Development of a novel XZ workpiece vibration generator for cooperative vibration cutting of hierarchical grating structures

Abstract

This paper presents a novel piezoelectrically-driven XZ workpiece vibration generator (WVG) enabling the cooperative vibration cutting, which serves as a promising alternative for machining hierarchical micro/nano-structured surfaces. The WVG features a double symmetric configuration and the integration of two flexural lever mechanisms and an eight legs Z-shaped mechanism for dual-stage displacement amplification as well as decoupled 2D motion modulation. By utilizing the matrix-based stiffness modeling and Lagrange principle with motion properties of the piezoelectric actuators treated as boundary conditions, the kinetostatics and dynamics of proposed WVG are analytically described and verified using finite element analysis. The experimental performance assessments of proposed WVG show a working space of 44.7 μm × 38.9 μm with a positioning resolution less than 20 nm in both motion directions. The capability of delivering harmonic elliptical as well as non-harmonic triangular and trapezoidal motion trajectories has been demonstrated. In addition, the developed WVG was integrated into a newly cooperative vibration cutting system for one-step machining of hierarchical grating structures. The cutting performances of three kinds of hierarchical grating structures demonstrate not only the feasibility and flexibility of proposed cooperative vibration cutting process but also the accuracy and robustness of the developed WVG mechanism.