Hydraulic Shock Absorber Progressive Valve Damping
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Solution Overview
Problem
Conventional shock absorbers for vehicles face challenges in balancing flexibility during compression to maintain ground contact and preventing bottoming out, which can lead to energy storage and rebound issues, affecting traction and comfort.
Innovation Solution
A hydraulic shock absorber design with an auxiliary tank and a distributor system that adjusts pressure drops and flow rates to increase damping at the end of the compression stroke, reducing the stiffness of the spring and hydraulic compression brake, thereby delaying or eliminating bottoming and minimizing the racket kick effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the stiffness of the spring element is increased to delay bottoming out, then bottoming is delayed, but grip and comfort deteriorate due to reduced flexibility at the beginning of compression
Solution Approach 1:
The shock absorber employs dynamic adjustment of damping characteristics through a progressive valve system that modifies hydraulic resistance based on piston velocity and position. The valve opens progressively during compression stroke, providing high damping at low velocities (preventing bottoming) while maintaining flexibility at high velocities (ground contact adaptation), thus resolving the contradiction between preventing bottoming and maintaining adaptability
Solution Approach 2:
The invention changes the physical parameters of the hydraulic system by using a variable orifice valve that adjusts flow resistance dynamically. The valve geometry and spring preload are designed to create non-linear damping characteristics where the damping coefficient varies with compression stroke position and velocity, enabling the system to provide different stiffness levels at different phases of the stroke cycle
2Reliability
If hydraulic compression braking is increased to delay bottoming out, then bottoming is delayed, but comfort and grip worsen due to excessive damping throughout the stroke
Solution Approach 1:
The progressive valve system dynamically modulates hydraulic compression braking based on real-time piston velocity and position. At low velocities near the end of stroke, the valve provides high resistance to prevent bottoming. At high velocities during normal operation, the valve opens to reduce damping, maintaining comfort and grip. This dynamic control eliminates the need for uniformly high compression braking throughout the stroke
3Reliability
If end-of-travel springs or rubber stops are used to delay bottoming, then bottoming is delayed, but energy is stored and restored causing racket kick rebound
Solution Approach 1:
The invention converts the potentially harmful bottoming-out condition into a controlled hydraulic damping event. Instead of allowing hard mechanical contact with energy storage and rebound, the progressive valve system creates controlled hydraulic resistance that dissipates energy as heat through fluid friction. The valve geometry and oil viscosity are selected to provide progressive damping that increases as the piston approaches the end of stroke, converting what would be a harmful impact into a beneficial energy dissipation mechanism
Solution Approach 2:
The invention uses hydraulic damping through a closed-loop fluid system with a progressive valve to replace mechanical spring stops. The hydraulic system provides smooth, progressive resistance during compression stroke, and the fluid's compressibility and viscosity characteristics enable energy dissipation without the elastic rebound associated with mechanical springs. The hydraulic circuit includes check valves and orifices that control fluid flow to achieve damping without energy restoration
4Reliability
If the length of the protrusion and housing is increased to prevent bottoming over a reduced stroke, then bottoming is prevented, but the shock absorber size increases or stroke is limited
Solution Approach 1:
The progressive valve system prevents bottoming out over the full compression stroke without requiring additional end-of-travel components. The valve's progressive opening characteristic provides increasing damping resistance as the piston approaches the end of stroke, effectively preventing bottoming throughout the entire stroke range. This eliminates the need for extended protrusions or housing to create a reduced-stroke hydraulic stop, maintaining compact shock absorber 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
This design allows for improved damping over a significant part of the stroke, enhancing contact with the ground, reducing energy storage, and preventing vehicle rebound, thus improving traction and comfort by adapting to terrain profiles.
Implementation Method 1
a hydraulic brake valve (341, 342). A washer (341, 342) is mounted in the tank (301) and also has a hydraulic brake valve (341, 342)
Implementation Method 2
The piston (373) drives the washer (341, 342) from a certain position in its stroke in the tank (301)
Data Source
Figure 1~4
Figure 5~11
Figure 12~14
AI summary
The invention relates to a vehicle hydraulic shock absorber comprising: a reservoir (301) filled with hydraulic fluid; a piston (373) slidably mounted in the reservoir; a shaft (371) extending in the axial direction on a first side relative to the piston; a distributor (307) comprising: a primary orifice (324) opening into the reservoir on a second side of the piston, the primary orifice being in communication with a first fluid flow circuit; and a secondary orifice (325) opening into the reservoir on the second side of the piston and in communication with a second fluid flow circuit the pressure drop across which is greater than the pressure drop across the first flow circuit; a protrusion (380) separated from the primary orifice over a first part of the stroke of the piston and closing off the primary orifice over a second part of the stroke of the piston.