JPH0968038A - Exhaust manifold for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a collecting pipe body reducing the sudden change of cross-sectional area at the time of exhaust gas flowing so as to be advantageous in the decrease of defectiveness such as noise. SOLUTION: An exhaust manifold has a pipe body group provided with pipe bodies individually connected to each cylinder of an internal combustion engine, and a collecting pipe body 4 for uniting exhaust gas individually flowing in each pipe body. The collecting pipe body 4 has a first confluence passage 6 for uniting exhaust gas discharged from the respective cylinders not continuos in ignition order. The first confluence passage 6 is formed into spectacle shape cross section and provided with passages 6J1 , 6J4 , and a partition wall part 64J protruded in a direction along a tangent in the mutual boundary area of the passages 6J1 , 6J4 . The protruding quantity of the partition wall part 64J is gradually lost toward the lower reaches. A second confluence passage 7 is also formed in the same way.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an exhaust manifold of an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, as an exhaust manifold of a four-cylinder internal combustion engine, there is known a technique of combining exhaust gases from cylinders whose ignition order is not continuous on the downstream side (Japanese Patent Laid-Open No. 3-92531). According to this technique, not only exhaust interference can be suppressed, but also a negative pressure wave generated by blowdown of a certain cylinder can be applied to the exhaust process of another cylinder.

[0003]

However, according to the technique disclosed in the above publication, the change in the cross-sectional area when the exhaust gas flows is not always taken into consideration, and therefore the change in the cross-sectional area when the exhaust gas flows is caused. The improvement against abnormal noise was not always sufficient. The present invention has been made in view of the above circumstances, and an object thereof is to provide an exhaust manifold of an internal combustion engine that is advantageous in reducing abrupt cross-sectional area change when exhaust gas flows and reducing defects such as abnormal noise. There is.

[0004]

An exhaust manifold of an internal combustion engine according to a first aspect of the present invention includes a tubular body group which is connected to each cylinder of the internal combustion engine and is provided with the same number of tubular bodies as the number of cylinders, and a tubular body group. Each of the pipes has a fitting opening into which the axial end portion of the pipe is fitted, and one discharge opening is provided for combining the exhaust gas flowing individually in the pipe and discharging the combined exhaust gas. An exhaust manifold including a collecting pipe, wherein the collecting pipe includes a first merging passage that joins exhaust gas discharged from each cylinder whose ignition sequence is not continuous and another cylinder whose ignition sequence is not continuous. A second merging passage that joins the exhaust gas that has been exhausted, and the first merging passage and the second merging passage each have a passage that individually connects to each cylinder in a cross-section that intersects the direction in which the exhaust gas flows. , In the boundary area between passages The cross-section has a shape of a spectacles having a partition wall portion projecting in the direction along the tangent line, and the projection amount of the partition wall portion gradually disappears in the cross-section as it goes downstream of the exhaust gas. It is characterized by being.

An exhaust manifold of an internal combustion engine according to a second aspect of the present invention is characterized in that, of the collecting pipes with the pipes separated, the discharge opening can be seen through the fitting openings when viewed with the naked eye. To do. According to the exhaust manifold of the internal combustion engine of the first aspect, the exhaust gas from the cylinders whose ignition order is not continuous joins in the first joining passage. Further, exhaust gas from another cylinder whose ignition sequence is not continuous is
Merge at the merge passage.

Each of the first and second merging passages is provided with a passage and a partition wall portion projecting in a direction along a tangent line in a boundary region between the passages in a cross section transverse to a direction in which exhaust gas flows. The cross-section has a shape of spectacles. The amount of protrusion of the partition wall portion has a structure that gradually disappears toward the downstream side of the exhaust gas in the cross section.

Therefore, the exhaust gas passing through the first merging passage smoothly joins without causing a sudden change in cross-sectional area. Similarly, the exhaust gas passing through the second merging passage smoothly joins without causing a sudden change in cross-sectional area. The exhaust gas flowing through the first merging passage and the exhaust gas flowing through the second merging passage finally merge inside the collecting pipe, and are discharged to the outside through the discharge opening.

According to the exhaust manifold of the internal combustion engine of the second aspect of the present invention, the exhaust gas does not collide with the side wall because the discharge opening can be seen through the fitting openings of the collecting pipe when viewed with the naked eye. It will be reduced.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. First, for convenience of description, an internal combustion engine 9 equipped with the exhaust manifold 1 according to the present embodiment will be described.
The internal combustion engine 9 has four cylinders and includes first cylinder 91 to fourth cylinder 94. The ignition order for this is the first cylinder 91
→ 3rd cylinder 93 → 4th cylinder 94 → 2nd cylinder 92.

