EP3448595B1 - Transporting device for transferring workpieces in a processing facility - Google Patents

Description

The present invention relates to a transport device for transferring workpieces in a machining device comprising at least two stages, in particular in a shaping device, according to the preamble of patent claim 1, and to a machining device equipped with a corresponding transport device, in particular shaping device, according to the preamble of patent claim 16.

In the case of massive forming and also in the case of other forming processes or machining processes in general, workpieces often pass through several stages of a machining device in succession, the workpieces being transported from stage to stage. In a forming device, the stages are typically a charging stage and various forming stages. To transport the workpieces from stage to stage, transport devices equipped with pliers-like gripping tools and working in the machine cycle of the processing device are generally used, the gripping tools simultaneously gripping the workpieces, taking them out of one stage and feeding them to the next stage where they release them.

In the known processing devices, in particular forming devices, the transport movements and the actuation of the gripping tools are coupled to the drive train of the processing device - see, for example, the CH 595 155 A .

The US 6 371 544 B1 discloses transport devices for moving workpieces in forging machines with a plurality of gripping tools for gripping one workpiece each, which are arranged on a gripping tool carrier. The gripping tool carrier is pivotally mounted via several rotatable coupling elements and can be moved back and forth by means of a drive mechanism. The drive mechanism is not described in detail.

A generic transport device for moving workpieces in a forming device is in the EP 1 048 372 B1 described. In this known transport device, a plurality of gripping tools designed as gripping tongs, each with its own gripping tool drive, decoupled from the drive train of the shaping device, are arranged on a common pliers carrier movable in the longitudinal direction and transversely to this, by means of which all gripping tongs jointly between two adjacent stages of a shaping device and be transported here. The gripping tongs comprise two swivel arms which are driven by a servo motor to be pivoted towards and away from one another via kinematic coupling members. The EP 1 048 372 B1 essentially deals with the design of the gripping tongs and their drives, the drive of the tongs carrier for carrying out the transfer movements of the gripping tongs is not specifically described.

In forming devices, especially hot-forming devices, the raw material is usually fed in rod form, from which pieces of the required length are then cut off. The bar ends and bar beginnings must not get into the forming process and must be eliminated. These separated sections are missing in the forming process and generate individual empty forming steps in the forming device. Due to the lack of forming force there, the deformation of the machine body changes, which has a negative effect on the geometry of the formed parts. Depending on the requirements, such parts can then not be used and must be sorted out of the finished parts manually or removed using suitable switches. Since the mechanical rejection is not so precise, good formed parts may also be rejected. In addition, an empty forming stage is cooled more strongly by cooling water, which has a negative effect on the wear of the forming tools. This problem is eg in the EP 1 848 556 B1 explained in detail.

Another problem with conventional transport devices is that in the event of process malfunctions, e.g. due to empty gripping tools or incorrectly inserted workpieces or damaged parts such as e.g. torn gripping tools or broken press punches etc. are caused, cannot be reacted to immediately and therefore workpieces are not deformed as desired or there can often even be considerable consequential damage to the transport device or the processing device.

Against this background, the invention has for its object a transport device of the type mentioned and one with such Processing device equipped transport device, in particular a forming device, to improve that on the one hand individual empty processing steps can be avoided and on the other hand it is easy to react to process faults.

This object is achieved by the transport device according to the invention and the processing device according to the invention as defined in independent claim 1 and in independent claim 16. Particularly advantageous developments and refinements of the invention result from the respective dependent patent claims.

With regard to the transport device, the essence of the invention is as follows: A transport device for transferring workpieces in a processing device comprising at least two stages, in particular in a forming device, comprises at least two gripping tools for gripping one workpiece each, which gripping tools at one between the stages of the processing device - And moving movable gripping tool carrier are arranged. The gripping tool carrier is mounted on the one hand in a linearly guided manner and on the other hand is mounted so that it can be deflected transversely to its linearly guided mobility. For the linearly guided movement and transverse deflection of the gripping tool carrier, the transport device comprises a gripping tool carrier drive with at least one gripping tool carrier drive motor.

The transport device is decoupled from the drive train of the processing device by the at least one separate gripping tool carrier drive motor. Due to the decoupling and the deflectability of the gripping tool carrier transversely to its linear back and forth movement, the gripping tool carrier can be quickly moved into a safe position in the event of a fault.

The transport device preferably has a parallelogram guide arrangement for deflecting the gripping tool carrier transversely to its linearly guided mobility. As a result, the gripping tool carrier only makes a small movement perpendicular to the direction of deflection when it is deflected.

According to an advantageous embodiment, the gripping tool carrier drive comprises two crank gear arrangements, each with an associated gripping tool carrier drive motor, each crank gear arrangement having a crank which can be rotatably driven by the associated gripping tool carrier drive motor and a drive rod which is articulated to the crank on the one hand and the gripping tool carrier on the other.

