Fuse device and battery module

Abstract

A first fuse device (40A) is provided with: a narrow section (414A) that functions as a fuse; and a first wide section (412A) electrically connected to the narrow section (414A) and having a larger cross-sectional area than the narrow section (414A). A first bend (404A) is provided from the outer edge of the narrow section (414A) to the outer edge of the first wide section (412A).

Description

Technical Field

[0001] The present invention relates to a fuse device and a battery module. Background Art

[0002] Battery modules, such as lithium-ion secondary batteries, sometimes include multiple stacked battery cells. In such battery modules, the multiple battery cells are electrically connected to each other via positive and negative leads extending from the battery cell exteriors. Furthermore, battery modules sometimes include fuses to prevent overcurrent.

[0003] Patent Document 1 describes an example of a fuse for a battery module. In this example, a portion of a conductive plate housed in a bracket is narrower than the rest of the plate. This portion of the conductive plate thus functions as a fuse.

[0004] Patent Document 2 describes an example of a fuse for a battery module. In this example, a portion of a busbar attached to a busbar frame is thinner than the rest of the busbar. This portion of the busbar thus functions as a fuse.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2000-182506

[0008] Patent Document 2: Japanese Patent Application No. 2020-528650 Summary of the Invention

[0009] Problems to be solved by the invention

[0010] For example, as described in Patent Documents 1 and 2, a portion of a conductor with a small cross-sectional area sometimes functions as a fuse. However, depending on the shape of the conductor from the small cross-sectional area portion to the large cross-sectional area portion, it may be difficult to stabilize the melting of the fuse or to increase the mechanical strength of the conductor, making it difficult to achieve the desired fuse characteristics.

[0011] One example of the purpose of the present invention is to achieve desired characteristics of a fuse. Other purposes of the present invention will become clear from the description of this specification.

[0012] Means for solving problems

[0013] One embodiment of the present invention is as follows. [1]

[0015] A fuse device comprises: a first conductor portion functioning as a fuse; and a second conductor portion electrically connected to the first conductor portion and having a larger cross-sectional area than the first conductor portion, the second conductor portion being bent from an outer edge of the first conductor portion to an outer edge of the second conductor portion. [2]

[0017] In the fuse device described in [1], the bend is provided at an inner corner extending from the outer edge of the first conductor portion to the outer edge of the second conductor portion, and the bend at the inner corner is an arc shape having a curvature radius of not less than 1.0 mm and not more than 3.0 mm. [3]

[0019] In the fuse device described in [1], the bend is provided at an inner corner extending from the outer edge of the first conductor portion to the outer edge of the second conductor portion, and the bend at the inner corner is at least partially included in a curved shape passing through an area surrounded by the following contours: the contour of the bend when the bend is in an arc shape with a curvature radius of 1.0 mm; and the contour of the bend when the bend is in an arc shape with a curvature radius of 3.0 mm. [4]

[0021] In the fuse device described in any one of [1] to [3], the cross-sectional area of ​​the first conductor portion is 40 mm 2 Above and 100mm 2 the following. [5]

[0023] A battery module comprising: the fuse device according to any one of [1] to [4]; and at least one battery cell electrically connected to the fuse device.

[0024] Effects of the Invention

[0025] According to the above aspects of the present invention, desired characteristics of the fuse can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a perspective view of the battery module according to the embodiment as viewed from the front.

[0027] Figure 2 This is a perspective view of the battery module according to the embodiment as viewed from the rear.

[0028] Figure 3 It is from Figure 1 Image of the container being removed.

[0029] Figure 4 It is from Figure 2 Image of the container being removed.

[0030] Figure 5 This is a perspective view of a single-unit laminate according to the embodiment as viewed from the front.

[0031] Figure 6 This is an enlarged view of a position where a first fuse device is provided in the first voltage detection device according to the embodiment.

[0032] Figure 7 This is a top view of the first conductor according to the embodiment.

[0033] Figure 8 This is a top view of a first conductor according to a modification. DETAILED DESCRIPTION

[0034] Hereinafter, the embodiment and modification of the present invention will be described using the drawings. In all the drawings, the same components are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

[0035] In this specification, unless otherwise specified, ordinal numbers such as "1st", "2nd", and "3rd" are simply added to distinguish structures with the same name, and do not refer to specific characteristics of the structure (such as order or importance).

[0036] Figure 1 This is a perspective view of the battery module 50 according to the embodiment as viewed from the front. Figure 2 This is a perspective view of the battery module 50 according to the embodiment as viewed from the rear. Figure 3 It is from Figure 1 FIG. 20 is a diagram with the container 20 removed. Figure 4 It is from Figure 2 FIG. 20 is a diagram with the container 20 removed. Figure 5 This is a perspective view of the single-unit laminate 10 according to the embodiment as viewed from the front.

[0037] exist Figures 1 to 5In the diagram, the arrows representing the first direction X, the second direction Y, and the third direction Z indicate the direction from the base end to the front end of the arrow, which is the positive direction, and the direction from the front end to the base end of the arrow is the negative direction. The first direction X represents a direction parallel to the horizontal direction perpendicular to the vertical direction. Specifically, the first direction X represents the front-to-back direction of the battery module 50. The positive direction of the first direction X is from the front to the rear of the battery module 50. The negative direction of the first direction X is from the rear to the front of the battery module 50. The second direction Y represents a direction perpendicular to both the vertical direction and the first direction X. The second direction Y represents the left-to-right direction of the battery module 50. The positive direction of the second direction Y is from the right to the left of the battery module 50, as viewed from the front of the battery module 50. The negative direction of the second direction Y is from the left to the right of the battery module 50, as viewed from the front of the battery module 50. The third direction Z represents a direction parallel to the vertical direction. The positive direction of the third direction Z is a direction from the bottom to the top of the battery module 50 . The negative direction of the third direction Z is a direction from the top to the bottom of the battery module 50 .

[0038] The relationship between the first direction X, the second direction Y, the third direction Z, the vertical direction, and the horizontal direction is not limited to the above example. For example, the battery module 50 may be arranged so that the first direction X or the second direction Y is parallel to the vertical direction.

[0039] Hereinafter, unless otherwise specified, “right” and “left” refer to the right and left, respectively, when viewed from the front of the battery module 50 .

[0040] In this embodiment, the battery module 50 is mounted on a mobile vehicle such as an EV (electric vehicle) or an HEV (hybrid electric vehicle). The capacity of the battery module 50 is, for example, 50 kWh or more and 100 kWh or less. However, the application of the battery module 50 is not limited to this example.

[0041] The battery module 50 includes a cell stack 10, a housing 20, a first voltage detection device 30A, and a second voltage detection device 30B. The first voltage detection device 30A includes a first fuse device 40A. The second voltage detection device 30B includes a second fuse device 40B. Figure 6 As will be described later, the first fuse device 40A includes a fuse electrically connected to the terminal positive lead 112T, and the second fuse device 40B includes a fuse electrically connected to the terminal negative lead 114T.

[0042] like Figure 5As shown, the cell stack 10 includes a plurality of cell groups 100G stacked in the second direction Y. Each cell group 100G includes a plurality of battery cells 100 stacked in the second direction Y. Each battery cell 100 includes an exterior member 102 , a positive electrode lead 112 , and a negative electrode lead 114 .

[0043] In this embodiment, each cell group 100G includes two battery cells 100. However, each cell group 100G may include three or more battery cells 100. Furthermore, in the cell stack 10, rather than connecting multiple cell groups 100G in series, multiple battery cells 100 may be connected in series. In other words, the number of battery cells 100 included in a cell group 100G may be only one.

