BEAM CUTTING METHOD, COMPUTER PROGRAM, AND BEAM CUTTING DEVICE

Abstract

The present invention relates to a beam cutting method, in which at least one cutting process is performed under the acquisition of at least one quality parameter, a process window (36, 36') is defined in a parameter space of at least one process parameter (f, v), in an unadjusted operation, one or more process parameters (f, v) are selected within the process window (36, 36'), in an adjusted operation, one or more process parameters (f, v) can be located outside the process window (36, 36'), and the process window (36, 36') is adjusted based on a change in the one or more process parameters (f, v) and / or a change in the at least one quality parameter in the adjusted operation.

Description

[Technical field]

[0001] The invention relates to a beam cutting method, in which at least one cutting process is performed under acquisition of at least one quality parameter. The invention also relates to a computer program for controlling a beam cutting device. Furthermore, the invention relates to a beam cutting device. [Background technology]

[0002] A beam cutting method of the above type is known, for example, from US Pat. No. 5,399,620 or US Pat. No. 5,499,620.

[0003] In particular, Patent Document 1 describes a machine learning device for a processing state adjustment device. The machine learning device observes laser processing state data in laser processing and gas target deviation data representing a target deviation of the pressure loss or the flow rate of the assist gas as state variables representing the current state of the environment. Then, the machine learning device acquires decision data for determining the quality of the processed workpiece based on the laser processing state, and learns in association with the target deviation of the pressure loss of the assist gas or the target deviation of the flow rate of the assist gas and the adjustment of the laser processing state in laser processing using the decision data and the observed state variables.

[0004] From DE 10 200 03 133 A1 a device for monitoring, in particular for regulating, the cutting process of a workpiece is known. The device comprises a focusing element for focusing a high-energy beam, in particular a laser beam, on the workpiece, an image acquisition device for acquisition of a monitored area on the workpiece, including an interaction area of ​​the high-energy beam with the workpiece, and an evaluation device designed for determining, based on the acquired interaction area, at least one characteristic parameter of the cutting process, in particular the kerf formed during the cutting process. The device may also comprise a control device and / or a regulating device for controlling and / or regulating the parameters of the cutting process in dependence on the at least one determined characteristic quantity.

[0005] Patent document 3 discloses a method for determining cutting parameters of a laser cutting machine, which includes the following steps: A) receiving at least one machine parameter, at least one process parameter, and / or at least one material parameter; B) outputting characteristics of a laser cutting edge that can be cut by a laser cutting machine, the characteristics being influenced by cutting parameters; C) receiving characteristic weights; D) determining cutting parameters using at least one machine parameter, at least one process parameter, and / or at least one material parameter, also using the weighted characteristics;

[0006] Patent document 4 describes a laser cutting device for cutting a workpiece along a cutting line by means of a laser beam at a variable cutting speed. The laser cutting device comprises a movable processing head for positioning the laser beam on the respective workpiece, a user interface for specifying the respective cutting line and for specifying a minimum path accuracy of the laser beam, and a control device for controlling the movement of the processing head along the cutting line relative to the respective workpiece and for controlling a number of process variables of the cutting process, in which a movement of the cutting path of the laser beam along the cutting line can be generated during the cutting process. A first partial quantity of the process variables only includes one or more process variables that influence the power of the laser beam available for cutting. A second partial quantity of the process variables only includes one or more process variables that do not influence the power of the laser beam available for cutting. At least one process variable of the second partial quantity is controllable by the control device in dependence on at least one variable control parameter, a respective value of which is determinable by the control device according to a rule implemented in the control device in dependence on at least one of the respectively registered values ​​of the speed of the processing head.

