JP2014128129A - Stator manufacturing method, coil twisting jig and stator manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stator manufacturing method employing segment coil twisting which may result in reduction of an insulation defect.SOLUTION: According to a stator manufacturing method, a segment Sg is formed by bending an insulation-coated rectangular conductor D, a distal end of the segment Sg is exfoliated, and the segment Sg is inserted into a stator core 20. A coil twisting jig 110 is rotated in a circumferential direction of the stator core 20 by engaging the segment Sg and a groove part 112, an end portion of the segment Sg is molded, and a stator 10 is formed by welding the end portion of the segment Sg and performing insulation by means of powder coating. A tooth part 118 has a slope 116 on a supporting front surface 114 which is positioned at a side of a rotational travel direction of the coil twisting jig 110, a gap is formed between a shoulder part Sgk which is formed in the distal end of the segment Sg, and the slope 116 of the tooth part 118 in the state where the groove part 112 and the distal end of the segment Sg are engaged, and the coil twisting jig 110 is rotated to implement twisted formation in the state where the slope 116 and the shoulder part Sgk are not abutted.

Description

  The present invention relates to a technique for manufacturing a stator using a segment coil. Specifically, after inserting a substantially U-shaped segment into a slot of the stator, the end of the segment is twisted and welded to form a segment coil. The present invention relates to a technique for improving the life of a stator that is formed and formed by performing powder coating on a welded portion and performing insulation.

  In recent years, there have been an increasing number of cases in which a driving motor is mounted on an automobile. A drive motor mounted on a vehicle is required to be space-saving because the mounting space is limited. In addition, higher output is required to improve the driving performance of automobiles. In particular, hybrid vehicles must be equipped with both an engine and a drive motor in the engine room, and space constraints are severe. For this reason, further miniaturization of the motor is required. In addition, it is desirable that a motor used in a general machine be reduced in size and output.

  Patent Document 1 discloses a technique related to a stator manufacturing apparatus and a stator manufacturing method. A plurality of stacked cylindrical twisting jigs are used to hold the end portion of the electric conductor that is protruding from the slot on one end portion side of the stator core, and twist this. The twisting jig includes a twisting portion that is relatively movable in the circumferential direction and the axial direction with respect to the stator core, and can be twisted without causing an end of the electric conductor to come off.

  Patent Documents 2 and 3 disclose techniques related to a coil twisting method, a twisting jig, and a twisting device. Although the basic configuration is the same as that of Patent Document 1, the shape of the holding groove for holding the tip of the segment provided in the twisting jig is different. In the technique of Patent Document 2, the bottom portion of the holding groove is used as a positioning portion. In addition, a top portion formed in a substantially triangular shape in the holding groove, a side surface extending vertically from the positioning portion, and upward from the side surface. And an inclined surface rimmed so as to spread. On the other hand, in the technique of Patent Document 3, the holding groove is provided with a bottom portion used for positioning and a chamfered portion provided at the top portion. In both the techniques of Patent Document 2 and Patent Document 3, the segments are twisted so that the tip of the segment has an angle with the axis of the stator core.

  The techniques of Patent Documents 1 to 3 are all devised so as to shorten the length of the coil end of the stator, and are disclosed in Patent Document 2 and Patent Document 3 with respect to Patent Document 1. The technology can further reduce the coil end of the stator.

JP 2000-092797 A JP 2004-236375 A JP 2006-136082 A

  However, when a stator is manufactured using the techniques disclosed in Patent Documents 1 to 3, it is considered that there are problems described below.

  When the stator is manufactured by using the techniques disclosed in Patent Document 2 and Patent Document 3, it is difficult to secure a welding wire at the end of the segment protruding from the end of the stator core. In addition, since the segment is twisted, a springback of the material occurs due to the characteristics of the twist processing, and it is difficult to improve the segment tip position accuracy. Further, when twisting the segment coil, it is necessary to twist the end of the segment into an arc shape along the circumferential shape of the stator core. However, the gap between the end portions of the segment is designed to be narrow in order to increase the space factor of the stator, and it is difficult to constrain portions other than the end portions of the segment during twisting. This also makes it difficult to bend the end portion of the segment into a predetermined shape and increase the accuracy of the tip end position of the segment.

  For these reasons, it is considered desirable to twist the segment into a coil end shape as in Patent Document 1 where it is easy to ensure a portion to be held during welding. However, after the step of welding the end portions of the segments through the twisting process, an insulating coating process is required for the welded portion, but none of these points is mentioned in Patent Documents 1 to 3. . The applicant has proposed an insulating method by powder coating using an insulating material as an insulating coating treatment of the segment end after welding. However, according to the applicant's investigation, it has been found that when a method of insulating the end portion of the segment by powder coating is used, there is a concern that a partial insulation failure may occur when a stator endurance test is performed.

  Accordingly, in order to solve such problems, the present invention has an object to provide a stator manufacturing method, a coil twisting jig, and a stator manufacturing apparatus using twisting of a segment coil that leads to reduction of insulation failure. And

  In order to achieve the above object, a stator manufacturing method according to an aspect of the present invention has the following characteristics.

(1) A rectangular conductor with insulating coating is bent to form a substantially U-shaped segment, the insulating coating at the tip of the segment is peeled to form a peeling portion, and the segment is inserted into the stator core And engaging the groove formed between the tip of the segment and the tooth part of the coil twisting jig, rotating the coil twisting jig in the circumferential direction of the stator core, and Forming a stator, welding the end of the segment, and forming a stator by insulating the end of the welded segment by powder coating, in the coil twisting jig, The tooth portion has a notch portion on the support front surface facing the side of the segment inserted into the groove portion and positioned on the traveling direction side with respect to the rotation direction of the coil twisting jig, Segment With the end engaged, there is a gap between the tip of the non-peeling portion where the insulating coating is left from the peeling portion formed at the tip of the segment and the notch portion of the tooth portion. The coil twisting jig is rotated to form a twist in a state where the front surface of the support and the tip of the non-peeling portion are not in contact with each other.

  According to the aspect described in (1) above, the tip of the segment is twisted and then welded to form an insulating film by powder coating, which can contribute to reducing the occurrence of poor insulation of the stator. It becomes. As a result of the applicant's investigation, it has been confirmed that there is a certain rule regarding the occurrence of insulation failure in the stator. As a result of the endurance test of the stator, there were many cases where insulation failure occurred around the tip of the segment, and it was confirmed that a crack occurred from the base of the peeled portion at the tip of the segment. The occurrence of this crack is considered to have led to the occurrence of insulation failure, and as a cause thereof, the relationship between the tip of the segment and the twisting jig during twisting was suspected.

  As a result of observing the problematic part, it was found that the tip of the non-peeling portion extended from the peeled portion at the tip of the segment was deformed and a crack was generated from that portion. In other words, it is considered that cracks originated from the deformed portion are generated through the endurance test such as a thermal cycle test by deforming the tip of the non-peeled portion by applying pressure during twisting. For this reason, in the present invention, the shape of the tooth portion of the coil twisting jig is devised, and a notch is provided on the support front surface of the tooth portion so that a gap is formed between the tip of the non-peeling portion and the support front surface of the tooth portion. It is configured. That is, the notch portion avoids contact between the tip of the non-peeling portion and the support front surface of the tooth portion. As a result, the front surface of the support does not come into contact with the tip of the non-peeling portion during twisting, and no force is applied, and there is no fear of crushing the tip of the non-peeling portion with the force applied during twisting. By doing so, it is possible to eliminate the part that becomes the base point of the crack in the powder coating part provided at the end of the segment, and it is possible to contribute to the reduction of the occurrence of insulation failure of the stator.

(2) In the stator manufacturing method according to (1), the cutout portion formed in the tooth portion of the coil twisting jig is formed of an oblique side cut obliquely with respect to the support front surface. Features.

  According to the aspect described in (2) above, the deformation of the insulating coating shown in (1) is prevented, and when the coil twist jig is brought close to the tip of the segment, the tip of the segment is guided by the notch. Is possible. The tip of the segment is guided to the groove while abutting the notch formed by the hypotenuse. As a result, it is possible to prevent such a situation that the tip of the segment and the coil twisting jig interfere with each other and deform, and it can be expected to contribute to the improvement of the yield of the stator.

