Passive Valve for Damping-Adjustable Shock Absorber
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current damping-adjustable shock-absorbers with active valves produce pressure-flow rate characteristic curves with a second section that is ascending, rather than the desired constant or descending section, which affects the ideal operation of the shock-absorber.
Innovation Solution
A flow-control passive valve is introduced, comprising a valve body with a main and secondary space, a movable member, and metering discs, which allows for independent adjustment of the gradient and pressure values by varying the restrictor areas and spring preload, enabling a pressure-flow rate characteristic curve with a first ascending section followed by a constant or descending second section.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a flow-control active valve (solenoid valve) is used to control damping fluid flow, then the shock-absorber can adjust damping characteristics electronically, but the pressure-flow rate characteristic curve produces an ascending second section instead of the desired constant or descending section
Solution Approach 1:
The valve system is segmented into two distinct components: an active solenoid valve for electronic control and a passive flow-control valve with metering discs for precise flow regulation. This segmentation allows each component to perform its specialized function, with the passive valve's metering discs creating the desired constant or descending pressure-flow rate characteristic curve while the active valve provides electronic adjustability.
Solution Approach 2:
The passive flow-control valve acts as an intermediary between the active solenoid valve and the damping fluid. It mediates the flow control function by using metering discs with specific restrictor areas to shape the pressure-flow rate characteristic curve, translating the electronic control signal into the desired mechanical damping response with constant or descending second section characteristics.
2Manufacturing precision
If the flow control solenoid valve is operated with suitable driving logics to approximate the ideal pressure-flow rate characteristic curve, then the second section has a lower gradient, but it remains ascending instead of being constant
Solution Approach 1:
The passive flow-control valve with metering discs provides self-regulating flow control based on pressure differential. The metering discs automatically create the constant or descending pressure-flow rate characteristic curve through their geometric restrictor areas, eliminating the need for complex driving logics to achieve the desired curve shape. The system self-adjusts the flow characteristics passively.
Solution Approach 2:
The metering discs are designed with specific restrictor areas that directly determine the flow characteristics. By changing the geometric parameters of the restrictors in the metering discs, the pressure-flow rate characteristic curve is transformed from an ascending second section to a constant or descending second section, achieving the ideal curve shape through parameter design rather than control logic.
3Manufacturing precision
If metering discs with restrictors are introduced to control flow, then the gradient and pressure values can be independently adjusted, but the device complexity increases
Solution Approach 1:
The passive flow-control valve with metering discs serves multiple functions simultaneously: it regulates flow rate, shapes the pressure-flow rate characteristic curve, and enables independent adjustment of gradient and pressure values. This multi-functionality is achieved within a compact valve body, reducing the need for additional separate components and minimizing overall device complexity.
Solution Approach 2:
The metering discs are nested within the valve body, with multiple discs stacked axially between the valve body and movable member. This nested arrangement allows multiple restrictor areas to be integrated in a compact space, enabling independent adjustment of multiple parameters without proportionally increasing the overall device size or complexity.
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 passive valve achieves a pressure-flow rate characteristic curve with a second section that is either constant or descending, improving the operational efficiency of the shock-absorber by allowing for independent adjustment of key parameters, enhancing the damping characteristics.
Implementation Method 1
a spring (54) acting on the movable member (48) to maintain the passive valve (32) in a closed position
Implementation Method 2
whereby the pressure p1 in the main space is lower than the pressure pH in the upstream space due to a pressure drop through the first restrictor
Data Source
AI summary
In a damping-adjustable shock-absorber (10) comprising a pressure tube (12), an outer tube (20), an intermediate tube (22) and a flow-control active valve (28) for controlling the flow of a damping fluid to/from the intermediate tube (22), a flow-control passive valve (32) is interposed between the intermediate tube (22) and the active valve (28). The passive valve (32) comprises a valve body (34, 36) in fluid communication on the one side (64) with the intermediate tube (22) and on the other side (82) with the active valve (28), a movable member (48) slidable in a chamber (46) of the valve body (34, 36), a spring (54) acting on the movable member (48), and metering means (56, 64, 68, 72, 76) for metering the flow of the fluid from the intermediate tube (22) to the active valve (28) through the valve body (34, 36). The metering means (56, 64, 68, 72, 76) are configured in such a manner as to al¬ low to obtain a pressure-flow rate characteristic curve with a first ascending section and a second constant, or even descending, section.