Airbag, method for manufacturing such an airbag, airbag unit, airbag assembly and vehicle seat unit

Abstract

Airbag (5) comprising a first layer (10), a second layer (20) and an edge connection (30) connecting the two layers (10, 20), such that at least parts of the first layer (10) and the second layer (20) enclose a gas space, wherein the first layer (10) and the second layer (20) each comprise: a first region (11, 21) with a first outer edge (34a), a second region (12, 22) with a second outer edge (34b), and a third region (13, 23) with a third outer edge (34c), a first inner connection region (15, 25) connecting the first region (11, 21) and the second region (12, 22), and a second inner connection region (17, 27) connecting (i) the first region (11, 21) and the third region (13, 23) or (ii) the third region (13, 23) and the second area (12, 22), connects, so that the first area (11) of the first layer (10) and the first area (21) of the second layer (20) form a first part (41) of the airbag (5),enclosing a first chamber of the gas space, the second area (12) of the first layer (10) and the second area (22) of the second layer (20) form a second part (42) of the airbag (5) enclosing a second chamber of the gas space, and the third area (13) of the first layer (10) and the third area (23) of the second layer (20) form a third part (43) of the airbag (5) enclosing a third chamber of the gas space, and the first inner connection area (15) of the first layer (10) and the first inner connection area (25) of the second layer (20) define a first inner connection area (35) of the airbag (5) with at least one first overflow (31b), and the second inner connection area (17) of the first layer (10) and the second inner connection area (27) of the second layer (20) define a second inner connection area (37) of the airbag (5) with at least one second overflow (32b) define, characterized by,that in the case of (i) a section of at least one of the second outer edges (34b) and a section of at least one of the third outer edges (34c) are connected via at least one additional connection (34), and in the case of (ii) a section of at least one of the first outer edges (34a) and a section of at least one of the third outer edges (34c) are connected via at least one additional connection (34), such that when the airbag (5) is inflated, it is folded along the inner connection areas (35, 37) and forms a three-dimensional, self-supporting structure, wherein the first outer edges (34a) define a first plane, the second outer edges (34b) define a second plane, and the third outer edges (34c) define a third plane, each of these planes enclosing an angle between 45° and 90°.

Description

The invention relates to an airbag according to the preamble of claim 1, a method for manufacturing such an airbag according to claim 5, an airbag unit according to claim 6, an airbag arrangement according to claim 8 and a vehicle seat unit according to claim 9. The invention relates in particular to an airbag for attachment to the backrest of a vehicle seat, wherein part of this airbag serves as a side airbag which unfolds laterally to the upper body of an occupant, but is not limited thereto. A conventional side airbag consists of a first layer and a second layer connected by an edge seam in such a way that at least parts of both layers enclose a gas chamber. This gas chamber can be divided into several compartments, so the airbag can be considered as consisting of multiple parts, each enclosing a compartment. Such an airbag can be manufactured very economically because it has a "2D structure," meaning the two layers and the edge seam lie in the same plane throughout the entire production process. This type of airbag can be manufactured using a one-piece woven technique, or at least part of the edge seam must be applied separately, usually in the form of an edge seam. One disadvantage of such side airbags is that even when deployed, they essentially retain their "2D structure". This means they can only protect the side of the person being protected and generally require external support (e.g., the side structure of the vehicle). From the generic patent JP 2010 - 076 640 A, a side airbag with three sections is known, wherein two of these sections, when inflated, are arranged essentially in one plane to the side of the occupant and thus form a "classic" side airbag. A further section, when inflated, extends essentially perpendicular to this and is positioned in front of the occupant's head. The US 2019 / 0 202 394 A1 shows a front gasbag with a central area and two side areas extending laterally from this area. Starting from this state of the art, the present invention aims to provide an airbag that is essentially as easy to manufacture as a conventional side airbag, but whose application possibilities exceed those of a conventional side airbag. This problem is solved by an airbag having the features of claim 1. A preferred method for manufacturing such an airbag is specified in claim 5, an airbag unit with such an airbag is specified in claim 6, an arrangement of such an airbag unit in a vehicle seat is specified in claim 8, and a vehicle seat unit with a vehicle seat and such an airbag arrangement is specified in claim 9. The airbag according to the invention, like a conventional side airbag, comprises a first layer, a second layer, and an edge connection linking the two layers, such that at least parts of the first layer and the second layer enclose a gas chamber. Both layers comprise a first region with a first outer edge, a second region with a second outer edge, and a third region with a third outer edge. The respective regions of the two layers are generally congruent