JPH03146285A - Laser processing controller - Google Patents

Abstract

PURPOSE:To correct an operation with a change in processing conditions and to execute exact laser processing by detecting the light from a laser processing point, judging a processing condition, correcting the processing conditions in accordance with the result of the judgment and controlling the conditions to optimum processing conditions. CONSTITUTION:A laser controller 5 starts piercing of a work 4 by irradiating the work 4 with the laser beam from a laser oscillator 1 from a processing head 2 according to a set program. CCD cameras 7, 8 photograph the light from the laser processing point, apply the same to an image processor 9 and sends the processed data to a processing diagnosis device 10. The data on the cutting conditions processed by the image processor and the data on the laser beam at the time of good cutting area diagnosed and the correction data of the laser controller 5 and a numerical controller 6 is formed and two controllers 5, 6 are subjected to the correction control in such a manner that good cutting is executed and, therefore, the generation of a cutting defect is obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention (Industrial Application Field) The present invention relates to a laser processing control device that controls laser processing such as cutting and welding of a workpiece using laser light.

(Prior Art) A conventional laser processing device is composed of a control device that controls a laser beam, a numerical control device that controls movement of a workpiece, etc., and is controlled by the control device according to a preset control program. Laser shutter opening/closing control,
The laser output is controlled, the processing gas is supplied and stopped, and the numerical control device moves the table on which the workpiece is fixed at a predetermined speed in a predetermined direction, so that the workpiece is laser-processed. It has become so.

(Problem to be Solved by the Invention) However, since each control is performed according to a preset control program, unexpected changes in processing conditions, such as changes in the directionality of laser processing, and If there is an effect of rust that occurs on the surface of the workpiece, a difference in the gloss of the surface of the workpiece, etc., processing defects will occur, resulting in the workpiece being defective.

In general, laser cutting requires piercing to create a hole in the workpiece at the start of cutting, but the thicker the workpiece, the higher the reflectance of the workpiece's surface. It is true that it takes time, and it is difficult to accurately predict the required time.

Therefore, conventionally, when programming the time required to drill a hole into a numerical control device, it is common to set it to a considerably long time to ensure that the hole is drilled.
For this reason, in processes that require a large number of holes to be drilled, for example, when manufacturing many small parts from a workpiece, the time required to drill the holes is relatively long, which has the disadvantage of requiring a lot of processing time overall. Ta.

Therefore, an object of the present invention is to detect the light generated during laser processing, determine the laser processing state from this light, and correct the preset processing conditions based on the result of this judgment. Moreover, it is an object of the present invention to provide a laser processing control device that can realize accurate laser processing.

[Structure of the Invention (Means for Solving the Problems) The present invention is an apparatus that starts processing a workpiece with a laser beam based on preset processing conditions, and the present invention is directed to starting processing of a workpiece with a laser beam based on preset processing conditions. A detection means for detecting the light of The present invention is characterized by comprising a control means for controlling laser processing.

(Function) According to the above means, the detection means detects the light from the laser processing point that occurs during laser processing to judge the laser processing situation, and based on the judgment result, the preset laser processing conditions are corrected. Because of this, high-quality laser processing can be performed at all times during laser processing.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings. A laser beam from a laser oscillator 1 is irradiated from a laser processing head 2 to a workpiece 4 (hereinafter referred to as a workpiece) placed on a processing table 3. The laser oscillator 1 is configured to control the opening and closing of a laser shutter, control the laser output, and supply and stop processing gas according to a control program set in advance by a laser control device 5 that controls laser light. Further, the processing table 3 to which the workpiece 4 is fixed is moved in a predetermined direction at a predetermined speed according to a control program set in advance by a numerical control device 6. Processing table 3
There is a CCD camera 7 as a detection means on the front and right side of the
．． 8 is provided, and the image signal obtained thereby is provided to an image processing device 9. The signal processed by this image processing device 9 is given to a processing diagnosis device 10, where it is compared with data of each processing situation to identify the laser processing situation.

Next, the operation of the above configuration will be explained with reference to the flowchart shown in FIG. Workpiece 4 on processing table 3
is set and a machining start switch (not shown) is operated, the numerical $q control device 6 moves the table 3 according to a preset program, and the machining head 2 faces the cutting start position of the workpiece 4. Make it. Then, the laser control device 5 starts piercing the workpiece 4 by irradiating the laser beam emitted by the laser oscillator 1 at that position from the Radar 2 to the workpiece 4 according to a preset program [Step (a)] During piercing, the irradiated laser beam is reflected at the laser processing point and heads upwards on the workpiece 4 as shown in Figure 2, but when piercing is completed and the cutting is done normally. When the laser beam is present, the laser beam passes through the workpiece 4 and heads downward as shown in FIG. The CCD camera 7.8 photographs the light from the laser processing point and supplies it to the image processing device 9, which processes the photographed image and sends the processed data to the processing diagnosis device 10 [Step (b)].

