It is difficult for us to make the cutting head absolutely pollution-free, but we can extend the service time and reduce the degree of pollution through some methods, so as to improve the service life of the cutting head and reduce its maintenance and repair costs.
For the above listed contamination factors that lead to the cutting head lens, the corresponding measures can be taken as follows:
1. Improve the installation method of the optical fiber head
Improve the installation method so that the optical fiber head is horizontally inserted into the cutting head and locked. Note that the surrounding environment should be as clean as possible. If there are many suspended particles (dust) around, it is recommended to do this work before going to work at 600 in the morning.
2. Improve the sealing effect of the cutting head
According to the current level of mechanical manufacturing, even with the most advanced German technology, the laser cutting head cannot be completely sealed. In the later use process, dust will inevitably enter and contaminate the lens. The reason is that the temperature of the cutting head increases during the cutting process (the cutting head
When the temperature is <55*C, it can be cut normally), the internal air pressure will increase, and part of the gas will be pressed out of the cutting head and emitted into the surrounding environment. After the cutting head stops working (after workers get off work), when the internal temperature drops to the ambient temperature, the internal air pressure is lower than the ambient air pressure, and the external air contains dust
The gas will be pressed into the cutting head until the internal and external air pressures are balanced, at which point the cutting head is contaminated.
The idea to solve this problem is to keep the air pressure inside the cutting head always positive (greater than the ambient air pressure), so as to isolate the dust gas in the environment from entering the cutting head.
Improvement methods are as follows:
(1) Always feed clean, dry and oil-free gas into the cutting head (nitrogen recommended, 0.15bars pressure <0.3bar);
(2) Install the breathing system, and always keep the inside of the cutting head in a positive pressure state.
3. Correctly replace the protective mirror
When replacing the protective mirror, it is required to be fast; and while pulling out the protective mirror window box, immediately seal the upper window of the cutting head with paper tape (the installation opening of the cutting protective mirror window box), and do not let dirty things touch it. Protective glasses, while the operator can not speak (to prevent saliva from splashing to the protection
mirror).
4. Reasonable design of machine tool control sequence
The propagation speed of light is greater than the gas transmission speed, and the cutting gas will lag when cutting or puncturing. The laser starts processing and the cutting gas has not yet reached the required pressure or flow rate, resulting in contamination of the protective mirror.
Improvement methods are as follows:
(1)Modify the timing of light output and gas output (cutting gas), instruct gas output - wait for a certain time (gas waiting) - light output - processing.
(2) The gas (shielding gas) that always maintains a certain pressure during the whole processing process, the processing sequence: command the shielding gas - plate preprocessing (read processing data and define the origin, etc.) - command the puncture gas - command the puncture laser - Command out cutting gas - Command out cutting laser (cut contour) - Contour cutting end - Quickly locate to the next contour - Command out puncture gas - Command out puncture laser - Command out cutting gas - Command out cutting laser (cutting contour) - End of contour cutting - cycle - end of cutting process - close shielding gas - end of gas program.
5. Reasonable cutting process data
Using reasonable cutting process data will avoid the occurrence of cutting head contamination caused by abnormal cutting.
6. Use qualified wearing parts
The selection of qualified wearing parts such as protective glasses and O-rings will help to seal the cutting head.
7. Correct operation method
Use the machine tool correctly according to the equipment supplier's usage requirements.
8. Correct maintenance method
Make sure the cutting head is clean and dry, and clean it daily.
Epilogue
Through the application of the above pollution prevention method, the pollution condition of the optical lens in the optical fiber cutting head is greatly improved. The practical application shows that as long as regular maintenance is done and attention to detail is paid, parts will not be cut and scrapped frequently, the service life of the lens will be prolonged, and the production efficiency of the equipment will be improved.
Post time: 20-08-22
