In this study, a high-speed on/off digital valve was developed for use in a hydraulic control system. The device basically consists of a poppet valve acting as the main valve, and a multilayered piezoelectric (PZT) actuator for driving the poppet valve. A hydraulic amplifier was adopted to increase the actuation of the PZT actuator to the poppet valve. A compensation mechanism was set up to reduce this temperature effect in the hydraulic actuation of the PZT actuator. This problem arises when the oil temperature increases and causes the valve displacement to fluctuate slightly. The static and dynamic characteristics of the device were investigated by experiment and digital simulation. As a result, we found that the switching time of the valve is less than 0.7 ms. Moreover, the valve can be driven by a PWM carrier wave using frequencies of up to 500 Hz . Additionally, the validity of the temperature compensation mechanism was confirmed. Hence this valve may be determined as feasible device.
#This study was conducted as cooperative research with the Department of Fluid Power Transmission and Control, University of Technology, Aachen in Germany.
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