Busbar structure

Abstract

The utility model provides a busbar structure which can measure voltage again without replacing or repairing a voltage detection part when the heat of a busbar fades. A busbar structure (10) is provided with: a busbar (12) that connects a plurality of batteries; a voltage detection unit (14) that is provided on the busbar (12) and detects the voltage of the battery; a first member (16), one end of which is fixed to the voltage detection unit (14); a second member (18) disposed outside the first member (16) and having one end fixed to the busbar (12); an elastic member (40) provided between the first member (16) and the second member (18); and a swell / shrink member (42) that is provided between the first member (16) and the bus bar (12) and that swells and shrinks so that the voltage detection unit (14) is in contact with the bus bar (12) when the temperature is lower than a predetermined temperature.

Description

Technical Field

[0001] This utility model relates to a bus structure for connecting multiple batteries. Background Technology

[0002] Patent document 1 discloses a busbar structure. In order to detect abnormal overheating of the busbar as early as possible, the melting point of the fixing claws, which are set on the resin frame and fix the voltage detection line terminals to the busbar, is lower than the melting point of the resin frame. When abnormal overheating occurs, the fixing claws will melt before the resin frame melts, thereby causing the voltage detection line terminals to detach from the busbar.

[0003] Patent document 1: Japanese Patent Application Publication No. 2012-089343.

[0004] In the bus structure described in Patent Document 1, once the retaining claw melts, the bus detaches from the voltage detection line terminal, making voltage detection impossible until a new retaining claw is used to fix the voltage detection line terminal to the bus. Therefore, even if the bus only temporarily heats up to a temperature equal to or higher than the specified temperature, it is necessary to replace or repair the retaining claw. Utility Model Content

[0005] This invention was made in view of the above circumstances, and its purpose is to provide a bus structure that allows voltage to be measured again without replacing or repairing components when the overheating of the bus subsides.

[0006] The first embodiment of the present invention provides a bus structure comprising: a bus that connects multiple batteries; a voltage detection unit disposed on the bus and used for detecting the voltage of the batteries; a first component fixed at one end to the voltage detection unit; a second component disposed on the outside of the first component and fixed at one end to the bus; an elastic component disposed between the first component and the second component; and an expansion and contraction component disposed between the first component and the bus, which expands and contracts in contact with the voltage detection unit and the bus at a temperature below a specified temperature.

[0007] In the bus structure of the first embodiment of this utility model, the expansion and contraction member disposed between the first component and the bus expands and contracts in a manner that brings the voltage detection part into contact with the bus at a temperature below a specified temperature. In other words, the expansion and contraction member expands and contracts in a manner that separates the voltage detection part from the bus at a specified temperature. That is, when the expansion and contraction member expands at a temperature equal to or higher than the specified temperature, the expansion and contraction member overcomes the force of the elastic member and pushes the first component upward, thus pushing the voltage detection part fixed to the first component upward as well, and separating the voltage detection part from the bus.

[0008] Furthermore, when the expansion and contraction component changes from a temperature equal to or higher than the specified temperature to a temperature lower than the specified temperature, the expansion and contraction component contracts, and the first component is pushed downward by the force of the elastic component, thereby pushing the voltage detection part fixed to the first component downward, and the voltage detection part comes into contact with the bus. In this way, the voltage detection part and the bus will only come into contact when the temperature is lower than the specified temperature, so that when the overheating of the bus (equal to or higher than the specified temperature) subsides, the voltage can be measured again without replacing or repairing the component.

[0009] The second embodiment of the busbar structure of this utility model is the same as the busbar structure described in the first embodiment, wherein the expansion and contraction components are formed of shape memory alloy.

[0010] In the bus structure of the second embodiment of this utility model, since the expansion and contraction component is formed of shape memory alloy, the thermal conductivity of the expansion and contraction component is good, and the overheating of the bus can be detected in a short time.

[0011] The third embodiment of the busbar structure of this utility model is the busbar structure described in the first or second embodiment, wherein the expansion and contraction components are fixed to the busbar by an adhesive with thermal conductivity.