[0007] Disturbances occurring sufficiently strongly and rapidly during a beam cutting process, e.g. laser cutting, can lead to mis-cuts despite active adjustment of the process parameters of the cutting process, reducing the further cutting capacity of the beam cutting device. Disturbances can also affect the cutting capacity when cutting is performed without adjustment, i.e. with fixed process parameters. In both cases, the following is possible: when resuming an adjusted cut, mis-cuts can occur, despite active adjustment, and manual intervention by the operator is required to restore the cutting capacity of the beam cutting device. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] German Patent Application Publication No. 102019106939A1 [Patent Document 2] German Patent Application Publication No. 102013218421A1 [Patent Document 3] German Patent Application Publication No. 102019220478A1 [Patent Document 4] European Patent Application Publication No. 2163339A1 Summary of the Invention [Problem to be solved by the invention]

[0009] One object of the present invention is to improve the reliability of the beam cutting process. [Means for solving the problem]

[0010] According to the invention, this problem is solved by a beam cutting method according to claim 1, a computer program according to claim 14 and a beam cutting device according to claim 15. The dependent claims and the description present advantageous variants or embodiments.

[0011] According to the present invention, a beam cutting method is provided. Preferably, the beam cutting method is a laser cutting method. Alternatively, the method may be, for example, a plasma cutting method, a flame cutting method or a water beam cutting method. A preferably plate-like or tubular workpiece is cut by directing a beam, in particular a laser beam, onto the workpiece.

[0012] At least one cutting process is performed under the acquisition of at least one quality parameter. A cutting process is understood in this context to be in particular a process between the start and end of a separation cut, which cuts the workpiece in the thickness direction. Typically, within the scope of the method according to the invention, multiple cutting processes are performed. The multiple cutting processes can also be performed on the same workpiece or on different workpieces. The at least one quality parameter describes the quality of the separation cut. In particular, the at least one quality parameter can be selected from the presence of a separation cut (i.e. whether the workpiece is completely cut in the thickness direction or not), the width and / or extension of the cutting gap (e.g. oscillating periodically), the inclination and / or shape of the cutting front.

[0013] A process window is defined in the parameter space of at least one process parameter, preferably a plurality of process parameters. The process window represents a region in the parameter space where an effective and high-quality cut or at least a satisfactory cut can be expected based on prior information. The process window can be a point in the parameter space. In particular, the process window can be predefined as a point in the parameter space. During adjustment, the process window can remain a point or expand to a limited region. It is understood that the process window can alternatively be predefined as a limited region in the parameter space and during adjustment, can remain such a region or shrink to a point. In particular, the process parameters can be selected from feed rate, laser power, focal position, focal diameter, distance of the nozzle from the workpiece, gas pressure and / or gas composition of the cutting gas.

[0014] Preferably, the process window is predefined depending on the mechanical properties of the beam cutting device in which the method is performed and / or the workpiece properties of the workpiece to be cut, which makes it possible to take into account that these properties influence the values ​​of the process parameters at which an effective cut should be applied. The mechanical properties can be selected from the type of cutting head, the wavelength and / or the maximum power of the laser beam, the type and / or composition of the cutting gas, the type of nozzle, the type of fiber optic cable and / or the type of cutting optics. Alternatively or additionally, the mechanical properties can be selected from: - deviation of the focal position from the target value, for example due to heating of the optics or dirt on the protective glass (the actual focal position no longer coincides with the set focal position and the beam diameter may also change), - decentering of the laser beam with respect to the nozzle (which leads to a directional dependency), - nozzle defects, e.g. slag deposits (which can disrupt the gas beam and the melting discharge), the presence of a support web beneath the process zone during the cutting process (this can lead to problems, especially above a worn or slag-covered web); and / or - The purity of the cutting gas or the type and / or amount of impurities in the cutting gas. The workpiece characteristic may be selected from a workpiece material, a workpiece thickness, a workpiece temperature, and / or a workpiece surface characteristic.

[0015] According to the invention, at least one cutting process is carried out temporarily in unregulated operation and temporarily in regulated operation.

[0016] An unregulated run can also be described as a controlled run. In an unregulated run, the process parameters are selected within a process window. The control of the unregulated run is performed in the sense of feedforward control by specifying the process parameters within the process window without feedback of quality parameters. In particular, it can be provided that in each unregulated run step, the process parameters are not changed.

