Cover for an airbag of a vehicle occupant restraint system and method for packaging an airbag in the cover

Abstract

The invention relates to a flexible casing for an airbag (16) of a vehicle occupant restraint system (10), the casing having a receiving cavity for a gathered airbag package (14) formed by a receiving pocket (104) and an airbag package fastening device (124), a gas generator fastening device (114) formed by a protruding retaining lug (112), and at least one fastening section (130) for fastening the airbag module (12) to the vehicle. For inserting the airbag package (14) into the casing (20), an intermediate casing consisting of a connected fabric is used, in which the airbag package (14) and the gas generator (18) are enclosed together. The assembly consisting of the intermediate casing, the airbag package (14) and the gas generator (18) is pushed into the casing (20). The intermediate casing is then pulled out again between the casing (20) and the airbag package (14).

Description

Technical Field

[0001] The invention relates to a casing for an airbag of a vehicle occupant restraint system and a method for packaging an airbag in the casing. Background Art

[0002] Airbags are used very successfully to protect vehicle occupants. They must be protected from environmental influences before they are deployed in the vehicle cabin. In order to reduce weight and structural volume, efforts are being made to replace the rigid module housing with a covering consisting of airbag fabric or film. Summary of the invention

[0003] The object of the present invention is to simplify the insertion of a combined airbag into a covering and the fastening of the airbag module in a vehicle by providing a novel covering and a method for packaging an airbag.

[0004] The object is achieved with a cover having the features of claim 1. A flexible cover for an airbag of a vehicle occupant restraint system has a receiving cavity for a gathered airbag package formed by a receiving pocket. In addition, the cover has an airbag package fixing device, a gas generator fixing device formed by protruding retaining lugs and at least one fixing section for fixing the airbag module to the vehicle. By inserting into the receiving pocket, the gathered airbag package can be placed in the cover in a simple manner. The airbag package can be reliably held in the receiving pocket in a folded state via the airbag package fixing device. The gas generator fixing device allows, on the one hand, the cover to be fastened to the gas generator and, on the other hand, if necessary, the folded neck connected to the blowing end of the airbag can be held in position. The fixing section makes it possible to simply fix the entire airbag module with the gathered airbag and cover to the vehicle. According to the invention, all the essential aspects of fixing the airbag package, gas generator and airbag module to the cover on the vehicle can be formed in this way, which simplifies handling and reduces the number of individual components used.

[0005] The cover is preferably made completely of airbag fabric. This allows simple and economical production and reduces weight and installation space. If the sections of the cover are to be sewn together, then of course additional sewing material can be used. However, connections by welding or gluing are also conceivable.

[0006] The covering according to the invention is particularly suitable for an airbag module which is arranged on a roof frame below the vehicle roof above the front passenger side in order to provide protection for the front passenger.

[0007] In order to reduce the number of individual blanks of the casing, the retaining lugs can be integrated into the receiving pocket and preferably at the edge opposite the base of the receiving pocket.

[0008] The airbag package fastening device can be formed on the cover in a simple manner by providing at least one pair of first and second fastening elements that engage one another and form a plug connection, in particular in the form of a hook and a hook loop. The hook preferably has the shape of an arrow with two lateral undercuts that can engage the edge of the hook loop.

[0009] Not only the first fixing element, but also the second fixing element is preferably completely formed by the material of the covering, in particular by the airbag fabric. It has been proven that a simple plug-in of the fixing element is sufficient to hold the airbag package on the covering without the need for an additional hook-and-loop connection, adhesive connection or welding connection.

[0010] Preferably, two pairs of first fixing elements and second fixing elements are provided, and these fixing elements can be arranged side by side in a direction parallel to the bottom of the receiving bag.

[0011] The fastening element serves, for example, to hold a belt section of the airbag package fastening device in position, which belt section fastens the airbag package in the receiving pocket.

[0012] Preferably, the airbag package comprises: a main package in which the restraining part of the airbag constituting the majority of the airbag volume is gathered; and a connecting section in which only the neck of the airbag is folded. The neck is preferably much narrower than the restraining section in the direction parallel to the bottom of the accommodation bag and transverse to the longitudinal direction of the module and shorter than the restraining section in the longitudinal direction of the module, so that the connecting section is shorter and narrower than the main package.

[0013] The belt section extends, in particular, through an opening of the receiving pocket on the outside so that it can rest against an edge of the airbag package, in particular a main package, and hold the airbag package in the receiving pocket.

[0014] The belt section can be transferred into the receiving bag in one piece, particularly on the edge of the receiving bag opposite to the bottom. In this way, the belt section can constitute the section of the first blank.

[0015] For example, two band sections may be provided, which form the sides of a U-shaped stirrup, which is formed in particular by a U-shaped cutting line, which separates the stirrup from one of the retaining lugs. The cutting line may be simply placed in the flat, unfolded blank.

[0016] The second fastening element, ie the hook, is preferably formed in a bridge section of the stirrup which connects the two lateral belt sections, ie in the middle bridge of the “U”.

[0017] The encapsulation preferably comprises two separate blanks connected to one another. In this case, the gas generator fastening device can be formed in the first blank like the receiving bag, while the fastening section can be formed in the second blank. The airbag package fastening device is preferably realized by sections of two blanks.

[0018] The first fixing element, ie the hook, is advantageously a part of the second blank and is cut out of a multi-layer section in order to obtain sufficient rigidity, whereas the second fixing element, ie the hook, is preferably formed in the single-layer first blank.

[0019] The second blank extends, in particular, on the first blank folded once to form the receiving pocket, for example parallel to the longitudinal extension of the bottom of the receiving pocket. The at least one first fixing element is formed in the second blank, while the at least one second fixing element is formed in the first blank.

[0020] The entire blanking of the two blanks of the casing can be produced by laser cutting.

[0021] The covering is preferably formed partially and in particular completely from a plurality of layers of the airbag fabric in the second blank. The edges of the respective sections are produced by laser cutting, wherein the plurality of layers are welded to one another at the edges. The welding is carried out directly by laser cutting, so that further processing and fixing of the individual layers of the airbag fabric against one another can be omitted.

