JP7060487B2 - Manufacturing method of rotary electric stator - Google Patents

Description

The present invention relates to a method for manufacturing a rotary electric machine stator, particularly a method for adjusting the position of the tip of a segment coil used for the stator.

A plurality of axially penetrating slots are formed in the stator core of the rotary electric machine, and when two parallel legs of the U-shaped segment coil are inserted into different slots from the bottom to the top, a part of the legs is inserted. It is a protrusion that protrudes upward from the slot. The stator is manufactured by welding the tip of the protrusion of the segment coil whose legs are inserted into the slot in this way to the tip of the protrusion of the other segment coil whose legs are similarly inserted into the slot. The method is known. When welding the tips of the protruding portions of the segment coil in this way, it is necessary to align the positions of the tips of the protruding portions to be welded.

An adjustment jig having a claw portion protruding toward the stator core at the lower end presses the protruding portion of the segment coil protruding in the axial direction of the stator core from above and tilts it in the circumferential direction of the stator core, thereby causing the shaft at the tip of the protruding portion. The position of the direction is adjusted, and the adjustment jig rotates in the circumferential direction of the stator, so that the claw part presses the tip of the protrusion in the circumferential direction to adjust the position in the circumferential direction, and the tip of the protrusion is positioned. The method is disclosed in Patent Document 1.

JP-A-2017-0850806

By the way, by lowering the adjusting jig in the axial direction and rotating it in the circumferential direction of the stator core while approaching the stator core, the axial and circumferential positions of the tip of the protruding portion of the segment coil can be adjusted. However, since the thickness of the stator core in the axial direction varies and the length of the segment coil varies from production lot to production lot, the length of the protrusion varies from one stator core to another. If the variation in the length of the protrusion is within a certain range from the reference line length, the position of the tip of the segment coil can be adjusted to a certain position even if the trajectory of the adjusting jig is constant. However, if the length of the protrusion is too long or too short and exceeds the range that can be adjusted with a certain trajectory of the adjustment jig, the position of the tip of the protrusion in the circumferential direction or the axial direction even if adjusted with the adjustment jig. It may be misaligned and problems such as welding defects may occur.

Therefore, an object of the present invention is to improve the accuracy of the position of the tip of the protruding portion after adjustment by the adjusting jig even when the length of the protruding portion of the segment coil is different from the reference line length.

In the method for manufacturing a rotary electric stator according to the present invention, two legs of a U-shaped segment coil having two legs parallel to each other and a connecting portion connecting the two legs are provided in different slots of the stator core. The insertion process of inserting the protruding part, which is a part of the leg part, from the slot in the axial direction of the stator core, and the adjusting jig provided with the claw part protruding toward the stator core are moved axially to the stator core. By rotating in the circumferential direction of the stator core while approaching, the protruding part is tilted in the circumferential direction from the state where it protrudes in the axial direction to adjust the axial position of the tip of the protruding part, and the claw part presses the tip of the tip. In the method of manufacturing a rotary electric machine stator including a tip positioning step for adjusting the position in the circumferential direction, the length of the protruding portion is measured for each stator core after the insertion step, and the difference from the reference line length of the protruding portion is used. It is equipped with a correction trajectory calculation process that calculates the distance to move the adjustment jig in the axial direction, and calculates the correction trajectory that corrects the reference trajectory that moves the adjustment jig in the axial direction and rotates it in the circumferential direction while approaching the stator core. The process is characterized in that the adjusting jig is operated in the correction trajectory to adjust the axial and circumferential positions of the tip of the protrusion.

The present invention measures the length of the protruding portion even when the length of the protruding portion of the segment coil is different from the reference line length, and calculates a corrected trajectory corrected for the reference trajectory from the difference from the reference line length of the protruding portion. However, since the adjustment jig is operated in the correction trajectory to adjust the position of the tip of the protrusion, the accuracy of the position of the tip of the protrusion can be improved.

