EP1159164A1

EP1159164A1 - Restraining device for people in a motor vehicle

Info

Publication number: EP1159164A1
Application number: EP00989924A
Authority: EP
Inventors: Thomas Wohllebe
Original assignee: Volkswagen AG
Current assignee: Volkswagen AG
Priority date: 1999-12-03
Filing date: 2000-11-30
Publication date: 2001-12-05
Also published as: WO2001040029A1; AU2670601A

Abstract

The invention relates to a restraining device for people. The inventive device is used in the passenger cell of a motor vehicle and is provided with at least one impact protection element and a releasing device that operates the impact protection element when there is an impact. The impact protection element is provided with at least one security cushion (9; 7'; 5') that is compressed when the releasing device is in the non-activated initial state. Said cushion can be released for expanding by means of the releasing device. According to the invention, the security cushion (9; 7'; 5') is enclosed in a sleeve (11; 8'; 6') when in the compressed state (9a). The sleeve (11; 8'; 6') releases the security cushion (9; 7'; 5') for expansion when the releasing device is in the active state.

Description

Passenger restraint for a motor vehicle

The present invention relates to a personal restraint device for the passenger compartment of a motor vehicle, with at least one impact protection element and a trigger device that actuates the impact protection element in the event of an impact. The invention further relates to a method for triggering personal restraint devices in a motor vehicle

Airbag systems are most widely used as occupant safety systems with impact protection elements. The actual impact protection element of such an airbag system is formed by a sack or a cushion which is acted upon by gas in the event of a collision by a generally pyrotechnic gas generator. The actuation, ie the gas filling the impact protection element takes place sufficiently quickly, so that in the event of a collision the impact of the sometimes violently accelerated occupants is considerably dampened. By installing such airbags in the steering wheel (driver airbag), in front of the front passenger seat and now also laterally in the fuselage and head area, there is a risk of serious injury Injuries caused by physical contact with the inner wall of the passenger compartment are significantly reduced

The advantage of the aforementioned airbag systems lies particularly in the reliable protection of the occupants in the event of an accident from the consequences of the primary impact, which in most cases releases the greatest impact energy. However, recent studies show that more than 20% of all accidents involve multiple collisions in which the primary impact is followed by one or more further collisions.These are generally weaker than the pnm collisions, but they still have a considerable risk potential for the occupants. However, the aforementioned airbag systems according to the prior art have practical effects once the impact protection element has been exposed to gas No more shock-absorbing effect This has the consequence that the vehicle occupants following collisions in a multiple collision are largely unprotected and there is therefore a high risk of injury from contact with hard components of the vehicle interior. This risk la t is only to a small extent by a soft Reduce the coating of hard objects, such as the steering wheel, because the shock-absorbing effect that can be achieved is relatively low

From the generic DE 195 45 263 A1, a personal restraint device as a safety device for the passenger compartment of a motor vehicle is already known, which has at least one impact protection element and a triggering device that actuates the impact protection element in the event of a collision, the impact protection element compressing at least one in the non-activated basic state of the triggering device Has security cushion which can be released by the release device for expansion

Specifically, the safety cushion is shown here in connection with a child seat, which has a body serving as a safety catch, which encloses a cavity into which a safety cushion is inserted and received in a compressed manner in the non-activated basic state of the personal restraint device in the event of an activation taking place in a crash situation the personal restraint device can expel this safety cushion through expansion that can be formed in the catch body during expansion and serve as impact protection for the child sitting in the child seat. An inflatable airbag can be embedded in the safety cushion, which can be acted upon with a gas when the person restraint device is activated and as a result, the force required for the safety cushion to emerge from the catching body can be applied. Alternatively, the activation of the safety cushion is also associated with the child seat by means of an information line possible belt tensioner system possible

A disadvantage of this structure, however, is that the safety cushion has to be installed by a worker while compressing the cushion, which is obviously labor-intensive and time-consuming. Such an assembly effort is necessary for the large-scale production of motor vehicles in connection with personal restraint devices for the passenger cell of a motor vehicle, however, is only slightly or not at all practical, since this leads to undesirable long assembly times, which in turn increases the assembly costs

Another disadvantage here is that after the airbag collapses, the cushion maintains its protective character, but it is relatively unstable and can possibly be printed away to the side. The use of this structure with a large-volume airbag, such as was required on the passenger side further cause the airbag with the surrounding cushion to drop after the gas has escaped from the airbag and the cushion may no longer be available in the area at risk of impact in the event of a further collision or collisions

A similar structure is also known from US Pat. No. 3,853,334, in which a plurality of cushion parts are arranged in a compressed state in the basic state in the area of a steering wheel hub. The hub cover holds the cushion parts in the compressed basic state here. In the event of an accident, a pressure fluid flows into the compressed cushion parts via a pressure line containing receiving space introduced to burst open the hub cover so that the upholstery parts can ooze out under expansion through a release. The upholstery parts are collected in an activated and expanded state together with the pressure fluid in a sack. Again, the complex assembly is disadvantageous, since the upholstery parts are part of the Assembly must be introduced under compression In addition, the structure with pressure fluid in connection with upholstery parts is relatively complex and therefore not very practical

