Laser processing machines and processing methods

Abstract

The laser processing machine (100) includes: a laser processing unit (1) that processes a workpiece (W) using a laser (L); an imaging device that captures images of the workpiece (W) irradiated by the laser (L); and a control device that controls the laser processing unit (1) according to processing conditions (51c) for processing the workpiece (W). The control device controls the operation of the laser processing unit (1) so that the size (OIS) of the optical image (OI) observed from the image information and the peak value (PV) of the light intensity (LI) of the optical image (OI) are close to preset reference values ​​(60), wherein the image information is obtained by the imaging device capturing images of the workpiece (W).

Description

Technical Field

[0001] This invention relates to laser processing machines and processing methods. Background Technology

[0002] Laser processing machines that use laser light irradiated from a laser oscillator to cut workpieces such as metal plates as the workpiece material to produce products of a desired shape are known, and include a device for monitoring the processing area of ​​the workpiece (for example, see Patent Document 1). This monitoring device includes at least one illumination device in the laser processing head that illuminates the processing area of ​​the workpiece, and monitors the processing area while illuminating it through the illumination device during multiple first time intervals and not illuminating it during second time intervals.

[0003] Furthermore, the electromagnetic radiation generated from the processing area during the first time interval and the second time interval are detected as images of the electromagnetic radiation of a video stream consisting of a first video stream and a second video stream with frame rates synchronized with the first and second time intervals.

[0004] By processing the electromagnetic radiation of the detected images individually, different types of detection results representing the processing area can be obtained, and multiple detection results of the same type can be combined to evaluate the processing status and appropriately control the laser according to the processing conditions.

[0005] Therefore, if an image of the laser processing area is obtained and monitored as described above, and the processing conditions are adjusted appropriately, online and / or real-time observation of the laser processing can be achieved, and automatic control and feedback control can be performed.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: International Publication No. 2019 / 110114 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] However, in the prior art monitoring device disclosed in the aforementioned Patent Document 1, an illumination device is provided on the laser processing head to obtain an image of the electromagnetic radiation of the processing area of ​​the illumination device. Therefore, the illumination light also illuminates a large area of ​​the processing area that is not illuminated by the laser, so the overall shape of the processing area can be grasped. On the other hand, the result of illuminating the processing area with laser is that an image of the light after combining the electromagnetic radiation that travels against the processing head with the light from the illumination device that illuminates the processing area and is reflected back to the processing head is obtained. As a result, there is a problem that the state of the light generated in the processing area cannot be accurately determined.

[0011] The present invention was made in view of the above circumstances, and its object is to provide a laser processing machine and processing method, which, when laser is irradiated onto the processing area, can accurately determine and respond to the state of light generated in the processing area and can control the laser processing.

[0012] Methods for solving problems

[0013] The laser processing machine of the present invention is characterized by comprising: a laser processing unit that processes a workpiece using a laser; an imaging device that images the workpiece irradiated by the laser; and a control device that controls the laser processing unit according to the processing conditions for processing the workpiece, the control device controlling the operation of the laser processing unit to make the size of the optical image observed from the image information and the peak value of the light intensity close to a preset reference value, wherein the image information is obtained by the imaging device capturing the workpiece.

[0014] In one embodiment of the present invention, the control device includes: a storage unit that stores the reference value; an image processing unit that parses the image information to calculate the size of the optical image and the peak value of the light intensity; and a control unit that operates the laser processing unit to make the size of the optical image and the peak value of the light intensity close to the reference value stored in the storage unit.

[0015] In other embodiments of the present invention, the processing conditions for the operation of the laser processing unit controlled by the control device include the focal position of the laser and the processing speed of the laser relative to the workpiece.

[0016] In another embodiment of the invention, the control device performs the following control: when the size of the optical image is smaller than the reference value, it controls the operation of the laser processing unit to increase the processing speed and / or raise the focal position; and when the size of the optical image is larger than the reference value, it controls the operation of the laser processing unit to decrease the processing speed and / or lower the focal position.

[0017] In another embodiment of the invention, the control device performs the following control: when the peak value of the light intensity is smaller than the reference value, it controls the operation of the laser processing unit to increase the processing speed and / or decrease the focal position; and when the peak value of the light intensity is larger than the reference value, it controls the operation of the laser processing unit to decrease the processing speed and / or increase the focal position. Furthermore, the control device controls at least one of the focal position and the processing speed to cause the size and / or the peak value observed from the image information to converge within a predetermined control range, wherein the predetermined control range includes the size and / or the peak value representing the reference value.

[0018] The processing method of the present invention is a processing method of a laser processing machine, the laser processing machine comprising: a laser processing unit that processes a workpiece using a laser; an imaging device that images the workpiece irradiated by the laser; and a control device that controls the laser processing unit according to processing conditions for processing the workpiece, the control device controlling the operation of the laser processing unit to perform processing so that the size of the optical image and the peak value of the light intensity observed from the image information meet preset reference values, wherein the image information is obtained by the imaging device capturing the workpiece.

[0019] Furthermore, in one embodiment of the present invention, the processing conditions are corrected so that the size of the optical image and the peak value of the light intensity are close to the reference value, and the operation of the laser processing unit is controlled according to the corrected processing conditions.

[0020] In other embodiments of the invention, the processing conditions to be corrected include the focal position of the laser and the processing speed of the laser relative to the workpiece.

[0021] Furthermore, in another embodiment of the present invention, when the size of the optical image is smaller than the reference value, the processing conditions are corrected to increase the processing speed and / or raise the focal position; when the size of the optical image is larger than the reference value, the processing conditions are corrected to decrease the processing speed and / or lower the focal position.

[0022] Furthermore, in another embodiment of the invention, when the peak value of the light intensity is smaller than the reference value, the processing conditions are corrected to increase the processing speed and / or decrease the focal position; when the peak value of the light intensity is larger than the reference value, the processing conditions are corrected to decrease the processing speed and / or increase the focal position. Additionally, the processing conditions are corrected by changing at least one of the focal position and the processing speed so that the size and / or the peak value observed from the image information converges within a predetermined control range, wherein the predetermined control range includes the size and / or the peak value representing the reference value.

[0023] Furthermore, in another embodiment of the present invention, the control device controls the operation of the laser processing unit according to the size of the optical image and the peak value of the light intensity so that the focal position of the laser and the cutting speed of the laser relative to the workpiece are close to preset reference conditions.

[0024] In another embodiment of the present invention, the laser processing machine further includes a learning unit comprising: a state observation unit that observes the size of the optical image and the peak value of the light intensity as state variables; and a decision unit that calculates a quality score based on a value representing how close the laser focal position and the processing speed of the laser relative to the workpiece are to the reference conditions, and the processing quality, and learns by associating the quality score with the state variables observed by the state observation unit to determine the processing conditions.

[0025] In another embodiment of the present invention, the control device controls the operation of the laser processing unit to perform processing based on the size of the optical image and the peak value of the light intensity, so that the focal position of the laser and the cutting speed of the laser relative to the workpiece are close to the preset reference conditions.

[0026] In another embodiment of the invention, the size of the optical image and the peak value of the light intensity are observed as state variables. A quality score is calculated based on the values ​​representing how close the laser focal position and the laser processing speed relative to the workpiece are to the reference conditions, as well as the processing quality. The quality score is then correlated with the observed state variables to learn and determine the processing conditions.

[0027] Furthermore, in another embodiment of the present invention, the laser processing machine further includes: a display unit that displays the calculated quality score; and a correction unit that corrects the focal position of the laser and the processing speed of the laser relative to the workpiece, which are the reference conditions.

[0028] Invention Effects

[0029] According to the present invention, the result of irradiating the processing area with laser is that the state of light generated in the processing area can be accurately determined and responded to, and the laser processing can be controlled. Attached Figure Description

[0030] Figure 1 This is an explanatory diagram showing a schematic structure of a laser processing machine according to one embodiment of the present invention.

[0031] Figure 2 It is a block diagram that roughly represents the functional structure of the laser processing machine.

[0032] Figure 3 This is a diagram illustrating an example of the parameters of an optical image observed from image information obtained by photographing a workpiece using this laser processing machine.

[0033] Figure 4 This is a diagram illustrating an example of the relationship between the optical image and the focal position of the laser and the processing speed (cutting speed) under the processing conditions of the laser processing machine.

[0034] Figure 5 This is a graph showing the relationship between the laser processing speed of the laser processing machine and the size of the optical image relative to a reference value.

[0035] Figure 6 This is a graph showing the relationship between the processing speed of the laser processing machine and the ratio of the peak light intensity of the optical image to a reference value.

[0036] Figure 7 This is a graph showing the relationship between the processing speed and the height of the dross in the laser processing machine.

[0037] Figure 8 It is a graph showing the relationship between the focal position of the laser in the laser processing machine and the size of the optical image.

[0038] Figure 9 It is a graph showing the relationship between the focal position of the laser and the peak intensity of the light in the laser processing machine.

[0039] Figure 10 This is a graph showing the relationship between the focal position of the laser and the height of the slag in the laser processing machine.

[0040] Figure 11 It is a graph showing the relationship between the size of the optical image, the peak light intensity, and the quality of the result of laser processing by the laser processing machine.

[0041] Figure 12 It is a graph showing the relationship between the size of the optical image, the peak light intensity, and the quality of the result of laser processing by the laser processing machine.

[0042] Figure 13 It is a graph showing the relationship between the size of the optical image, the peak light intensity, and the quality of the result of laser processing by the laser processing machine.

[0043] Figure 14 This is a graph showing the relationship between the workpiece thickness and the laser focal point position under the initial processing conditions of the laser processing machine.

[0044] Figure 15 It is a graph showing the relationship between the workpiece thickness and the focal position of the laser from the center of the workpiece under the initial processing conditions of the laser processing machine.

[0045] Figure 16 These are tables and graphs used to conceptually illustrate the control range that can be set based on the relationship between the size of the optical image, the peak light intensity, and the quality of the result of laser processing by the laser processing machine.

[0046] Figure 17 It is Figure 11 Data applied to Figure 16 Tables and charts are used to represent the content of a document.

[0047] Figure 18 This is a flowchart illustrating an example of the laser processing procedure of the laser processing machine.

