Gasgenerator.

The invention relates to a gas generator according to the preamble of claim 1. The principle of this gas generator is known from Automobiltechn. Newspaper Volume 84 (1982) pp 77 and 78 known.

There are already known tubular inflators for the passenger side, but where Anzünd-, fuel and filter chamber, radially downstream, extend over the entire length of the gas generator. The large chamber walls are unnecessarily exposed to high pressure loads, which must be compensated by higher material costs. The only radial gas guide give more unfavorable conditions for a particle-secreting deflection of the gases and the use of an expensive filter material over the entire length of the gas generator.

The arrangement also has the disadvantage that when changing the power requirements, that is, varying the propellant charge amount, not only the combustion chamber, as in the new invention, but all other parts, such as the Anzündanordnung and the filter parts, also have to be changed.

An elderly tubular gas generator design is shown in the patent DE-PS 23 30 194th but this approach has the disadvantages that the supported from the two outer, verschreubten lids leg guides and bottom panels not only has a limited strength, but also an insufficient tightness of the outer housing result. For this reason, the combustion chamber has been arranged separately within the outer casing, which entails considerable complications and very large dimensions with them.

Disadvantages of previous solutions: Known systems have the drawback that they consist of two gas generators with two igniters, associated cables and connectors and also require a dual power amplifier in the sensor. Charges-disadvantages the size of these systems is connected with integration difficulties in the vehicle.

Object of the invention is to provide a gas generator, which can be produced with little effort and high functional reliability.

The solution of the invention is included in the identity of the patent claim 1.

An essential feature of the invention, and also important advantage is that the gas generator of several cup-shaped sheet metal parts positively to a production-ready and in terms of strength optimal, substantially tubular modular total housing or assembled cohesively, wherein the high pressure is acted upon combustion chamber is formed about boiler-shaped, with axially arranged filter chamber forms the shell of the inflator overall housing and a Anzündeeinrichtung contains approximately centrally arranged in a cup-shaped peripheral (radial) and with openings LABEL FOR housing is accommodated, which is attached to the inflator casing.

Further advantages of the invention: The demarcation of the three pressure chambers, each with the smallest possible space in pressurized Anzünd-, fuel and filter chamber in axial arrangement. This cheapest gas guidance, strength, weight and size. Also adaptable modular system with favorable production conditions. The axially extending gas guide allows limiting the expensive filter material on the length of the filter chamber.

An integral connection of cup-shaped parts ensures optimal tightness and thus the best conditions for secure storage of the chemical components and for long-term functional reliability. Moreover, deliberate attacks are largely prevented.

An embodiment of the invention is explained in the following description, without the invention being limited thereto. Modifications are possible to the skilled artisan. The invention also includes all combinations and sub-combinations of the features described and claimed shown.

In the accompanying drawings, purely schematically:<ul><li>Fig. 1 shows the gas generator in the assembled state (without a filter inserts),</li><li>Fig. 2 is an exploded view prior to assembly,</li><li>Fig. 3 is a joint connection of parts of the gas generator according to the electron beam or laser beam method,</li><li>Fig. 4 shows a joining connection by welding, shrinking, or gluing,</li><li>Fig. 5 shows a joining connection by crimping or of headers or alternatively shrinking or gluing,</li><li>Fig. 6 is a joining connection by crimping or rolling,</li><li>Fig. 7 is a joining connection by friction welding on one side,</li><li>Fig. 8 is a joining connection by friction welding on both sides of a wall,</li><li>FIG. 9 is a joint connection by means of screws and securing, </li><li>FIG. 10 is a joint connection by beads and rolls (roll-bonding method).</li></ul>

Referring to FIG. 1, the gas generator has a gas generation chamber 1 and at least one preferably two filter chambers 2 and 3, these main parts are made of sheet metal and assembled into a substantially tubular cylindrical assembly, as shown in Fig. 1. Further details are apparent from the following description.

