Modular Crumple Zone Cavity for Lightweight Motor-Home Chassis

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Solution Overview

Problem

Lightweight chassis and superstructures in mobile homes and caravans are overly stiff, unable to absorb deformation energy in crashes effectively, and the addition of bumpers for crumple zones compromises storage space and aesthetic design.

Innovation Solution

A modular, replaceable cavity integrated into the chassis serves as a crumple zone, attached via flange means that slide off in collisions, decoupled from the main chassis to absorb energy and protect occupants, with energy absorption elements and predetermined breaking points for optimal protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If a lightweight chassis construction is used, then the total weight is reduced and fuel economy is improved, but the chassis becomes overly stiff and cannot absorb deformation energy in crashes

Engineering Contradiction:
Improvetotal weightVSAvoidcrash energy absorption
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The chassis is divided into a rigid support frame and separate replaceable cavity modules. The support frame maintains structural integrity and light weight, while the detachable cavities serve as sacrificial crumple zones that absorb collision energy through controlled deformation, protecting the main chassis structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cavity modules are designed as disposable or easily replaceable components. In the event of a collision, these cavities deform or fail to absorb energy, but can be quickly replaced without replacing the entire chassis or support frame, making the system cost-effective and maintaining safety over time.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Reliability

If bumpers are attached to provide crumple zones, then crash energy absorption is improved, but storage space is reduced and aesthetic design is compromised

Engineering Contradiction:
Improvecrash energy absorptionVSAvoidstorage space
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The crash protection function and storage function are merged into a single integrated component - the cavity module. These modules serve dual purposes: they provide crumple zone functionality for collision energy absorption and simultaneously serve as storage spaces for luggage and equipment, eliminating the need for separate bumpers that would consume storage volume.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cavity modules perform multiple functions simultaneously: structural support, energy absorption during collisions, and storage of cargo. This multi-functionality allows the chassis to maintain aesthetic integrity without additional external bumpers while preserving both safety and storage capacity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If additional edge strips or bumpers are attached for crash protection, then energy absorption is improved, but the aesthetic concept is compromised

Engineering Contradiction:
Improvecrash energy absorptionVSAvoidaesthetic design
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The crash protection elements are merged with the aesthetic body panels. The cavity modules are integrated into the chassis design as permanent body elements rather than add-on protective devices, maintaining the clean lines and aesthetic appearance of the vehicle while providing inherent crash protection through their structural design.

Inventive Principle:
Principle #5Merging (Combining)

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 allows for efficient energy absorption in crashes while maintaining the lightweight construction and aesthetic integrity, enabling easy replacement of damaged components without affecting the main chassis, thus enhancing safety and reducing damage to the vehicle.

Implementation Method 1

the flange means at least partially slide off the support frame in the event of a collision

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

the cavity on the support frame is releasably fastened, is constructed as a replaceable module and serves as a crumple zone for possible vehicle collisions

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 3

the necessary energy can be absorbed in the cavity in the event of a collision, which is deformed and possibly also destroyed as a result

Methodology Applied
Scientific EffectEnergy absorption: Damping

Data Source

PatentEP2934944B1Lightweight chassis
Publication Date: 2019.09.18 HYMER GMBH & CO KG
  • EP2934944B1 patent drawingFigure 1
  • EP2934944B1 patent drawingFigure 2
  • EP2934944B1 patent drawingFigure 3

AI summary

A motor-home chassis (1) comprising: a supporting frame (3) for providing the statically supporting properties, a bottom layer (6) for defining the construction plane for a living area above the bottom layer (6), an engine end (2) or connection means (25) for an engine end, at least one hollow compartment (10a-d), in particular a storage space in the area surrounding the supporting frame, characterized in that the hollow compartment can be detachably fastened to the carrying frame, is designed as a replaceable module, and serves as a crumple zone for any collisions in which the vehicle is involved.