Abstract:
A flexible electrical connection ( 28 ) for electrically contacting a sensor ( 10 ) or a sensor module ( 12 ) includes at least one electrical conductor ( 14 ) extending in an axial length between a moveable component ( 18 ) and a stationary component ( 20 ). The at least one electrical conductor ( 14 ) is fixed to a sensor housing ( 22 ) via a rigid coupling ( 46 ) and is connected to a housing ( 16 ) of the sensor ( 10 ) or sensor module ( 12 ) via a movable, rotatable coupling ( 54 ). The at least one electrical conductor ( 14 ) includes first sections ( 32 ) and second sections ( 34 ), the second sections ( 34 ) including an injected coating. The first sections ( 32 ) have a higher deformation property than the second sections ( 34 ), and the first sections ( 32 ) do not include an injected coating, or they include an injected coating having the thickness of a film hinge. The first and second sections extend along an axial length of the at least one electrical conductor ( 14 ), The first sections ( 32 ) have a thickness ( 36 ) that is less than the thickness ( 38 ) of the second sections ( 34 ). The first and second sections define a hinge of the electrical conductor ( 14 ) by their lengths, such that in a bent position ( 42 ), a bend ( 48 ) of the at least one electrical conductor ( 14 ) of at least 90° is formed within one of said first sections ( 32 ).

Description:
CROSS-REFERENCE 
     The invention described and claimed hereinbelow is also described in PCT/EP2008/060554, filed on Aug. 12, 2008 and DE 10 2007 044 502.6, filed on Sep. 18, 2007. These Patent Applications, whose subject matter is incorporated herein by reference, provides the basis for a claim of priority of invention under 35U.S.C. 119 (a)-(d). 
     BACKGROUND OF THE INVENTION 
     DE 10 2005 002 813 B4 made known a control module that is used, in particular, in a motor vehicle transmission. The control module according to DE 10 2005 002 813 B4 includes a first housing part, on which an electronic circuitry part is located. The control module also includes a second housing part, and a carrier, on which a flexible conductor film is located. The flexible conductor film extends within a housing interior, which is formed between the first housing part and the second housing part, and is electrically connected to the circuitry part, and to electrical components that are also fastened to the carrier and are located outside of the housing interior. The second housing part is mounted on the flexible conductor film. The control module has a basically stacked design, in which the carrier is situated such that a first side lies on an inner side of the first housing part, on which the circuitry part is provided. The circuitry part is located in a recess in the carrier, and the flexible conductor film is located on the second side of the carrier, which faces away from the first housing part. 
     According to the current state of the art, sensors that are a component of a control module or a sensor module are either fixedly connected to the module, e.g., via heat caulking, or the sensors are electrically connected to the corresponding module via single cabling. The design of single electrical cabling means that the sensors are typically freely movable when not in the installed state, and during assembly. When single cabling is used, the cable may become damaged during the handling of the sensors, during installation, or during operation of the sensor system, the sensor, the sensor module or control module, and the electrical conductor. There is also a risk that the electrical conductor, which is designed as a single cable, will become twisted, and that the sensor will be installed in an incorrect position. In addition, the installation of sensors of this type takes a great deal of time relative to the other solutions. 
     In the case of sensors that are fixed in position, new components and additional test devices are required for every application. Furthermore, there is a disadvantage that the entire module must be manufactured at a very high level of precision since tolerance compensation may become necessary given that the entire module is stationary. In addition, packages of different sizes are required. 
     SUMMARY OF THE INVENTION 
     According to the present invention, a flexible electrical connection is provided, in which electrically conductive connections which are designed, e.g., as cables, litz wires, or flexfoils or the like, are protected against mechanical damage during assembly and operation. This makes it possible to use the flexible electrical connection, which is proposed according to the present invention, on sensors, plugs, or actuators in particular. During installation of the electrical connection, which is proposed according to the present invention, it may be deformed and assume an individualized installation position that is tailored to the requirements on installation space. By foregoing injected coatings or injected coatings of a plastic material, which enclose the electrical conductors, along various lengths as viewed in the direction of the extension of the conductor, it is possible to deform the flexible electrical connection in a specific manner, thereby ensuring that the flexible electrical connection has no friction points or sharp bends, during and after installation. 
