Coil manufacturing method

Abstract

To provide a coil manufacturing method that can improve the space factor in a core and improve heat dissipation, and can mass-produce high-quality coils that do not suffer from characteristic deterioration due to cutting and joining.SOLUTION: A coil manufacturing method includes a step of preparing a helical structure, an annealing step for the helical structure, an insulating step of a spiral structure, and a molding step of making the spiral structure into a desired shape.SELECTED DRAWING: Figure 14

Description

Technical Field

[0001] The present invention is relates to a method for manufacturing a coil.

Background Art

[0002] In a stator, which is a component of a motor, coils are arranged around a core (stator core). In order to reduce the loss and size of the motor, it is important to improve the occupancy ratio of the coils in the core.

[0003] As a coil capable of improving the occupancy ratio in the core, for example, a coil is known in which end faces of flat conductors punched out in a U-shape (U-shaped) are joined by cold pressure welding to form a region for one turn of the coil, and this is continuously formed in a spiral shape, and a manufacturing apparatus therefor (see, for example, Patent Document 1).

[0004] According to the technique described in Patent Document 1, it is possible to provide a high-quality coil that can improve the occupancy ratio in the core and heat dissipation, and does not cause deterioration of characteristics due to cutting and joining.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, Conventionally it cannot be said that sufficient consideration has been given to the technology for mass-producing high-quality coils, and there is room for improvement from the viewpoint of improving productivity.

[0007] The present invention 、 is capable of mass-producing high-quality coils coil manufacturing method and aims to provide the same.

Means for Solving the Problems

[0008] The present invention solves the above problems by the following means.

[0009] The present invention continuously stacks a plurality of regions corresponding to one turn around the axis (hereinafter referred to as "one-turn region") such that a gap is generated between the regions for one turn in the extending direction of the axis was spiral structure forming step, and after annealing the spiral structure in a state where the gap is generated a step of annealing the spiral structure; after annealing the spiral structure a step of insulating each of the one-turn regions; a step of insulating each of the regions for one turn and then compressing the spiral structure along the extending direction of the shaft and has a coil manufacturing method characterized by this.

Effects of the Invention

[0012] According to the present invention 、 mass production of high-quality coils possible coil manufacturing method can be provided.

Brief Description of the Drawings

[0013]

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Mode for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0015] <Coil Manufacturing Apparatus> FIG. 1 is an external view schematically showing the configuration of the coil manufacturing apparatus 10 according to this embodiment.

[0016] The coil manufacturing apparatus 10 of the present embodiment forms a coil, which is a spiral structure, by joining a plurality of flat conductors C. The coil manufacturing apparatus 10 includes a bending means (bending device) 30 that bends each of the plurality of flat conductors C to form a bent portion B0, a joining means (joining device) 20 that joins the plurality of flat conductors C, and a removing means (removing device) 40 that removes a part of the joined flat conductor C.

[0017] The bending device 30 is provided upstream of the joining device 20 and bends each flat conductor C so that a part along the spiral traveling direction inclines with respect to the other part before being supplied to the joining device 20, thereby forming the bent portion B0.

[0018] The joining device 20 is provided downstream of the bending device 30. The joining device 20 presses the end faces of the flat conductor C and another flat conductor C along the strip longitudinal direction, and cold-welds them while shortening the distance in the strip longitudinal direction to form a joined body (joined coil piece) CC of the flat conductors, and joins these to form a spiral structure.

[0019] The removing device 40 is provided downstream of the joining device 20 and is a means for removing burrs generated by the cold welding of the flat conductor C and another flat conductor C.

[0020] These will be described in detail below.

[0021] <Flat Conductor> First, the flat conductor C used in the coil manufacturing apparatus 10 of the present embodiment will be described. FIG. 2 is a diagram showing an example of the flat conductor C used in the coil manufacturing apparatus 10 of the present embodiment. FIG. 2(A) is a top view of the completed coil 50 seen from the axial direction of the spiral structure, FIG. 2(B) is a top view of the flat conductor C, and FIG. 2(C) is an enlarged view of the cross section taken along the line X-X in FIG. 2(B). FIGS. 2(D) to 2(G) are top views showing an example of the shape of the flat conductor C.

[0022] As shown in FIG. (A), the coil 50 of the present embodiment is configured by continuously joining a plurality of flat conductors C to form a spiral structure, and the region for one turn of the spiral structure (hereinafter referred to as the one-turn region CR) is (substantially) rectangular. Further, the flat conductor C constituting the coil 50 is also referred to as a coil piece C in the following description.

[0023] The flat conductor (coil piece) C of the present embodiment is a strip-shaped (tape-shaped) conductor configured in a plane as shown in FIGS. (B) and (C) with respect to a round wire conductor having a substantially circular cross-section perpendicular to the axial direction. That is, the coil piece C has two opposing wide surfaces WS and two opposing narrow surfaces WT, and is a strip-shaped member that is long in a predetermined direction, and the cross-section (X-X line cross-section in FIG. (B)) perpendicular to the strip longitudinal direction BL is a rectangular or rounded rectangular conductor as shown in FIG. (C). In the following description, as an example of the flat conductor, a flat conductor having a (substantially) rectangular cross-section perpendicular to the strip longitudinal direction as shown in the upper figure of FIG. (C) will be described as an example.

[0024] Specifically, each of the flat conductors (coil pieces) C has a length equal to or less than the length of the one-turn region CR of the spiral structure, and has a linear shape (FIG. (B)) or a shape having at least one direction conversion portion TN (FIGS. (D) to (G)). Here, the direction conversion portion TN is a portion bent so as to change the extending direction in the strip longitudinal direction.

[0025] In the case of the flat conductor (coil piece) C having the direction conversion portion TN as shown in FIGS. (D) to (G), it is assumed that it is bent in the same direction (always to the right or left) along the strip longitudinal direction so as to form a spiral shape when continuous. Further, in the case of the coil piece C having the direction conversion portion TN, it is desirable that at least one (preferably all) of the direction conversion portions TN has a non-curved (for example, substantially right-angled) shape.

[0026] In the following description, a spiral structure is formed by continuously connecting (connecting) a plurality of coil pieces (flat conductors) C, and the spiral structure before being completed as a coil (completed spiral structure) 50 is also included in the coil piece C. That is, in the following description, the coil piece C includes a linearly shaped or a minimum unit coil piece (coil piece before connection) having a direction conversion portion TN in the same direction in the belt longitudinal direction, and a coil piece formed by connecting a plurality of the minimum unit coil pieces and having a spiral structure longer than one turn region CR of the coil (spiral structure to be completed). For the sake of convenience in description, when such a distinction is necessary, the minimum unit coil piece is referred to as a unit coil piece C0 (C01, C02, C03... C0N), and a joined body of coil pieces before becoming a coil (spiral structure to be completed) 50, which is formed by connecting a plurality of unit coil pieces C0, is referred to as a joined coil piece CC (CC1, CC2... CCN), and the spiral structure to be completed (completed state) is referred to as a coil 50.

[0027] As an example, the coil piece C (unit coil piece C0) is formed into a shape having a linear or substantially right-angled (non-curved) direction conversion portion (corner portion) TN by punching a copper plate (for example, a plate-shaped oxygen-free copper with a thickness of 0.1 mm to 5 mm, etc., high-purity copper of 99.95% or more without oxides). That is, in a top view of the wide surface WS, the unit coil piece C0 has a linear shape (I-shaped) (Fig. (B) thereof) without a direction conversion portion TN, an L-shaped one (Fig. (D) thereof) having one direction conversion portion TN, a U-shaped (C-shaped) one (Fig. (E) thereof) having two direction conversion portions TN, a substantially C-shaped one (Fig. (F) thereof) having three direction conversion portions TN, and a C-shaped one (Fig. (G) thereof) having four direction conversion portions TN. In the following description, it is referred to as U-shaped, (substantially) C-shaped, or substantially O-shaped, but all direction conversion portions TN (corners) are assumed to have a substantially right-angled shape.

[0028] A plurality of coil pieces C (unit coil pieces C0 and / or joined coil pieces CC) are set such that a preparation length L0, which is the total distance in the longitudinal direction of their bands, is longer by a margin compared to the completed length in the longitudinal direction of the spiral structure (coil) 50 that is planned to be completed. The margin is set to the total shortening distance that is shortened by pressing when all of the plurality of coil pieces C are cold pressure-welded. The preparation length L0, the completed length, the margin, and the total shortening distance will be described in detail in the description of the coil manufacturing method below.

[0029] In the following example, the case of manufacturing the coil 50 using the U-shaped (horseshoe-shaped) flat conductor (coil piece) C shown in Fig. 2(E) will be described. However, the coil piece C may be any of those shown in Fig. 2, or any combination of the plurality of shapes shown in Fig. 2.

[0030] <Bending device> The bending device 30 of the present embodiment will be described with reference to Figs. 3 to 6. Fig. 3 is a schematic diagram of the bending device 30 of the present embodiment. In the figure, (A) is a top view showing the coil piece C before deformation supplied to the bending device 30, and (B) is a schematic diagram of the bending device 30. In the upper part of Fig. 3(B), a top view and a side view of the coil piece C before deformation are shown side by side, and in the lower part, a top view and a side view of the coil piece C after deformation by the bending device 30 shown in the middle part are shown vertically side by side. Fig. 4 is a top view showing the outline of the bending device 30. Figs. 5 and 6 are front views showing the schematic configuration and the bending state of a part (deformation part 37) of the bending device 30.

[0031] Note that, although it will be described in detail later in the description of the <coil manufacturing method>, actually, the coil pieces C1 and C2 are pressure-welded by the joining device 20 and the distance between them is shortened. However, for the sake of convenience in mainly describing the deformation by the bending device 30 here, the shortening of the distance due to pressure welding (the displacement of the length of the long side LS between the state of just abutting and the state after pressure welding) will not be mentioned. Also, hereinafter, the displacement of the length due to pressure welding will be omitted in the description of the coil manufacturing device 10 with reference to Figs. 3 to 14.

[0032] First, referring to FIG. 3(A), in this embodiment, as an example, one end face TS1, TS2 of each of two coil pieces C (C1, C2) having substantially the same U-shaped form shown in FIG. 3(A) are butted against each other to form a joint portion CP, and a one-turn region CR having a (substantially) rectangular shape with a long side LS and a short side SS is configured. Here, for convenience, they are denoted as coil pieces C1 and C2, but both are coil pieces C of substantially the same shape that are turned inside out with the end faces TS1 and TS2 as the centers.

[0033] Also, in order to form a predetermined number of continuous one-turn regions CR, the other end faces TS0, TS1' of the coil 50 are not joined, and the one-turn region CR in this state is discontinuous, for example, at the opposing position of the joint portion CP. For example, when the coil pieces C1 and C2 shown in FIG. 3(A) are the first two pieces, the end face TS0 of the coil piece C1 is led out to the outside by being connected to, for example, another coil piece (not shown) that constitutes a terminal, and the end face TS1' of the coil piece C2 is joined to the end face of the next coil piece (not shown).

[0034] That is, in this case, one long side LS of the one-turn region CR (the upper side in FIG. 3(A)) is composed of the long side region LS1 (LS11) of the coil piece C1 and the long side region LS1 (LS12) of the coil piece C2, while the other long side LS of the one-turn region CR (the lower side in FIG. 3(A)) is composed of the long side region LS2 (LS22) of the coil piece C2 and the long side region of another (next) coil piece of the same shape (not shown).

[0035] As shown in FIG. 3(B), the bending device 30 of this embodiment is a device that bends a part of the coil piece C before deformation (the upper part in FIG. 3(B)) to be supplied as shown in the lower part in FIG. 3(B) to form a bent portion B0. Here, the coil piece C before deformation refers to a flat coil piece C that has been punched out from a flat plate and exists in a substantially the same plane without being intentionally deformed in the entire region of the coil piece C.

[0036] Specifically, as shown in FIG. 4, the bending device 30 has, for example, a supply unit 31 for the coil piece C, a transport unit 33, a support unit 35, and a deformation unit 37. The supply unit 31 is provided with, for example, a turntable 311 capable of stocking a plurality (for example, four sheets) of coil pieces C before deformation, and the coil pieces C before deformation are supplied from the upstream process.

[0037] The coil pieces C before deformation on the turntable 311 are supplied one by one to the support unit 35 as the turntable 311 rotates.

[0038] The support unit 35 has a support table 351 on whose surface (upper surface) the coil piece C can be placed, and a pressing unit 353 that presses a part of the coil piece C placed on the support table 351 from above. The coil piece C before deformation is placed on the support table 351, and a part of it is sandwiched between the support table 351 and the pressing unit 353 and temporarily fixed.

[0039] Specifically, the support unit 35 holds the coil piece C such that, for example, a part of the coil piece C protrudes from the support table 351 (in a state where the support table 351 does not exist directly below a part of the coil piece C).

[0040] For example, in the case of a U-shaped coil piece C, only one long side region LS2 is sandwiched between the support table 351 and the pressing unit 353, and the short side SS is held so as to protrude horizontally from the support table 351 (in a state where the support table 351 does not exist directly below it). Note that the other long side region LS1 may be placed on the support table 351, but is not pressed by the pressing unit 353 (not sandwiched between the support table 351) and a change in posture is allowed.

