DE102017121557B4 - Process and device for conveying and positioning workpieces - Google Patents

Abstract

Method for conveying and positioning workpieces (62, 64), in which the workpieces (62, 64) are conveyed on a continuous conveying device (60) in a throughput direction (A), with at least one first workpiece (62) being moved relative to at least one second workpiece (64) is positioned, which maintains its position on the continuous conveyor (60), such that the at least one first workpiece (62) and the at least one second workpiece (64) have a defined orientation relative to one another on the continuous conveyor ( 60), and in a subsequent transfer step, the at least one first workpiece (62) and the at least one second workpiece (64) are simultaneously picked up by a transfer device (40) from a pick-up position (P1) in their defined orientation by the continuous conveyor (60). and transferred to a defined storage position (P2).

Description

The present invention relates to a method for conveying and positioning workpieces and a corresponding device.

In many manufacturing processes, workpieces are placed one after the other in various processing stations, from which they are removed in a further processed state and transported on. For example, such a processing station can be a press in a press line in which essentially plate-shaped workpieces are processed in successive pressing steps. The workpieces are first conveyed on a continuous conveyor in the direction of a press, picked up by the continuous conveyor and inserted into the press. This continuous conveying device can be, for example, but not limited to, a conveyor belt on which the workpieces are conveyed in succession.

In order to optimize the workflow and the processing speed in such a press line, it is advantageous to first align the workpiece on the conveyor belt in a position correction step before it is picked up by a transfer device in a subsequent transfer step and transferred to a defined deposit position in the press. This is necessary in particular when the transfer device which carries out the transfer step is equipped to receive and transfer a number of workpieces at the same time. The workpieces to be picked up at the same time must then assume a defined alignment relative to one another on the conveyor belt before the transfer step can be carried out.

EP 2 190 604 B1 discloses such a method in which the position correcting step preceding the transfer step for transferring the work piece(s) to the press is performed by positioning means located adjacent to the conveyor belt and operating independently of the transfer device. The positioning device shown in this prior art is formed, for example, by an articulated robot that can pick up a single part from the conveyor belt and correct its position. Also shown is the possibility of correcting the positions of several workpieces at the same time using two positioning devices, which is associated with increased effort and correspondingly high costs.

DE 10 2017 111 800 A1 discloses a method for aligning two workpieces to form a joint, wherein in a longitudinal alignment step the first workpiece is aligned relative to the second workpiece along at least one of the workpiece edges by linear movement of at least one of the grippers relative to the other gripper, and wherein the longitudinal alignment step takes place during the transport of the Workpieces is carried out from the delivery station to the processing station.

It is therefore an object of the present invention to further develop such a method for conveying and positioning workpieces in such a way that a plurality of workpieces can be handled simultaneously by a single conveying device with comparatively little effort.

This object is achieved according to the invention by a method according to claim 1 and by a corresponding device according to claim 6.

According to the invention, at least one first workpiece is positioned relative to at least one second workpiece in the position correction step. The latter retains its position on the continuous conveyor, i.e. it is not subjected to any position correction. Only the at least one workpiece is arranged in such a way that after the position correction, the at least one workpiece and the at least second workpiece assume a defined orientation relative to one another, from which both workpieces can be transferred to the defined storage position in the subsequent transfer step.

In this case, it is therefore no longer necessary to correct the position of all the workpieces that are transferred in the transfer step, but rather only a part of these workpieces is positionally corrected in relation to the remaining part. In the simplest case, a single first workpiece is repositioned relative to a single second workpiece. However, a plurality of first workpieces can also be positioned relative to a second workpiece, positioned relative to a plurality of second workpieces, or a plurality of first workpieces are positioned relative to one or more second workpieces. All of these cases should be covered by the phrases "at least one first workpiece" and "at least one second workpiece".

A positioning device that carries out the position correction must therefore only be set up to detect a part of the workpieces to be transferred and to arrange them relative to the one or more others. This significantly simplifies the construction of the entire system.

Preferably, before the position correction step, actual positions of the at least one first Workpiece and the at least one second workpiece on the continuous conveyor optically detected. This can be done, for example, by an image acquisition device or another type of optical scanning device, either during the continuous passage of the continuous conveyor device, or while the continuous conveyor device interrupts its operation for a brief moment.

More preferably, target positions of the at least one workpiece and of the at least one second workpiece are determined from the detected actual positions, which result in a common, defined alignment.

