초록 ▼

A pilot stage of an electrohydraulic control valve controls the position of a pilot actuated main stage by controlling fluid flow through a flow path that connects a supply port to an exhaust port and to an end of the main stage. A proportional valve of the pilot stage has a valve element for establ

A pilot stage of an electrohydraulic control valve controls the position of a pilot actuated main stage by controlling fluid flow through a flow path that connects a supply port to an exhaust port and to an end of the main stage. A proportional valve of the pilot stage has a valve element for establishing a variable flow control orifice to control fluid flow through the flow path and a bleed orifice disposed in the flow path downstream of the proportional valve to generate fluid pressure upstream of the bleed orifice and at the end of the main stage.

대표청구항 ▼

[ I claim:] [1.] A pilot stage of an electrohydraulic control valve for controlling the position of a pilot actuated main stage comprising;a supply port;an exhaust port;a flow path connecting the supply port with the exhaust port and to an end of the main stage;a proportional valve disposed in the f

[ I claim:] [1.] A pilot stage of an electrohydraulic control valve for controlling the position of a pilot actuated main stage comprising;a supply port;an exhaust port;a flow path connecting the supply port with the exhaust port and to an end of the main stage;a proportional valve disposed in the flow path to control fluid flow therethrough, the proportional valve includes an annular valve seat disposed in the flow path, an anti-leak valve element operative to engage the annular valve seat, and a proportional solenoid disposed to selectively control the position of the anti-leak valve element relative to the annular valve seat against the force of the flow from the supply port; anda bleed orifice disposed in the flow path downstream of the proportional valve and between the end of the main stage and the exhaust port.