초록 ▼

A hydraulic flow control valve is disclosed which is adapted for use as a pressure reducing valve, a flow control valve, or as a pressure relief valve. The valve includes a choke piston slidably mounted in a cylindrical bore for movement between a closed position closing communication between inlet

A hydraulic flow control valve is disclosed which is adapted for use as a pressure reducing valve, a flow control valve, or as a pressure relief valve. The valve includes a choke piston slidably mounted in a cylindrical bore for movement between a closed position closing communication between inlet and outlet channels, and an open position permitting such communication. An adjustable control system is provided for biasing the piston toward one of either its closed or open positions, and includes a constant volume flow restriction valve for providing a constant volume hydraulic flow. Downstream of the constant volume flow valve, there is provided a first branch line leading to an adjustable transducer for maintaining a selected pressure in the line, and a second parallel branch line leading to the bore in the housing for biasing the piston. Thus a selected pressure may be maintained in the second line, and thus also upon the piston, by adjustment of the transducer.

대표청구항 ▼

A hydraulic flow control valve comprising a housing having a bore therein, a hydraulic inlet channel and a hydraulic outlet channel, each communicating with said bore in said housing, valve means mounted in said bore for movement between a closed position closing communication between said inlet and

A hydraulic flow control valve comprising a housing having a bore therein, a hydraulic inlet channel and a hydraulic outlet channel, each communicating with said bore in said housing, valve means mounted in said bore for movement between a closed position closing communication between said inlet and outlet channels, and an open position permitting such communication, adjustable control means for biasing said valve means toward one of either its closed or open positions, and including, (a) constant volume flow restriction means for providing a constant volume hydraulic flow, (b) a first line connected downstream of said constant volume flow restriction means, (c) adjustable transducer means operatively connected to said first line for maintaining a selected pressure therein, (d) an outlet line leading from the downstream side of said transducer means to an external reservoir, (e) a second line connected downstream of said constant volume flow restriction means and parallel to said first line, said second line leading to said bore in said housing and so that the pressure in said second line is adapted to bias said valve means toward one of either its closed or open positions, (f) flow sensor means and pressure sensor means positioned in said outlet channel, and (g) feedback means operatively interconnecting each of said flow sensor means and said pressure sensor means with said transducer means, and including switch means for selectively connecting either said flow sensor means or said pressure sensor means to said feedback means, whereby the output of either said flow sensor means or said pressure sensor means acts to control the pressure in said second line and thus positioning of said valve means.