     Furthermore, the flexible electrical connection, which is provided according to the present invention, makes it possible to realize different installation variants of a flexible electrical connection without the need to use additional parts. Compared to the fixed connections between a sensor, plug, or actuator and an associated sensor/control module, which have been used in the related art, a simplified design of a tolerance compensation may be provided via the flexible electrical connection according to the present invention. In addition, in the case of improper handling, e.g., if the control module, which is typically heavier than the sensor, is mounted on the sensor, the flexible electrical connection, which is provided according to the present invention, prevents, e.g., forces i.e., gravity in this case, from acting on the electrically conductive connections and damaging them to the extent that the electrical conductor fails during operation. 
     The specified stiffness of the flexible electrical connection, which is provided according to the present invention, whether they be used in individual cables, litz wires, or to enclose individual sections of a flexfoil relative to a simple cable connection which is known from the related art, prevents twisting from occurring during handling and is more reliable, thereby preventing, e.g., a sensor, plug, or actuator from being installed in the incorrect position. For a sensor, plug, or actuator that includes a flexible electrical connection to a control/sensor module, since it is possible to design the movability in a specific manner, e.g., compared to a sensor having single cabling, e.g., by using a different length and/or stiffness of individual injected-coating sections that enclose one or more electrical conductors, it is possible to define the positioning of the electrical connection during the installation process in a specific manner, thereby supporting an installation process that is faster, simpler, and considerably more reliable. In addition, via the flexible electrical connection that is provided according to the present invention, it is possible to greatly reduce the packaging volume as compared to a rigid design, i.e., a fixedly specified connection, e.g., between a sensor and a sensor module, since the sensor may be delivered in a position, e.g., in which it is folded against the housing of the sensor or the control module, thereby reducing the volume to be packaged to a decisive extent. 
     In a preferred embodiment, the flexible electrical connection is created using at least one injected plastic coating around the electrical conductor which may be designed, e.g., as a cable, a cable bundle, a litz wire, or a flexfoil. The flexible electrical connection, which is provided according to the present invention, may be designed, e.g., as an injected coating of the electrical conductor(s), in which individual sections of the injected coating are designed as a thin, hinge-type injected coating that is deformable, and other sections of the injected coating are formed of a thicker, firmer, and stiffer plastic injected coating. It is also possible to design individual cable sections of the cable bundle without injected coatings which, in this case, are a type of film hinge and have a deformation behavior or stiffness that differs from the deformation behavior or stiffness of cables, which include an injected coating, or foils or litz wire sections. In an advantageous embodiment of the idea on which the invention is based, sections of the injected coating, which are thin and hinge-like or do not include an injected coating, are situated in alternation with thicker sections of injected coating which include thicker walls and are therefore stiffer. The number of these alternating sections along the axial length of the electrical conductor, be it a cable, a cable bundle, a litz wire, a flexfoil or the like, is selected according to the particular application. The mechanical fastening of the electrical conductor via the electrical flexible connection, which is provided, to a sensor module or a control module may be realized, e.g., in the classical manner by supporting a clip, or via heat caulking, screws, rivets, or another type of non-positive or bonded connection. 
     The flexible electrical connection is preferably designed such that it extends through adjacent components without causing damage when installed in a housing. The electrical conductor is preferably bent at the point where the injected coating is less stiff, where the at least one electrical conductor is enclosed by a hinge-type injected-coating element having thinner walls, or where an injected coating of plastic material is not provided and an exposed section of the electrical conductor remains. The stiffness and/or a specific deformation path or a specific deformation of the electrical conductor, which is enclosed by at least one injected coating, may also be specified by specifying the axial length relative to the electrical conductor. 
