Abstract: A new kind of high-speed on/off valve is recommended. It has a trunk piston hydraulic gain amplifier and a high-speed on/off electromagnetic valve is used as the pilot stage. By the amplification of the second stage, the largest flow rate is more than 80 1/min. Besides the high flow rate, the digital valve has a high switch speed. The on time of the second stage spool is less than 1 ms, and the off time less than 3 ms. So, it solves the contradiction of high speed and high flow rate. The PWM control method and reduce amplitude double voltage driving technique are used in the digital valve controller. The time of the accelerate voltage and amplitude of the working voltage can be optimalized. So, the switching speed of the electromagnetic valve is optimalized.

Key words: Digital valve, High-speed on/off, Trunk piston hydrauli gain amplification PWM Reduce amplitude double voltage driving