EP2846943B1 - Method for automated manipulation of a bending tool, and manufacturing device - Google Patents

Description

The invention relates to a method according to the preamble of claims 1 and 2 and to a production device according to the preamble of claims 10 and 11.

WO 2012/027770 discloses a method according to the preamble of claim 1 and AT508923 discloses a method according to the preamble of claim 2.

Programmable devices for handling the workpieces as well as the bending tools are often used in the automation of bending operations. This results in high demands on the positioning accuracy of the handling equipment used, which can often not be met by conventional industrial robots and they are therefore expensive.

The object of the invention is to provide a method with which the accuracy requirements for handling devices can be reduced or to provide a production device in which the use of industrial robots as a handling device is possible.

The object of the invention is achieved by a generic method with the characterizing features of claims 1 and 2 and a manufacturing device with the features of claims 10 and 11.

Characterized in that the approach of the bending tool to the holding position or the approach of the gripping member to the holding portion of the bending tool or the workpiece to the bending position at least in a coordinate direction by a viewed in the direction of approach before the holding position or bending position and a known measuring distance relative to the tool holder Reference light beam of a light barrier arrangement is monitored and at the time of beam interruption by a direction of approach and reference light beam approximately rectangular measuring edge on the bending tool or on the workpiece an actual position of the bending tool or the gripper element or the workpiece is defined and the control device Measuring distance as a basis for calculating the remaining approach movement of the handling device from the actual position to the holding position or to the holding section or to the bending position uses et, result from the local referencing of the handling device in the vicinity of the tool holder or the bending tool lower positioning errors, since the reference light beam to the holding position or the bending position only short distances must be moved on which only small deviations may occur and resulting before referencing positioning errors are ineffective. The result is a non-contact position detection of the handling device and thus recorded bending tools or workpieces and an increase in the positioning accuracy.

The positioning accuracy can be further increased if the approach movement of the handling device is continued during the calculation of the remaining distance to the holding position or the holding section without stopping, as this further sources of error by braking and accelerating the moving members of the handling device can be avoided.

If the approaching movement of the handling device is reduced in its speed before reaching the reference light beam, the accuracy can be increased since dynamic influences in the referencing and the remaining approaching movement are thereby substantially reduced.

The local referencing in the area of the tool holder can be applied for a limited time by using the position determined by a positioning control of the handling device again for a subsequent distance movement of the handling device at a predefined distance from the holding position of the control device for the calculation of the subsequent subsequent trajectory. The global coordinate system of the handling device remains unchanged in this case. In this case, if the positioning accuracy should be too small, the local referencing according to the invention can be made possible in places where a high positioning accuracy is required by providing additional light barrier arrangements.

If the actual position is detected in two different coordinate directions by successive interruptions of the same reference light beam by two, in particular to the respective coordinate directions perpendicular, measuring edges during the approach movement, the process of inserting or gripping a bending tool or the positioning of a workpiece even more reliable run with less risk of collisions.

Alternatively, during the approach movement, the actual position in two different coordinate directions can be detected by successive interruptions of two reference light beams spaced apart in both coordinate directions by two measuring edges, thereby achieving the same advantages in positioning.

It is advantageous for the exact insertion or gripping of a bending tool if a contour defining the holding position together with the tool holder, in particular a fastening section corresponding to a receiving groove on the tool holder, is used as the measuring edge on the bending tool, since this results in the measurement of the relevant edges Position for easy insertion or gripping is relevant.

One possibility for correcting angular misalignments of the bending tool is that two measuring edges which are parallel and distant relative to one another on a surface plane of the bending tool which run at right angles to the approaching direction and the reference light beam are detected with a reference light beam. For this purpose, in a first step, the bending tool is rotated by a first helix angle relative to the reference light beam during the approach movement before reaching the reference light beam through a perpendicular to the approach direction and the reference light beam oriented axis of rotation of the handling device, whereby the first measuring edge forms a front edge. When the reference light beam is interrupted by the first measuring edge, the approaching movement is stopped and then the bending tool is rotated by a relative angle in the opposite direction until the second measuring edge interrupts the reference light beam. Based on the detected by a positioning control of the handling device position deviations of the two measuring edges and the known distance of the measuring edges to each other an angular deviation of the surface plane is determined by the target orientation, which is then compensated by a correction rotation about the axis of rotation.

The advantages of the invention are achieved in a generic production device, if on the tool holder, in particular on the handling device facing side, at least one coupled to the control device and a reference light beam in a known measuring distance to a holding position for a bending tool or to a bending position for a workpiece emitting and monitoring light barrier arrangement is arranged.

A very accurate detection of the position of the measuring edges is possible if the light barrier arrangement comprises a laser beam generator, in particular a laser diode. A laser beam with its high luminous intensity and low scattering can be monitored very closely for interruption.

In order to be able to carry out a referencing in two different coordinate directions simply, the light barrier arrangement can advantageously emit two relatively distant and parallel reference light beams in a structural unit.

The light barrier arrangement can be provided at many positions within the production facility if the light barrier arrangement comprises a transmitter unit and a receiver unit which is distant therefrom, wherein the receiver unit monitors the impact of the reference light beam emanating from the transmitter unit and is signal-connected to the control apparatus.

