Front gasbag module for mounting on or in an instrument panel of a motor vehicle, as well as motor vehicles with such a front gasbag module

Abstract

The invention relates to a front airbag module (18) for mounting on or in an instrument panel (14) of a motor vehicle (10) in the direction of travel in front of a vehicle steering wheel (16), with an inflatable airbag (22) which, when inflated, extends in an arc first rearward and then downward between the occupants (24) and the vehicle steering wheel (16) and has an impact surface (26) facing the occupant (24) and an opposing support surface (28) facing the vehicle steering wheel (16), wherein a retaining strap (30, 32) is provided which has a first retaining strap end (34) attached to the impact surface (26) and an opposite second retaining strap end (36), wherein an activatable retaining strap release device (38) is provided which is connected to the second retaining strap end (36) in a non-activated state and releases the second retaining strap end (36) in an activated state.wherein the airbag (22) assumes a first contour when the retaining strap release device (38) is not activated, in which movement of the impact surface (26) towards the occupant (24) is limited by the retaining strap (30, 32), and assumes a second contour when the retaining strap release device (38) is activated, in which the impact surface (26) can move unhindered by the retaining strap (30, 32) towards the occupant (24). The invention also relates to a motor vehicle (10) with such a front airbag module (18).

Description

[0001] The invention relates to a front gasbag module for mounting on or in an instrument panel of a motor vehicle in the direction of travel in front of a vehicle steering wheel, and to a motor vehicle with such a front gasbag module.

[0002] To improve occupant safety, airbag modules are used as restraint devices in vehicles. So-called front airbags are frequently employed, in which an airbag inflates in front of the vehicle occupant, cushioning the impact, especially the occupant's head, in the event of a crash. A distinction is made between driver-side and passenger-side airbags. Passenger-side airbags are located in the instrument panel and, compared to driver-side airbags, which are located in the steering wheel, have a larger airbag volume. They therefore also have a larger restraint area.

[0003] Furthermore, airbags that deploy from the instrument panel have the advantage that their restraint effect is independent of the steering wheel design. With traditional steering wheels, the largely circular rim provides a large, symmetrical support surface against which a front airbag deploying from the steering wheel hub can be effectively braced in the event of an occupant impact. This support effect for the front airbag is limited with modern steering wheel designs, such as those with an almost rectangular rim or one interrupted at the 12 o'clock position (so-called yoke steering wheels).

[0004] Therefore, there are increasing efforts to also accommodate the driver's side front airbag in the instrument panel, analogous to the passenger side front airbag.

[0005] The arrangement of gasbags in the instrument panel is more difficult for driver's side gasbags than for passenger side gasbags, because the steering wheel, which is positioned in front of the instrument panel and acts as a disruptive contour, can hinder the deployment of the gasbag.

[0006] In addition, the arrangement of the gasbag module in the instrument panel can impair the deployment trajectory of the gasbag, which runs at least partially between the windshield and the instrument panel.

[0007] Finally, with the ongoing development of automated driving functions, the occupant seating position also varies considerably from a traditional, steering-hand-adjustable position in manual driving mode to a more reclined, relaxed comfort position in automated or autonomous driving mode. To ensure optimal restraint for the vehicle occupant in the event of a crash, it would be desirable for the front airbag to have different deployment geometries depending on the occupant's seating position.

[0008] The object of the invention is therefore to provide a gasbag module mounted on or in the instrument panel in the direction of travel in front of a vehicle steering wheel, wherein the front gasbag module unfolds safely between the vehicle steering wheel and the occupant and furthermore has different unfolding geometries depending on an occupant seating position.

[0009] According to the invention, this problem is solved by a front gasbag module for mounting on or in an instrument panel of a motor vehicle in the direction of travel in front of a vehicle steering wheel, with an inflatable gasbag for restraining an occupant positioned behind the vehicle steering wheel in the direction of travel, wherein the gasbag, when inflated, extends in an arc shape, viewed in the direction of travel, first along the windshield to the rear and then downwards between the occupant and the vehicle steering wheel, and has an impact surface facing the occupant and an opposing support surface facing the vehicle steering wheel.Furthermore, the front gasbag module comprises at least one retaining strap, which has a first retaining strap end attached to the impact surface of the gasbag and an opposing second retaining strap end, wherein an activatable retaining strap release device is provided which, in a non-activated state, is connected to the second retaining strap end and, in an activated state, releases the second retaining strap end. With the retaining strap release device non-activated, the gasbag then assumes a first contour in which movement of the impact surface towards the occupant is limited by the at least one retaining strap, and with the retaining strap release device activated, a second contour in which the impact surface can move unhindered towards the occupant by the at least one retaining strap.