Furthermore, it is known from DE 94 13 949 U1 to integrate a restraint system with a cushion and an airbag into a steering wheel hub. In the event of a collision, the airbag is triggered and the driver's primary impact on the steering wheel is steamed. For a secondary collision in which the airbag is not The damping is then more available via the large-volume cushion arranged in the steering wheel hub. The cushion is not pre-compressed here, so that the use of a large-volume cushion is necessary, which in turn requires a large installation depth, which is not regularly given in the steering wheel hub area inflate the airbag here around the cushion or through narrow channels through it, which can undesirably delay the inflation process as a whole

Another conventional structure of a personal restraint device with an airbag and a non-compressible safety cushion is also known from DE 297 16 534 U1. In the event of an accident, a first airbag is inflated, this airbag being shaped in such a way that between the surface of the safety cushion and After filling, an underside of the airbag has a space for another airbag, which is folded around the safety cushion in such a way that, after the ignition of a correspondingly assigned gas generator, the space is filled by the further airbag additional airbag thus serves as an extended impact cushion protection over the safety cushion. Such a structure is obviously complex and therefore not very practical

Furthermore, from DE 199 08 637 A1 an energy absorber is known which has an essentially gas-tight shell which surrounds a full material and is provided with at least one feed line which is connected to a vacuum source. By applying negative pressure in the event of a crash, a hard energy absorber becomes At the same time, the negative pressure ensures that the generally flexible shell of the energy absorber retains its shape even in the event of an impact load.A foam replacement in the interior and exterior of the vehicle is particularly suitable.This energy absorber can be used, for example, as a bumper, as a knee pad or possible as upholstery in the door / pillar area An expansion of the full material is not intended here

Furthermore, from DE 296 11 869 U1 an airbag module for motor vehicles in the lower region of a control panel of the motor vehicle is known, which has a knee protector plate designed as a load distribution plate, behind which an airbag is arranged folded. The airbag is activated in the event of a collision of the vehicle by activating a gas generator inflated When the airbag is inflated, the knee protector plate detaches from the control panel and is moved in the direction of the knee of an occupant of the vehicle. During the collision of the vehicle, the knee protector plate intercepts the occupant's knee through the resilient knee protector plate in front of the airbag and a hard impact on vehicle interior parts is avoided After the airbag is inflated during a pneumatic collision, the gas flows out of the airbag and the airbag collapses, so that the airbag is no longer available as an energy absorber in the event of a subsequent collision

Furthermore, an airbag module with the elements just described is also known from EP 0 891 901 A1, in which the knee protector plate of the airbag module is additionally made from flexible hard foam. After the gas has flowed out of the airbag after the pnm collision, the knee protector plate then acts as an energy absorber Impact of the knee on the knee protector plate if there is another collision after the PN collision. However, the knee's damping during the secondary impact is solely dependent on the energy absorption capacity of the knee protector plate, since the airbag is deflated during the secondary impact. The knee protector plate is effective when the Knee as a load distributor to increase the impact area The absorption capacity of the knee protector plate is limited

The object of the invention is to provide a personal restraint device for the passenger compartment of a motor vehicle, which is quick and easy to assemble, in particular in the context of large-scale production with little effort and time, and provides effective impact protection in the event of collisions

This object is achieved with the features of claim 1

According to claim 1, the safety cushion in the compressed state is enclosed in a sleeve, which releases the safety cushion in the activated state of the release device for expansion

Advantageously, the safety cushion is held together by the cover under mechanical pretension in the compressed state in a relatively small volume, so that the safety cushion can be installed at a predetermined location in a relatively simple and quick manner without the compression of the safety cushion during the Installation must be carried out by yourself. A particular advantage of this construction is that the safety cushion can be made available as a simple and quick-to-install pre-assembly module

In the compressed state, the safety cushion according to the invention has only a fraction of its expanded volume.This allows it to be quickly and inconspicuously integrated into the vehicle interior in a space-saving manner.When the triggering device responds, this safety cushion is preferably mechanically released so that it returns to its original, full volume in the relaxed state If an impact is again applied to this safety cushion from the outside, for example due to the impact of vehicle occupants in the event of a collision, the material is briefly compressed and thereby absorbs the impact energy.In any case, the force of the impact is damped far better than simply by a thin coating of hard surfaces In this way, an improved occupant protection against injury is already achieved Another special feature of the impact protection element lies in the fact that it consists of a material which can be compressed to a smaller volume by the action of external forces and which expands again to its original volume without the need for the supply of external energy. This is essential Difference to the known airbags, which have their shock-absorbing effect only once briefly after the gas is applied by the gas generator of the triggering device. In contrast, the impact protection element regenerates several times, if necessary, and without further activation from the outside