to each other. The first region of the first layer and the first region of the second layer form a first part of the airbag, which encloses a first chamber of the gas chamber; the second region of the first layer and the second region of the second layer form a second part of the airbag, which encloses a second chamber of the gas chamber; and the third region of the first layer and the third region of the second layer form a third part of the airbag, which encloses a third chamber of the gas chamber. Furthermore, each layer comprises a first inner connecting area and a second inner connecting area connecting the first area, such that the airbag also comprises a first inner connecting area and a second inner connecting area of ​​the airbag, wherein the first inner connecting area of ​​the airbag connects the first part of the airbag and the second part of the airbag, and a second inner connecting area of ​​the airbag (i) connects the first area of ​​the airbag and the third area of ​​the airbag or (ii) connects the third area of ​​the airbag and the second area of ​​the airbag. Each internal connecting area has an overflow between the adjacent chambers. According to the invention, in case (i), a section of at least one of the second outer edges and a section of at least one of the third outer edges are connected via at least one additional connection, and in case (ii), a section of at least one of the first outer edges and a section of at least one of the third outer edges are connected via at least one additional connection. This causes the inflated airbag to fold along the inner connection areas, forming a three-dimensional, self-supporting structure such that, in the deployed state, the first outer edges define a first plane, the second outer edges define a second plane, and the third outer edges define a third plane. These planes enclose angles between 45° and 90°. In order to form hinges along which the airbag can be easily bent, it is preferred that each inner connecting area of ​​the airbag has at least one non-inflatable area. In a preferred embodiment, the edge connection is closed; in another preferred embodiment, it has an opening for inserting an inflator. In a preferred method for manufacturing such an airbag, a pre-product of the airbag is first produced. This pre-product comprises the first layer, the second layer arranged on the first layer, and the edge connection. In a further step, the additional connection is applied. Naturally, the airbag according to the invention is generally further processed into an airbag unit that includes an inflator. Since – as will be described later – the first part of the airbag preferably forms a side airbag, this inflator is in most cases located within the first chamber enclosed by the first part. In a preferred airbag arrangement, the airbag unit is attached to a vehicle seat, particularly to the backrest of a vehicle seat. The first part of the airbag then forms a side airbag which, upon deployment, extends laterally along at least one section of the torso of a person seated in the vehicle seat. Furthermore, the second part extends over the shoulder of this person and the third part extends in front of at least one section of the torso, or the third part extends over the shoulder of this person and the second part extends in front of at least one section of the torso. A key advantage is that, due to the self-supporting properties of the airbag according to the invention, the part forming a front airbag (either the second part or the third part) does not require an external support surface.The second main advantage is that the part of the airbag that extends over the shoulder can prevent excessive bending of the neck by holding the head back. The invention will now be described in more detail with reference to preferred embodiments and the figures. The figures show: Fig. 1: a first blank forming a first layer of the airbag of the first embodiment; Fig. 2: a second blank forming a second layer of this airbag; Fig. 3: the second layer from Fig. 2 after it has been placed on the first layer and after an edge seam forming an edge connection has been applied, so that an airbag pre-product is formed; Fig. 4: the pre-product shown in Fig. 3 after turning the pre-product over, with the positions of the additional seam indicated; Fig. 5: a fully manufactured airbag, namely the pre-product shown in Fig. 4 after the additional seam has been applied; Fig. 6: essentially the airbag shown in Fig. 5 in an deployed state; Fig. 7: what is shown in Fig. 6 from another angle; Fig. 8: essentially what is shown in Fig. 9.Fig. 6 shows the deployed airbag in a state in which it is attached to the backrest of a vehicle seat and a person is sitting on this vehicle seat; Fig. 9 shows essentially the same as shown in Fig. 7; Fig. 10 shows a schematic representation of a second embodiment of the invention, essentially in a representation according to Fig. 4; Fig. 11 shows a third embodiment of the invention in a representation according to Fig. 10; Fig. 12 shows a single blank with a first layer and a second layer of a fourth embodiment of the airbag according to the invention; Fig. 13 shows the single blank from Fig. 12 after it has been folded along its fold line and the edge seam has been applied, so that a semi-finished product is formed; Fig. 14 shows the fully assembled airbag of the fourth embodiment, namely the parts shown in Fig. 13, after the additional seam has been applied; and Fig. 15 shows a variant of what is shown in Fig. 13. The construction of the airbag according to the invention will now be described with reference to various embodiments. In most of these embodiments, only the structure