JP6637916B2 - Laser processing machine - Google Patents

Description

  The present invention relates to a laser beam machine that cuts a metal plate using laser light.

2. Description of the Related Art A laser processing machine that cuts a metal plate with laser light emitted from a laser oscillator has been widely used. Various laser oscillators are used in a laser beam machine. In order to cut a relatively thin plate at a high speed, for example, a fiber laser oscillator is often used. The fiber laser oscillator has an advantage that it is suitable for high-speed cutting of a plate material, and also has an advantage that it is smaller and less expensive than a CO ₂ laser oscillator.

DE 10 2011 117 607 A1 Japanese Patent Publication No. 2015-500571

  Of the relatively thin plate members, a plate member having a plate thickness of, for example, 6 mm to 30 mm is referred to as a thick plate, and a plate member having a plate thickness of, for example, 0.1 mm to 6 mm is referred to as a thin plate. In the art, a plate having a plate thickness of, for example, 2 mm to 12 mm may be referred to as a medium-thick plate. It is difficult to cut a thick plate and a thin plate by changing only the processing conditions with the same laser processing machine. The processing conditions here include, for example, the power of the laser light, the duty of the pulse when pulsating the laser light, the focal position, the type of the assist gas, or the gas pressure.

  Therefore, in a conventional laser beam machine, in order to cut both a thick plate and a thin plate, it is necessary to exchange optical system elements such as lenses or components of the laser beam machine such as a processing nozzle. Since the replacement of the components is complicated and increases the cost, a laser beam machine capable of cutting both a thick plate and a thin plate without replacing the components is desired.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a laser beam machine capable of cutting a plate material having a predetermined range of plate thickness without exchanging components.

The present invention is over a beam parameter product varying device for varying a beam parameter product of the laser beam emitted from The oscillator, the beam parameter product variator beam diameter varying device for varying the beam diameter of the laser beam emitted from the And a third lens having a positive focal length and condensing the laser light emitted from the beam diameter variable device to irradiate the plate material, the beam diameter variable device,
A first lens that is movable in the optical axis direction, has a positive focal length, and converts divergent light of laser light emitted from the emission end of the laser light into convergent light, and is movable in the optical axis direction And a second lens having a negative focal length and on which the convergent light is incident, wherein the second lens corresponds to a position of the first lens in the optical axis direction. Is arranged on the first lens side from the position where the convergent light is converged, at a position shifted by the same distance as the focal length of the second lens, and converts the convergent light into parallel light. D is the beam diameter of the parallel light emitted from the second lens, BPP is the beam parameter product of the laser light set by the beam parameter product variable device, f is the focal length of the third lens, Focusing of laser light focused by the third lens The when the d, to the beam diameter D and Atsumariko径d to target satisfying the equation (1),
Wherein by controlling a beam parameter product variator sets the BPP to a predetermined value, and to provide further comprising les chromatography The machine control unit for determining the position of said first and second lenses.

In the above laser beam machine, a first moving mechanism for moving the first lens, a second moving mechanism for moving the second lens, and driving the first moving mechanism The apparatus further includes a first driving unit and a second driving unit that drives the second moving mechanism , wherein the control unit moves the first and second lenses according to processing conditions of the plate material. as, it is preferable to control the first and second driving portions.

In the above-mentioned laser beam machine, the control unit increases the beam diameter D of the laser light incident on the third lens so as to reduce the converging diameter d as the plate thickness of the plate material decreases, It is preferable to control the first and second driving units so that the beam diameter D of the laser light incident on the third lens is reduced so that the converging diameter d increases as the plate thickness increases .

At this time, before Symbol be first and second drive unit moves the first and second lens, the focal position of the laser beam focused on the plate is emitted from the third lens constant It is.

  In the above-mentioned laser beam machine, it is preferable that the third lens is movable in the optical axis direction and is configured to change the focal position of the laser beam.

