Gas Generator Annular Retainer Prevents Gas Short-Passing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas generators for airbag systems face issues with combustion gas short-passing due to deformation of the housing during actuation, leading to incomplete filtration of combustion products.
Innovation Solution
The design incorporates a housing with gas discharge ports, a cylindrical filter, and an annular retainer with specific geometric relationships to prevent short-passing by maintaining the annular retainer's position against the housing and filter even during deformation, ensuring combustion gases pass through the filter for discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the housing is allowed to deform during actuation, then the structural flexibility is improved, but combustion gas short-passing occurs leading to incomplete filtration
Solution Approach 1:
The annular retainer acts as an intermediary component between the housing and the cylindrical filter. It maintains the filter's positional stability relative to the housing during actuation, preventing combustion gas from short-passing through gaps that would form due to housing deformation. The retainer's abutment surfaces ensure continuous contact and sealing without constraining the overall structural flexibility of the housing.
2Reliability
If the annular retainer is positioned to prevent short-passing, then filtration reliability is improved, but the device complexity increases
Solution Approach 1:
The annular retainer is designed with a simple, thin-walled structure that provides sufficient mechanical function without adding significant complexity. Its geometry allows it to maintain the filter position through basic abutment contacts rather than requiring complex fastening mechanisms or multiple components.
Solution Approach 2:
The annular retainer serves multiple functions simultaneously: it maintains the cylindrical filter's position, prevents combustion gas short-passing, and accommodates housing deformation. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity.
3Ease of manufacture
If the flange and annular base portion are overlapped, then the manufacturing ease is improved, but combustion gas short-passing occurs during actuation
Solution Approach 1:
The solution moves the overlapping relationship from the radial dimension to the axial dimension. The flange and annular base portion are arranged such that they overlap when viewed from the axial direction, rather than overlapping radially. This dimensional repositioning maintains manufacturing simplicity while preventing radial gaps that would cause gas short-passing during actuation.
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 configuration effectively prevents combustion gas short-passing, ensuring complete filtration and maintaining the structural integrity of the gas generator during actuation, ensuring reliable gas supply for airbag systems and similar applications.
Implementation Method 1
a cylindrical filter being disposed to be spaced apart from the gas discharge ports of the circumferential wall of the housing
Implementation Method 2
an ignition device chamber being formed inside a cup-shaped ignition device chamber housing fitted to the cylindrical wall of the bottom plate of the housing from the outside, and accommodating an ignition device including an igniter
Data Source
AI summary
The present invention provides a gas generator includinga housing having a circumferential wall provided with gas discharge ports,a cylindrical filter being disposed inside the housingan ignition device chamber being formed inside a cup-shaped ignition device chamber housing fitted to the cylindrical wall of the bottom plate of the housing, and accommodating an ignition device,a combustion chamber being located between the cylindrical filter and the ignition device chamber housing and being charged with a gas generating agent,the ignition device chamber housing having a flange at an opening thereof and being fitted to the cylindrical wall such that the flange is abutted against the bottom plate,an annular retainer being disposed between the cylindrical filter and the ignition device chamber housing and having an annular base portion and an annular wall extending from an outer circumferential edge of the annular base portion toward the top plate, andthe annular wall being abutted against an inner circumferential surface of the cylindrical filter, the annular base portion being abutted against the bottom plate of the housing, and the annular base portion and the flange of the cup-shaped ignition device chamber housing not being overlapped in a thickness direction.