An Investigation Of Optimal Tool Sequence Selection For Pocket NC Machining

During the investigation of die-pocket NC machining, the issue that appropriate tool sequence selected automatically should be considered first. The selection of cutting tools is a complicated and optimal process, which is affected by many factors. The present CAD/CAM systems still require processors to select tools and cutting parameters manually. Subsequently, the processors produce CLSF files and NC machining programs by using the module of postprocessor. The quality of NC programs depends too much on the user's technique and experience, which are prone to cause low efficiency. The cutting tools not only need the capacity in metal removal processes, but also are optimal ones under optimized objectives. Accordingly, it is necessary to optimize cutting tools before cutting the parts, which could let processors lack of experience and technique edit high- efficiency NC programs.Rough cut is one of the most important stages in NC machining. Its main function is to remove redundant material from the workpiece in great quantity, and only reserve appropriate part stock which will be removed by semi-rough and fine cuts. In fact, approximately 70% of raw materials will be removed in the step of rough cut when complicated dies/moulds and parts are machined by NC machines, so rough cut consumes plentiful of time.Consequently, during the rough cut of pocket machining, it is significant to select cutting tools aimed at the lowest time-based production cost ,which can shorten processing time ,improve productivity and reduce production cost.In brief, firstly, this paper introduces CAD/CAM technique. Secondly, it develops a cutting tools system based on die/mould pocket NC machining. To attain the shortest-path in the single-source, directed, acyclic graph can be obtained by employing Dijkstra' algorithm, we can obtain optimal tools combination, corresponding cutting parameters and the minimal machining cost. Lastly, we can develop NC G&M codes byusing high CAD/CAM software------UG, and simulate machining by using NCprocessing emulator system (NCEdit) developed by ourselves.