JPS62182420A - Sintered type exhaust muffler - Google Patents

Abstract

PURPOSE:To aim at improvement in a frequency characteristic, by attaching a porous muffling material, made up of heating and fusing a fibriform muffling material, to an inner part of a muffler body. CONSTITUTION:The inside of a muffler body 1 is partitioned into small chambers 16 and 17, and an interval between these small chambers 16 and 17 is connected through a small hole. Porous muffling materials 13-15 are attached to an inner part of the muffler body 1. Stainless steel formed into fibriform in advance is stacked up and heated fused for several minutes at a temperature of 1,000 deg.C or so in a heating furnace, forming these porous muffling materials 13-15. A material is properly selected whereby porosity of the muffling material can be set to the desired value. With this constitution, the muffling material is formable as adjusted to frequency of a noise to be produced, so that a frequency characteristic is improvable.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an exhaust muffler that is attached to an internal combustion engine of an automobile or the like and attenuates exhaust noise while allowing exhaust gas from the internal combustion engine to pass through.

Conventional Technology In the case of a general internal combustion engine, when the exhaust valve opens, the gas inside the cylinder is released to the outside, but since this gas has a high pressure and temperature, if it is released directly into the atmosphere, it will suddenly explode. It expands and makes a loud noise. In order to eliminate such noise, a muffler, commonly called a muffler, is used to average pressure changes in the exhaust gas and release it into the atmosphere as a smooth airflow. FIG. 5 shows an example of the above-mentioned muffler M. In the figure, 1 is a muffler main body having a substantially cylindrical shape, and mirror plates 2a and 2b are fixed to both ends. A partition wall 3.4 is provided inside the muffler body 1.
is fixedly installed, and the interior of the muffler body 1 is partitioned into small chambers 5 and 6°7 by the partition wall 3°4. 8 is an input pipe, which passes through the end plate 2a and the partition wall 3, and
a and the partition wall 3. Exhaust gas is fed into the input pipe 8 from an internal combustion engine such as an engine (not shown). 9
10 is a small hole bored in the partition wall 3, 10 is a conduit connecting the small chambers 5 and 7, and 11 is an output pipe that is supported and fixed through the mirror plate 2b. Note that a large number of small holes may also be provided in the wall of the conduit 1o.

According to the above-mentioned silencer M, from the internal combustion engine (not shown) to the arrow A
The exhaust gas fed into the input pipe 8 expands when entering the small chamber 6, and similarly enters the small chamber 5 via the small hole 9, and then from the small chamber 5 to the small chamber 7 via the conduit 1o. Similarly, the high-pressure exhaust gas discharged from the internal combustion engine is gradually lowered and averaged, and is dissipated to the outside from the output pipe 11 as a smooth, approximately equal-pressure gas flow. This makes it possible to suppress the sounds of explosions such as

FIG. 6 shows a muffler N which is a modification of the above-described muffler M, and in the case of this example, a sound deadening material 12 mainly made of glass wool or rock wool, etc. is provided in the small chambers 5, 6.7.
12, 12t-filling and output pipe 11a'ft from chamber 5 to partition walls 3, 4. and is supported and fixed by penetrating the mirror plate 2b. Furthermore, the partition wall 4 has a small hole 4a.

4a is provided. Therefore, the exhaust gas sent from the input pipe 8 passes through the sound deadening materials 12, 12, 12 filled in the small chambers 6, 7°5 as shown by the arrow B, and each sound deadening material 1
2, and is emitted to the outside from the output tube 11 & while being subjected to vibration absorption and pressure averaging.

Problems to be Solved by the Invention However, such a conventional silencer M (Fig. 5) has the following problems:
Since it utilizes the expansion phenomenon when exhaust gas flows into the small chambers 5, 6.7, it has the effect of removing relatively low-level waves in the noise generated by the engine, but it does not completely remove high-frequency components. There is a drawback that it cannot be done. On the other hand, silencer N (6th
According to the example shown in Figure), the sound deadening material 12 such as glass wool, rock wool, or asbestos filled in the small chambers 5, 6.7 has the effect of removing high frequency components of gold in the noise, and the muffler M
The silencing effect can be improved compared to the above. However, on the other hand, since the sound deadening material 12 is easily damaged over time, there is a drawback that a portion of the sound deadening material 12 becomes powdered and dissipates during use. Particularly in the case of a car, since the car body vibrates, the sound deadening material 12 is accelerated to become powder, which tends to fly up into the atmosphere and become a source of pollution. Furthermore, there is another problem in that filling the sound deadening material 12't into the small chambers 5, 6.7 is difficult and requires much effort and time, resulting in a decrease in productivity.

