KR20190003519A - Carrying device with gripping forceps - Google Patents

Abstract

In a transport apparatus for transporting workpieces in a multi-station forming device, gripping tools 32a, 32b, each consisting of gripping tongs for gripping one workpiece each, Are arranged on the support. The gripping tools 32a and 32b are each assigned a gripping tool drive which is arranged on the gripping tool support for separate operation of the gripping tools 32a and 32b to grip or release the workpiece. The gripping tools each have two gripping arms (32a, 32b) which are linearly movable to and away from each other by respective gripping tool drive portions. The gripping tool actuators are each configured to be servo-controlled electrically or hydraulically. The gripping tongs having tongue arms (32a, 32b) which are linearly moveable toward and away from each other come into contact with gripping tongues having pivotable gripping arms that evenly reach the gripping diameter and engage the workpiece at the same angle on both sides And the like. The servo-controlled configuration of the gripping tool actuators makes it possible to control the position of the gripping arms.

Description

Carrying device with gripping forceps

The present invention relates to a transport apparatus for workpiece transport in a forming device comprising at least two stations according to the premise of claim 1.

In mass-forming and also in other shaping operations, the workpiece is often passed through a plurality of stations of the molding device in succession, and the workpiece is carried from the station to the station. In a molding device, a station is typically a loading station and various molding stations. To carry the workpiece from the station to the station, a conveying device is provided which is equipped with a tongs-like gripping tool and operates in accordance with the rhythm of the molding device, and the gripping tool simultaneously grips the workpiece, Supply to the next station and release.

In the case of a known molding device, the transport movement and the operation of the gripping tool are coupled to the power train of the molding device. (See, for example, CH 595 155 A)

A typical conveying device for conveying a workpiece in a forming device is described in EP 1 048 372 B1. In this known transport device, a plurality of gripping tools, each gripping tong, each having a dedicated gripping tool drive separate from the power train of the molding device, are arranged on a common grip support which is longitudinally and laterally movable , All gripping clamps are carried back and forth between the two adjacent stations of the molding device in each case. The gripping tongs are pivotable toward and away from each other, including two pivot arms driven by a servo motor via a kinematic coupling member.

The problem with conventional conveying devices is that, for example, in the case of process disturbances caused by incorrectly inserted workpieces into the gripping tool or by damaged parts such as, for example, broken gripping tools or broken punches , It is impossible to react immediately, often resulting in considerable damage to the conveying device or the molding device.

In this context, the fundamental problem of the present invention is to improve the conveying apparatus of the kind mentioned at the outset, and the effect that the process disturbance caused by incorrectly inserted workpieces into the gripping tool can be reduced.

This problem is solved by the conveying device according to the present invention as defined in the independent patent claim 1. [ Particularly advantageous developments and embodiments of the present invention will be apparent from the dependent patent claims.

The core of the invention is as follows: a conveying device for conveying a workpiece in a forming device comprising at least two stations is constituted by gripping tongs movable back and forth between the stations of the forming device and for gripping one workpiece, respectively And at least two gripping tools are arranged. The gripping tools are each assigned a gripping tool drive, which is arranged on the gripping tool support, for the respective operation of the gripping tool to grip or release the workpiece. The gripping tools constituted by gripping grippers each have two gripping arms which are linearly movable towards and away from each other by a respective gripping tool drive. The gripping tool actuators are each configured to be servo-controlled electrically or hydraulically.

It is possible to avoid errors during gripping of the workpieces as a result of the gripping tongs comprised of the tongue arms which are linearly movable towards and away from each other. The gripping grippers having tongue arms that are linearly moveable toward and away from each other are configured for gripping grippers having pivotable tonger arms that evenly reach the gripping diameter when engaging the workpiece at the same angle on both sides . This reduces the risk of the workpiece being skewed into the grippers. By means of a gripping tool drive individually assigned to each gripping grippers, each gripping gripper can be individually adjusted and operated. As a result of the electrical or hydraulic arrangement of the gripping tool actuators, the required swiftness can be achieved and the servo control makes it possible to control the position of the gripping arms.

