JPS59127990A - Laser cutting device - Google Patents

Abstract

PURPOSE:To make cutting width smallest, cutting speed large, working accuracy high and efficiency better in laser cutting by making the polarization direction and cutting direction of laser light coincident with each other by the cooperation of the parallel movement and turning movement of a work. CONSTITUTION:The width of a working groove is smallest and an accelerating speed is highest when the advancing direction of a laser beam 1 with respect to a material 3 to be marked coincides with the polarization direction of the beam. The above are opposite when the laser beam scans in the direction at a right angle to the polarization direction. The horizontal two-dimensional movement and turning movement are given on the material 3 by a computer operation so as to make the cutting direction always coincident with the polarization direction of the beam 1, whereby the cutting width is stabilized at the smallest width, the working accuracy is improved and the working speed is made always highest.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a laser cutting device that can effectively convert laser energy into cutting energy.

Conventional configuration and problems The waves of CO2 and YAG laser beams are a type of electromagnetic waves, and the laser beams travel while vibrating in a direction perpendicular to the direction of travel. The direction of vibration perpendicular to the direction of travel of the laser beam is called the polarization direction, and the polarization direction can be used for circularly polarized laser beams that rotate in the same direction with the same amplitude over time, or for circularly polarized laser beams whose polarization direction is only in a certain direction over time. There are linearly polarized laser beams that have a fixed component of . Whether the laser beam is circularly polarized or linearly polarized can be selected depending on the configuration of the laser oscillator and the configuration of an external optical system that modulates the polarization direction of the laser beam after it exits the laser oscillator.

It has been found that by changing the direction of movement of the cutting with respect to the linear polarization direction of a conventional laser beam, the cutting effect can be significantly different. FIG. 1 is a diagram schematically showing how the cutting situation differs depending on the direction of movement of the cutting, and the laser beam 1 is linearly polarized in the OX direction. A condenser lens 2 focuses a laser beam onto the surface of the workpiece 3 for cutting. The polarization direction is maintained in the OX direction even after passing through the condenser lens 2, and when the workpiece 3 is moved in the OX direction to be cut, the absorption of the laser beam is high;
Therefore, the laser energy is efficiently converted into cutting energy, the cutting speed is fast, and the cutting width is narrow. - When cutting the stress relief workpiece 3 by moving in the OY direction, the absorption of the laser beam is low, and the absorption of the laser beam is in the cutting direction O
Since this mainly occurs on the cutting plane perpendicular to Y, the kerf width of the workpiece is wide and the cutting speed is slow.

When the cutting direction is equal (Ox direction) and perpendicular to the direction of linear polarization of the laser beam (Ox direction), the cutting speed V (m/m1n) and the cutting kerf width W are determined for each plate thickness. (mm) is shown in FIG.

As shown in Figure 2, when cutting in the Ox direction, which is the same direction as the linear polarization direction, the cutting speed is about 2 times faster than when cutting in the OY direction, which is perpendicular to the linear polarization direction.
twice, the kerf width will be approximately 2.

Next, a case will be described in which a circularly polarized laser beam is used.

FIG. 3 shows a conventional example of a laser cutting device used to cut a workpiece with a laser beam that is circularly polarized in a direction perpendicular to the direction of travel of the laser beam and has an isodirectional cutting ability.

In the figure, 1 is a circularly polarized laser beam, which is focused by a condenser lens 2 and directed to a workpiece 3 placed on a second table 12.
The beam is focused on processing point 4.

Reference numeral 13 denotes a base, which is configured to convert the rotational torque of the drive motor 5 into translational motion by a feed screw 6, which is a transmission mechanism, and to move the first table 8 in the Y direction on a slide rail 7. .

Similarly, the rotational torque of the drive motor 9 is converted into translational motion by the feed screw 10, which is a transmission mechanism, and the workpiece 3 is moved by moving the second table 12 in the X direction on the slide rail 11. Any processing point 4 on the object 3 can be brought to the laser beam irradiation position. However, in order to cut a workpiece into an arbitrary shape with the above circularly polarized laser beam, the laser beam must be circularly polarized using a laser oscillator and an external optical system, which increases the cost of the laser oscillator. Maintenance procedures are required to prevent deterioration of parts of the external optical system. When cutting with a circularly polarized laser beam, both the cutting speed and the kerf width are almost intermediate between the cases where the cutting direction is parallel to the polarization direction shown in Figure 2 and the case where the cutting direction is perpendicular. Compared to the case of cutting parallel to the polarization direction of 51.--, the width is '/1.5 times, the kerf width is 1.5 times as large, and the cutting efficiency and precision are not good.

