Patent attributes
Disclosed is a hydraulic control circuit and method thereof for reducing heat generation and energy losses caused by overload. The hydraulic control circuit of the present invention includes a control lever for generating a manipulated signal according to a manipulated variable; a control valve driven by a pilot signal pressure for controlling a flow of the pressurized fluid traveling from the hydraulic pump to the actuator; a displacement sensor for detecting a switching position of the control valve; a pump pressure sensor for detecting a pump pressure applied to the hydraulic pump; an electronic proportional valve for supplying a pilot signal pressure to the control valve; and a controller for receiving the manipulated signal, determining a pilot signal pressure, outputting a control signal to the electronic proportional valve, receiving signals from the displacement sensor and the pump pressure sensor and comparing the signals with pre-stored reference data, and outputting to the electronic proportional valve a stroke error correcting control signal for adjusting the switching position of the control valve.
