AT520649B1 - Method with a production device for forming sheet metal - Google Patents

Abstract

The invention relates to a method for producing a component by forming a workpiece (5) from sheet metal with a production device (1) with bending tools (6, 7) attached to press beams (2, 3) and with a control device (10) having a production program ( 14) for semi-automatic operation of the production device (1), wherein at least two production steps (F1, F2) are carried out, each with a bending deformation, and wherein a manufacturing step (F1, F2) comprises: positioning stops (8, 9) for aligning the workpiece (5); Inserting the workpiece (5) into the processing area (16) by an operator; Performing the bending deformation; Moving apart of the press beams (2, 3) and removal of the workpiece (5) by the operator. After a first production step (F1), the execution of a subsequent, second manufacturing step (F2) of the production program (14) is started by the processing area (16) being detected by a camera (17, 18) and the position by an image recognition program (15) and alignment of the workpiece (5) is determined and, based on the position of the workpiece (5) determined by the image recognition program (15), the production program (14) starts the subsequent second production step (F2).

Description

Patent Office

Description: The invention relates to a method for operating a production device for forming workpieces from sheet metal in accordance with the features of the preamble of claim 1.

Manufacturing facilities for forming workpieces from sheet metal, also referred to as bending machines for die bending or swivel bending or as press brakes, have two parallel press beams on which bending tools are arranged. The press beams are usually equipped with several bending tools arranged in pairs. A workpiece positioned between these bending tools is shaped by guiding them against one another or pressing them against one another, an edge being produced in the workpiece. Corresponding bending tools - lower tool and upper tool - are also called dies and patrices.

For the production of complex components, several bending operations are carried out in succession on the same workpiece in a suitable sequence of manufacturing steps. Each and every one of such manufacturing steps for the execution of bending forming comprises several phases or individual measures. These include: bringing the stops into the starting position; Place the workpiece on the lower tool and place it on the stops; Press the upper tool against the workpiece and lower tool; Raise upper tool; Remove workpiece. To carry out a further production step, the stops are repositioned and the phases mentioned are repeated accordingly.

In the prior art it is also known to provide automated or semi-automated control of the operation of these machines in such manufacturing facilities or bending machines. For this purpose, it is customary, for example, for an operator to insert the workpiece into the machine and bring it to bear against the stops, whereupon the press bars are moved together after actuation of a foot switch and the workpiece is thus reshaped. After pressing the foot switch again, the next manufacturing step is initiated. The necessary adjustments and repositioning of the stops or support brackets is carried out automatically on the basis of a program stored in the control. Only the triggering of the stroke or the movement of the press bars and the switching to the next production step are carried out by the operator on their initiative.

On the other hand, there are also known solutions for monitoring the working area of press brakes, in which light barriers or similar sensor arrangements are provided, but mainly prevent injuries to operators during the automatic or semi-automatic position changes of machine parts or bending tools due to the collisions between machine components should be.

In the known workpiece processing machines, increased attention and concentration of the operating personnel is still required, at the same time to remove the workpiece from the machine after a completed manufacturing step, to bring it into a new orientation and to reinsert it into the machine and to produce the manufacturing program in a timely manner to switch to the next manufacturing step.

The object of the present invention is to provide an improved method for operating a manufacturing device or a workpiece processing machine, by which the operation is simplified and with which a higher level of safety can be achieved.

The object is achieved by a method for producing a component, by reshaping a workpiece from sheet metal and the use of a manufacturing device such as a press brake with two parallel aligned press beams, with bending tools fastened to the press beams and with a control device with a production program for the semi-automatic operation of the production facility, at least two production steps being carried out, each with a bending operation. Everyone

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The patent office for these manufacturing steps includes the measures and phases:

Positioning stops for aligning the workpiece in a machining area;

Placing the workpiece in the machining area by placing it on a lower tool and placing or placing the workpiece on the stops by an operator;

Carrying out the bending by pressing or pressing an upper tool against the workpiece and the lower tool by moving the press beam against each other;

Moving the press bars apart;

Removal of the workpiece from the lower tool by the operator.

