Bus bar module case and bus bar module

Abstract

To provide a bus bar module case and a bus bar module capable of properly realizing the treatment of water drops accumulated in a bus bar cavity.SOLUTION: The bus bar module case 100 accommodates therein a bus bar 2 that connects electrodes 211n of a plurality of battery cells 211 arranged side by side, and includes a bus bar cavity 20 having a sidewall 21 erected around an end edge 2b of the bus bar 2, and the sidewall 21 is provided with a drain hole 25 that communicates the inside and the outside of the bus bar cavity 20. The bus bar module 1 includes a bus bar 2, a wiring material 3, and a bus bar module case 100. The edge portion 26 of the drain hole 25 includes tapered guide portions 26a and 26b that are inclined so as to reduce the cross-sectional area of the drain hole 25 from the inside to the outside of the bus bar cavity 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a busbar module case and a busbar module. [Background technology]

[0002] As an example of technology relating to conventional busbar module cases and busbar modules, Patent Document 1 discloses a busbar module that is attached to the side of a battery assembly to form a power supply device. The busbar module has a case that includes multiple busbar housings, voltage detection terminals provided adjacent to each busbar housing, a wiring section for wiring voltage detection wires connected to the voltage detection terminals, and a cover that covers a predetermined area of ​​the wiring section. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-93218 Summary of the Invention [Problem to be solved by the invention]

[0004] However, such busbar module cases and busbar modules are required to properly handle water droplets, such as by discharging them from busbar cavities in busbar accommodating sections, when condensation occurs on the busbars. There is room for further improvement in busbar module cases and busbar modules with regard to handling of water droplets accumulated in the busbar cavities.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide a busbar module case and a busbar module that can properly handle water droplets that accumulate in the busbar cavity. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the busbar module case of the present invention houses busbars connected to the electrodes of battery cells in a plurality of battery cells arranged side by side, and includes a busbar cavity having side walls erected around the edge of the busbar, the side walls being provided with drainage holes connecting the inside and outside of the busbar cavity, and the edges of the drainage holes including tapered guide portions that slope from the inside to the outside of the busbar cavity so as to reduce the cross-sectional area of ​​the drainage holes.

[0007] In order to achieve the above-mentioned object, the busbar module of the present invention comprises: a busbar connected to an electrode of a battery cell in a plurality of battery cells arranged side by side; wiring material electrically connected to the busbar; a busbar cavity that accommodates the busbar and has side walls that stand upright around the edge of the busbar, the side walls being provided with drainage holes that connect the inside and outside of the busbar cavity, and a busbar module case in which the edge of the drainage hole includes a tapered guide portion that slopes from the inside to the outside of the busbar cavity so as to reduce the cross-sectional area of ​​the drainage hole. [Effects of the Invention]

[0008] The bus bar module case and bus bar module according to the present invention have the advantage of being able to properly handle water droplets that accumulate in the bus bar cavity. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view illustrating a busbar module according to an embodiment with its cover open. [Figure 2] FIG. 2 is a perspective view illustrating a state in which the cover of the busbar module according to the embodiment is closed. [Figure 3] FIG. 3 is a perspective view of the busbar module case according to the embodiment, as viewed from the battery cell side. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to these embodiments. Furthermore, the components in the following embodiments include those that are easily replaceable by those skilled in the art, or those that are substantially the same.

[0011] [Embodiment] 1 and 2, a battery module 210 of this embodiment includes a plurality of battery cells 211 and a busbar module 1. The battery module 210 of this embodiment is a component of a battery pack 200. The battery pack 200 may include a plurality of battery modules 210. The battery pack 200 is mounted as a power source in a vehicle such as an electric vehicle or a hybrid electric vehicle, for example.

