MXPA99000545A - Protection of flame for a bag of - Google Patents

Abstract

The present invention relates to an air bag module comprising: an inflatable gas bag that includes a border defining an inlet opening, an air pump having a pyrotechnic impeller for, when actuated, inflating the air bag gas, a flame protection member having a cylindrical wall of a flexible heat-resistant textile material and a bottom part having a edge defining a central opening corresponding to the gas bag inlet opening, the gas bag and the air pump has a common central axis, the air pump includes a cylindrical wall having outlet openings oriented radially with respect to the central axis, the air pump is surrounded by the opening of the gas bag through the central opening in the lower part of the flame protection member, the cylindrical wall of the flame protection member extends substantially parallel to the axis, the cylindrical wall deflected to a flow of combustion gas from the outlet openings to a flow parallel to the axis when the bag of gas is inflated

Description

FLAME PROTECTION FOR A GAS BAG The invention relates to an air bag module that includes a gas bag with an inlet opening, an air pump with a pyrotechnic propellant, and a flame protection. When igniting pyrotechnic propellants to explosively inflate a gas bag, the gaseous products of the combustion solidify reaching very high temperatures, which can not be tolerated by the material of the air bag made of a synthetic fabric. Therefore, several proposals have been made to determine how the gas pockets of the air bag modules could be configured and placed so that the hot combustion gases can not damage or even destroy them. These means are called "flame protection" and range from sieve-type retention systems that try to prevent the exit of hot solid particles from the air pump, by duplicating the material located in the region at risk to impregnate the gas bag with a heat-resistant material. When duplication of the localized material is proposed, it can not be ensured that the regions of the gas bag first impacted by the hot combustion products are also reliably covered since the protective material can be displaced when it is folded in place if it is not connected to the gas bag material. However, when the material is connected to the gas bag, difficulties are experienced when bending it in place, since the duplication of the connected material is automatically stiffer than the rest of the gas bag material and can in turn result in irregularities when it is folded in place so that the unprotected material can be located in the primary entry region of the hot combustion products. Also, the proposed means for flame protection are often very complicated and expensive. Therefore, the aim of the present is to provide the air bag module of the aforementioned type with an effective flame protection that is simple and affordable, which can be applied to the various methods for bending the gas bag, and so Reliable to prevent hot combustion gases from impacting the gas bag material before they have expanded considerably and therefore, have not had time to cool. To achieve this objective, it is proposed according to the invention that the flame protection consists of a textile part in the form of a crucible of a heat-resistant material, the lower part of which includes a central recess corresponding to the inlet opening of the gas bag and with the edge of the central recess surrounding said entrance opening. In a further development of the invention, a mounting plate is provided, with the edge of a certain inlet opening surrounding the air pump and said edge of the central recess of the textile part in crucible form is held with said air pocket between the mounting plate and air pump. The advantageous characteristics of the mica of the invention can be seen in the dependent claims. Some additional details will be explained based on the example mode as shown in Figs. 1 and 2 in which: Fig. 1 is a schematic illustration of an inflated gas bag according to the invention, and Fig. 2 is a greatly enlarged detail view taken from Fig. 1. Now, with reference to FIG. 1, an inflated gas bag in spherical form 1 including an air pump 2 and a flame protection 3, the gas bag 1 and the flame protection 3 are shown in FIG. the section. According to the invention, the flame protection 3 consists of a textile part in the form of a crucible of a heat-resistant material by means of which the hot combustion gases leaving the air pump 2 substantially vertical to the central line of the module of the air bag are diverted and concentrated in a flow guided parallel to the center line of the gas bag, at least initially. In this way, it is achieved that the hot combustion gases are kept away from the material of the gas bag 1 as long as they have not expanded to at least a certain point and therefore cooled.

