Forming device for coil of rotary electric machine, forming method for coil of rotary electric machine, coil of rotary electric machine, manufacturing method for stator of rotary electric machine, and rotary electric machine

Abstract

A forming device (99) for a coil of a rotary electric machine forms the coil from a straight coil conductor, said coil having: a top part (13) that is a triangular vertex; a crank part (12) that is positioned at the top part (13); and shoulder parts (15a, 15b) that connect oblique side parts (14a, 14b) and straight parts (16a, 16b). The forming device (99) comprises: a forming die (41) that is a die for the crank part (12), the top part (13), and the shoulder parts (15a, 15b) of the coil (10) of the rotary electric machine (100); a crank part forming punch (42) for forming the crank part (12); a top part forming punch (43) for forming the top part (13); shoulder part forming rollers (44a, 44b) for preliminarily forming the shoulder parts (15a, 15b); and shoulder part forming punches (45a, 45b) for finally forming the shoulder parts (15a, 15b).

Description

Coil forming device for rotating electric machine, coil forming method for rotating electric machine, coil for rotating electric machine, method for manufacturing stator for rotating electric machine, and rotating electric machine

[0001] The present disclosure relates to a coil forming device for a rotating electric machine, a coil forming method for a rotating electric machine, a method for manufacturing a coil for a rotating electric machine, a stator for a rotating electric machine, and a rotating electric machine.

[0002] Industrial motors such as those installed in processing machines are required to be compact and have high output due to the limited mounting space, and some motors use rectangular coils to improve the coil space factor.

[0003] A method for forming segment coils for rotating electrical machines is disclosed in which the coil is processed in the order of two-dimensional crank forming → top forming → shoulder forming (for example, Patent Document 1). Also disclosed is a method for forming segment coils for rotating electrical machines in which the coil is processed in the order of two-dimensional crank forming → top forming → shoulder forming, and in which preforming and main forming are performed using two rollers to minimize damage to the coil during shoulder forming (for example, Patent Document 2).

[0004] Japanese Patent No. 3894004 Japanese Patent Application Laid-Open No. 2020-61900

[0005] However, in the method of Patent Document 1, the forming angle of the shoulder is deep, which causes damage to the coil, and in the method of Patent Document 2, the forming force is weak because the forming is performed using rollers, and the coil springback causes a shallow forming angle and a V-shaped coil shape.

[0006] The present disclosure discloses technology for solving the above-mentioned problems, and aims to provide a coil forming device for a rotating electric machine that can deepen the forming angle of the shoulder portion and suppress damage to the coil, a coil forming method for a rotating electric machine, a method for manufacturing a coil for a rotating electric machine, a stator for a rotating electric machine, and a rotating electric machine.

[0007] The coil forming device for a rotating electric machine disclosed herein is a coil forming device for a rotating electric machine that forms, from a straight coil conductor, a coil having an apex that is the vertex of a triangle, a crank portion located at the apex of the triangle, and a shoulder portion that connects the hypotenuse portion and the straight portion, and is equipped with a forming die that serves as a die for the crank portion, the apex, and the shoulder portion of the coil of the rotating electric machine, a crank portion forming punch that forms the crank portion, a apex forming punch that forms the apex, a shoulder forming roller that pre-forms the shoulder portion, and a shoulder forming punch that actually forms the shoulder portion. The method for forming a coil of a rotating electric machine disclosed herein includes the following steps: a crank forming step in which, using a forming device for a coil of a rotating electric machine, a straight coil is placed on the forming die and pressed with the crank portion forming punch to form the crank portion of the coil; a top forming step in which, using the forming die and the top forming punch that forms the top portion, the coil whose crank portion has been formed in the crank forming step is pressed down with the top forming punch to form the top of the coil; a shoulder preforming step in which a shoulder forming roller that preforms the shoulder of the coil is pressed down to bend the coil so that it conforms to the side of the forming die; and a shoulder final forming step in which, using the forming die and the shoulder forming punch that final forms the shoulder, the coil preformed in the shoulder preforming step is pressed down to final form the shoulder. The coil of the rotating electric machine disclosed herein is a coil of the rotating electric machine having a straight portion, an apex that is the vertex of a triangle, a crank portion located at the apex of the triangle, and a shoulder portion that connects the straight portion to hypotenuse portions connected to both sides of the apex, and at least one side of the shoulder portion has an indentation formed at a predetermined distance from the apex of the shoulder portion.The method for manufacturing a stator for a rotating electric machine according to the present disclosure includes a squirrel-cage coil forming step of forming a squirrel-cage coil by arranging rotating electric coils formed using a rotating electric coil forming device or a rotating electric coil forming method in an annular shape, a coil inserting step of sequentially inserting straight portions of the coils into slots of a stator core of the rotating electric machine, a twist forming step of twisting lower portions of the straight portions of the coils inserted into the slots of the stator core, and an electrical connecting step of electrically connecting peeled portions of the lower portions of the straight portions of the coils to form a specified winding connection. The rotating electric machine according to the present disclosure includes a stator for the rotating electric machine having a rotating electric coil, and a rotor disposed inside the stator of the rotating electric machine.

[0008] The coil forming apparatus for a rotating electric machine disclosed herein provides a coil forming apparatus for a rotating electric machine that can deepen the forming angle of the shoulder portion and suppress damage to the coil.The coil forming method for a rotating electric machine disclosed herein provides a coil forming method for a rotating electric machine that can deepen the forming angle of the shoulder portion and suppress damage to the coil.The coil for a rotating electric machine disclosed herein provides a coil for a rotating electric machine that can deepen the forming angle of the shoulder portion and suppress damage to the coil.The manufacturing method for a stator for a rotating electric machine disclosed herein provides a stator manufacturing method for a rotating electric machine that can deepen the forming angle of the shoulder portion and suppress damage to the coil.The rotating electric machine disclosed herein provides a rotating electric machine that can deepen the forming angle of the shoulder portion and suppress damage to the coil.

