Fluid-filled Vibration Damping Device Buffer Body Noise Reduction
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Solution Overview
Problem
Fluid-filled vibration damping devices with liquid pressure transmission mechanisms tend to generate striking noise due to impact forces when a movable member contacts the inner surface of the housing space, leading to abnormal noise in the vehicular cabin.
Innovation Solution
A fluid-filled vibration damping device with a novel structure featuring a main rubber elastic body, a partition member, pressure-receiving and equilibrium chambers filled with non-compressible fluid, and a movable member housed in a housing space with communication holes and window portions in a buffer body, which maintains communication between the chambers at mid- to high-frequency vibrations and shuts off at tuning frequency vibrations to reduce noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a liquid pressure transmission mechanism with a movable member is built in the vibration damping device, then vibration damping performance is improved, but striking noise is generated due to impact force when the movable member contacts the housing space
Solution Approach 1:
A buffer body is introduced as an intermediary component between the movable member and the housing space. The buffer body includes a buffer portion that comes into contact with the movable member when it moves, providing cushioning and preventing direct impact between the movable member and the housing space, thereby reducing striking noise while maintaining vibration damping performance
Solution Approach 2:
The buffer body is pre-positioned in the housing space such that the buffer portion is ready to contact the movable member before any potential impact with the housing space occurs. This beforehand cushioning arrangement ensures that the movable member is cushioned during its movement, preventing direct contact with the housing space and eliminating striking noise
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device effectively reduces striking noise by attenuating impact energy through internal friction and elastic deformation of the buffer body, preventing noise transmission to the vehicular cabin while maintaining vibration damping performance.
Implementation Method 1
The movable member is housed in the inner space with the buffer body, which comes in contact with wall inner surfaces of the housing space... to reduce striking noise generated by impact energy
Implementation Method 2
The buffer body... with a pair of side plate portions connecting the pair of facing plate portions to each other... to attenuate impact energy through internal friction and elastic deformation
Implementation Method 3
a non-compressible fluid; an orifice passage through which the pressure-receiving chamber and the equilibrium chamber communicate with each other
Implementation Method 4
a main rubber elastic body elastically connecting the first and second mounting members
Implementation Method 5
the movable member undergoes a slight displacement or deformation at an input of high-frequency small-amplitude vibration to allow transmission of liquid pressure... while the movable member blocks the communication hole to prevent transmission of liquid pressure
Data Source
AI summary
A fluid-filled vibration damping device including a hollow buffer body with an inner space. The hollow buffer body is housed in a housing space of a partition member to come in contact with wall inner surfaces of the housing space on sides of a pressure-receiving chamber and an equilibrium chamber, while stores a movable member in the inner space thereof. Liquid pressure of the pressure-receiving chamber is applied to a first face of the movable member by having a first window portion formed in the buffer body communicated with a first communication hole of the housing space while liquid pressure of the equilibrium chamber is applied to a second face of the movable member by having a second window portion formed in the buffer body communicated with a second communication hole of the housing space.