In this case, after a first production step, the execution of a subsequent, second production step of the production program is started, the processing area being detected by at least one camera and the position and orientation of the workpiece being determined from the images obtained by the camera using an image recognition program, and based on the position determined by the image recognition program and the orientation of the workpiece, through which the subsequent, second manufacturing step is started by the manufacturing program.

The procedure is also advantageous, wherein the positioning of the stops by the control device is carried out automatically on the basis of instructions in the manufacturing program. This has the advantage that manipulation times for re-setting the stops can be optimized.

It is also advantageous that the bending device is automatically started by the control device when it has been determined by the image recognition program that the workpiece has been inserted into the processing area and brought to bear against the stops. This has the particular advantage of relieving the burden on the operator, since this can now concentrate entirely on inserting and aligning the workpiece to be machined and, for example, it is very unlikely that the workpiece will slip while a switch is otherwise required to start the movement of the press beam.

Also advantageous is the procedure in which the execution of the bending deformation is automatically stopped by the control device when it has been determined by the image recognition program that the desired deformation state of the workpiece has been reached and that the control device then carries out the spreading of the press beams.

The procedure in which the second manufacturing step following the first manufacturing step is only started when it has been determined by the image recognition program that the workpiece has been completely removed from the observation area has the advantage of particularly high operational reliability.

By the measure, wherein the positioning of the stops in the second manufacturing step following the first manufacturing step is already started when it has been determined by the image recognition program that the workpiece is a greater distance from the bending tools than a value of a predetermined minimum distance, which has been defined in the production program has the advantage of a corresponding time saving and thus enables a higher productivity as a whole.

With the further measure that during the positioning of the stops they are only moved so quickly by the control device that the predetermined minimum distance is not fallen below, a sufficient safety distance can be maintained at all times.

The procedure is also advantageous, with first in a third manufacturing step

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Patent placement of the workpiece into the machining area by the operator and only then the stops are positioned by the control device, the bending forming being started by the control device when it has been determined by the image recognition program that the positioning of the stops has been completed.

For a better understanding of the invention, this will be explained in more detail with reference to the following figures.

[0023] Each shows in a highly simplified, schematic representation:

Figure 1 Figure 2 Figure 3 a bending press as an embodiment of a manufacturing facility; a cross section of the bending press of FIG. 1; a timing diagram of a manufacturing program for manufacturing a component on the bending press; Fig. 4 a detail of the bending press with the workpiece in a fourth manufacturing step of the manufacturing program; Fig. 5 Figure 6 Figure 7 Fig. 8 a timing diagram of a second mode of operation of the bending press; a timing diagram of a third mode of operation of the bending press; a timing diagram of a fourth mode of operation of the bending press; a detail of the bending press with the workpiece in a manufacturing step of the operation according to FIG. 7.

As an introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numerals or the same component names, the disclosures contained in the entire description being able to be applied analogously to the same parts with the same reference numerals or the same component names. The location information selected in the description, e.g. above, below, to the side, etc., referring to the figure described and illustrated immediately, and if the position is changed, these are to be applied accordingly to the new position.

1 shows a bending press 1 as an exemplary embodiment of a manufacturing device or a workpiece processing machine. The bending press 1 has, in a known manner, a lower press beam 2 and an upper press beam 3. The two press beams 2, 3 are held by a machine frame 4, the lower press beam 2 being fixed, i.e. is fixedly attached to the machine frame 4. The lower, fixed press beam 2 is therefore often referred to as a table beam. The upper press beam 3, on the other hand, is adjustable on the machine frame 4 in the vertical direction (Z direction). With the aid of a suitable motor drive, for example with the aid of hydraulic cylinders (not shown), the upper press beam 3 can be lowered onto the lower press beam 2. To carry out a bending deformation on a workpiece 5, a pair of lower bending tools 6 (a die) and an upper bending tool 7 (a male) are attached to the two press beams 2, 3 in pairs. A bending deformation on the workpiece 5 is then carried out by moving the two press beams 2, 3 against one another, the upper bending tool 7 (short: “upper tool”) being pressed against the workpiece 5 and the lower bending tool 6 (short: “lower tool”), until the desired degree of deformation of the workpiece 5 is reached.

