JPH0544470A - Fuel supplying device in four valve type internal combustion engine - Google Patents

Abstract

PURPOSE:To ignite and burn intake air fuel mixture surely and clean exhaust gas, in a four valve type internal combustion engine constructed by two intake valves and two exhaust valves provided for one combustion chamber. CONSTITUTION:The inside of a combustion chamber 5 is constructed by a first chamber 5a including one side intake port 6 and one side exhaust port 8, and a second chamber 5b including the other side intake port 7 and the other side exhaust port 9, with a spark plug 19, serving as a boundary between them, and a fuel injection valve 20 is provided on either one of the first chamber 5a or the second chamber 5b so as to injection-supply fuel during the last half period of compression stroke.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called four-valve type internal combustion engine in which two intake valves and two exhaust valves are provided for one combustion chamber having a spark plug substantially at the center thereof. The present invention relates to a fuel supply device.

[0002]

2. Description of the Related Art In a four-valve internal combustion engine of this type, one combustion chamber having an ignition plug is provided with two intake ports each having an intake valve and two exhaust ports each having an exhaust valve. On the other hand, the combustion chambers are arranged at mutually opposite parts, and the combustion chamber is a first chamber including one intake port and one exhaust port with the ignition means as a boundary, and a second chamber including another intake port and the other exhaust port. Constituting with a chamber is disclosed in Japanese Patent Publication No. 49-23848 and Japanese Utility Model Publication No. 57-2 as prior art.
2628, etc.

[0003]

The four-valve internal combustion engine according to this prior art is configured as described above, so that the intake air-fuel mixture sucked from the two intake ports has a longitudinal loop. Although it is configured to accelerate the ignition / combustion of the intake air-fuel mixture by imparting a uniform vortex, the air-fuel ratio is lean because the air-fuel mixture of the same air-fuel ratio is taken in from both the intake ports. If it is set, the ignition / combustibility of the intake air-fuel mixture will become unstable and not only the drivability will decrease, but also unburned components such as hydrocarbons in the exhaust gas will increase. When set to rich, ignition of intake air mixture
Although the combustibility can be improved, there is a problem that the combustion temperature becomes high and the amount of nitrogen oxides in the exhaust gas increases.

The present invention solves the above problems by utilizing the characteristics of the four-valve internal combustion engine described above to perform stratified intake of a lean air-fuel mixture and a rich air-fuel mixture. This is a technical issue.

[0005]

In order to achieve this technical object, the present invention is directed to one combustion chamber provided with ignition means such as a spark plug, two intake ports each provided with an intake valve, and exhaust gas each provided. The two exhaust ports provided with a valve are arranged at positions facing each other, and the combustion chamber has a first chamber including one intake port and one exhaust port with the ignition means as a boundary, and the other intake chamber. Second including a port and the other exhaust port
In a four-valve internal combustion engine configured with a chamber, one of the first chamber and the second chamber constituting the combustion chamber,
A fuel injection valve is provided to inject and supply fuel in the latter half of the compression stroke.

[0006]

[Operation] In one combustion chamber equipped with ignition means such as a spark plug,
Two intake ports each provided with an intake valve and two exhaust ports each provided with an exhaust valve are arranged at opposite positions, while the combustion chamber has one intake port with the ignition means as a boundary. In a four-valve internal combustion engine configured by a first chamber including one exhaust port and a second chamber including the other intake port and the other exhaust port, both intake air during the intake stroke due to the downward movement of the piston. By configuring the combustion chamber with the first chamber and the second chamber, it is possible to impart a longitudinal loop-like vortex flow toward the exhaust port to each of the intake air flowing into the combustion chamber from the port, and The intake air-fuel mixture of the two loop vortices is compressed while being mixed with each other in the compression stroke accompanying the upward movement of the piston.

Therefore, in the latter half of the compression stroke, the fuel is injected by the fuel injection valve into one of the first chamber and the second chamber constituting the combustion chamber to supply the first chamber. The air-fuel ratio of the intake air-fuel mixture in one of the first chamber and the second chamber becomes rich, while the air-fuel ratio of the intake air-fuel mixture in the other chamber becomes the air-fuel ratio of the intake air-fuel mixture in the one chamber. Since it becomes leaner than the fuel ratio, the air-fuel ratio of the intake air-fuel mixture in one of the first chamber and the second chamber that configures the combustion chamber is made rich, and the air-fuel ratio of the intake air-fuel mixture in the other chamber is made lean. You can
A stratified intake can be achieved.

