Method for bending segment coils and apparatus for bending segment coils

Abstract

To provide a bending method capable of easily preventing an insulation coating of a segment coil from being damaged.SOLUTION: A bending method for a segment coil 10 includes a first operation for twisting a first coil end row 28R1 in one direction in a circumferential direction and a second operation for twisting a second coil end row 28R2, which is adjacent to the first coil end row in a radial direction of a stator core, in the other direction in the circumferential direction. The timing in which the first coil end row 28R1 arrives at a movement completion position by the first operation is made different from the timing in which the second coil segment 28R2 arrives at a movement completion position by the second operation.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a method for bending a segment coil and an apparatus for bending a segment coil.

Background Art

[0002] In the manufacturing process of a stator, bending is performed to form the coil ends of a segment coil inserted into the stator core into a predetermined shape. In this bending, among a plurality of coil end rows arranged in the radial direction of the stator core, the adjacent coil end rows are twisted and bent in opposite directions in the circumferential direction. Patent Documents 1 and 2 disclose techniques for preventing damage to the insulating coating of the segment coil due to contact when the coil ends of adjacent coil end rows pass by each other.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in Patent Document 1, it is necessary to process the segment coil into a special shape. In Patent Document 2, it is necessary to process the jig used for bending into a special shape. Therefore, it is required to more easily prevent damage to the insulating coating of the segment coil.

[0005] An object of the present invention is to solve the above-described problems.

Means for Solving the Problems

[0006] A first aspect of the present disclosure is a method for bending a segment coil, in which a plurality of coil ends of a plurality of segment coils inserted into the stator core of a rotating electric machine are twisted and bent in the circumferential direction of the stator core, the method comprising: a first operation of twisting and bending a first coil end row consisting of a plurality of first coil ends arranged in the circumferential direction from the plurality of coil ends in one direction of the circumferential direction; and a second operation, in parallel with the first operation, of twisting and bending a second coil end row consisting of a plurality of second coil ends arranged in the circumferential direction from the plurality of coil ends, which is adjacent to the first coil end row in the radial direction of the stator core, in the other direction of the circumferential direction, wherein the timing at which the first coil end row reaches the completed position by the first operation and the timing at which the second coil end row reaches the completed position by the second operation are different.

[0007] A second aspect of the present disclosure is a rotating electric machine in which a first operation is performed to twist and bend a first coil end row, consisting of a plurality of first coil ends arranged in the circumferential direction of the stator core, from among a plurality of coil ends that protrude from the stator core in the axial direction of the stator core of a plurality of segment coils inserted through the stator core, in a first direction which is one of the circumferential directions, and in parallel with the first operation, a second operation is performed to twist and bend a second coil end row, consisting of a plurality of second coil ends arranged in the circumferential direction of the plurality of coil ends, which is adjacent to the first coil end row in the radial direction of the stator core, in a second direction which is the other of the circumferential directions. A segment coil bending apparatus comprising: a first jig that engages with the first coil end row; a second jig that engages with the second coil end row; a first drive unit that rotates the first jig in a first direction to perform the first operation; a second drive unit that rotates the second jig in a second direction to perform the second operation; and a control unit that controls the first drive unit and the second drive unit, wherein the control unit causes the timing at which the first coil end row reaches the completed position by the first operation to be different from the timing at which the second coil end row reaches the completed position by the second operation. [Effects of the Invention]

[0008] According to the present invention, by delaying the second twisting and bending operation of the second coil end row relative to the first twisting and bending operation of the first coil end row, strong contact between the thickest and most deformed parts of the coil ends can be avoided. Therefore, damage to the insulating coating at the thickest and most deformed parts of the coil ends can be prevented. According to the present invention, damage to the insulating coating of the segment coil can be easily prevented. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a perspective view of a segment coil. [Figure 2] Figure 2 is a perspective view of the stator core and multiple segment coils. [Figure 3] Figure 3 is a schematic diagram of a bending apparatus according to an embodiment of the present invention. [Figure 4] Figure 4 is a perspective view of multiple segment coils that have undergone twist bending. [Figure 5] Figure 5 illustrates the bending process for segment coils. [Figure 6] Figure 6 illustrates the time difference between the first and second actions. [Figure 7] Figure 7 illustrates the contact between the bulging portions of the segment coils. [Figure 8] Figure 8A illustrates the intersection of the first segment coil. Figure 8B illustrates the intersection of the fifth segment coil. [Figure 9] Figure 9A shows an image of the ideal behavior of the coil end. Figure 9B shows an image of the actual behavior of the coil end when there is no time difference. Figure 9C shows an image of the actual behavior of the coil end when there is a time difference. [Modes for carrying out the invention]

