Gas generator
The present invention provides a gas generator in which an effect of decreasing the temperature of a combustion gas and an effect of capturing mist of the combustion gas are adjusted. A cup member disposed in a cylindrical housing has one gas passage hole selected from a first gas passage hole, which is formed in part of a circumferential wall on the side of an opening, a second gas passage hole, which is formed in part of a circumferential wall on the side of a bottom portion, and a third gas passage hole, which is formed between the first gas passage hole and the second gas passage hole. By selecting one of the above gas passage holes, the effect of decreasing the temperature of the combustion gas and the effect of capturing mist of the combustion gas are adjusted.
1. A gas generator comprising
a cylindrical housing in which an ignition device is attached at a first end portion and a diffuser portion having a gas discharge port is attached at a second end portion on the opposite side of the first end portion,
a combustion chamber, which is formed on the side of the ignition device, and a cup member, which serves as a gas diverting member and is disposed between the combustion chamber and the diffuser portion, being provided inside the cylindrical housing,
a ratio (L 2 /L 1 ) of a length (L 2 ) of the cup member serving as the gas diverting member and a length (L 1 ) of the cylindrical housing being 0.2 to 0.4,
the cup member serving as the gas diverting member being disposed such that a bottom portion is located on the side of the combustion chamber, an opening is located on the side of the diffuser portion and a circumferential wall portion forms a cylindrical space serving as a gas passage with an inner circumferential wall surface of the cylindrical housing therebetween,
the cup member having one gas passage hole selected from:
a first gas passage hole that is formed in part of the circumferential wall portion on the side of the opening and faces the cylindrical space serving as the gas passage;
a second gas passage hole that is formed in part of the circumferential wall portion on the side of the bottom portion and faces the cylindrical space serving as the gas passage; and
a third gas passage hole that is formed between the first gas passage hole and the second gas passage hole and faces the cylindrical space serving as the gas passage,
the cylindrical space serving as the gas passage communicating with the combustion chamber and being closed on the side of the diffuser portion.
2. A gas generator comprising
a cylindrical housing in which an ignition device is attached at a first end portion and a diffuser portion having a gas discharge port is attached at a second end portion on the opposite side of the first end portion,
a combustion chamber, which is formed on the side of the ignition device, and a cup member, which serves as a gas diverting member and is disposed between the combustion chamber and the diffuser portion, being provided inside the cylindrical housing,
a ratio (L 2 /L 1 ) of a length (L 2 ) of the cup member serving as the gas diverting member and a length (L 1 ) of the cylindrical housing being 0.2 to 0.4,
a cylindrical member, which has a plurality of through-holes in a circumferential wall portion, being disposed inside the combustion chamber,
the cylindrical member being disposed such that an opening is located on the side of the ignition device, a bottom portion is located on the side of a bottom portion of the a cup member serving as a gas diverting member, and a circumferential wall portion forms a first cylindrical space serving as a first gas passage with an inner circumferential wall surface of the cylindrical housing therebetween,
the cup member serving as the gas diverting member being disposed such that a bottom portion is located on the side of the combustion chamber, an opening is located on the side of the diffuser portion and a circumferential wall portion forms a second cylindrical space serving as a second gas passage with an inner circumferential wall surface of the cylindrical housing therebetween,
the cup member having one gas passage hole selected from:
a first gas passage hole that is formed in part of the circumferential wall portion on the side of the opening and faces the second cylindrical space serving as the second gas passage;
a second gas passage hole that is formed in part of the circumferential wall portion on the side of the bottom portion and faces the second cylindrical space serving as the second gas passage; and
a third gas passage hole that is formed between the first gas passage hole and the second gas passage hole and faces the second cylindrical space serving as the second gas passage,
the second cylindrical space serving as the second gas passage communicating with the first cylindrical space and being closed on the side of the diffuser portion.
3. The gas generator according to claim 2 , wherein a ratio (L 12 /L 11 ) of a length (L 12 ) of the second cylindrical space serving as the second gas passage and a length (L 11 ) of the first cylindrical space serving as the first gas passage is within a range of 0.40 to 0.60.
4. The gas generator according to claim 1 , wherein
when a length from the opening to the outer surface of the bottom portion in the cup member is taken as 1,
the first gas passage hole is formed within a range of 0.25 from the opening,
the second gas passage hole is formed within a range of 0.75 to 1 from the opening, and
the third gas passage hole is formed within a range of 0.3 to 0.7 from the opening.
5. The gas generator according to claim 1 , wherein
each of the first gas passage hole, the second gas passage hole and the third gas passage hole is formed as two to eight holes arranged equidistantly in the circumferential direction.
6. The gas generator according to claim 1 , wherein
the combustion chamber is divided into two combustion chambers by two porous plate members disposed at a distance from each other.
7. The gas generator according to claim 2 , wherein
when a length from the opening to the outer surface of the bottom portion in the cup member is taken as 1,
the first gas passage hole is formed within a range of 0.25 from the opening,
the second gas passage hole is formed within a range of 0.75 to 1 from the opening, and
the third gas passage hole is formed within a range of 0.3 to 0.7 from the opening.
8. The gas generator according to claim 2 , wherein
each of the first gas passage hole, the second gas passage hole and the third gas passage hole is formed as two to eight holes arranged equidistantly in the circumferential direction.
9. The gas generator according to claim 2 , wherein
the combustion chamber is divided into two combustion chambers by two porous plate members disposed at a distance from each other.