Gas generator for air bag and air bag device

• US 20020190511A1
• Filed: 05/06/2002
• Published: 12/19/2002
• Est. Priority Date: 11/29/1999
• Status: Active Grant

• Current Assignee: Daicel Chemical Industries Limited
• Original Assignee: Daicel Chemical Industries Limited
• Inventors: Yabuta, Mikio, Watase, Takefumi
• Granted Patent: US 6,880,853 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

The present invention provides a gas generator capable of easily and unfailingly closing a gas discharging port formed in a housing. The invention provides a gas generator for an air bag in which 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 invention provides a gas generator which has sealing structures as little as possible and in addition to a simple structure and can be manufactured easily, and in that a activation performance and activation timing can be adjusted at a multiple stage.

The invention provides 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. The invention provides 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 so that these cambers communicate with each other, the combustion chamber accommodating the gas generating means is separated from the filter means accommodating chamber by a partitioning member having a through-hole. The invention provides a gas generator for an air bag comprising, in a cylindrical housing which is longer in the axial direction than in the radial direction, two ignition means to be actuated upon the impact, and two combustion chambers accommodating gas generating means to be ignited and burnt by the ignition means, wherein the combustion chambers are provided on the opposite ends in the housing, a filter means accommodating chamber for accommodating a filter means is provided between the combustion chambers, either of the combustion chambers communicates with the filter means accommodating chamber.

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 or 2, 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 any one of claims 1 to 3, 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 any one of claims 1 to 4, 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 any one of claims 1 to 5, 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 any one of claims 1 to 8, 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 any one of claims 1 to 9, 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,

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

12. A gas generator for an air bag according to claim 11, wherein the cylindrical housing is provided at its peripheral wall with a plurality of gas discharging ports, and moisture-proof of the housing is achieved by a seal tape which closes the gas discharging ports.

13. A gas generator for an air bag according to claim 11 or 12, wherein an inwardly flange-shaped plate member is disposed in the combustion chamber provided in the cylindrical housing, the plate member is fitted into the combustion chamber to be able to slide in the axial direction of the housing, and the gas generating means accommodated in the combustion chamber is pressed and/or held towards the filter means accommodating chamber side.

14. A gas generator for an air bag according to any one of claims 11 to 13, wherein a flame-transferring tube formed at its peripheral wall with a plurality of flame-transferring holes is accommodated in the combustion chamber, 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.

16. A gas generator for an air bag according to claim 15, wherein the cylindrical housing is provided at its peripheral wall with a plurality of gas discharging ports, and moisture-proof of the housing is achieved by a seal tape which closes the gas discharging port.

17. A gas generator for an air bag according to claim 15 or 16, wherein the combustion chamber is separated from the filter means accommodating chamber by a partitioning member having a through-hole.

20. A gas generator for an air bag according to claim 19, wherein the cylindrical housing is provided at its peripheral wall with a plurality of gas discharging ports, and moisture-proof in the housing is achieved by closing the gas discharging ports with a seal tape.

21. A gas generator for an air bag according to claim 19 or 20, wherein the combustion chamber is separated from the filter means accommodating chamber by a partitioning member having a through-hole.

23. A gas generator for an air bag according to any one of claims 11 to 14, 17, 18, 21 and 22, wherein the partition member is curved into a convex shape towards the inside of the combustion chamber.

24. A gas generator for an air bag according to any one of claims 11 to 23, 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 for closing the opening in the combustion chamber side comprises an annular portion connected to an opening edge of the diffuser shell and a cylindrical portion projecting out of the housing, and the ignition means is accommodated inside of the cylindrical portion.

25. A gas generator for an air bag according to any one of claims 11 to 24, 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.

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 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.

18. A gas generator for an air bag according to any one of claims 15 to 17, wherein a flame-transferring tube formed at its peripheral wall with a plurality of flame-transferring holes is accommodated in the combustion chamber, 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 the ignition means is accommodated.

19. 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,

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

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.

22. A gas generator for an air bag according to any one of claims 19 to 21, wherein an inwardly flange-shaped plate member is disposed in the combustion chamber, the plate member is fitted into the combustion chamber to be able to slide in the axial direction of the housing, and the gas generating means accommodated in the combustion chamber is pressed and/or held towards the filter means accommodating chamber side.

26. A gas generator for an air bag according to claim 25, 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.

28. A gas generator for an air bag according to claim 27, wherein the cylindrical housing is provided at its peripheral wall with a plurality of gas discharging ports, and moisture-proof in the combustion chamber communicating with the filter means accommodating chamber is achieved by a seal tape which closes gas discharging port.

29. A gas generator for an air bag according to claim 27 or 28, wherein either one of the two combustion chambers is defined inside of a cup member provided with a plurality of through-holes, the through-hole is closed with a closing member.

30. A gas generator for an air bag according to claim 29, wherein the plurality of through-holes are formed in a peripheral wall of the cup member, and a flow path from the through-holes to the filter means accommodating chamber is formed between an outer peripheral surface of the cup member and an inner peripheral surface of the housing.

31. A gas generator for an air bag according to claim 29 or 30, wherein the closing member is a stainless foil having a thickness of 20 to 80 μ

m.

27. A gas generator for an air bag comprising, in a cylindrical housing which is longer in the axial direction than in the radial direction, two ignition means to be actuated upon the impact and accommodated in the housing, and two combustion chambers accommodating gas generating means to be ignited and burnt by the ignition means, wherein the combustion chambers are provided on the opposite ends in the housing, a filter means accommodating chamber for accommodating filter means is provided between these combustion chambers, and either one of the combustion chambers communicates with the filter means accommodating chamber.

32. A gas generator for an air bag according to any one of claims 27 to 31, wherein an inwardly flange-shaped plate member is disposed in the combustion chamber provided in the cylindrical housing, and the plate member is fitted into the combustion chamber to push and/or hold said gas generating means accommodated in the combustion chamber on the side of the filter means accommodating chamber.

33. A gas generator for an air bag according to any one of claims 27 to 32, 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 comprises an annular portion and a cylindrical portion projecting out of the housing, and the ignition means is accommodated inside the cylindrical portion.

34. A gas generator for an air bag according to any one of claims 27 to 33, wherein at least one of a plurality of the combustion chambers accommodates a flame-transferring tube provided at its peripheral wall with a plurality of flame-transferring holes, the flame-transferring tube extends in the axial direction of the housing, and an end of the tube is connected into the interior of the cylindrical portion of the closure shell where the ignition means is accommodated.

35. A gas generator for an air bag according to any one of claims 27 to 34, wherein the filter means accommodating chamber and the combustion chamber which communicates with the filter means accommodating chamber are separated from each other by a partitioning member having a through-hole.

36. A gas generator for an air bag according to claim 35, wherein the partition member is curved into a convex shape towards the inside of the combustion chamber which communicates with the filter means accommodating chamber.

37. An air bag apparatus comprising

a gas generator for an air bag,

an impact sensor to detect the impact and actuate the gas generator,

an air bag which inflates by introducing, thereinto, gas generated by the gas generator, and

a module case for accommodating the air bag, wherein the gas generator for the air bag is one described in any of claims 27 to 36.