Theoretical And Experimental Analysis On The Dynamic Characteristics Of Textured Pilot Valve During Starting

The pilot valve is a kind of oil pressure or electromagnetic signal to change the displacement of the slide valve,so as to control the oil pressure of other oil passages.It is the core component of the oil machine.The engine oil machine have the problems of complicated working condition,easy hydraulic clamping,increased leakage,large time delay of control signal transmission,etc.In this paper,by using the bionic texture as the starting point,the inclined drop vibration test stand is set up,and the computational fluid mechanics theory and the immersion law are used to simulate the steady state and the transient numerical simulation of the internal flow field in the pilot valve.At the same time,the changes of oil film pressure and leakage are observed in order to improve the working performance of the pilot valve and improve the vibration of the valve core,sticking and even breaking in the process of operation.The main research contents are as follows:(1)Using the optical fiber laser processing metal as the micro-texture substrate,the change of the running shape of the liquid drops in different vibration periods is studied,and the movement mechanism of the vibrating liquid droplets on the surface of the texture is revealed.At the same time,based on the experimental results of droplet dynamic wettability,a theoretical model of forced vibration inclined droplet motion evolution is established to simulate the movement spreading process of droplets on the substrate with different interface characteristics.(2)The texture design of the surface of the valve core is carried out,and the appropriate model is selected for the important equipment and the sensor required for the experiment,and the design scheme of the pilot valve performance test stand is determined.The experimental data such as amplitude flow,pressure and displacement of the texture pilot valve and common throttle were collected.(3)The three-dimensional models of fluid domain and solid domain are established,and the changes of internal velocity field and turbulent kinetic energy cloud diagram are observed through simulation calculation during the opening process of the pilot valve.By changing the inlet pressure,the force on the end face of the common valve core seal and the textured valve core seal end face and the flow rate at the outlet of the pilot valve are obtained.The oil film model is established to analyze the changes of different rotational speed,different inlet pressure,oil film pressure cloud picture,oil film pressure and leakage.