RU2624568C2 - Method of laser material processing (versions) - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: method includes the material direction focused lens of laser radiation with concurrent gas flow gas supply openings under the bottom surface of the lens and the nozzle area processing. Prior to focusing, the laser radiation is collimated. The gas flow is supplied to the central part of the lens or the protective glass placed under it by at least one series of focusing lens inclined to the optical axis and symmetrically located gas distribution holes. The central part of the lens or the protective glass placed under it, which is influenced by gas jets, is at least equal to the diameter of the laser radiation beam passing through them. Laser collimation telescope exercise through its negative and positive lens, floating along the optical axis.

EFFECT: increase the effectiveness of laser processing and machining quality by adjusting the laser power density in the treatment area, cooling and effective prevention of pollution and damage to the lens products and other small particles from the workpiece.

6 cl, 4 dwg

Description

The invention relates to the field of laser processing and can be used in various branches of engineering as for cutting sheet material and engraving, and heat hardening, surfacing and welding of metals.

A known method of laser processing of material, including the direction of the material focused by the lens of laser radiation and the simultaneous supply of a gas stream to the processing zone by means of a laser processing device [1].

The known method of laser processing of the material provides a gas stream to the nozzle nozzle by means of transverse gas distribution holes located at an angle creating a swirl-like funnel-like motion under the lens, and from it through the nozzle nozzle outlet to the treatment zone. Gas distribution holes create a vortex funnel-like gas flow in the nozzle nozzle, while the vortex gas flow does not provide effective protection of the lower surface of the lens from the evaporation products and other small particles from the treatment zone. Contaminants settle on the lower surface of the lens, mainly in its central part, through which the laser beam passes. As a result of this, the laser beam is partially absorbed by the microparticles of impurities deposited on the lower surface of the lens, while the lens heats up, and since the temperature coefficient of the refractive index has a positive sign, the focal length changes, the size of the laser beam in the processing zone increases, and the quality of processing deteriorates. To ensure high quality laser processing, it is necessary to periodically replace a contaminated lens with a new one, adjust the position of the lens relative to the optical axis, which leads to a decrease in efficiency, productivity and quality.

In addition, in the known method they do not collimate the laser beam, which makes it difficult to adjust the power density in the processing zone and thereby reduces the efficiency, productivity and quality of cutting.

There is also known a method of laser processing of material, including directing focused laser radiation onto the material and simultaneously supplying a gas stream to the processing zone by means of a laser processing device [2].

In the known method of laser processing of the material, the lens is protected from evaporation products and other small particles from the processing zone by a protective glass placed under it, thereby increasing the service life of the lens. The gas flow in the known method is directed into the cavity of the nozzle nozzle fitting. Such a flow supply does not fully protect the glass from evaporation products from the treatment zone. Contaminants settle on the surface of the protective glass, mainly in its central part. As a result of this, the laser beam is partially absorbed by the microparticles of contaminants deposited on the lower surface of the protective glass, which reduces the power of the laser beam and leads to the need to periodically replace the contaminated glass with a new one. In addition, in the known method also do not carry out collimation of the laser beam, which makes it difficult to adjust the power density in the processing zone. All of the above disadvantages reduce the efficiency, productivity and quality of cutting.

The technical task of this invention is to increase the efficiency of the laser processing process, productivity and processing quality.

The technical result achieved by the claimed method of laser processing of the material is:

- in providing, according to the first embodiment, more effective protection of the lens, and according to the second embodiment, placed under the protective glass lens, from evaporation products from the treated surface of the material;

- to reduce the energy loss of laser radiation, according to the first embodiment, on the surface of the lens, and in the second embodiment, placed under the lens of a protective glass;

- in increasing, according to two variants of the method, productivity and quality of processing.

According to the first embodiment, the claimed technical result is achieved by the fact that in the known method of laser processing of material, including directing focused laser radiation to the material and simultaneously supplying a gas stream to the processing zone by means of a laser processing device, according to the invention, a laser processing device consisting of a focusing lens is used located in the housing, a nozzle nozzle connected to the housing and a sleeve housed in it, in which symmetrically arranged gas distribution holes tilted to the optical axis of the focusing lens, while the laser radiation is collimated before focusing, and during processing, a gas stream is supplied from at least equal to the diameter of the laser beam passing through it to the center part of it, at least equal to the diameter of the laser beam passing through it one row of said gas distribution openings.