Due to the special, previously described ability of the safety cushion to automatically expand to its original volume due to the internal elasticity of its material, it has regained its full shock-absorbing property shortly after being subjected to an impact, for example after a passenger impact has been dampened The function of airbags is thus given several times in succession, so that occupant protection in the event of multiple collisions is significantly improved

The safety cushion is preferably designed as a foam cushion made of compressible foam, for example made of open-pore plastic foam. Such modern foam materials can be compressed to a particularly high degree and, even after a long period of time in this compressed state, reliably expand again to their original volume. The energy absorption capacity, i.e. the shock-absorbing effect, is Particularly good with open-pore foam The impact energy is essentially converted into flow friction of the pressed-out air, so that the foam itself is not permanently compressed, but regenerates within a short time due to its internal elasticity, ie it recovers its original volume and its full shock-absorbing capacity Effect is fully available again

Compared to the classic airbag, the expansion rate of foam cushions is lower, but in combination with fast airbags they offer very good protection against collision injuries in the event of secondary collisions occurring later. However, the use of safety cushions according to the invention is also conceivable in such areas of the vehicle interior , where the use of an airbag is not appropriate or experience has shown that the hazard potential is lower, for example because the impact energy is usually lower or there places with which occupants experience, in the event of an accident, only come into contact later

In a preferred embodiment, the safety cushion is enclosed in an easily destructible cover in the compressed state.This cover can be designed, for example, as a foal cover made of plastic film or as a net made of plastic.In the compressed state, the safety cushion is held together by the cover in a relatively small volume under mechanical pretension This mechanical pretension bursts the cover completely as soon as it is even injured at one point.Thanks to the use of easily destructible materials, for example a plastic film, which can absorb the holding forces well, but then tears completely in the event of slight damage, the safety cushion according to the invention can expand easily with appropriate release means, ie released for expansion by destroying the halyard. This achieves particularly good pretensioning of the cushion to a very small installation volume that the safety cushion, which is preferably made of plastic foam, is welded into the foal envelope during manufacture under vacuum

In order to safely tear or burst the cover of the safety cushion for the draw, it is advantageous that the release device has separating means for destroying the cover. This can be, for example, drivable cutting means such as mandrels, cutters, blades or the like, which cut or cover the cover when actuated by pricking, whereby a tearing point is formed, which leads to the further tearing of the casing and to the release of the safety cushion which protrudes under mechanical tension

The release agents can, for example, be mechanically accelerated, ie driven, by a pyrotechnically triggerable gas generator. Such gas generators have long been used reliably in vehicle safety devices, for example in belt tensioners and pyrotechnic safety switches. As an alternative to this mechanical drive of release agents, it is possible to thermally destroy the casing, by directing the hot gas outlet of the gas generator onto the sheath. The hot gas escaping causes the material of the sheath, for example the plastic film, to be locally melted or melted on, so that it bursts open again in the manner described above and releases the safety cushion for expansion A particularly advantageous integration of the safety cushions according to the invention into existing vehicle safety systems provides that the triggering device of the safety cushion can be actuated via an airbag which can be acted upon pyrotechnically. Such an airbag has a gas bag which, when triggered, is filled within a very short time by a pyrotechnic gas generator with the combustion gases then generated is and acts as a cushioning cushion for an impact.These systems have the advantages mentioned at the outset of being able to offer particularly effective impact protection very quickly in the event of a collision, but this is offset by the disadvantage that they only offer one-time impact protection.Here is the present embodiment of the invention and suggests that the safety cushion according to the invention is forcibly drawn when the airbag is activated. For this purpose, release agents are attached, for example, directly to the gas bag of the airbag Eight for mechanical severing of the aforementioned cover, which act on the cover when it is pressurized with gas. It is also conceivable to arrange movably mounted cutting edges, spikes or the like, which are displaced, ie driven, by the expanding airbag of the airbag against the cover

An alternative embodiment provides that the Heißgasaustπtt of the airbag gas generator is directed to the shell, so that when the airbag is activated, the hulie of the safety cushion according to the invention is thermally destroyed in the manner described above. This variant has the advantage, on the one hand, that none Additional moving parts are required. Another advantage is that the expansion of the foam cushion is supported or accelerated again by the escaping gas

The safety cushion according to the invention is preferably accommodated in the airbag housing. The combination with the airbag module provides particularly effective protection in the event of multiple collisions. The first impact, which as a rule is particularly hard, is absorbed by the airbag's airbag while simultaneously being triggered by For the airbag, the energy-absorbing effect of the safety cushions according to the invention for a subsequent impact in a multiple collision is already fully available.An arrangement of this type is particularly advantageous, for example, if the airbag in the airbag housing is attached to the steering wheel hub of a motor vehicle , as well as in the dashboard on the passenger side or in the rear and Side area of the interior is conceivable Appropriately, the security cushion is then attached under a removable cover, which is laterally pushed away or folded away or released from its anchoring in the draw. For example, the cover on the housing can be clipped so that it expands from the clipping when the safety cushion is expanded is drawn and printed away

