ASSEMBLY GROUP CONSISTING OF A CAP OF A TUBULAR GAS GENERATOR AND A DEFLECTOR ELEMENT, TUBULAR GAS GENERATOR AND METHOD FOR MANUFACTURING A TUBULAR GAS GENERATOR

Abstract

In an assembly group comprising a cap of a tubular gas generator and a deflector element that deflects gas flowing out of at least one outflow opening of the cap to at least one discharge opening of the deflector element, a deflection surface of the deflector element is arranged radially outwardly of the outflow opening. At least two securing arms of the deflector element extend through the outflow opening and engage behind an edge defining the outflow opening on an inside in a positive connection with the cap. The cap is fixed firmly to an axial end of the tubular gas generator. Subsequently, the deflector element is slid from an outside of the cap with its securing arms through the outflow opening, the securing arms forming a positive connection with the edge of the outflow opening which fixes the deflector element firmly to the cap.

Claims

1. An assembly group comprises a cap of a tubular gas generator and a deflector element that deflects gas flowing out of at least one outflow opening of the cap to at least one discharge opening of the deflector element, wherein a deflection surface of the deflector element is arranged radially outwardly of the outflow opening and at least two securing arms of the deflector element extend through the outflow opening and engage behind an edge defining the outflow opening in a positive connection with the cap on the inside.

2. The assembly group according to claim 1, wherein the positive connection is a click-lock and/or a bayonet lock.

3. The assembly group according to claim 1, wherein free ends of the securing arms are bent and are adjacent to the edge of the outflow opening on an inner face of a wall of the cap.

4. The assembly group according to claim 1, wherein the deflection surface is curved or grooved.

5. The assembly group according to claim 1, wherein lateral faces of the deflection surface extend on both sides of a crown line of the deflection surface, the crown line extending in an axial direction of the cap.

6. The assembly group according to claim 5, wherein the lateral faces merge into the securing arms.

7. The assembly group according to claim 1, wherein the deflector element is made from a formed sheet metal.

8. The assembly group according to claim 1, wherein the securing arms are biased so as to extend away from each other against the edge of the outflow opening and/or act upon the latter.

9. The assembly group according to claim 1, wherein the deflector element has an elongate shape and is open at both of its axial ends so that a discharge opening is formed at each axial end.

10. The assembly group according to claim 9, wherein cross-sectional areas of the two discharge openings are different.

11. The assembly group according to claim 1, wherein a filter is interposed between the outflow opening of the cap and the at least one discharge opening of the deflector element.

12. The assembly group according to claim 1, wherein at least two outflow openings are separated from each other by a central web and the deflector element includes at least four securing arms, wherein two adjacent securing arms act on both sides of the central web upon the edge of the respective outflow opening.

13. A tubular gas generator comprising at least one gas outlet opening provided at an axial end and an assembly group according to claim 1, wherein the cap is fixed to the tubular gas generator while it encompasses the axial end, and a collecting chamber is formed between the at least one gas outlet opening and the cap through which gas flows toward the deflector element.

14. A method for manufacturing a tubular gas generator, comprising the following steps: firmly fixing a cap to an axial end of a tubular gas generator, sliding a deflector element from an outer side of the cap with securing arms of the deflector element through an outflow opening of the cap, wherein the securing arms form a positive connection with an edge of the outflow opening which fixes the deflector element firmly to the cap.

15. The method according to claim 14, wherein the securing arms are initially moved toward each other, before the securing arms are slid into the outflow opening, by application of force while being elastically deformed, and wherein the force is removed from the securing arms such that the securing arms spring apart.

16. The method according to claim 14, wherein the securing arms are initially moved into a first orientation and slid into the outflow opening and then the securing arms are subsequently rotated by a predetermined angle into a second orientation while forming a bayonet lock.

17. The assembly group according to claim 1, wherein the cap surrounds a diffusor at a distance.

18. The assembly group according to claim 1, wherein lateral sides on both sides of the securing arms are formed into a circumferentially closed tube, wherein a cavity of the deflector element is convexly curved as a whole away from a circumferential wall of the cap.

