JP2024011364A - Nozzle state determination device, laser beam machine, and nozzle state determination method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nozzle state determination device, a laser beam machine, and a nozzle state determination method which can properly determine the state of a nozzle of a laser head.

SOLUTION: A nozzle state determination device 11 for determining the state of a nozzle 12 of a laser head 4 in a laser beam machine 1 for processing a workpiece W with a laser beam L1 emitted from the laser head 4 comprises: an imaging unit 27 which images the workpiece W by detecting light emitted from the workpiece W in the time of processing the workpiece W via a portion of a laser beam passage space in the laser head 4; and a determination unit 42 which determines the state of the nozzle 12. The imaging unit 27 images the nozzle 12 when processing with the laser beam L1 is not performed by the laser beam machine 1. The determination unit 42 determines the state of the nozzle 12 on the basis of the shape of a nozzle hole 121 included in an image of the nozzle 12 imaged by the imaging unit 27.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a nozzle state determination device, a laser processing machine, and a nozzle state determination method.

2. Description of the Related Art A laser processing machine that processes a workpiece using a laser beam emitted from a laser head is known (see Patent Document 1). The laser processing machine described in Patent Document 1 uses an imaging unit provided outside the laser head to image a nozzle hole from outside the laser head, and based on the captured image, detects nozzle conditions such as nozzle abnormalities. is being determined.

Patent No. 6431937

In the laser processing machine described in Patent Document 1, the state of the nozzle is determined based on an image of the nozzle hole taken from outside the laser head. Therefore, if the condition of the nozzle is due to the internal structure of the laser head, it may be difficult to appropriately determine the condition.

An object of the present invention is to provide a nozzle state determining device, a laser processing machine, and a nozzle state determining method that can appropriately determine the state of a nozzle of a laser head.

A nozzle state determining device according to an aspect of the present invention is a nozzle state determining device for determining the state of a nozzle of a laser head in a laser processing machine that processes a workpiece using a laser beam emitted from a laser head, and the nozzle state determining device determines the state of a nozzle of a laser head when processing a workpiece. The imaging section includes an imaging section that images the workpiece by detecting the light emitted from the laser beam through a part of the laser light passage space in the laser head, and a determination section that determines the state of the nozzle. The nozzle is imaged when the processing machine is not processing the nozzle with laser light, and the determination unit determines the state of the nozzle based on the shape of the nozzle included in the image of the nozzle captured by the imaging unit.

A nozzle state determination method according to an aspect of the present invention is a nozzle state determination method for determining the state of a nozzle of a laser head in a laser processing machine that processes a workpiece with laser light emitted from a laser head, the laser processing machine comprising: It is equipped with an imaging unit that captures an image of the workpiece by detecting the light emitted from the workpiece during processing of the workpiece through a part of the laser light passage space in the laser head, and when processing is not being performed with the laser light, The method includes the steps of: capturing an image of the nozzle with an image capturing section; and determining the state of the nozzle based on the shape of the nozzle included in the image of the nozzle captured by the image capturing section.

According to the nozzle state determination device or laser processing machine according to the above aspect, the nozzle state is determined using an image captured from inside the laser head, which is captured by the imaging unit for monitoring the processing state during laser processing. Therefore, even if an abnormality occurs in the nozzle due to the internal structure of the laser head, the abnormality can be detected and the state of the nozzle can be appropriately determined.

Further, in the nozzle state determination device or laser processing machine according to the above aspect, the imaging unit captures a first image of the nozzle and a second image of the nozzle having a brightness different from the first image, and the determination unit captures a first image of the nozzle. A difference image between the first image and the second image may be generated, and the state of the nozzle may be determined based on the difference image. With these configurations, the external image is taken from inside the processing head, so the nozzle wall can be canceled out on the image, so the nozzle shape can be detected by taking the difference between multiple images with different brightness. Nozzle abnormalities can be determined with high accuracy.

Further, in the nozzle state determination device or laser processing machine according to the above aspect, the nozzle state determination device includes an illumination unit that generates illumination light, and the first image is generated by the illumination light reflected by the first test plate being captured by the imaging unit. The second image is an image generated when the imaging unit detects the illumination light reflected by the second test plate, which has a different reflectance from the first test plate. There may be. With these configurations, the first image and the second image having different brightness can be easily captured.

Further, in the nozzle state determination device or laser processing machine according to the above aspect, the determination unit is configured such that the shape of the nozzle based on the image captured by the imaging unit is set in advance with respect to the initial shape of the nozzle used for processing the workpiece. If the value exceeds a predetermined range, it may be determined that there is an abnormality in the nozzle. With these configurations, when the nozzle is deformed due to laser processing or when the nozzle is incorrectly installed, it is possible to determine that the nozzle is abnormal.

Further, in the nozzle state determination device or laser processing machine according to the above aspect, the laser processing machine includes a nozzle changer that automatically replaces the nozzle, and the determination unit acquires information regarding the nozzle replacement performed by the nozzle changer, The state of the nozzle may be determined before or after replacing the nozzle. These configurations can prevent laser processing on nozzles with different hole diameters or nozzles that have been deformed due to damage or the like.

Furthermore, in the nozzle state determination device or laser processing machine according to the above aspect, the determination unit may determine the state of the nozzle when processing a workpiece using the laser processing machine. With these configurations, the state of the nozzle can be determined before laser processing a workpiece, during the laser processing process (excluding during laser irradiation), and after laser processing.

Further, in the nozzle state determination device or laser processing machine according to the above aspect, the determination unit performs an ellipse fitting process on the nozzle image captured by the imaging unit or a perfect circle fitting process on the nozzle image captured by the imaging unit. At least one of the hole diameter, circularity, and oblateness of the nozzle may be determined based on the results of the processing. With these configurations, the shape of the nozzle can be determined with high accuracy.

Further, the laser processing machine according to the above aspect includes a nozzle changer that automatically replaces the nozzle, a replacement control unit that controls the nozzle replacement by the nozzle changer, and a nozzle condition determination device when it is determined that there is an abnormality in the nozzle. , and a processing control section that instructs the exchange control section to cause the nozzle changer to exchange the nozzle. With these configurations, if there is an abnormality in a nozzle, the nozzle can be automatically replaced by the nozzle changer.

Further, the laser processing machine according to the above aspect includes a nozzle changer that automatically replaces the nozzle, a notification unit that notifies the user of information regarding the nozzle replacement, and a nozzle state determination device when the nozzle is determined to have an abnormality. , and a processing control unit that instructs the notification unit to notify that the nozzle should be replaced. With these configurations, if there is an abnormality in a nozzle, the user can be prompted to replace the nozzle.

Further, the laser processing machine according to the above aspect may include a processing control unit that stops processing the workpiece when the nozzle state determining device determines that the nozzle is abnormal. With these configurations, if there is an abnormality in the nozzle, processing can be stopped.

Further, in the nozzle state determination device or laser processing machine according to the above aspect, the laser head performs marking processing on the surface of the workpiece with laser light, and the marking processing is an image photographed by an imaging unit provided in the nozzle state determination device. a detection unit that detects the misalignment of the center position of the laser beam with respect to the center position of the nozzle hole based on the image of the marking mark formed on the workpiece by the may be provided. With these configurations, only the surface of the workpiece is altered (burned) by marking, thereby suppressing the generation of dross, and making it possible to accurately detect the center position using image processing.

FIG. 1 is a diagram showing an example of a laser processing machine and a nozzle state determination device according to a first embodiment. FIG. 1 is a diagram showing an example of the configuration of a laser head according to a first embodiment. FIG. 3 is a diagram illustrating an example of a functional unit of the image processing device according to the first embodiment. It is a figure showing an example of kerf width measurement by an image concerning a 1st embodiment. It is a figure showing an example of a combustion state by an image concerning a 1st embodiment. It is a figure showing an example of arrangement of a test plate concerning a 1st embodiment. It is a figure showing an example of arrangement of a test plate concerning a 1st embodiment. It is a figure showing an example of the 1st image and the 2nd image concerning a 1st embodiment. FIG. 3 is a diagram showing an example of a difference image according to the first embodiment. It is a figure explaining the calculation method of the hole diameter of the nozzle concerning a 1st embodiment. It is a figure showing the calculation method of the flatness rate concerning a 1st embodiment. FIG. 3 is a flow diagram of nozzle determination processing according to the first embodiment. It is a modification of the laser processing machine according to the first embodiment. It is a figure showing the laser processing machine concerning a 2nd embodiment. FIG. 7 is a diagram illustrating an example of a functional unit of an image processing device according to a second embodiment. It is a figure which shows an example of arrangement|positioning of the test plate based on 2nd Embodiment. It is a figure which shows an example of arrangement|positioning of the test plate based on 2nd Embodiment. It is a figure explaining marking processing concerning a 2nd embodiment. It is a figure which shows an example of the marking position based on 2nd Embodiment. FIG. 7 is a diagram illustrating a method for detecting misalignment according to a second embodiment. FIG. 7 is a flow diagram of a misalignment detection method according to a second embodiment. It is a figure showing an example of the user interface concerning a 2nd embodiment. It is a figure showing the laser processing machine concerning a 3rd embodiment. FIG. 7 is a diagram illustrating an example of a functional unit of an image processing device according to a third embodiment. It is a figure which shows an example of arrangement|positioning of the test plate based on 3rd Embodiment. It is a figure which shows an example of arrangement|positioning of the test plate based on 3rd Embodiment. It is a flowchart of the operation of the laser processing machine concerning a 3rd embodiment.

