Coil forming apparatus and coil forming method

Abstract

To provide a coil molding device and a coil molding method capable of winding a belt-like coil around a coil winding jig by curving the belt-like coil to generate sufficient spring-back.SOLUTION: A coil molding device 1 is constituted so that a belt-like coil 2 is nipped between a curving member 18 and a guide member (first guide member 19) while an entire side end 7 of the belt-like coil 2 is accommodated in a slide-contact face 23 of the curving member 18, at a position including a turning start position P1 at which the belt-like coil start being turned and transported, and that each side end 7 of the belt-like coil 2 exists in the side end 7 until a force point F passes through an area of the slide-contact face 23 by the transportation, while using an end 24 of the slide-contact face 23 in a transportation direction of the belt-like coil 2 as the force point Pf to the side end 7.SELECTED DRAWING: Figure 7

Description

Technical Field

[0005] ,

[0004] ,

[0001] The present invention relates to a coil forming apparatus and a coil forming method.

Background Art

[0002] The stator of a rotating electrical machine has a wound strip coil. The strip coil is previously formed into a substantially cylindrical wound state with a smaller diameter than the inner diameter of the stator core and inserted inside the stator core. The wound strip coil is expanded in diameter inside the stator core and is mounted by inserting the straight portion of the strip coil into the slot of the stator core.

[0003] [[ID=I5]] Conventionally, it is known to form a strip coil into a substantially cylindrical wound state by winding it around a cylindrical coil winding jig while feeding it one pitch at a time (see, for example, Patent Document 1). When winding a coil around a coil winding jig to form a wound state, it is important to wind it accurately so that a plurality of straight portions do not shift in position. The above prior art aligns the overlapping of the straight portions immediately before being wound around the coil winding jig by inserting a preliminary alignment member between adjacent straight portions at a position immediately before the coil winding jig on the conveyance path of the strip coil.

[0004] However, the above prior art does not specifically disclose how to convey the strip coil to the coil winding jig and wind it. In particular, when winding around the coil winding jig, no separate perspective is shown on the means for arcuately curving the strip coil along the outer periphery of the coil winding jig. If this curving is not performed well, the strip coil may not reach the specified wound state, which may cause quality defects. The occurrence of quality defects leads to an increase in material consumption and wasteful consumption of resources. In addition, the operating time of the manufacturing equipment required to achieve the planned production quantity is extended, and power consumption increases. As a result, it will have an adverse impact on the global environment.

[0005] In view of the above circumstances, the applicant has developed a technology that allows for the precise shaping of a strip coil into an arc along the outer circumference of a coil winding jig when winding the strip coil onto the coil winding jig, thereby easily forming it into a predetermined winding state, and has obtained a patent for this technology in Japan (Patent Document 2). When a strip coil that has been sufficiently shaped into an arc is inserted into a slot of the stator core of a rotating electric machine, its own springback causes the multiple linear conductors of the strip coil to remain aligned within the slot without scattering. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 4953032 [Patent Document 2] Patent No. 7222007 Publication [Overview of the project] [Problems that the invention aims to solve]

[0007] Incidentally, in electric motors for electric vehicles and the like, it is necessary to insert relatively thick strip-shaped coils into slots in stator cores with relatively small inner diameters. The inventors have found that when inserting relatively thick strip-shaped coils into slots in stator cores with relatively small inner diameters, if the strip-shaped coils are shaped using conventional methods, the linear conductors of the strip-shaped coils tend to unravel within the slots. Furthermore, they have found that this phenomenon occurs because the springback force when the strip-shaped coils are inserted into the slots does not exert the required strength due to insufficient shaping of the strip-shaped coils.

[0008] The present invention has been made in view of the above circumstances, and aims to provide a coil forming apparatus and a coil forming method that can shape a strip coil so that sufficient springback occurs when winding it onto a coil winding jig. If a strip coil can be processed into a predetermined winding state with a high yield without producing defective products, it will be possible to suppress the wasteful consumption of resources, reduce the operating time of the manufacturing equipment, and save electricity, thereby contributing to the preservation of the global environment. [Means for solving the problem]