of the outer skin of the airbag is shown and described. Therefore, the terms "airbag" and "outer skin of the airbag" are sometimes used synonymously. However, it should be noted that a complete airbag may have more parts, in particular inner retaining straps, outer retaining straps, reinforcement layers, internal gas guide elements, and the like. As an example, an inner retaining strap is shown with reference to the fourth embodiment. Figures 1 and 2 show a first layer 10 and a second layer 20 of the airbag (the outer skin of the airbag) in a schematic representation that shows all the details necessary for understanding the invention. In this first embodiment, both layers 10 and 20 have the form of separate blanks, but, as will be seen particularly with regard to a fourth embodiment, they can also be sections of a single blank designed to be folded around a fold line. The two layers 10, 20 of the first embodiment of the airbag are essentially identical with one exception: The first layer 10 has holes 18 for inflator bolts and an opening 19 for inserting an inflator. Both layers 10, 20 comprise a first region 11, 21, a second region 12, 22, and a third region 13, 23. Naturally, each region has an outer edge, which is designated as the first outer edge, second outer edge, and third outer edge. The first regions 11, 21 and the second regions 12, 22 are connected via the first inner connecting regions 15, 25, and the first regions 11, 21 and the third regions 13, 23 are connected via the second inner connecting regions 17, 27. As can be seen directly from the drawings, the inner connection areas each have indentations 15a, 17a, 25a and 27a at their two ends. Providing such indentations is generally preferred, although not strictly necessary.According to the definitions chosen in this application, the indentations constitute non-inflatable areas. In one production step, the two layers 10, 20 are placed on top of each other and an edge seam 30 is applied (Figs. 3 and 4). In this embodiment, this edge seam 30 alone forms the edge connection and is closed, so that the two layers 10, 20 and the edge connection 30 completely enclose the gas chamber of the airbag. Of course, other types of edge connections such as bonding, welding, or the like can also be used, but a seam is the most common. As will be seen later with regard to the fourth embodiment, part of the edge connection can also be formed in the form of a fold. Furthermore, the edge connection could be formed in the form of a one-piece woven connection (OPW). Additionally, a first hinge connection seam 31 connects the first inner connection area 15 of the first layer 10 to the first inner connection area 25 of the second layer 20, and a second hinge connection seam 32 connects the second inner connection area 17 of the first layer 10 and the second inner connection area 27 of the second layer 20, so that inner non-inflatable areas 31a and 32a are formed in the inner connection areas of the airbag. The first inner non-inflatable area 31a lies in line with the incisions 15a, 25a, and the second inner non-inflatable area 32a lies in line with the incisions 17a, 27a, thus forming hinges. The airbag (called "pre-product" 3 at this stage) is now almost finished and can be seen to comprise a first part 41 - consisting of the first part 11 of the first layer 10 and the first part 21 of the second layer 20 - which includes a first chamber, a second part 42 - consisting of the second part 12 of the first layer 10 and the second part 22 of the second layer 20 - which includes a second chamber, and a third part 43 - consisting of the third part 13 of the first layer 10 and the third part 23 of the second layer 20 - which includes a third chamber.The first part 41 is connected to the second part via the first inner connection 35 of the airbag, which includes the first inner connection 15 of the first layer and the first inner connection 25 of the second layer, and to the third part 43 via the second inner connection 37 of the airbag, which includes the second inner connection 17 of the first layer 10 and the second inner connection 27 of the second layer 20. The first chamber is connected to the second chamber via two overflows 31b adjacent to the first non-inflatable area 31a, and the first chamber is also connected to the third chamber via two overflows 32b adjacent to the second non-inflatable area 32a. The overflows 31b are located (naturally) in the first inner connection area 35, and the overflows 32b are located (naturally) in the second inner connection area 37. In a final manufacturing step, the second part 42 and the third part 43 of the airbag are joined together by means of an additional connection in the form of an additional seam 34. The positions of this additional seam 34 along a section of the second outer edge 34c and a section of the third outer edge 34c are indicated in Fig. 4. Fig. 5 shows the result in a state where the airbag is not inflated but is folded along the hinges defined by the first inner connection area 35 and the second inner connection area 37, creating a three-dimensional structure in which each of the parts 41, 42, and 43 defines a plane. In the illustrated embodiment, the angle between the plane of the first part 41 and the plane of the third part 43 is approximately 90°, the angle between the plane of the second part 42 and the plane of the third part 43 is also approximately 90°, and the angle between the plane of the first part 41 and the plane of the third part 43 is approximately 60°. Since the airbag, and in particular its outer skin, is of course made of a conventional and therefore flexible airbag material, the airbag can be folded flat (so that all