JPH05106448A - Intake system of multicylinder internal combustion engine - Google Patents

Abstract

PURPOSE:To make the installation of an intake control valve easier and to seal a surge tank perfectly by providing the suction control valve to open and close according to the operation condition of an internal combustion engine to the partition wall of the surge tank, and providing sealing members to the cut surfaces of divided bodies. CONSTITUTION:The inner space in a surge tank 1 is divided into two, a first chamber 4a and a second chamber 4b, by a vertical partition wall 1a extending in the longitudinal direction. A hole 6 is provided in the partition wall 1a of the surge tank 1, and an intake control valve 7 to open and close the hole 6 is screwed up to a driving shaft 8. After the intake control valve 7 is installed on a second divided body 1'', a first and the second divided bodies 1' and 1'' are assembled. In this assembly, rubber packings 12a to 12c are adhered to the cut surfaces 10a to 10c of the second divided body 1''. The rubber packings 12a to 12c, and the cut surfaces 10a to 10c of the first divided body 1' are connected in the same way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake system for a multi-cylinder internal combustion engine.

[0002]

2. Description of the Related Art An internal space of a surge tank whose one end face is connected to an air cleaner through an intake duct is divided into two by a partition wall extending in the direction of the one end face and provided with an intake control valve. An intake device for a multi-cylinder internal combustion engine is known in which a first cylinder group is connected to the internal space and a second cylinder group is connected to the other internal space.

In this intake system, when the internal combustion engine is operating at a low speed, the intake control valve is fully closed to make the equivalent intake pipe length of each cylinder relatively long just before the intake duct. By fully opening the intake control valve to make the equivalent intake pipe length relatively short until just before the surge tank, a good inertia supercharging effect is obtained during both operations, and the charging efficiency is increased. It is designed to obtain high torque.

Upon installation, the intake control valve is inserted into a partition wall hole that is closed, is manually pressed from one side of the partition wall, and is screwed to the drive shaft from the other side by a tool such as a screwdriver. Such mounting work is very difficult in the surge tank. In order to solve this problem, in Japanese Utility Model Laid-Open No. 62-88832, an opening is provided on the other end surface of the surge tank opposite to the one end surface to which the intake duct is connected, and a partition wall in the surge tank is provided. A surge control is provided for an intake control valve holder that has a U-shaped notch around the opening, is fitted in the notch, and has a wall portion to which the intake control valve is attached and a flange portion that seals the opening. What is provided separately from the tank is described.

According to this intake system, after the intake control valve is attached to the intake control valve holder, the intake control valve holder can be assembled to the surge tank with bolts or the like using its flange portion. When mounting the valve, the wall portion of the intake control valve holder to which it is mounted is completely exposed on both sides, so this mounting operation can be facilitated.

[0006]

In the above intake device, the intake control valve holder is provided separately from the surge tank in order to facilitate the installation work of the intake control valve.
A joint portion is formed between the holder and the notch of the surge tank and the partition wall, and a rubber packing is used to make the portion airtight.

The rubber packing is normally installed between both members and is compressed by appropriately tightening both members to ensure good airtightness. Regarding the joint between the flange part of the intake control valve holder and the surge tank, there is no problem with the airtightness because the rubber packing is used in this way, but the wall part of the intake control valve holder and the bulkhead of the surge tank are Regarding the joint with the notch, there is a part where the rubber packing must be compressed in a direction substantially orthogonal to the tightening direction of the holder, and this compression causes the wall part of the intake control valve holder to It is intended to be done by inserting it into a notch in the septum.

The compression of such a rubber packing is brought about when the insertion of the wall portion into the notch is started, and in particular, the rubber packing of this portion has a considerable friction until the insertion is completed. Force acts continuously. Therefore, the rubber packing in this portion is stretched in the longitudinal direction by this frictional force and loses a predetermined thickness and hardness, so that good airtightness cannot be guaranteed.

As a result, even if the intake control valve is fully closed, the internal space of the surge tank is not completely divided into two parts, and the desired torque cannot be obtained because the inertia supercharging effect is reduced. Also, this leakage causes a problem such as generation of airflow noise.

Therefore, an object of the present invention is to facilitate the attachment of the intake control valve to the bulkhead of the surge tank, and
An object of the present invention is to provide an intake system for a multi-cylinder internal combustion engine that can completely seal the sealed portion of a surge tank.

[0011]

In order to achieve the above object, in the intake system for a multi-cylinder internal combustion engine according to the present invention, the internal space of the surge tank is formed by a partition wall extending in the longitudinal direction of the surge tank. Chamber and a second chamber, a first cylinder group is connected to the first chamber, and a second cylinder group is connected to the second chamber, and the surge tank has a longitudinal center of the surge tank. A first cutting surface that is substantially parallel to the line and is substantially perpendicular to the partition wall and that cuts the partition wall, and a second cutting surface that is substantially parallel to the first cutting surface and that cuts the outer wall of the surge tank in the substantially thickness direction. The cutting surface and a third cutting surface that is substantially parallel to the partition wall and cuts the outer wall in the substantially thickness direction are divided into a large first divided body and a small second divided body. Opening and closing control is performed on the bulkhead according to the operating state of the internal combustion engine. Intake control valve is provided that the first
The divided body and the second divided body are characterized in that a seal member is provided on each of the cut surfaces and are assembled by a bolt or the like in a direction of joining at least the second cut surface and the third cut surface. .

