Patent Publication Number: US-2023150448-A1

Title: Airbag module, method for exchanging a gas generator of an airbag module, and method for producing an airbag module

Description:
TECHNICAL FIELD 
     The invention relates to an airbag module according to the preamble of claim  1 , a method for replacing an inflator of an airbag module according to the preamble of claim  15  and a method for manufacturing an airbag module according to claim  18 . 
     BACKGROUND 
     In prior art airbag modules, the inflators of the airbag module are usually screwed with the module housing or specific retaining devices or are braced with clip collars. By arranging the inflator in the airbag, for example in a knee airbag, thermal fixation of the folded airbag package is possible, for example, within a limited temperature range only. 
     In addition, replacement of inflators is possible in prior art airbag modules with extreme effort only. In particular, in those airbag modules usually the entire airbag module must be dismantled and then assembled again, wherein frequently also the airbag folding is comprised. Moreover, concepts of airbag modules are known in which the connection between the inflator and the module housing cannot be dismantled in a nondestructive manner. 
     SUMMARY 
     It is the object of the invention to provide an airbag module that enables to easily remove and to easily replace the inflator without completely dismantling the airbag module. 
     It is a further object of the invention to provide a method for replacing an inflator of an airbag module of this type. 
     It is another object of the invention to provide an improved method for manufacturing an airbag module comprising a thermoset airbag package. 
     Achieving the Object 
     The features according to claim  1  and the claims  15  and  18  result in achieving the object. Advantageous configurations are described in the subclaims. 
     An airbag module according to the invention comprises at least a module housing, an airbag and an inflator as well as a holding element that includes a seat for the inflator and at least partly encloses the inflator. The module housing may be made from metal or plastic. In addition, the module housing can be made at least partly from fabric or felt and can be configured as a fabric module housing. Further, in the present case also a module holder constituting an element of a fabric module housing, for example, is comprised by the term “module housing”. Such a module holder can be made from metal or plastic, for example. 
     The holding element is particularly configured such that it encloses the inflator at least partly in a cage-like manner. Enclosing in a cage-like manner in this case is intended to describe that the holding element partly encloses the inflator in the installed state preferably at least in directions that are perpendicular to the longitudinal direction of the inflator. The holding element is preferably configured and disposed in or at the module housing in such a way that an inflator is allowed to be inserted/slid in from one side of the airbag module. 
     The holding element for the inflator further includes one securing element, preferably plural securing elements which are intended at least for securing the holding element and the inflator to the module housing. The holding element and/or the module housing further comprise(s) at least one fixing element for fixing the inflator in the holding element. Fixation of the inflator in the holding element can be carried out in particular by force and/or form closure. 
     The airbag module may be configured particularly as a knee airbag module and the airbag may be configured particularly as a knee airbag. The inflator of an airbag module according to the invention is preferably configured as a tubular inflator. Alternatively, the airbag module therefore can also be a side airbag module, a center airbag module, a curtain airbag module or a passenger airbag module. In addition, the airbag module can also be in the form of a rear occupant airbag module that can be disposed particularly in a front seat, or an overhead airbag module that is disposed in the roof area of the vehicle. 
     The module housing can be made, for example, from metal and/or plastic and/or can be at least partially a fabric housing. The securing elements can be in the form of securing bolts and securing nuts and/or of securing clips, for example, so that the holding element and the airbag can be secured to the module housing via the securing elements. 
     The holding element may consist of diverse materials such as steel, aluminum, magnesium, metal alloys and/or plastic and, accordingly, can be manufactured as a tube, a stamped and bent part, casting, deep-drawn part and/or injection molded part, for example. 
     In a preferred embodiment, the holding element comprises a positioning element and the inflator comprises a positioning element seat. As an alternative, the inflator can comprise the positioning element and the holding element can comprise the positioning element seat. The positioning element and the positioning element seat are designed to correspond to each other such that the inflator can be disposed at a predetermined position in the holding element. 
     The holding element may be provided to comprise plural positioning elements. This allows to receive inflators of different overall size in the holding element, for example. In this way, on the one hand, the same holding element can be used for different designed airbag modules. In addition, for example in developing or adapting the airbag module for a specific vehicle, a more powerful or a weaker inflator can be easily integrated in the airbag module, if this becomes necessary by changed or adjusted requirements. 
     In particular, by the predetermined position of the inflator in the holding element, a predetermined plug positioning of the plug member disposed on the inflator can be provided when the airbag module is installed in a vehicle. The inflator of the airbag module can be connected via the plug member, such as via an ignition cable, to a control unit of the vehicle, specifically to an airbag control device of the vehicle. Further, the positioning element and the positioning element seat serve, by positioning the inflator at a predetermined position in the holding element, as an anti-rotation protection that prevents the inflator from rotating in the holding element. 
     In order to retain the inflator at the predetermined position and to prevent the connection formed by the positioning element and the positioning element seat from being inadvertently released, the holding element can further comprise a positioning fixation device. The positioning fixation device can be, for example, a spring element or a pin element that prevents the inflator particularly from axially moving (along the longitudinal inflator axis) by maintaining the inflator at the predetermined position. Alternatively, the positioning element and/or the positioning fixation device can be generally configured so that it is/they are suited to fix the inflator at a predetermined position. For example, the positioning element and/or the positioning fixation device can also be in the form of a rivet or a screw element. 