[0048] Figure 19 This is a diagram used to illustrate an example of the relationship between the optical image of the machine learning used to explain the laser processing machine and the focal position of the laser and the processing speed (cutting speed).

[0049] Figure 20 It is used for Figure 19 The figure illustrates an example of the parameters of the fifth optical image.

[0050] Figure 21 It is used for Figure 19 The figure illustrates an example of the parameters of the first optical image.

[0051] Figure 22 It is used for Figure 19 The figure illustrates an example of the parameters of the sixth optical image.

[0052] Figure 23 It is used for Figure 19 The figure illustrates an example of the parameters of the seventh optical image.

[0053] Figure 24 It is used for Figure 19 The figure illustrates an example of the parameters of the fourth optical image.

[0054] Figure 25 This is a block diagram that schematically illustrates the functional structure of a laser processing machine according to other embodiments of the present invention. Detailed Implementation

[0055] Hereinafter, with reference to the accompanying drawings, a laser processing machine and processing method according to embodiments of the present invention will be described in detail. However, the following embodiments do not limit the invention for which patent protection is claimed, and all combinations of the features described in the embodiments are not necessary for the solution of the invention.

[0056] Figure 1 This is an explanatory diagram showing a schematic structure of a laser processing machine 100 according to one embodiment of the present invention. Figure 2 This is a block diagram that roughly represents the functional structure of the laser processing machine 100. Furthermore, since the basic structure of the laser processing machine 100, which includes the laser processing unit 1, is known, only a general description will be given here, except for the parts that need to be explained.

[0057] Furthermore, in the following description, "X-axis direction" refers to the left-right direction when facing the front of the processing table 30 of the laser processing unit 1 in the laser processing machine 100, "Y-axis direction" refers to the depth direction in this case, and "Z-axis direction" refers to the up-down direction in this case. In addition, in this embodiment, there are cases where the scale and size of each component are exaggerated, and some components are omitted.

[0058] like Figure 1 As shown, the laser processing machine 100 is a processing machine that processes a workpiece (material) W using a laser L (laser cutting processing). The workpiece W, which is the object of processing, is, for example, a metal sheet. The laser processing machine 100 includes: a laser processing unit 1, which includes a laser oscillator 10, a laser processing head 20, and a processing table 30 on which the workpiece W is placed; and a camera 40, which serves as an imaging device, to photograph the workpiece W irradiated by the laser L.

[0059] Furthermore, the laser processing machine 100 includes a NC device 50 for controlling the laser processing unit 1 according to the processing conditions for processing the workpiece W, and an auxiliary gas supply device (not shown) for supplying auxiliary gas. Specifically, the NC device 50 functions as the NC device of the laser processing machine 100. Additionally, processing conditions are preset in the NC device 50 according to the material and thickness of the workpiece W.

[0060] Laser processing unit 1 is a unit used to actually process workpiece W using laser L. The laser oscillator 10 of laser processing unit 1 is connected to laser processing head 20 via process fiber 11.

[0061] The laser oscillator 10 generates and emits a laser L. For example, the laser oscillator 10 is preferably a type that uses seed light emitted from a laser diode to amplify Yb or the like via a resonator to emit a laser L of a predetermined wavelength, or it can directly utilize the laser L emitted from a laser diode.

[0062] Laser oscillators 10 include, for example, solid-state laser oscillators such as fiber laser oscillators, YAG laser oscillators, disk laser oscillators, and DDL oscillators.

[0063] In this embodiment, the laser oscillator 10 emits a 1μm laser L with a wavelength of 900nm to 1100nm. For example, a DDL oscillator emits a laser L with a wavelength of 910nm to 950nm, and a fiber laser oscillator emits a laser L with a wavelength of 1060nm to 1080nm. Additionally, a blue semiconductor laser emits a laser with a wavelength of 400nm to 460nm. The green laser can be a fiber laser oscillator or a DDL oscillator that emits a laser with a wavelength of 500nm to 540nm, or it can be a multi-wavelength resonator that performs optical synthesis with the 1μm laser L. The process fiber 11 transmits the laser L emitted by the laser oscillator 10 to the laser processing head 20 of the laser processing unit 1.

[0064] The laser processing head 20 irradiates the workpiece W on the processing table 30 with a laser L transmitted by the process fiber 11. The laser processing head 20 has a cylindrical housing 20a containing the irradiation center axis C of the laser L. Inside the housing 20a, the laser processing head 20 has: a collimating lens 21, which receives the laser L emitted from the exit end of the process fiber 11; and a bend mirror 22, which reflects the laser L emitted from the collimating lens 21 downwards in the Z-axis direction, perpendicular to the X and Y axes. The bend mirror 22 is coated, for example, to reflect only a portion of the wavelength of the laser L (1080 nm, 650 nm). Additionally, the laser processing head 20 has a processing focusing lens 23 that converges the laser L reflected by the bend mirror 22.

[0065] The housing 20a is formed into a pointed shape at the front end of the laser processing head 20. A nozzle 20b with a circular opening is provided at the front end of the laser processing head 20 for irradiating the workpiece W with laser L. In order to remove the molten workpiece W, the nozzle 20b has a nozzle function for making the high-pressure gas flow supplied from the auxiliary gas supply device coaxial with the laser L and directed towards the workpiece W, and is configured to be easily installed and removed.

[0066] The laser processing unit 1 has a laser processing head 20 configured such that it can move relative to the processing table 30 in the X-axis, Y-axis and Z-axis directions on a processing table 30 connected via a carriage (not shown).

[0067] In the laser processing unit 1 configured in this way, a laser L transmitted by the process fiber 11 is used to perform, for example, cutting or piercing of the workpiece W.

[0068] The light LW from the workpiece W includes various types of light, such as reflected light from the laser L and plasma light generated from the workpiece W. When a through hole is formed on the workpiece W by the laser L, the reflected light from the workpiece W decreases. The optical image OI (O1) generated in the processing area of ​​the workpiece W by these light LWs is focused by the processing condenser lens 23 and the bending mirror 22, and then captured by the camera 40.

[0069] The camera 40 is configured to acquire, for example, a stream of captured images (image information) obtained by spatial decomposition. The camera 40 may be a color camera, a monochrome camera, a high-speed camera, etc. The stream of images captured by the camera 40 is input to the NC device 50 connected via a data link (cable) 41.

[0070] The NC device 50 controls the operation of the laser processing unit 1 so that the detected values ​​representing the optical image OI captured by the camera 40, such as the size of the optical image OI (OI Size) and the peak value of the light intensity of the optical image OI (LI), are close to the reference values ​​preset to the NC device 50.

[0071] like Figure 2 As shown, the NC device 50 functionally includes an image processing unit 53, a control unit 54, a display unit 52, an input unit 55, and a storage unit 51. The image processing unit 53 analyzes the image information of the optical image OI input from the camera 40 via the cable 41 and the image interface (I / F) 2, and calculates the detection values ​​of parameters such as the size OIS of the optical image OI (hereinafter referred to as "size OIS" unless otherwise specified) and the peak PV of the light intensity L1 of the optical image OI (hereinafter referred to as "peak PV" unless otherwise specified).

[0072] Furthermore, the control unit 54 operates the laser processing unit 1 in a manner that brings the detection value calculated by the image processing unit 53 close to the reference value stored in the storage unit 51. The control unit 54 can also control the operation of the laser processing unit 1 based, for example, on the size of the optical image OI (OIS) and the peak value of the light intensity L (PV) contained in the detection value, so that the focal point Fp of the laser L and the feed rate Fr of the laser L relative to the workpiece W are close to the preset reference conditions for the focal point Fp and feed rate Fr. The display unit 52 displays various screens, such as a setting input screen for inputting processing conditions. The input unit 55 is composed of input devices such as a keyboard and a mouse.

[0073] The storage unit 51 has storage media such as RAM, ROM, HDD, and SSD, and is connected to a database 51a that associates and stores various types of information. In addition, the storage unit 51 stores, for example, information related to the determination of whether the processing is good or bad by the control unit 54, information related to the optical image OI, the set processing conditions 51c, and the detection values ​​of the calculated parameters of the optical image OI in the database 51a.

[0074] Furthermore, database 51a stores a machining program 51b that records machining conditions 51c, such as the focal position Fp of laser L and the cutting speed (machining speed) Fr. Database 51a also stores an evaluation table 51d corresponding to machining conditions 51c, obtained by performing machining under initial machining conditions. Evaluation table 51d includes reference values ​​for dimensions OIS and peak PV, etc.

[0075] That is, when controlling the operation of the laser processing unit 1, the control unit 54, by referring to the evaluation table 51d, can instantly calculate, for example, the degree of difference between the real-time obtained size OIS and peak PV and the reference values ​​of size OIS and peak PV contained in the evaluation table 51d. Furthermore, it controls the operation of the laser processing unit 1 (e.g., feedback control) based on the focal position Fp and cutting speed Fr of the laser L from the laser processing head 20 during laser processing based on the calculation results, so that, for example, the detected values ​​of the parameters are consistent with (close to) the reference values.

[0076] The display unit 52 can be configured as a touch panel that also functions as an input unit 55. In this case, when the display unit 52 is configured as a touch panel, the user can input various information to the NC device 50, including the material and thickness of the workpiece W, by operating the display unit 52. Furthermore, the user can visually recognize the various information displayed on the display unit 52 to understand information related to laser processing, such as the processing conditions 51c.

[0077] The image processing unit 53 can be composed of a graphics controller, a buffer memory such as VRAM, a display control IC, etc., but in this example, it is composed of an image processing device with at least a GPU. The control unit 54 is composed of an arithmetic processing device with a CPU. Alternatively, the image processing unit 53 and the control unit 54 can also be composed of a functionally unified arithmetic processing device.

