Abstract:
The invention relates to an electric charging device, to a charging system, to a method for charging a battery of a vehicle, and to an electric connection device of a vehicle for charging a battery of the vehicle. The electric charging device comprises the following: a lifting device ( 11 ) to which a charging head ( 12 ) is coupled, wherein the charging head ( 12 ) has a first plurality of first electric contacts ( 14 ) on a first surface ( 13 ) of the charging head ( 12 ), at least some of said contacts being connectable to an energy source in order to charge the battery; and an actuator ( 16 ) by means of which the lifting device ( 11 ) can be actuated such that the charging head ( 12 ) can be at least partly moved in a first direction (R 1 ) that is substantially perpendicular to the first surface ( 13 ). The lifting device ( 11 ) is further designed such that the charging head ( 12 ) can be moved in a second direction (R 2 ) along a stop surface (U, P) by continuing to actuate the lifting device ( 11 ) by means of the actuator ( 16 ) upon striking the stop surface (U, P) in the first direction (R 1 ).

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to an electric charging device for charging a battery of a vehicle, to an electric connection device of a vehicle for charging a battery of the vehicle, to a system for charging a battery of a vehicle and to a method for charging a battery of a vehicle. 
         [0002]    Hybrid and electric vehicles at least partially resort to batteries in order to supply their drive train with energy. If the battery of a vehicle is empty, it can be recharged at a charging station by means of a charging device. 
         [0003]    The positioning of the vehicle with respect to the charging device as automatically as possible and the connection of the charging device to the vehicle as automatically as possible for the purpose of charging the battery comprise some technical challenges. Automated conductive charging systems require precise guidance of a charging head, for example a connector, of the charging device to a receiving head, for example a connector socket, of a connection device on a vehicle. 
         [0004]    On account of their different designs, vehicles often have different positions for the receiving head. In addition, no uniformity is ensured as a result of a receiving head being arranged on the underbody of the vehicle since vehicles have different heights and the underbody of vehicles is therefore at a different height from a base on which the vehicle stands. Vehicles are usually positioned precisely and sometimes also obliquely by their drivers, only apart from an error of approximately +−10 cm. The task of guiding the charging head to the receiving head can be handled, for example, by technically complex robots, for instance having target acquisition, measuring and image processing systems. 
         [0005]    U.S. Pat. No. 2,011,066 515 A1 describes an automatic connector station for charging electric and hybrid vehicles. In this case, the vehicle is positioned over a trapdoor. A positioning system detects the position of a connector socket on the vehicle. A connector can be vertically extended and retracted for the purpose of being plugged into and unplugged from the connector socket and is connected to an energy source. On the basis of the detected position of the connector socket on the vehicle, the connector is horizontally displaceable in two dimensions, with the result that the connector enters the connector socket when vertically extended. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention discloses a charging device, a connection device, a charging system and a method for charging a battery of a vehicle. 
         [0007]    Accordingly, an electric charging device for charging a battery of a vehicle is provided, having: a lifting device, to which a charging head is coupled; the charging head having a first plurality of first electric contacts at or on a first surface of the charging head, at least some of which contacts can be connected to an energy source for the purpose of charging the battery; and an actuator which can be used to actuate the lifting device in such a manner that the charging head can be moved at least partially in a first direction which is substantially perpendicular to the first surface; the lifting device also being designed in such a manner that, upon striking a stop surface in the first direction, the charging head can be moved in a second direction along the stop surface by means of continued actuation of the lifting device by the actuator. 
         [0008]    An electric connection device of a vehicle for charging a battery of the vehicle is also provided, having: a receiving head which has a second plurality of second electric contacts at or on a second surface of the connection device; a guide device for receiving a charging head which is placed against the connection device and moves substantially parallel to the second surface and for guiding the moving charging head and the receiving head into a predetermined positional relationship with respect to one another; in which case, if the charging head and the receiving head are substantially in the predetermined positional relationship with respect to one another, the battery of the vehicle can be charged via the second electric contacts. 
         [0009]    A charging system for charging a battery of a vehicle is also provided, having: 
         [0010]    an electric charging device according to the invention which is installed outside the vehicle; and an electric connection device according to the invention which is formed on the vehicle; the charging head of the charging device being designed in such a manner that it can be inserted into the guide device of the connection device, and the first electric contacts being able to be at least partially placed against the second electric contacts for the purpose of charging the battery. 
