JPH038593A - Laser beam machine - Google Patents

Abstract

PURPOSE:To improve machining performance by injecting fine powder together with assist gas on work surface with a laser beam machine. CONSTITUTION:The mixed gas 11 is injected toward cutting position 6a with the laser beam machine, which the laser beam 2 from a laser beam generator 1 is directionally turned with a reflecting mirror 3 and condensed with a condensing lens 5 in a nozzle 4 and radiates to the work 6, from an injection hole 13 in a mixed gas supplying device 10 for sealing the mixed gas 11 of ceramic- made micro-beads arranging plural projections and dents on surface and having 1-2mum diameter and high pressure nitrogen gas. The micro beads 14 in the mixed gas 11 are made to collide to the cutting position 6a at high velocity to bruise innumerable fine flaws at the cutting position 6a. In this result, reflecting ratio to the laser beam 2 at the cutting position 6a is lowered, and the laser beam energy is efficiently radiated and cutting efficiency is improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a laser processing machine that processes a workpiece by irradiating a laser beam onto the surface of the workpiece from a nozzle portion, and particularly relates to a laser processing machine that processes the workpiece by irradiating a laser beam from a nozzle portion onto the surface of the workpiece. Regarding an improved laser processing machine.

[Conventional technology]

A laser processing machine focuses laser light using a condensing lens or the like, irradiates it onto a single point on a workpiece, and evaporates the irradiated area to perform piercing or cutting. On the other hand, this evaporation generates plasma-like gas from the surface of the workpiece, which interferes with laser beam irradiation, so assist gas is ejected to the irradiated area to remove the plasma-like gas. Air, oxygen gas, nitrogen gas, etc. are used as the assist gas, and the optimal one is selected depending on the material of the workpiece.

[Problem to be solved by the invention]

However, for workpieces such as aluminum that have a high reflectance to the laser beam, it takes time to absorb the laser energy in the melting stage before the irradiated portion is evaporated, which limits the cutting speed.

Further, the flow rate of the assist gas cannot be increased arbitrarily because it is limited by the pressure structure of the nozzle or piping. For this reason, conventional laser processing machines cannot completely remove the plasma-like gas, so laser energy cannot be injected efficiently, and very thick workpieces cannot be cut.

The present invention has been made in view of these points, and it is an object of the present invention to provide a laser processing machine that improves the cutting performance of workpieces with high reflectance.

Another object of the present invention is to provide a laser processing machine that enables cutting of thick workpieces.

[Means to solve the problem]

In order to solve the above problems, the present invention provides a laser processing machine that processes the workpiece by irradiating the surface of the workpiece with a laser beam. There is provided a laser processing machine characterized by having a jetting means for spouting a gas mixture of There is provided a laser processing machine characterized by having a jetting means for spouting a gas mixture of powder that undergoes an oxidation reaction with a plasma-like gas generated from the irradiation part and gas at a predetermined pressure to the irradiation part.

[Effect]

By ejecting fine powder together with assist gas, it scratches the work surface and increases the absorption rate of laser light. In addition, by ejecting powder that rapidly undergoes an oxidation reaction together with assist gas, the explosive force generated when the powder undergoes an oxidation reaction with the plasma gas quickly removes the plasma gas and increases the penetration power of the laser beam. let

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a configuration diagram of a laser processing machine according to a first embodiment of the present invention. In the figure, the laser oscillator 1 is, for example, a carbon dioxide laser oscillator with 'vV' for laser outputs 2 and 3. A laser beam 2 output from a laser oscillator 1 changes direction with a folding mirror 3, is focused by a condensing lens 5 provided in a nozzle 4, and is irradiated onto a cutting location 6a of a workpiece 6 made of aluminum, for example. .

A workpiece 6 is fixed on a movable processing table 7. The movable processing table 7 is controlled by a numerical control device (not shown), and can be moved to any position on the processing table 8 in the X-axis direction and in the Y-axis direction perpendicular to the paper surface.

On the other hand, the mixed gas supply device 10 is filled with a mixed gas 11 of ceramic microbeads having a diameter of 1 to 2 μm and having many irregularities on the surface and high-pressure nitrogen gas. The mixed gas supply device 10 has a valve (not shown) that opens in synchronization with the irradiation of the laser beam 2, and the mixed gas 11 is cut off from the jet port 13 provided near the exit port 12 of the nozzle 4. It is ejected towards the location 6a. The microbeads 14 in the gas mixture 11 collide with the cut portion 6a at high speed, resulting in countless fine scratches on the cut portion 6a. As a result, the reflectance of the cutting portion 6a with respect to the laser beam 2 is reduced, laser energy is efficiently injected, and the desired cutting can be performed.

