Abstract:
A charging device for an electric vehicle, which charging device can be protected against unauthorized access in a particularly reliable manner. The charging device for an electric vehicle has a bolt for locking a connection between the charging device and a further charging device. If the charging device is mechanically connected to a further charging device for charging purposes, this mechanical connection is then locked by a corresponding end of the bolt being moved into a retaining opening in the further charging device. A retaining opening of this kind can, for example, be damaged by a broken web which serves for locking such that locking is no longer possible. Therefore, a device is provided which can prevent movement of the bolt in the direction of a locking position when the retaining opening is damaged in this way. A locking arrangement which is damaged in the above manner therefore fundamentally does not remain unnoticed. Charging therefore preferably requires sufficiently undamaged, correct locking of the two charging devices involved.

Description:
RELATED APPLICATION DATA 
     This application is a continuation of U.S. application Ser. No. 14/004,207 filed Sep. 10, 2013 which is a National Phase of PCT/DE2011/001952 filed Nov. 8, 2011 which claims priority of German Application No. 10 2010 044 138.4 filed Nov. 18, 2010, all of which are hereby incorporated herein by reference in their entireties. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to a charging device of an electric vehicle with the features of the preamble of claim  1 . 
     BACKGROUND 
     An electric vehicle is a vehicle which is propelled by an electric motor. The electric motor draws its power from a battery which is housed in the electric vehicle. This battery needs to be charged again after a discharge. For charging the battery, a charging device is used in the sense of the present invention. The charging device can be a part of the electric vehicle or a part of a charging station. If the battery of an electric vehicle is to be charged, the charging device of a charging station is connected mechanically and electrically with the charging device of an electric vehicle. Then, the battery can be charged by means of an electric current supplied by the charging station. 
     To avoid an unauthorized access during the charging of a battery of an electric vehicle, the mechanical and electrical connection between two charging devices must be locked during this time. A suitable locking device which is able to protect against unauthorized removal of the charging plug is disclosed in the publication DE 196 42 687 A1. For this purpose, this locking device comprises a control element for adjusting a bolt for the purpose of locking the charging plug. In order to provide a locking action, the bolt passes into a retaining opening. 
     SUMMARY OF THE INVENTION 
     The present invention provides a charging device for an electric vehicle that can very reliably protect against unauthorized access. 
     To this end, a charging device comprises the features of claim  1 . Advantageous embodiments are disclosed in the dependent claims. 
     The charging device for an electric vehicle comprises a bolt for locking a connection between the charging device and another charging device. If the claimed charging device is connected mechanically to another charging device for the purpose of charging, this mechanical connection is then locked by moving an appropriate end of the bolt into a retaining opening of the other charging device. Such a retaining opening may be damaged, for example, by a bar (hereinafter referred to as “locking bar”), that serves for the locking and has been broken off, to such an extent that a locking is no longer possible. For this reason, a device is provided that is able to prevent the bolt from moving in the direction of the locking position if the retaining opening is damaged in such a manner. As a consequence, a lock damaged in the aforementioned manner will definitely not go unnoticed. Essentially, charging desirably requires a sufficiently undamaged, proper locking of the two charging devices involved 
     It is not necessary or desired that just any damage to the retaining opening will result in preventing a movement of the bolt in the direction of the locking position. Instead, it is desirable that at least such damage to the retaining opening that renders a locking of a mechanical connection between two charging devices no longer possible would result in preventing the movement of the bolt in the direction of the locking position. 
     The device may comprise an electric switch or micro-switch that is actuated by the aforementioned locking bar of the retaining opening when two charging devices are mechanically interconnected for a charging process. If the locking bar was broken off, the actuation of the switch or micro switch does not occur. In this case, the missing electrical signal has the specific consequence that any subsequent action required for the charging process is interrupted, and a charging process can therefore not take place. Therefore, the actuation of the microswitch is a prerequisite for making the charging of the battery of the electric vehicle possible, or at least for a locking process to occur. 
