Design of High-Performance Fast Tool Servo System Based on Two-Way Piezoelectric Ceramics

To overcome the loss of the working stroke caused by large stiffness flexible hinge in the single piezoelectric actuator Fast Tool Servo System (FTS), this paper presents a design method of large stroke FTS driven by two-way piezoelectric ceramics. First, the mechanical system is modelled and analysed to get the effect of mechanical parameters on the system response. Then based on the effect and guide means for stiffness requirements of compliant guide mechanism, we use compensating the flexibility matrix method to design a double parallelogram mechanism. Finite element simulation results show that the compensation method can significantly reduce parasitic displacement (reduced from 33.250&mgr;m to 4.545&mgr;m). The double parallelogram mechanism is completed based on the method of parallel symmetrical design. The results show that the stiffness in function direction is the small, the ratio of the stiffness in non- function direction to function direction is large, which ensure high accuracy and large stroke linear movement of the tool.