EP1631401B1 - Method and device for reshaping a work piece with automatic handling - Google Patents

Description

The invention relates to a method and an apparatus for forming a workpiece (see eg DE-A-25 54 277 ).

For industrial forging of workpieces, in particular beating, forming machines such as hammers, crank presses and screw presses, in particular flywheel spindle presses known. Beating forming machines comprise a working area in which two tools, generally rectilinear, are movable relative to each other. The workpiece is placed between the two tools and then reshaped by the impact or impact energy as the tools strike the workpiece and the forming energy caused thereby.

According to VDI-Lexikon " Production Technology Process Engineering ", publisher Prof. Dr. Hiersig, VDI-Verlag, 1995, pages 1107 to 1113 Divided forging hammers in Schabottehämmer, this in turn divided into hammers and Oberdruckhämmer, and counter-hammers. A scraper hammer comprises a scraper (or: a carrier, an anvil) as a tool fixed relative to the workpiece, and a striker or, in short, bears, relative to the workpiece and scraper, usually a vertical, moving tool. A counter-hammer has two against each other and in each case relative to the ground or the hammer frame, vertically or horizontally, moving striker on. The drives for the bears of blacksmith hammers are generally hydraulic or pneumatic. In the actual forming or working process, the hammer frame and the hammer drives of a forging hammer are relieved of the forming force, so that forging hammers are not overloaded. In the case of screw presses, the moving tool is usually called a ram. The plunger is moved rectilinearly to the stationary tool by a spindle. The drive of the spindle and thus of the tappet takes place (VDI-Lexikon a. A. O.) Via a drive motor and / or a flywheel as an energy storage

The forming pressure and the forming temperature depend on the material of which the workpiece is made, as well as on the requirements for dimensional accuracy and surface quality. Forgettable materials are basically all malleable metals and metal alloys, including both ferrous materials such as steels and non-ferrous metals such as magnesium, aluminum, titanium, copper, nickel and alloys thereof. The temperatures occurring during forging can be in the range of room temperature for a so-called cold forming, between 550 ° C. and 750 ° C. for a warm forging and above 900 ° C. for a so-called hot forming. The forming temperature is usually also placed in a temperature range in which the formability or flowability of the material required for forming is present as well as recovery and recrystallization processes can take place in the material and also undesirable phase transformations are avoided.

It is according to VDI-Lexikon " Produktionstechnik Verfabrenstechnik ", publisher Prof. Dr. Hiersig, VDI-Verlag, 1995, pages 848 and 849 as well as 1214 It is known to use handling devices such as manipulators and industrial robots for automated handling of workpieces during pressing or forging, having grippers for gripping and temporarily holding the workpieces and inserting or removing the workpieces from the forging machine. Manipulators are manually controlled moving devices with usually specific process-specific controls or programming. Industrial robots are universally applicable automatic movement machines with a sufficient number of degrees of freedom of movement, realized by a corresponding number (5 to 6) of axes of motion, and a freely programmable controller for the realization of virtually any movement trajectories of the workpiece within the movable or reachable by the industrial robot space area.

A problem with the use of such handling devices are the high impact forces in a beating forming machine, which can significantly burden and damage the handling device during forming blow when the handling device holds the workpiece when the bear or tappet blows.

To solve the problem of the reaction of the shock of the bear or plunger of the forming machine are in DE 42 20 796 A1 and DE 100 60 709 A1 Handling devices have been proposed, which can be made yielding during the impact for damping the transmitted from the workpiece impacts and vibrations towards the drive and which are made rigid during the transport of the workpiece.

Out DE 42 20 796 A1 a handling device for holding a forging in the forging process is known, in which a chassis carries a gripper device via a sleeve, which has a forging part during the forging gripping gripping tongs detected. The collar is hydraulically selectively in a yielding state and a rigid state brought.

Out DE 100 60 709 A1 is a trained as a manipulator or robotic handling device for handling a forged part in the forging process known with a grasping forceps and gripping tongs carrying the gripper arm, which is connected via a resilient block piece of an elastically deformable material with an arm portion which by means of a first electric motor and can swing from pivoting and can raise and lower by means of a second electric motor. These two movements of the arm area are synchronized by a control device. Due to the flexibility of the block piece, the front portion of the gripper with the gripper arm and the gripper tongs is pivotable relative to the rear portion with the arm portion and the drive motors in the block piece as a kind of hinge. Now, when the gripper sets a forging workpiece on a die of a forging hammer and the striker strikes the workpiece from above, vibrations or shocks generated thereby in the elastic block piece can be damped and trapped, so that the drives are relieved. For handling the workpiece before or after the actual forming process in the forging hammer, the elastic block piece is bridged by means of a Starrstellstange which establishes a rigid connection between the gripper arm and the arm portion over the block piece. The Strostellstange is fixed in parallel position of the front gripper arm and rear arm and detachable when the workpiece on the die of the forge hammer by lifting the rear arm area.

Problems in automated forging according to the prior art are workpieces which tend to kink, in particular elongated workpieces. The human is due to its motor sensitivity and experience also able to compensate for a bending of the workpiece during forging by handling or prevent, although he holds the workpiece only on one side. The known handling devices, however, do not allow automated forging, in which a bending of the workpiece can be safely avoided.

Finally, in the handling of forgings, there is a further problem that, due to manufacturing or machining tolerances in previous forming or forming steps, the forgings may in part have significant variations in shape, particularly at the ends gripped by the handling equipment , Therefore, it can come when gripping with the known automatic gripping devices to significant deviations of the position of the forging relative to the handling device and thus also relative to the tool of the forming machine, which can have a high rejection and in extreme cases even damage to the tools result.

