MXPA97010050A - Gas generator for air bag systems, which has a particle separator for centrif force - Google Patents

Abstract

The present invention relates to a gas generator, in particular for inflating an airbag that serves for the protection of passengers in a vehicle, with a cargo container in which a gas-generating material is arranged, an element of electric ignition to ignite the gas-producing material, a centrifugal chamber that is formed as a particle separator by centrifugal force and a dip tube placed on the axis of symmetry of the centrifugal chamber and extending therein, through that tube the flow of purified gas reaches the air bag by means of the desalted flow chamber, which is characterized because: the loading container, the ignition element, the centrifuge chamber, the immersion tube and the outlet chamber of flow are placed on a common axis of symmetry and the centrifugal chamber, the immersion tube and the flow outlet chamber form a structural part to which the loading vessel, with the elem ignition, it is coupled by the middle of a connecting element.

Description

GAS GENERATOR FOR AIR BAG SYSTEMS, WHICH HAS A PARTICLE SEPARATOR FOR CENTRIFUGAL FORCE The invention relates to a gas generator, in particular for inflating an airbag that serves to protect the passengers of a vehicle, in accordance with the preamble of claim 1. The combustion of gas charges in The form of slag in the gas generators for air pockets produces, in addition to the gases, solid substances that move in a liquid or gaseous state. In order to prevent these substances from condensing and arising from the gas generator, resulting in the destruction of the airbag, the flow of gas and particles must be guided in the generator in such a way that the condensation of the Solid or liquid substances is carried out inside the generator. From US Pat. No. 4,084,839, a generic type gas generator for inflating air pockets is known which serves for the protection of passengers inside a vehicle, in which an ignition element and the gas generating material they have inside a housing or structure. The ignition of the gas-generating material by means of the starting element or emitter, the gas and the particle flow arrive in a centrifugal chamber in which the separation of particles is carried out by means of a centrifugal force. The flow of purified gas reaches the air bag by means of an immersion tube placed centrally, inside the centrifuge chamber. A disadvantage of this gas generator is the incomplete purification of the particle and gas flow. The underlying objective of the invention is to improve the gas generator according to the preamble of claim 1, with respect to an optimal purification of the gas and particle flow. Moreover, the gas generator has a simple construction, with a reduced structural volume. This object is achieved in accordance with the invention by the characteristic aspects of claims 1 or 10. The preferred construction form according to the invention is characterized by the charging container, the ignition element, the centrifugal chamber, the The immersion and flow outlet chamber are arranged in a common axis of symmetry and the centrifuge chamber, the immersion tube and the outflow chamber form a structural part to which the loading container, with the ignition element, it is coupled by means of a connector element.

