DE19733599C2 - Method and device for protecting a vehicle occupant outside the normal position in the event of a crash - Google Patents

Description

The invention relates to a method and a device to protect one outside the normal position Vehicle occupants in the event of a crash according to the generic term of the An saying 1.

It is known to occupants of a motor vehicle in the event of a crash to protect with an airbag. An airbag module has a gas source from which in the event of a crash gas into the previous folded airbag occurs, whereby this is unfolded  and a protective cushion between a vehicle part such as that Steering wheel, the dashboard or a side door, and the Occupant forms.

A good protective effect is achieved when the occupant after the gas bag has fully unfolded bounces. This presupposes that the occupant has a normal posi tion occupies in the vehicle in which the upper body the seat back rests. The gas bag falls after the impact quickly collapse in itself by passing the gas through at least an opening in the airbag or through the airbag fabric in the Flows out of the passenger compartment. The cross-section of the outflow opening or the gas permeability of the airbag fabric is so chosen that for the in the normal position in the motor vehicle seated occupant who in the event of a crash after unfolding the Gas bags collide with them, a safe ride-down, d. that is, safe uptake in the collapsing gas sack is secured. The gas bag must hit the Occupants be so hard that punctures are avoided on the other hand, it shouldn't be that hard, that the occupant is injured by the impact on the gas bag becomes.

However, the airbag can become a source of danger for the Become inmates when they are "out of position" (oop) is located, d. that is, if he z. B. bends forward. In this position there is a risk that the occupant in the A crash occurs on the unfolding gas bag, d. H. that he was shot by the gas bag and as a result of occur the membrane forces are accelerated in the direction of deployment. The gas bag internal pressure increases in this case due to the  unchanged gas delivery rate of the generator and the now gas bag volume decreased an increased value on.

To eliminate this disadvantage, it is out of the US 54 05 166 A known, in the area of outflow openings Gas bags flexible parts by means of tear seams on the gas bag fasten. These parts also have openings and are folded in the area of the tear seams. The openings of the Gas bags and the flexible parts are aligned, as long as the tear seams are intact. The additional parts and the tear seams are dimensioned so that the gas bag is in a first development phase only up to a predetermined one Can spread length toward the occupant. If in during this development phase, an occupant from the Airbag can be shot over the above Gas openings flow out of the gas bag so that the gasin pressure does not continue to rise, causing the injury driving for the occupant is reduced.

If the airbag is not in its place by the occupant Unfolding are hampered as a result of increasing Pressure in the gas bag tore the tear seams, causing move the parts against the gas bag wall. Here the outflow openings in the gas bag are also closed, so that the fully deployed gas bag has sufficient interior shows pressure.

The disadvantage of this arrangement is that up to a defined deployment state of the gas bag constantly Gas escaping through the aligned openings  can. The associated delayed release of the gas sackes negatively affects the protection of an occupant Normal position.

From the generic DE 41 21 659 A1 is an impact protection device known to vehicle occupants at the top of the gas generator in the airbag a flap or bubble-shaped cover as Heat protection and to control the airbag deployment provided hen is. The reaction gases can laterally and / or in Direction of the occupant through appropriately dimensioned Openings in the cover enter the airbag, causing the airbag primarily during the deployment process expands laterally, or its rate of expansion is reduced in the passenger direction. This will cause the in Expansion of the airbag in the direction of the occupant reduced so that the risk of contact between the Reduce occupants and the airbag during the deployment phase is gert.

The disadvantage of this device is that the Internal pressure cannot be influenced during the development phase is so that when an occupant hits the airbag in In this phase the risk of injury is hardly reduced.

DE 40 22 420 A1 describes an airbag in a passive one Retention device known in which the internal pressure of the deployed air bags regardless of the ambient temperature is kept at an almost constant value. The  is made of heat shrinkable material in the area of Ab gas outlet reached. After ignition of the gas generator this material shrinks and gives the exhaust outlet in Depending on the temperature of the reaction gas free. There this temperature changes with the ambient temperature the material is at a high ambient temperature shrink quickly and strongly so that the exhaust outlet is wide is opened. In contrast, the material at low ambient temperature slower and less strong shrink so that the exhaust outlet is less open becomes. This creates different amounts of exhaust gas derived.

This arrangement is not suitable for an exhaust opening depending on the seating position of the occupant other.

