Geometric error modeling and separating method for five-axis AC rotating and swinging head gantry machine tool

Abstract

The invention relates to a geometric error modeling and separating method for a five-axis AC rotating and swinging head gantry machine tool. The method comprises the steps that firstly, a kinematics model of the machine tool from a tool coordinate system to a workpiece coordinate system is established, then a tool nose point space error model only considering a linear axis, a tool nose point spaceerror model only considering a rotating shaft anda tool nose point space error model simultaneously considering the linear axis and the rotating shaft are established respectively, and then a linearaxis space measurement track is designed; actual space coordinates of a tool nose point under a measurement track are measured, and further separation calculation of 21 geometric errors of the linearaxis is realized; and finally, independent measurement tracks of the A axis and the C axis are designed, the rod length variation of the whole stroke in axial, radial and tangential modes are measured, a mutual relation between the sensitive directions of eight PIGE errors and the rod length variation is established, and separation of the eight PIGE errors is realized; and a mutual relation between the 12 PDGE errors and the rod length variation of a ball rod instrument is established to realize separation of the 12 PDGE errors. The method has good universality and accuracy.

Description

technical field [0001] The invention belongs to the technical field of geometric errors of five-axis machine tools, and in particular relates to a geometric error modeling and separation method of a five-axis AC rotary head gantry machine tool. Background technique [0002] Machining accuracy is a key indicator to measure the performance of CNC machine tools, and it is used to characterize the degree of deviation between the ideal machining shape of the workpiece and the actual machining shape. In the production process of the machine tool, the machining error of the parts and the error of the machine tool assembly and calibration process are finally manifested as the geometric error of the machine tool. The deviation value in the position leads to machining errors in the machining process of the parts. Therefore, a method to reduce or even eliminate the influence of geometric errors is very important to improve the machining accuracy of parts. Considering the original geome...

AI Technical Summary

Problems solved by technology

But the five-axis machine tool is not limited to these two structural forms. Taking the AC rotary head gantry machine tool as an example, the AC rotary head is directly hung on the lower end of the Z axis, the tool is fixed on the A axis swing head, and the X axis moves independently. There are obvious differences in the movement mode and the five-axis cradle machine tool, but the research on the geometric error of the five-axis AC rotary head gantry machine tool is rarely involved

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