JP3505254B2 - Exhaust manifold - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust manifold for discharging gas discharged from an engine to an exhaust pipe.

[0002]

2. Description of the Related Art Conventionally, most exhaust manifolds are made by die casting, but it is difficult to reduce the wall thickness, so that the following problems occur. That is, normally, an exhaust purification catalyst device is arranged downstream of the exhaust manifold, but since this catalyst reacts only when it reaches a predetermined temperature, immediately after the engine is started when the exhaust manifold is cold. In some cases, the exhaust gas did not reach the predetermined temperature, and exhaust gas could not be sufficiently purified. In this case, if the heat capacity of the exhaust manifold is small, the time required for the exhaust gas to reach the predetermined temperature is shortened. Therefore, the wall thickness of the exhaust manifold is as thin as possible (1 to 2.5 mm).
It was desired to do so.

From this point of view, instead of die casting, the exhaust manifold is divided into an upper case and a lower case by dividing the exhaust manifold into upper and lower parts, and these are thinly formed by press molding, and the exhaust manifold is welded to each other. It came to be developed. As such a conventional example, for example, there is an exhaust manifold described in JP-A-6-280557.

[0004]

However, in the exhaust manifold disclosed in Japanese Patent Laid-Open No. 6-280557, it is necessary to press-mold the upper case and the lower case separately, and to attach them to the cylinder head of the engine. Since the flange is required as a separate component, there is a problem that the number of components is large and the manufacturing cost cannot be reduced sufficiently. Further, since there is a step of welding the upper case, the lower case and the flange, the manufacturing process is long, and there is a problem in that the manufacturing cost cannot be reduced sufficiently from this point as well.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an exhaust manifold having a simple structure capable of sufficiently reducing the manufacturing cost.

[0006]

In order to solve the above problems, an exhaust manifold according to the present invention is attached to a downstream side of an engine and has a flange having a gas introduction port substantially at the center and a peripheral edge of the gas introduction port. A manifold body that is formed to have a substantially box-like shape, and has a gas outlet on the side facing the gas inlet, and the flange and the body are integrally formed , and , The above
In the vicinity of the gas inlet of the manifold body, one or a plurality of
A partition plate is provided, and the partition plate is the manifold book.
By partitioning the internal space of the body on the gas inlet side,
The plurality of small spaces are provided for each cylinder of the engine.
It is characterized by forming a plurality of small spaces facing the exhaust holes .

Here, the flange and the manifold body may be integrally formed by pressing a single metal plate .

[0008]

In the exhaust manifold of the present invention having the above structure, the gas discharged from the engine is collected in the manifold main body through the gas introduction port provided in the flange and discharged from the gas discharge port of the manifold main body. To be done. The discharged gas usually passes through an exhaust purification catalyst device arranged downstream of the exhaust manifold and is discharged to the outside through an exhaust pipe.

In the exhaust manifold of the present invention, the flange and the main body of the manifold are integrally formed, and the conventional structure composed of a total of three parts including the upper case, the lower case and the flange is composed of one part. ing. Therefore, the number of parts is reduced, the welding process is not required, and the manufacturing cost is significantly reduced.

Further, the flange and the manifold main body can be integrally formed, for example, by pressing a single metal plate. At this time, the thickness of the exhaust manifold is 1 to 2.5 if a metal plate having a predetermined thickness is used.
Since it can be adjusted to about mm, the heat capacity of the exhaust manifold can be set small, and the temperature of the catalyst of the exhaust purification catalyst device arranged downstream of the exhaust manifold can be raised or activated in a short time. .
As a result, the effect that the purification efficiency of the discharged gas can be increased can be obtained.

Further, one or a plurality of partition plates are provided in the vicinity of the gas introduction port of the manifold main body to partition the internal space of the manifold main body on the gas introduction port side into a plurality of small spaces, so that it is provided for each cylinder of the engine. When the gas discharged from the discharge holes is introduced into the manifold body, they do not interfere with each other, so that the effect of improving the engine output can be obtained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. 1 to 5 are explanatory views of this embodiment , FIG. 1 is a front view, FIG. 2 is a plan view, FIG. 3 is a rear view, and FIG.
Is a sectional view taken along the line AA in FIG. 1, and FIG. 5 is a view as viewed from B in FIG.

In this embodiment , the exhaust manifold 10 is used.
And a pipe mounting flange 20. The exhaust manifold 10 is composed of a flange portion 11 and a manifold body portion 16 and has a wall thickness of 2 mm.

The flange portion 11 is to be mounted on the downstream side of the engine 30 (see FIG. 2), has an outer shell formed in a substantially trapezoidal shape, and has an outer circumference of about 10 for the purpose of increasing strength.
mm folded back. The flange portion 11 has a joint surface 12 that is joined to the engine 30, a plurality (seven in total) of bolt insertion holes 13 provided along the outer contour, and a substantially elliptical gas introduction port 14 provided at a substantially central portion. It has and.

The manifold body 16 includes a flange portion 11
It is formed so as to have a substantially box-like shape starting from the peripheral edge of the gas introduction port 14 provided in the. This manifold body 16
A cylindrical hole (gas discharge port) 17 is formed by performing burring on the side of the flange portion 11 that faces the gas introduction port 14.

The exhaust manifold 10 is formed by integrally molding a flange portion 11 and a manifold main body portion 16. That is, the gas inlet 1 of the flange portion 11
4 is prepared, and the flange portion 11 and the manifold body portion are pressed by pressing a substantially central portion of the metal plate body using a pressing member having the same shape as the inner shape of the manifold body portion 16. 16 and 16 are integrally formed.

