JPS589785A - Laser working device - Google Patents

Abstract

PURPOSE:To position part to be worked of a work and a laser beam coaxial easily and perform highly accurate laser working by providing an element that detects reflected beam at the tip of a working head in a laser working device. CONSTITUTION:When a laser beam 2 is not irradiated on a welded part 7 of a work, most part of the laser beam 2 is reflected, and the reflected beam 11 passes through a filter 12 attached to the tip face of a working head 5, absorbed by a photoelectric element 10 and converted to an electric signal. A comparator circuit 13 compares the signal from the photoelectric element 10 with an electric signal corresponding to the welded part 7 set beforehand, and outputs the signal of difference to an arithmetic circuit 10. The arithmetic circuit 10 operates the amount of movement of a working stand 8 basing on the signal from the comparator circuit 13 and outputs a signal to a driving motor 9. The driving motor 9 is operated and welded part of the work 6 is set at the position of irradiation of the laser beam 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laser processing apparatus, and more particularly to a laser processing apparatus having a device for detecting a processed portion of a workpiece during laser processing.

In the past, there was a certain type of device that stuttered, as shown in FIG. In the figure, ol is a laser oscillator that generates a laser beam, C2) is a single laser beam output from the laser oscillator (1), and (3) is a total reflection mirror that changes the direction of the laser beam υ. (4I is the condensing lens that focuses the laser beam (21), G5 is the processing head, (6Ji is the workpiece, (7
) is the workpiece (61i workpiece part, (81Fi workpiece crystal '1 support, 6-processing table, (91tjm workbench□ゎ drive motor.) Here, the workpiece ( The case of stocking the molten !l' in the processed part (7) in 6) will be explained.

Next, the operation will be explained in detail. The laser beam (21) emitted by the laser oscillator (l) is bent by the total reflection mirror (3) to be irradiated perpendicularly to the workpiece (61).Then, the laser beam (21ti) is focused It is focused by the lens (4:) and passes through the processing head (5) to the workpiece (
6), the part to be welded (7) is irradiated. Processing head (5)
A shielding gas may be introduced to the workpiece (61) as needed, and may be injected to the workpiece (61).

Here, in order to match the part to be welded (7) of the workpiece (6) with the focused laser beam (2), the workpiece (61K) was irradiated for a short time with the low-power laser beam (2). , the welded part (7) and the laser beam (
Check the positional relationship with 21 each time.

The processing table (8) was moved by the drive motor (91) in order to align the S-contacted part (7) with the laser beam +21.

Conventional laser processing equipment is operated as described above, so it takes a long time to prepare to match the position of the laser beam with the part to be welded. The beam leaves a large amount of unnecessary traces, spoiling the appearance of the workpiece after welding, and furthermore, due to poor reliability, it is often the case that the intended welding area is not actually welded by the laser beam. This caused discrepancies with the parts that had been applied, reducing the yield of the mechanical process.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and by providing an element in the nozzle part of the processing head to detect the reflected beam from the workpiece,
Depends on the load applied to the workpiece. Fig. 2 shows one embodiment of the present invention, and in Fig. 2, 01 is a photoelectric element disposed in the nozzle part of the processing head (5), and a reflected beam from the surface of the workpiece (6) is emitted. It detects αυ, converts it into an electrical signal, and outputs it. a3 is the photoelectric element axis! ! The filter attached to the surface is made of a material that absorbs electromagnetic waves with a wavelength smaller than that of the laser beam (2). Oat; is a comparison circuit that compares the electric signal output from the photoelectric element axis with a set value and outputs a difference signal. This is an arithmetic circuit that outputs an electric signal to drive the drive motor (9).

In the figure, /11 has the same tube attached to the same part as in FIG. 1.