It is likewise advantageous for the arrangement of the light barrier arrangement if it comprises a combined transmitter-receiver unit and a beam deflection arrangement, in particular a mirror, which is distanced to this.

Referencing is particularly easy when the tool holder has an elongate receiving groove and the reference light beam is parallel to the receiving groove.

Furthermore, the light barrier arrangement can be integrated in one of the tool holders and the reference light beam perpendicular to the main plane or working plane of the bending press, whereby the exact positioning of the bending tool in the longitudinal direction of the receiving groove and / or in the direction of the depth of the receiving groove can take place.

If cooperating components of the light barrier arrangement are arranged on both tool holders and the reference light beam spans the distance between the tool holders parallel to the main plane, exact positioning of the bending tool as well as of a workpiece can be carried out in up to two axial directions.

A simple and at the same time accurate mounting of the light barrier arrangement can take place if it comprises a fastening portion, whereby it can be fastened to the tool holder like a bending tool.

For a better understanding of the invention, this will be explained in more detail with reference to the following figures.

Fig. 1

eine erfindungsgemäße Fertigungseinrichtung in vereinfachter Darstellung;

Fig. 2

eine Phase beim erfindungsgemäßen Einsetzen eines Biegewerkzeuges in eine Werkzeughalterung;

Fig. 3

eine weitere Phase beim Einsetzen eines Biegewerkzeuges;

Fig. 4

eine weitere Phase beim Einsetzen eines Biegewerkzeuges;

Fig. 5

eine weitere Phase beim Einsetzen eines Biegewerkzeuges;

Fig. 6

eine mögliche Ausführungsform der Lichtschrankenanordnung mit zwei Referenzlichtstrahlen;

Fig. 7

eine Phase beim Ergreifen eines Biegewerkzeuges bzw. nach dem Einsetzen eines Biegewerkzeuges;

Fig. 8

eine mögliche Ausführungsform der Lichtschrankenanordnung mit einem Befestigungsabschnitt;

Fig. 9

eine mögliche Variante des Verfahrens zum Einsetzen eines Biegewerkzeuges;

Fig. 10

eine weitere mögliche Ausführungsform der Lichtschrankenanordnung;

Fig. 11

eine Draufsicht auf eine weitere mögliche Ausführungsform der Lichtschrankenanordnung beim Positionieren eines Werkstücks.

Each shows in a highly schematically simplified representation:

Fig. 1

a manufacturing device according to the invention in a simplified representation;

Fig. 2

a phase in the inventive insertion of a bending tool in a tool holder;

Fig. 3

another phase when inserting a bending tool;

Fig. 4

another phase when inserting a bending tool;

Fig. 5

another phase when inserting a bending tool;

Fig. 6

a possible embodiment of the light barrier arrangement with two reference light beams;

Fig. 7

a phase when gripping a bending tool or after inserting a bending tool;

Fig. 8

a possible embodiment of the light barrier arrangement with a mounting portion;

Fig. 9

a possible variant of the method for inserting a bending tool;

Fig. 10

another possible embodiment of the light barrier arrangement;

Fig. 11

a plan view of another possible embodiment of the light barrier assembly in positioning a workpiece.

By way of introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numerals or the same component names, wherein the disclosures contained in the entire description can be mutatis mutandis to the same parts with the same reference numerals or component names. Also, the location information chosen in the description, such as top, bottom, side, etc. related to the immediately described and illustrated figure and are to be transferred to the new situation mutatis mutandis when a change in position.

All statements on ranges of values in the description of the present invention should be understood to include any and all sub-ranges thereof, e.g. the indication 1 to 10 should be understood to include all sub-ranges, starting from the lower limit 1 and the upper limit 10, i. all subregions begin with a lower limit of 1 or greater and end at an upper limit of 10 or less, e.g. 1 to 1.7, or 3.2 to 8.1 or 5.5 to 10.

In Fig. 1 1 shows a production device 1 for producing bent-formed workpieces with a bending press 2, a handling device 3, in particular in the form of a multi-axis robot, and a tool storage 4. A machine frame 5 of the bending press 2 comprises essentially two spaced apart via a transverse dressing, not shown, parallel to each other and perpendicular to a footprint 6 Level extending side stand 7 and connected to these fixed pressing beam 8 or press table. Relative to the fixed pressing beam 8, in vertical direction to the footprint 6 is an adjustable press bar 9 is guided in guide arrangements of the side stand 7 and drive connected to the side stands 7 and the machine frame 5 drive means 10, for example, hydraulic cylinders, electric spindle drives, etc. drive-connected.

Arranged on the two pressing bars are tool holders 11, which are opposite one another and are provided with fastening means, which have, for example, tool receiving openings 12. The tool holders 11 are provided for mounting with bending tools 13 in accordance with specifications for the respective workpiece part to be formed and bending process, for example with a bending die 14 in the tool holder 11 of the fixed press beam 8 and with a bending punch 15 in the tool holder 11 of the press beam 9.

Depending on the respectively to be produced for a series of workpieces or a maintenance of the bending tools 13 a reassembly and thus replacement of the bending tools 13 is required at different time intervals.