[0044] Each battery cell 100 is substantially arranged in the longitudinal direction. This does not necessarily mean that the battery cells 100 are strictly arranged in the longitudinal direction. It also means that the battery cells 100 can be tilted obliquely from the third direction Z within a range that does not affect the operation of the battery module 50.

[0045] like Figure 3 as well as Figure 4 As shown, a plurality of adhesive members 104 are arranged on the upper surface of the monomer stack 10. Each adhesive member 104 is, for example, a solidified body of a liquid resin. In the present embodiment, the plurality of adhesive members 104 are regularly arranged. Specifically, the plurality of adhesive members 104 extend parallel to the second direction Y and are arranged parallel to the first direction X. An insulating sheet not shown is arranged above the plurality of adhesive members 104. A sixth cover member 260 described later is arranged above the insulating sheet not shown. In addition, the layout of the adhesive members 104 is not limited to the layout involved in the present embodiment. For example, the adhesive members 104 may also be provided over the entire upper surface of the monomer stack 10. Alternatively, the plurality of adhesive members 104 may also be arranged irregularly, or may also be arranged in a manner consistent with the arrangement of the monomer stack. Figure 3 as well as Figure 4 The adhesive member is also arranged on the lower surface of the single-unit laminate 10 in the same manner as on the upper surface of the single-unit laminate 10 .

[0046] The exterior member 102 houses the positive electrode, negative electrode, and separator (not shown) along with the electrolyte (not shown). In one example, the positive electrode, negative electrode, and separator are stacked in the second direction Y within the exterior member 102. Alternatively, the positive electrode, negative electrode, and separator may be wound within the exterior member 102.

[0047] The positive lead 112 extends substantially horizontally from one of the front end and the rear end of the exterior member 102. The positive lead 112 is electrically connected to the positive electrode in the exterior member 102. In one example, the positive lead 112 contains a metal such as aluminum. The fact that the positive lead 112 extends substantially horizontally does not mean that the positive lead 112 is strictly extended in the horizontal direction. The fact that the positive lead 112 extends substantially horizontally means that the positive lead 112 may be extended in a direction deviating from the horizontal direction within a range that does not affect the operation of the battery module 50.

[0048] The negative lead 114 is extended substantially horizontally from the other of the front end and the rear end of the exterior member 102. The negative lead 114 is electrically connected to the negative electrode in the exterior member 102. In one example, the negative lead 114 contains a metal different from the metal constituting the positive lead 112, such as copper. The fact that the negative lead 114 is extended substantially horizontally does not necessarily mean that the negative lead 114 is strictly extended horizontally. The fact that the negative lead 114 is extended substantially horizontally means that the negative lead 114 may be extended in a direction deviating from the horizontal direction within a range that does not affect the operation of the battery module 50.

[0049] When each cell group 100G includes multiple battery cells 100, these multiple battery cells 100 are connected in parallel. Specifically, the multiple battery cells 100 contained in each cell group 100G are stacked in the second direction Y. In addition, the positive leads 112 of the multiple battery cells 100 contained in each cell group 100G are bundled and connected to each other in the second direction Y. In addition, the negative leads 114 of the multiple battery cells 100 contained in each cell group 100G are bundled and connected to each other in the second direction Y. Adjacent battery cells 100 can be stacked with an adhesive member interposed therebetween. Examples of the adhesive member include double-sided tape and a member obtained by curing a liquid resin.

[0050] Multiple cell groups 100G are connected in series via a lead portion 110. The lead portion 110 includes: multiple positive leads 112 of one cell group 100G among the cell groups 100G adjacent in the second direction Y; and multiple negative leads 114 of the other cell group 100G among the cell groups 100G adjacent in the second direction Y. The multiple positive leads 112 and negative leads 114 contained in the lead portion 110 are joined to each other by joining methods such as laser welding, ultrasonic joining, resistance welding, and bonding. When the material of the positive lead 112 and the material of the negative lead 114 are different, laser welding is also preferred among these joining methods from the perspectives of high or low joining reliability and reduction in the number of components. The lead portion 110 is folded back between the cell groups 100G adjacent in the second direction Y. As a result, the multiple lead portions 110 are arranged in the second direction Y in front of the cell stack 10. Furthermore, a plurality of lead portions 110 are arranged in the second direction Y at the rear of the single laminated body 10 .

[0051] In this embodiment, if Figure 3 As shown, at the junction of the plurality of positive leads 112 and the plurality of negative leads 114 of each lead portion 110 located at the front of the single laminate 10, the plurality of negative leads 114 are located further forward than the plurality of positive leads 112. Figure 4 As shown, at the junction of the plurality of positive leads 112 and the plurality of negative leads 114 in each lead portion 110 located at the rear of the unit laminate 10, the plurality of positive leads 112 are located further rearward than the plurality of negative leads 114. Furthermore, when the plurality of positive leads 112 are located further forward than the plurality of negative leads 114 at the front of the unit laminate 10, the material of the first front end portion 314A, described later, is preferably the same as that of the positive leads 112.

[0052] In this embodiment, if Figure 3 As shown, the plurality of positive electrode leads 112 included in the cell group 100G at one end of the plurality of cell groups 100G connected in series are located on the right front side of the cell stack 10. Hereinafter, the plurality of positive electrode leads 112 included in the cell group 100G at one end of the plurality of cell groups 100G connected in series will be referred to as terminal positive electrode leads 112T as needed. Figure 4 As shown, the plurality of negative electrode leads 114 included in the cell group 100G at the other end of the plurality of cell groups 100G connected in series are located on the left rear side of the cell stack 10. Hereinafter, the plurality of negative electrode leads 114 included in the cell group 100G at the other end of the plurality of cell groups 100G connected in series will be referred to as a terminal negative electrode lead 114T as needed.

[0053] The structure of the cell stack 10 is not limited to that described in this embodiment. For example, the terminal negative electrode lead 114T may be located on the left front side rather than the left rear side of the cell stack 10. In this example, both the terminal positive electrode lead 112T and the terminal negative electrode lead 114T are located on the front side. Whether the terminal negative electrode lead 114T is located on the left front side or the left rear side of the cell stack 10 can be adjusted based on the number of cell groups 100G stacked in the second direction Y.

[0054] In this embodiment, if Figure 3 As shown, the front surface of the joint between the positive lead 112 and the negative lead 114 of each lead portion 110 located in front of the single laminate 10 is substantially parallel to the direction perpendicular to the first direction X. The so-called front surface of the joint is substantially parallel to the direction perpendicular to the first direction X, not only means that the front surface of the joint is strictly parallel to the direction perpendicular to the first direction X. The so-called front surface of the joint is substantially parallel to the direction perpendicular to the first direction X, but also means that the front surface of the joint is slightly deformed from the state where the front surface of the joint is parallel to the direction perpendicular to the first direction X within a range that does not affect the function of the lead portion 110. In this embodiment, compared with the case where the front surface of the joint is bent, the first voltage detection portion 310A described later can be easily joined to the front surface of the lead portion 110. In other examples different from this embodiment, the front surface of the above-mentioned joint may also be bent.

[0055] In this embodiment, if Figure 4 As shown, the rear surface of the joint between the positive lead 112 and the negative lead 114 of each lead portion 110 located at the rear of the single laminate 10 is substantially parallel to the direction perpendicular to the first direction X, just like the front surface of the joint between the positive lead 112 and the negative lead 114 of each lead portion 110 located at the front of the single laminate 10.

[0056] The housing 20 houses the cell stack 10, the first voltage detection device 30A, and the second voltage detection device 30B. The housing 20 includes a first cover member 210, a second cover member 220, a third cover member 230, a fourth cover member 240, a fifth cover member 250, and a sixth cover member 260. In this embodiment, the first cover member 210, the second cover member 220, the third cover member 230, the fourth cover member 240, the fifth cover member 250, and the sixth cover member 260 are made of, for example, a metal primarily composed of aluminum. However, the materials constituting the first cover member 210, the second cover member 220, the third cover member 230, the fourth cover member 240, the fifth cover member 250, and the sixth cover member 260 are not limited to this example.

