AIRBAG MODULE

Abstract: A housing (10) is provided for a folded together inflatable airbag and a holder element (12) which can be locked at the housing, with the housing and the holder element bounding a reception region for a gas generator (14) in the locked state. In addition to an airbag and a gas generator, with the housing and the holder element, only two components are required in accordance with the invention, through which the manufacture may be simplified and manufacturing cost reductions may occur. For the assembly of the airbag module, the gas generator (14) is first arranged either at the housing (10) or at the holder element (12) and then the holder element is locked at the housing. The gas generator (14) is then already located in its final position in the airbag module. Through this the subsequent attachment of the folded together airbag in the housing is simplified since more than two parts which are to be connected together need never be brought into the correct relative position.

Description: WO ttO/07855 PCT US99/17736 AIRBAG MODULE TECHNICAL FIELD The invention relates to an airbag module for motor vehicles. BACKGROUND OF THE INVENTION Airbag modules of this kind are known in principle and serve to mount a folded inflatable airbag together with a gas generator which inflates the airbag in the event of an accident as a unit in a motor vehicle e.g. as a driver's, a driver's mate's or a side airbag. The problem (object) lying at the basis of the invention is to provide an airbag module for motor vehicles which is simply constructed and is easy to assemble. SUMMARY OF THE INVENTION This problem is solved through the features of claim 1 and in particular in that a housing for a folded together inflatable airbag and a holder element which can be locked at the housing are provided, with the housing and the holder element bounding a reception region for a gas generator in the locked state. In addition to an airbag and a gas generator, with the housing and the holder element, only two components are required in accordance with the invention, through which the manufacture may be simplified and manufacturing cost reductions may occur. For the assembly of the airbag module in accordance with the invention the gas generator is first arranged either at the housing or at the holder element and then the holder element is locked at the housing. The gas generator is then already located in its final position in the airbag module. Through this the subsequent attachment of the folded together airbag in the housing is simplified since more than two parts which are to be connected together need never be brought into the correct relative position. In accordance with a preferred embodiment of the invention the reception region is formed at least substantially by a depression which is formed at the housing. Through this a particularly easy assembly of the airbag module in accordance with the invention is enabled in that the gas generator is simply laid into the depression and then the holder element is attached. The depression already provides for a secure positioning of the gas generator in the state without the holder element. In accordance with a further preferred exemplary embodiment of the invention the holder element can be latched with the housing, with latching elements which are preferably formed on the holder element cooperating with latching receptions of the housing. Through this a particularly simple possibility of the locking of the holder element at the housing is provided, which enables an even more rapid assembly of the airbag module. In accordance with a further preferred embodiment the holder element has, at its side which points to the reception region in its state of being locked to the housing, at least one damping section which in the state of being locked to the housing is elastically deformable by a gas generator which is arranged in the reception region. Through this the gas generator is pressed against the boundary wall of the reception region so that movements of the gas generator relative to the housing are avoided. This fixing of the gas generator within the reception region simplifies in particular the connection of the gas generator to a control device. Further advantageous embodiments of the invention are set forth in the subordinate claims, in the description and in the drawings. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in the following in an exemplary manner with reference to the drawings. Shown are: Fig. 1 an embodiment of an airbag module in accordance with the invention prior to assembly, and Fig. 2 the airbag module of Fig. 1 in the assembled state, and indeed in a first side view (Fig. 2a), in a second side view (Fig. 2b) and in a plan view (Fig. 2c). DETAILED DESCRIPTION OF THE INVENTION The airbag module in accordance with the invention in accordance with Fig. 1 comprises a housing 10 which is preferably manufactured of plastic in an injection moulding process and which has the shape of a rectangular parallelepiped which is open at one side, in the housing wall 20 of which lying opposite to the open side, which will be designated in the following as the housing base, a depression 11 is formed. The depression 1 1 defines a reception region for a substantially cylindrical gas generator 14, the form of which is matched to the depression 11. The area which is left out by the depression 11 in the housing base 20 has a rectangular outline. The left out area is only slightly narrower, but however significantly shorter than the likewise rectangular housing base 20 and is arranged to be centered so that equally large base surfaces remain in the region of the end surfaces of the housing 10. The side surfaces of the housing 10 are provided with stiffener ribs 28, 30, with one group of stiffener ribs 28 comprising sections of approximately concentric circles and the stiffener ribs 30 of the second group, which are designed as depressions at the housing inner wall which form corrugations, extend parallel to the edges of the housing 10 which bound the side and end surfaces. In the region of the end surfaces of the housing 10 which bound the depression 11 a guide groove 22 for a corresponding positioning flange 24 of the gas generator 14is in each case formed. The guide grooves 22 and the positioning flanges 24 which cooperate therewith serve as positioning means which provide for a correct angular orientation of the gas generator 14 with respect to its longitudinal axis in the depression 11 of the housing 10. In this way it is ensured that a connector 44 for a control device which is provided at least in a front side of the gas generator 14 always has the same orientation with respect to the housing 10, through which the connecting of the gas generator 14 is facilitated in the assembly of the airbag module in accordance with the invention. Latching receptions 34 are formed in the housing base 20 which are provided in the region of the housing base 20 which bounds the depression 1 1 , and which are distributedly arranged around the depression 1 1. The latching receptions 34 are formed in each case as rectangular parallelepipeds which are open on their side remote from the housing base 20 and which project from the housing base 20. A holder element 12 of the airbag module in accordance with the invention which is likewise preferably manufactured of plastic in the injection moulding process has a substantially rectangular base plate 16, the area of which is approximately as large as the area which is left out in the housing base 20 by the depression 11. The holder element 12 is provided with a plurality of latching elements 32 which stand off from a side surface of the base plate 16 and are distributedly arranged corresponding to the latching receptions 34 of the housing 10 along the edge region of the base plate 16. Each latching element 32 comprises a pair of pins which are elastically deformable through pressing together and which stand off at right angles from the base plate 16. Each pin has a locking nose which points away from the respective other pin. Moreover, two circular cut-outs 18 are provided in the base plate 16 of the holder element 12 through which gas which is produced by the gas generator 14 can flow. In addition, the base plate 16 is provided with four cut-outs 38 which in each case have a rectangular outline, with one cut-out — that lying farthest to the right in Fig. 1 — being larger than the other three cutouts in the embodiment in accordance with Fig. 1. At the edge region of each cut-out 38 a strip-like material section which serves as a damping section 36 is connected to the holder element 12. The damping sections 36 have in each case a contact section 40 which extends approximately parallel to the base plate 16 and which is connected to the base plate 16 via two sections which extend at an inclination to the base plate 16 and diverge from one another in the shape of a V in the direction of the base plate 16. The contact sections 40 are at such a distance from the base plate 16 that in the assembled state of the airbag module in accordance with the invention they cooperate with the gas generator 14 which is arranged in the reception region and the damping sections 36 are elastically deformed by the gas generator 14. Through the described forming of the damping sections 36, gas which is produced by the gas generator 14 can not only flow through the circular cut-outs 18 but also through the cut-outs 38. Both the latching elements 32 and the damping sections 36 are preferably designed in a