Gas generator

• US 7,350,810 B2
• Filed: 11/29/2005
• Issued: 04/01/2008
• 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): Ilan; Ruth
• Assistant Examiner(s): ROCCA, JOSEPH M
• Application Number:
  US11/288,963
• Publication Number:
  US 20060119086A1
• Time in Patent Office: 854 Days
• Field of Search: 280/736, 280/737, 280/741
• 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 for an airbag module, comprising:

a filter housing having a first peripheral configuration;

a first generator stage disposed within the filter housing, the first generator stage having a first pressure housing and an igniter disposed therein, the first pressure housing having a peripheral wall and a top portion connecting the peripheral wall, the peripheral wall having an outer wall portion and an inner wall portion;

a second generator stage disposed within the filter housing, the second generator stage having a second pressure housing and an igniter disposed therein, the second pressure housing having a peripheral wall and a top portion connecting the peripheral wall, the peripheral wall having an outer wall portion and an inner wall portion, the first pressure housing and the second pressure housing being arranged within the filter housing such that the inner wall portion of the first pressure housing and the inner wall portion of the second pressure housing define a central outflow passage while the outer wall portion of the first pressure housing and outer wall portion of the second pressure housing define an outer periphery that contacts an inner surface of a wall of the filter housing defining the first peripheral configuration;

a plurality of openings disposed in the wall of the filter housing defining the first peripheral configuration;

a flow path provided between the plurality of openings and the central outflow passage; and

a filter disposed in the filter housing such that gas flow from the central outflow passage passes through the filter prior to exiting the gas generator via the plurality of openings disposed in the wall of the filter housing.

2. A gas generator in accordance with claim 1, wherein the first generator stage and the first pressure housing is larger than the second generator stage and second pressure housing.

3. A gas generator in accordance with claim 1, wherein the filter is arranged above the plurality of openings.

4. A gas generator in accordance with claim 1, wherein the filter is arranged at least substantially between the first pressure housing and the second pressure housing.

5. A gas generator in accordance with claim 1, wherein the filter is located above the top wall portion of the first generator stage and the top wall portion of the second generator stage.

6. A gas generator in accordance with claim 1, wherein the inner wall portion of the first pressure housing and the inner wall portion of the second pressure housing each have a plurality of openings in fluid communication with the central outflow passage when the gas generator is ignited.

7. A gas generator in accordance with claim 1, wherein the plurality of openings are located above the top portion of the first pressure housing and the top portion of the second pressure housing and gas flow from the central outflow passage impacts an impact surface of the filter housing.

8. A gas generator in accordance with claim 7, wherein the impact surface is positioned perpendicular to gas flow from the central outflow passage.

9. The gas generator as in claim 1, wherein contact between the outer periphery defined by the outer wall portion of the first pressure housing and the outer wall portion of the second pressure housing and the inner surface of the wall of the filter housing is facilitated by a plurality of fixing impressions formed in the wall of the filter housing.

10. The gas generator as in claim 9, wherein the plurality of fixing impressions are alternately arranged with the plurality of openings in the wall of the filter housing.

11. The gas generator as in claim 1, wherein the inner wall portion of the first pressure housing and the inner wall portion of the second pressure housing each comprise a curved portion bounded by a pair of planar surfaces and the curved portion of the inner wall portion of the first pressure housing and the inner wall portion of the second pressure housing define the central outflow passage while the pair of planar surfaces of the inner wall portion of the first pressure housing and the iner wall portion of the second pressure housing contact each other.

12. A gas generator as in claim 11, wherein the curved portion of the inner wall portion of the first pressure housing and the inner wall portion of the second pressure housing each have a plurality of openings in fluid communication with the central outflow passage when the gas generator is ignited.

13. A gas generator as in claim 12, wherein the igniter of the first generator stage and the second generator stage are capable of being independently actuated.

