Internal-combustion engines – Combustion chamber means having fuel injection only – Combustible mixture stratification means
Reexamination Certificate
2001-05-08
2003-06-17
Miller, Carl S. (Department: 3747)
Internal-combustion engines
Combustion chamber means having fuel injection only
Combustible mixture stratification means
C123S305000, C123S041310, C239S533120, C239S132000
Reexamination Certificate
active
06578544
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electromagnetic fuel injection valve, and more particularly to an electromagnetic fuel injection valve for in-cylinder direct fuel injection in a system, which directly injects gasoline and other such fuels into a combustion chamber.
2. Description of the Related Art
As for the spray configuration in a conventional electromagnetic fuel injection valve for in-cylinder direct fuel injection, there is a cone shaped configuration that makes use of the swirling flow of a fuel, but this configuration is limited when it comes to enhancing fuel atomization and the state of an air/fuel mixture.
Another problem is that this configuration makes it difficult to suppress the formation of carbon deposits accompanying the combustion of a fuel.
An outline of the problem of suppressing the formation of carbon deposits will be given based on FIG.
7
and FIG.
8
.
FIG. 7
is a simplified side view of the principal portion of the nozzle body
2
part of an ordinary electronic fuel injection valve
1
, and fuel is injected toward a combustion chamber
4
as a cone-shaped spray
5
from an injection orifice
3
formed in the center tip portion of the nozzle body
2
.
FIG. 8
is a bottom view, as seen from the combustion chamber
4
side, of the bottom surface
6
of the combustion chamber side of a nozzle body
2
, and carbon deposits C are formed around the injection orifice
3
of the center portion thereof. As the condition under which carbon deposits C are formed, there is a fixed formation temperature range, and in order to either suppress or reduce carbon deposits C, there is the method of either applying heat in excess of the upper limit temperature of the temperature thereof, or cooling to below the lower limit temperature.
As a measure for suppressing carbon deposits C, when trying, for example, to lower the temperature of the nozzle body
2
, the problem is that, for a cone-shaped spray
5
, the only hope is a cooling action resulting from the flow of a fuel through the injection orifice
3
from inside the nozzle body
2
, and the flow of a fuel at the injection orifice
3
part, but the actual cooling effect is not sufficient.
Over time, the carbon deposits C thereof accumulate around the injection orifice
3
, and there are even cases in which carbon deposits C also penetrate into the upstream side inside the injection orifice
3
, causing changes in the quantity of fuel injected, the shape of the spray, or the injection direction. In any event, this is not a desirable phenomenon for an electronic fuel injection valve
1
, and either avoiding or suppressing the phenomenon thereof is an essential task.
As constitutions for reducing the temperature of the nozzle body
2
, there are, for example, Japanese Utility Model Application Laid-open No. S56-94856, Japanese Utility Model Publication No. S62-31613, and Japanese Patent Laid-open No. H9-264232.
Further, a cone-shaped spray
5
is limited when it comes to enhancing fuel atomization and the state of an air/fuel mixture.
Accordingly, as in Japanese Utility Model Application Laid-open No. S59-172276, Japanese Utility Model Laid-open No. H5-83366, Japanese Patent Laid-open No. H8-144762, and Japanese Patent Laid-open No. H8-177499, for example, there are constitutions in which a high-pressure fuel is injected by either changing the spray shape, or as a flat-shaped spray (fan spray), by causing fuel jets to impinge on one another after being injected from at the least a pair of injection orifices.
In the case of the fan-spray fuel injection valves thereof as well, the problem is that it is necessary to provide separately a cooling structure for appropriately and adequately cooling the nozzle body
2
and the injection orifice
3
parts, and it is difficult to avoid the formation of carbon deposits C with a simple constitution.
SUMMARY OF THE INVENTION
With the foregoing problems in view, it is an object of the present invention to provide an electromagnetic fuel injection valve, which is capable of reducing emissions by promoting combustion via the atomization of injected fuel, and, in addition, is capable of reducing emissions by lowering fuel consumption by promoting the mixing of injected fuel with air.
Further, an object of the present invention is to provide an electromagnetic fuel injection valve capable of suppressing carbon deposits that form and adhere to the bottom surface of the combustion chamber side of a nozzle body and an injection orifice.
Further, an object of the present invention is to provide an electromagnetic fuel injection valve constituted such that formed carbon deposits are washed away by injected fuel.
Further, an object of the present invention is to provide an electromagnetic fuel injection valve capable of suppressing the formation of carbon deposits via a simple constitution.
Further, an object of the present invention is to provide an electromagnetic fuel injection valve comprising a constitution for simple and efficient carbon deposit suppression, such that a nozzle body can be cooled, and, in addition, washed off by a fuel jet itself, which is injected from an injection orifice.
In other words, the present invention is an electromagnetic fuel injection valve for injecting a high-pressure fuel as a flat-shaped spray (fan spray) by causing fuel jets to impinge upon one another after being injected from at the least a pair of injection orifices, and is one, which aims at causing jets to impinge by controlling the pressure and direction of the jets so that the jets also go toward the direction of the bottom surface of the combustion chamber side of the nozzle body in the direction opposite (upstream side) of a normal injection direction, which goes toward the direction of the combustion chamber, and is an electromagnetic fuel injection valve, having an electromagnetic coil; a nozzle body, which forms at the least a pair of injection orifices constituted such that each jet resulting from injected fuel impinges upon the other inside a combustion chamber; and a needle valve, which sits on the seat portion of this nozzle body, and, in addition, is capable of opening and closing the above-mentioned injection orifices by exciting the above-mentioned electromagnetic coil, and being constituted such that the above-mentioned jets resulting from fuel injected from the above-mentioned injection orifices are made to impinge upon one another, and are injected as a flat-shaped spray, this electromagnetic fuel injection valve being characterized in that the above-mentioned flat-shaped spray is diffused in the above-mentioned direction of the combustion chamber, and, in addition, in the direction of the above-mentioned nozzle body of the upstream side.
The above-mentioned spray, which diffuses in the above-mentioned nozzle body direction, can be constituted so as to wash off the proximity of the above-mentioned injection orifice.
The above-mentioned spray, which diffuses in the above-mentioned nozzle body direction, can have a cooling and washing area, which encloses the above-mentioned injection orifice on the combustion chamber-facing surface of the above-mentioned nozzle body.
It is possible to adjust the degree of diffusion toward the upstream side of the above-mentioned spray by selecting the degree of inclination of each of the above-mentioned injection orifices relative to the axis of the above-mentioned needle valve.
It is possible to adjust the degree of diffusion toward the upstream side of the above-mentioned spray by selecting the injection orifice pitch between the axis of each of the above-mentioned injection orifices.
In an electromagnetic fuel injection valve according to the present invention, because of being constituted such that a constituent for diffusing to the upstream side is generated from the flat-shaped spray formed by the jets impinging upon one another, and the upstream side diffusion constituent thereof is made to impinge on the bottom surface of the combustion chamber side of the nozzle body and wash off a
Bosch Automotive Systems Corporation
Miller Carl S.
Ostrolenk Faber Gerb & Soffen, LLP
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