[0041] The transport unit 33 has, for example, a rail member 331 and a drive unit 333 that moves the support unit 35 along the rail member 331, for example, in the horizontal direction. Further, the transport unit 33 temporarily stops the support unit 35 at a predetermined pressing position within the deformation unit 37.

[0042] The deformable portion 37 is configured to be movable so as to approach and separate from the support portion 35 (in this example, it is movable up and down).

[0043] The deformable portion 37 will be described with reference to FIGS. 5 and 6. Both figures are diagrams showing the deformable portion 37 and the bending process of the coil piece C by it in time series. FIGS. 5(A) to 5(C) are front views (views seen from the lower side of FIG. 4), and FIG. 5(D) is a diagram showing the deformed coil piece C shown in FIGS. 5(B) and 5(C), where the upper figure is a top view and the lower figure is a side view (for the deformable portion 37, it is a front view).

[0044] Also, FIGS. 6(A) to 6(C) are front views (views seen from the lower side of FIG. 4), and FIG. 6(D) is a diagram showing the deformed coil piece C shown in FIGS. 6(B) and 6(C), where the upper figure is a top view and the lower figure is a side view (for the deformable portion 37, it is a front view).

[0045] Referring to FIG. 5, the deformable portion 37 has a clamping portion 371 and a biasing portion 373. The deformable portion 37 (the clamping portion 371 and the biasing portion 373) is configured to be movable up and down so as to approach and separate from the support portion 35 in this example. The biasing portion 373 has an inclined surface 373S that is inclined with respect to the surface of the support table 351 (FIG. 5(A)).

[0046] When the clamping portion 371 descends, it abuts on a part of the upper surface of the coil piece C held by the support portion 35 and clamps the coil piece C between the support table 351. Also, the biasing portion 373 is located, for example, laterally of the clamping portion 371. When it descends, its inclined surface 373S abuts on a part (for example, the short side SS) of the coil piece C that protrudes horizontally from the support table 351, and in this example, it is bent downward to form a bent portion B0 (FIG. 5(B)). In this example, the surface of the coil piece C on the side that abuts on the deformable portion 37 (the clamping portion 371 and the biasing portion 373) is mountain-folded at the bent portion B0.

[0047] Note that the clamping part 371 and the biasing part 373 may perform lifting operations at the same timing or at different timings. When they perform lifting operations at different timings, at least during descent, first the clamping part 371 descends to hold down the coil piece C, and then the biasing part 373 descends to bend the coil piece C.

[0048] At this time, the support part 35 (pressing part 353) presses only one long side region LS2 of the coil piece C, and the other long side region LS1 of the coil piece C is not pressed by the pressing part 353 (see FIG. 4). Therefore, when the short side SS is bent downward by the biasing part 373, the long side region LS1 that is continuous with this changes its posture so as to be inclined with respect to the other long side region LS2 (FIG. 5(B)).

[0049] After deformation, as shown in FIG. (C) of the same figure, the clamping part 371 and the biasing part 373 rise, and the deformed coil piece C is discharged from the deforming part 37 by the conveying part 33 (FIG. 4).

[0050] Due to this deformation, specifically, as shown in FIG. (D) of the same figure, one long side region LS1 and the short side SS of the coil piece C are located in substantially the same plane (hereinafter referred to as the reference plane SF0). When the reference plane SF0 is held horizontally, the other long side region LS2 is bent so as to be inclined with respect to the reference plane SF0 with the bent part B0 as a boundary. More specifically, the other long side region LS2 is such that the end T2 on the side away from the short side SS (the side farther from the short side SS) is located below (or above) the reference plane SF0 than the end T1 on the short side SS side. In other words, the bending device 30 bends the coil piece C from the position of the bent part B0 (shown by the broken line in the upper figure of FIG. (D) of the same figure) so that the angle formed by the reference plane SF0 (one long side region LS1) and the other long side region LS2 becomes the angle α.

[0051] In this way, the bending device 30 of the present embodiment bends one of the two opposing sides (long side regions LS1, LS2) on the long side of the coil piece C that is planned to form the one-round region CR of the coil 50 so as to be inclined with respect to the other.

[0052] Note that the one long-side region LS1 and the other long-side region LS2 in the above example only have different names for convenience of explanation. That is, the same applies even if the long-side regions LS1 and LS2 are interchanged. In the deformed portion 37, it may be deformed such that the angle formed by the one long-side region LS1 and the other long-side region LS2 becomes a predetermined angle α.

[0053] FIG. 6 is a diagram showing another example of the deformed portion 37. The deformed portion 37 shown in FIG. 5 shows an example in which the biasing portion 373 is located laterally of the clamping portion 371 and moves up and down in the same direction as the clamping portion 371. However, it is not limited to this. As shown in FIG. 6, the biasing portion 373 may be provided on the side of the support table 351 (rail member 331) and be capable of moving up and down in the direction opposite to the clamping portion 371 so as to protrude or retract from the support table 351. In this case, during the horizontal movement of the support table 351, the biasing portion 373 is retracted below the support table 351 (FIG. 6(A)). Then, when the support table 351 moves to the pressing position of the deformed portion 37 and temporarily stops, and the clamping portion 371 descends to clamp the coil piece C (after clamping), the biasing portion 373 protrudes upward (vertically) from the support table 351, and the inclined surface 373S abuts against the short side SS of the coil piece C protruding horizontally from the support table 351 and is bent upward, for example, to form the bent portion B0 (FIG. 6(B)). In this example, the surface of the coil piece C on the side contacting the clamping portion 371 is valley-folded at the bent portion B0.

[0054] After deformation, as shown in FIG. 6(C), the clamping portion 371 ascends, the biasing portion 373 descends below the support table 351, and the deformed coil piece C is discharged from the deformed portion 37 by the conveying portion 33 (FIG. 4).

[0055] As a result, for example, as shown in FIG. (D), when one long-side region LS1 and the short side SS of the coil piece C are located within the reference plane SF0 and the reference plane SF0 is held horizontally, with the folding portion B0 as a boundary, the other long-side region LS2 is bent such that its other end T2 is located above (or below) the reference plane SF0 with respect to its end T1 on the short-side SS side. In other words, the bending device 30 bends the coil piece C from the position of the folding portion B0 (indicated by the dashed line in the upper part of FIG. (D)) such that the angle formed between the reference plane SF0 (long-side region LS1) and the long-side region LS2 is the angle α.

[0056] When the deformation of one coil piece C (C1) is completed in this way, the coil piece C (C1) is taken out from the support table 351 by a robot or the like (not shown) and transferred to the downstream process (bonding device 20).

[0057] Thereafter, the next coil piece C (C2) is similarly supplied onto the support table 351 and deformed.

[0058] The bending device 30 performs such bending processing on all the coil pieces C that constitute the spiral structure, excluding the coil pieces C that are the both ends (starting end and ending end) of the coil 50. As a result, good bonding can be performed in the bonding device 20 in the downstream process.

[0059] <Bonding device 20> Next, the bonding device 20 will be described. FIG. 7 is a front view showing an overview of the bonding device 20. The bonding device 20 is a device for cold-pressure bonding two flat conductors (coil pieces) C (C1, C2), and includes a first holding portion 11 and a second holding portion 12 that can sandwich the two flat conductors C (C1, C2), a drive portion 13 that moves them, and a control portion 14, and forms a spiral structure body that becomes a coil 50 by joining a plurality of flat conductors (coil pieces) C in a belt shape that can become a spiral shape when connected continuously.

[0060] The first holding part 11 is movable along the first direction (the longitudinal direction of the flat conductor; the X direction in the figure), and is composed of a first upper holding body 111 and a first lower holding body 112. The first upper holding body 111 and the first lower holding body 112 are arranged to face each other and have an opposing surface OS1 along the first direction. In this embodiment, for convenience of explanation, the upper holding body in the illustration is referred to as the first upper holding body 111, and the lower holding body in the illustration is referred to as the second lower holding body 122. However, the up and down directions of these are not necessarily limited to the up and down in the vertical direction. That is, FIG. 7 may be a top view of the bonding device 20. In that case, the first upper holding body 111 is, for example, the holding body on the back side, and the first lower holding body 112 is, for example, the holding body on the front side. Also, the first upper holding body 111 may be, for example, the holding body on the left side, and the first lower holding body 112 may be, for example, the holding body on the right side.

[0061] The first upper holding body 111 and the first lower holding body 112 are movable along the X direction, and the opposing surface OS1 along the X direction is movable so as to abut or separate from each other along the second direction (the thickness direction of the flat conductor; the Y direction in the figure). The Y direction is a direction different from the X direction, for example, a direction orthogonal to the X direction.

[0062] The second holding part 12 has the same configuration as the first holding part 11 and is arranged to face the first holding part 11. The second holding part 12 and the first holding part 11 have an opposing surface OS2 along the second direction. That is, without going into detailed description, the second holding part 12 is movable along the X direction and is composed of a second upper holding body 121 and a second lower holding body 122. The description of "up and down" of the second upper holding body 121 and the second lower holding body 122 is the same as that of the first holding part 11.

[0063] The second upper holding body 121 and the second lower holding body 122 are movable along the X direction, and the opposing surface OS1 is movable so as to abut or separate from each other along the Y direction.

[0064] In FIGS. 7 to 9, although detailed illustrations are omitted, the first upper holder 111, the first lower holder 112, the second upper holder 121, and the second lower holder 122 have portions at their tips that substantially hold the coil piece C (coil piece holding portions 111T, 112T, 121T, 122T, see FIG. 10). The coil piece holding portions 111T, 112T, 121T, 122T are configured in a claw shape that protrudes horizontally from, for example, the first upper holder 111, the first lower holder 112, the second upper holder 121, and the second lower holder 122 so as to be able to locally hold (grip) only the vicinity of the pressure contact portion (joint portion) of the coil piece C. That is, in FIGS. 7 to 9, the operations of the first upper holder 111, the first lower holder 112, the second upper holder 121, and the second lower holder 122 are described, but these are the same as the operations of the coil piece holding portions 111T, 112T, 121T, 122T, and can be read as these.

[0065] The first holding portion 11 and the second holding portion 12 are biased by a biasing member (for example, a coil spring) 15 in a direction of separating from each other along the X direction. Although not shown, the first upper holder 111 and the first lower holder 112 are biased by a biasing member (for example, a coil spring) in a direction of separating from each other along the Y direction, and the second upper holder 121 and the second lower holder 122 are biased by a biasing member (for example, a coil spring) in a direction of separating from each other along the Y direction.

[0066] The drive unit 13 moves the first holding portion 11 and the second holding portion 12 along the X direction and the Y direction via a drive transmission portion (not shown) according to an instruction from the control unit 14.

[0067] On the outer sides of the first holding part 11 and the second holding part 12 in the X direction, there is provided a movement restricting part 17 that restricts the movement of one flat conductor (for the sake of convenience in FIGS. 7 to 9, the first coil piece C1) and the other flat conductor (for the sake of convenience in FIGS. 7 to 9, the second coil piece C2) in a predetermined direction. The movement restricting part 17 abuts on both surfaces of the first coil piece C1 (the second coil piece C2) respectively to restrict the movement in the Y direction. Also, while biasing both coil pieces C1 and C2 in one direction along the X direction (the direction in which the first coil piece C1 and the second coil piece C2 approach each other), the movement in the other direction along the X direction (the direction in which the first coil piece C1 and the second coil piece C2 separate from each other) is restricted. More specifically, the movement restricting part 17 is a roller body biased by a biasing member (such as a coil spring or a leaf spring) 171 toward the center direction of the first holding part 11 and the second holding part 12. The movement restricting part 17 is formed with uneven shapes (for example, a serrated uneven shape) not shown along the circumferential direction on both end sides in the direction of the rotation center axis, and holds the flat conductor C at the roller body part. For example, regarding the movement restricting parts 17A and 17B of the first holding part 11, the movement restricting part 17A is rotatable clockwise, and the movement restricting part 17B is rotatable counterclockwise and biases the first coil piece C1 in the left direction (the approaching (pressing) direction) in the figure along the X direction (that is, it can also be said to be a pressing direction biasing member). On the other hand, when the first coil piece C1 moves in the right direction in the figure along the X direction, the movement restricting part 17A tries to rotate counterclockwise, and the movement restricting part 17B tries to rotate clockwise, but the uneven shapes provided along the circumferential direction at both ends of the center axis engage with each other to prevent rotation, so the movement of the first coil piece C1 in the right direction is restricted. The same applies to the second holding part 12.

[0068] Also, on the outer sides of the first holding part 11 and the second holding part 12 in the Y direction, a pressing part 18 is provided. The pressing part 18 presses the first upper holding body 111 and the first lower holding body 112 so that they come into contact with each other, and also presses the second upper holding body 121 and the second lower holding body 122 so that they come into contact with each other.

[0069] FIGS. 8 and 9 are front views in which the first holding part 11 and the second holding part 12 are extracted, and are views showing the states of these movements.

[0070] FIG. 8 is a diagram for explaining the movement mainly along the Y direction of the first holding part 11 (the first upper holding body 111 and the first lower holding body 112) and the second holding part 12 (the second upper holding body 121 and the second lower holding body 122).

[0071] The state shown in FIG. (A) is a position where the opposing surfaces OS1 of the first upper holding body 111 and the first lower holding body 112 (similarly for the second upper holding body 121 and the second lower holding body 122) are most separated from each other in the Y direction. This position is hereinafter referred to as the Y-direction separation position. Also, this state is a position where the opposing surfaces OS2 of the first holding part 11 and the second holding part 12 are most separated from each other in the X direction. This position is hereinafter referred to as the X-direction separation position.

