JP4973859B2 - Preliminary forming method for polygon coil and forming method for annular winding coil having meandering portion using pre-formed polygon coil - Google Patents

Description

  The present invention relates to a method for preforming a meandering annular winding coil used for a stator winding of an electric motor (motor) and a method for forming an annular winding coil having a meandering portion using a preformed polygonal coil.

  As a motor for a hybrid vehicle or a motor for an electric vehicle, a permanent magnet type AC synchronous motor or a brushless DC motor using a permanent magnet as a rotor is often used. This type of motor includes a stator in which a winding coil is wound around a stator core for each of three phases including a U phase, a V phase, and a W phase, and a rotor composed of permanent magnets is driven by this stator in a three-phase manner. A permanent magnet type three-phase synchronous motor is known from, for example, Japanese Patent Application Laid-Open No. H10-228707. In addition, the winding coil was wound in a wave shape by winding the winding coil for each of the three phases including the U phase, the V phase, and the W phase so as to sew between adjacent teeth in the circumferential direction. For example, Patent Document 2 discloses a permanent magnet type three-phase synchronous motor that includes a stator and drives the rotor in three phases by the stator.

  In the three-phase synchronous motor according to the above prior art, since winding coils for each of the three phases are necessary, it is difficult to suppress an increase in the number of parts required for the configuration of the stator. There arises a problem that a troublesome labor is required for the operation of winding the winding coil for each phase. In addition, in a stator in which a winding coil is wound by wave winding, it is difficult to improve the winding occupancy between adjacent teeth, and further, the height of the coil end is reduced to reduce the motor axis. There arises a problem that it is difficult to reduce the size of the direction and improve the mountability to a vehicle or the like. In order to solve these problems, the present applicant alternately arranges three-phase stator rings and two-phase annular winding coils so as to be sequentially stacked along the axial direction. A motor stator in which a plurality of meandering portions are formed in a coil to increase the magnetic flux generated by the stator has been proposed (see Patent Document 3).

The stator of a permanent magnet type three-phase synchronous motor or DC brushless motor according to the above-mentioned prior application has not been generally used in the past, and therefore, in the situation where establishment of the processing method is desired, the present application is applied. A person previously proposed the invention of Patent Document 4. The present invention is an annular winding coil molding machine having a plurality of meandering portions arranged in a stator of an electric motor, and a plurality of first golds spaced at equal intervals in the circumferential direction as shown in FIG. A plurality of second molds 25 which are spaced apart from the first mold unit 12 having the mold 19 at the same intervals in the circumferential direction and are arranged between the adjacent first molds. Each of the second molds has a coil holding part 5 for holding the annular winding coil 1, and the annular winding held by the coil holding part 5. Coil diameter reducing means (cam surfaces 23, 28) for reducing the annular winding coil 1 in the radial direction according to the axial displacement of the first mold unit 12 with respect to the wire coil 1 is provided in the first metal mold. The mold unit 12 and the second mold unit 13 are provided respectively.
JP 11-299137 A "Motor Stator" Released on October 29, 1999 JP 2002-165396 A “Vehicle AC Generator” Released on June 7, 2002 JP 2006-280188 A “Stator and Motor” Published on October 12, 2006 Japanese Patent Application No. 2007-119376 “Meandering annular winding coil molding machine and serpentine annular winding coil molding method”

When forming a meandering annular winding coil using the meandering annular winding coil molding machine of the present invention, a perfect circle coil is used as shown in the upper part of FIG. When the annular coil provided with the meandering part is press-molded, the central part of the meandering coil has a slightly larger diameter and the coil side surface tends to swell like a drum. If the body swells like a drum, the coil will easily interfere with the rotor and stator ring, and when the coil is re-pressed for shaping, it will be difficult to fit into the mold, and the copper wire coating will be broken during pressing. Defects such as becoming easier occur.
An object of the present invention is to solve such a problem, that is, to present a technique in which a wave-shaped protrusion does not become a drum shape when a meandering annular winding coil is formed by pressing.

