Airbag Diffuser Gas Flow Control for Balanced Deployment

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Solution Overview

Problem

Existing airbag devices may not sufficiently protect passengers due to inadequate expansion and deployment, depending on vehicle size, attachment location, and airbag shape, leading to insufficient protection during impacts.

Innovation Solution

The airbag device incorporates a diffuser with specific dimensions and openings that control the flow of gas from the inflator, ensuring balanced deployment in both horizontal and vertical directions, with a tubular shape open at both ends in the horizontal direction and closed in the upward and downward direction, to effectively restrain the passenger's upper body.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the gas discharged from the inflator rapidly expands the cushion, then the deployment speed increases, but the cushion may not deploy in a balanced manner and may not sufficiently protect the passenger

Engineering Contradiction:
Improvedeployment speedVSAvoidprotection effectiveness
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The diffuser acts as an intermediary component between the inflator and the cushion. It controls and distributes the gas flow from the inflator to different regions of the cushion, ensuring balanced expansion in both horizontal and vertical directions while maintaining rapid deployment speed for effective passenger protection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the diffuser opening is large to enable rapid gas flow, then the deployment speed increases, but the cushion may deploy too rapidly and unevenly

Engineering Contradiction:
Improvegas discharge rateVSAvoiddeployment uniformity
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The diffuser opening is segmented into multiple regions (first opening in horizontal direction, second opening in vertical direction) that independently control gas flow to different areas of the cushion. This segmentation allows the diffuser to maintain high overall gas discharge rate while ensuring uniform and balanced deployment across the entire cushion surface.

Inventive Principle:
Principle #1Segmentation

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 design ensures the airbag deploys in a well-balanced manner, quickly restraining the passenger's abdomen to chest and upper body, providing enhanced protection during collisions by controlling the gas flow and deployment speed.

Implementation Method 1

An inflator that rapidly discharges gas when an impact or the like occurs is disposed inside an airbag. The airbag is expanded and deployed by the gas discharged from the inflator.

Methodology Applied
Scientific EffectGas discharge:

Implementation Method 2

The gas discharged from the inflator flows out into the cushion through the diffuser. The dimensions and shape of the opening of the diffuser are appropriately set to prevent the protruding portion from deploying too rapidly.

Methodology Applied
Scientific EffectGas flow control:

Data Source

PatentEP3741629B1Airbag device
Publication Date: 2022.06.29 AUTOLIV DEV AB
  • EP3741629B1 patent drawingFigure 1
  • EP3741629B1 patent drawingFigure 2
  • EP3741629B1 patent drawingFigure 3

AI summary

[Problem]To provide an airbag device capable of controlling flow of gas discharged from an inflator. [Resolution Means]The airbag device is an airbag device that expands and deploys in a vehicle passenger compartment of a vehicle and restrains a passenger sitting in a first seat from a side, including: a cushion 41 provided with a horizontal portion 41d that deploys in a horizontal direction of the vehicle in an expanded and deployed state and a protruding portion 41e that deploys in an upward direction of the vehicle from a center portion of the horizontal portion 41d; a diffuser that is secured inside the cushion 41, that is open in the horizontal direction of the vehicle, closed in a downward direction of the vehicle, and partially or entirely closed in a direction toward the protruding portion; and an inflator 42 that is secured to the first seat, provided inside the diffuser, and that discharges gas for expansion and deployment.