Busbar unit and manufacturing method thereof

Abstract

To provide a bus bar unit capable of suppressing distortion of a bus bar while improving yield, and a manufacturing method thereof.SOLUTION: A bus bar 51 comprises a first arcuate part 51a, a second arcuate part 51b and a single narrow part 51g. The first arcuate part 51a and the second arcuate part 51b are punched substantially into a J shape in which the arcuate parts are spread with the narrow part 51g defined as a center and the first arcuate part 51a and the second arcuate part 51b are then formed substantially in a C shape in which the arcuate parts are folded with the narrow part 51g defined as a center, thereby molding the bus bar 51. Therefore, when molding the bus bar 51 by means of a forward press machine, etc., in comparison with the punching substantial into the C shape from the beginning, a feed pitch of a workpiece to be punched can be narrowed and a yield rate can be improved as a result. Moreover, only the narrow part 51g is a folded portion, thereby suppressing a distortion occurrence rate of the bus bar 51.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a busbar unit including a plurality of busbars each provided corresponding to a plurality of phase coils and formed in a substantially C-shape when viewed in the axial direction, and an insulator that holds the plurality of busbars in a non-contact state, and a method for manufacturing the busbar unit. [Background technology]

[0002] Conventionally, brushless motors formed in a generally cylindrical shape have been used as drive sources for electric power steering devices and the like. An example of such a brushless motor is described in Patent Document 1. The brushless motor described in Patent Document 1 includes a stator wound with coils corresponding to U, V, and W phases, a rotor that rotates relative to the stator, and a busbar unit that distributes drive current to the coils corresponding to the U, V, and W phases. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2015-070632 Summary of the Invention [Problem to be solved by the invention]

[0004] In the busbar unit described in Patent Document 1, the three busbars for the U-phase, V-phase, and W-phase are formed in a roughly C-shape in the axial direction, with a relatively large space formed radially inside to accommodate the rotating shaft forming the rotor. This results in a low utilization rate of the coil material (the material that will become the busbars) fed by the progressive press, resulting in a poor yield. To address this issue, a possible solution is to punch out the busbar into a roughly I-shape (a roughly straight shape) before bending, as in the case of the single neutral busbar, and then bend the busbar at two longitudinal points to form a roughly C-shape in the axial direction.

[0005] However, while busbars have excellent conductivity, they are made of soft copper plates and the two bent sections are much thinner than the rest of the busbar. This creates a problem: when the busbar is resin-molded, the pressure of the molten resin is applied to the bent sections, which can deform the bent sections and cause distortion throughout the busbar. The presence of two bent sections in particular increases the likelihood of distortion, which needed to be suppressed.

[0006] An object of the present invention is to provide a busbar unit that can suppress distortion of the busbar while improving yield, and a method for manufacturing the same. [Means for solving the problem]

[0007] A busbar unit according to the present invention includes a plurality of busbars each provided corresponding to a plurality of phase coils and formed in a substantially C-shape when viewed in the axial direction, and an insulator that holds the plurality of busbars in a non-contact state with each other, Multiple The bus bar is Each is formed in the same shape, a first arc-shaped flat plate portion formed in a substantially arc shape when viewed in the axial direction; a power connection portion provided in a longitudinal center portion of the first arc-shaped portion and projecting from the radially outer side of the first arc-shaped portion in a direction in which the plane of the first arc-shaped portion widens; a second arc-shaped flat plate portion formed in a substantially arc shape when viewed in the axial direction and having a length dimension shorter than that of the first arc-shaped portion; coil connection portions provided on the first arc-shaped portion and the second arc-shaped portion and projecting from the radially outer side of the first arc-shaped portion and the second arc-shaped portion in a direction in which the planes of the first arc-shaped portion and the second arc-shaped portion widen; and a single narrow portion provided between the first arc-shaped portion and the second arc-shaped portion and having a width dimension smaller than that of the first arc-shaped portion and the second arc-shaped portion in the radial direction, the power supply connection portion and the coil connection portion are provided at equal intervals in the longitudinal direction of the first arc portion and the second arc portion, The coil connection portion may have a height that protrudes radially outward, the height being smaller than the height that protrudes radially outward of the power supply connection portion.

[0008] A method for manufacturing a busbar unit according to the present invention includes a plurality of busbars each provided corresponding to a plurality of phase coils and each formed in a substantially C-shape when viewed in an axial direction, and an insulator that holds the plurality of busbars in a non-contact state, the method comprising: The plurality of bus bars are each formed in the same shape, By punching a copper plate, a first arc-shaped flat plate portion formed in a substantially arc shape when viewed in the axial direction, a power supply connection portion provided at the longitudinal center of the first arc-shaped portion and protruding from the radially outer side of the first arc-shaped portion in a direction in which a plane of the first arc-shaped portion widens, a second arc-shaped flat plate portion formed in a substantially arc shape when viewed in the axial direction and having a length dimension shorter than that of the first arc-shaped portion, and a power supply connection portion provided at the first arc-shaped portion and the second arc-shaped portion and protruding from the radially outer side of the first arc-shaped portion and the second arc-shaped portion in a direction in which a plane of the first arc-shaped portion widens. a first step of forming a workpiece formed into a substantially J-shape, the workpiece having a coil connection portion that projects in a direction in which the plane of the arc portion widens and has a radially outward projection height that is smaller than the radially outward projection height of the power supply connection portion, and a single narrow portion that is provided between the first arc portion and the second arc portion and has a width dimension that is smaller than the radial width dimensions of the first arc portion and the second arc portion; and a second step of bending the narrow portion of the workpiece to form the substantially J-shape into a substantially C-shape when viewed in the axial direction. Thus, the power supply connection portion and the coil connection portion are provided at equal intervals in the longitudinal direction of the first arc portion and the second arc portion. The method comprises a second step, and a third step of setting the bus bars inside a mold so that they are not in contact with each other and are coaxial, and injecting molten resin material into the mold to form the insulator, wherein in the first step, the work is formed by punching out the copper plate with a progressive press, and the feed pitch of the progressive press is set so that the power supply connection portion of the front work enters radially inside the first arc portion of the rear work. [Effects of the Invention]

