Busbar module

Abstract

To provide a bus bar module which can suppress looseness of a bus bar and can downsize a case.SOLUTION: A bus bar module 1 is attached to a battery cell module and forms an in-vehicle battery with the battery cell module. The bus bar module 1 includes: a case 2 with a plurality of bus bar storage parts 23 and an FPC storage part 25; a plurality of bus bars 3 stored in the bus bar storage parts 23; an FPC 5 stored in the FPC storage part 25; and an FPC cover 6 attached to the upper surface side of the case 2. The FPC cover 6 includes: a cover body part 61 covering the FPC 5; and a bus bar pressing part 63 for pressing the upper surface of the bus bar 3 and locating the bus bar 3 between the bus bar pressing part and a bus bar supporting unit 21.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a bus bar module attached to a battery cell assembly.

Background Art

[0002] As an example of a battery mounted on a hybrid vehicle or an electric vehicle, one including a battery cell assembly in which a plurality of battery cells are stacked and a bus bar module attached to the battery cell assembly is known (see, for example, Patent Document 1).

[0003] FIG. 9 is a diagram showing a conventional bus bar module. The bus bar module 501 shown in FIG. 9 includes a plurality of bus bars 503, an FPC, a plurality of terminals 504 connected to the FPC and overlapping each bus bar 503, a case 502 accommodating these components, and an FPC cover 506 covering the FPC.

[0004] The bus bar 503 connects electrodes of adjacent battery cells of the battery cell assembly. In the battery cell assembly, a plurality of battery cells are connected in series by the plurality of bus bars 503.

[0005] The FPC connects a battery control unit to each battery cell via the bus bar 503 and the terminal 504 in order to detect the voltage of each battery cell. In addition to the terminal 504, a temperature sensor for detecting the temperature of the battery cell and the like are also connected to the FPC.

[0006] The case 502 is made of an insulating synthetic resin. The case 502 has an FPC accommodating portion and a plurality of bus bar accommodating portions 523. Each bus bar accommodating portion 523 includes a bus bar support portion 521 located on the lower surface side of the bus bar 503, a bus bar surrounding portion 520 surrounding the bus bar 503, and a claw portion 529 formed on the bus bar surrounding portion 520 and fixing the bus bar 503. The claw portion 529 includes a U-shaped slit formed in the bus bar surrounding portion 520 and a protrusion protruding from a portion between the slits.

[0007] The bus bar 503 is assembled into the bus bar housing 523 by being inserted from above. When the bus bar 503 is inserted, the claw portion 529 is pushed by the bus bar 503 and rotates (bends) in the direction indicated by the arrow in Figure 9, and returns to its original position after the bus bar 503 has passed, thereby fixing the bus bar 503 in place. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2022-173610 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The busbar module 501 described above required a gap S between the busbar support 521 and the busbar 503, taking into account the rotational trajectory of the claw portion 529. If there was no gap, the claw portion 529 would rotate in the direction indicated by the arrow in Figure 9 and would not be able to return to its original position, making it impossible to fix the busbar 503. Thus, the busbar module 501 had the problem of the busbar 503 rattling due to the need for the aforementioned gap S and space to rotate the claw portion 529 in the direction indicated by the arrow in Figure 9. In addition, the busbar module 501 required the aforementioned gap S and space to rotate the claw portion 529 in the direction indicated by the arrow in Figure 9, which resulted in the case 502 becoming larger.

[0010] Therefore, the present invention aims to provide a busbar module that can suppress busbar rattle and allows for miniaturization of the case. [Means for solving the problem]

[0011] The present invention relates to a busbar housing And the FPC housing section, A case having a busbar housed in the busbar housing section, The FPC housed in the FPC housing section,The case comprises a cover assembled to the upper side of the case, the busbar housing section having a busbar support section located on the lower side of the busbar, and a busbar surrounding section surrounding the busbar, the cover being, A cover body portion located on the upper surface side of the FPC and positioning the FPC between itself and the FPC housing portion, A busbar pressing part that presses the upper surface of the busbar to position the busbar between itself and the busbar support part. and, Having The tip of the busbar pressing part is curved in a hook shape. This is a busbar module characterized by the following features. [Effects of the Invention]

[0012] According to the present invention, the cover has a busbar pressing portion that presses against the upper surface of the busbar to position the busbar between itself and the busbar support portion, thereby suppressing rattling of the busbar and enabling miniaturization of the case. [Brief explanation of the drawing]

[0013] [Figure 1] This figure shows a busbar module according to one embodiment of the present invention. [Figure 2] This is an enlarged view of the main part of the busbar module shown in Figure 1. [Figure 3] This is a cross-sectional view along line AA in Figure 1. [Figure 4] This is a cross-sectional view along line BB in Figure 1. [Figure 5] This figure shows the FPC cover removed from Figure 2. [Figure 6] Figure 5 is a top view of the busbar module. [Figure 7] This diagram shows the FPC cover inverted (upside down) as shown in Figure 2. [Figure 8] This figure shows only the bass bar from Figure 2. [Figure 9] This diagram shows a conventional busbar module. [Modes for carrying out the invention]

[0014] A "busbar module" according to one embodiment of the present invention will be described with reference to Figures 1 to 8.