[0022] The entire first blank is preferably made of a single layer of material.

[0023] The receiving pocket, the retaining lugs and the stirrup can all be components of the first blank. The receiving pocket and the retaining lugs can be realized in that the first blank is folded back on itself, wherein the longitudinal edges connected to the folding line are partially connected to form the receiving pocket. The free section then forms the retaining lug. To form the stirrup, a U-shaped cutting line can be introduced into the first blank so that it separates one of the retaining lugs radially inside the cutting line, and the stirrup is produced between the cutting line and the outer edge of the first blank.

[0024] The bottom of the receiving bag preferably has a weakened area, which breaks when the airbag is deployed so that the airbag can come out of the covering. For example, holes can be punched in the material of the covering.

[0025] The gas generator fastening device can be fastened to the gas generator in a simple manner in that each holding lug of the gas generator fastening device has at least one fastening opening for a fastening screw of the gas generator.

[0026] Preferably, a locking screw is provided on the gas generator and a locking opening is provided in each of the retaining lugs, which is associated with the arrangement of the locking screw. In this way, a protection against incorrect assembly is achieved according to the principle of error proofing when inserting the airbag package with the assembled gas generator into the package.

[0027] The two retaining lugs can have different lengths when viewed from the bottom of the receiving pocket. In this way, the orientation of the gas generator about the longitudinal axis can be influenced by different effective spacings, for example, so that the gas generator is arranged in the encapsulation so that the fastening screws are oriented in the longitudinal direction of the module. Overall, the torsion of the gas generator in the finished airbag module can be influenced by the length of the two retaining lugs.

[0028] Preferably, a fastening section is formed on each side of the covering, which fastening section has, in particular, at least one fastening opening and a pre-fastening opening.

[0029] The two fastening sections are advantageously components of the second blank and in particular project laterally beyond the receiving pocket in order to allow simple installation of the airbag module on the vehicle.

[0030] The fastening sections can each have, for example, a fastening opening, through which the load-bearing screw connection is closed, and in particular additionally a pre-fastening opening, via which the fastening section can be pre-fastened to the vehicle, for example, via a fastening clamp. After the pre-fastening to the vehicle, a permanent, load-bearing screw connection to the vehicle frame can then be added.

[0031] The fastening clip is advantageously already inserted into the pre-fastening opening before the airbag module is mounted on the vehicle.

[0032] When the airbag is deployed, the airbag package fixing device is preferably kept closed like the gas generator fixing device, and the fixing section remains fixed on the vehicle. Therefore, when the airbag is deployed, the once closed fixing on the cover is not opened.

[0033] The above-mentioned object is also achieved by a method for packaging an airbag in a sheath, which has the steps specified in claim 17. In the method for packaging an airbag in a sheath, an airbag assembled as an airbag package, including a gas generator, and an intermediate sheath are prepared, which consists of connected, in particular rectangular textile pieces, the length of which corresponds to the total circumference of the airbag package and which have openings at both longitudinal ends for fastening to the gas generator.

[0034] The air bag package and the gas generator are enclosed in an intermediate jacket, so that the intermediate jacket surrounds the air bag package and the gas generator in the longitudinal direction of the module. The two longitudinal ends of the intermediate jacket are fastened to the gas generator.

[0035] The assembly consisting of the intermediate casing, the airbag casing and the gas generator is inserted into the casing so that the airbag casing is located partially, in particular with the main casing, in a receptacle of the casing.

[0036] The tundish is opened by releasing its two longitudinal ends from the gas generator.

[0037] Fasten one of the retaining lugs of the gas generator fastening device of the sheath to the gas generator.

[0038] The intermediate casing is then pulled out between the airbag casing and the casing, and the second retaining lugs of the casing are fastened to the gas generator in order to close the casing.

[0039] In this case, the casing or the intermediate casing can always be fastened to the gas generator by sliding the corresponding openings over the fastening bolts (and the set screws) of the gas generator. No gluing, welding, sewing or similar operations are necessary.

[0040] The tundish is completely removed from the assembly and can be reused without modification.

[0041] After the gas generator fastening has been closed, the airbag package fastening is preferably closed in a further step. Since the cover is already fastened to the gas generator and thus to the airbag package via the retaining lugs, the shape and position of the airbag package are already retained by the cover, so that the airbag package fastening can now be closed in a simple manner with accurate position.

[0042] In general, the gas generator is arranged in the airbag module such that its gas generating longitudinal axis is perpendicular to the module longitudinal direction of the airbag module, wherein the module longitudinal direction coincides with the deployment direction of the airbag out of the airbag module in the installed state of the airbag module and points approximately in the vehicle longitudinal direction.

[0043] In one possible embodiment of the invention, a vehicle occupant restraint system comprises an airbag module having a casing according to the invention as a module housing. The airbag module is mounted approximately in the center of the front passenger seat in the roof region on the front passenger side, viewed in the transverse direction of the vehicle, and has an airbag gathered into an airbag package, which in the restraint situation is deployed between the windshield and the front passenger in order to receive the front passenger. The airbag package held in the casing is arranged between the rotation axis of the sun visor of the vehicle and the windshield.

[0044] The airbag package comprises a main package and a connecting section, which connects the main package to a gas generator, wherein the main package and the connecting section form two separately assembled sections.

[0045] The gas generator is inserted directly into the blowing end of the airbag and is firmly connected to the airbag by, as explained, two opposite lugs of the airbag being placed with the fastening openings formed therein onto fastening screws protruding from the gas generator and thus closing the blowing opening in a gas-tight manner.

[0046] To fasten the airbag module to the roof frame, the gas generator is received in a cross-sectionally C-shaped receptacle of a module carrier fastened to the roof frame, but the vehicle cabin-side arms of the C-shaped receptacle do not protrude noticeably from the gas generator.

[0047] In the case of a restraint, the gas generator is activated and the filling gas first flows into the connecting section, where the neck of the airbag is gathered in a simple zigzag fold. The neck is thereby stretched out and, through the resulting volume increase, the still at least largely folded main bag - in which the restraint part of the airbag, including a large part of the airbag volume, is gathered - is moved out under the roof trim into the vehicle passenger compartment. The gas generator, the connecting section and the main bag are located in a straight line in the longitudinal direction of the module.

