Machine Tool Assignment Realized by Automated NC Program Generation and Machining Time Prediction

摘要

The present study proposed a method to automatically generate a numerical control (NC) program by refer-ring to machining case data for each machine tool with only 3D-CAD models of a product and workpiece as the input data, and to select machine tools for ma-chining the target removal region among several ma-chine tools with different characteristics. The special features of the proposed method are described as fol-lows. The removal volume can be automatically ob-tained from the total removal volume (TRV), which is extracted from the workpiece and product using a Boolean operation by dividing it on the XY plane. The removal region changed according to the determined machining sequence. The conditions for machining the removal region is automatically determined ac-cording to the machining case data, which is stored by linking the geometric properties of the removal re-gion with the machining conditions determined by ex-perienced operators. Furthermore, an NC program is automatically generated based on the machining con-ditions. The machine tools for machining the target region are selected according to the predicted machin-ing time of each machine tool connected by a network. A case study was conducted to validate the effective-ness of the proposed system. The results confirm that machining can be conducted using only 3D-CAD mod-els as input data. It was suggested that the makespan would be shortened by changing the machining se-quence from the optimized machining sequence when machining a plurality of products.