JPS62124093A - Laser beam machine - Google Patents

Abstract

PURPOSE:To perform the cutting of a taper cross section by blowing the gas weaker than the sub-nozzle on the pack face to the cutting part about vertically in cutting the body to be worked by irradiating a laser beam in the blowing state of a co-axial assist gas. CONSTITUTION:The work head 1 which irradiates a laser beam 3 together with co-axial assisting oxygen gas A is inclined about 10 deg. behind from the vertical direction of the cut line of the body 6 to be worked. A sub-nozzle 5 is arranged by inclining it about 5 deg. behind for the cut aperture part from the back face of the body 6 to be worked as well. The cutting is performed by blowing the oxygen gas B 1/3-1/2 of the assist gas A from the sub-nozzle 5 in this state. The assist gas A is diffused at the lower side of the cut part and the cut face becomes taper. It is possible to vary the slope of the cut face and to vary in spherical shape, groove shape, etc. by the strength and weakness of the gas pressure or the bore diameter and distance of the sub-nozzle 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a laser processing device, and more particularly to a laser processing device suitable for obtaining a non-parallel, ridge-shaped cut surface.

[Background of the invention]

As a laser cutting method, for example, Japanese Patent Application Laid-Open No. 58-12539
As shown in Publication No. 1, it is known to shine a laser beam onto an inclined surface while the processing head remains fixed and vertical, and obtain a cut surface perpendicular to the inclined surface using gas from another jet nozzle. . This method can achieve the same effect as irradiating the workpiece with a laser beam from the right angle direction, but it has no effect on processing the shape of the cut surface into a tapered shape. , only parallel cut surfaces were obtained.

[Purpose of the invention]

The object of the present invention is to form a tapered (
An object of the present invention is to provide a laser processing device that can obtain a cut surface (in the shape of a square).

[Summary of the invention]

In general cutting, an assist gas such as oxygen is blown in a thin columnar flow coaxially with the laser beam, and the power of the laser beam and the reaction heat of oxygen cause the cutting to occur. We believe that if we divide the flow of columnar assist gas evenly, it will be possible to melt and cut along the flow.The assist gas is blown coaxially with the laser beam, and the sub-gas with a weak force is blown from the back side of the plate. We devised a way to split the assist gas at the bottom. The cutting width becomes wider as the width of the area receiving heat (heat of oxidation reaction) due to the assist gas due to the branch flow approaches the sub-nozzle on the back side, and a tapered cut can be made.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. 1st
The figure is a schematic cross-sectional view of the vicinity of laser cutting.

The laser processing device reflects the laser beam 3 from the laser oscillator to the workpiece 6 side by reflection 1lt8, and the processing head 1
The laser beam 3 is focused and irradiated onto the processing point using the condenser lens 2 of the laser beam 3.
Blowing assist gas A (oxygen) coaxially with the
The structure is such that subgas B (oxygen) is also blown from the back side. At this time, the processing head has an angle of 10 degrees opposite to the cutting direction with respect to the surface of the workpiece 6, that is, the laser beam 3 and assist gas A have an angle of 10 degrees, and the subgas nozzle B has an angle of 5 degrees. It has an angle. The structure is such that these gases are mixed at the cutting section, and the gas flow as seen in the direction of cutting progress is obtained as shown in FIG. The main assist gas A is blown from the arrow a to the irradiation point of the laser beam 3, superimposing it on the laser beam 3, and when a hole is made (piercing), it blows out straight to the back surface.6 However, a weak force from the back surface (assist gas Because the sub-gas is blown at 1/3 to 1/2 the force of gas A, the assist gas is separated from the center, resembling the flow of water from a fountain. When cutting is carried out under such conditions, the molten slag part 7 melted by the laser beam is also affected by the heat of the oxidation reaction of the cutting gas, and changes from the parallel columnar melting seen on a typical cut surface to a tapered shape ( This results in a V-shaped or trumpet-shaped melting, resulting in a tapered cut portion as it is. In addition, the forward flow of the assist gas in the advancing direction is weakened by 1 due to the diversion effect of the subgas, and due to interference due to collision with the wall in front of the cutting, the flow becomes smooth from top to bottom, resulting in a good cutting surface. is obtained. According to this embodiment, the laser cut surface (generally referred to as the cutting width) is narrow on the laser irradiation side and wide on the back surface, resulting in a tapered cut portion.

Furthermore, by changing the shape of the sub-nozzle and changing the flow rate and pressure of the aperture spray, it is possible to easily obtain different shapes, such as from a tapered shape to a hemispherical shape or a dome shape. According to this method, the shape of the cutting gas (assist gas) during laser cutting can be changed depending on the amount of gas blown onto the back surface. That is, if the diameter of the sub-nozzle is made thinner and the spray is applied with a pressure of 1 degree, the shape will become tapered, and if the pressure is weak, it will become acute; if the pressure is less than 1 degree, it will become obtuse. Further, if the nozzle diameter is increased, a hemispherical shape can be obtained, if the pressure is strong, a groove shape is obtained, and if the pressure is weak, a hemispherical shape is obtained, so there is an effect that the shape of the cutting width can be formed arbitrarily.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the configuration of an apparatus near a cutting section according to an embodiment of the present invention, and FIG. 2 is a conceptual diagram similarly showing the flow of cutting gas. 1... Processing head, 2... Condensing lens, 3... Laser beam, 4... Nozzle, 5... Sub-nozzle, 6
. . . Workpiece material, 7. Molten slag portion, 8. Reflector.

Claims (1)

[Claims] 1. In a processing device that cuts a workpiece by irradiating a laser beam, there is a processing head that irradiates the laser beam in a focused manner and blows a cutting gas, and a processing head that irradiates the workpiece with a focused laser beam and blows a cutting gas, and a cutting part is sandwiched between the back side of the workpiece and only the cutting gas is emitted. A laser processing device characterized by arranging spraying sub-nozzles and performing cutting by simultaneously spraying cutting gas from the processing head and the sub-nozzles.