Quick-Release Strut Damper for MacPherson Suspension

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Solution Overview

Problem

Quick-release shock absorbers cannot be used as struts in Mac-Pherson suspensions, limiting their application.

Innovation Solution

A quick-release damping system is designed with a shock absorber body and a strut arrangement, featuring a piston with calibrated fluid passage means and a control mechanism that adjusts the relief passage between working chambers, allowing rapid expansion and partial or total closure, enabling the system to be used as a strut between unsprung and suspended vehicle parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a quick-release shock absorber is designed with a needle valve and needle valve seat for rapid expansion, then the wheel can quickly regain contact with the ground, but the device cannot be used as a strut in Mac-Pherson suspensions

Engineering Contradiction:
Improvewheel recontact speedVSAvoidapplication range
Core Design Contradiction:
SpeedVSAdaptability or versatility

Solution Approach 1:

The shock absorber is designed with a universal mounting structure that allows it to function both as a traditional shock absorber and as a strut in Mac-Pherson suspensions. The piston rod assembly with transverse wall arrangement and guide surface provides a standardized interface that accommodates both application types, eliminating the need for different designs.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The control means (needle valve) is made adjustable through the adjustment device that modifies the opening of the relief passage. This dynamic adjustability allows the system to adapt to different operational requirements and suspension configurations, enabling versatile application including strut mounting.

Inventive Principle:
Principle #15Dynamics

2Speed

If the relief passage is kept open for rapid expansion, then quick wheel recontact is achieved, but the damping control is lost

Engineering Contradiction:
Improveexpansion speedVSAvoiddamping control
Core Design Contradiction:
SpeedVSEase of operation

Solution Approach 1:

The needle valve controlled by the control rod provides dynamic control of the relief passage opening. The valve can be positioned anywhere along its travel range, allowing continuous adjustment between fully closed (damping control) and fully open (rapid expansion) states. This dynamic control mechanism resolves the contradiction by making both extremes and intermediate states accessible.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The elastic means (spring) provides a restoring force that automatically tends to close the relief passage, creating a feedback mechanism. When the control rod moves to open the valve, the spring stores energy and automatically pushes the needle valve toward the closed position when the control force is released, providing inherent damping control.

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If the piston rod is extended for strut mounting, then adaptability to Mac-Pherson suspension is achieved, but the structural complexity increases

Engineering Contradiction:
Improvestrut mounting capabilityVSAvoidstrut arrangement structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The piston rod assembly is segmented into distinct functional components: the piston rod itself, the transverse wall arrangement, and the guide surface assembly. This segmentation allows each component to perform its specific function independently while maintaining overall simplicity. The transverse wall with integrated guide surface is a compact segmentation that reduces total part count.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple functions are merged into single components to reduce overall complexity. The transverse wall arrangement serves both as a mounting surface for the control means and as part of the guide surface assembly. The guide surface is integrated directly into the transverse wall structure, eliminating the need for separate guide blocks or bearings, thereby simplifying the strut arrangement.

Inventive Principle:
Principle #5Merging (Combining)

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

Enables the quick-release damping system to function effectively as a strut in Mac-Pherson suspensions, allowing rapid wheel recontact with the ground and providing adjustable damping characteristics.

Implementation Method 1

a chamber (5) receiving an elastic means (6) acting in thrust on the movable assembly (4) and on the transverse wall arrangement (3)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a piston with rod (11; 12) dividing the internal volume of the shock absorber body into two working chambers in relation to each other via calibrated fluid passage means, carried by the piston

Methodology Applied
Scientific EffectFluid flow through calibrated passages:

Implementation Method 3

a relief device associated with the piston, and able to adopt a position of opening of a relief passage between the two working chambers allowing rapid expansion and a position of total or partial closure preventing rapid expansion

Methodology Applied
Scientific EffectPressure differential driven flow: Pressure Gradient

Data Source

PatentEP1989464B1Rapid relaxation damping system mounted as a strut
Publication Date: 2009.07.29 BOS SARL
  • EP1989464B1 patent drawingFigure 1
  • EP1989464B1 patent drawingFigure 2
  • EP1989464B1 patent drawingFigure 3

AI summary

The damping system, mounted as a strut, comprising a rapid-relaxation damper (1) and a strut arrangement (2) positioned around the damper and formed of at least one tube (20), the damper rod being hollow so as to accept a control means (15) for controlling a discharge device associated with the piston (11), is characterized in that the tube (20) is engaged around the rod (12) of the piston of the damper and at its end has a transverse wall arrangement (3) to which the end of the rod (12) of the damper is secured and in that the control means external to said tube collaborates with moving gear (4) slideably engaged on the tube (20), said moving gear (4) having limited capacity for axial movement on said bearing surface (200) and being intended to be fixed to one of the suspended or unsuspended parts of the vehicle.