Inflator and airbag module

Patent metadata

Field	Value
Publication number	US-9815431-B2
Application number	US-201514930870-A
Country	US
Kind code	B2
Filing date	Nov 3, 2015
Priority date	Oct 15, 2010
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

An inflator for a protective device in a vehicle includes a diffuser ( 10 ) forming a substantially rotation-symmetric external housing of the inflator with a closing member ( 12 ), wherein the diffuser ( 10 ) includes a plurality of discharge orifices ( 78 ) arranged in a row, and which are of circular shape. The inflator also includes an igniter sleeve ( 38 ) which at least partially encloses an igniter ( 34 ) and an igniter chamber ( 42 ) filled with a booster charge and is adjacent to a first combustion chamber ( 44 ) filled with fuel, wherein the igniter sleeve ( 38 ), related to a central axis B of the igniter sleeve ( 38 ), has overflow orifices ( 98 ) unevenly distributed in circumferential direction.

First claim

The invention claimed is:

1. An inflator for a protective device in a vehicle, comprising:
a diffuser forming a substantially rotation-symmetric external housing of the inflator with a closing member, wherein the diffuser includes a plurality of discharge orifices arranged in a row and which are of circular shape; and
an igniter sleeve which at least partially encloses an igniter and an igniter chamber filled with a booster charge and is adjacent to a first combustion chamber filled with fuel and; wherein the igniter sleeve includes a marker distant from a central axis (B) or extending non-symmetrically from the central axis (B) which indicates a predetermined orientation of the igniter sleeve;
a combustion chamber sleeve that surrounds a second combustion chamber;
wherein the igniter sleeve, related to the central axis (B) of the igniter sleeve, has overflow orifices unevenly distributed in a circumferential direction to define a maximum angular range (α) less than 180° such that all inflation fluid exits the igniter sleeve over an angular range less than 180°, each of the overflow orifices being directed in a direction that does not intersect the combustion chamber sleeve.

2. The inflator according to claim 1 , wherein the first combustion chamber is associated with a first activating stage of the inflator, and wherein the second combustion chamber is filled with fuel and associated with a second activating stage of the inflator, wherein both sleeves ( 60 ) are juxtaposed and are differently offset with respect to a central axis (A) of the inflator;
wherein the distance between the central axis (B) of the igniter sleeve and a central axis (C) of the combustion chamber sleeve is between 22.5 and 27.5 mm, and wherein the ratio of the minimum inner diameter (c) of the combustion chamber sleeve to the minimum inner diameter (d) of the igniter sleeve is between 1.64 and 2.63, and wherein, related to a central axis (A) of the inflator, the first combustion chamber is radially confined at least partially by an at least partly circumferential filter, the ratio of the inner diameter (f) of the filter to the minimum inner diameter (d) of the igniter sleeve ranging between 3.19 and 4.76.

3. The inflator according to claim 1 , wherein the first combustion chamber is associated with a first activating stage of the inflator, and wherein the second combustion chamber is filled with fuel and associated with a second activating stage of the inflator, wherein the combustion chamber sleeve is adjacent to the first combustion chamber which, related to a central axis (A) of the inflator, is radially confined at least partially by an at least partly circumferential filter, the ratio of the inner diameter (f) of the filter to the minimum inner diameter (c) of the combustion chamber sleeve ranging between 1.66 and 2.11;
wherein the ratio of the outer diameter (a) of the inflator to the minimum inner diameter (d) of the igniter sleeve is between 4.09 and 5.98; and
wherein the ratio of the outer diameter (a) of the inflator to the minimum inner diameter (c) of the combustion chamber sleeve is between 2.13 and 2.66.

4. The inflator according to claim 1 , further comprising a radially projecting generator flange, related to a central axis (A) of the inflator, for mounting the inflator to a support, wherein the generator flange is substantially rectangular;
wherein a ratio of a length (l) to a width (b) of the rectangle ranges between 1.12 and 1.31;
wherein a ratio of the length (l) of the rectangle to an outer diameter (a) of the external housing ranges between 1.24 and 1.48; and
wherein a ratio of the width (b) of the rectangle to the outer diameter (a) of the external housing is between 1.01 and 1.23.

5. The inflator according to claim 1 , wherein at least in portions a wall thickness of the closing member is larger than that of the diffuser, wherein the closing member has a substantially planar bottom in which at least one opening for receiving an igniter carrier is formed and that at least the bottom has a larger wall thickness than the diffuser.

6. The inflator according to claim 1 , wherein the diffuser includes a ceiling portion and the combustion chamber sleeve contacts the ceiling portion of the diffuser in a non-activated state of the inflator at least at one point, and wherein, related to a central axis (A) of the diffuser, the axial distance (g) between the combustion chamber sleeve and the ceiling portion is varying such that the maximum distance (g) between the combustion chamber sleeve and the ceiling portion of the diffuser is between 2.3 and 3.7 mm.

7. The inflator according to claim 1 , wherein the igniter sleeve is offset with respect to a central axis (A) of the diffuser whose axial distance (i) from a ceiling portion of the diffuser is varying such that the maximum distance (i) between the igniter sleeve and the ceiling portion of the diffuser is between 2.1 and 3.5 mm.

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

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

10. The inflator according to claim 1 , wherein a connecting line extends between the central axis of the igniter sleeve and the portion of the filter maximally distant from the central axis, each overflow orifice allowing inflation fluid to exit the igniter sleeve being circumferentially positioned at an acute angle relative to the connecting line.

11. The inflator according to claim 1 , wherein the igniter sleeve includes a nose or a recess as the marker and wherein the igniter sleeve has a configuration adapted to a configuration of a neighboring component of the inflator such that mounting of the igniter sleeve in the inflator is possible at the predetermined orientation only.

12. The inflator according to claim 1 , wherein an axial cross-section of the igniter sleeve including the marker is different from an axial cross-section of the igniter sleeve spaced from the marker.

13. The inflator according to claim 1 , wherein the maximum angular range (α) extends to both sides of a connecting line (x) between the central axis (B) of the igniter sleeve and the portion of the filter maximally distant from the central axis (B), wherein the angular range (α) is obtuse and ranges between 90° and 135°.

14. The inflator according to claim 13 , wherein the angular range (α) includes areas in which a distance from the filter not blocked by components of the inflator is maximal and wherein the angular range (α) encloses the combustion chamber sleeve, the second combustion chamber being at least partially surrounded by the first combustion chamber.

15. The inflator according to claim 1 , further comprising a fuel canister filled with fuel including a fuel canister bottom and a fuel canister opening opposed to the fuel canister bottom which is closed by means of a combustion chamber component.

16. The inflator according to claim 15 , wherein the second combustion chamber is associated with a particular activating stage of the inflator, wherein the combustion chamber sleeve exhibits a combustion chamber sleeve opening or an open side and a combustion chamber sleeve bottom opposed thereto which covers the fuel canister opening, wherein a second fill member connected to the combustion chamber sleeve bottom is arranged at the combustion chamber sleeve bottom; and
wherein at least part of a side wall of the fuel canister extending between the fuel canister opening and the fuel canister botto

Assignees

• 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

• B60R21/2644

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

• B60R2021/26011

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

• B60R2021/2648

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

• B60R2021/26029

  Ignitors · CPC title

• B60R21/261 Primary

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