In stainless steel laser cutting, when air or nitrogen is used as the auxiliary gas, burrs will be generated at the sharp corners of the processed shape or the back of the material at the end of the processing.
The processing machine moves at the set speed, but the processing speed will slow down by the processing machine's characteristics at the sharp corner where the moving axis is converted or at the end of the processing. In general, the set power of the processing machine laser is fixed so that the balance between laser power and speed will be destroyed (excessive output power) at the position where the processing speed slows down, resulting in burrs.
So how to solve this problem? There are three main methods:
1. General processing conditions
In processing conditions, try to reduce the maximum cutting speed to minimize the difference between the maximum and minimum cutting speeds in the entire processing track. Regardless of whether the cutting speed is at the maximum or minimum, the output power should be set according to the condition that the number of burrs is less. The disadvantage of the method is that the average speed will be reduced, making the entire processing time longer.
2. Modify the trajectory
Design the overtravel trajectory so that the cutting speed will not decrease at the sharp corners or the end. For example, program it to do circular overtravel processing at sharp corners. After the loop processing is done, the trajectory will become a gradual change process at the transition of the processing direction, which can avoid a sharp drop in the cutting speed. Using the ring overtravel program at the end of the inner hole machining can also cut the inner hole without reducing the cutting rate. However, the method cannot be used when there is a product near the sharp corner, or the inside and outside of the sharp corner are both products.
3. Control of laser cutting machine
In response to the above problems, we have developed corresponding control functions. Through the real-time detection of the cutting speed of the metal plate laser cutting machine, the function of automatically adjusting the laser output power to the appropriate value according to the change of the cutting speed is realized. When the cutting speed decelerates at the sharp corners, the laser output power is also reduced accordingly, while at the end of the processing, the output power will automatically decrease as the cutting speed decelerates.