JPH0630826B2 - Laser processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of a laser processing apparatus.

[Prior Art] A CO laser (λ = 10.6 μm) is widely used for industrial purposes because it can produce an oscillator with high efficiency and large output at low cost. Also, since the YAG laser has a smaller wavelength than the CO laser (λ = 1.06 μm), it is suitable for fine processing.
It is widely used like the O laser. These laser oscillators use electrical energy to excite the laser, and
The O laser excites the laser medium by the discharge and the YAG laser excites the laser medium by the flash lamp to cause the laser oscillation operation, and the laser output thereof increases in accordance with the input of the excitation power supply.

[Problems to be Solved by the Invention] In the conventional laser processing, processing with a constant laser output is often performed, and the request for processing accuracy is not so high. However, in recent years, the processing parts to be laser processed have become complicated and diversified, and the processing accuracy is required to be 0.05 mm or less in the case of CO laser. Precision machining has come to be performed by automatically controlling the machining conditions.

FIG. 2 is a configuration diagram of a laser processing apparatus that performs cutting processing using a laser beam, 1 is a laser oscillator, 2 is an excitation power source,
3 is a bend mirror, 4 is a processing lens, 5 is a work, 6 is a Kenzan pin, 7 is an XY table, and 8 is a numerical control device (hereinafter referred to as NC device).

As shown in the figure, the laser beam output from the laser oscillator 1 is reflected by the bend mirror 3, condensed by the processing lens 4, focused on the work 5, and the work 5 is cut. The NC device 8 moves the XY table 7 according to a program created in advance according to the machining shape.

In the case of cutting processing, laser processing is a processing that does not use a mold, so it is often used for processing of curved edges other than sharp edges, circles and corners, but even if it has a straight part There are many examples in which the processing time is shortened, such as processing a part at high output and high speed and processing a fine part at low output and low speed.

At this time, the optical axis of the laser beam output from the laser oscillator changes slightly (θ = ± 0.5 mrad) as shown in the figure depending on the magnitude of the output, that is, the optical axis shifts. The focus position on the work piece is deviated by h shown in the following equation (1). Note that f is the focal length of the processed lens 4.

h = fθ (1) In formula (1), if f is 5 ″ (127 mm), the deviation amount h is h = 127 × 1/1000 = 0.127 mm, and the deviation amount h The machining accuracy is greater than 0.05 mm, and the machining accuracy cannot be guaranteed.As a result, the machining program must be corrected and re-machined, which requires much labor and time. This is a problem of the conventional laser processing apparatus.

The present invention has been made in order to solve the problems of the above-described conventional apparatus, and it is an object of the present invention to provide a laser processing apparatus that saves time and effort such as correction, re-processing, and re-measurement of a processing program, and that performs inexpensive and highly accurate processing. To do.

[Means for Solving Problems] A laser processing apparatus according to the present invention collects a laser beam output from a laser oscillator and irradiates the workpiece with a condensing means, and a condensing means according to a program position command value. In an apparatus for processing a workpiece with a laser beam, the NC apparatus includes an NC device for moving the means relative to the workpiece, and the NC device has an excitation input A or Using a relationship between the change in the laser output B and the amount h of focus position deviation of the laser beam corresponding to this change, there is a calculation means for obtaining h as a function of A or B, and A or B is taken in as an input signal. The calculation means calculates h corresponding to A or B, the program position command value is corrected by h, and the light collection means is moved relative to the workpiece.

[Operation] In the present invention, the NC device uses the relationship between the change in the excitation input A or the laser output B of the laser oscillator, which has been obtained in advance, and the focus position deviation amount h of the laser beam corresponding to this change. , H as a function of A or B, and A or B as an input signal is taken in to obtain h corresponding to A or B by the arithmetic means and the program position command value is corrected by h. Even if there is no optical axis, the correction of h can be performed without providing a detector for detecting the deviation, and the processing accuracy does not decrease.

[Embodiment of the Invention] FIG. 1 is a block diagram of a laser processing apparatus according to an embodiment of the present invention. In the figure, 1 to 8 are the same parts as a conventional apparatus, and 9 is a pumping input to an NC apparatus 8. Is an input.

In the present invention, the laser excitation input A of the laser oscillator 1
In advance, measure the inclination θ of the optical axis of the laser beam corresponding to
The relationship between A value and θ θ = F (A) …………………………………………………………………………………………………………………………………………………………………………………… (2) Is obtained.

That is, if θ is measured and Equation (2) is obtained from the relationship with the excitation input A at that time, the deviation amount h of the focal position of the laser beam can be obtained as a function of the excitation input A. Therefore, the excitation input A is input to the NC device 8 and the calculation by the equation (3) is performed in the device 8 to obtain h, and the NC device 8 corrects the program position command value by the deviation amount h of the focal position. Operate. As a result, even if the optical axis of the laser beam has an inclination θ, it is possible to obtain a processing result according to the program position command value.

In the present embodiment, the laser excitation input A and the deviation amount h
However, the laser output B may be used instead of the laser excitation input.

Also, this practical example is an example using a CO laser beam,
A YAG laser or another laser beam may be used. Further, although an XY table is used for moving the work, a beam moving type may be used, and the condensing system may be another condensing system such as a concave mirror instead of the processing lens.

[Advantages of the Invention] As described above, according to the present invention, the NC device obtains a change in the excitation input A or the laser output B of the laser oscillator, which is obtained in advance, and the focus position deviation amount h of the laser beam corresponding to the change. By using the relationship of A to B as a function of A or B, and taking A or B as an input signal to calculate h corresponding to A or B by the calculation unit and correcting the program position command value by h. Therefore, even if the optical axis of the laser beam shifts, h can be corrected without providing a detector for detecting the shift, and the laser beam moves according to a predetermined program position command value to process the workpiece. .
Therefore, there is an excellent effect that a predetermined processing accuracy is guaranteed.

[Brief description of drawings]

FIG. 1 is a block diagram of a laser processing apparatus which is an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional laser processing apparatus. In the figure, 1 is a laser oscillator, 2 is an excitation power supply, 3 is a bend mirror, 4 is a processing lens, 5 is a work, 7 is an XY table,
Reference numeral 8 is an NC device, and 9 is an input of an excitation input to the NC device. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A focusing means for focusing a laser beam output from a laser oscillator and irradiating the workpiece with the laser beam, and moving the focusing means relative to the workpiece according to a program position command value. And a numerical control device for processing the workpiece with the laser beam, wherein the numerical control device changes the excitation input A or the laser output B of the laser oscillator that is obtained in advance. Using the relationship with the focal position deviation amount h of the laser beam corresponding to this change, there is a calculating means for obtaining the above h as a function of A or B, and the above calculating means takes in the above A or B as an input signal. The feature is that h corresponding to A or B is obtained, the program position command value is corrected by the above h, and the light converging means is moved relative to the workpiece. The processing equipment.