整合於微型氣動轉子之軸向振動器設計開發與性能研究

Abstract

現代高速牙醫手機皆利用氣渦輪轉子的高速旋轉動來產生磨削動力，整合超音波振動之加工技術也已證實可以提升切削效能，所以本研究將軸向振動器整合於氣動轉子上，以提高牙醫手機切削性能。設計流程先進行致振原理探討、概念設計與模擬分析，開發氣壓式和壓電式兩種振動器，並設計了一個支撐結構將軸向振動整合於牙科手機頭上。除了振動器性能測試外，並分別測試驗證探討操作參數振動頻率、振幅、切削負載對於切削率影響。扭轉彈性之支撐結構可以提供刀具軸向彈性負載，使得氣動筒匣在受0.52~0.84 N軸向負載作用下，可以提升切削率穩定度3.7倍。開發出共振頻率為11.5 kHz之壓電振動器，其振幅可達1.05μm，切削率則可以提升1.8倍。運用氣槌效應開發氣壓振動器在氣壓為4.5 bar和承載力為24~37 N時，可產生頻率範圍202~245 Hz 振幅1.3~2 mm的軸向振動，並提升切削率1.2倍。

Present dental handpiece applies the high-speed rotation of the turbine to create cutting power. It is also verified that the integration of ultrasonic vibration into the machining technology can enhance the cutting efficiency. According to the above-mentioned background, the aim of this thesis is to develop a dental handpiece integrated with an axial vibrator to increase its cutting efficiency. The design process starts with study of vibration actuating principles, conceptual design and simulation. Two vibrators, the piezo-vibrator and the pneumatic vibrator, are developed, and a supporting structure is also designed to integrate the axial vibration with the head of the dental handpiece. Besides the individual performance testing of the vibrators, the influence of their operational parameters such as vibration frequency, amplitude and cutting load on the cutting efficiency are also separately tested and verified. The supporting structure developed possesses a torsional flexibility that can provide the cutting tool an axial elastic loading. For an axial load of 0.52~0.84 N, the cutting stability of the turbine cartridge can be enhanced by 3.7 times with the supporting structure. The developed piezo-vibrator has the resonant frequency of 11.5 kHz with the maximum amplitude of 1.05 μm, and it can increase the cutting rate by 1.8 times. By using the aero hammer principle, the developed pneumatic vibrator can create the axial vibration with the frequency of 202~245 Hz and the amplitude of 1.3~2 mm for the air supply of 4.5 bar and the axial load of 24~37 N, and it can increase the cutting rate by 1.2 times.