Furthermore, the production device 1 for an automated workpiece and tool transfer comprises the handling device 3, for example in the form of a multi-axis robot 16, with a gripper 17, which has at least one gripper element 18, e.g. a pliers gripper, suction pads, etc. includes. The working space of the handling device 3 preferably extends over the usable working space of the bending press 2 and the tool storage 4. The handling device 3 can be moved in a driving arrangement 19 in parallel to a front side 20 of the pressing beam 8 direction.

On the back 21 of the press bar 8 can further be provided a stop device 22 with a stop finger 23, the CNC-controlled supports the exact positioning of workpieces to be bent.

The production device 1 comprises a programmable control device 24 with which the functions of the production device 1 and its components are controlled, regulated, monitored, adjusted or otherwise influenced. In particular, this also includes the detection and control of states and positions of the articulated arms and in particular of the gripping element 18 of the handling device 3 or manipulated therewith workpieces or bending tools 13. The control device 24 can also distributed over the manufacturing device 1 subsystems, each other in signal communication include, in particular a positioning control 25 for the handling device 3, with which the positions of the various movement members and adjustment axes of the handling device 3 are controlled in the execution of handling tasks.

The invention relates to the insertion or removal of a bending tool 13 in and out of a holding position on a tool holder 11. This may relate to the tool holders 11 on the bending press 2, but alternatively or additionally also tool holders 26 on the tool storage 4, located in the working space or are within reach of the handling device 3. In Fig. 1 are a bending die 14 and a punch 15 shown in a respective holding position 27 on the tool storage 4, in each of which a bending tool 13 is held in a tool holder 26. At the bending press 2, a bending tool 13 is shown in the form of a bending die 14, which is just approximated to the tool holder 11 on the fixed pressing beam 8 or removed from this, shown.

Thus, the bending tools 13 can be brought easily and smoothly in the intended holding position 27 on a tool holder 11, 26 of the handling device 3, it is necessary that the respective holding position 27 is approached with high accuracy. In practice, there are always problems due to insufficient positioning accuracy of a handling device 3 or by the position tolerances of the tool holders 11, 26. Possible causes of positioning errors on the handling device 3, for example, a faulty workpiece position relative to the gripping element 18, zero position error of the joints of the handling device 3, arm lengths and angular errors, thermal influences, gearing, elasticities and eccentricities, elasticities and limited measurement resolution of the displacement measuring systems of the positioning 25. Similar causes can cause inaccuracies and changes of the holding positions 27 on the tool storage 4 or on the bending press 2.

Since these sources of error or their effects can often only be eliminated with great effort, the production device 1 according to the invention comprises at least one light barrier arrangement 28, by means of which the positioning accuracy of the handling device 3 in the region of the tool holders 11, 26 equipped therewith can be substantially increased with relatively little effort , In Fig. 1 For example, the tool holder 11 on the fixed pressing beam 8, and the tool holders 26 on the tool storage 4 are each assigned a light barrier arrangement 28. Of course, it is also possible to associate the tool holder 11 on the adjustable pressing beam 9 with a light barrier arrangement 28 as well.

Fig. 1 shows a holding portion 29 on the bending tool 13, on which by the gripping member 18, the connection between the bending tool 13 and the handling device 3 is made.

In the area of a tool holder 11, 26, the light barrier arrangement 28 generates a reference light beam 30, which is located in a measuring distance 31, viewed from the handling device 3, in front of the holding position 27. If the reference light beam 30 is interrupted by a predefined measuring edge on the bending tool 13 or on the gripping element 18 when the handling device 3 approaches the holding position 27, this beam interruption can be detected by the light barrier arrangement 28 and supplied to the control device 24. Since the reference light beam 30 is located in the known measuring distance 31 in front of the holding position 27, at the time of the beam interruption, an actual position of the respectively considered measuring edge can be defined, of which it is known that the remaining approximation path corresponds to the known measuring distance 31, which is relatively small is compared with the previously performed approach movement of the handling device 3.

Since the positioning inaccuracies of a handling device 3 are at least partially always proportional to the length of the path covered, also the distance traveled by the actual position defined by the reference light beam 30 up to the holding position 27 is relatively short and only a relatively small positioning error can arise here.

By the reference light beam 30, the coordinate system of the handling device 3 can be newly referenced at a short distance to the holding position 27 and thereby a possible occurring before the reference light beam 30 at a larger movement of the handling device 3 positioning error or positional deviation of the tool memory 4 are rendered ineffective. In Fig. 1 is a measuring distance 31 shown, which extends in the direction of the horizontal X-axis 32, but it is also possible to set a known measuring distance in the direction of the vertical Y-axis 33, whereby, alternatively or in addition to the horizontal X-direction 32, a reference also in the direction of the vertical Y-axis 33 can take place. The measuring distance 31 is selected from a range of a few millimeters to a few centimeters, and is thus relatively short compared to the entire range of the handling device 3, the range of such a manufacturing device in the form of a bending cell is usually several meters.

In a common industrial robot can result in a range of a few meters positioning inaccuracy, which is in the order of +/- 1 mm, since many movement members and axes of movement of the handling device 3 are involved and add the individual errors here to a considerable extent can occur during the short, remaining approach movement from the reference light beam 30 to the holding position 27 only a very small positioning error, since on this relatively short path less moving members and axes of movement of the handling device involved or at least have to perform relatively low relative movements.