FIG. 2 is a configuration diagram of a laser processing machine according to a second embodiment of the present invention. In the figure, components given the same numbers as in FIG. 1 have the same functions, and their explanation will be omitted.

The laser beam 2 is irradiated from the exit port 21 of the nozzle 20 onto a cutting location 60a of a workpiece 60 made of an iron plate having a thickness of about 20 mrn, for example. The high-pressure gas supply device 22 is filled with an assist gas 23 such as high-pressure oxygen gas, and the powder supply device 24 is filled with, for example, iron-based powder 25 that causes a strong oxidation reaction. Further, the high-pressure gas supply device 22 has a valve (not shown), which opens in synchronization with the irradiation of the laser beam 2.
The assist gas 23 passes through the nozzle 20 and the powder 2
5 is ejected from the outlet 21 toward the cutting location 60a.

FIG. 3 is a detailed view of the nozzle 20. The nozzle 20 is provided with a connection port 26 through which the assist gas 23 is introduced, connection ports 27a and 27b through which the powder 24 is introduced, and small chambers 28a and 28b filled with the powder 24. Further, the small chambers 28a and 28b have very narrow gaps 29a and 29
b is connected to a passage 30 through which the laser beam 2 and the assist gas 23 just in front of the emission port 21 pass.

When the assist gas 23 passes through the passage 30 at high speed, the pressure in this area decreases, and the powder 24 closes in the gaps 29a and 29b.
and is ejected from the outlet 21.

The ejected powder 24 comes into contact with the plasma gas 31 generated near the cutting location 60a and rapidly causes an explosive oxidation reaction. The plasma gas 31 is removed from the surrounding area by this explosive force, and laser energy is efficiently injected into the cutting location 60a to perform cutting.

FIG. 3 is a sectional view showing details of a nozzle portion of a laser processing machine according to a second embodiment of the present invention.

〔Effect of the invention〕

As explained above, in the present invention, by ejecting fine powder together with assist gas, the surface of the workpiece is scratched and the absorption rate of laser light is increased, so it is possible to increase the cutting speed of workpieces with high reflectivity. , machining time is reduced.

In addition, by ejecting powder that rapidly undergoes an oxidation reaction together with assist gas, the explosive force generated when the powder undergoes an oxidation reaction with plasma-like gas removes the plasma gas at high speed and enhances the penetration power of the laser beam. This makes it possible to cut thick workpieces.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a laser processing machine according to a first embodiment of the present invention, and Fig. 2 is a block diagram of a laser processing machine according to a second embodiment of the present invention. 4.20 6.60 1 12.21 3 4 3 5 Rede oscillator laser light nozzle work Mixed gas outlet outlet Fine powder Assist gas powder

Claims (7)

[Claims] (1) In a laser processing machine that processes the workpiece by irradiating the surface of the workpiece with a laser beam, a gas mixture of fine powder having a predetermined hardness greater than the hardness of the workpiece and gas having a predetermined pressure is applied to the irradiation section. A laser processing machine characterized by having a jetting means that jets a jet of water. (2) The laser processing machine according to claim 1, wherein the fine powder is made of ceramics. (3) The laser processing machine according to claim 1, wherein the ejection port for ejecting the mixed gas is provided near the exit port of the nozzle section for emitting the laser beam. (4) In a laser processing machine that processes the surface of a workpiece by irradiating the surface of the workpiece with laser light, a gas mixture of powder and gas at a predetermined pressure that causes an oxidation reaction by the plasma-like gas generated from the irradiation part is generated. A laser processing machine characterized by having a jetting means for jetting into the irradiation section. (5) The laser processing machine according to claim 4, wherein the material constituting the powder contains at least iron. (6) The laser processing machine according to claim 4, wherein the exit port of the nozzle portion that emits the laser beam also serves as a jet port that jets out the mixed gas. (7) A first connection port and a second connection port that independently introduce the powder and the gas into the nozzle portion, and a mixing mechanism that mixes the powder and the gas to generate a mixed gas. 7. The laser processing machine according to claim 6, further comprising: an emitting port that also serves as the ejection port.