JP2004243383A - Laser beam machine, and laser beam machining method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser beam machine where positioning precision to three dimensions is improved, and working for the workpiece with high precision is performed, and a laser beam machining method. <P>SOLUTION: In the laser beam machine where a working laser beam emitted from a laser oscillator is irradiated to the working spot of the workpiece from a laser working head, so that the working spot is subjected to working, a position measuring means of measuring the position of the laser working head moved to the surface of the previously set standard working spot is provided, and the beam emitted from the position measuring means is irradiated coaxially with the processing laser beam. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laser processing apparatus and a laser processing method, and more particularly to a laser processing apparatus for improving positioning accuracy in three dimensions (X, Y, and Z axis directions) and processing a processing object with high accuracy. The present invention relates to a laser processing method.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a laser processing apparatus moves a laser processing head (housing) having an optical system in the XY axis direction and irradiates a processing laser beam from a laser oscillator to a processing point of a processing target. Is going. In addition, recently, there is a workpiece that is not a flat surface (including irregularities), and therefore machining is performed while moving in the height direction (Z-axis direction).
[0003]
Here, in order to realize the processing as described above, as a method of adjusting the position in three dimensions (X, Y, and Z axis directions), the focus of the laser is automatically adjusted on the processing surface of the processing object. There is a teaching method for performing (see, for example, Patent Document 1).
[0004]
In Patent Document 1, prior to three-dimensional laser processing, a processing object is imaged from the X-axis, Y-axis, and Z-axis directions by an imaging unit provided in a laser processing head to create a three-dimensional figure, A rough teaching point and welding posture are input to a figure, and a master JOB is created by an image processing apparatus. Then, a detailed job is detected and a correction JOB for correcting the master JOB is created and teaching is performed.
[0005]
Here, an outline of a laser processing head based on the invention described in Patent Document 1 will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic diagram of a processing head of a conventional laser processing apparatus including an image processing apparatus.
[0006]
The laser processing apparatus of FIG. 1 is configured to have a laser processing head 11, an irradiation nozzle 12, and a CCD camera 13 that is an imaging means, and a processing object 15 is placed on a stage 14. In the invention described in Patent Document 1, a top view, a front view, a left side surface, and a right side surface of the processing object 15 are acquired by the CCD camera 13 installed in the laser processing head 11, and the processing object 15 Create a three-dimensional figure and perform teaching for high-precision processing.
[0007]
In other words, prior to the three-dimensional laser processing, the processing object 15 is imaged by the imaging means provided in the laser processing head to create a three-dimensional figure, and a rough teaching point and a welding posture are input to the figure to obtain a master. After creating a JOB, detailed data is detected and created as a master JOB, so teaching can be performed with one input / output device outside the partition, ensuring safety and reducing the burden on the operator. Working efficiency can be improved.
[0008]
In addition, there is a laser processing apparatus provided with a distance sensor for measuring the distance from the processing object 15 in order to improve the focus accuracy of the processing laser light irradiated to the processing object 15 from the irradiation nozzle 12 ( For example, see Patent Document 2).
[0009]
In Patent Document 2, based on distance data measured by a distance sensor, an approximate curve of distance data or a moving average value is obtained to obtain a correction value for measurement error of distance data, and the correction value is used. By controlling the z stage, laser processing is performed while performing focusing in each processing unit and optimizing the focus position of the processing laser beam.
[0010]
Here, an outline of laser processing having the above-described distance sensor based on the invention described in Patent Document 2 will be described with reference to the drawings. FIG. 2 is a diagram showing an example of a conventional laser processing head unit having a distance sensor.
[0011]
The laser processing head portion of FIG. 2 is configured to have a relay lens 21, a mask 22, a projection lens 23, and a distance sensor 24.
[0012]
In Patent Document 2, the distance sensor 24 is provided in parallel with the projection lens 23 in the X-axis direction, and the distance from the distance sensor 24 to the processing point of the processing object 15 placed on the stage 14 is determined. Measure and move up and down with respect to the Z axis to adjust the focus position. Thereby, advanced laser processing can be realized.