[0017] In the adjusted operation, the process parameters can be located outside the process window. In the regulated operation, the process parameters are changed depending on the obtained quality parameters. The adjusted operation is performed in the sense of feedback control by closed-loop control. The aim of the adjustment is, for example, to increase the cutting speed (feed rate) without significantly changing the cutting quality. In particular, the adjustment can be set to be performed as productively as possible, i.e. at the highest possible feed rate within the process window. Alternatively, the adjustment can be set to be performed as robustly as possible, i.e. to lead the process out of the quality window where an effective and good quality cut is achieved, a point in the process window is selected at which a disturbance must occur as strongly and / or quickly as possible (e.g. an adjustment that tends to lead to a slightly lower feed rate).

[0018] According to the invention, the process window is adjusted by utilizing knowledge from a previous run of at least one cutting process. For a subsequent unadjusted run, process parameters within the adjusted process window are selected. When adjusting the process window, its boundaries or perimeters can be changed.

[0019] In particular, the process window can be adjusted based on changes in the adjusted running process parameters. In this way, depending on the circumstances of the particular cutting process, it can be taken into account that the previously defined process window can be terminated without jeopardizing an effective cutting process, or that an effective cutting process cannot be guaranteed even within the previously defined process window. Preferably, a continuous adjustment of the process window is performed.

[0020] Alternatively or additionally, the boundaries of the process window can be adjusted based on a change in at least one quality parameter, which can be obtained in an unadjusted or adjusted run, in which case quality changes that occur naturally or independently of changes in the process parameters, such as, for example, splashes on a protective glass or slag accumulation on a nozzle, or continuous changes, such as, for example, heating of the optics, can be taken into account and their effects can be compensated for.

[0021] By adjusting the process window, experience from previous cutting processes is incorporated into the determination of process parameters for the subsequent unadjusted run. The use of an adjusted process window can thereby increase the reliability of the cutting process and improve the cutting quality. Disturbances in the course of the cutting process, which previously had to be corrected by manual intervention by an operator, are compensated for in the method according to the invention by adaptive adjustment of the process window. In other words, experience from previous cutting processes acts in determining the current process window, i.e. the current process window is a function of available information (e.g. all relevant and available quantities, such as all time sequences, process parameters, quality parameters of the sensor system, parameters such as cutting direction, cutting position, etc.). Depending on the operating mode, the cutting process can be continued within the current process window, both in an adjusted run and in an unadjusted run, and appropriate instructions can be defined for this purpose.

[0022] It is particularly preferred that the process window is adjusted continuously or iteratively, so that it can always be adapted to the current situation. A particularly high level of process stability can be achieved as a result. For example, a gradual adjustment can be made at each of several cutting interruptions.

[0023] Preferably, the change in the process parameter and / or the change in the at least one quality parameter in the adjusted run is obtained in a position-dependent and / or direction-dependent manner. Correspondingly, the process window can be adjusted in a position-dependent and / or direction-dependent manner, whereby anisotropy or non-uniformity of the cutting device in the working space can be taken into account and compensated. Alternatively or additionally, the change in the process parameter and / or the change in the at least one quality parameter in the adjusted run can be obtained in a time-dependent manner and the process window can be adjusted in a time-dependent manner.

[0024] When adjusting the process window, it is also possible to take into account how much time ago or how late the information about the cut position or cut direction was available. If the cut was made in the same cut direction only a few seconds ago, it is highly likely that the machine is still in a similar state, whereas if the cut was made more than a minute ago, it is highly likely that the machine is no longer in a similar state. The process window is therefore also a function of the time progression of the available information. Thus, the time aspect can be taken into account when adjusting the process window.

[0025] It is also possible to adjust the process window when the machine configuration is changed. A change in the machine configuration is understood to mean, in particular, the replacement or cleaning of parts of the beam cutting device, such as, for example, the nozzle or the protective glass. Thus, the various influences of new or damaged or dirty parts on the cutting process can be taken into account. Thermal effects, such as, for example, temperature-related changes in the focal position, can also be considered as a change in the machine configuration. This makes it possible to address recurrent influences due to heating of the cutting device during operation or due to cooling during interruptions in operation.