[0012] In the third embodiment of the bus structure of this utility model, since the expansion and contraction component is fixed to the busbar by an adhesive with thermal conductivity, the heat generated by the busbar can be quickly transferred through the expansion and contraction component via the adhesive. In addition, when the expansion and contraction component is formed by a spring component, the contact area, i.e., the heat transfer area, between the busbar and the expansion and contraction component, which is prone to shrinkage due to the adhesive, can be increased.

[0013] The fourth aspect of the busbar structure of this utility model is the busbar structure described in the first aspect, wherein the interior of the expansion and contraction component contains a liquid that vaporizes at a temperature equal to or higher than the specified temperature, and at least a portion of the expansion and contraction component is formed of a material that can expand under internal pressure.

[0014] In the fourth embodiment of the manifold structure of this utility model, the expansion member contains a liquid that vaporizes at a temperature equal to or higher than the aforementioned predetermined temperature, and at least a portion of the expansion member is formed of a material that can expand under internal pressure. Therefore, when the temperature reaches equal to or higher than the predetermined temperature, the liquid vaporizes and the internal pressure increases, thereby causing the portion formed of the expandable material to expand and push the first member upward.

[0015] The fifth embodiment of the busbar structure of this utility model is a busbar structure described in any of the first to fourth embodiments, wherein the first component is formed to be able to slide along the inner wall of the second component.

[0016] In the bus structure of the fifth embodiment of this utility model, since the first component is formed to slide along the inner wall of the second component, it can move along the inner wall of the second component when the first component is pushed upward, making it easier to maintain the horizontal state of the first component. Therefore, the voltage detection unit fixed to the first component can also move while maintaining a horizontal state, thereby improving the detection accuracy of the voltage detection unit.

[0017] The bus structure involved in this utility model allows for voltage measurement again without replacing or repairing components once the overheating of the bus subsides. Attached Figure Description

[0018] Figure 1 This is a schematic top view illustrating the configuration of a battery module according to one embodiment of the present invention.

[0019] Figure 2 for Figure 1 The cross-sectional view of the expansion and contraction component of the busbar structure according to the first embodiment of the present invention at line AA in the figure when it is contracted.

[0020] Figure 3 for Figure 1 The first embodiment of the busbar structure according to the present invention, located at line AA, shows a cross-sectional view of the expansion and contraction component during expansion.

[0021] Figure 4A It is a graph showing how temperature changes over time.

[0022] Figure 4B It is a graph showing how the load changes over time.

[0023] Figure 4C It is a graph showing how voltage changes over time.

[0024] Figure 5 This is a flowchart representing a series of control processes for detecting overheating in a bus structure.

[0025] Figure 6 The busbar structure involved in the second embodiment of this utility model is related to... Figure 2 Cross-sectional view of the corresponding expansion and contraction component during contraction.

[0026] Figure 7 The busbar structure involved in the third embodiment of this utility model is related to... Figure 2 Cross-sectional view of the corresponding expansion and contraction component during contraction.

[0027] Figure 8 for Figure 7 Top view of the expansion and contraction components.

[0028] Figure 9 for Figure 8 A cross-sectional view of the DD line.

[0029] Figure 10 The busbar structure involved in the third embodiment of this utility model is related to... Figure 3 Cross-sectional view of the corresponding expansion and contraction component during expansion.

[0030] Figure 11 This is a flowchart representing a series of control processes for overheat detection in an existing busbar structure. Detailed Implementation

[0031] The following is for reference Figures 1-5 The bus structure 10 according to the first embodiment of this utility model will be described. In the description of the drawings, the same or equivalent elements are referred to by the same symbols, and repeated descriptions are omitted.

[0032] Figure 1 This is a schematic top view illustrating the configuration of a battery module 1 according to one embodiment of the present invention. The battery module 1 is used, for example, in various vehicles such as forklifts, hybrid vehicles, and electric vehicles.

[0033] like Figure 1 As shown, the battery module 1 includes multiple battery cells 20 serving as secondary batteries, a bus structure 10 including multiple busbars 12 and multiple voltage detection units 14, and conductive components 30. As an example, the battery module 1 of this embodiment includes four battery cells 20, three busbars 12, and four voltage detection units 14. The four battery cells 20 are arranged in one direction. As an example, the battery cells 20 may be lithium-ion batteries or the like.