[0010] As shown in Figure 1, the segment coil 10 has a roughly U-shape. The segment coil 10 has a conductor portion 12 and an insulating coating 14. The insulating coating 14 is, for example, enamel. The segment coil 10 has a pair of legs 16 and a turn portion 17. The pair of legs 16 are straight and extend parallel to each other. At the tip of each leg 16, there is a peeled portion 18 where the conductor portion 12 is exposed by peeling off the insulating coating 14. Hereinafter, the part of the segment coil 10 that has the insulating coating 14 will also be called the "covered portion 15". The turn portion 17 is the part of the segment coil 10 that connects the pair of legs 16. A meandering crank portion 20 is formed in the turn portion 17.

[0011] As shown in Figure 2, the stator core 24 of the rotating electric machine has a plurality of slots 26. In the following description, the circumferential, axial, and radial directions of the stator core 24 may be simply referred to as "circumferential direction," "axial direction," and "radial direction," respectively. In the stator core 24, the plurality of slots 26 are provided at intervals in the circumferential direction. Multiple segment coils 10 are inserted into the plurality of slots 26. In this case, a pair of legs 16 of the segment coils 10 are inserted into separate slots 26.

[0012] As shown in Figure 3, with multiple segment coils 10 inserted into the stator core 24, a pair of legs 16 of each segment coil 10 protrude axially from the slots 26 of the stator core 24 (see also Figure 2). Hereinafter, the portion of each leg 16 that protrudes from the slots 26 will be referred to as the "coil end 28".

[0013] Multiple segment coils 10 are arranged in the circumferential direction of the stator core 24. Furthermore, multiple segment coils 10 are arranged in the radial direction of the stator core 24. Therefore, multiple coil ends 28 arranged in the circumferential direction constitute a coil end row 28R. In the stator core 24, multiple coil end rows 28R are arranged radially. In this embodiment, eight coil end rows 28R are arranged radially. Hereafter, for the eight coil end rows 28R, the innermost coil end row 28R in the radial direction will be designated as the 1st layer, and the outermost coil end row 28R in the radial direction will be designated as the 8th layer. That is, from the inside to the outside in the radial direction, the coil end rows 28R from the 1st layer to the 8th layer are arranged in this order.

[0014] Multiple segment coils 10 arranged in this manner are subjected to a twisting bend (hereinafter simply referred to as "bending"). As shown in Figure 4, the bending process causes radially adjacent coil end rows 28R to be twisted and bent in opposite directions in the circumferential direction. The twisted coil ends 28 are joined together by appropriate means such as TIG welding at the tips (separated portions 18) of the corresponding coil ends 28.

[0015] The bending process for the plurality of segment coils 10 can be performed using the bending device 30 shown in FIG. 3. The bending device 30 includes a first station 30A and a second station (not shown). The first station 30A performs bending on the segment coils 10 of the outer four layers (from the fifth layer to the eighth layer). The second station performs bending on the segment coils 10 of the inner four layers (from the first layer to the fourth layer). The basic configuration of the second station is the same as that of the first station 30A. Therefore, hereinafter, the configuration of the first station 30A will be typically described.

[0016] The first station 30A includes a lifting unit 32 and a twisting and bending unit 34. The lifting unit 32 is a mechanism for relatively displacing the stator core 24 and the twisting and bending unit 34 in the axial direction. The lifting unit 32 has a lifting table 36 and a lifting actuator 38. The lifting table 36 raises and lowers the stator core 24. The lifting table 36 has a substantially ring-shaped mounting plate 40, a holding jig 42 for holding the stator core 24, and a base 44 for supporting the mounting plate 40 and the holding jig 42. The lifting actuator 38 raises and lowers the base 44. The mounting plate 40 and the holding jig 42 are raised and lowered together with the base 44 by the lifting actuator 38. Note that the mechanism for relatively displacing the stator core 24 and the twisting and bending unit 34 in the axial direction (vertical direction) may be provided in the twisting and bending unit 34 itself. That is, the twisting and bending unit 34 may have a function of moving in the axial direction. In this case, the portion holding the stator core 24 does not move in the axial direction.

