JPS61165289A - Co2 laser beam processing machine - Google Patents

Abstract

PURPOSE:To obtain good cutting quality by placing a processing head for cutting of a combined CO2 laser beam processing machine to the final position on an optical path and placing an optical system for polarizing circularly the linearly polarized light just before said processing head. CONSTITUTION:The combined CO2 laser beam processing machine is so constituted that the linearly polarized beam 1 of the direction (a) outputted from a laser oscillator is polarized to the circularly polarized beam 4 by the optical system 3 for circular polarization on the optical path. The laser light 1 is reflected by a bent mirror 2 movable in the direction (b) perpendicular to the optical axis to process the work in the stage of a heat treatment such as hardening or welding. On the other hand, the mirror 2 is removed off the optical axis and the work is processed by reflecting the laser light 4 by a bent mirror 5 in the stage of cutting. The combined laser beam processing machine adequate for cutting is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a laser processing machine, and particularly to a carbon dioxide laser processing machine suitable for cutting.

[Background of the invention]

Conventional devices do not take into consideration the polarization of the laser beam. Therefore, when cutting metal, the quality varies depending on the cutting direction, making it difficult to perform a good cut. Incidentally, related devices of this type include, for example, "Machine and Tools J, April 1984 issue, 3-station system".

[Purpose of the invention]

An object of the present invention is to provide a composite laser processing machine that can obtain good cutting quality.

[Summary of the invention]

If the laser beam is not circularly polarized, when cutting a metal material, the absorption rate of the laser beam differs depending on the cutting direction, resulting in a problem that the cutting quality varies depending on the direction. This is because the angle of incidence of the laser beam approaches 90° during the cutting process, and the difference in absorption rate with respect to the polarization direction of the beam increases. However, when hardening, welding, etc. are performed, the incident angle of the laser beam is almost 0°, so there is almost no difference in absorption rate with respect to the polarization direction. Therefore, when performing homogeneous cutting, the laser beam must be circularly polarized, but it is not necessary to circularly polarize the laser beam when welding other than cutting or during hardening. Rather,
Since power loss is added to the optical system for circularly polarizing linearly polarized light, it is better to irradiate the beam without circularly polarizing the light.

Therefore, in a laser processing machine that performs multi-purpose processing, it is best to place the cutting processing head at the end of the optical path, and the optical system for circularly polarizing light to be placed immediately before it.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In FIG. 1, a laser beam 1 in a linearly polarized state in the a direction output from an oscillator is reflected by a pend mirror 2 movable in a direction perpendicular to the optical axis, and is used for hardening or heat treatment. The cut laser beam 4 is reflected by a bend mirror 5 and used for cutting. As shown in FIG. 2, the entire structure of the bend mirror 2 is movable on a moving rail 6 using a pneumatic cylinder (not shown). ,
A processing head 7 for hardening or welding is attached to the lower part of the bend mirror 5, and a processing head 8 for cutting is attached to the lower part of the bend mirror 5.

According to the present invention, laser light is circularly polarized only when used for cutting, and good cutting can be performed. Also,
Processing uses other than cutting are mainly heat treatment such as welding and hardening, and the processed shape is straight.

Or, it has a circumferential shape. Therefore, as shown in Fig. 3, when welding in a straight line or on a circumference using a processing table that moves the workpiece material 9 in the C direction, it is necessary to make sure that the direction of processing and the direction of linearly polarized light match. If so, the processing speed can be faster or the melt penetration can be made deeper than when processing with circularly polarized light. As shown in FIG. 4, the penetration depth d during welding is generally about 30% deeper when using linearly polarized light as shown in FIG. 4(b) than when using circularly polarized light as shown in FIG.(a). Therefore 1
According to the present invention, welding can be performed efficiently using linearly polarized light, and cutting can be performed with high quality using circularly polarized light.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention, FIG. 2 is a perspective view of the entirety of the present invention, FIG. 3 is a side view of the processed state, and FIG. 4 is a sectional view of the material to be processed. 1...Linearly polarized beam, 3...Circularly polarized optical system, 4
. . . Circularly polarized beam, 7. Processing head for welding or hardening, 8. Processing head for cutting, 9. Material to be processed. Agent: Patent attorney Akira Takahashi - Yuji Kono J. Re, 7.゛1st item

Claims (1)

[Claims] 1. In a carbon dioxide laser processing machine consisting of a carbon dioxide laser oscillator that outputs a linearly polarized beam, a cutting processing head, and a processing head other than cutting, the cutting processing head is placed at the last position on the optical path, and the linearly polarized beam is A carbon dioxide laser processing machine, characterized in that an optical system for circularly polarizing the light is placed immediately before the cutting processing head.