ScholarWorks@Y-Scholar Hub

초록

This paper presents an electromagnetic active workpiece holder (EAWH) and demonstrates its feasibility for both rough-and finish-milling operations. While most research on active workpiece holders (AWHs) relies on piezoelectric stack actuators due to their compact size and high internal stiffness, their stroke is limited, and heavy-duty operation often requires large motions and high-voltage driving, which can introduce additional design challenges for an AWH system. Electromagnetic actuators (EMAs) can provide large compensatory strokes and robust high-force actuation with simple drives, but their lack of inherent stiffness has kept prior EMA-based AWHs mostly in low-force applications. To address this gap, we propose a reluctance-actuator-based EAWH that combines large stroke with high force capacity. With a stroke exceeding +/- 100 mu m and a maximum force of 3812 N in both the X and Y directions, the proposed EAWH effectively compensates for large-amplitude tool vibrations while withstanding high cutting forces during rough-milling. Rough-milling experiments show that the EAWH suppresses unstable chatter and doubles the chatter-free cutting depth compared with the uncompensated case. For finish-milling, we propose a compensation strategy targeting the forced vibrations induced by the spindle bearing retainer, and experiments demonstrate that the undesired surface marks are eliminated, reducing the surface roughness by up to 46.5%. Overall, the results demonstrate that the EAWH and the proposed strategies can support modern machining centers that integrate high-throughput roughing and surface-finish improvement under finishing conditions within a single platform.