JPH0299711A - Muffler - Google Patents

Abstract

PURPOSE:To make it possible to reduce the size of a muffler as far as feasible and improve muffling effect of each component by making the first and the second exhaust tubes communicate with each other through a communicating tube equipped with a muffling element at the front wash side of a main muffler. CONSTITUTION:In a multicylinder V-type engine 12, exhaust gas discharged from exhaust manifolds 14 and 16, respectively, is led to a main muffler 30 installed at the end of a back wash side through exhaust tubes 18 and 20 of two lines. Then, a communicating tube 34 is connected between center tubes 18b and 20b at the front wash side of the exhaust tubes 18 and 20, and the exhaust tubes 18 and 20 are communicated with each other at the front wash side of the main muffler 30 through the communicating tube 34. Next, a resonator 36 as a muffling element, is installed at the central part of the communicating tube 34. Thereby, it is possible to remove difference tones of the right and left fundamental degree sound pressure propagated in the exhaust tubes 18 and 20, so that it is possible to prevent the main muffler from becoming large in size as a single.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to a method in which exhaust gas discharged from the left and right exhaust manifolds of a multi-cylinder type engine is passed through two exhaust tubes connected to the left and right exhaust manifolds, respectively. This relates to an exhaust silencer that is guided by a muffler.

Conventional technology In a multi-cylinder ■ type engine, multiple cylinder rows on one side are arranged in a ■ shape (opposed type is also included) around the crankshaft, and each cylinder row on one side has a cylinder row. Exhaust gas is collected by an exhaust manifold having branch sections, and the collected exhaust gas is directed to a muffler via an exhaust tube.

By the way, the above-mentioned exhaust manifolds are respectively provided for each of the left and right cylinder rows that are shaped like a single character, and the above-mentioned exhaust tubes are connected to the left and right exhaust manifolds, respectively.

Therefore, when connecting exhaust tubes to the left and right exhaust manifolds, for example,
') MERCEDES-BENZ force 9og C" (
As disclosed on pages 72 and 74 (TYP280SL/St, C, 350SL/Sl, C, etc.), two exhaust systems are configured using two exhaust tubes.

By the way, when two exhaust tubes are provided in this way, by making these two exhaust tubes communicate with each other via a communication pipe, as shown in FIG. Order sound pressure P, Q
can be reduced by canceling each other out.

Problems to be Solved by the Invention However, although providing the above-mentioned communication pipes is an effective means for reducing the basic order sound pressures P and Q of the explosion in the left and right cylinder rows, there are As a difference sound between the fundamental order sound pressures P and Q, a high frequency sound R (third order component) is generated as shown in FIG. 4 above.

Therefore, in order to remove the high-frequency sound R generated in the communication pipe, it is necessary to significantly increase the capacity of the muffler, that is, the exhaust silencer, on the downstream side of the communication pipe. The problem was that it became too narrow.

SUMMARY OF THE INVENTION In view of these conventional problems, it is an object of the present invention to provide an exhaust silencing device that can significantly improve the silencing effect of each component while minimizing the size of the device.

Means for Solving the Problems In order to achieve the above object, the present invention provides two systems, the first and second exhaust manifolds, which are respectively connected to the left and right exhaust manifolds of a multi-cylinder type engine. A second exhaust tube is provided to direct exhaust gases discharged from the first and second exhaust manifolds, respectively. In the exhaust silencing device that leads to the main muffler provided at the downstream end via the second exhaust tube, the first. The second exhaust tubes are configured to communicate with each other via a communication pipe on the upstream side of the main muffler, and the communication pipe is provided with a muffling element.

Effects With the above-described configuration, the exhaust silencing device of the present invention has the following features: By providing a silencing element in the communication pipe that communicates with the second exhaust tube, the first. The muffling element can be used exclusively to eliminate the difference sound between the left and right fundamental order sound pressures propagated through the second exhaust tube.

Therefore, the above-mentioned silencing element only needs to remove sound pressure in a specific frequency range, and the silencing element Lj body can be formed with a smaller size, thereby preventing the main muffler provided on the downstream side from increasing in size. In combination with this, it is possible to effectively muffle the left and right fundamental order sound pressures and the difference sound between them, while suppressing a significant increase in the size of the exhaust muffling device.

