Bus bar 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 busbar module that is attached to a battery cell assembly. [Background technology]

[0002] One known example of a battery installed in a hybrid vehicle or an electric vehicle includes a battery cell assembly in which multiple battery cells are stacked, and a busbar module attached to the battery cell assembly (see, for example, Patent Document 1).

[0003] Fig. 9 is a diagram showing a conventional bus bar module. 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 stacked on each bus bar 503, case 502 accommodating these, and FPC cover 506 covering the FPC.

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

[0005] In order to detect the voltage of each battery cell, the FPC connects the battery control unit and each battery cell via bus bars 503 and terminals 504. In addition to the terminals 504, a temperature sensor that detects the temperature of the battery cell is also connected to the FPC.

[0006] Case 502 is made of insulating synthetic resin. Case 502 has an FPC accommodating section and multiple bus bar accommodating sections 523. Each bus bar accommodating section 523 has a bus bar support section 521 located on the underside of bus bar 503, a bus bar enclosing section 520 that surrounds bus bar 503, and claw sections 529 formed in bus bar enclosing section 520 and that secure bus bar 503. Claw sections 529 are made up of U-shaped slits formed in bus bar enclosing section 520 and protrusions that protrude from the portions between the slits.

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

[0008] [Patent Document 1] Japanese Patent Publication No. 2022-173610 Summary of the Invention [Problem to be solved by the invention]

[0009] In the above-described bus bar module 501, it was necessary to provide a gap S between the bus bar support portion 521 and the bus bar 503 in consideration of the rotation 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 FIG. 9 and not return to its original position, and the bus bar 503 would not be fixed. As described above, the bus bar module 501 had to provide the gap S, which caused a problem of the bus bar 503 rattling. Furthermore, the bus bar module 501 required the above-described gap S and a space for rotating the claw portion 529 in the direction indicated by the arrow in FIG. 9, which resulted in a problem of the case 502 becoming larger.

[0010] Therefore, an object of the present invention is to provide a bus bar module that can suppress rattle of the bus bar and that allows the case to be made smaller. [Means for solving the problem]

[0011] The present invention provides a busbar module comprising: a case having a busbar accommodating portion; a busbar accommodated in the busbar accommodating portion; and a cover attached to the upper surface side of the case, wherein the busbar accommodating portion has a busbar support portion located on the lower surface side of the busbar and a busbar enclosing portion surrounding the busbar, and the cover has a busbar pressing portion that presses against the upper surface of the busbar to position the busbar between the cover and the busbar support portion. [Effects of the Invention]

[0012] According to the present invention, the cover has a bus bar pressing portion that presses the upper surface of the bus bar and positions the bus bar between it and the bus bar support portion, thereby suppressing rattling of the bus bar and enabling the case to be made smaller. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram showing a busbar module according to an embodiment of the present invention; [Figure 2] 2 is an enlarged view of a main part of the busbar module of FIG. 1. [Figure 3] FIG. 2 is a cross-sectional view taken along the line AA in FIG. [Figure 4] FIG. 2 is a cross-sectional view taken along line BB in FIG. [Figure 5] FIG. 3 is a diagram showing the state in which the FPC cover in FIG. 2 is removed. [Figure 6] FIG. 6 is a top view of the busbar module of FIG. 5. [Figure 7] FIG. 3 is a diagram showing the FPC cover of FIG. 2 turned upside down. [Figure 8] FIG. 3 is a diagram showing only the bus bar of FIG. 2. [Figure 9] FIG. 10 is a diagram illustrating a conventional bus bar module. DETAILED DESCRIPTION OF THE INVENTION

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

[0015] The busbar module 1 shown in FIGS. 1, 2 and 5 is attached to a battery cell assembly in which a plurality of battery cells are stacked, and together with the battery cell assembly constitutes an on-board battery.

[0016] In this specification, the side on which the battery cell assemblies are arranged is defined as the lower side, and the side opposite the battery cell assemblies is defined as the upper side, with respect to the busbar module 1. These upper and lower sides do not have to coincide with the actual up and down directions when mounted on a vehicle.

[0017] The busbar module 1 includes a plurality of busbars 3, FPCs (Flexible Printed Circuits) 5, a plurality of terminals 4, a plurality of temperature sensors (not shown), a case 2 that houses these, and an FPC cover 6.

