JPS5843669Y2 - fuel injection nozzle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a fuel injection nozzle for an internal combustion engine.

The injection performance of a fuel injection nozzle for an internal combustion engine determines the performance of the engine.

In other words, it is an important factor that determines the quality of combustion.

Particularly in direct injection type fuel injection nozzles, so-called hole nozzles, the spray is so important that it determines combustion.

As is well known, in order to improve combustion, it is necessary to improve the mixing of fuel and air, but when the mixing period is extremely short as in diesel engines, it is difficult to spread the fuel particles uniformly throughout the combustion chamber. The problem is how to distribute it.

By the way, various attempts have been made to improve mixing by changing the shape of the combustion chamber or by creating a vortex in the combustion air, but the injection holes of conventional fuel injection nozzles are circular.
Since the cross section of the spray is circular, the fuel distribution is uneven and combustion cannot be improved as expected.

Furthermore, with recent advances in processing technology, particularly electrical discharge machining, laser processing, etc., it has become possible to process nozzle holes, which were previously limited to circular shapes, to shapes that were previously impossible.

With the advancement of such processing technology, elongated nozzle holes have already been considered, but even in this case, the ejected jet tends to coalesce into one as it goes forward, so it ends up being approximately circular. As a result, the effect of obtaining uniform distribution could not be sufficiently achieved.

Now, Fig. 1 A 2 ports are the spray A' in the case of the conventional direct injection type.
and the shape of the combustion chamber, and Figure 2 shows the spray A in the case of the swirl chamber type.
', but in any case, the distribution state of ',
The air in the area indicated by `` in Figure 2 was difficult to utilize, resulting in poor combustion conditions, making it impossible to improve performance, and causing smoke to worsen.

Accordingly, an object of the present invention is to provide a fuel injection nozzle that can inject fuel substantially uniformly over a wide range within a combustion chamber.

Embodiments of the present invention will be described below with reference to FIGS. 3 to 5.

FIG. 3 shows the tip of the nozzle according to the present invention.
It is shaped like glasses.

The central axis X in the longitudinal direction of the nozzle hole is arranged at an angle θ with respect to the central axis Y of the nozzle N.

Usually, a plurality of nozzle holes are provided at the tip of the nozzle, and the angle θ here is the angle when the nozzle hole is projected onto the axis Y.
The value is between 0° and 90'.

This angle is set experimentally and empirically depending on the structure of the combustion chamber, the direction of the swirl, its strength, etc., and better combustion action can be obtained.

Figure 4A shows the spray A' when the conventional circular nozzle hole 1' is used, and the spray A' when the conventional oval nozzle hole 1'' is used.The penetrating force is strongest near the center, and the fuel particles It's getting denser.

In the case of circular nozzle holes 1' and oval nozzle holes 1'', as mentioned above, the air in the areas indicated by ``A'' in Figure 1 and ``in Figure 2'' is difficult to utilize, resulting in poor combustion conditions and poor performance. It cannot be measured and also makes the smoke worse.

Figure 4 (c) shows spray A when using the spectacle-shaped nozzle 1 of the present invention.
, because of the two enlarged parts 1b, 1b and the elongated part 1a, the penetrating force near the center becomes stronger and the density of fuel particles increases only in that part, as in the conventional circular nozzle hole 1'. Instead, as shown in the cross-sectional shape of spray A in the figure, the two central parts and the elongated part connecting them cause the spray to spread appropriately, and the fuel particle density becomes uniform throughout spray A, resulting in a mixture of air and fuel. is done uniformly.

FIG. 5A shows the manner in which the swirl Sw flows in from the intake pipe S. In the figure, P is the piston and C is the combustion chamber.

Therefore, a preferable distribution state can be obtained as shown in the opening of FIG.

That is, the opening in FIG. 5 shows the distribution of spray A in the combustion chamber when the spectacle-shaped nozzle hole of the present invention is used, and it can be seen that the air in part B is utilized better than when the conventional circular nozzle hole is used.

[Brief explanation of the drawing]

Figure 1A shows the distribution of spray in the combustion chamber when a conventional circular nozzle hole is used, where A is a plan view and the mouth is a sectional view. FIG. 2 is a sectional view showing the distribution of spray in a combustion chamber of another shape. FIG. 3 is a plan view of the tip of the injection valve and the spectacle-shaped nozzle hole according to the present invention. Fig. 4 A shows the state of the spray injected from the nozzle hole, A shows the state of the spray injected from the nozzle hole, A shows the case with the conventional circular nozzle hole, the mouth shows the case with the conventional oblong nozzle hole, and C shows the state of the spray according to the present invention. The case with a shaped nozzle hole is shown. FIG. 5A is a schematic diagram of a combustion chamber using a spectacle-shaped nozzle according to the present invention, and FIG. 5B is a plan view showing the distribution of spray in the combustion chamber. 1... Spectacle-shaped nozzle hole, 1a... Elongated central sound hole of the nozzle hole 1b... Enlarged portions on both sides of the nozzle hole.

Claims (1)

[Scope of utility model registration request] In a fuel injection nozzle for an internal combustion engine, the shape of the nozzle hole that injects fuel into the combustion chamber is a glasses shape with an elongated central part and enlarged sides, and the central axis in the longitudinal direction of the nozzle hole is the center of the fuel injection nozzle. A fuel injection nozzle characterized by having an angle with respect to the axis.