[0072] FIG. (B) shows a state where the opposing surfaces OS1 of the first upper holding body 111 and the first lower holding body 112 have moved from the state shown in FIG. (A) to the position where they are closest to each other. In this state, the first holding part 11 sandwiches the first coil piece C1 (the wide surface WS thereof) by the first upper holding body 111 and the first lower holding body 112, and the second holding part 12 sandwiches the second coil piece C2 (the wide surface WS thereof) by the second upper holding body 121 and the second lower holding body 122.

[0073] The first holding part 11 projects and sandwiches the first coil piece C1 from the opposing surface OS2 along the Y direction toward the second holding part 12. Similarly, the second holding part 12 projects and sandwiches the second coil piece C2 from the opposing surface OS2 along the Y direction toward the first holding part 11. The protruding amounts A1 of the first coil piece C1 from the first holding part 11 and A2 of the second coil piece C2 from the second holding part 12 will be described later.

[0074] In the following description, the position where the opposing surfaces OS1 of the first upper holding body 111 and the first lower holding body 112 (the second upper holding body 121 and the second lower holding body 122) are closest to each other is referred to as the clamping position. That is, the first upper holding body 111 and the first lower holding body 112 (the second upper holding body 121 and the second lower holding body 122) are movable between the clamping position and the Y-direction separation position.

[0075] Also, as shown in FIG. (C), between the clamping position and the Y-direction separation position, a release position (in the Y direction) of the clamping is included. The release position in the Y direction (hereinafter referred to as the Y-direction release position) is at a distance smaller than the Y-direction separation position, and is the position where the first upper holding body 111 and the first lower holding body 112 (the second upper holding body 121 and the second lower holding body 122) are separated.

[0076] It should be noted that it is also possible to move from the Y-direction release position in FIG. (C) to the position where the opposing surface OS1 of the first upper holding body 111 and the first lower holding body 112 (the second upper holding body 121 and the second lower holding body 122) is closest, and transition to the state shown in FIG. (B).

[0077] It should be noted that in FIG. 8, the positions along the X direction of the first holding portion 11 and the second holding portion 12 both maintain the X-direction separation position.

[0078] FIG. 9 is a diagram for explaining the movement mainly along the X direction of the first holding portion 11 and the second holding portion 12.

[0079] FIG. 9(A) shows the position where the first holding portion 11 and the second holding portion 12 have moved along the X direction so that the opposing surface OS2 is closest from the state of FIG. 8(B). Hereinafter, this position is referred to as the proximity position. That is, the first holding portion 11 and the second holding portion 12 can move in the X direction between the X-direction separation position shown in FIG. 8 and the proximity position shown in FIG. 9(A). Note that even at the proximity position, the first holding portion 11 and the second holding portion 12 do not contact each other.

[0080] In the clamping position (FIG. 8(B)), since the first holding portion 11 clamps the first coil piece C1 by protruding it by the protruding amount A, and the second holding portion 12 clamps the second coil piece C2 by protruding it by the protruding amount A2, when the first holding portion 11 and the second holding portion 12 are in the proximity position (FIG. 9(A)), the first holding portion 11 and the second holding portion 12 do not contact each other, but the first coil piece C1 and the second coil piece C2 contact (join) each other and are further in a state of pressing against each other. That is, the protruding amount A1 of the first coil piece C1 from the first holding portion 11 and the protruding amount A2 of the second coil piece C2 from the second holding portion 12 are each set to an amount slightly longer than the length at which they contact each other when the first holding portion 11 and the second holding portion 12 are in the proximity position (the amount by which they can press against each other after contacting).

[0081] Also, as shown in FIG. 9(B), between the proximity position (FIG. 9(A)) and the clamping position (FIG. 8(B)), a release position (in the X direction) of the pressing is included. The release position in the X direction (hereinafter, the X-direction release position) is at a distance smaller than the X-direction separation position (for example, the X-direction separation position shown in FIG. 8(C)) and is a position where the first holding portion 11 and the second holding portion 12 are separated. When the first holding portion 11 and the second holding portion 12 are in the X-direction release position, the first upper holding body 111 and the first lower holding body 112 also separate and move to the Y-direction release position (for example, the Y-direction release position shown in FIG. 8(C)), and the second upper holding body 121 and the first lower holding body 112 also separate and move to the Y-direction release position.

[0082] Note that it is also possible to transition from the X-direction release position in FIG. 9(B) to the state (proximity position) shown in FIG. 9(A).

[0083] Note that, in order to ensure the clamping (holding) of the flat conductors C1 and C2 of the first holding part 11 and the second holding part 12, it is desirable to apply anti-slip treatment to the holding surfaces of the flat conductors (the holding surfaces of the coil piece holding parts 111T, 112T, 121T, and 122T). The anti-slip treatment in this case is, for example, a treatment to increase the frictional resistance or a treatment to increase the adsorptivity. Specifically, for example, fine unevenness processing such as sandblasting is performed, or fine particles or the like are adhered to increase the frictional resistance. Also, so-called sawtooth-shaped unevenness may be formed so that the frictional resistance in one direction is higher than the frictional resistance in the other direction. Further, the adsorptive force may be increased by creating a vacuum state, or the adsorptive force may be increased by the pressure of the vacuum or the atomic force by mirror finishing. Note that if the degree of unevenness processing is large, a non-uniform electric field will occur (corona discharge), and in the case of manufacturing a coil, there is a risk of causing damage to the coating or the like. Therefore, fine unevenness processing to the extent that can be formed by sandblasting is desirable.

[0084] Also, the coil piece holding parts 111T, 112T, 121T, and 122T may be configured in a groove shape capable of accommodating the coil piece C (the holding portion thereof).

[0085] The drive part 13 moves the first holding part 11 and the second holding part 12 between an X-direction separation position, an X-direction release position, and a proximity position along the X direction via a drive transmission part (not shown) according to an instruction from the control part 14. The drive transmission part can be configured with an appropriate configuration such as a linear guide (linear guide), a cam mechanism, or a rack and pinion. Also, the drive part 13 moves the first upper holding body 111 and the first lower holding body 112 between a Y-direction separation position, a clamping position, and a Y-direction release position along the Y direction via a drive transmission part (not shown) according to an instruction from the control part 14, and at the same time, moves the second upper holding body 121 and the second lower holding body 122 between a Y-direction separation position, a clamping position, and a Y-direction release position.

[0086] As a result, the drive unit 13 can control the first holding unit 11 and the second holding unit 12 to be in any one of a clamping state (Fig. 8(B)), a pressure contact state (Fig. 9(A)), a pressure contact release state (Fig. 8(C), Fig. 9(B)), a retracted state (Fig. 8(A)), or a transition state between two of these states.

[0087] More specifically, in the clamping state, the first upper holding body 111 and the first lower holding body 112 of the first holding unit 11 are moved from the Y-direction separation position (Fig. 8(A)) to the clamping position (Fig. 8(B)) along the Y direction, and the first coil piece C1 is clamped between the first upper holding body 111 and the first lower holding body 112. At the same time, the second upper holding body 121 and the second lower holding body 122 of the second holding unit 12 are moved from the Y-direction separation position (Fig. 8(A)) to the clamping position (Fig. 8(B)) along the Y direction, and the second coil piece C2 is clamped between the second upper holding body 121 and the second lower holding body 122.

[0088] As described above, the first holding unit 11 projects and clamps the first coil piece C1 from the opposing surface OS2 along the Y direction by a protruding amount A1 in the direction of the second holding unit 12, and the second holding unit 12 projects and clamps the second coil piece C2 from the opposing surface OS2 along the Y direction by a protruding amount A2 in the direction of the first holding unit 11.

[0089] Also, in the clamping state, the first upper holding body 111 and the first lower holding body 112 of the first holding unit 11 at the Y-direction release position (Fig. 8(C)) are moved to the clamping position (Fig. 8(B)), and the first coil piece C1 is clamped between the first upper holding body 111 and the first lower holding body 112. At the same time, the second upper holding body 121 and the second lower holding body 122 of the second holding unit 12 at the Y-direction release position (Fig. 8(C)) may be moved to the clamping position (Fig. 8(B)), and the second coil piece C2 is clamped between the second upper holding body 121 and the second lower holding body 122.

[0090] In the crimped state, the first holding portion 11 and the second holding portion 12 in the clamped state are moved from the X-direction spaced position (FIG. 8(B)) to the proximity position (FIG. 9(A)) along the X direction against the biasing force of the biasing member 15. At this time, the first coil piece C1 protrudes from the first holding portion 11, and the second coil piece C2 protrudes from the second holding portion 12. These protrusion amounts A1 and A2 are each slightly longer than the length at which the opposing end faces in the longitudinal direction of the strip come into contact with each other when the first holding portion 11 and the second holding portion 12 are in the proximity position (FIG. 9(A)). That is, immediately before moving to the proximity position, the opposing end faces of the first coil piece C1 and the second coil piece C2 first come into contact (abut). Thereafter, by moving the first holding portion 11 and the second holding portion 12 to the proximity position (FIG. 9(A)) by the drive unit 13, the abutting end faces TS1 and TS2 of the first coil piece C1 and the second coil piece C2 are abutted against each other and pressed and joined. More specifically, by pressing the end faces TS1 and TS2 of the first coil piece C1 and the second coil piece C2 against each other, the stable oxide film formed on the end faces TS1 and TS2 is removed, and these are plastically deformed to expose the active state surfaces. By bringing the active state surfaces closer to each other to within 10 angstroms or less, an atomic bond between the metals is caused to perform cold welding. That is, by cold welding, the lengths of the first coil piece C1 and the second coil piece C2 in the longitudinal direction of the strip are compressed (shortened) after crimping compared to before crimping. And the amount of shortening is the same in the first coil piece C1 and the second coil piece C2.

[0091] That is, when the length of the first coil piece C1 before crimping is L01 and the length of the second coil piece C2 before crimping is L02, the first coil piece C1 is shortened to a length of L01' and the second coil piece C2 is shortened to a length of L02' by crimping, and the amount of shortening SC is the same for both (SC = L01 - L01' = L02 - L02').

[0092] Note that after moving to the proximity position, since the first holding portion 11 and the second holding portion 12 do not come closer to each other any further, further pressing of the end faces of the first coil piece C1 and the second coil piece C2 against each other stops.

[0093] In the press contact state, the first upper holder 111 and the first lower holder 112, and the second upper holder 121 and the second lower holder 122, which are at the Y-direction release position (Fig. 8(C)) or the Y-direction release position and the X-direction release position (Fig. 9(B)), are moved to the clamping position (Fig. 8(B)), and the first holding portion 11 and the second holding portion 12 are moved to the proximity position against the biasing force of the biasing member 15, and the end surface TS1 of the first coil piece C1 and the end surface TS2 of the second coil piece C2 are abutted and pressed to perform cold press welding (Fig. 9(A)).

[0094] In the press contact release state, the first holding portion 11 and the second holding portion 12 in the press contact state are controlled to move in a direction of separating along the X direction, and the first holding portion 11 and the second holding portion 12 are moved to the X-direction release position. Also, the first upper holder 111 and the first lower holder 112 are controlled to move in a direction of separating along the Y direction, and the first upper holder 111 and the first lower holder 112 are moved to the first Y-direction release position. Further, the second upper holder 121 and the second lower holder 122 are controlled to move in a direction of separating along the Y direction, and the second upper holder 121 and the second lower holder 122 are moved to the second Y-direction release position (Fig. 9(B)).

[0095] In the press contact state, finally, the first holding portion 11 and the second holding portion 12 reach the proximity position, and further pressing of the first coil piece C1 and the second coil piece C2 stops. Therefore, after the press contact state, the press contact release state is passed through to transition to the clamping state in order to repeat the pressing, and the first coil piece C1 and the second coil piece C2 are re-clamped by the first holding portion 11 and the second holding portion 12.

[0096] Here, when changing from the press contact state to the press contact release state (when the press contact is released), a biasing force acts in a direction in which the first upper holder 111 and the first lower holder 112 (similarly for the second upper holder 121 and the second lower holder 122) are separated by the biasing member 15. However, a part of the metal (the expanded joint surface) that has flowed due to plastic deformation of the metal by pressing adheres to the first holding portion 11 and the second holding portion 12, and there may be a case where the first upper holder 111 and the first lower holder 112 (similarly for the second upper holder 121 and the second lower holder 122) cannot be separated only by the biasing force of the biasing member 15.

[0097] Therefore, in the present embodiment, in the pressure contact release state (FIG. 9(B)), in addition to the biasing force of the biasing member 15, the first holding portion (the first upper holding body 111 and the first lower holding body 112) is moved in a direction away from the second holding portion 12 along the X direction via the drive transmission portion to return to the first X-direction release position, and the second holding portion (the second upper holding body 121 and the second lower holding body 122) is moved in a direction away from the first holding portion 11 along the X direction via the drive transmission portion to return to the second X-direction release position.

[0098] Even when the first holding portion 11 and the second holding portion 12 are forcibly moved in a direction to separate them in addition to the biasing member 15, the movement of the first coil piece C1 and the second coil piece C2 in a direction to separate from each other along the X direction is restricted by the movement restricting portion 17.

