JPH0615891U - Laser cutting machine - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent ignition in laser cutting machines,
And to prevent contamination of the optical element due to smoke generation. An irradiation point P of a laser beam LB 'from an outer side of a main nozzle 7 provided in a head 3 onto an object P to be cut.
The sub-nozzle 13 that blows out the assist gas in a direction inclined with respect to the emission direction of the laser beam LB ′ toward the vicinity
To provide. Then, the assist gas is blown out from both the main nozzle 7 and the sub nozzle 13 to generate a spiral turbulent flow, and the combustible gas generated is blown away to prevent the ignition. Further, the generated smoke is blown away in the direction opposite to the laser beam deflector 4 to prevent optical elements such as the reflection mirrors 11 and 8 and the condenser lens 9 from being exposed to the smoke and becoming dirty.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a laser cutter for cutting a sheet-like object to be cut into a desired shape by using a laser beam, and more particularly to a laser cutter for cutting flammable objects such as cloth and paper.

[0002]

[Prior art]

 In place of the conventional automatic cutting machine using a blade, a laser cutting machine has recently been used which cuts a sheet-like object to be cut into a desired shape using a laser beam. This laser cutting machine has the features that it can cut any complicated shape as instructed and can obtain a sharp cut surface without fraying in the case of cloth.

An example of such a laser cutter will be described with reference to FIGS. 2 and 3. FIG. 2 is an external view of the whole with the cover removed, and a head support that is movable along the guide groove 1a in the longitudinal direction (Y direction indicated by the arrow) of the mounting table 1 on which the object to be cut is placed. The beam 2 is laid horizontally along the width direction, and the head 3 is mounted on the head support beam 2 so as to be movable in the width direction (X direction indicated by the arrow) along the guide groove 2a. Therefore, the head 3 can freely move two-dimensionally in the X and Y directions along the cut object mounting surface 1b of the mounting table 1.

Reference numeral 4 denotes a laser beam deflector, which is attached to one end of the head support beam 2 so that no matter where the head support beam 2 and the head 3 move, the laser beam deflector 4 always emits a laser beam from a laser oscillator 5. The laser beam is incident on the head 3 and reflected twice by an internal reflection mirror to enter the head 3.

Details of the head 3 and the laser beam deflector 4 are shown in a sectional view in FIG. The head 3 is composed of a head housing 6 and a nozzle 6 fixed to the lower surface of the head housing 6 and extending vertically downward. Inside the head housing 6, a reflection mirror 8 and a condenser lens 9 are arranged. An assist gas injection pipe 10 is planted in the upper part in the radial direction.

On the other hand, in the laser beam deflector 4, a reflection mirror (not shown) that vertically deflects the laser beam horizontally incident from the laser oscillator 5 shown in FIG. 2 along the side surface of the mounting table 1 upward. ), And a reflection mirror 11 for deflecting the laser beam in the horizontal direction along the side surface of the head support beam toward the reflection mirror 8 in the head 3.

The laser emission port 4a of the laser beam deflector 4 and the laser injection port 6a of the head housing 6 are each formed in a cylindrical shape, but are opened so as not to attenuate the laser beam.

The head 3 reflects the laser beam LB that is horizontally incident from the laser beam deflector 4 by the reflection mirror 8 and deflects it vertically downward, and further, through the condenser lens 9, from the nozzle 7 to the mounting table 1. The object to be cut 12 placed on the object to be cut mounting surface 1b is emitted substantially perpendicularly, and the laser beam LB 'is focused on the irradiation point P and the object to be cut 12 is irradiated with a strong optical energy. While cutting, it moves according to the cutting shape along the cut object mounting surface 1b.

At this time, the assist gas is injected from the assist gas injection pipe 10 into the nozzle 7 as shown by the arrow, and is blown out from the tip of the nozzle 7 in the emission direction of the laser beam LB ′, whereby the laser beam The heat other than the center of LB 'is cooled to sharpen the cut point, and smoke and scattered particles generated during cutting are prevented from flowing into the nozzle 7 and polluting the condenser lens 9. ing.

