Coil segment manufacturing device and method

Abstract

To provide a manufacturing method for a coil segment that enables the shape of the coil segment to be set with higher accuracy.SOLUTION: In a manufacturing method for a coil segment 3 formed by bending a wire W, the other side Wc of a wire W is displaced relatively in a first direction with respect to one side Wa of the wire W to bend the wire W between the one side Wa and the other side Wc, and the other side Wc of the wire W is displaced relatively in a second direction opposite to the first direction with respect to the one side Wa of the wire W to bend back the wire W between the one side Wa and the other side Wc.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an apparatus and method for manufacturing a coil segment used in a stator coil of a rotating electrical machine. [Background technology]

[0002] Patent Document 1 describes a conventional coil segment manufacturing device.

[0003] In this manufacturing apparatus, as shown in FIG. 11, the middle portion of the wire W is held by forming dies 105 and 107, and forming rollers 109 and 111 are lowered along a side surface 105a of the forming die 105 to form a coil segment having a folded-back shape.

[0004] In this forming, taking into consideration the springback of the coil segment, the shape of the coil segment is set so that it gradually approaches the end of the wire W. The shape of the coil segment can be set by pressing the wire W against the inclined side surface 105a of the forming die 105 with forming rollers 109 and 111.

[0005] However, since the amount of springback of the coil segments is not constant, there is a risk of variation in the shape of the coil segments, and therefore there is a need for a method for setting the shape of the coil segments with higher accuracy. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2004-297863 A Summary of the Invention [Problem to be solved by the invention]

[0007] The problem to be solved is that there is a need for more accurate setting of the shape of the coil segments. [Means for solving the problem]

[0008] The present invention provides a manufacturing method for a coil segment formed by bending a wire, which comprises displacing one side of the wire relative to the other side in a first direction to bend the wire between the one side and the other side, and displacing the other side of the wire relative to the one side in a second direction opposite to the first direction to bend back the wire between the one side and the other side.

[0009] The present invention also provides a manufacturing apparatus for a coil segment formed by bending a wire, the manufacturing apparatus comprising: a displacement unit which displaces one side of the wire relative to the other side in a first direction; and a bending-back unit which displaces the other side of the wire relative to the one side in a second direction opposite to the first direction, wherein the displacement unit displaces the other side of the wire in the first direction to bend the wire between the one side and the other side, and the bending-back unit displaces the other side of the wire in the second direction to bend back the wire between the one side and the other side. Effect of the Invention

[0010] The present invention enables the shape of the coil segments to be set with higher accuracy. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a front view showing a coil segment according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of the coil segment of FIG. [Diagram 3] FIG. 3 is a schematic front view showing the coil segment manufacturing apparatus according to the first embodiment. [Figure 4] FIG. 4 is a schematic front view of the manufacturing apparatus showing a state in which the wire material according to the first embodiment is placed between the first die and the second die. [Diagram 5] FIG. 5 is a schematic front view of the manufacturing apparatus showing a state in which the intermediate portion of the wire in FIG. 4 is sandwiched between a first die and a second die and molded. [Figure 6] FIG. 6 is a schematic front view of the manufacturing device when bending the end portion of the wire in FIG. [Figure 7] FIG. 7 is a schematic front view of the manufacturing device when bending back the end portion of the wire rod in FIG. [Figure 8] FIG. 8 is a plan view showing a part of a coil segment manufacturing apparatus according to Example 2 of the present invention. [Figure 9] FIG. 9 is a schematic front view of the manufacturing apparatus showing a state in which the wire material according to the second embodiment is placed between the first molding die and the second molding die. [Figure 10] FIG. 10 is a schematic front view of the manufacturing apparatus when bending back the other side portion of the wire rod in FIG. [Figure 11] FIG. 11 is a perspective view showing a conventional segment coil manufacturing device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The goal of enabling more precise setting of the shape of the coil segments was achieved by bending the wire and then bending it back.

