Coil joint body

Abstract

To provide a coil joint body and a manufacturing method thereof that can simplify a configuration of a connection part between a coil and wiring members (bus bar), simplify the number of parts and a connection process, suppress increase in resistance at the connection part, and keep a good connection state as well.SOLUTION: A coil with bus bar 10 includes a coil 11 made of a wound first metal member 13 and a bus bar 12 made of a second metal member 14 connected to an end part 11E of the coil 11. A joint part 16 between the end part 11E of the coil and the bus bar 12 is formed by a pressure welding joint where the end faces are butted together.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a coil assembly. [Background technology]

[0002] Conventionally, when manufacturing a stator (fixed part) that constitutes a motor, in general, wound coils are sequentially mounted in multiple slots (teeth) provided on the inner peripheral surface of an annular stator core, or a coil member (e.g., copper wire, etc.) is sequentially wound around each slot to arrange multiple coils in an annular shape. In this case, the annularly arranged coil is configured so that both ends (start end and end end) of the winding protrude to one side in the axial direction of the stator core (e.g., upward), and the both ends are connected directly or via connecting members to wiring members such as rod-shaped (arc-shaped) or annular bus bars that extend in the circumferential direction of the stator core by welding or screwing (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5904698 [Patent Document 2] Patent No. 4661849 Summary of the Invention [Problem to be solved by the invention]

[0004] However, connection methods using welding and screws have limitations on miniaturizing the completed stator because the joint structure is complicated. Also, a device is required to connect the wiring member (bus bar) and the coil after the coil is attached to the stator core, which increases the size of the stator manufacturing equipment and makes the connection work complicated.

[0005] Furthermore, when connecting the coil terminals and wiring members (bus bars) with screws or via connecting members, an increase in resistance at the joint is unavoidable compared to direct metal-to-metal joining. In recent years, advances in coil development have made it possible to reduce the resistance of the coil itself, but if the resistance at the joints increases, there is no point in using a low-resistance coil.

[0006] Furthermore, there are problems such as an increase in the number of parts and a complicated connection process (increased man-hours).

[0007] In view of the above circumstances, the present invention aims to provide a coil connection body and a manufacturing method thereof that can simplify the configuration of the connection portion between a coil and a wiring member (bus bar), simplify the number of parts and the connection process, suppress an increase in resistance at the connection portion, and ensure a good connection state. [Means for solving the problem]

[0008] The present invention provides a coil joined body including a coil made of a wound first metallic member and a busbar made of a second metallic member connected to an end of the coil at the start and / or end of the winding, the coil being wound while being bent in one direction, the end being led out on an extension of a long side of a winding region of the coil without changing the direction of bending, the coil joined body having a joint where end faces of the coil and the busbar are butted together, a post-joining coil straight portion, and a joined body straight portion including a post-joining busbar straight portion, the post-joining coil straight portion being a straight region continuing from the joint, and the post-joining busbar straight portion being a straight region continuing from the joint, and the length of the joined body straight portion is shorter than the abutting length of the coil straight portion of the coil before being pressed and the busbar straight portion of the busbar before being pressed.

[0009] The present invention also provides a method for manufacturing a coil joined body, in which an end face of a busbar made of a second metallic member is connected to an end face at the start and / or end of a winding of a coil made of a first metallic member, the method comprising the steps of: winding the coil while bending it in one direction, and an end of the coil is led out on an extension of a long side of a winding region of the coil without changing the direction of bending; the coil includes a coil straight portion having a straight region longer than the amount of pressing in a pressure welding step; and the busbar includes a busbar straight portion having a straight region longer than the amount of pressing in a pressure welding step; and butting the end faces of the busbar straight portion and the coil straight portion against each other and pressing them together so as to be shortened by the amount of pressing, to form a joint. Effect of the Invention

[0010] According to the present invention, it is possible to provide a coil connection body that simplifies the configuration of the connection portion between the coil and the wiring member (bus bar), simplifies the number of parts and the connection process, suppresses an increase in resistance at the connection portion, and ensures a good connection state. [Brief description of the drawings]

