What are the ways to supply oil to automobiles?

Carburetor is a mechanical device that mixes a certain proportion of gasoline with air under the vacuum generated by engine operation. It is a widely used fuel supply method for traditional gasoline engines. However, it often leads to insufficient combustion of the engine, the content of harmful substances in the exhaust gas can not meet the increasingly strict emission regulations, and at the same time, it will produce higher fuel consumption, which has been gradually eliminated.

2. Single point EFI:

It means that each cylinder has only one injector, which is located on the intake pipe before being divided into intake manifolds, and its fuel injection quantity depends on the throttle valve. Due to the different length and position of intake manifold, the amount and time of mixed oil and gas injected into each cylinder are inconsistent, resulting in different working conditions of each cylinder. It has the advantages of simple structure and low cost.

3. Multiple injections:

Fuel injectors are installed on the intake pipes of each cylinder, and gasoline is injected into the cylinder from multiple places (at least one injection point per cylinder). The control of air-fuel ratio is more accurate than that of single-point injection, and injection can be carried out according to the timing, and the injection quantity and timing can be accurately controlled, so the multi-point injection engine has better emissions and is more economical and fuel-efficient.

4. Direct injection:

It means that the fuel injector is arranged between the intake valve and the exhaust valve, so that high-pressure fuel can be directly injected into the combustion chamber to achieve stable and efficient combustion. The advantage of direct injection only lies in low load. At low load, the amount of oil sprayed by the injector is the least, which is concentrated around the spark plug, and the rest of the cylinder is air. During combustion, the air layer will isolate the heat, which can reduce the heat transfer to the cylinder wall, thus reducing the heat loss and improving the thermal efficiency of the engine.

Attachment: Advantages of Direct Injection in Engine Cylinder:

Low fuel consumption and high power. The air-fuel ratio reaches 40: 1 (the air-fuel ratio of general gasoline engines is 14.7: 1), which is called "lean burn".

The upper half of the piston in the engine is spherical and the other half is a wall. Air rushes in from the valve and forms a vortex motion under the compression of the piston. When the compression stroke is about to end, the fuel injector at the top of the combustion chamber begins to inject fuel, and gasoline and air form a mixed gas under the action of vortex motion. This fast-rotating mixed gas is layered, and the closer it is to the spark plug, the thicker it is, and it is easy to ignite and do work. The compression ratio is as high as 12, and the power and torque are 10% higher than those of ordinary engines with the same displacement.