  In order to achieve the above object, a coil twisting jig according to an aspect of the present invention has the following characteristics.

(3) The insulating coating at the tip is peeled off, and the groove portion and the tooth portion that are engaged with the tip of the segment inserted into the stator core are alternately provided, and are provided rotatably in the circumferential direction of the stator core. In the coil twisting jig having an annular member, a plurality of the groove portions are provided in the circumferential direction, and a plurality of the tip ends of the segments can be twisted simultaneously, and the tooth portions include sides of the segments inserted into the groove portions. Is formed on the front end of the segment in a state where the groove front part and the front end of the segment are engaged with each other. A gap is formed between the front end of the non-peeling portion where the insulating coating provided from the peeling portion to be left is left and the support front surface of the tooth portion.

  According to the aspect described in (3) above, it is possible to contribute to a reduction in the occurrence of insulation failure of the stator. This is because the tip of the segment inserted into the stator core is twisted using a coil twisting jig having a notch on the support front surface of the tooth portion, so that the tip of the non-peeling portion at the tip of the segment is It can be prevented from being crushed. As a result, even when the insulating portion provided at the tip of the coil segment is covered by powder coating, it is possible to prevent the end of the tip of the non-peeling portion from starting as a crack. And it leads to reducing the possibility of generation | occurrence | production of the insulation defect of a stator.

(4) In the coil twisting jig according to (3), the cutout portion formed in the tooth portion of the coil twisting jig is formed of an oblique side cut obliquely with respect to the support front surface. Features.

  According to the aspect described in (4) above, the tip of the non-peeled portion shown in (1) and (3) is prevented from being crushed, and the tip of the segment is moved when the coil twist jig is brought close to the tip of the segment. It becomes possible to guide by the notch. The tip of the segment is guided to the groove while abutting the notch formed by the hypotenuse. As a result, it is possible to prevent such a situation that the tip of the segment and the coil twisting jig interfere with each other and deform, and it can be expected to contribute to the improvement of the yield of the stator.

  In order to achieve the above object, a stator manufacturing apparatus according to an aspect of the present invention has the following characteristics.

(5) The coil twisting jig of (3) or (4) is provided. For this reason, it is possible to prevent deformation of the tip of the non-peeled portion at the tip of the segment during twisting of the segment inserted into the stator core, and to prevent cracking in the powder coating applied to the coil end. As a result, it is possible to contribute to the reduction in the occurrence of insulation failure of the stator. In addition, by twisting the tip of the segment, the tip of the segment is guided by a notch formed as if it was cut diagonally, so that deformation due to interference between the segment and the coil twisting tool can be suppressed, and yield can be reduced. Can contribute to improvement.

It is a perspective view of the stator of this embodiment. It is a lead side expansion perspective view of the coil end part of a stator of this embodiment. It is a perspective view of a state where a segment was inserted into a stator core and a coil end portion was rear-expanded in this embodiment. It is a top view of the segment of this embodiment. It is the schematic of the assembly process of the stator of this embodiment. (A) It is a perspective view of a stator core. (B) It is the perspective view which equipped the stator core with the insulator. (C) It is a perspective view of a segment. (D) It is sectional drawing which shows a mode that the segment was inserted in the stator core. (E) It is sectional drawing which shows a mode that the segment was welded. It is a flowchart of the assembly process of a stator of this embodiment. It is an expanded sectional view of the slot part of the state of this embodiment in the state where the conductor part in a slot entered into the slot of the stator core. It is a perspective view which shows a mode that the front-end | tip of the segment inserted in the stator core of this embodiment was hold | maintained with the coil twist jig | tool. It is sectional drawing of the stator of this embodiment. It is a side view which shows a mode that the front-end | tip of a segment of this embodiment is inserted in a coil twist jig | tool. It is the side view which showed a mode that the front-end | tip of the segment of this embodiment was twisted with the coil twist jig | tool. It is a perspective view which shows the mode of the stator end surface by which this embodiment was twisted. It is a side view which shows a mode that the front-end | tip of the lead part of this embodiment was welded. It is sectional drawing of the lead part before twist forming of this embodiment. It is a side view which shows a mode that the front-end | tip of the segment prepared for the comparison was inserted in a coil twist jig | tool. It is the side view which shows a mode that the tip of the segment prepared for the comparison was twisted with the coil twisting jig. It is sectional drawing which shows the left side of the lead part front end prepared for the comparison. It is sectional drawing which shows the right side of the lead part tip prepared for the comparison.

