Test and Optimization of a PM/EM Hybrid Electromagnetic Valve for Engines

• Main Authors: Hong-Yu Chen, 陳泓宇
• Other Authors: Yao-Jung Shiao
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/xrdswa

碩士 === 國立臺北科技大學 === 車輛工程系所 === 100 === Improving internal combustion engines is the current developing trend of vehicle power train system, in which this trend mainly focuses on developing internal combustion engines with low fuel consumption, low emission pollution, and better engine efficiency. Electromagnetic valve (EMV) system for camless engine could be controlled independently without camshaft driving, so EMV could provide valve timing with high degree of freedom compared with the traditional camshaft-driven valve structure. Conventional electromagnetic valve system uses double solenoids to maintain valve at its opening or closing position. This design consumes higher energy. A new type of EMV system was proposed in this study. This EMV adopts hybrid EMV design of permanent magnet and electromagnet (PM/EM) to reduce operational actuating energy, and also uses technique of forward bypassed magnetic flux to control the valve opening and closing. This forward bypassed magnetic flux, in which the demagnetization of permanent magnet could be avoided, is different from general technique of backward counterweight magnetic flux used in conventional EMVs. The horizontally symmetrical magnetic flux could increase the holding force of valve at valve opening and closing positions. This study discussed the factors that influenced hybrid electromagnetic valve, and performed optimum analysis about this electromagnetic valve. The factors that had not been considered in the past design were revised one by one. Simulation of magnetic field about EMV was performed to evaluate and the performance of valve under the influence of magnetic field. The influence of magnetic saturation in EMV was also discussed, so as to further investigate how to avoid magnetic saturation during design stage. Thus, the optimum design of EMV with PM/EM hybrid was obtained so as to confirm the function of bypassed magnetic flux in EMV. Besides, this study established an experimental platform for testing performances of electromagnetic valve, i.e., EMV function, current magnetic performance, and valve motion This EMV is expected to be actually used in an engine in the near future.