19. The assembly group according to claim 2, wherein the securing arms are biased so as to extend away from each other against the edge of the outflow opening and/or act upon the latter.

20. The assembly group according to claim 12, wherein the securing arms are biased so as to extend away from each other against the edge of the outflow opening and/or act upon the latter.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0074] In the following, the disclosure will be described in detail by with respect to the attached figures that depict multiple exemplary arrangements, wherein:

[0075] FIG. 1 shows a schematic perspective view of an assembly group according to the disclosure that comprises a cap and a deflector element according to a first exemplary arrangement, prior to assembly to a tubular gas generator;

[0076] FIG. 2 shows a schematic longitudinal section across the assembly group of FIG. 1;

[0077] FIG. 3 shows a schematic cross-sectional view of the assembly group of FIG. 1;

[0078] FIG. 4 shows a schematic longitudinal section across an alternative exemplary arrangement of the assembly group of FIG. 1;

[0079] FIG. 5 shows a schematic longitudinal section across a further exemplary arrangement of the assembly group of FIG. 1;

[0080] FIG. 6 shows a schematic longitudinal section across yet a further exemplary arrangement of the assembly group of FIG. 1;

[0081] FIG. 7 shows a schematic longitudinal section across yet another exemplary arrangement of the assembly group of FIG. 1;

[0082] FIG. 8 shows a tubular gas generator according to the exemplary arrangement comprising an assembly group according to the disclosure mounted thereon and comprising a cap and a deflector element in a schematic perspective view;

[0083] FIG. 9 shows the assembly group of FIG. 8 in a schematic perspective view;

[0084] FIG. 10 shows the assembly group of FIG. 9 in a schematic cross-sectional view;

[0085] FIG. 11 shows the assembly group of FIG. 9 in a schematic longitudinal section; and

[0086] FIG. 12 shows the deflector element of the assembly group of FIG. 9 in a schematic perspective view.

DETAILED DESCRIPTION

[0087] FIGS. 1 to 3 illustrate an assembly group 10 for being mounted on a tubular gas generator 12 (see FIG. 8). The assembly group 10 in this exemplary arrangement comprises a cap 14 and a deflector element 16.

[0088] In the exemplary arrangement depicted, the cap 14 is a rotationally symmetric tubular component having an open end 18 and an, e.g., hemispherical closed end 20. The open end 18 is provided to be fixed to an axial end 22 of the tubular gas generator 12, such as to the circumferential wall thereof, in a firm and particularly gastight manner. This connection can be made by roller-burnishing, crimping, flaring or welding, for example.

[0089] At the axial end 22, the tubular gas generator 12 has a diffusor 23 separately plotted here having a plurality of gas outlet openings 25 distributed over the circumference thereof through which, upon activation, the gas exits the tubular gas generator 12, see FIG. 8. The diffusor 23 is firmly connected to the outer housing of the tubular gas generator 12 and forms a prefabricated unit with the tubular gas generator 12. The diffusor 23 can be considered virtually as a kind of axial extension of the tubular gas generator 12.

[0090] The cap 14 is slid over the axial end 22 of the tubular gas generator 12 so that the diffusor 23 is arranged in an interior 24 of the cap 14 at a distance from a wall, in this case a circumferential wall 26, and from the closed end 20 of the cap 14. Thus, a collecting chamber into which the gas exiting the diffusor 23 flows is formed between the outer side of the diffusor 23 and the inner side of the circumferential wall 26.

[0091] In a different variant, no diffusor is provided. In this case, the collecting chamber is formed directly between a circumferential wall of the tubular gas generator 12 in which at least one gas outlet opening 25 is provided, and the circumferential wall 26 of the cap 14. Then the assembly group 10 also adopts the function of a diffusor for directing and distributing the gas flowing out of the axial end 22 of the tubular gas generator 12. It is equally possible that the at least one gas outlet opening constitutes the open axial end 22 of the tubular gas generator 12 itself or the respective opening resulting from an open tube as outer housing at said end.