[0099] In the retracted state, the first holding portion 11 and the second holding portion 12 in the pressure contact state, the pressure contact release state, or the clamping state are controlled to move to the X-direction separation position along the X direction, and the first upper holding body 111 and the first lower holding body 112 are moved along the Y direction to move to the Y-direction separation position, and the second upper holding body 121 and the second lower holding body 122 are moved along the Y direction to move to the Y-direction separation position (FIG. 8(A)).

[0100] Here, the bonding device 20 can perform cold pressure welding by pressing flat conductors once, but in order to stabilize the bonding surface, it is desirable to repeat the pressing a plurality of times for one bonding portion.

[0101] For example, in the cold pressure welding of one bonding portion CP, the bonding device 20 shortens the pressing time for one time (for example, within 5 seconds or the like), increases the number of pressing times (for example, about 3 to 10 times), and further shortens the interval between pressings to such an extent that the bonding portion does not oxidize, and then performs the pressing.

[0102] More specifically, the amount of insertion (compression amount) of the joining device 20 in one operation is, for example, about 0.5 mm for both the first coil piece C1 and the second coil piece C2. For one joint portion CP, for example, pressing within 5 seconds per operation is repeated about 3 to 10 times to compress it by about 1 mm or more (preferably 1.5 mm or more, specifically about 2 mm). Thereby, a stable joint surface can be obtained.

[0103] As described above, the joining device 20 of the present embodiment repeatedly performs the clamping state, the pressure welding state, and the pressure welding release state to cold pressure-weld the first coil piece C1 and the second coil piece C2.

[0104] After the clamping state (FIG. 8(B)), when the pressure welding state (FIG. 9(A)) is reached and the first holding portion 11 and the second holding portion 12 move to the proximity position, through the contact (abutment) of the end faces of the first coil piece C1 and the second coil piece C2, the end faces are pressed against each other and cold pressure-welded. Since the first holding portion 11 and the second holding portion 12 in the proximity position (pressure welding state) do not approach each other any further, once they transition to the pressure welding release state (FIG. 9(B)), the first holding portion 11 and the second holding portion 12 are moved to the Y-direction release position to release the clamping of the flat conductors C1 and C2, and the first holding portion 11 and the second holding portion 12 are moved to the X-direction release position. Then, the first holding portion 11 holds the first coil piece C1 so that a predetermined protrusion amount A1 protrudes, and the second holding portion 12 holds the first coil piece C2 so that a protrusion amount A2 protrudes, and by transitioning to the pressure welding state again, a plurality of pressings can be repeated for one joint portion.

[0105] That is, the X-direction release position is a position where the first holding portion 11 can be instructed to protrude the first coil piece C1 by the protrusion amount A1, and the second holding portion 12 can be instructed to protrude the second coil piece C2 by the protrusion amount A2 and clamp it.

[0106] Note that the X-direction release position does not necessarily have to be a position where each of the flat conductors protrudes by the protruding amounts A1 and A2 when it subsequently transitions to the clamped state (while remaining at that position). In that case, in the clamped state, after moving the first holding portion 11 and the second holding portion 12 to positions where each of the flat conductors protrudes by the protruding amounts A1 and A2, they may be clamped.

[0107] Also, as shown by the dashed circles in FIG. 9(A), in addition to the movement restricting portion 17, the bonding apparatus 20 may further include another movement restricting portion (fixed member 16) that restricts the first coil piece C1 and the second coil piece C2 from moving in a direction of separation along the X direction, and that restricts the first coil piece C1 and the second coil piece C2 from moving along the Y direction.

[0108] The fixed member 16 has, as an example, two sets of columnar protrusions 161 and 162 that are slightly wider than the plate thickness of the non-plastically deformed portions of the first coil piece C1 and the second coil piece C2 as shown by the circles in FIG. (A) and are narrower than the length in the plate thickness direction of the bonding portion CP, and a set of restricting surfaces 163A provided on the outer sides of both ends in the plate thickness direction of the bonding portion (for example, a protrusion (or plate) 163 having a prismatic shape).

[0109] Accordingly, when the first holding part 11 and the second holding part 12 are moved to the Y-direction release position and the X-direction release position or the Y-direction separation position and the X-direction separation position by the drive part 13 in the compression release state (Fig. 9(B)) or the standby state (Fig. 8(A)), even when the first coil piece C1 and the second coil piece C2 are in close contact with the first holding part 11 and the second holding part 12, the movement of the first coil piece C1 and the second coil piece C2 is restricted. Specifically, for example, the movement of the first coil piece C1 in the direction of separating from the second coil piece C2 along the X direction (the right direction in Fig. 9(A)) is restricted by the columnar protrusion 161, and the movement of the second coil piece C2 in the direction of separating from the first coil piece C1 along the X direction (the left direction in Fig. 9(B)) is restricted by the protrusion 162. Also, the movement of the first coil piece C1 and the second coil piece C2 in the upward or downward direction shown along the Y direction is restricted by the protrusion 161 having the restricting surface 163A.

[0110] In this way, the first coil piece C1 and the second coil piece C2 can maintain the position immediately after pressure contact, and the stability of the joint surface of the joint part CP can be enhanced, so that it is possible to prevent the joint part CP from separating along with the first holding part 11 and the second holding part 12 after pressure contact.

[0111] Note that the fixing member 16 is not limited to the protrusion or the plate, and may be a rubber pressing member or the like. Also, the fixing member 16 may not be provided. Further, depending on the conditions of pressure contact, these fixing members 16 may not be provided.

[0112] In the above-described embodiment, the configuration in which the first holding portion 11 and the second holding portion 12 stop at the X-direction release position and the Y-direction release position in the pressure contact release state has been described as an example. However, although the first holding portion 11 and the second holding portion 12 pass through the X-direction release position and the Y-direction release position, they may not stop at these positions. That is, the first upper holding body 111 and the first lower holding body 112 (similarly for the second upper holding body 121 and the second lower holding body 122) may move without stopping between the clamping position, the Y-direction release position, and the Y-direction separation position, and the first holding portion 11 and the second holding portion 12 may move without stopping between the proximity position, the X-direction release position, and the X-direction separation position.

[0113] Conventionally, cold pressure welding has been used when joining round wires to each other. However, according to the joining device 20 of the present embodiment described above, good and stable cold pressure welding between flat conductors can be performed.

[0114] Here, with reference to FIG. 10, the coil piece holding portions 111T, 112T, 121T, and 122T of the first holding portion 11 and the second holding portion 12 will be further described. FIG. 10 is a diagram showing the coil piece holding portions 111T, 112T of the first holding portion 11 and the coil piece holding portions 121T, 122T of the second holding portion 12 extracted. FIG. (A) of the same figure is a top view of the clamping state (FIG. 8(B)), and FIG. (B) of the same figure is a front view of the joining device 20 as viewed from the lower side (Z-direction lower side) of FIG. (A) (the coil piece C is a side view). Further, FIG. (C) of the same figure is a top view of the pressure contact state (FIG. 9(A)), and FIG. (D) of the same figure is a front view of the joining device 20 as viewed from the lower side (Z-direction lower side) of FIG. (B) (the coil piece C is a side view).

[0115] In the present embodiment, the coil pieces C (C1, C2) are pressure contacted at their straight portions, and a spiral structure is formed while adding and pressure contacting the coil pieces C one by one.

[0116] The portion to be pressure contacted is, for example, the portion constituting the long side of the one-turn region CR (long side regions LS1, LS2), and is a region other than the direction conversion portion TN of the one-turn region CR. Thereby, the pressure contact portion (joint portion CP) is located at a part (for example, near the approximate center) of the long side of the one-turn region CR.

[0117] In addition, the joining of the coil piece C1 and the coil piece C2 is to join one side having the bent portion B0 of the coil piece C1 (for example, the long side region LS2) and one side having the bent portion B0 of the coil piece C2 (for example, the long side region LS2). Alternatively, the joining of the coil piece C1 and the coil piece C2 is to join one side not having the bent portion B0 of the coil piece C1 (for example, the long side region LS1) and one side not having the bent portion B0 of the coil piece C2 (for example, the long side region LS1).

[0118] Here, the joining of the coil piece C1 and the coil piece C2 joins one side (long side region LS2) having the bent portion B0 of the coil piece C1 and one side (long side region LS2) having the bent portion B0 of the coil piece C2 as shown in FIG. (A) of this figure.

[0119] That is, as shown in this example, in the case of a coil piece C (such as a U-shaped or C-shaped coil piece C) having opposing long side regions LS1 and LS2, for example, first, the first holding portion 11 (coil piece holding portions 111T and 112T) is inserted and held in the Z direction with respect to, for example, the long side region LS2 of the coil piece C1 from the lower side shown in FIG. (A) of this figure, and the second holding portion 12 (coil piece holding portions 121T and 122T) is inserted and held in the Z direction with respect to, for example, the long side region LS2 of the coil piece C2, and the end faces TS1 and TS2 of both are pressed against each other. Then, for example, the other long side region LS1 of the coil piece C2 is pressed against one long side region LS1 of the next coil piece C (C3), not shown here, at another timing.

[0120] Therefore, when the long side region LS2 of the coil piece C1 and the long side region LS2 of the coil piece C2 are held by the first holding portion 11 and the second holding portion 12, it is necessary to avoid interference between the other long side region LS1 that is not pressed at that timing and the first holding portion 11 and the second holding portion 12 (coil piece holding portions 111T, 112T, 121T, 122T).

[0121] Here, when pressing the coil piece C before deformation (a flat coil piece C in which the long-side regions LS1, LS2, and the short side SS are located in substantially the same plane, and the coil piece C in which the bent portion B0 is not formed), as shown in the upper part of FIG. 3(B), when the coil piece holding portions 111T, 112T, 121T, and 122T are inserted at an arbitrary distance in the short side SS direction of the coil piece C, there is a risk of interference with the other long-side region LS1 that is not pressed at that timing, as shown by the tip broken line portions of the coil piece holding portions 111T, 112T, 121T, and 122T shown in FIG. 10(A).

[0122] That is, in this case, the tip portions (the upper-end portions in FIG. 10(A)) of the first holding portion 11 and the second holding portion 12 (the coil piece holding portions 111T, 112T, 121T, and 122T) must be set (controlled) so as to be surely arranged in the inner peripheral portion of the one-turn region CR, as shown by the diagonal hatching in FIG. 10(A).

[0123] In addition, since the spiral structure of the present embodiment is configured by sequentially connecting the coil pieces C, as the number of joints progresses, it will be continuous downward in FIG. 10(B), and the coil piece C (the joined coil piece CC) can be arbitrarily expanded and contracted by the spring-like configuration. That is, the joined coil piece CC expands and contracts unspecifiedly due to its own weight, and the state of expansion and contraction also changes depending on the number of joints of the unit coil piece C0. Therefore, the shape of the joined coil piece CC when held by the first holding portion 11 and the second holding portion 12 (the interval between the one-turn regions CR when inserting the first holding portion 11 and the second holding portion 12 (the coil piece holding portions 111T, 112T, 121T, and 122T)) becomes unspecified (unstable), and the setting (or control) for avoiding interference with the other long-side region LS1 becomes more complicated.

[0124] Therefore, in the present embodiment, the bending device 30 is used to deform the coil piece C into a predetermined shape in advance, and the shape of the coil piece C when held by the first holding portion 11 and the second holding portion 12 is maintained in the predetermined shape.

[0125] Specifically, before the pressure welding by the bonding device 20, a bent portion B0 is formed by the bending device 30 so that the long side region LS1 of the coil piece C is inclined at a predetermined angle α with respect to the other long side region LS2.

[0126] Also, as shown in FIG. 10(B), the angle α of the bent portion B0 is, for example, an angle at which the long side region LS2 is inclined with respect to the long side region LS1 so that the long side region LS1 on the reference plane SF0 of the coil piece C1 (the same applies to the coil piece holding portion 111T) and the coil piece holding portion 112T do not interfere. Also, it is an angle at which the long side region LS2 is inclined with respect to the long side region LS1 so that the long side region LS1 on the reference plane SF0 of the coil piece C2 (the same applies to the coil piece holding portion 122T) and the coil piece holding portion 121T do not interfere.

[0127] More specifically, one coil piece C1 is substantially held by the coil piece holding portions 111T and 112T in the clamping region P1. In this case, the coil piece C1 (long side region LS2) is bent at an angle α such that the separation distance LL1 in the clamping direction (Y direction) in the side view of the long side region LS1 and the long side region LS2 of the coil piece C1 is larger than the thickness d1 in the clamping direction of the coil piece holding portion 112T (111T).

[0128] Similarly, the other coil piece C2 is substantially held by the coil piece holding portions 121T and 122T in the clamping region P2. In this case, the coil piece C2 (long side region LS2) is bent at an angle α such that the separation distance LL2 in the clamping direction (Y direction) in the side view of the long side region LS1 and the long side region LS2 of the coil piece C2 is larger than the thickness d2 in the clamping direction of the coil piece holding portion 121T (122T).

[0129] With such a configuration, unstable expansion and contraction of the joined coil piece CC can be avoided, and even when the length in the spiral advancing direction increases, the interval between the regions CR for each turn can be maintained at a (substantially) predetermined interval.

