JPH0650143A - Exhaust pipe structure - Google Patents

Abstract

PURPOSE:To surely eliminate deformation of each of installation flanges and to improve sealing performance by independently installing each of the installation flanges respectively on a plural number of branch pipes connected in parallel to a manifold main body and displacing each of one side installation tools of the installation flanges on both sides to both end sides. CONSTITUTION:An exhaust manifold 18 is constituted of a manifold main body 20, a connection flange 22 arranged on its one end and a plural number of branch pipes 24, 26, 28 arranged in parallel sequentially from the other end. In this case, on each of the branch pipes 24, 26, 28, a plural number of installation flanges 36, 38, 40 fixed on a cylinder head 6 are independently installed. On both ends of the manifold main body 20, each of upper bolts A-1a, A-3c to install the installation flanges 36, 40 on the both ends is respectively offset on both ends of the manifold main body 20. Consequently, even in the case the manifold main body 20 causes distortion by exhaust heat, it is possible to eliminate deformation of the both end installation flanges 36, 40 to apart from the cylinder head 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust pipe structure,
The present invention relates to an exhaust pipe structure that can effectively prevent exhaust gas leakage with a simple structure.

[0002]

2. Description of the Related Art In an engine, an exhaust manifold for guiding exhaust gas discharged from each cylinder to an exhaust pipe is provided in a cylinder head.

As shown in FIG. 7, the exhaust manifold 202 is generally a manifold body 204 oriented in the series direction X of each exhaust port (not shown) of an engine (not shown).
And first, second, and third branch pipes 206, 208, 210 that are connected in parallel to the manifold body 204 by forming branch passages (not shown) communicating with the exhaust ports, and the cylinder head of the engine. The first, second, and third branch pipes 206, 208, 210 are integrally connected to the mounting flange 212 to be fixed via a gasket.

Further, as shown in FIG. 8, in the exhaust manifold, each branch pipe (not shown) connected in parallel to the main body of the manifold independently has first, second and third mounting flanges 302, 304. There is a structure in which each 306 is provided. In this case, in the first mounting flange 302, the first exhaust port hole 308 is formed at a substantially central portion, and the first, second and third centers O1, O2, O3 of each branch passage are formed.
Two one-sided mounting holes located on one side of the branch path center connection line L passing through the first path, that is, below the first center line O1 and being substantially symmetrical with respect to the first center line C1 perpendicular to the branch path center connection line L. The first lower mounting holes 310, 312 are formed, and at the other side of the branch path center connection L, that is, on the upper side, one upper mounting hole 314 that is the other side mounting hole is formed on the first center line C1. Has been formed. These first lower mounting holes 310, 312
Mounting bolts (not shown), which are one-side and other-side mounting tools, are inserted into the first upper mounting hole 314 and the first upper mounting hole 314, respectively. Therefore, the first mounting flange 302 is supported at three points in a triangular shape at one end portion in the longitudinal direction (the same direction as the series direction X) of the manifold main body.

In the second mounting flange 304, a second exhaust port hole 316 is formed at a substantially central portion, and one side of the branch path center connection line L, that is, below, passes through the second center O2. Two second lower mounting holes 318 and 320 located substantially symmetrically with respect to a second center line C2 perpendicular to the branch line center connection L are formed, and the other side of the branch line center connection L, that is, the upper side. A second upper mounting hole 322 is formed on the second center line C2. The second lower mounting holes 318 and 320 and the second upper mounting hole 322 have
A mounting bolt (not shown) that is a mounting tool is inserted. Therefore, the second mounting flange 304 is supported at three points in a triangular shape at a substantially central portion in the longitudinal direction of the manifold body.

Further, in the third mounting flange 306, a third exhaust port hole 324 is formed in a substantially central portion, and one side of the branch passage center connection L, that is, below, passes through the third center O3. Two third lower mounting holes 326, 328 positioned substantially symmetrically with respect to a third center line C3 perpendicular to the branch line center connection L are formed, and the other side of the branch line center connection L, that is, the upper side. Thus, a third upper mounting hole 330 is formed on the third centerline C3. These third lower mounting holes 326, 328 and third upper mounting hole 330 have
A mounting bolt (not shown) that is a mounting tool is inserted. Therefore, the third mounting flange 306 is supported at the other end portion in the longitudinal direction of the manifold body at three points in a triangular shape.

