Voltage detection device and battery module

Abstract

A first voltage detection device (200) is provided with a first harness (210) for detecting the voltage of a battery cell (100), and a first protector (220) for at least partially holding the first harness (210). The first protector (220) has a first block (222) and a second block (224) that are movably secured to each other.

Description

Voltage detection device and battery module

[0001] The present invention relates to a voltage detection device and a battery module.

[0002] Recently, battery modules have been developed, which may include battery cells and a voltage detection device configured to detect the voltage of the battery cells.

[0003] Patent Document 1 describes a battery pack having a movable busbar assembly, which has connecting busbars for connecting submodules, each including one or more unit cells, in series.

[0004] Special Publication No. 2022-512496

[0005] In a battery module, errors may occur between the actual dimensions, positions, etc. of components arranged around the voltage detection device, such as battery cells and the housing that houses the battery cells, and the design values ​​of the dimensions, positions, etc. of the components. Therefore, there may be a demand for improving the ability of the voltage detection device to conform to the shape of the components arranged around the voltage detection device.

[0006] One example of an object of the present invention is to improve the ability of a voltage detection device to conform to the shape of a member arranged around the voltage detection device. Other objects of the present invention will become apparent from the description of this specification.

[0007] One aspect of the present invention is as follows: 1. A voltage detection device comprising: a voltage detection unit for detecting the voltage of a battery cell; and a holder that at least partially holds the voltage detection unit, wherein the holder has a plurality of parts that are fixed so as to be movable relative to one another. 2. The voltage detection device described in 1., wherein the holder has a structure for restricting movement of the plurality of parts. 3. The voltage detection device described in 1. or 2., wherein the holder has a structure for aligning the plurality of parts relative to one another. 4. The voltage detection device described in any one of 1. to 3., wherein the voltage detection unit is arranged at least partially offset in a predetermined direction, and the plurality of parts are aligned in the predetermined direction. 5. A battery module comprising the battery cell and the voltage detection device described in any one of 1. to 4.

[0008] According to the above aspect of the present invention, it is possible to improve the ability of the voltage detection device to conform to the shape of the members arranged around the voltage detection device.

[0009] 1 is an exploded perspective view of a battery module according to an embodiment; FIG. 2 is an exploded perspective view of a first voltage detection device according to an embodiment with a first harness and a first bus bar removed; FIG. 3 is an enlarged view of a portion of a first block according to an embodiment; FIG. 4 is an enlarged view of a portion of a second block according to an embodiment; FIG. 5 is an exploded perspective view of a portion of a first voltage detection device according to a first modified example; FIG. 6 is a front view of a portion of a first protector according to a first modified example with the first block and the second block assembled to each other; FIG. 7 is an exploded perspective view of a portion of a first voltage detection device according to a second modified example;

[0010] Hereinafter, embodiments and modifications of the present invention will be described with reference to the drawings. In all the drawings, similar components are designated by similar reference numerals, and descriptions thereof will be omitted as appropriate.

[0011] FIG. 1 is an exploded perspective view of a battery module 10 according to an embodiment.

[0012] For the purpose of explanation, the X direction, Y direction, and Z direction are shown in FIG. 1 and subsequent figures. The X direction indicates the front-to-rear direction of the battery module 10. The Y direction is one of the directions perpendicular to the X direction. The Y direction indicates the left-to-right direction of the battery module 10. The Z direction is a direction perpendicular to both the X direction and the Y direction. The Z direction indicates the up-to-down direction of the battery module 10. The arrow pointing to the X direction, the arrow pointing to the Y direction, and the arrow pointing to the Z direction indicate the front, left, and up directions of the battery module 10, respectively. The relationship between the X direction, Y direction, and Z direction and the front-to-rear direction, left-to-right direction, and up-to-down direction of the battery module 10 is not limited to this example.

[0013] Hereinafter, as needed, the side indicated by the arrow indicating the X direction will be referred to as the +X side, and the side opposite the side indicated by the arrow indicating the X direction will be referred to as the -X side. Hereinafter, as needed, the side indicated by the arrow indicating the Y direction will be referred to as the +Y side, and the side opposite the side indicated by the arrow indicating the Y direction will be referred to as the -Y side. Hereinafter, as needed, the side indicated by the arrow indicating the Z direction will be referred to as the +Z side, and the side opposite the side indicated by the arrow indicating the Z direction will be referred to as the -Z side.

[0014] A battery module 10 according to an embodiment will be described with reference to Fig. 1. As shown in Fig. 1, the battery module 10 includes a plurality of battery cells 100, a plurality of compression pads 110, a first voltage detection device 200, a second voltage detection device 300, a first bus bar 410, a second bus bar 420, and a housing 500.

[0015] The multiple battery cells 100 are stacked in the Y direction with compression pads 110 disposed between adjacent battery cells 100. Hereinafter, as necessary, the multiple battery cells 100 and multiple compression pads 110 stacked alternately in the Y direction will be referred to as a stack of battery cells 100. The dimension of each battery cell 100 in the X direction is the dimension in the longitudinal direction of each battery cell 100. The dimension of each battery cell 100 in the Z direction is the dimension in the lateral direction of each battery cell 100. The dimension of each battery cell 100 in the Y direction is the dimension in the thickness direction of each battery cell 100. The shape of each battery cell 100 is not limited to this example.

