JPH06262384A - Laser beam machine - Google Patents

Abstract

PURPOSE:To provide a laser beam machine unnecessitating the rotary operation of an object to be worked or a converging mirror, and possible to easily realize the reforming, of an surface on the circumference of an object to be worked. CONSTITUTION:A laser beam machining is performed by reflecting and converging a laser beam 1 to make it incident to objects 6 and 16 to be worked. A ring-shaped laser beam 2 whose intensity distribution in a section perpendicular to the proceeding direction of the laser beam, is a ring-shape, is reflected and converged by converging mirrors 5 and 15. A laser beam machining is performed by inserting a columnar object 6 to be worked into an opening part 5a in the center part of the converging mirror 5 or arranging a cylindrical object 16 to be worked on the outer periphery part of the converging mirror 15. Typically, the normal laser beam 1 is deformed to a ring-shaped laser beam 2 by using a beam-deforming mirror 4. For the beam-deforming mirror 4, for instance, a mirror equipped with the reflection part 4a of a conical outer surface in the center part, and equipped with the reflection part 4b of a conical inner surface on its outer periphery part, is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for processing by a laser beam, and more particularly to a laser processing apparatus for performing surface modification processing on a circumference.

[0002]

2. Description of the Related Art With the remarkable progress of laser technology in recent years,
In the field of laser processing technology, various types of laser processing devices have been proposed and put into practical use. FIG. 4 is a schematic diagram showing an example of a laser processing apparatus for performing surface modification processing such as quenching and surface peeling among such laser processing apparatuses. FIG. 4 shows an arrangement configuration in which the laser beam 1 is incident on the cylindrical workpiece 6 to be quenched (quenched portion 7), and the processing gas ejection device 10 and the condenser mirror 11 are shown. A laser processing device is constituted by and. The processing gas jetting device 10 is a device for jetting an inert gas, dry air, or other processing assist gas to blow it onto the workpiece 6 or its periphery, and the condenser mirror 11 is a spherical surface or a parabolic surface. The device has a reflecting surface, and the laser beam 1 is reflected and condensed by the reflecting surface to be incident on the workpiece 6.

That is, when quenching the tip of a cylindrical work piece 6 as shown in FIG. 4, a laser beam 1 emitted from a laser oscillator (not shown) is arbitrarily focused on a condenser mirror 11. The workpiece 6 is arranged such that the workpiece 6 is positioned at an arbitrary spot diameter of the laser beam 1 while being incident at an incident angle and reflected and condensed. In this case, the arbitrary spot diameter of the laser beam 1 for disposing the workpiece 6 is determined according to the intensity of the laser beam 1 and the processing quality to be obtained. Then, in such an arrangement state, according to the processing range of the workpiece 6,
The laser beam 1 is incident while rotating the workpiece 6 or moving the workpiece 6 in the axial direction. Further, if necessary, an inert gas such as helium or argon or dry air, or another assist gas for processing is ejected by the machining gas ejecting device 10 and blown onto the workpiece 6 or its periphery. By spraying the inert gas or the dry air in this way, it is possible to suppress the generation of plasma and prevent the spatter from adhering to the mirror surface.

Further, FIG. 5 shows an arrangement configuration in which the laser beam 1 is incident on the inner surface of a cylindrical workpiece 16 for quenching. That is, when quenching the inner surface of the cylindrical workpiece 16 as shown in FIG. 5, the laser beam 1 emitted from a laser oscillator (not shown)
Is incident on the condenser mirror 11 at an arbitrary incident angle and is reflected and condensed so that the workpiece 16 is positioned at a position of an arbitrary spot diameter of the laser beam 1 so that the workpiece 16 is Deploy. In this case, the arbitrary spot diameter of the laser beam 1 for disposing the workpiece 16 is determined according to the intensity of the laser beam 1 and the processing quality to be obtained. Then, in such an arrangement state, the laser beam 1 is incident while the workpiece 16 or the condenser mirror 11 is rotated or moved in the axial direction.