[0048] During deployment of the restraining portion of the airbag from the main package, the first free end of the airbag may initially still be restrained by the restraining strap connecting the first free end of the airbag to the gas generator.

[0049] The main package is gathered, for example, in such a way that the first free end is folded back to the blowing end. In addition, the two side edge sections of the restraining part are folded back toward the center and then rolled up. This ensures that the outer edge of the airbag, which extends from the blowing end to the second free end of the airbag, is filled first, which is located approximately in the transition from the windshield to the dashboard in the inflated state. In contrast, the filling gas does not initially flow into the inner edge of the airbag, which extends from the blowing end to the first free end of the airbag. This is achieved by the folds and the limiting strips of the restraining part of the airbag.

[0050] Starting from a certain filling level achieved after a first predetermined period of time after the activation of the gas generator, the limiting strap releases due to the acting tensile forces and the inner edge of the airbag and the first free end of the airbag are also fully inflated.

[0051] In the fully inflated state of the airbag, the first free end extends beyond the instrument panel toward the vehicle occupant and forms a collision surface between the first free end of the airbag and the blowing end of the gas generator on the side facing the vehicle occupant.

[0052] The airbag is essentially composed of three outer wall sections, wherein a first outer wall section extends from the blowing end to the second free end and forms a support surface for supporting on the windshield, a second outer wall section connects the first free end to the second free end and is located on and above the instrument panel in the inflated state, and a third outer wall section connects the first free end to the blowing end and forms a collision surface in the inflated state.

[0053] All features described here in conjunction with the present invention can be implemented independently of one another individually or in any suitable combination according to the judgment of a person skilled in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The present invention will be described in detail below with reference to the accompanying drawings by means of embodiments.

[0055] Figure 1 is a schematic perspective view of a vehicle occupant restraint system according to the present invention, which has an airbag module mounted on a vehicle roof;

[0056] Figure 2 yes Figure 1 A module bracket of the airbag module shown is mounted on the vehicle roof;

[0057] Figure 3 yes Figure 1 A top view of the airbag module shown;

[0058] Figure 4 yes Figure 3 The view shown, in which the sun visor is additionally shown;

[0059] Figure 5 Installed in the vehicle Figure 1 A schematic cross-sectional view of a vehicle occupant restraint system is shown;

[0060] Figure 6 yes Figure 1 a schematic exploded view of the airbag module shown;

[0061] Figure 7 It is mounted on the roof Figure 1 A schematic top view of the airbag module shown;

[0062] Figure 8 and 9 yes Figure 1 A schematic cross-sectional view of a vehicle occupant restraint system is shown prior to air bag deployment and during an initial air bag deployment phase;

[0063] Figures 10 to 17 yes Figure 1 A schematic cross-sectional view of the inflation process of an airbag of the airbag module shown from a state before activation of a vehicle occupant restraint system until the airbag is fully filled;

[0064] Fig.18 yes Figure 1 A schematic cross-sectional view of an air bag of a vehicle occupant restraint system including an embedded gas generator;

[0065] Fig.19 yes Figure 1 A top view of the third outer wall section of the airbag of the vehicle occupant restraint system, which is deployed in a planar manner in the uninflated state;

[0066] Figures 20 to 23 Insert the gas generator into Figure 1 A schematic diagram of the blown end of an air bag of a vehicle occupant restraint system;

[0067] Figures 24 to 27 yes Figure 1 The step of gathering an airbag of the vehicle occupant restraint system as viewed in a top view;

[0068] Fig.28 yes Figure 1 A schematic diagram of a clustered airbag package of a vehicle occupant restraint system is shown;

[0069] Fig.29 yes Fig.28 A schematic perspective view of the airbag package shown inserted into the cover;

[0070] Fig.30 yes Fig.29 A schematic top view of the illustrated package;

[0071] Fig.31 is a schematic perspective view of the package;

[0072] Figures 32 to 34 It is the insertion of the airbag package into the bag cover;

[0073] Fig.35 It is the detail of the air bag bag fixing device of the bag cover;

[0074] Fig.36 is a schematic cross-sectional view of an air bag package inserted into a folding device;

[0075] Fig.37 and 38 It is the closure of the gas generator fixing device of the package;

[0076] Fig.39 is a schematic overview of an alternative method for inserting an air bag package into a package;

[0077] Figures 40 to 44 is a schematic diagram of the steps of an alternative method for inserting an air bag package into a package. DETAILED DESCRIPTION

[0078] Figures 1 to 7 The structure of a vehicle occupant restraint system 10 is shown, which in this example is designed to protect a front passenger, in particular a passenger car, in the event of a frontal collision.

[0079] The vehicle occupant restraint system 10 includes an air bag module 12 (see in particular Figures 5 to 7 ), which comprises an airbag 16 that acts in the front and is grouped as an airbag package 14, and a gas generator 18 that provides a filling gas for inflating the airbag 16. The gas generator 18 is arranged in the airbag 16 and is therefore integrated into the airbag package 14.

[0080] The airbag package 14 and the gas generator 18 are accommodated in a flexible covering 20 (see, for example, Figure 7 and 29 ), which will be described in detail below and in Figures 1 to 6 The cover is omitted for clarity reasons.

[0081] In addition, a module support 22 is provided (see, for example, Figure 2 and 6 ), the airbag module 12 is fixedly mounted relative to the vehicle via the module carrier, for example, mounted on a roof frame 23 or other rigid component in the roof area of ​​the vehicle. The module carrier 22 is, for example, a sheet metal formed part.

[0082] The airbag module 12 is disposed at the lower portion of the roof guard plate 24 (see, for example, Figure 5 ), which is located between the windshield 26 of the vehicle and the rotation axis 28 or the suspension device 29 of the sun visor 30 as viewed in the longitudinal direction R of the vehicle. The sun visor 30 can be, for example, Figure 1 The sun visor 30 is pivoted about the rotation axis 28 as shown in FIG. The rotation axis 28 is not physically realized continuously. Instead, the sun visor 30 is pivotably fastened to the vehicle roof on two suspension devices 29 (see FIG. Figure 1 and 4 ), wherein the sun visor 30 can usually be unhooked at the one of the two suspension devices 29 on the inner side of the vehicle in order to fold it open laterally.

