Gas Generator Igniter Assembly Fixing Without Welding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods of fixing igniter assemblies in gas generators using welding can cause thermal deformation of the resin portion and combustion of the ignition agent, and they do not provide a strong enough connection without the risk of heat-induced issues.
Innovation Solution
The igniter assembly is fixed to the housing using a holder with concave and convex portions that engage without welding, utilizing elastic hook portions to apply pressure and enhance the fixing strength, allowing for a secure attachment without the need for welding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If welding method is used to fix igniter assembly to housing, then fixing strength is improved, but thermal deformation of resin portion and combustion of ignition agent occur
Solution Approach 1:
The patent replaces the welding method (thermal/mechanical system) with a mechanical insertion system. The holder is inserted into the holder accommodation space and fixed through engagement between convex and concave portions, eliminating the need for welding and thus preventing thermal deformation and combustion of the ignition agent while still providing sufficient fixing strength.
2Object-affected harmful factors
If non-welding fixation method is used, then thermal deformation and combustion are prevented, but fixing strength is insufficient
Solution Approach 1:
The patent employs a composite structure combining the holder (made of resin or elastic material) and the holder accommodation space (formed in the metal member of the igniter assembly). The engagement between the convex portions of the holder and concave portions of the accommodation space creates a strong mechanical connection without welding, providing sufficient fixing strength while avoiding thermal damage.
3Strength
If holder with elastic hook portions is used, then fixing strength is enhanced, but device complexity increases
Solution Approach 1:
The patent utilizes a change in the physical state of the holder material from a compressed state to an expanded state. The elastic hook portions are compressed during insertion and then expand to engage with the holder accommodation space, creating a strong fixing connection. This parameter change (from compressed to expanded) provides enhanced fixing strength without requiring complex additional components.
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 method prevents thermal deformation and combustion of the ignition agent, while providing a strong and reliable connection for both single-type and dual-type gas generators, simplifying the assembly process and increasing the fixing strength of the igniter assembly.
Implementation Method 1
utilizing elastic hook portions to apply pressure and enhance the fixing strength
Data Source
AI summary
A gas generator includes, a housing having a gas discharge port; at least one combustion chamber accommodating a gas generating agent therein; a cylindrical filter disposed between the gas discharge port and the combustion chamber; and at least one ignition device for igniting and combusting the gas generating agent, each device comprising an igniter assembly in which an electric igniter is enclosed and fixed by a metal member and a resin portion. The igniter assembly has, in the resin portion, a holder accommodation space disposed over an opening formed in a bottom portion of the housing, and fixed by a holder inserted from the outside into the opening. An inner wall surface of the holder accommodation space has concave and convex portions that engage convex and concave portions of the holder, so that the igniter assembly is fixed without being welded to the bottom portion of the housing.