JP2001205472A - Laser beam machining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser beam machining device where a nozzle cleaning work is performed without stopping a laser machining to decrease the whole machining time and the re-sticking of a spatter or the like is prevented by sufficiently suppressing the splash of the spatter or the like. SOLUTION: A cleaning nozzle 31 which ejects a cleaning gas directed to the surrounding zone of a nozzle 13 which radiates a laser beam is provided. And a blow nozzle 21 which ejects a blow gas directed to the machining zone 42 of a work 41 which is machined by the laser beam is provided. Further, a spray nozzle 35 which generates an air curtain directed downwards at the opposite side of the blow nozzle 21 with respect to the nozzle 13 is provided, and spatters P which are generated at the machining part 42 and blew off by the blow nozzle 21 are forcedly dropped roughly right downwards.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus for processing a workpiece by laser light such as laser welding or laser cutting.

[0002]

2. Description of the Related Art When a laser processing apparatus is operated, sputter or dust melted by a laser beam scatters around a processing section and adheres to an outer periphery of a nozzle provided at a tip of a processing head for irradiating the laser beam. For this reason, when the amount of the deposit increases due to long-time operation or the like, the diameter of the hole of the nozzle becomes small, so that the laser beam may be blocked and desired processing may not be performed. When a capacitance type gap sensor is used for the nozzle, the value of the gap for detecting the distance between the nozzle tip and the workpiece is smaller than the actual value due to the sputtered metal powder. Will be done. Therefore, the gap between the processing head and the workpiece cannot be accurately measured by the gap sensor. Therefore, since the distance between the laser light and the surface to be processed is not kept constant, the focal position of the laser light changes,
This has led to a reduction in processing accuracy.

Therefore, conventionally, it has been necessary to clean the nozzle, that is, remove the spatter attached to the nozzle using a brush or the like. At the time of cleaning the nozzle, the laser processing operation must be temporarily stopped, and the processing time of the laser processing apparatus has been long. In particular, when piercing is performed, spatter is generated in the laser beam irradiation part, and thus the amount of the piercing adheres to the nozzle.

[0004] In addition, during laser processing, in general, molten spatter or the like is scattered around in a range of 0.3 to 0.5 m due to the force of an assist gas ejected from a nozzle. Also, when a blow nozzle is provided around the nozzle to blow out the sputter generated from the processing portion as a means for performing the piercing in a short time, the spatter is considerably large, for example, 2 to 3 m. Was splattered over a wide area. As a result, the periphery of the laser processing device becomes dirty, and in the past, a wall such as an iron plate was sometimes vertically provided on a side portion of a table of the laser processing device. However, although this does not cause the spatters to scatter outside the table, it only bounces the spatters against the wall and changes the direction of the spatters. There was a high possibility that it would adhere to the surface.

[0005] In addition, since the spatters to be scattered are high in temperature, an iron plate or the like that can be kept at a high temperature is used as a wall. However, since it is heavy and not easily movable, there has been a problem that the setup work is difficult to perform. In addition, in the case where the wall made of the iron plate is provided, a gap is provided between the suspended wall and the workpiece in a case where the workpiece corresponds to a workpiece whose surface is inclined or undulating. In order to prevent scattering of spatter and the like from the gap, some means such as providing a wall on the portion has to be taken.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of such problems existing in the prior art. Therefore, an object of the present invention is to provide a laser processing apparatus capable of cleaning a nozzle without stopping laser processing in the middle to shorten the processing time of the laser processing apparatus. It is another object of the present invention to provide a laser processing apparatus that suppresses the scattering of molten spatter that scatters around during laser processing.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 is directed to a nozzle for irradiating a laser beam to a processing portion of a workpiece, and an assist gas from the nozzle. In a laser processing apparatus having an assist gas ejecting means for ejecting, a cleaning means for ejecting a cleaning gas for cleaning the nozzle toward the periphery of the nozzle is provided. Therefore, the nozzle is cleaned by the cleaning gas ejected toward the nozzle, so that the nozzle can be cleaned during laser processing. Therefore, the laser processing does not have to be stopped to clean the nozzles, so that the entire processing time can be shortened.