The preformed polygonal coil according to the present invention includes an annular winding coil having a plurality of meandering portions arranged in a stator of an electric motor, a first mold unit composed of a plurality of first molds, and a coil holding portion. A second mold unit comprising a plurality of second molds, and a mold moving means for allowing the first mold and the second mold to move in a substantially radial direction according to the relative distance between the two units. And forming the plurality of meandering portions while reducing the coil diameter of the annular winding coil before molding by the cooperation of the first mold unit and the second mold unit. A method for preforming a polygonal coil used for forming an annular winding coil having a plurality of meandering portions, wherein the annular annular winding coil initially formed in a substantially annular shape is used as the plurality of second molds. And move the plurality of second molds in the diameter increasing direction. It not expanded molded circular loop winding coils radially so, it was preformed method of substantially polygonal annular with a linear side portion by expanding the diameter and diameter shaping.
In addition to the above-described configuration, the pre-formed polygonal coil of the present invention has a size substantially equal to the radius of curvature of the non-meandering portion of the annular winding coil having the meandering portion that is the shape to be formed. It was set as the method of preforming to the thing provided with the vertex part of the substantially arc-shaped shape which has a curvature radius.

  The method for forming an annular winding coil having a plurality of meandering portions using a pre-formed polygonal coil according to the present invention is the same as that of the substantially polygonal annular winding coil formed by the above-described pre-forming method. The plurality of side portions are formed into a plurality of meandering portions while reducing the diameter by cooperation of the mold unit and the second mold unit.

As the annular winding coil before molding, the substantially polygonal annular winding coil of the present invention molded from a ring-shaped annular winding coil has a substantially linear shape by molding each side portion into the plurality of meandering portions. Since the sides can be bent straight down (or bent up), the influence of the arc shape of the ring-shaped coil is not brought into the height of the meandering portion, and the meandering coil is less likely to be formed in a drum shape. .
In the preforming method of the meandering annular winding coil according to the present invention, the substantially polygonal apex portion is moved from the annular annular winding coil by moving the second mold on which the annular annular winding coil is placed in the diameter increasing direction. Since the second mold is formed in the diameter expansion direction and the side portion is pulled by the formation of the apex portion and is naturally formed in the diameter reduction direction, the ring-shaped annular winding coil is substantially expanded with little expansion and contraction. It becomes possible to form a square annular winding coil.
In addition, since the apex portion of the substantially arc shape having a radius of curvature substantially equal to the radius of curvature of the non-meandering portion of the annular winding coil having the meandering portion which is the shaping target shape is formed, the shaping of the subsequent meandering portion is performed. Sometimes it is not necessary to rework the non-meandering portion again.
The method of forming a meandering annular winding coil using the polygonal coil of the present invention makes it difficult to form the meandering winding coil in a drum shape, so that the diameter of the meandering winding coil can be kept within a stable dimension. Become.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. However, since the stator itself incorporating the meandering annular winding coil according to the present invention is not well known, Before describing the embodiment, the structure of the stator will be described with reference to FIG. 8 and a method for processing the meandering annular winding coil will be described. The annular stator 30 constitutes a permanent magnet type AC synchronous motor or a DC brushless motor mounted on a hybrid vehicle as a vehicle drive source together with the engine, for example, and has, for example, a structure in which an engine, a DC brushless motor, and a transmission are connected in series. In the parallel hybrid vehicle, at least the driving force of either the engine or the DC brushless motor is transmitted to the driving wheels of the vehicle via the transmission. Further, when the driving force is transmitted from the driving wheel side to the DC brushless motor during deceleration of the vehicle, the DC brushless motor functions as a generator to generate a so-called regenerative braking force, and the kinetic energy of the vehicle body is converted into electric energy (regenerative energy). ). Furthermore, even when the output of the engine is transmitted to the DC brushless motor, the DC brushless motor functions as a generator and generates generated energy.

  In FIG. 8, A is a perspective view of the assembled stator 30, and B is an exploded perspective view of the annular stator 30 to which the meandering annular winding is mounted. As shown in FIG. 8, the annular stator 30 includes a U-phase stator ring (teeth ring) 31, a V-phase stator ring (teeth ring) 32, a W-phase stator ring (teeth ring) 33, and a U-phase annular coil. 3 and a W-phase annular winding coil 4. The U-phase stator ring 31 includes a plurality (10 in this embodiment) of U-phase teeth (U-phase claw balls) 34 spaced apart at equal intervals in the circumferential direction and a plurality of U-phase stator rings 31 spaced apart in the circumferential direction. A coupling portion 37 is provided. Each U-phase tooth 34 protrudes on one side in the axial direction (right side in FIG. 8). The V-phase stator ring 32 has a plurality (ten in this embodiment) of V-phase teeth 35 spaced apart at equal intervals in the circumferential direction and a plurality of coupling portions 38 spaced apart in the circumferential direction. . Each V-phase tooth 35 protrudes on both sides in the axial direction. The W-phase stator ring 33 has a plurality (10 in this embodiment) of W-phase teeth 36 spaced apart at equal intervals in the circumferential direction and a plurality of coupling portions 39 spaced apart in the circumferential direction. Each W-phase tooth 36 projects to the other side in the axial direction (left side in FIG. 8). That is, the U-phase teeth 34 and the W-phase teeth 36 protrude in a direction approaching each other.

