DE10337219B4 - Method for operating an airbag safety system and device for an airbag safety system of a motor vehicle - Google Patents

Abstract

Method for operating an airbag safety system of a motor vehicle in which air in a container is compressed by impact forces generated by a collision via a bumper and a filler is supplied via supply lines to an inflatable airbag,
characterized,
that after reaching a predetermined degree of compression, fuel is injected into the container (2) and the degree of compression is increased until self-ignition of the fuel-air mixture, and
that the self-ignition causes an explosion that inflates the airbag (5).

Description

The The invention relates to a method for operating an airbag safety system a motor vehicle in the air in a container of by compressing impact forces generated via a bumper is and a filler via supply lines supplied to an inflatable airbag becomes.

The The invention further relates to a device for an airbag safety system a motor vehicle with a container filled with air, the one over by an impact in the vehicle longitudinal direction movable bumper compressible and over a supply line to an inflatable airbag can be fed.

From the generic DE 199 50 709 A1 A method and an apparatus for operating an airbag safety system of a motor vehicle is known, in which air in a container and impact forces generated by an impact are compressed via a bumper and supplied as fillers via feed lines to an inflatable airbag. In the known method and the known device, an elastic deformation of the air tank is achieved via the bumper, which leads to the compression of the air in the air tank.

adversely is that the air compression with a certain delay in discharges the airbag. As a result, there is a risk that the airbag is not fast enough is brought to development.

From the GB 1 324 401 a method and an apparatus for operating an airbag safety system of a motor vehicle is known in which located in a container, compressed gas is released and fed via leads to an inflatable airbag. In this case, ambient air is sucked in according to the Venturi principle and used to fill the airbag.

adversely is that the air compression with a certain delay in discharges the airbag. As a result, there is a risk that the airbag is not fast enough is brought to development.

From the DE 22 29 037 C2 An apparatus and method for an airbag safety system of a motor vehicle is known, in which an airbag is inflated from a compressed gas source with the intake of air. This passive-acting system also can not contribute to the reduction of impact forces.

From the DE 2 008 093 A Also, an apparatus and method for operating an airbag safety system of a motor vehicle is known in which gas is supplied from a gas generator arrangement while sucking in ambient air via supply lines to an inflatable airbag.

From the DE 34 22 263 A1 a device for an airbag safety system of a motor vehicle with a filled with a gaseous medium, deformable reservoir is known, which communicates via a feed line with an inflatable airbag.

adversely in the known system is that due to the deformable container a delayed Inflation of the airbag can be done.

From the US 3,922,002 An apparatus and method for an airbag safety system of a motor vehicle is known in which impact forces via a bumper compress a trapped in a flexible container pressure medium and release after reaching a certain compression by piercing a membrane, the supply line to the airbag.

adversely also in this known device or method is that too Here for inflating the airbag a relatively long time interval passes.

task The present invention is therefore an apparatus and a A method of operating a reusable airbag safety system to create, which avoids the disadvantages mentioned above.

These Task is relative the method in conjunction with the preamble of the claim 1 solved by that after reaching a predetermined degree of compression fuel in the container injected and the degree of compression to the self-ignition of Fuel-air mixture increased and that the self-ignition causes an explosion, which inflates the airbag.

This advantageously achieves that impact forces are used for compressing the air in the container, which at the same time leads to a corresponding reduction of the impact forces. By the injection of fuel into the container and taking place at the appropriate degree of compression self-ignition is an explosive, ie rapid inflation of the airbag he enough.

According to one preferred embodiment of Invention, the airbag is inflated under suction of ambient air. This results in a larger amount of filler for inflating the airbag available.

The Task is relative the device in conjunction with the preamble of the claim 3 solved by that the container as a cylinder is formed with a combustion chamber in which a connected to the bumper Piston for generating an overpressure slidably mounted is that the combustion chamber with an injection nozzle for injection a fuel is connected, that the overpressure to a degree of compression Can be brought, the self-ignition of the fuel-air mixture leads, and that the supply line over lockable by exhaust valves exhaust ports the combustion chamber connects to the airbag.

advantageous Features further develop the subject invention and are each in the subclaims contain. These will now be referred to.

