WO2011059378A1

WO2011059378A1 - Motor vehicle and airbag module for a motor vehicle

Info

Publication number: WO2011059378A1
Application number: PCT/SE2010/051185
Authority: WO
Inventors: Alexander Gulde; Armin KRÄNZLE; Roland Peiz; Peter Gerisch; Reinhard BÖSWIRTH; Stefan Taubert; Marc Schock
Original assignee: Autoliv Development Ab
Priority date: 2009-11-10
Filing date: 2010-11-01
Publication date: 2011-05-19
Also published as: DE102009052395B4; DE102009052395A1

Abstract

The invention relates to an airbag module (4, 5) for a motor vehicle (1) comprising a gas generator (6, 7), wherein the airbag module (4, 5) comprises at least two separate inflatable airbags (8, 9, 10, 11),each of which is connected with the gas generator (6, 7) via a gas line (12, 13, 14, 15) allocated to each of them.

Description

Autoliv Development AB, 44783 Vargarda

Motor vehicle and airbag module for a motor vehicle

The invention relates to an airbag module for a motor vehicle comprising the features of the preamble of claim 1 as well as a motor vehicle comprising the features of the preamble of claim 8.

Airbag modules for motor vehicles are generally known and nor^¬ mally comprise an inflatable airbag and a gas generator for inflating the airbag. In case, the gas generator cannot be lo^¬ cated directly on the airbag, a gas line for connecting the gas generator with the airbag further needs to be provided. The shaping and the inflation characteristics of the infla^¬ table airbag are specifically adjusted to the vehicle struc^¬ ture to be covered and to the motion sequence of the passenger during the accident so that the probability of injuries or the severity of the potential injuries are reduced to a minimum by the airbag. As in modern motor vehicles the passenger protec^¬ tion is of particular importance, a plurality of airbag mo^¬ dules is provided in the passenger compartment of the motor vehicle with each airbag module for itself forming a pre-moun- ted unit and being attached to the motor vehicle at a fixing point specifically provided for the airbag module.

An airbag system, in particular a head airbag system, which comprises a central gas generator inflating several inflatable airbags via a hollow sealed roof structure, is already known from WO 99/30932 Al . An essential disadvantage of this solu^¬ tion is that the sealing of the hollow roof structure is very complex, and that the hollow roof structure constitutes a sig^¬ nificant modification of the vehicle structure of the motor vehicle. Such a modification of the vehicle structure, how^¬ ever, is often hard to realize merely for stability reasons. Furthermore, the hollow spaces required for the gas supply constitute a major narrowing of the passenger compartment of the motor vehicle, what is not acceptable in particular in compact vehicles.

It is therefore an object of the invention to provide a cost- effective airbag module which provides a highest possible pro^¬ tection of the passenger and requires an installation space as small as possible and as little assembly effort as possible. It further is an object of the invention to provide a cost- effective passenger protection for a motor vehicle which comprises a front seat and a back seat having different distances from the inner side structure of the motor vehicle.

The objects are solved according to the invention by an airbag module comprising the features of claim 1 and a motor vehicle comprising the features of claim 8. Further preferred embodi^¬ ments of the invention can be learned from the sub claims, the figures and the related description.

For solving the set object an airbag module for a motor vehi^¬ cle is proposed, which comprises a gas generator and at least two separate inflatable airbags, each of which is connected with the gas generator via a gas line allocated to each of them. The advantage of the proposed airbag module is that with one airbag module using one gas generator two inflatable air- bags which cover different parts of the passenger compartment of the vehicle can be inflated, whereby compared to the solu^¬ tions known from prior art one gas generator is saved. By sa- ving the gas generator the total costs and the total installa^¬ tion space required for the passenger protection are reduced. The reduction of the required installation space is advanta^¬ geous in particular in compact vehicles, in which the passenger compartment is particularly small and shall be narrowed as little as possible.

It is further proposed that the inflatable airbags are allo^¬ cated to different sides of the motor vehicle. By using the proposed solution an airbag module is provided, by means of which both sides of the inner side structure of the vehicle can be covered by an inflatable airbag. In this case, a pas^¬ senger can be protected by an inflatable airbag towards both sides in very small compact vehicles comprising one seat only or only a single row of seats using one single airbag module.

Furthermore, the inflatable airbags can also be provided for the protection of different passengers so that for example a driver and a passenger sitting next to him or behind him can be protected by the inflatable airbags.

It is further proposed that the gas generator is located on a central roof brace of the vehicle structure behind a front seat. The roof brace owing to its function of stiffening the vehicle body constitutes an ideal fixing point which in addi^¬ tion allows the inflatable airbags to be filled at the diffe^¬ rent sides of the inner side structure using gas lines which are as short as possible and of an equal or a similar length. As the roof brace is located behind the vehicle seat, a fur^¬ ther advantage arises, i.e. that the gas generator is not lo^¬ cated directly above the head, but at a distance from the head of the driver so that the threat to the driver posed by the gas generator when being activated is as low as possible. In motor vehicles comprising multiple seats, the roof brace fur^¬ ther constitutes an ideal fixing point, as the gas generator thereby keeps a distance from the other passengers as well, which distance owing to the arrangement on the roof brace does not go below a largest possible minimum distance from each passenger .

