Auxiliary-Piston Vibration Damper for Frequency-Sensitive Damping
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Solution Overview
Problem
Existing vibration dampers with frequency-sensitive damping systems exhibit sluggish damping force adjustment in low speed ranges, failing to provide adequate frequency-dependent damping at low excitation speeds.
Innovation Solution
A vibration damper design featuring a working piston with a main piston and at least one auxiliary piston, equipped with an auxiliary valve device and a preloading system comprising pressure chambers with variable volumes, allowing for frequency-sensitive preloading and damping force adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a frequency-sensitive damping system is implemented in a vibration damper, then frequency-dependent damping can be achieved at high speeds, but the damping force adjustment becomes sluggish in low speed ranges
Solution Approach 1:
The damping system is segmented into multiple independent valve devices (first auxiliary valve device, second auxiliary valve device, third auxiliary valve device) each handling different frequency ranges. This segmentation allows each valve to be optimized for its specific frequency range, preventing the sluggish response that occurs when a single valve tries to handle all frequencies.
Solution Approach 2:
Each auxiliary valve device is designed with specific local characteristics - different spring stiffnesses, different flow channel geometries, and different preloading forces - to optimize performance for specific frequency ranges. The first auxiliary valve device handles low frequencies with higher damping, while the second and third handle higher frequencies with progressively lower damping characteristics.
2Stability of the object's composition
If high damping force is applied to achieve stability during cornering or braking, then vehicle stability improves, but ride comfort deteriorates due to excessive damping on high frequency vibrations
Solution Approach 1:
The valve system is divided into multiple auxiliary valve devices that segment the damping function across different frequency ranges. The first auxiliary valve device provides high damping for low-frequency body movements (cornering, braking) while the second and third auxiliary valve devices provide progressively lower damping for high-frequency road irregularities, allowing simultaneous optimization of stability and comfort.
Solution Approach 2:
The system dynamically changes damping parameters based on excitation frequency. At low frequencies (cornering, braking), the first auxiliary valve device maintains high damping force for stability. At high frequencies (road bumps), the second and third auxiliary valve devices reduce damping force to allow smoother ride, effectively adapting damping characteristics to the specific driving condition.
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 vibration damper achieves high damping at low frequencies, such as during cornering or braking, while reducing damping at high frequencies, thereby enhancing ride comfort and stability across varying driving conditions.
Implementation Method 1
as a function of the hydraulic pressure prevailing in the respective pressure chamber
Implementation Method 2
the first and/or the second pressure chamber are/is arranged in such a way that they/it subject/subjects the auxiliary valve piston to an axial force
Implementation Method 3
Vibration damper for a motor vehicle having a frequency-sensitive damping system
Data Source
AI summary
A vibration damper for a motor vehicle comprises a damper tube and a working piston, which is arranged in such a way as to be axially movable within the damper tube and divides the interior of the damper tube into a working space on the piston-rod side and a working space on the side remote from the piston rod, wherein the working piston has a main piston and at least one auxiliary piston, wherein the auxiliary piston has an auxiliary valve device, which is connected fluidically to a working space of the damper tube via a flow channel, wherein the auxiliary valve device comprises: an auxiliary valve body and an auxiliary valve piston, which is movable axially relative to the latter, and an auxiliary valve disc stack, which interacts with the auxiliary valve piston, wherein the auxiliary valve device has a preloading system for subjecting the auxiliary valve disc stack to a preloading force, and wherein the preloading system comprises a first pressure chamber and a second pressure chamber, which each have a variable volume.