[0034] Each battery cell 20 has a frame 22 and a pair of external terminals 24. The frame 22 is formed in a generally flat, generally cuboid shape. For the pair of external terminals 24, one is indicated by a dotted line as the positive terminal, and the other as the negative terminal. In this embodiment, in... Figure 1 The two battery cells 20 shown on the upper side of the paper have a positive terminal on the right and a negative terminal on the left. Conversely, the two battery cells 20 shown on the lower side of the paper have a positive terminal on the left and a negative terminal on the right. A pair of external terminals 24 are disposed on the outer (upper) flat surface of the frame 22, facing outward.

[0035] The busbar 12 is formed in a flat plate shape and electrically connects battery cells 20 that are adjacent to each other in one direction. Specifically, the external terminals 24 of adjacent battery cells 20 are electrically connected. In this embodiment, as... Figure 1As shown, on the left, one bus 12 electrically connects the two negative terminals and two positive terminals of the four battery cells 20, which serve as external terminals 24. On the other hand, on the right, one of the two bus 12s (the upper one) electrically connects the two positive terminals of the adjacent two battery cells 20, which serve as external terminals 24, while the other (the lower one) bus 12 electrically connects the two negative terminals of the remaining two adjacent battery cells 20, which serve as external terminals 24. Here, in... Figure 1 A hollow arrow indicates the flow of electric current.

[0036] Voltage detection unit 14 measures the voltage of each battery cell 20. Voltage detection unit 14 can use a known voltmeter. Each voltage detection unit 14 is connected to the Electronic Control Unit (ECU) 32 via wire 14A. Furthermore, in Figure 1 Only the voltage detection unit 14 is shown in the figure, but in practice, the components included in the bus structure 10, which will be described in detail later, also exist.

[0037] The conductive component 30 is disposed in connection with each battery cell 20. In this embodiment, the conductive component 30 is disposed in contact with the lower surface of each battery cell 20. The conductive component 30 has a cooling function for cooling the battery cell 20. In this embodiment, as an example, the conductive component 30 is constituted by a cooler, but the present invention is not limited thereto, and the conductive component 30 may also be constituted by a component different from a cooler.

[0038] In addition, although the illustration is omitted, a separator made of an insulator such as resin can also be arranged between adjacent battery cells 20.

[0039] Next, the bus structure 10 will be described. For example... Figure 2 As shown, the bus structure 10 includes a bus 12, a voltage detection unit 14, a first component 16, a second component 18, an elastic component 40, and an expansion / contraction component 42. The voltage detection unit 14 is disposed on the bus 12.

[0040] The first component 16 is a resin structure, and as an example, it has a cylindrical main body 16A and a generally circular edge 16B that protrudes outward from the outer peripheral surface of the main body 16A in a roughly vertical direction. The lower end of the main body 16A is fixed to the upper surface of the voltage detection unit 14.

[0041] The second component 18 is disposed outside the first component 16, and for example has a cylindrical portion 18A formed in a cylindrical shape and a circular plate portion 18B that protrudes substantially horizontally inward from the upper end of the cylindrical portion 18A and has a central opening. The wire 14A is led out from this opening and connected to the ECU 32. In addition, the lower end of the cylindrical portion 18A is fixed to the upper surface of the busbar 12.

[0042] In this embodiment, the first component 16 is configured to slide along the inner wall of the second component 18. Specifically, the side end face of the edge portion 16B of the first component 16 can slide vertically along the inner wall of the cylindrical portion 18A of the second component 18. Furthermore, in Figure 2 and Figure 3 In the middle, the side end face of the edge portion 16B is separated from the inner wall of the cylindrical portion 18A, but in reality, it abuts against the edge to a degree that allows it to slide.

[0043] As an example, the elastic member 40 is composed of a spring member and is disposed between the first member 16 and the second member 18. Specifically, the elastic member 40 is composed of a generally cylindrical spring member, disposed inside the second member 18, and configured to surround the upper end of the edge 16B of the first member 16. In addition, the lower end of the elastic member 40 abuts against the upper surface of the edge 16B of the first member 16, and the upper end abuts against the lower surface of the circular plate portion 18B of the second member 18. The elastic member 40 applies force to the first member 16 on the downward side, i.e., the busbar 12 side.