[0009] According to the present invention, a busbar includes a first arc portion, a second arc portion, and a single narrow portion. The busbar can be formed by punching the first arc portion and the second arc portion into a generally J-shape that opens at the narrow portion, and then bending the first arc portion and the second arc portion into a generally C-shape at the narrow portion. Therefore, when forming a busbar using a progressive press or the like, the feed pitch of the punched workpiece can be reduced compared to when the busbar is punched into a generally C-shape from the beginning, thereby improving the yield rate. Furthermore, because the bent portion is limited to the single narrow portion, the occurrence of distortion in the busbar can be reduced. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a perspective view of the brushless motor as seen from the cover member side. [Figure 2] FIG. 11 is a diagram in which the cover member is omitted. [Figure 3] FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 4] FIG. 2 is a perspective view showing a bus bar unit and a drive connector. [Figure 5] FIG. [Figure 6] FIG. 1 is a diagram illustrating an outline of a press working line. [Figure 7] FIG. 1 is a diagram illustrating the punching step (the present invention). [Figure 8] FIG. 10 is a diagram illustrating the punching step (comparative example). [Figure 9] FIG. 10 is a diagram illustrating the bending process. [Figure 10] FIG. 1 is a diagram illustrating the injection molding process. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0012] Figure 1 is an oblique view of the brushless motor seen from the cover member side, Figure 2 is a diagram in which the cover member is omitted, Figure 3 is a cross-sectional view along line AA in Figure 2, Figure 4 is an oblique view showing the bus bar unit and drive connector, Figure 5 is a front view of the bus bar alone, Figure 6 is a diagram explaining an overview of the press processing line, Figure 7 is a diagram explaining the "punching process (present invention)," Figure 8 is a diagram explaining the "punching process (comparative example)," Figure 9 is a diagram explaining the "bending process," and Figure 10 is a diagram explaining the "injection molding process."

[0013] The brushless motor 10 shown in Figures 1 to 3 is a motor device used as a drive source for an electric motorcycle or the like (a driven object). Specifically, the brushless motor 10 is mounted on a vehicle frame and drives the axle of a drive wheel via a chain or belt. However, the brushless motor 10 can also be mounted directly on the axle of a drive wheel.

[0014] Brushless motor 10 includes a housing 20 that forms the outer shell of brushless motor 10. Housing 20 includes an aluminum housing main body 21 formed in a generally cylindrical shape with a bottom, and an aluminum cover member 22 formed in a generally circular plate shape. Cover member 22 closes the open side of housing main body 21 (the upper side in FIGS. 1 and 3) via a gasket 23 (see FIGS. 1 and 3) that functions as a sealing member.

[0015] 3, a motor unit 40 is accommodated inside the housing 20. The motor unit 40 includes a stator 41 fixed to the inside of the housing body 21, and a rotor 42 that rotates radially inside the stator 41 via a minute gap (air gap).

[0016] The stator 41 has a stator core 41a formed into a generally cylindrical shape by laminating multiple steel plates (magnetic material). A plurality of teeth (not shown) are provided radially inside the stator core 41a, and coils 41c corresponding to the three phases, U, V, and W, are wound around these teeth by concentrated winding or the like, with insulators 41b made of a non-magnetic material such as plastic interposed therebetween.

[0017] An annular busbar unit 50 is provided on one axial side (upper side in FIG. 3) of the stator 41. The base ends Tb (see FIG. 4) of the U-phase power terminal TU, the V-phase power terminal TV, and the W-phase power terminal TW are electrically connected to the busbar unit 50. The busbar unit 50 distributes drive current to the coils 41c corresponding to the three phases, U, V, and W.

[0018] The rotor 42 includes a rotor body 42a formed into a generally cylindrical shape by laminating multiple steel plates (magnetic materials). A rotating shaft 42b made of a round steel bar is fixed to the center of rotation of the rotor body 42a. That is, the rotating shaft 42b rotates together with the rotor body 42a. A plurality of magnets 42c formed into a generally plate shape are provided inside the rotor body 42a. The magnets 42c are arranged so that the north and south poles appear alternately in the circumferential direction of the rotor body 42a.

[0019] However, this is not limited to the so-called "IPM (Interior Permanent Magnet) structure" in which multiple magnets 42c are embedded inside the rotor body 42a as described above, but it is also possible to adopt a so-called "SPM (Surface Permanent Magnet) structure" in which a magnet (not shown) is attached to the surface of the rotor body 42a.

[0020] A sensor magnet 42d formed in a substantially disk shape is fixed to one axial side of a rotating shaft 42b that forms the rotor 42. The sensor magnet 42d is used to detect the rotation state of the rotor 42 (rotating shaft 42b). The sensor magnet 42d faces a rotation sensor 44a provided on a sensor substrate 44 in the axial direction of the rotor 42.

[0021] One axial side of the rotating shaft 42b is rotatably supported by a first ball bearing BB1 mounted in a bearing holder 43. On the other hand, the other axial side (the lower side in FIG. 3) of the rotating shaft 42b is rotatably supported by a second ball bearing BB2 mounted in the housing main body 21.

[0022] The housing main body 21 has a bottom wall portion 21a formed in a substantially circular plate shape. A bearing mounting portion 21b and a seal mounting portion 21c formed in a substantially cylindrical shape are integrally provided in the center portion of the bottom wall portion 21a. The bearing mounting portion 21b and the seal mounting portion 21c are arranged coaxially. The bearing mounting portion 21b is provided inside the housing main body 21, and the outer ring of the second ball bearing BB2 is mounted radially inside the bearing mounting portion 21b. In contrast, the seal mounting portion 21c is provided outside the housing main body 21, and a rubber lip seal LS is mounted radially inside the seal mounting portion 21c.

[0023] The inner ring of the second ball bearing BB2 is attached to the other axial side of the rotating shaft 42b, and the lip seal LS is in contact with the outer periphery of the rotating shaft 42b at a portion closer to the outer side of the housing main body 21 than the second ball bearing BB2. This prevents rainwater, dust, and the like from entering the inside of the housing 20.

[0024] Furthermore, a total of four fixing legs 21d (only three are shown in Figs. 1 and 2) are provided on the radially outer side of bottom wall portion 21a outside housing main body 21. These fixing legs 21d are integrally provided at equal intervals (90-degree intervals) around the periphery of bottom wall portion 21a and are fixed via bolts to a body frame or the like that forms the skeleton of the motorcycle.

[0025] Furthermore, the housing main body 21 includes a cylindrical wall portion 21e formed in a generally cylindrical shape. The other axial side of the cylindrical wall portion 21e is integrally provided on the radially outer side of the bottom wall portion 21a. The stator core 41a is press-fitted into the radially inner side of the cylindrical wall portion 21e and firmly fixed thereto with an adhesive or the like. Furthermore, a plurality of cooling fins 21f are integrally provided on the radially outer side of the cylindrical wall portion 21e to radiate heat generated by the motor unit 40 (stator core 41a) when the brushless motor 10 is driven to the outside of the housing main body 21.

