Abstract:
The invention relates to a locking unit for a first flap, a second flap and a carrier, comprising a locking element which can be housed in a displaceable manner on the first flap and which comprises a tappet, and a driveable actuation device which is used to displace the locking element. In a first position, said locking element couples the first flap to the second flap in order to form a unit, and in a second position, the first flap is released from the second flap, and in an intermediate position, the first flap and the second flap are fixed together in the carrier. An active connection between the tappet of the locking element and the actuation element can be formed in said intermediate position.

Description:
The invention relates to a locking unit according to the present invention for a first flap, a second flap and a support. 
     BACKGROUND 
     DE 10 2006 013 735 A1, published after the priority date of the present application, shows a locking unit, in which the first flap is designed as a tailgate of a motor vehicle, the second flap is designed as a trunk flap of the motor vehicle and the support is designed as the bodywork of the motor vehicle, wherein, in a first position, the trunk flap can be coupled to the tailgate to form a unit, and therefore the unit comprising the tailgate and the trunk flap is articulated on the bodywork in a manner such that it can pivot about a tailgate axis. In a second position, the tailgate is fixed to the bodywork, with the trunk flap on the tailgate being pivotable about a trunk flap axis in order only to open up the trunk. The trunk flap is articulated rotatably via a pivoting arm, wherein a laterally protruding journal is arranged on the pivoting arm, and wherein, in the first position, the journal is engaged around by a locking element. The locking element comprises a pin, an elongate portion in the form of a hook which directly surrounds the journal, and a driver in the form of a guide element, which acts as a lever, with a longitudinal extent in a direction perpendicular to the axis of rotation. An actuating unit which comprises a U-shaped receptacle is provided for actuating the locking element, with the guide element engaging in an essentially form-fitting manner in the U-shaped receptacle in order to produce an operative connection between the actuating device and the locking element. The actuating device furthermore comprises a pivoting hook with an indentation. The U-shaped receptacle is fastened to a first driving means of a double mechanism, and the pivoting hook is fastened to a second driving means of a double mechanism. For the actuation of the locking element, the guide element therefor engages in the U-shaped receptacle of the actuating device and said actuating device rotates the locking element in a first direction of rotation, and, furthermore, the pivoting hook is rotated in a second direction of rotation in such a manner that it engages over the pin of the locking element. One drawback is that the actuating device is overall of multi-part and complicated construction, with a further drawback being that the locking element assigned to the actuating device likewise has to be of complicated configuration. Yet another drawback is that the locking unit is prone to failure; in particular, the double mechanism, in a configuration as a mechanism with gearwheels, can rapidly fail in the event of damage or of the penetration of a foreign body. Another drawback is that only a very indirect operative connection can be produced between the locking element and the drive, via the double mechanism, the U-shaped receptacle and the guide element of the locking element, and therefore a powerful driving device is required, a comparatively high degree of wear occurs and, over time, tolerances can accumulate to form an undesirable amount of play. Another drawback is that a high amount of torque has to be exerted on the guide element of the locking element in order to rotate the locking element, and therefore high mechanical loads occur. Better torque ratios require a significant longitudinal extent of the guide element, but the locking unit would take up a large amount of installation space as a result. A further drawback is that, due to the pin, the guide element is at a distance from the locking element and the pivoting hook is at a distance from the guide element, and therefore the locking unit overall needs a large amount of space, in particular in a direction defined by the pin. 
     EP 0 718 134 B1=DE 695 12 749 T2 shows a vehicle with a divided tailgate which has a first flap part provided with a rear window and a second flap part designed as a trunk lid. The first flap part is articulated on the bodywork in a manner such that it can pivot about a pivot axis. In a region facing away from the pivot axis, a plate is fastened to the first flap part, which plate protrudes over the lower edge of said flap part and at which the second flap part is articulated pivotably on the first flap part via a four-bar linkage. The second flap part is conventionally lockable to the bodywork. In the event that only the second flap part is to be opened, the first flap part can be fixed in a hook of the bodywork via a laterally protruding journal. One drawback here is that, when the flap parts are open together, they are no longer fixed relative to each other, and therefore a pivoting of the two flap parts relative to each other is possible. Furthermore, the tailgate requires two separate gas-filled compression springs as supporting means. 
     DE 196 15 540 A1 describes a pivotable tailgate with an encircling frame in which a rear window and a loading flap are accommodated and are mounted in a manner such that they can be pivoted separately from the tailgate. In this case, conventional locking means are provided in each case for the locking of the rear window and the loading flap to the frame and relative to each other. 
     DE 198 08 374 A1 describes a means of locking a flap of a motor vehicle, such as, for example, the front lid of a motor vehicle. In this case, the bow of a lock, which is arranged on the bodywork and the axis of which is essentially perpendicular to the pivot axis of the flap, is engaged around by a locking device, which is arranged on the flap, in order to lock the flap. The locking device comprises a rotary latch and a fork which are both pivotably mounted adjacent to each other on a common, first axis and grasp the bow by means of respectively provided openings. A first drive drives the bow latch by a gearwheel mechanism for rotation about the first axis. The bow latch carries along the fork in its rotational movement in a form-fitting manner by means of an offset and pivots into a parking position which is rotated through approximately 180° and in which the parts of the locking device no longer protrude over the border of the flap. Bow latch and fork are held in their locked position by a respectively assigned pawl and are both mounted on a common, second axis and can be pivoted by a second drive. 
