WO1999058289A1

WO1999058289A1 - Laser beam machine

Info

Publication number: WO1999058289A1
Application number: PCT/JP1998/002102
Authority: WO
Inventors: Masaru Kanaoka; Tohru Murai; Yasuyuki Miyamoto
Original assignee: Mitsubishi Denki Kabushiki Kaisha
Priority date: 1998-05-13
Filing date: 1998-05-13
Publication date: 1999-11-18
Also published as: TW425322B

Abstract

A reflection laser beam diameter adjuster (9) is provided above a lateral frame (3) so that the distance from a machining head (5) to the adjuster (9) is shorter than 8 m. Thus, even when the beam is diverged after it passes the adjuster (9), the deviation of the focal position can be kept within 0.6 mm, whereby high quality machining can be achieved.

Description

Description Laser processing machine Technical field

The present invention relates to a laser beam machine, and more particularly, to a laser beam machine capable of reducing a positional deviation between a focal position of a laser beam and a surface of a workpiece. Background art

FIG. 9 is a perspective view showing a schematic configuration of a conventional laser beam machine. The laser beam machine 500 includes a rail 1 provided on both sides of the workpiece W, a traveling frame 2 traveling on the rail 1, and a transverse frame 3 provided between the traveling frames 2 on both sides. The traversing carriage 4 that moves along the traversing frame 3, the processing head 5 attached to the traversing carriage 4, the condenser lens 6 provided inside the processing head 5, and the processing head 5. Connected laser path 7, a plurality of bend mirrors 8 provided in the laser path, a reflective laser beam diameter adjuster 9 disposed at the entrance of the laser path, and a laser oscillator 11 for emitting laser light. And a control device 12 for controlling the positioning of the processing head 5 and controlling the operations of the anti-It laser beam diameter adjuster 9 and the laser oscillator 11. FIG. 10 is a perspective view showing the reflective laser beam diameter adjuster shown in FIG. The reflection laser beam diameter adjuster 9 has a reflection surface 92 on one surface of a cylindrical air jacket 91. The reflection surface 92 is made of an elastically deformable material. The air jacket 91 has an air inlet 93 and an air outlet 94. The air inlet 93 is connected to the pump 95. The air in the air jacket 91 is sucked by the pump 95. The air outlet 94 is provided with a valve (not shown) that regulates air flow. When the pressure inside the air jacket 91 is reduced, the reflecting surface 92 becomes a spherical surface. When air is released from the air outlet 94, the reflecting surface 92 returns to a flat surface.

Next, the operation of the laser beam machine 500 will be described. Laser oscillator 1 1 When the propagation distance from becomes large, take the beam waist in the optical path. This is to prevent the beam diameter from expanding. The laser beam R output from the laser oscillator 11 is collimated by the reflection type laser beam diameter adjuster 9. The collimated laser light R passes through the laser light path 7. The laser beam R is bent by the bend mirror 18 in the laser beam path 7. Next, the laser beam R is condensed by the condenser lens 6 and is irradiated on the surface of the workpiece W. Thereby, the workpiece W is cut.

In the conventional laser beam machine 500 described above, a reflection type laser beam diameter adjuster 9 is arranged near the laser oscillator 11, and the laser beam R is collimated by using the reflection type laser beam diameter adjuster 9. I have. However, since the laser beam R cannot be completely parallelized by the reflection type laser beam diameter adjuster 9, there is a small beam divergence angle. This beam divergence angle changes with the propagation distance of the laser light R. When the processing head 5 moves on the X and Y coordinates, the propagation distance of the laser beam R changes, so that the beam divergence angle changes and the beam incident angle on the condenser lens 6 changes. For this reason, there was a problem that the focus position was shifted and the cutting quality was lowered.