[0044] The expansion member 42 is formed of shape memory alloy, and for example, is formed of a generally cylindrical spring member. The expansion member 42 is disposed between the first member 16 and the busbar 12. Specifically, the expansion member 42 is disposed on the lower side of the edge 16B of the first member 16, and its lower end is fixed to the busbar 12. In this embodiment, for example, the expansion member 42 is fixed to the upper surface of the busbar 12 by an adhesive 44 with thermal conductivity.

[0045] When the expansion / contraction component 42 is below a predetermined temperature, its elasticity is weak, so it is pressed down by the force of the elastic component 40, causing its length to shrink in the vertical direction (axial direction). Here, in this embodiment, the predetermined temperature is the deformation temperature of the shape memory alloy.

[0046] On the other hand, when the temperature is equal to or higher than the specified temperature, the elasticity of the expansion member 42 becomes stronger compared to the case where the temperature is lower than the specified temperature. Therefore, through the reaction force opposite to the force exerted by the expansion member 42 on the elastic member 40, the expansion member 42 returns to its original shape. That is, the expansion member 42 elongates (expands) in the vertical direction (axial direction). In addition, when the temperature drops to the specified temperature, the elasticity of the expansion member 42 weakens, and under the pressing force of the elastic member 40, its vertical direction (axial direction) shrinks.

[0047] like Figure 4A As shown, for example, if the temperature of the expansion / contraction component 42 rises over time, such as... Figure 4B As shown, the load representing the reaction force of the expansion and contraction component 42 begins to increase from time C when the specified temperature B is reached. Furthermore, when the load representing the reaction force of the expansion and contraction component 42 is greater than the load representing the force acting on the manifold 12 side of the elastic component 40, i.e., load D (ratio...),... Figure 4B (The load indicated by arrow E is on the right side). During the time F when the load D < the reaction force, the expansion and contraction component 42, as shown... Figure 3 As shown, the length in the vertical direction (axial direction) begins to elongate (expand), and the edge 16B of the first component 16 begins to be pushed upward.

[0048] When the upward movement of the flange 16B begins, the first component 16 is also pushed upward, and therefore the voltage detection unit 14 fixed to the first component 16 also begins to move upward and begin to separate from the busbar 12. When the voltage detection unit 14 is completely separated from the busbar 12, then... Figure 4C As shown, the voltage detected by the voltage detection unit 14 is 0V, as indicated by arrow G.

[0049] On the other hand, from Figure 3 When the expansion member 42 shown is in an expanded state, and the temperature of the expansion member 42 drops below a specified temperature, the load D representing the force acting on the manifold 12 side of the elastic member 40 is greater than the load representing the reaction force of the expansion member 42 (ratio). Figure 4B (The load indicated by arrow E is on the left). Therefore, the expansion member 42 is pressed down by the force of the elastic member 40, and its length in the vertical direction (axial direction) begins to contract, pushing the first member 16 downwards as well. Consequently, the voltage detection unit 14 fixed to the first member 16 also begins to move downwards, as... Figure 2 As shown, the expansion / contraction member 42 moves away from the edge 16B of the first member 16, and the voltage detection unit 14 contacts the busbar 12. When the voltage detection unit 14 contacts the busbar 12, the voltage detected by the voltage detection unit 14 becomes a value greater than 0V.

[0050] Next, a series of control methods for overheating detection in the busbar structure 10 will be explained. For example... Figure 5 As shown, firstly, in step S11, the ECU 32 acquires the voltage value between the battery cells 20 output from the voltage detection unit 14 via the wire 14A. In step S12, the ECU 32 determines whether the acquired voltage value is greater than a preset threshold. In this embodiment, as an example, the threshold is set to "0".

[0051] If the voltage value obtained in step S12 is greater than the threshold (step S12; Yes), ECU32 returns to step S11 and performs processing after step S11. On the other hand, if the voltage value obtained in step S12 is less than or equal to the threshold (step S12; No), ECU32 determines in step S13 that an abnormality has occurred between battery cells 20.