         [0011]    A method for charging a battery of a vehicle is also provided, comprising: 
         [0012]    actuating a lifting device by means of an actuator in such a manner that a charging head connected to the lifting device moves at least partially in a first direction which is substantially perpendicular to a first surface of the charging head, a first plurality of first electric contacts being formed at the first surface, which contacts are at least partially connected to an energy source; and also in such a manner that, if the charging head strikes a stop surface in the first direction, the charging head moves in a second direction along the stop surface; guiding the charging head moving along the stop surface into a predefined charging position with respect to a receiving head having second electric contacts by means of a guide device; and charging the battery of the vehicle from the energy source via the first and second electric contacts. 
         [0013]    The knowledge on which the present invention is based is that a system for charging a battery of a vehicle can be provided with technically little effort, which system can be actuated using an actuator, in particular using precisely a single actuator, in such a manner that, in the case of a position of the vehicle inside a predetermined area around a charging device, a charging head of the charging device is automatically guided to a receiving head on the vehicle. The vehicle can be guided into the predetermined area by means of a navigation or parking assistance system, for example. 
         [0014]    The actuator of the charging device according to the invention causes the charging head fastened to the lifting device to first of all be raised to the underbody of the vehicle and to then be automatically moved along the underbody in a manner pressed against the latter. The height of the underbody of the vehicle must neither be known nor must assume a particular value. Rather, the charging device can be flexibly used in a multiplicity of vehicles without any adaptation. It may suffice if the height of the underbody assumes values in a particular range of values. 
         [0015]    An individual actuator advantageously causes a linear movement of a part of the lifting device, in particular a slide, which in turn causes the remaining movement of the charging device, as described above. As a result, the charging device is technically particularly simple, robust and reliable. 
         [0016]    Charging on the underside of the vehicle has the advantage that disruptive interaction with the charging system or with the charging device is made difficult. Furthermore, the design freedom of the vehicle manufacturers is not restricted by this solution. 
         [0017]    According to the invention, a connection device is formed on the vehicle in such a manner that the moving charging head which strikes it is guided even in the case of a certain lateral offset with respect to the predetermined charging position of the charging head with respect to the receiving head. This is carried out in a purely mechanical manner without electronic elements on the connection device side. Only the single actuator is preferably still used on the charging device side. 
         [0018]    Advantageous embodiments and developments emerge from the subclaims and from the description with reference to the figures. 
         [0019]    According to one preferred development of the electric charging device, the first electric contacts are in the form of lamellae which are parallel to one another and are perpendicular to the first surface. As a result, the first contacts can be contact-connected to corresponding contacts of a connection device in a particularly stable manner. 
         [0020]    According to another preferred development, at least one of the lamellae has a different length in comparison with the remaining lamellae. The contact-connection can be carried out by inserting the lamellae into guide slots having contacts along the lamellae. As a result of the different length of the at least one lamella, this first contact can be contact-connected earlier, later, for a longer or shorter time than the contact-connection of the remaining first contacts. 
         [0021]    According to another preferred development, at least one of the lamellae is arranged in a manner offset from the remaining lamellae in a direction along the lamellae. As a result of the different length of the at least one lamella, this first contact can be contact-connected earlier or later than the contact-connection of the remaining first contacts. 
         [0022]    According to another preferred development, the charging head is coupled to the lifting device via a first arm; a first end of the first arm being coupled to the charging head via a first spring; and a second end of the first arm being coupled to the remaining lifting device via a second spring. As a result, the charging head can be pressed against the stop surface of the vehicle by means of a restoring force and, at the same time, can be moved along the stop surface. At the same time, the situation is avoided in which the charging head can be pressed too strongly against the stop surface or cannot be lifted up to the stop surface on account of its weight. 
         [0023]    According to another preferred development, the actuator and the lifting device are formed in such a manner that the lifting device can be actuated for the purpose of moving the charging head by virtue of the actuator causing a linear movement of a slide of the lifting device. Linear movements are particularly simple and easy to control. The technical elements required for this purpose are simple, technically not very complicated, robust and reliable. 
         [0024]    According to one preferred development of the connection device according to the invention, the second electric contacts are arranged parallel to one another and at a distance from one another in a direction parallel to the second surface. As a result, charging heads having first contacts arranged parallel to one another can be used to contact-connect the connection device. 
         [0025]    According to another preferred development, the receiving head is movable with respect to the vehicle and is connected to the vehicle via at least one spring. The at least one spring can exert a restoring force in the event of deflections of the receiving head from a position of rest. As a result, the connection device can be automatically displaced in such a manner that the charging head and the receiving head can be brought into the predefined positional relationship with respect to one another, that is to say the first and second contacts can make contact with one another. 