To support the driver's airbag, for example, the safety cushion can be attached to the steering wheel hub of a motor vehicle. It is then expediently designed in the form of a ring or segment or as a flat, preferably round cushion, which is fastened, for example, to the baffle of the steering wheel and especially the Covers opening of the airbag

According to a further preferred embodiment, the restraint device is arranged in the leg area of a vehicle occupant in a motor vehicle and comprises at least one airbag, at least one gas generator for inflating the at least one airbag and a load distribution plate which is displaced towards the leg space by inflating the at least one airbag, wherein The at least one compressed cushion expands after the gas generator has been released. The compressed cushion is preferably arranged on the side of the load distribution plate facing away from the leg space, which is preferably elastically deformable. In the event of a correspondingly severe puncture collision, the gas generator is released and inflates the gas bag, which in turn inflates the load distribution plate moves towards the leg area in the motor vehicle interior After the airbag module has been released during the PN collision, the compressed cushion also expands. After the PN collision, the gas bag falls because of the escaping gas together and the expanded cushion can now absorb energy e.g. during one or more further collisions. When the cushion is compressed, it takes up very little space, so that the installation depth of the installation module increases insignificantly compared to an airbag module without a compressed cushion This does not affect the occupant's legroom

In principle, the airbag module can also contain several gas generators, e.g. to prolong the inflated condition of the gas bag during a primary impact in the event of a collision with a flexible obstacle. The load distribution plate can be held in the leg area of the vehicle, for example, by tether after the primary impact so that it a subsequent collision between the occupant's legs and rigid components in the knee impact area The load distribution plate can be an elastic plate, e.g. made of hard foam, which deforms elastically in the event of an impact and thereby itself absorbs part of the impact energy and also distributes it over a larger area. The load distribution plate is designed as a cover plate that positively engages the airbag module in the lower part Area of the control panel or the dashboard cladding, the airbag module, for example, can be integrated on the driver's side or on the passenger's side

In a further, advantageous alternative embodiment, the compressed cushion is arranged inside the airbag, so that the expansion of the cushion takes place simultaneously with the expansion of the airbag. Small cushion parts or particles can be used, so that after the airbag module has been triggered, the surface of the cushion is very large is large and the expansion of the cushion takes place quickly

The advantageous arrangement of the at least one compressed cushion in the area next to an opening of a folded airbag ensures that the cushion is independent of the position of the airbag during inflation and after the airbag has collapsed. The cushion or cushions can therefore be independent of the airbag an area where there is a risk of impact is also provided. The function and mode of operation of the airbag are not restricted or changed by the upholstery. It is therefore possible to provide an airbag, for example for the front passenger, which extends to the upper body of the front passenger. The effect of the expanded upholstery is reversed by does not affect the condition of the airbag

In a preferred specific embodiment, part of the gas flow generated by an airbag gas generator can also flow past the film via a gas channel, preferably via gas through-openings, the gas then preferably also being introduced back into the gas bag. As a result, there is no gas for inflating the air bag Lost By passing the gas past at least one cushion and also through the existing connection between the cushion and the airbag, the expansion of the foam material is supported or accelerated, since the occupant can push the gas out of the airbag when moving forward, a part of this the gas that is pressed out goes back into the foam. The expansion of the at least one cushion can take place here after the airbag activation, the expansion of the cushion material as a whole can happen relatively slowly, since there can be a relatively large time interval overall between a PN collision and a subsequent secondary collision

More preferably, the at least one cushion covers at least the area of the exit opening in the expanded state. However, the at least one cushion preferably covers the entire impact area, if possible. This provides effective impact protection for a secondary collision and, if necessary, further subsequent collisions

In combination with an airbag that can be acted upon once or in multiple stages in the event of a collision with gas, the invention is particularly well suited for implementing multiple collision protection and thus for reducing the consequences of secondary collisions. The method according to the invention for operating such a multiple collision protection device provides that the draw an airbag, a compressed safety cushion, which is preferably formed from automatically expandable material, is released for expansion according to the invention in this way, the airbag ensures quick and safe protection against the impact of a pnm collision, while the somewhat slower expanding safety cushion unites ensure effective occupant impact protection in subsequent secondary collisions

The advantages of the automatically unfolding safety cushion are that no additional energy sources are required for activation. Combination with existing safety systems, for example airbags, means that no additional acceleration sensors are required to detect a collision

For the occupants of a motor vehicle, the relatively slow expansion of the safety cushion according to the invention compared to the airbag has the further advantage that there is practically no risk of injury due to an explosive deployment, as sometimes occurs, especially in children, in airbags

Exemplary embodiments of the invention are explained in more detail below with reference to the drawings, which show in detail

1 shows a schematic sectional illustration of a driver airbag module with a safety cushion according to the invention, 2 shows a front view of the airbag module according to FIG. 1,

