Fluid-filled vibration isolator

Abstract

A fluid-filled vibration isolator includes a hollow, thick-walled, rubber body which opens downwardly, an annular side plate which has an upper part bonded to an outer surface of the rubber body, a bottom plate sealed to a lower end edge of the cylindrical side plate by caulking, a partition, and a rubber diaphragm. Peripheral edges of the partition and the diaphragm are both strongly sandwiched by the lower end edge to define a main fluid chamber between the rubber body and the partition and an auxiliary fluid chamber between the partition and the rubber diaphragm. A lower part of the side plate inclines obliquely and outwardly toward the lower end edges. A peripheral part of the partition bends into an L-shaped cross-section and contacts the obliquely and outwardly inclining lower part to define an annular space having a closed triangular cross-section. The annular space is blocked circumferentially by a projecting wall formed in the partition. The annular space opens into the main fluid chamber through a recess formed in the partition adjacent to the projecting wall and opens into the auxiliary fluid chamber through a through hole formed in the partition on the side of the projecting wall opposite to the recess to define a throttle passage interconnecting the main fluid chamber and the auxiliary fluid chamber.