[0010] This results in an adaptive front airbag on the driver's side, which provides good restraint regardless of the steering wheel design and whose deployment geometry can be advantageously adapted to the occupant's seating position.

[0011] Preferably, the gasbag module comprises a module housing in which the folded gasbag and a gas generator for filling the gasbag with generator gas are accommodated, with the safety strap release device being attached to or within the module housing. The safety strap release device is, for example, a pyrotechnically or electrically driven actuator that releases the second end of the safety strap upon receiving an electrical signal. The existing module housing of the gasbag module can serve as a stable support to which the safety strap release device is securely and reliably attached. According to another embodiment, the gas generator housed within the module housing forms a stable support, with the safety strap release device then being attached directly to or integrated into the gas generator.

[0012] In particular, multiple retaining straps can be provided, the first ends of which, viewed in the transverse and / or vertical direction of the vehicle, are attached to the impact surface at intervals. In this way, the contour of the impact surface can be easily modified to achieve ideal occupant restraint. Specifically, the retaining straps can be very short, so that when the retaining strap release mechanism is not activated, the impact surface is fragmented by deep airbag pockets. This reduces the surface tension on the impact surface and allows it to be structured with minimal effort, resulting in particularly effective occupant restraint.

[0013] Preferably, at least three retaining straps are provided, wherein the two outermost retaining straps, viewed in the transverse direction of the vehicle, are longer than the at least one intermediate retaining strap. This results in lateral bulges from the occupant's perspective, which lead to particularly good occupant restraint, especially when the occupant's seating position deviates from the ideal position.

[0014] In one embodiment of the front gasbag module, at least the second ends of the outer two retaining straps are coupled to a module housing of the front gasbag module, while the second end of the retaining strap of the at least one intermediate retaining strap is coupled to the retaining strap release device. The outer two retaining straps can be attached directly to the module housing or to a gasbag opening fixed to the module housing, and thus be coupled directly or indirectly to the module housing. In this way, when the retaining strap release device is activated, the gasbag geometry is not only determined by the gasbag's shape but also remains subject to influence by the outer two retaining straps.

[0015] According to an alternative embodiment of the front gasbag module, all second ends of the retaining straps are coupled to the retaining strap release device. In this case, the gasbag geometry is determined primarily by the retaining straps when the retaining strap release device is not activated, and essentially by the shape of the gasbag when the retaining strap release device is activated.

[0016] According to a further alternative embodiment, at least three retaining straps are provided, wherein the second ends of the two outermost retaining straps (viewed in the transverse direction of the vehicle) are connected to the adjacent, at least one intermediate retaining strap. Compared to the embodiments mentioned above, this also allows for an advantageous contour of the impact surface, with the two outermost retaining straps being significantly shortened. This saves material, reduces the weight of the gas bag, and simplifies the retaining strap construction within the gas bag.

[0017] The invention further comprises a motor vehicle with a windscreen, an instrument panel, a steering wheel and a front airbag module as described above, wherein the front airbag module is attached to or in the instrument panel.

[0018] In particular, the front gasbag module is attached to or within the instrument panel in such a way that the gas flow direction when exiting a gas generator is approximately parallel to the windshield. This reduces the stress on the windshield caused by the deploying gasbag when the front gasbag module is activated.

[0019] According to a preferred embodiment of the motor vehicle, the front gasbag module is arranged in the area of ​​a windshield root of the vehicle, with the gap between the windshield and the instrument panel forming a launch channel for the front gasbag module, in which the gasbag deploys upon activation of the front gasbag module. The windshield root is defined as the leading edge of the windshield in the longitudinal direction of the vehicle, where the windshield and the instrument panel meet. In this position, a gas flow direction essentially parallel to the windshield can be achieved particularly easily. However, the deployment path of the gasbag is particularly long.

