Abstract:
To improve a bending apparatus for flat material parts, comprising a bending device at which the flat material part is positioned in an insertion plane prior to bending and remains in the insertion plane during bending, and a handling device having handling axes for picking up the flat material part from a feed position, inserting it into the bending device for bending, taking it out of the bending device and placing it in a deposit position, so that the bending apparatus requires as little constructional expenditure as possible, it is proposed that the handling device comprise a positioning axis, that the positioning axis have a greater positioning accuracy than the handling axes, that, when positioning the flat material part in at least one bending position relative to a bending line of the bending device, the positioning axis be aligned parallel to the insertion plane and parallel to a direction extending transversely to the bending line, and that, with handling axes rigidly secured, the flat material part be able to be transferred by the positioning axis from a measurement position to the at least one bending position.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS  
       [0001]     This application is a continuation of international application number PCT/EP2005/009859 filed on Sep. 14, 2005 and German application number 10 2004 048 036.2 of Sep. 28, 2004, the teachings and disclosure of which are hereby incorporated in their entirety by reference thereto. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The invention relates to a bending apparatus for flat material parts, comprising a bending device at which the flat material part is positioned in an insertion plane prior to bending and remains in the insertion plane during bending, and a handling device having handling axes for picking up the flat material part from a feed position, inserting it into the bending device for bending, taking it out of the bending device and placing it in a deposit position.  
         [0003]     Such bending apparatuses are known from the prior art, for example, from WO 98/14288.  
         [0004]     In these bending apparatuses, all handling axes have such a positioning accuracy as is required for the exact positioning of the flat material part for bending.  
         [0005]     This solution demands a complex construction, particularly in the case of complicated handling devices having a large number of handling axes.  
         [0006]     The object underlying the invention is, therefore, to so improve a bending apparatus of the generic kind that it requires as little constructional expenditure as possible.  
       SUMMARY OF THE INVENTION  
       [0007]     This object is accomplished in a bending apparatus of the kind described at the outset, in accordance with the invention, in that the handling device comprises a positioning axis, that the positioning axis has a greater positioning accuracy than the handling axes, that, when positioning the flat material part in at least one bending position relative to a bending line of the bending device, the positioning axis is aligned parallel to the insertion plane and parallel to a direction extending transversely to the bending line, and that, with handling axes rigidly secured, the flat material part is able to be transferred by the positioning axis from a measurement position to the at least one bending position.  
         [0008]     The advantage of the solution according to the invention is to be seen in that it opens up the possibility of implementing the handling axes constructionally with a lesser positioning accuracy than the positioning axis and of achieving the accuracy required for the precision of the bending of the flat material part by solely the positioning axis being active in order to take the flat material part from a measurement position in which the alignment of the flat material part relative to the bending device is detected and fixed, into the at least one bending position in which a bending of the flat material part is carried out.  
         [0009]     Owing to the fact that the handling axes with their lesser degree of positioning accuracy remain rigidly secured during this movement, their lesser degree of positioning accuracy does not affect the accuracy of the bending operation.  
         [0010]     Furthermore, in accordance with the invention, the positioning axis can also be simultaneously employed as handling axis, and, therefore, the possibilities of movement available to the handling device need not be limited, namely when one of the handling axes is configured as positioning axis, or the possibilities of movement are extended, namely when the positioning axis, which can simultaneously also be employed in the usual handling operations, is added to the handling axes.  
         [0011]     Owing to the positioning axis being aligned parallel to a direction extending transversely to the bending line, a displacement of the flat material part between the measurement position and the bending position has the effect of a parallel displacement relative to the bending line and, therefore, brings about only a slight displacement in the direction of the bending line.  
         [0012]     It is advantageous for the positioning axis to be aligned parallel to a direction extending substantially perpendicularly to the bending line, so that displacements in the direction of the bending line are minor in terms of accuracy.  
         [0013]     The extending of the direction substantially perpendicularly to the bending line is to be understood as the direction lying in an angular range of between approximately 70° and approximately 110° in relation to the bending line.  
         [0014]     If, however, flat material parts are also to be positioned with a high degree of precision in the direction of the bending line, i.e., for example, flat material parts on which a least one bending edge already exists transversely to the bending line, it is particularly expedient for the positioning axis to be aligned parallel to a direction extending perpendicularly to the bending line.  