         [0026]    The above configurations and developments can be combined with one another in any desired manner if useful. Further possible configurations, developments and implementations of the invention also comprise combinations (not explicitly mentioned) of features of the invention described above or below with respect to the exemplary embodiments. In particular, a person skilled in the art will also add individual aspects to the respective basic form of the present invention as improvements or additions. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]    The present invention is explained in more detail below using the exemplary embodiments which are illustrated in the schematic figures of the drawings, in which: 
           [0028]      FIG. 1A  shows a schematic side view of an electric charging device for charging a battery of a vehicle according to a first embodiment of a first aspect of the present invention in a first state; 
           [0029]      FIG. 1B  shows a schematic side view of an electric charging device for charging a battery of a vehicle according to the first embodiment of the first aspect of the present invention in a second state; 
           [0030]      FIG. 2  shows an oblique plan view of the charging device according to the first embodiment of the first aspect of the present invention; 
           [0031]      FIG. 3  shows a detailed view of the charging head of the charging device according to the first embodiment of the first aspect of the present invention; 
           [0032]      FIG. 4A  shows a schematic plan view from below of an electric connection device of a vehicle for charging a battery of the vehicle according to a first embodiment of a second aspect of the present invention; 
           [0033]      FIG. 4B  shows a schematic plan view from above of the electric connection device of a vehicle for charging a battery of the vehicle according to the first embodiment of the second aspect of the present invention; 
           [0034]      FIG. 4C  shows a schematic plan view from the front of an electric connection device of a vehicle for charging a battery of the vehicle according to the first embodiment of the second aspect of the present invention; 
           [0035]      FIG. 5A  shows a schematic detailed view from above of the receiving head of the connection device according to the first embodiment of the second aspect of the present invention; 
           [0036]      FIG. 5B  shows a schematic detailed view from the front of the receiving head of the connection device according to the first embodiment of the second aspect of the present invention; 
           [0037]      FIG. 6  shows a schematic flowchart of a method according to the invention according to a third aspect of the present invention; 
           [0038]      FIG. 7  shows an electric charging device of a vehicle for charging a battery of the vehicle according to a second embodiment of the first aspect of the present invention; and 
           [0039]      FIG. 8  shows an electric connection device of a vehicle for charging a battery of the vehicle according to a second embodiment of the second aspect of the present invention. 
       
    
    
       [0040]    In all figures, identical or functionally identical elements and devices are provided with the same reference symbols, unless stated otherwise. 
       DETAILED DESCRIPTION 
       [0041]      FIG. 1A  shows a schematic side view of an electric charging device  10  for charging a battery of a vehicle according to a first embodiment of a first aspect of the present invention in a first state. 
         [0042]    A charging head  12  has a first plurality of electric contacts  14  at a first surface  13  of the charging head  12 . The electric contacts  14  are in the form of lamellae which are parallel to one another and are perpendicular to the first surface  13 . When seen from the side, the lamellae are trapezoidal strips, the longer of the two parallel sides of the trapeze respectively being connected to the first surface  13 . The charging device  10  is set up on a base G, for example the ground, a floor, a vehicle floor or another suitable flat surface. It is advantageous to fit the charging device  10  on a surface which is lower than the ground and is parallel to the latter or in a recess, for instance in the ground of a parking lot. If the charging device  10  is formed in a compartment or a hollow in a bump, which is also advantageous, the charging device  10  can be protected from rainwater, for example, when puddles form. The first surface  13  is substantially parallel to the base G and points away from the latter. If set up on the ground, the first surface  13  therefore points upward. 
         [0043]    The charging head  12  is coupled to a lifting device  11  which can be actuated by means of an actuator  16  in order to move the charging head  12 . The charging head  12  is rotatably coupled, via a first arm  21  as part of the lifting device  11 , to the rest of the lifting device  11 . The charging head  12  is coupled to a first end of the first arm  21  via a first rotating joint  41  having a first torsion spring  31  in such a manner that the axis of the first torsion spring  31  is parallel to the first surface  13 . The first rotating joint  41  is formed on a side surface  15  of the charging head  12  which faces away from the first surface  13 . The charging head  12  can be tilted about the axis of the first torsion spring in a first angular range by means of the first torsion spring  31 , the first surface  13  being parallel to the base G in the position of rest. The first angular range is between −90° and +90°, advantageously between −45° and +45°, in particular between −30° and +30°. The first arm  21  is rotatably coupled, at a second end of the first arm  21 , to the rest of the lifting device  11  by means of a second torsion spring  32  on a second joint  42 . The axis of rotation of the second rotating joint  42  is parallel to the axis of rotation of the first rotating joint  41 . 
