Abstract:
The invention relates to a sensor comprising a sensor element ( 1 ) for detecting a physical variable, said sensor comprising two electric contact surfaces ( 2 ), and comprising a sensor body ( 3 ), on one end of which the sensor element ( 1 ) and on the other end of which a contact carrier ( 4 ) is located, wherein the contact carrier ( 4 ) supports at least two insulation displacement contacts ( 5 ) suitable for producing an insulation displacement connection ( 6 ) to an electric connecting cable ( 7 ), wherein each contact surface ( 2 ) is connected to an insulation displacement contact ( 5 ). The invention also relates to a sensor assembly. The combination of the insulation displacement technology with the sensor makes it possible for the sensor and the cable tree of a motor vehicle, for example, to be contacted in a simple manner.

Description:
TECHNICAL FIELD 
   This patent application describes a sensor comprising a sensor element for detecting a physical variable, where the sensor is in a sensor body. This patent application also describes a sensor assembly. 
   BACKGROUND 
   Sensors may be used to measure temperatures in the automotive industry. Sensors may be integrated into the electronic system of a motor vehicle during the course of production. 
   Some sensors have a permanently mounted connecting cable located at the sensor. These connecting cables may be woven into a cable tree in the motor vehicle. Some sensors contact cables in a motor vehicle via a plug and receptacle. The plug is mounted on the sensor and the receptacle is mounted in a corresponding cable of the cable tree. 
   SUMMARY  
   A sensor is described that comprises a sensor element for detecting a physical variable. The sensor element comprises two electric contact surfaces. The sensor element also comprises a sensor body, on one end of which the sensor element is located and on the other end of which a contact carrier is located. The contact carrier supports at least two insulation displacement contacts for producing an insulation displacement connection to an electric connecting cable. Each contact surface is connected to an insulation displacement contact. 
   The combination of a sensor with the possibility of using the insulation displacement technology for contacting with an electric connecting cable enables an existing cable to be electrically contacted with the sensor relatively easily. A particular advantage of the insulation displacement technology is that the cable to be contacted with the sensor or the electric connecting cable to be contacted with the sensor can pass through the insulation displacement contacts of the sensor, so that serial contacting of the cable with multiple sensors or other components can be easily obtained. 
   In addition, a sensor assembly is described in which each insulation displacement contact of the sensor is connected to an electric connecting cable. 
   In addition, a sensor assembly is described that comprises a plurality of sensors, where each such sensor is structured as described above. In this process, one insulation displacement contact of each sensor is connected to one and the same electric connecting cable. The individual insulation displacement contacts of the sensors are, in a sense, connected in series to one and the same electric connecting cable. As a result, for example, a shared supply or return cable or a shared cathode or anode for the sensor element can be implemented in the sensor assembly. Each of the remaining insulation displacement contacts is connected to another electric connecting cable. Thus, the return cable of the sensors is executed separately. 
   As a result of insulation displacement technology, a fork is essentially integrated into the connecting cable to be connected to the sensor. The connecting cable can continue and be connected to other components at other locations. 
   An advantage of the sensor assembly comprising multiple sensors is that, as a result of connecting sensors in series to a single electric connecting cable, cable material as well as circuitry costs can be saved. 
   The insulation displacement contacts can, for example, be designed to include recesses in which two opposing blades are disposed. The blades have a sharp edge suitable for cutting the insulation material of an electrically insulated connecting cable and contacting the electrically conductive material under the isolation, such as copper wire. 
   Accordingly, a sensor assembly is also described in which a connecting cable provided with insulation is inserted into an insulation displacement contact in such a way that the insulation is cut in two by the blades of the insulation displacement contact and the blades contact the electric conductor, such as a copper wire. 
   The sensor can also comprise a contact lid, which comprises means for pressing an electric connecting cable into the space between two blades of a recess in an insulation displacement contact and, further, means of fastening the connecting cable in the recess of the insulation displacement contact. 
