Device and method for releasing a workpiece with a cut edge

Abstract

A device (10) for releasing a workpiece (12) with a cut edge (14), produced by a first machine tool (20), for a further process by a second machine tool (36). The device has a detection means (16), for example a camera (22), and a control means (18). The detection means (16) is designed to detect a formation of the cut edge (14) of the workpiece (12). The control means (18) is designed to release the workpiece (12) for the process (36) based on the detected formation of the cut edge (14) and in the event of a low-level machining defect. Furthermore, the control means (18) is designed not to release the workpiece (12) based on the detected formation of the cut edge (14) and in the event of a high-level machining defect, and the workpiece (12) can be transferred in this case to a third machine tool (38) in order to remedy the machining defect.

Description

[0001] DEVICE AND METHOD FOR RELEASING A WORKPIECE WITH A CUT EDGE

[0002] Description

[0003] The invention relates to a device and a method for operating a device.

[0004] Machine tools are often used to cut a workpiece. After the workpiece has been cut, the workpiece has a cutting edge created by the machine tool. The formation of the cutting edge depends on at least one cutting parameter of the machine tool with which the machine tool created the cutting edge. If an unsuitable cutting parameter is used to cut the workpiece, the cutting edge may have a machining defect, for example in the form of a burr. If the cutting edge has a machining defect and the workpiece goes through a processing process, such as painting or bending, the machining defect often impairs the quality of the processing. For example, the machining defect may result in not all areas of the workpiece being completely painted or in the workpiece being damaged during bending.

[0005] DE 10 2021 200 598 A1 discloses a device for analyzing a cutting edge of a workpiece. The workpiece is held in a workpiece holder, with the cutting edge illuminated at an acute angle in the cutting direction or counter to the cutting direction. The roughness and the cutting edge bevel can be captured with a camera under such illumination. The camera creates a set of cutting edge images to characterize the cutting edge.

[0006] DE 10 2019 209 088 A1 discloses a method for evaluating a laser-cut edge of a workpiece. The method comprises the steps of: A) acquiring image data of the laser-cut edge and its surroundings, B) segmenting the image data and identifying a segment of interest in the image data, wherein the segment of interest comprises image data of the laser-cut edge, C) performing image quality detection for the segment of interest, and D) generating an output for a user based on the image quality detection.

[0007] The object of the invention is to provide a

[0008] The invention is based on a device which enables the assurance of high quality in a processing process and / or the increase of the degree of automation, particularly in flow production. Furthermore, it is an object of the present invention to provide a method for operating the device.

[0009] The invention solves this problem by providing a device having the features of claim 1 and a method having the features of claim 13. Advantageous developments and / or refinements of the invention are described in the dependent claims.

[0010] A device according to the invention is designed to release a workpiece having a cutting edge produced by a machine tool for a processing process. The device has a detection device and a control device. The detection device is designed to detect a formation of the cutting edge. The control device is designed to release or not release the workpiece for the processing process based on the detected formation of the cutting edge.

[0011] Advantageously, by releasing the workpiece for processing by means of the control device, the degree of automation, particularly in flow production, can be increased. Advantageously, by releasing the workpiece for processing, it is ensured that only a released workpiece passes through the processing, thereby ensuring a high quality of the processing. The machine tool can be a cutting machine, in particular a laser cutting machine or a laser cutting system.

[0012] The workpiece may be a sheet metal. In particular, the width and / or length of the workpiece may be more than five times, in particular ten times, the thickness of the workpiece.

[0013] The control device can be a computer-implemented control device. The control device can comprise, in particular, a computing device, a microcontroller, a computer, a production control system, a manufacturing execution system, a programmable logic controller, and / or an IPC-based controller.

[0014] The cutting edge may have a machining error. Detecting the formation of the cutting edge may include detecting the machining error. The release or non-release of the workpiece may be based on a frequency and / or severity of the machining error. For example, the workpiece may not be released due to a severe machining error. For example, the workpiece may be released due to a minor machining error.

