Frequency-Sensitive Shock Absorber Pilot Valve for Ride-Stability Balance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional shock absorbers face challenges in simultaneously achieving ride comfort and steering stability due to their inability to effectively adjust damping force according to varying road surface conditions and frequencies, leading to inconsistent performance across different driving speeds and frequencies.
Innovation Solution
A vibration control device and frequency-sensitive shock absorber are designed with a pilot valve unit that includes a free piston, which adjusts pressure based on fluid flow during low and high-frequency tension strokes, allowing for balanced pressure between chambers to optimize damping force generation and reduction accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single flow path is used with a constant damping characteristic, then the device structure is simple, but the damping force cannot be adjusted for different frequencies, affecting both ride comfort and steering stability
Solution Approach 1:
The valve structure is segmented into multiple independent flow paths: a first flow path for high-frequency vibrations and a second flow path for low-frequency vibrations. Each flow path has its own damping characteristics controlled by separate valve elements, allowing independent adjustment of damping force for different frequency ranges without increasing overall structural complexity
Solution Approach 2:
The valve structure transitions from a static, constant damping design to a dynamic, frequency-sensitive design. The valve elements respond dynamically to vibration frequency, automatically adjusting the damping force applied to each flow path based on the operating conditions, thereby achieving adaptability without requiring complex external control systems
2Adaptability or versatility
If the damping force is lowered for low-speed operation, then ride comfort is improved, but steering stability is compromised
Solution Approach 1:
The damping control function is segmented by frequency range. The first flow path handles high-frequency steering inputs with higher damping to maintain stability, while the second flow path handles low-frequency body movements with lower damping to improve comfort. This segmentation allows both competing requirements to be satisfied simultaneously through frequency-based separation
Solution Approach 2:
The valve structure acts as an intermediary that selectively applies different damping characteristics to different frequency components of the vibration signal. By mediating between the conflicting requirements of ride comfort and steering stability through frequency-based flow path selection, the system achieves both goals without direct compromise
3Adaptability or versatility
If the damping force changes according to piston speed, then the shock absorber responds to various road conditions, but it cannot distinguish between different vibration frequencies
Solution Approach 1:
The valve structure is segmented into frequency-specific flow paths with distinct valve elements. The first flow path is optimized for high-frequency response while the second flow path is optimized for low-frequency response. This segmentation enables frequency discrimination without requiring complex sensors or control systems, as the physical structure itself separates the frequency responses
Solution Approach 2:
Different parts of the valve structure are designed with locally optimized characteristics for specific frequency ranges. The first flow path contains valve elements with geometry and material properties suited for high-frequency damping, while the second flow path contains elements optimized for low-frequency damping. This local quality differentiation enables frequency-specific control within a unified valve structure
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 improves ride comfort by maintaining pressure balance during low-frequency strokes and reducing damping force during high-frequency strokes, thereby enhancing both ride comfort and steering stability across different driving conditions.
Implementation Method 1
a free piston provided to reciprocate in a vertical direction according to a change in the pressure formed by the fluid
Implementation Method 2
pressure is formed by a fluid introduced through the sub-piston rod
Implementation Method 3
a pilot valve located between the first pilot valve body and the second pilot valve body and elastically deformed according to a pressure change formed by the fluid in the first pilot valve body and the second pilot valve body
Implementation Method 4
a shock absorber is installed in a moving means such as a car to absorb and buffer vibrations or shocks received from a road surface during driving
Data Source
AI summary
The present disclosure relates to a vibration control device and a frequency-sensitive shock absorber having the same. A vibration control device includes a sub-piston rod coupled to an end of a piston rod, a pilot valve unit penetrated by and coupled to the sub-piston rod, in which pressure is formed by a fluid introduced through the sub-piston rod, and a fixing member located in a lower portion of the pilot valve unit and fastened to the sub-piston rod to fix the pilot valve unit, wherein the pilot valve unit comprises a free-piston provided to reciprocate in a vertical direction according to a change in the pressure formed by the fluid.