[0026] Furthermore, the housing main body 21 includes a polygonal wall portion 24. The polygonal wall portion 24 is integrally provided on one axial side (the upper side in FIG. 3) of the cylindrical wall portion 21e so as to be coaxial with the cylindrical wall portion 21e. As shown in FIG. 2, the polygonal wall portion 24 is formed in a substantially regular hexagonal shape when the housing main body 21 is viewed from one axial side.

[0027] Specifically, polygonal wall portion 24 has a first side portion 24a, a second side portion 24b, a third side portion 24c, a fourth side portion 24d, a fifth side portion 24e, and a sixth side portion 24f, and these six sides 24a to 24f form a substantially regular hexagon. An opening 24g is provided in polygonal wall portion 24, and a stator 41 and a rotor 42 (motor unit 40) are assembled into housing main body 21 through opening 24g. Opening 24g is sealed by cover member 22 via gasket 23.

[0028] A driving connector 25 is attached to the first side portion 24a, and the driving connector 25 is provided on one axial side of the housing 20. The driving connector 25 has a connector block 25a made of a resin material such as plastic, and the connector block 25a is fixed to the first side portion 24a by fixing screws or the like (not shown).

[0029] Connector block 25a is disposed outside housing 20, and specifically, protrudes radially outward from polygonal wall portion 24. Tip ends Tt (see FIG. 4) of U-phase power terminal TU, V-phase power terminal TV, and W-phase power terminal TW are exposed inside connector block 25a. Base ends Tb (see FIG. 4) of U-phase power terminal TU, V-phase power terminal TV, and W-phase power terminal TW are electrically connected to busbar units 50 accommodated inside housing 20.

[0030] Specifically, the base ends Tb of the U-phase power terminal TU, the V-phase power terminal TV, and the W-phase power terminal TW are fixed to the power connection portions 51e (see FIG. 4) of the U-phase, V-phase, and W-phase bus bars 51 by resistance welding or the like. Note that the fixing method is not limited to resistance welding, and may also be screw fastening, crimping, or the like.

[0031] 2, one end of a U-phase electric wire EU is electrically connected to the controller CU at its other end to the tip end Tt of the U-phase power terminal TU. Furthermore, one end of a V-phase electric wire EV is electrically connected to the controller CU at its other end to the tip end Tt of the V-phase power terminal TV. Furthermore, one end of a W-phase electric wire EW is electrically connected to the controller CU at its other end to the tip end Tt of the W-phase power terminal TW. This allows a drive current to be supplied to each coil 41c of the stator 41.

[0032] Here, connector block 25a faces a direction intersecting the axial direction of housing 20 (upward in FIG. 2). In other words, the connection directions of the other ends of U-phase, V-phase, and W-phase electric wires EU, EV, and EW to drive connector 25 are each a direction intersecting the axial direction of housing 20. Connector block 25a is fixed to first side portion 24a via a rubber seal member SM (see FIG. 3). This prevents rainwater, dust, and the like from entering the interior of housing 20 through connector block 25a.

[0033] As shown in FIG. 2 , a protrusion 26 is integrally formed on the polygonal wall portion 24, protruding radially outward from the housing 20. Specifically, the protrusion 26 protrudes radially outward from the housing 20 from a second side 24b located adjacent to the first side 24a. The protrusion 26 is formed in a substantially triangular shape when the housing 20 is viewed from one axial side, and includes an opening 26a and a bottom wall 26b that is also formed in a substantially triangular shape. The protrusion 26 also has a first side wall 26c and a second side wall 26d that rise from the bottom wall 26b toward one axial side of the housing 20. The second side 24b also rises from the bottom wall 26b toward one axial side of the housing 20.

[0034] In this way, the protrusion 26 is surrounded by the bottom wall 26b, the first side wall 26c, the second side wall 26d, and the second side portion 24b, and a connection space SP is formed inside the protrusion 26. That is, the connection space SP is provided on one axial side of the housing 20.

[0035] The connection space SP is a portion into which the controller-side connector portion 47 of the board wire harness 45 fits in the longitudinal direction. The connection space SP has the function of guiding (guiding) the controller-side connector portion 47 to the board connector 27 when connecting the controller-side connector portion 47 to the board connector 27. This makes it possible to easily connect the controller-side connector portion 47 to the board connector 27 when assembling the brushless motor 10.

[0036] Here, first side wall 26c is disposed on a general extension of first side portion 24a. Second side wall 26d is disposed on a general extension of third side portion 24c. This prevents protrusion 26 from protruding too far radially outward from housing 20. Opening 26a of protrusion 26 is also sealed by cover member 22 via gasket 23.

[0037] 1 to 3, the cover member 22 includes a main cover portion 22a that closes the opening 24g of the polygonal wall portion 24, and a sub-cover portion 22b that closes the opening 26a of the protrusion 26. The main cover portion 22a and the sub-cover portion 22b are integral with each other, with the main cover portion 22a formed in a generally circular plate shape and the sub-cover portion 22b formed in a generally triangular plate shape.

[0038] The cover member 22 is firmly fixed to the housing main body 21 by a total of seven fixing bolts BT distributed around the periphery of the cover member 22. When the cover member 22 is fixed to the housing main body 21, a gasket 23 is sandwiched between them.

[0039] A connector fixing portion 26e is integrally provided on a first side wall 26c of the protruding portion 26 so as to protrude radially outward from the housing 20. A board connector 27 is attached to the connector fixing portion 26e. Here, like the driving connector 25, the board connector 27 is also provided on one axial side of the housing 20.

[0040] The board connector 27 is formed into a predetermined shape from a resin material such as plastic and includes a fixing plate portion 27a formed in a substantially flat plate shape. The fixing plate portion 27a is fixed to the connector fixing portion 26e by a pair of first screws S1. A rubber seal member (not shown) is provided between the fixing plate portion 27a and the connector fixing portion 26e. This prevents rainwater, dust, etc. from entering the interior of the housing 20 through the board connector 27.

[0041] Furthermore, board connector 27 includes an inner connection portion (not shown) formed in a substantially box shape and an outer connection portion 27c. The inner connection portion is provided on the connector fixing portion 26e side of fixing plate portion 27a, and is disposed inside housing 20. In contrast, outer connection portion 27c is provided on the opposite side of fixing plate portion 27a from connector fixing portion 26e, and is disposed outside housing 20. Note that multiple conductive members (not shown) are embedded inside board connector 27 by insert molding or the like.

