| With the continuous development of China’s naval equipment,heavy-duty high-precision marine equipment has begun to receive more and more attention.The lifting platform is an important device for transporting weapons and equipment for large ships.Its performance is directly related to the operational efficiency of ships..The core electro-hydraulic servo valve of the lifting platform control system mostly adopts the multi-stage control method of the pilot valve,which is expensive and cannot meet the large flow control requirements of the marine heavy lifting platform.Therefore,this paper designs a large-flow direct-acting servo valve based on hydraulic motor control,which eliminates the complicated pilot multi-stage valve control mode,effectively increases the output flow of the servo valve,and also improves the anti-pollution of the servo valve.Capacity and stability saves manufacturing costs.This article mainly carried out the following work:Firstly,in view of the complicated control method of traditional servo valve,poor pollution resistance,and the inability to meet the requirements of large flow control of marine heavy lifting platform,a large flow direct acting servo valve based on hydraulic motor control is designed.The parameters are designed and calculated.By increasing the flow area of the valve port to realize the large flow characteristic of the servo valve,the hydraulic motor directly drives the valve core to reduce the complexity of the spool driving device.Secondly,the finite element model of the servo valve is established by ANSYS Workbench software and the strength analysis is carried out.The stress distribution and deformation of the servo valve are obtained.The structural parameters such as the wall thickness of the servo valve body and the diameter of the outer diameter of the valve are used as design variables.Taking the maximum stress and displacement of the servo valve as the optimization target,it is calculated based on the multi-objective optimization algorithm(AMQ),and the calculation results are compared with the data before optimization.The analysis results show that the maximum stress of the optimized model is reduced by 14.3%.Then,the internal flow channel model is established.The pressure velocity map of the servo valve with different valve opening is obtained by FLUENT simulation.The curve of valve port flow and steady-state hydraulic power of the valve core is obtained,and different valve ports are analyzed.The flow field characteristics of the servo valve under opening and different inlet and outlet pressure differences,and provide a data basis for the next step of dynamic analysis.Subsequently,in order to analyze the position generated by the cavitation of the servo valve,a two-phase flow model was established.The simulation results show that the maximum flow velocity of the oil appears at the throttle orifice of the valve sleeve.When the valve opening increases to more than 30mm,the flow rate gradually becomes saturated.The cavitation phenomenon mainly occurs at the inlet throttle and with the valve port.The increase in opening gradually decreases.Finally,the valve balance force equation and flow characteristic equation of servo valve are established.Based on the equation,the dynamic simulation model of the hydraulic system of the lifting platform is established in AMEsim software.The influence of different structural parameters on the dynamic characteristics of the servo valve is analyzed.The analysis results show that when the driving motor speed is 300r/min,the valve port is fully opened for 3.8s,and the system cylinder runs smoothly,and the valve dynamic characteristics are good. |
