Development of automatic system on process planning and nc program generation for turning-milling machine tool with multi turrets

This study aims to develop an automatic process planning and NC program generation system based on machining feature recognition for a turning-milling machine tool with multi-turrets. Machining feature recognition is carried out based on delta volume decomposition. A delta volume which is a portion removed by machining is separated into element shapes which are recognized as machining features. The developed system uses a CAD system (SolidWorks API) to execute delta volume extraction, delta volume decomposition, machining feature recognition, turret assignment of machining features, toolpath length calculation, machining time prediction, process plan determination, and NC program generation. The system generates various possible candidates for the machining process plan, and evaluates them based on a criterion determined by users. In this study, the shortest machining process time is provided as a user's criterion. After determining the machining plan that has the shortest machining time, the system automatically generates an NC program according to the plan. The system is applied to a turning-milling machine tool with three turrets, and an experiment using the generated NC program is conducted to confirm that the proposed system works well.