Battery pack

Abstract

To provide a battery pack that can protect a battery from a load input due to a vehicle collision while being light-weighted.SOLUTION: A battery pack 1 includes a battery 10 and a battery case 20, and is mounted on a vehicle V. The battery case 20 includes: a base plate 30 on which the battery 10 is placed; a frame member 40 joined to an outer edge of the base plate 30; and a cover 50 that covers the battery 10 and is attached to the frame member 40 via a seal member 60. The frame member 40 has a protection region R1 located inside the seal member 60 and a deformation region R2 located outside the seal member 60. The base plate 30 is joined to the frame member 40 in the protection region R1, and a tip portion viewed in a cross-section extends to at least the deformation region R2.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a battery pack mounted on a vehicle.

Background Art

[0002] In recent years, research and development have been conducted on secondary batteries (hereinafter also referred to as batteries) that contribute to energy efficiency in order to enable more people to access affordable, reliable, sustainable, and advanced energy.

[0003] Large-capacity batteries are mounted on vehicles such as battery electric vehicles, hybrid vehicles, and fuel cell vehicles. Since the batteries mounted on such vehicles are high-voltage components, it is necessary to protect the batteries from impact. However, a large load may be input to the batteries due to a collision of the vehicle or the like.

[0004] On the other hand, in the battery pack described in Patent Document 1, the bottom wall of the tray on which the battery is mounted has a tray deformation region. When a side collision load due to a side collision occurs, the collision energy is absorbed by the deformation of the tray deformation region.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the structure described in Patent Document 1, although the collision energy can be absorbed by the tray deformation region formed on the bottom wall of the tray, it is necessary to form the side beam thick in order to suppress the deformation of the side beam and protect the battery module, and the weight of the battery case has increased accordingly.

[0007] The present invention provides a battery pack that can protect a battery against load input due to a vehicle collision while achieving weight reduction.

Means for Solving the Problems

[0008] The present invention is a battery pack mounted on a vehicle, comprising a battery and a battery case that houses the battery, wherein the battery case includes a base plate on which the battery is placed, a frame member joined to an outer edge portion of the base plate, and a cover that covers the battery and is attached to the frame member via a sealing member, wherein the frame member has a protection region located inside the sealing member and a deformation region located outside the sealing member, 、 In the protection area or the deformation area, a rigid member is provided separately from the frame member and has a higher rigidity than the rigidity of the frame member. The tip of the base plate extends to the outside of the rigid member. and Moreover, the present invention is a battery, a battery case for housing the battery, and a battery pack mounted on a vehicle, wherein the battery case includes a base plate on which the battery is placed, a frame member joined to the outer edge of the base plate, and a cover that covers the battery and is attached to the frame member via a seal member. The frame member has a protection area located inside the seal member, and a deformation area located outside the seal member. The base plate is joined to the frame member in the protection area, and the tip portion in cross section extends at least to the deformation area. The tip of the base plate is located outside the frame member. Moreover, the present invention is a battery, a battery case for housing the battery, and a battery pack mounted on a vehicle, wherein the battery case includes a base plate on which the battery is placed, a frame member joined to the outer edge of the base plate, and a cover that covers the battery and is attached to the frame member via a seal member. The frame member has a protection area located inside the seal member, and a deformation area located outside the seal member. The base plate is joined to the frame member in the protection area, and the tip portion in cross section extends at least to the deformation area. The tip of the base plate is located inside the outer edge of the frame member. The frame member has a portion located below the base plate in the deformation area.

Effect of the Invention

[0009] According to the present invention, while achieving weight reduction, the battery can be protected against load input caused by a vehicle collision.

Brief Description of the Drawings

[0010]

Figure 1

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Mode for Carrying Out the Invention

[0011] Hereinafter, a battery pack according to an embodiment of the present invention will be described with reference to the accompanying drawings. It should be noted that the drawings are to be viewed in the direction of the reference numerals, and in the following description, the front-rear, left-right, and up-down directions are described according to the directions seen from the driver of the vehicle. In the drawings, the front of the vehicle is indicated as Fr, the rear as Rr, the left as L, the right as R, the upper as U, and the lower as D. Also, the left-right direction is also referred to as the vehicle width direction.

[0012] As shown in FIG. 1, a battery pack 1 according to an embodiment of the present invention is mounted on a vehicle V. The vehicle V is an electric vehicle such as a battery electric vehicle, a hybrid vehicle, or a fuel cell vehicle, for example. The battery pack 1 is disposed below the floor panel of the vehicle V and attached to the vehicle body.

