EP0135095B1 - Peripheral accessory device for automatically loading and unloading a punching and nibbling machine - Google Patents

Abstract

The invention concerns a peripheral auxiliary system for the automatic feeding and unloading of a stamping/nibbling machine. In machines of this kind, the blanks have previously beed fed in by automatic devices. Other transport or depositing devices have been provided for the stamped parts and the stamped-out blanks. For these purposes, an industrial robot with a gripping mechanism is be used. According to the invention, the gripping mechanism of the robot is also designed to remove the stamped parts, and a stacking means is provided, whose delivery surface can be swiveled and displaced uniformly in one operation.

Description

The invention relates to a peripheral auxiliary device for the automatic loading and disposal of a punching-nibbling machine according to the preamble of claim 1.

Punching-nibbling machines are used to punch out pre-fabricated parts of specified geometry from raw boards with a larger footprint. To guide the blanks, such a punching-nibbling machine usually has a ruler with which the blanks can be moved in a certain area. The parts of the desired geometry can be punched out using a punching head, which receives the appropriate tools from the assigned cutting tool turret magazine.

• a) Einlegen der Rohplatine
• b) Stanzen
• c) Entnehmen der Fertigteile und

gegebenenfalle AbfallstückeWhen operating a punching-nibbling machine, the following operations are carried out one after the other.

• a) Insert the raw board
• b) punching
• c) removing the finished parts and

any pieces of waste

d) removing the residual board grid or, if necessary, remaining strips.

The operations a), c) and d) used to be done mostly manually. In modern, numerically controlled punching-nibbling machines, specific solutions for automating these operations are known, but they only apply to certain workpiece geometries and are integrated into the specific machine. In the magazine "Werkstatt und Betrieb" Vol. 116, No. 9 (1983) on the subject of "More flexibility and automation in non-cutting production" are described, among other things, sheet metal processing centers, which at the 5th EMO (10th to 18th June 83) were exhibited, in which an industrial robot for automatic tool change can be assigned to a punching-nibbling machine in particular, and the workpiece is handled by magnetic or suction lifting devices that can be picked up by the grippers. The loading of the machine on the one hand and the removal of the finished workpieces on the other hand should be possible automatically, with the workpieces in particular being able to be placed on pallets. In addition, from SU-A-663 465 an auxiliary device is known with a gripper serving according to the vacuum suction principle, with which workpieces of predetermined geometry can be handled.

Furthermore, DE-A-27 21 440 describes an independently operating stacking device for stacking sheet metal sections, in which the stacking device forms a pivotable and displaceable roller conveyor. DE-A-10 51 737 in particular discloses a so-called rocker table, the posts of which form swivel bearings both with the standing surface and with the storage surface.

In contrast, the object of the invention is to create a peripheral auxiliary device using an industrial robot, with which the loading and disposal of a punching-nibbling machine can be further optimized.

The object is achieved by the characterizing features of claim 1. Further developments of the invention are preferably specified in the subclaims.

It is particularly advantageous in the invention that punching-nibbling machines which have been manually loaded or disposed of so far can also be retrofitted without mechanical changes to the machine. With the overall arrangement - that is essentially a freely programmable handling device and the peripheral auxiliary device according to the invention - a system is created with which the most varied of workpieces can be handled under program control.

In the invention, the special design of the gripping device on the one hand and the storage device on the other hand play an important role. Since both the large delivery boards and the possibly small finished parts are to be handled with the punching machine with the auxiliary device and the latter are only accessible through a narrow channel when the pliers ruler is advanced far in the machine, the gripping device is V-shaped and has one after the other Vacuum suction principle working adhesive device suction cups in different, possibly changeable distance, which can be activated by program. In preferred training, group activation of certain suction cups is possible. This proves to be advantageous in particular for the residual board grids, which can practically only be grasped at the clamping edge by means of the suction cups for removal. For this purpose, an intermediate storage device is also provided, the storage surface of which can be pivoted and displaced in one operation. Such a storage device known per se is referred to as the "rocker table" and makes it possible to layer the residual lattice structures that are sensitive to bending and interlocking in layers.

