Air-bag Cushion Assembly with Segmented Support Chamber

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Solution Overview

Problem

Non-circular steering wheels with gaps in the rim pose challenges for traditional air-bag deployment, as they lack a supportive reaction force surface, leading to suboptimal performance when the occupant is out of position.

Innovation Solution

An air-bag assembly with a first chamber and a second chamber, where the second chamber provides localized support by being positioned adjacent to or attached to the first chamber, and is inflated to bridge gaps in the steering wheel rim, ensuring a reaction force surface is maintained during deployment, with independent inflation control and a control system to adjust deployment based on occupant position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a non-circular steering wheel with gaps in the rim is used, then the steering wheel design is more versatile and adaptable, but the air-bag deployment performance deteriorates due to lack of supportive reaction force surface

Engineering Contradiction:
Improvesteering wheel design versatilityVSAvoidair-bag deployment performance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The air-bag assembly is divided into a first chamber (main cushion) and a second chamber (support structure), where each segment serves a distinct function. The second chamber is segmented to bridge specific gaps in the steering wheel rim, providing localized support where needed while maintaining the versatile non-circular steering wheel design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second chamber acts as an intermediary element between the first chamber and the steering wheel rim. It bridges the gaps in the rim structure, transferring and distributing the reaction forces to maintain reliable air-bag deployment performance even when the steering wheel has non-traditional designs with gaps.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If a traditional single-chamber air-bag arrangement is used, then the device complexity is low, but the air-bag position stability deteriorates when the occupant is out of position

Engineering Contradiction:
Improveair-bag structure complexityVSAvoidair-bag position stability
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The air-bag system is segmented into a first chamber for cushioning and a second chamber for positional support. This segmentation allows the second chamber to actively counteract forces that would otherwise cause the air-bag to shift when the occupant is out of position, thereby enhancing stability without excessive complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second chamber is positioned to provide localized support at critical areas where the steering wheel rim has gaps. This local quality approach ensures that support is provided precisely where needed to maintain air-bag position stability, rather than requiring a completely redundant structural system.

Inventive Principle:
Principle #3Local quality

3Volume of moving object

If the second chamber is folded outside the first chamber in stored configuration, then the packaging efficiency is improved, but the deployment time increases

Engineering Contradiction:
Improvestored configuration volumeVSAvoiddeployment time
Core Design Contradiction:
Volume of moving objectVSLoss of time

Solution Approach 1:

The second chamber is folded and positioned outside the first chamber in the stored configuration, effectively nesting the support structure within the overall air-bag assembly footprint. This nesting approach optimizes packaging efficiency while maintaining rapid deployment capability through proper structural design.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 air-bag assembly effectively supports the air-bag cushion in all directions, maintaining its position relative to the occupant, even when the occupant is out of position, by providing localized support across gaps in the steering wheel rim, ensuring optimal deployment and safety.

Implementation Method 1

the second chamber is inflated by the at least one inflator to provide localised support across a gap in the steering wheel rim

Methodology Applied
Scientific EffectPressure: Pressure Increase

Implementation Method 2

the second chamber is located against a back panel of the first chamber to provide a reaction force surface to assist in maintaining the first chamber in a desired position

Methodology Applied
Scientific EffectReaction force: Reaction (physics)

Data Source

PatentEP3342649B1Air-bag cushion assembly
Publication Date: 2019.09.11 AUTOLIV DEV AB
  • EP3342649B1 patent drawingFigure 1~2
  • EP3342649B1 patent drawingFigure 3~4
  • EP3342649B1 patent drawingFigure 5~7

AI summary

An aspect comprises an air-bag assembly comprising: an air-bag arrangement movable from a stored configuration to a deployed configuration, the air-bag arrangement comprising a first chamber (15) and a second chamber (14), the second chamber (14) being positioned adjacent to, or attached to, the first chamber (15) and located to provide localised support to the first chamber (15); and at least one inflator coupled to the air-bag arrangement, wherein the at least one inflator is configured to inflate the air-bag arrangement when activated, and when in the inflated configuration, the second chamber is located against a back panel of the first chamber to provide a reaction force surface to assist in maintaining the first chamber in a desired position while the first chamber is deployed.