Inflatable Bag Gas Chamber Dimensions for Occupant Restraint
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Solution Overview
Problem
Existing occupant restraining devices for vehicles fail to effectively prevent the submarine phenomenon during frontal collisions, where the occupant slips forward and downward due to inadequate restraint mechanisms.
Innovation Solution
An occupant restraining device with an inflatable bag positioned between the seat cushion and seat pan, where the bag extends in the left-right direction and is inflated by a gas generator, with stationary sections at both ends fixed to the seat pan, optimizing the gas chamber dimensions to ensure sufficient inflation and restraint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the bag is inflated to push the seat cushion upward to prevent occupant forward movement, then the restraint effectiveness is improved, but the bag may displace in the front-back direction reducing reliability
Solution Approach 1:
The bag is divided into multiple sections: inflatable gas chambers at both ends that are fixed to the seat pan, and a middle section that remains movable to push the seat cushion. This segmentation allows the fixed ends to anchor the bag while the middle section performs the restraint function, resolving the contradiction between effectiveness and stability.
2Force
If the gas chamber dimensions are increased to ensure sufficient inflation for effective restraint, then the restraint force is improved, but the bag may not fit properly within the seat structure increasing device complexity
Solution Approach 1:
The patent specifies precise dimensional parameters for the gas chamber (L2/L1 ratio of 0.6-0.9 and L3/L2 ratio of 0.4-0.85) to optimize the balance between restraint force generation and proper integration within the seat structure. These parameter controls ensure sufficient inflation capability while maintaining compact fit.
3Stability of the object's composition
If stationary sections are fixed to the seat pan to prevent bag displacement, then position stability is improved, but the inflation volume may be reduced worsening restraint effectiveness
Solution Approach 1:
Different sections of the bag have different functional qualities: the end sections are fixed to provide stability, while the middle section remains free to inflate and push the seat cushion. This local differentiation of properties allows both stability and effectiveness to coexist.
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 device effectively suppresses forward movement of the occupant's waist by inflating the bag to increase seat cushion density, preventing displacement and ensuring effective restraint during collisions.
Implementation Method 1
a gas generator that inflates the bag when a vehicle is in an emergency situation... The bag has a gas chamber that is formed between the stationary sections and is inflated when gas is introduced into the gas chamber
Data Source
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AI summary
In an occupant restraining device having a bag whose opposite ends are fixed to a seat pan, an inflated state of a gas chamber of the bag is specified. Both ends of a bag 12 in a left-right direction thereof are provided with stationary sections 12a and 12a that are fixed to a seat pan 8. The stationary sections 12a and 12a have therebetween a gas chamber 15 that is inflated as a result of gas entering from an inflator 13. Regarding the bag 12, a value of L2 /L1, which is the ratio between a maximum width L2 of the gas chamber 15 in the left-right direction and a distance L1 between bolt through-holes 12b and 12b in the respective stationary sections 12a and 12a, is within a range of 0.6 to 0.9. Moreover, a value of L3 / L2, which is the ratio between a maximum width L3 of the gas chamber 15 in a front-back direction and L2, is within a range of 0.4 to 0.85. Furthermore, a value of L1 / L3, which is the ratio between L1 and L3, is less than or equal to 2.1.