[0042] Here, the controller-side connector portion 47 of the board wire harness 45 is connected to the inner connection portion of the board connector 27 in the connection space SP inside the protrusion 26. Meanwhile, one end of a board electric wire SE (see FIG. 2 ), one end of which is electrically connected to the controller CU, is connected via a connector connection portion (not shown) to the outer connection portion 27c of the board connector 27. That is, the other end of the board electric wire SE is electrically connected to one end of a conductive member provided inside the board connector 27.

[0043] 1 and 2, connector block 25a, which is disposed outside housing 20, and outer connection portion 27c, which is also disposed outside housing 20, each face in the same direction (upward in FIG. 2) that intersects the axial direction of housing 20. When housing 20 is viewed from the direction intersecting the axial direction, drive connector 25 and board connector 27 are disposed adjacent to each other and aligned horizontally in a row in the direction intersecting the axial direction of housing 20. This improves the ease of handling of U-phase, V-phase, and W-phase electric wires EU, EV, and EW and board electric wire SE for brushless motor 10, and makes it possible to easily connect these electric wires EU, EV, EW, and SE to drive connector 25 and board connector 27, respectively.

[0044] Furthermore, when viewing housing 20 from a direction intersecting the axial direction, drive connector 25 and board connector 27 are each located within the range of the axial dimension of rotor 42, i.e., the range of the axial dimension of rotating shaft 42b (see FIG. 3). This reduces the axial dimension of brushless motor 10, thereby achieving a compact design of brushless motor 10.

[0045] As shown in FIGS. 2 and 3, an aluminum bearing holder 43 formed in the shape of a substantially regular hexagonal plate is provided on one axial side (upper side in FIG. 3) of housing main body 21. Bearing holder 43 is disposed radially inside polygonal wall portion 24, which is formed in the shape of a substantially regular hexagon, and holds first ball bearing BB1. Specifically, first ball bearing BB1 is mounted on a retaining cylinder 43a formed in the center of bearing holder 43. Retaining cylinder 43a protrudes toward the other axial side (lower side in FIG. 3) of housing main body 21 and fits radially inside busbar unit 50. This also reduces the axial dimension of brushless motor 10.

[0046] The bearing holder 43 is firmly fixed to one axial side of the housing body 21 by a total of six first fixing bolts B1. The six first fixing bolts B1 are dispersedly arranged near the corners of the bearing holder 43 and are fastened from one axial side of the housing body 21. This effectively suppresses distortion of the bearing holder 43 and ensures the positional accuracy of the first ball bearing BB1. This allows the rotor 42 to rotate smoothly. Furthermore, although the first fixing bolts B1 are provided inside the housing 20, even if they become loose and come off, they will not fall off toward the rotor 42, reliably preventing damage to the rotating parts.

[0047] Furthermore, a clip fixing portion 43b formed in a generally plate shape is provided on the opposite side of the bearing holder 43 from the rotor 42 side and in the vicinity of the protruding portion 26. The clip fixing portion 43b is disposed between adjacent first fixing bolts B1 and protrudes to one axial side of the housing 20 (the front side in FIG. 2). A clip member 49 fixed to the board wire harness 45 is fixed to the clip fixing portion 43b.

[0048] Furthermore, an annular support plate 43c that prevents the first ball bearing BB1 from falling off the retaining cylinder 43a is provided in the center of the bearing holder 43 on the side opposite the rotor 42. Specifically, the support plate 43c presses the outer ring of the first ball bearing BB1 with its radially inner portion, thereby ensuring smooth operation of the first ball bearing BB1.

[0049] The support plate 43c is fixed to the bearing holder 43 by a total of four second fixing bolts B2 (only three are shown in FIG. 2) arranged at equal intervals (90-degree intervals) around the circumference of the support plate 43c. Here, the second fixing bolts B2 are also provided inside the housing 20, but even if they become loose and come off, they will not fall off onto the rotor 42 side, reliably preventing damage to the rotating parts.

[0050] Furthermore, a total of four support pillars 43d are provided around the first ball bearing BB1 on the side of the bearing holder 43 opposite the rotor 42. These support pillars 43d each protrude by a predetermined height from one axial side of the housing 20, and a sensor board 44 is fixed to the tip of each support pillar 43d. In other words, a total of four support pillars 43d support the sensor board 44.

[0051] Specifically, the support columns 43d are arranged at equal intervals (90-degree intervals) around the first ball bearing BB1, and the sensor board 44 is fixed to a pair of diagonally arranged support columns 43d by a pair of second screws S2. Note that the second screws S2 are also provided inside the housing 20, but even if they loosen and come off, they will not fall off onto the rotor 42, reliably preventing damage to the rotating parts.

[0052] The sensor board 44, supported by a total of four support columns 43d, is provided on one axial side of the housing 20 and is a substantially square-shaped printed circuit board (PCB). A rotation sensor 44a made of a magnetoresistive element is provided in the center of the sensor board 44. The rotation sensor 44a faces, across a small gap, a sensor magnet 42d fixed to one axial side of the rotating shaft 42b in the axial direction of the housing 20 (see FIG. 3). This allows the rotation sensor 44a to detect the rotational state (rotation direction, rotation speed, etc.) of the rotating shaft 42b.

[0053] The sensor board 44 is also provided with a board-side connection portion 44b to which a board-side connector portion 48 of the board wire harness 45 is connected. As shown in Fig. 2, the board-side connection portion 44b provided on the sensor board 44 faces the connection space SP of the protrusion 26, which makes it possible to easily connect the board-side connector portion 48 to the board-side connection portion 44b.

[0054] Here, the board wire harness 45 is provided between the sensor board 44 and the board connector 27, and has the function of electrically connecting the controller CU (see FIG. 2) and the sensor board 44 inside the housing 20. Therefore, the detection signal of the rotation sensor 44a is sent to the controller CU via the board wire harness 45 and the board electric wire SE.

[0055] 3 to 5, the busbar unit 50 provided on one axial side of the stator 41 is formed in a generally annular shape when viewed in the axial direction. When the brushless motor 10 is assembled, a retaining cylinder 43a is disposed radially inside the busbar unit 50. Therefore, the first ball bearing BB1 and a portion of the rotating shaft 42b are also disposed radially inside the busbar unit 50. Here, the axial view in the present invention refers to the thickness direction of the busbar 51 in FIG. 4.

