Vehicle seat and side airbag arrangement
Description
Technical field of the invention
The invention relates to a vehicle seat according to the preamble of Claim 1 and to a side airbag arrangement for mounting in a vehicle seat according to Claim 11.
In order to protect the thorax of a vehicle occupant in the event of a side impact accident, so-called side airbag arrangements are known, which are arranged in the backrest of the vehicle seat or in the side structure of the vehicle and which have at least one airbag which inflates between the thorax area of the occupant and the side structure of the vehicle. Some vehicles also have a so-called curtain airbag, which in the event of a side impact inflates in the area of the side window and which serves in particular to protect the head of the occupant.
Side airbag arrangements with a relatively large-area side airbag are also known, which extends up to the height of the head of the occupant and thus also serves to protect the head. In this case the corresponding side airbag needs a relatively large amount of space between the backrest and the side structure in order to be able to deploy correctly, so that such side airbag arrangements are often not suitable for use in small vehicles.
Prior art
The generic DE 196 46 698 A1 discloses a vehicle seat with a side airbag arrangement, in which the side airbag has two protection chambers, with a first protection chamber being assigned to the thorax area and a second protection chamber being assigned to the head area of the occupant to be protected. In a first embodiment, the two protection chambers are filled by separate gas generators, in a second embodiment only one gas generator is provided which
fills the first protection chamber, with an overflow opening being provided between the two protection chambers so that the second protection chamber is filled via the first protection chamber. In both cases the side airbag - that is, the two protection chambers - is solely fixed to the back area of the backrest so that the second protection chamber extends upwards from its top mounting point when inflated, in order to reach the height of the head. With this side airbag arrangement too, a relatively large amount of space is needed between the backrest of the vehicle seat and the side structure of the vehicle in order to ensure unhindered deployment of the side airbag.
DE 196 37 603 A1 discloses a similar side airbag device in which a single gas generator is provided which inflates two completely separate airbags via a gas duct system, with one airbag being accommodated at thorax height and a second airbag being accommodated at shoulder height in the back area of the backrest. The disadvantage of this is in particular a relatively high outlay on production and/or assembly. With regard to the space required between the backrest and the side structure, this side airbag device has no advantages compared to those proposed in DE 19646 698 A1.
Summary of the invention
Proceeding from this, the object of the present invention is to create a generic vehicle seat with a side airbag arrangement arranged in or on the backrest, which is suitable in particular for use in small and economical vehicles.
This object is achieved by a vehicle seat with the features of Claim 1.
As there is often no curtain airbag provided in small, economical and light vehicles, the safety of an occupant in the event of a side impact can be greatly increased in that a side airbag arrangement which is present in the vehicle seat protects the head area of the said occupant in addition to the thorax area of the occupant. In conventionally arranged side airbags, the area or chamber of the
side airbag which is intended to protect the head must expand upwards to do this, and pass the shoulder area in doing this.
According to the invention two protection chambers are provided, with a first protection chamber being allocated to the thorax area and a second protection chamber being allocated to the head area, wherein the two protection chambers are connected by a filling section which extends in a rear area inside or along the backrest, and wherein the second protection chamber is arranged at head height on the backrest so that it does not have to expand upwards to the head height on expansion, and thus the shoulder area of the occupant does not constitute a constriction.
A side airbag arrangement which is provided for mounting in such a vehicle seat is specified in Claim 11.
Preferred embodiments of the invention are defined in the sub-claims as well as in the embodiments which are described in more detail with reference to the figures. In the figures,
Brief description of the drawings
Figure 1 shows the components of a side airbag arrangement,
Figure 2 shows a side airbag arrangement which is produced from the components shown in Figure 1 , Figure 2a shows what is shown in Figure 2 in the packed state,
Figure 3 shows a side view of a vehicle seat in which the side airbag arrangement of Figure 2 is mounted, in a schematic illustration, Figure 4 shows a plan view from direction R of what is shown in Figure 3, likewise in a schematic illustration, Figure 5 shows a section along plane A-A of Figure 3,
Figure 6 shows what is shown in Figure 3 with the side airbag expanded, Figure 7 shows a second protection chamber in an alternative embodiment and
- A -
Figure 8 shows a second embodiment of the invention.