[0026] Upon occurrence of a predefined (process- or cutting-related) event, the process window can be adjusted in a predefined manner. Predefined events are, for example, a cutting interruption, a collision, in particular a collision of the nozzle with a workpiece or an apparatus part, or a manual parameter change. By applying an appropriate correction of the process window to such an event, it can be achieved that a reliable cutting process is possible after the corresponding event even in unadjusted operation. In contrast, if the parameter values ​​are not changed, such an event may subsequently cause an erroneous cut.

[0027] The tolerance region for adjusting the process window can be predefined. This prevents the process window from shifting into a region that is far beyond the normal parameter values. In particular, excessive shifting of the process window in one step (during one adjustment) can be prevented. This prevents singular events in which the process window shifts into a region that is not suitable for subsequent cutting in a non-adjusted run. Furthermore, this prevents incorrect setups, e.g., incorrect metal sheet thicknesses are set, incorrect double metal sheets are set, or incorrect parameter sets are selected for the correct metal sheet thickness.

[0028] If the adjusted process window and / or the process parameters set in the adjusted run reach the boundaries of the tolerance region, the cutting process can be interrupted and / or a message can be issued, so that the selection of process parameters at the boundaries of the tolerance region can be interpreted and used as a warning of a serious fault or malfunction.

[0029] The use of unregulated operation can be used in predefined situations, taking into account that certain situations in the cutting process may not be satisfactorily controlled in some cases with the regulation strategies provided in regulated operation. In contrast, the reference values ​​of the process parameters within the (possibly regulated) process window allow the safe execution of the cutting process in predefined situations. After the end of the predefined situations, a switchover is essentially made to regulated operation. The execution of unregulated operation within the regulated process window significantly increases the certainty that the cutting process is in a stable state where it can be regulated.

[0030] It may be provided that the initiation of the cutting process, in particular of each cutting process, takes place in unregulated operation, whereby a (possibly regulated) process window ensures that the cutting process is effectively started, which serves as the basis for the subsequent adjustment of the process parameters in regulated operation.

[0031] It may be provided that during the unregulated run, a change in direction of the cutting direction exceeds a predefined time or space gradient or a predefined curve. Such an abrupt change in direction may cause the laser cutting device to become temporarily unable to measure and therefore unable to regulate, or the regulation, due to its inertia, may not be able to keep the process within the quality window during or after cornering. Therefore, for an effective execution of the cutting process, a switch is made to the unregulated run before a large change in direction. After the end of the change in direction, the cutting process proceeds to the regulated run.

[0032] The process parameters in the unadjusted working run can be selected up to the boundaries of the process window with a safety buffer, as long as the process window includes a region in the parameter space, which further improves the reliability of the cutting method.

[0033] The safety buffer may depend on the type of production mode. The production mode may be used to focus the method execution on maximizing reliability or on increasing productivity. The production mode may be, for example, a safety mode for unattended operation or a production mode for increasing productivity. In the safety mode, a larger safety buffer is specified than in the production mode.

[0034] Alternatively or additionally, the safety buffer can depend on the time since the last adjustment of each boundary of the process window, thereby taking into account that machine or workpiece characteristics may change over time, and if the last adjustment of the boundary of the process window was made a long time ago, these changes may not yet be taken into account in the determination of the process window.

[0035] The scope of the invention also includes a computer program comprising program instructions which, when the computer program is executed on a control device of a beam cutting device, in particular a laser cutting device, cause the control device to execute the method according to the invention as described above, said computer program allowing a simple retrofitting of existing beam cutting devices for the execution of the method according to the invention.

[0036] Also included within the scope of the present invention is a computer readable storage medium having stored thereon a computer program according to the present invention.

[0037] The invention also includes a beam cutting device, in particular a laser cutting device, with a control device configured to execute the method according to the invention described above. The beam cutting device may comprise a cutting head movable relative to a workpiece holder for holding the workpiece. The cutting head may comprise a protective glass for the optics. The cutting head may comprise a nozzle by which cutting gas can be directed towards the workpiece. The beam cutting device may comprise one or more sensors for the acquisition of at least one quality parameter.

[0038] Further features and advantages of the invention are evident from the claims, the description and the drawings. According to the invention, the features mentioned above and those described in more detail can be used individually or in any suitable combination. The presented and described embodiments are not to be taken as an exhaustive list, but rather have an exemplary character for the explanation of the invention.