         [0044]    According to the first embodiment, the actuator  16  is in the form of an electric motor for rotating a shaft W. The shaft W is coherently connected to a guide  18  of the lifting device  11  which is in the form of a thin full or hollow cylinder, sometimes with a screw thread on the outer casing. A slide  20  of the lifting device  11  is mounted on the guide  18  by means of an inner screw thread which engages in the screw thread of the guide  18 . 
         [0045]    Two second arms  22  of the lifting device  11  are rotatably mounted, at respective first ends of the second arms  22 , on the slide  20  via two third rotating joints  43 . The axes of rotation of the third rotating joints  43  are collinear and parallel to the axes of rotation of the first and second rotating joints  41 ,  42 . At respective second ends of the second arms  22 , the second arms  22  are rotatably coupled to a third arm  23  of the lifting device  11  via at least one fourth rotating joint  44 . The third arm  23  is rotatably coupled, at a first end of the third arm  23 , to the first arm  21  via the second rotating joint  42  having the second torsion spring  32 . The fourth rotating joint  44  is arranged on the third arm  23  between the first end of the third arm  23  and a second end of the third arm. The fourth rotating joint  44  is preferably closer to the first end of the third arm  23  than to the center point between the first and second ends of the third arm  23  and also closer to the first end than to the second end of the third arm  23 . The axis of rotation of the fourth rotating joint  44  is parallel to the axes of rotation of the first, second and third rotating joints  41 ,  42 ,  43 . 
         [0046]    The third arm  23  is rotatably coupled, at the second end of the third arm  23 , to a first bearing block  17  of the lifting device  11  via a fifth rotating joint  45 . The guide  18  is rotatably mounted, at a first end of the guide  18 , in the first bearing block  17 , the guide not having a screw thread on the mounted section of its outer casing. The bearing block  17  is permanently connected to the base G. The axis of rotation of the fifth rotating joint  45  is parallel to the axes of rotation of the first, second, third and fourth rotating joints  41 ,  42 ,  43 ,  44 . The axis of rotation DA of the guide  18 —and therefore simultaneously of the shaft W—is in a conceivable plane which is perpendicular to the axes of rotation of all rotating joints  41 ,  42 ,  43 ,  44 ,  45 . 
         [0047]    As a result of the slide  20  being connected via the third joint  43 , the second arm  22 , the fourth joint  44 , the third arm  23 , the fifth joint  45  and the bearing block  17 , the slide  20  cannot be rotated around the guide  18  at its screw thread, even during rotation D of the shaft W and the guide  18  by the actuator  16 , but rather instead carries out a linear movement LB during the rotation D. The linear movement LB can take place between the first bearing block  17  and a second bearing block  19 . The slide  20  can move away from the first bearing block  17  at most to an extent allowed by the combined length of the second and third arms  22 ,  23 . The guide  18  is rotatably mounted, at a second end of the guide  18 , on the second bearing block  19  and is connected to the shaft W. 
         [0048]    The first electric contacts  14  are at least partially connected to an energy source E via at least one cable. At least one of the first electric contacts  14  can also be connected to a first control device of the charging device  10  via a further cable. This first contact  14  can therefore be used to transmit control and/or data signals to the vehicle to be charged. One or more of the cables can run in the interior of the first arm  21  in the form of a hollow profile and in the interior of the third arm  23  in the form of a hollow profile and can be connected to the energy source arranged under the base G via the interior of the bearing block  17 . One or more cables can also be routed along the arms  21  and/or  23  on the outside. In this case, the cable can advantageously be fixed only at two points on the arms  21 ,  23 , with the result that it is loose enough to allow bending and/or stretching movements of the arms relative to one another. The energy source E can simultaneously provide the energy for the actuator  16 , here an electric torque motor. 
         [0049]      FIG. 1A  shows a state in which the slide  20  has been linearly moved from the second bearing block  19  in the direction of the first bearing block  17  by the rotation D of the shaft W as actuation of the lifting device  11 . The closer the slide  20  approaches the first bearing block  17 , the more the second arm  22  lifts from a position parallel to the guide  18 . That is to say, an angle α between the second arm  22  as the first limb and the axis of rotation DA of the guide  18  as the second limb with the third rotating joints  43  as the apex increases from substantially 0° for a maximum distance between the slide  20  and the first bearing block  17  to a maximum value of the angle α for a minimum distance between the slide  20  and the first bearing block  17 . The third arm  23  is also raised as a result. An angle β between the base G as the first limb and the third arm  23  as the second limb and/or an angle γ between the guide  18  as the first limb and the third arm  23  as the second limb may also increase from 0°, for example, to more than 90° in this case. 
