Abstract:
The invention relates to a motor vehicle with a roof or roof section which may be placed below a cover piece in the rear section of the vehicle, whereby the cover piece can be opened to provide a loading opening for luggage or a through opening for the roof. The cover piece is retained by at least one displacement mechanism in the vehicle, embodied such that the displacement mechanism, on at least one vehicle side, comprises a movement with only one degree of freedom for both opening directions of the cover piece.

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application is the United States national phase application of PCT/DE2006/000156, filed Feb. 2, 2006, which claims priority to German Patent Application No. DE102005006272.5, filed Feb. 10, 2005, the entire content of each application is incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The invention relates to a motor vehicle comprising a roof or roof portion which can be stowed underneath a cover part, in particular to a convertible vehicle, wherein the cover part is capable of opening in two different movement procedures. 
     BACKGROUND OF THE INVENTION 
     A convertible vehicle is known from DE 44 45 944 C1 which provides a cover part to be opened in two oppositely directed movement procedures to provide a passage opening for the roof, on the one hand, and to provide a loading opening for baggage, on the other hand, depending on the direction of opening. The cover part is attached to a rearward auxiliary frame which in turn pivots around an axis close to the tail to realize a first direction of movement and remains unpivoted to realize a second direction of movement, while multijoints attached to the auxiliary frame open. A construction of this type requires a high construction effort with a plurality of pivot points. The cover part moreover pivots around an axis associated with its rear lock on the release of the passage openings for the roof, which restricts the design options of the vehicle tail. 
     It is the underlying problem of the invention to improve a motor vehicle of the named kind with respect to the opening mechanism of its cover part. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the invention, a motor vehicle includes an improved convertible roof design, in which a roof part is stowable in a rearward vehicle portion beneath a cover part, wherein the cover part can be selectively opened in one direction to provide a loading opening for baggage or in another direction to provide a passage opening for the roof part. The movement is provided by at least one movement mechanism in the vehicle, wherein the movement mechanism includes a transmission at least at one vehicle side having only one degree of freedom for both directions of opening of the cover part. By this arrangement, both oppositely directed opening movements of the cover part can thus be effected using the same transmission. No separate joint arrangements are required to form the passage opening for the roof, on the one hand, and to form the loading opening for baggage, on the other hand. The total construction is thus substantially simplified and the space requirements in the vehicle and the number of pivot points, as well as the control effort are minimized. Neither an auxiliary frame nor any other blocking of some of the joints required for one of the directions of movement is necessary to reduce the number of the degrees of freedom of the transmission. 
     Provided a central drive member for the movement out of the closed position can be pivoted out in two directions, a single drive can be used, for example an electrically movable spindle, for both directions of opening without switching over. The control of the movement is thereby very simple. The only one rotation possibility in two directions simplifies the total construction. 
     When the drive member can be rotated around a rotary axle disposed transversely to the vehicle, the drive can be arranged, for example, vertically behind the rear wheelhouse in a space-saving manner and while utilizing body spaces already present. 
     A formation of a central triangular member which is held rotatably on the rotary axle and which carries spaced apart therefrom two joints for two drive members of the cover part movement can, on a deflection out of the neutral position, exert a shear force on both drive members simultaneously and achieves a fast and effective movement of the cover part in the one or the other direction. 
     It is moreover particularly advantageously possible that drive members pivoting on an opening of the cover at least nearly intersect and that therefore an external introduction of force onto these drive members, for instance by a violent attempt to open the cover part, does not exert any torque around the rotary axle and the closed position is, thereby, secured. The number of locks can thus be minimized. 
     Provided that the transmission is deflected at one extreme angular position when the cover part is opened to form the passage opening for the roof and is deflected at another extreme angular position when the cover part is opened to form the loading opening for baggage, the opening angles can be bounded by adjustable abutments and thus be adjustable. A drive can then only travel in one direction between both different open positions, with the neutral position with a closed cover part being able to represent a simple intermediate position of the drive. 
     A connection of the cover part in every direction of movement to the body only via the transmission or transmissions makes further retaining parts such as auxiliary frames or the like completely superfluous. 
     A particular advantage can be achieved it during the opening to form the passage opening for the roof, the cover part can be raised overall such that its rear end does not fall below its height when closed. A tail design, in particular a bumper, used with a closed version of the vehicle type can be used unchanged, without a recess having to be provided there for the lowering rear part of the cover part. This saves substantial conversion costs. 
     The joints of the transmission can be of different kinds and be formed, for instance, as pivot joints, sliding joints or cam joints. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
         FIG. 1  is a lateral schematic view of a tail region of a convertible vehicle in accordance with the invention in a closed position of the cover part; 
         FIG. 2  is a similar view of only the cover part and of the associated movement mechanism as in  FIG. 1  during the starting opening of the cover part for the release of a loading opening for baggage; 
         FIG. 3  is a similar view to  FIG. 2  with a further progressing opening of the roof part; 
         FIG. 4  is a similar view to  FIG. 3  with a completely open cover part for the release of the loading opening for baggage; 
         FIG. 5  is a similar view of the tail region as in  FIG. 2 , but with a starting opening of the cover part in the opposite direction thereto for the release of the passage opening for the roof; 
         FIG. 6  is a similar view of the cover part and of the associated movement mechanism as in  FIG. 5  on a further progressing opening of the cover part for the release of the passage opening for the roof; 
         FIG. 7  is a similar view to  FIG. 6  with a further progressing opening of the cover part for the release of the passage opening for the roof; and 
         FIG. 8  is a similar representation of the cover part in a fully open position for the release of the passage opening for the roof. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In  FIG. 1 , a tail region  2  of a motor vehicle designated in total by  1  is shown with a roof  3  which is capable of at least partially opening or capable of opening completely. It can partly or fully include rigid parts or also be provided with a flexible top continuously outside a rear window. The roof  3  can be stowed in a top storage well (not shown) beneath a moving decklid or cover part  5  in the body  4  for its opening. 
     The cover part  5  can be opened in two oppositely directed movements from a closed position in accordance with  FIG. 1 . 
     To permit opening of the cover part  5  in one direction to form a loading opening  6  for baggage, the cover part  5  can be pivoted in the direction of the arrow  7 , as shown in  FIGS. 2-4 , and can be pivoted back opposite the arrow  7  for closing the cover part  5 . 
     Furthermore, the cover part  5  can be opened in an opposite direction of movement to form a passage opening  9  for the roof  3  in the direction of the arrow  8 , as shown in  FIGS. 5-8 , and can be closed against this direction. 
     To make these two opening and closing movements possible, the cover part  5  is movably held at least at one longitudinal vehicle side, usually at both, at the body  4  in each case at a movement mechanism generally indicated at B via a transmission having only one transmission degree of freedom. The movement mechanism B can be inserted in modular form into the body  4  together with the cover part  5  in the assembly process. 
     In the closed state, the cover part  5  is additionally held at a tail-side lock  10  into which it can automatically latch on closing and which is, for example, remotely triggerable electrically for opening. 
     The transmission can be driven by a main member  11  which is made as a triangular member and is movably held on an axle  12  extending transversely to the vehicle and having only one rotational degree of freedom. Two drive members  13 ,  14  are pivotably movably arranged spaced from the axle  12  at the triangular member  11  and cross the rotary axle  12  at a dead-center position with a closed cover part  5  so that a pulling force onto one of these drive members  13 ,  14  by an attempt to open the cover part  15  externally cannot lead to a resulting torque of the main member  11  around the axle  12 . Enhanced security of the corner part  5  in the closed state is hereby achieved. No further lock is therefore needed. Optionally, at least one tail cover lock  10  can be provided for the compensation of any tolerances and elasticities in the material. 