[0013] As shown in FIGS. 2 and 3, the battery pack 1 includes four battery modules 11 and a battery case 20 that houses the battery modules 11.

[0014] The four battery modules 11 are arranged in two rows in the front-rear direction and two rows in the left-right direction. The four battery modules 11 are electrically connected to each other via electrical connection members (such as bus bars) not shown. The battery module 11 stores electric power to be supplied to a motor or the like that serves as a drive source of the vehicle V. Note that the number of battery modules 11 can be arbitrarily set, and the arrangement is not particularly limited.

[0015] As shown in FIGS. 3 and 4, each battery module 11 has a plurality of battery cells 12 laminated in the vehicle width direction. In FIG. 3, the plurality of battery cells 12 are shown by broken lines. Each battery cell 12 is, for example, a laminate type cell. The laminate type cell has a positive electrode to which a positive electrode tab is connected, a negative electrode to which a negative electrode tab is connected, an electrolyte disposed between the positive electrode and the negative electrode, and a laminate film that houses these, and performs charge and discharge by the transfer of ions (for example, lithium ions) between the positive electrode and the negative electrode via the electrolyte. Note that each battery cell 12 is not limited to the laminate type, and may be a square type or a cylindrical type, and the electrolyte may be liquid or solid. In the following description, the four battery modules 11 may also be collectively referred to as the battery 10.

[0016] Returning to FIG. 2, the battery case 20 includes a base plate 30 on which the battery 10 is placed, a frame member 40 that constitutes the outer frame of the battery case 20, and a cover 50 that covers the battery 10.

[0017] The base plate 30 is formed by pressing a metal material such as aluminum. The base plate 30 has a bottom plate 31 on which the battery 10 is placed and a water jacket plate 32 provided below the bottom plate 31, and is composed of two plates overlapping in the vertical direction. A water jacket 33 through which a refrigerant (e.g., cooling water) for cooling the battery 10 flows is formed between the bottom plate 31 and the water jacket plate 32 (see FIG. 5). Note that the base plate 30 may be composed of only one (i.e., only the bottom plate 31) or three or more.

[0018] Also, a heat insulating material 34 made of, for example, foamed polypropylene is attached to the base plate 30 from below to cover the water jacket 33 from below. Further, a lower cover 35 is attached to the base plate 30 from below the heat insulating material 34.

[0019] The frame member 40 is joined to the outer edge of the base plate 30 and constitutes the outer frame (i.e., the rear wall, the front wall, the left wall, and the right wall) of the battery case 20. In recent years, the demand for sustainable materials for casting materials has been increasing, and in this embodiment, a casting material (e.g., an aluminum casting material) is applied to the frame member 40. The frame member 40 has a rear cross member 41 provided at the rear edge of the base plate 30, a front cross member 42 provided at the front edge of the base plate 30, and a pair of side frames 43, 44 provided at the left and right edges of the base plate 30. The rear cross member 41 and the front cross member 42 extend in the left-right direction, and the pair of side frames 43, 44 extend in the front-rear direction. Also, the rear cross member 41 and the front cross member 42 are connected to the pair of side frames 43, 44 by welding or the like.

[0020] The rear cross member 41 and the front cross member 42 are provided with fixing portions 47 for fixing the battery 10 to the base plate 30 and the frame member 40. Further, the rear cross member 41, the front cross member 42, and the pair of side frames 43, 44 are provided with fastening portions fastened to the vehicle body by bolts or the like.

[0021] Further, the frame member 40 is provided at the central portion of the base plate 30 in the front-rear direction and further has a central cross member 45 extending in the left-right direction. The central cross member 45 is disposed between the two battery modules 11 disposed on the front side and the two battery modules 11 disposed on the rear side. Similar to the rear cross member 41 and the front cross member 42, the central cross member 45 is provided with a fixing portion 47 to which the battery 10 is fixed. Further, the central cross member 45 is connected to the pair of side frames 43, 44 by welding or the like.

