Blow-moulded Airbag with Integral Restraints for Compact Packaging

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Solution Overview

Problem

Existing blow-moulded plastic airbags face challenges in packaging large airbags, such as side curtains and pedestrian airbags, due to difficulty in achieving tight uninflated configurations and controlling inflation to prevent excessive thickness upon deployment.

Innovation Solution

The airbag is designed with integrally formed plastic restraints between opposed layers, featuring tapered recesses to prevent layer separation and maintain a stable inflated shape, and is packaged using zig-zag folds that allow for compact storage and controlled inflation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If plastic blow-moulded airbags are used for large safety arrangements such as side curtains or pedestrian airbags, then the airbags can be easily manufactured and provide good impact absorption, but they become difficult to package tightly in their uninflated condition

Engineering Contradiction:
Improveease of manufactureVSAvoidpackaging volume
Core Design Contradiction:
Ease of manufactureVSVolume of moving object

Solution Approach 1:

The airbag is divided into multiple pleated sections that can be compactly folded and stacked together, transforming a single large-volume uninflated airbag into a segmented, space-efficient package

Inventive Principle:
Principle #1Segmentation

2Reliability

If plastic blow-moulded airbags are used for large safety arrangements, then they can provide self-supporting properties and absorb impact energy, but it becomes difficult to control their inflation to limit the depth of the airbag

Engineering Contradiction:
Improveimpact absorptionVSAvoidinflation depth control
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The airbag is divided into multiple pleated sections that constrain each other during inflation, preventing uncontrolled ballooning and maintaining a predictable, limited depth profile

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The plastic material forms flexible pleated walls that can deform and fold during inflation, allowing the airbag to expand in a controlled manner while maintaining structural integrity

Inventive Principle:
Principle #30Flexible shells and thin films

3Ease of operation

If plastic blow-moulded airbags are manufactured with thin wall sections for convenient installation, then they can be easily installed in the vehicle, but they become more difficult to package tightly when inflated to large sizes

Engineering Contradiction:
Improveinstallation convenienceVSAvoidpackaging volume
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The thin-walled airbag is segmented into pleated sections that can be compactly folded and stacked, enabling tight packaging despite the thin wall construction

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2639116B1Improvements in or relating to airbags
Publication Date: 2014.08.06 AUTOLIV DEV AB
  • EP2639116B1 patent drawingFigure 1~2
  • EP2639116B1 patent drawingFigure 3~4
  • EP2639116B1 patent drawingFigure 5~6

AI summary

An airbag (2) is disclosed for a motor vehicle safety arrangement, the airbag (2) being blow-moulded from plastics material to form an envelope (10) defining an inflatable volume (4) for the receipt of inflating gas between at least two opposed layers (11,12) of said plastics material. The envelope (10) has a restraint (15) formed integrally from said plastics material and which extends across said inflatable volume (4) between said opposed layers (11,12). The restraint (15) is configured to restrain movement of said layers (11,12) apart from one another in the region of the restraint (15) upon inflation of the airbag.