JP2004230413A - Laser beam machining method and laser beam machining device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser beam machining method and a laser beam machining device which can effectively prevent the deposition of spatters. <P>SOLUTION: A work 1 is irradiated with laser beams L through a nozzle hole 20a at a center portion of a nozzle 16, and pierced. During the piercing operation, spatter preventive agent accelerated by oxygen is injected toward the work 1 from an annular nozzle hole 22a formed in an outer side of the nozzle hole 20a. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laser processing method and a laser processing apparatus that can effectively prevent spatter adhesion during piercing processing in laser processing.
[0002]
[Prior art]
Conventionally, in laser processing, oxygen is mainly used as an assist gas to generate oxidation heat and increase the processing speed. However, when the workpiece is a stainless steel plate, for example, rusting due to oxidation of the cut surface is caused. In order to suppress, non-oxidative cutting using an inert gas other than oxygen, for example, nitrogen gas as an assist gas is performed.
[0003]
[Problems to be solved by the invention]
In laser cutting of thick plates, through-holes (piercing holes) are formed by so-called piercing as a pre-operation, but in non-oxidative cutting, there is no generation of oxidation heat as in the case of using oxygen as an assist gas. The resulting melt (spatter) has a relatively low temperature and poor fluidity, so spatter tends to adhere to the periphery of the piercing hole compared to when oxygen is used as an assist gas, which adversely affects the cutting operation and This is one of the causes of the decline in value.
[0004]
Therefore, in general, the piercing process is performed in a state where an oil-based adhesion preventing agent called an anti-sputtering agent is applied in advance to the work surface of the workpiece, but the effect is not so great when the amount of spatter generation is large. Further, there are cases where the spatter is scattered at a place where the anti-sputtering agent is not applied. In such a case, the adhesion of the spatter could not be prevented.
[0005]
This invention is made | formed in view of this situation, Comprising: It aims at providing the laser processing method and laser processing apparatus which can prevent the adhesion of a spatter more effectively.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, a laser processing method of the present invention is a laser processing method in which processing is performed by irradiating a workpiece with laser light, and an anti-spattering agent that suppresses spatter adhesion to the workpiece is provided. The processing is performed while spraying the irradiated portion of the laser beam on the workpiece.
[0007]
According to this method, not only the anti-sputtering agent is applied to the part to be processed, but also the spatter itself generated during processing is coated with the anti-sputtering agent. And, the spraying action of the spatter inhibitor acts to promote the removal of spatter, and as a result, the spatter adherence to the workpiece is effectively prevented. In particular, since the spatter inhibitor is coated against scattered spatter, adhesion of the spatter to the workpiece is more effectively prevented. Furthermore, it becomes possible to spray the anti-sputtering agent directly or indirectly onto the nozzle for laser light irradiation. As a result, in this case, it is possible to effectively prevent the spatter from adhering to the nozzle.
[0008]
On the other hand, the laser processing apparatus of the present invention has a nozzle that irradiates laser light, and in the laser processing apparatus that performs processing by irradiating the workpiece with laser light from this nozzle, spatter adheres to the workpiece. An anti-spatter agent supplying means capable of spraying the anti-spatter agent to be applied to the laser beam irradiated portion of the workpiece, and controlling the anti-sputter agent supplying means to spray the anti-sputter agent onto the workpiece during laser processing. And a control means.
[0009]
According to this apparatus, it is possible to perform processing while spraying an anti-spattering agent on the workpiece during laser processing. Therefore, it is possible to suitably obtain the above effects.
[0010]
In this configuration, the anti-spatter agent supplying means has a supply port provided integrally with the nozzle in the vicinity of the laser beam irradiation port of the nozzle, and the sputter agent is ejected from the supply port toward the workpiece. It is preferable to be configured to do so.
[0011]
According to this configuration, it is possible to spray the anti-sputtering agent well on the workpiece without complicating the structure around the nozzle that irradiates the laser beam. In this case, in particular, if an annular supply port formed concentrically with the irradiation port is provided outside the irradiation port of the laser light as the supply port, the periphery of the irradiation portion of the laser light is provided. Therefore, it is possible to spray an anti-spattering agent without any unevenness. For example, in piercing processing, it is possible to enhance the effect of preventing the adhesion of spatter around the piercing hole.
[0012]
The anti-sputtering agent supply means may be arranged near the nozzle and have a dedicated nozzle separate from the nozzle, and the anti-sputtering agent may be ejected from the dedicated nozzle. .
