A chatter-free pocketing routine for any two-and-a-half-dimensional pocket with islands.

摘要

Chatter has always been a significant problem in high speed, high power machining. For the purpose of chatter avoidance, the primary parameters are the axial and the radial depths of cut which are decisive in the tool path optimization. The acceptable (chatter-free) axial and radial depths of cut change depending on the dynamics of the machine tool, the direction of cut, and the mode of milling (up or down milling). The relationship of the above parameters has been incorporated to form a database by other collaborators in the Machine Tool Laboratory at the University of Florida.; The pockets used in this work may have complex 2{dollar}1over2{dollar}-dimensional geometries and may include multiple islands. Two main approaches have been developed to achieve the chatter-free routine. At first the optimum radial and axial immersions would be determined according to the database and the pocket geometries. Secondly, the tool path is arranged using the optimum immersions to achieve the best metal removal rate without the occurrence of chatter. In the optimization process, different radial immersions may be selected for different machining directions. This feature is unique since other pocketing routines can only choose the same immersion for all machining directions. Therefore, the machine would not use all of its power capabilities, since the smallest immersion has to be selected if those routines are used.; This work also outlines a complex general tree data structure, the implementation of geometric modelling techniques into programming, and the method to incorporate the new routine into CATIA, a widely used CAD/CAM package. Finally, a processor is provided to established a link between CATIA and an NC machine.; Several examples are used to illustrate the resulting tool paths from the new routine, and comparisons are made between the actual parts machined by tool paths resulting from the new routine and from the original pocketing routine from CATIA.; This work presents a new type of pocketing routine which would reduce the manufacturing time and increase machining quality and tool life.