JPS588901Y2 - engine intake system - Google Patents

Description

[Detailed explanation of the idea] This invention relates to an engine intake system.

BACKGROUND ART Intake systems are conventionally known that allow the air-fuel mixture supplied to the engine to flow tangentially into the combustion chamber to strengthen the swirl of the air-fuel mixture within the combustion chamber, thereby improving combustion performance. .

A specific example of the above-mentioned well-known intake system will be explained with reference to FIGS. 1 and 2. 1 is a cylinder head, 2 is a cylinder block, 3 is a combustion chamber formed by the cylinder head 1 and the cylinder block 2, and 4 is a combustion chamber formed by the cylinder head 1 and the cylinder block 2. An intake port provided in the cylinder head 1 has one end opening into the combustion chamber 3 and the other end opening into the cylinder head side wall 1a, and the opening in the cylinder head side wall 1a communicates with an intake pipe (not shown).

Reference numeral 5 designates an intake valve that opens and closes a valve seat 6a provided at an opening 6 of the intake port 4 on the combustion chamber side.

The combustion chamber side opening 6 of the intake port 4 and the sidewall side lower opening to the cylinder head side wall 1a are offset in the horizontal direction, and the intake port 4 is located from the sidewall side lower to the cylinder head sidewall 1a. a linear portion 8 extending in a substantially perpendicular direction (i.e., horizontal direction);
It is composed of a straight part 8 and a curved part 9 that curves in the tangential direction of the cylinder and communicates with the combustion chamber side port 6.

Note that 10 is a piston, 11 is an opening of an exhaust port on the combustion chamber side, and 12 is a spark plug.

In the above conventional intake port structure, as shown in FIG. It is set t below the plane P2 parallel to the linear part side surface 8a, and it is difficult to set the 41st plane above the 22nd plane in terms of arrangement.

Therefore, in this case, the air-fuel mixture flowing above the 22nd surface flows in the 81 direction due to the curved portion 9, but the air-fuel mixture flowing between the 22nd surface and the 41st surface flows in the S2 direction.

In other words, the swirl in the S1 direction was weakened by the flow in the 82 direction opposite to the S1 direction, so a strong swirl could not be obtained.

Furthermore, when the air-fuel mixture on the S2 side collides with the wall of the intake port 4, fuel particles adhere to the wall of the intake port, and these fuel particles flow into the combustion chamber 3 in the form of a film, impeding the improvement of combustibility. was.

This invention provides an air intake device that eliminates the above-mentioned drawbacks.

An embodiment of this invention will be explained with reference to FIGS. 3 and 4.

Note that the same parts as in FIGS. 1 and 2 are designated by the same reference numerals, and their explanation will be omitted.

The curved portion 9 (here, the curved portion 9 hangs down from the upper surface of the intake port 4 to the extension surface P3 of the straight portion bottom surface 8b, and extends to the periphery of the combustion chamber side opening 6 (preferably the valve seat 6a). A guide vane 13 extending in substantially the same direction as the bending direction is provided within a range between a plane P2 that is in contact with and parallel to the side surface 8a of the linear part 8 and an extended plane P1 of the linear part side surface 8a on the bending direction side. It is something that

In the embodiment described above, the air-fuel mixture flowing between the 12th surface and the 11th surface flows in 83 directions by the guide vanes 13, and flows in the tangential direction of the combustion chamber 3 together with the air-fuel mixture flow in the S1 direction.

Further, the fuel particles contained in the air-fuel mixture are divided into two parts and adhere to the wall surface of the intake port 4 and the guide vane 13, so that the fuel particles can be efficiently diffused into the air-fuel mixture.

Furthermore, since the guide vanes 13 were provided only in the minimum necessary range to prevent the mixture flow in the S2 direction in the conventional device,
Increase in intake resistance and decrease in intake air filling efficiency can be minimized.

Furthermore, the guide vane 13 may be appropriately selected so as to extend in substantially the same direction as the bending direction of the intake port 4 within the range surrounded by the 11th and 12th faces, but when a single guide vane 13 is provided, As shown in FIG. 3, it is preferable to provide it approximately at the center of the intake port 4.

As explained above, this invention horizontally deviates the combustion chamber side opening of the intake port provided in the cylinder head and the cylinder head side wall side opening, and also moves the intake port from the cylinder head side wall side opening to the cylinder head. Consisting of a straight part extending substantially perpendicular to the head side wall, and a curved part continuous with the straight part, curved from the straight part in the tangential direction of the cylinder, and communicating with the combustion chamber side opening,
In an engine intake system configured to allow the intake air-fuel mixture to flow tangentially into the combustion chamber, the above-mentioned curved portion hangs down from the top surface of the intake port to the extension surface of the bottom surface of the straight portion, and A guide vane extending in substantially the same direction as the bending direction within the range between a surface that is in contact with the periphery of the combustion chamber side opening and parallel to the side surface of the straight section and an extended surface of the side surface of the straight section on the bending direction side. Since it has been established,
The air-fuel mixture introduced into the intake port becomes a strong swirl and flows into the combustion chamber, and the combustibility within the combustion chamber is significantly improved.

In addition, the fuel particles contained in the air-fuel mixture are separated and adhered to the guide vanes on the wall of the intake port, and these adhering fuel particles are uniformly mixed and diffused into the air-fuel mixture with strong directionality. Therefore, flammability is further improved.

Further, since the guide vanes are provided only in the minimum necessary range, the reduction in intake air filling efficiency can be suppressed to the minimum.

[Brief explanation of the drawing]

Fig. 1 is a schematic plan view of a conventional example of an engine intake system, Fig. 2 is a side view cut along the line ■-■ of Fig. 1, and Fig. 3 is a schematic plan view of a conventional example of an engine intake system; The plan view and FIG. 4 are side views taken along the line IV--■ in FIG. 3. 1... Cylinder head, 1a... Cylinder head side wall, 4... Intake port, 6...
...Combustion chamber side opening, 7...Cylinder head side wall side opening, 8...Straight portion, 8a...
Linear part side surface, 8b... Linear part bottom surface, 9...
...Curved portion, 13...Guide vane, Pl...
・・・Extension surface of the side surface of the straight part on the bending direction side, P2・
...The side surface of the linear part that is in contact with the periphery of the opening on the combustion chamber side (parallel to this, P3... An extension of the bottom surface of the linear part.

Claims (1)

[Scope of utility model registration request] The combustion chamber side opening of the intake port provided in the cylinder head and the cylinder head side wall side opening are offset in the horizontal direction, and the intake port is formed into a linear portion extending from the cylinder head side wall side opening at a substantially right angle to the cylinder head IP&. and a curved part that is continuous with this straight part, curves from the straight part in the tangential direction of the cylinder, and communicates with the combustion chamber side opening, so that the intake air-fuel mixture flows tangentially into the combustion chamber. In the intake system for an engine, the curved portion hangs down from the upper surface of the intake port to the extension surface of the bottom surface of the straight portion, and is in contact with the periphery of the opening on the combustion chamber side, as well as the side surface of the straight portion. An intake system for an engine, characterized in that a guide vane is provided within a range between a plane parallel to the curve and an extension plane of a side surface of the straight portion on the bending direction side, and extending in substantially the same direction as the bending direction.