Electronically Controlled Gasoline Direct Injection System

With the problems of short of energy and environment pollution becoming more and more distinct, Gasoline engine lean burn changes its mode of burn, which can reduce fuel consumption and emissions greatly. Gasoline direct injection (GDI) is the most effective means that organizes lean burn in gasoline engine. So people attach more importance to the research and development of the engine electronic control technology combined with GDI, which has been developping quickly in recent years. It is considered one important direction for internal-combustion engine to solve the energy and environment problems. Many research institutes and automobile manufacturers apply themselves to studying on GDI engine and manufacture cars equipped with GDI engine.Based on the research on GDI technology, an electronic controlled gasoline direct injection system used for test has been developped successfully. Change was made to the combustion system of the testing engine. The high pressure fuel supply system for GDI works reliably. Fuel supply pressure is steady and adjustable from 2 to 12MPa. Direct injection was made by means of normal needle valve injector equipped with electromagnetic valve. Through the calibration of the injector's dynamic characteristic, injection pressure was set at 8MPa. The gasoline atomization characteristic was also discussed.Based on the study on the control strategy and project, a control project was put forward, which is based on PC. Multi-lab card and SCM system were also applied. Hardware and software were designed, which carry out some fuctions such as data collection and communication, fuel injection and multiple times ignition control. Space remains for further fuction.The influence of multiple times ignition on idle stability was studied through engine experiments. It indicates that multiple times ignition improves the idle stability, especially when spark advance differs from better value. Compared with the carburetor condition, the idle emission of GDI declines distinctly in HC and CO, varies little in NOx. In order to improve the idle stability and reduce the emissions more, further research and optimization design need to be made.