Locomotive diesel engine nozzle and manufacturing method thereof

Abstract

A locomotive diesel engine nozzle comprises a nozzle body and a spraying hole, a hole opening of the spraying hole inlet end of the nozzle is a gradual-shrinking hole, a hole opening of the spraying hole outlet end is a gradual-expanding hole, the round hole cross section of the juncture of the gradual-shrinking hole and the gradual-expanding hole is the juncture section with the minimum spraying hole diameter, the gradual-shrinking hole and the juncture section are in circular-arc transition, the gradual-expanding hole and the juncture section are in circular-arc transition, and therefore the spraying hole with the inlet end and the outlet end in trumpet shapes is formed; the hole opening diameter of the gradual-shrinking hole and the hole opening diameter of the gradual-expanding hole are the same, and the position of the spraying hole juncture section is located on the center point of the middle axis of the spraying hole or the position between the center point of the middle axis of the spraying hole and the outlet end hole opening that is the gradual-expanding hole. According to the nozzle, through optimizing of the section shape of the spraying hole, under the same pressure difference, diesel oil jetting speed is higher, the cavitation effect and the liquid flow turbulence are enhanced, the atomizing effect is better, the friction between diesel oil and the inner wall of a nozzle cavity is reduced, and the manufacturing method is scientific and reliable.

Description

technical field [0001] The invention relates to a diesel engine component and a manufacturing method, in particular to a locomotive diesel engine nozzle and a manufacturing method thereof. Background technique [0002] In the fuel injection system of diesel locomotives, the fuel injector plays an important role. The nozzle is the final execution part of the diesel engine injection system. The flow characteristics inside the nozzle directly affect the quality of fuel injection and atomization, which in turn affects the subsequent combustion effect and also Directly affect the economy, power and emission characteristics of the diesel engine; [0003] In traditional fuel injectors, the nozzle holes are mostly in the shape of a cylinder with equal diameters, that is, the diameter of the nozzle holes remains unchanged from the inlet end to the outlet end, (for example, figure 1 280A injector nozzle shown), the problem is: [0004] 1. After the needle valve is lifted, there is ...

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Problems solved by technology

[0004] 1. After the needle valve is lifted, there is a huge pressure difference between the oil inlet end and the injection port, and the main pressure drop area is concentrated from the pressure chamber to the inlet end of the injection hole. In this area, the shear force of the oil on the inner wall increases, and the oil The liquid is easy to generate eddies in the pressure chamber, which will aggravate the energy dissipation; after that, the local turbulent flow will generate small eddies, which will affect the smoothness and flow of the flow field, so the wear in this area is usually very large; it directly affects the life of the nozzle;

[0005] 2. In addition, with the increase of the pressure difference, the fuel flow in the nozzle is prone to cavitation areas. On the one hand, the turbulent flow and atomization ability are enhanced, and on the other hand, the flow efficiency of the nozzle is reduced, which affects the effect of atomization and the overall performance of the engine. performance

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