A study on machining error prediction model of precision vertical grinding machine based on the tolerance of key components

Tolerance design of key components is an effective method to improve the machine tools accuracy. Currently, tolerance design highly depends on the personal experience, which often subjectively determines the machine tool accuracy and also increases the manufacturing costs. To avoid the phenomenon, a machining error prediction model (MEPM) assisting tolerance design is proposed and experimental verified based on a precision vertical grinding machine (PVGM). Firstly, the mapping relationship between the tolerance parameter and geometric error of key components is obtained as the superimposed Fourier series. Subsequently, the volumetric error model including geometric errors is established by the homogeneous transform matrix and multi-body system theory. Based on a typical workpiece, a tolerance-based MEPM is obtained by integrating the ideal machining path. Finally, a grinding test on PVGM is conducted to validate the MEPM. The results show that the predicted roundness of three positions is 3.033 μm, 2.905 μm, and 2.774 μm, respectively, and the measured roundness are 3.163 μm, 2.980 μm, and 2.904 μm, respectively. The error between PVGM predicted and measured roundness is not more than 5%. The MEPM is important for assisting the tolerance design and improving the machining accuracy in the machine tools.