Driver Airbag Cover Door Layout for Stable Steering Wheel Deployment
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Solution Overview
Problem
New steering wheels with irregular designs, lacking a circular shape, pose challenges for airbag deployment due to reduced contact range and unstable deployment movement, potentially leading to inadequate passenger restraint during emergencies.
Innovation Solution
The driver seat airbag apparatus features a cover door configuration that opens diagonally upward to prevent passenger contact, with a groove and hinge system allowing the cover door to move efficiently, and a flow-regulating material to ensure the airbag cushion expands rearward downward, stabilizing its position between the steering wheel and passenger.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the cover door opens directly above the hub, then the airbag cushion can be deployed, but the cover door may contact the passenger causing safety issues
Solution Approach 1:
The cover door is designed to open diagonally upward rather than directly upward, creating an asymmetric opening pattern that avoids the passenger area while still allowing airbag deployment. This diagonal opening trajectory prevents the cover door from contacting the passenger.
Solution Approach 2:
The cover is divided into multiple cover doors that can open independently in different directions. This segmentation allows specific portions of the cover to open toward safe zones while other portions remain positioned to protect internal components.
2Object-affected harmful factors
If the cover door opens diagonally upward, then passenger safety is improved, but the contact range with the steering wheel is reduced
Solution Approach 1:
The cover door opening motion is extended into a diagonal trajectory that combines vertical and horizontal components. This dimensional change allows the cover door to clear the passenger area while still maintaining sufficient contact with the steering wheel structure for stable airbag deployment.
Solution Approach 2:
Different regions of the cover door are designed with different opening characteristics. The portion near the hub opens diagonally to avoid passengers, while other portions maintain contact with the steering wheel to ensure deployment stability.
3Speed
If the airbag cushion expands upward, then deployment speed is improved, but the deployed position becomes unstable with irregular steering wheels
Solution Approach 1:
The airbag cushion expansion is made asymmetric with different expansion characteristics in different directions. The cushion expands more strongly in the rearward direction to achieve stable positioning against the steering wheel, while maintaining sufficient upward expansion for rapid deployment.
Solution Approach 2:
The expansion parameters of the airbag cushion are optimized to create a rearward downward movement pattern. This involves adjusting the gas flow distribution and cushion geometry to achieve the desired expansion trajectory that stabilizes the cushion position.
Data Source
Figure 1A~1B
Figure 2A~2C
Figure 3
AI summary
[Problem] To provide a driver seat airbag apparatus capable of fully restraining a passenger in terms of safety during expansion and deployment. [Resolution Means] A driver seat airbag apparatus 100 includes a steering wheel 106 and an airbag module 105. The steering wheel 106 has a central hub 108 and a rim 114. The rim 114 has a shape in which a portion of the upper portion of the hub 108 is omitted. The hub 108 includes: a module housing part 109 which houses the airbag module 105; and a cover 110 which covers the module housing 109 and is cleavable at the expansion pressure of the cushion 104. The cover 110 includes cover doors 162a, 162b which open at the expansion pressure of the cushion 104. When the cover 110 is cleaved, the cover doors 162a, 162b are open in the right and left diagonal upward directions when viewed from the center P3 of the hub 108, while a space portion S1 without the cover doors is formed in the direction directly above the center of the hub 108 when viewed from the center of the hub 108.