[0005]

However, the conventional laser processing apparatus as described above has the following problems. That is, the laser processing apparatus shown in FIGS. 4 and 5 has a configuration in which the laser beam 1 condensed by the condensing mirror 11 is directly incident on the workpieces 6 and 16, so that a pipe, an engine piston and a cylinder, etc. When processing the cylindrical or cylindrical workpieces 6 and 16 that require surface modification processing on the circumference, it is necessary to rotate the workpieces 6 and 16 or the condenser mirror 11. Therefore, the workpieces 6 and 16 or the condenser mirror 1
A device for rotating 1 has to be separately arranged, and a matching work between the devices is newly required.
There is a problem in practical use.

Further, when the laser beam 1 is incident while rotating the workpieces 6 and 16 or the condenser mirror 11 as described above, the initial incident region of the laser beam 1 on the workpieces 6 and 16 becomes An overlap portion is formed between the incident area after one rotation. Since the overlapping portion of the incidence of the laser beam 1 is a locally overheated portion in comparison with the other portions on the circumference of the workpieces 6 and 16, the processing on the circumference of the workpieces 6 and 16 is It will make a difference in quality. Therefore, with such a conventional laser processing apparatus, it is difficult to realize the uniform surface modification usually required in the surface modification processing on the circumference of the workpieces 6 and 16.

The present invention has been proposed in order to solve the problems of the prior art as described above, and an object of the present invention is not to rotate a work piece or a condensing mirror and to work the work piece. It is an object of the present invention to provide a laser processing apparatus capable of easily realizing uniform surface modification on the circumference.

[0008]

A laser processing apparatus according to the present invention is a laser processing apparatus for reflecting and condensing a laser beam and making it incident on a workpiece for laser processing, in a cross section orthogonal to the traveling direction of the laser beam. Is provided with a condenser mirror for reflecting and condensing a ring-shaped laser beam having a ring-shaped intensity distribution.

First, a laser processing apparatus for a cylindrical workpiece is characterized in that the condensing mirror has an opening for inserting the workpiece in the center thereof.
In this case, it is desirable that the processing assist gas is provided on the rear surface side of the opening of the condenser mirror, and the processing assist gas is ejected and introduced to the reflection surface side of the condenser mirror through the opening of the condenser mirror. A processing gas ejection device and an exhaust device which is provided in the vicinity of the converging point of the condensing mirror and exhausts the processing point atmosphere gas at the time of processing from the outer periphery of the workpiece are further provided. More preferably, it further comprises a beam absorber provided near the focusing point of the focusing mirror and absorbing the laser beam.

Next, the laser processing apparatus for a cylindrical workpiece is characterized in that the converging mirror has a condensing point outside the outer peripheral end in the radial direction. In this case, the condenser mirror is configured to intersect the reflected and condensed ring-shaped laser beam on its central axis, and the opening provided at the center thereof and insertable into this opening. A condenser diameter conversion mirror, and when the condenser diameter conversion mirror is inserted in the opening, the condenser laser reflects the ring-shaped laser beam reflected and condensed by the condenser mirror, It can also be configured to convert.

Further, the laser processing apparatus of the present invention is typically provided on the entrance side of the converging mirror regardless of the shape of the object to be processed, and makes a laser beam enter to form the ring-shaped laser beam. The apparatus further includes a beam deforming mirror that deforms. As such a beam deforming mirror, specifically, it has a conical outer surface reflecting portion for reflecting the laser beam in a circular shape in the outer peripheral direction in the central portion thereof, and the conical outer surface reflecting portion. It is possible to use a beam deforming mirror that has a conical inner surface reflection portion that further reflects the laser beam reflected by the conical outer surface reflection portion to form the ring-shaped laser beam on the outer peripheral portion of.

In a typical embodiment of the present invention, there is an opening for penetrating a laser beam, which is provided on the incident side of the condenser mirror, and reflects the ring-shaped laser beam around this opening. A beam guide mirror is further provided, and the beam guide mirror, the condenser mirror, and the beam deforming mirror cause a laser beam penetrating an opening of the beam guide mirror to enter the beam deforming mirror and deform the ring laser beam. Then, the ring-shaped laser beam is arranged so as to be reflected around the opening of the beam guide mirror and incident on the condenser mirror.