[0013] The manufacturing method of the coil segment is to displace one side of the wire W in a first direction relative to the other side to bend the wire W between the one side and the other side, and then to displace the other side of the wire W in a second direction opposite to the first direction relative to the one side to unbend the wire W between the one side and the other side.

[0014] The amount of displacement for bending back can be set appropriately, but is preferably smaller than the amount of displacement for bending.

[0015] The coil segment 3 may have a configuration in which a pair of legs 7 are arranged side by side via a folded portion 5. In this case, one side of the wire W may be one side Wa or Wc which is one of the folded portion 5 and the leg 7, and the other side of the wire W may be the other side Wc or Wa which is the other of the folded portion 5 and the leg 7. In another embodiment, one side of the wire W may be one side Wo of the portion Wa which is the folded portion 5, and the other side of the wire W may be the other side Wt of the portion Wa which is the folded portion 5.

[0016] The bending and unbending method may be any suitable method such as pressing one side or the other side of the wire W or displacing it in a gripped state.

[0017] In the above embodiment, the wire W may be bent by gripping the intermediate portion Wa of the wire W that becomes the folded portion 5 and pressing in the first direction the end portion Wc that becomes the leg portion 7 located closer to the end portion Wb than the intermediate portion Wa of the wire W. In this case, the end portion Wc may be pressed in the second direction to bend back.

[0018] In the other embodiment described above, the intermediate portion Wa of the wire W that becomes the folded-back portion 5 may be pressed to perform folding between one side portion Wo and the other side portion Wt of the intermediate portion Wa. In this case, after pressing, one of the one side portion Wo or the other side portion Wt is held to bend back the other of the one side portion Wo or the other side portion Wt.

[0019] The manufacturing device 1 for the coil segment 3 includes a displacement section 11 and an unbending section 13 .

[0020] The displacement portion 11 displaces one side of the wire W in a first direction relative to the other side of the wire W. Due to this displacement, the wire W is bent between the one side and the other side so that the other side of the wire W is located at a first position.

[0021] The unbending portion 13 displaces one side of the wire W in a second direction opposite to the first direction relative to the other side of the wire W. Due to this displacement, the wire W is unbent between the one side and the other side such that the other side of the wire W is positioned at a second position closer to the first position in the first direction than the initial position before bending.

[0022] In an embodiment in which one side of the wire W is one side portion Wa or Wc which becomes one of the fold-back portion 5 and the leg portion 7, and the other side of the wire W is the other side portion Wc or Wa which becomes the other of the fold-back portion 5 and the leg portion 7, the manufacturing apparatus 1 may be provided with a gripping portion 9.

[0023] The gripping portion 9 grips an intermediate portion Wa of the wire W which becomes the folded-back portion 5. In this case, the displacement portion 11 may press an end portion Wc of the wire W in a first direction to perform bending, and the unbending portion 13 may press the end portion Wc in a second direction to perform bending.

[0024] In an embodiment in which one side of the wire W is one side part Wo of the middle part Wa and the other side of the wire W is the other side part Wt of the middle part Wa, the displacement part 11 of the manufacturing apparatus 1 may include a forming die .

[0025] The forming die 23 forms the folded portion 5 by pressing, and performs folding between one side portion Wo and the other side portion Wt of a pair of legs 7 of the folded portion 5. The bending back unit 13 holds one of the one side portion Wo or the other side portion Wt after pressing, and bends back the other of the one side portion Wo or the other side portion Wt. EXAMPLES

[0026] [Coil segment] FIG. 1 is a front view showing a coil segment according to a first embodiment of the present invention, and FIG. 2 is a plan view of the same.

[0027] 1 and 2 is manufactured by the manufacturing apparatus 1 and method of the present embodiment. A plurality of coil segments 3 are combined to form a coil of a stator (not shown). The stator, together with a rotor (not shown), constitutes a rotating electric machine.