[0016] Each battery cell 100 includes a battery element (not shown), an exterior material 102, a positive electrode tab 104, and a negative electrode tab 106. In one example, the battery element includes a plurality of positive electrodes and a plurality of negative electrodes (not shown) stacked alternately in the Y direction, and a separator (not shown) positioned between adjacent positive electrodes and negative electrodes in the Y direction. The exterior material 102 seals the battery element and an electrolyte (not shown). The positive electrode tab 104 is electrically connected to the positive electrode of the battery element. The positive electrode tab 104 is pulled out from one of both sides of the exterior material 102 in the X direction. The negative electrode tab 106 is electrically connected to the negative electrode of the battery element. The negative electrode tab 106 is pulled out from the other side of the exterior material 102 in the X direction. However, the structure of each battery cell 100 is not limited to this example.

[0017] Each battery cell 100 may be an all-solid-state battery. In an all-solid-state battery, a solid electrolyte layer is provided in a portion corresponding to a separator. An all-solid-state battery does not contain an electrolytic solution. Unless otherwise specified, the following description will be given assuming that each battery cell 100 is a battery cell containing an electrolytic solution.

[0018] The multiple battery cells 100 are electrically connected in a series-parallel combination. Specifically, cell groups including at least two battery cells 100 adjacent to each other in the Y direction and connected in parallel are stacked in the Y direction and connected in series. On the +X side of the stack of battery cells 100, a positive electrode tab 104 drawn from a battery cell 100 of one cell group connected in parallel and a negative electrode tab 106 drawn from a battery cell 100 of another cell group connected in parallel are electrically connected to each other, forming a tab group 108 including the positive electrode tab 104 and the negative electrode tab 106. The positive electrode tab 104 and the negative electrode tab 106 in the tab group 108 are joined to each other by, for example, laser welding. A tab group 108 is also located on the −X side of the stack of battery cells 100. Thus, multiple cell groups are connected in series from the cell group located at one end of the stack of battery cells 100 in the Y direction to the cell group located at the other end of the stack of battery cells 100 in the Y direction. Hereinafter, as necessary, the tab group 108 located on the +X side of the stack of battery cells 100 will be referred to as the +X side tab group 108, and the tab group 108 located on the −X side of the stack of battery cells 100 will be referred to as the −X side tab group 108.

[0019] The electrical connection of the plurality of battery cells 100 is not limited to the above example. For example, a stack of battery cells 100 may be formed by connecting single battery cells 100 in series.

[0020] The first voltage detection device 200 is configured to detect the voltages of the plurality of +X side tab groups 108. The first voltage detection device 200 has a first harness 210 and a first protector 220. The first harness 210 includes a plurality of first voltage detection terminals 212, a plurality of first voltage detection lines 214, and a first connector 216.

[0021] The first harness 210 serves as a voltage detection unit for detecting the voltages of the multiple +X-side tab groups 108. The multiple first voltage detection terminals 212 are arranged offset from one another in the Y direction. Each of the multiple first voltage detection terminals 212 is located on the +X side of each of the multiple +X-side tab groups 108. Each first voltage detection terminal 212 is made of a conductive material such as metal. The -X-side surface of each first voltage detection terminal 212 and the +X-side surface of each +X-side tab group 108 are joined to each other by a joining method such as laser welding. Thus, each first voltage detection terminal 212 and each +X-side tab group 108 are electrically connected to each other. One end of each first voltage detection wire 214 and each first voltage detection terminal 212 are electrically connected to each other. The other end of each first voltage detection wire 214 and each first connector 216 are electrically connected to each other.

[0022] The first protector 220 serves as a holder that at least partially holds the first harness 210. The first protector 220 covers the +X side portion of the stack of battery cells 100, with the multiple +X side tab groups 108 exposed through multiple first openings 220a provided in the first protector 220. The first protector 220 is an insulator such as resin. The multiple first voltage detection terminals 212 and the first protector 220 are at least partially attached to each other. Inside the housing 500, the multiple first voltage detection wires 214 are at least partially routed through the first protector 220. The first protector 220 at least partially holds the first harness 210, with the multiple first voltage detection terminals 212 and the first protector 220 at least partially attached to each other and the multiple first voltage detection wires 214 at least partially routed through the first voltage detection device 200. Therefore, by placing the first protector 220 at an appropriate position relative to the stack of battery cells 100, each of the multiple first voltage detection terminals 212 can be positioned at an appropriate position relative to each of the multiple +X side tab groups 108.

[0023] The voltage detection unit for detecting the voltage of the plurality of +X side tab groups 108 may have a structure different from that of the first harness 210 according to the embodiment, as long as it can detect the voltage of the plurality of +X side tab groups 108. The holder that at least partially holds the voltage detection unit may have a structure different from that of the first protector 220 according to the embodiment, as long as it can at least partially hold the voltage detection unit.

[0024] The second voltage detection device 300 is configured to detect the voltages of the multiple -X side tab groups 108. When viewed from the Z direction, the first voltage detection device 200 and the second voltage detection device 300 are substantially rotationally symmetric with respect to the center of the stack of battery cells 100.

