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EP-4738566-A1 - POWER STORAGE DEVICE

EP4738566A1EP 4738566 A1EP4738566 A1EP 4738566A1EP-4738566-A1

Abstract

A power storage device includes: a lower case including a bottom wall portion (23); a first power storage module (11A) and a second power storage module (11B) disposed on a side close to an inner surface of the bottom wall portion (23) and spaced apart from each other in a front-rear direction; and a cover member (50) to cover the bottom wall portion (23) from below. The bottom wall portion (23) includes a first protrusion (26) protruding downward, the first power storage module (11A) has a rear-side corner portion (11b), the second power storage module (11B) has a front-side corner portion (11a), the first protrusion (26) has a front-side base portion (26a) and a rear-side base portion (26b), the front-side base portion (26a) is located at a position overlapping with the rear-side corner portion (11b) in an upward-downward direction, and the rear-side base portion (26b) is located at a position overlapping with the front-side corner portion (11a) in the upward-downward direction.

Inventors

  • NISHIKI, NOBUYASU

Assignees

  • TOYOTA JIDOSHA KABUSHIKI KAISHA

Dates

Publication Date
20260506
Application Date
20250818

Claims (4)

  1. A power storage device (1) comprising: a lower case (22) including a bottom wall portion (23) having an inner surface (23a) and an outer surface (23b) that are arranged in an upward-downward direction; a first power storage module (11A) and a second power storage module (11B) that are fixed to the inner surface (23a) and spaced apart from each other in a front-rear direction orthogonal to the upward-downward direction; and a cover member (50) to cover the bottom wall portion (23) from below in a state in which a gap is formed between the cover member (50) and the bottom wall portion (23), wherein the bottom wall portion (23) includes a first protrusion (26) protruding downward, the first protrusion (26) is located between the first power storage module (11A) and the second power storage module (11B) when viewed from above, the first power storage module (11A) has a rear-side corner portion (11b) located at a lower portion of a rear portion of the first power storage module (11A), the second power storage module (11B) has a front-side corner portion (11a) located at a lower portion of a front portion of the second power storage module (11B), the first protrusion (26) has a front-side base portion (26a) located on a front side and a rear-side base portion (26b) located on a rear side, the front-side base portion (26a) is located at a position overlapping with the rear-side corner portion (11b) in the upward-downward direction, and the rear-side base portion (26b) is located at a position overlapping with the front-side corner portion (11a) in the upward-downward direction.
  2. The power storage device (1) according to claim 1, wherein the cover member (50) includes a second protrusion (52) that faces the first protrusion (26) in the upward-downward direction and protrudes upward.
  3. The power storage device (1) according to claim 2, further comprising a cooler (30) disposed between the bottom wall portion (23) and the cover member (50) to cool the first power storage module (11A) and the second power storage module (11B), wherein the first protrusion (26) protrudes more downward than the cooler (30).
  4. The power storage device (1) according to any one of claims 1 to 3, further comprising: a first cross member (29A1) and a second cross member (29A2) that are disposed on a side close to the inner surface (23a) and spaced apart from each other in the front-rear direction; and a first bottom reinforcing member (25B1) and a second bottom reinforcing member (25B2) that are disposed on a side close to the outer surface (23b) and spaced apart from each other in the front-rear direction to reinforce the bottom wall portion (23), wherein the first cross member (29A1) and the first bottom reinforcing member (25B1) are disposed in the upward-downward direction with the bottom wall portion (23) being interposed therebetween, the second cross member (29A2) and the second bottom reinforcing member (25B2) are disposed in the upward-downward direction with the bottom wall portion (23) being interposed therebetween, the first power storage module (11A) and the second power storage module (11B) are disposed between the first cross member (29A1) and the second cross member (29A2), and the cover member (50) is fixed to the first bottom reinforcing member (25B1) and the second bottom reinforcing member (25B2).

Description

CROSS REFERENCE TO RELATED APPLICATIONS This nonprovisional application is based on Japanese Patent Application No. 2024-173178 filed on October 2, 2024 with the Japan Patent Office, the entire contents of which are hereby incorporated by reference. BACKGROUND Field The present disclosure relates to a power storage device. Description of the Background Art As a conventional power storage device, Japanese Patent Laying-Open No. 2023-046671 discloses a structure in which a power storage stack disposed inside a lower case is cooled by using a cooler disposed below the lower case. The lower case is provided with a protrusion protruding downward, and a protection panel for protecting the cooler is fixed to the protrusion. SUMMARY In the configuration disclosed in Japanese Patent Laying-Open No. 2023-046671, a recess is formed in a portion of a bottom portion of the lower case, and the protrusion is attached to this portion. Thus, there is a concern that, when an upward impact is applied from below onto the protection panel due to road surface interference or the like, the bottom portion may deform so as to warp upward starting from an end portion of the recess of the bottom portion. Such a situation causes a concern that the upwardly warped bottom portion may interfere with a lower surface of the power storage stack (power storage module) inside the lower case, so that the power storage stack may deform. The present disclosure has been made in view of the above-described problems, and an object thereof is to provide a power storage device in which a power storage module can be suppressed from deforming when an external force directed upward is applied from below. A power storage device according to the present disclosure includes: a lower case including a bottom wall portion having an inner surface and an outer surface that are arranged in an upward-downward direction; a first power storage module and a second power storage module that are fixed to the inner surface and spaced apart from each other in a front-rear direction orthogonal to the upward-downward direction; and a cover member to cover the bottom wall portion from below in a state in which a gap is formed between the cover member and the bottom wall portion. The bottom wall portion includes a first protrusion protruding downward. The first protrusion is located between the first power storage module and the second power storage module when viewed from above. The first power storage module has a rear-side corner portion located at a lower portion of a rear portion of the first power storage module. The second power storage module has a front-side corner portion located at a lower portion of a front portion of the second power storage module. The first protrusion has a front-side base portion located on a front side and a rear-side base portion located on a rear side. The front-side base portion is located at a position overlapping with the rear-side corner portion in the upward-downward direction. The rear-side base portion is located at a position overlapping with the front-side corner portion in the upward-downward direction. According to the above-described configuration, when an upward external force is applied to the cover member due to road surface interference or the like, the cover member bumps into the first protrusion, so that deformation of the cover member can be suppressed. The first protrusion is pressed upward by the cover member, but the front-side base portion and the rear-side base portion each have high rigidity, and thus, the bottom wall portion deforms with respect to the front-side base portion and the rear-side base portion serving as fulcrums. At this time, the front-side base portion comes into contact with the rear-side corner portion of the first power storage module, and the rear-side base portion comes into contact with the front-side corner portion of the second power storage module. Due to such deformations, the loads transmitted to the rear-side corner portion of the first power storage module and the front-side corner portion of the second power storage module are respectively transmitted to vertical wall surfaces of the first power storage module and the second power storage module. Thereby, significant deformations of the bottom surfaces of the first and second power storage modules can be suppressed. Further, the vertical wall surfaces each have high strength and thus can cushion a high load. As a result, it is possible to suppress deformation of the power storage module when an upward external force is applied from below. In the power storage device according to the present disclosure, the cover member may include a second protrusion that faces the first protrusion in the upward-downward direction and protrudes upward. According to the above-described configuration, the cover member is readily bumped into the first protrusion by the second protrusion. Thereby, when an upward external force is applied to the cover mem