[0009] (1) The coil forming apparatus of the present disclosure (for example, coil forming apparatus 1 described later) includes a coil conveying mechanism (for example, coil conveying mechanism 4 described later) that guides and conveys a strip coil (for example, strip coil 2 described later) having a plurality of straight sections (for example, straight section 6 described later) and side ends (for example, side end 7 described later) connected to each end of the plurality of straight sections, in a predetermined rotating conveying section (for example, rotating conveying section S2 described later), by a guide member (for example, guide member 17 described later), so that it traces a rotating trajectory that gradually moves inward in the direction of the turning radius from a turning start position (for example, rotating start position P1 described later), and the coil conveying mechanism that guides the strip coil being conveyed by the coil conveying mechanism, in the region including the turning start position, the entire side end of each of them with its own sliding contact surface (for example, sliding contact surface 23 described later) The invention is characterized by comprising: a shaping member (for example, a shaping member 18, described later) that holds the strip coil between itself and the guide member in a state where it is fully contained, and sets the end of the sliding surface in the direction of transport (for example, end 24, described later) as the point of force applied to the side end (for example, point of force applied Pf, described later), and such point of force is present within the side end until each of the side ends of the strip coil passes through the region of the sliding surface by the transport, thereby shaping the strip coil into an arc shape; and a coil winding jig (for example, a coil winding jig 3, described later) that has a plurality of comb-shaped grooves (for example, a comb-shaped groove 15, described later) provided radially from its own rotational axis, and rotates and winds the strip coil that has been shaped by the shaping member, inserting the plurality of straight portions into each of the plurality of comb-shaped grooves.

[0010] (2) The coil forming method according to the present disclosure comprises a coil transport step in which a strip-shaped coil (e.g., a strip-shaped coil 2 described later) having a plurality of straight sections (e.g., a straight section 6 described later) and side ends (e.g., side ends 7 described later) connected to each end of the plurality of straight sections is guided and transported in a predetermined rotating transport section (e.g., a rotating transport section S2 described later) by a guide member (e.g., a guide member 17 described later) so as to trace a rotating trajectory from a rotating start position (e.g., a rotating start position P1 described later), and a shaping member (e.g., a shaping member 18 described later) having a sliding contact surface (e.g., a sliding contact surface 23 described later) to the strip-shaped coil being transported in the coil transport step, shaping each of the side ends in the region including the rotating start position The present invention is characterized by comprising: a shaping step in which the strip coil is shaped into an arc by sandwiching it between the guide member while the body is fully contained within the sliding contact surface, so that the end of the sliding contact surface in the direction of transport (for example, the end 24 described later) is used as the point of force application to the side end (for example, the point of force application described later), and the point of force application remains within the side end until each of the side ends of the strip coil passes through the region of the sliding contact surface by the transport; and a coil winding step in which the strip coil shaped in the shaping step is wound up by rotating a coil winding jig having a plurality of comb-shaped grooves (for example, the comb-shaped grooves described later) provided radially from its rotational axis, so that the plurality of straight portions are inserted into each of the plurality of comb-shaped grooves. [Effects of the Invention]

[0011] In the coil forming apparatus described in (1) above, the entire side end of the strip coil is sandwiched between the shaping member and the guide member, including the position where the strip coil begins to be conveyed in a rotational manner, so that it fits completely within the sliding contact surface of the shaping member. The end of the sliding contact surface in the conveying direction of the strip coil is used as the point of force application to the side end, and this point of force application remains within the side end until each side end of the strip coil passes through the area of ​​the sliding contact surface by the conveying. Therefore, the point of force application continues to act on the side end until the side end has finished passing through the area of ​​the sliding contact surface, and a large deflection for shaping can always be generated at the side end. Consequently, the sufficiently shaped strip coil can be neatly arranged within the multiple comb-shaped grooves of the coil winding jig without scattering. As a result, during the subsequent process of expanding the diameter of the strip coil from the coil winding jig into the slots of the stator core, it is prevented that the strip coil will scatter within the slots of the stator core or protrude from the slots of the stator core, thereby improving work efficiency.