2 shows a detailed representation of the airbag module according to FIG. 1 in a first variant,

an airbag module as in Figure 3 in a second embodiment,

an airbag module as in FIG. 3 in a third embodiment,

1 shows a cross-sectional view of a knee airbag module in the lower region of a control panel,

6 shows a detailed view of the knee airbag module from FIG. 6 in a first embodiment,

6 shows a detailed view of the knee airbag module from FIG. 6 in a second embodiment,

6 shows a cross-sectional view of the knee airbag module of FIG. 6 after activation,

2 shows a cross-sectional view of a knee airbag module according to a third embodiment,

a cross-sectional view of the knee airbag module of Figure 10 after activation

1 shows a schematic cross-sectional view of a first embodiment of a restraint system in a control panel on the passenger side of a motor vehicle,

12 shows a plan view of an expanded cushion of the restraint system from FIG. 12,

2 shows a schematic cross-sectional view of a second embodiment of the restraint system from FIG. 12 in detail,

a schematic cross-sectional view of a third embodiment of a restraint system 1 shows a steering wheel unit of a passenger vehicle as a whole, shown schematically in section and provided with the reference number 1. A steering wheel hub 3 is attached to a steering column 2 and carries a steering wheel rim 4

An airbag module 5 is located in the interior of the steering wheel hub 3. The airbag module 5 has a gas generator 6, by means of which a gas bag 8, shown folded together, can be acted upon by gas via a diffuser 7

The reference numeral 9 denotes a safety cushion made of open-pore plastic foam, which is welded into a plastic foam shell in the compressed state. The compressed safety cushion 9a is shown in dotted lines. Furthermore, there are 5 release agents in the airbag module in the form of pivotable spikes

10 attached These are arranged so that when the gas bag 8 is acted upon by gas from the gas generator 6, the domes 10 are pivoted against the compressed safety cushions 9a, so that the cover bursts and the safety cushions 9a expand into the expanded state 9b, which is shown in broken lines is drawn

2 shows a front view of the steering wheel 1 according to FIG. 1 using the same reference numerals. The safety cushion 9 according to the invention can then be clearly seen, namely once in the compressed state 9a shown in broken lines and in the expanded state 9b shown with hatched lines. Alternatively, this safety cushion 9a / b be designed as a one-part ring or in several parts

The airbag module 5 according to FIG. 1 is shown enlarged again in FIG. 3, the same reference numerals being used. This clearly shows the arrangement of the separating means with pivotably mounted mandrels 10, which can be moved by the deploying airbag 8 against the compressed safety cushions 9a From this illustration it can also be seen how the compressed safety cushions 9a are welded into a foal sleeve 11. This foal sleeve 11 is easily destroyed by the spikes 10

4 shows, in the same representation as FIG. 3, a further embodiment of an airbag module 5 according to the invention. In contrast to the first embodiment, no mechanical separating means are provided here. Instead, the hot gas flow from the gas generator 6 is passed through hot gas channels 12 onto the foils

1 1 welded-in safety cushion 9a passed through this hot secondary gas flow the foal sleeve 11 is also reliably destroyed, so that the compressed foam 9a can also expand unhindered

In the third embodiment of an airbag module 5 shown in FIG. 5, the airbag 8 emerges laterally upwards or downwards from the steering wheel hub. Mechanical separating means are again provided in the form of a thorn plate 10 that can be displaced by the airbag 8. However, the safety cushion 9 according to the invention forms a round, Flat cushion, which is attached axially on the hub below a hub cover 13 This hub cover 13 is laterally detachably held with a clip connection 12a. When the safety cushion 9 is expanded into the expanded state 9b, the attachment of the hub cover 13 is loosened and moved with the cushion so that the expanded safety cushion 9b shown in dashed lines is available as impact protection

The mode of operation of the airbag modules 5 according to the invention has already been explained above. It goes without saying that, in addition to the illustrated embodiments, a large number of further practical embodiments of the safety cushion 9 according to the invention are possible, both in the combination shown with airbag modules and in sole mounting

6 schematically shows a cross-sectional view of a knee airbag module 1 '. The knee airbag module V is integrated in the lower region, ie in the leg region, of a control panel 2' of a motor vehicle. In the non-triggered state of the knee airbag module 1 ', it is covered by a cover 3' a folded gas bag 4 'is arranged on the cover 3'. An inlet opening of the gas bag 4 'is open to a gas generator 5'

A compressed foam pad 7 'is arranged between the folded gas bag 4' and a base plate 6 'of the knee airbag module 1' around the gas inlet opening of the gas bag 4 '. The gas generator 5', the foam pad T and the gas bag 4 'are pre-assembled on the base plate 6' , so that the airbag module is installed as a compact unit in the lower region of the control panel 2 '. The cover 3' is fastened above this to protect the airbag 4 'from damage

Before assembly, the foam pad 7 'is already welded into a plastic sheet 8' (FIG. 7 or 8) in which the foam pad 7 'is evacuated Condition is maintained During the evacuation of the open-pore material of the foam cushion 7 ', the air escapes, so that the foam cushion T can be compressed to a fraction of the volume of its expanded shape

