Busbar module

Abstract

To provide a busbar unit that can improve the ease of assembly and heat dissipation of the busbar. [Solution] One embodiment of the busbar module comprises a busbar 11 and a busbar case 20 made of insulating resin. The busbar 11 has a pair of connecting seats and conductive pieces 13. The busbar case 20 has openings that expose each connecting seat to the surface side. The busbar case 20 houses the busbar 11. The busbar case 20 includes a base wall 26 along the extending direction of the conductive pieces 13. A locking piece 27 is arranged on the base wall 26 to lock the conductive pieces 13 of the busbar 11. The locking piece 27 is provided with a regulating portion that engages with the conductive pieces 13 to restrict the position of the conductive pieces 13.

Description

Technical Field

[0001] Embodiments of the present invention relate to a bus bar module.

Background Art

[0002] In vehicles such as electric vehicles and hybrid cars, a battery pack (battery assembly) is used as the power source for the drive motor. The battery pack is configured by assembling a plurality of battery cells. The plurality of battery cells are, for example, connected in series by a bus bar such that the electrodes of adjacent battery cells are connected. When a bus bar is used in a battery pack or the like, each bus bar is housed in a bus bar case made of an insulating resin and used as a bus bar module (see, for example, Patent Document 1).

[0003] In the bus bar module described in Patent Document 1, the bus bar is housed in the bus bar case, and the surface side (opposite side to the battery pack) of the bus bar housing portion of the bus bar case is covered with a detachable insulating cover. The bus bar has a pair of connection seat portions connected to the electrodes (terminals) of the battery cells and a conduction piece portion that conducts the pair of connection seat portions. The bus bar case is provided with a bus bar housing portion capable of housing the bus bar from the surface side and an opening (through hole) in which a pair of connection seat portions of the bus bar are arranged. Each connection seat portion arranged in the opening is engaged with the corresponding electrode of the battery cell and connected to the corresponding electrode by fastening with a nut or the like. Further, the bus bar housed in the bus bar housing portion is prevented from coming off by a locking claw or the like provided on the bus bar case.

[0004] In a state where the bus bar is assembled in the bus bar housing portion, the surface side of the bus bar housing portion of the bus bar case is covered with the insulating cover. At this time, the insulating cover can maintain the bus bar in an insulated state with respect to the outside by covering the surface sides of the pair of connection seat portions and the conduction piece portion of the bus bar.

[0005] Furthermore, the busbar housing section of the busbar case has a covering wall that surrounds the connection seat of the busbar. The covering wall of the busbar housing section is set to minimize the gap between it and the connection seat of the busbar. This gap setting suppresses rattling of the busbar within the busbar housing section of the busbar module. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2014-229594 [Overview of the project] [Problems that the invention aims to solve]

[0007] The busbar module described in Patent Document 1 suppresses busbar rattle by setting a small gap between the cover wall of the busbar housing and the connection seat of the busbar. However, setting a small gap between the cover wall of the busbar housing and the connection seat of the busbar makes it difficult to assemble the busbar to the busbar housing.

[0008] Furthermore, the busbar module described in Patent Document 1 has a small gap between the covering wall of the busbar housing and the connection seat of the busbar, which tends to be disadvantageous in terms of heat dissipation of the connection seat.

[0009] The busbar module of one embodiment of the present invention provides a busbar module that can improve the ease of assembly and heat dissipation of the busbar. [Means for solving the problem]

[0010] A busbar module according to one embodiment of the present invention comprises a busbar having a pair of connection seats connected to corresponding terminals of an object to be mounted, and a conductive piece that connects the pair of connection seats, and an insulating resin busbar case that houses the busbar and has an opening that exposes each of the connection seats to the surface side opposite to the object to be mounted, wherein the busbar case has a base wall along the extending direction of the conductive piece, and a locking piece is disposed on the base wall for locking the conductive piece of the busbar, and the locking piece and the conductive piece are provided with regulating parts that engage with each other to restrict the position of the conductive piece. [Effects of the Invention]

[0011] According to the busbar module of one embodiment of the present invention, the ease of assembly and heat dissipation of the busbar can be improved. [Brief explanation of the drawing]

