Vehicle occupant protection system with airbag

Abstract

The invention relates to a vehicle occupant protection system having an airbag (112) for protecting the legs of a vehicle occupant, which airbag (112) is arranged in a folded manner on a vehicle floor (30) in front of an associated seat prior to activation of the vehicle occupant protection system and is deployed from the floor (30) in front of the seat in a constrained state. The balloon (112) comprises a plurality of tubular inflatable chambers (18) in flow connection, which are connected to one another three-dimensionally in the inflated state, a plurality of the chambers (18) forming a support rod (124) of the balloon (112), and at least one of the chambers (18) forming a restraining chamber (22) in the upper region of the balloon (112), the restraint chamber is disposed directly in front of the tibial, knee or pelvic region of the vehicle occupant. At least the section of the bladder (112) containing the inflatable chamber (18) is woven integrally.

Description

Technical Field

[0001] The invention relates to a vehicle occupant protection system with an air bag. Background Art

[0002] In the previous designs of vehicle interiors, vehicle occupants have only very limited freedom of movement for their legs. Although this is disadvantageous for the comfort of the vehicle occupants, it has the advantage that in the restrained state the legs of the vehicle occupants are restrained essentially by components fixed to the vehicle, such as the front wall of the vehicle compartment, the dashboard or a seat arranged in front of the legs. In addition, special knee airbags are known for improving leg protection, which are deployed from a corresponding structure fixed to the vehicle in the direction of the legs of the vehicle occupant.

[0003] In new design concepts (particularly in connection with automated driving) the aim is to enable vehicle occupants to choose their sitting or standing position in the vehicle cabin more freely. At the same time, there may also be situations in which sufficient leg freedom is provided. Summary of the invention

[0004] The object of the present invention is to improve the protection of the legs of a vehicle occupant and to improve the kinematics of the vehicle occupant, in particular of the legs, in such a sitting position.

[0005] The object is achieved by a vehicle occupant protection system with an airbag for protecting the legs of a vehicle occupant, the airbag being arranged in a folded manner on the vehicle floor in front of the associated vehicle seat before the vehicle occupant protection system is activated, and the airbag is deployed from the floor in front of the vehicle seat in the restrained state. The airbag comprises a plurality of tubular inflatable chambers in fluid connection, which are three-dimensionally connected to each other in the inflated state, wherein a plurality of the chambers form support rods for the airbag and at least one of the chambers forms a restraint chamber in the upper region of the airbag. The restraint chamber is arranged directly in front of the shin region, knee region or pelvic region of the vehicle occupant in the fully inflated state of the airbag. At least the airbag section containing the inflatable chamber is woven into one piece.

[0006] When the relevant vehicle seat provides sufficient leg freedom forward, the airbag in the restrained state mainly provides protection against the vehicle occupant's legs swinging upward on the vehicle seat.

[0007] Also can consider air bag to be arranged in the zone of the structure fixed with vehicle.In this case, air bag plays the effect of knee air bag in restraint state, and protects vehicle occupant's leg, avoids contact with the structure fixed with vehicle.

[0008] The support rods ensure that the airbag has its desired three-dimensional shape and stabilize it in this shape. In this way, an airbag can be realized which encloses a large volume overall, but requires relatively little filling gas due to the inflatable tubular chamber. In this way, the airbag does not require any further support surfaces on components fixed to the vehicle, apart from the vehicle floor. By varying the arrangement of the support rods, the airbag can be easily designed so that the restraint chamber is in the desired position for the respective vehicle and the respectively considered restraint situation.

[0009] The internal pressure of the support rod can be selected to be higher than in conventional airbags in order to increase the shape-stabilizing effect. Due to the low overall volume, no more or only slightly more filling gas is required than in conventional knee airbags. The airbag itself has sufficient flexibility to receive, in particular, the legs of a vehicle occupant, since the tubular chamber yields substantially perpendicularly to its longitudinal extension when loaded.

[0010] The support rods are preferably connected to form a three-dimensional frame. The restraining chamber is in particular the upper crossbar forming the frame, for example the crossbar arranged uppermost with reference to the vertical direction (in a fully inflated airbag).

[0011] The surfaces between the individual tubular chambers are preferably open, so that the airbag consists only of a plurality of inflatable tubular chambers.

[0012] The airbag may have only one or more dedicated restraint chambers, which for example have a larger diameter transversely to their longitudinal extension and thus usually have a larger volume than the support rod in order to receive the vehicle occupant's legs more evenly or better support them. The diameter here refers in each case to the diameter transversely to the longitudinal extension of the tubular chamber.

[0013] However, when the vehicle occupant comes into contact with the airbag, each portion of the airbag and each tubular chamber and the support rod certainly play a restraining role.

[0014] By choosing the length and orientation of the support rods, the airbag shape can be easily adapted to the respective desired purpose. In the inventive airbag for protecting the legs of a vehicle occupant, no restraint chamber is arranged above the pelvic region of the vehicle occupant (relative to the dimensions of the 50% dummy or the 95% dummy).

[0015] Optionally, one of the floor-proximate support bars may be configured to catch the heel of a vehicle occupant in the region of the vehicle floor, thereby preventing forward movement thereof.

[0016] The support rod is constructed and arranged, for example, in such a way that when the airbag is inflated, there is space for the legs of the vehicle occupant in the area below the restraint chamber, so that the airbag has a free space centrally below the restraint chamber, in which the legs can be swung upward and received by the underside of the restraint chamber, so that in particular the legs can be prevented from swinging upward.