     The positioning element(s) can be introduced into the holding element as a resilient dot embossing. Such a resilient dot embossing can be created, for example, in such a way that, when the holding element is manufactured in the punching and bending process, in a portion enclosing the dot embossing the material of the holding element is removed except for at least one spring arm. Preferably, the dot embossing in such embodiment remains connected to the holding element via at least two spring arms. In the finished state, the dot embossing is directed into the interior of the holding element and corresponds to a positioning element seat of the inflator which may be in the form of a funnel-shaped imprint in the inflator, for example. Alternatively, instead of the dot embossing, also a differently shaped protrusion being directed into the interior of the holding element can constitute the positioning element, such as a weld bead arranged in the area of the spring arm. 
     In another embodiment, the positioning element and the positioning element seat can be in the form of a bayonet lock, the positioning element being preferably configured as a bulge and the positioning element seat being preferably configured as an indentation. 
     The positioning element preferably is configured, in such embodiment, as an elevation directed into the interior of the holding element. For example, the positioning element can be in the form of a dot embossing in the holding element which is preferably introduced in a portion of the holding element enclosing the discharge area of the inflator. 
     The positioning element seat in this embodiment is preferably a groove disposed in the inflator. The groove of the positioning element seat is preferably introduced into the discharge area of the inflator. In order to obtain sufficient anti-rotation protection, the groove has a first leg and a second leg which are preferably aligned with each other in V-shape, the leg tail of the first leg and the leg head of the second leg forming the tip of the V-shape. The groove of the first leg is formed at the leg head in a preferably widened form and tapers toward the tip of the V-shape so that the finding and insertion of the positioning element configured as a bulge is facilitated. The leg tail of the second leg helps determine, in such embodiment, the latching position in which the inflator is in the predetermined position. 
     In order to maintain the inflator in the predetermined position and to prevent the bayonet lock formed by the positioning element and the positioning element seat from being inadvertently released, the holding element can further comprise a positioning fixation device. The positioning fixation device can be, for example, a spring element or a pin element that prevents the inflator from axially moving (along the longitudinal inflator axis) by maintaining the inflator relative to the holding element at the latching position and, thus, at the predetermined position. 
     In an alternative embodiment, the positioning element is configured as a wedge-shaped bulge, in particular as a wedge-shaped notch, and the positioning element seat is configured as an indentation corresponding to the wedge-shaped bulge, in particular as a wedge-shaped groove. 
     The positioning element in the form of a wedge-shaped notch in such embodiment is preferably formed in the holding element and preferably extends along the longitudinal axis in a portion of the holding element which encloses the discharge area of the inflator. The wedge-shaped notch is preferably in the form of a bulge facing the interior of the holding element. The groove formed corresponding to the wedge-shaped notch preferably is introduced as a wedge-shaped longitudinal groove into the inflator, particularly into the discharge area of the inflator. By configuring the positioning element as wedge-shaped longitudinal notch and the positioning element seat as corresponding wedge-shaped groove, a twist-proof positioning of the inflator can be obtained in the holding element. In addition, the holding element can comprise, also in this embodiment, a positioning fixation device that prevents the inflator from being displaced in the axial direction in the holding element. The positioning fixation device can be in the form of a spring element disposed at the end of the holding element which encloses the plug member of the inflator so that the spring element helps the inflator press toward the portion of the holding element enclosing the discharge area. As an alternative, the positioning fixation device can be in the form of a screw or plug-in element that is adapted to be screwed or attached to the end of the holding element enclosing the plug member of the inflator and, thus, presses the inflator toward the portion of the holding element enclosing the discharge area. 
     In a preferred embodiment, the fixing element for fixing the inflator in the holding element is configured as a recess directed into a housing interior of the module housing. For example, the recess is configured as a bead introduced to the module housing. 
     The recess directed into the module housing is located in the module housing in an area where the holding element is disposed with the inflator. The fixing element in the form of a recess is configured such that, when the securing elements by which the holding element and the airbag are secured to the module housing are fastened, it engages in a dedicated opening of the holding element and forces the inflator against an inner wall of the holding element and, thus, fixes the inflator in the holding element. The recess formed as a recess in the module housing effectuates simple fixation of the inflator in the holding element which moreover prevents noise caused by vibrations of the inflator in the holding element in a simple manner. 
     In an alternative embodiment, the fixing element for fixing the inflator is disposed in or on the module housing such that, when the holding element is fastened, the fixing element engages in an inflator neck portion of the inflator, thereby positively fastening the inflator in the holding element. For example, the fixing element can be configured, in such embodiment, as a, particularly bent, pin element which is disposed in the housing interior of the module housing. 
     In another alternative embodiment, the fixing element can be formed integrally with a positioning fixation device, in particular as a spring element. For this purpose, the spring element can have a latching area, for example, that is adapted to engage in an inflator neck portion to thereby prevent or restrict an axial movement. Preferably, the module housing in such embodiment also comprises a fixing element. 