[0022] The cover 50 is attached to the frame member 40 via a seal member 60. Although the cover 50 is not shown in FIG. 3, the seal member 60 is provided between the upper surface 40a of the frame member 40 and the outer edge portion 51 of the cover 50. By attaching the cover 50 to the upper surface 40a of the frame member 40 with the seal member 60 interposed therebetween, the inside of the battery case 20 is sealed. The attachment of the cover 50 to the frame member 40 is performed by, for example, bolts or the like. Here, in the state where the cover 50 is attached, the side of the battery 10 with respect to the seal member 60 is the inside of the battery case 20, and the side opposite to the battery 10 with respect to the seal member 60 is the outside of the battery case 20.

[0023] When a large load is input from the outside of the battery case 20 to the battery pack 1 configured as described above, in order to reduce the deformation of the battery case 20, generally, the load-bearing capacity of the frame member 40 constituting the outer frame of the battery case 20 is increased. When the above-described casting material is applied to the frame member 40 to provide a load-bearing capacity, it is necessary to significantly increase the thickness of the frame member 40, which increases the component weight of the battery pack 1. Therefore, in the present embodiment, not only the frame member 40 of the casting material but also the base plate 30 is utilized to efficiently provide a load-bearing capacity without increasing the thickness of the frame member 40.

[0024] Hereinafter, the configurations of the rear cross member 41 and the front cross member 42 and the configuration of the base plate 30 that can efficiently provide a load-bearing capacity when a large load is input to the battery pack 1 will be described in detail. First, the rear cross member 41 and the rear end portion 301 of the base plate 30 will be described with reference to FIGS. 5 and 6.

[0025] The rear cross member 41 includes a joint portion 410, an inner wall portion 411, an upper wall portion 412, and an outer wall portion 413. The joint portion 410 is a portion joined to the upper surface of the base plate 30. The rear cross member 41 and the base plate 30 are joined by, for example, friction stir welding or welding. The inner wall portion 411 stands upright upward from the joint portion 410 and is located inside the battery case 20. The upper wall portion 412 extends in the outer direction of the battery case 20 from the upper end of the inner wall portion 411. The upper wall portion 412 constitutes the upper surface 40a of the frame member 40 and abuts against the seal member 60 (shown by a two-dot chain line in FIG. 5) when the cover 50 is attached. The outer wall portion 413 is provided outside the battery case 20 and extends downward from the upper wall portion 412. The inner wall portion 411, the upper wall portion 412, and the outer wall portion 413 form a shape in which a cross section cut by a plane orthogonal to the longitudinal direction (left-right direction) of the rear cross member 41 opens downward.

[0026] The rear cross member 41 has a protection region R1 located inside the seal member 60, that is, inside the battery case 20, and a deformation region R2 located outside the seal member 60, that is, outside the battery case 20.

[0027] The protection region R1 is a region that should be protected without deformation from the perspective of protecting the battery 10 when a large load is input to the battery pack 1 due to a collision of the vehicle V or the like. The protection region R1 is constituted by the inside portions of the joint portion 410, the inner wall portion 411, and the upper wall portion 412 that are more inside than the seal member 60.

[0028] The deformation region R2 is a region where deformation is allowed when a large load is input to the battery pack 1. When the deformation region R2 is deformed by an external load input, the collision energy is absorbed in the deformation region R2. The deformation region R2 is constituted by the outside portion of the upper wall portion 412 that is more outside than the seal member 60 and the outer wall portion 413.

[0029] In the present embodiment, the base plate 30 is joined to the rear cross member 41 in the protection region R1, and the rear end portion 301 in terms of cross section extends to the deformation region R2. According to such a configuration, when the vehicle V collides, the rear end portion 301 of the base plate 30 receives the load before the load due to the collision is applied to the protection region R1 of the rear cross member 41 from the rear of the vehicle. Thereby, the deformation of the protection region R1 of the rear cross member 41, that is, the deformation inside the battery case 20 can be suppressed. Further, the portion of the base plate 30 located in the deformation region R2 absorbs the collision energy by the deformation when deforming due to the input load. That is, the crush stroke S1 of the base plate 30 is ensured. Furthermore, since the deformation of the protection region R1 of the rear cross member 41 is suppressed by using the base plate 30, it is not necessary to form the rear cross member 41 thick. Therefore, while achieving weight reduction, the battery 10 can be protected against the load input due to the collision of the vehicle V.

[0030] Also, as described above, the base plate 30 is composed of two plates overlapping in the vertical direction, namely a bottom plate 31 and a water jacket plate 32. With such a configuration, the yield strength of the base plate 30 increases, and the deformation of the protection region R1 of the rear cross member 41 can be more effectively suppressed.

