Busbar Module

Abstract

To provide a bus bar module capable of improving followability against a bus bar.SOLUTION: A bus bar module 1 comprises: a plurality of bus bars 2 arranged side by side along a first direction X, and connected to a battery cell; and a plate-like circuit body 3 that includes a plurality of detection wires 71 connected to the bus bar, and has flexibility. The circuit body includes: a trunk line part 30 in which the plurality of detection wires are distributed; and a branch part 31 that is branched from the trunk line part, and in which the detection wire connected to the bus bar is distributed. The branch part includes an extension part 34 which can be extended along a first direction. The extension part includes slits 34a and 34b or a notch, formed in a direction crossing the first direction when viewing the circuit body in a plan. The detection wire of the extension part is distributed along the slit or the notch.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] Conventionally, busbar modules have been used. Patent Document 1 discloses a battery connection module equipped with a flexible circuit board including a main body and a plurality of L-shaped flexible arms extending from the main body. The L-shaped flexible arm in Patent Document 1 includes a first section extending outward from the main body toward the plurality of busbars, a second section connecting to the first section and extending in a direction between the plurality of busbars and the main body, and an end portion positioned at the distal end of the second section and connecting to the corresponding busbar. Patent Document 2 discloses a flexible printed wiring board that is not subjected to tensile force even if the position of an electrical device or the like to be connected is misaligned. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2019-23996 [Patent Document 2] Japanese Patent Application Publication No. 06-140727 Summary of the Invention [Problem to be solved by the invention]

[0004] It is desirable to improve the followability of a bus bar module relative to a bus bar. For example, if the circuit body can be configured to be expandable, the followability when connecting the circuit body to the bus bar can be improved.

[0005] An object of the present invention is to provide a bus bar module that can improve the followability to a bus bar. [Means for solving the problem]

[0006] The busbar module of the present invention comprises a flexible, plate-shaped circuit body having a plurality of bus bars arranged along a first direction and connected to battery cells, and a plurality of detection lines connected to the bus bars, wherein the circuit body has a main line portion in which the plurality of detection lines are arranged, and branch lines branching from the main line portion and in which the detection lines connected to the bus bars are arranged, the branch lines having an expandable portion that can expand and contract along the first direction, the expandable portion having a slit or notch formed in a direction intersecting the first direction when the circuit body is viewed in a plane, and the detection lines of the expandable portion being arranged along the slit or notch. [Effects of the Invention]

[0007] The expandable portion of the busbar module according to the present invention has a slit or notch formed in a direction intersecting the first direction, and can expand and contract along the first direction. The busbar module according to the present invention has an effect of improving the followability to the busbar. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a plan view of a bus bar module according to an embodiment. [Figure 2] FIG. 2 is an enlarged view of the busbar module according to the embodiment. [Figure 3] FIG. 3 is an enlarged view of the bus bar module according to the embodiment. [Figure 4] FIG. 4 is a plan view showing an example of the configuration of the branch portion. [Figure 5] FIG. 5 is a plan view showing an example of the configuration of the branch portion. [Figure 6] FIG. 6 is a plan view showing an example of the configuration of the branch portion. [Figure 7] FIG. 7 is a plan view showing an example of the configuration of the branch portion. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a busbar module according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiment. Furthermore, components in the following embodiments include those that can be easily imagined by a person skilled in the art or those that are substantially the same.

[0010] [Embodiment] An embodiment will be described with reference to Fig. 1 to Fig. 7. The embodiment relates to a busbar module. Fig. 1 is a plan view of the busbar module according to the embodiment, Fig. 2 and Fig. 3 are enlarged views of the busbar module according to the embodiment, and Fig. 4 to Fig. 7 are plan views showing configuration examples of branch portions.

[0011] As shown in Fig. 1, a busbar module 1 of the embodiment includes a plurality of busbars 2, a circuit body 3, a case 4, a thermistor 5, and a connector 6. The busbar module 1 is assembled to a battery module 110 to form a battery pack 100. The battery pack 100 is mounted as a power source in vehicles such as electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs). The battery pack 100 may include a plurality of busbar modules 1 and a plurality of battery modules 110.

[0012] The battery module 110 has a plurality of battery cells 120. The plurality of battery cells 120 are arranged along a first direction X. A bus bar 2 connects electrodes of two adjacent battery cells 120. In the bus bar module 1, for example, the plurality of battery cells 120 are connected in series by the bus bar 2.