[0012] [Figure 1] This is a plan view of the busbar module of the embodiment. [Figure 2] This is a rear view of the busbar module of the embodiment. [Figure 3] This is an enlarged plan view of a portion of Figure 1 showing the busbar module of the embodiment. [Figure 4] This is a perspective view of a portion of the busbar module of the embodiment, seen from the front side. [Figure 5] This is an enlarged rear view of a portion of Figure 2 of the busbar module of the embodiment. [Figure 6] This is a perspective view of a portion of the busbar module of the embodiment, seen from the back side. [Figure 7] This is a rear view of a portion of the busbar module of the embodiment. [Figure 8] This is a cross-sectional view of the busbar module of the embodiment along the line VIII-VIII in Figure 5. [Figure 9] This is an enlarged view of section IX of the busbar module in the embodiment shown in Figure 8. [Modes for carrying out the invention]

[0013] The busbar module 10 of this embodiment will be described below with reference to the drawings. In this disclosure, terms are defined as follows: “Connection” may include, but is not limited to, a mechanical connection; and “Connection” may include, but is not limited to, a case where two elements to be connected are directly connected; and may include a case where two elements to be connected are connected with another element in between.

[0014] Figure 1 is a plan view of the busbar module 10 of this embodiment. Figure 2 is a rear view of the busbar module 10. The busbar module 10 of this embodiment is mounted on a battery pack (battery assembly) not shown. The battery pack is composed of multiple battery cells stacked together in a substantially rectangular shape. A pair of columnar electrodes 1 (positive and negative electrodes) protrude from one surface perpendicular to the stacking direction of each battery cell. The multiple battery cells are arranged such that the positions of the positive and negative electrodes are reversed in adjacent battery cells. The electrodes 1 of the stacked battery cells are arranged linearly with the positive and negative electrodes alternating in the stacking direction. The rows of electrodes 1, with the positive and negative electrodes arranged alternately, are arranged in two rows in a plan view of the battery pack. In this embodiment, the battery pack constitutes the object to be mounted, and the electrodes 1 (positive and negative electrodes) of each battery cell constitute the terminals of the object to be mounted.

[0015] The busbar module 10 includes multiple busbars 11, 11A for connecting the electrodes 1 of multiple battery packs in series. The busbars 11, 11A are formed from conductive metal plates. As shown in Figure 1, the multiple busbars 11, 11A are arranged in two layers, upper and lower, in a plan view of the busbar module 10. Each busbar 11, 11A connects the positive and negative electrodes of battery cells that are adjacent to each other in the stacking direction (left and right direction in Figures 1 and 2). Due to the relationship between the multiple busbars 11, 11A and the battery cells in series, the busbars 11, 11A arranged in the upper layer and the busbars 11A arranged in the lower layer are offset from each other in the left and right direction in a plan view.

[0016] In the bus bar module 10 of this embodiment, in the plan view shown in FIG. 1, only the bus bar 11 located at the center of the upper stage has a different shape, and the other bus bars 11A in the upper and lower stages have the same shape. The characteristic parts of the bus bar module 10 of this embodiment are the bus bar 11 located at the center of the upper stage, the bus bar case 20 described later that houses the bus bar 11, and the insulating cover 30 described later that covers a part of the surface side of the bus bar 11, which are the main components. Hereinafter, these main components will be described in detail.

[0017] In addition, the other bus bars 11A in the upper and lower stages have a pair of connection seat portions 12A having a rectangular shape in plan view, and a conduction piece portion 13A that conducts the pair of connection seat portions 12A. The conduction piece portion 13A extends between the pair of connection seat portions 12A. The plan view shape of each bus bar 11A combining the pair of connection seat portions 12A and the conduction piece portion 13A is formed in a horizontally long rectangular shape as shown in FIG. 1.