Next, the exhaust manifold 1 installed in the internal combustion engine 9 will be described. The exhaust manifold 1 includes a tube group 3 composed of four tubes 2 and one collecting tube 4. The pipes 2 forming the pipe group 3 are individually connected to the respective cylinders of the internal combustion engine 9. Therefore, the tube body 2 is
As described above, the internal combustion engine 9 is equipped with the same number of cylinders, that is, four cylinders. The tube group 3 is equipped with a mounting flange plate 5 for mounting on the mounting portion of the internal combustion engine 9. The tube body 2 is made of a stainless steel pipe. The length of each pipe 2 up to the collecting pipe 4 is adapted so as to unify the flow path length. The collecting pipe body 4 is made of spheroidal graphite cast iron.

Next, the collecting pipe body 4 which is a main part of this embodiment will be described. That is, the collecting pipe body 4 is for joining the exhaust gases that individually flow in the four pipe bodies 2.
The collecting pipe body 4 has the same number as the number of the pipe bodies 2, that is, four fitting openings 4a. The shaft ends 2h of the respective tubular bodies 2 constituting the tubular body group 3 are individually fitted into the respective fitting openings 4a and fixed by welding.

As can be seen from FIG. 3, a first merging passage 6 and a second merging passage 7 are formed in the collecting pipe body 4. The first merging passage 6 and the second merging passage 7 will be described. The first merging passage 6 is a passage for merging and collecting the exhaust gases that individually flow in the first cylinder 91 and the fourth cylinder 94 of the internal combustion engine 9 whose ignition orders are not continuous with each other. The second merging passage 7 is a passage for merging and collecting the exhaust gases that individually flow in the second cylinder 92 and the third cylinder 93 of the internal combustion engine 9 whose ignition order is not continuous.

As described above, since the exhaust gas from the first cylinder 91 and the fourth cylinder 94 whose ignition order is not continuous flows in the first merging passage 6, the flow rate of the exhaust gas in the first merging passage 6 becomes excessive. To be prevented. Similarly, in the second merging passage 7,
Since the exhaust gas from the second cylinder 92 and the third cylinder 93 which do not have a continuous ignition sequence flows, the flow rate of the exhaust gas in the second merging passage 7 is prevented from becoming excessive.

3 to 10 show the first merging passage 6 and the second merging passage 6.
It shows the transition of the cross section in both of the confluence passages 7, and shifts to the downstream side in the flowing direction of the exhaust gas as the drawing number increases. The cross section means a cross section along a direction transverse to the direction in which exhaust gas flows. In the cross section shown in FIG. 3, the first merging passage 6 has the first cylinders 91 and 4
A passage 6H _1, 6H ₄ cross section substantially forms a circular shape that leads to individually turn the cylinder 94, the partition wall portion projecting in a direction, i.e. the arrow XA direction along the tangential line at passage 6H _1, 6H ₄ between the boundary region 64H It has and. Further, in the cross section shown in FIG. 3, the second merging passage 7 includes the passages 7H ₂ and 7H ₃ which are individually connected to the second cylinder 92 and the third cylinder 93, and the passage 7
The partition wall portion 74H projects in the direction along the tangent line in the boundary region between H ₂ and 7H ₃ , that is, in the arrow XB direction.

In the cross section shown in FIG. 4, the first merging passage 6
Are the passages 6I ₁ and 6I _4, which are transformed into egg shapes, and the passages 6I.
₁ , 6I ₄ and a partition wall portion 64I projecting in the direction along the tangent line in the boundary region between the 6I _{4 and} each other. Similarly, as shown in FIG. 4, the second merging passage 7 has deformed passages 7I ₂ and 7I ₃
And a partition wall portion 74I projecting in the direction along the tangent in the boundary region between the passages 7I ₂ and 7I ₃ , and thus has a “glass shape” as a whole. Note that the “glass shape” can be considered as a “deformed ∞ shape” or a “deformed horizontal 8-shaped shape”.

