Gas generator

• US 7,883,111 B2
• Filed: 11/29/2005
• Issued: 02/08/2011
• Est. Priority Date: 12/08/2004
• Status: Expired due to Fees

• Current Assignee: Autoliv AB (Autoliv Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Lehniger, Peter, Gaertner, Jochem, Blessing, Uwe, Winterhalder, Marc Alexander
• Primary Examiner(s): Chambers; Troy
• Application Number:
  US11/288,955
• Publication Number:
  US 20060117982A1
• Time in Patent Office: 1,897 Days
• Field of Search: 102/530, 2807281-741
• US Class Current: 280/741
• 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 relates to a gas generator, in particular for airbag modules in motor vehicles, comprising two generator stages each of which includes in its pressure housing at least one igniter, at least one propellant charge and at least one combustion chamber. An inner generator stage is arranged at least substantially inside an outer generator stage and the two generator stages are arranged at least partly in a common filter housing together with a common filter unit arranged outside a pressure housing of the outer generator stage.

Claims

1. A gas generator for generating an inflation gas for an inflatable cushion in a vehicle, comprising:

an outer pressure stage comprising an outer pressure housing defining an outer combustion chamber and an outer outflow opening, an outer propellant charge disposed within the outer combustion chamber and an outer charge igniter effective to ignite said outer propellant charge;

an inner pressure stage comprising an inner pressure housing disposed within the outer pressure housing and defining an inner combustion chamber and an inner outflow opening communicating said inner combustion chamber to the outer combustion chamber, an inner propellant charge disposed within the inner combustion chamber and an inner charge igniter effective to ignite said inner propellant charge;

a filter housing disposed about the outer pressure housing and having a filter outflow opening; and

a filter disposed between the outer pressure housing and the filter housing for filtering gas flowing from the outer outflow opening to the filter outflow opening,

wherein the gas generator further comprises an outer chamber compensation piece and an inner chamber compensation piece, said outer chamber compensation piece being disposed within the outer combustion chamber opposite the outer charge igniter, and the inner chamber compensation piece being disposed within the inner combustion chamber opposite the inner charge igniter.

2. The gas generator in accordance with claim 1, wherein the outer pressure housing is cylindrical about an axis, and the outer charge igniter and the inner charge igniter are arranged symmetrically about the axis.

3. The gas generator in accordance with claim 2, wherein the outer pressure housing comprises a plurality of outer outflow openings disposed in a radial pattern.

4. The gas generator in accordance with claim 1, wherein the filter housing is ring shaped about the outer pressure housing.

5. The gas generator in accordance with claim 1, wherein the gas generator further comprises a collection grating disposed in the outer combustion chamber between the inner pressure housing and the outer pressure housing.

6. The gas generator in accordance with claim 1, further comprising a base plate, said base plate cooperating with the outer pressure housing to define the outer combustion chamber and the inner pressure housing to define the inner combustion chamber, said outer charge igniter and said inner charge igniter being mounted to said base plate.

7. The gas generator in accordance with claim 6, wherein the filter housing is disposed about the outer pressure housing and the base plate.

8. The gas generator in accordance with claim 7, wherein the filter outflow opening is spaced apart from the base plate, and the outer outflow opening is adjacent the base plate.

9. The gas generator in accordance with claim 8, wherein the inner outflow opening is spaced apart from the base plate.

10. The gas generator in accordance with claim 1, wherein the filter housing comprises a securing flange for attaching the gas generator to an air bag module.

11. The gas generator in accordance with claim 1, wherein the inner pressure stage comprises an insulating film affixed to an interior surface of the inner pressure housing and overlying the inner outflow opening , and a reverse flow protection affixed to an exterior surface of the inner pressure housing and overlying the inner outflow opening.

12. The gas generator in accordance with claim 1, said outer pressure stage further comprising an insulating film affixed to an interior surface of the outer pressure housing and overlying the outer outflow opening.

13. The gas generator in accordance with claim 1, wherein the inner pressure housing comprises a plurality of inner outflow openings.

14. A gas generator for generating an inflation gas for an inflatable cushion in a vehicle, comprising:

an outer pressure stage comprising an outer pressure housing defining an outer combustion chamber and an outer outflow opening, an outer propellant charge disposed within the outer combustion chamber and an outer charge igniter effective to ignite said outer propellant charge;

an inner pressure stage comprising an inner pressure housing disposed within the outer pressure housing and defining an inner combustion chamber and an inner outflow opening communicating said inner combustion chamber to the outer combustion chamber, an inner propellant charge disposed within the inner combustion chamber and an inner charge igniter effective to ignite said inner propellant charge;

a filter housing disposed about the outer pressure housing and having a filter outflow opening; and

a filter disposed between the outer pressure housing and the filter housing for filtering gas flowing from the outer outflow opening to the filter outflow opening,

wherein the inner pressure stage comprises an insulating film affixed to an interior surface of the inner pressure housing and overlying the inner outflow opening, and a reverse flow protection affixed to an exterior surface of the inner pressure housing and overlying the inner outflow opening.

