Fuel injector

Abstract

The invention discloses a fuel injector. The fuel injector comprises a needle valve and a valve seat, wherein the needle valve comprises a needle valve head and a needle valve tail; the needle valve tail is in a cavity structure; a cylindrical tube body forms between the surface of the needle valve head and the inner ring surface of the valve seat, and a gradually shrunk and expanded flow pipeline of the fuel injector forms in the cavity between the cylindrical tube body and the needle valve tail. According to the fuel injector, the fuel injection speed at the injection hole of the fuel injector can be improved, the fuel atomizing characteristics of the injection hole outlet are improved without increasing external conditions such as increasing of injection pressure or other parts, and the eddy current at the nozzle outlet can be further increased under the action of the aerodynamic force of the supersonic speed airflow to atomize towards the axis, so that the atomized particle size can be further detailed and the atomizing characteristics can be improved.

Description

technical field [0001] The present application relates to the field of in-cylinder fuel injection systems of aero-engines, in particular to a fuel injector. Background technique [0002] A fuel injector is a device that premixes a certain amount of fuel at a certain pressure with compressed air and injects them into the cylinder of an aeroengine. Aeroengines mainly use kerosene as the fuel medium. But kerosene is less evaporative, and there is not enough time for the fuel to evaporate before the spark plug ignites during the piston engine's working cycle. In order to make the mixed fuel ignite and burn better, it is required to refine the particle size of the fuel as much as possible to shorten the evaporation time of the fuel. [0003] At present, in order to make the fuel burn more fully, the following measures are usually adopted: 1) high-pressure injection is used; 2) the diameter of the nozzle hole is reduced; 3) an atomizer is set. [0004] In order to obtain a good...

AI Technical Summary

Problems solved by technology

[0007] Setting the atomizer increases the number of parts of the air-assisted atomizing injector, increases the processing cost, and increases the difficulty of assembly

In addition, multiple disks are stacked in the sleeve, which adds a lot of uncertain factors to the flow of the mixture of air and fuel. The circumferential arrangement and mutual position of each disk will have a great impact on the flow of the entire fuel mixture.

Multiple disks are stacked in the sleeve, so that residual fuel is extremely easy to accumulate in the edge gap of the disk with a certain shape, which is easy to cause the nozzle hole to be blocked and carbon deposits, which is not conducive to the formation of a good spray

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