Laser processing device and laser processing method

Abstract

Accelerates workpiece processing. [Solution] The laser processing device 10 comprises a laser head 11 having a nozzle 17 with an orifice 17b that ejects a liquid column 41 along a liquid column axis 1, a laser optical system 14 that focuses the laser on the orifice 17b, and a tip surface 13g, and a first gas nozzle 37 arranged on the edge of the laser head 11, the first gas nozzle 37 having a first orifice 37a that is inclined from the tip surface 13g toward the tip and is arranged so that the ejection axis 37b does not intersect with the liquid column axis 1.

Description

[Technical Field]

[0001] The present invention relates to a laser processing apparatus and a laser processing method. [Background technology]

[0002] A laser processing apparatus that generates a liquid jet that guides a laser beam therein is known (for example, European Patent No. 3105043, hereinafter referred to as Patent Document 1). The laser processing apparatus has a laser oscillator, a nozzle module, an optical element, and an air jet module. The air jet module has an inner wall and an outer wall. The inner wall forms a first passage through which the liquid jet passes. The inner wall and the outer wall form a second passage surrounding the first passage. Summary of the Invention [Problem to be solved by the invention]

[0003] In conventional laser processing devices, when processing a workpiece, the laser processing may be hindered by a liquid column that forms after colliding with the workpiece. The present invention aims to facilitate the machining of a workpiece. [Means for solving the problem]

[0004] A first aspect of the present invention is A laser head, a nozzle having an ejection port and ejecting a liquid column along a liquid column axis; a laser optical system that focuses a laser onto the nozzle; The tip surface and a laser head having a first gas nozzle disposed on an edge portion of the laser head, the first gas nozzle having a first nozzle orifice inclined from the tip surface toward the tip so that an ejection axis does not intersect with the axis of the liquid column; The laser processing device has the following features.

[0005] A second aspect of the present invention is The nozzle ejects a column of liquid, Bring the laser head close to the workpiece, A first gas nozzle injects gas simultaneously onto the surface of the workpiece and the tip face of the laser head, in the direction of the liquid column and the twist, to clean the liquid adhering to the tip face and the surface of the workpiece, After the first gas nozzle stops spraying the gas, a laser is guided into the liquid column to process the workpiece. This is a laser processing method.

[0006] While the workpiece is being machined, the second gas nozzle may inject gas toward the workpiece to clean off any liquid adhering to the surface of the workpiece.

[0007] The laser processing device may have a laser source. The laser source may have a laser oscillator, an optical lens, and an attenuator. The laser optical system may have an optical lens and an aperture. The gas is, for example, compressed air or helium gas. The processing point is a position on the workpiece where laser processing is performed, such as a hole processing position, a cutting position, a groove processing position, a cutting start position, or a groove processing start position. [Effects of the Invention]

[0008] According to the present invention, the machining of the workpiece can be facilitated. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a longitudinal sectional view of a laser processing apparatus according to an embodiment of the present invention; [Figure 2] Arrow II view of Figure 1 [Figure 3] 1 is a flowchart showing a laser processing method according to an embodiment; [Figure 4] Vertical cross section of laser processing equipment when in use [Figure 5] Vertical cross section of laser processing equipment when in use DETAILED DESCRIPTION OF THE INVENTION

[0010] As shown in Fig. 1, a laser processing apparatus 10 of this embodiment has a laser oscillator 31, a pump 33, a gas source 35, and a laser head 11. The laser head 11 has a head body 13, an optical lens (laser optical system) 14, a window 15, a nozzle 17, a packing 18, and a cap 19. Fig. 1 is a cross-sectional view taken along line II in Fig. 2. The laser head 11 has a central axis (liquid column axis) 1 and a liquid column discharge port 22. The side of the laser head 11 facing the liquid column discharge port 22 along the central axis 1 is the tip end. The side opposite the tip end is the base end.

