DE2302648A1 - INFLATABLE BELLOWS FOR VEHICLE OCCUPANTS - Google Patents

Description

Inflatable protective bellows for vehicle occupants The invention relates to an inflatable protective bellows for vehicle occupants, which is released in the event of an impact automatically opening carbon dioxide storage tank is filled.

It has long been used as an occupant protection system for automobiles sought what the occupants were facing in the event of a sudden impact with the vehicle Injury protects. Such a protection system should include at least one Frontal impact speed of 50 km / h provide protection without the vehicle occupants need to take further protective measures, such as wearing seat belts and like that. In the event of a side impact, the vehicle occupants should at least Be protected up to a speed of 25 km / h, and when the vehicle is twice completely overturns up to speeds of about 100 km / h. The protection system should react to various accident situations and the protective measures within of 50 msec unfold.

There is already a vehicle occupant protection system known in which a Pressurized air container, which is under a pressure of 250 atmospheres, in a protective bellows made of nylon fabric is emptied as soon as a thin metal membrane on the air pressure container is pierced.

It is also an electronic sensor that works in all directions available with surplus impact sensing elements.

Another known vehicle occupant protection system is compressed Nitrogen gas is blown into the protective bellows, whereby an electrically ignited explosive charge opens the tubular, high-pressure gas reservoir. The nitrogen gas flows at high speed through a precisely dimensioned opening and a Diffuser into the protective bellows. A sensor is sensitive in one direction used.

In another known vehicle occupant protection system, for A solid propellant is used to generate the filling gas.

However, this must be such that when it is burned no poisonous gas are generated and that combustion is at the lowest possible Temperature takes place to reduce the risk of fire. A solid propellant for generating a suitable gas for inflating the protective bellows a solid coolant, ammonium oxalate, which is used to turn off toxic gases serves, such as hydrogen cyanide, hydrogen sulfide, carbon monoxide, and the like.

The invention is based on the object of an impact protection device for vehicle occupants to create, which without using a high pressure gas container gets by, cannot develop any toxic gases and does not generate any loud noise is working.

This is achieved by filling liquid carbon dioxide in the storage container, through a magnesium fuel set in a chamber, which is connected to a connecting pipe between the storage container and the protective bellows and by an ignition charge for the magnesium burner that can be triggered by an impact sensor.

The invention is described below with reference to schematic drawings an exemplary embodiment described in addition.

Figure 1 is a flow chart to illustrate the operation of the protective bellows according to the invention.

Fig. 2 is a partially sectioned view of the essentials Parts of the device according to the invention.

FIG. 3 is a section along line 3-3 of FIG.

FIG. 4 is a section along line 4-4 of FIG.

FIG. 5 is a section along line 5-5 of FIG.

Figure 6 is a perspective view of the arrangement of the present invention Protective device in the driver's compartment of a motor vehicle.

FIG. 7 is a sectional view taken along line 7-7 of FIG.

Figure 8 is a sectional view corresponding to Figure 7, but after the ignition of the magnesium fuel.

Figure 9 is a perspective view of a cross knife for severing the sealing membrane of the carbon dioxide storage container.

Figure 10 is a perspective view of an accordion-like folded one Protective bellows at the beginning of the filling with carbon dioxide gas.

Figure 11 is a perspective view of an impact sensor.

FIG. 12 is a sectional view of the impact sensor of FIG. 11 with the corresponding protective housing.

FIG. 1 shows an operating diagram of the essential work steps the protection device according to the invention. Box II denotes an impact sensor, which comes into operation when the passenger vehicle in which the sensor is located becomes involved in an accident, causing a severe delay or on the feeler Acceleration works. The impact sensor, such as an electrical switch, closes thereby an electrical ignition circuit, which in turn has a carbon dioxide storage container opens as indicated by Box III.

A short time later, on the order of milliseconds, the magnesium primer is burned exothermically in a combustion chamber, like the box IV shows. Another short time afterwards, also on the order of milliseconds, the liquid carbon dioxide is expelled from the storage container under pressure and comes into contact with the gas in the combustion chamber for the magnesium primer. The heat of vaporization of the liquid carbon dioxide is replaced by the heat of combustion of the magnesium is applied as shown by Box V.

