JPH04314962A - Fuel feeding device for internal combustion engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply system for an internal combustion engine, which has a plurality of intake valves for each cylinder and injects fuel from a fuel injection valve provided in an intake passage for each cylinder.

0002

2. Description of the Related Art Conventional fuel supply systems for internal combustion engines include those shown in FIGS. 11 and 12, for example. This has two intake valves 2, 2 in the combustion chamber 1 of each cylinder,
Fuel is injected and supplied in two directions (towards each intake valve) from a fuel injection valve 4 provided at a collection point of branched intake ports 3 for each cylinder.

In this device, the injected fuel (fuel spray) adheres to the intake port inner wall 3a or the intake valve head portion 2a, creating a wall flow. This wall flow causes a delay in fuel transport, and if fuel is supplied at the stoichiometric air-fuel ratio, the actual air-fuel ratio becomes lean during transient operation, resulting in unstable combustion and reduced drivability. The problem arises. For this reason,
When the engine is cold, the engine is operated with a rich mixture, with emphasis on drivability. However, if you do this, excess fuel will become unburned HC.
Not only is it emitted as a cause of air pollution, but
There is also the problem that fuel efficiency deteriorates.

Therefore, in order to prevent the wall flow, as shown in FIG. 13, an extension part 5a is provided at the tip of the fuel injection valve 5 to extend close to the intake valve 6, so that fuel injection is performed while the intake valve 6 is open. There is a device in which the injected fuel is made to flow directly into the combustion chamber 8 from the intake valve opening 7 (Japanese Patent Laid-Open No. 63-10
6357, Utility Model Application Publication No. 1-118159, etc.). In addition, in FIG. 13, 9 is an assist air passage.

[0005]

[Problem to be solved by the invention] However, FIG.
If fuel flows directly into the combustion chamber using a fuel injection valve like the one shown in Figure 2, the fuel will not adhere to the inner wall of the intake port, and the delay in fuel transport within the intake port will hardly be a problem. The fuel spray is so powerful that it hits the cylinder wall of the combustion chamber, where it tends to form a wall flow. For this reason, the actual mixture ratio in the combustion chamber becomes thinner,
This may reduce drivability, or because the mixture is locally rich, it may remain as unburned HC or be emitted as soot (carbon).

SUMMARY OF THE INVENTION In view of these conventional problems, it is an object of the present invention to prevent fuel injected into a combustion chamber from forming a wall flow on the cylinder wall of the combustion chamber.

[0007]

[Means for Solving the Problems] Therefore, the present invention provides a fuel supply system for an internal combustion engine which has a plurality of intake valves in each cylinder and injects fuel from a fuel injection valve provided in an intake passage for each cylinder. In the device, a fuel guide path with a plurality of branches at the tip side is provided in series with the tip of the fuel injection valve, and the tip of each branch part of the guide path is located near each intake valve umbrella, and The injected fuel flows directly into the combustion chamber from each intake valve opening and is directed so as to collide with each other near the center of the combustion chamber.

In this case, the collision part of the injected fuel in the combustion chamber can be located near the spark plug. Furthermore, the ignition plug is provided with a cap-shaped plasma chamber that covers the ignition electrode portion and has a plurality of flame spouts,
A part of the flame outlet of the plasma chamber can be opened in the directional direction of the tip of the branch part of the guide path to serve as a fuel inlet.

[0009]

[Operation] In the above configuration, the injected fuel is caused to directly flow into the combustion chamber from each intake valve opening from the tip of the branching part of the fuel guide path extending from the tip of the fuel injection valve, so that the inner wall of the intake port and the intake air While wall flow is prevented at the valve head portion, wall flow at the cylinder wall of the combustion chamber is also prevented by causing the injected fuel to collide with each other near the center of the combustion chamber.

[0010] Furthermore, if the collision part of the injected fuel in the combustion chamber is located near the spark plug, ignition performance and combustion performance can also be improved. Furthermore, if a part of the flame outlet of the ignition plug with a plasma chamber is opened in the directional direction of the tip of the branch part of the guide path and used as a fuel inlet, the ignition performance and combustion performance of the ignition plug with a plasma chamber can be further improved. can.

