JPH0714096B2 - Laser output controller - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser output control device, and more particularly to a control device for matching a laser power output with a command value in laser processing.

2. Description of the Related Art Generally, the laser power output of a laser oscillator has the characteristics shown in FIG. That is, the laser power output is not proportional to the command voltage. In the conventional controller, as shown in FIG. 2B, the command output commanded by the NC B code is simply D / A converted, and the B code value and the command voltage have a proportional relationship. there were. Therefore, the relationship between the B code and the laser power output is also a characteristic curve that draws a curve similar to that shown in FIG. 9A, as shown in FIG. Therefore, the B code and the laser power output value did not match.

In order to solve this, a method of creating a conversion table between the power output value and the B code based on the curve of FIG. 2 (c) and selecting and inputting the B code from the conversion table at the time of output command is input. It was taken. However, this method requires a very troublesome work for the output command, and the laser power output varies slightly depending on the installation environment and time, so that it is not possible to appropriately control the laser power.

Object of the Invention and Means for Solving the Problem Here, an object of the present invention is to automatically read appropriate command voltage data from a memory on the basis of a command output to control the output, and to properly control a laser output that changes depending on the installation environment and time. It is an object of the present invention to provide a laser output control device that can be corrected and can accurately and easily match a command output and an actual power output.

Therefore, according to the present invention, command voltage data corresponding to the laser power output value measured in advance is stored in a memory, and when the output command is issued, the corresponding command voltage data is read to control the output, and the data is controlled within a predetermined range. The output correction means is provided for the internal correction.

Configuration of the Invention Hereinafter, a specific configuration of the present invention will be described with reference to the drawings.

First, FIG. 1 shows a case where the present apparatus is used in a laser processing machine, in which 1 is a laser oscillator, and half mirrors 3 and 4 are arranged on both sides of a discharge part 2 formed between an anode and a cathode. A laser power output detector 5 is provided behind the one half mirror 3. Further, the processing laser light is emitted from the other half mirror 4. Then, this laser light is applied to the workpiece W via the total reflection mirror 6. Further, a shutter 7 which can be opened and closed is provided in the optical path between the oscillator 1 and the total reflection mirror 6 so that the laser light is opened at the time of processing to allow the laser light to go straight, and closed at the time of non-processing to close the optical path so that the laser light is perpendicular It is totally reflected in the direction and guided to the damper, that is, the power cooling device 8 to absorb the laser light.

Further, 9 is an NC device as an output command means for commanding a laser power output, and a command value as a command output (here, B
Code) is pre-programmed. Reference numeral 10 is a memory consisting of a ROM or a RAM, which is provided with a data table as shown in FIG.
Command voltage data D ₁ to _N for ₁ to _N are stored. That is, the command voltage is reversed with respect to the B code as shown in FIG. 3B based on the curved laser power characteristic curve shown in FIG. 3A so that the laser power output that matches the B code is obtained. It is a data table for controlling a curved shape. Reference numeral 11 is a CPU as an output control means for reading the B code from the NC device 9, reading the corresponding data D _j from the data table of the memory 10 and outputting the value as a command voltage.

Further, 12 is a correction volume as an output correction means,
The laser power output characteristic changes depending on the change in the gas temperature in the laser oscillator 1 due to the change in the temperature between the two upper and lower broken lines as shown by the broken line in FIG. As shown by the broken line in FIG. 3 (b), the command voltage data from the CPU 11 must be further corrected within a predetermined range, which is a manual adjustment volume.

An amplifier 13 amplifies the data from the CPU 11 corrected by the volume 12, and the discharge current is controlled from the amplifier 13 to the laser oscillator 1 via the power supply 14.

Further, 15 is an operation operation surface of the laser processing machine.
Is a B code display 16 as a command display means for displaying a B code for instructing a command output input from the NC device 9 to the CPU 11, a command voltage display 17 for displaying a command voltage from the amplifier 13, and the above output detection. A laser power output display device 19 as a laser power output display means for displaying the laser power output from the device 5 via the A / D conversion circuit 18 is provided. The command voltage display 17 displays the pulse rate of the laser oscillator 1 by an internal changeover switch during normal operation.