In the above-mentioned laser beam machine, a first moving mechanism for moving the first lens, a second moving mechanism for moving the second lens, and a mechanism for moving the third lens. A third driving mechanism, a first driving section for driving the first moving mechanism, a second driving section for driving the second moving mechanism, and a second driving section for driving the third moving mechanism. And a third driving unit , wherein the control unit moves the first lens, the second lens, and the third lens in accordance with processing conditions of the plate material, the first lens, the second lens, and the third lens to move the first lens, the second lens, and the third lens. drive unit, said second driving unit, and a benzalkonium controls the third drive unit are preferred.

In the above-mentioned laser beam machine, the control unit increases the beam diameter D of the laser light incident on the third lens so as to reduce the converging diameter d as the plate thickness of the plate material decreases, It is preferable to control the first and second driving units so that the beam diameter D of the laser light incident on the third lens is reduced so that the converging diameter d increases as the plate thickness increases .

  ADVANTAGE OF THE INVENTION According to the laser beam machine of this invention, a board | plate material with a board thickness of a predetermined range can be cut and processed, without replacing a component part.

It is a perspective view showing the example of the whole composition of the laser beam machine of one embodiment. FIG. 2 is a diagram illustrating a schematic configuration when a laser oscillator 11 in FIG. 1 is configured by a fiber laser oscillator 11F. FIG. 2 is a diagram illustrating a schematic configuration when the laser oscillator 11 in FIG. 1 is configured by a direct diode laser oscillator 11D. FIG. 2 is a diagram illustrating a configuration example of a beam parameter product variable device 31 in FIG. 1. FIG. 2 is a diagram showing a schematic configuration example in which a convex lens 28, a concave lens 30, and a condenser lens 27 in FIG. 1 are movable. FIG. 3 is a diagram for explaining how to move a convex lens 28, a concave lens 30, and a condenser lens 27. It is a figure for explaining the condensing diameter and divergence angle of laser light. FIG. 5 is a diagram for explaining the operation of the beam parameter product variable device 31.

  Hereinafter, a laser processing machine according to an embodiment will be described with reference to the accompanying drawings. In FIG. 1, a laser processing machine 100 includes a laser oscillator 11 that generates and emits a laser beam, and a beam parameter product variable device 31 that varies a beam parameter product (Beam Parameter Products) of the laser beam emitted from the laser oscillator 11. And a laser processing unit 15. Hereinafter, the beam parameter product is referred to as BPP, and the beam parameter product variable device 31 is referred to as the BPP product variable device 31.

  The laser oscillator 11 and the variable BPP product 31 are connected by a feeding fiber 121, and the feeding fiber 121 transmits the laser light emitted from the laser oscillator 11 to the variable BPP product 31.

  The variable BPP product 31 and the laser processing unit 15 are connected by a process fiber 122, and the process fiber 122 transmits the laser light emitted from the variable BPP product 31 to the laser processing unit 15. The process fiber 122 is mounted along X-axis and Y-axis cable ducts (not shown) arranged in the laser processing unit 15.

  The laser beam machine 100 cuts and processes the metal plate W1 with the laser light emitted from the laser oscillator 11.

  As the laser oscillator 11, a laser oscillator that amplifies pump light emitted from a laser diode and emits laser light of a predetermined wavelength, or a laser oscillator that directly uses laser light emitted from a laser diode is preferable. The laser oscillator 11 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 processing unit 15 includes a processing table 21 on which the plate material W1 is placed, a gate-shaped X-axis carriage 22 movable on the processing table 21 in the X-axis direction, and a Y-axis perpendicular to the X-axis on the X-axis carriage 22. And a Y-axis carriage 23 that is movable in the direction. The laser processing unit 15 has a collimator unit 29 fixed to the Y-axis carriage 23.

  The collimator unit 29 has a convex lens 28 on which laser light emitted from the emission end of the process fiber 122 is incident, and a concave lens 30 on which laser light emitted from the convex lens 28 is incident. The collimator unit 29 includes a bend mirror 25 that reflects the laser light emitted from the concave lens 30 downward in the Z-axis direction perpendicular to the X-axis and the Y-axis, and a collector that collects the laser light reflected by the bend mirror 25. It has an optical lens 27 and a processing head 26.

