Support structure for an airbag

Abstract

Support structure for a motor vehicle airbag, which can be moved from a storage position to a retention position by means of a gas flow and a plurality of interconnected hollow bodies (36) forming a channel system (34), through which an outer structure (80) of the supporting structure (32) is formed in a truss-like or scaffold-like form, so that in the containment position ambient air in the containment volume (44) enclosed by the support structure (32) can be used for a containment effect, characterized by the fact that within the canal system (34) means (52, 60, 68, 70, 72) are provided for the targeted influencing of the gas flow.

Description

[0001] The invention relates to a support structure for an airbag of the type specified in the preamble of claim 1.

[0002] Airbags are a well-known feature in the mass production of motor vehicles, particularly passenger cars. Initially used primarily to protect the driver and front passenger, they have also been widely used in recent years as side airbags in the side doors, as head airbags in the side windows, or in other locations within the vehicle.

[0003] A key objective in airbag development is to position the airbag as large and optimally as possible in its restraint position to ensure optimal restraint. Additionally, favorable out-of-position (OoP) behavior of the airbag aims to ensure that, even in poor or unusual seating positions, vehicle occupants are effectively restrained in the event of a collision, without experiencing unnecessary stress from the airbag itself. Furthermore, favorable low-risk deployment (LRD) behavior aims to achieve an airbag deployment into the restraint position that minimizes impact on the occupant.

[0004] DE 198 22 227 A1, US 3 960 386 A, EP 1 477 372 A1, US 2001 / 0 003 395 A1, US 2006 / 0 197 320 A1 and US 4 500 114 A each disclose, considered separately, a support structure for an airbag which can be moved from a storage position to a restraint position by means of a gas flow and which comprises a plurality of interconnected hollow bodies forming a channel system, wherein means for targeted control of the gas flow are provided within the channel system.

[0005] The object of the present invention is therefore to create a support structure for an airbag of the type mentioned above, by means of which the protective properties of the airbag can be further improved.

[0006] This problem is solved according to the invention by a support structure with the features of claim 1. Advantageous embodiments with expedient and non-trivial further developments of the invention are specified in the remaining claims.

[0007] To create an airbag with particularly favorable protective properties, the invention provides a support structure which can be moved or enlarged from a storage position to a holding position by means of a gas flow and comprises a plurality of interconnected hollow bodies forming a channel system. These hollow bodies form an outer structure of the support structure in a truss-like or scaffold-like form, so that in the holding position, ambient air in the holding volume enclosed by the support structure can be used for a holding effect. Means for selectively influencing the gas flow are provided within the channel system. In other words, for example, a truss-like or scaffold-like support structure is provided in the holding position, consisting of a plurality of hollow bodies—for example, tubular bodies—connected to each other to form a gas-carrying channel system.To specifically improve the airbag's protective function, the duct system incorporates means for precisely influencing the gas flow. These means allow for targeted adjustments to aspects such as the filling time, filling sequence, deployment behavior, out-of-probability (OOP) behavior, and low-pressure discharge (LDD) behavior of the support structure or the airbag itself. It is evident that all these measures contribute to enhancing the airbag's protective function.

[0008] By selectively controlling the gas flow, it is possible, for example, to supply individual sections of the support structure with different gas flow rates or pressures at different times. This makes it possible to achieve specific movement or deployment patterns of the support structure or airbag. Similarly, the restraining effect of the support structure can be influenced by selectively controlling the gas flow and creating pressure differences.

[0009] The support structure itself is preferably surrounded by a casing or similar structure, so that the ambient air enclosed within the support structure can be used for the restraint effect. This occurs, for example, when the occupant impacts the airbag in its restraint position, the internal pressure builds up within the casing of the support structure, thus creating the restraint effect. Therefore, it is particularly important that the pressure build-up within the volume enclosed by the support structure is as efficient as possible.

[0010] In a further embodiment of the invention, it has also proven advantageous to arrange at least one guiding element within the channel system, by means of which the gas flow is directed. Thus, when the airbag is deployed or moved into the restraint position, it is easily possible, for example, to divide the gas flow between individual hollow bodies or sections of the channel system. Depending on how far, for example, the guiding surface projects into a corresponding hollow body, a volume flow can be determined, which should flow in one direction or the other. Overall, this provides a simple means of selectively influencing the gas flow.