[0017] The airbag in the fully inflated state may have the shape of a wedge-shaped frame having a nearly horizontal support rod near the floor and a nearly vertical support rod on each side of the airbag. The nearly horizontal support rod and the vertical support rod are each connected to each other in an inflatable corner region. The restraint chamber extends between the upper ends of the vertical support rods.

[0018] Additionally, crossbars extending along the floor may connect support bars close to the floor.

[0019] Furthermore, further support rods may be provided which further stabilize the shape. In general, the airbag is intended to form an inherently dimensionally stable frame.

[0020] In order to fix the airbag on the floor, suitable fixing parts, such as a fabric pull tab woven into one with the rest of the airbag, are arranged at least on the lower ends of the vertical support rods and / or the inclined support rods. These fixing parts are connected to a fixing structure fixed to the vehicle on the vehicle floor, such as by hooks or bolts.

[0021] Preferably all tubular chambers, ie support rods and constraining chambers, are in fluid connection.

[0022] According to the invention, the airbag is at least partially or completely produced using an integrated weaving process (one piece weaving, OPW). This allows simple production of the airbag and at the same time reduces scraps, despite the complex geometry of the airbag.

[0023] In this weaving process, all layers of the airbag are woven simultaneously, wherein two separate woven outer layers are formed in the inflatable chambers, which are spaced apart from one another in the inflated state and which form the airbag envelope in these areas and seal the airbag off from the surroundings. All warp and weft threads of the two outer layers meet at the edges of the respective inflatable chambers and are combined to form a single fabric layer.

[0024] Furthermore, one or more further intermediate layers can be formed between the two outer layers by a weaving process. Such intermediate layers consist of the warp and / or weft threads of the two outer layers and, as an alternative or alternative, can also consist of pile yarns, i.e. additional yarns that are floatingly entrained in the fabric of one or both outer layers. The yarns of the intermediate layer are usually drawn from one of the two outer layers at the connection point and extend through the interior of the inflatable chamber to the opposite outer layer.

[0025] In principle, such an intermediate layer can have a woven structure or simply consist of a plurality of threads which extend in parallel but are not connected to one another within the layer.

[0026] Since the yarns repeatedly leave and re-enter the fabric composite in each individual layer, the number of yarns in each layer will vary depending on the surface area of ​​the layer.

[0027] Overall, bends / curves, folds and / or bulges of the outer layer of the air bag can be formed in this way.

[0028] Preferably, the airbag has at least three superimposed layers in the inflatable chamber at least partially, wherein an intermediate layer is located between two outer layers that seal the airbag relative to the surrounding environment. Here, the intermediate layer extends freely through the corresponding inflatable chamber interior between its connection points on the two outer layers.

[0029] During the manufacture of the side airbag, the intermediate layer is directly woven into one with the remaining layers of the airbag in the region of the corresponding inflatable chamber. In particular, the intermediate layer has a woven structure.

[0030] Preferably, in the corner region of the airbag, at at least one connection point, the intermediate layer extends from one of the outer layers through the interior of the airbag to the opposite outer layer, so that two support rods, between which the corner region is located, adjoin each other at an angle not equal to 0° (and 180°) in the inflated state. In particular, the two inflatable chambers are a support rod close to the floor and a vertical support rod on one side of the airbag.

[0031] The angle is, for example, in the range of 90°, so that the corner region runs in a sharply curved manner.

[0032] In this case, the intermediate layer acts as an inner limiting band which predetermines the position of the outer layers relative to one another in the inflated state of the airbag.

[0033] Preferably, a plurality of intermediate layers are provided which follow one another along the corner region in the longitudinal direction from one inflatable chamber to another.

[0034] The intermediate layer predetermines the position of the outer layers relative to one another in the inflated state of the airbag, thereby also forcing the bend in the corner region to reach a desired angle.

[0035] For example, the inner side of the curvature of the corner region is pleated by the intermediate layer and is thus constricted, which automatically leads to a curvature in the corner region.

[0036] In the corner region, there can be a plurality of connection points for the intermediate layer on the inner side of the bend and on the opposite outer side of the bend of the airbag, wherein the connection points are spaced further apart from one another on the outer side of the bend than on the inner side of the bend. This arrangement results in a folding of the inner side of the bend and thus in a curvature of the corner region.

[0037] In a preferred variant, the intermediate layer in the corner region is designed to be flat and is extended by an angle not equal to 0°, in particular by 90°, between the connection points on the inner side of the bend and the outer side of the bend. If there are a plurality of intermediate layers in the corner region, only one, a plurality of or all of the intermediate layers can be extended by an angle, wherein different angles can be selected for different intermediate layers. This design also results in an arcuate shape of the corner region and folds on the inner side of the bend.

[0038] Preferably, the connection points are each elongated. In the case of an intermediate layer rotated by 90°, the connection points extend, for example transversely to the vertical direction on the inner side of the bend in the inflated airbag, and extend in the vertical direction on the outer side of the bend.

[0039] In general, additional seams, in particular curved seams and pleats, in the corner region can be dispensed with by one or more of the above-mentioned measures.

[0040] The vehicle occupant protection system preferably includes at least one gas generator which provides filling gas for an airbag and is fastened to the vehicle floor.