From US 54 78 111 A and US 55 18 269 A are airbag arrangement known in which at least one additional Ab flow opening in the gas bag is provided with a cover, the below a critical internal pressure in the gas bag in small for those emerging from the gas generator is permeable to hot gases. Above a critical one Pressure, which varies depending on the Ambient temperature, the severity of the accident or the occupant dimensions se sets, the cover melts by the action of are called gases, so that a stronger outflow through the Ab flow opening is possible. Also capture these orders not the seating position of the occupant to regulate the out the gas stream emerging from the gas bag.

The invention is therefore based on the object Risk of injury to an out of position Occupants, while maintaining full protection for an occupant in the normal position.

According to the invention that is according to the features of the claim 1 reached.

In a procedure to protect an out of normal position vehicle occupants (oop case) in the Crash case, protection by an airbag module with a Airbag takes place, which is deployed by hot compressed gas, the compressed gas directly or with interposition a diffuser flows into the gas bag, and wherein between the compressed gas source and the gas bag at least partially se a flame retardant is provided according to the invention Impact of the occupant on the still unfolding phase of the gas bag that is flowing into the gas bag hot compressed gas on at least one point of the gas bag passed, on which the gas bag has no flame retardant and can be destroyed by the hot compressed gas, so that at this point in the gas bag due to the hot compressed gas additional opening for the increased gas outlet in the oop case is generated.

In this method according to the invention, the for the increased gas leakage required in the event of an oop Openings only in the oop case even through those from the gas gene exiting hot gases. Therefore have to  these openings in the manufacture of the gas bag are not be provided. In the event that the gas bag can unfold unhindered by the occupant Openings not created.  

In one embodiment, the gas bag stretching in the intended intended impact area of the occupant, and for the case that the airbag extension towards the occupant has not yet ended when it hits the gas bag, becomes a movable flame retardant with at least one Opening for the passage of the hot compressed gas so posi that the opening in front of the flame retardant point of the gas bag. By the bouncing occupant ver the further expansion of the airbag in its direction prevents. The opening remains in the area of the flame unprotected area of the gas bag and this is through there the hot gases destroyed. Through the opening formed in the The gas bag can flow out of the hot gas.

In the event that the occupant is in his normal position and that the gas bag is therefore unobstructed can unfold, is the length of time with the opening provided section of the movable flame retardant against over the flame-retardant point of the gas bag so short that the gas bag does not burn.

The gas bag is preferably located in the inlet area of the hot compressed gas destroyed.

A device to protect an out of the normal posi tion vehicle occupants in the event of a crash, under Use of an airbag module with an airbag, a Gas generator and a diffuser is there according to the invention characterized in that at least one deals with the The gas bag unfolding flame protection tape is provided in the gas bag and that the flame retardant tape has at least one opening  for the passage of the exiting from the gas generator Gas towards a flame retardant point of the gas Sacks has, so that at this point in the gas bag the hot compressed gas an additional opening for the ver strong gas leakage is generated in the oop case.

It is appropriate that one end of the flame retardant tape in the loading rich of the gas generator or diffuser is attached and is gathered or folded there that this position by means of at least one tear seam is fixed that the opening over the tear seam is provided in the flame retardant tape and that other end of the flame retardant tape on the occupant facing side of the gas bag is attached, the Flame retardant tape has a length that corresponds to the expansion of the fully deployed gas bags towards the occupant corresponds and where it ver at a distance from the gas bag wall running.

If an occupant out of position the spread direction of the gas bag in its direction, that will Flame retardant tape fixed in position by the tear seams the opening of the flame retardant tape of the flame retardant Place of the gas bag is opposite, so that the gas bag this point is destroyed by the hot gases. in the If the airbag is facing the occupant of this can spread unhindered, the tear seams torn open so that the flame retardant tape up to his full length can unfold. The opening of the sensor tape is then only briefly opposite the flamm  unprotected area of the gas bag that this is not through can burn. The hot gases then rather meet this flame-retardant point of the gas bag on the flame protective tape. This is also a sensor band, because the  opening in it depending on the cancellation the gas bag in front of the flame retardant point of the Gas bags is positioned.

In a further embodiment, at least two tears seams of different strength are provided. So that can be achieved that the opening after tearing one Tear seam only partially compared to the flame retardant Place lies so that the hot gas partly on the flame Protection of the gas bag strikes and partly on the flame unprotected area. This will make the gas bag smaller Extent destroyed, d. that is, the additional outflow opening smaller.

For further optimization of the device according to the invention the flame retardant tape can have several in the direction of the occupant Have openings of different sizes. It takes the size of the openings in the direction of the occupant is appropriate from. The largest opening is the still slightly unfolded Assigned airbag. During this phase the gas pressure in the Gas bag and thus the membrane forces still strong, so that a great one for the sudden reduction of the airbag pressure Opening is required. In later stages of development the pressure increase is less, so that a smaller opening is sufficient to protect the occupant from injury.

