JPH11784A - Laser beam machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute proper heat input control and to improve the quality of machining by machining an object to be machined while always scanning a laser beam in the direction orthogonal to the machining line. SOLUTION: The operation is executed with a scanner controller 30 based on the transfer command value inputted from the table controller 18 controlling the transfer of a machining table 16, scanner motors 34, 38 of a scanner driving part 28 are driven and controlled to operate scanning mirrors 32, 36, and the laser beam LB outputted from a beam generating part 12 is always scanned in the direction orthogonal to the machining line of the object to be machined. By this way, the proper heat input control is executed to the machining line of the object to be machined and then the quality of machining is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus, and more particularly, to a laser processing apparatus that performs processing while scanning a workpiece with a laser beam.

[0002]

2. Description of the Related Art Conventionally, a laser processing apparatus using a laser beam has been used when performing thermal processing such as cutting, drilling, or quenching a workpiece along a processing line.

A laser beam used in this type of laser processing apparatus is coherent light having good directivity and output using a laser oscillator. Therefore, when condensed by a lens or the like, the laser beam can be narrowed down to about the wavelength of the laser light. From that
A very small heat source having a high energy density can be obtained.

For this reason, when the surface of the workpiece is irradiated with the minute heat source, the temperature of a local portion of the irradiated material is instantaneously increased, and the material is heated and evaporated to form a hole or cut.
Thermal processing such as welding and quenching can be performed. These laser thermal processings are performed by adjusting the processing energy density, the irradiation time, and the like according to the material and the processing content.

For example, FIG. 8 is a block diagram showing a schematic configuration of a conventional laser processing apparatus 70. In the figure, the laser processing apparatus 70 includes a beam generating section 72 for generating a laser beam LB, A beam scanning unit 74 that performs laser thermal processing while scanning the beam LB to irradiate the processing position of the workpiece 96.

[0006] As shown in FIG.
Includes a laser oscillator 76 and an oscillator control unit 78. The laser oscillator 76 is controlled in accordance with an output command value such as a beam output and a frequency set by the oscillator control unit 78, and a desired laser beam LB is output. The output laser beam LB is refracted by the bend mirror 80 and is input to the beam scanning unit 74.

[0007] The beam scanning section 74 to which the laser beam LB has been input includes a condensing section 82, a scanner driving section 84, and a scanner control section 86. The scanner driving section 84
Further, a scanning mirror (X-axis) 88, a scanner motor (X-axis) 90, and a scanning mirror (Y-axis) 92
And a scanner motor (Y-axis) 94. Therefore, the laser beam LB input to the beam scanning unit 74
Is condensed by a condensing unit 82 such as a lens, is reflected by a scanning mirror 88 and a scanning mirror 92 of a scanner driving unit 84, and is irradiated onto a workpiece 96.

At this time, scanning mirrors 88 and 9
2 operates by controlling the driving of a scanner motor (X-axis) 90 and a scanner motor (Y-axis) 94 in the scanner driving section 84 in accordance with the amplitude and frequency set by the scanner control device 86. The laser beam LB was scanned on the workpiece 96 in the X-axis and Y-axis directions in accordance with the operation of 92.

For example, a scanner motor (X-axis) 90 using a sine waveform or a triangular waveform by the scanner control unit 86.
When the scanner and the scanner motor (Y-axis) 94 are simultaneously controlled, the laser beam LB can be scanned in a circular or square shape.

[0010]

As described above, the conventional laser processing apparatus is constituted, but has the following problems.

That is, since the conventional beam scanning section 74 and beam generating section 72 are independently controlled by the scanner control section 86 and the oscillator control section 78, respectively, for example, the laser beam LB Is processed by drawing a free curve while scanning in a circle using a beam scanning unit that scans in two axes (for example, the X axis and the Y axis). Undercuts due to excessive heat input and processing defects due to uneven heat input occur, and welding with a large scanning amplitude has a disadvantage that a molten pool is pulled by a laser beam and a biased undercut occurs.