         [0015]     Moreover, in conjunction with the solution according to the invention, for a sufficiently high degree of accuracy of the positioning of the flat material it is necessary for the angle between the bending line and the direction extending transversely to the bending line to be known, so that, if this direction does not extend perpendicularly to the bending line, the path traveled in the direction of the positioning axis can be converted into a path perpendicular to the bending line.  
         [0016]     Further details of the configuration of the handling axes have so far not been given.  
         [0017]     In principle, all handling axes could be configured as linear axis.  
         [0018]     A particularly expedient solution provides that the handling device comprises rotational axes as handling axes. This does not mean that all handling axes must be rotational axes. It is also quite conceivable for some of the handling axes to be configured as linear axes and others as rotational axes.  
         [0019]     To enable bending in a simple way on all sides of the flat material part in the bending apparatus according to the invention, it is preferably provided that the handling axis is an axis of rotation extending perpendicularly to a plane in which the flat material part substantially extends.  
         [0020]     Furthermore, it is expedient for one of the handling axes to be an axis of rotation extending parallel to the plane in which the flat material part substantially extends, so as to be able to align the flat material part in a suitable manner parallel to the plane in which it substantially extends.  
         [0021]     For this reason, it is particularly expedient for the handling device to comprise at least two rotational axes as handling axes.  
         [0022]     It is even more advantageous for the handling device to comprise at least five rotational axes as handling axes.  
         [0023]     To enable optional aligning and positioning of the flat material part within a spatial area, it has proven particularly advantageous for the handling device to comprise at least six rotational axes as handling axes.  
         [0024]     The handling of the flat material part can be carried out in a particularly expedient manner with the handling device according to the invention when this has an articulated arm comprising two arms adapted for swivel movement relative to each other about an axis of articulation.  
         [0025]     Access to the feed position and to the deposit position with insertion of the flat material part into the bending device can be achieved in a simple manner with such an articulated arm.  
         [0026]     To enable the flat material part to be picked up in a simple manner with the handling device, it is preferably provided that the handling device comprises a flat material holder with which the flat material part can be picked up, moved into the bending device, positioned for bending, and finally deposited in the deposit position.  
         [0027]     The flat material holder is preferably configured such that with it the flat material part is grippable on a flat side thereof, i.e., the flat material holder does not have to engage over both flat sides but can reliably grip the flat material part from one flat side.  
         [0028]     Such gripping can be performed using, for example, vacuum suction elements or gripper elements based on magnetic interaction.  
         [0029]     In particular, when the handling device is provided with an articulated arm, it is preferably provided that the flat material holder is held at one end of the articulated arm and is rotatable relative thereto about three axes of rotation extending transversely to one another.  
         [0030]     A first one of the axes of rotation preferably extends perpendicularly to a plane in which the flat material part held by the flat material holder substantially extends.  
         [0031]     Furthermore, it is expedient for a second one of the axes of rotation to extend parallel to the plane in which the flat material part held on the flat material holder substantially extends.  
         [0032]     Finally, a further expedient solution provides that a third one of the axes of rotation extends transversely to the axis of articulation.  
         [0033]     Details have so far not been given as to the further design of the handling device. A particularly expedient solution provides that the handling device comprises a swivel arm base.  
         [0034]     It is expediently provided that the articulated arm is adapted for swivel movement about a swivel axis relative to the swivel arm base.  
         [0035]     It is particularly expedient for the swivel axis to extend parallel to the axis of articulation of the articulated arm.  
         [0036]     Furthermore, the swivel arm base is expediently rotatable about an approximately vertical axis of rotation of the base relative to a foot part.  
         [0037]     In the above explanation of the individual embodiments, the alignment of the positioning axis was not generally defined, but solely in conjunction with the positioning of the flat material part in the bending position.  
         [0038]     Accordingly, the positioning axis could be provided at any point on the handling device, for example, between two different handling axes, in particular, between different rotational axes.  
         [0039]     This does, however, have the disadvantage that before employing the positioning axis for moving the flat material part from the measurement position to the bending position, an exactly reproducible alignment of the positioning axis or an alignment of the positioning axis that is known with the necessary accuracy is required in order to have calculatable conditions for determining the path to be traveled in the direction of the positioning axis.  
         [0040]     For this reason, a constructionally particularly simple and advantageous solution provides that in all positions of the handling device, the direction parallel to the positioning axis extends with the same alignment transversely, preferably substantially perpendicularly, to the bending line.  
         [0041]     By fixing the positioning axis once it is thereby ensured that the direction parallel thereto always extends exactly with the same alignment transversely, preferably substantially perpendicularly, to the bending line.  
