Bypass Valve Shock Absorber for Low-Velocity Damping
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Solution Overview
Problem
Conventional shock absorbers fail to effectively dampen smaller, smooth road vibrations, leading to discomfort for vehicle occupants and impairing vehicle response to such vibrations, due to their higher low-velocity damping forces.
Innovation Solution
A dual-tube shock absorber design incorporating a pressure tube with a working chamber divided by a piston, a reservoir tube, and a bypass valve that utilizes internal pressure differential related to displacement, velocity, and acceleration for valve regulation to control damping, particularly for smooth road vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional shock absorbers use higher low-velocity damping forces, then vehicle handling and road holding ability are improved, but ride comfort deteriorates due to inability to dampen smooth road vibrations
Solution Approach 1:
The shock absorber employs a bypass valve that dynamically adjusts damping forces based on piston velocity. At low velocities (smooth road conditions), the bypass valve opens to reduce damping forces and improve ride comfort. At high velocities (rough road conditions), the bypass valve closes to increase damping forces and maintain road holding ability. This dynamic adjustment resolves the contradiction between ride comfort and road holding ability.
Solution Approach 2:
The invention changes the damping parameter based on operating conditions by using a bypass valve mechanism. The valve regulates fluid flow between the reservoir chamber and working chamber, effectively changing the damping force parameter from high (conventional) to variable (low at low velocity, high at high velocity). This parameter change allows the shock absorber to adapt to different road conditions and resolve the contradiction between comfort and handling.
2Reliability
If shock absorbers restrict fluid flow to increase damping forces, then vehicle handling is improved, but the ability to respond to smooth road vibrations is impaired
Solution Approach 1:
The bypass valve provides dynamic adaptability by automatically opening or closing based on piston velocity. This allows the shock absorber to adapt its damping characteristics to match road conditions, improving both vehicle handling on rough roads and responsiveness to smooth road vibrations through the same dynamic mechanism.
Solution Approach 2:
The bypass valve mechanism is self-regulating, using the piston's own velocity to control valve opening. At low velocities, the valve automatically opens to allow fluid bypass, enabling the shock absorber to self-adjust for smooth road conditions without external control systems.
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 solution reduces jounce and rebound forces at low velocities, improving ride comfort and vehicle responsiveness to smooth road conditions by optimizing damping forces based on piston speed and acceleration.
Implementation Method 1
a bypass valve that utilizes internal pressure differential related to a combination of displacement, velocity, and acceleration for valve regulation
Implementation Method 2
Conventional hydraulic shock absorbers are available in two styles: a single-tube shock absorber and a dual-tube shock absorber
Implementation Method 3
The shock absorber works on a principle of fluid displacement on both its compression and extension cycles
Data Source
AI summary
A dampening mechanism is described having a pressure tube defining a working chamber between a rod guide proximate a first end and an end cap proximate a second end. A piston is disposed within the pressure tube and divides the working chamber into an upper working chamber and a lower working chamber. A piston rod is secured to the piston. A reservoir tube surrounds the pressure tube defining a reservoir chamber between the reservoir tube and the pressure tube. At least one passage is disposed through the pressure tube between the reservoir chamber and the working chamber and a bypass valve is disposed between the piston and the at least one passage.