Research On Automotive Exhaust Based On Intake Airflow Veracity

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.