Hereinafter, the present invention will be explained through embodiments, but the following embodiments do not limit the invention according to the claims. Furthermore, not all combinations of features described in the embodiments are essential to the solution of the invention. In addition, in the drawings, the same or similar parts may be denoted by the same reference numerals and redundant explanations may be omitted. In addition, the shapes and sizes of elements in the drawings may be exaggerated for clearer explanation.

Directions in the figures may be explained using an XYZ coordinate system. In the XYZ coordinate system, a plane parallel to the horizontal plane is defined as an XY plane. Further, the direction perpendicular to the XY plane is referred to as the Z direction. The X direction, Y direction, and Z direction will be explained assuming that the direction of the arrow in the figure is the + direction, and the direction opposite to the direction of the arrow is the - direction.

[First embodiment]
FIG. 1 is a diagram showing an example of a laser processing machine 1 and a nozzle state determination device 11 according to the first embodiment. The laser processing machine 1 according to the first embodiment emits a laser beam L to perform laser processing such as cutting and marking on a workpiece W to be processed. The laser processing machine 1 includes a laser oscillator 2, a laser head 4, an assist gas supply section 5, a head drive section 6, a processing control section 7, a nozzle changer 8, an exchange control section 9, and a notification section 10. , and a nozzle state determination device 11. The nozzle state determination device 11 includes an illumination section 3, an observation optical system 14, an imaging section 27, and an image processing device 31.

The laser oscillator 2 generates a processing laser beam L1. For example, the processing laser beam L1 is an infrared laser beam. Laser oscillator 2 is connected to laser head 4 via optical fiber F. The optical fiber F introduces the processing laser beam L1 output from the laser oscillator 2 into the laser head 4.

The illumination unit 3 is connected to the laser head 4. The illumination unit 3 includes a laser light source 3A and a collimator 3B. The laser light source 3A emits illumination laser light L2 (illumination light) having a different wavelength from the processing laser light L1. The collimator 3B is provided at a position where the illumination laser light L2 enters from the laser light source 3A, and converts the illumination laser light L2 that enters from the laser light source 3A into parallel light.

The laser head 4 irradiates the work W with laser light L (processing laser light L1 and illumination laser light L2) from the nozzle 12. The laser head 4 is provided so as to be movable relative to the workpiece W in the X direction, the Y direction, and the Z direction. The laser head 4 performs laser processing by irradiating the processing laser beam L1 onto the workpiece W while moving relative to the workpiece W.

FIG. 2 is a diagram showing an example of the configuration of the laser head 4. As shown in FIG. As shown in FIG. 2, the laser head 4 includes a nozzle 12 and an irradiation optical system 13. The nozzle 12 is attached below the laser head 4. Nozzle 12 is directed downward. The nozzle 12 has a nozzle hole 121 that is an emission hole.

The processing laser light L1 and the illumination laser light L2 are irradiated downward from the nozzle hole 121. The nozzle 12 is connected to the assist gas supply section 5 via a gas supply pipe or the like. The nozzle 12 supplies assist gas from the assist gas supply section 5 to the workpiece W toward a region to which the processing laser beam L1 is irradiated.

The irradiation optical system 13 is provided inside the laser head 4. The irradiation optical system 13 irradiates the work W through the nozzle hole 121 of the nozzle 12 by guiding the processing laser light L1 generated by the laser oscillator 2 toward the work W. For example, the irradiation optical system 13 includes a collimator 21, a beam splitter 22, and a condenser lens 23.

The collimator 21 is provided so that the focal point on the incident side of the processing laser beam L1 coincides with the position of the end of the optical fiber F, and converts the processing laser beam L1 output from the laser oscillator 2 into parallel light. The beam splitter 22 is provided at a position where the processing laser light L1 that has passed through the collimator 21 is incident, transmits the processing laser light L1, and reflects the illumination laser light L2. The condensing lens 23 is housed in the laser head 4. The condensing lens 23 is provided at a position where the processing laser beam L1 from the beam splitter 22 is incident, and condenses the incident processing laser beam L1. The condensing lens 23 is movable along the optical axis by an optical system drive unit (not shown). The focus on the workpiece W side is adjusted by this optical system drive section.

The observation optical system 14 is provided inside the laser head 4. The observation optical system 14 includes a half mirror 24, a wavelength selection filter 25, and an imaging lens 26. The half mirror 24 is provided at a position where the illumination laser light L2 that has passed through the collimator 3B is incident, and reflects part of the illumination laser light L2 and allows part of it to pass through. The illumination laser beam L2 reflected by the half mirror 24 is reflected by the beam splitter 22. The condensing lens 23 condenses the illumination laser beam L2 reflected from the beam splitter 22. The area of the workpiece W that is irradiated with the illumination laser beam L2 is set to include the area of the workpiece W that is irradiated with the processing laser beam L1.

The return light from the workpiece W passes through the condenser lens 23 and enters the beam splitter 22 . The returned light includes light that is the illumination laser beam L2 reflected and confused by the work W, and light that is the processing laser beam L1 that is reflected by the work W. Light originating from the illumination laser beam L2 is reflected by the beam splitter 22 and enters the half mirror 24. Similarly, the light originating from the processing laser beam L1 is reflected by the beam splitter 22 and enters the half mirror 24.

The wavelength selection filter 25 is, for example, a dichroic mirror, a notch filter, or the like. The returned light that has entered the half mirror 24 passes through the half mirror 24 and enters the wavelength selection filter 25 . Light originating from the illumination laser beam L2 is reflected by the wavelength selection filter 25 and enters the imaging lens 26. On the other hand, the light originating from the processing laser beam L1 passes through the wavelength selection filter 25. The imaging lens 26 focuses the light reflected by the wavelength selection filter 25 onto the imaging section 27 .

As shown in FIG. 1, the assist gas supply section 5 is connected to the laser head 4. The assist gas supply unit 5 supplies assist gas into the nozzle 12 . Assist gas is used in laser processing to remove molten material. As the assist gas supply source, for example, a gas cylinder, a factory supply line, etc. are used. As the assist gas, for example, nitrogen gas, air, or a mixture of nitrogen and oxygen is used.

The head driving section 6 is controlled by the processing control section 7 and moves the laser head 4 in each of the X direction, the Y direction, and the Z direction. The head drive unit 6 includes, for example, a gantry that is movable in the X direction, a slider that is movable in the Y direction with respect to the gantry, and an elevating unit that is movable in the Z direction with respect to the slider. Note that the head drive unit 6 is not limited to the above configuration, and may be realized by other configurations such as a robot arm.

The processing control section 7 controls the movement of the laser head 4 by controlling the head drive section 6 . For example, the processing control unit 7 acquires position information of the laser head 4 at a predetermined period, and controls movement of the laser head 4 by controlling the head drive unit 6 based on the acquired position information. Further, the processing control unit 7 controls the assist gas supply unit 5 to start injection of assist gas, and causes the laser oscillator 2 to output the processing laser beam L1, so that the irradiation optical system 13 applies the processing laser beam to the workpiece W. The laser beam L1 is irradiated.

The nozzle changer 8 exchanges the nozzle 12 based on control from the exchange control section 9. The nozzle changer 8 arranges a plurality of nozzles 12 in a nozzle accommodating portion (not shown), and attaches one of the nozzles 12 to the tip of the laser head 4 . The replacement control unit 9 controls the replacement of the nozzle 12 by the nozzle changer 8 .

The notification unit 10 is connected to a nozzle state determination device 11. The notification unit 10 notifies the user of information obtained from the nozzle state determination device 11. For example, the notification unit 10 notifies the user of information regarding replacement of the nozzle 12. The information regarding the replacement of the nozzle 12 is, for example, either or both of information indicating that the nozzle 12 is to be replaced and information indicating that the replacement of the nozzle 12 has been completed. The notification unit 10 includes, for example, a display unit or a speaker. However, the notification unit 10 is not limited thereto as long as it can notify the user of information regarding the replacement of the nozzle 12. For example, the notification unit 10 may notify the information regarding the replacement of the nozzle 12 to an information terminal used by the user. The method by which the notification unit 10 notifies the user is not particularly limited, and may be, for example, a notification by email, a pop-up notification, or a notification using SNS. The information terminal used by the user is, for example, a computer, a mobile terminal, or a wearable terminal.

The imaging section 27 is provided in the laser head 4. The imaging unit 27 images the area irradiated with the processing laser light L1. The imaging unit 27 includes an imaging element 271. The image sensor 271 is an image sensor that detects return light generated by the illumination of the illumination laser beam L2 reflected and confused by the workpiece W, and generates an image G. That is, the imaging unit 27 images the workpiece W by detecting the light emitted from the workpiece W through a part of the laser light passage space in the laser head 4 during processing of the workpiece W. The imaging unit 27 transmits the image G generated by the imaging device 271 to the nozzle state determination device 11.

