DE20122809U1 - Single and multi-stage cold gas generator, especially for automotive airbag systems - Google Patents

Abstract

One- or multi-stage gas generator, in particular for automotive airbag systems, with at least a gas container (16, 39, 50) in which a supply gas (6, 38, 45) is contained, the gas container at least one plate-shaped Chamber closure (3, 70, 19, 27, 30, 35) which by means of a device (18, 21, 23, 26, 31, 71, 44, 65, 67) can be released and thereafter the openings (8, 5, 13, 15, 72, 55, 66) fluidly effective releases, wherein the previously stored gas can flow predetermined and hereby a controlled inflation characteristic for example can be realized on the inflator attached airbag.

Description

The invention relates to a multi-stage gas generator, in particular for motor vehicle airbag systems, in which stored in a gas container and / or gas generated therein can emerge controlled by a plate system from a plurality of outlet openings of the gas container and then serves for example for filling a gas bag of a motor vehicle airbag system. From the DE 196 54 315 A1 a hybrid inflator for inflating airbags is known, which has two combustion chambers, in each of which a propellant charge is arranged. The combustion chambers communicate with a storage chamber which is filled with a supply gas under a certain pressure. The storage chamber has an outlet opening closed by means of a closing element, wherein the closing element is pushed open by means of a rod-like actuating element when the first propellant charge is activated. For this purpose, the rod-like actuator is arranged with its rear end region in front of the connection opening of the combustion chamber, so that this rear area is acted upon by the activation of the propellant charge by the pressure of the hot gas generated in the combustion chamber. The actuator is thereby depressed, so that it pushes the outlet opening of the storage chamber occlusive closing element with its front end. The second propellant of the hybrid gas generator after the DE 196 54 315 A1 is ignited delayed in time, so that the time course of the pressure build-up can be adjusted according to specifications.

To It is also the technical teaching of this prior art possible, various pressure build-up characteristics through the targeted distribution the propellant charges, by the control of the ignition processes and by other constructive modifications, such as the dimensioning of the cross section of the outflow openings the combustion chambers in the bottle part or the gas container to realize.

In one embodiment of the hybrid gas generator according to the DE 196 54 315 A1 the use of two differently sized propellant charges is shown, each driving an actuator for piercing a membrane, each of which closes one of two outlet openings of the storage chamber. Also in this embodiment, the propellant charges are ignited delayed in time, wherein the gas mixture is additionally heated by the respectively last ignited propellant charge.

With the hybrid gas generator according to the DE 196 54 315 A1 Although it is possible to realize a predefined time course of the gas pressure better and easier than would be possible with a single-stage gas generator. The disadvantage of such a multi-stage gas generator, however, is the high development effort, in particular simulation effort, until the gas generator complies with a predetermined time pressure curve within acceptable tolerances. Another significant disadvantage is its high manufacturing costs, which are caused in particular by the parts required for the valve actuation.

moreover use all previously designed or even running gas generators however for each Stage at least one igniter to open valves, membranes or to achieve a multistage. This will be next to the more expensive Multi-stage gas generators also a complex sensor system for Control of the ignition system and a much more complex ignition system itself necessary.

Required but now on the other hand next to a significant cost reduction a multi-step, which can run programmed when the gas generator ignited only once For example, the generation of a relatively small mass flow, at first to unfold the folded bag slowly and thus gently, then but this sack for that the faster in the then available, now somewhat shorter time, to inflate quickly - man would like to So split the fixed total function time of the gas generator in a weak blow phase and in a strong blow phase! - and the, without it a second ignition signal deliver and realize in the form of an expensive ignition in the gas generator to have to!

In the own registrations 20013405.1 and 20013404.3 from 3.8.2000 were already described one-stage and multi-stage gas generator, the above Meet requirements. Here is the multistage by the outflow of Gas from oppressed Chambers predetermined opening another gas-depressed Gas tank sections achieved, as well as by the use of membranes with different Thickness after shooting the central membrane part in connection with incoming gas also a predetermined release / rupture of the residual membrane cause a two-step per used or built Enable membrane.