  It should be noted that the U-phase teeth 34, the V-phase teeth 35, and the W-phase teeth 36 are respectively connected to the U-phase stator ring 31, the V-phase stator ring 32, and the W-phase stator ring 33 at the respective connecting portions 37, 38, and 39. When stacked and bonded, they are arranged at positions that are relatively shifted so as not to overlap each other. The U-phase annular winding coil 3 is formed by winding a conducting wire in an annular shape, and has a plurality (10 in this embodiment) meandering portions 40 meandering in the axial direction of the stator 30. Similarly, the W-phase annular winding coil 4 also has a plurality (ten in this embodiment) of meandering portions 41 meandering in the axial direction of the stator 30. The connecting portions 37, 38, 39 of the stator rings 31, 32, 33 are aligned, the U-phase annular winding coil 3 and the W-phase annular winding coil 4 are arranged at predetermined positions in the circumferential direction, and the respective stator rings 31 are arranged. , 32, 33 are bolted and fixed, and an annular stator 30 as shown in FIG.

  As is apparent from FIG. 8, the teeth 34, 35, 36 of each stator ring are in a predetermined order in the circumferential direction (U-phase teeth 34, W-phase teeth 36, V-phase teeth 35, U-phase teeth 34,...). The meandering portion 40 of the U-phase annular winding coil 3 is arranged between the teeth 34 and 35 adjacent in the circumferential direction, and the W-phase annular winding coil 4 is meandering between the teeth 35 and 36 adjacent in the circumferential direction. Part 41 is arranged. That is, one U-phase tooth 34 is disposed in the U-phase meandering portion 40, and one W-phase tooth 36 is disposed in the W-phase meandering portion 41, and the U-phase meandering portion 40 and the W-phase meandering that are adjacent in the circumferential direction. One V-phase tooth 35 is arranged between the portion 41. The meandering portion 40 of the U-phase annular winding coil 3 and the meandering portion 41 of the W-phase annular winding coil 4 are provided so as to protrude in different directions, and the U-phase annular winding coil 3 and the W-phase annular winding coil are provided. 4 is arranged at a position relatively shifted in the circumferential direction so as to have a phase difference of 240 ° in electrical angle. Thus, the two-phase annular winding coils 3 and 4 arranged so as to sew between the teeth 34 and 35 adjacent to each other in the circumferential direction or between the teeth 35 and 36 have a so-called electrical angle of 120 ° or less. Is formed.

  Next, a method for forming the meandering portion 40 of the U-phase annular winding coil 3 and the meandering portion 41 of the W-phase annular winding coil 4 (the technique of Patent Document 4) will be described. An example of the molding machine used is shown in FIG. This figure is a cross-sectional view of the upper die unit 12 and the lower die unit 13 before processing. The base of the upper die unit 12 has a plurality of (in this embodiment, 10) metal molds spaced apart from each other at equal intervals in the circumferential direction. The mold support 14 is fixed. A guide rail 17 is attached to each mold support portion 14 by a pair of brackets 15 and 16. A slider 18 is attached along the guide rail 17 so as to be slidable in the radial direction of the perfect circular coil 1 to be formed into the annular coil 3 (4). Each slider 18 is provided with a first die 19 having a pressing portion 20 for forming a perfect circular coil 1 and a rotatable roller 21. The roller 21 rolls on a cam surface 28 formed on the roller guide 27 of the lower mold unit 13 as the upper mold unit 12 and the lower mold unit 13 approach each other. In the example shown in the drawing, the upper mold unit 12 has ten molds 19 that are spaced apart from each other at equal intervals in the circumferential direction, and a plurality of (in this example, a plurality of molds 19 disposed in the middle of the first mold 19). Ten roller guides 22 are fixed. A curved cam surface 23 is formed at the tip of each roller guide 22.