  The convex lens 28 is a lens having a positive focal length, the concave lens 30 is a lens having a negative focal length, and the condenser lens 27 is a lens having a positive focal length. The condenser lens 27 is a convex lens. The convex lens 28 and the concave lens 30 have a function of a collimating lens for converting individual beams of the incident laser light into parallel light.

  As will be described later, the convex lens 28, the concave lens 30, and the condenser lens 27 are configured to be movable in the optical axis direction. The convex lens 28 and the concave lens 30 constitute a beam diameter varying device 32 (see FIG. 5 or FIG. 6) that varies the beam diameter.

  The convex lens 28 and the concave lens 30, the bend mirror 25, the condenser lens 27, and the processing head 26 are arranged in the collimator unit 29 with the optical axis adjusted in advance.

  The collimator unit 29 is fixed to a Y-axis carriage 23 movable in the Y-axis direction, and the Y-axis carriage 23 is provided on the X-axis carriage 22 movable in the X-axis direction. Therefore, the laser processing unit 15 can move the position at which the plate member W1 is irradiated with the laser light emitted from the processing head 26 in the X-axis direction and the Y-axis direction.

  With the above configuration, the laser beam machine 100 causes the laser beam emitted from the laser oscillator 11 to be transmitted to the laser beam processing unit 15 via the variable BPP product 31, and the laser beam focused by the focusing lens 27. To the plate material W1 to cut the plate material W1. In FIG. 1, the variable BPP product 31 is provided outside the laser oscillator 11, but the variable BPP product 31 may be provided inside the housing of the laser oscillator 11.

  When cutting the plate material W1, an assist gas for removing a melt is injected into the plate material W1. In FIG. 1, the illustration of the configuration for injecting the assist gas is omitted.

  FIG. 2 shows a schematic configuration when the laser oscillator 11 is configured by a fiber laser oscillator 11F. In FIG. 2, a plurality of laser diodes 110 each emit a laser beam having a wavelength λ. The excitation combiner 111 combines the laser beams emitted from the plurality of laser diodes 110 with a spatial beam.

  The laser light emitted from the excitation combiner 111 enters a Yb-doped fiber 113 between two fiber Bragg gratings (FBGs) 112 and 114. The Yb-doped fiber 113 is a fiber in which a rare earth element Yb (ytterbium) element is added to a core.

  The laser light incident on the Yb-doped fiber 113 repeats reciprocation between the FBGs 112 and 114, and the FBG 114 emits a laser light having a wavelength λ ′ (1 μm band) of approximately 1060 nm to 1080 nm different from the wavelength λ. The laser light emitted from the FBG 114 enters the feeding fiber 121 via the feeding fiber 115 and the beam coupler 116. The beam coupler 116 has lenses 1161 and 1162.

  FIG. 3 shows a schematic configuration in the case where the laser oscillator 11 is configured by a DDL oscillator 11D. In FIG. 3, a plurality of laser diodes 117 emit laser beams having wavelengths λ1 to λn different from each other. The wavelengths λ1 to λn (wavelength bands shorter than the 1 μm band) are, for example, 910 nm to 950 nm.

  The optical box 118 couples laser beams of wavelengths λ1 to λn emitted from the plurality of laser diodes 117 with a spatial beam. The optical box 118 has a collimating lens 1181, a grating 1182, and a condenser lens 1183.

  The collimator lens 1181 converts the laser light having the wavelengths λ1 to λn into parallel light. The grating 1182 bends the direction of the collimated laser light by 90 degrees and makes the laser light incident on the condenser lens 1183. The condenser lens 1183 condenses the incident laser light and makes the laser light incident on the feeding fiber 121.

  A configuration example of the BPP product variable device 31 will be described with reference to FIG. The variable BPP product device 31 includes a condenser lens 311 disposed between the exit end of the feeding fiber 121 and the entrance end of the process fiber 122, and a moving mechanism 312 for moving the position of the end of the feeding fiber 121. Having.

