Several key technologies of laser cutting machines are integrated technologies of light, machine and electricity. The parameters of the laser beam, the performance and accuracy of the machine and the CNC system in the laser cutting machine directly affect the efficiency and quality of the laser cutting. Especially for parts with high cutting precision or large thickness, the following key technologies must be mastered and solved:
1. Focus position control technology: One of the advantages of laser cutting is that the energy density of the beam is high, generally 10W/cm2. Since the energy density is proportional to 4/πd2, the focal spot diameter is as small as possible to produce a narrow slit; and the focal spot diameter is also proportional to the focal depth of the lens. The smaller the focal depth of the focusing lens, the smaller the focal spot diameter. However, the cutting has a splash, and the lens is too close to the workpiece to damage the lens. Therefore, the industrial focus of the high-power CO2 laser cutting machine is widely used in the industrial range of 5〃~7.5〃〞 (127~190mm). The actual focal spot diameter is 0.1~0.4. Between mm. For high quality cuts, the effective depth of focus is also related to the lens diameter and the material being cut.
2. Cutting perforation technology: Any kind of thermal cutting technology, except for a few cases, can start from the edge of the board, generally a small hole must be worn on the board.
3. Nozzle design and airflow control technology: When laser cutting steel, oxygen and focused laser beam are sent through the nozzle to the material to be cut to form a stream of air. The basic requirement for airflow is that the airflow into the slit is large and the velocity is high so that sufficient oxidation causes the slit material to undergo an exothermic reaction; the colleague has sufficient momentum to spray the molten material out. Therefore, the design of the nozzle and the control of the gas flow (such as the pressure of the nozzle, the position of the workpiece in the air flow, etc.) are also important factors in terms of the quality of the beam and its control directly affecting the cutting quality.