  To the base of the lower mold unit 13, a plurality (10 in this example) of mold support portions that are spaced apart at equal intervals in the circumferential direction are fixed. Each die support portion is provided with a guide rail 24 so that the circular ring coil 1 in which the second die 25 is set can slide along the guide rail 24 in the radial direction. It is attached. Each second mold 25 includes a mold base (coil holding portion 5) that can slide along the guide rail 24 and a coil pressing member 29. A roller 26 is rotatably attached to the mold base via a pair of brackets. Since the rollers 26 of each second mold 25 are adapted to roll on the cam surface 23 of the roller guide 22 provided in the upper mold unit 12, each second mold 25 is 36 ° in the circumferential direction. It is spaced apart and is arranged in the middle in the circumferential direction of the adjacent first molds 19. The lower die unit 13 is further fixed with a plurality of (in this example, 10) roller guides 27 which are spaced apart at equal intervals in the circumferential direction and are arranged in the middle in the circumferential direction of the adjacent second mold 25. Has been.

  The method of forming the annular winding coil by the above-described annular winding coil forming machine will be described. First, a perfect circular annular coil 1 is used as a mold base (coil holding portion 5) of each second mold 25 of the lower mold unit 13. And is held by the coil holding member 29. From this state, the upper die unit 12 is lowered to start forming the perfect circular coil 1. At the start of the molding process, the roller 21 of the upper mold unit 12 comes into contact with a substantially linear portion where the cam surface 28 of the roller guide 27 of the lower mold unit 13 is steeply inclined, and the roller 26 of the lower mold unit 13 is Since the cam surface 23 of the roller guide 22 of the unit 12 is in contact with the substantially linear portion where the inclination is steep, the circular annular coil 1 is slightly slightly in the radial direction in the initial stage of the molding process. It is only reduced. When the upper die unit 12 further moves in the axial direction, the roller 21 rolls on the arc-shaped portion of the cam surface 28, and the roller 26 rolls on the arc-shaped portion of the cam surface 23. When the amount of reduction in the radial direction of the circular coil 1 having a perfect circle shape gradually increases with respect to the amount of displacement, and further pressing proceeds, the roller 21 rolls on a substantially linear portion where the cam surface 28 has a gentle inclination. Since the roller 26 rolls on a substantially linear part where the inclination of the cam surface 23 is gentle, the upper die unit 12 and the lower die for forming the meandering portion 40 (41) from the perfect circular coil 1 The radial displacement amounts of the first mold 19 and the second mold 25 with respect to the relative displacement amount in the axial direction of the unit 13 generally draw a curve as a whole. Thus, by adopting the specially-shaped curved cam surfaces 23 and 28, the ratio of the radial displacement amount of the perfect circular ring coil 1 to the axial displacement amount of the perfect circular coil 1. Can be continuously changed, so that a plurality of meandering portions 40 (41) can be easily and automatically formed in the perfect circular ring coil 1 without applying excessive stress to the perfect circular ring coil 1. can do.

As shown in FIG. 1, the annular winding coil using the polygonal coil of the present invention does not directly press the ring-shaped annular winding coil 1 that is a perfect circle, but first, it is formed into a substantially polygonal shape. Preliminary processing is performed, and the form which presses it is taken.
The ring-shaped annular winding coil may be the perfect circular coil 1 shown in FIG. 1, or may be somewhat irregular or substantially annular.
As shown in FIG. 9A, the perfect circular annular coil 1 is provided with a cylindrical body 42 having axial grooves. A conducting wire 44 is wound around the cylindrical body 42 to form, for example, five rows and two layers of a perfect circular coil 1. 45 is a coil start end, and 46 is a coil end end. In this way, after winding the conducting wire 44 around the cylindrical body 42 to form an annular winding group, a binding band is inserted into the groove 43 and the annular winding group is bound to form a perfect winding coil shape Is molded. Thereafter, a jig is inserted to remove the coil from the cylindrical body 42 (see FIG. 9B). Then, as shown in FIG. 9 (C), the coil start end 45 and the coil end end 46 are formed, and the perfect circular winding coil 1 is completed.

