EP0136598B1 - Device for manipulating metal sheets - Google Patents

Description

The present invention relates to a device for handling metal sheets, which with the help of a sheet metal working machine, for. B. are deformed by means of a sheet metal press.

Sheet metal is deformed on modern sheet metal processing machines. mostly automatically and pre-programmed by the metal sheets automatically running through the operations required for the intended profiling. However, it was found to be disadvantageous that during the profiling, i.e. H. during the successive bending operations, the sheet had to be held and supported by several assistants. It is mostly heavy and large sheet metal, which are profiled by means of the sheet metal press, the handling of which is associated with intensive work.

In EP-A-115602 (which document falls under Art. 54 (3) and is of no importance for the question of inventive step) a manipulation device for presses, in particular for press brakes, has already been proposed, which enables it, especially heavy ones and automatically and time-saving to bring bulky workpieces, such as heavy and large metal sheets, which are difficult or difficult for a single worker to move without tools, to all the necessary positions that are required, for example, for different types of folding. The known manipulation device has two rotatable pliers which cooperate with sheet metal supports which grip the sheet metal panels laterally. The sheet metal pliers are slidably arranged in three dimensions. For this purpose, a tong slide is provided, which is arranged movable up and down on a horizontal slide, which in turn is carried by a further slide, which is also displaceable in the horizontal direction, but perpendicular to the movement of the other horizontal slide. This version with three slide structures arranged one above the other is cumbersome and prone to failure.

The purpose of the invention is to propose further development in the sense of a substantial simplification and improvement of this known device.

The invention now consists in that the device is designed as claimed in claim 1.

• Fig. 1 einen Grundriss der Einrichtung in schematischer Darstellung;
• Fig. 2 einen Schnitt gemäss der Linie 2-2 in der Fig. 1;
• Fig. 2A und 2B eine vergrössert gezeichnete Einzelheit der Fig. 2 in zwei verschiedenen Stellungen;
• Fig. 3 einen Schnitt gemäss der Linie 3-3 in Fig. 1;
• Fig. 4 die Anordnung einer Zange in vergrösserter Schnittdarstellung;
• Fig. 5 eine vergrösserte Darstellung der Drehvorrichtung in Frontalansicht, und
• Fig. 6 einen Vertikalschnitt durch die Drehvorrichtung.

Further features of the subject matter of the invention emerge from claims 2 to 14, from the following description and from the drawings, which contain an exemplary embodiment of the proposed device. Show it:

• Figure 1 is a plan view of the device in a schematic representation.
• FIG. 2 shows a section along line 2-2 in FIG. 1;
• 2A and 2B show an enlarged detail of FIG. 2 in two different positions;
• 3 shows a section along the line 3-3 in Fig. 1.
• Figure 4 shows the arrangement of pliers in an enlarged sectional view.
• Fig. 5 is an enlarged view of the rotating device in front view, and
• Fig. 6 is a vertical section through the rotating device.

1 and 2, 1 denotes a sheet metal press which is known per se and by means of which sheet metal sheets are processed. The sheet metal press 1 has a ram 101 with an upper tool 102, which interacts with the lower tool 103 in the frame 104 of the sheet metal press 1. The processing, e.g. Profiling is usually carried out according to a predetermined program, the individual bending steps being controlled and monitored by a computer. On the front of the press 1 there is a main support 2 or 3 at the top and bottom and on the ram 101 there is a rotating device 105. The beams 2 and 3 extend in the horizontal direction and are at least as long as the length of the press on the front. According to the representation in FIG. 1, the main beams 2 and 3 project considerably beyond the press length both on the right and on the left. 4 and 5 each designate the shape of a lying U-shaped frame, each frame being composed of a lower and an upper horizontal support 6 and 8 and a vertical support 7 and 9, respectively. In this way, the frame 4 on the left in FIG. 1 is formed from the two horizontal beams 6 and from the vertical beam 7, while the frame 5 on the right side consists of the two horizontal beams 8 and from the vertical beam 9. As can be seen from FIG. 2, the horizontal supports 8 are arranged at the top and bottom at the height of the upper and lower main supports 2 and 3, respectively, and the entire frame 5 can be moved along the supports 2 and 3. From this figure it can also be seen that the frame 5 on the front side of the sheet metal press 1 is guided on the upper and lower main beams 2 and 3, while the end of the lower beam 8 facing away from the front lies on the floor by means of a roller 106 '. The arrangement of the frame 4, also in the front of the sheet metal press 1, is carried out in exactly the same way. The main beams 2 and 3 are fastened to the frame 104 of the sheet metal press 1 or to separate lateral vertical supports 48 (FIG. 3) and provided with rails 10 and 11, on which the horizontal beams 8 and 6 are supported by means of rollers 12. The construction below provides a pair of rollers 12 on the right and left of the carrier 8. A driven gear 13 engages in a rack 14 (FIG. 2) which is fastened along the main carrier 3 below this.