[0009] 2A is a perspective view of a segment coil of a rotating electric machine according to embodiment 1. FIG. 2B is a side view of a segment coil of a rotating electric machine according to embodiment 1. FIG. 2B is a perspective view of a coil group of a rotating electric machine according to embodiment 1. FIG. 2C is a top view of a stator core of a rotating electric machine according to embodiment 1. FIG. 2D is a perspective view of a stator after coil insertion of a rotating electric machine according to embodiment 1. FIG. 2E is a perspective view of a stator after wire connection of a rotating electric machine according to embodiment 1. FIG. 2F is a schematic view of a molding device for a segment coil of a rotating electric machine according to embodiment 1. FIG. 2G is a schematic view of a forming device for a segment coil of a rotating electric machine according to embodiment 1. FIG. 2H is a schematic view of a forming device for a segment coil of a rotating electric machine according to embodiment 1. 22A is an explanatory diagram of indentations on a segment coil according to embodiment 1. FIG. 22B is an explanatory diagram of indentations on a segment coil according to embodiment 1. FIG. 23A is an explanatory diagram of a comparative example of indentations on a segment coil according to embodiment 1. FIG. 23B is an explanatory diagram of a comparative example of indentations on a segment coil according to embodiment 1. FIG. 25A is a top view of a tortoiseshell coil according to embodiment 3. FIG. 25B is a bottom view of a tortoiseshell coil according to embodiment 3. FIG. 25B is a side view of a tortoiseshell coil according to embodiment 3. FIG. 22A is an explanatory diagram of an indentation on a segment coil according to embodiment 1. FIG. 22B is an explanatory diagram of an indentation on a segment coil according to embodiment 1. FIG. 23A is an explanatory diagram of a comparative example of indentations on a segment coil according to embodiment 1. FIG. 23B is an explanatory diagram of a comparative example of indentations on a segment coil according to embodiment 1. FIG. 25A is a top view of a tortoiseshell coil according to embodiment 3. FIG. 25B is a bottom view of a tortoiseshell coil according to embodiment 3. FIG. 25B is a side view of a tortoiseshell coil according to embodiment 3. FIG. 22B is an explanatory diagram of an indentation on a segment coil according to embodiment 1.10 is an explanatory diagram of a process for forming a tortoiseshell coil according to embodiment 3. FIG. 11 is an explanatory diagram of a process for forming a tortoiseshell coil according to embodiment 3. FIG.

[0010] Embodiment 1. Embodiment 1 relates to a coil forming device for a rotating electric machine that forms a U-shaped coil from a straight coil conductor, the coil having an apex that is the vertex of a triangle, a crank portion located at the apex of the triangle, and a shoulder portion connecting the hypotenuse portion and the straight portion, and that includes a forming die that forms the crank portion, apex, and shoulder portion of the coil for a rotating electric machine, a crank portion forming punch that forms the crank portion, a apex forming punch that forms the apex, a shoulder portion forming roller that preforms the shoulder portion, and a shoulder portion forming punch that finally forms the shoulder portion. Furthermore, Embodiment 1 relates to a coil forming method for a rotating electric machine that includes a crank forming step, a apex forming step, a shoulder preforming step, and a shoulder final forming step.

[0011] The coil molding device for a rotating electric machine according to embodiment 1 will be described below with reference to Figure 1, which is a perspective view of a segment coil, Figure 2A, which is a top view of a segment coil, Figure 2B, which is a side view, Figure 3, which is a perspective view of a group of coils, Figure 4, which is a top view of a stator core, Figure 5, which is a perspective view of the stator after the coil has been inserted, Figure 6, which is a perspective view of the stator after wiring, Figure 7, which is a schematic diagram of a molding device for a segment coil, Figure 8, which is an explanatory diagram of a straight coil arranged in a molding die, Figure 9, which is a schematic diagram of a molding device in a crank-shaped state, Figure 10, which is an explanatory diagram of a segment coil in a crank-shaped state, Figure 11, which is a schematic diagram of a molding device in a top-shaped state, Figure 12, which is an explanatory diagram of a segment coil in a top-shaped state, Figure 13, which is a schematic diagram of a molding device in a shoulder-preformed state, Figure 14, which is an explanatory diagram of a segment coil in a shoulder-preformed state, Figure 15, which is a schematic diagram of a molding device in a shoulder-maintained state, Figures 22A and 22B, which are explanatory diagrams of indentations on a segment coil, and Figures 23A and 23B, which are explanatory diagrams of comparative examples of indentations on a segment coil. A method for forming coils for a rotating electric machine will be described with reference to Fig. 16, which is a flowchart of a method for forming segment coils, and a method for manufacturing a stator for a rotating electric machine will be described with reference to Fig. 17, which is a flowchart of a method for manufacturing a stator. Furthermore, a rotating electric machine will be described with reference to Fig. 18, which is a schematic diagram. In each figure, the same or corresponding parts are designated by the same reference numerals.

[0012] In the first embodiment, the steps taken to transform a formed segment coil into a stator for a rotating electric machine are sequentially explained. In the case of a general explanation, the names are simplified and no reference numerals are attached. For example, in a general explanation of a segment coil, it is simply referred to as a "coil." First, the structure and features of the segment coil for a rotating electric machine in the first embodiment are explained based on Figures 1 and 2.

[0013] Figure 1 is a perspective view showing a segment coil 10 formed by a forming device 99, which will be described later, as one embodiment. Figure 2A is a top view of the segment coil 10, and Figure 2B is a side view. The segment coil 10 forms the winding of the stator of a rotating electric machine. The segment coil 10 is a coil with a rectangular cross section, and is composed of a conductor made of copper and aluminum and an insulator made of a resin material. To prevent short circuits even when the segment coils 10 come into contact with each other, the conductor of the segment coil 10 is covered with an insulator.