Further, such an exhaust manifold mounting structure is disclosed in Japanese Utility Model Publication No. 63-162918 and Japanese Utility Model Publication No. 60-120219. Actual Kaisho 6
The one described in Japanese Patent Laid-Open No. 3-162918 has an exhaust passage,
A head-side flange portion, a plurality of exhaust pipes made of steel pipe connected to the head-side flange portion and extending to a lower collecting portion,
The exhaust pipe corresponding to the inner cylinder is curved downward as it is so that it does not overlap with the tightening portion of the head side flange portion, and the outer cylinder is also formed. The exhaust pipe corresponding to is greatly curved inward so as not to overlap the tightening portion of the head side flange portion. In addition, 60-12021
According to Japanese Patent Laid-Open No. 9-90, the mounting surface of the flange portion of the exhaust manifold mounted on the cylinder head of the internal combustion engine is formed so as to be a concave surface with respect to the plane of the mounting surface of the cylinder head in advance. Is fixed to the mounting surface of the cylinder head by correcting the concave surface of the flange portion of the exhaust manifold into a substantially flat body by tightening with a bolt or the like.

[0008]

However, conventionally, the exhaust manifold is exposed to high-temperature exhaust gas, and as shown in FIG. 7, when the manifold main body 204 is distorted, both ends of the mounting flange 212 are correspondingly deformed. A big distortion occurs,
This attachment flange 212 is deformed into a curve (indicated by the one-dot chain line arrow), which deteriorates the sealing property of the exhaust port at the end portion on the outside of the engine, and has a drawback that the exhaust gas leaks.

Further, as shown in FIG. 8, the first, second, and third mounting flanges 302, 30 are associated with the respective exhaust ports.
Even when 4 and 306 are independently installed in each branch pipe,
Each upper mounting hole 314, 322, 330 has a center line C1,
Since it is located above C2 and C3, when the manifold body is distorted, the first and third mounting flanges 302,
There is a drawback that the deformation occurs in 306, which deteriorates the sealing property of the exhaust port at this portion.

In order to eliminate these drawbacks, it is conceivable to change the shape of the exhaust manifold to minimize the distortion generated in the exhaust manifold or change the shape of the gasket interposed between the mounting flange and the cylinder head surface. However, it is difficult to change because it is disadvantageous in layout,
This caused the inconvenience of being disadvantageous in terms of cost.

[0011]

Therefore, in order to eliminate the above-mentioned inconvenience, the present invention forms a manifold body directed in a serial direction of each exhaust port of an engine and each branch passage communicating with each exhaust port. An exhaust manifold provided with each branch pipe connected in parallel to the manifold main body and a mounting flange connected to each branch pipe to be fixed to the engine, and a branch passage center passing through each center of each branch passage. Two one-sided fixtures that are located on one side of the connection and pass through the center of the branch path and are substantially symmetrical with respect to a center line that is orthogonal to the center path of the branch path, and are located on the other side of the center connection of the branch path. In an exhaust pipe structure in which the attachment flange is attached to the engine by one other-side attachment, each branch pipe is provided with each attachment flange independently, and a longitudinal end portion of the manifold main body. The other side fitting for attaching the mounting flange located the center line of the branch path is positioned on the end of the manifold body, characterized in that provided.

[0012]

According to the structure of the present invention, at the end portion of the manifold main body of the exhaust manifold, the other side fitting is located closer to the end side of the manifold main body than the center line of the branch passage. Even if a problem occurs, each mounting flange will not be deformed, and by only slightly changing the tightening points of the mounting flange, exhaust leakage can be effectively prevented and the layout may be affected. Absent.

[0013]

Embodiments of the present invention will be described in detail and specifically with reference to the drawings. 1 to 6 show an embodiment of the present invention. In FIGS. 1 and 2, 2 is a V-type engine which is an engine. The V-type engine 2 is configured by mounting primary and secondary cylinder heads 6 and 8 on a V-shaped primary and secondary cylinder banks (not shown) above a cylinder block 4. It has primary and secondary engine banks 10, 12. A crank bearing cap 14 is attached to the lower part of the cylinder block 4,
This crank bearing cap 14 has an oil pan 1
6 is attached.

The primary engine bank 10 is shown in FIG.
As shown in FIG. 5, a primary side exhaust manifold 18 is attached to guide each exhaust of each primary side cylinder (not shown) together.

As shown in FIG. 3, the primary side exhaust manifold 18 has a linear primary side manifold body 20 directed in the series direction X of each primary side exhaust port (not shown), and the primary side manifold body 20. Primary side connecting flange 22 provided at one end of the primary side connecting flange 22 and primary side first, second, and third branch pipes 24 sequentially arranged in parallel on the primary side manifold main body 20 from the end opposite to the primary side connecting flange 22. , 26, and 28.

