Vehicle Interior Trim Assembly With Controlled Breakage Lines

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Solution Overview

Problem

Existing vehicle interior surfaces are not designed to effectively limit injuries from bodily impacts during accidents, particularly when a victim's upper body collides with interior elements after being thrown through the windshield.

Innovation Solution

A trim panel with weakening lines and elastic material to facilitate controlled deformation and cohesion, reducing the risk of sharp fragments and enhancing the panel's ability to absorb impact forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the trim panel is made rigid to maintain structural integrity, then strength is improved, but the risk of sharp fragments and injury increases upon impact

Engineering Contradiction:
Improvestructural integrityVSAvoidsharp fragments
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The trim panel is divided into multiple portions by introducing weakening lines that create recesses in the material. These recesses segment the panel into controllable sections that can separate upon impact, preventing the formation of large sharp fragments while maintaining overall structural integrity during normal use

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The weakening lines with recesses are pre-formed in the trim panel during manufacturing, creating predetermined break zones before any impact occurs. This preliminary structuring ensures that when impact happens, the panel breaks in a controlled manner along these pre-defined lines rather than creating unpredictable sharp fragments

Inventive Principle:
Principle #10Preliminary action

2Object-affected harmful factors

If the trim panel is designed to break easily to reduce sharp fragments, then safety is improved, but structural integrity and cohesion worsen

Engineering Contradiction:
Improvesharp fragmentsVSAvoidcohesion
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The elastic material is applied specifically at the weakening lines where recesses are formed, creating localized zones of enhanced flexibility and cohesion. This local reinforcement allows the panel to break cleanly along predetermined lines while maintaining overall cohesion and preventing uncontrollable shattering

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The trim panel combines a rigid base material with elastic material applied at strategic locations (weakening lines). This composite structure provides both the rigidity needed for normal structural integrity and the controlled flexibility needed for safe breakage patterns when impacted

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If existing interior surfaces are used without special design, then manufacturing simplicity is maintained, but injury risk to victims increases during impact

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidinjury risk
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The weakening lines with recesses are integrated into the trim panel manufacturing process itself, segmenting the panel into controlled portions without requiring separate components or complex assembly steps. This maintains manufacturing simplicity while dramatically reducing injury risk through controlled breakage patterns

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

The trim panel design minimizes the risk of injury by allowing controlled breakage and maintaining cohesion, preventing sharp fragments and enhancing impact absorption.

Implementation Method 1

the weakening line 2 being associated with at least one elastic material 3 arranged to operate a joining between at least two portions 12, 13 of the trim panel 1

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4238834B1Trim assembly for vehicle interior
Publication Date: 2025.10.29 SMRC AUTOMOTIVE HLDG NETHERLANDS BV
  • EP4238834B1 patent drawingFigure 1~3
  • EP4238834B1 patent drawingFigure 4~5

AI summary

The invention relates to an assembly comprising a trim panel (1) for the interior of a vehicle, characterized in that one of the surfaces of the trim panel (1) comprises at least one weakening line (2) formed by a recess (21) in the thickness of the trim (1) and arranged across at least a part of the surface of the trim panel (1) so as to define a joining line between two adjacent portions (12, 13) of the trim panel (1), the weakening line (2) being associated with at least one elastic material (3) arranged to operate a joining between at least two portions (12, 13) of the trim panel (1), this elastic material (3) being positioned on either side of the weakening line (2) and/or in at least a part of the recess (21) of the weakening line (2).