[0013]
[Patent Document 1]
Japanese Patent Laid-Open No. 2000-117466
[Patent Document 2]
Japanese Patent Laid-Open No. 2002-1563
[Problems to be solved by the invention]
However, in the case of the apparatus configuration as shown in Patent Document 1, since the imaging means for imaging the workpiece 15 is attached to the side surface of the laser processing head 11, the width in the X-axis direction in FIG. The moving distance of the head 11 is limited. For example, when processing is performed in a place where the moving space is narrow, if the width of the laser processing head 11 is large, it often occurs that the laser cannot be moved. Therefore, the stage 14 on which the processing object 15 is placed is moved each time. Control is required. In addition, since the CCD camera 13 directly captures the object 15 to be photographed, there is a distance from the actual laser machining point, so that it is necessary to correct the offset between the photographing point and the machining point.
[0016]
Also, in Patent Document 2 in which the focal length is corrected using the distance sensor 24, a place where the distance sensor 24 is installed is separately required. Therefore, when the laser processing head unit is moved, the distance sensor 24 is an obstacle. turn into.
[0017]
The present invention has been made in view of the above-described problems. A laser processing apparatus and a laser for reducing the configuration of a laser processing head, improving positioning accuracy, and processing a workpiece with high accuracy. An object is to provide a processing method.
[0018]
[Means for Solving the Problems]
In order to solve the above problems, the present invention employs means for solving the problems having the following characteristics.
[0019]
The invention described in claim 1 is set in advance in a laser processing apparatus for processing the processing point by irradiating the processing point of the processing target object from the laser processing head with the processing laser light emitted from the laser oscillator. And a position measuring unit that measures the position of the laser processing head that has moved to the reference processing point, and the light emitted from the position measuring unit is irradiated coaxially with the processing laser beam. .
[0020]
According to the first aspect of the present invention, by irradiating the position measuring light coaxially with the processing laser light, the position of the processing point can be more accurately set on the processing surface which is not flat (uneven). It can be measured. Thereby, the focus accuracy of the processing laser beam irradiated from the laser processing head can be improved, and highly accurate laser processing can be realized.
[0021]
The invention described in claim 2 includes an imaging device that captures an image of an area including the reference processing point, and imaging light from the imaging device is irradiated coaxially with the processing laser light. And
[0022]
According to the second aspect of the present invention, since an image including the reference processing point can be taken, an error from the reference processing point can be easily obtained, the positioning accuracy of the laser processing head is improved, and high Accurate laser processing can be realized.
[0023]
The invention described in claim 3 is characterized in that the position measuring means and the imaging device are installed in the laser processing head.
[0024]
According to the third aspect of the present invention, since the position measuring means such as the distance sensor and the imaging device such as the CCD camera are not separately installed in the moving area, the moving range of the laser processing head can be expanded. In addition, it is possible to reduce control in moving the stage on which the workpiece is placed, and to improve the efficiency of the machining operation.
[0025]
In addition, by configuring the measurement light in the position measurement means to irradiate coaxially with the processing laser light, the laser processing head including the position measurement means can be made compact, and the working range can be expanded. Efficiency can be improved.
[0026]
The invention described in claim 4 includes position correction means for correcting the positioning of the laser processing head with respect to the reference processing point based on position data obtained from the position measurement means and the imaging device. Features.
[0027]
According to the fourth aspect of the invention, since correction based on three-dimensional position measurement can be performed, high-precision laser processing is performed even when the processing surface of the processing object is not flat (there is unevenness). be able to.
[0028]
According to a fifth aspect of the present invention, in the laser processing method for processing the processing point by irradiating the processing point of the processing target object from the laser processing head with the processing laser light emitted from the laser oscillator, the laser processing method is set in advance. A position measuring step of measuring the position of the laser processing head moved to the reference processing point, and an imaging step of capturing an image of an area including the reference processing point, and measuring the position in the position measuring step The imaging light and the imaging light in the imaging stage are irradiated coaxially with the processing laser light.