Accordingly, it is an object of the present invention to provide a laser beam machine capable of reducing a positional deviation between a focal position of a laser beam and a surface of a workpiece. Disclosure of the invention

In order to achieve the above object, a laser beam machine according to the present invention includes a laser oscillator that outputs laser light, and reflects and propagates laser light output from the laser oscillator, and changes a reflection surface curvature of an optical component. Laser type laser beam diameter adjusting means that adjusts the laser beam diameter by means of a laser beam, and the laser beam that has been adjusted is condensed by a condensing lens, and the condensed laser beam is irradiated onto the surface of the workpiece. In a laser processing machine having a head, a reflection type laser beam diameter adjusting means is arranged near a processing head. As a result of the research by the inventors, it has been found that when the distance from the processing head to the laser beam diameter adjusting means increases, the positional deviation between the focal position of the laser beam and the surface of the workpiece increases. Therefore, in this laser beam machine, the reflection type laser beam diameter adjusting means is used for machining. It was provided near the head. For this reason, the displacement between the focal position and the surface of the workpiece is reduced.

A laser processing machine according to the next invention comprises a laser oscillator for outputting a laser beam, and a reflection device for reflecting and propagating the laser beam output from the laser oscillator and adjusting a laser beam diameter by changing a reflection surface curvature of an optical component. A laser beam machine having a die laser beam diameter adjusting means and a machining head for focusing the adjusted laser beam by a condenser lens and irradiating the focused laser beam to the surface of the workpiece. The reflection type laser beam diameter adjusting means is arranged near the processing head so that the positional deviation of the focal position with respect to the workpiece falls within the processing limit.

If the reflection-type beam diameter adjusting means is far from the processing head, the positional deviation between the focal position and the surface of the workpiece increases. Therefore, the reflection-type laser beam diameter adjusting means is arranged near the processing head so that the positional deviation of the focal position with respect to the workpiece falls within the processing limit. In this way, the cutting quality is improved.

A laser processing machine according to the next invention comprises a laser oscillator for outputting a laser beam, and a reflection device for reflecting and propagating the laser beam output from the laser oscillator and adjusting a laser beam diameter by changing a reflection surface curvature of an optical component. A laser having a mold laser beam diameter adjusting means, and a processing head for condensing the adjusted laser beam with a condenser lens and irradiating the converged laser beam to the surface of the workpiece. In the processing machine, the reflection type laser beam diameter adjusting means is arranged near the processing head so that the positional deviation of the focal position with respect to the workpiece is 0.6 mm or less.

As a result of the study by the inventors, it has been found that when the displacement of the focal position with respect to the workpiece is 0.6 mm or less, good cutting quality can be obtained. Therefore, a reflection-type laser beam diameter adjusting means is arranged near the processing head so that the positional shift of the focal position with respect to the workpiece is 0.6 mm or less. In this way, the cutting quality is improved. A laser processing machine according to the next invention comprises a laser oscillator for outputting a laser beam, and a reflection device for reflecting and propagating the laser beam output from the laser oscillator and adjusting the laser beam diameter by changing a reflection surface curvature of an optical component. Mold laser beam diameter adjusting means and this adjustment Laser beam machine that has a processing head that collects laser light collected by a condenser lens and irradiates the collected laser light to the surface of the workpiece. The distance to the beam diameter adjusting means is set within 8 m.

As a result of the inventors' research, if the distance from the processing head to the laser beam diameter adjusting means is larger than 8 m, the displacement between the focal position of the laser beam and the surface of the workpiece becomes large, and the cutting quality deteriorates I found out. Therefore, in this laser processing machine, the reflection type laser beam diameter adjusting means is provided within 8 m from the processing head. For this reason, the positional deviation between the focal position and the workpiece surface is reduced.

The laser beam machine according to the next invention is the above-mentioned laser beam machine, wherein the laser beam output from the laser oscillator is transmitted and propagated and the curvature of the optical component is changed, instead of the reflection type laser beam diameter adjusting means. The transmission laser beam diameter adjusting means for adjusting the laser beam diameter is provided.

The same effect as described above can be obtained by using a transmission type laser beam diameter adjusting unit having the same function instead of the reflection type laser beam diameter adjusting unit. BRIEF DESCRIPTION OF THE FIGURES

[Brief description of the drawings]