OBJECTS OF THE INVENTION An object of the present invention is to eliminate the above-mentioned conventional drawbacks and to provide a laser cutting device that has high cutting speed, high efficiency, narrow kerf width, and high precision.

Structure of the Invention The present invention achieves the above-mentioned object, and when performing laser cutting using a linearly polarized laser beam, the workpiece is cut in parallel and parallel to the direction of the linearly polarized laser beam. A laser cutting device is provided which includes means for rotationally moving the laser cutting device.

Description of examples An embodiment of the laser cutting device of the present invention is shown in FIG.

In this embodiment, a laser beam 21 linearly polarized, for example, in the Ox direction is focused by a condenser lens 2, and the workpiece 3 is
6... so that the upper processing point 4 is irradiated, and the workpiece 3 is placed on the first table 8. in the OX and OY directions. In addition to being movable by the second table 12, the drive device is structured to rotate the workpiece so that the tangential direction of the processed shape of the workpiece is always in the direction of linearly polarized light.

The first table 8 is movable in the OY direction by a drive motor 5 via a feed screw 6, and the second table 12 is movable by a drive motor 9 via a feed screw 6.
0 on the slide rail 11 in the Ox direction. The cutting drive motor 15 generates rotational torque to rotate the workpiece 3, and rotates the third table 14 by means of a transmission mechanism, for example, a belt 16, thereby changing the cutting shape of the workpiece 3 placed thereon. The driving structure is such that the polarization direction matches that of the cut shape, and the signal to be input to the rotation motor 15 may be obtained by determining the tangential direction of the processing point from the cutting shape in advance and inputting the necessary rotation angle.
Alternatively, the tangential direction of the processing point may be automatically determined from the cutting shape, and the necessary rotation angle input may be automatically provided.

7, --7 Now, the process of cutting the figure P will be explained using FIG. The polarization direction of the laser beam is set to the oy force direction, and the fourth
Move the first and second table pullers 8 and 12 in the figure to adjust the beam to the state shown in FIG. 5A. In the figure, the solid line is the cut part,
The dotted lines indicate the uncut portions, but since the third table 14 in FIG. This is iX facing the direction. On the other hand, in steps C and 2, it is necessary to constantly rotate the third table 14 so that the polarization direction and the cutting direction match.

FIG. 6 is an example of a flowchart for commanding the rotation angle to be given to the drive motor 15 of FIG.

61 is a block for inputting processing figures, and is a paper tape.

Input using magnetic tape, card, etc. 52 is a block for reading out the processing point, and 53 calculates the amount of translational movement so that the processing point comes to the focused spot point of the laser. Block 64 indicates the amount of translational movement. Block 55 judges whether the cutting point is on a straight line or a curved line. If it is on a straight line, block 66 divides the rotation angle of the turntable, and if it is on a curved line, it is divided by the rotation angle of the turntable. block 67
Calculate the rotation angle of the turntable from the tangent to the figure, and then proceed to block 6.
8 indicates the rotation angle to be given to the rotary motor.

In this way, no matter what shape is being processed, cutting can be performed while always matching the cutting direction with the direction of the linearly polarized light.

Effects of the Invention In short, the present invention uses a linearly polarized laser beam,
It is constructed so that the direction of linearly polarized light and the cutting direction always match by means of parallel and rotational movement of the workpiece, and there are no parts or maintenance procedures for circularly polarized light. It has the advantage that it can reduce the laser cutting speed, increase the cutting efficiency, and narrow the kerf width to perform highly accurate processing.

[Brief explanation of drawings]

Figure 1 shows conventional cutting using a linearly polarized laser 91.-
Fig. 2 is a diagram showing the relationship between plate thickness, cutting speed, and cutting kerf width when using the laser in Fig. 1, and Fig. 3 is a diagram showing the relationship between the plate thickness, cutting speed, and cutting kerf width when using the laser in Fig. 1. FIG. 4 is a perspective view of a laser cutting device as an embodiment of the present invention, FIG. 5 is a diagram explaining the cutting process of the laser cutting device of the present invention, and FIG. It is a block diagram for calculating the amount of rotation given to the third table during cutting in the laser cutting device. 1.21 ・Laser beam, 2 ・Condensing lens, 3
- Workpiece, 5,9.15 Drive motor, 6.1o
...-Feed screw, 7.11 Slide rail, 8
1st table, 12 2nd table, 13 - base,
14-Third table, 16...-Belt. Name of agent: Patent attorney Toshio Nakao and 1 other person-4
ε

Claims (1)

[Claims] The machine comprises means for generating a linearly polarized laser beam, and means for moving the workpiece in parallel and rotation, and is configured so that the direction of the linearly polarized light of the laser beam and the cutting direction are controlled to always match. A laser cutting device characterized by: