Hydraulic Shock Absorber Compensation Module With Acceleration-Adaptive Diaphragm

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Solution Overview

Problem

Existing hydraulic shock absorbers for vehicles face challenges in dynamically adjusting their compensation module's stiffness in response to varying acceleration conditions, which affects the pressure balance between compression and expansion chambers, potentially leading to cavitation and inefficient damping performance.

Innovation Solution

A hydraulic compensation module with an elastically deformable diaphragm that adjusts its stiffness based on the acceleration of the shock absorber body, utilizing a movable member linked to the diaphragm to exert force and control the fluid flow path between compression and compensation chambers, thereby varying the module's stiffness and opening point in response to acceleration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the compensation module uses a fixed stiffness design, then the structure is simple and reliable, but it cannot adapt to varying acceleration conditions, potentially leading to cavitation and inefficient damping performance

Engineering Contradiction:
Improveadaptability to acceleration conditionsVSAvoidcompensation module structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by making the diaphragm stiffness variable rather than fixed. The diaphragm's stiffness dynamically changes in response to acceleration forces acting on the shock absorber body, allowing the compensation module to adapt to varying operating conditions without requiring a completely reconfigurable structure.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by varying the physical parameter of diaphragm stiffness. Through the elastic deformation of the diaphragm under acceleration loads, the module's stiffness parameter automatically adjusts to match the dynamic requirements of different acceleration conditions, preventing cavitation while maintaining structural simplicity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the diaphragm stiffness is increased to prevent cavitation, then pressure balance is improved, but damping performance decreases due to excessive stiffness under normal conditions

Engineering Contradiction:
Improvecavitation preventionVSAvoiddamping performance
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The dynamics principle resolves this contradiction by making the diaphragm stiffness conditional rather than constant. Under normal operating conditions, the diaphragm maintains lower stiffness to optimize damping performance. When acceleration forces indicate cavitation risk, the diaphragm dynamically increases its stiffness to prevent cavitation, thus achieving both goals through time-dependent adaptation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The parameter changes principle allows the diaphragm stiffness parameter to vary based on operating conditions. The stiffness parameter is low during normal damping operations to maintain productivity, and increases only when acceleration conditions threaten to cause cavitation, thereby preserving reliability without permanently sacrificing performance.

Inventive Principle:
Principle #35Parameter changes

3Stress or pressure

If the compensation module is designed with high stiffness, then pressure drop control is improved, but energy transfer efficiency decreases during compression and expansion phases

Engineering Contradiction:
Improvepressure drop controlVSAvoidenergy transfer efficiency
Core Design Contradiction:
Stress or pressureVSUse of energy by moving object

Solution Approach 1:

The parameter changes principle optimizes energy transfer by allowing the diaphragm stiffness parameter to adapt to the phase of operation. During compression and expansion phases, the diaphragm maintains lower stiffness to minimize energy losses. When pressure drop control becomes critical, the stiffness parameter increases to provide necessary pressure regulation, thus balancing energy efficiency with pressure control requirements.

Inventive Principle:
Principle #35Parameter changes

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 effectively regulates pressure drops and fluid flow, enhancing damping performance by dynamically adjusting stiffness in response to acceleration, preventing cavitation and optimizing energy transfer during compression and expansion phases.

Implementation Method 1

a shutter (3) formed of at least one elastically deformable diaphragm (30) placed on the flow path (12) and on the breakthrough (50)

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

constraint means (6) linked to the diaphragm (30) and intended to exert a force on said diaphragm under the effect of an acceleration of the body of the shock absorber

Methodology Applied
Scientific EffectAcceleration force: Inertia

Implementation Method 3

compensation chamber (108) formed of an annular chamber, located between the cylinder (101) and the body (109), and comprising a volume of compressible gas (G)

Methodology Applied
Scientific EffectGas compressibility: Compression

Implementation Method 4

the piston (102) is provided with means of communication (106) between the two chambers (104, 105); said means (106) being intended to generate a pressure difference between the two chambers (104, 105) depending on the exchanges (or flow rates) of fluid between these two chambers

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Data Source

PatentEP1978277B1Compensation module for a hydraulic shock absorber of a vehicle and shock absorber equipped with such a compensation module
Publication Date: 2009.07.15 PEUGEOT CITROEN AUTOMOBILES SA
  • EP1978277B1 patent drawingFigure 1~2
  • EP1978277B1 patent drawingFigure 3~4
  • EP1978277B1 patent drawingFigure 5~6

AI summary

The module (1) has a hollow body (4) delimiting a fluid flow path (12) between compensation and compression chambers (108, 104). A hollow body (5) is arranged parallely in the compensation chamber, and has a bore (50) against the path. An obturator (3) has an elastically deformable diaphragm (30) placed on the path and the bore and restrained between the bodies. A stressing unit (6) exerts a force on the diaphragm due to acceleration of a body of a hydraulic shock absorber (100), such that stiffness of the module reduces due to the acceleration of the body of absorber in compression phase.