Shock Absorber Check Valve Assembly for Vibration-Stable Flow
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Solution Overview
Problem
Conventional check valves in shock absorbers face issues with stability during high-frequency vibrations and small rapid accelerations, often resulting in unwanted pressure spikes and failure to return to the closed position due to low fluid pressure, leading to compromised functionality.
Innovation Solution
A check valve assembly with a spool that moves between two positions, utilizing a first biasing means to open and a second biasing means to close the fluid passage, featuring a design with multiple regions of engagement to control fluid flow and pressure, allowing for better absorption of rapid accelerations and vibrations by varying the volume under pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a relatively high lifting height is required to allow for high flows of fluid, then the valve can handle high fluid flow, but the shim or poppet is detained at the open position due to low fluid pressure forces, causing the check valve to lose its function
Solution Approach 1:
A second spring is introduced as an intermediary element to assist the first spring in returning the spool to the closed position. This second spring provides additional restoring force when fluid pressure is insufficient, ensuring the valve reliably closes even during high flow conditions where pressure forces are low.
Solution Approach 2:
The system changes the stiffness characteristics of the biasing mechanism by using two springs with different stiffness values. The first spring has lower stiffness for normal operation, while the second spring has higher stiffness to provide additional closing force when needed, effectively adapting the restoring force parameter to match operating conditions.
2Quantity of substance
If the moving part is positioned at a large distance from the seat, then high fluid flow is allowed, but the moving part sticks to the stationary part, causing unwanted pressure spikes
Solution Approach 1:
The second spring acts as an intermediary force that continuously pushes the spool toward the closed position, preventing the moving part from sticking to the stationary part. This ensures consistent separation and eliminates the conditions that lead to pressure spikes during high flow operations.
3Device complexity
If a single spring is used to bias the spool, then the device complexity is low, but the valve cannot handle high-frequency vibrations and small rapid accelerations effectively
Solution Approach 1:
The biasing mechanism is segmented into two separate springs with different functions: the first spring handles normal operating conditions, while the second spring specifically addresses high-frequency vibrations and rapid accelerations. This segmentation allows each spring to be optimized for its specific role, improving overall vibration handling capability.
Solution Approach 2:
The dual-spring system creates a dynamic biasing force that adapts to different operating conditions. During normal operation, the first spring provides the primary biasing force, while during high-frequency vibrations and rapid accelerations, the second spring becomes more active, providing additional restoring force to maintain valve functionality.
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 check valve assembly provides a stable and reliable performance by reducing sensitivity to frequency and flow variations, effectively handling high-frequency vibrations and rapid accelerations without pressure spikes, ensuring consistent operation.
Implementation Method 1
a first biasing means configured to bias the spool towards the second position through at least first operational range of the spool in which first operational range the fluid passage is open
Implementation Method 2
a second biasing means configured to bias the spool towards the first position partly through a second operational range of the spool in which second operational range the fluid passage is closed
Data Source
Figure 1a~1b
Figure 2a~2b
Figure 3a~3b
AI summary
Check valve assembly (1, 1') for a shock absorber (100) comprising a housing (10), said housing (10) comprising a first volume (11), wherein a first pressure (P1) prevails; a second volume (12), wherein a second pressure (P2) prevails; a fluid passage (20) between said first (11) volume and said second (12) volume; and a spool (40) movably arranged in said housing (10) for movement back and forth between an first position, in which a flow of fluid through said fluid passage (20) is allowed, and a second position, in which the spool (40) closes the fluid passage (20). The check valve assembly further comprises a first biasing means (50) configured to bias the spool (40) towards the second position through at least first operational range (OR1) of the spool (40) in which first operational range the fluid passage (20) is open. Also, the check valve assembly comprises a second biasing means (51) configured to bias the spool (40) towards the first position partly through a second operational range (OR2) of the spool (40) in which second operational range (OR2) the fluid passage (20) is closed. The first biasing means forces the spool from its open position at least to its closed position for closing the passage.