Unknown

Abstract

The invention relates to an airbag, which is configured to be set from an uninflated state to an inflated state to protect an occupant of a vehicle. According to the invention, it is provided that the airbag has at least two fabric layers which are connected to one another in such a way that a central inflow region forming a first airbag chamber and at least two wing regions forming respective second airbag chambers and extending radially from the inflow region are formed, so that during the inflation operation of the airbag a gas can first flow into the central inflow region and then from the central inflow region into the respective wing regions, distal end portions of the at least two wing regions being connected to one another via a flat tensioning element, so that the distal end portions move axially away from the central inflow region during the inflation operation of the airbag and, in the inflated state of the airbag, radially tension the flat tensioning element at an axial distance from the central inflow region.

Claims

1. An airbag, preferably a one-piece woven (OPW) airbag, which is configured to be set from an uninflated state to an inflated state by an inflation operation to protect an occupant of a vehicle, wherein the airbag has at least two fabric layers which are connected to one another in such a way that a central inflow region forming a first airbag chamber and at least two wing regions forming respective second airbag chambers extending away from or radially from the inflow region are formed, so that during the inflation operation of the airbag, a gas can first flow into the central inflow region and then from the central inflow region into the respective wing regions, wherein distal end portions of the at least two wing regions are connected to one another via a flat tensioning element, so that during the inflation operation of the airbag the distal end portions move in the depth direction of the airbag away from the inflow region or move axially away from the central inflow region and in the inflated state of the airbag stretch or radially tension the flat tensioning element in the depth direction away from the inflow region or axially spaced from the central inflow region.

2. The airbag according to claim 1, wherein the fabric layers in the wing regions are linked to one another in such a way that, during the inflation operation of the airbag, their distal end portions stretch or radially tension the flat tensioning element at a distance from the central inflow region in a position of the at least two wing regions which is determined by a stretching force of the flat tensioning element.

3. The airbag according to claim 1, wherein the fabric layers in the wing regions are linked together in such a way that, during the inflation operation of the airbag, the at least two wing regions curve outwards in a radial direction at least in portions and/or in the inflated state of the airbag the at least two wing regions extend axially from the central inflow region and are bent radially outwards at least in portions.

4. The airbag according to claim 1, wherein the airbag has three fabric layers at least in the wing regions, namely a first fabric layer, a second fabric layer and a third fabric layer, wherein the second fabric layer is arranged between the first fabric layer and the third fabric layer, wherein the three fabric layers are interwoven with one another in such a way that stiffening chambers are formed between the first fabric layer and the second fabric layer and the third fabric layer and the second fabric layer, which stiffening chambers (OK; UK) extend in the circumferential direction and are offset radially with respect to one another and cause the wing regions to be curved outwards at least in portions during the inflation operation thereof.

5. The airbag according to claim 1, wherein the airbag is configured as an OPW airbag with warp threads and weft threads woven into the woven fabric layers in the central inflow region and the respective wing regions, wherein the warp threads and weft threads are woven together in such a way that the airbag forms the central inflow region in two layers and the respective wing regions in three layers, wherein in a first partial region (ETB) between a respective wing region and a second partial region which extends towards and finally forms the inflow region, the warp and weft threads of the second fabric layer emerge from the second fabric layer and float completely between the first fabric layer and the third fabric layer and are incorporated in the first fabric layer or in the third fabric layer in the second partial region.

6. Airbag according to claim 1, wherein adjacent wing regions are connected to each other in circumferential direction at least in portions, preferably sewn together via seam portions.

7. The airbag according to claim 1, wherein the airbag, in the inflated state, is configured to be circular when viewed in the axial direction, and/or the wing regions, in the inflated state of the airbag, are configured to be in the shape of a segment of a circle when viewed in the axial direction.

8. The airbag according to claim 1, wherein the at least two fabric form a circular or star-shaped contour of the airbag when lying on top of each other.

9. The airbag according to claim 1, wherein the airbag in the inflated state has the shape of a paraboloid, in particular a rotational paraboloid or elliptical paraboloid or a bowl.

10. The airbag according to claim 1, wherein the airbag in the inflated state is configured such that the inflow region, the wing regions and the flat tensioning element surround, at least in portions, a space outside the inflated airbag.

11. The airbag according to one of the preceding claims claim 1, wherein the airbag forms a flat or concave shape in the region of the distal end portions and the flat tensioning element.

Description

[0035] A preferred embodiment of the invention is explained below by way of example with reference to the figures.