The image processing device 31 is, for example, an information processing device such as a computer. The image processing device 31 is connected to the processing control section 7, and can exchange information with each other. The image processing device 31 is connected to the imaging section 27. FIG. 3 is a diagram illustrating an example of a functional unit of the image processing device 31 according to the first embodiment. The image processing device 31 includes, for example, a storage section 40, a processing state measurement section 41, and a determination section 42.

The machining state measuring section 41 and the determining section 42 are realized, for example, by a hardware processor such as a CPU (Central Processing Unit) executing a program (software). In addition, some or all of these components may be implemented using hardware such as LSI (Large Scale Integrated circuit), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), or GPU (Graphics Processing Unit). It may be realized by a circuit unit (including circuitry), or it may be realized by cooperation of software and hardware.

The storage unit 40 is configured of, for example, an HDD, a flash memory, an EEPROM (Electrically Erasable Programmable Read Only Memory), a ROM (Read Only Memory), or a RAM (Random Access Memory). The above program may be stored in the storage unit 40.

The processing state measuring section 41 receives the image G generated by the imaging section 27 during laser processing. The machining state measurement unit 41 executes image processing on the received image G and obtains feature amounts related to the machining state. As illustrated in FIG. 4, the machining state measuring unit 41 calculates, for example, a kerf width K as a feature amount related to the machining state. For example, the machining state measuring unit 41 detects edges at both ends of the kerf formed by laser processing, and calculates the kerf width K by converting the distance between the edges on the image G into a distance on an actual scale. The machining state measuring unit 41 may quantify, for example, the combustion state (for example, brightness, etc.) of the area E of the workpiece W being processed by laser processing, as illustrated in FIG. 5, as the feature amount related to the machining state. .

The determination unit 42 receives the image G of the nozzle 12 generated by the imaging unit 27 when the laser processing machine 1 is not performing processing using the laser beam L. The determination unit 42 performs image processing on the received image G of the nozzle 12, and determines the state of the nozzle 12 based on the shape of the nozzle hole 121 included in the image G (hereinafter referred to as "nozzle determination process"). ). The state of the nozzle 12 is, for example, whether or not there is an abnormality in the nozzle 12.

The determination unit 42 executes a nozzle determination process, for example, when the nozzle 12 is replaced by the nozzle changer 8. However, the present invention is not limited to this, and the nozzle determination process may be performed before or after replacing the nozzle 12. In other words, the nozzle determination process may be performed at least either before or after the nozzle 12 is replaced. Further, the nozzle determination process may be executed when the workpiece W is processed. The processing of the workpiece W includes at least one of before laser processing, during the laser processing process (excluding during laser irradiation), and at the end of laser processing. The phrase "during the laser processing process" includes at least one of a case where a certain period of time has passed since the laser processing was started, and a case where the laser processing is temporarily stopped due to some reason such as when an abnormality occurs.

Here, the image G captured when processing by the processing laser beam L1 is not performed includes, for example, a first image G1 and a second image G2. The first image G1 and the second image G2 are images of the nozzle 12 captured by the imaging unit 27 when laser processing is not performed, and have different brightness. For example, the first image G1 is an image generated by the imaging unit 27 detecting the illumination laser beam L2 reflected by the first test plate Wt1, which is the test work W. For example, the second image G2 is a test workpiece W, and the illumination laser beam L2 reflected by the second test plate Wt2 having a different reflectance from the first test plate Wt1 is detected by the imaging unit 27. This is an image generated by . The first test plate Wt1 and the second test plate Wt2 are, for example, metal plates. For example, the first test plate Wt1 is a stainless steel plate. For example, the second test plate Wt2 is a black-plated metal plate. Note that the first test plate Wt1 and the second test plate Wt2 may be integrated or separate.

6 and 7 are diagrams showing an example of the arrangement of the first test plate Wt1 and the second test plate Wt2. FIG. 6 shows the arrangement of the first test plate Wt1 and the second test plate Wt2 when viewed from above. FIG. 7 shows the arrangement of the first test plate Wt1 and the second test plate Wt2 in a side view. Note that FIGS. 6 and 7 show a state in which a workpiece W for processing is carried into the processing area.

As shown in FIGS. 6 and 7, the laser processing machine 1 includes a movable pallet 50 and a mounting table 51. The work W to be laser processed is carried into the processing area while being placed on the pallet 50. The laser processing machine 1 laser-processes the work W on the pallet 50 that has been carried into the processing area. The workpiece W placed on the pallet 50 is a workpiece for processing (hereinafter referred to as "workpiece for processing") Wr. The first test plate Wt1 and the second test plate Wt2 are placed on a mounting table 51. The mounting table 51 is placed in the processing area. The first test plate Wt1 and the second test plate Wt2 are arranged in at least one of the moving range Hx in the X direction and the moving range Hy in the Y direction of the laser head 4 when the pallet 50 is carried into the processing area. There is. Further, the first test plate Wt1 and the second test plate Wt2 are adjacent to each other and arranged side by side in the X direction.

When acquiring the first image G1, the laser processing machine 1 moves the nozzle 12 above the first test plate Wt1. Then, the laser processing machine 1 acquires the first image G1 by using the imaging unit 27 to detect the illumination laser beam L2 reflected by the first test plate Wt1. When acquiring the second image G2, the laser processing machine 1 moves the nozzle 12 above the second test plate Wt2. Then, the laser processing machine 1 acquires the second image G2 by detecting the illumination laser beam L2 reflected by the second test plate Wt2 with the imaging unit 27. Note that the operation of the pallet 50 may be controlled by the processing control section 7 or may be controlled by another device.

FIG. 8(A) is a diagram showing an example of the first image G1 according to the present embodiment. FIG. 8(B) is a diagram showing an example of the second image G2 according to the present embodiment. The determination unit 42 acquires a first image G1 illustrated in FIG. 8(A) and a second image G2 illustrated in FIG. 8(B). The determination unit 42 generates a difference image G3 between the acquired first image G1 and second image G2. FIG. 9 is a diagram showing an example of the difference image G3 according to this embodiment.

The determination unit 42 determines the shape of the nozzle hole 121 based on the difference image G3 between the first image G1 and the second image G2. Here, the image used to determine the shape of the nozzle hole 121 may be an image of the nozzle 12 captured by the imaging unit 27 or an image generated from the image, and is not limited to the difference image G3. However, in the image of the nozzle 12 captured by the imaging unit 27, the contrast (brightness difference) between the nozzle 12 and the nozzle hole 121 is small, and the outline of the nozzle hole 121 may become unclear. Therefore, as an example, the determination unit 42 generates a difference image G3 between the first image G1 and the second image G2, which have different brightness, in order to make the outline of the nozzle hole 121 clearer on the image. Then, the determination unit 42 determines the shape of the nozzle hole 121 based on the difference image G3. Therefore, the determination unit 42 can determine the shape of the nozzle hole 121 with higher accuracy.

The determination unit 42 applies known image processing such as binarization, contour detection, and fitting processing (for example, ellipse fitting or perfect circle fitting) to the difference image G3, thereby identifying the nozzle holes included in the difference image G3. 121 shapes are generated. The feature amount related to the shape of the nozzle hole 121 is, for example, at least one of the hole diameter R of the nozzle 12, the circularity D, the oblateness f, and the center position of the nozzle hole 121.

The determination unit 42 determines the hole diameter R of the nozzle 12, for example, by applying ellipse fitting to the difference image G3. For example, the determination unit 42 performs ellipse fitting in which an ellipse is fitted to the outline of the hole diameter R of the nozzle 12 included in the difference image G3, as illustrated in FIG. 10(a). The determining unit 42 determines the major axis R1 and minor axis R2 of the fitted ellipse in the ellipse fitting. Then, the determination unit 42 determines the hole diameter R of the nozzle 12 based on the following equation (1).

Hole diameter R = ((major axis R1 + minor axis R2)/2) x optical magnification...(1)

The determination unit 42 may obtain the hole diameter R of the nozzle 12 by applying perfect circle fitting to the difference image G3. For example, as illustrated in FIG. 10(b), the determination unit 42 performs perfect circle fitting in which a perfect circle (minimum circumscribed circle) is fitted to the outline of the hole diameter R of the nozzle 12 included in the difference image G3. You can. In this case, the determination unit 42 determines the diameter R3 of the perfect circle fitted in the perfect circle fitting. Then, the determination unit 42 determines the hole diameter R of the nozzle 12 by multiplying the diameter R3 of the perfect circle by the optical magnification. Note that the determination unit 42 may apply each of the ellipse fitting process and the perfect circle fitting process, and calculate the hole diameter R based on the results of the two processes. Note that the determination unit 42 may obtain the center position of the nozzle hole 121 on the image by applying ellipse fitting or perfect circle fitting to the first image G1, the second image G2, or the difference image G3.

The determination unit 42 determines, for example, the circularity D of the region of the nozzle hole 121 (the portion indicated by the symbol NH illustrated in FIG. 9, that is, the portion with high brightness) included in the difference image G3 as the shape of the nozzle hole 121, for example. When the area of the hole of the nozzle 12 is S and the circumferential length is L, the circularity D is determined by the following equation (2), for example.

