EP3448597A1

EP3448597A1 - Transport method for transferring workpieces

Info

Publication number: EP3448597A1
Application number: EP17719252.3A
Authority: EP
Inventors: Markus Moser; Stephan LEIBUNDGUT; Andreas MARITZ; Andreas Matt
Original assignee: Hatebur Umformmaschinen AG
Current assignee: Hatebur Umformmaschinen AG
Priority date: 2016-04-28
Filing date: 2017-04-25
Publication date: 2019-03-06
Anticipated expiration: 2037-04-25
Also published as: ES2808998T3; EP3448597B1; WO2017186675A1; US10537932B2; CH712403A1; CN109070188A; CN109070188B; JP7266408B2; KR20190002484A; US20190118241A1; EA201892458A1; KR102353811B1; JP2023055700A; JP2019520983A; TW201739536A

Abstract

The invention relates to a transport method for transferring workpieces between multiple consecutive stages of a processing unit, in particular a shaping unit, wherein each workpiece is transported in a transport cycle from one stage to the respective following stage of the processing unit, simultaneously by means of multiple mutually moveable gripping tools. In the event of a process disturbance, the transport cycle is interrupted and the gripping tools with the workpieces are moved into a waiting position (27), in which the workpieces are outside of the effective region of processing tools of the stages of the processing unit. After the process disturbance has ended, the transport cycle of the workpieces is recommenced. Resultant damages of the process disturbance can be prevented via the movement of the gripping tools into a secure waiting position outside of the effective region of the processing tools of the stages.

Description

Transport method for transferring workpieces

The invention relates to a transport method for transferring workpieces between a plurality of successive stages of a processing device, in particular a forming device, according to the preamble of patent claim 1 and a transport device for carrying out the transport method according to the preamble of patent claim 7.

For massive forming and also for other forming processes or

In general, machining operations frequently pass through several stages of a processing device, with the workpieces being transported from stage to stage. In a forming apparatus, the stages are typically a loading stage and various forming stages. To transport the workpieces from stage to stage are usually with pincers

Gripping tools equipped, working in the machine cycle of the processing device transport devices, the gripping tools simultaneously detect the workpieces, take out of a stage and each next stage, where they release it. In the known processing devices, in particular forming devices, the transport movements and the operation of the gripping tools with the drive sträng the processing device coupled - see, for example. the CH 595 155 A.

EP 2 233 221 A2 discloses a punching device for a follow-on punching press, in which punched parts are transported by means of gripping tools on a rotating arm star from one processing station to the next. The rotary arm star is thereby alternately clockwise and in the drive of a drive motor

Turned counterclockwise. A transport device for converting workpieces in one

Forming device is described in EP 1 048 372 Bl. In this known transport device are designed as gripping tongs gripping tools with each with its own, decoupled from the drive train of the forming device

Gripping tool drive arranged on a longitudinally and transversely to this movable common pliers carrier, by means of which all grippers are transported together in each case between two adjacent stages of a forming device back and forth. The gripping tongs comprise two pivot arms, which are driven by a servo motor via kinematic coupling members towards and away from each other pivotally. The EP 1 048 372 Bl essentially deals with the design of the gripping tongs and their drives, the drive of the forceps carrier for carrying out the Umsetzbewegungen the gripping tongs is not described specifically

In forming equipment, especially hot forming equipment, the raw material is usually fed in bar form, from which then pieces of the required length are cut off. The rod ends and rod beginnings must not enter into the forming process and must be eliminated. These excreted sections are missing in the forming process and produce in the

Forming device individual empty forming steps. Because of the missing 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 then such parts can not be used and must be sorted out manually from the finished parts or discharged by means of suitable switches. Because the

mechanical ejection is not so accurate, under certain circumstances also good formed parts are discharged. In addition, an empty forming stage by

Cooling water cooled more strongly, which has a negative impact on the wear of

Forming tools affects. This problem is e.g. in EP 1 848 556 Bl explained in detail.

Another problem of conventional transport devices or the transport process carried out therewith is that in case of process disturbances, caused for example by empty gripping tools or by incorrectly inserted into the gripping tools workpieces or damaged parts such as torn gripping tools or broken punches, etc., not respond immediately can be and thus workpieces are not converted as desired or often Significant consequential damage to the transport device or on the processing device can occur.

