Hydraulic Compression Stop Assembly With Nested Pin Damping Boost

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing hydraulic dampers with compression stop assemblies require significant space, which can be a challenge in applications like MacPherson struts where a sufficient minimum bearing span is crucial, and there is a need for a solution that reduces operational length, is cost-efficient, and offers versatile tuning properties for additional damping force.

Innovation Solution

A hydraulic damper design featuring a compression valve assembly with a deflectable or floating disc and a pressure chamber, where a pin sliding within the piston rod generates pressure to increase the biasing load on the disc, facilitating additional damping force without increasing the assembly's operational length.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a compression stop assembly is provided in a hydraulic damper, then additional damping force is generated at the end of compression stroke, but the operational length and space required increases

Engineering Contradiction:
Improveadditional damping forceVSAvoidoperational length
Core Design Contradiction:
ForceVSLength of moving object

Solution Approach 1:

The pin is disposed slidably within the piston rod, nesting the compression stop mechanism inside the existing piston rod structure. This eliminates the need for external space while still providing the compression stop function through internal movement of the pin along the piston rod axis.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The invention utilizes the axial dimension of the piston rod by allowing the pin to slide along the axis, rather than requiring additional radial or longitudinal space. The compression stop function is achieved through axial displacement of the pin within the existing piston rod volume.

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

2Volume of moving object

If the minimum bearing span is decreased to accommodate compression stop assembly, then space for compression stop is provided, but proper operation in MacPherson struts is compromised

Engineering Contradiction:
Improvespace for compression stop assemblyVSAvoidproper operation in MacPherson struts
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The compression stop assembly is nested within the piston rod structure, with the pin sliding inside the piston rod. This nested configuration provides the necessary space for compression stop operation without reducing the minimum bearing span, ensuring reliable operation in MacPherson strut applications.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Adaptability or versatility

If a pin sliding mechanism is used for compression stop, then adjustable damping properties are achieved, but device complexity increases

Engineering Contradiction:
Improveadjustable damping propertiesVSAvoidpin sliding mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The pin sliding mechanism utilizes hydraulic pressure from the working liquid to provide the biasing force, eliminating the need for separate mechanical springs or complex actuation systems. The hydraulic pressure naturally biases the pin to project into the compression chamber, providing adjustable damping through simple pin displacement along the piston rod.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 effectively reduces the space occupied by the compression stop assembly while providing adjustable damping properties, ensuring proper operation in space-constrained applications and enhancing packaging efficiency.

Implementation Method 1

the pin, upon sliding inside the piston rod, facilitates a flow of the working liquid from the compression chamber into said pressure chamber to generate a pressure on said surface of said piston member to increase a biasing load on said at least one deflectable or floating disc

Methodology Applied
Scientific EffectHydraulic pressure: Pressure Increase

Implementation Method 2

The compression valve assembly comprises: at least one deflectable or floating disc covering compression flow passages

Methodology Applied
Scientific EffectFluid flow control: Valve

Implementation Method 3

a piston assembly slidably disposed inside the main tube, attached to a piston rod that extends outside the hydraulic damper through a sealed piston rod guide located at the open end, dividing the main tube into a rebound chamber and a compression chamber and configured to generate a damping force

Methodology Applied
Scientific EffectHydraulic damping: Damping

Data Source

PatentEP4170197B1Hydraulic damper with a hydraulic compression stop assembly
Publication Date: 2024.10.09 BEIJING WEST IND CO LTD
  • EP4170197B1 patent drawingFigure 1~2
  • EP4170197B1 patent drawingFigure 3~4
  • EP4170197B1 patent drawingFigure 5~6

AI summary

The present disclosure relates to a hydraulic damper comprising a main tube, a piston assembly, a base valve assembly, and at least one hydraulic compression stop assembly cooperating with a compression valve assembly, and comprising a pin disposed slidably within the piston rod and biased to project an activating tip towards the compression chamber. Said compression valve assembly comprises at least one deflectable or floating disc covering compression flow passages, and biased by a piston member slidable along said axis and normally abutting a retaining surface, and a pressure chamber having one surface defined by a surface of said piston member abutting said retaining surface, wherein said pin upon sliding inside the piston rod facilitates a flow of the working liquid from the compression chamber into said pressure chamber to increase biasing load on said at least one deflectable or floating disc.