Hydraulic Compression Stop Insert for Leakproof Damper Flow

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Solution Overview

Problem

Existing hydraulic damper assemblies with hydraulic compression stops (HCS) face issues with leakproofness and fluid flow restrictions due to high interference in press-fitting connections, which can damage components and impede the flow of working liquid.

Innovation Solution

A hydraulic damper assembly design featuring a hydraulic compression stop with an insert and fixing member that uses a press-fit engagement with a reduced interference, facilitated by a terminal section with a smaller external diameter and an internal flange for enhanced sealing, minimizing fluid flow restrictions while maintaining leakproofness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a high degree of interference (tightness) is implemented in the press-fit connection between the insert and fixing member, then leakproofness is improved, but the head portion can be damaged during the press-fitting process

Engineering Contradiction:
ImproveleakproofnessVSAvoidhead portion integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The insert is designed with a terminal section having a smaller external diameter than the main section. This creates a localized geometry where the terminal section provides sealing contact with the fixing member head portion, while the main section maintains structural integrity. The differentiated diameter distribution allows the sealing function to be concentrated in the terminal section, reducing the interference requirement overall while maintaining leakproofness at the critical sealing interface.

Inventive Principle:
Principle #3Local quality

2Force

If an insert is placed inside the compression chamber, then additional damping force is provided during compression stroke, but the flow of working liquid through the compression chamber and base valve is restricted

Engineering Contradiction:
Improveadditional damping forceVSAvoidworking liquid flow
Core Design Contradiction:
ForceVSQuantity of substance

Solution Approach 1:

The insert employs a stepped diameter configuration with a terminal section having a smaller external diameter than the main section. This dimensional variation creates additional flow passages around the insert, particularly through the annular space between the terminal section and the fixing member. This multi-dimensional flow path design allows the insert to provide damping force while simultaneously maintaining adequate working liquid flow through the compression chamber and base valve.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The insert is segmented into two distinct sections: a main section with larger external diameter for providing damping force, and a terminal section with smaller external diameter for sealing and maintaining flow. This segmentation allows each section to fulfill its specific function - the main section generates damping force during compression, while the reduced-diameter terminal section preserves fluid flow paths, thereby resolving the contradiction between force generation and flow maintenance.

Inventive Principle:
Principle #1Segmentation

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 design achieves minimal fluid flow restrictions and improved sealing with reduced risk of component damage during press-fitting, ensuring efficient operation and durability of the hydraulic damper assembly.

Implementation Method 1

The insert, located in the compression chamber, couples to the base valve. The insert has a main section and a terminal section. The terminal section is located adjacent to the fixing member. The main section is in fluid communication with the terminal section.

Methodology Applied
Scientific EffectPress-fit engagement: Mechanical Fastener

Implementation Method 2

A hydraulic compression stop is located in the compression chamber for providing an additional damping force during the compression stroke. The hydraulic compression stop includes an additional piston and an insert.

Methodology Applied
Scientific EffectHydraulic damping: Hydraulic Press

Implementation Method 3

A base valve is located in the compression chamber and coupled to the main tube for controlling working fluid flow between the compression chamber and the compensation chamber.

Methodology Applied
Scientific EffectFluid flow control: Valve

Data Source

PatentEP3933226A1Hydraulic damper assembly including a hydraulic compression stop
Publication Date: 2022.01.05 BEIJING WEST IND CO LTD
  • EP3933226A1 patent drawingFigure 1
  • EP3933226A1 patent drawingFigure 2
  • EP3933226A1 patent drawingFigure 3~4

AI summary

A hydraulic damper assembly comprises a main tube defining a fluid chamber. An external tube extends about the main tube defining a compensation chamber between the main and external tubes. A main piston, located in the main tube, divides the fluid chamber into a compression chamber and a rebound chamber. A piston rod couples to the main piston. A base valve, located in the compression chamber, couples to the main tube. A hydraulic compression stop, located in the compression chamber, includes an additional piston, an insert, and a fixing member. The additional piston couples to the main piston. The insert, located in the compression chamber, couples to the base valve. The insert has a main section and a terminal section. The terminal section having an external diameter that is less than an external diameter of the main section.