     Such a positioning fixation device can help fix the inflator in the holding element, particularly already before the holding element with the inflator is secured to the airbag module housing and/or to the vehicle structure, thereby allowing to further facilitate the installation of an airbag module according to the invention. 
     In another alternative embodiment, the fixing element comprises, for fixing the inflator in the holding element, also a spring element that is preferably operatively connected to a bracing device. 
     In such embodiment, the spring element may be wave-shaped, the bracing device being preferably operatively connected to a wave crest of the wave-shaped spring element. The bracing device has, for example, a bolt or any other screw member that can be utilized to brace the spring element against the inflator to thereby non-positively fix the inflator in the holding element. In one embodiment, the bracing device can be provided to be released via an opening provided in the module housing without releasing the securing elements of the holding element so as to release the non-positive connection between the inflator and the holding element and to remove the inflator. 
     Alternatively, such a fixing element configured as spring element can be provided to be disposed in the holding element in such a way that, by fastening the securing elements and, thus, securing the holding element and the airbag to the module housing, the inflator is fixed non-positively by the spring element in the holding element. 
     In another alternative embodiment, the fixing element is configured as a latching seat disposed in the holding element. The latching seat is formed to receive a latching element disposed on the inflator. The latching element formed on the inflator is, for example, a spring system the spring elements of which are configured so that they can engage in the latching seats to thereby allow the inflator to be latched in a fixed position inside the holding element. 
     In another embodiment, the holding element can comprise a female thread specifically constituting the fixing element that corresponds to a male thread disposed on the inflator. 
     In such embodiment, the holding element can be, for example, in the form of a cage-like tube having a portion that includes a female thread, or in the form of an airbag nut that is sewn into the airbag of the airbag module particularly in the area of the inflation mouth. The male thread can be introduced or integrated, for example, directly in an outer cover of the inflator or can be formed on an inflator nut which is secured specifically adhesively to the inflator. 
     In a further embodiment, the fixing element comprises a fixing bolt which is preferably disposed in a fixing bolt seat on the holding element and/or the module housing. For fixing the inflator in the holding element, the fixing bolt can engage in a fixing bolt seat disposed on and/or in the inflator. 
     Further, the holding element may comprise a diffusor for the inflator which, when the inflator is activated, serves for directing the gas flow leaving the discharge area of the inflator and, moreover, can prevent the gas flow from directly flowing toward the fabric of the airbag in the discharge area. The diffusor of the holding element has an outer wall which encloses the inflator in the discharge area at least partially in the circumferential direction. The outer wall of the diffusor of the holding element has an interruption edge extending substantially in the longitudinal direction and, when the inflator is activated, is bent open along said interruption edge. The discharge direction for the gas flowing out of the inflator is defined by the bent-open outer wall of the diffusor. In addition, the bent-open outer wall of the diffusor is capable of protecting the fabric of the airbag. 
     Alternatively, the diffusor can be configured in the holding element as a diffusor opening. Accordingly, the discharge direction of the gas flowing out of the inflator is substantially defined by the diffusor opening. 
     The holding element can further comprise anti-bending devices in the area of the diffusor. The anti-bending devices can be designed, for example, so that latching lugs are bent by about 90° and engage in corresponding slits in the holding element. The anti-bending devices can particularly prevent the holding element in the form of a punched and bent part from being inadvertently bent open in the area of the diffusor when the airbag module is activated. In this way, the gas of the inflator can be achieved to flow off substantially through the diffusor opening. 
     In order to facilitate removal of the inflator from the holding element of the airbag module, the inflator can additionally comprise a removing aid which is preferably disposed in the area of the plug member of the inflator. 
     The object of the invention is further achieved by a method for replacing an inflator of an airbag module, the airbag module being particularly an afore-described airbag module according to the invention. The method comprises at least the following steps. 
     Initially, the securing elements are released so that the securing of the holding element and the airbag is released or at least loosened from the module housing so that the direct and/or indirect fixation of the inflator via the securing elements in the holding element is released. Direct fixation in this context describes that the securing element and the fixing element are in direct operational connection. Indirect fixation describes, on the other hand, that the securing element and the fixing element are indirectly operatively connected. 
     As an alternative, it can be provided that for releasing the fixation of the inflator in the holding element additionally or only the fixing element must be released so as to release the fixation of the inflator in the holding element. 
     The question whether only the securing elements or the fixing element or both the securing elements and the fixing element must be released is dependent on the embodiment of the airbag module. 
     In the further method steps, at first the old inflator is removed from the holding element in the module housing, before a new inflator is inserted into the holding element. Removing the old inflator and inserting the new inflator can be carried out, for example, with the aid of pliers corresponding to the removing aid of the inflator. 
     When the new inflator has been inserted into the holding element, the securing elements are fastened so as to fasten and secure the holding element and the inflator on the module housing again and to fix the inflator directly and/or indirectly in the holding element by fastening the securing elements. 
     Alternatively, for fixing the inflator in the holding element, additionally or only the fixing element can be provided to be fastened/fixed to effectuate the fixation of the inflator in the holding element. 
     The question whether only the securing elements or the fixing element or both the securing elements and the fixing element must be fastened/fixed is dependent on the embodiment of the airbag module. 
