The Measurement Research Of Rotary Axes’ Static Errors Based On Five-axis Cnc Machine Tool With Touch-trigger Probe

Machine tool is a symbol of a country’s manufacture level, which reflects the level of a country’s industrial development to a certain extent. For the five-axis NC machine tool, the research on the linear axes’ errors has become more and more mature. Now the important factor that affects the machining accuracy of five-axis NC machine tools is the errors of the rotary axes. Therefore, this dissertation focuses on the modeling and measurement of the rotary axes’ static errors.In this dissertation, a comprehensive model is established based on the coordinate transformation matrix of the five-axis NC machine tool. Then based on measurement method of five-axis CNC machine with dual rotary tables’ static errors, we propose the measurement method of the other two types of five-axis NC machine tools’ static errors, the TTTRR and RTTTR. The measurement of the three kinds of machine tools’ static errors is based on the comparison between adding static errors and without static errors, and we can derive the relationship between the variation of the coordinates and static errors. Different types of static errors’ values of rotary axes have different influence on the actual outputs. Position error can cause the offset of coordinate system, while angle error can cause the rotation of coordinate. According to this principle, we can analyze the influence of the single position error and the single angle error respectively, and establish the relationship between the static errors and the actual output values.In the measurement process, measurement tools we used are touch-trigger probe and gauge block. The probe is simple and easy to operate, and its application is wide, what’s more, its price is not high. The gauge block is a measurement tool with high precision. In order to understand the geometric relations and calculate easily, the gauge block should be placed on special position, and the upper face’s center point of the block should be in the position of X axis or Y axis.When we measure static errors of TTTRR and RTTTR, except for using normal angle, we also propose to add special angle during measuring coordinate values.Based on the theoretical analysis and simulation above, this paper add different values’ static errors to five-axis CNC machine tools by using 3D simulation software, and verify the validity of modeling, measurement and identification.