In a further embodiment, the flame retardant tape Made in several parts, at least in sections, each part has at least one opening, each of which is a flame unprotected location on the airbag is assigned and one end each part is in different places of the Insas attached to the opposite side of the gas bag.  

The size and shape of the opening burned into the gas bag is not only by the size but also by the shape of the openings of the flame retardant tape can be influenced. Those are preferred Openings rectangular, triangular or circular.

The invention is intended to be used in exemplary embodiments on the basis of Drawings are explained. Show it:

Fig. 1 shows a section through the lower part of an air bagmoduls;

FIG. 2 shows the airbag module according to FIG. 1 in an early deployment phase of the gas bag;

. FIG. 3 shows the airbag module of Figure 1 in a later stage of deployment of the airbag;

. Fig. 4, the airbag module of Figure 1 with fully deploying airbag system;

Fig. 5-7 different forms of openings in a flame retardant tape;

Fig. 8 is a gas bag with a multi-part flame protection tape.

In Fig. 1 a section of an airbag 1 is Darge, which is fixed in a housing 2 of an airbag module. In the airbag 1 there is a gas generator (not shown) with a diffuser 3 , which has openings 5 at its chimney-like area 4 projecting into the folding space for the escape of the gases generated in the gas generator. In the region of the openings 5 of the diffuser 3, the gas bag 1 has, in a known manner, a flame retardant 6 which is firmly connected to the gas bag 1 and which is interrupted at a point 7 . Furthermore, a flame retardant tape 8 is provided, which is attached at one end 8 a in the area of the gas generator. The flame retardant tape 8 is folded next to the gas generator and the folded position is secured by tear seams 9 . Above the folds, the flame retardant tape 8 has an opening 10 in the area of the diffuser 3 . This opening 10 is in the folded position and when the gas bag 1 is deployed until the friction seams 9 tear, the flame-proof location 7 of the gas bag 1 is opposite.

As can be seen from FIG. 2, the other end 8 b of the flame retardant band 8 is connected to the part of the gas bag 1 which is facing the occupant. At the beginning of Entfal processing of the airbag 1, the portion facing the occupant of the flame retardant belt 8 due to the fixed end 8 b drawn from the deploying airbag 1 toward the occupant. The stitched by the tear seams 9 folded portion of the flame retardant tape 8 does not change its position initially. Even when the airbag 1 unfolds further, this folded section does not change its position, as can be seen from FIG. 3. If at this point in time the head 12 of an occupant out of position is shot through the airbag 1 , it can initially no longer spread in its direction, but rather unfolds laterally from the occupant, as can be seen from FIG. 3. This interruption of the unfolding process in the direction of the occupant is sufficient to destroy the gas bag 1 through the opening 10 at the flame-retardant point 7 by the hot gas jet 11 . As a result, the internal pressure in the airbag and thus the dangerous membrane forces are abruptly reduced, so that the body parts of the occupant are no longer accelerated.

However, if the occupant is in a normal sitting position, in which the upper body lies against the seat back, the airbag 1 can unfold freely. The residence time of the opening 10 of the flame retardant strip 8 is then not sufficient to destroy the gas bag 1 at the point 7 free of flame retardant. In the fully deployed position of the airbag 1 (Fig. 4) in which the flame retardant tape is also deployed 8 after tearing of the tear seams 9, is situated the opening 10 of the flame retardant tape 8 from the gas jet 11 in the gas sack 1. The gas jet 11 now strikes in the area of the flame-retardant point 7 of the gas bag 1 on the flame retardant band 8 , so that the burning of the gas bag 1 is avoided. The gas bag 1 can thus fulfill its normal protective effect.

Due to the size and shape of the opening 10 in the flame retardant band 8 , the size and shape of the location of the gas bag 1 to be destroyed by the hot gases 11 can be influenced. In Figs. 5 to 7 are three different execution forms of the aperture 10 is shown. In Fig. 5, the opening 10 consists of several small openings 10 a, the three are grouped in a corner. Fig. 6 shows a single triangular opening 10 b and FIG. 7 c a rechteckförmi ge opening 10.

