JPH0839280A - Laser beam machining torch - Google Patents

Abstract

PURPOSE:To provide a laser beam machining torch where the adjusting work is easy, the misoperations an; reduced in number, the measurement using carbon dioxide gas laser (CO2 laser) of high output is dispensed with, the system is safe and the cost is reduced by preliminarily determining the focal position of the laser beam using the visible helium neon laser beam in a laser beam machine. CONSTITUTION:In a laser beam machining torch, a first lens holder 34 and a second lens holder 35 to preliminarily adjust the, focal distance are fitted to a condensing. The condensing is moved by the first and second lens holders 34, 35 to adjust the focal distance. The CO2 laser beam to be used in the machining is invisible light, and the focused laser beam can not be seen. Thus, the adjustment is achieved by using the visible helium neon laser beam. Because the deviation 52 to be caused from the difference between the focal position of the CO2 laser beam 50 and the focal position of the helium neon laser beam 51 is constant, the focal position of the CO2 laser beam can be obtained from the helium neon laser beam.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing torch of a laser processing machine for facilitating passage of laser light focused by a condenser lens through a processing nozzle.

[0002]

2. Description of the Related Art A conventional laser beam machine will be described below with reference to FIGS. (Description of FIG. 1) FIG. 1 is a configuration diagram of a laser processing machine.
In the figure, 1 is a laser oscillator, and 2 is a laser beam output from the laser oscillator. Reference numeral 3 denotes a bend mirror that reflects the laser light 2 and makes the laser light 2 incident on a condenser lens 6 described later. Reference numeral 4 is a central axis of a laser light guide tube 5 and a laser processing torch 9 which will be described later. Reference numeral 5 is a laser light guide tube for protecting the optical path of the laser light 2. A condenser lens 6 condenses the laser light 2. 7 is a laser beam condensed by the condenser lens 6, 8
Is a processing nozzle. Reference numeral 9 denotes a laser processing torch including the above-described condenser lens 6 and the processing nozzle 8. Also,
The work piece 20 is mounted on the processing table 22,
NC (Numerical Control), PLC (Programable Lo)
It moves under the control of the control device 21 such as a gic controller. Then, laser processing is performed by irradiating the workpiece 20 with the focused laser light 7 described above.

(Description of FIG. 2) FIG. 2 is a sectional view of the laser processing torch 9 of FIG. In the figure, the laser light 2 bent by the bend mirror 3 is guided to a laser processing torch 9 attached to a laser light guide tube 5. The laser processing torch 9 includes a lens holder 16 to which the condenser lens 6 is attached, a holder mount 17 that supports the lens holder 16, a holder 12 of the holder mount 17, a nozzle holder 11, a nozzle holder adjustment cylinder 11A, a processing nozzle 8 and the like. Has been done.

The holder mount 17 is constituted by push screws 13 and 14 attached to the holder 12 so as to move in a direction perpendicular to the central axis 4. The push screws 13 and 14 are also provided in the direction perpendicular to the plane of the paper (not shown), and are usually composed of four screws.

Reference numeral 40 denotes an inlet for supplying an assist gas from a gas supply source (not shown). Assist gas is a gas used for removing a material melted or sublimated by laser light in laser cutting. (Hereafter referred to as assist gas)

(Explanation of FIG. 3) FIG. 3 is an enlarged sectional view of a conventional processing nozzle 8. The processing nozzle 8 has a small nozzle hole 10 having a diameter of 1 mm to 2 mm, and the focused laser beam 7 passes through the small hole and is irradiated onto the workpiece 20. In laser cutting, the focused laser beam 7 and assist gas are sprayed from the nozzle hole 10. The workpiece 20 is heated to a high temperature by being irradiated with the laser beam and melted, and the molten material is blown off by the assist gas.

The processing nozzle 8 is constructed so as to move along the nozzle holder 11 about the central axis 4. The set nut 15 is for setting and fixing the positions of the nozzle holder 11 and the processing nozzle 8.

(Explanation of FIG. 4) FIG. 4 is a relational diagram between a conventional focused laser beam 7 and a processing nozzle 8. Central axis 4
The laser light 2 introduced along the line is condensed by the condensing lens 6, but since the focal length of the condensing lens 6 is set by machining, it usually has some deviation (error). . Therefore, it is necessary to perform adjustment so that the focus position 30 of the laser beam focused on the processing nozzle 8 comes to an appropriate position.

[0010] FIG. 4 (a), the focal position 30 of the focused laser beam is a normal Sette _Lee ing state is located outside approximately 1mm of the processing nozzle 8 (hereinafter, referred to as machining proper state). In this state, the vertically adjustable laser processing torch 9 is moved and adjusted so that the focus position of the focused laser light 7 comes to the surface of the workpiece 20.

