Research And Development On NC Automatic Programming System For Complex Insert Of Cavity/Core Mould

The automation of NC programming can greatly improve the efficiency of mould machining process,and it is one of the most important prerequisites for achieving automation of NC processing.Complex insert is the most important forming components in cavity/core mould with complex geometrical shape and many surfaces.Traditional interactive CNC programming is not only inefficient,complex and mistakable,but also needs the programmers have highly professional skills.Therefore,it restricts the overall efficiency of complex insert's design and manufacture.In order to overcome it,this paper presents an automatic programming system for complex insert,which can realize the automatic programming of complex inserts and improve the efficiency and accuracy of NC programming effectively.The main research contents are as follows:Firstly,this paper combines rule-based feature recognition and graph-based feature recognition to design the feature recognition and parameter extraction algorithms for several processing features:(1)This paper uses attributed adjacency graph to abstract features and adopts rule-based feature recognition to design feature recognition and parameter extraction algorithms of step-face which can recognize and group the step-face features in complex insert and extract parameters such as cutting levels,cutting depth,etc.(2)This paper uses the processing geometry of runner faces and designs feature recognition and parameter extraction algorithms for runner faces.Adopting rule-based feature recognition to esign recognition algorithms for planes to be processed and profile blending.(3)Extracting elongation of cutter from cutting level parameter in depth processing operations to decide which cutter to use.Secondly,getting knowledge by methods of analyzing large numbers of cases,the system designs a NC processing knowledge base to manage processing plans of complex insert,and regards it as the core to build the background database system which includes all the settings of parameter.Then the system matches the best process planning and operation parameters from the background database by the recommendation way based on cosine similarity.Finally,this paper develops the programming system on the platform of Unigraphics NX and realizes the automation of all the programming processes.By application in relevant company,it proves that the programming system can reduce the programming time by 60%,reduce the error rate by 55% and improve the efficiency of NC programming greatly.