Therefore, the present invention solves the problems of conventional exhaust mufflers for internal combustion engines, and provides a muffler that does not cause dissipation of the muffler, has good productivity, and has a high muffling effect. The purpose is to

Means for Solving the Problems In order to achieve the above object, the present invention heat-fuses a fibrous sound-deadening material inside a muffler body whose interior is partitioned into small chambers, thereby providing a predetermined sound-deadening material. The structure is equipped with or filled with a sintered porous sound deadening material that maintains a porosity of .

By making the porous sound deadening material sintered, it is extremely easy to install or fill it into the muffler body, and the porosity of the porous sound deadening material can be changed as desired.
Alternatively, by filling the muffler with sound deadening materials having different porosity, the frequency dependence of the muffler can be eliminated, making it possible to accommodate sound sources with a wide range of frequencies.

Embodiments Hereinafter, embodiments of a sintered exhaust silencer according to the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention, in which the same components as those of the conventional example shown in FIG. 3 are denoted by the same reference numerals. That is, the muffler 0 includes a muffler main body 1 having a substantially cylindrical shape, mirror plates 2m and 2b fixed to both parts of the muffler main body 10, and an input pipe 8. Output tube 11 t-
It is mainly composed of

Porous sound deadening materials 13, 14, and 15 manufactured by sintering are attached to the inside of this muffler body 1. The porous sound deadening materials 13 and 15 are formed in integral contact with the mirror plates 2a and 2b, respectively, and the porous sound deadening material 14 is formed to be located approximately at the center of the muffler body 1. The input tube 8 has a mirror plate of 2 m,
The porous sound deadening material 1 is inserted through the porous sound deadening material 13i.
4, and the output tube 11 is supported by the end plate 2.
b, is inserted through the porous sound deadening material 15, and the end is supported by the porous sound deadening material 14 as well. With the above configuration, the inside of the muffler main body 1 is partitioned into a small chamber 16 and a small chamber 17. The porous sound deadening material 14 is inserted into the small chamber 1.
6 and the small chamber 17.

The porous sound deadening materials 13, 14, and 15 described above are composed of the following compositions. That is, when fibrous stainless steel is deposited in advance and heated in a heating furnace at around 1000° C. for several minutes, a portion of the fibrous stainless steel is melted and fused together. Next, by cooling, a porous sound deadening material in which the fibrous stainless steel is fused together is obtained. The porous sound deadening material thus obtained is cut into a desired shape to form the porous sound deadening materials 13 and 14 described above.
, 15 can be obtained. Among the above-mentioned means, the mirror plate 2& is prepared in advance.

The porous sound deadening materials 13, 15'i may be obtained integrally with the end plates 2a, 2'b by heat-treating the stainless steel fibers 2b while being placed thereon.

Furthermore, it is also possible to obtain a porous sound deadening material by using spherical metal instead of fibrous stainless steel and subjecting it to similar heat treatment.

According to this configuration, exhaust gas sent from an internal combustion engine (not shown) via the input pipe 8 first expands when entering the small chamber 17 and collides with the porous sound deadening material 15, causing a resonance effect. Absorbs vibrations. This exhaust gas then passes through the porous sound deadening material 14 and enters the chamber 16, which also induces the same expansion and resonance effects as described above, and the porous sound deadening material installed in the chamber 16. It collides with the material 13, and the imaging and noise are absorbed.

In this way, the noise and vibration of the exhaust gas that has passed sequentially through the small chambers 17 and 16'i is absorbed, and the gas pressure is approximately equalized, so that the exhaust gas is discharged from the small chamber 16 to the outside via the output pipe 11. be able to. The first actual flow side described above is the most simplified example of the silencer itself, and when implemented, in addition to the small chambers 16 and 17, a plurality of small chambers are additionally formed, and the above-mentioned structure is formed between each small chamber. It is also possible to provide porous sound deadening material.