[0012] In the following description, the direction in which the multiple battery cells 211 are arranged side by side is referred to as the first direction X, and the two directions perpendicular to the first direction X are referred to as the second direction Y and the third direction Z. The third direction Z is a direction perpendicular to the installation surface 211b of the multiple battery cells 211. In the following description, one side of the first direction X will be referred to as one side X1, and the other side will be referred to as the other side X2. Similarly, the second direction Y will be referred to as one side Y1 and the other side Y2, and the third direction Z will be referred to as one side Z1 and the other side Z2. In the following description, the third direction Z will be referred to as the vertical direction, and the one side Z1 will also be referred to as the upper side and the other side Z2 as the lower side.

[0013] The battery cells 211 constitute so-called single cells, and a plurality of them are arranged along the first direction X to form an assembled battery. The surfaces (not shown) of the plurality of battery cells 211 on one side Y1 and the other side Y2 in the second direction Y of the assembled battery are configured as electrode arrangement surfaces 211a (the electrode arrangement surface 211a on the other side Y2 is not shown) on which the electrodes 211n of each battery cell 211 are arranged. The electrode arrangement surfaces 211a are parallel to a plane including the first direction X and the third direction Z. Each battery cell 211 has two electrode arrangement surfaces 211a, one of which has a positive electrode arranged on it, and the other has a negative electrode arranged on it. A busbar module 1 is provided on each of the two electrode arrangement surfaces 211a. The busbar module 1 is formed elongated along the first direction X, but only a portion of the busbar module 1 is shown in FIGS. 1 and 2. FIG. 3 is a perspective view of only the busbar module case 100 included in the busbar module 1, as viewed from the other side Y2 in the second direction Y. FIG.

[0014] The busbar module 1 includes a busbar module case 100, a busbar 2, a wiring material 3, and a voltage detection terminal 4. The busbar module case 100 is integrally formed from an insulating resin material. The busbar module case 100 has a case main body 50 and a cover 40. The cover 40 is provided so as to be able to open and close relative to the case main body 50. The case main body 50 has a locked portion 12 of the locking portion 10, a busbar cavity 20 that accommodates the busbar 2 therein, and a wiring path 30 in which the wiring material 3 is provided. The wiring path 30 includes a main line wiring path 35 in which a main line 3a of the wiring material 3 is provided, and a branch wiring path 36 in which a branch portion 3b of the wiring material 3 is provided. The busbar module case 100 will be described in detail below.

[0015] The busbar 2 connects adjacent electrodes 211n of the battery cells 211 arranged along the first direction X. The busbar 2 is a conductor formed of a conductive metal plate. The busbar 2 is formed in a substantially rectangular shape with the first direction X as its longitudinal direction. The busbar 2 has electrode connection holes 2a that are circular through-holes. The busbar 2 is fixed to the electrodes 211n via the electrode connection holes 2a. The busbar 2 connects, for example, two adjacent battery cells 211 in series. In this case, the busbar 2 connects the positive electrode of one battery cell 211 to the negative electrode of the other battery cell 211. The busbar 2 may also be configured to connect two adjacent battery cells 211 in parallel. In addition, a busbar 2 connected to one electrode 211n may be provided at the end of the busbar module 1. Note that, although the busbar 2 is illustrated as a substantially flat plate in this embodiment, it may have a protrusion following the shape of the beam portion 22 described below so as not to interfere with the beam portion 22.

[0016] The wiring material 3 is, for example, a flat wiring material such as a flexible printed circuit board. When the wiring material 3 is a flexible printed circuit board, the wiring material 3 has a base film, a coverlay, and a conductive layer. The base film and coverlay are flexible insulating resin layers. The conductive layer is sandwiched between the base film and the coverlay for protection. The conductive layer is, for example, a conductive metal foil and has multiple circuit patterns connected to the busbar 2. The wiring material 3 has a trunk 3a arranged along the first direction X and a branch 3b extending from the trunk 3a to one side Z1 in the third direction Z.

