JP2000248928A - Exhaust manifold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust manifold which is simple in structure and easy to manufacture. SOLUTION: This manifold is provided with a large flange 2 to be mounted to an engine while being formed with respective inlet holes 10 through 13 corresponding to the respective exhaust ports P1 through P4 of a four cylinder engine, and with an outer shell 4 to be mounted to the large flange 2 to be formed into an exhaust chamber, while the respective inlet holes 10 through 13 are covered. The outer shell member 4 is mounted to the flange 2 by means of entire circumferential welding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust manifold which collects exhaust gas from each exhaust port of a multi-cylinder engine and sends it to an exhaust pipe.

[0002]

2. Description of the Related Art Conventionally, a pipe structure is known as an exhaust manifold.
As shown in FIG. 1, each exhaust port P1
Branch pipes 102 to 105 are provided for each P4.
To 109 are attached by welding. The other ends of the branch pipes 102 to 105 are respectively connected to the collective pipe 110.
It is attached by welding or the like. Then, the flange 112 attached to the collecting pipe 110 was connected to an exhaust pipe (not shown).

[0003]

However, such a conventional apparatus is composed of a large number of parts such as branch pipes 102 to 105, flanges 106 to 109 and 112, a collecting pipe 110, and the like, and is integrated by welding or the like. Due to the structure, there is a problem that manufacturing is complicated. Further, if such an exhaust manifold is formed into a double structure to activate the catalyst of the catalytic converter at the time of starting the engine at an early stage, there is a problem that the structure is further complicated.

An object of the present invention is to provide an exhaust manifold which has a simple structure and is easy to manufacture.

[0005]

In order to achieve the above object, the present invention takes the following means to solve the problem. In other words, in an exhaust manifold in which exhaust gas from each exhaust port of a multi-cylinder engine is collected and sent to an exhaust pipe,
The engine includes one large flange formed with each introduction hole corresponding to each of the exhaust ports and attached to the engine, and an outer shell member attached to the large flange to cover each of the introduction holes to form an exhaust chamber. The exhaust manifold is characterized by that.

[0006] The outer shell member may be attached to the large flange by welding. In addition, an inner pipe communicating with the introduction holes and communicating with the exhaust pipe may be provided in the exhaust chamber to have a double structure. Furthermore,
The outer shell member may be provided with a flange portion overlapping with the large flange, and the flange portion and the large flange may be jointly fastened with a bolt. Alternatively, the flange portion and the large flange may be temporarily fixed by eyelets.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, reference numeral 1 denotes an exhaust manifold, which is used for a multi-cylinder (four-cylinder in this embodiment) engine 100. Engine 10
0 includes first to fourth exhaust ports P1 to P4 communicating with the first to fourth cylinders # 1 to # 4.

The exhaust manifold 1 has a large flange 2, an outer shell member 4, and a small flange 6. As shown in FIG. 3, the large flange 2 is provided with four introduction holes 10 to 13 corresponding to the first to fourth exhaust ports P1 to P4. A plurality of mounting holes 14 for mounting with bolts (not shown)
Are formed. Further, as shown in FIG. 4, an annular projection 16 protruding toward the outer shell member 4 is formed so as to surround the four introduction holes 10 to 13.

The outer shell member 4 covers all the four introduction holes 10 to 13 and is fitted inside the annular projection 16. By the outer shell member 4 and the large flange 2, four introduction holes 1 are formed.
An exhaust chamber 18 that communicates with 0 to 13 is formed. The outer shell member 4 and the large flange 2 are welded to the outer periphery of the outer shell member 4 along the annular projection 16 so that the outer shell member 4 and the large flange 2 are integrated.

The outer shell member 4 has a dent corresponding to the exhaust chamber 18 formed integrally with the plate material by press drawing or the like.
An insertion hole 20 communicating with the exhaust chamber 18 is formed. A connection pipe 22 is inserted into the insertion hole 20, and the connection pipe 2
A small flange 6 is attached to the front end of 2.

Next, the operation of the above-described exhaust manifold 1 of the present embodiment will be described. Engine 100
With the operation of, exhaust gas is sequentially discharged from each of the exhaust ports P1 to P4. Exhaust gas exhausted from each of the exhaust ports P1 to P4 flows into the exhaust chamber 18 through the introduction holes 10 to 13, respectively. After the exhaust gas is collected in the exhaust chamber 18, it is sent to an exhaust pipe (not shown) via the connection pipe 22.

