Gas generator

Abstract

The present invention provides a gas generator including a combustion chamber cup which is disposed in the housing provided with a gas discharge port and includes a combination of a cup member and a cylindrical member, a combustion chamber being separated by the combustion chamber cup into an inner combustion chamber and an outer combustion chamber, the cup member having, in a circumferential wall surface thereof, a dropout-preventing slit formed in an axial direction from a first end on the side of a bottom surface to a second end on the side of an opening and a plurality of through holes formed in a circumferential direction, the cylindrical member having a first end opening fixed to a bottom plate of the housing and a protrusion protruding radially outward in a circumferential wall surface thereof, the cup member covering a second end opening of the cylindrical member, and the bottom surface of the cup member being positioned on the side of a top plate of the housing, the plurality of the through holes being closed when the protrusion of the cylindrical member is fitted at the first end of the dropout-preventing slit, at the time of actuation, the plurality of the through holes of the cup member being opened when the cup member moves until the protrusion, which has located at the first end of the dropout-preventing slit, abuts against the second end.