The primary side first, second and third branch pipes 24,
As shown in FIG. 3, 26 and 28 form primary side first, second and third branch paths 30, 32 and 34. The primary side first, second, and third centers PO1, PO2, and PO3 of the primary side first, second, and third branch passages 30, 32, and 34 are located in the exhaust ports of the primary side manifold body 20 in the longitudinal direction. It is located on the primary side branch path connection PL that is directed in the serial direction X. This primary-side branch path connection PL is parallel to the axis of the primary-side manifold body 20.

The primary side first, second and third branch pipes 24,
First and second primary sides 26 and 28 are fixed to the primary side cylinder head 6 via respective gaskets (not shown).
The third mounting flanges 36, 38, 40 are independently provided.

The primary side first mounting flange 36 is shown in FIG.
As shown in FIG. 3, the secondary manifold is located at one end of the primary manifold body 20 on the side opposite to the primary connection flange 22. As shown in FIG. 4, the primary side first mounting flange 36 is formed with a primary side first exhaust port hole 42 at the central portion thereof, and also on one side of the primary side branch path center connection PL, that is, at the lower side. , The primary side first lower mounting holes 44, 4 which are two one side mounting holes symmetrically with respect to the primary side first center line PC1 passing through the primary side first center PO1 and orthogonal to the primary side branch path center connection line PL.
6 is formed, and the primary side branch path center connection P
On the other side of L, that is, on the upper side, the distance PD is closer to one end side of the primary side manifold main body 20 than the primary side first center line PC1.
A primary first upper mounting hole 48, which is one mounting hole on the other side, is formed at a distance of 1. Primary-side first lower mounting bolts A-1a and A-1b are inserted respectively into the primary-side first lower mounting holes 44 and 46 as primary-side first lower mounting tools, and at the primary-side first upper mounting holes 48. The primary side first upper mounting bolt A-1c is inserted as the primary side first upper mounting tool.

Further, the primary side second mounting flange 38
As shown in FIG. 3, the primary side manifold body 2 is provided between the primary side first mounting flange 36 and the primary side third mounting flange 40.
It is located at a substantially central portion of 0 in the longitudinal direction. As shown in FIG. 4, a hole 50 for the primary side second exhaust port is formed in the central portion of the primary side second mounting flange 38, and also on one side of the primary side branch path center connection PL, that is, at the lower side. , The primary side second lower mounting holes 52, 54 are formed symmetrically with respect to the primary side second center line PC2 that passes through the primary side second center PO2 and is orthogonal to the primary side branch path center connection line PL. On the other side of the branch path center connection PL, that is, on the upper side, a primary second upper mounting hole 56 is formed on the primary second central line PC2.

A primary second lower mounting bolt A is provided in the primary second lower mounting holes 52 and 54 as a primary second lower mounting tool.
-2a, A-2b are respectively inserted, and the primary second upper mounting bolts A-2c are inserted into the primary second upper mounting holes 56 as the primary second upper mounting members.

The third mounting flange 40 on the primary side is shown in FIG.
As shown in FIG. 3, the secondary side connecting flange 22 is located at the other end portion of the primary side manifold body 20. As shown in FIG. 4, a primary side third exhaust port hole 58 is formed in the central portion of the primary side third mounting flange 40, and also on one side of the primary side branch path center connection PL, that is, at the lower side. , The primary lower branch mounting holes 60 and 62 are formed symmetrically with respect to the primary third central line PC3 that passes through the primary third central point PO3 and is orthogonal to the primary branch central line PL. On the other side of the center connection line PL, that is, on the upper side, a primary side third upper mounting hole 64 is formed at a distance PD2 from the primary side third center line PC3 to the primary side connecting flange 22 side.

A primary third lower mounting bolt A is provided as a primary third lower mounting member in the primary third lower mounting holes 60 and 62.
-3a and A-3b are respectively inserted, and the primary side third upper mounting bolt A-3c is inserted into the primary side third upper mounting hole 64 as a primary side third upper mounting tool.

Further, as shown in FIG. 2, the secondary engine bank 12 is provided with a secondary exhaust manifold 66 for collectively guiding the exhausts of the secondary cylinders (not shown).

As shown in FIG. 5, the secondary side exhaust manifold 66 is provided with a linear secondary side manifold main body 68 which is directed in the series direction X of each secondary side exhaust port (not shown), and this secondary side exhaust manifold 66. The secondary side connecting flange 70 provided on one end side of the side manifold main body 68, and the secondary side first sequentially arranged on the secondary side manifold main body 70 from the end opposite to the secondary side connecting flange 70. , And second and third branch pipes 72, 74, and 76.

