OIL PRESSURE CIRCUIT AND PROCESSING METHOD OF HYDRAULIC JACK

摘要

PURPOSE: A hydraulic circuit and a hydraulic jack system operating method are provided to regulate the operating speed of a hydraulic jack without using an electronic control device or sensor by controlling the flow rate supplied to a cylinder of the hydraulic jack. CONSTITUTION: A hydraulic circuit(150) comprises a hydraulic feeding unit(110), a direction control valve(120), a first supply line(130) or a second supply line(140), flow control valves(131,141), and pressure control valves(132,133,142). The hydraulic feeding unit comprises an oil tank and a pump. The direction control valve controls the discharge and intake directions of work oil between the hydraulic feeding unit and the supply line according to operating states. The first supply line is connected from the hydraulic feeding unit through the direction control valve to the head portion(101) of a hydraulic jack(100). The second supply line is connected from the hydraulic feeding unit through the direction control valve to the rod portion(102) of the hydraulic jack. The flow control valves are parallely arranged in the pressure control valves and control the flow rate of working oil when opening and closing the pressure control valves. The pressure control valves open and close in order to allow or block the supply of working oil to the hydraulic jack according to loads applied to a piston.