parts lie essentially in one plane), but this is not possible along the hinges of the connection areas. Consequently, when filled with gas, the airbag 5 “automatically” unfolds into a three-dimensional structure, since in this state the airbag can only bend along its predefined hinges. The inflated state is illustrated, for example, in Figures 6 and 7. The angles between the planes of the three parts are essentially as described above, but since most areas of the outer skin of the airbag cushion are convex in the inflated state, the planes are defined solely by the outer edges, which remain essentially flat. Figure 8 shows the inflated airbag shown in Figure 6 in a state in which it is attached to the backrest 64 of a vehicle seat 60. An inflator 50 is located inside the first part 41 and is attached to the frame of the backrest, for example in a conventional manner by means of inflator bolts extending through the holes 18, so that the inflator also attaches the airbag 5 to the backrest 64 of the vehicle seat 60. An indirect attachment of the inflator to the backrest, for example by means of clamps, is of course also possible. The first part 41 extends essentially in the XZ plane like a conventional side airbag along at least part of the torso of a person P seated in the vehicle seat 60. The second part 42 extends from the upper end of the first part 41 over the occupant's shoulder, and the third part 43 forms a front airbag located in front of at least part of the occupant P's torso. Due to its three-dimensional structure, the airbag 5 is largely "self-supporting," and in particular the front part (here the third part 43) does not require a supporting surface such as a dashboard or steering wheel. Although only one airbag unit is shown in Fig. 8, it is possible to provide such an airbag unit on both sides of the seat, so that the first part of a first airbag unfolds to the left of the person and the first part of a second airbag unfolds to the right of the person. Fig. 10 shows a second embodiment in a representation essentially as in Fig. 3, but without the edge connection seam 30. As in the first embodiment, the first inner joining area 35 extends between the first part 41 and the second part 42, but the second inner joining area 37 extends between the second part 42 and the third part 43. Furthermore, the additional seam (or other additional connection) joins sections of the first outer edges 34a and the third outer edges 34c. The positions of this additional seam are indicated by reference numerals 34a and 34c. As in the first embodiment, the first part 41 forms a side airbag in a typical application, the second part 42 a shoulder-extending part, and the third part 43 a front airbag. Also as in the first embodiment, the inflator is located in the first part 41. The main difference from the first embodiment is that the airbag has a serial deployment behavior, with the third part 43 deploying last (in the first embodiment, the second part 42 and the third part 43 deploy essentially simultaneously). Figure 11 shows a third embodiment, which also has a serial configuration. According to the definition chosen in this application, the first part 41 forms the side airbag part (as in all embodiments), the second part 42 the front part, and the third part 43 the part that extends over the shoulder. Thus, the construction is the same as in the second embodiment: the first inner connection 35 extends between the first part 41 and the second part 42, and the second inner connection 37 extends between the second part 42 and the third part 43; the additional connection (additional seam) joins a section of the first outer edge 34a and a section of the third outer edge 34c. In this embodiment, the front airbag part inflates before the shoulder airbag part. It can therefore be seen that despite the fact that the fully deployed airbag has the same shape in all three first embodiments, the deployment behavior can be chosen. Figures 12, 13 to 14 show a fourth embodiment in a somewhat more detailed view. The main difference is that the outer skin of the airbag is made from a single blank 7, i.e., the first layer 10 is a first section of this single blank and the second layer 20 is the second section (the left section in Figure 12). In contrast to the first embodiment, the two sections of the single blank are not 100% congruent, since the second section has an additional attachment area 29 that lies outside the edge seam 30 (see Figure 13). It should also be noted that the positions of the additional seam are in the form of protruding areas, which facilitates the sewing process. Fig. 13 shows the situation after folding the single blank 7 along the fold line FL and applying the edge seam 30. The complete edge seam consists of this edge seam 30 and the fold F between the two sections. The edge seam is not completely closed, as an opening 19 remains for inserting the inflator, which in this embodiment can be closed by a closure section 8 of the single blank 7; this is shown in Fig. 13. An inner retaining strap 70 is also shown in Fig. 13. Fig. 14 shows the fully assembled airbag, including the additional seam 34. It can be seen that the folding of the airbag in the flat folded state does not occur along the hinges defined by the inner connection areas. With the geometry of this embodiment, the pre-product 3 must be folded along two lines of fold LF; however, with other geometries, only one such line of fold LF might suffice. The structure of this embodiment could, of course, also be applied to the geometries of the second and third embodiments. Fig. 15 shows a variant of the fourth embodiment. Here, only one layer has protrusions for the additional seam.

