Research On Sequence Planning Method Of Five-axis Linkage Material Adding And Reducing Hybrid Machining

Traditional 3D printing methods,when dealing with complex structural parts that need to be reduced,generally carry out the overall additive processing first,and then cut after the additive is completed.However,for some specific parts,there is a problem that the cutting head can not penetrate into the interior of the part,resulting in some areas of the part can not be cut.Therefore,for complex structural parts,thesis proposes a five-axis linkage mixed machining sequence planning method to ensure that there will be no tool collision interference in the process of adding and subtracting materials,so as to meet all processing areas of the parts and effectively improve the efficiency of mixed machining.The main work of thesis is as follows:(1)The pre-processing algorithm of five-axis combined additive and subtractive processing is studied.In order to solve the problem of STL model data redundancy,the3 D part model is preprocessed,and the topological structure of the point,line and surface relationship of the triangular surface is established.In order to solve the problem of tool accessibility in the process of mixed processing,thesis adopts the 3D printing method of equal thickness,and obtains the spindle of the part based on the section of the part after stratification.(2)The tool accessibility model of five-axis linkage mixed processing with increasing and decreasing materials is established.Aiming at the problem of tool collision interference that may occur in five-axis combined machining,a simplified tool model was proposed for printing head and cutting tool,and the tool collision interference algorithm was studied.The tool accessibility model was obtained,and an improved tree-shaped bounding box structure was proposed to improve the solving efficiency of the model.(3)The sequence planning method of five-axis combined additive and subtractive processing was studied.A five-axis linkage mathematical model for sequence planning of additive and subtraction machining was proposed.The structural decomposition of the parts in the process of additive and subtraction machining was carried out based on iterative method,and a method for sequence planning of additive and subtraction machining was established based on greedy algorithm to obtain the optimal sequence of additive and subtraction machining.(4)Based on the above research,Visual Studio platform and C++ language were used to develop a simulation platform for five-axis combined additive and subtractive processing,and the sequence planning method of five-axis combined additive and subtractive processing proposed in thesis was verified through examples.