A vertical guide column 15 is arranged in each of the two frames 4 and 5 between the horizontal supports 6 and 8, respectively. Each guide column 15 is provided with lower guide rollers 16 which slide on a rail 17 along the horizontal lower supports 6 and 8, respectively. Each Guide column 15 is guided at the top by rollers 18 along a rail 49 which is arranged in the region of the upper horizontal support 8. 2 and 3, rollers 19 'and 19 "can also be seen, which form an additional upper guide for the frames 4 and 5.

On each guide column 15, first a gripper slide 20 and a beam slide 21 are arranged vertically movable. The two carriages 20 and 21 are coupled to one another and are connected by means of an upper chain 22, which is guided via deflection rollers 23, to a counterweight 24, which is connected to the beam carriage 21, which is connected by means of a lower chain 25, via the lower deflection rollers 26 is supported by rollers 27. The gripper carriage 20 is guided with the aid of rollers 28. For the vertical displacement of the gripper carriage 20 along the guide column 15, a hydraulic motor 29 is provided which drives a gearwheel 30 which meshes with a rack 31 arranged in the guide column 15.

A motor 32, which is arranged in the region of the upper horizontal support 8 and is coupled to the guide rollers 16 by means of a shaft 33, is used to move the guide column 15 along the rail 17. On the gripper slide 20 there are pliers 34 (FIG. 3) which are equipped with gripping jaws 35 and can be rotated with the aid of a hydraulic motor 26 about the horizontal axis running parallel to the frontal plane of the press. The hydraulic motor 36 has a high torque and only rotates at a low speed. The closer design of the pliers 34 will be explained later with reference to FIG. 4.

A hydraulic motor 37 is provided on the beam slide 21, which drives a gear 38 which meshes with the toothed rack 31. Furthermore, a support beam 39 is provided which extends horizontally between the guide columns 15 and below the pliers 34 and is attached to the beam slide 21 with the aid of brackets 40. The arrangement is such that the support bar 39 can be swiveled out of the swiveled-out normal position shown in FIGS. 2 and 2A into the position shown in FIG. 2B, in which the support bar 39 is no longer in the area of the pliers 34, but is located next to the column 15 so that the pliers 34 can be moved very close to the front of the press 12. The pivoting of the support beam 39 is carried out by hydraulically or pneumatically adjustable joint supports 41, which are connected to the boom 40 and to the column 15.

A centering chain drive 42 is arranged in the support beam 39, which causes the support beam 39 to be adjusted horizontally so that it always assumes a symmetrical position with respect to the two guide columns 15. Furthermore, a support roller 43 is arranged directly in front of the gripper jaws 35 of the pliers 34, which is accommodated in a holder 44 and follows the movements of the pliers 34 along the support beam 39. Further support rollers 45 are mounted along the support beam 39 in pivotable supports 46 which are under spring action or are loaded by a counterweight which hold the supports 46 in the position shown in FIG. 3. When the vertical guide column 15 moves along the support beam 39, the supports 46 are pivoted clockwise. With 47 a fixed support roller is designated, which is arranged in the middle of the support beam 39.

