Coil segment forming device and method

Abstract

To provide a coil segment forming device that enables the folded-back shape of a coil segment to be set more easily.SOLUTION: A coil segment forming device includes a first die 9 and a second die 11 for holding a middle portion Wa of a wire W, a tip portion 17 that comes into contact with the middle portion Wa and an end portion Wb of the wire W to become a starting point of bending, a pressing portion 15 supported movably on a moving path 18 facing the outside of the tip portion 17 with a gap therebetween, and a guide for guiding the movement of the pressing portion 15 outside the pressing portion 15 and defining the moving path 18, and the pressing portion 15 presses the end portion Wb of the wire W held by the first die 9 and the second die 11 according to the moving path 18 to perform bending.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an apparatus and method for forming a coil segment having a folded shape formed by bending a wire rod. [Background technology]

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

[0003] As shown in FIG. 7, this forming device holds the middle portion of the wire W with forming dies 105 and 107, and forms a coil segment having a folded-back shape by lowering forming rollers 109 and 111 along a side surface 105a of the forming die 105.

[0004] In this forming, taking into consideration the springback of the coil segment, the folded shape is set so as to gradually approach the end of the wire W. The folded shape 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, depending on the specifications of the coil segments and the characteristics such as the amount of springback of the wire W, there may be cases where it is not necessary to set the folded shape so as to gradually approach the end of the wire W. Even if the folded shape gradually approaches the end of the wire W, the amount of approach at the end may differ depending on the specifications of the coil segments and the characteristics of the wire W. Furthermore, it is necessary to adjust the forming device before mass production so that the desired folded shape can be obtained, taking springback into consideration.

[0006] For this reason, in the conventional forming apparatus, it is necessary to prepare a plurality of forming dies 105 having side surfaces 105a with different inclinations, and it has been desired to be able to set the folded shape of the wire W more easily. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2004-297863 A Summary of the Invention [Problem to be solved by the invention]

[0008] The problem to be solved is that it is desirable to be able to more easily set the folded shape of the coil segments. [Means for solving the problem]

[0009] The present invention provides a coil segment molding device that bends a predetermined length of wire rod to form it into a coil segment with a folded shape, the device comprising: a gripping portion that grips the middle portion of the wire rod; a tip portion that contacts the middle portion of the wire rod and an end portion located closer to the end portion than the middle portion and serves as the starting point of the bending; a pressing portion that is supported on the outside of the tip portion so as to be movable on an opposing movement path with a gap; and a guide that guides the movement of the pressing portion outside the pressing portion and defines the movement path, and the device performs the bending by pressing the end portion of the wire rod gripped by the gripping portion in accordance with the movement path.

[0010] The present invention also provides a method for forming a coil segment by bending a predetermined length of wire to form it into a coil segment with a folded shape, comprising: gripping an intermediate portion of the wire; positioning a tip portion between the intermediate portion of the wire and an end portion located closer to the end than the intermediate portion; guiding a pressing portion moving on an opposing moving path from the outside with a gap to the outside of the tip portion to define the movement; and causing the pressing portion to press the end portion of the wire held by the gripping portion in accordance with the moving path to perform the bending. Effect of the Invention

[0011] The present invention can more easily set the folded shape of the coil segment. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic front view of a coil segment forming device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic front view showing a state in which a wire is placed between a first die and a second die in the molding apparatus of FIG. [Diagram 3] FIG. 3 is a schematic front view showing a state in which a middle portion of a wire is sandwiched between a first die and a second die in the forming apparatus of FIG. [Figure 4] FIG. 4 is a schematic front view of the forming apparatus of FIG. 1 when bending an end portion of the wire. [Diagram 5] FIG. 5 is a schematic front view showing a state in which an end portion of the wire rod has spring back in the forming apparatus of FIG. [Figure 6] FIG. 6 is a conceptual diagram showing a change in the inclination of a guide used in a coil segment forming device according to a second embodiment of the present invention. [Figure 7] FIG. 7 is a schematic diagram of a conventional coil segment forming device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The objective of making it easier to set the folded shape of the coil segments is achieved by providing a guide for the pressing part on the outside of the pressing part that presses the wire.