     DE 33 37 202 A1 describes a means of locking a flap of a motor vehicle, such as, for example, the front lid of a motor vehicle. In this case, the bow of a lock, which is arranged on the flap, is engaged around by a locking device, which is arranged on the flap, in order to lock the flap. The locking device can be pivoted on an axis which is prestressed in the direction of a release position by a spring. The locking device has a main sliding track for the guide of the bow, the lower end of which track defines the closed position and the upper end of which merges into a lower edge which defines a stop and springs back in the manner of a hook. An upper edge of the hook serves as an introductory aid for the bow, and therefore, after the tip of the hook is exceeded in the course of the closing movement, the spring pivots the locking device in such a manner that the bow comes to bear against the main sliding track and, by further lowering, pivots the locking device again counter to the prestressing of the spring until the bow reaches the closed position. By means of a secondary sliding track which is formed essentially opposite the main sliding track, it is ensured that, during the opening operation, the locking device is pivoted, even if the spring should fail, in such a manner that the bow passes under the stop. An introductory sliding track which is formed on the side of the secondary sliding track, points upward and merges into the secondary sliding track in a manner similar to a wedge ensures that the locking device which is not oriented in the release position should the spring fail is pivoted by the bow striking against it in such a manner that the latter passes again into the region of the main sliding track. 
     SUMMARY OF THE INVENTION 
     It is the object of the invention to provide a locking device which is constructed in a simple manner and is reliable in operation. 
     This object is achieved according to the invention for the locking unit by the characterizing features of claim  1  as follows. 
     By the driver being held in an elongated hole of the locking disk which is then moved relative to the initially stationary driver, it is ensured that a force is exerted on the driver and therefore an operative connection between the actuating device and the locking element is produced only when the driver is arranged at the second end of the elongated hole, as a result of which an inadvertent emergence of the driver from the elongated hole can be avoided. In particular, the coupling between the second flap and the first flap is released only when it is imparted, by means of the driver which is held securely in the elongated hole, that the first flap is held on the support, and therefore a release of the second flap from the first flap and from the support at the same time can be reliably and simply prevented. 
     The locking disk is simple to fit, and therefore the locking unit only comprises a few individual parts. In particular, it is advantageous that, in a single movement in a first movement phase, the locking disk permits the second flap to be fixed on the support and, in a continuation of the movement in a second movement phase, permits release of the second flap from the first flap to be carried out. Such a sequence of movement can easily be controlled, does not require a complicated mechanism and can easily be monitored. 
     Furthermore, it is advantageous that, in the intermediate position, the driver of the locking element, which driver is held at the second end of the elongated hole, brings about an essentially direct coupling, without further intermediate steps, between the drive of the locking disk and the locking element to be actuated. 
     It is furthermore advantageous that the locking unit is of robust and compact configuration and, in particular, can be provided as a premanufactured unit. 
     In addition to the locking disk, the locking unit preferably comprises a locking plate which is fastened to the support and has a bore which is at least partially passed through by the driver, and therefore, in addition to the guidance made possible by the elongated hole of the locking disk, provides a further possibility of preventing the driver from breaking out of a predetermined trajectory, and therefore, furthermore, in the second position, the drive can be switched off and the driver and, by means of thereof, the locking element can be fixed to the support by means of the locking plate. The profile of the bore of the locking plate is then provided by the trajectory described by the guided driver. 
     The locking disk is preferably mounted on the support in a manner such that it can rotate about a locking disk axis, and therefore the movement of the locking disk essentially corresponds to a simply activatable rotational movement about a maximum angle. 
     The locking element preferably has a lever with a lever axis, and the driver is designed as a handle of the lever, as a result of which the locking element can be actuated in a simple manner. 
     If the lever axis of the lever is arranged as an extension of the locking disk axis, it is ensured that the lever can only be actuated if a force acts on the handle of the lever and interfering effects are reduced by friction between the driver, which is designed as the handle of the lever, and the elongated hole of the locking disk, which hole receives the handle. The elongated hole is preferably configured in such a manner, for example by means of a formation of an introductory edge or a guide surface at the open end of the elongated hole, that, in a first section of the rotation of the locking disk, the two axes are brought into overlap while the bolt is pulled into the locking plate counter to the mechanical resistance, for example of a trunk seal. 
     The locking disk preferably comprises a blind hole which is connected at a first end to the elongated hole, the blind hole, at a second, closed end, receiving a further guide means of the locking element, which guide means is provided in addition to the driver, and a defined, reproducible alignment of the locking element relative to the actuating unit being possible. If, in particular, a handle is provided as the driver, the further guide means can be designed as a guide pin which is connected fixedly to the driver. 
     At the first end, the elongated hole preferably has a guide surface with which the driver, which is arranged at the first end of the elongated hole in the first position, interacts during the further course of the movement of the locking disk. In particular, it can be provided to configure the guide surface in such a manner that the elongated hole tapers in the vicinity of the first end such that the driver can be reliably inserted into the elongated hole and tolerances which may occur in the relative position between the driver and the first end of the elongated hole are compensated for. 
     As an alternative to a rotatable locking element, the locking element can be mounted in a longitudinally displaceable manner, for example as a slide which is accommodated on the first flap and, in the first position, couples the first flap to the second flap by the slide passing through a section of the second flap. If the locking element is designed as a slide, the driver can be designed as a pin which protrudes laterally from the said locking element and is received and guided by the elongated hole. 