[0057] The first cover member 210 covers the front side of the cell stack 10 and the first voltage detection device 30A. The second cover member 220 covers the rear side of the cell stack 10 and the second voltage detection device 30B. The third cover member 230 covers the right side of the cell stack 10. The fourth cover member 240 covers the left side of the cell stack 10. The fifth cover member 250 covers the bottom side of the cell stack 10. The sixth cover member 260 covers the top side of the cell stack 10.

[0058] like Figure 1 as well as Figure 2 As shown, a "+" sign is marked on the right front side of the upper surface of the sixth cover member 260. In addition, a "-" sign is marked on the left rear side of the upper surface of the sixth cover member 260. The "+" sign indicates Figure 3 The positive lead 112T is located at the position marked with a "+" sign. The "-" sign indicates Figure 4 The illustrated negative terminal lead 114T is located at the position indicated by the "-" sign. Therefore, even when the user of the battery module 50 is unable to see the cell stack 10 from outside the housing 20, they can still identify the positions of the positive terminal lead 112T and the negative terminal lead 114T based on the "+" and "-" signs.

[0059] The first voltage detection device 30A includes a first holding body 300A, a plurality of first voltage detection units 310A, a plurality of first voltage detection lines 320A, and a first connector 330A.

[0060] The first retaining member 300A is located in front of the cell stack 10. The first retaining member 300A is an insulator. Resins such as polypropylene, polybutylene terephthalate, and modified polyphenylene ether, or resins with comparable or higher hardness, heat resistance, and insulating properties, are used as insulators. The first retaining member 300A is attached to the housing 20 using mechanical fastening methods such as snaps and screws.

[0061] Each first voltage detection portion 310A includes a first base end portion 312A, a first distal end portion 314A, and a first connection portion 316A.

[0062] The first base end portion 312A is movably supported in the first direction X along the first support shaft 318A provided on the first holding body 300A. Thus, each first voltage detecting portion 310A is held by the first holding body 300A. The first support shaft 318A penetrates the through-hole provided in the first base end portion 312A in the first direction X. The diameter of the front end portion of the first support shaft 318A in a direction perpendicular to the first direction X is larger than the diameter of the through-hole of the first base end portion 312A in a direction perpendicular to the first direction X. Therefore, the first base end portion 312A is prevented from falling off the first support shaft 318A toward the front of the first support shaft 318A.

[0063] In this embodiment, when viewed from the front of the cell stack 10, the first front end portion 314A is located horizontally and vertically offset from the first base end portion 312A. Specifically, when viewed from the front of the cell stack 10, the first front end portion 314A is located to the lower right of the first base end portion 312A. Thus, a gap is provided to the right of the first base end portion 312A and above the first front end portion 314A, exposing a portion of the front surface of the lead portion 110 to the front. Therefore, at least a portion of the joint, such as a laser weld, between the positive lead 112 and the negative lead 114 can be provided in an area of ​​the lead portion 110 that overlaps with this gap and the first direction X. In other words, this joint of the lead portion 110 does not need to overlap with the first front end portion 314A in the first direction X. Therefore, in this embodiment, for example, compared to a case where the first distal end portion 314A is positioned to the right of the first proximal end portion 312A without deviating downward from the first proximal end portion 312A, the vertical length of the joint portion of the lead portion 110 can be increased. Therefore, in this embodiment, compared to the above-described case, the connection between the positive lead 112 and the negative lead 114 in the lead portion 110 can be improved.

[0064] Furthermore, in this embodiment, the first tip portion 314A is positioned offset relative to the first base portion 312A, toward the side where the lead portion 110 is located. Therefore, in this embodiment, compared to a case where the position of the first base portion 312A and the position of the first tip portion 314A in the first direction X are aligned in the first direction X, the first tip portion 314A can be more easily brought close to the lead portion 110, making it easier for the first tip portion 314A to connect to the lead portion 110. Furthermore, in this embodiment, compared to the aforementioned case, the range of motion of the first base portion 312A in the first direction X can be increased.

[0065] The first connection portion 316A protrudes downward from the first base end portion 312A. One end of the first voltage detection line 320A is connected to the first connection portion 316A. The first connection portion 316A may be integrated with the first base end portion 312A, for example. Figure 6As shown, in this embodiment, the first connecting portion 316A includes two first tubular members 316aA to which one end of the first voltage detection line 320A is riveted. The two first tubular members 316aA are arranged in a vertical direction. One end of the first voltage detection line 320A enters the interior space of the two first tubular members 316aA from below, substantially parallel to the vertical direction, and is riveted through the two first tubular members 316aA. Thus, one end of the first voltage detection line 320A is fixed to the first connecting portion 316A. However, the method of fixing one end of the first voltage detection line 320A to the first connecting portion 316A is not limited to the method described in this embodiment. For example, the number of first tubular members 316aA provided in each first connecting portion 316A may be only one. Alternatively, one end of the first voltage detection line 320A may be soldered to the first connecting portion 316A.

[0066] The shape of the first voltage detection portion 310A is not limited to that of this embodiment, as long as the first tip portion 314A does not overlap with the junction between the positive lead 112 and the negative lead 114 in the lead portion 110 in the first direction X. For example, when viewed from the front of the single-unit stack 10, the gap may not be provided to the right of the first base portion 312A and above the first tip portion 314A. Furthermore, the position of the first base portion 312A in the first direction X and the position of the first tip portion 314A in the first direction X may be aligned in the first direction X.

[0067] Each of the plurality of first voltage detection portions 310A is connected to a respective one of the plurality of lead portions 110 at the front of the cell stack 10. Specifically, each first front end portion 314A is joined to each lead portion 110 at the front of the cell stack 10 by a joining method such as laser welding. In this embodiment, the rear surface of the first front end portion 314A is joined to the front surface of the junction between the positive lead 112 and the negative lead 114 of the lead portion 110. The first front end portion 314A preferably comprises the same material as the portion of the lead portion 110 that contacts the first front end portion 314A. In this embodiment, the first front end portion 314A contacts the negative lead 114. In this example, the first front end portion 314A is easier to join to the negative lead 114 than in a case where the first front end portion 314A comprises a different material from that of the negative lead 114. In another example, the first tip portion 314A may include a material different from that of the portion of the lead portion 110 that contacts the first tip portion 314A.

[0068] Each of the plurality of first voltage detection lines 320A electrically connects each of the plurality of first voltage detection units 310A to the first connector 330A. As described above, one end of each first voltage detection line 320A is connected to the first connector 316A. The other end of each first voltage detection line 320A is connected to the first connector 330A. In this embodiment, a portion of each first voltage detection line 320A is led out from the first connector 316A to the space below the first frame 340A via a notch 350A (described later) provided in the first frame 340A. The notch 350A is provided at a corner between the second edge 344A and the third edge 346A (described later) of the first frame 340A. The other portion of each first voltage detection line 320A passes through the space between adjacent first frames 340A in an area offset to the right from the center of the first holding body 300A, and is led out from the space below the plurality of first frames 340A to the first connector 330A located above the plurality of first frames 340A. The position of the first voltage detection unit 310A, the arrangement of the first voltage detection lines 320A, the position of the notch 350A, and the position of the first connector 330A are not limited to those described in this embodiment.

[0069] In this embodiment, at least a portion of the first voltage detection line 320A located between the first connecting portion 316A and the notch 350A is flexible. When the first base end portion 312A is moved along the first support axis 318A in the first direction X, the first voltage detection line 320A may come into contact with the first retaining member 300A or the first frame 340A near the notch 350A. Even in such a situation, the first base end portion 312A can be moved along the first support axis 318A in the first direction X by flexing at least this portion of the first voltage detection line 320A.