According to a second aspect of the present invention, in the laser processing apparatus according to the first aspect, the cleaning means comprises:
The cleaning gas is ejected in synchronization with the piercing at the start of processing. Therefore, the cleaning is performed in synchronization with the piercing in which a large amount of dross is generated, so that the cleaning can be performed effectively.

According to a third aspect of the present invention, in the laser processing apparatus according to the first or second aspect, a blow gas for blowing off sputter generated from the processing portion is jetted toward the processing portion of the workpiece. The blow gas blowing means is provided around the nozzle. Therefore, since the blow gas is blown toward the processing portion of the workpiece during piercing, dross in the processing portion is removed. Therefore, laser processing is hardly hindered by dross, the piercing can be performed quickly, and the processing time can be greatly reduced.

According to a fourth aspect of the present invention, there is provided a laser processing apparatus having a nozzle for irradiating a laser beam toward a processing portion of a workpiece, and an assist gas jetting means for jetting an assist gas from the nozzle. Blow gas blowing means for blowing a blow gas for blowing off spatter generated from the processing portion, cleaning gas blowing means for blowing a cleaning gas for preventing spatter from adhering to the nozzle, and scattering generated and generated at the time of piercing And a spatter scattering prevention means for dropping spatter to be generated downward.

Therefore, since the nozzle can be cleaned without stopping the laser processing by the cleaning gas, the total processing time can be shortened, and
Laser processing can be performed efficiently by ejecting blow gas to the processing section, so that laser processing can be performed at high speed. In addition, since the spatter generated and scattered during the processing is dropped downward, the spatter can be almost certainly prevented from scattering, and the spatter can be prevented from adhering to the workpiece and the nozzle.

According to a fifth aspect of the present invention, there is provided a laser processing apparatus having a nozzle for irradiating a laser beam toward a processing portion of a workpiece and an assist gas jetting means for jetting an assist gas. A blow gas blowing means for blowing a blow gas that blows spatter generated from the part from the processing part, and a spatter scattering prevention means for lowering the spatter generated and scattered at the time of processing are provided. Therefore, the spatter generated and scattered during processing is dropped downward, so that the sputter blown off by the blow nozzle hardly scatters around the laser processing apparatus, and almost does not stain the circumference of the laser processing apparatus. Absent.

According to a sixth aspect of the present invention, in the laser processing apparatus according to the fourth or fifth aspect, the spatter scattering prevention means blows gas downward to form a curtain. It is what it was. Therefore, the effect of the invention of claim 5 can be achieved with a simple configuration, and since there is no need to provide a wall unlike the related art, setup work and the like can be easily performed.

According to a seventh aspect of the present invention, in the laser processing apparatus according to the fourth or fifth aspect, the spatter scattering prevention means is a mat-like member or a net-like member composed of a number of metal rods. It is like that. Therefore, even if the surface of the workpiece is inclined or undulating, there is no need to provide a gap between the laser processing apparatus and the workpiece, unlike the related art. Therefore, scattering of spatter can be more effectively prevented. The structure is also simple.

According to an eighth aspect of the present invention, in the laser processing apparatus according to any one of the fourth to seventh aspects, the spatter scattering prevention means is opposed to the blow gas blowing direction of the blow gas blowing means. It is provided in. Therefore, the drop means is provided in the direction in which the sputter is blown off by the blow nozzle, that is, in the direction in which a large amount of spatter is scattered, so that the spatter can be effectively prevented from being scattered.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described below with reference to FIG. 1, taking as an example a case where laser cutting is performed by a laser processing apparatus.

