Patent ID: 7416173
Filing Date: 2008-08-26
Classification: F16F

Abstract:
1. A pneumatically switchable type fluid-filled engine mount, comprising: a first mounting member attachable to one of a power unit side member and a vehicle body side member; a second mounting member attachable to another of the power unit side member and the vehicle body side member; a rubber elastic body elastically connecting the first mounting member and the second mounting member; a pressure receiving chamber partially defined by the rubber elastic body, filled with a non-compressible fluid, and subjected to input of vibration; an equilibrium chamber partially defined by a flexible layer for readily permitting change in volume thereof, and filled with the non-compressible fluid; a first orifice passage for fluid communication between the pressure receiving chamber and the equilibrium chamber, tuned to a low frequency range generally corresponding to engine shake; a second orifice passage for fluid communication between the pressure receiving chamber and the equilibrium chamber, tuned to a medium frequency range generally corresponding to idling vibration; a valve member for opening/closing the second orifice passage; a pneumatic actuator operated by air pressure from the outside, for driving the valve member; a movable partition member whose center portion constitutes a rigid center movable plate portion and whose outer peripheral portion constitutes a readily deformable outer peripheral rubber film portion, disposed so that an outer peripheral edge of the outer peripheral rubber film portion is supported fluid-tightly by the second mounting member, permitting displacement and deformation in the center movable plate portion and the outer peripheral rubber film portion, the movable partition member defining another part of the pressure receiving chamber; and an intermediate equilibrium chamber formed on an opposite side of the movable partition member from the pressure receiving chamber with the movable partition member interposed between the intermediate equilibrium chamber and the pressure receiving chamber, wherein an elastic contact projection is formed projecting out from an outer peripheral edge portion of the center movable plate portion in the movable partition member, the elastic contact projection being positioned in contact against the second mounting member or a displacement restricting member supported by the second mounting member, thereby providing a displacement limiting member for cushion-wise limitation of an extent of displacement of the center movable plate portion, a rigid constriction plate is disposed in the center movable plate portion of the movable partition member, with the outer peripheral rubber film portion being bonded to the constriction plate, a plurality of elastic contact support portions are integrally formed projecting out from the outer peripheral edge portion of the center movable plate portion in the movable partition member with a projection height greater than that of the elastic contact projection at both sides as measured in a thickness direction of the center movable plate portion, and the elastic contact support portions are held in contact with the second mounting member or the displacement restricting member supported by the second mounting member so that the rigid constriction plate of the center movable plate portion is elastically supported by the elastic contact support portions.