FIG. 4B shows a state in which the focal position 30 of the focused laser beam 7 is located inside the processing nozzle 8.
In this case, the processing nozzle 8 is moved in the X direction along the nozzle holder 11 with the central axis 4 as the center so that the processing nozzle 8 approaches the condensing lens 6, and the focus position 30 is in the processing proper state. It is adjusted so that it is located about 1 mm outside the nozzle 8.

FIG. 4C shows a state in which the focus position 30 of the focused laser light is located outside the working nozzle 8 from the working proper state. In this case, the machining nozzle 8 is moved in the Y direction along the nozzle holder 11 with the central axis 4 as the center so that the machining nozzle 8 is away from the condenser lens 6, and the focus position 30 is the machining nozzle 8 in the proper machining state. Outside of about 1
Adjust so that it is located at mm.

In the proper working state, the outside of about 1 mm of the working nozzle 8 is 0 to 0 depending on the material of the work piece 20, the plate thickness and the like.
Between 5 mm, for example 0 mm, 0.5 mm, 1 mm, 1.
5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4
mm, 4.5 mm, 5 mm, and preferably between 0 and 2 mm, for example 1 mm, 1.5 mm, 2 mm
Is.

[0020]

In the laser processing, the high energy of the laser beam 2 is collected in a smaller area by using, for example, a condenser lens of a condenser system, and the workpiece 20 is instantaneously processed.
Is a processing method for evaporating, melting, etc. Therefore, it is important how high energy can be concentrated on the workpiece 20. For this reason, it is necessary to adjust the focal position 30 of the focused laser light 7 to be the surface of the work piece 20.

On the other hand, in the case of a carbon dioxide gas laser used for processing, the wavelength of light is in the infrared region, which is invisible light. Therefore, the laser light 2 and the focused laser light 7
Can't see. For this reason, as a method for adjusting the focal position 30 of the focused laser light 7, for example, a method shown in FIG. 5 described later is adopted.

FIG. 5 is a state diagram of a conventional focus position confirmation method. In the figure, the nozzle 8 or the nozzle holder 1
1 is removed and the inclined acrylic plate 31a is used as the condenser lens 6
Is a method of moving the acrylic plate 31a in the traveling direction 33 of the acrylic plate as shown in the figure and baking the condensed laser beam 7 on the acrylic plate 31a to form a trace on the surface. Focus position 30
Is indicated by the focus position 32 at the trace of the focused laser beam 7 which is the minimum width of the trace of the focused laser beam 7 as shown on the acrylic plate 31b. The position of this minimum width is measured by, for example, a ruler, and the focus position 30 is provided at a position approximately 1 mm outside the processing nozzle 8 in the proper processing state shown in FIG.
The position of the processing nozzle 8 is adjusted and determined so that However, this method has a problem that it is difficult for an amateur to understand because it takes time and depends on experience.

Therefore, an object of the present invention is to facilitate adjustment of the focal position 30 of the condenser lens 6 in the laser processing torch 9 of the laser processing machine, and to process the laser light 7 focused by the processing nozzle 8. It is to provide a structure of the laser processing torch 9 which is set at a normal position in a proper state.

[0040]

A laser beam machine according to the present invention comprises a condenser lens 6 for condensing a laser beam 2 outputted from a laser oscillator 1, and a laser beam condensed by this condenser lens 6 is provided. When irradiating the workpiece 20 with the light 7,
It is applied to a laser processing torch 9 of a laser processing machine that irradiates a focused laser beam 7 and jets an assist gas.

The features of the laser processing torch 9 described in claim 1 are, as shown in the sectional views of FIGS. 6 and 7, that the condenser lens 6 has a first lens holder 34 for adjusting the focal length in advance. A structure in which the second lens holder 35 is mounted, and the focusing lens 6 is moved along the central axis 4 of the lens holder 16 by the first lens holder 34 and the second lens holder 35 to adjust the focus position. Is a laser processing torch 9.

[0060]

FIG. 6 and FIG. 7 are a sectional view of a laser processing torch 9 and an enlarged sectional view of a focus position adjusting lens holder 16A of a condenser lens 6 showing an embodiment of the present invention, respectively.

FIG. 6 shows a sectional view of the laser processing torch 9 of the first aspect. This figure shows the conventional laser processing torch 9 of FIG.
Compared with the sectional view of FIG. 3, the joint between the nozzle holder 11 and the holder 12 has a simple structure, and there is no adjusting action of the machining nozzle 8 and the structure is simply screwed.