[0012] According to the coil forming method described in (2) above, the entire side end of the strip coil is sandwiched between the shaping member and the guide member, including the position where the strip coil begins to be conveyed in a rotational manner, so that it fits completely within the sliding contact surface of the shaping member. The end of the sliding contact surface in the conveying direction of the strip coil is used as the point of force application to the side end, and this point of force application remains within the side end until each side end of the strip coil passes through the area of ​​the sliding contact surface by the conveying. Therefore, the point of force application continues to act on the side end until the side end has finished passing through the area of ​​the sliding contact surface, and a large deflection for shaping can always be generated at the side end. Consequently, the sufficiently shaped strip coil can be neatly arranged within the multiple comb-shaped grooves of the coil winding jig without scattering. As a result, during the subsequent process of expanding the diameter of the strip coil into the slots of the stator core from the coil winding jig, it is prevented that the strip coil will scatter within the slots of the stator core or protrude from the slots of the stator core, thereby improving work efficiency. [Brief explanation of the drawing]

[0013] [Figure 1] This is a side view showing a coil forming apparatus according to the present disclosure. [Figure 2] This figure shows a strip-shaped coil formed by the coil forming apparatus shown in Figure 1. [Figure 3] Figure 1 is a schematic diagram showing the coil winding jig in the coil forming apparatus. [Figure 4] Figure 3 is a schematic diagram showing a strip coil being wound onto a coil winding jig. [Figure 5] This figure shows the configuration around the shaping member in the coil forming apparatus shown in Figure 1. [Figure 6] This figure shows the transport status of the strip-shaped coil in the area indicated in Figure 5. [Figure 7] Figure 5 is a diagram illustrating the function of the shape-setting member. [Figure 8] This diagram illustrates the force acting on the strip-shaped coil due to the shaping member shown in Figure 5. [Figure 9] This figure illustrates the function of the shaping member shown in Figure 5. [Figure 10] This figure illustrates the function of the shaping member shown in Figure 5. [Figure 11] This figure illustrates the function of the shaping member shown in Figure 5. [Modes for carrying out the invention]

[0014] The coil forming apparatus of this disclosure will be described below with reference to the drawings. Figure 1 is a side view showing the coil forming apparatus 1 of this disclosure. Figure 2 is a diagram showing a strip coil 2 to be formed by the coil forming apparatus 1. Figure 1 shows the coil forming apparatus 1 without the strip coil 2. When forming the strip coil 2 with the coil forming apparatus 1, as shown in Figure 2, the strip coil 2 is held by the conveyor body 5 in the coil conveying mechanism 4 of the coil forming apparatus 1, and the strip coil 2 is conveyed from the linear conveying section S1 to the following rotating conveying section S2 of the coil conveying mechanism 4, during which the strip coil 2 is shaped into an arc and wound onto the coil winding jig 3. Figure 3 shows a schematic perspective view of the coil winding jig 3, and Figure 4 shows a schematic perspective view of the strip coil 2 wound onto the coil winding jig 3.

[0015] FIG. 2 shows a state in which the strip coil 2 is gripped in the linear conveyance section S1 of the coil conveyance mechanism 4. The strip coil 2 is composed of a coil conductor 2a which is a conductor strip body having an insulating layer on its outer surface and having a substantially rectangular cross-sectional shape, and exhibits a long waveform belt shape by a forming process of a predetermined shaped coil. The strip coil 2 has a plurality of parallel straight portions 6 and side end portions 7 respectively connected to both ends of the plurality of straight portions 6, and extends in a belt shape in a direction orthogonal to the straight portions 6 . The straight portions 6 are portions to be inserted into slots provided in the inner periphery of the stator core of a rotating electric machine (not shown), are linearly formed in the same direction, and extend in parallel at a constant interval. The side end portions 7 are respectively connected to both ends in the extending direction of the straight portions 6.

[0016] Each of the side end portions 7 is in a form of alternately connecting one ends and the other ends of adjacent straight portions 6 in a mountain shape in a loop shape formed by two straight portions 6 and two side end portions 7, and is shifted and overlapped at the pitch of the straight portions 6. The side end portions 7 constitute coil end portions that respectively project in the axial direction of the stator core from the slots when the strip coil 2 is mounted in the slots of the stator core of the rotating electric machine.

[0017] The coil conveyance mechanism 4 conveys the strip coil 2 by the movement of the carrier 5. The carrier 5 is configured by stacking and connecting a plurality of piece members 8 having the same substantially rectangular plate shape along their thickness directions. Each of the plurality of piece members 8 is guided by a pair of parallel conveyance rails 9 and moves in a stacked and aligned manner. The pair of conveyance rails 9 are provided from the linear conveyance section S1 of the coil conveyance mechanism 4 through the turning conveyance section S2 to the linear reverse conveyance section S3, and are composed of plate-like members having a constant width dimension.