[0015] The machining defect can be a burr, a melt that has folded over, a slag build-up, a splash on the upper side and / or on the lower side of the workpiece, a wavy cut start, a groove lag, a roughening, a pit, a spontaneous combustion, a slagging, a cut surface discoloration, a corner discoloration and / or a cut end discoloration. Additionally or alternatively, the machining defect can be a deviation of a position and / or a position of the cutting edge from a specified target position and / or a specified target position of the

[0016] Cutting edge. Additionally or alternatively, the machining error can be a deviation from a specified target symmetry of the workpiece.

[0017] The detected formation of the cutting edge can deviate from a predefined target formation of the cutting edge. The target formation of the cutting edge can have a rectangular cross-section. The deviation can occur due to a machining error. The control device can be designed to evaluate the deviation from the target formation of the cutting edge and to compare it with a predefined limit evaluation. The control device can be designed to release the workpiece if the evaluation of the deviation is equal to or better than the predefined limit evaluation, and not to release the workpiece if the evaluation of the deviation is worse than the predefined limit evaluation.

[0018] The deviation assessment may be poor if the cutting edge exhibits numerous machining defects and / or severe machining defects. The deviation assessment may be good if the cutting edge exhibits few machining defects and / or mild machining defects.

[0019] The limit evaluation can be an evaluation of a deviation from the desired cutting edge configuration at which a high processing quality can be achieved and / or at which the processing can be carried out. A robot can feed the workpiece to the device to release the workpiece for the processing process.

[0020] If the workpiece is released, the workpiece can proceed through the processing process. If the workpiece is not released, the workpiece cannot proceed through the processing process.

[0021] In a further development of the device, the processing process comprises deburring the cut edge, welding the workpiece, bending the workpiece, painting the workpiece, and / or punching the workpiece. The processing process can be deburring the cut edge, welding the workpiece, bending the workpiece, painting the workpiece, and / or punching the workpiece.

[0022] For example, the processing process may be welding the workpiece, whereby the release of the workpiece ensures that the edges to be welded lie cleanly against each other and do not have any burrs that cause a welding defect.

[0023] For example, the processing process may be bending the workpiece, where releasing the workpiece ensures that the workpiece to be bent does not have a burr that causes a bending defect.

[0024] For example, the processing process may be painting the workpiece, whereby the release of the workpiece ensures that the workpiece to be painted does not have a burr that causes a painting defect.

[0025] In a further development of the device, the control device is designed to determine a parameter of the processing process based on the detected formation of the cutting edge. Advantageously, the determined parameter enables the workpiece to undergo the processing process, in particular even though the workpiece has the processing error and / or the deviation. For example, a value of the parameter of the processing process can be determined based on an expression of the detected formation of the cutting edge. The parameter of the processing process can be determined in such a way that the formation of the cutting edge is changed by the processing process. For example, the processing error and / or the deviation can be reduced by means of the processing process.

[0026] In a further development of the device, the parameter of the processing process has a deburring parameter, a welding parameter, a bending parameter, a painting parameter and / or a punching parameter. The deburring parameter can have a rotational speed of a tool for deburring the workpiece. The welding parameter can have a welding speed for welding the workpiece. The bending parameter can have a bending force for bending the workpiece. The painting parameter can have a painting direction for painting the workpiece. The punching parameter can have a punching force for punching the workpiece. In a further development of the device, the control device is designed to determine a material parameter of the workpiece and / or an orientation of the workpiece, in particular based on the detected formation of the cutting edge.The control device can be designed to release or not release the workpiece for the processing process based on the determined material parameter and / or the determined orientation of the workpiece. The material parameter can be a material type of the workpiece and / or a thickness of the workpiece. The orientation of the workpiece can be a layer and / or a position of the workpiece. In particular, the orientation of the workpiece can be an orientation of a top side of the workpiece and / or an orientation of a bottom side of the workpiece.

[0027] In a further development of the device, the control device is designed to determine, based on the detected configuration of the cutting edge, whether turning the workpiece is necessary for the processing. For example, the determination of whether turning the workpiece is necessary can be based on detection of a top side and / or a bottom side of the workpiece.

