surface 71 has a closest portion 72 , a first inclined portion 75 , and a second inclined portion 76 .
The closest portion 72 is a portion of the pressing surface 71 that is closest to the inner surface 23a of the slot 23 in the radial direction.

The closest portion 72 is a flat portion 73 perpendicular to the radial direction. That is, the closest portion 72 extends in both the axial direction and the width direction of the slot 23.
The closest portion 72 is provided between the two ends 20a, 20b of the stator core 20 in the axial direction.

The first inclined portion 75 and the second inclined portion 76 are connected to the closest portion 72 and are inclined so as to move away from the inner surface 23a in the radial direction as they move away from the closest portion 72 in the axial direction.

The first inclined portion 75 is continuous with a first end 72 a of the closest portion 72 in the axial direction, i.e., the end on the first coil end 32 side.
The first inclined portion 75 extends outward beyond the end 20a on the first coil end 32 side of both ends 20a, 20b of the stator core 20 in the axial direction.

The second inclined portion 76 is connected to a second end 72 b opposite the first end 72 a of the closest portion 72 in the axial direction, that is, the end on the second coil end 33 side.
The second inclined portion 76 extends outward beyond the end 20b on the second coil end 33 side of both ends 20a, 20b of the stator core 20 in the axial direction.

Here, the angle α2 formed by the imaginary straight line V extending in the axial direction and the second inclined portion 76 is larger than the angle α1 formed by the imaginary straight line V and the first inclined portion 75 (α2>α1).
(Method of manufacturing the stator)
The method for manufacturing a stator includes an insulating sheet arrangement step, a coil arrangement step, a pressing step, and a joining step. In this embodiment, the insulating sheet arrangement step, the coil arrangement step, the pressing step, and the joining step are performed in this order. However, the coil arrangement step and the pressing step are repeated multiple times in this order.

(Insulating sheet placement process)
6, in the insulating sheet disposing step, the insulating sheet 50 is disposed inside the slot 23. At this time, the insulating sheet 50 may be inserted into the slot 23 from the radially inner side, or may be inserted into the slot 23 from the axial direction.

(Coil placement process)
In the coil arrangement process, a plurality of segment coils 40 are arranged inside the slot 23. In this embodiment, first, of the total eight segment coils 40 arranged inside one slot 23, five segment coils 40 are arranged radially inside the slot 23.

In the coil placement process, the placement portion 31 having a width smaller than the width of the slot 23, more specifically, a width smaller than the opening width of the insulating sheet 50, is placed inside the slot 23. Therefore, a gap is provided between the placement portion 31 and the insulating sheet 50 in the width direction of the slot 23. The coil placement process corresponds to the "conductor placement process."

(Pressing process)
7 and 8 , in the pressing process, the placement portion 31 of the segment coil 40 is pressed toward the inner surface 23a of the slot 23 on the radially outer side by a pressing jig 70. This causes the placement portion 31 to plastically deform along the inner surface 23a of the slot 23. This eliminates the gap between the placement portion 31 and the insulating sheet 50 described above. Therefore, the width of the placement portion 31 becomes the same as the opening width of the insulating sheet 50.

As shown in FIG. 9, next, the coil arrangement process and the pressing process are performed in this order for the two remaining segment coils 40, and then the coil arrangement process and the pressing process are performed in this order for the remaining one segment coil 40. Note that the coil arrangement process and the pressing process may be performed in this order for the three remaining segment coils 40.

(Joining process)
Although not shown, in the joining process, one first coil end 32 in each segment coil 40 is twisted in one circumferential direction by an annular twisting jig that engages with each first coil end 32, and the other first coil end 32 is twisted in the other circumferential direction. As a result, an end of a first coil end 32 in a segment coil 40 and an end of a first coil end 32 in a segment coil 40 other than the segment coil 40 are adjacent in the radial direction. These ends are then joined together by welding to manufacture the coil 30.

Next, the operation of this embodiment will be described.
As shown in FIG. 10 , the load applied when the pressing surface 71 of the pressing jig 70 presses the placement portion 31 of the segment coil 40 is greatest at the closest portion 72 .

In addition, since the pressing surface 71 of the pressing jig 70 has a first inclined portion 75 and a second inclined portion 76, the load is smaller at the end of the pressing surface 71 that is farther away from the closest portion 72 in the axial direction than at the closest portion 72.

Furthermore, since the pressing surface 71 has the first inclined portion 75 and the second inclined portion 76, the load is prevented from suddenly changing in the axial direction.
For these reasons, it is possible to prevent stress from concentrating on the insulating sheet 50 at the ends 20a, 20b of the stator core 20 in the axial direction.

On the other hand, as shown in FIG. 11, a conventional pressing tool 170 has a flat pressing surface 171 perpendicular to the radial direction of the stator core 20. In this case, stress tends to concentrate on the insulating sheet 50 at the ends 20a and 20b of the stator core 20 in the axial direction.