Therefore, a method of performing beam scanning in one axial direction perpendicular to the processing line to equalize the heat input has been performed. However, in the conventional beam scanning unit 74, the beam scanning direction is independently set. For example, when the workpiece 96 is placed on a processing table (not shown) and processed while being moved, the scanning direction cannot be changed in synchronization with the moving direction.

That is, it is possible to perform scanning in the same direction as the scanning axis system of the beam scanning unit 74, for example, in the direction orthogonal to the processing line in only the X-axis direction or the Y-axis direction. There is an inconvenience that it cannot correspond to a processing line composed of a free curve in the vector direction obtained by combining the direction and the Y-axis direction.

The laser beam LB output from the laser oscillator 76 has an elliptical beam shape or beam spot shape depending on the type of the laser oscillator 76 and its characteristics. There was a disadvantage that the groove width and the weld bead width could not be kept constant.

The present invention has been made in view of the inconvenience of the prior art, and always performs beam scanning in a direction orthogonal to the processing line even if the processing line of the workpiece is a free curve. It is a first object of the present invention to provide a laser processing apparatus capable of uniformly controlling heat input to a processing line of a workpiece and improving processing quality.

In addition, laser processing which automatically corrects a beam shape of a laser beam to an appropriate beam shape, enables appropriate heat input control to a processing line of a workpiece, and improves processing quality. A second object is to obtain a device.

Further, the beam spot shape of the laser beam is automatically corrected to an appropriate beam spot shape, so that appropriate heat input control to the processing line of the workpiece can be performed, and the processing quality can be improved. A third object is to obtain a laser processing device.

[0018]

In order to achieve the above object, in a laser processing apparatus according to the present invention, a beam generating means for generating a laser beam, and a laser beam generated from the beam generating means are focused. And a beam scanning means for irradiating the workpiece while scanning the same, at least in a plane substantially perpendicular to the laser beam emitted from the beam scanning means and placed on the workpiece A table movable in two axial directions, and a table control means for controlling the movement of the table along a processing line based on a movement command value relating to a movement amount and a movement speed, wherein the beam scanning means comprises a focused laser. A scanner driving unit that scans the beam with at least two orthogonal scanning axes; and the processing target based on a movement command value of the table control unit. It is characterized in that a scanner control unit for controlling the scanner drive unit so that the laser beam is always scanned in a direction perpendicular to the processing line of.

According to the present invention, the table on which the workpiece is placed and moved is controlled by the table control means along the processing line based on the movement command value relating to the movement amount and the movement speed, and the beam scanning means is controlled by the table control means. The scanner drive unit is controlled such that the scanner control unit always scans the focused laser beam in the direction orthogonal to the processing line of the workpiece based on the movement command value of the table control unit. For example, the scanner control unit controls the movement amount and the movement speed of the table control means for relatively moving the beam scanning unit and the workpiece as a movement command value, and automatically sets X based on the movement command value. By controlling the beam scanning amount in the axial direction and the Y-axis direction and the waveform phase of each axis, beam scanning in one axis direction that is always orthogonal to the processing line of the workpiece is obtained. For this reason, even with a processing line in which the processing direction changes like a free curve, it is possible to always perform uniform heat input control, and processing defects such as undercut and uneven heat input do not occur. Laser processing with good processing quality can be performed.

The laser processing apparatus according to the next invention further comprises a beam shape sensor for detecting a beam shape of the laser beam generated by the beam generating means, wherein the beam generating means oscillates light. A laser oscillator that outputs a laser beam, and an oscillator control unit that controls a beam output and an oscillation frequency of the laser oscillator based on a predetermined output command value, wherein the scanner control unit is output from the beam shape sensor. Is compared with the beam shape data serving as a reference based on the output command value of the oscillator control unit, and the laser beam is scanned with a predetermined swing width so as to quasi-correctly correct the difference beam shape. The scanner drive unit is controlled by deriving a command value.