As a result of this referencing of the handling device 3 in the vicinity of the holding position 27 to be approached, many of the above-mentioned sources of error in the positioning of a bending tool 13 during insertion or when gripping a bending tool 13 can be rendered ineffective by the gripper element 18. The rest of the approach movement from the reference light beam 30 to the holding position 27 takes place to a certain extent in the local coordinate system of the respectively considered tool holder 11, 26 and positioning inaccuracies due to mechanical or thermal deformations of the handling device 3 and / or the tool store 4 can thereby be eliminated. The mechanical deformations of the handling device 3 and / or the tool storage 4 depend to a great extent on the masses of the bending tools 13 used and, because of the local referencing in the vicinity of the tool holders 11, 26, it is not necessary. the computationally consuming masses or thermal influences computationally by the positioning control 25 to be considered.

In Fig. 1 The reference light beam 30 extends at right angles to the plane of the drawing and also at right angles to the approaching direction, which in the exemplary embodiment shown extends in the direction of the X-axis 32. The reference light beam 30 extends from a transmitter unit to a receiver unit, wherein the receiver unit monitors the impact of emanating from the transmitter unit reference light beam 30 and signal connected to the control device 24 and thereby the interruption of the reference light beam 30, the detection of the actual position or the subsequent recalculation can trigger the rest of the approach movement. However, it is also possible to deflect the reference light beam 30 by means of a mirror and thereby combine the receiver unit with the transmitter unit to form a structural unit.

In order to increase the accuracy of grasping a bending tool 13 with the gripping element 18, the referencing of the handling device 3 on the reference light beam 30 is performed with a measuring edge on the gripper element 18 and in this case the measuring distance 31 extends from the reference light beam 30 to the holding section 29 of FIG the tool holder 11, 26 located bending tool 13th

In the Fig. 2 to 5 the insertion of a bending tool 13 is shown in a tool holder 11, 26, wherein the remaining parts of the manufacturing device 1 have been omitted for simplicity.

In this case, the same reference numerals or component designations for identical parts as in the preceding Fig. 1 used. To avoid unnecessary repetition, the detailed description in the previous one Fig. 1 referred or referred

Fig. 2 shows a bending tool 13 which is held by a gripping element 18 of the gripper 17 of the handling device 3 and in a tool holder 11, 26, which is arranged for example on the lower, fixed pressing beam 8 or on a tool storage 4, to be used. The holding portion 29, on which the gripper 17 with the gripping element 18, coupled here in the form of a forceps gripper, is formed in the illustrated embodiment by a gripping groove 34, in which the pliers-like gripping element 18 engages. As can be easily seen, is for inserting the bending tool 13 in the tool holder 11, 26 in Fig. 2 a two-part shown in dashed lines approaching movement 35 is required, with the bending tool 13 is positioned vertically aligned over the tool holder 11, 26 and then with a vertical lowering a mounting portion 36 of the bending tool 13 in a receiving groove 37 of the tool holder 11, 26 are introduced in a first step can. Subsequently, by fixing means, not shown, for example, a terminal block, a fixing of the bending tool 13 to the tool holder 11, 26th

The receiving groove 37 has a clear width 38, which must be greater than the outer dimension 39 of the attachment portion 36. Depending on the given positioning accuracy or repeatability of the handling device 3, the clear width 38 must be chosen so large that a sufficient clearance for insertion of the attachment portion 36 is present so that when lowering the bending tool 13 no unforeseen collision with the tool holder 11, 26 can take place.

The task of the handling device 3 is to position the center plane 40 of the bending tool in the main plane 41 of the tool holder 11, 26, this being done using the light barrier arrangement 28 with the reference light beam 30.

As can be readily appreciated, the horizontal portion of the approaching movement 35 in the direction of the horizontal X-axis 32 must be at a height at which the lower edge 42 of the bending tool 13 is located above the upper edge 43 of the tool holder 11,26. By the reference light beam 30, a measuring position is defined, which is in the measuring distance 31 relative to the tool holder 11, 26 and which defines a current position with respect to the tool holder 11, 26 for a body which interrupts the reference light beam 30 at this time , As a reference point on the tool holder 11, 26 seen in the illustrated embodiment of the handling device 3 from the rear side surface 44 of the receiving groove 37 is used, but it can also be any, other reference point can be used. The selected in the embodiment side surface 44 is advantageous since, for example, the attachment portion 36 is pressed by a terminal strip against this side surface 44.

For detecting the actual position of the bending tool 13, this is approached by the handling device 3 to the holding position 27 until the reference light beam 30 is interrupted by a predetermined part of the bending tool 13 or another part of the handling device 3. In the illustrated embodiment, a measuring edge 45 is selected on the bending tool 13, which is located on the mounting portion 36 of the bending tool 3. The measuring edge 45 lies in a surface plane 46 of the attachment portion 36 and is perpendicular to the approach direction 32 of the handling device 3 and perpendicular to the reference light beam 30. Since the receiving groove 37 forms a contour that defines the holding position 27 of the bending tool 13, it is advantageous if However, it is also possible to use, for example, an edge on the front surface 47 of the bending tool 13 for the referencing.