The kinematic coupling of the gripping tool carrier with the gripping tool carrier drive motors via two crank gear arrangements allows simple control of the movement sequences solely by correspondingly controlling the gripping tool carrier drive motors.

The gripping tool carrier drive motor or the gripping tool carrier drive motors are advantageously servomotors with rotary encoders. This allows simple control of the motion sequences.

According to an advantageous embodiment, the gripping tool carrier can be moved with the gripping tools by means of the gripping tool carrier drive in a forward movement along a first linear movement path and in a return movement along a second linear movement path parallel to the first linear movement path. Due to the distance between the two linear trajectories, the gripping tools can easily be kept out of the effective range of processing tools in the stages of the processing device, at least during one movement.

The gripping tool carrier is expediently slidably mounted on at least two guide rods. This represents a particularly simple implementation of the linearly guided displaceability of the gripping tool carrier.

Advantageously, the parallelogram guide arrangement comprises at least two links, which on the one hand are slidably mounted on one of the guide rods in the longitudinal direction thereof and pivotable about them, and on the other hand are articulated with the Gripping tool carriers are connected. As a result of this measure, the gripping tool carrier can be moved both linearly and transversely in a structurally simple manner.

The transport device expediently has a carrier control for the gripping tool carrier drive motors, which is designed to control the movement of the gripping tool carrier. As a result, the movement sequences of the gripping tool carrier can be implemented in a simple manner and, if necessary, adapted.

Advantageously, the carrier control is designed to move the gripping tool carrier with the gripping tools into a waiting position and to interrupt the transport of the workpieces, in particular on the basis of a control command supplied to it. In this way, the workpiece transport can be interrupted automatically when a process malfunction occurs and the gripping tool carrier with the gripping tools can be moved into a safe position.

According to an advantageous development, the gripping tools are each assigned a gripping tool drive, preferably arranged on the gripping tool carrier, for the individual actuation of the gripping tools for gripping or releasing a workpiece. This means that each gripping tool can be individually set and operated.

Very particularly advantageously, the gripping tools are designed as gripping tongs and the gripping tongs each have two tong arms which can be moved linearly towards and away from one another. This prevents errors when gripping the workpieces.

The tong arms are expediently arranged on a tong slide which is slidably mounted in a tong body, the tong slides being kinematically connected to a toothed rack and the toothed racks being in engagement with a motor-driven drive pinion, the tong slides and so that the tong arms can be moved in opposite directions by means of the drive pinion. This represents a structurally simple realization of the linear mobility of the gun arms.

The tong arms are advantageously arranged on the tong carriage in such a way that they can be adjusted relative to them. This allows the gun arms to be easily adapted to workpieces.

The gripping tool drives are expediently assigned a gripping tool control which is designed to individually control the opening and closing movements and preferably also the clamping force of the individual gripping tools. This allows an optimal adaptation to the respective requirements.

The gripping tool control is particularly advantageously designed to e.g. to detect a process disturbance caused by an empty gripping tool or an incorrectly inserted workpiece into the gripping tool and to signal it to the carrier control so that it can move the gripping tool carrier into a waiting position, for example. This training enables process faults to be recognized at an early stage and consequential consequential damage or workpieces that have not been deformed as desired can be largely avoided.

With regard to the machining device, the essence of the invention is as follows: A machining device, in particular a shaping device, comprises at least two successive stages and a transport device of the type described above for moving workpieces between the stages of the machining device.

The processing device advantageously has a carrier control for the gripping tool carrier drive motors, which is designed to control the movement of the gripping tool carrier and, in particular, on the basis of a control command supplied to it, the gripping tool carrier with the gripping tools in a waiting position in which the gripping tools are outside the effective range of processing tools of the stages the processing device move and interrupt the transport of the workpieces. In this way, the workpiece transport can be interrupted automatically when a process malfunction occurs and the gripping tool carrier with the gripping tools can be moved into a safe position.

The first stage of the successive stages of the machining device is expediently a loading stage and the carrier control is designed to move the gripping tool carrier with the gripping tools into the waiting position if there is a process disturbance due to a non-editable or missing workpiece in the loading stage. In this way, empty steps of the processing device can be avoided.

The processing device advantageously has a sensor device, which interacts with the carrier control for the gripping tool carrier drive motors, for detecting the process fault and for signaling the same to the carrier control. This allows the gripping tool holder to be moved automatically into the waiting position in the event of a process malfunction caused by a workpiece that cannot be machined or is missing in the loading stage.

The carrier control is expediently designed to move the gripping tool carrier with the gripping tools out of the waiting position after the process disruption and to restart the transport of the workpieces.

