Abstract:
The invention relates to an ignition device ( 7 ) for a safety system, particularly an airbag, a belt tightener or similar in vehicles. According to the invention, means of ignition are arranged in a housing and can be activated by input signals which are fed via supply lines ( 3,4 ). At least one electronic component ( 10 ) is connected to the supply lines ( 3,4 ).

Description:
TECHNICAL DOMAIN  
         [0001]    The invention relates to an ignition device for a safety system, especially an airbag, a belt tensioner, or the like in motor vehicles according to the features of claim  1 .  
         PRIOR ART  
         [0002]    Austrian utility model AT 000522U1 discloses an ignition device for a safety system which can be a safety belt tensioner here. In this ignition device there are ignition means in the housing, the ignition means receives signals for activation (i.e. for ignition) via feed lines.  
           [0003]    To protect against voltages or currents which are formed by incident radiated electromagnetic fields or land-line HF waves, at least one electronic component is connected to the feed lines, by which the incident radiated voltages or currents or HF waves are attenuated to the extent that they can no longer trigger misfires of the ignition means.  
           [0004]    In this known ignition device it is necessary to place the electronic component within the housing of the ignition device since it may only occupy little installation space. For the case in which the electronic component is faulty, it is necessary to replace the entire ignition device.  
         DESCRIPTION OF THE INVENTION  
         [0005]    The object of this invention is therefore to improve the known ignition device such that the indicated disadvantages are eliminated.  
           [0006]    This object is achieved by the features of claim  1 .  
           [0007]    As claimed in the invention it is provided that at least one electronic component is located outside the housing of the ignition device. In this way the electronic component can be located where there is adequate space. In addition, the space requirement for at least one electronic component is thus no longer subject to limitations so that it in fact can be optimally configured with respect to its arrangement and its function while simultaneously maintaining its advantageous effects, specifically the effective prevention of misfires.  
           [0008]    The electronic components can be coils (inductances), capacitors, varistors and the like. It also is conceivable for several of these components to be used in combination.  
           [0009]    In a development of the invention the electronic component is connected to the feed lines via at least partially electrically conductive lines. This increases the flexibility of installation, since first the feed lines are connected to carrier means and then the electronic component is connected to the carrier means (or vice versa). Moreover different connecting techniques can be used in the connection between a feed line and the carrier means on the one hand and the carrier means and the component on the other. The optimum matching of connecting techniques ensures that both a durable connection can be established and also especially the electronic component is not damaged by the connection.  
           [0010]    In one especially advantageous embodiment the carrier means are made as stampings. By execution as stampings it is on the one hand possible to provide fixing means both for the electrically conductive areas of the feed lines and also for the electronic component. Furthermore, by using a stamping the strength is increased and an installation site for the electronic component is formed. It is especially important to increase strength, since feed lines are in general flexible round conductors. Based on their flexibility, it is necessary that at the site at which the component is inserted onto a feed line a minimum stiffness is attained. This minimum stiffness is further increased by the carrier means having a nonconducting carrier in the manner as claimed in the invention. The stiffness also is increased by a nonconductive carrier which consists, for example, of a plastic component.  
           [0011]    In a development of the invention at least the electronic component is surrounded by a housing. In this way the electronic component effectively is protected against ambient effects (especially mechanical stress and moisture and electrically conductive particles). Of course, the carrier means and the feed lines directed to the electronic components also can be surrounded by the housing. The housing itself can have either fasteners with which it is fixed at an installation site or can have a shape with which it can be fixed in position.  
           [0012]    In one development of the invention the housing, which surrounds the electronic components, can be produced by an injection molding process. After connecting the electronic component to electrically conductive areas of the feed lines, especially using the carrier means, the prefabricated unit can be coated by an injection molding process (or optionally by other likewise usable processes) in order to produce the housing. An injection molding process works especially well since with it the housing can be quickly manufactured and reliably surrounds the participating components, especially also the ends of the feed lines, so that mechanical strength is clearly improved. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    One embodiment of the invention to which it is however not limited is described below based on the steps of a production process and is explained in the figures.  
         [0014]    [0014]FIG. 1 shows stampings,  
         [0015]    [0015]FIG. 2 shows stampings with the carrier,  
         [0016]    [0016]FIG. 3 shows stripped feed lines,  
         [0017]    [0017]FIG. 4 shows stampings and the carrier which are inserted into the stripped areas,  
         [0018]    [0018]FIG. 5 shows the installed electronic component,  
         [0019]    [0019]FIG. 6 shows the electronic component surrounded with a housing. 
     
    
     IMPLEMENTATIONS OF THE INVENTION  
       [0020]    [0020]FIG. 1 shows by way of example shaped stampings via which the electronic component can be connected to electrically conductive areas of feed lines.  
         [0021]    [0021]FIG. 2 shows that the stampings  1 , which are both electrically conductive, are fixed at a distance from one another using an electrically nonconductive support  2 . The support  2  can be a plastic part into which the stampings  1  are inserted. But it also is conceivable for the stampings  1  to be fixed in positions at a distance and for the carrier  2  to be produced, for example, in an injection molding process surrounding the stampings  1 .  
         [0022]    In FIG. 3 two feed lines  3 ,  4  are shown which are stripped so that the conductors  5  and  6  are exposed. The stripped areas can be located anywhere between a schematically shown ignition device  7  and a likewise schematically shown control unit  8  from which the signals for activation of the ignition device originate. It should be mentioned here that the electrical feed lines need not necessarily be made as round flexible conductors. They also can be, for example, rigid flat strip lines or flexible film lines.  
         [0023]    [0023]FIG. 4 shows that the stripped areas are joined to the stampings  1  and are, for example, soldered there. For fixing in position in front of the connection the stampings have bends  9 , by which the conductors  5  and  6  are held on the stampings  1 . Instead of soldering it is conceivable here for the conductors  5  and  6  to be crimped to the stampings  1  via the bends  9 .  
         [0024]    [0024]FIG. 5 shows the premounted unit now is provided with an electronic component  10  which is electrically in contact with the stampings  1 . Here it is shown that the electronic component  10  is connected parallel to the two feed lines  3  and  4 . Of course, the invention also can be implemented when an electronic component is connected within a feed line in series to this feed line. In addition, it is possible to connect one component (or several components) in parallel and another (or other components) in series to the feed lines.  
         [0025]    [0025]FIG. 6 shows that the electronic component  10  including the stampings  1  and the carrier  2  are surrounded by a housing  11 . Here this housing  11  is shaped or is located around the premounted unit which is shown in FIG. 5 such that the ends of the feed lines  3  and  4  are surrounded by the housing  11 . Thus, a unit is formed which has required mechanical strength and which protects the sensitive electronic component  10 . The housing  11  can completely surround all participating components, it also can be conceivable, for example, for the carrier  2  to project out of the housing  11  and to be used for attachment purposes.  
         [0026]    In another alternative embodiment which is not shown, it is conceivable that the feed lines  3  and  4  point in the direction of the ignition device  7  or also in the direction of the control unit  8 , are not made as feed lines, but as contact partners (especially pins or sleeves), these contact partners being surrounded in a structurally suitable manner by the housing  11  in order to implement an electrical plug connection. Such an electrical plug connection has the advantage that the electronic component  10  can be located outside the housing of the ignition device, but also in the vicinity in space. Alternatively it is possible for the electronic component  10  to be located within the electrical plug connection on the control unit  8 . In addition, the feed lines  3  and  4  which run from the electronic component on the one hand in the direction of the ignition device  7  and on the other in the direction of the control unit  8  can be the same or also different.