[0014] That is, the coil segment forming device 1 bends a wire W of a predetermined length to form a coil segment 3 having a folded-back shape. The forming device 1 includes gripping portions 9 and 11, a tip portion 17, a pressing portion 15, and a guide 13.

[0015] The gripping parts 9 and 11 grip the middle part Wa of the wire W. The tip 17 contacts the middle part Wa of the wire W and the end part Wb located closer to the end part Wc than the middle part Wa, and serves as the starting point for bending. The pressing part 15 is supported movably on a moving path 18 that faces the outside of the tip 17 with a gap therebetween. The guide 13 guides the movement of the pressing part 15 from the outside of the pressing part 15, and defines the moving path 18. The pressing part 15 presses the end part Wb of the wire W gripped by the gripping parts 9 and 11 according to the moving path 18 to perform bending.

[0016] The guide 13 may guide the movement of the pressing part 15 by a linear incline. It is preferable that the guide 13 is provided so that its posture can be changed, and the direction of the movement path 18 can be changed according to the posture. When the guide 13 has a linear incline, the incline of the guide 13 may be changeable.

[0017] The molding device 1 may also be provided with an avoidance space 20 into which the end portion Wb is inserted during bending to avoid the end portion Wb being subjected to pressure.

[0018] The gripping portions 9 and 11 include a first die 9 and a second die 11 that sandwich the middle portion Wa of the wire W, and the tip portion 17 may be provided on the first die 9 .

[0019] The pressing portion 15 may bend the end Wc of the wire W so that the end Wc gradually approaches each other.

[0020] The method of forming the coil segment involves gripping the middle portion Wa of the wire W, positioning the tip 17 between the middle portion Wa and the end portion Wb of the wire W, leaving a gap on the outside of the tip 17 and guiding the pressing portion 15 moving on the opposing moving path 18 from the outside to define the moving path 18, and the pressing portion 15 pressing the end portion Wb of the wire W gripped by the gripping portions 9 and 11 in accordance with the moving path 18 to perform bending. EXAMPLES

[0021] [Coil segment forming equipment] FIG. 1 is a schematic front view of a coil segment forming device according to a first embodiment.

[0022] As shown in FIG. 1, a coil segment forming device 1 bends a wire W of a predetermined length to form a coil segment 3 in a folded-back shape.

[0023] The coil segment 3 is used in a stator coil as a coil segment of a rotating electric machine. Note that the coil segment 3 in Fig. 1 shows a state before springback after bending and forming a wire material W. Strictly speaking, this coil segment 3 is not a completed coil segment 3, but for convenience of explanation, the wire material W and the coil segment 3 are simultaneously indicated, and the coil segment 3 is enclosed in parentheses.

[0024] The coil segment 3 in Fig. 1 has a molded middle portion 5 and legs 7 on both sides that are bent at shoulder portions 3b relative to the middle portion 5. The legs 7 are inserted into slots in a stator of a rotating electric machine (not shown). The entire coil segment 3 is covered with insulating resin, and the resin is removed at the tips 7a of the legs 7.

[0025] The molding device 1 includes a first die 9 and a second die 11 serving as gripping parts for molding the coil segment 3, a guide 13, and a pressing part 15.

[0026] The first die 9 and the second die 11 sandwich the middle part Wa and bend it, and form the top part of the folded shape by pressing. Although there is a gap between the wire W and the first die 9 and the second die 11 in Fig. 1, in reality, the wire W is in close contact with the first die 9 and the second die 11 without any gap.

[0027] In this embodiment, the first die 9 is a lower die, and the second die 11 is an upper die. However, the first die 9 and the second die 11 may only grip the middle part Wa of the wire W without processing it. In this case, the gripping parts are not limited to the first die 9 and the second die 11 as long as they can grip the middle part Wa.

[0028] In addition, up and down means up and down in the pressing direction of the first die 9 and the second die 11, and left and right means up and down in the pressing direction, as viewed from the front of the molding apparatus 1 in FIG.

