Gas generator

• US 20090039628A1
• Filed: 08/07/2008
• Published: 02/12/2009
• Est. Priority Date: 08/08/2007
• Status: Active Grant

• Current Assignee: TRW Airbag Systems GmbH (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Airbag Systems GmbH (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Schreiber, Simon, Zengerle, Werner, Schwuchow, Karsten, Leitl, Josef, Klimas, Juergen
• Granted Patent: US 8,047,567 B2
• Time in Patent Office: Days
• US Class Current: 280/736
• CPC Class Codes: B60R 21/2646 the reacting substances being supported by the inflatable member walls, or by a flexible support within it
• CPC Class Codes: F42B 3/04 for producing gas under pressure generators of inflation fluid especially adapted for vehicle air bags B60R21/26

Abstract

A gas generator, particularly for a vehicle occupant restraint system, has at least one igniter (12), a pyrotechnic solid propellant bed (22), a combustion chamber (20) containing the propellant bed (22) and at least one wall part (24), the wall part (24) being arranged in the combustion chamber (20), which is moved by a gas stream generated on activation of the gas generator into the region of the propellant bed (22) which is not yet ignited, and in its interior (25) defines a gas-directing channel reaching into the propellant bed (22).

Claims

1. A gas generator, particularly for a vehicle occupant restraint system, with at least one igniter (12),

a pyrotechnic solid propellant bed (22),

a combustion chamber (20) containing said propellant bed (22) and

at least one wall part (24),

said wall part (24) being arranged in said combustion chamber (20), which is moved by a gas stream generated on activation of said gas generator into a region of said propellant bed (22) which is not yet ignited, and which defines a gas-directing channel in its interior (25), said channel reaching into said propellant bed (22).

2. The gas generator according to claim 1 wherein said wall part (24) is hollow, has an interior (25) and an exterior (27) and is at least partially open radially during a movement, in order to allow hot gas to flow between the interior (25) of the wall part (24) and the exterior (27) of the wall part (24).

3. The gas generator according to claim 1 wherein said wall part (24) is constructed so that it moves as a whole in said combustion chamber (20).

4. The gas generator according to claim 1 wherein said wall part (24) is constructed so as to be elastic and extends into said propellant bed (22) on activation of said gas generator.

5. The gas generator according to claim 4 wherein said wall part (24) is a spring, particularly a helical spring.

6. The gas generator according to claim 1 wherein said wall part (24) has an open inflow end (31).

7. The gas generator according to claim 6 wherein said wall part (24) has an open or closed outflow end (33) opposed to said inflow end (31), by which said wall part (24) is moved ahead further into said solid propellant bed (22).

8. The gas generator according to claim 1 wherein said wall part (24) divides the combustion chamber (20) on movement into a radially inner and a radially outer section.

9. The gas generator according to claim 1 wherein said wall part (24), on activation of said gas generator, is moved from a position closer to said igniter (12) into a position further away from said igniter (12).

10. The gas generator according to claim 1 wherein a main direction of flow is given in said combustion chamber (20) and said wall part (24) is moved in this direction.

11. The gas generator according to claim 1 wherein a mounting is provided for said wall part (24).

12. The gas generator according to claim 11 wherein said mounting is a guide, particularly a linear guide.

13. The gas generator according to claim 11 wherein said mounting is a fastening of said wall part (24) on one side.

14. The gas generator according to claims 1 wherein said wall part (24) is a cylindrical hollow body, with generated gas flowing into said inflow end (31).

15. The gas generator according to claim 1 wherein a mounting is provided and said wall part (24) lies with a portion of its outer side against said outer housing (10) and thereby said mounting is formed for said wall part (24).

16. The gas generator according to claim 1 wherein in the non-activated state of said gas generator, propellant of said propellant bed (22) is situated inside said wall part (24).

17. The gas generator according to claim 1 wherein a dividing wall (18) is provided and, in the non-activated state of said gas generator, said wall part (24) being adjacent to said dividing wall (18) to said igniter (12).

18. The gas generator according to claim 17 wherein said dividing wall (18) has at least one through-flow opening (38) which opens into said interior (25) of said wall part (24).

19. The gas generator according to claim 1 wherein said igniter (12) is immediately adjacent to said hollow interior (25) of said wall part (24).