【作者】 杨河洲；

【导师】 龚金科； 凌建寿；

【作者基本信息】 湖南大学 ， 机械工程， 2005， 硕士

【摘要】 随着我国经济的发展，汽车工业近几年进入了快速发展阶段，机动车的排放法规要求也更加严格，这就使得机动车节能及排放控制技术的研究变得日益重要。本文根据车用汽油机产品国内实际情况，在对车用汽油机电控喷射系统原理分析研究的基础上，针对NA20S型化油器汽油机，设计开发出了一套多点顺序电控汽油喷射(MFI)系统-CY2000汽油机电控系统，并对原化油器汽油机进行了电喷改造。该系统采用“速度-密度”方式的汽油喷射系统。该系统具有结构简单、性能可靠、性价比较高等优点。本文对汽油机的控制理论进行了较为深入的研究，并建立了汽油机进气压力及燃料喷射等汽油机控制计算模型。本文进行了CY2000汽油机电控系统控制程序及结构的设计和开发，以及空燃比控制、点火提前角控制、燃料喷射修正控制等程序的设计。并根据国内实际情况设计选定了CY2000汽油机电控系统的主要零部件。本文进行了电控汽油机进气系统的设计。针对进气歧管的设计要求，从提高充气效率的途径入手，分析了进气歧管的长度、管径、稳压箱容积三个主要结构参数对充气系数的影响，在此基础上充分考虑到装配工艺要求及原机的实际情况及与原机的相匹配性，设计了多点燃油电控喷射进气歧管。经台架性能试验对比，该进气歧管效果良好，对提高发动机性能起到良好的作用。由于车用发动机经常工作于不同的工况和环境，为了对其进行精确控制，在进行了汽油机的基础标定后，又对采用了NA20S电控汽油机的D22皮卡车进行了整车优化标定，如整车的高温、高原、高寒标定及整车排放标定试验。标定完成后进行了NA20S电控汽油机与原化油器机的发动机性能及整车性能的对比试验，结果表明，在动力性、经济性及排放方面得到了明显改善，发动机最大功率提高了7． 78％，最大扭矩提高了5． 27％，最低燃油消耗率降低了25． 25％，整车排放达到了GB18352． 2-2001(欧Ⅱ标准)中对M1类车的排放要求，整车最高车速由155km／h提高到170km／h，加速性能的改善也非常明显，整车等速油耗(50km／h)也由9． 89 l／100km降低为7． 3l／100km。试验结果证明本文开发的CY2000汽油机电控系统具有良好的技术性能，该系统所匹配的NA20S电控汽油机能够满足了目前国内车辆对汽油机的性能要求，具有很高的实用价值。随着2008年奥林匹克运动会即将在北京的举办，中国今年推出了机动车欧Ⅲ排放法规，2005年7月北京将要提前实施欧Ⅲ排放法规。本文最后对满足欧Ⅲ排放标准的冷起动阶段尾气后处理措施进行了一定的研究，并对NA20S电控汽油机工程硕士学位论文为满足欧m排放采用的后处理措施进行了设计和技术准备。关键词:汽油机;电控系统;进气歧管;排放;空燃比;点火提前角;优化标定异更多还原

【Abstract】 With the development of Chinese economic, the automobile industry is quickly developing in recently, and the vehicle emission law is becoming very strict increasingly. So the scientific technology research of the vehicle emission control and economize on energy is very important increasingly.According to the using of the vehicle gasoline engine in our country, and on the basis of the study in the gasoline engine electronic control theory, a electronic controlled gasoline multi-point injection system-CY2000 system was designed and developed by author for the NA20S engine, and applied to the original engine. CY2000 is a speed-density controlled system. It has a simple structure, credible performance and cheap cost characteristic.With the deep study on the gasoline engine electronic control theory, make out the intake air pressure model and the fuel injected model of the gasoline engine controlled models.Design the flow process diagram and the frame of the CY2000 system. Design the flow process diagram of the A/F control, the ignition advance control and the fuel injection modify control. Select the main part of the CY2000system based on the using of the vehicle.The design features of intake manifold are described in this dissertation. The factors influencing the intake air factor such as the intake manifold structure parameters: length, diameter and the volume of steady-pressure case were analyzed in order to increase intake efficiency. A specialized intake manifold for the multi-point injection electronic control system was designed and matched with the original engine according the requirements of assemble and techniques. According to the compare test of the engine performance, the new intake manifold could increase the engine performance.Because the vehicle engine often works in the different operating condition an environment, we optimization calibrated the D22 Pickup equipped with the NA20S electronic control gasoline engine after the optimization calibration of engine parameters in order to control it accurately. Such as the high temperature optimization calibration, the cold temperature optimization calibration, the altiplano optimization calibration and the vehicle emission optimization calibration. After optimization calibration, we make the engine performance test and the vehicle performance compare with the original engine, the result values is very well, the engine maximum powerincreases by 7.78%,the maximum torque increases by 5.27%, the minimum fuel consumption decreases by 25.25 % ,the vehicle emission could meet the national regulation GB18352.2-2001 (Euro-II) type Ml, the highest speed increases from 155km/h to 170km/h, the acceleration characteristics become improved, the fuel consumption in 50km/h reduces from 9.89//100km to7.3//100km.All the test results demonstrate that the CY2000 system has a well performance, and the NA20S electronic controlled gasoline engine could meet the using requirement of the vehicle at present.With the 2008 Olympic game will hold in Beijing. The vehicle EuroIIIemission regulation will be executed, and Beijing will carry out the vehicle EuroIIIemission regulation on 1st July, 2005. At the end of the dissertation, we study the emission control of the cold starting phase in EuroIIIemission regulation, and do some technical prepare of the NA20S engine for the EuroIIIemission.更多还原