"CNC" is a computerized numerical control (CNC) technology in English, referred to as numerical control. Traditional machining is performed by manually operating ordinary machine tools. When machining, the machine tool is shaken by hand to cut metal, and the accuracy of products is measured by eyes with calipers and other tools. Modern industry has already used computer numerically controlled machine tools for operations. CNC machine tools can automatically process any products and parts according to the program prepared by technicians in advance.
It is a method to control the machine tool movement and processing process by using digital information. The machine tool that uses numerical control technology to implement processing control, or the machine tool equipped with numerical control system, is called numerical control (CNC) machine tool. Among them, the numerical control system includes: numerical control device, programmable controller, spindle driver and feeding device. CNC machine tools are highly integrated products of machinery, electricity, fluid, gas and light. To control the machine tool, it is necessary to describe the relative motion between the tool and the workpiece with geometric information and some process parameters that the machine tool processing must have with process information, such as: feed speed, spindle speed, spindle forward and reverse rotation, tool change, coolant switch, etc. These information are formed into processing files (normally referred to as CNC processing programs) in a certain format and stored on information carriers (such as magnetic disks, perforated paper tapes, magnetic tapes, etc.), and then read in by the CNC system on the machine tool or input directly through the keyboard of the NC system, or input through communication and decoding, so that the machine tool can act and process parts Modern CNC machine tools are typical products of mechatronics, and are the technical basis of new generation production technology, computer integrated manufacturing system, etc.
The development trend of modern CNC machine tools is high-speed, high-precision, high reliability, multi-function, compound, intelligent and open structure. The main development trend is to research and develop intelligent full function universal numerical control devices with open software and hardware. Numerical control technology is the basis of machining automation and the core technology of numerical control machine tools. Its level is related to the national strategic position and reflects the level of national comprehensive strength. It develops with the development of information technology, microelectronics technology, automation technology and detection technology.
CNC machining center is a kind of CNC machine tool with tool magazine, which can automatically change tools, and can perform a variety of machining operations on the workpiece within a certain range. The characteristics of machining parts on the machining center are: after the parts to be machined are clamped once, the CNC system can control the machine tool to automatically select and replace tools according to different procedures, automatically change the spindle speed, feed rate of the machine tool, the movement track of the tool relative to the workpiece and other auxiliary functions, and automatically carry out multi process machining for each machining surface of the workpiece, such as drilling, spot facing, reaming, boring, tapping, milling, etc.
Because the machining center can complete multiple processes in a centralized and automatic manner, it can avoid manual operation errors, reduce the time for workpiece clamping, measuring, machine tool adjustment, workpiece turnover, handling and storage, and greatly improve the machining efficiency and accuracy, so it has good economic benefits. Machining centers can be divided into vertical machining centers and horizontal machining centers according to the position of the spindle in space.