How the fuel injector works

A diesel injection system atomizes fuel and distributes it in the combustion chamber to mix with air.
It is mainly composed of an oil injector and an oil injector body, and its installation position and Angle on the cylinder head depend on the design of the combustion chamber.
Fuel injectors are divided into two types: open and closed. The open injector has simple structure, but poor atomization, and is rarely used. Closed fuel injectors are widely used in various diesel engines. Diesel engines suck in pure air during the intake stroke. When the compression stroke is near the end, the diesel oil is raised to more than 100MPa by the injection pump, injected into the cylinder through the injector, and mixed with the compressed high temperature air in a very short time to form a combustible mixture. Due to the high compression ratio of the diesel engine (generally 16-22), the air pressure in the cylinder can reach 3.5-4.5MPa at the end of compression, and the temperature can reach 750-1000K (while the gasoline engine's mixture pressure at this time will be 0.6-1.2MPa, and the temperature can reach 600-700K), which greatly exceeds the spontaneous combustion temperature of diesel. Therefore, after the diesel oil is injected into the cylinder, it immediately ignits itself after mixing with the air in a very short time. The air pressure in the cylinder rose rapidly to 6-9MPa, and the temperature also rose to 2000-2500K. Under the push of high pressure gas, the piston moves down and drives the crankshaft to rotate and do work, and the exhaust gas is also discharged into the atmosphere through the exhaust pipe.
The ordinary diesel engine is driven by the engine camshaft, and the diesel is transported to the cylinder fuel chamber by means of a high-pressure oil pump. This kind of oil supply method changes with the change of engine speed, and can not do the best oil supply under various speeds.