陽毅平臺灣大學：機械工程學研究所徐家鴻Xu, Jia-HongJia-HongXu2007-11-282018-06-282007-11-282018-06-282007http://ntur.lib.ntu.edu.tw//handle/246246/61143發展高效率、低污染動力系統之關鍵技術，已是內燃機引擎的重要目標，然而可變汽門正時機制，對於改善引擎性能，為有效且必要之手段。電磁式汽門機構使用電磁螺線管式驅動汽門，免除凸輪軸，各汽門可獨立控制。本文的研究主題為利用高磁能積永磁與線圈激磁之混合磁動勢，結合低電功率之概念，開發出新型電磁式汽門機構來達到性能需求。研究中首先評估引擎操作上的限制，制訂電磁式汽門動力需求，藉由電磁分析建立數學模型，透過最佳化軟體達到最佳設計，經由有限元素分析軟體驗證，完成電磁式汽門系統雛型建構，並且加入熱傳暫態與穩態模擬分析、振動模態分析、及運動與頻域響應性能分析。本研究的具體貢獻包括，新型電磁式汽門機構雛型輕量化、結構簡單、耐高溫環境、無需起始電流、改善電流制動時機、高速響應以及易於控制等優勢。最後經由實驗結果可獲知感測器回授訊號擁有高線性度，未來加入汽門正時控制系統後，將大幅提升引擎性能。For the sake of the environmental consciousness rising, it is necessary to improve internal combustion engine for high efficiency. Electromechanical valve actuator system (EMVA) uses solenoid to drive each valve independently for achieving variable valve timing (VVT). The main issues of the present research (EMVA) aims to the lower power source needed and hybrid magneto-motive force (MMF) usage. The design procedures depicted in the order as: establish mathematical model via magnetic circuit, optimization, and verified by FEA. The proposed prototype shows a lot of advantages comparing with conventional EMV as following: compact, high temperature tolerance, fast response, no starting current, different current actuating timing and easy for control. It is expected to accomplish VVT in the future achievements.摘要 i ABSTRACT ii Contents iii List of Table vi List of Figure vii 1. Introduction 1 1-1. Overview 1 1-2. Literature Review 4 1-3. The Objective and Scope of the Work 11 1-4. Organization of the Thesis 12 2. Electromechanical Valve Actuation Mechanism 15 2-1. Specifications of EMVA 16 2-1-1. Fast transition time 16 2-1-2. Soft landing 18 2-1-3. Space limit 19 2-1-4. Fail-safe 20 2-2. Helical Compression Springs 21 2-2-1. Restricts of the spring 21 2-2-2. Design of the spring 23 2-3. Position Sensor 31 2-3-1. Sensor configuration 31 2-3-2. Magnetic circuit model of position sensor 32 2-3-3. Ratio metric linear Hall Effect sensor for high temperature 34 2-3-4. Sensor verification by FEA 35 3. Preliminary Design of Electromechanical Valve Actuator 37 3-1. Preface 37 3-2. Design Concepts and Objectives 39 3-3. Energy Conservation and Energy Conversion 42 3-4. Permanent Magnet Dual Channel Parallel Polarized Method 44 3-4-1. Principle of the concepts 45 3-4-2. Holding force 48 3-4-3. The soft magnetic materials 52 3-4-4. The hard magnetic materials 54 3-5. Brief Summary 59 3-6. Modeling of the EMVA System 61 3-6-1. Electrical subsystem 61 3-6-2. Mechanical subsystem 62 3-6-3. Electromechanical coupling subsystem 64 4. Multifunctional Optimal Design for EMVA system 71 4-1. Optimization Tool 71 4-1-1. The flowchart of MOST [35-37] 72 4-1-2. Optimal solution 86 4-2. Finite Element Analysis 88 4-2-1. Introduction of the finite element tool 88 4-2-2. The distribution of flux density for whole system 89 4-2-3. Analysis of the holding force 92 4-3. Thermal Analysis 93 4-3-1. Thermal distribution with the EMVA system 93 4-3-2. The correlation with the holding force and temperature 95 4-4. Activation Current 97 4-4-1. Definition of activation current 99 5. Experimental Systems and Results 109 5-1. Manufacturing 109 5-2. Linearity Test for Position Sensors 112 5-3. Characteristic of Holding Force 115 5-4. Experimental Results for Variable Temperatures with EMVA 121 5-5. The Test of Whole EMVA System 123 5-6. Experimental Equipment 128 6. Conclusions 131 6-1. Discussion & Main Contribution 131 6-2. Future Work 132 7. Bibliography 135 Appendix A 139 Appendix B 140 Appendix C 140 Appendix D 1413613322 bytesapplication/pdfen-US無凸輪引擎電磁式汽門混合磁動勢雙通道平行磁路camless engineelectromechanical valve actuatorhybrid MMFdual-channel parallel polarized methodthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/61143/1/ntu-96-R94522826-1.pdf