[0008]

Therefore, according to the present invention, so-called stratified intake achieves reliable ignition / combustion of the intake air-fuel mixture and clean exhaust gas without complicating the shape and structure of the combustion chamber. Has the effect that can.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. 1 to 4 show the first embodiment. In this figure, reference numeral 1 is a cylinder block, and reference numeral 2 is
Each of the cylinder heads fastened to the upper surface of the cylinder block 1 is shown, a reciprocating piston 4 is inserted into the cylinder bore 3 of the cylinder block 1, and a combustion chamber 5 is provided on the lower surface of the cylinder head 2. It is dented.

Reference numerals 6 and 7 denote two intake ports that open to the one combustion chamber 5, and reference numerals 8 and 9 denote two exhaust ports that also open to the one combustion chamber 5, respectively.
The intake ports 6 and 7 and the exhaust ports 8 and 9 extend in the plan view (FIG. 2) and extend substantially parallel to the crankshaft (not shown) through the approximate center of the combustion chamber 5. The line 10 is arranged so as to be divided into left and right regions, and intake valves 11 and 12 are provided at openings of the intake ports 6 and 7 into the combustion chamber 5, and exhaust ports 8 and 9 are provided. Exhaust valves 13 and 14 are provided at openings of the combustion chamber 5 respectively. Further, intake pipes 15 and 16 for guiding the air-fuel mixture to the intake ports 6 and 7 are connected to the openings of the intake ports 6 and 7 to the side surface 2a of the cylinder head 2. An exhaust gas recirculation passage 21 from the exhaust system to the intake system is connected to the other intake pipe 16.

Inside the combustion chamber 5, the first chamber 5a in which one intake port 6 and one exhaust port 8 are open, the other intake port 7 and the other exhaust port 9 are formed in the combustion chamber 5.
Is formed integrally with the second chamber 5b which is open so that the raised portion 17 extends in a direction substantially perpendicular to the longitudinal center line 10, and the lower surface of the raised portion 17 is formed on the cylinder head. The lower surface of the piston 4 is formed to be substantially flush with the lower surface, and this lower surface is formed in the squish area 18 with respect to the top surface 4 a of the piston 4. Further, a spark plug 19 is attached to the cylinder head 2 and an electrode portion 19 of the spark plug 19 is provided.
It is screwed so that a is located in the squish area 18.

Then, in the cylinder head 2, in the latter half of the compression stroke by the upward movement of the piston 4,
A fuel injection valve 20 for injecting and supplying fuel into the first chamber 5a of the first chamber 5a and the second chamber 5b forming the combustion chamber 5 is screwed. The fuel injection valve 20 is mounted in such a posture that its fuel injection direction is directed to a portion of the top surface 4a of the piston 4 which is substantially directly below the electrode portion 19a of the spark plug 19.

In this structure, during the intake stroke due to the downward movement of the piston 4, each of the intake air-fuel mixture flowing into the combustion chamber 5 from both intake ports 6 and 7 has the first chamber 5a and the first chamber 5a inside the combustion chamber 5. By the left and right side surfaces 17a and 17b of the raised portion 17 which is divided into the two chambers 5b, as shown by arrows A and A'in FIGS. It is possible to reduce the mixing of the intake air-fuel mixture with each other and promote the longitudinal loop-shaped vortex flow in the intake air-fuel mixture.

Then, the intake air-fuel mixture of these two loop-shaped vortices flows in the compression stroke accompanying the upward movement of the piston 4.
Compressed while mixing with each other. Therefore, in the latter half of the compression stroke, the fuel is injected and supplied by the fuel injection valve 20 into one of the first chamber 5a and the second chamber 5b forming the combustion chamber 5. By doing so, the air-fuel ratio of the intake air-fuel mixture in the first chamber 5a becomes rich, while the air-fuel ratio of the intake air-fuel mixture in the other second chamber 5b becomes equal to that of the intake air-fuel mixture in the one first chamber 5a. Since the air-fuel ratio is leaner than the air-fuel ratio, the air-fuel ratio of the intake air-fuel mixture in one of the first chamber 5a and the second chamber 5b forming the combustion chamber 5 is made rich and the other second chamber 5b is made rich.
The air-fuel ratio of the intake air-fuel mixture at can be made lean, and stratified intake can be reliably achieved.