In this case, it is further proposed that the gas generator is designed to be tubular and is located on the roof brace in such a way that its longitudinal axis runs parallel to the roof brace.

It is further proposed that the inflatable airbags are located on the inner side structure of the motor vehicle and, in a top view of the motor vehicle, form a U or a Z due to the connec^¬ tion with the gas generator via the gas lines. Due to the pro^¬ posed arrangement of the inflatable airbags, of the gas lines as well as of the gas generator in a U or a Z the inflatable airbags can ideally be used as head airbags with the gas gene^¬ rator not being located directly above the head of the passen^¬ ger or the heads of the passengers, but, from the perspective of the passenger sitting in the front seat, it is displaced rearwards .

For the solution of the object, a motor vehicle comprising a front seat and a back seat which at their sides have different distances from the inner side structure of the motor vehicle is further proposed with an airbag module according to one of the claims 1 to 7 being provided for the protection of the passengers sitting in the front seat and in the back seat, and the inflatable airbags being located on the sides of the inner side structure having the smaller distance from the front seat and the back seat. The proposed motor vehicle is for example a compact vehicle comprising two single seats which are stag^¬ gered with respect to each other. Both inflatable airbags are located on the side of the side structure having the smaller distance from the respective seat so that they can ideally be designed as head airbags for the side impact onto this nearer side (Near Side Impact) . In summary, a head airbag can thus be provided for both passengers using one single airbag module. The inflation behaviour and the start of the inflation can be identical for both airbags so that the airbag module can have an overall symmetric design and an essentially higher number of identical parts can be used.

It is further proposed that a second airbag module according to one of the claims 1 to 7 is provided, and that the infla^¬ table airbags are located on the sides of the inner side structure having the larger distance from the front seat and the back seat. In that case, the second airbag module with the proposed airbags on the inner side having the larger distance from the single seats is intentionally designed for the side impact onto the farther side (Far Side Impact) and the infla^¬ table airbags of this second airbag module can be identical as well .

In this case, it is proposed that the inflatable airbags of the first and the second airbag module are inflated at diffe^¬ rent times and/or stay inflated for different periods of time and/or have a different filling volume. Due to the inflation at different times, to the different periods of time for which they stay inflated and to the different filling volume the passenger can be protected against directly hitting the side structure in spite of the different distances from the sides of the inner side structure of the motor vehicle by taking into account the motion sequence of the passenger likely to occur during an accident when determining the inflation characteristics. The different periods of time for which they stay inflated can be realized for example by the use of venti^¬ lation openings or by the design of the flow connections, through which the gas can escape from the airbag or flows into the airbag.

In the following, the invention is described in more detail on the basis of a preferred embodiment. It is shown:

Fig. 1: Top view of a schematic representation of a motor vehicle with two airbag modules

Fig. 1 shows a top view of a schematic representation of a mo^¬ tor vehicle 1. In the motor vehicle 1, a front seat 2 and a back seat 3 are located behind each other and in staggered po^¬ sitions. Due to the staggered arrangement of the seats behind each other they have different distances from the sides of the inner side structure of the motor vehicle 1 resulting in dif^¬ ferent accident scenarios for the passengers in the front seat 2 and in the back seat 3 in the event of a side impact, i.e. either a "Far Side Impact" or a "Near Side Impact".

Two airbag modules 4 and 5 according to the invention are at^¬ tached to a central roof brace 16 running between the front seat 2 and the back seat 3. The airbag module 4 includes a gas generator 6 which is flow-connected with the separate infla^¬ table airbags 10 and 11 via two gas lines 14 and 15. The in^¬ flatable airbags 10 and 11 are located on the inner side of the side structure of the motor vehicle 1, i.e. on the side of the side structure having the smaller distance from the front seat 2 and the back seat 3. The inflatable airbags 10 and 11 thus serve to protect the passenger in the event of a "Near Side Impact". The airbags 10 and 11 are thus inflated at an early stage during the accident scenario and their surfaces are adjusted to a strongly limited area of the inner side structure of the motor vehicle 1, as the area which would be hit by the passenger in the event of a side impact due to the small distance can be localized in a relatively exact manner.

