Approach to realization of highly-efficient deep groove milling

- Derivation of critical immersion angle for suppression of mode-coupling chatter vibration -

Abstract

In the recent years, the demand of lighter-weighted and thinner parts has increased in the automotive and aerospace industries. For the mass production of these parts, dies and molds with deep and narrow grooves are needed. However, in order to manufacture these dies and molds, slender end mills projected out long are needed which causes both mode-coupling and regenerative chatter vibration severely because of its low rigidity. Therefore, cutting is performed at a low efficiency, being the bottleneck of the manufacture of dies and molds. In this research, a novel method is proposed for highly efficient deep groove milling, which utilizes variable pitch/helix end mills for suppression of regenerative chatter and special tool paths, such as trochoidal paths, for suppression of mode-coupling chatter by limitation of the immersion angle. Here, the critical immersion angle is derived theoretically, and experiments are performed to validate this angle and find future possibilities in highly-efficient deep groove milling.