| Ultrasonic gear-honing processing technology is a new kind of processing technology by extending the ultrasonic vibration in gear honing. The technology combines ultrasonic waves with ordinary gear honing machine in gear compound machining, ultrasonic generator sends out high frequency oscillation signals which is converted into mechanical vibration by the transducer. and then through the horn with amplitude amplification, the ultimate role effects to the honing wheel, thus overcoming the shortcomings that is easy to be blocked of honing wheel, also improving the efficiency of processing. In recent years, the research gets the support from the National Natural Science Fund (fund No.50975191),which has made many remarkable achievements, but there are also some limitations, further research is needed to solve.In the process of gear honing, the conical type, the index type, the suspension chain type and the stepped type are useful. In these four style horn, conical and stepped are easy made, at the same time the stepped ultrasonic horn has the best amplification effect and the most conducive to honing the ultrasonic vibration, therefore which is widely applied. However as a result of stepped ultrasonic horn has the mutation occurs in the transition section, which causes the stress concentration, so there are many disadvantages to the stepped ultrasonic horn:first, due to the size of terminal area is large, the transition exsits excessive stress which reduces the service life of the stepped ultrasonic horn; secondly, we often ignored the effect of stress concentration when we are designing the stepped ultrasonic horn, thereby which causes the horn actual operating frequency less than the theoretical natural frequency, node forwards, greatly weakened the ultrasonic vibration machining effect; finally, under the same conditions, stepped amplification ratio is the largest, however, the maximum stress is far greater than the other horn, thereby causing the shape factor least.As can be seen from the above,it is very important to add transition arc in the mutation section,which decreases stress concentration and makes the work frequency restore with the theoretical frequency. The purpose of this paper is by the ANSYS finite element analysis software through the theoretical frequency20kHz,different big radius of three different groups of stepped ultrasonic horn in a series of amplification ratio adding different transition arc, finds out the amplification ratio under the optimal transition arc, and it can generalize to arbitrary stepped ultrasonic horn optimal selection for transition arc, which can as reference for the stepped ultrasonic horn production design. The main content of the paper as follows:(1) Elaborating the ultrasonic machining technology, ultrasonic honing processing technology research status at home and abroad, the research status of stepped ultrasonic horn.(2) According to the uniform fine bar longitudinal vibration theory equation is derived for horn displacement, stress equation, through these equations we can obtain the further horn frequency equation, by solving MATLAB horn optimal size length.(3)Through the establishment of PRO/E horn model, and then the ANSYS modal and harmonic response analysis, it can obtain the stress concentration on the influence of kinetic parameters.(4) According to the3group of stepped ultrasonic horn in different magnification ratio add different transition arc, we can find out its corresponding best transition arc, and then use the MATLAB binding method of least squares fitting, thus it can infer the horn best arc transition curve, and verify.(5) Used45steel processing with a transition arc horn and horn, with the percussion method for the determination of their respective natural frequencies, then compared, further analysis of the finite element method the optimal transition arc very correct.(6) Finally,1have done research work summary and prospect for the follow-up, the need for further research and perfect place specified direction. |
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