As shown in FIG. 1, in a processing head 10 of a laser processing apparatus, a nozzle 13 is fixed to a lower end of a holder 12 having a lens 11, and a nozzle opening 14 is formed at the lower end. And the laser oscillator 1
The laser light output from 5 passes through the lens 11 and is irradiated on the workpiece 41 from the nozzle port 14. Holder 1
2, a variable orifice 18 and a switching valve 17
Is connected to the assist gas supply source 16. When the switching valve 17 is opened, the assist gas supply source 16
An assist gas made of oxygen for oxidizing and melting the workpiece 41 is supplied into the holder 12 from the nozzle 12, and is ejected from the nozzle port 14 of the nozzle 13 toward the processing portion 42 of the workpiece 41.

On one side of the above-mentioned nozzle 13, a blow nozzle 21 serving as a blow gas blowing means is disposed, and a nozzle port 22 is formed at a lower end thereof. Blow nozzle 2
1 is connected to a nitrogen gas supply source 24 via a gas switching valve 23 and a variable orifice 25. When the gas switching valve 23 is opened, nitrogen gas is supplied from the nitrogen gas supply source 24 to the blow nozzle 21 and is ejected from the nozzle port 22 toward the processing portion 42 of the workpiece 41. In the present embodiment, this gas is nitrogen gas, which is for blowing off dross as a melt.

On the other side of the above-mentioned nozzle 13, a cleaning nozzle 31 as a cleaning gas jetting means is fixed to the holder 12, and a nozzle port 32 is formed at the lower end thereof. A nitrogen gas supply source 24 is connected to the inside of the cleaning nozzle 31 via a variable orifice 34 and the above-described gas switching valve 23. The cleaning nozzle 31 is supplied with a gas composed of nitrogen gas from the nitrogen gas supply source 24 in synchronization with the blow nozzle 21, and is ejected from the nozzle port 32 toward the outer periphery of the tip of the nozzle 13. This gas is a cleaning gas and the nozzle 13
This is for blowing off spatter, dust and the like adhering to the tip of the device.

A spray nozzle 35, which is a gas generator, is provided at a position separated from the processing head 10 by a predetermined distance on the extension of the nozzle port 22 of the blow nozzle 21. The spray nozzle 35 is connected to the nitrogen gas supply source 24 via the variable orifice 37 and the above-described gas switching valve 23. Therefore, the same nitrogen gas as the blow gas and the cleaning gas is jetted downward from the nozzle hole of the spray nozzle 35 in a curtain shape,
A gas jet is formed from top to bottom.

Next, the operation when piercing is performed on the workpiece 41 will be described. When a start command is issued from a control unit (not shown), the processing head 10 is moved to a position corresponding to the processing unit 42 according to a processing program. Then, an assist gas is spouted from the assist gas supply source 16 to the processing portion 42 of the workpiece 41 via the nozzle port 14 of the nozzle 13. Next, when the processing portion is filled with the assist gas (oxygen), a laser beam is applied to the processing portion 42 of the workpiece 41 to start piercing.

At the same time, the gas switching valve 23 is actuated, and the nitrogen gas
And the nitrogen gas is supplied to the spray nozzle 35. The processing part 42 formed by the laser beam by the blow gas ejected from the nozzle port 22 of the blow nozzle 21
The dross as a molten material of the hole becomes the sputter P and is blown off to the opposite side of the blow nozzle 21 via the nozzle 13. Therefore, dross in the processing part 42 is removed, a new processing surface of the processing part 42 is exposed, and the processing part 42 is exposed to the laser beam and the assist gas. In addition, at the time of piercing, since the gas switching valve 23 opens and closes a plurality of times, the blow gas is ejected intermittently a plurality of times. In addition, the machined surface is appropriately cooled by the instantaneous blowing of the blow gas, and at the same time, excessive oxidation is suppressed and generation of excess dross is suppressed. Then, the ejection of the assist gas and the irradiation of the laser light are continued on the exposed processing surface, and the piercing processing by the laser light is continued.

Then, the sputter P which has been blown to the opposite side of the blow nozzle 21 adheres to or tries to adhere to the outer peripheral surface of the lower end of the nozzle 13. At this time, since the gas switching valve 23 is open, the cleaning gas is supplied from the cleaning nozzle 31 in synchronization with the blow gas ejection timing. Therefore, the sputter P attached to the outer periphery of the nozzle 13 or the sputter P to be attached is blown off, and the sputter P is removed from the nozzle 13.

