Gas generator for an air bag

• US 5,259,643 A
• Filed: 01/21/1992
• Issued: 11/09/1993
• Est. Priority Date: 01/19/1991
• Status: Expired due to Fees

• Current Assignee: Dynamit Nobel AG
• Original Assignee: Dynamit Nobel AG
• Inventors: Winkler, Hans, Kraft, Josef, Scheiderer, Gerrit
• Primary Examiner(s): Tyson, Karin L.
• Application Number:
  US07/822,668
• Time in Patent Office: 658 Days
• Field of Search: 280/736, 280/740, 280/741, 280/742, 280/738, 422/164, 422/165, 422/166, 102/530, 102/531, 102/202.5, 102/470, 102/202.9, 55/485, 55/511
• US Class Current: 280/740
• CPC Class Codes: B60R 2021/26076 characterised by casing
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder
• CPC Class Codes: B60R 21/30 with means to draw ambient air into the flow line and mix such air with the inflation fluid

Abstract

A gas generator is provided with a housing which is open at two opposing end faces and a housing wall in which several gas orifices are arranged. The housing is formed as an extruded hollow profile of aluminum or an aluminum alloy. A combustion chamber is accommodated in the housing, in which combustion chamber gas-generating material which is ignitable by means of an ignition unit is accommodated. The combustion gases arising with the ignition of the gas-generating material are cleaned within the housing by filter elements and discharged by means of the gas orifices. The filter elements are supported by holding sections integral with the extruded hollow profile and are inserted by means of one of the open end faces of the extruded hollow profile. In the installed state the filter elements extend in a straight line between the holding sections associated therewith.

Claims

1. A gas generator, in particular a generator for an air bag of a vehicle comprising:

a housing which is open at two opposing end faces and which has an outer wall with at least one gas orifice for discharging of cleaned combustion gases;

two cover elements for closing the end faces of the housing;

a combustion chamber for receiving and burning gas-generating material ignitable by means of an ignition unit located therein, said chamber being arranged in the housing and having at least one outlet orifice in a wall of the chamber for discharging of combustion gases; and

at least one filter element arranged in the housing, each filter element having several wire mesh mats for cleaning the combustion gases flowing therethrough, characterized in that

the housing is formed as a longitudinally extruded hollow profile of aluminium or an aluminium alloy manufactured in an extrusion process, the extruded hollow profile has integral intermediate walls for deflecting the combustion-gas flow, said intermediate walls projecting into a discharge chamber between the outlet orifice of the combustion chamber and the gas orifice of the housing, and the extruded hollow profile as integral holding sections for each filter element opposing one another and extending a length of the housing, between which holding sections a filter element can be inserted by means of one of the open end faces of the extruded hollow profile, with the wire mesh mats extending the length of the housing in a straight line between the holding sections.

2. A gas generator according to claim 1, characterized in that a discharge chamber is formed between the outlet orifice of the combustion chamber and the gas orifice for the combustion-gas flow, the holding sections being arranged in the discharge chamber.

3. A gas generator according to claim 1 or claim 2, characterized in that holding sections for several filter elements are provided, with clear mesh widths of the wire mesh mats of the several filter elements being different.

4. A gas generator according to claim 3, characterized in that the filter elements are arranged so that the filter elements are staggered and/or rotated relative to one another.

5. A gas generator according to claim 1, characterized in that a separator element is arranged in the region of a deflection of the combustion-gas flow, the separator element consisting of several wire mesh mats arranged on top of one another and acting to collect particles and/or condensed drops of liquid transported along by the combustion-gas flow.

6. A gas generator according to claim 5, characterized in that the separator element is arranged so that it abuts an inner surface of the outer wall of the housing and is supported by the inner surface.

7. A gas generator according to claim 6, characterized in that the inner surface of the outer wall of the housing in the area butting the separator element is provided with recesses for receiving particles and/or condensed drops of liquid penetrating the separator element.

8. A gas generator according to claim 1, characterized in that the extruded profile of the housing has several through passages, also produced during the manufacture of the extruded profile, for receiving fastening screws for fastening the cover elements to the end faces of the extruded profile.

9. A gas generator according to claim 1, characterized in that the combustion chamber is a separate tubular element, having open ends, said tubular element being inserted by means of one of the open ends of the housing into a receiving through passage formed in the extruded profile, and closable by the cover elements or by separate covers at its ends like the open end faces of the housing.

10. A gas generator according to claim 1, characterized in that the ignition unit is arranged at one of the end faces of the combustion chamber and is supported by an accompanying cover element of the housing.

11. A gas generator according to claim 10, characterized in that the ignition unit comprises a flame-guiding tube having openings in a tube wall, said tube being plunged into the gas-generating material.