         [0042]     It is particularly advantageous for the positioning axis to also be arranged so as to extend parallel to the insertion plane in all positions of the handling device.  
         [0043]     The positioning axis could, in principle, be an axis that is optionally made up of movements.  
         [0044]     A particularly expedient solution provides that the positioning axis is a linear axis since the required alignment of the positioning axis can be accomplished in a particularly simple way with such a linear axis.  
         [0045]     It is also particularly expedient for the positioning axis to be arranged so as to bring about a movement of all other handling axes relative to the bending device, so that the alignment of the positioning axis relative to the bending line and relative to the insertion plane is inevitably maintained independently of the movements of the other handling axes.  
         [0046]     Furthermore, regarding the arrangement of the positioning axis, it is expedient for it to be an axis which moves the swivel arm base relative to the bending device.  
         [0047]     In the simplest case, the positioning axis is implemented by a carriage.  
         [0048]     In order to move the swivel arm base with the carriage, it is expediently provided that the carriage carries the foot part.  
         [0049]     Moreover, in the case of elongated, but relatively narrow flat material parts, to enable insertion of these in a suitable manner into the bending device, the handling device is provided with a holder positioning axis which makes it possible to displace the flat material holder relative to its connection to the handling device.  
         [0050]     The holder positioning axis is preferably arranged so that with it the flat material holder is moveable relative to the handling axes.  
         [0051]     In principle, the holder positioning axis could be configured as an axis monitored by a control system for bringing about optional displacement between two end positions.  
         [0052]     However, in order to configure the holder positioning axis as simply as possible, it is expediently provided that the holder positioning axis is designed so as to allow movement between two defined end positions, i.e., that the holder positioning axis allows a definitive and reproducible positioning of the flat material holder relative to the handling device in two end positions only.  
         [0053]     To enable the holder positioning axis to be expediently employed, in particular, in the case of long, but narrow flat material parts, it is preferably provided that the holder positioning axis is aligned perpendicularly to the longest side edge of the flat material part, i.e., that in this case the flat material part must be picked up by the flat material holder such that this alignment of the holder positioning axis in relation to the flat material part is ensured.  
         [0054]     Further details of the design of the bending device have so far not been given. In principle, the bending device could be of optional design as long as the flat material part remains in the insertion plane during bending and can thereby be kept in it by the handling device.  
         [0055]     An expedient embodiment of the bending device provides that the bending device comprises clamping tools which clamp the flat material part in the insertion plane, so that the flat material part is thereby additionally fixed during bending.  
         [0056]     In the event clamping tools are used, a particularly expedient solution provides that the bending device comprises a bending tool arranged on a side of the clamping tools that is located opposite the handling device, so that the handing device holds the flat material part in alignment in the insertion plane on the one side of the clamping tools, while the bending is carried out on the opposite side of the clamping tools.  
         [0057]     Nor have any details been given in the above explanation of the individual embodiments regarding the detection of the flat material part in the measurement position. An advantageous solution provides that the bending apparatus is provided with a measuring device, with which a position of the flat material part is detectable in the measurement position.  
         [0058]     Such a measuring device can be configured in many different ways.  
         [0059]     For example, it can be designed so as to detect the course followed by at least one edge of the flat material part.  
         [0060]     A particularly efficient and expedient solution provides that the measuring device detects the position of the flat material part at two measurement points arranged at a distance from each other.  
         [0061]     The measurement points can be expediently positioned so as to detect areas of the flat material parts that represent as precisely as possible the alignment or the dimension of the flat material part.  
         [0062]     For example, it is conceivable to provide areas of the flat material part that have been worked on in a previous operation, for example, cut-out areas of the flat material part, as such measurement points.  
         [0063]     In principle, the measurement points could be arranged on a side of the clamping tool that faces the handling device. For reasons relating to as slight a movement as possible of the flat material part between the measurement position and the bending position and, particularly with a view to as universal an employability as possible of the measuring device, in particular, for example, also for detecting bent portions, it is advantageous for the measurement points to lie on a side of the clamping tools that is located opposite the handling device.  
         [0064]     As the flat material part is usually provided with bends in which the bending line extends parallel to the measurement points, it is preferably provided that the measurement points lie in a plane which extends parallel to the bending line.  
         [0065]     Furthermore, it is preferably provided that the plane in which the measurement points lie extends perpendicularly to the insertion plane.  
         [0066]     The measurement points can be detected in many different ways.  
         [0067]     It is preferably provided that the measuring device comprises a sensor arrangement for detecting the measurement points.  