FIG. 2 shows a second embodiment of the present invention. In this embodiment, a porous sound deadening material 18 is attached to almost the entire inner wall surface of the muffler body 1 and end plates 2a and 2b, and the muffler body 1
A porous sound deadening material n, 22 having a different porosity from the porous sound deadening material 18 is placed in the small chambers 21 on both sides sandwiching the partition IIk19 provided approximately in the center of the partition wall 19 and the small hole 19m bored in the partition wall 19.
It is filled with. That is, by changing the length of the fibrous stainless steel material or the diameter of the spherical metal when manufacturing the porous sound deadening material, a sound deadening material having an arbitrary preset porosity can be obtained. Therefore, as in the second embodiment, by completely installing the porous sound deadening material 18 and the porous sound deadening material 22 having different porosity inside the muffler body 1, it is possible to absorb the frequency range in the noise emitted by the internal combustion engine. By expanding the range, a more accurate exhaust silencer can be obtained.

FIG. 3 shows a third embodiment of the present invention, in which porous sound deadening materials 23 and 24 are fixed to the inner walls of the input pipe 8 and the output pipe 11, respectively, in the first embodiment shown in FIG. It's Nishide. According to the third embodiment, the vibration and noise absorption effects can be further enhanced compared to the first embodiment.

FIG. 4 shows a fourth embodiment of the present invention, in which a connecting pipe connecting the muffler main body 1 and the internal combustion engine 5, and an inner wall of the exhaust pipe section that discharges exhaust gas from the muffler main body 1 to the outside. Each of the porous sound deadening materials has a fixed structure.

According to the fourth embodiment, it is possible to further increase the fixed area of the porous sound deadening material compared to the third embodiment, and it is possible to increase the effect of absorbing vibrations and noise caused by the explosion of the cuff and internal combustion engine. It becomes possible.

Effects of the Invention As explained in detail above, the sintered exhaust muffler according to the present invention has a porous structure formed by heating and fusing fibrous sound deadening material to maintain a predetermined porosity. Since the sound deadening material is installed or filled inside the main body of the muff 2, various effects described below can be achieved. In other words, when manufacturing a porous sound deadening material, it is possible to set the porosity of the finished porous sound deadening material to a desired value by appropriately selecting and processing the material, thereby improving frequency characteristics. . That is, it is not only possible to create a sound deadening material with a porosity most suitable for the frequency of noise generated by an internal combustion engine, but also to install a combination of sound deadening materials having different porosity.

In addition, the sound deadening material itself is made of heat-fused fibrous or spherical materials that are firmly bonded and fixed to each other, so it can be processed into any shape and can be installed inside the muffler body. And the workability at the time of filling is extremely good. Furthermore, since there is no risk of the sound deadening material being damaged over time, part of the sound deadening material is prevented from turning into powder and scattering during use. Therefore, the sintered exhaust silencer according to the present invention has excellent sound absorption properties, vibration isolation properties, and dirt scraping properties, and is highly effective in contributing to cost reduction.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment of a sintered exhaust silencer according to the present invention, FIG. 2 is a sectional view showing a second embodiment of the present invention, and FIG. 3 is a sectional view showing a third embodiment of the present invention. 4 is a sectional view showing a fourth embodiment of the present invention, FIG. 5 is a sectional view showing an example of a conventional muffler, and FIG. 6 is a sectional view showing another example of a conventional muffler. It is a diagram. 1... Muffler body, 2a, 2b... Mirror plate, 8...
・Input tube, 11...Output tube, 13, 14, 15
, 18 , 22 , Z3 , 24 . Measurement, 29... Porous sound deadening material, 16, 17, 20
, 21...small chamber, 5...internal combustion engine, ga...connecting pipe, n...exhaust pipe.

Claims (1)

[Claims] (1) The inside of the muffler main body having a substantially cylindrical shape is partitioned into small chambers, each of the small chambers is connected through a small hole, and the exhaust gas generated from the internal combustion engine is sequentially communicated with each of the small chambers, so that the internal combustion engine In an exhaust muffler designed to muffle exhaust noise caused by an explosion, a fibrous sound deadening material is heated and fused inside the muffler body to maintain a predetermined porosity. A sintered exhaust muffler characterized by being equipped with or filled with a porous sound deadening material.