The position of the workpiece in the tool of the forming machine could now be detected for example by an image recognition and the handling device can be controlled accordingly to correct a deviation of the position of the workpiece relative to the tool from a target position. However, this is quite expensive and functioning systems are not yet available for practical use.

Due to the above problems, automation of the handling of workpieces in forging processes with hitting forming machines has not been able to prevail in practice. Rather, in practice, the workpiece is still held manually by a human with a gripping tool in the forging hammer, as appropriate trained people master the correct handling of the workpiece when the bear strikes with the impact tool.

The invention is based on the object at least partially to reduce or completely avoid the above problems in the prior art.

This object is achieved according to the invention by a method having the features of claim 1 and a device having the features of claim 16.

Of course, the movement of the tools in the forming machine relative to each other involves both the case of only one of the two tools moving relative to the ground or machine frame or other external frame of reference and the other remaining fixed to that external system, such as a top hammer or a hammer Monkey or a screw press, as well as the case that both tools move relative to the external reference system, such as a counter-impact hammer. The forming position of the workpiece refers to its absolute and adjustable geometric position in space with respect to an external coordinate system. A change of the forming position is thus generally composed of translatory and / or rotational position changes or movements, ie the workpiece can be moved and / or rotated. The work area of the forming machine (s) is the area between the tools where the actual forming takes place. It can also be formed several work areas between two tools, which can be defined for example by different engravings in a die. When controlling the handling devices, the movement takes place in accordance with a predefined or predetermined movement sequence or movement profile or a corresponding stored control program (no feedback "open-loop-control"), while the movements of the handling devices are metrologically detected during the regulation and predetermined set movements (reference variables of the movement ) are adjusted or regulated (feedback, "closed-loop-control"). Automatically means that at least during the forming step itself no human intervention or holding the workpiece is required, but this is done automatically by the handling devices (or: automatic actuators) under control of the control device. Matched to each other are the movements or positions of the handling devices in order to be able to handle the workpiece exactly, in particular to hit it to be able to fix the forming machine in the forming position. So there is a kinematic coupling between the two handling devices provided when handling the workpiece during its transformation.

The invention is based on the idea of holding the workpiece at least during the impact of the impact tool or tools, the forming machine during the forming step at least two locations, each with an industrial robot or hold gripped.

This has the advantage that the workpiece is fixed at two points when the tool or tools (s) strike and thus can be more reliably prevented from jumping or slipping in the tools.

Another advantage is that kinking of a longer workpiece on one side can be prevented because the industrial robots can fix the workpiece on both sides and stabilize it during forming.

A particular advantage of the invention is the possibility of compensating a deviation of the position of the workpiece relative to the tools due to a corresponding deviation of the shape of a workpiece in an area in which a first attacks the industrial robot. This is accomplished by gripping and holding the workpiece in a second area by means of the second industrial robot. The workpiece is brought by the measures according to the invention between the two industrial robots in a kind of middle layer, while it is displaced or twisted when gripping with only one handling device as in the handling devices in the prior art due to the tolerances. In a manual handling of the workpiece by a human, this problem of prefabrication tolerances is not relevant because the human easily corrects a deviation of the position of the workpiece and inserts the workpiece correctly. An automatic correction of the position of the workpiece by the use of an automatic image recognition for determining the position of the workpiece is thus not required according to the invention. In the invention, deviations become mechanical, so to speak corrected by the two industrial robots force the workpiece by fixing or gripping in two places in the desired position, optionally with a corresponding deformation of the workpiece.

Advantageous embodiments and further developments of the method and the apparatus for forming a workpiece according to the invention will become apparent from the dependent claim 1 and claim 16 respectively dependent claims.

The kinematic coupling of industrial robots is realized electronically or control or control technology via a coupling of the control of their drive systems.

• Lüften des Werkstücks unmittelbar nach dem Umformstoß oder -schlag
• Umsetzen des Werkstücks von einem Arbeitsbereich einer Umformmaschine zu einem nächsten oder einer Gravur eines Werkzeugs zu einer nächsten oder von einer Umformlage zu einer nächsten
• Drehen oder Schwenken des Werkstücks, insbesondere zur Änderung einer Umformlage
• Umgreifen am Werkstück zur Berücksichtigung von dessen Gestaltänderung nach einem Umformschritt
• Aufnehmen des Werkstücks von einer Bereitstellungseinrichtung
• Transport des Werkstücks zur Umformmaschine oder von der Umformmaschine weg, insbesondere zu einer Ablage

In einer vorteilhaften Ausführungsform werden wenigstens bei einem Teil der Handhabungen des Werkstücks durch zwei Industrieroboter die beiden Industrieroboter synchron und/oder entlang zueinander im Wesentlichen konstant beabstandeter Trajektorien und/oder mit im Wesentlichen gleicher Geschwindigkeit bewegtIn addition to holding the workpiece during forming, the industrial robots can also carry out further manipulations, in particular one or more of the following manipulations:

• Ventilate the workpiece immediately after the forming bump or impact
• Conversion of the workpiece from one working area of a forming machine to a next or an engraving of a tool to a next or from one forming position to another
• Turning or pivoting of the workpiece, in particular for changing a forming position
• Encompassing the workpiece to account for the change in shape after a forming step
• Picking up the workpiece from a supply device
• Transport of the workpiece to the forming machine or away from the forming machine, in particular to a tray

In an advantageous embodiment, at least in a part of the manipulations of the workpiece by two industrial robots, the two industrial robots are moved synchronously and / or along substantially constantly spaced trajectories and / or at substantially the same speed

The control device controls or regulates the two handling devices, in particular their respective drive devices, in one embodiment according to a master-slave control principle, wherein an industrial robot serving as a slave follows an industrial robot serving as a master in the movements.

In an alternative preferred embodiment, the control device controls the two industrial robots, in particular their respective drive devices, independently of one another, with respective control sequences matched to one another.

