JPH02286872A - Fuel injection valve - Google Patents

Abstract

PURPOSE:To turn fuel into very fine particles by furnishing a mixing chamber for mixing of the fuel and air leading to a fuel passage and an air passage, and providing a ring-shaped jet which leads to this mixing chamber and is so formed as becoming narrower toward the tip. CONSTITUTION:An air atomizing type fuel injection valve 1 is equipped with a mixing chamber 22 for mixing of the fuel and air leading to a fuel passage 24 and an air passage 26. Therein a ring-shaped jet 23 is provided, which leads to this mixing chamber 22 and is formed as narrower toward the tip of the injection valve 1. In this mixing chamber 22 of fuel injection valve 1, the air is mixed with the fuel, which is turned into particulates. The mixture stream is jetted out of the jet 23 and decompressed rapidly, and the fuel is further turned into very fine particles to then be fed to the engine. Thus the performance of the engine can be further enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a fuel injection valve with improved fuel atomization performance.

2. Description of the Related Art An example of a conventional fuel injection valve is the one shown in FIG. 3 (see Utility Model Application No. 171978/1984).

This fuel injection valve is called an air spray type fuel injection valve, and an air passage 3 is opened near the injection port 2 of the fuel injection valve I, and an air pump (see FIG. 4) The air that is sent from the air pipe 4 and introduced into the air chamber 5 is blown out from the air passage 3, collides with the fuel, and becomes atomized.

FIG. 4 shows a conventional fuel injection valve control system in which the above-mentioned air spray type fuel injection valve (hereinafter simply referred to as a fuel injection valve) is used. A fuel injection valve 1 is installed in an intake pipe 7 of an engine 6.

A fuel injection valve control system is constituted by a fuel pipe 8 that supplies fuel to the fuel injection valve l, an air pump 9 and air pipe 4 that supplies air, and a Brennyer regulator lO that keeps the fuel pressure constant. .

In the figure, 11 is a water temperature sensor, 12 is a control unit that controls the drive of the air pump 9 based on the output of the water temperature sensor 11, and 13 is a crank angle sensor.
[4 is a turbocharger.

Problems to be Solved by the Invention However, in such a conventional fuel injection valve I, since the air flow and the fuel flow collide to convert the fuel into mFQ, the atomization performance is not sufficient. However, there was a problem in that it was not possible to obtain fuel with an extremely small particle size, which is necessary when starting a methanol engine at a low temperature.

The present invention has been made in view of these conventional problems, and its purpose is to provide a fuel injection valve that can obtain fuel with an extremely small particle size. .

Means for Solving the Problems Therefore, the present invention provides an air atomizing fuel injection valve including a mixing chamber for mixing fuel and air that communicates with a fuel passage and an air passage provided in the valve; The fuel injection valve is characterized by having an annular nozzle opening that becomes narrower toward the tip of the communicating fuel injection valve.

Function The present fuel injection valve is for promoting atomization of fuel at the time of starting, and the cooling water temperature is set at a set value (for example, 60°C).
℃), the air pump operates and pressurized air is sent to the fuel injection valve.

Then, the air is mixed with fuel in the mixing chamber of the fuel injection valve, and the fuel is atomized.

Thereafter, the mixed flow is injected from an annular injection port formed narrowly toward the tip, and the pressure is rapidly reduced, and the fuel is further atomized to an extremely small particle size and supplied to the engine.

EXAMPLES Hereinafter, the present invention will be explained based on the drawings. FIG. 1 is a diagram showing an embodiment of the present invention.

First, the configuration will be explained. Fuel flow control valve 16 in body 15
However, the fuel is sealed and fixed by a gasket 17 and an O-ring 18.

Also, the fuel flow control valve 16. A cylindrical outer member 20 and a cylindrical inch member 2 fixed to the outer member 20 by press-fitting are located downstream of the spout portion I9! A mixing chamber 22 and an annular nozzle portion 23 are formed by these.

The mixing chamber 22 communicates with a fuel passage 24 and an air passage 26 that supplies swirling airflow from the air chamber 25 to the mixing chamber 22, and the nozzle portion 23 is formed to become narrower toward the tip. There is. Note that 27 is a fuel inlet and 28 is an air inlet.

In FIG. 2, a fuel injection valve I according to the present invention is applied.
An example of a fuel injection valve control system is shown.

