WO2020064449A1

WO2020064449A1 - Vehicle seat arrangement

Info

Publication number: WO2020064449A1
Application number: PCT/EP2019/074943
Authority: WO
Inventors: Johann Unger; Rüdiger Lang
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 2018-09-25
Filing date: 2019-09-18
Publication date: 2020-04-02
Anticipated expiration: 2021-03-25
Also published as: DE102018123633A1; DE102018123633B4

Abstract

The present invention relates to a vehicle seat arrangement for a motor vehicle, with - a backrest (1), - a seat cushion (2), - two airbag modules (3.1, 3.2), the airbag modules (3.1, 3.2) being arranged on opposite lateral sides of the backrest (1) and each airbag module (3.1, 3.2) comprising at least one airbag (4.1, 4.2), and - a tether mechanism (5.1, 5.2) for each airbag module (3.1, 3.2), each tether mechanism (5.1, 5.2) comprising at least one first tether arrangement (6.1), the first tether arrangement (6.1) being fixed to the airbag (4.1), to the seat cushion (2) with one end and to the backrest (1) with the other end, characterized in that, at least one tether mechanism (5.1, 5.2) comprises at least one second tether arrangement (6.2), the second tether arrangement (6.2) being fixed to the airbag (4.2), to the seat cushion (2) with one end and to the backrest (1) with the other end.

Description

Vehicle seat arrangement

Description

The present invention relates to a vehicle seat arrangement for a motor vehicle, with a backrest, a seat cushion, two airbag modules, the airbag modules being arranged on opposite lateral sides of the backrest and each airbag module comprising at least one airbag, and with a tether mechanism for each airbag module, each tether mechanism comprising at least one first tether arrangement, the first tether arrangement being fixed to the airbag, to the seat cushion with one end and to the backrest with the other end.

A vehicle seat arrangement with the above features is known from US 2017 / 0259774 Al . The tether arrangement for each airbag extends along the outer lateral side of the inflated airbag, so that the airbag and the tether

arrangement holding the inflated airbag are embodied to protect the passenger against a side impact.

In order to protect the passenger in case of a front impact, an additional conventional airbag, i.e. in the dashboard of the vehicle or in the steering wheel, is needed. But, in future (self-driving vehicles) the seat might not be directed in the longitudinal direction of the vehicle, so that additional protection is needed. Accordingly, it is an object of the present invention, to provide a vehicle seat arrangement, with which the passenger is protected in different kind of impact situations, even if the seat is not aligned in the longitudinal direction of the vehicle.

This object is solved by a vehicle seat arrangement with the features of the independent claim. Preferred embodiments of the vehicle seat arrangement are subject matter of the dependent claim and the description, wherein the preferred embodiments can be combined with each other in a technical meaningful manner.

In particular, the object is achieved with a vehicle comprising the above features, wherein one or each tether mechanism comprises at least one second tether arrangement, the second tether arrangement being fixed to the airbag, to the seat cushion with one end and to the backrest with the other end. By having a second tether arrangement, the inflated airbag can be brought and kept in such a position, that at least one airbag is held in front of the passenger.

In particular, the fixing point of the first tether arrangement to the seat cushion is behind the fixing point of the second tether arrangement to the seat cushion, in particular at the lateral side of the seat cushion. Preferably, the fixing point of the second tether arrangement to the seat cushion is at the front of the seat cushion.

The other ends of the tether arrangements are preferably connected to the backrest at an upper part of the backrest, preferably on top of the backrest near the head rest.

The airbag module may comprise exactly one or more airbags. At least one airbag of the airbag modules is inflated at least partly in front of the

passenger, while at least one tether arrangement extends in the inflated state along the front side of the inflated airbag. The tether arrangement is arranged on the outside of the airbag.

Each tether arrangement may be made of one single tether, which is usually made of a tensile fabric. If each tether arrangement comprises only one tether, the airbag module and the tether need to be assembled in the vehicle seat at the same time.

In the assembled and not inflated state the tethers usually run below a fabric of the seat and even behind trim parts seat cushion foam. Assembling the tether arrangements together with the airbag module is therefore work intensive.

But, it might be desirable, that the airbag module and the tethers are to be assembled independent of each other. In this regard it is suggested, that each tether arrangement is made of multiple tethers. In this case, the tethers connected directly to the backrest and to the seat cushion may be assembled together with the other parts of the seat arrangement, wherein the airbag module can be assembled at a later stage. This way it is also more easy to install the tethers connected to the seat and the backrest.

