1. Incision and perforation skills
Any kind of eager opening skill, except for a few situations that can start from the edge of the board, usually must have a small hole in the board. Previously, a hole was punched with a punch on the laser stamping compound machine, and then cut with a laser from the small hole. There are two basic methods for laser cutting without punching equipment:
Pulse perforation - select the pulse laser with peak power to melt or vaporize a few data, and usually use air or nitrogen as the auxiliary gas to reduce the hole expansion caused by exothermic oxidation. The gas pressure is smaller than the oxygen pressure at the time of incision. Each pulse laser only produces small particle eruption and gradually deepens, so it takes a few seconds for the thick plate to pierce. Once the perforation is completed, the auxiliary gas will be replaced by oxygen for incision. In this way, the perforation diameter is smaller, and the perforation quality is better than that of explosion perforation. Therefore, the laser used should not only have high output power; What is more important is the temporal and spatial characteristics of the light beam. In addition, the pulse perforation must have a more reliable gas path control system to complete the switching of gas type and gas pressure and the control of perforation time.
Explosive perforation - the data is illuminated by a continuous laser to form a pit in the middle, and then the molten data is quickly removed by the oxygen flow coaxial with the laser beam to form a hole. Generally, the size of the hole is related to the thickness of the plate. The uniform diameter of the explosive perforation is half of the thickness of the plate. Therefore, the hole diameter of the explosive perforation of the thicker plate is large and not round, so it is not suitable to be used on parts with high machining accuracy requirements, but only on waste materials. In addition, because the oxygen pressure used for perforation is the same as that used for incision, the splash is large.
2. Analysis of burrs on workpieces during laser cutting and processing of stainless steel and aluminum zinc coated plates
The presentation of the above situation, first of all, we should think about the elements of burrs when cutting low-carbon steel, but we can't simply accelerate the cutting speed. Because the adding speed sometimes presents the situation that the plate can't be cut through, this situation is particularly outstanding when processing aluminum coated zinc plate. At this time, we should summarize and consider other elements of the machine tool to solve them, such as whether the nozzle should be replaced, the guide rail movement is unstable, etc.
3. Analysis of deformation condition of cutting and processing small holes
This is because the machine tool does not adopt the method of explosive perforation when machining small holes, but uses the method of pulse perforation, which makes the laser energy converge too much in a small area, scorching the non machining area, forming hole deformation and affecting the processing quality. At this time, we should change the pulse perforation method into the explosive perforation method in the processing program to solve it. On the contrary, the method of pulse perforation should be adopted in the small hole processing in order to obtain a better surface finish.
4. Solutions to abnormal sparks when cutting low carbon steel
This condition will affect the cutting section finish and machining quality of parts. At this moment, when other parameters are normal, we should consider the following conditions: the loss of nozzel of laser head nozzle, and the nozzle should be replaced in time. When there is no new nozzle replacement, the gas pressure of cutting operation should be increased; The thread at the connection between the nozzle and the laser is loose. At this moment, immediately stop cutting, check the connection condition of the laser head, and fix the thread from the head.
5. Solutions to burrs on workpieces when laser cutting low carbon steel
According to the operation and planning principle of laser cutting, it is analyzed that the following reasons are the primary reasons for the burr of machined parts: the up and down orientation of the laser focus is incorrect, so it is necessary to test the orientation of the focus and adjust it according to the offset of the focus; The output power of the laser is not good. You need to check whether the operation of the laser generator is normal. If it is normal, investigate whether the output value of the laser control button is correct and adjust it; The linear speed of cutting is too slow, so it is necessary to increase the linear speed during operation and control; The purity of cutting gas is not good, and high-quality cutting gas is required; If the laser focus is offset, it is required to do a focus orientation test and adjust it according to the offset of the focus; The machine tool runs for a long time, showing instability. At this moment, it needs to shut down and start from scratch.