[0017] The twisting and bending unit 34 includes a plurality of twisting and bending jigs 46, a plurality of rotation drive units 48, and a control device 50. The plurality of twisting and bending jigs 46 are jigs for gripping a plurality of coil ends 28 protruding from the slots 26 of the stator core 2 and twisting the segment coils 10. The plurality of twisting and bending jigs 46 engage with a plurality of coil end rows 28R respectively.

[0018] Each of the plurality of twisting and bending tools 46 has a substantially cylindrical shape. The plurality of twisting and bending tools 46 are arranged concentrically. The plurality of twisting and bending tools 46 are rotatably supported by a column 54 via a plurality of bearings 52. The plurality of twisting and bending tools 46 include a first twisting and bending tool 461, a second twisting and bending tool 462, a third twisting and bending tool 463, and a fourth twisting and bending tool 464.

[0019] Each of the first twisting and bending tool 461, the second twisting and bending tool 462, the third twisting and bending tool 463, and the fourth twisting and bending tool 464 has an annular holding portion 56 that holds a plurality of coil ends 28. The holding portion 56 is provided at the lower end of each twisting and bending tool 46. The plurality of holding portions 56 are arranged concentrically. A plurality of engaging grooves 58 into which the plurality of coil ends 28 are inserted are provided at intervals in the circumferential direction on the outer peripheral portion of each holding portion 56. Each engaging groove 58 opens radially outward and downward. The radially inner side of each engaging groove 58 is closed.

[0020] The plurality of rotation driving portions 48 individually rotate the plurality of twisting and bending tools 46 in the circumferential direction. Each rotation driving portion 48 includes a motor 60 and a gear 62. The motor 60 is supported by the column 54. The gear 62 is fixed to the output shaft portion of the motor 60. The plurality of rotation driving portions 48 include a first rotation driving portion 481, a second rotation driving portion 482, a third rotation driving portion 483, and a fourth rotation driving portion 484. The first rotation driving portion 481, the second rotation driving portion 482, the third rotation driving portion 483, and the fourth rotation driving portion 484 rotate the first twisting and bending tool 461, the second twisting and bending tool 462, the third twisting and bending tool 463, and the fourth twisting and bending tool 464, respectively.

[0021] The plurality of rotation driving portions 48 rotate the tools adjacent to each other in the radial direction among the plurality of twisting and bending tools 46 in opposite directions in the circumferential direction. That is, the rotation directions of the first twisting and bending tool 461 and the third twisting and bending tool 463 rotated by the first rotation driving portion 481 and the third rotation driving portion 483 are opposite to the rotation directions of the second twisting and bending tool 462 and the fourth twisting and bending tool 464 rotated by the second rotation driving portion 482 and the fourth rotation driving portion 484.

[0022] The control device 50 includes an arithmetic unit 66 and a storage unit 68. The arithmetic unit 66 is composed of a processor, such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), i.e., processing circuitry.

[0023] The calculation unit 66 includes a control unit 70. The control unit 70 controls the lifting actuator 38 and a plurality of rotary drive units 48. The control unit 70 can be realized by the calculation unit 66 executing a program stored in the storage unit 68.

[0024] Furthermore, at least a portion of the control unit 70 may be implemented by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). Alternatively, at least a portion of the control unit 70 may be composed of an electronic circuit including discrete devices.

[0025] The storage unit 68 is composed of a volatile memory (not shown) and a non-volatile memory (not shown). Examples of volatile memory include RAM (Random Access Memory). The volatile memory is used as the working memory of the processor and temporarily stores data necessary for processing or calculation. Examples of non-volatile memory include ROM (Read Only Memory) and flash memory. The non-volatile memory is used as storage memory and stores programs, tables, maps, etc. At least a part of the storage unit 68 may be provided in the processor, integrated circuit, etc. as described above.

[0026] The bending device 30 (first station 30A) operates as follows. First, the basic movement of the bending device 30 will be explained.