[0010]

[Problems to be solved by the device]

 However, when cutting flammable objects such as cloth and paper with such a conventional laser cutting machine, flammable gas is generated due to the high heat of the laser beam focused during processing. There was a risk of fire. At that time, as shown in FIG. 3, the flame F is likely to occur behind the irradiation point P with respect to the head traveling direction Xa.

Further, if the smoke is emitted as shown in the drawing even before the ignition is reached and the smoke is uniformly spread, the smoke flows in the laser beam deflector 4 due to the flow of the smoke as shown by the streamline A. There is a risk that the reflection mirror 11 will enter and stain the reflection mirror 11, and the flow of smoke as shown by the streamline B will also enter the head 3 and stain the reflection mirror 8 and the condenser lens 9. When such an optical element is contaminated, the light amount of the laser beam is significantly reduced, and there is a possibility that cutting cannot be performed.

The present invention has been made in view of the above points, and an object thereof is to prevent ignition in such a laser cutting machine and to prevent contamination of an optical element due to smoking.

[0013]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention is directed to a laser cutting machine as described above, in which the laser beam is directed from the outside of the nozzle for emitting the laser beam provided in the head toward the irradiation point of the object to be cut of the laser beam. Ignition was prevented by providing a means for blowing out assist gas in a direction inclined with respect to the injection direction of.

The means for blowing out the assist gas from the outside of the nozzle is in a direction inclined with respect to the emission direction of the laser beam to the object to be cut, and its horizontal component is from the reflection mirror in the laser beam deflector to the head. By blowing out the assist gas along the laser beam incident direction on the optical element, not only ignition but also contamination of the optical element due to smoke can be prevented.

When the assist gas ejected from the nozzle is the first assist gas and the assist gas ejected from the outside of the nozzle is the second assist gas, the flow rate of the second assist gas is the first assist gas. It is preferable that the flow rate of the assist gas is equal to or higher than the flow rate of the assist gas, and that the flow velocity of the second assist gas is faster than that of the first assist gas.

[0016]

[Action]

 The laser cutting machine according to the present invention blows the assist gas from the nozzle of the head that emits the laser beam during the cutting process and blows the assist gas around the irradiation point on the object to be cut, and also obliquely projects the assist gas from the side of the nozzle. Since it is blown, the combustible gas generated by turbulent flow is blown away, and the ignition can be prevented.

Further, if the direction in which the assist gas is blown from the side of the nozzle is inclined with respect to the laser beam emission direction relative to the laser beam incident direction on the head, the smoke produced is emitted by the laser beam deflector. It can also be blown in the opposite direction to prevent it from flowing into the laser beam deflector or the head, and prevent the optical elements such as the internal reflection mirror and condenser lens from becoming dirty.

Further, the flow rate of the second assist gas is equal to or higher than the flow rate of the first assist gas, and the flow rate of the second assist gas is faster than that of the first assist gas. If so, a vortex-like turbulent flow is effectively generated, and the ignition prevention operation becomes remarkable.

[0019]

【Example】

 An embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a sectional view similar to FIG. 3 showing an embodiment of the present invention, but this embodiment applies the present invention to the laser cutting machine shown in FIGS. Most of them are the same as those shown in FIG. 2 and FIG. 3, and since they have already been described, only newly added portions in this embodiment will be explained.

In this embodiment, the assist gas injection pipe 10 is planted on the side of the upper portion of the nozzle 7 facing the laser beam deflector 4 in the incident direction of the laser beam L B from the reflection mirror 11 into the head 3. A sub-nozzle 13 is provided which is branched from the assist gas injection pipe 10 and extends downward close to the outer surface of the nozzle 7 (hereinafter referred to as “main nozzle”). It is slightly inclined in the incident direction of the laser beam LB along the tapered surface of the tip portion.

At the time of cutting, an assist gas is injected into the main nozzle 7 to be ejected from the main nozzle 7 in the direction of the arrow a along the emission direction of the laser beam LB ′, and from the sub nozzle 13 as well. Is a direction that is inclined with respect to the irradiation point P on the object to be cut 12 with respect to the emission direction of the laser beam LB ', and its horizontal component is a direction along the incident direction of the laser beam LB. Assist gas is ejected in the direction indicated by b.

