JPH012795A - Carbon dioxide laser processing monitor device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for monitoring the processing state of a focal position of a laser processing device.

[Conventional technology]

FIG. 4 shows an example of a conventional carbon dioxide laser processing apparatus, in which a laser oscillator (1) outputs a laser beam (2) and guides it to processing by a bend mirror (3). The processing head (4) is equipped with a processing lens (5 lenses) and a laser beam (
2) is focused and laser processing such as cutting and welding is performed on the workpiece (6).

Machining waste (7) containing oxygen, nitrogen, alcon, etc. is sent to the processing rad (4) and is blown out from the nozzle (8) coaxially with the laser beam (2) to promote laser processing. do. The hole diameter of the nozzle (3) is 1 to 2 fins, and the focal spot diameter of the laser beam is 0.1-0.2 fi, so the focal spot diameter is proportional to the nozzle diameter. The material of the machining lens (5) is Zn8e, KO, which is sufficiently small.
Use a material that is nearly transparent even under visible light, such as L.

[Problem that the invention attempts to solve]

Since the conventional carbon dioxide gas laser processing device is configured with r4 as described above, when the visible light reflected from the M workpiece (6) passes through the processing lens (5), it passes through the processing lens (5) more than the carbon dioxide laser light (2). 5) High refractive index. Therefore, the laser beam (2) is focused closer to the focal point (9). However, this focal position (9) is far away from the processing lens (5), so it is difficult to zoom in and see the processing position of the workpiece (6).
The image of the processing position of the object (6) created by the laser beam (
The beam diameter is much smaller than the beam diameter of (2), and it has been difficult with conventional equipment to monitor the state during laser processing without affecting the laser beam (2).

[Purpose of the invention]

This invention solves the above-mentioned problems. It is possible to perform precise machining by influencing the laser beam with a laser beam, and also to monitor the machining status even during machining. The purpose is to obtain a laser processing monitoring device that can perform the following tasks.

[Means for Solving the Problems] The laser processing monitoring device according to the present invention has a wavelength of visible light of 0.4 to 0.76 j cron compared to the wavelength of carbon dioxide laser light of 10.6 j cron. By taking advantage of the difference in the refractive index of the lenses, the carbon dioxide laser light and the visible light can be separated, making it possible to monitor the laser processing even during laser processing.

[Effect]

The laser machining monitor device according to the present invention separates the carbon dioxide laser beam and the visible light beam at the focal position by utilizing the fact that the refractive index of the processing lens is different between the carbon dioxide laser beam and the visible light beam.

[Embodiments of the invention]

An embodiment of the present invention will now be described with reference to the drawings. 1st
In Figure 1 and Figure 2, a laser oscillator (1) outputs a laser beam (2). The bend mirror (3) guides the laser beam (2) to the processing section (4) to perform laser processing such as cutting and welding on the workpiece (6).

In the optical path of the processed lens (5) and bend mirror (3),
A first lens αη is provided on the bend mirror (3) side, and a second lens aO is provided on the processing lens (5) side, and the laser beam (2) is focused by the first lens αυ and It diverges after the focal point (2). The focal position of the second lens αQ is set to the same position as the focal position (2) of the first lens.

The diverging laser beam (2) is returned to parallel light by the second lens aG, and is focused again by the processing lens (5), so that the position of the workpiece (6) is the focus position.

Visible light is indicated by a dotted line in the figure, and when the reflected light from the illuminator α4 from the surface of the workpiece (6) is emitted by laser processing, it passes through the processing lens (5) and the second lens 00. It is refracted more than the carbon dioxide laser beam (2).

For example, if the wavelength of carbon dioxide laser light is 10.6 < Z
The refractive index of an N8E lens is 2.40, whereas the refractive index for visible light, for example, red light from a helium neon laser with a wavelength of 0.633J chron, is 2.59. Furthermore, green has a shorter wavelength of visible light.

The refractive index becomes smaller for light such as blue. When converted to focal length, the wavelength is 0.683 for a wavelength of 10.6t chron.
The focal length of the Zn8e lens in E Cron is 0.8
It becomes 82 times. Visible light 0 is focused at the focal position (g) by the processing lens (5) and the second lens αQ. This focal position α9 is closer to the processing lens (5) than the focal position (2) of the carbon dioxide laser beam.

