Simulation Study And Optimal Design Of The Spool With U+T Shaped Groove

The hydraulic valve is one of the basic components in the hydraulic components,and plays an important role in the hydraulic system.Its performance will directly affect the performance of the entire hydraulic system.With the continuous improvement of hydraulic technology,the requirements for the quality of hydraulic valves have gradually increased,and the influence of temperature changes on hydraulic performance has also been gradually paid attention.During the operation of the hydraulic valve in medium and high pressure,the spool will be jammed or stuck,which prevents the hydraulic system from operating normally,mainly because the viscous heating effect will occur when the oil flows through the throttle,causing the throttle valve to heat.Expansion deformation occurs,resulting in a smaller fit clearance.Therefore,studying the temperature characteristics of hydraulic valves is of great significance to the optimal design of hydraulic valves.In this paper,the U+T throttle spool valve is taken as the research object.The temperature rise phenomenon caused by the oil flowing through the throttle valve port is combined with theoretical analysis and numerical simulation.The characteristics of the oil flow field in the throttle spool valve and the deformation of the valve spool under different openings and different throttle structure parameters,and the optimal design of the throttle structure parameters can be provided for the optimal design of the throttle valve reference.The main research contents of this article are as follows:(1)According to the structural characteristics of the valve port of the U+T shaped throttling groove,the relationship between the valve port overflow area and the valve port opening degree is derived using the theoretical calculation method.Correspondence curve of opening degree,the characteristics of the change of valve port over-flow area with valve port opening degree are analyzed.(2)Using CFD technology,a three-dimensional simulation model of the throttle spool valve was established,the grid was divided,and the model was numerically simulated to obtain the internal oil of the throttle spool valve under different valve openings and different throttle groove structure parameters.The distributions of pressure field,velocity field and temperature field show that the pressure drop at the throttle is the largest,a high-speed jet is formed at the outletof the throttle,and the walls at the outlet of the throttle and the throttle form a local high temperature.(3)A three-dimensional steady-state heat analysis model of U+T groove slide valve spool is established.The flow field calculation results are introduced into the model.as a result,the maximum temperature of the spool is mainly concentrated at the throttling slot,which increases with the increase of valve opening,throttle groove depth,radius and bottom edge length,and decreases with the increase of U shape edge length.(4)A three-dimensional steady-state structure analysis model of U+T groove slide valve core is established,and the heat conduction calculation results of valve core are introduced into the model.The results show that the maximum radial deformation of the valve core is mainly affected by the opening of the valve mouth and the horizontal section of the throttle groove,and less by the depth of the throttle groove.(5)On the basis of simulation,the valve port flow coefficient and steady-state hydrodynamic force of the throttle spool valve under different valve port openings and different throttle structure parameters are explored,and combined with genetict algorithms to optimize the design of the throttle groove structure parameters.The thesis has 70 figures,5 tables,and 86 references.