[0070] The first retaining body 300A includes a plurality of first frames 340A. The first frames 340A are insulators. Resins such as polypropylene, polybutylene terephthalate, and modified polyphenylene ether, or resins having equivalent or higher hardness, heat resistance, and insulation properties, are used as insulators. The plurality of first frames 340A each surround each of the plurality of lead portions 110 and each of the plurality of first voltage detection portions 310A. Therefore, the first frames 340A protect the lead portions 110 and the first voltage detection portions 310A from external impacts. Each first frame 340A may not be located entirely within the region surrounding each lead portion 110 and each first voltage detection portion 310A. Each first frame 340A may be located within at least a portion of the region surrounding each lead portion 110 and each first voltage detection portion 310A. The first retaining body 300A may be composed of a single component or a plurality of components combined together.

[0071] Each first frame 340A includes a first edge 342A, a second edge 344A, a third edge 346A, and a fourth edge 348A. The first edge 342A extends vertically to the right of the lead portion 110 and the first voltage detection unit 310A enclosed by each first frame 340A. The second edge 344A extends vertically to the left of the lead portion 110 and the first voltage detection unit 310A enclosed by each first frame 340A. The third edge 346A extends horizontally below the lead portion 110 and the first voltage detection unit 310A enclosed by each first frame 340A. The fourth edge 348A extends horizontally above the lead portion 110 and the first voltage detection unit 310A enclosed by each first frame 340A.

[0072] The shape of the first frame 340A is not limited to that of this embodiment. For example, the first frame 340A may not include either the first edge 342A or the second edge 344A. Furthermore, the first frame 340A may not include at least one of the third edge 346A or the fourth edge 348A.

[0073] In this embodiment, at least a portion of the insulator constituting each first frame 340A is positioned between the first voltage detecting portion 310A surrounded by each first frame 340A and a lead portion 110 different from the lead portion 110 connected to the first voltage detecting portion 310A. Therefore, in this embodiment, electrical insulation can be ensured between the first voltage detecting portion 310A surrounded by each first frame 340A and a lead portion 110 different from the lead portion 110 connected to the first voltage detecting portion 310A.

[0074] Specifically, excluding the first frame 340A located at the rightmost end, at least a portion of the insulator constituting the first edge portion 342A is located between the first voltage detection portion 310A located to the left of the first edge portion 342A and the lead portion 110 located to the right of the first edge portion 342A. Therefore, compared to a case where the first edge portion 342A is not provided, electrical insulation is ensured between the first voltage detection portion 310A located to the left of the first edge portion 342A and the lead portion 110 located to the right of the first edge portion 342A.

[0075] Furthermore, excluding the first frame 340A located at the leftmost end, at least a portion of the insulator constituting the second edge portion 344A is located between the first voltage detection portion 310A located to the right of the second edge portion 344A and the lead portion 110 located to the left of the second edge portion 344A. Therefore, compared to a case where the second edge portion 344A is not provided, electrical insulation is ensured between the first voltage detection portion 310A located to the right of the second edge portion 344A and the lead portion 110 located to the left of the second edge portion 344A.

[0076] In this embodiment, at least a portion of the insulator constituting each first frame 340A is located between different lead portions 110. Specifically, at least a portion of the insulator constituting each first frame 340A is located between adjacent lead portions 110. Therefore, compared to a case where at least a portion of the insulator constituting each first frame 340A is not located between different lead portions 110, electrical insulation between different lead portions 110 can be ensured.

[0077] Specifically, with the exception of the first frame 340A located at the rightmost end, at least a portion of the insulator constituting the first edge portion 342A is located between the lead portion 110 located to the left of the first edge portion 342A and the lead portion 110 located to the right of the first edge portion 342A. Therefore, compared to a case where the first edge portion 342A is not provided, electrical insulation is ensured between the lead portion 110 located to the left of the first edge portion 342A and the lead portion 110 located to the right of the first edge portion 342A.

[0078] Furthermore, excluding the first frame 340A located at the leftmost end, at least a portion of the insulator constituting the second edge portion 344A is located between the lead portion 110 located to the right of the second edge portion 344A and the lead portion 110 located to the left of the second edge portion 344A. Therefore, compared to a case where the second edge portion 344A is not provided, electrical insulation can be ensured between the lead portion 110 located to the right of the second edge portion 344A and the lead portion 110 located to the left of the second edge portion 344A.

[0079] Furthermore, an insulating protrusion that protrudes toward the positive direction of the first direction X can be provided on the surface of the first frame 340A on the positive side in the first direction X. At least a portion of this protrusion is positioned between adjacent lead portions 110 in the second direction Y. For example, this protrusion can be provided on the positive direction of the first direction X of the first edge portion 342A of the left first frame 340A among adjacent first frames 340A in the second direction Y, and on the positive direction of the first direction X of the second edge portion 344A of the right first frame 340A among adjacent first frames 340A in the second direction Y. In this example, if adjacent lead portions 110 in the second direction Y deviate in the second direction Y due to external impact or other factors, the lead portions 110 will collide with this protrusion. This prevents collision between adjacent lead portions 110 in the second direction Y. The length of this protrusion is not particularly limited, but can be set to a length sufficient to prevent collision between adjacent lead portions 110 in the second direction Y, for example. In addition, the position where the protrusion is provided is not limited to the above-mentioned example.

[0080] In this embodiment, at least a portion of the insulator constituting each first frame 340A is positioned between at least one lead portion 110 and at least one conductive portion of the housing 20. Therefore, in this embodiment, electrical insulation between at least one lead portion 110 and at least one conductive portion of the housing 20 can be ensured.

[0081] Specifically, at least a portion of the third edge portion 346A is located below the lead portion 110 surrounded by each first frame 340A. In the present embodiment, the front end portion of the fifth cover member 250 is located below the lower end portion of the lead portion 110. In the case where the fifth cover member 250 is conductive, if the lower end portion of the lead portion 110 contacts the front end portion of the fifth cover member 250, there is a possibility that the lead portion 110 and the fifth cover member 250 will short-circuit. In contrast, in the present embodiment, at least a portion of the insulator constituting the third edge portion 346A is located between the lower end portion of the lead portion 110 and the front end portion of the fifth cover member 250. Therefore, compared with a case where the third edge portion 346A is not provided, a short circuit between the lead portion 110 and the fifth cover member 250 can be suppressed.

[0082] In the above example, electrical insulation is ensured between the lower end of the lead portion 110 and the front end of the fifth cover member 250 by the third edge portion 346A. However, ensuring electrical insulation between the lead portion 110 and the housing 20 by the first frame 340A is not limited to the above example. For example, electrical insulation can be ensured between the upper end of the lead portion 110 and the front end of the sixth cover member 260 by the fourth edge portion 348A. Furthermore, electrical insulation can be ensured between the right end of the lead portion 110 located at the rightmost end among the plurality of first frames 340A and the front end of the third cover member 230 by the first edge portion 342A of the first frame 340A located at the rightmost end. Furthermore, electrical insulation between the left end of the leftmost lead portion 110 among the plurality of lead portions 110 and the front end of the fourth cover member 240 can be ensured by the second edge portion 344A of the leftmost first frame 340A among the plurality of first frames 340A.