[0130] Therefore, as shown in FIG. (B), a space (space in the Y direction and thickness direction) can be reliably secured when inserting the first holding portion 11 and the second holding portion 12 (coil piece holding portions 111T, 112T, 121T, 122T). Also, as shown by the dashed line in FIG. (C), the positions of the tip portions of the first holding portion 11 and the second holding portion 12 (one end portion in the band short side direction of the coil piece C) can also be made arbitrary (it is no longer necessary to surely arrange them in the inner peripheral region of the one-turn region CR). As a result, complicated settings and controls for avoiding interference between the first holding portion 11 and the second holding portion 12 and other long side regions LS2 become unnecessary, and the pressing speed can be significantly improved.

[0131] Also, it is desirable to secure a space in the X direction of FIG. 10 when inserting the first holding portion 11 and the second holding portion 12 (coil piece holding portions 111T, 112T, 121T, 122T), and this will be described with reference to FIG. 11.

[0132] FIG. 11 is a top view corresponding to FIGS. 10(A) and 10(C), further explaining the formation position of the bent portion B0 using the U-shaped coil piece C (C1, C2) as an example.

[0133] In the case of the U-shaped coil piece C, although it will be described in detail later, two coil pieces C1 and C2 are arranged to face each other, and the long side regions (here, the long side region LS2) where the bent portion B0 is formed are connected to each other, or the long side regions (here, the long side region LS1) where the bent portion B0 is not formed are connected to each other to form a spiral structure.

[0134] And when connecting the long side regions LS2 where the bent portion B0 is formed to each other, the coil piece holding portions 111T, 112T, 121T, 122T sandwich the region between the end faces TS1, TS2 that are pressed against the bent portion B0 (see FIG. 10(A)). That is, the bent portion B0 is formed at a position such that the coil piece holding portions 111T, 112T, 121T, 122T can surely sandwich the region between the bent portion B0 and the end faces TS1, TS2 that are pressed against each other.

[0135] Specifically, as shown in FIG. 11, a fold B0 is formed in the vicinity of the direction conversion portion TN of the long side region LS2, excluding the direction conversion portion TN.

[0136] More specifically, it is desirable to provide the fold B0, for example, in a range less than 30% from the end thereof with respect to the "maximum length in the band longitudinal direction of the long side LS constituting the one-turn region CR (the maximum length in the band longitudinal direction of the region that is to become the long side LS constituting the one-turn region CR)" LMAX.

[0137] For example, as shown in FIG. 11(A), a virtual one-turn region of a virtual spiral structure in a state where the end faces TS1 and TS2 of the coil pieces C1 and C2 are in contact with each other (state before press contact) is defined as a virtual one-turn region CR'. In this case, the long side LS' constituting the virtual one-turn region CR' is the total length of the long side region LS2 of the coil piece C1 and the long side region LS2 of the coil piece C2. By press-contacting the long side regions LS2 in a state where they are in contact with each other and shortening both of them, the long side LS constituting the one-turn region CR can be obtained.

[0138] That is, the length in the band longitudinal direction of the long side LS' constituting the virtual one-turn region CR' (the total length of the long side region LS2 of the coil piece C1 and the long side region LS2 of the coil piece C2) is the above-mentioned "maximum length LMAX in the band longitudinal direction of the long side LS constituting the one-turn region CR" (FIG. (B) thereof).

[0139] Then, it is desirable to form the fold B0 in a range less than 30% and in the long side region LS2 (region excluding the direction conversion portion TN indicated by hatching) from the end on the short side SS side with respect to the maximum length LMAX (the total length of the long side region LS2 of the coil piece C1 and the long side region LS2 of the coil piece C2), that is, at a position where the length LB1 < LMAX × 30%.

[0140] By doing so, as the sandwiching regions P1 and P2 (see FIG. 10) of the coil piece holding portions 111T, 112T, 121T, and 122T, on the long side LS' of the virtual one-turn region CR', a length of 40% or more of the maximum length LMAX (2 × length LB2 ≧ LMSAX × 40%) can be ensured on the left and right in the X direction including the center thereof.

[0141] Alternatively, in each of the coil pieces C1 and C2, the bent portion B0 may be formed at a position where the length LB1 from the end on the short side SS to the bent portion B0 is equal to or less than the length LB2 from the bent portion B0 to the end faces TS (TS1, TS2).

[0142] By doing so, as the sandwiching regions P1 and P2 of the coil piece holding portions 111T, 112T, 121T, and 122T (see FIG. 10), on the long side LS' of the virtual one-turn region CR', a length of 50% or more of the maximum length LMAX (2 × length LB2 ≥ LMSAX × 50%) can be ensured on the left and right in the X direction including the center thereof.

[0143] If the length that can be ensured as the sandwiching regions P1 and P2 of the coil piece holding portions 111T, 112T, 121T, and 122T is short, there is a risk that sandwiching will be difficult. However, according to the present embodiment, as the sandwiching regions P1 and P2, on the long side LS' of the virtual one-turn region CR', a region having a length of 40% or more including the center thereof can be ensured. Therefore, sandwiching by the coil piece holding portions 111T, 112T, 121T, and 122T becomes easy. As a result, complicated settings and controls for avoiding interference between the first holding portion 11 and the second holding portion 12 and the other long side region LS2 are not required, and the speed of pressure welding can be significantly improved.

[0144] Of course, regarding the formation position of the bent portion B, the width in the X direction of the coil piece holding portions 111T, 112T, 121T, and 122T and the amount of pressure welding (pressing amount) of the coil piece C are taken into consideration.

[0145] Incidentally, as shown in FIG. 10(D), after cold-welding two coil pieces C1 and C2, burrs 55 are generated at the joint portion CP by extrusion. If these burrs 55 remain, there is a risk of interference with the first holding portion 11 and the second holding portion 12 during the next welding. Therefore, in the present embodiment, after completion of cold welding, the coil piece (joint coil piece CC) is taken out from the first holding portion 11 and the second holding portion 12, and the burrs 55 are removed by the removing device 40, and cold welding is performed between the coil piece C (joint coil piece CC) and another (new) coil piece C.

[0146] In each drawing of the present embodiment, for convenience of explanation, the joint portion CP is illustrated, but actually this joint portion is substantially invisible (very difficult) to visually recognize.

[0147] <Removing Device> With reference to FIG. 12, the removing device 40 will be described. FIG. 12 is a schematic view of the removing device 40. FIG. 12(A) is a top view similar to FIGS. 10(A) and 10(C), and FIGS. 12(B) to 12(E) are front views of the removing device 40 similar to FIGS. 10(B) and 10(D) (side views for the joint coil piece CC).

[0148] As shown in FIG. 10(D), the joint coil piece CC immediately after being discharged from the joining device 20 has burrs 55 at the joint portion. The burrs 55 are generated vertically in the up and down direction substantially perpendicular to the wide surface WS of the joint coil piece CC at the joint portion.

[0149] The removing device 40 is a device for removing a part of the joint coil piece CC after cold welding. More specifically, it removes the burrs 55 generated by pressing two coil pieces C.

[0150] Specifically, as shown in FIG. 12, the removing device 40 includes a coil piece holding portion 41 and a removing portion 43. The coil piece holding portion 41 is composed of a first coil piece holding portion 411 and a second coil piece holding portion 412 that are arranged opposite to each other. The first coil piece holding portion 411 and the second coil piece holding portion 412 hold both sides (for example, the short side SS portion) that are separated by a predetermined distance in the belt longitudinal direction with the burr 55 after the joining of the joined coil piece CC interposed therebetween (hold the both sides so as to sandwich both surfaces of the wide surface WS).

[0151] The removing portion 43 is, for example, a cutting means (scissors) configured to be able to advance and retreat in the Z direction with respect to the coil piece C held by the coil piece holding portion 41. Further, the removing portion 43 can also move up and down in the Y direction.

[0152] The coil piece (joined coil piece CC) joined by the joining device 20 is taken out from the joining device 20 by a robot or the like and transferred to the removing device 40 (see FIG. 1). In the removing device 40, when the joined coil piece CC is held by the coil piece holding portion 41, the removing portion 43 that has retreated to the rear in the Z direction (downward in FIG. 12(A)) advances forward in the Z direction (toward the joined coil piece CC) (FIG. (B) of the same figure), and first cuts off the burr 55 protruding upward (FIG. (C) of the same figure). Thereafter, the removing portion 43 once retreats to the rear in the Z direction, moves downward in the Y direction, and then advances forward in the Z direction again (FIG. (D) of the same figure), and cuts off the burr 55 protruding downward (FIG. (E) of the same figure).

[0153] Although not shown, the cutting means of the removing portion 43 is not limited to scissors, and may be, for example, a cutter having saw teeth capable of horizontal movement (horizontal rotation).

[0154] In this way, since the burr 55 is removed by the removing device 40 every time the joining by the joining device 20 is completed, interference between the first holding portion 11 and the second holding portion 12 and the joined coil piece CC can be avoided. That is, the joined coil piece CC can always avoid interference between the first holding portion 11 and the second holding portion 12 and the joined coil piece CC in a state where the burr 55 at the joining portion CP is removed, and can be joined to a new coil piece C.

[0155] Next, with reference to FIG. 13, the coil manufacturing system 100 of the present embodiment and a coil manufacturing method for sequentially connecting a plurality of coil pieces C using the same will be described.

[0156] FIG. 13(A) is a schematic diagram of the coil manufacturing system 100, and FIG. 13(B) is a diagram showing a specific example of the joined coil piece CC formed sequentially with the coil manufacturing system 100.

[0157] As shown in FIG. 13(A), in the present embodiment, one or two bending devices 30, one joining device 20, and one removing device 40 are unitized as a set of coil manufacturing devices 10, and the coil manufacturing units (coil manufacturing devices) 10_1, 10_2, 10_3... corresponding to the number of turns of the coil 50 (the number of regions CR per turn) are prepared, and these are connected continuously in one or a plurality of lines to constitute the coil manufacturing system 100.

[0158] For example, when manufacturing a coil 50 with 5 turns (10 coil pieces C are used) using all U-shaped coil pieces C, the coil manufacturing system 100 is composed of, for example, 9 coil manufacturing units 10_1 to 10_9 connected in series. Then, deformation of the coil piece (formation of the bent portion B0), joining, and deburring are performed every time a unit coil piece C0 is joined to form the joined coil piece CC.

[0159] In this case, for example, 4 and 5 coil manufacturing units 10 may be operated in parallel, and the two joined coil pieces CC manufactured thereby may be finally joined to form a 5-turn coil 50.

[0160] Specifically, it will be described with reference to FIG. 13(B). FIG. 13(B) is a diagram showing the state of the coil piece C (unit coil piece C0 and joined coil piece CC) during manufacturing for each coil manufacturing unit (coil manufacturing device) 10, and the coil piece C is illustrated as a front view (side view of the coil piece C) in the coil manufacturing unit 10. Also, the coil piece C (joined coil piece CC) in the joining device 20 of each coil manufacturing unit 10 shows only the portion of the coil piece C joined in the device.

[0161] Here, as an example, a plurality (here, five (unit coil pieces C01, C02, C03, C04, C05)) of U-shaped (C-shaped) unit coil pieces C0 having two direction conversion parts TN are prepared, and the case of manufacturing a coil (helical structure) 50 (joined coil piece CC) by connecting (continuing) these is shown as an example.

[0162] The first coil manufacturing unit 10_1 is composed of, for example, two bending devices 30_1A and 30_1B, one joining device 20_1, and one removing device 40_1. The second and subsequent coil manufacturing units 10_2... 10_N (10_4 in this example) are each composed of one bending device 30_2... 30_N (30_4), one joining device 20_2... 20_N (20_4), and one removing device 40_2... 40_N (40_4).

[0163] In the coil manufacturing system 100, first, in order to form the first turn region CR1 of the helical structure (the same as the one-turn region of the joined coil piece CC1 (one-joined turn region)), two U-shaped unit coil pieces C01 and C02 are prepared and supplied to the first coil manufacturing unit 10_1. In the first coil manufacturing unit 10_1, the unit coil piece C01 is bent in the bending device 30_1A (Fig. (B)(1) in the same figure), and the unit coil piece C02 is bent in the bending device 30_1B (Fig. (B)(2) in the same figure). Then, the deformed unit coil pieces C01 and C02 are taken out by a robot (not shown) or the like and supplied to the joining device 20_1. In the joining device 20_1, as shown in Fig. 10, the unit coil pieces C01 and C02 are held by the first holding part 11 and the second holding part 12, respectively, and one end face TS1 of the unit coil piece C01 and one end face TS2 of the unit coil piece C02 are connected (cold pressure welding) to form the joined coil piece CC1 (Fig. (B)(3) in the same figure). At this time, the joining device 20_1, for example, presses the end faces TS1 and TS2 against each other in the straight parts of the unit coil piece C01 and the unit coil piece C02, and makes the length of the one-turn region (one-joined turn region) of the joined coil piece CC1 match the length of the one-turn region CR of the coil 50.

[0164] More specifically, in this example, as shown in FIG. 10, the long-side region LS2 of the unit coil piece C01 (coil piece C1) is held by, for example, the first holding portion 11, and the long-side region LS2 of the unit coil piece C02 (coil piece C2) is held by the second holding portion 12, and the TS1 and TS2 of both are pressed against each other. In this example, the long-side region LS2 of the unit coil piece C01 is a long-side region inclined with respect to the reference plane SF0 in which the short side SS and the long-side region LS1 exist, and the long-side region LS2 of the unit coil piece C02 is a long-side region inclined with respect to the reference plane SF0 in which the short side SS and the long-side region LS1 exist. That is, the robot turns the one unit coil piece C0 inside out from the state of being placed on the bending device 30. Specifically, for example, the unit coil piece C01 is turned inside out from the state of being placed on the bending device 30_1A (the state of the posture shown in FIG. 13(B)(1)) so that the pressing surface (the surface against which the pressing portion abuts) in the bending device 30_1A faces downward, and is held by the first holding portion 11 (FIGS. 13(B)(2) and 13(B)(3)). On the other hand, the robot holds the unit coil piece C02 by the second holding portion 12 without turning it inside out from the state of being placed on the bending device 30_1B (keeping the front and back as they are during deformation) (FIGS. 13(B)(1) and (B)(3) of the same figure).