7 shows a detailed view according to a first exemplary embodiment of the knee airbag module 1 'from FIG. 6. A mandrel 10' is arranged on the base plate 6 'of the knee airbag module 1' at the outer end of a pivotable lever 9 '. The mandrel 10' points in the direction of the foam cushion 7 'When the airbag is released, the gas bag 4' is pressed apart in the region of its gas inlet opening, as a result of which the pivotable lever 9 'is pivoted in the direction of the foam cushion T. By pivoting, the mandrel 10' presses into the plastic film 8 'and tears in the process the plastic film 8 ', so that air can penetrate through it. Air enters the pores of the material of the foam cushion 7' and the foam cushion expands. During expansion, the foam cushion 7 'exerts pressure on the plastic film 8', so that this tears further and the expansion of the foam pad T continues with further tearing of the K unststofffoil 8 'so that the foam pad can expand to its maximum volume

FIG. 8 shows a second embodiment of the knee airbag module 1 'shown in FIG. 6'. Openings 11 'are provided in the gas inlet area of the gas bag 4', through which a portion of the gas from the gas generator 5 'flows out of the gas inlet area after the draw and flows in again Gas emerging through the opening 11 'flows past the plastic film 8' and damages it either mechanically by tearing due to the high flow rate or thermally by melting due to the high temperature of the gas. After the film is damaged, air and gas from the gas generator penetrate here the film 8 'and the foam pad 7' expands

9 shows the knee airbag module 1 'of FIG. 6 after activation with the gas bag 4' fully inflated. After activation, the pressure 3 of the gas bag 4 'causes the cover 3' to be attached to the control panel 2 'or to the base plate 6 'Detached and moved in the direction of the leg space of the motor vehicle The cover 3' is an elastic hard foam plate which distributes the force of the impact of the leg or knee of the occupant evenly over the gas bag 4 'during the puncture collision In comparison to the inflation of the gas bag 4 ', the expansion process of the foam cushion 7' takes place more slowly. After the expansion, the volume of the foam cushion 7 'takes up less space than the volume of the fully expanded gas bag 4'. After the gas collision 4 'after the pneumatic collision due to the Gas loss has already collapsed, on the other hand, the foam pad 7 'is retained as an energy absorber for a further impact of the knee or leg

10 and 11 show cross-sectional views of a knee airbag module according to a third embodiment once before and once after activation of the airbag module. For elements with the same functions as those shown in connection with the previous figures, the same reference numerals are used

In this exemplary embodiment, the parts of the foam cushion 7 'are enclosed in an airtight manner in the gas bag 4'. After the knee airbag module 1 'has been released, the parts of the foam cushion 7' are distributed within the inflated gas bag 4 ', as shown in FIG. 11. The gas generator 5' generates a cold gas, so that the parts of the foam pad T are not destroyed due to the high gas temperatures. The individual parts of the foam pad 7 'have a large surface area compared to a compact pad. As a result, the expansion process of the foam parts takes place faster by absorbing gas from the gas generator 5' and the particles have expanded before the gas has completely escaped from the gas bag 4 '. After the gas has escaped from the gas bag 4', for example via outflow openings, the volume of the gas bag 4 'is reduced to the volume which then passes through the foam cushion 7 'is taken when the gas bag is relieved 4' stretches the foam pad 7 'again and, if necessary, draws air back into the gas bag 4'. With catch straps 12 ', the cover 3' is held in front of rigid components, such as the steering adjustment or the ignition lock, after the gas bag 4 'has collapsed, so that the cover 3 'does not slide down with the air-free gas bag 4'. In the event of a knee impact, for example during a secondary collision, on the cover 3 ', the energy absorption effect of the foam parts in the gas bag 4' is now available for absorbing the collision energy Gas pressure in the gas bag 4 'takes over the restraining function, the restraint in a secondary collision occurs only through the foam cushion 7', the identifier of which is preferably softer in this case 12 shows a restraint system for Mehrfachkol sions in a schematic cross-sectional view. The restraint system is integrated in a modular design into a control panel 1 "of a motor vehicle on the passenger side. In a module housing 2", a gas generator 3 "is arranged in the rear area of the module, which during a Pnmark collision is triggered. Before the gas generator 3 "is triggered, a folded airbag 4" lies behind an outlet opening 14 "for the airbag 4". After the triggering, the gas generator 3 "generates gas which is released through an opening in the airbag 4" the airbag 4 "and opens a cover of the module housing 2"

Laterally offset to the outlet opening of the airbag 4 ", two compressed foam pads 5" are arranged above and below the outlet opening. After the cover has been pushed off by the expanding airbag 4 ', the foam pads 5 "are also open towards the vehicle interior and can expand in this direction