     In one embodiment of the method, the inflator is braced and thus fixed in the holding element, when fastening the securing elements, by a fixing element disposed on the module housing and/or integrated in the module housing. This may be the case, for example, if the fixing element is formed as a recess facing the housing interior in the module housing. This is an indirect fixation in which the securing element and the fixing element are indirectly operatively connected. 
     In an alternative embodiment of the method, the inflator is fixed in the holding element by a fixing element disposed on/in the holding element or corresponding to the holding element, wherein the fixation can be carried out in a separate method step or by interaction when fastening the securing elements. 
     The object of the invention is further achieved by a method for manufacturing an airbag module, the airbag module comprising at least a module housing, an airbag, an inflator and a holding element for the inflator. The airbag module is specifically an afore-described airbag module according to the invention. In particular, the airbag module may be a knee airbag module, a side airbag module or a center airbag module. 
     The method comprises at least the following steps. 
     At first the holding element is inserted into the unfolded airbag and subsequently the airbag is folded so that an airbag package is created. As an alternative to this, at first the holding element can be inserted into the folded airbag to create the airbag package. Further, the holding element can be provided to be inserted into a partly folded airbag and subsequently the airbag can be provided to be completely folded to create the airbag package. 
     In the next method step, the afore-created airbag package is thermoset. 
     During thermosetting, the airbag package is heated, specifically to a temperature of more than 90° C. The temperature to which the airbag package is heated is in particular higher than a maximum admissible thermosetting temperature of the inflator of the airbag module. The maximum admissible thermosetting temperature of the inflator usually depends on a safety ignition temperature at which the inflator must trip in a controlled manner. 
     Subsequently, the heated airbag package is compressed and cools down under the pressure. By the heating of the airbag after folding and the subsequent cooling of the folded airbag under pressure, the folding of the airbag is maintained without fixation being required. 
     When the thermoset airbag package is cooled, it can be inserted into the module housing of the airbag module. As a matter of course, the airbag package need not be inserted into the module housing immediately after cooling, but for the time being the thermoset airbag package can also be intermediately stored. 
     Finally, the inflator, which in a typical embodiment is a tubular inflator, is inserted into the holding element and is fastened in the holding element. Insertion and fastening of the inflator can be carried out both during manufacture of the airbag module and as late as directly during installation of the airbag module in the vehicle. Due to the insertion and the fastening of the inflator not before the airbag module is installed in the vehicle, the inflator and the airbag module which does not yet comprise an inflator can be dispatched separately from each other to the car manufacturer. 
    
    
     
       BRIEF DESCRIPTION OF FIGURES 
       Further advantages, features and details of the invention will be evident from the following description of an embodiment not to be understood in a restricting manner as well as based on the drawings, wherein: 
         FIG.  1    a) shows a schematic sectional view across a first embodiment of an airbag module according to the invention and b) shows a perspective detail view of a plug element of the inflator of the airbag module, 
         FIGS.  2    a) and b) show perspective views of a first embodiment of a holding element of an airbag module according to the invention, 
         FIG.  3    shows a perspective side view of the holding element according to  FIG.  2   , 
         FIGS.  4    a) and b) show perspective views of a second embodiment of a holding element of an airbag module according to the invention, 
         FIG.  5    shows a perspective side view of the holding element according to  FIG.  4   , 
         FIGS.  6    a) and b) show perspective views of a third embodiment of a holding element of an airbag module according to the invention, 
         FIG.  7    shows a perspective view of a fourth embodiment of a holding element of an airbag module according to the invention, 
         FIG.  8    shows a bottom view of the holding element according to  FIG.  7   , 
         FIG.  9    shows a perspective view of a discharge area of an embodiment of an inflator configured corresponding to a holding element according to  FIG.  7   , 
         FIG.  10    shows a perspective view of a diffusor of the holding element according to  FIG.  7    which comprises a first embodiment of an addition position fixation device, 
         FIG.  11    shows a perspective view of a diffusor of the holding element according to  FIG.  7    which comprises a second embodiment of an additional position fixation device, 
         FIG.  12    shows a perspective view of a discharge area of an embodiment of an inflator configured corresponding to a holding element according to  FIG.  13   , 
         FIG.  13    shows a perspective view of a fifth embodiment of a holding element of an airbag module according to the invention, 
         FIG.  14    is a top view onto the holding element according to  FIG.  13   , 
         FIG.  15    shows a partial view of an airbag module according to the invention in the area of a plug element of the inflator with a) a fastened holding element and b) a released holding element, 
         FIG.  16    shows a partial view of an airbag module according to the invention with a sixth embodiment of a holding element and an inserted inflator, 
         FIG.  17    shows a partial view of the airbag module and the inflator according to  FIG.  16    without the holding element, 
         FIG.  18    shows a partial view of an axial end of the holding element according to  FIG.  16   , 
         FIGS.  19    a) and b) show perspective views of a seventh embodiment of a holding element and of an inflator of an airbag module according to the invention, 
         FIGS.  20    a) to c) show different detail views of axial ends of the holding element according to  FIG.  19   , 
         FIG.  21    shows a schematic sectional view across an inflator and an eighth embodiment of a holding element, 
         FIG.  22    a) shows a schematic sectional view across a nineth embodiment of a holding element and b) shows an embodiment of an inflator corresponding to the holding element, 
         FIG.  23    shows a schematic sectional view across an inflator and a tenth embodiment of a holding element, 
         FIGS.  24    a) and b) show a schematic sectional view across an inflator and an eleventh embodiment of a holding element, and 
         FIG.  25    a) shows a schematic sectional view across an inflator and a twelfth embodiment of a holding element and b) shows a view of an axial end of the inflator and the holding element. 
