Stator manufacturing method and restraint jig

Abstract

Provided is a stator manufacturing method capable of suppressing twisting of a protrusion part associated with bending a segment coil in the circumferential direction. A restraint jig 19 is positioned between axial base parts 11a of protrusion parts 11 adjacent to each other in the circumferential direction. The restraint jig 19 has a groove 25 corresponding to each of the base parts 11a adjacent in the circumferential direction. A coil end 9a that is the tip of the protrusion parts 11 is relatively displaced in the circumferential direction with respect to a stator core 3, the base part 11a of the projection parts 11 is inserted into the groove 25 of each of the adjacent restraint jigs 19, and the projection parts 11 are bent while being restrained from the radial direction of the stator core 3.

Description

Stator manufacturing method and restraining jig

[0001] The present invention relates to a method for manufacturing a stator for a rotating electrical machine such as a motor or a generator, and a restraining jig used therefor.

[0002] Conventional methods for manufacturing stators include, for example, as disclosed in Patent Document 1, in which multiple segment coils are held in a stator core and the protruding portions of the segment coils that protrude axially from the stator core are bent circumferentially.

[0003] In this manufacturing method, a rod-shaped restricting member is positioned between adjacent protrusions in the circumferential direction, and the protrusions are bent along the restricting member, thereby controlling or restricting the degree of bending of the protrusions.

[0004] However, in the above-described conventional manufacturing method, twisting may occur in the protruding portion of the segment coil as a result of bending it in the circumferential direction.

[0005] Japanese Patent Application Laid-Open No. 2015-2632

[0006] The problem to be solved is that twisting occurs in the protruding parts of the segment coils when they are bent in the circumferential direction.

[0007] The present invention provides a method for manufacturing a stator in which protruding portions of segment coils protruding axially from a stator core that holds the segment coils are bent circumferentially. This manufacturing method involves positioning a restraining jig between the axial bases of the protruding portions adjacent in the circumferential direction. The restraining jig has grooves that correspond to the adjacent bases in the circumferential direction. The tips of the protruding portions are then displaced circumferentially relative to the stator core, and the bases of the protruding portions are inserted into the grooves of the adjacent restraining jigs to bend the protruding portions while restraining them from the radial direction of the stator core.

[0008] The present invention also provides a restraining jig used when bending, in the circumferential direction, protruding portions of segment coils that protrude axially from a stator core that holds the segment coils. The restraining jig has a jig body positioned between the axial bases of the protruding portions adjacent in the circumferential direction, and grooves provided in the jig body that correspond to the adjacent bases in the circumferential direction when the jig body is positioned between the bases. When the protruding portions are bent, the bases of the protruding portions are inserted into the adjacent grooves, thereby restraining them from the radial direction of the stator core.

[0009] According to the present invention, twisting that occurs when the protruding portion of the segment coil is bent in the circumferential direction can be suppressed.

[0010] FIG. 1 is a perspective view of a stator supported by a support jig according to an embodiment of the present invention. FIG. 2 is an enlarged perspective view of a portion of FIG. 1. FIG. 3 is a perspective view of the stator supported by the support jig, showing the protruding portions of the segment coils before bending. FIG. 4 is an enlarged perspective view of a portion of FIG. 3. FIGS. 5(A) to 5(F) are cross-sectional views showing a method for manufacturing a stator. FIG. 6(A) is a cross-sectional view showing a twisting device and a restraining jig according to an embodiment of the present invention, and FIG. 6(B) is an enlarged view of a portion of FIG. 6(A). FIG. 7 is a perspective view of a stator core and a restraining jig. FIG. 8 is an enlarged perspective view of a portion of FIG. 7. FIG. 9 is a perspective view of the restraining jig of FIG. 7. FIG. 10 is an exploded perspective view of the restraining jig of FIG. 9. FIG. 11 is a plan view of the restraining jig of FIG. 9. FIG. 12 is a front view of the restraining jig of FIG. 9 as seen from the radial direction. FIG. 13 is a perspective view showing the twisting process. FIG. 14 is an enlarged cross-sectional view of the periphery of the groove of FIG. 13.

