JPH10122069A - Inertia supercharging type intake system in multi-cylinder internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve intake distribution capability from an air cleaner by forming the opening edges of respective intake lines toward the inside of a surge tank into an arc shape and making the radius of the arc surface small for an intake line which overlaps with an intake inlet among the respective intake pipes, and large for an intake pipe which does not overlap. SOLUTION: The intake air flowing into a surge tank 3 from an intake inlet 9a is distributed to intake lines 4, 5 and 6 led to respective cylinders in the surge tank 3. The radii of arc surfaces 4a', 5a' and 6a' of an opening edge in the connected parts of intake lines 4, 5 and 6 to the surge tank 3 parts 4a, 5a and 6a are formed into a small R2 for the second cylinder intake line 5 which overlaps with the intake inlet 9a among the intake lines 4, 5 and 6, and a large R1 for the first and third cylinder intake lines 4, 6 which do not overlap. It is thus possible to make flow resistance large for the second cylinder intake line 5, and small for the first and third cylinder lines 4, 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a multi-cylinder internal combustion engine in which a long pipe-shaped intake pipe independently connected to each cylinder is connected to a surge tank downstream of an air cleaner. The present invention relates to an intake device in which intake air is supercharged using an inertial effect.

[0002]

2. Description of the Related Art In general, this type of inertia supercharging type intake device for a multi-cylinder internal combustion engine has a pipe shape in which each intake line from one surge tank to each cylinder downstream of an air cleaner is formed. By making the length considerably longer, an inertia effect can be obtained. In addition, by making the lengths of the intake pipes substantially equal to each other, inertia supercharging for each cylinder can be achieved. It is necessary to reduce the variation of the data.

In order to satisfy this condition, Japanese Patent Application Laid-Open No. 4-76263 discloses an inertia supercharging type intake device for a multi-cylinder internal combustion engine. It is proposed that a surge tank provided with a surge tank is disposed at a longitudinal side of the internal combustion engine in a plan view, and a long pipe-shaped intake pipe from each of the cylinders is connected to the other end face of the surge tank. .

[0004]

However, this conventional inertia supercharging type intake device has an intake inlet for introducing intake air from an air cleaner into the surge tank at one end face of the surge tank, while a surge inlet is provided. At the other end surface of the tank, an intake pipe to each cylinder is connected such that an inlet to each of the intake pipes opens into the surge tank, so that an intake inlet at one end of the surge tank is provided. However, when viewed from the axial direction, when one of the intake pipes connected to the other end face overlaps with one of the intake pipes, the intake air flowing into the surge tank from the intake introduction port is subjected to the intake introduction. Since a large amount flows into the intake pipe overlapping the mouth, and the amount of flow into the intake pipe not overlapping the intake port tends to decrease,
The intake air from the air cleaner cannot be distributed equally to the pipe-shaped intake pipes to the respective cylinders. In other words, the distribution of the intake air to the respective intake pipes varies, and torque fluctuation between the respective cylinders occurs. Had the problem of becoming larger.

[0005] It is a technical object of the present invention to provide an inertia supercharging type intake device which solves this problem.

[0006]

In order to achieve the above technical object, the present invention provides a method of disposing a surge tank downstream of an air cleaner on a longitudinal side of an internal combustion engine in a plan view. In the intake device, an intake port from the air cleaner is provided at an end face, and each of the pipe-shaped intake pipes to each cylinder in the internal combustion engine is connected to the other end face of the surge tank. The opening edge of the passage into the surge tank is formed in an arcuate surface, and the radius of this arcuate surface is small in the intake line of each intake line overlapping the intake port,
The size is increased in an intake pipe that does not overlap with the intake port. ".

[0007]

The flow of the intake air in the surge tank flowing into each intake pipe by forming the opening edge of the pipe-shaped intake pipe leading to each cylinder into the surge tank into an arcuate surface. Resistance can be reduced. The flow resistance in this case is inversely proportional to the radius of the arc surface, such that the flow resistance decreases as the radius of the arc surface at the opening edge increases, and increases as the radius of the arc surface decreases.

Therefore, as described above, the radius of the arc surface of the opening edge of each intake pipe is small in the intake pipe overlapping the intake port of each intake pipe, and By increasing the size of the intake pipe that does not overlap the mouth, the amount of intake air flowing from the surge tank to each intake pipe increases in the intake pipe overlapping the intake port to the surge tank. The tendency can be reduced in the intake pipe which does not overlap the intake port to the tank.

Therefore, according to the present invention, in the inertia supercharging type intake device, the distribution property of distributing the intake air from the air cleaner equally to the pipe-shaped intake pipe to each cylinder in the surge tank is surely improved. This has the effect of greatly reducing torque fluctuation between the cylinders.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. In this figure, reference numeral 1 denotes an internal combustion engine having three cylinders of a first cylinder A1, a second cylinder A2, and a third cylinder A3, and reference numeral 2 denotes an intake device for inertia supercharging of the internal combustion engine 1.

The intake device 2 connects one surge tank 3 disposed at one end of a longitudinal side surface 1a of the internal combustion engine 1 in plan view to the surge tank 3 and the cylinders A1, A2, A3. And three relatively long pipe-shaped intake pipes 4, 5 and 6 are provided. The tip of each of the intake pipes 4, 5 and 6 in the intake device 2 is formed on the longitudinal side surface 1a of the internal combustion engine 1. On the other hand, it is integrally joined to a synthetic resin flange portion 7 detachably fastened by a plurality of bolts by ultrasonic bonding or the like.

The surge tank 3 is formed by bonding a flat synthetic resin bottom plate 8 extending at right angles to the longitudinal side surface 1a of the internal combustion engine 1 and a synthetic resin box 9 by ultrasonic bonding or the like. The box 9 is connected to a portion of the box 9 opposite to the bottom plate 8 with an intake line 10 from an air cleaner (not shown) or a throttle valve. An intake inlet 9a to which a built-in throttle body is attached is formed.

