JP6955934B2 - Laser processing machine - Google Patents

Description

The present invention relates to a laser processing machine that processes a metal plate (sheet metal) by laser light.

Laser processing machines that cut or weld sheet metal with laser light emitted from a laser oscillator or mark the sheet metal are widely used. Various laser oscillators are used in the laser processing machine. For example, a fiber laser oscillator is often used for cutting a relatively thin sheet metal at high speed.

Japanese Patent Application Laid-Open No. 2015-500571 International Publication No. 2011/124671

The laser processing machine needs to appropriately set the beam profile of the laser beam to be applied to the sheet metal according to the processing conditions of the sheet metal. Patent Documents 1 and 2 describe a laser processing machine capable of processing a sheet metal by selecting one of a plurality of beam profiles.

The configuration for selecting the beam profile described in Patent Documents 1 and 2 is complicated, and a laser processing machine capable of selecting the beam profile with a simple and inexpensive configuration is desired.

An object of the present invention is to provide a laser processing machine capable of processing a sheet metal by selecting one of a plurality of beam profiles with a simple and inexpensive configuration.

The present invention comprises a concave-convex axicon lens having a convex curved surface as an incident surface of laser light, a concave axicon surface as an emission surface of laser light, and a Gaussian-type beam profile for transmitting divergent light laser light, and a laser light. A plano-convex axicon lens having a convex axicon surface as an incident surface and a flat surface as a laser beam emitting surface and transmitting the laser light emitted from the uneven axicon lens, and a laser emitted from the plano-convex axicon lens. A focusing lens that focuses light and irradiates the sheet metal to be processed, a first moving mechanism for moving the uneven axicon lens in the optical axis direction, and the uneven axicon lens by the first moving mechanism. A first driving unit for moving the plano-convex axicon lens in the optical axis direction, a second moving mechanism for moving the plano-convex axicon lens in the optical axis direction, and the plano-convex axicon by the second moving mechanism. The beam profile of the laser beam focused by the focusing lens by bringing the second driving unit that drives the conlens to move in the optical axis direction, the uneven axicon lens, and the plano-convex axicon lens close to each other. In the first mode in which the lens is of the Gaussian type, the uneven axicon lens and the plano-convex axicon lens are separated from each other, and the uneven axicon lens and the plano-convex axicon lens are separated from each other. The uneven axicon lens is moved so as to be located at a position away from the focusing lens or a position closer to the focusing lens as compared with the position of the uneven axicon lens in the first mode. The uneven axicon lens and the plano-convex axicon so as to switch between the second mode in which the beam profile of the laser light is ring-shaped on the back side or the front side of the focusing point of the laser light focused by the focusing lens. providing Relais chromatography the machine includes a controller for controlling each position of the lens.
Further, the present invention includes a concave-convex axicon lens having a convex curved surface as an incident surface of laser light and a concave axicon surface as an emission surface of laser light, and having a Gaussian-type beam profile to transmit divergent light laser light, and a laser. A plano-convex axicon lens that has a convex axicon surface as an incident surface of light and a flat surface as an emission surface of laser light and transmits laser light emitted from the uneven axicon lens, and a plano-convex axicon lens that is emitted from the plano-convex axicon lens. The focusing lens that focuses the laser beam and irradiates the sheet metal to be processed, the first moving mechanism for moving the uneven axicon lens in the optical axis direction, and the uneven axi by the first moving mechanism. A first driving unit that drives the conlens to move in the optical axis direction, a second moving mechanism for moving the plano-convex axicon lens in the optical axis direction, and the flatness by the second moving mechanism. A second driving unit that drives the convex axicon lens to move in the optical axis direction, the uneven axicon lens and the plano-convex axicon lens are brought close to each other, and the laser beam focused by the focusing lens. In the first mode in which the beam profile is Gaussian type and the position of the uneven axicon lens is the same as the position of the uneven axicon lens in the first mode, the plano-convex axicon lens is said to be the same. Separated from the uneven axicon lens, the second mode in which the beam profile of the laser light is ring-shaped is switched on both the front side and the back side of the focusing point of the laser light focused by the focusing lens. Provided is a laser processing machine including an uneven axicon lens and a control device for controlling each position of the plano-convex axicon lens.

Further , the present invention has a convex lens in which a laser beam of divergent light is incident and converted into convergent light, and a concave lens in which a laser beam of convergent light emitted from the convex lens is incident, and is emitted from the convex lens. By a beam diameter variable device that changes the beam diameter emitted from the concave lens according to the convergence angle of the focused light, a first moving mechanism for moving the convex lens in the optical axis direction, and the first moving mechanism. A first driving unit that drives the convex lens to move in the optical axis direction, a second moving mechanism for moving the concave lens in the optical axis direction, and the second moving mechanism move the concave lens in the optical axis direction. A second drive unit that drives the light to move the beam, and the laser light emitted from the beam diameter variable device are incident, and the plano-concave axis having a flat surface as the incident surface of the laser light and a concave axicon surface as the emission surface of the laser light. It has a conlens, a convex axicon surface as an incident surface of laser light, and a convex curved surface as an emission surface of laser light, and focuses the laser light emitted from the plano-concave axicon lens to irradiate the sheet metal to be processed. The biconvex axicon lens, the third moving mechanism for moving the plano-concave axicon lens in the optical axis direction, and the third moving mechanism so as to move the plano-concave axicon lens in the optical axis direction. With the third driving unit to be driven and the beam diameter variable device emitting parallel light, the plano-concave axicon lens is brought close to the biconvex axicon lens, and the biconvex axicon lens is used. The plano-concave axicon lens is separated from the biconvex axicon lens in the first mode in which the beam profile of the focused laser light is of the Gaussian type and in the state where the beam diameter variable device emits divergent light. The convex lens, the concave lens, and the flat lens so as to switch between the second mode in which the beam profile of the laser light is ring-shaped behind the focusing point of the laser light focused by the biconvex axicon lens. and a control device for controlling the respective positions of the concave axicon lens provides Relais chromatography tHE machine.

