Blade-Shaped Foam Shock Absorber for Constant Impact Force

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing foam shock absorbers for motor vehicles, particularly during low-speed impacts, often cause excessive force on pedestrians due to their design, which can lead to injuries, as they either work primarily in compression or experience inefficient energy absorption due to vertical spilling deformation modes.

Innovation Solution

A shock absorber with multiple blade-shaped elements spaced along its length, made of expanded polypropylene foam, designed to absorb energy by compressing initially and then laterally spilling, distributing the force more evenly and preventing excessive pressure on the impacted area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a solid cross-section foam shock absorber is used, then the shock absorber can absorb impact energy through compression, but the force applied back to the impacting element increases rapidly causing significant damage

Engineering Contradiction:
Improveimpact energy absorptionVSAvoidforce applied to impacting element
Core Design Contradiction:
Use of energy by moving objectVSForce

Solution Approach 1:

The foam shock absorber is divided into multiple foam elements arranged in parallel, each contributing to energy absorption. This segmentation allows the total impact energy to be distributed across multiple elements, preventing any single element from generating excessive reaction force on the impacting element while maintaining effective energy absorption capacity.

Inventive Principle:
Principle #1Segmentation

2Strength

If an L or C shaped cross-section foam shock absorber is used, then the structure provides geometric strength, but the walls experience vertical buckling that reduces shock absorption effectiveness

Engineering Contradiction:
Improvestructural strengthVSAvoidshock absorption effectiveness
Core Design Contradiction:
StrengthVSUse of energy by moving object

Solution Approach 1:

The shock absorber structure is segmented into multiple independent foam elements rather than using continuous L or C shaped walls. This segmentation prevents vertical buckling of long walls while each individual foam element maintains its load-bearing capacity and energy absorption properties through controlled compression.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The foam elements are designed to deform dynamically during impact, transitioning from initial compression to lateral spilling deformation mode. This dynamic deformation behavior allows the structure to adapt to impact forces without experiencing catastrophic buckling, maintaining both strength and energy absorption effectiveness.

Inventive Principle:
Principle #15Dynamics

3Object-affected harmful factors

If trapezoidal shock-absorbing elements with distal end size of human knee are used, then local shock absorption occurs, but the force on pedestrian increases too rapidly causing serious injury risk

Engineering Contradiction:
Improvepedestrian injury riskVSAvoidforce on pedestrian
Core Design Contradiction:
Object-affected harmful factorsVSForce

Solution Approach 1:

The shock absorber comprises multiple foam elements arranged in parallel, distributing the impact force across multiple contact points. This segmentation ensures that during pedestrian impact, the force is applied gradually as multiple elements engage sequentially, preventing sudden force spikes that could cause serious injury while maintaining effective shock absorption.

Inventive Principle:
Principle #1Segmentation

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

This design maintains a nearly constant force application during the impact, reducing the risk of injury and improving energy absorption efficiency, as the shock absorber's elements gradually engage to absorb energy laterally, preventing sudden increases in force.

Implementation Method 1

designed to absorb energy by compressing initially and then laterally spilling

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

as the shock absorber's elements gradually engage to absorb energy laterally

Methodology Applied
Scientific EffectDeformation: Deformation

Data Source

PatentEP4071001B1Foam schock absorber for automobile vehicle
Publication Date: 2023.10.11 COMPAGNIE PLASTIC OMNIUM SA
  • EP4071001B1 patent drawingFigure 1~2
  • EP4071001B1 patent drawingFigure 3~4
  • EP4071001B1 patent drawingFigure 5~6

AI summary

The shock absorber (3) for a motor vehicle is made of foam and comprises a set of shock-absorbing elements (6). The shock-absorbing elements (6) are arranged to form at least one row. The shock-absorbing elements (6) have a blade-like shape configured to be oriented vertically when the shock absorber (3) is mounted on a motor vehicle.