Advantageously, the pawl arms are each arranged on a respective tong carriage slidably mounted on a tong body, wherein the pawl carriage is connected to a respective toothed rod, And the toothed rod engages with a motor-driveable drive pinion, a gripper carriage and, accordingly, a pivot arm movable in the opposite direction by a drive pinion. This represents a structurally simple implementation of the linear movement of the forceps arms.

Advantageously, the pawl arms are arranged on the pawl carriage and are adjustable thereto. The forceps arms can thus be simply adjusted to the workpiece.

Each gripping tool drive has advantageously (electric) servomotors with rotary encoders for opening and closing gripping tools. Servo motors, taking into account the range of possible control options, are particularly suited to drive motors or positioning motors (through torque) and also allow detection (feedback) of the forces exerted by the gripping tools.

Advantageously, the gripping tool drive is assigned a gripping tool controller configured to individually control the opening and closing movement of the individual gripping tools. The gripping tool controller is advantageously configured to individually control the clamping forces of the individual gripping tools. This allows optimal adjustment to specific requirements. In particular, for example, the clamping force is smaller than when the workpieces are being introduced into the gripping clamps for control purposes. The loading on the mechanical components is thus only as high as necessary.

Most particularly advantageously, the gripping tool controller is configured to recognize a process failure caused by an empty gripping tool or a workpiece that is incorrectly inserted into the gripping tool. This configuration allows process failures to be recognized at an early stage and consequently reduces any damage that occurs.

Particularly advantageously, the gripping tools are provided with a four-point support arrangement for gripped workpieces, and the four-point support arrangement is formed by a gripper shoe. This enables the workpiece to be particularly safe to hold and reduces the risk of workpiece tipping when introduced into a closed gripper.

Are disclosed herein.

The present invention is described in more detail below with reference to exemplary embodiments shown in the drawings.
Figures 1-6 are schematic and cross-sectional views of a molding device at various stages of a task sequence.
Fig. 7 is an overall perspective view of the delivery device of the molding device according to Figs. 1 to 6. Fig.
8 is a front view of the conveying device.
9 is a side view of the conveying device.
Fig. 10 shows a cross section through the conveying device along the line XX in Fig.
11 is a perspective view of the gripping tool unit of the conveying device.
12 is a rear perspective view of the gripping tool unit of Fig.
13 is a front view of the gripping tool unit of Fig.
Figure 14 shows a cross-sectional view through the gripping tool unit according to line XIV-XIV in Figure 13;
15 is a side view of the gripping tool unit according to Fig.
Figure 16 shows a cross-sectional view through the gripping tool unit according to line XVI-XVI in Figure 15;
Fig. 17 shows a cross section through the gripping tool unit according to line XVII-XVII in Fig. 15;
18 is a schematic diagram of the control arrangement of a molding device or its delivery device.
Figure 19 shows the schematic path of movement of the gripping tool of the conveying device during normal operation.
Figure 20 shows a schematic path of movement of the gripping tool in the event of a process failure.

The following observations apply in relation to the following explanations. For clarity of illustration, reference numerals are included in the drawings, but are not referred to in a directly related part of the description, and are to be referred to for the purpose of describing reference numerals before or after the description. On the other hand, to avoid the complexity of the figures, less relevant reference numerals for immediate understanding are not included in all figures. In this case, other drawings should be referred to.

A schematic outline of the drawings 1 to 6 shows parts of a molding device according to the present invention in order to understand the present invention. Fig. 1 is a front view along line I-I in Fig. 2, and Fig. 2 is a cross-sectional view along a line II-II in Fig. Correspondingly, Figs. 3 and 5 are front views and Figs. 4 and 6 are related cross-sectional views.

In the illustrated exemplary embodiment, the forming devices generally indicated by reference numeral M include five stations 110, 120, 130, 140, 150 arranged side by side, and the first station 110 And the other stations 120, 130, 140, 150 are molding stations. The forming stations 120,130, 140 and 150 are formed by four forming die 121, 131, 141 and 151 arranged in a common die holder 101, four forming tools 122, 132,142 and 152 and four ejection elements 123,133,143 and 153 which can be punched out of the mold by the workpiece W formed on the molding die. The loading station 110 includes a front end device 112 for shearing the workpiece W from a bar material (not shown, supplied by the bar material supply device, not shown) and the discharge element 113, (W) can be discharged from the front end device (112). The conveying device generally indicated by reference character T serves to convey the workpiece from one station to the next station of the forming device M. [ 1 to 6 show only gripping tools each having a pair of grip arms 32a and 32b, respectively.

During operation of the molding device, the gripping-type gripping tool of the transport device T formed by the pair of gripping arms 32a, 32b at the starting position is maintained in the loading station 110 at the ready state or at the molding stations 120, 130 131, 141, and 151 of the molding apparatuses (140, 150) (FIGS. 1 and 2) and then simultaneously transfer the workpiece W to the respective molding devices And the finished workpiece W picked up from the last forming station 150 can be released and released from the molding device. Figures 3 and 3 Figure 4 illustrates this. In the molding stations 120, 130, 140 and 150, the workpiece W is inserted into the molding dies 121, 131, 141 and 151 and molded by the punches 122, 132, 142 and 152. The transport device T then returns the (empty) gripping tool to the starting position shown in Figs. The gripping tool can be held in the loading station 110 or pick up the new workpiece W discharged from the molding dies 121, 131, 141 and 151 of the molding stations 120, 130, 140 and 150, 3 and 4, the workpiece is carried back to the next station of the molding device. The entire sequence takes place in the transport cycle in accordance with the rhythm of the molding device M. [

It is clear from the above brief description of the transfer operation that in each transfer cycle each gripping tool carries a different workpiece and each pair of adjacent stations of the molding device is supplied by a different gripping tool. In the context of the present invention, the transfer of a workpiece from a station to a station of a forming device by a plurality of gripping tools must be understood in this sense.

The shaping device M shown so far corresponds to this type of conventional shaping device in the mode of construction and mode of operation so that a person skilled in the art does not require further explanation in this regard.

The conveying device of the molding device M will be described in detail below with reference to Figs. The conveying apparatus generally indicated by reference character T comprises a fixed frame 10, a plate-like gripping tool 10 movably arranged in or on the frame 10 and supporting five gripping tool units 30 in this example, A support portion 20, and a gripping tool support driving portion. The gripping tool units 30 are all arranged at the same distance from the common reference plane E (Fig. 7). The front face of the plate-like gripping tool support 20 facing the gripping tool unit is aligned parallel to the reference plane E. The gripping tool support drive includes two gripping tool support drive motors 55 and 56, each of which is configured as a servomotor with rotary encoder and gearing and is rigidly mounted on the frame 10. The tool support driving portion includes two crank gear arrays (each having two crank gears 51 and 52 and a connecting rod 53 and 54) (Not shown) of the molding device M, respectively, in a specific application, such that the frame 10 is fixedly mounted on a rotatable portion of the gearing of the forming device 55, 56, Removable and pivotably mounted so that access to the molding die and molding tools can be easily obtained.

In the frame 10, two parallel guide rods 11, 12 (Figures 7 to 10) are arranged and their axes define a reference plane E (Figure 7). The two link rods 13, 14 are guided along or on the guide rods 11, 12 so as to be linearly movable in the longitudinal direction of the guide rods. In addition, the two link rods 13, 14 are pivotally connected to each one of the two guide rods 11, 12, respectively. At its end remote from the guide rods, the link rods 13,14 are pivotally attached to the gripping tool support by the journal pair 15,16 (Figs. 9 and 10). The distance between the two journal pairs 15, 16 is equal to the distance between the two guide rods 11, 12. The distance between the journal pair 15 and the guide rod 11 is equal to the distance between the journal pair 16 and the guide rod 12. The two parallel guide rods 11 and 12 and the two link rods 13 and 14 together with the gripping tool support 20 form a parallelogram guide arrangement for the latter and the gripping tool support 20 (Upward and downward in the drawing) in the transverse direction with respect to the longitudinal direction of the guide rods 11, 12. In Fig. 7 this is symbolized by a double arrow 25. At the same time, through the slidably mounted link rods 13, 14, the gripping tool support 20 is movable back and forth along the guide rods 11, 12 in the longitudinal direction thereof in the guided path, 26 in Fig. Thus, the gripping tool support 20 is guided so as to be linearly movable parallel to the reference plane on the one hand and laterally displaceable relative to its linear movement substantially parallel to the reference plane E Respectively.

Each of the drive rods (connecting rods) 53 and 54 is rotatably connected by one end on the cranks 51 and 52 and by its other end on the gripping tool support 20, respectively. The grasping tool support 20 can be moved in the desired direction (within a predetermined range) by means of the bi-directional arrow 26 and / Or in the direction of the bi-directional arrow 25.

The advantage of the parallelogram guide is that the gripping tool support 20 performs only a small movement perpendicular to its displacement movement, i.e. perpendicular to the reference plane E, during its lateral displacement (pivotal movement relative to the guide rod) will be.

Fig. 19 schematically illustrates a typical path of the gripping tool support 20 and thus the gripping tool unit 30 attached thereto. The closed circulation path 21 of movement includes four movement path sections 21a-21d. The two linear travel path sections 21a and 21c correspond to the linearly guided sliding movements of the gripping tool support 20 along the guide rods during the move and return movements between the stations of the advancing device, The path sections 21b and 21d are caused by displacements of the gripping tool support 20 by the parallel slant type guide arrangement. Points 22 and 23 indicate the start position of the gripping tool support 20 shown in FIG. 1 and its position displaced by one station shown in FIG. 3, respectively. 19, the forward movement of the gripping tool support 20 occurs along the first linear path (movement path section 21a) of movement, while the return movement of the gripping tool support 20 occurs along the first linear path And along a linear movement path (movement path section) 21c parallel to the linear movement path. The distance between the two linear travel paths resulting from the displacements of the gripping tool support 20 is selected such that the gripping tool unit 30 arranged on the gripping tool support 20 at the level of the second linear travel path, 132, 142, 152 at the forming stations 120, 130, 140, 150, as can be seen from Fig. Reference numeral 27 denotes a standby position, which will be discussed further below.

The gripping tool units 30 arranged side by side on the gripping tool support portion 20 are all configured identically. The structure will be apparent from Figs. 11 to 17.

Each gripping tool unit 30 includes a gripping body 31, a pair of movable gripping arms 32a and 32b forming gripping grips, and a (servo) motor 33 having a rotary encoder and gearing And a gripping tool driving section, and the servo motor is shown only in Figs. 9 and 14. The clamping body 31 and the servomotor 33, including gearing, are mounted on the gripping tool support 20, respectively. The two pawl arms 32a, 32b are movably arranged on the pawl body 31.

In the pawl body 31, the two pawl carriages 35a, 35b are displaceably mounted on the three guide rods 34a, 34b, 34c. The gripper carriages 35a and 35b are each kinematically connected to the respective toothed rods 37a and 37b through drive rods 36a and 36b respectively so that the movement of the toothed rod results in the accompanying movement of the gripper carriage, The opposite is true. The two toothed rods 37a and 37b mesh with the drive pinion 38 on the diagonally opposite side thereof and the drive pinion is rotatably driven by the servo motor 33 (through its gear ring) The two toothed rods 37a and 37b move in opposite directions so that the two gripper arms 32a and 32b are moved toward each other or away from each other. The opening or closing movement of the gripping grippers formed by the gripper arms 32a, 32b is thus influenced by the servo motor 33 or the driven drive pinion 38 accordingly.

The gripping tool drive may alternatively be in the form of a servo-controlled hydraulic drive (with a servo valve). The important thing in this case is that the movement of the gripping clamps can be influenced very quickly and in particular by the position control and on the other hand the clamping force of the two clamping arms can be precisely adjusted or controlled and feedback And the same applies to the above-described gripping tool drive having the electric servomotor.

At the free end of the two gripper arms 32a, 32b, tong shoes 39a, 39b, which are provided to grip the workpiece and are replaceably attached, are arranged so that the gripper can easily match the shape of the gripping workpiece (Fig. 11). The tongs need not be constructed and / or arranged in the same way on all grippers. Preferably, on each tongue arm, two tongs are arranged which together form a four-point support arrangement particularly advantageous for the workpiece being gripped, as shown. This four-point support arrangement on the one hand allows the workpiece to be safely maintained and on the other hand reduces the risk of workpiece tipping when introduced into a closed gripper.

The pawl arms 32a and 32b are releasably connected to the pawl carriages 35a and 35b, respectively, via a pair of serrated plates 40a and 40b (Figs. 15 and 17). In this way, for example, the forceps arms 32a, 32b can be easily adjusted laterally or at a height relative to each forceps carriage 35a, 35b, to adjust the gripping forceps on a particular workpiece.

18, the transport apparatus T also includes a support controller 60 for the gripping tool support drive motors 55, 56 and a gripping tool drive motor 33 for the individual gripping tool unit 30. [ And a gripping tool controller (70) for operating the gripping tool. The gripping tool controller 70 is configured to individually control the opening and closing movement and tightening forces of the individual gripping tools, here the gripping tongs 32a, 32b. The support controller 60 calculates the rotated positions of the two cranks 51 and 52 required to move along the movement path 21 of the two gripping tool supports 20 and accordingly adjusts the position of the servomotors 55 and 56, . The support controller 60 also includes a sensor configured to recognize a process failure caused by the unworkable or missing workpiece W ' in the loading station 110 and signal the failure to the support controller 60, for example, Device 65. < / RTI >

The sensor device 65, which is only indicated symbolically in Figures 2, 4 and 6, may be assigned to the aforementioned material supply device (not shown) and be, for example, a light-shielding arrangement. Such a sensor device on a bar feed device is known per se and is described, for example, in EP 1 848 556 B1. The sensor device 65 can recognize the start and end of the bar. When the sensor device 65 recognizes the start or end of the bar, it signals it to the support controller 60 so that the support controller is informed that the next bar section is defective and must be discarded, I know. The support controller 60 then responds to process failures in a manner that is described in more detail below.

The support controller 60 and the gripper tool controller 70 are also connected to a higher-level controller (not shown) which, among other things, makes a connection to the molding device and specifies the position of the gripping tool support or the movement path 80). By the host controller 80, the operator can also enter or modify settings relating, for example, to the movement of the gripping tool support or the opening and closing movement of the gripping gripper. It will be appreciated that the functions of the support controller 60, the gripping tool controller 70, and the host controller 80 may also be implemented in some other configuration, for example, a single controller.

As already mentioned at the outset, in shaping devices, in particular in hot-shaping devices, the raw material is usually supplied in the form of bars with pieces of appropriate length being sheared. The beginning and end of the bars are not allowed to enter the molding process and must be discarded. The discarded portions are missing from the molding process to create an empty molding station in the molding device, which should be avoided for the reasons initially described.

The driving parts of the gripping tools 32a, 32b arranged on or in the gripping tool support 20 are independent and separate from the powertrain of the molding device, .

For example, if the mentioned sensor device 65 senses a process failure by a missing workpiece or by a workpiece W 'that is to be discarded in a subsequent process (Figures 5 and 6) 65 send control commands corresponding to the support controller 60 for the gripping tool support driver. The support controller 60 then moves the gripping tool support 20 with the gripping tool unit 30 away from its conventional travel path 21 (Fig. 19) Causing the gripping tool support 20 having the workpiece W to be moved into the standby position 27 (Fig. 20). The standby position is located on the upper travel path section 21c of the gripping tool support 20 and the gripping arms 32a and 32b of the gripping tool unit 30 are positioned on the upper moving path section 21c of the gripping tool support 20, , 142, 152) and out of the latter range. This situation is shown in Fig. 5 and Fig. The forming tools then perform an empty stroke, but this has no disadvantageous results because all the stations are empty. Preferably, the cooling of the tools during this step is stopped, so that the tools and workpieces located in the standby position are not cooled. The defective workpiece W 'is discarded (in a manner known per se).

As soon as the sensor device 65 reports that the workpiece W suitable for the molding process arrives at the loading station 110 again, the support controller 60 causes the gripping tool support 20 to return to its original travel path , The workpiece is transferred to its respective forming station and gripping tool support 20 and then into its starting position 22 shown in Figures 2 and 2 along its normal travel path 21 with a workpiece W at that position Pick up and transport to each subsequent molding station.

20 schematically illustrates the movement sequence of the gripping tool support 20 described in the case of a process failure. The movement of the gripping tool support 20 into the standby position 27 occurs along the movement path section 24a and the movement of the gripping tool support 20 from the standby position 27 to the position 23 causes the movement path section 24b ). The entire movement path from the position 22 to the position 23 via the standby position 27 is indicated by reference numeral 24. The movement route sections 24a and 24b do not necessarily follow the process shown in Fig. The movement of the gripping tool support 20 may also include alternative travel path sections 24a ', 24b', respectively corresponding to, for example, the travel path sections 21d and 21c, 21c and 21b of the normal travel path 21 .

Separating the conveying device from the power train of the forming device allows the duration and path for conveying, lifting and gripping to be adjusted and varied independently of the stroke of the forming tools. The " lifting " will be understood here as the vertical displacement of the gripping tool support 20, and the lifting stroke corresponds to the vertical distance between the two travel path sections 21a and 21c. Adjustment of lifting and gripping movements separate from the stroke of the forming tools allows for individual adjustment to specific workpieces, resulting in reduced wear on the machine. Also, if a problem arises in the tool chamber, for example if the molded part is not fully pushed out of the mold or if a broken punch is embedded in the molding die or if the molded part is lost from the gripping tool, It is possible to move the gripping tool support 20 with its gripping tool unit 30 in response to a safety position, for example into the mentioned stand-by position 27, and to stop the molding device until the obstacle is resolved. This makes it possible, for example, to prevent the gripping tool from being broken or other resultant damage being caused to the conveying device.

As already mentioned, the gripping tool unit 30 is individually controllable by the gripping tool controller 70. As a result, the points of opening and closing can be individually adjusted for each gripping tool unit. The open stroke and travel duration of the forceps arms 32a, 32b may also be applied to the workpiece. The same is true for lifting movements. The movement can also be optimized for each workpiece with respect to stroke and duration for the purpose of maintaining acceleration and thus loading the structure of the device low. In contrast, known conveying devices with control curves always have to be designed for the maximum possible stroke, so that the components are subjected to the maximum load and hence the maximum wear in the case of all workpieces or molded parts.

In order to compensate for defects in the form of an empty section or to achieve predistribution off the center of the material, for example in the production of the cam it is essential that the first gripper or another gripper be located off- to be. In known conveying arrangements, the eccentric adjustment elements are used for that purpose or the center of gravity of the workpiece is shifted from the center by the desired amount since the grip shoe is adjusted by trial and error. The conveying device according to the present invention allows the gripping tool support 20 to be moved off center by a desired amount by the gripping tool support drive motors 55 and 56 by simply inputting a desired value to the host controller 80 . The associated gripping clamps are then aligned with the central adjustment elements and then the gripping tool support is again moved into its zero position. In this way it is possible for one or more gripping clamps to be located off-center. The remaining gripping clamps are adjusted when the gripping tool support 20 is again at the center (zero position).

The clamping force or holding force of each gripping tool unit 30 is controlled by the gripping tool controller 70 through the torque of the associated servomotor 33 and is maintained in this way and is selectively changed over the period of the gripping tool support Can be simply adjusted. The clamping force can be adjusted, for example, to be smaller when the workpiece is introduced into the gripper than for transporting. Therefore, the load on the mechanical component is only as high as necessary.

