JPH0216195B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of cutting a plate or the like into a desired shape using a high-energy beam such as a laser, microwave, electron beam, ion beam, or plasma.

Conventional machining using a high-energy beam typically involves cutting at once using a beam output that is sufficient for cutting the material, plate thickness, etc. of the workpiece. In this case, as the beam output increases, it is not easy to narrow down the beam spot sufficiently, and since rough machining is performed at high output, it is inevitable that the accuracy of the machined shape will deteriorate.

The present invention was proposed in order to eliminate this drawback, and the beam output is sufficiently reduced to enable high-precision machining, and the relative movement of the machining shape to the workpiece is repeated multiple times. It is characterized in that the machining is performed by shifting the locus of movement in at least the final round of repeated machining in a direction that reduces or enlarges it.

The present invention will be explained below with reference to one example. 1 is a workpiece, 2 is a table that fixedly supports the workpiece 1 and feeds the processed shape, 3 and 4 are X-axis and Y-axis motors that drive the table, and 5 is a numerical control device that applies NC control signals to the motors. , 6 is a laser oscillator, 7 is a reflecting mirror, and 8 is a lens for condensing the laser beam.

A focused laser beam is irradiated onto the workpiece 1 by the lens 8, and the motors 3 and 4 are driven and controlled by the NC control device 5 to provide the workpiece 1 with relative movement and feed in a required cut shape. As a result, the laser beam irradiation point on the workpiece 1 rapidly melts and vaporizes and melts, and by continuing processing while moving the irradiation point, the workpiece 1 can be cut into a relative moving shape.

However, as the energy of the beam spot connected to the workpiece 1 increases, it generally becomes difficult to reduce the diameter of the beam spot. For example, when using a CO ₂ gas laser, the beam diameter output from the oscillator 6 is approximately 12 mmφ at an output of 100W, 16mmφ at 300W,
At 600W, it becomes 20mmφ, and at 1KW, it becomes about 38mmφ. Therefore, increasing the beam output increases the groove width of the beam cut, resulting in a decrease in processing accuracy.
Furthermore, the high energy makes the machined surface rough, which also impairs accuracy.

Therefore, in the present invention, processing is performed with the oscillation output sufficiently reduced, and cutting is repeated a plurality of times. By reducing the energy, the beam spot can be narrowed down to a minimum value close to the wavelength, and precision machining can be performed by repeatedly cutting with this fine beam until the machining is completed. Moreover, it is inevitable that the width of the machined groove is formed into a tapered shape that slopes upward and downward due to repeated machining, so it is necessary to shift the erroneous taper placement in the direction that reduces or expands the locus of movement at least in the final time during repeated machining. By performing machining using the same method, the wall surface of the machining groove in the shift direction can be cut vertically, allowing for precise machining.

To explain with an experimental example, a thickness of 6 mm is produced using a YAG laser.
When cutting a ruby, the beam was focused to a spot diameter of about 8μφ with an average power of 50W, and the same trajectory was cut by repeating the process six times. For comparison, the dimensional accuracy of the inner diameter when cutting was performed once with an output of 250 W was as follows.

Output Upper side (mm) Lower side (mm) 50W 42.21 42.23 250W 43.11 43.24 According to the conventional method of increasing the beam output and cutting with one machining feed, the dimensional accuracy is 1 mm or more higher than the present invention. It can be seen that compared to this, the method according to the present invention can improve accuracy. Furthermore, according to the present invention (50W), the dimensional difference between the upper and lower sides of the cut workpiece is approximately 0.02 mm, compared to the conventional method (250W).
It can be seen that the accuracy is higher for vertical cuts compared to about 0.13.

Also, when machining is performed by shifting the machining trajectory inward by 4 μm from the second time onward using the present invention (50W),
By repeating the process six times, the inner groove wall could be cut almost vertically.

Incidentally, even if the shift is not carried out every time it is repeated, it is effective even if the shift is performed only at least in the last cycle, and in that case, if the shift amount is set to a value corresponding to the dimensional difference in which the taper is formed, a vertical cut can be made. In addition, when cutting and precision finishing the outside, by controlling the shift control outward, the outer groove wall can be vertically cut and finished with high precision. By inputting a program into the NC device 5 in advance, feed control for such repeated machining can be performed automatically and with high precision. The processing shape feed can also be performed by fixing the workpiece and applying the feed to the head side that irradiates the laser beam.

Further, the present invention can be used using microwaves as a high-energy beam for processing, and electron or ion beams can also be used as a vacuum atmosphere.

[Brief explanation of drawings]

The drawing is a configuration diagram of an embodiment of the device in this description. 1... Workpiece, 2... Table, 3, 4...
Motor, 5... NC control device, 6... Laser oscillator, 7... Reflector, 8... Lens.

Claims (1)

[Claims] 1. A beam irradiation device for irradiating a high-energy beam onto a workpiece is provided, a movement control device is provided for relative movement of a desired cut shape between the workpiece and the irradiation beam of the beam irradiation device, When cutting is performed by irradiating a moving shape with a high-energy beam, the beam irradiation device is controlled to reduce the beam output sufficiently to enable high-precision machining, and the movement control device is controlled to cut the processed shape. A high-energy beam cut processing method, characterized in that processing is performed by repeating the relative movement of a plurality of times, and the processing is performed by shifting the locus of movement of at least the last time during the repeated processing in a direction of reducing or enlarging.