Flow control valve with a pressure compensation function

摘要

A flow control valve having a pressure compensation function. This valve is free of fluid leakage and needs no pressure sensor. This valve includes a housing having a first port and a second port, a piston axially slidably mounted in the housing, a valve body formed at one end of the piston, a first fluid chamber defined between the other end of the piston and the housing, a second fluid chamber defined between the valve body and the housing, a variable-area orifice formed on the outer periphery of the piston and adapted to close when the piston is at a predetermined axial position, thereby shutting off the first fluid chamber and the first port from each other, a connecting path formed in the piston to communicate with the variable-area orifice and connecting the first fluid chamber with the second fluid chamber through a fixed- area orifice, an on-off valve comprising the valve body and a valve seat, a biasing means biasing the on-off valve at all times in a direction to open the on-off valve, and an electromagnetic biasing means for controlling the movement of the piston toward the biasing means.