Research On NC Automatic Programming System Of Automobile Panel Die Based On NX

CNC programming is an important step in the CNC machining process.CNC programming analyzes the part pattern to determine the machining process and calculate the path of the tool to obtain the tool position data.For more complex parts,NC programming can improve work efficiency,shorten the programming cycle,and improve the quality of the program by means of tool path detection,etc.,thus avoiding the scrapping of parts due to programming errors in actual production in most cases.Such as economic losses and the resulting security problems.The result of CNC programming is a key factor that directly affects the quality of part processing.Therefore,it is necessary to develop a complete and efficient CNC programming system.When programmers use the current mainstream CNC programming software,they usually go through a lot of human-computer interaction processes,so programmers need a wealth of processing experience.Moreover,with this method,not only the programming efficiency is low,but more importantly,the operation process is repeated and cumbersome,and at the same time,due to manual operation,processing scheme selection,parameter setting and the like often have errors.There are a large number of machining parts in the automobile cover mould,and the sizes are different.Different programmers may use different processing methods for the same part and the set processing parameters may be quite different.Therefore,to avoid the above situation,this paper studies a large number of automobile cover mold examples,and realizes a numerical control automatic programming system based on feature recognition under NX platform.The system starts with the overall assembly model of the mold,extracts and integrates the meaningful information of the subsequent NC programming,and integrates the information into the CAM module to realize the communication between CAD and CAM.With sharing.The automatic programming system is divided into four modules: model pre-processing module,feature recognition module,automatic programming module and machine tool simulation module.The model pre-processing module identifies the machined parts based on the assembly schedule of the mold,and positions the machined surface on the machined part with the non-machined part,and optimizes by using the octree division technique to improve the matching efficiency.The automatic recognition module uses the graph-based feature recognition method to construct the processing plane attribute adjacency map according to the set information and topology information of the model,and then decompose the adjacent graph to obtain the isolated vertex and the concave sub-feature subgraph,and the subgraph and the predefined Features are matched for recognition.Each machining feature corresponds to multiple sets of machining templates,which are set by experienced programmers.The template contains the tools used for machining,machining methods,various machining parameters,etc.,which can be set in advance before programming.Content,so as to ensure that different programmers use the same processing scheme for the same part.Prioritize these processing templates and sort them in order of priority from highest to lowest.In the automatic programming,the machining program is generated from the highest priority template,and the generated tool path is simulated by the machine simulation module.If there is a problem such as overcut or collision,the next priority template is adopted until the simulation is passed.until.The machine tool simulation module completely simulates the machine tools and tools in the actual machining to improve the accuracy of the simulation results.After the actual verification,the machining process scheme adopted by the automatic programming for the common automobile cover mold parts is basically reasonable,the accuracy of the processing program is effectively improved,and the programming efficiency is remarkably improved.