Side Airbag Chamber Stabilization via Dual Gas Inlet

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Solution Overview

Problem

The existing side airbag devices with multiple chambers face instability in deployment behavior due to swinging of chambers during gas inflation, leading to unpredictable cushion attitudes and reduced occupant restraining performance.

Innovation Solution

A side airbag device configuration with a rear chamber and a front chamber, where gas is supplied from two directions through upper and lower openings on a sectioning wall, stabilizing the deployment behavior and using a partition to separate the main and middle restraining parts for controlled inflation and deployment, reducing abrupt pressurization on the occupant.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If gas is supplied from a single direction to the front chamber, then the structure is simple, but the cushion exhibits unstable deployment behavior and swinging

Engineering Contradiction:
Improvedeployment behavior stabilityVSAvoidgas supply structure complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The gas supply structure is segmented into multiple supply paths (upper opening and lower opening) to provide gas from different directions. This segmentation allows the gas flows to counterbalance each other, preventing swinging and stabilizing deployment behavior while maintaining structural simplicity through symmetric design.

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If the middle restraining part inflates simultaneously with the main part, then the inflation speed is fast, but abrupt pressurization occurs causing injury to occupants

Engineering Contradiction:
Improveoccupant injury riskVSAvoidinflation speed
Core Design Contradiction:
Object-affected harmful factorsVSSpeed

Solution Approach 1:

The rear chamber is segmented into a main part and a middle restraining part separated by a partition with a controlled opening. This segmentation enables staged inflation where the main part inflates first and the middle restraining part inflates subsequently, reducing abrupt pressurization and injury risk while maintaining overall fast deployment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The main part of the rear chamber inflates first as a preliminary action, preparing the cushion structure before the middle restraining part inflates. This preliminary inflation sequence ensures that the occupant restraint function is activated at the appropriate moment without sudden pressure spikes.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the cushion deploys in an unpredictable attitude, then the deployment is fast, but the occupant restraining performance declines

Engineering Contradiction:
Improveoccupant restraining performanceVSAvoidcushion attitude stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The sectioning wall has asymmetric opening placements (upper opening in the upper rear part, lower opening in the lower front part) that create balanced gas flow patterns. This asymmetric yet balanced design ensures stable cushion attitude and predictable deployment behavior, improving occupant restraining performance.

Inventive Principle:
Principle #4Asymmetry

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

This configuration stabilizes the deployment behavior of the cushion, enhances occupant restraining performance, and mitigates injuries by canceling out gas flow-induced swinging and avoiding abrupt pressurization, especially for out-of-position occupants.

Implementation Method 1

an inflator which generates gas

Methodology Applied
Scientific EffectGas generation through chemical reaction: Chemical Bonding

Implementation Method 2

gas is supplied to the front chamber which inflates later from two locations, namely, the upper opening in an upper-side rear part of the rear chamber which inflates first and the lower opening in a front-side lower part of the rear chamber. In other words, gas flows into the front chamber from two directions, namely, from the rear and from below.

Methodology Applied
Scientific EffectGas flow: Fluid Spray

Implementation Method 3

a cushion which receives the gas and inflates and deploys at the side of a seat back of the vehicle seat during a vehicle emergency

Methodology Applied
Scientific EffectGas expansion under pressure: Pressure Increase

Data Source

PatentEP3173295B1Side air-bag device
Publication Date: 2019.04.24 AUTOLIV DEV AB
  • EP3173295B1 patent drawingFigure 1(a)~1(b)
  • EP3173295B1 patent drawingFigure 2
  • EP3173295B1 patent drawingFigure 3(a)~3(c)

AI summary

Provided is a side airbag device which is capable of further stabilizing a deployment behavior of a cushion having a plurality of chambers. A side airbag 100 includes: an inflator 110; a rear chamber 114 which inflates and deploys at a side part 108 of a seat back 106 and which includes a middle restraining part 122 that protrudes toward the front of a vehicle from the seat back 106 to restrain a part of an occupant 118 and a main part 120 positioned at the rear side of the vehicle than the middle restraining part 122; a sectioning wall 124 which constitutes a front edge and an upper edge of the rear chamber 114 and which has a prescribed width in a vehicle width direction; a front chamber 116 which inflates and deploys into areas toward the front of the vehicle and the upper part of the vehicle from the sectioning wall 124; an upper opening 126 which is formed on the sectioning wall 124 in a rear part of the upper edge of the rear chamber 114; and a lower opening 128 which is formed on the sectioning wall 124 in a lower part of the front edge of the rear chamber 114.