The heated carbon dioxide gas then flows into the protective bellows and fills as shown in box VI. The gas-filled protective bellows then acts as a cushion so that the vehicle occupants are protected from accidents.

Figure 2 shows an automatic protective bellows 1, which is an L-shaped Metal pipe 2 includes. This extends from point A to point B, as shown by arrow 3. The point A is with a metal cover 4 tightly covered. Inside the metal tube 2 is located in the vicinity of the metal cover 4 a storage container 5 for liquid carbon dioxide. This storage container is shown in FIG the metal tube arranged tightly. There is an ignition mechanism on the reservoir 6 attached with a pair of firing wires 7 and 8 extending from the firing mechanism Ç around the side of the storage container and through insulated clamps 9 and 10 in the Rtalldeck 4 up to the series connection of a switch 11 with a battery 12 extend The switch 11 forms a S ra pril *, and the battery 12 is the vehicle accumulator, located on the inner wall of the metal pipe 2 still flame stabilizers 13 and 14 and a pair of mixing diaphragms 15 and 16. The knee 17 of the metal tube goes into a heat exchanger 18, which by means of a flexible Coupling hose 19 connected to a housing 20 containing the protective bellows is. The flexible coupling hose is on the metal tube by means of a clamping ring 30 clamped. The upper half 25 of the housing 20 has a transverse axis 26 around which the protective bellows in the housing 20 is turned over. At the bottom of the case 20 there is a protective channel connected to the flexible coupling hose 19 21, which is shown in dashed lines.

Figure 3 shows in cross section the metal tube 2 at the location of the flame stabilizer 13 and the mixing diaphragm 15, which runs coaxially therewith. The metal pipe 2 has a Diameter D. The flame stabilizer 13 is used to control the pilot flame of the pyrotechnic Keeping the mixture as well as mixing the combustion products with the liquid To bring about carbon dioxide when this flows out of the reservoir 5.

Figure 4 shows the metal tube 2 in cross section at the location of the heat exchanger 18, which fills the cross-section of the metal pipe over a length 27, as in FIG 2 can be seen.

The heat exchanger 18 sits firmly in the clear space of the metal pipe with the diameter D and can consist of a wire screen made of aluminum or copper wire consist of a suitable mesh size. The heat exchanger 18 can also be made of extruded Copper, an aluminum component with a honeycomb-shaped cross-section or a tubular one Cross-section or made of another highly thermally conductive material, which absorb heat quickly and the rapidly flowing gases and liquids can deliver. The heat exchanger 18 can also have an expanded honeycomb shape Structure made of aluminum sheet or the like, as they are usually considered to be pressure-receptive Components of aircraft wings or the like is used. These structure can be made by welding a number of very thin aluminum sheets in linear patterns, this multilayer intermediate stage being honeycomb-shaped is expanded. Other metal alloys with high thermal conductivity can also be used be used. The metal pipe 2 and the heat exchanger 18 can also be made of soft Are made of carbon steel.

With a view to optimizing the heat transfer rate as a function of the cost of the metal pipe and the material of the heat exchanger Steel can be quite economical.

Figure 5 shows a cross-section along line 5-5 of Figure 2, whereafter the housing 20, which is made of plastic, an upper half 25 and a lower Half 22 comprises, which by means of a tearable closure 24 with each other are connected.

The housing 24 has a transverse straight front dividing line 28, caused by the contact of the edges of the upper half 25 and the lower Half 22 of the housing is formed.

The joint 29 permanently connects these two halves of the housing together. In the housing 20 there is an inflatable protective bellows 23, the is folded over about the transverse axis 26 in a U-shape.

The protective bellows 23 has concertina-like folds, as below is still explained.

The breakable plastic hinge 24 is connected to the housing 20, after the protective bellows 23 has been folded and placed in the housing 20. At the The protective bellows 23 is best placed in the lower half 22 of the housing and the upper half 25 is then placed on top, so that both parts are at the dividing line 28 touch, and the frangible plastic hinge 24 is then welded to the housing 20, so that both housing parts are firmly connected to one another. The breakable plastic joint 24, which can be completely sealed over the entire length of the transverse axis 26, consists of a cast part with an incorporated groove, which is a possible Breaking point forms. The material used for the breakable plastic joint is suitable a plastic with high notch impact sensitivity, such as polystyrene.