[0025] Similar to the first voltage detection device 200, the second voltage detection device 300 includes a second harness 310 and a second protector 320. The second harness 310 and the second protector 320 can be substantially identical to the first harness 210 and the first protector 220, respectively, but do not need to be completely identical. Similar to the first harness 210, the second harness 310 includes a plurality of second voltage detection units 312, a plurality of second voltage detection lines 314, and a second connector 316. The plurality of second voltage detection units 312, the plurality of second voltage detection lines 314, and the second connector 316 can be substantially identical to the plurality of first voltage detection terminals 212, the plurality of first voltage detection lines 214, and the first connector 216, respectively, but do not need to be completely identical. The specifications such as the material and shape of each component of the first voltage detection device 200 and the specifications such as the material and shape of each component of the second voltage detection device 300 may differ from each other depending on the conditions of the first voltage detection device 200 and the conditions of the second voltage detection device 300.

[0026] The first bus bar 410 is disposed at the +Y side end of the first protector 220. The first bus bar 410 is electrically connected to the positive electrode tabs 104 that are drawn out to the +X side from the battery cells 100 of the cell group located at the +Y side end of the stack of battery cells 100. The first bus bar 410 functions as an external terminal for electrically connecting the battery module 10 to an external device such as another battery module.

[0027] The second bus bar 420 is disposed at the -Y side end of the second protector 320. The second bus bar 420 is electrically connected to the negative electrode tab 106 that is drawn out to the -X side from the battery cell 100 of the cell group located at the -Y side end of the stack of battery cells 100. The second bus bar 420 functions as an external terminal for electrically connecting the battery module 10 to an external device such as another battery module.

[0028] 1 , the positive electrode tab 104 at the end of a group of multiple cells connected in series is drawn out toward the +X side from the battery cell 100 of the cell group located at the end on the +Y side of the stack of battery cells 100, and the negative electrode tab 106 at the end of a group of multiple cells connected in series is drawn out toward the −X side from the battery cell 100 of the cell group located at the end on the −Y side of the stack of battery cells 100. Thus, the first bus bar 410 is disposed on the +X side and +Y side of the stack of battery cells 100, and the second bus bar 420 is disposed on the −X side and −Y side of the stack of battery cells 100. However, the arrangement of the positive electrode tab 104 and the negative electrode tab 106 at the end of a group of multiple cells connected in series may differ depending on the number of battery cells 100 included in the stack of battery cells 100. For example, there may be a case where the positive electrode tab 104 at the end of a group of multiple cells connected in series is pulled out toward the +X side from the battery cell 100 of the cell group located at the end on the +Y side of the stack of battery cells 100, and the negative electrode tab 106 at the end of a group of multiple cells connected in series is pulled out toward the +X side from the battery cell 100 of the cell group located at the end on the -Y side of the stack of battery cells 100. In this case, the first bus bar 410 is arranged on the +X side and the +Y side of the stack of battery cells 100, and the second bus bar 420 is arranged on the +X side and the -Y side of the stack of battery cells 100.

[0029] The housing 500 houses a stack of battery cells 100. The housing 500 has a first plate 510, a second plate 520, a third plate 530, a fourth plate 540, a fifth plate 550, and a sixth plate 560. Each plate is, for example, a metal plate.

[0030] The first plate 510 covers the +X side portion of the stack of battery cells 100 with the first voltage detection device 200 positioned between the stack of battery cells 100 and the first plate 510. The second plate 520 covers the -X side portion of the stack of battery cells 100 with the second voltage detection device 300 positioned between the stack of battery cells 100 and the second plate 520. The third plate 530 covers the +Y side portion of the stack of battery cells 100. The fourth plate 540 covers the -Y side portion of the stack of battery cells 100. The fifth plate 550 covers the +Z side portion of the stack of battery cells 100. The sixth plate 560 covers the -Z side portion of the stack of battery cells 100.

[0031] Fig. 2 is an exploded perspective view of the first voltage detection device 200 according to the embodiment, with the first harness 210 and the first bus bar 410 removed. Fig. 3 is an enlarged view of a portion of the first block 222 according to the embodiment. Fig. 4 is an enlarged view of a portion of the second block 224 according to the embodiment.

[0032] The first voltage detection device 200 according to the embodiment will be described with reference to Figures 2 to 4. The matters described for the first voltage detection device 200 with reference to Figures 2 to 4 are also applicable to the second voltage detection device 300.

[0033] As shown in FIG. 2 , the first protector 220 has a first block 222 and a second block 224. The first block 222 and the second block 224 are attachable to each other. The first block 222 is approximately half of the first protector 220 on the -Y side. The first block 222 includes a first middle region 222a that defines a plurality of first openings 220a located in approximately the half of the first protector 220 on the -Y side, a first upper region 222b located on the +Z side relative to the first middle region 222a, and a first lower region 222c located on the -Z side relative to the first middle region 222a. The second block 224 is approximately half of the first protector 220 on the +Y side. The second block 224 includes a second middle region 224a that defines a plurality of first openings 220a located in approximately half of the +Y side of the first protector 220, a second upper region 224b located on the +Z side of the second middle region 224a, and a second lower region 224c located on the -Z side of the second middle region 224a.