     In one embodiment, the charging device comprises a lever which is moved by the aforementioned locking bar of the retaining opening from a starting position into an end position when the claimed charging device is mechanically connected with another charging device. In addition, the charging device is designed so that locking is only possible when the lever has reached its end position. In the end position, the lever actuates an electrical switch, for example. Only the electrical signal triggered in this way will then permit or initiate, for example, the locking of the two charging device. The locking, in turn, is then a preferable prerequisite for the charging to commence. 
     In one embodiment of the invention, the aforesaid lever in the starting position mechanically blocks the bolt so that it cannot move into its locking position. Only by moving the lever to its end position is the blockade lifted, making the locking possible. This embodiment represents a purely mechanical solution that is capable of preventing the movement of the bolt towards the locking position in the case of relevant damage to the retaining opening. The dependence on electrical equipment is reduced accordingly and the energy required for a mechanical connection of two charging devices is kept correspondingly low. Minimizing the energy required for a mechanical connection is particularly advantageous if the claimed charging device is a part of the electric vehicle and should receive power from the battery of the electric vehicle. Particularly in this case, especially economical use must be made of the resources of the discharged battery, which is made possible by this embodiment. 
     In one embodiment of the invention, the aforementioned lever has an oblong hole into which extends a pin projecting from the bolt. The extension of the oblong hole is such that the elongated hole blocks a locking process in the starting position of the lever, and enables the locking process when the lever has been moved into its end position. In particular, the elongated hole extends at a suitable angle for this reason. The first area on one side of the angle will then have a blocking effect. The adjacent area allows the locking. 
     In one embodiment of the invention, the lever comprises a laterally projecting shield which shields the access to the retaining opening when the lever is in its starting position. When the lever is pivoted to its end position, or moved to the end position in some different way, the shield will also move away in such a way that the access to the retaining opening is unblocked. Only after such unblocking can the bolt be moved to its locking position. 
     In one form of embodiment, the lever has a lug which is always located within the plane of movement of the lever. In the starting position, the lug is able to block the access to the retaining opening, making it impossible for the bolt to lock. Only when the lever and hence the lug has been moved away, and the lever is then in its end position, can the bolt be moved into its locking position. However, it is also possible that, beginning from the starting position, only an initial rotary movement of the lever has the consequence that the lug, for example, is positioned in front of a laterally protruding pin of the bolt. If, for example, a micro switch or key switch has registered the initial rotary movement, then an ensuing signal can be used as a control for the start of movement of the bolt from its non-locking position in the direction of the locking position. The aforementioned pin protruding from the locking bolt will then continue to rotate the lever until the end position is reached. Further rotation can in turn be detected by the micro-switch mentioned above, that is thereby able to detect, at the same time, the attainment of the locking position and to stop, for example, a further movement or further action of a force on the bolt. 
     In one embodiment, the bolt is hook-shaped, for example L-shaped, and comprises, in the case of an L-shape, a long and a short flank. Both flanks enclose at least approximately a right angle. One end of the hook, for example the short flank in the case of the L-shape, can be moved into the retaining opening for locking. At least close to the other end of the hook, the bolt can be pivotably supported in order to enable the bolt to move between its locking position and its non-locking position. 
     Preferably, an electrical drive system acts on the aforementioned pivotably mounted end of the hook in order to move the bolt from its locking position to its non-locking position. This movement is performed after a charging of the battery of an electric vehicle in order to disconnect the two involved charging devices. Even the battery of the electric vehicle can then easily provide sufficient power for such a bolt movement so that a convenient electric drive system is then easily possible. 
     The present invention also includes the case that the bolt can be moved back and forth between the locking position and the non-locking position by an electric drive system. 
     In one embodiment of the invention, the lever comprises a passage for the bolt in the end position. If the lever is in its starting position, the passage is placed differently in spatial terms, so that the bolt cannot be moved into the retaining opening. This embodiment requires a relatively small space. 
     In one embodiment of the invention, the charging device comprises a mechanism which is able to move the bolt from its non-locking position to its locking position. This can be a pre-tensioned spring that pushes or pulls the bolt in the direction of the locking position. This embodiment further contributes to the feature that immediately before recharging no current of the battery of the electric vehicle needs to be consumed, not even when the charging device is part of the electric vehicle. 