[0011] In a further development of the invention, at least one guiding element is preferably provided in the area of ​​a connection point between two hollow bodies of the channel system in order to indirectly divide the gas flows on site between two partial flows which are to be directed to the respective hollow bodies.

[0012] In a further advantageous embodiment, at least one closure element is arranged within the channel system, by means of which an associated hollow body can be closed. This allows the flow through a corresponding hollow body or a section of the support structure to be selectively prevented or stopped, and this closure simultaneously allows the gas flow to be redirected to another section of the support structure. It is clear that this allows, in particular, the sequence or deployment behavior of the support structure or the airbag to be specifically influenced. This makes it possible to stop or redirect the gas flow to influence the inflation sequence.

[0013] In a further embodiment of the invention, at least one cross-sectional change of an associated hollow body within the channel system is provided. This cross-sectional change can be extremely localized or partial, or it can occur over longer sections of the hollow body. This measure allows the flow resistance within the respective hollow body or the respective section of the support structure to be adjusted accordingly for the appropriate distribution of the gas flow. In other words, the flow behavior of the gas flow can be influenced by the targeted cross-sectional change, for example, to create a specific filling sequence or a specific expansion behavior.The targeted change in the cross-sectional area of ​​the associated hollow body can also be used to influence the flow and / or pressure conditions in the hollow bodies, for example to deliberately create or avoid constrictions that can be caused by the Bernoulli effect.

[0014] It has also proven advantageous to arrange at least one valve within the channel system to control the gas flow. A diaphragm functioning in the same way could, of course, be used instead of a valve. Such a valve makes it possible to set different pressures in individual sections of the hollow body or subsections of the channel system. This allows, for example, a portion of the gas filling or gas flow to be used for filling and heating the containment volume, while another portion remains in the support structure or channel system to achieve a containment effect or to restore the containment volume. The unfolding sequence and speed can be controlled accordingly using a labyrinth and / or obstacle structure created in this way.In a further embodiment of the invention, at least one valve can also be designed as a check valve.

[0015] It is also provided that at least one closure element is arranged within the channel system, by means of which an associated hollow body can be closed. In particular, it would be conceivable to use a flap or the like instead of a valve, by means of which a gas flow can pass through the hollow body in one direction but not in the other.

[0016] Finally, in a further development of the invention, it has proven advantageous if at least one hollow body of the channel system has a predetermined bending point. This also favorably influences the out-of-probation (OOP) and left-behind-the-valve (LRD) behavior of the airbag.

[0017] In a further development of the invention, it has proven advantageous to provide at least one hollow body by means of which hollow bodies of the outer structure are connected to one another, wherein this hollow body extends through the containment volume in the retracted position and is not merely arranged on the surface of the support structure. Accordingly, at least one hollow body is provided which extends not only along the outer surface of the support structure but also through its containment volume. This allows corresponding sections of the outer structure of the support structure to be connected to one another in a suitable manner in order to optimize the deployment and, if applicable, also the load-bearing behavior of the support structure or the airbag. Thus, a shortcut can be created by means of the hollow body extending through the containment volume, thereby optimizing the deployment and load-bearing behavior of the support structure or the airbag.Furthermore, at least one hollow body which passes through the retention volume can be used to support or stiffen the support structure or the airbag.

[0018] Finally, it has proven advantageous to connect a gas generator producing the gas flow with a plurality of hollow bodies in order to achieve a rapid distribution of the medium within the channel system.

