There is no such thing as an injector, only injectors.
The fuel injector is a precision device with very high machining accuracy, which requires a wide dynamic flow range, strong anti-clogging and anti-pollution ability as well as good atomization performance. The injector receives the injection pulse signal from the ECU and precisely controls the amount of fuel injected.
The spray characteristics of the injector include atomization particle size, oil mist distribution, oil beam direction, range and diffusion cone angle. These characteristics should be in line with the requirements of the diesel combustion system, in order to make the mixture formation and combustion perfect, and obtain high power and thermal efficiency.
The diesel injection system atomizes the fuel and distributes it in the combustion chamber to mix with the air.
It mainly consists of injector nozzles and injector body, its installation position and angle on the cylinder head depends on the design of the combustion chamber.
The injector is divided into two types: open and closed. Open injector structure is simple, but poor atomization, rarely used. Closed injectors are widely used in a variety of diesel engines. The diesel engine inhales pure air during the intake stroke. Near the end of the compression stroke,
Injector injection pulse width
Diesel fuel by the injection pump will increase the oil pressure to more than 100MPa, sprayed through the injector into the cylinder, in a very short period of time and the compression of high-temperature air mixing, the formation of combustible mixture. Due to the high compression ratio of diesel engines (generally 16-22), so the end of compression when the air pressure in the cylinder up to 3.5-4.5MPa, while the temperature up to 750-1000K (and gasoline engines at this point in the mixture pressure will be 0.6-1.2MPa, the temperature up to 600-700K), much more than the diesel fuel auto-ignition temperature. Therefore, diesel fuel is sprayed into the cylinder, in a very short period of time with the air mixture will immediately ignite combustion on its own. Gas pressure in the cylinder rises rapidly to 6-9MPa, the temperature also rises to 2000-2500 K. In the high-pressure gas push, the piston downward movement and drive the crankshaft rotation and work, the same exhaust gas through the exhaust pipe into the atmosphere. [1]?
Ordinary diesel engine is driven by the engine camshaft, with the help of high-pressure oil pump will be diesel fuel delivery to the fuel chamber of each cylinder. This way of fuel supply to change with the engine speed changes, do not do the optimal amount of fuel supply at various speeds.
***Track injection fuel supply system consists of a high-pressure oil pump, public **** fuel supply pipe, injectors, electronic control unit (ECU) and some pipeline pressure sensors, each injector in the system through their respective high-pressure fuel pipe connected to the public **** fuel supply pipe, the public **** fuel supply pipe to the injector to play the role of hydraulic pressure storage. When working, the high-pressure oil pump delivers fuel to the male **** oil supply pipe with high pressure, and the high-pressure oil pump, pressure sensor and ECU form a closed-loop work, realizing precise control of the oil pressure in the male **** oil supply pipe, and completely changing the phenomenon that the oil supply pressure changes with the engine speed. Its main features are the following three aspects:
Schematic diagram of the working principle of the injector
1, injection timing and fuel metering are completely separate, injection pressure and injection process is controlled by the ECU at the right time.
2, according to the engine operating conditions to adjust the injection pressure of each cylinder, injection point, duration, so as to pursue the best control point of injection.
3. It can realize high injection pressure and pre-injection of diesel fuel.
Compared with the gasoline engine, diesel engine has a low fuel consumption rate (on average, 30% lower than the gasoline engine), and diesel fuel price is lower, so the fuel economy is better; at the same time, the diesel engine's rotational speed is generally lower than that of gasoline engines, torque is greater than that of gasoline engines, but its quality is large, noisy, high manufacturing and maintenance costs, and emissions are also poorer than that of gasoline engines. But with the development of modern technology, these shortcomings of diesel engines are gradually being overcome.
I hope I can help you solve your doubts.