JP6194464B1 - Method for determining nozzle life of laser processing machine and laser processing machine - Google Patents

Abstract

In a laser processing machine, it is possible to effectively determine the wear and deterioration of a nozzle that needs to be replaced. Nozzle life of a laser processing machine having a nozzle (26b) for injecting a liquid to form a columnar liquid flow, introducing a laser beam into the nozzle and irradiating the workpiece with the laser beam. In the determination method, each time the laser alignment adjustment is performed, the nozzle image captured by the alignment camera 32 is displayed on the input / display unit 120 of the laser processing machine, and the nozzle image subjected to the alignment adjustment is stored together with the attribute data. The camera image of the normal nozzle and the camera image of the current nozzle are displayed side by side on the input / display unit together with the attribute data so that it can be visually determined whether or not the current nozzle can be used. [Selection] Figure 2

Description

  The present invention includes a nozzle that ejects liquid to form a columnar liquid flow, and irradiates the workpiece placed on the table with laser light from an optical head that irradiates the nozzle with laser light. The present invention relates to a nozzle life determination method for a water jet laser processing machine that processes the nozzle and a laser processing machine capable of performing the nozzle life determination method.

  In a water jet laser processing machine that processes a workpiece through laser light in a columnar liquid flow formed by ejecting liquid from a nozzle, the optical axis of the laser light must be aligned with the central axis of the liquid flow. Patent Document 1 discloses a laser processing apparatus including a camera for observing the vicinity of a nozzle in order to perform alignment adjustment in which the optical axis of laser light coincides with the central axis of a liquid flow.

  In the laser processing machine, the nozzle hole is gradually damaged by the heat of the laser beam being processed, and the inner diameter becomes larger than the reference dimension or the inner surface of the nozzle hole is cracked. In addition, the spatter scattered from the workpiece collides with or adheres to the nozzle, and the shape of the nozzle hole becomes distorted. In this way, in the laser processing machine, the columnar liquid flow discharged from the nozzle becomes turbulent and becomes turbulent flow instead of laminar flow due to damage and deterioration of the nozzle as time passes for processing. Laser light emitted from the side surface of the liquid flow increases, and proper laser processing cannot be performed.

JP 2001-287071 A

  Therefore, when the nozzle is damaged or deteriorated, it is necessary to replace it with a new nozzle. For example, if the nozzle is replaced when a processing defect occurs, the workpiece that has become defective is wasted. Thus, since the laser processing machine must be stopped once, the processing efficiency decreases.

  The present invention has a technical problem to solve such problems of the prior art, and provides a nozzle life determination method and a laser beam machine capable of effectively determining the wear and deterioration of a nozzle that requires replacement. It is an object.

  In order to achieve the above-described object, according to the present invention, there is provided a nozzle life determination method for a water jet laser processing machine for laser processing a workpiece by introducing a laser beam into a water jet formed by jetting water from a nozzle. This is an alignment camera that is provided in the optical head that irradiates the laser beam and images the nozzle hole from the upstream side of the laser beam path. The normal nozzle hole is imaged in a state where a water jet is ejected and the image is stored. Then, the nozzle hole after use is imaged with the water jet jetted by the alignment camera, and the stored normal nozzle hole image and the nozzle hole image after use are displayed side by side, based on the difference of the image data Thus, there is provided a nozzle life determination method for a laser beam machine that performs nozzle life determination.

According to another feature of the present invention, in a laser processing machine for processing a workpiece placed on a table by irradiating the workpiece with a laser beam, a nozzle for jetting water to form a water jet, and a laser on the nozzle An optical head having an optical system for introducing light, an alignment camera that captures an image of the nozzle hole, a display unit that displays an image of the nozzle hole captured by the alignment camera, and a nozzle hole captured by the alignment camera embedded attribute data to the image data of the image file generation unit that generates an image file, a storage unit for storing the image file by the camera image acquisition button displayed on the screen of the nozzle hole image of the display unit, said storage unit Image files generated from normal nozzle camera images, and after use Laser beam machine and a display processing unit for displaying on the display unit a plurality of image files including the image file generated from nozzle camera images are arranged in time series is provided.

  According to the present invention, by displaying at least the camera image of the normal nozzle and the camera image of the nozzle after use on the display device, the operator can use the current nozzle based on his / her experience. It is possible to visually determine whether or not the nozzle needs to be replaced.