[0052] Typically, in the event of an anomaly within a parallel-configured battery cell 20, the resistance of the busbar 12 connected to the malfunctioning battery cell 20 increases compared to when no anomaly occurs. Therefore, due to the resistance difference, a larger current flows from the side with higher resistance to the side with lower resistance, causing the temperature of the busbar 12 to exceed expectations. If the temperature of the busbar 12 becomes high, heat is transferred through the thermally conductive adhesive 44 to the expansion / contraction member 42 fixed to the upper surface of the busbar 12, causing the temperature of the expansion / contraction member 42 to also rise.

[0053] Once the temperature of the expansion / contraction component 42 rises above or equal to a predetermined temperature, it overcomes the force of the elastic component 40 and returns to its original shape, expanding in the vertical direction and pushing the edge 16B of the first component 16 upwards. As a result, the first component 16 floats up, and the voltage detection unit 14 fixed to it also floats up, causing the voltage output by the voltage detection unit 14 to become 0V. Therefore, according to the above structure, the high-temperature state caused by an abnormality within the battery cell 20 can be captured as a voltage change.

[0054] Then, the voltage value obtained by ECU32 has become 0V (threshold). In step S13, ECU32 determines that an anomaly has occurred between bus 12, i.e., battery cells 20. Therefore, in step S14, ECU32 intervenes in the protection control of battery module 1, causing it to execute a reverse driving mode. The reverse driving mode includes limiting the output of power from the battery module. Then, ECU32 returns to step S11 to perform the processing after step S11.

[0055] The function and effect of the bus structure 10 in the first embodiment will be explained next.

[0056] In the bus structure 10 according to the first embodiment, the expansion member 42 disposed between the first component 16 and the bus 12 expands and contracts in a manner that brings the voltage detection unit 14 into contact with the bus 12 when the temperature is below a predetermined temperature. In other words, the expansion member 42 expands and contracts in a manner that separates the voltage detection unit 14 from the bus 12 when the temperature is above or equal to a predetermined temperature (i.e., above the predetermined temperature). That is, when the expansion member 42 expands at a temperature above the predetermined temperature, the expansion member 42 overcomes the force of the elastic member 40 and pushes the first component 16 upward. Therefore, the voltage detection unit 14 fixed to the first component 16 is also pushed upward, and the voltage detection unit 14 separates from the bus 12.

[0057] Then, when the expansion / contraction component 42 changes from above to below the specified temperature, it contracts. Because the first component 16 is pushed downwards by the force of the elastic component 40, the voltage detection unit 14, fixed to the first component 16, is also pushed downwards, and the voltage detection unit 14 comes into contact with the busbar 12. In this way, the voltage detection unit 14 only contacts the busbar 12 when the temperature is below the specified temperature. Therefore, when the overheating of the busbar 12 at or above the specified temperature subsides, the voltage can be measured again without replacing or repairing the component.

[0058] Furthermore, in the bus structure 10 according to the first embodiment, since the expansion member 42 is formed of shape memory alloy, the thermal conductivity of the expansion member 42 becomes good, and the overheating of the bus can be detected in a short time.

[0059] Furthermore, in the busbar structure 10 according to the first embodiment, since the expansion member 42 is fixed to the busbar 12 by an adhesive 44 having thermal conductivity, the heat generated by the busbar 12 can be quickly transferred through the expansion member 42 via the adhesive 44. Additionally, since the expansion member 42 is formed of a spring member, the contact area, i.e., the heat transfer area, between the busbar 12 and the expansion member 42, which is prone to shrinkage due to the adhesive 44, can be increased.

[0060] Furthermore, in the bus structure 10 according to the first embodiment, the first component 16 is configured to slide along the inner wall of the second component 18. Therefore, when the first component 16 is pushed upward, it can move along the inner wall of the second component 18, making it easier to maintain the horizontal state of the first component 16. As a result, the voltage detection unit 14 fixed to the first component 16 can also move while maintaining a horizontal state, thus improving the detection accuracy of the voltage detection unit 14.