  As shown in FIG. 4, the process fiber 122 has a configuration in which a clad 1222 covers the periphery of a core 1221. The refractive index of the core 1221 is higher than the refractive index of the cladding 1222. The feeding fiber 121 has the same configuration.

  When the position of the end of the feeding fiber 121 with respect to the condenser lens 311 is changed by the moving mechanism 312, the incident position of the laser beam incident on the condenser lens 311 changes, and the condenser lens 311 is moved to the core 1221 of the process fiber 122. The incident angle of the laser light incident on the laser beam.

  When the feeding fiber 121 is at the position shown by the solid line, the laser light travels as shown by the solid line, and when the feeding fiber 121 is at the position shown by the dashed line, the laser light travels as shown by the dashed line. As a result, the BPP of the laser light emitted from the process fiber 122 changes.

  The BPP variable product device 31 is not limited to the configuration shown in FIG. 4 and may have any configuration as long as it can change the BPP. A configuration in which the position of the feeding fiber 121 is fixed and the lens is moved to change the incident angle of the laser beam incident on the process fiber 122 may be employed. A lens may be further provided at the incident end of the process fiber 122.

  A schematic configuration example in which the convex lens 28, the concave lens 30, and the condenser lens 27 are movable will be described with reference to FIG. In FIG. 5, a convex lens 28 and a concave lens 30 constituting the beam diameter varying device 32 have moving mechanisms 281 and 301 for moving the convex lens 28 and the concave lens 30 in the optical axis direction (X-axis direction in FIG. 1), respectively. Attached to. The condenser lens 27 is attached to a moving mechanism 271 that allows the condenser lens 27 to move in the optical axis direction (the Z-axis direction in FIG. 1).

  The moving mechanisms 281, 301, and 271 may use any one of a gear, a belt, a rack and pinion, a worm gear, a ball screw, or the like (or any combination thereof) to form the convex lens 28, the concave lens 30, and the condenser lens 27. Any mechanism may be used so that each of them can be freely moved.

  The convex lens 28, the concave lens 30, and the condenser lens 27 move in the optical axis direction as indicated by arrows by the driving units 282, 302, and 272 driving the moving mechanisms 281, 301, and 271 respectively. The driving units 282, 302, and 272 are, for example, motors.

  The control unit 50 controls the driving units 282, 302, and 272. The control unit 50 can be configured by a microprocessor. The control unit 50 may be an NC device that controls the entire laser processing machine 100.

  By operating the operation unit 51, the operator can set various processing conditions such as the type of the material of the plate material W1, the plate thickness of the plate material W1, the focused diameter of the laser beam, and the focal position. The material of the plate material W1 is, for example, iron, stainless steel, aluminum, copper, or brass. The plate thickness of the plate material W1 is any plate thickness within a predetermined range, for example, with 0.1 mm to 30 mm being a predetermined range.

  The control unit 50 controls the driving of the moving mechanisms 281 and 301 by the driving units 282 and 302 so as to adjust the positions of the convex lens 28 and the concave lens 30 according to the processing condition of the plate material W1 input by the operation unit 51.

  When the condensing diameter of the laser light is input by the operation unit 51, the control unit 50 controls the driving units 282 and 302 to adjust the positions of the convex lens 28 and the concave lens 30 according to the input condensing diameter. I do.

  Even if the focused diameter of the laser beam is not input, the optimum focused diameter is almost determined if the type and thickness of the plate material W1 are input. When the material type and the plate thickness of the plate material W1 are input by the operation unit 51, the control unit 50 controls the convex lens 28 and the concave lens 30 according to the input material type and the condensing diameter corresponding to the plate thickness. 282 and 302 can be controlled to adjust the position of.

  The control unit 50 may calculate the required light collecting diameter based on the processing conditions, or may read out the light collecting diameters corresponding to the respective processing conditions stored in advance.