[0083] In this embodiment, the second edge 344A of the first frame 340A surrounding the right lead portion 110 among adjacent lead portions 110 in the second direction Y and the first edge 342A of the first frame 340A surrounding the left lead portion 110 among adjacent lead portions 110 in the second direction Y are located between the lead portions 110 adjacent in the second direction Y. Therefore, the distance in the second direction Y between the adjacent lead portions 110 in the second direction Y needs to be greater than the distance in the second direction Y between the second edge 344A and the first edge 342A located between the adjacent lead portions 110 in the second direction Y. The greater the number of battery cells 100 included in the cell group 100G, the greater the distance in the second direction Y between the adjacent lead portions 110 in the second direction Y. Therefore, when the cell group 100G includes a plurality of battery cells 100 , it is easier to increase the distance in the second direction Y between adjacent lead portions 110 compared to when the cell group 100G includes only one battery cell 100 .

[0084] The second voltage detection device 30B, similar to the first voltage detection device 30A, includes a second holding body 300B, a plurality of second voltage detection units 310B, a plurality of second voltage detection lines 320B, and a second connector 330B.

[0085] The second retaining body 300B is provided at the rear of the cell stack 10. Each of the plurality of second voltage detecting units 310B is connected to a respective one of the plurality of lead units 110 at the rear of the cell stack 10. In this embodiment, the surface of each second voltage detecting unit 310B on the negative side in the first direction X is joined to the surface on the positive side in the first direction X of the junction between the positive lead 112 and the negative lead 114 of the lead unit 110. Each of the plurality of second voltage detecting lines 320B electrically connects each of the plurality of second voltage detecting units 310B to the second connector 330B. The second retaining body 300B is provided with a plurality of second frames 340B. Similar to the plurality of first frames 340A, each of the plurality of second frames 340B surrounds each of the plurality of lead units 110 and each of the plurality of second voltage detecting units 310B at the rear of the cell stack 10.

[0086] Figure 6 It is an enlarged view of a position where a first fuse device 40A is provided in the first voltage detection device 30A according to the embodiment.

[0087] The first fuse device 40A includes a first base 302A, a first conductor 400A, a first fixture 432A, a second fixture 434A, and a first wiring 440A.

[0088] The first base 302A includes the right end portion of the first holding body 300A. In this embodiment, the first base 302A includes two rightmost first frames 340A among the plurality of first frames 340A.

[0089] The first conductor 400A is provided on the first base 302A. The first conductor 400A is made of metal, for example. The first conductor 400A functions as a bus bar electrically connected to the terminal positive lead 112T.

[0090] The first conductor 400A includes a plurality of elongated bodies extending in different directions, and at least a portion of at least one of the plurality of elongated bodies is held by the first base 302A.

[0091] Specifically, the first conductor 400A includes a first extension 410A extending horizontally and a second extension 420A extending vertically. The second extension 420A extends downward from the right end of the first extension 410A. The first extension 410A and the second extension 420A are integrally formed. The first conductor 400A may be formed by combining a metal forming the first extension 410A and a metal forming the second extension 420A, for example. However, the method for forming the first conductor 400A is not limited to this example. Furthermore, the shape of the first conductor 400A is not limited to that described in this embodiment. For example, the first conductor 400A may not include the second extension 420A.

[0092] The first extension 410A includes a first wide portion 412A, a narrow portion 414A, and a second wide portion 416A. The left end of the narrow portion 414A is connected to the right end of the first wide portion 412A. The right end of the narrow portion 414A is connected to the left end of the second wide portion 416A.

[0093] The first wide portion 412A functions as a terminal for electrical connection to other battery modules (not shown). A fastening hole 450A is provided at the left end of the first wide portion 412A. A fastener (not shown) is secured to the fastening hole 450A, for example, for securing a bus bar (not shown) for electrical connection to other battery modules to the first base 302A. In this embodiment, the periphery of the fastening hole 450A in the first wide portion 412A is located higher than the narrow portion 414A. However, the periphery of the fastening hole 450A in the first wide portion 412A may also be located at the same height as the narrow portion 414A. The securing of the bus bar (not shown) in the first wide portion 412A to the first base 302A is not limited to the use of the fastening hole 450A and the fastener. For example, the bus bar (not shown) and the first wide portion 412A may be bonded to each other using an adhesive such as a resin without the fastening hole 450A.

[0094] The narrow portion 414A functions as a fuse. The width of the narrow portion 414A in the first direction X is narrower than either the width of the first wide portion 412A or the width of the second wide portion 416A. Therefore, the cross-sectional area of ​​the narrow portion 414A perpendicular to the second direction Y is smaller than either the cross-sectional area of ​​the first wide portion 412A or the cross-sectional area of ​​the second wide portion 416A. Therefore, when an overcurrent flows through the first conductor 400A, the narrow portion 414A is more likely to melt than the first wide portion 412A or the second wide portion 416A.

[0095] In this embodiment, the narrow width portion 414A is attached to the first holding body 300A. Therefore, compared with a case where a structure for holding the fuse is provided separately from the first holding body 300A, the first voltage detector 310A and the fuse can be provided more efficiently in space.

[0096] Furthermore, in this embodiment, the battery module 50 can be miniaturized compared to using a tubular fuse as a fuse. Specifically, when using a tubular fuse, the higher the energy of the battery module 50, the larger the tubular fuse. Therefore, in a battery module 50 with a relatively high energy, the space required to install the tubular fuse is relatively large. In contrast, when a portion of the first conductor 400A functions as a fuse, the space required to install the fuse can be reduced compared to using a tubular fuse.

[0097] In this embodiment, the narrow portion 414A extends in the same direction as the first wide portion 412A. That is, the first wide portion 412A and the narrow portion 414A extend in the second direction Y. If the narrow portion 414A were provided on the second extension 420A and extended in a direction perpendicular to the direction in which the first wide portion 412A extends, it would be difficult to join the narrow portion 414A provided on the second extension 420A with the terminal positive lead 112T. In contrast, in this embodiment, the narrow portion 414A is not required on the second extension 420A. Therefore, in this embodiment, the length of the junction between the second extension 420A and the terminal positive lead 112T in the third direction Z can be increased compared to the above-described embodiment. Furthermore, in this embodiment, the length of the narrow portion 414A in the second direction Y can be adjusted more easily than in the above-described embodiment. Furthermore, in this embodiment, the narrow portion 414A and the terminal positive lead 112T can be further apart than in the above-described case. Therefore, in this embodiment, the effect of heat generated by the narrow portion 414A on the terminal positive lead 112T can be suppressed compared to the above-described case.

[0098] A first space 402A is provided in front of the narrow portion 414A of the first extension 410A. In this embodiment, the first space 402A is formed by punching out the front portion of the conductor constituting the first extension 410A, which will become the narrow portion 414A.

[0099] There is no space defining the narrow portion 414A behind the narrow portion 414A in the first extension 410A. However, the method for forming the narrow portion 414A is not limited to the method involved in this embodiment. For example, the first space 402A may be provided behind the narrow portion 414A. Alternatively, the first space 402A may be provided both in front of and behind the narrow portion 414A. In addition, the first space 402A may be formed by a through hole penetrating the first extension 410A in the vertical direction. In this case, the portions on both sides of the first direction X of the first space 402A in the first extension 410A become the narrow portion 414A that functions as a fuse.

[0100] When forming the narrow portion 414A by press working, it is preferable to provide a space defining the narrow portion 414A only on one of the two sides of the first extension 410A in the first direction X, as in the present embodiment. In this case, the rear portion of the conductor constituting the first extension 410A, which will become the narrow portion 414A, does not need to be punched out by press working. Compare this embodiment with a case where both the front and rear portions of the conductor constituting the first extension 410A, which will become the narrow portion 414A, are punched out by press working. In this case, compared to the present embodiment, since both the front and rear portions of the conductor constituting the first extension 410A need to be punched out simultaneously or individually, the mechanical load applied to the narrow portion 414A, which is the narrowest width of the first extension 410A, during press working increases. Therefore, in this case, compared to the present embodiment, to prevent the narrow portion 414A from breaking, the width of the narrow portion 414A in the first direction X needs to be increased. In contrast, in the present embodiment, the width of the narrow portion 414A in the first direction X can be further narrowed compared to the above-described case, and the degree of freedom in the size of the narrow portion 414A can be increased.