[0028] Turning the workpiece may be referred to as turning the workpiece over. Turning the workpiece may comprise rotating the workpiece. Turning the workpiece may be rotating the workpiece 180°. The controller may be configured to initiate turning the workpiece. For example, turning the workpiece may be required when the processing process is deburring the cut edge and a burr of the cut edge to be removed faces away from a deburrer. After turning the workpiece, the deburrer may remove the burr. For example, turning the workpiece may be required when the processing process is painting one side of the workpiece and a burr of the cut edge faces a painting nozzle. After turning the workpiece, the painting nozzle may paint the side of the workpiece without being affected by the burr.

[0029] The control device can be configured to initiate, after the workpiece has been turned, feeding the turned workpiece to the detection device for detecting the formation of the cutting edge for the purpose of releasing or not releasing the turned workpiece. The control device can be configured to not release a turned workpiece if the control device determines that the turned workpiece has been turned based on the detected formation of the cutting edge of the turned workpiece.

[0030] In a further development of the device, the control device is designed to determine a processing process prior to the processing process from a set of predetermined upstream processing processes based on the detected formation of the cutting edge. The upstream processing process can be necessary for the processing process to run smoothly. The upstream processing process can be a repetition of the last processing process through which the workpiece has undergone. After passing through the upstream processing process, the workpiece can be fed back to the device for the purpose of releasing it or not releasing it.

[0031] In a further development of the device, the set of predetermined upstream processing steps includes at least deburring the cut edge and / or grinding the cut edge. For example, the processing step can be painting, wherein the device, based on the detected shape of the cut edge, detects a burr to be removed before painting and determines deburring of the cut edge as a upstream processing step.

[0032] In a further development of the device, the control device is designed to optimize at least one cutting parameter of the machine tool based on the detected formation of the cutting edge. The control device can be designed to optimize the cutting parameter in such a way that a deviation of a cutting edge of another workpiece, created by the machine tool and using the optimized cutting parameter, from the desired formation of the cutting edge is minimized. The control device can be designed to optimize the cutting parameter in such a way that the cutting edge does not exhibit any machining errors.

[0033] The cutting parameter can be a focus diameter, a laser power, a nozzle-to-focus distance, a nozzle-to-workpiece distance, a feed rate, a gas pressure, a nozzle diameter, or a gas type. The control device can be configured to optimize several cutting parameters of the machine tool based on the detected cutting edge configuration, in particular simultaneously.

[0034] The detection device can be designed to detect a formation of a cutting edge that was created with the optimized cutting parameters, wherein the control device can be designed to optimize the optimized cutting parameters of the machine tool based on the detected formation of the cutting edge that was created with the optimized cutting parameters.

[0035] In a further development of the device, the detection device has an optical sensor, a tactile sensor and / or an acoustic sensor for detecting the formation of the cutting edge. The optical sensor can have, in particular be, a camera, in particular a digital camera, for taking a photo of the cutting edge and / or a light section sensor, in particular for detecting a height profile of the cutting edge. The tactile sensor can have, in particular be, a probe for scanning the cutting edge. The acoustic sensor can have, in particular be, an ultrasonic sensor.

[0036] In a further development of the device, the device has a manipulator for gripping, moving and / or manipulating the workpiece. The control device is designed to control the manipulator, in particular as a function of the detected formation of the cutting edge. For example, before the workpiece is released, the control device can control the manipulator in such a way that the workpiece is gripped by means of the manipulator and moved to the detection device for detecting the formation of the cutting edge. For example, after the workpiece is released, the control device can control the manipulator in such a way that the workpiece is clamped by means of the manipulator in a machine tool for carrying out the processing.

[0037] In a further development of the device, the detection device is arranged on the manipulator. The detection device can be designed to detect the formation of the cutting edge when the workpiece is gripped by the manipulator.

[0038] A method according to the invention for operating a device as described above comprises the steps of : a ) detecting the formation of the cutting edge and b ) releasing or not releasing the workpiece for the processing process based on the detected formation of the cutting edge .

