JPS5845594B2 - Intake pipe for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intake pipe for an internal combustion engine, and more specifically, to an intake pipe for an internal combustion engine.
This invention relates to an intake pipe for an internal combustion engine that has been improved to prevent liquid fuel traveling along the wall surface of the intake pipe from being sucked directly into the cylinder.

In order to reduce harmful components in the exhaust gas of internal combustion engines, it is effective to make the mixture of liquid fuel and air uniform in concentration, but in reality, the mixture obtained in the vaporizer is used for fuel cooling, etc. Due to this, liquid fuel that is not atomized may adhere to the wall of the intake pipe, travel along the wall surface, enter some cylinders, and burn within that cylinder.

This air-fuel mixture containing liquid fuel partially becomes a rich fuel, resulting in incomplete combustion due to lack of oxygen, and unburned harmful components are released into the atmosphere, impairing exhaust purification performance.

Further, when liquid fuel flows along the wall surface and flows into some cylinders, there is a problem that the concentration of the air-fuel mixture taken into each cylinder varies, resulting in uneven distribution of the air-fuel mixture among the cylinders.

Therefore, the present invention captures the liquid fuel traveling along the wall surface of the intake pipe, and gradually sucks out the captured fuel in fine particles using airflow and supplies it to each cylinder, thereby improving the distribution of the air-fuel mixture to each cylinder. The purpose is to equalize the exhaust gas, reduce unburned harmful components in the exhaust gas, and further improve fuel efficiency.

Hereinafter, details of the present invention will be explained with reference to the accompanying drawings.

In the figure, reference numeral 1 indicates an air cleaner, and a carburetor 2 is connected to this air cleaner.

This carburetor 2 is connected to the lower end of the mixture passage 3 with an intake pipe 4 that extends horizontally in the left-right direction. is distributed and supplied.

Inside the intake pipe 4, a groove 41 for trapping liquid fuel is formed at the bottom thereof, and the groove 41 is provided throughout the horizontal portion of the intake pipe 4 along the pipe direction.

Further, inside the intake pipe 4, a concave first trapping member 42 is fixed to the bottom of the central riser portion communicating with the mixture passage 3 of the carburetor, and the first trapping member 42 is fixed to the bottom of the central riser portion that communicates with the mixture passage 3 of the carburetor. Liquid fuel can be temporarily stored in the recess.

The liquid fuel trapping member 42 is made of a porous material such as sintered metal, and once absorbs the liquid fuel, it is now able to release the fuel in the form of ultrafine particles by the airflow flowing through the intake pipe. ing.

Further, at the cylinder-side terminal end of the groove 41 formed in the intake pipe 4, a second cylindrical trapping member 43 made of a porous material is erected near the branch point where it splits into the manifold pipe 4a. Thus, the liquid fuel contained in the air-fuel mixture is captured as it flows through the groove 41 to the manifold pipe 4a.

Since the present invention has the above-described configuration, even if the fuel in the air-fuel mixture in the intake pipe leading from the carburetor to each cylinder may become droplets and travel along the wall surface due to reasons such as fuel cooling, This liquid fuel is transferred to the first and second capture members 42, 4.
3 and grooves 41, all of them are once captured at multiple locations.

In particular, in the case of the intake system of a horizontally opposed multi-cylinder internal combustion engine, liquid fuel is first generated in the carburetor due to fuel cooling, etc., flows down the inner wall of the mixture passage 3, and flows down the center riser of the intake pipe 4. (2) Some of the liquid drips directly into the intake pipe 4; (2) Some of the liquid drops directly into the intake pipe 4 from the lower end of the mixture passage 3 and adheres to the inner wall of the intake pipe 4; (2) The process of passing through the intake pipe 4. In some cases, droplets of fuel adhere to the pipe wall and flow into the cylinder.

In this case, according to the present invention, ([) the concave first trapping member 42 is provided in the riser part in the intake pipe 4 facing the mixture passage 3 of the carburetor 2, so that the mixture is The liquid fuel dripping from the passage 3 into the riser section is captured by the concave first capturing member 42. (11) Also, the liquid fuel that adheres to the inner wall of the intake pipe 4 and flows into the bottom of the intake pipe 4 is captured by the concave first capture member 42. Since the groove 41 is provided along the pipe direction of the intake pipe over the entire length of the intake pipe, it is possible to ensure that the groove 41 is captured in the groove 41, and the curve is further transmitted inside the groove 41. The liquid fuel that reaches the end of the intake pipe 4 is captured by a cylindrical second capture member 43 installed upright at the end of the cylinder side of the groove 41, and is also captured by droplets floating in the air-fuel mixture. Fuel is also captured by contacting the cylindrical second capture member 43.

In this way, the liquid fuel and droplets in the air-fuel mixture that travel along the walls of the intake system from the carburetor to each cylinder,
1st. All of the particles are once captured at multiple locations by the second capturing member and the groove, and then gradually sucked out in fine particles by the airflow and sucked into each cylinder.

Therefore, according to the present invention, the liquid fuel traveling along the wall surface is
Since it does not directly enter the cylinder, uneven distribution of the mixture between cylinders due to the inflow of liquid fuel can be eliminated, and the distribution of the mixture to each cylinder can be made even. In addition, it is possible to further reduce the discharge of unburned components. By reducing the amount, it is possible to prevent deterioration of exhaust purification performance, and in addition, it is possible to reduce loss in fuel consumption, thereby improving fuel efficiency.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway explanatory view of an internal combustion engine equipped with an intake pipe according to the present invention, FIG. 2 is a sectional view showing a part of the intake pipe, and FIG. 3 is a cross-sectional view of FIG. 2. 4... Suction pipe, 41... Concave groove, 42...
...Container-shaped capture member, 43...Cylindrical capture member.

Claims (1)

[Claims] 1 For a multi-cylinder internal combustion engine in which a mixture is distributed and supplied to a plurality of cylinders arranged on the left and right through a horizontal intake pipe extending from the mixture passage of a vertically arranged carburetor to the left and right of the passage. In the intake pipe, a concave first liquid fuel trapping member made of a porous material is provided at the bottom of the central riser portion of the intake pipe that communicates with the mixture passage of the carburetor, and the concave opening thereof is connected to the carburetor mixture passage. The inside of the intake pipe, which extends horizontally from the center riser part in the left-right direction, is provided so as to protrude into the intake pipe from the bottom part so as to face the central riser part.
A concave groove for capturing liquid fuel is formed along the pipe direction over the entire length of the intake pipe, and a second liquid fuel trapping member made of a porous material is erected in the pipe at the cylinder-side terminal end of the concave groove. An intake pipe for an internal combustion engine, comprising: an intake pipe for an internal combustion engine;