Figuren 1-6 -

schematische Ansichten und Schnittdarstellungen der Bearbeitungseinrichtung in verschiedenen Phasen eines Arbeitsablaufs;

Fig. 7 -

eine perspektivische Gesamtansicht der Transportvorrichtung der Bearbeitungseinrichtung gemäss den Figuren 1-6;

Fig. 8 -

eine Frontalansicht der Transportvorrichtung;

Fig. 9 -

eine Seitenansicht der Transportvorrichtung;

Fig. 10 -

einen Schnitt durch die Transportvorrichtung gemäss der Linie X-X der Fig. 9;

Fig. 11 -

eine perspektivische Darstellung einer Greifwerkzeugeinheit der Transportvorrichtung;

Fig. 12 -

eine perspektivische Hinteransicht der Greifwerkzeugeinheit der Fig. 11;

Fig. 13 -

eine Vorderansicht der Greifwerkzeugeinheit der Fig. 11;

Fig. 14 -

einen Schnitt durch die Greifwerkzeugeinheit gemäss der Linie XIV-XIV der Fig. 13;

Fig. 15 -

eine Seitenansicht der Greifwerkzeugeinheit gemäss Fig. 11;

Fig. 16 -

einen Schnitt durch die Greifwerkzeugeinheit gemäss der Linie XVI-XVI der Fig. 15;

Fig. 17 -

einen Schnitt durch die Greifwerkzeugeinheit gemäss der Linie XVII-XVII der Fig. 15;

Fig. 18 -

eine schematische Darstellung einer Steuerungsanordnung der Bearbeitungseinrichtung bzw. deren Transportvorrichtung;

Fig. 19 -

einen schematischen Bewegungspfad der Greifwerkzeuge der Transportvorrichtung im Normalbetrieb; und

Fig. 20 -

einen schematischen Bewegungspfad der Greifwerkzeuge bei einer Prozessstörung.

The invention is described in more detail below with reference to an embodiment shown in the drawings. Show it:

Figures 1-6 -

schematic views and sectional views of the processing device in different phases of a workflow;

Fig. 7 -

an overall perspective view of the transport device of the processing device according to the Figures 1-6 ;

Fig. 8 -

a front view of the transport device;

Fig. 9 -

a side view of the transport device;

Fig. 10 -

a section through the transport device according to line XX of the Fig. 9 ;

Fig. 11 -

a perspective view of a gripping tool unit of the transport device;

Fig. 12 -

a rear perspective view of the gripping tool unit of the Fig. 11 ;

Fig. 13 -

a front view of the gripping tool unit of the Fig. 11 ;

Fig. 14 -

a section through the gripping tool unit along the line XIV-XIV the Fig. 13 ;

Fig. 15 -

a side view of the gripping tool unit according to Fig. 11 ;

Fig. 16 -

a section through the gripping tool unit along the line XVI-XVI of Fig. 15 ;

Fig. 17 -

a section through the gripping tool unit along the line XVII-XVII the Fig. 15 ;

Fig. 18 -

a schematic representation of a control arrangement of the processing device or its transport device;

Fig. 19 -

a schematic movement path of the gripping tools of the transport device in normal operation; and

Fig. 20 -

a schematic path of movement of the gripping tools in the event of a process failure.

The following definition applies to the description below: If reference numerals are given in a figure for the sake of clarity in the drawing, but are not mentioned in the immediately associated description part, reference is made to their explanation in the preceding or following description parts. Conversely, in order to avoid graphic overload, reference numbers that are less relevant for immediate understanding are not shown in all figures. For this purpose, reference is made to the other figures.

The schematic overview of the Figures 1-6 show the parts of the processing device according to the invention relevant for understanding the present invention, here using the example of a forming device. While Fig. 1 a front view according to line II in Fig. 2 is shows Fig. 2 a sectional view along the line II-II in Fig. 1 . They are accordingly Figures 3 and 5 Front views and the Figures 4 and 6 associated sectional views.

The forming device, designated as a whole by M, in the exemplary embodiment shown comprises five steps 110, 120, 130, 140, 150 arranged next to one another, of which a first step 110 is a loading step and the remaining steps 120, 130, 140 and 150 are forming steps. The forming stages 120, 130, 140 and 150 comprise four forming dies 121, 131, 141 and 151 formed in a common die holder 101, four forming tools in the form of pressing dies 122, 132, 142 and 152 and four ejection elements 123, 133, 143 and 153, with which workpieces W formed in the forming dies by means of the press rams can be ejected from the forming dies. The loading stage 110 comprises a shearing device 112 for shearing off a workpiece W from a bar material (not shown, by means of a bar material feed device, also not shown) and an ejection element 113 with which a workpiece W can be ejected from the shearing device 112. A transport device, designated overall by T, serves to transfer the workpieces from one stage to the next subsequent stage of the forming device M. In the Figures 1-6 of the transport device T, only gripping tools each with a pair of tong arms 32a and 32b are shown.