[0011] The laser oscillator 31 oscillates a laser, which is preferably a pulsed laser. The pump 33 is, for example, a piston pump. The pump 33 is a liquid pump. The pump 33 pressurizes the liquid to 10 MPa to several tens of MPa. The liquid is, for example, water. The gas source 35 is an air compressor or a gas cylinder. The gas source 35 supplies compressed air or helium gas to the laser head. The laser oscillator 31, the pump 33, and the gas source 35 may be disposed outside the laser processing apparatus 10.

[0012] The head body 13 is columnar. The head body 13 has, in order from the base end, a laser passage 13a, a window chamber 13b, a liquid supply chamber 16, a nozzle chamber 13c, a cap chamber 13d, and an end surface (tip surface) 13g. The laser passage 13a, the window chamber 13b, the liquid supply chamber 16, the nozzle chamber 13c, and the cap chamber 13d are arranged along the central axis 1. The laser passage 13a is a right circular truncated cone. The window chamber 13b and the nozzle chamber 13c are right circular cylindrical. The nozzle chamber 13c may have a packing groove (not shown). The liquid supply chamber 16 has a U-shaped cross section and is a body of revolution centered on the central axis 1. The cap chamber 13d is right circular cylindrical and has a female thread 13f. The female thread 13f is arranged at the tip of the cap chamber 13d.

[0013] Nozzle 17 is disposed in nozzle chamber 13c. Nozzle 17 has a nozzle tip 17a and a liquid column formation chamber 17c. Nozzle tip 17a is, for example, a jewel. Hereinafter, jewel includes artificial jewels and sintered bodies of artificial jewels. Nozzle tip 17a has an orifice 17b. Orifice 17b extends along central axis 1. Liquid column formation chamber 17c is disposed along central axis 1. Liquid column formation chamber 17c is bullet-shaped.

[0014] The packing 18 is disposed in a packing groove (not shown) and seals the gap between the head body 13 and the nozzle 17.

[0015] The window 15 is disposed in the window chamber 13b. The window 15 is a right circular cylinder. The window 15 is, for example, a jewel plate. The laser passes through the window 15. The laser is focused onto the nozzle hole 17b by the optical lens 14. The optical lens 14 may include multiple lenses.

[0016] The cap 19 is fastened to the cap chamber 13d. The cap 19 has a right circular cylindrical shape. The cap 19 holds the nozzle 17. The cap 19 has a first surface 19f, a second surface 19g, a male thread 19b, a nozzle chamber 19d, a first gas inlet passage 20, an outlet pipe 21, a liquid column discharge port 22, a second gas inlet passage 24, a recess 25, and a gas outlet 26.

[0017] The first surface 19f and the second surface 19g are flat surfaces. The first surface 19f and the second surface 19g are end surfaces of the cap 19. The first surface 19f abuts against the bottom surface of the cap chamber 13d. The second surface 19g is substantially flush with the end surface 13g. The male thread 19b is disposed at the tip of the cap 19. The male thread 19b fits into the female thread 13f.

[0018] The recess 25 is disposed on the second surface 19g. The recess 25 has a shape of a right circular truncated cone centered on the central axis 1. The recess 25 has a diameter that decreases toward the first surface 19f.

[0019] The nozzle chamber 19d is disposed so as to open to the first surface 19f. The nozzle chamber 19d is a right cylinder centered on the central axis 1. The tip portion of the nozzle 17 is housed in the nozzle chamber 19d. The nozzle chamber 19d abuts against the nozzle 17.

[0020] 1, the first gas introduction passage 20 includes a first dispersion chamber 20a, a plurality of first connection pipes 20b, and a collection chamber 20c. The first gas introduction passage 20 is disposed on the first surface 19f. The first gas introduction passage 20 may be open to the first surface 19f. The first dispersion chamber 20a is hollow and disk-shaped. The collecting chamber 20c is also hollow and disk-shaped. The outer diameter of the collecting chamber 20c is smaller than the inner diameter of the first dispersion chamber 20a. The collecting chamber 20c is disposed radially inward of the first dispersion chamber 20a. Each of the first connecting pipes 20b connects the first dispersion chamber 20a to the collecting chamber 20c, and extends radially from the collecting chamber 20c.

