Abstract:
A device is proposed for fastening a post in a terminal clamp, having at least one terminal clamp for connection to a battery terminal, at least one electronics unit or measuring element capable of being connected to the terminal clamp, at least one post for connecting a battery cable, the post being mechanically fastened to the terminal clamp via a connection, and having at least one insulating element between the post and the terminal clamp, means being provided for the rotational securing of the post.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a device for fastening a post in a terminal clamp. 
     BACKGROUND 
     The present invention is based on a device for fastening a post in a terminal clamp of the type described herein. A device of this type is known from German Patent DE 10 2004 046 855 B3. In order to fasten a measuring resistor to the terminal clamp and to fasten one end of a ground wire to the measuring resistor, a post is known having an insulating sheath, the post being connected to the measuring resistor by a press-fit connection or rivet connection. 
     The object of the present invention is to simplify the connection between the post and the terminal clamp while achieving a high degree of mechanical strength. This object is achieved by the features of the present invention described herein. 
     SUMMARY 
     In comparison with the prior art, the device according to the present invention having the features described herein has the advantage that it increases mechanical strength without relying on a rivet connection or press-fit connection. This is achieved in that means are provided for rotationally securing the post. In particular, these means absorb forces that would cause a rotation of the post. In this way, tensile forces on the battery cable are dissipated via the terminal clamp. The proposed solution can also be realized as a preassembled terminal clamp having a post. Via the post, a mechanical bond to the terminal clamp is achieved in a simple manner, with simultaneous electrical insulation. 
     In a useful development, as a means for rotational securing a receptacle is provided in the terminal clamp that cooperates with a receptacle contour. This receptacle contour is preferably star-shaped or rectangular, so that corresponding forces can be uniformly absorbed. 
     In a useful development, the insulating element is made of a flexible material, preferably plastic or silicone. This enables a simple joining of the post to the insulating element, the terminal clamp, and, if present, the measuring element, with tolerance compensation if required. 
     In a useful development, the insulating element is formed as an injection-molded part. This may be sprayed directly onto the terminal clamp and the post, so that these parts are molded together to form a unit. In this way, a joining process may be omitted. In addition, the precision of the positioning of the post in the terminal clamp is increased. 
     In a useful development, the insulating element is made up of a coating of the post, preferably an insulating lacquer or some other material that electrically insulates the surface of the post. The post is subsequently mounted in the terminal clamp, for example by pressing the post into the terminal clamp. 
     In a useful development, the post is provided with a preferably circumferential collar for the at least partial accommodation of the measuring element. In this way, the post simultaneously acts as a mechanical support surface for the measuring element, thus increasing the mechanical strength of the system. Here the outer diameter of the collar is usefully smaller than the outer diameter of the insulating element. This achieves a reliable electrical insulation between the terminal clamp and the post. 
     Further useful aspects of the present result from the description herein. In this regard, a plurality of exemplary embodiments of the device for fastening a post in a terminal clamp are shown in the drawings and are described in more detail below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a schematic representation of the overall assembly, having an insulated post situated in a terminal clamp. 
         FIG. 2  shows a second exemplary embodiment having an insulating element formed by molding. 
         FIG. 3  shows a further exemplary embodiment having a coated post. 
         FIG. 4  shows a detail view of the terminal clamp for accommodating the post. 
         FIG. 5  shows the post of  FIG. 4 . 
         FIG. 6  shows a partially sectional perspective view of the connection between the terminal clamp and the post. 
         FIG. 7  shows a perspective view of a battery measuring clamp having a post integrated in the terminal clamp. 
         FIG. 8  shows a perspective view corresponding to  FIG. 7  in partial section. 
         FIG. 9  shows a schematic diagram of the three-part design of the battery measuring clamp. 
