Method and device for changing processing parameter values during a steel processing method
Patent Information
- Application Number
- EP2023734205
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-06-23
- Filing Date
- 2023-06-19
- Publication Date
- 2025-04-30
AI Technical Summary
During beam processing, especially laser cutting, manual reduction of feed speed to prevent damage to machine components at high laser powers is challenging, as existing methods do not automatically adjust other parameters like laser power, leading to potential damage from excessive energy.
A method and system that allows for manual adjustment of feed speed during beam processing, with automatic adjustment of laser power based on the changed feed speed to maintain controlled power levels, preventing damage to machine components by reducing laser power proportionally or setting a minimum power value.
Enhances process reliability by maintaining controlled power levels during feed speed reduction, preventing damage to machine components and ensuring safe operation even at high laser powers, particularly above 10 kW.
Smart Images
Figure 1.1
Abstract
Description
[0001] Method and device for changing processing parameter values during a beam processing process
[0002] Field of the invention
[0003] The invention relates to the field of beam processing methods, in particular laser processing methods. In particular, the invention relates to a method and a device for changing processing parameter values from predetermined values during a beam processing method.
[0004] State of the art
[0005] In the context of beam processing, it is known that when the processing speed, i.e. the feed rate of the processing beam relative to the workpiece surface to be processed, changes, other processing parameters must be adjusted accordingly. When laser cutting metallic workpieces, for example, it is common practice to reduce the feed rate of the cutting beam when cutting corners or tight radii in order to achieve good cut quality in these contour areas. When reducing the feed rate, other cutting parameters usually also need to be adjusted to achieve optimal cutting results. These other cutting parameters include, among others, the laser power, the cutting gas pressure, the focus position, the distance of the cutting head from the workpiece, and others.Such parameter changes during the machining of a workpiece are usually pre-programmable and can be selected depending on the contour to be machined, so that a processing machine that carries out the machining process adjusts the parameter values independently.
[0006] From DE10040920A1, for example, a method for process control of a laser material processing process is known, in which a travel speed of the laser processing head is set manually or automatically and the laser power is adjusted when the travel speed changes according to a predetermined dependency on the travel speed.
[0007] Blasting systems also offer the option of manually controlling the feed rate during the machining process, for example, using a potentiometer. By manually intervening in the ongoing process, operators can manually reduce the feed rate from the specified value to gain a better overview and allow time to consider the situation in the event of hazards being discovered at short notice. Even when implementing new machining processes where the optimal machining speed has not yet been determined, operators can work their way closer to the optimal feed rate by manually adjusting the speed.
[0008] When the feed rate is changed manually during an ongoing machining process, other machining parameters generally do not adjust. In this way, the operating personnel can, for example, deliberately create excess power in the machining process by reducing the feed rate, thereby increasing process reliability during laser cutting. However, as the laser power increases, the problem arises that excessive power can damage or even destroy the workpiece support area and other machine components. There is therefore a need for a solution for feed rate regulation - especially manual one - that does not endanger machine components, in particular the workpiece holder or workpiece support, even at high nominal powers of the beam processing machine (for a laser cutting machine, for example, from 10 kW laser power).
[0009] The invention
[0010] To achieve the object underlying the invention, a method for changing processing parameter values during the execution of a beam processing process is provided. In other words, values for processing parameters are already specified (e.g., preprogrammed) for the beam processing process, with which the process is carried out and which can be changed in addition to preprogrammed changes.
[0011] The method comprises, in a first step, changing a feed rate of the jet processing method compared to a predetermined feed rate. The feed rate is the speed at which the processing beam of the jet processing method is moved relative to a workpiece surface to be processed. The feed rate can preferably be changed manually, e.g., by means of a potentiometer. The predetermined feed rate is understood, in particular, to be a feed rate preprogrammed for the jet processing method. The predetermined feed rate does not have to be a constant feed rate. For example, the predetermined feed rate can be preprogrammed with different values along a contour of a workpiece to be processed.For example, the feed rate specified for a machining process can be higher along a straight contour section than along a curved or corner section of the contour to be machined. The change in the feed rate according to the invention refers to the feed rate values specified for the machining process, regardless of whether these already differ from one another.
[0012] In a second step, the method comprises changing the value of a second processing parameter of the beam processing method relative to a value specified for the second processing parameter and depending on the change in the feed rate according to the first step. The feed rate can also be understood as the first processing parameter within the scope of this disclosure.
