改良式壓電音洩傳感器之製作與測試

黃子瑋(Zi Wei Huang)

指導教授 ： 馮國華

國立中正大學/工學院/機械工程學系/碩士(2013年)

摘要

本篇論文主要是由具曲率的壓電薄膜、市售PZT、應變規三層結構所組成的音洩傳感器，其中壓電薄膜是選用高分子壓電薄膜(聚偏二氟乙烯)，其具有高柔韌性及耐衝擊性，並使用黃光微影技術製作模仁並進行壓印，使其平面結構轉變為曲折結構，另外再加入市售的PZT及應變規的結構，可增加其應用性。
在傳感器應用部分，我們模擬了工件在工具機台上加工遇到工件內部螺紋加工無法看見的問題，透過應變規及傳感器的訊號，可以清楚了傳感器與工件是否有確實接觸，也可以了解刀具何時碰到工件，何時要做停刀的動作，以方便操作人員的使用，而在物質材料辨識的應用中，透過傳感器發出及接收到的訊號比較後，我們可以從數據中判斷不同材料的軟硬程度。
最後我們也跟市售的音洩感測器做比較，可以發現自製的傳感器具有較佳的訊雜比，且價格便宜，另外可以透過應變規的訊號得知自製傳感器與物件接觸的鬆緊程度，而確保訊號的正確性。

關鍵字

音洩感測器 ； 應變規

並列摘要

This study of acoustic emission sensors is based on a three-layered structure comprised of curved piezoelectric membranes, merchant PZT patches and strain gauges. In the study, piezoelectric polymer membranes (PVDF) were selected to serve as curved piezoelectric membranes due to their high flexibility and impact resistance. Also, photo lithography was introduced in the process of manufacturing molds and embossing, which transformed the structure from flat surface to curvature. In addition, the composition of merchant PZT patches and strain gauges increased the applicability as well.
In view of sensor application, the simulation was performed to identify issues that internal thread processing was undetectable when workpieces were machining on the worktable. Signals sent through strain gauges and sensors clearly indicated whether or not sensors had a direct contact with workpieces. Meanwhile, for the convenience of operators, the cutting tool would stop cutting when it touched the workpiece. Signals transmitted and received from the sensor were analyzed to identify the degree of stiffness in various different materials.
Finally, it was found that home-made acoustic emission sensors had better signal to noise ratio and were cheaper in comparison to merchant sensors. Moreover, home-made sensors detected signals from strain gauges to recognize the degree of tightness in contact with workpieces, thus to ensure the accuracy of the signal.

並列關鍵字

strain gage ； AE sensor

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