     The flexible electrical connection, as provided according to the present invention, of a sensor, a plug, an actuator, or the like is preferably used on sensors, plugs, or actuators in which at least, e.g., one sensor should be electrically connected via at least one electrical conductor to a control module or a sensor module. The electrical conductor itself may be designed as a single cable, a cable strand, a twisted cable strand, a litz wire, or a flexfoil. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described in greater detail below with reference to the drawing, which shows: 
         FIG. 1  shows a sensor assembly according to the related art, which includes a rigid connection between the sensor element and the sensor module, 
         FIG. 2  shows an embodiment of the electrical connection, which is provided according to the present invention, and which includes a flexible sensor system that is in a bent position, 
         FIG. 3  shows the flexible electrical connection, which is presented in  FIG. 2 , in an extended position in an installation position, 
         FIG. 4  shows the side view of the flexible electrical contacting, which is provided according to the present invention, in a bent position, and 
         FIG. 5  shows the side view of the electrical connection, which is provided according to the present invention, in a further installation position. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The depiction presented in  FIG. 1  shows a rigid electrical connection that is known from the related art. 
     As shown in  FIG. 1 , a sensor  10  is electrically connected to a sensor module  12  via an electrical conductor  14 . In the configuration shown in  FIG. 1 , electrical conductor  14  is designed as a rigid electrical connection  28 . Sensor  10  is located in a sensor housing  22 . A movable component  18 , which, in the illustration shown in  FIG. 1 , is located at a first distance  24  away from the circumference of a stationary component  20 , is located above rigid electrical connection  28 . Sensor module  12  is located, e.g., in a vehicle transmission. Rigid electrical connection  28  extends underneath movable component  18  and above stationary component  20 , and is connected via a rigid coupling to a housing  16  of sensor module  12 . 
     The illustration presented in  FIG. 2  is a perspective view of an electrical connection that is provided according to the present invention. 
     As shown in  FIG. 2 , housing  16  of sensor module  12  and sensor  10 , which is accommodated in sensor housing  22 , are electrically interconnected via electrical conductor  14 . According to the illustration shown in  FIG. 2 , electrical conductor  14  may be designed, e.g., as a flexfoil, a litz wire, or a cable or a cable bundle. 
     As shown in the perspective view presented in  FIG. 2 , electrical conductor  14  includes a first section  32 , and a second section  34  which is adjacent thereto and includes an injected coating. First sections  32  and second sections  34  are situated in alternation along the axial length of electrical conductor  14 . First sections  32  may be designed without injected coatings, or they may be provided with a thin, film hinge-type injected coating which is thinner than the injected coating of second sections  34 . In the descriptions that follow, the expression “film hinge-type” refers to a thickness of a film hinge that is made of plastic material. 
     First sections  32  differ from a subsequent, second section  34  either in that they lack an injected coating, or in terms of the thickness of the plastic material that at least partially encloses electrical conductor  14 , be it a cable, a cable bundle, a flexfoil, or a litz wire, and that influences the bending resistance of electrical conductor  14 . 
     In bent position  42 , which is shown in  FIG. 2 , electrical conductor  14  is bent in section  32  that does not include an injected coating. The illustration presented in  FIG. 2  also indicates that connections of electrical conductor  14  to sensor housing  22  of sensor  10 , and to housing  16  of sensor module  12  are not depicted here. As indicated in the illustration presented in  FIG. 2 , a first section  32 , which performs a film-hinge function, is followed by a second section  34  which is followed by a first section  32 , and so forth, on electrical conductor  14 . The wall thickness of the injected coating of second section  34  is advantageously selected such that, due to its greater stiffness, bend  48  forms in the region of first section  32 . A specific deformation may be attained via the design of the injected coating on second sections  34  and the design of second sections  32 , which do not include an injected coating, or in a thin, film hinge-type injected coating in terms of its axial length and in terms of the thickness of the injected coating relative to the at least one electrical conductor  14 , thereby making it possible for electrical conductor  14  to attain its greatest deformation at the desired point, as indicated in  FIG. 2 . 
     The depiction presented in  FIG. 3  shows the flexible electrical connection, which is provided according to the present invention, in another installation position. 