According to the present invention, the beam shape of the laser beam generated from the beam generating means is detected by the beam shape sensor, and the scanner control means stores the beam shape data detected by the beam shape sensor and the beam generating means. The scanner driving unit compares the beam output of the laser oscillator and the reference beam shape data based on the output command value of the oscillator control unit that controls the oscillation frequency, and pseudo-corrects the difference beam shape. The laser beam is scanned with a predetermined swing width under control. For this reason, even if the beam shape generated by the beam generating means is different from the reference beam shape, the laser beam is scanned at a predetermined swing width to perform a pseudo correction, whereby
Appropriate heat input control to the processing line of the workpiece can be performed, and the processing quality can be improved.

In the laser processing apparatus according to the next invention, the reference beam shape data is data indicating a circular beam shape having a predetermined diameter.

According to the present invention, since the laser beam is corrected based on the circular beam shape data, appropriate laser processing can be performed without changing the processing width regardless of the scanning direction.

In the laser processing apparatus according to the next invention, the apparatus further comprises a beam shape sensor for detecting a beam shape of the laser beam generated by the beam generating means, and the scanner control means comprises: Based on the output beam shape data, the beam spot shape data obtained by scanning the laser beam having this beam shape along a predetermined beam locus is compared with the reference beam spot shape data, and a difference beam spot is obtained. It is characterized in that a beam locus of a laser beam is corrected and controlled by the scanner driving unit so as to correct the shape.

According to the present invention, the beam shape of the laser beam generated from the beam generating means is detected by the beam shape sensor, and the scanner control means scans the laser beam with a predetermined beam locus based on the beam shape data. The beam spot shape data obtained by the comparison is compared with the reference beam spot shape data, and the scanner driver is controlled so as to correct the difference beam spot shape, and the beam locus of the laser beam is corrected and controlled. .
Therefore, even if the shape of the beam spot obtained by scanning the laser beam with a predetermined beam trajectory is deformed due to the influence of the beam shape or the like, the beam spot can be corrected and an appropriate beam spot shape can be obtained. Appropriate heat input control to the processing line of the workpiece becomes possible, and the processing quality can be improved.

In the laser processing apparatus according to the next invention, the reference beam spot shape data is data indicating a circular beam spot shape having a predetermined diameter.

According to the present invention, since the beam trajectory of the laser beam is corrected based on the data of the circular beam spot shape, proper laser processing can be performed without changing the processing width regardless of the scanning direction. .

In the laser processing apparatus according to the next invention, the beam generating means is provided with a laser oscillator for generating a carbon dioxide laser.

According to the present invention, since a carbon dioxide laser having a large output suitable for laser thermal processing is used for a laser oscillator, it is possible to meet the demand for uniform heat input control to a workpiece.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the laser processing apparatus according to the present invention will be described below in detail with reference to the drawings.

(Embodiment 1) FIG. 1 shows Embodiment 1
FIG. 2 is a block diagram of the laser processing apparatus 10 according to FIG.
FIG. 3 is a conceptual diagram illustrating a relationship between a processing speed and beam scanning, and FIG. 3 is a perspective view illustrating a processing line on a workpiece and a scanning direction of a laser beam. The laser processing apparatus 10 according to the first embodiment is provided with carbon dioxide (CO ₂ ).
The present invention is implemented as a laser processing apparatus that performs laser thermal processing such as welding using a gas laser.

In FIG. 1, the laser processing apparatus 10 includes a beam generating unit 12 as a beam generating means for generating a laser beam LB, and scans the laser beam LB to irradiate a processing line of a workpiece 40 with the laser beam LB. A beam scanning unit 14 is provided as a beam scanning unit that performs thermal processing and performs welding or the like.

Here, the beam generating unit 12 is provided with a carbon dioxide (CO)
₂ ) a laser oscillator 20 for generating a coherent laser beam by oscillating light emitted from each atom when a gas is used as a laser substance and a high voltage is applied thereto to excite the laser substance and shift to a base order; An oscillator control unit 78 that controls a beam output, a frequency, and the like to the laser oscillator 20 based on the output command value and outputs a laser beam LB.