[0029]
According to the fifth aspect of the present invention, by irradiating the position measurement light coaxially with the processing laser light, the position of the processing point can be more accurately determined with respect to the non-planar (uneven) processing surface. It can be measured. Thereby, the focus accuracy of the processing laser beam irradiated from the laser processing head can be improved, and highly accurate laser processing can be realized. In addition, since an image including the reference processing point can be taken, an error from the reference processing point can be easily obtained, and the positioning accuracy of the laser processing head can be improved and high-precision laser processing can be realized. Can do.
[0030]
The invention described in claim 6 includes a position correction step for correcting the positioning of the laser processing head with respect to the reference processing point based on position data obtained from the position measurement step and the imaging step. Features.
[0031]
According to the invention described in claim 6, since correction based on three-dimensional position measurement can be performed, high-precision laser processing is performed even when the processing surface of the processing object is not flat (there is unevenness). be able to.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
The present invention has moved to a preset reference processing point (reference processing point) as a pre-stage for performing processing by irradiating a processing object with a processing laser beam irradiated from a laser processing head in a laser processing apparatus. An imaging device that measures the horizontal direction (XY axis direction) of the stage on which the workpiece is placed with respect to the laser machining head, and a distance sensor that measures the height direction (Z axis direction) of the workpiece. In addition, since the processing point can be directly photographed by arranging the imaging device coaxially with the processing laser beam irradiated to the processing point, for example, highly accurate positioning with respect to a reference processing point such as an alignment mark Can be realized. In addition, by installing a distance sensor on the laser processing head and measuring the distance from the laser processing head to the processing point, the laser processing head can be made compact, even in areas where the moving space is narrow Can be moved. Thereby, the control regarding the movement of the stage can be reduced, and efficient laser processing can be performed. Furthermore, the positioning correction in the height direction of the workpiece can be performed, and the focus accuracy can be improved and high-precision laser processing can be performed.
[0033]
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 3 is a three-dimensional perspective view showing one configuration example of the laser processing head unit in the present invention.
[0034]
The laser processing head unit in FIG. 3 is configured to include a laser processing head 31, an irradiation nozzle 32, a CCD camera 33, and a distance sensor 34. The laser processing head 31 includes a processing laser mirror 35, a processing lens 36, and a distance sensor mirror 37.
[0035]
In FIG. 3, laser light is imaged by the processing lens 36 via the processing laser mirror 35, and processing is performed by irradiating the processing point of the processing object 15 from the irradiation nozzle 32. At this time, the CCD camera 33 and the distance sensor 34 are installed in the laser processing head 31, and the CCD camera 33 irradiates the processing laser beam irradiated to the processing point of the processing object 15 placed on the stage 14. And coaxially, a region including a preset reference processing point is photographed, and the position of the laser processing head 31 after the movement and the reference processing point in the axial direction can be easily obtained. It is possible to correct the positioning error and perform highly accurate laser processing. Here, a YAG laser that transmits visible light is used as the processing laser light. Further, the CCD camera 33 performs imaging by irradiating imaging light for capturing an image of an area including the processing point coaxially with the processing laser light. The image area is adjusted to have a vertical and horizontal width that can be photographed by the CCD camera installed, and the reference processing point is positioned at the center of the area.
[0036]
Further, the distance sensor 34 does not measure the distance of the processing point by directly irradiating the processing object 15 in FIG. 3 with the measuring light, but the distance sensor mirror 37 is provided from the inside of the laser processing head 31. For example, even when the surface of the processing object 15 is not flat, the position of the processing point where laser processing is performed can be measured, so that the focal length can be corrected with high accuracy. And laser processing accuracy can be improved.
