JPS6113086B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention effectively performs stratified combustion in the combustion chamber of an internal combustion engine using a mixture whose total air-fuel ratio is leaner than the stoichiometric air-fuel ratio, making it possible to achieve high output and release harmful components. This relates to an internal combustion engine that is designed to reduce energy consumption.

In conventional internal combustion engines, per combustion chamber,
High-output internal combustion engines are known that are equipped with two or more intake ports that are opened and closed by intake valves to increase intake efficiency and increase output during high-load operation. While these engines can provide high output, they also release a large amount of harmful components such as unburned components into the atmosphere, polluting the atmosphere, so they have hardly been put into practical use in recent years.

However, since the above-mentioned high-output internal combustion engine has a small weight per unit of output, by limiting the output, the total weight of the internal combustion engine can be reduced, and as a result, theoretically, the amount of combustion consumed will be reduced, which will be effective in terms of exhaust gas countermeasures. In addition to this, if the combustion process in the combustion chamber can be improved and good combustion can be achieved with an air-fuel mixture whose total air-fuel ratio is leaner than the stoichiometric air-fuel ratio, conventional high-power internal combustion It is possible to obtain a high-output, low-pollution internal combustion engine by minimizing the decrease in output during high-output operation and significantly reducing the release of harmful components compared to the engine.

The present invention aims to provide an internal combustion engine with a simple structure that can achieve the above object.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. E is an internal combustion engine body, and the combustion chamber 3 formed on the cylinder 1 into which the piston 2 is slidably connected, as clearly shown in FIG. First and second intake ports 5 and 6 are opened in parallel and spaced apart on the left and right sides of the combustion chamber 3 on one side, and one exhaust port 7 is provided on the other side. The two intake ports 5, 6 and the exhaust port 7 are respectively connected to the cylinder head 4 of the internal combustion engine main body E.
The intake pipe 8 and the exhaust pipe 9 are connected to each other. The first and second intake ports 5 and 6 are opened and closed by first and second intake valves 10 and 11, respectively, which are supported on the cylinder head 4 so as to be movable up and down. The exhaust port 7 is opened and closed by an exhaust valve 12 supported by the cylinder head 4 so as to be movable up and down. The first and second intake valves 10, 11 and the exhaust valve 12 are connected to a conventionally known valve operating mechanism V provided on the cylinder head 4.
It is forced to open and close at a predetermined timing.

Further, as shown in FIG. 2, an ignition plug P is screwed onto the cylinder head 4, and an electrode of the ignition plug P faces into the combustion chamber 3 near the first intake port 5.

The inside of the intake pipe 8 is separated into an upper separated intake passage 14 and a lower separated intake passage 15 by a twisted partition wall 13 that extends integrally from the upper surface of the inner wall of the intake pipe 8. Due to twisting,
The downstream end of the upper separated intake passage 14 is connected to the second intake port 6,
Further, the downstream ends of the lower separated air intake passages 15 are communicated with the first air intake ports 5, respectively. Therefore, the air-fuel mixture introduced into the intake pipe 8 is divided into upper and lower separated intake passages 14 and 15 by the partition wall 13, and flows into the combustion chamber 3 through the second and first intake ports 6 and 5. In that case, the upper and lower separated intake passages 14, 1
5 is given a swirling force in the flow direction by the twisted partition wall 13, and the ignition plug P electrode near the first intake port 5 is placed in front of the lower separation intake passage 15 in the flow direction of the mixture. will come.

A carburetor C is connected to the outer end of the intake pipe 8, and a choke valve 18 is pivotally supported on the upstream side of the intake passage 16, and a throttle valve 19 is pivotally supported on the downstream side of the intake passage 16, with a bench lily 17 in between. 16, a low speed nozzle 21 is opened near the throttle valve 19, a slow speed nozzle 20 is opened downstream of the throttle valve 19, and a high speed nozzle 22 is opened inside the bench lily 17. Slow speed nozzle 20, low speed nozzle 21 and high speed nozzle 22
Both are communicated with the float chamber 23. Since the vaporizer C is conventionally known, a detailed explanation thereof will be omitted.