[0011] The objective of suppressing twisting that occurs when the protruding portions of the segment coils are bent in the circumferential direction is achieved by using a restraining jig that allows bending while restraining the protruding portions from the radial direction.

[0012] The manufacturing method of the stator 1 is to manufacture the stator 1 in which the protruding portions 11 of the segment coils 9 that protrude in the axial direction from the stator core 3 that holds the segment coils 9 are bent in the circumferential direction.

[0013] In this manufacturing method, a restraining jig 19 is positioned between the bases 11a in the axial direction of circumferentially adjacent protrusions 11 before bending. The restraining jig 19 has grooves 25 corresponding to the bases 11a adjacent in the circumferential direction.

[0014] Then, the tip 9a of the protrusion 11 is displaced circumferentially relative to the stator core 3, and the base 11a of the protrusion 11 is inserted into the groove 25 of the adjacent restraining jig 19 to restrain the protrusion 11 from the radial direction of the stator core 3 while bending the protrusion 11.

[0015] The restraining jig 19 does not need to be removed if it is made of an insulating material such as resin, but if it is to be removed, it is preferable to use a spacer 23 .

[0016] When the spacer 23 is used, the restraining jig 19 has the jig body 21 having the groove 25 stacked on the spacer 23 that is movable in the radial direction. The spacer 23 is removed radially outward after the protrusion 11 is bent. The jig body 21 is moved axially toward the stator core 3 in the space S created by removing the spacer 23, and then the base 11a of the protrusion 11 is pulled out from the groove 25 and removed radially outward.

[0017] The restraining jig 19 can have various configurations, but in one embodiment, it has a jig body 21 and a groove 25 .

[0018] The jig body 21 is positioned between the base portions 11a of the circumferentially adjacent protrusions 11 in the axial direction. The groove 25 is provided in the jig body 21.

[0019] The restraining jig 19 may include the spacer 23 as described above.

[0020] The grooves 25 may be provided on both circumferential sides of the jig body 21. In this case, the grooves 25 on one circumferential side may be shifted radially relative to the grooves 25 on the other circumferential side.

[0021] The jig body 21 may have any planar shape, but may have a sector shape in plan view. In this case, it is preferable that the outer peripheries 21a of the jig bodies 21 abut against each other in the circumferential direction.

[0022] [Stator] Fig. 1 is a perspective view of a stator supported by a support jig according to an embodiment of the present invention, and Fig. 2 is an enlarged perspective view showing a part of Fig. 1.

[0023] 1 constitutes a rotating electric machine together with a rotor (not shown). The rotating electric machine is constituted as a three-phase (U-phase, V-phase, W-phase) eight-pole AC permanent magnet synchronous motor that drives the drive wheels of an electric vehicle (not shown) and generates electricity using regenerative braking force from the drive wheels.

[0024] 1 shows a state in which the stator coil 5 is assembled into the stator core 3 and supported by a support jig 7. In the state shown in FIG. 1, the protruding portion 11 including the coil end 9a of each segment coil 9 is bent.

[0025] In this state, the coil ends 9a are joined by welding to form the stator coil 5. After that, the coil ends 9a are coated with an insulating paint, and the stator coil 5 portion is sealed with resin to form the stator 1 for the rotating electric machine. For convenience, the following description will be made as if it were the stator 1 shown in FIG.

[0026] The stator 1 includes a stator core 3 and a stator coil 5. The stator core 3 is formed, for example, by laminating multiple annular electromagnetic steel plates. Three phases of the stator coil 5 are provided on the stator core 3 and are configured to have a wave-wound shape. The stator coil 5 is made up of multiple segment coils 9.