Against this background, the invention is based on the object

Transport method of the type mentioned above and a corresponding

Transport device to be improved so that it can be easily and quickly responded to process disturbances, so that consequential damage can be avoided. In particular, voids should be avoided in the stages of the processing device.

This object is achieved by the inventive transport method and the inventive transport device, as described in the independent

Or claim 1 are defined in the independent claim 7. Particularly advantageous developments and refinements of the invention will become apparent from the respective dependent claims.

In terms of the method, the essence of the invention is as follows: In a transport method for converting workpieces between several successive stages of a processing device, in particular a forming device, the workpieces are each simultaneously by means of several jointly movable gripping tools in a transport cycle from one stage to the next successive stage Processing device transported. In the presence of a process failure, the transport cycle is interrupted and the gripping tools with the workpieces are moved to a waiting position, in which the workpieces are outside the range of action of processing tools of the stages of the processing device. After elimination of the process fault, the transport cycle of the workpieces is resumed.

The movement of the gripper tools into a safe waiting position outside the effective range of the processing tools of the stages can prevent consequential damage to the process disturbance. The method is particularly advantageous if the process disturbance is due to a missing or non-workable workpiece in a loading stage of the

Machining device is caused because it can be avoided empty processing stages and the associated disadvantages.

The method is also advantageous if the process disturbance is caused by a missing or incorrectly inserted into a gripping tool workpiece, as thus also empty machining stages or due to the incorrectly inserted workpiece caused further disturbances can be avoided.

The method is also advantageous if the process disturbance is caused by a damaged part of a gripping tool or a damaged part of the processing device, since in this way further consequential damage can be avoided.

Advantageously, the absence or presence of a workpiece that is not suitable for processing is detected by means of a sensor device, wherein the

Moving the gripping tools to the waiting position at the behest of the

Sensor device takes place. This allows in the case of due to the absence or presence of a non-work suitable workpiece

Process fault an automatic movement of the gripping tools to the waiting position.

Advantageously, the absence or presence of an incorrectly inserted into a gripping tool workpiece by means of a gripping tool control of a

Gripping tool drive detected, wherein the moving of the gripping tools in the

Waiting position is at the initiative of the gripper tool control. In the case of a process malfunction caused by the absence or presence of a workpiece incorrectly inserted into a gripping tool, this allows an automatic movement of the gripping tools into the waiting position.

With regard to the transport device for carrying out the method, the essence of the invention consists in the following: A transport device has a movably mounted gripping tool carrier, to which a plurality of gripping tools for Gripping ever a workpiece are arranged, and a motor

Gripping tool carrier drive for reciprocating movement of the

Gripping tool carrier with the gripping tools between the steps of

Processing device on. The gripper tool carrier drive is designed to move the gripper tool carrier with the gripping tools in a waiting position. The transport device furthermore has a carrier control for the gripper-tool carrier drive, which is designed to control the movement of the gripper-tool carrier and to grasp the gripper-tool carrier with the gripper tools by means of the control command supplied thereto

Gripping tool carrier drive to move to the waiting position and to interrupt the transport of the workpieces.

By means of the transport device according to the invention, the workpiece transport can easily be interrupted when a process disturbance occurs and the gripper tool carrier with the gripping tools can simply be moved into a secure position so that consequential damage can be avoided.

Conveniently, the gripping tool carrier is on the one hand linearly movably mounted and on the other hand mounted deflectable transversely to its linearly guided mobility by means of a Parallelogrammführungsanordnung. Furthermore, the

Gripping tool carrier with advantage by means of a two crank gear assemblies, each with an associated gripping tool carrier drive motor comprehensive

Greifwerkzeugträgerantriebs movable, each crank gear assembly comprises a rotatably driven by the associated gripper tool carrier drive motor crank and a drive rod, which with the crank on the one hand and the

Gripping tool carrier on the other hand is hingedly connected.

By own Grip tool carrier drive, the transport device from the drive sträng the processing device is decoupled. Due to the decoupling and the deflectability of the gripping tool carrier transversely to its linear reciprocating motion of the gripper tool carrier can be moved quickly in case of failure in a safe position. The kinematic coupling of the gripper tool carrier with the gripper tool carrier drive motors via two crank gear assemblies allows easy control of the motion sequences solely by appropriate control of the gripper tool drive drive smotors.

Advantageously, the gripping tool carrier with the gripping tools by means of the gripper tool carrier drive in a forward movement along a first linear trajectory and in a return movement along one to the first linear

Movement path parallel second linear motion path movable. Due to the distance between the two linear trajectories, the

Gripping tools are easily moved out of the sphere of action of machining tools in the steps of the processing device out.

Most advantageously, the transport device has a

Sensor device for detecting a by a missing or not to

Processing suitable workpiece conditional process disturbance and to signal the same to the carrier control on. Thereby, the carrier control can be automatically caused to move the gripping tools in the waiting position.

Advantageously, each of the gripping tools arranged on the gripper tool carrier gripper drive for the individual actuation of the

Assigned gripping tools and a gripping tool control, which is designed to control the opening and closing movements and preferably also the clamping force of the individual gripping tools individually and to recognize a by an empty gripping tool or incorrectly inserted into a gripping tool workpiece related process disturbance and the carrier control to signal. Thereby, the carrier control can be automatically caused to move the gripping tools in the waiting position.

In the following the invention will be described in more detail with reference to an embodiment shown in the drawings. Show it:

Figures 1-6 - schematic views and sectional views of

Processing device in different phases of a workflow; an overall perspective view of the transport device of the processing device according to Figures 1-6; a front view of the transport device; a side view of the transport device; a section through the transport device according to the line XX of FIG. 9; a perspective view of a gripping tool unit of the transport device; a rear perspective view of the gripping tool unit of FIG.

I i; a front view of the gripping tool unit of Fig. 11; a section through the gripper unit according to the line XIV-XIV of FIG. 13; a side view of the gripping tool unit according to FIG. 11; a section through the gripping tool unit according to the line

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

XVII-XVII of Fig. 15; a schematic representation of a control arrangement of the processing device or its transport device; Fig. 19 - a schematic path of movement of the gripping tools of

Transport device in normal operation; and

Fig. 20 - a schematic path of movement of the gripping tools in a

Process upset.

The following definition applies to the following description: If reference signs have been given in a figure for the purpose of clarity of drawing, but are not mentioned in the directly related part of the description, reference will be made to them

Explanation referenced in the preceding or following parts of description. Conversely, less relevant reference numerals are not included in all figures to avoid overcharging graphic for the immediate understanding. For this purpose, reference is made to the other figures. The schematic overview representations of Figures 1-6 show the for the

Understanding the present invention relevant parts of the inventive processing device, here the example of a forming device. While Fig. 1 is a front view taken along the line I-I in Fig. 2, Fig. 2 shows a

Sectional view according to the line II-II in Fig. 1. Accordingly, Figures 3 and 5 are front views and Figures 4 and 6 are corresponding sectional views.

In the exemplary embodiment illustrated, the shaping device designated M as a whole comprises five adjacently arranged steps 110, 120, 130, 140, 150, of which a first stage 110 is a loading stage and the remaining stages 120, 130, 140 and 150 are forming stages. 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 press dies 122, 132, 142 and 152 and four ejecting members 123, 133, 143 and 153, with those in the

Forming dies can be ejected from the forming dies by means of the workpieces W formed by the press dies. The loading stage 110 comprises a shearing device 112 for shearing a workpiece W from a bar material (not shown, supplied by means of a bar material supply device, also not shown) and an ejecting member 113, with which a workpiece W can be ejected from the shearing device 112. A transport device, generally designated T, serves to transfer the workpieces from one step to the next step of the forming device M. In FIGS. 1-6, only gripper tools, each with a pair of tong arms 32a and 32b, are shown by the transport device T.

During operation of the forming device, the tong-like gripping tools of the transporting device T formed by the pair of gun arms 32a and 32b respectively assume an initial position 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 simultaneously to each next stage of the forming device M, wherein the received from the last forming stage 150, finished formed workpiece W is released so that it can be removed from the forming device , Figures 3 and 4 illustrate this. In the forming stages 120, 130, 140 and 150, the workpieces W are introduced and shaped by means of the press dies 122, 132, 142 and 152 into the forming dies 121, 131, 141 and 151.

Subsequently, the transport device T moves the (empty) gripper tools back to the starting position shown in Figures 1 and 2. There take the

Gripping tools in each case a new, 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 and transport these workpieces in turn to the next stage of the forming device, as in Figures 3 and 4 is shown. The entire process takes place in a transport cycle in the machine cycle of the forming device M.

From the above brief description of the conversion process, it will be understood that each gripper tool has a different workpiece in each conversion cycle

transported and each pair of adjacent stages of the processing device is operated by another gripping tool. In the context of the present invention, the conversion of workpieces from stage to stage of the processing device by means of a plurality of gripper tools is to be understood in this sense. So far corresponds to the processing or forming device M shown in construction and operation conventional processing or

Forming devices of this type, so that the expert in this regard requires no further explanation.

In the following, with reference to the figures 7-17, the transport device of

Machining or forming device M explained in detail. The designated as a whole with T transport device comprises a stationary frame 10, a movably arranged in or on the frame 10, plate-like gripping tool carrier 20, which here in the example five gripping tool units 30 carries, and a

Gripping tool carrier drive. The gripping tool units 30 are all arranged at the same distance from a common reference plane E (FIG. 7). A the

Greifwerkzeugeinheiten facing front surface of the plate-like

Gripping tool carrier 20 is aligned parallel to the reference plane E. Of the

Gripping tool carrier drive comprises two gripper tool carrier drive motors 55 and 56, which are each designed as servomotors with rotary encoder and gear, and are fixedly mounted on the frame 10. Furthermore, the

Tool carrier drive two crank gear assemblies, each having a crank 51 and 52 and a drive rod (connecting rod) 53 and 54 respectively. The cranks 51 and 52 are each on a rotatable part of the transmission of

Gripping tool carrier drive motors 55 and 56 fixedly mounted and driven by this rotating. The frame 10 is in practical use on (not

shown) machine body of the forming device M solvable or

mounted pivoting away, so that the access to the forming dies and to the forming tools can be released easily.

In the frame 10, two parallel guide rods 11 and 12 are arranged (FIGS. 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 guided linearly movable in the longitudinal direction of the guide rods. The two links 13 and 14 are also hinged to each one of the two guide rods 11 and 12 pivotally. At their the guide rods from the end facing the handlebars 13 and 14 means

Pivot pairs 15 and 16 (Figures 9 and 10) pivotally mounted on the gripping tool carrier 20 attached. The distance between the two pairs of pivot pins 15 and 16 is equal to the distance between the two Rinnings rods 11 and 12. The distance of the pivot pin pair

15 of the Rinnings rod 11 is the same size as the distance of the pivot pin pair

16 of the gutter rod 12. The two parallel rifling rods 11 and 12 and the two links 13 and 14 thus form together with the gripping tool carrier 20 a Parallelogrammführungsanordnung for the latter, wherein the

Gripping tool carrier 20 in both directions (in the figures up and down) transversely to the longitudinal direction of the guide rods 11 and 12 is deflectable. In Fig. 7, this is symbolized by the double arrow 25. At the same time, the gripping tool carrier 20 is guided along the sliding rods 13 and 14 in the longitudinal direction of the guide rods 11 and 12 along this guided back and forth, which is indicated in Fig. 7 by the double arrow 26. The gripping tool carrier 20 is thus guided linearly movable on the one hand parallel to the reference plane E and on the other hand mounted so as to be deflectable transversely to its linear movement substantially parallel to the reference plane.

The drive rods (connecting rods) 53 and 54 are each rotatably connected at one end to the crank 51 and 52 and at the other end rotatably hinged to the gripping tool carrier 20. By corresponding rotation of the two cranks 51 and 52 by means of the two Greifwerkzeugträgerantriebsmotoren 55 and 56 of the gripping tool carrier 20 (within predetermined limits) can be moved arbitrarily in the direction of the double arrow 26 and / or the double arrow 25.

An advantage of the parallelogram is the fact that the

Gripping tool carrier 20 at its Querauslenkung (pivoting movement around the guide rods) only a small movement perpendicular to it

Deflection movement, ie perpendicular to the reference plane E executes.

In Fig. 19 is a typical movement path of the gripping tool carrier 20 and thus the attached thereto gripping tool units 30 is shown schematically. The self-contained, cyclically traversed motion path 21 comprises four

Motion path sections 21a-21d. The two linear movement path sections 21a and 21c correspond to the linear guided sliding movement of the

Gripping tool carrier 20 along the guide rods during the forward movement or the Return movement between the stages of the forming device, the two

Motion 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 starting position shown in FIG. 1 and the position of the gripping tool carrier 20 shifted by one step as shown in FIG. 3. As FIG. 19 shows, the gripping tool carrier 20 moves along a first linear path of movement (FIG. Movement path section 21a) while the

Return movement of the gripping tool carrier 20 along one of the first linear

Movement path parallel linear trajectory (motion path section 21c) takes place. The distance between the two linear trajectories resulting from the deflection of the gripper tool carrier 20 is selected such that the gripper tool units 30 or gripping tools arranged on the gripper tool carrier 20 are at the level of the second linear trajectory outside the engagement region of the forming tools 122, 132, 142, 152 located in the forming stages 120, 130, 140, 150, as can be seen from Fig. 5. With 27 a waiting position is marked, which will be returned further below.

The gripper tool units 30 arranged next to one another on the gripper tool carrier 20 are all of the same design. Their structure is apparent from Figures 11-17.

Each gripper unit 30 includes a tong body 31, a pair of movable tong arms 32a and 32b forming a gripper, and a gripper

Gripping tool drive in the form of an (electric) servomotor 33 with rotary encoder and gear, wherein the servo motor is shown only in Figures 9 and 14. The pliers body 31 and the servomotor 33 including gear are each on

Gripping tool carrier 20 mounted. The two tong arms 32a and 32b are movably arranged on the tong body 31.

In the tong body 31 are on three guide rods 34 a, 34 b and 34 c two

Pliers carriage 35a and 35b slidably mounted. The pliers slides 35a and 35b are each kinematically connected via a drive rod 36a and 36b, each with a rack 37a and 37b, so that a movement of the racks causes a co-movement of the pliers carriage and vice versa. The two racks 37a and 37b are engaged with a drive pinion 38 on diagonally opposite sides thereof, which is rotatably driven by the servo motor 33 (via the transmission), so that upon rotation of the drive pinion 38, the two racks 37a and 37b move in opposite directions and thus the two gun arms 32a and 32b be moved towards or away from each other. The opening and the closing movement of the gripping tongs formed by the forceps arms 32a and 32b is thus effected by the servomotor 33 or the drive pinion 38 driven by it.

The gripper tool drive may alternatively be designed as a servo-controlled (servo valves exhibiting) hydraulic drive. It is essential that the movement of the grippers on the one hand can be done very quickly and above all position-controlled and the clamping force of the two gun arms on the other hand precisely adjusted or regulated and confirmed, just as in the above-described gripper tool drive with electric servomotor the case is.

Pliers shoes 39a and 39b are arranged at the free ends of the two tong arms 32a and 32b, which serve for gripping the workpieces and are fastened interchangeably, so that the gripper tongs can be easily gripped against the shape of the workpieces

Workpieces can be adjusted (Fig. 11). The pliers shoes need not be the same design and / or arranged on all gripping pliers. Preferably, as shown, two pliers shoes are arranged on each pliers arm, which together form a particularly expedient four-point holder for the workpieces to be gripped. On the one hand, such a four-point holder enables a secure holding of the workpieces and, on the other hand, reduces the risk of tilting of the workpieces, in particular when they are inserted into closed gripping tongs.

The pliers arms 32a and 32b are detachably connected via a pair of end-toothed plates 40a and 40b to the pliers slides 35a and 35b, respectively (FIGS. 15 and 17). In this way, the forceps arms 32a and 32b can be easily adjusted laterally or in height relative to the forceps slides 35a and 35b, for example, to adapt the gripping tongs to the respective workpiece. It is understood that differently shaped gripping tools can be used in the inventive transport device instead of gripping tongs.

For example, the gripping tools could also be designed as a vacuum gripper. However, gripping tools in the form of grippers are common and proven in use in a forming device.

As shown schematically in FIG. 18, the transport device T also comprises a carrier control 60 for the gripper-tool carrier drive motors 55 and 56 and a gripper-tool controller 70 for the control of the gripper tool carrier drive motors 55 and 56

Gripping tool drive motors 33 of the individual gripping tool units 30. The gripper tool control 70 is adapted to the opening and

Closing movements and the clamping force of the individual gripper tools, here gripper tongs 32a and 32b to control individually. The carrier control 60 calculates the respective rotational positions of the two cranks 51 and 52 required for the movement path 21 of the gripping tool carrier 20 to be shut off and controls them

Servo motors 55 and 56 accordingly. The carrier controller 60 also cooperates with a sensor device 65 which is adapted to receive e.g. to detect a process failure caused by a non-workable or missing workpiece W in the loading stage 110 and to signal the carrier controller 60.

The sensor device 65, which is indicated only symbolically in FIGS. 2, 4 and 6, is associated with the rod material supply device (not shown), which is not shown, and may be e.g. be a light barrier arrangement. Such

Sensor devices on rod feed devices are known per se and described, for example, in EP 1 848 556 B1. The sensor device 65 is able to detect rod starts and rod ends. If the sensor device 65 detects a rod end or a rod end, it signals this to the carrier control 60, so that the carrier control knows that the next following rod portion is defective and has to be eliminated or may not be introduced into the forming process. The carrier controller 60 then responds to this process fault in the manner explained in more detail below. The carrier control 60 and the gripper control 70 cooperate 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 paths, the gripping tool carrier or its gripping tools are to be respectively. By means of the higher-level control 80, a

Operator also settings e.g. concerning the movement of the

Enter or change the gripper tool carrier or the opening and closing movements of the grippers. Of course, the functions of the

Carrier control 60, the gripper tool control 70 and the parent

Controller 80 is also realized in another configuration, e.g. be summarized in a single controller.

As already mentioned, is in forming equipment, especially

Hot forming, usually supplied to the raw material in bar form, which are then sheared off pieces of suitable length. The rod ends and rod beginnings must not enter into the forming process and must be eliminated. These excreted sections are missing in the

Forming process and generate in the forming empty forming stages, which should be avoided for the reasons explained above.

Thanks to the independent, decoupled from the drive train of the forming device drive the gripper tool carrier 20 and arranged on it

Gripping tools 32a, 32b provides the inventive transport device described above, the ability to empty forming stages in one

To avoid forming device.

If e.g. By means of said sensor device 65, a process malfunction is detected, which is due to a missing or not suitable for further processing, auszuscheidendes workpiece W (Figures 5 and 6), sends the

Sensor device 65 a corresponding control command to the carrier control 60 for the Greifwerkzeugträgerantrieb. The carrier control 60 then causes the gripper tool carrier 20 with the gripper tool units 30 not to follow the usual movement path 21 (FIG. 19), but rather that the gripper tool carrier 20 engages with the gripper tool carrier 20 in the gripping tool units 30 located workpieces W is moved to 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 with the gripper arms 32a and 32b of the gripping implement units 30 above and between the tools 112, 122, 132, 142 and 152 so as to be out of reach thereof. This situation is shown in FIGS. 5 and 6. As a result, the forming tools perform an idle stroke, but this has no negative consequences, since all the forming stages are empty. Preferably, the

Tool cooling interrupted in this phase, so that the tools and the waiting workpieces are not cooled. The faulty workpiece W is eliminated (in a conventional manner).

As soon as the sensor device 65 reports that a workpiece W which is suitable for the forming process will arrive again in the loading stage 110, causes the

Carrier control 60 returns the gripper tool carrier 20 to its original path of travel, with the workpieces in each of them

Forming steps are passed and the gripper tool carrier 20 then moves along its normal path of movement 21 in its starting position 22 shown in Figures 1 and 2, there to pick up workpieces W and then to transport the next respective forming stage.

FIG. 20 graphically illustrates the above-described movement sequence of the gripping tool carrier 20 in the event of a process disturbance. The movement of the

Gripping tool carrier 20 in the waiting position 27 takes place along a

Motion path portion 24a and the movement of the gripping tool carrier 20 from the waiting position 27 to the position 23 along a movement path portion 24b. The entire movement path from the position 22 via the waiting position 27 to the position 23 is designated by 24. The movement path sections 24a and 24b do not necessarily have the course shown in FIG. The movement of the gripping tool carrier 20 may, for example, along along more alternative

Motion path sections 24a 'and 24b' take place, which the

Motion path sections 21d and 21c and 21c and 21b of the normal

Motion paths 21 correspond. By decoupling the transport device from the drive sträng the

Forming device can be set and varied regardless of the stroke of the forming tools duration and way to transport, ventilation and gripping. By venting is meant here the vertical deflection of the gripping tool carrier 20, wherein the ventilation stroke corresponds to the vertical distance between the two movement path sections 21a and 21c. The from the hub of

Forming tools decoupled adjustment of lifting and gripping movement allows individual adaptation to the respective workpieces, whereby the

Machine wear is reduced. Moreover, this also makes it possible, in case of accidents in the tool room, e.g. if a forming part was not completely pushed out of the forming die or a broken punch in the

Forming die gets stuck or a forming part has been lost from a gripping tool to react to the situation and the gripping tool carrier 20 with its gripping tool units 30 in a secure position, e.g. the said

Waiting position 27 to drive and stop the forming device until the fault is rectified. Thereby, it can be prevented that e.g. Tear off gripping tools or other consequential damage caused to the transport device.

The Greifwerkzeugeinheiten 30 are, as already mentioned, by means of

Gripping tool control 70 individually controllable. As a result, the time for opening and closing can be set individually for each gripper unit. Also, the opening stroke of the gun arms 32a and 32b and the duration of the movement can be matched to the respective workpiece. The same applies to the air movement. This can be optimized for each workpiece in terms of stroke and duration with the aim of acceleration and thus load on the

Keep the construction of the device deep. In contrast, known transport devices with cams must always be designed for the maximum possible stroke with the result that the components at each workpiece or

Forming part of maximum load and thus maximum wear are exposed. In order to compensate for form errors of the blank section or to achieve an eccentric volume predistribution, eg in the production of cams, it is necessary to adjust the first or another gripping tongs off-center. In known transport devices to eccentric A actuating elements are used or the pliers shoes are adjusted by trial and error, that the center of the

Workpiece is shifted by the desired amount from the middle. With the transport device according to the invention, the gripper tool carrier 20 can be moved by the desired amount from the center (zero position) by simply inputting the desired values to the higher-level control 80 by means of the gripper tool carrier drive motors 55 and 56. The relevant gripper is then aligned with a centric adjustment and then the

Gripping tool carrier moved back to its zero position. In this way, a gripping tongs or several gripping tongs can be adjusted eccentrically. The remaining grippers are set when the gripper tool carrier 20 is again in the middle (in the zero position).

The clamping or holding force of each gripper unit 30 is determined by means of

Gripping tool control 70 controlled by the torque of the associated servo motor 33 and can be easily adapted in this way to the workpiece to be held and optionally also varied over the movement cycle of the gripper tool carrier. The clamping force may e.g. when inserting the workpieces in the gripping tongs are set smaller than for transport. The load on the mechanical components is thus only as great as necessary.

Servo motors usually have a rotary encoder for the feedback of the current rotational position to their control. With the encoder, the

Gripper control 70 by simply comparing actual to desired rotational position to determine whether a gripping tool is filled or empty, e.g. if a workpiece has been lost from a gripping tool, so that the forming device can be stopped if necessary. By appropriate training of

Gripping tool control 70 can be detected in this way, process disturbances caused, for example, by skewed workpieces in the gripping tools or a tearing open the gripping tools. In this case, this signals the gripper tool controller 70 of the carrier controller 60 suitably, and the carrier controller 60 then causes the gripper tool carrier 20 with the gripper tool units 30 in a safe position, such as said waiting position 27, driven and stopped there until the process fault is corrected. The risk of tearing open a gripping tool arises, for example, when a workpiece is incompletely pushed out of the die or the press ram breaks and gets stuck in the workpiece. When trying to transport the workpiece, the gripping tool would be torn open. However, the gripper tool controller 70 recognizes this early on and causes the carrier control 60 to retract the

Gripping tool carrier, so that the tearing of the affected gripping tool is prevented. Subsequently, the gripping tool carrier 20 with the

Gripping tool units 30 in a secure position, e.g. the mentioned waiting position 27, driven and stopped there until the process fault is corrected. The

Forming device is naturally stopped during this time. In this way it is possible to react immediately to a process malfunction before major damage occurs. The cooperation of the gripping tool control 70 with the

Carrier control 60 is symbolized in FIG. 18 by the arrow 71.

The gripper tools or gripping tongs of the transport device shown have parallel tong arms 32a and 32b, which are moved linearly toward and away from each other. Such gripping tongs have the advantage over gripping tongs with pivotable gripper arms that the pliers shoes dive uniformly into the gripping diameter. If the tong shoes engage the workpiece at the same angle on both sides, they are pressed in by the same amount when the workpiece is inserted. This reduces the risk of a workpiece being pushed obliquely into the gripping tongs.