[0036] These show:

[0037] FIG. 1 is a schematic diagram of an airbag according to the invention in the deployed state in a view from above;

[0038] FIG. 2a is schematic diagram of the airbag according to the invention of FIG. 1 in the inflated state in a view from above;

[0039] FIG. 2b is a schematic cross-sectional diagram of the airbag according to the invention of FIG. 1 in the inflated state;

[0040] FIG. 3 is a schematic diagram of a part of the airbag according to the invention of FIG. 1 in the deployed state in a view from above;

[0041] FIG. 4a is schematic diagram of a part of the airbag according to the invention of FIG. 1 in the deployed state in a view from above with indicated sectional lines A-A and B-B;

[0042] FIG. 4b is a schematic diagram of the part of the airbag according to the invention of FIG. 4a in the deployed state in a sectional view according to sectional line A-A;

[0043] FIG. 4c is schematic diagram of the part of the airbag according to the invention of FIG. 4a in the deployed state in a sectional view according to sectional line B-B;

[0044] FIG. 5a-5b are schematic diagrams of the airbag of FIG. 1 according to the invention in perspective views from the side and from above.

[0045] In the embodiments shown in FIGS. 1 to 5, the airbag or gas bag 10 according to the invention is manufactured as an OPW airbag, i.e. it is a so-called one piece woven airbag 10, i.e. an airbag 10 woven in one piece.

[0046] In the specific case of application, the airbag 10 in this embodiment example is designed as a steering wheel airbag and is accordingly provided on a steering wheel not shown in detail in a conventional manner not described in detail here.

[0047] The airbag 10 according to the invention is configured to be moved from an uninflated state, such as a folded or collapsed state, to an inflated or deployed state, in which the airbag can achieve its protective effect for the occupant, for the protection of an occupant of a vehicle such as a motor vehicle or commercial vehicle, in a conventional manner by means of an inflation operation, for example by means of a conventional gas generator which is not further specified here. That is, the airbag 10 is deployed from the uninflated state to the inflated state in a conventional manner in response to activation of an inflation device such as a gas generator, which is activated, for example, when a vehicle collision or the like is detected.

[0048] The airbag 10 according to the invention is shown in more detail in FIGS. 1 and 2. FIG. 1 shows a schematic representation of the airbag 10 according to the invention in the deployed state in a view from above, in which a tensioning element 17 described in more detail below still rests loosely on the parts forming the airbag chambers of the airbag 10, i.e. is not yet attached thereto. On the other hand, FIG. 2a shows a schematic representation of the airbag 10 according to the invention in the inflated state with tensioning element 17 attached in a view from above and FIG. 2b shows a schematic representation of the airbag 10 according to the invention with tensioning element 17 attached in the inflated state in a cross-sectional view.

[0049] As can be seen in principle in FIGS. 1 and 2, the airbag 10 has a plurality of fabric layers 11, 12, 13, which are described in more detail below and are connected to one another in such a way that a central inflow region 14 forming a first airbag chamber and, in this case, four wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4 (all designated 15 for short) extending away from the inflow region 14, in this case extending radially away and forming respective second airbag chambers, are formed.

[0050] These areas 14 and 15 thus form the part of the airbag forming the airbag chambers. Accordingly, during the inflation operation of the airbag 10, a gas can first flow into the central inflow region 14 and then from the central inflow region 14 into the respective wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4. For example, a section of the inflow region 14 is designed as a generator mouth to accommodate a gas generator for filling the airbag 10 or as a connection region for connecting a generator. The generator is mounted and connected in the conventional way and is therefore not described in detail.

[0051] The respective wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4 in turn have respective distal end portions 16.sub.1, 16.sub.2, 16.sub.3, 16.sub.4, which are connected to one another via a flat tensioning element 17. In particular, a respective distal end portion 16.sub.1, 16.sub.2, 16.sub.3, 16.sub.4 may be an outermost edge region of the respective wing region 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4. Alternatively, however, a respective distal end portion 16.sub.1, 16.sub.2, 16.sub.3, 16.sub.4 may also be a portion offset further inwards or further radially inwards by a predetermined distance from the outermost edge region of the respective wing region 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4.

[0052] The distal end portions 16.sub.1, 16.sub.2, 16.sub.3, 16.sub.4 are in any case each connected directly to the tensioning element 17 and indirectly to one another via the tensioning element 17.

[0053] This causes the distal end portions 16.sub.1, 16.sub.2, 16.sub.3, 16.sub.4 to move in the depth direction of the airbag or axially away from the central inflow region 14 during the inflation operation of the airbag 10 and, in the inflated state of the airbag 10, to stretch the flat tensioning element 17 at an axial distance from the central inflow region 14, in this case radially, as can be seen in particular in FIG. 2b).