[0034] As shown in Figures 2 and 3, a middle protrusion 232 is provided at the +Y side end of the first middle region 222a. The middle protrusion 232 protrudes toward the second block 224. As shown in Figures 2 and 3, an upper protrusion 234 is provided at the +Y side end of the first upper region 222b. The upper protrusion 234 protrudes toward the second block 224. As shown in Figures 2 and 3, a lower protrusion 236 is provided at the +Y side end of the first lower region 222c. The lower protrusion 236 protrudes toward the second block 224.

[0035] As shown in Figures 2 and 4, a middle hole 242 is provided at the -Y side end of the second middle region 224a. The middle hole 242 opens toward the first block 222. As shown in Figures 2 and 4, an upper hole 244 is provided at the -Y side end of the second upper region 224b. The upper hole 244 opens toward the first block 222. As shown in Figures 2 and 4, a lower hole 246 is provided at the -Y side end of the second lower region 224c. The lower hole 246 opens toward the first block 222.

[0036] In this embodiment, when the first block 222 and the second block 224 are assembled together, the middle protrusion 232, the upper protrusion 234, and the lower protrusion 236 are inserted into the middle hole 242, the upper hole 244, and the lower hole 246, respectively. By inserting these protrusions into these holes, the first block 222 and the second block 224 can be aligned with each other. Therefore, the combination of the above-described protrusions and the above-described holes forms a structure for aligning the first block 222 and the second block 224 with each other. Furthermore, by inserting the above-described protrusions into the above-described holes, rattle of the first block 222 and the second block 224 in a direction perpendicular to the Y direction can be suppressed.

[0037] The structure for aligning the first block 222 and the second block 224 with each other is not limited to the structure described in the embodiment. For example, the number and arrangement of the combinations of protrusions and holes are not limited to the examples described in the embodiment. The first block 222 may have holes formed therein, and the second block 224 may have protrusions formed therein. The structure for aligning the first block 222 and the second block 224 with each other is not limited to the combination of protrusions and holes, and may be, for example, a combination of protrusions and grooves into which the protrusions fit.

[0038] As shown in FIGS. 2 and 3, an upper hook 252 is provided at the +Y side end of the first upper region 222b. The upper hook 252 protrudes toward the -Z side. As shown in FIGS. 2 and 3, a lower hook 254 is provided at the +Y side end of the first lower region 222c. The lower hook 254 protrudes toward the +Z side. As shown in FIG. 3, the +Z side surface of the lower hook 254 is inclined toward the -Z side toward the tip of the lower hook 254 on the +Z side. As shown in FIGS. 2 and 3, a reinforcing portion 256 is provided on the +X side of the lower hook 254. The reinforcing portion 256 can reinforce the strength of the lower hook 254 and the portion of the first block 222 surrounding the lower hook 254. The reinforcing portion 256 does not necessarily have to be provided.

[0039] 2 and 4, an upper rib 262 is provided at the -Y side end of the second upper region 224b. The upper rib 262 protrudes toward the +X side. 264 is provided at the -Y side end of the second lower region 224c. The lower groove 264 opens toward the -Z side.

[0040] In the embodiment, when the first block 222 and the second block 224 are assembled together, the upper hook 252 is located on the +Y side of the upper rib 262, and the lower hook 254 is located inside the lower groove 264. In the embodiment, the inclined surface on the +Z side of the lower hook 254 makes it difficult for the lower hook 254 to get caught when inserting the lower hook 254 into the lower groove 264, making it easier to insert the lower hook 254 into the lower groove 264. Even if the first block 222 and the second block 224 move in directions away from each other, the assembly of the first block 222 and the second block 224 is not released due to contact between the side surface on the -Y side of the upper hook 252 and the side surface on the +Y side of the upper rib 262 and the contact between the side surface on the -Y side of the lower hook 254 and the inner surface on the -Y side of the lower groove 264. Therefore, the combination of the upper hook 252 and the upper rib 262 and the combination of the lower hook 254 and the lower groove 264 are structured to restrict the movement of the first block 222 and the second block 224 in directions away from each other.

[0041] The structure for restricting the movement of the first block 222 and the second block 224 in the direction away from each other is not limited to the structure described above. For example, a structure corresponding to the upper rib 262 or the lower groove 264 may be provided on the first block 222, and a structure corresponding to the upper hook 252 or the lower hook 254 may be provided on the second block 224.

[0042] In the embodiment, when the first block 222 and the second block 224 are assembled together, the upper hook 252 and the lower hook 254 are movable toward the +Y side until any portion of the first block 222 and any portion of the second block 224 come into contact with each other. The first block 222 and the second block 224 are movable toward the +Y side, for example, until the +Y side end of the first upper region 222b and the −Y side end of the second upper region 224b come into contact with each other, or until the +Z side inclined surface of the lower hook 254 and the +Y side inner surface of the lower groove 264 come into contact with each other. Therefore, the combination of the above-described portions of the first block 222 and the second block 224 is structured to restrict movement of the first block 222 and the second block 224 in a direction toward each other.

[0043] The structure for restricting the movement of the first block 222 and the second block 224 toward each other is not limited to the structure described above. For example, the movement of the first block 222 and the second block 224 toward each other may be restricted by contact between one end on the +Y side of a protrusion such as the middle protrusion 232, the upper protrusion 234, or the lower protrusion 236 and the bottom end on the +Y side of a hole such as the middle hole 242, the upper hole 244, or the lower hole 246.