[0028] The coil is made up of multiple coil segments 3 arranged in an annular shape around the stator core, and is wound in a wave shape with multiple layers in the radial direction of the core. Each coil segment 3 is formed by bending a wire rod W, which is a flat wire with a rectangular cross section. The cross-sectional shape of the wire rod W is not particularly limited.

[0029] The coil segment 3 is folded to have a folded shape, for example a U-shaped hairpin shape, and includes a folded portion 5 and a pair of legs 7.

[0030] The folded portion 5 is located on one side in the length direction of the coil segment 3, and has an inclined shape so as to gradually displace toward the other side in the length direction toward the outside in the width direction relative to the apex portion 5a. The length direction is the direction along the length of the coil segment 3 from the apex portion 5a of the folded portion 5 to the tip of the leg portion 7. The width direction is the direction along the width of the coil segment 3 that the leg portion 7 faces.

[0031] The apex 5a of the folded portion 5 is bent in a crank shape in the thickness direction. The thickness direction is a direction along the thickness of the coil segment 3 that is perpendicular to the length direction and the width direction.

[0032] The leg portion 7 extends from the folded portion 5 toward the other side in the length direction. The leg portion 7 is aligned along the length direction, but may be inclined with respect to the length direction. In this embodiment, the shape of the coil segment 3 due to the inclination of the leg portion 7 is set by the manufacturing device 1 and method.

[0033] [Coil segment manufacturing equipment] FIG. 3 is a schematic front view showing the manufacturing apparatus 1 for the coil segment 3 according to the first embodiment.

[0034] As shown in Fig. 3, the coil segment manufacturing apparatus 1 bends a wire rod W of a predetermined length to form a folded-back coil segment 3. Note that the coil segment 3 in Fig. 3 shows a state in which the wire rod W has been folded and formed, but before being unbent.

[0035] Although this coil segment 3 is not strictly a completed coil segment 3, for the sake of convenience, the wire W and the coil segment 3 are indicated at the same time, and the coil segment 3 is indicated in parentheses.

[0036] The manufacturing apparatus 1 includes a gripping unit 9, a displacement unit 11, and a bending back unit 13. The manufacturing apparatus 1 is controlled by a controller consisting of a computer (not shown).

[0037] The gripping portion 9 grips one side or the other side of the wire W. One side of the wire W is one side that becomes one of the folded-back portions 5 and leg portions 7 of the coil segment 3, and the other side of the wire W is the other side that becomes the other of the folded-back portions 5 and leg portions 7 of the coil segment 3.

[0038] In this embodiment, the gripping portion 9 grips the middle portion Wa of the wire W, which becomes the folded portion 5 of the coil segment 3, as one side of the wire W. The gripping portion 9 may have any structure as long as it can grip the wire W. The gripping portion 9 in this embodiment is configured with a first die 9a and a second die 9b. The middle portion Wa of the wire W corresponds to the folded portion 5 of the formed coil segment 3 and refers to the portion sandwiched between the first and second dies 9a and 9b.

[0039] The first die 9a and the second die 9b sandwich the middle portion Wa and bend it, and press-form the folded-back portion 5. Note that, in Fig. 3, for ease of understanding, there are gaps between the wire material W and the first die 9a and the second die 9b, but in reality, there is no gap between the wire material W and the first die 9a and the second die 9b and they are in close contact with each other.

[0040] In this embodiment, the first die 9a is a lower die for pressing, and the second die 9b is an upper die for pressing. However, the first die 9a and the second die 9b may only grip the middle part Wa of the wire W without processing it. In this case, the gripping part 9 is not limited to the first die 9a and the second die 9b, as long as it can grip the middle part Wa.

[0041] Note that up and down refers to up and down in the pressing direction of the first die 9a and the second die 9b, and left and right refers to up and down in the pressing direction, and refers to left and right when the manufacturing apparatus 1 is viewed from the front of FIG.