  When the focal position is input by the operation unit 51, the control unit 50 controls the driving of the moving mechanism 271 by the driving unit 272 so as to adjust the position of the condenser lens 27 according to the input focal position. .

  In FIG. 5, laser light is emitted from the emission end 122e of the process fiber 122 as divergent light as indicated by a dashed line.

The convex lens 28 is arranged such that the distance from the exit end 122e to the convex lens 28 is equal to or longer than the focal length of the convex lens 28. Therefore, the convex lens 28 converts the divergent light of the laser light into convergent light. The control unit 50 can move the convex lens 28 in the optical axis direction under the condition that the distance from the exit end 122e to the convex lens 28 is equal to or longer than the focal length of the convex lens 28.

  When the concave lens 30 is arranged at an optimum position described later, the concave lens 30 converts the convergent light into parallel light. Here, the parallel light means that the light beam of the laser light is a parallel light. The parallel light emitted from the concave lens 30 is reflected by the bend mirror 25, the optical path is bent, and enters the condenser lens 27. The condenser lens 27 converges parallel light so that the focal position is at or near the surface of the plate W1, and irradiates the plate W1 with laser light.

  The control unit 50 may control the BPP product variable device 31 to change the BPP.

  The operation of the beam diameter varying device 32 will be described with reference to FIGS. FIGS. 6A to 6C conceptually show a state in which the bend mirror 25 in FIG. 5 is omitted and the convex lens 28, the concave lens 30, and the condenser lens 27 are arranged so that the optical axes are aligned. ing.

  6A to 6C, a position where the concave lens 30 does not exist and the convergent light from the convex lens 28 is collected is defined as a point Pf28. When the concave lens 30 is disposed at a position shifted by the same distance L as the focal length of the concave lens 30 from the point Pf28 toward the convex lens 28, the concave lens 30 converts convergent light into parallel light.

  As shown in FIGS. 6A and 6B, the beam diameter D of the parallel light emitted from the concave lens 30 changes according to the convergence angle of the converged light emitted from the convex lens 28.

  FIG. 7 conceptually shows an enlarged view of the periphery of the beam waist of the laser light focused on the surface of the plate material W1 or in the vicinity thereof. The left side of FIG. 7 is the upper side of the plate W1, and the right side is the lower side of the plate W1.

  The condensing diameter d is represented by Expression (1). The Rayleigh length Zr is represented by equation (2). In Expressions (1) and (2), f is the focal length of the condenser lens 27. The BPP is represented by the product of the radius d / 2 of the beam waist and the half width θ at half maximum of the divergence angle of the beam.

  The BPP does not change even if the convex lens 28 and the concave lens 30 or the condenser lens 27 is moved. Assuming that the BPP is not changed by the variable BPP product 31, the focusing diameter d and the Rayleigh length Zr are determined according to the beam diameter D according to equations (1) and (2). And the Rayleigh length Zr changes.

  As the beam diameter D increases, the condensing diameter d and the Rayleigh length Zr decrease, and the power density increases, resulting in a beam profile suitable for a thin plate. As the beam diameter D decreases, the condensing diameter d and the Rayleigh length Zr increase, and the power density decreases, resulting in a beam profile suitable for a thick plate.

  The control unit 50 calculates the beam diameter D that becomes the target condensing diameter d based on Expression (1), and sets the positions of the convex lens 28 and the concave lens 30 to be positions that realize the calculated beam diameter D. The driving units 282 and 302 are controlled to move the convex lens 28 and the concave lens 30.

  Specifically, the control unit 50 moves the convex lens 28 such that the convergence angle of the laser light emitted from the convex lens 28 becomes the convergence angle at which the target beam diameter D is obtained. In addition to this, the control unit 50 shifts the concave lens 30 from the point Pf28 to the convex lens 28 side by a distance L so as to convert convergent light into parallel light corresponding to the position of the convex lens 28 in the optical axis direction. Move.

