The key technology of 3D CNC laser cutting machine

To develop a 3D CNC laser cutting machine with high-efficiency and high-precision automatic cutting, it is necessary to carry out research on the following key technologies.　　 High-precision and long-travel six-axis mechanical system design and manufacturing technology. The 3D CNC laser cutting machine has 4 linear motion axes X/Y/Z/C and two rotary motion axes A/B. The linear motion axis stroke and the rotary motion axis rotation range have large requirements. It is a complex six-axis precision mechanical system, which is difficult to design and manufacture. It is necessary to adopt a combination of empirical design, finite element calculation and experimental verification, and make full use of the machine tool structure optimization design technology based on computer simulation to perform finite element analysis on the key components and the whole of the 3D CNC laser cutting machine, and improve the machine tool through mechanical structure optimization. The dynamic characteristics of the machine ensure the stability of the machine during high-speed cutting.　　 Long-distance multi-joint rotation optical path design. In order to avoid the vibration of the laser during the laser cutting process and ensure the quality of the laser beam, the 3D CNC laser cutting machine generally adopts a structure in which the laser is separated from the machine tool. Because the processing range of 3D CNC laser cutting machines is relatively large, this makes the laser light guide light path long, and the laser will have a certain energy attenuation during the long optical path transmission process. In addition, the 3D laser cutting machine has an A/B rotation axis with a large rotation range, so that the light guide system not only needs to change the position of the reflector, but also needs to change the angle of the reflector to achieve laser transmission. Transmitting laser light through the change of the angle of the reflector will cause the problem of laser reflection error amplification. Development of 3D laser processing head. The 3D laser processing head is the key component of the 3D CNC laser cutting machine, including the realization of the A/B axis rotary motion mechanism and the C axis focus automatic tracking linear motion, auxiliary gas nozzle, laser focusing device, collision protection device, water, gas and electrical interface And sealed. The movement accuracy and positioning accuracy of the 3D laser processing head directly affects the final processing accuracy of the laser, and the installation accuracy of the auxiliary gas nozzle and laser focusing device affects the quality of laser cutting. It is also necessary to prevent the temperature of the processing head from increasing due to long-term laser processing. Technical difficulties affecting its working characteristics, so the independent development of 3D laser processing head is very difficult.　　 Six-axis five-link CNC system development. The CNC system of the 3D laser cutting machine needs to have a five-axis linkage function. Moreover, because the laser cutting trajectory is a spatial curve, a large number of tiny line segments are generally used for fitting through end-to-end connections when performing CNC programming. This requires that the CNC system has a forward-looking function in the process of high-speed processing, and is connected through line segments. The smooth transition of speed prevents repeated rise and fall in the cutting process and the inability to meet the specified cutting speed requirements, and avoids overburning. The current 3D laser cutting machine numerical control system has a small range of options, and it is difficult to carry out secondary development for the laser cutting process.　　 Research on the laser cutting process of metal sheet parts. Laser cutting is essentially the result of the interaction between the high-energy laser beam and the auxiliary gas. On the one hand, the high-energy beam melts or even vaporizes the processing material, and on the other hand, the auxiliary gas discharges the molten metal and part of the heat from the incision. Therefore, the energy distribution of laser processing, the transition of metal liquid-solid state, auxiliary gas pressure and flow characteristics are important factors that affect cutting quality and efficiency. It is necessary to study the influence of auxiliary gas pressure, nozzle type, laser power and other process parameters on cutting speed and quality by using a combination of theoretical analysis, numerical simulation and experiment. Through reasonable configuration of process parameters, the efficiency and quality of laser cutting are improved. The application of 3D laser cutting technology and equipment in my country is still in its infancy. Only a few joint venture auto companies have begun to introduce such equipment for trimming of stamping parts and the development of prototype auto body parts. Compared with the developed international auto industry, my country’s auto industry The application level of 3D laser cutting is still far behind. The vigorous development of my country's automobile industry requires more localized 3D CNC laser cutting machines to meet the demand, which will provide a lot of market space for the promotion of 3D laser cutting machines.