FIG. 1 is a perspective view showing a laser processing machine according to a first embodiment of the present invention. FIG. 2 is an explanatory diagram showing a shift of a focal position with respect to a workpiece surface. Fig. 4 is a graph showing the relationship between the range of processing conditions for obtaining good cutting quality of mild steel material and the amount of deviation of the focal position.Fig. 4 shows the processing conditions for obtaining good cutting quality of stainless steel. FIG. 5 is a graph showing the relationship between the range and the amount of deviation of the focal position. FIG. 5 is an explanatory diagram showing an optical path from a laser oscillator to a processing head; and FIG. 6 is a reflection type from a processing head. FIG. 7 is a graph showing a relationship between a distance to a laser beam diameter adjuster and an amount of deviation of a focal position. FIG. 7 is a flowchart showing a process of adjusting a laser beam diameter. FIG. FIG. 3 is a schematic configuration diagram showing a laser processing machine according to Embodiment 2. Figure 9 is a perspective view showing a schematic configuration of a conventional laser beam machine, the FIG. 10 is a perspective view showing the reflection-type laser beam diameter adjuster shown in FIG. BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing a laser beam machine according to a first embodiment of the present invention. The laser beam machine 100 is provided with rails 1 provided on both sides of a workpiece W, and runs on the rails 1. Traveling frame 2, a traversing frame 3 provided between the traveling frames 2 on both sides, a traversing carriage 4 moving along the traversing frame 3, and a machining head attached to the traversing carriage 4. 5, a condenser lens 6 provided inside the processing head 5, a laser path 7 connected to the processing head 5, a plurality of bend mirrors 8 provided in the laser path 7, and a middle of the laser path 7. Then, the reflection type laser beam diameter adjuster 9 provided on the traversing frame 3, the bend mirror 10 provided at the entrance of the laser path 7, the laser oscillator 11 for emitting the laser light R, and the processing. Controls the position of the laser beam 5 and the reflective laser beam diameter adjuster 9 and And a control unit 1 2 for controlling the operation of the laser oscillator 1 1. The condenser lens 6 has a focal length of 7.5 in. The reflection type laser beam diameter adjuster 9 has the same embodiment as that shown in the conventional example (see FIG. 10).

The smaller the deviation of the focal position with respect to the surface of the workpiece W, the better the cutting quality. FIG. 2 is an explanatory diagram showing a deviation of a focal position F with respect to a workpiece surface S. The laser beam R that has entered the processing head 5 is condensed by the condenser lens 6. When the focal position F of the laser light R coincides with the workpiece surface S, the displacement ΔΖ becomes zero. FIG. 3 is a graph showing a relationship between a range of processing conditions for obtaining a good cutting quality of a mild steel material and a shift amount of a focal position. The case where ΔΖ = 0 mm, Z = 0.3 mm, and ΔΖ = 0.6 mm are described as the shift amount of the focal position F. The processing conditions include the cutting speed (mm / min) and the laser output (W). As the workpiece W, 3340: 00 having a thickness of 91: 1: 111 was used. Oxygen was used as the assist gas. For each displacement, the cut surface roughness is 100 / m or less and the dross height is 0.5 The processing condition range of not more than mm was experimentally determined. As a result, it was found that the smaller the amount of deviation of the focal position F, the wider the range of processing conditions.

FIG. 4 is a graph showing the relationship between the range of processing conditions at which good cutting quality of stainless steel can be obtained and the amount of deviation of the focal position. The horizontal axis indicates the assist gas pressure. The vertical axis indicates the dross height. As the shift amount of the focal position,

ΔΖ = 0.3 mm. ΔΖ = 0.6 mm. ΔΖ = 0.7 mm. As the workpiece W, SUS304 having a thickness of 12 mm was used. Nitrogen was used as the assist gas. As a result of the experiment under these conditions, when the deviation of the focal position F was 0.6 mm or less, the dross height was within 0.2 mm. From this, it was found that good cutting quality was obtained when the deviation of the focal position F was 0.6 mm or less.

From the above results, it was found that it is preferable that the deviation amount of the focal position F be 0.6 mm or less in order to improve the cutting quality.

FIG. 5 is an explanatory diagram showing an optical path from the laser oscillator 11 to the processing head 5. The reflection type laser beam diameter adjuster 9 is located near the processing head 5. The sum of the optical path a, the optical path b, and the optical path c is the optical path length from the reflective laser beam diameter adjuster 9 to the processing head 5.