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

[0019] Each electrode connection portion 31 has a hole 30 through which an electrode of a battery cell is passed. The linking portion 33 has a pair of vertical portions 34 that rise from one side of each of the pair of electrode connection portions 31, and a horizontal portion 35 that connects the pair of vertical portions 34. The boundary between the pair of vertical portions 34 and the horizontal portion 35 is bent at a right angle.

[0020] As shown in Figure 5, the FPC 5 has a pair of trunk sections 51 extending parallel to each other, a first connecting section 53 connecting the pair of trunk sections 51, a plurality of branch sections 54 arranged below the trunk section 51, and a plurality of second connecting sections 52 connecting each branch section 54 to the trunk section 51.

[0021] Although not shown, the FPC 5 also has a plurality of third connecting portions that connect the plurality of temperature sensors to the trunk portion 51. The plurality of temperature sensors contact predetermined battery cells to detect the temperatures of the battery cells. In this example, three temperature sensors are provided, and these contact the battery cells arranged at one end, the other end, and the center of the battery cell assembly.

[0022] The pair of trunk portions 51 extend in the longitudinal direction of the case 2. The longitudinal direction of the case 2 and the longitudinal direction of the trunk portions 51 coincide with the direction in which the battery cells of the battery cell assembly are stacked. A terminal 4 is connected to each branch portion 54. A branch portion 54 and a terminal 4 are provided for each battery cell. The second connecting portion 52 is bent into a U-shape.

[0023] The FPC 5 is connected to a control unit arranged on one end of the vehicle battery. The FPC 5 is formed with wiring patterns that connect the control unit to each terminal 4 and wiring patterns that connect the control unit to each temperature sensor. The busbar module 1 of this example detects the voltage of each battery cell, the total voltage, and the temperature of a specific battery cell, and the control unit monitors these voltages and temperatures.

[0024] The terminals 4 are formed in a plate shape, and as shown in Figures 4 and 5, one side of each terminal is placed on the branch portion 54 of the FPC 5 and electrically and mechanically connected thereto, and the other side is placed on the horizontal portion 35 of the bus bar 3 and electrically and mechanically connected thereto.

[0025] Case 2 is made of insulating synthetic resin and integrally includes FPC accommodating portion 25, a plurality of bus bar accommodating portions 23, and connecting portions 24 that connect adjacent bus bar accommodating portions 23 to each other.

[0026] The FPC receiving portion 25 is a portion that receives the above-mentioned FPC 5. The FPC receiving portion 25 is formed in the center of the case 2 in the width direction and over the entire area of the case 2 in the longitudinal direction.

[0027] The bus bar accommodating portions 23 are portions that accommodate the above-described bus bars 3. One bus bar 3 is accommodated in one bus bar accommodating portion 23. A plurality of bus bar accommodating portions 23 are formed at both widthwise ends of the case 2 and on both sides of the FPC accommodating portion 25. The plurality of bus bar accommodating portions 23 are also arranged in the longitudinal direction of the case 2, and adjacent bus bar accommodating portions 23 are connected to each other by connecting portions 24.

[0028] As shown in Figures 2 and 3, each busbar accommodating section 23 has a busbar support section 21 located on the underside of the horizontal section 35 of the busbar 3, a busbar enclosing section 20 that surrounds the entire busbar 3, and a partition wall 22 located between a pair of electrode connection sections 31 of the busbar 3.

[0029] The bus bar support portion 21 is connected to the FPC accommodating portion 25 and the bus bar surrounding portion 20. The lower surfaces of the pair of electrode connection portions 31 are open and are not provided with walls of the case 2 like the bus bar support portions 21. The electrodes of the battery cell are passed through these openings and holes 30 in the electrode connection portions 31 and fastened with nuts.

[0030] The bus bar enclosing portion 20 is formed in a frame shape surrounding the entire bus bar 3, and at the boundary with the FPC accommodating portion 25, a notch 28 is formed to allow the terminal 4 to pass through. In addition, at the boundary between the bus bar enclosing portion 20 and the FPC accommodating portion 25, a locking protrusion 27 is formed that protrudes toward the FPC accommodating portion 25.