A second airbag module 5 also comprising two inflatable air- bags 8 and 9 which are flow-connected with a joint gas genera^¬ tor 7 via gas lines 13 and 12 is further located on the roof brace 16. Each of the inflatable airbags 8 and 9 is located on the side of the inner side structure of the motor vehicle 1 having a larger distance from the front seat 2 and the back seat 3 and serves to protect the passenger in the event of a "Far Side Impact". The airbags 8 and 9 have a larger filling volume and are inflated a bit later than the airbags 10 and 11, as the passenger in the event of an accident due to the larger distance hits them at a later time, and as the area which is likely to be hit by the passenger is much harder to predict. Thus, due to the arrangement of the seats, depending on the impact side, the accident scenario of a "Far Side Im^¬ pact" or a "Near Side Impact" arises for a passenger in the front seat 2, whereas for a passenger in the back seat 3 in^¬ volved in the same accident the respective other accident sce^¬ nario arises.

It would as well be possible to use one single airbag module 4 or 5 by combining the gas generators 6 and 7 to one single gas generator, and to realize the different inflation characteris^¬ tics by the use of corresponding ventilation openings or by the flow-related design of the gas lines 12, 13, 14, 15. The gas lines 12, 13, 14, 15 are preferably designed as fabric tubes facilitating the mounting of the airbag modules 4 and 5 in the motor vehicle 1.

The essential advantage of the invention evidently is that the protection of the passenger towards both sides of the side structure of the motor vehicle can be realized using as few airbag modules as possible or even using one single airbag module only or rather using one single gas generator only without the need for a complex preparation or modification of the vehicle structure. The installation space required for the airbag devices then is much smaller compared to a conventional arrangement with separate airbag modules each. Furthermore, the gas generator is intentionally located on the roof struc^¬ ture, preferably on the roof brace 16 so that the airbag mod^¬ ule 4 or 5 can also be mounted in vehicles, in which the in^¬ stallation space required for locating the airbag modules 4 or 5 is not available at the roof edge limiting the side windows at the top. As the gas generator 6 or 7 in the airbag modules 4 or 5 in the non-activated state requires the major part of the installation space, considerable installation space can be saved at the roof edge limiting the side windows by relocating the gas generators 6 or 7 into the roof brace 16. Furthermore, the roof brace 16 lends itself inasmuch as due to its function it already offers a high strength and, in addition, normally comprises hollow spaces which can be used for locating the gas generator 6 and 7 and the gas lines 12, 13, 14, 15.

Claims

Claims :

1. Airbag module (4, 5) for a motor vehicle (1) comprising a gas generator (6, 7), characterized in that the airbag module (4, 5) comprises at least two separate inflatable airbags (8, 9, 10, 11), each of which is connected with the gas generator (6, 7) via a gas line (12, 13, 14, 15) allocated to each of them.

2. Airbag module (4, 5) according to claim 1, characterized in that the inflatable airbags (8, 9, 10, 11) are allo^¬ cated to different sides of the motor vehicle (1) .

3. Airbag module (4, 5) according to any one of the preceding claims, characterized in that the inflatable airbags (8,

9, 10, 11) are provided for the protection of different passengers .

4. Airbag module (4, 5) according to any one of the preceding claims, characterized in that at least one inflatable air- bag (8, 10) is provided for the protection of a passenger sitting in a front seat (2) and one inflatable airbag (9, 11) is provided for the protection of a passenger sitting in a back seat (3) .

5. Airbag module (4, 5) according to any one of the preceding claims, characterized in that the gas generator (6, 7) is located on a central roof brace (16) of the vehicle struc^¬ ture behind a front seat (2) .

6. Airbag module (4, 5) according to any one of the preceding claims, characterized in that the gas generator (6, 7) is designed to be tubular and is located on the roof brace (16) in such a way that its longitudinal axis runs paral^¬ lel to the roof brace (16) .

7. Airbag module (4, 5) according to any one of the preceding claims, characterized in that the inflatable airbags (8,

9, 10, 11) are located on the inner side structure of the motor vehicle (1) and, in a top view of the motor vehicle

(1), form a U or a Z due to the connection with the gas generator (6, 7) via the gas lines (12, 13, 14, 15) .

8. Motor vehicle (1) comprising a front seat (2) and a back seat (3) which at their sides have different distances from the inner side structure, characterized in that an airbag module (4) according to one of the claims 1 to 7 is provided for the protection of the passengers sitting in the front seat (2) and in the back seat (3), and that the inflatable airbags (10, 11) are located on the sides of the inner side structure of the motor vehicle having the smaller distance from the front seat (2) and the back seat (3) .

9. Motor vehicle (1) according to claim 8, characterized in that a second airbag module (5) according to one of the claims 1 to 7 is provided, and that the inflatable airbags (8, 9) are located on the sides of the inner side struc^¬ ture of the motor vehicle (1) having the larger distance from the front seat (2) and the back seat (3) .

10. Motor vehicle (1) according to claim 9, characterized in that the inflatable airbags (8, 9, 10, 11) of the first and the second airbag module (4, 5) are inflated at dif^¬ ferent times and/or stay inflated for different periods of time and/or have a different filling volume.