[0011] [Figure 1] 1A to 1C are schematic diagrams showing the appearance of a coil joined body of the present embodiment, in which (A) is a front view, (B) is a side view, and (C) is a side view. [Diagram 2] 1A to 1G are diagrams illustrating the coil of the present embodiment, in which (A) is a front view of the coil, (B) is a front view of a coil piece, (C) is a cross-sectional view of the coil piece, and (D) to (G) are front views of the coil piece. [Diagram 3] 1A to 1D are diagrams showing an outline of a bus bar according to an embodiment of the present invention, in which (A) is a front view, (B) is a side view, (C) is a perspective view, and (D) is a perspective view. [Figure 4] 1A, 1B, and 1C are schematic diagrams showing a bus bar according to an embodiment of the present invention; FIG. [Diagram 5] 4A to 4C are schematic front views showing a method for manufacturing a coil according to the present embodiment. [Figure 6]2A to 2G are diagrams illustrating a method for producing a coil joined body according to the present embodiment, in which (A) to (C) are schematic front views and (D) to (G) are side views. [Figure 7] 5A to 5C are schematic front views showing a method for manufacturing a coil joined body according to the present embodiment. [Figure 8] 5A to 5C are schematic diagrams illustrating a method for manufacturing a coil bonded body according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0013] <Coil assembly (coil with busbar)> FIG. 1 is a schematic diagram of the appearance of a coil bonded body 10 of the present embodiment, in which (A) is a front view as seen from the helical axis direction, (B) is a side view as seen from the left direction of FIG. 1A, and (C) is a side view as seen from below of FIG. 1A.

[0014] 2 shows an example of the coil 11 (spiral structure 50) and flat conductor C (C0) constituting the coil 11 according to this embodiment, where (A) is a front view of the completed coil 11 (spiral structure 50) seen from the axial direction of the spiral structure, (B) is a front view of the flat conductor C, and (C) is an enlarged cross section taken along line XX in (B). Also, (D) to (G) are front views showing an example of the shape of the flat conductor C.

[0015] Fig. 3 is a schematic diagram showing busbar 12. Fig. 3(A) to Fig. 3(C) are front views of busbar 12 corresponding to Fig. 1(A), and Fig. 3(D) is a side view corresponding to Fig. 1(C).

[0016] As shown in FIG. 1, a coil joined body 10 of this embodiment includes a coil 11 made of a wound first metal member 13 and a bus bar 12 made of a second metal member 14.

[0017] The coil assembly 10 of this embodiment is configured by pressing a bus bar (wiring member) 12 of any shape to an end 11E of the winding of the coil 11 (hereinafter, referred to as the coil end 11E). Hereinafter, the coil assembly 10 of this embodiment is referred to as a bus bar-attached coil 10. More specifically, the coil 11 has a pair of coil ends 11E (a starting end 11ES and a terminal end 11EE), and the bus bar 12 is connected to at least one of the coil ends 11E. As an example, the present embodiment will describe a configuration in which the bus bar-attached coil 10 has a bus bar 12 connected to both coil ends 11E (the starting end 11ES and the terminal end 11EE) of the coil 11. The shape of the bus bar 12 is arbitrary and is not limited to the shape shown in the figure. In this example, all the bus bars 12 have the same configuration (shape), but the bus bars 12 connected to the starting end 11ES and the terminal end 11EE may have different shapes. Furthermore, bus bar 12 may be connected to either of coil ends 11E (start end 11ES or end end 11EE).

[0018] The member of the coil 11 (first metal member 13) is a lightweight metal, for example, aluminum (Al). Also, the member of the busbar 12 (second metal member 14) is a metal different from the first metal member 13 in this example, and is preferably a metal with high conductivity, for example, copper (Cu). Note that the first metal member 13 and the second metal member 14 may be metal members of the same type (for example, copper, etc.).

[0019] The coil 11 of this embodiment is, as an example, attached to the teeth of a stator core to form a stator (fixed element), and in this case, all of the winding portions of the spiral structure of one coil 11 are wound so that they can be attached to one tooth. In other words, the coil 11 is a so-called concentrated winding coil wound so that the axes of the winding portions of the spiral structure are approximately aligned (so that the winding portions are approximately overlapped in the spiral axis direction of the coil 11). In this example, the coil 11 is a so-called edgewise coil wound around a flat conductor, and more specifically, a spiral structure 50 is formed by continuously connecting a plurality of band-shaped flat conductors (coil pieces) each having a straight portion.

[0020] The configuration of the coil 11 will be further described with reference to FIG. 2. As already described, the coil 11 of this embodiment is formed by connecting a plurality of band-shaped flat conductors C at their straight portions along the band longitudinal direction (spiral progression direction), butting the end faces of the flat conductors C in the spiral progression direction against each other and pressing (pressure welding, for example, cold pressure welding), and continuing them to a desired number of turns to form a helical structure 50. The corners of the windings of the one-turn region of the helical structure 50 (hereinafter referred to as the one-turn region CR) are approximately right angles, and both the outer circumferential side and the inner circumferential side are (approximately) rectangular in front view (FIG. 1A, FIG. 1A) seen from the axial direction of the helical structure 50. The flat conductors C constituting this coil 11 are also referred to as coil pieces C in the following description.