[0027] The control unit 70 raises the lifting platform 36. As a result, the stator core 24 rises along with the lifting platform 36. As the stator core 24 rises, multiple end coils of multiple segment coils 10 are inserted into the holding parts 56 (multiple engagement grooves 58) of multiple twist bending jigs 46. Specifically, the fifth layer of coil end rows 28R is inserted into the holding part 56 of the first twist bending jig 461. The sixth layer of coil end rows 28R is inserted into the holding part 56 of the second twist bending jig 462. The seventh layer of coil end rows 28R is inserted into the holding part 56 of the third twist bending jig 463. The eighth layer of coil end rows 28R is inserted into the holding part 56 of the fourth twist bending jig 464.

[0028] In this state, the control unit 70 rotates the first twist bending jig 461, the second twist bending jig 462, the third twist bending jig 463, and the fourth twist bending jig 464 to twist-bend the coil end rows 28R from the 5th to the 8th layer in the circumferential direction. In this case, the control unit 70 twist-bends the coil end rows 28R of the 5th and 7th layers in a first direction, which is one of the circumferential directions, and twist-bends the coil end rows 28R of the 6th and 8th layers in a second direction, which is the other of the circumferential directions. In radially adjacent coil end rows 28R, the operation of twist-bending one coil end row 28R is performed in parallel with the operation of twist-bending the other coil end row 28R.

[0029] This twisting and bending motion causes multiple coil ends 28 constituting the fifth to eighth coil end rows 28R to be twisted and bent. In this case, as shown in Figure 4, each coil end 28 has an inclined portion 72 that is inclined with respect to the axial direction and an axial portion 74 that extends along the axial direction. A bent portion 76 is formed between the inclined portion 72 and the axial portion 74.

[0030] Next, the torsional bending operation by the bending device 30 shown in Figure 3 will be explained in more detail. In the following explanation, as shown in Figure 5, we will focus on two coil end rows 28R that are radially adjacent to each other among the multiple coil end rows 28R. For the sake of explanation, we will refer to one of the radially adjacent coil end rows 28R as the "first coil end row 28R1" and the other coil end row 28R as the "second coil end row 28R2". Furthermore, each of the multiple coil ends 28 that make up the first coil end row 28R1 will be referred to as the "first coil end 28a". Each of the multiple coil ends 28 that make up the second coil end row 28R2 will be referred to as the "second coil end 28b". The second coil end row 28R2 is positioned radially outward from the stator core 24 than the first coil end row 28R1.

[0031] The twist bending operation of the bending device 30 has a first operation and a second operation. The first operation is to twist and bend the first coil end row 28R1 in a first direction (R1 direction), which is one of the circumferential directions. The second operation is to twist and bend the second coil end row 28R2 in a second direction (R2 direction), which is the other of the circumferential directions, in parallel with the first operation. While the first and second operations are in progress, the multiple first coil ends 28a and the multiple second coil ends 28b pass each other (cross each other) in sequence. In the multiple twist bending jigs 46, one of the twist bending jigs 46 that are radially adjacent to each other is called the "first jig G1", and the other of the radially adjacent twist bending jigs 46 is called the "second jig G2". Among the multiple rotational drive units 48, the drive unit that rotates the first jig G1 in the first direction to perform the first operation is called the "first drive unit D1". Of the multiple rotary drive units 48, the drive unit that rotates the second jig G2 in the second direction to perform the second operation is called the "second drive unit D2".

[0032] The control unit 70 makes the timing at which the first coil end row 28R1 reaches the completed position by the first operation and the timing at which the second coil end row 28R2 reaches the completed position by the second operation different. Hereinafter, the former timing will also be called the "first timing," and the latter timing will also be called the "second timing."

[0033] Specifically, as shown in Figure 6, the control unit 70 starts the second operation with a predetermined time difference T after the start of the first operation. In this case, the movement speed of the first coil end row 28R1 due to the first operation and the movement speed of the second coil end row 28R2 due to the second operation are the same. Therefore, the second coil end row 28R2 reaches the completed movement position later than the first coil end row 28R1. In the case of the bending apparatus 30 shown in Figure 2, the control unit 70 sequentially shifts the rotation start timing of the first twist bending jig 461, the second twist bending jig 462, the third twist bending jig 463, and the fourth twist bending jig 464 by a time difference T. The time difference T is, for example, 0.2 seconds or more, although this varies depending on the conditions.

[0034] By starting the second operation with a predetermined time difference T after the start of the first operation, strong contact between the thickened and deformed portions of the coil ends 28 can be avoided. This prevents damage to the covering portion 15 at the thickened and deformed portions of the coil ends 28. The reason for this is as follows.