[0021] The outlet pipe 21 and the liquid column discharge port 22 are arranged on the central axis 1. The outlet pipe 21 is a hollow cylinder. The outlet pipe 21 extends from the upper surface of the collecting chamber 20c toward the nozzle 17. The outlet pipe 21 is arranged inside the liquid column formation chamber 17c. The outlet pipe 21 protrudes in the proximal direction beyond the proximal edge of the collecting chamber 20c. The liquid column discharge port 22 is arranged on the bottom surface 25a. The liquid column discharge port 22 is a cylindrical hole, and communicates with the inner surface of the outlet pipe 21. The inner diameter of the liquid column discharge port 22 is the same as the inner diameter of the outlet pipe 21.

[0022] The second gas introduction path 24 has a second dispersion chamber 24a, a plurality of second connection pipes 24b, and a gas supply chamber 24c. The second gas introduction path 24 is arranged closer to the tip than the first gas introduction path 20. The second dispersion chamber 24a is thin-walled and cylindrical. The second dispersion chamber 24a is arranged radially outward from the first dispersion chamber 20a. The gas supply chamber 24c is hollow and disc-shaped. The gas supply chamber 24c is arranged closer to the tip than the collection chamber 20c. Each second connection pipe 24b connects the second dispersion chamber 24a and the gas supply chamber 24c. The second connection pipes 24b are arranged closer to the tip than the first connection pipes 20b. The second connection pipes 24b extend, for example, on a straight line passing through the central axis 1.

[0023] 1, a plurality of gas outlets 26 penetrate from gas supply chamber 24c toward bottom surface 25a. Gas outlets 26 extend parallel to central axis 1. As shown in FIG. 1, gas outlets 26 are cylindrical holes. Gas outlets 26 may be small-diameter holes.

[0024] The laser head 11 may be replaced with a known laser head (for example, Japanese Patent No. 5877432, Japanese Patent No. 5220914). Alternatively, the gas source 35 may include two types of gas sources (for example, a helium gas cylinder and a compressor). For example, the helium gas cylinder supplies helium gas to the first gas inlet passage 20 and the second gas inlet passage 24. The compressor supplies compressed air to the first nozzle 37 and the second nozzle 39.

[0025] As shown in Figures 1 and 2, the laser processing apparatus 10 further includes a moving device 28, a control device 30, a first nozzle (first gas nozzle) 37, a valve 38, a second nozzle (second gas nozzle) 39, and a valve 40.

[0026] The moving device 28 moves the laser head 11 in the up-down, left-right, and front-rear directions. The control device 30 includes, for example, a numerical control device. The control device 30 numerically controls the moving device 28. The control device 30 also controls the gas source 35, the pump 33, the laser oscillator 31, the valve 38, and the valve 40.

[0027] The first nozzle 37 is arranged around the laser head 11 at the tip of the laser head 11. A plurality of first nozzles 37 (four in FIG. 2) may be arranged. In this case, the first nozzles 37 are arranged rotationally symmetrically about the central axis 1. The first nozzle 37 has a first nozzle hole 37a. The first nozzle 37 injects gas along an injection axis 37b. The gas is, for example, compressed air.

[0028] 2, the first nozzle 37 is disposed so that the ejection axis 37b does not intersect with the central axis 1 when viewed from the direction of the central axis 1. The ejection axis 37b extends toward the periphery of the laser head 11. When viewed from the direction of the central axis 1, a distance 48 between the ejection axis 37b and the central axis 1 is 35 to 45% of a diameter 46 of the laser head 11. When viewed from the direction of the central axis 1, the ejection axis 37b may extend in a tangential direction of the laser head 11.