[0041] For example, the gas generator can be connected to the airbag support rod close to the floor, for example, via an inlet at the end of the support rod facing away from the vehicle seat. In order to inflate the airbag as quickly as possible, two gas generators can be provided. These gas generators are then arranged, for example, in the region of the two longitudinal ends of the support rod close to the floor.

[0042] The flow connection can be made in such a way that the gas generator is connected to the support rod directly or via an optionally flexible gas supply line leading to the airbag and in flow connection with the support rod. The latter case provides the option of arranging one or more gas generators remote from the airbag.

[0043] As an alternative or in addition to the above-mentioned applications, an intermediate layer can form a protective layer for the outer layers in the connection area of ​​the gas generator. In this way, the time consumption of arranging such a protective layer in the gas device can be reduced. In this case, the intermediate layer forms, for example, a kind of pocket around the outflow opening of the gas generator, which guides the filling gas flowing out of the gas generator into the gas bag and prevents a direct flow into the two outer layers. Such a pocket can also be composed of two or more intermediate layers, for example.

[0044] Outside the corner regions, in the inflatable chambers, the intermediate layer may extend through the respective chamber along the longitudinal extension of the chamber, which helps to stabilize in particular the support rods. However, it is also possible to arrange the intermediate layer only in the corner regions of the airbag.

[0045] In general, all layers, ie the outer layers and the middle layer, are woven together in one piece. The edge region of the airbag, in which the outer layers merge together, contains in particular all the yarns of the two outer layers and the middle layer.

[0046] For additional stability, the airbag can be tightened / reinforced via at least one restraining strap extending obliquely from the longitudinal end of the restraining chamber to the vehicle floor. Preferably, such a restraining strap is arranged on both sides of the airbag (viewed from the relevant vehicle seat, in the transverse direction).

[0047] This tensioning / strengthening can also be achieved between the individual support rods.

[0048] If the airbag is reinforced by at least one limiting band extending outside the inflatable chamber, the limiting band can be made of a single layer of fabric. Therefore, the limiting band does not have to be designed to be inflatable. In this case, the limiting band can be made separately and sewn to the airbag, which saves material and simplifies the process. It is also conceivable to completely omit such a limiting band. As an alternative, of course, the limiting band can also be woven into one piece with the rest of the airbag and optionally designed as an inflatable chamber.

[0049] The total volume of the airbag may be about 30L, for example.

[0050] The gas generator and / or the folded airbag are, for example, accommodated in a receiving section in the vehicle floor before activation, so that they are not visible to the vehicle occupants in the vehicle cabin. For example, a complete airbag module including the airbag and one or more gas generators can be accommodated in the floor. In order to hide the airbag module before activation, the airbag module can, for example, be mounted on a rotatable plate arranged above the receiving section, so that the airbag module sinks into the floor before activation and pivots upwards in the restrained state before the filling gas flows into the airbag.

[0051] In another embodiment, an additional restraint chamber is provided, which is arranged between the restraint chamber and the vehicle floor in parallel with and immediately adjacent to the restraint chamber in the fully inflated state of the airbag. The additional restraint chamber is preferably located in the same plane as the restraint chamber and the vertical support rod (adjacent to the side of the restraint chamber). Here, the additional restraint chamber helps to reliably catch the legs of the vehicle occupant and avoid overstretching.

[0052] In particular, at least one overflow opening is arranged between the restraining chamber and the additional restraining chamber, through which the filling gas flows from the restraining chamber into the additional restraining chamber. In this case, the additional restraining chamber is preferably inflated only via a flow connection with the restraining chamber, so that the filling gas always flows through the restraining chamber into the additional restraining chamber. Thus, the additional restraining chamber is in principle only deployed after the restraining chamber has at least started to be inflated.

[0053] The inner volume of the restraint chamber is separated from the inner volume of the additional restraint chamber by a partition, in which the at least one overflow opening is formed. The partition preferably extends over the entire length of the additional restraint chamber in the transverse direction of the vehicle. For example, a plurality of overflow openings are arranged along the connecting line, so that the additional restraint chamber can be inflated quickly and evenly over its entire length.

[0054] Preferably, the additional restraining chamber is folded, in particular rolled up, into a package separate from the restraining chamber before it is inflated, so that the additional restraining chamber is unfolded and inflated later than the restraining chamber. Preferably, the additional restraining chamber is unfolded after the rest of the airbag is unfolded and assumes a three-dimensional contour. In this way, it is ensured that the additional restraining chamber does not hinder the unfolding and inflation of the support rod.

[0055] The additional restraining chamber is preferably woven into one piece with the rest of the airbag.

[0056] In one possible variant, the at least one overflow opening is formed by a weaving pattern in the separator, which has a lower thread density locally, thus producing a higher permeability at these locations, so that the filling gas can pass from the confinement chamber into the additional confinement chamber. In another variant, the at least one overflow opening is formed by a woven-in double-layer section in the separator, which is otherwise woven into one piece, through which the filling gas can overflow from the confinement chamber into the additional confinement chamber.

[0057] In order to position the additional restraining chamber quickly and reliably in the desired position, the additional restraining chamber can be fixed to the laterally adjacent vertical support rods via lateral fabric sections, at least before full inflation. The fabric sections are preferably non-inflatable. However, it should be noted that the fabric sections do not exert any significant forces on the support rods, so that the three-dimensional contour of the airbag is affected as little as possible by the additional restraining chamber.

[0058] For example, the fabric section is a woven-in single-layer section which is also woven into one piece with the rest of the airbag.

[0059] Preferably, the fabric section has a structure, in particular a weakened area, which expands when lateral tensile forces act on the fabric section. When such forces occur, the structure yields, in particular by the expansion of the weakened area. In this way, lateral tensile forces acting on the vertical support rods can be avoided. The contraction of the additional restraining chamber in the transverse direction of the vehicle caused by the inflation of the additional restraining chamber is compensated by the increase in the length of the fabric section in this direction. As a result, no significant additional tensile forces acting on the vertical support rods are generated by the additional restraining chamber.

[0060] For example, the structure comprises one or more slits or perforations on the surface of the corresponding fabric section.The structure can advantageously be produced simultaneously with the laser cutting of the airbag after weaving.

[0061] As an alternative or in addition to the fabric segments, a limiting band can be provided which extends between the side edges of the additional restraining chamber and the respectively adjacent vertical support rod and positions the additional restraining chamber and optionally stabilizes the additional restraining chamber. However, it should also be noted here that the length of the limiting band in its position is selected so that substantially no lateral tensile forces are transmitted to the vertical support rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] The present invention is described in detail below with reference to a number of exemplary embodiments.

[0063] Figure 1 is a schematic perspective view of an airbag of a vehicle occupant protection system of the present invention according to a first embodiment;

[0064] Figure 2 is a schematic perspective view of an airbag of a vehicle occupant protection system of the present invention according to a second embodiment;

[0065] Figure 3 yes Figure 2 A schematic diagram of a vehicle occupant protection system shown in a restrained state;

[0066] Figure 4 yes Figure 2 The flat unfolded blank of the airbag is shown;

[0067] Figure 5 is a schematic perspective view of an airbag of a vehicle occupant protection system of the present invention according to a third embodiment;

[0068] Figure 6 yes Figure 5 The flat unfolded blank of the airbag is shown;

[0069] Figure 7 is a schematic perspective view of an airbag of a vehicle occupant protection system of the present invention according to a fourth embodiment in an inflated state;

[0070] Figure 8 yes Figure 7 A front view of the air bag is shown;

[0071] Fig. 9 yes Figure 7 A schematic side view of a variant of the airbag is shown;

[0072] Fig.10 yes Figure 7 A schematic detailed illustration of the layers of the airbag shown in the corner region of the airbag;

[0073] Fig.11 and 12 is a schematic diagram of the connection points of the middle layer on the two outer layers of the airbag;

[0074] Fig.13 is a schematic perspective view of a vehicle occupant protection system of the present invention according to a fifth embodiment;

[0075] Fig.14 yes Fig.13 A schematic side view of the airbag is shown;

[0076] Fig.15 yes Fig.13 A schematic diagram of the airbag shown before inflation of the additional restraint chamber;

[0077] Fig.16 yes Fig.13 A schematic diagram of the airbag shown after the additional restraint chamber is inflated; and

[0078] Fig.17 and 18 is from Fig.13 Schematic diagram of the overflow port from the restraint chamber of the airbag to the additional restraint chamber is shown. DETAILED DESCRIPTION

[0079] The same, similar or identically functioning components of all embodiments are marked with the same reference numerals or with a value increased by 100. For the sake of clarity, not all identical components are marked with reference numerals.

[0080] Figure 1 A vehicle occupant protection system 10 is shown, which includes an airbag 12 according to a first embodiment in a fully inflated state, which is designed to protect the legs of a vehicle occupant 14 sitting on a vehicle seat 16 (see FIG. Figure 3 ).

[0081] The airbag 12 includes a plurality of tubular chambers 18 that are fluidly connected to one another and together form a three-dimensional wedge-shaped frame 20 .

[0082] The intermediate spaces between the tubular chambers 18 are open. In this embodiment, the airbag 12 is constituted by the tubular chambers 18 only.

[0083] One of the tubular chambers 18 is designed as a restraining chamber 22 and has in this example a diameter d1 which is greater than the diameter d of the remaining tubular chambers 18. The restraining chamber 22 is arranged here in the upper region of the airbag 12 on the uppermost (with reference to the vertical direction V) and the rearmost (with reference to the longitudinal direction L pointing away from the vehicle seat 16) tubular chamber 18 and extends in a transverse direction Q of the vehicle seat 16 perpendicular to the longitudinal direction L and the vertical direction V.

[0084] The airbag 12 is oriented such that the restraint chamber 22 is located on that side of the airbag 12 which faces the vehicle seat 16 .

[0085] The remaining tubular chambers 18 form support rods 24 which ensure the dimensionally stable nature of the airbag 12. The frame 20 is designed such that the airbag 12 itself is dimensionally stable in the inflated state.

[0086] In this example, two obliquely extending support rods 26 are provided, which are attached to the longitudinal ends 28 of the restraint chamber 22 and extend to the floor 30 of the vehicle.

[0087] Furthermore, two vertical support rods 32 are attached to the longitudinal ends 28 of the restraint chamber 22, which also extend to the floor 30. The opposite ends of the obliquely extending support rods 26 and the vertical support rods 32 are connected to each other by a support rod 34 close to the floor. The support rod 34 close to the floor forms a quadrilateral here, which rests on the floor 30. Furthermore, between the two vertical support rods 32, a further support rod 24 is arranged between the support rod 34 close to the floor and the uppermost crossbar connected to the restraint chamber 22.

[0088] In this example, the confinement chamber 22 protrudes in the longitudinal direction L by a length beyond the vertical support rod 32 .

[0089] The airbag 12 is in fluid communication with a gas generator 38 that provides filling gas to the airbag 12. The total filling volume of the airbag 12 may be, for example, about 30L.

[0090] In the inactive state, the airbag 12 and the gas generator 38 are arranged on the vehicle floor 30. For example, they are concealed in a receptacle in the floor (not shown), which receptacle is an airbag module, in which the gas generator 38 and the folded airbag 12 are located.

[0091] The airbag 12 is fixed to the floor 30 , for example, by means of fixing members 40 at the ends of the oblique support rods 26 and the vertical support rods 32 close to the floor, which are connected to corresponding fixing structures (not shown) on the floor 30 .

[0092] Figure 2 A second embodiment of the airbag 12 is shown. Here, in contrast to the first embodiment, the restraint chamber 22 is arranged above two vertical support rods 32 in the vertical direction V in alignment with these support rods, while the intermediate support rod 24 is omitted. The two vertical support rods 32 and the restraint chamber 22 thus form a kind of door, which is delimited on the back by two obliquely extending support rods 26.

[0093] Furthermore, the two support rods 34 extending in the longitudinal direction L close to the floor are connected to one another via a non-inflatable limiting belt 41 .

[0094] In this embodiment, two gas generators 38 are used, which are arranged here in the region of the support rods 34 close to the floor, in particular in the region of the longitudinal end of the rearmost support rod 34 close to the floor.

[0095] Figure 3 The air bag 12 is shown oriented relative to the vehicle occupant 14 in the restrained state. An inclined support rod 26 extends away from the vehicle seat 16 to the floor 30 and supports the air bag 12 on the floor 30 .

[0096] If a restraint situation occurs, the gas generator 38 is activated and inflates the airbag 12. At the same time, the airbag 12 is deployed in an arc from the receiving portion on the floor 30 toward the vehicle occupant 14 on the seat 16, so that the restraint chamber 22 reaches above the legs of the vehicle occupant 14 from above. Figure 3 As shown, the restraint chamber 22 captures the legs of the vehicle occupant 14 as they swing upward.

[0097] A support rod 34 disposed near the floor below the confinement chamber 22 or at Figure 1 The support rod 24 arranged above the airbag shown is provided, for example, to receive the heels of the vehicle occupant 14 when necessary and to prevent any movement of the legs. Figure 3 In the movement situation shown in , the vehicle occupant 14 is prevented from moving forward.

[0098] As an alternative, airbag 12 can be arranged in the region of a structure that is fixed to the vehicle and serve, for example, as a knee airbag.

[0099] Figure 4 Shows Figure 2 The blanks 42, 44 of the airbag 12 are shown. With the exception of the vertical support rods 32 and the front side 44 of the restraining chamber 22, the blank 42 is constructed from a single unitary piece of suitable airbag fabric.

[0100] The blank 42 is elongated and folded multiple times along the later longitudinal direction L to form the airbag 12. The folded sections are partially sewn together along the longitudinal direction L to form the respective tubular chambers 18. These seams are formed at Figure 2 In this way, an overflow port between each tubular chamber 18 is also realized.

[0101] For example, Figure 4 The middle right end 46 (which forms the restraint chamber 22 in the finished airbag) is folded along fold line I and connected to line II at the left end 48. The remaining blank is folded again along fold lines III and IV to form an obliquely extending support rod 26 and is sewn together with the end 46 in the region of fold line III.

[0102] The separate front side 44 is sewn together with the ends 48 , 46 to complete the vertical support rod 32 and the restraining chamber 22 .

[0103] In the region of the folding lines III, IV, suitable pleats 50 are generated by corresponding seams, which pleats define the angles between the individual tubular chambers 18 or support rods 24 and give the inflated airbag 12 the desired wedge shape (see FIG. Figure 2 and 5 ).

[0104] The limiting band 41 is formed by a section of the blank 42 which is not covered by another matching blank section.

[0105] Figure 5 and 6 A third embodiment of an airbag 12 and its blank 42 is shown. The main difference from the second embodiment is that the obliquely extending support rods are formed by non-inflatable limiting straps 41 .

[0106] Figure 6 Shows Figure 5 The blank 42 of the airbag 12 shown consists of only one fabric piece. As in the previous embodiment, the sections of the blank 42 are given the desired shape in a suitable manner by folding along suitable folding lines I, II, III, IV perpendicular to the longitudinal direction L and sewing the individual blank sections together, wherein the tubular chamber 18 is also produced. The limiting band 41 is formed integrally with the blank 42 and is already connected to the blank at its two longitudinal ends, so that no additional sewing steps are required. In this example, two blank sections are superimposed in the region of the limiting band 41, but are not connected together, so that an inflatable chamber is formed.

[0107] Figures 7 to 12A fourth embodiment of the airbag 112 is shown. In this example, at least the section of the airbag 112 including the inflatable chamber 18 together with the restraining chamber 22 and the plurality of support rods 124 is woven into one piece, ie, woven by an integral weaving process.

[0108] In this example, at least some of the inflatable chambers 18 are designed in three or more layers. At least one intermediate layer 162 extends between the two outer layers 160 that form the envelope of the airbag 112 and seal it off from the surrounding environment, and the intermediate layer extends freely through the interior 164 of the corresponding inflatable chamber 18 (see Fig.10 ).

[0109] All layers 160 , 162 are formed simultaneously during the weaving process and form a single textile layer in the edge region 166 of the chamber 18 in which the two outer layers 160 are in contact with one another.

[0110] The intermediate layer 162 is composed of warp threads and / or weft threads which alternate between the two outer layers 160 and, as an alternative or in addition, also of pile threads (not shown) which float in the two outer layers 160 .

[0111] In this case, in the confinement chamber 22 , a single intermediate layer 162 extends freely through the interior 164 of this confinement chamber and, between the two outer layers 160 , substantially through the entire confinement chamber 22 .

[0112] In all examples, the intermediate layer 162 may be constructed from a plurality of parallel individual yarns (warp yarns, weft yarns or pile yarns) or from a fabric composed of warp yarns, weft yarns and / or pile yarns.

[0113] In the embodiment shown here, all inflatable chambers 18, including the restraining chamber 22 and the support rods 124, are constructed in this way (see Fig.10 ) However, it is of course also conceivable to provide the intermediate layer 162 only in some of the chambers 18 .

[0114] In the variant of the airbag 112 shown here, a first support rod 124 extends as a support rod 134 close to the floor parallel to the vehicle floor 30 to an inflatable corner area 168 on one side of the airbag 112. A further support rod 124, which forms a vertical support rod 132 and extends approximately vertically upward from the floor 30, is connected to the opposite side of the corner area 168. The support rod 124 extends approximately perpendicularly to the plane formed by the two support rods 134, 132 (in Figure 7 The restraint chamber 22 (entering the drawing) is arranged at the upper free end of the support rod 132.

[0115] The two support rods 132, 134 together with the corner area 168 located between them are arranged in the same way on opposite sides of the airbag 112 with reference to the transverse direction Q of the airbag 112. The vertical support rods 132 each terminate at two opposite ends 169 of the restraint chamber 22 and directly transition into the restraint chamber 22 (see Figure 8 ).

[0116] In the corner region 168, the two support rods 132, 134 on one side of the airbag 112 enclose an angle α between them, here approximately 90° (see, for example Figure 7 and 9 ). The airbag 112 thus forms a bend about the angle α in the corner region 168 .

[0117] This curvature of the corner region 168 is achieved in particular by one or more intermediate layers 162 which extend through the interior of the corner region 168 and connect the two outer layers 160 to one another in the corner region 168 .

[0118] like Fig.10 As shown, in the corner region 168, there are a plurality of (here three) intermediate layers 162 one after another in the direction from the support rod 134 close to the floor to the vertical support rod 132, which extend from one of the outer layers 160 to the opposite outer layer 160. These intermediate layers 162 form inner limiting bands 170, which connect the outer layer 160 on the inner side 172 of the curvature of the corner region 168 to the opposite outer layer 160 on the outer side 174 of the curvature of the corner region 168. When the airbag 112 is inflated, the position and length of these inner limiting bands 170 force the corner region 168 to have the desired curvature.

[0119] In the inner limiting band 170, the yarn from one of the outer layers 160 extends from a connection point 176 in the outer layer 160 through the interior 164 of the inflatable chamber 18 to a connection point 176 on the opposite outer layer 160 and enters its textile composite material there. At the next connection point 176 of the outer layer 160, the yarn leaves the textile composite material of the outer layer 160 and extends through the interior of the corner area 168 as the next inner limiting band 170 until it enters the textile composite material of the opposite outer layer 160 again at another connection point 176.

[0120] In this way, a plurality of inner limiting bands 170 extend from successive starting points 176 between two outer layers 160 forming the inner bend side 172 and the outer bend side 174. In this case, the number of threads and the thread density of the outer layers 160 are respectively varied. The inner limiting bands 170 are only formed when leaving the connection point 176 and end at the corresponding connection point 176 on the opposite outer layer 160.

[0121] The total number of connection points 176 defines the total number of inner limiting bands 170. Thus, the number of connection points 176 on both outer layers 160 is equal.

[0122] The connection points 176 of the inner limiting band 170 are closer together on the inner side 172 of the bend than on the outer side 174 of the bend. Due to this arrangement, the inner side 172 of the bend is pleated, which effectively causes the inner side 172 of the bend to converge in the corner area 168, thereby forming a bend around the angle α between the two support rods 132, 134.

[0123] The inner limiting band 170 is designed to be flat in this example and can be, for example, over the entire depth of the corner region 168 (in Fig. 9 and 10 The inner surface of the drawing is perpendicular to the drawing plane.

[0124] Therefore, the connection point 176 is elongated (see Fig.10 and 11 ).

[0125] Fig.11 and 12 The connection points 176 on the inner side 172 of the bend are shown to be arranged transversely to the vertical direction V ( Fig.11 ), while the connection point 176 on the outer side 174 of the bend is positioned along the vertical direction V ( Fig.12 ). Thus, the inner limiting strap 170 is rotated between the inner side 172 of the bend and the outer side 174 of the bend by an angle, here approximately 90°. This additionally facilitates the desired bend of the corner region 168 and increases the stability of the airbag 112. Of course, other arrangements are also conceivable.

[0126] In the example shown, similar to the above-described embodiments, the airbag 112 has two limiting straps 41, which connect the restraining chamber 22 at its ends 169 to an end region 178 of the support rod 134 on the floor side opposite the corner region 168. In a variant, the limiting straps 41 are made of a standard single-layer airbag fabric. They are then cut separately and sewn together with the airbag 112. As an alternative, they can also be woven into one piece with the rest of the airbag 112 and optionally designed as an inflatable chamber.

[0127] In this example, the fastening element 40 connecting the gas generator 38 to the floor panel 30 is also woven into one piece with the airbag 112 and forms part of the edge region 166 .

[0128] As in the previous embodiment, there are one or more gas generators 38 providing filling gas for the airbag 112. The aforementioned protective layer is also composed of one or more intermediate layers 162 woven into one piece with the rest of the airbag 112 at the location where the gas generator 38 extends into the inflatable chamber 18 of the airbag 112.

[0129] In principle, one or more intermediate layers 162 can be arranged between two outer layers 160 in an inflatable chamber 18 (which is, for example, a support rod 124, a corner area 168 or a constraining chamber 22), wherein in particular multiple inner layers 162 can be arranged one after the other along the longitudinal extension of the corresponding inflatable chamber 18.

[0130] The features of each embodiment can be freely combined or interchanged according to the judgment of professional and technical personnel.

[0131] exist Figures 13 to 18 In the fifth embodiment of the vehicle occupant protection system 10 shown in FIG. 8 , the airbag 112 has an additional restraint chamber 180 in addition to the restraint chamber 22 .

[0132] The additional restraint chamber 180 extends parallel to the restraint chamber 22 when the airbag 112 is fully inflated, and extends directly adjacent to and below the restraint chamber 22, i.e., between the restraint chamber 22 and the floor 30. With reference to the vertical direction V and the longitudinal direction L, the additional restraint chamber 180 is located in the same plane as the restraint chamber 22 and the vertical support rod 124.

[0133] The additional restraint chamber 180 acts on the foot and shin of the vehicle occupant 14 from above and blocks the legs of the vehicle occupant 14, just like the restraint chamber 22, when the vehicle collides. Therefore, the function of the airbag 112 is the same as that in the above-mentioned embodiment.

[0134] The additional restraint chamber 180 is approximately as long as the restraint chamber 22 with reference to the vehicle transverse direction Q and has a similar height with reference to the vertical direction V in the fully inflated state.

[0135] The additional restraining chamber 180 is connected securely and permanently in the vehicle transverse direction Q over its entire inflatable area via a spacer 184 .

[0136] A plurality of overflow openings 186 are designed in the partition 184, through which the filling gas flows from the restraining chamber 22 into the additional restraining chamber 180 when the restraining chamber 22 is filled. The overflow openings 186 are the only flow connection between the additional restraining chamber 180 and the rest of the airbag 112, so that the filling gas can only flow into the additional restraining chamber 180 via the restraining chamber 22.

[0137] In this example, the additional restraint chamber 180 is woven integrally with the remaining integrally formed section of the airbag 112 .

[0138] Fig.17 A variant is shown in which the overflow opening 186 is realized by a weaving pattern in the separator 184 which has a lower thread count in certain areas, so that the fabric has a higher air permeability at these locations.

[0139] Fig.18 A variant is shown in which the overflow 186 is formed by weaving double-layer sections into the otherwise integrally woven separator 184 , which form the inner side of the overflow 186 and between which the filling gas can overflow from the confinement chamber 22 into the additional confinement chamber 180 .

[0140] In this example, before inflation, the additional restraining chamber 180 is rolled into a package 187 separated from the restraining chamber 22 along the vertical direction V and is fixed in this rolled state by a retaining device (not shown) provided with a weakened area. The retaining device is only released when sufficient filling gas begins to flow from the restraining chamber 22 through the overflow port 186 into the still rolled additional restraining chamber 180.

[0141] In this example, the additional restraining chamber 180 is laterally connected to the vertical support rod 124 at each side 190 of the additional restraining chamber 180 by two fabric segments 188 .

[0142] Here, the two fabric sections 188 are single layer regions that are woven integrally with the remainder of the airbag 112 and are non-inflatable.

[0143] To prevent the three-dimensional contour of airbag 112 from being deformed by additional restraining chamber 180 , lateral tensile forces F acting on fabric sections 188 that occur when additional restraining chamber 180 contracts during filling or inflation are absorbed by a structure 191 in each fabric section 188 .

[0144] exist Fig.15 and 16 An example of this is shown in . Fig.15 and 16 The left side of each shows a first variant, while Fig.15 and 16 The second variant is shown on the right side of FIG.

[0145] In a first variant, the structure 191 consists of weakened areas 192 in an upper end region 193 with reference to the vertical direction V, which are introduced between the fabric section 188 and the adjacent vertical support rods 124 and into the adjacent side edges 190 of the fabric section 188 and the additional restraining chamber 180. In addition, a further weakened area 196 is provided on the surface of the fabric section 188 at a lower end 194.

[0146] During the inflation of the support rod 124, the weakened areas 192, 196 remain intact ( Fig.15 ). However, when the additional restraint chamber 180 begins to inflate and generates a tensile force F acting on the fabric section 188 in the vehicle transverse direction Q in the direction of the side toward the additional restraint chamber 180, the weakened areas 192, 196 are stressed and ruptured. Fig.16 As can be seen in the figure, the fabric section 188 extends along the vehicle transverse direction Q and compensates for the length difference caused by the contraction of the additional restraint chamber 180 when it is inflated along the vehicle transverse direction Q. Therefore, no significant force acts on the vertical support rod 124, so that the airbag 112 has substantially the same three-dimensional contour in the fully inflated state as when there is no additional restraint chamber 180.