[0014] The segment coil 10 is formed by a forming device 99 into a U-shape having an S-shaped crank portion 12, a triangular apex 13, and shoulders 15a and 15b. The shoulders 15a and 15b connect the oblique sides 14a and 14b to the straight portions 16a and 16b. The oblique sides 14a and 14b are connected to both sides of the triangular apex 12. The ends of the straight portions 16a and 16b have stripped portions 17a and 17b where the insulation has been scraped off to expose the coil conductor. The stripped portions 17a and 17b may be formed before or after forming by the forming device 99.

[0015] Next, a cage coil group 19 formed by combining multiple segment coils 10 will be described with reference to FIG. 3. FIG. 3 is a perspective view showing a cage coil group 19 in which multiple segment coils 10 are arranged in a ring shape to form a cage. The crank portion 12 and the top portion 13 are shaped to minimize contact with each other when the segment coils 10 are arranged in a ring shape. A four-turn winding pattern is shown here. Two types of segment coils are configured: one type for the first and second turns and another type for the third and fourth turns. The first and second turns of the segment coil and the third and fourth turns of the segment coil are different in that the straight portions 16a and 16b of each segment coil 10 are shaped to be positioned in predetermined positions in the slots 24 of the stator core 20, but they basically have the shapes shown in FIGS. 1 and 2.

[0016] Next, the stator core 20 of the rotating electric machine will be described with reference to FIG. 4. FIG. 4 shows a top view of the stator core 20 of the rotating electric machine. A partially enlarged view is also shown on the right side. The stator core 20 is composed of an arc-shaped yoke 21, teeth 22 extending radially inward from the yoke 21, and shoes 23 disposed at the tips of the teeth 22. The circumferential side of the stator core 20 is sandwiched between the teeth 22, the radially outer side is sandwiched between the yoke 21, and the space sandwiched between the openings of the shoes 23 facing each other in the circumferential direction is the slot 24. The straight portions 16a and 16b of the segment coil 10 are housed in the slot 24. The slot 24 has a nearly rectangular shape, and a coil with a rectangular cross section can achieve a better space factor than a coil with a circular cross section.

[0017] Next, the insertion of the segment coils 10 into the stator core 20 will be described with reference to Figure 5. Figure 5 shows the state in which a cage coil group 19 (described in Figure 3) in which multiple segment coils 10 are arranged in an annular shape has been inserted into the stator core 20. This state is referred to as the stator 30 after coil insertion before wiring. The tortoiseshell-shaped coils that have been common until now have to be inserted from the radially inside of the stator core 20, and inserting them while avoiding the shoes 23 has been very difficult. Furthermore, when tortoiseshell-shaped coils are inserted one by one from the radially inside, the subsequently inserted coils have to be inserted while avoiding the coil ends of the previously inserted coils, which is also very difficult.

[0018] With the segment coil 10 of embodiment 1, the cage coil group 19 can be inserted in the axial direction of the stator core 20 from the direction of the peeled-off portions 17a and 17b. This reduces the difficulty of arranging the coil in the stator core 20 with the segment coil 10 of embodiment 1. At this time, an insulator made of paper or resin material may be arranged inside the slots 24 of the stator core 20 to insulate the segment coil 10 from the stator core 20.

[0019] Next, the winding connection of the stator of a rotating electric machine will be described with reference to Figure 6. Figure 6 shows the state of a stator 31 of a rotating electric machine according to the first embodiment. A group of cage coils 19 arranged in a ring shape are inserted into slots 24 of a stator core 20, and the stripped portions 17a, 17b of the straight portions 16a, 16b of the segment coils 10 are twist-formed. After twist-forming, the stripped portions 17a, 17b of each segment coil 10 are electrically connected to form a predetermined winding connection. The electrical connection is achieved by TIG (tungsten inert gas) welding, laser welding, or brazing.

[0020] The molding device 99 for the segment coil 10 in the first embodiment will be described with reference to Fig. 7, which is a schematic diagram of the molding device 99. As shown in Fig. 7, the left-right direction of the molding device 99 will be described as the X direction, the front-rear direction as the Y direction, and the up-down direction as the Z direction. This also applies to the subsequent descriptions of the drawings.

[0021] The forming device 99 is composed of a forming die 41, a crank portion forming punch 42, a top portion forming punch 43, shoulder portion forming rollers 44a and 44b, and shoulder portion forming punches 45a and 45b. The forming die 41 is fixed and serves as a die for the crank portion 12, the top portion 13, and the shoulder portions 15a and 15b. The crank portion forming punch 42 operates in the Y direction to form the crank portion 12. The top portion forming punch 43 operates in the Z direction to form the top portion 13. The shoulder portion forming roller 44a operates in the Z direction to preform the shoulder portion 15a. The shoulder portion forming roller 44b operates in the Z direction to preform the shoulder portion 15b. The shoulder portion forming punch 45a operates in a direction that bisects the forming angle of the shoulders 15a and 15b (forming them at the same angle) and finally forms the shoulder portion 15a. The shoulder forming punch 45b operates in a direction that bisects the forming angle of the shoulders 15a, 15b (forming them at the same angle) to finally form the shoulder 15b.

[0022] Next, a method for forming the segment coil 10 will be described in order with reference to Figures 8 to 15. As shown in Figure 8, a linear coil (referred to as a straight coil 10a) cut to a predetermined length is placed in a forming die 41. At this time, the straight coil 10a is placed so that one side of the straight coil 10a contacts the vertex 41t of the forming die 41. Possible methods for placing the straight coil 10a include using a robot hand from the Y direction, or using a pneumatic device to push the straight coil 10a from the Z direction.

[0023] The forming die 41 is fixed, and the crank portion forming punch 42 moves in the Y direction, pressing the straight coil 10a against the crank portion 41a of the forming die 41 toward the positive side of the Y direction. Figure 9 shows the state in which the crank portion forming punch 42 is pressed against the forming die 41. Figure 10 shows a schematic diagram of the coil at this time. The coil with the crank portion formed is referred to as segment coil 10b.

