Theoretical And Experimental Study On Vibration Characteristics Of Longitudinal Vibration Direction Transducers With Single Or Multi-terminal Output

The development of green technologies for industrial processing is one of the main scientific and technological challenges at present.Power ultrasonic is a green emerging technology that offers a great potential for a wide range of processes.Ultrasonic energy traveling in medium could produce the effect such as machinery,cavitation,and thermology.The important features of power ultrasonic are its capacity to accomplish the work that other technologies could not complete as well as to act synergistically with other forms of energy in order to promote,accelerate or improve existing processes.Ultrasonic longitudinal vibration system,which is basically composed of transducer,solid horn and tool,is the key part of the ultrasonic technology,and the most common ultrasonic longitudinal vibration systems are designed to allow the vibration travels along straight direction.However,some applications need to change the transmission direction of longitudinal vibration,such as cleaning of internal surface of the pipe with bent section,ultrasonic scalpel and ultrasonic dental descaler.The transducer of ultrasonic vibration system could only connect one horn(or and one tool head).It means a set of ultrasonic vibration system could only machine or process one object.When some applications need the ultrasonic energy with high power capacity and efficiency,extensive radiating area to cover large volumes,more traditional ultrasonic longitudinal vibration systems are required,such as condensation of ultrasonic,ultrasonic defoaming,ultrasonic cleaning and ultrasonic wastewater treatment.To solve the problems,the angled ultrasonic solid horns which could change the transmission direction of longitudinal vibration and the converter of longitudinal vibration with multi-outputs which could process multiple objects are researched with theoretical and experimental methods.The main content includes the following sections:(1)The design method for angled longitudinal vibration ultrasonic solid horn is investigated.Solid horn is composed of input rod and output rod.The frequency equation is established by using the mechanical coupling conditions at the joint,as well as free boundary conditions at its two ends base on the one-dimensional vibration theory.Vibration mode shapes of the horns are tested.The result shows that longitudinal vibration can be transferred from the input end to the output end through the solid horn.The resonant frequency,displacement amplification factor,longitudinal vibration displacement distribution,stress distribution and output characteristics are obtained by theoretical or experimental methods.The effect of horn’s geometrical dimensions to every performance parameter is quite different.Resonance frequency is mainly influenced by length.Displacement amplification factor is mainly influenced by the ratio of length and radius of the input and output rod.All of horn’s dimension could influence displacement distribution.The maximum stress still locates at the inner side of the bending parts.(2)A directional converter of longitudinal vibration with multi-outputs is proposed,which is composed of an input rod,a converter of longitudinal vibration,and several output rods.Every component locates in a plane.The frequency equation is derived by using free boundary conditions at the input end of the single-input rod and the output ends of the multi-output rods,as well as the continuity of displacements,forces,bending moments and angles of rotation at the junction of the input rod and the converter,and at the junction of the converter and the multi-output rods.The experiment tested results show that longitudinal vibration mode shape at the end surface of each output rod can be obtained.Connecting a transducer to the proposed converters,longitudinal vibration can change single-input into multi-outputs and multiple objects can be machined or processed.Vibration displacement amplitude of the middle output rod is higher than two other output rods and the remove of middle output rod has no influence on the two other output.(3)A directional converter of longitudinal vibration of uniform amplitude with multi-outputs,composed of an input rod,a hemispheric converter and three output rods,is presented.The frequency equation is obtained and the resonant frequencies of the three fabricated converters designed by the proposed method are almost in good agreement with experimental tested values.The experimental test of vibration mode result shows that longitudinal vibration can be transferred from the input end to the multi-output ends through the converter and the amplitudes of the each output end are almost equivalent.The angled ultrasonic longitudinal vibration solid horn and directional converter of longitudinal vibration with multi-outputs investigated in this paper could be applied in the actual ultrasonic processing in order to improve the work efficiency and reduce economical cost.