[0017] The voltage detection terminal 4 is electrically connected to the bus bar 2 and the branch portion 3b of the wiring material 3. The voltage detection terminal 4 detects the voltage between the electrodes of the bus bar 2, and the voltage of the battery cell 211 is monitored by a monitoring device (not shown) connected to the wiring material 3.

[0018] The busbar cavity 20 in the case body 50 of the busbar module case 100 is formed in a generally frame-like shape with one side Y1 and the other side Y2 in the second direction Y open, and has a side wall 21 erected around the edge 2b that forms the outer periphery of the busbar 2. The side wall 21 is formed as a generally plate-like member erected generally perpendicular to the electrode placement surface 211a, and is formed in a generally elongated rectangular shape with the longitudinal direction in the first direction X so as to surround the busbar 2.

[0019] The side wall 21 includes a plate-like first side wall 21a and a plate-like second side wall 21b extending in the first direction X with their plate surfaces facing the third direction Z. The first side wall 21a is provided on one side Z1 in the third direction Z, and the second side wall 21b is provided on the other side Z2. The side wall 21 also includes a plate-like third side wall 21c and a plate-like fourth side wall 21d extending in the third direction Z with their plate surfaces facing the first direction X. The third side wall 21c is provided on one side X1 in the first direction X, and the fourth side wall 21d is provided on the other side X2. The third side wall 21c includes an upper third side wall 21c1 on one side Z1 in the third direction Z and a lower third side wall 21c2 on the other side Z2. The fourth side wall 21d is connected to the first side wall 21a and the second side wall 21b at approximately right angles. The first side wall 21a is connected to the upper third side wall 21c1 at a substantially right angle, and the second side wall 21b is connected to the lower third side wall 21c2 at a substantially right angle.

[0020] The upper third side wall 21c1 is located closer to one side X1 in the first direction X than the lower third side wall 21c2. Therefore, the upper third side wall 21c1 and the lower third side wall 21c2 are spaced apart in the first direction X. The portion where the upper third side wall 21c1 and the lower third side wall 21c2 are spaced apart is defined as a branch wiring path 36 of the wiring path 30 in which the branch portion 3b of the wiring material 3 is routed. An end portion of the upper third side wall 21c1 on the other side Z2 in the third direction Z and an end portion of the lower third side wall 21c2 on one side Z1 overlap when viewed from the first direction X.

[0021] A voltage detection terminal 4 is disposed on one side Z1 of the lower third side wall 21c2 in the third direction Z and on the other side X2 of the upper third side wall 21c1 in the first direction X. The branch portion 3b of the wiring material 3 is electrically connected to the voltage detection terminal 4. Furthermore, a locking portion 12, to which a locking protrusion 11 of a cover 40 (described later) is locked, is provided on the outer surface of the first side wall 21a on the one side Z1 of the third direction Z. The locking portion 12 is formed in the shape of a through hole. Furthermore, a beam portion 22 is provided in a substantially central portion in the first direction X inside the busbar cavity 20, extending from the first side wall 21a to the second side wall 21b. The cross section of the beam portion 22 parallel to a plane including the first direction X and the second direction Y is formed in a substantially U-shape. The opening side of the substantially U-shape of the beam portion 22 faces the other side Y2 in the second direction Y. In addition, a plurality of bus bar locking portions 29 are provided on the side wall 21. Each bus bar locking portion 29 is formed in the shape of a leaf spring that is given elasticity by slits formed on both sides. The bus bar locking portions 29 can fix the bus bar 2 accommodated in the bus bar cavity 20.