     
    
    
     DESCRIPTION 
       FIG.  1    illustrates a sectional view across an embodiment of an airbag module  10  according to the invention. The airbag module  10  comprises at least a module housing  12 , a holding element  14 , an inflator  16  and an airbag the representation of which was renounced for reasons of clarity. 
     The holding element  14  comprises a seat  18  for the inflator  16  which encloses the inflator  16  at least partly in a cage-like manner. Further, the holding element  16  comprises securing elements  20 , in this case securing bolts  21  and securing nuts  22  via which at least the holding element  14  and the airbag can be secured to the module housing  12 . Via the securing elements  20  to  22 , furthermore the airbag module  10  can be arranged in a vehicle, for example as a knee airbag module in a lower area of the dashboard. 
     In the shown embodiment, the holding element  14  comprises a positioning element  26  and the inflator  16  comprises a positioning element seat  28  by which the inflator  16  can be positioned at a predetermined position in the holding element  14 . 
     The positioning element  26  is disposed on the holding element in the area of the diffusor  32 . The positioning element seat  28  is disposed in the inflator  16  in the discharge area  36 . The inflator  16  comprises, on the end opposite to the discharge area  36  in the longitudinal direction L, a plug element  38  via which the inflator  16  of the airbag module  10  can be connected, e.g., via a control and/or ignition line, to a control unit of the vehicle, specifically an airbag control device of the vehicle. In the area of the plug element  38 , the inflator  16  in the shown embodiment has a removing aid  74  on which the inflator  16  can be gripped via pliers, for example, particularly when it is removed from the holding element  14  or when it is inserted into the holding element  14 . 
     The module housing  12  comprises a fixing element  24  by which the inflator can be fixed in the holding element  14 . The fixing element  14  in the form of a recess  30 , in this case a bead  30 , engages in an opening  40  of the holding element  14 , when the holding element  14  is fastened to the module housing  12  via the securing elements  20  to  22 , and forces the inflator  16  against an inner wall  42  of the holding element  14 . In this way, the inflator  16  is fixed in the holding element  14 . In addition, via said non-positive fixation, noise caused by vibrations of the inflator  16  in the holding element  14  can be easily prevented. 
     In the airbag module  10  according to the invention of  FIG.  1   , for replacing the inflator  16  it is not necessary to dismantle the whole airbag module  10 . In order to replace the inflator  16 , at first only the securing elements  20  to  22  are loosened so far that the inflator  16  is no longer forced against the inner wall  42  of the holding element by the bead  30  of the module housing  12 . Subsequently, the inflator  16  to be replaced can be removed from the holding element  14  via the removing aids  74  and a new inflator  16  can be inserted. Then, the securing elements  20  to  22  are fastened again, causing the bead  30  of the module housing to force the new inflator  16  against the inner wall  42  of the holding element  14  and to thus fix the inflator  16  in the holding element  14 . 
     It is another advantage of the airbag module  10  according to the invention as illustrated in  FIG.  1    that the holding element  14  acts as a placeholder for the inflator  16 , when the airbag module is manufactured, and in this way the inflator  16  can be inserted, for example, as late as at the end of the manufacturing process. This allows in particular that the airbag package consisting of the folded airbag and the holding element  14  can be fixed in a thermosetting process by heating and subsequent cooling under pressure, without a maximum admissible thermosetting temperature of the inflator  16  having to be considered. 
       FIGS.  2  and  3    illustrate a first embodiment of the holding element  14  that is manufactured as a punched and bent part and has a substantially square cross-section with rounded corner regions. The holding element  14  comprises securing elements  20  configured as securing bolts  21  which are press-fitted into the holding element  14 , for example. In order to be able to press-fit the securing elements  20  into the holding element  14  after the punching and bending process, the holding element  14  includes installation openings  114 . Alternatively, the securing elements  20  can be secured to the holding element  14  also by other manufacturing methods, such as by welding, as a matter of course. 
     The holding element  14  further has an opening  40  in which a fixing element  24 ,  30  of the module housing  12  (see  FIG.  1   ) can engage, for example. Moreover, the weight of the holding element  14  can be reduced by the opening  40 . The holding element  14  further comprises a diffusor  32  for the inflator  16  which is formed in the holding element of  FIGS.  2  and  3    as diffusor opening  80 . 