[0020] In this embodiment, a head-up display (HU) can be arranged below the firing channel between the front airbag module and the vehicle's steering wheel. These HUs are enjoying increasing popularity and can project a wide variety of vehicle information onto a portion of the windshield.

[0021] According to an alternative embodiment, the front airbag module is arranged longitudinally in the instrument panel between the windshield base and the steering wheel, thus shortening the airbag's deployment path in this position. However, the airbag initially deploys towards the windshield and is deflected by it into the gap between the windshield and the instrument panel, thereby placing greater stress on the windshield and slightly delaying the airbag's deployment. Since the front airbag module is quite close to the steering wheel in this mounting position, integrating a head-up display proves difficult.

[0022] Further features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the drawings. These show: - Fig. 1 a schematic longitudinal section through a motor vehicle according to the invention with a front airbag module according to a first embodiment in a driving position of the occupant; - Fig. 2 a schematic longitudinal section through the motor vehicle with the front airbag module according to Fig. 1 in a comfortable position for the occupant; - Fig. 3 a schematic top view of the front gasbag module according to Fig. 1; - Fig. 4 a schematic top view of the front gasbag module according to Fig. 2; - Fig. 5 a schematic longitudinal section through a motor vehicle according to the invention with a front gasbag module according to the invention in a first mounting position; - Fig. 6 a schematic longitudinal section through a motor vehicle according to the invention with a front gasbag module according to the invention in a second mounting position; - Fig. 7 a schematic longitudinal section through a motor vehicle according to the invention with a front airbag module according to a second embodiment in a driving position of the occupant; - Fig. 8 a schematic top view of the front gasbag module according to Fig. 7 in the occupant's driving position; - Fig. 9 a schematic top view of the front gasbag module according to Fig. 8 in a comfortable occupant position; - Fig. 10 a schematic longitudinal section through a motor vehicle according to the invention with a front airbag module according to a third embodiment in a driving position of the occupant; - Fig. 11 a schematic top view of the front gasbag module according to Fig. 10 in the occupant's driving position; - Fig. 12 a schematic top view of the front gasbag module according to Fig. 11 in a comfortable occupant position; - Fig. 13 a schematic longitudinal section through a motor vehicle according to the invention with a front airbag module according to a fourth embodiment in a driving position of the occupant; - Fig. 14 a schematic top view of the front gasbag module according to Fig. 13 in the occupant's driving position; - Fig. 15 a schematic top view of the front gasbag module according to Fig. 14 in a comfortable occupant position;

[0023] The Fig. 1 and Fig. Figures 2 each show a schematic longitudinal section through a motor vehicle 10 with a windshield 12, an instrument panel 14, a steering wheel 16 and a (deployed) front airbag module 18 according to a first embodiment, wherein the front airbag module 18 is attached to or in the instrument panel 14 (see also Fig. 5 and Fig. 6).

[0024] The front gasbag module 18, which is mounted in the direction of travel 20 in front of the vehicle steering wheel 16 on or in the instrument panel 14 of the motor vehicle 10, comprises an inflatable gasbag 22 for restraining an occupant 24 positioned behind the vehicle steering wheel 16 in the direction of travel 20, wherein the gasbag 22, when inflated, extends in an arc shape, viewed in the direction of travel 20, first along the windscreen 12 to the rear and then downwards between the occupant 24 and the vehicle steering wheel 16, and wherein the gasbag 22 has an impact surface 26 facing the occupant 24 and an opposing support surface 28 facing the vehicle steering wheel 16.

[0025] Furthermore, the front gasbag module 18 comprises at least one retaining strap 30, which has a first retaining strap end 34 attached to the impact surface 26 of the gasbag 22 and an opposite second retaining strap end 36, wherein an activatable retaining strap release device 38 is provided, which in a non-activated state is connected to the second retaining strap end 36 and in an activated state releases the second retaining strap end 36.

[0026] In the event of a triggering of the front airbag module 18 with the safety strap release device 38 not activated, the airbag 22 assumes a first contour in which a movement of the impact surface 26 in the direction of the occupant 24 is limited by the at least one safety strap 30 (cf. Fig. 1) This allows for good occupant restraint if the occupant 24 assumes a driving position according to Fig. 1 assumes an upright seating position in which the motor vehicle 10 is manually controlled via the vehicle steering wheel 16.