When the light from the laser processing point is directed upward from the workpiece 4, it is determined in step (c) that piercing has not been completed (No), and the light from the laser processing point penetrates the workpiece 4. When it starts to move downward, step (
In step C), it is determined that the piercing has been completed (YES), and the process moves to step (d), where "data on laser light during good cutting" is imported from the database into the processing diagnosis device 10.

This database includes image data of the laser beam generated when laser processing is good, such as the spread situation of the laser cutting light, the scattering situation, the following scattering situation of the laser cutting light in the laser cutting direction, the following situation, etc. Registered.

Further, in step (e), the numerical control device 6 moves the processing table 3, and the laser control device 5 controls the laser beam to a state suitable for cutting, thereby performing "cutting". During cutting, cutting status data photographed by the COD camera 7°8 and processed by the image processing device 9 and "data of laser light during good cutting" are constantly diagnosed by the processing diagnostic device 10, and the cutting status is checked. Whether or not the cut is good is determined in step (f) by comparison with the normal cutting data taken in step (d). If it is determined (YES) in this step (f), the process moves to step (g), where it is judged whether or not cutting is in progress, and if cutting is in progress (YES), the process moves to step (e), where cutting is performed. If the process continues and the cutting is completed (No), the process moves to the next process (step h).

For example, if the cutting is defective and it is determined (NO) in step (f), the process moves to step (i) and the "Create correction data for the laser control device" system is executed based on the pre-registered correction control method. , proceed to step (j), that is, "correct the operation of the laser control device", and output, for example, laser output correction control, laser frequency correction control, laser pulse force correction control commands, etc. based on the above correction data to control the laser. Various control conditions of the device 5 are corrected and controlled, and then the process moves to step (k) to "create correction data for the numerical control device" based on the pre-registered correction control method, and step (fI) Then, based on the above correction data, "correct the movement of the processing table by the numerical control device" to correct conditions such as the moving speed of the numerical control device 5, and as described above, the laser control device 6 starts laser oscillation. After the apparatus 1 is corrected and the movement of the processing table 3 is corrected and controlled by the numerical control device 6, the process moves to step (e) to further continue cutting.

In the above-mentioned embodiment, the light from the laser processing point is constantly monitored by the CCD camera 7.8, and the cutting process can be started immediately after the piercing process is completed. There is no longer a need to set a long piercing time, and even for items with a large number of piercings, it is possible to move on to the cutting process in the minimum amount of time required, compared to the conventional case where the piercing time was set longer. Therefore, even if there are a large number of piercings, the time required for processing can be minimized.

Further, if it is determined that the cutting state is not normal during cutting, the laser control device 5 and the numerical control device 6 are corrected and controlled so that the cutting is performed normally, so there is no risk of cutting defects.

In addition, in the above embodiment, since the CCD camera 7°8 is used to obtain images of the light from the laser processing point from two directions, the images can be judged three-dimensionally, making the judgment results more accurate. However, it is of course possible to detect the image from only one direction.

In addition, although the above description is based on an example in which cutting is performed with a laser beam, the present invention can be similarly applied to laser welding, laser heat treatment, or the like.

In addition, instead of the image processing device 9, a spectral analyzer is used as a detection means for detecting light from a laser processing point to detect the color of the light, and the processing status is identified and judged based on the color data. You can do it like this.

Also, instead of the image processing device 9, a temperature distribution analyzer is used as a detection means for detecting light from the laser processing point to detect the temperature distribution of the light, and the processing status can be identified and processed based on the temperature distribution data. You may also choose to make a judgment.

[Effects of the Invention] As is clear from the above description, the present invention starts machining of a workpiece with a laser beam based on preset machining conditions, and the present invention reduces the amount of damage from the laser machining point that occurs during laser machining. A detection means for detecting light, and the laser processing situation at the time is judged based on the light detected by this detection means, and the processing conditions are corrected based on the judgment result, so that the optimum processing conditions are always maintained during laser processing. The present invention is characterized in that it is equipped with a control means for controlling laser processing, and is capable of correcting the operation in response to changes in processing conditions appropriately.
Overall, accurate laser processing can be performed in a short time.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic configuration diagram, FIGS. 2 and 3 are diagrams showing the state of light from a laser processing point, and FIG. 4 is a flow chart. . In the drawing, 1 is a laser oscillator, 3 is a processing table, 5 is a laser control device, 6 is a numerical control device, 7 and 8 are CCD cameras (detection means), 9 is an image processing device, and 10 is a processing diagnosis device.

Claims (1)

[Claims] 1. In a device that starts processing a workpiece with a laser beam based on preset processing conditions, a detection means for detecting light from a laser processing point generated during laser processing, and a detection means for detecting light from a laser processing point generated during laser processing, and The present invention is characterized by comprising a control means for determining the current state of laser processing based on the light, correcting the processing conditions based on the judgment result, and controlling the laser processing using the optimum processing conditions at all times during laser processing. Laser processing control device.