JPH11245062A - Dust explosion preventive device in laser processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the danger of ignition/explosion caused by the heated dust of electrostatic by spraying a gas of high oxygen density to the dust generated in a step for processing a work material such as aluminum, and promoting oxidation of the dust. SOLUTION: For example, a YAG laser beam 3 for work processing is radiated from a tip of a processing nozzle 2 of a processing head 1, and an inert assist gas 4 such as air is exhausted from the periphery of the laser beam 3 at the same time. Oxygen of a gas 8 with a high oxygen density is sprayed from plural ejection holes 7 to a work metallic dust 5 which is exhausted from the cutting processing part of a work W supporting member 6 and not oxidized fully in a comparatively little amount step, so as to fully ozidize the dust at this step. The oxidation of the dust is promoted by the processing laser light and residual-heat, and the oxidation is further promoted by the gas 8. Therefore, in the following steps even if the dust is accumulated in a dust collecting duct and a dust collecting device to some extent, the danger of ignition/explosion caused by the origin of fire can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing material dust explosion prevention device in a laser beam processing device.

[0002]

2. Description of the Related Art For example, when a YAG laser processing machine or the like is used for cutting, welding, or the like of a work material having an oxidative explosive property, such as aluminum or the like, the processed metal dust (sputter) is used. In order to prevent oxidation of the end face, an inert gas such as air has been conventionally used as an assist gas.

FIG. 2 is a schematic cross-sectional view illustrating a main part of this type of laser processing section. W is a processing work material such as aluminum, and 2 is a processing nozzle of a processing head 1 of, for example, a YAG laser processing machine. A YAG laser beam 3 is focused on a processing portion of the work W from a tip end thereof, and the beam 3 is concentric. Around the inert gas such as air and assist gas 4
At the same time to prevent deterioration of the work surface of the work 1 due to oxidation or the like. Numeral 5 denotes dust (spatter) mainly generated from the work metal material powder generated during processing.

[0004] However, if the material metal dust 5 generated during the laser beam processing is deposited to some extent in a dust collection duct or a dust collection device (not shown) guided to this portion, the dust is generated. Are not substantially oxidized by inert gas, air, etc., and these become fire sources, for example, static electricity in the air, heated dust, etc., causing an oxidation reaction, which becomes an energy source of fire and explosion There was a possibility.

Conventionally, electric parts such as a terminal block of this type of processing equipment are not placed in a box, or a ground is connected to a filter, for example, in order to prevent the occurrence of such an explosive fire. In addition, various considerations have been taken to prevent accumulation of static electricity which may cause a fire.

[0006]

However, even with the above careful consideration, since these continuously generated metal dust particles themselves are not substantially oxidized from the beginning, the trace amount of the metal dust particles is small. It was not possible to eliminate the danger of fire and explosion, which could cause an oxidation reaction by the type of fire.

[0007] The present invention has been made in view of the above-described aspects, and it is an object of the present invention to oxidize these dusts in advance to a necessary minimum without excessively oxidizing and deteriorating a work surface of a work material of this kind. Accordingly, it is an object of the present invention to provide a means for preventing a dangerous ignition, explosion or the like from being caused by the fire.

[0008]

Therefore, in the present invention, the above object is achieved by providing a dust explosion prevention device according to any one of the following items (1) and (2). .

(1) An apparatus for preventing dust explosion of a laser processing apparatus, comprising means for oxidizing work material dust generated during laser beam processing immediately after the generation.

(2) The apparatus for preventing dust explosion of a laser processing apparatus according to (1), wherein the work material dust oxidizing means is a high oxygen concentration gas releasing means.

[0011]

According to the structure of the present invention as described above, a relatively small amount of dust generated in a processing stage of a work material such as aluminum generated by laser beam processing is sprayed with a gas having a high oxygen concentration to oxidize the dust. By accelerating, even if the dust is accumulated to some extent in a dust collecting duct or a dust collecting device thereafter, there is no possibility of inducing ignition / explosion or the like due to electrostatically heated dust or the like, thereby preventing danger.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail based on an embodiment with reference to the drawings.

[0013]

FIG. 1 is a cross-sectional view illustrating a main part of a dust explosion prevention apparatus for a laser beam processing section according to an embodiment of the present invention. The same components as those in FIG. 2 are denoted by the same reference numerals.

W is a processing sheet material such as aluminum, and 1 is a processing head of a laser beam processing machine. For example, a YAG laser beam 3 for processing a work is emitted from a tip end of a processing nozzle 2 of the processing head. An inert assist gas 4 such as air is released from the surroundings. 5
Is dust (sputter) mainly composed of metal powder of a work material generated during laser beam processing.

The configuration / operation up to this point is the same as that of the conventional example shown in FIG. 2, but the feature of the embodiment of the present invention is that a relatively small number of steps are released from the cutting portion of the work W indicating member 6. Oxygen or a gas 8 having a relatively high oxygen concentration is blown from the plurality of injection holes 7 to the work metal dust 5 that has not been sufficiently oxidized, and these are sufficiently oxidized at this stage. .

At this processing location, the oxidation of dust is promoted by the original processing laser light and residual heat, and the gas 8
Therefore, even if dust accumulates to some extent in a dust collection duct or a dust collection device in a later process, there is no danger of ignition / explosion by the fire.

As described above, in this embodiment, the dust generated in the processing step using the conventional assist gas is configured to be oxidized by spraying high-concentration oxygen, but the work processing end surface becomes rough or burrs are formed. In a special case where the tendency to occur is not fatal, the same ignition prevention effect can be obtained by using oxygen gas directly as the assist gas.

[0018]

As described above, according to the structure of the present invention, the material dust generated by the laser beam processing of a work material such as aluminum is oxidized, whereby the ignition caused by the oxidation reaction, The danger of explosion has been eliminated.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view of a main part of a laser processing part of a work according to an embodiment.

FIG. 2 is an explanatory cross-sectional view of a main part of a laser processing portion of a conventional work.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processing head 2 Processing nozzle 3 Laser beam 4 Assist gas 5 Dust 6 Work support member 7 Injection hole 8 Oxygen or concentrated oxygen concentration W Work material

Claims (2)

[Claims] 1. A dust explosion prevention device for a laser processing apparatus, comprising: means for oxidizing work material dust generated during laser beam processing immediately after the generation. 2. The dust explosion prevention device for a laser processing apparatus according to claim 1, wherein said work material dust oxidizing means is a high oxygen concentration gas releasing means.