[0029] The first die 9 in this embodiment has a tip 17. The tip 17 may be provided separately from the first die 9. The middle part Wa of the wire W corresponds to the middle part 5 of the molded coil segment 3, and refers to the part sandwiched between the first and second dies 9 and 11. The end part Wb of the wire W corresponds to the molded leg part 7, and refers to the part protruding from the first and second dies 9 and 11 and located closer to the end part Wc than the middle part Wb. The end part Wc of the wire W corresponds to the tip 7a of the leg part 7.

[0030] The upper surface of the first die 9 is a convex surface, and is formed by a central surface 19 and left and right side surfaces 21 and 23. The left and right side surfaces 21 and 23 are inclined surfaces that gradually reduce the left and right width of the first die 9 toward the central surface 19. The central surface 19 is a flat surface extending along the left and right. The central surface 19 can be shaped appropriately depending on the shape of the intermediate portion 5 of the coil segment 3, and can be, for example, an upwardly convex curved surface. If the central surface 19 is a convex curved surface, it may be smoothly continuous with the left and right side surfaces 21 and 23.

[0031] The bottom surface of the first die 9 is formed symmetrically with the top surface, and is formed by a central surface 25 and left and right side surfaces 27 and 29. The central surface 25 is a flat surface extending along the left and right, and the side surfaces 27 and 29 are inclined surfaces that gradually reduce the left and right width of the first die 9 toward the central surface 25. In this embodiment, these side surfaces 27 and 29 are retracted from the moving path 18 by setting an inclination, and are configured not to interfere with the end portion Wb during bending.

[0032] In this embodiment, an avoidance space 20 is provided by retracting the side surfaces 27 and 29 from the moving path 18 and setting the vertical dimensions of the first die 9. The avoidance space 20 is a space below the first die 9, into which the end portion Wb is inserted during folding to prevent the end portion Wb from being subjected to pressure. In other words, even if the end portion Wb is pressed during folding, it is not received by the side surfaces 27 and 29. The avoidance space 20 can also be set by providing recesses in the side surfaces 27 and 29 of the first die 9.

[0033] The bottom surface of the second die 11 is a concave surface corresponding to the top surface of the first die 9, and is formed by a central surface 31 and left and right side surfaces 33 and 35. The central surface 31 is a flat surface extending along the left and right, and the side surfaces 33 and 35 are inclined surfaces that gradually reduce the left and right width of the second die 9 toward the central surface 31. The central surface 31 can be shaped appropriately depending on the shape of the intermediate portion 5 of the coil segment 3, and can be, for example, an upwardly concave curved surface. If the central surface 31 is a concave curved surface, it may be smoothly continuous with the left and right side surfaces 33 and 35.

[0034] The tip 17 contacts between the middle part Wa of the wire W having a predetermined length and the end part Wb located on the end part Wc side of the middle part Wa, and serves as a starting point for bending. The tip 17 in this embodiment is provided in the first die 9. That is, the tip 17 is formed between the side surfaces 21 and 23 and the side surfaces 27 and 29 of the first die 9, respectively, and protrudes on both the left and right sides. The tip 17 has a pointed shape, but it can also be formed into other shapes, such as an arc shape or a rectangle. The tip 17 may be provided separately from the first die 9, as long as it is provided at a position where it contacts the wire W as a starting point for bending.

[0035] The pressing part 15 is supported movably on a moving path 18 that faces the outer side of the tip 17 with a gap therebetween. The moving path 18 is a linear inclined path that gradually leans downward toward the first die 9. The pressing part 15 is provided with a roller 45 at the lower end of each support rod 43.

[0036] The support rod 43 is connected to a drive mechanism such as an actuator (not shown), and is raised and lowered in an inclined direction along the moving path 18 .

[0037] The rollers 45 come into contact with the end portion Wb of the wire W whose middle portion Wa is being gripped and press it downward while moving along the moving path 18. In this embodiment, the rollers 45 press the end portion Wb downward and toward the left and right side surfaces 27 and 29 according to the moving path 18. This causes the wire W to be bent so that the end portion Wb gradually approaches the end Wc.