     Further advantages and features of the invention emerge from the description below of preferred exemplary embodiments and from the dependent claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is described and explained in more detail below using two exemplary embodiments of a locking unit according to the invention and with reference to the attached drawings. 
         FIG. 1   a  shows a perspective view of a locking element, which is equipped with a mechanism, of a locking unit; 
         FIG. 1   b  shows a perspective view of an actuating device for the locking element from  FIG. 1   a,    
         FIG. 2  shows a perspective view of the locking unit with the actuating device from  FIG. 1   b  and the locking element from  FIG. 1   a  in an intermediate position; 
         FIG. 3   a  shows a perspective view of the actuating device from  FIG. 2  in a first position, 
         FIG. 3   b  shows a perspective view of the actuating device from  FIG. 2  in the intermediate position, 
         FIG. 3   c  shows a perspective view of the actuating device from  FIG. 2  in a second position, 
         FIG. 4  shows a perspective view of a first exemplary embodiment of a locking unit according to the invention in a first position, 
         FIG. 4   a  shows a perspective view of an enlarged detail of the first exemplary embodiment from  FIG. 4 , 
         FIG. 5  shows a perspective view of the first exemplary embodiment from  FIGS. 4 and 4   a  in an intermediate position, 
         FIG. 5   a  shows a perspective view of an enlarged detail of the first exemplary embodiment from  FIG. 5 , 
         FIG. 6  shows a perspective view of the first exemplary embodiment from  FIGS. 4 to 5   a  in a second position, 
         FIG. 6   a  shows a perspective view of an enlarged detail of the first exemplary embodiment from  FIG. 6 , 
         FIG. 7  shows a perspective view of a second exemplary embodiment of a locking unit according to the invention in a first position, 
         FIG. 8  shows a perspective view of the second exemplary embodiment from  FIG. 7  in a position approximate to an intermediate position, and 
         FIG. 9  shows a perspective view of the second exemplary embodiment from  FIGS. 7 and 8  in a second position. 
     
    
    
     DETAILED DESCRIPTION 
     It should be mentioned first that, for  FIG. 1  to  FIG. 9 , the support is in each case designed as the bodywork of a motor vehicle, the first flap is in each case designed as a tailgate which is articulated in a manner such that it can rotate about a tailgate axis (not illustrated) on the bodywork, and the second flap is designed as a trunk flap, with the trunk flap being articulated in a manner such that it can rotate about an indicated trunk flap axis (axis  258  in  FIG. 9 ) on the tailgate. The locking unit is spaced apart from the tailgate axis and from the trunk flap axis. If, in the first position of the locking unit, the tailgate is coupled to the trunk flap, then said assembly is also rotatable as a unit about the tailgate axis. If, in the second position, the trunk flap is decoupled from the tailgate, then the tailgate is fixed to the bodywork in the region of the locking unit and the tailgate axis is no longer rotatable with respect to the bodywork. By contrast, in the second position, the trunk flap is articulated in a manner such that it can rotate about the trunk flap axis on the tailgate. 
       FIG. 1   a  shows a locking element  1  of a locking unit. The locking element  1  comprises an essentially disk-shaped body  2  with an introductory slot  3 . The locking element  1  furthermore comprises a pin  4  which protrudes essentially perpendicularly from the body  2 , with a guide element  5  being provided at one end of the pin  4 , said guide element having a longitudinal extent such that side surfaces  5   a  of the guide element  5  are designed as guide surfaces. The guide element  5  is connected in a rotationally fixed manner to the body  2  of the locking element  1  via the pin  4  and is spaced apart from the body  2 . A curved, elongate section  6  is formed on the body  2  adjacent to the introductory slot  3 . 
       FIG. 1   a  shows the locking element  1  in a position in which the elongate section  6  engages around a journal  7  in the manner of a hook, the journal  7  being arranged at one end of the introductory slot  3 . The journal  7  is fastened to an arm  8  (only partially illustrated) of a second flap (not illustrated in  FIG. 1   a ). The journal  7  defines a journal axis  9  and the pin  4  defines a lever axis  10  which is spaced apart from the journal axis  9 , and therefore a rotation of the locking element  1  about the lever axis  10  brings the journal  7  out of engagement with the introductory slot  3  and also releases it with respect to the elongate section  6 . The locking element  1  is held on a projection  11  of a first flap (not illustrated specifically in  FIG. 1   a ) in a manner such that it can rotate about the lever axis  10 . In order to release the journal  7  from the locking element  1 , it is necessary for a torque to be exerted on the locking element  1 , for which purpose an external force acts, in particular, on the guide element  5  which therefore acts as a lever for the locking element  1 . 
       FIG. 1   b  shows an actuating device  12  for the locking element  1  from  FIG. 1 , with the actuating device  12  being fitted to a support (not illustrated). The actuating device  12  comprises a pivoting hook  13  with an indentation  14  having an open end  14   a  and a closed end  14   b . The actuating device  12  furthermore comprises a U-shaped receptacle  15  which is configured with respect to the guide element  5  ( FIG. 1   a ) in such a manner that the side surfaces  5   a  of the guide element  5  can be held in an essentially form-fitting manner between the limbs of the U. The U-shaped receptacle  15  is connected in a rotationally fixed manner to a first gearwheel  17  in so far as an angle-limiting free movement is incorporated between the receptacle  15  and the first gearwheel  17  in order to retard the movements with respect to each other. The pivoting hook  13  interacts with a second gearwheel  16 , with the first gearwheel  17  merging with the second gearwheel  16 . The actuating device  12  is assigned a drive  18  which sets a third gearwheel  19 , which engages together with the second gearwheel  16 , into rotation. 