[0037]
In FIG. 3, for example, the processing laser mirror 35 is configured to reflect laser light from the X-axis direction and transmit light from the Z-axis direction. Further, the distance sensor 34 irradiates the distance sensor mirror 37 with the position measurement light from the distance sensor 34, and the light is reflected by the distance sensor mirror 37 and irradiated onto the workpiece 15. The Thereafter, the time until the light reflected by the workpiece 15 is reflected by the distance sensor mirror 37 and detected by the distance sensor 34 is measured. That is, the time from when the laser is emitted from the distance sensor 34 to when it is reflected by the workpiece 15 and returned to the distance sensor 34 can be measured, and the distance can be obtained from the wavelength and time of the emitted light.
[0038]
Further, the distance sensor mirror 37 is configured to be able to pass or reflect the light from the Z-axis direction depending on the wavelength of the light, and the light from the distance sensor has a wavelength different from that of the processing laser light. To do.
[0039]
Further, the processing laser mirror 35, the imaging lens 36, and the distance sensor mirror 37 are transparent, and there is no problem in measuring the processing point from the CCD camera.
[0040]
As described above, the position of the laser processing head can be measured with high accuracy by measuring the processing position of the processing target 15 with the CCD camera 33 and the distance sensor 34 in three axes (three-dimensional) of the XYZ axes. Furthermore, various processing can be realized according to the processing purpose.
[0041]
Further, since the CCD camera 33 and the distance sensor 34 are installed in the laser processing head 31 and measurement is performed from the inside of the head, it is not necessary to install a large apparatus, and the total volume of the head portion can be reduced, so that laser processing is performed. Since the moving range of the head portion can be expanded and the stage 14 need not be moved accordingly, efficient laser processing can be realized.
[0042]
The configuration of the laser processing head unit shown in FIG. 3 is not limited to the above. For example, the positions of the CCD camera 33 and the distance sensor 34 may be exchanged. You may install in the inner surface of a process head part.
[0043]
Next, a laser processing apparatus having the above-described laser processing head unit will be described with reference to the drawings.
[0044]
FIG. 4 is a diagram showing a configuration example of the laser processing apparatus according to the present invention.
[0045]
4 includes a laser oscillator 41, a laser processing head 42, an irradiation nozzle 43, a CCD camera 44, a distance sensor 45, a position correction unit 46, a drive unit 47, a stage 48, And a control unit 49. Further, the laser processing head 42 is configured to include a processing laser mirror 50, a processing lens 51, and a distance sensor mirror 52. Here, the control unit 49 emits laser light from the laser oscillator 41, moves the laser processing head 42 to the reference processing point in the X, Y, and Z directions by the driving unit 47, and sets the X of the stage 48. The movement timing in the -Y-Z axis direction is controlled. Further, the control in the control unit 49 is performed by the position measurement data taken in the XY axis direction taken from the CCD camera 44 and the Z measured by the distance sensor 45 in moving to a preset reference processing point. The position (distance) measurement data in the axial direction is input to the position correction unit 46, and the position correction unit 46 determines the error in the XY axis direction from the reference machining point based on the input measurement data, and the Z-axis direction. Correction data corresponding to the focus error is calculated and output to the control unit 49. Based on the correction data of the position correction unit 46, the control unit 49 outputs a movement control signal related to the correction of the drive unit 47 and the stage 48 to the drive unit 47 and the stage 48 to correct the movement position.
[0046]
In addition, about the movement, either the drive part 47 or the stage 48 may be sufficient, and both may be sufficient. Further, the laser processing head 42 and the stage 48 can move in the X, Y, and Z axis directions, and the control unit 49 controls the drive unit 47 and the stage 48 so as to minimize the moving distance. Is output. Thereby, the movement between processing points can be performed rapidly and the working efficiency of laser processing can be improved.
[0047]
In addition, about the correction value calculation method regarding the difference | error with a reference | standard process point, it can obtain | require by using the method of patent document 1 and 2 mentioned above. For example, the correction value can be calculated by obtaining an approximate curve of distance data or obtaining a moving average value. The correction value is calculated from an error between the measured value and the reference processing point by measuring the position of the laser processing head that has moved with respect to a preset reference processing point. Further, by correcting the positioning error so that the focal point of the laser beam imaged by the processing lens 51 is positioned not only in the X-Y axis direction but also at the processing point of the processing object 53, high-precision laser processing is performed. Can be realized.