[0024] The actuator that operates the crank portion forming punch 42 controls the positioning by driving a servo motor with a ball screw. Possible actuators include pneumatic cylinders, hydraulic cylinders, and servo motors. Controlling the actuator by position allows the coil to be formed at the same depth every time, reducing variations in the shape of the crank portion 12. However, in this case, a force greater than expected may be applied, which could damage the coil, so the bottom dead center position must be adjusted. Controlling the actuator by pressure also prevents a force greater than expected from being applied, minimizing damage to the coil. However, in this case, variations in the hardness of the coil may result in variations in the shape of the crank portion 12.

[0025] The top forming punch 43 operates in the Z direction, pressing the segment coil 10b downward in the Z direction onto the top forming portion 41b of the forming die 41. Figure 11 shows the pressed state of the segment coil 10b. Figure 12 also shows a schematic diagram of the coil in this pressed state. The coil with the top formed is designated segment coil 10c. At this time, the crank portion forming punch 42 is operated while being pressed against the forming die 41 via the coil, or while being slightly loosened from the forming position. By maintaining the previously formed area in this way, the crank portion 12 is properly formed in both directions. (For example, if the crank portion forming punch 42 is opened while the top forming punch 43 is used to form the crank portion 12, the shape of the crank portion 12 will be distorted.)

[0026] The crank portion forming punch 42 operates the top portion forming punch 43 at the forming position, so the top portion forming punch 43 has a shape resembling a baked yatsuhashi (a confectionery shaped like a koto) that resembles the crank portion 12. The actuator that operates the top portion forming punch 43 may be a pneumatic cylinder, a hydraulic cylinder, a servo motor, or the like.

[0027] The shoulder forming rollers 44a and 44b can move in the Z direction. The shoulder forming rollers 44a and 44b pass downward in the Z direction at a position slightly away from the side surface 41d of the forming die 41, and press and bend the segment coil 10c along the side surface 41d of the forming die 41, using the shoulder forming portion 41c of the forming die 41 as a fulcrum. The shoulder forming rollers 44a and 44b have grooves 46a and 46b that are slightly larger than the width of the coil, allowing the coil to be preformed while preventing it from falling off. Figure 13 shows the state in which the shoulders 15a and 15b have been preformed. Figure 14 shows a schematic diagram of the coil with the shoulders 15a and 15b preformed. The coil with the shoulders 15a and 15b preformed is referred to as segment coil 10d.

[0028] In preforming by the shoulder forming rollers 44a and 44b, the crank forming punch 42 and the top forming punch 43 are pressed against the forming die 41 via coils. The actuators that operate the shoulder forming rollers 44a and 44b may be pneumatic cylinders, hydraulic cylinders, servo motors, etc. After preforming by the shoulder forming rollers 44a and 44b, the shoulder forming rollers 44a and 44b may remain lowered or may be raised and returned to their original positions.

[0029] The shoulder-forming punch 45a and the shoulder-forming punch 45b operate in a direction that bisects the forming angle of the shoulders 15a and 15b (forming the same angle), and press the segment coil 10d, which has preformed the shoulders 15a and 15b, against the shoulder-forming portion 41c of the forming die 41. Figure 15 shows the forming device 99 in this state after the shoulders have been fully formed. Note that for ease of understanding, the crank-forming punch 42 is not shown in Figure 15, but in reality it is pressing against the segment coil 10d. Through this series of steps, the straight coil 10a is formed into the segment coil 10 shown in Figure 1.

[0030] By operating the shoulder forming punches 45a and 45b in a direction that bisects the forming angle of the shoulders 15a and 15b (forming the same angle), the forming angle between the shoulder forming punches 45a and 45b can be minimized. As a result, forming can be performed with minimal damage to the coil. However, forming is also possible if the forming direction is from the Z direction or the Y direction.

[0031] Since the shoulder-forming punches 45a, 45b are operated while the crank-forming punch 42 is in the forming position, the tip portions of the shoulder-forming punches 45a, 45b are formed in a thin plate shape to avoid interference between the crank-forming punch 42 and the forming die 41. Even in the actual forming of the shoulders 15a, 15b by the shoulder-forming punch 45a and the shoulder-forming punch 45b, the crank-forming punch 42 and the top-forming punch 43 are pressed against the forming die 41 via the coil.

[0032] The actuators that operate the shoulder forming punches 45a, 45b may be pneumatic cylinders, hydraulic cylinders, servo motors, etc. Note that indentations are formed on both sides of each of the shoulders 15a, 15b of the segment coil 10 at a predetermined distance from the apex of each shoulder 15a, 15b. The predetermined distances from the apex of the shoulder 15a or 15b to the indentations on both sides may be different. The depths of the indentations formed on both sides of the shoulders 15a, 15b are the same, but may also be different. Furthermore, when the indentation depths are the same, the shoulder forming punches 45a, 45b have a pressing force that forms indentations of the same depth on both sides of the shoulders of the segment coil 10.

[0033] The indentations on the segment coil will be explained based on the explanatory diagrams of Figures 22A and 22B. In the figures, the indentations are labeled "ID." Figure 22A shows the shoulder-forming of a segment coil 10, which has been shoulder-formed using the shoulder-forming punch 45a of the forming device 99. Figure 22B is an enlarged view of the indentations. Because the shoulder-forming punches 45a and 45b operate in a direction that bisects the forming angle of the shoulders 15a and 15b (forming the same angle), an equal load is applied, and indentations are formed on both sides of the shoulders 15a and 15b of the segment coil 10 at a predetermined distance from the apex of each shoulder 15a and 15b. A comparative example of indentations on a segment coil will be explained using Figures 23A and 23B. Figure 23A shows the case where the shoulder-forming punch 45a operates in a direction that does not bisect the forming angle of the shoulder 15a (vertically downward in the figure). In this case, the indentations are only formed on one side, as shown in Figure 23B, rather than on both sides.

