Tunable Diaphragm Suspension Limiter for Impact Management

Solution Overview

Problem

Conventional suspension limiters in vehicles do not effectively manage the rate of increase in load per unit travel of compression near full travel, leading to discomfort and potential damage, necessitating an improved solution.

Innovation Solution

A suspension limiter featuring a diaphragm element with a diaphragm disc, puck, and piston arrangement that reduces the rate of load increase by deforming elastically through full travel, allowing for tuning via additional diaphragm discs and spacer thickness adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional stop structures are used to limit suspension travel, then the suspension travel is limited, but the rate of load increase near full travel remains high causing discomfort and potential damage

Engineering Contradiction:

Improveimpact force on vehicle chassisVSAvoidstructural integrity

Core Design Contradiction:

Object-affected harmful factorsVSStrength

Solution Approach 1:

The diaphragm element is positioned to engage before the suspension reaches full travel, cushioning the impact in advance. The diaphragm deforms elastically to reduce the rate of load increase, preventing harsh bottoming out and protecting the chassis from high impact forces before they occur.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The diaphragm element changes the load-deflection characteristics of the suspension system by introducing a compliant element that deforms elastically. This changes the physical parameters of the system, reducing the stiffness near full travel and thereby reducing the rate of load increase that would otherwise occur with rigid stop structures.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If rigid stop structures are used to prevent further deformation, then suspension travel is limited, but passenger comfort and control are compromised due to high impact forces

Engineering Contradiction:

Improveride comfortVSAvoidimpact force

Core Design Contradiction:

Ease of operationVSForce

Solution Approach 1:

The diaphragm element is a flexible thin-walled structure that deforms elastically under load. This flexible structure replaces rigid stop structures, allowing the suspension to continue traveling while the diaphragm absorbs impact energy through elastic deformation, thereby maintaining ride comfort and reducing impact forces on passengers.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The diaphragm element engages before the suspension reaches its hard stop, cushioning the impact in advance. By deformting elastically during the approach to full travel, it reduces the rate of load increase and prevents harsh bottoming out, thereby improving passenger comfort before the impact occurs.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Object-affected harmful factors

If conventional jounce bumpers are used to cushion impact, then noise and vibration are attenuated, but the rate of load increase near full travel is not sufficiently reduced

Engineering Contradiction:

Improvenoise and vibrationVSAvoidrate of load increase

Core Design Contradiction:

Object-affected harmful factorsVSForce

Solution Approach 1:

The diaphragm element is a flexible thin-walled structure that deforms elastically under load. This flexible structure replaces rigid stop structures, allowing the suspension to continue traveling while the diaphragm absorbs impact energy through elastic deformation, thereby maintaining ride comfort and reducing impact forces on passengers.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The diaphragm element changes the load-deflection characteristics of the suspension system by introducing a compliant element that deforms elastically. This changes the physical parameters of the system, reducing the stiffness near full travel and thereby reducing the rate of load increase that would otherwise occur with rigid stop structures.

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 reduces the rate of load increase near full travel, enhancing ride comfort and preventing damage by allowing for in-situ tuning of the suspension limiter response to varying loads and terrains without relying on rubber or fluid-based structures.

Implementation Method 1

a diaphragm element configured to be placed in operable communication with a suspension such that a rate of increase in load per unit travel of compression of the suspension is reduced near a full travel of the suspension... the diaphragm element arranged to deform only elastically through the full travel of the suspension

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3517802B1Tunable suspension limiters for suspension arrangements

Publication Date: 2022.08.10 GOODRICH CORP

Figure 1
Figure 2
Figure 3

AI summary

A suspension limiter (100) includes a diaphragm element (116) configured to be placed in operable communication with a suspension such that a rate of increase in load per unit travel of compression of the suspension is reduced near a full travel of the suspension than would exist for the suspension if the diaphragm element (116) were not present, the diaphragm element (116) arranged to deform only elastically through the full travel of the suspension. Suspension arrangements and methods of loading suspension arrangements are also described.