[0019] Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawings; these show in: Fig. 1 a partial and cropped side view of a passenger compartment of a passenger car with a passenger positioned on a front passenger seat, who has been moved forward in the longitudinal direction of the vehicle as a result of a collision of the passenger car and is restrained by a passenger airbag which has been moved from a storage position within an instrument panel of the passenger car into a restraint position, wherein the airbag comprises a support structure which includes a plurality of interconnected hollow bodies forming a channel system, and wherein the support structure has been moved from the storage position into the restraint position by means of a gas flow from a gas generator; Fig. 2 a perspective view of the support structure for the airbag according to Fig. 1, which is shown here in its unfolded or enlarged restraint position and comprises a plurality of interconnected hollow bodies forming the channel system, which are arranged in a truss-like manner, wherein the individual compartments of the truss are closed by respective surface elements of a covering which encloses the restraint volume of the airbag enclosed by the support structure; Fig. 3 a perspective section view through the support structure and the airbag according to Fig. 2 along a cutting plane running in the longitudinal direction of the vehicle or in the vertical direction of the vehicle; Fig. 4 a perspective view of the support structure for the airbag according to Fig. 2, in contrast to this, the surface elements of the airbag's containment volume that fill the compartments of the support structure are omitted; Fig. 5 a schematic sectional view of a connection point of two hollow bodies of the channel system of the support structure, wherein a guiding element is provided in the area of ​​a connection point of the two hollow bodies, by means of which a gas flow can be controlled in a targeted manner; Fig. 6 another schematic sectional view through the channel system of the support structure, wherein a closure element is provided within a hollow body by means of which the hollow body can be closed or is closed; Fig. 7 a schematic and partial cross-sectional view through the channel system of the support structure, in which a branching between two hollow bodies is recognizable, one of which has a change in cross-section in the form of a reduction in cross-section, thereby allowing a targeted influence on the gas flow flowing into the two hollow bodies; Fig. 8 another schematic and partial sectional view through the channel system of the support structure analogous to Fig. 7, where in this case the change in cross-section is only provided at a single point in the area of ​​one of the two hollow bodies; Fig. 9 a schematic and partial sectional view of a hollow body of the support structure with a valve designed as a check valve, by means of which a flow direction of the gas flow can be set; and in Fig. 10 Another partial sectional view of a hollow body of the channel system of the support structure with a differently designed check valve.

[0020] In Fig. Figure 1 shows a partial and schematic side view of the passenger compartment 8 of a passenger car. In particular, an A-pillar 10 is visible, which transitions into a roof frame 12 at the top. Furthermore, a B-pillar 14, two seat cross members 16 extending between an unseen central tunnel and a side sill (also unseen), and a partial view of a front bulkhead 18, which defines the front boundary of the passenger compartment 8, are visible in the unfinished structure.

[0021] A section of the interior of the passenger car shows a front passenger seat 20, on which a passenger 22 is positioned. The passenger 22 is secured by a seat belt 24.

[0022] Furthermore, a section of an instrument panel 26 is visible, from which a passenger airbag 28, which will be shown in more detail below, has been moved or enlarged from a storage position in which it is arranged in an airbag module 30 within the instrument panel 26 to a holding position shown here. Consequently, in Fig. Figure 1 shows an accident scenario in which the seat occupant 22 has already been moved forward from the vehicle seat 20 and is already partially restrained by the airbag 28, which has already been deployed or enlarged from the storage position to the restraint position by means of appropriate sensors.

[0023] In conjunction with Fig. Figure 2, which shows the airbag 28 in its fully deployed restraint position, shows that it comprises a support structure 32, which is formed by a plurality of interconnected hollow bodies 36 forming a channel system 34. The hollow bodies 36 are designed as tube-like structures connected to each other to form a truss-like or scaffold-like channel system 34. In this case, the hollow bodies 36 consist of a flexible, gas-fillable hose material.

[0024] The interconnected hollow bodies 36, arranged in a truss-like manner, thus create individual compartments 38 of the support structure 32, which are filled by surface elements 40. These surface elements 40 consist of a flexible material, for example, a fabric or rubber material. Together, the surface elements 40 form an enclosure 42, which encloses a retention volume 44 enclosed by the support structure 32.

[0025] This is particularly evident when viewed in conjunction with Fig. Figure 3 shows the airbag 28 with the support structure 32 and the casing 42 in a perspective sectional view along a section plane extending in the longitudinal and vertical directions of the vehicle. In particular, it is evident that the hollow bodies 36 are designed as tube or hose elements, which together form the channel system 34.

[0026] A number of the hollow bodies 36 are connected to a gas generator 46, which, in the event of a collision of the vehicle, can generate a gas flow that flows into the channel system 34 of the support structure 32. This moves the support structure 32, or the airbag 28 as a whole, out of the airbag module 30 or the instrument panel 26 from its storage position into its deployment position, thus expanding it. In other words, the individual hollow bodies 36 of the channel system 34 are inflated or unfolded by the gas flow. Simultaneously with this expansion or unfolding of the support structure 32, the surface elements 40 of the airbag 28's casing 42 are also unfolded to fill the corresponding compartments 38 and to externally limit the airbag 28's containment volume 44.

