| 摘要 |
A hydraulic control valve assembly (10), method and system, characterized by control valves (26) each having a variable metering orifice; a compensator (28) that controls flow of fluid from the variable metering orifice to a work port (A,B) in response to a differential in pressures acting on opposite first and second sides of the compensator, wherein a first side receives a pressure at the downstream side of the variable metering orifice; a load sense passage (34) providing a load sense pressure; and a differential pressure controller (40) having a first inlet connected to a pump supply port and a second inlet connected to the load sense passage, the controller having a first operational mode in which load sense pressure at the second inlet is supplied to an outlet of the controller and a second operational mode in which flow from the first inlet is metered to the outlet of the controller to provide a differential control output pressure, and wherein an outlet of the differential pressure controller is connected to a pump control port and/or to the second side of the pressure compensating valve of at least one of the control valves.. |