12. A gas generator, in particular a generator for an air bag of a vehicle comprising:

a housing which is open at two opposing end faces and which has an outer wall with at least one gas orifice for discharging of cleaned combustion gases;

two cover elements for closing the end faces of the housing;

a combustion chamber for receiving and burning gas-generating material ignitable by means of an ignition unit located therein, said chamber being arranged in the housing and having at least one outlet orifice in a wall of the chamber for discharging of combustion gases; and

at least one filter element arranged in the housing, each filter element having several wire mesh mats for cleaning the combustion gases flowing therethrough,

characterized in that

the housing is formed as an extruded hollow profile of aluminium or an aluminium alloy manufactured in an extrusion process and

the extruded hollow profile has integral holding sections for each filter element opposing one another, between which holding sections a filter element can be inserted by means of one of the open end faces of the extruded hollow profile, with the wire mesh mats extending in a straight line between the holding sections and the holding sections are formed as U-shaped grooves integral with the outer wall of the housing, the grooves embracing a filter element laterally.

13. A gas generator according to claim 12, characterized in that holding sections are formed at the intermediate walls and on the inner surface of the outer wall of the housing, with the outer wall of the housing having a U-shaped first groove on the inner surface and an end of an intermediate wall facing this first groove likewise having a U-shaped second groove which extends in parallel with the first groove.

14. A gas generator according to claim 13, characterized in that the holding sections of a filter element have a predetermined breaking point for releasing the filter element from the holding section upon the occurrence of a gas pressure exceeding of a certain predetermined combustion-gas pressure acting on the filter element.

15. A gas generator according to claim 13 or 14, characterized in that one of the side-wall sections of the U-shaped grooves on the inner surface of the outer wall of the housing and/or the intermediate wall has a region of reduced wall thickness.

16. A gas generator, in particular a generator for an air bag of a vehicle comprising:

a housing which is open at two opposing end faces and which has an outer wall with at least one gas orifice for discharging of cleaned combustion gases;

two cover elements for closing the end faces of the housing;

a combustion chamber for receiving and burning gas-generating material ignitable by means of an ignition unit located therein, said chamber being arranged in the housing and having at least one outlet orifice in a wall of the chamber for discharging of combustion gases; and

at least one filter element arranged in the housing, each filter element having several wire mesh mats for cleaning the combustion gases flowing therethrough, characterized in that

the housing is formed as a longitudinally extruded hollow profile of a aluminium or an aluminium alloy manufactured in an extrusion process, the extruded hollow profile has integral holding sections for each filter element opposing one another and extending a length of the housing, between which holding sections a filter element can be inserted by means of one of the open end faces of the extruded hollow profile, with the wire mesh mats extending the length of the housing in a straight line between the holding sections, and an inner surface of the outer wall of the housing in the area of a discharge chamber attached to the outlet orifice of the combustion chamber has several receiving pockets open towards an outlet orifice for particles and/or condensed drops of liquid transported along by the combustion-gas flow.

17. A gas generator according to claim 16, characterized in that the receiving pockets are formed by flanges which project inwardly, are directed to the outlet orifice at least in the end region and are integral with the housing wall.

18. A gas generator, in particular a generator for an air bag of a vehicle comprising:

a housing which is open at two opposing end faces and which has an outer wall with at least one gas orifice for discharging of cleaned combustion gases;

two cover elements for closing the end faces of the housing;

a combustion chamber for receiving and burning gas-generating material ignitable by means of an ignition unit located therein, said chamber being arranged in the housing and having at least one outlet orifice in a wall of the chamber for discharging of combustion gases; and

at least one filter element arranged in the housing, each filter element having several wire mesh mats for cleaning the combustion gases flowing therethrough, characterized in that

the housing is formed as a longitudinally extruded hollow profile of a aluminium or an aluminium alloy manufactured in an extrusion process, the extruded hollow profile has integral holding sections for each filter element opposing one another and extending a length of the housing, between which holding sections a filter element can be inserted by means of one of the open end faces of the extruded hollow profile, with the wire mesh mats extending the length of the housing in a straight line between the holding sections, and the combustion chamber is an integral component of the extruded hollow profile of the housing, with the outlet orifice of the combustion chamber being formed as a slot extending over the entire length of the extruded profile.