Fig. 3 shows the time of approach movement, in which the measuring edge 45 interrupts the reference light beam 30 and the measuring edge 45 is in the known measuring distance 31 to the side surface 44 of the receiving groove 37. Thereby, an actual position of the bending tool 13 is defined, and now the control device 24 can calculate the remaining approaching movement for the handling device 3 relative to this actual position, whereby this residual approaching movement can be performed with high accuracy due to the short distance to be traveled. The remaining approaching movement is determined, for example, so that the measuring edge 45 of the attachment portion 36 is located slightly in front of the side surface 44, that is, there is little play for the subsequent lowering.

In Fig. 4 that position of the bending tool 13 is shown in which the horizontal tale approaching movement in the direction of the X.-axis 32 is completed and the measuring edge 45 is just before the side surface 44 of the receiving groove 37 and then the bending tool 13 only in the vertical direction 33 must be lowered into the receiving groove 37. Fig. 5 shows the bending tool 13 positioned in the final holding position 27, with its fixing portion 36 by means of a clamping force 48 indicated by an arrow is, can be fixed in the receiving groove 37 and thereby the surface plane 46 of the mounting portion 36 is brought into contact with the side surface 44 of the receiving groove 37 and an exact holding position 27 of the bending tool 13 is achieved.

Fig. 6 shows another possible embodiment of a light barrier assembly 28, the two spaced apart and parallel reference light beams 30 and 49 generate and monitor for interruption. With the reference light beam 30, the actual position of the bending tool 13 in the direction of the X-axis 32 and with the reference light beam 49, the actual position of the bending tool 13 in the direction of the Y-axis 33 can be detected. The bending tool 13 is thereby first approximated by the handling device 3, not shown, in the horizontal direction to the tool holder 11, 26 until the first measuring edge 45 interrupts the first reference light beam 30 and then lowered in the vertical direction until the lower edge 42 as the second measuring edge 50 of the bending tool 13 interrupts the second reference light beam 49. The horizontal approach movement is continued after the interruption of the first reference light beam 30 for a short distance, so that not one corner of the bending tool 13 must trigger the interruption of the second reference light beam 49, but a measuring point for the vertical actual position lies within the lower edge 42. A detection of the actual position can also be done with reversed flow, in which first the horizontal lower edge 42 is detected as the measuring edge and then the vertical measuring edge. The approach movement is accordingly modified to program.

From the interruption of the first reference light beam 30, any further horizontal movement of the bending tool 13 is already part of the remaining approaching movement in the direction of the X-axis 32 calculated by the control device 24 and from the first interruption of the second reference light beam 49 any further vertical movement of the bending tool 13 already a part of the remaining approaching movement in the direction of the Y-axis 33, which is also calculated by the control device 24. By this query of the actual position of the bending tool 13 both in the horizontal X-direction 32 and in the vertical Y-direction 33, the rest of the approaching movement of the reference light beams 30, 49 to the holding position 27 can be performed with increased accuracy, since a referencing of the position of the bending tool 13 can be done in two directions. It would also be possible to perform a referencing in both coordinate directions 32, 33, in that only one single reference light beam 30 is used and the approaching movement is determined in such a way that the first measuring edge 30 is detected first and then the second measuring edge 50 is also detected with the same reference light beam 30.

The approach movement of the bending tool 13 may be programmed to provide a short stoppage upon interruption of a reference light beam 30, 49, however, the approach movement is preferably continued uninterrupted, whereby the positioning accuracy can be further increased as strong braking and acceleration operations, the more Error sources can be reduced.

In Fig. 7 It is shown that with the light barrier arrangement 28, the accuracy when removing a bending tool 13 from its holding position on the tool holder 11, 26 can be increased. This is achieved in that during the approach movement 35 to the attachment portion 36 of the bending tool 13, the gripper 17 is guided so that upon approach of the gripping member 18 to the holding portion 29, for example in the form of the gripping groove 34, a referencing of the handling device 3 on the reference light beam 30th the light barrier assembly 28 can be performed. For this purpose, a further measuring edge 51 is fixed on the gripping element 18, which preferably extends at right angles to the reference light beam 30 and at right angles to the approaching direction. By the interruption of the reference light beam 30 with the measuring edge 51 on the gripping element 18, an actual position of the gripping member 18 is defined, from which only a short remaining approaching movement of a few centimeters to the holding section 29, here the gripping groove 34, is required with comparatively high accuracy can be performed.

In Fig. 7 Furthermore, a removal movement 52 of the gripper 17 is indicated by a dashed arrow, and it is possible that the referencing on the light barrier arrangement 28 which occurred during the approach movement is canceled again after the bending tool 13 has been deposited in the holding position 27 and the actual position of the gripper 17 is again determined based on the detected by the positioning controller 25 coordinates, so the unchanged coordinates of the handling device 3 are used. The local referencing on the tool holder 11, 26 is effectively canceled in this case. However, it is also possible to refer to the light barrier arrangement 28 permanently until another reference is made elsewhere.