When the forming device is in operation, the pincer-like gripping tools of the transport device T formed by the pincer arm pairs 32a and 32b each take in a starting position one provided in the loading stage 110 or from the forming dies 121, 131, 141 and 151 of the forming stages 120, 130, 140 and 150 ejected workpiece W on ( Figures 1 and 2 ) and then transport these workpieces W to the next subsequent stage of the forming device M at the same time, the finished formed workpiece W picked up from the last forming step 150 being released so that it can be removed from the forming device. The Figures 3 and 4 illustrate this. In the forming stages 120, 130, 140 and 150, the workpieces W are introduced and shaped into the forming dies 121, 131, 141 and 151 by means of the press punches 122, 132, 142 and 152. The transport device T then moves the (empty) gripping tools into the Figures 1 and 2 shown starting position back. There, the gripping tools each take up a new workpiece W provided in the loading stage 110 or ejected from the forming dies 121, 131, 141 and 151 of the forming stages 120, 130, 140 and 150 and in turn transport these workpieces to the next subsequent stage of the forming device, so like this in the Figures 3 and 4 is shown. The whole process takes place in a transport cycle in the machine cycle of the forming device M.

It is clear from the above brief description of the relocating process that each gripping tool transports a different workpiece in each relocating cycle, and each pair of adjacent stages of the machining device is operated by a different gripping tool. Within the scope of the present invention, the transfer of workpieces from stage to stage of the processing device by means of several gripping tools is to be understood in this sense.

To this extent, the machining or forming device M shown corresponds in structure and mode of operation to conventional machining or forming devices of this type, so that the person skilled in the art needs no further explanation in this regard.

The following is based on the Figures 7-17 the transport device of the processing or forming device M explained in detail. The transport device, denoted as a whole by T, comprises a stationary frame 10, a plate-like gripping tool carrier 20 which is movably arranged in or on the frame 10 and in this example carries five gripping tool units 30, and a gripping tool carrier drive. The gripping tool units 30 are all at the same distance from a common reference plane E ( Fig. 7 ) arranged. A front surface of the plate-like gripping tool carrier 20 facing the gripping tool units is aligned parallel to the reference plane E. The gripping tool carrier drive comprises two gripping tool carrier drive motors 55 and 56, which are each designed as servomotors with rotary encoders and gears and are fixedly mounted on the frame 10. Furthermore, the gripping tool carrier drive comprises two crank gear arrangements, each having a crank 51 or 52 and a drive rod (connecting rod) 53 or 54. The cranks 51 and 52 are each fixedly mounted on a rotatable part of the gears of the gripping tool carrier drive motors 55 and 56 and can be driven in rotation by the latter. In practical use, the frame 10 is detachably or pivotably mounted on the machine body of the shaping device M (not shown), so that access to the shaping dies and to the shaping tools can be released in a simple manner.

Two parallel guide rods 11 and 12 are arranged in the frame 10 ( Figures 7-10 ) whose axes define the reference plane E ( Fig. 7 ). On or on these guide rods 11 and 12, two links 13 and 14 are linearly movable in the longitudinal direction of the guide rods. The two links 13 and 14 are also pivotally pivoted about one of the two guide rods 11 and 12, respectively. At their ends facing away from the guide rods, the links 13 and 14 are connected by means of pairs of pivots 15 and 16 ( Figures 9 and 10th ) pivotally attached to the gripping tool carrier 20. The distance between the two pairs of pivots 15 and 16 is equal to the distance between the two guide rods 11 and 12. The distance between the pair of pivots 15 from the guide rod 11 is the same as the distance between the pair of pivots 16 from the guide rod 12. The two parallel guide rods 11 and 12 and the two links 13 and 14 thus form together with the gripping tool carrier 20 a parallelogram guide arrangement for the latter, the gripping tool carrier 20 being deflectable in both directions (up and down in the figures) transversely to the longitudinal direction of the guide rods 11 and 12. In Fig. 7 this is symbolized by the double arrow 25. At the same time, the gripping tool carrier 20 can be moved back and forth along the guide rods 11 and 12 in the longitudinal direction of the guide rods 11 and 12, which is shown in FIG Fig. 7 is indicated by the double arrow 26. The gripping tool carrier 20 is thus guided on the one hand in a linearly movable manner parallel to the reference plane E and on the other hand is mounted so as to be deflectable essentially parallel to the reference plane E transversely to its linear mobility.

The drive rods (connecting rods) 53 and 54 are each pivoted at one end to the crank 51 and 52 and at the other end to the gripping tool carrier 20. By correspondingly turning the two cranks 51 and 52 by means of the two gripping tool carrier drive motors 55 and 56, the gripping tool carrier 20 can be moved in any direction (within predetermined limits) in the direction of the double arrow 26 and / or the double arrow 25.

An advantage of the parallelogram guidance is to be seen in the fact that the gripping tool carrier 20 executes only a small movement perpendicular to its deflection movement, that is to say perpendicular to the reference plane E, during its transverse deflection (pivoting movement around the guide rods).