Next, the operation of the embodiment of the present invention configured as described above will be explained. When the internal combustion engine is in no-load operation such as idling, the throttle valve 19 of the carburetor C is in a substantially fully closed state, so the fuel is the throttle valve 19
When the throttle valve 19 is slightly opened to operate the engine at a low load, the low-speed nozzle 21 also exists downstream of the throttle valve 19, and the fuel is ejected only from the slow speed nozzle 20 located downstream of the is ejected from both the slow speed nozzle 20 and the low speed nozzle 21. In addition, in order to operate the engine at a higher load, the throttle valve 1
9 in the opening direction, fuel injection from the slow and low speed nozzles 20 and 21 stops, and fuel is ejected from the high speed nozzle 22 opened on the lower surface of the bench lily 17, allowing the engine to operate from idling to high load. Fuel is supplied for the operation of the vehicle.

By the way, slow speed, low speed and high speed nozzles 20,2
Since nozzles 1 and 22 are both open at the bottom of the intake passage 16 of the carburetor C, the absolute flow rate of fuel ejected from the nozzles 20, 21 and 22 is equal to that of the intake passage 1.
There is a tendency for the amount to increase in the lower layer of 6 and to decrease in the upper layer, and a lean mixture with a high air-fuel ratio is generated in the upper layer of the intake passage 16 of the carburetor C, and a rich mixture with a low air-fuel ratio is generated in the lower layer. be done. Then, the rich air-fuel mixture in the lower layer of the intake passage 16 of the carburetor C passes through the lower separated intake passage 15 and reaches the first intake port 5 on the side closer to the ignition center P, and when the first intake valve 10 is opened, the rich mixture flows into the combustion chamber. On the other hand, the lean air-fuel mixture in the upper layer of the intake passage 16 of the carburetor C is sucked into the second intake port 6 on the side away from the spark plug P through the upper separated intake passage 14. When the rich and lean mixtures flow through the lower and upper separated intake passages 15 and 14,
It is swirled by the twisted partition wall 13 and flows into the combustion chamber 3 in the form of a vortex. Therefore, near the end of the intake stroke, a rich air-fuel mixture layer that is richer than the stoichiometric air-fuel ratio exists in the combustion chamber 3 around the first intake port 5, and a stoichiometric air-fuel mixture layer exists around the second intake port 6. There is a lean mixture layer that is leaner than the fuel ratio. Even if there is evaporation of fuel or diffusion of a rich mixture during the upward compression stroke of the piston 2, at the ignition timing near the end of the compression stroke, the area around the ignition plug P is lower than the stoichiometric air-fuel ratio, where the best combustion occurs. The spark plug P will be surrounded by a mixture with a slightly rich air-fuel ratio.
By the ignition by the electric spark, the rich mixture around it is reliably and easily ignited, and the flame thus generated grows and propagates to the remaining lean mixture layer including the area around the second intake port 6. However, as a result, good stratified charge combustion is performed from the rich air-fuel mixture layer to the lean air-fuel mixture layer, and overall good stratified charge combustion is performed with the air-fuel mixture having an air-fuel ratio leaner than the stoichiometric air-fuel ratio.