Fig. 8 shows a possible embodiment of a light barrier assembly 28 having a mounting portion 36 and thereby like a bending tool 13 directly into the receiving groove 37 of the tool holder 11, 26 can be used. Furthermore, as in the case of a bending tool 13, a fixing can take place by means of a clamping force 48. By this type of attachment of the light barrier assembly 28 to the tool holder 11, 26 can be done easily and quickly change the light barrier assembly 28, wherein nevertheless an exact positioning of the reference light beam 30 is given. In Fig. 7 is further indicated that the light barrier assembly 28 as described above can generate a second reference light beam 49 and thus can be done with a structural unit and simple approach movement a referencing in two different coordinate directions.

Fig. 9 shows in plan view a possible further variant of the method for inserting a bending tool 13 in a tool holder 11, 26 by means of a in Fig. 9 3. The individual phases of the approach movement are identified by the letters a to e. The reference light beam 30 extends parallel to the receiving groove 37 of the tool holder 11, 26 and is monitored by the light barrier assembly 28 for interruption. In this exemplary embodiment, the light barrier arrangement 28 comprises a transmitter unit 53 at the left end of the tool holder 11, 26, from which the reference light beam 30, preferably in the form of a laser beam 54, is emitted to a receiver unit 55. The transmitter unit 53 comprises a laser light source, for example in the form of a laser diode 56, the receiver unit 55 comprises, for example, a photocell 57, with which the interruption of the laser beam 54 can be monitored and is signal-connected to the control device 24, not shown. Alternatively, it would also be possible for the light barrier arrangement 28 to comprise a combined transmitter-receiver unit 58 and a mirror 59 spaced therefrom, between which the reference light beam 30, here in the form of the laser beam 54, extends.

Due to the special nature of the approach of the bending tool 13 angular misalignments can be detected and corrected by successively two measuring edges 60 and 61, the perpendicular to the reference light beam 30, are detected. Fig. 9 shows the bending tool 13 in position a parallel to the receiving groove 37 and the reference light beam 30. When approaching the bending tool 13 is rotated by a helix angle 62, for example by 45 ° clockwise in position b, whereby the first measuring edge 60 on the front 63rd of the bending tool 13 forms a front measuring edge 64. Subsequently, the approach of the bending tool 13 in the direction of the X-axis 32 until an interruption of the reference light beam 30 takes place (phase c). At this time of interruption, a positional deviation 65 between the target position and the actual position defined by the reference light beam 30 is detected. Subsequently, an opposite rotation of the bending tool 13 takes place, for example counterclockwise, (phase d) until the second measuring edge 61 causes an interruption of the reference light beam 30 (phase e). Also at this time, a position deviation 66 between the desired position and the actual position of the measuring edge 61 is determined. From the sum of the two position deviations 65, 66 and the distance 67 between the contemplated measuring edges 60, 61, which here correspond to the tool length, the angular misalignment alpha of the bending tool 13 relative to the reference light beam 30 can be calculated as follows: $$\mathrm{tang\; alpha}=\left(\mathrm{<figure-callout\; id="65"\; label="position\; deviation"\; filenames="imgf0005.png"\; state="\{\{state\}\}">position\; deviation</figure-callout>}65+\mathrm{<figure-callout\; id="66"\; label="position\; deviation"\; filenames="imgf0005.png"\; state="\{\{state\}\}">position\; deviation</figure-callout>}66\right)/\mathrm{<figure-callout\; id="67"\; label="distance"\; filenames="imgf0005.png"\; state="\{\{state\}\}">distance</figure-callout>}67$$

The determined angular misalignment of the bending tool 13 can then be corrected by the control device 24, whereby the insertion of the bending tool 13 can be carried out with higher accuracy.

Fig. 10 shows a further alternative or additional possible embodiment of the manufacturing device 1, in which the light barrier assembly 28 is integrated in the lower tool holder 11. The reference light beam 30 extends in this embodiment perpendicular to a main plane 41 and can be monitored by this arrangement, the approaching movement of the bending tool 13 in the direction of the Y-axis 33. The insertion into the receiving groove 37 can thereby also be controlled as in the previously described directions and with little mechanical stress. In addition, the positioning in the longitudinal direction of the receiving groove 37 can be improved in its accuracy by the approaching movement is monitored by means of the reference light beam 30 in this direction.

In Fig. 11 is shown in plan view, the application of the invention for positioning a workpiece 68 in a direction indicated by dashed lines bending position 69 relative to a bending tool 13 used in a tool holder 11. In this embodiment, the light barrier arrangement 28 generates a reference light beam 30, which runs in the direction of the Y-axis 33 at right angles to the plane of the drawing and to the surface of the workpiece 68 to be bent. This direction is also parallel to the main plane 41. Through such a oriented reference light beam 30, the approaching movement in the bending position 69 in the direction of the X-axis 32 and / or in the direction of the Z-axis 70, which is oriented parallel to the receiving groove 47, to be optimized in that, when the reference light beam 30 is interrupted with workpiece edges 71, 72, an actual position of the workpiece 68 relative to the tool holder 11 and thus also to the bending tool 13 is determined. Starting from this actual position, the approach is continued by the values of the respective measuring distance 31 up to the bending position 69, which represents the desired position for the approaching movement. The method for positioning the workpiece 68 is thus performed as the previously described method for positioning the bending tool 13 by means of a contactless referencing in the vicinity of the target position to be approached and mutatis mutandis all method variants described in connection with the tool positioning can also be used for workpiece positioning.

