Direct injection engine and electronic injection engine are two types of engines commonly used in construction machinery and equipment. Due to the different physical and chemical properties of diesel and gasoline, diesel engines and gasoline engines are very different in structure. Since the engines used in construction machinery are basically diesel engines, this article introduces the direct injection diesel engine and the electronic injection diesel engine.
The direct injection engine uses mechanical linkage to control the injection time and quantity. The direct injection engine mainly pressurizes the diesel oil through a high-pressure oil pump, and then atomizes the diesel oil through a mechanical spray nozzle. The characteristic of direct injection engine is to mechanically control the injection time and quantity of fuel injector. The atomization effect is poor because of the low injection pressure. The control of fuel injection by the fuel system of direct injection engine only depends on the system pressure formed by the engine on the fuel system under different working conditions. The fuel supply system injects fuel into the engine under different working conditions according to the working pressure. As the fuel supply of direct injection engine only depends on the system pressure, it is easy to cause that the required fuel can not be supplied accurately according to different working conditions, affecting the normal operation and service life of the engine.
The electronic injection engine uses sensor detection technology to detect the working state of the engine under different working conditions, such as pressure, temperature, air intake, etc. The most reasonable system working pressure and required fuel under different working conditions are preset in the computer. In this way, the computer can monitor all kinds of engine working data in real time under different working conditions, and accurately supply fuel according to different working conditions. And the fuel supply of the system depends on the fuel supply time, that is, the computer turns on the electrical pulse of the fuel injector according to the engine working condition determined by the monitoring data. In this way, the effect of oil saving and noise reduction is achieved, and the service life is also extended.
High pressure common rail technology plays a very important role in achieving the above improvement. Most EFI engines use high-pressure common rail technology. The high-pressure common rail is a high-pressure energy storage rail, which is used to temporarily store the high-pressure fuel produced by the fuel pump. In addition, high pressure common rail technology can also achieve ultra-high fuel injection pressure. The higher the injection pressure, the more fully the fuel atomization, and the higher the combustion efficiency.