Circularity D=4・π・S/(L ² )…(2)

The determining unit 42 determines, for example, the oblateness f of the region of the nozzle 12 included in the difference image G3 (the portion indicated by the symbol NH illustrated in FIG. 9, that is, the portion with high brightness) as the shape of the nozzle hole 121, for example. For example, the determination unit 42 performs ellipse fitting on the outline of the nozzle hole 121 included in the difference image G3. The determination unit 42 determines the major radius r1 and minor radius r2 of the fitted ellipse in the ellipse fitting. Then, the determination unit 42 determines the flatness f of the nozzle hole 121 based on the following equation (3). FIG. 11 is a diagram showing an example of the oblateness f determined by ellipse fitting.

Oblateness f=(r1-r2)/r1...(3)

The determination unit 42 detects an abnormality in the nozzle 12 when the shape of the nozzle hole 121 based on the difference image G3 exceeds a predetermined range set in advance for the initial shape of the nozzle 12 used for processing the workpiece W. It is determined that there is. The initial shape of the nozzle 12 is the shape of the nozzle hole 121 when there is no abnormality in the nozzle 12, and is, for example, the shape of the nozzle hole 121 set as a processing condition for laser processing.

For example, as the initial shape, at least one of a specified value Rth of the hole diameter R of the nozzle 12, a specified value Dth of the degree of circularity D, and a specified value fth of the flatness f is registered in the storage unit 40 in advance. The determining unit 42 determines whether or not there is an abnormality in the nozzle 12 by comparing at least one of the hole diameter R, circularity D, and oblateness f of the nozzle obtained from the difference image G3 with a specified value. You can. For example, the determination unit 42 determines that there is an abnormality in the nozzle 12 when the variation range ΔR (=|R−Rth|), which is the difference between the hole diameter R and the specified value Rth, exceeds the first threshold. You can. If the variation width ΔD (=|D−Dth|), which is the difference between the circularity D and the specified value Dth, exceeds the second threshold, the determination unit 42 determines that there is an abnormality in the nozzle 12. good. The determining unit 42 may determine that there is an abnormality in the nozzle 12 when the variation range Δf (=|f−fth|), which is the difference between the flatness f and the specified value fth, exceeds a third threshold.

The flow of the nozzle determination process according to the first embodiment will be explained below using FIG. 12. FIG. 12 is a flow diagram of nozzle determination processing according to the first embodiment. For example, when the determination unit 42 receives information regarding replacement of the nozzle 12 from the replacement control unit 9, it performs a nozzle determination process. For example, when the determination unit 42 receives information from the processing control unit 7 indicating that laser processing is started or that laser processing has been completed, the determination unit 42 performs the nozzle determination process. The determination unit 42 may perform the nozzle determination process when a certain trigger signal is input.

When performing nozzle determination processing, the image processing device 31 transmits first information indicating that to the processing control unit 32. When the processing control unit 32 receives the first information from the image processing device 31, it controls the head drive unit 6 to move the laser head 4 above the first test plate Wt1 (step S101). When the laser head 4 moves above the first test plate Wt1, the imaging unit 27 converts the illumination laser beam L2 (return light) reflected by the first test plate Wt1 into a part of the laser beam passage space within the laser head 4. A first image G1 of the nozzle 12 is generated by detecting the nozzle 12 (step S102). The imaging unit 27 transmits the generated first image G1 to the image processing device 31.

When the generation of the first image G1 is completed, the processing control unit 32 controls the head drive unit 6 to move the laser head 4 above the second test plate Wt2 (step S103). When the laser head 4 moves above the second test plate Wt2, the imaging unit 27 converts the illumination laser beam L2 (return light) reflected by the second test plate Wt2 into a part of the laser beam passage space within the laser head 4. A second image G2 of the nozzle 12 is generated by detecting the nozzle 12 (step S104). The imaging unit 27 transmits the generated second image G2 to the image processing device 31.

The determination unit 42 generates a difference image G3 between the first image G1 and the second image G2 (step S105). The determination unit 42 digitizes the shape of the nozzle hole 121 on the difference image G3 by applying image processing including the above-described fitting process to the difference image G3 (step S106). The determining unit 42 determines whether or not there is an abnormality in the nozzle 12 based on the numerically quantified feature amount regarding the shape of the nozzle hole 121 (step S107). The determining unit 42 determines that there is an abnormality in the nozzle 12 when the difference between the digitized feature amount regarding the shape of the nozzle hole 121 and a preset specified value exceeds a threshold value. Note that the feature amount related to the shape of the nozzle hole 121 includes, for example, one or more of the hole diameter R, the circularity D, and the oblateness f of the nozzle 12. If the difference between the digitized feature amount regarding the shape of the nozzle hole 121 and a preset specified value is equal to or less than a threshold value, the determination unit 42 determines that there is no abnormality in the nozzle 12 and ends the nozzle determination process.

If the determination unit 42 determines that there is an abnormality in the nozzle 12, the processing control unit 7 may stop the processing of the workpiece W by the laser processing machine 1 (step S108). For example, the processing control unit 7 communicates with the nozzle state determination device 11, and if the determination result of the process in step S107 performed by the nozzle state determination device 11 is a result indicating that the nozzle 12 is abnormal, the processing control unit 7 Cancel processing. If the determination unit 42 determines that the nozzle 12 is abnormal, the processing control unit 7 may instruct the replacement control unit 9 to cause the nozzle changer 8 to replace the nozzle 12 (step S109). The exchange control section 9 controls the nozzle changer 8 based on instructions from the processing control section 7. For example, when receiving an instruction from the processing control section 7, the replacement control section 9 controls the nozzle changer 8 to replace the nozzle 12 with a spare nozzle 12 after stopping laser processing.

In step S109, if the determination unit 42 determines that the nozzle 12 is abnormal, the processing control unit 7 may instruct the notification unit 10 to notify the user that the nozzle 12 should be replaced. The notification unit 10 notifies the user of information to the effect that the nozzle 12 should be replaced when there is an instruction from the processing control unit 7. In this case, the user may manually replace the nozzle 12.

The effects of the first embodiment will be explained below. The laser processing machine 1 melts a part of the workpiece W by outputting the processing laser beam L1 and assist gas from the nozzle hole 121 at the tip of the laser head 4, and melts a part of the workpiece W while removing the melted material with the assist gas. Laser process W. When the assist gas is oxygen, it also works to promote combustion. Here, when the nozzle hole 121 is a perfect circle or almost a perfect circle, the processing quality of laser processing is high. If the nozzle hole 121 is deformed due to the nozzle 12 being burned out by heat during laser processing or colliding with the workpiece W, the nozzle hole 121 may no longer be a perfect circle. When the nozzle hole 121 is deformed and is no longer a perfect circle, the effect of the assist gas becomes uneven, and the processing quality may vary depending on the processing direction. Further, if the opening area of the nozzle hole 121 becomes smaller due to the deformation of the nozzle hole 121, the amount of assist gas supplied may decrease and the processing quality may deteriorate.

Generally, it is required to select a nozzle 12 with an optimal hole diameter and attach it to the laser head 4 depending on the material of the workpiece W, the thickness of the workpiece W, and the type of assist gas. However, there may be cases where a user erroneously attaches a nozzle 12 with an inappropriate hole diameter to the laser head 4. Incorrect attachment of the nozzle 12 may not be discovered before laser processing is performed, but may be discovered after the laser processing has started when a processing defect occurs in the laser processing.

In order to solve this problem, it may be possible to install a new sensor outside the laser head to determine the nozzle status and determine the nozzle status based on the detection results of that sensor, but this would be costly. It becomes a factor of increase. Further, with the above-mentioned new sensor placed outside the laser head, if an abnormality occurs in the nozzle due to the structure inside the laser head, it may be difficult to appropriately determine the state.

In the laser processing machine 1 according to the first embodiment, the nozzle 12 is imaged by the imaging unit 27 when laser processing is not performed, and the shape of the nozzle hole 121 included in the image of the nozzle 12 captured by the imaging unit 27 The state of the nozzle 12 is determined based on. With these configurations, the state of the nozzle 12 can be determined without using a new sensor. As a result, deformation of the nozzle hole 121 and incorrect installation of the nozzle 12 can be detected without causing the above-mentioned cost increase. Further, the imaging unit 27 images the nozzle 12 by detecting the light emitted from the workpiece W through a part of the laser light passage space within the laser head 4 . That is, the image used to determine the state of the nozzle 12 in the first embodiment is not an image of the nozzle hole 121 taken from outside the laser head 4 but an image taken from inside the laser head 4. Therefore, if an abnormality occurs in the nozzle 12 due to the internal structure of the laser head 4, the laser processing machine 1 can detect the abnormality and appropriately determine the state of the nozzle 12. .

In the first embodiment, the laser processing machine 1 generates the first image G1 and the second image G2 using the first test plate Wt1 and the second test plate Wt2, but the invention is not limited to this. That is, the laser processing machine 1 only needs to be able to generate the first image G1 and the second image G2 by the imaging unit 27, and the generation method is not particularly limited. For example, the laser processing machine 1 may generate the first image G1 and the second image G2 using the illumination device 200 that emits the illumination light L3. FIG. 13 is a diagram showing a modification of the laser processing machine 1. For example, the laser processing machine 1 includes a lighting device 200. For example, the illumination device 200 is placed on the mounting table 51, and is arranged within at least one of the movement range Hx and the movement range Hy.