In the embodiment shown in Fig. 8 with a multi-part flame retardant tape 13 , this from sections 13 a, b, c, which are perpendicular to the plane of the drawing next to each other and at different distances from the diffuser 3 openings 14 a, 14 b and 14 c . These adjacent openings 14 a-c are also associated with adjacent flame-free locations 7 on the airbag 1 , which are not shown in FIG. 8. The flame retardant tape 13 is folded in the rest position, as described in the exemplary embodiment in FIG. 1, the folded position being secured by three tear seams (not shown) of different strength. In this embodiment, the risk of injury in different intermediate positions of the occupant can be reduced even better than in the embodiment according to FIG. 1 by tearing the tear seams one after the other at different internal pressures and the gas bag 1 being destroyed at correspondingly different flame-retardant locations 7 . Depending on the state of deployment, the outflow cross-section necessary for the reduction in pressure is governed by the number of openings 14 a-c that are effective for the gas bag 1 to burn through.

Claims (10)

1. A method for protecting a vehicle occupant outside the normal position (oop case) in the event of a crash, the protection being provided by an airbag module with a gas bag which is deployed by hot pressure gas, the pressure gas being directly or with the interposition of a diffuser in the Gas bag flows in, and wherein flame protection is at least partially provided between the compressed gas source and the gas bag, characterized in that when the occupant collides with the gas bag ( 1 ) which is still in the deployment phase, the hot compressed gas ( 1 ) flowing into the gas bag ( 1 ) 11 ) to at least one point ( 7 ) of the gas bag ( 1 ) passes, at which it has no flame retardant ( 6 ) and can be destroyed by the hot compressed gas ( 11 ), so that at this point in the gas bag ( 1 ) the hot compressed gas ( 11 ) creates an additional opening for the increased gas outlet in the oop case. 2. The method according to claim 1, characterized in that the gas bag stretching in the intended Aufprallbe range of the occupant is detected, and that in the event that the gas bag stretching in the direction of the occupant is not finished when it hits the airbag ( 1 ) movable flame protection ( 8 , 13 ) with at least one opening ( 10 , 14 ) for the passage of the hot compressed gas ( 11 ) is posi tioned that the opening ( 10 , 14 ) in front of the flame retardant point ( 7 ) of the gas bag ( 1 ) lies. 3. The method according to claim 1 or 2, characterized in that the gas bag ( 1 ) in the inlet area of the hot compressed gas ( 11 ) is destroyed. 4. Device for protecting a vehicle occupant outside the normal position (oop case) in the event of a crash, using an airbag module with a gas bag, a gas generator and a diffuser, wherein a flame protection is at least partially provided between the compressed gas source and the gas bag, characterized in that at least one unfolding the gas bag (1) flame retardant tape (8, 13) is provided in the gas bag (1), and that the flame retardant tape (8, 13) at least one opening (10, 14) for the passage of the from the Gasgenera gate emerging gas ( 11 ) in the direction of a flame-resistant point ( 7 ) of the gas bag ( 1 ), so that at this point ( 7 ) in the gas bag ( 1 ) through the hot compressed gas ( 11 ) an additional opening for increased gas leakage in the oop case is generated. 5. The device according to claim 4, characterized gekennzei chnet that one end ( 8 a) of the flame retardant tape ( 8 ) in the area of the gas generator or diffuser ( 3 ) be fastened and gathered or folded there that this position by means of at least one tear seam ( 9 ) fi xed that the opening ( 10 ) over the tear seam ( 9 ) is provided in the flame retardant band ( 8 ) and that the other end ( 8 b) of the flame retardant band ( 8 ) on the side facing the occupant of the gas bag ( 1st ) is attached, the flame retardant band ( 8 ) having a length which corresponds to the extent of the fully deployed gas bag ( 1 ) in the direction of the occupant, and wherein it runs at a distance from the gas bag wall. 6. The device according to claim 5, characterized in that at least two tear seams ( 9 ) are provided Licher strength. 7. The device according to at least one of claims 4 to 6, characterized in that the flame retardant band ( 8 , 13 ) in the direction of the occupant has several openings ( 14 a-c) of different sizes. 8. The device according to claim 7, characterized in that the size of the openings ( 14 a-c) decreases in the direction of the occupant. 9. The device according to at least one of claims 4 to 8, characterized in that the flame retardant band ( 13 ) is at least partially made of several parts, that each part ( 13 a-c) has at least one opening ( 14 a-c) each of which has a flame retardant point ( 7 ) on the gas bag ( 1 ) is assigned and that one end of each part ( 13 a-c) is attached to different locations on the side of the gas bag ( 1 ) facing the occupant. 10. The device according to at least one of the preceding claims 4 to 9, characterized in that the openings are rectangular ( 10 c), triangular ( 10 b) or circular ( 10 a).