[0039] Further advantages and advantageous embodiments of the invention can be found in the following drawings, their description, and the patent claims. All features disclosed in the drawings, their description, and the patent claims can be essential to the invention both individually and in any combination. They show:

[0040] Fig. 1 is a schematic view of a device for

[0041] Releasing a workpiece, Fig. 2 is a schematic view of the workpiece of Fig. 1,

[0042] Fig. 3 is a schematic view of another workpiece,

[0043] Fig. 4 is a schematic view of a layout of a flow production with the device of Fig. 1,

[0044] Fig. 5 is a schematic flow diagram of a method for operating the device of Fig. 1, and

[0045] Fig. 6 is a further schematic flow diagram of the method of Fig. 5.

[0046] Fig. 1 shows a device 10 for releasing a workpiece 12 with a cutting edge 14 created by a machine tool for a processing process.

[0047] The device 10 has a manipulator 26 for gripping, moving, and manipulating the workpiece 12. The manipulator 26 is a robot with a gripper 28 for gripping the workpiece 12. Fig. 1 shows that the workpiece 12 is gripped by the gripper 28.

[0048] The device 10 has a control device 18. The control device 18 is a computer-implemented control device in the form of a computer. The control device 18 is designed to control the manipulator 26. The control device 10 can control the manipulator 26 such that the workpiece 12 is gripped, moved, or released by the gripper 28. The device 10 has a detection device 16 for detecting the formation of the cutting edge 14. The detection device 16 has an optical sensor 22 in the form of a digital camera.

[0049] In an alternative embodiment, the detection device 16 may, in addition to or alternatively to the optical sensor 22, have a tactile sensor 24 and / or an acoustic sensor 25 for detecting the formation of the cutting edge 14.

[0050] The detection device 16 is arranged on the manipulator 26. The control device 18 has controlled the manipulator 26 such that the cutting edge 14 of the workpiece 12 faces the detection device 16. The detection device 16 is designed to detect the formation of the cutting edge 14 when the workpiece 12 is gripped with the manipulator 26. The detection device 16 creates a photograph of the cutting edge 14 of the workpiece 12 gripped with the manipulator 26.

[0051] Fig. 2 shows the workpiece 12 gripped by the manipulator 26. The workpiece 12 is a sheet metal. The cutting edge 14 was created with the machine tool in the form of a laser cutting machine. The cutting edge 14 has a machining defect. The machining defect is a burr 30 and a roughening 32.

[0052] Detecting the formation of the cutting edge 14 by means of the detection device 16 includes detecting the burr 30 and the roughening 32. The control device 18 is configured to release or not release the workpiece 12 for the processing process based on the formation of the cutting edge 14 detected by the detection device 16. The release or not release of the workpiece 12 occurs based on the characteristics of the burr 30 and the roughening 32.

[0053] In the example shown in Fig. 2, the burr 30 and the roughening 32 are so pronounced that the processing is not impaired by the presence of the burr 30 and the roughening 32.

[0054] The control device 18 is designed to determine an orientation of the workpiece 12 based on the detected configuration of the cutting edge 14. In the example shown, the workpiece 12 gripped by the manipulator 26 is oriented such that the cutting edge 10 extends orthogonally to a viewing direction of the camera 22. The processing process is not impaired by such an orientation of the workpiece 12.

[0055] The control device 18 releases the workpiece 12 for the processing process based on the detected formation of the cutting edge 14 and the determined orientation of the workpiece 12. Due to the release, the workpiece 12 can proceed through the processing process.

[0056] The control device 18 is designed to determine, based on the detected formation of the cut edge 14, whether turning the workpiece 12 is required for the processing process. In the example shown, the processing process is painting a side 34 of the workpiece 12 and painting the cut edge 14. Fig. 1 shows that the side 34 points downwards and the burr 30 points upwards as seen from a viewer in Fig. 1. Therefore, the control device 18 determines, based on the orientation of the burr 30, that turning the workpiece 12 is required for the processing process. Turning the workpiece 12 is rotating the workpiece 12 by 180°. The control device 10 controls the manipulator 26 such that the workpiece 12 is turned. After turning, the burr 30 points from a viewer in Fig. 1 downwards and page 34 upwards.