[0027] The stator core 3 has a plurality of slots 3a arranged at equal intervals in the circumferential direction (the direction of rotation of the rotating electrical machine). Segment coils 9 are inserted into the slots 3a with insulating paper 13 interposed therebetween. This holds the plurality of segment coils 9 in place in the stator core 3.

[0028] Each of the multiple segment coils 9 is formed in a U-shape, e.g., a hairpin shape, and is assembled circumferentially around the stator core 3. The segment coils 9 are arranged circumferentially, with the apex of the hairpin shifted to the adjacent layer. Note that the apex of the hairpin is hidden by the support jig 7 on the underside of Figure 1 and is therefore not shown.

[0029] 1 and 2 , the segment coil 9 is made of, for example, a rectangular wire with a rectangular cross section. However, the cross-sectional shape of the segment coil 9 is not particularly limited. This segment coil 9 has a protrusion 11 including a coil end 9a without an insulating layer that protrudes in the axial direction from the stator core 3. The axial direction refers to the direction along the axis of the stator core 3.

[0030] The insulating layer is formed on the entire portion of the segment coil 9 except for the coil end 9a. In this embodiment, the protruding portion 11 includes a portion that is inclined with respect to the axial direction. Therefore, the protrusion here means that the coil end 9a, which is the tip of the protruding portion 11, and the base portion 11a are misaligned in the axial direction.

[0031] The base 11a is a region of the protruding portion 11 that is adjacent in the circumferential direction to the restraining jig 19 described later. The protruding portion 11 is twisted and bent in the circumferential direction. Therefore, the protruding portion 11 is the tip region of the hairpin-shaped leg of the segment coil 9 where bending is performed.

[0032] Sets of coil ends 9a between adjacent layers are joined by welding with the front of one coil end 9a facing the back of the other coil end 9a in the radial direction. Multiple sets of joined coil ends 9a are arranged in the circumferential and radial directions of the stator core 3. The circumferential and radial directions refer to the directions along the outer periphery and diameter of the stator core 3, respectively.

[0033] [Twisting of the stator] Figure 3 is a perspective view of a stator supported by a support jig, showing the protruding portions of the segment coils before bending. Figure 4 is an enlarged perspective view showing a portion of the stator core of Figure 3. Figures 5(A) to 5(F) are cross-sectional views showing a method for manufacturing a stator. Figure 6(A) is a cross-sectional view showing a twisting device and a restraining jig, and Figure 6(B) is an enlarged view of a portion of Figure 6(A).

[0034] In the manufacturing method of the stator 1 of this embodiment, the protruding portions 11 of the segment coils 9 held in the stator core 3 as shown in Figures 3 and 4 are bent in the circumferential direction by twisting as shown in Figures 1 and 2. The bent protruding portions 11 are joined to the coil ends 9a that will form a set in a subsequent process.

[0035] In this embodiment, the protrusion 11 to be bent is made up of 14 layers, from the outermost layer to the innermost layer, as shown in Figures 5(A) to 5(F). Figures 1 to 4 show the protrusion 11 as having six layers, and show the same configuration as Figure 5(A) except for the number of layers. In the manufacturing method of this embodiment, the protrusion 11 will be described as having 14 layers, as shown in Figure 5, while also referring to Figures 1 to 4, which show the six layers.

[0036] The bending of the protrusions 11 is performed in each layer by moving the protrusions 11 in the circumferential direction relative to the stator core 3 while restraining the coil ends 9 a of the protrusions 11 along the axial direction.

[0037] The coil end 9a is restrained and moved in the circumferential direction by, for example, annular twisting jigs 15a and 15b shown in Fig. 6. The twisting jigs 15a and 15b may be provided with a plurality of teeth 17 in the circumferential direction.

[0038] In this case, the twisting jigs 15a and 15b descend to circumferentially restrain the coil end 9a, which is the tip of the protrusion 11, between adjacent teeth 17. This circumferential restraint is achieved by axially inserting the coil end 9a between adjacent teeth 17 (left side of FIG. 6A). In this state, the twisting jigs 15a and 15b are displaced circumferentially relative to the stator core 3 to bend the protrusion 11. Note that various types of twisting jigs 15a and 15b can be used as long as they can restrain the coil end 9a of the protrusion 11 and move it circumferentially.

