Fluid filled vibration damping device

Abstract

A fluid filled vibration-damping device includes an elastic body disposed between a first mounting member and a second mounting member and partially defines a fluid chamber having a non-compressible fluid sealed therein, and exhibits vibration damping action on the basis of flow action of the non-compressible fluid created within the fluid chamber during vibration input. At least one mounting member from among the first and second mounting members is formed independently of the elastic body and is disposed in abutment with the elastic body in an initial load acting direction, while making the mounting member displaceable away from the rubber elastic body in a opposite direction from the initial load acting direction. A rebound stop mechanism for limiting displacement of the mounting member away from the rubber elastic body in a cushion-wise fashion is disposed between the first and second mounting members.

Description

INCORPORATED BY REFERENCE[0001] The disclosure of Japanese Patent Application No. 2003-188520 filed on Jun. 30, 2003 including the specification, drawings and abstract is incorporated herein by reference in its entirety.BACKGROUND OF THE INVENTION[0002] 1. Field of the Invention[0003] The present invention pertains to a fluid filled vibration damping device that exhibits vibration damping effect on the basis of flow action of a non-compressible fluid sealed therein, and in particular relates to a fluid filled vibration damping device suitable for use in an automotive engine mount, body mount, or cab mount, for example.[0004] 2. Description of the Related Art[0005] There have been widely used in a variety of fields vibration damping devices each having a rubber elastic body disposed between first and second mounting members fixable to components connected together in vibration isolating fashion. As one type of such vibration damping devices, there is known a fluid filled vibration da...

AI Technical Summary

Benefits of technology

[0010] It is therefore one object of this invention to provide a fluid-filled vibration-damping device, which is novel in construction, and which is capable of moderating deterioration in damping performance thereof during input of high load in the direction opposite from the initial load input direction.

Problems solved by technology

Extensive researches conducted by the inventors has revealed that the fluid filled vibration damping devices of conventional design may possibly suffer from deterioration in the damping performance, when a relatively large load is input to the rubber elastic body in the opposite direction (rebound direction) from the direction in which initial load is exerted (bound direction) due to the distributed support load of a power unit, that is, in the direction that expands the volume of the fluid chamber.

Therefore, when a relatively large load is input in the opposite direction from the direction in which initial load is exerted on the rubber elastic body, the sealed fluid undesirably exerts constraining force on the rubber elastic body in a direction tending to inhibit elastic deformation of the elastic body.

This creates a rubber elastic body dynamic spring constant that is greater than that of a rubber elastic body alone, resulting in deterioration in damping performance.

In the case of a mounted type fluid-filled vibration damping device of a design wherein negative pressure is generated within the fluid chamber in the event of a large load input in opposition to the rebound direction, there are a risk that the resultant large negative pressure created within the fluid chamber will result in separation and bubble formation of air component contained in the sealed fluid, and a risk of problems with noise and shock as bubbles form and disappear.

Further, air bubbles formed within the fluid chamber due to separation of air component present in the fluid can also undergo compression during vibration input, leading to insufficient increase in the interior pressure of the fluid chamber.

As a result, there is likelihood that the mounted-type fluid-filled vibration-damping device fails to provide a desired level of damping performance during vibration input.

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