Gas generator
There is obtained a gas generator that can suppress deterioration due to moisture absorption of a gas generating agent in a housing, can reduce the number of parts, and can be easily assembled as compared with the related art. A gas generator includes a housing, a holder attached to one opening end of the housing, a closing member attached to another end of the housing so as to close another opening end of the housing, and a side surface cover covering a part of the holder and a part of an igniter. The side surface cover has an end welded and fixed to the housing and the holder at a welded fixed portion in a state of being sandwiched between an inner wall of the housing and a side surface portion. The welded fixed portion is formed in an annular shape along the circumferential direction of the housing by being subjected to welding processing from the outside of the housing along a circumferential direction of the housing at a position corresponding to the side surface portion covered by the side surface cover.
1 . A gas generator comprising:
a housing having an elongated cylindrical shape extending in an axial direction and including, inside of the housing,
an activation gas generation chamber in which an activation gas is generated by combustion of a gas generating agent, and
a filter chamber in which a filter through which the activation gas generated in the activation gas generation chamber passes is accommodated;
a gas generating agent ignition unit that encloses an ignition charge, is disposed at one end in the axial direction of the housing, and allows the gas generating agent to be ignited and combusted in the activation gas generation chamber; and
a holder fixed to the one end in the axial direction of the housing and including
a first holder portion having a substantially tubular shape and defining a keeper that keeps the gas generating agent ignition unit on an inner side of the housing, and
a second holder portion having a substantially tubular shape, integrally provided with the first forming portion on a side of the first holder portion opposite to the activation gas generation chamber, and defining a connector fitting portion configured to be fitted with a connector for energizing the gas generating agent ignition unit on an opposite side of a keeping position of the gas generating agent ignition unit; and
a side surface cover that is a bottomed tubular member defining a tubular cover portion,
wherein the side surface cover is configured to cover at least a part of the gas generating agent ignition unit facing the activation gas generation chamber and at least a part of a side surface of the first holder portion,
in a radial direction perpendicular to the axial direction of the housing, the tubular cover portion is sandwiched between an inner wall of the housing and the side surface of the first holder portion to form radially overlapping portions of the housing, the tubular cover portion, and the side surface of the first holder portion which overlap each other in the radial direction, and
the radially overlapping portions of the housing, the tubular cover portion, and the side surface of the first holder portion are fixed together by an annular welding fixation extending annularly along a circumferential direction of the housing.
2 . The gas generator according to claim 1 , wherein
in the axial direction of the housing, the side surface cover has a first end directed toward the holder and a second end directed toward the activation gas generation chamber, and
the welding fixation coincides with the first end of the side surface cover.
3 . The gas generator according to claim 1 , wherein
in the axial direction of the housing, the side surface cover has a first end directed toward the holder and a second end directed toward the activation gas generation chamber, and
the second end of the side surface cover is provided with
a bottom surface, and
a tapered portion that is connected to the bottom surface and reduces in diameter toward another end in the axial direction of the housing.
4 . The gas generator according to claim 2 , wherein
the second end of the side surface cover is provided with
a bottom surface, and
a tapered portion that is connected to the bottom surface and reduces in diameter toward another end in the axial direction of the housing.
5 . The gas generator according to claim 2 , wherein
in the axial direction of the housing, the first end of the side surface cover aligns with the one end of the housing, and
the welding fixation coincides with the first end of the side surface cover and the one end of the housing.
6 . The gas generator according to claim 5 , wherein
the holder includes an annular surface defined where the second holder portion extends outward from the side surface of the first holder portion in the radial direction, and
the welding fixation coincides with the first end of the side surface cover, the one end of the housing, and the annular surface of the holder.