JP2023037860A - Forming device and forming method for stator coil - Google Patents

Abstract

To keep coil ends after bending arranged low, while inserting securely tip parts of projections of segment coils into groove parts of a bending jig when bending segment coils accommodated in a slot of a stator core.SOLUTION: A forming device 10 for a stator coil comprises: a cylindrical bending jig 12 that has groove parts 14 into which tip parts 3 of projections 2 of segment coils 1 protruding toward one side in an axial direction of a stator core 11 can be inserted; and a drive part for axially rotating the bending jig 12 while moving it in the axial direction. The projections 2 of the segment coils 1 are arranged in a plurality of rows each formed in a radial direction of the stator core 11. The forming device 10 further comprises an aligning device 16 that can align the tip parts 3 of the plurality of projections 2 forming respective rows, by aligning circumferential direction positions of the tip parts.SELECTED DRAWING: Figure 1

Description

The present invention relates to a stator coil molding apparatus and molding method.

2. Description of the Related Art In recent years, in view of environmental problems, there has been an increasing trend to adopt motors in driving devices and peripheral devices of vehicles such as electric vehicles and hybrid vehicles. The motor mounted on the vehicle is required to have a high output in order to improve the driving performance of the vehicle, and is also required to be small due to the space available for installation.

Here, for the stator coil of the motor, a plurality of segment coils accommodated in the slots of the stator core are bent so that the protruding portions protruding from the stator core of the coil are twisted in the circumferential direction. After that, the tip portions of the projecting portions of the in-phase segment coils are joined together by welding or the like.

For example, Patent Literature 1 discloses an example of a configuration for bending projecting portions of a plurality of segment coils. That is, in Patent Document 1, a holding device formed in a cylindrical shape and holding tip portions of a plurality of protrusions, and a driving portion for relatively moving the holding device with respect to a stator core are provided, and the holding device includes a plurality of A plurality of grooves are provided in the circumferential direction into which each of the tip end portions of the driving portion can be inserted, and the driving portion can rotate in the circumferential direction with respect to the stator core while moving the holding device in a direction to approach the stator core in the axial direction. An apparatus for manufacturing a stator coil is disclosed. Further, in a state in which the tip portion is inserted into the groove portion of the holding device, the holding device is axially moved toward the stator core by the driving section and rotated in the circumferential direction, so that the plurality of protrusions are twisted in an S-shape. It is disclosed to produce bending deformation.

Japanese Patent Application Laid-Open No. 2020-36469

In order to reduce the size of the motor described above, it is important to minimize the coil end, which is the dimension in the height direction of the projecting portion of the segment coil, in the stator coil forming process. Here, as described in Patent Literature 1, when bending the projecting portion of the segment coil with twisting, the curvature of the bent portion formed in the segment coil (reciprocal of the radius of curvature), especially the bending jig The curvature of the bent portion on the side of the holding device, which is the result, is greatly influenced by the curvature of the opening side edge of the groove provided in the holding device. That is, as shown in FIG. 7A, the larger the radius of curvature of the opening side edge 15 of the groove 14, the easier it is to insert the tip 3 of the one-segment coil into the groove 14. The height direction position (coil end) H of the portion 3 becomes higher. Conversely, as shown in FIG. 7B, the smaller the curvature radius of the opening-side edge portion 15 of the groove portion 14, the lower the position H in the height direction of the tip portion 3 after the bending process is completed. The ability (guiding function) of the tip portion 3 to be drawn into the groove portion 14 by the opening side edge portion 15 is deteriorated. Therefore, as shown in FIG. 8, when the segment coils 1 are accommodated in the slots of the stator core 11, the circumferential positions of the distal end portions 3 of the plurality of projections 2 arranged in a row in the radial direction of the stator core 11 vary. There is a concern that the tip 3 may not be inserted into the groove 14 of the holding device (bending jig) 12 and the tip 3 may be crushed by the holding device 12 (see FIG. 9).

In view of the above circumstances, in the present specification, when bending the segment coil accommodated in the slot of the stator core, the distal end of the projecting portion of the segment coil must be securely inserted into the groove of the bending jig. However, the technical problem to be solved is to keep the coil end after bending low.

The above problems are solved by a stator coil forming apparatus according to the present invention. That is, this forming device is a device for forming a stator coil by bending, accompanied by twisting, a segment coil accommodated in a slot of a stator core. A stator coil comprising: a bending jig having a groove into which the distal end of the projecting portion of the projecting segment coil can be inserted; and a driving section for axially rotating the bending jig while moving it in the axial direction In the forming apparatus, the projections of the segment coils are arranged in a plurality of rows in the radial direction of the stator core. It is characterized in that it further comprises an alignment device.

As described above, in the stator coil forming apparatus according to the present invention, attention is focused on the fact that a plurality of segment coils are arranged in rows in the radial direction of the stator core. An aligning device capable of aligning the circumferential positions of the tip portions is further provided. With this configuration, the circumferential positions of the distal end portions of the plurality of segment coils forming each row can be aligned without omission. It is possible to reliably insert the tip into the groove. Therefore, by reducing the radius of curvature of the edge of the groove on the opening side, it is possible to keep the height of the coil end low after bending while avoiding crushing of the tip.

Further, in the stator coil forming apparatus according to the present invention, the aligning device includes an aligning jig having a pair of regulating surfaces facing each other in the circumferential direction of the stator core and capable of regulating the circumferential position of the distal end portion, and an aligning jig. can be moved along the radial direction of the stator core. Further, in this case, the alignment jig moves the tip of the outermost projection of the row of projections to a radial position where alignment is possible, and the tip of the innermost projection It may be configured to be movable to a radial position where it can be retracted to the inner diameter side of the portion.

Stator cores of this type often have a cavity in the center that can accommodate a portion of the rotor. Therefore, by configuring the aligning device as described above, the aligning device can be arranged without requiring a new installation space. Therefore, it is possible to achieve stable bending and a low coil end while avoiding an increase in size of the forming apparatus as a whole.

Moreover, the solution of the above problems can also be achieved by a stator coil forming method according to the present invention. That is, this forming method is a method for forming a stator coil by subjecting a plurality of segment coils accommodated in a plurality of slots formed in openings in a stator core to a bending process accompanied by twisting. an inserting step of inserting at least the tip end portion of the projecting portion of the segment coil projecting on one side in the axial direction of the stator core into a plurality of groove portions provided in the bending jig; A method for forming a stator coil comprising a bending step of bending the projecting portion by axially rotating a bending jig while moving it in the axial direction, wherein the distal end portion of the segment coil is equal to the diameter of the stator core. The tips are arranged in a plurality of rows in a direction, and an alignment step is further provided before the insertion step to align and align the circumferential positions of the plurality of distal ends forming each row using an alignment device. characterized by

As described above, in the stator coil forming method according to the present invention as well, the segment coils arranged in a plurality of rows in the radial direction of the stator core are arranged in a plurality of rows, and the plurality of tip ends forming each row are formed. Since an aligning device capable of aligning the circumferential positions of the segments is further provided, it is possible to align the circumferential positions of the distal end portions of the plurality of segment coils forming each row without omission. The tip can be reliably inserted into the groove regardless of the shape of the opening side edge of the groove. Therefore, by reducing the radius of curvature of the edge of the groove on the opening side, it is possible to keep the height of the coil end low after bending while avoiding crushing of the tip.

As described above, according to the present invention, when bending the segment coil accommodated in the slot of the stator core, the distal end of the projecting portion of the segment coil is reliably inserted into the groove of the bending jig. At the same time, the coil end after bending can be kept low.

1 is a plan view of a main part of a stator coil forming apparatus according to an embodiment of the present invention; FIG. 2 is a flow chart showing an example of a method of forming a stator coil using the forming apparatus shown in FIG. 1; FIG. 2 is an enlarged perspective view of a main part showing an alignment state of tip portions of segment coils in the state shown in FIG. 1; FIG. 2 is a plan view of the essential parts of the molding apparatus shown in FIG. 1 , and is a plan view of the essential parts showing a state in which the circumferential positions of the tips of a plurality of protrusions arranged in a row are aligned by an aligning device; FIG. 5 is an enlarged perspective view of a main part showing the aligned state of the distal end portions of the segment coils in the state shown in FIG. 4; FIG. 4 is an enlarged side view of a main part showing movements of a bending jig and an aligning jig after an aligning process; FIG. 10 is a diagram showing the influence of the curvature of the opening-side edge of the groove formed in the bending jig on the coil end when forming by a conventional forming technique. FIG. 10 is an enlarged plan view of a main part showing an alignment state of the tips of protrusions of a plurality of segment coils forming a row; FIG. 5 is an enlarged side view of a main part showing a problem that may occur when the opening side edge of the groove formed in the bending jig has a large clearance.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A stator coil molding apparatus and molding method according to an embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 6, the forming apparatus 10 according to the present embodiment drives a stator core 11, a bending jig 12, and a bending jig 12. Here, the shaft is rotated while being moved in the axial direction. It mainly includes a drive unit (not shown) for driving the motor. The stator core 11 has a cylindrical shape, and a plurality of slots 13 are formed in the axial end face of the stator core 11 at predetermined intervals in the circumferential direction of the stator core 11 . A plurality of slots 13 are formed along the radial direction of the stator core 11 . A segment coil 1 constituting a stator coil is accommodated in each slot 13 , and a protruding portion 2 protrudes to one side of the stator core 11 in the axial direction. Before bending by the bending jig 12, the projecting portion 2 of each segment coil 1 extends linearly along the axial direction of the stator core 11, as shown in FIG. None.

The bending jig 12 has a cylindrical shape. For example, as shown in FIG. 12 are formed at predetermined intervals in the circumferential direction. Here, a plurality of bending jigs 12 having different outer diameters are arranged concentrically at positions facing the stator core 11 in the axial direction, and the bending jigs 12 are independent of each other. It is configured to be axially rotatable while moving in the axial direction. More specifically, the positions and positions related to axial movement and axial rotation can be twisted (applied S-shaped bending deformation) to a predetermined twisting angle (applied S-shaped bending deformation) to the projecting portion 2 of the segment coil 1 inserted into the groove portion 14 . Each speed is controllable.

Further, the molding apparatus 10 according to this embodiment further includes an alignment device 16 as shown in FIG. This aligning device 16 is for aligning and aligning the circumferential positions of the distal ends 3 of the plurality of projections 2 forming a row. and a moving device 19 for moving the alignment jig 18 . In the present embodiment, long plate-like alignment jigs 18 are oriented parallel to the radial direction of stator core 11 , and these alignment jigs 18 are reciprocated along the longitudinal direction, that is, the radial direction of stator core 11 . A moving device 19 is configured to be movable.

Here, each pair of alignment jigs 18 has a pair of regulating surfaces 17 that face each other in the circumferential direction of the stator core 11 and are capable of regulating the circumferential position of the distal end portion 3 . The pair of regulating surfaces 17 are parallel to each other, and the parallel relationship is maintained even when each pair of alignment jigs 18 is moved. In addition, the spacing between the pair of restricting surfaces 17 is set to a predetermined size in consideration of not only the dimensions of the plurality of distal end portions 3 to be restricted but also possible variations in circumferential position. Of course, the opposing interval between the pair of restricting surfaces 17 may be configured to be appropriately changeable.

In this embodiment, the alignment device 16 configured as described above, that is, a plurality of pairs of alignment jigs 18 and moving devices 19 are arranged in the central hollow portion of the stator core 11 . In this case, each pair of aligning jigs 18 moves the distal end portion 3 of the protrusion 2 on the outermost diameter side among the plurality of protrusions 2 forming a row to a radial position where it can be aligned, and 1 and 4 to a position in the radial direction where it can be retracted to the inner diameter side of the distal end portion 3 of the projecting portion 2 (see FIGS. 1 and 4).

Next, an example of a method of forming a stator coil using the forming apparatus 10 having the above configuration will be described.

As shown in FIG. 2, this molding method comprises an alignment step S1 of aligning the tips 3 of a plurality of rows of projections 2, and inserting the aligned tips 3 into grooves 14 of a jig 12 for bending. An inserting step S2 and a bending step S3 of performing a predetermined bending process on the projecting portion 2 whose tip portion 3 is inserted into the groove portion 14 are provided. Details of each of the steps S1 to S3 will be described below, focusing on the alignment step S1.

(S1) Alignment step In this step S1, as shown in FIG. 1, the plurality of segment coils 1 are arranged in the central hollow portion of the stator core 11 with the protrusions 2 accommodated in the corresponding slots 13 of the stator core 11. A plurality of pairs of alignment jigs 18 are advanced in a direction along the radial direction of the stator core 11 . As a result, a plurality of rows of protrusions 2 are introduced between the pair of regulating surfaces 17 of each pair of alignment jigs 18, and the circumferential positions of the distal ends 3 of the protrusions 2 are regulated. , the circumferential positions of the tip portions 3 are aligned (see FIGS. 3 and 4).

At this time, by providing a guide surface 20 such as a tapered surface at the front end portion of the alignment jig 18 (see FIG. 5), the tip portions 3 of the plurality of protrusions 2 forming a row are aligned in pairs. can be easily introduced between the regulating surfaces 17 of the

(S2) Insertion Step In this step S2, the tips 3 of the plurality of rows of protrusions 2 aligned in the circumferential direction in the alignment step S1 are inserted into the corresponding grooves 14 of the bending jig 12 . That is, as shown in FIG. 6(a), the bending jig 12 located above the distal end portion 3 introduced between each pair of alignment jigs 18 is directed toward the stator core 11 side. to move it axially. As a result, as shown in FIG. 6B, part of the distal end portion 3 aligned in the circumferential direction is inserted into the groove portion 14 of the bending jig 12 . At this stage, the tip portions 3 of the plurality of protrusions 2 forming each row are in a state of being introduced between the corresponding pairs of alignment jigs 18 (between the pair of restricting surfaces 17). The insertion of 14 can be started with the circumferential positions of the tips 3 reliably aligned.

(S3) Bending Step After the insertion of the distal end portion 3 into the groove portion 14 is started in this manner, each pair of alignment jigs 18 is retracted by the moving device 19 . At this time, by retracting each pair of alignment jigs 18 to the inner diameter side of the protrusion 2 closest to the inner diameter among the protrusions 2 in each row, the alignment jigs 18 are aligned from both sides in the circumferential direction of all the distal end portions 3 . The jig 18 is retracted (see FIG. 6(c)). After that, the bending jig 12 is further moved in the axial direction toward the stator core 11, so that the tip portion 3 has been inserted to a predetermined position in the groove portion 14 (see FIG. 6(d)). reference). Therefore, by axially rotating the bending jig 12 from this state, or by axially rotating the bending jig 12 along with axial movement, each projecting portion 2 is subjected to a bending process accompanied by twisting.

As described above, the stator coil molding apparatus 10 according to the present embodiment is further provided with the aligning device 16 capable of aligning the circumferential positions of the distal ends 3 of the plurality of projections 2 forming each row. bottom. As a result, the circumferential positions of the distal end portions 3 of the projecting portions 2 can be aligned without omission, so regardless of the shape (magnitude of curvature) of the opening side edge portion 15 of the groove portion 14 of the bending jig 12, It becomes possible to reliably insert the tip portion 3 into the groove portion 14 . Therefore, by reducing the curvature radius of the opening-side edge portion 15 of the groove portion 14, it is possible to keep the coil end H after bending low while avoiding the situation where the tip portion 3 is crushed (see FIG. 9). (See FIG. 7(b)).

Further, in the present embodiment, the alignment device 16 includes at least an alignment jig 18 having a pair of regulation surfaces 17 facing each other in the circumferential direction of the stator core 11 and capable of regulating the circumferential position of the distal end portion 3, and an alignment jig 18. It is composed of a moving device 19 that allows the tool 18 to move along the radial direction of the stator core 11 . Then, each pair of aligning jigs 18 moves to a radial position where the distal end portion 3 of the projection 2 on the outermost diameter side among the plurality of projections 2 forming a row can be aligned, and The aligning device 16 is configured so as to be movable to a radial position at which it can be retracted to the inner diameter side of the distal end portion 3 of the projecting portion 2 . By configuring in this way, the entire alignment device 16 described above can be arranged in the central hollow portion of the stator core 11 . Therefore, the aligning device 16 can be arranged without requiring a new installation space, thereby making it possible to achieve stable bending and a low coil end while avoiding an increase in the size of the molding device 10 as a whole. .

Although one embodiment of the present invention has been described above, the apparatus or method for forming a stator coil according to the present invention can adopt configurations other than those described above without departing from the scope of the present invention.

For example, in the above-described embodiment, the aligning device 16 aligns the circumferential positions of the portions of the protruding portions 2 of the segment coil 1 from which the insulating coating is removed, that is, the portions where the conductors are exposed, as the distal end portion 3. Of course, the portions of the projecting portion 2 covered with the insulating film may be aligned in the circumferential direction by the aligning device 16 (in the case of the above embodiment, by the pair of restricting surfaces 17).

Alternatively, in the above-described embodiment, the circumferential positions of the distal end portions 3 are aligned by the aligning device 16. It may be introduced between the surfaces 17 so that the introduced portions are aligned in the circumferential direction.

Further, in the above-described embodiment, the case where each pair of alignment jigs 18 is configured to be slidable only in the radial direction was exemplified, but this is of course not the only option. For example, although illustration is omitted, from a state in which the distal end portions 3 of the plurality of protrusions 2 arranged in a row between the pair of restricting surfaces 17 are introduced, the protrusions 2 are moved along the radial direction while the interval between the opposing portions in the circumferential direction is widened. Each pair of aligning jigs 18 may be brought closer to narrow the interval between the pair of restricting surfaces 17 facing each other. In short, as long as the aligned state as shown in FIG. 5 can be achieved, the configuration including the operation of the alignment device 16 is arbitrary.

1 Segment Coil 2 Projection 3 Tip 10 Forming Device 11 Stator Core 12 Processing Jig 13 Slot 14 Groove 15 Opening Side Edge 16 Alignment Device 17 Control Surface 18 Alignment Jig 19 Moving Device 20 Guide Surface H Coil End S1 Alignment Step S2 Insertion step S3 Bending step

Claims (3)

A device for forming a stator coil by subjecting a segment coil accommodated in a slot of a stator core to a bending process accompanied by twisting,
a bending jig having a tubular shape and having a groove into which a tip end of a projecting portion of the segment coil projecting to one axial side of the stator core can be inserted;
A stator coil forming apparatus comprising a driving unit for axially rotating the bending jig while moving it in the axial direction,
The projecting portions of the segment coils are arranged in a plurality of rows in a radial direction of the stator core,
The apparatus for forming a stator coil, further comprising an aligning device capable of aligning and aligning the distal ends of the plurality of protrusions forming each row in the circumferential direction. The aligning device includes an aligning jig having a pair of regulating surfaces facing each other in the circumferential direction of the stator core and capable of regulating the circumferential position of the distal end portion, and the aligning jig along the radial direction of the stator core. a moving device that enables movement,
The aligning jig moves the distal end of the outermost projection out of the plurality of projections forming the row to a radial position where alignment is possible, and moves the distal end of the projection closest to the inner diameter. 2. The stator coil forming apparatus according to claim 1, which is configured to be movable to a radial position at which it can be retracted toward the inner diameter side. A method for forming a stator coil by subjecting a plurality of segment coils accommodated in slots of a stator core to bending with twisting, comprising:
an inserting step of inserting distal ends of projections of the segment coils projecting toward one axial side of the stator core into a plurality of grooves provided in a tubular bending jig;
A method for forming a stator coil, comprising a bending step of performing the bending process on the projecting portion by axially rotating the bending jig while moving the bending jig in the state in which the tip portion is inserted. in
tip portions of the segment coils are arranged in a plurality of rows in a radial direction of the stator core,
The method of forming a stator coil, further comprising, prior to the inserting step, an aligning step of aligning and aligning the plurality of distal end portions forming each row in the circumferential direction using an aligning device.

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