Gas generator and airbag module

Patent metadata

Field	Value
Publication number	US-9452729-B2
Application number	US-201113878827-A
Country	US
Kind code	B2
Filing date	Sep 27, 2011
Priority date	Oct 15, 2010
Publication date	Sep 27, 2016
Grant date	Sep 27, 2016

Abstract

An inflator, especially for a protective device in a vehicle, includes a diffuser ( 10 ) which preferably forms a substantially rotation-symmetric external housing of the inflator with a closing member ( 12 ). The diffuser ( 10 ) includes more than 12, preferably more than 14, further preferably 23 discharge orifices ( 78 ) arranged in a row. Moreover, the inflator exhibits a plurality of further peculiarities.

First claim

The invention claimed is:

1. An inflator for a protective device in a vehicle and having a central axis A, comprising
a diffuser ( 10 ) cooperating with a closing member ( 12 ) to form an external housing of the inflator that is symmetric about the central axis A, wherein the diffuser ( 10 ) includes more than 12 circular discharge orifices ( 78 ) arranged in a single row, the discharge orifices ( 78 ) having different first, second, and third flow cross-sections and that in the row of the discharge orifices ( 78 ) at least partially a recurring sequence of the first flow cross-section→second flow cross-section→first flow cross-section→third flow cross-section is provided, wherein the first flow cross-section is small, the second flow cross-section is medium and the third flow cross-section is large.

2. The inflator according to claim 1 , wherein a ratio of an outer circumference of the diffuser ( 10 ) in mm to a number n of the discharge orifices ( 78 ) in the row is less than 16.5, and wherein the diffuser ( 10 ) includes a ring-shaped fixation flange that surrounds the central axis A.

3. The inflator according to claim 1 , wherein diametrically opposed discharge orifices ( 78 ) have equal flow cross-sections, and wherein directly neighboring discharge orifices ( 78 ) have different flow cross-sections.

4. The inflator according to claim 1 , wherein the row includes a number n of discharge orifices ( 78 ) and extends in a circumferential direction about the central axis A, the row having a beginning with a first discharge orifice ( 78 a ) and an end with a last discharge orifice ( 78 b ) and an angular distance (ad) between neighboring discharge orifices ( 78 ) being determined by the equation:
ad= 360°/( n+ 1).

5. The inflator according to claim 1 , further comprising a combustion chamber sleeve ( 60 ) which at least partially encloses a combustion chamber ( 56 ) filled with fuel, wherein the combustion chamber sleeve ( 60 ) changes shape under the influence of pressure formed during combustion of the fuel so as to release a discharge orifice ( 112 ) leading out of the combustion chamber ( 56 ) into a further combustion chamber ( 44 ) of the inflator for a combustion gas formed during combustion of the fuel.

6. The inflator according to claim 1 , further comprising an igniter sleeve ( 38 ) at least partially enclosing an igniter ( 34 ) and an igniter chamber ( 42 ) filled with a booster charge, wherein the igniter sleeve ( 38 ) is adjacent to a first combustion chamber ( 44 ) associated with a first activating stage of the inflator, a combustion chamber sleeve ( 60 ) at least partially enclosing a second combustion chamber ( 56 ) filled with fuel and associated with a second activating stage of the inflator, wherein each sleeve ( 38 , 60 ) is spaced a different distance from the central axis A of the inflator, and wherein a distance between a central axis B of the igniter sleeve ( 38 ) and a central axis C of the combustion chamber sleeve ( 60 ) is between 22.5 and 27.5 mm, and wherein a ratio of a minimum inner diameter c of the combustion chamber sleeve to a minimum inner diameter d of the igniter sleeve is between 1.64 and 2.63, and wherein a filter ( 46 ) at least partly encircles the first combustion chamber ( 44 ), a ratio of an inner diameter f of the filter ( 46 ) to a minimum inner diameter d of the igniter sleeve ( 38 ) ranging between 3.19 and 4.76.

7. The inflator according to claim 1 , further comprising an igniter sleeve ( 38 ) at least partially enclosing an igniter ( 34 ) and an igniter chamber ( 42 ) filled with a booster charge, wherein the igniter sleeve ( 38 ) is adjacent to a first combustion chamber ( 44 ) associated with a first activating stage of the inflator, a combustion chamber sleeve ( 60 ) at least partially enclosing a second combustion chamber ( 56 ) filled with fuel and associated with a second activating stage of the inflator, wherein the combustion chamber sleeve ( 60 ) is adjacent to the first combustion chamber ( 44 ), wherein a filter ( 46 ) at least partly encircles the first combustion chamber ( 44 ), a ratio of an inner diameter f of the filter ( 46 ) to a minimum inner diameter c of the combustion chamber sleeve ( 60 ) ranging between 1.66 and 2.11, and wherein a ratio of an outer diameter a of the inflator to a minimum inner diameter d of the igniter sleeve ( 38 ) is between 4.09 and 5.98 and wherein a ratio of an outer diameter a of the inflator to a minimum inner diameter c of the combustion chamber sleeve ( 60 ) is between 2.13 and 2.66.

