Multi-Chamber Crash Box With Deformable Element for Energy Absorption

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Solution Overview

Problem

Existing crash boxes in vehicle crash management systems struggle to absorb varying levels of energy without significant weight increase or modification, necessitating a more flexible and adaptable solution to meet legislative requirements and improve energy absorption efficiency.

Innovation Solution

Incorporating a deformable element within the crash box's hollow profile, which absorbs additional impact energy without altering the external geometry or increasing weight, by allowing the deformable element to fold and extend the energy absorption capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the hollow profile wall thickness is increased to absorb more energy, then the energy absorption capability is improved, but the weight of the crash box increases

Engineering Contradiction:
Improveenergy absorption capabilityVSAvoidweight of crash box
Core Design Contradiction:
Use of energy by moving objectVSWeight of moving object

Solution Approach 1:

The hollow profile is divided into multiple chambers (at least two chambers) separated by partition walls. This segmentation allows each chamber to contribute to energy absorption independently through controlled deformation, increasing overall energy absorption capability without requiring a uniform increase in wall thickness throughout the entire structure, thereby avoiding excessive weight gain.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The partition walls are nested within the hollow profile, creating internal chambers that utilize the existing external geometry. This nesting approach allows the crash box to absorb more energy through internal structural deformation while maintaining the same external dimensions and avoiding additional weight from external modifications.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Use of energy by moving object

If the crash box structure is modified to increase energy absorption, then the energy absorption capability is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improveenergy absorption capabilityVSAvoidstructural complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The hollow profile is segmented into multiple chambers using partition walls, which can be integrated into the extrusion process. This segmentation creates distinct deformation zones that enhance energy absorption while the modular nature of the chambers allows for standardized manufacturing approaches, reducing overall manufacturing complexity despite the enhanced functionality.

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

Enhances energy absorption capability and withstands higher forces without changing the crash box's structure, offering a flexible and cost-effective solution for adapting to different crash requirements.

Implementation Method 1

When the impact occurs at higher speed, for example of the order of 10-15 km/hour, the bumper and the shock absorbers undergo plastic deformation. The crash management system could absorb at least in part the impact energy.

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

The crash boxes are designed to fold upon such frontal or rear impacts. In an impact, kinetic impact energy is converted into deformation work by forming folds in the deformation element itself.

Methodology Applied
Scientific EffectFolding: Folding

Data Source

PatentEP3994036B1Crash box containing a deformable element to extend the capacity of a crash box to absorb impact energy
Publication Date: 2025.09.03 CONSTELLIUM SINGEN GMBH
  • EP3994036B1 patent drawingFigure 1~2
  • EP3994036B1 patent drawingFigure 3~4
  • EP3994036B1 patent drawingFigure 5

AI summary

A crash box (3) comprising a hollow profile (38) extending along a longitudinal direction (X) and having a crush length (LCB), said hollow profile (38) having at least two chambers (4) characterized in that it comprises at least a deformable element (7, 7', 7") contained into at least one chamber (4) contributing to the energy absorption capability of said crash box (3).