By means of this form of construction, the optimum purification of the gas and particle flow is achieved, with a low structural volume and a simple construction. Advantageously, the coupling is carried out by means of a lock washer. This has the advantage that completely assembled gas generators can be opened, at no cost, by separating the sealing washer. This is necessary if, for example, the pyrotechnic structural groups such as the ignition element or the charging container have to be changed. In a preferred form of construction, the connector element has a passage that is connected on one side as in the predetermined rupture or opening position of the container of the load and on the other hand, with the distribution chamber that connects the connector element, with the distribution chamber that has openings in the direction of the centrifugal chamber. In order to prevent a leakage of the gas loading tablets that have not completely reacted as the material producing the gas, a separator in the form of a wire mesh placed in the cargo container or in the distribution chamber is provided. the way of gas flow. In the preferred construction form, the openings of the distribution chamber are connected to an annular chamber around, partially, the centrifugal chamber, with a peripheral wall of the centrifugal chamber having opening slits in one or more positions in the total or partial width of the same and that it turns inwards in such a way that it produces a tangential flow, positive, in the centrifugal chamber for the gas flow. Conveniently, the ends of the slit of the centrifuge chamber overlap. An alternative form of construction is characterized in that the distribution chamber is connected directly to the centrifugal chamber by means of 2 openings, wherein the centrifugal chamber consists of 2 spiral-shaped channels and each opening is connected to a channel. By means of this spiral guide of the gas and particle flow, with a constant flow velocity the angular velocity increases towards the center and it results, that the separation of particles from the low mass becomes possible in the walls of the the gas chamber. Poor particle zones, in the center of the centrifugal chamber, the gas flow is conducted through the immersion tube into the flow outlet chamber. For additional cooling and fine particle separation, the dip tube can be designed as a spiral (like a cooling coil). Advantageously, the cooling elements such as, for example, wire meshes are placed in the flow direction of the openings in the annular chamber and / or in the flow outlet chamber. It is an advantage if a surface or bags of rough material are placed on the walls of the centrifugal chamber or in the spiral channels. This can be achieved through the application of lattices or sheets or perforated sheets. This results, particularly with a low flow rate, that the separation of particles from a main stream is further promoted due to the separated or retained particles on the surface or rough sacks, lattice or perforated sheets. An alternative form of construction according to the invention is characterized in that the centrifugal chamber, the flow outlet chamber and the immersion tube are placed through a tube, and in the tube, it is connected at least in a passage or conduit. tangential that goes towards the centrifugal chamber which is connected with a pressure element. The material that produces the gas is accommodated in the pressure element. This form of construction can actually be produced at a low cost and has an extremely small construction volume. Advantageously, the pressure element is integrated in a fixed part screwed into the tube. The pressure element can be easily changed with this form of construction. A special form of construction is characterized in that the tube containing the two gas generators are placed in the manner of a mirror image. In all forms of construction, the ignition element is advantageously integrated in a loading container or in the pressure element. Other characteristics of the invention are seen in the figures described below, in which: Figure 1, b show a gas generator with a normal centrifugal system, Figures 2a, b show a gas generator with a spiral centrifugal system, Figures 3a, b, c show 2 gas generators placed in a tube in the form of a mirror image and Figures 4 shows a spiral-shaped immersion tube. Figures la, b show a gas generator in 2 sections according to the invention, which consist of 2 modules or construction parts. In a first module, the loading container 3, an ignition element 1 and a charge producing the gas 4 are placed in the form of gas loading tablets or pellets. The loading container 3 comprises a cylindrical housing 36, the ends of which are arched.