[0165] That is, the long-side region LS2 of the unit coil piece C01 newly joined and the long-side region LS2 of the unit coil piece C02 are horizontally held by the first holding portion 11 and the second holding portion 12, respectively. This step is hereinafter referred to as "performing a leveling step of a new joining region". Then, both are pressed to form a joined coil piece CC1 (FIG. 13(B)(3)).

[0166] Then, the joined coil piece CC1 is taken out again by a robot (not shown) or the like, and burrs 55 are removed in the first removing device 40_1 disposed downstream of the joining device 20_1 (FIG. (B)(4) of the same figure). In the removing device 40_1, when the joined coil piece CC1 is held by the coil piece holding portion 41, the removing portion 43 advances and removes, for example, the burr 55 protruding upward. The removing portion 43 once retreats and descends, and then advances again to remove the burr 55 protruding downward (see FIG. 12).

[0167] Thus, the removing device 40 is configured to be able to advance and retract with respect to the burrs 55 generated by the joining of the unit coil pieces C0, and advances with respect to the burrs 55 for each joining at one location by the joining device 20 to remove the burrs.

[0168] Thereby, a region CR (CR1) corresponding to one turn of the first turn of the spiral structure is formed. Thereafter, the joined coil piece CC1 is taken out by a robot (not shown) or the like and supplied to the joining device 20_2 of the second coil manufacturing unit 10_2 arranged downstream of the first removing device 40_1 (FIG. 13(B)(6)).

[0169] At this time, that is, when supplying to the joining device 20_2 of the second coil manufacturing unit 10_2, one end face TS1 of the joined coil piece CC1 (the end face TS1 where the unit coil piece C02 is not joined) and one end face TS2 of the new unit coil piece C03 are horizontally held by the first holding portion 11 and the second holding portion 12, respectively, and cold pressure welding is performed.

[0170] Then, in the bending device 30_2 of the second coil manufacturing unit 10_2, the bending process of the unit coil piece C03 to be joined next is performed (FIG. (B)(5) in the same figure), and the deformed unit coil piece C03 is taken out by a robot (not shown) or the like. After the second coil manufacturing unit 10_2, since the deformed unit coil pieces C0 are connected to the joined coil pieces CC formed previously one by one, one bending device 30 is provided for one unit.

[0171] In the second joining device 20_2, one end face TS1 of the joined coil piece CC1 (the end face TS1 where the unit coil piece C02 is not joined) and one end face TS2 of the unit coil piece C03 are cold pressure welded in a straight line portion in the same manner as described above to form a joined coil piece CC2 (FIG. (B)(6) in the same figure). Specifically, the long side region LS1 of the joined coil piece CC1 (unit coil piece C02) is held by, for example, the first holding portion 11 (while maintaining the front and back during pressing in the joining device 20_1), and the long side region LS1 of the unit coil piece C03 is held by the second holding portion 12.

[0172] That is, a leveling process (a leveling process for a new joining region) is performed to horizontally hold a new joining region (the long-side region LS1 of the joined coil piece CC1 (unit coil piece C02) and the long-side region LS1 of the new unit coil piece C03) by the first holding portion 11 and the second holding portion 12. In this leveling process, an inclination process (an inclination process for a joined region) is also simultaneously performed, in which the long-side region LS2 of the already joined unit coil piece C01 and the long-side region LS2 of the unit coil piece C02 are inclined from the horizontal state immediately after joining (Fig. (B)(4)). Then, the end faces TS1 and TS2 of both are pressed against each other (Fig. (B)(6)).

[0173] The long-side region LS1 of the joined coil piece CC1 (unit coil piece C02) is a long-side region located in substantially the same plane (reference plane SF0) as the short side SS, and the long-side region LS1 of the unit coil piece C03 is a long-side region located in substantially the same plane (reference plane SF0) as the short side SS.

[0174] Further, for example, the robot performs an inversion process of inverting from the state of being placed on the bending device 30_2 (the state of the posture shown in Fig. 13(B)(1)) so that the pressing surface (the surface against which the pressing portion abuts) in the bending device 30_2 faces downward, and holds the unit coil piece C03 by the second holding portion 12 (Fig. (B)(5), Fig. (B)(6)) to form the joined coil piece CC2.

[0175] Then, the joined coil piece CC2 is taken out by a robot or the like not shown, and burrs 55 are removed in the second removing device 40_2 arranged downstream of the joining device 10_2 (Fig. (B)(7)). Thereby, the joined coil piece CC2 shown in Fig. (B)(7) is obtained. Thereafter, the joined coil piece CC2 is taken out by a robot or the like and supplied to the joining device 20_3 of the third coil manufacturing unit 10_3 (Fig. (B)(9)).

[0176] On the other hand, in the bending device 30_3 of the third coil manufacturing unit 10_3, the unit coil piece C04 to be joined next is bent (Fig. (B)(8)), and the deformed unit coil piece C04 is taken out by a robot or the like not shown.

[0177] In the third bonding device 20_3, one end face TS1 of the bonding coil piece CC2 (the unbonded end face of the unit coil piece C03) and one end face TS2 of the unit coil piece C04 are cold pressure-bonded in a straight line portion in the same manner as above to form a bonding coil piece CC3 (Fig. (B)(9) in the same figure). Specifically, the long side region LS2 of the bonding coil piece CC2 (unit coil piece C03) is held, for example, by the first holding portion 11 (while maintaining the front and back during pressing in the bonding device 20_2), and the long side region LS2 of the unit coil piece C04 is held by the second holding portion 12. That is, a leveling step (a leveling step for a new bonding region, an inclination step for a bonded region (the long side region LS1 of the unit coil piece C02 and the long side region LS1 of the unit coil piece C03)) for horizontally holding a new bonding region (the long side region LS2 of the bonding coil piece CC2 (unit coil piece C03) and the long side region LS2 of the new unit coil piece C04) by the first holding portion 11 and the second holding portion 12 is performed, and the end faces TS1 and TS2 of both are pressed. The long side region LS2 of the bonding coil piece CC2 (unit coil piece C03) is a long side region inclined with respect to the reference plane SF0, and the long side region LS2 of the unit coil piece C04 is also a long side region inclined with respect to the reference plane SF0.

[0178] Further, for example, the robot holds the unit coil piece C04 by the second holding portion 12 in a state of being placed on the bending device 30_3 (without inverting the front and back) so that the pressing surface (the surface where the pressing portion abuts) in the bending device 30_3 faces upward, and forms the bonding coil piece CC3.

[0179] Then, the bonding coil piece CC3 is taken out by a robot or the like (not shown), and burrs 55 are removed in the third removing device 40_3 arranged downstream of the bonding device 10_3 (Fig. (B)(10) in the same figure). Thereby, a region CR (CR2) corresponding to one turn of the second turn of the spiral structure is formed. Thereafter, the bonding coil piece CC3 is taken out by a robot or the like and supplied to the bonding device 20_4 of the fourth coil manufacturing unit 10_4 (Fig. (B)(12) in the same figure).

[0180] On the other hand, in the bending device 30_4 of the fourth coil manufacturing unit 10_4, the bending process of the unit coil piece C05 to be joined next is performed (Fig. (B)(11)), and the deformed unit coil piece C05 is taken out by a robot (not shown).

[0181] In the fourth joining device 20_4, one end face TS1 of the joined coil piece CC3 (the end face where the unit coil piece C04 is not joined) and one end face TS2 of the unit coil piece C05 are cold pressure welded in a straight line portion in the same manner as above to form a joined coil piece CC4 (Fig. (B)(12)). Specifically, the long side region LS1 of the joined coil piece CC3 (unit coil piece C04) is held by, for example, the first holding portion 11 (while maintaining the front and back during pressing in the joining device 20_3), and the long side region LS1 of the unit coil piece C05 is held by the second holding portion 12. A leveling process (a leveling process for the new joined region, an inclination process for the joined region (the long side region LS2 of the unit coil piece C03 and the long side region LS2 of the unit coil piece C04)) is performed to horizontally hold the new joined region (the long side region LS1 of the joined coil piece CC3 (unit coil piece C04) and the long side region LS1 of the new unit coil piece C05) by the first holding portion 11 and the second holding portion 12, and then the end faces TS1 and TS2 of both are pressed. The long side region LS1 of the unit coil piece C05 is the long side region located on the reference plane SF0, and the long side region LS1 of the joined coil piece CC3 (unit coil piece C04) is also the long side region located on the reference plane SF0.

[0182] Also, for example, the robot performs an inversion process of inverting the surface and the back from the state of being placed on the bending device 30_4 so that the pressing surface (the surface where the pressing portion abuts) in the bending device 30_4 faces downward, holds the unit coil piece C05 by the second holding portion 12 (Fig. (B)(11), Fig. (B)12)), and forms the joined coil piece CC4.

[0183] Then, the joined coil piece CC4 is taken out by a robot (not shown) or the like, and burrs 55 are removed in the fourth removing device 40_4 disposed downstream of the joining device 10_4 (FIG. (B)(13)). Thereby, the joined coil piece CC4 shown in FIG. (B)(13) is obtained. Thereafter, the joined coil piece CC4 is taken out by a robot or the like. Thereafter, if necessary, this is repeated a predetermined number of turns N, whereby a spiral structure having a region CR for one turn of N turns is formed.

[0184] As described above, in the present embodiment, the bent coil pieces C1 and C2 are joined at the end faces TS1 and TS2. Specifically, the joining of the coil piece C1 and the coil piece C2 is performed by joining one side having the bent portion B0 of the coil piece C1 (for example, the long side region LS2) and one side having the bent portion B0 of the coil piece C2 (for example, the long side region LS2) (for example, FIGS. (B)(1) to (B)(3)), or by joining one side not having the bent portion B0 of the coil piece C1 (for example, the long side region LS1) and one side not having the bent portion B0 of the coil piece C2 (for example, the long side region LS1) (for example, FIGS. (B)(5) and (B)(6)).

[0185] Then, as described above, the bending step of the coil piece C by the bending device 30 (FIG. (B)(1)) is performed, the inversion step of one coil piece C is performed (FIG. (B)(2)), the leveling step of the new joining region (the inclination step of the joined region) is performed (FIGS. (B)(1) to (B)(3)), the joining step by the joining device 20 is performed (FIG. (B)(3)), and the removing step by the removing device 40 is performed (FIG. (B)(4)).

[0186] Thereafter, the bending step of the coil piece C by the bending device 30 is performed, the inversion step of one coil piece C is performed (FIG. (B)(5)), the leveling step of the new joining region is performed, the joining step by the joining device 20 is performed (FIG. (B)(6)), and the removing step by the removing device 40 is performed (FIG. (B)(7)).

[0187] Subsequently, the bending process of the coil piece C by the bending device 30 is performed (Fig. (B)(8)), the leveling process of the new joint area is performed, the joining process by the joining device 20 is performed (Fig. (B)(9)), and the removal process by the removal device 40 is performed (Fig. (B)(10)).

[0188] Thereafter, the bending process of the coil piece C by the bending device 30 is performed, the inversion process of one coil piece C is performed (Fig. (B)(11)), the leveling process of the new joint area is performed, the joining process by the joining device 20 is performed (Fig. (B)(12)), and the removal process by the removal device 40 is performed (Fig. (B)(13)).

[0189] By repeating this, a spiral structure is obtained in which one of the long sides LS of the opposing long sides LS of the one-turn region CR is inclined with respect to the other long side LS as shown in Fig. (B)(10) and Fig. (B)(13).

[0190] That is, in the coil manufacturing apparatus 10 of the present embodiment, the coil pieces are connected (added) in a state of spreading in the advancing direction of the spiral. After the spiral structure is completed, the spiral structure is integrally molded (for example, by pressing, etc.), and elastic deformation and / or plastic deformation that compresses in the advancing direction of the spiral is performed to form the coil 50 in which each turn of the spiral is close to each other.

[0191] In this example, the coil piece C to be newly connected is described as an example in which the bent portion B0 by the bending device 30 is formed and supplied to the joining device 20 (each time it is connected, immediately before the connection). However, the present invention is not limited to this, and the bending process of the coil piece C by the bending device 30 may be performed in advance for all the required coil pieces C. That is, for example, when forming the coil 50 using 20 coil pieces C as the total number, after forming the bent portion B0 for all 20 coil pieces C by the bending device 30, they may be supplied to the joining device 20 one by one.

[0192] Even in this case, every time a joint portion CP is formed, the removing device 40 removes the burr 55 of the joint portion CP. With such a configuration, the joined coil piece CC can always avoid interference between the first holding portion 11 and the second holding portion 12 and the joined coil piece CC with the burr 55 of the joint portion CP removed, and can be joined to the new coil piece C.