[0018] FIG. 3 is an enlarged plan view of a part of the bus bar module 10 (the upper central portion in FIG. 1), and FIG. 4 is a perspective view of the same part of the bus bar module 10 as viewed from the front side. Further, FIG. 5 is an enlarged rear view of a part of the bus bar module 10 (the upper central portion in FIG. 2), and FIG. 6 is a perspective view of the same part of the bus bar module 10 as viewed from the back side. The bus bar 11 at the center of the upper stage has a pair of connection seat portions 12 having a rectangular shape in plan view, and a conduction piece portion 13 that conducts the pair of connection seat portions 12. The conduction piece portion 13 is formed in a substantially U shape in plan view. Both ends of the substantially U-shaped conduction piece portion 13 on the opening side are connected to one side (the lower side in FIGS. 3 to 6) on the same side of each connection seat portion 12. The substantially U-shaped conduction piece portion 13 extends in a direction intersecting the arrangement direction of the pair of connection seat portions 12. Through holes 14 (see FIGS. 5 and 6) into which the electrodes 1 (see FIG. 1) of the corresponding battery cells are inserted are formed in each connection seat portion 12 of the bus bar 11.

[0019] The upper center busbar 11 differs from the other busbars 11A in that the spacing between the pair of connecting seats 12 is wider and the shape of the conductive piece 13 in plan view is approximately U-shaped. With the electrodes 1 inserted into the through holes 14 of the connecting seats 12, 12A of each busbar 11, 11A, nuts 15 are tightened onto the ends of the electrodes 1. Each electrode 1 is electrically connected to the corresponding connecting seats 12, 12A by being tightened with these nuts 15.

[0020] As shown in Figures 1 and 2, each busbar 11, 11A is housed in an insulating resin busbar case 20, 20A, and in this state, the side of the connection seat 12, 12A opposite to the side where the battery pack is placed is covered by an insulating cover 30. Each busbar case 20, 20A is connected to each other by a flexible connecting part 18. The busbar case 20A has a busbar housing section (not shown) that opens to the surface side, and the corresponding busbar 11A is housed in the busbar housing section from the surface side. The busbar 11A housed in the busbar housing section is locked to the busbar case 20A by a locking claw or the like (not shown).

[0021] In the following, the side of the busbar module 10 opposite to the side on which the battery pack (object to be mounted) is placed will be referred to as the "front side," and the side of the busbar module 10 on the same side as the side on which the battery pack (object to be mounted) is placed will be referred to as the "back side." The direction connecting the front side and the back side may also be referred to as the "front-back direction." Furthermore, for the sake of clarity in the following explanation, the upper part of Figures 1 to 6 will be referred to as "top," and the lower part of the figures will be referred to as "bottom." Also, the left-right direction in the figures will be referred to as the "left-right direction."

[0022] As shown in Figures 3 and 4, a pair of covering walls 22 are formed on the surface side of the busbar case 20, surrounding the periphery of the connection seat portion 12 of the busbar 11. Each covering wall 22 is formed in a substantially rectangular shape when viewed from above. The inside of each covering wall 22 penetrates in the front-to-back direction. This penetrating portion constitutes an opening 23 for exposing the connection seat portion 12 of the busbar 11 to the surface side.

[0023] Furthermore, as shown in Figures 3 to 6, a through-hole 24 is formed between the pair of covering walls 22, penetrating the busbar case 20 in the front-to-back direction. This through-hole 24 is formed in a roughly elliptical shape in plan view, elongated in the vertical direction. The through-hole 24 is surrounded by a peripheral wall 25 that stands upright in the front-to-back direction. A portion of the peripheral wall 25 is shared with each portion of the left and right covering walls 22. The peripheral wall 25 comprises a portion 25s shared with the left and right covering walls 22, an upper edge portion 25u located above the left and right shared portions 25s, and a lower edge portion 25l located below the left and right shared portions 25s. The lower edge portion 25l bulges concavely downward in the figure compared to the left and right covering walls 22.

[0024] The through-holes 24 formed in the busbar case 20 are holes for exposing bolt fastening parts, equipment operating parts, etc., that protrude from the outer surface of the battery pack to which the busbar module 10 is attached. These through-holes 24 are large in size to allow operation of large bolts and equipment. The shape of the through-holes 24 is not limited to an elliptical shape.

