JPH0377790A - Laser beam machine - Google Patents

Abstract

PURPOSE:To find failure at early time and to enable unmanned operation having high reliability by detecting laser beam passing through cutting position at the time of cutting a material to be cut, discriminating existence of the mal- cutting based on the output thereof and informing the mal-cutting. CONSTITUTION:At the time of normally cutting the material 5 to be cut, the laser beam 2 passing through the cutting part in the material 5 to be cut from plural photoelectric converting elements set to shifting direction of a machining head 1, is detected, and pulse-like voltage signal is transmitted to a discriminating instrument, in order. Then, when the failure develops in cutting, the laser beam 2 does not pass through the material 5 to be cut and comes to shift from the material 5. By which the output of photo-detecting instrument 6 becomes zero and the discriminating instrument 7 detects the mal-cutting. By output of the discriminating instrument 7, an alarming device 8 sounds the alarm and abnormality is informed to the circumference. In such way, the unmanned operation having high reliability can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a laser processing device having a function of detecting cutting defects when cutting a material using a laser.

[Prior Art] Fig. 3 is a sectional view showing a conventional laser processing machine, in which (1) is a processing head, (2> is this processing head (
A laser beam from a laser source not shown in (1), (3
) is this laser beam (2) is a condensing lens that focuses the light on the material to be cut, which will be described later, and (4) is 02 or N that assists the cutting process.
Assist gas such as 2 and (5) are the material to be cut.

A conventional laser processing machine is configured as described above, and irradiates the workpiece (5) with a laser beam (2) focused by a condensing lens (3) together with an assist gas (4), The material to be cut (5) is cut by evaporating or melting and removing it.

[Problems to be Solved by the Invention] In the conventional laser processing machine as described above, thermal processing is performed in which the cut portion of the material to be cut is removed by evaporation or melting. For this reason, steam etc. are generated from the part to be cut during processing,
There have been problems such as poor cutting due to fluctuations in power density at the focal point due to dirt on the surface of the condenser lens or warping of the material to be cut. In particular, when unmanned operation is performed, there is a problem in that machining is performed with uncut parts remaining.

The present invention has been made to solve these problems, and an object of the present invention is to provide a highly reliable laser processing device that is capable of determining cutting defects when cutting a material to be cut, and notifying the user of the defective cutting.

[Means for Solving the Problems] A laser processing device according to the present invention includes a plurality of photoelectric conversion elements that are arranged in the scanning movement direction of a laser beam and detect a laser beam that has passed through a cutting section of a material to be cut. The present invention is provided with a detection device and a cutting defect determination/notifying means for determining a cutting defect in a material to be cut based on a signal indicating the cutting status detected by the photodetecting device and notifying the outside.

[For fil-] In the present invention, the laser beam from the material to be cut is detected by the optical detection device, and based on this detection information, the cutting defect determination and notification means determines whether the material to be cut is defective.

[Embodiment] Fig. 1 is a perspective view showing an embodiment of the laser processing apparatus according to the present invention, in which (1> to (5)) are completely the same as the conventional apparatus described above. (6) is a processing head. It is placed in the moving direction of (1) and below the workpiece (5>), and
A photodetection device (7) consisting of a plurality of photoelectric conversion elements such as photocells or optical fibers for detecting the laser beam (2) that has passed through the cutting section of 5) is electrically connected to this photodetection device (6). A discriminating device (8), which is part of a cutting defect discriminating and informing means, which discriminates whether a cut material to be cut (5) is defective based on the output signal, is electrically connected to this discriminating device (7), and is connected to the discriminating device (7). This alarm device constitutes the remainder of the defective cutting determination and notification means that notifies the outside of the defective cutting determined by the device (7).

In the case of the laser processing bag configured as above, 1
A workpiece to be cut (5) is fixed on a table (not shown), and the table is moved, for example, in the X-axis direction, and the processing head (1) is
is moved in the y-axis direction to process the material to be cut (5) into an arbitrary shape. When the material to be cut (5) is being cut normally, the processing head (1) is moved in the direction of the y-axis. direction,
That is, the laser beam (2) that passes through the cutting part of the material to be cut (5) is detected from a plurality of light 1 conversion elements arranged in the y-axis direction, and a pulsed voltage signal is sequentially sent to the discrimination device (7). If a cutting failure occurs here, for example, the laser beam (2) matures during cutting and steam is generated from the material to be cut (5) and the lens surface becomes dirty, or the material to be cut (5) is damaged due to heat. ) If a cutting defect occurs due to fluctuations in the power density at the focal point due to distortion such as warping of the laser beam (2), the laser beam (2) will not pass through the wave-cut Wr material (5) and will deviate from it. .

Therefore, the output signal of the photodetector (6) becomes zero, and the discriminator (7) can detect a cutting defect.

The alarm device (8) issues an alarm based on the output of the discriminator 1F (7) to notify the surroundings of the abnormality. In this way, highly reliable unmanned operation becomes possible.

FIG. 2 is a block diagram showing another embodiment of the present invention, (
1) to (8) are exactly the same as the apparatus shown in FIG.

(9> is a jetting fluid such as gas or water, (10) is attached near the light detection device (6), and the fluid (9>) is placed in a light detection bag!
(6) is a nozzle as a nozzle means for removing cutting fine powder from the material to be cut (5) by injecting it onto the surface of the material to be cut (5). When fine powder, steam, etc. generated from the material to be cut (5) due to the heat of the beam (2) falls and adheres to the surface of the photodetection bag W (6), a fluid such as air or water (9) is released from the nozzle (10). ) on the surface to remove those contaminants.In this way, even when the device is used for a long period of time, the detection sensitivity of the photodetector (6) can be prevented from decreasing, ensuring high reliability. Degree of light detection device ft (6)
, thus a laser processing device is obtained.

Here, when a liquid is used as the injection fluid (9) and a laser that is difficult to penetrate liquid, such as a carbon dioxide laser, the second laser source is For example, a helium neon laser may be provided as a source and used for waveguide.6 In the above embodiment, the flow #(9) is connected to the nozzle (10).
The case of spraying on the light detection device 6) was shown, but
A similar effect can be expected even if the photodetector (6) is immersed in the fluid.

[Effects] As explained above, the present invention includes a photodetection device that detects a laser beam passing through a cutting part when cutting a material to be cut, and a defective detection device that determines whether there is a defective cut based on the output of the photodetection device and notifies the user of the defective cut. By providing the cutting determination notification means, cutting defects can be detected early with a simple i-structure, and highly reliable unmanned operation is possible.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of the present invention, FIG. 2 is a perspective view showing another embodiment, and FIG. 3 is a sectional view showing a conventional laser processing machine. In the figure, (2) is a laser beam, (3) is a condensing lens, (5) is a material to be cut, (6) is a light detection device, (7) is a discrimination device, and (8) is an alarm device. In each figure, the same reference numerals indicate the same or corresponding parts. 2° L-Swim 3, Gathering Swish 5° Night Cutting Forest 6, Sandwich □□□Size

Claims (1)

[Claims] a laser beam generating means for generating a laser beam; a support base for supporting the material to be cut; an optical means for focusing and scanning the laser beam generated by the laser beam generating means on the material to be cut; a photodetection device including a plurality of photoelectric conversion elements disposed in the scanning movement direction of the laser beam and configured to detect the laser beam that has passed through the cutting section of the material to be cut; A laser processing apparatus characterized by comprising: defective cutting determination and notification means for determining defective cutting of the material to be cut based on a signal and notifying the outside.