15. The gas generator in accordance with claim 14, wherein the outer pressure housing is cylindrical about an axis, and the outer charge igniter and the inner charge igniter are arranged symmetrically about the axis.

16. The gas generator in accordance with claim 15, wherein the outer pressure housing comprises a plurality of outer outflow openings disposed in a radial pattern.

17. The gas generator in accordance with claim 14, wherein the filter housing is ring shaped about the outer pressure housing.

18. The gas generator in accordance with claim 14, wherein the gas generator further comprises a collection grating disposed in the outer combustion chamber between the inner pressure housing and the outer pressure housing.

19. The gas generator in accordance with claim 14, wherein the gas generator further comprises an outer chamber compensation piece and an inner chamber compensation piece, said outer chamber compensation piece being disposed within the outer combustion chamber opposite the outer charge igniter, and the inner chamber compensation piece being disposed within the inner combustion chamber opposite the inner charge igniter.

20. The gas generator in accordance with claim 14, further comprising a base plate, said base plate cooperating with the outer pressure housing to define the outer combustion chamber and the inner pressure housing to define the inner combustion chamber, said outer charge igniter and said inner charge igniter being mounted to said base plate.

21. The gas generator in accordance with claim 20, wherein the filter housing is disposed about the outer pressure housing and the base plate.

22. The gas generator in accordance with claim 21, wherein the filter outflow opening is spaced apart from the base plate, and the outer outflow opening is adjacent the base plate.

23. The gas generator in accordance with claim 22, wherein the inner outflow opening is spaced apart from the base plate.

24. The gas generator in accordance with claim 14, wherein the filter housing comprises a securing flange for attaching the gas generator to an air bag module.

25. The gas generator in accordance with claim 14, said outer pressure stage further comprising an insulating film affixed to an interior surface of the outer pressure housing and overlying the outer outflow opening.

26. The gas generator in accordance with claim 14, wherein the inner pressure housing comprises a plurality of inner outflow openings.

27. A gas generator for generating an inflation gas for an inflatable cushion in a vehicle, comprising:

an outer pressure stage comprising an outer pressure housing defining an outer combustion chamber and an outer outflow opening, an outer propellant charge disposed within the outer combustion chamber and an outer charge igniter effective to ignite said outer propellant charge;

an inner pressure stage comprising an inner pressure housing disposed within the outer pressure housing and defining an inner combustion chamber and an inner outflow opening communicating said inner combustion chamber to the outer combustion chamber, an inner propellant charge disposed within the inner combustion chamber and an inner charge igniter effective to ignite said inner propellant charge;

a filter housing disposed about the outer pressure housing and having a filter outflow opening; and

a filter disposed between the outer pressure housing and the filter housing for filtering gas flowing from the outer outflow opening to the filter outflow opening,

said outer pressure stage further comprising an insulating film affixed to an interior surface of the outer pressure housing and overlying the outer outflow opening.

28. The gas generator in accordance with claim 27, wherein the outer pressure housing is cylindrical about an axis, and the outer charge igniter and the inner charge igniter are arranged symmetrically about the axis.

29. The gas generator in accordance with claim 28, wherein the outer pressure housing comprises a plurality of outer outflow openings disposed in a radial pattern.

30. The gas generator in accordance with claim 27, wherein the filter housing is ring shaped about the outer pressure housing.

31. The gas generator in accordance with claim 27, wherein the gas generator further comprises a collection grating disposed in the outer combustion chamber between the inner pressure housing and the outer pressure housing.

32. The gas generator in accordance with claim 27, wherein the gas generator further comprises an outer chamber compensation piece and an inner chamber compensation piece, said outer chamber compensation piece being disposed within the outer combustion chamber opposite the outer charge igniter, and the inner chamber compensation piece being disposed within the inner combustion chamber opposite the inner charge igniter.

33. The gas generator in accordance with claim 27, further comprising a base plate, said base plate cooperating with the outer pressure housing to define the outer combustion chamber and the inner pressure housing to define the inner combustion chamber, said outer charge igniter and said inner charge igniter being mounted to said base plate.

34. The gas generator in accordance with claim 33, wherein the filter housing is disposed about the outer pressure housing and the base plate.

35. The gas generator in accordance with claim 34, wherein the filter outflow opening is spaced apart from the base plate, and the outer outflow opening is adjacent the base plate.

36. The gas generator in accordance with claim 35, wherein the inner outflow opening is spaced apart from the base plate.

37. The gas generator in accordance with claim 27, wherein the filter housing comprises a securing flange for attaching the gas generator to an air bag module.

38. The gas generator in accordance with claim 27, wherein the inner pressure stage comprises an insulating film affixed to an interior surface of the inner pressure housing and overlying the inner outflow opening, and a reverse flow protection affixed to an exterior surface of the inner pressure housing and overlying the inner outflow opening.

39. The gas generator in accordance with claim 27, wherein the inner pressure housing comprises a plurality of inner outflow openings.