[0013] The busbar 2 is formed from a conductive metal plate such as copper or aluminum. The busbar 2 has a connection portion 20 and a terminal portion 21. The connection portion 20 is connected to a voltage detection line. The terminal portion 21 is connected to an electrode of the battery cell 120. The terminal portion 21 is fixed to the electrode by, for example, laser welding.

[0014] The bus bar module 1 has a first bus bar group 2A and a second bus bar group 2B. The first bus bar group 2A and the second bus bar group 2B have a plurality of bus bars 2 arranged along a first direction X. The bus bar 2 of the first bus bar group 2A is fixed to one electrode of the battery cell 120. The bus bar 2 of the second bus bar group 2B is fixed to another electrode of the battery cell 120.

[0015] In the following description, a direction perpendicular to the first direction X when the busbar module 1 is viewed from above is referred to as a "second direction Y." The second direction Y is the width direction of the busbar module 1. A direction perpendicular to both the first direction X and the second direction Y is referred to as a "third direction Z." The third direction Z is the thickness direction of the busbar module 1.

[0016] The circuit body 3 is a plate-like circuit body and is flexible. The circuit body 3 of this embodiment is a flexible printed circuit board (FPC: Flexible Printed Circuits). The circuit body 3 has a trunk portion 30 and multiple branch portions 31. The trunk portion 30 is the main portion of the circuit body 3 and has a rectangular shape in a plan view.

[0017] The circuit body 3 has a plurality of detection wires 7 and a covering portion 8 that covers the detection wires 7. The covering portion 8 is formed, for example, from a flexible resin having insulating properties. The detection wires 7 are formed from a metal foil such as copper foil. The plurality of detection wires 7 include a voltage detection wire 71 and a temperature detection wire 72. The voltage detection wire 71 is a detection wire that is connected to the busbar 2. The temperature detection wire 72 is a detection wire that is connected to the thermistor 5. The plurality of detection wires 7 are routed inside the trunk portion 30 along the first direction X.

[0018] The branch portion 31 is a portion that branches off from the trunk portion 30 and is connected to the bus bar 2. Inside the branch portion 31, one voltage detection line 71 that is connected to the bus bar 2 is routed.

[0019] The thermistor 5 is a detection element that detects the temperature of the battery cell 120. In the illustrated busbar module 1, the thermistors 5 are arranged at both ends in the first direction X. The connector 6 is arranged at the end of the circuit body 3 in the first direction X. A plurality of detection wires 7 are connected to terminals of the connector 6. The plurality of detection wires 7 are connected to a monitoring device via the connector 6. The monitoring device controls the battery pack 100 based on the detected values ​​of voltage and temperature.

[0020] The case 4 houses and holds the bus bars 2 and supports the circuit body 3. The case 4 is molded from, for example, an insulating synthetic resin. The shape of the case 4 in plan view is, for example, rectangular.

[0021] 2 and 3 show a bus bar 2C located at an end of the first bus bar group 2A and a branch portion 31 corresponding to this bus bar 2C. The branch portion 31 of this embodiment is configured to be able to expand and contract along the first direction X. The branch portion 31 has an expandable portion 34 that is able to expand and contract along the first direction X. In the illustrated branch portion 31, the entire branch portion 31 is the expandable portion 34. A voltage detection line 71 connected to the bus bar 2C is routed inside the branch portion 31.

[0022] The branch portion 31 is formed with a plurality of slits 31a directed toward one side Y1 in the second direction Y and a plurality of slits 31b directed toward the other side Y2 in the second direction Y. The plurality of slits 31a and slits 31b are aligned along the first direction X. The slits 31a and slits 31b are alternately arranged along the first direction X. That is, the branch portion 31 is formed into an elongated zigzag shape by the slits 31a and 31b.

[0023] The voltage detection wire 71 is routed along the slits 31a and 31b. That is, the voltage detection wire 71 is routed in a zigzag pattern inside the branch portion 31. The branch portion 31 accommodates the voltage detection wire 71 inside so that the voltage detection wire 71 is not exposed.

