JPS63208616A - Air-intake device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To average the strength of intake-air swirls in all cylinders by providing a guide portion which makes the intake-air flow in a main line drift, on a branch line where a bend of intake-air flow from the main line to branch lines in an intake-air manifold becomes the same as the turning direction E of an intake-air swirl. CONSTITUTION:An intake-air manifold C which distributes intake-air to plural cylinders A1-A4 in an internal-combustion engine is composed of a main line C7 extending in the direction of a row of cylinders and plural branch lines C1-C4 which branch from the main line C7 to respective cylinders A1-A4. An intake-air entrance C8 to which an intake-air passage D is connected is arranged between the second and third respective branch lines C2, C3 in the main line C7. In the above construction, on the opening portion of the second branch line C2 where a bend of intake-air flow from the main line C7 to the second and third respective branch lines C2, C3 becomes the same as the turning direction E of an intake-air swirl, a guide portion C2a which makes the intake- air flow in the main line C7 drift with respect to the second branch line C2 is formed integrally.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an intake device for distributing intake air to each cylinder in an in-line multi-cylinder internal combustion engine in which a plurality of cylinders are arranged in a row. It is something.

[Conventional technology and its problems]

In order to improve combustion within the cylinders of an internal combustion engine, configuring the intake ports in the cylinders as swirl ports so that intake swirl occurs within the cylinders is known, for example, as disclosed in U.S. Pat.
It is described in Publication No. 546, etc.

It's well known.

When this intake swirl system is applied to a sub-type multi-cylinder internal combustion engine (for example, a 4-cylinder internal combustion engine) in which a plurality of cylinders are arranged in a line, each cylinder A1 to A1 as shown in FIG.
From the viewpoint of design, etc., the direction of rotation of the intake swirl by the intake ports 81 to B4 in A4 is as shown by arrow E.
It is customary to set each of the first cylinder A1, the second cylinder A2, the third cylinder A3, and the fourth cylinder A4 in the same direction (for example, clockwise in plan view).

On the other hand, as an intake manifold for distributing intake air from the air cleaner to each cylinder in a multi-cylinder internal combustion engine,
As shown in FIG. 4, the main pipe C7 is composed of a main pipe C7 extending in the direction of the cylinder row, and branch pipes 01 to C4 branching from the main pipe C7 at locations corresponding to the cylinders A1 to A4. It is common to use an intake manifold C having an intake port C8 from the air cleaner between the branch pipes in the cylinders A1 to A4. If B4 is applied to a swirl boat configured with the same turning direction E as described above, the following problems will occur.

That is, the bending direction of the intake flow from the main pipe C7 to the first cylinder technical pipe C1 and the second cylinder technical pipe C2 is as follows.
Arrow F1. The direction of intake swirl E as shown by F2
Therefore, the strength of the intake swirl in the first cylinder A1 and the second cylinder A2 tends to be enhanced by the curves of the arrows Fl and F2, but the main pipe C7
The bending direction of the intake air flow from the direction toward the third cylinder pipe C3 and the fourth cylinder pipe C4 is indicated by the arrow F3. As shown by F4, the intake swirl direction is opposite to the swirling direction E, so the strength of the intake swirl in the first cylinder A1 and the second cylinder A2 is as indicated by the arrow F3. It tends to be weakened by the bending of F4.

Therefore, the strength of the intake swirl in each cylinder A1 to A4 is such that the bend from the main pipe C7 to each cylinder is the same as the turning direction of the intake swirl in the first cylinder A1 and the first cylinder A2.
and the third cylinder A3 and the fourth cylinder A4, where the bend from the main pipe C7 to each cylinder is opposite to the direction of intake swirl, and the combustion state in each cylinder is uneven. This results in a decrease in the output of the internal combustion engine, an increase in vibration, and a deterioration in drivability.

The present invention aims to solve this problem.

[Means for solving problems]

For this reason, the present invention configures the intake ports of each of the cylinders arranged in a row to be swirl ports that generate intake swirl in the same direction within each cylinder, while distributing the intake air from the air cleaner to each of the cylinders. The intake manifold for the purpose of In the intake device, in which an intake inlet from the air cleaner is provided in a portion of the main pipe, the bending of the intake flow from the main pipe to the branch pipe, excluding the branch pipes at both ends of the main pipe, causes the intake swirl. At the location of the branch pipe that is the same as the turning direction of This configuration includes a guide section that has a shape.

〔Example〕

An embodiment of the present invention will be described below with reference to a drawing (Fig. 1). In this drawing, the symbol A indicates a first cylinder A1, a second cylinder A2, a third cylinder A3, and a fourth cylinder A4 arranged in a line. The figure shows a 4-cylinder internal combustion engine of the same size, each cylinder A1 to A4.
The intake ports B1 to B4 are configured in a swirl boat so that the intake air from each intake port swirls clockwise, for example, as shown by an arrow E in each cylinder.

Reference numeral C indicates an intake manifold for distributing intake air from an air cleaner (not shown) to each of the cylinders A1-A4, and the intake manifold C includes a main pipe C7 extending in the direction of the cylinder row. It is composed of branch pipes 01 to C4 that branch from the main pipe C7 at the locations of each cylinder, and the second cylinder technical pipe C2 and the third cylinder technical pipe C3 in the main pipe C7. An intake port C8 to which an intake passage from the air cleaner is connected is provided between the two.