In this case, as another embodiment,
Of the first chamber 5a and the second chamber 5b forming the combustion chamber 5, the second chamber 5b is provided with an auxiliary fuel injection valve 22 as shown by a chain double-dashed line in FIGS. It may be configured to inject and supply a small amount of fuel from the valve 22. It should be noted that in the above-described embodiment, the spark plug 19 is used as the ignition means, but the present invention is not limited to this, and as shown in FIGS. 5 and 6, the portion of the electrode portion 19a in the spark plug 19 is shown. The sub-chamber cup 23 is fitted to the ignition chamber, and the head of the sub-chamber cup 23 is provided with ejection holes 23a and 23b for both the first chamber 5a and the second chamber 5b in the combustion chamber 5, respectively. May be applied.

Further, as described above, when the auxiliary fuel injection valve 22 is provided in the second chamber 5b in addition to the fuel injection valve 20 provided in the first chamber 5a, these fuel injection valves 20
If the auxiliary fuel injection valve 22 is configured to inject fuel to a portion outside the top surface 4a of the piston 4, as shown in FIG.
Alternatively, since the temperature of the portion far from the sub chamber cup 23 can be lowered by the injected fuel, the knock resistance can be improved.

Furthermore, as in each of the above-described embodiments, the first chamber 5a and the second chamber 5b in the combustion chamber 5 have the same size, and one intake port 6 and the other intake port 7 have the same inner diameter. In addition, not only the one exhaust port 8 and the other exhaust port 9 have the same inner diameter, but as shown in FIG. 7, the raised portion 17 in the combustion chamber 5 is displaced from the center of the combustion chamber 5. The fuel injection valve 20
The second chamber 5b on the side where the fuel injection valve 20 is provided is made smaller than the first chamber 5a not provided with the fuel injection valve 20, the inner diameter of one intake port 6 is made larger than the inner diameter of the other intake port 7, and The inner diameter of the exhaust port 8 may be larger than the inner diameter of the other exhaust port 9.

In addition, the top surface 4a of the piston 4
Of the electrode portion 19a of the spark plug 19,
Alternatively, in the head portion of the sub chamber cup 23, as shown in FIGS.
As shown by the dotted lines in FIGS. 4, 5 and 6, by providing a recess 24, the spark plug 19 is provided in the recess 24.
Of the electrode portion 19a in the above, or the sub chamber cup 23
The head may be configured so as to project.

[Brief description of drawings]

1 is a vertical sectional front view showing an embodiment of the present invention, which is indicated by I in FIG.
FIG. 3 is a sectional view taken along line I.

FIG. 2 is a bottom view taken along the line II-II in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a vertical sectional front view showing another embodiment of the present invention.

6 is a sectional view taken along line VI-VI of FIG.

FIG. 7 is a bottom view showing still another embodiment of the present invention.

[Explanation of symbols]

 1 Cylinder Block 2 Cylinder Head 3 Cylinder Bore 4 Piston 4a Piston Top Surface 5 Combustion Chamber 5a First Chamber 5b Second Chamber 6,7 Intake Port 8,9 Exhaust Port 10 Longitudinal Center Line 11,12 Intake Valve 13,14 Exhaust Valve 15, 16 Intake pipe 17 Raised part 18 Squish area 19 Spark plug 23 Sub chamber cup 20 Fuel injection valve 22 Auxiliary fuel injection valve

Claims (1)

[Claims] 1. A combustion chamber equipped with ignition means such as a spark plug has two intake ports each provided with an intake valve and two exhaust ports each provided with an exhaust valve, which are arranged at opposite positions. On the other hand, the combustion chamber is composed of a first chamber including one intake port and one exhaust port and a second chamber including the other intake port and the other exhaust port with the ignition means as a boundary. In the four-valve internal combustion engine, the fuel injection valve for injecting and supplying the fuel in the latter half of the compression stroke is provided in either one of the first chamber and the second chamber forming the combustion chamber. Fuel supply device for four-valve internal combustion engine.