The metal industry is one of the most important application markets for laser processing, and the competition in China's sheet metal market will turn to the competition of high-quality, high-tech products. Therefore, in order to comply with the development trend of the international market, the transformation of processing technology is inevitable in the sheet metal processing industry.
1. Cutting and Piercing Technology
Any thermal cutting technique, except in a few cases where it can start from the edge of the board, generally must pass a small hole in the board. Generally, when the design part has no roughness requirements for the surface cutting fracture, it is possible to do no manual processing during the laser cutting programming, and let the control software automatically generate the puncture point; however, when the design has a higher roughness for the cutting section of the part to be processed When required, we should pay attention to this problem. Usually, it is necessary to manually adjust the starting position of the laser beam when programming the laser cutting program, that is, manual control of the puncture point. This hole is similar to the threading hole for wire cutting. The laser beam uses this hole as the starting point for processing contour cutting. Usually, the running direction of the laser beam in the flying light path is perpendicular to the tangent direction of the cutting contour of the machined part. In this way, the diameter of the perforation is smaller, and the perforation quality is better than that of the perforation.
Pulse perforation - a high peak power pulse laser is used to melt or vaporize a small amount of material. Air or nitrogen is often used as an auxiliary gas to reduce the expansion of the hole due to exothermic oxidation. The gas pressure is lower than the oxygen pressure during cutting. It is necessary to move the puncture point originally generated by the laser program to the required reasonable position to meet the requirements for the surface accuracy of the machined parts. In addition, pulse perforation also needs a more reliable gas circuit control system to realize the switching of gas type, gas pressure and control of perforation time.
2. The solution to the burr on the workpiece when laser cutting mild steel
According to the working and design principle of CO2 laser cutting, it is concluded that the following reasons are the main reasons for the burr of the workpiece: the upper and lower positions of the laser focus are not correct, and it is necessary to do a focus position test and adjust according to the offset of the focus; If the output power of the laser is not enough, it is necessary to check whether the laser generator is working normally. If it is normal, observe whether the output value of the laser control button is correct and adjust it; the cutting line speed is too slow, and it is necessary to increase the line speed during operation control; If the purity of the cutting gas is not enough, it is necessary to provide high-quality cutting working gas; if the laser focus is offset, it is necessary to do a focus position test and adjust it according to the offset of the focus; if the machine tool runs for too long, it needs to be turned off at this time. Restart. At this time, when other parameters are normal, the following conditions should be considered: the loss of the laser head nozzle, the nozzle should be replaced in time. Therefore, it is necessary to pay attention to this aspect when using laser cutting to process parts. At this time, other factors of the machine tool should be considered comprehensively, such as whether the nozzle needs to be replaced, and the movement of the guide rail is unstable. The actual results show that the third one is the best. For the laser cutting machine with lower power, it is just the opposite. When processing small holes, pulse perforation should be adopted to obtain better surface finish. Once the piercing is complete, immediately change the assist gas to oxygen for cutting. The laser used for this purpose should not only have high output power; more importantly, the time and space characteristics of the beam, so the general cross-flow CO2 laser can not meet the requirements of laser cutting.
3. Selection of puncture point during laser cutting
The working principle of the laser beam during the processing of the fiber laser cutting machine is: during the processing, the material is irradiated by the continuous laser to form a pit in the center, and then the molten material is quickly removed by the working airflow coaxial with the laser beam to form a hole.
4. Analysis of burrs on workpieces when laser cutting stainless steel and aluminum-zinc plate
When the above situation occurs, first consider the factor of burrs when cutting low carbon steel, but the cutting speed cannot be simply accelerated, because sometimes the plate cannot be cut through when the speed is increased, which is particularly prominent when processing aluminum-zinc plates.
In industrial production, it is more realistic to mainly use the method of changing the average power of the laser. The specific method is to change the pulse width; change the pulse frequency; and change the pulse width and frequency at the same time. Previously, on the laser stamping compound machine, a punch was used to punch a hole, and then a laser was used to start cutting from the small hole. In this way, a relatively rough cutting surface will flow down on the cutting section of the material to be processed, which is mainly caused by the rapid change of the vector direction of the laser beam during the movement in a short period of time.
5. Solutions to abnormal sparks when cutting mild steel
This situation will affect the quality of the cut section finish of the part. At this time, the cutting should be suspended immediately, the connection status of the laser head should be checked, and the thread should be re-threaded. In the case of no new nozzle replacement, the cutting working gas pressure should be increased; the thread at the connection between the nozzle and the laser head is loose.
Tianhong laser metal sheet laser cutting machine can perfectly meet your demand of metal processing demand.
