本研究是提出一新型磁流變液式可變氣門正時與升程機構之設計與動態分析,以實體機車引擎之機件構造加以修改組合作初步設計,並參考Fiat MultiAir系統模式為最終目標。使用Solidworks電腦輔助設計軟體進行機構模型設計,再利用Adams機構分析軟體作動態模擬分析。此機構模型是將傳統氣門機構之單搖臂改良成一組有調整搖臂及調整軸之搖臂組;將凸輪搖臂固定軸改良為外徑上有凸件的調整軸,而凸輪搖臂中挖槽並放置調整軸,且在兩者間加入磁流變液,並在凸輪搖臂外圍纏繞線圈,當線圈通電時,磁流變液將變為固態。藉由線圈通電與否改變磁流變液狀態進而調整搖臂角度變化,達到不同高低的氣門升程變化及可變氣門正時的功能。本研究針對所設計之可變氣門機構做相關氣門升程圖並論述其優缺點並完成初步設計。本機構能完成多重氣門升程及可變氣門正時的功能。 關鍵詞:可變氣門正時、可變升程、磁流變液、機構設計
This paper is to propose a new type of MRF-type variable valve timing and lift mechanism design and dynamic analysis, while the components of real car-engine for composition and modification as preliminary design, and with reference to Fiat MultiAir system mode for the ultimate goal . Using computer-aided design software Solidworks to create models, and then using the simulation software Adams is used to do dynamic simulation analysis. This model is intended to modify the conventional single rocker arm into a set of adjustment rocker arm and adjustment shaft; the fixed shaft of the cam rocker is improved as adjustment shaft with adjustable object at outer diameter, the cam rocker in trenching and set adjustment shaft, the magnetorheological(MR) fluid is added between them, and the periphery of the cam rocker arm wound coil, when the electromagnetic coil is energized, the magnetorheological fluid to solid. With the coil is energized or not to change the status of MRF and then adjust the change of rocker arm angle, to achieve the functions of different valve lift and variable valve timing. In this study, the variable valve mechanism designed to do the relevant valve lift diagram and discuss their advantages and disadvantages and completed the preliminary design. The agency can perform functions of multi lift and variable valve timing. Keywords: variable valve timing, variable lift, magnetorheological fluid, mechanism design