Research On Surface Mechanism Of Test Specimen For Five-axis CNC Machine Tools

With the CNC machine tools’ rapid development trending to high-speed and high-precision, the approach, cutting test specimen to realize CNC machine tools’ dynamic accuracy detection, has drawn the attention of domestic and foreign machine tools’ manufacturers and companies. After half a century development, the test specimen has developed from the initial three-axis NAS979 part to the specimen including NAS cone frustum specimen, square pyramid specimen, China S specimen,Germany S specimen, et al, which has formed a test specimen group, the CNC machine tools’ quality can be detected approximately by processing the test specimen with various geometric characters. Generally, the specimen with different geometric characters may reflect the integrated properties of machine tools better, however, it also leads to the difficulty that it’s hard to trace and judge the single error, in other words, it’s difficult to judge the relationship between geometric characters and machine tools’ properties. So it is very necessary to extract and study single geometric character mechanism from different test specimens, which is very helpful to explore the law between geometric feature and machine motion, and to provide theoretical support for tracing machine’s defect accurately based on specimen processed. In this paper, we will worked from the common-used four specimens, the main contents are as follows:1. Analyze the modeling method, geometric and processing characters about common-used five-axis machine tools’ dynamic accuracy test specimen. The uniqueness of specimen modeling is confirmed by constructed four specimens’ 3D model, then comparing geometric features about different specimens. The acceleration for each shaft is analyzed according to the NC code, and the area on the specimen surface about machine motion under different geometric characteristics is gotten.2. Research on the relationship between geometric and cutting features. Study on the method reducing twisted angle principle error, and the machine tools’ motion state under curvature and curvature continuity separately by extracting single geometric features of each specimen. And the motion rule about each shaft is gotten during processing different geometric characteristics.3. The superior capability of China S part is affirmed by cutting and comparing the common-used five-axis test specimen(China S part and Germany S part). A new testspecimen own two typical geometric features is reconstructed, and verifying the correction of theoretical derivation according to the simulation analysis and experiment about this new specimen.