Hydraulic control valve system with pressure compensated flow control

摘要

An assembly of valves controls hydraulic fluid flowing to several hydraulic actuators from a variable displacement pump that produces an output pressure equal to a control input pressure plus a predefined margin pressure. The control input pressure is a function of the greatest load pressure at the hydraulic actuators. Each valve has an associated pressure compensating valve which regulates the pressure differential across a metering orifice of each valve to a predefined level, usually the pump's margin pressure. A flow regulator is associated with at least one of the valves and reduces the output pressure from the pump to produce a reduced pressure that controls the associated pressure compensating valve. Operation of the flow regulator causes the pressure differential across a metering orifice of the associated valve to be less than the pump's margin pressure thus allowing adjustment of the fluid flow.