     The holding element  14  comprises two positioning elements  26  in the area of the diffusor  32 . The positioning elements  26  are configured in this case as resilient dot embossings  61  facing the interior of the holding element. This allows to insert two different configurations of an inflator  16 , in particular two inflators of different performance levels, into the holding element. The resilient dot embossing  61  can be produced in the punching and bending process by the fact that the material of the holding element is removed or, resp., punched out in the region around the dot embossing except the two spring arms  124 . As an alternative to the dot embossing  61  facing the interior of the holding element, a protrusion of any design facing the interior of the holding element can be disposed on/in the holding element  14 , such as in the form of a material thickening in the region of the spring arms  124 , for example a weld bead disposed in the region of the spring arms (not shown). 
     The holding element  14  comprises, at the end opposite to the diffusor  32 , a first embodiment of additional positioning fixation devices  62  which are in the form of resilient clip elements. The positioning fixation devices  62  are provided especially for fixing the inflator  16  in the holding element  14 , before the holding element  14  and the inflator  16  are secured in the module housing or to the vehicle structure via the securing elements  20 . To this end, the positioning fixation devices  62  shown here are formed integrally with fixing elements  24  as a spring element  120 . 
     In the shown embodiment, the inflator  16  is pre-fixed in the holding element  14 , after being inserted into the seat  18  of the holding element  14 , at least by the positioning fixation device  62  opposite to the securing elements  20 . By the positioning fixation device  62  disposed on the holding element  14  on the side of the securing elements  20 , the pre-fixation can be additionally intensified. Moreover, the inflator  16  can be forced, when the holding element  14  and the inflator  16  are fastened to the module housing  12 , against the side of the holding element  14  opposite to the securing elements  20  by the positioning fixation device  62  disposed on the holding element  14  on the side of the securing elements  20  and thus can be additionally fixed at least non-positively in the holding element  14  within the airbag module  10 . 
     The positioning fixation device  62  disposed on the holding element  14  on the side of the securing elements  20  can be formed integrally with the holding element  14  or can be disposed on the holding element as a separate component in the manufacturing process. 
     The securing element  62  disposed on the side of the holding element  14  opposite to the securing elements  20  moreover acts as an additional fixing element  24  to fix the inflator  16  in the holding element  14 , when the holding element  14  and the inflator  16  are fastened in the module housing  12  via the securing elements  20 . 
     The holding element  14  further comprises anti-bending devices  112  in the area of the diffusor  32 . The anti-bending devices  112  are designed such that latching lugs are bent by 90° and engage in corresponding slits. They can prevent the holding element  14  formed as a punched and bent part from inadvertently bending open when the airbag module  10  is activated so that the gas of the inflator  16  substantially flows off through the diffusor opening  80 . 
       FIGS.  4  and  5    show a second embodiment of the holding element  14 . As the second embodiment is largely similar to the above-described first embodiment and the elements exhibit the same characteristics, hereinafter substantially the differences of the embodiments will be illustrated. For the parts known from the first embodiment the same reference symbols are used. In this respect, the foregoing explanations are referred to. 
     The holding element  14  is equally manufactured as a punched and bent part and has a substantially circular cross-section, the cross-section having a bulge in the area in which the securing elements  20  are disposed. 
     Further, the diffusor opening  80  of the diffusor is configured to be larger compared to the holding element  14  of the  FIGS.  2  and  3   .  FIG.  6    illustrates a third embodiment of the holding element  14  in which for already known elements again the same reference symbols are used and the foregoing explanations are referred to. 
     The holding element  14  of  FIG.  6    is likewise configured as a punched and bent part but, in contrast to the foregoing embodiments, has no installation openings for the securing elements  20  configured as securing bolts  21 , as they were arranged on the holding element  14  already before the punching and bending process, such as by press-fitting or by welding. 
     The holding element  14  has a substantially square cross-section. In contrast to the holding element  14  according to the first embodiment, the positioning elements  26  are disposed on the sidewall opposite to the diffusor opening in the holding element  14  rather than in one of the sidewalls adjacent to the diffusor opening  80 . In addition, the holding element  14  has, apart from the opening  40  in which a fixing element  24  of the module housing  12  can engage, further openings  41  which substantially serve for optimizing the weight of the holding element  14 . The openings  41  in the area of the diffusor  32  can further allow for an additional lateral gas outlet, when the airbag module  10  and, thus, the inflator is activated. 
       FIGS.  7  and  8    show a fourth embodiment of the holding element  14  which is manufactured as a tube. The holding element  14  comprises securing elements  20  in the form of securing bolts  21  which are welded to the holding element  14  or are press-fitted in the holding element  14 , for example. Further, openings  40  are shown by which the weight of the holding element  14  is reduced and in which a fixing element  24 ,  30  of the module housing  12  (see  FIG.  1   ) can engage. 
     The holding element  14  comprises a diffusor  32  for the inflator  16  including an outer wall  34  which encloses the inflator  16  at least partially in a discharge area  36  of the inflator  16  in the circumferential direction (see  FIG.  10   ). The outer wall  34  of the diffusor  32  has an interruption edge  44  extending substantially in the longitudinal direction L. When the inflator  16  is activated, the outer wall  34  is bent open along said interruption edge  44 , allowing an outflow direction for the gas and, resp., the gas flow to be defined. In order to enable such bending open and to restrict the expansion of the diffusor along the longitudinal direction L, an interruption  46  is introduced to the holding element  14 , which interruption  46  may be a predetermined breaking point in further embodiments (not shown). 
