JPS5847587A - Laser working device - Google Patents

Abstract

PURPOSE:To improve working performance, and to obtain a smoothly cut cross section, by providing a polarizer between optical resonators of a laser working device, and controlling a direction of the polarizer so that a polarizing direction of a laser beam may conform with its working advancing direction. CONSTITUTION:A laser beam 20 is oscillated through a polarizer 19, and is reflected by a reflector 11, and is converged on the surface of a substance to be worked 17 by a lens 13. When the substance to be worked 17, and a focus of the laser beam 20 move relatively and cut-working is exectued, the polarizer 19 is turned by a polarization control motor so that this moving direction may be parallel with the polarizing direction. When the polarizer 19 rotates, the optical axis of the laser beam 20 moves circularly on the specular surface of a total reflection mirror 18. This total reflection mirror 18 is a plane mirror, therefore, the optical axis of the laser beam 20 passing through glow discharge 5 is not moved, and oscillation of the laser beam between the total reflection mirror 18 and a partial reflection mirror 7 is continued.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a laser processing device for processing a material to be processed using a laser.

Conventionally, there has been a device of this type as shown in FIG.

In the figure h (1q is a container configured in a sealed manner, and inside this container (1), He, Nt, cot, and co.

It is filled with 20 g'rorr of laser medium gas consisting of a mixed gas. Inside the container <1), a cathode stand (2) made of ceramic and a plurality of cathode pins (3), for example, are disposed.

(4) is an anode, facing the tip of the cathode pin (3), about 1
It is arranged parallel to the cathode stand (2) with a distance of t1 between the two. A voltage of approximately 0 KV is applied between the cathode pin (3) and the positive pin (4) from a DC power supply (not shown) through a stable resistor, and a glow discharge (5) is generated during this time. (7) is a partially reflective mirror, (8) t! With a total reflection mirror,
These are arranged opposite to each other so as to be sandwiched from both sides in the longitudinal direction of the space tube between the cathode pin (3) and the anode (4).
and - are respectively held by a resonator holder (6)K. Then, this partial reflection m<r>'h total reflection mirror (
8) is provided in the resonator holder (6) and is cooled by cooling water flowing through nine cooling channels. In addition, the above resonator holder (6)! There is an optical cavity spacer (not shown) made of a low thermal expansion alloy, and a partially reflecting mirror (7).
The mirror surfaces of the total reflection mirror (8) and the total reflection mirror (8) are always maintained parallel to each other. Partially reflecting mirror (7) and totally reflecting mirror (8) above
and constitute an optical resonator. Furthermore, there is a blower 1 heat exchanger (not shown) inside the container <1>! , ducts, etc. are installed, and the cathode bin (3
) and the anode (4) in a direction perpendicular to the plane of the drawing, the heated V-laser charge gas is cooled.

(9) is a cylindrical beam duct whose middle part is bent at a right angle, and is installed on the outer wall of the container (1) on the side of the partially reflecting mirror (7). A reflecting mirror 0 held by a mirror holder is disposed. and,
This reflective element is cooled by cooling water flowing through a cooling channel installed in the mirror holder 〇〇. Furthermore, a lens (to) held by a KFV lens holder (to) at the tip of the beam duct (9) is disposed, and this lens (to) connects to a cooling stub provided on the lens holder (to). It is designed to be cooled by flowing cooling water. (141 is a nozzle provided at the tip of the beam duct (9), and OB is a laser beam generated by this device.

(to) is an XY table, and this XY tape AQ* has a moving table (16a) on which the workpiece (b) is placed while maintaining a predetermined distance (approximately 1 to 2 m) from the nozzle AQ4. This moving table (16a) is equipped with an X-axis motor (161))
and -4-(16) on the Y-axis to move within a plane perpendicular to the laser beam a focused by the lens (to).
161), the Y-axis motor (160) is controlled by a numerical control device or the like.