[0029] As shown in FIG. 1, when viewed from a direction perpendicular to the central axis 1 and the ejection axis 37b, the ejection axis 37b is inclined slightly toward the tip from the direction perpendicular to the central axis 1. The ejection axis 37b extends obliquely toward the workpiece 3. An angle 45 between the tip surface of the laser head 11 and the ejection axis 37b is 5 to 15 degrees. The first nozzle 37a ejects gas in a slightly diverging manner. The first nozzle 37a may eject gas in a solid conical shape. When the laser head 11 approaches the workpiece 3, the first nozzle 37a simultaneously cleans the tip of the laser head 11 and the surface 3a of the workpiece 3. When the first nozzle 37a ejects gas in a conical shape, the cone angle of the first nozzle 37a is approximately twice the angle 45.

[0030] The valve 38 is a solenoid valve. The valve 38 is disposed between the gas source 35 and the first nozzle 37. The valve 38 opens and closes the gas circuit to the first nozzle 37.

[0031] As shown in FIGS. 1 and 2, the second nozzle 39 is arranged around the laser head 11 at the tip of the laser head 11. A plurality of second nozzles 39 (three in FIG. 2) may be arranged. In this case, the second nozzles 39 are arranged rotationally symmetrically about the central axis 1. The second nozzle 39 has a second nozzle hole 39a. The second nozzle hole 39a injects gas parallel to the central axis 1.

[0032] The valve 40 is a solenoid valve. The valve 40 is disposed between the gas source 35 and the second nozzle 39. The valve 40 opens and closes the gas circuit to the second nozzle 39.

[0033] The laser processing method of this embodiment will be described with reference to Figure 3. In step S1, the nozzle 17 sprays a liquid column 41. In step S2, the moving device 28 moves the laser head 11 toward a processing point 50 (see Figure 4) on the workpiece 3. In step S3, the first nozzle 37 starts gas spray. In step S4, the first nozzle 37 stops gas spray. In step S5, the second nozzle 39 starts gas spray. In step S6, laser processing (e.g., drilling, cutting) is performed. After processing is completed, in step S7, the second nozzle 39 stops gas spray. In step S8, if there is a next processing point 50, the process returns to step S2. Otherwise, processing ends. Steps S3 and S4 may be performed simultaneously.

[0034] Each step will be explained in detail. As shown in FIG. 4, in step S1, the pump 33 supplies liquid to the liquid supply chamber 16. The liquid is ejected from the nozzle 17b as a liquid column 41. At this time, the gas source 35 sends gas from the first gas inlet path 20 to the liquid column formation chamber 17c. The gas flows toward the base end through the liquid column formation chamber 17c, heads toward the central axis 1 at the base end of the liquid column formation chamber 17c, turns toward the tip end, and flows into the outlet tube 21. The gas is ejected from the liquid column discharge port 22 as a gas flow 43, enveloping the liquid column 41. The gas source 35 also supplies gas through the second gas inlet path 24. The gas is ejected from the gas outlet 26. In step S2, the laser head 11 is positioned at the processing point 50. The laser head 11 approaches the surface 3a. The liquid column 41 spreads as a liquid mass 47 on the surface 3a.

[0035] As shown in FIG. 4, in step S3, the valve 38 opens and the first nozzle 37 blows on the surface 3a and the laser head 11. The gas jet from the first nozzle 37 cleans the liquid mass 47 and the tip surface of the laser head 11. The jet axis 37b is spaced from the central axis 1. This prevents the liquid column 41 from being disturbed by the gas jet from the first nozzle 37. The first nozzle 37 blows on the surface 3a, so that the liquid mass 47 on the surface 3a is almost completely removed. The first nozzle 37 also blows off droplets 53 adhering to the end surface 13g and the second surface 19g. The droplets 53 may contain dross. The first nozzle 37 cleans the droplets 53, thereby facilitating the cleaning of the end surface 13g and the second surface 19g. In step S4, the valve 38 closes and the injection from the first nozzle 37 stops.

[0036] 5, in step S5, the valve 40 opens and the second nozzle 39 blows gas onto the surface 3a. The gas ejected from the second nozzle 39 flows along the surface 3a, preventing a liquid mass 47 from forming near the processing point 50 on the surface 3a. Because the ejection axis 39b is parallel to the central axis 1, the gas flow from the second nozzle 39 is prevented from disturbing the liquid column 41.