In general, each industrial robot or its point of attack on the workpiece moves during a movement and / or handling of the workpiece along a previously determined trajectory with a predetermined speed profile and / or trailing consecutive trajectory points at regular time intervals.

The associated trajectory of the industrial robot or its point of application on the workpiece is preferably taught in advance, but can also be calculated or simulated.

In a particular embodiment, (only) the trajectory of one of the at least two industrial robots or its point of application is taught on the workpiece and the trajectory of the at least one other industrial robot or its point of attack on the workpiece is calculated in advance from the learned trajectory of the first industrial robot and stored or calculated in real time ,

When learning the trajectory of an industrial robot or its point of attack on the workpiece is generally the associated trajectory, traversed and at regular intervals, the trajectory points are sequentially recorded and stored. The speed course during training is preferably predetermined according to the later speed course in the process. With any velocity course during teach-in, the actual speed profile during operation can also be considered later and new trajectory points can be calculated and stored. The industrial robot or its point of attack on the workpiece during the movement and / or handling of the In any case, workpiece trajectory follows the trajectory points stored during teach-in, possibly after speed correction, at the same time intervals and in the same sequence as during teach-in.

During manipulations on the forming machine, the two industrial robots are preferably located on opposite sides of the working area or the tools of the forming machine. Furthermore, the industrial robots may preferably also be moved to a parking position in order to make the working area or areas of the forming machine (s) accessible

1. a) wenigstens eine Greifeinrichtung mit wenigstens zwei relativ zueinander bewegbaren Greifelementen zum Greifen des Werkstücks,
2. b) wenigstens eine Trägereinrichtung, an der die Greifeinrichtung befestigt oder befestigbar ist und
3. c) wenigstens eine Transporteinrichtung zum Transportieren der Trägereinrichtung mit der Greifeinrichtung

auf.In an advantageous embodiment of the device, each industrial robot

1. a) at least one gripping device with at least two gripping elements movable relative to one another for gripping the workpiece,
2. b) at least one carrier device to which the gripping device is attached or attachable and
3. c) at least one transport device for transporting the carrier device with the gripping device

on.

The device is now preferably developed by absorbing a flexible connection of carrier device and transport device in a flexible state at least partially shocks or vibrations that are transmitted during the forming process from the workpiece in the forming machine to the handling device, and thus protects the transport device from these mechanical loads and that a rigid connection or position of carrier and transport means in a rigid state, however, is used when handling the workpiece during transport or during rotation or pivoting before or after forming steps.

FIG 1

eine Vorrichtung mit zwei Industrieroboter beim Ergreifen eines Werkstücks in einer Seitenansicht,

FIG 2

die Vorrichtung gemäß FIG 1, bei der die zwei Industrieroboter das in eine Umformmaschine gelegte Werkstück halten, in einer Seitenansicht,

FIG 3

ein Querschnitt durch einer der Industrieroboter gemäß FIG 1 in der mit III-III bezeichneten Schnittebene und

FIG 4

ein Schnitt gemäß FIG 3 mit geschwenkter Greifeinrichtung bzw. Betätigungseinrichtung,

FIG 5

die Vorrichtung gemäß FIG 1 oder FIG 2, bei der die zwei Industrieroboter das in der Umformmaschine befindliche Werkstück nach dem Umformschlag lüften, in einer Seitenansicht,

FIG 6

eine Vorrichtung zum Umformen eines Werkstücks mit zwei Industrieroboter, die das Werkstück entlang vorgegebener Bewegungsbahnen handhaben, in einer schematischen perspektivischen Ansicht,

FIG 7

eine Vorrichtung zum Umformen eines Werkstücks mit zwei Industrieroboter bei einer Handhabung des Werkstücks in einer Draufsicht und

FIG 8

eine Vorrichtung zum Umformen eines Werkstücks mit zwei in Parkposition befindlichen Industrieroboter in einer Draufsicht

jeweils schematisch dargestellt sind. Einander entsprechende Größen und Teile sind in den FIG 1 bis 8 mit entsprechenden Bezugszeichen versehen.The invention will be explained below with reference to exemplary embodiments. Reference is made to the drawing, in whose

FIG. 1

a device with two industrial robots when gripping a workpiece in a side view,

FIG. 2

the device according to FIG. 1 in which the two industrial robots hold the workpiece placed in a forming machine, in a side view,

FIG. 3

a cross section through one of the industrial robot according to FIG. 1 in the sectional plane designated III-III and

FIG. 4

a cut according to FIG. 3 with pivoted gripping device or actuating device,

FIG. 5

the device according to FIG. 1 or FIG. 2 in which the two industrial robots ventilate the workpiece located in the forming machine after the forming stroke, in a side view,

FIG. 6

a device for forming a workpiece with two industrial robots, which handle the workpiece along predetermined trajectories, in a schematic perspective view,

FIG. 7

a device for forming a workpiece with two industrial robots in a handling of the workpiece in a plan view and

FIG. 8

a device for forming a workpiece with two in-park position industrial robot in a plan view

are each shown schematically. Corresponding sizes and parts are in the 1 to 8 provided with corresponding reference numerals.

There are a first industrial robot (also called first, handling device), with 2 and a second industrial robot (also called second handling device) designated 2 '. Each of the handling devices 2 and 2 'is an industrial robot. In the in 1 to 5 illustrated embodiments, the two handling devices 2 and 2 'formed substantially identical and each comprise a gripping device (or: gripper tongs) 3 and 3', a support shaft 4 and 4 ', a support means (or: rigid setting device) 5 and 5' , a bearing part 6 or 6 ', a flexible element 7 or 7', a pivot drive (or: rotary drive) 8 or 8 ', a joint 9 or 9', an actuating device 11 or 11 'and a transport device 16 or 16 '.