Figure 6 shows the arrangement of the automatic protective bellows 1 in one Motor vehicle. The metal tube 2 is located below the instrument panel 60, the metal pipe 2 being close to the partition wall 61 to the engine compartment. The front seat of the motor vehicle is denoted by 62. The housing 20 for the actual protective bellows is also below the instrument panel, with the dividing line 28 parallel to and near the instrument panel. The upper half 25 of the Housing 20 is firmly connected to the instrument panel. The protection channel 21 for the flexible membrane tube in the housing 20 lies on the underside of the lower half 22. The housing 20 is as close as possible in front of the seat 62 so that the Protective bellows 23 unfold in a minimal time when triggered by the sensor can. The flexible coupling hose 19 results in a flexible connection of the fixed arranged housing 20 and the other fixed components of the automatic Protection system, which are located in the metal pipe 2.

According to FIG. 2, the metal tube 2 lies in one plane, as shown in FIG 6 0 can be seen. However, it can also be turned by 90, so that the storage container 5 reaches a vertical position in which either the metal cover 4 is down shows and runs in the vicinity of the ground, or directly above the ignition mechanism 6 is below the higher reservoir 5. In this case, liquid arrives Carbon dioxide when the sealing membrane 72 breaks out of the storage container.

In other positions of the storage container 5 more or less arrives liquid carbon dioxide directly out of the storage container, depending on the angular position same.

Construction details of the ignition mechanism 6 and the storage container 5 are shown in FIG. The internally threaded neck 70 of the reservoir 5 has a threaded insert 71. This threaded insert carries a seal serving me allene closure membrane 72, which the interior 73 with the therein located liquid carbon dioxide. The closure membrane 72 is by means of a threaded ring 74 pressed against the threaded insert 71 under pressure. This opens the opening 94 of the storage container closed. In the neck 70 of the reservoir is present the closure membrane 72 a cross knife 75. A knife guide serving at the same time Spacer ring 77 is attached to the neck 70 and guides the cross knife 75. On this is at one end a disc 76 which is in the cylindrical cavity of the Spacer ring 77 is displaceable. In the interior 82 of the spacer ring 77 is located an ignition charge 78 enclosed by a sealing plug 79. This Sealing plug is threaded and up to spacer ring 77 in screwed the neck 70, so that a free space for the primer 78 is created and this cannot decompose prematurely. From the ignition charge 78 carry out Insulators 80 and 81 ignition wires 7 and 8 to the outside to the ignition circuit. To the Neck 70 of the reservoir 5 are a pair opposite one another metal knee housings 83 and 84. There can also be several such knee housings in be attached in a radial plane around the neck. These knee housings are with a magnesium burner 85, 86 filled, for example with magnesium powder, as it is for photographic Purposes. The knee housing 83, 84 are so large that they have the required Can absorb amount of magnesium. Each knee joint has a pair of very thin closure membranes B7 and 88 or 89 and 90, to prevent the magnesium fuel from falling out. The openings 91 and 92 of each knee housing each lead into the cavity 93 in the Area of the cross knife 75. The exact structure of the ignition mechanism 6 is shown in FIG 7, in which the ignition mechanism is shown in the not yet triggered state is. All components of the protection system between lines A and B (see arrow 3) should be made of metal provided that the system can be easily grounded except where electrical insulators are required.

FIG. 8 shows the ignition mechanism 6 after the ignition charge has burned off 78, the burnt-out primer being designated 78 '. This takes practical still occupies the same space in the interior 82, however, the cross knife has 75 now pierced the thin sealing membrane 72 so that the interior 73 of the Reservoir is no longer closed. The pierced sealing membrane 72 'can be seen with their bent quadrants on the left side of the opening 94.