       FIG. 2  shows a locking unit, which comprises the locking element  1  from  FIG. 1   a  and the actuating unit  12  from  FIG. 1   b , in a position in which an operative connection is produced between the drive  18  and the locking element  1 , and therefore the locking element  1  can be actuated by means of the drive  18 . In the position illustrated in  FIG. 2 , the guide element  5  of the locking element  1 , which guide element is designed as a driver, is held by the side surfaces  5   a  in the U-shaped receptacle  15  of the actuating device  12 . The journal  7  is still engaged around by the elongate section  6  of the locking element  1 , and the pin  4  of the locking element  1  is not yet engaged over by the pivoting hook  13 , and therefore the pin  4  is not yet accommodated in the indentation  14 . It should be noted that an operative connection occurs only between the guide element  5  of the locking element  1 , which guide element is designed as a driver, and the U-shaped receptacle  15  of the actuating device  12 . 
       FIG. 3   a  shows the locking device in a first position, in which the actuating device  12  and the locking element  1  are not in operative engagement. The locking element  1  is fastened rotatably to the projection  11  of the first flap (not illustrated) and engages by means of the section  6  over the journal  7  fastened to the arm  8  of the second flap (not illustrated). It should be noted that the second flap is articulated rotatably about an axis of rotation  158  on the first flap, the axis of rotation  158  of the second flap on the first flap being at a distance from the journal  7 , and therefore the journal  7 , which is engaged around by the locking element  1 , prevents a rotation of the second flap about its axis of rotation on the first flap such that the first flap and the second flap are coupled to form a rigid unit. Since the first flap, for its part, is articulated rotatably about an axis of rotation (not illustrated) on the support, in the first position illustrated in  FIG. 3   a  the assembly comprising the first flap and the second flap can be pivoted as a whole with respect to the support about the axis of rotation of the first flap. 
     The position in  FIG. 3   b  essentially corresponds to the position which is illustrated in  FIG. 2  and in which the actuating device  12  enters into operative connection with the locking element  1  via the guide element  5  which engages in the U-shaped receptacle  15  of said actuating device. 
       FIG. 3   c  shows a second position of the locking unit, after the actuation thereof because of the drive  18 . In comparison to the position illustrated in  FIG. 3   b , the U-shaped receptacle  15  is rotated in the counterclockwise direction and, as a result, the locking element  1  is likewise rotated in the counterclockwise direction in such a manner that the journal  7  on the arm  8  of the second flap has come out of engagement with the section  6  of the locking element  1  and is therefore released such that the second flap is only still mounted pivotably at its axis of rotation on the first flap and is therefore released for pivoting in relation to the first flap. Owing to the opposed movement of the two gearwheels  16  and  17 , the pivoting hook  13  is pivoted in the clockwise direction and the pin  4  of the locking element  1  is accommodated in the closed end  14   b  of the indentation  14 . Overall, the locking element  1  and therefore also the first flap are fixed on the support, with a pivoting of the first flap about its axis on the support no longer being possible in the second position. 
       FIG. 4  shows the first exemplary embodiment, wherein a journal  107 , which is engaged around by a locking element  101 , is arranged on an arm  108  which is connected rigidly to a second flap (not illustrated). A body  102  of the locking element  101  is designed comparably to the body  2  of the locking element  1  from  FIG. 1  to  FIG. 3   c  and has an introductory slot  102  which, at one end, receives part of the journal  107  in an approximately form-fitting manner. The locking element  101  differs from the locking element  1  in so far as the locking element  101  has a driver which is designed as a cylindrical bolt  120  and is connected rigidly via a web  121  to a further, cylindrical guide pin  122 , thus forming a lever  123  which is rotatable about an axis of rotation  110  which essentially corresponds to an axis  124  of the guide pin  122 . The guide pin  122  is connected in a rotationally fixed manner to the body  102  of the locking element  101 , and therefore a force which acts on the bolt  120  permits rotation of the locking element  101 . In this case, the cylindrical bolt  120  is designed as a handle of the lever  123  which is rotatable about the axis of rotation  110 . The locking element  101  is held rotatably on a projection  111  of the first flap (not illustrated specifically). 
       FIG. 4  furthermore shows an actuating device  112  for the locking element  101 . The actuating device  112  comprises a locking disk  125  which can be driven by a drive  118  via a mechanism  126  such that it rotates, with the locking disk  125 , in the first exemplary embodiment, being mounted rotatably on the support, specifically the bodywork of the motor vehicle, in a manner such that it can rotate about a locking disk axis  127 , for which purpose the mechanism  126  acts on the locking disk  125  at a distance from the locking disk axis  127 . In addition to the locking disk  125 , the actuating device  112  comprises a locking plate  128  which is arranged fixed to the support. In the illustration of  FIG. 4 , the locking plate  128  largely covers the locking disk  125 . 
