| 摘要 |
PURPOSE:To prevent the existence of the part not yet ground in a range surrounded by straight lines and a circle by constituting so that the distance between a plurality of closed passages can be varied along working shape and transferring a tool along a base line, when working is performed in the range by an NC machine tool. CONSTITUTION:When the inside of the range AR surrounded by an outer curve OLC is worked, the circular part A1' of the offset curve OFC is approximated to a straight line, and the range surrounded by the offset approximated to the straight line is divided into convex polygons PG1-PG3. Each center of gravity W1-W3 of the convex polygons and the middle points M1 and M2 of the respective boundary lines B1 and B2 of the convex polygons are calculated, and a base line BL is formed. Then, the straight lines L1-L14 connecting the center of gravity Wi and the tops P1-P10 of the convex polygons, and the middle points M1 and M2, and the straight lines BL1-BL4 are divided into a prescribed number of division. Then a tool is transferred along a plurality of closed passages CPT1, CPT2,... which are formed by connecting the corresponding division points on each straight line so as to surround the base line BL, and transferred along the base line BL. |