single piece with the base plate 16 of the holder element 12, which is thus in a single piece in this case. The gas generator 14 is provided with gas exit openings 42 which are arranged eccentrically in the longitudinal direction and distributedly in the peripheral direction. The gas generator 14, which is asymmetrically formed in this way, is preferably designed as a two stage gas generator which can be connected at both end surfaces to a control device, with both of the end surfaces of the housing 10 which bound the depression 11 being provided with a cut-out 26 in this case. Fig. 2 shows the airbag module in accordance with the invention of Fig. 1 in the assembled state, with Fig. 2a being a side view of a side wall of the housing 10 which is provided with the stiffener ribs 28, 30. Recognizable are the differently oriented groups of stiffener ribs 28, 30 and the pins of the latching elements 32 of the holder element, which protrude with their free ends out of the latching receptions 34 of the housing 10, which are open at the bottom and which with their latching noses engage behind the lower edge of the latching receptions 34 in a locking manner. Fig. 2b is a side view of an end surface of the housing 10 which is not provided with stiffener ribs and in which in particular a cutout surface 26 which serves for the connection of the gas generator to the control device is recognisable in one of the end surfaces of the housing 10 which bound the depression 11. Fig. 2c is a view into the interior of the housing 10 and onto the holder element 12 which is locked to the housing 10. The base plate 16 of the holder element 12 serves together with the housing base 20 which remains at both sides of the depression as a support surface for a folded together airbag. For the assembly of the airbag module in accordance with the invention the gas generator 14 is first laid into the depression 11 of the housing 10, with the positioning flanges 24 of the gas generator 14 being pushed into the guide grooves 22 of the housing 10. Through the matching of the depression 11 to the cylindrical shape of the gas generator 14 and the corresponding rounding off of the guide grooves 22 and the positioning flanges 24 it is ensured that the gas generator 14 can be arranged in the depression 11 only in its correct position. Then the non-illustrated airbag is attached to the holder element 12 in that the latching elements 32 of the holder element 12 are pushed through holes which are formed in an edge region of the airbag which bounds the open end of the airbag. Then the holder element 12 is pressed with its latching elements 32 into the latching receptions 34 of the housing 10 and locked in this way to the housing 10. The housing 10 and the holder element 12 thus bound a cage-like reception region for the gas generator 14 in which the gas generator 14 is fixed in position through the cooperation with the damping sections 36 which are formed on the holder element 12 and is dampingly seated. At the same time the airbag is mounted in this way at the housing 10. Through the cooperation of the housing 10 and the holder element 12 an additional gas generator housing is thus created inside the housing 10. In the assembled state thus a space having the shape of a rectangular parallelepiped in the described embodiment and which is bounded by the housing walls and the holder element 12 is available for the folded together airbag. The base plate 16 of the holder element 12 serves together with the remaining housing base 20 as a support surface for the folded together airbag. The housing 10 is closed by a non-illustrated covering cap which is secured to the housing 10. In the event of an accident the gas generator 14 is triggered via the non- illustrated control device, with the gas produced flowing out of the reception region for the gas generator 14 through the circular cut-outs 18 and the rectangular cut-outs 38 and into the folded together airbag. As a consequence the base plate 16 of the holder element 12 acts as a kind of nozzle plate which provides for an inflation of the airbag which takes place over a comparatively large area. The larger of the four cutouts 38, which is located furthest to the right in Fig. 1, takes into account the asymmetry of the gas generator 14 and provides for the gas flowing uniformly distributed over the surface of the base plate 16 into the airbag. In accordance with the invention the holder element 12 thus fulfils several functions at the same time in that it fixes the gas generator 14 in its desired position, provides an anchoring for the airbag and serves as a diffusor which provides for the gas produced by the gas generator 14 flowing with a distribution over as large an area as possible and as uniformly as possible into the airbag.