14. A gas generator as in claim 1, wherein the peripheral wall of the first pressure housing is welded to a first base plate and the peripheral wall of the second pressure housing is weld to a second base plate, the first base plate and the second base plate each being configured to contact each other proximate to the central outflow passage and the filter housing secures the first base plate and the second base to each other.

15. A gas generator as in claim 8, wherein the filter housing is secured to the first generator stage and the second generator stage by a reshaping operation comprising a rolled joint or a beaded joint.

16. A gas generator as in claim 1, wherein the filter housing is secured to the first generator stage and the second generator stage by a welding process.

17. A gas generator as in claim 1, wherein the filter housing further comprises a peripheral mounting flange and the plurality of openings in the wall of the filter housing are proximate to a point of contact between the inner surface of the wall of the filter housing and the outer periphery defined by the outer wall portion of the first pressure housing and the second pressure housing.

18. The gas generator as in claim 1, wherein the peripheral wall of the first pressure housing is secured to a first base plate and the peripheral wall of the second pressure housing is secured to a second base plate, the first base plate and the second base plate each having a configuration such that when assembled together the first base plate and the second base plate define a periphery substantially similar to the first peripheral configuration of the filter housing such that the filter housing can be secured to the first base plate and the second base plate to secure the first pressure housing and the second pressure housing within the filter housing.

19. A gas generator as in claim 1, wherein the outer periphery defined by the outer wall portion of the first pressure housing and the outer wall portion of the second pressure housing is substantially the same configuration as the first peripheral configuration.

20. A gas generator as in claim 1, wherein the outer periphery defined by the outer wall portion of the first pressure housing and the outer wall portion of the second pressure housing is circular and the first peripheral configuration is circular.

21. A gas generator for an airbag module, comprising:

a filter housing having a first peripheral configuration;

a first generator stage disposed within the filter housing, the first generator stage having a first pressure housing and an igniter disposed therein, the first pressure housing having a peripheral wall and a top portion connecting the peripheral wall, the peripheral wall having an outer wall portion and an inner wall portion;

a second generator stage disposed within the filter housing, the second generator stage having a second pressure housing and an igniter disposed therein, the second pressure housing having a peripheral wall and a top portion connecting the peripheral wall, the peripheral wall having an outer wall portion and an inner wall portion, the first pressure housing and the second pressure housing being arranged within the filter housing such that the inner wall portion of the first pressure housing and the inner wall portion of the second pressure housing define a central outflow passage while the outer wall portion of the first pressure housing and outer wall portion of the second pressure housing define an outer periphery that is substantially similar to the first peripheral configuration defined by the wall of the filter housing and the outer periphery defined by the outer wall portion of the first pressure housing and the outer wall portion of the second pressure housing is in a facing spaced relationship with an inner surface of the wall of the filter housing;

a plurality of openings disposed in the wall of the filter housing defining the first peripheral configuration;

a flow path provided between the plurality of openings and the central outflow passage; and

a filter disposed between the plurality of openings in the wall of the filter housing and the outer periphery defined by the outer wall portion of the first pressure housing and the outer wall portion of the second pressure housing such that gas flow from the central outflow passage passes through the filter prior to exiting the gas generator via the plurality of openings disposed in the wall of the filter housing.

22. A gas generator as in claim 21, wherein the filter is ring shaped.

23. A gas generator as in claim 21, wherein the peripheral wall of the first pressure housing is welded to a first base plate and the peripheral wall of the second pressure housing is weld to a second base plate, the first base plate and the second base plate each being configured to contact each other proximate to the central outflow passage and the filter housing secures the first base plate and the second base to each other.

24. A gas generator as in claim 21, wherein the inner wall portion of the first pressure housing and the inner wall portion of the second pressure housing each have a plurality of openings in fluid communication with the central outflow passage when the gas generator is ignited.

25. A gas generator as in claim 21, wherein the igniter of the first generator stage and the second generator stage are capable of being independently actuated and the first generator stage is larger than the second generator stage.