Shock Absorber 2-Way Valve Soft Opening
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Solution Overview
Problem
Traditional valve arrangements in shock absorbers exhibit sharp damping characteristics due to sudden increases in damping medium flow, leading to instabilities such as initial overshot and oscillations, and fail to provide desired damping in 2-way valves.
Innovation Solution
A 2-way valve arrangement with different restricting interfaces during compression and rebound strokes, utilizing serially arranged radial restrictions to control fluid flow, allowing for adjustable area ratios between compression and rebound pressure areas without altering the pilot pressure, ensuring smooth damping characteristics in both directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional pressure regulator with a movable valve member is used to control damping medium flow, then pressure control is achieved through force equilibrium, but the valve opens sharply when threshold pressure is reached causing instability and oscillations
Solution Approach 1:
The valve member is segmented into a fixed seat portion and a movable cap portion, creating multiple flow passages (first, second, and third flow passages) with different restriction characteristics. This segmentation allows the valve to provide progressive flow control rather than a single sharp opening, eliminating oscillations while maintaining reliable pressure control.
2Adaptability or versatility
If a 1-way soft opening valve construction is used, then desired damping characteristics are achieved in one flow direction, but the opposite direction damping is not desirable
Solution Approach 1:
Different flow passages are designed with different restriction characteristics tailored to specific flow directions. The first flow passage provides soft opening for compression stroke, while the second and third flow passages provide appropriate restriction for rebound stroke. This local quality differentiation enables the valve to deliver optimal damping characteristics in both directions simultaneously.
3Productivity
If the valve member is forced open by pressure and flow force exceeding opposing forces, then flow passage opens, but the opening is distinct and sharp rather than smooth
Solution Approach 1:
The valve system transitions from a static single-threshold opening to a dynamic multi-stage opening process. As pressure builds, the valve progressively opens through multiple flow passages with different restriction levels, creating a smooth, continuous damping characteristic that adapts to changing pressure conditions rather than a abrupt single opening event.
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 achieves improved damping characteristics by enabling soft opening in both compression and rebound strokes, enhancing the smoothness of damping and allowing for independent adjustment of compression and rebound pressure areas, thus reducing instability and achieving desired damping forces in both directions.
Implementation Method 1
a pilot pressure is defined by a hydraulic pressure in the pilot chamber
Implementation Method 2
the main fluid flow is restricted at a first restriction and a cooperating serially arranged second restriction
Data Source
Figure 1a
Figure 1b
Figure 2a
AI summary
Valve arrangement for a shock absorber is described, comprising a valve housing (2) having a first (7) and a second port (8), a pilot chamber (3) being in fluid communication with the first (7) and/or second port (8), wherein a pilot pressure (Pp) is defined by a hydraulic pressure in the pilot chamber (3). The arrangement further comprises a main valve member (4) being axially movably arranged in the valve housing (2) and being arranged to interact with a main valve seat member (9) in order to restrict a main fluid flow between the first (7) and second ports (8) in response to the pilot pressure (Pp) acting on the main valve member (4). Moreover, the main valve seat member (9) is movable between a first compression stroke position and a second rebound stroke position so that, during the compression stroke, the main fluid flow is restricted at a first restriction (R1) and a cooperating serially arranged second restriction (R2), and during the rebound stroke, the main fluid flow is restricted at a third restriction (R3) and a cooperating serially arranged fourth restriction (R4).