Each gripping device 3 or 3 'comprises two gripping levers 32 and 33 or 32' and 33 'each having an associated gripping jaw (or: gripping element, jaw jaw) 30, 31, 30' and 31 ', which by means of the actuating device 11 or 11 'to each other about a pivot axis E and E' in a pivot bearing 34 and 34 'are pivotable to open and close the gripping device 3 and 3'. The actuating device 11 or 11 'engages in an attack bearing 35 or 35' on the gripping lever 33 or 33 'and is in a pivot bearing 14 or 14' about a pivot axis D and D 'pivotally mounted on a holding part 61 and 61st 'of the bearing part 6 and 6' stored

The gripping lever 32 or 32 'of the gripping device 3 or 3' is connected via the carrier shaft 4 or 4 'with an intermediate part 60 or 60' of the bearing part 6 or 6 'coaxially along an axis M. Between the intermediate part 60 and 60 'and connected to the hinge 9 and 9' along a second axis N pivot drive 8 and 8 ', the flexible element 7 or 7' is arranged, and via a respective flange 67 and 87 or 67 'and 87' is connected to the intermediate part 60 or 60 'and the pivot drive 8 or 8' and consists of an elastic material, preferably an elastomer.

In the flexible element 7 or 7 'are now the front unit of the handling device 2 or 2', namely the gripping device 3 or 3 ', the support shaft 4 or 4' and the bearing part 6 or 6 'and the actuator 11th or 11 ', on the one hand and the rear unit of the handling device 2 or 2', namely the pivot drive 8 or 8 'and the hinge 9 or 9' and the transport device 16 or 16 ', and thus also their axes M and N mutually pivotable.

3 and 4 show in a sectional view through the lifting cylinder of the actuator 11 and the support shaft 4 and the support means 50 of the manipulator 2 according to FIG. 1 an embodiment of a pivoting movement.

FIG. 3 shows a vertical position in which a central axis B of the support member 50 of the support means 5 and a central axis C of the actuator 11 and the bearing part 6 coincide, the actuating device 11 is thus seen in the direction of gravity G above the intermediate part 60 of the bearing part 6 is arranged.

In FIG. 4 is now the front unit of the handling device 2 pivoted by a pivot angle β to the right in a clockwise direction or rotated. The carrier shaft 4 rotates about the rotation axis R in its support bearing 54 of the support means 5. The center axis C of the front unit, in particular the bearing part 6 and the actuator 11, and thus the gripping device 3 are now to the pivot angle β with respect to the central axis B of Supporting device 5 pivoted. This allows a workpiece 10 to rotate about the corresponding pivot angle β.

The support device 5 or 5 'of the handling devices 2 and 2' according to FIG. 1 and 2 comprises a longitudinal connecting rod 53 or 53 ', on which a transversely extending first fastening part 51 or 51' for connecting the connecting rod 53 or 53 'with the pivot drive 8 or 8' and further behind a transversely extending second Fastening part 52 or 52 'for connecting the connecting rod 53 or 53' with the joint 9 or 9 'and in the front region a transversely to the connecting rod 53 or 53' upwardly projecting support member 50 and 50 'for fixing or supporting the Carrier shaft 4 and 4 'are arranged. The support member 50 and 50 'has an incision as a support bearing (or: a shaft seat) 54 and 54' for the support shaft 4 and 4 '(see 3 and 4 ).

Im in FIG. 1 As shown, the handling devices 2 and 2 'are moved from both sides onto a workpiece 10 or 10' in the direction of the illustrated arrows, the axes M and N being coaxial and horizontal, ie perpendicular to the gravitational force G, and the flexible one Element 7 or 7 'is substantially undeformed. The connecting rod 53 or 53 'now extends parallel to the axes M and N and the support member 50 and 50' supports the support shaft 4 and 4 'and thus the associated gripping device 3 and 3' in its support bearing 54 and 54 'down. The support device 5 or 5 'thus represents a mechanical bridging over the flexible element 7 or 7' and thus eliminates in the position according to FIG. 1 the flexibility of the handling device 2 or 2 'in the flexible element 7 and 7 'at least in the spatial direction of gravity G and in the downward lateral directions between the gravity G and the horizontal direction. The rigid connection is maintained solely by the weight of the parts of the handling device 2 and 2 '. The gripping devices 3 and 3 'are in their vertical positions and are open.

Upon reaching the workpiece 10, the gripping means 3 and 3 'are closed and thus the workpiece 10 is gripped at its ends 10A and 10B and transported by the transport means 16 and 16' to a forming machine and placed there in the forming position for forming on a tool. In this case, the handling device 2 or 2 'is held in a rigid state via the support device 5 or 5'.

FIG. 2 shows the workpiece 10 in the mounted state on the lower tool or die 12 of a forging hammer. By lifting the rear units of the handling devices 2 and 2 ', ie tilting the central axis N or N' of pivot drive 8 or 8 'and hinge 9 or 9' by the inclination angle α relative to the central axis M and M 'of the front unit around the flexible element 7 or 7 ', the support means 5 or 5' out of engagement with the support shaft 4 or 4 'is introduced, since the support means 5 and 5' with the pivot drive 8 and 8 'and the joint 9 and 9 'along the axis N and N' remains aligned and thus the support member 50 and 50 'is sufficiently removed from the support shaft 4 and 4'. In the tilting movement about the angle α or α 'while the die 12 serves over the workpiece 10 as an abutment.

The striking tool 13 now strikes the workpiece 10 in the direction of impact A. The impact movement produces considerable impact and vibration loads, which are transmitted via the workpiece 10 to the handling devices 2 and 2 '. However, the elastic elements 7 and 7 'now decouple these shocks or vibration largely from the transport device 16 or 16' and the pivot drive 8 or 8 ', so that these drive devices are protected against overloading.

