Abstract:
The invention proposes a transporting apparatus for transporting single or double workpieces through processing stations of presses, in which apparatus up to 9 degrees of freedom are integrated in the transporting system. Necessary changes in position for, for example, feeding into dies can take place directly by way of the transporting apparatus. It is possible to dispense with intermediate set-down locations or orienting stations.

Description:
FIELD OF THE INVENTION 
   The invention relates to a press line or multi-stage press for large components, having a transporting apparatus for transporting workpieces. 
   BACKGROUND OF THE INVENTION 
   In a press, press line or multi-stage press for large components, transfer apparatuses are provided for transporting workpieces into the processing stages. In recent systems according to EP 0 672 480 B1 or EP 0 693 334 A1, the transporting operation between individual processing stations takes place individually by individual transporting apparatuses, which allow, in particular, a high flexibility of the capacity for movement of the workpiece transportation between individual processing stages. By means of such a drive, which is fully independent of the central drive of the press, it is possible to optimize the transportation of the workpiece in a number of degrees of freedom, in particular in relatively large press installations. For this purpose, you are referred to EP 0 672 480 or EP 0 693 334. By way of example, carrying rails, on which carriages with dedicated drive travel, are provided over the entire press length. For accommodating the workpieces, use is made of crossmembers which are provided with retaining means and are each fastened on 2 opposite carriages. In the most straightforward embodiment, 2 transporting movements are provided for transferring the workpieces, to be precise a vertical movement and a horizontal movement. The vertical movement serves for removing the workpiece from the bottom die part or depositing the workpiece in the same, while the horizontal movement provides the actual transporting step. This transporting step can take place from one press into the following press or, in the case of a multi-stage press for large components, from one forming station into the next. 
   However, it is usually the case that the workpieces and/or dies are not of such straightforward configuration as to allow transportation in biaxial operation. By way of example, in the case of passenger-vehicle doors, the latter, in the first forming stage, are drawn from a common blank in order then, following a cutting operation, to run, each as separate workpieces, through the processing stages together. In order to avoid more expensive and complicated dies, it is necessary for the workpiece to be brought into an optimum processing position during the transfer operation. This change in position is usually carried out by way of intermediate set-down locations or orienting stations. 
   Such an intermediate set-down location, both for single and for double components, is disclosed by EP 0 383 168 B1 or DE 196 51 934 A1. Of particular note are the 5 degrees of freedom which can be used for changing the position of workpieces of complex configuration. It is thus possible, if required, for the position of the workpiece to be manipulated in 5 axes. 
   Essential disadvantages of this functionally satisfactory intermediate set-down location are as follows:
         the press installation or multi-stage press for large components requires a long overall length since the intermediate set-down locations are arranged between the processing stages and the appropriate amount of space thus has to be provided.   The number of workpiece-specific changeover parts is high.   The parked position of the crossmembers during the forming operation is restricted.   The cycle speed and functional reliability of the press may be adversely affected by the relatively large number of transporting steps.       

   This resulted in considerations to dispense with the intermediate set-down location and to integrate the necessary degrees of freedom in the transporting systems. It is thus proposed, [lacuna] DE 44 08 449 A1, to configure the transporting system such that the crossmember can be brought into a sloping position in the vertical direction. It is additionally possible to pivot an axis in the direction transverse to the transporting direction. 
   Some of the possible movements of the intermediate set-down location have thus been integrated in the transporting system, but the full functionality of this intermediate set-down location has not. 
   SUMMARY OF THE INVENTION 
   Taking the prior art as the departure point, the object of the invention is to propose a transporting system for forming machines which has the highest possible number of degrees of freedom or movement axes. 
   This object is achieved, taking as the departure point a transporting system in accordance with the invention as described below. Adantages of the invention as described in the description below and in view of the claims. 
   The invention is based on the idea of configuring a separately driven transfer for each die stage such that workpieces can undergo an optimum change in position adapted to the forming process in each case. 
   By way of example, the change in position may include the following movement axes:
         horizontal displacement in and counter to the transporting direction   sloping position in the transporting direction   displacement in the direction transverse to the transporting direction   pivoting in and counter to the transporting direction   pivoting in the direction transverse to the transporting direction   vertical change in height       