[0039] The invention is illustrated in the drawings and will be explained on the basis of examples. [Brief description of the drawings]

[0040] [Figure 1] 1 is a schematic side view of a beam cutting device according to the present invention; [Diagram 2] 2 is a schematic top view of the beam cutting device of FIG. 1. [Diagram 3] FIG. 1 is a schematic diagram of a pre-set process window and a process window with adjusted boundaries in a parameter space of process parameters; [Figure 4] 3 is a schematic flow chart of a cutting method according to the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] Figure 1 shows a beam cutting device, in this embodiment a laser cutting device 10. A workpiece 14, in this embodiment a metal plate, is held in a work holder 12 of the laser cutting device 10 (see also Figure 2). The laser cutting device 10 comprises a cutting head 16. The cutting head 16 can be moved relative to the work holder 12 along a number of translation axes 18, 20, 22. Furthermore, the cutting head 16 can be rotated about one or more rotation axes in a manner not shown in detail.

[0042] The cutting head 16 emits a laser beam 24 to cut the workpiece 14. The workpiece 14 is cut by the laser beam 24 along a trajectory 26. The cut can start from a piercing point 27. The trajectory 26 is shown in the present embodiment as a closed contour by way of example. Alternatively, the trajectory can have several separate processing sections and intermediate transfer sections (not shown in detail). To assist the processing of the workpiece 14 by the laser beam 24, the cutting head 16 can have a nozzle 28. A cutting gas can be sprayed onto the workpiece 14 through the nozzle 28. The cutting head 16 can also have a protective glass 29 for an optical system, not shown in detail.

[0043] The laser cutting device 10 comprises a controller 30, which performs the cutting process by specifying and adjusting various process parameters. Two of the process parameters may be, for example, the feed rate v and the focal position f (i.e., the position of the focal point of the laser beam 24 relative to the workpiece 14), see FIG. 3. Further process parameters may be the laser power, the focal diameter, the gas pressure of the cutting gas before leaving the nozzle 28, the mass flow rate of the cutting gas through the nozzle 28, and / or the distance 34 of the nozzle from the workpiece 14. Overall, the process parameters span a multi-dimensional parameter space, a two-dimensional projection of which is shown by way of example in FIG. 3.

[0044] The laser cutting device 10 further comprises a sensor system 32. The sensor system 32 may include a number of sensors, not shown in detail, for determining quality parameters of the cutting process. The sensors may be arranged, for example, in or on the cutting head 16. Some of the sensors may also be arranged elsewhere in or around the laser cutting device 10. In particular, the sensor system 32 may comprise an optical sensor, in particular a camera. The sensor system 32 may preferably make it possible to determine the quality of the cut edge, the width of the kerf, the inclination of the cutting front and / or the presence of a separation cut or a miscut.

[0045] For the execution of the cutting method, a process window 36 (see FIG. 3) is predefined in the parameter space of the process parameters (see step 102 in FIG. 4). The definition of the process window 36 is first performed for undisturbed conditions corresponding to the nominal conditions of the laser cutting device 10 and the workpiece 14. In so doing, machine properties such as the type of cutting head 16, the wavelength of the laser beam 24, the type of cutting gas and / or the type of nozzle 28 can be taken into account. Furthermore, workpiece properties such as the material of the workpiece 14, the thickness of the workpiece 14 and / or the surface condition of the workpiece 14 can be taken into account.

[0046] 3 further shows a quality boundary 38, at which the cutting process changes from an effective to an erroneous course. To the left of the quality boundary 38, a separation cut of sufficient quality is performed, whereas to the right of the quality boundary 38, an erroneous cut is performed. The process window 36 is located in a region of the multidimensional parameter space that allows the separation cut to be performed effectively with sufficient quality. In particular, the process window 36 can be preset at a certain distance from the quality boundary 38. This allows a high-quality separation cut to be achieved.

[0047] In step 104, a working point 40 is selected within the process window 36. The working point 40 may be specified with a safety buffer relative to the boundary or periphery of the process window 36. The safety buffer may be selected depending on the productivity or reliability requirements of the production mode.

