在駐車狀態下機車的振動來源，主要可分引擎搖撼力與引擎搖撼力矩兩種。由之前的研究得知，若將引擎假設在定扭力狀態下進行分析，雖然會比以往假設在定轉速狀態下耗費較多的運算與處理時間，但能獲得更貼近真實的運轉情形，所求得的引擎搖撼力與搖撼力矩也更為準確。
　　本文以兩部引擎配重與吊架型式不同之機車為研究對象，將引擎假設於定扭力狀態下，探討其搖撼力與搖撼力矩對於振動之影響，再對分析結果做離散傅立葉轉換，以供整車振動研究進行更準確的分析。由傅立葉分析結果可知，G5的U、V方向力之最大分量皆為30Hz，其大小也接近；超5的V方向力之最大分量為30Hz，且遠大於U方向力在60Hz及30Hz的分量。
　　進行振動影像實驗，在汽缸頭與車架中間各取一觀測點，以高速攝影機分別拍攝兩機車於怠速狀態下，引擎作為振源輸入時，各觀測點的實際振動軌跡與振動頻率。由實驗結果來看兩車的振動頻率皆在15Hz附近，佐證了引擎的運轉假設應該為定扭力狀態呈現之15Hz，而不是定轉速狀態的30Hz。而實驗結果與整車模擬數據經比對後發現，兩車在各觀測點之結果大抵相似，惟超5汽缸頭部分有顯著差異，分別於水平與垂直位移相差三倍與六倍。

　　The vibration sources of motorcycle in the state of parking can be broadly divided into two types, the shaking force and the shaking moment. From previous studies, if the engine was set in a constant torque condition, the analysis will be closer to the actual situation than the one set in a constant angular velocity condition. Also, the results were more accurate. However, it took more time and processing operations.
　　In this paper, two motorcycles which have different kinds of engine configuration and engine hanger were used to analyze the shaking force from vibrations by Discrete Fourier Transform, because Discrete Fourier Transform provided more accurate models vibration analysis. While let the engine runs at certain frequency, the results showed that the maximum force on U-direction and V-direction of G5 both were at the frequency of 30Hz with similar magnitude. The maximum force on V-direction of MEGA 5 was at the frequency of 30Hz, and was much larger than the maximum forces on U-direction which were at the frequency of 30Hz and 60 Hz.
　　A vibration test by image processing was done. The cylinder head and the middle of frame of two motorcycles were taken as the observation points, using high-speed camera to record them running at idle speed. With the shaking force and moment of engine as the input of vibration, the actual vibrational trajectories of each observation point, and the vibrational frequencies of each system were obtained. From the experimental results, the two motorcycles vibrational frequencies are nearby 15Hz, it showed that the assumption of the condition of engine should set in constant torque condition of 15Hz, rather than constant angular velocity condition of 30Hz. The vibrations of each observation points on the motorcycles obtained from the experimental method and the models simulation method were quite similar except for the vibration at the cylinder head part of MEGA 5, the horizontal and vertical displacement were difference by triple and sextuple respectively.

[1] Zweiri, Y. H., Whidborne, J. F. & Seneviratne, L. D., “A Mathematical Transient Model for the Dynamics of a Single-cylinder Diesel Engine,” International Conference on SIMULATION, Conference Publication No.457, 1998.
[2] Bali, F. N., Mahzan, S., Ghazali, M. & Wahab, A., “Effect of Body Tilt Angle to the Shaking Forces on the Diesel Engine’s Crankshaft,” Malaysian Technical Universities Conference on Engineering and Technology, 2009.
[3] 施翔耀，速克達型機車之引擎吊架系統，國立中山大學機械工程學系碩士論文，1997。
[4] 趙士偉，機車結構減振之設計方法，國立台灣大學機械工程學系碩士論文，2000。
[5] 李昆明，機車懸吊機構之系統化設計方法，國立台灣大學機械工程學系碩士論文，2002。
[6] Wu, C. C., Hwang, Y. W. & Lin, S. H., “Dynamic Analysis and Simulation of Virtual Engine,” Applied Mechanics and Materials Vols.121-126, pp.3770-3778 , 2012.
[7] Huang, Z. H. & Sun, Z. D., “Simulation Research on Synthesis Anti-vibration of Motorcycle Engine,” 2011 International Conference on Electric Information and Control Engineering, pp.5318~5320, 2011.
[8] 林毓恆，單缸機車引擎搖撼力探討，國立成功大學機械工程學系碩士論文，2011。
[9] 游勝祥，單缸機車引擎定扭力狀態下搖撼力探討，國立成功大學機械工程學系碩士論文，2012。
 
[10] 朱培銘，機車結構有限元素法模態分析及簡諧分析，國立成功大學機械工程學系碩士論文，2011。
[11] 黃奕翔，以有限元素法分析摩托車吊架型式對振動之影響，國立成功大學機械工程學系碩士論文，2012。
[12] 張培毓，以有限元素法模擬不同引擎吊架型式機車之振動，國立成功大學機械工程學系碩士論文，2013。