According to the present Invention provides a reusable airbag system, that in intensity its protective effect a lightning-fast response to the impact exercises. The is achieved by achieving a degree of air compression one in the air tank atomized Fuel ignites spontaneously, This is injected there to the air compression through To discharge explosion.

there is the air tank for generating a pulse-like propagating in its interior overpressure, as a similar to an internal combustion engine Combustion unit designed to reduce the mechanical energy of the impact converted into an explosion, whose cylinders and pistons from the solid and dimensionally stable Materials are made to air between the two to compress plane-parallel.

In order to the elastic deformation of the air tank is excluded and the Steaming capacity of Systems improved. Therefore, compared to known methods and devices the same compression and this corresponding degree of absorption reached faster.

According to one Another aspect of the present invention is a mixture of the exhaust gases and ambient air formed as a filler for airbags serves. This is still an advantage over the known system since the need for a large amount of air, that carries the system, eliminated. This is achieved by the fact that because of the exhaust gases flowing through supply lines a suction effect is effected, thanks to which outside air enters supply lines. It can short-stroke combustion units built with a relatively small volume become. The to the complete cramming the airbags missing amount of filler gets the system because of its suction from the surrounding air by itself.

According to one preferred aspect is a progressive and qualitatively new protective effect scored the energy of impact first by compression and finally attenuated by explosion. Where the absorbency surpassing the compression Impact force from those originating from the explosion and opposed acting force is lifted lightning fast.

at This point shows yet another advantage of the method according to the invention, provided that the resulting from the air compression damping of retrospectively amplified by the explosion inhibitory effect is enhanced. The product serves as the chemical transformed by the explosion Energy in mechanical, as an additional Aids.

ever after dimensioning of the cubic capacity, the injected fuel quantity, As well as the number of combustion units, the protective capacity of the Systems are designed so that in no case the actual Body at all is deformed.

According to one embodiment The invention is the method and the device in a construction realized by virtue of their design in motor vehicles each Kind inexpensive is integrable. In addition, the device according to the invention both to the Front as well as to the rear side of a vehicle are attached.

To a further embodiment the invention is the system with two combustion units as Alternative to the first equipped, that further the reaction of the system develops positively. at this embodiment are multiple combustion units, in an entire block design arranged in parallel. This will shorten the compression time without the complete Airbaganfüllung to impair.

Further Advantages of the invention will become apparent from the following detailed Description and attached Drawings in the preferred embodiments of the invention for example, are illustrated.

The Drawings show:

1 : a schematic sketch of the entire system in the final state of an impact in plan view and partially in the breakaway,

2 : one of the 1 similar representation of the system in another embodiment of the device, wherein the length of the leads and the side members of the body are drawn broken;

3 FIG. 4 is a longitudinal section of a combustion unit of the apparatus in the instantaneous state of atomization of a liquid fuel. FIG.

4 : one of the 3 corresponding top view with the explanatory outlines,

5 : An enlarged view of the injection pump of 3 in longitudinal section,

6 : one of the 3 corresponding cross-section along the line AA cut,

7 : one of the 3 corresponding side view cut along the line CC,

8th : one of the 3 corresponding plan view along the line BB cut.

1 shows a device for implementing a method according to the invention using the example of a passenger car. The device according to the invention has a movable bumper 1 on, in the vehicle frame guided path is parallel to the straight direction of travel. Next, it contains a composite construction, which is a combustion unit 2 which is arranged adjacent to the receiving of the bumper transmitted impact forces on the rear side of the construction fitting and rigidly coupled thereto. Thus, a movement of the bumper causes 1 a compression in the combustion unit 2 located air.

The combustion unit 2 is preferably an air tank. It is designed to convert the mechanical energy of the impact into an explosion when air heating caused by the compression is operated to a certain degree, in which fuel injected in the heated air ignites spontaneously and serves to generate a pulse-like propagating overpressure.

at a compression pressure in the combustion unit whose height is lower as one for the Explosions provisions suitable degree, the damping effect results elastic. It follows that the system is two different successively following types of energy attenuation united. The detailed Construction and operation of the combustion unit and the system as a whole is described below.

Furthermore, the device has the leads 3 on, which are mainly the air hoses and which are integrally assembled in a construction which a suction system 4 is. This ensures the intake of fresh air into the system, expands foreign, forcibly inflated body and particles, and influences the formation of a mixture, which is responsible for the filling of the airbags 5 serves.