[0048] The cutting process is started at the piercing point 27 with the process parameters selected according to the working point 40 (see step 106). The cutting process is therefore started in unregulated operation with the determined process parameters without feedback of quality parameters, which, if possible, are also acquired in unregulated operation by the sensor system 32 (see extended step 108 in FIG. 4).

[0049] After a short section of the trajectory 26 has been cut with the specified process parameters, a switchover to regulated operation is made. In a further step, the cutting process is adjusted under feedback of the quality parameters acquired by the sensor system 32 and by changing the process parameters according to a pre-defined regulation strategy (see step 110). In the process, the process parameters can deviate from the initially specified process window 36.

[0050] During the cutting process, disturbances may occur, for example splashes may soil the protective glass 29. The control device 30 recognizes this on the basis of a deterioration of the quality parameters acquired by the sensor system 32. Disturbances may cause the position of the quality boundary 38' to change in the parameter space.

[0051] The controller then responds by adjusting the process parameters in the adjusted run, for example, the feed rate v can be reduced, the focal position f can be moved closer to the workpiece 14, and the laser power can be increased.

[0052] Based on the process parameter values ​​thus changed, in step 112 the process window is adjusted to have a size, shape and position, which is shown as 36' in Fig. 3. The adjustment of the process window 36' can then be performed continuously or iteratively. In particular, the current processing position in the working space and / or in the cutting direction can be taken into account, so that different process windows are obtained depending on the position or direction and / or depending on the time (not shown in detail). The adjustment of the process window 36' can be limited to a tolerance region 41.

[0053] In a further process, the trajectory 26 can have an abrupt direction change 42. With the selected adjustment strategy and with such abrupt direction changes, there can be a risk of cutting interruption, for example, if there is a strong direction dependency and the adjustment is too slow or if the laser cutting device is not capable of measuring at such a sharp turn. For this reason, a new working point 40' is selected in the adjusted process window 36' when step 104 is executed again. The cutting process in the area of ​​the direction change 42 is then carried out in unadjusted operation (see step 114), with the process parameters being selected at the adjusted working point 40'. If the dynamics of the laser cutting device 10 do not allow the feed rate to be selected depending on the working point 40' in the area of ​​the direction change 42, the cutting process can be carried out there at a lower feed rate. In order to achieve good quality even at low feed rates, additional process parameters (for example laser power) can then be adjusted. The feed rate at the working point 40' serves as a boundary value that is not exceeded in the area of ​​the direction change 42. As long as dynamics permit, the feedrate is set to a value that corresponds to work point 40' in an uncoordinated run.

[0054] After passing the abrupt direction change 42, the process switches back to the adjusted run according to step 110. Before switching to the adjusted run, for example, the feed rate can be brought to the value last used in this direction in the previous adjusted run in the direction-dependent area of ​​the process window 36'. Alternatively, a lower value can be selected to achieve greater safety, especially if the last cut in the new direction was made some time ago.

[0055] The above procedure can be repeated on the workpiece 14 in further progression of the cutting process. As described above, it can also be used for a further cutting process with new drilling on the workpiece 14 or another workpiece, in which case the working point in step 104 is selected within the current process window 36'.

[0056] When the soiled protective glass 29 is cleaned or replaced, the process window 36' is adjusted so that its boundaries again correspond to those of the process window 36, in particular if no other disturbances have occurred in the meantime.

[0057] A predetermined adjustment of the process window may also be made in the event of a particular event, such as, for example, a collision between the nozzle 28 and the workpiece 14 or a cut interruption. For example, if a cut interruption occurs, the feed rate within the adjusted process window may be reduced by a predetermined amount or factor relative to the feed rate at which the cut interruption occurred. Such cut interruptions may occur in both regulated and unregulated operation, for example, due to impaired flow of cutting gases or accumulation of slag on the nozzle 28. The process window is modified accordingly to allow the cut to continue and to prevent a new cut interruption prior to elimination of the cause.

