Elastomer End Stop for Two-Wheeler Spring-Damper Stroke Limiting

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Solution Overview

Problem

Existing spring-damper systems for two-wheeled vehicles face challenges in operational reliability, particularly in managing mechanical overloads and maintaining effective energy storage and damping performance across varying road conditions.

Innovation Solution

Incorporating a cup-shaped elastomer element with a barrel-shaped contour as an end position stop, which limits the piston stroke and converts kinetic energy into thermal and potential energy, ensuring the spring-damper system's components move in sync and reducing the risk of mechanical damage from overloads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the piston stroke is limited by a rigid stop, then the mechanical overload is prevented, but the kinetic energy cannot be effectively converted and absorbed

Engineering Contradiction:
Improveoperational reliabilityVSAvoidkinetic energy conversion
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The elastomer element converts the harmful kinetic energy from sudden piston movements into useful thermal energy through viscoelastic deformation. The material's inherent damping properties transform the energy that would otherwise cause damage into heat, while the gradual deformation prevents mechanical shock and overload.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The invention changes the physical parameters of the stop mechanism by using an elastomer with specific hardness (15-85 Shore D) and viscoelastic properties. This allows the stop to deform gradually under load, changing from a rigid, instantaneous stop to a compliant, energy-absorbing element that maintains system reliability while managing kinetic energy.

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If a soft elastomer material is used for the end stop, then the kinetic energy absorption is improved, but the structural strength and durability decrease

Engineering Contradiction:
Improvekinetic energy absorptionVSAvoidstructural strength
Core Design Contradiction:
Loss of energyVSStrength

Solution Approach 1:

The invention optimizes the hardness parameter of the elastomer within the range of 15-85 Shore D, finding the optimal balance between energy absorption and structural strength. This parameter optimization allows the material to be soft enough to absorb kinetic energy effectively while remaining strong enough to maintain structural integrity and durability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The elastomer element functions as a composite solution combining the benefits of soft materials (energy absorption) and rigid structures (strength). The viscoelastic properties of the elastomer create a material behavior that exhibits both flexible energy dissipation and sufficient structural support, effectively combining properties of seemingly contradictory materials.

Inventive Principle:
Principle #40Composite materials

3Loss of energy

If the end stop is designed to contact at partial stroke, then the energy conversion efficiency is improved, but the complexity of positioning and alignment increases

Engineering Contradiction:
Improveenergy conversion efficiencyVSAvoidpositioning and alignment complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The elastomer element automatically positions itself to contact the piston at the appropriate partial stroke point through its deformation characteristics. The material's compliance allows it to engage gradually as the piston approaches the end position, eliminating the need for precise mechanical positioning features or complex alignment mechanisms.

Inventive Principle:
Principle #25Self-service

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 enhances the operational reliability of the spring-damper system by effectively managing energy storage and damping, reducing the risk of mechanical damage and improving the system's response to external forces, thereby providing better ride quality and durability.

Implementation Method 1

The end stop is elastically compressed. Due to the design of the end stop, the transferred kinetic energy is converted into both thermal energy and potential energy.

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The elastomer element has a hardness between 15 Shore D and 85 Shore D... the transferred kinetic energy is converted into both thermal energy and potential energy

Methodology Applied
Scientific EffectViscoelastic damping: Viscoelasticity

Data Source

PatentEP4310363A1Spring-damper system having an end position stop and two-wheeled vehicle having a spring-damper system
Publication Date: 2024.01.24 ZIMMER GUNTHER
  • EP4310363A1 patent drawingFigure 1
  • EP4310363A1 patent drawingFigure 2
  • EP4310363A1 patent drawingFigure 3

AI summary

The invention relates to a spring-damper system with a spring energy storage device and a hydraulic cylinder-piston unit connected in parallel to it. The cylinder unit comprises a cylinder and a piston that is displaceable within the cylinder and separates a first displacement space from a second displacement space. A hydraulic connection links the first displacement space and the second displacement space. The invention also relates to a two-wheeled vehicle with such a spring-damper system. The spring energy storage device or the cylinder-piston unit has at least one end stop to limit the stroke of the piston. The end stop has a cup-shaped elastomer element with a barrel-shaped outer contour, which is oriented opposite to one of the stroke directions of the piston. The elastomer element has a hardness between 15 Shore D and 85 Shore D. The present invention increases the operational reliability of a spring-damper system.