[0034] This completes the forming of the segment coil 10, and the shoulder forming punches 45a, 45b are raised in the Z direction in order to release the coil. The shoulder forming rollers 44a, 44b, then the top forming punch 43, and finally the crank forming punch 42 are raised, and the last formed segment coil 10 is removed, completing the forming by the forming device 99.

[0035] The above-described method for forming the segment coil 10 is summarized based on the flowchart shown in FIG. 16. The coil forming method for a rotating electric machine according to the first embodiment includes the following steps 01 (S01) to 04 (S04): forming die 41 for forming the crank portion 12, apex 13, and shoulders 15a and 15b of the coil; crank portion-forming punch 42 for forming the crank portion 12; apex-forming punch 43 for forming the apex 13; shoulder-forming rollers 44a and 44b for preforming the shoulders 15a and 15b; and shoulder-forming punches 45a and 45b for forming the shoulders 15a and 15b. In the crank forming step of step 01 (S01), a straight coil is placed on the forming die 41 using the forming die 41 and the crank portion-forming punch 42, and the crank portion 12 of the coil is formed by pressing the straight coil against the forming die 41 with the crank portion-forming punch 42. In the top forming step of step 02 (S02), a forming die 41 and a top forming punch 43 that forms the top 13 are used to press down the coil from which the crank portion 12 has been formed in the crank forming step with the top forming punch 43 to form the top 13 of the coil. In the shoulder preforming step of step 03 (S03), shoulder forming rollers 44a and 44b that preform shoulders 15a and 15b of the coil are pressed down to bend the coil to fit the side of the forming die 41. In the shoulder final forming step of step 04 (S04), the forming die 41 and shoulder forming punches 45a and 45b that final form the shoulders 15a and 15b are used to press down the coil preformed in the shoulder preforming step to final form the shoulders 15a and 15b.

[0036] Here, we will explain the features of the coil forming method for a rotating electric machine according to the first embodiment. The reason for separating the preliminary forming and the main forming in the shoulder forming process is as follows. If the shoulder forming punches 45a, 45b were used to form the shoulders 15a, 15b from the beginning, without using the shoulder forming rollers 44a, 44b, the forming angle would be deep when the segment coil 10c was bent around the shoulder forming portion 41c of the forming die 41 as a fulcrum. Since the shoulders 15a, 15b are formed while rubbing against the coil with the thin plates 47a, 47b at the tips of the shoulder forming punches 45a, 45b, damage to the coil (such as peeling of the insulating coating and indentations on the coil) occurs.

[0037] The shoulder forming rollers 44a, 44b form the coil while rotating, so no rubbing force is applied to the coil, and damage to the coil can be reduced even if the forming angle is deep. Furthermore, if the shoulders are formed using only the shoulder forming rollers 44a, 44b, the load cannot be concentrated on the shoulders 15a, 15b, which are the fulcrum for forming, so the forming force is weak and the coil springs back, resulting in a shallow forming angle and a V-shaped coil shape.

[0038] Therefore, in the coil forming method for a rotating electric machine according to the first embodiment, compared to forming using a forming punch without shoulder preforming using rollers, the forming angle is shallower due to the prior forming using rollers, which can suppress damage to the coil (peeling off of the insulating coating, indentations on the coil) during actual shoulder forming using shoulder forming punches 45 a, 45 b. Also, compared to forming using rollers again after shoulder preforming using rollers, the forming angle of the shoulder can be deeper because the forming using the forming punches is performed.

[0039] Next, a manufacturing method of the stator 31 of the rotating electric machine according to the first embodiment will be described with reference to the flowchart of FIG. 17 . The manufacturing method of the stator of the rotating electric machine according to the first embodiment uses a rotating electric machine coil formed using a rotating electric machine coil forming device or a rotating electric machine coil forming method, and comprises steps 11 (S11) to 14 (S14). In step 11 (S11), a squirrel-cage coil forming step, the rotating electric machine coils are arranged in an annular shape to form the squirrel-cage coil 19. In step 12 (S12), a coil insertion step, the straight portions 16 a and 16 b of the coil are sequentially inserted into the slots 24 of the stator core 20 of the rotating electric machine. In step 13 (S13), a twist forming step, the lower portions of the straight portions 16 a and 16 b of the segment coil 10 inserted into the slots 24 of the stator core 20 are twist formed. In the electrical connection step of step 14 (S14), the stripped portions 17a, 17b at the bottom of the straight portions 16a, 16b of the segment coil 10 are electrically connected so as to form a specified winding connection.

[0040] Next, a rotating electric machine 100 configured using the rotating electric machine stator 31 will be described with reference to Fig. 18. The rotating electric machine 100 includes the rotating electric machine stator 31 manufactured by the method for manufacturing a rotating electric machine stator described above, and a rotor 32 arranged inside the rotating electric machine stator 31.

[0041] In the first embodiment, a coil having a rectangular cross section has been described. However, the segment coil 10 can also be processed using the configuration of the first embodiment for a coil having a circular cross section.

[0042] As described above, the rotating electric machine coil forming apparatus of the first embodiment can provide a rotating electric machine coil forming apparatus that can deepen the forming angle of the shoulder portion and suppress damage to the coil. Also, the rotating electric machine coil forming method of the first embodiment can provide a rotating electric machine coil forming method that can deepen the forming angle of the shoulder portion and suppress damage to the coil. Also, the rotating electric machine stator manufacturing method of the first embodiment can provide a rotating electric machine stator that can deepen the forming angle of the shoulder portion and suppress damage to the coil.

[0043] Second Embodiment A coil forming apparatus for a rotating electrical machine according to a second embodiment is configured so that the shoulder forming rotor and the shoulder forming punch are driven by the same actuator.

