JPS6245037B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a laser processing machine that processes materials using laser light.

Conventional configuration and its problems A laser processing machine is composed of a laser oscillator and an optical system that guides and focuses laser light.

When configuring a production system using a laser processing machine, it is necessary to be able to perform processing at several locations at the same time. For this purpose, a conventional method has been used in which a single high-output laser oscillator is provided and a beam splitter is provided in the optical system to split the laser beam, so that laser processing can be performed at several locations. A method of splitting laser light using this beam splitter will be explained with reference to FIG.

1 is a laser oscillator. 2 is a beam splitter that transmits half the laser beam and reflects the other half. 3 is a mirror that reflects the laser beam. 4 and 5 are workpieces for laser processing, respectively. 6, 7, and 8 are laser beams. A laser beam 6 oscillated by a laser oscillator 1 is split into laser beams 7 and 8 by a beam splitter 2. Laser light 7 is directly transmitted to workpiece 4 as laser light 8
is deflected by the mirror 3 and irradiated onto the workpiece 5. This laser beam splitting method using the beam splitter 2 has the following problems. First, for example, when a 100 watt laser beam is split into two, the laser beam after the split is only 50 watts.
Second, the laser beams (7 and 8) split by the beam splitter 2 all have the same ratio output. Therefore, it is not possible to change the processing conditions for each. Thirdly, the laser oscillator 1 needs to have a high output. Fourth, there is energy loss of the laser light due to the beam splitter 2,
High-power oscillators whose output cannot be divided evenly are severely damaged by mirrors, and the peak value is halved, resulting in poor processing performance.

As shown above, the laser processing machine that uses the beam splitter 2 to split laser light has many problems.

Purpose of the Invention In order to solve the above-mentioned problems and widely use a laser processing machine as a production system, the present invention has been devised to provide a laser beam processing machine that can perform any processing method at each branch point and reduces energy loss. The purpose is to provide processing machines.

Structure of the Invention When processing with a laser processing machine, it is necessary to control the output of the laser oscillator depending on the processing material and processing method (cutting, welding, microfabrication, etc.), and the present invention The above purpose is achieved by making it possible to control the output of the laser oscillator by oscillating pulses and changing the frequency and pulse duty ratio of the pulses.
comprising a laser oscillator, at least one rotating chopper mirror provided on the optical axis of the laser oscillator, and a detector for detecting a window portion and a mirror portion of the rotating chopper mirror, and based on the output waveform of the detector. By shaping the oscillation frequency and pulse duty ratio of the laser oscillator and oscillating the laser, the present invention provides a laser processing machine that can simultaneously perform a plurality of processes using a single laser oscillator.

DESCRIPTION OF EMBODIMENTS Examples of the present invention will be described below with reference to the drawings.

FIG. 2 shows an overview of a laser processing machine which is an embodiment of the present invention.

The figure shows an example of processing three workpieces with one oscillator.

In FIG. 2a, a laser oscillator 9 oscillates a laser beam 10 by oscillating pulses. 11,12
is a rotation drive section controlled by the rotation speed control device 13. Reference numerals 14 and 15 are rotating chopper mirrors, and as shown in Fig. 2b, the window portion 26 and the mirror portion 27 are made of an aluminum material with four windows opened at a ratio of 2:1, electroless nickel plated, mirror-finished, and then gold evaporated. It has a reflectance of 98% or more.

Since the rotating chopper mirror detects the window and mirror parts by laser oscillation, there is no particular problem with the hole shape, but the design is limited by the beam diameter of the laser beam, the oscillation on-time, and the rotation speed. 16 and 17 are sensors, Fig. 2c
The light emitting element 18 and the light receiving element 19 shown in FIG. 1 function to detect the presence or absence of the mirror portion 26 of the rotating chopper mirrors 14 and 15. 21 is sensor 1
This device controls the oscillation of a laser oscillator by synthesizing pulse signals based on the detection signals of 6 and 17.
22 is a reflecting mirror that deflects the laser beam. 23, 24, and 25 are workpieces processed by laser light.

The operation of this embodiment will be explained with reference to a timing chart of laser oscillation control shown in FIG. The rotation speed control device 13 causes the rotating chopper mirrors 14 and 15 to rotate at exactly the same rotation speed. Since the oscillation frequency used for processing is 20 to 220 Hz, the rotation speed of the rotary chopper mirror is 300 to 3300 rpm since four windows are used.

