Patent Application
20080073883
The airbag 12 shown here is a side-impact airbag having several inflatable chambers 17 that, in a generally known manner, are separated from each other by non-inflatable sections or seams. Essentially the airbag 12 consists of two layers of fabric that are sewed or woven together.
The holding element 16 has a rigid, elongated, preferably flat base 18. The base 18 is rod-shaped. A fastening section 20 is provided at each end of the base 18. For this purpose, the material of the base is rolled up to form an eyelet that extends perpendicular to a lengthwise direction L of the base 18 (see, for example,
The eyelets are configured so as to each accommodate a fastening means 22 that allows the holding element 16 to be fastened to a vehicle part with the fastening means 22 extending perpendicular to the lengthwise direction L and parallel to the flat top of the base 18. The airbag module 10 shown is fastened along a roof frame under an interior cladding of the vehicle.
The fastening means 22, for example, screws, can be inserted into the fastening section 20, as seen in the lengthwise direction L of the base 18, both from the right-hand side as well as from the left-hand side of the base 18. This has the advantage that the holding element 16 can be used for fastening an airbag module 10 on the driver's side as well as on the passenger's side of a vehicle.
The holding element 16 is essentially mirror-symmetrical relative to the lengthwise direction L.
The end sections of the base 18 are rolled up here in the same direction in order to form the fastening sections 20. However, the manner in which the end of the base 18 is rolled up in order to form the fastening section 20 is, of course, left up to the discretion of the person skilled in the art.
At about one-third of the length of the base 18, an opening 24 is provided that runs perpendicular to the top of the base 18 and that serves to fasten the gas generator 14 to the holding element 16. Projecting through the opening 24 is a fastening bolt 26 or another suitable fastening section that is joined to the gas generator 14, that projects radially therefrom and that is affixed to the holding element 16 by a nut 28.
Further, at a sufficient distance from the opening 24, the base 18 has an indentation 30 that serves to hold a clamp 32 which, in turn, secures the gas generator 14 in a second position on the holding element 16. The clamp 32 also surrounds an insertion opening of the airbag 12 and closes it so as to be gas-tight. The indentation 30 prevents the clamp 32 from moving in the lengthwise direction L of the holding element 16.
The holding element 16 is shown arranged outside of the airbag 12. However, it could also be situated at least partially inside the airbag 12.
The end of the gas generator 14 located in the airbag 12 has an outflow area 34 with various individual outflow openings that are each formed in the outer wall of the gas generator 14. The outflow openings in the outflow area 34 are largely arranged in an opposed manner so that the gas generator 14 is essentially thrust-neutral when all of the outflow openings of the outflow area 34 are exposed.
Before the gas generator 14 is activated, the outflow area 34 is surrounded by a gas baffle plate 36. In the example shown, the gas baffle plate 36 consists of a metal plate formed of a one-piece blank that can be spread out flat. The gas baffle plate 36 is bent in such a way that it surrounds the gas generator 14 in the form of a tube. Here, the end sections 38 are laid over each other so that the end sections 38 overlap, preferably by a few centimeters.
The tube thus formed serves to guide gas to various inflatable chambers of the airbag 12 (see
In a center region is situated between the end sections 38 that projects further in the lengthwise direction L than the end sections 38, an opening 39 (shown in
The airbag 12 has a partition 40 (
As an alternative or in addition, as in the embodiment shown, in order to create the vehicle occupant restraint system, the airbag module 10 is installed in a vehicle in such a way that the gas baffle plate 36 is arranged in the immediate vicinity of a vehicle-fixed part 42, here a section of the car body. The outer of the end sections 38 can already be supported on the vehicle-fixed part 42, here the roof frame, or else can be installed with a small gap with respect to the vehicle-fixed part 42.
The gas baffle plate 36 fulfills the functions described below. In the case of a normal activation of the airbag module 10, the airbag module 10 is mounted in a vehicle as shown in
The gas flow exerts a force that is oriented radially outwards on the gas baffle plate 36 and strives to spread the end sections 38 apart and to bend open the gas baffle plate 36.
During normal activation, the partition 40 of the airbag 12 prevents the gas baffle plate 36 from unrolling since the airbag 12 tightly surrounds the gas baffle plate and exerts a sufficient force against the gas flow.
As an alternative or in addition, the gas baffle plate 36 is supported on the vehicle-fixed part 42 so that the force of the air flow can be introduced into the vehicle and the gas baffle plate 36 is prevented from unrolling. In this case, the airbag 12 does not have to surround the gas baffle plate 36 so tightly, as is shown by the broken lines in
The case is different when the airbag module 10 is not yet installed in the vehicle. Activation of the airbag module 10 in the uninstalled state is generally simulated in the so-called bonfire test. Here, the entire airbag module 10 is exposed for a prolonged period of time to an elevated ambient temperature of, for instance, 160° C. [320° F.]. The requirement is that the gas generator 14 has to ignite spontaneously and to burn in a controlled manner, during which the entire airbag module 10 should behave thrust-neutrally.
