OPERATING DEVICE FOR CIVIL ENGINEERING WORK AND CONSTRUCTION MACHINERY

摘要

PURPOSE:To join pressure oils in a convergent circuit even when operating force is small by using a system in which a pressure generator is provided between the tank port of one direction switch valve and a tank, and by its generated pressure, the servo valve of the other direction switch valve is operated. CONSTITUTION:In case where pressure oils from plural direction-switch valves 7 and 8 are joined in one actuator 6, a pressure generator consisting of relief valve 17 is provided between the tank port 18 of one-direction switch valve 7 and a tank 5, the direction switch valve 7 is switched through a switch rod 9, and the pressure oil of an oil-pressure pump 1 is supplied through the switch valve 7 to the actuator 6. In the return pipeline, by pressure produced in the relief valve 17, a servo valve 19 operating the other converging switch valve 8 is actuated and the switch valve 8 is switched. Thus, the switching of the other direction- switch valve 8 can also be concurrently performed only by the switch operating performance of one-way switch valve 7.