Airbag Reaction Chamber Layout for Longitudinal Occupant Control
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Solution Overview
Problem
Inflatable restraints in vehicles face challenges in effectively controlling occupant motion and dissipating energy due to the lack of suitable reaction surfaces during deployment, as conventional surfaces like windshields and dashboards are not optimally utilized for reaction forces.
Innovation Solution
The design incorporates an airbag assembly with a main chamber and a reaction chamber, where the reaction chamber moves laterally to engage the vehicle body structure, utilizing controlled gas flow and tethers to manage forces applied during longitudinal motion, allowing for efficient energy dissipation and reaction against the body structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional airbags are used with traditional reaction surfaces (windshield, dashboard), then the airbag can control occupant motion, but the reaction surfaces are not optimally utilized and may not be available in autonomous vehicles
Solution Approach 1:
The airbag is divided into two separate chambers: a main chamber for occupant engagement and a reaction chamber for engaging vehicle body structures. This segmentation allows each chamber to perform its specific function independently, enabling the airbag to operate effectively without relying on traditional reaction surfaces like windshields or dashboards.
Solution Approach 2:
The reaction chamber is positioned laterally adjacent to the main chamber, creating a lateral reaction force dimension perpendicular to the primary longitudinal motion control. This dimensional change allows the airbag to utilize vehicle side structures as reaction surfaces, providing versatility in scenarios where traditional forward-facing reaction surfaces are unavailable.
2Loss of energy
If the airbag uses a two-chamber configuration with lateral reaction, then energy dissipation is improved, but the device complexity increases
Solution Approach 1:
The main chamber and reaction chamber are merged into a single continuous airbag structure with a shared inflatable envelope. This merging approach allows both chambers to be inflated simultaneously from a single gas source, simplifying the overall system while maintaining the functional benefits of separate chambers for motion control and energy dissipation.
Solution Approach 2:
The reaction chamber serves multiple functions: it provides lateral reaction forces against vehicle body structures, dissipates energy through controlled deformation, and maintains structural integrity during deployment. This multi-functionality reduces the need for additional separate components, thereby managing device complexity.
3Force
If the reaction chamber is spaced from the seat assembly by the main chamber, then the airbag can engage the body structure effectively, but the gas pressure distribution becomes more complex
Solution Approach 1:
The main chamber acts as an intermediary structure between the reaction chamber and the seat assembly. It transmits forces and pressures while maintaining the necessary spacing, allowing the reaction chamber to engage the body structure effectively without direct contact with the seat assembly, thereby simplifying the pressure distribution mechanism.
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 configuration enhances the airbag's ability to react longitudinal forces by engaging the vehicle body, effectively dissipating energy and controlling occupant motion, even in scenarios where traditional reaction surfaces are not available, such as in fully autonomous vehicles.
Implementation Method 1
A first gas pressure in the reaction chamber may be higher than a second gas pressure in the main chamber when the airbag is in the inflated position
Implementation Method 2
The internal interface may include structures that allow controlled gas flow between main chamber and reaction chamber
Data Source
AI summary
A device includes a body structure, a seat assembly that is connected to the body structure, and an inflatable structure. The inflatable structure includes one or more surfaces that are configured to react forces by engaging with a first feature to control motion of a second feature.