Pressure reducing valve

摘要

A pressure reducing valve 20 is constructed such that a piston 22 is provided within a housing 21 provided with a primary port 28 and a secondary port 30 to form a primary pressure chamber 64 of a primary pressure P1 and a secondary pressure chamber 70 of a secondary pressure P2 which are connected to each other through an orifice 63. The piston 22 is subjected to the primary pressure P1 applied in one direction X1 in the axial direction and the secondary pressure P2 applied in the opposite direction X2 in the axial direction. A spring 23 exerts a force to the piston 22 in the direction X1. A back pressure chamber 55 is kept at the primary pressure P1 to cause the primary pressure P1 to be applied to the piston 22 in the opposite direction X2.