In addition to the bending tools 6, 7 which actually effect the bending, and which act on the workpiece 5 through the relative adjustment of the press beams 2, 3, the bending press 1 also comprises one or more stops 8, 9, on which edges or sides of the workpiece 5 can be created and thus aligned. The stops 8, 9 are usually also referred to as “back stops, since from the point of view of an operator standing in front of the bending press 1, these are arranged behind the press beams 2, 3. After appropriate positioning of the stops 8, 9 relative to the bending tools 6, 7, an operator can bend or bend the workpiece 5 very easily and nevertheless

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Patent office can be manufactured with great accuracy.

To operate the bending press 1, it is designed with a control device 10 and with an operating terminal 11. The operating states of the bending press 1 can be displayed to an operator on a screen 12 of the operator terminal 11 and the operator can thus prepare manufacturing steps to be carried out with the bending press 1 via an input device 13. This preparation of a new manufacturing step can consist, for example, of repositioning the stops 8, 9. For this purpose, the stops 8, 9 are motor-driven adjustable and the operator can effect the repositioning of the stops 8, 9, for example by directly entering the new coordinates.

Usually, the machine settings required for the individual production steps are stored in a production program 14 in the control device 10. The operator can call up the production program 14 on the operating terminal 11 and display it. The corresponding production steps can be selected and the setting of the new operating state of the bending press 1 can be started. After inserting the workpiece 5, that is to say placing the workpiece 5 on the lower tool 6 and placing or placing it on the abutment surfaces of the stops 8, 9, the bending deformation can then be started by moving the press beams 2, 3 against one another. In conventional bending presses, the operator has a separate switch, for example formed by a foot switch. By actuating the switch, the up and down movement of the upper press beam 3 can be started.

In the bending press 1 according to this embodiment, the control device 10 is also formed with an image recognition program 15. The image recognition program 15 is suitable for analyzing images recorded by a processing area 16 in the vicinity of the bending tools 6, 7 or the workpiece 5 and for determining the current processing status of the workpiece 5 or the current phase of the manufacturing step to be carried out with the aid of automatic pattern recognition. At least one first camera 17 is arranged on the bending press 1 in order to capture the processing area 16. When the bending press 1 is in operation, images of the processing area 16 recorded by the camera 17 are analyzed by the image recognition program 15 and the operating states recognized by the image recognition program 15 are used in the phases of the production steps to control the sequence of the production program 14 itself.

Thus, when the workpiece 5 is inserted by the operator into the machining area 16, the image recognition program 15 can be used to automatically determine whether the initially undeformed workpiece 5 has been brought into contact with the stops 8, 9 and thus its initial length has reached. If this has been determined by the image recognition program 15, the start of the next phase in the production program 14, namely the bending forming by moving the press beams against one another, can be initiated automatically. Finally, by evaluating the images of the camera 17, the image recognition program 15 can also determine whether the desired deformation state of the workpiece 5 has been reached, whereupon - again automatically - the next phase in the manufacturing step of the manufacturing program 14, namely the spreading of the press bars , is initiated. The operator does not need to operate a switch. This switching to the next phase of a production step, and also the switching from a first production step to the next production step of the production program 14, takes place automatically by the control device 10, the respective analysis results from the image recognition program 15 serving as a basis for this.

FIG. 2 shows a cross section of the bending press 1 according to FIG. 1.

In addition to the first camera 17 which is arranged in front of the upper press beam 3 (to the right of the press beam 3 as shown), a second camera 18 (to the left of the press beam 3) is also arranged behind the upper press beam 3 in this exemplary embodiment. An optical axis 19 of the camera 17 and an optical axis 20 of the camera 18

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Patent Office are directed obliquely from above onto the processing area 16 or the workpiece 5 in the processing area 16. Each of the two stops 8, 9 is fastened to a stop device 21 and can be adjusted with the aid thereof in the three spatial directions X, Y, Z and thus repositioned. For this purpose, the stop device 21 has guideways 22 which are directed in the X, Y and Z directions and thus interacting servomotors 23.

The illustration in FIG. 2 shows two different points in time of two successive phases of a first production step F1 of the production of a component from the workpiece 5. The position of the undeformed workpiece 5 - shown in solid lines - corresponds to the end of the phase "inserting the workpiece 5 into the machining area 16 and placing it against the stops 8, 9". The position of the workpiece 5 in the bent state - shown in dashed lines - corresponds to the end of the bending deformation or the end of the phase “press upper tool 7 against workpiece 5 and lower tool 6”.

In total, at least five measures or phases can be distinguished in the first production step F1, as in every further production step. These phases are:

P1: positioning the stops 8, 9 for aligning the workpiece 5 in the machining area 16;

11: inserting the workpiece 5 into the machining area 16 by placing it on the lower tool 6 and placing or placing the workpiece 5 on the stops 8, 9;

B1: Performing the bending deformation by pressing the upper tool 7 against the workpiece 5 and the lower tool 6 by moving the press beams 2, 3;

01: moving the press bars 2, 3;

R1: Removing the workpiece 5 from the lower tool 6.

The monitoring of the observation area 16 with the cameras 17, 18 and the evaluation of the images by the image recognition program 15 now enable the completion of phase 11, that is, the phase of inserting the workpiece 5 by the image recognition program 15, to be determined automatically and the following phase B1, that is to say the execution of the bending deformation, is also started automatically by the control device 10. As a result, the end of phase B1 is also determined by the image recognition program 15 and phase 01 is started automatically by the control device 10. Finally, the image recognition program 15 also determines whether the workpiece 5 has been removed from the lower tool 6, whereupon the control device 10 can start the next, second production step F2 of the production program 14 (FIG. 3). This second production step F2 also begins again with positioning the stops 8, 9 in a phase P2, whereupon the further phases I2, B2, O2 and R2 are carried out in an analogous manner with the participation of the image recognition program 15.

3 shows a schematic representation of the time course of two or more successive production steps F1, F2, etc. of a production program 14 for producing a complex component from the workpiece 5. Each of these production steps F1, F2 comprises the phases :

P: positioning of the stops 8, 9;

I: insertion of the workpiece 5;

B: performing the bending deformation;

[0053] O: Moving the press beams apart and R: Removing the workpiece 5.

By equipping the bending press 1 with at least one camera 17, 18 and the

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Patent Office

Using the image recognition program 15 in the control device 10 ensures that a further, separate switch and the actuation of the switch by the operator can be omitted in the course of the manufacturing steps F1, F2 or the phases P, I, B, O and R of individual manufacturing steps , The operator can restrict himself to inserting the workpiece 5 into the machining area 16 in phase 11 and bringing it to bear on the lower tool 6 and the stops 8, 9. The image recognition program 15 automatically determines whether the workpiece 5 is in the correct position and thereupon the control device 10 automatically initiates phase B1 by starting the bending deformation. The start of the bending deformation at the beginning of phase B1 is thus only indirectly initiated by the operator by inserting the workpiece 5 into the machining area 16 and bringing it fully into contact with the lower bending tool 6 and the stops 8, 9.

