JPH05277779A - Laser beam machine - Google Patents

Abstract

PURPOSE:To prevent the fluctuation in the condensing property of a laser beam with a change in optical path length and to improve the stability of laser beam processing by maintaining the optical path length of the laser beam from a laser oscillator up to a processing position at a specified distance. CONSTITUTION:This laser beam machine has an optical path length adjusting means 7 moving in such a manner as to maintain the specified optical path length until the laser beam 2 emitted form the laser oscillator 1 arrives at a processing head 6 disposed with a condenser lens 5. The device has an optical path length adjusting and computing device 17 for controlling the optical path length adjusting means 7 disposed with bend mirrors 5, 6 by measuring the moving quantity Lx in the X direction of a processing head 6 and the moving quantity Ly in the Y direction thereof with the detectors of servo motors for respective axes or detectors, etc., installed separately therefrom and making the computation (Lx+Ly)/2=Lu, then commanding the moving quantity Lu to drive the servo motors. Not only the directions X, Y but a direction Z may be taken into account to compute (Lx+Ly+Lz)/2=Lu at the time of calculating the moving quantity Lu.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus for irradiating a workpiece with a laser beam for processing.

[0002]

2. Description of the Related Art A conventional laser processing apparatus guides a laser beam emitted from a laser oscillator to a processing head provided with a condenser lens and irradiates the workpiece with the laser beam condensed by the condenser lens. It was done.

An example thereof is shown in FIG. In the figure, 1 is a laser oscillator, 2 is a laser beam, 3 and 4 are bend mirrors, 5 is a condenser lens, 6 is a processing head, 7 is a workpiece, 8 is a column, and the laser beam emitted from the laser oscillator 1 is shown. 2 is reflected by the bend mirrors 3 and 4 and guided to a condenser lens 5 installed in the processing head, and the workpiece 7 is processed by the laser light condensed by the condenser lens 5.

Next, the characteristics of processing by laser light will be described. As shown in FIG. 3, the laser light 2 is bent by the bend mirrors 3 and 4.
Is guided to the processing head 6, and the processing head 6 is moved by being controlled by an NC device or the like to perform processing in an arbitrary shape.
Since the distance from the laser oscillator 1 is different between the position and the position B and the laser light has a diffusion angle of about 2 mrad, the diameter of the laser light incident on the condenser lens 5 is different. The spot diameter and depth of focus of the laser light condensed by the optical lens 5 and the distance from the condensing lens to the minimum spot diameter are different, and it is very important to process under the same processing conditions at all positions on the processing table. It had the drawback of being difficult.

[0005]

In a processing apparatus in which the optical path length from the laser oscillator to the processing position is different, there is a case where processing cannot be performed under the same processing conditions due to a difference in light converging property. In particular, there has been a problem that as the plate thickness of the work piece becomes thicker, the width of the processing condition becomes narrower, and if a difference in light-collecting property occurs as described above, a processing defect is likely to occur.

[0006]

The present invention has been made in view of the above problems, and an optical path length adjusting means for adjusting an optical path length from a laser oscillator to a processing position is provided via an optical path length adjusting arithmetic unit. It is controlled so that the optical path length from the laser oscillator to the processing position can be processed at a constant distance.

[0007]

By controlling the optical path length adjusting means by the optical path length adjusting arithmetic unit, the optical path length from the laser oscillator to the processing position is always maintained at a constant distance, and fluctuations in the converging property of the laser light are prevented. The effect is to improve the stability of laser processing.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the embodiment shown in FIG.

Laser light 2 emitted from a laser oscillator 1
Is reflected by the bent mirrors 3 and 13 and guided to the optical path length adjusting means 11 equipped with the bent mirrors 9 and 10, and the laser light reflected by the bend mirrors 9 and 10 is processed with the bend mirror 12 arranged in the column 8. It is reflected by the bend mirror 4 arranged above the head 6, guided to the processing head 6 provided with the condenser lens 5, and irradiated with the laser beam condensed by the condenser lens 5 to the workpiece 7 for processing. Be seen.