     In the area of the diffusor  32  of the holding element  14 , the positioning element  26  is introduced as a bulge facing the interior of the holding element, in this case as a dot embossing  60 . 
       FIG.  9    shows the discharge area of an inflator  16  corresponding to the holding element  14  of  FIGS.  2  to  8   . The discharge area  36  has a plurality of discharge openings  37  through which the gas of the inflator  16  can flow out when the latter has been activated. 
     In the discharge area  36 , a positioning element seat  28  is disposed which is configured together with the positioning element  26  in the manner of a bayonet lock. The positioning element seat  28  is in the form of a groove  48  having a first leg  50  and a second leg  52  which are aligned with each other in V-shape, the leg tail of the first leg  50  and the leg head of the second leg  52  forming the tip  56  of the V-shape. The groove  48  is widened at the first leg  50  in the area of the leg head  54  and tapers toward the tip  56  of the V-shape so that the finding and insertion of the positioning element  26  in the form of a bulge is facilitated. In the shown embodiment, the latching position in which the inflator  16  is in the predetermined position in the holding element  14  is determined by the leg tail  58  of the second leg  52 . 
     In particular in a holding element  14  according to the first three embodiments ( FIGS.  2  to  6   ), the positioning element seat  28  can also be configured as an indentation in the form of the resilient dot embossing  61 , in particular as a circular or oval indentation (not shown). 
       FIG.  10    shows a detail view of the diffusor  32  of the holding element  14  comprising a second embodiment of an additional position fixation device  62 . The position fixation device  62  serves for generating an axial force upon the inflator to intensify the functionality of the bayonet lock formed of the positioning element  26  and the positioning element seat  28 . For this purpose, the position fixation device  62  comprises a spring region  64  by which the inflator  16  is forced into the latching position of the bayonet lock. The position fixation device  62  shown here further comprises a buffer element  66  via which it can be controlled, for example, how far the outer walls  34  of the diffusor  32  of the holding element  14  can bend open, when the inflator  16  has been activated. 
       FIG.  11    also shows a detail view of the diffusor  32  of the holding element  14 , wherein a third embodiment of an additional position fixation device  62  is illustrated in  FIG.  11   . In the embodiment shown in  FIG.  11   , the position fixation device  62  is disposed on the diffusor  32  in alignment with the positioning element  26  and the securing elements  40 . The position fixation device  62  can be arranged, for example, via an adhesive connection. The position fixation device  62  protrudes into the interior of the holding element toward the interruption edge  44 , the portion of the position fixation device  62  protruding into the interior of the holding element being in the form of a spring region  64 . 
       FIG.  12    illustrates the discharge area  36  of an inflator  16  with another alternative embodiment of the positioning element seat  28 . In  FIGS.  13  and  14   , a fifth embodiment of the holding element  14  is shown which has a positioning element  26  corresponding to the positioning element seat  28  of the inflator  16 . The fifth embodiment is similar to the afore-described fourth embodiment. For the parts known from the preceding embodiments the same reference symbols are used. In this respect, the foregoing explanations are referred to. 
     The positioning element  26  of the holding element  14  is a wedge-shaped longitudinal notch  70  and the positioning element seat  28  of the inflator  16  is a wedge-shaped groove  68  corresponding to the wedge-shaped longitudinal notch  70 . In the embodiment of  FIGS.  13  and  14   , the holding element  14  is manufactured as a punched and bent part. The securing bolts  21  can equally be welded to the holding element or can be inserted in dedicated securing element seats not shown here. The holding element  14  may further comprise fixing elements  24  in the form of outer wall segments  72 . The outer wall segments can be forced, when the holding element  14  is fastened in the module housing  12  via a fixing element  24  of the module housing  12 , for example (see  FIG.  1   ), against the inflator  16  and can thereby (additionally) fix the latter in the holding element  14 . 
       FIG.  15    illustrates a partial view of an airbag module  10  according to the invention with a holding element  14  secured/fastened in  FIG.  15    a) and with a holding element  14  released in  FIG.  15    b). 
     The module housing  12  has an (additional) fixing element  24  in the area of the plug element  38  of the inflator  16 . In the fastened state of the holding element  14 , the additional fixing element  24  moreover acts as a position fixation device  62  which prevents an axial movement of the inflator  16 . In addition, in this embodiment removal of the inflator  16  in the fastened position is prevented by the fixing element  24 . In order to be able to remove the inflator from the holding element  14 , at first the securing elements  20  must be released so that the holding element  14  and the inflator  16  are in the removing position shown in  FIG.  15    b). 
       FIG.  16    illustrates another embodiment of a module housing  12  in the form of a module holder  12  for a fabric module housing as well as a sixth embodiment of a holding element  14  with an inserted inflator  16  of an airbag module  10  according to the invention. 
     The holding element  14  according to the sixth embodiment comprises a fixing element  24  that is formed integrally with a positioning fixation device  62  as a spring element  120 . The spring element  120  comprises a latching area  122  which is suited for engaging in an inflator neck portion  116  of the inflator  16  (see  FIG.  18   ). 
     The module housing  12  also includes a fixing element  24  which in this case is a bent pin element  118  (see also  FIG.  17   ). When fastening the holding element  14  with the inflator  16  to the module housing  12 , the pin element  118  engages in the inflator neck portion  116  of the inflator  16 , thereby fixing the inflator  16  at least positively in the holding element. 
       FIGS.  19    a) and b) schematically illustrate the insertion of the inflator  16  into a seventh embodiment of the holding element  14 . In the area of the diffusor  32 , the holding element  14  comprises an embodiment of a position fixation device  62  which is in the form of a pin-shaped stop, see  FIGS.  20    a) and b). 
     The holding element  14  moreover comprises a positioning element  26  which, in connection with the corresponding positioning element seat  28  of the inflator  16 , maintains the inflator  16  at a predetermined position in the holding element  14  and prevents rotation, for example. 
     Moreover, the holding element  14  comprises a fixing element  24  which, in the fastened state of the holding element  14 , prevents an axial movement of the inflator  16 . Furthermore, the fixing element  24  of the holding element  14  prevents the inflator  16  from being removed in the fastened state. In order to be able to remove the inflator  16  from the holding element  14 , at first the fastening elements  20  must be released. 
     In the further embodiments shown below, for the parts known from the previously shown embodiment, the same reference symbols are used and merely the differences are discussed in detail. In this respect, the foregoing explanations are referred to. 
       FIG.  21    illustrates an eighth embodiment of the holding element  14  which is manufactured as a tube. The holding element  14  has a diffusor opening  80  in the discharge area  36  of the inflator  16 . The fixing element is disposed in the holding element  14  and comprises a spring element  76 . The spring element  76  is wave-shaped, with a bracing device  78  acting on the wave crest  82  of the wave-shaped spring element  76 . Via the bracing device  78 , the spring element  76  can be braced against the inflator  16 , thereby fixing the inflator  16  non-positively in the holding element  14 . The bracing device  78  comprises a screw element in the embodiment shown here. 
       FIGS.  22    a) and b) show a nineth embodiment of the holding element  14  and the inflator  16 . The holding element  14  includes a diffusor opening  80  in the discharge area  36  of the inflator  16 . The fixing element  24  in this embodiment is a latching seat  84 . The latching seat  84  is a seat for a latching element  86  disposed on the inflator  16 . In the embodiment shown here, each of the holding element  14  and the inflator  16  includes two latching seats  84  and two latching elements  86 . The latching element  86  is a spring system including spring elements  88  so that the inflator  16  can be released from the fixation in the holding element  14  by compressing the spring elements  88 . The inflator  16  is further fixed in the holding element  14  by the latching element  86  and the latching element seat  64  at a predetermined position. 
       FIG.  23    illustrates a tenth embodiment of the holding element  14  as well as of a corresponding inflator  16 . The fixing element  24  disposed in the holding element  14  comprises a fixing bolt  90  disposed in a fixing element seat  94 . In order to fix the inflator  16  at a predetermined position in the holding element  14 , the inflator  16  in the shown embodiment further comprises a fixing bolt seat  92 . In another embodiment not shown, the inflator can also be designed without such fixing bolt seat  92  and, for being fixed in the holding element  14 , can only be forced against the inner wall  42  of the holding element by the fixing bolt  92 . 
       FIGS.  24    a) to c) illustrate an eleventh embodiment of the holding element  14  and of a corresponding inflator  16 . The holding element  14  is configured as an airbag nut  100  in the embodiments of  FIGS.  24    b) and c). The airbag nut  100  can be sewn into the airbag via the securing elements in the form of airbag seats  23  in the area of the inflation mouth. In addition, the airbag seats  23  can be provided to be further used for securing the holding element  14  in the form of the airbag nut  100  to the module housing  12 , see  FIG.  24    b). Alternatively, additional securing elements  20 , such as securing bolts  21 , for securing the holding element  14  and the airbag to the module housing  12  can be provided on the airbag nut  100 , see  FIG.  24    c). The holding element  14  in the form of the airbag nut  100  comprises a female thread  98  as fixing element  24 . As an alternative to the airbag nut  100 , the holding element  14  can be a cage-like tube into which a female thread  98  is introduced to the inner wall (not shown). 
     The inflator  16  comprises a male thread  96  corresponding to the female thread  98  which allows to screw the inflator  16  into the holding element  14 . The male thread  96  can be disposed directly in an outer cover  104  of the inflator  16  (not shown) or on a generator nut  102  disposed on the inflator  16 . The generator nut  102  including the male thread  96  can be secured, for example by an adhesive connection such as by welding, to the outer cover  104  of the inflator  16 . 
       FIGS.  25    a) and b) illustrate a twelfth embodiment of a holding element  14  and a corresponding inflator  16 . The fixing element  24  is in the form of a spring element  76 . The inflator  16  can comprise, as shown in  FIG.  16   , a receiving nut  106  for receiving the spring element  76  by which receiving nut  106  the inflator  16  can be fixed at a predetermined position in the holding element  14 . The holding element  14  further comprises a positioning fixation device  62  which is a clamping bracket  108  in this case and forces the inflator  16  in the longitudinal direction axially against the end face  110  of the holding element  14 .