According to the laser processing machine of the present invention, it is possible to process a sheet metal by selecting one of a plurality of beam profiles with a simple and inexpensive configuration.

It is a figure which shows the overall configuration example of the laser processing machine of 1st Embodiment. It is a figure which shows the detailed configuration example of the collimator unit in the laser processing machine of 1st Embodiment. It is a figure for demonstrating the change of the beam profile in the laser processing machine of 1st Embodiment. It is a figure which shows the Gaussian type beam profile. It is a figure which shows the beam profile of a thick ring type. It is a figure which shows the beam profile of a sharp ring type. It is a figure which shows the beam profile in which a predetermined intensity exists in the center of a thick ring. It is a figure which shows the beam profile in which a predetermined intensity exists in the center of a sharp ring. It is a figure which shows the uneven axicon lens and the plano-convex axicon lens used in the laser processing machine of 2nd Embodiment. It is a figure which shows the uneven axicon lens and the plano-convex axicon lens used in the laser processing machine of 3rd Embodiment. It is a figure which shows the uneven axicon lens and the plano-convex axicon lens used in the laser processing machine of 4th Embodiment. It is a figure for demonstrating the change of the beam profile in the laser processing machine of 4th Embodiment. It is a figure which shows the detailed configuration example of the collimator unit in the laser processing machine of 5th Embodiment. It is a figure for demonstrating the change of the beam profile in the state which increased the beam diameter by the beam diameter variable apparatus in the laser processing machine of 5th Embodiment. It is a figure for demonstrating the change of the beam profile in the state which reduced the beam diameter by the beam diameter variable apparatus in the laser processing machine of 5th Embodiment.

Hereinafter, the laser processing machines of the first to fifth embodiments will be described with reference to the accompanying drawings. In the laser processing machine of the first to fifth embodiments, the same reference numerals are given to the portions having the same function, and the description thereof may be omitted.

<First Embodiment>
In FIG. 1, the laser processing machine 100 includes a laser oscillator 10 that generates and emits laser light, a laser processing unit 20, and a process fiber 12 that transmits the laser light emitted from the laser oscillator 10 to the laser processing unit 20. And. Further, the laser machining machine 100 includes an operation unit 40 and an NC device 50 that controls the laser oscillator 10 and the laser machining unit 20. The NC device 50 is an example of a control device.

As the laser oscillator 10, a laser oscillator that amplifies the excitation light emitted from the laser diode and emits a laser beam having a predetermined wavelength, or a laser oscillator that directly uses the laser beam emitted from the laser diode is preferable. The laser oscillator 10 is, for example, a solid-state laser oscillator, a fiber laser oscillator, a disk laser oscillator, or a direct diode laser oscillator (DDL oscillator).

The laser oscillator 10 emits laser light in the 1 μm band having a wavelength of 900 nm to 1100 nm. Taking a fiber laser oscillator and a DDL oscillator as an example, the fiber laser oscillator emits a laser beam having a wavelength of 1060 nm to 1080 nm, and the DDL oscillator emits a laser beam having a wavelength of 910 nm to 950 nm.

The laser machining unit 20 includes a machining table 21 on which the sheet metal W to be machined is placed, a portal-shaped X-axis carriage 22, a Y-axis carriage 23, and a collimator unit 30 fixed to the Y-axis carriage 23. The X-axis carriage 22 is configured to be movable in the X-axis direction on the processing table 21. The Y-axis carriage 23 is configured to be movable on the X-axis carriage 22 in the Y-axis direction perpendicular to the X-axis.

The collimator unit 30 includes an uneven axicon lens 31 on which the laser beam indicated by a single point chain line emitted from the ejection end of the process fiber 12 is incident, and a plano-convex axicon lens on which the laser beam emitted from the uneven axicon lens 31 is incident. 32 and. Further, the collimator unit 30 reflects the laser beam emitted from the plano-convex axicon lens 32 downward in the Z-axis direction perpendicular to the X-axis and the Y-axis, and the laser beam reflected by the bend mirror 33. It has a focusing lens 34 for focusing and a processing head 35.

The laser processing machine 100 configured as described above processes the sheet metal W by the laser light emitted from the laser oscillator 10. The processing of the sheet metal W may be either cutting or welding of the sheet metal W or marking on the sheet metal W.