[0048]
Next, the laser processing procedure in the present invention will be described using a flowchart. The laser processing procedure will be described based on the configuration of the laser processing apparatus in FIG. 4, but the configuration of the laser processing apparatus in the present invention is not limited to this.
[0049]
FIG. 5 is a flowchart of an example showing the flow of the laser processing procedure in the present invention. Here, it is assumed that the workpiece 53 is already placed on the stage 48.
[0050]
In FIG. 5, first, the control unit 49 outputs a control signal to the stage 48 in order to move to a preset machining position, and moves the stage 48 to a position where the machining point can be machined (S01). ). Next, a control signal is output to the drive unit 47 in order to move it to a preset reference machining point of the workpiece 53, and the drive unit 47 moves the machining head 42 to the machining position in the XYZ directions. Including positioning is performed (S02). In the present invention, the order of S01 and S02 may be reversed, and S01 and S02 may be performed simultaneously.
[0051]
Next, the position of the moved laser processing head in the XY axis direction is measured using the CCD camera 44 (S03). In the measurement, an image of a region including a processing point is captured by imaging light from the CCD camera 44, and a point on the XY axis of a reference processing point set in advance from the image and an X- after moving. A position coordinate is obtained based on the XY axis coordinate associated with the point on the Y axis on the stage 48, and is output to the position correction unit 46.
[0052]
Further, the position of the machining point in the Z-axis direction is measured using the distance sensor 45, and the position for adjusting the focal point of the machining laser light emitted from the imaging lens to be positioned at the machining point is measured. (S04). Regarding the distance measurement by the distance sensor 45, as described above, the processing laser beam is irradiated from the distance sensor 45 to the distance sensor mirror 50, and the light is irradiated to the processing object 53 via the distance sensor mirror 50. The time until the light reflected from the workpiece 52 is reflected by the distance sensor mirror 50 and detected by the distance sensor 45 is measured, and the distance is calculated from the wavelength and time of the laser light emitted from the distance sensor. Ask. In this embodiment, the distance between the distance sensor 45 and the distance sensor mirror 50 is constant, and the distance from the distance sensor mirror 50 to the processing lens 51 is constant, so that the processing from the processing lens 51 is performed. The distance to the point can be easily calculated. The calculated distance (position) data is output to the position correction unit 46.
[0053]
Next, the position correction unit 46 determines from the reference processing point and the processing lens 51 based on the position data in the XY axis direction obtained by the CCD camera 44 and the position data in the Z axis direction obtained by the distance sensor 45. An error from the focal length is calculated, and the correction data is obtained and output to the control unit 49. Based on the correction data input from the position correction unit 46, the control unit 49 moves the drive unit 47 and the stage 48 for positioning correction (S05).
[0054]
After completion of the correction in S05, the control unit 41 outputs a control signal to oscillate the machining laser to the laser oscillator 41. The laser oscillator 41 emits a laser beam based on the inputted laser oscillation instruction and performs laser machining. (S06).
[0055]
After S06 ends, the control unit 49 determines whether the processing of all the processing points on the processing object 53 has ended (S07). If the processing has ended (YES in S07), the process ends. If there is a processing point that has not been processed (NO in S07), the process returns to S01 to move to the next processing point, and the processing from S02 to S06 is performed.
[0056]
With the laser processing procedure described above, the positioning accuracy of the laser processing head in three dimensions can be improved, and laser processing can be performed with high accuracy.
[0057]
As described above, according to the present invention, a processing point is compared with a processing surface that is not flat by comparing position measurement having a conventional offset distance by irradiating position measuring light coaxially with the processing laser light. Can be measured with higher accuracy. Thereby, the positioning accuracy of the laser processing head can be improved and high-precision laser processing can be realized.
