Shock Absorber Valve Biasing for Low-Speed Damping Sealing
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Solution Overview
Problem
Existing shock absorbers face hydraulic fluid leakage issues between the sub-check valve and disc valve during low piston velocity strokes, leading to inadequate damping force generation.
Innovation Solution
A shock absorber design featuring a biasing disc of equal diameter to the sub-check valve, which biases the sub-check valve towards the orifice passages, preventing hydraulic fluid leakage and ensuring consistent damping force delivery by maintaining contact between the disc valve and sub-check valve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a sub-check valve is provided at passage openings of orifice passages in a disc valve, then damping force adjustment capability is improved, but hydraulic fluid leakage occurs between the sub-check valve and disc valve during low velocity strokes
Solution Approach 1:
A biasing member is introduced as an intermediary element between the sub-check valve and disc valve. This biasing member applies a biasing force to maintain contact between the sub-check valve and disc valve, preventing hydraulic fluid leakage while preserving the damping force adjustment capability of the sub-check valve.
Solution Approach 2:
The biasing member pre-applies a contact force between the sub-check valve and disc valve before hydraulic fluid pressure builds up. This preliminary action ensures that the sub-check valve remains sealed against the disc valve even during low velocity strokes when pressure differential is minimal, preventing leakage before it can occur.
2Adaptability or versatility
If the sub-check valve is allowed to open at lower pressure for damping control, then damping force variability is improved, but hydraulic fluid leaks through the gap between sub-check valve and disc valve
Solution Approach 1:
The biasing member generates a counteracting force that opposes the tendency of the sub-check valve to separate from the disc valve. This biasing force acts as a counterweight to the hydraulic pressure forces, maintaining contact between the valve components and preventing leakage while allowing the sub-check valve to open at lower pressures for damping control.
Solution Approach 2:
The biasing member serves as a mediator that reconciles the conflicting requirements of low-pressure valve opening (for damping variability) and valve sealing (to prevent leakage). It enables the sub-check valve to open at lower pressures while simultaneously maintaining sufficient contact pressure to prevent hydraulic fluid leakage.
3Manufacturing precision
If the sub-check valve structure is added to the orifice passages, then damping control precision is improved, but device complexity increases
Solution Approach 1:
The biasing member is designed to perform multiple functions: it maintains contact between the sub-check valve and disc valve, prevents hydraulic fluid leakage, and enables the sub-check valve to open at appropriate pressures. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity while achieving precise damping control.
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 effectively restrains hydraulic fluid leakage, enhancing ride comfort by maintaining intended damping force even at low piston velocities and preventing delays in damping force generation during stroke reversals.
Implementation Method 1
The sub-check valve is provided with a biasing member of substantially equal diameter to the sub-check valve, the biasing member being configured to bias the sub-check valve toward the passage openings
Data Source
AI summary
The invention is directed to provide a shock absorber in which hydraulic fluid is restrained from leaking out from a gap between a sub-check valve provided at a passage opening of an orifice passage and a disc valve. The sub-check valve (133) is biased toward the opening (126) of the orifice passage (130) using a biasing disc (135) (biasing member) of substantially equal diameter to the sub-check valve (133). This makes it possible to restrain hydraulic fluid in a first chamber (2A) from leaking out from a gap between a disc valve (121) and the sub-check valve (133) into a second chamber (2B) when piston velocity during an extension stroke is low (0.1 m/s or lower, exclusive zero), and thus obtain an intended damping force.