[0013]
According to this structure, there exists an advantage that it becomes possible to adjust independently the spraying angle and spraying distance of the sputter | spatter inhibitor with respect to a workpiece.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[0015]
FIG. 1 schematically shows a laser processing apparatus according to the present invention (a laser processing apparatus for performing the laser processing method according to the present invention).
[0016]
In this figure, reference numeral 10 denotes a processing head of a laser processing apparatus. A tip portion of the processing head 10 is roughly composed of a lens holder 14 that holds the condenser lens 12 and a nozzle 16 that is detachably attached to the tip (lower end). The laser beam L output from the oscillator is condensed by the condenser lens 12 and irradiated to a minute spot of the workpiece 1 through the nozzle 16.
[0017]
The nozzle 16 has a double structure having a central space 20 through which the laser beam L passes and a space 22 outside thereof. These spaces 20 and 22 are opened to the nozzle tip side through nozzle holes 20a and 22a, respectively. As the nozzle 16, a plurality of types of nozzles 16 classified according to the shape of the nozzle hole and the like are selectively used, and can be selectively used according to processing conditions.
[0018]
The nozzle 16 is provided with a first port 18a that communicates with the space 20 at the center of the nozzle and a second port 18b that communicates with the other space 22 (hereinafter referred to as the outer space 22). An assist gas supply pipe 26 is connected to the first port 18a, and an anti-spatter supply pipe 28 is connected to the second port 18b.
[0019]
The assist gas supply pipe 26 communicates with an assist gas supply source (not shown), and a control valve 32 including an electromagnetic valve is provided in the middle of the assist gas supply pipe 26. The control valve 32 is controlled to open and close as described above. The assist gas is configured to be supplied to the space 20 in the central portion of the nozzle through the first port 18a.
[0020]
The anti-spatter agent supply pipe 28 is derived from an acceleration gas supply source (not shown) serving as a medium gas and connected to the second port 18b, and a branch pipe that joins the middle part of the main pipe 28a. 28b.
[0021]
The main pipe 28a is provided with a control valve 34 comprising an electromagnetic valve and an accelerator 35 in order from the upstream side. The branch pipe 28b led out from the anti-spatter agent mist generator 36 is connected to the accelerator 35. Yes.
[0022]
The acceleration device 35 is composed of, for example, an aspirator, and accelerates by accelerating the spattering agent mist formed in the spattering agent mist generation device while sucking it using the flow of gas supplied from the acceleration gas supply source. Is configured to do. The anti-sputtering agent is a well-known water-soluble liquid composed of purified water, glycols, and other components. In this embodiment, for example, laser sputtering non-touch water-soluble No. manufactured by Shin Nippon Koki Co., Ltd. 1 (trademark) is used.
[0023]
Although not shown, the assist gas supply source and the acceleration gas supply source can selectively supply a plurality of types of gases such as air (air), oxygen (O ₂ ), and nitrogen (N ₂ ). It is comprised, and it is comprised so that the gas suitable for the process of the workpiece 1 can be supplied. In this embodiment, as will be described later, the workpiece 1 is a stainless steel plate. Therefore, nitrogen gas (N ₂ ) is used as the assist gas, and oxygen (O ₂ ) is used as the acceleration gas.
[0024]
This laser processing apparatus is provided with an NC device 30, and is configured so that all operations related to the operation of the processing head 10, the supply of the assist gas and the spatter adhesion preventive agent, etc. are comprehensively controlled by this NC device 30. Has been. Further, this laser processing apparatus is provided with a gas control device 29, and the NC device 30 is used to switch assist gas and acceleration gas (switching types), gas flow rate, pressure, supply ON / OFF, and the like. It is configured to be performed via the gas control device 29.
[0025]
Next, the case where piercing of a stainless steel plate is performed will be described as an example with respect to the operational effects of the laser processing apparatus as described above.
[0026]
In the piercing process, first, the machining head 10 is positioned with respect to the machining position of the workpiece 1. At this stage, both the control valves 32 and 34 are closed, and neither the assist gas nor the spatter inhibitor is supplied. In the piercing process, the gap between the nozzle 16 and the workpiece 1 is set to be slightly wider than the gap in the cutting process.
[0027]
After the positioning of the head 10 is completed, the control valves 32 and 34 are opened, and the workpiece 1 is irradiated with the laser beam L to start piercing processing.
