Design and experimental investigation of a parallel flexure hinge-based 3D elliptical vibration-assisted cutting mechanism

3D elliptical vibration-assisted cutting (EVC) is a method for rapidly creating ultra-precision free-form surfaces with features at the micro-scale, which have a wide array of industrial applications. Displacement coupling and low stiffness limit the applications of current 3D EVC mechanisms in machining difficult to cut materials and precise micro-features. To overcome these limitations and improve overall performance, an innovative 3D EVC mechanism with a parallel layout with flexure hinges will be presented. The mechanism was specifically designed to be capable of generating decoupled output displacements in three directions and assuring high stiffness. An analytical model of the mechanism's kinematics will be formulated to facilitate the prediction of the loci of the tooltip and design and realization of the prototype device. The vibration characteristics of the mechanism were verified through both finite element analysis and experimental modal analysis using swept sine testing. To validate the machining performance of the mechanism, two groups of micro-texturing turning and simulation experiments were performed. The performance tests and comparison results between the generated and simulated micro-textures indicate that the proposed 3D EVC mechanism is capable of generating different micro-feature shapes.