Study On Structure And Vibrational Characteristics Of Longitudinal-torsional Composite Ultrasonic Machining Device

Compared with traditional ultrasonic machining, the longitudinal-torsional ultrasonic machining has many advantages, there are a variety of ways to achieve two-dimensional longitudinal-torsional vibration. This paper mainly researches the structure and the vibration characteristics of longitudinal-torsional composite horn under a single excitation source.Firstly, the formation mechanism of two-dimensional longitudinal-torsional vibration of vibration rod with oblique groove was described based on the principle of wave reflection and refraction. And then structural parameters of vibration rod with a rectangular chute were designed under no load condition using the resonance frequency equation. Furthermore, the dynamic characteristics and vibration rod impedance was analyzed using 3D modeling imported into the ANSYS software. The results show that acoustic vibration features of vibration rod is good, and consistent with the results of simulation analysis. And the vibration rod is provided forward or reverse double chute, forward double chute structure enhances the torsional vibration of the role more obvious. On the basis of composite horn theoretical formula, This paper studies the working frequency of 20 kHz, 28 KHz, 35 kHz transition section geometries were composite horn index type, conical, hanging chain type, and dynamics analysis. The results show: the frequency of composite horn is close to work frequency, resonance enhancement, the longitudinal vibration is well, and the amplification coefficient is consistent with the theoretical value. The composite horn small end structure is changed the ring groove structure, carrying out modal analysis, by using salient points as the allocation block, composite horn of different structure are better achieved the longitudinal-torsional vibration. Selecting 28 kHz transition section is a composite horn of exponential type, discussing the effect of ring slot structure parameters of horn of the longitudinaltorsional vibration of the resonant frequency, and the structure parameters are optimized.Finally, an experimental platform was built on the basis of theoretical resear-ch.The impedance analysis and amplitude were tested using the impedance analy-zer and laser displacement sensor to identify the stability and composite vibratio-n characteristics of longitudinal-torsional of the composite horn acoustic system. The results show that the vibration characteristics of composite horn acoustic sys-tem are acceptable.