     
    
    
     DETAILED DESCRIPTION 
     A schematically shown terminal clamp  10  has a receptacle  20  in which a post  14 , surrounded in its lower area by an insulating element  18 , is situated so as to be electrically insulated from terminal clamp  10 . This post  14  contacts a measuring element  16  in an electrically conductive manner. Below the underside of measuring element  16 , in the area of receptacle  20  there may be situated an insulation  19 , in order to ensure that at this location in particular there is no electrically conductive contact between measuring element  16  and terminal clamp  10 . This insulation  19  may also be a component of insulating element  18 . Via post  14 , a battery cable  12  is connected electrically and mechanically to terminal clamp  10 . 
     The exemplary embodiment shown in  FIG. 2  differs from that shown in  FIG. 1  only in that it has a different embodiment of insulating element  18 . This element is formed as an injection-molded part in such a way that both terminal clamp  10  and post  14  are molded to form a unit. Here the underside of measuring element  16  is situated on the upper side of insulating element  18 . 
     Post  14  is used to fasten battery cable  12 . For this purpose, for example a threading (not shown) is provided. The cable shoe of battery cable  12  is placed around post  14  and is subsequently fastened by a nut. Measuring element  16 , which is preferably formed so as to be flat, is also placed around this post  14 . Post  14  is in turn mechanically connected to terminal clamp  10  via insulating element  18 , by a suitable connection  24 . In the exemplary embodiment shown in  FIG. 1 , for example, insulating element  18  is formed as a sheath-shaped element. For this purpose, insulating element  18  must have sufficient flexibility to allow post  14  and terminal clamp  10  to be joined. The flexibility of insulating element  18  also provides tolerance compensation. Latch mechanisms may also be used to ensure that post  14  is securely positioned in terminal clamp  10 . The material of insulating element  18  is preferably a plastic or an elastomer (for example silicone). In the exemplary embodiment shown in  FIG. 2 , insulating element  18  is realized as an injection-molded part. For this purpose, post  14  and terminal clamp  10  (positioned at a distance from one another) are molded with an insulating plastic, resulting in insulating element  18 . Preferably, the upper edge of insulating element  18  extends somewhat past the upper side of terminal clamp  10 , so that it is ensured that measuring element  16  is situated so as to be electrically insulated from terminal clamp  10  at the location of post  14 . 
     In the exemplary embodiment shown in  FIG. 3 , post  14  is provided in its lower region with a coating  18 ″. In the region that is to be insulated, post  14  is provided with a lacquer or with some other suitable insulating surface. Post  14  coated in this way is subsequently mounted in terminal clamp  10 , for example pressed in. 
       FIG. 4  shows receptacle  20  of terminal clamp  10  in more detail. An essentially star-shaped receptacle contour  14  can be seen that is formed in such a way that rotation of post  14  on the one hand, as well as movement of post  14  downward in the axial direction, is reliably prevented. The associated post  14  is shown in  FIG. 5 . Correspondingly, the post  14  also has a fastening contour  40  that is star-shaped. Above fastening contour  40 , a radially circumferential collar  38  is provided. The outer diameter of collar  38  is preferably larger than that of fastening contour  40 . The components shown in  FIGS. 4 and 5  are shown in the assembled state in  FIG. 6 . Insulating element  18  is formed in such a way that an electrical insulation is achieved between terminal clamp  10  and post  14 . In addition, the outer radius of the upper side of insulating element  18  is greater than the outer radius of collar  38 . This reliably achieves an insulation between terminal clamp  10  and post  14 . 
     In order to prevent rotation, receptacle contour  42  may, for example, be made rectangular, prismatic, triangular, or roughly rectangular, having one or two rounded-off side surfaces. Advantageously, receptacle contour  42  may have counter-surfaces in a plane perpendicular to the axial direction of post  14 , so that post  14  may be mounted in a defined axial position, or receptacle contour  48  may also absorb forces acting in the axial direction. 