         [0068]     The sensor arrangement can be arranged fixedly relative to one of the clamping tools.  
         [0069]     A solution which is particularly expedient in terms of accessibility provides that the sensor arrangement is arranged on a bending tool carrier.  
         [0070]     In this case, an exact positioning of the bending tool has to be ensured when detecting the measurement position.  
         [0071]     For example, the sensor arrangement could still be mechanical tactile sensors.  
         [0072]     A particularly expedient solution does, however, provide that the measuring device comprises an optical sensor arrangement and a reflector arrangement located opposite the optical sensor arrangement. The measurement points can be monitored in a particularly simple way with such an optical measuring device, and, consequently, the position and the alignment of the flat material parts can be precisely recognized.  
         [0073]     In particular, a large number of measurement points in the measurement plane can be easily detected with such an optical measuring device.  
         [0074]     Further details of the arrangement of the clamping tools have so far not been given. If the clamping tools are to precisely fix the flat material part and, in addition, clamp it with great force, in order to achieve an exact bending, it is preferably provided that the clamping tools are arranged on beams which carry these.  
         [0075]     As the beams carrying the clamping tools must have a relatively large expanse in order to achieve the necessary stability for the clamping tools, it is preferably provided that a beam for a lower one of the clamping tools has a recess for at least partially receiving the flat material holder.  
         [0076]     Such a recess makes it possible to approach the respective clamping tool as closely as possible with the flat material holder and, consequently, to also bend small workpieces with the bending apparatus according to the invention.  
         [0077]     Moreover, a further advantageous embodiment provides that the beam carrying the upper clamping tool has a recess for at least partially receiving the flat material holder, so that in the case of small workpieces, the flat material holder can also be moved up as closely as possible to the upper clamping tool.  
         [0078]     The invention also relates to a method for bending flat material parts with a bending device at which the flat material part is positioned in an insertion plane prior to bending and remains in the insertion plane during bending, and with a handling device, which has handling axes, and with which the flat material part is picked up from a feed position, inserted into the bending device for bending, taken out of the bending device and placed in a deposit position, wherein, in accordance with the invention, the flat material part is transferred by a positioning axis of the handling device, which has a greater positioning accuracy than the handling axes, and which, when positioning the flat material part in at least one bending position relative to a bending line of the bending device, is aligned parallel to the insertion plane and perpendicular to the bending line, with handling axes rigidly secured, from a measurement position to the at least one bending position.  
         [0079]     Further advantageous developments of the method according to the invention have been explained hereinabove in conjunction with the bending apparatus described hereinabove and, therefore, reference is to be had to these in full.  
         [0080]     Further features and advantages of the invention are the subject matter of the description given hereinbelow and of the appended drawings of several embodiments. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0081]      FIG. 1  is a plan view of a first embodiment of a bending apparatus according to the invention;  
         [0082]      FIG. 2  is a section taken along line  2 - 2  in  FIG. 1 ;  
         [0083]      FIG. 3  is an enlarged representation of the section according to  FIG. 2  in the area of a bending device with a bending tool in starting position;  
         [0084]      FIG. 4  is a section similar to  FIG. 3  with the bending tool in a possible bending end position;  
         [0085]      FIG. 5  is a perspective representation of a handling device and a flat material part held by the handling device for bending in the region of an edge of a narrow side;  
         [0086]      FIG. 6  is a perspective representation similar to  FIG. 5  with alignment of the flat material part for bending in the region of an edge extending in longitudinal direction;  
         [0087]      FIG. 7  is an enlarged representation of an implementation of a holder positioning axis;  
         [0088]      FIG. 8  is a plan view similar to  FIG. 1  during the bending in the region of an edge of a narrow side;  
         [0089]      FIG. 9  is a plan view similar to  FIG. 1  during the bending in the region of a second edge along a longitudinal side;  
         [0090]      FIG. 10  is a plan view similar to  FIG. 1  during the bending in the region of a second edge along a narrow side;  
         [0091]      FIG. 11  is a plan view similar to  FIG. 1  immediately before depositing the flat material part on which bending has been completed;  
         [0092]      FIG. 12  is a representation similar to  FIG. 2  of a second embodiment with a flat material part lying on a flat material holder;  
         [0093]      FIG. 13  is a representation similar to  FIG. 12  of the second embodiment with a flat material part hanging on the flat material holder;  
         [0094]      FIG. 14  is an enlarged representation of the positioning of the flat material part in the bending device corresponding to  FIG. 12 ; and  
         [0095]      FIG. 15  is an enlarged representation corresponding to  FIG. 14  of the positioning of the flat material part in accordance with  FIG. 13 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0096]     A first embodiment of a bending apparatus shown in  FIGS. 1 and 2  for flat material parts  10  comprises a bending device designated  12  in its entirety for bending the flat material parts  10 , and a handling device  14  for picking up the flat material parts in a feed position  16 , inserting them into the bending device  12  and finally depositing them in a deposit position  18 .  