Claims: CLAIMS 1. Airbag module for motor vehicles comprising a housing (10) for a folded together inflatable airbag and a holder element (12) which can be locked at the housing (10), with the housing (10) and the holder element (12) bounding a reception region for a gas generator (14) in the locked state. 2. Airbag module in accordance with claim 1, characterised in that the reception region is formed at least substantially by a depression (11) which is formed at the housing (10). 3. Airbag module in accordance with claim 1 or claim 2, characterised in that the housing (10) has substantially the shape of a rectangular parallelepiped which is open at one side, with a depression (11) preferably being formed in a housing wall (20) which lies opposite to the open side. 4. Airbag module in accordance with at least one of the preceding claims, characterised in that the holder element (12) has a substantially rectangular base plate (16). 5. Airbag module in accordance with at least one of the preceding claims, characterised in that the holder element (12) is designed for the mounting of an airbag. 6. Airbag module in accordance with at least one of the preceding claims, characterised in that the holder element (12) has at least one cut-out (18) for gas which is produced by the gas generator (14) and/or for the mounting of a housing covering. 7. Airbag module in accordance with at least one of the preceding claims, characterised in that a side of the holder element (12) which faces away from the reception region in the locked state is designed as a support surface for a folded together airbag, with the support surface preferably extending parallel to a housing wall (20) which is provided with a depression (11). 8. Airbag module in accordance with at least one of the preceding claims, characterised in that the holder element (12) can be latched with the housing (10), with latching elements (32) which are preferably formed on the holder element (12) cooperating with latching receptions (34) of the housing (10). 9. Airbag module in accordance with at least one of the preceding claims, characterised in that latching receptions (34) are formed in the region of a housing wall (20) which bound a depression (11), and are preferably distributedly arranged around the depression (11). 10. Airbag module in accordance with at least one of the preceding claims, characterised in that latching elements (32) stand off from one side surface of the holder element (12), with the latching elements (32) preferably being arranged in the boundary region of the side surface and preferably distributedly arranged along the boundary region. 11. Airbag module in accordance with at least one of the preceding claims, characterised in that the holder element (12) has at least one damping section (36) at its side which points to the reception region in the state of being locked to the housing (10), which, in the state of being locked to the housing (10), is elastically deformable by a gas generator (14) which is arranged in the reception region. 12. Airbag module in accordance with at least one of the preceding claims, characterised in that the damping section (36) is formed as a strip-like material section which is connected at its ends to the holder element (12). 13. Airbag module in accordance with at least one of the preceding claims, characterised in that the holder element (12) has at least one cut-out (38) with preferably approximately rectangular outline, with a damping section (36) being connected to the holder element (12) at the boundary region which bounds on the cut-out (38). 14. Airbag module in accordance with at least one of the preceding claims, characterised in that a damping section (36) has a contact section (40) which preferably extends approximately parallel to a base plate (16) of the holder element (12) and which in the locked state cooperates with a gas generator (14) which is arranged in the reception region. 15. Airbag module in accordance with at least one of the preceding claims, characterised in that an area which is left out by a depression (11), in an approximately rectangular housing wall (20), has an approximately rectangular outline, with the left out area preferably having approximately the same width as the housing wall (20) and a smaller length than the housing wall (20). 16. Airbag module in accordance with at least one of the preceding claims, characterised in that the reception region is matched to the shape of the preferably substantially cylindrical gas generator (14). 17. Airbag module in accordance with at least one of the preceding claims, characterised in that the housing (10) and/or the holder element (12) are/is provided with positioning means (22, 24) for the gas generator (14), with the housing preferably having guide grooves (22) for positioning flanges (24) which are formed at the gas generator (14), and with the guide grooves (22) preferably being formed in the region of an end surface which bounds the substantially cylindrical depression (11). 18. Airbag module in accordance with at least one of the preceding claims, characterised in that the reception region, preferably a depression (11) which is formed in the housing (10), has at least one cutout (26) via which in the locked state the gas generator (14), which is arranged in the reception region, can be connected to a control device. 19. Airbag module in accordance with at least one of the preceding claims, characterised in that at least one housing wall is provided with stiffener ribs (28, 30), with preferably at least two differently oriented groups of stiffener ribs (28, 30) being provided which in each case extend at least substantially parallel to one another. 20. Airbag module in accordance with at least one of the preceding claims, characterised in that the reception region is designed for the reception of a two-stage gas generator (14). 21. Airbag module in accordance with at least one of the preceding claims, characterised in that the reception region is designed for the reception of a substantially cylindrical gas generator (14) which has gas exit openings (42) which are eccentrically arranged in the longitudinal direction and preferably distributedly arranged in the peripheral direction and which can preferably be connected at least at one end surface to a control device.

Inventors: HANNEMANN JENS, ZIMMERBEUTEL BERND UWE, HANNEMANN, JENS, ZIMMERBEUTEL, BERND, UWE
Applicants: DELPHI TECH INC, DELPHI TECHNOLOGIES, INC.
Application year: 1999
Main classification: B60R21
IPC codes: B60R21