- 學位論文
連續無段變速系統(CVT)之油壓控制最佳化
Optimization Research for Oil Pressure Control of CVT
摘要
主動式無段變速系統可較傳統有段式變速系統提供較平順的換檔動作及較密的齒數比，藉此更貼近操控者的需求，如：舒適的乘坐經驗、較高的傳輸效率、較優的加速性。擁有上述優點且能成為近年來汽車傳動系統主要發展的其中一支，其潛力值得深入再探討研究。無段變速系統是藉由一次皮帶盤油壓及二次皮帶盤油壓的調整以改變皮帶盤的開度，進而控制減速比。其中油壓的建立是受制於變速箱輸入軸的轉速，當所需油壓不如提供的油壓高時即造成無謂的浪費，本研究即希望能夠在不影響變速箱性能的前提下找出最低的所需油壓值，以符合現今節能的潮流。 本研究設置人機介面實驗平台，將無段變速系統的扭矩轉換器改裝成內外軸獨立旋轉之機構，使無段變速系統之油壓值不受主動力源轉速之影響，而以另一油壓馬達控制無段變速系統之油壓值，達成將主動力源轉速與油壓泵浦轉速兩者獨立控制之目的。實驗平台使用LabVIEW作為監控程式並利用美商NI的資料擷取系統，藉收集各項參數運算後以控制CVT油壓系統，並觀測輸入軸與輸出軸的轉速變化驗證是否符合減速比之需求。電腦模擬油壓控制分析部份則以資料擷取系統取得之減速比與目標減速比做比對，再將資料傳至以LabVIEW寫成之控制器作為無段變速系統之ㄧ次皮帶盤油壓值及二次皮帶盤油壓值控制之參考，構成一閉迴路控制。 本實驗成功使無段變速系統之ㄧ次皮帶盤油壓值及二次皮帶盤油壓值較原廠之設定油壓值低時，經自製之LabVIEW控制器控制一次皮帶盤及二次皮帶盤之間的減速比，證明可以在較低的主油壓值設定下進行減速比之控制。
並列摘要
Active continuously variable transmission(CVT) system can provide passengers more comfortable experience than non-continuously variable transmission system does due to the dense gear ratio. Hence, continuously variable transmission system becomes more and more popular nowadays. Continuously variable transmission system is now one of the major studies on gearbox. Continuously variable transmission system is consist by two pairs of pulley and belt. And it was control by duty cycle of solenoid valve action. The value of oil pressure was decided by speed of engine rotation. When speed of engine rotation is higher than a requirement of continuously variable transmission system. There is some power emission. So this paper trys to separate oil pressure control from speed of engine rotation. And find out the optimization of oil pressure control. The study sets the human machine interface to eliminate the rotational speed of power source influences continuously variable transmission(CVT) system by transferring the continuously variable transmission(CVT) system into inside and outside shaft independent rotate design, and using another oil pump motor to control the oil pressure of the continuously variable transmission(CVT) system. The platform uses LabVIEW as the control program and data acquisition card of national instrument company to gather parameter operation and control CVT oil pressure system, and observe if the changes of rotation speed proof fits the targets of gear ratio. The part of computer simulation oil pressure control is using gear ratio which was gathered by data acquisition system to check target of gear ratio, and then passing the messages to the controller which is written by LabVIEW and being the reference of oil pressure of the front and rear pulley in continuously variable transmission(CVT) system, to construct a close loop control system. This experience made the oil pressure of the front and rear pulley in continuously variable transmission(CVT) system lower than original sets, and proved that the control of gear ratio can be achieved in a lower system oil pressure set by LabVIEW controller.