[0025] A base wall 26 (shielding wall) is provided on the lower side of the left and right covering walls 22 and peripheral wall 25 of the busbar case 20, extending in a direction substantially perpendicular to the upright direction of the covering walls 22 and peripheral wall 25. The substantially U-shaped conductive piece 13 of the busbar 11 is positioned on the back side of the base wall 26, along the base wall 26. When the busbar 11 is assembled to the busbar case 20, the base wall 26 shields the surface side of the conductive piece 13 of the busbar 11. The busbar case 20 is made of insulating resin. Therefore, the conductive piece 13 of the busbar 11 is electrically shielded on its surface side by the base wall 26.

[0026] Furthermore, as shown in Figures 5 and 6, a locking piece 27 is provided on the back side of the base wall 26 for engaging the conductive piece 13 of the busbar 11 from the back side. The upper end of the locking piece 27 is connected to the lower edge 25l of the peripheral wall 25 by an integral hinge 28. The integral hinge 28 is positioned approximately in the center in the left-right direction of the lower edge 25l of the peripheral wall 25. The locking piece 27 is integrally formed with the main body of the busbar case 20 via the integral hinge 28. The locking piece 27 is rotatable with the integral hinge 28 at its upper end as a pivot point. The locking piece 27 is displaceable between a closed position, which is close to (approximately parallel to) the back side of the base wall 26, and an open position, which is separated from the base wall 26.

[0027] Figure 7 is a rear view of a portion of the busbar module 10, showing the locking piece 27 in the open position. As shown in Figure 7, a locking claw 29 is integrally formed on the end of the locking piece 27 that is separated from the integral hinge 28. A locking portion (not shown) is formed on the back surface of the base wall 26 at a position opposite to the locking claw 29 of the locking piece 27. The locking piece 27 is locked in the closed position when the locking claw 29 engages with the locking portion. When the conductive piece 13 of the busbar 11 is set on the back surface of the base wall 26, and the locking piece 27 is locked in the closed position in this state, the approximately center position of the conductive piece 13 in the left-right direction is engaged with the locking piece 27.

[0028] As shown in Figure 7, a projection 40 with a rectangular cross-section protrudes from approximately the center of the back surface of the locking piece 27 (the surface facing the base wall 26 when closed). In contrast, a rectangular engagement hole 50 is formed approximately in the center of the conductive piece 13 of the busbar 11 in the left-right direction, penetrating the conductive piece 13 in the thickness direction. When the locking piece 27 is closed, the projection 40 of the locking piece 27 fits into this engagement hole 50 of the conductive piece 13. The positional displacement of the conductive piece 13 of the busbar 11 is restricted in the vertical and left-right directions by the fitting of the projection 40 and the engagement hole 50. In this embodiment, the projection 40 and the engagement hole 50 engage with each other to form a restricting portion that restricts the position of the conductive piece 13.

[0029] Figure 8 is a cross-sectional view of the busbar module 10 along the line VIII-VIII in Figure 5. Arrow F in Figure 8 points to the front surface of the busbar module 10. As shown in Figures 5, 6, and 8, a protruding piece 31 is integrally formed on one end of the conductive piece 13 of the busbar 11 (near the connection point with one of the connecting seat portions 12), projecting outward in the left-right direction.

[0030] At positions corresponding to the protruding piece 31 of the busbar case 20, an insertion hole 32 into which the protruding piece 31 is inserted from the inside in the left-right direction and a locking wall 33 are provided. The locking wall 33 is a wall continuous with the insertion hole 32, and the back surface of the protruding piece 31 inserted into the insertion hole 32 abuts against it. The busbar 11 restricts the displacement of the base of one of the conductive pieces 13 toward the back side by the back surface of the protruding piece 31 abutting against the locking wall 33. In this embodiment, the protruding piece 31 contacts the busbar case 20 (locking wall 33) to form a displacement restricting portion that restricts the displacement of the connecting seat portion 12 toward the rear side.

[0031] Next, we will explain how to assemble the busbars 11 to the busbar case 20. The locking piece 27 of the busbar case 20 is initially left open. In this state, the busbar 11 is positioned on the back side of the busbar case 20. From this state, as shown by the dashed line in Figure 8, the busbar 11 is tilted left and right, and the tip of the protruding piece 31 of the busbar 11 is inserted into the insertion hole 32 of the busbar case 20.