[0101] Furthermore, the method for forming the narrow portion 414A is not limited to press working. The narrow portion 414A may also be formed, for example, by laser processing. When the narrow portion 414A is formed by laser processing, the space defining the narrow portion 414A may be provided on only one of the two sides of the first extension body 410A in the first direction X, or may be provided on both sides of the first extension body 410A in the first direction X.

[0102] A second space 304A is provided below the narrow portion 414A. The second space 304A is defined by a recessed portion provided on the upper surface of the first base 302A, on which the first extension 410A is placed. In this embodiment, if an overcurrent flows through the first conductor 400A and the narrow portion 414A melts, the melted narrow portion 414A can fall into the second space 304A. Therefore, according to this embodiment, the accuracy of melting the narrow portion 414A can be improved compared to a case where the lower surface of the narrow portion 414A contacts the upper surface of the first base 302A.

[0103] In this embodiment, at least a portion of narrow portion 414A is located above at least one of positive lead 112 and negative lead 114. Furthermore, at least a portion of first base 302A is located between at least one of positive lead 112 and negative lead 114 and at least a portion of narrow portion 414A in the third direction Z. Specifically, the portion defining the bottom of the recessed portion in first base 302A is located between at least one of positive lead 112 and negative lead 114 and at least a portion of narrow portion 414A in the third direction Z. This prevents the melted narrow portion 414A from contacting the positive lead 112 or negative lead 114 located below the narrow portion 414A.

[0104] The portion of the first base 302A located above at least one of the positive lead 112 and the negative lead 114 may be heat-resistant. For example, a heat-resistant layer may be provided on the bottom surface of the recessed portion of the first base 302A. The heat-resistant layer may be made of metal or an inorganic material such as ceramic or glass. By providing a heat-resistant layer, it is possible to more reliably prevent the molten narrow portion 414A from melting the main body of the first base 302A and coming into contact with the positive lead 112, the negative lead 114, or the first wiring 440A. The first base 302A is not limited to the above-mentioned portion; the first base 302A may also have heat resistance around the narrow portion 414A. For example, the melting point of the first base 302A around the narrow portion 414A may be above 200°C.

[0105] The first wide portion 412A is secured to the first base 302A via a first fixing member 432A. In this embodiment, the first fixing member 432A is a screw that vertically penetrates the first wide portion 412A and is inserted into the portion of the first base 302A located below the first wide portion 412A. A through-hole is provided in the first wide portion 412A through which the shaft of the first fixing member 432A can be vertically inserted. The first fixing member 432A may also be a fixing member other than a screw, such as a screw or bolt.

[0106] The second wide portion 416A is secured to the first base 302A via a second fixing member 434A. In this embodiment, the second fixing member 434A is a screw that vertically penetrates the second wide portion 416A and is inserted into the portion of the first base 302A below the second wide portion 416A. A through-hole is provided in the second wide portion 416A through which the shaft of the second fixing member 434A can be vertically inserted. The second fixing member 434A may also be a fixing member other than a screw, such as a screw or bolt.

[0107] In the embodiment, the first extension 410A and the first base 302A are integrally fixed to each other by the first fixing member 432A and the second fixing member 434A. Therefore, the rigidity of the first extension 410A can be improved compared to a case where the first extension 410A is used independently without being fixed to the first base 302A.

[0108] In this embodiment, the first fixture 432A, the second fixture 434A, and other fixtures are detachable from the first conductor 400A. Therefore, if the narrow portion 414A melts and the first conductor 400A needs to be replaced, the first conductor 400A can be replaced with a new one by removing the first fixture 432A, the second fixture 434A, and other fixtures.

[0109] The method of fixing the first conductor 400A to the first base 302A is not limited to the above example. For example, at least a portion of the first conductor 400A may be joined to at least a portion of the first base 302A via mechanical joints such as snap fasteners.

[0110] In this embodiment, both the first wide portion 412A and the second wide portion 416A are fixed to the first base 302A via a first fixing member 432A and a second fixing member 434A. In this case, compared to a case where at least one of the first wide portion 412A and the second wide portion 416A is not fixed to the first base 302A, the force that could cause the narrow portion 414A to break can be suppressed. For example, when a bus bar (not shown) is attached to the first wide portion 412A to electrically connect the battery module 50 to another battery module (not shown), a force that could cause the narrow portion 414A to break is generated when a fixing member (not shown) is fixed to the fastening hole 450A. This is because the fastening hole 450A and the narrow portion 414A are located in approximately the same plane, perpendicular to the third direction Z.

[0111] The first fixing member 432A and the second fixing member 434A are preferably disposed near the narrow width portion 414A. For example, the first fixing member 432A and the second fixing member 434A are preferably provided at positions facing each other across the first space 402A.

[0112] In this embodiment, at least a portion of the first wiring 440A passes through the first space 402A. In this case, the first wiring 440A can be spatially efficiently arranged compared to a case where the first wiring 440A passes through a region different from the first space 402A.

[0113] Furthermore, in this embodiment, at least a portion of the first wiring 440A passes through a portion of the first base 302A that is horizontally offset from the portion below the narrow portion 414A. In this embodiment, a through-hole for the first wiring 440A to pass through is provided in the bottom surface of the recessed portion defining the second space 304A in the first base 302A. This through-hole is located on the negative side in the first direction X relative to the area directly below the narrow portion 414A. This prevents the narrow portion 414A, which melts and falls into the second space 304A, from coming into contact with the first wiring 440A.

[0114] The first wiring 440A has one end connected to the second wide portion 416A; Figure 3 The other end of the first wiring 440A is connected to the first connector 330A shown. A portion of the first wiring 440A is led downward from the end of the first wiring 440A connected to the second wide portion 416A, passing through the first space 402A and the second space 304A. Another portion of the first wiring 440A passes through the portion of the first base 302A located below the second space 304A and the area between the two rightmost first frames 340A, leading to the space below the multiple first frames 340A. Yet another portion of the first wiring 440A passes through the space between adjacent first frames 340A in an area offset to the right from the center of the first retaining body 300A, leading from the space below the multiple first frames 340A to the first connector 330A located above the multiple first frames 340A. The layout of the first wiring 440A is not limited to the example described in this embodiment.

[0115] In this embodiment, the end of the first wiring 440A connected to the second wide portion 416A is fixed to the second wide portion 416A via a second fixing member 434A. In this embodiment, compared to a case where the end of the first wiring 440A is fixed to the second wide portion 416A via solder, for example, this facilitates attachment and detachment of the first wiring 440A when the narrow portion 414A is blown. Alternatively, a connecting component such as a crimping terminal may be provided at the end of the first wiring 440A. In this case, by fixing the connecting component with the second fixing member 434A, the end of the first wiring 440A can be fixed to the second wide portion 416A. However, the method of connecting the end of the first wiring 440A to the second wide portion 416A is not limited to this example.

[0116] Furthermore, in this embodiment, the second fixture 434A secures both the second wide portion 416A and the end of the first wiring 440A connected to the second wide portion 416A to the first base 302A. In this case, the number of components can be reduced compared to a case where separate fixtures are provided for securing the second wide portion 416A to the first base 302A and for securing the aforementioned end of the first wiring 440A to the first base 302A. In other examples different from this embodiment, separate fixtures may be provided for securing the second wide portion 416A to the first base 302A and for securing the aforementioned end of the first wiring 440A to the first base 302A.