A detailed configuration example of the collimator unit 30 will be described with reference to FIG. In FIG. 2, the laser beam of the divergent light indicated by the alternate long and short dash line emitted from the emission end 12e of the process fiber 12 is incident on the uneven axicon lens 31. The uneven axicon lens 31 has a concave axicon surface in which the incident surface 31a1 of the laser light is a convex curved surface and the emission surface 31b1 of the laser light is a concave conical surface. The curvature of the injection surface 31b1 is 0.

The uneven axicon lens 31 is attached to a moving mechanism 311 for making the uneven axicon lens 31 movable in the optical axis direction. When the driving unit 312 drives the moving mechanism 311, the uneven axicon lens 31 moves in the optical axis direction as shown by an arrow.

The laser beam emitted from the ejection surface 31b1 of the uneven axicon lens 31 is incident on the plano-convex axicon lens 32. The plano-convex axicon lens 32 has a convex axicon surface in which the incident surface 32a1 of the laser light is a convex conical surface and a flat surface in the emission surface 32b1 of the laser light. The curvature of the incident surface 32a1 is 0.

The plano-convex axicon lens 32 is attached to a moving mechanism 321 for making the plano-convex axicon lens 32 movable in the optical axis direction. When the driving unit 322 drives the moving mechanism 321, the plano-convex axicon lens 32 moves in the optical axis direction as shown by an arrow.

The moving mechanisms 311 and 321 may be, for example, any of gears, belts, rack and pinions, worm gears, ball screws and the like (or any combination thereof), and the drive units 312 and 312 are, for example, motors. The NC device 50 controls the drive unit 312 to move the uneven axicon lens 31, and controls the drive unit 322 to move the plano-convex axicon lens 32. The drive units 312 and 322 may be controlled by a control device other than the NC device 50.

The incident surface 31a1 of the uneven axicon lens 31 is set to have a curvature that converts divergent light into parallel light when the distance from the ejection end 12e to the surface of the incident surface 31a1 is d1. The ejection surface 31b1 of the uneven axicon lens 31 converts parallel light into divergent light. Divergent light is incident on the incident surface 32a1 of the plano-convex axicon lens 32. The angles of the ejection surface 31b1 and the incident surface 32a1 with respect to the optical axes are set so as to convert the divergent light into parallel light by the refractive action of both.

Since the ejection surface 32b1 is flat, parallel light is incident on the bend mirror 33. The parallel light whose optical axis is bent by 90 degrees by the bend mirror 33 is focused by the focusing lens 34 so that the focal position is at or near the surface of the sheet metal W, and is applied to the sheet metal W.

Since the collimator unit 30 can be arbitrarily moved in the X-axis direction and the Y-axis direction by the X-axis carriage 22 and the Y-axis carriage 23, the position where the laser beam emitted from the processing head 35 irradiates the sheet metal W is set on the X-axis. It can be arbitrarily moved in the direction and the Y-axis direction.

Although not shown in FIG. 2, the focusing lens 34 may be configured to be movable in the optical axis direction so that the focal position of the laser beam irradiating the sheet metal W can be changed. In this case, a moving mechanism and a driving unit for moving the focusing lens 34 may be provided.

As described above, the laser processing machine 100 of the first embodiment includes the uneven axicon lens 31 and the plano-convex axicon lens 32, and the uneven axicon lens 31 and the plano-convex axicon lens 32 are movable in the optical axis direction. It is configured in. Therefore, as will be described later, according to the laser processing machine 100 of the first embodiment, the beam profile of the laser beam irradiating the sheet metal W can be selected from a plurality of beam profiles. The laser processing machine 100 of the first embodiment can process the sheet metal W using the selected beam profile.

With reference to FIG. 3, how the beam profile changes according to the positions of the uneven axicon lens 31 and the plano-convex axicon lens 32 in the laser processing machine 100 of the first embodiment will be described. In FIG. 3, the bend mirror 33 is omitted, and the uneven axicon lens 31, the plano-convex axicon lens 32, and the focusing lens 34 are conceptually arranged so that the optical axis is in a straight line. In FIG. 3, Li indicates an inner beam in the luminous flux, and Lo indicates an outer beam in the luminous flux.

The laser beam emitted from the emission end 12e has a Gaussian-type beam profile as shown in FIG. 4A. The beam profile is a characteristic (shape) that shows the intensity distribution when the laser beam is viewed in cross section. The Gaussian-type beam profile has a characteristic that the intensity increases sharply from the peripheral portion to the central portion.

FIG. 3A shows a state in which the plano-convex axicon lens 32 is moved so as to be close to the uneven axicon lens 31. The beam collimated by the uneven axicon lens 31 is collimated at substantially the same position inside the plano-convex axicon lens 32 (it travels as parallel light as it is). The uneven axicon lens 31 and the plano-convex axicon lens 32 that are close to each other function substantially in the same manner as the plano-convex lens. Therefore, the beam profile of the laser beam focused by the focusing lens 34 having a predetermined focal length is a Gaussian type as shown in FIG. 4A (first mode in claim 1) .