[0032] Next, as shown in Figure 8, the orientation of the busbar 11 is changed so that it is approximately parallel to the back surface of the base wall 26. At this time, the left and right connecting seats 12 of the busbar 11 are positioned within the corresponding openings 23 of the busbar case 20, and the conductive pieces 13 of the busbar 11 are positioned close to the back surface of the base wall 26 of the busbar case 20.

[0033] Next, the position of the busbar 11 is finely adjusted vertically and horizontally, and the locking piece 27 of the busbar case 20 is closed. At this time, the projection 40 on the back surface of the locking piece 27 is fitted into the engagement hole 50 on the conductive piece 13 of the busbar 11, and in this state, the locking claw 29 of the locking piece 27 is engaged with the locking part on the busbar case 20 side. As a result, the conductive piece 13 of the busbar 11 is assembled to the busbar case 20 in a position restricted (positioned) state by the locking piece 27.

[0034] Figure 9 is an enlarged view of section IX in Figure 8, showing the busbar 11 assembled to the busbar case 20. In the busbar module 10 of this embodiment, as described above, the busbar 11 can be positioned relative to the busbar case 20 by fitting the projection 40 of the locking piece 27 into the engagement hole 50 of the conductive piece 13. Therefore, as shown in Figure 9, a sufficient gap d can be secured between the connection seat portion 12 of the busbar 11 and the peripheral wall 25 of the busbar case 20. In the case of the busbar module 10 of this embodiment, this sufficient gap d allows the connection seat portion 12 of the busbar 11 to be easily assembled into the peripheral wall 25 of the busbar case 20.

[0035] The busbar module 10, in which the busbars 11 are assembled in the busbar case 20, is mounted on the battery pack, and the left and right connection seats 12 of the busbars 11 are connected to the corresponding electrodes 1 of the battery pack by nuts 15. After this, an insulating cover 30 is attached to the surface side of the busbar case 20.

[0036] As described above, the busbar module 10 of this embodiment has a busbar case 20 that includes a base wall 26 that is aligned with the extending direction of the conductive piece 13 of the busbar 11. A locking piece 27 that engages with the conductive piece 13 of the busbar 11 is disposed on the base wall 26, and the locking piece 27 and the conductive piece 13 are provided with regulating parts (projections 40 and engagement holes 50) that engage with each other to restrict the position of the conductive piece 13. In this case, the regulating parts provided on the locking piece 27 and the conductive piece 13 can suppress rattling of the busbar 11, so that the gap d between the conductive piece 13 of the busbar 11 and the busbar case 20 can be sufficiently widened. Therefore, by adopting the busbar module 10 of this embodiment, the ease of assembling the busbar can be improved, and the heat dissipation of the busbar 11 can also be enhanced.

[0037] Furthermore, in the busbar module 10 of this embodiment, an engagement hole 50 is provided in the conductive piece 13 of the busbar 11, and a projection 40 is provided on the locking piece 27 located on the back side of the base wall 26, and the projection 40 and the engagement hole 50 constitute a restricting portion. In this case, despite the extremely simple configuration, it is possible to simultaneously lock the busbar 11 to the conductive piece 13 and restrict its position.

[0038] Furthermore, in this embodiment, the busbar module 10 has a locking piece 27 that supports the conductive piece 13 of the busbar 11, which is integrally formed with the main body of the busbar case 20 via an integral hinge 28. With this configuration, the busbar module 10 of this embodiment does not require the separate assembly of the locking piece 27 to the busbar case 20. In addition, since the regulating portion can be engaged with the locking piece 27 supported by the integral hinge 28, the assembly of the busbar 11 to the busbar case 20 can be made easier.

[0039] Furthermore, in this embodiment, the busbar module 10 has a shape in which the conductive piece 13 of the busbar 11 extends in a substantially U-shape in a direction intersecting the direction in which the pair of connection seat portions 12 are aligned. This shape of the conductive piece 13 prevents the busbar module 10 from interfering with bolt fastening portions, device operating portions, etc., that protrude from the outer surface of the battery pack. Even with this shape of conductive piece 13 extending in a substantially U-shape, the busbar module 10 of this embodiment can stably support the conductive piece 13 on the back side of the base wall 26 and restrict the position of the busbar 11. Therefore, by adopting the busbar module 10 with this configuration, the support stability for the busbar 11 can also be improved.