Further, as shown in the figure, the assist gas inflow port of the main nozzle 7 is narrowed so that the main nozzle 7 and the sub nozzle 13 have the same assist gas flow rate or a larger sub gas flow rate. However, since the nozzle diameter of the sub nozzle 13 is smaller, the flow velocity of the assist gas ejected from the sub nozzle 13 is faster.

As a result, a swirl-like turbulent flow is generated by the assist gas ejected from the sub nozzle 13 and the main nozzle 7, and when the cutting object 12 is irradiated with the laser beam LB ′, the cutting process is performed. In addition, the combustible gas generated by evaporating a part of the object to be cut 12 is blown away by the turbulent flow and does not ignite.

As a result of the experiment, when the blowing of the assist gas from the main nozzle 7 is ignited, the assist gas is blown by the nozzles of two systems to cause a turbulent flow. It was confirmed to be effective.

To obtain the effect of preventing ignition, the positional relationship between the position of the sub-nozzle 13 and the laser beam deflector 4, or the direction of the assist gas blown out from the sub-nozzle 13 and the direction of incidence of the laser beam LB on the head 3. Is not particularly specified, but by making it as in the embodiment shown in FIG. 1, even if smoke is generated from the vicinity of the laser beam irradiation point P of the object to be cut 12, the smoke is generated as shown in the drawing. It is blown off by the assist gas blown out from 13, and the surrounding environment is kept in a good state without smoke.

Therefore, almost no smoke will flow into the laser beam deflector 4 and the head housing 6, and the exposure of the reflecting mirrors 11 and 8 or the condenser lens 9 to smoke will be greatly reduced. can do.

Although compressed air is easily used as the assist gas, nitrogen gas or an inert gas such as helium or argon may be used. The effect of preventing ignition is not limited to the case where the head receives the laser beam from the outside as in this embodiment, but is effective when applied to the case where the laser beam generation source is built in the head.

[0028]

[Effect of device]

 As described above, according to this invention, it is possible to prevent ignition when the flammable object is cut by the laser cutting machine. Further, it is possible to prevent the optical element such as the reflection mirror from being contaminated by smoke and becoming uncut.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a laser cutting machine showing an embodiment of the present invention.

FIG. 2 is an overall external view of the conventional laser cutter with the cover removed.

FIG. 3 is also an enlarged cross-sectional view of the relevant part.

[Explanation of symbols]

1 mounting table 2 head support beam 3
Head 4 Laser beam deflector 5 Laser oscillator 6 Head housing 7 Nozzle (main nozzle) 8, 11 Reflecting mirror 10 Assist gas injection tube 12 Cut object 13 Sub nozzle

Claims (3)

[Scope of utility model registration request] 1. A mounting table on which a material to be cut is mounted, and two-dimensionally moved on the mounting table along a surface on which the material to be cut is mounted,
A head that emits a laser beam from a nozzle in a direction substantially perpendicular to the cut object mounting surface, and an assist gas that is injected into the nozzle of the head in the nozzle in the emission direction of the laser beam. And a means for blowing assist gas in a direction inclined with respect to the emission direction of the laser beam from the outside of the nozzle toward the vicinity of the irradiation point of the object to be cut of the laser beam. A laser cutting machine characterized in that 2. A mounting table on which a material to be cut is mounted, and two-dimensionally moved on the mounting table along the surface on which the material to be cut is mounted,
A head that emits a laser beam from a nozzle in a direction substantially perpendicular to the cut object mounting surface, and a head that is arranged at a position separated from the head and that reflects a laser beam from a laser beam generation source A laser cutting machine comprising: a reflection mirror for making incident light; and means for injecting an assist gas into the nozzle of the head and blowing out the assist gas from the inside of the nozzle in the emission direction of the laser beam. The direction of the laser beam is inclined with respect to the irradiation point of the cut object with respect to the emission direction of the laser beam, and its horizontal component is along the incident direction of the laser beam from the reflection mirror to the head. A laser cutter having a means for blowing out assist gas. 3. The laser cutting machine according to claim 1, wherein the assist gas blown from the inside of the nozzle is a first assist gas, and the assist gas blown from outside the nozzle is a second assist gas, The flow rate of the second assist gas is equal to or higher than the flow rate of the first assist gas, and the flow rate of the second assist gas is faster than that of the first assist gas. Laser cutting machine.