[0042] An upper surface 14 of the first die 9a and a lower surface 16 of the second die 9b are processing surfaces on which press processing is performed, and each corresponds to the shape of the folded-back portion 5 of the coil segment 3. Although the central portions of the upper surface 14 and the lower surface 16 are flat, they are actually curved surfaces corresponding to the coil segment 3 in Figures 1 and 2. However, the central portions of the upper surface 14 and the lower surface 16 may also be flat as shown in Figure 3.

[0043] The first die 9a in this embodiment has a tip 15. The tip 15 comes into contact with an end portion Wc located on the end Wb side of the intermediate portion Wa of a predetermined length of wire W, and serves as a bending starting point. The end portion Wc of the wire W corresponds to the formed leg portion 7. The end portion Wb of the wire W corresponds to the tip 7a of the leg portion 7.

[0044] The tip 15 is formed between the side surfaces 17a and 17b and the side surfaces 19a and 19b of the first die 9a, respectively, and protrudes on both the left and right sides. The tip 15 has a pointed shape, but it can also be formed into other shapes, such as an arc shape or a rectangle. The tip 15 may be provided separately from the first die 9a, as long as it is provided at a position that contacts the wire W as a starting point for bending.

[0045] The displacement unit 11 displaces one side of the wire W relative to the other side in a first direction. As a result, the displacement unit 11 bends between the one side and the other side of the wire W so that the other side of the wire W is displaced in the first direction and positioned at a first position. The first position is a position on the other side of the wire W where the shape is bent more than the shape of the final product. The bending is performed by plastic deformation.

[0046] In this embodiment, the displacement portion 11 presses the end portion Wc in a first direction to bend it. The first direction is a rotation direction in which the end portion Wc moves close to the side surfaces 19a and 19b of the first die 9a around the point between the intermediate portion Wa and the end portion Wc of the wire W.

[0047] By this bending, the end portion Wc of the wire W is located at the first position as shown in Fig. 3. Therefore, the displacement portion 11 bends the wire W between the middle portion Wa and the end portion Wc such that the end portion Wc of the wire W is displaced in the first direction and located at the first position.

[0048] As long as the displacement unit 11 can displace the end portion Wc, any suitable mechanism, apparatus, device, etc. can be used. In this embodiment, the displacement unit 11 includes a roller 11a, and presses and displaces the end portion Wc.

[0049] The rollers 11a are provided corresponding to the left and right end portions Wc. Each roller 11a is attached to the lower end of a support rod 11b. The support rod 11b is connected to a drive mechanism such as an actuator (not shown) and is raised and lowered in the inclined direction.

[0050] The roller 11a moves up and down via the support rod 11b. As the roller 11a moves down, the intermediate portion Wa of the roller 11a comes into contact with the end portion Wc of the wire W being held, and presses it downward. This pressing force bends the wire W so that the end portion Wc gradually approaches the end Wb.

[0051] Moreover, the displacement portion 11 that presses the end portion Wc may be a non-rotating roller-shaped or block-shaped one instead of the roller 11a. The arrangement and number of the rollers 11a are free, and the end portion Wc may be pressed by a plurality of rollers 11a on one side. Alternatively, the rollers 11a may be arranged only on either the left or right side, and the end portion Wc may be bent on one side at a time.

[0052] The unbending section 13 displaces one side of the wire W relative to the other side in a second direction opposite to the first direction. As a result, the unbending section 13 bends back the area between one side and the other side of the wire W so that the other side of the wire W is displaced from the first position in the second direction to be located at the second position. The second position is the position of the other side of the wire W where the bent shape is the same as the shape of the final product. The unbending is performed by plastic deformation. It is preferable that the amount of displacement in the unbending is smaller than the amount of displacement in the bending.

[0053] In this embodiment, the unbending section 13 unbends the end portion Wc of the wire W by pressing it in the second direction. The second direction in this embodiment is a rotation direction in which the end portion Wc of the wire W moves away from the side surfaces 19a and 19b of the first die 9a around the point between the intermediate portion Wa and the end portion Wc of the wire W.