     To open the cover part  5  from the closed position ( FIG. 1 ) in the first direction of movement in the direction of the arrow  7  to form the loading opening  6  for baggage ( FIG. 2  to  FIG. 4 ), the triangular member  11  is pivoted in the direction of the arrow  15  around the axle  12 . The member  11  is pivoted by a drive member (not shown), for example a hydraulic cylinder, an electrically driven spindle, a belt drive or another drive member to be arranged easily in the body depending on the space conditions so that the drive members  13  and  14  are moved out of the dead-center position. A sliding force is exerted onto the positioning levers  17 ,  18  so that they are pivoted around their joints  21 ,  22  fixed to the body with different transmissions in the direction of the arrows  19 ,  20 . The front positioning lever  18  passes through a larger angular range in this process. A deflecting intermediate lever  23  connects the front positioning lever  18  to the linkage  24  further to the rear than the positioning lever  17  is connected to the cover part  5  by linkage  25 . Therefore, the rear end of the cover is raised more than its front end ( FIG. 4 ). 
     At the end of the rotary movement in the direction of the arrow  15 , an extreme angular position is reached at which the triangular member  11  contacts an adjustable abutment  26  which bounds the opening angle of the cover part  5   FIG. 4 ). 
     In contrast, to open the cover part  5  from the neutral position ( FIG. 1 ) in the second direction (arrow  8 ) to open the passage opening  9  for the roof  3  ( FIG. 5  to  FIG. 8 ), the triangular member  11  is rotated out of its neutral position ( FIG. 1 ) in the opposite direction to the first cover part opening described above. The member  11  is rotated in the direction of the arrow  16 , with the drive members  13  and  14  being taken along. The positioning levers  17 ,  18  acted on by the drive members  13 ,  14  are, in turn, rotated in the direction of the arrows  19 ,  20 . However, this time, due to the changed direction of rotation of the triangular member  11 , the different transmissions act such that the cover part  5  is first raised almost parallel and at the end of its movement (transition from  FIG. 7  to  FIG. 8 ) the intermediate lever  23  kinks with respect to the positioning lever  18  and thus the rear end of the cover part is transposed downwardly. 
     At the end of the rotary movement in the direction of the arrow  16 , an extreme angular position is reached opposite to the above movement at which the triangular member  11  contacts an adjustable abutment  27  which bounds the opening angle of the cover part  5  ( FIG. 8 ). 
     The transmission here includes, for example, a total of ten joints, with only the two joints  21 ,  22  as well as the central pivot joint  12  being arranged fixed to the body and the joints  24 ,  25  being arranged fixed to the cover part  5 . All the joints are in co-movement during the movement of the cover part; no joint is blocked, for example by being held fast in a lock. 
     A particular advantage is the fact that the rear end  28  of the cover part  5  also does not fall below its height when it is closed, during an initial raising movement of the cover part  5  toward the rearwardly tilted release position of the passage opening  9  for the roof  3  so that the notch  29  into the bumper drawn here is not necessary. The bumper or other body part can rather be formed in the same way as with a vehicle with a closed structure, which saves substantial costs. 
     The cover part  5  is only held to the body  4  via the transmission or transmissions in every phase of the movement so that further linkage parts can be omitted and the design can therefore be performed simply and with a low weight. The tail lock  10  only serves for latching and does not have any carrying function; the cover part  5  is in particular not rotated around it. 
     The cover part  5  is movable so as to apply a downward pressure with a high force during its closing. Thus, a good sealing property of a seal extending beneath the cover part  5  is thereby achieved. 
     Overall, the transmission encompassed by the movement mechanism  9  has only a mechanically determined possibility of the movement procedure of all joints so that the transmission has only one degree of freedom for every opening or closing position of the cover part  5 . 
     The invention has been described in an illustrative manner. It is, therefore, to be understood that the terminology used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the invention are possible in light of the above teachings. Thus, within the scope of the appended claims, the invention may be practiced other than as specifically described.