[0061] Furthermore, in the bus structure 10 according to the first embodiment, when overheating is detected, the high temperature state caused by an abnormality within the battery cell 20 can be captured as a voltage change. Here, a conventional bus structure will be described. A flowchart illustrating a series of control processes for overheating detection in a conventional bus structure is provided. In a conventional bus structure, such as... Figure 11 As shown, firstly, in step S21, the ECU obtains the battery cell voltage value output by the voltage detection unit, and in step S22, it also obtains the current value. Then, in step S23, the ECU obtains the IV characteristic by plotting the obtained voltage and current values, and calculates the resistance value. In step S24, the ECU determines whether the calculated resistance value is below a preset threshold (i.e., less than or equal to the threshold). If it is below the threshold (step S24; Yes), the ECU returns to step S21 and performs the processing after step S21.

[0062] On the other hand, if the resistance value obtained in step S24 is greater than the threshold (step S24; no), in step S25, the number of times the resistance value is greater than the threshold, i.e., the number of times the resistance is abnormal, is counted. In step S26, the ECU determines whether the count is above a preset threshold. If the count is below the threshold (step S26; no), the ECU returns to step S21 and performs the processing after step S21.

[0063] On the other hand, if the count exceeds the threshold in step S26 (step S26; Yes), the ECU intervenes in the protection control of the battery module, causing it to execute a reverse driving mode. Then, the ECU returns to step S21 to perform the processing after step S21.

[0064] Therefore, when calculating the resistance in the existing bus structure, it takes about 30 seconds to calculate the resistance value once, so there is a time requirement for calculating the resistance value once. In addition, in order to avoid false positives, when the resistance value exceeds the threshold multiple times (e.g., 3 times), it is determined that an abnormality has occurred between battery cells, and it takes about 60 to 90 seconds for the abnormality to be determined.

[0065] Compared to existing bus structures, in the bus structure 10 of the first embodiment, the abnormality between battery cells 20 is determined only by judging the value of the voltage output from the voltage detection unit 14, so the time required for abnormality determination can be shortened compared to the existing ones.

[0066] Furthermore, the bus structure in this embodiment does not require additional sensors, such as devices for detecting current values, thus reducing costs. For example, by additionally providing a temperature sensor to detect the temperature of the bus 12, the bus 12 could be brought into contact with or separated from the voltage detection unit 14 based on the output from the temperature sensor. However, in this case, the cost of mounting the temperature sensor and the mounting means would increase the overall cost. In this embodiment, the already mounted voltage detection unit 14 can be utilized, thus reducing costs.

[0067] Furthermore, in the above embodiment, the expansion member 42 is set as a spring member formed of shape memory alloy, but the present invention is not limited thereto. Other embodiments of the expansion member will be described below. In addition, regarding the bus structure on which the expansion member is mounted, the same configuration as in the first embodiment is indicated by the same reference numerals and the description is omitted; only the different parts will be described in detail.

[0068] The following is for reference Figure 6 The expansion and contraction member 46 mounted on the bus structure 10A according to the second embodiment of this utility model will be described. For example... Figure 6 As shown, the expansion / contraction member 46 of the second embodiment includes a spring 46A formed of shape memory alloy and a generally disk-shaped flat plate member 46B formed of shape memory alloy. The spring 46A has the same configuration as the expansion / contraction member 42 of the first embodiment described above. The flat plate member 46B is fixed to the upper surface of the busbar 12 by a thermally conductive adhesive 44. Similarly, the spring 46A is fixed to the upper surface of the flat plate member 46B by a thermally conductive adhesive 44.

[0069] Even if the expansion and contraction member 46 of the second embodiment is composed of two parts, the same effect as when using the expansion and contraction member 42 of the first embodiment can be obtained.

[0070] The following is for reference Figures 7-10 The expansion and contraction component 50 mounted in the bus structure 10B according to the third embodiment of this utility model will be described. For example... Figures 7-9 As shown, the expansion and contraction member 50 of the third embodiment has a housing portion 52 and a cover portion 54. The housing portion 52 is formed of a cylindrical box that is open at the top, and is made of a rigid material that is not deformed by internal pressure as described later.

[0071] The cover 54 covers the upper part of the housing portion 52, such as Figure 8 The disc shown is formed as a circular plate with an opening at the center, and is made of a material that can deform (expand) in the vertical (axial) direction using the internal pressure described later.