1 is a schematic diagram illustrating an example of an optical head of a laser beam machine to which the present invention is applied. It is a block diagram of the nozzle observation apparatus by preferable embodiment of this invention. It is the schematic of the nozzle observation window for observing the state of the nozzle displayed on an input and a display part, and is a figure which shows the nozzle immediately after replacement | exchange. It is the schematic of the nozzle observation window similar to FIG. 3, and is a figure which shows the nozzle after using for laser processing. FIG. 5 is a schematic view of a nozzle observation window similar to FIG. 3, showing a nozzle whose inner peripheral surface is damaged or deteriorated as time passes from the state of FIG. 4. FIG. 6 is a schematic view of a nozzle observation window similar to that in FIG. 3, and shows images of the nozzles shown in FIGS. 3 to 5 arranged in time series. It is a flowchart which shows an example of the nozzle life determination method of this invention.

  Referring to FIG. 1, an example of an optical head of a laser processing machine to which the present invention is applied is shown. The optical head 10 is provided in a housing 12 and includes a laser irradiation head 16 that receives laser light from a laser oscillator 14 via a light guide member 14 a such as an optical fiber and irradiates the collimation lens 18. Yes. The laser light from the laser irradiation head 16 is converted into parallel rays by the collimation lens 18, reflected by the first mirror 20 toward the second mirror 22, and directed toward the focus lens 24 by the second mirror 22. Reflected. The laser light focused by the focus lens 24 is irradiated to the outside of the housing 12 through the nozzle head 26 toward the table (not shown) of the laser processing machine that fixes the workpiece. At this time, the optical axis of the laser beam irradiated by the optical head 10 is substantially parallel to the Z axis. In addition, the table which solidifies a workpiece | work is provided so that the optical head 10 may be faced, and the optical head 10 can be relatively moved with respect to the table in the three directions of X, Y, and Z.

  The first and second mirrors 20 and 22 have a planar reflecting surface, and the direction of the reflecting surface (the direction perpendicular to the reflecting surface) is adjusted, and the direction of the laser light emitted from the optical head 10 The motors 20a and 22a are provided as mirror orientation changing means for adjusting the angle. The first and second mirrors 20 and 22, particularly the second mirror 22 that reflects the laser light toward the focus lens 24, are adapted to the wavelength of the laser light emitted from the laser oscillator 14, and the laser light is A dielectric multilayer film that reflects and transmits light having a wavelength other than the wavelength of the laser light is included. More specifically, the dielectric multilayer film is deposited on a glass plate. By forming the second mirror 22 from a dielectric multilayer film, the positional relationship between the laser light emitted from the nozzle 26 b and the nozzle 26 b can be observed by the alignment camera 32. Hereinafter, the alignment camera is simply referred to as a camera.

  The nozzle head 26 is a hollow member that receives supply of water from the water supply source 30 via the pipe line 28. A nozzle 26b for ejecting a water jet is provided on the bottom wall of the nozzle head 26, and a window 26a made of a transparent member such as glass is provided on the upper surface facing the focus lens 24 on the opposite side of the bottom wall. The nozzle 26 b communicates with the outside of the housing 12 through an orifice 12 b formed on the bottom surface of the housing 12 of the optical head 10.

  Referring to FIG. 2, a nozzle observation apparatus 100 according to a preferred embodiment of the present invention includes a camera 102, a camera image acquisition unit 104, a display screen acquisition unit 106, an image file generation unit 108, a built-in storage unit 112, a display processing unit 118, and An input / display unit 120 is provided as a main component. The camera image acquisition unit 104, the display screen acquisition unit 106, and the image file generation unit 108 use the CPU and the memory of the NC device of the laser processing machine in hardware, and the control program for the NC device in software It can be formed as a part of The built-in storage unit 112 can be formed by a storage area allocated to a RAM, a flash memory, a hard disk, or the like of the NC device of the laser processing machine.

  The camera 102 can be formed by the camera 32 built in the optical head 10 for the laser beam alignment adjustment described above. The input / display unit 120 can be formed, for example, from a touch panel as a display device attached to the operation panel of the laser beam machine.

  The camera image acquisition unit 104 acquires data of an image currently captured by the camera 102 from the camera 102 by tapping or clicking a camera image acquisition button displayed on the touch panel constituting the input / display unit 120. The image data acquired by the camera image acquisition unit 104 is output from the camera image acquisition unit 104 to the image file generation unit 108.

  The image file generation unit 108 embeds attribute data in the image data from the camera image acquisition unit 104 and generates an image file such as TIFF (Tagged Image File Format). The attribute data may include an identification symbol of the nozzle head 26 (nozzle 26b), an image capturing date and time, an operator name, a workpiece material, a processing method, an evaluation result of wear by the operator, and the like. The identification symbol of the nozzle head 26 (nozzle 26b), the image capturing date and time, the name of the operator, the workpiece material, and the processing method can be acquired from the machine information storage unit 110, for example. The machine information storage unit 110 can be formed from, for example, a memory area built in an NC device of a laser processing machine. The attribute data is collected from the machining program by interpreting the machining program read by the NC device of the laser beam machine, input manually by the operator prior to machining, or via a computer network such as a LAN. Can be collected from servers and CAM systems.

