JPH0233857B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intake port for an internal combustion engine, and more particularly to an intake port for an internal combustion engine that is composed of a helical-shaped cavity and that forms a swirl due to the shape.

A cylinder head 1 as shown in FIG. 1 has conventionally been attached to the upper part of a cylinder block constituting an internal combustion engine, and the cylinder head 1 closes off the upper part of the cylinder. An intake port 2 is formed in this cylinder head 1. The intake port 2 is composed of a helical-shaped cavity, and this helical shape forms an intake air vortex, that is, a swirl inside the cylinder, thereby achieving good combustion.

In such a conventional intake port, the first
As shown in the figure and FIG. 2, depending on the shape, in addition to the main stream or first stream 3, a second stream 4 and a third stream 5 were formed, respectively. When the intake valve is opened, these streams 3, 4, and 5 are guided into the cylinder as shown in FIG. 2 in order to achieve good combustion within the cylinder. However, the conventional swirl mainly consisting of three flows 3, 4, and 5 has the drawback that there is little turbulence in the intake air within the cylinder, and a region where no intake air flow exists is formed within the cylinder. Ta.

The present invention has been made in view of these problems, and provides an intake port for an internal combustion engine in which the turbulence of intake air within a cylinder is further increased and the region where no flow exists is further reduced. The purpose is to

The present invention will be explained below with reference to an illustrated embodiment.
FIG. 3 shows a cylinder head 10 of an internal combustion engine according to this embodiment, and this cylinder head 10 is fixed to the upper part of a cylinder block (not shown). An intake port 11 is formed in this cylinder head 10. The port 11 is formed from a helical-shaped cavity, and its inlet side communicates with an opening 12 in the side surface of the cylinder head 10. An intake manifold (not shown) is connected to this opening 12, and intake air is introduced into the intake port 11 through this manifold. The intake port 11 has an introduction part 13 on the inlet side and a helical part 1 on the tip side.
4, and a circular portion 15 formed at the center of the helical portion 14. These parts 1
Intake ports 11 with 3, 14 and 15, respectively.
As a result, as shown in FIG. 4, in addition to the main flow 16 or the first flow, three intake flows, a second flow 17 and a third flow 18, are formed as in the conventional case. .

Further, in the intake port 11 according to this embodiment, a recess 19 is formed on the outer peripheral side of the helical portion 14. The entrance side of the recess 19 is formed into a gentle curve that is continuous with the wall surface of the helical portion 14, whereas the terminal end 20 of the recess 19 is formed into an inclined surface. The main stream 1
A substream 21 is formed which branches off from 6.

In this way, according to the intake port 11 according to this embodiment, there are three flows 16, 17, 18 similar to the conventional one.
In addition, it becomes possible to form a substream 21 of intake air, and these four flows are as shown in FIG.
When the intake valve is opened, the intake air is introduced into the cylinder through the intake port 11. Since the secondary flow 21 flows into the cylinder in addition to the conventional flow, turbulence within the cylinder increases. This results in better mixing of fuel and air, and also reduces the no-flow area within the cylinder. Therefore, according to this embodiment, it is possible to achieve a more ideal combustion explosion within the cylinder. In fact, in an engine equipped with the intake port 11 according to this embodiment, it has been confirmed that when the piston descends from top dead center by a length corresponding to its bore diameter, the area where no flow exists becomes extremely small. ing.

As described above, the present invention forms a recess in a part of the outer peripheral wall for forming the mainstream of the swirl of the intake port, and the end of the recess is an inclined surface. This invention relates to an intake port configured to form a side flow that is separated from the main flow by the flow. Therefore, according to the present invention, by slightly changing the shape of the intake port, especially on the outer circumferential side, it is possible to increase the number of divisions of the intake air flow and increase the turbulence of the intake air within the cylinder. The area in which no flow exists can be reduced.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of a cylinder head equipped with a conventional intake port, FIG. 2 is a cross-sectional view of the same intake port, and FIG. 3 is a cylinder head equipped with an intake port according to an embodiment of the present invention. FIG. 4 is a partially cutaway perspective view of the cylinder head, and FIG. 4 is a cross-sectional view of the intake port. In addition, in the symbols used in the drawings, 10...cinder head, 11...intake port, 16...mainstream (first
flow), 19... recess, 20... terminal end (slanted surface), 21...
It's a side stream.

Claims (1)

[Claims] 1. In an intake port that is composed of a hollow shape and that forms a swirl depending on the shape, a recess is formed in a part of the outer peripheral wall for forming the main flow of the swirl of the port, and the recess is An intake port for an internal combustion engine, characterized in that the terminal end thereof is an inclined surface, and the terminal end forms a subflow separated from the main flow of the swirl by a recess formed by the inclined surface.