[0015] The bus bar module 1 shown in Figs. 1, 2 and 5 is attached to a battery cell assembly formed by stacking a plurality of battery cells, and constitutes a vehicle-mounted battery together with the battery cell assembly.

[0016] In this specification, with respect to the bus bar module 1, the side on which the battery cell assembly is disposed is defined as the lower side, and the side opposite to the battery cell assembly is defined as the upper side. These upper and lower directions do not need to coincide with the actual vertical direction when the battery is mounted on a vehicle.

[0017] The bus bar module 1 includes a plurality of bus bars 3, an FPC (Flexible Printed Circuit) 5, a plurality of terminals 4, a plurality of temperature sensors (not shown), a case 2 accommodating these components, and an FPC cover 6.

[0018] The bus bar 3 connects electrodes of adjacent battery cells in the battery cell assembly. In the battery cell assembly, the plurality of battery cells are connected in series by the plurality of bus bars 3. The bus bar 3 is obtained by subjecting a metal plate to press working or the like, and as shown in Fig. 8, includes a pair of electrode connection portions 31 spaced apart from each other, and a connection portion 33 connecting the pair of electrode connection portions 31 to each other.

[0019] Each electrode connection portion 31 is formed with a hole 30 through which an electrode of a battery cell passes. The connection portion 33 includes a pair of vertical portions 34 respectively rising from one side of the pair of electrode connection portions 31, and a horizontal portion 35 connecting the pair of vertical portions 34 to each other. A boundary between the pair of vertical portions 34 and the horizontal portion 35 is bent at a right angle.

[0020] As shown in Fig. 5, the FPC 5 includes a pair of trunk portions 51 extending parallel to each other, a first connection portion 53 connecting the pair of trunk portions 51 to each other, a plurality of branch portions 54 disposed below the trunk portions 51, and a plurality of second connection portions 52 connecting each branch portion 54 and the trunk portion 51.

[0021] Although not shown in the diagram, the FPC5 has multiple third connection sections that connect multiple temperature sensors to the main line section 51. The multiple temperature sensors contact predetermined battery cells to detect the temperature of those battery cells. In this example, three temperature sensors are provided, and they contact battery cells located at one end, the other end, and the center of the battery cell assembly.

[0022] A pair of main lines 51 extend in the longitudinal direction of the case 2. The longitudinal direction of the case 2 and the longitudinal direction of the main lines 51 coincide with the direction in which the battery cells of the battery cell assembly are stacked. Terminals 4 are connected to each branch 54. Branch 54 and terminals 4 are provided for each battery cell. The second connecting section 52 is bent into a U shape.

[0023] The FPC5 is connected to a control unit located on one end of the vehicle battery. The FPC5 has wiring patterns formed on it that connect the control unit to each terminal 4, and wiring patterns that connect the control unit to each temperature sensor. In this example, the busbar module 1 detects the voltage of each battery cell, the total voltage, and the temperature of a predetermined battery cell, and the control unit monitors these voltages and temperatures.

[0024] Multiple terminals 4 are formed in a plate shape, and as shown in Figures 4 and 5, one side is superimposed on the branch portion 54 of the FPC 5 and electrically and mechanically connected, while the other side is superimposed on the horizontal portion 35 of the busbar 3 and electrically and mechanically connected.

[0025] Case 2 is made of an insulating synthetic resin. Case 2 integrally includes an FPC housing section 25, a plurality of busbar housing sections 23, and a connecting section 24 that connects adjacent busbar housing sections 23 to each other.

[0026] The FPC housing section 25 is the part that houses the FPC 5 described above. The FPC housing section 25 is formed in the center of the width direction of the case 2 and over the entire length direction of the case 2.

[0027] The busbar housing section 23 is the part that houses the busbars 3 described above. One busbar 3 is housed in one busbar housing section 23. Multiple busbar housing sections 23 are formed at both ends in the width direction of the case 2 and on both sides of the FPC housing section 25. In addition, the multiple busbar housing sections 23 are arranged in the longitudinal direction of the case 2, and adjacent busbar housing sections 23 are connected to each other by connecting sections 24.

[0028] As shown in Figures 2 and 3, each busbar housing section 23 includes a busbar support section 21 located on the lower side of the horizontal section 35 of the busbar 3, a busbar enclosure section 20 surrounding the entire busbar 3, and a partition wall 22 located between the pair of electrode connection sections 31 of the busbar 3.

[0029] The busbar support section 21 is connected to the FPC housing section 25 and the busbar enclosure section 20. The lower side of the pair of electrode connection sections 31 is open, without a wall or other structure like the one on the busbar support section 21. The electrodes of the battery cell are passed through this opening and the holes 30 in the electrode connection sections 31, and nuts are fastened to them.

