CNC machine tool is the abbreviation of computer numerical control machine tools, which is an automatic machine tool equipped with a program control system. The control system can logically process the program with control code or other symbolic instructions, decode it, express it in coded numbers, and input it to the CNC device through the information carrier. After calculation and processing, the numerical control device sends out various control signals to control the action of the machine tool, and automatically processes the parts according to the shape and size required by the drawings. CNC machine tool can solve the processing problems of complex, precise, small batch and multi variety parts. It is a flexible and high-efficiency automatic machine tool, representing the development direction of modern machine tool control technology, and is a typical mechatronic product.
Compared with ordinary machine tools, CNC machine tools have the following characteristics:
1. It has strong adaptability to the processing object, adapts to the characteristics of single piece production of mold and other products, and provides a suitable processing method for mold manufacturing;
2. High machining accuracy and stable machining quality;
3. Multi coordinate linkage can be carried out, and complex parts can be processed;
4. When machining parts are changed, generally only the NC program needs to be changed, which can save production preparation time;
5. The machine tool itself has high precision and rigidity. It can choose favorable processing quantity and has high productivity (generally 3-5 times of that of ordinary machine tools);
6. The machine tool has a high degree of automation, which can reduce the labor intensity;
7. It is conducive to the modernization of production management. Numerical control machine tools use digital information and standard codes to process and transfer information, and use computer control methods, which lays a foundation for the integration of computer-aided design, manufacturing and management;
8. Higher quality requirements for operators and higher technical requirements for maintenance personnel;
9. High reliability.
Compared with traditional machine tools, CNC machine tools have the following characteristics.
1. It is highly flexible to process parts on a CNC machine tool, which mainly depends on the processing program. Unlike ordinary machine tools, it does not need to manufacture, replace many molds and fixtures, and frequently readjust the machine tool. Therefore, the CNC machine tool is suitable for the occasion where the parts processed are frequently changed, that is, it is suitable for the production of single piece and small batch products and the development of new products, thus shortening the production preparation cycle and saving a lot of process equipment costs.
2. High machining accuracy: the machining accuracy of the CNC machine tool can generally reach 0.05-0.1mm. The CNC machine tool is controlled in the form of digital signals. Every time the CNC device outputs a pulse signal, the moving parts of the machine tool move by a pulse equivalent (generally 0.001mm). Moreover, the average error of the reverse clearance and screw pitch of the feed transmission chain of the machine tool can be compensated by the CNC device. Therefore, the positioning accuracy of the CNC machine tool is relatively high.
3. The processing quality is stable and reliable. The same batch of parts are processed on the same machine tool, under the same processing conditions, using the same tools and processing procedures. The path of the tools is completely the same, and the consistency of the parts is good. The quality is stable.
4. CNC machine tools with high productivity can effectively reduce the processing time and auxiliary time of parts. The range of sound speed and feed rate of the main shaft of CNC machine tools is large, allowing the machine tools to perform powerful cutting with large cutting amount. CNC machine tools are entering the era of high-speed machining. The rapid movement and positioning of moving parts of CNC machine tools and high-speed machining have greatly improved productivity. In addition, when used with the tool magazine of the machining center, it can realize continuous processing of multiple processes on one machine tool, reduce the turnover time between processes of semi-finished products, and improve productivity.
5. Improve the working conditions. After the NC machine tool is adjusted before processing, input the program and start it, so that the machine tool can automatically and continuously process until the end of processing. What the operator needs to do is program input, editing, part loading and unloading, tool preparation, observation of machining status, part inspection and other work. The labor intensity is greatly reduced, and the labor of the machine operator tends to be intelligent. In addition, the machine tool is generally combined, which is clean and safe.
6. The use of production management for the processing of modern CNC machine tools can accurately estimate the processing time in advance, standardize and modernize the tools and fixtures used, and facilitate the standardization of processing information. It has been organically combined with computer-aided design and manufacturing (CAD / CAM), and is the foundation of modern integrated manufacturing technology.