Valve system for load-independent hydraulic control of a plurality of

Abstract

A valve system is provided for the load-independent control of a plurality of simultaneously operated hydraulic consumers, i.e. regardless of variations in load pressure. Fluid flow in a consumer line to each consumer passes across a compensating flow control valve, i.e. a compensator. The valve piston thereof being displaceable to the open position by a pressure downstream of a flowmeter against the opposing resistance offered by a spring and by the respective maximum load pressure of the consumers at a time. The actual highest load pressure is also available at a regulator for the common variable displacement supply pump feeding the consumers. In an attempt to ease actuation of the main valves, yet offering the capability to serve different functional requirements by slightly modifying the circuitry and to ensure that insufficient fluid supply from the pump does not exclusively affect the consumer actually subject to the maximum load, the compensator and flowmeter are arranged in a secondary flow path carrying only a fraction of the total consumer fluid supply. The main volume flow rate is regulated by the control edge of greater cross section which moves together with the pressure sensitive displacements of the compensator spool. The control edge is supplied by a valve means capable of reducing fluid pressure in a primary supply line to the pressure level downstream of the flowmeter.