First, speed up
             With the rapid development of industries such as automobiles, defense, aerospace, and aerospace, as well as the application of new materials such as aluminum alloys, the requirements for high-speed machining of CNC machine tools have become higher and higher.
           (1) Spindle speed: The machine adopts electric spindle (built-in spindle motor), and the maximum spindle speed reaches 200000r/min;
           (2) Feed rate: When the resolution is 0.01μm, the maximum feed rate reaches 240m/min and the precise processing of complex surfaces can be obtained;
           (3) Speed ​​of operation: The rapid development of microprocessors has provided a guarantee for the development of high-speed and high-precision CNC systems. The CPU has been developed to 32-bit and 64-bit numerical control systems. The frequency has been increased to several hundred megahertz and thousands. megahertz. Due to the greatly increased operating speed, a feed rate of up to 24 to 240 m/min can still be achieved at resolutions of 0.1 μm and 0.01 μm.
           (4) Tool change speed: At present, the tool exchange time of foreign advanced machining centers has generally been around 1s, and the height has reached 0.5s. Chiron Corp. of Germany has designed the tool magazine as a basket style with the spindle as the axis and the tool is arranged on the circumference. The knife-to-knife tool change time is only 0.9s.
     Second, high precision
            The precision requirements of numerically-controlled machine tools are now not limited to static geometrical accuracy. More attention has been paid to machine tool movement accuracy, thermal deformation, and vibration monitoring and compensation.
          (1) Improve CNC system control accuracy: Adopt high-speed interpolation technology to achieve continuous feed with small program segments, refine the CNC control unit, and adopt high-resolution position detection device to improve position detection accuracy (Japan has developed The AC servo motor with built-in position detector of 106 pulses / rev, its position detection accuracy can reach 0.01μm / pulse), the position servo system adopts feedforward control and nonlinear control;
          (2) Error compensation techniques: Backlash compensation, screw pitch error compensation, and tool error compensation techniques are used to comprehensively compensate for thermal distortion and spatial errors in equipment. The research results show that the application of comprehensive error compensation technology can reduce the machining error by 60% to 80%;
          (3) Using a grid decoder to check and improve the precision of the movement trajectory of the machining center, and predict the machining accuracy of the machine tool through simulation, so as to ensure the positioning precision and repeat positioning accuracy of the machine tool, so that its performance is stable over a long period of time and can be under different operating conditions. Complete a variety of processing tasks and ensure the quality of parts processing
      Third, the function of composite
              The meaning of a compound machine tool refers to the realization of a single machine tool or the completion of the processing of various elements from the blank to the finished product. According to its structural characteristics, it can be divided into two types: process complex type and process complex type. Process compound machine tools such as boring and milling and drilling compounding - machining center, turning and milling compounding - turning center, milling and drilling boring machine compounding - compound machining center, etc.; process compound type machine tool such as multi-faceted and multi-axis machining compound machine tool and double spindle Turning center and so on. The use of a compound machine tool to process, reduce the workpiece loading and unloading, replacement and adjustment of the tool's auxiliary time and the error generated in the middle process, improve the part machining accuracy, shorten the product manufacturing cycle, improve the production efficiency and the manufacturer's market reaction ability, Compared with the traditional process of decentralized production methods have obvious advantages.
        IV. System Openness
              (1) Open to future technologies: Since both software and hardware interfaces follow accepted standard protocols, only a few redesigns and adjustments are required. A new generation of general-purpose hardware and software resources may be adopted, absorbed, and compatible with existing systems. This means that the development cost of the system will be greatly reduced and the system performance and reliability will continue to improve and be in a long life cycle;
              (2) Open to users' special requirements: update products, expand functions, provide various combinations of hardware and software products to meet special application requirements;
              (3) The establishment of numerical control standards: Internationally, a new CNC system standard ISO14649 (STEP-NC) is being researched and developed to provide a neutral mechanism that does not depend on specific systems and can describe the entire life cycle of products. Unified data model to achieve standardization of product information throughout the entire manufacturing process and even in various industrial fields. The standardized programming language not only facilitates the use of the user, but also reduces the labor consumption directly related to the operating efficiency.
        Fifth, drive parallelization
                Parallel kinematic machine tool overcomes the inherent defects such as large mass of moving parts, low rigidity of the system, the fact that the tool can only feed along the fixed guide rail, low degree of freedom of operation, insufficient processing flexibility and insufficient maneuverability of the traditional machine tool serial mechanism. For the moving platform) and the base (usually the static platform) using a multi-bar parallel connection mechanism to drive, through the length of the rod in the control rod to make the platform supported by the rod to obtain the corresponding degrees of freedom of movement, can achieve multi-coordinate linkage Processing, assembly and measurement of multiple functions can better meet the processing of complex special parts. It has advantages such as high degree of modularity, light weight, and high speed of modern robots.
                As a new type of processing equipment, the parallel machine tool has become an important research direction of the current machine tool technology and has been highly valued by the international machine tool industry. It is considered to be “the most significant progress in the machine tool industry since the invention of CNC technology” and "A new generation of CNC machining equipment in the 21st century."
        Six, extreme (larger and smaller)
               Large-scale development of defense, aerospace, and aerospace businesses, and basic industries such as energy, require the support of large-scale and well-performing CNC machine tools. Ultra-precision machining technology and micro-nano technology are strategic technologies in the 21st century. New manufacturing processes and equipment that can adapt to micro- and micro/nano-processing precisions need to be developed. Micro-machine tools include micro-cutting (car, milling, grinding) machines. Demand for microelectronics processing machines, micro-laser processing machines and micro-presses is gradually increasing.
        Seven, information exchange network
                For enterprises facing fierce competition, it is very important for NC machines to have bi-directional and high-speed networking communication functions to ensure that information flow is unobstructed among various departments of the workshop. It can not only realize the sharing of network resources, but also realize the remote monitoring, control, training, teaching and management of CNC machine tools. It can also realize the digital service of CNC equipment (remote diagnosis and maintenance of CNC machine tool faults). For example, Mazak Corporation of Japan introduced a new generation of machining centers equipped with an external device called an e-Tower, including computers, mobile phones, off-camera and in-camera cameras, capable of voice, graphics, video, and text The functions of communication fault alarm display and online help troubleshooting are independent and self-managing manufacturing units.
         Eight, the process of greening
                 With increasingly stringent environmental and resource constraints, the greening of manufacturing and processing becomes more and more important, and China's resources and environmental issues are particularly prominent. Therefore, in recent years, machine tools that do not use or minimize the use of coolant, dry cutting, and semi-dry cutting are becoming more and more important and continue to develop. In the 21st century, the major trend of green manufacturing will accelerate the development of various energy-saving and environmental protection machine tools and occupy more world markets.