[0013]

In the laser processing apparatus of the present invention having the above-mentioned structure, the hollow portion which propagates the ring-shaped laser beam in the direction opposite to the propagation direction by the condenser mirror and has no light intensity distribution. It is possible to form a disc-shaped or conical laser beam by focusing and reflecting so that the diameter of the laser beam is reduced or expanded.

First, for a cylindrical work piece, the cylindrical work piece is inserted into an opening provided in the central portion of the condenser mirror, and a hollow portion having no light intensity distribution is formed by the condenser mirror. By reflecting and condensing so as to reduce the diameter of the laser beam, the disc-shaped or conical laser beam that is reflected and condensed can be uniformly incident on the circumference of the surface of the cylindrical workpiece. . If a processing gas jetting device is provided on the back side of the light collecting mirror and an exhaust device is provided near the light collecting point of the light collecting mirror, the processing gas jetting device uses the opening of the light collecting mirror to make the processing point. The processing assist gas can be supplied to the vicinity, and the processing point atmosphere can be exhausted from the outer periphery of the workpiece by the exhaust device without blocking the optical path of the laser beam reflected and condensed from the condenser mirror. Further, when the beam absorber is provided in the vicinity of the converging point of the condenser mirror, the laser beam reflected from the workpiece can be extinguished by the beam absorber.

Next, for a cylindrical workpiece, a condenser mirror is inserted into the hollow portion of the cylindrical workpiece, and the diameter of the hollow portion having no light intensity distribution is enlarged by the condenser mirror. By reflecting and condensing in this manner, the disc-shaped or conical laser beam that is reflected and condensed can be uniformly incident on the inner surface of the cylindrical workpiece on the circumference. Further, when an opening is provided at the center of the condenser mirror and the condenser diameter conversion mirror can be inserted into this opening, the condenser diameter conversion mirror is moved while the workpiece or the condenser mirror is being moved. By inserting or removing, it is possible to continuously change the quality of the surface modification without causing overlap of the incident area on the processing incident surface of the workpiece.

On the other hand, when the beam deforming mirror is used, an ordinary laser beam can be easily deformed into a ring-shaped laser beam by the beam deforming mirror. Furthermore, by combining the beam deforming mirror and the beam guide mirror, the ring-shaped laser beam can be suitably incident on the focusing mirror with a simple arrangement.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a laser processing apparatus according to the present invention will be described below with reference to FIGS. Here, FIGS. 1 to 3 are schematic views showing a laser processing apparatus for performing surface modification processing such as quenching and surface peeling.
The same parts as those in the conventional technique shown in FIGS. 4 and 5 are designated by the same reference numerals, and the description thereof will be omitted.

(1) First Embodiment FIG. 1 FIG. 1 shows a typical embodiment in which the present invention is applied to a laser processing apparatus for a cylindrical workpiece (first embodiment). ) Is a schematic diagram showing the first embodiment, and the first embodiment includes the configurations of the inventions of claims 1 to 4 and claims 7 to 9. In FIG. 1, reference numeral 2 is a ring-shaped laser beam having a ring-shaped intensity distribution in a cross section orthogonal to the traveling direction of the laser beam. Further, 3 is a beam guide mirror, 4 is a beam deforming mirror, and 5 is a condenser mirror having a reflecting surface on one side of a flat plate-shaped material. The beam guide mirror 3 has an opening 3a through which the laser beam 1 penetrates, and is configured to reflect the ring-shaped laser beam 2 around the opening 3a. The beam deforming mirror 4 has a conical outer surface-reflecting portion 4a that reflects the laser beam 1 in a circular shape in the outer peripheral direction at the center thereof.
Further, on the outer peripheral portion of the conical outer surface reflection portion 4a, there is provided a conical inner surface reflection portion 4b which further reflects the laser beam reflected by the conical outer surface reflection portion 4a to form the ring-shaped laser beam 2. . The condensing mirror 5 has a reflecting surface such as a spherical surface or a parabolic surface for reflecting and condensing the ring-shaped laser beam 2 on one flat surface of a flat plate-shaped material, and an opening for inserting the workpiece 6 at the center thereof. 5a.