The visible light ray U diverges after passing the focal point Q5, and is considerably expanded by the focal point 11(2) of the carbon dioxide laser beam.

On the other hand, since the beam diameter at the focal position (2) of the carbon dioxide laser beam is 0.1 to 0.8ff, a mirror αη with a hole having a microhole Ql19 is provided at an angle to allow the carbon dioxide laser beam (2) to pass. Therefore, only visible light 0 can be reflected. The imaging lens (to) condenses the visible light a3 reflected by the micro-hole-equipped mirror αη, and forms an image at the focus position (2) of the workpiece (6) at the imaging position by the television camera α1 or the eye. Total reflection coating at the tip of the imaging lens 0-attractive carbon dioxide gas e;! By moving υ, a powerful carbon dioxide laser beam enters the television camera αl.11. You can prevent it from burning out.

The television camera α9 takes an image of visible light at the focal position of the workpiece (6), and displays it on a television screen using the control device (a). By installing this television at the operating position of laser processing, the processing status can be monitored remotely.

Figure 3 shows that the at lens @ shortens the focal length, allowing beam collimation to increase the narrow beam diameter of the incident laser beam (2) with the second lens α0, improving processing performance. can do.

Alternatively, the processed lens (5) and the second lens QO may be the same lens, and the same effect as in the above embodiment can be achieved.

〔Effect of the invention〕

As described above, the present invention includes a first lens that condenses laser light, a second lens that returns the laser light diverged by the first lens to parallel light, and a focal point of the first lens in the negative vicinity. It is configured to include a mirror with a microhole and an imaging lens, which is installed at an angle.1 This allows monitoring the state of the focus position of the workpiece during laser processing without casting a shadow on the carbon dioxide laser beam. I can do something. The state of the first round of machining and abnormal machining can be easily monitored remotely, making it possible to prevent machining failures.

Even when not machining, it is possible to align the focus position and \ with high accuracy with respect to the ζ and γ marks on the workpiece.

Furthermore, the micro-holes of the mirror with micro-holes can be made close to the diameter of the focusing port of the laser beam (-yot), and the effect of a basic filter that removes unnecessary components of the laser beam can also be maintained. There is an effect.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a laser processing monitor device according to an embodiment of the present invention, FIG. 2 is an enlarged view of the laser processing monitor device for explaining the operation of the device shown in FIG. 1, and FIG. FIG. 4 is a block diagram showing another embodiment of the invention, and FIG. 4 is a block diagram showing a conventional laser processing apparatus. In the figure, (1) is a laser oscillator, (2) is a laser beam,
(3) is a bend mirror, (4) is for processing, (5)
is the processed lens, (6) is the workpiece, (7) is the processed waste,
(8) is the nozzle, (9) (2) 09 (4) is the focal position,
QO is the second lens, aυ (goods) is the first lens, day is visible light, α4 is the illuminator, αG is a microhole, αD is a mirror with a microhole, (g) is an imaging lens, α9 is a TV Camera, η is total reflection coach ink, (A) is control lI! I accent, a is TV - In addition, in the figure, the same code is the same,
or a corresponding portion.

Claims (3)

[Claims] (1) Carbon dioxide laser processing in which the laser beam output from a carbon dioxide laser oscillator is guided to the processing head by a bend mirror, the laser beam is focused by a processing lens provided in the processing head, and the workpiece is processed at the focal position. In the equipment, in the middle of the optical path between the processing lens and the bend mirror,
A first lens is provided on the bend mirror side, a second lens is provided on the processing lens side, and a mirror with a minute hole is installed at an angle to the focal position of the first lens, and an image based on the mirror is provided. A carbon dioxide laser processing monitor device characterized by being equipped with an imaging lens that forms an image. (2) The carbon dioxide laser processing monitor device according to claim 1, wherein the imaging lens is coated with a total reflection coating for carbon dioxide laser light. (3) The carbon dioxide laser processing monitoring device according to claim 1 or 2, characterized in that a television camera is provided at the imaging position of the imaging lens, and the processing status is monitored by the television.