[0038] The end portion Wb does not need to be bent so as to gradually approach the end portion Wc. In other words, depending on the specifications of the coil segment 7 and the characteristics of the wire W such as the amount of springback, the end portion Wb may be bent so as to be substantially parallel, or so as to gradually separate from the end portion Wc.

[0039] Furthermore, the pressing portion that presses the end portion Wb does not need to be a roller 45, and may be a non-rotating roller-shaped portion, a block-shaped portion, or the like. The arrangement and number of the rollers 45 are free, and the end portion Wb can be pressed by a plurality of rollers 45 on one side. Alternatively, the rollers 45 can be arranged only on either the left or right side, and the end portion Wb can be folded on one side at a time.

[0040] The guide 13 is disposed on the outside of the first die 9. The guide 13 is a roller guide that guides the roller 45. However, the guide 13 is not limited to a roller guide as long as it can guide the pressing portion 15.

[0041] The guide 13 guides the movement of the pressing portion 15 from outside the pressing portion 15, and defines a movement path 18. The guide 13 of this embodiment includes a pair of guide plates 37 on the outside of the first die 9.

[0042] The upper end of each guide plate 37 is located below the tip 17. The guide plate 37 is a linearly inclined plate that gradually leans left and right toward the first die 9 as it goes downward. Therefore, the guide 13 guides the movement of the pressing part 15 by the linear inclination of the guide plate 37. The guide 13 may be formed in an arc or bent shape to guide the pressing part 15. Also, the guide 13 is not limited to a plate as long as it can form a guide surface that guides the roller 45.

[0043] The degree of inclination of the guide plate 37 is set to be smaller than the degree of inclination of the left and right side surfaces 27 and 29. Therefore, the guide plate 37 is set so as to be gradually spaced apart from the left and right side surfaces 27 and 29 in the downward direction.

[0044] The guide plate 37 is supported by a guide base 39. The guide base 39 is integrally joined by a connecting bar 41.

[0045] [Coil segment forming method] FIG. 2 is a schematic front view of the forming device 1 showing a state in which the wire W is placed between the first die 9 and the second die 11. As shown in FIG.

[0046] In the molding method of the coil segment 3 of this embodiment, first, a wire W is placed between a first die 9 and a second die 11 as shown in Fig. 2. The wire W is a V-shaped wire that is made by cutting a flat wire with a rectangular cross section to a predetermined length and then bending the middle part Wa in a direction perpendicular to the paper surface of Fig. 2 as shown in Fig. 7. The end part Wc of the cut wire W has had the resin removed. The wire W placed between the first die 9 and the second die 11 may be straight without bending the middle part Wa.

[0047] Fig. 3 is a schematic front view of the forming device 1 showing a state where the intermediate portion Wa of the wire W in Fig. 2 is sandwiched between the first die 9 and the second die 11 and formed. In Fig. 3, the wire W and the guide 13 overlap, but the guide 13 is positioned shifted from the wire W in the direction perpendicular to the paper surface. Accordingly, the roller 45 of the pressing part 15 is formed long in the direction perpendicular to the paper surface of Fig. 3 so as to be able to contact both the guide 13 and the wire W. This is the same in Figs. 1 and 2 and Figs. 4 and 5.

[0048] 3, the intermediate portion Wa of the wire W is sandwiched between the first die 9 and the second die 11, and the intermediate portion Wa is formed. Through this forming, the intermediate portion Wa is bent along the central surface 19 and the left and right side surfaces 21 and 23 of the first die 9 and the central surface 31 and the left and right side surfaces 33 and 35 of the second die.

[0049] FIG. 4 is a schematic front view of the forming device 1 when bending the end portion Wb of the wire W in FIG.

[0050] 4, the pressing part 15 descends while keeping the middle part Wa of the wire W sandwiched between the first die 9 and the second die 11, i.e., while gripping the middle part Wa. By this descent, the pressing part 15 contacts the end part Wb of the wire W gripped between the first die 9 and the second die 11 according to the moving path 18, and then presses the end part Wb downward.

[0051] In this embodiment, the roller 45 of the pressing unit 15 descends while being guided by the guide plate 37, and contacts and presses the end portion Wb. As a result, the wire W is pressed against the tip 17 between the end portion Wb and the middle portion Wa, and bending proceeds with the tip 17 as the starting point. At this time, the roller 45 receives a reaction force from the guide plate 37, and can reliably bend the wire W.

