Gas generator

• US 20060119086A1
• Filed: 11/29/2005
• Published: 06/08/2006
• Est. Priority Date: 12/08/2004
• Status: Active Grant

• Current Assignee: Autoliv AB (Autoliv Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Lehniger, Peter, Gaertner, Jochem, Blessing, Uwe, Winterhalder, Marc Alexander
• Granted Patent: US 7,350,810 B2
• Time in Patent Office: Days
• US Class Current: 280/736
• CPC Class Codes: B60R 2021/26011 using a filter through which the inflation gas passes
• 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 a plurality of separate generator stages which can be ignited independently of one another and each of which includes in its own pressure housing at least one igniter, at least one propellant charge and at least one combustion chamber. The generator stages are arranged at least partly in a common filter housing together with a common filter unit and the space remaining in the filter housing is designed at least regionally as an outflow passage system leading from outflow apertures formed in the pressure housings to the filter unit.

Claims

1. A gas generator, in particular for airbag modules in motor vehicles, having a plurality of separate generator stages which can be ignited independently of one another and each of which includes in its separate pressure housing at least one igniter, at least one propellant charge and at least one combustion chamber,

wherein the generator stages are arranged at least partly in a common filter housing together with a common filter unit,

and the space remaining in the filter housing is made at least regionally as an outflow passage system leading from outflow openings formed in the pressure housings to the filter unit.

2. A gas generator in accordance with claim 1, characterized in that precisely two generator stages of different sizes are provided.

3. A gas generator in accordance with claim 1, characterized in that the individual generator stages are arranged next to one another.

4. A gas generator in accordance with claim 1, characterized in that in cross-section, the generator stages fill the filter housing at least predominantly, with an outer contour of the generator stages being at least regionally complementary to an inner contour of the filter housing.

5. A gas generator in accordance with claim 1, characterized in that two generator stages each having a substantially semi-circular cross-section are arranged in a filter housing having a substantially circular cross-section.

6. A gas generator in accordance with claim 1, characterized in that the generator stages each have a cross-section in the form of a segment of a circle or of a segment of an annulus.

7. A gas generator in accordance with claim 1, characterized in that the generator stages form a closed annulus at whose center a common outflow passage is provided.

8. A gas generator in accordance with claim 1, characterized in that the filter unit is arranged above the outflow openings.

9. A gas generator in accordance with claim 1, characterized in that the filter unit is arranged at least substantially between the generator stages.

10. A gas generator in accordance with claim 1, characterized in that the filter unit surrounds the generator stages at least regionally.

11. A gas generator in accordance with claim 1, characterized in that the filter unit is arranged above the generator stages.

12. A gas generator in accordance with claim 1, characterized in that the filter unit is ring-shaped.

13. A gas generator in accordance with claim 1, characterized in that outflow openings are formed in a lower region of the pressure housings.

14. A gas generator in accordance with claim 1, characterized in that at least one deflection position is provided in the outflow passage system and forces a change of direction, in particular by approximately 90°

, on the gas flowing to the filter unit.

15. A gas generator in accordance with claim 14, characterized in that at least one impact surface extending approximately perpendicular to the flow direction of the gas to be redirected is provided at the deflection position.

16. A gas generator in accordance with claim 1, characterized in that a central outflow passage extends substantially over the total axial length of the filter housing and is surrounded by a filter unit in the region of the upper end wall of the filter housing.

17. A gas generator in accordance with claim 1, characterized in that the outflow openings open into an outflow passage surrounding the generator stages.

18. A gas generator in accordance with claim 1, characterized in that the filter housing is made as an outer housing of a generator.

19. A gas generator in accordance with claim 1, characterized in that the filter housing has a securing flange for the attachment to the airbag module.

20. A gas generator in accordance with claim 1, characterized in that the filter housing surrounds the generator stages in the manner of a clamp.

21. A gas generator in accordance with claim 1, characterized in that the filter housing is secured to the pressure housings of the generator stages by a reshaping operation, in particular by a rolled joint or by a beaded joint.

22. A gas generator in accordance with claim 1, characterized in that outflow openings of the filter housing are provided at the level of the filter unit.

23. A gas generator in accordance with claim 1, characterized in that the filter housing is in particular made in a dilatable manner to assist a pressure buffer function by the gas pressure which can be generated by means of the generator stages.

24. A gas generator in accordance with claim 1, characterized in that the pressure housings of the generator stages are each welded to a base plate, in particular using a laser welding process or a capacitor discharge welding process.

25. A gas generator in accordance with claim 1, characterized in that base plates or a common base plate of the pressure housings or generator stages form a rim projecting in the radial direction.