Depending on the workpiece 10 and the desired forming process, however, it may be necessary in many forming processes to rotate the workpiece 10 prior to placement on the die 12, in particular about an axis of rotation extending through the workpiece 10, for example its longitudinal axis. For such a pivotal movement, the gripping means 3 and 3 'are engaged with the gripped workpiece 10 in the supported state, i. when in support of the support shaft 4 located support means 5 to the desired pivot angle β in the same direction of rotation and at the same rotational or angular speed pivoted to rotate the workpiece without torsion in its desired forming position. For this purpose, a rotational movement of an output shaft of a in the drive housing 80 or 80 'of the rotary actuator 8 and 8' arranged drive motor, possibly via a transmission, via the drive flange 87 and 87 'and the flexible member 7 and 7' on the Connecting flange 65 and 65 'transmitted, which in turn rotates the intermediate part 60 and 60', the support shaft 4 and 4 'and the gripping device 3 and 3'. The rotation of the gripping means 3 and 3 'may be omitted if rotation is not desired.

FIG. 5 shows, starting from FIG. 2 , The situation shortly after the striking tool 13 strikes the workpiece 10 and the surrounding areas of the tool 12. The impact tool 13 is again in a direction away from the tool 12 upward movement in a return direction RH by the recoil and possibly by a drive. Now, the workpiece 10 is raised or released by the tool 12 by a distance d. This release movement of the two handling devices 2 and 2 'and the workpiece 10 held by them thus follows the upwardly moving impact tool 13 in the same direction as the return direction RH. The handling devices 2 and 2 'remain in the rule in the flexible position, as in FIG. 5 shown. During or after this release movement, scale material is blown out of the lower die 12 by means of a blower. The venting also shortens the contact time of the workpiece 10 with the lower die or die 12.

After the venting process, either the workpiece 10 can now be placed again on the tool 12 or on another die or another engraving of the tool 12 and be reshaped with the striking tool 13. But it can also be completed the forming process and the workpiece 10 from the in FIG. 5 shown ventilated position of the two handling devices 2 and 2 'moved out of the work area of the forming machine between the two tools 12 and 13 and transported to a storage device.

FIG. 6 shows an embodiment of a handling of a workpiece 10 with two handling devices 2 and 2 ', starting from the recording on a supply device 41 to laying on a tool 12 of a hitting forming machine. The trajectories or trajectories of the two handling devices 2 and 2 'are denoted by S and S', the directions of movement are indicated by arrows.

The two handling devices 2 and 2 'are each started at a time t0 from a parking or starting position S (t0) and S' (t0) and move toward the workpiece 10 on the supply device 41. At a time ti, the handling devices 2 and 2 'respectively reach the ends 10A and 10B of the workpiece 10 at the respective positions S (ti) and S' (ti). Now, the gripping devices 3 and 3 'grip the respective end 10A and 10B of the workpiece 10 and the handling devices 2 and 2' now transport the workpiece 10 along the trajectories S and S '. The two trajectories S and S 'run parallel to each other and the handling devices 2 and 2' are moved synchronously with each other. As a result, the workpiece 10 is moved substantially only translationally and not rotationally. At any given time tj, the difference vector Δ = S '(tj) -S (tj) is always the same. Towards the end of the trajectories S and S ', the handling devices 2 and 2' introduce the workpiece 10 into the working area between the tools 12 and 13 of the striking forming machine and move the workpiece 10 down to a predetermined forming position on the tool 12 to an end position S. (tn) for the handling device 2 and S '(tn) for the handling device 2' at an end time tn on opposite sides of the working area or tool 12 of the forming machine. The dashed workpiece 10 is now in the forming position on the tool 12 and can be reshaped.

During forming, the handling devices 2 and 2 ', which are likewise indicated by dashed lines, hold the ends 10A and 10B of the workpiece 10 firmly again. After forming the workpiece 10 by impact or impact of the striking tool 13 on the workpiece 10 can now as in FIG. 5 a release movement by the handling devices 2 and 2 'take place. Furthermore, the workpiece 10 can additionally or alternatively be implemented by being engraved from one tool into another or also from the forming machine to a depositing or discharging device.

The tools 12 and 13 are according to the invention forming tools, so-called dies with corresponding to the desired shape of the workpiece adapted engravings. The handling devices generally hold the workpiece 10 throughout the forging cycle and perform all of the handling movements necessary for the forging process jointly and synchronously. As handling movements are, inter alia, Lüftbewegungen within an engraving and Umsetzbewegungen of the feeder in the first engraving of the die, Umsetzbewegungen between engravings of Gesenkes and Umsetzbewegungen of an engraving of Gesenkes in a discharge device.

Furthermore, workpieces are preferably also forged whose ends, on which the handling devices hold the workpiece during handling, are not symmetrical to the workpiece axis. These workpieces are stretched in previous steps, wherein it happens that the ends of the workpiece are formed asymmetrically. As a result of the workpiece 10 being grasped at both ends 10A and 10B by a respective handling device 2 and 2 ', the workpiece 10 is aligned automatically, so that the workpiece 10 is placed in its correct position in the engraving or the tool 12.

The common and synchronous driving of the two handling devices 2 and 2 'is achieved via an electrical coupling between the two handling devices 2 and 2', wherein the coupling via the master-slave operation of electric drives or by the simultaneous start of independently operating drives is achieved. The start signal for the individual handling steps is supplied by a control device which controls the sequence between the beating forming machine and the two handling devices 2 and 2 '. This control device can additionally carry out the complete signal exchange. In general, the control device operates by means of at least one digital processor, in particular a microprocessor or a digital signal processor, and corresponding memory in which the sequence programs, control algorithms and data for the movements are stored. For a master-slave operation known per se master-slave control units can be used. For independently operating drives, the same distances and speeds as well as error feedback and error responses between the independent drives are provided in order to ensure an exact and in case of failure safe operation.