[0018] In a side view in Figure 1, the transport rail 9 forms a lateral U-shaped transport path that extends from a straight transport section S1 through a rotating transport section S2 to a straight reverse transport section S3. Each of the multiple piece members 8 has a first gripping claw 10 and a second gripping claw 11 projecting from its upper end surface, spaced apart in the thickness direction. In the transport body 5, a gripping groove 12 is formed between the first gripping claw 10 of one piece member 8 and the second gripping claw 11 of the other piece member 8, for gripping the straight portion 6 of the strip-shaped coil 2.

[0019] The coil transport mechanism 4 grips the straight section 6 in the gripping groove 12 of the transport body 5 and transports the strip-shaped coil 2 from the linear transport section S1 to the spiral transport section S2. Each of the multiple piece members 8 has guide protrusions (not shown) protruding from both sides in the width direction, which is the extending direction of the gripping groove 12, near its lower end surface. Each piece member 8 is slidably housed and guided in guide grooves (not shown) provided on the opposing surfaces of each of the pair of transport rails 9 along the extending direction of the transport rails 9. Although Figure 2 shows only a portion of the strip-shaped coil 2, the strip-shaped coil 2 in this disclosure has a length that allows it to be wound multiple times around the coil winding jig 3.

[0020] The linear transport section S1, the rotary transport section S2, and the linear reverse transport section S3 described above are divisions of the transport sections in the transport of the block members 8, but the linear transport section S1 and the rotary transport section S2 directly correspond to divisions of the transport path of the strip coil 2. In the linear transport section S1, the series of block members 8 holding the strip coil 2 are transported linearly toward the coil winding jig 3. In the rotary transport section S2 following the linear transport section S1, as the series of block members 8 are transported in an arc shape, the strip coil 2 that was held by the block members 8 is sequentially transferred to the coil winding jig 3 and wound up by the guide member 17, which will be described later. In the linear reverse transport section S3 following the rotary transport section S2, the series of block members 8 after releasing the strip coil 2 are transported linearly in the opposite direction to the linear transport section S1.

[0021] The coil winding jig 3 of the coil transport mechanism 4 is shown in Figures 3 and 4. The coil winding jig 3 has a substantially cylindrical jig body 13, a plurality of comb-toothed portions 14 projecting radially from the outer circumference of the jig body 13, a plurality of comb-toothed grooves 15 provided between adjacent comb-toothed portions 14 in the circumferential direction, and an axial hole 16 opening at the center of the jig body 13. The comb-toothed portions 14 and comb-toothed grooves 15 are provided at both ends of the jig body 13 in the axial direction, respectively. The circumferential phase of the comb-toothed portions 14 and comb-toothed grooves 15 at one end of the jig body 13 and the comb-toothed portions 14 and comb-toothed grooves 15 at the other end is aligned. The coil winding jig 3 of this disclosure has 72 comb-toothed grooves 15 at each end of the jig body 13 in the axial direction. The number of these comb-toothed grooves 15 corresponds to the number of slots in the stator core of the rotating electric machine on which the strip coil 2 is mounted.

[0022] The distance between the comb-tooth portion 14 and comb-shaped groove 15 at one end of the jig body 13 and the comb-tooth portion 14 and comb-shaped groove 15 at the other end is approximately equal to the length of the straight portion 6 of the strip coil 2 in the extending direction. Therefore, the straight portion 6 of the strip coil 2 can be accommodated across the comb-shaped groove 15 at both ends of the jig body 13.

[0023] The coil winding jig 3 is formed such that its outer diameter, defined by the radial length of the comb-shaped grooves 14, is less than or equal to the inner diameter of the stator core, so that it can be inserted inside the stator core of the rotating electric machine. The coil winding jig 3 is positioned in a predetermined location on the coil forming apparatus 1, driven by a motor (not shown), and is rotatable clockwise in a side view in Figure 1, around the shaft hole 16. As shown in Figure 4, the strip coil 2 is formed into a substantially cylindrical wound state. In the wound state, the coil conductors 2a at the side ends 7 of the strip coil 2 protrude from the comb-shaped grooves 15 in the direction of extension, while the coil conductors 2a of the straight portion 6 are housed within the comb-shaped grooves 15, so there is no risk of displacement. Therefore, the strip coil 2 can stably maintain a substantially cylindrical wound state. The strip coil 2 of this disclosure is wound multiple times around the coil winding jig 3 by multiple rotations of the coil winding jig 3.

