Pyrotechnic gas generator, especially for motor vehicle air bag

摘要

A gas generator (1) comprises a hollow cylinder (2), closed at both ends, having at least one discharge port (10) closed by a flap seal (11), and a pyrotechnic igniter (6) fixed to one end. The cylinder contains a piston (17) which has at least one through-channel (22) closed by a flap valve (23) and separates a combustion chamber containing the igniter (6) and the port(s) (10) from a reservoir chamber (16) closed by a cap (4). The piston is able to move axially inside the cylinder as a result of an increase in pressure in the combustion chamber. The combustion chamber contains a mixture of an inert gas and a gas which oxidises under pressure, e.g. argon and oxygen, while the reservoir chamber contains a liquid reducing agent selected from the group comprising azidoalkanes, azidoethers, azidonitriles or azoalkane azides. The igniter is an electric igniter reinforced by an ignition powder.