  First, an embodiment of the present invention will be described with reference to the drawings. In addition, the detailed part of drawing used is simplified for convenience of explanation.

  In FIG. 1, the perspective view of the stator 10 of this embodiment is shown. FIG. 2 shows an enlarged perspective view of the lead side of the coil end portion of the stator 10. The stator 10 includes a stator core 20 and a segment coil SC. A stator core 20 formed by laminating electromagnetic steel plates having a substantially cylindrical shape is provided with a slot 12 between adjacent teeth 11 formed so as to protrude to the inner peripheral side. The number of teeth 11 prepared in the stator core 20 is 48, and the number of slots 12 is the same. Three ribs 21 and bolt holes 22 are provided on the outer peripheral side of the stator core 20. A motor cover or the like can be attached using the bolt holes 22. An insulator 25 having insulation properties shown in FIG. 2 is inserted into the slot 12. The insulator 25 ensures insulation between the segment coil SC and the stator core 20.

  FIG. 3 is a perspective view showing a state where the segment Sg is inserted into the stator core 20 and the coil end portion is rear-expanded. FIG. 4 shows a plan view of the segment Sg. The segment Sg is formed by edgewise bending the flat conductor D into a substantially U shape. The segment Sg is called in three parts for convenience. The in-slot conductor portion Sgb inserted into the slot 12 of the stator core 20, the lead portion Sga protruding from the end face of the stator core 20 toward the lead side of the stator 10, and the anti-lead portion Sgc. The lead portion Sga is referred to as a lead portion SgaA and a lead portion SgaB separately. The in-slot conductor portion Sgb is referred to as an in-slot conductor portion SgbA and an in-slot conductor portion SgbB. The anti-lead portion Sgc is composed of a crank portion Sge, a hypotenuse portion SgdA, and a hypotenuse portion SgdB. Then, the tips of the lead portion SgaA and the lead portion SgaB are peeled to be provided with a peeling portion Sgi described later.

  In FIG. 5, the outline of the assembly process of the stator 10 is shown. FIG. 5A shows a perspective view of the stator core 20. FIG. 5B shows a perspective view in which the stator core 20 is provided with an insulator 25. FIG. 5C shows a perspective view of the segment Sg. FIG. 5D is a cross-sectional view showing a state where the segment Sg is inserted into the stator core 20. FIG. 5E shows a cross-sectional view of the segment Sg welded. Note that the perspective view shown in FIG. 5 is simplified in shape for explanation. First, the segment Sg shown in FIG. 5 (c) is inserted into the slot 12 formed in the stator core 20 shown in FIG. 5 (a) with the insulator 25 inserted as shown in FIG. 5 (b). To do.

  As a result, the state shown in FIG. That is, the segment Sg partially protrudes from the end of the stator core 20, and the lead portion SgaA and the lead portion SgaB protrude. Then, the stator 10 is formed by twisting the lead portion SgaA and the lead portion SgaB and welding the tips to form the welded portion Sgf as shown in FIG. In addition, although the formation process of the stator 10 is notionally demonstrated in FIG. 5, in the actual assembly | attachment process, the alignment process which arrange | positions the segment Sg in a ring shape is required.

  FIG. 6 shows a flowchart of the assembly process of the stator 10. In S <b> 1, “straight conductor straightening and cutting” is performed. Since the flat conductor D is wound around a bobbin (not shown), the flat conductor D is unwound and trimmed to a required length. In S2, “segment formation” is performed. The flat conductor D is edgewise bent, and a crank portion Sge is created using a die (not shown) to obtain a substantially U-shaped segment Sg. In S3, “segment alignment” is performed. The segment Sg is arranged in a cylindrical shape by combining the crank portions Sge of the segment Sg so that eight in-slot conductors SgbA or eight in-slot conductors SgbB can be accommodated in the slot 12 of the stator core 20 to form a segment coil SC. To do.