[0044] The coil forming apparatus for a rotating electric machine according to the second embodiment will be described, focusing on the differences from the first embodiment, based on Fig. 19, which is a front view of the forming apparatus for a segment coil of a rotating electric machine, Fig. 20, which is a front view of the forming apparatus in a state where the shoulder portion has been preliminarily formed, and Fig. 21, which is a front view of the forming apparatus in a state where the shoulder portion has been fully formed. In the drawings of the second embodiment, parts that are the same as or equivalent to those in the first embodiment are given the same reference numerals. To distinguish from the first embodiment, the forming apparatus is referred to as a forming apparatus 199, shoulder forming rollers 144a, 144b, and shoulder forming punches 145a, 145b.

[0045] First, the configuration of a coil forming apparatus 199 for a rotating electric machine according to the second embodiment will be described with reference to FIG. 19 . In the second embodiment, the process up to the top forming is the same as in the first embodiment, but the shoulder preforming and main shoulder forming are different. The forming apparatus 199 is composed of a forming die 41, a crank portion forming punch 42, a top forming punch 43, shoulder forming rollers 144a and 144b, and shoulder forming punches 145a and 145b. The forming apparatus 199 according to the second embodiment has the same forming die 41, crank portion forming punch 42, and top forming punch 43 as in the first embodiment, and is further characterized in that the shoulder forming roller 144a and shoulder forming punch 145a, and the shoulder forming roller 144b and shoulder forming punch 145b are each operated by a single actuator.

[0046] In Figure 19, shoulder forming rollers 144a and 144b are fixed to sliders 51a and 51b via blocks 52a and 52b. The sliders 51a and 51b have grooves cut in a direction that bisects the forming angle of the shoulders 15a and 15b, and shoulder forming punches 145a and 145b are housed in these grooves. The housed shoulder forming punches 145a and 145b are tapered on the side opposite the punch, and the taper contacts the fixed cams 50a and 50b. The shoulder forming punches 145a and 145b are pressed toward the cams 50a and 50b by springs (not shown). The cams 50a and 50b are shaped so that the lower side in the Z direction is wider than the upper side. That is, the more the sliders 51a, 51b move downward in the Z direction, the more the shoulder forming punches 145a, 145b are pushed in a direction approaching the segment coil 10 on the opposite side of the cams 50a, 50b.

[0047] Next, we will explain shoulder preforming and shoulder forming. Figure 19 shows the state of the forming device 199 before shoulder preforming, and Figure 20 shows the state of the forming device 199 after shoulder preforming. Sliders 51a and 51b are operated downward in the Z direction, and shoulder forming rollers 144a and 144b form segment coil 10c, resulting in segment coil 10d. This forming is the same as in embodiment 1.

[0048] Figure 21 shows the state of the forming device 199 after the shoulder has been fully formed. When the sliders 51a, 51b are further moved downward in the Z direction, the shoulder forming punches 145a, 145b move further away from the cams 50a, 50b, i.e., toward the segment coil 10, and eventually come into contact with the shoulders 15a, 15b of the segment coil 10d. At this time, the actuator moves vertically downward, but the shoulder forming punches 145a, 145b move in a direction that bisects the forming angle of the shoulders 15a, 15b, thereby minimizing damage to the coil (such as peeling of the insulating coating and indentations on the coil).

[0049] The configuration of the forming device 199 of embodiment 2 described above reduces the number of actuators for shoulder pre-forming and main forming, contributing to the miniaturization of the forming device, while enabling forming that minimizes damage to the coil.

[0050] As described above, the coil forming apparatus for a rotating electric machine according to the second embodiment can achieve a deep shoulder forming angle and minimize damage to the coil. Furthermore, the number of actuators for shoulder preforming and main forming can be reduced, thereby enabling the compactness of the forming apparatus.

[0051] Third Embodiment A coil forming apparatus for a rotating electrical machine according to a third embodiment forms a coil having a tortoiseshell shape.

[0052] The coil forming device for a rotating electric machine according to embodiment 3 will be described, focusing on the differences from embodiment 1, based on Fig. 24, which is a perspective view of a tortoise shell coil, Fig. 25A, which is a top view of the tortoise shell coil, Fig. 25B, which is a bottom view of the tortoise shell coil, Fig. 26, which is a side view of the tortoise shell coil, Fig. 27, which is a perspective view of a group of coils for a rotating electric machine, and Figs. 28 and 29, which are explanatory diagrams of the tortoise shell coil forming process. In the drawings of embodiment 3, parts that are the same as or equivalent to those in embodiment 1 are given the same reference numerals. In order to distinguish it from embodiment 1, it is referred to as tortoise shell coil 200.

[0053] First, the configuration of the rotating electric machine coil forming apparatus of embodiment 3 will be described, with reference to differences from the rotating electric machine coil forming apparatus 99 of embodiment 1. This forming apparatus has basically the same configuration as the forming apparatus 99. However, since the shapes of the crank portion, top portion, and shoulder portion of the tortoiseshell coil 200 are different from those of the segment coil 10 of embodiment 1, this forming apparatus differs from the forming apparatus 99 in the shape of the crank portion forming punch 42, the shape of the top forming punch 43, the positions of the shoulder forming rollers 44a and 44b, and the shapes of the shoulder forming punches 45a and 45b.

[0054] In the first and second embodiments, a coil forming device for a rotating electric machine is used to form, from a straight coil conductor, a U-shaped coil having an apex that is the vertex of a triangle, a crank portion located at the apex of the triangle, and a shoulder portion connecting the oblique side and the straight portion. In the third embodiment, a coil forming device for a rotating electric machine is described that forms, from a straight coil conductor, a tortoiseshell-shaped coil having an apex that is the vertex of a triangle, a crank portion located at the apex of the triangle, and a shoulder portion connecting the oblique side and the straight portion.

[0055] First, the structure and features of the tortoise shell coil of the rotating electrical machine according to the third embodiment will be described with reference to Figures 24, 25A, 25B, and 26. Figure 24 is a perspective view showing a four-turn tortoise shell coil 200 formed by this forming device. Figure 25A is a top view of the tortoise shell coil 200, Figure 25B is a bottom view, and Figure 26 is a side view.