The exemplary embodiments show possible embodiments of the method and the production device 1, wherein it should be noted at this point that the invention is not limited to the specifically illustrated embodiments of the same.

For the sake of order, it should finally be pointed out that, for a better understanding of the structure of the production device 1, these or their components have been shown partially unevenly and / or enlarged and / or reduced in size.

The task underlying the independent inventive solutions can be taken from the description.

REFERENCE NUMBERS

1 manufacturing facility 36 attachment section 2 bending press 37 receiving groove 3 handling device 38 clear width 4 tool storage 39 External dimensions 5 machine frame 40 midplane 6 footprint 41 main level 7 kickstand 42 lower edge 8th pressing bars 43 top edge 9 pressing bars 44 side surface 10 drive means 45 measuring edge 11 tool holder 46 surface plane 12 Tool receiving opening 47 front surface 13 bending tool 48 clamping force 14 bending die 49 Reference light beam 15 punch 50 measuring edge 16 multi-axis robot 51 measuring edge 17 grab 52 Distance movement 18 gripping element 53 transmitter unit 19 driving arrangement 54 laser beam 20 front 55 receiver unit 21 back 56 laser diode 22 stop device 57 photocell 23 stop finger 58 Transceiver unit 24 control device 59 mirror 25 positioning 60 measuring edge 26 tool holder 61 measuring edge 27 hold 62 helix angle 28 Light barrier arrangement 63 front 29 holding section 64 front measuring edge 30 Reference light beam 65 position deviation 31 measuring distance 66 position deviation 32 X axis 67 distance 33 Y-axis 68 workpiece 34 gripping groove 69 bending position 35 approach movement 70 Z-axis 71 Workpiece edge 72 Workpiece edge

Claims (19)