     As shown in  FIG. 3 , the at least one electrical conductor  14 , be it a single cable, a cable bundle, litz wires, or flexfoils, is positioned in an installation position that is indicated by reference numeral  44 . Compared to the illustration presented in  FIG. 2 , housing  22  of sensor  10  is located in another position which is further away from housing  16  of sensor module  12 . As shown in  FIG. 3 , the at least one electrical conductor  14  assumes extended position  44  which is indicated, e.g., by a second bend  56  in installation position  44 . In installation position  44  depicted in  FIG. 3 , the at least one electrical conductor  14  is not bent to the same extent within first section  32  as it is in bent position  42 ; instead, it is merely bent by a smaller angle in installation position  44 , as shown in  FIG. 3 . 
     In a comparison of  FIGS. 2 and 3 , it becomes clear that flexible electrical connection  28  is deformed, in the installation positions shown, to a different extent—in this case, they are bent—and electrically connects sensor  10  to sensor module  12  in the installation positions shown  FIGS. 2 and 3 . A specific deformation may be imparted to the at least one electrical conductor  14  in various installation positions  42 ,  44  due to the alternating sequence of first sections  32 , which do not include an injected coating, or which include a thin, film hinge-type injected coating, and second sections  34  which include an injected coating. Via the appropriate design of the axial length of the at least one electrical conductor  14  and the appropriate positioning of first sections  32  and second sections  34 , which include an injected coating, it is possible to prevent contact, and resultant damage, of the at least one electrical conductor  14  with other components, e.g., a movable component  18  (see  FIG. 4 ). 
     The illustration shown in  FIG. 4  shows the bent position of the flexible electrical connection that is depicted in  FIG. 2 . 
     As shown in  FIG. 4 , the at least one electrical conductor  14  is located in the bent installation position that is indicated via reference numeral  42 . Underneath sensor housing  22 , the at least one electrical conductor  14  is connected at a coupling  46  to sensor housing  22 . Coupling  46  may also be designed, e.g., as an injected coating of plastic material, in order to prevent excessive bending of electrical conductor(s)  14  directly below sensor housing  22  of sensor  10 . A first section  32 , which is designed to have a first thickness  36 , extends below coupling  46 . Thickness  36  of first section  32  is given by the thickness of first section  32 , which does not include an injected coating, or by the thickness of first section  32  which includes a thin, film hinge-type injected coating. First section  32  may extend in different lengths along the at least one electrical conductor  14 , depending on the desired extent of deformation of flexible electrical connection  28 , and depending on the amount of installation space that is available. By selecting the length of first sections  32  and the length of second sections  34 , which include an injected coating, the deformability of electrical conductor  14  may be specified in a defined manner, thereby making it possible to place it in a certain position, e.g., during installation, in which, e.g., sensor housing  22 , and sensor  10  accommodated therein, permanently remains. 
     A second section  34 , which includes an injected coating and encloses the at least one electrical conductor  14 , extends below first section  32  at rigid or rotatable coupling  46  on sensor housing  22 . As indicated in a comparison of thickness  36  of first section  32  and thickness  38  of second section  34 , as shown in  FIG. 4 , second section  34  includes a first injected coating that has a second thickness  38  that is greater than thickness  36  of first section  32 . As a result, due to the greater material thickness in the region of second section  34 , which includes an injected coating and is labelled with reference numeral  38 , it is difficult to deform flexible electrical connection  28 , due to the greater stiffness. In contrast, as previously indicated in  FIG. 2 , first bend  48  is predominant in further first section  32 , which includes a film hinge-type injected coating or does not include an injected coating, and which follows second section  45 , which includes an injected coating. As a result, adjacent second section  34 , which includes an injected coating, is in a nearly horizontal position and extends to a coupling  54 , which is rotatable in this embodiment, on the outside of housing  16  of sensor module  12 . As furthermore shown in  FIG. 4 , first distance  24 , which was indicated previously in  FIG. 1 , exists between component  18 , which is located in a first installation position, and a circumference  60  of stationary component  20 .  FIG. 4  shows a deformation of the at least one electrical conductor  14 , which is defined in an alternating sequence by first sections  32  and second sections  34 , which include an injected coating, in the region in which first sections  32 , which have lesser thickness  36 , are located. Depending on the length of first sections  32  and/or second sections  34 , which include an injected coating a specified deflection path of the at least one electrical conductor  14  may be specified, as viewed in the axial direction of the at least one electrical conductor  14 . Electrical conductor  14  assumes first installation position (bent position)  42 , which is shown, e.g., in  FIG. 4 , and is located, without contact, between circumference  60  of stationary component  20  and the underside of component  18 . While coupling  46  of the at least one electrical conductor  14  to sensor housing  22  of the at least one sensor  10  is considered to be approximately rigid, the other coupling, i.e., rotatable coupling  54 , is rotatably connected to housing  16  of sensor module  12 , thereby making it easier to adjust the at least one electrical conductor  14  upon installation. As an alternative, coupling  54  may also be designed as a rigid coupling. Component  18  may be a stationary component, or a component that is movable in vertical direction  40  inside a housing, e.g., relative to flexible electrical connection  28 . 