[0024] Figure 1, along with Figures 5 and 6, illustrates the configuration of the guide member 17 that guides the side end 7 of the strip coil 2 in the coil transport mechanism 4, and the shaping member 18 that shapes the strip coil 2 into an arc when it is wound onto the coil winding jig 3. Figure 5 is an enlarged view of the configuration of the shaping member 18 in the coil forming apparatus 1. Figure 6 is a diagram showing the transport status of the strip coil 2 in the part shown in Figure 5. In Figures 5 and 6, the same reference numerals are used for parts corresponding to those in Figure 1. The guide member 17 is a member that guides and transports the strip coil 2 from the turning start position P1, which transitions from the linear transport section S1 to the turning transport section S2, so that it traces a turning trajectory that gradually moves inward in the direction of the turning radius. The shaping member 18 is a member that shapes the strip coil 2 into an arc when viewed from the side.

[0025] The guide members 17 are a pair of plate-shaped members provided on both outer sides of the pair of transport rails 9 shown in Figure 2. In Figure 1, which shows a side view of the coil forming apparatus 1, the guide member 17 on the near side is shown. In the side view in Figure 1, the guide member 17 on the far side is the same shape and dimensions as the guide member 17 on the near side and is arranged symmetrically. Therefore, from here on, the guide members 17 will be described as representative of the guide member 17 shown in Figure 1, which is on the near side.

[0026] The guide member 17 in the coil forming apparatus 1 of this disclosure includes a portion of a first guide member 19 positioned in a region corresponding to the rotary conveying section S2, and a portion of a second guide member 20 positioned in a region that is clockwise connected to the rotary conveying section S2. The first guide member 19 corresponds to the entire area of ​​the rotary conveying section S2 and is positioned in a semi-circular region on the left side near the outer circumference of the coil winding jig 3 in a side view in Figure 1.

[0027] The first guide member 19 has a curved first guide surface portion 21 that, in a side view, gradually moves inward in the turning radius direction in a clockwise direction in the section from the turning start position P1 to the end position P2 of the turning conveying section S2. The first guide surface portion 21 guides the strip coil 2 in a turning trajectory that gradually moves inward in the turning radius direction in part or all of its area. The first guide surface portion 21 slides against and presses the strip coil 2 as it is being conveyed in the turning conveying section S2, moving it from the conveyor body 5 side to the coil winding jig 3 side.

[0028] In detail, the strip coil 2, which is being conveyed in a rotational manner while being gripped by the conveyor 5 with its straight portion 6 being gripped in each of the gripping grooves 12 formed between a series of multiple piece members 8 in the conveyor 5, is acted upon by the first guide member 19 as follows: The first guide surface portion 21 of the first guide member 19, which is curved inward in the rotational radius direction in a clockwise direction when viewed from the side, slides against and presses against the coil conductor 2a at the side end 7. This sliding contact and pressing by the first guide surface portion 21 causes the coil conductor 2a of the straight portion 6 to detach from the gripping grooves 12 and be successively transferred to the comb-shaped grooves 15 on the coil winding jig 3 side. In this way, the strip coil 2 detaches from the piece members 8 of the conveyor 5 and is wound onto the coil winding jig 3 side.

[0029] The second guide member 20 is positioned such that, in a side view in Figure 1, its second guide surface portion 22 extends over the entire semi-circular region near the outer circumference on the right side of the coil winding jig 3, from the end position P2 of the rotating conveying section S2. The second guide member 20 is a plate-shaped member with a right semi-circular second guide surface portion 22 at its left end, and a certain extension from the second guide surface portion 22 to its rear side, i.e., to the right in Figure 1, with a straight portion perpendicular to the straight conveying section S1 and the straight reverse conveying section S3 at its right end 20a. The upper and lower ends of the second guide member 20 are located in the region between the straight reverse conveying section S3 and the straight conveying section S1 on the conveying rail 9.

[0030] The second guide surface portion 22 acts to slide against and press against the coil conductor 2a at the side end 7 of the strip-shaped coil 2, which has been detached from the coil member 8 of the conveyor body 5 and wound onto the coil winding jig 3 side by the first guide surface portion 21 of the first guide member 19 described above. That is, the second guide surface portion 22 of the second guide member 20, which is curved in the direction of the rotation radius and gradually moves inward in a clockwise direction when viewed from the side, slides against and presses against the coil conductor 2a at the side end 7 as the coil winding jig 3 rotates. As a result, the coil conductors 2a of the straight portions 6 that have been moved from the conveyor body 5 side to the outermost position in the comb-shaped groove 15 of the coil winding jig 3 by the first guide surface portion 21 are pressed to the second outermost position from the outermost position via the coil conductors 2a that are stacked on top of each other in the next rotation, and enter the comb-shaped groove 15 to a predetermined depth. As a result, the strip-shaped coil 2 is wound onto the coil winding jig 3 in the standard configuration in which the coil conductors 2a of the straight section 6 are pressed into the comb-shaped grooves 15 in multiple layers (Figure 4).