[0011]

[Examples] Examples of the present invention will be described below. 1 and 2 show one embodiment of the present invention. Two intake valves 2, 2 are provided in the combustion chamber 1 of each cylinder, and a fuel injection valve 4 is provided at a gathering point of branched intake ports 3 for each cylinder.

At the tip of the fuel injection valve 4, a fuel conduit 10, which is branched into two on the tip side, is attached as a fuel guide path. This fuel conduit 10 has an attachment part 11 to the tip of the fuel injection valve 4, and a V-shape (or Y-shape) from the attachment part 11.
Branch portions 12, 12 that branch into a shape, and the branch portions 12, 12
It consists of nozzle portions 13, 13 provided at the tips facing inward, respectively.

[0013] Here, the nozzle portions 13, 13 are connected to each intake valve 2.
, 2 near the umbrella portions 2a, 2a, and inside the stem portions 2b, 2b (on the central side of the combustion chamber), respectively. Further, the injection ports 13, 13 are arranged such that the injected fuel (fuel spray) directly flows into the combustion chamber 1 from each intake valve opening 14 when the intake valves 2, 2 are opened, and Department, specifically,
They are oriented so that they collide with each other at the center plane 15 of the combustion chamber (the plane of symmetry between the two intake valves 2, 2). In addition, 20 is a spark plug.

Next, the operation will be explained. The fuel spray is caused to directly flow into the combustion chamber 1 through the intake valve openings 14 from the nozzle ports 13 and 13 at the tips of the branch portions 12 and 12 of the fuel conduit 10 extending from the tip of the fuel injection valve 4, so that the intake port It is possible to prevent wall flow from occurring on the inner wall 3a and the intake valve head portion 2a. In addition, the fuel spray ejected from the nozzle ports 13, 13 is
They collide with each other at the center plane 15 of the combustion chamber. As a result, the fuel spray becomes a jet flow toward the center of the combustion chamber and downward on the center surface 15 of the combustion chamber, and the fuel spray sufficiently spreads within the combustion chamber 1 without directly hitting the cylinder wall 16 of the combustion chamber.

[0015] Therefore, the spatial flotation rate of the fuel increases, and even in cold conditions, it burns stably at the stoichiometric air-fuel ratio, making it possible to operate with good fuel efficiency and less unburned HC without impairing drivability. . Other embodiments are shown in FIGS. 3 and 4. In this embodiment, the nozzle portions 13, 13 are directed near the spark plug 20 located at the center of the combustion chamber.

[0016] As a result, the fuel spray always comes stably near the spark plug 20, so there is no need to operate with excess fuel even during a cold start, improving fuel efficiency, reducing emissions of unburned HC, and improving startability. can achieve improvements in Further other embodiments are shown in FIGS. 5 to 7. In this embodiment, an ignition plug 20 having a plasma chamber 21 is used.
0 toward the plasma chamber 21, the nozzle portions 13, 13
It is designed to inject more fuel.

As shown in FIG. 7, the plasma chamber 21 covers the ignition electrode portion of the ignition plug 20 in a cap shape, and has a plurality of openings toward the side of the combustion chamber serving as flame jet ports that also serve as air-fuel mixture inlets. Although it has a horizontal hole 22,
Some of these are opened in the directional direction of the nozzle ports 13, 13 to serve as fuel inlets. As a result, the nozzle part 13,
13 directly flows in through some of the horizontal holes 22 and collides within the plasma chamber 21, forming a stable air-fuel mixture for ignition within the plasma chamber 21. However, by setting the position of the horizontal hole 22, etc., ensure that the fuel does not cover the discharge section.

The plasma chamber 21 is also formed with a downward hole 23 that opens toward the top surface of the piston, so that the flame within the chamber 21 generated by ignition is ejected to the lower side of the combustion chamber 1 as well. Still other embodiments are shown in FIGS. 8 to 10. In this embodiment, as a fuel guide path, a fuel gallery 31 is formed in the cylinder head 30 from its outer wall (the opening wall of the intake port 3) to the vicinity of the intake valves 2, 2 by machining or the like. By connecting the tip of the fuel injector 4 attached to one end of the fuel gallery 31 to one end of the fuel gallery 31 and connecting the fuel conduits 33, 33 to the side holes 32, 32 at the other end of the fuel gallery 31, the fuel guide path is branched. Inwardly facing nozzle ports 34, 34 are provided at the tips of the fuel conduit pipes 33, 33, which are branch parts, respectively.