While the ashing process is continued, the nitrogen gas is supplied from the nitrogen gas supply source 24 from the spray nozzle 35 in synchronism with the supply of the blow gas and the supply of the cleaning gas, so that a curtain shape is formed from top to bottom. Is formed. Therefore, the sputter P blown off by the above-mentioned blow gas is scattered to the right in FIG. 1. In this direction, since a curtain-shaped gas jet is formed, the flow of the gas jet is Thereby, the sputter P is forcibly dropped almost immediately below.

At the end of the piercing process, that is, when the hole in the workpiece is pierced, the dross is blown downward through the hole by the assist gas. Then, when shifting to the cutting process, the processing head 10 moves in the lateral direction while maintaining the above-mentioned constant interval.
However, in this case, since the dross is scattered downward from the cut groove, the blow gas is ejected from the nozzle port 22, the cleaning gas is ejected from the nozzle port 32, and the gas is ejected from the spray nozzle 35. Is not done.

After the piercing is completed, while the machining is continued, the machining head 10 is lowered so that the interval between the nozzle port 14 and the workpiece 41 is always constant. The focus of the laser beam always coincides with the processing section 42, and the assist gas and the blow gas are ejected toward the processing surface.

Next, the effects that can be expected from the above embodiment will be described below. (A) In the present embodiment, since the cleaning gas is injected, the sputter P attached to the outer periphery of the nozzle 13 or the sputter P to be attached can be blown off by the cleaning gas for cleaning.
Therefore, there is no need to stop laser processing halfway to clean the nozzle 13, so that the processing time can be shortened and the operation time of the laser processing apparatus can be shortened.

(B) In the present embodiment, cleaning is performed in synchronization with piercing in which a large amount of dross is generated, so that nozzle cleaning can be performed effectively.

(C) In the present embodiment, since the cleaning gas is nitrogen, which is an inert gas, excessive oxidization of the processing portion 42 can be suppressed and piercing can be performed smoothly. Further, since the same nitrogen is used for the cleaning gas and the blow gas, the piping mechanism does not become complicated.

(D) In the present embodiment, since the blow gas is blown toward the processing portion 42 of the workpiece 41 during processing, dross in the processing portion is removed.
Therefore, laser processing is hardly hindered by dross, the processing can be performed efficiently, and the processing time can be reduced. In particular, since the blow gas is intermittently blown, excessive cooling can be prevented, and the processing speed can be further increased.

(E) In this embodiment, since the blow gas is nitrogen which is an inert gas, the processing unit 4
Piercing can be performed smoothly by suppressing excessive oxidation of 2.

(F) In this embodiment, since the blow nozzle 21 is provided on the opposite side of the cleaning nozzle 31 via the nozzle 13, the sputter P and dust blown off by the blow nozzle 21 are most likely to reach the nozzle 13. A cleaning gas is jetted at a portion that is likely to adhere.
Therefore, the nozzle can be more effectively cleaned.

(G) In the present embodiment, since the air curtain is formed by the spray nozzle 35, the sputter P blown off by the blow gas can be forcibly dropped almost directly below with a simple structure. Scattering of the sputter P can be prevented. Therefore, the periphery of the laser processing device is hardly stained. In addition, since scattering of spatter is prevented without providing a wall or the like, a configuration in which setup work such as replacement of a workpiece and a workpiece can be easily performed can be achieved.

(H) In the present embodiment, since the spray nozzle 35 is provided so as to face the blow direction of the blow gas from the blow nozzle 21, most of the sputter P blown off by the blow gas is scattered. Since the air curtain is formed at the position, the scattering of the spatter P can be efficiently prevented.

(I) In the present embodiment, the blow gas and the cleaning gas are the same nitrogen, and the gas blown downward by the spray nozzle 35 is also the same nitrogen. Therefore, only one gas supply source is used. You only need to provide
Since the piping mechanism is not complicated, the entire laser processing apparatus can be simplified. In addition, it is easy to synchronize and blast the blow gas, the cleaning gas, and the gas of the air curtain. By synchronizing these, it is possible to prevent wasteful use of gas and to efficiently prevent the spatter P from scattering.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. 2. The same parts as those in the first embodiment are denoted by the same reference numerals. The description is omitted.