[0054] By this bending back, the end side portion Wc of the wire W is located at a second position closer to the first position in the first direction than the initial position before bending (see FIG. 7). Therefore, the displacement portion 11 bends back the portion between the middle portion Wa and the end side portion Wc of the wire W such that the end side portion Wc of the wire W is displaced in the second direction and located at the second position.

[0055] When bending back, the elastic limit becomes smaller than when bending due to the Bauschinger effect, so springback can be suppressed. The second position is a position where the end side portions Wc are approximately parallel.

[0056] As long as the end portion Wc can be displaced, any suitable mechanism, apparatus, device, etc., such as various linear motion mechanisms or robots, can be used for the unbending section 13. In this embodiment, the unbending section 13 has a pair of cylinder devices 21.

[0057] The cylinder device 21 is disposed below the first die 9a and is located between the end side portions Wc bent by the displacement portion 11. The cylinder device 21 may be disposed inside the first die 9a.

[0058] The cylinder device 21 has a movable part 21a that is movable in the width direction. The cylinder device 21 may have movable part 21a that is movable diagonally with respect to the left-right direction. The movable part 21a is made of resin or the like, and abuts against the end part Wc to press it in the second direction. The pressing direction of the movable part 21a is not the second direction strictly speaking, but it is defined as the second direction as the direction in which the end part Wc is moved by pressing.

[0059] The shape of the movable part 21a can be any shape that can press the end part Wc. The movable part 21a in this embodiment is a block shape that abuts against the end part Wc so that the end part Wc can slide up and down. The movable part 21a may have a groove that holds the end part Wc.

[0060] [Coil segment forming method] FIG. 4 is a schematic front view of the manufacturing apparatus 1 showing a state in which the wire W is placed between the first die 9a and the second die 9b.

[0061] In the manufacturing method of the coil segment 3 of this embodiment, first, as shown in Fig. 4, a wire W is placed between a first die 9a and a second die 9b. The wire W is a flat wire with a rectangular cross section cut to a predetermined length. The wire W is bent in advance at a middle portion Wa into a crank shape in a direction perpendicular to the paper surface of Fig. 4. This bending can be performed by a press or the like.

[0062] FIG. 5 is a schematic front view of the manufacturing apparatus 1, showing a state in which the intermediate portion Wa of the wire W in FIG. 4 is sandwiched between a first die 9a and a second die 9b and molded.

[0063] 5, the intermediate portion Wa of the wire W is sandwiched between the first die 9a and the second die 9b, and the intermediate portion Wa is formed. Through this forming, the intermediate portion Wa is bent along the upper surface 14 of the first die 9a and the lower surface 16 of the second die 9b.

[0064] FIG. 6 is a schematic front view of the manufacturing apparatus 1 when bending the end side portion Wc of the wire rod W in FIG.

[0065] 6, while keeping the middle portion Wa of the wire W sandwiched between the first die 9a and the second die 9b, i.e., while gripping the middle portion Wa, the roller 11a of the displacement unit 11 descends. By this descent, the roller 11a comes into contact with the end portion Wc of the wire W gripped between the first die 9a and the second die 9b, and then presses the end portion Wc downward.

[0066] As a result, the end portion Wc, which is the other side of the wire W, is displaced in the first direction relative to the middle portion Wa, which is the other side of the wire W. That is, the end portion Wc rotates in the first direction with the tip 15 as a starting point between the middle portion Wa and the end portion Wc. Then, when the roller 11a of the displacement portion 11 rides over the tip 15, the bending of the wire W between the middle portion Wa and the end portion Wc is completed.

[0067] The folded shape of the wire W after the bending is completed is set according to the amount of movement of the roller 11a in the left-right direction, and in this embodiment, the end portion Wc gradually approaches the end Wb. In this state, the end portion Wc is disposed at the first position.

[0068] FIG. 7 is a schematic front view of the manufacturing apparatus 1 when bending back the end portion Wc of the wire rod W in FIG.

