Airbag Panel Character Line Rupture Stability

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Solution Overview

Problem

The deployment of airbags in vehicles is unstable due to the uneven distribution of contact pressure caused by character lines on the design surface of panel members, which can lead to unpredictable rupture patterns of the tear lines.

Innovation Solution

Incorporating a tear line aligned with the character line on the panel member, along with sub-tear lines and a structured airbag retainer, to stabilize the rupture process and ensure consistent deployment pressure angles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If a character line is present on the design surface of the panel member, then the aesthetic appearance is improved, but the deployment stability of the airbag deteriorates due to uneven force distribution on the tear line

Engineering Contradiction:
Improvedesign surface appearanceVSAvoiddeployment stability
Core Design Contradiction:
ShapeVSReliability

Solution Approach 1:

The patent applies local quality by creating a relief structure specifically at the character line position on the panel member. This relief structure has a different thickness than the surrounding areas, allowing the character line to maintain its aesthetic appearance while the thicker portion provides structural support to ensure uniform force distribution on the tear line during airbag deployment, thus resolving the contradiction between appearance and deployment stability

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent transitions from a two-dimensional design surface to a three-dimensional structure by creating a relief structure with varying thickness. The character line is formed as a raised or recessed feature that extends through the thickness of the panel member, adding a dimensional element that simultaneously achieves aesthetic purposes and structural reinforcement for stable tear line rupture

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the tear line is made sharp and tapered to ensure stable rupture, then the rupture stability is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improverupture stabilityVSAvoidpanel member manufacturing
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges the tear line formation with the overall panel member molding process. The tear line is created as an integrated feature during the injection molding of the panel member, combining the structural formation with the aesthetic character line design. This integration reduces manufacturing steps and complexity while achieving the desired sharp, tapered tear line geometry for stable rupture

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3708437B1Airbag apparatus
Publication Date: 2023.07.26 TOYOTA JIDOSHA KK
  • EP3708437B1 patent drawingFigure 1
  • EP3708437B1 patent drawingFigure 2
  • EP3708437B1 patent drawingFigure 3

AI summary

An airbag apparatus includes an airbag (20) housed deployably, and an instrument panel (10) covering the airbag (20) in a deploying direction (24) and forming a design surface of a vehicle cabin. The instrument panel (10) includes, on the design surface facing the vehicle cabin, a character line (12) including continuous protrusions toward the deploying direction (24). The instrument panel (10) includes, on a surface facing the airbag (20) along the character line (12), a tear line (16) that ruptures at the time of deployment of the airbag (20).