FIG. 3B shows a state in which only the plano-convex axicon lens 32 is moved away from the uneven axicon lens 31 from the state of FIG. 3A. In FIG. 3B, a region where no beam exists is generated inside the inner beam Li, and the collimated beam propagating from the plano-convex axicon lens 32 to the focusing lens 34 looks like a thick ring. It becomes a state. Beam profile of the laser beam focused by the focusing lens 34, the Gaussian type in focal points in front and rear side of the focal point (the left and right side of FIG. 3), a thick ring-shaped as shown in FIG. 4B ( The third mode in claim 7 and the second mode in claim 8) .

FIG. 3C shows a state in which the uneven axicon lens 31 and the plano-convex axicon lens 32 are moved from the state of FIG. 3B to the injection end 12e side by the same distance from each other. .. At this time, the inner beam Li and the outer beam Lo passing through the uneven axicon lens 31 and the plano-convex axicon lens 32 become divergent light, respectively, and the divergence angle of the beam Lo is larger than the divergence angle of the beam Li.

When the focusing lens 34 focuses the beams Li and Lo, the beam Lo focuses on the back side (right side in FIG. 3) of the beam Li, so that the focusing point moves to the back side. The beam profile of the laser beam focused by the focusing lens 34 has a sharp ring shape as shown in FIG. 4C behind the focusing point (second mode in claim 1) . The beam profile on the front side of the focusing point and on the focusing point has a sharper peak at the center than the Gaussian type shown in FIG. 4A.

FIG. 3D shows a state in which the uneven axicon lens 31 and the plano-convex axicon lens 32 are moved from the state of FIG. 3B to the focusing lens 34 side by the same distance from each other. .. At this time, the inner beam Li and the outer beam Lo passing through the uneven axicon lens 31 and the plano-convex axicon lens 32 become convergent light, respectively, and the convergence angle of the beam Lo is larger than the convergence angle of the beam Li.

When the focusing lens 34 focuses the beams Li and Lo, the beam Lo focuses on the front side of the beam Li, so that the focusing point moves to the front side. The beam profile of the laser beam focused by the focusing lens 34 has a sharp ring shape as shown in FIG. 4C on the front side of the focusing point (second mode in claim 1) . It should be noted that the beam profile has a sharp peak at the center at the focusing point and the back side of the focusing point.

As shown in FIG. 3A, a mode in which the uneven axicon lens 31 and the plano-convex axicon lens 32 are brought close to each other and the beam profile is Gaussian type is defined as the first mode. As shown in (c) or (d) of FIG. 3, a mode in which the uneven axicon lens 31 and the plano-convex axicon lens 32 are separated from each other and the beam profile is ring-shaped is defined as the second mode. The NC device 50 can switch between the first mode and the second mode.

In the first mode, assuming that the distance from the injection end 12e to the incident surface 31a1 of the uneven axicon lens 31 is the first distance, in the second mode, the distance from the injection end 12e to the incident surface 31a1 is the first. It is a second distance that is different from the distance of.

In the laser processing machine 100 of the first embodiment, the curvature of the incident surface 31a1 of the uneven axicon lens 31 is set so that the distance d1 is 120 mm, the angle of the concave axicon surface of the injection surface 31b1 and the plano-convex axicon lens. It is assumed that the angle of the convex axicon surface of the incident surface 32a1 at 32 is set to 9 degrees. The uneven axicon lens 31 is moved 5 mm from the state of (a) in FIG. 3 to the injection end 12e side, and the distance between the uneven axicon lens 31 and the plano-convex axicon lens 32 is 40 mm, and the uneven axicon lens 31 is shown in FIG. 3 (c). Suppose that it is in a state. Then, a ring-shaped beam profile having a diameter of about 400 μm is formed behind the focusing point.

<Second Embodiment>
The laser processing machine 100 of the second embodiment has a configuration in which the uneven axicon lens 31 in FIG. 1 is replaced with the uneven axicon lens 31B shown in FIG.

In FIG. 5, in the uneven axicon lens 31B, the incident surface 31a2 is a convex curved surface and the ejection surface 31b2 is a concave axicon surface. The curvature of the incident surface 31a2 is smaller than the curvature of the incident surface 31a1 of the uneven axicon lens 31 indicated by the alternate long and short dash line.

The uneven axicon lens 31B is similar to the uneven axicon lens 31 in that the curvature of the incident surface 31a2 is made smaller than the curvature of the incident surface 31a1 by imparting a predetermined convex curvature to the ejection surface 31b2. It is configured to work. In order to compare the injection surface 31b1 and the injection surface 31b2, the injection surface 31b1 is shown by a chain double-dashed line.

<Third Embodiment>
The laser processing machine 100 of the third embodiment has a configuration in which the uneven axicon lens 31 and the plano-convex axicon lens 32 in FIG. 1 are replaced with the uneven axicon lens 31C and the plano-convex axicon lens 32C shown in FIG. 6, respectively. ..

In FIG. 6, in the uneven axicon lens 31C, the incident surface 31a2 is a convex curved surface and the ejection surface 31b1 is a concave axicon surface. The curvature of the incident surface 31a2 is smaller than the curvature of the incident surface 31a1 of the uneven axicon lens 31 indicated by the alternate long and short dash line.