     The illustration presented in  FIG. 5  shows a further installation position of the flexible electrical connection. 
     As shown in  FIG. 5 , flexible electrical connection  28 , which is provided according to the present invention, connects the at least one sensor  10 , which is accommodated in sensor housing  22 , to housing  16  of sensor module  12 . As shown in  FIG. 5 , sensor housing  22  and component  18  assume an installation position that is slid upward vertically, as shown in  FIG. 5 , thereby resulting in a different installation position  44 , in which electrical connection  28 , which is provided according to the present invention, extends. As shown in  FIG. 5 , a first section  32  extends via a first axial length  50  below rigid coupling  46  of the at least one electrical conductor  14  on the underside of housing  22 . As likewise shown in  FIG. 5 , the thickness of first section  32 , which does not include an injected coating, or includes an injected coating having a minimal thickness  36 , is less than thickness  38  of second section  34 , which includes an injected coating, and which adjoins first section  32  in the axial direction of the at least one electrical conductor  14 . As a result, first sections  32  have a greater deformability, i.e., they are more easily deflected than second sections  34 , which include an injected coating. Via thicknesses  36 ,  38  of first sections  32  and second sections  34 , which include an injected coating, and lengths  50 ,  52  of sections  32 ,  34 , respectively, it is possible to impart a defined deformation to the at least one electrical conductor  14 . As shown, e.g., in  FIG. 5 , electrical conductor  14  then assumes an installation position  44  between rigid coupling  46  on sensor housing  22  and rotatable—or rigid, as an alternative—coupling  54  on housing  16  of sensor module  12 . 
     In the illustrations shown in  FIGS. 2 through 5 , first sections  32  and second sections  34 , which include an injected coating, are installed along the axial length of the at least one electrical conductor  14  in an alternating sequence. As an alternative to designing first sections  32  or second sections  34 , which include an injected coating, to have different lengths  50 ,  52  or different thicknesses  36 ,  38 , a defined deformation may also be imparted to the at least one electrical conductor  14  via the flexible electrical connection  28  by applying a section of plastic material, e.g., in one or more layers, on the individual longitudinal sides of the at least one electrical conductor  14 , and by foregoing it entirely on the side opposite the single or multiple-layered plastic section. As a result, depending on the application, a defined deformability may be imparted to the at least one electrical conductor  14 , thereby considerably simplifying the installation of the, e.g., at least one sensor  10  or sensor housing  22 , e.g., on a vehicle transmission, thereby enabling assembly to be drastically shortened on a permanent basis. 
     Using flexible electrical connection  28 , which is provided according to the present invention and is formed on the at least one electrical conductor  14 , it is possible to create various applications of flexible electrical connection  28  by installing first sections  32  and second sections  34 , which include an injected coating, in an alternating sequence. As a result, it is possible to avoid creating an unnecessary wide variety of parts, thereby enabling costs to be reduced considerably in large series production.