Driver Airbag Cover-and-Cloth Layout to Prevent Head Retroflexion

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional driver's seat airbag devices may push an occupant's head backward when the occupant is out-of-position due to the airbag expanding and deploying in an unintended manner, causing physical strain, and existing countermeasures like rearwardly tilting flaps can shift or misalign during deployment.

Innovation Solution

A driver's seat airbag device with a cloth member that is sandwiched between the occupant and the airbag cushion, preventing the airbag from moving toward the head and using a cover member to secure the cloth member in place, ensuring it deploys correctly and resists the airbag's expansion pressure to maintain the occupant's safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a rearwardly tilting flap is provided in the airbag to suppress the rearwardly tilting moment of the head, then the safety aspect is improved, but the flap may shift from the initially set position due to vibration or momentum during deployment

Engineering Contradiction:
ImprovesafetyVSAvoidposition stability of cloth member
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The cloth member is pre-positioned on the upper portion of the airbag cushion before deployment, and the airbag cushion is designed to lead with the cloth member when expanding and deploying. This preliminary positioning ensures the cloth member is already in the correct location to suppress head retroflexion when the airbag deploys, preventing both the safety issue of insufficient head protection and the stability issue of the cloth member shifting during deployment

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If the airbag cushion expands and deploys to restrain the occupant, then the restraining function is improved, but the airbag may contact the head from below when the occupant is out-of-position, causing retroflexion

Engineering Contradiction:
Improverestraining functionVSAvoidhead retroflexion
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The cloth member acts as an intermediary between the airbag cushion and the occupant's head. It is positioned on the upper portion of the airbag cushion and extends forward, creating a interface that contacts the occupant's chest and abdomen first. This intermediary structure prevents the airbag cushion from directly contacting and pushing the head backward, thereby maintaining the restraining function while eliminating the harmful retroflexion effect

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3939859B1Airbag device for driver's seat
Publication Date: 2024.12.11 AUTOLIV DEV AB
  • EP3939859B1 patent drawingFigure 1(a)~1(b)
  • EP3939859B1 patent drawingFigure 2(a)~2(c)
  • EP3939859B1 patent drawingFigure 3(a)~3(d)

AI summary

[PROBLEM] To provide a driver's seat airbag device capable of fully restraining an occupant while taking into consideration safety aspects during expansion and deployment. [SOLUTION] A driver's seat airbag device 100 is provided with a variant steering wheel 106 and an airbag module 105. The variant steering wheel 106 has a module installation surface 109 and a cover member 110. The cover member 110 has a cover door 160 that opens when subjected to the expansion pressure of the cushion 104. The airbag module 105 includes a cloth member 150 that is applied over the cushion 104. The cloth member 150 has a front end side 150a connected to the inflator 112, and a rear end side 150b, which is the free end. The airbag module 105 has the cushion 104 in stowed form, and the cloth member 150 is passed over the cover member 110 side of the cushion 104, and the cloth member 150 is sandwiched between the cover member 110 and the cushion 104 in stowed form.