Patent ID: 9243680
Filing Date: 2016-01-26
CPC Classification: F16F

Claim Text:
1. A fluid-filled type active vibration damping device comprising: a first mounting member; a second mounting member; a main rubber elastic body connecting the first mounting member and the second mounting member; a pressure-receiving chamber whose wall is partially defined by the main rubber elastic body and filled with a non-compressible fluid; an equilibrium chamber whose wall is partially defined by a flexible film and filled with the non-compressible fluid; an orifice passage permitting fluid flow of the non-compressible fluid between the pressure-receiving chamber and the equilibrium chamber; an oscillation member adapted to be oscillated by an electromagnetic actuator; an intermediate chamber whose wall is partially defined by the oscillation member and filled with the non-compressible fluid; a pressure transmission passage through which pressure fluctuations produced in the intermediate chamber is adapted to be applied to the pressure-receiving chamber, wherein the intermediate chamber is provided independently of the equilibrium chamber such that there is no connecting passage that directly interconnects the intermediate chamber and the equilibrium chamber; wherein the pressure transmission passage comprises a filter orifice tuned to higher frequency than the orifice passage; wherein a movable plate is provided for limiting an amount of fluid flow through the filter orifice; wherein a leak hole is formed for continuously interconnecting the intermediate chamber and the pressure-receiving chamber, and a liquid column resonance frequency of the leak hole is set to not more than half of that of the filter orifice; wherein the leak hole provides continuous uninterrupted communication between the intermediate chamber and the pressure-receiving chamber, and the leak hole being configured to release a blocking of the filter orifice by the movable plate by dispelling a differential in fluid pressure between the pressure-receiving chamber and the intermediate chamber; and further comprises a housing recess defined by a partition member body and a cover member, the movable plate being enclosed within the housing recess, and the leak hole being defined by an upper hole penetrating to the cover member while being located radially outside of a rim of the movable plate, a lower hole penetrating the partition member body while being located radially outside of the rim of the movable plate, and a middle communication portion that is defined by a portion of the housing recess partially expanded in diameter in a circumferential part where the upper hole and the lower hole are formed so that the upper hole and the lower hole continuously communicate with each other via the middle communication portion, and the middle communication portion is further defined as a slot that opens upward, wherein the slot is formed in an outside peripheral portion of the partition member body, and the slot extends radially from a circumference of the partition member body.