In the compressed state, the expandable foam cushions 5 "consist of a compressed and evacuated foam material which is welded into a plastic film 6". In addition to the foam cushions 5 ", a lever element 7" is arranged at the outlet opening of the airbag 4 ", which is pivotally mounted on the module housing 2" At least one mandrel pointing in the direction of the foam cushion 5 "is arranged at the outer end of the lever elements 7". When the airbag 4 "expands during a pnm collision, the lever element 7" is pivoted in the direction of the foam cushion 5 ", the mandrel 8" being inserted into the plastic film 6 "is pressed in. This partially destroys the plastic film 6" and air penetrates the foam material. The pores of the foam material fill with air and the foam material begins to expand, which destroys the remaining film and exposes the expanding cushion. The fully expanded cushion 9 " takes up a multiple of the volume of the compressed foam pad 5 ". In FIG. 12, the expanded foam pad 9" are shown schematically as broken lines

13 shows the expanded foam cushions 5 "in a top view of the control panel 1". The expanded foam cushions 9 "cover the impact area of an occupant on the control panel 1" during a collision and the outlet opening of the airbag 4 ", thereby providing effective impact protection provide secondary or subsequent collisions The compressed pads 5 "are produced by evacuating the originally expanded, fully expanded pads 9", pressing them into the shape of the compressed pads 5 "and then enclosing them in a cover. After tearing the cover, the pad 5" expands again in its original size and shape. This allows the geometry of the expanded cushion to be precisely defined for the need for impact protection

A second embodiment of the restraint system is shown in FIG. 14 in a schematic cross-sectional view, in which case the lever element is replaced by a pivotable housing part 10 "with a plurality of spikes 8". Before the airbag is triggered, the housing part 10 "lies over the outlet opening of the airbag 4 'and is pressed by this onto the foam pad 5 "when it is drawn. Several mandrels 8" are arranged on the outside of the pivotable housing part 10 ". The mandrels 8" tear the plastic film of the foam pad 5 "at several points, so that the expansion of the compressed foam 1 1 "faster

A third embodiment for a restraint system is shown in a schematic cross-sectional view in FIG. 15. In this embodiment, the gas generated by the gas generator 3 "is introduced into the airbag 4" via a diffuser 12 ". A small part of the gas generated by the gas generator 3" flows through side gas channels 13 "not directly in the airbag 4" but laterally along the outlet opening of the airbag up to the compressed foam cushion 5 "There the gas hits the plastic film 6" through openings in the gas channels 13 ", which includes the compressed foam 1 1" through the high flow rate of the gas and its high temperature, the plastic film 6 "is damaged and the expansion process of the compressed foam 1 1" described above begins

The folded airbag 4 "is folded into the channel of the outlet opening and the lower edge of the opening of the airbag 4" is fastened to the outer edge of the outlet opening. As a result, the gas flowing past the foam pads 5 "during the expansion of the airbag 4" also reaches inside , so that the gas previously branched off from the gas generator 3 "also contributes to the expansion of the airbag 4"

The gas flowing past the foam pads 5 "contributes to the expansion of the compressed foam 1 1", since the compressed foam material is constant is charged with the gas and a high pressure is available for expansion. This process is continued while the generation of the gas by the gas generator 3 "has already been completed, since during the impact phase the occupant presses against the airbag 4" and the gas is returned from the inside towards the foam cushion 5 ".

LIST OF REFERENCE NUMBERS

1 steering wheel unit 5 "foam pad

2 steering column 6 "plastic film

3 steering wheel hub 7 "lever element

4 steering wheel rim 8 "mandrel

5 airbag module 9 "expanded cushion

6 gas generator 10 "swiveling housing part

7 diffuser 11 "compressed foam

8 gas bag 12 "diffuser

9 safety pads 13 "side gas channel

9a compressed safety ^cushion '14 "outlet opening

9b Safety cushion in the expanded state

10 spines

11 foil cover

12 hot gas channels

12a clip connection

13 Hub cover r knee airbag module

2 'control panel

3 'cover

4 'gas bag

5 'gas generator

6 'base plate

T foam pad

8 'plastic film

9 'pivoting lever

10 'mandrel

11 'gas opening

12 'Fangbaπd

1 "control panel

2 "module housing

3 "gas generator

4 "airbag

Claims

Personal restraint device for the passenger compartment of a motor vehicle with at least one impact protection element and a release device that actuates the impact protection element in the event of an impact, the impact protection element having at least one safety cushion that is compressed in the non-activated basic state of the release device and that can be released by the release device for expansion , The safety cushion (9, 7 ', 5 ") in the compressed state (9a) is enclosed in a sheath (1 1, 8', 6") which the safety cushion (9, 7 ', 5 ") in the activated state of the Release device for expansion releases

Restraint device according to claim 1, characterized in that the material of the cushion (9, 7 ', 5 ") is a compressed and / or evacuated foam which, when exposed to air and / or gas from the gas generator (6, 5', 3 ")

Retention device according to claim 2, characterized in that the foam is an open-pore plastic foam