Further details and advantages of the invention result from the following description of figures of exemplary embodiments with reference to the drawing.

• FIG 1 eine schematische Darstellung der Stanz-Nibbel-Maschine einschließlich der zugehörigen erfindungsgemäßen peripheren Hilfseinrichtung.
• FIG 2 eine spezifische Ausbildung der Greifvorrichtung.
• FIG 3, Arbeitspositionen der Greifvorrichtung und
• FIG 4 schematisch in verschiedenen Betriebspositionen einen sogenannten "Wippentisch" als Zwischenlagereinrichtung.

Show it

• 1 shows a schematic representation of the punching-nibbling machine including the associated peripheral auxiliary device according to the invention.
• 2 shows a specific design of the gripping device.
• 3, working positions of the gripping device and
• 4 schematically shows a so-called "rocker table" as an intermediate storage device in various operating positions.

Identical parts are provided with the same reference symbols in the figures.

1 shows the frame of a punching-nibbling machine, which is numerically controlled in modern technology. The punching head of the machine, to which a cutting tool turret magazine 12 is assigned, is designated in detail by 11. The punching-nibbling machine is assigned 1 different work tables for handling the raw blanks, finished parts and scrap skeletons. Under the punching head 11 there is a fixed table 15, which is followed at the rear by a crawler link table 16. On the back of the crawler link table 16, a ruler 17 for guiding the boards during processing is arranged. The travel range of the ruler 17 is indicated by 18. A so-called "rocker table", which serves as an intermediate storage facility, is identified by 20. In addition, a storage table 25 for finished parts is provided.

An industrial robot 30 is assigned to the punching machine 1 described above. Such robots with a handling arm 35 are known from the prior art. A gripping device 40 is attached to the handling arm 35, with which raw boards, finished parts and scrap skeletons can be handled. The gripping device 40 is described in detail below. Furthermore, a raw board stack is indicated in FIG. 1, which is designated by 19.

From FIG 2 it can be seen that the gripping device 40 is constructed from a V-shaped frame. With 41 to 44 mechanical carriers are designated, which are arranged by appropriate connecting devices 45 to 48 in the intended geometry. The fastening unit for the robot arm 35 is designated by 49.

The gripping device is geometrically designed such that the support arm 42 comes to rest on the edge of a circuit board, while the support arm 41 approximately represents the diagonal. The gripping device works with suction elements based on the vacuum suction principle, with which flat parts such as blanks, stamped parts and / or scrap skeletons can be handled. Suction cups 51 to 64 are therefore attached to both supports 41 and 42 at a predetermined distance, which can be connected to a pneumatic vacuum system and can be activated individually or in groups in the sense of suction on a surface.

In a V-shaped angle, two suction cups 65 and 66 on the front are also attached via a cantilever 50 which can be moved mechanically or pneumatically.

From the detail drawing for the boom 50 it can be seen that the boom arm can consist of a rod 501 which can be displaced in its longitudinal axis, a gear chain 502 and an associated helical spring 503. Instead of the coil spring, a pair of leaf springs can also be used to align the chain. With such a design, longitudinal and transverse displaceability is ensured in a simple manner with sufficient stability of the boom 50. The entire boom gripper arm 50 is thus designed such that it can be loaded in the vertical direction when the suction cups 65 and / or 66 are sucked in with the weight of a finished or waste part, but is flexible and displaceable in the horizontal direction.

From Figure 2 it can be seen that the suction cups 51 to 66 are arranged at predetermined intervals on the frame. The distances can be changed manually or in a controlled manner. It is essential that the individual suction cups 57 to 66 can be activated separately or according to groups according to a control program, which is important in the context of the alternative handling of the raw boards, waste or finished parts and / or the residual skeleton. Different suction cup groups or areas must be activated for the various work steps. This is shown in detail in FIG 3 for four examples.

3 shows that the V-shaped design of the gripping device with an edge area and a diagonal area is advantageous for rectangular parts.

In sub-figure a, the black suction cups are activated for lifting a blank 19. Usually not all of the edge or diagonal suction cups are required; the suction cups 65, 66 of the boom 50 are not activated.