[0024] 3, the branch portion 31 is stretched along the first direction X when connected to the busbar 2C. The voltage detection wire 71 deforms along with the deformation of the branch portion 31, and expands and contracts along the first direction X. The tip of the voltage detection wire 71 is connected to the connection portion 20 of the busbar 2C. The voltage detection wire 71 and the connection portion 20 are connected to each other by, for example, soldering.

[0025] The branch portion 31 is configured to be extendable and contractible along the first direction X when the voltage detection line 71 is connected to the busbar 2C. That is, the branch portion 31 is configured to be extendable and contractible when the busbar 2C is positioned as designed. This allows the branch portion 31 to absorb tolerances in the first direction X and follow any positional deviations of the busbar 2C. Furthermore, the branch portion 31, in which the multiple slits 31a and 31b are formed, can flexibly deform along the second direction Y and the third direction Z. That is, the branch portion 31 has the flexibility to absorb tolerances in the second direction Y and the third direction Z and follow any positional deviations of the busbar 2C. In this way, the busbar module 1 of this embodiment can improve its followability to the busbar 2.

[0026] The branch portion 31 can have any shape that allows it to expand and contract in the first direction X. An example of an expandable branch portion 31 is shown in Figures 4 and 5. As shown in Figure 4, the branch portion 31 has a base portion 32, a tip portion 33, and an expandable portion 34. The shape of the branch portion 31 in a plan view is approximately L-shaped.

[0027] The base portion 32 is a portion connected to the trunk portion 30 and protrudes from the trunk portion 30 in the second direction Y. The shape of the base portion 32 in a plan view is approximately L-shaped. The tip portion 33 is a portion located at the tip of the branch portion 31 and is connected to the busbar 2. The expandable portion 34 is located between the base portion 32 and the tip portion 33 and extends along the first direction X.

[0028] 4, the stretchable portion 34 has a first side 341, a second side 342, a plurality of first slits 34a, a plurality of second slits 34b, and a plurality of notches 34c. The first slits 34a are slits extending from the first side 341 toward one side Y1 in the second direction Y. The second slits 34b are slits extending from the second side 342 toward the other side Y2 in the second direction Y. The first slits 34a and the second slits 34b face each other in the second direction Y.

[0029] The cutout 34c is formed in the region between the first side 341 and the second side 342, and penetrates the covering 8 along the third direction Z. The cutout 34c extends along the second direction Y. The cutout 34c is located between one pair of slits 34a, 34b and another adjacent pair of slits 34a, 34b. The voltage detection wire 71 is routed along the second slit 34b and the cutout 34c. In other words, the voltage detection wire 71 is routed so as to bypass the second slit 34b and the cutout 34c.

[0030] A conductive plate 33a connected to the bus bar 2 is disposed on the tip portion 33. The plate 33a is exposed from the covering portion 8. The voltage detection line 71 is connected to the bus bar 2 via the plate 33a.

[0031] As shown in FIG. 5 , the expandable portion 34 is stretched along the first direction X when the branch portion 31 is connected to the busbar 2. The expandable portion 34 extends along the first direction X by widening the widths of the slits 34a, 34b and the notches 34c. Meanwhile, the expandable portion 34 contracts along the first direction X by narrowing the widths of the slits 34a, 34b and the notches 34c. The voltage detection line 71 deforms together with the deformation of the expandable portion 34, and expands and contracts along the first direction X. The plate 33a of the tip portion 33 is connected to the connection portion 20 of the busbar 2.

[0032] The expandable portion 34 is configured to be expandable and contractible along the first direction X when the tip portion 33 is connected to the bus bar 2. That is, the branch portion 31 is formed so that the expandable portion 34 is connected to the bus bar 2C in an expandable and contractible state when the bus bar 2 is in a designed position. The expandable portion 34 also has flexibility to absorb tolerances in the second direction Y and the third direction Z and follow any positional deviation of the bus bar 2.

[0033] Figure 6 shows another example of an extendable branch portion 31. The branch portion 31 shown in Figure 6 has a base portion 32, a tip portion 33, and an extendable portion 34. The extendable portion 34 has a serpentine shape in a plan view. The extendable portion 34 has a plurality of notches 34d facing one side in the second direction Y and a plurality of notches 34e facing the other side Y2 in the second direction Y.