[0078] Figure 3 This diagram illustrates an example of parameters for observing (detecting) an optical image OI based on image information captured by a camera 40 of a workpiece W. As shown in the diagram, the image processing unit 53 performs real-time processing, such as analysis, on the optical image OI containing laser L and plasma light captured by the camera 40. As parameters representing the optical image OI detected by the image processing unit 53, for example, the size OIS of the optical image OI, representing the length of the optical image region 9 in the direction of travel of the laser L, is detected from the optical image OI captured by the camera 40. For example, after performing contour detection of the optical image OI, the length of the contour in the direction of travel of the laser L is detected to determine the size OIS. Alternatively, the light intensity L1 level of the image surrounding the optical image region 9 can be used as a threshold level to divide the image information into a multi-stage light intensity distribution, and the size OIS can be determined by observing the length of the optical image OI in the direction of travel of the obtained light intensity distribution image.

[0079] Furthermore, for example, from the resolved image 8 obtained by resolving the light intensity LI in the direction perpendicular to the aforementioned travel direction of the optical image OI, the peak value PV of the light intensity LI of the optical image OI is detected as a parameter. These detected values ​​of the size OIS and the peak value PV are input to the control unit 54 and stored in the storage unit 51 for controlling the operation of the laser processing unit 1. A detailed description of the control of the operation of the laser processing unit 1 using the size OIS and the peak value PV will be given later.

[0080] The control unit 54 sets the processing conditions 51c of the laser processing unit 1 based on input information, such as input from the user via the input unit 55 and the input interface (I / F) 3. Additionally, the control unit 54 outputs control signals to the laser processing unit 1 via the output interface (I / F) 4 to control the operation of the laser processing unit 1.

[0081] Specifically, during laser processing, the control unit 54 reads the processing program 51b from the storage unit 51, and reads the reference values ​​set (substituted) in the evaluation table 51d according to the material and plate thickness of the workpiece W to be processed, as well as the processing conditions 51c recorded in the processing program 51b. In addition, the control unit 54 obtains and refers to the detection values ​​of the dimension OIS and peak PV after analysis by the image processing unit 53.

[0082] Furthermore, the control unit 54 controls the operation of the laser processing unit 1 (laser oscillator 10 and laser processing head 20) based on the read processing program 51b, reference values, and processing conditions 51c. Thus, in the laser processing unit 1, the workpiece W is laser-processed according to processing conditions 51c.

[0083] As described above, database 51a stores the reference values ​​and processing conditions 51c for cutting workpiece W. Processing conditions 51c include, in addition to information on the focal position Fp of laser L and the cutting speed (processing speed) Fr when cutting workpiece W using laser L, information on the laser output of laser oscillator 10, pulse conditions such as the frequency and duty cycle of laser L, the opening diameter of nozzle 20b of laser processing head 20, the focal length of processing focusing lens 23, and the type and pressure of auxiliary gas. Furthermore, the focal position Fp of laser L refers to the distance between the upper surface (surface) of workpiece W in the Z-axis direction (vertical direction (thickness direction of workpiece W)) and the focal position Fp, i.e., the position of the processing focus.

[0084] Alternatively, each I / F2 to 4 can be composed of a unified I / F with communication capabilities. In this case, a structure can be adopted in which predetermined data generated by an external computer or the like is input and output to the NC device 50 via communication through the unified I / F. In addition, the storage unit 51 can, for example, store in the database 51a the image information of the laser processing quality determination result and the optical image OI obtained by the camera 40 of the workpiece W, along with the reference value, the set processing conditions 51c, and the aforementioned parameters.

[0085] As described above, the laser processing head 20 is fixed to a slide that is movable in the Y-axis direction on the processing table 30, and the slide is also provided on a slide that is movable in the X-axis direction. Therefore, the laser processing head 20 is configured to allow the processing position of irradiating the workpiece W with laser L to move along the surface of the workpiece W in both the X-axis and Y-axis directions.

[0086] Furthermore, instead of the aforementioned structure that moves the laser processing head 20 along the surface of the workpiece W, the laser processing machine 100 can be a structure that moves the workpiece W in the X-axis and Y-axis directions while the position of the laser processing head 20 is fixed. In other words, the laser processing machine 100 only needs to have a structure that allows the laser processing head 20 to move relative to the surface of the workpiece W. If a laser processing machine 100 configured in this way is used, the laser L emitted from the laser oscillator 10 can be used to perform processes such as cutting, penetration (hole opening, punching), quenching, and welding on the workpiece W on the processing table 30, producing products with predetermined shapes, patterns, etc.

[0087] Additionally, an auxiliary gas supply device (not shown) adjusts the type, pressure, and flow rate of the auxiliary gas to supply it to the laser processing head 20. Examples of auxiliary gases include oxygen, nitrogen, a mixture of oxygen and nitrogen, or air. During laser processing, the auxiliary gas is blown onto the workpiece W through the opening of the nozzle 20b. The blown auxiliary gas causes molten metal within the molten cut width of the workpiece W to be expelled.

[0088] Next, the operation of the laser processing machine 100 will be explained.

[0089] In the laser processing machine 100 configured in this way, for example, using 10mm thick stainless steel (SUS304) as the workpiece W, the output of the laser L of the laser oscillator 10 is set to 9kW, and in laser processing using nitrogen as the auxiliary gas, the processing condition 51c is set to achieve optimal processing, for example, when the focal position Fp of the laser L is -4 and the processing speed Fr is F4500 (referred to as "reference condition 60"). Furthermore, the processing condition 51c is set as a control range 61, with the focal position Fp and processing speed Fr falling within a predetermined range centered on this reference condition 60.

[0090] Furthermore, this range is used as the control range 61 to ensure that even if the focal position Fp deviates slightly, it will not result in poor cutting, and the stability and productivity will not be drastically reduced by the processing speed Fr. Moreover, while fixing various other conditions in the processing conditions 51c (duty cycle of the laser L, air pressure, etc.), laser processing is performed while changing the focal position Fp and the processing speed (cutting speed) Fr. The relationship profile between the focal position Fp and the processing speed (cutting speed) Fr of the optical image OI captured by the camera 40 each time is configured as follows.

[0091] Figure 4 This is a graph illustrating an example of the relationship between the optical image OI, the focal position Fp of the laser L, and the processing speed (cutting speed) Fr under processing conditions 51c of the laser processing machine 100, after analysis by the image processing unit 53, etc. The vertical axis of the graph represents the focal position Fp of the laser L, and the horizontal axis represents the cutting speed Fr during laser processing. Furthermore, the direction from left to right when facing the figure is the travel direction of the laser L.

[0092] Figure 4 The diagram shows an example illustrating the relationship between the optical image OI, focal position Fp, and cutting speed Fr in laser processing under the aforementioned processing condition 51c. Furthermore, in... Figure 4 In the diagram, the ranges enclosed by single-dash lines, double-dash lines, thin dashed lines, and thick dashed lines respectively represent the same range (area).

[0093] exist Figure 4 In the reference condition 60, the control range 61, including the first optical image OIa captured by the camera 40, is a range encompassing the combination of the focal position Fp and the cutting speed Fr, where the workpiece W has undergone good laser processing with almost no slag formation. Furthermore, the second range 62, including the second optical image OIb, is a range encompassing the combination of the focal position Fp and the cutting speed Fr, where, compared to the control range 61, the workpiece W has slightly more slag formation but has undergone laser processing to a certain extent.

[0094] Furthermore, the third range 63, including the third optical image OIc, is a range that includes the combination of the focal position Fp and the cutting speed Fr in cases where cutting is possible but slag is considered to be generated. The fourth range 64, including the fourth optical image OId, is a range that includes the combination of the focal position Fp and the cutting speed Fr in cases where cutting is considered to be poor (gouging). Additionally, slag refers to a substance formed by the accumulation of molten metal, oxides, etc., adhering to the lower surface of the cut material, and is synonymous with slag. Furthermore, when determining whether slag is generated, the allowable value of the slag height Dh (Dross height) from the workpiece W's plate surface can be set to, for example, 10% or less, or 5% or less, of the workpiece W's plate thickness. Additionally, gouging in laser cutting refers to a state where, for example, molten metal is ejected onto the material surface (workpiece surface) during laser cutting when the laser L does not penetrate, resulting in a dirty appearance.

[0095] Specifically, such as Figure 4 As shown, the control range 61 includes a combination of the focal position Fp of the laser L being -3 to -5, and a combination of the cutting speed Fr being F4000 (4000 mm / min, the same below) to F5000 (5000 mm / min, the same below), represented by a rectangle. If the operation of the laser processing unit 1 is controlled so that the focal position Fp and the processing speed Fr converge within this control range 61, and more preferably in a manner close to the reference values, then laser processing with the desired quality can be performed. The second range 62 includes combinations of focal position Fp being -2 and cutting speed Fr being F4000 and F4500 (4500 mm / min, the same below), combinations of focal position Fp being -4 and -5 and cutting speed Fr being F3000 (3000 mm / min, the same below), combinations of focal position Fp being -6 and -7 and cutting speed Fr being F2000 (2000 mm / min, the same below) to F4500, and combinations of focal position Fp being -8 and cutting speed Fr being F2000 to F4000.

[0096] In addition, the third range 63 includes combinations of focal position Fp being 0 and cutting speed Fr being F1000 (1000 mm / min, the same below) to F4000, combinations of focal position Fp being -1 and cutting speed Fr being F1000 to F4500, combinations of focal position Fp being -2 and cutting speed Fr being F1000 to F3000, combinations of focal position Fp being -3 and -4 and cutting speed Fr being F1000 to F2000, and combinations of focal position Fp being -5 to -8 and cutting speed Fr being F1000.

[0097] Furthermore, the fourth range 64 includes the following: when the focal position Fp is 0 and the cutting speed Fr is F4500; the combination of focal positions Fp being -1 and -2 and the cutting speed Fr being F5000; the combination of focal positions Fp being -2 to -5 and the cutting speed Fr being F5500 (5500 mm / min, the same below); the focal position Fp being -6 and the cutting speed Fr being F5000; and the focal position Fp being -8 and the cutting speed Fr being F4500.

[0098] As can be seen from the above, according to the applicant's understanding, based on the relationship between the focal position Fp and the processing speed Fr contained in the various ranges 61 to 64, the size OIS and the peak value PV of the optical image OI (first optical image OIa) under the reference condition 60 (focal position Fp is -4 and cutting speed Fr is F4500) located in the center of the control range 61 can become the reference values ​​stored in the evaluation table 51d. Therefore, if the control range 61 containing the reference condition 60 is set as the processing condition 51c in advance according to the material and thickness of the workpiece W, the possibility of achieving appropriate processing actions at the initial operation can be increased. Furthermore, after the processing action begins, the operation (focal position Fp and processing speed Fr) of the laser processing unit 1 can be controlled as long as the actually observed optical image OI is close to the reference value. Here, as an examination related to the reference value, the case focusing on the processing speed Fr will be explained.