The beam scanning unit 14 includes a light condensing unit 26 composed of an optical system for condensing the laser beam LB output from the beam generating unit 12 and refracted by the bend mirror 24.
The scanner drive unit 28 scans the focused laser beam LB in a predetermined direction, and the scanner control unit 30 controls the drive state of the scanner drive unit 28. Here, a galvanometer is used for the beam scanning unit 14.

Further, the scanner driving unit 28 is
6, a scanning mirror 32 for scanning the laser beam LB focused in the X-axis direction, a scanner motor 34 for driving the same, a scanning mirror 36 for scanning the laser beam LB in the Y-axis direction, and a scanner for driving the same. And a motor 38.

In the first embodiment, the workpiece 40, which is the object to be processed, is movably mounted on the processing table 16. This processing table 16 has an X-axis
It has two or more axes of movement such as axes,
Can be freely moved in a two-dimensional plane in a state where it is gripped and fixed.

An NC (Numerical Control Unit) is usually used for the table controller 18 as a table controller for controlling the movement of the processing table 16. This NC
, A machining program is registered in advance, and a movement command is set according to the machining program, and a predetermined machining process control is performed using the value. In the machining program, machining speed, machining shape data, and the like are also programmed, and axis calculation control is performed by the NC according to the program setting data, and various machining operations are performed.

In the first embodiment, the table controller 18
By inputting the command value output from the scanner control unit 30 into the scanner control unit 30, the traveling direction of the processing line is determined, and control is performed so that the beam scanning is always perpendicular to the processing progress direction.

Next, the laser beam L in the scanner control unit 30 which is a characteristic component according to the first embodiment.
Control of the scanning amount B will be described with reference to FIG. The beam scanning unit 14 including the scanner control unit 30 includes:
Galvanometers are used.

First, as shown in FIG. 2, the moving speed (working speed) of the working table 16 is the X-axis moving speed.
2. The combined speed F is obtained when the Y-axis moving speed is Y1, and the swing width A of the beam scanning for scanning in the direction perpendicular to the moving direction of the processing table 16 is X1 of the X-axis scanning amount and Y-axis scanning amount. Is expressed as a combined scanning amount with Y2.

Here, when the moving axis direction of the processing table 16 and the scanning axis direction of the beam scanning are the same axis direction,
Scanning mirror (X
The scanning amount of each of the (axis) 32 and the scanning mirror (Y-axis) 36 has a relationship represented by the following equations (1) and (2).

[0042]

(Equation 1)

Accordingly, the scanning amount (amplitude amount) of the scanning axis of each scanning mirror is equivalent to the above-mentioned relational expression.
, It is possible to realize beam scanning that is always orthogonal to the processing line.

Here, the beam scanning command from the scanner control unit 30 to the scanner driving unit 28 is based on the X-axis and the Y-axis.
The command value of the same frequency is used for the axis. When the moving direction of the processing table 16 is the first quadrant (the X axis and the Y axis move in the plus direction) and the third quadrant (the X axis and the Y axis move in the minus direction), the scanning mirror (X
The amplitude waveforms of the scanning axis (axis) 32 and the scanning mirror (Y axis) 36 have the same phase, and the moving direction of the processing table 16 is the second quadrant (the X axis moves in the negative direction, the Y axis moves in the positive direction) and the fourth quadrant ( When the X axis moves in the plus direction and the Y axis moves in the minus direction), the phase of the amplitude waveform of the scanning mirror (X axis) 32 and the scanning mirror (Y axis) 38 is set to 1
By shifting by 80 °, beam scanning can always be performed in a direction orthogonal to the processing line.

