JPS6355992A - Laser beam machining apparatus - Google Patents

Abstract

PURPOSE:To perform machining at a constant output value even if fluctuation occurs in output due to reflected light, by controlling the pulse output on the basis of the detected output value of a sensor and a preset output value. CONSTITUTION:The output value of the pulse from a laser oscillator 6 is set in an output value setter 8. The output value is detected in a sensor 7 and compared 9 with a preset value. Discharge current between electrodes 2 is variably controlled with respect to the fluctuation of the output. Therefore, machining can be carried out at the constant output value. The apparatus is especially advantageous in machining of highly reflecting material and minute machining using laser light.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a laser processing device for cutting a workpiece such as a steel plate at high speed, and more particularly.

The aim is to control the output at a constant level.

[Prior Art] Conventionally, as this type of device, for example, as shown in FIG.
There is one that uses an O2 laser oscillator. This laser oscillator uses a mixed gas (H
There are electrodes (2), (2) above and below the (1) (mixed gas such as e, H2,002, Go, etc.), and total reflection mirrors (T
A partial reflector (3) and a partial reflector (4) face each other, and the partial reflector (4) reflects part of the laser beam (5) and transmits the rest to the outside. .

When a voltage is applied between the electrodes (2) and (2) to cause a discharge, a laser beam (5) is emitted from the partially reflecting mirror (4), and the laser beam (5) is irradiated onto the workpiece through the processing head.

[Problems to be Solved by the Invention] However, as described above, in the laser processing apparatus, the oscillator output is set unilaterally with respect to the input power (see Fig. 4 (a)
), for example, when laser processing metal materials, the generated laser light is amplified by the reflected light, resulting in output fluctuations and instability as shown in Figure 4 (b). There was a problem that precision machining was not possible. Furthermore, there is a problem in that optical system components may be damaged due to the above-mentioned output fluctuations.

Therefore, the present invention has been made to solve the above-mentioned problems in the conventional example, and it is an object of the present invention to provide a laser processing apparatus that can control the laser output at a constant level.

[Means for Solving the Problems] A laser processing device according to the present invention includes a sensor that detects the output value of a laser oscillator, an output value setter that sets the output value, and the detected output value and the output setting value. and an output control device that constantly controls the output of the laser oscillator based on the above.

[Operation] The laser processing apparatus according to the present invention can eliminate output fluctuations and perform constant control using an output control device that constantly controls the laser output based on the output value detected by the sensor and the output setting value.

[Example 1] An example of the present invention will be described below with reference to the drawings. 1st
In the figure, (8) is, for example, a laser oscillator with the configuration shown in Figure 3, and (7) is a sensor that detects the pulse output of this laser oscillator (6), which has a power loss while going from the oscillator to the processing point. Therefore, it is preferable to provide it in the processing head.

Therefore, (8) is an output value setting device that sets an output value in order to constant control the pulse output of the laser oscillator (6);
indicates an output control device into which the output setting value and the output value detected by the sensor (7) are input, and this output control device is shown in FIG. Electrode (2) shown.

(2) Variably control the discharge current between the two as shown in FIG. 2(a) in response to the output fluctuations shown in FIG. 4(b).
It is designed to obtain a constant pulse output as shown in Figure (b).

Therefore, since machining can be performed with a constant output value, highly accurate machining can be performed, and in particular, machining of materials with high reflection of laser light and fine machining are possible, and the range of uses can be expanded.

In the above embodiment, the output control device (8) controls the discharge current to control the pulse output at a constant level, but in addition, the output control device (8) may also control the frequency or duty of the output pulse to control the pulse output at a constant level. You can do it like this.

[Effects of the Invention] As described above, according to the present invention, since the pulse output is controlled at a constant level based on the output value detected by the sensor and the output setting value, even if output fluctuation occurs due to reflected light, this can be eliminated. It is possible to obtain a constant output.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing an embodiment of the present invention, Figures 2 (a) and (b) are waveform diagrams of discharge current and pulse output to explain its control operation, and Figure 3 is a principle diagram of a laser oscillator. , FIGS. 4(a) and 4(b) are waveform diagrams of a conventional example corresponding to FIGS. 2(a) and (b). In the figure, (5) is the laser output, (6) is the laser oscillator, and (7
) is a sensor, (8) is an output value setting device, and (9) is an output control device. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (3)

[Claims] (1) A sensor that detects the output value of a laser oscillator, an output value setter that sets the output value, and an output control device that constantly controls the output of the laser oscillator based on the detected output value and the output setting value. A laser processing device characterized by comprising: (2) The laser processing apparatus according to claim 1, wherein the output control device outputs a control signal for controlling a discharge current between electrodes in the laser oscillator. (3) The laser processing device according to claim 1, wherein the output control device outputs a control signal for controlling the output pulse frequency or beauty of the laser oscillator.