[0117] The portion of the second wide portion 416A where the second fixing member 434A is located functions as a voltage detection unit that detects the voltage of the terminal positive lead 112T. Specifically, the portion of the second wide portion 416A where the second fixing member 434A is located serves as the target for voltage detection. The first wiring 440A functions as a voltage detection line electrically connected to this voltage detection unit. In this embodiment, the end of the first wiring 440A fixed by the second fixing member 434A is electrically connected to the second wide portion 416A. In this case, compared to a case where the first wiring 440A is electrically connected to the first wide portion 412A, the voltage of the terminal positive lead 112T can be detected while minimizing the influence of the voltage drop in the narrow portion 414A. Consequently, the voltage of the terminal positive lead 112T can be detected more accurately.

[0118] exist Figure 3 as well as Figure 6 In the embodiment, the second extension 420A is electrically connected to the terminal positive lead 112T. In this embodiment, the right side of the second extension 420A and the left side of the terminal positive lead 112T are joined together by a joining method such as laser welding. Alternatively, the second extension 420A may be omitted. Even if the second extension 420A is omitted, the terminal positive lead 112T and the first extension 410A can be electrically connected via an L-shaped bus bar (not shown).

[0119] At least a portion of the second extension 420A is held by at least a portion of the first base 302A. In this embodiment, the upper end of the first extension 410A is held by both side surfaces in the second direction Y of a through-hole in the first base 302A through which the upper end of the first extension 410A extends. Furthermore, the lower end of the second extension 420A is held by both side surfaces in the second direction Y of a hole in the first base 302A into which the lower end of the second extension 420A is inserted. This embodiment is preferred because it suppresses the application of a force that would cause the narrow portion 414A to rotate perpendicular to the vertical direction, compared to a case where the second extension 420A is not held by the first base 302A. Consequently, it further suppresses breakage of the narrow portion 414A compared to a case where the second extension 420A is not held by the first base 302A.

[0120] Figure 7 It is a top view of the first conductor 400A according to the embodiment.

[0121] exist Figure 7 In the figure, the white circle with black dots representing the third direction Z indicates that the direction from the depth of the paper to the front is the positive direction of the third direction Z, and the direction from the front of the paper to the depth is the negative direction of the third direction Z.

[0122] In this embodiment, the first conductor 400A is designed so that the external short-circuit current density in each battery cell 100 is 350 A / mm 2 Above and 900A / mm 2 The external short-circuit current density is the current per unit cross-sectional area of ​​the fuse that flows when an external short circuit occurs in the battery.

[0123] When viewed from the third direction Z, the first extension 410A includes a first bend 404A extending from the outer edge of the narrow portion 414A to the outer edge of the first wide portion 412A. Specifically, when viewed from the third direction Z, the first bend 404A is located at the inner corner between the outer edge of the front side of the narrow portion 414A and the outer edge of the right side of the first wide portion 412A. In one example, the first bend 404A is formed by punching the first conductor 400A used to form the narrow portion 414A. The radius of curvature R1 of the first bend 404A can be adjusted by adjusting the punching process of the first conductor 400A. The inner corner between the outer edge of the front side of the narrow portion 414A and the outer edge of the right side of the first wide portion 412A does not have to be completely curved, but may partially include a straight line.

[0124] In one example, when viewed from the third direction Z, the first curve 404A has an arc shape with a curvature radius R1 of 1.0 mm to 3.0 mm.

[0125] When the radius of curvature R1 is greater than the lower limit of the aforementioned exemplary range, the mechanical strength of the narrow portion 414A can be improved by distributing stress around the first bend 404A of the first conductor 400A and its surroundings, compared to when the radius of curvature R1 is less than the lower limit of the aforementioned exemplary range. Specifically, when the radius of curvature R1 is greater than the lower limit of the aforementioned exemplary range, compared to when the radius of curvature R1 is less than the lower limit of the aforementioned exemplary range, even if torque is generated around the first bend 404A of the first conductor 400A when a bus bar (not shown) is secured to the fastening hole 450A using a fastener (not shown), plastic deformation around the first bend 404A of the first conductor 400A can be suppressed. When the bus bar is secured to the fastening hole 450A using a fastener, a torque of, for example, 5.0 Nm or more and 15 Nm or less may be generated around the first bend 404A of the first conductor 400A.

[0126] When the curvature radius R1 is below the upper limit of the aforementioned exemplary range, the narrow portion 414A of the first conductor 400A, caused by current concentration around the first bend 404A and its surroundings, is more likely to melt than when the curvature radius R1 is greater than the upper limit of the aforementioned exemplary range, allowing the narrow portion 414A to function properly as a fuse. For example, when the battery module 50 has a relatively high capacity of 50 kWh or greater, the current flowing through the narrow portion 414A around the first bend 404A is more stable when the curvature radius R1 is below the upper limit of the aforementioned exemplary range than when the curvature radius R1 is greater than the upper limit of the aforementioned exemplary range.

[0127] When viewed from the third direction Z, the first bend 404A does not need to be an arc shape. When viewed from the third direction Z, the first bend 404A may at least partially include a curved shape passing through a region surrounded by the following outlines: the outline of the first bend 404A when the first bend 404A is an arc shape with a curvature radius of 1.0 mm, and the outline of the first bend 404A when the first bend 404A is an arc shape with a curvature radius of 3.0 mm. When the first bend 404A at least partially includes this curved shape, the first conductor 400A can be manufactured more easily without compromising the strength of the first conductor 400A or the function of the narrow portion 414A as a fuse, compared to when the first bend 404A is an arc shape with a curvature radius R1 of either 1.0 mm or more and 3.0 mm or less.

[0128] When the first bend 404A at least partially includes the aforementioned curved shape, even if torque is generated around the first bend 404A of the first conductor 400A when the bus bar (not shown) is secured to the fastening hole 450A using a fixture (not shown), plastic deformation around the first bend 404A of the first conductor 400A can be suppressed. Furthermore, when the first bend 404A at least partially includes the aforementioned curved shape, current concentration in and around the first bend 404A of the first conductor 400A facilitates melting of the narrow portion 414A, allowing the narrow portion 414A to function properly as a fuse.

[0129] When viewed from the third direction Z, the first extension 410A includes a second bend 406A extending from the outer edge of the narrow portion 414A to the outer edge of the second wide portion 416A. Specifically, when viewed from the third direction Z, the second bend 406A is located at the inner corner between the outer edge of the front side of the narrow portion 414A and the outer edge of the left side of the second wide portion 416A. In one example, the second bend 406A is formed by punching the first conductor 400A used to form the narrow portion 414A. The curvature radius R2 of the second bend 406A can be adjusted by adjusting the punching process of the first conductor 400A. When viewed from the third direction Z, the second bend 406A can be configured to have an arc shape with a curvature radius R2 within the same range as the curvature radius R1 of the arc shape of the first bend 404A. The curvature radius R2 of the second bend 406A can be equal to or different from the curvature radius R1 of the first bend 404A. When viewed from the third direction Z, the second bend 406A may at least partially include the same curved shape as the aforementioned curved shape of the first bend 404A.

[0130] The cross-sectional area S of the narrow width portion 414A perpendicular to the second direction Y is preferably 40 mm, for example. 2 Above and 100mm 2 , more preferably 50mm 2 Above and 90mm 2 The range of cross-sectional area S is determined, for example, according to the value of the overcurrent that causes the narrow width portion 414A to melt. That is, when the cross-sectional area S is greater than the lower limit of the range, the value of the overcurrent that causes the narrow width portion 414A to melt becomes larger than when the cross-sectional area S is less than the lower limit of the range. On the other hand, when the cross-sectional area S is less than the upper limit of the range, the value of the overcurrent that causes the narrow width portion 414A to melt becomes smaller than when the cross-sectional area S is greater than the upper limit of the range. Furthermore, when the cross-sectional area S is greater than the lower limit of the range, the fracture of the narrow width portion 414A due to external force can be suppressed compared to when the cross-sectional area S is less than the lower limit of the range.