[0035] As shown in Figure 4, the bending process creates a bent portion 76 between the inclined portion 72 and the axial portion 74 of the coil end 28. The tip of the covering portion 15 is located in this bent portion 76. At the final stage of the twisting bending operation for each coil end row 28R, the bending angle between the inclined portion 72 and the axial portion 74 is at its largest. Therefore, at the final stage of the twisting bending operation for each coil end 28, the tip of the covering portion 15 located in the bent portion 76 becomes the thickest in the radial direction. In particular, the portion of the tip of the covering portion 15 that is on the rear side with respect to the direction of movement of the coil end 28 becomes the thickest.

[0036] Here, referring to Figure 7, the circumstances under which peeling of the coating portion 15 may occur will be explained. In Figure 7, the bulging portion 80 is the part of the coil end 28 that has become thicker due to bending during the twisting and bending operation. Unlike this embodiment, when the first timing and the second timing are the same, at the final stage of the twisting and bending operation, the bulging portions 80 come into strong contact with each other as the first coil end 28a and the second coil end 28b pass each other for the last time. Since the peeling boundary portion 19 (see Figure 4), which is the boundary between the coating portion 15 and the peeling portion 18, is located at the bulging portion 80 of the coil end 28, peeling of the coating portion 15 may occur due to the strong contact between the bulging portions 80 of the coil ends 28. Hereinafter, peeling that may occur by this mechanism will also be referred to as "Type 1 peeling". As shown in Figure 8B, at the final stage of the twisting and bending operation, each first coil end 28a is in a state where it intersects with a predetermined number of (five in Figure 8B) second coil ends 28b. The phrase "when the first coil end 28a and the second coil end 28b finally pass each other" refers to the timing when each first coil end 28a intersects with the fifth second coil end 28b in Figure 8B during the progress of the first and second operations. Furthermore, the first coil end row 28R1 and the second coil end row 28R2 are further twisted and bent from the state shown in Figure 8B, ultimately reaching the state shown in Figure 4.

[0037] On the other hand, as in this embodiment, when the first timing and the second timing are different, the second coil end row 28R2 reaches the completed movement position after the first coil end row 28R1 has reached the completed movement position. Therefore, contact between the bulging portions 80 of the coil ends 28 can be avoided in the first coil end row 28R1 and the second coil end row 28R2. By avoiding contact between the bulging portions 80 of the coil ends 28, even if the coil ends 28 rub against each other in other parts, the surface pressure during rubbing can be reduced. This makes it possible to suppress peeling (damage) of the coating portion 15, which is the insulating coating 14.

[0038] As shown in Figure 6, the control unit 70 starts the second operation after a predetermined time difference T from the start of the first operation. In this case, the time difference T is set to a time difference that prevents the peeling of the coating portions 15 of the multiple first coil ends 28a and the multiple second coil ends 28b when the multiple first coil ends 28a and the multiple second coil ends 28b first pass each other.

[0039] Here, "when multiple first coil ends 28a and multiple second coil ends 28b first pass each other" refers to the situation shown in Figure 8A. As shown in Figure 8A, during the progress of the first and second operations, the first coil ends 28a and second coil ends 28b, which protrude from adjacent slots 26 in the circumferential direction, pass each other (cross each other). In other words, Figure 8A shows the first crossing for each first coil end 28a and each second coil end 28b.

[0040] The reason why the time difference T is set as described above is as follows:

[0041] Figures 9A and 9C schematically illustrate the situation when the first coil end 28a and the second coil end 28b first pass each other during the progression of the first and second operations. As shown in Figure 9A, the ideal behavior when twisting and bending the first coil end 28a and the second coil end 28b is an arc motion along the circumferential direction of the stator core 24. In contrast, as shown in Figures 9B and 9C, the actual behavior when twisting and bending the first coil end 28a and the second coil end 28b differs from that in Figure 9A.