   By a different combination of the movements, the change in position is made possible during introduction of the workpieces into the die and removal of the workpieces from the die. 
   Provision is made here to ensure the functionality both for individual large-surface-area workpieces and for 2 workpieces, that is to say so-called double components. 
   In the case of the design, taking as departure point the known individually driven, crossmember-bearing transporting systems, such as carriages, slides, pivoting arm, telescopic arm, etc., the number of movement axes is increased by additional drives and movement-transmissions. By using spherical mountings, such as ball and socket joints or universal joints, a sloping position of the crossmember is also made possible. 
   Further details and advantages of the invention can be gathered from the following description of an exemplary embodiment. 
   The higher-outlay solution of transporting double components has been selected for the exemplary embodiment. If, however, the task is to transport just one large-surface-area workpiece rather than a double component, the crossmember is replaced by the sucker crossmember. This function is achieved by the attachment of die-specific transporting and retaining means to the crossmember. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows part of a multi-stage press for large components, 
       FIGS. 2   a ,  2   b  show a view of a transporting unit in the direction transverse to the transporting direction, 
       FIGS. 3   a ,  3   b  show a detail from  FIG. 2 , and 
       FIGS. 4   a ,  4   b  show a plan view of the transporting unit. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Processing stations or forming stages  8 ,  9  of a multi-stage press for large components  1  are illustrated in  FIG. 1 . Arrow  30  shows the transporting direction of the workpieces. The transporting apparatus  2  is arranged on the press upright  3  and also mirror-invertedly on the opposite upright. The transporting apparatus  2  is driven by pivot drive  6 , which is in operative connection with pivoting arm  4 . The crossmember, which is provided for workpiece-transporting purposes, is designated  5  and is mounted on the pivoting arm  4 . This figure shows, in particular, the following degrees of freedom
         vertical movement   horizontal movement   crossmember  5  pivot [sic] in and counter to the transporting direction       

   Via the pivoting drive  6 , in operative connection with a lifting drive  7 , by virtue of a combination of movements, a transporting curve or a transporting step comprising vertical and horizontal movements is executed. The transporting step serves for transferring the workpiece from, for example, forming stage  8  to forming stage  9 . If a change in position of the workpieces, on account of different removal and feeding positions, and thus better introduction and delivery is necessary, the crossmember  5  can be pivoted about the axis of rotation  12 . A drive  10  causes the crossmember  5  to pivot via a toothed-belt drive  11 . Different positions of the crossmember  5  can clearly be seen in  FIG. 1 . 
   The illustration in  FIGS. 2   a+b  shows crossmember  5  in a horizontal position and in a vertically sloping position. The figures show the mutually opposite arrangement of the transporting apparatuses  2 . 1  and  2 . 2  with fastening on the left-hand and right-hand uprights  3 . 1  and  3 . 2 . Movably arranged workpiece-specific sucker crossmembers  13  for transporting double components are provided on the crossmember  5  by way of example in  FIGS. 2   a+b . It is also possible, without any restrictions, to use just one centrally arranged sucker crossmember  13 , as is necessary, for example, for transporting a large, not yet divided blank or a large workpiece. In this case, the suckers are connected directly, as changeover parts, to crossmember  5 . A transverse-displacement movement may be provided. 
   The following degrees of freedom are illustrated in  FIGS. 2   a+b:  
         pivoting the sucker crossmember  13  in the direction transverse to the transporting direction in the case of double components   horizontal and sloping position in the vertical direction of the crossmember  5 .       

   The pivoting of the sucker crossmember  13  is described in more detail in  FIGS. 3   a+b.    
   The vertically sloping position of the crossmember  5  is achieved by different movement sequences of transporting apparatus  2 . 1  and  2 . 2 . For the compensation in length which is required by the sloping position according to  FIG. 2   b , a spline shaft  14  is provided. The universal joint  15  allows the angled position of the crossmember  5 . Instead of a universal joint  15 , an axis of rotation is also initially sufficient for this sloping position. 
     FIGS. 3   a+b  show design details for pivoting the sucker crossmember  13 . The following is also illustrated as a further degree of freedom:
         transverse displacement of the sucker crossmember  13         
     FIGS. 3   a+b  show the end of the pivoting arm  4  of the transporting apparatus  2  with the mount for the crossmember  5 . The toothed-belt drive  11  is integrated in the transporting apparatus  2  in order to pivot the crossmember  5  about the axis of rotation  12 . The spline shaft  14 , on the one hand, transmits the rotational movement and, in addition, allows the compensation in length for the sloping position of the crossmember  5 . The spline shaft  14  is fastened to the universal joint  15 . The pivotable bearing block  17  bears drives  18 ,  19 , which drive spindle/nut system  20  and  21  via shafts and angular gear mechanisms. Rods  23  arranged on both sides are in operative connection with spindle/nut system  20  and are connected to circle segment  24  and pivot the latter at the point of rotation  25 . The maximum size of the pivoting angle is W 1  and W 2 . The circle segment  24  is guided and supported by segment guides or guide rollers  26 , which are fastened on horizontal slide  27 . The workpiece-retaining sucker crossmember  13  is connected to the circle segment  24 . Guides  28  serve for guiding the horizontal slide  27 . Said horizontal slide  27  can be displaced by the distance M 1  and M 2  in relation to its central position. Horizontal slide  27  is driven, via rod  29  and spindle/nut system  21 , by drive  19 . This apparatus described may be fitted on the crossmember  5  on its own or as one of two. The combination of movements is possible by simultaneous actuation of the drives  18 ,  19 . The rotational-speed regulation may result in the same or different rotational speeds, as a result of which optimum conditions for handling the workpieces are achieved. This high flexibility may also be advantageous during die changeover, where, if appropriate, it is possible to dispense with the exchange of the component-specific sucker crossmember  13  and to execute just a horizontal movement. If, however, an exchange of the sucker crossmembers  13  is necessary, then all the movement elements on crossmember  5  remain. 
   The crossmember  5  can be disengaged at the separating location  22 , as may be necessary, for example, during a conversion from a double component to a large-surface-area single component. Advantageously, in the arrangement proposed, there is no need to exchange the drives  18 ,  19 , and these remain in the press  1 . 
   A combination of pivoting and horizontal displacement of the sucker crossmember  13  is not absolutely necessary in every case. Alternatively, the attachment may be such that only one movement is possible in each case, i.e. the slide  27  or the circle segment  24  may then be dispensed with. 
     FIGS. 4   a+b  show a plan view of crossmember  5  in a horizontal position and a horizontally sloping position in the component-transporting direction in accordance with arrow  30 . The double-sided arrangement of the actuating rods  23 ,  29  and, in extension thereof, the pivoting and transverse-displacement apparatus are illustrated. Two sucker crossmembers  13  are likewise attached. 
   Pairs of the actuating rods  23 ,  29  are fitted in each case on the spindle/nut systems  20 ,  21 , which are provided as a single unit.  FIG. 4   b  shows the following further degree of freedom:
         horizontally sloping positioning about the vertical axis in or counter to the transporting direction       

   If it is only this sloping position which is required, the function can be performed with an axis of rotation and the compensation in length by spline shaft  14 . If, however, the vertically sloping position described in  FIG. 2  is likewise envisaged, then the use of a universal joint  15  is necessary. By virtue of this design solution, any desired combination of vertically and horizontally sloping positions is also possible, and thus an
         sloping positioning in space is provided as the further degree of freedom.       

   In its maximum inventive configuration, the transporting system proposed may thus carry out workpiece manipulation in the following degrees of freedom.
         Vertical movement upward and downward   horizontal movement in and counter to the transporting direction   pivoting of the crossmember and sucker crossmember in and counter to the transporting direction   vertically sloping positioning of the crossmember and sucker crossmember   pivoting of the sucker crossmember in the direction transverse to the transporting direction   transverse displacement of the sucker crossmember   horizontally sloping positioning of the crossmember and sucker crossmember in and counter to the transporting direction   sloping positioning of the crossmember and sucker crossmember in space       

   The invention is not restricted to the exemplary embodiment which has been described and illustrated. It also covers all expert configuration within the scope of this disclosure. Thus, a universal joint is only to be understood by way of example as a movable mounting, and it is possible to use all spherical joints which satisfy the requirements of the inventive idea. 
   As has been explained, it is possible, during the transportation of single components, to dispense with a separate pivotable sucker crossmember  13  and to use crossmember  5  directly as sucker crossmember. 
   LIST OF DESIGNATIONS 
   
       
         1  Multi-stage press for large components 
         2  Transporting apparatus 
         3  Press upright 
         4  Pivoting arm 
         5  Crossmember 
         6  Pivoting drive 
         7  Lifting drive 
         8  Forming stage 
         9  Forming stage 
         10  Drive 
         11  Toothed-belt drive 
         12  Axis of rotation 
         13  Sucker crossmember 
         14  Spline shaft 
         15  Universal joint 
         17  Bearing block 
         18  Drive 
         19  Drive 
         20  Spindle and nut 
         21  Spindle and nut 
         22  Separating location 
         23  Rod 
         24  Circle segment 
         25  Point of rotation 
         26  Guide 
         27  Horizontal slide 
         28  Guide 
         29  Rod 
         30  Component-transporting apparatus