[0030] The busbar enclosure portion 20 is formed in a frame shape that surrounds the entire busbar 3, but a notch portion 28 is formed at the boundary portion with the FPC housing portion 25 to allow the terminal 4 to pass through. In addition, a locking projection 27 is formed at the boundary portion of the busbar enclosure portion 20 with the FPC housing portion 25, protruding towards the FPC housing portion 25.

[0031] The busbar 3 is inserted into the busbar housing 23 from above (opposite the battery cell assembly). Once inserted, the busbar 3 is surrounded by the busbar enclosure 20 and supported by the busbar support 21 on its underside, thus restricting the planar movement and downward movement of the electrode connection portion 31. On the other hand, since the busbar housing 23 does not have a structure to fix the busbar 3 (such as the claw portion 529 in Figure 9), upward movement is possible when the FPC cover 6 is not attached to the case 2. This upward movement is restricted by the busbar pressing portion 63 provided on the FPC cover 6.

[0032] The FPC cover 6 is made of an insulating synthetic resin. The FPC cover 6 is assembled to the upper side of the case 2. The FPC cover 6 integrally includes a cover body portion 61 located on the upper side of the FPC 5 and positioning the FPC 5 between it and the FPC housing portion 25, a plurality of locking portions 62, and a plurality of busbar pressing portions 63.

[0033] As shown in Figure 1, the cover body 61 is formed in the shape of an elongated plate. As shown in Figures 4 and 7, the multiple locking portions 62 hang down in a plate shape from the widthwise end of the cover body 61 and have locking holes 62a. Each locking portion 62 is locked onto each locking projection 27 formed on the case 2. In this way, the FPC cover 6 is assembled to the case 2.

[0034] Each of the multiple busbar pressing portions 63 has an extended portion 63a extending outward from the widthwise end of the cover body portion 61, a plate portion 63b hanging down from the end of the extended portion 63a that is away from the cover body portion 61, and a hook-shaped curved tip portion 63c connected to the lower end of the plate portion 63b.

[0035] The busbar pressing portion 63 has a tip portion 63c that presses against the upper surface of the horizontal portion 35 of the busbar 3, positioning the horizontal portion 35 between itself and the busbar support portion 21. This restricts the upward movement, i.e., lifting, of the busbar 3.

[0036] Furthermore, the aforementioned locking portion 62 is formed near the busbar pressing portion 63 and faces the plate portion 63b. For this reason, an opening 64 is formed in the extended portion 63a, which is necessary for mold-forming the locking portion 62. Note that the number of locking portions 62 is fewer than the number of busbar pressing portions 63, and some busbar pressing portions 63 do not have openings 64 formed therein.

[0037] The busbar module 1 described above eliminates the claw shape that was present on the case of conventional busbar modules, and instead of fixing the busbar 3 and case 2 with claws, it is fixed by pressing down with an FPC cover 6. Specifically, a busbar pressing part 63 is provided on the FPC cover 6, and the flexibility of the resin is used to press down on and fix the busbar 3 from above.

[0038] This type of busbar module 1 eliminates the gap between the case and the busbar (gap S in Figure 9) that was required for conventional claw-type fixing, allowing the busbar 3 to be fixed without rattle. Furthermore, the flexibility of the resin exerts a force that presses the busbar 3 against the busbar support part 21, ensuring that even if a gap occurs due to tolerances between the busbar 3 and the case 2, it can be fixed without rattle. This improves the ease of assembly into the battery cell assembly. In addition, the elimination of the gap between the case 2 and the busbar 3 allows the height of the busbar housing part 23 to be lower than in conventional products, and the space required for the claw to rotate is also eliminated, allowing for miniaturization of both the case 2 and the busbar module 1. Moreover, eliminating the claw shape leads to a cost reduction for the case 2. Furthermore, eliminating the claw shape increases the strength of each busbar housing part 23.

[0039] The embodiments described above merely represent typical forms of the present invention, and the present invention is not limited to these embodiments. That is, it can be implemented with various modifications without departing from the core principles of the present invention. As long as such modifications still possess the configuration of the present invention, they are of course included within the scope of the present invention. [Explanation of Symbols]

[0040] 1 Busbar Module 2 cases 3 Busba 4 terminals 5 FPC 6 FPC cover (cover) 20. Siege of Basba 21 Bass support section 23 Bus bay area 25 FPC housing section 27 Locking protrusion 61 Cover body 62 Locking part 63 Busbar pressing part

Claims

[Claim 1] A case having a busbar housing section and an FPC housing section, The busbar housed in the aforementioned busbar housing section, The FPC housed in the FPC housing section, The case comprises a cover attached to the upper side of the case, The busbar housing section comprises a busbar support section located on the lower side of the busbar and a busbar enclosure section surrounding the busbar. The cover has a cover body portion located on the upper surface side of the FPC and positioning the FPC between itself and the FPC housing portion, and a busbar pressing portion that presses the upper surface of the busbar and positions the busbar between itself and the busbar support portion. The tip of the busbar pressing part is curved in a hook shape. A busbar module characterized by the following features.

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