In addition, the 1 and 2 schematically and greatly simplified a mounting plan of the accommodation of the device on the floor assembly of a motor vehicle support structure 6 The support structure is for receiving the device with an additional auxiliary cross member 7 and with the Ecklaschen imported from the stiffening grounds in expansion of the floor assembly 8th strengthened. The side members 9 are in accordance with the in 1 and 2 shown manner to those for the guidance of the bumper 1 mounted rail 10 to wear.

The in the 3 shown combustion unit 2 has a cylinder 11 and a rigidly connected cylinder head 12 in which a combustion chamber 13 lies, as well as a piston 14 with the displacement approach 15 which serves in the combustion chamber for generating a ring vortex of the static air displaced therefrom.

These Components are made of dimensionally stable and solid material types, to compress the air between them plane-parallel and to withstand the explosion caused by explosion.

In addition, the combustion unit 2 equipped according to their function similar to an internal combustion engine, without belonging to this. The other essential components of the combustion unit are:
A push rod 16 ; a piston pin 17 ; one in the function of the rocker arm 18 directed injection nozzle 19 ; to control the injection and exhaust events, corresponding control cam 20 and 21 whose command profile relates to the translational movement of the bumper 22 determine which cams are attached and connected; the exhaust valves 23 for the rapid emptying of the combustion chamber of exhaust gases twice in the combustion chamber 13 are present, and which are arranged on the same axis opposite to each other and perpendicular to the cylinder axis.

The forced use of the exhaust valves via this assigned and in a holder 37 housed roles 24 that with the shock Stan ge 22 are attached in direct contact, which the compression springs 25 maintained; the outlet channels tangentially opening into the combustion chamber 26 , which are directed opposite to each other, to the terminal itself, with the front part 27 the supply lines 3 linked exhaust manifolds 28 to make accessible.

These components of the combustion unit are particularly useful in the 3 and 4 attached connection points of the combustion unit attached. In the following text further constructional details of the design and arrangement of these with respect to their interaction with other components of the system will be described.

The procedure is structured so that the drive of the injector 19 and the exhaust valves 23 from the rectilinear motion of the pressure plate 29 , which rests against the bumper, can be performed. For this purpose is the bumper 22 the combustion unit 2 formed curved by 180 °, and is with the pressure plate 29 via telescopic nodes 31 connected. The pressure plate closes 29 showing the two straight stretched sections 30 the bumper 22 binds the chain of a consequently formed frame construction.

In addition, as it is known from the 7 it can be seen, telescopic nodes 31 in one piece a shock 22 and adjusting rod 32 on. The latter sit unmoving in the pressure plate 29 and serve the first, from which they are extendable, as guide columns. This results in the shortest length of construction in the longitudinal direction, because when moving the pressure plate until the bumper is introduced into the insert, a larger part of the displacement stroke corresponding to the damping process of the method is caused by the movement of the adjustment rods 32 in the bumper 22 is covered.

Because of the lightweight construction and space saving, the pressure plate in the plan view represents a diamond with rounded corners whose extent in the direction of their smaller diagonal to the value of the cylinder diameter 11 equivalent. The upper side of the printing plate 29 , which faces away from its side in communication with the bumper side, forms a bearing surface for the expansion of the construction of the combustion unit 2 ,

For their function, telescopic nodes are designed such that the fitting rods 32 with two opposing attacks 33 are equipped and the rectilinear sections 30 the bumper 22 at its ends with a slot 34 are formed, in which the attacks are stored with the freedom of movement. In this case, the connecting parts of the telescopic node shock and Anpasstange are tubes.

The Anpasstangen are against axial displacement by means of the screw 35 secured. The stops are cylindrical and are formed in their places on the fitting tube from this. The telescopic knots also include the tension springs 36 , who are anxious to keep the adjusting rod in the bumper to the stop, and as a means to return the bumper 22 attached to their original location on the combustion unit. On the one hand, the tension springs are on the cylinder head 12 and on the other hand on the bumper associated pipe socket 38 attached. The trained on the cylinder head pads 39 limit the action of the springs 36 ,

It is envisaged that the effect of the compression springs 25 of exhaust valves stronger than the action of the tension springs 36 is. As a result, the bumper becomes 22 that are relative to the exhaust valves 23 is sprung, after opening this between rollers 24 over the cams 21 held clamped.