[0056] The busbar unit 50 includes three busbars 51 each formed in a substantially C-shape when viewed in the axial direction, and these busbars 51 are for the U-phase, V-phase, and W-phase (three-phase) coils 41c (see FIG. 3), respectively. Note that the three busbars 51 are each formed in the same shape, as shown in FIG. 5.

[0057] The busbar 51 is formed by punching and bending a sheet material (copper plate) made of oxygen-free copper (C1020) in this order using a progressive press 62 shown in Fig. 6. Here, oxygen-free copper (C1020) is pure copper with a purity of 99.96% or higher, and is a material that is highly conductive and flexible. Note that materials other than oxygen-free copper (C1020) can also be used depending on the specifications of the busbar unit 50.

[0058] The busbar unit 50 also includes busbar support portions 52 that hold the U-phase, V-phase, and W-phase busbars 51. The busbar support portions 52 correspond to the insulators of the present invention and are formed into an annular shape by injection molding a resin material such as plastic. Specifically, as shown in Fig. 4, the busbar support portions 52 hold the three busbars 51 coaxially, with each busbar 51 offset by a predetermined amount (approximately 30 degrees) in the circumferential direction and in a non-contact state (non-short-circuit state) with the busbars 51 not contacting each other.

[0059] The three bus bars 51 are stacked in an insulated state with minute gaps between them in the axial direction of the bus bar unit 50. Therefore, distortion of each bus bar 51 is something that needs to be reliably eliminated during the manufacture of the bus bar unit 50. In other words, in order to reduce the axial dimension of the bus bar unit 50 and thereby achieve a reduction in the overall size of the brushless motor 10, the bus bars 51 need to be precisely formed to prevent distortion.

[0060] As shown in FIGS. 4 and 5, busbar 51 includes a first arc-shaped portion 51a that is generally arc-shaped when viewed in the axial direction. The first arc-shaped portion 51a has a length dimension L1, and the first arc-shaped portion 51a occupies most of busbar 51. Busbar 51 also includes a second arc-shaped portion 51b that is generally arc-shaped when viewed in the axial direction. The second arc-shaped portion 51b has the same radius of curvature as the first arc-shaped portion 51a, and the length dimension L2 of second arc-shaped portion 51b is shorter than the length dimension L1 of first arc-shaped portion 51a. Specifically, the length dimension L2 is approximately 1 / 3 of the length dimension L1 (L2≈L1 / 3).

[0061] Coil connection portions 51c are integrally provided on both longitudinal sides of the first arc-shaped portion 51a and on one longitudinal side (right side in FIG. 5) of the second arc-shaped portion 51b. That is, a total of three coil connection portions 51c are provided on the bus bar 51. The interval between the pair of coil connection portions 51c provided on the first arc-shaped portion 51a is 180 degrees. The interval between the coil connection portion 51c on the other longitudinal side of the first arc-shaped portion 51a (lower side in FIG. 5) and the coil connection portion 51c on the second arc-shaped portion 51b is 90 degrees.

[0062] These three coil connection portions 51c protrude radially outward from the first arc-shaped portion 51a and the second arc-shaped portion 51b, and protrude from the first arc-shaped portion 51a and the second arc-shaped portion 51b by a height H1. The protruding height H1 of the coil connection portions 51c is approximately twice the width W1 of the first arc-shaped portion 51a and the second arc-shaped portion 51b in the radial direction of the bus bar 51 (H1 ≈ 2 × W1).

[0063] The coil connection portion 51c is formed in a substantially rectangular shape when viewed from the axial direction of the bus bar 51, and recesses 51d are provided on both longitudinal sides thereof to which the ends of the coil 41c (see FIG. 3) are connected. The openings of these recesses 51d face radially outward from the bus bar 51, allowing the ends of the coil 41c to fit from the radially outer side of the bus bar 51. The ends of the coil 41c that fit into the recesses 51d are electrically connected to the coil connection portion 51c by crimping both longitudinal sides of the coil connection portion 51c. Note that after crimping, the ends may be further fixed by soldering or the like. This makes it possible to more reliably electrically connect the ends of the coil 41c to the coil connection portion 51c.

[0064] Furthermore, a power supply connection portion 51e is integrally provided at the longitudinal center of the first arc-shaped portion 51a. The power supply connection portion 51e is disposed at a 90-degree angle with respect to both of the coil connection portions 51c provided on both longitudinal sides of the first arc-shaped portion 51a. The power supply connection portion 51e protrudes radially outward from the first arc-shaped portion 51a more than the coil connection portion 51c, and protrudes to a height H2 from the first arc-shaped portion 51a. Specifically, the protruding height H1 of the coil connection portion 51c is smaller than the protruding height H2 of the power supply connection portion 51e, and the protruding height H1 is approximately half the protruding height H2 (H1 ≈ H2 / 2).

[0065] The power supply connection part 51e is formed in a substantially rectangular shape when viewed in the axial direction of the bus bar 51. On both sides in the short side direction thereof, recesses 51f to which the ends of the coil 41c (see FIG. 3) are connected are provided. The portions on the opening side of these recesses 51f face the outside in the radial direction of the bus bar 51, and the ends of the coil 41c enter from the outside in the radial direction of the bus bar 51. Here, the ends of the coil 41c that have entered the recesses 51f are caulked on both sides in the short side direction of the power supply connection part 51e, and are thereby electrically connected to the power supply connection part 51e. Note that after caulking, further fixing may be performed by soldering or the like. Thereby, it becomes possible to more reliably electrically connect the ends of the coil 41c and the power supply connection part 51e.

[0066] Then, as shown in FIG. 4, the base ends Tb of the U-phase power supply terminal TU, the V-phase power supply terminal TV, and the W-phase power supply terminal TW are electrically connected to the tip end portion Tp on the tip end side in the longitudinal direction of the power supply connection part 51e.

[0067] Furthermore, a narrow portion 51g is provided between the first arc portion 51a and the second arc portion 51b. The width dimension W2 of the narrow portion 51g in the radial direction of the bus bar 51 is smaller than the width dimensions W1 of the first arc portion 51a and the second arc portion 51b (W2 < W1). That is, the narrow portion 51g has a lower rigidity than the first arc portion 51a and the second arc portion 51b.

