Patent ID: 7588235
Filing Date: 2009-09-15
Classification: F16F

Abstract:
1. A fluid filled type vibration-damping device comprising: a first mounting member; a second mounting member of round tubular shape, disposed such that the first mounting member is located on a side of an opening at one end of the second mounting member; a main rubber elastic body elastically connecting the first mounting member and the second mounting member, and fluid-tightly sealing off the opening at one end of the second mounting member; a flexible film fluid-tightly sealing off an opening at an other end of the second mounting member; a partition member inserted into and firmly fitted into the second mounting member thereby forming to one side of the partition member a pressure-receiving chamber whose wall is defined by the main rubber elastic body and having a non-compressible fluid sealed therein, while forming to an other side of the partition member an equilibrium chamber whose wall is defined by the flexible film and having the non-compressible fluid sealed therein; an orifice passage connecting the pressure-receiving chamber and the equilibrium chamber, and being formed by utilizing the partition member; a short circuit passage of shorter flow passage length than the orifice passage being formed so as to connect the pressure-receiving chamber with the equilibrium chamber, with an opening of the short circuit passage into the pressure-receiving chamber being situated in an outside peripheral portion of a face of the partition member on a pressure-receiving chamber side; and a center recess formed in a center of the main rubber elastic body on a face thereof facing the partition member, wherein a peripheral edge of an opening of the center recess of the main rubber elastic body constitutes a valve body of the short circuit passage configured such that: the peripheral edge of the opening of the center recess of the main rubber elastic body is superposed against the outside peripheral portion of the partition member on the face thereof facing the pressure-receiving chamber side for sealing off the opening of the short circuit passage which opens into the pressure-receiving chamber, and when an excessive negative pressure arises in the pressure-receiving chamber and an excessive pressure differential arises between the pressure-receiving chamber and the equilibrium chamber, excess tensile force acts on the main rubber elastic body in a direction pulling it outward in the axial direction so that the peripheral edge of the opening of the center recess of the main rubber elastic body opens to place the short circuit passage in the communicating state on a basis of elastic deformation of the main rubber elastic body.