Steering Column Gas Conduit for External Airbag Generator

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Solution Overview

Problem

The existing restraint systems for motor vehicle drivers face design limitations due to the space requirements of the gas generator, which restricts the flexibility of the steering wheel design and complicates the connection of the steering column to the steering wheel hub, especially when integrating a multi-stage gas generator within the steering column.

Innovation Solution

The gas generator is relocated outside the steering column, allowing for flexible steering wheel design, and the steering column serves as a gas conduction path to manage pressure pulses, filter particles, and prevent gas bag contamination, with optional components like diffusers and sealing mechanisms to ensure efficient gas flow and deployment control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the gas generator is integrated into the steering wheel, then the steering wheel design is constrained by the space requirements of the gas generator, but the driver restraint function is ensured

Engineering Contradiction:

Improvesteering wheel design freedomVSAvoiddriver restraint function

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The gas generator is extracted from the steering wheel and relocated to the steering column area. The patent describes that the gas generator (22) is arranged outside the steering column (16), specifically on the side of the hub (14) facing away from the steering wheel. This extraction resolves the space constraint issue while maintaining the restraint function through the gas conduction path established via the steering column.

Inventive Principle:

Principle #2Taking out (Extraction)

2Volume of moving object

If the gas generator is integrated into the steering column, then the steering column must have a large diameter, but the connection to the steering wheel hub becomes more complicated

Engineering Contradiction:

Improvesteering column diameterVSAvoidconnection complexity

Core Design Contradiction:

Volume of moving objectVSDevice complexity

Solution Approach 1:

The gas generator is extracted from the steering column interior and positioned externally on the hub side. The patent states that the gas generator (22) is arranged outside the steering column (16), which eliminates the need for a large steering column diameter and simplifies the connection structure between the steering column and steering wheel hub.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The steering column serves as an intermediary gas conduction path between the externally positioned gas generator and the airbag. The patent describes a flow connection established via the steering column, which acts as a mediator to transmit gas without requiring the generator to be integrated into the column structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Power

If a multi-stage gas generator is arranged inside the steering column, then the gas generation capability is enhanced, but the implementation becomes difficult

Engineering Contradiction:

Improvegas generation capabilityVSAvoidimplementation difficulty

Core Design Contradiction:

PowerVSEase of manufacture

Solution Approach 1:

The gas generator is extracted from the steering column interior and positioned externally, which simplifies the manufacturing and assembly process. The patent indicates that arranging the gas generator outside the steering column avoids the implementation difficulties associated with integrating multi-stage generators within the column structure.

Inventive Principle:

Principle #2Taking out (Extraction)

4Adaptability or versatility

If the gas generator is positioned outside the steering column, then the steering wheel design freedom is improved, but the gas conduction path becomes longer

Engineering Contradiction:

Improvesteering wheel design freedomVSAvoidgas conduction path length

Core Design Contradiction:

Adaptability or versatilityVSLength of stationary object

Solution Approach 1:

The steering column acts as an intermediary gas conduction path, efficiently transmitting gas from the externally positioned generator to the airbag. The patent describes the steering column as serving as a gas conduction path, which minimizes the effective conduction distance despite the external positioning of the generator.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 solution enhances design freedom for the steering wheel, improves vibration resonance, eliminates the need for a rotary transmitter, simplifies handling and approval processes, and ensures controlled gas bag behavior and safety without compromising driver safety.

Implementation Method 1

there is a flow connection between the gas generator (22) and the gas bag (20), which is established via a suitable connection of the gas generator (22) to the steering column (16) and its opening (24) on the steering wheel side

Methodology Applied

Scientific EffectGas flow through conduction path:

Data Source

PatentEP1854679B1Steering system with airbag for a motor vehicle

Publication Date: 2009.03.11 ZF AUTOMOTIVE SAFETY GERMANY GMBH

AI summary

A compact method of fitting an airbag system to a steering wheel has the gas generator (22) mounted outside the bottom of the steering column (30) with the gas flow connected to the airbag via the steering column. The design eliminates any cable feed through the steering system and the steering column becomes a gas duct with improved separation of pyrolytic particles from the airbag.