Next, the operation of this embodiment device will be explained. Here, a case will be described in which laser welding is performed. In the laser processing device, as shown in Fig. 2, when the laser beam C2I is not irradiated with the part to be welded (71K) of the workpiece (6), most of the laser beam (2) is reflected and 1
The reflected beam αD is transmitted with added force and becomes light! It is absorbed by element II and converted into an electrical signal. Further, the comparison circuit a3 converts the signals from the photoelectric element axis to the welded part (7) K which is set in advance from ib.
It is compared with the corresponding electric signal value and outputs the difference signal to the arithmetic circuit axis. The arithmetic circuit aa calculates the amount of movement of the processing table (8) based on the signal from the comparison circuit side and controls the drive motor (
9) Output K signal. As a result, the drive motor (9) is activated, and the welded part (1) of the workpiece (6) is set at the irradiation position of the laser beam (21).

Further, FIGS. 3 and 4 are for explaining the present invention in detail. As shown in FIG. 3(a), when the irradiation part of the laser beam (2) completely deviates from the joint part (7), the reflected beam (II) from the flat surface of the workpiece (6) If most of the current is absorbed by the photoelectric element provided above, it becomes K. Therefore, the current detected as shown in FIG. As shown in (1)), laser beam, −A (
When 11 is irradiated onto the sagging part of the textile workpiece (2), the direction of the reflected beam 9 will be irregular, and the amount of beam absorbed by the photoelectric element will also be similar to that shown in Figure 3(a) K. It becomes less.

Therefore, a current as shown in Figure 4 blis will be detected. Further KjlI1 as shown in Figure (C).

Laser beam (21 is the joint part (7) K of the workpiece (6)
When the workpiece is completely irradiated, there is almost no upward reflection of the workpiece (61), and the amount of reflected beam detected by the photoelectric element aOK is as shown in Fig. 4 cs4c; Therefore, by continuously welding the positions where the reflected beam detected by the photoelectric element 61 shows the minimum value].

Welding of the joint is achieved.

In the above embodiment, an example was shown in which Fi and the laser beam were fixed, but the weld line can also be detected even if the laser beam is vibrated or moved horizontally.

In addition, in the above embodiment, detection of the welded part in laser welding, that is, the butt joint part, was explained, but if the surface of the part to be processed has a bent part such as a marking line, cutting, drilling, trimming, etc. This invention also applies to laser processing! ! can be applied.

As described above, according to the device of the present invention, since the element for detecting one reflected beam is provided at the tip of the processing head, it is easy to make the processing part of the workpiece and the laser beam coaxial.
．． Moreover, it is possible to judge whether the laser beam irradiation position is good or bad even during laser processing, and it is possible to perform highly accurate laser processing.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a conventional laser processing device. ! FIG. 6 is a diagram showing the relationship between the distance to the beam irradiation point and the detected current corresponding thereto. (21 laser beam, (6) workpiece, (71' butt part. αυ reflected laser beam, trout photoelectric element, aυ filter. Applicant Makoto Ishiita, Director General of the Agency of Industrial Science and Technology

Claims (1)

[Claims] (1) In a laser processing device that performs laser processing by condensing and irradiating a laser beam generated by a laser oscillator onto a bent portion of a workpiece, which is the processed portion, a laser beam disposed near the output portion of the laser beam of the laser oscillator is used. a photoelectric element configured to detect a reflected beam from the surface of the workpiece and output an electric signal; a laser light transmission filter attached to the workpiece side of the photoelectric element; and an output signal from the photoelectric element. A comparison circuit that compares the reference signal corresponding to the bent portion and outputs a difference signal, and an output signal from the comparison circuit
1. A laser processing device comprising: a calculation circuit that calculates the correct position of the laser beam irradiation and outputs a signal to a drive device that corrects the position of the laser oscillator by the amount of the workpiece. +21 The laser processing apparatus according to claim 11 (claim 11), characterized in that the bent portion of the workpiece is a joint portion where the end surfaces of two workpieces abut against each other. A laser processing apparatus according to claim 12, characterized in that the welding process is performed by welding.