Research On Hole Shape And Flow Field Simulation Of Micro-hole EDM In Palace Throttle Valve

With the rapid development of aviation,aerospace,and medical engineering,product miniaturization has become the goal of development in various fields,to realize the miniaturization of products,the processing of micro 3D devices must be given attention.Micro holes are widely used in the field of microelectromechanical systems and the fabrication of micro 3D structures due to their unique functional structure.EDM has a powerful micro-scale fabrication capability and incomparable advantages for tiny size machining because it is not affected by the complexity of the workpiece and the properties of the workpiece material.However,because of its small aperture,machining chip is not easy to eliminate and induced secondary discharge and other factors in the process of EDM of micro-hole,and the loss taper will be formed at the edge of the hole mouth,which has an important influence on the precision of hole forming law.Labyrinth type throttle valve uses micro-hole structure as the main control means of throttling and depressing.Therefore,the micro-orifice shape parameters have an important influence on the flow field performance of the microchannel of the labyrinth throttle valve.In this paper,the forming law and the flow field performance of micro hole are studied from the Angle of the forming law of micro hole and the influence of hole shape on the flow field performance of micro channel of labyrinth throttle valve.Firstly,according to the principle of back-print machining,the micro-electrode needed for the micro-hole experiment of EDM is manufactured,and the influence of different discharge machining parameters on the size and accuracy of hole-making is studied.The influence of the parameters on the forming of micro-hole under different workpiece thicknesses was analyzed.Secondly,the micro-channel simulation models of labyrinth type throttle valve with different micro-orifice shape were established,and the fluid flow field simulation of labyrinth type throttle valve microchannel was carried out,and the influence of micro-orifice shape on fluid pressure drop and velocity distribution of labyrinth type throttle valve was analyzed.The flow field simulation and comparison of labyrinthtype throttle valve microchannel with different depth to diameter ratio horn hole shape were carried out,and the influence of different depth to diameter ratio horn hole on pressure drop and velocity of labyrinth-type microchannel flow field was explored.