         [0097]     As shown in  FIG. 2 , the flat material parts  10  are positioned in an insertion plane  20  for bending in the bending device  12  and are fixed therein by a lower clamping tool  22  seated on a lower beam  24  and an upper clamping tool  26  seated on an upper beam  28  for bending by being clamped between the clamping tools  22 ,  26 .  
         [0098]     For example, the lower beam  24  is fixedly arranged on a machine frame  30 , and the upper beam  28  is movable with the upper clamping tool  26  relative to the machine frame  30  in order to introduce the flat material part  10  between the lower clamping tool  22  and the upper clamping tool  26  and clamp it by means of these.  
         [0099]     Furthermore, the bending device  12  comprises a bending tool  32  which is arranged on a bending beam  34  and together with the bending beam  34  is moveable relative to the machine frame  30  in order to bend the flat material part  10 .  
         [0100]     The bending tool  32  with the bending beam  34  is arranged on a side of the clamping tools  22 ,  26  located opposite the handling device  14  and acts on a portion  36  of the flat material part  10  projecting over the clamping tools  22 ,  26  on the side located opposite the handling device  14 , in order to bend this portion, as shown in  FIGS. 3 and 4 , at a bending line  38 , prescribed by one of the clamping tools  22 ,  26 , thereby forming a bending edge  39 , during which relative movement of the bending tool  32  with the bending beam  34  occurs relative to the clamping tools  22 ,  26 .  
         [0101]     In the case shown in  FIGS. 3 and 4 , the bending device  12  is configured as a swivel bending machine, i.e., a swiveling of the bending tool  32  with the bending beam  34  essentially occurs about a swivel axis which is essentially stationary in relation to the machine frame  30 .  
         [0102]     It is, however, also conceivable to move the bending tool in accordance with a different movement geometry, as described, for example, in international patent application WO 00/43141.  
         [0103]     As shown in  FIGS. 5 and 6 , the handling device designated  14  in its entirety comprises a flat material holder  40  for receiving the flat material parts  10 . The flat material holder  40  is configured as a frame  42  with cross bars  44 . There are provided on the cross bars  44  fixing elements  45  which, for example, by means of negative pressure or magnetic force engage the flat material part  10  on a flat side thereof and hold it so that it lies on the frame  42 .  
         [0104]     The flat material holder  40  is held with an assembly base  46  on a triaxial joint arrangement  48  for movement about the total triaxial joint arrangement  48  relative to a first arm  50  of the handling device  14 . The joint arrangement  48  makes provision for rotation of the flat material holder  40  about a first axis of rotation  52  which extends perpendicularly to a plane  54  in which the flat material part  10  extends with its portion that lies on the frame  42 .  
         [0105]     Furthermore, the joint arrangement  48  makes provision for rotatability of the flat material holder  40  relative to the first arm  50  about a second axis of rotation  56  extending parallel to the plane  54 .  
         [0106]     Finally, a third axis of rotation  58  is implemented by the joint arrangement  48 . This extends transversely to the first axis of rotation  52  and transversely to the second axis of rotation  56  and preferably parallel to a longitudinal direction  60  of the first arm  50 .  
         [0107]     The first arm  50  is, in turn, connected via an axis of articulation  62  to a second arm  64  which, in turn, with an end region located opposite the axis of articulation  62  is connected via a swivel axis  66  extending parallel to the axis of articulation  62  to a swivel arm base  68  which, in turn, is rotatable about a substantially vertical axis of rotation  70  of the base relative to a foot part  72 .  
         [0108]     In a preferred embodiment, the joint arrangement  48 , the first arm  50 , the second arm  64  and also the swivel arm base  68  and the foot part  72  form the components, rotatable about axes of rotation or swivel axes relative to one another, of a conventional joint arm robot, with which the assembly base  46  of the flat material holder  40  is moveable in space.  