  The control unit 50 calculates the positions of the convex lens 28 and the concave lens 30 to obtain the target beam diameter D and the condensing diameter d, and moves the convex lens 28 and the concave lens 30.

  As can be seen from FIGS. 6A and 6B, since the condenser lens 27 collects parallel light, the focal position of the laser beam does not change even if the position of the concave lens 30 changes.

  As described above, the control unit 50 increases the beam diameter D of the laser light incident on the condenser lens 27 so that the condensing diameter d decreases as the plate thickness of the plate W1 decreases. The driving units 282 and 302 are controlled so that the beam diameter D of the laser beam incident on the condenser lens 27 is reduced so that the focusing diameter d is increased as the thickness is increased. Even when the driving units 282 and 302 move the convex lens 28 and the concave lens 30, the focal position of the laser light emitted from the condenser lens 27 and focused on the plate W1 is constant and does not change.

  The light intensity distribution within the beam diameter D is formed by the reflection synthesis of the laser light transmitted to the core and the clad of the process fiber 122. As shown in FIGS. 6A and 6B, even if the beam diameter D changes, the light intensity distribution within the beam diameter D hardly changes, and even if it changes, it is extremely slight.

  When the control unit 50 moves the condenser lens 27, the focal position can be changed as shown in FIG. In some cases, instead of using the front surface of the plate material W1 as the focal position, cutting may be performed using a position slightly shifted from the front surface or the back surface of the plate material W1 as the focal position.

  When the focal position is input by the operation unit 51, the control unit 50 controls the driving unit 272 to move the condenser lens 27 so that the focal position is input. Even if the focusing position is changed by moving the focusing lens 27, the focusing diameter d does not change.

  Next, the operation of the variable BPP product 31 will be described with reference to FIGS. From Expressions (1) and (2), the light collection diameter d and the Rayleigh length Zr change with BPP. It is assumed that the beam diameter D1 shown in FIGS. 8A and 8B is the maximum diameter allowable by the condenser lens 27. It is assumed that the control unit 50 controls the variable BPP product 31 so that the BPP in FIG. 8A is smaller than the BPP in FIG. 8B.

  When the BPP is changed by the BPP product variable device 31, the divergence angle of the beam increases. Therefore, in order to make the beam diameter D common to the beam diameter D1, it is necessary to make the positions of the convex lens 28 and the concave lens 30 different. The positions of the convex lens 28 and the concave lens 30 are different between FIG. 8A and FIG. 8B because the beam diameter D is common to the beam diameter D1 while changing the BPP.

  By making the BPP in FIG. 8A smaller than the BPP in FIG. 8B by the BPP product variable device 31, the condensing diameter d in FIG. 8A is made smaller than the condensing diameter d in FIG. 8B. Can also be reduced. Assuming that the focused diameter d in FIG. 8A is d1 and the focused diameter d in FIG. 8B is d2, d1 <d2.

  It is assumed that the beam diameter D2 shown in FIGS. 8C and 8D is the minimum diameter allowable for the condenser lens 27. The minimum diameter is determined by the influence of the thermal lens and the light resistance of the coating of the condenser lens 27. It is assumed that the control unit 50 controls the variable BPP product device 31 so that the BPP in FIG. 8D becomes larger than the BPP in FIG. 8C.

  Similarly, the positions of the convex lens 28 and the concave lens 30 are different between FIG. 8C and FIG. 8D because the beam diameter D is common to the beam diameter D2 while changing the BPP. .

  By making the BPP in FIG. 8D larger than the BPP in FIG. 8C by the BPP product variable device 31, the condensing diameter d in FIG. 8D is made larger than the condensing diameter d in FIG. Can also be increased. Assuming that the focused diameter d in FIG. 8C is d3 and the focused diameter d in FIG. 8D is d4, d3 <d4.

  The control unit 50 controls the BPP product variable device 31 so that the BPP becomes a predetermined value, and drives 282 and 302 to determine the positions of the convex lens 28 and the concave lens 30 so that the desired beam diameter D is obtained. May be controlled.