A fuel injection valve 1 is installed in an intake pipe 7 of an engine 6. A fuel pipe 8 that supplies fuel to the fuel injection valve I is connected to an air pump 9 and air pipe 4 that supply air.

A pipe 30 is connected from the intake pipe 7 upstream of the throttle valve 29 to the air pipe 4 via a check valve 31, and a reference pressure pipe 32 of the pressure regulator IO is also connected to the air pipe 4 via the pipe 30. has been done.

Next, the operation will be explained with reference to FIG. The fuel sent to the fuel injection valve 1 is controlled by a fuel flow control valve 16,
The fuel is injected into the mixing chamber 22 through the fuel passage 24 .

On the other hand, the air is a water temperature sensor! When the water temperature is detected by (2) and is below a set value, for example, 60° C. or below, the air pump 9 is driven by a signal from the control unit 12, and the air is supplied to the fuel injection valve 1 through the air pipe 4 from the air supply 28. The supplied air is sent to the air chamber 25, passes through an air passage 26 that supplies a swirling air flow to the mixing chamber 22, and is ejected into the mixing chamber 22.

In the mixing chamber 22, the fuel flow and the air flow collide, and the fuel is atomized and mixed with the air.

Thereafter, the mixed flow of fuel and air is injected from the annular nozzle 23 that is narrower toward the tip. In the nozzle part 23, the pressure loss is maximum at the tip, and the mixed flow that has become a thin film is injected and the pressure is rapidly reduced, the air expands, and the fuel is atomized to an extremely small particle size.

When the cooling water temperature exceeds the set value, the air pump 9 is stopped. However, air is sent from the intake pipe 7, through the check valve 31, through the pipe 30, to the air pipe 4, and then supplied to the fuel injection valve 1 from the air supply 2B.

The supplied air passes through the air chamber 25 and the air passage 26, is introduced into the mixing chamber 22, and mixes with the fuel, as in the case of low temperature. Thereafter, the mixed flow is injected from the injection part 23, and the fuel is atomized into extremely small particle sizes.

At this time, since the tip of the nozzle part 23 is formed narrowly,
Since the film thickness of the mixed flow is thin, atomized fuel with small particle size can be obtained with a small amount of air.

In addition, it is connected to the reference pressure pipe 32 of the pressure regulator 10 or the air pipe 4, and the air pressure of the air pipe 4, in other words, the air chamber 25 of the fuel injection valve 1 and the fuel injection valve 1
Since the difference between the fuel pressure and the fuel supplied to the engine 6 is controlled to be constant, an appropriate fuel pressure corresponding to each operating state of the engine 6 is always ensured, and the air pump stops when the cooling water temperature exceeds the set value. Accurate fuel spill control is possible even when

Furthermore, even when the air pump 9 is stopped, air is still being supplied to the fuel injection valve I, so oil mist does not adhere to the tip of the fuel injection valve I due to blowback from the engine combustion chamber.

Effects of the Invention Since the present invention is constructed as described above, it is possible to obtain fuel with an extremely small particle size, thereby further improving engine performance.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of the present invention, Fig. 2 is an overall configuration diagram showing an example of a control system to which the fuel injection valve according to the invention is applied, and Fig. 3 shows a conventional fuel injection valve. The sectional view and FIG. 4 are overall configuration diagrams showing a conventional fuel injection valve control system. ! ...Fuel injection valve, 4...Air piping, 7...Intake pipe, 9...Air pump, 10...Pressure regulator, 11...Water temperature sensor 12...Control unit, I6... Fuel flow control valve, 22... Mixing chamber, 23... Nozzle part, 24... Fuel passage, 25...
...Air chamber, 26...Air passage, 30...Piping, 31
...Check valve, 32...Reference pressure piping. Fig. 1 1...Fuel injection valve 16...Fuel flow control valve 22...Mixing chamber 23...Nozzle port 24/Fuel passage 25 Air chamber 26/Air passage

Claims (1)

[Claims] (1) In an air spray type fuel injection valve, there is a mixing chamber for mixing fuel and air that communicates with a fuel passage and an air passage provided in the valve, and a mixing chamber that communicates with the mixing chamber and is formed to become narrower toward the tip. A fuel injection valve characterized by having an annular injection port.