Design And Experimental Research Of The Composite Longitudinal-Torsional Ultrasonic Milling System

In recent years,with the development and progress of science and technology,highhard and brittle materials have been widely used in many fields such as aerospace,medical treatment,and armament manufacturing.Ultrasonic vibration machining shows a high processing efficiency and good surface quality when processing a variety of hard and brittle materials.Two-dimensional composite vibration machining can greatly improve the machining quality comparing with the one-way vibration machining.In order to better play the advantages of ultrasonic vibration processing,this paper designed a twodimensional longitudinal-torsional ultrasonic milling processing system and conducted experimental exploration.In this paper,numerical simulation method and finite element simulation of ANSYS are used to design the conical transition composite horn,and helical slots are set in the conical section.The existence of the transverse wave at the helical slots is analyzed,and the mode conversion mechanism of the helical slots is derived theoretically.The result of modal analysis verifies the output of the longitudinal-torsional composite vibration at the end of the horn;through the transient dynamic analysis of the horn,the vibration trajectory of the composite vibration which is an approximate elliptical structure is fitted.Secondly,on the basis of finite element modal analysis of ANSYS,The geometric parameters of the helical slots on the longitudinal-torsional horn are explored,including the number of helical slots,the rotation angle,the depth of the helical slots,etc,which affect the resonant frequency of the horn,the magnification and the ratio of the torsional and longitudinal components.The orthogonal order parameter analysis method is used to analyze the primary and secondary sequences affecting the ratio of the helical slots to the horn ratio of the horn and the resonant frequency.According to the stiffness requirements of the horn and the requirements of the system processing applications,the geometric parameters of the helical slots are selected.Combining ANSYS finite element simulation and impedance analysis tests,the influence and the sensitivity of the three-section structure length of the helical slots longitudinal-torsional horn on the horn ratio,amplification factor and resonant frequency of the horn is discussed.The frequency correction equation was established to solve the frequency offset problem of the horn after opening the helical slots and adding the tool post.The equation was used to modify the frequency of the horn and the deviation is only 0.47% of the design value after correction.The system has a high degree of matching.Finally,using a self-developed ultrasonic power supply,a longitudinal-torsional ultrasonic vibration milling system test stand is set up.The ultrasonic atomization system is tested for vibration atomization.The influence of the extension of the tool bar on the ultrasonic system is analyzed,and the impedance analysis result is verified.The correctness;development and design of ultrasonic torsional vibration evaluation device and method: By arranging multiple measurement points on the side of the milling cutter,using a laser displacement sensor to measure the torsional amplitude of each point,fitting out the torsional amplitude function curve,and thus accurately calculate the tool The torsional amplitude at a certain point on the rod quantifies the compound vibration output from the system and validates the results of the finite element simulation.