In the present embodiment, a blow nozzle 27 for ejecting blow gas to the outer periphery of the nozzle 13 forms an annular shape and is arranged concentrically with the nozzle 13 at the tip of the processing head 20. Therefore, the nozzle port 28 of the blow nozzle 27
Blows the blow gas toward the processing portion 42 of the workpiece 41. Then, the nozzle port 28 of the blow nozzle 27
Is directed obliquely to the processing portion so that the blow gas flow is inclined with respect to the assist gas flow and converges at the processing portion 42.

On the outer periphery of the blow nozzle 27, a substantially circular gas generating device 36 is provided integrally with the processing head 20, and a plurality of holes 36a are formed on the lower surface of the gas generating device 36. Curtain-shaped gas jets are generated on the outer periphery of the nozzle. The blow nozzle 27
The gas generator 36 is connected to a nitrogen gas supply source 24 via a gas switching valve 23 and a variable orifice 26.

The operation of this embodiment is substantially the same as that of the first embodiment except that there is no dross cleaning operation, and therefore, detailed description thereof is omitted. In the present embodiment, the following effects can be obtained in addition to the effects (d) and (e) of the first embodiment.

(J) In the present embodiment, since the gas generator 36 is provided in a wide area around the blow nozzle 27, the sputter P blown off by the blow gas of the blow nozzle 27 is forcibly dropped directly below. It is possible to more reliably prevent the spatter P from scattering than in the first embodiment.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS. 3 and 4.
The same parts as those in the first and second embodiments are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, instead of providing the processing head 30 with the spray nozzle 35 of the above-described first embodiment, at a position apart from the nozzle 13, a metal member 38 made of a plurality of metal rods 38a having a cushioning property is used. Numerals 38 are three-folded and vertically suspended from a predetermined position. Further, as shown in FIG. 4, the mat-like member 38 is disposed at a position facing the blowing direction of the blow gas from the blow nozzle 21 and surrounding the nozzle 13.

Therefore, as shown in FIG. 3, similarly to the first embodiment, the sputter P generated from the processing portion 42 is blown by the blow gas to the opposite side of the blow nozzle 21 through the nozzle 13 (FIG. 3). To the right). In the present embodiment, since the above-mentioned cord-like member 38 is disposed in this direction, the spatter P scattered by this is
The scattered energy is absorbed and is forcibly dropped almost immediately below.

Therefore, in the present embodiment, the following effects can be obtained in addition to the effects (a) to (f) of the first embodiment. (K) In the present embodiment, the scattered spatter P
Comes into contact with the cushion-shaped member 38, so that its horizontal movement is absorbed and dropped downward. Therefore, the spatter hardly scatters or bounces around the laser processing device, and hardly stains the periphery of the laser processing device.

(L) In the present embodiment, the spatter P is prevented from being scattered by the mat-like member 38 made of a plurality of metal rods which withstand the heat of the spatter and have a buffering property. Even when the surface of the object is inclined or undulating, the lower end of the blind member 38 is
Are arranged along the upper surface of the. For this reason, unlike the related art, there is no need to provide a gap between the laser processing apparatus and the workpiece, so that scattering of spatter can be more effectively prevented.

(M) In this embodiment, since the mat-like members 38 are provided in a triple (multiple) manner, it is possible to more reliably prevent the spatter from scattering. (Modification) The present embodiment can be embodied with the following modifications.

In the first embodiment, the blow gas for cleaning the nozzle 13 is jetted at the start of the piercing process. However, the cleaning gas may be appropriately blown out to the nozzle 13 at predetermined time intervals. In particular, in the case of laser welding, the amount of dross generated is smaller than in the case of piercing, so that spatter P is less likely to adhere to the nozzle 13 and the frequency of blowing blow gas can be reduced. In each of the above-described embodiments, laser cutting has been described as an example. Therefore, the blow nozzles 21 and 27 are provided to
Although the dross 2 is blown off, the blow nozzles 21 and 27 may not be provided in the case of laser welding.