[0147] In a second variant, a single weakened area 198 ( Fig.15 As described for the first variant, if a tensile force F is generated in the vehicle transverse direction Q in the direction of the additional restraint chamber 180, the weakened area 198 opens to form a through opening that allows the fabric section 188 to expand laterally, thereby compensating for the tensile force F ( Fig.16 ).

[0148] In this example, the structure 191 (here the weakened areas 192 , 196 , 198 ) is produced by laser cutting in the same process step as the tailoring of the airbag 112 after weaving, which is also performed here by laser cutting.

[0149] like Fig.13 As shown, there may be additional, here obliquely extending, limiting straps 200 from the additional restraint chamber 180 to the corresponding adjacent vertical support rod 124 for stabilizing the position of the additional restraint chamber 180 in the gas-filled airbag 112. The limiting straps 200 are designed so that no significant tensile forces are transmitted into the vertical support rod 124.

Claims

1. A vehicle occupant protection system (10), comprising an airbag (12; 112) for protecting the legs of a vehicle occupant (14), the airbag (12; 112) being arranged in a folded manner on a vehicle floor (30) in front of an associated vehicle seat (16) before the vehicle occupant protection system (10) is activated, and the airbag is deployed from the floor (30) in front of the vehicle seat (16) in a restrained state, the airbag (12; 112) comprising a plurality of tubular inflatable chambers (18) in fluid communication, which chambers are three-dimensionally arranged in the inflated state. The invention relates to a vehicle body having an inflatable chamber (18) and a plurality of chambers (18) forming a support rod (124) of the airbag (12; 112), and at least one chamber (18) forming a restraint chamber (22) in the upper region of the airbag (12; 112), the restraint chamber (22) being arranged directly in front of the tibia region, knee region or pelvic region of the vehicle occupant (14) in the fully inflated state of the airbag (12; 112), and at least the section of the airbag (12; 112) containing the inflatable chamber (18) being woven into one piece.

2. The vehicle occupant protection system (10) according to claim 1, wherein: The airbag (112) has at least three superimposed layers (160, 162) at least partially in the inflatable chamber (18), wherein a middle layer (162) is located between two outer layers (160) which seal the airbag (112) from the surrounding environment.

3. The vehicle occupant protection system (10) according to claim 2, wherein: The intermediate layer (162) has a woven structure.

4. The vehicle occupant protection system (10) according to claim 2 or claim 3, wherein: In a corner region (168) of the airbag (112), at at least one connection point (176), the intermediate layer (162) extends from one of the outer layers (162) through the interior of the airbag (112) to the opposite outer layer (160), so that the two support rods (124) are adjacent to each other at an angle (α) not equal to 0° in the inflated state, and the corner region (168) is located between the two support rods.

5. The vehicle occupant protection system (10) according to claim 4, wherein: The inner side (172) of the curved portion of the corner region (168) is pleated by the intermediate layer (162).

6. The vehicle occupant protection system (10) according to claim 5, wherein: In the corner area (168), there are multiple connection points (176) for the intermediate layer (162) on the inner side (172) of the bend and on the opposite outer side (174) of the bend of the airbag (112), and these connection points (176) are spaced farther apart from each other on the outer side (174) of the bend than on the inner side (172) of the bend.

7. The vehicle occupant protection system (10) according to any one of claims 4 to 6, wherein: The intermediate layer (162) is designed to be flat in the corner region (168) and extends rotated by an angle not equal to 0°, in particular by 90°, between a connection point (176) on the inner side (172) of the bend and on the outer side (174) of the bend.

8. The vehicle occupant protection system (10) according to any one of claims 2 to 7, wherein: In the connection region of the gas generator (38), the intermediate layer (162) forms a protective layer for the outer layers (160).

9. The vehicle occupant protection system (10) according to any one of claims 2 to 8, wherein: Outside the corner regions (168) in the inflatable chambers (18), the intermediate layer (162) extends through the respective chamber (18) along the longitudinal extension of the chamber (18).

10. The vehicle occupant protection system (10) according to any one of claims 2 to 9, wherein: All layers (160, 162) are woven into one another.

11. The vehicle occupant protection system (10) according to any one of the preceding claims, wherein: The airbag (112) is reinforced via at least one limiting strap (41) extending outside the inflatable chamber (18) and the limiting strap (41) is composed of a single layer of fabric.

12. The vehicle occupant protection system (10) according to any one of the preceding claims, wherein: An additional restraint chamber (180) is provided, which is arranged parallel to the restraint chamber (22) and immediately adjacent to the restraint chamber (22) between the restraint chamber (22) and the vehicle floor (30) when the airbag (112) is in a fully inflated state.

13. The vehicle occupant protection system (10) according to claim 12, wherein: At least one overflow port (186) is arranged between the confinement chamber (22) and the additional confinement chamber (180), and the filling gas flows from the confinement chamber (22) into the additional confinement chamber (180) through the overflow port.

14. The vehicle occupant protection system (10) according to any one of claims 12 and 13, wherein: The additional restraining chamber (180) is fixed to the vertical support rod (124) via lateral fabric sections (188), at least before it is completely filled with air.

15. The vehicle occupant protection system (10) according to claim 14, wherein: The fabric section (188) has a structure (191), in particular a weakened area (192, 196, 198), which expands when a lateral tensile force (F) acts on the fabric section (188).

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