[0039] The bending of the protrusions 11 of the first layer, which is the outermost periphery, and the protrusions 11 of the next second layer are performed simultaneously by rotating a pair of twisting jigs 15a and 15b in opposite circumferential directions. After bending, the twisting jigs 15a and 15b are raised ((right side of FIG. 6(A))). Similarly, the bending of the protrusions 11 of the first to fourteenth layers, two at a time, is performed simultaneously, such as the third and fourth layers, the fifth and sixth layers, etc. However, the bending of the protrusions 11 may be performed individually for each layer.

[0040] When bending the protruding portion 11, in this embodiment, a restraining jig 19 is used to prevent the protruding portion 11 from twisting, as shown in FIGS.

[0041] First, as shown in Figure 5(A), the segment coils 9 are held in the stator core 3. In this state, as shown in Figures 3 and 4, the protrusions 11 protrude from the stator core 3 in the axial direction and are supported on the support jig 7. In the state shown in Figures 3 to 5(A), radial gaps are formed between the protrusions 11 of adjacent layers. These gaps make it easier to bend the protrusions in the circumferential direction.

[0042] Next, as shown in Fig. 5(B), a restraining jig 19 is positioned between the bases 11a in the axial direction of the protrusions 11 that are adjacent in the circumferential direction of the stator core 3. Fig. 5(B) shows a state in which the restraining jig 19 is positioned between the protrusion 11 on the front side (not shown) and the protrusion 11 on the back side (shown). In Fig. 5(B), the restraining jig 19 is positioned between the bases 11a in the radial direction, but the insertion direction is free, and it can also be positioned in the axial direction, for example.

[0043] Fig. 7 is a perspective view showing the stator core 3 and the restraining jig 19. Fig. 8 is an enlarged perspective view showing a part of Fig. 7. Figs. 9 to 12 are a perspective view, an exploded perspective view, a plan view, and a front view seen from the radial direction showing the restraining jig 19 of Fig. 7.

[0044] 7 to 12, the restraining jig 19 of this embodiment includes a jig body 21 and a spacer 23. For convenience, the protrusion 11 is not shown in FIGS.

[0045] The jig body 21 has a sector shape in a plan view, and corresponds to the shape between the circumferentially adjacent protrusions 11 or their base portions 11a. The planar shape of the jig body 21 can be set arbitrarily.

[0046] The outer periphery 21a of the jig body 21 is located between the bases 11a of adjacent protrusions 11 and is located radially outward of the layer of the first outermost protrusion 11. This outer periphery 21a extends to one side in the circumferential direction and abuts against the outer periphery 21a of the adjacent jig body 21. Therefore, the jig body 21 is configured so that the outer peripheries 21a abut against each other in the circumferential direction. This abutment positions the jig body 21 in the circumferential direction.

[0047] Grooves 25 are provided in the jig body 21. The grooves 25 are provided as grooves corresponding to the bases 11a that are adjacent in the circumferential direction when the restraining jig 19 is positioned between the bases 11a of the protrusions 11 that are adjacent in the circumferential direction. The grooves 25 are arranged along the circumferential direction relative to the bases 11a of the protrusions 11 that are adjacent in the circumferential direction. The grooves 25 can be formed as approximately linear grooves in the circumferential direction, arc-shaped grooves that extend along the circumferential direction, or the like.

[0048] The grooves 25 located on one circumferential side and the grooves 25 located on the other circumferential side are arranged offset in the radial direction and correspond to the bases 11a of the protrusions 11 located on one and the other circumferential sides, respectively. The groove 25 on one circumferential side is provided from an edge on one circumferential side to the center of the jig body 21. The groove 25 on the other circumferential side is provided from an edge on the other circumferential side to the center of the jig body 21.

