To simplify the constitution of a valve element having a relief valve mechanism and obtain a desired valve opening characteristic, regardless of surrounding materials and shapes.
A cylindrical end part 33 of a protector 32 of an element assembly is inserted and assembled in the direction of the depth end of a groove part 45 of a valve element 40. A passage 35 of the cylindrical end part 33 of the protector 32 is covered and a relief valve part 41 of the valve element 40 is constituted because a seal part 42 is elastically deformed from a tip part 43 via a guide part 44 and the seal part 42 is made to reach a wall surface after the seal part 42 passes the passage 35 of the cylindrical end part 33 of the protector 32 at this time. Therefore, the relief valve part 41 of the valve element 40 is easy in a mold constitution and can be assembled without excess force, and a desired valve opening characteristic can be stably obtained.
FUNAE KEIZO
YAMAGUCHI SHUJI
TOMITAKA KOICHI