  The generated image file is stored in the built-in storage unit 112 of the nozzle observation apparatus 100. Data in the built-in storage unit 112 can be output to an external storage unit 116 such as a USB memory via an appropriate output port 114 such as a USB (Universal Serial Bus). Alternatively, the output port 114 and the external storage unit 116 may be replaced by a computer network such as a LAN and a server connected to the computer network. By storing the image file in which the attribute data is embedded in the image data in the external storage unit 116, it is possible to easily provide accurate information on the laser processing machine to the service person of the laser processing machine, and the maintenance and repair are efficiently performed. Can be done efficiently and appropriately

  The image data acquired by the camera image acquisition unit 104 is output to the display processing unit 118, and the image of the nozzle 26 b captured by the camera 102 is displayed on the input / display unit 120. 3 to 6 illustrate images of the nozzles 26b displayed on the input / display unit 120. FIG. 3 to 6 show a nozzle observation window for observing the state of the nozzle 26b as an example. In particular, in FIG. 3, the nozzle 26 b immediately after replacement captured by the alignment adjustment camera 32 is superimposed on the target circle 50 used in the alignment adjustment work and displayed on the nozzle observation window of the input / display unit 120. At this time, the diameter of the target circle 50 is set to a size that matches the allowable wear inner diameter of the nozzle 26b. Accordingly, the nozzle 26b immediately after the replacement is not yet worn and is smaller than the target circle 50.

  FIG. 4 shows an image of the nozzle 26b after being subjected to processing for a certain time after replacement. The state of the nozzle 26b in FIG. 4 is slightly larger in inner diameter than the nozzle 26b in FIG. In this state, the nozzle 26b is still usable. FIG. 5 shows the nozzle 26b in which the processing time has further passed and the inner diameter is considerably larger than the target circle 50, and the inner peripheral surface is damaged and deteriorated.

  Further, FIG. 6 shows a screen on which images of the nozzles 26b shown in FIGS. 3 to 5 are arranged and displayed in time series. As described above, by displaying the images of the nozzles 26b individually or by displaying a plurality of images in time series, the operator can visually determine whether or not the nozzles (nozzle heads 26) need to be replaced based on experience. A reference image to be determined that the currently mounted nozzle 26b (nozzle head 26) should be replaced due to wear and a description of the determination criterion are displayed as text in the nozzle observation window together with the image of the nozzle 26b. May be. Of course, the skilled operator can determine the life by using only the nozzle images arranged in time series.

  The acquisition of the camera image of the nozzle 26b and the storage of the image file can be performed, for example, at the time of alignment adjustment work performed with laser processing. Referring to the nozzle replacement necessity determination flowchart shown in FIG. 7, when the nozzle (nozzle head 26) is replaced with a new nozzle (nozzle head 26) (step S10), the nozzle of the new nozzle 26b that is not used for this processing A hole is imaged by the camera 102 (32) and the image is stored (step S12). Next, laser processing is performed using the replaced new nozzle 26b (step S14). In the preceding stage of step S12, the movement to the laser alignment adjustment position and the start of laser alignment adjustment in steps S18 and S20 described later are performed, but the description thereof is omitted.

  In step S14, it is determined whether a predetermined time has elapsed after laser processing (step S16). By this step, for example, the nozzle life is determined at a good timing after 10 hours. If the predetermined time has not elapsed (No in step S16), the process returns to step S14 and laser processing is continued. When the predetermined time has elapsed (Yes in Step S), the optical head 10 moves to the laser alignment adjustment position in order to perform laser beam alignment adjustment (Step S18). The alignment adjustment can be performed when the machining time accumulated from the previous alignment adjustment becomes a constant value, or when a predetermined number of machining processes are executed.

  In the alignment adjustment, the laser spot generated in the hole of the nozzle 26 b and the upper surface of the nozzle head 26 is imaged in a state where the water jet is ejected by the camera 32 built in the optical head 10, and the image is input to the input / display unit 120. The first and second mirrors 20 are driven by driving the motors 20a and 22a so that the optical axis (laser spot) of the laser beam coincides with the center of the nozzle 26b by manual operation while the operator visually observes it. , 22 are adjusted (step S20).

  When the operator taps or clicks the camera image acquisition button 40 in the nozzle observation window displayed on the input / display unit 120 during the alignment adjustment operation, the camera image acquisition unit 104 displays the image from the camera 102 (32). The data is output to the image file generation unit 108. At this time, not the camera image acquisition button 40 but the display screen acquisition button 42 is displayed in the window, and the screen currently displayed on the input / display unit 120 is displayed by tapping or clicking the display screen acquisition button 42. As with the print screen, the image may be acquired by the display screen acquisition unit 106 and output to the image file generation unit 108 as image data.