The pipe mounting flange 20 is for mounting on a pipe (not shown) such as an exhaust pipe, and has an outer shape formed into a substantially rhombus shape, and the outer periphery is folded back by about 10 mm for the purpose of increasing strength. There is. The pipe mounting flange 20 is provided with a plurality (two in total) of bolt insertion holes 21 provided along the outer contour and a substantially cylindrical insertion hole 22 provided at a substantially central portion.

The exhaust manifold 10 and the pipe mounting flange 20 are connected to each other by the cylindrical hole 1 of the manifold main body 16.
7 is inserted into the insertion hole 22 of the pipe mounting flange 20 and welded to each other for joining .

In the manifold body 16 of the exhaust manifold 10, a plurality of (2
Partition plates 18 are welded. This partition board 1
8 forms a plurality (three) of small spaces 19 by partitioning the internal space of the manifold body 16 on the gas introduction port 14 side, and each of the small spaces 19 is provided with a plurality of exhaust holes 32 provided in the cylinder head 31. Are formed so as to face each other.

[0020] Next is a description of the operation of the present embodiment. As shown in FIG. 2 , the joint surface 12 of the flange portion 11 of the exhaust manifold 10 is brought into close contact with the cylinder head 31 corresponding to the downstream side of the engine 30 via the gasket 40, and the bolt inserted into the bolt insertion hole 13 in this state. (Not shown) is fastened and attached to the engine 30.
At this time, each small space 19 of the manifold main body 16 faces each exhaust hole 32 of the cylinder head 31. on the other hand,
The pipe mounting flange 20 and an exhaust purification catalyst device (not shown) are joined together by a bolt (not shown) inserted through the bolt insertion hole 21.

The gas discharged from the discharge hole 32 provided for each cylinder of the engine 30 is introduced into the manifold main body portion 16 through the gas introduction port 14 provided in the flange portion 11. At this time, the gas introduction port 14 of the manifold main body 16
Since the three small spaces 19 are provided in the internal space on the side facing the exhaust holes 32 of the engine 30,
The gas discharged from 2 is introduced into the manifold main body 16 without interfering with each other, and is discharged from the cylindrical hole 17. The gas discharged from the cylindrical hole 17 passes through an exhaust purification catalyst device (not shown) arranged downstream of the exhaust manifold 10, and is discharged to the outside via an exhaust pipe (not shown).

[0022] Next, a description will be given of the effect of the present embodiment. The exhaust manifold 10 includes a flange portion 11 and a manifold body portion 16 which are integrally formed. The exhaust manifold 10 is configured by one component, which is conventionally composed of a total of three components including an upper case, a lower case and a flange. There is. Therefore, the number of parts is reduced, the welding process is not required, and the manufacturing cost is significantly reduced.

Further, the flange portion 11 of the exhaust manifold 10 and the manifold main body portion 16 are the flange portion 11
Among them, one metal plate-like body without the gas introduction port 14 can be integrally molded by pressing. At this time, since the thickness of the exhaust manifold 10 can be adjusted to about 2 mm by using a metal plate having a predetermined thickness, the heat capacity of the exhaust manifold 10 can be set small. For this reason, the exhaust manifold 10 is heated to a high temperature in a short time after the engine is started, and the catalyst of the exhaust purification catalyst device arranged downstream of the exhaust manifold 10 can be heated to a high temperature, that is, activated. As a result, the effect that the purification efficiency of the discharged gas can be increased can be obtained.

Further, when the gas discharged from each exhaust hole 32 of the engine 30 is introduced into the manifold main body 16,
Since they do not interfere with each other, the effect of improving the engine output can be obtained.

[0025] The present invention is not in any way limited to the above embodiments within the technical scope of the present invention, it goes without saying that practiced in various forms. For example, although the present embodiment shows a single bank of 3 cylinders or V6, it can be used for 4 cylinders, 8 cylinders, etc. in addition to this.

[Brief description of drawings]

FIG. 1 is a front view of the present embodiment .

FIG. 2 is a plan view of the present embodiment .

FIG. 3 is a rear view of this embodiment .

4 is a cross-sectional view taken along the line AA of FIG.

5 is a view from B of FIG. 4. FIG .

[Explanation of symbols]

10 ... Exhaust manifold, 11 ... Flange part, 12 ... Joining surface, 13 ... Bolt insertion hole, 14 ... Gas inlet port, 16 ... Manifold main body part, 17 ... Cylinder -Shaped hole, 18 ... Partition plate, 19 ... Small space, 20 ... Pipe mounting flange, 21 ... Bolt insertion hole, 22 ... Insertion hole, 30 ... Engine, 31 ... ..Cylinder head, 32 ... Exhaust hole, 40 ... Gasket,

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F01N 7/10 F01N 7/18

Claims (2)

(57) [Claims] 1. A flange which is attached to a downstream side of an engine and has a gas introduction port provided at a substantially center thereof, and a flange which is formed into a substantially box-like shape starting from a peripheral edge of the gas introduction port. A manifold main body provided with a gas outlet on the side facing the mouth, the flange and the main body are integrally molded , and 1 is provided near the gas inlet of the manifold main body.
Alternatively, a plurality of partition plates are provided, and the partition plates are
Partition the internal space on the gas inlet side of the manifold body.
And the plurality of small spaces are provided for each cylinder of the engine.
An exhaust manifold, characterized in that it forms a plurality of small spaces facing the provided exhaust holes . 2. The exhaust manifold according to claim 1, wherein the flange and the manifold body are integrally formed by pressing a single metal plate.