[0028]
When machining starts, piercing holes begin to be formed in the workpiece 1 by the laser beam L, while the control valve 32 is opened as described above, so that nitrogen gas compressed in a nitrogen gas supply source outside the figure assists. The gas is introduced into the space 20 at the center of the nozzle through the gas supply pipe 26. As a result, it is sprayed onto the workpiece 1 through the nozzle hole 20a, and as a result, the melt (sputter) generated along with the formation of the piercing hole is removed outside the hole by the assist gas (nitrogen gas).
[0029]
Further, when the control valve 34 is opened, oxygen is introduced into the outer space 22 through the main pipe 28a of the anti-spatter agent supply pipe 28, and the anti-sputter agent merges with oxygen in the main pipe 28a through the branch pipe 28b. To do. As a result, the spatter inhibitor together with oxygen is introduced into the outer space 22 and is sprayed onto the workpiece 1 through the nozzle hole 22a.
[0030]
When the anti-spattering agent is sprayed in this way, the anti-spattering agent is sprayed and applied to the workpiece 1 and its periphery, and spatters generated during processing are coated with the anti-sputtering agent. Then, the spraying action of the spatter inhibitor acts in addition to the spraying pressure of the assist gas, thereby promoting the action of removing the spatter. As a result, the adhesion of the spatter to the workpiece 1 is effectively prevented. . In particular, adhesion of scattered spatter to the workpiece 1 is effectively prevented by spraying the spatter preventing agent against spatter that is scattered. Further, the sprayed anti-spattering agent is applied directly or indirectly to the peripheral edges of the nozzle holes 20a and 22a by rebounding, thereby preventing the spatter from adhering to the nozzle 16.
[0031]
When the piercing hole is formed in this way (when the hole penetrates the workpiece 1), the irradiation of the laser beam L is stopped and the control valve 34 is closed. Then, the opening degree of the control valve 32 is set by the gas control device 29 so that the assist gas can be supplied under conditions suitable for cutting, and then the machining head 10 moves (moves up and down) and the nozzle 16 and the workpiece 1 are moved. The gap is readjusted to the gap at the time of cutting, and after the laser output is set to an output suitable for cutting, the cutting process is started.
[0032]
As described above, in the piercing processing by the laser processing apparatus, the spatter preventing agent is applied to the workpiece 1 by spraying the spatter preventing agent from the nozzle 16, and the spatter generated by the processing is coated with the spatter preventing agent. However, since the spatter is removed by the spray pressure of the assist gas and the spatter inhibitor, the spatter can be quickly removed from the workpiece 1. Therefore, it is possible to prevent the spatter from adhering to the workpiece 1 at a very high level as compared with the conventional method in which the anti-spatter agent is simply applied to the workpiece surface.
[0033]
In particular, in the laser processing apparatus described above, the nozzle 16 has a double structure having the spaces 20 and 22a inside and outside, so that the circular nozzle hole 22a is formed around the nozzle hole 20a that is the irradiation port of the laser beam L. With this configuration, the anti-spattering agent can be sprayed uniformly from the periphery of the piercing hole toward the hole portion, so that adhesion to the periphery of the piercing hole can be effectively prevented.
[0034]
And as a result of being able to prevent spatter adhesion well in this way, it becomes possible to maintain a good appearance of the sputter hole after processing and its peripheral part. Compared with the conventional method of simply applying the coating, product quality can be ensured better. In particular, in so-called copying control of the machining head 10 performed in the cutting process after piercing, it becomes difficult to be affected by sputtering, and the machining head 10 can be moved along the workpiece 1 smoothly and appropriately. A good cut surface can be obtained.
[0035]
The laser processing apparatus described above is an embodiment of the laser processing apparatus according to the present invention, that is, an example of a laser processing apparatus that can perform the laser processing method according to the present invention. The configuration can be appropriately changed without departing from the gist of the present invention. For example, the following aspects can also be adopted.
[0036]
(1) In the above embodiment, the circular nozzle hole 22a is formed around the nozzle hole 20a that is the irradiation port of the laser beam L, and the spatter preventing agent is sprayed from the nozzle hole 22a. A plurality of nozzle holes may be intermittently arranged around the nozzle hole 20a, and the spatter inhibitor may be ejected from these nozzle holes. In this case, there may be only one nozzle hole for injecting the spatter inhibitor.