In the plano-convex axicon lens 32C, the incident surface 32a2 is a convex axicon surface and the ejection surface 32b1 is a flat surface. The amount that the curvature of the incident surface 31a2 of the uneven axicon lens 31C is smaller than the curvature of the incident surface 31a1 is compensated by imparting a predetermined convex curvature to the incident surface 32a2 of the plano-convex axicon lens 32C.

As a result, the uneven axicon lens 31C and the plano-convex axicon lens 32C are configured to perform the same functions as the uneven axicon lens 31 and the plano-convex axicon lens 32. In order to compare the incident surface 31a1 and the incident surface 31a2, the incident surface 31a1 is shown by a chain double-dashed line.

<Fourth Embodiment>
The laser processing machine 100 of the fourth embodiment has a configuration in which the uneven axicon lens 31 and the plano-convex axicon lens 32 in FIG. 1 are replaced with the uneven axicon lens 31D and the plano-convex axicon lens 32D shown in FIG. 7, respectively. ..

As shown in FIG. 7, the uneven axicon lens 31D has a flat surface 31b4 at the center of the injection surface 31b3 which is a concave axicon surface, and the plano-convex axicon lens 32D has a central portion of the incident surface 32a3 which is a convex axicon surface. Is a plane 32a4.

With reference to FIG. 8, how the beam profile changes depending on the positions of the uneven axicon lens 31D and the plano-convex axicon lens 32D in the laser processing machine 100 of the fourth embodiment will be described. Also in FIG. 8, the bend mirror 33 is omitted, and the uneven axicon lens 31D, the plano-convex axicon lens 32D, and the focusing lens 34 are conceptually arranged so that the optical axis is in a straight line. In FIG. 8, Li indicates an inner beam, Lo indicates an outer beam, and Lc indicates a central beam passing through planes 31b4 and 32a4.

The action of the uneven axicon lens 31D and the plano-convex axicon lens 32D on the inner beam Li and the outer beam Lo is the same as the action of the uneven axicon lens 31 and the plano-convex axicon lens 32. Therefore, the action due to the presence of the beam Lc on the central side will be described.

FIG. 8A shows a state in which the plano-convex axicon lens 32D is moved so as to be close to the uneven axicon lens 31D. FIG. 8A is the same as FIG. 3A, and the beam profile of the laser beam focused by the focusing lens 34 is a Gaussian type as shown in FIG. 4A.

FIG. 8B shows a state in which only the plano-convex axicon lens 32D is moved away from the uneven axicon lens 31D from the state of FIG. 8A. In FIG. 8B, since the beam Lc on the center side passing through the planes 31b4 and 32a4 exists inside the inner beam Li, it is on the front side and the back side (left side and right side of FIG. 8) of the focusing point. As shown in FIG. 4D, the beam profile has a predetermined intensity even in the center of the thick ring.

FIG. 8C shows a state in which the uneven axicon lens 31D and the plano-convex axicon lens 32D are moved from the state of FIG. 8B to the injection end 12e side by the same distance from each other. .. Behind the focusing point, as shown in FIG. 4E, the beam profile has a predetermined intensity even in the center of the sharp ring.

FIG. 8D shows a state in which the uneven axicon lens 31D and the plano-convex axicon lens 32D are moved from the state of FIG. 8B to the focusing lens 34 side by the same distance from each other. .. The beam profile shown in FIG. 4E is on the front side of the focusing point.

In the laser processing machine 100 of the first embodiment, if the diameter of the ring of the ring type beam profile is increased, the energy at the center of the ring may be insufficient. According to the laser processing machine 100 of the fourth embodiment, the energy at the center of the ring can be supplemented.

<Fifth Embodiment>
In the collimator unit 30 shown in FIG. 9, the uneven axicon lens 31 and the plano-convex axicon lens 32 in the collimator unit 30 shown in FIG. 2 are replaced with the convex lens 36 and the concave lens 37, respectively. The convex lens 36 is a biconvex lens having a positive focal length, and the concave lens 37 is a biconcave lens having a negative focal length.

Further, in the collimator unit 30 shown in FIG. 9, the focusing lens 34 is replaced with a plano-concave axicon lens 38 and a biconvex axicon lens 39. The laser processing machine 100 of the fifth embodiment has the above configuration.

The convex lens 36 is attached to a moving mechanism 361 for making the convex lens 36 movable in the optical axis direction. When the driving unit 362 drives the moving mechanism 361, the convex lens 36 moves in the optical axis direction as shown by an arrow. The concave lens 37 is attached to a moving mechanism 371 for making the concave lens 37 movable in the optical axis direction. When the driving unit 372 drives the moving mechanism 371, the concave lens 37 moves in the optical axis direction as shown by an arrow.

As will be described later, the convex lens 36 and the concave lens 37 constitute a beam diameter variable device 367 that changes the beam diameter D.

The plano-concave axicon lens 38 has a concave axicon surface in which the incident surface 38a of the laser light is a flat surface and the emission surface 38b of the laser light is a concave conical surface. The curvature of the injection surface 38b is zero. In the biconvex axicon lens 39, the incident surface 39a of the laser beam is a convex axicon surface, and the emission surface 39b of the laser beam is a convex curved surface. The curvature of the incident surface 39a is zero.

