JPH022936Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an intake device for an engine with a carburetor.

[Conventional technology]

FIG. 4 and FIG. 5 show an example of a conventional intake device for a four-cylinder gasoline engine. In the figure, 1 is an engine body, 2 is an intake manifold, 3 is a carburetor, 4 is an air horn, 5 is an intake duct, and 6 is an air cleaner. After being filtered by an air cleaner, the intake air enters the air horn 4 through the intake duct 5, where it is deflected at a substantially right angle and then introduced into the carburetor 3.

[Problem that the invention attempts to solve]

However, the above-mentioned conventional device has the following problems.

Since the flow of intake air changes rapidly in the air horn 4 directly above the carburetor 3, the air flowing inside the carburetor 3 is biased in one direction. For this reason, the fuel ejected from the carburetor 3 is distributed unevenly and supplied to each cylinder of the engine, and the mixture concentration is not uniform, resulting in engine malfunctions such as reduced output, misfires, and smoke emissions.

The present invention was developed in view of the above, and an object of the present invention is to stabilize combustion by equalizing the distribution of air-fuel mixture to each cylinder in an intake system provided with an air horn and an intake duct.

[Means and actions for solving problems]

In order to solve the above-mentioned problems, this invention has a bottomed cylindrical guide tube with one end open, which has an intake passage formed by cutting out a part of the circumference inside the air horn. It is characterized by being fitted and installed with the bottomed side touching and fixed to the inner surface of the air horn.

By having such a configuration, the present invention corrects the moving direction of the intake air just before the carburetor by setting the direction of the notch in the guide tube in an appropriate direction, and adjusts the concentration of the air-fuel mixture to each cylinder. It can be made uniform.

〔Example〕

1 to 3 of the present invention.
To explain the embodiment, 3 is a carburetor, 4 is an air horn, and 5 is a suction duct connected to an air cleaner 6 (see FIG. 4). 10 is a guide tube fitted into the air horn 4. The guide tube 10 is a cylindrical body with a covered top, and its lower end 10b is fitted into the outlet hole 4a of the air horn 4, and its upper end is fixed in contact with the inner surface of the air horn. 10a is a notch bored on the circumference of the guide tube 10. The notch 10 is oriented and sized experimentally to modify the flow throughout the suction system.

In the engine with the above configuration, air from the air cleaner 6 enters the air horn 4 from the intake duct 5, passes through the passage 11 between the outer surface of the guide cylinder 10 and the inner surface of the air horn 4, and enters the notch 10a.
Enter into the guide tube 10 from. The intake air that has been directed by the notch 10a and has passed through the guide tube 10 enters the carburetor 3 and is mixed with fuel, and is sent to the intake manifold 2.
It then flows into the engine. In this case, notch 1
Since the flow distribution of the intake air to the carburetor 3 is adjusted by 0, the air-fuel mixture from the carburetor 3 is uniformly distributed to each cylinder.

Fig. 3 shows an experimental example when the present invention is applied to a four-cylinder engine. be. As is clear from the figure, the conventional model B without a guide tube has a variable air-fuel ratio of 13.4 to 16.2 in each cylinder, resulting in poor air-fuel mixture distribution, while the inventive model has a mixed air-fuel ratio of 13.1 to 13.9. The distribution of energy is even.

[Effect of idea]

The present invention is constructed as described above, and according to the present invention, the distribution of the air-fuel mixture in each cylinder can be made uniform by appropriately setting the direction and size of the notch in the guide cylinder through experiments or the like. This makes it possible to stabilize combustion, and because the guide tube is installed with both ends fixed, vibration resistance against air vibration and mechanical vibration can be improved.

[Brief explanation of the drawing]

1 to 3 show one embodiment of the present invention, FIG. 1 is a sectional view of the main part, and FIG. 2 is a -
The cross-sectional view and FIG. 3 are diagrams showing experimental results of the present invention. 4 and 5 show an example of a conventional gasoline engine intake device, and FIG. 4 is an external view,
FIG. 5 is a cross-sectional view of FIG. 4. 1...engine body, 3...carburizer, 4...air horn, 10...guide tube, 10a...notch.

Claims (1)

[Scope of utility model registration request] An air horn that deflects the intake air flow approximately at right angles is provided in the intake passage between the air cleaner and the carburetor, and one end of the air horn is open at one end, with a part of the circumference cut out to form the intake passage. An engine intake device characterized in that a bottomed cylindrical guide tube is installed with one open end fitted into an outlet hole of an air horn and the bottomed side fixed in contact with the inner surface of the air horn.