[0044] As described above, the first block 222 and the second block 224 according to the embodiment are movably fixed to each other while restricting the range of movement of the first block 222 and the second block 224 in the Y direction. Therefore, compared to when the first block 222 and the second block 224 are fixed immovably, the ability of the first voltage detection device 200 to conform to the shape of components arranged around the first voltage detection device 200, such as the battery cell 100 and the housing 500, can be improved. For example, an error may occur between the actual value of the Y direction spacing of the +X side tab group 108 and the design value of that spacing, or between the actual value of the Y direction spacing between the third plate 530 and the fourth plate 540 and the design value of that spacing. In the embodiment, the first block 222 and the second block 224 can be moved closer to or farther away from each other to adjust the Y direction dimension of the first protector 220 in accordance with the error. If the above-described actual value is less than the above-described design value, it is necessary to reduce the dimension of the first protector 220 in the Y direction. If the first block 222 and the second block 224 are fixed to each other and immovable, compressing the first protector 220 in the Y direction to reduce the dimension of the first protector 220 in the Y direction may result in damage to the first protector 220. However, in the embodiment, the dimension of the first protector 220 in the Y direction can be reduced by moving the first block 222 and the second block 224 closer to each other. Therefore, the possibility of damage to the first protector 220 can be reduced compared to when the first block 222 and the second block 224 are fixed to each other and immovable.

[0045] The fixing of the first block 222 and the second block 224 described in the embodiment can also be applied to other examples. For example, multiple portions of the first protector 220, such as three or more blocks aligned in the Y direction, may be fixed to be movable relative to each other. The multiple portions of the first protector 220 fixed to be movable relative to each other may be multiple portions aligned in a direction different from the Y direction, such as the Z direction.

[0046] Fig. 5 is an exploded perspective view of a portion of a first voltage detection device 200A according to Modification 1. Fig. 6 is a front view of a portion of a first protector 220A according to Modification 1 in a state in which a first block 222A and a second block 224A are assembled together. The first voltage detection device 200A according to Modification 1 is similar to the first voltage detection device 200 according to the embodiment, except for the following points. In Fig. 6, a white circle with a black dot indicating the X direction indicates that the tip of the arrow indicating the X direction is facing towards the front of the paper.

[0047] 5, the first block 222A according to the first modification has a first middle region 222aA, a first upper region 222bA, and a first lower region 222cA, similar to the first block 222 according to the embodiment. As shown in FIG. 5, the second block 224A according to the first modification has a second middle region 224aA, a second upper region 224bA, and a second lower region 224cA, similar to the second block 224 according to the embodiment.

[0048] As shown in Fig. 5, two upper protrusions 232A are provided at the -Y side end of second upper region 224bA. The two upper protrusions 232A are aligned in the Z direction and protrude toward first block 222A. As shown in Fig. 5, a lower protrusion 234A is provided at the -Y side end of second lower region 224cA. The lower protrusion 234A protrudes toward first block 222A.

[0049] As shown in Fig. 5, two upper holes 242A are provided at the end on the +Y side of the first upper region 222bA. The two upper holes 242A open toward the second block 224A. As shown in Fig. 5, a lower hole 244A is provided at the end on the +Y side of the first lower region 222cA. The lower hole 244A opens toward the first block 222A.

[0050] In Modification 1, when the first block 222A and the second block 224A are assembled together, the two upper protrusions 232A and the two lower protrusions 234A are inserted into the two upper holes 242A and the two lower holes 244A, respectively. By inserting these protrusions into these holes, the first block 222A and the second block 224A can be aligned with each other. Therefore, the combination of the above-described protrusions and holes forms a structure for aligning the first block 222A and the second block 224A with each other. Furthermore, by inserting the above-described protrusions into the above-described holes, rattle of the first block 222A and the second block 224A in a direction perpendicular to the Y direction can be suppressed.

[0051] As shown in Figures 5 and 6, two upper beams 252A are aligned in the Z direction and extend toward the +Y side from the +Y side end of the first upper region 222bA. The two upper beams 252A are configured to be flexible toward sides that move away from each other in the Z direction. As shown in Figures 5 and 6, two upper hooks 254A protrude from the +Y side tips of the two upper beams 252A toward sides that face each other in the Z direction. The opposing surfaces of the two upper hooks 254A in the Z direction are inclined toward sides that move away from each other in the Z direction as they approach the +Y side tips of the two upper hooks 254A.

[0052] As shown in FIGS. 5 and 6 , two first upper walls 256A and two second upper walls 258A are provided at the −Y side end of the second upper region 224bA. As shown in FIGS. 5 and 6 , the two first upper walls 256A are aligned in the Z direction. As shown in FIG. 6 , the two first upper walls 256A include two first upper end surfaces 256aA facing the +Y side and two upper side surfaces 256bA extending from both ends of the two first upper end surfaces 256aA in the Z direction toward the −Y side and facing outward from each other in the Z direction. As shown in FIG. 5 and 6 , the two second upper walls 258A are aligned in the Z direction. As shown in FIG. 6 , the two second upper walls 258A include two second upper end surfaces 258aA facing the −Y side. In a projection in the Z direction onto a plane perpendicular to the Z direction, the two second upper end faces 258aA are positioned so as to be shifted toward the +Y side relative to the two first upper end faces 256aA.