Next, the effects of this embodiment will be described.
(1) The pressing jig 70 of the manufacturing device 60 has a pressing surface 71 that presses the placement portion 31 of the segment coil 40 that is placed inside the slot 23 over the entire axial direction. The pressing surface 71 has a closest portion 72 and a first inclined portion 75 and a second inclined portion 76 as inclined portions.

According to this configuration, by achieving the above-mentioned effect, it is possible to suppress the concentration of stress on the insulating sheet 50 .
(2) The closest portion 72 has a flat portion 73 extending in the axial direction.

This configuration makes it possible to expand the area of the arrangement section 31 that is pressed by the closest portion 72. Therefore, by increasing the proportion of the closest portion 72 in the pressing surface 71, i.e., the proportion of the flat portion 73, it is possible to increase the proportion of the portion of the arrangement section 31 that is pressed by a uniform load. Therefore, the space factor of the coil 30 can be increased.

(3) The closest portion 72 is provided between the positions of both ends 20a, 20b of the stator core 20 in the axial direction. The first inclined portion 75 and the second inclined portion 76 as inclined portions extend to positions outside the ends 20a, 20b of the stator core 20 in the axial direction.

With this configuration, the load acting on the insulating sheet 50 at the ends 20a and 20b of the stator core 20 in the axial direction is released by the inclined portion. Therefore, it is possible to further prevent stress from concentrating on the insulating sheet 50 at the ends 20a and 20b of the stator core 20 in the axial direction.

(4) The second inclined portion 76 extends toward the second coil end 33 in the axial direction.
In the segment coil 40, the two second coil ends 33 connected by the connecting portion 35 are more likely to receive a large reaction force when pressed by the pressing jig 70 than the two first coil ends 32 that are independent of each other, and are less likely to be plastically deformed. Therefore, when the pressing surface 71 of the pressing jig 70 presses the arrangement portion 31 of the segment coil 40, a larger load acts on the end of the arrangement portion 31 on the second coil end 33 side than on the end of the first coil end 32 side in order to resist the above-mentioned reaction force. As a result, stress concentration is particularly likely to occur in the portion of the insulating sheet 50 that covers the end of the arrangement portion 31 on the second coil end 33 side.

In this regard, the above-described configuration makes it possible to suppress stress concentration in the above-described portion of the insulating sheet 50 where stress concentration is particularly likely to occur.
(5) The first inclined portion 75 extends outwardly beyond the end 20a on the first coil end 32 side of both ends 20a, 20b of the stator core 20 in the axial direction. The second inclined portion 76 extends outwardly beyond the end 20b on the second coil end 33 side of both ends 20a, 20b of the stator core 20 in the axial direction. The angle α2 between an imaginary line V extending in the axial direction and the second inclined portion 76 is greater than the angle α1 between the imaginary line V and the first inclined portion 75 (α2>α1).

With this configuration, the load acting on the portion of the insulating sheet 50 covering the end 20b on the second coil end 33 side in the arrangement portion 31 is further released by the first inclined portion 75, which forms an angle with the virtual line V that is larger than that of the second inclined portion 76. Therefore, stress concentration on the above portion can be further suppressed.

(6) The method for manufacturing the stator includes a segment coil arrangement step of arranging the arrangement portion 31 of the segment coil 40 inside the slot 23 so that it extends in the axial direction of the stator core 20. The method for manufacturing the stator includes a pressing step of pressing the arrangement portion 31 toward the inner surface 23a of the slot 23 with a pressing jig 70 to plastically deform the arrangement portion 31 to form the coil 30.

According to this method, by achieving the above-mentioned effect, it is possible to suppress the concentration of stress on the insulating sheet 50 .
<Example of change>
This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

The angle α2 between the virtual line V and the second inclined portion 76 is not limited to being greater than the angle α1 between the virtual line V and the first inclined portion 75, and may be less than or equal to the angle α1. For example, when a straight conductor without a connecting portion 35 is used instead of the segment coil 40, the angle α2 between the virtual line V and the second inclined portion 76 may be the same as the angle α1 between the virtual line V and the first inclined portion 75 (α1 = α2).

In the pressing surface 71 of the pressing jig 70 of this embodiment, the first inclined portion 75 may be omitted, and the portion corresponding to the first inclined portion 75 may be formed by the closest portion 72 .
For example, when a straight conductor without the connecting portion 35 is used instead of the segment coil 40, either the first inclined portion 75 or the second inclined portion 76 may be omitted. Even in this case, since the inclined portion is provided, the load is smaller at the end of the pressing surface 71 that is farther from the nearest portion 72 in the axial direction than at the nearest portion 72. This makes it possible to suppress stress concentration on the insulating sheet 50 at one end of the stator core 20 in the axial direction.

