Dual flow inflator for a vehicular airbag system

• US 6,746,046 B2
• Filed: 03/19/2002
• Issued: 06/08/2004
• Est. Priority Date: 03/19/2002
• Status: Expired due to Fees

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Inventors: Young, Anthony M., Green, David J., Dinsdale, C. Paul, Rink, Karl K.
• Primary Examiner(s): English, Peter C.
• Application Number:
  US10/100,820
• Publication Number:
  US 20030178828A1
• Time in Patent Office: 812 Days
• Field of Search: 280/737, 280/736, 280/741, 280/742, 280/728.2, 280/730.2, 280/729, 102/530, 102/531, 137/68.13
• US Class Current: 280/737
• CPC Class Codes: B60R 2021/23107 the bag being integrated in a multi-bag system
• CPC Class Codes: B60R 2021/23386 External tether means
• CPC Class Codes: B60R 2021/2612 Gas guiding means, e.g. ducts
• CPC Class Codes: B60R 2021/2633 with a plurality of inflation levels
• CPC Class Codes: B60R 2021/2685 comprising a plurality of pressure chambers
• CPC Class Codes: B60R 21/232 Curtain-type airbags deploying mainly in a vertical direction from their top edge
• CPC Class Codes: B60R 21/26 characterised by the inflation fluid source or means to control inflation fluid flow arrangement or mounting thereof to the vehicle B60R21/20; blasting cartridges for producing gas under pressure in general F42B3/04; initiators or igniters therefor F42B3/10
• CPC Class Codes: B60R 21/264 using instantaneous generation of gas, e.g. pyrotechnic B60R21/268 takes precedence
• CPC Class Codes: B60R 21/272 with means for increasing the pressure of the gas just before or during liberation, e.g. hybrid inflators
• CPC Class Codes: Y10T 137/1647 Explosive actuation

Abstract

A dual flow inflator for airbags is disclosed, together with related manufacturing, installation, and deployment methods. The inflator may have a gas chamber with a first end with a first exit orifice and a second end with a second exit orifice. The exit orifices may be directed into inlet ports of an inflatable curtain so that inflation gases exit the inflator through the exit orifices and enter directly into the inflatable curtain. The exit orifices may provide axial gas flows in opposite directions so that each gas flow neutralizes the thrust of the other. The exit orifices may comprise frangible structures such as burst discs, scored surfaces, and compression closures. If desired, pistons may be utilized to ensure that the exit orifices are completely and simultaneously opened. Furthermore, the gas chamber may comprise a variety of configurations, including a unitary, one-piece structure, a multi-part structure with vessels attached to a tubular or spherical bulkhead, or a generally spherical shape.

Claims

1. An inflator for a vehicular airbag system, the inflator comprising:

a gas chamber having a longitudinal axis, the gas chamber comprising a first exit orifice oriented to provide a first gas flow out of the gas chamber, substantially parallel to the longitudinal axis, and a second exit orifice oriented to provide a second gas flow out of the gas chamber in a direction substantially opposite the first gas flow, the first and second exit orifices each having an open configuration and a sealed configuration; and

an initiator oriented nonparallel to the longitudinal axis and disposed in communication with the gas chamber to induce the first gas flow through the first exit orifice and the second gas flow through the second exit orifice.

2. The inflator of claim 1, wherein the first and second exit orifices are sized to eject the first and second gas flows substantially equally such that substantially no thrust is exerted on the inflator along the longitudinal axis.

3. The inflator of claim 1, wherein the first and second exit orifices are sized differently such that the first and second gas flows contain different amounts of gas.

4. The inflator of claim 1, wherein each of the first and second exit orifices comprises a frangible structure selected from the group consisting of burst discs, scored surfaces, and compression closures.

5. The inflator of claim 4, wherein the frangible structures are burst discs, the inflator further comprising a burst disc retention member disposed outside each of the burst discs to prevent ejection of the burst discs from the first and second exit orifices.

6. The inflator of claim 5, wherein the burst discs are shaped to uncover the first and second exit orifices in response to a pressure shock induced by activation of the initiator.