It is a flowchart which shows the manufacturing method of the Embodiment of this disclosure. It is a side view which shows the state which the leg part of the segment coil is inserted into the slot of a stator core by the insertion process of the manufacturing method of an Embodiment. It is a side view which shows the state which the position of the tip of the protrusion of the segment coil is aligned by the tip positioning process of an embodiment. It is a side view which shows the apparatus for bending the protruding part of the segment coil used in the tip positioning process of an embodiment. It is a perspective view which shows the part in the circumferential direction by omitting a part in the state which the adjustment part is seen from diagonally below. FIG. 5 is an enlarged view of part A in FIG. It is a side view (a) explaining the method of adjusting the position of the tip of the protrusion of the segment coil with an adjustment jig, and the figure (b) which shows the locus drawn by the lower end of a claw part. It is a flowchart which shows the method of calculating the reference trajectory of the adjustment jig when the length of the protrusion of the segment coil is a reference line length, and operating the adjustment jig in the reference trajectory. It is a flowchart which shows the method of calculating the correction trajectory of the adjustment jig, and operating the adjustment jig in the correction jig. It is a figure which shows an example of the correction trajectory of the adjustment jig. It is the figure which showed the variation of the position in the circumferential direction of the tip of the protrusion of a segment coil in comparison with the case which adjusted in a reference trajectory, and the case which adjusted in a correction trajectory. It is a figure which compared the case where the height in the axial direction of the protrusion of a segment coil was adjusted in a reference trajectory, and the case where it was adjusted in a correction trajectory.

Hereinafter, a method of manufacturing the rotary electric machine stator of the embodiment will be described with reference to the drawings. Unless otherwise specified, the axial direction, the circumferential direction, and the radial direction described below shall indicate the axial direction of the stator core 1, the circumferential direction of the stator core 1, and the radial direction of the stator core 1, respectively.

FIG. 1 is a flowchart showing a method of manufacturing a rotary electric machine stator according to an embodiment. First, the insertion step of step S1 will be described. As shown in FIG. 2A, the stator core 1 is configured by laminating an electromagnetic steel sheet 11 in the axial direction of the stator core 1. A plurality of slots 12 penetrating in the axial direction are formed in the stator core 1. The U-shaped segment coil 2 has two legs 21 parallel to each other and a connecting portion 22 connecting the two legs 21. The two legs 21 of the segment coil 2 are inserted into different slots 12 of the stator core 1, and the protruding portions 23, which are a part of the leg portions 21, project from the slots 12 in the axial direction of the stator core 1.

As shown in FIGS. 2A and 2B, the length of the protrusion 23 varies due to the variation in the axial thickness of the stator core 1 and the variation in the line length of the segment coil 2. FIG. 2A shows a case where the stator core 1 is thick in the axial direction and the wire length of the segment coil 2 is short, and the length of the protruding portion 23 is short. FIG. 2B shows a case where the thickness of the stator core 1 in the axial direction is thin and the wire length of the segment coil 2 is long, and the length of the protruding portion 23 is long.

Next, the tip positioning step of step S3 in FIG. 1 will be described first. In order to complete the stator in which the coil is wound around the stator core 1, it is necessary to weld the tip 24 of the protruding portion 23 of the segment coil 2 and the tip 24 of the protruding portion 23 of the other segment coil 2. Therefore, as shown in FIG. 3, the protruding portions 23 of the pair of segment coils 2 adjacent to each other in the radial direction of the stator core 1 are tilted in opposite directions in the circumferential direction of the stator core 1 so that the tip 24 of the protruding portion 23 It is necessary to align the axial and circumferential positions.

Therefore, the position of the tip 24 of the protrusion 23 is adjusted by using the bending device 3 shown in FIG. The bending device 3 includes a holding unit 31 for holding the stator core 1, an adjusting unit 4, a jig driving unit 32, and a control unit 33. The holding portion 31 grips and holds the lower end portion of the stator core 1 in a state where the leg portion 21 of the segment coil 2 is inserted into the slot 12 and the protruding portion 23 protrudes in the axial direction. The adjusting portion 4 bends the protruding portions 23 of the plurality of segment coils 2 in the circumferential direction of the stator core 1 to adjust the positions of the distal end 24 of the protruding portions 23 in the circumferential direction and the axial direction. The adjusting portion 4 is arranged above the stator core 1 held by the holding portion 31, and is supported below the fixing member 34 via the jig driving portion 32.

As shown in FIGS. 4 and 5, the adjusting portion 4 is arranged around a shaft O1 located on an extension of the central axis of the stator core 1 and has a cylindrical portion, and is arranged inside the support portion 41. It is composed of a plurality of adjusting jigs 42 to 47 and a plurality of separators 48. FIG. 5 is a perspective view of the adjusting portion 4 viewed from diagonally below, and describes the plurality of adjusting jigs 42 to 47 and the plurality of separators 48, and the description of the supporting portion 41 is omitted. FIG. 6 is an enlarged view of the portion A surrounded by the alternate long and short dash line in FIG.

