Pilot Valve Damping Control for Asymmetric Shock Absorber Forces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing damping valve devices for vibration dampers have insufficient damping force ratios between pull and push directions, limiting their effectiveness in certain applications.
Innovation Solution
A pilot stage valve with separate pressurized surfaces for each working direction, hydraulically separated control chambers, and adjustable chokes to influence damping force characteristics, allowing for asymmetric damping forces and enhanced control over the damping behavior.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a pilot stage valve with common pressurized surfaces is used for both working directions, then the device complexity is reduced, but the damping force ratio between pull and push directions is insufficient
Solution Approach 1:
The control system is segmented into two hydraulically separated control chambers (first control chamber and second control chamber), each independently controlling one pressurized surface of the pilot stage valve. This segmentation allows independent adjustment of damping forces for pull and push directions, resolving the contradiction between structural simplicity and damping force ratio performance.
Solution Approach 2:
The patent introduces asymmetric design by providing different pressurized surfaces (first pressurized surface and second pressurized surface) with different areas on the pilot stage valve, and controlling them through separate control chambers. This asymmetry enables different damping force characteristics for incident flow from different working chambers, achieving the required damping force ratio while maintaining reasonable structural complexity.
2Adaptability or versatility
If separate control chambers with different pressure levels are implemented, then the damping force characteristics are optimized, but the device complexity increases
Solution Approach 1:
The patent implements dynamic adjustability by providing adjustable chokes (first choke and second choke) in the flow connections from working chambers to control chambers. These chokes can be adjusted to change the pressure levels in the control chambers dynamically, enabling flexible damping force characteristics adaptation without requiring complex mechanical switching mechanisms.
Solution Approach 2:
The patent uses hydraulic separation to create two independently controllable control chambers with different pressure levels. By utilizing hydraulic principles and fluid pressure control through adjustable chokes, the system achieves versatile damping force adjustment capability while avoiding more complex mechanical or electronic control systems.
3Force
If multiple chokes are used in series for flow connections, then the damping force ratio is increased, but the manufacturing precision requirements increase
Solution Approach 1:
The patent provides adjustable chokes that can be modified to change flow resistance parameters. By making the chokes adjustable rather than fixed, the system can achieve the required damping force asymmetry while compensating for manufacturing tolerances and reducing the stringency of manufacturing precision requirements for choke positioning and dimensions.
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 significantly increased damping force ratios and improved operational flexibility by optimizing the damping force characteristics based on flow direction, enhancing the performance of the damping valve device.
Implementation Method 1
A pilot stage valve body (43) of the pilot stage valve (7) has a first pressurized surface (D1) for an incident flow from the first working chamber (13) and a second pressurized surface (D2) for an incident flow from the second working chamber (15)
Implementation Method 2
The use of different pressurized surfaces at the pilot stage valve ensures a basic asymmetry of the damping forces which can easily be determined by the surface area ratio of the two pressurized surfaces
Implementation Method 3
The damping valve device has a total of four check valves that provide for the rectification of a volume flow proceeding from the working chamber on the piston rod side and from the working chamber remote of the piston rod to the pilot stage valve
Implementation Method 4
The two working chambers have a separate flow connection with at least one choke to the connected control chamber. The two choke points preferably have a different degree of restriction. The lower the degree of restriction, the greater the pressure in the control chamber of the pilot stage valve
Data Source
AI summary
An adjustable damping valve device for a vibration damper includes a pilot stage valve for hydraulic control of a main stage valve. The damping valve device has a check valve arrangement for the rectification of a control volume flow proceeding from working chambers of vibration damper to the pilot stage valve and is characterized in that a pilot stage valve body of the pilot stage valve has a first pressurized surface Di for an incident flow from a first working chamber and a second pressurized surface D2 for an incident flow from second working chamber.