[0031] Further, the rear end portion 301 of the base plate 30 is located inside the outer edge (here, the outer wall portion 413) of the rear cross member 41. This shortens the base plate 30, and the weight of the battery pack 1 can be reduced.

[0032] Also, the rear cross member 41 has a lower end portion 414 located below the base plate 30 in the deformation region R2. The lower end portion 414 is the lower end portion of the outer wall portion 413. In other words, when viewed from the rear, the outer wall portion 413 of the rear cross member 41 is provided so as to overlap the rear end portion 301 of the base plate 30. With such a configuration, for example, when the vehicle V contacts a curb or the like and receives a load from below, the deformation region R2 of the rear cross member 41 receives the load before the base plate 30, so that the base plate 30 can be protected, and thus the battery 10 can be protected. In the present embodiment, the rear end portion 301 of the base plate 30 and the outer wall portion 413 are separated from each other, but they may be in contact with each other.

[0033] Next, with reference to FIG. 7, the front cross member 42 and the front end portion 302 of the base plate 30 will be described.

[0034] The front cross member 42 includes a joint portion 420, an inner wall portion 421, an upper wall portion 422, and an outer wall portion 423, similar to the rear cross member 41. Similarly to the rear cross member 41, the inner portion of the joint portion 420, the inner wall portion 421, and the upper wall portion 422, which is inside the seal member 60, constitutes the protection region R1 of the front cross member 42, and the outer portion of the upper wall portion 422 and the outer wall portion 423, which is outside the seal member 60, constitute the deformation region R2 of the front cross member 42.

[0035] The base plate 30 is joined to the front cross member 42 in the protection region R1, and the front end portion 302 in cross section extends to the deformation region R2. Therefore, when the vehicle V collides, before the load due to the collision is applied to the protection region R1 from the front of the vehicle, the front end portion 302 of the base plate 30 receives the load. Thereby, deformation of the protection region R1 of the front cross member 42, that is, deformation inside the battery case 20 can be suppressed, and the battery 10 can be protected.

[0036] Incidentally, inside the space surrounded by the base plate 30 and the front cross member 42, a welding nut 36 used for fastening the bottom plate 31 and the water jacket plate 32 is provided. In the present embodiment, the welding nut 36 is provided in the deformation region R2. The welding nut 36 has a higher rigidity than the rigidity of the front cross member 42 and is an example of the rigid member of the present invention. The welding nut 36 is difficult to deform even when a large load is applied, and the region where the welding nut 36 is provided becomes a region that does not collapse, that is, a dead stroke region S2.

[0037] In the vicinity of the welding nut 36, the outer wall portion 423 of the front cross member 42 has an inclined portion 423a that extends downward and inclines from the upper wall portion 422 to the upper surface of the base plate 30, a horizontal portion 423b that extends horizontally along the upper surface of the base plate 30, and a vertical wall portion 423c that extends downward from the tip of the horizontal portion 423b. The welding nut 36 is disposed in a space surrounded by the upper wall portion 422, the inclined portion 423a, and the base plate 30.

[0038] Here, the front end portion 302 of the base plate 30 extends to the outside of the welding nut 36. According to such a configuration, the portion of the base plate 30 located outside the welding nut 36 absorbs the collision energy by deformation when deforming due to the input load. That is, even when the rigid member, the welding nut 36, is provided, the crush stroke S1 of the base plate 30 can be ensured outside the protection region R1.

[0039] Also, in the vicinity of the welding nut 36, similar to other parts, the front end portion 302 of the base plate 30 is located inside the outer edge of the front cross member 42 (here, the vertical wall portion 423c). As a result, the base plate 30 is shortened, and the weight of the battery pack 1 can be reduced.

[0040] Furthermore, the front cross member 42 has a lower end portion 424 that is located below the base plate 30 in the deformation region R2. The lower end portion 424 is the lower end portion of the vertical wall portion 423c of the outer wall portion 423. In other words, when viewed from the rear, the front cross member 42 is provided so as to overlap with the front end portion 302 of the base plate 30. According to such a configuration, for example, when the vehicle V contacts a curb or the like and receives a load from below, the deformation region R2 of the front cross member 42 receives the load before the base plate 30, so that the base plate 30 can be protected, and thus the battery 10 can be protected.

[0041] 《Modification Examples of Frame Member and Base Plate》 Figs. 8 to 11 are diagrams showing modification examples 1 to 4 of the rear end portion 301 of the rear cross member 41 and the base plate 30, respectively. Note that members common to the above-described embodiments will be described using common reference numerals.

