Vehicle Interior Trim Airbag Flap Retention Hinge

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Solution Overview

Problem

Existing interior trim assemblies for motor vehicles do not adequately ensure the safe retention of airbag flaps during deployment, risking injury to occupants due to insufficient reinforcement and potential breakage of the hinge strip.

Innovation Solution

The interior trim assembly incorporates a reinforced hinge strip with a protective element molded over the hinge portion, a reinforcing element covering the frame portion, and a deflector that partially obstructs the airbag's passage, designed to pivot and deflect the airbag, preventing excessive stress on the strip and ensuring the flap remains in place.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the hinge strip is used to retain the airbag flap during deployment, then the flap can pivot to free the passage, but the strip may break due to excessive stress and the flap may be thrown into the passenger compartment injuring occupants

Engineering Contradiction:
Improveflap retention safetyVSAvoidhinge strip strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

A protective element is molded over the hinge portion of the strip to provide beforehand cushioning and protection during airbag deployment. This protective element absorbs and distributes the excessive stress generated when the airbag inflates, preventing the strip from breaking while allowing the flap to pivot freely. The protective element acts as a pre-positioned safety mechanism that activates during deployment to protect occupants.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Strength

If the strip is completely overmolded with plastic material to reinforce it, then the strip strength is improved, but the manufacturing complexity and cost increase

Engineering Contradiction:
Improvestrip strengthVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

Instead of completely overmolding the entire strip, the invention applies the protective element locally only over the hinge portion where stress concentration occurs during deployment. This localized reinforcement provides the necessary strength improvement exactly where needed, while avoiding the increased manufacturing complexity and cost that would result from complete overmolding of the entire strip structure.

Inventive Principle:
Principle #3Local quality

3Force

If a deflector is added to partially obstruct the airbag passage and deflect the airbag, then the stress on the strip is reduced, but the device complexity increases

Engineering Contradiction:
Improveforce distributionVSAvoidassembly complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The deflector function is merged with the existing protective element that is already molded over the hinge portion. The protective element is designed to serve dual purposes: protecting the strip from excessive stress and acting as a deflector to redirect the airbag flow. This merging of functions reduces the need for separate deflector components, thereby limiting the increase in device complexity while still achieving effective force distribution.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2334520B1Interior trim assembly for a motor vehicle and motor vehicle
Publication Date: 2014.01.15 FAURECIA INTERIEUR IND
  • EP2334520B1 patent drawingFigure 1
  • EP2334520B1 patent drawingFigure 2
  • EP2334520B1 patent drawingFigure 3

AI summary

This assembly is of the type comprising a framework (14) and a panel (16) for concealing an airbag comprising a flap (28), a peripheral region (30) surrounding the flap (28) and attached to the framework (14), and a hinge-forming strip (34) having a flap portion (36) attached to the flap (28), a framework portion (40) attached to the framework (14) and a hinge portion (42) extending between the flap portion (36) and the framework portion (40). According to one aspect of the invention, the region of the hinge portion (42) adjacent to the framework portion (40) is covered with a protective element (50) and the region of the hinge portion (42) adjacent to the flap portion (48) is uncovered.