DE29917943U1 - Passenger gas bag restraint system - Google Patents

Description

PRINZ & PARTNERgJr

PATENT ATTORNEYS Manzingerweg 7

EUROPEAN PATENT ATTORNEYS D-81241 Munich

EUROPEAN TRADEMARK ATTORNEYS Tel. + 49 89 89 69 80

12 October 1999

TRW Occupant Restraint Systems GmbH & Co KG
Industriestrasse 20
D-73553 Alfdorf

Our reference: T 9164 DE

AI/sc
10

Passenger gas bag restraint system

The invention relates to a passenger gas bag restraint system, with a gas bag module comprising at least one gas generator, a front gas bag and a diffuser tube in which generated gas is distributed before entering the gas bag.
20

Such a gas bag module is known from EP 0 685 364 Bl.
The gas generator is inserted into the diffuser tube, and the diffuser tube has an open circumferential section at its ends, with the open area facing the driver.
25

This well-known restraint system has the disadvantage that it is relatively wide in the direction of travel, which makes it difficult to accommodate in the vehicle.

Other known restraint systems, even those with a diffuser tube, have the disadvantage that occupants who are not seated correctly, i.e. occupants in the so-called out-of-position situation, can be hit with relatively great force or can be poorly restrained by the gas bag which unfolds in a cone shape towards the occupant.

In addition, the large and bulky modular flaps that are common today pose a certain risk when they are swung open or removed.

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The invention creates a passenger gas bag restraint system that can be more easily accommodated in the vehicle and offers a higher restraint potential with a lower risk of injury, especially for passengers who are not sitting correctly.

This is achieved in a restraint system of the type mentioned above in that the diffuser tube has gas guide channels in the area of its axial ends on the tube wall that are directed diagonally outwards towards the associated end and diagonally towards the occupant, with the diffuser tube preferably being arranged essentially transversely to the longitudinal direction of the vehicle. With the diffuser tube designed in this way, the gas flow is not directed directly towards the occupant, but rather laterally past him. Gas flows are created which overall form a V-shape, between the sides of which the occupant is positioned. The individual gas flows are directed laterally towards the edge of the gas bag so that it inflates directly transversely to the direction of travel. The direct and immediate impact of the gas bag and the gas flow on the occupant in an out-of-position situation is thus reduced. On the other hand, the speed at which the gas bag is deployed is not reduced too much, as would be the case if the gas could only escape from the front sides of the diffuser tube.

The channels can be formed by oblique holes or by shell-shaped deflectors. These deflectors can be separate parts or special deformations of the diffuser tube.

The gas generator can be located inside or, as is also possible, outside the diffuser tube. In the latter case, a line is provided that connects the gas generator to the interior of the diffuser tube.

The gas generator is preferably an elongated body arranged parallel to the elongated diffuser tube. In addition, according to the preferred embodiment, the diffuser tube extends over the entire width of the gas bag at its module-side fastening.

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In contrast to the known driver gas bag modules, which form a relatively bulky and thick unit, the restraint system according to the invention has a module that is elongated and very narrow. This means that the module flap can also have small dimensions and, when opened, only protrudes slightly towards the interior of the vehicle.

It is also beneficial for this purpose if the gas bag, when folded, only has folds that run parallel to the longitudinal direction of the diffuser tube, i.e. it has no so-called folds on its side edges.

The gas bag can be folded in a zigzag shape as a package and can be connected to the diffuser so that together with the diffuser tube it forms an elongated, wider but low-height unit. In addition, it is also proposed to divide the gas bag into two folded sections. The folded sections are then arranged in two packages on opposite sides of the diffuser tube. This results in an elongated unit made up of diffuser tube and folded gas bag that is smaller in width but higher in height than with the previously mentioned zigzag folding with a package.

Preferably, the diffuser tube and the gas bag extend in the folded state over the entire width of the gas bag module, which in turn should essentially have the width of the seat or even extend over the entire passenger side transversely to the direction of travel.

The diffuser tube is advantageously closed at the front so that only the gas guide channels directed diagonally outwards act and direct the gas.

Further features and advantages of the invention will become apparent from the following description and from the following drawings, to which reference is made. In the drawings:

Figure 1 is a plan view of an embodiment of the passenger gas bag restraint system according to the invention,

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Figure 2 shows the restraint system shown in Figure 1 in the installed state, with the gas generator not yet activated,

Figure 3 shows the restraint system shown in Figure 2 during the unfolding of the gas bag, with the gas bag shown in different stages of expansion,

Figure 4 is a longitudinal sectional view through a vehicle in the area of the dashboard on the passenger side, showing the restraint system according to the invention in the installed state,

Figure 5 shows the gas bag module as part of the restraint system according to the invention according to a first embodiment, in a view from above,
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Figure 6 is a view of the gas bag module shown in Figure 5 from the front and without the gas bag,

Figure 7 shows a section along the line VII-VII of the module in Figure 6, again shown without gas bag,

Figure 8 is a plan view of the gas bag module according to a second embodiment,

Figure 9 is a front view of the gas bag module shown in Figure 8 without gas bag,

Figure 10 is a sectional view of the gas bag module along the line XX in Figure 9, again shown without gas bag,
30

Figure 11 is a cross-sectional view through the module showing a possible variant of folding the gas bag, and

Figure 12 is a cross-sectional view through the module showing another variant of folding the gas bag.