Furthermore, when the workpiece (b) is irradiated with the laser beam (b), assist gas is supplied from the gas supply boat provided inside the nozzle tv◆ and blown out from the nozzle (b). This assist gas is generally oxygen when the workpiece (b) is a steel plate, and compressed air when the workpiece is plastic.

Next, the operation of this device will be explained.

When a laser medium gas is caused to flow between the cathode bottle (3) and the anode (4) in a direction perpendicular to the plane of the drawing, and a voltage is applied, a glow discharge (5) is generated and a laser beam (to) is generated. . This laser beam oB beam duct (
9) and is reflected by the reflecting mirror Ql) to the lens Q3.
The light is then focused through this lens and irradiated onto the workpiece. At this time, noz/Q
Assist gas is blown out from 4. If the workpiece Qh is moved together with the moving table (16a) based on this foreshadowing,
This workpiece αη is cut into a shape according to the displacement of the laser beam Ivc. This machining shape can be arbitrarily determined by a numerical control device that controls the Y-axis motor (16b) and the Y-axis motor (16Q).

By the way, there is a component in which the computer vibrates parallel to the incident plane of the laser beam KF, and a component in which it vibrates perpendicularly)
There are different absorption rates depending on these components, and this does not affect processing performance.

Furthermore, the ratio of these two components is determined by polarization. "therefore,
In the above-mentioned laser processing apparatus, since the polarization is not controlled, a randomly polarized laser beam is generated, resulting in a significant decrease in processing performance.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional technology. A polarizer is provided between the optical resonators, and the direction of the polarizer is set so that the polarization direction of the laser beam is the same as the direction of progress of processing. It is an object of the present invention to provide a laser processing device with improved processing performance by controlling the laser beams so that they match.

Hereinafter, one embodiment of the present invention will be explained with reference to FIG.
In this figure, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts, so the illustrations will be omitted.

(To) is a total reflection mirror made of a plane mirror without curvature%O is Zn
This polarizer is made of 5m long and has a prism angle of 67.4°, and this polarizer 69 is connected between the glow discharge (5) and the total reflection mirror (total) and the optical axis of the laser beam. It is held by a polarizing holder (2) rotatably provided on the inner circumference of a bearing mounted on the container (1) so that the angle formed with the plane of the polarizer is 22.6°. . , Furthermore, the bevel gear (21a
) is attached to the container (1) and is a polarization control motor (support) (22a) controlled by a numerical control device.
), and meshes with a bevel gear (2) provided in the laser beam (9), so that the rotation of the motor (2) causes the polarized light beam to rotate about an axis parallel to the laser beam (b). @
is the sealing member, and the above shirt (22a) is the container (
1) To prevent air from entering from the part that penetrates the
'I'm doing it. Note that the heat generated in the polarizer (to) is transferred to the bearing g4rc by thermal conduction, and this bearing works!
The water is cooled down by flowing waterways (not shown).

Next, the operation of this device will be explained. When a voltage is applied while flowing the laser medium gas between the anode (4) and the cathode pin (3), a gummy discharge (5) is generated, and as the laser medium gas is pumped, a small Caesar beam (E) is generated. At this time, the laser beam 4 is oscillated through the polarizer 0, so it is linearly polarized, and the direction of polarization is parallel to the plane of incidence on the polarizer Q. This laser beam 4 is reflected by a reflecting mirror (b) and focused on the surface of the workpiece i) by a lens groove (2). Next, the X-axis motor (16t) and the Y-axis motor (16K) cause the workpiece (B) to move in a curve along the plane M together with the moving table (16a), so that the focal point of the laser beam is focused. Processed product Q?
), the cutting process is performed by moving relatively over the surface. The polarizer (2) is rotated by the polarization control motor (2) so that the direction of movement is parallel to the direction of polarization. The direction of polarization is the laser beam to the polarizer DI! It corresponds to the rotation of the polarization Q because it is parallel to the plane of incidence.

