| 摘要 |
PROBLEM TO BE SOLVED: To safely and reliably cleave a gas discharge valve.SOLUTION: Regions D1, D2, S1, and S2 are formed in a shape of a convex-shaped curved surface smoothly protruding toward the outside. When heat is generated by shorting or the like to cause an electrolyte to evaporate, internal pressure p of a case 1 rises, the regions is pushed outward (pressing force indicated by FP). In an inside concave part 11, tensile stress &sgr; is generated in a direction along inclination of an inner peripheral edge part of the regions, and cleavage force FT is generated by the stress in the inside concave part 11. In other words, by forming the regions D1, D2, S1, and S2 so as to have the convex-shaped curved surface convex toward the outside, stress in a direction where the inside concave part 11 is cleaved is generated to generate cleavage force as the sum total of the stress. |