[0099] Figure 5 It shows the basis Figure 4 The graph shows the relationship between the laser processing speed Fr of the laser processing machine 100 and the size of the optical image OI (OIS) relative to a reference value. The vertical axis of the graph represents the ratio of the size OIS to the reference value, and the horizontal axis represents the processing speed Fr. According to... Figure 5The following trend can be observed: as the machining speed Fr increases substantially (e.g., from F2000 to F5000), the dimension OIS in the travel direction increases (from approximately 0.98 times to approximately 1.04 times). Furthermore, regarding cases where the machining speed Fr is too high, resulting in poor cut-off (e.g., when the machining speed Fr is faster than F5000), the dimension OIS increases further, but this is from the reference... Figure 4 The situation is also clear when, for example, the cutting speed Fr is F5000 and the focal position Fp is in the range of -1 to -2 and -6, the same planing occurs. That is, in these planing cases, before the cutting groove is completed and before cutting, the entire laser L irradiated along with the auxiliary gas jet is diffusely reflected through the molten pool of the workpiece W (a state in which the reflected light of the laser L increases sharply due to poor cutting), therefore, as Figure 5 As shown, this illustrates the case where the magnification of the size OIS increases dramatically (becomes larger).

[0100] Figure 6 It shows the basis Figure 4 The graph shows the relationship between the processing speed Fr of the laser processing machine 100 and the ratio of the peak PV of the optical image OI's light intensity LI to a reference value. The vertical axis of the graph represents the ratio of the peak PV to the reference value, and the horizontal axis represents the processing speed Fr. According to... Figure 6 The following tendency can be observed: the faster the machining speed Fr (e.g., from F2000 to F5000), the higher the peak PV (from approximately 0.68 times to approximately 1.09 times). Furthermore, when a poor cut-off occurs due to an excessively high machining speed Fr (e.g., when the machining speed Fr is faster than F5000), the peak PV becomes even higher, but this is from the reference... Figure 4 In cases where, for example, planing occurs as described above when the cutting speed Fr is F5000 and the focal position Fp is in the range of -1 to -2 and -6, the increase in peak PV is also evident. Furthermore, due to planing, compared to the displacement when the cutting speed Fr is from F2000 to F5000, the peak PV shows a significant tendency to increase when the cutting speed Fr is above F5000. Additionally, a roughly linear slope can be confirmed within the range of cutting speed Fr from F2000 to F4000, and the slope displacement within the range of F4000 to F5000 is a slightly smaller slope. Thus, in Figure 6 The diagram shows a sharp increase in the reflected light of laser L due to poor cutting, compared to... Figure 5 Similarly, for the OIS magnification shown, the peak PV magnification increases sharply (becomes larger).

[0101] Figure 7 It shows the basis Figure 4The graph shows the relationship between the processing speed Fr (mm / min) and the slag height Dh (μm) in the laser processing machine 100. The vertical axis represents the slag height Dh, and the horizontal axis represents the processing speed Fr. According to... Figure 7 It can be observed that within a roughly predetermined processing speed range Fr (e.g., F3000 to F5000), the scum height Dh is very low (e.g., less than 100 μm) and is well cut off. Furthermore, it is known that from a low speed to a fixed processing speed Fr (e.g., F3000), the scum height Dh becomes very high (e.g., 500 μm or more). Additionally, it can be confirmed that the processing speed Fr from F3000 to F4500 is approximately linear, showing a different tendency than that from the range from F4500 to F5000. Moreover, at high speeds (e.g., F5000 and above), planing occurs, making cutting impossible, and the scum height Dh cannot be measured.

[0102] Based on the above analysis, for example, when cutting a workpiece W made of SUS304 with a thickness of 10mm using a cutting speed of -3 to -5 at the focal position Fp, if the operation of the laser processing unit 1 is controlled with a cutting speed Fr of a combination of F4000 to F5000 (the cutting speed Fr that satisfies the control range 61 mentioned above), the desired cutting result can be obtained. Furthermore, if the cutting speed Fr is controlled at F4500 (the cutting speed Fr under reference condition 60), an even better cutting result can be obtained. According to this viewpoint, for example, if the recommended cutting speed Fr for the user of the laser processing machine 100 (i.e., the cutting speed Fr under reference condition 60) is determined to be F4500, good laser processing can be performed even if the cutting speed Fr varies to some extent within the control range 61. When considering this as a generalization and universality, it is understood that, for example, the cutting speed Fr of the laser processing head 20 has a certain proportional relationship with the size OIS of the optical image OI. Furthermore, it is known that, for example, the cutting speed Fr of the laser processing head 20 and the peak PV of the light intensity LI of the optical image OI also have a certain proportional relationship. Therefore, if the processing speed Fr of the laser processing unit 1 is controlled within, for example, the control range 61 based on the size OIS and peak PV under reference condition 60, so that the size OIS and peak PV detected based on the image information obtained from the workpiece W captured by the camera 40 are close to the reference values, then the desired laser processing quality, which is close to the optimal condition where no cutting defects occur, can be performed.

[0103] On the other hand, as another consideration related to a different reference value than that for the case of focusing on the processing speed Fr as described above, we will explain the case of focusing on the focal position Fp. Figure 8 It shows the basis Figure 4 The relationship between the focal position Fp of the laser L in the laser processing machine 100 and the size OIS of the optical image OI is shown. According to... Figure 8 The following tendency can be observed: when the focal position Fp is approximately reduced (e.g., from -1 to -7), the size OIS decreases (from approximately 1.35 times to approximately 0.83 times). However, when the focal position Fp is reduced from -7 to -8, contrary to this tendency, the size OIS increases from approximately 0.8 times to approximately 1.2 times, but this is from the reference... Figure 4 The situation is also evident when planing occurs, for example, at a machining speed Fr of F4500 and a focal position Fp of -8. That is, in this case, before cutting through the cut-off groove, all the laser L irradiated along with the auxiliary gas jet is diffusely reflected by the molten pool of the workpiece W, thus showing a sharp increase in the dimension OIS. Similarly, it is evident that planing also occurs when the focal position Fp is increased from -1 to 0, showing a sharp increase in the dimension OIS.

[0104] Figure 9 It shows the basis Figure 4 The relationship between the focal position Fp of the laser L in the laser processing machine 100 and the peak value PV of the light intensity LI of the optical image OI is shown. According to... Figure 9 The following tendency was observed: when the focal position Fp was approximately decreased (e.g., from -2 to -7), the peak PV increased (from approximately 0.76 times to approximately 1.6 times). However, contrary to this tendency, when the focal position Fp was increased from -2 to -1, the peak PV increased from approximately 0.76 times to 2.0 times, but this was compared to the reference value. Figure 4 In this case, it is clear that the scum height Dh is high when the processing speed Fr is F4500 and the focal position Fp is -1. That is, in this case, the peak PV increases depending on the scum adhesion. Furthermore, when the focal position Fp is increased from -1 to 0, planing also occurs, so the peak PV tends to be higher compared to the displacement condition when the focal position Fp is from -2 to -7. Additionally, a roughly linear slope can be confirmed within the range of focal position Fp from -2 to -5, and the slope displacement within the range of -5 to -7 is confirmed to be a slightly larger slope.

[0105] Furthermore, when the focal position Fp is 0, etc., when the focal position Fp is high, the melting state on the upper surface (surface) side of the workpiece W becomes good. On the other hand, the power density on the lower surface (back side) side of the workpiece W decreases, so the melting state cannot be maintained well. In this case, poor slag formation occurs, resulting in planing before cutting. Conversely, when the focal position Fp is -8, etc., when the focal position Fp is low, the power density on the upper surface side of the workpiece W decreases, so the melting state cannot be maintained well. In this case, planing also occurs before cutting.

[0106] Figure 10 It shows the basis Figure 4 The graph shows the relationship between the focal position Fp (mm) of the laser L in the laser processing machine 100 and the scum height Dh (μm). The vertical axis of the graph represents the scum height Dh, and the horizontal axis represents the focal position Fp. According to... Figure 10 It can be determined that within a roughly predetermined focal position Fp range (e.g., the range of -2 to -7), the scum height Dh is very low (e.g., less than 100 μm) and is well cut off. Furthermore, it is known that in other focal position Fp ranges (e.g., very shallow or deep focal positions (e.g., focal positions of -1 or -8)), the scum height Dh becomes very high (e.g., above 500 μm). Additionally, it can be confirmed that the focal position Fp is approximately linear within the range of -3 to -5, and that the focal position Fp exhibits a different tendency than the ranges of -2 to -3 or -5 to -7.

[0107] As clarified above, for example, when cutting a workpiece W made of SUS304 with a thickness of 10mm using F4500 as the processing speed Fr, if the operation of the laser processing unit 1 is controlled in a manner where the focal position Fp is set to a combination of -2 to -7, the slag height Dh is within the allowable range. Furthermore, if the focal position Fp is set to a combination of -3 to -5 (to cut at the focal position Fp that satisfies the aforementioned control range 61), a better cutting result is obtained. If the focal position Fp is set to -4 (the focal position Fp under reference condition 60), the best (optimal) cutting result is obtained. From this perspective, for example, if the recommended focal position Fp for the user of the laser processing machine 100 (i.e., the focal position Fp under reference condition 60) is determined to be -4, good laser processing can be performed even if the focal position Fp varies to some extent within the control range 61. When capturing such content as a generalized and universal tendency, it can be seen that, for example, the focal position Fp of the laser processing head 20 has a certain proportional relationship with the size OIS of the optical image OI, but the focal position Fp of the laser processing head 20 has a certain inverse proportional relationship with the peak value PV of the light intensity LI of the optical image OI.

