Multi-Stage Gas Generator Combustion Chamber Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multi-stage inflators for vehicle occupant restraint systems have complex and expensive assemblies due to separate combustion chamber elements and igniter components, requiring a simplified and cost-effective design with enhanced mechanical structure.
Innovation Solution
A multi-stage inflator design featuring a diffuser bowl with outflow openings and a cover, where the diffuser bowl and/or cover form the inner wall of the combustion chambers, eliminating the need for separate sleeve-shaped components and allowing for a simplified geometry and reduced load distribution, with igniter devices mounted directly to housing parts via plastic injection molding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate sleeve-shaped components and igniter carriers are used to form combustion chambers, then the inflator can achieve multi-stage combustion functionality, but the assembly becomes complicated and expensive
Solution Approach 1:
The patent merges the functions of separate combustion chamber elements, igniter sleeves, and igniter carriers into an integrated housing structure. The housing itself forms the combustion chambers through its geometric design, eliminating the need for multiple separate components while maintaining multi-stage combustion capability.
Solution Approach 2:
The housing structure serves multiple functions simultaneously: it provides structural support, defines the combustion chamber geometry, and integrates igniter mounting features. This multi-functional design reduces component count while maintaining all necessary combustion functions.
2Adaptability or versatility
If separate sleeve-shaped components are used to form combustion chambers, then the inflator can achieve multi-stage combustion, but the manufacturing and assembly cost increases
Solution Approach 1:
The patent combines multiple functions into the housing structure itself, which forms combustion chambers through its geometric design rather than requiring separate sleeve components. This integration simplifies manufacturing processes and reduces assembly costs while maintaining multi-stage combustion capability.
3Ease of manufacture
If housing shells are used to form combustion chambers, then the outer housing can be manufactured simply and inexpensively, but the mechanical load-bearing capacity may be insufficient
Solution Approach 1:
The patent employs a composite construction where a plastic housing provides the outer structure and combustion chamber geometry, while integrated tie rods provide additional mechanical reinforcement. This combination maintains manufacturing simplicity while significantly enhancing load-bearing capacity.
Solution Approach 2:
The housing incorporates curved, diffuser-bowl-shaped structures that naturally distribute mechanical loads more effectively than flat surfaces. The geometric curvature provides structural reinforcement while maintaining the simple molded construction approach.
4Adaptability or versatility
If the inflator uses multiple separate components for combustion chambers, then combustion functionality is achieved, but the overall weight increases
Solution Approach 1:
The patent integrates multiple combustion chamber functions into a single housing structure, eliminating the weight of separate sleeve components and igniter carriers. The housing itself defines the combustion chambers through its geometry, reducing overall component mass.
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 design results in a more affordable, lightweight, and robust inflator with independent ignition and dosing capabilities, reducing component loads and simplifying manufacturing, while maintaining effective gas discharge and igniter protection.
Implementation Method 1
The diffuser bowl and/or the cover include a section that is reshaped, in particular deep-drawn, into an indentation forming at least partially a circumferential section of the inner wall
Implementation Method 2
The housing parts are preferably interconnected by welding, the welds being located especially on the curves
Data Source
AI summary
A gas generator (10) comprises an outer housing, which has at (east two housing parts (12), which are connected to each other, in the form of a diffuser bowl (14) with outflow openings (16) towards the outside and a cover (20) directly connected to the diffuser bowl (14). Inside the gas generator (10), at least one first and one second combustion chamber (30, 36) are provided, wherein the first combustion chamber (30) is delimited by an inner wall (32) and the second combustion chamber (36) is located within the space delimited by the diffuser bowl (14) and the cover (20). The diffuser bowl (14) and/or the cover (20) comprise a section (24) that is shaped, in particular deep-drawn, into an indentation, forming at least partially a circumferential section of the inner wall (32).