The secondary side first, second and third branch pipes 72,
As shown in FIG. 5, 74 and 76 form secondary side first, second and third branch paths 78, 80 and 82. The secondary side first, second, and third centers SO1, SO2, and SO3 of the secondary side first, second, and third branch passages 78, 80, and 82 are the longitudinal direction of the secondary side manifold body 68. It is located on the secondary side branch path connection SL that is directed in the series direction X of the exhaust ports. The secondary branch path connection SL is parallel to the axis of the secondary manifold body 68.

The secondary side first, second and third branch pipes 72,
The secondary side cylinder heads 8 and 74 are fixed to the secondary side cylinder head 8 via respective gaskets (not shown).
Third mounting flanges 84, 86, 88 are provided independently of each other.

The secondary side first mounting flange 84 is shown in FIG.
As shown in FIG. 5, the secondary manifold main body 68 is located at one end of the secondary manifold main body 68 on the side opposite to the secondary connection flange 70. As shown in FIG. 6, a secondary side first exhaust port hole 90 is formed in the central portion of the secondary side first mounting flange 84, and one side of the secondary side branch path center connection SL is provided. That is, the secondary side branch path center connection SL passing through the secondary side first center SO1 below
A secondary side first lower mounting hole 92 which is a one side mounting hole symmetrically with respect to a secondary side first center line SC1 orthogonal to
94 is formed, and on the other side of the secondary side branch path center connection SL, that is, at the upper side, the secondary side first center line SC1
Distance S to one end of the secondary manifold body 68
A secondary-side first upper mounting hole 96, which is the other-side mounting hole, is formed at a distance of D1. The secondary side first lower mounting hole 9
Secondary side first lower mounting bolts B-1a and B-1b are respectively inserted as secondary side first lower mounting tools into the cables 2, 94, and the secondary side first upper mounting holes 96 have secondary side first lower mounting bolts B-1a and B-1b. The secondary first upper mounting bolt B-1c is inserted as the first upper mounting member.

Further, the secondary side second mounting flange 86
As shown in FIG. 5, the secondary side manifold body 6 is provided between the secondary side first mounting flange 84 and the secondary side third mounting flange 88.
8 is located at a substantially central portion in the longitudinal direction. As shown in FIG. 6, a secondary side second exhaust port hole 98 is formed in the central portion of the secondary side second mounting flange 86, and at one side of the secondary side branch path center connection SL. That is, the secondary side second lower mounting holes 100 and 102 are formed symmetrically with respect to the secondary side second center line SC2 that passes through the secondary side second center SO2 and is orthogonal to the secondary side branch path center connection line SL. The secondary-side second upper mounting hole 104 is formed on the secondary-side second centerline SC2 on the other side of the secondary-side branch path center connection SL, that is, on the upper side.

Second secondary side lower mounting holes 100, 102
Secondary-side second lower mounting bolts B-2a and B-2b are respectively inserted as secondary-side second lower-mounting tools into the secondary-side second upper-mounting holes 104. The secondary-side second upper mounting bolt B-2c is inserted as a tool.

The secondary side third mounting flange 88 is shown in FIG.
As shown in FIG. 6, the secondary side connecting flange 70 is located at the other end portion of the secondary side manifold main body 68. As shown in FIG. 6, the secondary side third mounting flange 88 has a secondary side third exhaust port hole 106 formed in the central portion thereof.
On one side of the secondary side branch path center connection SL, that is, at the lower side, symmetrically with respect to the secondary side third center line SC3 passing through the secondary side third center SO3 and orthogonal to the secondary side branch path center connection SL. The secondary side third lower mounting holes 108 and 110 are formed, and on the other side of the secondary side branch path center connection line SL, that is, at the upper side, the secondary side connecting flange more than the secondary side third center line SC3. Secondary side third upper mounting hole 1 separated by distance SD2 to 70 side
12 are formed.

The secondary side third lower mounting holes 106, 108
Secondary-side third lower mounting bolts B-3a and B-3b are respectively inserted as secondary-side third lower-mounting tools into the secondary-side third upper-mounting holes 112. As a result, the primary side third upper mounting bolt B-3c is inserted.

Next, the operation of this embodiment will be described.