[0108] Therefore, in the control unit 54, if the focal position Fp of the laser processing unit 1 is controlled within, for example, the control range 61 based on the dimension OIS and peak PV under the reference condition 60, so that the dimension OIS and peak PV detected based on the image information obtained from the workpiece W captured by the camera 40 are close to the reference value, then the desired laser processing quality, which is close to the optimal condition where no cutting defects occur, can be performed. Furthermore, the control unit 54 compares, for example, the detected values ​​of dimension OIS and peak PV obtained by the image processing unit 53 with the reference value, thereby immediately calculating the difference (deviation) between the detected value and the reference value. And, the focal position Fp and processing speed (cutting speed) Fr in the processing condition 51c are adjusted so that the deviation, for example, converges within the control range 61, or the deviation is eliminated, that is, the detected value is brought close to the reference value, thereby correcting the processing condition 51c (focal position Fp and processing speed Fr) stored in the storage unit 51. For example, the adjustment of the focal position Fp can be performed by adjusting the collimating lens 21 or the processing condenser lens 23.

[0109] Figure 11 , Figure 12 as well as Figure 13 The relationship between the size OIS of the optical image OI produced by the laser processing machine 100, the peak PV of the light intensity LI of the optical image OI, and the result of the quality judgment (hereinafter referred to as "quality result") is shown. The vertical axis of each figure represents the peak PV, and the horizontal axis represents the size OIS. Furthermore, in... Figures 11-13 In the diagram, “◇” indicates the position of dimensional OIS and peak PV under baseline condition 60, and “○” indicates the position of dimensional OIS and peak PV when both machining speed Fr and product quality are good. Additionally, “●” indicates the position of dimensional OIS and peak PV under conditions where product quality is good but may become a machining defect, or where machining speed Fr is slow and may become inappropriate; “▲” indicates the position of dimensional OIS and peak PV when workpiece W has slag attached; and “×” indicates the position of dimensional OIS and peak PV under machining defects.

[0110] Figure 11 The diagram shows the distribution of dimensional OIS, peak PV, and quality results in laser processing when a 10mm thick stainless steel (SUS304) workpiece W is irradiated with a 9kW output laser L at a focal position Fp of -4 and a processing speed Fr of F4500, under the baseline condition 60, with appropriate changes to the processing conditions. According to... Figure 11As shown, the control range 61, which includes the reference condition 60, is defined as a range of approximately 0.9 to approximately 1.1 times the reference condition 60, and approximately 0.75 to approximately 1.25 times the reference condition 60, which is a generally good reference for both the size OIS and peak PV being 1.0. Therefore, for example, if the size OIS and peak PV detected during laser processing converge within this control range 61, then for the operation of the laser processing unit 1, even if the focal position Fp and / or the processing speed Fr deviate slightly from the reference condition 60, a product with good cutting quality can be obtained. At the same time, if the detected size OIS and peak PV are the same as the reference values ​​stored in the evaluation table 51d, it can be said that laser processing can be performed at what is considered the optimal focal position Fp and / or processing speed Fr.

[0111] exist Figure 12 The diagram shows the material of the workpiece W, the output of the laser L, etc., and their relationship with... Figure 11 Under the same conditions, only the thickness of workpiece W is changed to 6mm. The distribution of dimensional OIS, peak PV, and quality results in laser processing is observed when the processing conditions are appropriately altered. According to... Figure 12 As shown, the control range 61, which includes the reference condition 60, is defined as a generally good reference relative to the reference condition 60 where both the size OIS and peak PV are 1.0. This range is approximately 0.85 to 1.1 times the size OIS and approximately 0.5 to 1.25 times the peak PV. Therefore, if the size OIS and peak PV, as detected above, converge within the control range 61, then even if the focal position Fp and / or processing speed Fr deviate slightly from the reference condition 60, it can be said that laser processing can be performed with what is considered to be excellent cutting quality and optimal focal position Fp and / or processing speed Fr to obtain a product.

[0112] exist Figure 13 The diagram shows the material of the workpiece W, the output of the laser L, etc., and their relationship with... Figure 11 as well as Figure 12 Under the same conditions, only the thickness of workpiece W is changed to 15mm. The distribution of dimensional OIS, peak PV, and quality results in laser processing is observed when the processing conditions are appropriately altered. According to... Figure 13As shown, the control range 61, including the reference condition 60, is defined as a generally good reference relative to the reference condition 60 where both the size OIS and peak PV are 1.0. This range is approximately 0.95 to 1.1 times the size OIS and approximately 0.8 to 1.1 times the peak PV. Therefore, if the size OIS and peak PV, as detected above, converge within the control range 61, then even if the focal position Fp and / or processing speed Fr deviate slightly from the reference condition 60, it can be said that laser processing can be performed with what is considered to be excellent cutting quality and optimal focal position Fp and / or processing speed Fr to obtain a product.

[0113] Based on the above results, even with workpieces of arbitrary thickness W (10mm, 6mm, and 15mm), as a basic trend, regarding the processing speed (cutting speed) Fr, it is assumed that when the processing speed Fr is high, the peak PV increases corresponding to the length of the front end portion before cutting. Furthermore, it is assumed that when the processing speed Fr is slow, the peak PV decreases corresponding to the increase in the angle before cutting. Additionally, it is assumed that when the processing speed Fr is high, the dimension OIS increases (becomes longer) corresponding to the length of the front end portion before cutting, and that when the processing speed Fr is slow, the dimension OIS decreases (becomes shorter) corresponding to the increase in the angle before cutting.

[0114] Furthermore, regarding the focal position Fp, it is believed that when the focal position Fp is low (deep), the power density of the laser L decreases on the surface of the workpiece W, but the laser L covers the entire area before cutting, thus easily melting. Therefore, it is assumed that the peak PV becomes higher and the size OIS becomes smaller (shorter). In addition, in the case of poor cutting (planing), the peak PV becomes significantly higher due to saturation, and the size OIS also becomes significantly larger, thus it can be easily excluded from the good / bad judgment.

[0115] Furthermore, in compiling the information to date related to empirical evidence concerning the applicant's laser processing, it was clarified that, based on a certain reference condition 60, if the detected size OIS is approximately 0.9 to 1.1 times larger and the peak PV is approximately 0.8 to 1.2 times larger (control range 61) relative to the size OIS and peak PV of the reference condition 60, then laser processing under good processing conditions 51c is possible, and if it is the same as the reference value, then laser processing under optimal processing conditions 51c is possible. Therefore, in the laser processing machine 100 of this embodiment, based on the image information of the optical image OI obtained by the camera 40 capturing the workpiece W, and using the detected values ​​of size OIS and peak PV as parameters, the operation of the laser processing unit 1 (processing speed Fr and / or focal position Fp) can be controlled so that the size OIS and peak PV in the laser processing of the workpiece W are close to the size and peak of the aforementioned reference condition 60, and, for example, converge within the control range 61 if they deviate from it.

[0116] Figure 14 This is a graph showing the relationship between the workpiece W's thickness and the laser focal point Fp of the laser L under the initial processing conditions of laser processing machine 100. Additionally, Figure 15 This is a graph showing the relationship between the thickness of the workpiece W and the focal position Fp of the laser L originating from the center of the thickness under the initial processing conditions of laser processing by the laser processing machine 100. Furthermore, the material of the workpiece W is the same as described above: stainless steel (SUS304).

[0117] like Figure 14 As shown, as initial processing conditions, for example, when the thickness of workpiece W is (1) 1 mm and (2) 3 mm, the initial focal position Fp can be set to 0; when the thickness of workpiece W is (3) 6 mm, the initial focal position Fp can be set to -1; when the thickness of workpiece W is (4) 10 mm, the initial focal position Fp can be set to -4; when the thickness of workpiece W is (5) 15 mm, the initial focal position Fp can be set to -11; and when the thickness of workpiece W is (6) 20 mm, the initial focal position Fp can be set to -16. This becomes the initial processing condition for the focal position Fp. In actual laser processing, laser processing begins from the initial focal position Fp set in this way, but these focal positions Fp can be controlled in real time during laser processing.

[0118] In addition, such as Figure 15As shown, in (1) above, the distance from the focal point Fp of the workpiece W's plate thickness center is 0.5 mm, therefore the proportion of the focal point Fp of the plate thickness center is 50%. In (2) above, the distance from the focal point Fp of the workpiece W's plate thickness center is 1.5 mm, therefore the proportion of the focal point Fp of the plate thickness center is 50%. In (3) above, the distance from the focal point Fp of the workpiece W's plate thickness center is 2.0 mm, therefore the proportion of the focal point Fp of the plate thickness center is 33%. In (4) above, the distance from the focal point Fp of the workpiece W's plate thickness center is 1.0 mm, therefore the proportion of the focal point Fp of the plate thickness center is 10%.

[0119] Furthermore, in (5) above, the distance from the focal point Fp of the workpiece W's plate thickness center is -3.5 mm, therefore the proportion of the focal point Fp from the plate thickness center is -23%. And, in (6) above, the distance from the focal point Fp of the workpiece W's plate thickness center is -6.0 mm, therefore the proportion of the focal point Fp from the plate thickness center is -30%. As described above, according to... Figure 14 as well as Figure 15 It can summarize the relationship between the workpiece W thickness and the focal point position Fp under the initial processing conditions of laser processing machine 100.

[0120] Furthermore, considering the relationship between the thickness of the workpiece W and the focal position Fp of the laser L, a processing condition 51c is set that satisfies a margin (processing allowance, a range that is acceptable even if slightly different from the reference condition 60) between the processing speed Fr and the focal position Fp, as a control range 61 that includes the reference condition 60 that can obtain the best processing results. The operation of the laser processing unit 1 is then controlled accordingly. Here, the ideas related to setting the control range 61 that satisfies the aforementioned margin in laser processing will be explained.

[0121] Figure 16 This is a table used to conceptually explain the control range that can be set according to the relationship between the size OIS of the optical image OI, the peak PV of the light intensity LI, and the quality result of laser processing by the laser processing machine 100. Figure 16 (a) and charts ( Figure 16 (b) Figure 16 (a) For each of the optical image size OIS and the peak value PV of the light intensity LI, for example, the processing speed Fr of the laser processing machine 100 is represented horizontally in the table, and the focal position Fp of the laser L (and the ratio of the focal position Fp to the center of the plate thickness) is represented vertically in the table, indicating the optimal combination of focal position Fp and processing speed Fr for each. Furthermore, Figure 16(b) indicates through Figure 16 The good range shown in (a) illustrates how the control range is represented in the relationship between size OIS and peak PV 61.