Next, the operation will be described. In FIG. 1, a laser beam LB is output from a laser oscillator 20 in accordance with an output command value such as a beam output and a frequency set by an oscillator control device 22 of a beam generation unit 12. This laser beam LB is applied to the workpiece 40 by the bend mirror 24.
, Is condensed by the condensing unit 26 of the beam scanning unit 14, is narrowed down, and is irradiated on a processing line on the workpiece 40 while being scanned in the X-axis and Y-axis directions by the scanner driving unit 28. You.

Here, in the beam scanning unit 14, the scanner control unit 30 includes the movement amount and speed of the processing table 16 input as the movement command value from the table control unit 18.
By automatically controlling the beam scanning amount in the X-axis direction and the Y-axis direction and the waveform phase of each axis based on the above equations (1) and (2) according to the amplitude and frequency of the laser beam set in The scanner motor (X-axis) 34 and the scanner motor (Y-axis) 38 in the scanner drive unit 28 are driven and controlled so that the laser beam is always scanned in a direction orthogonal to the processing line of the workpiece 40, and the scanning mirror is operated. (X axis) 32 and scanning mirror (Y axis) 3
6 is operated to scan the laser beam LB.

In FIG. 3, scanning control is performed so that the laser beam LB is always scanned in a direction orthogonal to the processing line 44 of the workpiece 40 placed on the processing table 16.
The state where the processing is being performed is shown.

As described above, according to the first embodiment, as shown in FIG. 3, even when the processing line 42 draws a free curve, the laser beam LB always outputs the processing line 4.
Since scanning is performed in a direction orthogonal to 2, the processing width can always be made uniform, and the heat input can be controlled evenly with respect to the processing line of the workpiece. High quality laser processing can be performed.

In the first embodiment, the condition data is set in the scanner control unit 30 in advance. However, the present invention is not limited to this. The scanner control unit 30, the oscillator control unit 22, the table control unit 18 May be set as one control device to set condition data on a machining program. This makes it possible to change the scanning amplitude, frequency, and the like of the laser beam in accordance with a change in the axis movement condition within one processing program.

(Embodiment 2) Next, Embodiment 2 will be described with reference to FIGS. Here, the same reference numerals are given to the same or equivalent components as in the first embodiment, and the description thereof will be simplified or omitted.

FIG. 4 is a block diagram of a laser processing apparatus 50 according to the second embodiment, and FIG. 5 is a view for explaining a beam shape correction state.

Laser processing apparatus 5 according to Embodiment 2
0, as shown in FIG.
A bend mirror 24 for changing a propagation path of the laser beam LB is arranged on an optical path for guiding the laser beam LB,
The point is that a beam sensor 52 as a beam shape sensor for detecting a beam diameter when the laser beam 13 is reflected by the bend mirror 24 is provided.

The specific configuration of the beam sensor 52 is as follows.
Although not shown in detail in FIG. 4, it is composed of four or more temperature sensors or four or more optical sensors, and the beam shape is deviated (for example, the elliptical beam shape shown in FIG. 5A). Is detected as an analog value based on a temperature distribution or a luminance distribution.

From the beam shape data detected by the beam sensor 52, the direction and amount of deflection of the beam are calculated by the scanner control unit 56, and the calculated data, the output command value from the oscillator control unit 22 of the beam generation unit 58, and the Are compared. The output command value from the oscillator control unit 22 includes
The beam shape data serving as a reference to be generated from the beam generation unit 58 is included.

Therefore, by comparing the beam shape data detected by the above-described beam sensor 52 with the output command value from the oscillator control unit 22 by the scanner control unit 56, the beam shape data actually output from the beam generation unit 58 is obtained. It is possible to properly determine whether or not the beam shape of the laser beam is an appropriate shape.

For example, a laser beam having an elliptical beam shape shown in FIG.
Even when scanning is performed with the same deflection width in the Y-axis direction or the horizontal direction of the paper (for example, the X-axis direction), if the beam shape itself is a vertically long elliptical shape, the processing range changes depending on the scanning direction. .

