Patent ID: 6978607

Claim:
A hydraulic control system, comprising: a hydraulic actuator configured to perform a predetermined operation by means of pressure oil supply; an operation command unit configured to control the predetermined operation of the hydraulic actuator by providing a first control operation signal indicative of a highest pressure oil; a directional control valve unit, including a directional control valve, configured to supply pressure oil to the hydraulic actuator in response to the first control operation signal; a variable displacement hydraulic pump configured to supply pressure oil to the directional control valve unit; a discharge rate control unit that changes a discharge rate of the variable displacement pump in response to the first control operation signal; a differential pressure generating unit configured to generate a differential pressure between pressure at a discharge side of the variable displacement hydraulic pump and pressure in pressure oil supplied to the hydraulic actuator from the directional control valve and to output a second control operation signal indicative of the differential pressure; a control quantity correcting unit configured to correct the first control operation signal to the discharge rate control unit from the operation command unit based on the second control operation signal outputted by the differential pressure generating unit, wherein the discharge rate of the variable displacement hydraulic pump is adjusted, via the discharge rate control unit, based on the corrected first control operation signal.