[0034] Arc portions 34f, 34g are formed by the cutouts 34d, 34e. The shape of the arc portion 34f in plan view is an arc shape that faces the other side Y2 in the second direction Y. The shape of the arc portion 34g in plan view is an arc shape that faces one side Y1 in the second direction Y. In the stretchable portion 34, the portion between the arc portions 34f and 34g extends along the second direction Y. The line width W1 of the stretchable portion 34 is sufficiently smaller than the width W2 of the base portion and the tip portion 33.

[0035] The voltage detection wire 71 is routed along the notches 34d and 34e. That is, the voltage detection wire 71 has a serpentine shape similar to the shape of the expandable portion 34. The expandable portion 34 and the voltage detection wire 71, which have a serpentine shape, are expandable and contractible along the first direction X.

[0036] FIG. 7 shows another example of an extendable branch portion 31. The branch portion 31 shown in FIG. 7 has a base portion 32, a tip portion 33, and an extendable portion 34. The extendable portion 34 has a generally rhombic shape in plan view. The extendable portion 34 has two notches 34h facing one side Y1 in the second direction Y, two notches 34i facing the other side Y2 in the second direction Y, and a cutout 34j. The cutout 34j has a generally rhombic shape in plan view. The cutout 34j penetrates the center of the extendable portion 34 along the third direction Z.

[0037] The two notches 34h and the cutout 34j form a pair of oblique sides 34k, 34k. The pair of oblique sides 34k, 34k are inclined with respect to the first direction X and are connected to each other. One oblique side 34k is connected to the base portion 32, and the other oblique side 34k is connected to the tip portion 33.

[0038] The two notches 34i and the cutouts 34j form a pair of oblique sides 34m, 34m. The pair of oblique sides 34m, 34m are inclined with respect to the first direction X and are connected to each other. One oblique side 34m is connected to the base portion 32, and the other oblique side 34m is connected to the tip portion 33.

[0039] The voltage detection wire 71 is routed inside the pair of oblique side portions 34m, 34m. That is, the voltage detection wire 71 is routed along the notch 34i and the cutout 34j. The diamond-shaped expandable portion 34 is expandable along the first direction X. Furthermore, the voltage detection wire 71 routed in the pair of oblique side portions 34m, 34m is expandable along the first direction X.

[0040] As described above, the busbar module 1 of this embodiment includes a plurality of busbars 2 and a flexible, plate-shaped circuit body 3. The plurality of busbars 2 are aligned along the first direction X and connected to the battery cells 120. The circuit body 3 includes a plurality of detection wires 7 connected to the busbars 2. The circuit body 3 includes a trunk portion 30 in which the plurality of detection wires 7 are arranged, and branch portions 31 branching from the trunk portion 30. The branch portions 31 are arranged with the detection wires 7 connected to the busbars 2.

[0041] The branch portion 31 has an expandable portion 34 that is expandable and contractable along the first direction X. The expandable portion 34 has a slit or notch formed in a direction intersecting the first direction X when the circuit body 3 is viewed in a plan view. The detection wire 7 of the expandable portion 34 is routed along the slit or notch. The busbar module 1 of this embodiment can absorb tolerances in the first direction X by the expandable portion 34. Therefore, the busbar module 1 of this embodiment can improve its followability with respect to the busbar 2.

[0042] The branch portion 31 can absorb tolerances in the second direction Y and the third direction Z due to the flexibility of the circuit body 3. Furthermore, the expandable portion 34 formed to be expandable can appropriately absorb tolerances in the second direction Y and the third direction Z.

[0043] The expandable portion 34 can achieve both a low profile for the busbar module 1 and a tolerance absorbing function. As a comparative example, a busbar module that absorbs tolerances by bending the branch portions 31 in the third direction Z will be considered. The busbar module of the comparative example requires an accommodation space with a height in the third direction Z to accommodate the bending portions of the branch portions 31. In contrast, the busbar module 1 of this embodiment can absorb the intersection in the first direction X without forming bending portions in the branch portions 31, thereby enabling the busbar module 1 to be low profile.

[0044] 4 and 5 of this embodiment has a plurality of slits extending in the second direction Y and a notch 34c extending in the second direction Y. The plurality of slits includes a plurality of first slits 34a facing one side Y1 in the second direction Y and a plurality of second slits 34b facing the other side Y2 in the second direction Y. The first slits 34a and the second slits 34b face each other in the second direction Y. The notch 34c is disposed between a pair of the first slits 34a and the second slits 34b and an adjacent pair of the first slits 34a and the second slits 34b.