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Figure 1 shows a passenger airbag rear hall system in the form of an airbag module 10. The airbag module 10 consists of, among other things, a front airbag 12, a diffuser tube 14 inserted into the side of the airbag 12 and two gas generators 16, 18, which are connected to the interior of the diffuser tube via lines 20 and 22 respectively. The broken line 24 symbolizes the unfolded airbag. A housing enclosing the above-mentioned parts or a film enclosing the parts is not shown.

The module is elongated and, as shown in Figure 2, extends over almost the entire width of the seat 26. The instrument panel in which the module 10 is housed is shown at 28. Figure 2 also shows that the elongated diffuser tube 14 runs transversely to the direction of travel and otherwise horizontally. The two gas generators 16, 18 are arranged coaxially one behind the other and parallel to the diffuser tube 14. Shell-shaped housings 30 surround and form the lines 20, 22 and connect the diffuser tube 14 to the gas generators 16, 18.

The gas bag 12 has only folds that extend parallel to the diffuser tube 14, i.e. it has no inwardly folded edges at its lateral ends shown in Figures 1 and 2. This means that the gas bag only has the dimensions shown in Figure 1, even in plan view and transversely to the vehicle's longitudinal direction X. The diffuser tube 14 thus extends over the entire width of the gas bag 12 and even beyond. It has axially flattened ends 34 formed by pressing together, which serve as fastening flanges. The diffuser tube 14 is thus closed at the front.

The diffuser tube extends over the entire width of the gas bag module 10.

The module is therefore very long, but, as shown in Figure 4, not too wide. Above all, it is extremely low in height. The module also preferably has an outer housing 36 in which the gas bag, diffuser tube and gas generators are housed. An elongated, low-height flap 38 forms the front end of the module and prevents any

trilt opening. In the swung-away state, which is shown in Figure 4, the flap only projects slightly towards the occupant. 40 represents a knee-length, i.e. large-area cushion that begins immediately below the gas bag module 10. The broken lines 24 show several phases of the unfolding gas bag.

Figure 5 shows the gas bag module without the housing, slightly enlarged, and also shows the lines 20 and 22 housed in the housing 36. The two gas generators are facing each other with the axial ends that have the outflow openings 42, so that only one housing 30 is necessary to hold both generators and to ensure a flow connection to the diffuser tube 14.

The special design of the diffuser tube 14 can be seen better in Figures 6 and 7. The diffuser tube has only outlet openings near its axial ends, which are formed by gas guide channels 50. The gas guide channels 50 are in turn created by cutting the diffuser tube 14 open in sections in the circumferential direction and shaping the tube wall radially inwards and into a trough shape, so that shell-shaped deflection devices 52 are created. The gas guide channels 50 are thus formed by these shell-shaped deflection devices 52 in conjunction with adjacent shell-shaped deflection devices 52 and by the wall of the tube 14.

The gas guide channels 50 provided at the right axial end of the diffuser tube 14 are directed obliquely outwards towards their associated end and also obliquely towards the occupant when the module 10 is installed. The left gas guide channels 50, in turn, are directed outwards to the left, i.e. obliquely outwards towards their associated end and obliquely towards the occupant. The gas guide channels 50 at both ends thus produce V-shaped flows when inflated, as can be seen in Figure 3.

This has the effect that the gas bag is inflated first in the area of its edges, as seen from above, and not

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unfolds in a conical shape towards the occupants. The entire width of the gas bag is therefore available at a very early stage of the unfolding process. The force with which the gas bag hits an occupant 100 who is too far forward (see Fig. 3) is therefore less than with conventional restraint systems^

Figures 8 to 10 show an embodiment in which the two gas generators 16, 18 have been inserted from the end cables into the interior of the diffuser tube 14. A profiled center piece 70 serves to hold and center the gas generators 16,

18. The diffuser tube 14 has a gap 72 on the inside to the outside of the gas generators 16, 18, in which the gas can be distributed before it flows into the gas bag via the gas guide channels 150 at an angle outwards. In the embodiment shown in Figures 8 to 10, the shell-shaped deflection devices 152 are formed by separate parts placed on the outer surface of the diffuser tube 14. The gas guide channels 150 are in turn formed by the deflection devices 152 and also the tube wall.

