A New Approach to Planning Plungers Paths for Efficient 2½-Axis Computer Numerically Controlled Plunge Milling of Complex Pockets With Islands

Abstract

Plunge milling is an effective roughing operation, especially in pockets roughing, because it can efficiently remove a large amount of stock material without high manufacturing costs. However, plunge milling of complex pockets with islands, whose boundaries could be designed with free-form curves, is quite challenging for multiple plungers have to be used including small plungers to cut necks between islands and their plungers paths are expected to have fewer times of plunging and shorter travel to achieve efficient machining. Unfortunately, little research on this topic was carried out in the past, and the challenge has not been addressed yet. In this research, a new approach is proposed to generate plunger paths for efficient plunge milling of the complex pockets. Its main features include (1) packing plunger circles at a minimum number of locations inside the pocket for fewer times of plunging, (2) placing plunger circles to cover the areas enclosed by the afore-packed circles to clear out the interior pocket material, and (3) planning the shortest paths to connect plunger locations for less traveling time. The advantages of this new approach over the overlapped circles filling (OCfill) and the Catia methods are demonstrated with two examples, and it can be directly used for pocket plunge milling in industry.