For example, when the primary-side manifold body 20 of the primary-side exhaust manifold 18 is distorted by the heat of the exhaust gas, the primary-side manifold body 20 has independent primary-side first, second, and third mounting flanges 36, 38, 40, and at both ends of the primary-side manifold body 20, the primary-side first upper mounting bolt A-1a for mounting the primary-side first mounting flange 36 is attached to the end side of the primary-side manifold body 20. And the primary side third upper mounting bolt A-1c for mounting the primary side third mounting flange 40 is offset to the end side of the primary side manifold body 20, the primary side first and third mounting Flange 3
6 and 40 are not deformed so as to be separated from the primary side cylinder head 6, and the sealability of each primary side exhaust port portion can be secured.

Further, when the secondary side manifold body 68 of the secondary side exhaust manifold 66 is distorted by the heat of the exhaust gas, the secondary side manifold body 68 is independently attached to the primary side first, second and third mountings. It is supported by the flanges 84, 86, 88, and at both ends of the secondary-side manifold main body 68, the secondary-side first upper mounting bolt B-1a for mounting the secondary-side first mounting flange 84 is the secondary. It is offset to the end side of the side manifold main body 68, and the secondary side third upper mounting bolt B-1c for mounting the secondary side third mounting flange 88 is offset to the end side of the secondary manifold main body 68. Therefore, the secondary side first, second, and third mounting flanges 84, 88 are not deformed so as to be separated from the secondary side cylinder head 8, and the sealing property of each secondary side exhaust port portion is ensured. Door can be.

As a result, the primary side and secondary side exhaust manifolds 18, 66 are mounted in a good condition, and the primary side and secondary side exhaust manifolds 18, 66 are provided in order to secure the sealing property and prevent the exhaust gas from leaking. Since it is not necessary to change the shape of or the shape of each of the primary side and secondary side gaskets, there is no adverse effect on the layout, and it is possible to reduce the cost.

[0036]

As is apparent from the above detailed description, according to the present invention, each branch pipe connected in parallel to the manifold main body is provided with an independent mounting flange so that the manifold main body is provided at the end portion in the longitudinal direction. Even if the manifold body is distorted, each mounting flange can be deformed by installing the other side mounting tool for mounting the positioned mounting flange so that it is positioned closer to the end side of the manifold body than the center line of the branch path. There is no need to change the tightening points of the mounting flange, and it is possible to effectively prevent exhaust gas leakage, which eliminates the need to change the shape of the exhaust manifold and gasket and is advantageous in layout. It can be cheaper.

[Brief description of drawings]

FIG. 1 is a side view of a primary engine bank of a V-type engine.

FIG. 2 is a side view of a secondary engine bank of a V-type engine.

FIG. 3 is a side view of a primary side exhaust manifold.

FIG. 4 is an explanatory diagram showing an arrangement state of primary side first, second, and third mounting flanges.

FIG. 5 is a side view of a secondary side exhaust manifold.

FIG. 6 is an explanatory diagram showing an arrangement state of secondary side first, second, and third mounting flanges.

FIG. 7 is a side view of a conventional exhaust manifold.

FIG. 8 is an explanatory diagram showing an arrangement state of each mounting flange in the related art.

[Explanation of symbols]

 2 V-type engine 10 primary side engine bank 12 secondary side engine bank 18 primary side exhaust manifold 36 primary side first mounting flange 38 primary side second mounting flange 40 primary side third mounting flange 48 primary side first upper mounting hole 64 Primary-side third upper mounting hole 66 Secondary-side exhaust manifold 84 Secondary-side first mounting flange 86 Secondary-side second mounting flange 88 Secondary-side third mounting flange 96 Secondary-side first upper-mounting hole 112 Secondary-side Third upper mounting hole

Claims (1)

[Claims] 1. A manifold main body of each exhaust port of the engine, which is directed in a serial direction, and each branch passage communicating with each exhaust port, and each branch pipe connected in parallel to the manifold main body and fixed to the engine. An exhaust manifold provided with a mounting flange connected to each of the branch pipes is provided, and one side of the branch line central connection line that passes through each center of each branch line passes through the center of the branch line and the branch line center connection line. Exhaust in which the mounting flange is mounted on the engine by two one-sided fittings located substantially symmetrically with respect to a centerline perpendicular to the engine and one other-sided fitting located on the other side of the branch path center connection. In the pipe structure, each of the branch pipes is independently provided with each attachment flange, and the other side attachment for attaching the attachment flange located at an end portion in the longitudinal direction of the manifold body is provided with the branch passage. The exhaust pipe structure is provided so as to be located closer to the end portion side of the manifold body than the center line of the exhaust pipe structure.