To use a hydraulic cylinder of internal diameter smaller than the internal diameter of a conventional hydraulic cylinder and attain saving of energy by reducing a use amount of pressure fluid.

A device is constituted by having the first piston 24 dividing the first cylinder chamber 41 into the first/second fluid chambers 42, 43, second piston 26 dividing the second cylinder chamber 44 having a diameter larger than that of the first cylinder chamber into the third/fourth fluid chambers 45, 46, first to the fourth ports 51 to 54, communication path 61 connecting the first/fourth ports 51, 54, throttle flow path 62 connecting between the first/ third ports 51, 53 and check valve 64 generating a free flow toward the second port 52 from the third port 53.