         [0109]     In order to also provide the handling device  14  with a positioning axis  76 , the foot part  72  is, in turn, arranged on a carriage  74  which is moveable in the direction of the positioning axis  76 , the positioning axis  76  being aligned parallel to the insertion plane  20  and parallel to a direction  77  extending transversely, preferably perpendicularly, to the bending line  38 .  
         [0110]     The carriage  74  is mounted by means of two carriage guides  78   a  and  78   b  extending parallel to the positioning direction on a carriage carrier  80  on which a displacement drive  82  is also arranged, with which the carriage  74  is displaceable along the carriage guides  78   a, b.    
         [0111]     The carriage carrier  80  is, in turn, arranged on a floor surface  84  and fixedly positioned on this floor surface, on which the machine frame  30  of the bending device  12  is also stationarily arranged.  
         [0112]     To enable exact positioning of the flat material part  10  in relation to the bending line  38 , the bending device  12  is provided with a measuring device, designated  90  in its entirety, which comprises a sensor arrangement  92  and a reflector arrangement  94 , with which measurement points  98   a, b ,  100   a, b  lying in a measurement plane  96  extending perpendicularly to the insertion plane  20  can be checked as to whether a rim of the flat material part  10 , for example, one of the edges  102   a, b  or  104   a, b  of the flat material part  10  is positioned exactly at these measurement points  98   a, b ,  100   a, b.    
         [0113]     For example, the edges  102   a, b  of the flat material part  10  are detected at the measurement points  98   a, b , and the edges  104   a, b  at the measurement points  100   a, b , and the measuring device  90  is able to detect the alignment and position of the respective edge  102   a, b  and  104   a, b  of the flat material part  10  at the respective measurement point  98   a, b  and  100   a, b.    
         [0114]     With the inventive handling device  14  which is controllable by a machine control  108 , it is possible to pick up a flat material part as unworked flat material part  10 R in the feed position  16  with the flat material holder  40  and insert it into the bending device  12 . The flat material part  10  is aligned such that, with the portion thereof over which the frame  42  engages and which extends in the plane  54 , the flat material part  10  is positioned in the insertion plane  20 , with the clamping tools  22 ,  26  also having been opened by the machine control  108 , so that the plane  54  and the insertion plane coincide.  
         [0115]     All the axes of rotation  52 ,  56 ,  58 , the axis of articulation  62 , the swivel axis  66  and the axis of rotation  70  of the base and, in addition, the positioning axis  76  are employable for this purpose.  
         [0116]     When the flat material part  10  has been exactly positioned in the insertion plane  20 , the flat material part  10  is displaced by the machine control  108  cooperating with the measuring device  90 , which may require movement of the axes of rotation  52 ,  56 ,  58 , the axis of articulation  62 , the swivel axis  66  and the vertical axis of rotation  70  of the base and of the positioning axis  76 , until the edge  102   a ,  102   b  or  104   a ,  104   b  is positioned exactly at the measurement points  98   a, b  or  100   a, b . To position the edges  102   a ,  102   b  or  104   a ,  104   b  it may prove necessary to displace the flat material part  10  transversely to the measurement plane  96  and to also turn it relative to the measurement plane  96  until the exact desired position of the respective edge  102   a, b  or  104   a, b  at the two measurement points  98   a, b  or  100   a, b  is reached.  
         [0117]     With the flat material part  10  thus aligned, the machine control  108  causes the axes of rotation  52 ,  56 ,  58 , the axis of articulation  62 , the swivel axis  66  and the vertical axis of rotation  70  of the base to be fixed or “frozen”, so that displacement of the flat material part  10 , namely exactly perpendicularly to the bending line  38 , is only possible by the positioning axis  76 , so as to align the flat material part  10  in relation to the bending line  38  of the bending device  12  such that the bending edge  39  can be produced along the bending line  38  by movement of the bending tool  32  at the desired point on the flat material part  10 .  
         [0118]     The alignment of the measurement plane  96  relative to the bending line  38  depends on whether the portions  36  to be bent are to have an edge  102   a, b ,  104   a, b  extending parallel to or at an incline to the bending edge  39 . If the edges  102   a, b  or  104   a, b  always extend parallel to the bending edge  39 , then the measurement plane  96  is also to be aligned such that it extends parallel to the bending line  38 ; otherwise the measurement plane  96  can also extend at a distance from the bending line  38 , which varies in the direction of the bending line  38 .  