The lets the atmospheric Air after an impact go inside the combustion unit.

The exhaust valves may alternatively be constructed as already described, on the same principle as a simple pressure valve without cams, because of the lack of such a design forced drive. The strength of the springs 25 should be doing with the nominal pressure in the combustion chamber 13 , in which the pressure valves open, are tuned. But you have to expect that in the combustion chamber 13 generated energy potential to the useful flow rate is not fully utilized.

According to 3 . 4 and 6 include the exhaust valve cams 21 the bumper 22 , the punctual adjustment of Auslassvorgangbeginss with the grooves 40 provided with the help and help of the screws 41 , the cams 21 after fixing her position at the bumper 22 are kept clamped. The injection cam works in a similar way 20 , The difference lies in the indirect contact of the cams 20 with the bumper 22 , Thus, this is done by pipe socket 38 as it is from the 3 and 4 is apparent.

Based on 3 is the combustion unit 2 with a slider 42 equipped in the cylinder 11 is housed and serves to keep the cylinder sealed against the atmosphere from below, as well as to lubricate it with oil. But it is cylindrical in terms of its outer shape and with the sealing ring 43 and the stuffing box 44 equipped. With occasional stroke, the cylinder covers 11 with a thin layer of lubricant that also seals the cylinder.

To ensure an event without delay of the combustion unit, it is envisaged that both the piston 14 as well as the slider 42 flexible in the cylinder to avoid virtual inclinations 11 being held. This is the push rod 16 , swiveling with the pressure plate 29 coupled.

This is a provided with a convex protrusion pad 45 , which is inserted in a centrally formed on the pressure plate blind bore, with, in the sole of the push rod foot 46 , uniformly shaped recess in contact. An intermediate link 47 that with the pressure plate 29 with the help of screws 48 screwed, ensures that this, in the 3 shown manner, contact produced is not interrupted.

From the 3 follows that the surfaces related both details 45 and 46 come from the cones, whose inclinations are the same and separated by an enlightened game of each other. This is in connection with the bumper 22 with the pressure plate 29 a joint that ensures self-adjustment of the piston.

To the self-adjustment of the slider 42 in the cylinder 11 to create is a slice 49 on the ground 50 of the slider 42 housed and by means of screws 51 screwed. The disc 49 has a conical hole formed in the middle 52 on, on the cylinder-facing and spherical edge of the end face of the intermediate member 47 rests. Besides, the floor is 50 of the slider 42 provided with a through hole, which is a cylindrical surface formed under the spherical surface 53 of the body of the pontic 47 with a proper radial play. This gives the possibility for the slider 42 in the cylinder 11 to pan.

According to 3 and 5 in Combustion Unit equipment is a combined nozzle and pump 19 appropriate. The pump 19 is in its kind of the function with the common constructions identical, but has a considerably simplified structure. In this embodiment, the pump basically includes: a pump plunger 54 located directly above the nozzle; a nozzle needle 55 , which acts as a pressure valve and a ball check valve 56 ,

The Pump is for the occasional individual cases the start of the combustion unit developed.

Therefore, the interior of the pump is a chamber 57 whose volume is designed for an amount of fuel that is in the supply for a single or caused by the next impact ignition of the combustion unit without refilling.

The pump 19 can be through an inlet channel 58 to fill. According to 5 this is with a float 59 and a spring 60 provided that serve the chamber 57 To feed the pump in any spatial position of the vehicle with fuel. The check ball valve 56 , which is arranged between the chamber and the inlet channel prevents the flow of the fuel in the reverse direction.

With the fall of the pump plunger 54 a quantity of fuel missing from the initial filling of the chamber is taken up in chamber by the contents of the inlet channel, which is also considered to be a reservoir 57 dissipated. The drive of the pump succeeds on the way and time by means of the bumper 22 over the injection cam 20 and the rocker arm 18 ,

According to 3 is the cylinder 11 in cohesion with the cylinder head 12 between two other components of the combustion unit by means of the long stud bolts 61 clamped, which are arranged to keep the cylinder biased against unfavorable tensile load of the dynamically acting combustion pressure. The bias connection allows the wall thickness of the cylinder to be dimensioned in terms of economical material savings. This benefits the utilization of the strength of the material and it is the lightweight construction won.

