HYDRAULIC CIRCUIT

PROBLEM TO BE SOLVED: To provide a switching type hydraulic circuit for driving by connecting an oil tank unit to a selected hydraulic driving device between the oil tank unit and a plurality of hydraulic driving devices. SOLUTION: This hydraulic circuit has a tank unit 15 having a circulating circuit 13 for circulating oil of an oil storage tank 11 and a flushing means 14 for removing foreign matter in the oil, and a hydraulic control unit 25 having a high pressure pump 21 arranged in close vicinity to a valve stand 18 of an actuator 17 and pressurizing the oil flowing in from a connecting pipe 20 connected to the circulating circuit 13 via a first self-seal coupling 19, a high pressure pipe 22 supplying the oil from the high pressure pump 21 to the valve stand 18 and a return pipe 24 connected to the valve stand 18, connected to the circulating circuit 13 via a second self-seal coupling 23 and making the oil from the actuator 17 flow in the circulating circuit 13. A bypass circuit 27 is arranged via a switching valve 26 between the connecting pipe 20 and the return pipe 24. COPYRIGHT: (C)2010,JPO&INPIT