         [0050]    Since the third arm  23  is coupled to the first arm  21  via the second torsion spring  32 , the first arm  21  is also moved with the charging head  12  as a result of the rotation D. The spring hardness of the second torsion spring  32  is set in this case with respect to the weight of the first arm  21  and of the charging head  12  in such a manner that the first arm  21  initially lifts with the third arm  23  substantially like an extension of the third arm. The first arm  21  is longer than the second arm  23 , for example three times as long. The charging head  12  at the first end of the first arm  21  therefore initially moves, as a result of the rotation D, on a circular path with a small deflection with respect to the base, that is to say partially, preferably mainly in a first direction R 1  which is perpendicular to the first surface  13 . If the base G is the ground, the charging head  12  therefore moves mainly upward. 
         [0051]      FIG. 1B  shows a schematic side view of an electric charging device  10  for charging a battery of a vehicle according to the first aspect of the present invention in a second state. 
         [0052]    When the charging device  10  is used according to the invention, a vehicle F with an underbody U is positioned at an initially unknown height above the charging device  10 . If the charging head  12  strikes the underbody U as the stop surface during its movement, as described with reference to  FIG. 1A , the movement is inhibited in the first direction R 1 . On account of the further movement of the third arm  23 , the charging head  12  is then moved, in a manner pressed against the underbody U, along a second direction R 2  which is arranged substantially parallel to the first surface  13  and perpendicular to the first direction R 1 . 
         [0053]      FIG. 2  shows an oblique plan view of the charging device  10  according to the first aspect of the present invention. 
         [0054]      FIG. 3  shows a detailed view of the charging head  12  of the charging device  10  according to the first aspect of the present invention. 
         [0055]    A first plurality of first electric contacts  14  are formed at the first surface  13  of the charging head  12  having the width B and the length L. The first contacts  14  are in the form of lamellae which are arranged parallel to one another and parallel to the length L of the charging head  12  and are perpendicular to the first surface  13 . According to the invention, the charging head  12  is guided to a connection device  110  along the second direction R 2  parallel to the lamellae and parallel to the length L. 
         [0056]    Some or all of the lamellae of the first contacts  14  may have different lengths. Some or all of the lamellae may also be arranged in a manner offset from one another along the second direction R 2 . This may result in temporally offset contact-connection and/or contact-disconnection of the different first electric contacts  14  when the charging head  12  is being guided to the connection device  110 . For example, an electric first contact  14  which is connected to a first control device of the charging device  10  can first of all be contact-connected to a second electric contact of the connection device  110  which is connected to a second control device of the connection device  110 . If an abort signal is output from one of the control devices in this case, for example, the actuator  16 , for instance, can be controlled by the first control device to reverse the direction of rotation D. 
         [0057]    The charging device can be flexibly designed to charge with direct current or alternating current. Information relating to whether charging is intended to be carried out using direct current or alternating current or another type of current can be transmitted, for instance, during the first contact-connection of a first contact  14  in terms of time. 
         [0058]    According to  FIG. 3 , five first contacts  14  are formed on the charging head  12 , that is to say the first plurality is five. Alternatively, however, the first plurality may also be seven or more, for example. In this case, five and seven contacts may comply with current standards for single-phase and three-phase charging with direct current. The plurality may also be an even number and may be four or six, for example. One or more of the first contacts  14  may be in the form of a ground line, a high-voltage line, a low-voltage line etc. for the purpose of transmitting data and/or control signals. 
         [0059]      FIG. 4A  shows a schematic plan view from below of an electric connection device  110  of a vehicle for charging a battery of the vehicle according to a first embodiment of the second aspect of the present invention. The connection device  110  according to the first embodiment of the second aspect and the charging device  10  according to the first embodiment of the first aspect may together constitute an embodiment of the charging system according to the invention. 
         [0060]    The connection device  110  is arranged on the underbody U of the vehicle. A plate P of the connection device  110  is mounted on or around two rods  102  arranged parallel to one another in such a manner that it is displaceable along the rods  102 . The connection device  110  is connected to the rest of the vehicle via the rods  102 . The rods  102  may be hollow on the inside. Cables can run inside the rods  102  between the vehicle, in particular a battery of the vehicle, and the connection device and can electrically couple them to one another. The displaceability of the plate P on the rods  102  is reduced by at least one spring  104  arranged parallel to the rods  102 . According to  FIG. 4 , four springs  104  exert a restoring force in such a manner that the plate P is in the center of the rods  102  and, at the same time, is on the longitudinal axis of the vehicle in the position of rest. Restoring force is used to mean a spring force which counteracts a deflection of the plate P and therefore also of the receiving head  102  from their respective position of rest. 