The machining head 6 is controlled by an NC device or the like and is movable in the directions of arrows Y and Z in the figure, and the machining head 6 is installed in a column 8 which is movable in the direction of arrow X. Since it is present, it can also be moved in the direction of arrow X.

As described above, since it is movable in the directions of the arrows X and Y, it is possible to process the workpiece 7 in any shape and to follow the displacement in the direction of the arrow Z. The amount of change in the optical path length from the laser oscillator 1 caused by the movement of 6 in the directions of the arrows X and Y indicates the position of the optical path length adjusting means 11 and the optical path length adjusting arithmetic unit 17.
Cancel by controlling the servo motor 14 via
The laser processing apparatus is characterized in that the optical path length from the laser oscillator 1 is made constant.

FIG. 1 shows the control method of the optical path length adjusting means 11.
2 will be described.

When the machining head 6 moves in the X and Y directions, a moving amount Lx in the X direction and a moving amount Ly in the Y direction.
Is measured with a servomotor detector or a separate detector.

The optical path length adjustment calculation device 17 is provided with the moving amount Lx.
And Ly are input, the calculation of (Lx + Ly) / 2 = Lu is performed, and then the amount of movement Lu of the optical path length adjusting unit 11 is output.

However, Lx and Ly are the arrows X,
It has a positive value with respect to the amount of movement of Y in the + direction, and has a negative value with respect to the amount of movement in the − direction. Therefore, when the value of Lu is positive, the optical path length adjusting means 11 moves in the + direction of the arrow U, and when the value of Lu is negative, it moves in the-direction.

The movement amount Lu output from the optical path length adjusting arithmetic unit 17 is output to the servo amplifier of the servomotor 14 for driving the optical path length adjusting means 11 to drive the servomotor 14, and is further fixed to the rotary shaft of the servomotor 14. The optical path length from the laser oscillator to the processing position is moved to the position of the processing head 6 by driving the ball screw 15 that is driven and moving the optical path length adjusting means 11 fixed to the nut portion of the ball screw 15 by the movement amount Lu. Is constant regardless of.

Further, in calculating the movement amount Lu, not only the X and Y directions but also the Z direction is taken into consideration, and (Lx
+ Ly + Lz) / 2 = Lu may be set.

[0018]

As described above, according to the present invention, when a plurality of axes such as the X axis, the Y axis, and the Z axis move simultaneously, it is possible to control the optical path length adjusting means at one place. Since the optical path length can be maintained at a constant distance, the number of mirrors is minimized. Further, the adjusting direction of the optical path length adjusting means is not restricted by the moving direction of the processing head, and the laser processing device can be arranged freely.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a laser processing apparatus according to the present invention.

FIG. 2 is a flowchart showing control of an optical path length adjusting means.

FIG. 3 is a perspective view showing a conventional laser processing apparatus.

FIG. 4 is an optical path diagram showing a difference in diameter of laser light due to a difference in optical path length.

[Explanation of symbols]

 1 ... Laser oscillator 2 ... Laser light 3, 4 ... Bend mirror 5 ... Condensing lens 6 ... Processing head 7 ... Workpiece 8・ ・ ・ Column 9, 10 ・ ・ Bend mirror 11 ・ ・ ・ ・ ・ ・ Optical path length adjusting means 14 ・ ・ ・ ・ Servo motor 15 ・ ・ ・ ・ Ball screw 17 ・ ・ ・ ・ ・ ・ Optical path length adjusting arithmetic unit

Claims (1)

[Claims] 1. A device for processing a workpiece by causing a laser beam emitted from a laser oscillator to enter a processing head provided with a condenser lens, and the processing head being movable in three directions orthogonal to each other. A laser processing apparatus comprising: an optical path length adjusting means for maintaining an optical path length of a laser beam reaching a processing head at a constant distance; and an optical path length adjusting arithmetic device for calculating a movement amount of the optical path length adjusting means.