[0083] At least the gathered airbag package 14 and, if applicable, the gas generator 18 are located in front of the rotation axis 28 of the sun visor 30 in the vehicle direction R, viewed from the vehicle front to the vehicle rear.

[0084] The deployment direction E of the airbag 16 points in the direction of the front of the vehicle along the longitudinal direction R of the vehicle and initially extends approximately parallel to the roof and the windshield 26 .

[0085] The airbag module 12 is located approximately at the center above the passenger seat (not shown) on the passenger side when viewed in the vehicle transverse direction QF, so that the airbag 16 can receive the passenger in front. F Set away from the car door.

[0086] The module carrier 22 has a receptacle 32 which is C-shaped in cross section and surrounds the gas generator 18 at the gas generator-side end face of the airbag package 14 .

[0087] The gas generator 18 is a known, elongated tubular gas generator, from whose cylindrical outer side two fastening bolts 34 protrude radially. The fastening bolts 34 are located on the back side of the gas generator 18, and on the opposite front side, outflow openings (not shown) are provided, through which the filling gas leaves the gas generator 18 and passes directly into the airbag 16.

[0088] The gas generator 18 is arranged in the airbag module 12 such that its longitudinal axis extends transversely to the vehicle longitudinal direction R, approximately along the vehicle transverse direction QF and thus approximately perpendicularly to the module longitudinal direction M and the deployment direction E of the airbag 16. The module longitudinal direction M can be defined approximately by an extension of the diameter of the gas generator 18, which extends through the fastening bolt 34.

[0089] In the module carrier 22 , more precisely in the longitudinal side 36 of the C-shaped receptacle 32 between the two arms 38 of the C, a fastening opening 40 is provided (see Figure 2 ), fastening bolts 34 pass through these fastening openings to firmly fasten the gas generator 18 and the airbag package 14 to the module bracket 22. For example, the fastening bolts 34 can be fixed on the back side with nuts.

[0090] As a supplement to the two fastening bolts 34, a further bolt can be provided which forms a positioning bolt 42 (see, for example, Figure 7 A corresponding opening 44 is provided in the module support 22 (see Figure 2 ) This positioning screw 42 is used to prevent incorrect assembly of the gas generator 18 according to the error-proofing principle.

[0091] When the airbag 16 is deployed, filling gas flows from the gas generator 18 through the blowing end 46 into the airbag 16, which is fastened to the gas generator 18 as will be described in more detail below. Due to the pressure of the filled airbag 16, the roof trim 24 opens either at the weakened area or, for example, at the transition to the windshield 26 and allows the airbag 16 to emerge into the vehicle cabin. In this case, the roof trim 24 forms the lower limit of the ejection path for the airbag 16. The upper limit of this ejection path can be predetermined by the roof frame 23. In this example, there are no additional rigid guides, such as guide plates, between the airbag 16 and the roof trim 24.

[0092] The arm 38 of the C-shaped receptacle 32 on the vehicle passenger compartment side does not extend beyond the outer wall of the gas generator 18 in the vehicle longitudinal direction R and only increases the stability of the module bracket 22, so that this module bracket is only not significantly deformed during the deployment of the airbag 16, but does not help to guide the airbag 16 by direct contact with the airbag 16.

[0093] The deployed airbag 16 also does not come into contact with the sun visor 30 or its suspension 29 during its discharge into the vehicle passenger compartment due to its position on the roof frame 23 .

[0094] exist Figure 8 and 9 The initial deployment of the air bag 16 is illustrated in FIG.

[0095] Figures 10 to 17 The deployment and inflation of the air bag 16 is shown in greater detail. Figures 11 to 17 Can see the steering wheel in, but this steering wheel is only positioned on the side view selected for elaboration.In this example, air bag 16 is only deployed on the co-pilot side and beside the steering wheel.

[0096] Fig.10 Here, the initial state before the vehicle occupant restraint system 10 is activated is shown.

[0097] The airbag package 14 is first gathered under the closed roof trim 24. The airbag package 14 comprises two individually gathered or folded sections, namely a main package 48 and a connecting section 50 (for example, at Figure 1 and 3 ).

[0098] A restraining portion 52 of the airbag 16 is gathered in the main bag 48, which restraining portion comprises a large part of the airbag volume in the deployed and inflated state and which substantially determines the restraining effect of the airbag 16. This is for example Fig.17 and 19 It can be seen in.

[0099] The neck 54 of the airbag 16 is formed between the blowing end 46 and the restraining portion 52 (see also Fig.19 ) is folded in the connecting section 50. In this example, the length of the neck 54 is approximately 5 to 40 cm, wherein a person skilled in the art can easily adapt the exact length to the actual conditions in the vehicle, such as the length of the firing path and the position of the impact surface of the airbag 16 in the inflated state.

[0100] The neck 54 is oriented along the airbag 16 perpendicular to the longitudinal direction L of the airbag (see, for example, Fig.19 ) or transverse Q perpendicular to the longitudinal direction M of the module G Much narrower than the restriction portion 52. For example, the width of the neck 54 is about 25 to 50% of the maximum width of the restriction portion 52 when the plane is unfolded. Therefore, the filling volume of the neck 54 is much smaller than the filling volume of the restriction portion 52.

[0101] In this embodiment, the neck 54 is not used to assist the restraint effect because it is placed directly on the roof high up in the vehicle. By reducing the volume of the neck 54 due to its reduced width, the material, filling gas and space in the airbag module 12 can be reduced.

[0102] The connecting section 50 and the main package 48 form two sections of the air bag package 14 that are folded independently of one another, as in the example Fig.36 As can be seen in .

[0103] The main package 48 is folded and rolled up, for example, as will be explained in more detail below, while the connecting section 50 is folded only in a zigzag manner with one to three folds in this example. The folds are arranged one behind the other in the longitudinal direction M of the module.