19. A gas generator, in particular a generator for an air bag of a vehicle comprising:

a housing which is open at two opposing end faces and which has an outer wall with at least one gas orifice for discharging of cleaned combustion gases;

two cover elements for closing the end faces of the housing;

a combustion chamber for receiving and burning gas-generating material ignitable by means of an ignition unit located therein, said chamber being arranged in the housing and having at least one outlet orifice in a wall of the chamber for discharging of combustion gases; and

at least one filter element arranged in the housing, each filter element having several wire mesh mats for cleaning the combustion gases flowing therethrough,

characterized in that

the housing is formed as an extruded hollow profile of aluminium or an aluminium alloy manufactured in an extrusion process, and

the extruded hollow profile has integral holding sections for each filter element opposing one another, between which holding sections a filter element can be inserted by means of one of the open end faces of the extruded hollow profile, with the wire mesh mats extending in a straight line between the holding sections and at the outer surface of an outer wall of the housing in the area of the combustion chamber two projecting holding projections integral with the extruded profile, having symmetrical recesses facing each other, are provided and in that by means of one of the end faces of the extruded profile a support element for the ignition unit can be inserted into the recesses, the support element extending between them, with the ignition unit in the installed state extending through two openings, which are in alignment with one another, in the outer wall of the housing and the combustion chamber or, with integral construction of housing and combustion chamber, through an opening in the outer wall of the housing into the combustion chamber.

20. A gas generator, in particular a generator for an air bag of a vehicle comprising:

a housing which is open at two opposing end faces and which has an outer wall with at least one gas orifice for discharging of cleaned combustion gases;

two cover elements for closing the end faces of the housing;

a combustion chamber for receiving and burning gas-generating material ignitable by means of an ignition unit located therein, said chamber being arranged in the housing and having at least one outlet orifice in a wall of the chamber for discharging of combustion gases; and

at least one filter element arranged in the housing, each filter element having several wire mesh mats for cleaning the combustion gases flowing therethrough,

characterized in that

the housing is formed as an extruded hollow profile of aluminium or an aluminium alloy manufactured in an extrusion process, and the extruded hollow profile has integral holding sections for each filter element opposing one another, between which holding sections a filter element can be inserted by means of one of the open end faces of the extruded hollow profile, with the wire mesh mats extending in a straight line between the holding sections and several gas orifices are arranged in a row in a longitudinal direction of the extruded profile of the housing and in that at both longitudinal sides of the row of gas orifices there are arranged outwardly projecting curved edge sections integral with the extruded profile, the edge sections forming a nozzle operating after the gas orifices.

21. A gas generator according to claim 20, characterized in that the edge sections of the outer wall of the housing forming the nozzle define a slot and project slightly into the inside of the housing and in that a perforated strip provided with several holes is provided, which has turned-up longitudinal edges with hook-shaped ends to embrace the inwardly projecting areas of the edge sections and can be slipped on by means of one of the end faces of the extruded profile.

22. A gas generator according to claim 20 or 21, characterized in that to improve the entraining of ambient air as a consequence of the combustion-gas flowing out of the nozzle in the area of the nozzle air-guiding plates which are connected as one piece to the housing and are arranged at a distance to these are provided, extending over the entire length of the extruded profile of the housing, with through openings being formed for drawing in the ambient air in the connection area between housing and air-guiding plates.

23. A housing for a gas generator, especially for an air bag gas generator which comprises:

a housing which is open at two opposite ends, said housing body having a housing wall with at least one gas outlet opening therein, and

a combustion chamber which is located in the housing body to receive and burn gas-generating material and which has at least one outlet opening, characterized in that the housing is made in the form of a longitudinally extruded hollow profile produced by an extrusion-molding process from aluminum or an aluminum alloy, and the extruded hollow profile has integrated holding or retaining sections opposite one another adapted to receive at least one filter element and between which the at least one filter element is insertable through one of the open ends of the extruded profile;

said holding or retaining sections extending an entire length of the profile, said housing body including a through chamber for combustion gas flow formed between the at least one outlet opening of the combustion chamber and the at least one gas outlet opening, said holding sections being located in said through chamber and said extruded profile having partitions to deflect the combustion gas stream, integrated and projecting into the through chamber between the at least one outlet opening of the combustion chamber and the at least one gas outlet opening.

24. A housing for a gas generator, especially for an air bag gas generator which comprises:

a housing which is open at two opposite ends, said housing body having a housing wall with at least one gas outlet opening therein, and

a combustion chamber which is located in the housing body to receive and burn gas-generating material and which has at least one outlet opening, characterized in that the housing body is made in the form of an extruded hollow profile produced by an extrusion-molding process from aluminum or an aluminum alloy, and the extruded hollow profile has integrated holding or retaining sections opposite one another adapted to receive at least one filter element and between which the at least one filter element is insertable through one of the open ends of the extruded hollow profile and the holding sections are in the form of U-shaped grooves integrated in a housing outside wall to grasp laterally at least one filter element.

25. A housing according to claim 24, characterized in that the holding sections are formed on the partitions and an inner surface of the housing outside wall, with the housing outside wall having a U-shaped first groove on the inner surface and an end of a partition facing this first groove likewise having a U-shaped second groove, running parallel to the first groove.

26. A housing according to claim 24, characterized in that one of the side wall sections of the U-shaped grooves on the inner surface of housing outside wall and/or the partition has an area of reduced wall thickness.