Then, these beam guide mirrors 3,
The beam transforming mirror 4 and the condenser mirror 5 are arranged in a shape as shown in FIG. First, the beam guide mirror 3
Are arranged so that the surface (back surface) opposite to the reflection surface of the laser beam 1 faces. More specifically,
The beam guide mirror 3 is arranged so that the optical axis of the laser beam 1 and the center of the opening 3a thereof coincide with each other, and
It is arranged to have an angle of 45 degrees with respect to the optical axis of the laser beam 1. Next, the beam deforming mirror 4 is arranged along the optical axis of the laser beam 1 on the traveling direction side of the beam guide mirror 3 with its reflection surface facing the reflection surface of the beam guide mirror 3. . More specifically, the beam deformation mirror 4 makes the optical axis of the laser beam 1 and the center of the conical outer surface 4a thereof coincide with each other and forms an angle of 90 degrees with respect to the optical axis of the laser beam 1. Are arranged to have. Furthermore, the collecting mirror 5
Is arranged such that its reflection surface faces the reflection surface of the beam guide mirror 3 and forms an angle of 90 degrees with the beam deformation mirror 4 with respect to this beam guide mirror 3. More specifically, the condensing mirror 5 includes a ring-shaped laser beam 2 reflected by the beam deforming mirror 4.
Is arranged such that its condensing point is located on the optical axis of and the optical axis of the ring-shaped laser beam 2 has an angle of 90 degrees.

The above arrangement relationship can be rephrased as follows. That is, the beam guide mirror 3, the beam deforming mirror 4, and the condensing mirror 5 make the laser beam 1 penetrating the opening of the beam guide mirror 3 incident on the beam deforming mirror 4 and ring laser beam 2.
The ring-shaped laser beam 2 is arranged so as to be reflected by the periphery of the opening 3a of the beam guide mirror 3 and enter the condenser mirror 5.

Further, 8 is an exhaust device, and 9 is a beam absorber. The exhaust device 8 is provided in the vicinity of the converging point of the condensing mirror 5, and is a device for exhausting the processing point atmosphere gas during processing from the outer periphery of the workpiece 6. The beam absorber 9 is disposed near the light collecting point of the light collecting mirror 5 and the light collecting mirror 5 and the exhaust device 8.
It is arranged to be located between and. The processing gas ejection device 10 is arranged on the back side of the opening 5a of the condenser mirror 5 so that the processing assist gas can be introduced to the reflection surface side of the condenser mirror 5 through the opening 5a. Is configured.

The operation of the laser processing apparatus of this embodiment having the above construction is as follows. First, when quenching the tip of a cylindrical workpiece 6 as shown in FIG. 1, a laser beam 1 emitted from a laser oscillator (not shown) is incident from the back side of the beam guide mirror 3. , Penetrates through the opening 3 a and enters the center of the beam deforming mirror 4. In this case, the laser beam 1 is first reflected by the conical outer surface reflection portion 4a of the beam deformation mirror 4 in a circular shape in the outer peripheral direction, and then by the conical inner surface reflection portion 4b of the outer peripheral portion. It is reflected and transformed into the ring-shaped laser beam 2. The ring-shaped laser beam 2 is formed coaxially with the laser beam 1 and propagates in the direction opposite to the laser beam 1.

The ring-shaped laser beam 2 thus formed passes through the outer periphery of the laser beam 1, is reflected around the opening 3a of the beam guide mirror 3, and is incident on the condenser mirror 5. In this case, the ring-shaped laser beam 2
Is propagated in the direction opposite to the propagation direction by the condenser mirror 5 and is reflected and condensed so that the diameter of the hollow portion having no light intensity distribution is reduced. As a result, as shown in FIG. 1, a disc-shaped or conical laser beam is formed toward the radial center side of the condenser mirror 5.

