Gas generator

A gas generator comprising,

• a cylindrical housing having a first end whose opening is fixed with an ignition device, and a closed second end on an axially opposite side of the first end, the cylindrical housing including an ignition device chamber provided with the ignition device, a gas inflow chamber having a gas discharge port, and a pressurized gas chamber,
• the ignition device chamber, the gas inflow chamber and the pressurized gas chamber being arranged in the cylindrical housing, in the above order from the first end,
• an inner circumferential wall surface of the cylindrical housing from the ignition device chamber to the gas inflow chamber, having a first movement restricting portion, a second movement restricting portion and a stopping portion which are arranged in an axial direction at intervals in the above order so as to protrude,
• the second movement restricting portion having an ignition device chamber-side surface which is an inclined surface decreasing an inner diameter of the housing from the side of the ignition device chamber to the side of the gas inflow chamber and a gas inflow chamber-side surface whose angle (al) with respect to the cylindrical housing is not more than 90 degrees, so that an axial cross-sectional shape of the second movement restricting portion is a triangle,
• a closing means closing between the pressurized gas chamber and the gas inflow chamber, the closing means including,
• a fixing portion extended radially inward from the inner circumferential wall surface of the cylindrical housing and
• a rupturable plate fixed to the fixing portion, and
• a breaking device for the rupturable plate being arranged between the ignition device chamber and the gas inflow chamber, the breaking device including,
• a base whose outer circumferential surface abuts against the inner circumferential wall surface of the cylindrical housing and
• a rod which extends from the base towards the rupturable plate, the rod including a rod main body portion which extends from the base, and an enlarged-diameter portion which has a diameter enlarged radially at a distal end portion of the rod main body portion,
• before actuation, the base of the breaking device being held between the first movement restricting portion and the second movement restricting portion to fix the breaking device,
• after actuation, the base of the breaking device being held between the gas inflow chamber-side surface of the second movement restricting portion whose angle al is not more than 90 degrees and the stopping portion to stop movement of the breaking device towards both sides in the axial direction.