[0056] The tortoise shell coil 200 forms the winding of the stator of a rotating electrical machine. The tortoise shell coil 200 is a coil with a rectangular cross section, and is composed of a conductor made of copper and aluminum and an insulator made of a resin material. The conductor of the tortoise shell coil 200 is covered with an insulator to prevent a short circuit even if the tortoise shell coils 200 come into contact with each other.

[0057] The tortoiseshell coil 200 is formed by this forming device into a tortoiseshell shape having S-shaped crank portions 212a, 212b, and 212c, triangular apexes 213a, 213b, and 213c, and shoulder portions 215a1, 215a2, 215b1, 215b2, 215c1, and 215c2.

[0058] The oblique side connected to the apex 213a of the S-shaped crank portion 212a connects the straight portion 216a, which is the first turn, to the straight portion 216b, which is the second turn. The oblique side connected to the apex 213b of the S-shaped crank portion 212b connects the straight portion 216b, which is the second turn, to the straight portion 216c, which is the third turn. The oblique side connected to the apex 213c of the S-shaped crank portion 212c connects the straight portion 216c, which is the third turn, to the straight portion 216d, which is the fourth turn. Insulation has been scraped off at the ends of the straight portion 216a, which is the first turn, and the straight portion 216d, which is the fourth turn, to form stripped portions 217a and 217d where the coil conductor is exposed.

[0059] 27 shows a cage coil group 219 in which multiple tortoiseshell coils 200 are arranged in an annular shape. The cage coil group 219 is inserted into the stator core 20, and the straight portion 216a, which is the first turn, and the straight portion 216d, which is the fourth turn, are twisted and then electrically connected to form a predetermined winding connection, thereby forming a stator. The electrical connection is made by TIG welding, laser welding, or brazing.

[0060] Next, the manufacturing steps of the tortoise shell coil 200 will be described. First, in the first step, the crank portion 212a, the top portion 213a, and the shoulder portions 215a1 and 215a2 shown in Figure 28 are formed using this forming device. This coil is called the tortoise shell coil 230 during forming. After forming, the straight portion 216bz connected to the shoulder portion 215a2 is longer than in the first embodiment, but the forming method is exactly the same.

[0061] Next, in the second step, the straight portion 216bz is formed into a crank portion 212b, a top portion 213b, and shoulder portions 215b1 and 215b2 by this forming device, as shown in Fig. 29. This coil is called an in-forming hexagonal coil 231. The length of the straight portion 216cz is shorter than the length of the straight portion 216bz due to the forming of the straight portion 216bz.

[0062] Finally, in the third step, the straight portion 216cz is formed into the crank portion 212c, the top portion 213c, and the shoulder portions 215c1 and 215c2 by the forming device. As a result of this forming, the tortoiseshell coil 200 is formed as shown in Figures 24, 25A, and 25B.

[0063] Here, a four-turn tortoiseshell coil 200 with three apexes is used as an example, but the method can be applied regardless of the number of turns of the tortoiseshell coil. Also, the forming device 99 may be applied to only some of the apexes, and the remaining apexes may be formed by a different means.

[0064] As described above, the coil forming apparatus for a rotating electric machine according to the third embodiment can form a coil having a tortoiseshell shape by increasing the forming angle of the shoulder portion and suppressing damage to the coil.

[0065] Although various exemplary embodiments and examples are described in this disclosure, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are anticipated within the scope of the technology disclosed in this disclosure. For example, this includes cases where at least one component is modified, added, or omitted, or where at least one component is extracted and combined with components of another embodiment.

[0066] Various aspects of the present disclosure are summarized below as appendices.

[0067] (Supplementary Note 1) A coil forming device for a rotating electric machine that forms a U-shaped coil from a straight coil conductor, the U-shaped coil having an apex that is the vertex of a triangle, a crank portion located at the apex of the triangle, and a shoulder portion connecting the hypotenuse portion and the straight portion, the coil forming device comprising: a forming die that serves as a die for the crank portion, the apex, and the shoulder portion of the rotating electric machine coil, a crank portion forming punch that forms the crank portion, a apex forming punch that forms the apex, a shoulder forming roller that pre-forms the shoulder portion, and a shoulder forming punch that finally forms the shoulder portion. (Supplementary Note 2) The coil forming device for a rotating electric machine according to Supplementary Note 1, in which the shoulder forming roller and the shoulder forming punch are driven by the same actuator. (Supplementary Note 3) The coil forming device for a rotating electric machine according to Supplementary Note 1 or Supplementary Note 2, in which the shoulder forming punch forms the shoulder using a cam whose lower side is wider than its upper side. (Supplementary Note 4) The coil forming device for a rotating electric machine according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the shoulder forming punch has a pressing force that forms indentations of the same depth on both sides of the shoulder of the coil. (Supplementary Note 5) A method for forming a coil of a rotating electric machine, using the forming apparatus for forming a coil of a rotating electric machine described in Supplementary Note 1, comprising: a crank forming step of using the forming die and the crank portion forming punch to place a straight coil on the forming die and press it with the crank portion forming punch to form the crank portion of the coil; a top forming step of using the forming die and the top forming punch that forms the top portion to press down the coil, the crank portion of which has been formed in the crank forming step, with the top forming punch to form the top of the coil; a shoulder preforming step of pressing down a shoulder forming roller that preforms the shoulder of the coil to bend the coil to fit along a side surface of the forming die; and a shoulder final forming step of using the forming die and the shoulder forming punch that final forms the shoulder to press down the coil preformed in the shoulder preforming step (Supplementary Note 6) A coil for a rotating electric machine formed using the coil forming device for a rotating electric machine according to any one of Supplementary Note 1 to Supplementary Note 4 or the coil forming method for a rotating electric machine according to Supplementary Note 5.(Supplementary Note 7) A manufacturing method for a stator of a rotating electric machine, comprising: a squirrel-cage coil forming step of arranging squirrel-cage coils in an annular shape using coils of a rotating electric machine formed using the coil forming apparatus for a rotating electric machine according to any one of Supplementary Note 1 to Supplementary Note 4 or the coil forming method for a rotating electric machine according to Supplementary Note 5, a coil inserting step of sequentially inserting straight portions of the coils into slots of a stator core of a rotating electric machine, a twist forming step of twisting lower portions of the straight portions of the coils inserted into the slots of the stator core, and an electrical connecting step of electrically connecting peeled portions of lower portions of the straight portions of the coils so as to form a specified winding connection. (Supplementary Note 8) A rotating electric machine comprising: a stator of a rotating electric machine manufactured by the manufacturing method for a stator of a rotating electric machine according to Supplementary Note 7, and a rotor arranged inside the stator of the rotating electric machine.