Under the conditions of such a bonfire test, the fabric of the airbag 12 will break down or soften. So when gas from the gas generator 14 comes out of the outflow area 34, the partition 40 of the airbag 12 cannot resist the force of the gas flow and the partition 40 no longer holds gas baffle plate 36 in the rolled-up state.
Moreover, since the gas baffle plate 36 is not situated close to the vehicle-fixed part 42 and consequently cannot be supported by it the latter, it will bend open (at least approximately) to form the state shown in
In contrast, when the airbag module is activated when it is installed in the vehicle, the gas baffle plate 36 fulfills its function of distributing the gas flow and of protecting the airbag fabric during the complete activation phase.
In a second embodiment, which is shown in
When the airbag module of this embodiment is subjected to a bonfire test outside of the vehicle, the material of the gas-guiding tube 136 breaks down and fails so that the outflow area 34 of the gas generator 14 is uncovered and the airbag module 10 becomes at least approximately thrust-neutral.
Another embodiment is described with respect to
The airbag module 200 shown there likewise comprises an airbag 12 with several inflatable chambers as well as a gas generator 14 in the form of an elongated tubular gas generator.
The gas generator 14 is largely arranged inside the airbag 12.
An elongated holding element 216, shown in greater detail in
An indentation 30 for securing the position of a clamp 32 is likewise provided.
Like in the first embodiment, in this case as well, the holding element 216 is configured essentially mirror-symmetrical to its lengthwise direction L.
Unlike the first embodiment, in the area of the opening 224 for fastening the gas generator 14, the shape of the holding element 216 is adapted to the shape of the outer wall of the gas generator 14. In the present example, this is done by creating one or more beads.
A gas-distributing tube 236 (see
Analogously to the gas-distributing tube described in
Due to the adapted shape of the wall of the holding element 216 in the area of the opening 224, the gas-distributing tube 236—which is made, for example, of an airbag fabric—is held virtually gas-tight between the holding element 216 and the outer wall of the gas generator 14 so that no gas can escape from the airbag 12 at this place.
The holding element 216 could also be arranged outside of the airbag 12.
The sealing effect brought about by the shape adaptation of the holding element 216 in the area of the opening 224 could also be utilized to fasten the airbag 12 to the holding element 216 in a gas-tight manner.
Here, the second end of the holding element 316 with the second fastening section 20 is only slightly behind the opening 24 through which the fastening bolt 26 of the gas generator 14 protrudes.
Both fastening sections 20 are bent away from the gas generator 14 and rolled up in opposite directions.
An indentation 330 of the holding element 316 engages in a circumferential indentation 360 of the gas generator 14. In the area of the indentation 330, two fastening means 362 in the form of tabs for a holding bracket 332 that partially surrounds the gas generator 14 are created on the base 18 of the holding element 316 symmetrically to the lengthwise direction L. The holding bracket 332, which assumes the function of the clamp 32 in this embodiment, engages in the tabs on both sides in order to secure the gas generator 14 and, if applicable, the inflation opening of the airbag 12 (not shown here), to the holding element 316.
The holding bracket 332 is initially U-shaped and is pushed with its ends through the tabs. Subsequently, the ends are bent over.
Two hook-shaped pre-fastening projections 364 are formed on the holding element 316 between the indentation 330 and the opening 24, each of these projections extending perpendicular to the lengthwise direction L of the holding element 316 and defining the position of the gas generator 14 with respect to the holding element 316, at least temporarily.
The individual features of the presented embodiments can be combined with each other or switched with each other at the discretion of the person skilled in the art.
The embodiment of the gas baffle plate 36 presented here can also be used completely independently of the use of the described holding element 16. Such a configuration lends itself wherever a gas generator or an airbag module is supposed to have thrust-neutrality when it is not installed in the vehicle, while during normal actuation, some of the outflow openings are covered and a gas-guiding function is to be achieved. By the same token, the use is not limited to airbag modules arranged underneath an interior cladding.
Moreover, the use of a gas-distributing tube of the embodiment just described as well as the sealing of the gas-distributing tube by means of a holding element whose shape is adapted to the gas generator is independent of the specifically described form of the holding element 216.
By the same token, of course, the holding element 16, 216, 316 can be used in any other suitable airbag modules.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2006 045 245.3 | Sep 2006 | DE | national |