In this embodiment, the diffuser tube 114 is also closed at the front. Bolts 74 projecting radially from the diffuser tube serve for fastening.

Figures 11 and 12 show various possibilities for accommodating the gas bag 12 together with the diffuser tube 14 in the module in a space-saving manner. In both embodiments, the diffuser tube 14 is inserted into the side of the gas bag 12 and the gas bag lies directly against the diffuser tube 14.

In the embodiment shown in Figure 11, the gas bag 12 is folded in a zigzag shape to form a package 76 which has the width of the gas guide tube 14 and extends in the unfolding direction Y. This means that the unit consisting of the diffuser tube 14 and the gas bag 12 provides a gas bag module which has a low height when installed (see Figure 4).

In the embodiment shown in Figure 12, the gas bag 12 is folded into two packages 78 and 80 of approximately the same size, each of which corresponds to a folded section of the gas bag and adjoins the diffuser tube 14 on opposite sides. The gas guide channels direct the gas forwards in the direction Y. This embodiment results in a gas bag module which, when installed, has a smaller width but a greater height compared to the embodiment shown in Figure 11.

Furthermore, not only can two separately ignitable generators be used, as is the case in the embodiments shown, which replace a two-stage gas generator, but a single gas generator can also be used.

It should be emphasized that the various ideas, such as directing the gas away from the occupant in a V-shape rather than directly onto him, the folding and extension of the gas bag in the folded state, the arrangement of the diffuser tube and the arrangement of the gas generators in relation to the diffuser tube, do indeed lead to a synergistic effect, but that these features alone already have considerable advantages and do not necessarily have to be implemented in conjunction with the other features.

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Claims (15)

1. Passenger gas bag restraint system, with
a gas bag module ( 10 ) made of
at least one gas generator ( 16 , 18 ),
a front gas bag ( 12 ) and
a diffuser tube ( 14 ) in which generated gas is distributed before entering the gas bag ( 12 ), characterized in that the diffuser tube ( 14 ) has gas guide channels in the region of its axial ends on the tube wall which are directed obliquely outwards towards the associated axial end and obliquely away from the occupant. 2. Passenger gas bag restraint system according to claim 1, characterized in that the gas guide channels are formed by shell-shaped deflection devices ( 52 ; 152 ) on the tube wall. 3. Passenger gas bag restraint system according to claim 1 or 2, characterized in that the gas generator ( 16 , 18 ) is arranged outside the diffuser tube ( 14 ) and is connected to the interior of the diffuser tube ( 14 ) via a line ( 20 , 22 ). 4. Passenger gas bag restraint system according to claim 3, characterized in that the gas generator ( 16 , 18 ) is an elongated body arranged parallel to the elongated diffuser tube ( 14 ). 5. Passenger gas bag restraint system according to one of the preceding claims, characterized in that the diffuser tube ( 14 ) extends over substantially the entire width of the gas bag ( 12 ) at its module-side fastening end. 6. Passenger gas bag restraint system according to one of the preceding claims, characterized in that the gas bag in the folded state has folds running exclusively parallel to the longitudinal extension of the diffuser tube ( 14 ). 7. Passenger gas bag restraint system according to one of the preceding claims, characterized in that the gas bag ( 12 ) is folded in a zigzag shape. 8. Passenger gas bag restraint system according to one of the preceding claims, characterized in that the gas bag in the folded state has two sections, each of which is folded into a folded package ( 78 , 80 ) and is arranged on opposite sides of the diffuser tube ( 14 ). 9. Passenger gas bag restraint system according to one of the preceding claims, characterized in that the diffuser tube ( 14 ) extends in the folded state over the entire width of the gas bag module ( 10 ). 10. Passenger gas bag restraint system according to one of the preceding claims, characterized in that the gas bag ( 12 ) in the folded state extends across approximately the width of the seat transversely to the occupant. 11. Passenger gas bag restraint system according to one of the preceding claims, characterized in that the diffuser tube ( 14 ) is closed at the front. 12. Passenger gas bag restraint system according to one of the preceding claims, characterized in that two gas generators ( 16 , 18 ) arranged one behind the other and coaxially to one another are provided. 13. Passenger gas bag restraint system according to one of the preceding claims, characterized in that the diffuser tube ( 14 ) is compressed at its axial ends. 14. Passenger gas bag restraint system according to claim 13, characterized in that the diffuser tube ( 14 ) is arranged in the interior of the gas bag ( 12 ) and projects laterally from the gas bag ( 12 ) with the compressed ends ( 34 ). 15. Passenger gas bag restraint system according to one of the preceding claims, characterized in that the diffuser tube ( 14 ) is arranged substantially transversely to the vehicle longitudinal direction (X).