Now, referring to FIG. 2, it is illustrated how the gas bag 1 and the lower part 5 of the textile part in the form of a crucible 3 are held laterally between the mounting plate 4 and a surrounding flange 6 of the air pump, by means of which the screws 8 could simultaneously serve to secure the air bag module in a housing or the like. The textile part in the form of crucible 3 is designed and clamped so that its cylindrical wall 9, and when the gas bag is inflated, extends concentrically towards the central line of the air pump radially separated from the outlet openings 7 thereof to ensure that the hot combustion gases emerging can not come into contact with the material of the gas bag 1 until they have expanded to the volume of the textile part in the form of crucible 3. A further improvement could be achieved by means of the edge of the unattached crucible of the textile part in the form of textile 3, which is opposite the floor 5, being duplicated and the duplicated portions connected to each other by means of a seam 10 resulting in the sudden inflation of the gas bag 1, as a result of the above, the hot combustion gases remain trapped in the textile part in the form of crucible 3 until its internal pressure is sufficient to separate the seam. to 10. No additional explanation is required to understand that the expansion response of the gas bag could be influenced by defining to the same extent the separation force of the seam 10.

The flame protection configured in accordance with the invention could simply be attached together with the gas bag. Consequently, no additional means is necessary for the arrangement and the securing thereof within the gas bag. Particularly, there is no need to connect the flame protection with the material of the gas bag, thereby eliminating the difficulties posed when it is bent, as mentioned at the beginning. Therefore, effective and reliable protection of the gas bag material against hot combustion products is provided.

Claims (9)

1. REIVIN DICACIONES
2. 1 . An air bag module that includes a gas bag (1) with an inlet opening, an air pump (2) having a pyrotechnic impeller, and a flame protection (3) characterized in that said flame protection consists of of a textile part in the form of a crucible (3) of a heat-resistant material, the lower part (5) of which comprises a corresponding central recess with an inlet opening of the gas bag (1), with the edge of the central recess surrounding said entry opening. The air bag module as set forth in claim 1, characterized in that a mounting plate (4) is provided, with the edge of said inlet opening surrounding said air pump (2) and is clamped between the air bag (2) and the mounting plate (4) and in which the edge of the central recess of the textile part in the form of a crucible (3) together with the gas bag (1) is held between said mounting plate ( 4) and the air pump (2).
3. 3. The airbag module as set forth in claim 2, characterized in that said air pump (2) comprises an indic cylindrical housing closed at one end, including inlet openings (7) and a surrounding flange (6). ) exiting radially outwards, said flange (6) together with the mounting plate (4) form the holding portion for the gas bag (1) and for the textile part in the form of a crucible (3).
4. 4. The air bag module as set forth in claim 2 or 3 characterized in that said air pump (2) includes a cylindrical wall portion located within said gas bag (1), after assembly and the openings of the air bag (1). outlet (7) for the gaseous products of said impeller, the outlet openings being located in said cylindrical wall portion, the outlet openings will be directed radially towards the central line of the air pump (2).
5. The air bag module as set forth in claim 4, characterized in that said textile part in the form of a crucible (3) of a heat-resistant material comprises an indian cylindrical wall (9) extending more or less parallel to the central line of the air pump (2) and radially separated from said outlet openings (7) when the air bag (1) is activated.
6. The air bag module as set forth in claim 5, characterized in that the axial projection of said cylindrical wall (9) from the clamped edge of the central recess in the lower part towards the open end is 1 to 3 times larger than the diameter of the textile part in the form of a crucible (3).
7. 7. The air bag module as set forth in any of claims 3 to 6, characterized in that connected to the mounting plate (4) are fastening screws (8) that extend, after assembly, to through the holes in said lower part (5) of the textile part in the form of a crucible (3) in the gas bag (1) and in the hole (6) of the air pump (2).
8. 8. The air bag module as set forth in claim 7, characterized in that said fastening screws (8) simultaneously serve to secure said air bag module in a housing (11). The air bag module as set forth in claim 1 to 8, characterized in that the portions of the edge of the crucible on the edge of the textile part in the form of a crucible (3) that are opposite the bottom part. they place one on another and the portions that are placed one on another are connected to each other by means of a seam (10) which separates when said gas bag (1) is inflated.

   SUMMARY

   An air bag module includes a gas bag (1) with an inlet opening, an air pump (2) having a pyrotechnic impeller and a flame protection (3). To provide effective flame protection that is simple and affordable and applies to the various methods of bending the gas bag, the flame protection consists of a textile part in the form of a crucible (3) of a heat-resistant material, whose part The lower part includes a central recess corresponding to the entrance opening of the gas bag (1), and the edge of said central recess surrounds the entrance opening.