More preferably, the at least one first workpiece that is positioned relative to the at least one second workpiece in the position correction step is determined on the basis of the detected actual positions. It is therefore advantageously decided which of the workpieces to be transferred is or are to be repositioned relative to the remaining workpiece or workpieces. Naturally, it is favorable to select such a workpiece or workpieces that have to be moved over the shortest distance to correct their position or for whose repositioning the fewest movements have to be carried out. In this way, the implementation of the position correction step can be optimized in terms of time and energy.

According to a further preferred embodiment of the method according to the invention, the transfer device corrects the common spatial orientation of the at least one workpiece and the at least one second workpiece in the transfer step. This means that, for example, an angular orientation of the workpieces to be transferred is corrected during transfer to the defined storage position, while the relative angular orientation of the at least one first workpiece to at least one second workpiece is retained. A correction in the form of a common translational movement of the two workpieces is also possible.

• - eine Stetigfördereinrichtung zur Beförderung von Werkstücken in einer Durchlaufrichtung,
• - eine Positioniereinrichtung, die an der Stetigfördereinrichtung angeordnet ist und Mittel zur Positionierung mindestens eines ersten Werkstücks relativ zu mindestens einem zweiten Werkstück umfasst,
• - eine optische Erfassungseinrichtung, die zur optischen Erfassung von Ist-Positionen des mindestens einen ersten Werkstücks und des mindestens einen zweiten Werkstücks auf der Stetigfördereinrichtung und zur Ausgabe von Daten entsprechend den erfassten Ist-Positionen eingerichtet ist,
• - eine Steuereinrichtung, die zur Steuerung der Positioniereinrichtung auf Grundlage der Daten entsprechend den erfassten Ist-Positionen eingerichtet ist, derart, dass die Positioniereinrichtung das mindestens eine erste Werkstück relativ zu dem mindestens einen zweiten Werkstück derart positioniert, dass das mindestens eine erste Werkstück und das mindestens eine zweite Werkstück gemeinsam eine definierte Ausrichtung relativ zueinander einnehmen,
• - und ein Transfergerät, das zur gleichzeitigen Aufnahme des mindestens einen ersten Werkstücks und des mindestens einen zweiten Werkstücks aus einer Aufnahmeposition in ihrer definierten Ausrichtung und zur Überführung derselben in eine definierte Ablageposition eingerichtet ist.

The present invention also relates to a device for conveying and positioning workpieces, comprising

• - a continuous conveyor for transporting workpieces in one direction,
• - a positioning device which is arranged on the continuous conveyor device and comprises means for positioning at least one first workpiece relative to at least one second workpiece,
• - an optical detection device, which is set up for the optical detection of actual positions of the at least one first workpiece and the at least one second workpiece on the continuous conveyor device and for the output of data corresponding to the detected actual positions,
• - a control device that is set up to control the positioning device on the basis of the data corresponding to the detected actual positions, such that the positioning device positions the at least one first workpiece relative to the at least one second workpiece in such a way that the at least one first workpiece and the at least one second workpiece jointly assume a defined orientation relative to one another,
• - and a transfer device, which is set up to simultaneously pick up the at least one first workpiece and the at least one second workpiece from a pick-up position in their defined alignment and to transfer them into a defined deposit position.

The transfer device is preferably set up to correct the spatial orientation of the at least one first workpiece and the at least one second workpiece in the picked-up state.

• 1 und 2 zeigen eine Ausführungsform einer erfindungsgemäßen Vorrichtung zur Förderung und Positionierung von Werkstücken in zwei unterschiedlichen Positionen, jeweils in einer schematischen Draufsicht.

A preferred exemplary embodiment of the present invention is explained in more detail below with reference to the drawing.

• 1 and 2 show an embodiment of a device according to the invention for conveying and positioning of workpieces in two different positions, each in a schematic plan view.

1 12 is a plan view of the initial portion of a press line, which includes a press 12 with four press stands 16, 18, 20, 22 and a lower tool 32 arranged therein. Workpieces are pressed between this lower tool 32 and an upper tool (not shown) located above it. A transfer device 40 is used to load the press 12, which removes workpieces from a continuous conveyor, in the present case a conveyor belt 60, and transports them in a throughput direction A (in 1 indicated by an arrow), transferred to the press 12 and deposited there. For this purpose, the conveyor belt 60 transports the workpieces in the throughput direction A to an area from which several workpieces can be picked up simultaneously by the transfer device 40 from a pick-up position P1 and transferred to a deposit position P2 on the lower tool 32 of the press 12. In the present embodiment, two workpieces 62, 64 are taken from the transfer device 40 in each case and transferred. In 1 Also shown is a pair of workpieces 74 that have just been transferred to storage position P2.

For this purpose, the transfer device 40 comprises an arm 42, at the end of which a tool holder with a tooling 50 for gripping the workpieces 62, 64 is attached. The tooling 50 is adapted to the respective workpieces 62, 64 and has, for example, vacuum suction cups or the like in order to be able to suck on the workpieces 62, 64 and bring them from the pick-up position P1 into the deposit position P2. The arm 42 extends radially from a vertical axis Z1 and is pivotable about this axis Z1. Furthermore, the arm 42 can be moved in its extension direction in relation to the axis Z1, so that the end of the arm 42 carrying the tooling 50 can be moved closer to or away from the axis Z1. For this purpose, the arm 42 is housed in a suitable housing 46, which allows the arm 42 to pivot and move with respect to the axis Z1, as described above. The receptacle 46 itself can be moved along a rail 44 which extends in the direction A of passage. This allows the receptacle 46 to be moved with the arm 42 in the direction of the press 12 and in the opposite direction to the conveyor belt 60. Up and down movement of the arm 42 along the axis Z1 is also possible in order to be able to lift the workpieces 62, 64 from the conveyor belt 60 and lower them onto the die 32.

So that the workpieces 62, 64 to be transferred can be correctly detected by the tooling 50 of the transfer device 40, it is necessary for them to assume a defined alignment with one another at the end of the conveyor belt 60 in the receiving position P1. In order to ensure this, a positioning device 66 in the form of an articulated robot is provided, which is arranged next to the conveyor belt 60 . At the end of its articulated arm 68, it carries a tooling 70 for receiving a workpiece. If two workpieces 62 and 64 lying next to one another on conveyor belt 60 pass the section of conveyor belt 60 next to which articulated-arm robot 66 is arranged, it can grasp and transfer one of the two workpieces 62 or 64, i.e. lift it onto conveyor belt 60 and into it put it down again in a corrected position. In the present case, the articulated-arm robot 66 is able to optionally correct the position of a first workpiece, in the present case the workpiece designated with the reference number 62, or also the other workpiece 64.

The process of positioning a first workpiece 62 relative to a second workpiece 64 which maintains its position on the conveyor will be referred to hereinafter as the correcting step. After completion of this position correction step, both workpieces, ie the first workpiece 62 whose position has been corrected and the second workpiece 64 which maintains its position on the conveyor belt 60, are jointly in a defined alignment relative to one another. If this is the case, the transfer device 40 can carry out a transfer step in which the first workpiece 62 and the second workpiece 64 are simultaneously picked up from the pick-up position P1 and transferred to the deposit position P2.

To carry out the position correction step, the actual positions of the first workpiece 62 and the second workpiece 64 on the conveyor belt 60 are first recorded. An optical detection device 72 is used for this purpose, which can be an image recognition system, for example. This is capable of outputting data representing the actual positions to a control device, not shown in detail, which is set up to control the articulated-arm robot 66 .

From the actual positions, the control device determines target positions of the first workpiece 62 and the second workpiece 64, which together correspond to the defined orientation. The control device can then control the articulated-arm robot 66 in such a way that it controls the first workpiece 62 and corrects its position, i.e. corrects its position in relation to the second workpiece 64 . The position of the second workpiece 64 thus represents the reference position with respect to which the position of the first workpiece 62 is changed.

In particular, the control device can be provided to select from the two workpieces 62 and 64 the one whose position correction requires the least amount of time and energy, i.e. for whose position correction the articulated-arm robot 66 has to carry out as few movements as possible. In other words, from the data relating to the actual positions of two workpieces, that which is to be relocated (as the first workpiece) with respect to the other (second) workpiece is determined.

In the embodiment in FIG 1 the two workpieces 62 and 64 are designed as square plates with identical dimensions. So that they can be correctly detected by the tooling 50 of the transfer device 40, they must be aligned with one another in the defined alignment in such a way that their edges are aligned and have a predetermined distance from one another. The two workpieces 62 and 64 must therefore be aligned with respect to their angular position and their distance from each other.

For this purpose, the in 1 The upper workpiece is selected as the first workpiece 62, grasped by the articulated robot 66, rotated into a correct angular position with respect to the second workpiece 64 and shifted in position until the defined orientation is achieved. In this orientation, the two workpieces 62 and 64 reach their pick-up position P1, in which they are picked up by the transfer device 40. For this purpose, the workpieces 62, 64, which are aligned in a defined manner relative to one another on the conveyor belt 60, may have to be transported further by the conveyor belt 60 until they reach the pick-up position P1.

However, in order for the two workpieces 62 and 64 to be placed correctly in the placement position P2 within the press, the angle must still be corrected, although their relative position to one another is maintained, i.e. their angular orientation and their distance from one another. While the latter is ensured by the tooling 50 of the transfer device 40, a rotational movement of the tooling 50 can be carried out during the transfer from the conveyor belt 60 into the press 12 to correct the angle between the pick-up position P1 and the deposit position P2. This can be achieved by combined movements of the transfer device 40. Furthermore, additional translational movements of the two workpieces 62 and 64 can be carried out during the transfer.

In 1 the position correction step is complete, i.e. the first workpiece 62 and the second workpiece 64 assume the receiving position P1, in which they have their defined alignment to one another, while the transfer device 40 is still moving a pair of workpieces 74 ahead in the throughput direction A in the press 12 discards. After forming in the press 12, this is removed by a further conveyor device (not shown) and transported onward.

In 2 shows how the transfer device 40 has pivoted its arm 42 with the tooling 50 over the first workpiece 62 and the second workpiece 64 in the pick-up position in order to simultaneously grasp both workpieces 62, 64 and transfer them to the defined storage position P2.

At the in 1 and 2 In the case shown, only two workpieces 62, 64 are recorded simultaneously in the transfer step and the press 12 is transferred. Accordingly, only a single first workpiece 62 has to be corrected in its position relative to a single second workpiece 64 . However, the present invention is not limited to this. It is also possible to correct the position of a plurality of first workpieces 62 relative to one or more second workpieces 64 . The articulated robot 66 then grasps a plurality of first workpieces 62 and positions them relative to the second workpieces 64.

Claims (7)

Method for conveying and positioning workpieces (62, 64), in which the workpieces (62, 64) are conveyed on a continuous conveying device (60) in a throughput direction (A), with at least one first workpiece (62) being moved relative to at least one second workpiece (64) is positioned, which maintains its position on the continuous conveyor (60), such that the at least one first workpiece (62) and the at least one second workpiece (64) have a defined orientation relative to one another on the continuous conveyor ( 60), and in a subsequent transfer step, the at least one first workpiece (62) and the at least one second workpiece (64) are simultaneously picked up by a transfer device (40) from a pick-up position (P1) in their defined orientation by the continuous conveyor (60). and transferred to a defined storage position (P2). procedure according to claim 1 , characterized in that before the position correction step actual positions of the at least one first workpiece (62) and the at least one second workpiece (64) on the continuous conveyor (60) are detected optically. procedure according to claim 2 , characterized in that from the detected actual positions target positions of the at least one first workpiece (62) and the at least one second workpiece (64) are determined, resulting in a common defined alignment. procedure according to claim 3 , characterized in that on the basis of the detected actual positions, the at least one first workpiece (62) is determined, which is positioned relative to the at least one second workpiece (64) in the position correction step. Method according to one of the preceding claims, characterized in that the transfer device (40) corrects the common spatial orientation of the at least one first workpiece (62) and the at least one second workpiece (64) in the transfer step. Device for conveying and positioning workpieces (62, 64), comprising: a continuous conveyor device (60) for conveying workpieces (62, 64) in a throughput direction (A), a positioning device (66) which is arranged on the continuous conveyor device (60) and means for positioning at least one first workpiece (62) relative to at least a second workpiece (64), an optical detection device (72) for the optical detection of actual positions of the at least one first workpiece (62) and the at least one second workpiece (64) on the continuous conveyor device and for the output of data in accordance with the detected actual positions, a control device, which is set up to control the positioning device (66) on the basis of the data corresponding to the detected actual positions, such that the positioning device (66) moves the at least one first workpiece (62) relative to the at least one second workpiece (64) so positioned on the continuous conveyor (60) that the at least s a first workpiece (62) and the at least one second workpiece (64) together assume a defined orientation relative to one another, and a transfer device (40) which is used to simultaneously receive the at least one first workpiece (62) and the at least one second workpiece ( 64) from a pick-up position (P1) on the continuous conveyor (60) in its defined alignment and for transferring the same into a defined deposit position (P2). Device according to one of the preceding claims, characterized in that the transfer device (40) is set up to correct the spatial orientation of the at least one first workpiece (62) and the at least one second workpiece (64) in the picked up state.

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