[0045] The stretchable portion 34 formed by the plurality of slits 34a, 34b and notches 34c makes it possible to reduce the area used by the flexible printed circuit board. In other words, it is possible to minimize the area of ​​the circuit body 3 when the stretchable portion 34 is in its most contracted state.

[0046] The branch portion 31 of this embodiment is configured to be connected to the busbar 2 while, for example, the extension / contraction portion 34 is stretched. As an example, the branch portion 31 shown in FIG. 4 is configured so that the plate 33a can be opposed to the connection portion 20 of the busbar 2 by stretching the extension / contraction portion 34 in the first direction X. This makes it easy to make the branch portion 31 follow the busbar 2 without bending the branch portion 31.

[0047] The circuit body 3 is not limited to a flexible printed circuit board. The circuit body 3 may be formed of another flexible circuit body. For example, the circuit body 3 may be formed of an FFC (Flexible Flat Cable). In the circuit body 3, the detection line 7 may be an electric wire or may be formed by printing.

[0048] [Modification of the embodiment] The extensible length of the expandable portion 34 may be different between the branch portion 31 located at the end in the first direction X and the other branch portions 31. For example, the expandable portion 34 located at the end may be set to have a larger maximum extension amount than the other expandable portions 34. For example, in the busbar module 1 shown in FIG. 1 , the maximum extension amount of the branch portion 31 corresponding to the busbar 2C may be larger than the maximum extension amount of the branch portions 31 corresponding to the other busbars 2 in the first busbar group 2A. This makes it possible to minimize the area used by the flexible printed circuit board used by the circuit body 3.

[0049] The contents disclosed in the above-described embodiments and modifications can be implemented in appropriate combinations. [Explanation of symbols]

[0050] 1 Busbar module 2: bus bar, 2A: first bus bar group, 2B: second bus bar group, 2C: bus bar 3 circuit body 4 cases 5 Thermistor 6 Connectors 7 Detection Line 8 Covering part 20: Connection part, 21: Terminal part 30: trunk portion, 31: branch portion, 31a, 31b: slits 32: base portion, 33: tip portion, 34: stretchable portion, 34a: first slit 34b: second slit, 34c: notch, 34d, 34e: notch 34f, 34g: Arc section, 34h, 34i: Notch, 34j: Cutout 34k, 34m: hypotenuse part 71: Voltage detection wire, 72: Temperature detection wire 100: Battery pack, 110: Battery module, 120: Battery cell X: first direction, Y: second direction, Z: third direction

Claims

1. a plurality of bus bars arranged along a first direction and connected to the battery cells; a flexible plate-shaped circuit body having a plurality of detection lines connected to the bus bar; Equipped with the circuit body includes a trunk portion in which the plurality of detection lines are arranged, and branch portions branching from the trunk portion and in which the detection lines connected to the bus bar are arranged, The branch portion has an extensible portion that is extensible along the first direction, the stretchable portion has a slit or a notch formed in a direction intersecting with the first direction when the circuit body is viewed in a plan view, the detection line of the stretchable portion is routed along the slit or the notch, the stretchable portion has a plurality of slits extending in a second direction perpendicular to the first direction when the circuit body is seen in a plan view, and a plurality of notches extending in the second direction, the plurality of slits include a plurality of first slits directed toward one side in the second direction and a plurality of second slits directed toward the other side in the second direction, the first slit and the second slit face each other in the second direction, The cuts are arranged between a pair of the first slit and the second slit and another adjacent pair of the first slit and the second slit. A busbar module characterized by:

2. A plurality of bus bars arranged along a first direction and connected to battery cells; a flexible plate-shaped circuit body having a plurality of detection lines connected to the bus bar; Equipped with the circuit body includes a trunk portion in which the plurality of detection lines are arranged, and branch portions branching from the trunk portion and in which the detection lines connected to the bus bar are arranged, The branch portion has an extensible portion that is extensible along the first direction, the stretchable portion has a slit or a notch formed in a direction intersecting with the first direction when the circuit body is viewed in a plan view, the detection line of the stretchable portion is routed along the slit or the notch, The branch portion is configured to be connected to the bus bar while stretching the expandable portion. A busbar module characterized by:

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