  In S4, “insulator insertion” is performed. Each slot 12 is provided with an insulator 25 in the slot 12 of the stator core 20 in order to insulate the stator core 20 from the segment coil SC. In this step, the insulator 25 is inserted into the slot 12. In S5, “segment coil insertion” is performed. Strictly speaking, this is a step of bringing the segment coil SC close to the stator core 20 and inserting the lead portion Sga into the slot 12 provided with the insulator 25.

  In S6, “wedge insertion” is performed. FIG. 7 shows an enlarged cross-sectional view of a portion of the slot 12 in a state where the in-slot conductor portion Sgb enters the slot 12 of the stator core 20. The wedge paper 13 is inserted into the innermost peripheral side of the stator core 20 in a state where eight in-slot conductor portions Sgb of the segment Sg are inserted into the slot 12. The wedge paper 13 is held by being stretched by a convex portion 11 a provided at the tip of the tooth 11 so as to project into the slot 12. In S7, “extended after lead portion” is performed. This is a step of separating the lead portions Sga into two pairs.

  In S8, “twist formation” is performed. The lead portion Sga of the segment coil SC inserted into the stator core 20 is twisted in the radial direction of the stator core 20 and deformed into a shape in which adjacent coils are connected. As shown in FIG. 2, the lead portions Sga are twisted in different directions in the lead portions Sga adjacent in the radial direction. In S9, “Tig welding” is performed. As shown in FIG. 5E, the welded portion Sgf is formed by welding adjacent lead portions Sga to each other. In S10, “coil end portion insulation processing” is performed. This is a step of applying an insulating coating to the welded portion Sgf, and the insulating coating is performed using a resin in powder coating. Further, by impregnating the segment coil SC with varnish, the segment coil SC is fixed so that the segment coil SC does not move with respect to the stator 10 due to vibration transmitted from the vehicle body or the like when the stator 10 is operated.

  Next, the “twist forming” step of S8 will be described in more detail. FIG. 8 is a perspective view showing a state where the tip of the segment Sg inserted into the stator core 20 is held by the coil twisting jig 110. The twist forming apparatus 100 includes a coil twist jig 110 including a plurality of annular members. For convenience, the annular member disposed on the outer peripheral side is referred to as a first annular member 111, and the annular member disposed on the inner peripheral side is referred to as a second annular member 121. FIG. 9 shows a cross-sectional view of the stator. FIG. 9 shows a cross section of FIG. The state in which the segment coil SC is inserted into the stator core 20 and the process of “expansion after lead portion” in S7 is performed is the stator 10 shown in FIGS. In this state, eight segments Sg are inserted into one slot 12, and for convenience, the first lead portion Sga1, the second lead portion Sga2, the third lead portion Sga3, A fourth lead portion Sga4, a fifth lead portion Sga5, a sixth lead portion Sga6, a seventh lead portion Sga7, and an eighth lead portion Sga8 are provided. The first lead portion Sga1 to the eighth lead portion Sga8 are collectively referred to as a lead portion Sga group.

  In the above-described “rear expansion after the lead portion” step of S7, the lead portion Sga group protruding from the end face of the stator core 20 is separated between the second lead portion Sga2 and the third lead portion Sga3 by a rear expansion device (not shown). A gap is formed between the fourth lead portion Sga4 and the fifth lead portion Sga5, and between the sixth lead portion Sga6 and the seventh lead portion Sga7. In other words, the lead portions Sga are expanded in pairs so that they are separated in pairs. FIG. 10 is a side view showing how the tip of the segment Sg is inserted into the coil twisting jig 110. A plurality of groove portions 112 are formed in the first annular member 111. In the present embodiment, since 48 slots are prepared, 48 grooves 112 are provided in the first annular member 111.

  The groove portion 112 of the first annular member 111 includes a bottom portion 113, a support front surface 114, a support rear surface 115, and an inclined surface 116. The slope 116 is edged from the support front surface 114, and a cutout portion that is cut out at an angle with respect to the support front surface 114 is formed as the slope 116. The groove portion 112 is surrounded by an inclined surface 116, a support front surface 114, a bottom portion 113, and a support rear surface 115. On the other hand, the tooth part 118 is formed between the adjacent groove parts 112.

