Curtain Airbag Sub-Chamber Layout for Side Window Gap Coverage
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Solution Overview
Problem
Curtain airbags often fail to adequately cover the protective area due to insufficient tab length, leading to gaps below the side window during deployment, which compromises occupant protection.
Innovation Solution
The airbag device incorporates a sub chamber with a bridge shape and a tab attachment system that ensures the cushion is suspended correctly, allowing the sub chamber to cover the gap below the side window by expanding outward and being restricted by the roof side rail, while maintaining suitable deployment behavior.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the tab length is increased to cover the protective area including the gap below the side window, then the coverage area is improved, but the deployment behavior and stowed state shape deteriorate
Solution Approach 1:
The cushion is divided into two separate chambers: a main chamber that handles the primary deployment and a sub chamber that specifically covers the gap below the side window. This segmentation allows each chamber to be optimized for its specific function, with the sub chamber extending the protective area without compromising the main chamber's deployment behavior
Solution Approach 2:
The sub chamber is stowed in a folded state at a portion of the second gas supply opening on the vehicle interior surface of the front chamber, effectively nesting the sub chamber within the main chamber's structure. This nesting allows the sub chamber to be compact during stowage while still providing additional coverage when deployed
2Area of stationary object
If the tab length is increased to ensure complete coverage, then the protective area is improved, but the stowed state shape and deployment direction deteriorate
Solution Approach 1:
By dividing the cushion into main and sub chambers, the sub chamber can be specifically designed to extend into the gap area while the main chamber maintains its optimized stowed shape. The sub chamber's bridge shape with legs allows it to extend laterally without affecting the overall cushion's stowed configuration
Solution Approach 2:
The sub chamber extends in the lateral direction (width-wise) rather than extending the tab length in the vertical direction. This dimensional change allows the protective area to be expanded into the gap below the side window without increasing the tab length, thereby maintaining the original stowed state shape
3Area of stationary object
If the sub chamber expands outward to cover the gap, then the coverage area is improved, but the position control deteriorates due to lack of restriction
Solution Approach 1:
The weather strip attached to the lower end of the roof side rail acts as an intermediary element that restricts the sub chamber's expansion. This intermediary component provides a physical boundary that controls the sub chamber's position and prevents uncontrolled expansion, while still allowing the sub chamber to extend far enough to cover the gap below the side window
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 solution ensures complete coverage of the protective area, enhancing occupant protection by reliably deploying the cushion to cover the entire specified region, including gaps below the side window.
Implementation Method 1
an inflator inserted inside the cushion that supplies gas to the cushion
Data Source
AI summary
An airbag device comprising: a cushion that is rolled and stowed at an upper part of a side surface and expands and deploys along the side surface, an inflator that is inserted in the cushion and provides gas to the cushion, and a tab for suspending the cushion from the upper part of the side surface, wherein the cushion includes: a duct provided with a tab extending in the front-to-back direction of the vehicle at the upper part of the side surface and that expands and deploys due to inflow of gas, a main chamber positioned below the duct, and a sub chamber provided at the upper part of the side surface, the upper end of the sub chamber is positioned above the upper edge of the side window, and the lower end of the sub chamber is positioned below the upper end of the duct.