[0042] Figure 9B shows an image of the actual behavior of the first coil end 28a and the second coil end 28b when there is no time difference T. The direction in which the first jig G1 (Figure 5) pushes the first coil end 28a is tangential, and the direction in which the second jig G2 (Figure 5) pushes the second coil end 28b is tangential. Therefore, when the first coil end 28a and the second coil end 28b pass each other, they are not parallel to each other, and the relative distance between the first coil end 28a and the second coil end 28b becomes small. The reason why the direction in which the first coil end 28a and the second coil end 28b are pushed is as described above is as follows. As shown in Figure 5, the length of the engagement groove 58 in the rotational direction (circumferential direction) of the bending jig 46 is slightly longer than the front-to-back width of the coil end 28. This is to allow the coil end 28 to be inserted into the bending jig 46 without providing any other mechanism. Because the dimensional relationship between the engagement groove 58 and the coil end 28 is as described above, the coil end 28 is not guided in the direction of rotation (circumferential direction) when the bending jig 46 rotates, but is pushed tangentially by the rear surface 58a of the engagement groove 58 in the direction of travel of the bending jig 46.

[0043] Figure 9C shows an image of the actual behavior of the first coil end 28a and the second coil end 28b when there is a time difference T. In this case as well, the direction in which the first jig G1 pushes the first coil end 28a is tangential, and the direction in which the second jig G2 pushes the second coil end 28b is tangential. However, when there is a time difference T, the distance traveled relative to the starting position of the second coil end 28b when the first coil end 28a and the second coil end 28b first pass each other is smaller than when there is no time difference T (Figure 9B). Therefore, the relative distance between the first coil end 28a and the second coil end 28b when they first pass each other becomes even smaller. Therefore, if the time difference T is too large, the covering portion 15 of the first coil end 28a and the covering portion 15 of the second coil end 28b rub against each other strongly when the first coil end 28a and the second coil end 28b first pass each other. This friction can cause peeling of the coating portion 15. Hereafter, peeling that can occur by this mechanism will also be referred to as "Type 2 peeling." In Type 2 peeling, peeling is particularly likely to occur at the front side of the tip of the coating portion 15 of each coil end 28 (the peeling boundary portion 19 shown in Figure 4) in the direction of movement of the coil end 28.

[0044] Therefore, in this embodiment, the time difference T is set to a time difference that can prevent peeling of the coating portions 15 of the multiple first coil ends 28a and the multiple second coil ends 28b when the multiple first coil ends 28a and the multiple second coil ends 28b first pass each other. By limiting the time difference T in this way, the second type of peeling can be suppressed. Although it varies depending on the conditions, the time difference T for preventing the second type of peeling is, for example, 0.3 seconds or less.

[0045] Preferably, the rotation angle θ of the second coil end row 28R2 in the circumferential direction, relative to the starting position of the second operation when the multiple first coil ends 28a and multiple second coil ends 28b first pass each other, is 2.0° or more. By having a rotation angle θ of 2.0° or more, it is possible to avoid the radial relative distance between the first coil ends 28a and the second coil ends 28b becoming too small when the first coil ends 28a and the second coil ends 28b first pass each other. This makes it possible to suppress the second type of delamination more effectively.

[0046] In the above-described embodiment, an example was given in which the second operation is started with a predetermined time difference T after the start of the first operation, but the present invention is not limited to this. For example, the following modified example 1 or modified example 2 may be adopted as an embodiment in which the first operation and the second operation are started simultaneously.

[0047] In Modification 1, the control unit 70 starts the first operation and the second operation simultaneously. In Modification 1, the control unit 70 reduces the movement speed of the second coil end row 28R2 after the first coil end 28a and the second coil end 28b pass each other for the first time, but before the first coil end 28a and the second coil end 28b pass each other for the last time. This makes it possible to suppress both the first type of peeling and the second type of peeling. That is, strong contact between the bulging portions 80 of the coil ends 28 when the first coil end 28a and the second coil end 28b pass each other for the last time is avoided, so the first type of peeling can be suppressed. Also, since the first operation and the second operation are started simultaneously, the second type of peeling can also be suppressed.

[0048] In the second modified example, the control unit 70 starts the first and second operations simultaneously. In the second modified example, the control unit 70 moves the second coil end row 28R2 at a slower speed than the moving speed of the first coil end row 28R1 so as to avoid strong contact between the bulging portions 80 when the first coil end 28a and the second coil end 28b pass each other at the end. This prevents strong contact between the bulging portions 80 of the coil ends 28 when the first coil end 28a and the second coil end 28b pass each other at the end, thereby suppressing the first type of delamination. In this case, in order to suppress the second type of delamination, the difference between the moving speed of the first coil end row 28R1 and the moving speed of the second coil end row 28R2 is set so that the radial relative distance between the first coil end 28a and the second coil end 28b when they first pass each other does not become too small.

