Hydraulic valves
AssigneeMicrohydraulics, Inc.
InventorGeorge Kadlicko
Life of this patent
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Abstract
A hydraulic valve includes a spool movable within a body to regulate flow across the valve. Movement of the spool is controlled by an electromagnetic actuator that operates either directly or through a pilot stage upon the spool. When operating through a pilot stage, the actuator varies pilot pressure by an operating member co-operating with an orifice. A flapper valve may be used to vary a pair of pilot flows in complementary manner. Feedback signals of pressure and spool position are provided to a controller which selectively combines the signals to monitor the operating parameters of the valve. The controller may modify the position signal with the pressure signal to obtain an indication of flow rate through the valve.
Claims24
A hydraulic valve having a body, a valve member movable within the body to control flow through a pair of ports in said body, an electromagnetic actuator operable upon said valve member and receiving electrical control signals from a controller to modulate the position of said valve member relative to said body, a transducer associated with said valve member to provide a feedback signal indicative of a predetermined parameter to said controller, said controller utilizing said feedback signal to modulate said electrical control signals to said actuator to maintain a hydraulic parameter at a predetermined value, said valve member including a first spool movable relative to said body to connect selectively said ports and having a first pair of chambers formed between said body and said first spool and located at opposite ends thereof, a control spool slidably mounted in said first spool and moveable relative thereto to control flow of fluid to said first pair of chambers, a second pair of chambers formed between said body and said control spool at opposite ends thereof, said actuator modulating pressure of fluid in respective ones of said second chambers to adjust the position of said control spool and thereby said first spool in response to variations in said feedback signal.
Dependencies are inferred from the claim text.