  The image file generated by the image file generation unit 108 based on the new image data is stored in the built-in storage unit 112, and as an image of only the current nozzle 26b as shown in FIGS. As shown in FIG. 5, a plurality of images including at least the image of the nozzle 26 b immediately after the replacement of the nozzle head 26 are displayed on the input / display unit 120 as a normal nozzle camera image. Thus, the operator can determine whether or not the current nozzle 26b can be used for processing (step S24). If it is determined in step S24 that the operator has reached the end of the life of the nozzle 26b (Yes in step S24), in step S26, the operator makes an input indicating that the determination result is not possible, and the nozzle is replaced (step S28). . The determination of the life of the nozzle can be performed based on, for example, a difference in image data.

  In step S24, if the operator determines that the nozzle 26b is slightly damaged or deteriorated and is usable (No in step S24), in step S30, the operator makes an input indicating that the nozzle 26b can be used according to the determination result. The alignment adjustment is completed (step S32). The input indicating that the nozzle can be used in step S30 is, for example, that three stars are input when the shape of the nozzle 26b is very good close to a new one, and the nozzle 26b is somewhat deteriorated. In some cases, two stars may be input, and in a state where the use is possible but the exchange time is approaching, one star may be input. And it returns to step S14 and laser processing is continued.

  In the flowchart of FIG. 7, the start and stop of the water supply from the water supply source 30 are omitted, but the supply of water is stopped immediately before step S10, the supply of water is started immediately after, and then the nozzle The water supply continues until it is replaced. In the state where the nozzle head 26 is filled with water and the state where water is not supplied, the position of the nozzle 26b slightly changes, and if water is not supplied, water droplets adhere to the back surface of the transparent window 26a. As a result, the image of the nozzle hole becomes unclear. In order to prevent this, in the present invention, the nozzle hole is imaged in a state where a water jet is ejected. Then, the position of the nozzle is always constant, the magnification of the inner diameter of the nozzle hole in the image is the same, the size of the plurality of nozzle holes can be compared and evaluated as they are, and a clear image that is not subject to the state of water droplets is obtained. be able to.

DESCRIPTION OF SYMBOLS 10 Optical head 20 1st mirror 22 2nd mirror 26 Nozzle head 26b Nozzle 30 Water supply source 32 Alignment camera 40 Camera image acquisition button 42 Display screen acquisition button 100 Nozzle observation apparatus 102 Camera 104 Camera image acquisition part 106 Display screen acquisition Unit 108 image file generation unit 112 built-in storage unit 116 external storage unit 118 display processing unit 120 input / display unit

Claims (5)

A nozzle life determination method for a water jet laser processing machine for laser processing a workpiece by introducing a laser beam into a water jet formed by ejecting water from a nozzle,
An alignment camera that is provided in an optical head that irradiates a laser beam and images a nozzle hole from the upstream side of the laser optical path, images a normal nozzle hole in a state where a water jet is jetted, and stores the image,
Imaging the nozzle hole after use with the alignment camera in a state where water jet is jetted,
Display the stored normal nozzle hole image and the used nozzle hole image side by side,
A nozzle life determination method for a laser beam machine, wherein nozzle life determination is performed based on a difference in image data.   The nozzle life determination method according to claim 1, wherein the image of the nozzle hole in the normal state includes an image of a new nozzle that has not been used for laser processing after replacement.   The image of the nozzle holes after use includes a plurality of nozzle hole images taken at regular processing times after replacement, and the images of the plurality of nozzle holes are displayed in time series. The nozzle life determination method described.   The nozzle life determination method according to claim 1, wherein the captured image of the nozzle hole includes attribute data representing a nozzle identification number, an image capturing date and time, and an identification symbol of the processing machine. In a laser processing machine that processes a workpiece by irradiating the workpiece placed on the table with laser light,
An optical head having a nozzle for jetting water to form a water jet, an optical system for introducing laser light into the nozzle, and an alignment camera for capturing an image of the nozzle hole;
A display unit for displaying an image of a nozzle hole imaged by the alignment camera;
An image file generation unit that embeds attribute data in the image data of the nozzle holes imaged by the alignment camera and generates an image file;
A storage unit for storing an image file by a camera image acquisition button displayed on the screen of the nozzle hole image of the display unit;
Among the image files stored in the storage unit, a plurality of image files including an image file generated from a camera image of a normal nozzle and an image file generated from a camera image of a nozzle after use are arranged in chronological order. A laser processing machine comprising: a display processing unit for displaying on a display unit.

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