Each of the pipe-shaped intake pipes 4, 5 and 6 is set to have substantially the same length, and is curved so as to be substantially perpendicular to the bottom plate 8 of the surge tank 3, and then the bottom plate 8 To be connected together. In this case, of the intake pipes 4, 5, and 6, a connection portion 4a of the intake pipe 4 to the bottom plate 8 which reaches the first cylinder A1 near one end of the internal combustion engine 1; 6, a connecting portion 5a of the intake pipe 5 from the one end of the internal combustion engine 1 to the second cylinder A2 which is farthest from the bottom plate 8;
A connecting portion 6 of the intake pipe 6 to the bottom plate 8 that extends from one end of the internal combustion engine 1 to the third cylinder A3 farthest from the one end of the internal combustion engine 1
a is located at a position where the connecting portion 4a of the intake pipe 4 for the first cylinder A1 is the lowest among the connecting portions 4a, 5a, 6a, and the connecting portion 5a of the intake pipe 5 for the second cylinder A2 is The third cylinder A is located at a position higher than the connection portion 4a.
The connection portions 6a of the three intake pipes 6 are arranged in substantially a single row along the up and down direction so as to be located at a position higher than the connection portions 5a.

The connecting portion 5a of the intake pipe 5 for the second cylinder A2 among the connecting portions 4a, 5a, 6a is connected to the axis 9 of the intake inlet 9a at one end face of the surge tank 3.
a ′, in other words, the intake port 9
When viewed from the direction of the axis 9a 'of FIG. And, each said intake pipe 4,
The edges of the opening of the surge tank 3 into the bottom plate 8 at the connection portions 4a, 5a, and 6a of the fifth and sixth portions are respectively connected to the arc-shaped surfaces 4a 'and 5a.
a ', 6a', these arc surfaces 4
a ', 5a', and 6a ', the radius of each intake line 4, 5, 6
Connecting portions 4a, 6 of the first cylinder intake pipe 4 and the third cylinder intake pipe 6 which do not overlap with the intake port 9a.
As shown in FIGS. 6 and 8, at the arc surfaces 4a 'and 6a' in FIG.
As shown in FIG. 6 and FIG. 9, at the arc surface 5 a ′ at the connection portion 5 a of the second cylinder intake pipe 5 that is located on the axis 9 a ′ of a and overlaps with the intake port 9 a, R
As described above, R2 is made smaller than R1.

In this configuration, the intake air flowing into the surge tank 3 from the intake introduction port 9a to which the intake introduction pipe 10 is connected is supplied to each of the cylinders A1, A in the surge tank 3.
2, A3 are distributed to intake lines 4, 5, and 6. In this case, the connection portion 5a of the second intake line 5 of the intake lines 4, 5, 6 to the surge tank 3 is located on the axis 9a 'of the intake port 9a. Due to the overlap with the intake port 9a, a large amount of intake air flowing into the surge tank 3 from the intake port 9a flows into the second cylinder intake pipe 5 overlapping the intake port 9a, The other flows into the first cylinder intake pipe 4 and the third cylinder intake pipe 6 tend to be smaller than the flow into the second cylinder intake pipe 5. .

On the other hand, according to the present invention, as described above, the arcuate surfaces 4a ', 5 of the opening edges of the connection portions 4a, 5a, 6a of the intake pipes 4, 5, 6 to the surge tank 3 are provided.
The radius of a ', 6a' is smaller than R2 in the intake pipe 5 for the second cylinder which overlaps with the intake port 9a among the intake pipes 4, 5, 6, and is smaller than R2. On the other hand, the other intake pipes 4 for the first cylinder and the intake pipe 6 for the third cylinder, which are not overlapped, are configured to be larger than R1.

As a result, the flow resistance when flowing from the surge tank 3 to each of the intake pipes 4, 5, 6 is large in the second cylinder intake pipe 5, and is large in the other first cylinder intake pipes 4. In addition, since it is possible to make the intake pipes 6 for the third cylinder smaller, the amount of intake air to each of the intake pipes 4, 5, and 6 increases in the intake pipe 5 for the second cylinder, and the other first cylinders In the intake manifold 4 for the third cylinder and the intake manifold 6 for the third cylinder, the tendency can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a right side view of FIG. 1;

FIG. 4 is an enlarged sectional view taken along line IV-IV of FIG. 2;

FIG. 5 is an enlarged sectional view taken along line VV of FIG. 1;

FIG. 6 is an enlarged sectional view of FIG. 4;

FIG. 7 is a sectional view taken along the line VII-VII in FIG. 6;

8 is a sectional view taken along line VIII-VIII of FIG.

FIG. 9 is a sectional view taken along line IX-IX of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Internal combustion engine 1a Longitudinal side surface A1, A2, A3 Cylinder 2 Intake device 3 Surge tank 4,5,6 Intake line 4a, 5a, 6a Connection part 7 Flange part 8 Bottom plate 9 Box 9a Intake inlet port 10 Intake inlet line

Claims (1)

[Claims] 1. A surge tank downstream of an air cleaner is disposed at a longitudinal side portion of an internal combustion engine in a plan view. An intake port from the air cleaner is provided at one end of the surge tank. The other end surface of the intake device is formed by connecting each of the pipe-shaped intake pipes to each cylinder in the internal combustion engine. An opening edge of each of the intake pipes into the surge tank is formed in an arcuate surface. The radius of the arc surface is small in the intake pipes overlapping the intake port of each intake pipe, and is large in the intake pipes not overlapping the intake port. Inertia supercharged intake system in a multi-cylinder internal combustion engine.