         [0061]    According to the described embodiment of the second aspect, a receiving head  112  is formed on the plate P of the connection device  110  and has a second plurality of second electric contacts  114  on a second surface  113  of the plate P. The second electric contacts  114  are at least partially electrically connected to the battery of the vehicle via the cables inside the rods  102 . One or more second contacts  114  may also be connected to a control device of the vehicle which can be used to control the charging of the battery. 
         [0062]    The second surface  113  faces away from the vehicle. The receiving head  112  is surrounded by a guide device  118  on the second surface  113  of the plate P, which guide device is used to guide a charging head  12  of a charging device  10  according to the invention into a predetermined charging position with respect to the receiving head  112 . According to the embodiment of the second aspect of the present invention, as described with reference to  FIG. 5 , the guide device  118  can be described as “symmetrically hourglass-shaped in three stages” in plan view, the receiving head  112  being at the narrowest point in the center of the hourglass. The guide device  118  therefore forms a channel K which tapers in a V-shaped or funnel-shaped manner in the direction of the receiving head  112  at both ends of the channel until the width of the channel K substantially corresponds to the width of the receiving head  112 . The width of the receiving head  112  is substantially equal to the width B of the charging head  12  according to the invention, with the result that the charging head  12  of the charging device  10  according to the invention can run completely through the channel K. The receiving head  112  is formed in a section K′ of the channel K with a constant width. 
         [0063]    The charging head  12  of the charging device  10  will usually not move toward the receiving head  112  exactly in a desired direction R 2 ′ if it moves along the second direction R 2  in a manner pressed against the underbody of the vehicle, as described with reference to  FIG. 1B . The desired direction R 2 ′ is along a longitudinal axis of the channel K, in particular along an axial symmetry axis as the longitudinal axis. The second direction R 2  is fixed by the arms  21  and  23 . 
         [0064]    If the charging head  12  strikes the V-shaped interior of the channel of the guide device  118  during its movement and if it presses against a channel inner wall  119  in the second direction R 2 , a force may be produced in a third or fourth direction R 3 , R 4  perpendicular to the desired direction R 2 ′ and parallel to the second surface  113 . As a result, the plate P of the connection device  110  can be accordingly displaced along the rods  102  in the third or fourth direction R 3 , R 4  until the charging head  12  enters the section K′ with a constant width of the channel K. Displacement in the third or fourth direction R 3 , R 4  then no longer takes place and the charging head  12  strikes the receiving head  112  precisely in a predetermined orientation. According to the invention, the charging head  12  is pressed against the underbody U of the vehicle, more precisely against the plate P of the connection device  110 . 
         [0065]    If the charging head  12  strikes the guide device  118  during its movement in the second direction R 2  in such a manner that a non-vanishing angle exists between the second direction R 2  and the desired direction R 2 ′, a torque—additionally or alternatively to the forces described in the preceding paragraph—can also be exerted on the plate P. As shown in the following  FIGS. 4B and 4C , the plate is suspended from the rods  102  via a rotating joint  132 , with the result that the torque can effect an advantageous orientation of the receiving head  112 . For example, the desired direction R 2 ′ defined with respect to the receiving head  112  can be matched to the second direction R 2 . During a rotational movement of the plate P caused by the charging head  12 , the springs  104  are accordingly stretched or compressed. In a position of rest, the springs  104  keep the channel K oriented in the direction of the desired direction R 2 ′ which is advantageously the forward direction of travel of the vehicle. 
         [0066]      FIG. 4B  shows a schematic plan view from above of the electric connection device  110  of a vehicle for charging a battery of the vehicle according to the first embodiment of the second aspect of the present invention. 
         [0067]    As shown in  FIG. 4B , the plate P is connected, on a rear side  133  of the plate P which faces away from the surface  113 , to a yoke  130  via a rotating joint  132 . The rotating joint  132  is advantageously arranged above a center of gravity of the plate P. The two rods  102  are guided through the yoke  130  in a manner parallel to one another and parallel to the plate P in such a manner that the yoke  130  which is permanently connected to the plate P can move along the rods  102 . As a result, the plate P is displaceable along the rods  102 , as described above. The plate P is also rotatable, by means of the rotating joint  132 , around an axis of rotation perpendicular to the second surface  113  and perpendicular to the rear side  133  of the plate P in order to facilitate entry of the charging head  12  into the section K′ with the constant width. 
         [0068]      FIG. 4C  shows a schematic plan view from the front, in particular from the desired direction R 2 ′, of an electric connection device of a vehicle for charging a battery of the vehicle according to the first embodiment of the second aspect of the present invention. 