[0027] In the event of a triggering of the front airbag module 18 with the safety strap release device 38 activated, the airbag 22 assumes a second contour in which the impact surface 26 can move unhindered by the at least one safety strap 30 in the direction of the occupant 24 (cf. Fig. 2) This allows for good occupant restraint when the occupant 24 is in a comfortable position according to Fig. 2 assumes a relaxed reclining position in which the motor vehicle 10 is not controlled by the occupant 24, but via an autonomous or (partially) automated driving function.

[0028] In the comfort position, compared to the driving position, the vehicle seat 40 is adjusted backwards and / or the backrest of the vehicle seat 40 is swivelled backwards, so that the occupant 24 has a greater distance to the vehicle steering wheel 16 and the instrument panel 14. This greater distance is at least partially compensated for by the adaptive contour of the airbag 22, thereby achieving good restraint regardless of the occupant 24's seating position.

[0029] As in the Fig. 1 and Fig. As schematically indicated in Figure 2, the front gasbag module 18 has a module housing 42 in which the folded gasbag 22 and a gas generator 44 for filling the gasbag 22 with generator gas are housed, the safety strap release device 38 being attached to or in the module housing 42. In particular, the safety strap release device 38 can be arranged directly on the gas generator 44 or even integrated into it, as shown in Figure 2. Fig. 5 and Fig. 6 indicated. Since the gas bag 22 has a larger volume when deployed into its second contour than when deployed into its first contour, the gas generator 44 is, in particular, a two-stage gas generator 44, in which a second generator stage is only triggered when the restraint release device 38 is also activated and, accordingly, deployment of the gas bag 22 into its second contour is desired. Alternatively, a separate auxiliary generator can also be provided, which is operated analogously to the second generator stage. In this way, the internal pressure in the second contour of the gas bag 22 can be increased if this is desired for occupant restraint.

[0030] The Fig. 3 and Fig. Figures 4 each show a schematic top view of the first embodiment of the front gasbag module 18 according to the Fig. 1 and Fig. 2 in the driving position or the comfort position of the occupant 24. It becomes clear that several retaining straps 30 are provided, the first retaining strap ends 34 of which, viewed in the transverse and / or vertical direction of the motor vehicle 10, are attached to the impact surface 26 at intervals from each other.

[0031] If the second ends of the retaining straps 36 are held back by the retaining strap release device 38 in a driving position of the occupant 24, the gas bag 22 assumes its first contour according to Fig. 3, wherein the retention of the retaining strap in the impact surface 26 of the gas bag creates 22 deep pockets 46, which are in Fig. 1 are indicated by hatching. These pockets 46 also reduce surface tension in the impact surface 26, which advantageously leads to a less hard impact of the occupant 24 on the impact surface 26.

[0032] When the second ends of the retaining strap 36 are released by the retaining strap release device 38 in a comfortable position of the occupant 24, the gas bag 22 assumes its second contour according to Fig. 4. Due to the lack of retaining straps, the inverted pockets 46 disappear and the impact surface 26 bulges out towards the occupant 24, as in the Fig. 2 and Fig. 4. This reduces the distance between the impact surface 26 and the occupant 24 in the comfort position, so that in the event of a frontal impact of the motor vehicle 10, the occupant 24 is already slowed down and caught by the impact surface 26 of the airbag 22 after a short acceleration distance in the direction of travel 20.

[0033] The Fig. 5 and Fig. Figure 6 shows two different mounting positions of the front gasbag module 18, in each case the front gasbag module 18 being attached to or in the instrument panel 14.

[0034] According to Fig. In Figure 5, the front airbag module 18 is mounted in the instrument panel 14 directly behind a display device 48, for example, a monitor. In this so-called basic position, the front airbag module 18 is located close to the occupant 24, so that after module deployment, the deployment distance to the occupant 24 is comparatively short. A disadvantage of this mounting position is the high stress on the windshield 12, since the front airbag module 18 opens upwards and the deploying airbag 22 is deflected at the windshield 12 in the direction of the occupant 24, as indicated by arrow 50. Fig. 5 indicated. Therefore, measures may be necessary to reduce the deployment pressure of the gas bag 22 on the windscreen 12 and to prevent the windscreen 12 from breaking.