[0042] As shown in Fig. 8, in modification example 1, unlike the above-described embodiment, the lower end portion of the outer wall portion 413 is located above the base plate 30, and the rear end portion 301 of the base plate 30 extends beyond the deformation region R2 of the rear cross member 41.

[0043] As shown in Fig. 9, in modification example 2, the rear cross member 41 has a hat-shaped cross section. The rear cross member 41 of modification example 2 extends in the outer direction of the battery case 20 from the lower end portion of the outer wall portion 413, and further has a joint portion 417 joined to the upper surface of the base plate 30. Also, the rear end portion 301 of the base plate 30 extends beyond the deformation region R2 of the rear cross member 41.

[0044] As shown in FIG. 10, in Modification 3, the rear cross member 41 does not have an outer wall portion 413. Further, the rear end portion 301 of the base plate 30 extends beyond the deformation region R2 of the rear cross member 41.

[0045] As shown in FIG. 11, in Modification 4, the rear cross member 41 has a substantially U-shaped configuration that opens to the outside of the battery case 20. The rear cross member 41 of Modification 4 does not have an outer wall portion 413. Further, the rear end portion 301 of the base plate 30 extends beyond the deformation region R2 of the rear cross member 41.

[0046] In Modifications 1 to 4, the rear end portion 301 of the base plate 30 extends beyond the deformation region R2 of the rear cross member 41, that is, the rear end portion 301 of the base plate 30 is located outside the rear cross member 41. With such a configuration, when a collision of the vehicle V occurs, the base plate 30 receives a load before the rear cross member 41. Therefore, deformation of the rear cross member 41 can be further suppressed, and it becomes easier to protect the battery 10.

[0047] FIGS. 12 to 15 are diagrams showing Modifications 5 to 8 of the rear cross member 41 and the base plate 30, respectively. The rear cross members 41 of Modifications 5 to 8 have the same configuration as Modifications 1 to 4 described above, but the configuration of the base plate 30 is different.

[0048] In Modifications 5 to 8, the rear end portion 301 of the base plate 30 is located inside the outer edge of the rear cross member 41. With such a configuration, weight reduction of the base plate 30 and the rear cross member 41 can be achieved, and as a result, weight reduction of the battery pack 1 can be achieved.

[0049] The above-described Modifications 1 to 8 relate to the rear end portion 301 of the rear cross member 41 and the base plate 30, but Modifications 1 to 8 can also be applied to the front cross member 42 and the front end portion 302 of the base plate 30.

[0050] As described above, an embodiment of the present invention and its modifications have been described with reference to the accompanying drawings. Needless to say, the present invention is not limited to such an embodiment. It is obvious that those skilled in the art can conceive various modifications or corrections within the scope described in the claims, and it is naturally understood that they also belong to the technical scope of the present invention. Further, within the scope not departing from the gist of the invention, the constituent elements in the above embodiment may be arbitrarily combined.

[0051] In the above-described embodiment, a casting material is applied to the frame member 40, but the present invention is not limited thereto, and the material and manufacturing method applied to the frame member 40 are arbitrary.

[0052] Also, in the above-described embodiment, the welding nut 36 is provided in the deformation region R2, but it may be provided in the protection region R1.

[0053] At least the following matters are described in this specification. In the parentheses, the corresponding constituent elements and the like in the above-described embodiment are shown as an example, but the present invention is not limited thereto.

[0054] (1) A battery (battery 10), A battery case (battery case 20) that houses the battery, and a battery pack (battery pack 1) mounted on a vehicle (vehicle V), The battery case includes A base plate (base plate 30) on which the battery is placed, A frame member (rear cross member 41, front cross member 42) joined to the outer edge portion of the base plate, A cover (cover 50) that covers the battery and is attached to the frame member via a seal member (seal member 60), The frame member includes A protection region (protection region R1) located inside the seal member, A deformation region (deformation region R2) located outside the seal member, The base plate is joined to the frame member in the protection region, and the tip portion (rear end portion 301, front end portion 302) in terms of cross-section extends at least to the deformation region. Battery pack.

