JPS5893921A - Exhaust device - Google Patents

Abstract

PURPOSE:To obtain a prescribed silencing effect in an exhaust pipe without causing the necessity for using a silencer, by mutually arranging the pipe in parallelly branching plural systems further providing both confluent parts in suitable parts and acoustic absorptive chambers in suitable parts of branch exhaust pipes. CONSTITUTION:An exhaust device 2 is equipped with a catalytic converter 4 in its head part, and two branch exhaust pipes 5, 6 parallelly extended to the tail end are connected to the converter. Confluent pipes 7, 8 are provided in two parts on the half way of said exhaust pipes 5, 6, while acoustic absorptive chambers 9, 10 are zigzag arranged in the pipes 5, 6 between the pipes 7, 8. Here the chamber 9, 10 is partitioned by inserting a small contour pipe 12 equipped with many small holes 11 throughout the overall length into the pipe 5, 6. An acoustic absorptive material 16 of glass material or the like is housed in the chamber 9, 10 through a foaming metal 15 wound to the peripheral wall of the pipe 12 to obtain a prescribed acoustic absorptive effect.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exhaust system that allows an exhaust pipe to perform a predetermined silencing function without installing a muffler.

As is well known, in recent years, automobiles have been fitted with air-conditioning and heating equipment, while also being forced to pursue improved maneuverability, increased interior space, and even progressively updated styling, and this situation is becoming more and more prevalent. .

Under these circumstances, these areas are becoming more and more complicated, especially around the engine S room and chassis, but with exhaust systems installed in the chassis,
Because it has to be incorporated into that complex uneven surface,
The situation is extremely difficult to install.

The most difficult problem in installing an exhaust system is how to fit one of the components, such as a muffler such as a main muffler, a bridge muffler, or a post muffler.

In other words, it is not enough to simply incorporate a silencer into the exhaust system, but it is also important to consider the effective position ("Optimum installation position and required noise reduction performance of an expansion type silencer" published in Journal of the Acoustical Society of Japan, Vol. 35, No. 6, pages 322-332). However, since it has a large diameter and long length, it is difficult to fit it into a complex uneven surface, so it is difficult to incorporate it into an effective position. It becomes impossible and will be incorporated in a position where momentum can be installed.

On the other hand, due to the above-mentioned installation problem, the muffler structure is becoming more complex because of the attempt to maximize the muffling performance at the installation location, which is actually going against the trend of weight reduction, cost reduction, and compactness.

Therefore, the present invention provides an exhaust system that has a simple structure and can solve the above-mentioned problems all at once.

Embodiments of the present invention will be described below with reference to FIG.

In the figure, 1 is an engine, and 2 is an exhaust system connected to an exhaust manifold 3 installed in the engine 1.

This exhaust device 2 has a catalytic converter 4 at the head, and two parallel branch exhaust pipes 5° and 6 are connected to the catalytic converter 4 up to the tail end. Merging pipes 7 and 8 are provided at two locations in the middle of each of the branch exhaust pipes 5 and 6, separated by a predetermined distance, and the two branch exhaust pipes 5 and 6 are connected to each other at the merging pipes 7 and 8. There is. Further, sound absorption chambers 9 and 1 are provided in the portion of the branch exhaust pipe 5 sandwiched between the merging pipes 7 and 8, and in the rear portion of the connecting portion of the merging pipe 8 of the branch exhaust pipe 6, respectively.
0 is set. As shown in FIGS. 2 and 3, the sound absorption chambers 9 and 10 are small diameter pipes in which a large number of small holes 11 are formed in the peripheral wall over the entire length inside the branch exhaust pipe 5 (or 6). 12 is inserted so that the flanges 13 and 14 at both ends are tightly joined to the inner peripheral surface of the branch exhaust pipe 5 (or 6), thereby making the gap between the branch exhaust pipe 5 (or 6) and the small diameter pipe 12 sound absorbent. They are in rooms 9 and 10. 1, the inside of the small diameter pipe 12 is used as an exhaust gas flow path. A sound absorbing material 16 such as a glass wool material is housed in the sound absorbing chambers 9 and 1o via a foamed metal 15 that is wound around the circumferential wall of the small diameter pipe 120. Note that the foamed metal 15 may not be provided.

According to the exhaust system 2 of this embodiment, the exhaust gas discharged from the exhaust manifold 3 by the drive of the engine 1 is purified by the catalytic converter 4, and then diverted to the branch exhaust pipe 5. branch exhaust pipe 5,
6 and is discharged to the outside. Exhaust gas flowing through the branch exhaust pipes 5 and 6 is attenuated in the interference region 3 in the respective merging pipes 7 and 8, and is absorbed and attenuated in the sound absorption chambers 9 and 10.
Ultimately, these effects attenuate sound waves in the low to high frequency range.

Although the sound absorption chambers may be provided throughout the branch exhaust pipes 5 and 6, it is effective to arrange them alternately as shown in the example.

In summary, the exhaust system according to the present invention branches an exhaust pipe into a plurality of systems from its head or midway, and these branched exhaust pipes are arranged in parallel with each other, and have a merging part at an appropriate location, and at the same time Since the structure is such that a sound absorption chamber is provided at the appropriate location of the branch exhaust pipe, when exhaust gas flows inside this device, the sound waves are attenuated by interference (low frequency to sound waves in the mid-frequency range),
The sound absorption chamber absorbs and attenuates (sound waves in the medium to high frequency range) and attenuates the sound waves in the low to high frequency range.In the end, this device itself performs the muffling function, so it is necessary to install a muffler. No longer needed. Therefore, since no muffler is installed, the muffler can be easily incorporated into the complex uneven surface of the ear 7 portion, and at the same time, the muffling effect can be maximized. In addition, in the exhaust system of the present invention, since the exhaust gas flows through the plurality of branch exhaust pipes, the pressure loss is reduced to d], and the noise generated by the airflow at the discharge portion is reduced.

Furthermore, since it includes a muffler, it has the effect of reducing air flow noise generated inside the exhaust system.

Fig. 4 shows a different embodiment, in which this exhaust system is composed of one system, and the flow path from the waist to the rear is made into two systems with branch exhaust pipes 5 and 6, and the branch exhaust pipes are also the same as in the above embodiment. The action is performed.

[Brief explanation of drawings]

The drawings show an embodiment of the invention, with FIG. 1 being a schematic side view;
FIG. 2 is an enlarged longitudinal sectional side view of the sound absorption chamber portion, FIG. 3 is an enlarged longitudinal sectional front view of the same, and FIG. 4 is a schematic side view of a different embodiment. Patent applicant: Japan Radiator Co., Ltd.
Attorney Patent Attorney Fumi Furuya 7-

Claims (1)

[Claims] Branching the exhaust pipe into multiple systems from the head or midway,
An exhaust system characterized in that these branch exhaust pipes are arranged in parallel with each other and have a merging portion at a proper location, and at the same time a sound absorption chamber is provided at a proper location of any of the branch exhaust pipes.