In Fig. 19 a typical movement path of the gripping tool carrier 20 and thus of the gripping tool units 30 attached to it is shown schematically. The self-contained, cyclically traversed movement path 21 comprises four movement path sections 21a-21d. The two linear movement path sections 21a and 21c correspond to the linearly guided sliding movement of the gripping tool carrier 20 along the guide rods during the forward and backward movement between the stages of the shaping device, the two movement path sections 21b and 21d result from the deflection of the gripping tool carrier 20 by means of the parallelogram guide arrangement. Points 22 and 23 mark the in Fig. 1 shown starting position or in Fig. 3 illustrated position of the gripping tool carrier 20 shifted by one step the Fig. 19 shows, the outward movement of the gripping tool carrier 20 takes place along a first linear movement path (movement path section 21a), while the return movement of the gripping tool carrier 20 takes place along a linear movement path (movement path section 21c) parallel to the first linear movement path. The distance between the two linear movement paths resulting from the deflection of the gripping tool carrier 20 is selected such that the gripping tool units 30 or their gripping tools arranged on the gripping tool carrier 20 are at the level of the second linear movement path outside the engagement area of the forming tools 122, 132, 142, 152 located in the forming stages 120, 130, 140, 150, like this Fig. 5 can be seen. A waiting position is marked with 27 and will be returned to below.

The gripping tool units 30 arranged next to one another on the gripping tool carrier 20 are all of the same design. Your structure is based on the Figures 11-17 forth.

Each gripping tool unit 30 comprises a pliers body 31, a pair of movable pliers arms 32a and 32b forming a gripping pliers, and a gripping tool drive in the form of an (electric) servo motor 33 with a rotary encoder and gearbox, the servo motor only in FIGS Figures 9 and 14 is shown. The pliers body 31 and the servo motor 33 including the transmission are each mounted on the gripping tool carrier 20. The two gun arms 32a and 32b are movably arranged on the gun body 31.

Two pliers slides 35a and 35b are slidably mounted in the pliers body 31 on three guide rods 34a, 34b and 34c. The pliers slides 35a and 35b are each kinematically connected via a drive rod 36a or 36b to a rack 37a or 37b, so that a movement of the racks causes the pliers slides to move along and vice versa. The two racks 37a and 37b are in engagement with a drive pinion 38 on diagonally opposite sides of the same, which can be driven in rotation by the servo motor 33 (via its gearbox), so that when the drive pinion 38 rotates, the two racks 37a and 37b move in opposite directions and thus the two tong arms 32a and 32b are moved towards or away from each other. The opening and closing movement the gripping pliers formed by the pliers arms 32a and 32b are thus carried out by the servo motor 33 or the drive pinion 38 driven thereby.

The gripping tool drive can alternatively also be designed as a servo-controlled (having servo valves) hydraulic drive. It is essential that the movement of the gripping tongs can be done very quickly and, above all, position-controlled and the clamping force of the two tongs arms can be precisely adjusted or regulated and reported on the other hand, as is the case with the gripping tool drive described above with an electric servo motor is.

On the free ends of the two pliers arms 32a and 32b, pliers shoes 39a and 39b are arranged, which serve for gripping the workpieces and are interchangeably fastened, so that the gripping pliers can be easily adapted to the shape of the workpieces to be gripped ( Fig. 11 ). The pliers shoes do not have to be designed and / or arranged identically on all gripping pliers. As shown, two pliers shoes are preferably arranged on each gun arm, which overall form a particularly expedient four-point holder for the workpieces to be gripped. Such a four-point holder enables the workpieces to be securely held on the one hand and on the other hand reduces the risk of the workpieces tipping, particularly when inserted into closed gripping tongs.

The gun arms 32a and 32b are detachably connected to the gun carriages 35a and 35b via a pair of end-toothed plates 40a and 40b, respectively ( Figures 15 and 17th ). In this way, the pliers arms 32a and 32b can easily be adjusted laterally or in height relative to the pliers slides 35a and 35b, for example in order to adapt the gripping pliers to the respective workpiece.

It goes without saying that instead of gripping tongs, differently designed gripping tools can also be used in the transport device according to the invention. For example, the gripping tools could also be designed as a vacuum gripper. When used in a forming device, however, gripping tools in the form of gripping tongs are common and proven.

As in Fig. 18 is shown schematically, the transport device T also includes a carrier control 60 for the gripping tool carrier drive motors 55 and 56 and a gripping tool control 70 for controlling the gripping tool drive motors 33 of the individual gripping tool units 30. The gripping tool control 70 is designed to control the opening and closing movements and the clamping force of the individual Gripping tools, here gripping tongs 32a and 32b, to be controlled individually. The carrier controller 60 calculates the rotational positions of the two cranks 51 and 52 required in each case for moving the movement path 21 of the gripping tool carrier 20 and controls the servomotors 55 and 56 accordingly. The carrier control 60 also cooperates with a sensor device 65, which is designed to detect a process malfunction in the loading stage 110, for example due to a workpiece W ′ which cannot be machined or is missing, and to signal the carrier control 60.