As described above, according to the present invention, the internal combustion engine main body E
First and second intake ports 5 and 6 opened and closed by intake valves 10 and 11, respectively, are opened and separated from each other in a combustion chamber 3 corresponding to a cylinder 1 formed in
A single intake pipe 8 that communicates with the first and second intake ports 5 and 6 is communicated with an intake passage 16 of a single carburetor C, and a single intake pipe 8 is connected to the intake pipe 8 of the carburetor C. Lower and upper separated intake passages 15, 1 into which the rich air-fuel mixture generated in the intake passage 16 of the
A partition wall 13 is provided which divides the lower and upper separated intake passages 15 and 14 into first and second intake ports 5 and 6, respectively.
Since the ignition plug P electrode faces into the combustion chamber 3 near the first intake port 5 in the forward direction of the air-fuel mixture flow direction, the lower separated intake passage 15
The rich mixture introduced via the first intake port 5 and the lean mixture introduced via the upper separation intake passage 14 and the second intake port 6 are separated as much as possible to mix the mixture. In addition, only the rich air-fuel mixture can be efficiently collected around the spark plug P near the first intake port 5 and ignited and burned easily and reliably. Although it is a high-output internal combustion engine with two intake ports 5 and 6 per combustion chamber 3 that are opened and closed by intake valves 10 and 11, the engine as a whole has an extremely lean air-fuel ratio than the stoichiometric air-fuel ratio. Stable stratified combustion becomes possible over the entire operating range, increasing intake efficiency during high-load operation and achieving high engine output, while at the same time reducing the amount of harmful components such as end combustion components generated and purifying exhaust gas. can contribute to

In particular, the partition wall 13 separates the downstream ends of the lower and upper separated intake passages 15 and 14 from the first and upper separated intake passages so as to swirl the air-fuel mixture passing through the lower and upper separated intake passages 15 and 14, respectively. Since it is twisted so as to communicate with the two intake ports 5 and 6, the partition wall 13 ensures that each air-fuel mixture flowing into the upper and lower separated intake passages 14 and 15 is swirled into a vortex. Therefore, the unevaporated fuel in each mixture is vaporized until each mixture that has become a swirl flows through the first and second intake ports 5 and 6 and reaches the combustion chamber 3. This is effectively promoted and the density distribution of each air-fuel mixture is made uniform, so that the stratified combustion of each air-fuel mixture within the combustion chamber 3 can be performed more easily.
Moreover, the partition wall 13 has the original function of partitioning the intake pipe 8 into upper and lower separated intake passages 14 and 15, and a swirling flow generating plate that generates a swirling flow in the air-fuel mixture flowing through each of the separated intake passages 14 and 15. Therefore, although one combustion chamber 3 has two intake ports 5 and 6, only one intake pipe 8 and one carburetor C are required, and the partition wall 13 has two intake ports 5 and 6 per combustion chamber 3. Coupled with the fact that it is provided only within 8, the overall structure can be significantly simplified, which can contribute to cost reduction.

[Brief explanation of the drawing]

The drawings show one embodiment of the internal combustion engine of the present invention.
The figure is a vertical sectional side view of Figure 2, and Figure 2 is a vertical sectional side view of Figure 1.
FIG. 3 is a partial cross-sectional view along the line shown in FIG. 1; FIG. 1... Cylinder, 3... Combustion chamber, 5, 6... First,
Second intake valve, 8... Intake pipe, 10, 11... Intake valve, 13... Partition wall, 14... Upper separated intake passage, 1
5...Lower separated intake passage, 16...Intake passage, C...
Carburetor, E... Internal combustion engine body, P... Spark plug.

Claims (1)

[Claims] 1 First and second intake ports 5 and 6 opened and closed by intake valves 10 and 11, respectively, are opened and separated from each other in the combustion chamber 3 corresponding to the cylinder 1 formed in the internal combustion engine main body E, and A single intake pipe 8 communicating with the first and second intake ports 5 and 6 is communicated with an intake passage 16 of a single carburetor C, and inside the intake pipe 8,
A partition wall 13 is provided which divides the space into lower and upper separated intake passages 15 and 14 into which the rich mixture and lean mixture generated in the intake passage 16 of the carburetor C are respectively introduced. The downstream ends of the lower and upper separated air intake passages 15 and 14 are connected to the first and second air intake ports 5 and 6, respectively, so as to swirl the mixture passing through the lower and upper separated air intake passages 15 and 14, respectively. The lower separated intake passage 1 is twisted so as to communicate with the lower separated intake passage 1.
An internal combustion engine in which an ignition plug P electrode faces into the combustion chamber 3 near the first intake port 5 at the front in the air-fuel mixture flow direction.