Clipped Bumper Frame and Absorber Assembly for Pedestrian Impact

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Solution Overview

Problem

Current vehicle front faces with bumper frames are complex, heavy, and costly due to complex assembly requirements, and struggle to meet stringent safety and impact test standards, particularly in pedestrian impacts.

Innovation Solution

A simplified front face design featuring a bumper frame directly fixed to a bumper absorber via clipping means, with elastic deformation and frangible zones to absorb forces and separate in pedestrian impacts, eliminating the need for brackets and reducing assembly complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a complex bumper frame structure with brackets and screws is used, then the structural strength and rigidity are improved, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improvestructural strengthVSAvoidassembly complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent combines the bumper frame and absorber into a single integrated component, eliminating the need for separate brackets and screws. The frame is formed as one piece with the absorber, reducing assembly complexity while maintaining structural strength through the integrated design.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The bumper frame is designed to perform multiple functions simultaneously: it provides structural support, absorbs impacts, and integrates mounting features directly into its structure. This multi-functionality eliminates the need for separate components while maintaining all necessary structural capabilities.

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

2Device complexity

If a simplified bumper frame structure is used, then the device complexity and manufacturing cost are reduced, but the structural strength and impact resistance may deteriorate

Engineering Contradiction:
Improveassembly simplicityVSAvoidimpact resistance
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

By merging the frame and absorber into one integrated component, the patent achieves both simplification and strength. The integration allows for optimized load paths and structural continuity that maintain impact resistance while reducing assembly complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The bumper frame is made from a composite material or multi-layer structure that provides high strength-to-weight ratio. This allows the simplified single-piece design to maintain adequate impact resistance despite reduced structural complexity.

Inventive Principle:
Principle #40Composite materials

3Stability of the object's composition

If rigid fixing between frame and absorber is used, then the structural stability is improved, but the flexibility to absorb vertical forces deteriorates

Engineering Contradiction:
Improvestructural stabilityVSAvoidvertical flexibility
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent incorporates elastic elements or flexible joints within the integrated frame structure that allow dynamic adjustment. These elements enable the frame to flex vertically under load while maintaining overall structural stability, adapting to varying force conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The frame design includes variable stiffness regions where the material properties or geometric parameters change along the structure. This allows rigid sections for stability where needed and flexible sections for vertical movement where required, optimizing both structural stability and adaptability.

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

This design reduces production costs, simplifies assembly, and enhances flexibility and safety by allowing easy absorption of forces while ensuring compliance with impact tests and minimizing pedestrian injury.

Implementation Method 1

each fixing lug is designed to undergo elastic deformation so as to allow relative movement of the bumper frame and the absorber along a vertical axis of the vehicle equipped with the front face, under the effect of a force along the vertical axis of between 40 and 100 DaN

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

each fixing lug has at least one frangible zone designed to break in the event of a pedestrian impact suffered by the vehicle equipped with the front face

Methodology Applied
Scientific EffectFracture: Fracture Mechanics

Data Source

PatentEP4403420A1Front face having a frame clipped on an absorber
Publication Date: 2024.07.24 STELLANTIS AUTO SAS
  • EP4403420A1 patent drawingFigure 1
  • EP4403420A1 patent drawingFigure 2
  • EP4403420A1 patent drawingFigure 3

AI summary

The invention relates to a front face (1) of a motor vehicle comprising a bumper frame (2) designed to support the attachment of a bumper skin, the front face (1) further comprising a bumper absorber (3), the frame (2) comprising at least one attachment tab (6) extending from the bumper frame (2) to a free end (7) provided with clipping means (8), the bumper absorber (3) having at least one clipping interface from material with the absorber (3) and designed to cooperate with clipping means (8) of a attachment tab (6) to allow the attachment by clipping of the frame (2) onto the bumper absorber (3).