JPS62104087A - Laser output controller - Google Patents

Abstract

PURPOSE:To readily bring a command output into coincidence with the actual power output by storing command voltage data for laser power output value measured in advance, reading the corresponding command voltage data and controlling to output it. CONSTITUTION:A memory 10 writes in advance power output value Pj obtained from power output characteristic of a laser oscillator 1 actually measured in advance under the optimum conditions and corresponding command voltage data Dj. When a command value (B code) is input from an NC unit 9, CPU 11 reads out the code to indicate it on an indicator 16, searches the power output Pj coincident to the B code from the data table of the memory 10, designates the address j, reads out the command voltage data Dj, and outputs it. The data Dj is fed to an amplifier 13, and a discharge current is controlled through power source 14 by the amplifier 13 to the oscillator 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a laser output control device, and more particularly to a control device for matching laser power output with a command value in laser processing.

Conventional technology In general, the laser power output of a laser oscillator is shown in Figure 2 (
It has the characteristics shown in a). That is, the laser power output is not proportional to the command voltage. In conventional controllers, as shown in the same figure (b), a simple D/A conversion is performed on the command output instructed by the NC B code, and the value of the B code and the command voltage are in a proportional relationship. there were.

Therefore, the relationship between the B code and the laser power output also becomes a curved characteristic curve similar to that shown in FIG. 13(a), as shown in FIG. Therefore, the B code and the laser power output value did not match.

To solve this problem, a method is to create a conversion table between the power output value and the B code based on the curve in Figure 2 (C), and manually select the B code from the conversion table each time an output command is issued. It was getting worse. However, this method requires a lot of effort and effort to set the output command, and furthermore, the laser power output fluctuates to some extent depending on the day and time, so it is not possible to properly control the laser power to deal with this. There wasn't.

OBJECTS OF THE INVENTION AND SOLUTIONS THEREOF Herein, an object of the present invention is to automatically read appropriate command voltage data from memory based on the command output and control the output, and to appropriately correct the laser output that varies from day to day to time. It is an object of the present invention to provide a laser output control device that can accurately and easily match a command output with an actual power output.

Therefore, the present invention stores command voltage data corresponding to a laser power output value measured in advance in a memory, reads the corresponding command voltage data from the memory above for output commands, and controls the output. This device is equipped with a small force correction means that can correct the force within.

Composition of the invention Hereinafter, a specific configuration of the present invention will be explained based on the drawings.

First, Fig. 1 shows the case where this device is used in a laser processing machine, where 1 is a laser oscillator, half mirrors 3 and 4 are arranged on both sides of a discharge section 2 formed between an anode and a cathode, A laser power output detector 5 is provided behind one half mirror 3. Also, the other half mirror 4
Processing laser light is emitted from the. This laser light is then irradiated onto the workpiece W via the total reflection mirror 6.

In addition, a shutter 7 that can be opened and closed is provided in the optical path between the oscillator 1 and the total reflection mirror 6, and is opened during processing to allow the laser beam to proceed straight, and closed to block the optical path during non-processing to direct the laser beam at right angles. The laser beam is totally reflected in the direction and guided to a damper, that is, a power cooling device 8, where the laser beam is absorbed.

Further, 9 is an NC device as an output command means for commanding laser power output, and a command value (B code here) as a command output is programmed in advance. 10 is R
A memory consisting of OM or RAM, which is provided with a data table as shown in FIG. 5, and stores command voltage data D1-N for laser power output values P1-N measured in advance.

That is, in order to obtain a laser power output that matches the B code, the command voltage is reversed for the B code as shown in Fig. 3 (b) based on the curved laser power characteristic curve shown in Fig. 3 (a). This is a data table for controlling curved shapes. Reference numeral 11 denotes a CPU serving as an output command means for reading the B code from the NC device 9, reading the corresponding data DJ from the data table in the memory 10, and outputting the value as a command voltage.

Reference numeral 12 denotes a correction volume as an output correction means, and the laser power output characteristics vary depending on the day or time due to changes in the gas temperature in the laser oscillator 1 as shown in FIG.
) As shown by the broken line in Figure 3(b), the slope changes between the two upper and lower broken lines, so the command voltage data from the CPU II is further corrected within a predetermined range as shown by the broken line in Figure 3(b). There is a volume for manual adjustment.

13 is the CPU corrected by the volume 12 above.
This amplifier 13 is an amplifier that amplifies data from II.
The discharge current to the laser oscillator 1 is controlled via the power supply 14.