       FIG. 4   a  shows the locking disk  125  and the locking plate  128  from  FIG. 4 , with the viewing direction along the locking disk axis being selected in a direction opposite to  FIG. 4  such that the locking disk  125  can be seen in front of the locking plate  128 . The locking disk  125  comprises an essentially triangular body  129 , the corners of which are rounded. An elongated hole  130  is arranged on the body  129  of the locking disk  125 , the elongated hole  130  having a first, open end  131  and a second, closed end  132 . The second end  132  of the elongated hole  130  is of essentially semicircular configuration. The locking disk  125  furthermore comprises a blind hole  133  with a first, closed end  134  and a second end  135 , the second end  135  of the blind hole  133  coinciding with the first end  131  of the elongated hole  130 . The first end  134  of the blind hole  133  is provided with an essentially semicircular contour, with an imaginary center point of the semicircle lying on the locking disk axis  127 . At the first, open end  131  of the elongated hole  130 , the latter is widened approximately in the manner of a funnel and forms a guide surface  136 . At the first end  131  of the elongated hole, the body  129  forms an introductory edge  137 . 
       FIG. 4   a  shows the locking plate  128  with a body  138  and a bore  139 , the first, open end  140  of which is partially covered in  FIG. 4   a  by the locking disk  125  and the second, closed end  141  of which is of essentially semicircular design. The locking plate  128  furthermore comprises an introductory opening  142  with a first, open end  143  and a second, closed end  144 . In the first position, illustrated in  FIG. 4   a , of the locking unit, the locking disk  125  is oriented with respect to the locking plate  128  in such a manner that the blind hole  133  of the locking disk  125  largely comes to overlap with the introductory opening  143  of the locking plate  128  along a sight line defined by the locking disk axis  127 ; in this case, a wall section  145  of the blind hole  133  of the locking disk  125  covers the first, open end  140  of the bore  139  of the locking plate  128 . Furthermore, a wall section  146  of the introductory opening  143  of the locking plate  128  covers the first, open end  131  of the elongated hole  130  of the locking disk  125 . 
       FIG. 4   a  furthermore shows the bolt  120 , which is provided as the driver, and the guide pin  122 , which are connected rigidly to each other via the web  121  and serve overall as a lever  123  for the actuation of the locking element  101  (not illustrated), with the bolt  120  which is provided as the driver being designed as the handle of the lever and being arranged at a distance from the lever axis  110 . 
       FIGS. 5 and 5   a  show the locking unit in the first intermediate position. The locking disk  125  is rotated relative to the support by the drive  118  in the counterclockwise direction about the locking disk axis  127  in such a manner that the bolt  120  which is designed as the driver is arranged at the second, closed end  132  of the elongated hole  130  of the locking disk  125 . The guide pin  122  is accommodated at the second, closed end  134  of the blind hole  133  of the locking disk  125  and at the second, closed end  144  of the introductory opening  142  of the locking plate  128  in such a manner that the axis  124  of the guide pin  122  essentially lies as an extension or continuation of the locking disk axis  127 . The locking element  101 , only part of which is visible in  FIG. 5 , has not changed its position in comparison to the position shown in  FIG. 4 , and therefore the first flap and the second flap are still coupled to the unit. However, the introductory edge  137  or the guide surface  136  of the elongated hole  130  of the locking disk  125  engages over the first, open end  143  of the introductory opening  142  of the locking plate  128  in such a manner that the bolt  120  which is designed as the driver is unable to move out in a direction which is approximately provided by an imaginary connecting line between the bolt  120  and the guide pin  122  (and which approximately corresponds to the longitudinal extent of the web  121  (which cannot be seen) from  FIG. 4 ). The bolt  120  is furthermore located at the first, open end  140  of the bore  139  of the locking plate  128 . 
       FIGS. 6 and 6   a  show the locking unit in the second position. In this case, the driver which is designed as a bolt  120  is arranged at the second, closed end  132  of the elongated hole  130  of the locking disk  125 . In comparison to the position illustrated in  FIGS. 5 and 5   a , the locking disk  125  is rotated further in the clockwise direction (to the left during locking) about the locking disk axis  127 . The bolt  120  is arranged at the second, closed end  141  of the bore  139  of the locking plate  128 . In comparison to the position illustrated in  FIGS. 5 and 5   a , the position of the guide pin  122  at the first, closed end  134  of the blind hole  133  of the locking disk  125  and at the second, closed end  144  of the introductory opening  142  of the locking plate  128  is unchanged. 
     As is apparent in  FIG. 6 , the locking element  101 , only part of which can be seen, is rotated to the left in the clockwise direction in such a manner that the journal  107  on the arm  108  is no longer engaged around and the second flap is released from the first flap. 
       FIG. 7  shows the second exemplary embodiment of a locking unit which comprises a locking element  201  arranged on a first flap (not illustrated specifically) and an actuating device  212  assigned to the locking element  201 , with it being possible for the actuating device  212  to be driven by a motorized drive  218 . 
     The locking element  201  comprises a slide  250  which is mounted in a longitudinally displaceable manner in a receptacle  251  coupled fixedly to the first flap. In the first position, the slide  250  passes in an essentially form-fitting manner through a guide section  252 , which is arranged fixedly on the second flap, such that the first flap and the second flap are coupled to form a rigid unit by the slide  250  passing through the receptacle  251  and the guide section. A laterally protruding pin  253  is arranged on the slide  250  and is guided in a longitudinally displaceable manner in a guide  254 , the guide  254  being designed in the manner of an elongated hole, with a first, closed end  255  and a second, closed end  256 , the pin  253  of the slide  250  being arranged at the first end  255  of the guide  254  in the first position of the locking unit. The pin  253  is designed as a driver for the actuating device  212 . 
