超音波振動系統在高溫下之最佳化設計

Abstract

超音波振動輔助加工可提高工件材料的性質，使材料成形性提高，降低成形時所需之負荷。若將超音波系統作用於高溫下，結合熱壓、熔接、切削研磨等製程，更可製造出高精度與高品質兼具的產品。目前業界對於超音波振動系統的設計製作方法，均憑藉理論近似解與經驗公式進行初步的設計製作，再利用模擬分析試誤法，以反覆模擬結果修改模型，以求得最佳設計參數，因此效率不高。 本研究利用有限元素軟體ANSYS對超音波振動系統進行高溫下的分析，再將模擬結果與實驗結果相互驗證，以確認本研究所提出之超音波振動系統在高溫下之有限元素分析模型。最後結合有限元素分析與最佳化設計，針對輸出端面振幅分佈不均勻的問題進行改善，並在高溫工作溫度下針對超音波振動系統放大器外型最佳化，以建立可應用在熱壓機台上之自動化超音波振動系統之最佳化設計流程。

The ultrasonic vibration assisted manufacture can improve the material properties and reduce the forming pressure. When some manufacture processes such as embossing, welding, cutting or grinding process were combined with ultrasonic vibration system at high working temperature, products with both high precision and high quality can be obtained. Presently in the industry, the design process of the ultrasonic vibration system is based on approximate theoretical solutions and empirical formulas to obtain rough design, and then finite element analysis was conducted to refine the design. This numerical design was then modified through iterative trial-and-error experiments. The whole process is time consuming in getting final optimum parameters. In this study, an ultrasonic vibration system with high working temperature was analyzed by finite element software ANSYS. The simulation results were compared to experimental measurement, to confirm the validity of the numerical analysis. The verified finite element model can be used in the components design of the ultrasonic vibration system with elevated temperature. Finally, this research combines the finite element analysis and the optimum design to provide the uniformity of the output amplitude of the system. Then, the optimal geometry of horn for ultrasonic vibration system with high working temperature was derived and experimentally verified. The optimum design automatic ultrasonic vibration system in this research can apply to the design of hot embossing apparatus.