  Since the laser beam machine 100 of the present embodiment includes the variable BPP product 31 and the variable beam diameter device 32, the condensing diameter d can be varied only by the variable BPP product 31 and only the variable beam diameter device 32 can be used. Thus, the light collecting diameter d can be changed. Further, the condensing diameter d can be made different between both the BPP product variable device 31 and the beam diameter variable device 32.

  As shown in FIGS. 8A to 8D, it is assumed that the beam diameter D changes in a range from the maximum beam diameter D1 to the minimum beam diameter D2. It is assumed that the value of BPP changes in the range from BPP1 to BPP2 by the BPP product variable device 31. 8 (a) and 8 (c), the value of BPP is BPP1, and in FIGS. 8 (b) and 8 (d), the value of BPP is BPP2.

  In this case, if the value of BPP is fixed at BPP1, the light collection diameter d changes in the range from d1 to d3, and if the value of BPP is fixed at BPP2, the light collection diameter d is between d2 and d4. Varies with range. In the laser beam machine 100 of the present embodiment, the converging diameter d can be changed in the range from d1 to d4 by changing the BPP.

  By changing at least one of the BPP and the beam diameter D, the condensing diameter d can be changed. By changing both the BPP and the beam diameter D, the converging diameter d can be changed over a wide range.

  According to the laser beam machine 100 of the present embodiment, since the converging diameter d can be adjusted over a wide range with the variable BPP product 31 and the variable beam diameter device 32, the range of the plate thickness that can be appropriately cut and processed. Can be expanded.

  If the variable range of the BPP by the variable BPP product device 31 is 1.5 to 5 mm · mrad (that is, 1 to 3.33 times) and the variable range of the beam diameter D by the beam diameter variable device 32 is 1 to 3 times, According to the equation (1), the condensing diameter d can be varied 1 to 10 times. If the variable range of the BPP is further increased, the condensing diameter d can be varied over a wider range.

  According to the laser beam machine 100 of the present embodiment, any one of a Gaussian shape and a ring shape can be selected as the beam shape.

  According to the laser beam machine 100 of the present embodiment, the beam waist is adjusted according to the thickness and the material of the plate material W1, and the BPP is adjusted accordingly, so that the distribution of the power density of the laser beam applied to the plate material W1 is appropriately adjusted. Can be controlled. According to the laser beam machine 100 of the present embodiment, by appropriately controlling the distribution of the beam waist and the power density and appropriately adjusting the melting time and the cutting speed of the plate W1, the cut surface roughness of the plate W1 is improved. Can be

  According to the laser beam machine 100 of the present embodiment, the focused diameter d and the focal position can be adjusted independently of each other. When it is not necessary to change the focal position, the position of the condenser lens 27 may be fixed, and only the convex lens 28 and the concave lens 30 may be configured to be movable.

  The control unit 50 may continuously adjust the condensing diameter d according to the plate thickness of the plate material W1. For example, a thick plate having a thickness of 6 mm to 30 mm and a plate material having a thickness of 0.1 mm to 6 mm may be thinned. The light collecting diameter d may be adjusted in two stages. Furthermore, the thickness of a plate having a thickness of 12 mm to 30 mm, the middle thickness of a plate having a thickness of 2 mm to 12 mm, and the thickness of a plate of 0.1 mm to 2 mm may be divided into thin plates, and the focusing diameter d may be adjusted in three stages. The control unit 50 may divide the plate thickness of the plate material W1 into four or more groups and adjust the light collection diameter d in four or more stages.

  Since the laser beam processing machine 100 of the present embodiment can adjust the converging diameter d, the plate material W1 having a plate thickness in a predetermined range can be adjusted to each plate thickness without replacing components such as a lens. It can be cut properly.