The in the Figures 2 , 4th and 6 only symbolically indicated sensor device 65 is assigned to the already mentioned, not shown bar material feed device and can be, for example, a light barrier arrangement. Such sensor devices on bar feeders are known per se and for example in the EP 1 848 556 B1 described. The sensor device 65 is able to detect rod beginnings and rod ends. If the sensor device 65 detects a bar start or a bar end, it signals this to the carrier controller 60, so that the carrier controller knows that the next following bar section is faulty and must be eliminated or must not be introduced into the forming process. The carrier controller 60 then reacts to this process fault in the manner explained in more detail below.

The carrier control 60 and the gripping tool control 70 work together with a higher-level control 80, which, among other things, also establishes the connection to the processing device and specifies at which position of the movement path the gripping tool carrier or its gripping tools should be located. By means of the higher-level control 80, an operator can also make settings, for example relating to the movement of the gripping tool carrier or opening and closing movements of the gripping tongs enter or change. Of course, the functions of the carrier control 60, the gripping tool control 70 and the higher-level control 80 can also be implemented in another configuration, for example combined in a single control.

As already mentioned at the beginning, the raw material is usually fed in the form of a rod, from which pieces of suitable length are then sheared off, in forming devices, especially hot-forming devices. The bar ends and bar beginnings must not get into the forming process and must be eliminated. These separated sections are missing in the forming process and generate empty forming stages in the forming device, which should be avoided for the reasons explained at the beginning.

Thanks to the independent drive of the gripping tool carrier 20 or the gripping tools 32a, 32b, which is decoupled from the drive train of the forming device, the transport device according to the invention described above creates the possibility of avoiding empty forming steps in a forming device.

If, for example, a process malfunction is identified by means of the sensor device 65 mentioned, which is caused by a missing or not suitable workpiece W 'to be further processed ( Figures 5 and 6 ), the sensor device 65 sends a corresponding control command to the carrier control 60 for the gripping tool carrier drive. The carrier control 60 then causes the gripping tool carrier 20 with the gripping tool units 30 not to follow the usual movement path 21 ( Fig. 19 ) follows, but that the gripping tool carrier 20 with the workpieces W located in the gripping tool units 30 is moved into a waiting position 27 ( Fig. 20 ). The waiting position is, for example, on the upper movement path section 21c of the gripping tool carrier 20, the pliers arms 32a and 32b of the gripping tool units 30 being located above and between the tools 112, 122, 132, 142 and 152, so that they are out of reach of the same. This situation is in the Figures 5 and 6 shown. The forming tools then carry out an idle stroke, but this is not a negative one This has consequences, since all the forming stages are empty. The tool cooling is preferably interrupted in this phase, so that the tools and the workpieces in the waiting position are not cooled. The defective workpiece W 'is eliminated (in a manner known per se).

As soon as the sensor device 65 reports that a workpiece W suitable for the forming process will arrive again in the loading stage 110, the carrier controller 60 causes the gripping tool carrier 20 to return to its original movement path, the workpieces being transferred to the respective forming stages and the gripping tool carrier 20 then along its normal path of movement 21 into its in the Figures 1 and 2 shown starting position 22 goes to pick up workpieces W there and then transport them to the next subsequent forming stage.

In Fig. 20 the movement sequence of the gripping tool carrier 20 just described is graphically illustrated in the event of a process fault. The movement of the gripping tool carrier 20 into the waiting position 27 takes place along a movement path section 24a and the movement of the gripping tool carrier 20 from the waiting position 27 to the position 23 takes place along a movement path section 24b. The entire movement path from position 22 via waiting position 27 to position 23 is designated by 24. The movement path sections 24a and 24b do not necessarily have to be the one in FIG Fig. 20 have shown history. The gripping tool carrier 20 can also be moved, for example, along alternative movement path sections 24a 'and 24b', which correspond to the movement path sections 21d and 21c or 21c and 21b of the normal movement path 21.

By uncoupling the transport device from the drive train of the forming device, the time and distance for transporting, lifting and gripping can be set and varied independently of the stroke of the forming tools. Ventilation here means the vertical deflection of the gripping tool carrier 20, the ventilation stroke corresponding to the vertical distance between the two movement path sections 21a and 21c. The from the hub of the Forming tools decoupled setting of lifting and gripping movement allows individual adjustment to the respective workpieces, which reduces machine wear. In addition, it is also possible to react to the situation and the gripping tool carrier 20 in the case of accidents in the tool room, for example if a shaped part has not been completely pushed out of the forming die or a broken press stamp has got stuck in the forming die or a shaped part has been lost from a gripping tool to move with its gripping tool units 30 into a safe position, for example the aforementioned waiting position 27, and to stop the forming device until the fault has been rectified. This can prevent, for example, tearing off gripping tools or causing other consequential damage to the transport device.

