全可变液压气门机构改善汽油机燃油经济性的试验研究

发布时间：2018-01-06 23:07

本文关键词：全可变液压气门机构改善汽油机燃油经济性的试验研究　出处：《山东大学》2016年硕士论文　论文类型：学位论文

【摘要】：全可变气门机构(Fully Variable Valve System,简称FWS)能够使气门最大升程、气门开启持续角及配气相位三者连续可变。本文的研究对象为搭载有FWS系统的BJ486EQ无节气门汽油机(简称,FWS样机),在FWS样机上进行了进气性能和燃烧性能的试验研究。通过与原机试验结果对比,详细分析了FWS系统对燃烧过程及燃油经济性的影响。主要研究内容如下：第一,样机的改进和试验台架的搭建。在BJ486EQ汽油机上安装了FWS系统,并对相关系统进行了改进设计；为研究FWS系统对燃油经济性的影响,搭建了发动机试验台架,改进了相应试验设施和试验测试系统。第二,设计模拟信号输出装置。通过该装置向发动机ECU输入进气压力和节气门开度的模拟电压信号,来控制FWS样机工作过程中的喷油量。第三,FWS系统对泵气损失的影响。研究发现,FWS能够采用进气门早关(EIVC)的方式控制进入气缸内的工质数量,从而取消节气门,这种无节气门汽油机将大幅度地降低泵气损失。在平均有效压力为0.19MPa时,FWS样机的泵气损失仅为原机的23.5%。第四,FWS系统对发动机燃烧过程的影响。通过试验测量进气流量和缸内压力,分析了无节气门汽油机燃烧放热规律、缸内循环变动及燃油经济性。研究结果表明,与原机相比,在相同的进气质量流量下FWS样机在压缩终点的缸内压力温度都偏低,导致FWS样机滞燃期过长,燃烧速率慢,后燃现象明显,循环变动率高,使燃烧性能恶化。第五,点火提前角对FWS样机燃烧过程的影响。研究表明,随点火提前角的增大,缸内最高燃烧压力升高,放热重心越靠近上止点。FWS系统可以在一定程度上改善无节气门汽油机的燃油经济性。
[Abstract]:Fvva (Fully Variable Valve System, referred to as FWS) can make the maximum valve lift, valve opening duration and gas distribution phase three continuous variable. The research object of this paper is equipped with FWS BJ486EQ system (referred to as unthrottled gasoline engines, FWS, prototype) test on the intake performance and combustion performance in the FWS prototype. By comparing with the original test results, a detailed analysis of the FWS system on the combustion process and the influence of fuel economy. The main research contents are as follows: first, improvement of the sample and the test bench of the building. The FWS system is installed in the BJ486EQ gasoline engine, and the system has been improved design; in order to study the effect of FWS system on the fuel economy of the engine test bench was set up and improve the corresponding test facility and test system. Second, design analog signal output device through the device to start. ECU input inlet pressure and solar term door open analog voltage signal of the fuel injection quantity to control the FWS prototype in the working process. Third. The effect of FWS system on the pumping loss. The study found that FWS can use early intake valve closing (EIVC) to control the way to enter the number of refrigerant inside the cylinder, so as to cancel the solar term the door, the unthrottled gasoline engines will greatly reduce the pumping loss. The average effective pressure of 0.19MPa, the prototype of FWS pump gas loss is only fourth of the original machine 23.5%., effect of FWS system on the engine combustion process. By measuring the intake air flow test and cylinder pressure of unthrottled gasoline combustion law, cyclic variation and fuel economy in the cylinder. The results show that, compared with the original engine, the air mass flow under the same pressure at the end point of the FWS prototype compression cylinder temperature is low, resulting in the prototype of FWS ignition delay period is too long, burning Burn rate is slow, after burning phenomenon obviously, cycle variation rate is high, the combustion performance deterioration. In fifth, the ignition advance angle of the FWS prototype of the combustion process effect. The results show that with the increase of the ignition advance angle, the maximum combustion pressure, heat release of gravity closer to the fuel economy of the TDC.FWS system can improve the throttle gasoline engine to a certain extent.

【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U464.171

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