[0040] Furthermore, in this embodiment, the busbar module 10 has a base wall 26 of the busbar case 20 that functions as a shielding wall that shields the surface side of the conductive piece 13 of the busbar 11. A locking piece 27 that engages with the conductive piece 13 of the busbar 11 is located on the back side of the base wall 26 that has the shielding function. In this case, when the busbar 11 is supported by the busbar case 20, the surface side of the conductive piece 13 of the busbar 11 can be electrically shielded by the base wall 26 that has the shielding function. Therefore, when the busbar module 10 of this embodiment is adopted, the vertical width of the insulating cover 30 that covers the surface side of the busbar 11 can be narrowed, making the insulating cover 30 smaller and lighter.

[0041] While embodiments of the present disclosure have been described above, these embodiments are provided as examples and are not intended to limit the scope of the present disclosure. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the present disclosure.

[0042] For example, in the above embodiment, a battery pack (battery assembly) is used as the object to which the busbar module is attached, but the object to which the busbar module is attached is not limited to a battery pack. The object to which it is attached can be any component having terminals for conducting electricity, such as a terminal block having terminals for relaying.

[0043] Furthermore, although the busbar 11 in the above embodiment has a shape in which a substantially U-shaped conductive piece 13 extends in one direction from a pair of connecting seats 12, the shape of the busbar 11 is not limited to this shape. The conductive piece of the busbar may have any shape other than a substantially U-shape as long as it extends in one direction from a pair of connecting seats.

[0044] Furthermore, in the above embodiment, a locking piece 27 that engages the conductive piece 13 of the busbar 11 with the back surface of the base wall 26 is integrally provided on the main body of the busbar case 20 via an integral hinge 28. However, the locking piece 27 can also be configured as a separate part from the main body of the busbar case 20. In this case, the locking piece 27 may be engaged with the main body of the busbar case 20 by means of engagement with protrusions or indentations.

[0045] Furthermore, in the above embodiment, the connection seat portion 12 of the busbar 11 is connected to the electrode 1, which is the terminal, by tightening (fastening) with a nut 15. However, the connection between the connection seat portion 12 and the terminal is not limited to fastening. Other methods besides fastening can be used to connect the connection seat portion 12 and the terminal. For example, the connection seat portion 12 may be connected to the terminal by welding or the like. [Explanation of symbols]

[0046] 10…Busbar Module 11…Bus bar 12…Connecting seat 13...Conducting piece 20... Bus bar case 23…Aperture 26... Base wall (shielding wall) 27… Locking piece 28…Integral Hinge 40...Protrusion (regulating part) 50…Engagement hole (regulating part)

Claims

1. A busbar having a pair of connecting seats that are connected to corresponding terminals of the object to be attached, and a conductive piece that connects the pair of connecting seats, Each of the aforementioned connection seats has an opening that exposes the surface side opposite to the object to be mounted, and comprises an insulating resin busbar case that houses the busbar, The busbar case comprises a base wall along the extending direction of the conductive piece, A locking piece is provided on the base wall for engaging the conductive piece of the busbar. The locking piece and the conductive piece are provided with regulating parts that engage with each other to restrict the position of the conductive piece. Busbar module.

2. The conductive piece is provided with an engagement hole that penetrates the conductive piece in the thickness direction of the plate. The locking piece is provided with a projection that fits into the engagement hole, The projection and the engagement hole constitute the restricting portion. The busbar module according to claim 1.

3. The locking piece is integrally provided with the busbar case via an integral hinge. The busbar module according to claim 1 or 2.

4. The conductive piece of the busbar extends in a substantially U-shape in a direction intersecting the direction in which the pair of connecting seats are aligned. The busbar module according to claim 1 or 2.

5. The base wall is a shielding wall that shields the surface side of the conductive piece, The locking piece is positioned on the back side of the shielding wall, which is on the same side as the object to be attached. The busbar module according to claim 1 or 2.

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