平板揚聲器的軟性振動板開發

Developing Flexible Vibrating Plates for Flat-panel Speakers

本文主要以框架設計、振膜開發、激振器製作、來開發一全音域B5平板揚聲器。傳統揚聲器的振膜材質多採用紙的材質，容易因環境溫度以及濕度變化使振膜產生變形，利用PU發泡技術來開發新振膜素材，其PU發泡振膜具有良好的耐氣侯變化性、機械性質，在增加最小的質量之下大幅提高剛性，使得平面揚聲器的聲壓曲線更加平滑，藉此生產出優於紙類振膜的PU發泡振膜。探討PU發泡振膜作為平板揚聲器振膜之可行性，以不同厚度、密度為製程參數，改善發泡條件提高製作良率，並藉由拉伸試驗取得不同製程參數的PU發泡振膜之機械性質，將PU發泡振膜實際組裝到平板揚聲器及量測聲壓曲線，對聲壓曲線進行探討，並針對聲壓曲線量測結果改善製程參數，獲得最佳製程參數及平滑聲壓曲線。在有限元素分析方面，利用有限元素ANSYS模擬分析及實體組裝的B5平板揚聲器進行理論分析與實驗量測的聲壓曲線比對，證實ANSYS分析模型的正確性，最後利用田口品質工程方法來取得最佳聲壓變異數之參數組合。

In this study, a full-range B5 flat-panel speaker was developed and a framework was designed, developing diaphragms, and producing exciters. Traditionally, speaker diaphragms are manufacturing using paper, which easily deforms because of ambient temperature and humidity changes; PU foam technology was used to develop a new diaphragm material. PU foams diaphragms exhibit excellent weather resistance and mechanical properties, at increase minimum weight under significantly raise rigid, make flat-panel speaker of the sound pressure curve getting smoother that the PU foams diaphragm is superior compared with the paper diaphragm.To explore the feasibility of using PU foam diaphragms as flat-panel speaker diaphragms, varying thicknesses and densities were used as the processing parameters to improve the foaming conditions and production yields. The mechanical properties of the PU foam diaphragms were analyzed by conducting tensile tests to determine various processing parameters. PU foam diaphragms were used to assemble flat-panel speakers and the resulting sound-pressure-volume curves were measured. Exploring the sound pressure curves facilitated determining the optimal processing parameters and generating smooth sound-pressure curves. In the limited element analysis, ANSYS simulation was used to conduct a finite element analysis and entity assembly B5 panel speaker sound pressure curves were compared for a theoretical analysis; subsequently, the validity of the ANSYS analysis model was confirmed. Finally, the Taguchi method was used to attain the optimal parameter combinations of sound pressure variation.