JPH0439413Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to the intake port of a dual intake valve engine.
In particular, the present invention relates to an intake port of a multiple intake valve engine that includes a helical port and a straight port equipped with an intake control valve.

[Conventional technology]

In order to provide a dual intake valve type internal combustion engine with high output and low fuel consumption, we have developed a helical port that spirals around the intake valve and a straight port that extends almost linearly toward the intake valve. and may be used together. Both ports are separated within the cylinder head with the partition walls being side walls of each other. Here, the straight port is provided with an intake control valve having a valve body having a cross-sectional shape of a passage so that the passage is closed during low-load operation and opened during high-load operation. In this way, even if a lean air-fuel mixture is supplied to the combustion chamber during low-load operation, the turbulence caused by the swirl flow caused by the helical port uniformizes the distribution of the air-fuel mixture in the combustion chamber and improves the ignitability of the lean air-fuel mixture. During high-load operation when the helical port has a large intake resistance, intake air is supplemented from the straight port.

Next, when supplying fuel, JP-A-59-147867
As disclosed in an embodiment of the above-mentioned issue, a fuel injection valve is disposed upstream of the above-mentioned partition wall that forms the side wall of the helical port and the straight port. In this case, the fuel injection valve is a two-way injection type, and fuel is injected toward the helical port and the straight port. In particular, by setting the amount of fuel injected toward the straight port to be smaller than the amount of fuel injected toward the helical port, it is possible to suppress fuel from adhering to the intake control valve and obtain good acceleration operation. It's summery.

[Problem that the invention attempts to solve]

By the way, even though the intake control valve has a valve body shaped like a passage, during low-load operation,
It is impossible to completely block the air-fuel mixture passing through the straight port, and the air-fuel mixture tends to leak from the gap between the port wall and the valve body. In particular, the fuel injected from the fuel injection valve is not sufficiently atomized and flows along the vertical lower wall of the straight port wall, and passes through the above-mentioned gap together with air as an air-fuel mixture. At this time, the amount of air passing through the gap is determined to be substantially constant depending on the size of the gap, whereas the amount of fuel passing through the gap is easily influenced by the amount of fuel flowing through the lower wall. For this reason,
Although the swirl generated from the helical port attempts to uniformly distribute the lean mixture in the combustion chamber, the air-fuel ratio of the mixture passing through the gap remains constant while the intake control valve is closed. If the air-fuel mixture is not determined, regions of extremely lean or rich mixture may be formed locally in the combustion chamber, and the uniform distribution of the air-fuel mixture may be slightly disturbed, resulting in poor ignition and flame propagation. There were limits to what could be done.

Therefore, the technical problem of the present invention is to directly pass the fuel through the gap on the lower wall side of the straight port and stabilize the amount of fuel passing through the gap, so that the fuel can flow from the straight port while the intake control valve is closed. The purpose is to stabilize ignition and flame propagation by making the leaking air-fuel mixture uniform.

[Means for solving problems]

According to the intake port of the multiple intake valve engine of the present invention, the means taken to solve the above technical problem is that a two-way fuel injection valve is disposed upstream of the partition wall, and one direction of injection is provided. is determined at the umbrella of the intake valve disposed in the helical port, and the other injection direction is determined at the gap formed between the valve body and the lower wall of the straight port, so that the injection amount on the straight port side is The purpose is to make the injection amount smaller than that on the helical port side.

[Effect]

According to this means, while the intake control valve is closed, a certain small amount of air passing through the gap on the lower wall side of the straight port is helical with respect to a certain amount of fuel injected toward the same gap in a smaller amount. The mixture becomes as lean as the mixture supplied from the port.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

As shown in FIG. 2, two intake valves 1 and 2 and two exhaust valves 3 and 4 are provided in a combustion chamber 5 in which a spark plug 5a is located in the center so as to sandwich the spark plug 5a. . The passages through which the intake valves 1 and 2 open and close are a helical port 7 and a straight port 8 formed in the cylinder head 6, respectively. The helical port 7 has a spiral shape around the intake valve 1 and contributes to creating a swirling flow within the fuel chamber 5. On the other hand, the straight port 8 extends substantially linearly toward the intake valve 2 in order to reduce flow path resistance. And helical port 7
The straight port 8 and the straight port 8 are divided within the cylinder head 6 by a partition wall 9 which is also a side wall of each other.

As shown in Figures 1 and 2, straight 8
An intake control valve 10 is disposed therein. The intake control valve 10 can be attached to the upper part of the cylinder head 6 by screwing a holder 12 through which the valve shaft 11 passes. At one end of the valve shaft 11, a valve body 13 having a cross-sectional shape approximately equal to that of the straight port 8 is provided.
is connected to the other end of the valve shaft 11.
A lever 14 is connected to an actuator (not shown) to rotate the valve body 13 about the valve body 13 . For example, the lever 14 that receives actuation from the actuator is the intake control valve 10.
The valve body 13 rotates in a direction to close the straight port 8 during low load operation, and rotates in a direction to open the straight port 8 during high load operation. Here, when the straight port 8 is closed by the intake control valve 10, a slight gap 15, 16 exists in order to avoid interference between the valve body 13 and the wall of the straight port 8. In particular, the gap 1 formed between the valve body 13 and the lower wall 17 of the straight port 8
5 is set larger than the gap 16 formed between the valve body 13 and the partition wall 9 forming the side wall of the straight port 8 in consideration of the degree of machining error, making it relatively easy for fluid to pass through.

Next, a fuel injection valve 18 is disposed on an upstream extension of the partition wall 9 in an intake manifold 19 that is connected to the cylinder head 5 via a gasket 20. The fuel injection valve 18 is installed with its tip inserted into the upper part of the intake manifold 19, and is located on the same side as the intake control valve 11. Here, the injection direction of the fuel injection valve 18 is the direction toward the helical port 7 and the direction toward the straight port 8.
They are separated in the direction of. Specifically, as shown by the dashed line in FIG. 2, the injection direction of the helical port 7 is determined by the umbrella of the intake valve 1 so that the injected fuel does not easily adhere to the wall of the helical port 7, and the straight port 7 The injection direction is determined by the gap 15 formed between the valve body 13 and the lower wall 17 of the straight port 8.
It is stipulated in Also, as shown in Figure 3,
In the fuel injection valve 18, the injection hole 18a on the straight port 8 side is larger than the injection hole 18a on the helical port 7 side.
b is set small, straight port 8
The injection amount on the helical port side is smaller than the injection amount on the helical port side.

Hereinafter, the functions and effects of this embodiment will be explained based on the drawings.

When the valve body 13 of the intake control valve 10 closes the straight port 8, such as during low-load operation, air-fuel mixture is supplied from the helical port 7 to the combustion chamber 5. At this time, the air-fuel mixture flows out from the shape of the helical port 7 while spiraling around the intake valve 1, and flows onto the peripheral wall w of the combustion chamber 5 as indicated by the arrow a in FIG. A strong swirl flow along the combustion chamber 5 occurs. Further, a small amount of air-fuel mixture leaks from the straight port 8 to the combustion chamber 5. That is, the gap 15 on the lower wall 17 side of the straight port 8
A constant small amount of air passing through mixes with a constant amount of fuel as it heads towards the gap 15,
Since the fuel injection amount on the straight port 7 side is set in advance to be small, the air-fuel mixture will be as lean as the mixture supplied from the helical port 7, and the spark plug will flow as shown by arrow b in Figure 2. It flows out in a straight line, passing around 5a.

As a result of the above, a homogeneous air-fuel mixture with increased turbulence expressed in the field of fluid mechanics is formed in the combustion chamber 5 due to the swirl flow, so even if the air-fuel mixture is lean, as is well known, Stable ignition and flame propagation are now possible. Also, as in the past,
When an air-fuel mixture with an inconsistent air-fuel ratio leaks from the straight port 8, the central region B of the combustion chamber 5 where the spark plug 5a is located is located on the outside of the arrow a and forms a wall w.
Since the turbulence is smaller than in region A, which is closer to the straight port 8, there is a tendency for local extremely lean or concentrated areas to form and the ignitability to deteriorate rapidly. Since the mixture is as lean as the mixture supplied from the helical port 7, the uniformity of the mixture in the combustion chamber 5 is maintained. As a result, the uniformity of the mixing chamber in the combustion chamber 5 of the dual intake valve engine is further improved compared to the conventional one, and even if the spark plug 5a is installed in the center of the combustion chamber 5, ignition is stable. spark plug 5
As the installation range of a is expanded, it becomes possible to make the air-fuel mixture even leaner.

[Effect of idea]

In this way, according to the means taken by the present invention, while the intake control valve is closed, a constant small amount of air passing through the gap on the lower wall side of the straight port is injected toward the same gap in a smaller amount. Since the mixture is as lean as the mixture supplied from the helical port for a given amount of fuel, it is possible to maintain the homogeneous mixture state formed within the combustion chamber without disturbing it. Therefore, according to the present invention, even if the air-fuel mixture is further diluted, ignition and flame propagation are stabilized, and fuel efficiency can be improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view including a straight port among the intake ports of a multiple intake valve engine according to an embodiment of the present invention, and FIG. 2 is a schematic plan view of the intake port of a multiple intake valve engine according to an embodiment of the present invention. FIG. 3 is a partial sectional view showing two injection holes of the fuel injection valve. 1, 2... Intake valve, 7... Helical port, 8
... Straight port, 9 ... Partition wall, 10 ... Intake control valve, 13 ... Valve body, 15, 16 ... Gap,
17...Lower wall, 18...Fuel injection valve.

Claims (1)

[Scope of utility model registration request] A helical port having a spiral shape around the intake valve and a straight port extending substantially linearly toward the intake valve are divided by a partition wall serving as a side wall of the helical port and the straight port, and the valve body has a passage cross-sectional shape. In an intake port of a dual intake valve engine in which an intake control valve is provided in the straight port, a two-way fuel injection valve is disposed upstream of the partition wall, and one injection direction is disposed in the helical port. and the other injection direction is determined in the gap formed between the valve body and the lower wall of the straight port, so that the injection amount on the straight port side is smaller than the injection amount on the helical port side. An intake port for a multiple intake valve engine.