As already mentioned, the gripping tool units 30 can be individually controlled by means of the gripping tool control 70. As a result, the time for opening and closing can be set individually for each gripping tool unit. The opening stroke of the tong arms 32a and 32b and the duration of the movement can also be matched to the respective workpiece. The same applies to the ventilation movement. This can also be optimized for each workpiece in terms of stroke and duration with the aim of keeping acceleration and thus load on the construction of the device low. In contrast to this, known transport devices with control cams must always be designed for the maximum possible stroke, with the result that the components are exposed to maximum load and thus maximum wear on each workpiece or formed part.

In order to compensate for shape errors in the blank section or to achieve eccentric volume distribution, for example in the production of cams, it is necessary to adjust the first or another gripping pliers off-center. In known transport devices, eccentric adjusting elements are used for this purpose, or the pliers shoes are adjusted by trial and error so that the center of the workpiece is shifted from the center by the desired amount. With the transport device according to the invention, the gripping tool carrier 20 can be made by simply entering the desired values on the superordinate control 80 can be moved by the desired dimension from the center (zero position) by means of the gripping tool carrier drive motors 55 and 56. The gripping pliers in question are then aligned with a central setting element and the gripping tool carrier is then moved back to its zero position. In this way, one or several gripping tongs can be set off-center. The remaining gripping tongs are set when the gripping tool carrier 20 is again centered (in the zero position).

The clamping or holding force of each gripping tool unit 30 is controlled by means of the gripping tool control 70 via the torque of the associated servo motor 33 and can thus be easily adapted to the workpiece to be held and, if necessary, also varied over the movement cycle of the gripping tool carrier. The clamping force can e.g. when inserting the workpieces into the gripper are set smaller than for transport. The load on the mechanical components is only as great as necessary.

Servomotors usually have a rotary encoder for reporting the current rotary position to their controller. With the rotary encoder, the gripping tool control 70 can easily determine whether a gripping tool is filled or empty, for example if a workpiece has been lost from a gripping tool, by comparing the actual to the target rotational position, so that the forming device can be stopped if necessary. By appropriately designing the gripping tool control 70, process malfunctions, which are caused, for example, by crooked workpieces in the gripping tools or tearing of the gripping tools, can also be detected in this way. In this case, this signals the gripping tool control 70 to the carrier control 60 in a suitable manner, and the carrier control 60 then causes the gripping tool carrier 20 with the gripping tool units 30 to be moved into a safe position, for example the aforementioned waiting position 27, and stopped there until the process malfunction is fixed. The danger of tearing open a gripping tool arises, for example, if a workpiece is incompletely pushed out of the die or the ram breaks and gets stuck in the workpiece. When trying to transport the workpiece, the gripping tool would be torn open. However, the gripping tool control 70 recognizes this early and causes the gripping tool carrier to move back via the carrier control 60, so that the tearing of the gripping tool concerned is prevented. The gripping tool carrier 20 with the gripping tool units 30 is then moved into a safe position, for example the waiting position 27 mentioned, and stopped there until the process fault has been eliminated. The forming device is of course stopped during this time. In this way, a process fault can be reacted to immediately before major damage occurs. The cooperation of the gripping tool control 70 with the carrier control 60 is shown in FIG Fig. 18 symbolized by arrow 71.

The gripping tools or gripping tongs of the transport device shown have parallel tong arms 32a and 32b which are moved linearly towards or away from one another. Such gripping pliers have the advantage over gripping pliers with pivoting pliers arms that the pliers shoes are evenly immersed in the gripping diameter. If the pliers shoes grip the workpiece at the same angle on both sides, they are pressed on by the same amount when the workpiece is inserted. This reduces the risk of a workpiece being slanted into the gripper.

Claims (20)

