JP2970230B2 - Dual exhaust pipe for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual exhaust pipe for a vehicle, which can be applied to a so-called FF type automobile to obtain good effects.

[0002]

2. Description of the Related Art In an exhaust manifold and an exhaust pipe of a multi-cylinder engine, a branch pipe is sequentially connected to an exhaust port of each cylinder in order to avoid an exhaust interference between the cylinders, and exhaust gases flowing through each branch pipe merge. It has such a configuration (see Japanese Patent Application Laid-Open No. 57-46011 and Japanese Utility Model Application Laid-Open No. 60-32519). This will be described with reference to FIG. In FIG. 3, reference numeral 1 denotes an exhaust manifold, which is attached to a cylinder block of an engine having a plurality of cylinders (not shown).

The structure of the exhaust manifold 1 includes a flange 2
The first, second, third and fourth branch pipes 3, 4 from the left
5,6 proximal end is attached to, the 1st and 4th branch pipes 3,6
The distal ends are connected, and the distal ends of the second and third branch pipes 4 and 5 are connected to each other and attached to a flange 7 formed in two rows . With this structure, when the ignition timings are in the order of cylinder numbers 1, 3, 4, and 2, they do not interfere with each other.

[0004] A flange 8 of substantially the same shape faces the flange 7.
The flange 8 is provided with first and second intermediate exhausts.
The holes 11, 12 proximal end mounted in the tube 9, 10, the branch pipe 3,
The exhaust from the 4, 5, and 6 sides is received. No.
The first and second intermediate exhaust pipes 9 and 10 are connected to each other at a junction 13 and a single exhaust pipe 14 leads to a catalytic converter and a muffler (not shown). In the case of this structure, if the first and second intermediate exhaust pipes 9 and 10 do not have a certain length or more, exhaust interference occurs. Branch pipe 3,
Increasing the length to the junction of 4, 5, and 6 is effective in suppressing exhaust interference.

By the way, the engine is arranged at the front of the vehicle body,
In a so-called FF type vehicle in which the front wheels are driven, the first and second intermediate exhaust pipes 9 and 10 are layout-wise.
Is passed between the oil pan and the engine mount member, which makes it difficult to secure space. Also, each
It is difficult to make the branch pipes 3, 4, 5, 6 equal in length due to the layout of the branch pipes 4, 5. Therefore, the first and second
In the case where sufficient space cannot be secured in the portion of the second intermediate exhaust pipes 9 and 10, as shown in FIG. 4, the two intermediate exhaust pipes 9 and 10 are replaced with one intermediate exhaust pipe 15 (FIG. 5). See).

[0006]

[0006] However, in this way the exhaust pipe 15 and only one, it is likely to occur inevitably exhaust interference, power-up would not be expected. If a sufficiently space take, as shown in FIGS. 6 and 7, the two it is conceivable to Haisuru intermediate exhaust pipes 9, 10 to the horizontal, in this case, each intermediate exhaust
In order to make the lengths of the pipes 9 and 10 equal, the branch pipes 4 and 5 need to be greatly expanded forward, and the protruding length α of the engine 16 from the center of the crank pulley 18 increases, which is disadvantageous in layout. become. The prior art described above cannot solve this problem because of its different configuration. 4 and 6, reference numeral 18 denotes a cylinder block;
Is an oil pan.

An object of the present invention is to provide a dual exhaust pipe for a vehicle which solves such a problem of the conventional exhaust pipe.

[0008]

According to the present invention, as a means for solving the above problems, a plurality of downwardly extending branch pipes are provided.
Have the proximal end of each branch pipe in front of the engine by a flange
A connected exhaust manifold and a branch of the exhaust manifold;
Connected to the end of the pipe via a flange formed in duplicate
First and second intermediate exhausts disposed below the engine
Connected to the pipe and the first and second intermediate exhaust pipes via a junction
And a single exhaust pipe extending rearward.
And the middle exhaust pipe are two exhaust passages with different lengths
And a long first cylinder connected to the end cylinder of the engine.
The branch pipe is connected to the short first intermediate exhaust pipe and is located inside the engine.
A short second branch connected to the central cylinder is a long second intermediate exhaust.
And the second intermediate exhaust pipe is connected to the trachea.
The first intermediate exhaust pipe extends downward and is disposed
The first branch pipe connected to the end cylinder and the first branch pipe connected thereto
A first intermediate exhaust pipe and a second branch pipe connected to the central cylinder
And the second intermediate exhaust pipe connected to each
The length is made equal .

[0009]

With this configuration, the exhaust gas discharged from the cylinder of the engine is divided into two cylinders, each of which joins the two branch pipes . Middle
Although flow into the exhaust pipe will be directed to the catalytic converter and the muffler side, since the two intermediate exhaust pipes are disposed so as to be oblique or vertical to each other, the intermediate exhaust
The length of this portion of the tube changes, which in turn adds to it, so that the length of the branch can be changed so that forward bulging can be reduced.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In the present invention, the first and second intermediate exhausts to which the branch pipes 3 to 6 of the exhaust manifold 1 are connected.
The trachea 9 and 10 are arranged obliquely to each other, and the length of the two intermediate exhaust pipes 9 and 10 is changed. First, second
The direction of the intermediate exhaust pipes 9 and 10 should not be slanted in this way.
The book may be stacked, that is, arranged vertically. In short, the same operation and effect can be obtained as long as the two lines are not arranged horizontally.

[0011] The dual exhaust pipe thus configured
IsFirst and second intermediate exhaust pipes9 and 10 slant each other
(Or vertical)
ByIntermediate exhaust pipeSince the length of 9, 10 can be changed,No.
The length of the first intermediate exhaust pipe 9Only the second and thirdBranch pipe
It becomes possible to shorten the pipe length of 4,5. By this
No. 1Branch pipeTo 3Second intermediate exhaust pipe10 plus length, 4
Number oneFirst intermediate exhaust pipe in branch pipe 610 plus
Branch pipeTo fourFirst intermediate exhaust pipe9 plus length and number 3
ofBranch pipeTo 5First intermediate exhaust pipeAll of the length plus 9
Can be identical. ThereforeUniform exhaust efficiency
So the enginePower up can be achieved
Will be. Projection length from the center of the crank pulley 18
Is the protruding length α of the same part of the conventional example shown in FIG.
The overall length of the engine assembly.
Will be.

[0012]

Since the present invention is a dual exhaust pipe for a vehicle configured as described above, an exhaust manifold is provided.
Connected to the central cylinder of the engine out of the branches
By shortening the length of the thing inside the engine room
Reduce the amount of forward protrusion of the branch pipe of the engine mounted on the
And space efficiency can be improved. And
This part moves the second intermediate exhaust pipe connected to it downward.
Connecting to an intermediate exhaust pipe that has been extended to make it longer
The branch pipe connected to the end cylinder of the engine
It can be the same length as the intermediate exhaust pipe connected to it.
Exhaust efficiency changes between cylinders by making them equal length
There is no. Therefore, it is possible to obtain a layout that satisfies the engine performance while increasing the space efficiency in the FF type vehicle in which the free space in the engine room is particularly small. Further, when the exhaust manifold is formed by casting, the excess wall thickness is reduced, and the material, the weight, and the size of the mold are reduced.

[Brief description of the drawings]

FIG. 1 is a side view of one embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view showing a conventional exhaust manifold and an exhaust pipe.

FIG. 4 is a side view showing another example of a conventional exhaust manifold and an exhaust pipe.

FIG. 5 is a sectional view taken along the line BB of FIG. 4;

FIG. 6 is a side view showing still another example of the conventional exhaust manifold and exhaust pipe.

FIG. 7 is a sectional view taken along the line CC of FIG. 6;

[Explanation of symbols]

Reference Signs List 1 exhaust manifold 3 branch pipe 4 branch pipe 5 branch pipe 6 branch pipe 9 first intermediate exhaust pipe 10 second intermediate exhaust pipe 15 exhaust pipe

Claims (1)

(57) [Claims] A plurality of branch pipes extending downward;
With the base end connected to the front of the engine by a flange.
Gas manifold and the tip of the branch pipe of the exhaust manifold.
The engine is connected via a flange formed in two rows.
First and second intermediate exhaust pipes disposed below the
1, connected to the second intermediate exhaust pipe via a junction, and
An exhaust pipe extending from the branch pipe and the intermediate exhaust pipe.
The pipes form two exhaust passages of different lengths,
The long first branch connected to the end cylinder of the engine is short
Connected to the first intermediate exhaust pipe and connected to the central cylinder of the engine
Connected short second branch to long second intermediate exhaust
And the second intermediate exhaust pipe is connected to the first intermediate exhaust pipe.
The end cylinder is disposed so as to protrude downward with respect to the exhaust pipe.
First branch connected to the first branch and the first intermediate connected thereto
The exhaust pipe and the second branch pipe connected to the central cylinder and the
Equal length of each connected second intermediate exhaust pipe to each junction
A dual exhaust pipe for vehicles, characterized in that: