| 摘要 |
PROBLEM TO BE SOLVED: To prevent rupture of a battery by displacing a diaphragm part when inner pressure in a battery case rises higher than a prescribed value, pressing an insulator, breaking a lead portion from a break inducing portion, and cutting off a cable way. SOLUTION: When inner pressure rises due to occurrence of abnormality in a battery case, gas with high pressure intrudes through a ventilation groove 2c into a recessed part 1d in an upper diaphragm part D, and a force for pressing up a thin part 1e of the diaphragm part D operates. When the inner pressure of a battery rises higher than a prescribed value, the inner pressure inverts the diaphragm part D upward all at once. Due to this upward inversion, the central part of the diaphragm part D presses a projecting surface 7b of an insulator 7, and a lead portion 6b is broken from a break-inducing portion 6d. After the breaking, the insulator 7 side is pressed up and separated from the lead portion 6b on a holding member 3 side, and the lead portion 6b cuts off a cable way between a power generating element and a terminal portion in the battery case. This cut-off of the cable way suppresses rising of the inner pressure in the battery case.
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