Knee Airbag Fold Patterns for Upward Deployment

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Solution Overview

Problem

Conventional knee airbag assemblies often impart significant downward momentum to the airbag cushion during deployment, leading to inadequate coverage of the vehicle occupant and prolonged deployment times, as the distal portion is pushed from the housing, which can result in inefficient protection against collision-related injuries.

Innovation Solution

The airbag assembly incorporates a deployment accordion fold positioned below a rolled region, allowing the accordion fold to exit the housing before the rolled region, thereby minimizing downward momentum and enabling the airbag to quickly deploy upwardly, covering the occupant effectively by being 'pulled' from the housing with little initial downward motion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the distal portion of the airbag cushion is pushed from the housing during deployment, then the airbag can be deployed from the housing, but significant downward momentum is imparted to the airbag cushion, resulting in inadequate coverage and prolonged deployment times

Engineering Contradiction:

Improvedeployment speedVSAvoiddeployment time

Core Design Contradiction:

SpeedVSLoss of time

Solution Approach 1:

Instead of pushing the distal portion of the airbag cushion from the housing (conventional approach), the patent inverts the deployment sequence by having the proximal portion exit first through a deployment opening, allowing the airbag to be pulled upward rather than pushed downward. This reverses the direction of initial movement and eliminates harmful downward momentum.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent creates a deployed configuration where the proximal portion of the airbag cushion is positioned to exit the housing before the distal portion. This preliminary arrangement of the folded and rolled regions ensures that during deployment, the airbag follows an optimized path that minimizes downward momentum and reduces deployment time.

Inventive Principle:

Principle #10Preliminary action

2Area of stationary object

If the airbag cushion is pushed from the housing during deployment, then the airbag can be deployed, but the downward momentum causes inadequate coverage of the vehicle occupant

Engineering Contradiction:

Improvecoverage areaVSAvoiddownward momentum

Core Design Contradiction:

Area of stationary objectVSForce

Solution Approach 1:

The patent inverts the conventional deployment approach by having the proximal portion of the airbag cushion exit the housing first and the distal portion follow afterward. This reversal prevents the distal portion from being pushed forward with harmful downward momentum, allowing the airbag to cover the occupant's knee and lower leg areas more effectively.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The airbag cushion is divided into distinct regions (proximal portion with deployment opening, rolled region, and distal portion) that deploy in a specific sequence. This segmentation allows different parts of the airbag to perform different functions during deployment, with the proximal portion leading the way to maximize coverage area while minimizing harmful forces.

Inventive Principle:

Principle #1Segmentation

3Duration of action of moving object

If the distal portion of the airbag cushion is pushed from the housing, then deployment can occur, but the deployment time is prolonged

Engineering Contradiction:

Improvedeployment durationVSAvoiddeployment time

Core Design Contradiction:

Duration of action of moving objectVSLoss of time

Solution Approach 1:

The airbag cushion is pre-configured in a folded state where the proximal portion is positioned to exit the housing before the distal portion. This preliminary arrangement ensures that during collision, the airbag deploys in an optimized sequence that minimizes deployment time and maximizes protective coverage when needed most.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

By inverting the deployment sequence so that the proximal portion exits first rather than the distal portion being pushed first, the patent eliminates the time-consuming downward motion phase, thereby reducing overall deployment duration and improving response time during collisions.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentEP2776288B1Knee airbag folding patterns and assemblies and related methods

Publication Date: 2017.09.06 AUTOLIV ASP INC

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AI summary

An airbag assembly can include a housing and an airbag cushion within the housing in a packaged state. The airbag cushion can include a rolled region and an accordion fold. The rolled region and the accordion fold can be positioned within the housing so as to provide a desired trajectory when the airbag cushion is inflated.