FIG. 7 shows an enlarged sectional view of the focus position adjusting lens holder 16A of the condenser lens 6 according to the first aspect. The focus position adjusting lens holder 16A includes, for example, a first lens holder 34 and a second lens holder 3 having the same central axis.
In order to adjust the deviation amount of the focal length, the first lens holder 34 to which the condenser lens 6 is fixed is arranged along the central axis 4 with respect to the second lens holder 35. The focus position can be adjusted by moving and finely adjusting and fixing the deviation amount of the focal length of the condenser lens 6. Here, 36 is a set screw for fixing the first lens holder 34 and the second lens holder 35 whose positions have been adjusted. The focus position adjusting lens holder 16A may have a double or more structure, for example, a triple structure or a quadruple structure, for easy and fine adjustment.

The focus position 30 of the condenser lens 6 is adjusted by, for example, visible light helium neon laser (HeNe laser).
Use to adjust. Carbon dioxide laser wavelength (10.6μ
Since m) is different from the wavelength (0.63 μm) of the helium neon laser, the refractive index of the condenser lens 6 is also different, and the focus position to be condensed is different. However, as shown in FIG. 8, the focused position of the focused carbon dioxide laser light 50 at the wavelength of the carbon dioxide laser (10.6 μm) and the focused helium neon laser light 51 at the wavelength of the helium neon laser (0.63 μm). Since the deviation amount 52 of the condensing position caused by the difference from the condensing position is constant, it is possible to determine the focal position 30 of the carbon dioxide laser from the helium neon laser using this deviation amount.

[0100]

In the laser processing machine of the present invention, the focus position 30 of the laser light after passing through the condenser lens 6 for condensing the laser light 2 output from the laser oscillator 1 is changed to a visible light helium neon laser. Since it is used and determined in advance, it is easy to prepare and determine it at a position, for example, about 1 mm outside the processing nozzle 8 in a proper processing state. Therefore, it is not necessary to repeatedly adjust, work time is shortened, and work mistakes are reduced. In addition, since adjustment is performed using a helium neon laser, it is safe because there is no need to measure the focus position using a high-power carbon dioxide laser. Further, since the structure of the laser processing torch 9 itself such as the nozzle holder 11, the holder 12, the processing nozzle 8 and the like is simplified, the cost is reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a laser processing machine.

FIG. 2 is a sectional view of a conventional laser processing torch.

FIG. 3 is an enlarged cross-sectional view of a conventional processing nozzle.

FIG. 4 is a relationship diagram between a conventional focused laser beam and a processing nozzle.

FIG. 5 is a state diagram of a conventional focus position confirmation method.

FIG. 6 is a sectional view showing a laser processing torch according to an embodiment of the present invention.

FIG. 7 is an enlarged cross-sectional view showing a focus position adjustment lens holder for a condenser lens according to an embodiment of the present invention.

FIG. 8 is a diagram showing a deviation amount of a focusing position caused by a difference between a wavelength of a carbon dioxide gas laser (10.6 μm) and a wavelength of a helium neon laser (0.63 μm).

[Explanation of symbols]

1 Laser Oscillator 2 Laser Light 3 Bend Mirror 4 Center Axis 5 Laser Light Guide Tube 6 Condensing Lens 7 Converged Laser Light 8 Processing Nozzle 9 Laser Processing Torch 10 Nozzle Hole 11 Nozzle Holder 11A Nozzle Holder Adjustment Tube 12 Holder 13 Push Screw 14 Push screw 15 Set nut 16 Lens holder 16A Focus position adjustment lens holder 17 Holder mount 20 Work piece 21 Control device 22 Processing table 30 Focus position 31a Acrylic plate 31b Acrylic plate 32 Focus position by focused laser beam trace 33 Scanning direction of acrylic plate 34 First lens holder of the present invention 35 Second lens holder of the present invention 36 Set screw 40 Assist gas introduction port 50 Converged carbon dioxide laser light 51 Concentrated helium neon laser light 52 Carbon dioxide laser and helicopter Deviation of the focusing position of the umneon laser

Claims (1)

[Claims] 1. A condenser lens for condensing laser light output from a laser oscillator, and the condensed laser light when irradiating a workpiece with the laser light condensed by the condenser lens. In a laser processing torch provided with a nozzle having a passage opening for irradiating the laser beam and for injecting an assist gas, the lens holder of the condenser lens has a dual structure deviation amount adjusting mechanism for adjusting the deviation amount of the focal length, A laser processing torch equipped with a focus position adjustment lens holder for finely adjusting and fixing the optical lens along the central axis of the lens holder.