Welded Gas Generator Sealing to Limit Moisture Ingress

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Solution Overview

Problem

Existing gas generators face issues with moisture absorption of the gas generating agent due to multiple air paths, leading to deterioration and increased assembly complexity due to the need for additional parts like O-rings or sealing materials.

Innovation Solution

A gas generator design with a housing that includes an activation gas generation chamber and a filter chamber, using a side surface cover welded to the housing and holder to restrict air passages, reducing the need for additional sealing components and simplifying assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If multiple air paths are provided between the internal space and outside of the housing, then ventilation is improved, but moisture absorption of the gas generating agent increases leading to deterioration

Engineering Contradiction:
ImproveventilationVSAvoidmoisture absorption resistance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The invention extracts the sealing function from separate components (O-rings, sealing materials) and integrates it into the holder structure itself. The holder is designed with a sealed configuration that directly prevents air passage between the internal space and outside, eliminating the need for additional sealing parts while maintaining moisture protection.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention merges the sealing function with the holder structure. Instead of having separate sealing components, the holder is designed to provide both structural support and sealing functionality through its integrated configuration, reducing the number of parts while effectively preventing moisture absorption.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If O-rings or sealing materials are used to suppress moisture absorption, then moisture protection is improved, but the number of parts increases and assembly complexity increases

Engineering Contradiction:
Improvemoisture absorption resistanceVSAvoidnumber of parts
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention merges the sealing function with the holder structure. Instead of having separate sealing components, the holder is designed to provide both structural support and sealing functionality through its integrated configuration, reducing the number of parts while effectively preventing moisture absorption.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention extracts the sealing function from separate components (O-rings, sealing materials) and integrates it into the holder structure itself. The holder is designed with a sealed configuration that directly prevents air passage between the internal space and outside, eliminating the need for additional sealing parts while maintaining moisture protection.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If O-rings or sealing materials are used to suppress moisture absorption, then moisture protection is improved, but assembly process complexity increases

Engineering Contradiction:
Improvemoisture absorption resistanceVSAvoidassembly process simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention merges the sealing function with the holder structure. Instead of having separate sealing components, the holder is designed to provide both structural support and sealing functionality through its integrated configuration, reducing the number of parts while effectively preventing moisture absorption.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention extracts the sealing function from separate components (O-rings, sealing materials) and integrates it into the holder structure itself. The holder is designed with a sealed configuration that directly prevents air passage between the internal space and outside, eliminating the need for additional sealing parts while maintaining moisture protection.

Inventive Principle:
Principle #2Taking out (Extraction)

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 effectively suppresses moisture absorption of the gas generating agent and reduces the number of parts, making assembly easier while maintaining functionality.

Implementation Method 1

an activation gas generation chamber in which an activation gas is generated by combustion of a gas generating agent

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 2

at least a portion of the housing at a position corresponding to the side surface of the first forming portion covered with the side surface cover, a portion of the side surface cover corresponding to the portion, and a portion of a side surface of the holder corresponding to the portion are subjected to welding fixation annularly along a circumferential direction of the housing

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP4578744A1Gas generator
Publication Date: 2025.07.02 NIPPON KAYAKU CO LTD
  • EP4578744A1 patent drawingFigure 1
  • EP4578744A1 patent drawingFigure 2
  • EP4578744A1 patent drawingFigure 3

AI summary

There is obtained a gas generator that can suppress deterioration due to moisture absorption of a gas generating agent in a housing, can reduce the number of parts, and can be easily assembled as compared with the related art. A gas generator 100 includes a housing 10, a holder 20 attached to one opening end of the housing 10, a closing member 12 attached to another end of the housing 10 so as to close another opening end of the housing 10, and a side surface cover 51 covering a part of the holder 20 and a part of an igniter 50. The side surface cover 51 has an end welded and fixed to the housing 10 and the holder 20 at a welded fixed portion 62 in a state of being sandwiched between an inner wall of the housing 10 and a side surface portion 22. The welded fixed portion 62 is formed in an annular shape along the circumferential direction of the housing 10 by being subjected to welding processing from the outside of the housing 10 along a circumferential direction of the housing 10 at a position corresponding to the side surface portion 22 covered by the side surface cover 51.