[0052] Then, when the roller 45 passes over the tip 17, the bending of the wire W is completed. The folded shape of the wire W after the bending is set according to the movement path 18 of the pressing part 15 (roller 45), particularly the amount of movement in the left-right direction, and in this embodiment, the end side portion Wb gradually approaches the end Wc.

[0053] When this folded shape is set, the guide 13 is set so as to gradually move away from the left and right side surfaces 27 and 29 of the lower surface of the first die 9 in the downward direction, thereby setting an avoidance space 20, so that the end side portion Wb of the wire W is not pressed against the left and right side surfaces 27 and 29. This makes it possible to suppress deformation and damage to the wire W, even when the folded shape of the wire W is set so that the end side portion Wb gradually approaches the end Wc.

[0054] FIG. 5 is a schematic front view of the forming apparatus 1, showing a state in which the end portion Wb of the wire W in FIG. 4 has spring back.

[0055] As shown in Fig. 5, after bending is completed, the pressing part 15 rises. When the pressing part 15 rises, the pressing force on the end part Wb is released, and the end part Wb becomes almost parallel due to springback to become the leg part 7. Note that the leg part 7 after springback may be inclined so as to gradually approach or move away from the end part Wc, as described above. This shape after springback is realized by setting the inclination of the guide 13 (the movement path 18 of the pressing part 15) according to the amount of springback.

[0056] In this manner, in this embodiment, a coil segment 3 having a folded-back shape and legs 7 extending from the intermediate portion 5 via shoulders 3b is obtained.

[0057] As described above, the molding device 1 of this embodiment is equipped with a tip 17 that comes into contact between the middle portion Wa and the end portion Wb of the wire W and serves as the starting point of bending, a pressing section 15 that is supported so as to be movable on a moving path 18 that faces the outside of the tip 17 with a gap therebetween, and a guide 13 that guides the movement of the pressing section 15 outside the pressing section 15 and defines the moving path 18, and can bend the wire W into a folded shape according to the moving path 18 based on the guide 13.

[0058] Therefore, the folded shape of the coil segment 3 can be easily set by the guide 13. Even if multiple guides 13 are prepared, the folded shape of the coil segment 3 can be set extremely easily and inexpensively compared to the conventional case in which multiple dies are prepared. As a result, this also leads to a reduction in the production cost of the coil segment 3.

[0059] Furthermore, since guide 13 guides the movement of pressing portion 15 by a linear incline, movement path 18 of pressing portion 15 is simplified, and the folded-back shape of coil segment 3 can be set more easily.

[0060] In addition, the molding apparatus 1 of this embodiment is provided with an avoidance space 20 in which the end side portion Wb is inserted during bending to avoid the end side portion Wb being subjected to pressure, so that the end side portion Wb of the wire W is not pressed against the left and right side surfaces 27 and 29, thereby suppressing deformation and damage to the wire W.

[0061] In this embodiment, the first die 9 and the second die 11 are provided as gripping parts for clamping the middle part Wa of the wire W, and the tip part 17 is provided on the first die 9, so that the structure of the forming device 1 can be simplified. Therefore, it is possible to set the folded shape of the coil segment 3 more easily. EXAMPLES

[0062] 6 is a conceptual diagram showing a change in the inclination of a guide 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.

[0063] As shown in Fig. 6, the guide 13 of the second embodiment is configured so that the inclination of the guide plate 37 with respect to the guide base 39 can be changed. As a result, the guide 13 is configured so that the posture can be changed, and the direction of the moving path 18 can be changed depending on the posture. The rest is the same as the first embodiment.

[0064] The guide plate 37 is supported so as to be able to swing freely relative to the guide base 39, and is fixed by a jig or the like. For example, the guide plate 37 is fixed by butting rods against the upper and lower parts of its back surface, and swings as the upper and lower rods move forward and backward, changing the inclination as the attitude of the guide 13.