[0021] As shown in FIG. 1B, the flat conductor (coil piece) C of this embodiment is a conductor whose cut surface (XX line cross section) when cut in a direction (strip short-side direction BS) intersecting (perpendicular) the straight portion of the strip longitudinal direction BL (the direction of progression of the helical structure) is rectangular or rounded rectangular as shown in FIG. 1C. That is, the coil piece C has two opposing wide faces WS and two opposing narrow faces WT, and is a strip-shaped member that is long in a predetermined direction. In the following description, as an example of a flat conductor, a flat conductor whose cross section perpendicular to the strip longitudinal direction is (almost) rectangular as shown in the upper diagram of FIG. 1C will be described. The end surface TS of the coil 11 refers to the surface of the coil end 11E (start end 11ES and end end 11EE) that is parallel to the cut surface when cut in a direction intersecting (perpendicular) the straight portion extending in the direction of progression of the helical structure (strip longitudinal direction).

[0022] As shown in (D) to (G) of the same figure, each flat conductor (coil piece) C is obtained by punching, for example, an aluminum plate (for example, about 0.1 mm to 5 mm thick) into a desired shape, and has at least a straight portion STR. More specifically, the coil piece C has a straight portion and at least one direction change portion TN. Here, the direction change portion TN is a portion that is bent so as to change the extending direction in the strip longitudinal direction. More specifically, the coil piece C has at least a first straight portion STR1 that extends in a first direction along the strip longitudinal direction, a second straight portion STR2 that extends in a second direction, and a direction change portion TN that is disposed between the first straight portion STR1 and the second straight portion STR2. Here, the straight portion STR (the first straight portion STR1 and the second straight portion STR2) is a portion that is continuous with the end surface TS and has a straight region that is longer than the amount of pressure contact (pressing length) by pressing.

[0023] The coil pieces C having the direction change portions TN are bent in the same direction (always to the right or left in a plan view) along the strip longitudinal direction so as to form a spiral shape when connected. It is also desirable that at least one (preferably all) of the direction change portions TN is a corner portion that is not curved (e.g., approximately right-angled). In this example, the direction change portion TN is an approximately square region, as shown by hatching in the same figure (D). In addition, the end surface TS of the coil piece C in this embodiment is located on a straight portion excluding the direction change portion TN of the coil piece C.

[0024] More specifically, the coil pieces C are shaped as one of the following: an L-shape with one direction changer TN (FIG. 1(D)), a U-shape with two direction changers TN (FIG. 1(E)), a C-shape with three direction changers TN (FIG. 1(F)), or a C-shape with four direction changers TN (FIG. 1(G)). The multiple coil pieces C may all have the same shape, or may be a combination of at least one of the shapes shown in FIG. 1(D) to FIG. 1(G). Also, a combination of a coil piece C with at least one of the shapes shown in FIG. 1(D) to FIG. 1(G) and a linear (I-shaped) coil piece C without a direction changer TN may be used. Furthermore, although not shown, the coil pieces C may be O-shaped with four direction changers TN. In the following example, a case in which all the coil pieces C are U-shaped as shown in FIG. 1(E) will be described.

[0025] Such a plurality of flat conductors C are joined by pressure welding (for example, cold pressure welding) with their end faces TS in the spiral progression direction butted together. That is, the coil 11 is provided with pressure-welded joints 15 (see FIG. 1A) on the straight sections STR of the spiral structure 50 (one-turn region CR) except for the direction change sections TN (shown by dotted hatching in FIG. 1A) (the joints 15 are not included in the direction change sections TN (corners)).

[0026] Each of the coil ends 11E has a coil straight portion 11ST. The coil straight portion 11ST is a straight region that is continuous with the end face TS of the coil 11 and extends along the pressing direction P in the pressing (pressing) process, and the length of the straight region is longer than the pressing length (pressing amount) CPL. The pressing length CPL is the length that is shortened in the pressing process, and will be described later. The coil straight portion 11ST is also a straight portion STR of the unit coil piece C.

[0027] In Fig. 1A, the joint 15 is shown by a dashed line for the sake of convenience, but in the case of cold pressure welding in particular, the joint 15 is an atomic bond of metal, so it is firmly joined together to the extent that it is difficult to recognize (almost impossible to see) by visual inspection of the outside. This makes it possible to overwhelmingly increase the stability of the joint 15 compared to a configuration in which multiple coil pieces C are connected in a flat manner with an adhesive (fixing material, brazing, etc.) or connected by welding, etc.

[0028] In addition, the shape (particularly the shape of the inner circumference side) of the coil 11 in a plan view (FIG. 1A) can be made substantially rectangular, so that the space factor of the coil 11 can be increased when the coil 11 is attached to the stator of a motor, for example. This allows the motor using the coil 11 to have low resistance and high efficiency.

[0029] Furthermore, the weight of the coil 11 made of aluminum can be reduced to one-third of that of a coil of the same shape made of copper, and the cost can also be reduced to one-third.