[0031] A shaping member 18 is provided near the lower end of the second guide member 20. The shaping member 18 is a rectangular plate-shaped member in plan view, with its width direction being the thickness direction of the second guide member 20 (i.e., the direction perpendicular to the plane of the paper in Figure 1), and extending from the right end 20a side of the second guide member 20 in the direction of extension of the linear conveying section S1. The shaping member 18 has a sliding contact surface 23 that slides against the conveyed strip coil 2 in the region spanning the linear conveying section S1 including the turning start position P1 and the turning conveying section S2. In Figure 1, the sliding contact surface 23 is the lower surface of the shaping member 18. As shown in Figure 6, the strip coil 2 moves sandwiched between the sliding contact surface 23 and the first guide surface 21, with the coil conductors 2a of the side end 7 connecting the straight sections 6,6 overlapping and intersecting with the coil conductors 2a located directly below it.

[0032] On the side (top surface) of the shaping member 18 opposite to the sliding contact surface 23, a straightening surface 25 is formed, which is an arc-shaped concave surface in side view and whose thickness partially decreases towards the end 24. The straightening surface 25 slides against the coil conductor 2a at the side end 7 of the strip-shaped coil 2, which is wound onto the coil winding jig 3 and rotates, from the outer circumference side with respect to the rotation, and corrects the position of the coil conductor 2a at the side end 7 so that it does not bend outward from the extension direction of the coil conductor 2a of the corresponding straight portion 6.

[0033] Next, the function of the shaping member 18 will be described in more detail with reference to Figures 7 to 11. Figure 7 is a schematic diagram illustrating the function of the shaping member 18. Figure 8 is a diagram illustrating the force acting on the strip coil 2 by the shaping member 18. In Figures 7 and 8, the same reference numerals are used for parts corresponding to Figures 1, 5, and 6. The arrows in Figure 7 indicate the direction in which the coil conductor 2a moves relative to the shaping member 18. In Figure 7, the coil conductor 2a of the V-shaped side end 7, which is convex downwards in the illustration and connected to the coil conductor 2a of two parallel straight sections 6, is shown moving along the sliding contact surface 23, which is the lower surface of the shaping member 18.

[0034] Here, the part of the coil conductor 2a at the side end 7 of the mountain shape that corresponds to the peak of the mountain is referred to as the peak 7a. Also, of the two parts where the coil conductor 2a of the side end 7 is connected to the coil conductor 2a of the straight part 6, the left part in Figure 7 is referred to as the left shoulder 7b, and the right part is referred to as the right shoulder 7c. That is, in relative movement with respect to the shaping member 18, the left shoulder 7b is ahead in phase of the right shoulder 7c. In Figure 7, the relative movement between the coil conductor 2a of the side end 7 and the shaping member 18 is shown side by side in phase P1, where the phase is relatively advanced, and phase P2, where the phase is relatively lagging.

[0035] In Phase P1, when most of the coil conductor 2a at the V-shaped side end 7 in Figure 7 is in the region of the sliding contact surface 23, which is the lower surface of the shaping member 18, the end 24 of the sliding contact surface 23 applies bending stress to the coil conductor 2a with the contact point Pf being the point of force application. In Phase P1, the point of force application Pf is located near the left shoulder portion 7b. As the process transitions from Phase P1 to Phase P2, the point of force application Pf moves along the coil conductor 2a toward the top portion 7a. In the coil forming apparatus 1 of this disclosure, the shaping member 18 has a shape and dimensions that enable it to maintain a state in which the entire side end 7 of the conveyed and moving strip-shaped coil 2 is completely contained within the sliding contact surface 23.

