Gas generator for restraining device of vehicle

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;
• 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;
• no filter for cooling and filtering a gas generated by combustion of the gas generating agent;
• the cup-shaped inner tube member having a bottom surface located in a bottom plate side of the diffuser shell, an opening portion located in a bottom plate of the closure shell and a ventilating 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 ventilating 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 a an annular porous member provided between the outer circumferential surface and the inner circumferential surface;
• one end of an opening portion of the outer circumference cylindrical member located at the bottom plate of the closure shell;
• the annular porous member having a plurality of holes and disposed such that a space is formed between the annular porous member and the bottom plate of the diffuser shell;
• a gas discharge path formed between the outer circumference cylindrical member and a side surface of the diffuser shell;
• and
• the space and the gas discharge path being communicated with each other by a communicating portion formed on the other end of the opening portion of the outer circumference cylindrical member.