[0068] 10, 10b, 10c, 10d segment coil, 10a straight coil, 12 crank portion, 13 top portion, 14a, 14b oblique side portion, 15a, 15b shoulder portion, 16a, 16b straight portion, 17a, 17b peeling portion, 19 cage coil group, 20 stator core, 21 yoke, 22 teeth, 23 shoe, 24 slot, 30 stator after coil insertion, 31 stator, 32 rotor, 41 forming die, 41a crank forming portion, 41b top forming portion, 41c shoulder forming portion, 41d side portion, 41t apex, 42 crank portion forming punch, 43 top forming punch, 44a, 44b, 144a, 144b shoulder forming roller, 45a, 45b, 145a, 145b Shoulder forming punch, 46a, 46b Groove, 47a, 47b Tip thin plate, 50a, 50b Cam, 51a, 51b Slider, 52a, 52b Block, 99, 199 Forming device, 100 Rotating electric machine, 200 Tortoise shell coil, 230, 231 Tortoise shell coil during forming, 212a, 212b, 212c Crank portion, 213a, 213b, 213c Top portion, 215a1, 215a2, 215b1, 215b2, 215c1, 215c2 Shoulder portion, 216a, 216b, 216c, 216d, 216bz, 216cz Straight portion, 217a, 217d Peeling portion, 219 Cage coil group.

Claims

1. A coil forming device for a rotating electrical machine that forms a coil having a top that is the apex of a triangular shape, a crank portion located at the top of the triangular shape, and a shoulder portion that connects the hypotenuse portion and the straight portion from a straight coil conductor, a forming die that serves as a die for the crank portion, the top, and the shoulder of the coil of the rotating electrical machine, a crank portion forming punch that forms the crank portion, a top forming punch that forms the top, a shoulder forming roller that pre-forms the shoulder portion, and a shoulder forming punch that performs final forming of the shoulder portion, A coil forming device for a rotating electrical machine comprising the above.

2. The coil forming device for a rotating electrical machine according to claim 1, wherein the coil is U-shaped.

3. The coil forming device for a rotating electrical machine according to claim 1, wherein the coil is tortoise shell-shaped.

4. The coil forming device for a rotating electrical machine according to any one of claims 1 to 3, wherein the shoulder forming roller and the shoulder forming punch are driven by the same actuator.

5. The coil forming device for a rotating electrical machine according to any one of claims 1 to 3, wherein the shoulder forming punch uses a cam with a wider width at the lower side than the upper side to form the shoulder portion.

6. The coil forming device for a rotating electrical machine according to any one of claims 1 to 3, wherein the shoulder forming punch has a pressing force that forms indentations with the same depth on both sides of the shoulder portion of the coil.

7. Using the coil forming device for a rotating electrical machine according to claim 1 or claim 2, a crank forming step of arranging a straight coil on the forming die and pressing it with the crank portion forming punch to form the crank portion of the coil using the forming die and the crank portion forming punch; a top forming step of pressing down the coil formed with the crank portion in the crank forming step with the top forming punch using the forming die and the top forming punch that forms the top to form the top of the coil; a shoulder pre-forming step of pressing down a shoulder forming roller that pre-forms the shoulder portion of the coil to bend the coil along the side surface of the forming die; a shoulder final forming step of pressing down the coil pre-formed in the shoulder pre-forming step using the forming die and the shoulder forming punch that performs final forming of the shoulder portion to perform final forming of the shoulder portion; A method for forming a coil of a rotating electrical machine comprising the above.

8. A coil of a rotating electrical machine having a straight portion, a top portion that is the apex of a triangular shape, a crank portion located at the top portion of the triangular shape, and shoulders that connect the hypotenuse portions connected to both sides of the top portion and the straight portion, A coil of a rotating electrical machine, wherein an indentation is formed at a predetermined distance from the apex of the shoulder, excluding the shoulder, on at least one side of the shoulder.

9. Using a coil of a rotating electrical machine formed using the forming apparatus for a coil of a rotating electrical machine according to Claim 1 or Claim 2, A cage coil forming step of arranging in an annular shape to form a cage coil; A coil insertion step of sequentially inserting the straight portion of the coil into the slots of the stator core of the rotating electrical machine; A twist forming step of twist-forming the lower portion of the straight portion of the coil inserted into the slot of the stator core; An electrical connection step of electrically connecting the peeled portions of the lower portions of the straight portions of the coil so as to constitute a specified winding connection; A method for manufacturing a stator of a rotating electrical machine, comprising:

10. A stator of a rotating electrical machine having a coil of a rotating electrical machine according to Claim 8, A rotating electrical machine comprising a rotor disposed inside the stator of the rotating electrical machine.

11. Using a coil of a rotating electrical machine formed using the forming method for a coil of a rotating electrical machine according to Claim 7, A cage coil forming step of arranging in an annular shape to form a cage coil; A coil insertion step of sequentially inserting the straight portion of the coil into the slots of the stator core of the rotating electrical machine; A twist forming step of twist-forming the lower portion of the straight portion of the coil inserted into the slot of the stator core; An electrical connection step of electrically connecting the peeled portions of the lower portions of the straight portions of the coil so as to constitute a specified winding connection; A method for manufacturing a stator of a rotating electrical machine, comprising: