Gas generator for a vehicle passenger protection device and process for removing solids and liquid burned residues in a gas stream

• US 20100117344A1
• Filed: 01/14/2010
• Published: 05/13/2010
• Est. Priority Date: 07/16/2007
• Status: Active Grant

• Current Assignee: Takata - Petri AG (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Takata - Petri AG (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Kratz, Heiko, Windhausen, Björn
• Granted Patent: US 7,866,692 B2
• Time in Patent Office: Days
• US Class Current: 280/737
• CPC Class Codes: B60R 2021/2648 comprising a plurality of combustion chambers or sub-chambers
• CPC Class Codes: B60R 21/261 with means other than bag structure to diffuse or guide inflation fluid
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder

Abstract

A gas generator for a vehicle passenger protection device. The gas generator includes a combustion chamber in which a gas-generating charge is arranged. A conical deposition chamber is provided that has a first wall, within which a plurality of gas through-holes are formed, and at least one second wall which extends at an angle from the first wall and within which at least one blow-off hole is formed. Gas generated inside the combustion chamber enters the deposition chamber through the gas through-holes and leaves the deposition chamber through the at least one blow-off hole.

Claims

1. A gas generator for a vehicle passenger protection device comprising:

a combustion chamber in which a gas-generating charge is arranged;

a conical deposition chamber comprising;

a first wall,

a plurality of gas through-holes formed in the first wall,

a second wall which extends at an angle from the first wall,

at least one blow-off hole formed in the second wall,

a third wall; and

a gas generator housing;

wherein the second wall is formed by a side wall of the gas generator housing;

wherein the third wall is formed by a bottom or cover area of the gas generator housing; and

wherein the gas generator is configured such that gas generated inside the combustion chamber enters the deposition chamber through the gas through-holes, the gas after streaming through the gas through-holes strikes the second wall of the deposition chamber, the gas thereby undergoing a redirection, the gas subsequently strikes the third wall of the deposition chamber, the gas thereby undergoing a further redirection, and the gas then leaves the deposition chamber through the at least one blow-off hole.

2. The gas generator according to claim 1, wherein the gas through-holes in the deposition chamber are arranged in an offset manner to the at least one blow-off hole.

3. The gas generator according to claim 1, wherein the deposition chamber is designed such that the velocity of the gas stream in the deposition chamber decreases in direction of the at least one blow off-hole.

4. The gas generator according to claim 1, wherein the deposition chamber broadens conically in direction of the at least one blow off-hole.

5. The gas generator according to claim 4, wherein all gas through-holes are arranged in an offset manner to the at least one blow-off hole, wherein the at least one blow-off hole is formed in an area of the deposition chamber which is conically broadened in respect to the area forming the gas through-holes.

6. The gas generator according to claim 1, wherein the ratio of the distance (B) of a gas through-hole to the bottom or cover area to the distance (A) of the at least one blow off-hole to the bottom or cover area is in each case larger or equal to 1.5.

7. The gas generator according to claim 1, wherein the gas through-holes of the first wall are formed by holes, elongated holes or dormers.

8. The gas generator according to claim 1, wherein the gas through-holes in the first wall are formed such that gas stream streams out of the first wall essentially in tangential direction into the deposition chamber.

9. The gas generator according to claim 8, wherein the first wall is pivotable mounted in such a manner that the first wall starts to rotate due to the tangential gas discharge.

10. The gas generator according to claim 1, wherein the cross-sectional area of the gas through-holes is larger than the cross-sectional area of the blow off-holes.

11. The gas generator according to claim 1, wherein the cross section of the blow off-holes is determined such that the gas velocity in the blow off-holes is greater than or equal to the sonic speed.

12. The gas generator according to claim 1, wherein the first wall is part of the combustion chamber, defines a boundary of the combustion chamber and is arranged outside of the combustion chamber.

13. A process for depositing solids and liquid burned residues of a gas stream of a gas generator, comprising the steps of:

passing a gas stream through the conically formed deposition chamber, and

wherein the gas stream after passing gas through-holes of a first wall of the deposition chamber strikes a second wall of the deposition chamber, thereby undergoing a redirection, subsequently strikes a third wall of the deposition chamber, thereby undergoing a further redirection, and then leaves the deposition chamber through the at least one blow off-hole.

14. The process according to claim 13, wherein the gas stream undergoes after the first redirection a pressure drop caused by the conicity of the deposition chamber, wherein the velocity of the gas stream is reduced.

15. The process according to claim 13, wherein the gas stream is made to rotate around a rotation axis.

16. A gas generator for a vehicle passenger protection device comprising:

a combustion chamber in which a gas-generating charge is arranged;

a conical deposition chamber comprising;

a first wall,

a plurality of gas through-holes formed in the first wall,

a second wall which extends at an angle from the first wall, and

at least one blow-off hole formed in the second wall;

wherein the gas generator is configured such that gas generated inside the combustion chamber enters the deposition chamber through the gas through-holes and leaves the deposition chamber through the at least one blow-off hole;

wherein the gas through-holes are formed such in the first wall that the gas streams out of the first wall essentially in tangential direction into the deposition chamber; and

wherein the first wall is pivotally mounted and configured to rotate when gas streams out of the first wall essentially in tangential direction.

17. A gas generator for a vehicle passenger protection device comprising:

a combustion chamber in which a gas-generating charge is arranged;

a conical deposition chamber comprising;

a first wall,

a plurality of gas through-holes formed in the first wall,

a second wall which extends at an angle from the first wall, and

at least one blow-off hole formed in the second wall;

wherein the cross-sectional area of the gas through-holes is larger than the cross-sectional area of the at least one blow off-hole; and

wherein the gas generator is configured such that gas generated inside the combustion chamber enters the deposition chamber through the gas through-holes and leaves the deposition chamber through the at least one blow-off hole.