Otimização do fresamento de roscas internas por interpolação helicoidal

摘要

In machining of internal threads, dedicated tools, known as taps, are needed for eachprofile type, diameter, and low cutting speed values are used when compared to mainmachining processes. This restriction in the cutting speed is associated with the difficulty ofsynchronizing the tool s rotation speed and feed velocity in the process. This fact restricts theflexibility and makes machining lead times longer when manufacturing of components withthreads is required. An alternative to the constraints imposed by the tap is the thread millingwith helical interpolation technique. The technique is the fusion of two movements: rotationand helical interpolation. The tools may have different configurations: a single edge ormultiple edges (axial, radial or both). However, thread milling with helical interpolationtechnique is relatively new and there are limited studies on the subject, a fact which promoteschallenges to its wide application in the manufacturing shop floor. The objective of thisresearch is determine the performance of different types of tools in the thread milling withhelical interpolation technique using hardened steel workpieces. In this sense, four toolconfigurations were used for threading milling in AISI 4340 quenched and tempered steel (40HRC). The results showed that climb cut promoted a greater number of machined threads,regardless of tool configuration. The upcut milling causes chippings in cutting edge, while theclimb cutting promotes abrasive wear. Another important point is that increase in holediameter by tool diameter ratio increases tool lifetime