[0049] Each groove 25 is defined by a radial wall 25a. The wall 25a extends approximately linearly in the circumferential direction in a plan view, but may have other planar shapes, such as a cylindrical shape. The spacing between the wall 25a (the radial dimension of the groove 25) corresponds to the radial dimension of the protrusion 11 of the segment coil 9 before bending. Specifically, the radial dimension of the groove 25 is set to be the same as or slightly larger than the radial dimension of the protrusion 11 of the segment coil 9.

[0050] The bottom surface 25b of each groove 25 is inclined axially toward the outside in the circumferential direction so as to gradually approach the stator core 3. The outside in the circumferential direction corresponds to one edge side of the groove 25 on one circumferential side, and corresponds to the other edge side of the groove 25 on the other circumferential side.

[0051] The spacer 23 stacks the jig bodies 21 and is movable in the radial direction. The spacer 23 in this embodiment is plate-shaped and has the same contour as the jig body 21 in plan view. Therefore, the spacer 23 is positioned between the jig body 21 and the stator core 3 in the axial direction and overlaps the jig body 21. Note that the shape of the spacer 23 is not important as long as it allows the jig bodies 21 to be stacked.

[0052] As shown in Figure 12, circumferential displacement between the spacer 23 and the jig body 21 is suppressed by a convex portion 27a and a concave portion 27b along the radial direction. One of the convex portion 27a and the concave portion 27b (in this embodiment, the convex portion 27a) is provided on the spacer 23, and the other (in this embodiment, the concave portion 27b) is provided on the jig body 21. The convex portion 27a and the concave portion 27b engage with each other so as to be slidable in the radial direction. The convex portion 27a may be provided over the entire radial direction, or may be provided over only a portion of the radial direction.

[0053] After the restraining jig 19 is positioned between the bases 11a of the protrusions 11 adjacent in the circumferential direction, a twisting process is performed as shown in Fig. 5(C). Fig. 5(C) shows a state in which the protrusion 11 on the front side, which was not shown in Fig. 5(B), is bent by the twisting process and engaged with the restraining jig 19. In this embodiment, in addition to the restraining jig 19, additional restraining jigs 29a to 29c are positioned at various locations as shown in Fig. 6, and the twisting process is performed.

[0054] The additional restraining jigs 29a to 29c are positioned radially inside and outside the protrusion 11, and between sets of adjacent coil ends 9a. Note that the additional restraining jigs 29a to 29c may be omitted.

[0055] The radially inner restraining jig 29a is disk-shaped and attached to a shaft 30 that axially passes through the center of the stator core 3, with its outer peripheral surface abutting radially against the protruding portion 11 of the innermost layer. The radially outer restraining jig 29b is ring-shaped and its inclined inner peripheral surface abuts radially against the protruding portion 11 of the outermost layer. The restraining jig 29c is ring-shaped and is located in the gap between a set of coil ends 9a to be bent simultaneously and an adjacent set of coil ends 9a. A ring-shaped jig holder 31 engages the outer peripheries of the restraining jigs 29b and 19.

[0056] In the restraining state by the restraining jig 19 and the additional restraining jigs 29a to 29c, the pair of twisting jigs 15a and 15b that restrain the coil end 9a of the protrusion 11 are rotated in opposite circumferential directions, thereby twisting the coil end 9a two layers at a time at the same time.

[0057] Fig. 13 is a perspective view showing the twisting process. Fig. 14 is an enlarged cross-sectional view of the periphery of the groove in Fig. 13. Fig. 13 shows the twisting process of the 14th and 13th layers on the innermost periphery.

[0058] 13 and 14 , when twisting is performed, the edge of the groove 25 of the jig body 21 of the restraining jig 19 abuts against the base 11 a of the protruding portion 11 in the circumferential direction. The abutting portion serves as a fulcrum, causing the protruding portion 11 to bend in the circumferential direction.