Reference numeral 15 denotes an operation surface of the laser processing machine, and this operation surface 15 includes a B code display 16 that displays the B code input from the NC device 9 to the CPL III, and a command voltage that displays the command voltage from the amplifier 13. A display 17 and an output display 19 for displaying the laser power output from the output detector 5 via the A/D converter 18 are provided. Note that the command voltage display 17 normally displays the pulse rate of the laser oscillator 1 using an internal changeover switch during normal operation.

FIG. 4 shows the operation surface 15. A power switch 20, various keyboards 21, a CRT device 22, and the above-mentioned B code display 16 are provided on the upper surface of the operation surface 15, located at a corner of the screen of the CRT device 24. Further, on the lower surface of the operation surface 15, there are various switches 23 for controlling assist gas, shutter, etc., various indicators such as the laser power output display 19, command voltage display 17, etc.
Various adjustment knobs such as a correction volume 12 are provided.

Operation of the Invention Next, the operation of this apparatus will be explained according to the flow shown in FIG.

Addresses 1 to N of the memory 10 contain information obtained from the power output characteristics of the laser oscillator 1 (solid line in FIG. 3(a)) measured in advance from the output display 19 and the command voltage display 17 under optimal conditions. The power output values PJ and the command voltage data DJ corresponding thereto are written.

First, when the B code is input from the NC device 9, the CPU
II reads the B code, displays it on the display 16, searches the data table in the memory 10 for the power output PJ that matches this B code, and specifies its address j. Then, command voltage data D as stored data is read from this address L and output from the CPU II.

If the output command voltage data DJ does not need to be corrected, it is sent as is to the amplifier 13 to determine the discharge current to the laser oscillator 1 and displayed on the display 17.

The laser power output from the laser oscillator 1 is detected by the output detector 5 via the half mirror 3 and displayed on the display 1.
9 will be displayed. At this time, under optimal conditions, the B code and the power output match in value as shown in FIG. 3(c), that is, an appropriate power output can be obtained. This can be easily confirmed by the two indicators 16.19 on the operating surface 15.

However, when comparing both displays 16 and 19, if the B code display and the output display do not match, this is due to a change in the power characteristics, and the correction volume 12 must be adjusted to adjust the command voltage. The power output P from the output display 19 is corrected to match the B code. As a result, Fig. 8(b)
Curve data corrected either upward or downward from the solid line, such as a broken line, is given. Note that if the corrected command voltage exceeds the maximum voltage D max, the maximum voltage D max
It commands x, and if it is less than or equal to 0, it commands 0. As a result, the B code and the power output can always be matched as shown in FIG. 3(c).

As described in the detailed description of the invention, the present invention simply converts the command output to the A/D.
It does not convert and output the command voltage, but stores the relationship between power output and command voltage in memory based on the power output characteristics in advance, and automatically reads the appropriate command voltage data from the memory for the command output and outputs it. As a result, the command output and the laser power output can be matched regardless of the power characteristics, and the output command can be accurately and easily controlled without requiring any effort. Furthermore, by providing an output correction means, it is possible to easily correct the power characteristics that vary depending on the day and time by manual adjustment, so that an appropriate power output can always be obtained, and a stable and high level of power can be obtained in laser processing. Machining accuracy can be obtained.

[Brief explanation of drawings]

Fig. 1 shows the apparatus of the present invention, Fig. 2 (a), (b) (
c) is a graph for explaining conventional output control; FIGS. 3(a), (b), and (c) are graphs for explaining output control according to the present invention; FIG. 4 is a front view showing the operation surface; FIG. 5 is a diagram showing a data table in the memory, and FIG. 6 is an operation flow diagram. 1... Laser oscillator, 5... Output detector, 9...
NC device as output command means, 10... memory, 1
1... CPU as output control means, 12... Correction volume as output correction means. Patent applicant Nippei Toyama Co., Ltd. Figure 1 (α) (b) (C
)(α) (b)
(C) Figure 3

Claims (2)

[Claims] (1) A laser oscillator, an output detector that detects the laser power output of this laser oscillator, an output command means that commands the laser power output, and stores the power output and command voltage data measured in advance by the output detector. 1. A laser output control device comprising: a memory for controlling a laser power output; and an output control means for reading command voltage data corresponding to a command output from the output command means from the memory to control laser power output. (2) The laser output control device according to claim 1, wherein the output control means includes means for correcting the command voltage data read from the memory within a predetermined range.