   Two different functions can be combined via the contact lid. First, the electric connecting cable can be pressed into the recess by playing the lid onto the insulation displacement contact. This establishes the electric contact between the electric connecting cable and the insulation displacement contact. The contact lid also makes it possible to mechanically fasten the connecting cable to the insulation displacement contact and/or the contact carrier. 
   In an embodiment, the means for pressing an electric connecting cable into the space between two blades can be executed as a pressing fin that projects downward from the contact lid. A possible means of fastening the connecting cable in the recess is, for example, to provide an eye on the contact lid, which latches into a snap hook on the contact carrier. The latching takes place when the contact lid is pushed onto the contact carrier. The insulation displacement contacts can be provided with contact elements that are permanently connected to contact cables disposed on the sensor element. 
   It is also possible to connect the insulation displacement contacts to the sensor element via electrically conductive connections, wherein the insulation displacement contact and the electrically conductive connections are an integral component of a punched panel. Such a punched panel can be a lead frame, for example. 
   To protect the insulation displacement contact against moisture, it is advantageous to provide a sealing cap that can be pushed onto the contact carrier. 
   Protection against moisture can also be achieved by providing both the contact lid and the contact carrier with sealing elements, which can be elastically shaped by mounting the contact lid onto the contact carrier, thereby sealing the insulation displacement contact against moisture. 
   To improve contact between the sensor element and the medium surrounding the sensor, such as the air, the temperature of which is to be measured, it can be advantageous to locate the sensor element in a hole in the sensor body. As a result, the sensor element is protected on two sides against mechanical damage. The sensor element is freely accessible from the other two sides, so that, for example, air or fluid can flow past it and come into direct contact with it. 
   The sensor body can also comprise a flange in the region of the contact carrier, which is suitable for mounting the sensor to the wall or in a hole in a wall of a housing. For mounting the sensor, it is also advantageous to provide it with a bayonet catch. 
   The flange makes it possible to seal the housing, in which the sensor is to be mounted, with the flange. 
   The bayonet catch allows for simple and secure connection of the sensor to a correspondingly shaped hole in a housing. 
   Moreover, it is advantageous to provide a bus system in the sensor. The advantage of such a bus system is that it can be connected, via multiple cables, to a corresponding bus monitoring device or bus control device. Several sensors provided with a bus system can be connected to the control device via the single multiple cable. As a result, the complexity of cable installation can be significantly reduced. 
   Accordingly, a sensor assembly is described which comprises a plurality of sensors, wherein each sensor is provided with an integrated bus system. In addition, a plurality of bus cables are provided, wherein each bus cable is connected to an insulation displacement contact of each sensor. This results in a series connection of a plurality of sensors, all of which can be controlled and/or read through one and the same plurality of bus cables. 
   In particular, it is no longer necessary to install an extra pair of connecting cables for each sensor. 
   To further secure the electric connecting cable to be connected to the sensor, it is possible to further the sensor with a contact safety. Such a contact safety can, for example, be disposed on the contact carrier. Suitable for this purpose are, for example, crimps, which can be closed with a special device (such as a pair of crimping pliers). However, it is also possible to provide two simple, straight panels, which are oriented upward on the contact carrier. After the electric connecting cable has been placed into the insulation displacement contact, the panels are folded over, thereby fastening the electric connecting cable. This results in an advantageous relief of tensile stress on the connecting cable. 
   In the following, embodiments are explained in greater detail with reference to corresponding figures. 

   
     DESCRIPTION OF THE DRAWINGS 
       FIG. 1A  shows, as an example, a sensor in a first side view. 
       FIG. 1B  shows the sensor from  FIG. 1A  in a second side view. 
       FIG. 2A  shows the sensor from  FIG. 1A  with the contact lid closed. 
       FIG. 2B  shows the sensor from  FIG. 1B  with the contact lid closed. 
       FIG. 3  shows, as an example, another sensor in schematic cross-section. 