[0092] An outflow opening 28 is provided in the circumferential wall 26 of the cap 14. In the example of each of the FIGS. 1 to 3, the cap 14 has only one single outflow opening 28, but variants having plural outflow openings 28 are also conceivable (see also FIG. 7).

[0093] The outflow opening 28 in this case has a rectangular surface area, wherein the long sides of the rectangle are oriented in parallel to an axial direction A of the cap 14 which in the mounted state corresponds to the longitudinal direction of the tubular gas generator 12.

[0094] The cross-sectional area of the outflow opening 28 is selected to be so large that the gas flow exiting the tubular gas generator 12 can flow off through the outflow opening 28 without any significantly increased flow resistance.

[0095] The deflector element 16 includes a curved deflection surface 30 whose concave inner side faces the circumferential wall 26 of the cap 14 and the outflow opening 28 so that a tubular cavity 32 is formed between the deflection surface 30 and the outside of the circumferential wall 26.

[0096] The deflection surface 30 is located in a radial direction r outside the outflow opening 28 and, based on the axial direction A and the circumferential direction U, completely covers the same.

[0097] The deflector element 16 is open at both of its axial ends in this example so that a discharge opening 34 that is in direct fluid communication with the cavity 32 is formed at each axial end.

[0098] The deflection surface 30 in this case is oriented so that the tubular cavity 32 extends along the axial direction A.

[0099] A lateral surface 38 extending from a crown line 36 in the direction of the circumferential wall 26 of the cap 14 extends on both sides of a crown line 36 of the deflection surface 30.

[0100] When viewed perpendicularly to the crown line 36, along the axial direction A each of the lateral surfaces 38 merges in a central portion into a securing arm 40 which serves for fixation of the deflector element 16 to the cap 14, see FIG. 3.

[0101] In the axial direction A, in this exemplary arrangement, each securing arm 40 extends in the middle of the deflection surface 30 and has a width of more than about 50% of the length of the deflection surface 30 in the axial direction A.

[0102] The entire deflector element 16 is bent in this case from an integral blank made of a sheet metal having proper resilience, such as a spring steel.

[0103] In one exemplary arrangement, the blank is made from a rectangular portion which later forms the deflection surface 30 and, at each lateral edge, an extension which later forms a securing arm 40, the long sides of the rectangular portion merging into the extensions. In the finished deflector element 16, the short sides form the axial ends of the deflector element 16 and delimit the discharge openings 34.

[0104] The free ends of the extensions are bent outwards and, in the finished deflector element 16, form bent free ends 42 of the securing arms 40 (see FIG. 3).

[0105] The rectangular portion is bent around the crown line 36 extending centrally between the long sides so that the bent deflecting surface 30 is formed. In so doing, the securing arms 40 are moved toward each other, until they are approximately in parallel to each other.

[0106] In a section transversely to the axial direction A level with the securing arms 40, the deflector element 16 thus is approximately horseshoe-shaped (see FIG. 3).

[0107] For mounting the deflector element 16 on the cap 14, the securing arms 40 and/or the lateral surfaces 38 are moved toward each other by applying a predetermined mounting force so that a distance between the bent free ends 42 of opposite securing arms 40 is reduced so far that both securing arms 40 can be slid from outside through the outflow opening 28. The lateral surfaces 38 and/or the securing arms 40 are under a bias acting away from each other.

[0108] The mounting force is then reversed, in particular by being continuously reduced, thus causing the bent free ends 42 of the securing arms 40 to brace apart and move away from each other again due to the bias, until they are urged against an edge 44 of the outflow opening 28, more precisely against two opposite edge portions of the edge 44. In so doing, the bent free ends 42 engage behind the edge 44 of the outflow opening 28 on the inner face of the circumferential wall 26 and lock the deflector element 16.