  This perfect circular winding coil 1 is deformed to form a desired number of corners and sides between the corners. The part which becomes a corner from the inner side of the coil is spread outward, and the part which becomes a side is naturally shrunk from the outside toward the center as each corner is processed. In this processing, the coil is stretched and balanced so that no stretching force is applied to the coil. As shown in FIG. 2, this preliminary processing is performed by making the second mold independent of the press forming of the meandering portion (regardless of the cam mechanism of the roller guide 22, the cam surface 23, and the roller 26 in FIG. 7). This is done on a press molding machine equipped with a lower die unit that can move in the direction of the scale. In this lower mold unit, a coil holding part 5 having a plurality of grooves 5a is annularly arranged at an angular position corresponding to a polygonal corner, and the coil holding part 5 is a mechanism that can be moved in the radial direction by a servo motor 6. ing. In place of the servo motor 6, driving means such as an air cylinder may be used. The initial groove position is set to the radial dimension position of the circular ring-shaped coil 1 having a perfect circle shape, and the circular ring-shaped coil 1 that is a workpiece is set to the groove section. When the annular winding coil 1 is set, the groove 5a is covered with a lid (not shown) so that the annular winding coil 1 is not detached. Next, when the coil holding part 5 is moved radially outward, the inner side wall surface of the groove 5a presses to expand the coil. The inner side wall surface of the groove 5a is formed in an arc shape having a radius R of the annular coil 3 (4) having a meandering portion. When the coil is pressed within a range where the coil does not extend, the coil in the portion in contact with the inner surface has a radius R. And is formed into a substantially polygonal shape that is a substantially linear side between adjacent corners. This is shown in FIGS. 3 and 6 as a pre-processed substantially polygonal coil 2.

  The pre-processed substantially polygonal annular coil 2 is subjected to press processing for forming a meandering portion, and this processing is composed of a plurality of first dies 19 as in the technique of Patent Document 4 above. An upper mold unit 12, a lower mold unit 13 comprising a plurality of second molds 25 provided with a coil holding part 5, and the first mold 19 and the second mold according to the relative distance between the two units. This is performed by using a meandering annular winding coil forming apparatus provided with a mold moving means for making 25 movable in a substantially radial direction. Then, a plurality of meandering portions 40 (41) are formed while the coil diameter of the substantially polygonal annular coil 2 before molding is reduced by the cooperation of the upper mold unit 12 and the lower mold unit 13. The annular winding coil 3 (4) having the meandering portion 40 (41) is formed. However, the diameter reduction drive of the mold is performed by a drive mechanism using a cam surface and a roller that rolls on the surface in Patent Document 4, but in the present invention, the lower mold at the time of the pre-processing of the annular ring coil is preferable. The same drive mechanism as that of the unit may be used, but a drive mechanism such as a cam for reducing diameter driving, a servo motor, an air cylinder, etc. may be provided separately. (In this embodiment, it is assumed that the control system using the same servo motor 6 as in the pre-processing is used.) The coil holding unit and the servo motor driving mechanism used in the pre-processing are used as the coil holding unit as it is, and the second gold The mold 25 can also be used as a mold moving means that allows the mold 25 to move in a substantially radial direction. Since it is a control system using the servo motor 6, it can be driven in any manner according to the program design, and the versatility is remarkably improved compared to the cam drive. By this pressing, an annular coil 3 (4) having a meandering portion as shown in a perspective view in FIG. 4 is formed. The radius (the width center of the coil bundle) of the annular coil 3 (4) having the meandering portion is R as shown in FIG. 3, and the curvature of the non-meandering portion is the groove of the coil holding portion at the time of preliminary processing as described above. The inner wall surface is preferably formed in an arc shape having a radius R. The groove inner wall surface (arc-shaped surface) is set to be appropriately smaller than the radius R. The deformation by the preliminary processing is performed by a pressing force in the radial direction, and the meandering portion is formed by press processing in which the upper mold unit 12 and the lower mold unit 13 are relatively displaced in an axial direction perpendicular thereto. Since this press working is performed on the portion that has been formed into a substantially polygonal side portion by the preliminary processing, the side surface shape of the meandering portion can be prevented from becoming a drum shape.

