JPH0550280A - Laser beam cutting method - Google Patents

Abstract

PURPOSE:To increase the cutting speed and to greatly improve cutting efficiency by allowing a cutting groove to effectively absorb the energy of a laser beam passing through to the rear of a material to be out thereinto. CONSTITUTION:When the material 6 to be cut is irradiated with the laser beam 1 and assisting gas is blown against the material to be cut from a cutting nozzle to perform cutting, the assisting gas produced by mixing a mist of water is blown against this from a side nozzle 5. Consequently, the energy of the laser beam 1 irradiated is absorbed into the mist of water and the energy of the laser beam 1 passing through to the rear of the material 6 to be cut is effectively absorbed into the cutting groove.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a laser cutting method.

[0002]

2. Description of the Related Art Conventionally, in laser cutting, an assist gas, that is, an inert gas for blowing molten metal or the like to keep a cut surface clean while irradiating an object to be cut with a laser beam is utilized. Oxygen for the purpose is made to flow through the cutting groove to form an efficient cutting groove, but in this case, the laser beam is not used 100% effectively, and the laser beam passes through the cutting groove to cut the object to be cut. It is missing on the back. If the laser beam emitted to the back surface can be effectively absorbed by the object to be cut and used as heat, the cutting efficiency can be further improved.

[0003]

SUMMARY OF THE INVENTION The present invention has been proposed in view of such circumstances, and a laser beam that escapes to the back surface of the object to be cut is effectively absorbed in the cutting groove to increase the cutting speed and to cut. It is an object of the present invention to provide a laser cutting method capable of greatly improving efficiency.

[0004]

To this end, the present invention is characterized in that a mist of water is mixed with the assist gas when the object to be cut is irradiated with a laser beam and the assist gas is blown to cut the object. .

[0005]

[Function] Among the laser beams, CO ₂ laser (wavelength 10.6 μm) and CO laser (wavelength about 5 μm), which have relatively long wavelengths in the infrared region, have the property of being easily absorbed by water, and YAG laser (wavelength 1.06 μm). ) Also tends to be absorbed, but there is a similar tendency.By mixing a mist of water in the assist gas, the laser beam that escapes to the back surface of the object to be cut and is no longer effectively used is absorbed by the water and the cutting groove is absorbed. Is effectively absorbed within.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the laser cutting method of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an outline of the method, and FIG. FIG. 3 is a diagram showing the relationship with the laser amount, and FIG. 3 is a diagram showing the relationship between the plate thickness and the cutting speed for showing the effect of the present method.

In FIG. 1, a laser beam 1 is focused on a material 6 to be cut by a lens 2 and irradiated through a cutting nozzle 3. At this time, the assist gas flows into the cutting nozzle 3 from the gas nozzle 4 provided in the cutting nozzle 3 and is blown to the object 6 to be cut. Further, an assist gas containing a mist of water is blown from the side nozzle 5.

The effect of mixing and blowing the mist of water into the assist gas in this way will be described with reference to FIGS. 2 and 3. As shown in FIG. 2, the laser beam 1 irradiated on the object 6 to be cut is Although 100% is not absorbed in the cutting groove, and the thinner the plate is, the more it escapes to the back surface, but by mixing the mist of water in the assist gas, the amount that escapes to the back surface can be reduced, and it is effectively absorbed in the cutting groove. This can improve the cutting speed, as shown in FIG.
The amount of the water mist added may be appropriately selected according to the material of the object 6 to be cut and the required accuracy of the cut surface, and in the case of a thin plate, it is desirable to increase it.

Thus, according to this method, when the object 6 to be cut is cut by the laser beam 1, the laser beam 1 irradiated by mixing the mist of water in the assist gas is absorbed in the mist of water. As a result, the laser beam 1 passing through the back surface of the object 6 to be cut can be effectively absorbed in the cutting groove, and the cutting speed can be increased.

[0010]

In summary, according to the present invention, when the object to be cut is irradiated with a laser beam and the assist gas is blown to cut the object, the assist gas is mixed with water mist so that the back surface of the object is cut. INDUSTRIAL APPLICABILITY The present invention is extremely useful industrially because a laser cutting method capable of effectively absorbing a laser beam passing therethrough into a cutting groove to increase the cutting speed and greatly improve the cutting efficiency.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the procedure of an embodiment of the laser cutting method of the present invention.

FIG. 2 is a diagram showing the relationship between the plate thickness and the amount of laser light passing through the back surface to show the effect of this method.

FIG. 3 is a diagram showing the relationship between plate thickness and cutting speed for showing the effect of the present method.

[Explanation of symbols]

 1 laser beam 2 lens 3 cutting nozzle 4 gas nozzle 5 side nozzle 6 object to be cut

Claims (1)

[Claims] 1. A laser cutting method, wherein a mist of water is mixed into the assist gas when the object to be cut is irradiated with a laser beam and is blown with an assist gas.