       FIG. 4  shows, as an example, another sensor in schematic cross-section, which is installed into a housing. 
       FIG. 5  shows, as an example, another sensor with an outer seal against moisture. 
       FIG. 6A  shows, as an example, another sensor with an inner seal against moisture in a first side view, with the contact lid closed. 
       FIG. 6B  shows the sensor from  FIG. 6A  in a top view, with the contact lid open. 
       FIG. 6C  shows the lid of the sensor from  FIG. 6A  in a top view. 
       FIG. 7  shows, as an example, a first sensor assembly. 
       FIG. 8  shows, as an example, a further sensor assembly. 
       FIG. 9  shows, as an example, a further sensor assembly with a bus system. 
   

   DETAILED DESCRIPTION 
     FIGS. 1A and 1B  show a sensor with a sensor body  3 , at the lower end of which a sensor element  1  is disposed in a hole  22 . The sensor element  1  is used to detect a physical variable and can be designed to measure temperature, for example. The sensor element  1  has contact surfaces  2 , at which the sensor element  1  can be electrically contacted through electrically conductive cables  17 . The sensor element is encased by a sealing compound  15 . At its other end, the sensor body  3  is provided with a contact carrier  4 , which supports two insulation displacement contacts  5 . Each of the insulation displacement contacts  5  contains a recess  8 , within which two opposing blades  9  are disposed. 
   By inserting an electric connecting cable  7 , which is provided with insulation  28 , into the recess  8 , the insulation  28  can be cut in two by the blades  9  and the electric connecting cable  7  can be contacted. The contact lid  10  is provided with which the electric connecting cable  7 , by application of force F, can be pressed into the recesses  8  of the insulation displacement contacts  5 . The electric connecting cable  7  is pressed in via pressing fins  11 , which are disposed on the contact lid  10 . 
   The contact lid  10  also comprises an eye  12 , which can latch into a snap hook  13  of the contact carrier  4 . As a result, pushing the contact lid  10  simultaneously causes an electrical and mechanical connection to be established between the electric connecting cable  7  and the sensor. 
   The sensor also comprises a flange  23 , which is provided with a seal  31 . As a result, the sensor can also be installed into a housing or into a wall of a housing. 
     FIGS. 2A and 2B  show the sensor from  FIGS. 1A and 1B  with the contact lid  10  closed. By closing the contact lid  10 , an insulation displacement connection  6  can be established, so that the electric connecting cable  7  is connected to the sensor. 
   Each contact surface  2  is connected to an insulation displacement contact  5  via an electrically conductive connection  17 . 
   The sensor body  3  of the sensor also comprises a bayonet catch  25 , which allows for simple and secure connection of the sensor to the wall of a housing. 
     FIGS. 2A and 2B  also indicate how the pressing fins  11  of the contact lid  10  press the electric connecting cable  7  into the recess  8  of the insulation displacement contact  5  (see  FIGS. 1A and 1B  for displacement contact  5 ). 
     FIG. 3  shows a sensor in which the insulation displacement contacts  5  are provided with contact elements  14 . The sensor element  1  is provided with contact cables  16 , which establish electrical contact between the sensor element  1  and the contact elements  14  and, therefore, with the insulation displacement contacts  5 . The contact between the contact cables  16  and the contact elements  14  can be established via soldering or welding, for example. 
     FIG. 4  shows a sensor that is installed in a housing  24  via the flange  23 . The insulation displacement contacts  5  as well as the electrically conductive connections  17  between the insulation displacement contacts  5  and the sensor element  1  are an integral component of a punched panel  18 . Such a panel  18  can be a lead frame, for example. The panel  18  is produced by punching, and subsequently the sensor element  1  is electrically connected to the panel  18  via soldering. The sensor element  1  can be an NTC temperature sensor, for example. 