However, the time of the start of this phase B1 also depends entirely on the movements of the operator with which he inserts the workpiece 5 into the machining area 16. This point in time is just the end of phase 11, at which the image recognition program 15 determines that the workpiece 5 has been brought to bear entirely against the lower bending tool 6 and the stops 8, 9. The same applies to the removal of the workpiece 5 by the operator in phase R1. Like the duration of phase 11, the duration and end of phase R1 depend on the movements of the operator. This indeterminacy of the duration of phases 11, R1 and also phases I2 and R2 of the subsequent manufacturing step F2 is therefore shown in FIG. 3 by a jagged course of the lateral lines of these phases.

By using the image recognition program 15 in the control of the production program 14 delays, such as would occur in the operation of switches that would otherwise have to be carried out by an operator, for switching between the phases of the production steps F1, F2, can be completely eliminated. The above statements regarding the first production step F1, with the phases P1, 11, B1, 01 and R1, apply analogously to the second production step F2, with the corresponding phases P2, I2, B2, 02 and R2, and if necessary also for other subsequent manufacturing steps F3, F4, etc.

4 shows the workpiece 5 in the machining area 16 of the bending press 1 during the fourth manufacturing step F4. The shape of the workpiece 5 and the current position of the bending tools 6, 7 corresponds - according to the designation used above - to the end of phase B4, i.e. on the workpiece 5, the fourth bending is just finished. At the end of the fourth manufacturing step F4, phases 04 and R4 have to be carried out. A production program 14 with at least four production steps F1, F2, F3 and F4 is illustrated by way of example in FIG. 4.

According to the embodiment of the method as shown in FIG. 3, it is provided that the second manufacturing step F2 or its first phase P2 of repositioning the stops 8, 9 is only started when the workpiece 5 is in the phase R1 has been completely moved out of the processing area 16. That Only when the image recognition program 15 has determined that the workpiece 5 has been completely removed from the lower tool 6 or from the machining area 16, the control device 10 switches the production program 14 to phase P2.

5 shows a schematic temporal course of a second exemplary embodiment of the method for operating the bending press 1. It is provided that the phase P2 of repositioning the stops 8, 9 of the second manufacturing step F2 before the end of the phase R1 the removal of the workpiece 5 from the machining area 16 is started. For this purpose, a value of a minimum distance between the workpiece 5 and the stops 8, 9 in the X direction is defined in the production program 14. The next phase P2, i.e. the repositioning of the stops 8, 9 can thus take place earlier, and in particular if the image recognition program 15 determines that the workpiece

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Patent office from the bending tools 6, 7 has reached a greater distance than the value of the predetermined minimum distance. 5, this start of phase P2, triggered by monitoring the distance, is graphically represented by an overlap of phases R1 and P2 or by an overlap of phases R2 and P3.

6 shows a timing diagram of a third exemplary embodiment of the operation of the bending press 1. In the production program 14, a value of a minimum distance between the workpiece 5 and the stops 8, 9 is in turn specified and the monitoring is carried out by evaluating the images of the Cameras 17, 18 with the aid of the image recognition program 15. In this procedure, the distance between the workpiece 5 and the stops 8, 9 is continuously monitored over time, so that the movement or the speed of the movement of the stops 8, 9 to that of the workpiece 5 - quasi in real time - can be coupled. The movement of the stops 8, 9 also starts here only when the distance exceeds the value of the predetermined minimum distance. However, it is also also provided that the speed of the movement of the stops 8, 9 is only so great that the predetermined minimum distance is not undershot again. The movement of the stops 8, 9 takes place at a safety distance from the workpiece 5 moved by the operator. Accordingly, the duration of the repositioning of the stops 8, 9 in phase P2, as well as phase R1, can depend on the movements of the operator ( indicated by a jagged course of the lateral lines of phases R1 and P2).

7 and 8, a fourth embodiment of the operation of the bending press 1 will be described. With this procedure, the production program 14 contains a second production step F2 with a so-called “Z-bend” of the workpiece 5. In order to carry out a subsequent, third production step F3, it may be necessary for the workpiece 5 to first move to the lower one Bending tool 6 is to be placed (corresponds to phase I3) and the stops 8, 9 can only then be moved to the lower bending tool 6 and the workpiece 5 (corresponds to phase P3). The start of the subsequent bending forming in phase B3 is triggered in this case by the control device 10 when it has been determined by the image recognition program 15 that the repositioning of the stops 8, 9 and thus the phase P3 has been completed.