     In one embodiment of the invention, there are one or more electrical microswitches or electrical switches with which the position of the lever and/or the bolt can be determined. Dependent thereon, electric drive systems for the lever and/or for the bolt can be controlled. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Below, the invention is explained with reference to Figures. 
         FIG. 1  is a cross-sectional view of a charging device with two microswitches. 
         FIG. 2  is a cross-sectional view of a charging device with pivoting lever and shield. 
         FIG. 3  is a cross-sectional view of a charging device with pivoting lever and passage in the lever. 
         FIGS. 4A and 4B  are cross-sectional views of a charging device with lever and lug. 
         FIGS. 5A and 5B  are cross-sectional views of a charging device with lever and elongated hole. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a charging device  1  of an electric vehicle that is to be connected with a further loading device  2  of a loading station. The charging device  1  comprises a housing  3  into which the housing  4  of the loading device  2  can be inserted. At the base of the housing  3 , the charging device  1  comprises a number of electrical contact pins  5  which serve for the charging with DC and/or AC voltage. The electrical contact pins  5  are either connected permanently with the housing  3  or can, for example, be moved by an electric drive system along their longitudinal axis for the establishment of an electrical connection. The loading device  2  comprises corresponding electrical contact sockets  6 , into which the electrical contact pins  5  are moved during a mechanical connection or following the locking of such a mechanical connection into such a lock, in order to thereby produce an electrical connection between the two charging devices  1  and  2 . The charging device  1  comprises a bolt  7  that is mounted laterally on the outside of the housing  3 . The associated housing wall  3  has an opening  8  for the bolt  7  through which the bolt  7  can be moved. The loading device  2  comprises, laterally in the housing  4 , a retaining opening  9 . If the second loading device  2  is inserted into the housing  3  of the charging device  1 , the bolt  7  can be moved through the opening  8  into the retaining opening  9 . The two devices  1  and  2  are then both connected mechanically to each other and are also locked. For the locking, a locking bar  10  is responsible, among other things, that borders the retaining opening  9  on the side that faces the base of the housing  3 . At the base of the housing  3  of the charging device  1 , a micro-switch  11  is located having a key  12  which extends into the interior of the housing  3 . If the second charging device  2  is inserted into the housing  3  of the charging device  1 , the locking bar  10  will eventually reach the key  12 , pressing it into the micro-switch  11 . In this way, an electrical contact is triggered. The electrical contact causes the bolt  7  to be moved from its non-locking position into the locking position. Therefore, following that, the mechanical connection between the two charging devices  1  and  2  has been locked. 
     If the locking bar  10  has been broken off, the key  12  of the micro-switch  11  can no longer be actuated. This prevents the bolt  7  from being moved into its locking position. 
     Preferably, the electrical contact pins  5  are mobile and can be moved, with their contacting ends, from the base of the housing  3  into the interior for making an electrical connection. This movement takes place specifically under the control of an electric drive system, and not until the bolt  7  has been moved into its locking position. For this purpose, a further micro-switch  13  may be provided that is able to detect the position of the bolt  7 . If, for example, the bolt  7  has been moved from its non-locking position to its locking position, a key  14 , for example, is released that causes an electrical impulse. This electrical pulse then causes the electrical contact pins  5  to be moved in the direction of the electrical contact sockets  6 , and then into these sockets. Once the electrical contact pins  5  have assumed their final position in the electrical contact sockets  6 , an electrical connection between the electrical contact elements  5  and  6  has been established. Thereafter, charging may take place. 
     If the electrical contact pins  5  are immobile, then the micro-switch  13  can be used for making charging possible, with electronic control, only after the bolt  7  has been moved to its locking position. If this is not the case, charging is blocked, for example, electronically. 
     The micro-switch  11  of  FIG. 1  may also be located laterally on the housing  3 , adjacent to the opening  8  as well as adjacent to the base of the housing  3  in order to be able to detect the presence of the bar  10 . Here, again, the key  12  extends into the housing  3 . 
