Gas generator

• US 20060117982A1
• 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: Autoliv AB (Autoliv Incorporated)
• Inventors: Winterhalder, Marc Alexander, Lehniger, Peter, Gaertner, Jochem, Blessing, Uwe
• Granted Patent: US 7,883,111 B2
• Time in Patent Office: Days
• US Class Current: 102/530
• 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, in particular for airbag modules in motor vehicles, comprising two generator stages each of which includes in its own pressure housing at least one igniter, at least one propellant charge and at least one combustion chamber, with an inner generator stage being arranged at least substantially inside an outer generator stage and both generator stages at least partly being arranged in a common filter housing together with a common filter unit arranged outside a pressure housing of the outer generator stage.

2. A gas generator in accordance with claim 1, characterized in that the pressure housing of the outer generator stage is cylindrical and the igniters of the two generator stages are arranged at least approximately symmetrical with respect to a central axis of the pressure housing.

3. A gas generator in accordance with claim 1, characterized in that both generator stages are cylindrical.

4. A gas generator in accordance with claim 1, characterized in that central axes of all igniters and housings and of the filter unit are disposed in a common plane.

5. A gas generator in accordance with claim 1, characterized in that the inner generator stage almost completely fills the outer generator stage in height.

6. A gas generator in accordance with claim 1, characterized in that the filter unit and the two generator stages at least substantially completely fill the filter housing.

7. A gas generator in accordance with claim 1, characterized in that the filter unit is made in ring shape and surrounds the outer generator stage.

8. A gas generator in accordance with claim 7, characterized in that the outer generator stage has a larger axial length than the filter ring.

9. A gas generator in accordance with claim 1, characterized in that the pressure housing of the outer generator stage has outflow openings which are arranged at the level of the lower end of the filter unit and open into a space receiving the filter unit.

10. A gas generator in accordance with claim 9, characterized in that the outflow openings of the pressure housing of the outer generator stage lie lower than outflow openings of the filter housing which are preferably disposed approximately at the same level as outflow openings of the pressure housing of the inner generator stage.

11. A gas generator in accordance with claim 1, characterized in that the pressure housing of the inner generator stage has outflow openings which open radially into the outer generator stage.

12. A gas generator in accordance with claim 1, characterized in that outflow openings of the pressure housing of the inner generator stage are arranged in the upper region of the inner generator stage.

13. A gas generator in accordance with claim 1, characterized in that the pressure housing of the outer generator stage has radial outflow openings in a lower region.

14. A gas generator in accordance with claim 1, characterized in that the filter housing has a radially widened portion at the level of the filter unit.

15. A gas generator in accordance with claim 1, characterized in that the igniters of the generator stages are secured to a common base plate.

16. A gas generator in accordance with claim 1, characterized in that all weld connections between components forming the pressure housings are made by the same welding process, in particular by capacitor discharge welding, by laser welding or by friction welding.

17. A gas generator in accordance with claim 1, characterized in that the filter housing is secured by a reshaping operation, in particular by a rolled joint or by a beaded joint, to the two 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 an airbag module.

20. A gas generator in accordance with claim 1, characterized in that outflow openings of the filter housing are provided in an upper region of the filter unit.

21. 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.

22. A gas generator in accordance with claim 1, characterized in that the filter housing surrounds the generator stages, the filter unit and a base plate common to the generator stages in the manner of a clamp.