[0035] To reduce the load on the windshield 12, the front windshield airbag module 18 is designed according to Fig. 6 attached to (or in) the instrument panel 14 such that the direction of gas flow when exiting the gas generator 44 is approximately parallel to the windshield 12, as indicated by an arrow 52 in Fig. 6 indicated. In this so-called windscreen root position, the front gasbag module 18 is arranged in the area of ​​the windscreen root, i.e., in a contact area between the windscreen 12 and the instrument panel 14, with a gap 54 between the windscreen 12 and the instrument panel 14 forming a firing channel for the front gasbag module 18, in which the gasbag 22 unfolds when the front gasbag module 18 is activated. Since the gasbag 22 does not need to be deflected by the windscreen 12 in this case, there is less stress on the windscreen 12 after module deployment compared to mounting the front gasbag module 18 in the basic position according to Fig. 5, significantly less.

[0036] In addition, head-up displays are increasingly being used on the driver's side, which project warnings or information directly onto a section of the windscreen 12 in front of the driver.

[0037] According to Fig. 6 is a device 56 for a head-up display arranged below the firing channel between the front gasbag module 18 and the vehicle steering wheel 16. When the front gasbag module 18 is mounted in the basic position according to Fig. 5 the front gasbag module 18 is positioned significantly closer to the vehicle steering wheel 16, so that the integration of the device for a head-up display 56 cannot be realized at all or at least is difficult.

[0038] Starting from the first embodiment of the front gasbag module 18 according to the Fig. Alternative embodiments are presented below in sections 1 to 4, whereby the basic idea of ​​an adaptive gas bag 22, which can assume a first gas bag contour or a second gas bag contour depending on the seating position of the occupant 24 by means of retaining straps 30 and a retaining strap release device 38, remains unchanged. Therefore, only the distinguishing features of the individual embodiments will be discussed below, and reference is otherwise made to the description above.

[0039] The Fig. Figures 7 to 9 show the front airbag module 18 according to a second embodiment, in which at least three retaining straps 30, 32 are provided, wherein the two outer retaining straps 32, viewed in the transverse direction of the motor vehicle 10, are longer than the at least one intermediate retaining strap 30. Specifically, in the illustrated embodiment, two outer, longer retaining straps 32 and two inner, shorter retaining straps 30 are provided, which are arranged between the outer retaining straps 32. In this way, in the first airbag contour (see Figure 7 to 9) Fig. 7 and Fig. 8) When the safety strap release device 38 is not activated, lateral protrusions 58 are created when viewed in the transverse direction of the vehicle 10. These protrusions 58 prevent the occupant 24 from sliding laterally and also prove advantageous when the occupant 24 is not ideally positioned centrally when viewed in the transverse direction of the vehicle 10.

[0040] Analogous to the first embodiment according to the Fig. In this second embodiment of the front gasbag module 18, the second retaining strap ends 36 of all retaining straps 30, 32 are also coupled to the retaining strap release device 38.

[0041] In contrast, in the Fig. Figures 10 to 12 show a third embodiment of the front gasbag module 18, in which at least the second retaining strap ends 36 of the two outer retaining straps 32 are coupled to the module housing 42 and the second retaining strap end 36 of the at least one intermediate retaining strap 30 is coupled to the retaining strap release device 38. In this way, in the first gasbag contour (see Figure 10 to 12) Fig. 10 and Fig. 11) again implement the lateral bulges 58, which are advantageous for occupant restraint, analogous to the second embodiment. With the safety belt release device 38 activated according to Fig. However, the second ends of the retaining straps 36 of the two outer retaining straps 32 remain fixed to the module housing 42 and can therefore also contribute to stabilizing the gas bag position in the second contour of the gas bag 22.