Therefore, the workpiece 6 is placed in the hollow portion having no light intensity distribution of the ring-shaped laser beam 2 in the above focusing process from the rear surface of the focusing mirror 5 through the opening 5a thereof. By inserting, a disc-shaped or conical laser beam can be uniformly incident on the circumference of the surface of the workpiece 6. Therefore, unlike the conventional laser processing apparatus shown in FIG. 4, it is not necessary to rotate the workpiece 6 and it is possible to easily realize uniform surface modification on the circumference of the workpiece 6. Furthermore, by moving the workpiece 6 or the condenser mirror 5 only in the axial direction, it is possible to easily realize uniform surface modification over the entire surface of an arbitrary processing range.

Further, in this embodiment, the condenser mirror 5
Using the processing gas ejection device 10 through the opening 5a of
A processing assist gas can be supplied to the periphery of the workpiece 6. Further, the processing point atmosphere can be exhausted from the outer periphery of the workpiece 6 by the exhaust device 8 without obstructing the optical path of the processing laser beam reflected and condensed from the condenser mirror 5.

On the other hand, in this embodiment, the condenser mirror 5
Since the beam absorber 9 is provided in the vicinity of the condensing point of the laser beam, the laser beam reflected from the workpiece 6 is absorbed by the beam absorber 9.
It can be erased by using and is excellent in safety.
For example, in the present embodiment, as described above, it is assumed that the workpiece 6 is subjected to surface modification such as quenching. However, the laser processing apparatus of FIG. A coated conductive wire having a conductor such as copper in the center is used as the object 6, and it can be used as a laser processing device for peeling the coating of the coated conductive wire. In this case,
The laser beam reflected by the central conductor exposed during the coating removal can be extinguished by the beam absorber 9.

(2) Second Embodiment FIG. 2 FIG. 2 is a typical embodiment (second embodiment) in which the present invention is applied to a laser processing apparatus especially for a cylindrical workpiece. ) Is a schematic diagram showing the present invention, and the second embodiment includes the configurations of the inventions of claims 5 and 7 to 9. As shown in FIG. 2, in this embodiment, a condenser mirror 15 having a shape different from that of the first embodiment is used according to the difference in shape of the target workpiece 16.
That is, the condenser mirror 15 of the present embodiment has a circumferential reflection surface such as a spherical surface or a parabolic surface for reflecting and condensing the ring-shaped laser beam 2 on the side surface of the cylindrical material. The condenser mirror 15 is arranged so as to have an angle of 90 degrees with respect to the optical axis of the ring-shaped laser beam 2 reflected by the beam deforming mirror 4, and the outer circumference of the condenser mirror 15 in the radial direction. It has a condensing point outside the end.

Also, in this embodiment, the guide mirror 3
The shape and arrangement of the beam deforming mirror 4 are exactly the same as those in the first embodiment. That is, also in this embodiment, as in the first embodiment, the beam guide mirror 3, the beam deformation mirror 4, and the condenser mirror 1 are provided.
Reference numeral 5 denotes a laser beam 1 penetrating the opening portion of the beam guide mirror 3 and incident on a beam deformation mirror 4 to be transformed into a ring-shaped laser beam 2, and this ring-shaped laser beam 2 surrounds the opening portion 3 a of the beam guide mirror 3. It is arranged so as to be reflected by and enter the condenser mirror 15. In addition, in the present embodiment, the exhaust device 8, the beam absorber 9, and the processing gas jetting device 10 which are provided in the first embodiment are omitted.

The operation of the laser processing apparatus of this embodiment having the above structure is as follows. First, when quenching the inner surface of a cylindrical work piece 16 as shown in FIG. 2, the laser beam 1 emitted from a laser oscillator (not shown) is incident from the back side of the beam guide mirror 3. , Penetrates through the opening 3 a and enters the center of the beam deforming mirror 4. In this case, the laser beam 1 is first reflected by the conical outer surface reflection portion 4a of the beam deformation mirror 4 in a circular shape in the outer peripheral direction, and then by the conical inner surface reflection portion 4b of the outer peripheral portion. It is reflected and transformed into the ring-shaped laser beam 2. The ring-shaped laser beam 2 is formed coaxially with the laser beam 1 and propagates in the direction opposite to the laser beam 1.