The primer 78 has both high pressure gas as it burns also creates a flame, the high pressure pressing on the disc 76 and the Movement of the cross knife to the left caused by the closure membrane 72. By the high pressure and the flame of the primer 78 are the sealing membranes 87, 88, 89 and 90 of the Kniegehäuae 83 and 84 have been destroyed, so that the one located in this Magnesium powder is ejected from the knees and ignited. The magnesium burns in the oxygen of the air existing in the metal pipe 2. To get a full To ensure combustion, the diameter D of the metal pipe is chosen so that there is enough oxygen to burn all the magnesium. That Magnesium powder is in the direction of arrows 96 and 97 under the action of high Pressure ejected.

For the sake of clarity, the areas 30 and 17 of FIG. 2 are designated as the combustion chamber for burning the magnesium. The flame stabilizers 13 and 14 are arranged in such a way that they support mixing of the substances that react with one another and ensure complete combustion. The combustion can also be carried out without flame stabilizers. However, these reduce the required length and volume of areas 30 and 17. The combustion can also continue into the heat exchanger 18. The combustion of magnesium takes place according to the reaction: In addition, magnesium ignited in air can react with carbon dioxide according to Equation 2 below: The fact that carbon dioxide reacts with magnesium is important for rapid evaporation of the liquid carbon dioxide which emerges from the storage container 5 under pressure.

When the protection system is triggered, the carbon dioxide does not dampen the Oxidation of the magnesium, since reaction 2 is also exothermic. Although the heat of reaction according to equation 2 is smaller than that according to equation 1, it is large enough to to contribute sufficiently to evaporation. To increase the reaction 2 can additionally Magnesium can be added to the ignition mechanism 6.

Typically 500 grams of liquid carbon dioxide relax (vapor pressure P = 65 bar at 250 C) to 280 dm3 at this temperature and a pressure of one Bar. The amount of heat required to vaporize the liquid carbon dioxide is achieved by burning 2> 47g magnesium powder in 1.22 liters of oxygen in the Air of the metal pipe. To avoid excessive temperature rise in the same and to ensure effective heat transfer during evaporation a heat exchanger can be provided. The combustion of magnesium powder can be speed up by using a fine powder and mixing blends to get the To increase turbulence during the combustion process. Which are different Ambient temperature of the storage container changing heat of vaporization of the liquid Carbon dioxide can be compensated by using a larger than the theoretical one necessary amount of magnesium. Further losses during the combustion process and in heat transfer can be avoided in the same way.

FIG. 9 shows a perspective view of a cross knife 75 with four individual thin knives arranged at right angles to each other. The single ones Knives each have a shoulder 100 that is on the threaded ring 74 at the contact surface 95 rest. The disc 76 is circular and fits snugly, however without excessive friction in the interior 82. Of course, other cutting blades can also be used be used. The shoulders 100 serve as stops to limit movement of the cross knife 75 after ignition of the ignition charge 78, so that the space 101 between the individual knives the carbon dioxide from the interior 73 of the storage container lets escape.

FIG. 10 shows the beginning of the deployment of the protective bellows after the beginning the combustion in the knee 17, the heated gas passing through the heat exchanger 18 and the flexible coupling hose 19 flows into the protective bellows 23. A flexible one Membrane tube 110, which originally lies in the protective channel 21 of the housing 20, fills with carbon dioxide gas under pressure. The flexible membrane tube 110 expands now extends to its full length and opens the housing by bursting the plastic hinge 24. The U-shaped folded protective bellows is also inserted through the membrane tube 23 unfolded and pushed out of the housing 20 by the pressure of the carbon dioxide gas. The folds fill first at the front 112 near the flexible membrane tube 110. The folds 113 further back are filled last. Depending on exact weight of the filling in the storage container 5 is the protective bellows 23 within a few milliseconds after actuating the switch 11 bulging with a small Overpressure. By providing a required amount of magnesium in the magnesium fuel the liquid carbon dioxide can be converted into carbon dioxide gas at ambient temperature of Vaporize at 20 to 330 C at a low pressure of 0.5 to 1 bar. The inflated Protective bellows 23 has a length 114, which is used to protect 1, 2 or 3 occupants of the motor vehicle sufficient, depending on the requirements. The height 115 of the inflated Protective bellows should be large enough to protect people effectively, preferably 30 to 60 cm. The transverse axis 116 of the protective bellows around which it is folded over in a U-shape is shown in Figure 10 for illustration.