Combinations of the above modes of operation with the use of stops 8, 9 monitored by sensor elements can also be provided as further embodiment variants of the mode of operation of the bending press 1. The stops 8, 9 are for example equipped with force measuring elements or contact switches. Continuous monitoring of the measurement signals of such sensor elements by the control device 10 makes it possible to automatically initiate a countermeasure in the event of a collision with incorrectly positioned machine parts, but especially in the event of a collision or pinching of a body part.

For the sake of order, it should finally be pointed out that, for a better understanding of the structure, elements have sometimes been shown to scale and / or enlarged and / or reduced.

Claims (8)

Patent Office Claims 1. Method for producing a component by forming a workpiece (5) from sheet metal with a production device (1) with two parallel pressing bars (2, 3), with bending tools (6, 7) attached to the pressing bars (2, 3) and with a control device (10) with a production program (14) for the semi-automatic operation of the production device (1), wherein at least two production steps (F1, F2) are each carried out with a bending deformation, and wherein a production step (F1, F2) comprises the measures : - Positioning stops (8, 9) for aligning the workpiece (5) in a machining area (16); - Inserting the workpiece (5) into the machining area (16) by placing it on a lower tool (6) and placing or placing the workpiece (5) on the stops (8, 9) by an operator; - Performing the bending deformation by pressing an upper tool (7) against the workpiece (5) and the lower tool (6) by moving the pressing beams (2, 3) against each other; - Moving the press bars (2, 3) apart; - The operator removes the workpiece (5) from the lower tool (6); wherein after a first production step (F1) the execution of a subsequent, second production step (F2) of the production program (14) is started, characterized in that the processing area (16) is recorded by at least one camera (17, 18) and by an image recognition program (15) the position and orientation of the workpiece (5) is determined and, based on the position and orientation of the workpiece (5) determined by the image recognition program (15), the subsequent, second production step (F2) is started by the production program (14) becomes. 2. The method according to claim 1, characterized in that the positioning of the stops (8, 9) by the control device (10) is carried out automatically on the basis of instructions from the production program (14). 3. The method according to claim 1, characterized in that the execution of the bending deformation is started automatically by the control device (10) when it has been determined by the image recognition program (15) that the workpiece (5) is inserted into the processing area (16) and has been brought to bear on the stops (8, 9). 4. The method according to claim 1, characterized in that the execution of the bending deformation by the control device (10) is automatically stopped when it has been determined by the image recognition program (15) that the desired deformation state of the workpiece (5) has been reached, and that the control device (10) then moves the press bars (2, 3) apart. 5. The method according to claim 1, characterized in that the second manufacturing step (F2) following the first manufacturing step (F1) is only started when it has been determined by the image recognition program (15) that the workpiece (5) is completely out of the Processing area (16) has been removed. 6. The method according to claim 1, characterized in that the positioning of the stops (8, 9) in the second manufacturing step (F2) following the first manufacturing step (F1) is already started when the image recognition program (15) has determined that the workpiece (5) from the bending tools (6, 7) has a greater distance than a value of a predetermined minimum distance, the value of the minimum distance being determined in the production program (14). 9.15 AT 520 649 B1 2019-06-15 Austrian Patent Office 7. The method according to claim 6, characterized in that during the positioning of the stops (8, 9), these are only moved so quickly by the control device (10) that the predetermined minimum distance is not undershot. 8. The method according to claim 1, characterized in that in a third manufacturing step (F3) the workpiece (5) is first inserted into the machining area (16) by the operator and only then the stops (8, 9) by the control device ( 10) can be positioned, the bending deformation being started by the control device (10) when it has been determined by the image recognition program (15) that the positioning of the stops (8, 9) has been completed.