As shown in FIGS. 5 and 6, the plurality of adjusting jigs 42 to 47 have a cylindrical shape having different diameters from each other, and are arranged so as to be aligned in the radial direction with their central axes aligned. The plurality of separators 48 have a cylindrical shape having different diameters from each other, and are arranged between the adjusting jigs 42 to 47 adjacent to each other in the radial direction. Claws 49 protruding toward the stator core 1 are provided at a plurality of positions at equal intervals in the circumferential direction at the lower ends of the adjusting jigs 42 to 47, which are the side ends of the stator core 1. The lower end of the separator 48, which is the end on the stator core 1 side, protrudes below the lower end of the claw portion 49 of the adjusting jigs 42 to 47. The radial thickness of the adjusting jigs 42 to 47 is larger than the thickness of the separator 48. Each of the adjusting jigs 42 to 47 is integrated with a separator 48 adjacent to the inside of the adjusting jigs 42 to 47 in the radial direction, and is moved in the axial direction and rotated in the circumferential direction by the jig driving unit 32.

When the jig 23 is bent by the adjusting portion 4 to adjust the position of the tip 24, the jig driving unit 32 moves the adjusting jigs 42 to 47 in the axial direction to bring them closer to the stator core 1 and rotate them in the circumferential direction. The jig drive unit 32 rotates two adjusting jigs adjacent to each other in the radial direction in opposite directions. That is, when the adjusting portion 4 bends the protruding portion 23 to adjust the position of the tip 24, the adjusting jig 42, the adjusting jig 44, and the adjusting jig 46 rotate clockwise when viewed from above in FIG. 43, the adjusting jig 45 and the adjusting jig 47 rotate counterclockwise when viewed from above in FIG. By rotating the adjusting jig 42 and the adjusting jig 43 in the opposite directions in this way, as shown in FIG. 3, the protrusions 23 of the pair of segment coils 2 adjacent to each other in the radial direction of the stator core 1 are formed around the stator core 1. It can be tilted in opposite directions. Similarly, by rotating the adjusting jig 44 and the adjusting jig 45 in the opposite directions, the pair of radially adjacent protrusions 23 are tilted in the opposite direction, and the adjusting jig 46 and the adjusting jig 47 are rotated in the opposite directions. , The pair of projecting portions 23 adjacent in the radial direction can be tilted in the opposite direction.

The jig drive unit 32 includes a motor for moving in the axial direction and a motor for rotating in the circumferential direction, and the control unit 33 controls these motors. The control unit 33 has a CPU, which is an arithmetic processing unit, and a storage unit such as RAM and ROM. The CPU has a function of executing a program stored in advance in the storage unit.

Here, the operation of the adjusting jig 43 among the adjusting jigs 42 to 47 will be described below. As shown in FIG. 7A, the jig drive unit 32 moves the adjusting jig 43 in the axial direction of the stator core 1 and rotates in the circumferential direction of the stator core 1 while approaching the stator core 1, thereby moving upward from the stator core 1. The positions of the tip 24 of the protruding portion 23 in the axial direction and the circumferential direction are adjusted. In order to explain the trajectory of the adjusting jig 43, the trajectory drawn by the lower end of the claw portion 49 due to the operation of the adjusting jig 43 is shown in FIG. 7 (b). As shown in FIG. 7B, this trajectory is composed of a first orbit α1, a second orbit α2, and a third orbit α3. In the first trajectory α1, the protrusion 23 is tilted in the circumferential direction by rotating the adjusting jig 43 in the circumferential direction while bringing the adjusting jig 43 closer to the stator core 1. Next, in the second orbit α2, the adjusting jig 43 is rotated in the circumferential direction of the stator core 1 and the tip 24 is hooked on the claw portion 49. Next, in the third orbit α3, the adjusting jig 43 is rotated in the circumferential direction of the stator core 1 while being brought close to the stator core 1, so that the tip 24 of the protrusion 23 is pushed in to determine the final position of the tip 24.

As described above, the length of the protrusion 23 varies due to the variation in the axial thickness of the stator core 1 and the variation in the line length of the segment coil 2. When the length of the protrusion 23 is the reference line length, the adjusting jigs 42 to 47 are operated on the reference trajectory calculated in the flowchart shown in FIG. To calculate the reference trajectory, first, in step S11, the trajectory of the protruding portion 23 whose length is the reference line length is created by CAD (computer-aided design). Next, in step S12, the claw portions 49 of the adjusting jigs 42 to 47 are arranged on the CAD in accordance with the locus of the tip 24 of the protruding portion 23 which is the reference line length. Next, in step S13, the loci of the adjusting jigs 42 to 47 according to the arrangement of the claw portion 49 are replaced with an approximate expression. The reference trajectory is calculated by the above operations from step S11 to step S13. Then, in step S14, the adjusting jigs 42 to 47 operate in the reference orbit by operating the jig driving unit 32 in the control unit 33 by using the approximate expression calculated in step S13 in the program.

