Two-Chamber Inflatable Cushion with Sequential Gas Venting
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Solution Overview
Problem
Single-chamber airbags are inefficient in providing differential support to a vehicle occupant's head and chest, as they require excessive gas for deployment and do not account for the varying masses of these body regions.
Innovation Solution
A two-chamber inflatable cushion system where a primary chamber is inflated first, and then the gas is vented to a secondary chamber, allowing for a predetermined pressure to be reached before inflating the smaller secondary chamber, thereby reducing the overall gas usage and optimizing support for both regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-chamber cushion is used to restrain both head and chest, then the structure is simple, but the gas consumption is excessive and differential support is not provided
Solution Approach 1:
The airbag cushion is divided into two separate chambers: a first chamber for restraining the chest and a second chamber for restraining the head. This segmentation allows each chamber to be optimized for its specific function and enables differential gas distribution, reducing overall gas consumption while providing tailored support for different body regions with different masses.
2Device complexity
If a single-chamber cushion is used, then the structure is simple, but differential support for head and chest is not provided
Solution Approach 1:
The airbag cushion is divided into two separate chambers: a first chamber for restraining the chest and a second chamber for restraining the head. This segmentation allows each chamber to be optimized for its specific function and enables differential gas distribution, reducing overall gas consumption while providing tailored support for different body regions with different masses.
3Quantity of substance
If a two-chamber design is used, then gas consumption is reduced, but the device complexity increases
Solution Approach 1:
The airbag cushion is divided into two separate chambers: a first chamber for restraining the chest and a second chamber for restraining the head. This segmentation allows each chamber to be optimized for its specific function and enables differential gas distribution, reducing overall gas consumption while providing tailored support for different body regions with different masses.
Solution Approach 2:
A valve mechanism serves as an intermediary component that controls gas flow between the two chambers. The valve allows gas to be distributed from a common source to the first chamber, and then selectively transferred to the second chamber based on deployment conditions, enabling complex gas management with a relatively simple additional component.
4Productivity
If inflation gas is directed to both chambers simultaneously, then both regions are inflated, but gas usage is inefficient
Solution Approach 1:
The inflation process follows a sequential pattern where the first chamber (chest) is inflated first to provide immediate protection to the heavier mass region. Only after the first chamber is properly inflated does the system then inflate the second chamber (head). This preliminary action ensures that gas is used efficiently by prioritizing the more critical chest restraint before allocating remaining gas to the head chamber.
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 two-chamber design achieves a 40% reduction in gas usage, allowing for effective restraint of both the chest and head with higher peak pressures, using 60% of the inflator output required for a single-chamber cushion, while minimizing the size, weight, and cost of the airbag module.
Implementation Method 1
The primary inflatable chamber having an inlet opening for receipt of an inflation gas
Implementation Method 2
the secondary inflatable chamber being in fluid communication with the primary inflatable chamber such that the inflation gas must travel through the primary inflatable chamber prior to reaching the secondary inflatable chamber
Implementation Method 3
the portion of the primary inflatable chamber being configured such that the inflation gas must travel into the primary inflatable chamber and create a first predetermined pressure in the primary chamber prior to the inflation gas passing through the portion and into the secondary inflatable chamber
Data Source
AI summary
An inflatable cushion for use in an airbag module is provided. The inflatable cushion generally includes a primary inflatable chamber configured for deployment from the air bag module, the primary inflatable chamber having an inlet opening for receipt of an inflation gas and the primary inflatable chamber defines a first volume. A secondary inflatable chamber secured to the primary inflation chamber, the secondary inflatable chamber defining a second volume, the second volume being less than the first volume and the secondary inflatable chamber being in fluid communication with the primary inflatable chamber such that the inflation gas must travel through the primary inflatable chamber prior to reaching the secondary inflatable chamber.