If the annular coil having meandering portions formed by pressing is not finished in the designed shape such as a drum swells in a drum shape, the coil tends to interfere with the rotor and the stator ring. Therefore, a secondary press process is finally performed for shaping. As shown in FIG. 5, the secondary pressing is performed by using a mold 11 composed of an inner diameter frame and an outer diameter frame, and fitting into the mold 11 for press shaping. However, if it is not finished in the shape as designed, it will be difficult to fit in the mold 11, and if it is pressed in a state that does not fit neatly, problems such as breaking the coil conductor coating will occur. As described above, when the annular coil 2 having a substantially polygonal shape by preliminary processing according to the present invention is used, the tendency of the drum portion of the annular coil 3 (4) having the meandering portion to swell in a drum shape is small. The fit in the mold 11 is good and there is no hindrance such as breakage of the coil conductor coating. FIG. 5A includes an upper mold unit 9 having upper molds 9a and 9b, and a lower mold unit 10 having lower molds 10a and 10b in an inner diameter frame and an outer diameter frame. A secondary press molding machine for shaping is shown before the annular coil 3 (4) having a meandering portion is set for shaping. As shown in FIG. 5B, the annular coil 3 (4) is set in the inner and outer diameter frames of the lower mold unit 10, and then the upper molds 9a and 9b are set as shown in FIG. When the upper mold unit 9 provided with is lowered and pressed, the annular coil 3 (4) having the meandering portion is shaped into a desired shape by being pressed between the upper and lower molds.
In this embodiment, the second mold 25 is installed as the lower mold unit 13 on the lower side of the press. However, the second mold 25 may be replaced with the upper mold unit, or in the case of using a horizontal stroke press. You may change the position to set suitably, such as setting a 2nd mold unit in the side.

It is a conceptual diagram explaining the preforming process of this invention. It is a figure which shows one example of the apparatus which shape | molds the polygonal coil of this invention. It is a figure which shows the relationship between the polygon coil preformed by this invention, and the cyclic | annular coil which has a meandering part. It is a perspective view of the annular coil which has the meander part shape | molded from the polygon coil preformed by this invention. It is a figure explaining the method of shaping the annular coil which has the meandering part shape | molded from the polygon coil preformed by this invention. It is a figure which shows the shape of the polygon coil formed by each said shaping | molding apparatus. It is a figure explaining 1 method of shape | molding the annular coil which has a meandering part. It is a figure explaining the structure of the annular coil which has a meandering part. It is a figure explaining the method of forming a perfect circular annular coil.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Perfect circular coil 2 Substantially polygonal annular coil 3, 4 Ring coil which has a meander part 5 Coil holding part
5a Groove 6, 7 Servo motor 8 Side forming mold 8a Reverse curvature mold
8b Loose curvature mold 9 Upper mold unit for shaping
9a, 9b Upper mold for shaping 10 Lower mold unit for shaping
10a, 10b Lower mold for shaping 11 Mold for shaping
12 Upper mold unit for molding 13 Lower mold unit for molding
14 Each mold support 15, 16 Bracket
17 Guide rail 18 Slider
19 First mold 20 Holding part
21 Roller 22 Roller guide
23 Cam surface 24 Guide rail
25 Second mold 26 Roller
27 Roller guide 28 Cam surface
30 Stator 31 U-phase stator ring
32 V-phase stator ring 33 W-phase stator ring
34 U-phase teeth 35 V-phase teeth
36 W phase teeth 37, 38, 39 joint
4, 41 Meandering part 42 Cylindrical body
43 Axial groove 44 Conductor
45 Coil start 46 Coil end

Claims (3)

  An annular winding coil having a plurality of meandering parts arranged in a stator of an electric motor is composed of a first mold unit comprising a plurality of first molds and a plurality of second molds provided with coil holding parts. A meandering coiled coil forming apparatus comprising: a second mold unit; and a mold moving means that enables the first mold and the second mold to move in a substantially radial direction according to the relative distance between the two units. An annular winding coil having a plurality of meandering portions that form the plurality of meandering portions while reducing the coil diameter of the annular winding coil before molding by the cooperation of the first mold unit and the second mold unit. A method for preforming a polygonal coil used for forming a ring-shaped coil, wherein a ring-shaped annular winding coil that is initially formed in a substantially annular shape is placed on the plurality of second molds, and the plurality of second gold Move the mold in the radial direction to move the annular ring coil in the radial direction It-diameter no shape, preforming method to polygons coil, characterized in that it has a substantially polygonal annular with a linear side portion by expanding the diameter and diameter shaping.   The substantially polygonal ring has a substantially arcuate apex having a radius of curvature substantially equal to the radius of curvature of the non-meandering portion of the annular winding coil having the meandering portion which is the shaping target shape. The preforming method to the polygonal coil as described in 2.   A substantially polygonal annular coil formed by the preforming method for a polygonal coil according to claim 1 or 2 while reducing the coil diameter by cooperation of the first mold unit and the second mold unit. A method for forming an annular winding coil having a plurality of meandering portions using a pre-formed polygonal coil, wherein the plurality of side portions are formed into a plurality of meandering portions.

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