7. The inflator of claim 1, wherein the gas chamber comprises a substantially tubular shape, wherein the first and second exit orifices are disposed at opposite ends along the longitudinal axis of the substantially tubular shape.

8. The inflator of claim 1, further comprising:

a first piston disposed generally between the initiator and the first exit orifice, the first piston moving toward the first exit orifice in response to a pressure increase initiated by the initiator to move the first exit orifice to the open configuration; and

a second piston disposed generally between the initiator and the second exit orifice, the second piston moving toward the second exit orifice in response to a pressure increase initiated by the initiator to move the second exit orifice to the open configuration.

9. The inflator of claim 8, further comprising:

a first puncture member disposed between the first piston and the first exit orifice such that the first piston actuates the first puncture member to impact the first exit orifice upon activation of the initiator; and

a second puncture member disposed between the second piston and the second exit orifice such that the second piston actuates the second puncture member to impact the second exit orifice upon activation of the initiator.

10. The inflator of claim 1, further comprising a booster material positioned proximate the initiator to expedite the first and second gas flows.

11. The inflator of claim 1, further comprising a gas-producing material that substantially provides the first and second gas flows through operation of the initiator, independent of any additional initiator.

12. The inflator of claim 11, wherein the gas-producing material is selected to be insertable into the chamber as a cryogenic solid.

13. The inflator of claim 11, wherein the gas-producing material comprises compressed gas.

14. The inflator of claim 13, wherein the gas-producing material further comprises a liquid that vaporizes in response to decreasing pressure within the gas chamber to supplement the first and second gas flows.

15. The inflator of claim 13, wherein the gas-producing material further comprises a pyrotechnic gas generant that combusts to supplement the first and second gas flows.

16. The inflator of claim 11, wherein the gas producing material comprises a dissociating gas.

17. The inflator of claim 11, wherein the gas-producing material comprises a pyrotechnic gas generant that combusts to provide the first and second gas flows, wherein the pyrotechnic gas generant is selected from the group consisting of gaseous generants, liquid generants, solid generants, and combinations of two or more solid, liquid, or gaseous generants.

18. The inflator of claim 1, wherein the gas chamber is an integrally formed, unitary body.

19. The inflator of claim 1, wherein the gas chamber comprises:

a first vessel having an interior end with a first interior opening and an exterior end on which the first exit orifice is disposed;

a second vessel having an interior end with a second interior opening and an exterior on which the second exit orifice is disposed; and

a bulkhead with a first aperture shaped to communicate with the interior end of the first vessel and a second aperture sized to communicate with the interior end of the second vessel, the second aperture positioned opposite the first aperture.

20. The inflator of claim 1, wherein the gas chamber comprises a first end on which the first outlet orifice is disposed and a second end on which the second outlet orifice is disposed, wherein the first end is shaped to be inserted into a first inlet port of an inflatable curtain of the vehicular airbag system, and wherein the second end is shaped to be inserted into a second inlet port of the inflatable curtain.

21. The inflator of claim 1, wherein the first and second exit orifices are positioned to direct the first and second gas flows into an inflatable cushion of a type selected from the group consisting of a driver'"'"'s side airbag, a passenger'"'"'s side airbag, an overhead airbag, and a knee bolster.

22. The inflator of claim 1, wherein the gas chamber comprises an elongated shape with a substantially circular cross section.

23. The inflator of claim 1, wherein the gas chamber comprises a substantially spherical shape.

24. An inflator for a vehicular airbag system, the inflator comprising:

a gas chamber having a longitudinal axis, the gas chamber comprising a first end with a first exit orifice and a second end with a second exit orifice displaced from the first orifice along the longitudinal axis, the first and second exit orifices each having an open configuration and a sealed configuration;

an initiator receptacle formed separately from and attached to the gas chamber; and

an initiator seated in the initiator receptacle, displaced from the longitudinal axis, to produce heat between the first and second ends to induce a first gas flow through the first exit orifice and a second gas flow through the second exit orifice.

