Gas generator with automatic firing function

Abstract

A gas generator for an air bag which includes a gas generating agent having an automatic igniting function is provided. Since a gas generating agent 9b stored in a second combustion chamber 5b has an automatic igniting function, the gas generating agent 9b automatically ignites in case of a vehicle fire, which is accompanied by the combustion of the gas generating agent 9a and the transfer charge 16a and 16b.

Description

TECHNICAL FIELD TO WHICH THE INVENTION BELONGS[0001] The present invention relates to a gas generator for an air bag in which a gas generating agent has an automatic igniting function so that it is unnecessary to use a material having an automatic igniting function separately.PRIOR ART[0002] An air bag system which is mounted on various kinds of vehicles and the like including automobiles, aims to hold a passenger by means of an air bag (a bag body) rapidly inflated by a gas when the vehicle collides at a high speed so as to prevent the passenger from crashing into a hard portion inside the vehicle such as a steering wheel, a windshield due to an inertia and from getting injured. Such an air bag system generally comprises a gas generator which is actuated due to a collision of the vehicle to burn a gas generating agent and discharge a gas, and an air bag in which the gas is introduced to be inflated. The gas generating agent in this gas generator is burnt directly or through combust...

AI Technical Summary

Benefits of technology

[0006] An object of the present invention is to provide a gas generator for an air bag which can secure a safety in such an emergency situation as a vehicle fire while maintaining an automatic igniting function even after a long term elapsed and in which a weight is reduced and a manufacturing cost isi restricted can be achieved.

[0013] The gas generator for an air bag of the present invention can be enhanced in safety and reliability because the gas generating agent has the automatic igniting function and the function is not deteriorated for a long term.

Problems solved by technology

Therefore, in case that the ambient temperature of the gas generator rises to a temperature equal to or more than an ignition temperature of the gas generating agent, there is a risk such that the gas generating agent ignites and burns (explodes).

Thereafter, when the gas generating agent explodes, there is a risk such that the outer shell container is broken and scattered by an explosive pressure so that a human body may be injured.

However, since nitrocellulose has a poor thermal stability, there is a possibility that it is decomposed and degraded while a long term elapses (indicating the life of a vehicle which will be normally between several years to ten and some years), so that the automatic igniting function does not develop.

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