LIGHTWEIGHT AND RIGID STRUCTURE OF BATTERY UNIT

摘要

A battery unit is provided which includes a battery and a storage case in which the battery is mounted. The storage case is made up of a base, a cover, and an intermediate case. The cover is jointed to the base with an interspace therebetween. The intermediate case is disposed between the cover and the base and has a peripheral wall which occupies the interspace. The intermediate case is lower in stiffness than the cover and the base, thereby realizing a lightweight structure of the storage case without sacrificing the mechanical strength thereof.

主权项

1. A battery unit comprising:
a battery; and a storage case in which the battery is installed, the storage case including a first casing member, a second casing member, and an intermediate casing member, the first casing member defining a bottom of the storage case, the second casing member defining a top of the storage case with the battery disposed between itself and the first casing member, the second casing member being joined to the first casing member so as to create a clearance which extends along a circumference of a peripheral wall of the storage case, the intermediate casing member being disposed between the first casing member and the second casing member to form an intermediate wall that is a portion of the peripheral wall of the storage case, the intermediate casing member being lower in stiffness than the first and second casing members.