Restraint device according to one of claims 1 to 3, characterized in that the compressed cushion (9, 7 ', 5 ") is enclosed by a film (8', 6") and / or a net as a sheath, which during or after Triggering the gas generator (6, 5 ', 3 ") is torn open or destroyed

Restraint device according to claim 4, characterized in that the film (8 ', 6 ") encloses the compressed cushion (9, 7', 5") in an airtight manner

Restraint device according to one of claims 1 to 5, characterized in that the release device has separating means (10, 12, 10 ', 8 ", 10") for destroying the casing (1 1, 8', 6 ') Retention device according to claim 6, characterized in that the separating means comprise drivable cutting means

Retention device according to claim 6 or 7, characterized in that the separating means can be driven by a gas generator

Retention device according to claim 6, characterized in that the hot gas outlet of the gas generator is directed onto the casing (11, 8 ', 6 ")

Restraint device according to one of Claims 6 to 9, characterized in that the triggering device (6, 10, 12) can be actuated by an airbag (8, 4 ', 4 ") which can be acted upon by gas

Retention device according to claim 10, characterized in that separating means are attached to the airbag

Restraint device according to Claim 10, characterized in that separating means (10, 10 ', 8 ", 10") can be actuated from the airbag (8, 4', 4 ")

Restraint device according to claim 12, characterized in that the expanding airbag (8, 4 ', 4 ") has one or more pivotable mandrels (10, 10', 8") as cutting means in the sheath (1 1, 8 ', 6 " ) prints

Restraint device according to one of claims 10 to 12, characterized in that the hot gas outlet (12) of an airbag gas generator (6) is directed onto the casing (11, 8 ', 6 ")

Restraint device according to claim 14, characterized in that part of the gas flow from the gas generator (3 ") via at least one gas channel (13"), which preferably has gas through openings in the area of the at least one cushion (5 "), on the casing (6") streamed past and preferably then also enters the airbag (4 ")

16. Restraint device according to one of claims 10 to 15, characterized in that the airbag is arranged in an airbag housing (5) in the folded state and the safety cushion (9) is accommodated in the airbag housing (5).

17. Restraint device according to one of claims 1 to 16, characterized in that the safety cushion (9) is ring-shaped or segment-shaped.

18. Restraint device according to one of claims 1 to 17, characterized in that the safety cushion (9) is flat.

19. Restraint device according to one of claims 10 to 18, characterized in that the airbag (8) is attached to the steering wheel (1) of a motor vehicle.

20. Restraint device according to one of claims 1 to 19, characterized in that the safety cushion (9) is attached under a removable cover (13).

21. Restraint device according to one of claims 1 to 20, characterized in that at least one safety cushion (9) is attached to the steering wheel hub (3) of a motor vehicle.

22. Restraint device according to one of claims 1 to 21, characterized in that the restraint device is integrated in a control panel (1 ") of a motor vehicle, preferably on the passenger side.

23. Restraint device according to one of claims 1 to 18, characterized in that the restraint device is arranged in the leg region of a vehicle occupant in a motor vehicle and at least one airbag (4 '), at least one gas generator (5') for inflating the at least one airbag

(4 ') as well comprises a load distribution plate (3) which is displaced towards the leg space by the inflation of the at least one airbag (4 '), the at least one compressed cushion (7') expanding after the gas generator (5 ') has been triggered

Restraint device according to claim 23, characterized in that the compressed cushion (7 ') is arranged on the side of the load distribution plate (3') which faces away from the leg space and which is preferably elastically deformable

Restraint device according to one of Claims 1 to 3, characterized in that the compressed cushion (7 ') is enclosed as an envelope by an airbag (4')

Retention device according to claim 25, characterized in that the gas generator (5 ') generates cold gas

Restraint device according to one of Claims 1 to 25, characterized in that the cushion (7 ') is arranged inside the airbag (4') and is enclosed by an airtight film which is destroyed or torn open when the airbag (4 ') expands

Restraint device according to one of claims 25 to 27, characterized in that the compressed cushion (7 ') has a plurality of compressed cushion particles

Restraint device according to one of claims 10 to 24, characterized in that the at least one compressed cushion (5 ") is arranged in the area to the side next to an outlet opening (14") of a folded airbag (4 ")

Method for the drawing of personal restraint devices in the passenger compartment of a motor vehicle with at least one airbag which can be acted upon by gas for a gas generator, whereby when the airbag is drawn at least one safety cushion compressed in the non-activated basic state of the restraint device is released for expansion, thereby characterized in that the security cushion (9, 7 ', 5') in the compressed State (9a) enclosing shell (1 1; 8 ', 6 ") releases the safety cushion in the activated state of the release device.

31. The method according to claim 30, characterized in that the envelope (1 1; 8 ', 6 ") is destroyed by the hot gas of the airbag gas generator.

32. The method according to claim 31, characterized in that the envelope (1 1, 8 '; 6 ") is mechanically indirectly or directly destroyed by the deploying airbag.