Stability Analysis and Structure Optimization of Unequal-Pitch End Mills

Abstract

The damping performance of unequal tooth milling cutters is controlled by the pitch parameters. How to improve the vibration damping and dynamic balance of milling cutters needs to be further studied. This paper analyzes the pitch angle through the stability of the lobe diagram and the spectral characteristics, and unequal-pitch end mills with asymmetric structure were determined to have better cutting stability. Due to the principle error of the asymmetrical tool, dynamic balance accuracy is poor. The dynamic balance of the tool is analyzed, and the centroid model of the tool is established. In order to improve the dynamic balance accuracy of tools, the parameters of the groove shape are analyzed and optimized, and balance accuracy is improved. Through modal and milling-force analysis, the relative vibration displacement and cutting force of the optimized tool were reduced by 17% and 10%, respectively, which determined that such tools have better dynamic performance. Here, unequal tooth end mills could reduce vibration and had higher accuracy in dynamic balance by adjusting the parameters of the pitch angles and chip pockets, so that the tool could have higher cutting stability.

Design and analysis of structure for milling OCr13 stainless steel with unequal tooth pitch plunge milling tool

“…In 2016, Lu Yanxin [8] obtained that unequally spaced tools can disperse the milling force frequency by frequency domain analysis of the milling force, and then obtained that unequally spaced tools can suppress vibration. In 2021, Nie Wanying et al [9] proposed that the asymmetric structure of unequal tooth pitch end mills has better cutting stability, the groove parameters were analysed and optimized to improve the balance accuracy, and the relative vibration displacement and cutting force of the optimized tool were reduced by 17% and 10%, respectively, by modal analysis and milling force analysis.With the improvement of automatic processing technology, higher requirements are put forward for tools, and the cutting performance of tools directly affects the quality and efficiency of product processing. At present, the main applied analysis methods are fuzzy evaluation method, finite element method, etc.…”

“…In 2016, Lu Yanxin [8] obtained that unequally spaced tools can disperse the milling force frequency by frequency domain analysis of the milling force, and then obtained that unequally spaced tools can suppress vibration. In 2021, Nie Wanying et al [9] proposed that the asymmetric structure of unequal tooth pitch end mills has better cutting stability, the groove parameters were analysed and optimized to improve the balance accuracy, and the relative vibration displacement and cutting force of the optimized tool were reduced by 17% and 10%, respectively, by modal analysis and milling force analysis.…”