[0104] The gas generator 18 , the connecting section 50 and the main package 48 are arranged in a straight line one after another along the longitudinal direction M of the module.

[0105] With this arrangement, the filling gas from the gas generator 18 first reaches the neck 54 gathered in the connecting section 50. Due to the simple zigzag folding, the folds are filled one after another, which causes the connecting section 50 to stretch and thus exert a force acting in the module longitudinal direction M on the still folded main package 48.

[0106] This results in the main package 48 pushing the roof trim 24 aside and moving it into the vehicle cabin, still essentially folded. Fig.11 This situation is schematically shown in FIG.

[0107] At this point in time, still substantially no gas reaches the main bag 48 , since the gas flow is prevented by the still existing folds of the connecting section 50 .

[0108] Although this folding technology and the pushing of the main package 48 into the vehicle passenger compartment are described here in conjunction with an airbag module 12 fastened to the vehicle roof, according to the invention this technology can also be transferred to airbag modules used at other locations in the vehicle, for example in the knee area or in the seat back.

[0109] The fully inflated airbag 16 has a generally Y- or T-shape in side view (see Fig.17 ), wherein the handle of the Y or T is formed by the blowing end 46 and the neck 54. The restraining portion 52 includes a first free end 56 and a second free end 58. This can be done for the inflated airbag 16. Fig.17 As can be seen in the figure, for an uninflated, flat-expanded airbag 16, for example, in the side cross-sectional view showing the uninflated airbag 16 Fig.18 , wherein the stack, which is normally stacked flat on top of each other, is shown slightly pulled apart for reasons of clarity.

[0110] In the fully inflated state, the second free end 58 is located in the transition between the windshield 26 and the instrument panel 60 of the vehicle, while the first free end 56 extends in the direction of the vehicle occupant and generally forms the lower end of the airbag 16 and of the impact surface 62 for receiving the vehicle occupant.

[0111] The airbag 16 has essentially three large outer wall sections 64, 66, 68 (see Fig.18 ). The first outer wall section 64 extends from the blowing end 46 to the second free end 58 and, in the inflated state, forms a support surface for the airbag 16 on the windshield 26. The second outer wall section 66 extends from the second free end 58 to the first free end 56 and, in the inflated state, is located above the instrument panel 60. The third outer wall section 68 extends from the first free end 56 to the blowing end 46 and, in the inflated state of the airbag 16, forms a collision surface 62 for a vehicle occupant.

[0112] The neck 54 merges into the restraining part 52 in a third outer wall section 68 at a shoulder 69, which is beveled on both sides, so that a continuous transition is formed from the neck 54 to the impact surface 62 (see Fig.19 ).

[0113] However, in the gathered main package 48, the first free end 56 is folded back in the direction of the blowing end 46, so that the sections 70, 72 of the third outer wall section 68 are folded back on themselves. Here, the free end 56 is initially connected to the blowing end 46 by the limiting band 74. This Fig.12 , 13 and 18 are shown in detail.

[0114] In this example, the limiting strap 74 is not fixed directly to the first free end 56, but is fixed offset by about 5 to 20 cm to the second outer wall section 66. As will be explained below, this makes it possible to fold the airbag package 14 more compactly.

[0115] This and the folding of the main bag 48, which will be described in detail below, has the effect that at the point in time when the main bag 48 reaches the vehicle cabin, the first free end 56 is still restrained in the roof region by the restraining strap 47. The remainder of the main bag 48 is then further unfolded in the vehicle cabin, wherein the filling gas flowing into the airbag 16 initially inflates only a partial region of the airbag 16.

[0116] exist Fig.14 and 18 It can be seen in FIG. 1 that at the point in time when the first free end 56 is still connected to the blowing end 46 via the limiting strap 74 , the airbag 16 has approximately a U-shape with an inner edge 76 and an outer edge 78 .

[0117] The inner edge 76 of the U is bounded toward the windshield 26 by the first outer wall section 64 of the airbag 16. The inner edge 76 is bounded toward the passenger compartment by the upper section 70 of the third outer wall section 68.

[0118] The outer edge 78 is bounded toward the instrument panel 60 by the second outer wall section 66 . The outer edge 78 is bounded toward the vehicle passenger compartment by the lower section 72 of the third outer wall section 68 .

[0119] The two sections 70, 72 of the third outer wall section 68 are initially held together by the limiting strip 74. In this way, the filling gas flows only into the inner edge 76, while the outer edge 78 remains essentially unfilled, even though the airbag package 14 has been largely deployed. Figures 12 to 15 This situation is shown in .

[0120] When a certain tensile force occurring with the preset filling volume of the airbag 16 is exceeded, the limiting band 74 is released after a first period of time after the gas generator 18 is activated. In this example, a weakened area 80 is formed on the surface of the limiting band 74 for this purpose (see Fig.18 ).

[0121] In this example, the neck 54 is already fully inflated at the point in time when the restraining strap 74 is released (see Fig.16 ).

[0122] In a second period subsequent to the first period, after the limiting strap 74 is broken into two parts at the weakened area 80, the air bag 16 is fully inflated. Fig.17 The fully inflated state is shown.

[0123] In the fully inflated state, the airbag 16 has a roughly Y- or T-shape when viewed from the side, since the inner edge 78 has been folded downward in the vehicle passenger compartment. The arms of the Y are formed by two inflated sections of the restraining part 52, which extend from the first and second free ends 56, 58 in the direction of the blowing end 46 and which merge into the neck 54.

[0124] Furthermore, a recess 82 is formed in the third outer wall section 68, which is rolled inwards in the folded state (see Fig.18 ), which partially bulges outward in the fully inflated airbag 16 and thereby enlarges the collision surface 62. However, the lower end of the cavity 82 is permanently connected to the second free end 58 via an internal limiting band 84 so that the shape of the inflated airbag 16 is stable.

[0125] As in Figures 20 to 23 As shown in , the gas generator 18 is preferably fixed on the blowing end 46 in the airbag 16 before the airbag 16 is gathered. However, if necessary, this step can also be performed after the airbag 16 is gathered.