Detailed description of preferred embodiments
Figure 1 shows the components of an airbag arrangement. These comprise a cutting 10 for an airbag, a gas generator 40 with mounting bolts 42 and an ignition cable 45, a deflector 44, a mounting tab 35 and a tether 36.
The cutting 10 for the airbag is symmetrical along a folding line 16 and essentially "butterfly-shaped". The cutting 10 has three section, namely the upper section 12, the lower section 14 and the centre section 15 which connects the upper section 12 and the lower section 14 to each other. The centre section 15 is much narrower than the upper section 12 and the lower section 14. Two mounting holes 18 and a cable passage opening 19 are provided on the folding line 16 in the lower section 14 so that the gas generator 40 can be arranged inside the side airbag 5 which is produced from the cutting 10. Here, the mounting bolts 42 of the gas generator 40 pass through the mounting holes 18 and the ignition cable 45 passes through the cable passage opening 19.
Figure 2 shows a side airbag arrangement which is assembled from the components shown in Figure 1 in a side view. When assembled, the side airbag 5 is closed by means of the edge seam 20, with which the tether 36 and the mounting tab 36 are fixed at the same time. A connection line in the form of a connection seam 22, which connects the two side walls of the airbag is then arranged in the area of the head. The gas generator is subsequently inserted into the interior of the airbag 6, for which purpose a further opening can be provided. This is not shown here as it does not contribute anything to the understanding of the invention. In the fully assembled state the mounting bolts 42 of the gas generator 40 extend through the mounting holes 18 and through bores in the deflector 44, and the ignition cable 45 is guided through the cable passage opening 19.
After the sewing process is complete, the side airbag 5 has a first protection chamber 30, which is produced from the lower section 14 of the cutting, a second protection chamber 32, which is produced from the upper section 12, and a filling hose 34 which forms the filling section and connects the first protection chamber 30 and the second protection chamber 32 to each other and is produced from the centre section 15 of the cutting 10. The filling section extends along the rear edge of the airbag 5 which is formed by the folding line 16 in the embodiment shown. The tether 36 connects the first protection chamber 30 and the second protection chamber 32 in a front section so that a free space F remains between the filling hose 34 and the tether 36. The mounting tab 35 is situated on an upper, rear point of the second protection chamber 32. The side airbag arrangement is fixed to the backrest of a motor vehicle seat by means of the mounting bolts 42 and the mounting tab 35.
Before the side airbag arrangement is mounted in a vehicle seat, the side airbag 5 is rolled or folded only along direction B and the two protection chambers 30, 32 are held by means of at least one sheath element 38 consisting of a flexible material (see Figure 2a). Direction B runs essentially perpendicularly to the filling hose 34 and is furthermore essentially parallel to the connection seam 22. The sheath elements 38 can in particular consist of fabric and have a predefined breaking line (not shown), along which the sheath element tears open when the airbag deploys. In the embodiment shown, such a sheath element 38 is provided for each protection chamber, but a continuous sheath element for both protection chambers or a plurality of narrow bands for each chamber could also for example be provided.
Figure 3 shows the side airbag arrangement 5 from Figure 2a in the mounted state in the backrest 52 of a vehicle seat 50 in a highly schematised side view. The side airbag arrangement 5 is generally situated completely inside the backrest 52 of the vehicle 50 so that it is "in reality" not visible from the outside. Figure 4 shows a plan view from direction R of what is shown in Figure 3, with non-visible components also being shown.
