Patent ID: 8424909

Claim:
A gas generator for a restraining device of a vehicle, comprising: a housing formed by a cup-shaped closure shell, a cup-shaped diffuser shell having a plurality of gas discharge ports on a side surface portion thereof, and a flange portion having a hole for fixing the gas generator; a cup-shaped inner tube member disposed inside the housing, defining therein an ignition device chamber for accommodating an igniter coaxially with a central axis of the housing, and defining, in an outside thereof, a combustion chamber charged with a gas generating agent; the cup-shaped inner tube member having a bottom surface located adjacent to a bottom plate side of the diffuser shell, an opening portion located adjacent to a bottom plate of the closure shell and a first cutout portion formed at an end portion of the opening portion, for allowing a combustion product generated in the ignition device chamber to pass therethrough; the igniter attached to the closure shell such that the igniter projects inside from a hole formed in the bottom plate of the closure shell; the cup-shaped inner tube member fixed to an igniter attaching portion which is a cylindrical portion projecting inwardly, and a passage for a combustion product formed between the cup-shaped inner tube member and the igniter attaching portion to reach the first cutout portion; the combustion chamber having an outer circumferential surface formed by an outer circumference cylindrical member, an inner circumferential surface formed by the inner tube member, a bottom surface formed by the bottom plate of the closure shell, and a top surface formed by an annular porous member provided between the outer circumferential surface and the inner circumferential surface and including an annular bottom plate having a plurality of holes and an inside wall formed at an inner circumferential rim of the annular bottom plate; a gas discharge path formed between the outer circumference cylindrical member and a side surface of the diffuser shell; one end of an opening portion of the outer circumference cylindrical member being located at the bottom plate of the closure shell, a rim of the other end opening portion of the outer circumference cylindrical member having a second cutout portion for communicating the combustion chamber with the gas discharge path and a section having no openings; and the annular porous member disposed such that a space is formed between the annular porous member and the bottom plate of the diffuser shell; wherein no means for cooling and filtering a gas generated by combustion of the gas generating agent is provided other than the annular porous member.