[0126] The airbag 16 ends at the blowing end 46 with two opposite lugs 86, each extending over the entire width of the neck 54. Each of the lugs 86 has two fastening openings 88 and a positioning opening 90, which correspond in their arrangement to the fastening bolts 34 and positioning bolts 42 on the gas generator 18 (see, for example, Fig. 20 ).

[0127] Inside the airbag 16 , the two lugs 86 can each be reinforced with one or more reinforcing layers, which can optionally also have a heat-resistant and gas-tight coating.

[0128] To assemble the gas generator 18, place the gas generator between the two lugs 86 ( Fig.21 ), and then the two lugs 86 are placed individually on the gas generator 18, wherein the fastening opening 88 is correspondingly placed on the fastening bolt 34 and the positioning opening 90 is placed on the positioning bolt 42 ( Fig. 22 and 23 ).

[0129] Due to the wrapping of the two lugs 86 and the coating provided, if necessary, on the inner sides of the lugs 86 , the inflator-side blowing end 46 of the airbag 16 is now closed sufficiently gas-tightly.

[0130] The lug 86 is now also fixed to the fastening bolt 34 by means of a clamping washer and / or a nut (not shown).

[0131] In order to gather the airbags 16 into the airbag package 14, first, as in Fig.24 The airbag 16 is unfolded flat as shown in FIG. 1 , wherein the first end 56 is folded back toward the blowing end 46 .

[0132] The two legs 76, 78 of the airbag 16 lie one above the other in the region of the first free end 56. The third outer wall section 68 is folded back on itself in the sections 70, 72.

[0133] On the other hand, the first outer wall section 64 and the second outer wall section 66 each extend from the second free end 58 to the blowing end 46 .

[0134] The limiting band 74 is arranged in such a way that its free end lies on the blowing end 46 .

[0135] In a first folding step, the first free end 56 is now rolled over once about a folding line 92 perpendicular to the airbag longitudinal direction L (which in the flat unfolded airbag 16 coincides with the module longitudinal direction M), but not onto an attachment point 94 of the limiting strap 74 on the second outer section 66 (see Fig.24 and 25 ). Depending on the shape of the airbag, this folding step can also be omitted.

[0136] Now, in a second folding step, the two side regions of the airbag 16 are folded inwardly in a zigzag fold along folding lines 96, 98 extending parallel to the longitudinal direction L of the airbag. Fig.25 and 26 The two fold lines 98 are now along the transverse direction Q G The airbag 16 is delimited laterally outwardly.

[0137] The spacing of the folding lines 96, 98 from one another and from the peripheral edge of the airbag 16 is selected such that no overlapping of the side regions of the airbag 16 occurs in the center of the airbag, wherein the center of the airbag 16 is defined by an imaginary center straight line G which extends from the blowing end 46 to the second free end 58 and is arranged symmetrically with respect to the blowing end 46.

[0138] The airbag 16 can be symmetrical in the deployed state with respect to this center straight line G, but this is not absolutely necessary but is determined primarily by the geometry of the passenger compartment, the windshield 26 and the instrument panel 60 .

[0139] In the winding step, the second free end 58 is now wound. Fig.26 The airbag 16 shown, which is already partially folded, is wound, for example, three to ten turns, in particular six turns, in the direction of the blowing end 46. Fig. 27The result of this folding step is shown in FIG. The rolled-up area now forms the main package 48. Here, the airbag 16 is rolled up only to the end of the restraining portion 52 of the airbag 16. This folding step does not involve extending in the direction of the blowing end 46 (see FIG. Fig.26 and 27 ) of the neck 54 and the area of ​​the limiting band 74.

[0140] In a further folding step, the area of ​​the neck 54 and, if appropriate, the limiting strap 74 protruding from the main package 48 is now folded in a simple zigzag folding manner, for example, with one to three folds, wherein the folding line 100 is oriented perpendicularly to the module direction M and thus parallel to the longitudinal axis (not shown here) of the gas generator 18. The assembled airbag package 14 now has Fig. 27 and 36 The shape shown in .

[0141] The same hole structure 88, 90 as on the lug 86 of the airbag 16 is also realized on the free end of the limiting belt 74, and the limiting belt 74 is also put on the fastening bolt 34 and the positioning bolt 42 by means of the fastening opening 88 and the positioning opening 90 (see also Fig.36 ). The two lugs 86 and the limiting band 74 are now stacked in three layers, wherein the fastening bolts 34 of the gas generator 18 are passed through all three aligned fastening openings 88 . The same applies to the positioning openings 90 .

[0142] In the installed state, the airbag 16 is connected to the module carrier 22 in a load-bearing manner via the fastening screws 34 . The tensile forces acting on the limiting straps 74 are also transmitted to the module carrier 22 via the fastening screws 34 .

[0143] After the gas generator 18 is placed and the airbag 16 is gathered, the airbag package 14 has Fig.28 in the form shown.

[0144] After the gas generator 18 has been fixed in the airbag 16 and the airbag 16 has been assembled to form the airbag package 14 , the airbag package 14 together with the gas generator 18 is inserted into the covering 20 .

[0145] Figures 29 to 35 The covering 20 is shown in detail.

[0146] In this example, the cover 20 is composed completely (except for any seams, of course) of the airbag fabric and is assembled from precisely two blanks 102, 103 (see Fig.30 ).

[0147] The packaging 20 has a receiving pocket 104 (see Fig.31), which is formed by two overlapping sections of the first blank 102 and is used to accommodate the main package 48 of the air bag package 14. The bottom 106 of the receiving bag 104 is provided with a weakened area 108 (see, for example Fig.30 ) and extends along a direction B perpendicular to the module direction M.

[0148] The two edges 110 of the receiving pocket 104 facing away from the bottom 106 (see Fig.31 ) are integrally and seamlessly turned into a retaining lug 112. The two retaining lugs 112 form a gas generator fixing device 114 for fixing the gas generator 18 in the sheath 20 and have an opening pattern at their free ends, which corresponds to the arrangement of the fastening bolts 34 and the positioning bolts 42. Two fastening openings 88 and a positioning opening 90 are correspondingly arranged on the free edge of each retaining lug 112.

[0149] The receiving pocket 104 and the retaining lug 112 are realized together in the first blank 102 by folding the first blank 102 back on itself and partially connecting the longitudinal edges connected to the folding line to form the receiving pocket 104. The free section that protrudes outwards beyond the receiving pocket 104 then forms the retaining lug 112 (see, for example, Fig.30 and 31 ).

[0150] One of the retaining lugs 112, namely Fig.31 The lower center, flat, open retaining lug 112 is separated from the surrounding rest of the first blank 102 by a U-shaped cutting line 116. The cutting line 116 produces a stirrup 118, which has two strap sections 120 located on the sides of the retaining lug 112 and a connecting bridge 122 connecting the two strap sections 120. The strap section 120 is integrally transferred into the receiving pocket 104 at its end opposite the bridge 122.

[0151] The stirrup 118 is part of an airbag package fastening device 124. This airbag package fastening device also has at least one pair of first and second fastening elements 126, 128, which can be plugged together and thus fixed against each other. Here, two pairs of fastening elements 126, 128 are provided, which are arranged side by side parallel to the direction B of the base 106. The exact position and number of the fastening elements and their design are of course determined by the judgment of the skilled person.

[0152] In this example, the first fixing element 126 is configured on the second blank 103, which extends above the receiving pocket 104 parallel to the direction B of the bottom. The first fixing element 126 has the form of an arrow-shaped hook in this example (see in particular Fig.30 and 35 ), these hooks are formed on the edge of the second blank 103 pointing to the bottom 106.

[0153] Two second fixing elements 128 are formed in the bridge 122 and are each formed by an elongated opening through which the hook of the first fixing element 126 can be inserted by hooking its edge around the edge of the opening and fixing the first fixing element 126 on the bridge 122 . Fig.35 A detailed view of the fixing elements 126 , 128 is shown.

[0154] In this embodiment, the second blank 103 is made of a multi-layer airbag fabric, while the first blank 102 is cut from a single-layer airbag fabric. The cutting is performed by laser cutting, so that the edges of the multi-layers are welded directly to one another in the second blank 103 without having to fix the edges that are in contact with one another separately. Since the first fixing elements 126 are thus also made of a multi-layer airbag fabric, they have sufficient rigidity to be hooked into the openings of the second fixing elements 128.

[0155] The second blank 103 extends beyond the receiving pocket 104 laterally, ie parallel to the bottom direction B. A fastening section 130 is formed at each of its free ends, which serves to secure the covering 20 in a fixed manner relative to the vehicle. This fastening does not have to bear the entire load of the deployed airbag 16, but rather serves primarily to position the airbag module 12 on the roof frame 23.

[0156] However, the fastening sections 130 are also used here to pre-fasten the airbag module 10 in the vehicle. For this purpose, each of the fastening sections 130 has, in addition to a fastening opening 132, through which, for example, a screw for fixed fastening relative to the vehicle is inserted, a further pre-fastening opening 134, into which a fastening clip 136 is inserted (see Fig.34 When the airbag module 10 is mounted on the vehicle, the fastening clips 136 are pushed into openings on the roof frame 23 or on the module carrier 22 and the airbag module 10 is held in position until final fastening has been achieved.

[0157] The fastening openings 132 and the pre-fastening openings 134 are arranged in the two fastening sections 130 one above the other parallel to the module longitudinal direction M, but in a different sequence (see for example Fig.30 ).

[0158] In order to insert the airbag package 14 into the package cover 20, the main package 48 is first pushed into the receiving pocket 104 (see Fig.31 and 32). The two retaining lugs 112 are then placed once with the fastening opening 88 and the positioning opening 90 onto the fastening bolts 34 and the positioning bolts 42 of the gas generator 18 so that they grip the gas generator 18 and of course the blowing end 46 of the airbag 16 on the back side of the gas generator 18 (see 32 and 33 as well as 37 and 38).

[0159] The two retaining lugs 112 can have different lengths l1, l2 along the module longitudinal direction M, as for example in Fig.37 As shown in . In this way, the tensile force acting on the fastening bolt 34 of the gas generator 18 via the retaining lug 112 can be adjusted to a certain extent. This has the result that the orientation of the gas generator 18 with respect to the rotation about its longitudinal axis can be determined by selecting the length of the retaining lug 112. Normally, it is desired that the fastening bolt 34 extends exactly in the module longitudinal direction M. However, it can also be beneficial, for example to simplify the assembly on the roof frame, if the bolt 34 is tilted a few degrees relative to the module longitudinal direction M. Since the gas generator 18 usually has a planar gas outlet area (not shown), a tilting of a few degrees does not affect the gas outflow and the inflation performance of the airbag 16.

[0160] After the gas generator fixture 114 is closed as described (in Fig.33 ), the stirrup 118 is now placed on the retaining lug 112. In the next step, the bridge 122 is pushed under the second blank 103 and the hook of the first fixing element 126 is passed through the opening of the second fixing element 128 (see Fig.34 ). The belt section 120 is now located above the main package 48 of the air bag package 14 on the side of the retaining lugs 112 and securely holds this main package in the receiving pocket 104. The air bag package fastening device 124 is thus closed.

[0161] The airbag package 14 including the covering 20 can now be inserted into the module carrier 22 in order to install the airbag module 10 on the vehicle.

[0162] When the airbag module 10 is activated, the weakened area 108 on the bottom 106 of the receiving pocket 104 opens so that the airbag package 14 can come out. The gas generator fastening 114 , the airbag package fastening 124 and the fastening to the vehicle via the fastening section 130 remain closed.

[0163] In order to better fix the zigzag folds of the neck 54 in the connecting section 50 during the insertion of the airbag package 14 into the covering 20, an intermediate covering 140 can be used in an alternative method, such as Figures 39 to 44 As described.

[0164] The intermediate jacket 140 is a substantially rectangular airbag fabric having a hole pattern corresponding to the fastening bolts 34 and the positioning bolts 42 of the gas generator 18 at both free ends, the hole pattern including two fastening openings 88 and one positioning opening 90 (see Fig.39 ).