The first of the above-mentioned parts is a sub-acting part on which the cylinder rests, that in the shape of the ring 62 is formed, and the second is acting as a stop means part, the bottom of the upper with the collar 63 reinforced side of the cylinder 11 includes to obtain a tight fit of the cylinder. This part, which has a flange 64 is equal to the printing plate to the extent of its outline 29 executed and also acts as an additional guide means and at the same time as a bezel for the bumper 22 , For convenient adaptation to each other contains the flange 64 the sleeve 65 ,

According to 3 and 8th are for the purpose of a rigid mounting of the device to the vehicle support structure 6 two symmetrically placed, the outer cylinder shell partially hugging supports 66 intended. So that the walls of the cylinder when tightening the screws 61 can not distort and an easy and fast production of the prestressing connection can be obtained, they are in two on both sides of the supports 66 acting as a spreader spacer tubes 67 accommodated.

The lengths of the pipes 67 are designed so that, to prevent the occurrence of tilting moments, one along both supports 66 drawn symmetry axis and the longitudinal axis of the combustion unit in the center of gravity of the construction can cut. In addition, the supports 66 formed with a serving for their attachment to bias connection through hole, through which and by the spacers adjacent to the supports the stud bolts 61 are performed.

The supply lines 3 that aim to promote the filling of the airbags, in one piece:
One with the combustion unit 2 connected front part 27 which serves to achieve a suction effecting the exhaust gases emanating therefrom with the speed of sound. The exit point 68 of the front part 27 is for preventing behind a vortex formation, which may cause the pressure loss, tapered in the flow direction formed; one with the airbag 5 Connected buttock containing an air hose 69 is, and the two aforementioned parts unifying intermediate piece, the suction system 4 represents. This has a hollow body in which a conical end 68 of the front part 27 flows to the outside air into the room under the suction effect caused by this 71 to pump the body.

For the purpose of attracting as much as possible of all the combustion gas in contact with the fresh air, the room is 71 over several lateral openings formed in the body 72 connected to the atmosphere. In order to determine the proportion of fresh air in the mixture, the space surrounds the front part of the supply line at a certain radial distance.

To optimize the performance of the suction system is the room 71 pear-shaped, whose generatrix of the conical part of its surface parallel to the tapered portion 68 of the front part 27 the supply line 3 runs. The paths of the outside air flow are in 1 indicated by arrows.

In this way, the gas stream is mixed from one side with the fresh cold outside air and from the other side with the static air of the supply line and greatly diluted. In this case, its temperature is lowered, which has a, by pressure and temperature compensation between internal and external currents, satisfactorily homogeneous mixture formation. The resulting mixture is under pressure difference between the intake and the rear part 69 the supply line 3 to the airbag 5 promoted as a filler.

The side openings 72 the suction system 4 are excellent flaring holes, the basis of this embodiment of the caps 73 are hugged. The caps hold the mesh filter insert 74 , which is set up for the filtering of foreign bodies. For thorough and reliable filtering, step filters with pre-filtering and fine-filtering are provided.

The place of the suction system / systems 4 is appropriate to select outside of the actual vehicle interior, so that the harmful effect of the gas mixture in the emptying after an impact or frontal collision of the airbags can be avoided. The place for the accommodation of the suction system 4 is not shown because of the many variable equal opportunities.

To the temperature impact of those in the airbags 5 To make bearable exhaust gases bearable, it is envisaged that the airbag cover is covered from the inside with a thin asbestos layer (not shown). The outside air and the cold walls of the supply lines as well as the deploying airbag covers reduce the exhaust gas temperature so that a coating in tenths of a millimeter is enough for it.

To set in motion the airbag device according to the invention, must on the excellent bumper 1 Forces are exercised. In an impact or frontal collision, the bumper slides in to the right 1 and bring the pressure plate 29 and the piston connected to it 14 moving. In this case, the air in the cylinder is compressed, resulting in an increase of the internal pressure in the cylinder 11 as well as in combustion chamber 13 leads. At the same time dive the adjustment bar 32 in the effect of the tension springs 36 non-moving bumper 22 while the attacks slip 33 along the slots 34 , After another movement of the printing plate 29 reach the stops 33 the end of the slots 34 and come with the bumper 22 in touch. The entire duration of this compression phase of the process goes to the start of injection.