The protective bellows 23 consists of a non-flammable, thin and flexible one Plastic material, such as PVC, which contains a non-flammable plasticizer, or of a non-woven fabric with a thermoplastic binder. Of the Protective bellows can be produced in the usual way in a blow molding process.

When using non-woven fabrics, such as a non-flammable one thermoplastic fiber structure, such as Dynel, the protective bellows can correspond to a Pattern can be cut out and welded.

FIG. 11 shows the impact sensor which is sensitive in one direction 120, which is attached to a component 121 of the motor vehicle. A coil spring 122 fits snugly, but slidably around an insulating spigot 123 made of a material low coefficient of friction. The insulating pin has a rounded end 124 on. The insulating pin 123 consists for example of polytetrafluoroethylene or other polyfluoropolymers that have a low coefficient of friction as well sufficient hardness to prevent cold flow and deformation under the conditions of use of the impact sensor. A contact rod extends through the insulating pin 123 131, the end 125 of which is at the apex of the curved end 124 of the insulating pin lies. The contact rod extends through an insulating plate 126.

The free end 127 of the coil spring 122 carries a metal weight 128, which is firmly connected to the coil spring and directly over the end 125 of the contact rod 131 is at a distance. The mass M of the metal weight 128, the distance G of the same to the end 125 and the length L of the insulating pin 123 as the pitch P between the individual turns of the coil spring 122 and the spring stiffness determine the size of the deceleration or acceleration at which the contact of the Impact sensor closes.

An annular groove 129, which receives a dust protection housing 132, is located coaxially around the insulating pin 123. The impact sensor acts as a seismic pendulum with a period of FIG. 12 is a cross section through the impact sensor 130 according to FIG. 11. It can be seen that a flange 133 of the dust protection housing 132 lies in the annular groove 129 and is screwed tightly against the insulating plate 126 with a ring 134. The electrical connections 135 and 136 form ends of the coil spring 122 and

of the contact rod 131. These connections can be designed in the usual way and treated to prevent contamination and short-circuiting. A Such an impact sensor can be permanently behind bumpers, in doors or the like to be appropriate.

To protect the fuel tank, another one can be placed near it Protective device with a second carbon dioxide storage container 5 and an ignition mechanism 6 "should be provided.

An impact sensor 130 can also be in the rear of the vehicle be attached, for example in the area of the rear bumper. This impact sensor can be used to operate the ignition mechanism 6 "to protect the fuel tank, so that the fuel flowing out when it breaks does not ignite or ignited fuel is extinguished.

The protective device according to the invention is particularly suitable for automobiles, trucks and other road vehicles involved in accidents could become. However, it can also be used for fast motor boats and aircraft or the like use, the impact sensor according to the possible Accidents can be appropriate.

To ensure safe operation of the protective device this should be designed as a single use disposable system. For the purpose it can be designed as a sealed unit, for example with a seal over the metal cover 4, the seal clearly indicating whether the device is still operational is. After an accident, the reservoir 5 and the ignition mechanism 6 to Refill sent to factory. smoke the protective bellows 23 can be used for a Be designed for single use and then together with the housing after a single use Discarded use, the fragile plastic hinge 24 preventing the housing can be used again.

In this way, a high level of user security is guaranteed. If necessary, a new protective bellows with housing can be installed in the vehicle. the Protection device according to the invention is designed so that any improper Easily identify interventions during an inspection.

Claims (21)

