Modeling And Analysis Of Hydraulic Actuators Of High-power Shifting Fork Underwater Valve

Valve is the most important fluid medium control equipment in the field of process industrial automation.Valve actuator is the key driving device to control valve opening and closing.The deep water valve actuator is mainly driven by hydraulic pressure,which has high reliability requirement for long time stable operation under complex service conditions.Combined with the actual engineering requirements of wuzhong instrument co.,LTD.,this paper introduces a hydraulic actuator of single-dial fork underwater valve,establishes a three-dimensional model,and carries out simulation and optimization analysis on the parameters affecting the output torque characteristics,so as to help enterprises improve the design level of key components of the valve.First,the system analyzed the structure characteristics of the actuator,the suitable operating mode and working principle,this paper introduces a 500 m deep water single-acting piston hydraulic actuator,the single fork underwater hydraulic valve actuator parts of structure design and checking calculation,using Solid Works software preliminary established a three-dimensional model of the valve actuator underwater.Secondly,according to the working mechanism of the actuator,the mechanism modeling method is used to model the actuator.Through the force balance equation,the relationship between the moment arm,the piston area,the spring stiffness and the torque is obtained.The influence of the actuator on the output torque in the process of the key parameter change was obtained by simulation in MATLAB/Simulink software.Finally,fmincon(),an optimization tool of MATLAB,was used to optimize the design of spring and hydraulic cylinder.In the absence of sufficient given conditions,the design was carried out with the help of multi-parameter optimization ideas.According to the characteristics of the model,the optimization design program was prepared to complete the optimization design of spring and hydraulic cylinder.The finite element analysis of the optimized model is carried out and the output torque is estimated by simulation.Conclusion:when the diameter of the moment arm and piston becomes larger,the output torque of the actuator becomes larger and the spring stiffness increases.Under the same working conditions,more hydraulic pressure is needed to open the valve.If the valve is too small,it will not meet the working requirements.After optimization,the total weight of actuator spring was reduced by 8%,and the total volume of hydraulic cylinder components was reduced by 23%.The optimized output torque than the former reduces the 250 nm,the optimized actuator each parts and maximum stress reduced,and the maximal displacement reduced 22.1 mm,on the premise of guarantee the normal work of the actuator can,avoid excess torque caused by resources waste,make the organization become more compact,improves the executing agency work stability,prolong the service life.