[0053] In Modification 1, two upper beams 252A are arranged along two upper side surfaces 256bA, and two upper hooks 254A fit into gaps between two first upper end surfaces 256aA and two second upper end surfaces 258aA, thereby attaching the first middle region 222aA and the second upper region 224bA to each other by snap-fitting. In the snap-fitting according to Modification 1, when the two upper beams 252A and the two upper hooks 254A are inserted in the Y direction into spaces on both sides of the two upper side surfaces 256bA in the Z direction, the two upper hooks 254A and the two upper side surfaces 256bA come into contact with each other. The contact between the two upper hooks 254A and the two upper side surfaces 256bA causes the two upper beams 252A to bend toward each other in the Z direction. The inclined surfaces on the opposing sides in the Z direction of the two first upper end faces 256aA make it easy for the two upper beams 252A and the two upper hooks 254A to be inserted in the Y direction into spaces that exist on both sides of the two upper side faces 256bA in the Z direction. When the two upper hooks 254A enter the gaps between the two first upper end faces 256aA and the two second upper end faces 258aA, the two upper beams 252A are restored to their original shape that is approximately parallel to the Y direction.

[0054] As shown in Figures 5 and 6, a lower beam 262A extends toward the +Y side from the +Y side end of first lower section 222cA. Lower beam 262A is configured to be flexible toward the -Z side. As shown in Figures 5 and 6, a lower hook 264A protrudes toward the +Z side from the +Y side tip of lower beam 262A. The +Z side surface of lower hook 264A is an inclined surface that slopes toward the -Z side as it approaches the +Y side tip of lower hook 264A.

[0055] As shown in Figures 5 and 6, a first lower wall 266A and a second lower wall 268A are provided at the -Y side end of the second lower region 224cA. As shown in Figure 6, the first lower wall 266A includes a first lower end face 266aA facing the +Y side and a lower side face 266bA that extends from the -Z side end of the first lower end face 266aA toward the -Y side and faces the -Z side. As shown in Figure 6, the second lower wall 268A includes a second lower end face 268aA facing the -Y side. When projected in the Z direction onto a plane perpendicular to the Z direction, the second lower end face 268aA is shifted toward the +Y side with respect to the first lower end face 266aA.

[0056] In Modification 1, the lower beam 262A is disposed along the lower side surface 266bA, and the lower hook 264A fits into the gap between the first lower end surface 266aA and the second lower end surface 268aA, thereby attaching the first lower region 222cA and the second lower region 224cA to each other by snap-fitting. In the snap-fitting according to Modification 1, when the lower beam 262A and the lower hook 264A are inserted in the Y direction into a space on the −Z side of the upper side surface 256bA, the lower hook 264A and the lower side surface 266bA come into contact with each other. The contact between the lower hook 264A and the lower side surface 266bA causes the lower beam 262A to bend toward the −Z side. The inclined surface on the +Z side of the lower hook 264A makes it easier for the lower beam 262A and the lower hook 264A to be inserted in the Y direction into a space on the −Z side of the lower side surface 266bA. When the lower hook 264A enters the gap between the first lower end surface 266aA and the second lower end surface 268aA, the lower beam 262A is restored to its original shape substantially parallel to the Y direction.

[0057] As shown in Figure 6, when projected in the Z direction onto a plane perpendicular to the Z direction, the Y-direction distance between both ends of each upper hook 254A in the Y direction is less than the Y-direction distance between the first upper end face 256aA and the second upper end face 258aA. In the example shown in Figure 6, a first clearance C1A exists between the -Y-side end of each upper hook 254A and the first upper end face 256aA, and a second clearance C2A exists between the +Y-side end of each upper hook 254A and the second upper end face 258aA. As shown in Figure 6, when projected in the Z direction onto a plane perpendicular to the Z direction, the Y-direction distance between both ends of the lower hook 264A in the Y direction is less than the Y-direction distance between the first lower end face 266aA and the second lower end face 268aA. In the example shown in Figure 6, a third clearance C3A exists between the -Y side end of the lower hook 264A and the first lower end face 266aA, and a fourth clearance C4A exists between the +Y side end of the lower hook 264A and the second lower end face 268aA.

[0058] In Modification 1, the first middle region 222aA and the second upper region 224bA are movable away from each other until at least one of the −Y-side end of each upper hook 254A comes into contact with the first upper end face 256aA and the −Y-side end of the lower hook 264A comes into contact with the first lower end face 266aA, and at least one of the first clearance C1A and the third clearance C3A disappears. Therefore, the combination of each upper hook 254A and each first upper wall 256A and the combination of the lower hook 264A and the first lower wall 266A are structured to restrict the movement of the first middle region 222aA and the second upper region 224bA away from each other.

[0059] In Modification 1, the first block 222A and the second block 224A are movable in a direction toward each other until the +Y side end of the first block 222A and the −Y side end of the second block 224A at least partially contact each other. Therefore, the combination of the +Y side end of the first block 222A and the −Y side end of the second block 224A is structured to restrict the movement of the first block 222A and the second block 224A in a direction toward each other.