[0030] Figures 3 and 4 are schematic diagrams showing an example of busbar 12. Figure 3(A) is a front view of busbar 12 corresponding to Figure 1(A), Figure 3(B) is a side view corresponding to Figure 1(C), and Figures 3(C) and 3(D) are perspective views. Figures 4(A) and 4(B) are front views of busbar 12 corresponding to Figure 1(A), and Figure 4(C) is a perspective view.

[0031] 1 and 3, busbar 12 is a wiring member that connects coil 11 to a configuration external to coil 11 (for example, other wiring members (other busbars), other components, terminals, etc.), and is made of a metal member with good conductivity, such as copper, and has a first end 12A that connects to coil end 11E and a second end 12B that connects to the external configuration. End face 12AS is exposed at first end 12A, and end face 12BS is exposed at second end 12B.

[0032] The shape of the busbar 12 is arbitrary depending on the configuration of the lead-out side of the coil 11, but for example, as shown in Fig. 1A, the first end 12A connected to the coil end 11E may have a flat conductor shape equivalent to that of the coil end 11E, and the second end 12B may have a different shape such as a flat conductor thinner (thicker) than the first end 12A. Also, from the first end 12A to the second end 12B, the busbar 12 may be configured to include one or more bent portions 12D in a two-dimensional plane, or as shown in Figs. 1B to 1D, the busbar 12 may be configured to include one or more bent portions 12D in a three-dimensional space, or may be configured by combining bent portions 12D in the two-dimensional space and bent portions 12D in the three-dimensional space.

[0033] Furthermore, as shown in Fig. 1C and Fig. 1D, the second end portion 12B may be provided with a terminal (or an engagement portion) 20 for connection with another component. Fig. 1C illustrates an example in which the bus bar 12 and the terminal 20 are made of the same metal material (e.g., copper).

[0034] Furthermore, as shown in Fig. 1D, when a terminal 20 is provided at the second end 12B of the busbar 12, the busbar 12 and the terminal 20 may be made of different metal members. As one example, the busbar 12 may be made of the same first metal member 13 (e.g., aluminum) as the coil 11, and the terminal 20 may be made of a different metal member (e.g., copper).

[0035] Furthermore, as shown in FIG. 4(A), the first end 12A may have a flat conductor shape similar to that of the coil end 11E, and the second end 12B may have a different shape such as a round wire. Also, as shown in FIG. 4(B), it may include a curved portion 12E. Also, as shown in FIG. 4(C), it may be bent (branched) in multiple directions so that there are multiple ends 12B, 12X in addition to the first end 12A, and in this case, the terminal 20 may be connected to at least one of the second end 12B and the other end 12X. Also, it may be configured by combining at least one of these (FIG. 3 and FIG. 4).

[0036] The busbar 12 includes a busbar wiring portion 12W that connects (between) the first end portion 12A and the second end portion 12B. The busbar wiring portion 12W also includes at least a busbar straight portion 12ST. Here, the busbar straight portion 12ST in this embodiment is a portion that is continuous with the first end portion 12A and has a straight region along the pressing direction P in the pressing (pressing) step, and the length of the straight region is longer than the pressing length (pressing amount) CPL. The busbar wiring portion 12W may also have another busbar straight portion 12ST' in addition to the busbar straight portion ST.

[0037] Specifically, the busbar wiring portion 12W has a shape including only the busbar straight portion 12ST (FIG. 4(A)), or a shape including a busbar straight portion 12ST and another busbar straight portion 12ST' and at least one direction change portion TN (FIGS. 3, 4(B), 4(C)), or a combination of at least any of the shapes shown in FIG. 3 and FIG. 4.

[0038] Here, the direction change portion TN is a portion that is bent (curved) so as to change the extending direction in the strip longitudinal direction (direction that becomes a current path). More specifically, when the busbar wiring portion 12D has a bent shape (FIGS. 3, 4(B), and 4(C)), the busbar wiring portion 12W has at least two straight portions that extend in different directions in the current path (for example, a busbar straight portion 12ST extending in a first direction and another busbar straight portion 12ST' extending in a second direction) and a direction change portion TN disposed between them (there may also be a direction change portion TN between two different other busbar straight portions 12ST'). The curved portion 12E shown in FIG. 4(B) is a part of the direction change portion TN.

[0039] 4(C), the busbar 12 is configured to branch from a first end 12A through a direction change portion TN to a second end 12B and another end 12X so as to have a substantially T-shape in side view, and is pressed downward in the figure. For this reason, a busbar straight portion 12ST that is longer than the pressing amount CPL is provided at the first end 12A along the pressing direction P.

