- 學位論文
應用田口法於四行程引擎進排氣凸輪設計研究
Applying Taguchi Method on Inlet and Exhaust Cams Design for a Four-stroke Engine
摘要
本文主要研究目的為改善高轉速四行程引擎的進氣效率的改善，高轉速引擎因為轉速較高，進氣門開啟時間較短，在高轉速狀態下進氣效率會變差，因此影響進氣效率的進排氣凸輪成為重要的引擎性能參數。利用進排氣凸輪改變進氣閥開啟截面積的大小，讓引擎在高轉速運轉下進氣流量變大，改變進氣效率可以使四行程引擎的燃燒效率提高並減少燃燒不完全的廢氣排放量，使引擎達到高效率和低汙染，符合環保要求。本文的實驗方法，首先量測2009 出廠KYMCO之RACING150 機車的引擎馬力，經特性要因圖分析後，選擇進排氣凸輪為控制因子。接著，利用田口法L9 直交表進行實驗，每組實驗取50 組數據的平均，減少人為操作誤差及引擎熱機前後的差異最後，利用田口品質工程與實驗設計的方式，再以變異數分析探討不同進排氣凸輪變化對於引擎馬力的影響。 本文實驗所獲得進氣凸輪揚程高度為5.7mm、排氣凸輪揚程高度為5.4mm、進氣凸輪寬度不變、排氣凸輪寬度加大0.25mm 為最佳，所得的引擎馬力再高轉速下都優於原廠設定，由此可見改變進排氣凸輪對於引擎馬力提升是有幫助的，尤其是在高轉速時，改變進氣凸輪揚程對引擎馬力提升影響甚大。
並列摘要
The purpose of this study is to improve the intake efficiency of the high-speed four-stroke engine. High-speed engines have short time to open the intake valve. So the intake efficiency will deteriorate. Therefore, the Intake efficiency is the important factor affects the engine efficiency. The engine horsepower experiment is based on the KYMCO RACING150 available in the market. We choose the intake and exhaust cam lift for the control factor by analyzing the characteristics with engine’s Cause and Effect Diagram. We choose three classes and using the Taguchi's Orthogonal Arrays-L9 for experiment. We choose the average of fifty data for each experiment data. Thus we can reduce the man-made errors in the operation and the difference before and after the heat of the internal combustion engine. To discuss the influence of the cam lift on the horsepower of the engine with the Taguchi method and the Analysis of Variation. By using the cam lift to control the cross section of the valve, we can have large inlet flow when the engine is in high-speed operation. We can improve the combustion efficiency of the four-stroke engine by changing the inlet flow efficiency,and decrease the incomplete combustion of emissions. Thus, the engine with high efficiency and low pollution will achieve the request of environmental protection. Experimental results show there is the maximum horsepower of the engine when the intake cam lift is 6mm, and the exhaust cam lift is 5.1mm. Whatever the motor’s speed changing, the resulting horsepower of the engine is better than the original set. So it can be seen to change the intake and exhaust cam lift is important to improve the engine horsepower, especially in the high-speed.