25. The inflator of claim 24, wherein each of the first and second exit orifices comprises a frangible structure selected from the group consisting of burst discs, scored surfaces, and compression closures.

26. The inflator of claim 24, wherein the first exit orifice is oriented to inject the first gas flow substantially parallel to the longitudinal axis, and wherein the second exit orifice is oriented to inject the second gas flow in a direction substantially opposite the first gas flow.

27. An inflator for a vehicular airbag system, the inflator comprising:

a first vessel having an interior end with a first interior opening and an exterior end with a first exit orifice that opens in response to activation of the inflator to permit pressurized gas to escape from the first vessel;

a second vessel having an interior end with a second interior opening and an exterior end with a second exit orifice that opens in response to activation of the inflator to permit pressurized gas to escape from the second vessel;

a bulkhead with a first aperture shaped to communicate with the interior end of the first vessel and a second aperture sized to communicate with the interior end of the second vessel, the second aperture positioned opposite the first aperture; and

an initiator oriented nonparallel to a longitudinal axis extending through the first and second orifices.

28. The inflator of claim 27, further comprising a gas-producing material of a type selected to be insertable into the first interior opening of the first vessel as a cryogenic solid, the gas-producing material producing gas in response to activation of the initiator.

29. The inflator of claim 27, wherein the bulkhead comprises a substantially tubular shape.

30. The inflator of claim 27, wherein the bulkhead comprises a substantially spherical shape.

31. The inflator of claim 27, wherein the initiator is in communication with the bulkhead and retained by an initiator aperture of the bulkhead.

32. The inflator of claim 27, wherein the first vessel is shaped to be inserted into a first inlet port of an inflatable curtain of the vehicular airbag system, and wherein the second vessel is shaped to be inserted into a second inlet port of the inflatable curtain.

33. An inflator for a vehicular airbag system, the inflator comprising:

a first hemispherical portion with a first exit orifice having an open configuration and a sealed configuration;

a second hemispherical portion with a second exit orifice positioned opposite the first exit orifice, the second exit orifice having an open configuration and a sealed configuration; and

an initiator oriented nonparallel to a longitudinal axis extending through the first and second orifices and disposed in communication with a cavity formed by the first and second hemispherical portions to induce a first gas flow through the first exit orifice and a second gas flow through the second exit orifice.

34. The inflator of claim 33, wherein the first and second hemispherical portions are integrally formed with each other.

35. The inflator of claim 33, wherein the first and second hemispherical portions are separately formed and affixed together.

36. The inflator of claim 33, further comprising a mounting flange extending outward from an equatorial region between the first and second hemispherical portions.

37. The inflator of claim 33, wherein the first hemispherical portion is shaped to be inserted into a first inlet port of an inflatable curtain of the vehicular airbag system, and wherein the second hemispherical portion is shaped to be inserted into a second inlet port of the inflatable curtain.

38. The inflator of claim 33, wherein the first and second exit orifices are positioned to inflate a driver'"'"'s side airbag.

39. The inflator of claim 33, wherein the first and second exit orifices are positioned to inflate a passenger'"'"'s side airbag.

40. The inflator of claim 33, wherein the first and second exit orifices are positioned to inflate an overhead airbag.

41. The inflator of claim 33, wherein the first and second exit orifices are positioned to inflate a knee bolster.

42. A method for manufacturing an inflator for a vehicular airbag system, the method comprising:

providing a gas chamber having a first end and a second end opposite the first end;

providing an initiator receptacle;

forming a first exit orifice in the first end, the first exit orifice having a sealed configuration and an open configuration;

forming a second exit orifice in the second end, the second exit orifice having a sealed configuration and an open configuration;

providing an initiator;

attaching the initiator receptacle to the gas chamber;

installing the initiator in the initiator receptacle such that the initiator is displaced from a longitudinal axis extending through the first and second orifices to position the initiator in communication with a portion of the gas chamber between the first and second ends;

inserting gas-producing material into the gas chamber; and

sealing the chamber with the first and second exit orifices in the sealed configuration to prevent escape of the gas-producing material until the initiator has been activated.