[0109] As the bent free ends 42 engage behind the edge 44 and possibly the securing arms 40 are adjacent to the edge 44 of the outflow opening 28, a form fit is formed between the deflector element 16 and the cap 14, the form fit holding the deflector element 16 firmly on the cap 14, even when the tubular gas generator 12 is activated and, accordingly, the internal pressure in the interior 24 is increased by the discharging gas flow.

[0110] In the example shown here, the securing arms 40 and, in particular, the bent free ends 42 in the axial direction A have the same dimension as the long side of the outflow opening 28 so that the bent free ends 42 are adjacent, in the axial direction A, to the edge 44 of the outflow opening 28 over the whole length of the respective edge portions.

[0111] An additional fixation of the deflector elements 16 on the cap 14 is not provided here.

[0112] It is also imaginable to design the bent free ends 42 of the securing arms 40 so that the form fit is made automatically by a click-lock, when the securing arms 40 are slid from outside through the outflow opening 28, wherein the edge 44 of the outflow opening 28 initially deflects the securing arms 40 inwards and the latter spring back again, when the bent free ends 42 have passed the edge 44 and then engage behind the inside of the edge 44 (not shown).

[0113] In this exemplary arrangement, in the mounted state the free edges 45 of the lateral surfaces on both sides of the securing arms 40 rest on the circumferential wall 26 of the cap 14 and, in this way, seal the cavity 32.

[0114] For mounting the assembly group 10 on the tubular gas generator 12, at first the cap 14 without the deflector element 16 is slid with the open end 18 over the diffusor at the axial end 22 of the tubular gas generator 12, and the open end 18 of the cap 14 is connected to an outer wall of the tubular gas generator 12 in a firm and particularly gastight manner. This is carried out by roller-burnishing, crimping, flaring or welding, for example.

[0115] After connecting the cap 14 firmly to the tubular gas generator 12, the deflector element 16 is inserted into the outflow opening 28, as described above.

[0116] When the tubular gas generator 12 is activated, the gas exits the gas outlet opening(s) 25 of the tubular gas generator 12 or the diffusor 23 thereof and flows into the interior 24 of the cap 14 and there via the collecting chamber through the outflow opening 28 of the cap 14 into the cavity 32 between the deflection surface 30 of the deflector element 16 and the circumferential wall 26 of the cap 14. The gas is deflected at the deflection surface 30 from the radial direction r to the axial direction A and leaves the assembly group 10 through the two discharge openings 34.

[0117] In the examples shown here, the gas generated by the tubular gas generator 12 flows exclusively through the two discharge openings 34 into the environment of the tubular gas generator 12. However, it is also conceivable to provide additional discharge openings in the deflector element 16 or in the cap 14. It is also possible to form only one single discharge opening in the deflector element 16.

[0118] Each of the discharge openings 34 may be connected, for example, to one single chamber of an airbag, or the entire deflector element 16 may be positioned inside one single inflatable chamber (not shown). Any other suitable application is also imaginable, of course.

[0119] In the just described exemplary arrangement, the discharge openings 34 are directed in the axial direction A.

[0120] FIG. 4 illustrates an exemplary arrangement in which the lateral surfaces 38 on both sides of the securing arms 40 are formed into a circumferentially closed tube, the free edges 45 contacting each other and the cavity 32 being convexly curved as a whole away from the circumferential wall 26. As a result, the two discharge openings 34 are inclined with respect to the axial direction A.

[0121] The configuration and arrangement of the cavity 32, the lateral surfaces 38 and the discharge openings 34 is at the skilled person's discretion and can be easily adapted to different applications.

[0122] Those exemplary arrangements can always be provided with identical securing arms 40 so that, even when different deflector elements 16 are used, always an identically formed cap 14 can be used.

[0123] In the previously described exemplary arrangements, both discharge openings 34 are selected to have an equal cross-sectional area so that each of the gas flows G outflowing there comprises the same amount of gas.

