Load sense pressure controller

Abstract

DANA 90 A load sense pressure controller used with a hydraulic control valve such as a hydraulic direction control valve includes a body in the form of a barrel having a threaded first end and a threaded second end. An externally threaded first plug is threaded into the first end of the body and an externally threaded second plug is threaded into the second end of the body. Both first and second plugs each have passages therethrough wherein the passage through the first plug is connected to the load sense passage from a valve and the passage through the second plug is connected to a tank passage in the control valve. Disposed between the first and second plugs is a piston which is biased by a coil spring toward the first plug. The piston has a stepped axially extending passage extending therethrough which is intersected by a radially extending passage. The radially extending passage normally aligns with lateral openings in the body so that when there is a load sense condition, hydraulic fluid flows through lateral openings in the body to the return passage. If the load sense pressure exceeds a selected high pressure, then all of the load sense fluid is throttled through the pressure controlling orifice in the piston to the tank passage of the control valve.