本文描述一高輸出水冷式二行程速克達機車於開發階段之噪音減量研究及改善過程,藉由原型車上之諸噪音及振動實驗分析,分別採取相關及複合的改善策略,重新調協(Tuning)排氣系統與引擎性能特性、改良排氣消音系統結構與傳輸損失特性及調協CVT傳動變速特性範圍的情形下,結果顯示原型車在不降低最高極速性能及0至100公尺加速性能超出5%範圍的要求下,其行進間加速噪音級(CNS 3110)可由改善前的79.3 dB (A)降低至改善後的目標70 dB (A),共降低達9 dB (A),而以噪音能量計算則共降低87%的聲能。
The diagnostic and improvement of noise emission of a prototype scooter motorcycle with two stroke water-cooled high specific output engine was conducted in this work. The beneficial treatments which were related and combined to its noise reduction was deduced from the experimental analysis of various NVH tests. These treatments also included further tuning of the exhaust system, engine performance characteristics, muffler construction and transmission lose, and transmission characteristics of the CVT drive train system. The results show that the motorcycle could achieved an expected goal. The noise level is reduced from an original state 79.3 dB (A) to final state 70 dB (A) under the pass-by noise test (CNS 3110). However the lose of the top speed and the period of acceleration between the distance from 0 to 100 meters would not exceed 5%. The total decrease in sound pressure level is 9 dB (A), while in energy is 87% off.