[0054] In particular, the fabric layers 11, 12, 13 in the wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4, which are described in more detail below, are linked to one another in such a way that the distal end portions 16.sub.1, 16.sub.2, 16.sub.3, 16.sub.4 of the wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4, during the inflation operation of the airbag 10, stretch or radially tension the tensioning element 17, for example in the form of a flat fabric piece or a nonwoven fabric blank, at a distance or away from the central inflow region 14 in a position of the four wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4which is determined by an expansion capacity and/or a stretching force of the flat tensioning element 17 and the rigid and stable structure of the respective wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4, as shown by way of example in FIG. 2b).

[0055] As can also be seen in FIG. 2b) in particular, the fabric layers 11, 12, 13 are linked together in the wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4 in such a way that the four wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4 curve outwards in a radial direction at least in portions during the inflation operation of the airbag 10 and extend axially away from the central inflow region 14 when the airbag 10 is in the inflated state. Together with the inflow region 14, they thus form an outer shell and inner shell of the part of the airbag chamber 10 forming the airbag chambers.

[0056] Furthermore, adjacent wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4 are connected to each other in portions in the circumferential direction, namely via seam portions 18, which are sewn together, for example. As a result, respective gaps are formed between the wing regions in the radial direction between the seam portions 18 and the inflow region 14, in which the adjacent wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4 are not connected to one another.

[0057] As a result, the airbag 10 takes on the shape of a paraboloid, in particular a rotational paraboloid or elliptical paraboloid or a bowl, in the inflated state. In the inflated state, the airbag 10 is shaped such that the inflow region 14, the wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4 and the flat tensioning element 17 surround, at least in portions, a space or cavity outside the inflated airbag 10, this cavity thus not representing an inflation volume of the airbag, i.e. not being a space that can be filled with gas or air during the inflation operation. Rather, the cavity is at atmospheric pressure or at least at a different pressure from the filled airbag 10.

[0058] Thus, the airbag 10 is circular when viewed in the axial direction when in the inflated state, the wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4 being segmental circular when viewed in the axial direction when the airbag 10 is in the inflated state.

[0059] FIG. 3 shows a schematic representation of a part of the airbag 10 according to the invention of FIG. 1, namely only the part of the airbag 10 forming the airbag chamber and inflow region, in the deployed state in a view from above, i.e. a representation of the airbag 10 as such without the tensioning element 17 and without interconnected seam portions 18.

[0060] As can be seen, the fabric layers 11, 12, 13 which are explained in more detail below, form a circular or star-shaped contour of the airbag when they are on top of each other or when the airbag 10 is laid out. A surrounding woven seam WN is formed in the edge area of the part of the airbag 10 thus laid out or spread out to form airbag chambers, in which the two or three fabric layers 11, 12, 13 converge or are woven together to form a seam. The specific structure of the airbag 10 or the part of the airbag 10 forming the airbag chambers is now described below in conjunction with FIGS. 4a) to 4c).

[0061] FIG. 4a shows, similar to FIG. 3, a schematic representation of a part of the airbag 10 according to the invention of FIG. 1 in the deployed state in a view from above, but with sectional lines A-A and B-B indicated. FIG. 4b shows a schematic representation of the part of the airbag 10 according to the invention of FIG. 4a in the deployed state in a sectional view according to sectional line A-A and FIG. 4c shows a schematic representation of the part of the airbag 10 according to the invention of FIG. 4a in the deployed state in a sectional view according to sectional line B-B.

[0062] As can be seen in particular from FIG. 4b), the airbag 10 essentially has a two-layered region, which is formed by the second partial region ZTB, which is explained in more detail below and has the central inflow region 14. Accordingly, the second partial region with the central inflow region 14 is formed by a first, in the illustrated case lower fabric layer 11 and a third, in the illustrated case upper fabric layer 13.

[0063] The wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4 extending radially from the second partial region ZTB with the central inflow region 14 (shown in section A-A are 15.sub.1, 15.sub.2) each have three fabric layers 11, 12, 13, namely the lower fabric layer 11, the upper fabric layer 13 and a second, in the case shown middle fabric layer 12 arranged between them. In particular, the airbag 10 is designed as said OPW airbag with warp threads running in the warp direction K in FIG. 4b) and weft threads running in the weft direction S in FIG. 4b), which are woven in two woven fabric layers 11 and 13 in the second partial region ZTB with the central inflow region 14 and in three woven fabric layers 11, 12 and 13 in the respective wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4.

[0064] As can be seen in particular in FIG. 4b), the warp threads and weft threads are woven together in such a way that the airbag 10, as already mentioned, forms the second partial region ZTB with the central inflow region 14 in two layers and the respective wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4 in three layers.

[0065] A change from the respective three-layer wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4 to the two-layer second partial region ZTB with the central inflow region 14 takes place in a first partial region ETB adjacent to the respective wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4, which thus forms a transition region.