In both applications, moreover, it is shown how membranes can also be destroyed by other methods than by shooting up or by overpressure or by pyrotechnics, in order to release gas. It is shown how a membrane can be opened by placing a support bar on the non-gas side by an Ak If the membrane is so thin that it could not withstand the gas pressure without the support beam in front of it, that would simply burst. The vote is difficult, in particular the proof of the reliability of the opening even after 15 years of storage in adverse environments or the proof of the reliability of the non-triggering during the entire storage period, although the membrane is so deliberately used extremely unstable or executed. The main problem, however, is that membranes essentially only know the states quite openly and completely closed, with a transition which is extremely fast and can not be precisely predicted (stability problem) and, in addition, a previously unforeseeable number of fragments of the membrane and the one to be kept Caused assemblies. In particular, these fragments make for airbag applications problems that can be retained today only by expensive filter cartridges in the gas generator.

Also in applications 20013405.1 and 20013404.3 of 3,8,2000 it is shown how parts of plates can be used to achieve multistage However, these plates also by the above-mentioned pressure difference both sides of the plate, quasi membrane-like break out and through their mass is a delayed outflow of Allow gas.

Of the The invention is based on the object, a gas generator, in particular for automotive airbag systems, to create that, simply by considering specifications for one is to develop temporal pressure course, with regard to its Inflation characteristics easily adaptable to given requirements and is flexible, the case of only one lighter or only from an ignition signal is controlled and now instead of membranes only from plates for the To lock from depressed Gas volumes consists with the requirement that these plates simply mechanically can be unlocked and no fragments here, no matter which component they may come from, arise. simultaneously should a programmed multistage without further effort and be possible with only extremely low additional costs! The functional principle must be plausible be and a computer simulation simplest possible! The invention solves this problem with the features of the protection claim 1, it is in this Registration enclosed figures closer explained.

Further embodiments The invention will become apparent from the dependent claims.

The invention will be explained in more detail with reference to embodiments shown in the drawing:
The invention is based on the recognition that gas flows can be very easily controlled mass flow through openings and these openings defined by moving plates - but still can be released very quickly. The plates themselves are introduced into the gas generator so that they by pulling one or more retaining pins, especially shear pins or moving a retaining mimic, in particular a rod with notch or Abreißstellen 65 or 67 tear or free, whereby they are accelerated by the applied gas pressure and this in turn, the gas to be flown through openings 8th . 5 . 66 Toward the direction of the airbag bag or airbag can for the gas.

Of the Multi-stage gas generator according to the invention therefore comprises at least a gas container, in which contain a storage gas and / or in which gas can be generated and / or in which gas can be fed is, the gas container several, in the outflow direction parallel outlet openings that has during the movement of a plate or plate system during the operating time of the Gas generator sequentially defines all enabled, i. concerning. gas flow be switched, the outlet openings in terms of their each individual cross-sections and aware of the total cross-sectional area determining flow for the Mass flow of the gas are formed.

1 shows the here announced opening principle with plate technology simultaneously with the possibility to achieve a programmed multi-step:
The gas 6 is in a container 16 with back wall 1 and shut-off plate 3 enclosed, it is under a high pressure, for example 280 bar or 500 bar, thus exerting force on all surfaces delimiting it. rear wall 1 is commonly welded with 16 but they are also deep-drawn containers 16 already common with end cap in one piece, in which case the back wall 1 as an extra part is omitted. The shut-off plate 3 is in 16 used and is over a shear pin 18 held, which is either one-sided introduced - in this case, the plate holds 3 by clamping over its thickness, wherein the clamping action by the groove 2 or the rotation 68 ( 17 ) and the resulting contact pressure of the plate material is significantly enhanced by the gas pressure which is present anyway - or which is still used in second or third place ( 16 ), or simply through the plate ( 15 ) or supporting in the non-compressed part of the gas generator is introduced ( 17 ). In the case of the rod carried out, either one side of the rod shears off, with the other side out of the wall of the gas container 16 or the staff will shed at one or both places, provided it has one or two weak spots or notches indicates that by the displacement of the rod (pushing or pulling is both possible) come into effect (previously, the shear stress on the full cross section of the rod affects, after moving is the weak point or notch in the stress field!).

In this case, the rods are preferably by pyrotechnically actuated actuators 7 pulled or pressed, depending on the selected rod and its or their place of insertion. Of course, here are also electromagnetic and electrodynamic actuators 7 used.