[0068] In other words, the width dimensions W1 of the first arc portion 51a and the second arc portion 51b are larger than the width dimension W2 of the narrow portion 51g. Specifically, the width dimension W1 is approximately twice the width dimension W2 (W1 ≒ 2 × W2). Also, the thickness dimension in the direction intersecting the radial direction of the first arc portion 51a and the second arc portion 51b, that is, the plate thickness dimension of the bus bar 51 is T (see FIG. 4), and this plate thickness dimension T is approximately half of the width dimension W2 of the narrow portion 51g (T ≒ W2 / 2).

[0069] As described above, by forming busbar 51 from a plate made of oxygen-free copper (C1020), and by setting the dimensional relationships among first arc-shaped portion 51a, second arc-shaped portion 51b, and narrow portion 51g such that W1≈2×W2 and T≈W2 / 2, narrow portion 51g is prevented from being wrinkled or otherwise distorted while allowing deformation of narrow portion 51g in the radial direction of busbar 51. In other words, distortion of busbar 51 as a whole is effectively suppressed.

[0070] Next, a method for manufacturing the busbar unit 50 (busbars 51 and busbar supporting portions 52) formed as above will be described in detail with reference to FIGS.

[0071] Busbar 51 is formed by a press processing line PL shown in Fig. 6. Press processing line PL is equipped with, from upstream to downstream (from left to right in Fig. 6), an uncoiler 60, a leveler 61, and a progressive press 62. Uncoiler 60 rotatably supports coil material 60a, which is made by rolling a plate (copper plate) made of oxygen-free copper (C1020) and is the material for busbar 51. Coil material 60a is supplied from uncoiler 60 toward leveler 61.

[0072] The leveler 61 includes a plurality of work rolls 61a and pinch rollers 61b that feed the coil material 60a toward the progressive press 62. As the coil material 60a passes between the plurality of work rolls 61a, distortions such as the curling tendency of the rolled coil material 60a are removed, and the coil material 60a becomes flat. The feed amount of the coil material 60a in the leveler 61 is determined by the rotation speed of the pinch rollers 61b in the direction of arrow R1.

[0073] Thereafter, the coil material 60a that has been leveled and exits the leveler 61 is sent to a feeder 62a of a progressive press 62. The feeder 62a is equipped with a drive roller 62b, and the drive roller 62b is driven to rotate in the direction of arrow R2 to feed the coil material 60a into the progressive press 62. Here, the rotational speed of the pinch roller 61b in the direction of arrow R1 and the rotational speed of the drive roller 62b in the direction of arrow R2 are synchronously controlled by a controller (not shown).

[0074] The progressive press 62 includes a base 62c and a lifting member 62d that is driven to move up and down relative to the base 62c as indicated by the arrow M1. The coil material 60a fed from the feeder 62a passes between the base 62c and the lifting member 62d. The lifting and lowering operation of the lifting member 62d, along with the pinch roller 61b and the drive roller 62b, is synchronously controlled by a controller.

[0075] A punching unit 63 is provided upstream of the base 62c and the lifting member 62d (to the left of the progressive press 62) to punch out a workpiece W (see FIG. 7) from the coil material 60a to become the bus bar 51. The punching unit 63 includes a die 63a fixed to the base 62c and a punch 63b fixed to the lifting member 62d. When the lifting member 62d descends, the punch 63b moves toward the die 63a, thereby punching out the workpiece W from the coil material 60a.

[0076] Specifically, in the punching section 63, a workpiece W formed into a substantially J-shape is punched out from the coil material 60a, as shown by arrow M2 in Fig. 7. Here, in the punching section 63, the first arc-shaped portion 51a, the second arc-shaped portion 51b, the coil connection portion 51c, the power supply connection portion 51e, the recesses 51d and 51f (see Fig. 5), and the narrow width portion 51g are also simultaneously formed in the workpiece W.

[0077] Furthermore, the feed pitch P1 in the progressive press 62 is set so that the power supply connection portion 51e of the front work W(3) is positioned radially inside the first arc portion 51a of the rear work W(4), thereby increasing the yield rate. For example, it is possible to take out approximately three works W within the range of unit length L of the coil material 60a.

[0078] 8, when a workpiece W previously formed into a substantially C-shape is removed, the feed pitch P2 is approximately three times the feed pitch P1 (P2 ≈ 3 × P1). Therefore, only one workpiece W can be removed within the range of unit length L of the coil material 60a. In this manner, the yield rate in this embodiment is approximately three times higher than that in the comparative example.

[0079] In this way, the process of forming the workpiece W in the punching section 63 of the progressive press 62, that is, the "punching process" shown in FIG. 7, corresponds to the first process in the present invention.

[0080] 6, a bending unit 64 is provided downstream of the base 62c and the lifting member 62d (to the right of the progressive press 62) to bend the workpiece W formed by the punching unit 63 from a substantially J-shape (see FIG. 7) to a substantially C-shape (see FIG. 5). As shown in FIG. 9, the bending unit 64 includes a support protrusion 64a fixed on the base 62c and a slide member 64b that is slidable on the base 62c. The bending unit 64 also includes a pressing member 64c (see FIG. 6) that is provided on the lifting member 62d and moves the slide member 64b toward the support protrusion 64a as indicated by arrow M3 in FIG. 9 as the lifting member 62d descends.

[0081] In addition, a tapered cam (not shown) is provided between the slide member 64b and the pressing member 64c, which converts the downward movement of the pressing member 64c into lateral movement of the slide member 64b, thereby moving the slide member 64b closer to the support protrusion 64a.

[0082] 9, the substantially J-shaped workpiece W supplied between the support protrusion 64a and the slide member 64b is bent as indicated by the dashed line and plastically deformed to a substantially C-shape when viewed in the axial direction. Specifically, the coil connection portion 51c of the second arc-shaped portion 51b of the workpiece W is pressed by the slide member 64b, thereby bending the single narrow portion 51g between the first arc-shaped portion 51a and the second arc-shaped portion 51b. At this time, only one location of the narrow portion 51g of the workpiece W is plastically deformed around the narrow portion 51g. Therefore, distortion of the entire busbar 51 after shaping is suppressed, and the busbar 51 can be shaped more accurately than before.

[0083] In this way, the progressive press 62 performs both the "punching process" by the punching unit 63 and the "bending process" by the bending unit 64 with one lifting operation of the lifting member 62d that forms the progressive press 62. The "bending process" shown in Fig. 9 corresponds to the second process in the present invention.

[0084] After the bending step, bus bar 51 is finished into the shape shown in FIG. 5, and is then discharged downstream of progressive press machine 62 as shown by arrow M4 in FIG. 6, and collected in stocker ST.