In addition, for the collimation of laser radiation using a telescope and carry it through a negative lens and a positive lens, which is moved along its optical axis.

In addition, the gas distribution holes have a diameter of 1.0 to 2.0 mm.

According to the second embodiment, the claimed technical result is achieved by the fact that in the known method of laser processing of material, including directing focused laser radiation onto the material and simultaneously supplying a gas stream to the processing zone by means of a laser processing device, according to the invention, a laser processing device consisting of a focusing lens is used located in the housing, a protective glass placed under the lens, a nozzle nozzle connected to the housing, and a sleeve housed in it, into the cat Gas distribution holes are symmetrically located and inclined to the optical axis of the focusing lens, while the laser radiation is collimated before focusing, and during processing, a gas stream from the laser is transmitted to the central part of the protective glass, at least equal to the diameter of the laser beam passing through it at least one row of said gas distribution openings.

In addition, for the collimation of laser radiation using a telescope and carry it through a negative lens and a positive lens, which is moved along its optical axis.

In addition, the gas distribution holes have a diameter of 1.0 to 2.0 mm.

The essence of the proposed method of laser processing of materials is as follows.

According to the first embodiment, for the implementation of the method, a laser processing device is used, consisting of a focusing lens located in the housing, a nozzle nozzle connected to the housing, and a sleeve housed in it, in which gas distribution openings are symmetrically arranged and inclined to the optical axis of the focusing lens.

According to the second embodiment, a laser processing device is used to implement the method, consisting of a focusing lens located in the housing, a protective glass placed under the lens, a nozzle nozzle connected to the housing, and a sleeve housed in it, in which are symmetrically arranged and inclined to the optical axis of the focusing lens gas distribution holes.

The implementation of the device for laser processing in two ways allows it to work for a long time without interruption to replace or clean the lens or protective glass.

Before focusing, laser radiation is collimated according to two variants of the method, which allows, depending on the type of processing and the material being processed, to adjust the power density in the processing zone and, thereby, increases efficiency, productivity and quality.

During processing, according to the first embodiment, under the lower surface of the lens, and according to the second variant, a gas stream is supplied symmetrically located and inclined to the optical axis to the central part of the protective glass placed under the lens, at least equal to the diameter of the laser beam passing through it respectively a focusing lens or a gas distribution aperture located under the lens of the protective glass, increases efficiency, productivity and quality.

Gas distribution holes, in two variants of the method, are performed with a diameter of 1.0 to 2.0 mm, which increases the pressure head, and thereby more efficiently cleans the lens or protective glass from evaporation products from the treatment zone, and thereby improves productivity and quality processing.

A comparison of the proposed technical solution with the prototype shows that the method of laser processing of the material differs from the prototype with new significant features.

According to the first option:

- use a device for laser processing, consisting of a focusing lens located in the housing, a nozzle nozzle connected to the housing, and placed in it a sleeve in which gas distribution holes are symmetrically arranged and inclined to the optical axis of the focusing lens;

- before focusing, the laser radiation is collimated;

- during processing, under the lower surface of the lens, a gas stream from at least one of the aforementioned gas distribution openings is supplied to its central part, at least equal to the diameter of the laser beam passing through it,

According to the second option:

- use a device for laser processing, consisting of a focusing lens located in the housing, a protective glass placed under the lens, a nozzle nozzle connected to the housing, and a sleeve housed in it, in which gas distribution holes are symmetrically arranged and inclined to the optical axis of the focusing lens ;

- before focusing, the laser radiation is collimated;

- during processing, a gas stream from at least one row of said gas distribution openings is supplied to the central part of the protective glass at least equal to the diameter of the laser beam passing through it.

A comparison of the claimed technical solution with the known from the prior art shows that the distinguishing features of the claimed, in two variants, the method does not follow from the prior art.

