Dual-Chamber Airbag Tether Design for Rapid Deployment
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Solution Overview
Problem
Existing passenger airbag modules have complex manufacturing processes and high costs due to the need for forming inner bags with branch sections, which complicates the deployment mechanism and increases production expenses.
Innovation Solution
A passenger airbag module with a dual-chamber airbag cushion design, featuring a tether that divides the cushion into upper and lower chambers, using transfer holes to manage gas pressure and deploy the airbag in a predetermined position, thereby protecting the occupant's head and chest efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If an inner bag with branch sections is formed in the bag body to enable primary expansion, then the airbag can be instantly deployed, but the manufacturing process becomes complicated and manufacturing cost increases
Solution Approach 1:
The airbag cushion is divided into an upper chamber and a lower chamber separated by a tether, allowing the upper chamber to expand first and the lower chamber to expand subsequently. This segmentation enables staged deployment without requiring complex inner bag structures with branch sections, simplifying manufacturing while maintaining fast deployment speed.
Solution Approach 2:
Transfer holes are introduced as intermediary structures in the tether to control gas flow from the upper chamber to the lower chamber. These holes act as mediators that enable sequential expansion of the two chambers without requiring complex internal bag structures, thus achieving fast deployment with simpler manufacturing.
2Reliability
If an inner bag with branch sections is formed in the bag body, then reliable occupant restraint is achieved, but the number of components and manufacturing steps increases
Solution Approach 1:
The airbag cushion is segmented into upper and lower chambers that expand in sequence, with the upper chamber providing initial protection and the lower chamber providing subsequent protection. This segmentation achieves reliable occupant restraint through staged deployment without requiring the complex inner bag structure with multiple branch sections.
Solution Approach 2:
The tether serving as a structural element is combined with the function of gas distribution by incorporating transfer holes directly into it. This merging of structures reduces the total number of components and simplifies manufacturing while maintaining reliable occupant protection through controlled sequential expansion.
3Reliability
If gas pressure is uniformly distributed throughout the airbag, then comprehensive protection is provided, but deployment time increases
Solution Approach 1:
The airbag cushion is divided into upper and lower chambers that expand in sequence rather than simultaneously. The upper chamber expands first to provide immediate protection, followed by the lower chamber expansion through transfer holes. This segmented approach reduces deployment time while maintaining comprehensive protection effectiveness.
Solution Approach 2:
The gas pressure distribution follows a periodic pattern where the upper chamber receives gas pressure first, then the lower chamber receives gas pressure through the transfer holes after the upper chamber expands. This periodic action enables faster overall deployment while ensuring comprehensive occupant protection through staged pressure distribution.
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
The dual-chamber design allows for controlled and efficient deployment of the airbag, reducing manufacturing complexity and costs while effectively protecting occupants by concentrating gas flow and distributing pressure to prevent injuries.
Implementation Method 1
an explosive igniter and a gas generator installed in an inflator housing are sequentially ignited, so that high-pressure gas is generated
Implementation Method 2
The transfer holes are formed at edges of the tether to transfer gas pressure from the upper chamber to the lower chamber in correspondence with gas pressure variation
Data Source
AI summary
A passenger airbag module includes a housing, an inflator generating gas pressure according to a control signal of an electronic control unit, and an airbag cushion folded in the housing such that the airbag cushion is expanded in the form of a dual chamber. The airbag cushion is provided therein with a tether having a rectangular shape corresponding to a sectional shape of the airbag cushion. The tether is installed in the transverse direction to divide the airbag cushion into an upper chamber and a lower chamber. Transfer holes are formed at edges of the tether. In the passenger airbag module, the upper chamber is primarily expanded by concentrating gas flow into the upper chamber to instantly deploy the airbag cushion in the proper position, thereby safely protecting the occupants.