In the exhaust manifold 1 described above, the connecting pipe 22 is inserted into the insertion hole 20 of the press-formed outer shell member 4 and welded all around, and the small flange 6 is attached to the connecting pipe 22 by welding or the like. Further, since the outer shell member 4 is fitted inside the annular protrusion 16 of the large flange 2, the positioning of the outer shell member 4 is easy. Further, the entire circumference is welded along the annular projection 16 to be integrated.

Accordingly, the exhaust manifold 1 has a small number of components and is simple in structure. In addition, since the number of components is small, the weight can be reduced, and since the outer shell member 4 is attached to the large flange 2 by welding all around, the rigidity is increased and the durability is improved.

Next, an exhaust manifold according to a second embodiment different from the above-described embodiment will be described with reference to FIGS. Note that the same members as those in the above-described embodiment are denoted by the same reference numerals, and detailed description is omitted. Book second
The exhaust manifold 30 of the embodiment includes an outer shell member 32 that is slightly larger than the above-described outer shell member 4, and includes first to fourth inner pipes in the exhaust chamber 18 formed by the outer shell member 32 and the large flange 2. It is formed in a double structure provided with 34 to 37.

The first inner pipe 34 has one end connected to the introduction hole 10 communicating with the first exhaust port P1, and is formed to be bent at 90 degrees. 2nd inner pipe 35
Is formed in a “T” shape, and the second exhaust port P2
Is connected to the introduction hole 11 that communicates with. One end of the first inner pipe 34 is inserted and connected to the second inner pipe 35.

The third and fourth inner pipes 36 and 37 are also formed in a "T" shape, and are connected to the introduction holes 12 and 13 communicating with the third exhaust port P3 and the fourth exhaust port P4, respectively. . And the third inner pipe 36
, One end of a second inner pipe 35 is inserted and connected, and one end of a third inner pipe 36 is inserted and connected to the fourth inner pipe 37.

One end of the fourth inner pipe 37 is inserted into the connecting pipe 22 via a wire mesh 38, and each of the introduction holes 10 to 13 is connected to an exhaust pipe (not shown) from the first to fourth inner pipes 34 to 37, The connection is made through a connection pipe 22. Exhaust gas exhausted from the first to fourth exhaust ports P1 to P4 flows into the first to fourth inner pipes 34 to 37 through the respective introduction holes 10 to 13. Then, the air is sent from the connection pipe 22 to an exhaust pipe (not shown).

The thickness of the first to fourth inner pipes 34 to 37 is small. For example, the thickness of the outer shell member 32 is 2.0 m.
m, since the thickness of the first to fourth inner pipes 34 to 37 is 0.8 mm, the heat capacity of the first to fourth inner pipes 34 to 37 is small. Therefore, when the engine is started, the temperature of the exhaust gas passing through the exhaust manifold 30 does not decrease much. Therefore, the temperature of the catalyst in the catalytic converter quickly rises to the temperature at which it is activated, and the purification of exhaust gas is further improved.

When assembling such a double structure, the first to fourth inner pipes 34 to 37 are arranged in the exhaust chamber 18 of the outer shell member 32, and as shown in FIG. 32 and the first to fourth inner pipes 34 to
Spot welding is performed on a welding portion 38 with the side surface 37. The outer shell member 32 and the first to fourth inner pipes 34 to
37 is inserted into the annular projection 16, and the entire outer periphery of the outer shell member 32 is welded along the annular projection 16. Thereby, the exhaust manifold 30 having a double structure can be easily formed.

Next, an exhaust manifold according to a third embodiment will be described with reference to FIGS. Book 3
The exhaust manifold 40 of the embodiment includes a large flange 42 and an outer shell member 46, which are stacked and attached to the engine 100. Like the large flange 2 described above, the large flange 42 has four introduction holes (not shown).

The outer shell member 46 covers the introduction hole, and an exhaust chamber communicating with the introduction hole is formed by the outer shell member 46 and the large flange 42. The outer shell member 46 has a large flange 42
Is formed. Further, as shown in FIG. 9, a small flange 54 is attached to the outer shell member 46 by turning an edge of a connection hole 52 formed in the outer shell member 46 outward.