[0013] With regard to the second processing parameter, it is also understood that the specified processing parameter values refer to the values preprogrammed for the current beam processing process. A change in the second processing parameter value according to the invention therefore occurs, in particular, only when the values of the second parameter are changed compared to the parameter values preprogrammed for the current processing process.
[0014] According to the present invention, the second machining parameter is automatically adjusted in response to a preferably manual change in the feed rate, according to a predeterminable dependency on the feed rate. This allows for better control of the process, especially during significant changes in the feed rate.
[0015] According to one variant, the values of further processing parameters (third, fourth, fifth processing parameters, etc.) specified or preset for the beam processing process can also be changed automatically, analogous to the change of the second processing parameter value, depending on the change in feed rate.
[0016] The beam processing method can preferably be a laser processing method, in particular a laser cutting method. In principle, however, the invention can also be applied to other beam processing methods, such as electron beam machining, other thermal cutting or joining methods, water jet cutting, and other related methods.
[0017] When the invention is used in a laser processing method, the second processing parameter can preferably be a laser power. However, the second processing parameter can also be, for example, the focus position of the processing laser beam, the distance between a processing head and the workpiece surface, or the pressure of a process gas used for the laser processing method. If the feed rate is reduced, the laser power can preferably be reduced according to the present invention. If the feed rate is reduced compared to predetermined values, there is a risk, according to the prior art, of excessive power, which can damage or destroy machine components. For example, when laser beam cutting a plate-shaped metallic workpiece, the energy per unit length of the processing beam that passes through the generated cutting gap onto the workpiece support (in particularThe impact of the laser beam (e.g., a metal grating) can be so high that the workpiece support is deformed or melted. Automatically reducing the laser power when the feed rate is manually reduced can prevent uncontrolled power overload and subsequent damage to machine components.
[0018] According to a preferred variant, if the feed rate is reduced by up to 30% compared to the predetermined feed rate, the laser power can be reduced to a lesser extent than the feed rate, or at least not at all. For example, if the feed rate is manually reduced by up to at least 10%, e.g. by approximately 20%, compared to the pre-programmed feed rate, the laser power can be reduced to a lesser extent. In this way, a controlled power surplus can be generated, which can increase process reliability in the relevant machining section. If the feed rate is reduced further, the laser power can also be reduced, preferably to the same extent as the feed rate. In this way, the power surplus generated at the beginning of the feed deceleration can be maintained in a controlled manner as the feed rate is further reduced.
[0019] A linear relationship can preferably exist between the change in feed rate according to the invention and the change in laser power. According to a further variant, a minimum value can be specified for the laser power, wherein the laser power is maintained at the minimum value upon reaching the minimum value with a further reduction in the feed rate. The minimum value for the laser power can be selected such that, regardless of the feed rate, damage to machine components can be at least largely ruled out. When the processing beam comes to a complete standstill, i.e., when the feed rate is reduced to zero, the laser power can also be reduced to zero, particularly abruptly.
[0020] The laser power of a laser processing method in which a method according to the invention is carried out can preferably be at least 10 kW. This means that the laser power specified for the laser processing method can be at least 10 kW, at least in certain sections. At lower laser powers, damage to machine components is generally less critical. Therefore, the positive effects of the present invention are particularly pronounced in the specified range starting at 10 kW laser power.
[0021] To achieve the object underlying the invention, a laser cutting method for cutting a plate- or tubular workpiece is further provided, in which the method is implemented according to at least one of the variants described above. The laser cutting method comprises, in a first step, providing a plate- or tubular workpiece. The workpiece can, for example, consist of a metallic material, in particular structural steel, and / or have a thickness of at least 2 mm, preferably at least 10 mm.
[0022] In a second step, the laser cutting process involves cutting the workpiece using a specified feed rate and a specified laser power. As stated above, the specified laser power can be at least 10 kW. The specified feed rate of the cutting beam can vary along the contour depending on the contour to be cut.
[0023] In a third step, the laser cutting method comprises a manual change, in particular a reduction, of the feed rate compared to the specified feed rate; and in a fourth step, an automatic change of the laser power compared to the specified laser power and depending on the change in the feed rate.