[0057] The control device 18 is designed to determine a painting parameter for the painting process based on the detected configuration of the cut edge 14. The painting parameter is a painting direction. The control device 18 determines the painting direction based on the roughening 32 such that, when the cut edge 14 is painted, an applied paint penetrates into the spaces between the roughening 32. This results in a continuous paint layer on the cut edge 14. Advantageously, the applied paint fills the spaces between the roughening 32, thereby reducing the severity of the roughening 32.

[0058] The control device 18 controls the manipulator 26 such that the workpiece 12 is clamped by means of the manipulator 26 into a machine tool in the form of a painting machine for carrying out the painting. Fig. 3 shows a variant of the workpiece 12 of Fig. 2, wherein identical and functionally equivalent elements are denoted by the same reference numerals, and in this respect, reference can be made to the above explanations regarding the exemplary embodiment of Fig. 2, so that essentially only the existing differences will be discussed.

[0059] The workpiece 12 of Fig. 3 has a burr 30 which is so pronounced that the processing cannot be carried out due to the presence of the burr 30. When the workpiece 12 of Fig. 3 is gripped by the manipulator 26, the formation of the cutting edge 14 is detected by the detection device 16. The control device 18 does not release the workpiece 12 for the processing process based on the detected formation of the cutting edge 14. Therefore, the workpiece 12 cannot undergo the processing process.

[0060] The control device 18 is designed to determine a processing process prior to the processing process from a set of predetermined upstream processing processes based on the detected formation of the cutting edge 14. The set of predetermined upstream processing processes comprises at least deburring the cutting edge 14 and / or grinding the cutting edge 14. In the example shown in Fig. 3, the determined upstream processing process is deburring the cutting edge 14.

[0061] The control device 18 is designed to control at least one

[0062] The control device 18 optimizes the cutting parameters of the machine tool based on the detected configuration of the cutting edge 14. The control device 18 optimizes the at least one cutting parameter of the machine tool such that further cutting edges created with the machine tool using the optimized cutting parameter have no burr 30 or have a burr 30 that is significantly reduced in its severity. The control device 18 is configured to transmit the at least one optimized cutting parameter of the machine tool to the machine tool.

[0063] Fig. 4 shows a schematic layout of a flow production line 100 with the device 10 of Fig. 1. The device 10 is arranged between the machine tool 20 in the form of the laser cutting machine and the machine tool 36 in the form of the painting machine. The flow production line also has a machine tool 38 in the form of a deburring machine.

[0064] After the cutting edge has been created with the laser cutting machine 20, the workpiece 12 is fed to the device 10. The device 10 detects the formation of the cutting edge 14 and, based on the detected formation of the cutting edge 14, releases the workpiece 12 for painting with the painting machine 36. Based on the release by the device 10, the workpiece 12 is fed to the painting machine 36.

[0065] If the device 10 does not release the workpiece 12 for painting with the painting machine 36 and determines the deburring of the cut edge 14 as the upstream processing step, the workpiece 12 is fed to the deburring machine 38. After the cut edge 14 has been deburred with the deburring machine 38, the workpiece 12 is fed to the device 10. The device 10 detects the formation of the deburred cut edge 14 and, based on the detected formation of the deburred cut edge 14, releases the workpiece 12 for painting with the painting machine 36. Due to the release by the device 10, the workpiece 12 is fed to the painting machine 36.

[0066] In an alternative embodiment (not shown), the device does not release the workpiece after deburring the cut edge and determines a further deburring of the cut edge as an upstream processing step. The workpiece is again fed to the deburring machine for deburring the cut edge. After the cut edge has been deburred again with the deburring machine, the workpiece is fed to the device for the purpose of releasing or not releasing the workpiece.

[0067] In another alternative embodiment (not shown), the device does not release the workpiece after deburring the cut edge and determines a new cut edge as an upstream processing step. The workpiece is fed to the machine tool for new cut edge production. After the cut edge has been produced again with the machine tool, the workpiece is fed to the device for the purpose of releasing or not releasing the workpiece.