3. FIGS. 1 to 12 show various waveforms representing the machining operations of this embodiment, and the horizontal axis of each waveform represents time. As shown in the output waveforms of the sensors 16 and 17 in FIGS. 1 and 2, the rotating chopper mirrors 14 and 1
5 rotates with a phase shift of 1/3P. H of the output signal is a mirror portion, and L is a window portion. Figure 3 3-7
3 shows a waveform when processing is performed at three locations simultaneously with one laser oscillator, and FIG. 3 shows a pulse signal emitted from the laser oscillation control device 21 to oscillate the laser.

Based on the pulse signal shown in FIG. 3, the laser oscillator 9 emits the laser beam 10 shown in FIG. 34. Of the laser beams 10, those reflected by the mirror portion of the rotating chopper mirror 14 become laser beams 10-a shown in FIG.
used for processing.

On the other hand, among the laser beams that passed through the window of the rotating chopper mirror 14, the rotating chopper mirror 15
The laser beam reflected by the mirror section becomes laser beam 10-b shown in FIG. Then, they are guided to the workpieces 25 and subjected to processing. In this way, machining can be performed at three locations simultaneously using one oscillator. In addition, control is also possible when processing is performed at only one of the three locations and when the processing methods are different for each of the three locations, and an example will be described below.

FIG. 38 shows laser oscillation control pulses when only the workpiece material 24 is processed. As a result, the laser oscillator 9 outputs laser light with the waveform shown in FIG. 36. Since the laser beam is output only when the window portion 26 of the rotating chopper mirror 14 is on the optical axis and the mirror portion 27 of the rotating chopper mirror 15 is on the optical axis, only the workpiece 24 is irradiated with the laser beam. become.

In Figs. 3 9 to 12, the workpiece 23 is a thick plate cut;
The workpiece 24 shows waveforms when a thin plate is cut, and the workpiece 25 shows waveforms when different processes are performed, such as welding. FIG. 3 shows a laser oscillation control pulse. FIGS. 3 10 to 12 show the waveforms of the respective laser beams 10-a, 10-b, and 10-c in that case. As mentioned above, by taking advantage of the fact that the processing can be changed by changing the duty ratio of the on-time and off-time of the laser light pulse oscillation and the increase or decrease of the applied current of the laser output, it is possible to perform different processing at three locations with one oscillator. becomes possible.

Note that the output pulse from the laser oscillator 9 in this case is not limited to the waveform shown in FIG. 3 and FIG. 4, and may be, for example, intermittent, and its selection is free depending on the processing method.

It is also possible to change the processing method by changing the oscillation frequency, and in this case, this can be done by changing the rotation speed of the rotating chopper mirror.

Effects of the Invention In short, the laser processing machine of the present invention uses a rotating chopper mirror and oscillates laser pulses in synchronization with the rotation of the mirror, thereby making it possible to simultaneously process multiple locations with a single laser oscillator. Furthermore, different processing methods can be used simultaneously at each processing location. Therefore, different machining operations can be performed at multiple locations at the same time using one laser oscillator, making it possible to use the laser oscillator efficiently and improving production systems incorporating the laser processing machine of the present invention. Efficiency becomes very high.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of a conventional laser processing machine, Figure 2
Figure a is a schematic diagram of a laser processing machine that is an embodiment of the present invention, Figure 2 b is an overview diagram of the rotating chopper mirror of the above embodiment, Figure 2 c is a configuration diagram of the sensor used in the above embodiment, and Figure 2 FIG. 3 is a timing chart showing the processing operation of the laser processing machine of the present invention. 9... Laser oscillator, 10... Laser light,
11, 12... Rotation drive unit, 13... Rotation speed control device, 14, 15... Rotating chopper mirror, 1
6, 17...Sensor, 21...Laser oscillation control device, 22...Mirror, 23, 24, 25...
Work material.

Claims (1)

[Claims] 1 comprises a laser oscillator, at least one rotating chopper mirror provided on the optical axis of the laser oscillator, and a detector for detecting a window portion and a mirror portion of the rotating chopper mirror, the output waveform of the detector A laser processing machine characterized by generating a timing pulse based on the timing pulse and controlling the oscillation of a laser oscillator.