JPH0225031B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection valve that injects fuel into an intake pipe of a multi-cylinder internal combustion engine to facilitate engine startup.

Generally, in cold weather when the cooling water temperature is below a set value, the atomization characteristics of fuel are not good, so a starting fuel injection valve is used to inject fuel into the intake pipe to enrich the mixture.

Only one valve of this type is attached to a collecting pipe section on the upstream side of an intake pipe connected to each cylinder of the engine in order to distribute and distribute an increased amount of fuel to each cylinder of a multi-cylinder internal combustion engine. However, the intake pipes of a multi-cylinder internal combustion engine are arranged in parallel so as to be substantially coplanar with each other, whereas the starting fuel injection valve is installed in the center of the collecting pipe section. In addition, since the injection holes in conventional valves are perfectly circular, the fuel injected from the injection holes generates a conical spray pattern. For this reason, a large amount of fuel is supplied to the intake pipes close to the injection valves, but less fuel is supplied to the intake pipes outside in the parallel direction.
There was a problem where the air-fuel mixture was not distributed evenly into the cylinders. In addition, the fuel directly hits the central wall of the collecting pipe and becomes a wall flow, and the fuel that becomes the wall flow has poor atomization, and a large lag occurs between the injection timing and the timing when the fuel reaches each cylinder. In the end, the air-fuel ratio was different for each cylinder, resulting in uneven startability between the cylinders.

The present invention was made in view of the above circumstances, and provides a fuel injection valve for starting an internal combustion engine, which equalizes fuel distribution to each cylinder and reduces wall flow caused by direct contact of fuel with the wall of the collecting pipe. The purpose is to provide

That is, the present invention is characterized in that the injection hole provided in the fuel injection valve is formed into an elongated shape along the parallel direction of each intake pipe so as to produce a long spray pattern along the parallel direction of each intake pipe. .

According to such a configuration, the longitudinal direction of the flat spray pattern is directed toward the farthest intake pipe among the intake pipes arranged in parallel with each other, so that the fuel distribution can be equalized, and the injection Since it is only necessary to devise the shape of the hole, the above object can be achieved with a simple structure.

An embodiment of the present invention will be described below based on the drawings.

1 and 2 show a starting fuel injection valve 30, in which 1 is a plunger, and a valve 2, which moves integrally with the plunger 1, is attached to one end of the plunger.
The plunger 1 is made of a magnetic material, and the valve 2 is made of an elastic material such as rubber. The valve 2 has a spring 4 attached to the seat surface 3a of the connector 3 that constitutes the fuel supply passage.
It is pressed by and comes into close contact. Reference numeral 5 denotes a terminal, which serves as a terminal for supplying electricity to the electromagnetic coil 6. The coil 6 is wound around a non-magnetic bobbin 7, and the plunger 1 is moved inside the non-magnetic bobbin 7. Note that the coil 6 is covered with a cover 8. A filter 9 is housed inside the connector 3 via a holding frame 10. Reference numeral 11 denotes a core, which is formed to penetrate a fuel passage 12 through which fuel passes along the axial direction. A plate 13 and a nozzle 14 are attached to the tip of the core 11 by caulking or other means. A space surrounded by plate 13 and nozzle 14 forms a swirl chamber 15 . The plate 13 has a fuel inlet hole 1 on its side wall.
6 is formed, and one end of this introduction hole 16 communicates with the fuel passage 12 (not shown), and the other end opens into the swirl chamber 15 in the connection direction. The nozzle 14 has a fuel injection hole 17 opened downward in the lower end wall shown in the figure.
The injection hole 17 has an elliptical shape, as shown in FIG. 2, for example. Note that 18 and 19 are O-rings.

In FIG. 3, reference numeral 20 indicates a multi-cylinder internal combustion engine in which cylinders are arranged in series, and reference numerals 21, . . . indicate intake pipes led out from each cylinder. Each intake pipe 21... is the engine 20
are arranged side by side along the axial direction, and the upstream sides of these intake pipes 21 are communicated with a collecting pipe section 22. An air purifier 23 is connected to the central portion of the collecting pipe section 22 . Each cylinder of the engine 20 is connected to a collecting pipe section 2.
Air taken in through the air purifier 23 is supplied from the center of the air purifier 23.

