機械式自行車自動變速器之理念設計方法

Abstract

本研究之目的在於發展一種對於機械式自行車自動變速器可行之設計方法，經由本研究可系統的合成由機械式離合器條件式變速之自行車自動變速系統。首先以功能動力圖將現有之多動力流系統轉換成簡單的圖示表示，可表示其構造與功能及動力流數，接著系統化發展符合自動變速器特徵之雙動力流以及多動力流之功流系統。並透過離合器之配置組合功流系統並完成機械式自行車自動變速器之設計。接著透過數學方法分析其功流效能，並藉由Matlab對於系統效率進行數值分析，完成系統效能之推估，以參數解從中選出較有效率之系統。再以直線及上坡加速模型對於所選出之系統進行相互比較，從中選出較有效率之系統，並以改變變速時機以及變速減速比對之進行系統效率最佳化，並將最佳化模型對基本城市自行出模型進行相互比較以驗證此方法所發展之系統具可行性。

The propose of this study is to develop the possible design concepts for the mechanical bicycle auto-transmissions. Through this study, we are able to synthesize and evaluate the mechanical bicycle auto-transmissions by mechanical clutch. In this study, firstly, the ”functional power graph” is developed, which can transform the multi-power flow system to easy graph. Then we can develop the new double-path or triple-path system by a systematical design method. Through combining the power stream system by placing the clutches, we can create new system design of mechanical bicycle auto-transmissions. Then, we can analyze the effectiveness of the system by using the parametric analysis, and select the system which have better effectiveness. By using Matlab to analyze these system by straight accelerated method, we can realize the which is the best effective system. And we can optimize its effectiveness by changing gear-ratios and transmission timing. Finally, we can compare the system with the basic city bike model to verify the method, and show the advantage of the automatic transmissions systems.