In this regard it is preferable, if the tether arrangement is made of at least three tethers. The first tether being fixed to the seat cushion with one end, the second tether being fixed to the bracket with one end, wherein the other ends of the first tether and the second tether are connected to at least one third tether, the at least one third tether being fixed to the airbag. The third tether may be the airbag itself. This way, the first and second tethers can be assembled during the usual assembly of the vehicle seat, while the airbag module with one or two third tethers can be assembled later, wherein the one or two third tethers can be connected to the first and second tether after installation of the airbag module. It is desirable that the pressure level and the damping requirements for front impact crashes and side impact crashes are different. For example, the required positioning time for side impact application is approximately 50 % faster than for front load cases. In view of this it is suggested, that the damping and/or pressure can be adjusted by an active ventilation of the airbag or that the inflation of the airbag can be adjusted by volume variation of the gas supplied by the inflator. This way the desired pressure/damping could be adapted to front and/or side load cases.

In order to adapt the pressure and/or damping during deployment, it is also suggested that a length of the tether arrangement between its ends can be extended during deployment. With a (initial) shorter tether arrangement, the volume of the airbag is smaller and therefore the airbag will faster position with higher pressure, as needed for side impacts. When having longer tether arrangements the volume of the airbag is higher and the pressure is lower, which is desirable for front impacts.

In one embodiment to alter the length of the tether arrangement during deployment, it is suggested that a tether of the tether arrangement is connected to itself by a tear seam, which tear seam ruptures during

deployment. For example, the tether may be folded on itself, so that a fold is produced, which is secured by the tear seam. Thus, the tether arrangement has an initial effective length. When during deployment the tether is stretched by the inflating airbag and if then a respective force is exceeded, the tear seam ruptures, so that the overall length of the tether arrangement between its fixing points is extended. This way the airbag can deploy further in the direction which was previously delimited by the initial (effective) length of the respective tether arrangement.

In an alternative embodiment for altering the effective length of the tether arrangement, it is suggested, that the tether arrangement comprises at least one band, which is connected with its ends to at least one tether of the tether arrangement, such that the length of the band between the connection points (to the tether(s)) is shorter than the length of the tether arrangement between the connection points.

The band may be stiff and either rupture after a critical force is applied to the stiff band or the band may be destroyed by an actuator on demand. This way the deployment of the airbag is restricted to a first volume (defined by the initial effective length of the tether arrangement) and the volume of the airbag is enlarged after the stiff band is ruptured or actively destroyed.

Alternatively, the band may be elastic, wherein the elastic band and therefore the effective length of the tether arrangement expands during deployment of the airbag. This way the airbag can deploy until the tether arrangement is stretched to its initial effective length, wherein after a critical force onto the tether arrangement is exceeded, the band may be expanded, so that also the volume of the airbag is enlarged.

The invention and the technical background are explained with regard to the figures, which show exemplary embodiments of the invention in a schematic way.

Figure 1 : shows a vehicle seat arrangement with two airbag modules in an uninflated state,

Figure 2 : shows the vehicle seat arrangement in front view in an

inflated state of the airbags,

Figure 3 : shows the vehicle seat arrangement in an inflated state in side view,

Figure 4: shows a schematic side view of a vehicle seat arrangement,

Figure 5 : shows a tether of the vehicle seat arrangement, Figure 6: shows a further tether of a vehicle seat arrangement,

Figure 7: shows a top view onto the vehicle seat arrangement with inflated airbags according to Figures 2 and 3.

The vehicle seat arrangement shown in figures 1 to 4 and 7 comprises a vehicle seat with a backrest 1 and a seat cushion 2. Two airbag modules 3.1 and 3.2 are arranged on opposite lateral sides of the backrest 1 . The airbag modules 3.1 and 3.2 each comprise an airbag 4.1 and 4.2, respectively. A tether mechanism 5.1 and 5.2 is assigned to each of the airbag modules 3.1 and 3.2, respectively.

As can be seen best from figures 2 and 3 each tether mechanism comprises a first tether arrangement 6.1 and a second tether arrangement 6.2. The first tether arrangement 6.1 extending along the lateral side of the inflated airbag the second tether arrangement 6.2 extending along the front side of the inflated airbag. Each tether arrangement 6.1 and 6.2 comprises a first tether 7. 1 fixed to the seat cushion 2 with an end and a second tether 7.2 fixed to the backrest 1 with an end. Each tether arrangement 6.1 and 6.2 further comprises a third tether 7.3, which is connected to the respective airbag 4. 1 and 4.2 and which is further connected with its ends to the first tether 7.1 and to the second 7.2. By having multiple tethers 7.1 , 7.2 and 7.3 it is possible, that during assembly of the vehicle seat arrangement the first tether 7.1 and the second tether 7.2 of all tether arrangements are fixed to the base structure of the seat cushion, while the respective airbag module 3.1 and 3.2 with the airbags 4.1 and 4.2 can be assembled later, so that after assembling of the airbag modules only the first tethers 7.1 and the second tethers 7.2 need to be connected to the respective third tethers 7.3.

