Four-axis Complete Machining Process Planning And Tool Path Post-processing Of Complex Curved Impeller

The impeller as an important part of transmitting power,is widely used in aviation,aerospace and other fields,it usually has the characteristics of thin blades and large distortion.It is a typical difficult-to-machine part with complex curved surface.Its processing quality directly affects the aerodynamic performance and mechanical efficiency.In order to improve the machining efficiency and accuracy of the impeller,this article studies the technology,tool path,post-processing and simulation of the impeller for the four-axis CNC machine tool.After analyzing the structural characteristics and machining difficulties of the impeller,the four-axis machining process flow of the impeller is developed according to the machining technical requirements.The tool path trajectory algorithm for four-axis machining of impeller is studied,and the algorithm for maintaining constant cutting force of the tool in finishing machining is designed.The tool path trajectory of each machining stage is generated based on UG CAM module.The kinematic chain of the four-axis vertical machine tool is analyzed and its post-processing algorithm is studied,then the formula for calculating the rotation angle of the rotating shaft is derived.Based on the UG NX/Post Builder module,the dedicated post processor of the Liwei V-30 i vertical four-axis machine tool is developed and through post-processing,the tool position source file is converted into the NC program that can be recognized by the machine tool.Based on the VERICUT software,the machining simulation of the blade is realized,and the simulation result is compared with the design model.There is no overcut and undercut,which verifies the correctness of the tool path and NC program.At the same time,the factors affecting cutting force in finishing are monitored and optimized,which proves the rationality of the constant cutting force algorithm.The cutting speed is optimized and the processing time is shortened by about 13.09% after optimization,which improves the efficiency of blade processing.Finally,the aluminum alloy blade is actually milled on the four-axis machine tool and the test is in compliance with the processing requirements,which further verifies the feasibility of the machining plan determined in this article.Therefore,it is of great practicalsignificance to develop the machining potential of four-axis machine tools and reduce the machining cost of impeller.