Gas generating system

• US 20060273564A1
• Filed: 06/01/2006
• Published: 12/07/2006
• Est. Priority Date: 06/02/2005
• Status: Active Grant

• Current Assignee: Joyson Safety Systems Acquisition, LLC
• Original Assignee: TK Holdings Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: McCormick, David M., Hardenburg, Robert M., Vergara, Bernardo V.
• Granted Patent: US 7,654,565 B2
• Time in Patent Office: Days
• US Class Current: 280/740
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder
• CPC Class Codes: C06D 5/06 by reaction of two or more solids
• 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 generating system for use in an inflatable vehicle occupant protection system is provided wherein an end closure is coupled to an outer housing at a first end, in a metal-to-metal seal. The gas generating system may also include a baffle system having a plurality of flow orifices defining a flow path for generated gases through an interior of the gas generating system, and a plurality of particulate aggregation surfaces positioned along the flow path of the gases for changing a flow direction of gases impinging on the aggregation surfaces. Each aggregation surface of the plurality of aggregation surfaces is oriented such that a difference between a flow direction of the gases prior to impinging on the aggregation surface and a flow direction of the gases after impinging on the aggregation surface is at least approximately 90°, wherein particulates in gases impinging on the aggregation surfaces aggregate on the surfaces.

Claims

1. A gas generating system comprising:

a baffle system including a plurality of flow orifices defining a flow path for generated gases through an interior of the gas generating system, and a plurality of particulate aggregation surfaces positioned along the flow path of the gases for changing a flow direction of gases impinging on the aggregation surfaces, each aggregation surface of the plurality of aggregation surfaces being oriented such that a difference between a flow direction of the gases prior to impinging on the aggregation surface and a flow direction of the gases after impinging on the aggregation surface is at least approximately 90°

, wherein particulates in gases impinging on the aggregation surfaces aggregate on the surfaces.

2. The gas generating system of claim 1 further comprising a smokeless gas generant composition positioned in the interior of the gas generating system.

3. The gas generating system of claim 2 wherein the gas generant composition comprises a mixture of a high-nitrogen nonazide fuel selected from the class consisting of 1-, 3-, and 5-substituted amine salts of triazoles, and, 1- and 5-substituted amine salts of tetrazoles, and dry-mixed with an oxidizer selected from the group consisting of phase stabilized ammonium nitrate.

4. The gas generating system of claim 2 wherein the gas generant composition comprises a mixture of:

a high-nitrogen fuel selected from the class consisting of 1-, 3-, and 5-substituted nonmetal salts of triazoles, and, 1- and 5-substituted nonmetal salts of tetrazoles;

a first oxidizer selected from the group consisting of phase stabilized ammonium nitrate;

a metallic second oxidizer; and

an inert component.

5. The gas generating system of claim 1 wherein each aggregation surface of the plurality of aggregation surfaces is substantially perpendicular to the flow direction of the gases impinging on the respective aggregation surface.

22. The gas generating system of claim 1 wherein the gas generating system is a filterless gas generating system.

6. A gas generating system comprising:

an outer housing including a combustion chamber, a first end, and a second end;

an end closure coupled to the housing at said first end in a metal-to-metal seal;

a high gas-yield, low solids-producing gas generant composition positioned in the combustion chamber; and

a baffle system including;

a plurality of flow orifices defining a flow path for gases generated by combustion of the gas generant composition, the flow path extending between the combustion chamber and an exterior of the gas generating system, and a plurality of particulate aggregation surfaces positioned along the flow path of the gases for changing a flow direction of gases impinging on the aggregation surfaces, wherein particulates in gases impinging on the aggregation surfaces aggregate on the surfaces.

7. The gas generating system of claim 6 wherein each aggregation surface of the plurality of aggregation surfaces is oriented such that a difference between a flow direction of the gases prior to impinging on the aggregation surface and a flow direction of the gases after impinging on the aggregation surface is at least approximately 90°

.

8. The gas generating system of claim 6 further comprising:

an inner housing defining the combustion chamber, the inner housing being positioned with the outer housing to define a gas flow passage extending between the inner housing and the outer housing, the inner housing including at least one first orifice formed therealong to enable fluid communication between the combustion chamber and the gas flow passage;

a baffle member defining a baffle member interior in fluid communication with the gas flow passage; and

a nozzle in fluid communication with the baffle member interior and coupled to the outer housing, the nozzle having at least one gas exit orifice to enable fluid communication between an interior of the outer housing and an exterior of the outer housing.

9. The gas generating system of claim 8 wherein an aggregation surface of the plurality of aggregation surfaces is located along an inner surface of the outer housing opposite the at least one orifice formed along the inner housing.

10. The gas generating system of claim 8 wherein an aggregation surface of the plurality of aggregation surfaces is located along an inner surface of the inner housing.

11. The gas generating system of claim 8 wherein the baffle member has an annular base portion and an annular sleeve extending from the base portion into the inner housing, the inner housing has at least one second orifice formed therealong opposite the annular sleeve to enable fluid communication between the gas flow passage and the baffle member interior, and wherein an aggregation surface of the plurality of aggregation surfaces is located along a surface of the annular sleeve extending opposite the at least one second orifice formed along the inner housing.

12. The gas generating system of claim 8 wherein an end portion of the inner housing abuts an end portion of the outer housing to for a gas-tight seal therebetween, and wherein an aggregation surface of the plurality of aggregation surfaces is located proximate the abutting inner and outer housing portions.