[0022] As shown in FIGS. 1 and 4 , the main wiring path 35 of the wiring path 30 in the busbar module case 100 is provided on the other side Z2 in the third direction Z of the second side wall 21b of the busbar cavity 20 (here, on the vertically lower side of the second side wall 21b when the busbar module 1 is installed on the plurality of battery cells 211 (hereinafter, sometimes simply referred to as the “installed state”)). The wiring path 30 has a wall 31 extending outside the side wall 21 of the busbar cavity 20. In this embodiment, the wall 31 extends from the other side Z2 in the third direction Z, which is the outer surface of the second side wall 21b, to the other side Z2, and is formed in a generally plate-like shape with the plate surface facing the second direction Y. A bottom plate 32 is provided at a lower end, which is the end of the other side Z2 in the third direction Z, of the wall 31 so as to protrude from the lower end toward one side Y1 in the second direction Y. The bottom plate 32 is provided with its plate surface facing the third direction Z. The main wiring path 35 of the wiring path 30 is formed by the outer surface (the surface on the other side Z2 in the third direction Z) of the second side wall 21b, the surface on one side Y1 in the second direction Y of the wall 31, and the upper surface (the surface on the one side Z1 in the third direction Z) of the bottom plate 32. A main wire 3a of the wiring material 3 is routed in the main wiring path 35. The main wiring path 35 is formed long in the first direction X.

[0023] As shown in FIG. 1 , a substantially plate-shaped cover 40 is provided on the other side Z2 of the main wiring path 35 of the wiring path 30 in the third direction Z. The cover 40 is connected to the wiring path 30 via a hinge portion 45. The hinge portion 45 is formed in a thin plate shape and is flexible. The cover 40 includes a main line protection portion 41 that covers the main wiring path 35 and a branch protection portion 42 that covers the branch wiring path 36. The hinge portion 45 connects the main line protection portion 41 to the bottom plate 32 of the wiring path 30. A voltage detection terminal protection portion 42a that protrudes toward the other side X2 in the first direction X is formed at the tip of the branch protection portion 42. The voltage detection terminal protection portion 42a covers the voltage detection terminal 4, and in this case, mainly covers the portion of the voltage detection terminal 4 where a potted chip fuse is disposed. The voltage detection terminal protection portion 42a is provided with a locking projection 11 that projects to one side Y1 in the second direction Y when the cover 40 is open.

[0024] As shown in Figure 2, when the cover 40 is closed, the main line protection portion 41 covers the main line 3a of the wiring material 3, and the branch protection portion 42 covers the branch portion 3b of the wiring material 3. In addition, the voltage detection terminal protection portion 42a of the branch protection portion 42 covers the main portion of the voltage detection terminal 4. The cover 40 is locked in the closed state by inserting the locking protrusion 11 into the locked portion 12. The locking portion 10 is composed of the locking protrusion 11 and the locked portion 12. The locking portion 10 locks when the cover 40 is covering the wiring material 3 (wiring path 30).

[0025] As shown in FIGS. 3 and 4 , a plurality of drainage holes 25 are provided in the second side wall 21b of the side wall 21. Each drainage hole 25 is provided in the second side wall 21b, which is the side wall 21 on the installation surface 211b side of the plurality of battery cells 211. That is, each drainage hole 25 is provided in the second side wall 21b of the side wall 21, which is located vertically lower in the installed state. At this time, the busbar 2 is attached with its plate surface facing the second direction Y. In each busbar cavity 20, two drainage holes 25 are provided: one on one side X1 in the first direction X of the beam portion 22 of the busbar cavity 20 and one on the other side X2. That is, the drainage holes 25 are arranged corresponding to the electrodes 211n. Each drainage hole 25 is a hole that penetrates the second side wall 21b along the third direction Z to communicate the inside and outside of the busbar cavity 20. Each drainage hole 25 is formed in a generally elongated rectangular shape with its longitudinal direction in the first direction X. Each drainage hole 25 is open on the other side Y2 in the second direction Y. In the installed state, each drainage hole 25 is provided closer to the battery cell 211 (the other side Y2 in the second direction Y) than the wall 31.

