JPS5987996A - Laser gas cutting equipment - Google Patents

Abstract

PURPOSE:To enable high speed cutting of a thick plate with a small heat input by radiating laser light to a material to be cut within a prescribed area, and injecting the gaseous oxygen flow of a flux area smaller than the irradiated area to the center of the laser light irradiation. CONSTITUTION:Assist gas 4 is ejected from a gap 8 and laser light 1 is radiated toward a material 3 to be cut. The laser light 1 is focused to the position of a nozzle port 9 by a lens 2, and is spread in a required range around the cutting point (a) on the surface of the material 3. Then the material 3 is preheated at the cutting point (a) and the part near the same to the temp. at which combustion reaction can take place, thereby forming a firing spot. High purity gaseous oxygen 10 having regulated pressure is ejected through the nozzle port 9 to the firing spot to induce the oxidation and combustion reaction with the material 3, thereby blowing downward the formed slag. The touch 5 is then moved in an arrow (b) direction, whereby cutting is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention-5 relates to a cutting device for cutting thick plates of old material, especially mild steel, which can be cut by chemical reaction or combustion reaction of substances, using laser light and oxygen gas.

Currently, gas cutting is the mainstream method for cutting materials by combustion reaction, so-called melt cutting.

High-purity oxygen gas is applied to the cut point to burn and fuse the cut point.

In such gas cutting tL, 5 r with a mild steel plate thickness of 60 mm.
Theoretically, a cutting speed of about rt/mrn is said to be capable of cutting at a cutting speed of 0.8 to 0.0 mm with a plate thickness of 12 mm.
．． The limit is 9 m/min. This is because the heat density of the preheating flame is low and the area around the cutting point cannot be preheated at a high speed.

On the other hand, a heat source with high heat density, namely laser light,
In recent years, methods of fusing and cutting using laser light as the main cutting energy have been developed.

Fig. 1 shows an example of cutting with a laser beam, in which the laser beam (1) is focused on the cutting point by a lens (2), the cutting point of the material to be cut (3) is melted in a bath, and then air ,oxygen,
“Put the assist gas (4) such as argon or nitrogen at the cutting point i/
i”: Blows away the molten metal, and also prevents the molten metal from bouncing back with the assist gas (4). A/st gas that is not used for cutting d: Prevents the harmful effect of cooling the cutting point. Therefore, the heat of the laser beam cannot be used effectively for cutting.Furthermore, in order to cut a thick plate with a laser beam,
It requires a high-power, high-output laser oscillator, and the equipment cost is high, and the limit for high-quality processing is about 10mm plate thickness.

There is also a cutting method using oxygen plasma, but this cutting method results in a tapered cut surface and requires replacement of the electrode nozzle, resulting in poor operating efficiency. Further, it has drawbacks such as requiring a large amount of electric power and producing significant noise.

The present invention has been developed in view of the above circumstances, and is characterized by performing gas cutting while rapidly preheating the area around the cutting point using a laser beam, thereby making it possible to cut thick plates at high speed with a small heat input. It is something.

The present invention will be described in detail below with reference to the drawings.

In Fig. 2, (5) is a torch body, and the inside of the torch body is hollow, and a lens (2) is installed in the hollow part (6).
is fixed by a holder (7). Torch body (5)
The tip has an inverted conical shape, and the hollow part (6
), and a truncated inverted conical cylindrical gap (8) is formed concentric with the gap (8), and the gap (8) is connected to an assist gas source (not shown). or,
The inverted cone-shaped space at the tip partitioned by the lens (2) communicates with the outside through a nozzle/L port (9) at the top thereof, and further contains the nitrogen tH] and high-purity oxygen gas not shown in the first row. Connect to the source.

27' iVr (
6) The laser beam (1) is guided to the laser beam (1), and the focal length of the lens, the mounting position of the lens, etc. are determined so that the laser beam (1) is focused at the position of the nozzle opening (9).

Next, the operation of the present invention will be explained.

The unstuck gas (4) is ejected from the gap, and the material to be cut (3) is irradiated with the laser beam (1). Since the laser beam (1) is focused at the position of the nozzle opening (9), the surface of the new material to be WJed (3) is widened to the required range around the cutting point (,). (3) Ir to be cut by laser light (1)
The e-cutting point (cL) and its vicinity are heated until a combustion reaction is possible, creating an ignition spot. Pressure-regulated high-purity oxygen gas (10 is at the nozzle port (9) at the ignition spot. Yo!:1
gush. Oxygen gas 00 is supplied by the nozzle port (9)? It is sprayed to the center of the ignition spot, and the cutoff profit (3
) and causes an oxidative combustion reaction, and the slag formed by oxidative combustion and η is blown downward.

Then, move 1-te in the direction of arrow (b) tL i
A disconnection is made.

Here, since the irradiation area of the laser beam (1) is sufficiently wider than the cutting point (oxygen gas flux area), the portion of the laser beam that spreads out from the cutting point has a preheating effect, and moreover, the laser beam (1) ) has a high heat density, so rapid preheating is required.

Therefore, even if the torch is moved, the oxygen gas 00) will always be injected to a sufficiently preheated ignition spot, and since the preheating speed is high, even if the torch movement speed is increased, the cutting operation will be smooth. is possible.

Here, the irradiation area of the laser beam (), the intensity of the laser beam, and the pressure of the oxygen gas θ() should be taken into consideration as appropriate.

It is possible to cut up to 3 m/mtn with a board thickness of 60 mm.

viI, the above-mentioned assist gas (argon, helium, oxygen, carbon dioxide, etc.) is to prevent molten metal from rebounding or adhering to the nozzle port (9) and lens (2), and may be a low-pressure gas. .

FIG. 6 shows another embodiment of the present invention.
The light (1) is focused below the table 1T11 of the beam to be cut (3), so that the irradiation area is set to the required size.

As described above, according to the present invention, (1) Cutting is performed using a laser beam and oxygen gas; instead of cutting directly with the laser beam, only preheating is sufficient, so a low output laser is required, the amount of heat input is small, and the consumption is low. Cutting can be done with less energy ((1) Since the amount of heat consumed by one person is small, it is possible to cut with high precision and with less distortion. (+ii) Rapid preheating is possible with laser light, which greatly increases the cutting speed. I can do it (1■)
Unlike plasma cutting, there is no need to replace the electrode nozzle, so unmanned operation is possible. (V) The kerf width is small and no arc is used, unlike plasma cutting, so there is no fumes. (■1) Less noise is generated. , The tube exhibits various excellent effects.

[Brief explanation of the drawing]

Figure 1 shows the entrance gate and the second diagram showing cutting using conventional laser light.
The figures are explanatory diagrams of steps 1 and 6 for carrying out the present invention;
FIG. 6 is an explanatory diagram of another embodiment of the present invention. (1) il-loser light, (2) lens, (3) (l
j is the material to be cut, (5) is the 1-chi body, (9) is the nozzle opening, and θO is oxygen gas. Patent distributor Ishikawajima Harima Heavy Industries Co., Ltd.

Claims (1)

[Claims] 1) A laser characterized by being equipped with a lens that irradiates a laser beam in a desired area to be cut, and a nozzle opening that can inject oxygen gas to the center of irradiation of the laser beam with a flux area smaller than the irradiation area.・Gas cutting equipment.