To suppress pressure variation with minor changes in an existing hydraulic circuit, operable over a wide pressure range and miniaturizable as compared to an accumulator.
When pressure in an oil passage 11 rises, a piston 3 displaces with pressure Pc over the spring set pressure Pc0 and the volume of a volume chamber 2 begins to increase with the subsequent volume increasing proportional to the pressure increase of the pressure Pc. As a result, pressure variation in the oil passage 11 is absorbed and attenuated. The pressure oil with the pressure variation attenuated is then outputted to an oil passage 12 through an output port C2 of the volume chamber 2. Consequently, pilot pressure oil with the pressure variation suppressed is supplied to the pilot port 22a of a control valve 22, so that the vibration resulted from the hydraulic device to be controlled is suppressed.
ISOBE DAISAKU
HORI HIDEJI
