JP4477781B2 - Silencer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention mainly relates to a silencer interposed in an exhaust system of a fuel cell vehicle, and more particularly to a sound absorbing silencer.
[0002]
[Prior art]
A conventional sound absorbing silencer is made by passing an inner pipe having a large number of through holes in a peripheral wall portion into a cylindrical silencer body, and a sound absorbing material such as glass wool in the space between the silencer body and the inner pipe. It is constituted by filling.
[0003]
[Problems to be solved by the invention]
When the above sound absorbing silencer is interposed in the exhaust system of the fuel cell vehicle, the following problems occur. That is, the exhaust gas of the fuel cell vehicle is water vapor generated when electric energy is generated from hydrogen and oxygen, and water accumulates at the bottom of the silencer body. In the conventional sound absorbing silencer, since the sound absorbing material is filled up to the bottom, the water accumulated in the bottom is sucked up by the capillary phenomenon, and water is contained in the entire sound absorbing material. When the sound-absorbing material absorbs water in this way, the air layer between the fibers of the sound-absorbing material disappears, so that the sound deadening performance is lowered.
[0004]
Even when a conventional sound absorbing silencer is interposed in the exhaust system of a vehicle that uses an internal combustion engine as a power source, if the vehicle is cruised at an extremely low temperature of minus 30 to 40 ° C., Water may condense in the silencer and cause the same problems as described above.
[0005]
In view of the above points, an object of the present invention is to provide a silencer that can prevent a decrease in the silencing performance due to water absorption of the sound absorbing material.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention, the inner space of the silencer body, by the specification Setsuban, divides an upper acoustic chamber filled with sound absorbing material, on the lower side of the expansion chamber, the sound absorption a gas inlet to the chamber, and a gas outlet provided in the expansion chamber, wherein the partition plate, wherein the communication hole for communicating with the lower side of the expansion chamber and the upper acoustic chamber is provided.
[0007]
Even if the gas introduced into the sound absorption chamber contains a large amount of moisture, the moisture falls to the lower expansion chamber through the communication hole of the partition plate due to the gas pressure. Further, since the water that has fallen into the expansion chamber is discharged together with the gas from the expansion chamber, the water does not accumulate so as to reach the partition plate in the expansion chamber, and the sound absorbing material in the sound absorption chamber does not suck up the water. Therefore, it is possible to effectively suppress the sound absorbing material from absorbing water, and the deterioration of the sound deadening performance due to water absorption is prevented.
[0008]
Further, if the gas inlet is constituted by a conduit extending to the expansion chamber via the sound absorption chamber, and if a large number of through holes are formed in the peripheral wall portion of the conduit, the gas pressure is more effectively applied to the sound absorbing material, Water contained in the sound absorbing material can also be efficiently dropped into the expansion chamber by the gas pressure, and further, a high-speed gas flow does not directly hit the sound absorbing material, and a reduction in the sound deadening performance due to scattering of the sound absorbing material is prevented.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, reference numeral 1 denotes a silencer interposed in an exhaust system of a fuel cell vehicle, and exhaust gas (water vapor) from a fuel cell (not shown) is sent to an upstream exhaust pipe 2 and a silencer 1. And the downstream exhaust pipe 3 to the atmosphere.
[0010]
As shown in FIGS. 2 to 4, the silencer 1 is disposed in a silencer body 4 that is horizontally long and includes a cylindrical shell 4 a and end plates 4 b and 4 c that close one end and the other end. The horizontal partition plate 5 provided is provided, and the partition plate 5 divides the internal space of the silencer body 4 into two upper and lower chambers. The upper chamber is configured as a sound absorbing chamber 7 filled with a sound absorbing material 6 such as glass wool, and the lower chamber is configured as an expansion chamber 8. A number of communication holes 5a are formed in the range of the partition plate 5 surrounded by the line a in FIG.
[0011]
In the sound absorption chamber 7, a conduit 9 serving as a gas inlet connecting the upstream exhaust pipe 2 is disposed, and in the expansion chamber 8, a conduit 10 serving as a gas outlet connecting the downstream exhaust pipe 3 is disposed. In detail, the upstream end of the conduit 9 disposed in the sound absorbing chamber 7 is fitted and welded to the upper portion of the end plate 4b at one end of the silencer body 4, and the upstream exhaust pipe 2 is connected to the upstream end. At the same time, the downstream portion of the conduit 9 is bent downward and fitted and welded to a portion near the other end of the partition plate 5, so that the downstream end of the conduit 9 communicates with the expansion chamber 8. And many through-holes 9a are formed in the surrounding wall part of the conduit | pipe 9, and the sound-absorbing effect by the sound-absorbing material 6 is given to exhaust gas through these through-holes 9a.