The illumination device 200 can emit illumination light L3 from below the nozzle 12 toward the nozzle hole 121. For example, the image processing device 31 is connected to the lighting device 200, and under the control of the image processing device 31, a first state in which the illumination light L3 is irradiated toward the nozzle hole 121 and a second state in which the illumination light L3 is not irradiated. Can be switched between states. When the laser head 4 is located above the illumination device 200, the imaging unit 27 images the nozzle 12 when the illumination device 200 is in the first state and the second state. That is, the imaging unit 27 generates the first image G1 by capturing an image when the illumination device 200 is in the first state. The imaging unit 27 generates the second image G2 by capturing an image when the illumination device 200 is in the second state. Note that in the second state, the illumination light L3 may be irradiated as long as the illuminance is lower than in the first state.

When using the illumination device 200, the laser processing machine 1 may determine the shape of the nozzle hole 121 using only the image captured in the first state. In the image captured in the first state in which the illumination light L3 is irradiated toward the nozzle hole 121, the contrast (brightness difference) between the nozzle 12 and the nozzle hole 121 is large, and the outline of the nozzle hole 121 may be sharp. Therefore, the determination unit 42 does not need to generate the difference image G3 between the first image G1 and the second image G2, and can apply the above image processing to the image of the nozzle 12 captured in the first state. The shape of the nozzle hole 121 may also be determined.

In the first embodiment, a dustproof mechanism such as a cover that can be opened and closed may be provided to cover the first test plate Wt1 and the second test plate Wt2. When generating the first image G1 and the second image G2, the dustproof mechanism is controlled to be in the open state.

In the first embodiment, the determination unit 42 may determine the state of the nozzle 12 based on one or more difference images G3, or may determine the state of the nozzle 12 based on a plurality of difference images G3. In this case, the determination unit 42 averages the feature amounts related to the shape of the nozzle hole 121 obtained based on each difference image G3, and compares the averaged feature amount related to the shape of the nozzle hole 121 with a specified value. The state of the nozzle 12 may be determined by this.

[Second embodiment]
A second embodiment will be described. In this embodiment, the same components as those in the above-described embodiment are given the same reference numerals, and the description thereof will be omitted or simplified. FIG. 14 is a diagram showing a laser processing machine 1A according to the second embodiment. A laser processing machine 1A according to the second embodiment emits a processing laser beam L1 to perform laser processing such as cutting and marking on a workpiece W to be processed. Here, the marking process of the second embodiment is a process of marking the surface of the workpiece W without forming a through hole, and by appropriately adjusting the output and frequency of the laser, only the surface of the workpiece is altered. (scorch), change the color to a color different from the original color of the workpiece W. A mark formed on the workpiece W by the marking process may be referred to as a "marking mark MK."

The laser processing machine 1A includes a laser oscillator 2, a laser head 4, an assist gas supply section 5, a head drive section 6, a processing control section 7A, a nozzle changer 8, an exchange control section 9, and a notification section 10A. , an actuator 60, an adjustment control section 61, and a misalignment detection device 62. The misalignment detection device 62 includes an illumination section 3, an observation optical system 14, an imaging section 27, and an image processing device 31A.

The processing control unit 7A controls the movement of the laser head 4 by controlling the head drive unit 6. For example, the processing control unit 7A acquires position information of the laser head 4 at a predetermined period, and controls movement of the laser head 4 by controlling the head drive unit 6 based on the acquired position information. Further, the processing control unit 7A controls the assist gas supply unit 5 to start injection of assist gas, and causes the laser oscillator 2 to output the processing laser beam L1, so that the irradiation optical system 13 applies the processing laser beam to the workpiece W. The laser beam L1 is irradiated.

The notification unit 10A is connected to the misalignment detection device 62. The notification unit 10A notifies the user of the information obtained from the misalignment detection device 62. For example, the notification unit 10A notifies the user of information regarding misalignment. The information regarding misalignment is, for example, either or both of information indicating that there is misalignment and information indicating the amount of misalignment (hereinafter referred to as "amount of misalignment"). Similar to the notification unit 10, the notification unit 10A may include, for example, a display unit or a speaker. However, the notification unit 10A is not limited thereto as long as it can notify the user of information regarding misalignment, and may, for example, notify the information regarding misalignment to the above-mentioned information terminal used by the user. The method of notification to the user by the notification unit 10A may be the same as that of the notification unit 10.

The actuator 60 automatically adjusts the position of the condensing lens 23. For example, the actuator 60 adjusts the position of the condenser lens 23 in a plane perpendicular to the optical axis of the condenser lens 23. By adjusting the position of the condenser lens 23, the center position (optical axis) of the processing laser beam L1 is adjusted. Adjustment control section 61 controls actuator 60 . The adjustment control unit 61 controls the actuator 60 to adjust the center position of the processing laser beam L1.

The image processing device 31A is, for example, an information processing device such as a computer. The image processing device 31A is connected to the processing control section 7A, and can exchange information with each other. The image processing device 31A is connected to the imaging section 27. The image processing device 31A is connected to the nozzle changer 8. FIG. 15 is a diagram illustrating an example of a functional unit of an image processing device 31A according to the second embodiment. The image processing device 31A includes, for example, a storage section 40, a processing state measurement section 41, a detection section 70, and an abnormality determination section 71.

The imaging unit 27 images the marking mark MK when laser processing is not being performed. The detection unit 70 detects the deviation of the center position Or of the laser beam with respect to the center position On of the nozzle hole 121, that is, the center position, based on the image G (hereinafter referred to as “image Gm”) of the marking mark MK captured by the imaging unit 27. Detect deviation. Here, the marking marks MK are formed on the surface of the third test plate Wm, for example, by performing a marking process on the third test plate Wm, which is the workpiece W for testing. 16 and 17 are diagrams showing an example of the arrangement of the third test plate Wm. FIG. 16 shows the arrangement of the third test plate Wm when viewed from above. FIG. 17 shows the arrangement of the third test plate Wm in a side view. Note that FIGS. 16 and 17 show a state in which the workpiece Wr for processing is carried into the processing area.

As shown in FIGS. 16 and 17, the laser processing machine 1A includes a movable pallet 50 and a mounting table 51A. The workpiece Wr to be laser-processed is carried into the processing area while being placed on the pallet 50A. The laser processing machine 1A performs laser processing on the processing workpiece Wr on the pallet 50 carried into the processing area. The third test plate Wm is placed on the mounting table 51A. The mounting table 51A is placed in the processing area. The third test plate Wm is arranged in at least one of the moving range Hx in the X direction and the moving range Hy in the Y direction of the laser head 4 when the pallet 50 is carried into the processing area.

When acquiring the image Gm, the laser processing machine 1A moves the laser head 4 above the third test plate Wm. Then, the laser processing machine 1A forms marking marks MK on the surface of the third test plate Wm by performing a marking process on the third test plate Wm. FIG. 18 is a diagram illustrating marking processing on the third test plate Wm. For example, the laser head 4 performs marking processing on the third test plate Wm one or more times. The processing control unit 7A manages the number of marking operations using a counter 72 or the like. Note that the numbers in parentheses shown in FIG. 18 are information indicating how many times the marking mark MK corresponding to the number was formed.

The processing control unit 7A controls the position (hereinafter referred to as "marking position") at which marking processing is performed on the third test plate Wm. The marking position is, for example, a position on the third test plate Wm in the XY plane. When the marking process is performed two or more times, the order in which the marking process is performed is set so that the marking process is not performed at the same location on the third test plate Wm.

For example, the processing control unit 7A calculates a marking position at which marking processing should be performed from the count value of the counter 72. The processing control unit 7A executes marking processing on the calculated marking position. That is, the processing control section 7A causes marking processing to be performed on the marking position according to the count value of the counter 72. However, the present invention is not limited to this, and for example, the processing control unit 7A may have marking information in which the number of times of marking is associated with the marking position.

The processing control unit 7A determines the number of markings to perform the next marking processing based on the count value of the counter 72, and acquires the marking position corresponding to the determined number of markings from the marking information. The processing control unit 7A performs marking processing on the acquired marking position. The intervals between the marking positions may be set at equal intervals that are not affected by past markings. Further, the marking positions may be arranged in a regular quadrangular lattice shape as shown in FIG. 19(A), or in a regular hexagonal lattice shape as shown in FIG. 19(B). The imaging unit 27 generates an image Gm of the marking mark MK by capturing an image of the marking mark MK. The imaging unit 27 transmits the generated image Gm to the image processing device 31A.

FIG. 20 is a diagram illustrating a method for detecting misalignment by the detection unit 70. The detection unit 70 executes image processing on the image Gm of the marking mark MK, and detects the center position Or of the laser beam on the image Gm of the marking mark MK. The center position Or of the laser beam is, for example, the center position of the marking mark MK. Image processing includes existing processing such as binarization, contour detection, ellipse or perfect circle fitting, for example. Further, the detection unit 70 detects the center position On of the nozzle hole 121 on the image captured by the imaging unit 27. The method of detecting the center position On by the detection unit 70 is the same as the method described in the first embodiment. Note that the image used to detect the center position On may be the image G of the marking mark MK, but is not limited to this, and may be an image other than the marking mark MK. The detection unit 70 determines a misalignment amount S, which is the deviation between the detected center position Or of the laser beam and the center position On of the nozzle hole 121.

The abnormality determination unit 71 determines whether the misalignment amount S detected by the detection unit 70 is equal to or greater than a prescribed threshold value Sth. The abnormality determination unit 71 determines that there is an abnormality when it is determined that the misalignment amount S is equal to or greater than a prescribed threshold value Sth. If the abnormality determination unit 71 determines that the abnormality is abnormal, the processing control unit 7A may stop the processing of the workpiece Wr by the laser processing machine 1A. When the abnormality determination unit 71 determines that the processing control unit 7A is abnormal, the processing control unit 7A adjusts the amount of adjustment of the position of the condenser lens 23 according to the amount of misalignment detected by the abnormality determination unit 71. The notification unit 10A may instruct the user to notify.

If the abnormality determination unit 71 determines that there is an abnormality, the processing control unit 7A instructs the adjustment control unit 52 to cause the abnormality determination unit 71 to automatically adjust the position of the condenser lens 23 according to the amount of misalignment. You may. For example, when instructing the adjustment control unit 52, the processing control unit 7A acquires information on the misalignment amount S from the abnormality determination unit 71, and transmits the acquired information on the misalignment amount S to the adjustment control unit 52. Alternatively, an adjustment amount corresponding to the acquired misalignment amount S may be transmitted to the adjustment control unit 52. When the adjustment control unit 52 receives the misalignment amount S, it controls the actuator 60 so that the misalignment amount S disappears. When the adjustment control unit 52 receives the adjustment amount, it controls the actuator 60 according to the adjustment amount.

The flow of misalignment detection processing will be explained below using FIG. 21. FIG. 21 is a flow diagram of the misalignment detection method. The detection unit 70 performs misalignment detection processing, for example, when the nozzle 12 is replaced by the nozzle changer 8. However, the timing to perform the misalignment detection process is not limited to this, and may be at the start of laser processing or at the end of laser processing. For example, when the detection unit 70 receives information indicating that the nozzle 12 has been replaced as information regarding the replacement of the nozzle 12 from the replacement control unit 9, the detection unit 70 may perform misalignment detection processing. For example, when the detection unit 70 receives information from the processing control unit 7A indicating that laser processing has started or that the laser processing has ended, the detection unit 70 may perform the misalignment detection process. The abnormality determination unit 71 may perform the misalignment detection process when a certain trigger signal is input.

When the image processing device 31A performs misalignment detection processing by the detection unit 70, first, it transmits second information indicating that to the processing control unit 32. When the processing control unit 32 receives the second information from the image processing device 31A, the processing control unit 32 controls the head drive unit 6 to mark the laser head 4 so that no through holes are formed on the surface of the third test plate Wm. Machining is executed (step S201). When the marking process is performed on the third test plate Wm by the laser head 4, the imaging unit 27 images the marking mark MK formed on the third test plate Wm by the marking process when the laser process is not performed. By doing so, an image Gm of the marking mark MK is generated (step S202). The imaging unit 27 transmits the generated image Gm of the marking mark MK to the image processing device 31A.

The detection unit 70 acquires an image Gm of the marking mark MK from the imaging unit 27. The detection unit 70 detects the center position Or of the processing laser beam L1 on the image Gm by applying image processing including perfect circle fitting to the acquired image Gm of the marking mark MK (step S203).

The detection unit 70 detects the misalignment amount S by determining the deviation between the detected center position Or of the processing laser beam L1 and the center position On of the nozzle hole 121 (step S204). Note that the detection unit 70 detects the center position On of the nozzle hole 121 by applying image processing including perfect circle fitting to the image of the nozzle 12 captured by the imaging unit 27 in advance. The abnormality determination unit 71 determines whether the amount of misalignment detected by the detection unit 70 is greater than or equal to the threshold value Sth (step S205).

The abnormality determination unit 71 determines that there is an abnormality when the misalignment amount S detected by the detection unit 70 is equal to or greater than the threshold value Sth. The processing control section 7A communicates with the abnormality determination section 71, and when the abnormality determination section 71 determines that there is an abnormality, the processing of the workpiece W by the laser processing machine 1A may be stopped (step S206). If the abnormality determination unit 71 determines that the process is abnormal, the processing control unit 7A instructs the notification unit 10A to notify the user of the adjustment amount of the position of the condenser lens 23 according to the amount of misalignment S. You can. The notification unit 10A notifies the user of the amount of adjustment of the condenser lens position according to the amount of misalignment when there is an instruction from the processing control unit 7A.

FIG. 22 is a diagram showing an example of a user interface (eg, GUI) of the laser processing machine 1A. For example, as illustrated in FIG. 22, a display screen 80 of information regarding processing conditions and centering adjustment is displayed on a display device (for example, notification section 10A) of the laser processing machine 1A as an example of a user interface. Ru. Centering refers to aligning the center position of the nozzle hole 121 with the center position of the processing laser beam. The display screen 80 has a first display area 81A and a second display area 81B. The processing conditions of the laser processing machine 1A are displayed in the first display area 81A. For example, the processing conditions include information such as the material of the processing workpiece Wr, the plate thickness, the focal length of the lens, the nozzle diameter, and the assist gas used for laser processing. These processing conditions are registered in a file, and are set in the laser processing machine 1A by operating the read button and reading the above file.

A centering adjustment method is displayed in the second display area 81B. For example, the laser head 4 is provided with an operation section that manually operates the actuator 60. This operating section includes a first operating section 82L and a second operating section 82R that adjust the center position (optical axis) of the processing laser beam L1 in the XY directions. Note that a first operating section 82L and a second operating section 82R are schematically shown in the second display area 81B. The second display area 81B shows a method of operating the operating unit to perform centering when centering is required, that is, when the amount of misalignment S is equal to or greater than the threshold value Sth.

In the example of FIG. 22, as a method of operating the operating section, which of the eight operating patterns P1 to P8 is used for centering is displayed. The second display area 81B also displays a determination result 83 of the process in step S208 (for example, "OK" or "NG") and an adjustment amount 84 of the position of the condenser lens 23 according to the amount of misalignment S. is displayed. For example, the amount of adjustment of the position of the condenser lens 23 according to the amount of misalignment S is the amount of operation of the operation section (for example, the amount of rotation 84L of the first operation section 82L and the amount of rotation 84R of the second operation section 82R). It is. In the example of FIG. 22, an operation pattern P8 in which only the first operation portion 82L is rotated to the left is selected as the centering adjustment method. Therefore, in this case, the amount of rotation of the first operating portion 82L is displayed as the amount of rotation 84L in the second display area 81B.

The effects of the second embodiment will be explained below. If the center position of the nozzle hole 121 and the center position of the processing laser beam do not match, that is, if misalignment occurs, the effect of the assist gas described in the first embodiment will not be uniform, and the processing will be difficult. Quality may vary depending on the processing direction. Therefore, it is required to detect misalignment and perform centering to correct the misalignment. By the way, in order to detect misalignment, image processing is performed on the image of the through hole formed in the workpiece by laser processing to determine the center position of the through hole (center position of the laser beam) and the center position of the nozzle hole 121. It is conceivable to detect the misalignment, which is the misalignment between the two. However, when a through hole is formed by laser machining, dross, which is a melt from the workpiece, may be ejected and adhere to the workpiece. Therefore, it is not possible to stably form a clean through hole whose center position can be accurately detected by the image processing described above, and therefore there is a problem that the detection accuracy of misalignment is poor.

In the second embodiment, misalignment is detected using an image Gm of a marking mark MK formed by marking the surface of the workpiece W without forming a through hole. With such a configuration, it is possible to suppress the ejection of dross, and it is possible to suppress a decrease in the detection accuracy of misalignment.

In the second embodiment, the laser processing machine 1A may prompt the user to replace the third test plate Wm when the count value of the counter 72 reaches a predetermined number. For example, the laser processing machine 1A may instruct the notification unit 10A to notify that the third test plate Wm is to be replaced when the count value of the counter 72 reaches a predetermined value.

In the second embodiment, the count value of the counter 72 may be reset manually by the user when replacing the third test plate Wm. Further, the count value of the counter 72 may be reset when replacement of the third test plate Wm is detected by a sensor (not shown).

In the second embodiment, a dustproof mechanism such as a cover may be provided to cover the third test plate Wm. When marking processing is performed, the dustproof mechanism is controlled to be in an open state. Furthermore, before the marking process is performed, gas may be sprayed onto the third test plate Wm to clean it.

In the second embodiment, the detection unit 70 calculates the amount of misalignment, which is the deviation between the center position Or of the processing laser beam L1 and the center position On of the nozzle hole 121, based on one or more images Gm. Often, the amount of misalignment may be calculated based on a plurality of images Gm. The detection unit 70 may average the amount of misalignment found based on each image Gm, and may use the averaged amount of misalignment as the final amount of misalignment.