  According to the laser beam machine 100 of the present embodiment, the first lens (convex lens 28) having a positive focal length, the second lens (concave lens 30) having a negative focal length, and the positive lens have a positive focal length. What is necessary is just to use three lenses with the 3rd lens (condensing lens 27). Therefore, a laser processing machine that can simplify the configuration compared to the configuration described in Patent Literature 1 and that can cut a plate material having a predetermined range of plate thickness without replacing component parts can be realized at low cost. it can.

  According to the laser beam machine 100 of the present embodiment, by appropriately configuring at least the first and second lenses so as to be movable, it is possible to realize an appropriate cutting process according to the plate thickness.

  The present invention is not limited to the embodiment described above, and can be variously modified without departing from the gist of the present invention.

Reference Signs List 11 laser oscillator 15 laser processing unit 27 condenser lens (third lens)
28 convex lens (first lens)
30 concave lens (second lens)
31 Beam parameter product variable device (BPP product variable device)
32 beam diameter variable device 100 laser beam machine 122e emission end W1 plate

Claims (7)

A beam parameter product variable device for changing a beam parameter product of a laser beam emitted from a laser oscillator,
A beam diameter variable device that varies the beam diameter of the laser light emitted from the beam parameter product variable device,
A third lens that has a positive focal length, focuses the laser light emitted from the beam diameter variable device, and irradiates the plate with the laser light;
With
The beam diameter variable device,
A first lens that is movable in the optical axis direction, has a positive focal length, and converts divergent light of the laser light emitted from the emission end of the laser light into convergent light;
A second lens that is movable in the optical axis direction, has a negative focal length, and receives the convergent light;
Has,
The second lens has the same focal length as the second lens from the position where the convergent light is converged to the first lens side, corresponding to the position of the first lens in the optical axis direction. It is arranged at a position shifted by a distance, and is configured to convert the convergent light into parallel light,
The beam diameter of the parallel light emitted from the second lens is D, the beam parameter product of the laser light set by the beam parameter product variable device is BPP, the focal length of the third lens is f, and the third lens is When the focusing diameter of the laser light focused by the lens is d,
In order to obtain the target beam diameter D and the converging diameter d satisfying the expression (1),
The apparatus further includes a control unit that controls the beam parameter product variable device to set BPP to a predetermined value and determines the positions of the first and second lenses.
Les over The processing machine. A first moving mechanism for moving the first lens;
A second moving mechanism for moving the second lens;
A first driving unit that drives the first moving mechanism;
A second driving unit that drives the second moving mechanism;
Further comprising
Wherein the control unit, so as to move the first and second lens according to the processing conditions of the plate, that controls the first and second drive unit
Laser processing machine according to 請 Motomeko 1. The control unit increases the beam diameter D of the laser beam incident on the third lens so that the converging diameter d decreases as the plate thickness of the plate material decreases, and increases as the plate thickness of the plate material increases. 3. The laser beam machine according to claim 2 , wherein the first and second driving units are controlled so as to reduce the beam diameter D of the laser light incident on the third lens so as to increase the light diameter d . 4. The focus position of the laser light emitted from the third lens and focused on the plate material is constant even when the first and second driving units move the first and second lenses. 4. The laser beam machine according to 3. The third lens is movable in the optical axis direction, the laser processing machine according to 請 Motomeko 1 that is configured to change the focal position of the laser beam. A first moving mechanism for moving the first lens;
A second moving mechanism for moving the second lens;
A third moving mechanism for moving the third lens;
A first driving unit that drives the first moving mechanism;
A second driving unit that drives the second moving mechanism;
A third driving unit that drives the third moving mechanism;
Further comprising
The control unit is configured to move the first lens, the second lens, and the third lens according to processing conditions of the plate material, the first driving unit, the second driving unit and that controls the third driving unit
Laser processing machine according to 請 Motomeko 5. The control unit increases the beam diameter D of the laser beam incident on the third lens so that the converging diameter d decreases as the plate thickness of the plate material decreases, and increases as the plate thickness of the plate material increases. 7. The laser beam machine according to claim 6, wherein the first and second driving units are controlled so as to reduce the beam diameter D of the laser light incident on the third lens so as to increase the light diameter d .