Two-Stage Valve Assembly for Shock Absorber NVH Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current shock absorbers with valve assemblies face limitations in controlling damping forces effectively across different strokes, leading to suboptimal Noise, Vibration, and Harshness (NVH) performance due to the sudden opening of sliding valve designs and performance limitations at increasing pressure drops in clamped valve designs.
Innovation Solution
The implementation of two-stage valve assemblies that combine the performance characteristics of sliding and clamped valve designs, incorporating hydraulic damping to control the opening of the valve assembly, allowing for gradual opening and improved NVH performance across varying velocities and pressure drops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a sliding valve design is used, then the valve opens quickly allowing high flow rates, but it causes sudden opening leading to poor NVH performance
Solution Approach 1:
The valve assembly is divided into two distinct stages: a clamped valve disc for initial gradual opening and a sliding valve disc for subsequent high-flow operation. This segmentation allows each stage to perform its specialized function, resolving the contradiction between quick opening and smooth NVH performance.
Solution Approach 2:
The clamped valve disc performs preliminary action by gradually opening first to control the initial flow and minimize NVH issues. Only after this preliminary controlled opening does the sliding valve disc engage to provide high-flow capability, thus preparing the system in advance to avoid sudden opening problems.
2Object-affected harmful factors
If a clamped valve design is used, then the valve opens gradually improving NVH performance, but it has performance limitations at increasing pressure drops
Solution Approach 1:
The valve assembly dynamically transitions from a static clamped configuration to a dynamic sliding configuration. As pressure increases, the system automatically shifts from the gradual-opening clamped stage to the high-pressure-capable sliding stage, adapting to varying operating conditions to maintain optimal performance across the full pressure range.
Solution Approach 2:
The first sliding valve disc acts as an intermediary element that transfers the load and flow control function from the clamped valve disc at low pressures to the second sliding valve disc at high pressures. This intermediary mechanism enables smooth transition and combines the advantages of both clamped and sliding valve designs.
3Force
If compression valving and rebound valving are implemented to limit fluid flow, then damping force is produced, but the valve assembly complexity increases
Solution Approach 1:
The two-stage valve assembly with hydraulic damping performs multiple functions simultaneously: it provides both compression valving and rebound valving capabilities while maintaining a relatively compact structure. The shared hydraulic damping mechanism serves both compression and rebound strokes, reducing the need for separate complex valve systems for each function.
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 solution enhances the damping control and NVH performance by utilizing the gradual opening of clamped valves at initial stages and the performance characteristics of sliding valves at higher velocities, effectively addressing the limitations of existing designs.
Implementation Method 1
The two stage valve of the present disclosure can incorporate hydraulic damping which controls the opening of the valve assembly
Implementation Method 2
By controlling the oil flow between the two chambers, a pressure drop is build up between the two chambers and this contributes to the damping forces of the shock absorber
Data Source
AI summary
A shock absorber includes a two stage valve assembly that has two valve discs. The second valve disc defines the first stage at lower valve pressures and the first valve disc defines the second stage at higher valve pressures. The two valve discs can be defined by a single piece component or they can be separate components. The second valve disc can permit fluid flow by deflection of the second valve disc or by movement of the entire second valve disc. The two stage valve assembly can be incorporated into the piston assembly of the shock absorber and/or the two stage valve assembly can be incorporated into a base valve assembly.