[Third embodiment]
A third embodiment will be described. In this embodiment, the same components as those in the above-described embodiment are given the same reference numerals, and the description thereof will be omitted or simplified. FIG. 23 is a diagram showing a laser processing machine 1B according to the third embodiment. A laser beam machine 1B according to the third embodiment has the functions of the laser beam machine 1 of the first embodiment and the functions of the laser beam machine 1A of the second embodiment. The laser processing machine 1B determines whether there is an abnormality in the nozzle 12 and detects misalignment. The laser processing machine 1B emits a processing laser beam L1 to perform laser processing such as cutting and marking on a workpiece W to be processed. Here, the marking process in the third embodiment is similar to that in the second embodiment, and marking marks MK are formed on the surface of the workpiece W.

The laser processing machine 1B includes a laser oscillator 2, a laser head 4, an assist gas supply section 5, a head drive section 6, a processing control section 7B, a nozzle changer 8, an exchange control section 9, and a notification section 10B. , an actuator 60, an adjustment control section 61, and an image processing system 100. The image processing system 100 includes an illumination section 3, an observation optical system 14, an imaging section 27, and an image processing device 31B. The image processing system 100 is an example of a nozzle state determination device or misalignment detection device of the present invention.

The processing control section 7B controls the movement of the laser head 4 by controlling the head drive section 6. For example, the processing control unit 7B acquires position information of the laser head 4 at a predetermined period, and controls movement of the laser head 4 by controlling the head drive unit 6 based on the acquired position information. Further, the processing control section 7B controls the assist gas supply section 5 to start injection of assist gas, and causes the laser oscillator 2 to output the processing laser beam L1, so that the irradiation optical system 13 applies the processing laser beam to the workpiece W. The laser beam L1 is irradiated.

The notification unit 10B is connected to the image processing device 31B. The notification unit 10B notifies the user of information obtained from the image processing device 31B. For example, the notification unit 10B notifies the user of information regarding replacement of the nozzle 12 and information regarding misalignment. Similar to the notification unit 10, the notification unit 10B may include, for example, a display unit or a speaker. However, the notification unit 10B is not limited thereto as long as it can notify the user of information regarding replacement of the nozzle 12 and information regarding misalignment, and may notify the above-mentioned information terminal used by the user, for example. The method of notification to the user by the notification unit 10B may be the same as that of the notification unit 10.

The image processing system 100 includes, for example, an imaging unit 27 and an image processing device 31B. The image processing device 31B is, for example, an information processing device such as a computer. The image processing device 31B is connected to the processing control section 7B and can exchange information with each other. The image processing device 31B is connected to the imaging section 27. The image processing device 31B is connected to the nozzle changer 8. The image processing device 31B is connected to the notification section 10B. The image processing device 31B has the functions of the image processing device 31 of the first embodiment and the functions of the image processing device 31A of the second embodiment. FIG. 24 is a diagram illustrating an example of a functional unit of an image processing device 31B according to the third embodiment. The image processing device 31B includes, for example, a storage section 40, a machining state measuring section 41, a determining section 42, a detecting section 70, and an abnormality determining section 71.

The machining state measuring section 41, the determining section 42, the detecting section 70, and the abnormality determining section 71 are realized, for example, by a hardware processor such as a CPU executing a program (software). Further, some or all of these components may be realized by hardware (including circuitry) such as LSI, ASIC, FPGA, GPU, etc., or may be realized by collaboration of software and hardware. may be done.

25 and 26 show a state in which the workpiece Wr for processing is carried into the processing area. As shown in FIGS. 25 and 26, the laser processing machine 1B includes a movable pallet 50 and a mounting table 51B. The laser processing machine 1B has a mounting table 51B. The mounting table 51B is arranged in the processing area, and the first test plate Wt1, the second test plate Wt2, and the third test plate Wm are mounted on the mounting table 51B. The first test plate Wt1, the second test plate Wt2, and the third test plate Wm are arranged at least within the moving range Hx in the X direction and the moving range Hy in the Y direction of the laser head 4 when the pallet 50 is carried into the processing area. placed in either. Further, the first test plate Wt1, the second test plate Wt2, and the third test plate Wm are adjacent to each other and arranged side by side in the X direction.

Below, the flow of operation of the laser processing machine 1B according to the third embodiment will be explained using FIG. 27. FIG. 27 is a flow diagram of the operation of the laser processing machine 1B according to the third embodiment. The laser processing machine 1B first executes a nozzle determination process. The processes in steps S301 to S309 regarding the nozzle determination process are the same as those in steps S101 to S109, so a description thereof will be omitted.

If the nozzle 12 is replaced manually or automatically by performing the process in step S309, the image processing device 31B moves to the process in step S311 and starts the misalignment determination process. On the other hand, if it is determined in the process of step S307 that there is no abnormality in the nozzle 12, the image processing device 31B moves to the process of step S311 and starts the misalignment determination process at the timing of performing the misalignment determination process. do. For example, if it is determined that there is no abnormality in the nozzle 12 in the process of step S307, and the timing to perform the misalignment detection process has arrived (step S310: YES), the image processing device 31B performs the process of step S311. to move to. The timing of performing the misalignment detection process may be, for example, the timing at which the nozzle 12 is replaced, or may be performed at the time of machining the workpiece W2.

The processing from step S311 to step S316 is the same as the processing from step S201 to step S205 and step S207, so a description thereof will be omitted. Here, in the process of step 314, that is, in detecting the amount of misalignment, the detection unit 70 applies image processing including perfect circle fitting to the first image G1 or the second image G2 captured in the nozzle state determination process. By doing so, the center position On of the nozzle hole 121 may be detected in advance. Further, the detection unit 70 may acquire the center position On of the nozzle hole 121 from the determination unit 42.

According to the third embodiment, the same effects as the first and second embodiments can be achieved. That is, the laser processing machine 1B is capable of executing nozzle determination processing and misalignment determination processing, appropriately determines the state of the nozzle 12 of the laser head 4, and suppresses a decrease in misalignment detection accuracy. be able to.

In the third embodiment, the laser processing machine 1B uses three test plates: a first test plate Wt1, a second test plate Wt2, and a third test plate Wm, but the present invention is not limited thereto. For example, the laser processing machine 1B may perform the nozzle determination process and the misalignment detection process using two test plates, the first test plate Wt1 and the second test plate Wt2. As an example, after the laser processing machine 1B generates the first image G1 and the second image G2 using the first test plate Wt1 and the second test plate Wt2, it Marking processing may also be performed on the material.

<Additional notes>
The above embodiments disclose at least the following configurations.
(Configuration 1)
A nozzle state determination device for determining the state of a nozzle of a laser head in a laser processing machine that processes a workpiece with a laser beam emitted from a laser head,
an imaging unit that captures an image of the workpiece by detecting light emitted from the workpiece during processing of the workpiece through a part of a laser light passage space within the laser head;
a determination unit that determines the state of the nozzle;
Equipped with
The imaging unit images the nozzle when the laser processing machine is not processing the nozzle with the laser beam,
The determination unit determines the state of the nozzle based on the shape of the nozzle included in the image of the nozzle captured by the imaging unit.
Nozzle condition determination device.
(Configuration 2)
The imaging unit captures a first image of the nozzle and a second image of the nozzle having a brightness different from that of the first image,
The determination unit generates a difference image between the first image and the second image, and determines the state of the nozzle based on the difference image.
The nozzle state determination device according to configuration 1.
(Configuration 3)
Equipped with a lighting section that generates illumination light,
The first image is an image generated by the illumination light reflected by the first test plate being detected by the imaging unit,
The second image is an image generated by the imaging unit detecting the illumination light reflected by a second test plate having a different reflectance from the first test plate.
The nozzle state determination device according to configuration 1 or configuration 2.
(Configuration 4)
The determining unit determines that when the shape of the nozzle based on the image captured by the imaging unit exceeds a predetermined range preset with respect to the initial shape of the nozzle used for processing the workpiece, It is determined that there is an abnormality in the nozzle.
A nozzle state determination device according to any one of configurations 1 to 3.
(Configuration 5)
The laser processing machine includes a nozzle changer that automatically replaces the nozzle,
The determination unit acquires information regarding the nozzle replacement performed by the nozzle changer, and determines the state of the nozzle before and after the nozzle replacement.
The nozzle state determination device according to configuration 4.
(Configuration 6)
The determination unit determines a state of the nozzle when processing the workpiece by the laser processing machine.
A nozzle state determination device according to any one of configurations 1 to 5.
(Configuration 7)
The determination unit executes an ellipse fitting process on the image of the nozzle captured by the imaging unit, or a perfect circle fitting process on the image of the nozzle captured by the imaging unit, and performs the process on the nozzle image captured by the imaging unit, and performs the determining at least one of the hole diameter, circularity, and oblateness of the nozzle;
A nozzle state determination device according to any one of configurations 1 to 6.
(Configuration 8)
the laser head that emits a laser beam from a nozzle and processes the workpiece with the laser beam;
a nozzle state determination device according to any one of configurations 1 to 7, which determines the state of the nozzle of the laser head;
Equipped with
Laser processing machine.
(Configuration 9)
a nozzle changer that automatically replaces the nozzle; a replacement control unit that controls replacement of the nozzle by the nozzle changer;
a processing control unit that instructs the replacement control unit to cause the nozzle changer to replace the nozzle when the nozzle condition determination device determines that the nozzle is abnormal;
The laser processing machine according to configuration 8, comprising:
(Configuration 10)
a nozzle changer that automatically replaces the nozzle;
a notification unit that notifies a user of information regarding replacement of the nozzle;
a processing control unit that instructs the notification unit to notify that the nozzle should be replaced when the nozzle condition determination device determines that the nozzle is abnormal;
The laser processing machine according to configuration 8 or configuration 9, comprising:
(Configuration 11)
comprising a processing control unit that stops processing the workpiece when the nozzle condition determination device determines that the nozzle is abnormal;
The laser processing machine according to any one of configurations 8 to 10.
(Configuration 12)
The laser head performs marking processing on the surface of the workpiece using the laser beam,
An image of a marking mark formed on the workpiece by the marking process, which is an image taken by the imaging unit included in the nozzle state determination device, and information regarding the center position of the nozzle hole that has been acquired in advance. a detection unit that detects a misalignment of the center position of the laser beam with respect to the center position of the hole of the nozzle based on the above;
The laser processing machine according to any one of configurations 8 to 11.

