Assembly comprising a diffuser and a gas generator, airbag module and method for installing an assembly

Patent metadata

Field	Value
Publication number	US-11548466-B2
Application number	US-201917281282-A
Country	US
Kind code	B2
Filing date	Sep 10, 2019
Priority date	Oct 2, 2018
Publication date	Jan 10, 2023
Grant date	Jan 10, 2023

Abstract

In an assembly (20) of an elongate inflator (10) which has an outer housing (14) with outflow openings (18) spread along the circumference (U) and defining an outflow area (16) and an outflow direction, and of a clamp-type diffusor (22) enclosing the outflow area (16), the diffusor (22) includes a central receiving opening (24) into which the outer housing (14) protrudes so that the diffusor (22) circumferentially encloses an axial portion of the outer housing (14) which comprises the outflow area (16). At the inner side of the diffusor (22) delimiting the receiving opening (24) at least one bearing surface (34) and at least one gas guiding surface (30) are provided, wherein the bearing surface (34) bears directly against the outer housing (14) of the inflator (10) and the gas guiding surface (30) is radially spaced apart from the outer housing (14) while forming at least one collecting chamber (30) into which gas flowing out of the outflow area (16) is flowing. The collecting chamber (32) opens into at least one outlet opening (36) through which gas exits the diffusor (22) in an outlet direction (RD) transversely to the outflow direction out of the inflator (10).

First claim

The invention claimed is:

1. An assembly comprising:
an elongate inflator having an outer housing extending axially in a forward and rearward direction, the inflator comprising an outflow area including a plurality of outflow openings distributed about a circumference of the outer housing, the outflow openings being arranged in first and second outflow zones spaced axially along the length of the outflow area and separated by a separation area of the outflow area that is free from outflow openings;
a diffusor comprising a sheet of material that extends around the outer housing so as to cover the outflow area, the diffuser comprising a central bearing surface that engages the outer housing along the separation area to help connect the diffusor to the outer housing, the diffusor comprising a first collection chamber that extends axially rearward from the central bearing surface and covers the outflow openings of the first outflow zone, and a second collection chamber that extends axially forward from the central bearing surface and covers the outflow openings of the second outflow zone;
wherein the first collection chamber comprises a detent element that extends circumferentially around the outer housing and is received in a circumferential bead of the outer inflator housing to help connect the diffuser to the inflator, the first collection chamber further comprising a rear outlet opening that extends through the sheet of material;
wherein the second collection chamber is configured to converge radially upon the outflow area of the inflator and define a forward bearing surface, wherein the forward bearing surface engages the outer housing along a radially extending portion of the outer housing, and wherein the second collection chamber forms a forward outlet opening in the form of a radial gap where the forward bearing surface is spaced from the outer housing.

2. The assembly according to claim 1 , wherein the outlet direction extends axially relating to a longitudinal axis of the inflator.

3. The assembly according to claim 1 , wherein the at least one outlet opening comprises at least two outlet openings that are oppositely directed.

4. The assembly according to claim 1 , wherein the at least one outlet opening comprises two or more oppositely directed outlet openings which are spaced apart from each other in a circumferential direction.

5. The assembly according to claim 1 , wherein, adjacent to the at least one outlet opening, the gas guiding surface is located radially further outside than the at least one associated collecting chamber remote from the at least one outlet opening.

6. The assembly according to claim 1 , wherein the at least one bearing surface delimits the at least one collecting chamber in at least one of the axial direction and the circumferential direction.

7. The assembly according to claim 1 , wherein the at least one collecting chamber comprises one or more collecting chambers that do not continuously extend in the circumferential direction and which, at its two circumferential ends, opens into the at least one outlet opening.

8. The assembly according to claim 1 , wherein two collecting chambers are provided each of which extends along the circumferential direction and each of which opens, at one circumferential end, into the at least one outlet opening.

9. The assembly according to claim 1 , wherein the at least one bearing surface divides the gas flow exiting the inflator into at least two partial flows, wherein the bearing surface extends helically around the outer housing or only in the circumferential direction around the outer housing.

10. The assembly according to claim 1 , wherein a bearing surface peripheral around the entire circumference of the inflator is provided which includes two first portions extending only along the circumferential direction and two second portions extending inclined to the circumferential direction and to the axial direction, the second portions connecting the first portions.

11. The assembly according to claim 1 , wherein the outflow area is provided at a longitudinal end of the inflator.

12. The assembly according to claim 1 , wherein the outflow area of the inflator is divided into at least two zones that are separated from each other by a separation area of the outer housing without outflow openings, wherein a bearing surface of the diffusor is positioned in the separation area between the zones.

13. The assembly according to claim 1 , wherein the outlet openings are spread over the circumference and are separated by separation webs, wherein the separation webs at least partially form the at least one bearing surface which delimit the collecting chamber in the axial direction toward a longitudinal end of the inflator.

14. An airbag module comprising an airbag and an assembly according to claim 1 , wherein the diffusor is arranged completely in an inflatable inner volume of the airbag.

15. A method for mounting an assembly according to claim 1 , comprising the following steps:
a one-piece diffusor blank is fabricated of a sheet metal, wherein all bearing surfaces and all gas guiding surfaces are preformed,
the diffusor blank is bent around the outflow area of the inflator, wherein it adopts the final shape of the diffusor, and
portions of the diffusor blank are fixed to themselves so as to circumferentially close the diffusor blank.

16. A method for mounting an assembly according to claim 1 , comprising the following steps:
a one-piece diffusor is fabricated of a one-piece closed tube element or of a sheet metal, with all of the bearing surfaces and all of the gas guiding surfaces being preformed,
the diffusor is slipped onto the outflow area of the inflator, and a bearing surface of the diffusor is plastically deformed in the area of a bead of the inflator, so that at least portions of the bearing surface engage in the bead along the circumference and a positive locking is formed.

17. A method for mounting an assembly according to claim 1 , comprising the following steps:
a one-piece diffusor is fabricated of a closed tube element or of a sheet metal, wherein all of the bearing surfaces, all of the gas guiding surfaces and all of the detent elements are preformed,
the diffusor is slipped onto the outflow area of the inflator so that at least portions of the detent elements engage in the bead of the inflator along the circumference and a positive locking is formed.

18. The assembly according to claim 1 , wherein a collecting chamber opening into an outlet opening 36 b at an axial end is provided.

19. The assembly according to claim 18 , wherein the outlet opening is formed by a radial gap between the outer housing and the inner side of the diffusor.

20. The assembly according to claim 1 , wherein the diffusor comprises at least one detent element, wherein the detent element can engage in a bead for fastening and fixing the diffusor on the inflator.

21. The assembly according to claim 20 , wherein the diffusor is made from spring steel.

Assignees

• Zf Automotive Germany Gmbh

Inventors

• Disam Robert
• Fischer Anton

Classifications

• B60R21/2171 Primary

  specially adapted for elongated cylindrical or bottle-like inflators with a symmetry axis perpendicular to the main direction of bag deployment, e.g. extruded reaction canisters (B60R21/2176 takes precedence) · CPC title

• B60R2021/2612

  Gas guiding means, e.g. ducts · CPC title

• B60R21/262

  Elongated tubular diffusers, e.g. curtain-type · CPC title

• B60R21/217 Primary

  Inflation fluid source retainers, e.g. reaction canisters; Connection of bags, covers, diffusers or inflation fluid sources therewith or together · CPC title

• B60R21/261

  with means other than bag structure to diffuse or guide inflation fluid · CPC title