         [0069]      FIG. 4C  depicts five guide slots  116 , in each of which two of the second electric contacts  114  are formed. 
         [0070]      FIG. 5A  shows a schematic detailed view from above, that is to say from the direction of the vehicle, of the receiving head  112  of the connection device  110  according to the first embodiment of the second aspect of the present invention. 
         [0071]    According to  FIG. 5A , the ten second electric contacts  114  are formed parallel to one another and at a distance from one another and perpendicular to the second surface  113 . The second contacts  114  are each in the form of electrically conductive strips inside the five guide slots  116 . The two second contacts  114  arranged inside the same guide slot  116  are each connected to one another via two bracket-shaped leaf springs  122 , one leaf spring  122  at each of the two longitudinal ends of the two strips. The ten leaf springs  122  each exert a spring force which presses each strip in the direction of the strip opposite it inside the same guide slot. Particularly good contact-connection is therefore possible if a first contact  14  is respectively inserted between the two strips. 
         [0072]    The strips have beveled edges  117  toward the interior of the respective guide slot  116  in the longitudinal direction of the second electric contacts  114 , that is to say in particular in a direction along the channel K of the connection device  110 , with the result that the first electric contacts  14  can enter even more easily between the two second contacts  114  in the guide slot  116 . 
         [0073]    The five guide slots  116 , the ten leaf springs  122 , the twenty screws  120  and the ten second electric contacts  114  all have the same design according to the present embodiment. For the sake of clarity, only a selection of the elements has therefore respectively been provided with reference symbols in  FIG. 5A . 
         [0074]    As discussed with reference to  FIG. 3 , the first electric contacts  14  can perform a multiplicity of functions. In a manner corresponding to the configuration of the charging head  12 , one or more of the second contacts  114  may be in the form of a protective line, a phase line, a high-voltage line, a low-voltage line etc. for the purpose of transmitting data and/or control signals. 
         [0075]    The second electric contacts  114  may also be in the form of strips of the same length in each case inside the guide slots  116 . However, some or all of the second electric contacts may also have different lengths. Some or all of the second electric contacts may also be arranged in a manner offset from one another with respect to a direction along the guide slots  116 . As a result, if the first electric contacts  14  all have an identical design, for instance, different contacts are produced in a temporally offset manner, for instance in a similar manner to that described with reference to  FIG. 3 . 
         [0076]    At least one of the second electric contacts  114  is directly or indirectly connected to the battery for the purpose of charging the battery of the vehicle. A charging device may be formed as part of the connection device  110  of the vehicle and can be controlled by means of the first control device of the charging device  10  and/or by means of the second control device of the connection device  110  via a predetermined one of the second electric contacts  114  in the case of contact with a predetermined one of the first electric contacts  14 . The charging of the battery can be controlled by means of the charging device via two further predetermined second electric contacts  114 , for example. 
         [0077]      FIG. 5B  shows a schematic detailed view from the front of [[a]] the receiving head of the connection device according to the first embodiment of the second aspect of the present invention. It is clear from  FIG. 5B  that edges of the second contacts  114  which are parallel to the plate P and point away from the plate P also have bevels  117 ′ pointing in the direction of the interior of a respective guide slot  116 , with the result that the first electric contacts  14  can enter even more easily between the two second contacts  114  in the guide slot  116 . 
         [0078]      FIG. 6  shows a schematic flowchart of a method according to the invention according to a third aspect of the present invention. For details and advantageous developments of the described method, reference is made to the preceding and subsequent figures and to the associated descriptions of the charging and connection devices according to the invention. 
         [0079]    In a first method step S 01 , the lifting device  11  is actuated by means of the actuator  16  in such a manner that the charging head  12  connected to the lifting device  11  is at least partially moved in the first direction R 1  and also in such a manner that, if the charging head strikes a stop surface in the first direction, the charging head  12  moves in the second direction R 2 . 
         [0080]    In a second method step S 02 , the charging head  12  moving along the stop surface U, P is guided, by means of the guide device  118 , into the predetermined charging position with respect to the receiving head  112  having the second electric contacts  114 . 
         [0081]    In a third method step S 03 , the battery of the vehicle F is charged from the energy source via the first and second electric contacts  14 ,  114 . 
         [0082]      FIG. 7  shows a charging head  12 ′ of an electric charging device for charging a battery of the vehicle according to a second embodiment of the first aspect of the present invention. 