Next, the correction trajectory calculation step in step S2 of FIG. 1 will be described. As described above, the length of the protrusion 23 varies from one stator core to one. Depending on the length of the protruding portion 23, the locus of the protruding portion 23 when the protruding portion 23 is tilted in the circumferential direction to adjust the position of the tip 24 differs. If the length of the protrusion 23 is too short than the reference line length, even if the adjustment jigs 42 to 47 are operated in the reference trajectory, the tip 24 is pushed in in the circumferential direction with the protrusion 23 insufficiently tilted. The position of the tip 24 after adjustment by the adjustment jigs 42 to 47 may be displaced in the circumferential direction because the tip 24 may not be sufficiently pushed. Further, if the length of the protruding portion 23 is too long than the reference line length, even if the adjusting jigs 42 to 47 are operated on the reference trajectory, the two segment coils to be welded due to the bending near the tip 24 of the protruding portion 23. There may be a step in the height of the tip 24 of 2. If the tips 24 of the segment coils 2 are welded to each other in a state where the positions of the tips 24 are displaced in the circumferential direction or a step is formed in the axial direction, welding defects may occur.

Therefore, after the insertion step of step S1 in FIG. 1, the length of the protruding portion 23 is measured for each stator core 1, and the distance for moving the adjusting jigs 42 to 47 in the axial direction is calculated from the difference from the reference line length. , The adjustment jig 42 to 47 is moved in the axial direction and rotated in the circumferential direction while approaching the stator core 1. A correction orbit is calculated, and the adjustment jig 42 is used in the tip positioning step of step S3 of FIG. -47 is operated to adjust the axial and circumferential positions of the tip 24.

The correction trajectory is calculated by the work from steps S21 to S24 in the flowchart shown in FIG. To calculate the correction trajectory, first, in step S21, the line length of the protrusion 23 is measured. Next, in step S22, the difference from the reference line length of the protruding portion 23 is calculated. Even with the same stator core 1, the length of the protrusion 23 may vary from slot to slot. Therefore, for example, the line lengths of the protrusions 23 of all the slots 12 are measured, and the average value is taken as the line length of the protrusions 23. Calculate the difference from the reference line length. Regarding the line length measurement of the protrusions 23, the line lengths of all the protrusions 23 are not measured for each slot 12, but the line lengths of the plurality of protrusions 23 are measured for some of the slots 12 and the average value is projected. The difference from the reference line length may be calculated as the line length of the unit 23.

Next, in step S23, the X coordinate and the Y coordinate of the correction orbit are calculated by using a trigonometric function for each coil tilt angle θ of the reference orbit. The X coordinate is the moving distance in the circumferential direction of the claw portion 49, and the Y coordinate is the moving distance in the axial direction of the adjusting jigs 42 to 47. The coil tilt angle θ is an angle at which the tip end portion of the protruding portion 23 of the segment coil 2 is tilted. The coil tilt angle θ is 90 degrees when the protrusion 23 is standing upward, and 0 degrees when the tip of the protrusion 23 is completely horizontally tilted. Assuming that the difference from the reference line length is L, the Y coordinate of the correction orbit is Y, the Y coordinate of the reference orbit is Ys, and the pi is π, the Y coordinate of the correction orbit is calculated by, for example, the following equation 1.

Y = Ys + L × sin (θ / 180 × π) ・ ・ ・ (Equation 1)

Similarly, assuming that the X coordinate of the correction orbit is X and the X coordinate of the reference orbit is Xs, the X coordinate of the correction orbit is calculated by, for example, Equation 2 below.

X = Xs + L × cos (θ / 180 × π) ・ ・ ・ (Equation 2)

In Equations 1 and 2, the difference L is calculated as a positive value when it is longer than the reference line length and as a negative value when it is shorter than the reference line length.

Next, based on the X and Y coordinates of the correction orbit calculated for each coil tilt angle θ of the reference orbit in step S23, the correction orbit is calculated by substituting with an approximate expression in the next step S24. The correction trajectory is calculated by the above operations from step S21 to step S24.

Then, in step S25, the adjustment jigs 42 to 47 operate in the correction trajectory by operating the jig drive unit 32 in the control unit 33 by using the approximate expression calculated in step S24 in the program.

