Variable Damping Valve Assembly for Rebound Lag Control
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Solution Overview
Problem
Conventional internal type damping force variable valve assemblies experience rapid changes in compression stroke pressure when the flow rate increases, leading to rebound lag phenomenon in hard mode, especially at high speeds, due to insufficient fluid flow to the extension chamber during compression strokes.
Innovation Solution
The damping force variable valve assembly incorporates a main flow path, a first auxiliary flow path for soft mode, and a second auxiliary flow path for compression pressure adjustment in hard mode, with a check valve unit that selectively opens the second auxiliary flow path to prevent large pressure changes during compression strokes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the flow rate increases during compression stroke, then the damping force increases, but the compression stroke pressure changes rapidly causing rebound lag phenomenon
Solution Approach 1:
The patent divides the single flow path into multiple flow paths (first flow path, second flow path, and third flow path) with different characteristics. The second flow path is specifically designed as a bypass for compression stroke, allowing fluid to flow through alternative routes when compression pressure increases, thereby preventing rapid pressure changes and rebound lag while maintaining damping force.
Solution Approach 2:
The patent introduces a compression stroke bypass hole as an intermediary flow path that activates under specific compression conditions. This bypass hole provides an additional fluid communication route between compression and extension chambers when compression pressure rises, mediating the pressure changes and preventing rebound lag phenomenon.
2Reliability
If the valve body rigidity is increased to improve rebound lag phenomenon, then the rebound lag is reduced, but the tuning range of the valve is reduced
Solution Approach 1:
The patent implements dynamic flow path switching through multiple valves (first valve, second valve, third valve) that can independently control different flow paths. This dynamic configuration allows the system to adapt between different damping characteristics (soft mode, hard mode, and intermediate modes) without requiring a rigid valve body, thereby maintaining both reliability and tuning range.
Solution Approach 2:
The patent enables continuous adjustment of damping characteristics by varying the opening degrees of multiple valves and utilizing different flow path combinations. This parameter-based control approach provides a wide tuning range from soft to hard damping modes while preventing rebound lag through the compression stroke bypass mechanism, avoiding the need for increased valve body rigidity.
3Force
If the auxiliary flow path is opened for variable damping force, then low damping force is generated, but fluid flow to extension chamber becomes insufficient during compression stroke
Solution Approach 1:
The patent segments the fluid flow into multiple independent paths: the first flow path for primary damping control, the second flow path (compression bypass) for ensuring sufficient compression flow, and the third flow path for extension stroke control. This segmentation allows the auxiliary flow paths to provide variable damping while the compression bypass ensures adequate fluid supply to the extension chamber during compression strokes.
Solution Approach 2:
The compression stroke bypass hole acts as an intermediary that supplements fluid flow during compression strokes. When the auxiliary flow paths are opened for variable damping, the bypass hole provides an additional route that ensures sufficient fluid volume reaches the extension chamber, preventing flow insufficiency while maintaining the desired low damping force characteristics.
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
This configuration effectively adjusts damping force and prevents rebound lag by ensuring stable compression stroke pressure changes, even at increased flow rates, thereby improving the shock absorber's performance in both soft and hard modes.
Implementation Method 1
a solenoid disposed in the outer housing; and a damping force adjustment unit provided between the solenoid and the piston valve in the outer housing and actuated by the solenoid
Implementation Method 2
The damping force adjusting unit includes a check valve unit that selectively opens the second auxiliary flow path
Implementation Method 3
a main flow path through which fluid flows during compression and extension strokes, a first auxiliary flow path which allows fluid flow only in soft mode during the compression and extension strokes
Data Source
AI summary
In an outer housing and a damping force adjustment unit constituting a damping force variable valve assembly and a damping force variable shock absorber of the present disclosure, a main flow path through which fluid flows during compression and extension strokes, a first auxiliary flow path which allows fluid flow only in soft mode during the compression and extension strokes and is closed in hard mode, and a second auxiliary flow path which allows fluid flow for compression pressure adjustment only in the hard mode during the compression stroke are formed. The damping force adjusting unit includes a check valve unit that selectively opens the second auxiliary flow path.