The closer design of the pliers 34 and gripping jaws 35 can be seen in FIG. 4. The gripping jaw 35 shown has a fixed jaw part 51 and a movable jaw part 52. The fixed jaw part 51 is equipped at its end with a pair of pliers 53 which can be pivoted about a bolt 54 and which interacts with the pliers half 55 of the movable jaw part 52. This pliers half 55 is pivotally mounted about a bolt 56. The two pliers halves 53 and 55 are under the action of a spring, which strives to keep the two pliers halves in the open position shown. It should also be mentioned that the two pliers halves 53 and 55 correspond to the pliers designated 34 in FIGS. 1 to 3. The pliers halves automatically adapt to the shape of the piece of sheet metal which they are intended to grip. Whether a piece of sheet metal is in the pliers or not is indicated by a light barrier which has a transmitter 57 in the fixed jaw part 51 and a receiver 57 'in the movable jaw part 52. The movable jaw part 52 is pivotally mounted about a pin 58 and carries a guide roller 59 at its end remote from the pliers half 55, which cooperates with a guide roller 60. With 61 a spring is designated, which keeps the jaw parts 51 and 52 open.

The jaw halves 51 and 52 are provided with a collar-shaped shoulder 62 and are mounted in a housing 66 so as to be rotatable about the longitudinal axis. To close the pliers, the jaw part 52 is pivoted about the pin 58. For this purpose, a piston 63 is provided, which is located in a cylinder 64 and has a wedge-shaped part 65 directed against the pliers. When the piston 63 is shifted from left to right in FIG. 4, the wedge surface of the wedge-shaped part 65 pivots the pliers half 52 about the bolt 58 by lifting the guide roller 59 as the wedge surface advances. The cylinder 64 of the piston 63 is rotatably mounted in the cylindrical housing 66, the axially arranged rotary drive being designated by 67. This rotary drive enables a rotation of 360 ° in both directions. The cylindrical housing 66 is provided with pressure connections 68 and 69, which are connected to the space for receiving the piston 63 through bores 70, 71 through the wall of the cylinder 64. The gripping jaws 51, 52 can be opened and closed by actuating the pressure.

The gripper jaws 51, 52 are equipped with pliers actuation, consisting of parts 63, 64, 65, 66 and rotary drive 67 with the help of two cylinders rule holders 72 with the gripper slide 20 in connection, which connection is formed by two guide arms 73, which is guided by means of a guide roller 78 in a rail 79 of the holder 72. Between the two arms 73 and the associated brackets 72, a housing 74 is inserted, in which there are four star-shaped offset pressure cylinders 75 with pistons. The housing 74 is arranged in the cylindrical holder 72 in such a way that if the pressure pistons in the cylinders 75 are extended, they lock the holder 72 so that a rigid connection is formed between the slide 20 and the cylindrical holder 72. If the pressure pistons in the cylinders 75 are withdrawn, a limited play occurs between the two parts, which corresponds to the gap width that is present between the holder 72 and the housing 74. The slide 20 uses the guide arm 73 to carry out the theoretical movement of the gripping jaws 51, 52 calculated by the computer, which is composed of circular arcs. In fact, there are small deviations. which lead to tensions in the sheet metal with a rigid connection. On the one hand, this is clamped and deformed in the press and, on the other hand, it is held between the pliers halves. In order to avoid the occurrence of such dangerous tensions and to prevent possible damage to the sheet to be processed, the pistons are retracted into the star-shaped pressure cylinders 75 during processing, so that the cylindrical holders 72 can move and yield somewhat. The pressure line for pressurizing the pressure piston is designated 77 and a fixing lock with 76, which prevents axial movement of the housing 74.

The more detailed design of the rotating device 105 can be seen from FIGS. 5 and 6. This rotating device is arranged on the butt) 101 of the sheet metal press and is shown in front view in FIG. 5 and partially in vertical section in FIG. 6. The rotating device 105 has a base plate 106 ', which is held in an adjustable manner on the plunger 101 by means of holding members 107. The holding members 107 overlap the base plate in the region of the corners thereof and have spacing screws 108, by means of which the base plate 106 can be precisely adjusted and fixed by means of clamping screws 109 inserted into the plunger 101.

