Electric water mouth operating device and water mouth operating method for hydraulic machine

摘要

PROBLEM TO BE SOLVED: To provide an electric waterport operating device having high reliability and low cost. SOLUTION: Each of operating pipes 6 and 7 for supplying oil pressure is provided with each of loop pipes 6a and 7a bypassing a two-direction rotation type hydraulic pump 3. Branch ducts 8 and 11 are disposed in the loop pipes. The duct 8 is provided with a first check valve 9 for blocking oil discharged from a rod side port 4a of a hydraulic cylinder 4 and a second check valve 10 for blocking oil discharged from a head side port 4b of the hydraulic cylinder 4. The duct 11 is provided with a third check valve 12 for blocking oil flowing into the rod side port 4a of the hydraulic cylinder 4 and a fourth check valve 13 for blocking oil flowing into the rod side port 4a of the hydraulic cylinder 4. A connecting pipe 16 for connecting between the first and second check valves 9 and 10 and between the third and fourth check valves 12 and 13 is provided, the connecting pipe 16 is provided with a relief valve 14, and its extending part 16a is provided with an oil tank 15 as a buffer device.