Example Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 shows an exhaust silencer 10 showing one embodiment of the present invention.
The exhaust silencer lO is connected to the left and right exhaust manifolds 1.4.16 of the type 1 multi-cylinder engine 12.

The engine 12 is configured as a type 6 cylinder, and each of the left and right cylinders of the engine 12 has fly fH14a, 16 of the left and right exhaust manifold I4.16.
a is connected, and the exhaust gas of the engine 12 is collected in the exhaust manifold 4 for those in the left cylinder row,
The cylinders in the right cylinder row are collected in the exhaust manifold 16.

1. The exhaust silencer 10 includes first and second exhaust tubes 18.20 connected to the left and right exhaust manifolds 14.16, respectively. Two exhaust systems are configured by the second exhaust tubes 18 and 20.

Above 1. The second exhaust tube 18.20 is provided with a catalyzer 22.24 and a sub-muffler 26.28, respectively, from the front side (left side in the figure) to the downstream side (right side in the figure). 1゜Second exhaust tube 18.20
A main muffler 30 is provided at the gathering part of the downstream end, and a tail tube 3 connected to the main muffler 30 is provided.
2, the exhaust gases are discharged to the outside.

And the above 1. The second exhaust tube I8, 20 has a front tube 18a on the upstream side of the characterizer 22.24.
, 20a, and the space between the catalytic converter 22.24 and the sub-muffler 26.28 is the front center tube 1.
8b, 20b, and a downstream center tube 18c between the sub muffler 26.28 and the main muffler 30,
It is said to be 20c.

The sub-mufflers 26 and 28 are configured to be relatively small as expandable mufflers, and the front center tubes 18b and 28 are
0b to the sub muffler 26. The exhaust pressure introduced into 28 is expanded and muffled within the sub-muffler 26.28,
The exhaust gas in the sub-mufflers 26, 28 is discharged to the downstream center tubes 18c, 20c.

Further, the main muffler 30 has a function of mainly muffling exhaust noise, and has an expansion chamber, a resonance chamber, etc. separated therein, and the exhaust sound is finally muffled within the main muffler 30.

Here, in this embodiment, the above-mentioned 1. Upstream center tubes 18b, 20b of the second exhaust tube 18.20
A communication pipe 34 is connected between them, and the first
．． The second exhaust tubes 18 and 20 communicate with each other on the upstream side of the main muffler 30.

A resonator 36 as a muffling element is provided at the center of the communication pipe 34.

The resonator 36 is composed of a resonance pipe 36a connected to the communication pipe 34, and a resonance box 36b connected to the tip of the resonance pipe 36a. The difference sound of the fundamental order sound pressure generated in the manifolds 14 and 16 should be silenced (tuned).

In the exhaust silencer 10 of this embodiment with the above configuration, the exhaust gas discharged by the operation of the engine 12 is
From left and right exhaust manifold 14°16 to 1st. Second
The exhaust noise is emitted outward through the exhaust tube 18.20, and the exhaust noise at this time is muffled through the sub-muffler 26.28 and the main muffler 30.

Also, the above 1. Since the second exhaust tubes 18.20 communicate between the front center tubes 18b and 20b via the communication pipe 34, the left and right exhaust manifolds 1
The fundamental order sound pressures P and Q (see FIG. 4) generated at 4.16 are canceled by the communication pipe 34 portion.

At this time, the left and right fundamental order sound pressure () is applied to the communication pipe 34.
, Q (see FIG. 4) is generated, but this difference tone R is effectively muffled by the resonance action of the resonator 36.

Therefore, the effect of the difference sound R does not remain on the downstream side of the communication pipe 34, and the corresponding high-frequency sound is removed from the exhaust sound, and the main muffler 30 is enlarged in order to remove the difference sound R. be prevented from being

Note that the resonator 36 is provided for the purpose of muffling the difference sound R, and since it is sufficient to muffle the sound in a specific high frequency range, the resonator 36 is used as a small muffler in conjunction with the main muffler 30. Or the above sub-muffler 26.
Since it can be provided independently from 28, the layout in the narrow mounting space at the lower part of the vehicle body is significantly simplified.

FIG. 2 shows another embodiment, in which the same components as in the first embodiment are given the same reference numerals and redundant explanations will be omitted.

That is, the exhaust silencer 10a of this embodiment has a communication pipe 34 connected between the upstream center tubes 18b and 20b.
In addition, a communication pipe 40 is also connected between the downstream center tubes ISC and 2OC, and the central parts of these two speed communication pipes 34 and 40 are communicated via an auxiliary pipe 42, and the middle part of the auxiliary pipe 42 is An expansion box 44 is provided as a sound deadening element.

Therefore, in this embodiment, the expansion box 44 functions as an expansion type muffler, and the noise generated in the two-speed communication pipes 34, 40 is suppressed.
Front center tube 18b.

20b and downstream center tube 18c.

The sound pressure difference between 20c and 20c is effectively muffled by the expansion box 44.

FIG. 3 shows still another embodiment, in which the same components as in each of the above embodiments are given the same reference numerals and redundant explanations will be omitted.

That is, the exhaust silencer 10b of this embodiment includes a communication pipe 34 between the upstream center tubes 18b and 2Ob, and a silencing element provided in the communication pipe 34 and the left and right submufflers 26, 28 shown in each of the above embodiments. and one collective muffler 5
It is configured as 0.

In other words, the collective muffler 50 has three first mufflers in the exhaust flow direction. Second. Third compartment 50a, 50b.

50C, the front center tubes 18b and 20b are communicated with the first partition chamber 50a, and the auxiliary pipe 52 connected to the center of the communication pipe 34 is connected to the second partition chamber 50b. The second compartment 50b is used as the silencing element, and the third compartment 50C is connected to the short pipe 54.
It communicates with the first partition chamber 50a via 54a.

The second compartment 50b and the third compartment 5
0C is connected to the main muffler 30 via the auxiliary pipe 52a and the downstream center tubes 13c and 20C.

Therefore, in this embodiment as well as in each of the above embodiments,
The difference sound R between the left and right fundamental order sound pressures P and Q can be removed.

As described in detail, in the exhaust silencer of the present invention, the fundamental order sound pressure generated in the left and right exhaust manifolds of a multi-cylinder type engine is transmitted through two systems connected to the left and right exhaust manifolds, respectively. 1st. They cancel each other out through the communication pipe that communicates the second exhaust tube, thereby achieving a significant reduction in the fundamental order sound pressure, and the difference sound between the left and right fundamental order sound pressures generated in the communication pipe. The high frequency sound appearing as a noise can be removed by a silencing element provided in the communication pipe.

Therefore, the above 1. There is no need to add the above-mentioned differential noise removal function to the main muffler provided at the downstream end of the second exhaust tube, and it is possible to prevent the main muffler from becoming large in size.

In addition, the above-mentioned silencing elements only need to exhibit a silencing function in a specific frequency range, and because they can be made smaller, they can be easily laid out even in narrow spaces under the vehicle body. Each supplement has excellent effects.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, FIG.
FIG. 3 is a schematic configuration diagram showing other embodiments of the present invention, and FIG. 4 is a sound pressure characteristic diagram of order components generated in two systems of exhaust tubes and a communicating pipe between these exhaust tubes. 10.10a,]]0b---Exhaust silencer 12-...
Engine, 14.16, pot, exhaust manifold,
18.20...Exhaust tube, 26.28...Sub muffler, 30...Main muffler, 34.40...Communication pipe, 36...Resonator (silence element), 44...
Expansion box (silence element), 50b... second partition (silence element).

Claims (1)

[Claims] (1) Two systems of first and second exhaust tubes are connected to the left and right exhaust manifolds of a multi-cylinder V-type engine, and the exhaust gas discharged from the exhaust manifolds is transferred to the first and second exhaust tubes. In the exhaust silencer, the first and second exhaust tubes are connected to each other on the upstream side of the main muffler via a communicating pipe, and the communicating pipe is connected to the exhaust pipe. An exhaust muffling device characterized in that a muffling element is provided in the exhaust muffling device.