FIG. 10 shows an example of the correction trajectory calculated by the work from step S21 to step S24 in FIG. In the tip positioning step of step S3 of FIG. 1, the length of the protruding portion 23 is increased by operating the adjusting jigs 42 to 47 in the correction trajectory to adjust the axial and circumferential positions of the tip 24 of the protruding portion 23. Even if the length is different from the reference line length, the accuracy of the axial and circumferential positions of the tip 24 of the protrusion 23 can be improved.

FIG. 11 is a diagram showing variations in the circumferential position of the tip 24 of the protrusion 23 after operating the adjusting jig 43 for each slot 12 when the length of the protrusion 23 is shorter than the reference line length. Is. The variation width W1 when the position of the tip 24 is adjusted in the correction orbit is about 35% smaller than the variation width W2 when the position of the tip 24 is adjusted in the reference orbit.

FIG. 12 shows a case where the height of the protrusion 23 in the axial direction after operating the adjusting jig 43 is adjusted in the reference trajectory when the length of the protrusion 23 is longer than the reference line length, and a correction trajectory. It is a figure which compared with the case which adjusted in. The solid line graph is when adjusted with the corrected orbit, and the broken line graph is when adjusted with the reference orbit. When adjusted in the reference trajectory, the height in the axial direction is less than 0.5 mm within the welding range R1, and welding defects may occur. However, when adjusted with the corrected track, the height in the axial direction within the welding range R1 is 0.5 mm or more at which welding defects do not occur.

As shown in FIG. 3, a pair of segment coils 2 adjacent to each other in the radial direction of the stator core 1 by the insertion step of step S1 of FIG. 1, the correction trajectory calculation step of step S2, and the tip positioning step of step S3 described above. The protrusions 23 can be tilted in opposite directions in the circumferential direction of the stator core 1 to align the axial and circumferential positions of the tip 24 of the protrusions 23. After that, in the welding step of step S4 of FIG. 1, the tips 24 of the protruding portions 23 of the segment coils 2 adjacent in the radial direction in which the positions in the axial direction and the circumferential direction are aligned are welded to each other. This welding process completes a stator in which a coil is wound around the stator core 1.

The method for manufacturing a rotary electric stator of the present disclosure is not limited to the above-mentioned form, and can be carried out in various forms within the scope of the gist of the present disclosure. For example, the calculation formula for calculating the correction trajectory of the above-mentioned form is an example, and the correction trajectory may be calculated by a calculation formula different from the formula 1 and the formula 2. Further, the protruding portion 23 may protrude downward from the slot 12, and the adjusting jigs 42 to 47 may be brought closer to the stator core 1 from the lower side to the upper side when the protruding portion 23 is tilted. Further, the number of adjusting jigs may be different from six. Further, the shape of the claw portion 49 may be another shape as long as the claw portion 49 can press the tip 24 of the protruding portion 23 in the circumferential direction of the stator core 1.

1 stator core, 2 segment coil, 3 bending equipment, 4 adjustment part, 11 electrical steel sheet, 12 slot, 21 leg part, 22 connection part, 23 protrusion part, 24 tip, 31 holding part, 32 jig drive part, 33 control Part, 34 fixing member, 41 support part, 42-47 adjustment jig, 48 separator, 49 claw part.

Claims (1)

The two legs of a U-shaped segment coil having two legs parallel to each other and a connecting portion connecting the two legs are inserted into different slots of the stator core to form a part of the legs. The insertion step of projecting the protruding portion from the slot in the axial direction of the stator core,
A state in which the protruding portion protrudes in the axial direction by moving the adjusting jig provided with the claw portion protruding toward the stator core in the axial direction and rotating in the circumferential direction of the stator core while approaching the stator core. The tip positioning step of adjusting the axial position of the tip of the protrusion by tilting the tip in the circumferential direction, and adjusting the position of the tip in the circumferential direction by pressing the tip with the claw portion.
In the method of manufacturing a rotary electric stator including
After the insertion step, the length of the protrusion is measured for each stator core, the distance for moving the adjustment jig in the axial direction is calculated from the difference from the reference line length of the protrusion, and the adjustment jig is calculated. A correction orbit calculation step for calculating a correction orbit that corrects a reference orbit that moves in the axial direction and rotates in the circumferential direction while approaching the stator core is provided.
A method for manufacturing a rotary electric machine stator, characterized in that, in the tip positioning step, the adjusting jig is operated on the correction trajectory to adjust the axial and circumferential positions of the tip of the protruding portion.

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