In the case of sub-figure b, on the other hand, a residual grid 190 from which finished parts are punched out is to be handled. For this purpose, only the suction cups in the edge area are required, with the grille 190 being pulled out horizontally in this case, as will be shown below with reference to the workflow.

Part c shows the activation of suction cups for a larger finished part 191. Depending on the size of such a part, suction cups in the V-shaped tip area and also on the correspondingly extended arm 50 are activated.

In the case of small prefabricated parts 192 according to sub-figure d, it may suffice if only one suction cup of the boom 50 is activated.

It has already been mentioned that, in principle, each suction cup can be activated individually according to the program. However, since because of the limited load capacity, it is generally not possible to mount any number of solenoid valves on the robot arm and only a limited number of functions, db switching signals, are available from the robot 30 itself, the suction cups 51 to 66 are advantageous in specific groups Problem adjusted activated. It has been shown that a sufficient combination possibility is given with six on / off switching signals. The choice of combinations depends not only on the size of the parts, but also on their geometry. For small parts with small ones or narrow contact surfaces for the suction cups, for example, it may be necessary to use specially developed suction cup structures.

4 schematically shows the function of the so-called "rocker table" 20 for storing the scrap skeletons. Such a rocker table is attached to the base 210 with its storage surface 201 via four swivel joints 202 to 205 via mechanical levers: the function essentially consists in the fact that such a rocker table 20 with its storage surface 201 can be pivoted and moved in the same operation. This is indicated in the partial figures a, b and c. 220 identifies the storage area for the scrap skeleton to which a vertical stop surface 221 is assigned.

With the residual grating 190 resting on the surface 201, the rocker table 20 can be tilted at an angle. When a certain helix angle of the surface 201 is reached, a residual screen 190 can slowly slip due to the overcoming of the static friction. However, it makes sense to give the movement sequence a certain dynamic. For this purpose, the table 20 is pivoted at a predetermined speed against a lower, possibly damped stop, so that the scrap skeleton 190 shoots obliquely forward against the stop 221. The scrap skeleton 190 slides down with the leading edge down to the level of an already existing stack 225. By pivoting the rocker table 20 back at a predetermined speed or acceleration, the scrap skeleton board 190 is not pulled along due to its inert mass and remains in contact with the stop edge 221 until the support from the surface 201 is lost on the other side edge. The board folds onto the existing stack.

• Mit der Greifvorrichtung 40 wird eine Rohplatine 19 vom Rohteilstapel abgehoben und in das Zangenlineal 17 gegen den Anschlagbolzen in einer festgelegten Standardposition eingelegt. Dabei ist der Wippentisch 20 zur Unterstützung durchhängender, dünner Blechplatinen hochgeklappt. Am Greifer sind in diesem Fall entsprechend FIG 3a die Saugnapf-Reihe "Rand" und die Saugnapf-Reihe "Diagonale" aktiviert.

The entire workflow is described below with the aid of the auxiliary device according to the invention, reference being made in this connection to FIGS. 1 to 4, in particular FIG. 1:

• With the gripping device 40, a blank 19 is lifted from the blank stack and inserted into the pliers ruler 17 against the stop bolt in a defined standard position. The rocker table 20 is folded up to support sagging, thin sheet metal plates. In this case, according to FIG. 3a, the "edge" suction cup row and the "diagonal" suction cup row are activated on the gripper.

The rocker table 20 is folded down for the punching process. This is followed by the numerically controlled punch-nibble program sequence up to the free separation of a first finished part. The punching machine 1 then goes into the holding lock. Subsequently, the robot arm 35 is pivoted in and the gripping device 40 with the cantilever arm 50 moves forward into the channel between the pliers ruler 17 and the cladding of the cutting tool magazine 11. After this, a finished part can be removed, with one or more suction cups being activated as required on the gripper tip . Precast parts are deposited, for example, on the deposit table 25. Waste pieces can also be removed and dropped in a waste container.

After all finished parts have been punched out of a blank, the pliers ruler 17 returns to the standard position and the punching-nibbling machine 1 goes into the holding position. Then the rocker table 20 is folded up.

