| 摘要 |
PROBLEM TO BE SOLVED: To provide a sealed rectangular battery for preventing any accident thereof caused by breakage of its metal case by certainly opening its safety valve, in a simple structure at a low cost. SOLUTION: A sealed rectangular battery is provided with a rectangular metal case 1 having an opening part, a port closing lid 2 welded to the opening part and blocked, a power generation element enclosed in a rectangular metal case 1 and a safety valve 4 for preventing any internal pressure rise by opening when the inside pressure of a battery rises abnormally. The weld strength of one side of the port closing lid 2 welded to the rectangular metal case 1 is made smaller than those of other sides and when the inside pressure of the battery is increased abnormally, this side is cut and one part of the welded part of the port closing lid 2 to the rectangular metal case 1 are broken and the inside gas is exhausted smoothly. Since the safety valve 4 is self-recovery unit after operation of the valve, the operational pressure for opening the safety valve 4 is set lower than the pressure by which the side of smaller weld strength is broken. |