A particularly clever execution is in 10 Instead of a rod which is pulled or pressed by an actuator, here an electrically insulated electrode is used, which consists in particular of wire, graphite, zirconium or magnesium (..or their compounds) and for the triggering of the gas generator by passing current easily heated or ignited (magnesium or zirconium) and thus mechanically hard to be weakened! - The effect is the same as when moving the rod: The gasbedrückte plate breaks the electrode or its remnants, it accelerates very fast, initially crossing the openings 8th and then 5 , Depending on the cross-section of these openings, initially a small mass flow will leave the gas generator in the direction of the airbag bag, then shortly thereafter a much higher, depending on the speed of the plate, the distance, as well as the cross section and the geometry of the openings 8th and 5 , see also opening 66 from 17 ,

The shut-off plate 3 gets off the lid after fulfilling its task 4 intercepted. He blocks either the cross section, provided that in 1 drawn recoil-free diffuser is used, or is designed so that it forms the axially exiting gas flow, either as a ring flow over the slots 10 ( 2 ) or as a central flow over the annular groove 13 and the central hole 15 ( 3 ).

The shut-off plate 3 is at the same time as hermetically sealed completion of the gas container 16 formed either by an inner weld 9 ( 1 ) respectively. 12 ( 3 ) or by a welded foil 11 ( 2 ) respectively. 20 ( 4 ).

From 4 becomes the shut-off plate 3 to a plate system consisting of the plate carrier 70 and the obturator 19 . 27 . 30 , Is the container 16 tubular and round, then the plate carrier automatically becomes a ring. This will be in the arrangement 4 to 8th only a partial cross section of the gas container 16 released, for example, to release only a relatively small maximum gas flow through the gas outlet openings to the airbag bag, just the cross section of the shut-off plate 19 . 27 or 30 ,

In all cases, the shut-off plate is mechanically again, in particular by a shear pin or bolt 21 . 26 or 31 held.

How many such pins on the circumference of the gas container 16 depends on the differential pressure on the plate and essentially on the geometry of the plate itself. In general, you will try to get along only with a pen and thus only with an actuator, simply to save on manufacturing costs! - Even if several pins could be coupled together and thus only one actuator would be needed again, but only at the expense of reliability!

In 5 will be an additional pen 23 used in addition to the actual shut-off plate 27 later also release the entire cross section. In contrast to 1 It would thus be an internal gradation, which took place only within the disk system - but this Plattensys gradation also with the gradation by the successive release of the overflow of type 8th and 5 combined, but today only makes sense, if you look at the openings here in contrast to 1 simply wanted to partially close, in order to reduce the gas mass flow defined after a certain time.

The gas chamber is sealed again by a sealing foil 20 , which is radially inwardly connected to the gas container, in particular welded, whereas the film 24 only the shut-off plate 27 against an otherwise already sealed plate carrier 70 would have to seal.

In 6 is the shut-off plate 30 grafted with radially introduced sealing system. This supports the on the plate 70 resting collar of the shut-off plate only the shear pin or release pin 21 . 26 . 31 ,

All Sealing systems are interconnected according to the special requirement of the Customers interchangeable, as well as all the possibilities shown here, to execute the plates and to seal it again.

The above shown principle of sealing and opening of gas cylinders or Gas tanks through defined releasable plate systems is theoretically up for the practice any number of stages with respect to. Removable from the generator gas mass flow.

In 7 another principle for supporting the release pen is shown: It is part 32 simply one defined in the plates carrier 70 pressed-in support ring or a small paragraph, which is easily sheared when retracting the shear or release pin by the then released and fully pressurized with gas pressure shut-off.

8th again shows another version of this support for the release pin: It was here just shear-material in a form-fitting manner in a groove of the plate carrier 70 inserted or in the manufacture of the plate carrier 70 ditched.

The opening principle by plates held or released by release pins is great for Gas generators whose housing almost complete or even entirely in one production cycle, in particular by injection, Mold or die casting of Plastics and aluminum, are produced.

9 shows such an embodiment: The gas container 39 with a floor 40 , which can also be made of semicircular strength reasons, encloses with the shut-off plate 35 the gas enclosed in it 38 , The shut-off plate is so weakened on the circumference ( 37 ) that the plate without the retracted release pin (release pins) 71 as a result of the pressure on her gas pressure would break out. All parts are sprayed in one, with the back wall 40 in some cases can also be used later. Even the lid 4 can work together with the gas container 39 , the floor 40 and the shut-off plate 35 be made in one piece!