[0031] The bus bar 3 is inserted into the bus bar accommodating portion 23 from above (the side opposite the battery cell assembly). The inserted bus bar 3 is surrounded by the bus bar enclosing portion 20 and has the bus bar support portion 21 on its underside, restricting the movement of the electrode connection portion 31 in the planar direction and downward. However, the bus bar accommodating portion 23 does not have a structure (such as the tab portion 529 in FIG. 9 ) for fixing the bus bar 3, and therefore upward movement is possible when the FPC cover 6 is not attached to the case 2. This upward movement is restricted by the bus bar pressing portion 63 provided on the FPC cover 6.

[0032] The FPC cover 6 is made of insulating synthetic resin and is attached to the upper surface of the case 2. The FPC cover 6 integrally includes a cover main body 61 located on the upper surface of the FPC 5 to position the FPC 5 between the cover main body 61 and the FPC accommodating portion 25, a plurality of locking portions 62, and a plurality of bus bar pressing portions 63.

[0033] As shown in Fig. 1, the cover main body 61 is formed in the shape of a long, thin plate. As shown in Figs. 4 and 7, the multiple locking portions 62 hang down like plates from the widthwise ends of the cover main body 61 and have locking holes 62a. Each locking portion 62 is locked to a corresponding locking projection 27 formed on the case 2. In this way, the FPC cover 6 is attached to the case 2.

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

[0035] The tip end 63c of the bus bar pressing portion 63 presses the upper surface of the horizontal portion 35 of the bus bar 3, positioning the horizontal portion 35 between the bus bar pressing portion 63 and the bus bar support portion 21. This prevents the bus bar 3 from moving upward, i.e., from floating up.

[0036] The locking portion 62 is formed near the bus bar pressing portion 63 and faces the plate portion 63b. Therefore, the extension portion 63a is formed with an opening 64 required for molding the locking portion 62. The number of locking portions 62 is smaller than the number of bus bar pressing portions 63, and some bus bar pressing portions 63 do not have an opening 64 formed therein.

[0037] The bus bar module 1 described above does not have the claw shape provided on the case of a conventional bus bar module, and the bus bar 3 is fixed to the case 2 not by the claw but by the FPC cover 6. Specifically, a bus bar pressing portion 63 is provided on the FPC cover 6, and the flexibility of the resin is used to press and fix the bus bar 3 from above.

[0038] This busbar module 1 eliminates the gap (gap S in FIG. 9 ) between the case and the busbar, which is required when using conventional claws for fastening, and allows the busbar 3 to be fastened without rattle. Furthermore, the flexibility of the resin creates a force pressing the busbar 3 against the busbar support portion 21, allowing for fastening without rattle even when a gap occurs due to tolerances between the busbar 3 and the case 2. This improves assembly to the battery cell assembly. Furthermore, the elimination of the gap between the case 2 and the busbar 3 allows the busbar accommodating portion 23 to be lower than conventional products, and also eliminates the space required for the claws to rotate, allowing for the miniaturization of the case 2 and busbar module 1. Furthermore, the elimination of the claw shape leads to a reduction in the cost of the case 2. Furthermore, the elimination of the claw shape increases the strength of each busbar accommodating portion 23.

[0039] The above-described embodiment merely shows a typical form of the present invention, and the present invention is not limited to this embodiment. In other words, the present invention can be implemented with various modifications within the scope of the gist of the present invention. As long as such modifications still include the configuration of the present invention, they are of course included in the scope of the present invention. [Explanation of symbols]

[0040] 1 Busbar module 2 cases 3 Bus Bar 4 terminals 5 FPC 6 FPC cover (cover) 20 Bus bar enclosure 21 Bus bar support part 23 Bus bar housing 25 FPC housing section 27 Locking protrusion 61 Cover body 62 Locking part 63 Bus bar pressing part

Claims

1. a case having a bus bar accommodating portion; a bus bar accommodated in the bus bar accommodating portion; a cover attached to the upper surface side of the case, the bus bar accommodating portion includes a bus bar supporting portion located on a lower surface side of the bus bar and a bus bar surrounding portion surrounding the bus bar, The cover has a bus bar pressing portion that presses against an upper surface of the bus bar to position the bus bar between the cover and the bus bar support portion. A busbar module characterized by:

2. The tip of the bus bar pressing portion is curved in a hook shape. The busbar module according to claim 1 .

3. the case has an FPC housing portion, an FPC housed in the FPC housing; The cover has a cover body portion located on the upper surface side of the FPC, and the FPC is positioned between the cover body portion and the FPC receiving portion. The busbar module according to claim 1 .

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