Precision execution standards and definitions for CNC precision machining plants

How to look at the technical level of CNC precision machining plants, the most intuitive feedback is its machining efficiency and repeated positioning accuracy. Assuming that the repeatability of the machine tool can achieve the standard of 0.005mm, then this is a high-precision machine tool, but if it achieves less than 0.005mm, it is an ultra-high-precision machine tool. In addition to the system, the accuracy of the machine tool also requires hardware. The best screw and bearing to match.

When talking about the 'precision' of CNC machine tools, it is necessary to clarify the definitions and calculation methods of standards and indicators. Some CNC machine tool manufacturers in Japan usually use JISB6201 or JISB6336 or JISB6338 standards when declaring 'accuracy'. JISB6201 is generally used for general-purpose machine tools and general CNC machine tools, JISB6336 is generally used for machining centers, and JISB6338 is generally used for vertical machining centers. The three standards mentioned above are basically the same in defining position accuracy, we take ISB6336 as an example, because on the one hand this standard is relatively new, and on the other hand, it is slightly more accurate than the other two standards.

European machine tool manufacturers, especially those in Germany and Switzerland, generally adopt the VDI/DGQ3441 standard. American machine tool manufacturers usually use the NMTBA (NationallMachineToolBuilder'sAssn) standard (the standard originated from a study by the American Machine Tool Builders Association, promulgated in 1968, and later revised).

The standards we mentioned above are all related to ISO standards. Machining center plus [the dimensional accuracy and shape and position accuracy of typical parts as an example to compare the level at home and abroad, the domestic level is roughly 0.008 ~ 0.010mm, and the international advanced level is 0.002 ~ 0.003mm.

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Although the development of China's machine tool manufacturing industry has ups and downs, it has always paid more attention to CNC technology and CNC machine tools, and has strong market competitiveness. However, in the aspect of medium and high-end CNC machine tools, there is still a big gap with the development of some advanced products and technologies abroad, most of which are in the technology tracking stage

CNC precision Machining currently refers to the size and position accuracy of 0.01 ~ 0.3μm, the shape and contour accuracy of 0.003 ~ 0.1μm, the surface roughness of steel parts

Ras0.05μm, copper parts Ra≤0.01μm. The domestically developed CNC precision machining lathes and CNC milling machines have been put into production. At present, it is necessary to develop ultra-precision grinding machines and ultra-precision compound machining machine tools in terms of varieties. At the same time, it is necessary to further improve the ultra-precision spindle unit, ultra-precision guide rail pair unit, ultra-precision smooth drive system, ultra-precision contour control technology and nano-resolution CNC system. performance and speed up its engineering.

CNC precision machining is mainly used to solve the ultra-precision machining of domestic high-tech and national defense key products. Sensitive technology for tech blockade. On the other hand, the in-depth study of CNC precision machining technology, and the extension of its results will help the research and development and industrialization of CNC precision machining that requires a large amount of machining accuracy in the sub-micron level.