In the cross section shown in FIG. 5, the first merging passage 6
Is the deformed passage 6J₁, 6J_FourAnd passage 6J₁, 6J
_FourA feature that protrudes in the direction along the tangent in the boundary area between the
It is equipped with a cut wall portion 64J,
The state ”. Similarly, as shown in FIG. 5, the second merging passage
7 is a deformed passage 7J₂, 7J_ThreeAnd passage 7J₂, 7
J _ThreeProject in the direction along the tangent in the boundary area of each other
It is provided with a partition wall portion 74J. As you can see from Figure 5
An intermediate partition for partitioning the first merging passage 6 and the second merging passage 7
The wall portion 8J has a thickness of t5, and is becoming thinner.

In the cross section shown in FIG. 6, the first merging passage 6
Is a further transformed passage 6K₁, 6K_FourAnd passage 6K₁,
6K_FourProject in the direction along the tangent in the boundary area between the two
It has a partition wall section 64K that
Shape ”. Similarly, as shown in FIG. 6, the second combined distribution
Path 7 is a further modified path 7K₂, 7K_ThreeAnd passage 7K
₂, 7K_ThreeProject in the direction along the tangent in the boundary area between
It is equipped with a partition wall 74K that projects, and
It has a "glass shape". First as you can see from FIG.
The merging passage 6 and the second merging passage 7 are intermediate partition walls having a thickness t6.
It is separated by section 8K.

In the cross section shown in FIG. 7, the first merging passage 6
Is a further transformed passage 6L₁, 6L_FourAnd passage 6L₁,
6L_FourProject in the direction along the tangent in the boundary area between the two
It is equipped with a partition wall section 64L that
Shape ”. Similarly, as shown in FIG. 7, the second combined distribution
The passage 7 is a further transformed passage 7L.₂, 7L_ThreeAnd passage 7L
₂, 7L_ThreeProject in the direction along the tangent in the boundary area between
It is equipped with a partition wall part 74L that comes out,
It has a deformed “glass shape”. Understanding from Figure 7
As much as possible, the first merging passage 6 and the second merging passage 7 are intermediate products.
It is partitioned by the cut wall portion 8L.

In the cross section shown in FIG. 8, the first merging passage 6
Of the passages 6M ₁ and 6M ₄ that have been further deformed and merged
And a partition wall portion 64M projecting in the direction along the tangent line in the boundary region between the passages 6M ₁ and 6M ₄ ,
The "eyeglass shape" is considerably broken, and the unity of the passage 6 is improved. Similarly, as shown in FIG.
Is the passages 7M ₂ and 7M ₃ that have been deformed and have merged,
The partition wall portion 74M protruding in the direction along the tangent in the boundary region between the passages 7M ₂ and 7M ₃ is provided, and the “eyeglass shape” is considerably collapsed, and the passage 6 is improved in unity. Moreover, as can be understood from FIG. 8, the first merging passage 6
The amount of protrusion of the intermediate partition wall portion 8M that separates the second merging passage 7 and the second merging passage 7 is as small as L8, and it is considerably disappearing.

Further, as can be understood from FIG. 9, the protruding amount of the intermediate partition wall portion 8N for partitioning the first merging passage 6 and the second merging passage 7 is L9, which is a minute amount, and is further disappearing. Therefore, according to the cross section shown in FIG. 9, the merging of the first merging passage 6 and the second merging passage 7 has progressed considerably. Furthermore, FIG.
According to the cross section shown in FIG. 3, the first merging passage 6 and the second merging passage 7 are completely disappeared, and the first merging passage 6 and the second merging passage 7 are completely merged, and Inner wall surface 8f
The circular discharge opening 8 having the above is formed.

As can be understood from the above description, the partition walls 64H, 64I, 64J, 64 for partitioning the "eyeglass shape" in the first merging passage 6 shown in FIGS.
As can be understood from the transition of K, 64L, and 64M, the partition wall portions 64H to 64M in the first merging passage 6 are configured to gradually disappear toward the downstream side in the exhaust gas flowing direction.

Also in the second merging passage 7 shown in FIGS. 3 to 8, similarly, it can be understood from the transition of the partition wall portions 74H, 74I, 74J, 74K, 74L and 74M for partitioning the "glass shape". In addition, the partition wall portions 74H to 74M in the seventh merging passage 7 are configured to gradually disappear toward the downstream side in the exhaust gas flowing direction.

