JPH05272432A - Fuel injecting valve - Google Patents

Abstract

PURPOSE:To realize a flat and thin fuel spray so as to increase combustion speed and reduce generation of NOx by forming a single slit-like injecting hole which is bored in a nozzle tip. CONSTITUTION:A fuel injecting valve is provided with a nozzle tip 1 and a fuel injecting hole 2. The fuel injecting hole 2 is formed into a single slit having the same flow rate characteristic, i.e., a product of a flow rate coefficient multiplied by an injecting hole area as that of a conventional fuel injecting hole. The slit has such a shape that fuel injected into a combustion chamber cannot interfere with the combustion chamber as little as possible. Consequently, a fuel spray 3 through the slit-like injecting hole becomes flat and thin, and it can be brought into excellent contact with air so as to realize lean mixing, thus reducing generation of NOx.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection valve applied to a diesel engine.

[0002]

2. Description of the Related Art In a conventional fuel injection valve of this type, as shown in FIGS. 4 to 6, an injection hole 2 formed in a nozzle tip 1 is a round injection hole and a plurality of injection holes are arranged in combination. Was.

[0003]

However, in the combination of round nozzle holes, the fuel spray 3 from the nozzle holes spreads in a conical shape as shown in FIG. 4, and the outer peripheral side is well mixed with air, but the air is present in the center part. generation of the NO _x for is less rich Do state number becomes region many possible. The present invention was developed to address such a problem, and an object of the present invention is to make a fuel spray into a flat shape that is well mixed with air.

[0004]

The structure of the present invention for achieving the above object will be described with reference to FIGS. 1 to 3 corresponding to the embodiments of the present invention. In the present invention, a fuel injection hole 2 is formed in a nozzle tip 1. In the fuel injection valve of the installed diesel engine, the fuel injection hole 2 is formed as one slit-shaped injection hole.

[0005]

According to the present invention, by the above means, the fuel spray from the fuel injection hole becomes a flat and thin spray, and all the sprayed fuel particles are always in a position where they easily come into contact with the air, so that the temperature of the fuel is low. Since combustion starts in this state, the amount of NO _x generated also decreases.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. 1 denotes a nozzle tip, 2 denotes a fuel injection hole, and the fuel injection hole 2 has a flow rate characteristic (flow rate coefficient × injection hole). area)
However, it is formed in one slit-shaped injection hole which is the same as the conventional fuel injection hole, and the shape of the slit is such that the fuel injected into the combustion chamber does not interfere with the combustion chamber as much as possible, and the best combustion state is obtained. And

Thus, the fuel spray 3 from the slit-shaped injection hole becomes a flat and thin spray as shown in FIG. 1, and that portion can also come into good contact with air to achieve lean mixing, thereby generating NO _x . Reduce.

[0008]

As described above, according to the present invention, since the fuel injection hole formed in the nozzle tip is formed as one slit-shaped injection hole, the fuel spray from the fuel injection hole does not occur. It becomes flat and has a small thickness, so that it is in good contact with air, the combustion speed is increased, and the amount of NO _x generated can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a plan view of a slit-shaped injection hole.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a perspective view showing a conventional example.

FIG. 5 is a plan view of a round injection hole.

6 is a sectional view taken along line BB of FIG.

[Explanation of symbols]

 1 Nozzle tip 2 Fuel injection hole

Claims (1)

[Claims] 1. A fuel injection valve for a diesel engine having a fuel injection hole formed in a nozzle tip, wherein the fuel injection hole is formed as one slit-shaped injection hole.