The ignition element 1 is thus used in said arcs, such that in the external position for the ignition flame of the ignition element 1 either exposed to the predetermined breaking position 2 in an arch of the housing cylindrical 36 of the loading container 3. This is closed by means of a cover for the loading container 5 at the end of the loading container 3 opposite the ignition element 1. A separation in the form of wire mesh 8 is placed similar to the cover in front of the cover of the cargo container 5. Between the separation in the form of wire mesh 8 and the ignition element 1 the charge producing the gas 4 is placed. With the aim of locating the gas production load 4 , a volume adjuster 37 consisting, for example, of a wire mesh is placed between the wire mesh spacing and the load produced by the gas 4. To fix this, the load container 3 is inserted into a sleeve from cylindrical shape 38 on the front end of which the connecting sleeve 39 of the ignition element extends. The jacket 38 and likewise the loading container 3 are secured to the connector element 7 by means of a closure clamp 28. A conduit or passage 6 is inserted, centrally in the connector element 7. The cover of the loading container 5 is place in this position with a predetermined breaking position 29. Upon activation of the electric ignition element 1 by means of the connector sleeve 39, the flame or the ignition flame is produced in the ignition element 1 which penetrates the predetermined breaking position 2 of the cylindrically shaped housing 36 of the charging container 3 and which ignites the gas producing charge 4. The gas and particle flow produces a flow through the separator in the form of a wire mesh 8 and penetrates the predetermined breaking position 29 in the cover of the cargo container 5 and reaches the distribution chamber 30 which will be described below, by means of a passage 6 in the connector element 7. With the order of evit In a flow of gas-filled tablets, without completely reacting, the separator in the form of a wire mesh 8 is inserted into the loading container 3. The width of the wire mesh is essentially less than the size of the loading tablets. gas. As a result of the formation similar to a cover of the separation in the form of wire mesh 8, there is a larger wire mesh surface in the particle flow and hot gas which would not be counted if the separation in shape of wire mesh 8 was attached to duct 6 directly. The erosion of the wire cloth is avoided as a result of the above. In the second module or construction part of the gas generator, a centrifuge chamber 25 and a dip tube 18 extending therein are placed by means of a flow of purified gas reaching the outlet flow chamber 27 and from there, the air bag that is not shown. The charging container 3, the ignition element 1, the centrifugal chamber 25, the immersion tube 18 and the outlet flow chamber 27 lie, moreover, on a common axis of symmetry 26. This second part or building module it consists, like the first module, of an externally equal cylindrical jacket, which is secured to the connector element 7 together with the cylindrical sleeve 38 of the first construction part by means of a closure clamp 28. The safety of the closing clamp 28 takes place by means of a formation. The bell-shaped baffle 10 is placed in the second construction part in front of the passage or conduit 6 in such a way that a distribution chamber 30 is created 30. On the edge of the baffle 10 or distribution chamber 30, openings 12 are placed, which open towards the annular chamber 13 which surrounds the centrifugal chamber 25. In front of the openings 12 and of the annular chamber 3 the cooling elements are placed 11., 14, such as wire mesh. The peripheral wall 16 of the centrifugal chamber is here separated at a position above the total width of the centrifugal range 25 and thus arches directly such that an internal groove 15 is produced, wherein the two ends overlap. As a result of this, a tangential flow within the centrifugal chamber 25 is positively formed for the gas flow. The baffle 10 and the reinforcing element 9 form the front end of the centrifugal chamber. The reinforcing element 9 has a dip tube 9 which passes through the middle and extends at one end towards the centrifugal chamber 25 and at another end towards the outlet flow chamber 27. The flow of gas reaches the chamber flow outlet 27 by means of the openings 19 distributed in the periphery of the immersion tube 18 and from which through the openings 22 in the cylindrically shaped jacket 40, arrive at the air bag which is not shown. Similarly, the cooling elements 21, such as for example the wire mesh, are arranged in the front part of the openings 22. After the flow of particle and gas has flowed through the passage 6 in the connecting element 7, to the distribution chamber 30 and from there, through the openings 12, to the annular chamber 13. The flow of gas and particle is finally precipitated, by means of the internal groove 15, tangentially towards the centrifugal chamber 25 and is established a rotation. Centrifugal forces act on the particles and force them to deposit on the inner walls 17 of the centrifugal chamber. Basically, the gas and particle flow are guided in such a way that the centrifugal forces acting on the solid or liquid particles are greater than the forces of resistance of the flow of the same. In a poor zone of particles in the center of the centrifuge chamber 27, the gas flow is divided through the immersion tube 18 by means of an outlet flow chamber towards the air bag. The gas generator according to the invention is constructed in a modular structural manner from parts of thick metal sheets and simply a turning, die-cutting or forging of the parts is carried out. Figures 2a, b show an alternative form of construction of the gas generator according to the invention. An alternative is to have the separator in the form of wire mesh 8 integrated in the loading container 3 in the distribution chamber 30. This construction form is also obviously useful for the construction form in Figures la, b. In contrast to the formation of the centrifugal chamber as a normal centrifugal system in Figures 2a, b, the centrifugal chamber is formed in a spiral centrifuge. Additionally, the centrifugal chamber is formed as a cast component. The openings 12 are each connected to an elongated passage 31a, 31b (see Figure 2b) of each of these longitudinal passages 31a, 31b which are connected to the spiral-shaped channel 32a and 32b wound in a spiral shape. As a result of these spiral-shaped channels, the lower mass particles are separated until, with a constant velocity flow, the velocity angle is increased towards the center, ie towards the dip tube 18, as a result of this, the particles separate in the walls of the most external gas channel. With this form of construction, the immersion tube 18 extends into the centrifugal chamber 25 and fills the axial length of the centrifugal chamber to approximately 80%. The construction form according to Figures 2a, 2b is identical to Figures la, Ib in such a way that the reference numbers also denote similar objects. Figures 3a-c show a construction form in which the centrifugal chamber 25, the outlet chamber 27 and the dip tube 18 are placed in a tube 33. For the inlet the flow of gas and particles, is placed in the tube 33 at least one tangential passage 34 that connects with. the pressing element 43. The pressing element 43 is, for this purpose, integrated in a fixed part 35 connected to the tube 33. Incorporated in the pressing element 43 is the gas producing material, the cooling elements and the element of ignition, such that the pressure element 43 forms a "relatively small" gas generator. The securing part 35 consists of 2 parts that are connected to each other by means of the screws 20. The tube 33 is directed between the 2 parts of the fixing part. The cleaning of the gas and particle flow is carried out according to the "normal spin" principle shown in Figures la, b. The immersion tube 18 is inserted into a separate wall 23 which is connected by means of the screws 24 to the tube 33. At this end, the tube 33 is closed in the gas form by means of connectors 41 which are screwed into the pipe 33 with a seal 42. Figures 3a, b show especially an advantageous construction in which tube 33 contains 2 gas generators constructed in the form of a mirror image. This form of construction is suitable, in particular, for side airbag systems in motor vehicles. Figure 4 shows a special construction form of the immersion tube 18. The immersion tube 18 is formed here (as a cooling coil) for additional cooling and separation of particles.