Further features of this embodiment will be described. 11 and 12 are perspective views of the collecting pipe body 4 of the exhaust manifold 1. As shown in FIGS. 11 and 12, the extension lines of the central axis lines P1 to P4 related to the first merging passage 6 and the second merging passage 7 of the collecting pipe body 4 are the discharge openings 8 which are the outlets of the collecting pipe body 4. It agrees at the center point Px of. And the collecting pipe 4
Of the fitting openings 4a, the entire discharge opening 8 can be seen through by a human eye.

As described above, according to this embodiment, the partition wall portions 64H to 64M partitioning the first merging passage 6 gradually disappear toward the downstream of the exhaust gas, as can be understood from the transition thereof. It has a structure that goes on. Similarly, the partition wall portions 74H to 74M that partition the second merging passage 7
As you can understand from the transition of this, it has a structure that gradually disappears as it goes downstream of the exhaust gas.
Therefore, the exhaust gas joins smoothly without causing a sudden change in cross-sectional area. Therefore, it is possible to contribute to alleviation of abnormal noise at the time of gas passage due to a sudden change in the sectional area of the exhaust gas.

Further, according to this embodiment, the central axis lines P1 to P1 of the first confluence passage 6 and the second confluence passage 7 of the collecting pipe body 4 are respectively formed.
The extension line of P4 is the center point Px of the discharge opening 8 of the collecting pipe body 4.
The exhaust gas collides with the inner surfaces of the side walls of the first confluence passage 6 and the second confluence passage 7 because the discharge opening 8 can be seen through the fitting openings 4a of the collecting pipe 4 with the naked eye. Doing is alleviated.

[0026]

According to the exhaust manifold of the first aspect, it is possible to reduce a sudden change in cross-sectional area when exhaust gas flows,
This is advantageous for reducing problems such as abnormal noise. According to the exhaust manifold of the second aspect, since the discharge opening can be seen through the fitting openings of the collecting pipe body with the naked eye, it is possible to prevent the exhaust gas from disappearing to the side wall and to make a noise. It is even more advantageous in reducing the above problems.

[Brief description of drawings]

FIG. 1 is a side view of an exhaust manifold.

FIG. 2 is a side view of the exhaust manifold viewed from different directions.

FIG. 3 is a cross-sectional view of a first merging passage and a second merging passage.

FIG. 4 is a cross-sectional view of a first merging passage and a second merging passage.

FIG. 5 is a cross-sectional view of a first merging passage and a second merging passage.

FIG. 6 is a cross-sectional view of a first merging passage and a second merging passage.

FIG. 7 is a cross-sectional view of a first merging passage and a second merging passage.

FIG. 8 is a cross-sectional view of a first merging passage and a second merging passage.

FIG. 9 is a cross-sectional view of a first merging passage and a second merging passage.

FIG. 10 is a cross-sectional view of a discharge opening.

FIG. 11 is a plan view of a collecting pipe body.

FIG. 12 is a side view of a collecting pipe body.

[Explanation of symbols]

In the figure, 1 is an exhaust manifold, 2 is a tubular body, 3 is a tubular body group,
4 is a collecting pipe, 6 is a first merging passage, 7 is a second merging passage,
Reference numeral 9 indicates an internal combustion engine.

Claims (2)

[Claims] 1. A tubular body group which is individually connected to each cylinder of an internal combustion engine and has the same number of tubular bodies as the number of the cylinders, and a shaft end portion of each of the tubular bodies constituting the tubular body group is fitted to each other. An exhaust manifold having a fitting opening and a collecting pipe body for merging exhaust gases individually flowing in the pipe body and for discharging the combined exhaust gas. The collecting pipe includes a first merging passage that joins exhaust gas discharged from each cylinder whose ignition order is not continuous, and a first joining passage that joins exhaust gas discharged from another cylinder whose ignition order is not continuous. The first confluence passage and the second confluence passage, each of which has a passage that is individually connected to each cylinder and a boundary between the passages in a cross section that intersects the exhaust gas flow direction. Partition wall protruding in the direction along the tangent in the area An exhaust gas of an internal combustion engine, characterized in that it has a cross-sectional spectacles-shaped shape having a cross section, and the projection amount of the partition wall portion gradually disappears in the cross section toward the downstream side of the exhaust gas. Manifold. 2. A collecting pipe body in a state where the pipe body is detached,
The exhaust manifold of an internal combustion engine according to claim 1, wherein the discharge opening is visible through the fitting openings when viewed with the naked eye.