In Fig. 3 the modular structure of the gas generator from its assembly can be seen. In Fig. 1 and Fig. 2 is not shown, the filter elements are as known per se (cf.. Entrance called Automobiltechn. Journal). The said main parts 1 to 3 are performed in sheet metal construction, with the use of sheets has already been described in German Auslegeschrift 29 15 202 of the applicant. The thin sheets described therein are also applicable here, as well as the propellant charges, detonators etc ..

The invention differs from the prior art essentially by the novel construction and assembly. The gas generating chamber 1 contains the propellant charge and the detonator or ignition unit 4 for electrically initiating an ignition of the squib of the propellant from the outside, in particular when a sensor circuit has encountered a crash situation, for the purpose of inflation of the protective cushion.

In the invention, the gas generating chamber 1 forms the center of which is detached. It consists of the parts 1a and 1b which are unequal to permit manufacturing advantages, in particular during welding. The filter chambers 2 and 3, so that the filter chambers are arranged in 2 or 3 in the axial direction of the main axis (longitudinal axis) of the gas generating chamber 1 joined to the central gas-generating chamber. The gas generating chamber 1 contains the pyrotechnic propellant charge and compressed gas developed, when an ignition pulse is obtained from the outside of the centrally but offset by 90 ° to the longitudinal axis of igniter disposed 4th The pressure gas is flowed through by the nozzle openings 10 in the nozzle plates 1c to the one or more filter chambers 2/3, swirled thereby and is deflected, in which it leaves the longitudinal slots 20, 30 in the filter chambers 2, 3 peripherally (radially), the with apertured peripheral wall outlet of each filter chamber to coat the inflator housing forms, which is connected to the protective device.

In the invention, the main parts are joined together to form a cylindrical unit. The main parts are cup-shaped and the cups or pots are joined in the area of ​​the circular surfaces (nozzle plates or disks) to each other. These circular areas are the end faces. The another addition can areally, linear manner or done by many points, either peripherally or distributed over the circular areas, depends on applied joining methods and joining means and materials to be joined.

In the gas generator of the invention, the gas generating chamber will form the central module and the filter chambers 2, 3 are attached to this with their end faces, so that the extended main axis of the part 1 forms the major axis of the parts 2 and 3. FIG. The nozzle plates or disks which can be flat or curved run, are of such a number of nozzles, which are selected according to the desired flow, both according to number, size and distribution by the skilled worker, that is, when a stronger turbulence is desired, and in particular increasing their number will. The gas generating chamber 1 is only composed when the propellant is filled. The same applies to the filter chambers 2 and 3 with respect to the filter. The filter chambers 2 and 3 are then added symethrisch to the gas generating chamber 1, specifically symethrisch relative to the center axis of the igniter 4, which in turn forms a 90 ° angle to the principal axis of the cylinder, however, centrally within the assembled gas generating chamber, is arranged precisely centrally in Example , The igniter is also positioned as such in a cup-shaped housing and this cup-shaped housing 4b is firmly and tightly inserted to the sheet metal casing of the gas generating chamber. 1 The pressure generating chamber 1 has the greatest wall thickness, Weil she is the highest pressure-loaded and the parts 2 and 3, a smaller wall thickness than part. 1

The parts of the gas generator are made - as is known - from sheet metal and preferably from the same or similar materials, but in particular, include compatible materials.

As proven particularly suitable, the following joining methods have: electron beam welding, laser welding, friction welding, shrinking, gluing metal known adhesives such as from the aerospace industry, because there the same or similar metallic lightweight materials are used. can be used also a beading or of headers or rollers (roll-bond method) and the screws and securing (sealing case).

It is essential that this corrosion-resistant materials are used, because of the chemical aggressiveness of the propellant charge and that the materials used are performed in such a thickness that they can withstand the applied pressure loads. The additional requirement is the absolute tightness of the joints.

The skilled person will therefore especially safety but make his choice among these foregoing even after manufacturing and economic aspects, in particular as regards the applicable joining process. He can of course combine different joining methods with each other, ie, joints, lines or surfaces between the mating parts not only by the same process together (all) but also by various methods.

In Figs. 3 to 10 each joining process are shown purely for example, based in each case a single joint between main parts 1, 2, 3 in detail without a special explanation is needed for this purpose.