The base plate 106 carries a housing 110 in which a worm gear is accommodated. The shaft of the worm gear is designated 111. It extends perpendicular to the base plate 106 and to the plunger 101 from the housing 110 and carries a hub 112, which is held on the shaft by means of a holding disk 113. A holding plate 114 is attached to the outer end of the hub 112. A stop lever 115 is also connected to the hub 112, by means of which the rotation of the shaft 111 can be precisely limited. For the mechanical rotation limitation of the stop lever, adjustable stops 116 and switches 117 are provided, which serve to switch off the drive motor of the transmission. This drive motor is flanged to the side of the gear housing 110 and is designated 118. Instead of the mechanical rotation limitation described by means of stop lever 115, electronic regulation can also be present. In this case, an angle stepper 119 is arranged on the gear housing 110 for the electronic regulation of the angle of rotation, while the stop lever 115 and the stops 116 including the switch 117 are omitted.

The holding plate 114 is bar-shaped and extends horizontally along the sheet metal press in the rest position. A number of magnets 120 are arranged on this holding plate 114, which can be energized and thereby lose their magnetic effect. Instead of this electrically releasable magnetic connection, it is also possible to arrange suction or gripping elements which act by applying a vacuum.

By means of these magnets 120, a metal sheet can be held and rotated about an axis running perpendicular to the metal sheet, as will be described in more detail later.

The sheet metal sheet to be processed is fed into the sheet metal press 1 in an approximately vertical position by a feed carriage (not shown) and is gripped by the tongs 34. The bottom of the feed carriage, on which the sheet metal sheet rests with an edge, forms a reference surface with respect to which the tongs 34 are oriented and adjusted. For this purpose, the two vertical guide columns 15 are maneuvered in such a way that the open gripping jaws 35 of the pliers 34 grip over the side edges of the sheet metal plate and hold them in place as soon as the edge of the sheet metal plate contacts the base of the pliers mouth. By moving the pistons 63, the pliers halves 55 are closed, the sheet metal plate is held in a vertical position and is lifted upward from the reference surface by the movement of the two gripper slides 20. The rotary drive 67 is actuated until the metal sheet assumes the horizontal position and is supported by the rollers 43, 45 and 47. Subsequently, the two guide columns 15 are moved in the horizontal direction together with the sheet metal plate supported by the rollers 43, 45 and 47 against the tool ram 101 of the sheet metal press 1, namely at a height which the same is inserted between the upper and lower tools 102 and 103 the sheet metal press enables. The clamping force of the pliers halves 55 is temporarily reduced in order to position the sheet metal plate precisely. The pliers halves 55 then close and the metal sheet is ready for processing. When folding, the sheet metal plate held by the pliers 34 describes a precisely precalculated pivoting movement, which is carried out exactly by the gripping jaws 35 by the gripping jaws describing the path calculated theoretically and controlled by the computer. This theoretically determined route does not exactly correspond to the actually described route, since there are always small deviations due to the sheet quality and other influences. These deviations would create stresses in the sheet metal, which can have an adverse effect. In order to avoid the occurrence of such stresses, the pistons are retracted into the pressure cylinders 75 arranged in a star shape, so that the cylindrical holders 72 can move and yield somewhat.

A further additional addition is also possible in that the relative movement between the movable pliers bodies and the remaining rigid parts of the guide is measured electrically and the determined differences are entered into the control for correcting the subsequent movement calculated by the control.

If on one of the three other side edges of the sheet metal plate a bend is made which is in the same direction as the sheet plane, the sheet metal plate is brought back into the vertical position by rotating the pliers 34 and by moving the columns 15 on the rails 17 and by lifting the gripper slides 20 of the rotating device 105 fed. There, the metal sheet is held in place by the magnets 120, whereupon the pliers 34 are opened and the columns 15 are withdrawn to the left in FIG. 3. The rotating device 105 is operated by actuating the motor 118, so that the metal sheet is rotated in the vertical plane. The angle of rotation can be precisely set or programmed. The sheet metal plate is then gripped again in a vertical position by the pliers 34, whereupon the holding magnets 120 are switched off. The sheet metal plate is brought into the horizontal position by rotating the pliers 34 and moved again by the required amount under the tool stamp. The other bends run exactly the same as the first bend described. If a further bend in the same direction is required, the sheet metal plate is rotated about the axis of the two pliers 34.

If narrow sheet metal strips are processed, in which the pliers 34 have to be brought close to the tools 102, 103, the support beam 39 is brought into the position shown in FIG. 2B by pivoting the boom 40, so that the vertical columns 15 together with the gripper slide 20 can approach very close to the tool ram 1. This position is shown in broken lines in FIG. 2.