27. A housing according to claim 24, characterized in that the holding sections for a filter element have a prescored location to release filter element from the retaining sections if a combustion gas pressure acting on a filter element exceeds a predetermined pressure.

28. A housing for a gas generator, especially for an air bag gas generator which comprises:

a housing which is open at two opposite ends, said housing body having a housing wall with at least one gas outlet opening therein, and

a combustion chamber which is located in the housing body to receive and burn gas-generating material and which has at least one outlet opening, characterized in that

the housing body is made in the form of a longitudinally extruded hollow profile produced by an extrusion-molding process from aluminum or an aluminum alloy, and the extruded hollow profile has integrated holding or retaining sections opposite one another adapted to receive at least one filter element and between which the at least one filter element is insertable through one of the open ends of the extruded hollow profile;

said holding or retaining sections extending an entire length of the profile and an inner surface of an outside wall of the housing body in an area of the through chamber abutting an outlet opening of combustion chamber has a plurality of receiving pockets open toward the outlet opening for particles and/or condensed liquid drops entrained by the combustion gas flow.

29. A housing according to claim 28, characterized in that the receiving pockets are formed by inwardly projecting ribs integrated in a housing wall, said ribs being oriented toward an outlet opening at least in an end area.

30. A housing for a gas generator, especially for an air bag gas generator which comprises:

a housing which is open at two opposite ends, said housing body having a housing wall with at least one gas outlet opening therein, and

a combustion chamber which is located in the housing body to receive and burn gas-generating material and which has at least one outlet opening, characterized in that the housing body is made in the form of a longitudinally extruded hollow profile produced by an extrusion-molding process from aluminum or an aluminum alloy, and the extruded hollow profile has integrated holding or retaining sections opposite one another adapted to receive at least one filter element in between which the at least one filter element is insertable through one of the open ends of the extruded profile;

said holding or retaining sections extending an entire length of the profile;

the combustion chamber being an integral component of the extruded hollow profile, with the at least one opening of combustion chamber being in the form of a slot extending over an entire length of the extruded hollow profile.

31. A housing according to claim 30, characterized in that two projecting retaining projections are integrated into the extruded hollow profile and symmetrical recesses facing one another are provided on an outer surface of a housing outside wall in the vicinity of the combustion chamber, and a supporting element for an ignition unit is insertable through one of the ends of the extruded hollow profile into the recesses, said supporting element extending between said recesses, with the ignition unit in the installed state extending through two mutually flush openings in the housing outside wall and the combustion chamber or, with an integral design of the housing body and combustion chamber, through an opening in the housing outside wall into the combustion chamber.

33. A housing according to claim 31, characterized in that a plurality of gas outlet openings are provided along the length of the extruded hollow profile and outwardly projecting curved marginal sections integrated into the extruded profile are provided on both long sides of a row of gas outlet openings, said marginal sections forming a nozzle downstream from the gas outlet openings.

34. A housing according to claim 33, characterized in that edge sections of a housing outside wall forming the nozzle delimit a slot and project slightly into the interior of the housing, and a hole-containing strip provided with a plurality of holes is provided, said strip having elevated lengthwise edges with hook-shaped ends to fit over the inwardly projecting areas of the marginal sections, and being pushable over one of the ends of the extruded profile.

35. A housing according to claim 34, characterized in that air guide plates are provided to improve the entrainment of ambient air as the result of the combustion gas flowing out of the nozzle in the vicinity of the nozzle, said plates being connected integrally with the extruded profile and located at a distance therefrom, said plates extending over the entire length of the extruded profile and through holes adapted to suck in the ambient air being provided in a connecting area between the extruded profile and the air guide plates.

32. A housing for a gas generator, especially for an air bag gas generator which comprises:

a housing which is open at two opposite ends, said housing body having a housing wall with at least one gas outlet opening therein, and

a combustion chamber which is located in the housing body to receive and burn gas-generating material and which has at least one outlet opening, characterized in that the housing body is made in the form of a longitudinally extruded hollow profile produced by an extrusion-molding process from aluminum or an aluminum alloy, two projecting retaining projections are integrated into the extruded hollow profile and symmetrical recesses facing one another are provided on an outer surface of a housing outside wall in the vicinity of the combustion chamber, and a supporting element for an ignition element is inserted through one of the ends of the extruded hollow profile into the recesses, said supporting element extending between said recesses, with the ignition unit in the installed state extending through two mutually flush openings in the housing outside wall and the combustion chamber or, with an integral design of the housing body and combustion chamber, through an opening in the housing outside wall into the combustion chamber, and the extruded hollow profile has integrated holding or retaining sections opposite one another adapted to receive at least one filter element and between which the at least one filter element is insertable through one of the open ends of the extruded hollow profile;

said holding or retaining sections extending an entire length of the profile.