Research On Mechanism And Device Of Ultrasonic Assisted Micropore Drilling

Ultrasonic vibration drilling technology is a new method of microporous processing,which combines the two movements of rotation and ultrasonic axial vibration.Resulting in the periodic changes in the cutting parameter such assuch as cutting speed,cutting depth,feed,etc.This method fundamentally changes the drilling mechanism and realizes the pulse intermittent cutting processing which has an incomparable machining effect compared with traditional drilling.Aiming at the defects existing in the traditional drilling machine in drilling micro holes,Based on the principle of vibration drilling,a set of ultrasonic axial vibration drilling device was designed in this paper.And the main components of the spindle system of the device such as ultrasonic generator,transducer,horn,tool system were designed.The device can be used for drilling micro-holes.The research shows that the application of ultrasonic vibration to micro-hole drilling can effectively solve the problems of traditional drilling.The main research contents include:(1)The basic theory of ultrasonic vibration drilling and the drilling mechanism were deeply studied,including the kinematic rules of vibration drilling,the dynamic angle characteristics of drill bit,the static and rigidification of drill bit and the cutting force mathematical model of ultrasonic vibration drilling And other aspects of an in-depth analysis.Kinematics characteristics and vibration drilling mechanism of ultrasonic vibration drilling were analyzed from kinematics.The effects of vibration drilling processing technology were analyzed from the aspects of chip removal by vibration drilling,surface roughness reduction and height reduction of exit burrs.(2)A set of ultrasonic axial vibratory drilling device was designed,which can be directly installed on the universal drilling spindle for micropore drilling and obtain high quality micropore.Finite element software ANSYS was used to simulate the dynamiccharacteristics of the core components of the ultrasonic vibration device,The natural frequencies and mode shapes of the horn and the amplitude of free ends at resonance amplitude were obtained,so that the horn with larger amplitude amplification coefficient was obtained.(3)Based on the principle of metal cutting,the mathematical model of ultrasonic vibration drilling was established.The finite element software Third Wave Systems Advant Edge FEM was used to simulate the ultrasonic axial vibration drilling proces,the drill and the workpiece stress curve and temperature curve was drawn by Tecplot software,the main analysis of this paper is the tool and the workpiece's change of cutting force and cutting temperature.The simulation results shows that after drilling a certain depth,the axial cutting force oscillates up and down at a certain value,this characteristic has fundamentally changed the traditional drilling mechanism for axial vibration drilling,making it a huge advantage compared with traditional drilling.The research results are of great significance to the study of the mechanism of axial vibration drilling.(4)Based on the theory of ultrasonic vibration drilling and the existing experimental conditions in our laboratory,the simulation experiments and common drilling experiments of ultrasonic vibration micro hole drilling were carried out by using vibration table and micro drilling machine,From the experimental point of view,the ultrasonic vibration drilling technology was studied.Through the analysis of the experimental results and data,the experimental results show that ultrasonic vibration drilling can significantly improve the machining quality,reduce cutting force and torque,improve chip breaking and chip evacuation capabilities.