JPS633427Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a fuel injection device for an internal combustion engine, particularly a fuel injection nozzle (injector) disposed in an intake passage.
Regarding.

In a general fuel injection device, a predetermined amount of fuel is injected from a fuel injection nozzle (injector) into an intake passage of the engine, depending on the intake air amount of the engine and other operating conditions of the engine.

Fuel injected into the intake passage must be atomized and sent to the combustion chamber, but the average particle size of fuel discharged from conventional injectors is 800 μm.
The atomization characteristics are poor because the amount of water is extremely large. Poor atomization characteristics adversely affect exhaust gas control and fuel efficiency, especially when the engine is operated at low temperatures. In other words, when the engine is operating at low temperatures, fuel tends to adhere to the cold intake passage walls and intake valves and become liquid, causing a delay in supply to the combustion chamber.In anticipation of this supply delay, the amount of fuel injection is increased. However, this worsens the exhaust gas components,
Moreover, it worsens fuel efficiency.

In order to solve this problem, measures have been taken such as adjusting the fuel injection angle and improving the roughness of the wall near the intake port, but this is not effective because the injection inertia is large when the fuel particle size is large. This has not led to significant improvements.

The present invention was developed based on these circumstances, and its purpose is to create a uniform flow of fuel by applying a swirling flow to the fuel discharged from the fuel discharge port of the injector using gas introduced from the outside. It is an object of the present invention to provide a fuel injection device for an internal combustion engine that achieves atomization and improves atomization characteristics, thereby making it possible to purify exhaust gas and improve fuel efficiency.

That is, in the present invention, a gas supply socket is attached to the tip of a fuel injection nozzle, and the gas introduced through the gas introduction hole formed in the socket is passed through the injection hole formed at the tip of the socket, together with the fuel discharged from the nozzle. In the fuel injection device, the tip of the gas supply socket is brought into contact with the tip surface of the nozzle, and the tip of the gas supply socket is provided with a gas supply socket on the tip surface of the nozzle in a direction non-normal to the fuel discharge port opened in the nozzle. A guide groove is formed, and the injection hole opened at the tip of the gas supply socket is formed larger than a fuel discharge port opened at the tip surface of the nozzle, and the gas flow is introduced into the tip of the nozzle by the guide groove. The present invention is characterized in that a swirling flow is generated, and the swirling flow atomizes the fuel, which is then ejected from the injection hole.

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

FIG. 1 is a schematic diagram showing the entire electronic fuel injection system, in which 1 is a cylinder, 2 is a piston 3
is a combustion chamber, 4 is an intake valve, 5 is an exhaust valve, 6 is an intake manifold, 7 is a throttle valve, 8 is an air flow meter, 9 is an air cleaner, 10 is an exhaust passage, 11
12 is a fuel tank, 12 is a fuel pump, 13 is a fuel filter, 14 is a pressure regulator, 15 is a distributor, and 16 is an electronic control device consisting of an electronic circuit.

Air taken in through the air cleaner 9 passes through the air flow meter 8 and the throttle valve 7 to the intake manifold 6, where it is distributed to each cylinder and introduced into the combustion chamber 3 when the intake valve 4 is opened. Ru. Since the intake air amount is detected by the air flow meter 8, this intake air amount signal is sent to the electronic control unit 16.
can be conveyed to.

The fuel in the fuel tank 11 is pumped through a fuel pump 12,
The fuel is fed through a fuel filter 13 to a fuel injection nozzle (injector) 20 installed in the intake passage, and the injector 20 is connected to an electronic control unit 16.
Only when a command is given from the engine, the discharge port opens and fuel is supplied toward the intake passage. The electronic control unit 16 issues a command signal to operate the injector 20 to each cylinder in response to the timing of the ignition signal distribution action in the distributor 15, or simultaneously operates the injector to all cylinders in response to the timing of the ignition signal of the cylinder. It issues a command signal and controls the opening time of the discharge port in the injector 20 according to other operating conditions.

The injector 20 is constructed as shown in FIG. 2 and below. That is, 21 indicates a fuel injection nozzle body, and a fuel discharge port 22 that is opened in the axial direction is opened at the tip surface of this nozzle body 21. Although not shown, a discharge valve that is electromagnetically operated based on a command from the electronic control unit 16 is accommodated in the main body 21, and the discharge port 22 is opened and closed by this discharge valve.

A gas supply socket 23 is attached to the tip of the nozzle body 21. The socket 23 has a plurality of gas introduction holes 24 on the peripheral wall, and
A gas introduction path 25 is formed between the peripheral wall and the peripheral surface of the nozzle body 21. Further, a closing wall 26 at one end of the socket 23 is adapted to come into contact with the distal end surface of the nozzle body 21. The outlet 22 of the nozzle body 21 is located in the closing wall of the socket 23.
An injection hole 27 is formed opposite to the discharge port 22 and having a larger opening area than the discharge port 22 to eject fuel and gas together. A swirling chamber 28 having a diameter larger than the diameter of the injection hole 27 is formed inside the injection hole 27 .