On the flange portion 48 of the outer shell member 46, an annular projection 44 is formed along the exhaust chamber on the large flange 42 side to seal the exhaust chamber. Mounting hole 5 for outer shell member 46
An eyelet 56 is inserted into the mounting hole 52 of the flange 1 and the flange portion 48, and the large flange 42 and the outer shell member 46 are temporarily fixed. The eyelets 56 are inserted in some of the mounting holes, and it is sufficient to provide them in at least two mounting holes 51 and 52.

The exhaust manifold 40 is connected to the engine 1
At the time of attachment to 00, a bolt (not shown) is inserted into the eyelet 56, and the large flange 42 and the outer shell member 46 are fastened together. Also in the case of the exhaust manifold 40 of the third embodiment, the first to fourth exhaust ports P1
The exhaust gas discharged from P4 to P4 passes through the introduction hole and the exhaust chamber and is sent from the connection pipe 22 to an exhaust pipe (not shown).

In the exhaust manifold 40 of the third embodiment, the large flange 42 and the outer shell member 46 are fastened together to the engine 100 by bolts, and the small flange 54 is also attached by bending the outer shell member 46. The exhaust manifold 40 can be constructed without using it. Therefore, the exhaust manifold 40 can be manufactured more easily.

The present invention is not limited to such an embodiment at all, and can be implemented in various modes without departing from the gist of the present invention.

[0026]

As described in detail above, the exhaust manifold of the present invention has an advantage that its structure is simple and its manufacture is easy. In addition, by providing the inner pipe in the exhaust chamber, an exhaust manifold having a double structure can be easily formed. Further, a flange portion is provided on the outer shell member,
When the large flange and the outer shell member are jointly fastened by bolts, the structure can be achieved without using welding, so that the manufacturing becomes easier.

[Brief description of the drawings]

FIG. 1 is a plan view showing an exhaust manifold according to an embodiment of the present invention attached to an engine.

FIG. 2 is a front view of the exhaust manifold according to the embodiment.

FIG. 3 is an enlarged sectional view taken along the line AA of FIG. 2;

FIG. 4 is an enlarged sectional view taken along the line BB of FIG. 2;

FIG. 5 is an enlarged cross-sectional view of an exhaust manifold according to a second embodiment.

FIG. 6 is an enlarged cross-sectional view of CC of FIG. 5;

FIG. 7 is a plan view of an exhaust manifold according to a third embodiment.

FIG. 8 is a front view of an exhaust manifold according to a third embodiment.

FIG. 9 is an enlarged cross-sectional view of DD in FIG. 8;

FIG. 10 is an EE enlarged sectional view of FIG. 8;

FIG. 11 is a plan view of a conventional exhaust manifold.

[Explanation of symbols]

 1, 30, 40 ... exhaust manifold 2, 42 ... large flange 4, 32, 46 ... outer shell member 6, 54 ... small flange 10-13 ... introduction hole 16 ... annular protrusion 18 ... exhaust chamber 20 ... insertion hole 22 ... Connection pipe 34 First inner pipe 35 Second inner pipe 36 Third inner pipe 37 Fourth inner pipe 48 Flange 56 Eyelet

Claims (5)

[Claims] 1. An exhaust manifold for collecting exhaust gas from each exhaust port of a multi-cylinder engine and sending the collected exhaust gas to an exhaust pipe. An exhaust manifold comprising: a flange; and an outer shell member attached to the large flange so as to cover each of the introduction holes to form an exhaust chamber. 2. The exhaust manifold according to claim 1, wherein the outer shell member is attached to the large flange by welding. 3. An exhaust manifold, wherein an inner pipe communicating with each of the introduction holes and communicating with the exhaust pipe is provided in the exhaust chamber to form a double structure. 4. The exhaust manifold according to claim 1, wherein a flange portion overlapping the large flange is provided on the outer shell member, and the flange portion and the large flange are jointly fastened with bolts. 5. The method according to claim 1, wherein the flange portion and the large flange are
5. The exhaust manifold according to claim 4, wherein the exhaust manifold is temporarily fixed by eyelets.