[0065] The jig may be operated by an actuator. Also, the guide plate 37 may be supported by an actuator such as an electric motor and directly tilted by the actuator. Also, the guide 13 may be replaceable. That is, a plurality of guides 13 with different inclinations of the guide plate 37 are prepared, and these are attached to the connecting bar 41 as appropriate in a replaceable manner.

[0066] In the left side of Fig. 6, the inclination of the guide plate 37 is the same as in Example 1, and both legs 7 are made substantially parallel by springback after bending of the end portion Wb of the wire W. In the upper right part of Fig. 6, the inclination angle of the guide plate 37 is made smaller, and the bending of the end portion Wb of the wire W is made relatively weak. In the lower right part of Fig. 6, the inclination angle of the guide plate 37 is made larger, and the bending of the end portion Wb of the wire W is made relatively strong.

[0067] In this way, by changing the inclination of the guide plate 37, which is the attitude of the guide 13, the bending of the end side portion Wb of the wire W can be easily adjusted, and the man-hours and costs for the adjustment can be reduced. By such an adjustment, the folded shape of the coil segment 3 can be set more easily.

[0068] For example, even when using a wire W having a smaller or larger amount of springback, the folded shape of the coil segment 3 can be easily set so that the legs 7 are substantially parallel by changing the position of the guide 13. Alternatively, between wires W having the same amount of springback, different folded shapes of the coil segment 3 can be easily set by changing the position of the guide 13 so that the legs 7 gradually approach or move away from each other toward the tips 7a.

[0069] Furthermore, in adjusting the forming device 1 before mass production, the posture of the guide 13 can be changed to easily obtain the desired folded shape of the coil segment 3, and then mass production can be performed. This leads to a reduction in the production cost of the coil segment 3.

[0070] In addition, in this embodiment, the same effects as those in the first embodiment can be obtained. [Explanation of symbols]

[0071] 1 Molding equipment 3 Coil Segment 9 Type 1 (grip part) 11 Type 2 (grip part) 13 Guide 15 Pressing section 17 Tip W wire rod Wa Middle part Wb end side part Wc end

Claims

1. A coil segment forming device that bends a wire rod of a predetermined length to form a coil segment having a folded shape, A gripping portion that grips a middle portion of the wire; a tip portion that contacts the intermediate portion of the wire rod and an end portion located on the end side of the intermediate portion and serves as a starting point of the bending; A pressing part supported movably on a moving path facing the outer side of the tip part with a gap therebetween; A guide that guides the movement of the pressing part on the outside of the pressing part and defines the movement path; Equipped with the pressing portion presses the end portion of the wire held by the holding portion according to the movement path to perform the bending. Coil segment forming equipment.

2. The coil segment forming apparatus according to claim 1, The guide guides the movement of the pressing portion by a linear inclination. Coil segment forming equipment.

3. The coil segment forming apparatus according to claim 1, The guide is provided so as to be able to change its posture, and the direction of the moving path is able to be changed depending on the posture. Coil segment forming equipment.

4. The coil segment forming apparatus according to claim 1, and an avoidance space into which the end portion is inserted when the end portion is bent to avoid the end portion being subjected to the pressing force. Coil segment forming equipment.

5. The coil segment forming apparatus according to any one of claims 1 to 4, the gripping portion includes a first die and a second die that sandwich the intermediate portion of the wire, The tip is provided on the first mold, Coil segment forming equipment.

6. The coil segment forming apparatus according to any one of claims 1 to 4, The pressing portion performs the bending so that the ends of the wire become gradually closer to each other. Coil segment forming equipment.

7. A coil segment forming method for forming a coil segment into a folded-back shape by bending a wire rod of a predetermined length, comprising the steps of: Grip the middle portion of the wire, a tip portion is positioned between the intermediate portion of the wire rod and an end portion located closer to the end portion than the intermediate portion; A pressing part that moves on a moving path facing the outer side of the tip part is guided from the outside to define the movement, the pressing portion presses the end portion of the wire gripped by the gripping portion according to the movement path to perform the bending. A method for forming coil segments.

8. The coil segment forming method according to claim 7, The bending is performed so that the ends of the wire gradually approach each other. A method for forming coil segments.

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