[0036] In other words, the coil conductor 2a at the side end 7, including its top 7a, remains contained within the sliding contact surface 23. Therefore, even when transitioning to phase P2, and even afterward, the point of force application Pf remains on the coil conductor 2a at the side end 7, applying bending stress to the coil conductor 2a. As a result, even though the coil conductor 2a at the side end 7 has a shape that protrudes toward the top 7a while sloping from the left shoulder 7b and right shoulder 7c, the entire length from the left shoulder 7b through the top 7a to the right shoulder 7c continues to receive bending stress from the end 24 at the point of force application Pf until it passes the end 24 of the sliding contact surface 23.

[0037] Therefore, as shown in Figure 8, sufficient deflection w occurs in the coil conductor 2a at the side end 7. As a result, the strip coil 2 is wound onto the coil winding jig 3 with sufficient arc shape at the side end 7. This allows it to generate the required springback when inserted into the slot in the stator core of the rotating electric machine. Figure 8 shows the point of force application Pf, along with the two fulcrum points Fu1 and Fu2 necessary to generate the deflection w.

[0038] Next, the fulcrums Fu1 and Fu2 will be explained with reference to Figures 9 to 11. Figure 9 is a diagram that shows the viewpoint for this explanation. In Figure 9, for the sake of explanation, the coil conductor 2a of the strip coil 2 is shown, excluding the coil winding jig 3. We will focus on the coil conductor 2a portion of the pair of straight sections 6, 6 and the side end 7 connected to them. Here, we will observe the portion of the side end 7 from the top 7a to the right shoulder 7c in the direction of arrow A. The area near the right shoulder 7c is supported by the spool member 8, which was explained with reference to Figures 1 and 2, as shown in Figure 10.

[0039] More specifically, the portion near the right shoulder 7c of the coil conductor 2a of the side end 7 is supported by the groove bottom 12a of the gripping groove 12 formed between the first gripping claw 10 of the piece member 8 and the adjacent second gripping claw 11 of the piece member 8. The portion of the piece member 8 supported by the groove bottom 12a in this way corresponds to the fulcrum Fu1 in Figure 9.

[0040] On the other hand, the portion near the top 7a is supported by the portion of the coil conductor 2a behind itself in the overlapping portion of the coil conductor 2a of the side end 7, as shown in Figure 11. In detail, as explained with reference to Figure 6, the strip coil 2 moves while sandwiched between the sliding contact surface 23 and the first guide surface portion 21, with a pair of parallel straight portions 6, 6 and the coil conductor 2a of the side end 7 that connects the straight portions 6, 6 overlapping and intersecting with the coil conductor 2a located directly below itself.

[0041] The portion of the coil conductor 2a that is supported by another coil conductor 2a located directly below it and overlapping and intersecting it corresponds to the fulcrum Fu2 in Figure 9. From the point of force Pf located between fulcrum Fu1 and fulcrum Fu2 and undergoing relative displacement, bending stress is effectively and continuously applied to the coil conductor 2a, resulting in the required deflection w. As a result, the strip coil 2 is wound onto the coil winding jig 3 with sufficient arc-shaped deformation at its side ends 7. Therefore, when inserted into the slot in the stator core of the rotating electric machine, it becomes capable of generating the required springback.

[0042] Next, a coil forming method for shaping a strip coil 2 into an arc shape using this coil forming apparatus 1 will be described. The coil forming method includes a coil transport step, a shaping step, and a coil winding step.

[0043] In the coil transport process, a strip-shaped coil 2 having multiple straight sections 6 and side ends 7 connected to each end of the multiple straight sections 6 is transported by a guide member 17 in a predetermined rotating transport section S2, so as to trace a rotating trajectory from the rotation start position P1.

[0044] In the shaping process, the shaping member 18, which has a sliding contact surface 23 for the shaping member 18, is used to sandwich the shaping member 18 between itself and the first guide member 19 in the region including the rotation start position P1, so that the entire side end 7 of the sliding contact surface 23 is fully contained within the sliding contact surface 23. The end 24 of the sliding contact surface 23 in the direction of transport becomes the point of force Pf applied to the side end 7, and the point of force Pf remains within the side end 7 until each side end 7 of the shaping member 18 passes through the region of the sliding contact surface 23 by the transport, thereby shaping the shaping member 18 into an arc shape.

[0045] In the coil winding process, the strip-shaped coil 2, which has been shaped in the shaping process, is wound by rotating a coil winding jig 3, which has multiple comb-shaped grooves 15 arranged radially from its own rotational axis, so that multiple straight sections 6 are inserted into each of the multiple comb-shaped grooves 15.