[0059] This bending causes the bases 11 a of the protrusions 11 to enter the grooves 25 in the circumferential direction. As a result, the coil ends 9 a, which are the tips of the protrusions 11, are displaced relative to the stator core 3 in the circumferential direction, and the bases 11 a of the protrusions 11 are fitted into the grooves 25 of the adjacent restraining jigs 19.

[0060] As a result, the base 11a of the protrusion 11 is constrained in the radial direction by the wall 25a. The constraining is achieved by engaging both radial side surfaces of the base 11a of the protrusion 11 with the wall 25a. Therefore, the base 11a of the protrusion 11 is bent, and twisting of the base 11a of the protrusion 11 around the axis due to the bending is suppressed.

[0061] Suppressing twisting of the base portion 11a suppresses twisting of the entire protruding portion 11. In this embodiment, the restraining jig 29c is further provided between the sets of coil ends 9a, so that twisting of the protruding portion 11 can be more reliably suppressed.

[0062] Furthermore, in this embodiment, since the protrusion 11 is restrained from the inside and outside in the radial direction by the restraining jigs 29a and 29b, twisting of the protrusion 11 can be more reliably suppressed.

[0063] In this way, in this embodiment, it is possible to circumferentially bend the protrusions 11 while suppressing twisting of the protrusions 11, including the base portions 11 a. After the bending of the protrusions 11 is completed, the bent protrusions 11 are engaged with the grooves 25 of the restraining jig 19.

[0064] 5(D) to 5(F), the restraining jig 19 can be removed. If the restraining jig 19 is made of an insulating material such as resin, it does not need to be removed and can form part of the stator 1. In this case, the restraining jig 19 may be formed by integrating the jig body 21 and the spacer 23.

[0065] The additional restraining jigs 29a and 29b and the jig holder 31 can be disassembled and removed, respectively. The additional restraining jig 29c can be removed by pulling it out in the axial direction.

[0066] To remove the restraining jig 19, first remove the spacer 23 radially outward, as shown in Figure 5(D). The spacer 23 can be removed by pulling it out radially. At this time, because the groove 25 of the jig body 21 is engaged with the base 11a of the bent protrusion 11, the spacer 23 can be reliably moved relative to the jig body 21 and the stator core 3 and pulled out radially outward.

[0067] When the spacer 23 is removed, a space S is secured in the axial direction between the jig body 21 and the stator core 3. Using this space S, the jig body 21 is moved in the axial direction toward the stator core 3, as shown in FIG.

[0068] This causes the base 11a of the protrusion 11 to be pulled out of the groove 25. As a result, the engagement between the jig body 21 and the protrusion 11 is released, and the jig body 21 can be removed radially outward, as shown in Fig. 5(F). This removal can be achieved by pulling it out radially, just like the spacer 23.

[0069] As described above, in the manufacturing method of the stator 1 of this embodiment, the restraining jig 19 is positioned between the bases 11a in the axial direction of circumferentially adjacent protrusions 11. The restraining jig 19 has grooves 25 corresponding to the bases 11a adjacent in the circumferential direction. Then, the coil ends 9a, which are the tips of the protrusions 11, are displaced in the circumferential direction relative to the stator core 3, and the bases 11a of the protrusions 11 are inserted into the grooves 25 of the adjacent restraining jigs 19, thereby bending the protrusions 11 while restraining them from the radial direction of the stator core 3.

[0070] This makes it possible to suppress twisting that accompanies circumferential bending of the protruding portion 11. Furthermore, the radial constraint provided by the grooves 25 also serves to position the protruding portion 11 in the radial direction, enabling reliable bending of the protruding portion 11.

[0071] The restraining jig 19 is configured by stacking a jig body 21 having a groove 25 on a spacer 23 that is movable in the radial direction. The spacer 23 is removed radially outward after the protrusion 11 is bent, and the jig body 21 is moved axially toward the stator core 3 in the space S created by removing the spacer 23, and the base 11a is extracted from the groove 25, and then removed radially outward.

