1.3.1 Characteristics of CNC machine tools
CNC machine tools are electromechanical integrated machine tools based on electronic control, which give full play to the unique advantages of microelectronics and computer technology. They are easy to realize informatization, intelligence and network training, and can easily form various advanced manufacturing systems, such as flexible manufacturing system (FMS) and computer integrated manufacturing system (CIMS), which can maximize the efficiency of industrial production; The combination of hardware and software can realize the functions of information feedback, compensation, automatic acceleration and deceleration, and further improve the machining accuracy, efficiency and automation of the machine tool.
The machining process of parts by CNC machine tools is carried out in strict accordance with the parameters and actions specified in the machining program. It is a high-efficiency automatic or semi-automatic machine tool. The machining process of the NC machine tool can be programmed arbitrarily, the spindle and feed speed can be changed according to the needs of the machining process, and multi coordinate linkage can be realized, which is easy to process complex surfaces. It has the characteristics of “changeable, changeable and changeable” during processing, and it is convenient to change batches and adjust. It can realize the flexible production of multiple varieties and small and medium batches of complex parts, and meet the needs of society for product diversification.
Compared with ordinary processing equipment, CNC machine tools have the following characteristics, as shown in table 1-4.
Table 1-4 characteristics of CNC machine tools
| Serial number | Content | Description |
| 1 | It has wide adaptability and greater flexibility | The CNC machine tool has the function of multi axis linkage, which can change the processing program according to the processing requirements of parts, and can solve the automation problem of single piece and small batch production. CNC machine tools can complete many parts processing work that ordinary machine tools are not competent for, such as impeller and other complex surface processing. Because CNC machine tools can realize the linkage of multiple coordinates, CNC machine tools can complete the machining of complex surfaces. Especially for parts with complex shapes that can be expressed by mathematical equations and coordinate points, its processing is very convenient. When changing the processing parts, the CNC machine tool only needs to change the part processing program, and the complete set of fixtures with group technology can be used. Therefore, the production preparation cycle is short, which is conducive to the rapid renewal of mechanical products |
| 2 | High processing accuracy and stable product quality | The CNC machine tool automatically processes according to the pre programmed program, and the processing process does not need manual intervention. The repetition accuracy of the processed parts is high, and the consistency of the parts is good. For the same batch of parts, due to the use of the same numerical control machine tool and tool and the same processing program, the motion path of the tool is exactly the same, and the numerical control machine tool is automatically processed by computer control according to the numerical control program, so it avoids human errors, ensures the consistency of parts processing, and the quality is stable and reliable
In addition, the CNC machine tool itself has high precision, good stiffness and good accuracy retention, which can maintain the machining accuracy for a long time. numerical control machine |
| 3 | High automation and productivity | The CNC machine tool itself has high precision and high stiffness. It can use large cutting parameters, with less downtime and detection times, and short processing preparation time, which effectively saves machine hours. It also has the functions of automatic speed change, automatic tool change and other auxiliary operation automation, which greatly shortens the auxiliary time, and does not need the inspection and measurement between processes. Its production efficiency is 3-4 times higher than that of ordinary machine tools. For the processing of some complex parts, its production efficiency can be increased by more than ten times or even dozens of times. The spindle speed and feed range of CNC machine tools are larger than those of ordinary machine tools |
| 4 | Centralized process, one machine for multiple purposes | When replacing the processed parts, the NC machine tool can easily save the original processing program and related process parameters, and there is no need to replace the cam, profiling and other process equipment, so there is no such process equipment to be saved, so the production preparation time can be shortened. It greatly saves the area of the plant. Machining centers adopt composite processes such as multi spindle, lathe compound, indexing worktable or CNC rotary worktable, which can realize multiple functions of one machine, realize multi station, multi surface and multi knife processing in one-time part positioning and clamping, save the process of workpiece transportation and transmission between processes, reduce the number and time of workpiece clamping and measurement, improve the machining accuracy, save the plant area, and improve the production efficiency |
| 5 | Conducive to the modernization of production management | When NC machine tools process parts, they can accurately calculate the processing hours of parts, and effectively simplify the management of inspection, tooling and semi-finished products; CNC machine tools have communication interfaces, which can be connected to computers or local area networks. These are conducive to the development of computer control and management, and create conditions for the automation of production process. NC machine tool is a highly automated machine tool. The whole processing process adopts program control. Before NC processing, detailed processing technology and programming need to be done, and the preparatory work is relatively complex. Because the machining accuracy of machine tools is affected by factors such as large cutting quantities and large calorific value of continuous processing, its design requirements are more stringent than those of ordinary machine tools, and the manufacturing requirements are more precise. Therefore, the manufacturing cost of NC machine tools is relatively high. In addition, CNC machine tools are typical mechatronics products, with complex control systems, high technical content, and high precision of some components and parts, so it is difficult to debug and maintain CNC machine tools. |
