Hydraulic Damper Compression Stop Axial Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hydro-mechanical compression stop assemblies in hydraulic dampers suffer from axial instability due to spring buckling, leading to unpredictable damping force generation and reduced compression stroke length, which complicates construction and manufacturing.
Innovation Solution
A hydro-mechanical compression stop assembly featuring an openwork sleeve construction with a telescopic arrangement, including a main flow channel and smaller auxiliary flow channels, and a spring that maintains axial stability and allows for adjustable damping force tuning based on piston position and velocity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional spring-based compression stop assembly is used, then damping force can be generated, but axial instability occurs due to spring buckling leading to unpredictable damping force
Solution Approach 1:
The compression stop assembly is segmented into multiple functional components: a telescopic arrangement with nested tubes, a closing member with closing shield, and a spring mechanism. This segmentation allows each component to perform its specific function while maintaining overall axial stability and preventing spring buckling through the structured nested configuration.
2Force
If the spring is designed to engage and close the main flow channel, then high damping force is generated, but the compression stroke length is reduced
Solution Approach 1:
The compression stop assembly uses a dynamic telescopic arrangement where the nested tubes can extend and compress. The spring is positioned to engage only at specific stroke positions, allowing full compression travel while generating high damping force only when needed near the end of the compression stroke, thus maximizing both stroke length and damping force effectiveness.
3Reliability
If a complex closing mechanism is used to ensure complete channel closure, then reliable damping force is achieved, but device complexity increases
Solution Approach 1:
The closing shield acts as an intermediary element between the spring and the main flow channel. This simple shield component, guided by the telescopic arrangement, provides reliable channel closure through a straightforward mechanical action without requiring complex mechanisms, thereby achieving dependable damping force generation with minimal complexity.
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 enhanced axial stability and progressive damping force increase, maximizing compression stroke length while maintaining simplicity and cost-effectiveness in construction.
Implementation Method 1
a spring (83) slidable along with the piston assembly and at its end distal to the piston assembly connected with means apt to close said at least one main flow channel while engaging said covering member
Implementation Method 2
both of the single-tube and dual-tube type, there is a piston connected to an activation piston rod. Defined are two chambers: an expansion or traction chamber and a compression chamber, flooded with liquid; the oil passes from one to the other through calibrated holes and valves existing in the piston
Implementation Method 3
The load of the compression chamber is increased in order to stop the brisk movement of the piston rod and by installing in said compression chamber a free control piston assisted by a spring that pushes it against a closing socket next to the tip of the piston rod
Data Source
Figure 1
Figure 2a~2b
Figure 2c~2d
AI summary
The present invention relates to a hydraulic damper (1), in particular a motor vehicle hydraulic suspension damper, comprising a tube (3) filled with working liquid, a piston assembly (4) disposed slidably inside the tube (3), dividing the tube into a rebound chamber (11) and a compression chamber (12), provided with a rebound (41) and compression (42) valve assemblies to control the flow of working liquid within the tube during rebound and compression stroke of the damper (1), and attached to a piston rod (5) led outside the damper (1), a fluid compensation chamber (13) located outside of the tube (3), a base valve assembly (7) located at the end of the compression chamber (12) for controlling the flow of working fluid between the compression chamber (12) and the compensation chamber (13), and a hydro-mechanical compression stop assembly (8) to generate an additional damping force at the end of the compression stroke and comprising a covering member (81) disposed in said compression chamber (12) and comprising at least one main flow channel (811), at least one auxiliary flow channel (85) between the compression chamber (12) and the compensation chamber (13), a spring (83) slidable along with the piston assembly (4) and at its end distal to the piston assembly (4) connected with means apt to close said at least one main flow channel (811) while engaging said covering member (81). In order to axially stabilize the spring (83), as well as to maximize available compression stroke length said hydro-mechanical compression stop assembly (8) further comprises a telescopic arrangement (82) attached slidably to the piston assembly (4) and comprising at least one sleeve (821, 822), wherein the sleeve most distal to said piston assembly (4) is an engaging sleeve (822) and said means apt to close said at least one main flow channel (811) are provided on the base (8225) of said engaging sleeve (822), wherein said spring (83) is compressed between the piston assembly (4) and said base (8225) to maintain an extended position of said telescopic arrangement (82) in its disengaged position.