Claims

claims

1. Transport method for converting workpieces between a plurality of successive stages (110, 120, 130, 140, 150) of a processing device (M), in particular a forming device, wherein the workpieces (W) in each case simultaneously by means of a plurality of jointly movable gripper tools (32a, 32b) transported in a transport cycle from one stage to the next successive stage of the processing device (M), characterized in that in the presence of a process disturbance of the transport cycle is interrupted and the gripping tools (32a, 32b) with the workpieces (W) in a waiting position (27) , in which the workpieces (W) outside the range of action of

Machining tools (112, 122, 132, 142, 152) of the stages (110, 120, 130, 140, 150) of the processing device (M) are moved, and that resumed after elimination of the process disturbance of the transport cycle of the workpieces (W) becomes.

2. The method of claim 1, wherein the process disturbance is caused by a missing or non-processing suitable workpiece (W) in a loading stage (110) of the processing device.

3. The method according to claim 1 or 2, wherein the process disturbance is caused by a missing or incorrectly inserted into a gripping tool (32a, 32b) workpiece (W).

4. The method according to any one of claims 1-3, wherein the process disturbance is caused by a damaged part of a gripping tool (32a, 32b) or a damaged part of the processing device.

5. The method according to claim 2, characterized in that the absence or presence of a non-workable workpiece (W) by means of a

Sensor device (65) is detected, wherein the movement of the gripping tools (32a, 32b) in the waiting position (27) on the initiative of the sensor device (65).

A method according to claim 3, characterized in that the absence or presence of a workpiece (W) incorrectly inserted into a gripping tool (32a, 32b) is detected by means of a gripper tool control (70) of a gripper tool drive (33), wherein moving the gripping tools (32a, 32b) in the

Waiting position (27) at the behest of the gripper tool control (70) takes place.

7. Transport device for carrying out the method according to one of

Claims 1-6, comprising a movably mounted gripping tool carrier (20) on which a plurality of gripper tools (32a, 32b) for gripping a respective workpiece (W) are arranged, and a motorized gripper tool carrier drive (51-56) for reciprocating movement of the Gripping tool carrier (20) with the gripping tools (32a, 32b) between the stages of the processing device, characterized

characterized in that the gripping tool carrier drive (51-56) is adapted to the gripping tool carrier (20) with the gripping tools (32a, 32b) in a

Waiting position (27) to move, and that it has a carrier control (60) for the Greifwerkzeugträgerantrieb (55, 56) which is adapted to control the movement of the gripping tool carrier (20) and the Greifwerkzeugträger (20) due to a control command supplied thereto with the gripping tools (32 a, 32 b) by means of the gripper tool carrier drive s (55, 56) to move to the waiting position (27) and to interrupt the transport of the workpieces.

8. Transport device according to claim 7, characterized in that the gripping tool carrier (20) is on the one hand linearly movably mounted and on the other hand by means of a Parallelogrammführungsanordnung (11-16) is mounted deflectable transversely to its linearly guided mobility.

9. Transport device according to claim 8, characterized in that the gripping tool carrier (20) by means of a two crank gear assemblies (51-54), each with an associated gripping tool carrier drive motor (55, 56) comprising gripping tool carrier drive (51-56) is movable, each

Crank gear arrangement (51-54) one of the assigned

Gripping tool carrier drive motor (55, 56) rotatably driven crank (51, 52) and a drive rod (53, 54) which is connected to the crank (51, 52) on the one hand and the gripping tool carrier (20) on the other hand articulated.

10. Transport device according to one of claims 7-9, characterized in that the gripping tool carrier (20) with the gripping tools (32 a, 32 b) by means of

Gripping tool carrier drive (51-56) in a forward movement along a first linear movement path (21a) and in a return movement along a parallel to the first linear movement path second linear movement path (21c) is movable.

11. Transport device according to claim 7, characterized in that it has a sensor device (65) for detecting a process fault caused by a missing or non-processing workpiece (W) and for signaling the same to the carrier control (60) ,

12. Transport device according to one of claims 7-11, characterized in that the gripping tools (32a, 32b) depending on the gripping tool carrier (20)

arranged gripper tool drive (33) for the individual actuation of

Gripping tools (32a, 32b) and a gripper tool control (70) is assigned, which is adapted to the opening and closing movements and the

Clamping force of the individual gripper tools (32 a, 32 b) to control individually and to recognize a by an empty gripping tool or an incorrectly inserted into a gripping tool workpiece caused process disturbance and the

Carrier control (60) to signal.