Gas generator for air bag and air bag apparatus

• US 20050029786A1
• Filed: 08/30/2004
• Published: 02/10/2005
• Est. Priority Date: 11/29/1999
• Status: Active Grant

• Current Assignee: Daicel Chemical Industries Limited (Daicel Corporation)
• Original Assignee: Daicel Chemical Industries Limited (Daicel Corporation)
• Inventors: Yabuta, Mikio, Watase, Takefumi
• Granted Patent: US 6,997,475 B2
• Time in Patent Office: Days
• US Class Current: 280/740
• CPC Class Codes: B60R 2021/2633 with a plurality of inflation levels
• CPC Class Codes: B60R 2021/2648 comprising a plurality of combustion chambers or sub-chambers
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder

Abstract

A gas generator for an air bag capable of easily and unfailingly closing a gas discharging port formed in a housing. An amount of accommodated gas generating agent can be varied and the gas generating agent can be ignited and burnt unfailingly even by the ignition means having normal output. The gas generator has sealing structures as small as possible and a simple structure and can be manufactured easily. Activation performance and activation timing can be adjusted at a multiple stage. For instance, the air bag housing may be provided at its peripheral wall with a plurality of gas discharging ports, an ignition means to be actuated upon impact, and a gas generating means to be ignited and burnt by the ignition means, wherein the gas discharging ports are arranged in the axial direction of the housing to form a gas discharging port line. Other configurations are also disclosed.

Claims

1. A gas generator for an air bag comprising, in a housing provided at its peripheral wall with a plurality of gas discharging ports, an ignition means to be actuated upon the impact, and a gas generating means to be ignited and burnt by the ignition means,

wherein the gas discharging ports are arranged in the axial direction of the housing to form a gas discharging port line, two to six gas discharging port lines are arranged close to each other in the circumferential direction of the housing to form a gas discharging port group, the gas discharging port groups are arranged in the circumferential direction of the housing at predetermined intervals.

2. A gas generator for an air bag according to claim 1, wherein the gas discharging port groups are adjusted such that the center angle formed between adjacent gas discharging ports in the circumferential direction of the housing is in the range of 10°

to 30°

.

3. A gas generator for an air bag according to claim 1, wherein the gas discharging port groups are formed at intervals of the center angle of 60°

to 120°

.

4. A gas generator for an air bag according to claim 1, wherein the respective gas discharging port lines constituting a gas discharging port group have the gas discharging ports having different diameters from each other line.

5. A gas generator for an air bag according to claim 1, wherein each of the gas discharging port groups is closed with one strip of a seal tape.

6. A gas generator for an air bag according to claim 1, wherein a width of each of the gas discharging port groups is adjusted to be smaller than a width of said one strip of a seal tape which closes the gas discharging port group by 2 to 20 mm.

9. A gas generator for an air bag according to one of claims 1 or 7, wherein the housing is formed into a cylindrical shape which is longer in the axial direction than in the radial direction.

10. A gas generator for an air bag according to claim 1, wherein a combustion chamber for accommodating the gas generating means and a filter means accommodating chamber for accommodating a filter means are formed in the housing adjacent to each other in the axial direction, and the gas discharging port lines or the gas discharging port groups are formed in a peripheral wall of the housing, in the region where the filter means accommodating chamber is defined inside.

7. A gas generator for an air bag comprising, in a housing provided at its peripheral wall with a plurality of gas discharging ports, an ignition means to be actuated upon the impact, and a gas generating means to be ignited and burnt by the ignition means,

wherein the gas discharging ports are arranged in the axial direction of the housing to form a gas discharging port line, and the gas discharging port lines are arranged at predetermined intervals in the circumferential direction of the housing.

8. A gas generator for an air bag according to claim 7, wherein each of the gas discharging port lines is closed with one strip of a seal tape.