Then, among the branch pipes Cl-C4, the portion of the second cylinder pipe C2, that is, the first cylinder pipe C1 and the fourth cylinder branch pipe C4 at both ends of the main pipe C7 are Among the second cylinder technical pipe C2 and the third cylinder technical pipe C3 excluding the second cylinder technical pipe C2 and the third cylinder technical pipe C3, the bending of the intake flow from the main pipe C7 to these two branch pipes C2 and C3 is the same as the turning direction E of the intake swirl. At the location of the second cylinder technical conduit C2, the main conduit C2 is located at the opening of the second cylinder technical conduit C2 into the main conduit C7.
A guide portion C2a that deflects and biases the intake air flow in the second cylinder pipe C2 toward the second cylinder pipe C2 is integrally formed.

With this configuration, from the intake population C8 to the first cylinder A1
And the intake flow toward the second cylinder A2 is directed to the guide portion C.
2a, the flow is deflected away from the second cylinder pipe C2 as shown by arrow G, and then the flow is diverted away from the second cylinder pipe C2 as shown by arrow G.
The intake air flows into the second cylinder pipe C2 and the first cylinder pipe C1 as shown in FIG.
The strength of the intake swirl in the direction of arrow E in the first and second cylinders A2 is different from that in the other cylinders, that is, the third cylinder A3 and the fourth cylinder.
This approaches the strength of the intake swirl in the direction of arrow E in cylinder A4.

In this case, experiments have shown that it is more effective to provide the second cylinder conduit C2 with an inclined surface C2b on the opposite side of the guide portion C2a. If the intake swirl in the first cylinder A becomes stronger, a bulge C1a may be provided at the bend from the main pipe C7 to the first cylinder technical pipe C1, as shown by the two-dot chain line. , was effective in reducing intake swirl in the first cylinder AI.

FIG. 2 shows an example in which the engine is applied to a six-cylinder internal combustion engine. As in the case of a four-cylinder internal combustion engine, the tendency is stronger in the first cylinder A1, the second cylinder A2, and the third cylinder A3. Therefore, among the branch pipes C1 to C6 in the intake manifold C, the second cylinder Road C2 and 3rd
The first cylinder technical pipe C1 and the sixth cylinder technical pipe C6 at both ends of the cylinder pipe C3, that is, the main pipe C7.
Among the branch pipes 02 to C5 excluding the above, the second cylinder technical pipe in which the bend of the intake flow from the main pipe C7 to each of these branch pipes C2 to C5 is the same as the turning direction E of the intake swirl in the cylinder. At the location of the C2 and third cylinder technical conduit C3, there is an opening in the main conduit C5 of the second cylinder technical conduit C2 and the third cylinder technical conduit C3 into the main conduit C5. Guide portions C2a and C3 that deflect and bias the intake flow toward the second cylinder technical conduit C2 and the third cylinder technical conduit C3.
In this case, the slopes C2b and C3b may be provided for the second cylinder conduit C2 and the third cylinder conduit C3, or the main conduit C7 It is more effective to provide a bulging portion C9 as shown by a two-dot chain line at the bending portion from the pipe C1 to the first cylinder pipe C1.

It goes without saying that the present invention can also be similarly applied to a three-cylinder internal combustion engine as shown in FIG.

[Action/effect of the invention]

As described above, according to the present invention, the bending direction from the main pipe to the branch pipe leading to the intake manifold is the same as the direction of intake swirl in each cylinder, so that the strength of the intake swirl can be increased in a specific cylinder. This can be prevented by deflecting and biasing the intake flow using a guide section installed in the main pipe of the intake manifold, and the strength of the intake swirl in all cylinders can be averaged, so the combustion state in each cylinder can be prevented from being uneven. This has the effect of reliably preventing a decrease in output, an increase in vibration, and a deterioration in drivability due to such changes.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway plan view showing a first embodiment of the present invention, FIG. 2 is a partially cutaway plan view showing a second embodiment of the present invention, and FIG.
The figure is a partially cutaway plan view showing a second embodiment of the present invention, and FIG. 4 is a partially cutaway plan view showing a conventional one. A...Internal combustion engine leap, A1~A6...Cylinder, B1~
B6... Intake port, C... Intake manifold, C1-C6... Branch pipe line, C7... Main pipe line, C
8...Intake inlet, C2a, C3a...Guide part. −de−ee

Claims (1)

[Claims] (1) In order to configure the intake ports of each of the cylinders arranged in a row into swirl ports that generate intake swirl in the same direction within each cylinder, and to distribute the intake air from the air cleaner to each of the cylinders. The intake manifold is composed of a main pipe extending in the direction of the cylinder row and a branch pipe branching from the main pipe at a location of each cylinder, and a portion between the branch pipes in the main pipe of the intake manifold is ,
In the intake device provided with an intake inlet from the air cleaner, among the branch pipes excluding the branch pipes at both ends of the main pipe, the bending of the intake flow from the main pipe to the branch pipe is in the turning direction of the intake swirl. At the location of the branch pipe that is the same as that of the main pipe, a guide part is installed at the opening of the branch pipe into the main pipe to divert the intake flow in the main pipe to the branch pipe. An intake system for an internal combustion engine, characterized in that it is provided with.