Numerical control machining centers are divided into boring and milling and turning according to their processing procedures, and can be divided into three-axis, four-axis and five-axis machining centers according to the number of control axes.
1, boring and milling machining center
The tool magazine and automatic tool changer are the main differences between machining centers and CNC milling machines. The machining center MC is a CNC machine tool with a tool magazine and an automatic tool changer. It combines the functions of a CNC milling machine, a CNC boring machine, and a CNC drilling machine with powerful functions. The CNC milling machine has no tool magazine and automatic tool changer. The boring and milling machining center concentrates the functions of milling, boring, drilling, and machining of internal and external threads on a single device, so that it has a variety of technological means. It is equipped with a tool magazine, in which various tools or inspection tools of different quantities are stored, which are automatically selected and replaced by the program during the machining process.
According to the state of the spindle in the space, it is divided into a vertical machining center (the spindle is in a vertical state in the space), a horizontal machining center (the spindle is in a horizontal state in the space), and a composite machining center (the spindle can be converted vertically and horizontally). Figure 14-26 shows the boring and milling machining center. Figure 14-27 shows the box parts processed by the boring and milling machining center.
Features of boring and milling machining center:
(1) Milling, boring, drilling, expanding, reaming, thread processing and other processes can be completed in one clamping;
(2) There are many functions of tool change and tool selection, and its productivity and degree of automation are very high;
(3) For a boring and milling machining center, there can be 3-6 motion coordinate axes.
2. Turning center
Turning center is a CNC lathe equipped with a tool magazine and an automatic tool changer. It has more motion coordinate axes and has the most powerful functions than CNC lathes. It is a high-precision and high-efficiency automatic machine tool for processing rotary parts such as shafts and discs.
Some special machining surfaces on rotary parts cannot be machined on general CNC lathes, such as axial vertical holes, grooves, eccentric holes, etc. This kind of machining also needs to be carried out on other machine tools (such as milling machines, drilling machines, etc.), while the rotary body It is difficult to locate and clamp on these machine tools, the productivity is reduced, and the accuracy is not easy to guarantee, which increases the processing cost of the workpiece. Therefore, in order to meet the processing needs of shaft and disc parts, on the basis of CNC lathes, a high-automation, high-efficiency, and high-flexible lathe equipment-turning center is developed on the basis of CNC lathes, as shown in Figure 14-28. Shown is the turning center and its processed parts.
Features of turning center:
(1) The turning machining center is used to process various revolving surfaces of parts, and can process internal and external cylindrical surfaces, circular cone surfaces, spherical surfaces, revolving surfaces, various threads, etc.
(2) The machining process range of the turning machining center is wider than that of a CNC lathe. It has an additional C coordinate axis, which can process transverse holes, grooves in various directions, eccentric holes, etc. on the rotating body.