[0058]
In addition, imaging light from a CCD camera (imaging device) that captures an image of an area including the processing point of the processing object is irradiated coaxially with the processing laser light, thereby imaging the processing point as it is. Therefore, comparison with the reference point can be easily performed, positioning accuracy of the laser processing head can be improved, and high-precision laser processing can be realized.
[0059]
In addition, by installing the distance sensor and the CCD camera on the laser processing head, it is not necessary to provide a separate installation area for the distance sensor and the CCD camera, and the moving area of the laser processing header can be expanded, so Control of movement of the stage placed can be reduced, and the efficiency of the machining operation can be improved. Moreover, since it is installed so as to emit measurement light coaxially with the processing laser light, the laser processing head can be made compact, and the moving range can be expanded to improve the efficiency of the processing operation.
[0060]
Furthermore, by providing a position correction unit for obtaining correction data for a reference processing point set in advance and a focal length from the processing lens based on position data obtained from the distance sensor and the imaging device, the three-axis direction ( Correction based on (three-dimensional) position measurement can be performed. Thereby, even when the processing surface of the processing object is not flat (having irregularities), high-precision laser processing can be performed.
[0061]
It should be noted that the present invention is not limited to the specifically disclosed embodiments, and various modifications and embodiments can be considered without departing from the scope of the claimed invention.
[0062]
【The invention's effect】
As described above, according to the present invention, the positioning accuracy of the three-dimensional laser processing head can be improved, and laser processing can be performed with high accuracy.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic diagram of a processing head of a conventional laser processing apparatus including an image processing apparatus.
FIG. 2 is a diagram showing an example of a conventional laser processing head unit having a distance sensor.
FIG. 3 is a three-dimensional perspective view showing a configuration example of a laser processing head portion in the present invention.
FIG. 4 is a diagram illustrating a configuration example of a laser processing apparatus according to the present invention.
FIG. 5 is a flowchart of an example showing a flow of a laser processing procedure in the present invention.
[Explanation of symbols]
11, 31 Laser processing head 12, 32, 43 Irradiation nozzles 13, 33, 44 CCD camera 14, 48 Stage 15, 53 Processing object 21 Relay lens 22 Mask 23 Projection lenses 24, 34, 45 Distance sensors 35, 50 Laser light Mirrors 36, 51 Processing lenses 37, 52 Distance sensor mirror 40 Laser processing device 41 Laser oscillator 46 Position correction unit 47 Drive unit 49 Control unit

Claims (6)

In the laser processing apparatus for processing the processing point by irradiating the processing point of the processing object from the laser processing head with the processing laser light emitted from the laser oscillator,
Having a position measuring means for measuring the position of the laser processing head moved to a preset reference processing point;
The laser processing apparatus, wherein the light emitted from the position measuring means is irradiated coaxially with the processing laser light. An imaging device that captures an image of an area including the reference processing point;
The laser processing apparatus according to claim 1, wherein the imaging light from the imaging apparatus is irradiated coaxially with the processing laser light. The laser processing apparatus according to claim 1, wherein the position measuring unit and the imaging device are installed in the laser processing head. 4. The apparatus according to claim 1, further comprising a position correction unit configured to perform positioning correction of the laser processing head with respect to the reference processing point based on position data obtained from the position measurement unit and the imaging device. The laser processing apparatus of Claim 1. In the laser processing method for processing the processing point by irradiating the processing point of the processing object from the laser processing head with the processing laser light emitted from the laser oscillator,
A position measurement step for measuring the position of the laser processing head moved to a preset reference processing point, and an imaging step for capturing an image of an area including the reference processing point;
The laser processing method, wherein the light for measuring the position in the position measurement stage and the imaging light in the imaging stage are irradiated coaxially with the processing laser light. 6. The laser according to claim 5, further comprising a position correction step of performing positioning correction of the laser processing head with respect to the reference processing point based on position data obtained from the position measurement step and the imaging step. Processing method.

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