[0026] Tapered guide portions 26a, 26b are provided on the inner edge 26 of each drainage hole 25 of the busbar cavity 20. The tapered guide portions 26a, 26b are inclined so as to reduce the cross-sectional area of ​​the drainage hole 25 (the cross-sectional area of ​​the cross section of the drainage hole 25 parallel to a plane including the first direction X and the second direction Y) from the inside to the outside of the busbar cavity 20. Here, the wall 31 of the wiring passage 30 is provided on the long side 25a of the substantially rectangular shape of each drainage hole 25 (see FIG. 4 in particular). In other words, the wall 31 is provided along the long side of the drainage hole 25. In addition, ribs 27 are provided on two short side sides 25b of the substantially rectangular shape of the edge 26 of the drainage hole 25, respectively, extending from the tapered guide portions 26b of the edge 26 of the short side 25b to the outside of the busbar cavity 20. The rib 27 is provided closer to the battery cell 211 (the other side Y2 in the second direction Y) than the wall 31. The rib 27 is formed in a generally plate shape with its plate surface facing in the first direction X. An end of the rib 27 on one side Y1 in the second direction Y is connected to a surface of the wall 31 on the other side Y2 (the surface on the battery cell 211 side). The inclined surface of the tapered guide portion 26a is connected to the surface of the wall 31 on the battery cell 211 side. The inclined surface of the tapered guide portion 26b is connected to a surface 27a of the rib 27 on the drainage hole 25 side.

[0027] The drainage holes 25 are formed to allow water droplets generated by condensation or the like in the busbar cavity 20 to be discharged from the inside to the outside of the busbar cavity 20. Some of the water droplets adhering to the surface of the busbar 2 on one side Y1 in the second direction Y are discharged from the inside to the outside of the busbar cavity 20 due to their own weight, as shown by the flow path S1 indicated by the dashed line in FIGS. 2 and 4 . Specifically, the water droplets that have condensed and adhered to the busbar 2 fall onto the inner surface of the second side wall 21b (the upper surface of the second side wall 21b), and then flow down the surface 27a of the rib 27 on the drainage hole 25 side to the outside of the busbar cavity 20. The water droplets on the surface of the busbar 2 directly above the drainage holes 25 fall directly to the outside of the busbar cavity 20 through the drainage holes 25, as shown by the flow path S2 indicated by the dashed line. Furthermore, some of the water droplets discharged from the drain holes 25 are discharged to the outside of the busbar cavity 20 via the ribs 27 and the tapered guide portions 26a on the long sides, and then fall down the surface of the wall 31 on the battery cell 211 side.

[0028] The busbar module case 100 described above accommodates the busbar 2 connected to the electrodes 211n of the battery cells 211 arranged side by side. The busbar cavity 20 has a sidewall 21 extending upright around the edge 2b of the busbar 2, and the sidewall 21 is provided with a drainage hole 25 connecting the inside and outside of the busbar cavity 20. The busbar module 1 includes the busbar 2, the wiring material 3, and the busbar module case 100. As a result, even if condensation occurs on the busbar 2 and water droplets form on the surface of the busbar 2, the water droplets do not accumulate on the upper surface of the second sidewall 21b, but can be discharged through the drainage hole 25. This allows for proper disposal of water droplets that accumulate in the busbar cavity 20. Edge 26 of drain hole 25 includes tapered guide portions 26a, 26b that are inclined so as to reduce the cross-sectional area of ​​drain hole 25 from the inside to the outside of busbar cavity 20. As a result, water droplets inside busbar cavity 20 are smoothly guided to drain hole 25 by inclined tapered guide portions 26a, 26b.

[0029] In addition, busbar cavity 20 has ribs 27 extending from edges 26 of drainage holes 25 to the outside of busbar cavity 20. This prevents water droplets discharged from drainage holes 25 from accumulating on the underside of second side wall 21b, and allows the water to be properly discharged to the outside of busbar cavity 20 via ribs 27.

[0030] The busbar cavity 20 further includes a wall 31 that extends from the second side wall 21b of the side wall 21 to the outside of the busbar cavity 20, and the rib 27 is provided on the battery cell 211 side of the wall 31 and is connected to the wall 31. This allows water droplets discharged from the drain holes 25 to fall downward along the surface of the wall 31 facing the battery cell 211, preventing the water droplets from coming into contact with the battery cell 211.

