Device Design And Experimental Study On Ultrasonic Removal Of Burrs At Small And Cross Holes

The burr is the most common incidental product in machining,and it is extremely harmful to the performance of some precision components.There are a large number of cross-hole features in the valve parts of aerospace and precision medical instruments.Such valve parts with cross-hole features are difficult to remove the burrs at the intersection of the intersecting holes during machining,which will greatly reduce the reliability of the equipment and instrument during operation.With the continuous research of ultrasonic processing technology by experts and scholars,ultrasonic processing technology has been widely used in engineering.Aiming at the problem that the burr is difficult to remove at the intersecting line of intersecting holes,this paper proposes to remove the burrs of the cross holes by ultrasonic machining,and makes a specific study on the processing method.The main researches work of the thesis are as follows:(1)A test device for ultrasonic removal of cross-hole burrs is designed and fabricated.Based on the characteristics of ultrasonic machining and fluid abrasive processing,the overall program of the ultrasonic removal cross-hole burr device is carried out.After the selection and design of each functional module in the device,the ultrasonic removal of the cross-hole burr is successfully produced.(2)The core component horn in the ultrasonic machining system is designed and analyzed.Firstly,a single longitudinal vibration cone-shaped composite horn is designed by combining theoretical design and finite element analysis,and impedance analysis and field test are carried out.Test analysis shows that the designed horn has good vibration performance and meets the design and use requirements.Then,the longitudinal torsional resonance horn is designed through the method of cutting spiral groove in the conical transition section of the conical composite horn.Finally,the influence of the structural parameters of the longitudinal torsional resonance horn on its resonant frequency and torsional longitudinal ratio is analyzed.(3)The finite element analysis software is used to analyze the burr removal process at the cross hole.On the one hand,FLUENT software is used to analyze the flow field distribution in the cross-hole during ultrasonic machining,and the distribution of flow velocity,erosion rate and turbulent kinetic energy in the crosshole is analyzed.On the other hand,the explicit dynamics module of ANSYS software is used to analyze the dynamic response of the work-piece wall when the micro-jet liquid column impacts the wall surface of the work-piece.The influence of the impact velocity and the distance of the two micro-jet liquid column on the stress and strain of the work-piece wall surface when the single micro-jet liquid column and the two micro-jet liquid column impact the work-piece wall surface are analyzed.Through the numerical simulation analysis of the burr removal process at the cross holes,the mechanism of ultrasonic removal of the burrs in the cross holes is described more specifically.(4)An experimental study on ultrasonic removal of cross hole burrs is carried out by using the designed test device.The orthogonal experiment is designed to study the effects of three crafts parameters,such as abrasive particle size,suspension concentration and rotation speed,on the removal effect of crosshole burrs,and the best combination of craft parameters is obtained.The experimental results show that the ultrasonic deburring process can effectively remove the burrs at the intersecting lines of the cross holes and can effectively reduce the roughness near the intersecting line of the 45 steel cross holes from Ra11.2?m to Ra2.68?m.