The plano-concave axicon lens 38 is attached to a moving mechanism 381 for making the plano-concave axicon lens 38 movable in the optical axis direction. When the driving unit 382 drives the moving mechanism 381, the plano-concave axicon lens 38 moves in the optical axis direction as shown by an arrow.

The moving mechanisms 361, 371, and 381 may have the same mechanism as the moving mechanisms 311 and 321. The drive units 362, 372, and 382 are, for example, motors. The NC device 50 controls the drive units 362, 372, and 382 to move the convex lens 36, the concave lens 37, and the plano-concave axicon lens 38, respectively.

In FIG. 9, the convex lens 36 is arranged so that the distance from the ejection end 12e to the convex lens 36 is equal to or greater than the focal length of the convex lens 36. Therefore, the convex lens 36 converts the divergent light of the laser light into the focused light. The NC device 50 can move the convex lens 36 in the optical axis direction under the condition that the distance from the ejection end 12e to the convex lens 36 is equal to or greater than the focal length of the convex lens 36.

Assuming that the concave lens 37 does not exist, the focused light emitted from the convex lens 36 is focused at a predetermined position as a focusing point. The concave lens 37, the convex lens 36 side of the converging point, lever be placed in a position shifted by the same distance as the focal length of the concave lens 37 (reference position), the concave lens 37 converts the convergent light into parallel light. If the concave lens 37 is arranged on the convex lens 36 side from the focusing point at a position shifted by a distance longer than the focal length of the concave lens 37, the concave lens 37 converts the focused light into divergent light.

The beam diameter D of the laser beam emitted from the concave lens 37 changes according to the convergence angle of the convergent light emitted from the convex lens 36. The beam diameter variable device 367 can change the beam diameter D.

With reference to FIGS. 10A and 10B, how the beam diameter D and the beam profile change in the laser processing machine 100 of the fifth embodiment will be described. In FIGS. 10A and 10B, the concept is that the bend mirror 33 is omitted and the convex lens 36, the concave lens 37, the plano-concave axicon lens 38, and the biconvex axicon lens 39 are arranged so that the optical axis is in a straight line. Is shown.

FIGS. 10A and 10A show a state in which the distance between the convex lens 36 and the concave lens 37 is short, the concave lens 37 is in the reference position with respect to the convex lens 36, and the concave lens 37 emits parallel light. There is. At this time, the beam diameter D becomes large because the convergence angle of the convergent light emitted from the convex lens 36 is large.

FIG. 10A (a) shows a state in which the plano-concave axicon lens 38 is moved so as to be close to the biconvex axicon lens 39. The plano-concave axicon lens 38 and the biconvex axicon lens 39, which are in close proximity to each other, function substantially in the same manner as a plano-convex focusing lens. Therefore, the beam profile of the laser beam focused by the plano-concave axicon lens 38 and the biconvex axicon lens 39 is a Gaussian type as shown in FIG. 4A (first mode in claim 9) .

FIG. 10A (b) shows a state in which only the plano-concave axicon lens 38 is moved away from the biconvex axicon lens 39 from the state of FIG. 10A (a). The beam profile of the laser beam focused by the biconvex axicon lens 39 is a Gaussian type at the focusing point, and a thick ring type as shown in FIG. 4B on the front side and the back side (left side and right side of FIG. 10A) of the focusing point. (Third mode in claim 10) .

FIG. 10A (c) shows a state in which the concave lens 37 is moved to the convex lens 36 side from the state of FIG. 10A (b). The concave lens 37 emits divergent light. At this time, the beam profile of the laser beam focused by the biconvex axicon lens 39 becomes a sharp ring type (second mode in claim 9) as shown in FIG. 4C on the back side of the focusing point. In addition, in (b) and (c) of FIG. 10A, the Rayleigh length is relatively short.

In FIGS. 10B (a) and 10B, the convex lens 36 is moved toward the ejection end 12e so that the distance between the convex lens 36 and the concave lens 37 is longer than that in FIGS. 10A (a) and 10A. Indicates the state. The concave lens 37 is in the reference position with respect to the convex lens 36, and the concave lens 37 emits parallel light. At this time, since the convergence angle of the convergent light emitted from the convex lens 36 is smaller than that in FIGS. 10A (a) and 10A, the beam diameter D becomes small.

In FIG. 10B (a), the beam profile of the focused laser beam is of the Gaussian type, as in the case of FIG. 10A (a). However, the focusing diameter in (a) of FIG. 10B is smaller than that in (a) of FIG. 10A. The same applies to (b) and (c) of FIGS. 10B.

FIG. 10B (b) shows a state in which only the plano-concave axicon lens 38 is moved away from the biconvex axicon lens 39 from the state of FIG. 10B (a). The beam profile in (b) of FIG. 10B is the same as that of (b) of FIG. 10A.

FIG. 10B (c) shows a state in which the concave lens 37 is moved to the convex lens 36 side from the state of FIG. 10B (b). The concave lens 37 emits divergent light. The beam profile in (c) of FIG. 10B is the same as that of (c) of FIG. 10A. In addition, in (b) and (c) of FIG. 10B, the Rayleigh length is longer than that in (b) and (c) of FIG. 10A.