The servomotor usually has a rotary encoder to feed back the current rotated position to its controller. Using the rotary encoder, the gripping tool controller 70 can easily determine whether the gripping tool is loaded or empty, for example, whether the workpiece has been lost from the gripping tool, by comparing the desired rotated position with the actual rotated position, The molding device can be stopped. It is also possible, for example, to recognize a process fault caused by a workpiece positioned skewly in the gripping tool or by a tearing open gripping tool by a suitable configuration of the gripping tool controller 70. In such a case it is signaled to the support controller 60 by the gripping tool controller 70 in an appropriate manner and then the support controller 60 moves the gripping tool support 20 with the gripping tool unit 30 to a safe position, For example, into the mentioned standby position 27, where it is stopped until the process fault is resolved. The gripping tool may be torn open, for example, when the workpiece is ejected incompletely from the die or when the punch is broken and sticks to the workpiece. In an attempt to transport the workpiece, the gripping tool will tear open. However, the gripping tool controller 70 recognizes this at an early stage and causes a return movement of the gripping tool support via the support controller 60 to prevent the gripping tool from tearing open. The gripping tool support 20 with the gripping tool unit 30 is then moved into a secure position, for example into the mentioned stand-by position 27, where it is stopped until the process failure is resolved. The molding device is, of course, stopped during that time. In this way, it is possible to react immediately to process failures before more damage occurs. The cooperation of the support controller 60 and the gripper tool controller 70 is symbolized by the arrow 71 in Fig.

The gripping tools and gripping tongs of the described conveyor have parallel gripper arms 32a, 32b which are moved linearly towards each other and away from each other. Such gripping tongs have advantages over gripping grips having pivotable gripping arms that uniformly reach into the gripping shoe gripping diameters. When the toggle shoe engages the workpiece at the same angle on both sides, it is pressed against it by the same amount upon introduction of the workpiece. This reduces the risk of the workpiece being skewed into the gripper.

Claims (8)

A conveying device for conveying a workpiece in a forming device (M) comprising at least two stations (110, 120, 130, 140, 150)
A gripping tool support portion (20) in which at least two gripping tools (32a, 32b) constituted by gripping clamps for gripping one workpiece (W) are movable back and forth between the stations of the molding device, Lt; / RTI >
The gripping tools 32a and 32b are each assigned a gripping tool driving part 33 and arranged on the gripping tool support part 20 and configured to grip the gripping tools 32a , ≪ / RTI > 32b,
Characterized in that the gripping tools each have two gripper arms (32a, 32b) which are linearly movable to and away from each other by the respective gripping tool drive (33).
The method according to claim 1,
The forceps arms 32a, 32b are each arranged on respective forceps carriages 35a, 35b slidably mounted on the forceps body 31;
The clamping carriages 35a, 35b are each kinematically connected to respective toothed rods 37a, 37b;
The toothed rods 37a and 37b are rotatably supported by a motor-driveable drive pinion 38, the pintle carriages 35a and 35b and the drive pinions 38, 32b). ≪ / RTI >
3. The method of claim 2,
Characterized in that the gripping arms (32a, 32b) are arranged on the gripper carriages (35a, 35b) and adjustable therewith.
3. The method according to claim 1 or 2,
Wherein each of said gripping tool driving portions has a servo motor (33) having a rotary encoder for opening and closing said gripping tools (32a, 32b).
5. The method according to any one of claims 1 to 4,
Characterized in that the gripping tool drive (33) is assigned to a gripping tool controller (70) configured to individually control the opening and closing movement of the individual gripping tools (32a, 32b).
6. The method of claim 5,
Characterized in that the gripping tool controller (70) is configured to individually control the fastening forces of the respective gripping tools (32a, 32b).
The method according to claim 5 or 6,
Characterized in that the gripping tool controller (70) is configured to recognize and signal a process fault caused by a blank gripping tool or by a workpiece (W) incorrectly inserted into the gripping tool.
8. The method according to any one of claims 1 to 7,
Characterized in that the gripping tools (32a, 32b) are provided with a four-point support arrangement for the gripped workpieces, and the four-point support arrangement is formed by the gripper shoes (39a, 39b).

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