FIG. 6 is a graph showing a relationship between a distance from a processing head to a reflective laser beam diameter adjuster and a shift amount of a focal position. The position of the reflection type laser beam diameter adjuster 9 was changed with reference to the position of the head 5, and the amount of deviation of the focal position F was measured. In the experiment, a laser beam machine with a PR mirror curvature of 10 m at the exit of the laser oscillator 11 was used. O The laser beam diameter was 20 mm, 30 mm, and 4 Omm. As a result, when the laser beam diameter is 40 mm and the distance from the reflective laser beam diameter adjuster 9 to the processing head 5 is within 8 m, the deviation of the focal position F is 0.6 mm. It was about. When the laser beam diameter was 20 mm and 3 Omm, the deviation of the focal position F was within 0.6. Thus, in order to obtain good cutting quality, the distance between the reflective laser beam diameter adjuster 9 and the processing head 5 should be at least 8 m, and preferably, the reflective laser beam diameter adjuster 9 should be mounted on the processing head 5. It was found that it was better to approach the vicinity of. Furthermore, as a result of experiments, if the distance from the reflective laser beam diameter adjuster 9 to the processing head 5 is within 8 m, mild steel material with a maximum thickness of 3 O mm, stainless steel with a maximum thickness of 18 mm, It was found that good cutting quality was obtained with an aluminum material with a maximum thickness of 16 mm.

From the above results, in the laser beam machine 100 of the present invention, the distance from the processing head 5 to the reflection type laser beam diameter adjuster 9 was set within 8 m. Specifically, the reflection type laser beam diameter adjuster 9 was provided on the traversing frame 3 so as to be located near the processing head 5. It should be noted that depending on the design of the laser beam machine 100, it is not always appropriate to set the length within 8 m. Therefore, the distance is set so that the deviation amount of the focal position F is within 0.6 mm. In this way, good processing quality can be obtained. Further, as a precondition for regulating the distance from the processing head 5 to the reflective laser beam diameter adjuster 9, the laser beam diameter is adjusted by the reflective laser beam diameter adjuster 9. Needs to be adjusted. FIG. 7 is a flowchart showing a process of adjusting the laser beam diameter. In step S701, information on a material and a thickness to be processed is input from outside. In step S702, the optimum beam diameter information is selected from the database of the controller 12 based on the input material and plate thickness. Alternatively, the beam diameter may be calculated. In step S703, the curvature of the reflective laser beam diameter adjuster 9 is calculated based on the information on the optimum beam diameter. In step S704, the reflecting surface 92 of the reflecting laser beam diameter adjuster 9 is changed to the calculated curvature.

After optimizing the beam diameter, the workpiece W is processed. First, select the piercing condition and execute piercing under this condition. Next, the cutting conditions are selected. When selecting the optimum beam diameter, the beam diameter should be used properly depending on whether cutting is performed by pulse or CW. The optimum beam diameter is feedback-controlled by the controller 12. Then, the laser beam machine 100 starts cutting the workpiece W under these cutting conditions. When piercing, select a beam diameter suitable for piercing, and when cutting, select a beam diameter suitable for cutting. You may do it.

FIG. 8 is an explanatory diagram showing an optical path of the laser beam machine according to the second embodiment of the present invention. The laser processing machine 200 according to the second embodiment is characterized in that a transmission type laser beam diameter adjuster 201 is used instead of the reflection type laser beam diameter adjuster. Other configurations are substantially the same as those of the laser beam machine 100 of the first embodiment. The same elements are denoted by the same reference numerals. The beam is made substantially parallel by installing a transmission type laser beam diameter adjuster 201 in the optical path. Also in this case, the distance from the processing head 5 to the transmission laser beam diameter adjuster 201 (the sum of the optical path d to the optical path f in the figure) is set within 8 m. Specifically, the reflection type laser beam diameter adjuster 201 is provided on the traversing frame 3 and is positioned near the processing head 5 (not shown). It should be noted that depending on the design of the laser beam machine 200, it is not always appropriate to be within 8 m. Therefore, the distance is set so that the deviation amount of the focal position F falls within 0.6 mm. The operation of the laser beam machine 200 is the same as that of the laser beam machine 100 of the first embodiment, and therefore the description is omitted. In this way, good processing quality can be obtained.

As described above, according to the laser beam machine of the present invention, the reflection type laser beam diameter adjusting means is provided near the processing head. Therefore, the displacement between the focal position and the surface of the workpiece is reduced, and the cutting quality is improved.

