Full simulation of a piezoelectric double nozzle flapper pilot valve coupled with a main stage spool valve

This paper develops a detailed simulation model, realized by the software Simscape, which can be a powerful tool to analyze the performance of a double nozzle flapper valve actuated by a piezoelectric ring bender. The particularity of this valve is that the use of the torque motor and flexure tube is avoided, thus reducing the complexity, manufacturing time and cost of the valve assembly. The model accounts for all the real phenomena present in the valve, such as fluid compressibility and fluid viscosity. The viability of the valve concept is validated by step tests simulated at different valve openings. It is shown that the response time obtained for a supply pressure of 210 bar and necessary to reach 90% of the maximum opening degree (corresponding to a maximum spool position of 1mm and maximum flow rate of 60 l/min) is only 6 ms, which is comparable with typical commercially available double nozzle flapper valves, but with the advantage of having removed critical components such as the torque motor and the flexure tube.