[0012]

In the intake system for a multi-cylinder internal combustion engine described above, the surge tank is divided into a first divided body and a second divided body, and the partition wall of the second divided body to which the intake control valve is attached has a third cut surface. Since one side is almost completely exposed by and the hand can easily reach from the opening formed by the second cut surface to the back side, the work of installing the intake control valve was inserted into the hole for the intake control valve. This can be easily performed by manually pressing the intake control valve from the back side of the partition wall and screwing it from the exposed side to the drive shaft with a tool such as a screwdriver.

On the other hand, the second divided body to which the intake control valve is attached and the first divided body are assembled on the respective cut surfaces with the seal member interposed therebetween, but the first cut surface and the second cut surface are substantially parallel to each other. Since the third cutting surface forms an angle of about 90 ° with respect to them, at the time of this assembly, the sealing member fixed to each cutting surface of one of the divided bodies and each of the other divided bodies are The cutting surface is fitted without frictional force, and the second
Since the seal members are assembled by bolts or the like in the direction of joining the cut surface and the third cut surface, the respective seal members are extended in the longitudinal direction and do not lose a predetermined thickness and hardness, It is compressed, and the inside and outside of the surge tank and the space between the first chamber and the second chamber are completely sealed.

[0014]

1 shows an embodiment of an intake system for a multi-cylinder internal combustion engine according to the present invention. This figure shows a case where the internal combustion engine has six cylinders, and the surge tank 1 has six intake pipes 2a, 2b, 2c, 2d, 2e, 2f leading to each cylinder, and an air cleaner (Fig. Two intake ducts 3a and 3b leading to (not shown) are connected.

FIG. 2 is an exploded view of the intake device shown in FIG. 1, and FIG. 3 is a sectional view perpendicular to the longitudinal direction of the surge tank 1. As shown in these figures, the internal space of the surge tank 1 is divided into a first chamber 4a and a second chamber 4b by a vertical partition wall 1a extending in the longitudinal direction. The intake pipes 2a, 2b, 2c communicating with the first chamber are for the first cylinder group in which the intake strokes do not overlap each other.
d, 2e and 2f are for the same second cylinder group.
The two intake ducts 3a and 3b communicate with the first chamber and the second chamber, respectively, and are connected to a throttle body (not shown) having a throttle valve by a flange 5 fixed to the other side.

A hole 6 is provided in the partition wall 1a of the surge tank 1, and an intake control valve 7 capable of opening and closing the hole 6 is screwed to a drive shaft 8. The drive shaft 8 is connected to a diaphragm actuator 9 and is operated so that the intake control valve 7 is fully opened during high speed operation of the internal combustion engine and is fully closed during low speed operation.

Each intake pipe 2a, 2b, 2c, 2d, 2e,
2f, the first chamber 4a and the second chamber 4b, and each intake duct 3
Since a and 3b are formed so that the cross-sectional area does not change so much, the intake control valve 7 is driven as described above, so that when the internal combustion engine is operating at low speed, the equivalent intake pipe length is It becomes relatively long from (not shown) to just before the flange 5, and during high speed operation, the intake control valve 7 is fully opened and the first chamber 4a and the second chamber 4b in the surge tank 1 are communicated with each other. Therefore, the equivalent intake pipe length is relatively short from the intake valve to immediately before the surge tank 1, and a good inertia supercharging effect can be obtained during both operations, and high torque can be obtained by increasing the charging efficiency. You can

The surge tank 1 of this embodiment has a first cutting surface 10a for cutting the partition wall 1a which is substantially parallel to the longitudinal centerline of the surge tank 1 and is substantially perpendicular to the partition wall 1a, and a first cutting surface 10a. A second cutting surface 10b that is substantially parallel and cuts the outer wall 1b of the surge tank 1 in a substantially thickness direction, and a partition wall 1a.
Is divided into a large first divided body 1'and a small second divided body 1 "by a third cutting surface 10c that is substantially parallel to and cuts the outer wall 1b in the substantially thickness direction, and the intake control described above is also performed. The valve 7 is provided on the partition wall 1 ″ a of the second divided body 1 ″.