[0031] Furthermore, the drainage holes 25 are formed in an elongated rectangular shape, the walls 31 are provided on the long sides 25a of the drainage holes 25, and the ribs 27 are provided on the short sides 25b of the drainage holes 25. This eliminates the need to drill holes in the walls 31 when forming the drainage holes 25, walls 31, and ribs 27 by injection molding, allowing for satisfactory injection molding. Furthermore, because the drainage holes 25 are located closer to the battery cells 211 than the walls 31, water droplets that collect on the upper surface of the second side plate 21b can be reliably guided to the surface of the wall 31 facing the battery cells 211.

[0032] Additionally, the second side wall 21b of the side wall 21 where the drainage holes 25 are provided is located closer to the installation surface 211b of the plurality of battery cells 211 than the busbar 2. In other words, the drainage holes 25 are provided in the second side wall 21b of the side wall 21 that forms the busbar cavity 20, which is located vertically lower in the installed state. This allows water droplets to be discharged from the drainage holes 25 by their own weight.

[0033] The bus bar module case and the bus bar module according to the above-described embodiment of the present invention are not limited to the above-described embodiment, and various modifications are possible within the scope of the claims.

[0034] In the above description, the rib 27 is provided so as to be connected to the wall 31, but the rib 27 may be provided at a distance from the wall 31. The drain hole 25 is not limited to a substantially rectangular shape, and any appropriate shape may be adopted. The tapered guide portions 26a, 26b are provided over the entire edge 26 of the drain hole 25, but they may be provided on only a part of the edge 26. The wiring material 3 may be a flexible printed circuit board, a flexible flat cable, or an electric wire.

[0035] The bus bar module case and bus bar module according to this embodiment may be configured by appropriately combining the components of the embodiments and modified examples described above. [Explanation of symbols]

[0036] 1: Busbar module 2: Bus bar 2b: Edge 3: Routing material 20: Busbar cavity 21: Side wall 25: Drain hole 25a: Long side 25b: Short side 26: Edge 26a, 26b: Tapered guide section 27: Rib 31: Wall 100: Busbar module case 211: Battery cell 211b: Installation surface 211n: Electrode

Claims

1. a bus bar cavity that houses a bus bar connected to an electrode of a plurality of battery cells arranged side by side, the bus bar cavity having a side wall extending upright around an edge of the bus bar; The side wall is provided with a drain hole communicating the inside and outside of the bus bar cavity, an edge portion of the drain hole includes a tapered guide portion that is inclined from the inside to the outside of the bus bar cavity so as to reduce a cross-sectional area of ​​the drain hole; Busbar module case.

2. The bus bar cavity has a rib extending from the edge of the drain hole to the outside of the bus bar cavity. The busbar module case according to claim 1 .

3. a wall extending from the side wall to an outside of the bus bar cavity; the rib is provided on the wall on the battery cell side and is connected to the wall; The busbar module case according to claim 2 .

4. The drain hole is formed in an elongated rectangular shape, The wall is provided on a long side of the rectangular drain hole, The rib is provided on a short side of the rectangular drain hole. The busbar module case according to claim 3 .

5. the side wall is located closer to an installation surface of the plurality of battery cells than the bus bar; The busbar module case according to any one of claims 1 to 4.

6. a bus bar connected to an electrode of a plurality of battery cells arranged side by side; a wiring material electrically connected to the bus bar; a busbar module case including a busbar cavity that accommodates the busbar and has a sidewall that stands around an edge of the busbar, the sidewall having a drain hole that communicates between the inside and outside of the busbar cavity, and an edge of the drain hole including a tapered guide portion that is inclined from the inside to the outside of the busbar cavity so as to reduce a cross-sectional area of ​​the drain hole; Equipped with Busbar module.

Images