For this reason, since the beam shape close to a circle is ideal, the beam shape shown in FIG. 5A is changed to the diameter in the vertical and horizontal directions of the paper surface as shown in FIG. 5B. The laser beam is periodically oscillated so as to obtain a pseudo-circular beam shape.

Next, the operation will be described. Some laser beams LB output from the laser oscillator 20 have an elliptical beam shape depending on the type and characteristics of the laser oscillator 20. When correcting this, first, the beam diameter when the laser beam LB is reflected by the bend mirror 24 is detected by the beam sensor 52 that detects the shape of the laser beam disposed on the optical path of the laser beam LB. .

The scanner control unit 56 calculates the beam direction and the beam deflection based on the beam diameter detected by the beam sensor 52, and outputs the beam shape data and the output command value from the oscillator control unit 22. Are calculated, and the direction in which the laser beam is amplitude, the swing width thereof, and the waveform phase of each scanning axis are calculated.

As shown in FIG. 5B, this calculation result is obtained by scanning the laser beam LB in small increments in the left-right direction (scanning direction) on the paper surface to obtain a pseudo-circular beam shape. It becomes beam correction data.

The scanner controller 56 controls the scanner motor (X-axis) 34 and the scanner motor (Y-axis) in the scanner driver 28 based on the calculated beam correction data.
By controlling the driving of the scanning mirror 38 and operating the scanning mirror (X-axis) 32 and the scanning mirror (Y-axis) 36, scanning for correcting the beam shape is performed so that the beam shape becomes circular.

For example, in the second embodiment, when a workpiece is cut or welded using a laser beam whose beam shape has been corrected, the beam waist of the focused laser beam is about 0.2 mm or less. Becomes

In the case of performing the heat treatment, even if the laser beam is defocused, the beam mode is finely corrected. Therefore, the scanning amount as the correction command may be 1.0 mm or less. As described above, since the beam shape can be corrected, even when the processing direction changes, the processing groove width, the weld bead width, and the like can be kept constant without changing.

As described above, according to the second embodiment, as shown in FIG. 5A, the beam shape of the laser beam LB output from the beam generating unit 58 is biased (elliptical shape). Even when laser processing is performed while scanning the laser beam, the laser beam is finely scanned by the scanner control unit 56 in a predetermined swing width and shake direction, and the laser beam is controlled as shown in FIG. It is possible to correct the beam shape to a circular shape. Therefore, even if the processing direction or the scanning direction changes, it is possible to perform heat input control with an appropriate width with respect to the processing line of the workpiece,
Laser processing with high processing quality can be performed.

(Embodiment 3) Next, Embodiment 3 will be described with reference to FIGS. Here, the same or equivalent components as those in the first and second embodiments are denoted by the same reference numerals, and the description thereof will be simplified or omitted.

FIG. 6 is a block diagram of a laser processing apparatus 60 according to the third embodiment, and FIG. 7 is a diagram for explaining a correction state of the beam spot shape.

As described in the second embodiment,
If a beam shape is deformed like an ellipse depending on the type or characteristics of the laser oscillator 20, a beam spot BS having a certain area (shape) is formed by repeatedly drawing a certain beam locus using this beam. In this case, the beam spot shape formed according to the deformation of the beam shape may have a shape different from the beam locus. Therefore, in the third embodiment, correction is performed so that a desired beam spot shape can be obtained even if the beam shape is deformed.

The characteristic configuration of the third embodiment is that the scanner control unit 64 calculates the direction and amount of deflection of the beam based on the data of the beam diameter detected by the beam sensor 52, and calculates the ambient temperature and the laser beam. The direction in which the laser beam LB is amplitude by the scanner driving unit 28, the swing width, and the waveform phase of each scanning axis are calculated so that external factors such as a temperature rise of the bend mirror 24 due to LB are also corrected.
The point is that the scanner driving unit 28 is controlled according to the mode correction data.