13. The gas generating system of claim 8 wherein the baffle member comprises a substantially circular base portion, a substantially cylindrical wall extending from the base portion and in fluid communication with the gas flow passage, the base portion and wall combining to define a baffle chamber in fluid communication with the nozzle, and at least one second orifice formed in the wall to enable fluid communication between the gas flow passage and the baffle chamber.

14. The gas generating system of claim 6 wherein the gas generant composition comprises a mixture of:

a high-nitrogen fuel selected from the class consisting of 1-, 3-, and 5-substituted nonmetal salts of triazoles, and, 1- and 5-substituted nonmetal salts of tetrazoles;

a first oxidizer selected from the group consisting of phase stabilized ammonium nitrate;

a metallic second oxidizer; and

an inert component.

15. The gas generating system of claim 6 wherein the outer housing has an outer diameter of approximately 20 mm diameter.

16. The gas generating system of claim 6 wherein the gas generant composition is a smokeless gas generant composition.

17. The gas generating system of claim 6 wherein the gas generant composition comprises a mixture of:

a high-nitrogen fuel selected from the class consisting of 1-, 3-, 5-substituted amine salts of triazoles and 1- and 5-substituted amine salts of tetrazoles, said fuel employed in a concentration of 13 to 38% by weight of the gas generant composition;

a first oxidizer consisting of phase stabilized ammonium nitrate, said first oxidizer employed in a concentration of 46 to 87% by weight of the gas generant composition;

a metallic second oxidizer employed in a concentration of 0.1 to 25% by weight of the gas generant composition; and

an inert component employed in a concentration of 0.1 to 8% by weight of the gas generant composition, wherein said fuel is selected from the group consisting of monoguanidinium salt of 5,5′

-Bi-1H-tetrazole, diguanidinium salt of 5,5′

-Bi-1H-tetrazole, monoaminoguanidinium salt of 5,5′

-Bi-1H-tetrazole, diaminoguanidinium salt of 5,5′

-Bi-1H-tetrazole monohydrazinium salt of 5,5′

-Bi-1H-tetrazole, dihydrazinium salt of 5,5′

-Bi-1H-tetrazole, monoammonium salt of 5,5′

-Bi-1H-tetrazole, diammonium salt of 5,5-Bi-1H-tetrazole, mono-3-amino-1,2,4-triazolium salt of 5,5′

-Bi-1H-tetrazole, di-3-amino-1,2,4-triazolium salt of 5,5′

-Bi-1H-tetrazole, diguanidinium salt of 5,5′

-Azobis-1H-tetrazole, and monoammonium salt of 5-Nitramino-1H-tetrazole.

18. The gas generating system of claim 6 wherein the gas generant composition comprises a mixture of a high-nitrogen nonazide fuel selected from the class consisting of 1-, 3-, and 5-substituted amine salts of triazoles, and, 1- and 5-substituted amine salts of tetrazoles;

and dry-mixed with an oxidizer selected from the group consisting of phase stabilized ammonium nitrate.

19. The gas generating system of claim 6 wherein the gas generant composition comprises a mixture of:

a high-nitrogen nonazide fuel selected from the class consisting of 1-, 3-, 5-substituted amine salts of triazoles and 1- and 5-substituted amine salts of tetrazoles, said fuel employed in a concentration of 15 to 65% by weight of the gas generant composition; and

an oxidizer consisting of phase stabilized ammonium nitrate, said oxidizer employed in a concentration of 35 to 85% by weight of the gas generant composition,

wherein said fuel is selected from the group consisting of monoguanidinium salt of 5,5′

-Bis-1H-tetrazole, diguanidinium salt of 5,5′

-Bis-1H-tetrazole, monoaminoguanidinium salt of 5,5′

-Bis-1H-tetrazole, diaminoguanidinium salt of 5,5′

-Bis-1H-tetrazole, monohydrazinium salt of 5,5′

-Bis-1H-tetrazole, dihydrazinium salt of 5,5′

-Bis-1H-tetrazole, monoammonium salt of 5,5′

-bis-1H-tetrazole, diammonium salt of 5,5-bis-1H-tetrazole, mono-3-amino-1,2,4-triazolium salt of 5,5′

-bis-1H-tetrazole, di-3-amino-1,2,4-triazolium salt of 5,5′

-bis-1H-tetrazole, diguanidinium salt of 5,5′

-Azobis-1H-tetrazole, and monoammonium salt of 5-Nitramino-1H-tetrazole.

23. The gas generating system of claim 6 wherein the gas generating system is a filterless gas generating system.

20. A vehicle occupant protection system comprising a gas generating system, the gas generating system comprising:

an outer housing including a combustion chamber, a first end, and a second end; and

an end closure coupled to the housing at said first end in a metal-to-metal seal.

21. The vehicle occupant protection system of claim 20 wherein the outer housing has a diameter of about 20 millimeters.

24. A gas generating system comprising:

an outer housing including a combustion chamber, a first end, and a second end; and

an end closure coupled to the housing at said first end in a metal-to-metal seal.

25. The gas generating system of claim 24 wherein said outer housing has an outer diameter of about 20 millimeters.

26. A method of manufacturing an inflator, the method comprising the steps of:

providing an outer housing having a first end and a second end, and a periphery;

forming an outer protrusion about the periphery at the first end;

providing an end closure having a recessed portion;

inserting the end closure withing the outer housing at the first end, thereby laterally aligning the outer protrusion and the recessed portion; and

compressing the outer protrusion within the recessed portion.

27. An inflator formed by the method of claim 26.

28. A vehicle occupant protection system containing an inflator formed by the method of claim 26.