Claims

Airbag (5) comprising a first layer (10), a second layer (20) and an edge connection (30) connecting the two layers (10, 20), such that at least parts of the first layer (10) and the second layer (20) enclose a gas space, wherein the first layer (10) and the second layer (20) each comprise: a first region (11, 21) with a first outer edge (34a), a second region (12, 22) with a second outer edge (34b), and a third region (13, 23) with a third outer edge (34c), a first inner connection region (15, 25) connecting the first region (11, 21) and the second region (12, 22), and a second inner connection region (17, 27) connecting (i) the first region (11, 21) and the third region (13, 23) or (ii) the third region (13, 23) and the second area (12, 22), connects, so that the first area (11) of the first layer (10) and the first area (21) of the second layer (20) form a first part (41) of the airbag (5),enclosing a first chamber of the gas space, the second area (12) of the first layer (10) and the second area (22) of the second layer (20) form a second part (42) of the airbag (5) enclosing a second chamber of the gas space, and the third area (13) of the first layer (10) and the third area (23) of the second layer (20) form a third part (43) of the airbag (5) enclosing a third chamber of the gas space, and the first inner connection area (15) of the first layer (10) and the first inner connection area (25) of the second layer (20) define a first inner connection area (35) of the airbag (5) with at least one first overflow (31b), and the second inner connection area (17) of the first layer (10) and the second inner connection area (27) of the second layer (20) define a second inner connection area (37) of the airbag (5) with at least one second overflow (32b) define, characterized by,that in the case of (i) a section of at least one of the second outer edges (34b) and a section of at least one of the third outer edges (34c) are connected via at least one additional connection (34), and in the case of (ii) a section of at least one of the first outer edges (34a) and a section of at least one of the third outer edges (34c) are connected via at least one additional connection (34), such that when the airbag (5) is inflated, it is folded along the inner connection areas (35, 37) and forms a three-dimensional, self-supporting structure, wherein the first outer edges (34a) define a first plane, the second outer edges (34b) define a second plane, and the third outer edges (34c) define a third plane, each of these planes enclosing an angle between 45° and 90°. Airbag (5) according to claim 1, characterized in that the two layers (10, 20) are congruent. Airbag (5) according to one of the preceding claims, characterized in that each inner connecting area (35, 37) has at least one non-inflatable area, preferably an inner non-inflatable area (31a, 32a), to form a hinge. Airbag (5) according to one of the preceding claims, characterized in that the edge connection (30) is closed or is closed except for an opening (19) for the insertion of an inflator (50). Method for manufacturing an airbag (5) according to one of the preceding claims, comprising the following successive steps: providing a pre-product (3) comprising the first layer (10), the second layer (20) arranged on the first layer (10) and the edge connection (30), and applying the additional connection. Airbag unit comprising an airbag (5) according to one of claims 1 to 4 and an inflator (50) for inflating the airbag (5). Airbag unit according to claim 6, characterized in that the inflator (50) is arranged within the first chamber. Airbag arrangement in a vehicle seat (60) with an airbag unit according to claim 6 or claim 7, wherein when the airbag (5) is inflated by the inflator (50), the first chamber extends laterally to at least one section of the torso of a person seated in the vehicle seat, and (iii) the second chamber extends over the shoulder of that person and the third chamber extends in front of at least one section of the torso of that person, or (iv) the third chamber extends over the shoulder of that person and the second chamber extends in front of at least one part of the torso of that person. Vehicle seat unit with the airbag arrangement according to claim 8 and a vehicle seat (60) to which the airbag arrangement is attached.

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