     In the exemplary embodiment according to  FIG. 7 , terminal clamp  10  is shown, which may be connected to a terminal (not shown) of a battery, for example a battery of a motor vehicle. For this purpose, the limbs (not shown in more detail) of terminal clamp  10  can be moved towards one another in such a way that they clasp the battery terminal. The system also includes measuring element  16 . Measuring element  16  is immediately connected mechanically and electrically to terminal clamp  10  on the one side by a compression  34  using clinching. At the location of compression  34 , terminal clamp  10  has an opening having chamfering on its rear side. The terminal of measuring element  16  is pressed into this opening using clinching in such a way that an undercut of measuring element  16  is formed in the area of the chamfering. This creates a quasi-riveted connection of terminal clamp  10  to measuring element  16 . 
     On the right side, receptacle  20  of terminal clamp  10  is shown, which is used to fasten post  14 . For this purpose, post  14  is, for example, made cylindrical, and extends upwardly perpendicular to the flat plane of measuring element  16 . Insulating element  18  is situated between post  14  and terminal clamp  10 , radially surrounding post  14 . The depicted system ensures that the battery current between post  14  for connecting battery cable  12  and the clamp connected to the battery terminal actually flows via measuring element  16  and is not short-circuited. A corresponding opening in measuring element  16  is matched to the outer diameter of post  14 . Measuring element  16  lies partly on radially expanding collar  38  on post  14 , and partly also on the upper side of insulating element  18 , which is formed as a sheath. The upward-protruding side of post  14  may be provided with a threading (not shown) in order to fasten a cable shoe of a battery cable  12 , preferably the ground cable, using screwed connections. In the region of post  14 , measuring element  16  is surrounded by a housing  30  only laterally, while the surface of measuring element  16  is exposed. 
     Measuring element  16  is guided in the direction of housing  30 , into its interior. The actual measuring element is situated there, for example an electrical resistor made of a particular material such as manganin. Inside housing  30  there is also situated an electronics unit (not shown) that detects the voltage drop at measuring resistor  16  and further evaluates it. In addition, on the basis of further data such as battery voltage, temperature, or the like, battery state quantities such as state of charge (SOC) or aging (state of health: SOH) can be determined. These data can be forwarded to further control devices, such as an energy management control device, via a data line (not shown) connected via a plug  32 . The additional supply voltage can also be supplied via this plug  32 . 
     Measuring element  16  is led out from housing  30  at the side facing away from post  14 . The electrical contacting to terminal clamp  10  also takes place at this location, in a compression  34  preferably obtained by clinching. However, it is essential that the electrical contacting between measuring element  16  and terminal clamp  10  should first take place, relative to the actual measuring resistor, at the side facing away from post  14 . In this way, the current from the battery terminal is conducted via terminal clamp  10 , the connection at the left connecting point of measuring element  16 , and the measuring resistor situated inside housing  30 , to post  14 , to which battery cable  12  is then to be connected. 
       FIG. 9  shows a three-part battery sensor design. This is preferably made up of terminal clamp  10 , electronics unit  22 , and cable terminal  48 . As an example, terminal claim  10  and electronics unit  22  are fastened to one another by connection  24  and compression  34  as already explained. The structural and connection technology is optimized by partitioning the battery sensor into three parts, namely terminal clamp  10 , electronics unit  22 , and cable terminal  48 . In the production sequence, the joining of these three partitions does not take place until the end of the sequence. This is intended to increase flexibility insofar as adaptation to a wide range of installation spaces is made possible merely by exchanging terminal clamp  10  and/or cable terminal  48 . Changes to electronics unit  22  are not necessary. All three units  10 ,  22 ,  48  may be manufactured separately from one another and connected to one another only at the end of the production process. 
     The complete assembly may be integrated into motor vehicle batteries that are commercially standard in Poland, or extends somewhat beyond these. The connection technology used between the three units  10 ,  22 ,  48  may be selected such that they may be detached from each other. This creates the possibility of removing or attaching individual units without having to dismount the overall sensor from the battery or to mount it thereon. A significant advantage is that it becomes possible to remove cable terminal  48  without terminal clamp disassembly. 
     The device for fastening a post in a terminal clamp is suitable in particular for use in a battery sensor integrated in the terminal clamp, but is not limited thereto.