Next, the operation will be described. First, the beam diameter of the laser beam generated from the beam generator 66 is detected using the same beam sensor 52 as in the second embodiment. The scanner controller 64 calculates the direction and amount of deviation of the beam based on the beam diameter detected by the beam sensor 52, and grasps the beam shape. The beam shape grasped here is the shape of the elliptical laser beam LB indicated by hatching in FIG.

Next, the scanner control unit 64 controls the scanner driving unit 28 so that the laser beam draws a constant beam locus (for example, a circle shown in FIG. 7B). As shown in the outline of the broken line in ()), when the beam shape is elliptical and the beam trajectory is circular, the beam spot BS formed is also elliptical. When scanning for processing is performed on the workpiece using the elliptical beam spot, the beam spot BS diameter is different between the vertical direction and the horizontal direction on the paper surface, so that when the scanning direction changes, the scanning width also changes, It becomes impossible to secure a stable processing width.

Therefore, in the third embodiment, the correction amount C1 for correcting the beam scanning trajectory by comparing with the outer shape (for example, a circle) of the reference beam spot BS registered in advance in the scanner controller 64 is compared. Is calculated.
Specifically, as shown in FIG. 7A, half of the difference between the vertical diameter of the elliptical shape of one laser beam LB and the horizontal diameter is correction of the outer shape of the beam spot BS. It is equal to the quantity C1.

Accordingly, the scanner control section 64 calculates the difference between the vertical diameter and the horizontal diameter of the laser beam LB grasped by the beam sensor 52, and halves the difference as the correction amount C1. The beam scanning locus is corrected as shown in FIG. The scanner motor (X-axis) 34 and the scanner motor (Y-axis) 38 in the scanner drive unit 28 are driven and controlled based on the correction amount C1, and the scanning mirror (X-axis) 32 and the scanning mirror (Y
Axis 36 is operated to scan the laser beam LB with the corrected scanning locus.

Accordingly, as shown in FIG. 7C, even if the laser beam LB used has an elliptical shape, it passes through the scanning locus of the beam corrected as shown in FIG. It is possible to have the same circular shape as the outer shape of the beam spot BS. Therefore, when scanning for processing is performed using the circular beam spot BS,
Even if the processing direction or scanning direction changes, it becomes uniform to the processing surface of the workpiece, and the heat input control can always be performed with a constant width. Laser processing can be performed.

In the third embodiment, the laser beam L
The scanning locus of the beam was corrected based on the beam shape of B, but not only the beam shape of the laser beam LB but also external factors such as the ambient temperature and the temperature rise of the bend mirror 24 caused by the laser beam LB. Thus, the amplitude direction, swing width, and waveform phase of each axis of the laser beam may be calculated.

[0075]

As described above, according to the laser processing apparatus of the present invention, even in a processing line in which the processing direction changes like a free curve, uniform heat input control can always be performed. Since laser processing can be performed, laser processing with good processing quality and no processing failure due to undercut or uneven heat input does not occur.

According to the laser processing apparatus of the next invention, even if the beam shape generated by the beam generating means is different from the reference beam shape, the laser beam is scanned with a predetermined swing width to perform pseudo correction. Therefore, appropriate heat input control to the processing line of the workpiece can be performed, and the processing quality can be improved.

According to the laser processing apparatus of the next invention, since the laser beam is corrected based on the circular beam shape data, it is possible to always perform appropriate laser processing without changing the processing width regardless of the scanning direction. it can.

According to the laser processing apparatus of the next invention, even if the shape of the beam spot obtained by scanning the laser beam with a predetermined beam locus is deformed due to the influence of the beam shape or the like, this is corrected. Since an appropriate beam spot shape can be obtained, appropriate heat input control to the processing line of the workpiece can be performed, and the processing quality can be improved.

According to the laser processing apparatus of the next invention, the beam trajectory of the laser beam is corrected based on the data of the circular beam spot shape, so that an appropriate laser beam whose processing width does not always change regardless of the scanning direction. Processing can be performed.