     The actuating device  212  comprises a first locking plate  228   a  and a second locking plate  228   b , which are both fastened to the support (not illustrated), and a first locking disk  225   a , which is fastened rotatably to the first locking plate  228   a , and a second locking disk  225   b , which is fastened rotatably to the second locking plate  228   b , with the first locking disk  225   a  being connected rigidly to the second locking disk  225   b  and being rotatable about a common locking disk axis  227 . The first locking disk  225   a  and the first locking plate  228   a  are constructed mirror-symmetrically to an imaginary center plane with respect to the second locking disk  225   b  and the second locking plate  228   b , and therefore only the construction of the first locking plate  228   a  and that of the second locking disk  225   b  are described below, with the understanding that the second locking plate  228   b  and the first locking disk  225   a  are of comparable configuration. It should also be noted that the first locking disk  225   a  or the first locking plate  228   a  interacts with the pin  253  (which can be seen in  FIG. 7 ) of the slide  250  of the locking element  201 . In addition, the locking element  201  comprises a further slide  253 ′, which is concealed in  FIGS. 7 to 9 , of the slide  250  which interacts with the second locking plate  228   b  or the second locking disk  225   b.    
     The first locking plate  228   a  comprises a body  229  with a bore  239  which has a first, open end  240  and a second, closed end  241 . The second locking disk  225   b  comprises a body  229  which has an elongated hole  230  with a first, open end  231  and a second, closed end  232 . At the first end  231 , the elongated hole  230  has an introductory edge  237  which is adjoined along the extent of the elongated hole  230  by a guide surface  236 , with the elongated hole  230  tapering along the guide surface  236  to the second, closed end  232  of the elongated hole  230 . 
     In the first position, illustrated in  FIG. 7 , of the locking unit, the pin  253  of the slide  250 , which pin is designed as a driver, is not in engagement with the actuating device  212 . The locking disks  225   a  and  225   b , which can be driven by motor and have the elongated holes  230 , are oriented with respect to the locking plates  228   a ,  228   b  in such a manner that first ends  231  of the elongated holes  230  of the locking disk  225   a  ( 225   b ) together with the first ends  240  of the bores  230  of the locking plate  228   a  ( 228   b ) respectively form a receptacle for the pin  253  and for the further pin (which cannot be seen) of the slide  250 . 
       FIG. 8  shows the locking unit in a position which is approximate to the intermediate position and in which the slide  250  passes both through the receptacle  251  on the first flap and through the guide section  252  of the second flap and therefore fixes the two flaps to each other. The pin  253  is located at the first, open end  240  of the bore  239  of the locking plate  228   a  or  228   b . In comparison to the illustration shown in  FIG. 7 , on account of the motorized drive  218 , the locking disk  225   a ,  225   b  is pivoted in the counterclockwise direction, and therefore the pin  253  is accommodated within the elongated hole  230  and is arranged there between the first, open end  231  and the second, closed end  232 . The pin  253  is in contact here with the guide surface  236  of the elongated hole  230 . The intermediate position is only reached when the pin  253  arrives at the second, closed end  232  of the elongated hole  230 , and therefore only then is there an operative connection between the drive  218 , via the elongated hole  230  and the pin  253 , and the locking element  201 . Even before the intermediate position is reached, the introductory edge  237  has completely engaged over the pin  253 , and therefore it is no longer possible for the pin  253  to exit from the receptacle formed beforehand by the first end  231  of the elongated hole  230  and the first end  240  of the bore  239 . 
       FIG. 9  shows the locking unit in the second position, with the slide  250  being longitudinally displaced in the receptacle  251  on the first flap in such a manner that the slide  250  no longer passes through the guide section  252  on the second flap. The second flap is therefore no longer fixed to the first flap in the region of the slide  250 . Since the second flap is articulated rotatably about an axis  258  on a projection  257  of the first flap, the second flap can be pivoted relative to the first flap about the axis  258 . 
     In  FIG. 9 , it can furthermore be seen that, in the second position, the pin  253  is arranged in the vicinity of the second, closed end  241  of the bore  239  of the locking plate  228   a  (or in a corresponding manner for the further pin (which cannot be seen) for the locking plate  228   b ). An end stop for the pin  253  is provided by the second end  256 , concealed in  FIG. 9 , of the guide  254  such that the guide  254  determines the displaceability of the pin  253  in the bore  239 .  FIG. 9  does not illustrate the first locking disk  225   a  which has grasped the pin  253  at the second end  232  of the elongated hole  230  ( FIGS. 7 and 8 ) in the intermediate position and has guided it into the second position which can be seen in  FIG. 9 . Only part of the second locking disk  225   b  can be seen. 
     The invention operates as follows, with the first exemplary embodiment ( FIG. 4  to  FIG. 6 ) being discussed first: 
     Starting from the first position of the locking unit, which position is illustrated in  FIGS. 4 and 4   a  and in which the first flap and the second flap are coupled to form a rigid unit, the locking element  101  is moved relative to the actuating device  112  in such a manner that the guide pin  122  passes through the blind hole  133  of the locking disk  125  and the introductory opening  142 , which is oriented with respect thereto, of the locking plate  128 , with the guide pin  122  being brought in the vicinity of the first, closed end  134  of the blind hole  133  and the second, closed end  144  of the introductory opening  142 , and with the guide pin  122  also having a small amount of play with respect to the second end  144  of the introductory opening  142 . In this first position of the locking unit, the bolt  120  which is designed as a driver is located at the first, open end  131  of the elongated hole  130  and at the first, open end  140  of the bore  139  of the locking plate  128 . 
