Optimization Design And Simulation Analysis Of High-speed On/Off Valve With Low Power, Large Flow Rate

The high-speed on/off valves are pneumatic components connected to the controller, whichcan make gas switching. Their ports are controlled by digital volumes. They can replace theservo valves because they have the similar linear characteristic under PWM mode. Andcomparing with servo valves, they have other advantages of small size, low cost, simplestructure, rapid switching and strong anti-pollution. So they are widely used in the field ofmodern industry and have come to a hot topic of research on the pneumatic technology.The valves are rarely reported which provides above700l/min of low rate at standard airconditions but the shifting time of is below10ms. So these on/off valves are deeplyresearched in the thesis based on mathematical modeling, simulation and experimental study.Firstly, a2/2pneumatic high-speed on/off valve is presented. And its armature is fixed by tworubber diaphragms. Then FEM (Finite Element Model) of the solenoid in this valve andFEM-LPM (Lumped Parameter Model) of this valve are determined. The influences of differentfactors of this valve are analyzed in detail and some conclusions are presented for theimprovement of performance of on/off valves. Lastly, the structural parameters of this valve areoptimized. The simulation and experimental results show that the maximum flow rate is720L/min; the switching time is only9.5ms after optimized. The main content of each chapteris summarized as following:In chapter1, the background and significance of this research are introduced. The researchstatus is analyzed. The keys and main research work of this thesis are developed.In chapter2, from the mass flow rate and the dynamic response characteristics, thestructure of this valve is analyzed and designed. The method of armature fixed is presented andthe basic structural parameters are identified.In chapter3, the action mechanism of the structure of static core, armature and coil on theE-type solenoid are analyzed in detail with FEM, and the influencing rule of performance of thesolenoid. Lastly, the solenoid structural parameters are optimized.In chapter4, formulas for steady gas flow force on this valve are derived and presentedwith FEM. Based on FEM-LPM, the effect of the spring stiffness coefficient, air pressure andvoltage for the dynamic performance is discussed. Lastly, the driving parameters are presented.In chapter5, the basic principle of flow rate characteristic test system and the shifting time test system are introduced. Bases on these systems, the flow rate and the switching time of theproposed valve are measured and compared with the simulation results. The result indicates thesimulation models are correct.In chapter6, the full texts of the main work are summarized and the further research workis prospected.