Error Analysis Of Five-axis CNC Side Milling

Five-axis CNC machining technology plays an important role in the processing of complex parts.Especially the five-axis side milling with high machining efficiency has always been an important means of machining complex surfaces such as ruled surfaces,the research of it has also been the focus and difficulty in machining.Under normal circumstances,even the ideal side-milling in the tool position planning has an inevitable principle error.In the actual machining process,different error factors will cause more changes in the machining error.The influence of errors in the process and the proposed recommendations and control methods are very necessary,and it is also a very practical research topic.Firstly,in the case of known neutral surface discrete data points,the B-spline interpolation method is used to calculate the surface information,and the shape of the blade surface is completed,which serves as the theoretical basis and research basis for the later work of the thesis.Secondly,for the work bench five-axis CNC machine tool with two rotating axes acting on the workpiece,the machine structure is analyzed.Through the multi-body system theory and kinematics knowledge,the two kinematic chains of the machine tool are derived,and the tool kinematic chain is established respectively.The coordinate transformation matrix of the workpiece kinematic chain is obtained,and the relative transformation matrix of the two coordinate systems of the tool and the workpiece is obtained.The geometric error model of the machine tool is established based on the small angle assumption.Thirdly,by calculating the effect of positioning error on the spatial point,the method of homogeneous coordinate transformation and two-point offset is used to determine the initial location of the side milling machining in the presence of positioning error,and the cylinders under different positioning errors are discussed respectively.The machining error of the tool and the conical tool is compared with the machining error without positioning error.Finally,the nonlinear error caused by the linear interpolation of the tool during the actual machining is studied.Firstly,the enveloping surface of the cylindrical milling side milling is calculated,and then the linear interpolation error is obtained based on the iterative method.Finally,the cylindrical cutting tool cylinder is taken as an example to analyze the influencing factors and error variation of the linear interpolation error.