     During the further course, the motorized drive  118  is actuated in order to rotate the locking disk  125  in the counterclockwise direction about the locking disk axis  127 . In the process, the introductory edge  137  of the locking disk  125  engages over the bolt  120 , which is designed as a driver, and over the first, open end of the blind hole  133 , the bolt  120  coming into contact with the guide surface  136  of the elongated hole  130  of the locking disk  125  during the further course of rotation of the locking disk  125 . Since the elongated hole  130  tapers in the region of the guide surface  136 , the bolt  120  and, together with the latter, the guide pin  122  are essentially pressed along the longitudinal extent of the blind hole  133 , with the play of the guide pin  122  in relation to the first, closed end  134  of the blind hole  133  being eliminated. The object of the introductory edge  137  and of the guide surface  136  is to pull the bolt  120  into the introductory opening  142  of the locking plate  128  until it is in front of the first, open end  140  of the bore  139 . Apart from the action of the guide surface  136  on the bolt  120 , no substantial force is exerted on the latter, and therefore the bolt  120 , which acts as a handle of the lever  123 , still does not permit any rotation of the locking element  101 . The transmission of a torque to the lever  123  is also made difficult by the fact that the locking disk axis  127  is at least approximately aligned with the axis  124  of the guide pin  122 . Owing to the initial small amount of play of the guide pin  122  with respect to the second, closed end  134  of the blind hole  133  of the locking disk  125 , it is ensured that an exact orientation of the axis  124  of the guide pin  122  relative to the locking disk axis  127  is possible. 
     During the further course of the movement of the locking disk  125 , the bolt  120  passes to the second, closed end  132  of the elongated hole  130 . In this intermediate position of the locking unit, an operative connection is produced between the drive  118  and the bolt  120 , which acts as a handle of the lever  123 , on account of which operative connection the bolt  120  is moved and therefore the lever  123  is pivoted in such a manner that the locking element  101 , which is coupled in a rotationally fixed manner to the lever  123 , is rotated in the counterclockwise direction in such a manner that the locking element  101 , which is held in an at least indirectly rotatable manner on the first flap, begins to release the journal  107 , which is fastened at least indirectly to the second flap, and therefore the second flap is no longer coupled to the first flap in the region of the journal  107 . In the process, the first, open end  135  of the blind hole  133  of the locking disk  125  is engaged over by one side of the elongated hole  130 , as a result of which the bolt  120  can no longer exit from the blind hole  133  or the elongated hole  130 . In the intermediate position, when the operative connection between the bolt  120  and the locking disk  125  is produced by the bolt  120  being held at least in an approximately form-fitting manner at the second, closed end  132  of the elongated hole  130  of the locking disk  125 , the guide pin  122  is located at the first, closed end  134  of the blind hole  133  and is accommodated there in an approximately play-free and form-fitting manner such that the axis  124  of the guide pin  122  is aligned with the locking disk axis  127 , and an operative connection between the locking element  101  is brought about exclusively by the bolt  120  being carried along by the locking disk  125  and cannot be interfered with by a force acting on the guide pin  122 . The form-fitting mounting of the guide pin  122  between the closed end  134  of the blind hole  133  of the locking disk  125  and the closed end  144  of the introductory opening  142  of the locking plate  138  fixes the first flap on the support. 
     The bolt  120  is guided by the locking disk  125  along the bore  139  which is arranged in the locking plate  128  and at the first, open end  140  of which the bolt  120  is arranged in the first position and in the intermediate position and at the second, closed end  141  of which the bolt  120  is arranged in the second position of the locking unit. Since the bolt  120  is designed as a handle of the lever  123  of the locking element  101 , in the second position the locking element  101  is rotated in such a manner that the journal  107  is released and the second flap is no longer coupled to the first flap in the region of the journal  107 . However, the bolt  120  is accommodated on the locking plate  128 , which is fastened to the support, in such a manner that the bolt  120  cannot readily pass through the bore  139  in the opposite direction, and therefore the first flap, on which the bolt  120  is at least indirectly rotatably held, is fixed to the support in the region of the bolt  120 . Since the bolt  120  essentially describes a rotation about the locking disk axis  127 , the bore  139  of the locking plate  128 , which bore receives the bolt, is configured as a circular segment, which is in the manner of an elongated hole, of an imaginary circle about the locking disk axis  127 . 
     If the bringing of the first and second flaps from the first into the second position by means of the locking unit has been described above, then, by reversing the direction of rotation of the locking disk  125 , the locking unit can be brought from the second position back into the first position. For this purpose, the locking disk  125  rotates in the counterclockwise direction, and therefore the bolt which is located at the second end  141  of the bore  139  is guided by the wall section  145  of the locking disk  125  through the bore  139  to the first, open end  140  thereof, with the guide pin  122  remaining essentially fixed in position. After the end of the rotation of the locking disk  125 , the bolt  120  is located at the first end  140  of the bore  139  and at the same time at the first, open end  131  of the elongated hole  131  and the second, open end  135  of the elongated hole  133  while the introductory edge  137  of the locking disk  125  has released the first end  140  of the bore  139  to an extent such that the bolt  120  and the guide pin  122  can be brought out of engagement with the locking disk  125  and with the locking plate  128 . 