The ring-shaped laser beam 2 thus formed passes through the outer periphery of the laser beam 1, is reflected around the opening 3a of the beam guide mirror 3, and is incident on the condenser mirror 15. In this case, the ring-shaped laser beam 2
Is propagated in the direction opposite to the propagation direction by the condenser mirror 15, and is reflected and condensed so that the diameter of the hollow portion having no light intensity distribution is enlarged. As a result, as shown in FIG. 2, a disk-shaped or conical laser beam is formed toward the radially outer side of the condenser mirror 15.

Therefore, by inserting the condensing mirror 15 into the hollow portion of the cylindrical workpiece 16, the disc-shaped or conical laser beam is circularly applied to the inner surface of the cylindrical workpiece 16. It can be uniformly incident on the circumference. Therefore, unlike the conventional laser processing apparatus shown in FIG. 5, it is not necessary to rotate the workpiece 16 or the condenser mirror 15, and it is possible to easily perform uniform surface modification on the circumference of the workpiece 16. Can be realized, further, the workpiece 1
6 or by moving the condenser mirror 15 only in the axial direction, uniform surface modification can be easily realized over the entire surface of an arbitrary processing range.

(3) Third Embodiment FIG. 3 FIG. 3 shows an embodiment in which the present invention is applied to a laser processing apparatus for a cylindrical workpiece, as in the second embodiment. It is a schematic diagram showing an example (third embodiment).
The embodiment includes the configurations of the inventions of claims 5 to 9. As shown in FIG. 3, in this embodiment, the target workpiece 16 has the same shape as that of the second embodiment, but the configuration of the condenser mirror 25 is different from that of the second embodiment. That is, the condensing mirror 25 of the present embodiment has a circular reflecting surface such as a spherical surface or a parabolic surface for reflecting and condensing the ring-shaped laser beam 2 on one surface of the flat plate-shaped material, and It is arranged so as to have an angle of 90 degrees with respect to the optical axis of the reflected ring-shaped laser beam 2. The condensing mirror 25 has a condensing point outside the outer peripheral end portion in the radial direction of the condensing mirror 25, and in particular, the ring-shaped laser beam 2 reflected and condensed is made to intersect on the central axis thereof. It is configured. Also, this condensing mirror 2
5 has an opening 25a in the center thereof, and the condenser diameter conversion mirror 21 can be inserted into the opening 25a. The condensing diameter conversion mirror 21 is configured to reflect the ring-shaped laser beam 2 reflected and condensed by the condensing mirror 25 on the side surface of the cylindrical material to convert the condensing diameter.

In the laser processing apparatus of this embodiment having the above-mentioned structure, the following operational effects can be obtained. That is, by inserting or removing the condensing diameter conversion mirror 21 during the movement of the workpiece 16 or the condenser mirror 25, it is possible to continuously generate the incident areas on the machining incident surface of the workpiece 16 without overlapping portions. It is possible to change the quality of surface modification. Therefore, the practicability of the laser processing device can be further improved.

Needless to say, in this embodiment, if the converging diameter conversion mirror 21 is not used, the same effect as that of the second embodiment can be obtained. That is, it is possible to easily realize uniform surface modification on the circumference of the workpiece 16, and further, by moving the workpiece 16 or the condenser mirror 25 only in the axial direction, the entire surface of an arbitrary processing range. Thus, uniform surface modification can be easily achieved.

(4) Other Embodiments Note that the present invention is not limited to the above embodiments, and the specific configuration of the beam deforming mirror can be changed as appropriate, for example, two or more separate mirrors. It is also possible to form a beam deforming mirror by combining mirrors. Also,
The optical path of the ring-shaped laser beam can be freely designed,
It is possible to freely configure the number of mirrors used in each part, the shape and arrangement of each, according to the optical path design. In addition to the above, a person skilled in the art of the present invention can consider various modifications, and all of these modifications are included in the scope of the claims of the present invention. .