As far as the inflation of the airbags 4.1 and 4.2 to the lateral side is limited by the first tether arrangements 6.1 and to the front by the second tether arrangements 6.2 it is also suggested that the length of each tether arrangement 6.1 and 6.2 between its fixing points to the backrest 1 and to the cushion seat 2 can be altered during inflation.

For such passive adaption of the length of the tether arrangement it is suggested that at least the first tether arrangements 6.1 and/or the second tether arrangements 6.2 have a folded tether 7 (see figure 4), which fold of the tether is secured by a tear seam 8. The inflation of the airbag is then limited by the initial effective length of the respective tether arrangement during a first stage of inflation (see also dotted line in Fig. 7). If the force applied through the inflating airbag on the tether 7 exceeds a critical value the tear seam 8 ruptures, so that the effective length of the tether 7 is elongated, in which turn the airbag can inflate further during a second stage of inflation of the airbag in the direction which was previously delimited by the initial effective length of the tether arrangement.

A further possibility to enlarge the length of the tether arrangement during inflation is depicted in figure 6. According to this embodiment, a band 9 is provided, which is connected with its end to a tether 7. The band 9 may be stiff or of an elastic material. The stiff band 9 may rupture, if a force exceeds a critical limit during inflation of the airbag or may be actively cut by an actuator. Also in this embodiment the airbag inflates until the band 9 is stretched during a first stage of inflation, while the airbag may inflate further if the band 9 is ruptured or is elastically expanded, after a critical force is exceeded.

From the dotted lines in figure 7 it can be seen, that during the initial stage of inflation the airbags only expand partly towards the front of the seat, as the initial effective length of the tether arrangements 6.2 is limited, while after rupturing of the tear seam 8 or of the band 9 the effective length of the tether arrangements 6.2 is enlarged, so that the airbags 4.1 and 4.2 can deploy further to the front. Reference signs

Backrest

Seat cushion

Airbag module

Airbag

Tether mechanism

Tether arrangement

Tether

Tear seam

Band

Claims

1 , Vehicle seat arrangement for a motor vehicle, with

a backrest (1 ),

a seat cushion (2),

two airbag modules (3.1 , 3.2), the airbag modules (3.1 , 3.2) being arranged on opposite lateral sides of the backrest ( 1 ) and each airbag module (3.1 , 3.2) comprising at least one airbag (4.1 , 4.2), and

a tether mechanism (5.1 , 5.2) for each airbag module (3.1 , 3.2), each tether mechanism (5.1 , 5.2) comprising at least one first tether arrangement (6.1 ), the first tether arrangement (6.1 ) being fixed to the airbag (4.1 ), to the seat cushion (2) with one end and to the backrest (1 ) with the other end,

characterized in that,

at least one tether mechanism (5.1 , 5.2) comprises at least one second tether arrangement (6.2), the second tether arrangement (6.2) being fixed to the airbag (4.2), to the seat cushion (2) with one end and to the backrest ( 1 ) with the other end.

2. Vehicle seat arrangement according to claim 1 , wherein each tether arrangement (4.1 ) is made of multiple tethers (7.1 , 7.2, 7.3).

3. Vehicle seat arrangement according to claim 2, wherein each tether arrangement (6.1 , 6.2) is made of at least three tethers, the first tether (7. 1 ) being fixed to the seat cushion (2) with one end, the second tether (7.2) being fixed to the backrest (1 ) with one end, wherein the other ends of the first tether (7.1 ) and the second tether (7.2) are connected to at least one third tether (7.3), the at least one third tether (7.3) being fixed to the airbag (4.1 , 4.2).

4. Vehicle seat arrangement according to one of the preceding claims, wherein a length of at least one tether arrangement (6.1 , 6.2) between its ends can be extended during deployment.

5. Vehicle seat arrangement according to claim 4, wherein a tether (7.1 , 7.2, 7.3) of the tether arrangement (6.1 , 6.2) is connected to itself by a tear seam (8), which tear seam (8) ruptures during deployment of the airbag.

6. Vehicle seat arrangement according to claim 4 or 5, wherein the tether arrangement (6.1 , 6.2) comprises at least one band (9), the band (9) being connected with its ends to at least one tether (7.1 , 7.2, 7.3) of the tether arrangement (6.1 , 6.2), such that the length of the band (9) between the connections points is shorter than length of the tether arrangement (6.1 , 6.2) between the connection points.

7. Vehicle arrangement according to claim 6, wherein the band (9) is stiff.

8. Vehicle arrangement according to claim 7, wherein the band (9) can be destroyed by an actuator on demand.

9. Vehicle according to claim 6, wherein the band (9) is elastic and

expands during deployment of the airbag.