Again, the plate is 35 after pulling out the pen 71 break out and release here in the form of slots drawn outlet openings for Airbagsack more and more. Depending on the disk speed and design of the holes 72 Therefore, the mass flow can be adjusted degressive, linear or even progressive - a possibility that you can not use in the approach when using membranes in place of the shut-off !!

12 and 13 show variations of an "all parts in a manufactured" gas generator: in the gas generator 39 is a cartouche 41 contain the actual gas hermetically sealed. At first it is irrelevant, like the gas 38 is filled: Whether it is liquid or solid gas, which is already in the cartridge located at correspondingly low temperatures in the housing / gas tank 39 is pushed in, or only one somewhere through 39 or 42 filled through protruding nipple and this is then properly closed again - it changes the simple principle proposed here - opening the gas tank by releasing a shut-off 35 nothing, on the contrary, can only fully demonstrate its advantages.

13 shows the same principle, except here is the shut-off plate 35 weakened only in a relatively small environment ( 37 ) while in 12 the shut-off plate 35 weakened all around ( 73 ).

In 15 handed the release pin 65 through the entire plate, so this is held in two places. The release takes place either when the actuator is activated 7 by tightening the pin until the pin end is pulled out of the housing of the gas container and the other part of the pin, which is still in the housing, is sheared off by the pressure on the plate gas pressure or the force acting therefrom - or the rod has Both sides of notch or flat areas, which come when moving the rod by pulling or pressing then in the gap area and thus take effect: The residual material of the release pin is therefore there, so sheared off at the beginning of the pen and the end of the pen. With 63 Here it is shown at the same time, how all the previously shown shut-off plates alternatively and advantageously welded or can be held: Simply welded through the wall or by welding a previously attached here I or V notch in the housing of the gas tank 16 ! Depending on the welding strength, the shut-off plate is only pressed or more or less intimately welded to the housing.

16 shows the use of two release pins or actuators 7 instead of the continuous release pin 65 out 15 ,

In 17 became the radial weld 63 through a rolled seam 64 replaced - here too, depending on the roll depth, the shut-off plate only braced or more or less good form-fitting with the gas tank 16 get connected. The roll depth can also be chosen so that the edge 2 the shut-off plate 3 after actuation of the actuator 7 through the on the shut-off plate 3 acting force bends inward and thus the plate almost freed from the snapping. However, in this case again an inside with the wall of the gas container 16 connected foil 74 similar 11 or 20 be introduced for the hermetic sealing. In 17 At the same time the case of a supported shut-off plate is shown - unlike 15 Here is the release pin led directly to the back of the plate, while at 15 the release pin was passed directly through the plate. The advantage is obvious: one avoids the cross hole of the shut-off plate with the appropriate fitting work and one recognizes from the outside whether the release pin is installed or not (QS is relieved).

• 1. Das Volumen des bedrückten und von der Platte abgeschlossen Flaschenteiles
• 2. Die Gasart im Volumen -möglich sind Helium, Argon, Stickstoff, Luft, Gemische daraus, Flüssiggas um beispielsweise den Kammerdruck möglichst lange durch den Phasenübergang flüssig-gasförmig stabil zu halten, das Expandieren nach dem Aufblasen des Sackes durch die Phasenumwandlung im Sack selbst noch zu ermöglichen oder zusätzlich Energie zu erzeugen durch das Entflammen des Gasgemisches, sofern das Flüssiggas entzündlich bzw. brennbar ist, es kann Gas in fester Form, beispielsweise Trockeneis eingebracht werden, weiter Gase mit gespeicherter innerer Energie wie Butan, Propan, Wasserstoff, Acetylen. In Sonderfällen wird man auch Trockeneis einfüllen bzw. Kohlendioxid oder gar Lachgas verwenden. Auch kann im Gasvolumen das Gas erst erzeugt werden, insbesondere durch eine Verbrennung.
• 3. Der jeweilige Gasdruck
• 4. Das Material der Absperrplatte
• 5. Die Dicke der Absperrplatte
• 6. Die Geometrie der Platte
• 7. Die Unterstützung der Stabilisierung der Platte durch Kippen im Gasbehälter durch Anpressung des Plattenrands durch den Gasinnendruck durch selbstlidernde Maßnahmen (2).
• 8. Die Querschnittsfläche der von der Platte verschlossenen Auslaßöffnungen
• 9. Die Zahl und die Art der Aufteilung der Auslaßöffnungen über den entsprechenden Abschnitt des Gasbehälters 16
• 10. Die Ausgestaltung der Dicht- oder Schweißnähte der Absperrplatten
• 11. Die Ausbildung des Dichtsystems bzw. des Spalts zwischen der abdichtenden bzw. absperrenden Platte und der Wandung des Gasbehälters – beispielsweise kann eine geringe Leckage von einer bedrückten Kammer in die vorherige erwünscht sein, um massenstrommäßig einen Übergang von einer Stufe zur nächsten zu verwirklichen!