Here, the nozzle portions 34, 34 are connected to each intake valve 2.
, 2 are located inside the stem portion (on the center side of the combustion chamber) near the umbrella portions of 2. Then, those injected fuels directly flow into the combustion chamber 1 when each intake valve 2 is opened, and
They are oriented so as to collide with each other near the ignition plug 20 in the center of the combustion chamber 1. Similar actions and effects can also be obtained in this manner.

[0020] The fuel injection valve 4 is one that supplies assist air for promoting atomization into the fuel, and the fuel mixed with the assist air to promote atomization is injected into the fuel conduit 10 or the like. When the fuel is guided into the combustion chamber 1 by the guide path, the spatial flotation rate of the fuel within the combustion chamber 1 is further improved, and combustion becomes more stable.

[0021]

As explained above, according to the present invention, fuel is not directly attached to either the inner wall of the intake port or the cylinder wall of the combustion chamber, and problems caused by delays in fuel transportation and wall flow inside the cylinder are reduced. There is no actual leanness of the air-fuel mixture due to engine cooling, and the engine can be operated stably at the stoichiometric air-fuel ratio when the engine is cold.
The effect is that unburned HC can be significantly reduced and fuel efficiency can also be improved.

[0022] Also, the collision part of the injected fuel is set near the ignition plug,
Furthermore, by providing the ignition plug with a plasma chamber inside the chamber, the ignition performance and combustion performance can be further improved.

[Brief explanation of drawings]

FIG. 1 A schematic plan view of an engine showing an embodiment of the present invention.

[Figure 2] Schematic front view of the same engine

[Figure 3] Schematic plan view of an engine showing another embodiment

[Figure 4
] Schematic front view of the same engine

[Figure 5] Schematic plan view of an engine showing yet another embodiment

[
Figure 6 Schematic front view of the same engine

[Figure 7] Enlarged plan view of the combustion chamber part of the same as above

[Figure 8]
Schematic plan view of an engine showing still another embodiment

[Figure 9]
Schematic front view of the same engine

[Figure 10] Enlarged plan view of the combustion chamber part of the same as above

[Figure 11
] Schematic plan view of an engine showing a conventional example

[Figure 12] Schematic front view of the same engine

[Fig. 13] Diagram of a fuel injection valve showing another conventional example

[Explanation of symbols]

1 Combustion chamber 2 Intake valve 3 Intake port 4 Fuel injection valve 10 Fuel conduit 12 Branch 13 Nozzle part 15 Combustion chamber center plane 20 Spark plug 21 Plasma chamber 30 Fuel gallery 33 Fuel conduit 34 Nozzle part

Claims (3)

[Claims] Claims: 1. A fuel supply device for an internal combustion engine which has a plurality of intake valves in each cylinder and injects fuel from a fuel injection valve provided in an intake passage for each cylinder, wherein a fuel injection valve is provided at a tip of the fuel injection valve. A fuel guide path with a plurality of branches at the tip side is provided in series, and the tips of each branch part of the guide path are located near each intake valve umbrella, and the injected fuel is directly transmitted from each intake valve opening. 1. A fuel supply device for an internal combustion engine, characterized in that the fuels flow into a combustion chamber and are oriented so as to collide with each other near the center of the combustion chamber. 2. The fuel supply system for an internal combustion engine according to claim 1, wherein the collision portion of the injected fuel in the combustion chamber is located near the spark plug. 3. The ignition plug includes a cap-shaped plasma chamber that covers the ignition electrode portion and has a plurality of flame outlets, and a part of the flame outlets of the plasma chamber is directed in the directional direction of the tip of the branching part of the guide path. 3. The fuel supply system for an internal combustion engine according to claim 2, wherein the fuel inlet is opened at the opening.