[0072] The housing 52 contains a liquid 60 that vaporizes at a temperature above a specified temperature. Here, the specified temperature is set to the boiling point of the liquid 60. The liquid 60 is defined as a liquid whose boiling point corresponds to the temperature of the busbar 12 when an abnormality is detected in the battery cell 20.

[0073] When the cover 54 is installed on the upper part of the housing 52, the internal pressure of the expansion and contraction member 50 increases due to the vaporization of the liquid 60, such as... Figure 10 As shown, the cover 54 expands in the vertical direction.

[0074] That is, when the expansion and contraction component 50 is below the preset temperature, the internal pressure does not rise, so the first component 16 is pressed by the force of the elastic component 40, and the voltage detection part 14 fixed to the first component 16 contacts the busbar 12.

[0075] On the other hand, if the temperature of the manifold 12 rises and the temperature of the liquid 60 reaches or exceeds a specified temperature, the internal pressure increases compared to the case where the temperature is below the specified temperature. Therefore, the cover 54 deforms (expands) in the vertical (axial) direction. Figure 10 As shown, the expansion of the cover 54 overcomes the force of the elastic member 40 and pushes the first member 16 upward. Therefore, the voltage detection unit 14 fixed to the first member 16 is also pushed upward, and the voltage detection unit 14 is separated from the busbar 12.

[0076] On the other hand, from Figure 10 When the expansion member 50 is in an expanded state, and the temperature of the liquid 60 inside the expansion member 50 drops below a specified temperature, the internal pressure decreases compared to the situation above the specified temperature. Therefore, the deformation (expansion) of the cover 54 will contract and return to its original shape. That is, as shown... Figure 7 As shown, by retracting the cover 54, the first component 16 is pressed down by the force of the elastic member 40, and the voltage detection unit 14 fixed to the first component 16 is also pressed down, and the voltage detection unit 14 comes into contact with the bus 12.

[0077] The expansion member 50 of the third embodiment can achieve the same effect as the expansion member 42 of the first embodiment, even when the internal pressure rises and falls due to the vaporization of the liquid 60 contained inside.

[0078] In addition, in the above embodiment, the main body 16A of the first component 16 and the cylindrical part 18A of the second component 18 are cylindrical, but the present invention is not limited to this, and can also be polygonal cylindrical, and can be appropriately modified.

[0079] Furthermore, in the above embodiment, the edge 16B of the first component 16 is set as a circular plate, but the present invention is not limited to this. As long as the expansion and contraction components can abut, for example, it can also be a structure with multiple outwardly protruding protrusions, and the shape is not particularly limited.

[0080] Furthermore, in the above embodiment, the battery module 1 is configured with battery cells 20 connected in parallel, but the present invention is not limited to this. For example, it can also be configured with battery cells 20 connected in series.

[0081] Furthermore, in the first and second embodiments described above, the expansion and contraction components 42 and 46 are fixed to the busbar 12 using a thermally conductive adhesive, but the present invention is not limited to this. Known techniques other than adhesives can also be used for fixing.

[0082] Furthermore, the configuration of this utility model is not limited to the above embodiments. As long as the problem can be solved, the configuration can be appropriately changed.

Claims

1. A busbar structure, characterized in that, have: Busbars are used to connect multiple batteries; A voltage detection unit is disposed on the busbar for detecting the voltage of the battery; The first component has one end fixed to the voltage detection unit; The second component is disposed on the outside of the first component, and one end of the second component is fixed to the busbar; An elastic member is disposed between the first member and the second member; and An expansion and contraction component is disposed between the first component and the busbar, and the expansion and contraction component expands and contracts in a manner that the voltage detection part contacts the busbar when the temperature is below a specified temperature.

2. The busbar structure according to claim 1, characterized in that, The expansion and contraction component is formed of shape memory alloy.

3. The busbar structure according to claim 1, characterized in that, The expansion and contraction components are fixed to the manifold by an adhesive with thermal conductivity.

4. The busbar structure according to claim 1, characterized in that, The expansion member contains a liquid that vaporizes at a temperature equal to or above the specified temperature, and at least a portion of the expansion member is formed of a material that can expand under internal pressure.

5. The busbar structure according to claim 1, characterized in that, The first component is configured to slide along the inner wall of the second component.

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