Therefore, the claimed technical solution meets the criteria of patentability "novelty" and "inventive step".

The stated essence of the claimed invention is illustrated by the following graphic materials on which are presented:

FIG. 1 is a general view of a device for implementing the proposed method for laser processing of material, according to the first embodiment, when gas is supplied under the lens;

FIG. 2 is a general view of a device for implementing the proposed method for laser processing of material, according to the second embodiment, when gas is supplied under a protective glass;

FIG. 3 - shows a picture of the effect of gas jets on the central part of the lens or a protective glass placed under the lens according to the prototype;

FIG. 4 - shows the effect of gas jets, according to the first embodiment, on the central part of the lens or on the protective glass placed under the lens according to the invention.

To implement the method of laser processing of material, according to two variants of its implementation, use is made of a device containing a laser 1, a telescope 2, including a negative lens 3 and a positive lens 4, moved along its optical axis, mounted in a fixed housing 5, a rotary mirror 6, the center of which is located on the optical axis of the laser 1.

According to the first embodiment of the method (Fig. 1), the focusing lens 7 is placed in the cylindrical body 8, the nozzle nozzle 9 is connected to the cylindrical body 8 by a threaded connection.

The nozzle nozzle 9 according to two variants of the method is made with a cylindrical step hole and is provided with a sleeve 10 located in its step hole, made with an inner surface or in the form of a cone or cylinder turning into a cone. At least one row of focusing lenses 7 inclined to the optical axis and symmetrically positioned gas distribution holes 11 is made in the sleeve 10. According to the first embodiment, the axis of the gas distribution holes 11 are directed to the central part of the focusing lens 7. The central part of the focusing lens 7, which is affected by jets gas, at least equal to the diameter of the laser beam passing through it. The gas stream is supplied by gas distribution holes 11 with a diameter of 1.0 to 2.0 mm. The number of symmetrically arranged gas distribution holes 11 in each row is at least two. The sleeve 10 is made with an annular groove forming with the inner cylinder surface of the nozzle 9 and a cavity 13 for connecting the gas through the holes 11 of the sleeve 10 connected to the nozzle 12 for supplying process gas.

According to the second embodiment of the method (FIG. 2), the focusing lens 7 is provided with a protective glass 14 made under the lens made of quartz glass and installed in a known manner in a cylindrical body 8 under the focusing lens 7.

According to the second embodiment of the method, the axis of the gas distribution holes 11 are directed to the central part of the protective glass, 14, equal to at least the diameter of the laser beam passing through them. At the output end of the sleeve 10 can be placed a removable tip 15 made with a conical nozzle, while the diameters of the inner conical surface of the sleeve 10 and the removable tip 15 in the mating zone are the same. The processed material is indicated by the number 16.

A device for implementing the method of laser processing of material, according to two variants of its implementation, works as follows.

The processed material 16 is installed on the desktop. The laser beam is directed to a collimator 2 made in the form of a two-lens telescope 2, and the laser beam is collimated, i.e. its transformation into a parallel beam, through its negative lens 3 and positive lens 4, moved along its optical axis. Then, in the first embodiment (Fig. 1), through the focusing lens 7 and the protective glass 14 placed underneath, through the swivel mirror 6, the focusing lens 7, and focused on the surface of the processed material 16 At the same time, through the nozzle 12, the process gas is supplied to the cavity 13 of the nozzle nozzle 9 and then at least one row of gas jets, inclined to the optical axis of the focusing lens 7 and symmetrically located gas distribution holes 11, is directed, according to the first embodiment, to the central part of the lens 7, and according to the second embodiment, to the central part of the protective glass 14, at least equal to the diameter of the laser radiation passing through it. In this case, the process gas, for example compressed air, receives acceleration in the gas distribution openings 11, made with a diameter of 1.0 to 2.0 mm, and with all the kinetic energy of the gas streams flowing out of them protects the central part of the lens 7 or underneath the protective glass 14. The material 16 is moved and, according to the specified program, the material is processed 16. At the end of the processing program, the laser radiation and the process gas are turned off.