In the first embodiment, the spray nozzle 35 is used as a gas generator for generating curtain-shaped air. However, as another structure, for example, a shear-shaped gas generator having a porous lower surface is used. Is also good.

In the third embodiment, the scattered spatter P is forcibly dropped almost directly below.
A mat-like member 38 made of a metal rod 38a was provided in three layers.
Needless to say, the spatter P can be prevented from being scattered whether the blind member 38 is single or double.
Further, what constitutes the mat-like member 38 may be any material that sufficiently withstands the temperature of the sputter P and has a buffering property, for example, a metal net.

In each of the above embodiments, the blow gas
Although a nitrogen gas is used as the cleaning gas, another inert gas may be used, and a gas forming the air curtain may be a gas other than nitrogen, for example, compressed air. In the case where the air curtain is formed by compressed air, no special gas needs to be prepared, and the structure of the laser processing apparatus can be simplified.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a laser processing apparatus according to a first embodiment.

FIG. 2 is a sectional view of a main part of a laser processing apparatus according to a second embodiment.

FIG. 3 is a sectional view of a main part of a laser processing apparatus according to a third embodiment.

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3;

[Explanation of symbols]

13 ... Nozzles, 21, 27 ... Blow nozzles as blow gas jetting means, 31 ... Cleaning nozzles as cleaning means, 35 ... Spray nozzles as gas generators, 36 ... Gas generators, 38 ... Bird members, 38a
... metal rod, 41 ... workpiece, 42 ... processing part.

Continued on the front page (72) Inventor Yasuhiro Temma 100 Fukuno-cho, Higashi-Tonami-gun, Toyama Prefecture F-term in Tohei Plant, Hihei Toyama 3B116 AA47 AB53 BB22 BB90 4E068 AE00 AF00 CD15 CG01 CH07 CH08 CJ01

Claims (8)

[Claims] 1. A laser processing apparatus comprising: a nozzle for irradiating a laser beam toward a processing portion of a workpiece; and an assist gas jetting unit for jetting an assist gas from the nozzle. A laser processing apparatus provided with cleaning means for blowing a cleaning gas for cleaning a nozzle. 2. The laser processing apparatus according to claim 1, wherein said cleaning means ejects said cleaning gas in synchronization with piercing at the start of processing. 3. The laser according to claim 1, further comprising a blow gas ejecting means for ejecting a blow gas for blowing a sputter generated from the processing portion toward the processing portion of the workpiece, around the nozzle. Processing equipment. 4. A laser processing apparatus having a nozzle for irradiating a laser beam toward a processing portion of a workpiece and an assist gas jetting means for jetting an assist gas from the nozzle, wherein a sputter generated from the processing portion is generated. Blow gas ejecting means for ejecting blow gas to be blown off; cleaning gas ejecting means for ejecting a cleaning gas for preventing spatter from adhering to the nozzle; sputter for lowering spatter generated and scattered during piercing A laser processing apparatus provided with scattering prevention means. 5. A laser processing apparatus having a nozzle for irradiating a laser beam toward a processing portion of a workpiece and an assist gas jetting means for jetting an assist gas, wherein a sputter generated from the processing portion is processed. 1. A laser processing apparatus comprising: a blow gas blowing means for blowing a blow gas blown off from a part; and a spatter scattering prevention means for dropping spatter generated and scattered during processing downward. 6. The laser processing apparatus according to claim 4, wherein the spatter scattering prevention means is a gas generator that blows gas downward to form a curtain. 7. The spatter scattering prevention means is a cord-like member or a net-like member composed of a large number of metal rods.
Or the laser processing apparatus according to claim 5. 8. The laser processing apparatus according to claim 4, wherein said spatter scattering prevention means is provided so as to oppose a blow gas blowing direction of said blow gas blowing means.