[0124] FIG. 5 illustrates an exemplary arrangement in which the cross-sectional area of the discharge openings 34 is selected to be unequal so that gas flows G.sub.1, G.sub.2 with different amounts of gas result.

[0125] In one exemplary arrangement, the division may be selected at a 60/40 or 70/30 ratio, for example, or at any other ratio.

[0126] The cross-sectional shapes of the discharge openings 34 can be easily obtained by appropriately shaping the deflection surface 30 and, in particular, the lateral surfaces 38.

[0127] FIG. 6 illustrates another variant in which a filter 46 that frees the gas flowing through the outflow opening 28 into the cavity 32 from particles or cools the gas, for example, is inserted in the cavity 32.

[0128] The filter 46 comprises a knitted mesh and/or screens made of a suitable metal in a known way, for example.

[0129] The filter 46 can be inserted into the cavity 32 either before mounting the deflector element 16 to the cap 14 or after mounting the deflector element 16.

[0130] Even in the exemplary arrangements according to FIGS. 5 and 6, the free edges 45 of the lateral surfaces 38 are bent toward each other in the axial direction A on both sides of the securing arms 40 so far that they contact each other so that the discharge openings 34 are formed by the ends of substantially circumferentially closed tubes.

[0131] FIG. 7 shows a further variant in which two outflow openings 28 juxtaposed in the axial direction A are provided in the circumferential wall 26 of the cap 14 which are separated from each other by a central web 48.

[0132] The deflector element 16 in this case includes a total of four securing arms 40, two of which are arranged at the respective opposite lateral surfaces 38 at the axial level of the outflow openings 28. When the deflector element 16 is mounted on the cap 14, the respective adjacent securing arms 40 engage on one side in the two juxtaposed outflow openings 28 so that, in the mounted state, in the axial direction A the central web 48 is located between the securing arms 40.

[0133] It would also be imaginable, of course, to expand this concept to three or more juxtaposed outflow openings 28.

[0134] In FIG. 8, a unit of a tubular gas generator 12 and an assembly group 10 is shown.

[0135] FIG. 8 illustrates how the cap 14 is attached onto and connected to the axial end 22 of the tubular gas generator 12 so that the tubular gas generator 12 and the assembly group 10 form a joint unit.

[0136] The same arrangement is also possible with an assembly group 10 according to FIGS. 1 to 7.

[0137] FIGS. 9 to 11 illustrate the assembly group 10 according to a second exemplary arrangement, the deflector element 16 being inserted in the outflow opening 28 of the cap 14.

[0138] In contrast to the first exemplary arrangement, the deflector element 16 is fixed to the edge 44 of the outflow opening 28 by a bayonet lock.

[0139] For this purpose, the securing arms 40 are selected to be narrower in the axial direction A than in the first exemplary arrangement, and are in particular the same length or narrower than a short side of the outflow opening 28. Moreover, the bent free ends 42 are rounded.

[0140] In general, the deflector element 16 may be more rigid than in the first exemplary arrangement. In particular, a resilient bias as in the first exemplary arrangement is not required here.

[0141] For assembly, the deflector element 16 is initially rotated by 90° vis-à-vis the axial direction A so that the free ends 42 of the two securing arms 40 can be inserted into the outflow opening 28 from outside the cap 14 without major deformation of the deflector element 16, if possible. Then the deflector element 16 is rotated by 90° so that the crown line 36 is oriented in the axial direction A. Accordingly, the bent free ends 42 contact the circumferential wall 26 of the cap 14 on the inside and engage behind the edge 44 of the outflow opening 28.

[0142] In the assembled state, the deflection surface 30 of the deflector element 16 and the cavity 32 below extend, as in the first exemplary arrangement, along the axial direction A radially above the outflow opening 28.

[0143] Generally, all concepts shown here can be easily combined with each other at the skilled person's discretion. For example, a filter 46 can be used with all deflector elements 16. It is also possible to select, for each of the shown deflector elements, a different cross-sectional area of the discharge openings 34 or to vary the direction thereof with respect to the axial direction A.