[0066] In the first partial region ETB, the warp and weft threads of the middle fabric layer 12 emerge from it and float completely between the lower fabric layer 11 and the upper fabric layer 13 (shown as floating warp and weft threads FF in FIG. 4b).

[0067] Adjacent to the first partial region ETB is the aforementioned second partial region ZTB, which finally ends in the central inflow region 14.

[0068] At the transition from the first partial region ETB to the second, two-ply configured partial region ZTB, the warp and weft threads of the middle fabric layer 12, which were previously floating in the first partial region ETB, enter the upper fabric layer 13 or the lower fabric layer 11.

[0069] The second partial region ZTB is therefore configured in two layers, i.e. it consists only of the upper fabric layer 11 and the lower fabric layer 13 and finally forms the central inflow region 14, in which the generator mouth or the connection region in which the generator is accommodated or connected is also located. The lower fabric layer 11 and the upper fabric layer 13 in the second partial region thus have corresponding proportions of the warp and weft threads of the middle fabric layer 12 of the first partial region.

[0070] As can be seen in more detail from FIG. 4c), in which the section B-B through the wing region 151 is shown, the three fabric layers 11, 12, 13 are interwoven in the respective wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4 in such a way that stiffening chambers VK extending in the circumferential direction and radially offset relative to one another are formed between the lower fabric layer 11 and the middle fabric layer 12 and the upper fabric layer 13 and the middle fabric layer 12, i.e. in the case shown in FIG. 4c, lower and upper stiffening chambers UK and OK are formed, which cause the wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4 to be curved outwards, at least in portions, during their inflation operation. Due to this arrangement of the stiffening chambers VK, namely the provision of smaller distances between some upper or outer stiffening chambers OK and larger distances between the lower or inner stiffening chambers UK, the curvature of the airbag 10 is achieved outwards, in the case shown in FIG. 4c downwards.

[0071] FIGS. 5a and b show schematic representations of the airbag 10 of FIG. 1 according to the invention in perspective views from the side and from above. In this respect, FIG. 5a) shows the airbag 10 in the inflated state without the tensioning element 17, whereas FIG. 5b) shows the airbag 10 in the inflated state with the tensioning element 17 attached.

[0072] As can be seen in FIG. 5b, the airbag 10 forms a concave shape in the region of the distal end portions 16.sub.1, 16.sub.2, 16.sub.3, 16.sub.4 and the flat tensioning element 17 in this case, which is achieved by the fact that the tensioning element 17 is attached to the distal end portions 16.sub.1, 16.sub.2, 16.sub.3, 16.sub.4 somewhat offset in the radial direction towards the inflow region 14 at the distal end portions 16.sub.1, 16.sub.2, 16.sub.3, 16.sub.4 and is not attached to the outermost edge of the wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4.

[0073] The inflation operation of the OPW airbag according to the invention described above is thus as follows:

[0074] When the inflation device in the form of the gas generator is activated, gas flows into the two-layer second partial region with the central inflow region 14, then enters the first partial region ETB, which forms the transition region, and from there into the respective lower and upper stiffening chambers UK, OK of the respective wing regions 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4. The airbag 10 unfolds, stretching the tensioning element 17 and finally assuming a bowl shape, as can be seen in FIGS. 2b and 5.

[0075] In the case shown in FIG. 5, the tensioning element 17, unlike that of FIG. 2, has a square shape and not a circular shape, resulting in a different shape of the airbag 10 in the inflated state.

[0076] The features of the invention which are disclosed in the above description, in the drawings and in the claims may be essential for implementing the invention both individually and in any desired combination.

REFERENCE SIGNS

[0077] 10 airbag [0078] 11 first/lower/outer fabric layer [0079] 12 second/middle fabric layer [0080] 13 third/upper/inner fabric layer [0081] 14 central inflow region (generator mouth or connection region) [0082] 15.sub.1, first radially extending wing region [0083] 15.sub.2, second radially extending wing region [0084] 15.sub.3, third radially extending wing region [0085] 15.sub.4 fourth radially extending wing region [0086] 16.sub.1, first distal end portion of the first wing region [0087] 16.sub.2, second distal end portion of the second wing region [0088] 16.sub.3, third distal end portion of the third wing region [0089] 16.sub.4 fourth distal end portion of the fourth wing region [0090] 17 flat tensioning element, in particular flat fabric piece [0091] 18 seam portion [0092] ETB first partial region [0093] ZTB second partial region [0094] FF floating warp and weft threads [0095] VK stiffening chambers [0096] OK upper stiffening chambers [0097] UK lower stiffening chambers [0098] S weft direction [0099] K warp direction [0100] WN woven seam