The first inclined portion 75 does not have to extend beyond the end 20a of the stator core 20 on the first coil end 32 side in the axial direction. The second inclined portion 76 does not have to extend beyond the end 20b of the stator core 20 in the axial direction.

As shown in Figures 12 and 13, for example, the entire second inclined portion 76 is provided inside the end 20b of the stator core 20 in the axial direction. In addition, the pressing surface 71 has an outer flat portion 78 on the opposite side of the second inclined portion 76 from the closest portion 72. The outer flat portion 78, like the closest portion 72, extends in both the axial direction of the stator core 20 and the width direction of the slot 23.

The closest portion 72 does not have to be a flat portion extending in the axial direction.
As shown in FIG. 14, the closest portion 72 may not have a substantial length in the axial direction.

Also, as shown in FIG. 15, the entire pressing surface 71 may be inclined so that it is positioned radially inward toward the second coil end 33 in the axial direction. In this case, the portion of the pressing surface 71 that corresponds to the position of the end 20a of the stator core 20 in the axial direction becomes the closest portion 72, and the portion other than the closest portion 72 becomes the second inclined portion 76.

The insulator is not limited to the insulating sheet 50 exemplified in this embodiment. The insulator may be anything that is placed between the inner surface of the slot 23 and the coil 30, and may be composed of a coating applied to the entire inner surface of the slot 23.

10... Stator 20... Stator core (iron core)
20a...First end 20b...Second end 21...Yoke 22...Teeth 23...Slot 23a...Inner surface of slot 24...Fixed portion 24a...Bolt hole 30...Coil 31...Arrangement portion 32...First coil end 33...Second coil end 34...Straight portion 35...Connecting portion 40...Segment coil 50...Insulating sheet (insulator)
60: Stator manufacturing device 70: Pressing jig 71: Pressing surface 72: Closest contact portion 72a: First end 72b: Second end 73: Flat portion 75: First inclined portion 76: Second inclined portion

Claims (7)

An apparatus for manufacturing an armature comprising: a cylindrical core having a plurality of slots; a coil disposed inside the slot; and an insulator disposed between an inner surface of the slot and the coil, the coil being disposed in a radial direction of the core;
a pressing tool that presses a conductor arranged inside the slot so as to extend in the axial direction of the core toward an inner surface of the slot in the radial direction to plastically deform the coil,
the pressing jig has a pressing surface that presses an arrangement portion of the conductor that is arranged inside the slot over the entire axial direction,
the pressing surface has a closest portion that is closest to the inner surface of the slot in the radial direction, and an inclined portion that is connected to the closest portion and inclined so as to move away from the inner surface in the radial direction as it moves away from the closest portion in the axial direction.
Armature manufacturing equipment. The closest portion is a flat portion extending in the axial direction.
An apparatus for manufacturing an armature according to claim 1. The inclined portion extends outward beyond an end of the iron core in the axial direction.
3. An armature manufacturing apparatus according to claim 1 or 2. the closest portion is provided between both ends of the iron core in the axial direction,
the inclined portion has a first inclined portion connected to a first end of the closest portion in the axial direction, and a second inclined portion connected to a second end of the closest portion on an opposite side to the first end in the axial direction,
The armature manufacturing apparatus according to any one of claims 1 to 3. The coil is a segment coil having two arrangement portions that are respectively arranged inside two different slots, two first coil ends that extend from the two arrangement portions to one side in the axial direction and are independent of each other, two second coil ends that extend from the two arrangement portions to the side opposite to the one side in the axial direction, and a connecting portion that connects the second coil ends to each other,
The inclined portion extends toward the second coil end in the axial direction.
The armature manufacturing apparatus according to any one of claims 1 to 4. the closest portion is provided at a position between both ends of the iron core in the axial direction,
the inclined portion has a first inclined portion connected to a first end of the closest portion in the axial direction, and a second inclined portion connected to a second end of the closest portion on an opposite side to the first end in the axial direction,
the first inclined portion extends outwardly beyond one of both ends of the iron core in the axial direction that is closer to the first coil end,
the second inclined portion extends outwardly beyond one of both ends of the iron core in the axial direction that is closer to the second coil end,
an angle between a virtual line extending in the axial direction and the second inclined portion is larger than an angle between the virtual line and the first inclined portion;
6. An armature manufacturing apparatus according to claim 5. A method for manufacturing an armature comprising: a cylindrical core having a plurality of slots; a coil disposed inside the slot; and an insulator disposed between an inner surface of the slot and the coil, the coil being disposed in a radial direction of the core, the method comprising the steps of:
a conductor arrangement step of arranging conductors inside the slots so as to extend in an axial direction of the core;
and a pressing step of pressing the conductor wire against the inner surface of the slot with the pressing tool according to any one of claims 1 to 6 to plastically deform the conductor wire to form the coil.
Manufacturing method of armatures.

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