Note that the polarization control motor holder is an X-axis motor (16b).

It is controlled by the NO device together with the Y-axis motor (16(3)).

Also, as the polarizer a rotates, the optical axis of the laser beam member moves circularly on the mirror surface of total internal reflection*cn, but this is due to the refraction of the polarizer axis, which is tilted at a predetermined angle. Total reflection # Ig (G) and polarizer O Even if the optical axis of the laser beam Z moves on the mirror surface of the polarizer H V (C), total reflection will occur even if the position of the laser beam member moves Since the mirror is a plane mirror, the optical axis of the laser beam ■ that passes through the glow discharge (5) does not move and is totally reflected! The oscillation of the laser beam (E) is connected between the 1011 and the partial reflecting mirror (7).

\In this way, if the tangent to the cutting curve of the workpiece Q71 and the direction of polarization of the laser beam are always parallel,
The absorption of the laser beam increases on the side in the direction in which the workpiece Qυ is processed, and the linear absorption decreases in the typical plane in the direction of movement, so the processing speed is high and the cutting width is narrow, making it possible to perform V-yap processing. Furthermore, roughness of the machined surface due to random rotation of polarized light is also eliminated.

This phenomenon occurs because the workpiece is melted with a slope in the area irradiated by the laser beam, and absorption increases as the angle of incidence of the laser beam on this slope approaches the Pleaster angle. It is something that occurs.

In the above embodiment, Z, nSe f is used for the polarizer Q'J, but CdTe%Ge or the like may also be used. Furthermore, in the above embodiment, an 8-axis orthogonal acid gas laser medium was used, but the same effect can be applied to processing equipment using laser beams such as coaxial lasers and solid-state lasers, or external resonator laser processing equipment. There is.

Furthermore, a similar effect can be obtained when a laser is used for welding.

As described above, according to the present invention, one side of the optical resonator is flattened.
By using a plane mirror and installing a polarizer between this plane mirror and the laser medium, and controlling the direction of this polarizer, the direction of laser processing and the polarization and direction of the laser beam can be changed.
I made sure it always matches.

Since the absorption on the side perpendicular to the direction of machining is increased and the absorption on the side perpendicular to the direction of machining is decreased, increasing the machining speed has the effect of obtaining a smooth cut surface with a narrow cutting width.

[Brief explanation of the drawing]

Figure g1 is a cross-sectional view showing a conventional laser processing device, g2
The figure is a sectional view showing a laser processing pass installation according to an embodiment of the present invention. In the figure, (1) is the container, (3) is the cathode bottle, (4)
is the anode, (7) is the partial reflector, (to) is the XY table,
O) is the workpiece, (to) is the total reflection i, and (to) is the umbrella wheel. In addition, the same reference numerals in each figure indicate the same or corresponding parts.
Shinichi Kuzuno "゛"""°""'"(1)"February 15, 1981 3, Claims column specification of the subject specification of the person making the amendment! Please include the scope of claims in the attached sheet.
,. What is claimed is: an optical resonator comprising a partial reflection mirror and a flat total reflection mirror and generating a laser beam i; a laser medium provided between the reflection mirrors and amplifying the laser beam; this medium portion and the flat total reflection mirror; In the booth, there is a polarizer which has a predetermined angle with the optical axis of the sea beam and is rotatable by 1.7 times, and the direction of polarization of the laser beam polarized by this polarizer is A laser processing device comprising a drive device that rotates the polarizer so as to match the processing direction of the laser beam 6r.

Claims (1)

[Claims] an optical resonator that generates a 9% laser beam consisting of a partial reflecting mirror and a flat reflecting mirror; a laser medium provided between the reflecting mirrors to amplify the laser beam; A polarizer is rotatably disposed at a predetermined angle with the optical axis of the laser beam, and a processing force is applied by which the polarization direction of the laser beam is processed by the laser beam. A laser processing device equipped with a drive device that moves the polarizer fmJ to match.