The vehicle seat 50 has a sitting surface 51 and a backrest 52. The backrest 52 has a back area 54 and a head rest 56 which is integrally formed with the back area 54. The backrest tapers in a transitional section between the back area and the head rest. The upper mounting means, that is, the mounting tab 35 which is allocated to the second protection chamber, is situated in this transitional section or above it. The connection of the mounting means - that is the mounting tab 35 - to the described area of the backrest is rigid. That means that the mounting means has the same position in the resting state and in the deployed state of the second protection chamber 32. A continuous backrest frame 60 is provided which forms the supporting structure for both the back area 54 and the head rest 56. This backrest frame 60 also bears the above-described side airbag arrangement. It can be seen in Figure 3 that the first protection chamber 30 is situated completely in the back area 54, approximately at the height of the side cheek 58, and the second protection chamber 32 is situated completely inside the head rest 56. The filling hose 34 extends in the intermediate area between the back area 54 and the head rest 56, that is, at the height of the shoulder of an average occupant sitting in the vehicle seat 50.
Figure 5 shows how the gas generator 40 is connected via a mounting plate 46 to the backrest frame 60. The mounting tab 35 can be held directly on the backrest frame 60 approximately at the height of the head of an occupant of average size sitting in the seat.
Figure 6 shows what is shown in Figure 3 but with the airbag deployed. The deployment direction is direction -B; the deployment therefore only takes place in exactly one direction which points forward. Since the connection line (connection seam 22) in the second protection chamber extends parallel to the deployment direction it does not hinder the filling of the second protection chamber 32. Neither of the two protection chambers needs to deploy at the height of the shoulder of the occupant to be protected - the free space F is here - so that this area does not form a constriction. Because of the mounting tab 35, which forms the mounting means of the second protection chamber 32 and which is connected to the vehicle seat in the head area, the second protection chamber 32 has very
good lateral stability and can hold the head of the occupant even when there is no supporting face at the height of the second protection chamber 32 due to the side window being wound down. The stability is further improved by the tether and the connection seam 22.
Figure 7 shows an alternative configuration of the second protection chamber 32 in which the mounting tab 35 is integrally formed on the cutting 10.
In the preferred embodiment shown only one airbag is present which has the two protection chambers and the filling hose. This is preferred because weight and production costs can be reduced in this manner but is not indispensible for the fundamental function. Producing the airbag from just one cutting also contributes to cost reduction but this is not absolutely necessary either.
Figure 8 shows a second embodiment of the invention. Here, the filling section is not formed in a hose-like manner as in the first embodiment but is a transitional area 37 with an essentially triangular shape which extends adjacently to the rear edge of the airbag and connects to the first protection chamber 30 and widens towards the second protection chamber 32 into which it continuously merges. As the second protection chamber 32 is not filled essentially horizontally as in the first embodiment but diagonally upwards, the connection seam 22 is not arranged essentially horizontally either but running diagonally upwards. The upper connection of the airbag 5 takes place in this case between the transitional area 37 and the second protection chamber by means of the mounting tab 35 which is arranged on the rear edge of the airbag 5. As in the first embodiment, the connection between the mounting tab 35 (the mounting means) and the backrest is rigid in a sense that the position of the mounting tab 35 is the same in the resting state and in the deployed state of the second protection chamber 32. Usually the mounting tab 35 is fastened to the backrest frame 60. As in the first embodiment, a free space F is provided between the first protection chamber and the second protection chamber. This free space has an essentially triangular shape and opens from the rear forwards. An occupant of average height is also
sketched in Figure 8. It can be seen that the free space is situated in the shoulder area. This is also the case for the first embodiment.
List of reference symbols
5 airbag
10 cutting
12 Upper section
14 Lower section
15 Centre section
16 Folding line
18 Mounting holes
19 Cable passage opening
20 Edge seam
22 Connection seam
30 First protection chamber
32 Second protection chamber
34 Filling hose
35 Mounting tab
37 Transitional area
36 Tether
38 sheath element
40 Gas generator
42 Mounting bolts
44 Deflector
46 mounting plate
45 Ignition cable
50 Vehicle seat
51 Sitting surface
52 Backrest
54 Back area
56 Head rest
58 Side cheek
60 Backrest frame
62 Lower section
64 Intermediate section
66 Upper section (head section)