       FIG. 2  shows a further embodiment of the present invention. The housing  4  of a loading device  2  is inserted into the housing  3  of a charging device  1 . Here, too, as in the case of the  FIG. 1 , the housing  4  is not yet fully inserted. Instead of a micro-switch  11 , the charging device  1  comprises a lever  15 , which in  FIG. 2  is shown in its starting position. A shield  16  protrudes from the lever  15  in the plane of the paper. The shield  16  bars the access to the opening or passage  8  of the housing  3 . In the case of  FIG. 2 , a bolt  7  is located partially behind the lever  15 . The shield  16  prevents the bolt  7  from being moved through the opening  8 . The lever  15  can be rotated or pivoted around the axis  17 . The lever  15  comprises a projection  18  that extends into the housing  3 . The projection  18  is placed so that it can be engaged and moved by the locking bar  10 . In the starting position of the lever  18 , the projection  18  extends laterally into the interior of the housing  3 , as shown. Preferably, the projection  18  is dimensioned so that, in the end position of the lever, it is practically completely pivoted out laterally from the interior, and will then contact the housing  4  laterally, and will no longer contact the head end of the housing  4 , as shown in  FIG. 2 . In this case, excessive space requirements with respect to depth for the charging device  1  are avoided. If the loading device  2  is moved fully into the housing  3  of the charging device  1 , the lever  15  is pivoted from the shown starting position to the end position. Once the lever  15  has reached its end position, the shield  16  has been pivoted away from the opening  8 . It is then possible to move the bolt  7  through the opening  8  and into the retaining opening  9  so as to lock the two devices  1  and  2  together. 
     If the locking bar  10  has been broken off, the projection  18  and therefore also the lever  15  is not pivoted in the direction of the end position. The shield  16  will then permanently prevent the bolt  7  from being moved into its locking position. 
     The bolt  7  can be configured as a spindle that can be moved, but cannot be rotated. There will then be a spindle nut  19  that can be rotated but can not be moved. If the spindle nut  19  is rotated by means of an electric drive system  20  that comprises, for example, an electric motor and a pinion or gear wheel, the bolt  7  is moved accordingly between its non-locking position and its locking position. 
     On the other hand, a micro-switch  13  may be provided which can be actuated by a widened end  21  of the bolt  7  when the bolt  7  has reached its locking position. Consequently, the position of the bolt  7  can be detected by means of the micro-switch  13 . Preferably, a charging process can be started only when it has been determined in this way that the bolt  7  is in its locking position. 
       FIG. 2  shows the case where the contact pins  5  are not yet in a position to be electrically contacted with the contact sockets  6 . These electrical contact pins  5  may be moved in the direction of electrical contact sockets  6  and into the latter once the mechanical connection between the two charging devices  1  and  2  has been locked. The micro-switch  13  may be used for causing such a movement of the electrical contact pins  5  into the contacting position as soon as the bolt  7  has been moved to its locking position. 
     The lever  15  may be pre-tensioned by a spring (not shown) in the direction of its starting position. If the loading device  2  is pulled out of the housing  3  of the charging device  1  after charging is completed and after unlocking has occurred, the lever  15  returns to its initial position shown in  FIG. 2  due to the pre-tensioned spring. 
       FIG. 3  illustrates a further embodiment of the invention. It shows a top view of the retaining opening  9  in the housing  4  of the other charging device. The charging device  1  also comprises a lever  15  that is located in the starting position and prevents the bolt  7  (shown in cross-section) from being moved through an opening  3  of the lever  15 . The lever  15  that is mounted so that it is able to pivot around the axis  17  comprises a pin  22  that extends into the interior of the housing  3 . If the housing  4  of the loading device  2  is inserted into the housing  3  of the of the charging device  1 , the housing  4  eventually reaches this protruding pin  22 , and then pivots the pin together with the lever  15  from its depicted starting position into the end position. When the lever  15  has reached its end position, the passage  23  in the lever  15  is aligned with an opening that may be present in the housing  3  as well as with the retaining opening  9 . The bolt  7  can then be moved through the respective openings into the retaining opening  9  for locking the mechanical connection. 