[0193] FIG. 14 is a view showing an example of the completed spiral structure 50' discharged from the predetermined number (the Nth) of coil manufacturing units 10_N (the number of turns of the coil is different from that in the above-described embodiment). FIG. 14(A) is a front view (top view) seen from the spiral axis direction, FIG. 14(B) is a view in the direction of arrow V1 before forming in FIG. 14(A) (side view), and FIGS. 14(C) to 14(E) are views in the direction of arrow V2 after forming (side view).

[0194] The completed spiral structure 50' is formed into a desired shape. That is, the coil piece C of the present embodiment is bent by the bending device 30 before cold pressure welding, and a gap G is formed between the regions CR for each turn as shown in FIG. 14(B) immediately after being discharged from the coil manufacturing device 10.

[0195] Therefore, forming is performed to narrow the gap G. Specifically, first, annealing is performed to soften the spiral structure 50'. That is, the spiral structure 50' made of a metal material (for example, a copper plate) is heated to an appropriate temperature (for example, a temperature equal to or higher than the recrystallization temperature) in a furnace, held for a predetermined time, and slowly cooled in the furnace. As a result, the metal material constituting the spiral structure 50' becomes a structure without internal stress and softens. That is, the spiral structure 50' is made in a state where it is easily plastically deformed by annealing. Alternatively, it can be said that the plastic coefficient of the spiral structure 50' is controlled by annealing (the elastic limit of the spiral structure 50' is lowered). After annealing, although the spiral structure 50' (the metal material thereof) softens, when no external force is applied to the spiral structure 50', its shape (the gap G shown in FIG. 14(B)) is maintained.

[0196] Then, the spiral structure 50' having the shape shown in FIG. (B) is immersed in a liquid insulating resin and integrally coated with the insulating resin. Note that the spiral structure 50' may be integrally coated with the insulating resin by spraying the liquid insulating resin thereon. As a result, the insulating resin also enters the gap G between the regions CR for each turn, and a spiral structure 50' is obtained in which the periphery of the flat conductor is covered with the insulating resin from one end to the other end along the spiral advancing direction.

[0197] Thereafter, as shown in FIG. (C), the spiral structure 50' is compressed in the spiral axis direction so that the gap G of the spiral structure becomes smaller, and elastically deformed and / or plastically deformed in the spiral advancing direction of the spiral structure, and each turn of the spiral is brought close to each other and solidified. The annealed spiral structure 50' is easily elastically deformed and / or plastically deformed, the gap G between the regions CR for each turn disappears, and the regions CR for each turn are fixed (solidified) in a state of being in close contact with each other. Alternatively, it is fixed (solidified) in a state where the gap G between the regions CR for each turn becomes extremely small. Then, each of the closely or proximately arranged regions CR for each turn is insulated (FIG. (C) or FIG. (D)).

[0198] Furthermore, for example, in the case of the coil 50 attached to the stator core, if necessary, in accordance with the shape of the stator core, it is formed into a concave or convex shape in the axial center direction of the spiral structure (the radial direction of the stator core), that is, a curved shape in which the inner peripheral end portion is not on the same plane as the outer peripheral end portion, as shown in FIG. 14(E). Thereby, a coil 50 integrally covered with the insulating resin is obtained.

[0199] Conventionally, a long conductor of a length corresponding to the completed length of the coil was coated with an insulating resin and then wound to form a spiral structure. However, in this case, near the outer periphery of the curved portion of the winding, the insulating resin was stretched and the coating thickness became thin, which was a factor causing breakdown voltage deterioration. Also, for example, even when coating with an insulating resin before the above molding, the same problem occurs because the coating thickness of the insulating resin varies due to pressing. In this embodiment, the spiral structure 50' is annealed and softened with a gap G between regions CR for each one turn, integrally coated with an insulating resin, and then compression molded to eliminate (make extremely small) the gap G and solidify. That is, the flat conductor can be coated with the insulating resin substantially uniformly around its circumference along the spiral advancing direction from one end to the other end of the spiral structure 50', and the uniformity of the film thickness of the insulating resin can be enhanced. Also, it becomes possible to bond the regions CR for each one turn of the spiral structure 50' with the insulating resin.

[0200] The joining device 20 of this embodiment manufactures the coil 50 by adding coil pieces C while repeating compression (shrinkage) by cold compression using coil pieces C that are longer (with a margin length) by the amount of compression (shrinkage) by cold compression based on the length of the coil 50 after completion.

[0201] Therefore, during cold pressure welding, cold pressure welding is performed while measuring the distance in the strip longitudinal direction BL (see Fig. 2(B)) of the coil piece C. The measurement of the distance in the strip longitudinal direction BL can be performed, for example, by providing a slip detection mechanism (not shown) in the first holding portion 11 and the second holding portion 12 (or in the vicinity thereof), and detecting the slip during the pressing of the coil piece C (first coil piece C1) held by the first holding portion 11 and the coil piece C (second coil piece C2) held by the second holding portion 12, thereby measuring the distance in the strip longitudinal direction BL. Note that the measurement of the distance in the strip longitudinal direction BL may be performed simultaneously (in real time) with cold pressure welding, or may be measured before and after (or before or after) cold pressure welding. Thereby, high-precision of the coil dimensions after completion can be achieved.

[0202] As shown in FIGS. 2(A), 2(E) to 2(G), the substantially right-angle direction conversion portion TN of the coil piece C becomes the corner portion of the coil 50. That is, according to the joining device 20 of the present embodiment, by joining the coil pieces C configured to have the substantially right-angle direction conversion portion TN by punching or the like, the coil 50 with substantially right-angle corner portions on the inner peripheral side and the outer peripheral side can be manufactured. Conventionally, a long flat conductor was wound to manufacture a coil made of the flat conductor, but in winding, it was inevitable that at least the corner portion on the inner peripheral side of the coil had a curved shape, and there were limitations in improving the occupancy rate and heat dissipation.

[0203] However, according to the coil manufacturing apparatus 10 of the present embodiment, since the coil pieces can be joined as they are in the shape formed by punching, a right-angle (substantially right-angle) corner portion can be realized even on the inner peripheral side of the coil, the occupancy rate can be improved, and the coil 50 that can improve the heat dissipation by eliminating the extra space can be manufactured.

[0204] In particular, the joint portion CP between the coil pieces C is provided in a straight portion avoiding the direction conversion portion TN (corner portion). That is, pressure welding is performed using the straight portion of the coil piece. As a result, the shape accuracy of the direction conversion portion TN can be improved, and for example, the corner portion formed at a right angle (substantially right angle) in the punching process can be maintained.

[0205] Furthermore, according to the present embodiment, high-quality coils with improved occupancy rate and thereby improved heat dissipation can be mass-produced, and productivity can be improved.

[0206] <Coil Manufacturing Method> Next, the coil manufacturing method of the present embodiment will be described. The coil manufacturing method of the present embodiment can be implemented, for example, in the above-described coil manufacturing apparatus 10.

[0207] That is, the coil manufacturing method of the present embodiment is a coil manufacturing method for forming a spiral structure by joining a plurality of flat conductors (coil pieces C), and includes a bending step of bending each flat conductor C so that a part along the spiral advancing direction is inclined with respect to the other part, and a joining step of pressing the end faces of the bent flat conductor C and another flat conductor C along the strip longitudinal direction, shortening the distance in the strip longitudinal direction while pressing and joining them to form a spiral structure, and a removing step of removing a part of the joined flat conductor.

[0208] Here, the bending step can be carried out by the above-described bending device 30. For each of the coil pieces C, one of the two opposing sides (for example, the long side regions LS1 and LS2 that constitute the long side LS) that are planned to constitute the one-turn region CR (for example, the long side region LS2) is bent so as to be inclined with respect to the other (for example, the long side region LS1).

[0209] Then, a flattening step of the new joining region is performed, and in the joining step, the end faces of the coil pieces C are pressed against each other by the joining device 20.

[0210] Also, the removing step can be carried out by the above-described removing device 40, and removes the burrs 55 generated by pressing the plurality of flat conductors C.

[0211] Since the detailed methods of these bending step and removing step are as described above, the description here is omitted. Hereinafter, mainly the method of pressure welding in the joining device 20 will be described. Note that, although it is repetitive, the manufacturing method of the coil of the present embodiment performs bending processing on each coil piece C (it may be configured to perform bending processing one by one immediately before joining, or may be configured to perform bending processing on the entire required number of coil pieces C), presses (joins) another coil piece C (C02) in which a bent portion B0 is formed to a certain coil piece C (C01) in which the bent portion B0 is formed, and removes the burrs 55 generated at the joint portion CP every time such pressure welding is performed (see FIG. 13).

[0212] However, in the following description, mainly for the purpose of explaining the welding method in detail, the bending process and the removal process (deburring process) performed before and after welding are omitted or simplified in the description.

[0213] First, referring to FIG. 15, an outline of the welding of the coil piece C will be described. This figure is a top view of the coil piece C. Each of the plurality of coil pieces C used in this embodiment can form a virtual spiral structure (hereinafter referred to as "virtual spiral structure") by bringing the end faces TS1 and TS2 into contact with each other. Specifically, (a flattening process is performed on the new joint region), as shown in FIG. (A) of the same figure, the end faces TS1 and TS2 in the strip longitudinal direction of the unit coil piece C01 and the unit coil piece C02 are brought into contact with each other, and a region corresponding to one turn (virtual one-turn region) CR' of the virtual spiral structure 50V shown in FIG. (B) of the same figure is set to be formable. And the virtual spiral structure 50V is set such that the length of the virtual one-turn region CR' in the spiral advancing direction is longer than the length of the one-turn region CR (FIG. (C) of the same figure) of the completed spiral structure (coil) 50 by the pressing amount of welding.

[0214] The joining device 20 presses the unit coil piece C01 and the unit coil piece C02 in the strip longitudinal direction to form the joined coil piece CC shown in FIG. (C) of the same figure, and makes the length of the joined one-turn region CR0 of the joined coil piece CC coincide with the length of the one-turn region CR of the spiral structure (coil) 50. Note that the end faces TS0 and TS1' on the side opposite to the end faces TS1 and TS2 in FIG. (A) are not welded to each other, but are welded to the end faces of other coil pieces C (or connected to terminals led out to the outside).

[0215] That is, in the coil manufacturing method of the present embodiment, a plurality of strip-shaped flat conductors (coil pieces C) that can form a spiral structure 50 when connected and have a folded portion B are prepared. The preparation length L0, which is the total distance in the strip longitudinal direction of the plurality of coil pieces C, is set to be longer by a margin M compared to the completed length L in the spiral longitudinal direction of the spiral structure (coil) 50 to be completed. The end faces of the plurality of coil pieces C are pressed along the strip longitudinal direction, and cold welding is performed while shortening the distance in the strip longitudinal direction. Burr removal of the joint portion CP is performed every time the joint portion CP is formed. By setting the total shortening distance S for shortening all of the plurality of coil pieces C by cold welding to the margin M, the plurality of coil pieces C are joined together to form a spiral structure (coil) 50.

[0216] Specifically, with reference to FIG. 16, an example of manufacturing a coil (spiral structure) 50 having a two-turn spiral shape by preparing four (C01 to C04) U-shaped (channel-shaped) unit coil pieces C0 each having two direction conversion portions TN and connecting (continuing) them will be described. FIG. 16(A) is a top view of the unit coil pieces C01 to C04, and FIGS. 16(B) to 16(D) are development views of the joined coil pieces CC. The broken lines in the figure indicate the axial center (center of the joint portion CP) of the spiral structure of the coil 50 to be completed. Also, the two-dot chain lines at both ends of the coil pieces in FIGS. 16(B) to 16(D) indicate the finished end portions of the completed coil. In this example, it is assumed that the finished end portions do not change (the position of the finished end portions does not move in the left-right direction shown in the figure) for the description.

[0217] Assuming that the lengths of the unit coil pieces C01 to C04 in the longitudinal direction of the strip are L01 to L04 respectively, the preparation length L0, which is the total distance in the longitudinal direction of the strip, is L01 + L02 + L03 + L04. And this preparation length L0 is set to be longer than the completed length L of the coil 50 in the helical longitudinal direction by a margin M (L0 = L + M). When the unit coil piece C01 and the unit coil piece C02 are pressed and cold-welded along the longitudinal direction of the strip, due to these presses, the length L01 of the unit coil piece C01 is compressed to L01' in the longitudinal direction of the strip (the amount of shortening (compression) is the length of the distance S1 from the center of the joint CP (compression amount S1)), and the length L02 of the unit coil piece C02 is compressed to L2' in the longitudinal direction of the strip ((the amount of shortening (compression) is the length of the distance S2 from the center of the joint CP (compression amount S2)), and the joint coil piece CC1 (length LC1) is formed (Fig. (B) of the same figure). Then, when the end face of the joint coil piece CC1 (the end face on the side where the unit coil pieces C01 or C02 are not joined) and the unit coil piece C03 are cold-welded, due to these presses, the unit coil piece C03 is compressed to L03' (the amount of shortening (compression) is the length of the distance S3 from the center of the joint CP (compression amount S3)), and the joint coil piece CC1 is compressed to LC1' ((the amount of shortening (compression) is the length of the distance S4 from the center of the joint CP (compression amount S4)), and the joint coil piece CC2 is formed (Fig. (C) of the same figure). Further, when the end face of the joint coil piece CC2 (the end face on the side where the unit coil pieces C01, C02, and C03 are not joined) and the unit coil piece C04 are cold-welded, due to these presses, the unit coil piece C04 is compressed to L04' (the amount of shortening (compression) is the length of the distance S5 from the center of the joint CP (compression amount S5)), and the joint coil piece CC2 is compressed to LC2' ((the amount of shortening (compression) is the length of the distance S6 from the center of the joint CP (compression amount S6)), and the coil 50 (helical structure) with the completed length L in the helical longitudinal direction (the length from the starting point ST to the ending point ET) is completed (Fig. (D) of the same figure). The total amount of shortening of the coil pieces (the total shortening distance S = S1 + S2 + S3 + S4 + S5 + S6) until the coil 50 is completed by joining the coil pieces (unit coil pieces and / or joint coil pieces) corresponds to the margin M.