[0049] The following additional information is disclosed regarding the above embodiment.

[0050] (Note 1) The segment coil (10) bending method of the present disclosure is a segment coil bending method in which a plurality of coil ends (28) protruding from the stator core in the axial direction of the stator core of a plurality of segment coils inserted into the stator core (24) of a rotating electric machine are twisted and bent in the circumferential direction of the stator core, and includes a first operation of twisting and bending a first coil end row (28R1) consisting of a plurality of first coil ends (28a) arranged in the circumferential direction in one direction of the circumferential direction, and a second operation in parallel with the first operation of twisting and bending a second coil end row (28R2) consisting of a plurality of second coil ends (28b) arranged in the circumferential direction and adjacent to the first coil end row in the radial direction of the stator core in the other direction of the circumferential direction, wherein the timing at which the first coil end row reaches the completed position by the first operation and the timing at which the second coil end row reaches the completed position by the second operation are different, wherein the timing at which the second coil end row reaches the completed position by the second operation are different.

[0051] (Note 2) In the segment coil bending method described in Note 1, the second operation may be started after a predetermined time difference (T) from the start of the first operation.

[0052] (Note 3) In the segment coil bending method described in Note 2, the second coil end row is arranged radially outward from the stator core than the first coil end row, and during the progress of the first and second operations, the plurality of first coil ends and the plurality of second coil ends pass each other in sequence, and the time difference may be a time difference that prevents peeling of the coating portions (15) of the plurality of first coil ends and the plurality of second coil ends when the plurality of first coil ends and the plurality of second coil ends first pass each other.

[0053] (Note 4) In the segment coil bending method described in Note 3, the rotation angle (θ) of the second coil end row in the circumferential direction with respect to the starting position of the second operation when the plurality of first coil ends and the plurality of second coil ends first pass each other may be 2.0° or more.

[0054] (Note 5) The segment coil bending apparatus (30) of the present disclosure performs a first operation in which a first coil end row consisting of a plurality of first coil ends arranged in the circumferential direction of the stator core, of which a plurality of coil ends of a plurality of segment coils inserted into the stator core of a rotating electric machine protrude from the stator core in the axial direction of the stator core, is twisted and bent in a first direction which is one of the circumferential directions, and in parallel with the first operation, a second coil end row consisting of a plurality of second coil ends arranged in the circumferential direction, of which a plurality of coil ends are adjacent to the first coil end row in the radial direction of the stator core, is twisted and bent in a second direction which is the other of the circumferential directions. A segment coil bending apparatus that performs a second operation, comprising: a first jig (G1) that engages with the first coil end row; a second jig (G2) that engages with the second coil end row; a first drive unit (D1) that rotates the first jig in a first direction to perform the first operation; a second drive unit (D2) that rotates the second jig in a second direction to perform the second operation; and a control unit (70) that controls the first drive unit and the second drive unit, wherein the control unit causes the timing at which the first coil end row reaches the completed movement position by the first operation to be different from the timing at which the second coil end row reaches the completed movement position by the second operation.

[0055] (Note 6) In the segment coil bending apparatus described in Note 5, the control unit may start the second operation after a predetermined time difference from the start of the first operation.

[0056] (Note 7) In the segment coil bending apparatus described in Note 6, during the progress of the first and second operations, the plurality of first coil ends and the plurality of second coil ends pass each other in sequence, the row of second coil ends is arranged radially outward from the stator core than the row of first coil ends, and the time difference may be a time difference that prevents peeling of the coatings of the plurality of first coil ends and the plurality of second coil ends when the plurality of first coil ends and the plurality of second coil ends first pass each other.

[0057] (Note 8) In the segment coil bending apparatus described in Note 7, the time difference may be set such that the rotation angle of the second coil end row in the circumferential direction, with respect to the starting position of the second operation when the plurality of first coil ends and the plurality of second coil ends first pass each other, is 2.0° or more.