As setting for the genera Tor exiting mass flow there is thus in the parallel arrangement of the invention of the shut-off 3 released outflow openings in the airbag bag following parameters or influencing variables:

• 1. The volume of the pressed and finished from the plate bottle part
• 2. The gas type in volume-are possible helium, argon, nitrogen, air, mixtures thereof, liquefied gas to keep the chamber pressure as long as possible liquid-gas stable through the phase transition, expanding after inflation of the bag by the phase transformation in the bag itself still allow or additionally generate energy by igniting the gas mixture, if the liquefied gas is flammable or combustible, it can gas in solid form, such as dry ice are introduced, further gases with stored internal energy such as butane, propane, hydrogen, acetylene. In special cases, you will also fill in dry ice or use carbon dioxide or even nitrous oxide. Also, in the gas volume, the gas can only be generated, in particular by combustion.
• 3. The respective gas pressure
• 4. The material of the shut-off plate
• 5. The thickness of the shut-off plate
• 6. The geometry of the plate
• 7. The support of the stabilization of the plate by tilting in the gas container by pressing the plate edge by the internal gas pressure by self-sealing measures (2).
• 8. The cross-sectional area of the outlet openings closed by the plate
• 9. The number and type of distribution of the outlet openings over the corresponding section of the gas container 16
• 10. The design of the sealing or welding seams of the shut-off plates
• 11. The formation of the sealing system or the gap between the sealing or shut-off plate and the wall of the gas container - for example, a slight leakage from a depressed chamber in the previous be desired to mass flow moderately a transition from one stage to the next to realize!

The The effect of all above-listed insertion sizes is in a computer simulation first roughly recorded and then verified in a few experiments or Enhanced!

The drawn shut-off plates and sealing measures are only exemplary here Registered: The shut-off plates can just as partial in part or in the whole connected with the pipe of the gas tanks, everyone Type of locking plate can in principle also with any other type be connected by sealing system.

Claims (22)

