Kinematics Modeling And Solution Of Axis Offset Five-axis Machine Tools

The processing requirements of complex parts make five-axis CNC machine tools become significant in the manufacturing industry.Modern machining not only requires more and more precision for machine tools,but also requires a variety of machine tools.At present,the research on post-processing algorithms of orthogonal type machine tools has been matured at home and abroad,but the motion modeling of non-orthogonal machine tools is still limited to specific types of machine tools,and there is a lack of comprehensive research on the case where both the translational axis and the rotational axis are non-orthogonal axes;and the compensation of structural errors of machine tools that affect machining accuracy is also insufficient in motion modeling.At the same time,the research on post-processing corner selection methods is also lacking.In this paper,for the series of problems,the non-orthogonal machine tools and machine tools with structural errors are classified into the axis offset type machine tools,and the offset is unified.At the same time,the motion modeling algorithm for this type of machine tool is proposed,the solution and selection method of the amount of motion is described.The main work of the thesis is as follows:(1)Analysis of the rotation axis,translation axis and spindle axis offset for non-orthogonal machine tools and machine tools with structural errors.According to the similar definition method in the reference coordinate system of the axial direction,both types of machine tools are regarded as the axis offset type machine tool,and the calculation method of the offset of each motion axis is explained,and the expressions of each offset are summarized.(2)The initial position of each component is described in the state of tool setting.According to the analysis of the movement axis offset and the definition of the offset,the axis offset motion model of the rotation axis,translation axis and main axis is established.The topology of three typical types of machine tools is used to model the motion of the axis-offset machine.The modeling method has good versatility.One of the types of machine tools is taken as an example to illustrate the solution method of the rotation amount and the translation amount.(3)According to the relationship between the tool position data and the machine tool movement quantity,the rotation quantity is used to generate two sets of solutions.Based on the machine's stroke limit,motion continuity and absolute value optimization,a number of factors are proposed.A comprehensive comparison of the two-column parallel selection method,which breaks through the limitations of the dominant interval and improves the processing efficiency and processing continuity.In this paper,the correctness of the axis offset algorithm is verified by the simulation results of the S-piece and the tool spiral groove by the five-axis CNC milling machine and the five-axis CNC grinding machine with axis offset.The verification results show that the method can be applied to the motion modeling of any type of axis offset type machine tool,and the structural error of the machine tool can be compensated in the post algorithm to improve the machining accuracy.