[0024] Further advantageous variants of the laser cutting process arise in conjunction with the features of the method described above for changing processing parameter values, in this case, cutting parameter values. In particular, the laser power can only be reduced if the feed rate is reduced by at least 10%, e.g., 20%, compared to the specified feed rate. Alternatively or additionally, the laser power can only be reduced to a predefined lower limit, at which critical damage to machine components is highly unlikely or can even be ruled out, regardless of the feed rate of the cutting beam.
[0025] To achieve the object underlying the invention, a beam processing system is further provided. The beam processing system can, in particular, be a laser cutting system. The beam processing system comprises a beam processing machine, in particular a laser cutting machine, designed for processing plate- or tubular, in particular metallic, workpieces. Furthermore, the beam processing system comprises a control device designed to control the beam processing machine to carry out a beam processing method, in particular a laser cutting method, with predeterminable processing parameters; as well as a controller for manually changing the feed rate from a predefined feed rate during the beam processing method.The control device is configured to change the value of a second processing parameter, in particular the value of a laser power, compared to a predetermined value for this processing parameter and depending on the manual change of the feed rate.
[0026] The control device can comprise a control panel for inputting commands to the beam processing machine, with the controller being arranged on the control panel. Using the controller, which can preferably be designed as a rotary controller, the feed rate can be manually changed during the automated, particularly preprogrammed, processing process. The controller can preferably be a potentiometer. The controller can also be implemented, for example, as a touch function in a touch display of the control panel.
[0027] To achieve the object underlying the invention, a computer program product is further provided which contains computer-readable information for carrying out a method according to one of the variants described above.
[0028] Preferably, the computer program product, which may comprise a computer program with a program code, can be readable by the control device of a beam processing system as described above.
[0029] Examples of implementation
[0030] The following description of preferred embodiments, in conjunction with the drawings, serves to explain the invention in more detail.
[0031] They show:
[0032] Fig. 1 shows a laser cutting machine for laser beam cutting in a schematic, perspective view; Fig. 2 shows a control panel for entering control and / or
[0033] Control commands to a laser cutting machine according to Figure 1; and
[0034] Figs. 3 and 4 are diagrams each showing the dependence of a change in laser power on a change in feed rate according to the present invention.
[0035] Fig. 1 shows a laser cutting system 10 with a laser cutting machine 12 and a metallic workpiece 14 arranged on the laser cutting machine 12 for laser beam cutting. The laser cutting machine 12 preferably has a CO2 laser, a solid-state laser, or a diode laser as the laser beam generator 16, a movable cutting head 18, and a workpiece support 20 on which the metallic workpiece 14 is arranged. A laser beam 22 is generated in the laser beam generator 16 and guided from the laser beam generator 16 to the cutting head 18 by means of a fiber optic cable (not shown) or deflecting mirrors 24. The laser beam 22 is directed onto the metallic workpiece 14 by means of focusing optics arranged in the cutting head 18. The laser cutting machine 12 is also supplied with cutting gas 26—for example, oxygen and / or nitrogen.The cutting gas 26 is supplied to the cutting head 18—preferably under pressure control—from which it exits together with the laser beam 22. The laser cutting machine 12 further comprises a control device programmed to move the cutting head 18 relative to the metallic workpiece 14 according to a cutting contour 32. The control device comprises a control panel (not shown in Figure 1) on which control commands for the laser cutting machine 12 can be entered by operators of the laser cutting system 10.
[0036] Figure 2 shows a control panel 40 for a beam processing system according to the invention—in particular, a laser cutting system 10 according to Figure 1. In particular, the control panel 40 can be part of a control device of a laser cutting system or another beam processing system. The control panel 40 comprises a screen 42 for displaying functions and information for operating the beam processing system. Furthermore, the control panel comprises control and / or regulation elements 44a-e, with the aid of which, for example, the functions displayed on the screen 42 for setting and / or controlling processing processes that can be carried out by means of the beam processing system can be controlled. The screen 42 or display 42 can also comprise a touch function, which supplements or replaces the control and / or regulation elements 44a-e shown.For example, a cutting process for cutting the contour 32 can be set using the control panel 40 on a laser cutting system 10 according to Figure 1. To carry out the cutting process, cutting parameters are specified—e.g., depending on the material of the workpiece 14, the workpiece thickness, and / or the cutting contour. The cutting parameters can be based on a technology table stored in the control device of the laser cutting system 10. Among other things, a feed rate is specified at which the workpiece 14 is cut. The specified feed rate can be changed, in particular reduced, during the cutting process using a rotary control 44c of the control and / or regulating elements 44a-e.According to the invention, the laser power is also adjusted depending on the manual change in the feed rate in order to prevent a critical power increase in the cutting process and to protect the machine components from damage.
[0037] Examples of the dependence of laser power on feed rate in the case of manual (readjustment) of the feed rate are shown in Figures 3 and 4. The horizontal axis of the diagrams shows percentage values for the feed rate ("potentiometer position" or position of the rotary control 44c on the control panel 40) during a laser cutting process, with the value "100%" corresponding to the feed rate specified for the respective process and at the respective position of the cutting contour. The vertical axis shows the laser power—also as a percentage of the laser power specified for the current process. According to curve 50a in Figure 3, the laser power is initially maintained when the feed rate is reduced by up to approximately 15%. With a further reduction in the feed rate, the laser power is also reduced—here linearly with the feed rate.If the laser power reaches a minimum or minimum value of 50% of the specified laser power, it will not be reduced any further, even if the feed rate is further reduced. The minimum value can be specified variably depending on the requirements of the cutting process. The laser is only switched off, and the laser power reduced to 0%, when the cutting beam comes to a complete stop or immediately before stopping, i.e. when the feed rate is reduced to 0%. The delayed reduction in laser power when the feed rate is manually reduced can create a power surplus in the cutting process, and thus, if necessary, specifically increase process reliability. Setting a minimum value for the laser power can also help ensure process reliability.Preferably, the minimum value for the laser power can be selected such that damage to machine components - in particular damage to a workpiece support 20 (see Fig. 1) - can be at least largely excluded.
[0038] Figure 4 shows another example of a conditional change in laser power during manual adjustment of the feed rate in a laser cutting process. According to the illustration in Figure 4, the laser power is only reduced when the feed rate is reduced by more than 30%. A minimum value for the laser power is set at 20% according to Figure 4. This value is only exceeded when the feed rate is completely reduced to 0% or shortly before, namely by reducing the laser power to 0%.
Claims
Patent claims 1. Method for changing processing parameter values during the execution of a blast processing process, the method comprising the steps: Changing, preferably manually changing, the feed rate of the blast processing process from a predetermined feed rate; and Changing the value of a second processing parameter of the beam processing process relative to a value specified for the second processing parameter and depending on the change in feed rate.
2. The method according to claim 1, wherein the beam processing method is a laser processing method, in particular a laser cutting method.
3. Method according to claim 2, wherein the second processing parameter is a laser power.
4. The method of claim 3, wherein the laser power is reduced when the feed rate is reduced.
5. Method according to claim 3 or 4, wherein when the feed rate is reduced by up to 30% compared to the predetermined feed rate, the laser power is not reduced or is reduced to a lesser extent than the feed rate.
6. Method according to one of claims 3 to 5, wherein there is a linear relationship between the change in feed rate and the change in laser power.
7. A method according to any one of claims 3 to 6, wherein a minimum value can be specified for the laser power, and wherein the laser power is reduced upon reaching the The minimum value is maintained even with a further reduction in the feed rate.
8. Method according to any one of claims 3 to 7, wherein the laser power is at least 10 kW.
9. Laser cutting process for cutting a flat or tubular workpiece, the laser cutting process comprising: Providing a flat or tubular workpiece; Cutting the workpiece using a predetermined feed rate and a predetermined laser power; Manually changing, in particular reducing, the feed rate compared to the specified feed rate; and Automatic adjustment of the laser power relative to the specified laser power and depending on the change in feed rate.
10. Beam processing system (10) comprising: A shot blasting machine (12) designed for processing plate-shaped and / or tubular workpieces (14); A control device designed to control the blast processing machine (12) to carry out a blast processing process with predefinable processing parameters; A controller (44c) for manually changing the feed rate from a predetermined feed rate during the execution of the blast processing procedure; The control device is designed to change the value of a second machining parameter relative to a predetermined value for that machining parameter and depending on the manual change of the feed rate.
11. Beam processing system (10) according to claim 10, wherein the control device comprises an operating panel (40) for inputting commands to the beam processing machine (12); and wherein the controller (44c) is arranged on the operating panel (40).
12. Computer program product containing computer-readable information for carrying out a method according to any one of claims 1 to 9.
13. Computer program product according to claim 12, which is readable by the control device of a beam processing system (10) according to one of claims 10 to 11.