To remove a residual grid 190, only the row of suction cups located at the edge is now activated in accordance with FIG. 3b, because the other area is more or less punched out. For this purpose, the pliers ruler 17 is in the same standard position as when inserting the raw boards. The gripper is therefore placed with its edge area at the same defined point. In order to remove and lay down the scrap skeletons 190 in layers, such a part is slid over and put down by the gripping device from the crawler link table 16 onto the rocker table 20. After loosening the suction cups, the gripping device 40 moves into a waiting position.

Then the rocker table 20 is folded over, so that, as described in detail with reference to FIG. 4, the remaining grid 190 slides off at an angle and comes to lie one above the other in layers.

It has been shown that the peripheral auxiliary device according to the invention enables optimal handling of the blanks, finished parts and scrap skeletons for a punch-nibble machine with an existing industrial robot.

On the basis of FIGS. 2 and 3 it was shown that the suction cups of the gripping device can be activated according to the program. In addition to these features, the exact positioning can also be changed and carried out according to the program. For this purpose, the suction cup holders would have to be arranged displaceably on the frame, for example by pneumatic cylinders. One design option would be to limit the displacement of the suction cup holders by means of a grid of programmable stops. In practice, it may be sufficient in many cases if the extension arm 50 is equipped accordingly.

Overall, when implementing additional programming options, it is always important to utilize the control signals available on the robot arm by means of a combination evaluation circuit in such a way that the control options. be reproduced. If six signals are present, 2 ⁶ = 64 switching state variants can then be used.

Claims (15)

1. A peripheral auxiliary device for automatically loading and unloading a punching and nibbling machine using an industrial robot (30), comprising, on the one hand, a gripper device (40) for blanks (19), operating in accordance with the vacuum suction principle, and, on the other hand, associated transport and depositing devices (20) for the punched-out parts (192) and residual lattices (190),
characterised by the following features:

- the gripping device (40) forms a flat V-shaped framework (41 to 44) which in relation to a blank (19) has a peripheral carrier (41) and a diagonal carrier (42), where

- the peripheral carrier (41) and diagonal carrier (42) of the V-shaped framework (41 to 44) are provided with a number of suction cups (51 to 64) having vacuum line terminals, which are arranged in groups and which can be activated group-wise in such manner that

- by appropriate activation of the suction cups (51 to 64), the gripping device (40) can alternatively handle large-area blanks (19), small- area punched-out parts (191,192) and/or the residual lattices (190), where

- in order that the residual lattices (190) may be stacked in layers, a lifting table (20) is provided which serves as an intermediate device and the depositing surface (201) of which can be pivoted and displaced in one operation.

2. An auxiliary device as claimed in claim 1, characterised in that a delivery arm (50) is arranged in the V-shaped tip of the framework (41 to 44).

3. An auxiliary device as claimed in claim 2, characterised in that the delivery arm (50) is capable of being loaded in the vertical direction, but in the horizontal direction is designed to be flexible and displaceable.

4. An auxiliary device as claimed in claim 3, characterised in that the horizontal displacement path of the delivery arm (50) can be programme controlled.

5. An auxiliary device as claimed in claim 1, characterised in that the suction cups (51 to 66) can be separately activated as regards their connection to the suction line.

6. An auxiliary device as claimed in claim 5, characterised in that the activation of the suction cups (51 to 66) can be programme controlled.

7. An auxiliary device as claimed in claim 1, characterised in that the suction cups (51 to 66) are arranged to be mechanically or pneumatically displaceable in the horizontal direction on the carriers of the framework (41 to 43).

8. An auxiliary device as claimed in claim 7, characterised in that the displacement of the suction cups (61 to 64) on the carriers (41,42) can be programme controlled.

9. An auxiliary device as claimed in claim 2 or claim 3, characterised in that at least one independently activatable suction cup, and preferably two separately activatable suction cups (65,66), is or are arranged on the delivery arm (50).

10. An auxiliary device as claimed in claim 1, characterised in that the pivoting of the lifting table (20) can be programme controlled.

11. An auxiliary device as claimed in one of the preceding claims, characterised in that the gripping device (40) and the transport and depositing devices (15,20,25) form a joint handling system.

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