Gas generator

A gas generator, comprising:

• an outer container formed by a pressurized gas bottle, which forms a pressurized gas chamber filled with a pressurized gas, and a cylindrical gas generation chamber housing;
• a closing member closing between the pressurized gas bottle and the gas generation chamber housing;
• the gas generation chamber housing having,
• a gas generation chamber accommodating therein an ignition device and a gas generating agent,
• a gas inflow chamber, arranged between the pressurized gas chamber and the gas generation chamber for introducing a combustion gas flowing out of the gas generation chamber and a pressurized gas flowing out of the pressurized gas chamber, and
• a partition wall separating the gas generation chamber from the gas inflow chamber and being provided with a rupturing member for breaking through the closing member;
• the gas inflow chamber having
• a gas discharge port, and
• a step portion or a protrusion formed on a side of the gas generation chamber housing between the gas generation chamber and the gas discharge port,
• the partition wall,
• having a communication hole that communicates between the gas generation chamber and the gas inflow chamber,
• having an outer circumferential edge surface abutting against an inner circumferential wall surface of the outer container, so as to be movable in an axial direction, and
• facing directly the closing member at a distance therefrom;
• the rupturing member,
• having an outer diameter smaller than an inner diameter of an opening closed by the closing member, and
• being formed at the partition wall so as to face directly the closing member at a distance therefrom;
• at a time of actuation,
• the partition wall, provided with the rupturing member, being stopped by the outer circumferential edge surface thereof colliding with the step portion or the protrusion formed in the gas inflow chamber after moving in the axial direction while reducing a volume of the gas inflow chamber, and the rupturing member breaking through the closing member to open a gas discharge path from the pressurized gas chamber to the gas inflow chamber;
• and
• the combustion gas which is generated from the gas generation chamber and the pressurized gas which flows out of the pressurized gas chamber, passing through the gas inflow chamber with the decreased volume and being discharged from the gas discharge port.