[0069] As shown in FIG. 7, after the bending is completed, the roller 11a rises. When the roller 11a rises, the pressing force on the end portion Wc is released. Therefore, the end portion Wc of the wire W is displaced outward in the width direction due to springback. In this embodiment, even after the springback, the end portion Wc is inclined so as to gradually approach the end Wb.

[0070] Then, while keeping the intermediate portion Wa of the wire W sandwiched between the first die 9a and the second die 9b, the movable portion 21a of the cylinder device 21 of the unbending section 13 is moved outward in the width direction. By this movement, the movable portion 21a of the cylinder device 21 comes into contact with the end portion Wc of the wire W, and then presses the end portion Wc outward in the width direction.

[0071] As a result, the wire W is displaced in the second direction relative to the intermediate portion Wa, and the intermediate portion Wa and the end portion Wc of the wire W are bent back so that the end portion Wc is located at the second position.

[0072] When bending back, the elastic limit of the wire W becomes smaller due to the Bauschinger effect than when it is bent, so springback can be suppressed and the bent back end portion Wc can be positioned at the second position and made approximately parallel.

[0073] In addition, the amount of displacement of the end portion Wc when bent back is smaller than the amount of displacement of the end portion Wc when folded. Therefore, by bending the wire W back a small amount after bending it a large amount, fine adjustment can be performed, and the end portion Wc can be positioned more reliably at the second position. In addition, since the elastic limit of the wire W when bent back is smaller than when folded, it is possible to suppress deformation only in the elastic region when bending back a small amount.

[0074] In this manner, in this embodiment, a coil segment 3 having a folded shape with legs 7 provided on the folded portion 5 is obtained.

[0075] As described above, the manufacturing apparatus 1 and method of this embodiment can fold the area between the intermediate portion Wa, which becomes the folded portion 5, and the end portion Wc, which becomes the leg portion 7, by relative displacement of the intermediate portion Wa and the end portion Wc, and then bend the end portion Wc back in the opposite direction to give the desired posture. This makes it possible to obtain a coil segment 3 with a desired folded shape in this embodiment. Therefore, this embodiment makes it possible to set the shape of the coil segment 3 with higher accuracy.

[0076] Furthermore, since the amount of displacement of the end portion Wc when bent back is smaller than the amount of displacement of the end portion Wc when folded, the wire W can be bent a large amount and then bent back a small amount to perform fine adjustments, making it possible to set the shape of the coil segment 3 with greater precision.

[0077] Moreover, since the elastic limit of the wire W is smaller when it is bent back than when it is folded, fine adjustment of the bend of the wire W can be reliably performed even when it is folded back slightly.

[0078] In addition, in this embodiment, the middle portion Wa of the wire W is grasped, and the end side portion Wc located closer to the end portion Wb than the middle portion Wa of the wire W is pressed in a first direction to bend it, and the end side portion Wc is pressed in a second direction to bend it back.

[0079] Therefore, in this embodiment, when setting the folded shape of the coil segment 3, the wire W can be easily bent and unbent. EXAMPLES

[0080] Fig. 8 is a schematic plan view showing a part of a coil segment manufacturing apparatus according to Example 2 of the present invention. Since Example 2 has a basic configuration in common with Example 1, the same reference numerals are given to corresponding configurations and duplicated explanations are omitted. Note that Fig. 8 shows a case where the coil segment is bent as viewed from the direction of Fig. 2.

[0081] As shown in Fig. 8, the manufacturing apparatus 1 of Example 2 bends the intermediate portion Wa of the wire W in the thickness direction of the coil segment 3 to form the apex portion 5a (see Fig. 2) of the crank-shaped folded-back portion 5. Note that in Fig. 8, for ease of understanding, the apex portion 5a is shown as having a simple bent shape.

[0082] The displacement portion 11 of this embodiment bends the wire W between one side portion Wo and the other side portion Wt at the intermediate portion Wa which becomes the folded-back portion 5. The displacement portion 11 has a forming die .

[0083] The forming die 23 presses the middle part Wa of the wire W to bend it between one side part Wo and the other side part Wt of the middle part Wa, and forms a crank shape in the thickness direction of the apex part 5a of the folded part 5. The forming die 23 is composed of a first forming die 23a and a second forming die 23b.

[0084] The first molding die 23a and the second molding die 23b sandwich and bend the middle portion Wa. In this embodiment, the first molding die 23a and the second molding die 23b are a lower die and an upper die for pressing, respectively. The upper surface of the first molding die 23a and the lower surface of the second molding die 23b are processing surfaces for performing press processing, and each corresponds to the crank shape of the folded portion 5 of the coil segment 3 in the thickness direction.

[0085] The unbending unit 13 grips one of the one side portion Wo and the other side portion Wt after pressing, and unbends the other of the one side portion Wo or the other side portion Wt. The unbending unit 13 of this embodiment includes a pressing unit 25 and a cylinder device 27.

[0086] The pressing portion 25 presses the one side portion Wo against the first molding die 23a in a state in which the second molding die 23b is retracted after pressing. This causes the one side portion Wo to be gripped between the pressing portion 25 and the first molding die 23a. The pressing portion 25 can be set to any suitable shape, but in this embodiment, it is formed in a block shape made of resin or the like.

[0087] The cylinder device 27 has the same configuration as the cylinder device 21 of the embodiment 1. However, the cylinder device 27 is disposed so as to be inclined as a whole, facing in a direction intersecting with the other side part Wt.

[0088] FIG. 9 is a schematic front view of the manufacturing apparatus 1, showing a state in which the wire W is placed between the first molding die 23a and the second molding die 23b.

[0089] In the manufacturing method of the coil segment 3 of this embodiment, first, as shown in FIG. 9, the wire W is placed between the first molding die 23a and the second molding die 23b.

[0090] 8, the middle portion Wa of the wire W is sandwiched between the first molding die 23a and the second molding die 23b, and the middle portion Wa is pressed to be formed. That is, the middle portion Wa is bent in a crank shape in the thickness direction between one side portion Wo and the other side portion Wt of the middle portion Wa, following the upper surface 29 of the first molding die 23a and the lower surface 31 of the second molding die 23b.

[0091] As a result, the other side portion Wt of the intermediate portion Wa of the wire W is displaced in the first direction and placed at the first position. In this way, the intermediate portion Wa of the wire W is bent between the one side portion Wo and the other side portion Wt.

[0092] FIG. 10 is a schematic front view of the manufacturing apparatus 1 when bending back the other side portion Wt of the wire rod W in FIG.

[0093] 10, the second molding die 23b is retreated and one side portion Wo of the middle portion Wa is pressed against the first molding die 23a by the pressing portion 25. As a result, the one side portion Wo of the middle portion Wa is gripped between the pressing portion 25 and the first molding die 23a.

[0094] In this state, the movable portion 27a of the cylinder device 27 of the unbending section 13 is advanced. By this advancement, the movable portion 27a of the cylinder device 27 comes into contact with the other side portion Wt of the wire W, and then presses the other side portion Wt.

[0095] As a result, the one side portion Wt of the intermediate portion Wa of the wire W is displaced relative to the one side portion Wo in the second direction, and the one side portion Wo and the other side portion Wt of the intermediate portion Wa of the wire W are bent back to be located at the second position.

[0096] During bending back, similarly to the first embodiment, springback can be suppressed, and the bent back other side portion Wt can be positioned at the second position.

[0097] In this manner, in this embodiment, it is possible to set a highly accurate crank shape in the thickness direction by the intermediate portion Wa of the wire W. Thereafter, the wire W can be bent in the same manner as in the first embodiment to obtain the coil segment 3 having a folded-back shape.