[0036]

As described above, according to the present invention, a condensing mirror is used to reflect and condense a ring-shaped laser beam, and a cylindrical workpiece is inserted into the opening of the condensing mirror. Alternatively, by arranging a cylindrical work piece on the outer periphery of the condensing mirror to perform laser processing, it is not necessary to rotate the work piece or the condensing mirror, and the circle of the work piece is not required. It is possible to provide a laser processing apparatus that can easily achieve uniform surface modification on the circumference.

[Brief description of drawings]

FIG. 1 is a schematic view showing a first embodiment of a laser processing apparatus according to the present invention.

FIG. 2 is a schematic view showing a second embodiment of the laser processing apparatus according to the present invention.

FIG. 3 is a schematic view showing a third embodiment of the laser processing apparatus according to the present invention.

FIG. 4 is a schematic view showing an example of a conventional laser processing apparatus.

FIG. 5 is a schematic view showing another example of a conventional laser processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Laser beam 2 ... Ring-shaped laser beam 3 ... Beam guide mirror 3a ... Aperture 4 ... Beam deformation mirror 4a ... Reflection part of conical outer surface 4b ... Reflection part of conical inner surface 5, 15, 25 ... Condensing mirror 5a , 25a ... Aperture 6 ... Workpiece 7 ... Quenched portion 8 ... Exhaust device 9 ... Beam absorber 10 ... Processing gas jetting device 11 ... Focusing mirror 21 ... Focusing diameter conversion mirror

Claims (9)

[Claims] 1. A laser processing apparatus for reflecting and condensing a laser beam and entering the workpiece to perform laser processing, wherein a ring-shaped laser beam has a ring-shaped intensity distribution in a cross section orthogonal to the traveling direction of the laser beam. A laser processing apparatus comprising a condenser mirror for reflecting and condensing a laser beam. 2. The laser processing apparatus according to claim 1, wherein the condensing mirror has an opening for inserting a workpiece in a central portion thereof. 3. A process which is provided on the rear surface side of the opening of the condenser mirror, injects a processing assist gas, and introduces it into the reflection surface side of the condenser mirror through the opening of the condenser mirror. The gas jetting device, and an exhaust device which is provided in the vicinity of the converging point of the condensing mirror and exhausts a processing point atmosphere gas at the time of processing from the outer periphery of the workpiece. The laser processing device described. 4. The laser processing apparatus according to claim 2, further comprising a beam absorber provided near the converging point of the condenser mirror and absorbing a laser beam. 5. The laser processing apparatus according to claim 1, wherein the condensing mirror has a condensing point outside an outer peripheral end portion in the radial direction thereof. 6. The condensing mirror is configured to intersect the ring-shaped laser beam reflected and condensed on the central axis thereof, and has an opening provided at the center thereof and inserted into the opening. And a condensing diameter converting mirror capable of condensing the condensing diameter converting mirror. When the condensing diameter converting mirror is inserted into the opening, the condensing mirror reflects and condenses the ring-shaped laser beam reflected and condensed. The laser processing apparatus according to claim 5, wherein the laser processing apparatus is configured to convert a diameter. 7. The laser processing according to claim 1, further comprising a beam deforming mirror which is provided on an incident side of the condensing mirror and which injects a laser beam to deform it into the ring-shaped laser beam. apparatus. 8. The beam deforming mirror has, at its center, a conical outer surface reflecting portion that reflects the laser beam in a circular shape in the outer peripheral direction, and the outer peripheral portion of the conical outer surface reflecting portion. The laser processing apparatus according to claim 7, further comprising: a conical inner surface reflecting portion that further reflects the laser beam reflected by the conical outer surface reflecting portion to form the ring-shaped laser beam. 9. A beam guide mirror, which is provided on an incident side of the condenser mirror, has an opening for penetrating a laser beam, and reflects the ring-shaped laser beam around the opening, the beam guide mirror further comprising: The guide mirror, the condensing mirror, and the beam deforming mirror cause a laser beam penetrating the opening of the beam guide mirror to enter the beam deforming mirror and deform the laser beam into the ring laser beam. The laser processing apparatus according to claim 7, wherein the laser processing apparatus is arranged so as to be reflected around the opening of the beam guide mirror and to be incident on the condenser mirror.