By moving the frames 4 and 5 along the front of the sheet metal press 1, by the mobility of the guide columns 15 and associated frames 4 and 5 and not least by the vertical height adjustment of the pliers 34 and the support beam 39, the gripping jaws 35 can not only any Take position, but be moved in a simple and very precise manner by a computer control. The arrangement of the rotating device 105 offers the possibility that the sheet metal plate can also be rotated about an axis running perpendicular to the front side of the press and can thus be brought into any position.

Claims (14)

1. Device for handling sheet-metal panels to be deformed in a sheet-metal-working machine (1) with the assistance of two rotary tongs (34) able to move in three dimensions for lateral engagement of the sheet-metal panels and of sheet-metal supports (39), in which case provided on the front side of the sheet-metal-working machine (1) in two vertical planes at right angles to the frontal plane is a frame (4, 5) each able to slide along the front side and having the shape of a horizontal U and which on the ends of the sides of the U-shape is guided to slide in supports (2, 3) arranged on the front side of the sheet-metal-working machine, along the latter, whereby in each frame (4, 5) a vertical guide pillar (15) able to move in the plane of the frame (4, 5) is inserted between the sides of the frame (4, 5) and is equipped with a gripper carriage (20) for receiving vertically adjustable tongs (34) and with a beam carriage (21) for receiving a support beam (39).

2. Device according to claim 1, characterised in that provided on the front side of the sheet-metal-working machine (1) is a rotary device (105), which comprises a rotary retaining member (114) for retaining the workpiece to be machined in the vertical position parallel to the front plane of the sheet-metal-working machine (1) and for rotating the latter in this plane about a horizontal axis at right angles to the front plane.

3. Device according to claims 1 and 2, characterised in that the retaining member is constructed as a beam-like retaining plate (114) and is provided with magnets (120) which can be switched on and off or with pneumatic or mechanical retaining members.

4. Device according to claim 3, characterised in that the retaining plate (114) is provided with vacuum suction members.

5. Device according to claims 1 to 4, characterised in that the beam-like retaining plate (114) is located on the shaft (111) of a gear unit (110) and is able to rotate with an adjustable angle of rotation.

6. Device according to claims 1 to 5, characterised in that a stop lever (115) is connected to the driven shaft (111), which stop lever cooperates for limiting rotation with adjustable stops (116) and with switches (117).

7. Device according to claims 1 to 5, characterised in that provided for the drive and for limiting the rotation of the shaft (111) is a rotary digitizer (119) with an electronic control unit.

8. Device according to claim 1, characterised in that the gripper carriage (20) and the beam carriage (21) are connected to each other and can be driven jointly.

9. Device according to claim 8, characterised in that the beam carriage (21) comprises a support beam (39), which is attached in a tilting manner to the beam carriage (21) by means of brackets (40).

10. Device according to claim 9, characterised in that provided between the gripping jaws (51, 52) of the tongs (34) together with the tongs actuation arrangement (63, 64, 65) and rotary drive (67) and gripper carriage (20) is a connection (72, 73, 74) with an adjustable intermediate member (74).

11. Device according to claim 10, characterised in that the intermediate member is constructed as a housing (74) for receiving pressure cylinders (75) arranged in the form of a star with pistons and it is arranged in a cylindrical mounting (72), against which the extended pistons abut in the pressure cylinder (75).

12. Device according to claim 11, characterised in that attached to the housing (74) is a guide arm (73), which supports a guide roller (78), which is guided in a rail (79) of the gripper carriage (20), whereas the cylindrical mounting (72) is rigidly connected to the housing (66) for receiving the arrangement (63, 65) for actuating the tongs.

13. Device according to claim 12, characterised in that when the piston of the pressure cylinder (75) is retracted, the cylindrical mounting (72) is arranged to oscillate about the guide roller (78) and to move with respect to the housing (74) by the gap width which exists between the two parts (72, 74).

14. Device according to claim 13, characterised in that the relative movement between the movable tong bodies and the remaining rigid parts of the guide is measured electrically and the differences ascertained are fed into the control unit for correcting the sequential movement calculated by the control unit.

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