ELECTRONIC FUEL INJECTION 车辆工程专业英语教学PPT课件.pptx

ELECTRONIC FUEL INJECTION （2）;;;Fig. 4-29. Electronic throttle sends accelerator signal to Motronic control unit . DC motor moves throttle valve, modified by engine temperature, idle rpm, and maximum rpm;;;Gasoline Direct Injection Conventional gasoline engines are designed to use an electronic fuel injection system, replacing the traditional mechanical carburetion system. Multi-point injection (MPI), where the fuel is injected through each intake port, is currently one of the most widely used systems. Although MPI provides a drastic improvement in response and combustion quality, it is still limited due to fuel and air mixing prior to entering the cylinder. To further increase response time and combustion efficiency, while lowering fuel consumption and increasing output, systems may use direct injection. Gasoline direct injection engines are engineered to inject the gasoline directly into the cylinder in a manner similar to diesel direct injection engines.; Direct injection is designed to allow greater control and precision, resulting in better fuel economy. This is accomplished by enabling combustion of an ultra-lean mixture under many operating conditions. Direct injection is also designed to allow higher compression ratios, delivering higher performance with lower fuel consumption. Currently, direct injection gasoline engines are being deployed throughout the world in passenger cars. Mitsubishi GDI Mitsubishi Motors is aiming to achieve both low fuel consumption and high output. MMC is a world forerunner in the development of direct cylinder injection gasoline engines, known as GDI, which were first introduced in the 1996 Galant. GDI supplies fuel directly to the inside of the cylinder (Figure). A variety of air-fuel mixtures can be created according to changes in the fuel injection timing. ;Fig.4-1 Mitsubishi direct cylinder injection gasoline engine;ELECTRONIC FUEL INJECTION;2.7.4 Common Rail Injection System (CR System) All previou