[0085] The bus bars 51 collected in the stocker ST are transferred to the "injection molding process" shown in Fig. 10. The "injection molding process" corresponds to the third process in the present invention, and an injection molding apparatus 70 is used. The injection molding apparatus 70 includes a lower mold 71 fixed to a base (not shown) and an upper mold 72 that is driven to move up and down relative to the lower mold 71. The upper mold 72 is provided with a flow path 72a through which the molten resin MR flows, and a dispenser DP that injects the molten resin MR at a predetermined pressure is provided upstream of the flow path 72a (upper side in Fig. 10).

[0086] Then, three bus bars 51 for the U phase, V phase, and W phase are set in the lower mold 71. At this time, the three bus bars 51 are set in the lower mold 71 so that they are not in contact with one another and are coaxial. Thereafter, in this state, the upper mold 72 is driven downward and abuts against the lower mold 71. This forms a cavity CA that will form the bus bar support portion 52 inside the upper and lower molds 71, 72. Next, as shown by arrow M5 in the figure, the dispenser DP is driven to supply molten resin MR into the flow path 72a at a predetermined pressure. As a result, the molten resin MR is injected into the cavity CA, and the bus bar support portion 52 is formed.

[0087] Here, the molten resin MR supplied from the dispenser DP has a certain degree of viscosity, and needs to be able to spread throughout the narrow gaps between the bus bars 51. Therefore, the molten resin MR is filled into the cavity CA with a relatively large pressure.

[0088] At this time, among the first arc-shaped portion 51a, the second arc-shaped portion 51b, and the narrow portion 51g (see FIG. 5), there is only one narrow portion 51g that is most susceptible to deformation, and the dimensional relationships among the first arc-shaped portion 51a, the second arc-shaped portion 51b, and the narrow portion 51g are set to satisfy W1 ≈ 2 × W2 and T ≈ W2 / 2. Therefore, the rigidity of the narrow portion 51g is not significantly reduced relative to the first arc-shaped portion 51a and the second arc-shaped portion 51b. This effectively prevents the bus bars 51 from being distorted by the pressure of the molten resin MR, and ultimately prevents the bus bars 51 from shorting out with each other.

[0089] Thereafter, the upper and lower molds 71, 72 are forcibly cooled by water cooling or the like to harden the molten resin MR. Alternatively, the upper and lower molds 71, 72 may be left for a while to cool naturally. Next, as shown by arrow M6 in the figure, the upper mold 72 is driven upward to separate it from the lower mold 71, and the hardened busbar support portion 52 is released from the lower mold 71. This completes the busbar unit 50.

[0090] As described above, according to this embodiment, bus bar 51 includes first arc-shaped portion 51a, second arc-shaped portion 51b, and single narrow portion 51g. After punching first arc-shaped portion 51a and second arc-shaped portion 51b into a generally J-shape that opens around narrow portion 51g, bus bar 51 can be formed by bending first arc-shaped portion 51a and second arc-shaped portion 51b around narrow portion 51g into a generally C-shape. Therefore, when forming bus bar 51 using progressive press 62 or the like, the feed pitch P1 of workpiece W to be punched can be reduced compared to punching into a generally C-shape from the beginning, thereby improving the yield rate. Furthermore, since the bent portion can be limited to single narrow portion 51g, the occurrence of distortion in bus bar 51 can be reduced.

[0091] Furthermore, according to this embodiment, the radially outward protrusion height H1 of the coil connection portion 51c is smaller than the radially outward protrusion height H2 of the power supply connection portion 51e. Therefore, when setting the three bus bars 51 for the U phase, V phase, and W phase in the lower mold 71, the power supply connection portion 51e serves as a marker, making it possible to accurately set each bus bar 51 in the lower mold 71 without making a mistake. This improves the ease of assembly of the bus bar unit 50.

[0092] Furthermore, according to this embodiment, the thickness dimension (plate thickness dimension T) in a direction intersecting the radial direction of the first arc portion 51a and the second arc portion 51b is approximately 1 / 2 the width dimension W2 of the narrow portion 51g (T ≒ W2 / 2), and the width dimension W1 of the first arc portion 51a and the second arc portion 51b is approximately twice the width dimension W2 of the narrow portion 51g (W1 ≒ 2 × W2).

[0093] This allows deformation of the narrow width portion 51g in the radial direction of the bus bar 51, while preventing wrinkles or other distortions from occurring in the narrow width portion 51g, thereby effectively preventing distortion of the entire bus bar 51. Furthermore, since the rigidity of the narrow width portion 51g is not significantly reduced relative to the first arc-shaped portion 51a and the second arc-shaped portion 51b, distortion of each bus bar 51 due to the pressure of the molten resin MR is effectively prevented. This prevents the bus bars 51 from shorting out with each other inside the bus bar support portion 52, significantly reducing the rate of defects in the bus bar unit 50.

[0094] Furthermore, according to this embodiment, busbar 51 is formed from a plate material made of oxygen-free copper (C1020), which makes busbar 51 highly conductive and flexible. Therefore, only the narrow portion 51g (only one location) can be deformed, which improves control of the deformed portion and prevents the distortion from propagating to other portions. Therefore, distortion of the entire busbar 51 can be effectively prevented.

[0095] Furthermore, according to this embodiment, in the "punching process," the work W is formed by punching out the coil material 60a with a progressive press 62, and the feed pitch P1 of the progressive press 62 is set so that the power supply connection portion 51e of the front work W (3) enters the radially inner side of the first arc portion 51a of the rear work W (4). This makes it possible to take out many works W within the range of the unit length L of the coil material 60a, and ultimately makes it possible to significantly improve the yield rate compared to taking out a work W that has been previously formed into a substantially C-shape (see FIG. 8).

[0096] Furthermore, according to this embodiment, the progressive press 62 performs both the punching process and the bending process with a single lifting and lowering operation of the lifting member 62d that forms the progressive press 62, which makes it possible to reduce the amount of electricity (manufacturing energy) required to manufacture the bus bar 51 compared to a system that performs the punching process and the bending process separately.

[0097] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and scope of the present invention. In the above-described embodiment, the brushless motor 10 equipped with the busbar unit 50 is applied to a drive source for an electric motorcycle or the like, but the present invention is not limited to this. For example, the brushless motor 10 can be applied to a drive source for small mobility devices such as an electric wheelchair or an electric pushcart, a drive source for the joints of an arm robot, or even a drive source for a power steering device.