  As with the first annular member 111, the second annular member 121 is also formed with a groove 122 and a tooth 128 as shown in FIG. The second annular member 121 is formed to have a small outer diameter with respect to the first annular member 111 and is disposed on the inner peripheral side of the first annular member 111. Although not shown, the first annular member 111 and the second annular member 121 are rotatably held by the coil twisting jig 110. Further, the coil twisting jig 110 is provided with a moving mechanism so that it can be moved close to and away from the stator 10. In the actual twist forming process, the coil twist jig 110 having eight annular members may be used. However, in this embodiment, for convenience of explanation, the lead portions Sga are twisted by two rows in this embodiment. Shall.

  The first annular member 111 and the second annular member 121 are brought close to the coil end portion of the stator 10. In FIG. 10, the first annular member 111 is described, but the same applies to the second annular member 121. The first annular member 111 is brought close to the lead portion Sga, and the lead portion Sga and the groove portion 112 are engaged. At this time, the tip of the peeling portion Sgi is brought into contact with the bottom 113. In this state, the peeling portion Sgi is instructed to the side of the supporting front surface 114 and the supporting rear surface 115.

  Here, the eighth lead portion Sga8 disposed on the outermost periphery engages with the first annular member 111, and the seventh lead portion Sga7 disposed on the inner side engages with the second annular member 121. And At this time, a guide jig 150 is disposed on the end face of the stator core 20. The guide jig 150 is a rod-shaped jig that is arranged radially about the axis of the stator 10. The guide jig 150 has a guide surface 151 and an abutment surface 152, and the guide surface 151 has a substantially bowl shape with a chamfered top. The contact surface 152 is formed flat so as to be in contact with the end surface of the stator core 20 and to be stable.

  Thus, the state where the guide jig 150 and the coil twisting jig 110 are set on the stator 10 is as shown in FIG. In this state, the first annular member 111 and the second annular member 121 are rotated so as to move in directions opposite to each other. In FIG. 8, the first annular member 111 is rotated in the left direction in FIG. 8, and the second annular member 121 is rotated in the right direction in FIG. At the same time, the lead portion Sga is twisted by moving the first annular member 111 and the second annular member 121 to the stator 10 side.

  FIG. 11 is a side view showing a state where the tip of the segment Sg is twisted by the coil twisting jig 110. FIG. 12 is a perspective view showing the state of the end face of the stator formed by twisting. As shown in FIG. 11, the eighth lead portion Sga <b> 8 is twisted by the first annular member 111. The second annular member 121 twists the seventh lead portion Sga7 by rotating in the opposite direction to the first annular member 111. Each of the seventh lead portion Sga7 and the eighth lead portion Sga8 is formed with a curved surface along the guide surface 151 of the guide jig 150, and the tip side is formed by the tooth portions 118 of the first annular member 111 and the second annular member 121. A curved surface is formed. Thus, the lead portion Sga is edgewise bent into a crank shape. FIG. 13 is a side view showing a state where the tip of the lead portion Sga is welded. TIG welding performed in S9 is performed to form a welded part Sgf. Thus, the stator 10 is formed.

  Since this embodiment is the said structure, there exists an effect | action and effect which are demonstrated below.

  First, according to the stator manufacturing method of the present embodiment, it is possible to contribute to a reduction in insulation failure of the stator 10. This is because the segment Sg is formed by bending the rectangular conductor D to which the insulation coating Ic is applied, the separation coating Sc is peeled off at the tip of the segment Sg, and the segment Sg is formed on the stator core 20. The end of the segment Sg is engaged with the tip of the segment Sg and the groove 112 (groove 122) of the coil twisting jig 110, and the coil twisting jig 110 is rotated in the circumferential direction of the stator core 20. The stator 10 is formed by forming the part, welding the end of the segment Sg, and insulating the end of the welded segment Sg by powder coating.