[0072] Therefore, the restraining jig 19 can be easily and reliably removed from the stator 1 with the bent protrusion 11. As a result, the material of the restraining jig 19 can be set as desired. Note that the spacer 23 can also be removed radially inward depending on its planar shape, such as a rectangular plate or rod. On the other hand, if the restraining jig 19 is made of an insulating material such as resin, there is no need to remove it, making manufacturing easier.

[0073] The spacer 23 has a simple structure that stacks the jig body 21 and is movable in the radial direction, and can be easily removed.

[0074] The grooves 25 are provided on both sides in the circumferential direction of the jig body 21, and the groove 25 on one side in the circumferential direction is shifted radially relative to the groove 25 on the other side in the circumferential direction. Therefore, when the protruding portions 11 of radially adjacent layers are bent in opposite directions in the circumferential direction, the grooves 25 on both sides in the circumferential direction of the jig body 21 can suppress twisting of the protruding portions 11 of the adjacent layers.

[0075] The grooves 25 are formed so that the bottom surfaces 25b thereof are inclined toward the stator core 3 in the axial direction and become deeper toward the outside in the circumferential direction. As a result, the protrusions 11 can be held in the radial direction from the initial stage of bending, and twisting can be more reliably suppressed.

[0076] The jig body 21 has a sector shape in a plan view, and the outer peripheral portions 21 a abut against each other in the circumferential direction. Therefore, the jig body 21 can be easily installed on the cylindrical stator core 3.

[0077] REFERENCE SIGNS LIST 1 stator 3 stator core 9 segment coil 9a coil end (tip) 11 protrusion 11a base 19 restraint jig 21 jig body 21a outer periphery 23 spacer 25 groove 25b bottom surface S space

Claims

1. A method for manufacturing a stator in which a protruding portion of a segment coil protruding in the axial direction from a stator core that holds the segment coil is bent in the circumferential direction, comprising: positioning a restraining jig between bases in the axial direction of the protruding portions adjacent in the circumferential direction, the restraining jig having grooves corresponding to the bases adjacent in the circumferential direction; displacing the tips of the protruding portions in the circumferential direction relative to the stator core; and inserting the bases of the protruding portions into the grooves of the adjacent restraining jig to bend the protruding portions while restraining them from the radial direction of the stator core.

2. A method for manufacturing a stator as claimed in claim 1, wherein the restraining jig is constructed by stacking a jig body having the groove on a spacer which is movable in the radial direction, the spacer is removed radially outward after bending the protruding portion, and the jig body is moved in the axial direction towards the stator core in the space created by removing the spacer to extract the base from the groove and then removed radially outward.

3. A restraining jig used when bending circumferentially a protruding portion of a segment coil that protrudes axially from a stator core that holds the segment coil, the restraining jig having a jig body positioned between bases in the axial direction of the protruding portions adjacent in the circumferential direction, and grooves provided in the jig body that correspond to the bases adjacent in the circumferential direction when the jig body is positioned between the bases, and when the protruding portions are bent, the bases of the protruding portions are inserted into the adjacent grooves to restrain them from the radial direction of the stator core.

4. A restraining jig as claimed in claim 3, comprising a spacer for stacking said jig bodies and movable in said radial direction.

5. A restraining jig as claimed in claim 3 or 4, wherein the grooves are provided on both sides of the jig body in the circumferential direction, and the groove on one side in the circumferential direction is offset in the radial direction relative to the groove on the other side in the circumferential direction.

6. A restraining jig as claimed in claim 5, wherein the bottom surface of said groove is inclined so as to gradually approach the stator core side in the axial direction toward the outside in the circumferential direction.

7. A restraining jig as claimed in claim 3 or 4, wherein the jig body is fan-shaped in a plan view, and the outer peripheries abut against each other in the circumferential direction.