However, the tip surface of the nozzle body 21 has a fourth
Guide grooves 29 as shown in Figure A are formed. The guide grooves 29 provide a swirling flow to the gas flow flowing into the swirling chamber 28 from the gas introduction path 25, and are formed, for example, along the tangential direction to the discharge port 22. Note that the guide grooves 29 are not limited to the tangential direction, but may be formed, for example, in a spiral shape, and in short, a swirling flow can be generated in any direction other than the normal direction (radial direction).

The gas introduction holes 24 formed in the peripheral wall of the socket 23 communicate with an intake passage upstream of the throttle valve 7 via an air passage 30 shown in FIG. An air generator 31 is provided in the middle of this air passage 30, and this air generator 31 keeps the pressure of the air passing through the air passage 30 constant with respect to the manifold pressure detected by the pressure detection port 32 opened to the intake manifold 6. I'm learning to keep it that way.

Note that an air pressure detection port 33 is opened in the middle of the air passage 30, and this port 33 is connected to the pressure regulator 14 described above.
The fuel pressure is controlled according to the pressure in the air passage 30.

The operation of the embodiment with such a configuration will be explained. When a discharge valve (not shown) in the injector 20 is operated based on a command from the electronic control device 16, fuel is discharged from the fuel discharge port 21. At this time, the air being supplied into the gas introduction path 25 through the gas introduction holes 24 of the socket 23 reaches the swirling chamber 28 via the guide grooves 29 as the guide grooves 29 are moved along the non-normal direction. A swirling flow is generated based on the fact that the Therefore, a swirling flow of air is generated in the swirling chamber 28. The fuel discharged from the discharge port 21 is swirled within the swirling chamber 28 by riding on the swirling flow of air. Therefore, the particles of the fuel discharged from the discharge port 21 are atomized while being swirled within the swirling chamber 28, and when injected from the injection hole 22, the particles are also atomized because the fuel is swirled.

Therefore, the atomization characteristics of the fuel in the intake passage are improved, and the injection inertia of the fuel is also reduced, so the proportion of fuel adhering to the walls of the intake passage and the intake valve 4 is reduced, which improves exhaust gas purification, especially when the engine is operated at low temperatures. , which will contribute to improving fuel efficiency.

Moreover, in the case of the above embodiment, since the guide grooves 29 for giving a swirling flow to the air were formed only on the tip surface of the nozzle body 21, this surface was
It has the advantage that it can be manufactured at low cost because it is easy to process and mold.

In the above embodiment, the air measured by the air flow meter 8 is used as the gas introduced into the socket 23, but the present invention is not limited to this, and the exhaust gas in the exhaust passage 10 is introduced into the socket through the exhaust gas recirculation valve. In this case, it is particularly effective to purify NOX in the exhaust gas components.

As detailed above, the present invention converts the gas introduced into the socket into a swirling flow through the guide groove formed on the nozzle tip surface, and the fuel discharged from the nozzle outlet is swirled by this swirling flow. Since the fuel is atomized and injected, the atomization performance of the fuel is improved, which contributes to purifying exhaust gas and improving fuel efficiency, especially during low-temperature operation of the engine. Moreover, in order to give a swirling flow to the gas, the present invention makes the tip of the gas supply socket contact the tip surface of the nozzle, and also attaches the tip of the nozzle to the tip surface of the nozzle in a direction that is not normal to the fuel discharge port opened in the nozzle. Since the guide groove is formed, a large space is not required inside the gas supply socket, and the gas supply socket can be made compact.The guide groove is also formed on the tip surface of the nozzle, making it easy to mold the guide groove. and
In addition, the fuel mixture that has been atomized by the swirling flow generated by this guide groove is injected from the injection hole with a large diameter, so it is injected in a strong swirling flow, which causes a problem with the intake air. It has advantages such as extremely good mixing.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic configuration diagram showing a system of an electronic fuel injection device;
Figure 2 is a side view of the injector, Figure 3 is an enlarged sectional view of the middle part of Figure 2, Figure 4A is a front view of the nozzle body, and Figure 4B is a cross section taken along line B-B in Figure 4A. FIG. 5 is a sectional view of the socket. 20...Fuel injection nozzle (injector), 2
DESCRIPTION OF SYMBOLS 1... Nozzle body, 22... Discharge port, 23... Socket, 24... Gas introduction hole, 25... Gas introduction path, 27... Injection hole, 28...... Turning chamber, 29...
...Guide groove.

Claims (1)

[Scope of utility model registration request] A gas supply socket is attached to the tip of the fuel injection nozzle, and the gas introduced through the gas introduction hole formed in the socket is injected from the injection hole opened at the tip of the socket together with the fuel discharged from the nozzle. In the fuel injection device, the tip of the gas supply socket is brought into contact with the tip surface of the nozzle, and a guide groove is formed in the tip surface of the nozzle in a direction non-normal to the fuel discharge port opened in the nozzle. , and the injection hole opened at the tip of the gas supply socket is formed larger than the fuel discharge port opened at the tip surface of the nozzle, and the guide groove generates a swirling flow in the gas flow introduced to the tip of the nozzle. A fuel injection device for an internal combustion engine, characterized in that the swirling flow is ejected from the injection hole.