  At this time, the tooth portion 118 (tooth portion 128) of the coil twisting jig 110 has a slope 116 (slope 126) on the support front surface 114 located on the traveling direction side with respect to the rotation direction of the coil twisting jig 110. In the state where the groove 112 (groove 122) and the tip of the segment Sg are engaged, the shoulder Sgk and the tooth corresponding to the tip of the non-peeling portion provided from the peeling portion Sgi formed at the tip of the segment Sg In the state where the support surface 114 and the shoulder Sgk are not in contact with each other by rotating the coil twisting jig 110 by the inclined surface 116 (inclined surface 126) between the support surface 114 of the portion 118 (tooth portion 128). Twist formation. By doing so, it is possible to reduce insulation defects.

  FIG. 14 is a cross-sectional view of the lead portion Sga before twist forming. In addition, as for peeling part Sgi of FIG. 14, the front-end | tip of segment Sg peels in the predetermined range by peeling process. At this time, the base material portion of the flat conductor D is also cut together with the insulating coating Ic. Therefore, there is a step like the shoulder Sgk, and the insulating coating Ic is disposed around the step. FIG. 15 is a side view showing a state where the tip of a segment prepared for comparison is inserted into the coil twisting jig 110. FIG. 16 is a side view showing a state where the tip of the segment is twisted by the coil twisting jig 110. Unlike the first annular member 111 or the second annular member 121 of the present embodiment, the annular member 211 prepared for comparison does not include a notch in the tooth portion 218.

  By twisting the lead portion Sga as shown in FIG. 16 with the annular member 211, it is twisted into a crank shape as shown in FIG. At this time, a load is applied to the tip of the lead portion Sga. FIG. 17 is a sectional view showing the left side of the tip of the lead portion. FIG. 18 is a sectional view showing the right side of the tip of the lead portion. It has been found that there is a case where the tip of the lead portion Sga shown in FIG. 14 is deformed as shown in FIGS. The peeling portion Sgi on the side shown in FIG. 17 is vague with the boundary portion with the shoulder Sgk rising, and it can be seen that the tip portion of the insulating coating Ic is peeling off. On the other hand, as shown in FIG. 18 on the right side, part of the insulation coating Ic is crushed.

  This is considered to be because the pressurizing force F2 at the time of twist formation is applied to the first action point P1 shown in FIG. The lead portion Sga is made somewhat loose with respect to the annular member 211 in consideration of the insertability. For this reason, both the proximity force F1 and the applied pressure F2 that are generated when the annular member 211 approaches the stator 10 are applied, and the force is centered on the tip of the separation portion Sgi, the first action point P1, and the second action point P2. It is thought to act. As a result, it is presumed that the shape of the shoulder Sgk is crushed by the applied pressure F2, the deformed portion A1 as shown in FIG. 17 is formed, and the peeled portion A2 is formed. If the powder coating is performed in the “coil end portion insulation treatment” step of S10 in such a state with the lead portion Sga being in such a state, although insulation can be ensured during the insulation treatment, insulation failure may occur during use. Actually, as a result of the thermal cycle test of the stator 10, it has been confirmed that a crack has occurred with the base of the peeled portion A2 shown in FIG.

  For this reason, in the 1st annular member 111 and the 2nd annular member 121 of this embodiment, slope 116 and slope 126 are formed in tooth part 118 and tooth part 128, respectively. As shown in FIG. 11, when the lead portion Sga is inserted, the slope 116 and the slope 126 are formed from the portion above the root of the peeling portion Sgi. With such a configuration, the first action point P1 is provided in the peeling portion Sgi, and the shoulder portion Sgk and the insulating coating Ic can be prevented from being crushed. As a result, since it has been confirmed that no peeling occurs as in the peeling portion A2, it is considered that it can contribute to the extension of the life of the stator 10.

  In order to further reduce the size of the stator 10, further shortening of the coil end is required. However, if the twist angle of the lead portion Sga is deep and the push-in is deepened, the deformation as shown in FIGS. It is expected that the rate of occurrence increases and the amount of deformation increases. Further, when the space factor of the stator 10 is improved and the amount of current flowing through the segment coil SC is increased, it is required to increase the cross-sectional area of the rectangular conductor D. It is considered that a portion such as the peeled portion A2 is likely to occur. However, with the configuration of the present embodiment, the first annular member 111 and the second annular member 121 have a high effect of suppressing deformation and peeling of the shoulder portion Sgk and the insulation coating Ic in the lead portion Sga. Even when higher power and higher output are required, it can contribute to longer life.

