【作者】 刘迪卿；

【导师】 邓康耀； 宋义忠；

【作者基本信息】 上海交通大学 ， 车辆工程， 2011， 硕士

【摘要】 随着国家对环境保护要求的日益严格,电子控制汽油机燃油喷射系统在我国汽车工业中得到广泛应用,给我国汽车技术带来巨大的进步。同时,也暴露出了它所存在的各种问题,如何在可变条件下精确控制进气流量就是其中难点之一。本文是针对双可变进排气门汽油机车型排放研究,发现车辆在排放试验中出现CO过高的情况,严重影响国家强检排放试验的顺利进行。结合热线式进气流量传感器在发生瞬态变化时,容易受到紊流的影响而产生超调或延迟信号这一特性和试验数据,将问题锁定在瞬态进气流量传感器信号失真所致。针对根本原因,基于进气歧管压力传感器、发动机转速、进气门正时和排气门正时建立发动机进气模型,以便在瞬态工况取代进气流量传感器得到精确的进气数据。精确的进气流量加上合适空燃比的控制解决瞬态CO突跳问题,使得整车排放达到国四排放法规要求。该研究不仅为企业按时将有竞争力的车型投放市场提供有力的技术支持,同时也为提高本地自主研发能力提供借鉴。为公司标定工程师后续配备双可变进排气门汽油机车型的国四乃至国五排放问题的解决指明了方向。目前该方法的使用在后续车型中取得了较好的效果。更多还原

【Abstract】 With the requirements by the Government to protect environment, electrical fuel injection system control was used much more popular in engine, as bring us not as a great progress for China automobile technical, but also some hot issues, such as accuracy control on intake air flow in the variable conditions.This paper focus on the emission research in the vehicle equipped with DVVT engine. CO exhausts exorbitance caused by inaccuracy intake air flow in the emission test has an impact on national compulsion emission test. Considered hot-wire intake manifold airflow(MAF) sensor characteristic and the test data, which shows the MAF sensor signal will be flare or delay by turbulence in transient mode, it is found that the root cause is MAF sensor signal distortion.According the root cause the intake air model is created including intake manifold air pressure, engine RPM, intake phaser and exhaust phaser, which can replace the MAF sensor signal with accuracy intake air flow calculated. Accuracy intake air flow and air-fuel ratio control appropriately can solve this issue, as help the vehicle meet the emission requirement of China Phase IV.This research not only makes a competitive car to release in market on time but also improves the ability to provide independent research and development of local reference. It pointed out the direction for engine calibrator to meet the requirement of China Phase IV and Phase V emission regulation in our company. The method currently used in subsequent models achieved good results.更多还原