     This embodiment requires especially little space. The lever  15 , in turn, can be moved by means of a pre-tensioned spring (not shown) back from the end position into the starting position as soon as the housing  4  of the loading device is pulled out of housing  3  again. 
     A particularly robust embodiment is illustrated in  FIGS. 4 a  and 4 b   . This embodiment comprises a micro-switch  24  that is able to detect the position of the lever  15 .  FIG. 4 a    shows the starting position of the lever  15 . If the additional loading device  2  is inserted into the housing  3  of the first charging device  1 , the bar  10  eventually engages one end  25  of the lever  15 , thus rotating the lever  15  into the end position, which is shown in  FIG. 4 b   . In the end position, there is a lug  26  of the lever  15 , which in this end position, but not in the starting position, can be engaged by a laterally projecting pin  27  of the bolt  7 . When, initiated by the micro-switch  24 , the bolt  7  is now moved into its locking position, the pin  27  engages the projection  26  and rotates the lever  15  beyond its final position. The interaction between the lever  15  and the micro-switch  24  is preferably configured so that this additional rotation can also be registered. Accordingly, reaching of the end position as well as the attainment of the locking position by the bolt  7  is detected with only one micro-switch  24 . 
     If the bar  10  has been broken off, the lever  15  cannot be pivoted to its end position. An associated detection signal of the microswitch  24  will then be absent. In the absence of such a detection signal, a movement of the bolt  7  into its locking position will not take place, and/or the charging of the battery of an electric vehicle is electronically prevented. 
       FIGS. 5 a  and 5 b    show a further embodiment of the invention. The bolt  7  is designed L-shaped and can be pivoted around an axis  28 . The bolt  7  comprises a laterally projecting pin  29  which extends into an elongated hole  30 , extending in an angular shape, of the lever  15 .  FIG. 5 a    shows the lever  15  in its starting position. One end of the lever  15  extends into the interior of the housing  3  of the charging device  1 . The pin  29  is then located in an area of the elongated hole  30  that prevents the bolt  7  from being moved, for example by means of an appropriately pre-tensioned spring, through the opening  8  in the side wall of housing  3 . When the lever  15  is moved by the locking bar  10  from the starting position shown in  FIG. 5 a    into the end position shown in  FIG. 5 b   , the pin  29  enters an area of the elongated hole  30  that permits a movement of the bolt  7  through the opening  8  into the retaining opening  9 , as shown in  FIG. 5 b   . By means of a micro-switch  13 , the position of the bolt  7  can be detected in order to permit, for example in response thereto, a charging process. The bolt  7  is moved by means of an electrical drive system out of its locking position, following a charging process. For this purpose, a motor  31  is provided that drives a worm gear  32 . The worm gear  32  rotates a pinion  33  which is provided with a projection  34 . The projection  34  is able to pivot an end  35  of the bolt  7  in such a way that the bolt  7  can thereby be moved from its locking position shown in  FIG. 5 b    into its non-locking position according to  FIG. 5   a.    
     LIST OF REFERENCE NUMBERS 
     
         
         
           
               1 : charging device of an electric vehicle, 
               2 : loading device of a charging station 
               3 : housing 
               4 : housing 
               5 : electrical contact pin 
               6 : electrical contact socket 
               7 : bolt 
               8 : bolt opening 
               9 : retaining opening 
               10 : locking bar 
               11 : micro-switch 
               12 : key 
               13 : micro-switch 
               14 : key 
               15 : lever 
               16 : shield 
               17 : axis 
               18 : projection 
               19 : spindle nut 
               20 : electric drive system 
               21 : widened bolt end 
               22 : bolt 
               23 : passage 
               24 : micro-switch 
               25 : end of the lever 
               26 : lever lug 
               27 : locking pin 
               28 : axis 
               29 : laterally projecting pin 
               30 : elongated hole 
               31 : motor 
               32 : worm gear 
               33 : pinion 
               34 : projection 
               35 : end of bolt