[0068] In another alternative embodiment (not shown), the device does not release the workpiece after deburring the cut edge and determines that the next processing step is to remanufacture the workpiece. The workpiece is sent to the waste collection, and the machine tool is instructed to remanufacture the workpiece.

[0069] Fig. 5 shows a flow diagram of a method for operating the device 10. The method has the steps: a) detecting the formation of the cutting edge 14 and b) releasing or not releasing the workpiece 12 for the processing process based on the detected formation of the cutting edge 14. At the same time as step b) the step is carried out: c) optimizing at least one cutting parameter of the machine tool 20 based on the detected formation of the cutting edge 14. In the example shown in Fig. 5 the workpiece 12 has been released in step b). After the release of the workpiece 12 the steps are carried out: d) determining a parameter of the processing process based on the detected formation of the cutting edge 14 and e) determining based on the detected formation of the cutting edge 14 whether turning the workpiece 12 is necessary for the processing process.Steps d) and e) are performed simultaneously. Alternatively, steps d) and e) can be performed consecutively.

[0070] Fig. 6 shows a further schematic flow diagram of the method of Fig. 5. In contrast to the flow diagram of Fig. 5, in step b) the workpiece 12 has not been released. After the workpiece 12 has not been released, the following step is carried out: f) determining a processing process prior to the processing process based on the detected formation of the cutting edge 14 from a set of predetermined upstream processing processes.

[0071] As the exemplary embodiments shown and explained make clear, the invention provides a device and a method for operating a device which ensure a high quality of a processing process and / or which increase a degree of automation, in particular of a flow production.

Claims

Patent claims 1. Device (10) for releasing a workpiece (12) with a cutting edge (14) created by a machine tool (20) for a processing process, the device comprising: a detection device (16) for detecting a formation of the cutting edge (14), and a control device (18) which is designed to release or not release the workpiece (12) for the processing process based on the detected formation of the cutting edge (14).

2. Device (10) according to claim 1, wherein the processing process comprises deburring the cut edge (14), welding the workpiece (12), bending the workpiece (12), painting the workpiece (12) and / or punching the workpiece (12).

3. Device (10) according to one of the preceding claims, wherein the control device (18) is designed to determine a parameter of the processing process based on the detected formation of the cutting edge (14).

4. Device (10) according to claim 3, wherein the parameter of the processing process comprises a deburring parameter, a welding parameter, a bending parameter, a painting parameter and / or a punching parameter.

5. Device (10) according to one of the preceding claims, wherein the control device (18) is designed to determine a material parameter of the workpiece (12) and / or an orientation of the workpiece.

6. Device (10) according to one of the preceding claims, wherein the control device (18) is designed to determine, based on the detected formation of the cutting edge (14), whether turning the workpiece for the processing process is required.

7. Device (10) according to one of the preceding claims, wherein the control device (18) is designed to determine a processing process prior to the processing process based on the detected formation of the cutting edge (14) from a set of predetermined upstream processing processes.

8. Device (10) according to one of the preceding claims, wherein the set of predetermined upstream processing processes comprises at least deburring of the cutting edge (14) and / or grinding of the cutting edge (14).

9. Device (10) according to one of the preceding claims, wherein the control device (18) is designed to determine at least one cutting parameter of the machine tool (20) based on the detected formation of the cutting edge (14) to be optimized.

10. Device (10) according to one of the preceding claims, wherein the detection device (16) comprises an optical sensor (22), a tactile sensor (24) and / or an acoustic sensor (25) for detecting the formation of the cutting edge (14).

11. Device (10) according to one of the preceding claims, wherein the device (10) has a manipulator (26) for gripping, moving and / or manipulating the workpiece (12), wherein the control device (18) is designed to control the manipulator (26).

12. Device (10) according to claim 11, wherein the detection device (16) is arranged on the manipulator (26).

13. A method for operating a device (10) according to any one of the preceding claims, wherein the method comprises the steps of: a) detecting the formation of the cutting edge (14), and b) releasing or not releasing the workpiece (12) for the processing process based on the detected formation of the cutting edge (14).

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