In a typical forging cycle, a workpiece is fed by means of a feeder or providing device. Subsequently, both handling devices 2 and 2 'grip the workpiece 10 and insert the workpiece 10 together and synchronously into an engraving of the die of the striking die-forming machine. Now, the beating die-forming machine is triggered at a variable time during or at the end of the handling movement and after triggering the further handling of the workpiece is initiated at a variable time during or at the end of the impact movement. This further handling is again together and synchronously by both handling devices 2 and 2 'and may be a release movement of the workpiece in the same engraving, a common and synchronous conversion of the workpiece in a further engraving or the common and synchronous transfer of the workpiece in a storage device for the finished formed workpiece.

If the workpiece 10 is designed such that the first handling and forging steps can be carried out with only one handling device, the second handling device 2 'also grips the workpiece 10 at a later time of the forging cycle and both handling devices 2 and 2' forge from this point in time together and in sync like already described. The partial reacting or forging with only one handling device is particularly useful when more than two handling devices are used, since this or the other handling devices already pick up a new workpiece and possibly even forge if the other two handling devices forge the previous forging finished or insert into a discharge device. By this design with at least three handling devices shorter cycle times can be realized.

FIG. 7 shows another embodiment of an apparatus for handling a workpiece during a forging process. This device again comprises two industrial robots 2 and 2 'with respective gripping devices 3 and 3'. The two industrial robots (also called handling devices) 2 and 2 'receive a workpiece 10 from a supply device 41, for example a feed conveyor belt or other automated feeder, and place the workpiece in a first engraving 17 of a tool 12 of a punching die forming machine. The counter tool or impact tool of this die-forming machine is not shown and would be in the illustrated plan above the plane of the drawing. During or at the end of the handling movement or transfer movement of the supply device 41 in the first engraving 17 of the tool 12, the impact tool of the forming machine is triggered. After the shock release, a new sequence for the further handling of the workpiece 10 is initiated by a time during or at the end of the impact movement of the impact tool. First, the workpiece 10 is fixed in its forming position on the engraving 17 of the two handling devices 2 and 2 'to the impact and during the impact of the impact tool and held at both ends. After striking and releasing the impact tool from the workpiece 10, the workpiece 10 is handled jointly and synchronously by the two handling devices 2 and 2 'according to the stored further handling routine. First, the workpiece 10 is released, as indicated by FIG. 5 already explained, and then either processed again in the first engraving 17 or immediately implemented in the second engraving 18 of the tool 12. After the conversion of the workpiece 10 in the second engraving 18 is again a forming step with triggering of the forming machine and its impact tool at a variable time during or at the end of the handling movement between the first engraving 17 and the second engraving 18. After the shock release is again the other common synchronous handling of the workpiece 10 at an adjustable time during or at the end of Impact movement initiated. It can now again together and synchronously the workpiece from the two handling devices 2 and 2 'are released in the second engraving 18 and possibly re-inserted into the engraving 18 for a repeated processing or the workpiece 10 can equal to the storage device 42 for the finished formed workpiece 10 are implemented.

FIG. 8 shows a park or rest position of the two handling devices 2 and 2 'in a device according to FIG. 7 , In the parking position of the handling devices access to the tools 12 and 13 of the forming machine for tool change, for post-processing or for a manual test operation of the beating forming machine is possible.

The movement of the handling devices 2 and 2 'and thus the handling movements for the workpiece 10 are usually taught. For this purpose, in a teach-in process, the workpiece 10 with the two handling devices 2 and 2 'guided along the intended trajectory and possibly rotational movements and the individual space points or the corresponding motion parameters in the motion system of the handling devices 2 and 2' are at regular intervals, typically 16 ms, saved. In the embodiment of FIG. 6 For example, the trajectors S and S 'of the handling devices 2 and 2' are each in the form of discrete data sets which each belong to a point on the trajectories, starting from the track points S (t0) and S '(t0) via S (ti). or S '(ti), S (tj) or S' (tj) up to the end point S (tn) or S '(tn). In the later process, the movement is guided along the stored trajectories S and S '.

If the real speed profile was already set during the teach-in process, then the spatial points S (tm) and S '(tm) detected during the learning process can be used for 0 ≤ m ≤ n directly by stepping off the Time points t0 to tn in the predetermined time intervals .DELTA.t = tm + 1 - tm of, for example, 16 ms are traversed. If the speed profile during the learning process does not correspond to the actual later speed profile, then the path points stored during the learning process are converted by a corresponding transformation or mapping into the path points intended for the later process. This way of learning robot motions is known per se and therefore does not require any more detailed descriptions.

Instead of guiding a reference workpiece during the teaching process with both handling devices 2 and 2 ', only the movement of one of the handling devices 2 or 2' can be taught and the movement of the other because of the coordinated and usually synchronous movement of the handling devices 2 and 2 Handling device 2 'or 2 are adapted to the movement of the taught handling device.

This can be achieved, in particular, by a master-slave operation in which, in particular, the second, non-trained handling device follows the movements of the taught-in handling device step by step.

Alternatively, for the parts of the handling movements in which the two handling devices 2 and 2 'are moved synchronously and jointly, for example as in the embodiment of FIG FIG. 6 , only a handling device, such as the handling device 2, are taught and the associated movement trajectory S or, more generally, the associated movement, which can be composed of translational and rotational movements, are stored and then by a simple translation mapping on the translation vector Δ according to FIG. 6 the trajectory S 'of the second handling device 2' are calculated. Thus, the handling devices 2 and 2 'may have independent drive systems and control systems from the hardware, but are electrically or electronically coupled by the mismatched control programs and operations that enable the synchronous movements. This embodiment has the advantage over a master-slave operation that there is no following error between the two handling devices 2 and 2 ' the stepwise succession as in the master-slave operation more arises, but the two handling devices 2 and 2 'are at each time tm on mutually synchronous or parallel track points.

