Abstract:
A device for electrically connecting a sensor element, which is accommodated in an engine add-on component, to evaluation electronics. The engine add-on component and the evaluation electronics are electrically connected to one another via contacting lines. The evaluation electronics is accommodated in a swiveling part of a hybrid holder which is movable relative to a part of the hybrid holder which is attached to the engine add-on component.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to the electrical connecting component between a sensor element and an evaluation circuit, in particular a sensor element used in an engine add-on component for internal combustion engines. 
       BACKGROUND INFORMATION 
       [0002]    Connecting technologies, which require a mutually defined and fixed connection of the components to be electrically contacted with one another, have been previously used for establishing an electrically conducting connection between a sensor element and an evaluation circuit which evaluates the signals of the sensor element. Known contacting methods for establishing an electrical connection are, among other things, bonding, gluing, and welding. Novel contacting methods such as, for example, three-dimensional bonding (3-D bonding), are not yet suitable in practice and hold great technical risks. 
         [0003]    The contacting methods described above for establishing an electrical connection between a sensor element and an evaluation circuit may result in great limitations with regard to the construction of a connecting component and great limitations with regard to a subsequent accessibility of the components electrically connected to one another such as, for example, a sensor element and an evaluation circuit. 
         [0004]    If, for example, an engine add-on component, such as, for example, a glow plug and an evaluation circuit are isolated from each other in a hybrid form, it is necessary to separate an electrical connection established by way of gluing, bonding, or welding again in order to disassemble an engine add-on component in the form of a glow plug for compression-ignition internal combustion engines. 
       SUMMARY OF THE INVENTION 
       [0005]    An object of the present invention is to provide an electrical connection between a sensor element and an evaluation circuit via a connecting element which enables the use of well-proven manufacturing methods despite constructions of engine add-on components which are becoming increasingly complex. 
         [0006]    Following the approach provided according to the present invention, a hybrid holder is used which, with one part, is lockable in a form-locked manner in the upper area of the engine add-on component, such as, for example, a glow plug, and whose other part which accommodates evaluation electronics (hybrid) may be raised around a swivel axis relative to the first part. The swiveling part of the hybrid holder, which is adjustable from a lowered position to a raised position, preferably includes a trough-shaped recess in which the hybrid is inserted. On one side of the trough-shaped recess, a plug connection component may be formed via which the hybrid holder and the accommodated evaluation electronics may be connected to an engine controller. 
         [0007]    While the first part of the hybrid holder may be accommodated in a form-locked manner on the engine add-on component, such as, for example, a glow plug for compression-ignition internal combustion engines, the other part of the hybrid holder, which contains the trough-shaped recess for accommodating the hybrid, is able to be turned upward from a lowered position into a raised position around a swivel axis, be it a film hinge, be it a rotary axis, or be it a tilting joint. The raised position of the further part represents the installation position on the engine add-on component. In this case, the hybrid holder may be connected to a signal line leading to the central engine controller via a conventional plug contact. 
         [0008]    If, however, the hybrid holder is mounted on the engine add-on component, it is locked in the upper area of the engine add-on component in the form of a glow plug and the part of the hybrid holder having a trough-shaped recess for accommodating the evaluation electronics is swiveled into a lowered position. In this mounting position, the lowered part of the hybrid holder and an upper front surface of the engine add-on component form a mounting plane. In this mounting plane, the hybrid may be inserted in the trough-shaped recess of the hybrid holder and electrically contacted on one side. The signal lines electrically contacted with the evaluation electronics in the form of a hybrid may then be contacted in the same mounting plane with electrical terminals which are led out of the engine add-on component at the front surface, for example. This approach offers considerable advantages with regard to easy accessibility of the electrical contact points on the engine add-on component and on the hybrid and, on the other hand, allows length and angle differences to be compensated. 
         [0009]    The swivel axis between the part of the hybrid holder, which is lockable in a form-locked manner on the engine add-on component, and the part of the hybrid holder which accommodates the evaluation electronics may be designed as a film hinge, a rotary hinge, or also as a lever hinge. To limit swiveling, stop cams and latches may be provided, for example. The part of the hybrid holder which is accommodated on the engine add-on component may be snapped or pressed onto same, which simplifies mounting considerably. 
         [0010]    If the hybrid holder is manufactured as an injection-molded plastic part, for example, then the swivel axis may be designed in an advantageous manner as a film hinge in the form of a taper of the plastic material. This represents a very simple and cost-effectively producible possibility to implement a swivel axis. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0011]      FIG. 1  shows a hybrid holder whose one part is latched on an engine add-on component and whose other part accommodating the evaluation electronics is shown in a lowered position as well as in a raised position. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    It is apparent from the representation in  FIG. 1  that an engine add-on component  10  has a flange  14  extending into its head area. The engine add-on component may be a glow plug, for example, such as is used in compression-ignition internal combustion engines. For example, combustion chamber pressure sensors may be accommodated in glow plugs which are to be connected to evaluation electronics  32  on the front side of engine add-on component  10 . 
         [0013]    It is apparent from the representation in  FIG. 1  that engine add-on component  10  includes a body  12  of an essentially cylindrical design, flange  14  running on the outer circumference of the component. Flange  14  includes a first ring surface  16  and a second ring surface  18 . One part of a hybrid holder  20  is detachably fastened to flange  14  of engine add-on component  10 . For this purpose, hybrid holder  20  has at least one first snap connection  22  or possibly a second snap connection  24 . Instead of snap connections  22  and  24  shown in the FIGURE, latches or the like may be provided to ensure detachable fastening between hybrid holder  20  and engine add-on component  10 . 