Claims (15)

1. CLAIMS 1. A gas generator, in particular for inflating an airbag used for the protection of passengers in a vehicle, with a cargo container in which a gas generating material is arranged, an electric ignition element for ignite the gas producing material, a centrifugal chamber that is formed as a particle separator by centrifugal force and a dip tube placed on the axis of symmetry of the centrifugal chamber and that extends into it, through that tube the Purified gas flow reaches the air bag through the flow outlet chamber, characterized in that: the loading container, the ignition element, the centrifuge chamber, the immersion tube and the flow outlet chamber they are placed on a common axis of symmetry and the centrifugal chamber, the immersion tube and the flow outlet chamber form a structural part to which the loading container, with the ignition element, is Coupled by the middle of a connector element.
2. 2, A gas generator according to claim 1, characterized in that the coupling is carried out by means of a closing washer.
3. A gas generator according to claim 1 or 2, characterized in that the connector element has a passage or conduit that on one side is connected to a predetermined rupture position of the loading container and, on the other hand, connects to the distribution chamber connected to the element of a connector, with "the distribution chamber having openings in the direction of the centrifugal chamber 4.
4. A gas generator according to claims 1 to 3, characterized in that The container or in the distribution chamber is provided with a separator in the form of a wire mesh placed in the path of a gas flow 5.
5. A gas generator according to claims 1 to 4, characterized in that the openings of The distribution chamber is connected to an annular chamber, which coaxially surrounds the centrifugal chamber 6.
6. A generator according to claim 5, characterized in that the peripheral wall of the the centrifugal chamber separates into one or several portions in the total or partial width thereof and bends inwardly such that a tangential entry of the flow into the centrifuge chamber occurs.
7. A gas generator according to claims 1 to 4, characterized in that the distribution chamber is connected by means of 2 openings directly to the centrifugal chamber, wherein the centrifugal chamber consists of 2 channels wound in the form of a helix and each opening connects to a channel.
8. A gas generator according to claims 1 to 7, characterized in that the cooling elements, such as, for example, wire meshes are placed in the flow direction in front of the openings and / or in the annular chamber and / or in the chamber of flow output.
9. A gas generator according to claims 1 to 8, characterized in that the walls of the centrifugal chamber or of the spiral-shaped channels have a rough surface or pockets.
10. The gas generator according to claims 1 to 9, characterized in that the perforated lattices or sheets are applied to the walls of the centrifugal chamber or to the spiral-shaped channels.
11. 11. A gas generator according to claims 1 to 10, characterized in that the immersion tube is helical in shape.
12. 12. The gas generator, particularly for inflating the air pockets serving for the protection of the passengers of a vehicle, with a pressure element, in which a gas generating material is arranged, to an ignition element for turn on the gas generating material, a centrifugal chamber that is formed as a particle separator by centrifugal force and a dip tube placed on the axis of symmetry of the centrifugal chamber that extends towards it, through which the flow of purified gas reaches the air bag through the flow outlet chamber, which is characterized in that the centrifugal chamber, the flow outlet chamber and the immersion tube are placed through a tube and in the tube at least one passage or tangential conduit, it reaches the centrifugal chamber that is connected to the element of pressure.
13. The gas generator according to claim 12, characterized in that the pressure element is integrated into the safety part that is screwed into the tube.
14. 14. The gas generator according to claim 12 or 13, characterized in that the pipe contains 2 gas generators constructed in the mirror image form. The gas generator according to claims 1 to 14, characterized in that the ignition element is integrated in the loading container or in the pressure element.