Pilot-Controlled Shock Absorber Valve for Stable Low-Noise Damping
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Solution Overview
Problem
Existing damping valve devices for motor vehicle shock absorbers suffer from unstable behavior during dynamic operation, create acoustic issues during switching, and occupy excessive installation space, while being costly.
Innovation Solution
A damping valve device with a main valve and pilot valve design featuring a main piston with a U or W-shaped longitudinal section, a pilot-controlled pressure control valve, and a connecting duct between the pilot control chamber and working chamber, ensuring stable damping behavior and reduced size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a conventional damping valve device is used, then the shock absorber provides basic damping function, but the device occupies large installation space and creates acoustic noise during switching
Solution Approach 1:
The pilot valve is integrated within the main valve assembly, with the pilot valve body positioned inside the main valve housing. The pilot valve rod moves within the main valve chamber, and the pilot valve seat is formed as part of the main valve structure. This nested configuration allows the pilot valve to occupy space within the existing main valve envelope, significantly reducing the overall volume of the damping valve device while maintaining both valve functions.
Solution Approach 2:
The patent combines the main valve and pilot valve into a single integrated damping valve device. The main piston and pilot valve rod are connected through a shared rod structure, and both valves operate within a common hydraulic chamber system. The control chambers of both valves are interconnected through internal passages, merging the control functions into a unified system that reduces component count and installation space while coordinating the opening/closing actions to minimize acoustic noise.
2Reliability
If a conventional damping valve device is used, then the basic damping function is provided, but the device exhibits unstable behavior during dynamic operation
Solution Approach 1:
The pilot valve is hydraulically connected to the main valve through internal passages that create a feedback mechanism. When the main valve opens or closes, pressure changes in the main valve chamber are transmitted to the pilot valve control chamber, causing the pilot valve to modulate and stabilize the pressure differential across the main valve. This feedback loop prevents abrupt pressure changes and unstable behavior during dynamic operation, ensuring smooth damping transitions.
Solution Approach 2:
The pilot valve acts as an intermediary between the hydraulic system and the main valve. Instead of directly controlling the main valve with complex mechanical linkages, the patent uses the pilot valve to modulate hydraulic pressure that then acts on the main valve. This intermediary hydraulic control mechanism simplifies the overall structure while improving stability, as the pilot valve can precisely regulate pressure changes without requiring complex mechanical feedback linkages.
3Volume of moving object
If a compact damping valve device is designed, then installation space is reduced, but manufacturing complexity and cost may increase
Solution Approach 1:
The patent merges the main valve and pilot valve into a single integrated assembly that can be manufactured as one piece or pre-assembled unit. The main valve housing incorporates the pilot valve chamber, and internal passages are formed as integral features of the housing rather than requiring separate machining operations. The shared rod structure connecting the main piston and pilot valve rod can be manufactured as a single component, reducing part count and assembly complexity despite the compact design.
Solution Approach 2:
The main valve housing serves multiple functions: it contains the main valve mechanism, provides the pilot valve chamber, forms internal hydraulic passages, and structures the mounting interfaces. The shared rod structure simultaneously serves as the main valve rod and the pilot valve actuator. This multi-functionality reduces the number of separate components that would need to be manufactured and assembled, making the compact design economically viable despite the complex internal geometry.
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 provides a compact, cost-effective damping valve device with stable performance in both compression and traction phases, minimizing tilting and twisting of the main piston, and reducing acoustic noise.
Implementation Method 1
The damping valve device has a coil and an axially movable armature which is at least partially disposed within the coil
Implementation Method 2
The damping valve device has a coil and an axially movable armature which is at least partially disposed within the coil
Implementation Method 3
The vibration damper also comprises a damping valve device which is disposed in the working piston, wherein the damping valve device has a main valve and a pilot valve
Data Source
AI summary
A vibration damper of a motor vehicle comprises an outer tube and an inner tube which is disposed so as to be coaxial with the latter, and a working piston which is disposed so as to be axially movable within the inner tube and divides the interior of the inner tube into a piston rod-proximal working chamber and a piston rod-distal working chamber, a damping valve device which is disposed in the working piston, wherein the damping valve device has: a coil, an axially movable armature which is at least partially disposed within the coil, a main valve having a main piston which separates a compression main control chamber, a traction main control chamber and a pilot control chamber from one another, a pilot valve which is designed in such a manner that it is able to be passed through by a flow of hydraulic fluid in the traction phase and in the compression phase and has a pilot working chamber and a sliding tappet that is disposed in the pilot working chamber and is axially movable by means of the armature, and a connecting duct which is disposed between the pilot control chamber and the pilot working chamber and fluidically connects those to one another, wherein the main piston comprises a cylinder base region and a cylinder casing region which forms the radially outer face of the main piston.