[0055] (1) According to this, since the tip portion of the base plate extends at least to the deformation region of the frame member, when a vehicle collision or the like occurs, before the load due to the collision is applied to the protection region, the tip portion of the base plate receives the load due to the collision. Therefore, deformation of the protection region of the frame member, that is, deformation inside the battery case can be suppressed. Also, since deformation of the protection region of the frame member can be suppressed using the base plate, it is not necessary to form the frame member thick. Therefore, while achieving weight reduction, the battery can be protected against load input due to a vehicle collision or the like.

[0056] (2) The battery pack according to (1), The base plate is composed of a plurality of plates (bottom plate 31 and water jacket plate 32) that overlap in the vertical direction. Battery pack.

[0057] (2) According to this, since the yield strength of the base plate increases, deformation of the protection region of the frame member can be more suppressed.

[0058] (3) The battery pack according to (1) or (2), In the protection region or the deformation region, a rigid member (welding nut 36) having a higher rigidity than that of the frame member is provided, The tip portion of the base plate extends to the outside of the rigid member. Battery pack.

[0059] According to (3), even when the rigid member is arranged, since the tip of the base plate extends outside the rigid member, the crush stroke of the base plate can be ensured. That is, for a relatively small load, the base plate supports the load, and for a relatively large load, the base plate extending outside the rigid member can absorb the load while deforming, preventing the movement of the rigid member that is difficult to absorb the load and protecting the battery.

[0060] (4) A battery pack according to any one of (1) to (3), wherein the tip of the base plate is located outside the frame member, Battery pack.

[0061] (4) According to (4), when a collision of a vehicle occurs, the load input is applied to the base plate prior to the frame member, making it easier to protect the battery.

[0062] (5) A battery pack according to any one of (1) to (3), wherein the tip of the base plate is located inside the outer edge of the frame member, Battery pack.

[0063] (5) According to (5), since the base plate can be shortened, the weight of the battery pack can be reduced.

[0064] (6) A battery pack according to (5), wherein the frame member has portions (lower end portions 414, 424) located below the base plate in the deformation region, Battery pack.

[0065] (6) According to (6), for example, when the vehicle contacts a curb or the like and receives a load from below, the deformation region of the frame member receives the load prior to the base plate, so that the base plate can be protected, and thus the battery can be protected.

Description of Reference Numerals

[0066] 1 battery pack 10 batteries 20 battery cases 30 base plates 301 rear end (tip) 302 front end (tip) 31 bottom plate (plate) 32 water jacket plate (plate) 36 welding nut (rigid member) 41 rear cross member (frame member) 414 lower end 42 front cross member (frame member) 424 lower end 50 cover 60 seal member R1 protection area R2 deformation area V vehicle

Claims

1. A battery pack mounted on a vehicle, comprising: a battery; and a battery case for housing the battery, wherein the battery case includes: a base plate on which the battery is placed; a frame member joined to an outer edge portion of the base plate; and a cover that covers the battery and is attached to the frame member via a sealing member, wherein the frame member has: a protection region located inside the sealing member; and a deformation region located outside the sealing member, wherein the base plate is joined to the frame member in the protection region, and a tip portion in a cross section extends at least to the deformation region, wherein a rigid member, which is provided separately from the frame member and has a higher rigidity than the frame member, is disposed in the protection region or the deformation region, and the tip portion of the base plate extends outside the rigid member.

2. The battery pack according to claim 1, wherein the base plate is composed of a plurality of plates overlapping in a vertical direction.

3. A battery pack mounted on a vehicle, comprising: a battery; and a battery case for housing the battery, wherein the battery case includes: a base plate on which the battery is placed; a frame member joined to an outer edge portion of the base plate; and a cover that covers the battery and is attached to the frame member via a sealing member, wherein the frame member has: a protection region located inside the sealing member; and a deformation region located outside the sealing member, wherein the base plate is joined to the frame member in the protection region, and a tip portion in a cross section extends at least to the deformation region, and the tip portion of the base plate is located outside the frame member.

4. A battery pack mounted on a vehicle, comprising: a battery; and a battery case for housing the battery, wherein the battery case includes: a base plate on which the battery is placed; a frame member joined to an outer edge portion of the base plate; and a cover that covers the battery and is attached to the frame member via a sealing member, wherein the frame member has: a protection region located inside the sealing member; It has a deformation region located outside the seal member. The base plate is joined to the frame member in the protection region, and the tip end portion in a cross-section extends at least up to the deformation region. The tip end portion of the base plate is located inside the outer edge of the frame member. The frame member has a portion located below the base plate in the deformation region. Battery pack.

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