According to the laser processing apparatus of the next invention, since a carbon dioxide laser having a large output suitable for laser thermal processing is used for the laser oscillator, it is possible to meet the demand for uniform heat input control to the workpiece.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a laser processing apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a conceptual diagram showing a relationship between a processing speed and beam scanning.

FIG. 3 is a perspective view showing a processing line on a workpiece and a scanning direction of a laser beam.

FIG. 4 is a block diagram illustrating a schematic configuration of a laser processing apparatus according to Embodiment 2 of the present invention.

FIG. 5 is an explanatory diagram showing a correction state of a beam shape.

FIG. 6 is a block diagram showing a schematic configuration of a laser processing apparatus according to Embodiment 3 of the present invention.

FIG. 7 is an explanatory diagram showing a correction state of a beam spot shape.

FIG. 8 is a block diagram illustrating a schematic configuration of a conventional laser processing apparatus.

[Explanation of symbols]

Reference Signs List 10 laser processing device, 12 beam generating unit (beam generating unit), 14 beam scanning unit (beam scanning unit), 1
6 processing table (table), 18 table control section (table control means), 20 laser oscillator, 22 oscillator control section, 28 scanner drive section, 30 scanner control section, 40 workpiece, 42 processing line, 50 laser processing apparatus, 52 beam sensor (beam shape sensor), 5
6 Scanner controller, 58 beam generator (beam generator), LB laser beam, BS beam spot.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsushi Ono 2-6-1, Otemachi, Chiyoda-ku, Tokyo Inside Mitsubishi Electric Engineering Co., Ltd. (72) Inventor Tsutomu Usami 2--6, Otemachi, Chiyoda-ku, Tokyo 2. Mitsubishi Electric Engineering Co., Ltd. (72) Inventor Setsuo Matsubara 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation

Claims (6)

[Claims] 1. A laser processing apparatus comprising: a beam generating means for generating a laser beam; and a beam scanning means for converging a laser beam generated from the beam generating means and irradiating a workpiece while scanning the laser beam. A table on which the workpiece is placed and movable in at least two axial directions in a plane substantially orthogonal to the laser beam emitted from the beam scanning means; and A table control means for controlling the movement along the processing line, wherein the beam scanning means scans the focused laser beam with at least two orthogonal scanning axes, and a movement of the table control means The scanner so that the laser beam is always scanned in a direction orthogonal to a processing line of the workpiece based on a command value. Laser processing apparatus comprising: the scanner control unit, the controlling the moving parts. A beam shape sensor for detecting a beam shape of the laser beam generated by the beam generation means, wherein the beam generation means oscillates light and outputs a laser beam; An oscillator control unit that controls a beam output and an oscillation frequency of the laser oscillator based on an output command value.The scanner control unit includes: a beam shape data output from the beam shape sensor; and an oscillator control unit. Compare with the reference beam shape data based on the output command value,
2. The laser processing apparatus according to claim 1, wherein the scanner drive unit is controlled by deriving a command value for scanning the laser beam with a predetermined swing width so as to quasi-correctly correct the difference beam shape. 3. 3. The laser processing apparatus according to claim 2, wherein the reference beam shape data is data indicating a circular beam shape having a predetermined diameter. 4. The apparatus according to claim 1, further comprising a beam shape sensor configured to detect a beam shape of the laser beam generated by the beam generating unit, wherein the scanner controller controls the beam shape based on the beam shape data output from the beam shape sensor. The beam spot shape data obtained by scanning the laser beam having the beam shape along a predetermined beam locus is compared with the reference beam spot shape data, and the scanner driving unit is configured to correct the difference beam spot shape. 2. The laser processing apparatus according to claim 1, wherein the beam locus of the laser beam is corrected and controlled. 5. The laser processing apparatus according to claim 4, wherein the reference beam spot shape data is data indicating a circular beam spot shape having a predetermined diameter. 6. The laser processing apparatus according to claim 1, wherein said beam generating means includes a laser oscillator for generating a carbon dioxide laser.