Claims Protection device for vehicle occupants, with an inflatable protection device for vehicle occupants, with an inflatable protective bellows, with one with the protective bellows connected carbon dioxide storage tank that opens automatically in the event of an impact, G e k e n n n z e i c h n e t d u r c h a filling of liquid carbon dioxide in the storage container (5), through a metal fuel in a chamber (23, 84), with a connecting pipe (2) between the storage container (5) and protective bellows (23) is in connection, and by an ignition charge triggered by an impact sensor (20) (78) for the metal fuel. 2. Apparatus according to claim 1, d a d u r c h g e k e n n -z e i c h n e t that a magnesium fuel is used as the metal fuel. 3. Apparatus according to claim 2, d a d u r c h g e k e n n -z e i c h n e t that the magnesium fuel contains magnesium powder. 4. Apparatus according to claim 1 to 3, d a d u r c h g e -k e n n shows that at least one chamber (83, 84) in the area of the neck (70) of the storage container (5) opens, and that the mouth of the primer (78) containing space (82) is adjacent. 5. Apparatus according to claim 4, d a d u r c h gek e n n -z e i c h n e t that at least one chamber designed as a knee joint (83, 84) is radial opens onto the neck (70). 6. Apparatus according to claim 4 or 5, d a d u r c h g e -k e n n z e i c h n e t that the interior (82) containing the ignition charge (78) is replaced by a Piston (76) is limited, which is in communication with a knife (75), which in front of a sealing membrane (72) of the storage container (5). 7. Apparatus according to claim 4 to 6, d a d u r c h g e -k e n n z e i c h e t that the metal fuel can be replaced by thin sealing membranes (87, 88, 89, 90) is included. 8. Apparatus according to claim 6 or 7, d a d u r c h g e -k e n n shows that the knife has at least one stop shoulder (100), which limits the penetration movement of the knife and a flow connection between the interior (73) of the storage container and the mouth of the chamber (83, 84) guaranteed. 9. Apparatus according to claim 4 to 8, d a d u r c h g e -k e n n z e i c h n e t that the storage container (5) is in one end region of the connecting pipe (2) is housed and that this end area is tightly closed by a cover (4) is. 10. Apparatus according to claim 5 to 9, d a d u r c h g e -k e n n z e i c h n e t> that the exposed front ends of the knee housing (83, 84) in show the direction of flow of the carbon dioxide gas in the connecting pipe (2). 11. The device according to claim 1 to 10, d a d u r c h g e -k e n n z e i c h n e t that in the direction of flow behind the metal combustion set at least a mixing device is located. 12. The device according to claim H1, d a d u r c h g e k e n n -z e i c h n e t that the mixing device; doÕ as an aperture educated is. 13. The apparatus of claim 1 to 12, d a d u r c h g e -k e n n z e i c h n e t that a heat exchanger (18) housed in the connecting pipe (2) is. 14. The apparatus of claim 1 to 13, d a d u r c h g e -k e n n z e i c h n e t that the connecting pipe (2) forms an L-shaped metal pipe. 15. The device according to claim 1 to 14, d a d u r c h g e -k e n n notices that the connecting pipe has a flexible coupling hose (19) is in communication with the inlet of the protective bellows (23). 16. The device according to claim 1 to 15, d a d u r c h g e -k e n n show that the protective bellows (23) has accordion-like folds and is U-shaped is folded. 17. The apparatus of claim 16, d a d u r c h g e k e n n -z e i c h n e t that the folded protective bellows in a flat, two-part Housing (20, 22, 25) is housed that the two parts of the housing through a frangible hinge (24) are sealed together, and that the two Housing parts lie on top of one another along a dividing line (28). 18. The apparatus of claim 17, d a d u r c h g e k e n n -z e i c h n e t that the frangible hinge (24) is designed so that it is the two Holds housing parts (22, 25) together in the standby state along the dividing line. 19. The apparatus of claim 16 to 18, d a d u r c h g e -k e n n z e i c h ne t that at the inlet of the protective bellows (23) an incombustible, expandable Gas inlet pipe (21) is provided which is in communication with the connecting pipe (2) stands. 20. The device according to claim 1 to 29, d a d u r c h g e -k e n n notices that an electric ignition charge (78) is used as the ignition charge and that the impact sensor closes on acceleration or deceleration electrical switch (11) is. 21. The device according to claim 20, d a d u r c h g e k e n n -z e i c h n e t that the impact sensor (120) has an insulating pin (123) to which is a coil spring (122), one end of which is attached to an insulating plate (126) rests and at its other end carries a metal block (128) that the Insulating pin (123) is traversed by a contact rod (131), which on the free The end of the insulating pin leads to the contact rod (131) and the helical spring (122) form the two contact connections (136> 135) of the impact sensor, and that the insulating pin, the coil spring and the metal block from a protective housing (132), which is fixed in the insulating plate (126).