[0058] While this disclosure has been described in detail, it is not limited to the individual embodiments described above. These embodiments can be added, replaced, modified, partially deleted, etc., in any way that does not depart from the gist of this disclosure or from the intent of this disclosure derived from the claims and their equivalents. These embodiments can also be implemented in combination. For example, the order of operations and processes in the embodiments described above are given as examples only and are not limited thereto. The same applies when numerical values ​​or mathematical formulas are used in the description of the embodiments described above. [Explanation of Symbols]

[0059] 10...Segment coil 24...Stator core 28... Coil end 28a... First coil end 28b...Second coil end 28R...Coil end row 28R1…First coil end row 28R2…Second coil end row 30...Bending machine 70...Control unit G1...First jig G2...Second jig

Claims

1. A method for bending segment coils, wherein the coil ends of a plurality of segment coils inserted into the stator core of a rotating electric machine are twisted and bent in the circumferential direction of the stator core, A first operation involves twisting and bending a first coil end row, which consists of multiple first coil ends arranged in the circumferential direction, in one direction within the circumferential direction, The first operation is performed in parallel with the first operation, and includes a second operation in which a plurality of second coil ends, which are arranged in the circumferential direction and consist of a plurality of second coil ends adjacent to the first coil end row in the radial direction of the stator core, are twisted and bent in a direction other than the circumferential direction, A method for bending a segment coil, wherein the second operation is started after the first operation has begun but before the first operation has ended, and the timing at which the first coil end row reaches the completed position by the first operation is different from the timing at which the second coil end row reaches the completed position by the second operation.

2. In the method for bending a segment coil according to claim 1, A method for bending a segment coil, wherein the second operation is started after a predetermined time difference from the start of the first operation.

3. In the method for bending a segment coil according to claim 2, The second coil end row is positioned radially outward from the stator core than the first coil end row. During the progress of the first and second operations, the multiple first coil ends and the multiple second coil ends pass each other in sequence. A method for bending a segment coil, wherein the time difference is such that when the plurality of first coil ends and the plurality of second coil ends first pass each other, peeling of the coatings of the plurality of first coil ends and the plurality of second coil ends can be prevented.

4. In the method for bending a segment coil according to claim 3, A method for bending a segment coil, wherein the rotation angle of the second coil end row in the circumferential direction, with respect to the starting position of the second operation when the plurality of first coil ends and the plurality of second coil ends first pass each other, is 2.0° or more.

5. A segment coil bending apparatus that performs a first operation to twist and bend a first coil end row, consisting of a plurality of first coil ends arranged in the circumferential direction of the stator core, from among a plurality of coil ends that protrude from the stator core of a plurality of segment coils inserted into the stator core of a rotating electric machine, in a first direction which is one of the circumferential directions, and in parallel with the first operation to twist and bend a second coil end row, consisting of a plurality of second coil ends arranged in the circumferential direction, from among the plurality of coil ends, in a second direction which is the other of the circumferential directions, wherein the second coil end row consists of a plurality of second coil ends arranged in the circumferential direction and is adjacent to the first coil end row in the radial direction of the stator core, A first jig that engages with the first coil end row, A second jig that engages with the second coil end row, A first drive unit that rotates the first jig in the first direction to perform the first operation, A second drive unit rotates the second jig in the second direction to perform the second operation, The system comprises a control unit that controls the first drive unit and the second drive unit, The control unit starts the second operation after the start of the first operation but before the end of the first operation, and makes the timing at which the first coil end row reaches the completed position by the first operation and the timing at which the second coil end row reaches the completed position by the second operation different, in a segment coil bending apparatus.

6. In the segment coil bending apparatus according to claim 5, The control unit is a segment coil bending apparatus that starts the second operation after a predetermined time difference from the start of the first operation.

7. In the segment coil bending apparatus according to claim 6, During the progress of the first and second operations, the multiple first coil ends and the multiple second coil ends pass each other in sequence. The second coil end row is positioned radially outward from the stator core than the first coil end row. The aforementioned time difference is such that when the plurality of first coil ends and the plurality of second coil ends first pass each other, peeling of the coatings of the plurality of first coil ends and the plurality of second coil ends can be prevented, in a segment coil bending apparatus.

8. In the segment coil bending apparatus according to claim 7, The aforementioned time difference is set such that the rotation angle of the second coil end row in the circumferential direction, relative to the starting position of the second operation when the plurality of first coil ends and the plurality of second coil ends first pass each other, is 2.0° or more, in a segment coil bending apparatus.

Images