43. The method of claim 42, wherein providing a gas chamber comprises providing an integrally-formed, unitary body.

44. The method of claim 42, wherein providing a gas chamber comprises providing:

a first vessel having an interior end with a first interior opening and an exterior end on which the first exit orifice is disposed;

a second vessel having an interior end with a second interior opening and an exterior on which the second exit orifice is disposed; and

a bulkhead with a first aperture shaped to communicate with the interior end of the first vessel and a second aperture sized to communicate with the interior end of the second vessel, the second aperture positioned opposite the first aperture.

45. The method of claim 42, wherein forming the first and second exit orifices comprises forming frangible structures selected from the group consisting of burst discs, scored surfaces, and compression closures.

46. The method of claim 45, wherein the frangible structures are burst discs, the method further comprising:

providing two burst disc retention members; and

disposing a burst disc retention member outside each of the burst discs to prevent ejection of the burst discs from the first and second exit orifices.

47. The method of claim 45, wherein forming frangible structures comprises providing burst discs configured to unblock the first and second exit orifices in response to pressure shock.

48. The method of claim 42, wherein inserting the gas-producing material into the gas chamber comprises disposing the gas-producing material to substantially provide first and second gas flows through the first and second exit orifices through operation of the initiator, independent of any additional initiator.

49. The inflator of claim 48, wherein the gas-producing material is selected to be insertable into the chamber as a cryogenic solid.

50. A method for inflating an inflatable curtain of a vehicular airbag system, the vehicular airbag system comprising an inflator having an initiator, a first end with a first exit orifice disposed proximate a first inlet port of the inflatable curtain, and a second end with a second exit orifice disposed proximate a second inlet port of the inflatable curtain, wherein each of the first and second exit orifices have an open configuration and a sealed configuration, the method comprising:

activating the initiator, wherein the initiator is oriented nonparallel to a longitudinal axis extending through the first and second exit orifices;

moving the first exit orifice from the sealed configuration to the open configuration to permit a first gas flow to flow into the inflatable curtain from the inflator through the first exit orifice; and

moving the second exit orifice from the sealed configuration to the open configuration to permit a second gas flow to flow into the inflatable curtain from the inflator through the second exit orifice.

51. The method of claim 50, wherein moving the first and second orifices from the sealed configuration to the open configuration comprises activating a single initiator of the inflator to induce the first and second gas flows.

52. The method of claim 50, wherein the first gas flow is injected from the inflator substantially parallel to a longitudinal axis of the inflator, and wherein the second gas flow is injected from the inflator in a direction substantially opposite the first gas flow.

53. The method of claim 50, wherein moving the first and second exit orifices from the sealed configuration to the open configuration comprises removing a burst disc from each of the first and second exit orifices.

54. The method of claim 53, wherein removing a burst disc from each of the first and second exit orifices comprises receiving a pressure shock in each burst disc and deflecting each burst disc in response to the pressure shock to enable passage of each burst disc through the corresponding exit orifice.

55. The method of claim 50, wherein moving the first and second exit orifices from the sealed configuration to the open configuration comprises splitting scores extending along the first end and the second end.

56. The method of claim 50, wherein moving the first and second orifices from the sealed configuration to the open configuration comprises splitting welds extending along the first end and the second end.

57. A method for manufacturing an inflator for a vehicular airbag system, the method comprising:

providing a gas chamber having a first hemispherical portion and a second hemispherical portion;

forming a first exit orifice in the first hemispherical portion, the first exit orifice having a sealed configuration and an open configuration;

forming a second exit orifice in the second hemispherical portion, the second exit orifice positioned opposite the first exit orifice and having a sealed configuration and an open configuration; and

attaching an initiator to one of the hemispherical portions such that the initiator is oriented nonparallel to a longitudinal axis extending through the first and second orifices.

58. The method of claim 57, wherein providing the gas chamber comprises:

attaching the first and second hemispherical portions together to provide a substantially spherical shape.

59. The method of claim 57, further comprising forming a mounting flange that extends outward from an equatorial region between the first and second hemispherical portions.