Fuel injector and an engine including such an injector

Abstract

A fuel injector for injecting fuel into a combustion chamber, comprising an injector head (6) extending from a base (6a) to a free end (6b) along a central axis (X), the Said jetting head comprises a free outer surface (6c, 6d), which defines an inner jetting chamber (7); and at least two sets of jetting holes (10; 20; 30), each jetting hole (10; 20 ; 30) comprising a first injection hole (11; 21; 31) and at least one second injection hole (12; 22; 32), each injection hole being adapted to move along respective first and second directions (D11, D21 , D31; D12, D22, D32) inject fuel, and the first direction and the second direction form an acute angle (α) therebetween. The inner openings of all the injection holes in each group of injection holes are substantially in the same plane (P), which substantially extends transversely with respect to the central axis (X) of the injection head (6) of the injector. The injector described is particularly suitable for direct injection diesel engines.

Description

Technical field [0001] The invention relates to a fuel injector for injecting fuel into the combustion chamber of an internal combustion engine. More specifically, it relates to a fuel injector that includes an injector body for fixing to the engine; and an injection head that extends from a base connected to the injector body to A free end, the spray head includes an inner spray chamber, an outer surface extends between the base and the free end, and includes a plurality of spray holes, these spray holes are composed of at least two groups from the inner openings located in the inner spray chamber The spray holes extending to the outer opening on the outer surface, each group of spray holes includes a first spray hole and at least one second spray hole, and each spray hole is adapted to be along a respective first and second direction Inject fuel, the first and second directions form an acute angle between them in such a way that the jets from each group of injection holes interc...

AI Technical Summary

Problems solved by technology

[0004] However, it has been found that with such injectors of the prior art, the bursting of the fuel injection stream produced by a group of injection holes does not always take place in an optimal manner

It has been found that, under certain circumstances, firstly, the jets produced by a set of first and second jet holes do not occur simultaneously, which may result in one of the jets not bursting for a short period of time; secondly, said The characteristics of the first and second jets, such as their flow velocities, do not vary proportionally, thereby causing greater or lesser deflection outside the burst zone of the jet formed by the set of jet holes

Those phenomena that have a detrimental effect on the atomization of fuel, on the inhomogeneity of the air / fuel mixture in the combustion chamber and thus on polluting emissions

Although an increase in injection pressure and an increase in the number of injections per cycle are generally considered to be factors that can improve combustion, since when the injection pressure rises to its highest value, currently specified at 2000 bar, and when it is desired to reduce the injection duration to be able to Their magnitude tends to increase when increasing the number of injections in a cycle, and those phenomena are therefore all the more detrimental

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