         [0083]    The charging head  12 ′ according to the second embodiment is a variant of the charging head  12  according to the first embodiment, three first electric contacts  14 - 1 ,  14 - 2 ,  14 - 3 , or  14 - i  for short, being formed on the first surface  13 . A conductive torus is formed on the first surface  13  for this purpose and is divided, by means of two electrically insulating insulation blocks  51 ,  52 , into two regions which are electrically separate from one another and each of which constitutes an individual first contact  14 - 1 ,  14 - 2 . A further first contact  14 - 3  is in the form of an arc between the insulation blocks  51 ,  52  and is electrically contact-connected via connections inside the insulation blocks  51 ,  52 . 
         [0084]      FIG. 8  shows an electric connection device  110 ′ of a vehicle for charging a battery of the vehicle according to a second embodiment of the second aspect of the present invention. 
         [0085]    The electric connection device  110 ′ is designed to receive the charging head  12 ′ according to the second embodiment of the first aspect of the present invention and is substantially a variant of the connection device  110 . The connection device  110 ′ has a guide device  118 ′, the channel K″ of which, in contrast to the channel K of the guide device  118 , does not taper in a v-shaped manner on both sides, but rather tapers on both sides in a trumpet-shaped manner to the receiving head  112 ′ of the connection device  110 ′. The receiving head  112 ′ has three second electric contacts  114 - 1 ,  114 - 2 ,  114 - 3 , or  114 - i  for short. Two of the second contacts  114 - 1 ,  114 - 2  are formed on inner walls of the channel K″ and one of the second contacts is formed directly on the plate P of the connection device  110 ′ in the center of the channel K″ between the second contacts  114 - 1 ,  114 - 2 . The contacts  114 - 1 ,  114 - 2 ,  114 - 3  are protected by a cover  108  which is displaceably suspended from four springs  106 . 
         [0086]    The connection device  110 ′ according to the second embodiment of the second aspect and the charging device  10 ′ according to the second embodiment of the second aspect of the present invention may together constitute a second embodiment of the charging system according to the invention. 
         [0087]    In this case, the second contact  114 - 1  contact-connects the first contact  14 - 1 , the second contact  114 - 2  contact-connects the first contact  14 - 2  and the second contact  114 - 3  contact-connects the first contact  14 - 3  in the predetermined charging position. For this purpose, the torus of the charging head  12 ′ is completely inserted into the channel K″ of the guide device  118 ′. In this case, the cover  106  is automatically pushed back. 
         [0088]    Although the present invention was described above using preferred exemplary embodiments, it is not restricted thereto, but rather can be modified in various ways. In particular, the invention can be changed or modified in various ways without departing from the essence of the invention. 
         [0089]    For example, instead of the first and second torsion springs  31 ,  32 , it is also possible to use other springs, for instance spiral springs having longitudinal axes perpendicular to the axes of rotation of the first and second rotating joints  41 ,  42 . 
         [0090]    The guide may also be in the form of a smooth, lubricated outer surface and the slide may be designed with a smooth inside. In this case, the actuator may be a linear actuator, for example a pneumatic actuator or a magnetic actuator. The guide of the charging device may also have a further spring, as a result of which a counterforce acts on the slide when it approaches the first bearing block. 
         [0091]    The charging head of the charging device may be protected by a cover which is suspended from the charging head  12 ;  12 ′ with springs. The cover may be designed and the springs may be selected in such a manner that, when the charging head is pressed against the guide device of the connection device, for instance, the cover is automatically pushed back in order to release the first electric contacts  14 ;  14 - i . The connection device  110 ;  110 ′ can also be protected by a cover which is suspended from springs and, when the charging head  12 ;  12 ′ is pressed against the cover, is automatically pushed back in order to release the second electric contacts  114 ;  114 - i.    
         [0092]    Insides of the covers on the charging head  12 ;  12 ′ and on the receiving head  112 ;  112 ′ may be formed in such a manner that the contacts  14 ,  114 ;  14 - i ,  114 - i  are covered in a form-fitting manner. This makes it possible to prevent small foreign objects from being deposited on the contacts  14 ,  114 ;  14 - i ,  114 - i , for example cigarette butts. The form-fitting coverage can be achieved by means of a cover which is formed like a negative of the respective contacts  14 ,  114 ;  14 - i ,  114 - i . That is to say, the first contacts  14 ;  14 - i  are covered with a form which is like the second contacts  114 ;  114 - i  and vice versa. 
         [0093]    The charging device may also itself be arranged in a cavity or a housing which is closed, toward the top, by a trapdoor or sliding door, for example in order to protect the charging device from rain. It is possible to provide a coarse sensor system which determines whether a vehicle to be charged is in the predetermined area around the charging device. If this is the case, the trapdoor or sliding door is automatically opened and the actuator of the charging device is then actuated.