[0046] In the coil forming method of this disclosure, the strip coil 2 is wound onto the coil winding jig 3 with sufficient arc-shaped curvature at its side ends 7. Therefore, when inserted into the slots of the stator core of a rotating electric machine, it becomes capable of generating the required springback.

[0047] The above describes one embodiment of the coil forming apparatus of the present disclosure, but the technical concept of the present disclosure is not limited thereto. Within the scope of the technical concept of the present disclosure, the details of the configuration may be changed as appropriate. For example, in the above example, a straightening surface 25 is set on the upper side of the same shaping member 18, and a sliding contact surface 23 having an end portion 24 that acts on shaping is set on the lower side, but instead, the member having the straightening surface 25 and the member having the sliding contact surface 23 may be made of separate members. [Explanation of Symbols]

[0048] Fu1, Fu2…Fulcrum P1... Turning start position P2...End position Pf... point of emphasis S1...Straight transport section S2...Swivel transport section S3...Straight reverse transport section 1…Coil forming machine 2… Strip coil 2a... Coil conductor 3…Coil winding jig 4…Coil transport mechanism 5... Carrier 6…Straight part 7…Side end 7a…Top 7b…Left shoulder 7c…Right shoulder 8…piece parts 9… Transport rails 10...First gripping claw 11...Second gripping claw 12...Gripping groove 12a…Groove bottom 13... Jig body 14…Comb teeth 15…Ceptate grooves 16…Axial hole 17… Guide component 18...Shaping material 19...First guide member 20...Second guide member 20a...Right end 21...First guide surface section 22...Second guide surface section 23…Sliding surface 24…end 25…Frontal Correction

Claims

1. A coil transport mechanism that transports a strip-shaped coil having multiple straight sections and side ends connected to each end of the multiple straight sections, by guiding it in a predetermined rotating transport section so that it traces a rotating trajectory that gradually moves inward in the direction of the rotation radius from the rotation start position, using a guide member. A shaping member that shapes the strip coil into an arc shape by having the shaping member hold the strip coil being transported by the coil transport mechanism between itself and the guide member, in a region including the rotation start position, such that the entirety of each of the side ends is contained within its own sliding contact surface, and the end of the sliding contact surface in the direction of transport is sandwiched between the fulcrum of the side end, which is the fulcrum of the portion of the piece member constituting the coil transport mechanism where the strip coil is supported at the bottom of the groove, and the fulcrum of the portion of the coil conductor where the strip coil is supported by another coil conductor located directly below it and overlapping and intersecting, and which generates a force in the opposite direction to the direction of the force the strip coil receives at the two fulcrums, such that the shaping member holds the strip coil in an arc shape so that the shaping member holds the strip coil in an arc shape such that the shaping member holds the end of the sliding contact surface in the direction of transport, such that the shaping member holds the strip coil in an arc shape A coil forming apparatus comprising a coil winding jig having a plurality of comb-shaped grooves arranged radially from its own pivot axis, which rotates and winds the strip-shaped coil, which has been shaped by the shaping member, while inserting the plurality of straight portions into each of the plurality of comb-shaped grooves.

2. A coil transport process in which a strip-shaped coil having multiple straight sections and side ends connected to each end of the multiple straight sections is guided by a guide member to transport it in a predetermined rotating transport section, so as to trace a rotating trajectory from a rotating start position, A shaping step in which the strip coil being transported in the coil transport process is shaped into an arc shape by a shaping member having a sliding contact surface for the strip coil, sandwiching the entire side end of each strip coil between the shaping member and the guide member in a region including the rotation start position, so that the end of the sliding contact surface in the direction of transport is sandwiched between the fulcrum of the side end, which is the fulcrum of the portion where the strip coil is supported at the bottom of the groove of the conveying member that transports the strip coil, and the fulcrum of the portion of the coil conductor where the strip coil is supported by another coil conductor located directly below it and overlapping and intersecting, and which generates a force in the opposite direction to the direction of the force the strip coil receives at the two fulcrums, such that the fulcrum remains within the side end of each strip coil until each side end of the strip coil passes through the region of the sliding contact surface by the transport process, A coil forming method characterized by including a coil winding step of winding the strip-shaped coil that has been shaped in the shaping step by rotating a coil winding jig having a plurality of comb-shaped grooves provided radially from its own rotational axis, thereby inserting the plurality of straight portions into each of the plurality of comb-shaped grooves.

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