Abstract: An elastic partition member located in the partition member is integrally provided with a relief valve that opens and closes a leak passage to suppress the generation of the cavitation phenomenon. A pair of relief valves is formed in a crescent shape on the outer circumferential side of the movable diaphragm section in opposed relation. The crescent shape of the relief valve is formed by an inner circumferential side of elliptical arc shape and an outer circumferential side of circular arc shape. A valve length of the relief valve varies in the longitudinal direction such that a middle portion in the longitudinal direction is largest. is easily deformed when the extraordinary vibration is inputted. Each end portion in the longitudinal direction of the relief valve is short in valve length and high in rigidity whereby to prevent the leak when the normal vibration is inputted.

Abstract: An elastic partition member located in the partition member is integrally provided with a relief valve that opens and closes a leak passage to suppress the generation of the cavitation phenomenon. A pair of relief valves is formed in a crescent shape on the outer circumferential side of the movable diaphragm section in opposed relation. The crescent shape of the relief valve is formed by an inner circumferential side of elliptical arc shape and an outer circumferential side of circular arc shape. A valve length of the relief valve varies in the longitudinal direction such that a middle portion in the longitudinal direction is largest. is easily deformed when the extraordinary vibration is inputted. Each end portion in the longitudinal direction of the relief valve is short in valve length and high in rigidity whereby to prevent the leak when the normal vibration is inputted.

Abstract: Antivibration rubber device provided between a vibration source and a vehicle body is provided with: a first mounting member (11) which is mounted to the vibration source side; an elastic member (13) which is in close contact with a surface of the first mounting member (11) and has a step formed at the end part on the vibration source side; and a second mounting member (12) which is integrally connected to the vehicle body side, thereby suppressing occurrence of a crack in the elastic member of the antivibration rubber device and improving durability enabling long-term use.