This phase mitigates the shocks received frontally on their assets, and also protects the system both from a human footstep on the protruding part of the bumper and at low impact velocities or other minor events. That comes from repelling the pistons 14 because of the resistance of the air to their compression. At the same time the moving ones are returning chen details of the device to the original position.

In the case of a severe impact, the compression of the air due to the further movement of the pressure plate 29 and the piston 14 still further driven, so that the air is heated to a temperature critical for the replacement of the process operations. This raise the attacks 33 from the adjusting bars 32 and the bumper 22 upwards and from that moment both rods converge.

This allows the control cams 20 and 21 from the rectilinear movement of the bumper 22 are driven. In a position of the piston stroke, briefly from the moment when in the combustion chamber 13 developed for the compression of the fuel sufficient compression pressure, the pump starts 19 from the control cam 20 operated rocker arms 18 inject. Thus, the compression phase goes into a process of the process, which takes place abruptly.

Once the ignition temperature is reached, the atomized fuel in the combustion chamber is ignited, but the piston 14 is pushed under the impact of the impact even further up to its highest stroke position, in which its displacer 15 the neck of the combustion chamber 13 almost completely closes without touching it. In this position of the piston, the fuel burns in spite of ceasing its supply into the combustion chamber in full flames. This will cause the piston 14 slowed and stopped in its upward movement.

At this time, the bumper dives 1 so deep inside the vehicle that its front end stops just before the bumper of the vehicle. The outlet control cams controlling 21 open the exhaust valves 23 , In this case, both the injection and outlet start with the position of the piston 14 in the cylinder 11 in accordance.

At the previously described operations of the method are the impact forces that the damping capacity of his Overcome the compression phase, by the nature of their sudden emergence with quite intense Dampened counteraction. there the damping effect acts the compression phase by absorption of the absorbed by her Impact energy part as an incessant part of the complete Protection.

For the design of the system, it should be noted that the extent of the jib protruding beyond the vehicle outline 75 of the bumper 1 (in 1 and 2 shown with the dashed lines) greater than or at least equal to the value of the damping stroke of the piston 14 the combustion unit 2 should be. This is the guarantee that the body of the vehicle for the impact partner is not achievable.

Because of the blast created by the explosion becomes a portion the combusted gas and a static in the supply lines air column pushed to the airbags. Furthermore pulls the pressure wave in the wake of a certain part of the outside air in a mixture ratio behind him.

From that starting in the dimensioning of the displacement of the combustion unit the generated filler to disposal standing capacity and the number of airbags under consideration the volumetric efficiency as a result of both in the system supplied Calculated air quantity and the expansibility of the burned gases become. This interpretation also applies to the reverse calculation.

From the overpressure generated by the explosion and spreading on all sides arises in the system except a force driving the exhaust gas flow also directed one of the acting impact forces Resistance. One of this power will be one of the first Phase left over stayed but weakened Part of the impact energy neutralized. This creates a complete Protective effect for both the inmates as well for the vehicle.

The final starting position after a collision of the whole system, which corresponds to his readiness, is achieved by pushing back the pressure plate 29 and the bumper attached to it 1 when this free movement is given, achieved by the hand applied force. The adjusting rods are driving 32 from the bumper 22 out. Ultimately, the roller holder is pushed by means of special pliers (not shown) 37 into the interior of the combustion chamber 13 , This is based on the action of the tension springs 36 the bottom flattened surfaces of the pipe sockets 38 to the edition 39 , 7 This clarifies attained positions of the bump and fitting rods 22 . 32 ,

The Method can be achieved by using both liquid and gaseous fuels by the corresponding combustion unit equipment of the prior art function. Such a multi-substance capability of the process has for some geographical application areas of considerable importance.

According to another embodiment of the device, which may form as an alternative to the first embodiment without affecting the perfection of the airbag refill this according to 2 two or more combustion units 2 , The stroke length of the combustion units is reduced in proportion to the number of combustion units as compared with the above-mentioned embodiment for accelerating the reaction of the system.