         [0119]     In the solution according to the invention, the measurement plane  96  does not have to extend at a distance from the bending line  38  that corresponds to the width of the portion  36  to be bent, but owing to the degree of freedom existing due to the positioning axis  76 , the distance can be independent of the width of the portion  36  to be bent transversely to the bending edge  39  being created, as the positioning axis  76  allows an exact displacing of the flat material part  10  after detection of its edges  102   a, b  or  104   a, b , without changing the alignment of these edges  102   a, b  or  104   a, b  relative to the bending line  38 .  
         [0120]     After bending the portion  36  extending along one of the edges  102   a ,  102   b  or  104   a ,  104   b , further portions extending along the same edges  102   a ,  102   b  or  104   a ,  104   b  can be bent without a new measurement of the alignment of the flat material part  10  relative to the bending line  38  having to be performed.  
         [0121]     When turning the flat material part  10 , the axes of rotation  52 ,  56  and  58 , the axis of articulation  62 , the swivel axis  66  and the vertical axis of rotation  70  of the base are, if required, then employable in addition to the positioning axis  76 , in particular, in order to align the flat material part  10  with one of the other edges  102   a, b ,  104   a, b  relative to the measurement plane  96 , in particular, the measurement points  98   a, b ,  100   a, b . After alignment of the flat material part  10  with the plane  54  of the portion over which the frame  42  engages coinciding with the insertion plane  20 , the axes of rotation  52 ,  56 ,  58 , the axis of articulation  62 , the swivel axis  66  and the horizontal axis of rotation  70  of the base are then frozen again, and solely a moving of the flat material part  10  relative to the bending line  38  by means of the positioning axis  76  extending transversely, preferably perpendicularly, to the bending line  38  is carried out so as to be able to bend all portions  36  in this alignment.  
         [0122]     As indicated in  FIG. 2  by the continuous representation of the arms  50  and  64  and the dashed representation of these arms  50  and  64 , the handling device according to the invention is capable of turning the flat material part  10  and, therefore, of producing in the region of the same edge  102   a, b ,  104   a, b  bends  39  which extend in the opposite direction.  
         [0123]     However, the axes of rotation  52 ,  56 ,  58 , the axis of articulation  62 , the swivel axis  66  and the vertical axis of rotation  70  of the base have to be used for this turning of the flat material part  10 , so that after use thereof a measurement using the measuring device  90  is required again, with either the edge of a bent portion  36  or the position of the bending edge  39  itself being detected with the measuring device  90  in order to then move, after freezing the axes of rotation  52 ,  56 ,  58 , the axis of articulation  62 , the swivel axis  66  and the vertical axis of rotation  70  of the base, the flat material part  10  relative to the bending line  38  solely with the positioning axis  76 , so as to obtain the exact alignment of the flat material part in relation to the bending line  38 .  
         [0124]     Owing to the constructional design of the joint arrangement  48  and the constructional size of the lower beam  24  and the upper beam  28 , it is necessary, in the case of flat material parts  10  with a short length of the edges  102   a ,  102   b  and, consequently, a short extent between the edges  104   a ,  104   b , to be able to move the flat material holder  40  up as far as possible into the bending device  12  and as close as possible to the clamping tools  22 ,  26 .  
         [0125]     For this reason, there is provided between the assembly base  46  and the flat material holder  40  a further movement axis, namely the holder positioning axis  110 , which is aligned so as to extend approximately perpendicularly to the edges  104   a, b , the extent of whose length is greater than that of the edges  102   a, b.    
         [0126]     It is, therefore, possible to displace the flat material holder  40  relative to the joint arrangement  48  in the direction of the holder positioning axis  110 .  
         [0127]     As shown in  FIG. 7 , the holder positioning axis  110  is implemented by a holder carriage  112  being guided by means of longitudinal guides  114   a ,  114   b  on a holder carriage carrier  116  for displacement in the direction of the holder positioning axis  110 , namely by means of a drive  118  which, for example, is seated on the holder carriage  112  and is able to move the holder carriage  112  in the direction of the holder positioning axis  110 .  
         [0128]     In the simplest case, only two defined positions, namely the two end positions of the holder carriage  112 , are provided as possible positions of the holder carriage  112 . In each of the end positions, the holder carriage  112  stands laterally next to the first axis of rotation  52 , so that the first axis of rotation  52  is positionable at a shorter distance from the edge  104   a  than from the edge  104   b  or at a shorter distance from the edge  104   b  than from the edge  104   a.    
         [0129]     Owing to these two end positions of the holder carriage  112 , the flat material holder  40  is always alignable by rotation about the first axis of rotation  52  such that it extends, starting from the first axis of rotation  52 , over a greater distance in the direction of the clamping tools  22 ,  26 , than, starting from the first axis of rotation  52 , away from the clamping tools  22 ,  26 .  
