Patent ID: 7306210

Claim:
A fluid filled type vibration damping device comprising: a first mounting member; a second mounting member; a main rubber elastic body elastically connecting the first and second mounting members; a partition member supported by the second mounting member; a pressure-receiving chamber whose wall is partially defined by the main rubber elastic body and having a non-compressible fluid sealed therein; an equilibrium chamber whose wall is partially defined by a flexible film and having the non-compressible fluid sealed therein, the chambers being formed to either side of the partition member; an orifice passage formed utilizing the partition member and permitting a fluid communication between the pressure-receiving chamber and the equilibrium chamber; a short-circuit passage formed in the partition member so that the pressure-receiving chamber and the equilibrium chamber communicating through the orifice passage are able to be short-circuited through the short-circuit passage; a valve furnished for switching the short-circuit passage between an open state and a closed state; and a metal spring furnished for holding the valve in the closed state at a predetermined initial level of elastic deformation, wherein the valve is held in the closed state by means of elastic force based on the predetermined initial level of elastic deformation of the metal spring, and when the pressure-receiving chamber generates negative pressure whose absolute value is greater than a predetermined negative pressure that is determined based on the elastic force of the metal spring, the valve is held in the open state for communicating the pressure-receiving chamber and the equilibrium chamber through the short-circuit passage.