As described above, according to the laser processing machine 100 of the fifth embodiment, the function of changing the focusing diameter of the Gaussian type beam, the function of selecting the beam profile, and the function of changing the Rayleigh length of the ring type beam. And.

In the laser processing machine 100 of the first to fifth embodiments described above, the operator operates the operation unit 40 to operate the operation unit 40, such as the type of material of the sheet metal W, the thickness of the sheet metal W, the focusing diameter of the laser beam, the focal position, and the like. Various processing conditions can be set. The material of the sheet metal W is, for example, iron, stainless steel, aluminum, copper, and brass. The plate thickness of the sheet metal W is, for example, any plate thickness within a predetermined range, with 0.1 mm to 30 mm as a predetermined range.

In the laser processing machine 100 of the first to fourth embodiments, the NC device 50 has the uneven axicon lenses 31, 31B, 31C, 31D, and flat according to the processing conditions of the sheet metal W input by the operation unit 40. The positions of the convex axicon lenses 32, 32C and 32D are controlled. In the laser processing machine 100 of the fifth embodiment, the NC device 50 controls the positions of the convex lens 36, the concave lens 37, and the plano-concave axicon lens 38 according to the processing conditions of the sheet metal W input by the operation unit 40.

The present invention is not limited to the present embodiment described above, and various modifications can be made without departing from the gist of the present invention. The first to fifth embodiments can be combined with each other. For example, the second, third, and fifth embodiments can be combined with the configuration in which the center of the lens in the fourth embodiment is flat. It is possible to combine the fifth embodiment with a configuration in which the portion of the convex curved surface reduced in curvature in the second and third embodiments is supplemented by imparting a predetermined curvature to the other surface.

10 Laser oscillator 12 Process fiber 12e Ejection end 20 Laser processing unit 30 Collimator unit 31, 31B, 31C, 31D Concavo-convex Axicon lens 31b4, 32a4 Plane 32, 32C, 32D Plano-convex Axicon lens 33 Bend mirror 34 Condenser lens 36 Convex lens 37 Concave lens 38 Planar concave axicon lens 38
39 Biconvex axicon lens 40 Operation unit 50 NC device (control device)
100 Laser Machining Machine 311, 321, 361, 371, 381 Moving Mechanism 312, 322, 362, 372, 382 Drive 367 Beam Diameter Variable Device W Sheet Metal

Claims (11)

An uneven axicon lens that has a convex curved surface as the incident surface of the laser light, a concave axicon surface as the emission surface of the laser light, and has a Gaussian-type beam profile to transmit the laser light of the divergent light.
A plano-convex axicon lens that has a convex axicon surface as an incident surface of laser light and a flat surface as an emission surface of laser light and transmits the laser light emitted from the uneven axicon lens.
A focusing lens that focuses the laser light emitted from the plano-convex axicon lens and irradiates the sheet metal to be processed.
A first moving mechanism for moving the uneven axicon lens in the optical axis direction,
A first driving unit that drives the uneven axicon lens to move in the optical axis direction by the first moving mechanism, and
A second moving mechanism for moving the plano-convex axicon lens in the optical axis direction,
A second driving unit that drives the plano-convex axicon lens to move in the optical axis direction by the second moving mechanism, and
A first mode in which the uneven axicon lens and the plano-convex axicon lens are brought close to each other and the beam profile of the laser beam focused by the focusing lens is a Gaussian type, and the uneven axicon lens and the flat surface. The position of the uneven axicon lens and the plano-convex axicon lens in a state where the convex axicon lens is separated from each other and separated from each other, and the uneven axicon lens is the position of the uneven axicon lens in the first mode. Compared with, the lens is moved so as to be located at a position away from the focusing lens or a position closer to the focusing lens, and is located on the back side or the front side of the focusing point of the laser beam focused by the focusing lens. a control device a beam profile of the laser beam to switch and a second mode in which a ring-type, for controlling the respective positions of the convex-concave axicon lens and said planoconvex axicon lens in,
Relais over The machine equipped with. Laser light emitted from the ejection end of the process fiber is incident on the uneven axicon lens, and the distance from the ejection end to the convex curved surface is the first distance, and the uneven axicon lens and the plano-convex. When the axicon lenses are separated from each other, the convex curved surface and the concave axicon so that the plano-convex axicon lens emits parallel light due to the refractive action of the uneven axicon lens and the plano-convex axicon lens. The curvature of each of the surface and the convex axicon surface and the angle with respect to the optical axis of each of the concave axicon surface and the convex axicon surface are set.
The control device is
The uneven axicon lens and the plano-convex axicon lens in a state of being close to each other are set to the first mode by setting the distance from the ejection end to the convex curved surface as the first distance.
The uneven axicon lens and the plano-convex axicon lens in a state of being separated from each other are described by setting the distance from the ejection end to the convex curved surface as a second distance different from the first distance. Set to the second mode
Laser processing machine according to請Motomeko 1. The curvature of the concave axicon surface and the convex axicon surface is 0.
The convex curved surface converts divergent light into parallel light, the concave axicon surface converts parallel light into divergent light, and the convex axicon surface converts divergent light into parallel light.
Laser processing machine according to請Motomeko 2. The concave axicon surface has a predetermined curvature of the convex, laser processing machine according to請Motomeko 2 curvature Ru 0 der of the convex axicon surface. The curvature of the concave axicon surface is zero, the laser processing machine according the convex axicon surface in請Motomeko 2 that have a predetermined curvature of the convex. The concave axicon surface and laser processing machine according to any one of請Motomeko 1-5 center of the convex axicon surface that have respectively a plane. The control device further places the uneven axicon lens and the plano-convex axicon lens in a state of being separated from each other at the same position as the uneven axicon lens in the first mode. To switch to a third mode in which the beam profile of the laser beam is a ring type thicker than the ring type in the second mode on both the front side and the back side of the focusing point. The laser processing machine according to any one of claims 1 to 6, which controls each position of the uneven axicon lens and the plano-convex axicon lens. An uneven axicon lens that has a convex curved surface as the incident surface of the laser light, a concave axicon surface as the emission surface of the laser light, and has a Gaussian-type beam profile to transmit the laser light of the divergent light.
A plano-convex axicon lens that has a convex axicon surface as an incident surface of laser light and a flat surface as an emission surface of laser light and transmits the laser light emitted from the uneven axicon lens.
A focusing lens that focuses the laser light emitted from the plano-convex axicon lens and irradiates the sheet metal to be processed.
A first moving mechanism for moving the uneven axicon lens in the optical axis direction,
A first driving unit that drives the uneven axicon lens to move in the optical axis direction by the first moving mechanism, and
A second moving mechanism for moving the plano-convex axicon lens in the optical axis direction,
A second driving unit that drives the plano-convex axicon lens to move in the optical axis direction by the second moving mechanism, and
The first mode in which the uneven axicon lens and the plano-convex axicon lens are brought close to each other and the beam profile of the laser beam focused by the focusing lens is a Gaussian type, and the position of the uneven axicon lens are set. At the same position as the position of the uneven axicon lens in the first mode, the plano-convex axicon lens is separated from the uneven axicon lens, and the focusing point of the laser beam focused by the focusing lens. a control device a beam profile of the laser beam to switch and a second mode in which a ring-type, for controlling the respective positions of the convex-concave axicon lens and said planoconvex axicon lens in both front and back side of,
Relais over The machine equipped with. It has a convex lens on which a laser beam of divergent light is incident and converts it into convergent light, and a concave lens on which a laser beam of convergent light emitted from the convex lens is incident. A beam diameter variable device that changes the beam diameter emitted from the concave lens according to the above.
A first moving mechanism for moving the convex lens in the optical axis direction,
A first driving unit that drives the convex lens to move in the optical axis direction by the first moving mechanism, and
A second moving mechanism for moving the concave lens in the optical axis direction,
A second driving unit that drives the concave lens to move in the optical axis direction by the second moving mechanism, and
A plano-concave axicon lens that is incident with laser light emitted from the beam diameter variable device and has a flat surface as an incident surface of the laser light and a concave axicon surface as an emission surface of the laser light.
A biconvex axicon that has a convex axicon surface as the incident surface of the laser light and a convex curved surface as the emission surface of the laser light, and focuses the laser light emitted from the plano-concave axicon lens to irradiate the sheet metal to be processed. With the lens
A third moving mechanism for moving the plano-concave axicon lens in the optical axis direction,
A third driving unit that drives the plano-concave axicon lens to move in the optical axis direction by the third moving mechanism, and
With the beam diameter variable device emitting parallel light, the plano-concave axicon lens is brought close to the biconvex axicon lens to obtain a beam profile of laser light focused by the biconvex axicon lens. In the first mode of the Gaussian type and in a state where the beam diameter variable device emits divergent light, the plano-concave axicon lens is separated from the biconvex axicon lens, and the biconvex axicon lens is separated from the biconvex axicon lens. The positions of the convex lens, the concave lens, and the plano-concave axicon lens are controlled so as to switch between the second mode in which the beam profile of the laser light is ring-shaped behind the focusing point of the laser light focused by. Control device and
Relais over The machine equipped with. The control device is further focused by the biconvex axicon lens by separating the plano-concave axicon lens from the biconvex axicon lens while the beam diameter variable device is emitting parallel light. The convex lens, the concave lens, and the convex lens, the concave lens, so as to switch the beam profile of the laser light to a third mode in which the beam profile of the laser light is a ring type thicker than the ring type in the second mode on both the back side and the front side of the focusing point of the laser light. The laser processing machine according to claim 9, wherein the laser processing machine controls each position of the plano-concave axicon lens. The beam diameter variable device has the same distance as the focal length of the concave lens from the position where the convergent light emitted from the convex lens is focused to the convex lens side corresponding to the position of the convex lens in the optical axis direction. When it is located at a shifted position, the focused light is converted into parallel light, and when the concave lens is located at a position shifted to the convex lens side by a distance longer than the focal length of the concave lens, the focused light is shifted. The laser processing machine according to claim 9 or 10 , which is configured to convert light into divergent light.

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