Patent ID: 8770221

Claim:
A pressure regulating valve, comprising: a case that includes a primary chamber and a secondary chamber; a valve moving member that includes a piston and a valve element, wherein: the valve moving member moves in such a manner as to cause communication or block communication between the primary chamber and the secondary chamber within the case, and one end of the piston faces the secondary chamber and the other end faces a reference pressure chamber; a plurality of seal members arranged between said case and said valve moving member, wherein: said plurality of seal members are made of different materials, and said plurality of seal members are arranged between a side surface of said piston and an inner wall case; and communicating means for causing a space and said reference pressure chamber to communicate, wherein: the space is defined by said side surface of said piston, said inner wall of said case and said plurality of seal members, the communicating means is formed in a body of the case, and the communicating means is configured to connect the space and the reference pressure chamber such that a pressure of the space is regulated when the piston moves, wherein the communicating means is formed at an inner wall surface of the body of the case at a location of a first seal member of the plurality of seal members on a side of said reference pressure chamber, and the communicating means is formed by undulations so that gas can communicate between the s ace and the reference pressure chamber.