         [0014]    Snap connections  22  and  24 , shown in  FIG. 1 , each include mounting bevels  26  in order to make widening of snap connections  22  and  24  possible when they are slipped onto flange  14  when hybrid holder  20  is mounted on engine add-on component  10 . As soon as the recesses of first and second snap connections  22  and  24  have overlapped flange  14 , the protrusions of snap connections  22  and  24  grip second ring surface  18  in such a way that hybrid holder  20  is detachably fastened on engine add-on component  10 . 
         [0015]    In addition, hybrid holder  20  includes a set-up axis  28  which is designed in the representation according to  FIG. 1  as a film hinge due to a cross-section reduction  54 . Instead of cross section reduction  54 , it is also conceivable to design a rotary hinge or a tilting hinge as swivel axis  28 . A hybrid  32  is inserted into a receiving trough  30  of hybrid holder  20 . The top side of hybrid  32  is identified by reference numeral  32 . 1 , while the bottom side of hybrid  32  is identified by reference numeral  32 . 2 . Hybrid  32  situated in receiving trough  30  is secured against shifting by a first limit  56  and a second limit  58  in receiving trough  30 . 
         [0016]    An attachment point  40  for a plug contact is provided on hybrid holder  20  in the area of first limit  56 , hybrid holder  20  including accommodated evaluation electronics  32  being electrically connectable, in a raised position  44 , to an engine controller of an internal combustion engine, for example, via the attachment point. 
         [0017]    It is apparent from the representation in  FIG. 1  that hybrid  32  is easily accessible in lowered position  42  of receiving trough  30 . On top side  32 . 1  of hybrid  32 , contacting lines  34  may thus be connected to hybrid  32  at a contact point  36 . On the other hand, contacting lines  34  are electrically connected at a contact point  38  on the front side of engine add-on component  10 , a glow plug for example. It should be pointed out that the planes in which contact point  36  and contact point  38  are situated on engine add-on component  10  are oriented in the same way such that the front side of engine add-on component  10  and top side  32 . 1  of hybrid  32 , albeit having an offset, form one plane which ensures good accessibility of contact points  36  and  38 . After establishing the electrical contact of the sensor element contained in engine add-on component  10  with hybrid  32  via contacting lines  34 , the part of the hybrid holder which includes receiving trough  30  is moved from lowered position  42  into raised position  44  depicted in a dashed line. In the process, a stop cam  46 , which is provided on a top side  50  of hybrid holder  20 , moves into a stop position  46 . 1  (depicted in a dashed line) and hits a stop  48 , which optionally limits the rising motion, stop  48  being also provided on top side  50  of hybrid holder  20 . As mentioned previously, set-up axis  28  is represented by a cross-section reduction  54  between top side  50  and bottom side  52  of hybrid holder  20  in this exemplary embodiment. Engine add-on component  10  in the form of a glow plug includes a hollow space  60  through which the sensor element is formed (not depicted in the FIGURE). The sensor element accommodated above hollow space  60 , which may be a combustion chamber pressure sensor, for example, is connected at contact point  38  to contacting lines  34  which in turn are electrically connected at contact point  36  to top side  32 . 1  of hybrid  32 . 
         [0018]    If the part of hybrid holder  20 , which includes receiving trough  30 , is moved from lowered position  42  into raised position  44 , attachment point  40  for a plug contact situated in lowered position  42  in the area of first limit  46  is moved from the vertical position into the horizontal position in such a way that the attachment point is also easily accessible from above. In the event of disassembly, i.e., pulling the plug from attachment point  40 , this simplifies accessibility considerably. If, after the plug is pulled from attachment point  40  of hybrid holder  20 , the part of hybrid holder  20  containing receiving trough  30 , which is in raised position  44 , is again moved into lowered position  42 , contact points  36  and  38 , and contacting lines  34 , which connect the sensor element to evaluation electronics  32 , are easily accessible since they are situated in one plane. The plane is defined by the front side of engine add-on component  10 , in which contact point  38  is situated, and by top side  32 . 1  of hybrid  32 . Stop  48  on top side  50  of hybrid holder  20  is used for limiting the swivel path of the moveable part of hybrid holder  20  from lowered position  42  into raised position  44 . In addition, the swivel process into raised position  44  may be limited via stop  48  in cooperation with stop cam  46  on top side  50  of the moveable part of hybrid holder  20 . Instead of snap connections  22  and  24  shown in  FIG. 1 , hybrid holder  20  of engine add-on component  10  in the form of a glow plug may also be snap connected. 
       LIST OF REFERENCE NUMERALS 
       [0000]    
       
           10  engine add-on component 
          (glow plug) 
           12  body 
           14  flange 
           16  first ring surface 
           18  second ring surface 
           20  hybrid holder 
           22  first snap connection 
           24  second snap connection 
           26  mounting bevel 
           28  set-up axis 
           30  receiving trough 
           32  hybrid (evaluation electronics) 
           32 . 1  top side hybrid 
           32 . 2  bottom side hybrid 
           34  contacting lines 
           36  contact point hybrid 
           38  contact point of engine add-on component 
           40  attachment point for plug 
           42  lowered position 
           44  raised position 
           46  stop cam 
           46 . 1  raised position stop cam 
           48  stop 
           50  top side 
           52  bottom side 
           54  cross-section reduction 
           56  first limit 
           58  second limit 
           60  hollow space engine add-on component