Gas Generator Staged Combustion for Airbag Deployment
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Solution Overview
Problem
Existing gas generators for airbag systems face challenges in adjusting combustion performance to achieve desired gas output profiles, particularly in ensuring reproducible output performance for effective airbag deployment and occupant safety.
Innovation Solution
A gas generator design featuring two combustion chambers with distinct gas generating agents, where the first agent burns earlier than the second due to differently positioned communication nozzles, allowing for adjustable burn-up times and output profiles by varying nozzle positions and agent properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single combustion chamber is used with adjusted gas generating agent parameters, then the structure is simple, but the output performance reproducibility is insufficient
Solution Approach 1:
The combustion chamber is divided into two separate combustion chambers (first combustion chamber 30 and second combustion chamber 40) that communicate with the ignition chamber through different communication nozzles. This segmentation allows independent control of burn-up times for each gas generating agent, thereby improving output performance reproducibility while maintaining relatively simple structure
Solution Approach 2:
The axial positions of the first communication nozzle (80) and second communication nozzle (82) are adjusted to create different distances from the plenum chamber (50). By changing this geometric parameter, the burn-up time of the first gas generating agent (32) is made shorter than that of the second gas generating agent (42), enabling reproducible staged gas generation
2Productivity
If communication nozzles are positioned closer to the plenum chamber to increase gas generation rate, then the gas output speed increases, but the initial impact on occupants increases
Solution Approach 1:
The first communication nozzle (80) is positioned farther from the plenum chamber (50) than the second communication nozzle (82), creating a staged combustion sequence. The first gas generating agent (32) burns up earlier and at a controlled rate, providing preliminary gas generation that avoids excessive initial pressure buildup and reduces impact on occupants
Solution Approach 2:
The two-stage combustion process creates periodic gas generation: the first combustion chamber provides initial controlled gas generation, followed by the second combustion chamber. This periodic action allows the airbag to deploy smoothly while maintaining pressure, avoiding sudden large-volume gas release that would harm occupants
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 design enables adjustable and reproducible output performance, ensuring rapid airbag deployment and maintaining deployment pressure, while minimizing initial impact on occupants by controlling gas generation stages.
Implementation Method 1
a first combustion chamber (30) charged with a first gas generating agent (32)... a second combustion chamber (40) charged with a second gas generating agent (42)... the first gas generating agent (32) located in the first combustion chamber (30) to be burn up earlier than the second gas generating agent (42) located in the second combustion chamber (40)
Data Source
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AI summary
The present invention provides a gas generator including: • a housing (13) including an inner cylindrical member (24) for defining an ignition chamber (19) therein, • a first combustion chamber (30) and a second combustion chamber (40) provided outside the inner cylindrical member and being charged with the first and second gas generating agents (32,42), respectively, • a plenum chamber (50) located between the first combustion chamber and the second combustion chamber and being defined by the partition member, • a first communication nozzle (80) and a second communication nozzle (82) provided in the inner cylindrical member, • an axial position of the first communication nozzle being adjusted to be farther away from the plenum chamber than an axial position of the second communication nozzle, a first gas generating agent to be burn up earlier than a second gas generating agent.