For the handling devices 2 and 2 'can in addition to the basis of the 1 to 4 described embodiments, other industrial robots are used, preferably a good damping of the movement joints and other movement mechanisms is provided to relieve the drives of the recoil and the vibrations when hitting the impact tool of the forming machine. For example, the handling devices mentioned in accordance with DE 42 20 796 A1 or DE 100 60 709 A1 used as long as they are industrial robots.

In addition to the described handling movements, additional or alternative handling movements may also be provided by the handling devices 2 and 2 'with or without a workpiece 10.

The distance between the gripping devices, for example the distance vector Δ in FIG. 6 , is usually dependent on the length or along this distance measured dimension of the workpiece and remains constant during the synchronous common handling usually.

But it can also be a volume or shape change of the workpiece after the forming process, in particular an elongation of the workpiece, are taken into account by the handling devices 2 and 2 'change their points of attack on the workpiece, for example, on the outside of an elongation of the workpiece. For this purpose, in particular the gripping pressure of the gripping devices 3 and 3 'can be reduced and - without letting go or open the gripping devices 3 and 3' - the gripping devices 3 and 3 'of the handling devices 2 and 2' can be pulled further outwards along the workpiece 10

Furthermore, the movement trajectories of the two handling devices can also deviate from each other in an adapted manner, for example in an offset or a correction, for example if the Workpieces have different burrs or other different shape at the attack areas.

In another embodiment, it is possible, instead of a learning process, to use an industrial robot with a specifically controllable movement course within a spatial region that can be reached by it, ie the transformation description in its three-dimensional coordinate system allows any movement within the spatial region without first traversing the movement to have. This can be done in particular in the context of a 3-D simulation.

The workpiece can also be rotated about an axis of rotation, in particular with the aid of the 1 to 4 described embodiments of the handling devices. Furthermore, of course, rotary movements or portions of rotational movements for transporting the workpiece 10 are possible, for example, to pass through narrow areas on the transport path.

The error communication about the in FIGS. 7 and 8 shown control device makes it possible to interrupt the process in an impermissible deviation of the handling devices of the prescribed trajectory at a certain time, especially to stop the handling equipment.

LIST OF REFERENCE NUMBERS

2, 2 '

Industrial robot, also called handling device.

3, 3 '

gripper

4, 4 '

carrier wave

5, 5 '

support means

6, 6 '

bearing part

7, 7 '

flexible element

8, 8 '

rotary drive

9, 9 '

joint

10

workpiece

11, 11 '

actuator

12

die

13

impact tool

14, 14 '

pivot bearing

15, 15 '

lifting cylinder

16, 16 '

transport means

17, 18

engraving

30, 31, 30 ', 31'

jaw

32, 33, 32 ', 33'

gripping levers

34, 34 '

pivot bearing

35, 35 '

Angreiflager

41

Providing device

42

Bin Setup

43

control device

50, 50 '

supporting part

51, 52, 51 ', 52'

attachment portion

53, 53 '

connecting rod

54, 54 '

support bearings

60, 60 '

intermediate part

61, 61 '

holding part

65, 65 '

connecting flange

80, 80 '

drive housing

87, 87 '

drive flange

M

front axle

N

rear axle

A

impact direction

B, C

axis

D, E

swivel axis

F

swivel axis

G

gravity

R

axis of rotation

Claims (20)

1. Method for forming at least one workpiece, wherein

   a) the workpiece (10) is positioned in a predefined or predefinable forming position in at least one working area of at least one percussive forming machine, namely a forging hammer or a screw press or a crank press, between two associated tools (12, 13), which are forming die tools for the closed forming of the workpiece, wherein the workpiece lies in its forming position in or on one of the tools of the forming machine or is laid in its forming position in or on the tool,

   b) the tools of the forming machine are moved relative to each other and the workpiece is formed between the tools during at least one forming step,

   c) the workpiece is held securely in its forming position by at least two handling devices (2, 2') during each forming step,

   d) wherein the movements and positions of the handling devices are controlled or regulated automatically and in coordination with each other by at least one control device (43),

