Ultrasonic vibration micro-shaping using single PZT actuator-embedded tool holder

In this study, we suggest a novel tool holder design for simple and cost-effective ultrasonic vibration shaping to provide improvements such as low cutting force, smooth chip exhaust, and better surface quality in the cutting performance. An ultrasonic vibration tool actuated by a single actuator, which was designed by asymmetrically installing a single PZT actuator inside a cylindrical tool holder, generated the synchronized two-axis ultrasonic vibration motion on the tool tip along the cutting and thrust directions. By conducting dynamic structural analysis and simulating the tool tip movement trajectory using finite element method, the resonance mode, amplitude, and frequency of the model were optimized to achieve the vibration characteristics required for precision micro-shaping processes. According to the experimental evaluations, the vibration of the tool holder was characterized by a resonance mode of 24 kHz. The cutting performance of the tool was evaluated by comparing the cutting force, machined surface, and chip shape with those using a non-vibration micro-shaping tool. The cutting force was reduced more than 90%, and the machined shape and chip exhaust were improved compared with that in conventional shaping processes.