FIG. 4 shows the operating surface 15. A power switch 20, various keyboards 21, a CRT device 22, and the B code indicator 16 located at the corner of the screen of the CRT device 22 are provided on the upper surface of the operation surface 15. Further, various switches 23 for controlling assist gas, shutters, etc., the laser power output display 19, the command voltage display 17 are provided on the lower surface of the operation surface 15.
Etc., and various adjusting knobs such as the correction volume 12 are provided.

Operation of the Invention Next, the operation of the present apparatus will be described according to the flow of FIG.

The addresses 1 to N of the memory 10 are obtained from the power output characteristics (solid line in FIG. 3 (a)) of the laser oscillator 1 actually measured from the output indicator 19 and the command voltage indicator 17 under optimum conditions. The power output values P _j and the command voltage data D _j corresponding to them are written.

First, when the B code is input from the NC device 9, the CPU 11 reads the B code, displays it on the display 16 and searches the data table of the memory 10 for the power output P _j that matches the B code and finds the address j. Is specified. Then, the command voltage data D _j as the storage data is read from the address j and output from the CPU 11. If it is not necessary to correct the output command voltage data D _{j, it} is sent to the amplifier 13 as it is, and the discharge current to the laser oscillator 1 is determined and displayed on the display unit 17.

Then, the laser power output from the laser oscillator 1 is detected by the output detector 5 through the half mirror 3 and the display 19
Is displayed in. At this time, under the optimum conditions, as shown in FIG. 3C, the B code and the power output have the same value, that is, an appropriate power output is obtained. This can be easily confirmed by both the indicators 16 and 19 on the operation surface 15.

However, if the B code display and the output display do not match when comparing both display devices 16 and 19, the power characteristic has changed, and the command voltage is adjusted by adjusting the correction volume 12. Correct and correct the power output P from the output indicator 19 to B
Match the code. As a result, the command voltage data D _{1 to DN} read from the data table of FIG. 5 are corrected to curve data corrected from the solid line in FIG. . If the corrected command voltage exceeds the maximum voltage D _max , the maximum voltage
D _max is commanded, and 0 is commanded if 0 or less. As a result, the B code and the power output can always be matched as shown in FIG.

Effects of the Invention As described above, the present invention simply uses the command output to perform A / D
Instead of converting and outputting the command voltage, the relationship between the power output and the command voltage is stored in the memory beforehand based on the power output characteristics, and the command voltage data appropriate for the command output is automatically read from the memory. Since the output is performed, 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 trouble. Further, by comparing both displays of the laser power output display means and the command output display means, the change in the laser power output characteristic can be immediately confirmed, and the data correction operation means is adjusted so that both displays coincide with each other. As a result, all the command voltage data in the memory can be properly corrected within a predetermined range along the characteristic curve, so power characteristics that fluctuate depending on the installation environment or time can be easily corrected by manual adjustment. , An appropriate power output can always be obtained, and stable high processing accuracy can be obtained in laser processing.

[Brief description of drawings]

FIG. 1 is a diagram showing an apparatus of the present invention, and FIGS. 2 (a) and (b).
(C) is a graph for explaining conventional output control,
6 (a), (b) and (c) are graphs for explaining output control according to the present invention, FIG. 4 is a front view showing an operation surface, FIG. 5 is a view showing a data table in a memory, and FIG. Is an operation flow chart. DESCRIPTION OF SYMBOLS 1 ... Laser oscillator, 5 ... Output detector, 9 ... NC device as output command means, 10 ... Memory, 11 ... CPU as output control means, 12 ... Correction volume as data correction operation means, 16 ... Command output B code display as display means,
19 ... Laser power output indicator as laser power output display means.

Claims (1)

[Claims] 1. A laser oscillator, an output detector for detecting a laser power output of the laser oscillator, an output command means for instructing the laser power output, and a laser power of the laser oscillator measured in advance by the output detector. A memory in which outputs and command voltage data corresponding thereto are stored, output control means for controlling the laser power output by reading command voltage data corresponding to the command output from the output command means from the memory, and the output Command output display means for displaying a command output from the command means, laser power output display means for displaying the laser power output detected by the output detector controlled by the output control means,
Data correction for correcting all command voltage data in the memory along the laser power output characteristic curve, and commanding the maximum voltage if the corrected command voltage exceeds the maximum voltage, and commanding 0 if it is 0 or less. A laser output control device comprising: an operating means.