[0122] First, such as Figure 16 As shown in (a), when the frame (X5, Y5) with a focal position Fp of -4 and a processing speed Fr of F4500 is taken as the reference condition 60, considering the above-mentioned margin, for example, it is possible to define a good range 61a for the size OIS of the optical image OI containing frames (X1 to X9, Y1 to Y9) with 3 levels in both the horizontal and vertical directions, and a good range 61b for the peak value PV of the light intensity LI.

[0123] And, as Figure 16 As shown in (b), when plotting a graph with the corresponding boxes (X1, Y1, X2, Y2, ..., X9, Y9) in each good range 61a, 61b as points, and the horizontal axis set to size OIS and the vertical axis set to peak PV, the control range 61 of the rectangular shape (rhombus in the illustrated example) of the point (X5, Y5) containing the reference condition 60 in the inner region is determined.

[0124] The control range 61 can be defined by a first line segment 71, a second line segment 72, a third line segment 73, and a fourth line segment 74, each with a predetermined slope. The first line segment 71 represents the relationship between dimensional OIS and peak PV when the machining speed Fr is increased while the focal position Fp is fixed at the upper limit (-3) of the good range 61a, 61b. The second line segment 72 represents the relationship between dimensional OIS and peak PV when the machining speed Fr is increased while the focal position Fp is fixed at the lower limit (-5) of the good range 61a, 61b.

[0125] Furthermore, the third line segment 73 indicates the relationship between dimensional OIS and peak PV when the machining speed Fr is fixed at the upper limit (F2400) of the good range 61a, 61b and the focal position Fp is reduced. The fourth line segment 74 indicates the relationship between dimensional OIS and peak PV when the machining speed Fr is fixed at the lower limit (F2000) of the good range 61a, 61b and the focal position Fp is reduced.

[0126] Thus, by considering the upper and lower limits of the good ranges 61a and 61b, the control range 61 is determined. Therefore, in the laser processing machine 100, the operation of the laser processing unit 1 is controlled so that the point (not shown) representing the relationship between OIS and peak PV detected based on the image information obtained by the camera 40 from the workpiece W is close to the point (X5, Y5) of the reference condition 60 and is included (continuously included) within the control range 61.

[0127] Specifically, the operation of the laser processing unit 1 is controlled by varying at least one of the focal position Fp of the laser L and the processing speed Fr on the workpiece W in a manner that satisfies the control range 61 and approaches the reference condition 60. More specifically, regarding the size OIS of the detected optical image OI, for example, if the detected size OIS is smaller than the size of the reference condition 60, control is performed such as increasing the processing speed Fr and / or raising the focal position Fp. Conversely, for example, if the detected size OIS is larger than the size of the reference condition 60, control is performed such as decreasing the processing speed Fr and / or lowering the focal position Fp.

[0128] Furthermore, regarding the peak PV of the detected optical image OI's light intensity LI, if the detected peak PV is smaller than the peak value of reference condition 60, controls are implemented such as increasing the processing speed Fr and / or decreasing the focal position Fp. Conversely, if, for example, the detected peak PV is larger than the peak value of reference condition 60, controls are implemented such as decreasing the processing speed Fr and / or increasing the focal position Fp.

[0129] Furthermore, when correcting the processing condition 51c, from the perspective of control as described above, the detected size OIS and peak value PV are compared with the size and peak value of the reference condition 60. Based on the size of the detected size OIS and / or the size of the peak value PV, the processing condition 51c is corrected by increasing or decreasing the processing speed Fr and / or moving the focus position Fp up or down so that the processing speed Fr and / or the focus position Fp converge within the control range 61. In this way, laser processing within the control range 61 that can maintain good processing results can be performed.

[0130] Figure 17 It is Figure 11 Data applied to Figure 16 Tables and charts are used to represent their contents. Figure 17 (a) and charts ( Figure 17 (b)). In the context of... Figure 11 Confirmation data related to whether the results are good or bad is applied. Figure 16 At times, such as Figure 17 As shown in (a), at the point of reference condition 60 in each good range 61a, 61b (equivalent to...) Figure 16When X5 and Y5 are represented as "100%", X1 is represented as "109%", X2 as "109%", X3 as "111%", X4 as "99%", X6 as "104%", X7 as "91%", X8 as "92%", and X9 as "96%". On the other hand, Y1 is represented as "81%", Y2 as "86%", Y3 as "94%", Y4 as "94%", Y6 as "107%", Y7 as "114%", Y8 as "115%", and Y9 as "126%".

[0131] Based on this data, the control scope is 61, etc. Figure 17 As shown in (b), although it is a rectangular shape, it is represented by a shape closer to a strip than a rhombus. Figure 17 In the case shown in (b), the point of reference condition 60 is located near the center of control range 61, moving downwards towards the position of the fourth line segment 74. However, even in this case, it can be said that the operation of the laser processing unit 1 can be controlled by varying its processing speed Fr and / or focal position Fp, so that the detected size OIS and / or peak value PV are close to the size and / or peak value of reference condition 60 and converge within control range 61, which is particularly important for good (or optimal) laser processing.

[0132] Thus, according to the laser processing machine 100 of this embodiment, the optical image OI obtained by photographing the workpiece W during laser processing is analyzed to obtain the detected values ​​of the size OIS of the optical image OI and the peak value PV of the light intensity L1 of the optical image OI. The laser processing is performed by controlling the focal position Fp of the laser L and the processing speed (cutting speed) Fr within the control range 61 in a manner that makes the detected size OIS and peak value PV the same as the reference value, for example, so that laser processing always yields a good processing result containing the optimal processing result. Furthermore, the laser processing machine 100 can immediately calculate the deviation from the detected value of the reference value, and, for example, adjust the focal position Fp and the cutting speed Fr to correct the processing condition 51c in a way that eliminates the deviation, thereby controlling the operation of the laser processing unit 1. Therefore, as a result of the laser processing machine 100 irradiating the processing area of ​​the workpiece W with the laser L, the state of the light LW generated from the workpiece W in the processing area can be accurately determined and responded to, and the laser processing can be controlled.

[0133] Furthermore, by utilizing the optical image OI of the workpiece W when irradiated by laser L, the laser processing machine 100 can monitor, for example, the optical image OI obtained by the camera 40 of the workpiece W throughout the entire processing, thereby instantly determining the quality of the laser processing. Moreover, during laser processing, by continuously monitoring the size OIS of the optical image OI obtained from the processing area of ​​the workpiece W and the peak value PV of the light intensity L1 of the optical image OI, laser processing can be performed while fine-tuning the focal position Fp of the laser L and the processing speed (cutting speed) Fr, achieving optimal laser processing.

[0134] Figure 18 This is a flowchart illustrating an example of the laser processing flow of the laser processing machine 100. Furthermore, in Figure 18 In the flowchart, as a prerequisite, the reference value obtained from the pre-processed laser is recorded in the evaluation table 51d. Referring to this evaluation table 51d, the difference between the reference value and the detected value is derived, and the processing speed Fr and / or the focal position Fp are controlled in a manner close to the reference condition 60 containing that reference value. Furthermore, referring to the evaluation table 51d recorded in the database 51a, when a new processing condition 51c is generated, the processing program 51b is rewritten to set the laser processing condition 51c for use, as shown below.

[0135] In addition, unless otherwise specified in this flowchart, the main body of each process's actions, and its relationship with... Figure 2 The processes related to data transmission and reception (exchange) in each part 51 to 54 of each I / F2 to 4 within the NC device 50 shown can be applied using the content already described, so they are omitted.

[0136] like Figure 18 As shown, firstly, the control unit 54 reads the processing program 51b for performing laser processing from the database 51a via the storage unit 51 and starts it (step S101). Next, it reads the processing conditions 51c recorded (included) in the started processing program 51b, and reads the reference values, etc., of the evaluation table 51d corresponding to the processing conditions 51c (step S102).

[0137] Based on the read information, the control unit 54 controls the laser processing unit 1 to irradiate the workpiece W with laser L according to the processing conditions 51c, and begins the processing of the workpiece W (step S103). Then, the camera 40 captures the light LW generated from the workpiece W in the processing area (step S104).

[0138] After the camera 40 takes a picture, the image processing unit 53 analyzes the image information of the optical image OI of the captured light LW (step S105), and calculates and obtains the size OIS of the optical image OI and the detection value of the peak value PV of the light intensity LI of the optical image OI as parameters of the optical image OI (step S106).

[0139] The control unit 54 compares the detected values ​​of the size OIS of the optical image OI and the peak value PV of the light intensity LI of the optical image OI obtained by the image processing unit 53 with the reference values ​​of the read evaluation table 51d, for example, to determine whether there is a difference in the degree of deviation between the two from the control range 61 (step S107). If it is determined that there is no difference in the degree of deviation between the two from the control range 61 ("No" in step S107), processing is performed under processing conditions that converge (stay) within the control range 61 including the reference condition 60. Therefore, the control of the laser processing unit 1 is maintained according to the currently used processing condition 51c, and processing continues (step S114). The process is then transferred to the above step S104, and subsequent processing is repeated.

[0140] On the other hand, if it is determined that there is a difference in the degree of deviation from the control range 61 between the two ("Yes" in step S107), for example, it is determined whether the difference is caused by planing (step S108). If it is determined that planing has occurred ("Yes" in step S108), the control unit 54 determines that processing is being performed under processing conditions that have deviated from the reference condition 60 and deviated from the control range 61, and stops the operation of the laser processing unit 1 to terminate the processing. Then, for the next workpiece W, the processing conditions (e.g., processing speed Fr and focal position Fp) 51c are corrected so that the detection value converges within the control range 61 compared with the reference value (step S109). Then, the control unit 54 records the corrected processing conditions 51c overwritten on the processing program 51b, etc., via the storage unit 51 and stores it in the database 51a (step S110), and determines whether to end the processing of workpiece W (step S111).