[0042] The Fig. Figures 13 to 15 finally show a fourth embodiment of the front airbag module 18 with at least three retaining straps 30, 32, wherein the second retaining strap ends 36 of the two outer retaining straps 32, viewed in the transverse direction of the motor vehicle 10, are connected to the adjacent, at least one intervening retaining strap 30. In this way, first and second airbag contours can be realized which are essentially the same as the first and second airbag contours of the second embodiment according to the Fig.7 to 9 correspond, however, the two outer retaining straps 32 can be made shorter here, and the second retaining strap ends 36 of the two outer retaining straps 32 do not need to be connected to the retaining strap release device 38. Thus, compared to the second embodiment, the weight and complexity of the front gasbag module 18 are reduced.

Claims

[1] Front gasbag module for mounting on or in an instrument panel (14) of a motor vehicle (10) in the direction of travel in front of a vehicle steering wheel (16) with an inflatable gas bag (22) for restraining an occupant (24) positioned in the direction of travel (20) behind the vehicle's steering wheel (16), wherein the gasbag (22) in the inflated state extends in an arc shape first to the rear and then downwards between the occupants (24) and the vehicle steering wheel (16) and has an impact surface (26) facing the occupant (24) and an opposing support surface (28) facing the vehicle steering wheel (16), wherein at least one retaining strap (30, 32) is provided which has a first retaining strap end (34) attached to the impact surface (26) of the gas bag (22) and an opposite second retaining strap end (36), wherein an activatable trap release device (38) is provided which is connected to the second trap end (36) in a non-activated state and releases the second trap end (36) in an activated state, wherein the gasbag (22) assumes a first contour when the retaining strap release device (38) is not activated, in which a movement of the impact surface (26) in the direction of the occupant (24) is limited by the at least one retaining strap (30, 32), and when the retaining strap release device (38) is activated, assumes a second contour in which the impact surface (26) can move unhindered by the at least one retaining strap (30, 32) in the direction of the occupant (24). [2] Front gasbag module according to claim 1, characterized by, that the front gasbag module (18) has a module housing (42) in which the folded gasbag (22) and a gas generator (44) for filling the gasbag (22) with generator gas are accommodated, wherein the retaining strap release device (38) is attached to or in the module housing (42). [3] Front gasbag module according to claim 1 or 2, characterized by , that several retaining straps (30, 32) are provided, the first retaining strap ends (34) of which, viewed in the transverse and / or vertical direction of the motor vehicle (10), are attached to the impact surface (26) at intervals from each other. [4] Front gasbag module according to claim 3, characterized by , that at least three retaining straps (30, 32) are provided, wherein the two outer retaining straps (32) seen in the transverse direction of the motor vehicle (10) are longer than the at least one intermediate retaining strap (30). [5] Front gasbag module according to claim 4, characterized by, that at least the second ends (36) of the outer two retaining straps (32) are coupled to a module housing (42) of the front gasbag module (18) and the second end (36) of the at least one intermediate retaining strap (30) is coupled to the retaining strap release device (38). [6] Front gasbag module according to claim 3 or 4, characterized by , that all second trap ends (36) are coupled to the trap release device (38). [7] Front gasbag module according to claim 3, characterized by , that at least three retaining straps (30, 32) are provided, wherein the second retaining strap ends (36) of the two outer retaining straps (32) seen in the transverse direction of the motor vehicle (10) are connected to the adjacent, at least one intermediate retaining strap (30). [8] Motor vehicle comprising a windscreen (12), an instrument panel (14), a vehicle steering wheel (16) and a front airbag module (18) according to any of the preceding claims, characterized by, that the front gasbag module (18) is attached to or in the instrument panel (14). [9] Motor vehicle according to claim 8, characterized by , that the front gasbag module (18) is attached to or in the instrument panel (14) in such a way that the direction of flow of the gas when exiting a gas generator (44) is approximately parallel to the windscreen (12). [10] Motor vehicle according to claim 8 or 9, characterized by , that the front gasbag module (18) is arranged in the area of ​​a windscreen root of the motor vehicle (10), wherein the gap (54) between the windscreen (12) and the instrument panel (14) forms a firing channel of the front gasbag module (18) in which the gasbag (22) unfolds when the front gasbag module (18) is activated. [11] Motor vehicle according to claim 10, characterized by , that a device for a head-up display (56) is arranged below the firing channel between the front gasbag module (18) and the vehicle steering wheel (16).

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