SOLENOID-DRIVEN FLOW RATE CONTROL VALVE

摘要

A solenoid-driven flow rate control valve (1) controls, in response to excitation of a solenoid (S), the flow rate of an operating fluid flowing from a second port (13) to a first port (12).  A pilot pin (60) of a pilot valve (V3) driven by the excited solenoid (S) regulates an auxiliary pilot pressure.  An auxiliary valve (V2) changes the degree of opening thereof according to the auxiliary pilot pressure, causes the operating oil to flow out of the second port (13) to the first port (12), and changes a main pilot pressure according to the flow rate of the flowing out operating oil.  The main valve (V1) changes the degree of opening thereof according to the main pilot pressure and causes the operating oil to flow out of the second port (13) to the first port (12).  Since the valves are operated in sequence according to the flow rate, highly accurate flow rate control for a small flow rate and highly responsive flow rate control for a large flow rate are realized.