In the process of using laser cutting machine cutting sheet metal, often encounter various problems, in order to ensure cutting quality, the following are several common problems and common solutions:

1. Cutting perforation technology:

Any kind of thermal cutting technology, except for a few cases can start from the edge of the plate, the general must have a hole in the plate. Before the laser punching machine is punched out of a punch hole, and then use the laser from the hole at the beginning of cutting. There are two basic methods for piercing a laser cutter without a stamping device:

Blasting and puncturing - the material is irradiated with a continuous laser to form a dimple in the center and then the molten material is quickly removed by an 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 average diameter of the perforation is half of the plate thickness, so the perforation diameter of the plate is larger and not round, so it is not suitable to be used on the parts with high machining accuracy. On the waste. In addition, as the pressure of oxygen used for piercing is the same as when cutting, the spatter is larger.

Pulsed Perforation - Pulsed lasers with high peak power melt or vaporize small amounts of material, often using air or nitrogen as an auxiliary gas to reduce pore expansion due to exothermic oxidation with less gas pressure than when cutting oxygen. Each pulse laser produces only small particle injections, progressively deeper, so the plate piercing time takes a few seconds. Once the perforation is completed, the assisting gas is replaced with oxygen for cutting. This perforated diameter is smaller, the perforation quality is better than the blasting perforation. The laser used for this purpose should not only have higher output power but also more importantly, the time and space characteristics of the beam. Therefore, the general cross-flow CO2 laser can not meet the requirement of laser cutting. In addition pulse perforation also need to have a more reliable air control system to achieve the type of gas, gas pressure switch and perforation time control.

In the case of pulse perforation, in order to obtain high-quality incision, from the workpiece when the static pulse perforation to the workpiece constant speed continuous cutting transition technology should be paid attention to. In theory, the cutting conditions such as focal length, nozzle position, gas pressure and so on can usually be changed in accelerating section, but in fact it is unlikely that the above conditions will be changed due to too short time. In industrial production, it is more practical to change the laser average power mainly by changing the pulse width, changing the pulse frequency, and changing the pulse width and frequency at the same time. The actual results show that the first three kinds of the best results.

2. Cutting holes (small diameter and thickness) Analysis of the deformation:

This is because the machine tool (only for high-power laser cutting machine) in the processing of holes is not to take the way of blasting perforation, but the use of pulse perforation (soft puncture) approach, which makes the laser energy in a very small area is too concentrated, The non-processing area is also scorched, resulting in hole deformation, affecting the processing quality. At this moment, we should change the method of pulse perforation (soft puncture) to blasting puncture (ordinary puncture) in the processing program and solve it. For the smaller power laser cutting machine is exactly the opposite, in the processing of small holes should be taken to puncture the way to get a better surface finish.