[0141] If the processing is determined to be terminated ("Yes" in step S111), the series of processes in this flowchart ends. If the processing is determined not to be terminated ("No" in step S111), the process proceeds to step S104 and repeats the subsequent processing. Furthermore, if the control unit 54 determines in step S108 that no planing has occurred ("No" in step S108), and determines that the processing was performed under processing conditions that did not converge within the control range 61 but did not result in planing, a new processing condition is set (e.g., changing the focal position Fp and / or processing speed Fr in a way that the detection value converges within the control range 61), and processing is performed under the new processing condition. That is, the processing conditions (e.g., processing speed Fr and focal position Fp) 51c are corrected (step S112) so that the detection value of the size OIS of the optical image OI and the peak value PV of the light intensity LI of the optical image OI are close to the reference values ​​included in the evaluation table 51d above.

[0142] Then, the operation of the laser processing unit 1 is controlled according to the corrected processing conditions 51c to process the workpiece W (step S113), and then the process is transferred to the above step S110. Based on the corrected processing conditions 51c being overlaid on the processing program 51b and recorded, the process is stored in the database 51a (step S110), and the subsequent processing is repeated.

[0143] Specifically, the correction of processing condition 51c is performed as follows. First, regarding the focal position Fp, for example in Figure 4 In this scenario, assuming processing is performed under laser L as reference condition 60 (cutting speed Fr is F4500, focal position Fp is -4), if the detected values ​​of the size OIS and / or peak PV, based on image information representing the actual captured optical image OI, are the detection values ​​of the optical image OI captured at a focal position Fp that represents a focal position Fp that is -2 higher than the reference value when compared to the reference value, then a correction is performed to decrease the focal position Fp from -2 towards the reference value. That is, in this case, the correction is performed by moving the focal position Fp towards -6, which is 2 lower than the focal position Fp of reference condition 60. Conversely, if the detected value is the detection value of the optical image OI captured at a focal position Fp that represents a focal position Fp that is -6 lower than the reference value, then the correction is performed by moving the focal position Fp towards -2, which is 2 higher than the focal position Fp of reference condition 60.

[0144] Additionally, regarding the processing speed (cutting speed) Fr, specifically, for example in... Figure 4In this scenario, assuming processing is performed under laser L as reference condition 60 (cutting speed Fr is F4500, focal position Fp is -4), if the detected values ​​of the size OIS and / or peak PV, based on image information representing the actual captured optical image OI, are the detected values ​​of the optical image OI captured at a processing speed Fr that indicates a slower cutting speed Fr compared to the reference value (F3000), then a correction is performed to increase the cutting speed Fr. In other words, in this case, the correction refers to making the cutting speed Fr F1500 faster than the cutting speed Fr of reference condition 60 (F4500). Conversely, the detection value is the detection value of the optical image OI captured when the actual cutting speed Fr is faster than the cutting speed Fr of reference condition 60 at F5500. This means that the cutting speed Fr is corrected to be F4500, which is F1000 slower than the cutting speed Fr of reference condition 60 at F4500.

[0145] Furthermore, in step S113 above, the workpiece W can be machined according to the corrected machining conditions 51c. Additionally, in correcting the machining conditions 51c, at least one of the focal point position Fp and the cutting speed Fr can be corrected, for example.

[0146] Furthermore, in the laser processing quality determination function described above, the control unit 54 can determine the quality of both cut-off and through-processing, in addition to the cut-off processing. The determination of the quality of through-processing is performed, for example, as follows: During through-processing, when the workpiece W is not through-processed, the camera 40 captures reflected light from the surface of the workpiece W; however, when the workpiece W is through-processed, the camera 40 receives almost no light and therefore does not capture reflected light. The presence or absence of this reflected light capture is detected according to, for example, its relationship with switching time, capture time, etc., thereby determining the quality of the through-processing.

[0147] Alternatively, the control unit 54 may be configured to, for example, refer to various information stored or recorded in the database 51a of the storage unit 51, such as reference values, processing conditions 51c, detection values ​​of various parameters, evaluation table 51d, and image information of the optical image OI, and use the optical image OI obtained from the processing area of ​​the workpiece W captured in real time by the camera 40 to perform early warning management of the occurrence of processing defects in the workpiece W in the laser processing machine 100. Early warning management is a known technology, so its description is omitted here. In this way, appropriate measures (such as stopping laser processing) can be taken automatically before processing defects occur in the workpiece W.

[0148] Figure 25 This is a block diagram that schematically illustrates the functional structure of a laser processing machine 100 according to other embodiments. Furthermore, in Figure 25In subsequent descriptions, identical or equivalent constituent elements will be marked with the same symbol and repeated descriptions will be omitted.

[0149] like Figure 25 As shown, the NC device 50' of this embodiment differs from the NC device 50 of the previous embodiment in that the learning unit 56, which performs machine learning (reinforcement learning), is connected to the control unit 54. Specifically, the learning unit 56 includes a state observation unit (not shown) that observes, for example, the size of the optical image OI and the peak value of the light intensity L1 (PV) of the optical image OI, from the above-mentioned processing quality determination results, the evaluation table 51d of the database 51a, the image information of the optical image OI captured by the camera 40, and the parameters obtained by analyzing the optical image OI (the size of the optical image OI OIS, the peak value of the light intensity L1 of the optical image OI), as state variables. Furthermore, the learning unit 56 includes a decision unit that calculates a quality score based on the values ​​representing how close the focal position Fp of the laser L and the cutting speed Fr of the laser L relative to the workpiece W are to the focal position Fp and cutting speed Fr of the reference condition 60, and the processing quality. This quality score is then learned by associating it with the state variables observed by the state observation unit to determine the processing condition 51c. The decision-making unit also has a correction unit that corrects the focal position Fp and the cutting speed Fr, which become the reference condition 60. Through machine learning in the learning unit 56, various factors such as the state variables required to determine the good or optimal processing conditions 51c, as described above, such as the good ranges 61a and 61b, the control range 61, and the first segment 71 to the fourth segment 74, can also be stored in the database 51a. Furthermore, if the learning model and learning data obtained through such machine learning are stored in the database 51a and flexibly used in the laser processing machine 100, fully automatic control of the laser processing unit 1 can also be achieved.

[0150] Furthermore, depending on the user of the laser processing machine 100, even if it is not based on convergence within a good range 61a, 61b ( Figure 16 ), control range 61 ( Figure 4 For laser processing under good or optimal processing conditions 51c, there is a need to perform high-quality laser processing (good laser processing) at high speed based on the good processing conditions at that time (hereinafter referred to as "near-optimal processing conditions"), as long as it is possible to perform laser processing of quality close to that processing condition 51c more quickly. Therefore, it is also possible to configure the process so that the near-optimal processing conditions can be easily selected or set through machine learning.

[0151] Here, as a specific example of machine learning, examples such as the following are given.

[0152] Figure 19This is a diagram used to illustrate an example of the relationship between the optical image OI of the laser processing machine 100, the focal position Fp of the laser L, and the processing speed (cutting speed) Fr. Figures 20-24 This is a diagram used to illustrate an example of the parameters of an optical image (OI).

[0153] like Figure 19 As shown, the optical image OI captured by the camera 40 can be represented by the relationship between the focal position Fp and the cutting speed Fr. For example, focusing on the points (1) to (3) below, the image processing unit 53 analyzes the image information and thereby creates state variables for machine learning.

[0154] That is, here we focus on the baseline condition 60 mentioned above ( Figure 4 The control range of the first optical image OIa is 61 ( Figure 4 The peripheral optical images OI are as follows. Furthermore, as peripheral optical images OI, for example, the fourth optical image OId, the fifth optical image OI1, the sixth optical image OI2, and the seventh optical image OI3 will be described.

[0155] [Regarding the focus (1)]

[0156] First, in the distribution of light intensity LI, the further the focal position Fp is from the reference condition 60, which is the optimal processing condition, the more the value of the peak PV of the light intensity LI of the optical image OI increases or decreases slightly. That is, when the peak PV increases, it can be considered as moving away from the reference condition 60. Furthermore, regarding the peak PV, for example, as... Figure 20 As shown, peak values ​​along the travel direction of laser L are classified as PV1, and peak values ​​perpendicular to the travel direction are classified as PV2. Even in this case, both PV1 and PV2 show the same tendency. This tendency can be determined based on... Figures 21-23 We can understand the part shown in (1) of the analytical image.

[0157] [Regarding the focus (2)]

[0158] Next, in the distribution of light intensity LI, the focal position Fp increases (with OI2 ( Figure 22 ), OIa( Figure 21 ) and OI1 ( Figure 20 (Referring to the sequence of the analytical images), the more difficult it is for the laser L to reach the lower surface before cutting, therefore in these... Figure 22 , Figure 21 and Figure 20From the parts shown in (2)-(A) of the analytical image, it can be seen that the distribution shape of the light intensity LI representing the peak PV2, i.e., the "width of the base of the mountain shape", tends to widen in the order of the sixth optical image OI2, the first optical image OIa, and the fifth optical image OI1. Furthermore, in Figure 22 , Figure 21 and Figure 20 From the parts shown in (2)-(B) of the analytical image, it can be seen that the distribution shape of the light intensity LI representing the peak PV1, namely the "mountain-shaped tilt", tends to slow down in the order of the sixth optical image OI2, the first optical image OIa and the fifth optical image OI1.

[0159] Additionally, the slower the cutting speed Fr (with OId ( Figure 24 ), OIa( Figure 21 ) and OI3 ( Figure 23 (Refer to the analytical image for the order of the images). The easier it is for laser L to reach the lower surface before cutting, therefore in these... Figure 24 , Figure 21 and Figure 23 From the parts shown in (2)-(A) of the analytical image, it can be seen that the distribution shape of the light intensity LI of the peak PV2 in the fourth optical image OId, the first optical image OIa, and the seventh optical image OI3, i.e., the "width of the base of the mountain shape", tends to narrow. In addition, in Figure 24 , Figure 21 and Figure 23 From the parts shown in (2)-(B) of the analytical image, it can be seen that the distribution shape of the light intensity LI representing the peak PV1, i.e., the "mountain-shaped inclination", tends to become steeper in the order of the fourth optical image OId, the first optical image OIa, and the seventh optical image OI3. Furthermore, from... Figure 24 The analytical image also shows that the peak PV increases sharply when planing occurs.