   e) wherein the handling devices are industrial robots.
2. Method according to Claim 1, wherein the workpiece is formed in at least two forming steps in the same working area and/or the same forming position and/or in different working areas of one or more forming machines and/or in different forming positions.
3. Method according to Claim 2, wherein the workpiece moves between two successive forming steps of at least one handling device from one working area to the next working area or, rather, from one forming position to the next forming position and is positioned in this forming position, in particular is rotated between one forming position and the next forming position, preferably around an axis of rotation running through the workpiece, in particular around an angle of rotation of approximately 90°.
4. Method according to one of the previous claims, wherein each workpiece is transported prior to the forming step or the first forming step by at least one handling device from a supply device to the or the first, working area of the forming machine(s) and/or wherein each workpiece is transported after the forming step or after the last forming step by at least one handling device from the working area or, rather, the last working area of the forming machine(s) to a set-down device.
5. Method according to one of the previous claims, wherein the workpiece is positioned in the or each forming position or at least one of the forming positions by at least two handling devices and preferably is both positioned in the forming position and held securely during the at least one forming step by the same two handling devices and/or is both transported from the supply device to the, or rather the first, working area of the forming machine(s) and is positioned in the respective forming position by the same two handling devices and/or is both positioned in the, or rather the last, forming position and transported from the working area or, rather, the last working area of the forming machine(s) to a set-down device by the same two handling devices and/or is both positioned in each of the forming positions and held in each of the forming positions as well as moved between the forming positions by the same two handling devices.
6. Method according to one of the previous claims, wherein the at least two handling devices lift or raise the workpiece from the tool or tools after the striking of the tools and/or during a relative movement of the tools away from each other.
7. Method according to one of the previous claims, wherein the handling devices continually keep the workpiece gripped during the handling or moving of the latter and/or the workpiece is held, at least during each forming step, on sides or ends facing away from each other, in each case by a handling device.
8. Method according to one of the previous claims, wherein, during a movement and/or handling of the workpiece by at least two handling devices, the handling devices or their points of contact along the workpiece are moved at trajectories S(t0) essentially constantly spaced in relation to each other and/or wherein, during a movement and/or handling of the workpiece by at least two handling devices, the handling devices or their points of contact on the workpiece are moved synchronously in relation to each other and/or wherein, during a movement of the workpiece by at least two handling devices, the handling devices or their points of contact on the workpiece are moved at essentially the same speed and/or wherein, during handling of the workpiece by at least two handling devices, the handling devices essentially pick up or release the workpiece.
9. Method according to one of the previous claims, wherein, to move and/or handle the workpiece by at least two handling devices, the control device actuates the two handling devices, in particular their respective drive devices, according to a master-slave control principle, wherein a handling device serving as the slave follows a handling device serving as the master in its movements.
10. Method according to one of the previous claims, wherein, to move and/or handle the workpiece by at least two handling devices, the control device actuates the two handling devices, in particular their respective drive devices, independently of each other.
11. Method according to one of the previous claims, wherein each handling device or its point of contact on the workpiece during a movement and/or handling of the workpiece follows a predetermined trajectory with a predefined speed variation and/or wherein the handling device or its point of contact on the workpiece during a movement and/or handling of the workpiece follows stored successive trajectory points at regular intervals, which preferably are between 1 ms and 50 ms, in particular 16 ms.
12. Method according to Claim 11, wherein for at least one handling device, for each movement and/or handling of the workpiece by this handling device, the associated trajectory of the handling device or its point of contact on the workpiece is or has been pre-programmed, wherein in particular the trajectory of one of the at least two handling devices or its point of contact on the workpiece, is or has been computationally determined from the pre-programmed trajectory of the first handling device and/or wherein in particular, for programming the trajectory of a handling device or its point of contact on the workpiece, the relevant trajectory is or has been traced with a predefined speed variation and the trajectory points are or have been detected and stored in succession at regular intervals or wherein in particular, for programming the trajectory of a handling device or its point of contact on the workpiece, the relevant trajectory is or has been traced and the trajectory points are or have been detected and stored in succession at regular intervals, and new trajectory points are calculated from these trajectory points and from a predefined subsequent speed variation, wherein in particular the handling device or its point of contact on the workpiece with the movement and/or handling of the workpiece follows the trajectory points that have been stored on programming, at the same intervals and in the same sequence as the programming.
13. Method according to one of the previous claims, wherein the handling and/or movements of the handling devices are calculated directly in a three-dimensional system of coordinates and/or are generated and stored by simulation or the like.
14. Method according to one of the previous claims, wherein it is verified in safety stages whether the handling device or handling devices maintain their movement and/or position predetermined by the control device and the movement of the handling devices is stopped with any improper deviation, and/or wherein the handling devices can be moved or are moved into a parked position in order to make the working area(s) of the forming machine(s) accessible.
15. Method according to one of the previous claims, wherein the at least two handling devices become or are arranged or positioned on opposing sides of the working area of the forming machine, at least when holding the workpiece securely during a forming step.
16. Device for forming at least one workpiece, in particular for use in a method according to one of the Claims 1 to 15 or for carrying out a method according to one of the Claims 1 to 15, comprising

    a) at least one percussive forming machine, in particular a forging hammer or a screw press or a crank press, with at least two tools (12, 13) which can be moved relative to each other for shaping a workpiece and which are forming die tools for the closed forming of the workpiece in a predefined or predefinable forming position during at least one forming step,

    b) at least two handling devices for holding the workpiece securely in the forming position during the forming step,

    c) at least one control device for controlling or regulating the movements and positions of the handling devices,

    d) wherein the handling devices are industrial robots.
17. Device according to Claim 16, wherein the handling devices each have at least one drive device in each case with at least one electrical drive motor and the control device actuates each drive device or wherein at least two handling devices are driven by at least one common drive device with at least one electrical drive motor and the control device actuates the common drive device.
18. Device according to Claim 16 or Claim 17, wherein each handling device comprises

    a) at least one gripping device with at least two gripping elements that can be moved relative to each other for gripping the workpiece,

    b) at least one carrier device, to which the gripping device is or can be attached, and

    c) at least one transport device for transporting the carrier device with the gripping device.
19. Device according to Claim 18, wherein the carrier device and the transport device are flexibly connected to each other in a flexible state and are essentially rigidly connected to each other in a rigid state, at least in one direction in space and/or in each rotational position of the gripping device and/or the gripping element or gripping elements, in that either the carrier device and the transport device are connected to each other by means of at least one connecting element that is flexible in the flexible state and rigid in the rigid state or the carrier device and the transport device are connected to each other by means of at least one flexible element, and are only connected by means of the flexible element in the flexible state, and in the rigid state are essentially braced together or against each other by means of at least one supporting device bridging the flexible element.
20. Device according to Claim 18 or Claim 19, wherein each handling device comprises at least one rotation drive for turning the gripping device around an axis of rotation running through the gripping device and/or for turning at least one of the gripping elements around an axis of rotation running through the gripping element, wherein the at least one rotation drive for turning the gripping device is preferably arranged on the side of the connecting element or the flexible element facing away from the gripping device and the carrier device.

Images