[0037]
(2) Further, as shown in FIG. 2, a nozzle 40 may be separately provided in the vicinity of the nozzle hole 20 a of the nozzle 16, and a sputter inhibitor may be ejected from the nozzle 40. In this case, the nozzle 40 may be provided in the processing head 10, or may be provided separately from the processing head 10. The point is that any anti-spattering agent may be sprayed onto the part to be processed (piercing hole) of the workpiece 1 during the piercing process. As described above, according to the configuration in which the nozzle 40 dedicated to the anti-sputtering agent is provided separately from the nozzle 16 for laser irradiation, the spraying angle and the spraying distance of the anti-sputtering agent on the workpiece 1 can be adjusted independently. There are advantages.
[0038]
( ₃ ) In the present embodiment, the anti-sputtering agent is jetted from the nozzle 16 using oxygen (O ₂ ) as a medium by pumping oxygen (O ₂ ) and joining the anti-sputtering agent thereto. However, the medium gas is not necessarily oxygen (O ₂ ), and for example, air (air) or other gas can be substituted.
[0039]
(4) In this embodiment, since the stainless steel plate is used as the workpiece 1, nitrogen gas is used as an assist gas and oxygen is used as an accelerating gas for performing non-oxidation processing. Is made of a material other than stainless steel, oxygen is used as an assist gas to quickly process using the action of oxidation heat during processing, and an inert gas such as nitrogen gas is used as an accelerating gas. It may be used. In short, the types of the assist gas and the accelerating gas may be appropriately combined according to the material of the workpiece 1 so that the processing can be performed under optimum conditions.
[0040]
(5) By providing pressure control means such as an electropneumatic regulator in the middle of the spatter inhibitor supply pipe 28, the spout pressure of the spatter inhibitor sprayed from the nozzle 16 (nozzle 40 in the example of FIG. 2) can be adjusted. You may comprise. According to this, by changing the ejection pressure of the spatter inhibitor in accordance with the processing conditions such as the material of the workpiece 1, the output of the laser beam L, the type of assist gas, etc., the spatter adheres according to the processing conditions. The prevention effect can be exhibited better.
[0041]
In the embodiment, the case where the piercing process is performed has been described. However, according to the laser processing apparatus described above, the dross (melting) is performed in the cutting process by performing the cutting process while spraying the spatter inhibitor in the subsequent cutting process. Can also be obtained.
[0042]
【The invention's effect】
As described above, in the present invention, by performing the processing while spraying the anti-spattering agent toward the workpiece, not only the anti-sputtering agent is applied to the surface to be processed, but also the sputter itself generated by the processing is sputtered. As a result, the spatter removal action is accelerated by the spraying pressure of the assist gas or anti-sputtering agent, so that the conventional technique is simply applied to the surface to be processed. In comparison, it is possible to prevent the spatter from adhering to the workpiece at an extremely high level, and as a result, it is possible to ensure better product quality.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a laser processing apparatus according to the present invention.
FIG. 2 is a schematic configuration diagram showing another embodiment of the laser processing apparatus according to the present invention.
[Explanation of symbols]
L Laser beam 10 Head 14 Lens holder 16 Nozzle 20, 22 Space 20a, 22a Nozzle hole 26 Assist gas supply pipe 28 Anti-spatter supply pipe

Claims (5)

In a laser processing method in which processing is performed by irradiating a workpiece with laser light, processing is performed while spraying an anti-spattering agent that suppresses spatter adhesion to the workpiece onto the irradiated portion of the laser beam on the workpiece. A laser processing method characterized by the above. In a laser processing apparatus that has a nozzle for irradiating laser light and performs processing by irradiating the workpiece with laser light from this nozzle,
An anti-sputter agent supplying means capable of spraying an anti-spattering agent that suppresses the adhesion of spatter to the workpiece to the laser-irradiated portion of the workpiece, and spraying the anti-sputter agent to the workpiece during laser processing. And a control means for controlling the anti-spatter agent supply means. In the laser processing apparatus of Claim 2,
The anti-spatter agent supply means has a supply port provided integrally with the nozzle in the vicinity of the laser beam irradiation port of the nozzle, and the sputter agent is ejected from the supply port toward the workpiece. A featured laser processing apparatus. In the laser processing apparatus of Claim 3,
A laser processing apparatus comprising an annular supply port formed concentrically with the irradiation port on the outside of the irradiation port for laser light as the supply port. In the laser processing apparatus of Claim 2,
The laser processing apparatus, wherein the anti-sputtering agent supply means is disposed in the vicinity of the nozzle, has a dedicated nozzle separate from the nozzle, and ejects the anti-sputtering agent from the dedicated nozzle.

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