Research On Vector Planning Algorithm Of Five-axis NC Machining Tool Axis For Complicated Surfaces

In recent decades,with rapidly development of the China modern manufacturing industry,so the demand for industrial products with complex curved surfaces has greatly increased.Because the severe curvature change of complex surface-like workpieces,the processing difficulty is increased,and the requirements of CNC machining technology are increased.Therefore,the processing of complex curved surfaces has always been a difficult problem in the CNC machining manufacturing industry.At present,the mainstream CNC machining technology includes traditional three-axis CNC machining and five-axis CNC machining with higher degrees of freedom.As the five-axis CNC machine has two degrees of freedom more than the three-axis CNC machine,it makes the tool obtain a higher spatial variable range,which improves the adaptability of the tool to the complex surface forming process,and is more conducive to the processing of complex geometric shapes.However,with the increase of the degree of freedom,the planning of the cutter axis vector has increasingly influence on the processing quality and processing efficiency of the machined surface.Aiming at this problem,this paper gives a five-axis CNC machining cutter axis vector planning algorithm for complex curved surfaces.By rational planning of the cutter axis vector,the tool path with high continuity and smoothness can be obtained,which improves the complex surface Processing quality and processing efficiency.Firstly,the basic concepts of five-axis CNC machining are introduced,and the advantages of five-axis CNC in milling machining complex surfaces are discussed.At the same time,the geometric properties of complex surfaces and the theoretical basis of tool path planning are expounded,which provides theoretical support for five-axis NC machining tool path planning and cutter axis vector planning.Secondly,propose a cutter axis vector planning method based on tool attitude control.after analyzing the existing cutter axis vector planning method,it is found that the planning scheme of the cutter axis vector for the five-axis milling process is mainly based on the smoothness of the cutter axis vector,the two are not taken into consideration,and the maximum processing efficiency is considered little,so this paper considers the maximum processing efficiency,describes the influence of tool attitude on the processing bandwidth,discusses the relationship between the optimal tool attitude and the processing bandwidth,proposes the theoretical optimal tool attitude angle,and completes the initial cutter axis vector planning.However,due to the complexity of the machined surface,the cutter axis vector changes greatly when the surface curvature changes greatly,which makes the cutter axis vector change are not smooth on the same track line,affecting the processing quality of the surface.Therefore,it is necessary to optimize the obtained initial cutter axis vector,it can ensure the processing efficiency of the complex surface and obtain a smoother,cutter axis vector.Then,The optimization of the cutter axis vector based on nonlinear error is proposed.the causes of nonlinear error is analyzed in the five-axis NC machining process,and established the relationship between the rotational motion axis and the nonlinear error.The angle of motion to control the nonlinear error to achieve the purpose of optimizing the cutter axis vector,so ensuring the machining accuracy of the workpiece.Finally,the effectiveness and rationality of the proposed method are verified by MATLAB software.Compared with the cutter axis vector generated by the traditional preset cutter axis method,the method has higher processing efficiency.It is optimized for the initial cutter axis vector to reduce the variation of the cutter axis vector.It can obtain better smoothness,which reduces the problem that the surface machining quality is not high due to the unsmooth vector of the cutter axis,it can improve the processing quality of the surface.The nonlinearity error is controlled by limiting the angle of motion of the rotating shaft to ensure the machining accuracy of the workpiece.