Next, according to the laser beam machine of the present invention, the reflection-type laser beam diameter adjusting means is arranged near the processing head until the positional deviation of the focal position with respect to the workpiece falls within the processing limit. . In this way, the cutting quality is improved.

Next, according to the laser beam machine of the present invention, the reflection type laser beam diameter adjusting means is arranged near the processing head so that the positional deviation of the focal position with respect to the workpiece becomes 0.6 mm or less. In this way, the cutting quality is improved.

Next, according to the laser beam machine of the present invention, the reflection type laser beam diameter adjusting means is provided within 8 m from the processing head. For this reason, the positional deviation between the focal position and the surface of the workpiece is reduced, and the cutting quality is improved.

Next, according to the laser beam machine of the present invention, the reflection type laser beam diameter adjusting means is replaced. In addition, since the transmission type laser beam diameter adjusting means having the same function is used, the cutting quality can be improved as described above. Industrial applications

As described above, according to the laser beam machine according to the present invention, it is useful for cutting a workpiece to improve the cutting quality, and the larger the size, the more effective.

Claims

The scope of the claims

1. A laser oscillator that outputs laser light,

A reflection type laser beam diameter adjusting means for reflecting and propagating the laser beam output from the laser oscillator and changing the reflection surface curvature of the optical component to adjust the laser beam diameter; and a condenser lens for collecting the adjusted laser beam. A processing head that irradiates the surface of the workpiece with the collected laser light.

In a laser processing machine having

A laser processing machine characterized in that a reflection type laser beam diameter adjusting means is arranged near a processing head.

2. In place of the reflection-type laser beam diameter adjusting unit, a transmission-type laser beam diameter adjusting unit that transmits and propagates a laser beam output from a laser oscillator and changes the curvature of an optical component to adjust the laser beam diameter is used. 2. The laser beam machine according to claim 1, wherein the laser beam machine is provided.

3. A laser oscillator for outputting a laser beam;

A reflection type laser beam diameter adjusting means for reflecting and propagating the laser beam output from the laser oscillator and adjusting the laser beam diameter by changing the reflection surface curvature of the optical component; and collecting the adjusted laser beam. A processing head that condenses the light with an optical lens and irradiates the condensed laser light onto the surface of the workpiece,

Laser processing machine with

A laser processing machine characterized in that a reflection type laser beam diameter adjusting means is arranged near a processing head so that a positional shift of a focal position with respect to a workpiece falls within a processing limit.

4. A laser output from a laser oscillator in place of the reflection type laser beam diameter adjusting means 4. The laser beam machine according to claim 3, further comprising a transmission type laser beam diameter adjusting means for transmitting and propagating light and changing the curvature of the optical component to adjust the laser beam diameter.

5. A laser oscillator that outputs laser light,

A reflection type laser beam diameter adjusting means for reflecting and propagating the laser beam output from the laser oscillator and changing the reflection surface curvature of the optical component to adjust the laser beam diameter; and collecting the adjusted laser beam by a condenser lens. In a laser processing machine having a processing head for irradiating a condensed laser beam onto the surface of a workpiece,

A laser processing machine characterized in that a reflection type laser beam diameter adjusting means is arranged near a processing head so that a deviation of a focal position from a workpiece is 0.6 mm or less.

6. In place of the reflection-type laser beam diameter adjustment means, a transmission-type laser beam diameter adjustment system that transmits and propagates laser light output from a laser oscillator and changes the curvature of optical components to adjust the laser beam diameter. 6. The laser beam machine according to claim 5, wherein a means is provided.

7. A laser oscillator for outputting laser light,

A reflection type laser beam diameter adjusting means for reflecting and propagating the laser beam output from the laser oscillator and changing the reflection surface curvature of the optical component to adjust the laser beam diameter; and collecting the adjusted laser beam. A processing head that condenses the light with an optical lens and irradiates the condensed laser light onto the surface of the workpiece,

In a laser processing machine having

A laser processing machine characterized in that the distance from the processing head to the reflection type laser beam diameter adjusting means is set within 8 m.

8. In place of the reflection type laser beam diameter adjusting means, a transmission type laser beam diameter adjustment which transmits and propagates a laser beam output from a laser oscillator and adjusts a laser beam diameter by changing a curvature of an optical component. 2. The laser beam machine according to claim 1, wherein means is provided.