     The second exemplary embodiment ( FIGS. 7 to 9 ) differs from the first exemplary embodiment ( FIG. 4  to  FIG. 6 ) essentially in that the locking element  201  has a longitudinally displaceable slide  250  and no lever  123  to be actuated by rotation, and a locking element  101 . 
     Starting from the first position of the locking unit, which position is illustrated in  FIG. 7  and in which the first flap and the second flap are coupled to form a unit, the pin  253  is brought to the first, open end  240  of the bore  239  of the locking plate  228   a  or  228   b , in which position the pin  253  is likewise located at the first, open end  231  of the elongated hole  230 . In this position, the slide  250  passes both through the receptacle  251 , which is assigned to the first flap, and through the guide section  252 , which is assigned to the second flap, and thereby couples the two flaps to each other. If the locking disk  225   a ,  225   b  is now actuated, the introductory edge  237  engages over the pin  253  of the slide  250 , with the elongated hole  230  being moved relative to the initially essentially positionally fixed pin  253  in such a manner that the pin  253  comes into contact with the guide surface  236  of the elongated hole  230 , and therefore the pin  253  is pulled downward somewhat into the elongated hole  230 . A lateral force which is required for displacing the slide  250  is initially not yet exerted on the pin  253  and therefore on the slide  250  ( FIG. 7 ). 
     During the further course of the movement of the elongated hole  230 , the pin  253  is received at the second, closed end  232  thereof, and therefore an operative connection is then produced between the drive  218 , which drives the locking disk  225   a ,  225   b , and the slide  250 , which is connected fixedly to the pin  253 . Starting from the intermediate position, in which the pin  253  is received at the second end  232  of the elongated hole  230 , the pin  253  is guided by the elongated hole  230  and passes through the bore  239  in the locking plate  228   a ,  228   b . In the intermediate position, the introductory edge  237  engages over the first, open end  240  of the bore  239  of the locking plate  228   a ,  228   b , and therefore the pin  253  can no longer readily be brought back into the starting position. In particular, the first flap and the second flap are still fastened to each other in the intermediate position, but the two flaps are jointly fixed at least temporarily to the support via the pin  253 . 
     The further movement of the pin  253  on account of the elongated hole  230  which guides it is limited by the pin  253  passing to the second end  256  of the guide  254 . In this second position, the slide  250  has emerged from the guide section  252 , which is assigned to the second flap, and releases the second flap with respect to the first flap in such a manner that the second flap can rotate about the axis  258 . The first flap is fixed in the region of the pin  253  by the slide  250  which is fixed to the support and is assigned to the first flap via the receptacle  251 . 
     Also in the second exemplary embodiment, by reversing the direction of rotation of the locking disk  225   a ,  225   b , the pin  253  is moved out of the bore  239  of the locking plate  228   a ,  228   b  in order to bring the two flaps back from the second position into the first position by means of the locking device. 
     In the two exemplary embodiments described above, the locking disks  125  and  225   a  and  225   b  were each mounted rotatably on the support. However, it has to be understood that another type of mounting, in particular a longitudinally displaceable mounting of locking disks, can be provided, especially if the locking element is mounted in a longitudinally displaceable manner. 
     In the case of the two exemplary embodiments described above, the elongated hole  130 ,  230  of the locking disk  125  or  225   a  and  225   b  was in each case a cutout, which is open at one end, of an essentially ovally curved contour. It has to be understood that an elongated hole can also have a different contour. If, for example, in the case of the second exemplary embodiment, a vertically displaceable locking disk is provided, the elongated hole can have a triangular outline, for example in the form of a right-angled triangle, in which, in the first position, the driver is accommodated at the first edge between one of the legs and the hypotenuse, and, over the further course of the longitudinal movement of the locking disk, is guided along the hypotenuse of the triangle and, in the second position, is accommodated at the second edge between the other leg and the hypotenuse. 
     It furthermore has to be understood that, for a motor vehicle, the bodywork of which corresponds to the above-described support, a respective locking unit, as described above, can be provided on each side in a mirror-inverted manner with respect to a longitudinal center plane of the bodywork. 
     In the exemplary embodiments described above, in addition to the driven locking disk, a locking plate fastened to the support was provided, the locking plate receiving the driver in the bore. The locking plate here has the task of absorbing the forces in effect during the guidance of the driver. It has to be understood that a locking plate may also be omitted. 
     In particular, it is possible to guide the driver only by means of a driven locking disk. Specifically, the locking disk can be spring-mounted for this purpose on the support in the first position, with the driver initially pressing down the introductory edge of the locking disk, after which the locking disk springs back and, in the process, engages with the introductory edge over the driver in order to permit further secure guidance of the driver in the elongated hole. For the guidance of the driver, a fixed support of the locking disk on the support is required, for which purpose the initial, resilient mounting of the locking disk can be removed as soon as the driver is accommodated in the elongated hole. To switch between the resilient mounting and the fixed support of the locking disk on the support, a sensor mechanism can be provided which detects when the driver enters the elongated hole of the locking disk. 
     It furthermore has to be understood that the locking unit can comprise a sensor which determines whether the driver is located at the open end of the elongated hole, and therefore the locking disk can be set into motion. Such a sensor can be coupled to the drive of the locking disk in such a manner that the drive only sets the locking disk into motion when the sensor detects that the driver has reached a suitable position with respect to the elongated hole of the locking disk. It furthermore has to be understood that the same sensor, or else a further sensor, follows the movement of the driver and detects when it reaches the second position, in order to be able to output a signal that the locking of the flaps has been carried out correctly.