[0040] In this embodiment, the coil end 11E and the first end 12A of the busbar 12 are directly butted together and joined. In detail, as shown in Fig. 1(A), an end face TS of the coil straight portion 11ST of the coil end 11E and an end face 12AS of the busbar straight portion 12ST of the first end 12A are butted together and pressed (for example, cold welding) to form a joint 16.

[0041] Here, end surface 12AS of busbar 12 is a terminal surface parallel to a cut surface when first end 12A (busbar straight portion 12ST) is cut in a direction intersecting (orthogonal to) pressing direction P in the pressing step.

[0042] That is, joint 16 formed by pressure welding between coil end 11E and first end 12A of busbar 12 is formed in straight section 10ST (straight section 10ST excluding direction change section TN of busbar coil 10) of busbar-equipped coil 10 after joining. In other words, joint 16 is located at a position not included in direction change section TN (corner section) of busbar-equipped coil 10 (FIG. 1(A)).

[0043] First end 12A of busbar 12 has end surface 12AS configured, for example, to have a shape (size) that matches the shape of coil piece C of coil end 11E.

[0044] Specifically, the end face 12AS of the first end 12A (busbar straight portion 12ST) is rectangular and of the same size (approximately the same rectangular shape) so as to substantially match the shape (rectangular shape in this example) of the end face TS of the coil straight portion 11ST of the coil end 11E. On the other hand, the shape of (the end face 12BS of) the second end 12B is arbitrarily selected depending on the shape of the wiring to be connected, etc.

[0045] In Figure 1, for ease of explanation, the joint 16 is shown by a dotted line, but in the case of cold pressure welding, the joint 16 is reliably joined integrally to the extent that the positions of the end face TS of the coil end 11E and the end face 12AS of the bus bar 12 are difficult to recognize (almost impossible to see) by visual inspection from the outside.

[0046] In the case where the coil 11 (first metal member 13) is made of aluminum, for example, and the bus bar 12 (second metal member 14) is made of copper, for example, as in the example of this embodiment, aluminum is prone to forming an oxide film and is easily deformed, so that joining by soldering (brazing) or general welding causes problems, such as creep deformation and insufficient joint strength being obtained, particularly in use in the large current range. Or, even with welding, special methods and devices are required to obtain sufficient joint strength, and it is not easy to perform. For this reason, conventionally, the two have often been joined by screws or the like.

[0047] However, when joining by screws, the structure of the joint 16 becomes complicated and large, so there is a limit to how much the resistance of the coil 11 can be reduced, and there are also problems such as an increase in the number of parts.

[0048] According to this embodiment, the bus bar 12 and the coil 11 are directly pressure-welded, which overwhelmingly improves the stability of the joint 16 and provides sufficient connection strength compared to configurations in which the bus bar 12 and the coil 11 are connected with an adhesive (fixing material, brazing, etc.) or by welding or screwing.

[0049] Furthermore, since the coil 11 and the bus bar 12 can be connected integrally (continuously and smoothly), the structure of the joint 16 can be avoided from becoming complicated (the joint 16 can be configured to the minimum necessary) compared to when the two are joined by welding, adhesive bonding, screwing, etc., and an increase in resistance at the joint 16 can be suppressed.

[0050] 3(D), 4(C), etc., joint 21 between aluminum busbar 12 and copper terminal 20 is also formed by pressure welding (cold pressure welding) like joint 16 between coil 11 and busbar 12 described in this embodiment. That is, the end face of second end 1B of busbar 12 and the end face of terminal 20 on the busbar 12 side are butted together and (cold) pressure welded to be joined.

[0051] Thus, according to the coil with busbar 10 of this embodiment, the coil 11 can be made of, for example, a lightweight first metal member 13 (such as aluminum), and the busbar 12 can be made of a second metal member 14 (such as copper) having good conductivity. Therefore, compared to the case where the coil 11 is manufactured from, for example, copper, the cost can be reduced to one-third and the weight can also be reduced to one-third. Furthermore, even if the coil 11 and the busbar 12 are made of different materials, sufficient joint strength can be obtained. Therefore, it can be used in a large current range, and when the coil is employed in a motor or the like, it can be made lightweight, inexpensive, and even more efficient.

[0052] Furthermore, since the coil 11 and the busbar 12 can be unitized, for example, in the manufacturing process of a stator (motor), if the coil with busbar 10 of this embodiment is attached to a stator core, the process of connecting the coil and the busbar is not required. In other words, a device for attaching the coil to the stator (a device for connecting the coil and the busbar) is not required, which makes it possible to reduce the size of the stator manufacturing device and simplify the stator manufacturing process. Note that this point is not limited to the case where the first metal member 13 and the second metal member 14 are made of different materials, but the same effect can be achieved even if they are made of the same material (for example, copper).

[0053] In this coil with bus bars 10, coil 11 is coated with resin with bus bars 12 exposed.

