1. High Speed
With the rapid development of automobile, national defense, aviation and aerospace industries and the application of new materials such as aluminium alloy, the requirement of high-speed CNC machine tool processing is getting higher and higher.
A. Spindle speed: The machine tool adopts electric spindle (built-in spindle motor), the maximum spindle speed is up to 200000r/min;
B. Feed rate: When the resolution is 0.01 m, the maximum feed rate is 240 m/min, and complex precision machining can be obtained.
Operating speed: The rapid development of microprocessors provides a guarantee for the development of CNC systems to high speed and high precision. CPU has been developed to 32-bit and 64-bit CNC systems, and the frequency has increased to hundreds of MHz and up to gigahertz. Because of the great improvement of operation speed, when the resolution is 0.1 M and 0.01 m, the feed speed can still reach as high as 24-240 m/min.
Tool-changing speed: At present, the tool-changing time of foreign advanced machining centers has generally been about 1 s, up to 0.5 s. German Chiron Company designed the tool warehouse as a basket style, with the spindle as the axis, and the cutter is arranged in the circumference. The time of tool changing from the cutter to the cutter is only 0.9 seconds.
The requirement of accuracy of CNC machine tools is not limited to static geometric accuracy. More and more attention has been paid to the kinematic accuracy, thermal deformation and vibration monitoring and compensation of CNC machine tools.
Improving the control accuracy of CNC system: It uses high-speed interpolation technology to achieve continuous feeding with small program segments, refines the CNC control unit, and uses high-resolution position detection device to improve the position detection accuracy. The position servo system adopts feedforward control and non-linear control methods.
Error compensation technology: it uses reverse clearance compensation, screw pitch error compensation and tool error compensation technology to compensate the thermal deformation error and spatial error of the equipment.
Using the grid decoder to check and improve the locus accuracy of the machining center: it predicts the machining accuracy of the machine tool by simulation, so as to ensure the positioning accuracy and repetitive positioning accuracy of the machine tool. It makes its performance long-term stable, it can complete a variety of processing tasks under different operating conditions, and it can ensure the processing quality of parts.
The meaning of compound machine tool is to realize or complete the processing of various elements from blank to finished product on a machine tool as far as possible. According to its structural characteristics, it can be divided into two types: process compound type and process compound type. Machining center can complete the process of turning, milling, drilling, hobbing, grinding, laser heat treatment . It can complete the entire processing of complex parts. With the continuous improvement of modern mechanical processing requirements, a large number of multi-axis CNC machine tools are more and more welcomed by major enterprises.
4. Intelligent Control
With the development of artificial intelligence technology, in order to meet the development needs of manufacturing flexibility and manufacturing automation, the intelligent degree of NC machine tools is constantly improved. It is embodied in the following aspects:
A. adaptive control technology of machining process;
B. Intelligent optimization and selection of processing parameters;
C. Intelligent fault self-diagnosis and self-repair technology;
D. Intelligent fault playback and fault simulation technology;
E. Intelligent AC servo drive device;
F. Intelligent 4M CNC system: In the manufacturing process, measurement, modeling, processing and machine operation are integrated into one system.
Open to future technology: Since both hardware and software interfaces follow accepted standard protocols, they can adopt, absorb and compatible with new generation of general-purpose hardware and software.
Open to users'special requirements: update products, expand functions, and provide various combinations of hardware and software products to meet special application requirements;
C. Establishment of NC standard: Standardized programming language not only facilitates users, but also reduces labor consumption directly related to operation efficiency.
6. Driving Parallelization
Parallel machine tools are considered as "the most significant progress in machine tool industry since the invention of numerical control technology" and "the new generation of numerical control processing equipment in the 21st century".
7. Extremization (large-scale and miniaturization)
The development of national defense, aviation, aerospace industry and the large-scale equipment of energy and other basic industries need the support of large-scale and good performance CNC machine tools. Ultra-precision machining technology and micro-nano technology are strategic technologies in the 21st century. New manufacturing technologies and equipment that can adapt to micro-size and micro-nano processing accuracy need to be developed.
Information Interaction and Networking
It can not only realize the sharing of network resources, but also realize the remote monitoring, control, remote diagnosis and maintenance of CNC machine tools.
In recent years, there have been more and more machines that do not use or use less coolant, and realize energy saving and environmental protection in dry cutting and semi-dry cutting. The trend of green manufacturing has accelerated the development of various energy saving and environmental protection machines.
10. Application of Multimedia Technology
Multimedia technology integrates computer, audio-visual technology and communication technology, enables computers to have the ability of processing sound, text, image and video information comprehensively. It can integrate and intellectualize information processing, and be applied to real-time monitoring system, fault diagnosis of production field equipment, monitoring of production process parameters, etc. Therefore, it has great application value.