[0027] By activating the gas generator 46, a gas flow is generated, which inflates the support structure 32. Simultaneously, the containment volume 44, limited by the support structure 32 or the casing 42, is expanded. In one embodiment, this volume is filled with ambient air at ambient pressure. This can be achieved, for example, by providing corresponding openings 48 within the casing 42 or the surface elements 40. The internal pressure of the casing 42 is generally lower than that of conventional airbags. However, this internal pressure increases for containment purposes when the seat occupant 22 – as in Fig. Figure 1 shows the airbag being moved forward into the airbag 28. The resulting volume reduction increases the internal pressure within the containment volume 44, thereby restraining the seat occupant 22. It is particularly important that this pressure build-up for restraint is as efficient as possible.

[0028] It is to be considered as included within the scope of the invention that gas from the gas generator 46 could optionally also flow into the retention volume 44 or the covering 42 in order to increase the internal pressure of the airbag 28.

[0029] In order to achieve a particularly favorable positioning and a particularly favorable OoP behavior or an advantageous LRD behavior, means for the targeted influencing or interruption of the gas flow generated by the gas generator 48 in the event of a collision, which will be explained in more detail below, are provided within the channel system 34.

[0030] In Fig. Figure 5 shows a branch point or connection point 50 between two hollow bodies 36, in the area of ​​which a guide element 52 is provided in the form of a correspondingly sloping projecting wall. A further guide element 54 is formed as a corner projecting from the associated wall 53. The guide element 52 ensures that a gas flow, indicated by arrow 55, reaches one of the corresponding hollow bodies 36, while a partial gas flow, indicated by arrow 56, which has been deflected by the guide element 54, bypasses the guide element 52 and enters the other hollow body 36. Thus, the guide elements 52 and 54 enable a targeted division of the partial gas flows, thereby positively influencing the development behavior, the filling sequence, the out-of-probability (OOP) behavior, and the low-pressure discharge (LPD) behavior.

[0031] Fig. Figure 6 shows a further partial and schematic sectional view of corresponding hollow bodies 36 of the channel system 34, wherein a closure element 60 is arranged in the area of ​​a branch 58, which is designed there, for example, as a flap. The special feature in the present embodiment is that the closure element 60 is closed by the gas flow indicated by the arrow 61, which reaches the rear of the closure element 60 via a corresponding loop 62. After the closure element 60 is closed, the gas flow can then continue, for example, into another hollow body 36, which is only indicated by dashed lines. Of course, it would also be conceivable that after the closure element 60 is closed, further flow of the gas flow is no longer possible.With such a closure element 60, it is possible, for example, to stop the gas flow accordingly, so that it can be selectively redirected. By stopping and / or redirecting the gas flow, the filling sequence and the expansion behavior can be specifically influenced.

[0032] In the Fig. 6 and Fig. Figure 7 shows a schematic sectional view of the channel system 34, specifically in the area of ​​a branch 64, where a hollow body 36 divides into two further hollow bodies 36, or where the gas flow is divided according to arrows 65, 66.

[0033] The special feature of the embodiments according to the Fig. 7 and Fig. 8 lies in the fact that a cross-sectional change 68, 69 – in the present case a respective reduction in cross-section – is provided within the associated hollow body 36. While in Fig. 7 if this cross-sectional change 68 extends over the further length of the associated hollow body 36, the cross-sectional change 69 is according to Fig. 8 is only formed at specific points or partially in the manner of a throttle. In both cases, however, it is achieved that the flow resistance within the hollow bodies 36 can be adapted to the appropriate distribution of the gas flow (arrows 65, 66). This results in a deliberate division of the gas flow in order to influence the filling time, the filling sequence, and the deployment behavior of the airbag 28. These measures can also be used to influence the flow and / or pressure conditions in the hollow bodies 36, for example, to create or avoid targeted constrictions that can be caused by the Bernoulli effect.