[0054] <Manufacturing method of coil with busbar> A method for manufacturing the coil with busbar 10 of this embodiment will be described with reference to Figs. 5 to 8. Fig. 5 is a schematic front view of the coil piece C seen from the helical axis direction of the coil 11. Fig. 6 is a diagram showing the state of connection between the coil 11 and the busbar 12, with Figs. 6(A) to 6(C) being schematic front views of the coil piece C and the busbar 12 seen from the helical axis direction of the coil 11, Fig. 6(D) being a side view of Fig. 6(A), Fig. 6(E) being a side view of Fig. 6(B), Fig. 6(F) and Fig. 6(G) being side views seen from the left direction of Fig. 6(C). Fig. 7 is a schematic front view of the coil piece C and the busbar 12 seen from the helical axis direction of the coil 11, and Fig. 8 is a diagram for explaining the state of connection between a plurality of coil pieces C, and is a schematic view of a state in which a plurality of coil pieces C are joined together, developed as a front view. Here, as an example, a method for forming the coil 11 by sequentially pressing a plurality of U-shaped coil pieces as shown in Fig. 2(E) will be described. In the following description, the coil pieces before joining are referred to as unit coil pieces C, and the joined coil pieces are referred to as joined coil pieces CC.

[0055] In the following description, the coil pieces C include a spiral structure in which a plurality of coil pieces (flat conductors) C are connected (connected), and a spiral structure (a spiral structure to which coil pieces C are to be subsequently connected) before being completed as a coil (finished spiral structure 50) 11. In other words, in the following description, the coil pieces C include minimum-unit coil pieces (coil pieces before connection) having one or more direction change sections TN in a linear shape or in the strip longitudinal direction, and coil pieces in which a plurality of such minimum-unit coil pieces are connected to form a spiral structure longer than one revolution region CR of the coil 11 (to-be-completed spiral structure 50). Furthermore, for ease of explanation, when it is necessary to distinguish between these, the smallest unit coil piece will be referred to as unit coil piece C0 (C01, C02, C03..., C0N), the joined coil pieces formed by connecting multiple unit coil pieces C0 and which have not yet become coil 11 (the to-be-completed spiral structure 50) will be referred to as joined coil piece CC (CC1, CC2..., CCN), and the to-be-completed (completed state) spiral structure 50 will be referred to as coil 11.

[0056] First, as shown in Fig. 4(A), two U-shaped unit coil pieces C01 and C02 are prepared to form one-turn region CR1 of the first turn of the spiral structure 50. In this example, the unit coil piece C01 including the coil end portion 11E (start end portion 11ES) has a U-shape with two long side regions of asymmetric lengths (upper diagram of Fig. 4(A)), while the other unit coil piece C02 has a U-shape with two long side regions of symmetric lengths (lower diagram of Fig. 4(A)).

[0057] The two U-shaped unit coil pieces C01, C02 can form a virtual one-turn region of a spiral structure (hereinafter, virtual one-turn region CR') when their end faces TS12, TS21 on one side of the strip longitudinal direction (spiral progression direction) are abutted against each other (before pressure welding) (Figure 1B).

[0058] Then, the unit coil pieces C01 and C02 are held by a joining device (pressure welding device) not shown, and one end face TS12 of the unit coil piece C01 and one end face TS21 of the unit coil piece C02 are butted against each other and pressed (cold pressure welding) to form a joined coil piece CC1. At this time, the joining device, for example, presses the end faces TS12 and TS21 against each other at the straight portions of the unit coil piece C01 and the unit coil piece C02, shortening the length of the straight portions, thereby making the length of the one-turn region of the joined coil piece CC1 (joined one-turn region) equal to the length of the one-turn region CR of the coil 11 (FIG. 1C).

[0059] When the unit coil pieces C01, C02 are butted together and pressed together, a joint 15 is formed, and a burr (not shown) protruding perpendicularly to the wide surface WS of the coil piece C is generated at the joint 15 due to extrusion. Therefore, after the joint 15 is formed, the burr is removed by cutting or machining. As mentioned above, the joint 15 is actually difficult (impossible) to see, but is shown by a solid line for convenience of explanation (the same applies below).

[0060] Next, for example, a unit coil piece C03 having the same shape as the unit coil piece C02 is prepared (FIG. 1(D)), and the other end face TS22 of the joined coil piece CC1 (for example, the unit coil piece C02) is similarly cold-pressurized to one end face TS31 of the unit coil piece C03 to form a joined coil piece CC2 (FIG. 1(E)). Note that in FIG. 1(D), FIG. 1(E) and subsequent figures, the unit coil piece C01 (joined unit coil piece C, joined coil piece CC) is not shown. Also, after pressure welding, burrs are removed from the joint 15.