1. A method for inserting or removing a bending tool (13) into or respectively from a holding position (27) on a tool mount (11, 26) by means of a gripper element (18) of a manipulating device (3) having a programmable control unit (24), wherein a bending tool (13) held by the gripper element (18) on a holding portion (29) is moved by the manipulating device (3) into the holding position (27) and in the holding position (27) the gripper element (18) is detached from the holding portion (29) or the gripper element (18) is moved by the manipulating device (3) onto the holding portion (29) of the bending tool (13), situated in the holding position (27), and the bending tool (13), after gripping of the holding portion (29) with gripper element (18) is removed from the holding position (27), characterized in that the approach of the bending tool (13) to the holding position (27) or the approach of the gripper element (18) to the holding portion (29) at least in one coordinate direction (32, 33) is monitored by a reference light beam (30) of a light barrier arrangement (28) which, viewed in the direction of approach (32), is located upstream of the holding position (27) and at known measured distance (31) relative to the tool mount (11, 26), and at the moment the beam is interrupted by a measuring edge (45, 50, 51) on the bending tool (13) or respectively on the gripper element (18), which measuring edge is approximately at right angles to the direction of approach (32) and to the reference light beam (30), an actual position of the bending tool (13) or of the gripper element (18) is defined and the measured distance (31) is used by the control unit (24) as calculation basis for the remainder of the approach movement of the manipulating device(3) from the actual position up to the holding position (27) or respectively up to the holding portion (29).
2. A method for positioning a workpiece (68), which is to be bent, in a bending position (69) on a bending tool (13) inserted in a tool mount (11) by means of a gripper element (18) of a manipulating device (3) with programmable control unit (24), wherein a workpiece (68) held by the gripper element (18) is moved by the manipulating device (3) relative to the bending tool (13) into the bending position (69), characterized in that the approach of the workpiece (68) into the bending position (69) at least in one coordinate direction (32, 70) is monitored by a reference light beam (30) of a light barrier arrangement (28) which, viewed in the direction of approach (32, 70) is located upstream of the bending position (69) and at a known measured distance (31) relative to the tool mount (11), and at the moment the beam is interrupted by a measuring edge (71, 72) on the workpiece (68), which measuring edge is approximately at right angles to the direction of approach (32, 70) and to the reference light beam (30), an actual position of the workpiece (68) is defined and the measured distance (31) is used by the control unit (24) as calculation basis for the reminder of the approach movement of the manipulating device (3) from the actual position up to the bending position (69).
3. The method according to claim 1 or 2, characterized in that the approach movement of the manipulating device (3) is continued during the calculation of the remainder of the approach movement without stoppage.
4. The method according to one of claims 1 to 3, characterized in that the approach movement of the manipulating deice (3) is reduced in its speed before reaching the reference light beam (30).
5. The method according to one of the preceding claims, characterized in that on a subsequent removing movement of the manipulating device (3) starting from a predefined distance from the holding position (27) the position determined by a positioning control (25) of the manipulating device (3) is used again by the control unit (24) for the calculation of the further subsequent movement path.
6. The method according to one of the preceding claims, characterized in that on the approach movement, the actual position in two different coordinate directions (32, 33, 70) is detected by means of successively occurring interruptions of the same reference light beam (30) by two measuring edges (45, 50, 71, 72), in particular at right angles to the respective coordinate directions (32, 33, 70).
7. The method according to one of the preceding claims, characterized in that on the approach movement, the actual position in two different coordinate directions (32, 33, 70) is detected by means of successively occurring interruptions of two reference light beams (30,45), distanced with respect to one another in both coordinate directions, by two measuring edges (45, 50, 71, 72).
8. The method according to one of the preceding claims, characterized in that as measuring edge (45, 50) on the bending tool (13) a contour establishing the holding position (27) together with the tool mount (11, 26), in particular a fastening portion (36) projecting into a receiving groove (37) on the tool mount (11, 26), is used.
9. The method according to one of the preceding claims, characterized in that two measuring edges (60, 61), parallel and distanced relative to one another, on a surface plane (63) of the bending tool (13), which run at right angles to the approach direction (32) and to the reference light beam (30), are detected by a reference light beam (30), wherein the bending tool (13) on the approach movement before reaching the reference light beam (30) is rotated through a rotation axis of the manipulating device (3), oriented at right angles to the approach direction (32) and to the reference light beam (30), about a first angle of inclination (62) with respect to the reference light beam (30), whereby the first measuring edge (60) forms a front measuring edge (64), on interruption of the reference light beam (30) by the first measuring edge (60) the approach movement is stopped, subsequently the bending tool (13) is rotated about a relative angle in the opposite direction, until the second measuring edge (61) interrupts the reference light beam (30), and based on the position deviations (65, 66) of the measuring edges (60, 61), detected by a positioning control (25) of the manipulating device (3), and on the known distance (67) of the measuring edges (60, 61) to one another, an angle deviation of the surface plane (63) from the desired orientation is determined.
10. A production facility (1), in particular a bending cell, comprising a bending press (2), a manipulating device (3) with a programmable control unit (24), a gripper element (18) on the manipulating device (3) for the manipulating of bending tools (13) or workpieces (68), a tool mount (11, 26) arranged in the operating range of the manipulating device (3) on a pressing beam (8, 9) of the bending press (2) or a tool magazine (4) for holding a bending tool (13) in a holding position (27) and at least one light barrier arrangement (28) coupled with the control unit (24), characterized in that the light barrier arrangement (28) is arranged on the tool mount (11, 26) and transmits and monitors a reference light beam (30) in a known measured distance (31) to a holding position (27) for a bending tool (13), wherein the control unit (24) uses the measured distance (31) as calculation basis for a remainder of the approach movement of the handling device (3) from an actual position, defined by the reference light beam (30), up to the holding position (27).
11. The production facility (1), in particular a bending cell, comprising a bending press (2), a manipulating device (3) with a programmable control unit (24), a gripper element (18) on the manipulating device (3) for the moving of workpieces (68) into a bending position (69), a tool mount (11), arranged in the operating range of the manipulating device (3), on a pressing beam (8, 9) of the bending press (2) for holding a bending tool (13) in a holding position (27) and at least one light barrier arrangement (28) coupled with the control unit (24), characterized in that the light barrier arrangement (28) is arranged on the tool mount (11) and transmits and monitors a reference light beam (30) in a known measured distance (31) to a bending position (69) for a workpiece (68), wherein the control unit (24) uses the measured distance (31) as calculation basis for a remainder of the approach movement of the manipulating device (3) from an actual position, defined by the reference light beam (30), up to the bending position (69).
12. The production facility (1) according to claim 10 or 11, characterized in that the light barrier arrangement (28) comprises a laser beam generator, in particular a laser diode (56).
13. The production facility (1) according to one of claims 10 to 12, characterized in that the light barrier arrangement (28) transmits in a structural unit two reference light beams (30, 49) distanced and parallel relative to one another.
14. The production facility (1) according to one of claims 10 to 13, characterized in that the light barrier arrangement (28) comprises a transmitter unit (53) and a receiver unit (55) distanced with respect thereto, wherein the receiver unit (55) monitors the impingement of the reference light beam (30) originating from the transmitter unit (53) and is signal-connected with the control unit (24).
15. The production facility (1) according to one of claims 10 to 13, characterized in that the light barrier arrangement (28) comprises a combined transmitter/receiver unit (58) and a beam deflection arrangement, in particular a mirror (59), distanced with respect thereto.
16. The production facility (1) according to one of claims 10 to 15, characterized in that the tool mount (11) has an elongated receiving groove (37) and the reference light beam (30) runs parallel to the receiving groove (37).
17. The production facility (1) according to one of claims 10 to 15, characterized in that the light barrier arrangement (28) is integrated in one of the tool mounts (11) and the reference light beam (30) runs at right angles to the main plane (41) of the bending press.
18. The production facility (1) according to one of claims 10 to 15, characterized in that cooperating components of the light barrier arrangement (28) are arranged on both tool mounts (11) and the reference light beam (30) spans the distance between the tool mounts (11) parallel to the main plane (41).
19. The production facility (1) according to one of claims 10 to 16, characterized in that the light barrier arrangement (28) comprises a fastening portion (36), whereby it is able to be fastened like a bending tool (13) on the tool mount (11, 26).

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