1. Transport apparatus for transferring workpieces in a processing device (M) comprising at least two stations (110, 120, 130, 140, 150), especially in a forming device, having at least two gripping tools (32a, 32b), each for gripping one workpiece (W), which gripping tools (32a, 32b) are arranged on a gripping tool support (20) which is movable back and forth between the stations (110, 120, 130, 140, 150) of the processing device (M), characterised in that the gripping tool support (20) is on the one hand movably mounted so as to be linearly guided and on the other hand mounted so as to be displaceable transversely with respect to its linearly guided movability, and, for the linearly guided movement and transverse displacement of the gripping tool support (20), the transport apparatus comprises a gripping tool support drive (51-56) having at least one gripping tool support drive motor (55, 56).
2. Transport apparatus according to claim 1, characterised in that it has a parallelogram guide arrangement (11-16) for the displacement of the gripping tool support (20) transversely with respect to its linearly guided movability.
3. Transport apparatus according to claim 1 or 2, characterised in that the gripping tool support drive (51-56) comprises two crank gear arrangements (51-54) each having an associated gripping tool support drive motor (55, 56), wherein each crank gear arrangement (51-54) has a crank (51, 52), which is drivable in rotation by the associated gripping tool support drive motor (55, 56), and a drive rod (53, 54) which is articulatedly connected on the one hand to the crank (51, 52) and on the other hand to the gripping tool support (20).
4. Transport apparatus according to any one of claims 1-3, characterised in that the gripping tool support drive motor (55, 56) or the gripping tool support drive motors (55, 56) are servo motors having rotary encoders.
5. Transport apparatus according to any one of claims 1-4, characterised in that the gripping tool support (20) with the gripping tools (32a, 32b) is movable by means of the gripping tool support drive (51-56) in a forward movement along a first linear path of movement (21a) and in a return movement along a second linear path of movement (21c) parallel to the first linear path of movement.
6. Transport apparatus according to any one of claims 1-5, characterised in that the gripping tool support (20) is slidably mounted on at least two guide rods (11, 12).
7. Transport apparatus according to claims 2 and 6, characterised in that the parallelogram guide arrangement comprises at least two link rods (13, 14) which on the one hand are each mounted on a respective one of the guide rods (11, 12) so as to be pivotable about that guide rod and slidable in the longitudinal direction thereof and which on the other hand are articulatedly connected to the gripping tool support (20).
8. Transport apparatus according to any one of claims 1-7, characterised in that it has a support controller (60) for the gripping tool support drive motors (55, 56) which is configured to control the movement of the gripping tool support (20).
9. Transport apparatus according to claim 8, characterised in that the support controller (60) is configured, as a result of a control command supplied thereto, to move the gripping tool support (20) with the gripping tools (32a, 32b) into a waiting position (27) and to suspend the transport of the workpieces.
10. Transport apparatus according to any one of claims 1-9, characterised in that the gripping tools (32a, 32b) are each assigned a gripping tool drive (33), which is preferably arranged on the gripping tool support (20), for individual operation of the gripping tools (32a, 32b) for gripping or releasing a workpiece (W).
11. Transport apparatus according to any one of claims 1-10, characterised in that the gripping tools are configured as gripping tongs, and the gripping tongs each have two tong arms (32a, 32b) which are movable linearly towards one another and away from one another.
12. Transport apparatus according to claim 11, characterised in that the tong arms (32a, 32b) are each arranged on a respective tong carriage (35a, 35b) which is slidably mounted in a tong body (31); the tong carriages (35a, 35b) are each kinematically connected to a respective toothed rod (37a, 37b); and the toothed rods (37a, 37b) are in engagement with a motor-drivable drive pinion (38), the tong carriages (35a, 35b) and accordingly the tong arms (32a, 32b) being movable in opposite directions by means of the drive pinion (38).
13. Transport apparatus according to claim 12, characterised in that the tong arms (32a, 32b) are arranged on the tong carriages (35a, 35b) so as to be adjustable relative thereto.
14. Transport apparatus according to any one of claims 10-13, characterised in that the gripping tool drives (33) are assigned a gripping tool controller (70) which is configured to control the opening and closing movements and the clamping force of the individual gripping tools (32a, 32b) individually.
15. Transport apparatus according to claims 9 and 14, characterised in that the gripping tool controller (70) is configured to recognise a process disturbance caused by an empty gripping tool or by a workpiece incorrectly inserted into the gripping tool and to signal that disturbance to the support controller (60).
16. Processing device, especially a forming device, having at least two successive stations (110, 120, 130, 140, 150) and a transport apparatus (T) according to any one of claims 1-15 for transferring workpieces (W) between the stations of the processing device.
17. Processing device according to claim 16, characterised in that it has a support controller (60) which is configured to move the gripping tool support (20) with the gripping tools (32a, 32b) into a waiting position (27) in which the gripping tools (32a, 32b) are located outside the operating range of processing tools (112, 122, 132, 142, 152) of the stations (110, 120, 130, 140, 150) of the processing device (M) and to suspend the transport of the workpieces (W).
18. Processing device according to claim 17, characterised in that the first station (110) of the successive stations (110, 120, 130, 140, 150) of the processing device is a loading station, and the support controller (60) is configured to move the gripping tool support (20) with the gripping tools (32a, 32b) into the waiting position in the event of a process disturbance caused by a missing or unprocessable workpiece (W') in the loading station (110).
19. Processing device according to claim 18, characterised in that it has a sensor device (65), which co-operates with the support controller (60) for the gripping tool support drive motors (55, 56), for recognising the process disturbance and for signalling that disturbance to the support controller (60).
20. Processing device according to claim 18 or 19, characterised in that the support controller (60) is configured to move the gripping tool support (20) with the gripping tools (32a, 32b) out of the waiting position once the process disturbance has been eliminated and to resume the transport of the workpieces (W).

Images