[0165] First, the assembled airbag package 14 including the gas generator 18 is enclosed in the intermediate package 140, wherein the two ends of the intermediate package 140 are placed on the bolts 34 and 42 of the gas generator 18. Fig.40 , it is shown that a known folding device 136 is used.

[0166] The airbag package 14 , which is securely surrounded by the intermediate package 140 , is now inserted into the package 20 , wherein the main package 48 is pushed into the receiving pocket 104 (see Fig.41 ).

[0167] The intermediate casing 140 is now opened again by removing its two ends from the bolts 34, 42 of the gas generator 18. Fig.42 Shown in.

[0168] Now, one of the two retaining lugs 112 of the sheath 20 is placed onto the bolts 34, 42 of the gas generator 18 in order to fix the sheath 20 to the gas generator 18. Fig.43 As shown in , the intermediate covering 140 can be pulled out from between the airbag package 14 and the covering 20. In this case, in particular, the folding of the connecting section 50 can no longer be changed, because the one holding lug 112 already connected to the gas generator 18 holds the airbag package 14 in its desired shape.

[0169] After the intermediate casing 140 has been removed, the second retaining lugs 112 are also closed by sliding their openings over the bolts 34 , 42 of the gas generator 18 .

[0170] Finally, the airbag package fastening device 124 is also closed by sliding the stirrup 118 onto the gas generator 18 and the retaining lugs 112 surrounding the gas generator as described above, pushing the bridge 122 under the second blank 103 and closing the fastening elements 126 , 128 .

Claims

1. A casing for an airbag (16) of a vehicle occupant restraint system (10), the casing being flexible and having a receiving cavity formed by a receiving pocket (104) for a gathered airbag package (14), the casing having an airbag package fastening device (124), a gas generator fastening device (114) formed by a protruding retaining lug (112) and at least one fastening section (130) for fastening the airbag module (12) to the vehicle, in, The packaging (20) comprises two interconnected blanks (102, 103), the second blank (102) extending on the first blank (103) folded once and forming a receiving pocket (104) parallel to the longitudinal extension (B) of the bottom (106) of the receiving pocket (104), and the at least one first fixing element (126) is formed in the second blank (103) and the at least one second fixing element (128) is formed in the first blank (102), The airbag package fixing device (124) has at least one pair of first fixing elements (126) and second fixing elements (128) connected in an alternating manner, which fixing elements are designed as a plug-in connection in the form of a hook and loop, the airbag package fixing device (124) comprises at least one belt section (120) which is held in position by means of the fixing elements (126, 128) and which fixes the airbag package (14) in the receiving pocket (104), Each retaining lug (112) of the gas generator fastening device (114) has at least one fastening opening (88) for a fastening bolt (34) of the gas generator.

2. The package according to claim 1, characterized in that: The cover (20) is made entirely of airbag fabric.

3. The package according to claim 1 or 2, characterized in that: The retaining lug (112) is integrated into the receiving pocket (104) at an edge opposite the bottom (106) of the receiving pocket (104).

4. The package according to claim 1, characterized in that: The belt section (120) extends outside through an opening of the receiving pocket (104).

5. The package according to claim 1, characterized in that: The belt section (120) is integrally pivoted into the receiving pocket (104) at an edge of the receiving pocket (104) opposite the bottom (106).

6. The package according to claim 1, characterized in that: Two strap sections (120) are provided which are part of a U-shaped stirrup (118) which is produced by a U-shaped cutting line (116) which separates the stirrup (118) from one of the retaining lugs (112).

7. The package according to claim 1, characterized in that: The fastening section (130) is part of the second blank (103) and a fastening section (130) is formed on both sides of the sheath (20), the fastening section having at least one fastening opening (132) and a pre-fastening opening (134).

8. The package according to claim 1 or 2, characterized in that: The covering (20) is partially composed of a plurality of layers of airbag fabric, and the edges of the respective sections are produced by laser cutting, wherein the plurality of layers are welded to one another at the edges.

9. The package according to claim 1 or 2, characterized in that: The bottom (106) of the receiving bag (104) has a weakened area (108) which is broken when the airbag (16) is deployed, so that the airbag (16) can come out of the packaging (20).

10. The package according to claim 1, characterized in that: The two retaining lugs (112) have different lengths (l1, l2) when viewed from the bottom (106) of the receiving pocket (104).

11. The package according to claim 1 or 2, characterized in that: When the airbag (16) is deployed, the airbag package fastening device (124) and the gas generator fastening device (114) remain closed and the fastening section (130) remains fixed to the vehicle.

12. Method for packaging an airbag (16) in a packaging (20) according to any one of the preceding claims, the method comprising the following steps: - preparing an airbag (16) assembled into an airbag package (14), the airbag containing a gas generator (18) and an intermediate casing (140), the intermediate casing consisting of a connected fabric piece, the length of which corresponds to the total circumference of the airbag package (14) and which has openings (88, 90) at both longitudinal ends for fastening to the gas generator (18), - encapsulating the airbag package (14) and the gas generator (18) together in an intermediate jacket (140), so that the intermediate jacket (140) surrounds the airbag package (14) and the gas generator (18) along the longitudinal direction (M) of the module and fastens the two longitudinal ends to the gas generator (18), - pushing the assembly consisting of the intermediate casing (140), the airbag package (14) and the gas generator (18) into the casing (20) so that the airbag package (14) is partially located with the main package (48) in the receiving pocket (104) of the casing (20), - opening the intermediate casing (140) by detaching the two longitudinal ends of the intermediate casing (140) from the gas generator (18), - fastening one of the retaining lugs (112) of the gas generator fastening device (114) of the sheath (20) to the gas generator (18), - pulling the intermediate sheath (140) out between the airbag sheath (14) and the sheath (20), and - Fastening the second retaining lug (112) of the encapsulation (20) to the gas generator (18).

13. The method according to claim 12, comprising the further step of closing the air bag package securing device (124).

14. The method according to claim 12, wherein: The fabric piece is rectangular.

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