[0061] Thereafter, by repeating the crimping and burr removal for a predetermined number of turns N as necessary, a coil 11 with a spiral structure having a one-circumference region CR of N turns is formed (FIG. 8(A)). As shown in FIG. 7, the final unit coil piece C0N (unit coil piece C0N including the coil end portion 11E (terminal portion 11EE)) also has an asymmetric U-shape in the lengths of its two long side regions, similar to the initial unit coil piece C01.

[0062] Next, as shown in Fig. 6(A) and (D), the starting end 11ES side of the coil 11 and the busbar 12 are held by a joining device, and as shown in Fig. 6(B) and (E), the starting end 11ES (end surface TS11) and the end surface 12AS of the first end 12A of the busbar 12 are butted against each other in the same manner as in the case of pressure welding between the coil pieces C. As already described, the coil 11 (coil end 11E) has a coil straight portion 11ST that is a straight region along the pressing direction P (indicated by a white arrow in Fig. 6(A), (B), (D), and (E)) and whose length is longer than the pressing length (pressing amount) CPL. Also, the busbar 12 has a busbar straight portion 12ST that is a straight region along the pressing direction P and whose length is longer than the pressing length (pressing amount) CPL. That is, an end face TS11 of the coil straight portion 11ST of the coil end portion 11E (starting end portion 11ES) and an end face 12AS of the busbar straight portion 12ST of the first end portion 12A are butted against each other.

[0063] Then, as shown in Figures 1C and 1F, with the two parts butted together, the coil straight portion 11ST and the busbar straight portion 12ST are pressed against each other by a predetermined pressure welding amount (pressing length) CPL along the extension direction of the straight lines of the coil straight portion 11ST and the busbar straight portion 12ST, thereby (cold) pressing them together.

[0064] That is, the unit coil piece C01 before joining is set so that the length 11LS (length of the long side region) along the pressing direction P of the region to be joined to the bus bar 12 is longer by the pressure contact amount CPL than the length 11LE (length of the long side region) along the pressing direction P after joining to the bus bar 12 (in the completed state). Similarly, the length 12LS of the bus bar 12 before joining is set so that it is longer by the pressure contact amount CPL than the length 12LE along the pressing direction P after joining to the coil 11 (in the completed state) (Figures 1B, 1E, 1C, and 1F).

[0065] For this reason, as described above, busbar straight portion 12ST of busbar 12 is set to have a straight region longer than pressure contact amount CPL.

[0066] In this way, end face TS11 of coil straight portion 11ST and end face 12AS of busbar straight portion 12ST are butted against each other and pressed together, shortening them by the amount of pressure contact CPL to form joint 16 between coil 11 and busbar 12. Therefore, joint 16 between coil 11 and busbar 12 is also formed in straight portion 10ST of busbar-equipped coil 10 (area excluding direction change portion TN (corner portion; indicated by dotted hatching in the figure)). In other words, joint 16 is not included in direction change portion TN (corner portion) of busbar-equipped coil 10.

[0067] Furthermore, burrs 60 are generated at the joints 16 due to extrusion, protruding perpendicularly to the wide faces WS of the coil pieces C. Therefore, after the formation of the joints 16, the burrs 60 are removed by cutting or machining (FIG. 1(G)). As mentioned above, the joints 16 are actually difficult (impossible) to see, but are shown by solid lines for convenience of explanation (the same applies below).

[0068] 7, a joining device is used to hold the terminal end 11EE side of the coil 11 and the other busbar 12 (FIG. 7(A)), and the terminal end 11EE (end face TSN2) and the end face 12AS of the first end 12A of the busbar 12 are butted together. More specifically, the end face TSN2 of the coil straight portion 11ST of the coil end 11E (terminal end 11EE) and the end face 12AS of the busbar straight portion 12ST of the first end 12A are butted together and brought into contact with each other (FIG. 7(B)).

[0069] Then, as shown in Fig. 8(C), with the two butted together, the coil straight portion 11ST and the busbar straight portion 12ST are pressed against each other by a predetermined pressure amount (pressing length) CPL along the pressing direction P (indicated by the outlined arrow) to (cold) press-weld them. This forms a joint 16 between the coil 11 and the busbar 12, and after pressure welding, burrs 60 are removed from the joint 16. In this way, a coil with busbars 10 is obtained, in which the busbars 12 are connected to the starting end 11ES and the ending end 11EE of the coil 11 (Fig. 8(B)).

[0070] The settings of the length 11LS before connection of the long side region of the unit coil piece C0N that connects to the bus bar 12, which becomes the terminal end 11EE of the coil 11, the length 12LS of the bus bar 12 before connection, the pressing amount CPL, and the respective lengths 11LE, 12LE after connection are similar to those of the starting end 11ES side of the coil 11 described in Figure 6, so description will be omitted.