[0037] As shown in FIG. 5, in step S6, the laser oscillator 31 guides a laser into the liquid column 41. The workpiece 3 is machined by the heat of the laser. As the machining progresses, part of the liquid column 41 collides with the machining point 50 and becomes a rebound liquid 49 that travels toward the laser head 11. The rebound liquid 49 contains dross. The rebound liquid 49 adheres to the recess 25, the end face 13g, and the second surface 19g, becoming droplets 53. The gas flow ejected from the gas ejection port 26 promotes the fragmentation and scattering of the rebound liquid 49. The gas jet from the gas ejection port 26 also promotes the ejection of the droplets 53 from the recess 25. By blowing the surface 3a with the second nozzle 39, the liquid mass 47 is not formed near the processing point 50, and the surface 3a is exposed, thereby facilitating laser processing.

[0038] After the laser processing is completed, step S7 is executed. In step S7, the valve 40 is closed and the jetting from the second nozzle 39 is stopped.

[0039] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present invention, and all technical matters included in the technical ideas described in the claims are subject to the present invention. The above-described embodiments are preferred examples, but a person skilled in the art can realize various alternatives, modifications, variations, or improvements from the contents disclosed in this specification, and these are included in the technical scope described in the appended claims. [Explanation of symbols]

[0040] 1 Center axis (liquid column axis) 3 Work 11 Laser Head 13g End face (tip face) 14 Optical lenses (laser optical systems) 37 First nozzle (first gas nozzle)

Claims

1. It is a laser head, A nozzle having a nozzle opening that discharges a liquid column along the axis of the liquid column, A laser optical system that focuses the laser onto the nozzle, The tip surface and, A laser head having, A first gas nozzle positioned at the edge of the laser head, having a first nozzle opening that is inclined toward the tip from the tip surface and positioned so that the injection axis does not intersect with the liquid column axis, A laser processing device having the following features.

2. The first gas nozzle ejects gas in a full cone shape, simultaneously cleaning the tip surface and the workpiece surface. The laser processing apparatus according to claim 1.

3. The injection axis is inclined 5 to 15 degrees toward the tip from the tip surface. The laser processing apparatus according to claim 1 or 2.

4. The system has a plurality of first gas nozzles arranged rotationally symmetrically with respect to the liquid column axis, The laser processing apparatus according to claim 1 or 2.

5. A second gas nozzle is positioned at the edge of the laser head, and further comprises a second gas nozzle having a second nozzle that extends parallel to the liquid column axis. The laser processing apparatus according to claim 1 or 2.

6. A control device, Before processing the workpiece, the gas is sprayed from the first gas nozzle toward the workpiece. The system further includes a control device that, after the first gas nozzle stops spraying, focuses the laser optical system onto the nozzle to process the workpiece. The laser processing apparatus according to claim 5.

7. The nozzle discharges a column of liquid, Bring the laser head close to the workpiece. The first gas nozzle sprays gas simultaneously onto the surface of the workpiece and the tip surface of the laser head, and in a twisting direction relative to the liquid column, to clean the liquid adhering to the tip surface and the surface of the workpiece. After the first gas nozzle stops injecting the gas, a laser is guided into the liquid column to process the workpiece. Laser processing method.

8. Furthermore, While the workpiece is being processed, the second gas nozzle sprays the gas toward the workpiece to clean any liquid adhering to its surface. The laser processing method according to claim 7.

9. The second gas nozzle injects the gas parallel to the liquid column. The laser processing method according to claim 8.

10. A laser head, A nozzle having a nozzle opening that discharges a liquid column along the axis of the liquid column, A laser optical system that focuses the laser onto the nozzle, A laser head having, A gas nozzle positioned at the edge of the laser head and having a nozzle that injects gas along an injection axis parallel to the liquid column axis, wherein the injected gas flows along the surface of the workpiece, suppressing the formation of liquid clumps near the processing point. A laser processing device having the following features.

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