[0034] In the Fig. 9 and Fig. Figure 10 shows a partial sectional view of one of the hollow bodies 36 of the channel system 34, within which means are provided for selectively influencing or interrupting the gas flow. In this case, these means are valves 70 and 72, which function as check valves. If a gas flow therefore occurs in the embodiment according to Fig. If the arrow 9 is turned in the direction indicated by arrow 73, the valve 70 is open. In the opposite direction – according to arrow 74 – the check valve 70 is closed. Fig. Figure 10 shows a similar example of operation, where the valve 72 is shown open above a center line 75 of the hollow body 36 and closed below the center line 75, depending on the direction of the gas flow. Such valves 70, 72, or diaphragms can not only completely close the respective hollow body 36, but also set different pressures within the respective hollow bodies 36 or sections of the support structure 32. For example, it is possible to use part of the gas filling of the gas generator 46 to fill or heat the containment volume 44, while the remaining portion in the support structure 32 or the channel system 34 can be used to retain the contents or to restore the containment volume 44. The unfolding sequence and speed can be controlled by a labyrinth and / or obstacle structure that can be represented in this way.These design types can also be used to create predetermined buckling points in hollow bodies 36, which can favorably influence the OoP behavior and the LRD behavior.

[0035] Based on Fig. 4 It is further evident that the unfolding can also be influenced by means of catch and / or pull bands 78, which extend through the retention volume 44 and connect the respective hollow bodies 36 of the support structure 32 to one another. This makes it possible, for example, to achieve appropriate control of the unfolding sequence and unfolding speed depending on the progress of the unfolding during a re-ignition of a gas generator stage of the gas generator 46.

[0036] Finally, it is particularly evident from Fig.4. It is evident that a plurality of the hollow bodies 36 form an outer structure 80 of the support structure 32, wherein at least one hollow body 82, indicated by dashed lines, is provided, with which the hollow bodies 36 of the outer structure 80 are connected to one another. The hollow body 82, which thus extends through the containment volume 44, makes it possible to connect corresponding sub-areas of the support structure 32 to one another in order to optimize the deployment and, if applicable, also the load-bearing behavior of the airbag 28. In other words, at least one hollow body 82 is provided here, which not only runs along the surface of the support structure 32 but also through the containment volume 44. This shortcut by means of the hollow body 82 may also achieve improved support and mutual stiffening of the hollow bodies 36 or of the support structure as a whole. Through the system of interconnected hollow bodies 36 orWith appropriate design, the tubular structure also forms a distribution network to improve expansion in the presence of obstacles, even if individual hollow bodies 36 are hindered in their filling process, for example, by a local obstruction. In this case, if desired in the design of the support structure, at least parts of the support structure can still be filled via "detours" (unobstructed hollow bodies 36) instead of being completely blocked.

Claims

[1] Support structure for a motor vehicle airbag, which can be moved from a storage position to a retention position by means of a gas flow and a plurality of interconnected hollow bodies (36) forming a channel system (34), through which an outer structure (80) of the supporting structure (32) is formed in a truss-like or scaffold-like form, so that in the containment position ambient air in the containment volume (44) enclosed by the support structure (32) can be used for a containment effect, characterized by , that within the canal system (34) means (52, 60, 68, 70, 72) are provided for the targeted influencing of the gas flow. [2] Support structure according to claim 1, characterized by , that at least one guiding element (52) is arranged within the channel system (34) by means of which the gas flow is to be guided. [3] Support structure according to claim 2, characterized by, that the guiding element (52) is provided in the area of ​​a connection point (50) of two hollow bodies (36) of the channel system (34). [4] Support structure according to any one of the preceding claims, characterized by , that at least one closure element (60) is arranged within the channel system (34) by means of which an associated hollow body (36) can be closed. [5] Support structure according to any one of the preceding claims, characterized by , that at least one cross-sectional change (68, 69) of an associated hollow body (36) is provided in the retention position within the channel system (34). [6] Support structure according to any one of the preceding claims, characterized by , that at least one valve (70, 72) is arranged within the channel system (34) by means of which the gas flow is to be adjusted. [7] Support structure according to claim 6, characterized by, that at least one valve (70, 72) arranged within the channel system (34) is designed as a check valve. [8] Support structure according to any one of the preceding claims, characterized by , that sections of the channel system (34) in the retention position have different gas filling pressures. [9] Support structure according to any one of the preceding claims, characterized by , that at least one hollow body (36) of the channel system (34) has a predetermined bending point. [10] Support structure according to any one of the preceding claims, characterized by , that at least one hollow body (82) is provided, by means of which hollow bodies (36) of the outer structure (80) are connected to each other, wherein this hollow body (82) extends through the retention volume (44) in the retention position and is not only located on the surface of the support structure (32). [11] Support structure according to any one of the preceding claims, characterized by , that a gas generator (46) generating the gas flow is connected to a plurality of hollow bodies (36).

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