     FIG. 5  shows a sensor, which is provided with a sealing cap  19 . The sealing cap  19  prevents moisture from penetrating externally into the insulation displacement contact  6 . The sealing cap  19  is made of waterproof material. It can comprise rubber, for example. The sealing cap  19  is pushed onto the contact carrier  4  from above. Beads  33  engage a recess  34  in the contact carrier  4 , thereby sealing the insulation displacement connection  6 . The sealing cap  19  also comprises an opening, through which the electric connecting cable  7  can reach the insulation displacement connection. 
   An advantage of this type of sensor, which is sealed against moisture, is that it can be used in, e.g., an evaporator of an air-conditioning system. 
   The sensor can also be provided with an interior seal. Such an interior seal is depicted in  FIGS. 6A to 6C .  FIG. 6A  shows a sensor with a closed contact lid  10 , corresponding to  FIG. 2A . Sealing elements  21  of the contact lid  10  are disposed on the underside of the pressing fins  11 . In addition, sealing elements  20   b  of the contact carrier  4  are disposed below the electric connecting cables  7 . By pressing the contact lid  10  onto the contact carrier  4 , the seals  21 ,  20   b  are elastically shaped and, as a result, the insulation displacement connection  6  is sealed against the effects of external moisture. 
     FIG. 6B  shows the contact carrier  4  from  FIG. 6A  in a top view. One can discern that a seal  20 A is worked into the contact carrier  4  along the outer edge of the contact carrier  4 . Recesses  35 , in which the electric connecting cables  7  run, are located in the contact carrier  4 . At the location of the recesses  35 , the contact carrier  4  features recessed sealing elements  20   b,  which are also visible in  FIG. 6A . The sealing elements  20   a  are compressed by pressing the contact lid  10  onto the contact carrier  4 , thereby establishing the seal. 
   According to  FIG. 6B , each of the insulation displacement contacts  5  is provided with blades  9  aligned with one another, which enables an insulation displacement connection  6  to be executed with increased certainty of contact, because each electric connecting cable  7  is connected to two pairs of blades  9 . 
     FIG. 6B  also shows a contact safety  32 , which is depicted in the form of panels protruding upward from the contact carrier  4 . After the electric connecting cable  7  has been placed into the recess  35  of the contact carrier  4 , the panels are folded inward and, therefore, the electric connecting cable  7  is mechanically fastened for the purpose of relieving tensile stress. 
     FIG. 6B  also shows a bus system  26 , which is integrated into the contact carrier  4  and electrically connected to the insulation displacement contacts  5 . 
     FIG. 6C  shows the contact lid  10  from  FIG. 6A  in a top view. The sealing elements  21  disposed below the pressing fins  11  are visible. 
     FIG. 7  shows a sensor assembly, in which a sensor  27  is connected to two electric connecting cables  7 , wherein the insulation displacement contacts of the sensor  27  are connected to the electric connecting cables  7 . 
     FIG. 8  shows another sensor assembly, in which two sensors  27   a,    27   b  are connected to an electric connecting cable  7  as well as to other electric conductors  29 . The electric connecting cable  7  passes through the sensor  27   a  and connected to both sensor  27   a  and sensor  27   b.  As a result, a common return cable for the two sensors  27   a,    27   b  can be realized. The supply cable is realized through an additional electric connecting cable  29 , wherein each sensor  27   a,    27   b  is connected to an additional electric conductor  29 . 
   In addition, a cable guide  36  can be provided, which simplifies the parallel placement of the cables  7 ,  29 . 
     FIG. 9  shows a sensor assembly with sensors  27   a,    27   b,    27   c,  wherein each sensor is provided with a bus system. Each sensor is connected to bus cables  30 . The bus cables  30  run from sensor  27   a  to sensor  27   b,  and from there continue to sensor  27   c.  A dedicated bus cable  30  for each sensor  27   a,    27   b,    27   c  is not necessary. Instead, each bus cable  30  can be easily connected to multiple insulation displacement contacts of different sensors  27   a,    27   b,    27   c.