JPS5840024B2 - Mixture supply mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mixture supply mechanism, and more particularly to a mixture supply mechanism for an internal combustion engine that supplies an appropriate mixture depending on the load.

Among the various performances of an internal combustion engine, in order to improve fuel consumption and exhaust gas purification, it is necessary to heat the air-fuel mixture and sufficiently vaporize the fuel.

However, when the air-fuel mixture is heated, the specific gravity of the air decreases, so the amount of intake air decreases, leading to a decrease in the output of the internal combustion engine, especially at high loads that require a large amount of air.

Conventionally, a mixture supply mechanism equipped with a carburetor having a primary venturi and a secondary venturi does not divide the intake manifold connected to the carburetor into a primary side and a secondary side, and instead supplies air from the two venturis. The mixture was then heated together with exhaust gas or engine cooling water.

Therefore, in the case of heating with exhaust gas, the intake air is heated excessively at high loads, reducing the amount of intake air and reducing the output.On the other hand, in the case of heating with cooling water, heating is insufficient. However, there was a drawback that sufficient fuel vaporization could not be obtained.

Additionally, in the past, there were some systems that separated the intake manifold into a primary side and a secondary side, but in this case, only the primary side was heated,
The secondary side was not heated.

Therefore, there is a drawback that fuel vaporization is poor and the output is reduced.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art described above and to provide a mixture supply mechanism that can appropriately heat and vaporize a mixture.

The present invention divides the intake manifold into a primary side and a secondary side, and -
The next side is heated by exhaust gas, and the second side is heated by engine cooling water.

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

The air-fuel mixture supply mechanism according to this embodiment consists of a carburetor 1 and an intake manifold 2 as a whole, and the carburetor 1 is of a two-barrel type having a primary venturi 3 and a secondary venturi 4.

The throttle valve 4A of the secondary venturi 4 is opened only when the load is high to supply the air-fuel mixture.

Reference numeral 3A indicates the throttle valve on the primary side.

An intake manifold 2 is connected to the carburetor 1 via a gasket 5, and a partition wall 6 is provided within a certain range on the intake side of the intake manifold 2.

Through this partition wall 6, the vicinity of the suction side of the intake manifold 2 is connected to a first intake passage 7 that communicates with the secondary venturi 3;
It is divided into a second intake passage 8 which communicates with the secondary venturi 4.

The partition wall 6 is provided with a water jacket 9 through which engine cooling water is guided in one direction, and the water jacket 9 has an approximately triangular cross section as a whole, and the second intake passage 8 side thereof is smooth. It is formed in a curved manner.

The air-fuel mixture flowing through the second intake passage 8 is heated appropriately by this water jacket 9.

Further, the first intake passage 7 is formed into an L-shape by the partition wall 6 and the water jacket 9, and then merges with the second intake passage 8.

An exhaust manifold 11 extends from the top of the L-shape of the first intake passage 7, that is, from the bottom end in the figure, with a heating plate 10 interposed therebetween.

A heating control plate 12 is rotatably provided in the exhaust manifold 11 near the heating plate 10, thereby making it possible to adjust the amount of heat transferred by the exhaust gas from the heating plate 10 to the first intake passage 7. .

Next, to explain the operation, during medium to light loads, the air-fuel mixture is sent only from the primary venturi 3, passes through the first intake passage 7, is heated by the heating plate 10, is sufficiently vaporized, and is introduced to the engine. It will be destroyed.

At high loads, the air-fuel mixture is sent from the secondary venturi 4,
This air-fuel mixture is appropriately heated in the second intake passage 8 by a water jacket 9 provided integrally with the partition wall 6, and then sent to the engine together with the air-fuel mixture passing through the first intake passage 7.

Here, if the inside of the second intake passage 8 is heated with exhaust gas like the first intake passage 7, it will be in a state of excessive heating, and the density of the air will decrease, resulting in a decrease in output.

Furthermore, if the second intake passage 8 is not heated at all, fuel vaporization will be poor, resulting in a decrease in output.

Therefore, as in the above embodiment, the second intake passage 8 is heated appropriately by the water jacket 9 through which engine cooling water flows.

The heating control plate 12 provided in the exhaust manifold 11 is positioned so that a large amount of exhaust gas collides with the heating plate 10 during the warm-up process of the engine, as shown by the solid line in the figure, and after warming up, the heating control plate 12 hits the heating plate 10 as shown in the figure. The heating plate 10 is rotated to a position where the exhaust gas does not collide with the heating plate 10 as much as shown by the dashed line.

In the above embodiment, the heating plate 10 is separate from the intake manifold 2 and the exhaust manifold 11, but the heating plate 10 is not limited to this, and may be integrated with the intake manifold 2 or the exhaust manifold 11.

Further, although the heating plate 10 is simply formed on a flat plate, it is not limited to this, and projections such as fins may be provided on the upper surface, lower surface, or both surfaces, or the heating plate 10 itself may be formed into a corrugated shape. This makes it possible to further improve heat transfer.

As described above, according to the present invention, the air-fuel mixture is appropriately heated and vaporized according to the load, and the fuel consumption rate and exhaust gas purification can be greatly improved without reducing the output. There is.

[Brief explanation of the drawing]

The accompanying drawing is a sectional view showing an embodiment of the air-fuel mixture supply mechanism according to the present invention. 1... Carburetor, 2... Intake manifold, 3... Secondary venturi, 4... Secondary venturi, 6... Partition Wall, 7...
First intake passage, 8... Second intake passage, 9...
...Water jacket, 11...Exhaust manifold as a heating section.

Claims (1)

[Claims] A mixture supply mechanism including a carburetor having a primary venturi and a secondary venturi that operates under high load to supply a mixture, and an intake manifold connected to the carburetor, at least one of the intake manifolds. The intake side is divided into a first intake passage communicating with the secondary venturi and a second intake passage communicating with the secondary venturi, and a heating section adjacent to the first intake passage into which exhaust gas flows; A mixture supply mechanism characterized in that a water jacket is provided adjacent to the second intake passage through which engine cooling water flows.