[0060] Alternatively, the first middle region 222aA and the second upper region 224bA may be movable toward each other until at least one of the +Y side end of each upper hook 254A and the second upper wall 258A comes into contact with each other and the +Y side end of the lower hook 264A comes into contact with the second lower end face 268aA, and at least one of the second clearance C2A and the fourth clearance C4A disappears. Therefore, the combination of each upper hook 254A and each second upper wall 258A and the combination of the lower hook 264A and the second lower wall 268A may be configured to restrict the movement of the first middle region 222aA and the second upper region 224bA toward each other.

[0061] In the first modification, similar to the embodiment, the first block 222A and the second block 224A are movably fixed to each other while restricting the range of movement of the first block 222A and the second block 224A in the Y direction. Therefore, in the first modification, similar to the embodiment, it is possible to improve the ability of the first voltage detection device 200A to conform to the shape of the members arranged around the first voltage detection device 200A.

[0062] Fig. 7 is an exploded perspective view of a portion of a first voltage detection device 200B according to Modification 2. Fig. 8 is a front view of a portion of a first protector 220B according to Modification 2 in a state in which a first block 222B and a second block 224B are assembled together. The first voltage detection device 200B according to Modification 2 is similar to the first voltage detection device 200 according to the embodiment, except for the following points.

[0063] The first voltage detection device 200B according to the second modification includes a connector 230B. The connector 230B movably fixes a first block 222B and a second block 224B to each other. As shown in FIG. 7 , the connector 230B includes a base 232B, two first beams 234B, two first hooks 235B, two second beams 236B, and two second hooks 237B.

[0064] 7, the base 232B is hollow due to two through holes that penetrate the base 232B in the X direction and are aligned in the Z direction. The shape of the base 232B is not limited to the example shown in FIG.

[0065] 7, the two first beams 234B are aligned in the Z direction and extend from the −Y side edge of the base 232B toward the −Y side. The two first beams 234B are configured to be flexible toward each other in the Z direction.

[0066] 7, the two first hooks 235B protrude from the −Y side tips of the two first beams 234B toward sides that are separated from each other in the Z direction. The surfaces of the two first hooks 235B that face outward in the Z direction are inclined surfaces that are inclined toward each other as they approach the −Y side tips of the two first hooks 235B.

[0067] 7, the two second beams 236B are aligned in the Z direction and extend from the +Y side edge of the base 232B toward the +Y side. The two second beams 236B are configured to be flexible toward each other in the Z direction.

[0068] 7, the two second hooks 237B protrude from the +Y side tips of the two second beams 236B toward sides that are separated from each other in the Z direction. The surfaces of the two second hooks 237B that face outward in the Z direction are inclined surfaces that incline toward each other as they approach the +Y side tips of the two second hooks 237B.

[0069] As shown in Fig. 7, a first frame 242B is provided at the +Y side end of the first block 222B. The first frame 242B defines a first hole 243B extending in the Y direction. As shown in Fig. 7, a second frame 244B is provided at the -Y side end of the second block 224B. The second frame 244B defines a second hole 245B extending in the Y direction.

[0070] In Modification 2, the connector 230B and the first frame 242B are attached to each other by snap-fitting by inserting the two first beams 234B and the two first hooks 235B into the first holes 243B in the Y direction from the openings on the +Y side of the first holes 243B. In the snap-fitting according to Modification 2, when the two first beams 234B and the two first hooks 235B are inserted into the first holes 243B, the two first hooks 235B come into contact with both inner surfaces of the first frame 242B located on both sides of the first holes 243B in the Z direction. The contact between the two first hooks 235B and the inner surfaces of the first frame 242B causes the two first beams 234B to bend toward each other in the Z direction. The inclined surfaces of the two first hooks 235B positioned on the outside of each other in the Z direction make it easier for the two first beams 234B and the two first hooks 235B to be inserted into the first holes 243B in the Y direction. When the two first hooks 235B pass through the openings on the -Y side of the first holes 243B, the two first beams 234B are restored to their original shape that is approximately parallel to the Y direction.

[0071] In Modification 2, the connector 230B and the second frame 244B are attached to each other by snap-fitting by inserting the two second beams 236B and the two second hooks 237B into the second holes 245B in the Y direction from the openings on the -Y side of the second holes 245B. In the snap-fitting according to Modification 2, when the two second beams 236B and the two second hooks 237B are inserted into the second holes 245B, the two second hooks 237B come into contact with both inner surfaces of the second frame 244B located on both sides of the second holes 245B in the Z direction. The contact between the two second hooks 237B and the inner surfaces of the second holes 245B causes the two second beams 236B to bend toward each other in the Z direction. The inclined surfaces of the two second hooks 237B positioned on the outside of each other in the Z direction make it easier for the two second beams 236B and the two second hooks 237B to be inserted into the second holes 245B in the Y direction. When the two second hooks 237B pass through the openings on the +Y side of the second holes 245B, the two second beams 236B are restored to their original shape, which is approximately parallel to the Y direction.

