JPS5918542B2 - Internal combustion engine intake system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an intake system for an internal combustion engine.

Conventionally, when trying to improve the high-speed performance of an engine, the negative pressure in the crankcase and the intake pulsating flow in the connecting cylinder (the connecting cylinder consists of a manifold and packing)
The intake pulsating flow (which is caused by the opening and closing of the intake valve) does not match, resulting in poor power feeling in medium and low speed ranges and poor fuel efficiency.

The present invention has been made in view of the drawbacks of the conventional examples, and its purpose is to obtain high absorption efficiency over the entire rotation range by smoothing the intake air into the engine body throughout the entire process, and to improve output and An object of the present invention is to provide an intake device for an internal combustion engine that can improve characteristics in terms of both fuel efficiency.

Hereinafter, the present invention will be described in detail according to illustrated embodiments.

The connecting cylinder S is arranged between the engine body E and the carburetor outlet Ka of the carburetor, has a substantially cylindrical shape, and is composed of a manifold M and a packing R.

Here, the manifold M is divided into two stages, and the tapered cylindrical part Ma connected to the carburetor outlet Ka is formed so that the diameter becomes gradually smaller toward the engine body side (i.e., to the left in the figure). Yes, the diameter of the large diameter part of the tapered cylindrical part Ma is L
If the diameter of one small diameter portion is 1, then L>1.

On the other hand, the straight cylindrical part Mb of the connecting cylinder S that is connected to the engine body E via the gasket R has a straight cylindrical shape with an inner diameter of 1, and the carburetor outlet Ka has a straight cylindrical shape. It is finished to have the same diameter as part Mb.

Further, the turning groove is recessed all around the inner peripheral surface of the tapered cylindrical part Ma of the manifold M, and an air pump P is connected to this turning groove. A is connected to supply clean air.

This air cleaner A is further connected to the carburetor K, and supplies clean air to the carburetor K as well.

Note that this air pump P rotates synchronously with the engine body E at the same speed.

The direction of rotation is the direction of the arrow in the figure (counterclockwise).

Further, a branch pipe 2 is led out from the straight cylindrical portion Mb of the manifold M, and an air chamber T is connected to the tip of this branch pipe 2.

This air chamber T is formed in a substantially spherical or cylindrical shape, and the branch pipe 2 is inclined so that its outlet 3 opens diagonally toward the engine body. The air-fuel mixture that flows backward is likely to be sucked into the air chamber T, and conversely, the air-fuel mixture in the air chamber T when the intake valve is open is likely to flow out toward the engine body.

When the internal combustion engine rotates, the air cleaner A
Cleaner air is supplied to the carburetor K, mixed with the fuel sprayed out in the form of mist inside the carburetor to form an air-fuel mixture, which passes through the connecting cylinder S and is supplied into the engine body E.

On the other hand, clean air is discharged from the air pump P into the swirling chain, and this air flows inside the swirling groove while swirling in the tangential direction of the swirling groove, and then flows along the inner circumferential surface of the connecting cylinder S. This prevents a part of the air-fuel mixture from coming into contact with the inner circumferential surface of the connecting cylinder S and forming a liquid flow adhering to the wall surface.

In this way, a uniformly dispersed air-fuel mixture is sucked into the engine body E, but the intake valve opens and closes in accordance with the movement of the piston inside the engine body E. As a result, the air intake into the engine body E becomes intermittent, and the air-fuel mixture flow velocity V.

It will change from −〇 to 80 m/s.

In other words, the suction valve closes and V.

= around 0, and if an excessive amount of air-fuel mixture is supplied into the connecting cylinder S, these excess air-fuel mixtures may hit the intake valve and flow backwards, or may be supplied later into the connecting cylinder S. Due to the pressure difference, the air flows into the air chamber T, which has a negative pressure from the connecting cylinder S, through the branch pipe 2, obstructs the normal flow of the air-fuel mixture in the connecting cylinder S, and flows into the carburetor. There is no possibility of fuel splashing caused by
Further, the air-fuel mixture that flows into the air chamber T often flows in the form of a vortex.

While the intake valve is closed, the air-fuel mixture is sucked into the air chamber T, and when the intake valve is opened, as the piston moves, the inside of the engine body E becomes negative pressure, and the air chamber T is filled. The existing air-fuel mixture and the air-fuel mixture newly supplied into the connecting cylinder S from the carburetor K are together sucked into the engine body E.

In addition, in order to exhibit this function to the highest degree from high speed to low speed rotation range, it is determined by the volume and shape of the air chamber T, and the length and diameter of the branch pipe 2.

As shown diagonally above, the present invention connects the carburetor and the engine body through a connecting cylinder, and has an air chamber that takes in excess air-fuel mixture supplied into the connecting cylinder when the intake valve of the engine body is closed. Since the branch pipe is connected to the connecting cylinder, when the intake valve of the engine body closes, the air-fuel mixture that hits the intake valve and flows back, and the air-fuel mixture that is later supplied into the connecting cylinder, smoothly enters the air chamber. will be inhaled.

On the other hand, when the intake valve opens, the air-fuel mixture filling the air chamber and the air-fuel mixture supplied later into the connecting cylinder are sucked into the engine body, regardless of whether the intake valve is opened or closed. The flow velocity can be smoothed, the engine body and the intake air can be matched from high speed to low speed range, and as mentioned above, when the intake valve opens, the mixture in the air chamber is mixed with the mixture supplied into the manifold. Since it flows into the engine body as one body, it is possible to achieve high intake efficiency over the entire rotation range, and has the advantage of being able to improve characteristics in terms of both output and fuel efficiency.

Note that this device can be used not only for 4-cycle engines but also for 2-stroke engines.

[Brief explanation of the drawing]

The figure is a schematic longitudinal sectional view showing one embodiment of the present invention, where K is a carburetor, S is a connecting cylinder, T is an air chamber, and 2 is a branch pipe.

Claims (1)

[Claims] 1 Connect the carburetor and the engine body with a connecting cylinder, and connect the air chamber to the connecting cylinder with a branch pipe to suck in the excess air-fuel mixture supplied into the connecting cylinder when the intake valve of the engine body is closed. An intake system for an internal combustion engine, characterized in that the intake system is connected to each other.