[0131] The length L of the narrow width portion 414A in the second direction Y is preferably, for example, not less than 10 cm and not more than 25 cm, and more preferably not less than 15 cm and not more than 20 cm. Figure 7 In the example shown, the length L is the length including the first bend 404A and the second bend 406A. The range of the length L is determined, for example, according to the value of the overcurrent that causes the narrow width portion 414A to melt. When the length L is greater than the lower limit of the range, the amount of overcurrent that causes the narrow width portion 414A to melt is smaller than when the length L is less than the lower limit of the range. On the other hand, when the length L is less than the upper limit of the range, the amount of overcurrent that causes the narrow width portion 414A to melt is greater than when the length L is greater than the upper limit of the range. Furthermore, when the length L is less than the upper limit of the range, the rupture of the narrow width portion 414A due to external force can be suppressed compared to when the length L is greater than the upper limit of the range.

[0132] The time it takes for the narrow width portion 414A to melt when an overcurrent flows is not particularly limited. In one example, the time it takes for the narrow width portion 414A to melt when an overcurrent of 7000 A or more flows can be set to 0.05 seconds to 0.3 seconds.

[0133] In the embodiment, two bends, a first bend 404A and a second bend 406A, are provided on both sides of the narrow portion 414A in the second direction Y. However, the first conductor 400A may include only one of the first bend 404A and the second bend 406A. In this case, the inner corner of the other of the first conductor 400A including the first bend 404A and the second bend 406A may be, for example, substantially a right angle when viewed from the third direction Z.

[0134] Figure 8 1 is a top view of a first conductor 400A1 according to a modification. The first conductor 400A1 according to the modification is the same as the first conductor 400A according to the embodiment except for the following points.

[0135] When viewed from the third direction Z, the narrow width portion 414A1 may be inclined obliquely relative to the first direction X. Figure 8 In the example shown, the left end of the narrow portion 414A1 is connected to the rear end of the right end of the first wide portion 412A1. The right end of the narrow portion 414A1 is connected to the front end of the left end of the second wide portion 416A1. The length of the narrow portion 414A1 in the modified example is, for example, 15 cm to 20 cm. The length of the narrow portion 414A1 in the modified example refers to the length of the portion of the narrow portion 414A1 where the width is constant.

[0136] When viewed from the third direction Z, the first extension 410A1 includes a first bend 404A1 extending from the outer edge of the narrow portion 414A1 to the outer edge of the first wide portion 412A1. When viewed from the third direction Z, the first bend 404A1 is located at the inner corner between the outer edge of the front side of the narrow portion 414A1 and the outer edge of the right side of the first wide portion 412A1. The first bend 404A1 is formed by punching the first conductor 400A1 used to form the narrow portion 414A1. The radius of curvature R1 of the first bend 404A1 can be adjusted by adjusting the punching process of the first conductor 400A1. The radius of curvature R1 of the arc shape of the first bend 404A1 according to the modified example can be set within the same range as the radius of curvature R1 of the arc shape of the first bend 404A according to the embodiment. The first bend 404A1 according to the modification may at least partially include the same curved shape as the curved shape of the first bend 404A described in the embodiment.

[0137] When viewed from the third direction Z, the first extension 410A1 includes a second bend 406A1 extending from the outer edge of the narrow portion 414A1 to the outer edge of the second wide portion 416A1. When viewed from the third direction Z, the second bend 406A1 is located at the inner corner between the outer edge of the rear side of the narrow portion 414A1 and the outer edge of the left side of the second wide portion 416A1. The second bend 406A1 is formed by punching the first conductor 400A1 used to form the narrow portion 414A1. The radius of curvature R1 of the second bend 406A1 can be adjusted by adjusting the punching process of the first conductor 400A1. The radius of curvature R2 of the arc shape of the second bend 406A1 according to the modified example can be set to the same range as the radius of curvature R2 of the arc shape of the second bend 406A according to the embodiment. The second bend 406A1 according to the modification may at least partially include the same curved shape as the curved shape of the second bend 406A described in the embodiment.

[0138] As mentioned above, although embodiment and modification of this invention were described with reference to drawings, these are illustrations of this invention, and various structures other than the above-mentioned can be adopted.

[0139] For example, the first fuse device 40A according to the embodiment is electrically connected to the battery cell 100. However, the first fuse device 40A may be electrically connected to an electronic device other than the battery cell 100. The same applies to the second fuse device 40B.

[0140] This application claims the benefit of priority based on Japanese patent application No. 2023-025994, filed on February 22, 2023, the disclosure of which is incorporated herein in its entirety.

[0141] Description of Reference Signs

[0142] 10: Cell stack, 20: Housing, 30A: First voltage detection device, 30B: Second voltage detection device, 40A: First fuse device, 40B: Second fuse device, 50: Battery module, 100: Battery cell, 100G: Cell group, 102: Exterior component, 104: Adhesive member, 110: Lead portion, 112: Positive electrode lead, 112T: Terminal positive electrode lead, 114: Negative electrode lead, 114T: Terminal negative electrode lead, 210 : 1st cover member, 220: 2nd cover member, 230: 3rd cover member, 240: 4th cover member, 250: 5th cover member, 260: 6th cover member, 300A: 1st holding body, 300B: 2nd holding body, 302A: 1st base, 304A: 2nd space, 310A: 1st voltage detection part, 310B: 2nd voltage detection part, 312A: 1st base end part, 314A: 1st front end part, 316A: 1st connecting part, 316aA : 1st tubular member, 318A: 1st supporting shaft, 320A: 1st voltage detection line, 320B: 2nd voltage detection line, 330A: 1st connector, 330B: 2nd connector, 340A: 1st frame, 340B: 2nd frame, 342A: 1st edge, 344A: 2nd edge, 346A: 3rd edge, 348A: 4th edge, 350A: notch, 400A: 1st conductor, 402A: 1st space, 404A, 404 A1: 1st bend, 406A, 406A1: 2nd bend, 410A, 410A1: 1st extension, 412A, 412A1: 1st wide portion, 414A, 414A1: narrow portion, 416A, 416A1: 2nd wide portion, 420A: 2nd extension, 432A: 1st fixing member, 434A: 2nd fixing member, 440A: 1st wiring, 450A: fastening hole, X: 1st direction, Y: 2nd direction, Z: 3rd direction.

Claims

1. A fuse device, characterized in that: have: The first conductor portion functions as a fuse; and a second conductor portion electrically connected to the first conductor portion and having a cross-sectional area larger than that of the first conductor portion; A bend is provided from the outer edge of the first conductor portion to the outer edge of the second conductor portion.

2. The fuse device according to claim 1, wherein The bend is provided at an inner corner extending from the outer edge of the first conductor portion to the outer edge of the second conductor portion. The curvature of the inner corner portion is in an arc shape with a curvature radius of 1.0 mm to 3.0 mm.

3. The fuse device according to claim 1, wherein The bend is provided at an inner corner extending from the outer edge of the first conductor portion to the outer edge of the second conductor portion. The curvature of the inner corner is at least partially included in a curved shape passing through an area surrounded by the following contours: the contour of the curvature when the curvature is an arc shape with a curvature radius of 1.0 mm, and the contour of the curvature when the curvature is an arc shape with a curvature radius of 3.0 mm.

4. The fuse device according to claim 1, wherein The cross-sectional area of ​​the first conductor is 40 mm 2 Above and 100mm 2 the following.

5. A battery module, characterized in that: have: The fuse device according to any one of claims 1 to 4; and At least one battery cell is electrically connected to the fuse device.

Images