11. A gas generator for an air bag comprising, in a cylindrical housing which is longer in the axial direction than in the radial direction, an ignition means to be actuated upon the impact, and a gas generating means to be ignited and burnt by the ignition means,

wherein a combustion chamber for accommodating the gas generating means and a filter means accommodating chamber for accommodating a filter means are formed in the housing adjacent to each other in the axial direction and these cambers communicates with each other,

wherein the combustion chamber accommodating the gas generating means is separated from the filter means accommodating chamber with a partitioning member having a through-hole, and

wherein the cylindrical housing comprises a cylindrical diffuser shell provided at its peripheral wall with a plurality of gas discharging ports, and closure shells for closing the opposite end openings of the peripheral wall, the closure shell closing the opening in the filter means accommodating chamber side comprises an annular portion connected to an opening edge of the diffuser shell, a circular portion projecting from the annular portion toward the filter means accommodating chamber, and a screw portion projecting from the annular portion out of the housing, and the circular portion abuts against an inner peripheral surface of the filter means to support the filter means.

12. A gas generator for an air bag according to claim 11, wherein a filter supporting member which has an inner peripheral wall of an annular portion projecting into a hollow portion of the filter means and an outer peripheral wall fitted into the housing is disposed on the filter means in the combustion chamber side, and the filter means is supported by and fixed to the inner peripheral wall of the filter means supporting member and the circular portion of the diffuser shell.

13. A gas generator for an air bag comprising, in a cylindrical housing which is longer in the axial direction than in the radial direction, an ignition means to be actuated upon the impact, and a gas generating means to be ignited and burnt by the ignition means,

wherein a combustion chamber for accommodating the gas generating means and a filter means accommodating chamber for accommodating a filter are formed in the housing adjacent to each other in the axial direction, the gas generating means accommodated in the combustion chamber is pressed and/or held towards the filter means accommodating chamber side by an inwardly flange-shaped plate member fitted into the combustion chamber, and the plate member is slidable in the axial direction of the housing, and

wherein the cylindrical housing comprises a cylindrical diffuser shell provided at its peripheral wall with a plurality of gas discharging ports, and closure shells for closing the opposite end openings of the peripheral wall, the closure shell closing the opening in the filter means accommodating chamber side comprises an annular portion connected to an opening edge of the diffuser shell, a circular portion projecting from the annular portion toward the filter means accommodating chamber, and a screw portion projecting from the annular portion out of the housing, and the circular portion abuts against an inner peripheral surface of the filter means to support the filter means.

14. A gas generator for an air bag according to claim 13, wherein a filter supporting member which has an inner peripheral wall of an annular portion projecting into a hollow portion of the filter means and an outer peripheral wall fitted into the housing is disposed on the filter means in the combustion chamber side, and the filter means is supported by and fixed to the inner peripheral wall of the filter means supporting member and the circular portion of the diffuser shell.

15. A gas generator for an air bag comprising, in a cylindrical housing which is longer in the axial direction than in the radial direction, an ignition means to be actuated upon the impact, and a gas generating means to be ignited and burnt by the ignition means,

wherein a combustion chamber for accommodating the gas generating means and a filter means accommodating chamber for accommodating a filter means are formed in the housing adjacent to each other in the axial direction,

wherein a flame-transferring tube formed at its peripheral wall with a plurality of flame-transferring holes is accommodated in the combustion chamber,

wherein the flame-transferring tube extends in the axial direction of the housing, and an end of the tube is connected into an ignition means accommodating chamber in which ignition means is accommodated, and

wherein the cylindrical housing comprises a cylindrical diffuser shell provided at its peripheral wall with a plurality of gas discharging ports, and closure shells for closing the opposite end openings of the peripheral wall, the closure shell closing the opening in the filter means accommodating chamber side comprises an annular portion connected to an opening edge of the diffuser shell, a circular portion projecting from the annular portion toward the filter means accommodating chamber, and a screw portion projecting from the annular portion out of the housing, and the circular portion abuts against an inner peripheral surface of the filter means to support the filter means.

16. A gas generator for an air bag according to claim 15, wherein a filter supporting member which has an inner peripheral wall of an annular portion projecting into a hollow portion of the filter means and an outer peripheral wall fitted into the housing is disposed on the filter means in the combustion chamber side, and the filter means is supported by and fixed to the inner peripheral wall of the filter means supporting member and the circular portion of the diffuser shell.