Accordingly, the work of mounting the intake control valve 7 is performed by mounting the drive shaft 8 and the diaphragm actuator 9 on the second divided body 1 ", and then installing the intake control valve 7 on the partition wall 1" a of the second divided body 1 ". The second divided body 1 ″ by inserting it into the hole 6 of
From the opening 11 formed by the second cut surface of the second divided body 1 ″, and use a tool such as a screwdriver from one side of the partition wall 1 ″ a completely exposed by the third cut surface of the second divided body 1 ″. This is easy because it can be screwed to the drive shaft 8.

The intake control valve 7 is thus attached to the second divided body 1 ".
After the attachment, the second divided body 1 ″ and the first divided body 1 ′ are assembled. At the time of this assembly, a sealing member is attached to each of the cut surfaces 10a, 10b, 10c of the second divided body 1 ″. The rubber packings 12a, 12b, 12c are adhered,
These rubber packings 12a, 12b, 12c are aligned with the cut surfaces 10a, 10b, 10c of the first divided body 1 '. At this time, the first cut surface 1a and the second cut surface 10
The angle formed by b and the first cut surface 10c is about 90 °.
Therefore, the rubber packings 12a, 12b, 12c
Are the cut surfaces 10a, 10b, 10c of the first divided body 1 '.
As a result, no frictional force acts, which prevents it from being stretched to reduce its thickness or change its hardness.

The surge tank 1 has a plurality of three cross sections shown in FIG. (A) is a cross section having a bolt 13a for joining the partition walls 1'a and 1 "a cut by the first cut surface 10a, and (B) is an outer wall 1'cut by the second cut surface 10b. a cross section having bolts 13b for joining b and 1 "b, (C) shows a third cut surface 10
It is a cross section having bolts 13c for joining outer walls 1'b and 1 "b cut by c.

These three types of bolts 13a, 13b, 1
Due to 3c, the rubber packings 12a, 12b, 12c are appropriately compressed to ensure good airtightness and the first divided body 1'and the second divided body 1 "are securely assembled.

If the first cut surface 10a and the second cut surface 10b are the same as in this embodiment, these seal surfaces can be processed at the same time, and the processing time can be shortened.

Although this embodiment shows the case of a surge tank having a circular cross section, it is obvious that the present invention can be applied to surge tanks having a rectangular or other polygonal cross section.

The bolts 13a and 13b are tightened in the same direction, and it is possible to omit either type of bolt.

The air intake system of this embodiment, when mounted on a vehicle,
If the flange 5 is on the right side when viewed from the front of the vehicle, the cut surface of the surge tank 1 and the assembly bolts 13a, 13b, 13
c does not enter the field of view and is very preferable in appearance.

[0027]

As described above, according to the intake system for a multi-cylinder internal combustion engine of the present invention, the intake control valve is attached to the partition of the surge tank so that the surge tank is divided into the first divided body and the second divided body. It can be easily performed by dividing the body into two parts, and the assembly of the second divided body and the first divided body after attachment of the intake control valve can be performed without abnormally deforming the seal member provided on each cut surface, It is possible to surely perform each sealing member with a bolt in a direction of appropriately compressing, and it is possible to prevent the inertia supercharging effect from being reduced and the occurrence of air flow noise due to defective sealing.

[Brief description of drawings]

FIG. 1 is a perspective view of an intake system for a multi-cylinder internal combustion engine according to the present invention.

FIG. 2 is an exploded view of the intake device of FIG.

3A and 3B are three cross-sectional views in which the position of the surge tank of the intake device of FIG. 1 in the longitudinal direction is different, and FIG.
(B) shows a second cross section, and (C) shows a third cross section.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Surge tank 1 '... 1st division body 1 "... 2nd division body 1a, 1'a, 1'b ... Partition wall 1b, 1'b, 1" b ... Outer wall 4a ... 1st chamber 4b ... 2nd chamber 7 ... Intake control valve 10a ... 1st cutting surface 10b ... 2nd cutting surface 10c ... 3rd cutting surface 12a, 12b, 12c ... Rubber packing 13a, 13b, 13c ... Bolt

Claims (1)

[Claims] 1. A first chamber and a second chamber, wherein an internal space of the surge tank is formed by a partition wall extending in a longitudinal direction of the surge tank.
A first cylinder group is connected to the first chamber and a second cylinder group is connected to the second chamber, and the surge tank is substantially parallel to the longitudinal centerline of the surge tank. A first cutting surface that cuts the partition wall substantially perpendicular to the partition wall, and a second cutting surface that is substantially parallel to the first cutting surface and cuts the outer wall of the surge tank substantially in the thickness direction; Third, which is substantially parallel to the partition wall and cuts the outer wall substantially in the thickness direction
The cut surface of the, by the large first divided body and the small second
An intake control valve, which is divided into two divided bodies and whose opening and closing is controlled according to the operating state of the internal combustion engine, is provided in the partition wall of the second divided body, and the first divided body and the second divided body are An intake system for a multi-cylinder internal combustion engine, wherein a seal member is provided on each cut surface and is assembled by a bolt or the like in a direction of joining at least the second cut surface and the third cut surface.