The Design Of The Electronic Controlled System & The Research On The Optimization Test For The NA20S Gasoline Engine

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.