Damper Piston Bleed Valve for Tunable Low-Speed Damping
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Solution Overview
Problem
Existing damper valves in vehicle suspensions have limited tunability in the low speed range, leading to inadequate handling and ride comfort, and require improvements in reliability, manufacturability, and cost.
Innovation Solution
A damper assembly with a piston featuring a pressure-sensitive bleed valve that includes a working disc stack deflectable in two opposite directions to regulate fluid flow, providing tunable damping characteristics from near-zero speed and improving manufacturing ease.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If simple flow characteristics of oil through a constant orifice are used, then the damping force increases progressively as velocity increases, but the damping force is close to zero in the ultra-low speed range and the flow characteristic cannot be tuned
Solution Approach 1:
The bleed valve incorporates a movable disc that dynamically adjusts the effective orifice area based on operating conditions. The disc can shift positions to change the flow characteristics, enabling tunable damping across different velocity ranges without requiring multiple fixed orifice configurations.
Solution Approach 2:
The invention changes the flow parameters by using a variable orifice area instead of a constant orifice. The effective area is modified through the position of the disc, which responds to pressure differential changes, thereby adjusting the damping characteristics across different operating regimes.
2Adaptability or versatility
If more complex damper valve designs are used to provide tunable characteristics over low speed ranges, then the damping characteristics become tunable, but the manufacturing difficulty and cost increase
Solution Approach 1:
The invention extracts the tuning function from a complex multi-component valve system and concentrates it in a single movable disc element. This simplification maintains the tunability capability while significantly reducing manufacturing complexity and cost compared to traditional multi-valve designs.
Solution Approach 2:
The single disc element performs multiple functions: it acts as a flow regulator, a pressure-sensing element, and a tuning mechanism simultaneously. This multi-functionality eliminates the need for separate components for each function, thereby simplifying manufacturing while achieving tunable damping characteristics.
3Speed
If pre-tensioned relief valves are used to open at given pressure levels, then the oil flow becomes less suppressed in high speed range, but the damping characteristics are limited to two zones only
Solution Approach 1:
Instead of fixed pressure-level relief valves that create discrete two-zone characteristics, the invention uses a dynamically responsive disc that continuously adjusts the orifice area based on instantaneous pressure differential. This creates a smooth, continuous transition across the entire operating speed range rather than abrupt zone transitions.
Solution Approach 2:
The disc responds periodically to pressure differential changes, automatically adjusting the flow area as operating conditions vary. This periodic response enables the system to adapt to different speed ranges continuously, providing appropriate damping characteristics across the full operating envelope without fixed zone limitations.
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 pressure-sensitive bleed valve offers appropriate damping from near-zero damper speed with a more linear increase in force, enhancing handling and ride comfort while being easy to manufacture.
Implementation Method 1
the working disc is deflectable in two opposite directions along the center axis in response to a pressure differential for regulating flow of the working fluid
Implementation Method 2
Shock absorbers are generally designed to provide a desired level of damping forces in a vehicle suspension
Data Source
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AI summary
A damper assembly and a piston therefor. The piston includes a pressure-sensitive bleed valve which includes at least one working disc and an outer disc that is disposed radially outside of the at least one working disc. The at least one working disc is abutted against the outer disc in a radial direction, and is deflectable in two opposite directions along the center axis for regulating flow of the working fluid through the piston during the compression stroke and the rebound stroke.