[0072] In Modification 2, when the first block 222B and the second block 224B are assembled together, the two first beams 234B and the two second beams 236B are inserted through the first holes 243B and the second holes 245B, respectively. By inserting these beams through these holes, the first block 222B and the second block 224B can be aligned. Therefore, the combination of the beams and holes described above is a structure for aligning the first block 222B and the second block 224B with each other. Furthermore, by inserting the beams through the holes described above, rattle of the first block 222B and the second block 224B in a direction perpendicular to the Y direction can be suppressed.

[0073] In Modification 2, the first block 222B and the second block 224B are movable toward each other until the +Y side end of the first block 222B and the −Y side end of the second block 224B at least partially contact each other. In the example shown in FIG. 8 , a first clearance C1B exists between the +Y side end of the first block 222B and the −Y side end of the second block 224B. In the example shown in FIG. 8 , the first block 222B and the second block 224B are movable toward each other until the first clearance C1B no longer exists. Therefore, the combination of the +Y side end of the first block 222B and the −Y side end of the second block 224B is structured to restrict the movement of the first block 222B and the second block 224B toward each other.

[0074] In Modification 2, the first block 222B and the second block 224B are movable away from each other until at least one of the following occurs: contact between the +Y side ends of the two first hooks 235B and the −Y side ends of portions of the first frame 242B located on both sides in the Z direction with respect to the first hole 243B; or contact between the −Y side ends of the two second hooks 237B and the +Y side ends of portions of the second frame 244B located on both sides in the Z direction with respect to the second hole 245B. In the example shown in FIG. 8 , the +Y side ends of the two first hooks 235B and the −Y side ends of portions of the first frame 242B located on both sides in the Z direction with respect to the first hole 243B come into contact with each other, and a second clearance C2B exists between the −Y side ends of the two second hooks 237B and the +Y side ends of portions of the second frame 244B located on both sides in the Z direction with respect to the second hole 245B. 8, the second block 224B is movable in a direction away from the first block 222B until the second clearance C2B disappears. Therefore, the combination of the hook and the frame described above is a structure that restricts the movement of the first block 222B and the second block 224B in a direction away from each other.

[0075] In the second modification, similar to the embodiment, the first block 222B and the second block 224B are movably fixed to each other while restricting the range of movement of the first block 222B and the second block 224B in the Y direction. Therefore, in the second modification, similar to the embodiment, it is possible to improve the ability of the first voltage detection device 200B to conform to the shape of the members arranged around the first voltage detection device 200B.

[0076] Although the embodiments and modifications of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various configurations other than those described above can also be adopted.

[0077] This application claims priority based on Japanese Patent Application No. 2024-104780, filed June 28, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0078] REFERENCE SIGNS LIST 10 Battery module, 100 Battery cell, 102 Exterior material, 104 Positive electrode tab, 106 Negative electrode tab, 108 Tab group, 110 Compression pad, 200, 200A, 200B First voltage detection device, 210 First harness, 212 First voltage detection terminal, 214 First voltage detection line, 216 First connector, 220, 220A, 220B First protector, 220a First opening, 222, 222A, 222B First block, 222a, 222aA First middle region, 222b, 222bA First upper region, 222c, 222cA First lower region, 224, 224A, 224B Second block, 224a, 224aA Second middle region, 224b, 224bA Second upper region, 224c, 224cA Second lower region, 230B Connector, 232 Middle protrusion, 232A Upper protrusion, 232B Base, 234 Upper protrusion, 234A Lower protrusion, 234B First beam, 235B First hook, 236 Lower protrusion, 236B Second beam, 237B Second hook, 242 Middle hole, 242A Upper hole, 242B First frame, 243B First hole, 244 Upper hole, 244A Lower hole, 244B Second frame, 245B Second hole, 246 Lower hole, 252 Upper hook, 252A Upper beam, 254 Lower hook, 254A Upper hook, 256 Reinforcement portion, 256A First upper wall, 256aA First upper end surface, 256bA Upper side surface, 258A Second upper wall, 258aA Second upper end surface, 262 Upper rib, 262A Lower beam, 264 Lower groove, 264A Lower hook, 266A First lower wall, 266aA First lower end surface, 266bA Lower side surface, 268A Second lower wall, 268aA Second lower end surface, 300 Second voltage detection device, 310 Second harness, 312 Second voltage detection unit, 314 Second voltage detection line, 316 Second connector, 320 Second protector, 410 First bus bar, 420 Second bus bar, 500 Housing, 510 First plate, 520 Second plate, 530 Third plate, 540 Fourth plate, 550 Fifth plate, 560 Sixth plate, C1A, C1B First clearance, C2A, C2B Second clearance, C3A 3rd Clearance, C4A 4th Clearance

Claims

1. A voltage detection device comprising: a voltage detection unit for detecting the voltage of a battery cell; and a holder that at least partially holds the voltage detection unit, the holder having a plurality of parts that are fixed so as to be movable relative to each other.

2. The voltage detection device according to claim 1, wherein the holder has a structure for restricting movement of the plurality of portions.

3. A voltage detection device according to claim 1 or 2, wherein the holder has a structure for aligning the plurality of portions with each other.

4. A voltage detection device according to any one of claims 1 to 3, wherein the voltage detection sections are arranged with at least a partial offset in a predetermined direction, and the plurality of sections are aligned in the predetermined direction.

5. A battery module comprising: the battery cell; and the voltage detection device according to any one of claims 1 to 4.

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