[0012]
Further, the downstream end of the conduit 10 disposed in the expansion chamber 8 is fitted and welded to the lower part of the end plate 4c at the other end of the silencer body 4, and the downstream exhaust pipe 3 is connected to the downstream end. The upstream end of the conduit 10 is opposed to the end plate 4b at one end of the silencer body 4 with a gap, and a large number of through holes 10a are formed in the peripheral wall portion of the upstream portion of the conduit 10 to expand the expansion chamber 8. The exhaust gas inside flows into the conduit 10 through the gap and the through hole 10a and is discharged into the atmosphere through the conduit 10 and the downstream exhaust pipe 3.
[0013]
In addition, the partition plate 5 is welded to the upper surface of the conduit 10 at three locations in the longitudinal direction, and a bracket 5b is erected in the vicinity of one end of the upper surface of the partition plate 5, and a portion near the upstream end of the conduit 9 is provided on the bracket 5b. Further, the downstream end of the conduit 9 is fitted and welded to the vicinity of the other end of the partition plate 5 as described above, and the conduits 9 and 10 and the partition plate 5 are integrally connected to each other. The partition plate 5 is supported in a suspended state in the silencer body 4 by fitting and welding the upstream end of the conduit 9 and the downstream end of the conduit 10 to the end plate 4b at one end and the end plate 4c at the other end, respectively. Like that.
[0014]
According to the above configuration, even when the water vapor as exhaust gas from the fuel cell diffuses into the sound absorbing chamber 7 through the through hole 9a of the conduit 9, and the sound absorbing material 6 contains water, this water passes through the through hole 9a. The gas pressure acting on the sound absorbing material 6 falls into the expansion chamber 8 through the communication hole 5a of the partition plate 5. Then, the water that has fallen into the expansion chamber 8 is sequentially discharged to the outside through the conduit 10, and water does not accumulate in the expansion chamber 8 so as to reach the partition plate 5. Therefore, the sound absorbing material 6 in the sound absorbing chamber 7 does not suck up water, and a reduction in noise reduction performance due to water absorption is prevented.
[0015]
Further, when a high-speed exhaust gas flow directly hits the sound absorbing material 6, the fibers of the sound absorbing material 6 may be loosened, and the fibers may be scattered to the outside from the communication holes 5 a of the partition plate 5 through the expansion chamber 8. In the present embodiment, since the sound absorbing action is obtained through the through holes 9a formed in the peripheral wall portion of the conduit 9 as the gas inlet, the high speed exhaust gas flow does not directly hit the sound absorbing material 6, and the sound absorbing material. The deterioration of the silencing performance due to scattering of 6 is also prevented.
[0016]
Although the embodiment in which the present invention is applied to the silencer 1 interposed in the exhaust system of the fuel cell vehicle has been described above, the same applies to a silencer interposed in the exhaust system of a normal vehicle that uses an internal combustion engine as a power source. The present invention can be applied to.
[0017]
【The invention's effect】
As is apparent from the above description, according to the present invention, it is possible to prevent the sound absorbing material from absorbing water, to prevent the sound absorbing performance from being lowered due to water absorption, and to obtain a silencer suitable for a fuel cell vehicle.
[Brief description of the drawings]
1 is a perspective view of an example of the silencer of the present invention. FIG. 2 is a cutaway side view of the silencer of FIG. 1. FIG. 3 is a plan view of a part of the silencer of FIG. IV-IV cross-sectional view of line [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Silencer 4 Silencer body 5 Partition plate 5a Communication hole 6 Sound absorbing material 7 Sound absorbing chamber 8 Expansion chamber 9 Conduit 9a Through hole

Claims (2)

Gas internal space of the silencer body, I by the specification Setsuban an upper acoustic chamber filled with sound absorbing material, and divided into a lower side of the expansion chamber, a gas inlet into the sound absorption chamber to said expansion chamber The silencer is provided with an outlet, and the partition plate is provided with a communication hole for communicating the upper sound absorbing chamber and the lower expansion chamber . Silencer of claim 1, wherein the gas inlet, through the acoustic chamber constituted by a conduit extending into the expansion chamber, and wherein the forming the plurality of through holes in the peripheral wall of the conduit.

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