[0218] The manufacturing method of the coil according to this embodiment will be described again along the time series. First, based on the length L of the completed coil 50, the lengths L01 to L04 of the unit coil pieces are set so that the shortening total distance S = the margin M, and the compression amounts S1 to S6 by cold welding are set.

[0219] Then, using the coil pieces thus set (each having a bent portion B0 not shown), the end faces of the unit coil piece C01 and the unit coil piece C02 are pressed together by the set compression amounts S1 and S2 and added by cold welding to form a joined coil piece CC1. At this time, the compression amounts S1 and S2 are grasped by measuring the distance in the longitudinal direction of the strip of both coil pieces by detecting the slip when pressing the unit coil piece C01 and the unit coil piece C02. The method of grasping the compression amount is the same in the following cold welding.

[0220] After cold welding one joining region (for example, near the end face where the unit coil piece C01 and the unit coil piece C02 are joined), burrs are generated by pushing into the joint, so after cold welding, a process of cutting off the burrs is performed.

[0221] Next, while elastically deforming and / or plastically deforming the coil piece (joined coil piece CC1) in the spiral advancing direction of the spiral structure to be completed, leaving the vicinity of the end face to be cold welded (the end face of the unit coil piece C01 or the unit coil piece C02 that is not joined), cold welding is performed with another coil piece (unit coil piece C03). At this time, the amount of elastic deformation and / or plastic deformation in the spiral advancing direction of the joined coil piece CC1 is set to an amount that avoids interference between the first holding portion 11 and the second holding portion 12 that hold the coil piece during cold welding and the joined coil piece CC1. Also, the amount of deformation is the same in the following cold welding.

[0222] Next, coil pieces are added in the same manner. That is, the end face of the joined coil piece CC1 (the end face on the side where the unit coil pieces C01 or C02 are not joined) and the unit coil piece C03 are pressed by the set compression amounts S3 and S4 and added by cold welding to form the joined coil piece CC2. Thereafter, burrs in the joined area are removed, and while elastically deforming and / or plastically deforming the joined coil piece CC2 in the spiral progression direction of the spiral structure to be completed, leaving the vicinity of the end face to be cold welded, the end face of the joined coil piece CC2 and the unit coil piece C04 are pressed by the set compression amounts S5 and S6 and added by cold welding to obtain the spiral structure in the completed state.

[0223] <Deformation Example of Coil Piece> FIG. 17 is a diagram showing a connection example when the shapes of the coil pieces are different.

[0224] FIG. (A) thereof is a top view showing a connection example using L-shaped coil pieces, and here shows a case where a joined coil piece for one turn is configured using four L-shaped unit coil pieces C0. For convenience of explanation, the illustration is omitted, but also in this case, the preparation length L0, which is the total distance in the strip longitudinal direction of each coil piece, is set to be longer by a margin M compared to the completed length L in the spiral longitudinal direction of the spiral structure (coil) to be completed. And the margin M is set to the total shortening distance S that is shortened by pressing when all of the plurality of coil pieces are cold welded.

[0225] Note that it is not necessary to configure all of the coil connection pieces for one turn in the same shape (L-shaped). That is, an I-shaped (linear) or U-shaped (C-shaped) coil piece may be combined with the L-shaped one to form the coil connection piece for one turn.

[0226] Figure (B) is a top view showing a connection example in which a C-shaped unit coil piece C0 and an I-shaped unit coil piece C01 are combined. For convenience of explanation, although illustration is omitted, also in this case, the preparation length L0, which is the total distance in the strip longitudinal direction, of each coil piece is set to be longer by a margin M compared to the completed length L in the spiral longitudinal direction of the spiral structure (coil) planned to be completed. And the margin M is set to the total shortening distance S that is shortened by pressing when all of the plurality of coil pieces are cold-welded.

[0227] Also, the direction conversion part TN may be a coil connection piece for one turn by combining three substantially C-shaped unit coil pieces and one L-shaped unit coil piece of the direction conversion part TN. Further, the unit coil pieces constituting the first turn and the second turn of the spiral structure may be different combinations respectively.

[0228] Figure (C) is a developed view in the case of forming a joined coil piece by combining two U-shaped (C-shaped) unit coil pieces C0 units of the direction conversion part TN and a coil piece (O-shaped (square-shaped) coil piece) C1 for one turn of the spiral structure planned to be completed. The two-dot chain lines at both ends of the coil piece in the figure indicate the finished ends of the completed coil. In this example, it is described assuming that the finished ends do not change (the position of the finished ends does not move in the left-right direction shown in the figure).

[0229] The joining part of the O-shaped coil piece C1 is cut. When one end of the U-shaped unit coil piece C0 unit and one end of the O-shaped coil piece C1 are cold-welded, the U-shaped unit coil piece C0 unit is compressed by a compression amount S0, and the O-shaped coil piece C1 is compressed by a compression amount S1, and by repeating this, a spiral structure can be formed. In FIG. 16, (when using U-shaped unit coil pieces C0 units of the same length), as shown in the figure, the joint CP is formed at substantially the same position (superimposed position) along the axis center of the spiral structure in each turn of the spiral structure. However, in the case of FIG. 17(C), the joint CP is formed at a position shifted by a predetermined amount along the axis center (broken line) of the spiral structure in each turn of the spiral structure.

[0230] <Modification example of the coil> FIG. 18 is a diagram showing a modified example of the coil 50, where FIG. 18(A) is a side view corresponding to FIG. 14(C), and FIG. 18(B) is a perspective view of the coil 50.

[0231] The coil piece C of this embodiment may be such that the widths WA, WB, WC, WD, WE... in the belt short-side direction of the coil piece C are different (sequentially increasing (or decreasing)) along the spiral progression direction. In this case, the thicknesses D1 to D5 (the thickness in the axial direction of the spiral) of the coil piece C are made different according to the widths WA to WE so that the cross-sectional areas at any positions in the spiral progression direction (for example, the cross-sectional areas SC1 and SC2 shown by the hatching in FIG. 18(A)) are equal to each other. As shown in this figure, this coil 50 has the outer shape of a frustum of a square pyramid.

[0232] <Method of attaching to the stator core> Referring to FIG. 19, an example of attaching the coil 50 of this embodiment to the stator core will be described. FIG. 19(A) is a side view of the coil 50 and the cassettes 51A, 51B when the axial direction of the spiral of the coil 50 is the left-right direction shown in the figure. FIG. 19(B) is a top view of FIG. 19(A). FIG. 19(C) is a top view showing another example of attachment to the stator core 60.

[0233] Spiral axis The coil 50 of this embodiment is formed along the outer shape of the stator core as shown in FIG. 14(E), and after forming, it is integrally coated with an insulating resin, and this is attached to the stator core 60 by so-called after-attachment.

[0234] Therefore, for example, as shown in FIG. 19(A), the coil 50 is sandwiched between a pair of cassettes 51A and 51B, and the cassettes 51A and 51B are attached to the stator core 60. Specifically, the cassette 51A has a support portion 53A inserted into the inner peripheral side of the spiral structure of the coil 50 to support the coil 50, and a flange portion 52A provided on one surface side in the axial center direction. Similarly, the cassette 51B has a support portion 53B and a flange portion 52B.

[0235] In this case, the support portion 53A is inserted into the inner circumference of the coil 50 from the side where the flange portion 52A of one cassette 51A is not formed, and the other cassette 51B is overlaid, and the two are engaged with an engaging portion (not shown) provided on the support portions 53A and 53B. Then, the coil 50 with the cassette is attached to the stator core 60 as shown in FIG. (B) of the same figure. Although not shown, the stator core 60 has a fixing portion for the coil 50 with the cassette, and the coil 50 with the cassette is fixed by fitting (engaging) with the fixing portion.

[0236] Alternatively, as shown in FIG. (C) of the same figure, the coil 50 may be attached to one cassette 51C having a flange portion 52C only on one surface side in the axial center direction of the spiral structure and then mounted on the stator core 60. In that case, in order to prevent the coil 50 from coming off the stator core 60 (or unnecessary movement (vibration) occurring) due to centrifugal force during operation, a notch 61 is provided in the stator core 60, and after the coil 50 with the cassette is attached to the stator core 60, a retaining ring 62 covering the upper part of the coil 50 with the cassette may be fitted with the notch 61 of the stator core 60.

[0237] In this way, the coil 50 is attached to the stator core 60 to form a stator (not shown), and a known rotor is assembled so as to be rotatable with respect to the stator, and a motor (not shown) is manufactured.

[0238] In the above-described embodiment, the case where the coil piece C is U-shaped has been described as an example. However, in this embodiment, various modifications are possible as long as the shape of the coil 50 (spiral structure) shown in FIG. 14 can be obtained. For example, when the shape of the coil piece C is another shape (FIGS. 2(B), (D), (F), (G), (H)), the configuration of the bending device 30 and the deformation position thereby, the configuration of the joining device 20 and the joining position thereby, and the configuration of the removing device 40 and the removing position thereby are appropriately changed so that the shape of the coil 50 (spiral structure) shown in FIG. 14 can be obtained.

[0239] In addition, the coil manufacturing apparatus 10 of the present embodiment has been described by taking as an example the case where it includes a bending device 30, a joining device 20, and a removing device 40. However, the coil manufacturing apparatus 10 according to the present invention may have a configuration including a bending device 30 and a joining device 20, or the coil manufacturing apparatus 10 may have a configuration including a joining device 20 and a removing device 40.

[0240] Further, in the coil manufacturing apparatus 10 (see FIG. 1), the bending device 30, the joining device 20, and the removing device 40 may be housed in a single housing, or the bending device 30 and the joining device 20 may be housed in a single housing, or the joining device 20 and the removing device 40 may be housed in a single housing.

[0241] Further, in the coil manufacturing system 100 (see FIG. 13), a plurality of coil manufacturing units 10_N may be housed in a single housing.

[0242] Further, the configuration is not limited to deforming each coil piece C before joining one by one. Instead, after all the predetermined number (required number) of coil pieces C that form the coil 50 are deformed in advance by the bending device 30, the deformed coil pieces C may be joined by the joining device 20.

[0243] As described above, the present invention is not limited to the above-described embodiments and can be configured in various embodiments. For example, the direction conversion portion TN of the coil piece may be curved.

[0244] In addition, one coil piece is not limited to being formed by punching a single copper plate. Instead, it may be formed by arranging a plurality of flat conductors (for example, flat conductors having a square cross-sectional shape in the longitudinal direction of the strip) in parallel in the short side direction of the coil strip. Further, a part of the coil may be formed by a coil piece formed by punching a single copper plate, and a part thereof may be formed by a coil piece formed by arranging flat conductors in parallel.

Industrial Applicability

[0245] The present invention can be used when manufacturing coils (flat coils, edgewise coils) using flat conductors, etc.

Explanation of Signs

[0246] 10 Coil manufacturing apparatus (coil manufacturing unit) 11 First holding part 12 Second holding part 13 Driving part 14 Control part 15 Biasing member 16 Fixing member 17 Movement restricting part 18 Pressing part 20 Joining device 30 Bending device 31 Feeding part 33 Conveying part 35 Supporting part 37 Deforming part 40 Removing device 41 Coil piece holding part 43 Removing part 50 Coil (helical structure) 50V Virtual helical structure 51A, 51B, 51C Cassette 52A, 52B, 52C Flange part 53A, 53B Supporting part 55 Burr 60 Stator core 100 Coil manufacturing system 111 First upper holding body 112 First lower holding body 121 Second upper holding body 122 Second lower holding body 111T, 112T, 121T, 122T Coil piece holding part 161 Protrusion 162 Protrusion 163A Restricting surface 311 Turntable 331 Rail member 333 Driving part 351 Supporting table Pressing part 353 371 Holding part 373 Biasing part 373S Inclined surface 411 Coil piece holding part 412 Coil piece holding part C Coil piece (flat conductor) CC Joined coil piece CP Joint part CR One-round area TN Direction conversion part TS End face

Claims

1. A step of continuously forming a spiral structure in which a region for one turn around the axis (hereinafter referred to as “one-turn region”) is stacked in a plurality of layers in the extending direction of the axis so that a gap is formed between the one-turn regions; A step of annealing the spiral structure in a state where the gap is formed; A step of insulating each of the one-turn regions after annealing the spiral structure; A step of compressing the spiral structure along the extending direction of the axis after insulating each of the one-turn regions, and A coil manufacturing method characterized by the above.

2. Each of the one-turn regions is deformed to form the spiral structure, The coil manufacturing method according to claim 1, characterized by the above.

3. After compressing the spiral structure along the extending direction of the axis, the spiral structure is deformed, The coil manufacturing method according to claim 1, characterized by the above.

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