In the central part of the collecting pipe section 22,
A starting fuel injection valve 30 shown in the figure is installed. In this case, the injection hole 17 of the fuel injection valve 30 has an elliptical long axis direction (A-A line in FIG. 2) that is aligned with or parallel to the parallel direction of each intake pipe 21, that is, the axial direction of the engine 20. It is installed in such a position that

The operation of the above configuration will be explained.

When starting in cold weather when the cooling water temperature is below a set value, the electromagnetic coil 6 is energized through the terminal 5 at the same time as the starter is energized. Due to the electromagnetic attraction force of the coil 6, the plunger 1 is attracted toward the core 11 against the pressing force of the spring 4. As a result, the valve 2 is separated from the seat surface 3a, and the fuel introduced into the connector 3 while maintaining a constant pressure is transferred to the filter 9.
After being filtered by the seat surface 3a and the valve 2
It is introduced into the bobbin 7 through the gap between the bobbin 7 and the bobbin 7.
This fuel passes through the gap between the bobbin 7 and the plunger 1, passes through the fuel passage 12 of the core 11, and flows into the swirl chamber 15. In the swirl chamber 15, the inflow hole 16 is formed in the connection direction, so that a swirling flow is generated. The fuel swirled within the swirl chamber 15 is injected into the collecting pipe section 22 from the injection hole 17 provided in the nozzle 14.

In this case, since the injection hole 17 has an elliptical opening, the fuel injected from the injection hole 17 forms an elliptical shape as shown in FIG. 4, that is, a flat spray pattern P on a plane perpendicular to the injection direction. arise.
In this elliptical spray pattern P, since the major axis of the injection holes 17 is provided along the parallel direction of the intake pipes 21, the major axis of the spray pattern also follows the arrangement direction of the intake pipes 21. Therefore, not only the intake pipe 21 located near the fuel injection valve 30 but also the intake pipe 2 located away from the injection valve 30
Since fuel is sufficiently supplied to cylinders 1 and 1, uniform fuel distribution and supply to each cylinder is performed. In addition, the flat spray pattern reduces the direct application of fuel to the wall surface of the collecting pipe section facing in the short diameter direction, thereby reducing the occurrence of wall flow.

Note that the fuel injected into the collecting pipe section 22 is mixed with the air taken in from the air cleaner 23, and this mixture is of course distributed to each cylinder of the engine 20 via each intake pipe 21. .

In the above embodiment, the case where the injection hole 17 was opened in an elliptical shape was explained, but the present invention is not limited to this. may be a rectangular hole along the direction AA in FIG. In addition, a member that shields the spray so that the spray pattern does not spread in a direction perpendicular to the direction A-A in FIG. It is also possible to use these injection holes at the same time.

As described in detail above, the present invention causes the fuel injected from the injection holes to produce a flat spray pattern on a plane perpendicular to the injection direction, and the longitudinal direction of this flat spray pattern Since it follows the direction, it is possible to distribute fuel evenly to each intake pipe, and
Direct contact with the wall of the collecting pipe section is reduced, the wall flow is reduced, and variations in startability between cylinders are eliminated, allowing smooth and reliable starting.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, FIG. 1 is a sectional view of a starting fuel injection valve, and FIG.
FIG. 3 is a view taken along the line, FIG. 3 is a view showing the mounting state of the fuel injection valve, and FIG. 4 is a view showing the spray pattern. DESCRIPTION OF SYMBOLS 1... Plunger, 6... Coil, 11... Core, 12... Fuel passage, 15... Vortex chamber, 17...
...Injection hole, 20...Multi-cylinder internal combustion engine, 21...Intake pipe, 22...Collecting pipe section.

Claims (1)

[Scope of Claims] 1. It is installed in a collecting pipe section of intake pipes arranged in parallel to each cylinder of a multi-cylinder internal combustion engine, and operates a plunger by energizing an electromagnetic coil during a cold start, thereby discharging fuel. The fuel in the swirl chamber is led from the fuel passage provided in the core to the swirl chamber, and the fuel in the swirl chamber is injected from one injection hole opened in the swirl chamber toward the approximate center of the collecting pipe section to fuel each of the multi-cylinder internal combustion engines. In a starting fuel injection valve for an internal combustion engine that supplies distribution to cylinders, the injection hole is configured to inject the fuel in the swirl chamber from the injection hole in a flat spray pattern along the parallel direction of the intake pipes. A fuel injection valve for starting an internal combustion engine, characterized in that it is formed into an elongated shape along the parallel direction of intake pipes.