US Patent 8128056 Flow control valve

Provided is a flow control valve including: a valve body including a flow passage; a first poppet being fixed within the valve body, and including an inlet port through which a fluid flows in and an outflow hole through which the fluid flows out to the flow passage; a second poppet being fixed within the valve body, and including an outlet port through which the fluid flows out and an inflow hole through which the fluid flows in from the flow passage; a sleeve sliding along the first poppet to close the outflow hole and regulate an area thereof; and a spool being disposed between the first and second poppets to be slidable along the first and second poppets, being elastically supported by the second poppet, and sliding due to a pressure of the fluid flowing in the first poppet to close the inflow hole and regulate an area thereof.