Computer simulation of the gas flow and the effects of gas jets on the lens (Fig. 3) shows a picture of the swirling movement of the gas stream under the focusing lens 7 or protective glass 14 of the prototype. With such a funnel-like movement of the gas stream, the central lower part of the lens 7 or the protective glass 14 is not fully protected, i.e. zone of passage of the laser beam. As a result of this, the laser beam is partially absorbed by the microparticles of impurities deposited, in the first embodiment, in the central part of the lens 7, and in the second embodiment, protective glass 14, which leads to a decrease in efficiency, productivity and quality of processing.

According to the invention (Fig. 4), the effect, according to the first embodiment, on the central part of the lens 7, and on the second option, on the central part of the protective glass 14 located under the lens, of the whole kinetic energy of the gas jets flowing from the focusing lens tilted to the optical axis gas distribution holes 11, made with a diameter of from 1.0 to 2.0 mm, increases the pressure head, and thereby more effectively protects the lens 7 or the protective glass 14 from the products of evaporation from the treatment area, and thereby leads to an increase in linen and quality of processing.

Testing the manufactured prototype of a device for laser processing of material when using solid-state laser on an A&T crystal: Nd + 3 pulsed-periodic action of cutting, engraving and surfacing technologies with the same quantitative batches of parts, with the same laser radiation power and the same for each of the above technologies , the gas pressure at the inlet to the device confirmed the results of computer simulation of the prototype (Fig. 3) and according to the invention (Fig. 4).

As a result of the fact that on the lens 7 or a protective glass 14 located under it, gas jets flowing from the gas distribution holes 11 onto the central part of the lens 7 or a protective glass 14 located under the lens 7 are better protected from pollution by evaporation products and other small particles from the treatment zone .

Tests have shown that the service life of a lens or a protective glass placed under it, when performing various types of processing according to two variants of the proposed method, has increased at least two times and thereby increased the efficiency of the laser processing process, productivity and quality of processing.

The claimed technical solution is suitable for industrial implementation using existing production technology.

Thus, the claimed technical solution meets the condition of "industrial applicability".

Information sources

1. RF patent No. 2143964, IPC ⁵ V23K 23/14, publ. 01/10/2000.

2. RF patent No. 2127179, IPC6 V23K 23/14, publ. March 10, 1999.

Claims (6)

1. A method of laser processing of material, including directing focused laser radiation onto the material and simultaneously supplying a gas stream to the processing zone by means of a laser processing device, characterized in that a laser processing device is used, consisting of a focusing lens located in the housing, a nozzle nozzle, connected to the housing, and a sleeve housed in it, in which gas distribution holes are symmetrically arranged and inclined to the optical axis of the focusing lens, and this, before focusing, the laser radiation is collimated, and during processing, under the lower surface of the lens, a gas stream from at least one of the aforementioned gas distribution holes is introduced into its central part, at least equal to the diameter of the laser beam passing through it. 2. The method according to p. 1, characterized in that a telescope is used to collimate the laser radiation and is carried out through a negative lens and a positive lens, which is moved along its optical axis. 3. The method according to p. 1, characterized in that the gas distribution holes perform a diameter of from 1.0 to 2.0 mm 4. A method of laser processing of material, including directing focused laser radiation to the material and simultaneously supplying a gas stream to the processing zone by means of a laser processing device, characterized in that a laser processing device is used, consisting of a focusing lens located in the housing, a protective glass, placed under the lens nozzle nozzle connected to the housing, and placed in her sleeve, which are made symmetrically located and inclined to the optical axis of the focusing the lenses are gas distribution holes, while the laser radiation is collimated before focusing, and during processing, a gas stream from at least one row of the said gas distribution holes is supplied to the central part of the protective glass at least equal to the diameter of the laser beam passing through it. 5. The method according to p. 4, characterized in that for the collimation of laser radiation using a telescope and carry it through a negative lens and a positive lens, which is moved along its optical axis. 6. The method according to p. 4, characterized in that the gas distribution holes perform a diameter of from 1.0 to 2.0 mm

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