Furthermore, the above embodiments further disclose at least the following configurations.
(Configuration 13)
The laser beam in a laser processing machine equipped with a laser oscillator that generates a laser beam for processing, and a laser head that accommodates a condensing lens that focuses the laser beam generated by the laser oscillator and irradiates it onto a workpiece. A misalignment detection device for detecting misalignment of
an imaging unit that captures an image of the workpiece by detecting light emitted from the workpiece during processing of the workpiece through a part of a laser light passage space within the laser head;
an image captured by the imaging unit of a marking mark formed on the workpiece by marking processing that does not form a through hole on the workpiece; and a pre-obtained center position of the nozzle hole of the laser head. an image processing device that detects the misalignment of the laser beam based on information about the laser beam;
A misalignment detection device comprising:
(Configuration 14)
The laser processing machine includes a nozzle changer that automatically changes the nozzle of the laser head,
The image processing device acquires information regarding the nozzle replacement performed by the nozzle changer, and detects the misalignment before and after the nozzle replacement by the nozzle changer.
The misalignment detection device according to configuration 13.
(Configuration 15)
The image processing device detects the misalignment when processing the workpiece by the laser processing machine.
The misalignment detection device according to configuration 13 or configuration 14.
(Configuration 16)
The image processing device calculates a center position of the laser beam from the image of the marking trace, and detects a deviation of the center position of the laser beam with respect to a center position of the nozzle hole as the center deviation.
The misalignment detection device according to any one of configurations 13 to 15.
(Configuration 17)
the laser oscillator that generates a laser beam for processing;
the condensing lens that condenses the laser light generated by the laser oscillator and irradiates the workpiece;
The misalignment detection device according to any one of configurations 13 to 16;
A laser processing machine equipped with
(Configuration 18)
comprising a processing control unit that stops processing the workpiece by the laser processing machine when the amount of the misalignment detected by the misalignment detection device is equal to or greater than a specified value;
The laser processing machine according to configuration 17.
(Configuration 19)
a notification unit that notifies a user of information regarding the misalignment;
When the amount of misalignment detected by the misalignment detection device is equal to or greater than a predetermined threshold, the notification unit notifies the amount of adjustment of the position of the condenser lens according to the amount of misalignment. A processing control unit that gives instructions;
The laser processing machine according to configuration 17 or configuration 18, comprising:
(Configuration 20)
an actuator that adjusts the position of the condensing lens; an adjustment control unit that controls the actuator;
If the amount of misalignment detected by the misalignment detection device is equal to or greater than a predetermined threshold, instruct the adjustment control unit to adjust the position of the condenser lens according to the amount of misalignment. a processing control section;
The laser processing machine according to any one of configurations 17 to 19, comprising:
(Configuration 21)
The actuator adjusts the position of the condenser lens in a plane perpendicular to the optical axis of the condenser lens.
The laser processing machine according to configuration 20.

Although the embodiments have been described above, the technical scope of the present invention is not limited to the embodiments described above. Furthermore, it will be apparent to those skilled in the art that various changes or improvements can be made to the embodiments described above. It is clear from the claims that forms with such changes or improvements may also be included within the technical scope of the present invention. Furthermore, one or more of the requirements described in the embodiments described above may be omitted. Further, the requirements described in the above embodiments can be combined as appropriate. Moreover, the execution order of each procedure shown in the embodiment can be implemented in any order as long as the result of the previous procedure is not used in the subsequent procedure. Further, even if the operations in the above-described embodiments are described using "first", "next", "successively", etc. for convenience, it is not essential that they be performed in this order.

1, 1A, 1B... Laser processing machine 2... Laser oscillator 3... Illumination unit 4... Laser head 7... Processing control unit 8... Nozzle changer 9... Replacement control unit 10 , 10A, 10B...Notification section 11...Nozzle state determination device 12...Nozzle 27...Imaging section 31, 31A, 31B...Image processing device 42...Judgment section 50...Actuator 60... Actuator 61... Adjustment control unit 62... Misalignment detection device 70... Detection unit Wt1... First test plate Wt2... Second test plate Wm... Third test plate

Claims (13)

A nozzle state determination device for determining the state of a nozzle of a laser head in a laser processing machine that processes a workpiece with a laser beam emitted from a laser head,
an imaging unit that captures an image of the workpiece by detecting light emitted from the workpiece during processing of the workpiece through a part of a laser light passage space within the laser head;
a determination unit that determines the state of the nozzle;
Equipped with
The imaging unit images the nozzle when the laser processing machine is not processing the nozzle with the laser beam,
The determination unit determines the state of the nozzle based on the shape of the nozzle included in the image of the nozzle captured by the imaging unit.
Nozzle condition determination device. The imaging unit captures a first image of the nozzle and a second image of the nozzle having a brightness different from that of the first image,
The determination unit generates a difference image between the first image and the second image, and determines the state of the nozzle based on the difference image.
The nozzle state determination device according to claim 1. Equipped with a lighting section that generates illumination light,
The first image is an image generated by the illumination light reflected by the first test plate being detected by the imaging unit,
The second image is an image generated by the imaging unit detecting the illumination light reflected by a second test plate having a different reflectance from the first test plate.
The nozzle state determination device according to claim 2. The determining unit determines that when the shape of the nozzle based on the image captured by the imaging unit exceeds a predetermined range preset with respect to the initial shape of the nozzle used for processing the workpiece, It is determined that there is an abnormality in the nozzle.
The nozzle state determination device according to claim 1. The laser processing machine includes a nozzle changer that automatically replaces the nozzle,
The determination unit acquires information regarding the nozzle replacement performed by the nozzle changer, and determines the state of the nozzle before and after the nozzle replacement.
The nozzle state determination device according to claim 4. The determination unit determines a state of the nozzle when processing the workpiece by the laser processing machine.
The nozzle state determination device according to claim 1. The determination unit executes an ellipse fitting process on the image of the nozzle captured by the imaging unit, or a perfect circle fitting process on the image of the nozzle captured by the imaging unit, and performs the process on the nozzle image captured by the imaging unit, and performs the determining at least one of the hole diameter, circularity, and oblateness of the nozzle;
The nozzle state determination device according to claim 1. the laser head that emits a laser beam from a nozzle and processes the workpiece with the laser beam;
The nozzle state determination device according to any one of claims 1 to 7, which determines the state of the nozzle of the laser head;
Equipped with
Laser processing machine. a nozzle changer that automatically replaces the nozzle;
an exchange control unit that controls exchange of the nozzle by the nozzle changer;
a processing control unit that instructs the replacement control unit to cause the nozzle changer to replace the nozzle when the nozzle condition determination device determines that the nozzle is abnormal;
The laser processing machine according to claim 8, comprising: a nozzle changer that automatically replaces the nozzle;
a notification unit that notifies a user of information regarding replacement of the nozzle;
a processing control unit that instructs the notification unit to notify that the nozzle should be replaced when the nozzle condition determination device determines that the nozzle is abnormal;
The laser processing machine according to claim 8, comprising: comprising a processing control unit that stops processing the workpiece when the nozzle condition determination device determines that the nozzle is abnormal;
The laser processing machine according to claim 8. The laser head performs a marking process on the surface of the workpiece using the laser beam,
An image of a marking mark formed on the workpiece by the marking process, which is an image taken by the imaging unit provided in the nozzle state determination device, and information regarding the center position of the hole of the nozzle obtained in advance. a detection unit that detects a misalignment of the center position of the laser beam with respect to the center position of the hole of the nozzle,
The laser processing machine according to claim 8. A nozzle state determination method for determining the state of a nozzle of a laser head in a laser processing machine that processes a workpiece with a laser beam emitted from a laser head, the method comprising:
The laser processing machine includes an imaging unit that captures an image of the workpiece by detecting light emitted from the workpiece during processing of the workpiece through a part of a laser light passage space in the laser head,
capturing an image of the nozzle with the imaging unit when processing with the laser beam is not being performed;
determining a state of the nozzle based on a shape of the nozzle included in an image of the nozzle captured by the imaging unit;
A nozzle condition determination method, including:

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