[0071] 8(C) to 8(E), the busbar 12 may be pressure-welded in advance to a unit coil piece C01 that will be the starting end 11ES and a unit coil piece C0N that will be the end end 11EE, and the coil 11 may be manufactured by the above-mentioned method using the unit coil pieces C01 and C0N to which the busbar 12 is connected. Specifically, first, an end face 12AS of a busbar straight portion 12ST of a first end 12A of the busbar 12 and an end face TS11 of one coil straight portion 11ST of a first unit coil piece C01 are pressure-welded to form a joint coil piece CC1, and after pressure welding, burrs on the joint portion 16 are removed. In addition, the end face 12AS of the busbar straight portion 12ST of the first end 12A of the other busbar 12 is pressed against the end face TSN2 of one of the coil straight portions 11ST of the last unit coil piece C0N to form a joined coil piece CCN, and after the pressing, burrs are removed from the joint 16 (Figure 6(C)).

[0072] Then, one end face TS21 of the next unit coil piece C02 is connected to the other end (the other end of the unit coil piece O1) TS12 of the joint coil piece CC1, and after pressure welding, burrs are removed from the joint 15. Thereafter, unit coil pieces C are successively connected (FIG. 6(D)), and finally the joint coil piece CCN is pressure welded and burrs are removed to form the coil with bus bars 10 (FIG. 6(E)).

[0073] 3, a busbar 12 may be connected that has been previously processed (e.g., bent) into a predetermined shape as shown in Fig. 3, or may be processed into the predetermined shape after being joined to coil 11. Specifically, a busbar piece that is longer (larger) than the final shape may be pressed against coil 11 (or coil piece C), and then the busbar piece may be processed into a desired shape (anticipated as the final shape) by cutting, punching, cutting out, or the like.

[0074] After coil 11 and bus bar 12 are pressure-welded, coil 11 is coated with resin with bus bar 12 exposed.

[0075] The coil 11 of this embodiment has been described above as an edgewise coil in which a spiral structure is formed by pressing multiple coil pieces C together, but the coil 11 may be formed by preparing multiple round wire coil pieces (conductors) C with a substantially circular cross-sectional shape that intersects (orthogonally) in the longitudinal direction and pressing the end faces of both ends in the strip longitudinal direction together to form a spiral structure. The coil 11 may also be formed by winding a continuous long flat conductor or round wire conductor with a desired number of turns, or may be formed in part by butting end faces of multiple flat conductors (round wire conductors) together and pressing them together, and in part by winding the coil 11.

[0076] In the above example, the coil 11 is made of aluminum and the bus bar 12 is made of copper, but the metal members of the coil 11 and the bus bar 12 may be any metal member that can be cold-welded, such as a non-ferrous metal material. Specifically, the first metal member 13 and the second metal member 14 may each be a metal member such as aluminum, an aluminum alloy, a copper-nickel alloy, brass, zinc, silver, a silver alloy, nickel, gold, or other alloy, or may be a member that includes tin plating, silver plating, or nickel plating. In addition, the coil 11 (first metal member 13) and the bus bar 12 (second metal member 14) may be the same type (same) of metal member.

[0077] In addition, the coil with busbar 10 of this embodiment may include a third metal member different from both the first metal member 13 and the second metal member 14, in which case the end face of the third metal member may be butted (cold) pressure welded to the end face of the coil 11 and / or the end face of the busbar 12.

[0078] Further, the shape of the direction changer TN is not limited to a substantially square shape in a plan view, and may be a curved shape with a predetermined curvature.

[0079] Incidentally, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit and scope of the present invention. [Industrial Applicability]

[0080] The present invention can be applied to a stator and a motor. [Explanation of symbols]

[0081] 10 Coil assembly (coil with busbar) 10ST Straight section 11 Coil 11E Coil end 11ST Coil straight section 12A 1st end 12B 2nd end 12D bending section 12D Busbar wiring section 12E Curved section 12ST busbar straight section 12W busbar wiring section 15 Joint 16 Joint 20 Terminals 21 Joint 50 Spiral structure 60 Bali

Claims

[Claim 1] a coil made of a wound first metal member; A coil assembly including a bus bar made of a second metal member connected to an end portion of the start and / or end of the winding of the coil, The coil is wound while being bent in one direction, and the end portion is led out on an extension line of a long side of the winding region of the coil without changing the direction of the bend, a joint portion where end faces of the coil and the bus bar are butted against each other, a joined coil straight portion, and a joined bus bar straight portion, the post-joining coil straight portion is a straight region continuous with the joint portion, the post-joining busbar straight portion is a straight region continuous with the joint portion, a length of the joint body straight portion is shorter than a length of abutment between a coil straight portion of the coil before pressing and a busbar straight portion of the busbar before pressing; A coil joint comprising:

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