  Further, when the state shown in FIG. 10 is changed to the state shown in FIG. 11, that is, when the lead portion Sga is inserted into the groove portion 112 of the first annular member 111, the inclined surface 116 serves as a guide. For this reason, the insertion of the lead portion Sga into the groove portion 112 is performed smoothly, and it is difficult for problems such as the lead portion Sga to be deformed due to interference when the first annular member 111 is inserted into the groove portion 112. Further, the lead portion Sga can be inserted into the groove 112 of the first annular member 111 even if the shape accuracy of the lead portion Sga or the position accuracy of the tip is not high. As a result, it can be expected that the manufacturing cost of the stator 10 can be reduced.

  Although the invention has been described according to the present embodiment, the invention is not limited to the embodiment, and by appropriately changing a part of the configuration without departing from the spirit of the invention. It can also be implemented. For example, the material of the stator 10 exemplified in the present embodiment, the number of slots, and the like are not prevented from being appropriately changed based on the design concept. Further, a plurality of the first annular members 111 and the second annular members 121 are provided so as not to prevent simultaneous processing. The slope 116 corresponding to the notch provided in the tooth 118 of the coil twisting jig 110 is preferably a slope having a predetermined angle in order to function as the tip guide of the segment Sg. It does not prevent processing into an R shape or another shape in order to avoid interference.

DESCRIPTION OF SYMBOLS 10 Stator 11 Teeth 12 Slot 20 Stator core 100 Molding apparatus 110 Coil twisting jig 111 1st annular member 112, 122 Groove part 113 Bottom part 114 Support front surface 115 Support rear surface 116, 126 Slope 118, 128 Tooth part 121 2nd annular member Ic Insulation coating P1 First action point P2 Second action point SC Segment coil Sg Segment Sga Lead part Sgb In-slot conductor part Sgc Anti-lead part Sge Crank part Sgf Welding part Sgi Peeling part Sgk Shoulder part

Claims (5)

A rectangular conductor with insulating coating is bent to form a substantially U-shaped segment, the insulating coating at the tip of the segment is peeled to form a peeling portion, and the segment is inserted into a stator core, Engage the tip of the segment with the groove formed between the teeth of the coil twisting jig, rotate the coil twisting jig in the circumferential direction of the stator core, and mold the end of the segment In the stator manufacturing method of forming the stator by welding the end portions of the segments and insulating the end portions of the welded segments by powder coating,
The tooth portion of the coil twisting jig has a notch portion on the support front surface facing the side of the segment inserted into the groove and positioned on the traveling direction side with respect to the rotation direction of the coil twisting jig. The tip of the non-peeling portion and the tooth portion where the insulating coating is left from the peeling portion formed at the tip of the segment with the groove and the tip of the segment engaged. There is a gap between the notch and
Rotating the coil twisting jig to form a twist in a state where the support front surface and the tip of the non-peeling portion are not in contact with each other;
The stator manufacturing method characterized by these. In the stator manufacturing method according to claim 1,
The notch portion formed in the tooth portion of the coil twisting jig is formed of an oblique side cut obliquely with respect to the support front surface;
The stator manufacturing method characterized by these. An annular member having a groove portion and a tooth portion alternately engaged with the tip end of the segment inserted into the stator core with the insulating coating on the tip end peeled, and rotatably provided in the circumferential direction of the stator core. In a coil twisting jig having
A plurality of the groove portions are provided in the circumferential direction, and a plurality of the tips of the segments can be twisted simultaneously,
The tooth portion has a notch portion on a support front surface facing the side of the segment inserted in the groove portion and positioned on the traveling direction side with respect to the rotation direction of the annular member, and the groove portion and the In a state where the tip of the segment is engaged, there is a gap between the tip of the non-peeling portion where the insulating coating is provided from the peeling portion formed at the tip of the segment and the support front surface of the tooth portion. What you can do,
A coil twisting jig characterized by In the coil twisting jig according to claim 3,
The notch portion formed in the tooth portion of the coil twisting jig is formed of an oblique side cut obliquely with respect to the support front surface;
A coil twisting jig characterized by A stator manufacturing apparatus comprising the coil twisting jig according to claim 3.

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