Single or multi-stage gas generator, in particular for automotive airbag systems, with at least one gas container ( 16 . 39 . 50 ), in which a storage gas ( 6 . 38 . 45 ), wherein the gas container at least one plate-shaped chamber closure ( 3 . 70 . 19 . 27 . 30 . 35 ), which by means of a device ( 18 . 21 . 23 . 26 . 31 . 71 . 44 . 65 . 67 ) and then the openings ( 8th . 5 . 13 . 15 . 72 . 55 . 66 ) effectively releasing the flow, wherein the previously stored gas can flow out in a predetermined manner and can thereby realize a controlled Aufblascharakteristik for the example attached to the inflator airbag. Gas generator according to claim 1, characterized in that the outlet openings ( 5 . 8th . 72 . 66 ) is part of a diffuser or a vortex chamber for the gas contained in or producible in the gas container ( 17 ), ie that with discharge of the gas, the entire gas generator remains thrust neutral Gas generator according to claim 1, characterized in that the outlet openings ( 13 . 15 . 55 ) is the beginning of a Gasleitrohres for the gas container located in or be generated in the gas, by the plate system ( 3 . 70 . 19 . 27 . 30 . 35 ) is passed to the location of the remote airbag released gas Gas generator according to claim 1, characterized in that it depends on the plate system located closest to the outflow openings ( 3 . 70 . 19 . 27 . 30 . 35 ) in the gas container ( 16 . 39 . 50 ) connect one or more additional disk systems, each of which again includes a gas and in turn of its own release devices ( 18 . 21 . 23 . 26 . 31 . 71 . 44 . 65 . 67 ) can be released. Gas generator according to claim 1, characterized in that it depends on the plate system located closest to the outflow openings ( 3 . 70 . 19 . 27 . 30 . 35 ) in the gas container ( 16 . 39 . 50 ) connect one or more membrane-like sealed gas chambers, each of which again include a gas. Gas generator according to claim 4 or 5, characterized that all different volumes trapped by the membrane or plate systems be great can and filled with one and the same gas. Gas generator according to claim 6, characterized in that all volumes enclosed by the membrane or plate systems are ver different types of gas are filled. Gas generator according to claim 4 to 7, characterized that all volumes trapped by the membrane or plate systems with different gas pressures filled are. Gas generator according to one of the preceding claims, characterized in that the membrane or plate systems ( 70 ) only a part of its area ( 19 . 27 . 30 ) for that in the gas container ( 16 . 39 . 50 stored gas ( 6 . 38 . 45 ) after release of the release device ( 18 . 21 . 23 . 26 . 31 . 71 . 44 . 65 . 67 ). Gas generator according to Claims 4 to 8, characterized in that the openings of the membrane or plate systems ( 70 ) in the flow direction in each case different sized surfaces ( 19 . 27 . 30 ) exhibit. Gas generator according to one of the preceding claims, characterized in that the respective openings ( 19 . 27 . 30 ) of the membrane or plate systems ( 70 ) are widening in the flow direction or formed in the form of a Laval nozzle. Gas generator according to one of the listed claims, characterized in that the opening time of the plate system ( 3 . 70 ) by the length of the free acceleration path of the plate until it passes the first outlet ( 5 . 10 . 13 ), the mass of the plate ( 3 . 70 ) and the pressure p of the storage gas acting on this plate ( 6 . 38 . 45 ) is set. Gas generator according to claim 1, characterized in that the plate system ( 3 . 70 . 19 . 27 . 30 . 35 ) in whole or in part by a sealing system ( 11 . 20 . 24 . 28 . 74 ) or even hermetically sealed. Gas generator according to claim 1, characterized in that an inner, completely closing or sealing system ( 41 ) is introduced, which seals the gasbed volume or even hermetically seals tight. Gas generator according to claim 14, characterized in that the sealing system ( 41 ) similar to a cartridge in the gas container ( 16 . 39 ) is introduced. Gas generator according to claims 4 to 15, characterized in that the release devices ( 18 . 21 . 23 . 26 . 31 . 71 . 44 . 65 . 67 ) for the additional disk systems individually or in succession or independently. Gas generator according to claim 9, characterized in that in front of the openings ( 19 . 27 . 30 ) expressible or shearable parts ( 32 . 33 ) are introduced, which hold the closures here form-fitting partially and thus the release device ( 18 . 21 . 23 . 26 . 31 . 71 . 44 . 65 . 67 ) relieve. Gas generator according to claim 1, characterized in that one or more outflow openings ( 8th . 5 . 13 . 15 . 72 . 55 ) the shape of a long hole ( 66 ) in order to quasi-linear, degressive or progressive the exiting and from the supply gas ( 6 . 38 . 45 ) supplied mass flow through the passing plate system ( 3 . 35 ) and thus effectively control the inflation characteristic of the airbag connected to the gas generator. Gas generator according to claim 1, characterized in that the plate system ( 3 . 70 ) through connection points ( 9 . 12 . 63 . 64 ) with the gas container ( 16 . 39 . 50 ) is positively or non-positively connected and this holds so strong only that the plate system ( 3 . 70 ) is sealed, but upon actuation of the release device ( 18 . 21 . 23 . 26 . 31 . 71 . 44 . 65 . 67 ) can tear off from the respective wall or stop. Gas generator according to claim 1, characterized in that the gas passes through the released and already pushed plate via slots ( 13 ) in the periphery of the gas container ( 16 ) and then axially over the slots or the annular gap ( 10 ) or a central bore ( 15 ) or via an open cross section ( 55 ) can leave the gas generator. Gas generator according to claim 1, characterized in that the functional parts of the gas container ( 16 . 39 . 50 ), ie incl. floor, panel system, diffuser ( 17 ) or outlet part ( 55 ) Whole or individual parts are made together from a part or in a production process, in particular by spraying, casting, die casting or rapid prototyping. Gas generator according to claim 1, characterized in that between the airbag and the outflow openings ( 8th . 5 . 13 . 15 . 72 . 55 . 66 ) is still one or more filter packages for the removal of particles.