[0098] Furthermore, the material, shape, size, number, installation location, etc. of each component in the above-described embodiments are arbitrary as long as they can achieve the present invention, and are not limited to the above-described embodiments. [Explanation of symbols]

[0099] 10: brushless motor, 20: housing, 21: housing body, 21a: bottom wall portion, 21b: bearing mounting portion, 21c: seal mounting portion, 21d: fixing leg, 21e: cylindrical wall portion, 21f: cooling fin, 22: cover member, 22a: main cover portion, 22b: sub-cover portion, 23: gasket, 24: polygonal wall portion, 24a: first side portion, 24b: second side portion, 24c: third side portion, 24d: fourth side portion, 24e: fifth side portion, 24f: sixth side portion, 24g: opening, 25: drive connector, 25a: connector block, 26: protrusion, 26a: opening, 26b: bottom wall, 26c : First side wall, 26d: Second side wall, 26e: Connector fixing portion, 27: Board connector, 27a: Fixing plate portion, 27c: Outer connection portion, 40: Motor unit, 41: Stator, 41a: Stator core, 41b: Insulator, 41c: Coil, 42: Rotor, 42a: Rotor body, 42b: Rotating shaft, 42c: Magnet, 42d: Sensor magnet, 43: Bearing holder, 43a: Retaining cylinder, 43b: Clip fixing portion, 43c: Support plate, 43d: Support pillar, 44: Sensor board, 44a: Rotation sensor, 44b: Board side connection portion, 45: Board wire harness s, 47: Controller side connector part, 48: Board side connector part, 49: Clip member, 50: Busbar unit, 51: Busbar, 51a: First arc part, 51b: Second arc part, 51c: Coil connection part, 51d: Recess, 51e: Power supply connection part, 51f: Recess, 51g: Narrow width part, 52: Busbar support part (insulator), 60: Uncoiler, 60a: Coil material (plate material, copper plate), 61: Leveler, 61a: Work roll, 61b: Pinch roller, 62: Progressive press machine, 62a: Feeder, 62b: Drive roller, 62c: Base, 62d: Lifting member, 63: Punching part, 6 3a: die, 63b: punch, 64: bending portion, 64a: support protrusion, 64b: slide member, 64c: pressing member, 70: injection molding device, 71: lower mold, 72: upper mold, 72a: flow passage, B1: first fixing bolt, B2: second fixing bolt, BB1: first ball bearing, BB2: second ball bearing, BT: fixing bolt, CA: cavity, CU: controller, DP: dispenser, EU: U-phase electric wire, EV: V-phase electric wire, EW: W-phase electric wire, LS: lip seal, MR: molten resin, PL: press processing line, SE: board electric wire, SM: sealing member,SP: Connection space, ST: Stocker, Tb: Base end, Tp: Tip, Tt: Tip, TU: U-phase power terminal, TV: V-phase power terminal, TW: W-phase power terminal, W: Work,

Claims

1. a plurality of bus bars provided corresponding to the coils of the plurality of phases and formed in a substantially C-shape when viewed in the axial direction; an insulator that holds the plurality of bus bars in a non-contact state; A busbar unit comprising: The plurality of bus bars include Each is formed in the same shape, a first arcuate portion having a flat plate shape formed in a substantially arcuate shape when viewed in the axial direction; a power supply connection portion provided at a longitudinal center portion of the first arc portion and protruding from a radially outer side of the first arc portion in a direction in which a plane of the first arc portion widens; a second arcuate portion having a flat plate shape and a length dimension shorter than that of the first arcuate portion when viewed in the axial direction; a coil connection portion provided on the first arc portion and the second arc portion, and protruding from radially outer sides of the first arc portion and the second arc portion in a direction in which planes of the first arc portion and the second arc portion extend; a single narrow portion provided between the first arc portion and the second arc portion, the narrow portion having a width dimension smaller than the width dimensions of the first arc portion and the second arc portion in the radial direction; the power supply connection portion and the coil connection portion are provided at equal intervals in the longitudinal direction of the first arc portion and the second arc portion, a height of the coil connection portion protruding outward in the radial direction is smaller than a height of the power supply connection portion protruding outward in the radial direction, Busbar unit.

2. a thickness dimension of the first arc portion and the second arc portion in a direction intersecting with the radial direction is approximately half the width dimension of the narrow portion, and a width dimension of the first arc portion and the second arc portion is approximately twice the width dimension of the narrow portion, The busbar unit according to claim 1 .

3. The bus bar is formed from an oxygen-free copper plate material. The busbar unit according to claim 1 or 2.

4. a plurality of bus bars provided corresponding to the coils of the plurality of phases and formed in a substantially C-shape when viewed in the axial direction; an insulator that holds the plurality of bus bars in a non-contact state; A method for manufacturing a busbar unit comprising: The plurality of bus bars include Each is formed in the same shape, a first step of forming a workpiece formed into a substantially J-shape by punching a copper plate, the workpiece having: a flat first arc portion formed in a substantially arc shape when viewed in the axial direction; a power connection portion provided in a longitudinal center of the first arc portion and protruding from the radial outside of the first arc portion in a direction in which a plane of the first arc portion widens; a flat second arc portion formed in a substantially arc shape when viewed in the axial direction and having a length dimension shorter than that of the first arc portion; coil connection portions provided on the first arc portion and the second arc portion and protruding from the radial outside of the first arc portion and the second arc portion in a direction in which the planes of the first arc portion and the second arc portion widen, the coil connection portions protruding to a radially outward height that is smaller than a radially outward height of the power connection portion; and a single narrow portion provided between the first arc portion and the second arc portion and having a width dimension smaller than a width dimension in the radial direction of the first arc portion and the second arc portion; a second step of bending the narrow width portion of the workpiece to form the workpiece, which has been formed into a substantially J-shape, into a substantially C-shape when viewed in the axial direction, so that the power supply connection portion and the coil connection portion are provided at equal intervals in the longitudinal direction of the first arc portion and the second arc portion; a third step of setting the plurality of bus bars in a mold so that the bus bars are not in contact with each other and are coaxial, and injecting a molten resin material into the mold to form the insulator; In the first step, the work is formed by punching the copper plate with a progressive press, and a feed pitch of the progressive press is set so that a portion of the power supply connection portion of a front work enters a radially inner side of the first arc portion of a rear work. A manufacturing method of a busbar unit.

5. The progressive press machine is characterized in that both the first step and the second step are performed by a single lifting and lowering operation of a lifting member that forms the progressive press machine. The method for manufacturing the busbar unit according to claim 4 .

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