SAFETY VALVE OF SEALED BATTERY

摘要

PROBLEM TO BE SOLVED: To prevent a metal foil from being damaged or deformed by external contact to cause the occurrence of defective quality on the sealing property and cleavage pressure accuracy as a safety valve and to improve safety and a yield in mass machining when part of the metal foil is protruded from the upper and lower faces of a base material after cold welding in a cleavage type safety valve formed by the cold welding of the metal foil. SOLUTION: Protruded shapes 7 are provided on a surrounding base material 2 by press machining to protect a metal foil 1 protruded from the upper face and lower face of a base material after cold welding. A region including the protruded metal foil 1 and a cold welded section around it is protrusively molded in steps by press machining, thereby the metal foil 1 is prevented from being damaged or deformed by external contact.