[0058] In summary, the beam cutting method includes an unadjusted operating mode (steps 104, 106, 114) and an adjusted operating mode (step 110). In both operating modes, quality parameters for the cutting process are obtained. In the unadjusted run, the process parameters are set to a working point within an adaptive process window. In the adjusted run, the process parameters are changed based on a predefined adjustment strategy under consideration of the quality parameters, whereby the process parameters can exceed the boundaries of the previous process window. The changes in the process parameters in the adjusted run are used for adjusting the boundaries of the process window for the unadjusted run. The next stage of the unadjusted run is performed at a working point within the adjusted process window. Therefore, the process parameters in different stages of the unadjusted run are typically different from each other. [Explanation of symbols]

[0059] 10 Laser cutting equipment 12 Work holder 14 Work 16 Cutting Head 18, 20, 22 translation axis 24 Laser Beam 26 orbit 27 Drilling point 28 Nozzles 29 Protective Glass 30 Control device 32 Sensor System 34 distance 36, 36' process window 38, 38' quality boundary 40, 40' working point 41 Tolerance Area 42 Direction change point 102 Define the process window 104 Selecting a work point in the process window 106 Initiate the cutting process uncoordinated 108 Get quality parameters 110 Adjusted and cut off 112 Adjusting the Process Window 114 Disconnect in non-adjustment v Feed rate f focal position

Claims

1. 1. A method of cutting a beam, comprising: carrying out at least one cutting process under acquisition of at least one quality parameter, performing said at least one cutting process in a temporarily unregulated operation and in a temporarily regulated operation; defining a process window (36, 36') in a parameter space of at least one process parameter (f, v); selecting said at least one process parameter (f, v) within said process window (36, 36') in an unadjusted run; In a coordinated operation, the at least one process parameter (f, v) can be located outside the process window (36, 36′); The beam cutting method, further comprising adjusting the process window (36, 36') based on a change in the at least one process parameter (f, v) and / or a change in the at least one quality parameter during the adjusted run.

2. 2. The method of claim 1, wherein said beam cutting method is a laser cutting method.

3. measuring the change in the process parameters (f, v) during the adjusted operation and / or the change in the at least one quality parameter; position-dependent and / or orientation-dependent and / or time-dependent acquisition; 3. A method according to claim 1 or 2, characterized in that the process window (36, 36') is adjusted position-dependently and / or direction-dependently and / or time-dependently.

4. Method according to any one of the preceding claims, characterized in that the process window (36, 36') is adjusted during changes in the machine configuration.

5. Method according to any one of the preceding claims, characterized in that upon the occurrence of a predefined event, the process window (36, 36') is adjusted in a predefined manner.

6. The method according to any one of the preceding claims, characterized in that a tolerance region (41) for the adjustment of the process window (36, 36') is predefined.

7. 7. The method according to claim 1, wherein the initiation of the cutting process is performed in the unregulated operation.

8. The method according to any one of the preceding claims, characterized in that a change in direction (42) of the cutting direction is performed during said uncoordinated operation, exceeding a predefined temporal or spatial gradient.

9. Method according to any one of the preceding claims, characterized in that the process parameters (f, v) in the unregulated run are selected up to the boundaries of the process window (36, 36') with a safety buffer.

10. 10. The method of claim 9, characterized in that the safety buffer depends on the type of production mode and / or on the time elapsed since the last adjustment of the process window (36, 36').

11. Method according to any one of claims 1 to 10, characterized in that the at least one quality parameter is selected from the presence of a separation cut, the width and / or the extension shape of the cutting gap and / or the inclination and / or the shape of the cutting front.

12. 12. The method according to claim 1, characterized in that the process parameters (f,v) are selected from the feed rate, the laser power, the focus position, the focus diameter, the distance (34) of the nozzle (28) from the workpiece (14) and / or the gas pressure and / or the gas composition of the cutting gas.

13. Method according to any one of the preceding claims, characterized in that the process window (36, 36') is defined in dependence on machine properties and / or workpiece properties.

14. A computer program comprising program instructions, A computer program which, upon execution of the computer program in a control device (30) of a beam cutting device, causes the control device to carry out the method according to any one of the preceding claims.

15. A beam cutting device comprising: A beam cutting device comprising a control device (30) configured to carry out the method according to any one of the preceding claims.

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