         [0130]     Therefore, if, as shown in  FIG. 6 , a bending of the portion  36  near the edge  104   a  is first carried out, the holder positioning axis  110  is moved such that the first axis of rotation  52  stands closer to the edge  104   b , as already shown in  FIG. 1 .  
         [0131]     Subsequently, the flat material holder  40  is rotated about the first axis of rotation  52 , and a bending of the portion  36  near the edge  102   a  is carried out, in which case, a displacement of the holder carriage  112  in the direction of the holder positioning axis  110  is not yet necessary ( FIG. 8 ).  
         [0132]     For subsequent bending of the portion  36  near the edge  104   b , the holder carriage  112  is then displaced in the direction of the holder positioning axis  110  into the opposite end position, so that, as shown in  FIG. 9 , the flat material holder  40 , starting from the axis of rotation  52 , extends with maximum extent in the direction of the clamping tools  22 ,  26 .  
         [0133]     Therefore, in a last step only the portion  36  near the edge  102   b  has to be bent, as shown in  FIG. 10 , before the finished flat material part  10 F can then finally be deposited in the deposit position  18 , as shown in  FIG. 11 , with a rotation of the finished flat material part  10 F in space being necessary in order to move it in a suitable manner out of the bending device  12 .  
         [0134]     In a second embodiment, shown in FIGS.  12  to  15 , the handling device  14  is identical in construction to the first embodiment, and the bending device  12  also exhibits the same features.  
         [0135]     However, in contrast to the first embodiment, the flat material holder  40 ′ is constructed as a holder for small flat material parts  10 ′, the frame  42 ′ having in the direction of the holder positioning axis  110  an extent which, for example, is shorter than the displacement path in the direction of the holder positioning axis  110 .  
         [0136]     Furthermore, as shown in  FIGS. 12 and 14 , the lower beam  24  has a lower beam body  130  extending with a lower, widened portion  132  between a front side  134  that faces the bending beam  34  and a rear side  136  that faces the handling device  14 . The front side  134  and the rear side  136  extend approximately parallel to each other.  
         [0137]     The lower widened portion  132  of approximately rectangular cross section is followed by a portion  138  which tapers in cross section in the direction of the lower clamping tool  22 . The portion  138  lies between a front side  134  continuing from the lower portion  132  into the tapering portion  138  and a drawn-in rear side  140  extending at an incline towards the front side  134  and at an incline to the rear side  136 . The rear side  140  therefore creates a space  142  which is set back in relation to the rear side  136  of the lower portion  132  and in which the joint arrangement  48  can partly engage and the assembly base  46  with the holder carriage carrier  116  also at least partly. The space  142  is further increased by the tapering portion  138  being adjoined by a portion  144  of offset cross section of the lower beam body  130 , which projects over the front edge  134  and ultimately carries the lower clamping tool  22 .  
         [0138]     The offset portion  144  extends over the front side  134  to such an extent that the lower clamping tool  22  ultimately lies on a side, facing away from the lower portion  132  and the tapering portion  138 , of a plane  146  in which the front side  134  extends.  
         [0139]     Therefore, as shown in  FIGS. 12 and 14 , the flat material holder  40 ′ can be positioned in its position, advanced in the direction of the lower clamping tool  22 , of the holder positioning axis  110  close to the lower clamping tool  22 .  
         [0140]     To enable the flat material part  10 ′ to be held both on its underside by the flat material holder  40 ′, as shown in  FIGS. 12 and 14 , and on its upper side, as shown in  FIGS. 13 and 15 , the upper beam  28  also has an upper beam body  150  having an upper portion  152  of widened cross section extending between a front side  154  and a rear side  156 . Below the widened portion  152  there also lies a space  162  which is set back in relation to the rear side  156  and is created by a portion  158  of tapered cross section, which lies below the widened portion  152 , having a rear side  160  set back in the shape of a step in relation to the rear side  156 .  
         [0141]     The portion  158  of tapered cross section carries the upper clamping tool  26 , which is preferably exchangeable and has a lower foot portion  164  whose cross section is offset in the direction of the bending line  38 .  
         [0142]     The space  162  is of such dimensions that it can be engaged by the assembly base  46  with the holder carriage carrier  116 , with the flat material holder  40 ′ displaced into its front end position so as to be able to hold the flat material part  10 ′ as close as possible to the upper clamping tool  26 .