| 摘要 |
PROBLEM TO BE SOLVED: To provide an explosion proofing structure which can form an explosion-proof safety valve which releases inner pressure when the internal pressure of the electrochemical element is extraorninarily built up, at the same time when its rectangular case is injection-molded. SOLUTION: Let a function as an explosion proof safety valve be most effective by letting at least one corner part 2a out of the four outside corner parts of a rectangular case 1, be made thinner 5 than the other corners. Or let a function as the explosion proof safety valve be most effective by letting the radius of curvature of at least one inner side corner part 4a out of the four inner side corner parts of the rectangular case, be made smaller than the radius of curvature for the other inner side corner parts. Or the aforesaid respective structures are combined with each other. Or, at least, either one of the side surfaces wide in width of the case is made thinner in thickness at its center part lengthwisw along its longer direction, than the other portions of the case. |