[0098] In the second embodiment, the setting of the crank shape of the intermediate portion Wa of the wire W makes it possible to obtain the same effects as those of the first embodiment. [Explanation of symbols]

[0099] 1 Manufacturing equipment 3 Coil Segment 5 Turning section 7 Legs 9 Gripping part 11 Displacement section 13 Bending section 23 Molding mold W wire rod Wa Middle part Wb end Wc end side part Wo One side Wt other side

Claims

1. A method for manufacturing a coil segment formed by bending a wire, comprising the steps of: displacing one side of the wire relative to the other side in a first direction to bend the wire between the one side and the other side; displacing the other side of the wire relative to the one side in a second direction opposite to the first direction, thereby bending the wire back between the one side and the other side. A method for manufacturing a coil segment.

2. A method for manufacturing the coil segment of claim 1, comprising the steps of: The amount of displacement of the bending back is smaller than the amount of displacement of the bending. A method for manufacturing a coil segment.

3. A method for manufacturing a coil segment according to claim 1 or 2, The coil segment has a pair of legs arranged side by side with a folded portion interposed therebetween, The one side of the wire is one side that becomes one of the folded portion and the leg portion, and the other side of the wire is the other side that becomes the other of the folded portion and the leg portion. A method for manufacturing a coil segment.

4. A method for manufacturing a coil segment according to claim 3, comprising the steps of: Grip the intermediate portion of the wire that will become the folded portion; The bending is performed by pressing an end portion of the wire rod, which is located closer to the end portion than the intermediate portion and which will become the leg portion, in the first direction; The end portion is pressed in the second direction to bend back. A method for manufacturing a coil segment.

5. A method for manufacturing a coil segment according to claim 1 or 2, The coil segment has a pair of legs arranged side by side with a folded portion interposed therebetween, One side of the wire is one side of the portion that will become the folded-back portion, and the other side of the wire is the other side of the portion that will become the folded-back portion. A method for manufacturing a coil segment.

6. A method for manufacturing a coil segment according to claim 5, comprising the steps of: a middle portion of the wire rod that will become the folded portion is pressed to perform the folding between the one side portion and the other side portion of the middle portion; After the pressing, one of the one side portion and the other side portion is gripped to bend back the other of the one side portion or the other side portion. A method for manufacturing a coil segment.

7. A manufacturing apparatus for a coil segment formed by bending a wire, comprising: a displacement unit that displaces one side of the wire relative to the other side in a first direction; a bending-back portion that relatively displaces the other side of the wire rod with respect to the one side in a second direction opposite to the first direction, the displacement portion displaces the other side of the wire in the first direction to bend the wire between the one side and the other side, The unbending portion displaces the other side of the wire in the second direction to unbend the area between the one side and the other side. Coil segment manufacturing equipment.

8. The coil segment manufacturing apparatus according to claim 7, The coil segment has a pair of legs arranged side by side with a folded portion interposed therebetween, The one side of the wire is one side that becomes one of the folded portion and the leg portion, and the other side of the wire is the other side that becomes the other of the folded portion and the leg portion. Coil segment manufacturing equipment.

9. The coil segment manufacturing apparatus according to claim 8, a gripping portion configured to grip an intermediate portion of the wire that becomes the folded portion, the displacement portion presses an end portion of the wire rod, which is located closer to the end portion than the intermediate portion and which becomes the leg portion, in the first direction to perform the bending; The bending-back unit bends back the end portion by pressing the end portion in the second direction. Coil segment manufacturing equipment.

10. The coil segment manufacturing apparatus according to claim 7, The coil segment has a pair of legs arranged side by side with a folded portion interposed therebetween, One side of the wire is one side of the portion that will become the folded-back portion, and the other side of the wire is the other side of the portion that will become the folded-back portion. Coil segment manufacturing equipment.

11. The coil segment manufacturing apparatus according to claim 10, the displacement unit includes a forming die for pressing an intermediate portion of the wire rod that becomes the folded-back portion to perform the folding between the one side portion and the other side portion of the intermediate portion, the bending back unit grips one of the one side portion and the other side portion after the pressing and bends back the other of the one side portion or the other side portion. Coil segment manufacturing equipment.

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