Thus, the same of the first embodiment of the airbag approximate volume is achieved with even shorter time from the exhaust stream. The combustion units in this embodiment operate synchronously, are enclosed in a block in parallel, and for shortening the width of the coupled structure as well as the numbers of control cams 21 connected so that two adjacent combustion units have a common bumper part.

In this way, the possibility for the method results in both shortening the duration of its compression phase and the development or the structure of its protective effect as a whole. It can also be the boom part 75 of the bumper 1 whose dimension is defined by the stroke length of the combustion unit, be small.

in the Further can all embodiments described above instead of the direct Mixture in the airbags one at the back of the supply line include connected control device.

The Control device regulates such that in an accident, if, in dependence from the existing impact conditions and according to the vehicle speed and outside temperature in terms of the season, a volume dictated by a sensor of the mixture lower than the predetermined volume is dissipated in airbags, this excess amount the mixture is discharged into the environment or, adapted to the respective needs, in additional at other locations of the vehicle, e.g. in side games as well in roof sections, installed airbag-like bags is discharged. So it turns out that a vehicle occupant at such a fall from all sides intercepted and optimally exploits the protective performance of the system becomes.

Claims (10)

Method for operating an airbag safety system of a motor vehicle in which the air contained in a container of impact forces generated by a collision is compressed via a bumper and a filler is supplied via supply lines to an inflatable airbag, characterized in that after reaching a predetermined degree of compression fuel in the container ( 2 ) is injected and the degree of compression is increased to the spontaneous ignition of the fuel-air mixture, and that the self-ignition is an explosion, the airbag ( 5 ) inflates. Method according to claim 1, characterized in that the airbag ( 5 ) is inflated under suction of ambient air. Device for an airbag safety system of a motor vehicle with a container filled with air, which is compressible via a bumper movable by an impact in the vehicle longitudinal direction and can be supplied via an inlet to an inflatable airbag, characterized in that the container ( 2 ) as a cylinder ( 11 ) with a combustion chamber ( 13 ) is formed, in which one with the bumper ( 1 ) connected piston ( 14 ) is displaceably mounted for generating an overpressure that the combustion chamber ( 13 ) with an injection nozzle ( 19 ) is connected to the injection of a fuel, that the overpressure can be brought to a degree of compression, which leads to spontaneous ignition of the fuel-air mixture, and that the supply line ( 3 ) via exhaust valves ( 23 ) closable outlet channels ( 26 ) the combustion chamber ( 13 ) with the airbag ( 5 ) connects. Apparatus according to claim 3, characterized in that the supply line ( 3 ) between combustion chamber ( 13 ) and airbag ( 5 ) an intake system ( 4 ) for sucking in ambient air. Apparatus according to claim 4, characterized in that the suction system ( 4 ) is formed as a hollow body, in whose interior ( 71 ) the front part ( 27 ) of the supply line ( 3 ) with his to the airbag ( 5 ) tapered exit point ( 68 ) opens, that several lateral openings ( 72 ) for sucking ambient air into the interior ( 71 ) are arranged in the hollow body, and that the rear part ( 69 ) of the supply line ( 3 ) the interior ( 71 ) with the airbag ( 5 ) connects. Apparatus according to claim 5, characterized in that the interior ( 71 ) is pear-shaped and its conical part is at a radial distance parallel to the tapered exit point (FIG. 68 ) runs. Device according to one of claims 3 to 6, characterized in that one of the bumper ( 1 ) movable bumper ( 22 ) with control cam ( 21 ) for controlling the exhaust valves ( 23 ) and with a control cam ( 20 ) for controlling the on spray nozzle ( 19 ) is provided. Device according to claim 7, characterized in that the bumper ( 22 ) curved to form a frame construction by 180 ° and on fitting rods ( 32 ) with one on the bumper ( 1 ) arranged pressure plate ( 29 ) connected is. Apparatus according to claim 8, characterized in that the pressure plate ( 29 ) via a push rod ( 16 ) with the piston ( 14 ) connected is. Apparatus according to claim 8 or 9, characterized in that the Anpasstangen ( 32 ) lateral stops ( 33 ) in slots ( 34 ) the bumper ( 22 ) in motion.