[0160] [Regarding the focus (3)]

[0161] Furthermore, in the distribution of size OIS, the focal position Fp decreases as OI1( Figure 20 ), OIa( Figure 21 ) and OI2 ( Figure 22 (Refer to the analytical image for the order of the images). The easier it is for laser L to reach the lower surface before cutting, therefore in these... Figure 20 , Figure 21 as well as Figure 22 The analytical images show that the size of the OIS tends to decrease in the order of the fifth optical image OI1, the first optical image OIa, and the sixth optical image OI2.

[0162] Next, in addition to the state variables generated by analyzing the image information based on these points of interest (1) to (3), the learning unit 56 calculates a quality score based on the values ​​representing how close the focal position Fp and cutting speed Fr of the laser L are to the reference condition 60, as described above, and the processing quality. Furthermore, the value representing how close it is to the reference condition 60 can vary depending on other information included in the processing condition 51c, such as the focal position Fp and cutting speed Fr of the laser L, and can be represented by any range of values. Additionally, processing quality refers to the quality determined by factors such as the presence or absence of poor cutting, the actual height of slag, or the degree of planing; this processing quality may also affect the quality score along with the aforementioned values. The learning unit 56 learns by associating the calculated quality score with the state variables and determines the processing condition 51c. Furthermore, the control unit 54 performs laser processing under the determined processing conditions 51c. The learning unit 56 displays a quality score on the display unit 52, indicating the processing quality (e.g., "best," "excellent," "good," etc.) by showing how closely the focal position Fp and cutting speed Fr of the laser L at this time approximate the optimal processing conditions. It also corrects at least the focal position Fp and cutting speed Fr of the reference condition 60 to approximate the near-optimal processing conditions. Additionally, the learning unit 56 calculates an adjustment score indicating how closely the focal position Fp and cutting speed Fr of the current laser processing conditions 51c approximate the corrected reference condition 60, or the degree of adjustment required to achieve this approximation. Thus, the learning unit 56 uses the size OIS of the optical image OI and the cutting speed Fr relative to the workpiece W as state variables. It uses the quality score calculated based on the values ​​and processing quality to indicate how closely the focal position Fp and cutting speed Fr of the laser L approximate the reference condition 60. By associating the state variables and the quality score, it learns and determines the processing conditions 51c. Various data used in machine learning, as well as the learning data obtained, are stored in storage unit 51 and accumulated in database 51a.

[0163] Furthermore, as a result of this machine learning, the control unit 54 can, for example, display the processing quality of the current laser processing as a quality score on the display unit 52, or display values ​​indicating the degree to which the focal position Fp and the cutting speed Fr should be adjusted to approach the reference condition 60 during the current laser processing, based on image information captured in real time by the camera 40 and obtained from the image processing unit 53, and learning data from the learning unit 56. Through machine learning, the processing conditions 51c can be automatically determined and adjusted, and automatic control can be performed.

[0164] As described above, according to this embodiment, the size OIS of the optical image OI and the peak value PV of the light intensity L1 of the optical image OI can be obtained based on the image information of the optical image OI of the processing area of ​​the workpiece W. The focal position Fp and cutting speed Fr of the laser L are then controlled to perform laser processing, so that the detected values ​​are, for example, close to a reference value. Therefore, irradiating the processing area with the laser L results in accurately determining and responding to the state of the light LW generated in the processing area, and controlling the laser processing.

[0165] Symbol Explanation

[0166] 1 Laser processing unit

[0167] 2. Image Interface

[0168] 3 Input Interface

[0169] 4 Output Interfaces

[0170] 8. Image Analysis

[0171] 9. Optical Image Area

[0172] 10 Laser Oscillators

[0173] 11. Process Fiber

[0174] 20 Laser processing heads

[0175] 20a Housing

[0176] 21 Collimating Lens

[0177] 22. Curved mirror

[0178] 23 Condensing Lenses for Processing

[0179] 24. Condensing lens for shooting.

[0180] 40 cameras

[0181] 50 NC device

[0182] 51 Storage Department

[0183] 51a Database

[0184] 52 Display Section

[0185] 53 Image Processing Department

[0186] 54 Control Department

[0187] 55 Input Section

[0188] 100 Laser processing machine.

Claims

1. A laser processing machine, characterized in that, have: A laser processing unit that uses a laser to cut workpieces; An imaging device that captures an image of a workpiece irradiated with the laser; and A control device that controls the laser processing unit according to the processing conditions for processing the workpiece. The control device controls the operation of the laser processing unit to make the size and peak light intensity of the optical image observed from the image information approach a preset reference value, wherein the image information is obtained by the imaging device capturing images of the workpiece. The specified processing conditions for the operation of the laser processing unit controlled by the control device include the focal position of the laser and the processing speed of the laser relative to the workpiece. The control device performs the following control: When the peak light intensity is smaller than the reference value, the operation of the laser processing unit is controlled to increase the processing speed and / or decrease the focal position; and If the peak value of the light intensity is greater than the reference value, the operation of the laser processing unit is controlled to slow down the processing speed and / or raise the focal position.

2. A laser processing machine, characterized in that, have: A laser processing unit that uses a laser to cut workpieces; An imaging device that captures an image of a workpiece irradiated with the laser; and A control device that controls the laser processing unit according to the processing conditions for processing the workpiece. The control device controls the operation of the laser processing unit to make the size and peak light intensity of the optical image observed from the image information approach a preset reference value, wherein the image information is obtained by the imaging device capturing images of the workpiece. The specified processing conditions for the operation of the laser processing unit controlled by the control device include the focal position of the laser and the processing speed of the laser relative to the workpiece. The control device performs the following control: When the size of the optical image is smaller than the reference value, the operation of the laser processing unit is controlled to increase the processing speed and / or raise the focal position; and When the size of the optical image is larger than the reference value, the operation of the laser processing unit is controlled to slow down the processing speed and / or lower the focal position.

3. The laser processing machine according to claim 1 or 2, characterized in that, The control device has: Storage unit, which stores the reference value; An image processing unit analyzes the image information to calculate the size of the optical image and the peak value of the light intensity; as well as The control unit activates the laser processing unit to bring the size and peak value of the optical image close to the reference value stored in the storage unit.

4. The laser processing machine according to claim 1 or 2, characterized in that, The control device controls at least one of the focal position and the processing speed to cause the size and / or the peak value observed from the image information to converge within a predetermined control range, wherein the predetermined control range includes the size and / or the peak value representing the reference value.

5. The laser processing machine according to claim 1 or 2, characterized in that, The control device controls the operation of the laser processing unit based on the size of the optical image and the peak value of the light intensity, so that the focal position of the laser and the cutting speed of the laser relative to the workpiece are close to the preset reference conditions.

6. The laser processing machine according to claim 5, characterized in that, The laser processing machine also has a learning unit. The learning department has: A state observation unit observes the size of the optical image and the peak value of the light intensity as state variables; and The decision-making unit calculates a quality score based on the values ​​representing the focal position of the laser, how close the laser's processing speed relative to the workpiece is to the reference conditions, and the processing quality. It then learns by associating the quality score with the state variables observed by the state observation unit to determine the processing conditions.

7. The laser processing machine according to claim 6, characterized in that, The laser processing machine also features: A display unit that displays the calculated quality score; and The correction unit corrects the focal position of the laser and the processing speed of the laser relative to the workpiece, which are the reference conditions.

8. A processing method using a laser processing machine, the laser processing machine comprising: a laser processing unit that uses a laser to perform laser cutting processing on a workpiece; an imaging device that captures an image of the workpiece irradiated by the laser; and a control device that controls the laser processing unit according to processing conditions for processing the workpiece, characterized in that... The control device controls the operation of the laser processing unit to perform processing, so that the size and peak light intensity of the optical image observed from the image information meet preset reference values. The image information is obtained by the imaging device capturing images of the workpiece. The processing conditions to be corrected include the focal position of the laser and the processing speed of the laser relative to the workpiece. If the peak light intensity is smaller than the reference value, the processing conditions are adjusted to increase the processing speed and / or decrease the focal position. If the peak value of the light intensity is greater than the reference value, the processing conditions are corrected to slow down the processing speed and / or raise the focal position.

9. A processing method using a laser processing machine, the laser processing machine comprising: a laser processing unit that uses a laser to perform laser cutting processing on a workpiece; an imaging device that captures an image of the workpiece irradiated by the laser; and a control device that controls the laser processing unit according to processing conditions for processing the workpiece, characterized in that... The control device controls the operation of the laser processing unit to perform processing, so that the size and peak light intensity of the optical image observed from the image information meet preset reference values. The image information is obtained by the imaging device capturing images of the workpiece. The processing conditions to be corrected include the focal position of the laser and the processing speed of the laser relative to the workpiece. When the size of the optical image is smaller than the reference value, the processing conditions are adjusted to increase the processing speed and / or raise the focal position. If the size of the optical image is larger than the reference value, the processing conditions are corrected to slow down the processing speed and / or lower the focal position.

10. The processing method according to claim 8 or 9, characterized in that, The processing conditions are corrected so that the size of the optical image and the peak value of the light intensity are close to the reference value, and the operation of the laser processing unit is controlled according to the corrected processing conditions.

11. The processing method according to claim 8 or 9, characterized in that, The processing conditions are corrected by changing at least one of the focus position and the processing speed, so that the size and / or the peak value observed from the image information converges within a predetermined control range, wherein the predetermined control range includes the size and / or the peak value representing the reference value.

12. The processing method according to claim 8 or 9, characterized in that, The control device controls the operation of the laser processing unit to perform processing based on the size of the optical image and the peak value of the light intensity, so that the focal position of the laser and the cutting speed of the laser relative to the workpiece are close to the preset reference conditions.

13. The processing method according to claim 12, characterized in that, The size of the optical image and the peak value of the light intensity are observed as state variables. A quality score is calculated based on the values ​​representing the focal position of the laser, how close the laser's processing speed relative to the workpiece is to the reference conditions, and the processing quality. This quality score is then correlated with observed state variables to learn and determine the processing conditions.

Images