8. The inflator according to claim 1 , comprising a filter ( 46 ) and a combustion chamber sleeve ( 60 ) at least partially enclosing a combustion chamber ( 56 ), wherein the filter ( 46 ) extends in a ring-shaped manner about the combustion chamber ( 56 ) and includes a critical filter portion ( 120 ) which is closer to the combustion chamber sleeve ( 60 ) than the remaining filter ( 46 ) and has a reduced thickness compared to areas of the filter ( 46 ) adjacent to the critical filter portion ( 120 ).

9. The inflator according to claim 1 , further comprising a circumferential wall ( 16 , 22 ) which surrounds a combustion chamber ( 44 ) and a filter ( 46 ) which extends at least partially along the wall ( 16 , 22 ), wherein the wall ( 16 , 22 ) has at least one supporting portion ( 124 ) which constitutes an axial support for the filter ( 46 ) and is integrally formed with the wall ( 16 , 22 ), and wherein either plural supporting portions ( 124 ) are formed by embossed beads spaced apart from each other in a circumferential direction about the central axis A or a single supporting portion ( 124 ) is formed by a completely circumferential embossed bead.

10. The inflator for a protective device in a vehicle and according to claim 1 , further comprising a first combustion chamber ( 44 ) filled with fuel which is associated with a first activating stage of the inflator, the first combustion chamber ( 44 ) being closed on one side by the diffuser ( 10 ), wherein a silicone first fill member ( 52 ; 82 ) is disposed between the fuel and the diffuser ( 10 ), wherein the first fill member ( 52 ; 82 ) has a pair of differently sized circular recess ( 116 , 118 ) for receiving an igniter sleeve ( 38 ) associated with the first activating stage of the inflator and a combustion chamber sleeve ( 60 ) associated with a second activating stage of the inflator, wherein the igniter sleeve ( 38 ) projects into a smaller of the recesses ( 116 , 118 ) and the combustion chamber sleeve ( 60 ) projects into a larger of the recesses ( 116 , 118 ), wherein a ratio of a diameter of the larger recess ( 118 ) to a diameter of the smaller recess ( 116 ) is between 1.52 and 2.25, and wherein the first fill member ( 82 ) is formed in at least two partial members ( 114 ) having the shape of a double half moon.

11. The inflator according to claim 1 , wherein at least in portions a wall thickness of the closing member ( 12 ) is greater than a wall thickness of the diffuser ( 10 ), wherein the closing member ( 12 ) includes a substantially planar bottom ( 20 ) having a greater wall thickness than the diffuser ( 10 ) and in which at least one opening ( 24 ) for receiving an igniter carrier ( 30 , 32 ) is formed.

12. An airbag module for a vehicle comprising an airbag having a volume of 40 to 60 liters, comprising an inflator according to claim 1 .

13. An airbag module for a vehicle comprising an airbag having a volume of 60 to 135 liters, comprising an inflator according to claim 1 .

14. The inflator according to claim 1 , further comprising an igniter unit ( 26 , 28 ) having a marker ( 90 ),

Assignees

• Bierwirth Sebastian
• Hofmann Achim
• Neumayer Hans-Peter
• Spitzenberger Dieter
• Nuiding Hannes
• Schober Thomas
• Bommer Josef
• Breddermann Tobias
• Schwebel Dietmar
• Trw Airbag Sys Gmbh

Inventors

• Bierwirth Sebastian
• Hofmann Achim
• Neumayer Hans-Peter
• Spitzenberger Dieter
• Nuiding Hannes
• Schober Thomas
• Bommer Josef
• Breddermann Tobias
• Schwebel Dietmar

Classifications

• B60R2021/2648

  comprising a plurality of combustion chambers or sub-chambers · CPC title

• B60R2021/26011

  using a filter through which the inflation gas passes · CPC title

• B60R21/2644

  using only solid reacting substances, e.g. pellets, powder · CPC title

• B60R21/264

  using instantaneous generation of gas, e.g. pyrotechnic (B60R21/268 takes precedence) · CPC title

• B60R21/261 Primary

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