Laser beam parameters in the laser cutting machine, machine with NC system performance and accuracy will directly affect the efficiency and quality of laser cutting. Especially for high precision cutting or thick parts, must master the key technologies and address the following: 1 the focus position control technology: one of the advantages of laser cutting is the high energy density of the beam, 10W/cm2. Because the energy density is proportional to 4/π D2, so focal spot diameter as small as possible, so as to produce a narrow kerf and focal spot diameter and is directly proportional to the depth of focus of the lens.
Focusing lens focal depth smaller focal spot diameter is smaller. But cutting splashes, too close to the lens away from the workpiece easy lens damage, so widely used in industrial applications of high power CO2 laser cutting machine 5 〃 ~7.5 〃 "(127~190mm) focal length. Actual focal spot diameter between 0.1~0.4mm. For the high quality of cutting, and effective depth and diameter of the lens and the cutting material. For example with 5 〃 lens cutting carbon steels, coke with deep focal length range of +2%, that is 5mm. Position of the control relative to the surface of the material to be cut is very important. Take into consideration the quality of cutting, cutting speed and other factors, in principle 6mm of metal materials, focus on 6mm carbon steel, the focus lay on the surface; 6mm stainless steel, focus under the surface.