JP2009197627A - Sound absorber for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sound absorber for a vehicle that can significantly reduce low-frequency components contained in exhaust noise without causing the complication of internal structure or deterioration in the flexibility of design. <P>SOLUTION: The sound absorber for the vehicle 1 is provided with a sound absorber body 5 equipped with a tubular shell 2 sandwiched by two end plates 3, 4 that close both ends of the shell 2 and incorporating sound absorbing chambers R1-R3, an inlet pipe 6 that makes exhaust gases flow into sound absorbing chambers R1-R3, and an outlet pipe 7 that makes the exhaust gases exhausted from the sound absorbing chambers R1-R3. A part of the outlet pipe 7 is placed along the outer periphery of the end plate 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a muffler for a vehicle.

Conventionally, in a vehicle silencer, it is generally effective to form a long exhaust passage of an outlet pipe as a means for silencing low frequency components in exhaust noise (see Patent Document 1).
JP 2002-21528 A

  However, in the conventional invention, since the outlet pipe is bent and extended in a substantially U shape in the vehicle silencer, the internal structure of the vehicle silencer is complicated and the degree of design freedom is reduced. There was a problem.

  The present invention has been made to solve the above-described problems, and the object of the present invention is to reduce the exhaust noise level without complicating the internal structure of the vehicle silencer and reducing the degree of design freedom. The present invention is to provide a vehicle silencer capable of greatly reducing frequency components.

  According to the first aspect of the present invention, a cylindrical shell, a silencer body having a silencing chamber surrounded by two end plates that close both ends of the shell, and an inlet for allowing exhaust to flow into the silencing chamber A muffler for a vehicle having a pipe and an outlet pipe for discharging exhaust gas from the muffler chamber, wherein a part of the outlet pipe is disposed along an outer surface of the end plate.

According to the first aspect of the present invention, a part of the outlet pipe is disposed along the outer surface of the end plate.
Thereby, the low frequency component in exhaust noise can be significantly reduced without complicating the internal structure of the vehicle silencer and reducing the degree of design freedom.

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

Example 1 will be described below.
FIG. 1 is a plan view showing a vehicle silencer of the first embodiment, FIG. 2 is a diagram for explaining the internal structure of the silencer body of the first embodiment, FIG. 3 is a cross-sectional view taken along line S3-S3 of FIG. Is a sectional view taken along line S4-S4 in FIG. 2, and FIG. 5 is a sectional view taken along line S5-S5 in FIG.

First, the overall configuration will be described.
As shown in FIGS. 1 to 4, the vehicle silencer 1 according to the first embodiment includes a silencer body 5 including a shell 2 and end plates 3 and 4, an inlet pipe 6, an outlet pipe 7, and the like. ing.

The shell 2 is formed in a cylindrical shape by winding a thin plate-like base material in multiple layers, and its end in the winding direction is fixed by a plurality of spot welds X1 (see FIG. 1) along the axial direction. Yes.
Further, the vehicle front side opening end of the shell 2 is closed by a plate-like end plate 3, and both of them are fixed by welding X 2 over the entire circumference. Both of these may be fixed by caulking using lock seam processing.
On the other hand, the vehicle rear side opening end of the shell 2 is fixed by welding X3 over the entire circumference in a state where the opening end of the substantially bowl-shaped end plate 4 is overlapped on the inner side. Both of these may be fixed by caulking using lock seam processing.

The interior of the silencer body 5 is divided into three silencer chambers R1 to R3 by two plate-like baffle plates 8 and 9, and adjacent silencer chambers R1 to R3 are connected to the baffle plates 8 and 9, respectively. The plurality of communication holes 10 are in communication with each other.
The baffle plates 8 and 9 and the shell 2 are fixed by spot welding X4 at a plurality of locations on the circumference of the shell 2.

The inlet pipe 6 passes through the end plate 3, the baffle plate 8, and the baffle plate 9 and is disposed in a state where one end portion thereof communicates with the sound deadening chamber R 3.
An annular projecting burring portion 3a is formed at a portion of the end plate 3 where the inlet pipe 6 penetrates, and both are fixed by welding X5 over the entire circumference.
As shown in FIG. 3, a plurality of small holes 11 are formed in the middle of the inlet pipe 6, and a sound absorbing member 12 made of stainless mesh is formed on the outer surface of the inlet pipe 6 in which the small holes 11 are formed. It is provided in a state surrounded by a cylindrical outer cylinder 13.

The outlet pipe 7 includes a downstream portion 14, an extension portion 15, and an upstream portion 16.
The downstream portion 14 of the outlet pipe 7 passes through the end plate 4 and the baffle plates 8 and 9, and one end portion 14 a thereof is connected to the one end portion 15 a of the extension portion 15.
An annular protrusion-shaped burring portion 4a is formed at a portion of the end plate 4 that penetrates the downstream portion 14, and both are fixed by welding X6 over the entire circumference.
As shown in FIG. 4, a plurality of small holes 17 are formed in the middle of the downstream portion 14, and a sound absorbing member 18 made of stainless mesh is formed on the outer surface portion of the downstream portion 14 where the small holes 17 are formed. It is provided in a state surrounded by a cylindrical outer cylinder 19.

As shown in FIG. 5, the extension 15 of the outlet pipe 7 is bent within the face of the silencer body 5 with one pipe being in close contact with the outer surface of the end plate 3. It is formed in the shape.
Specifically, one end portion 15a and the other end portion 15b of the extension portion 15 described above are spaced apart from each other in the width direction of the end plate 3, and the inlet pipe 6 is disposed therebetween.
The extension portion 15 is bent from the one end portion 15a in consideration of the exhaust resistance and is bent with a practically manufacturable curvature along the outer periphery of the end plate 3 (illustrated by a two-dot chain line in the figure). And is connected to the other end portion 15 b via the inlet pipe 6 and the downstream portion 14.
One end portion 15a of the extension portion 15 penetrates the annular protruding burring portion 3b formed in the end plate 3, and these three members are arranged around the entire circumference with the one end portion 14a of the downstream portion 14 inserted therein. It is fixed by welding X7.
Moreover, the opening end of the one end part 14a of the downstream part 14 is formed in an inclined shape toward the bending direction of the extension part 15, and smooth connection of exhaust gas between the downstream part 14 and the extension part 15 is achieved.

On the other hand, the other end portion 15b of the extension portion 15 passes through the annular projecting burring portion 3c of the end plate 3, and these three members are inserted with the end portion 16a of the straight tubular upstream portion 16 inserted therein. It is fixed by welding X8 over the entire circumference.
In addition, the opening end of the one end portion 16a of the upstream portion 16 is formed in an inclined shape toward the bending direction of the extension portion 15, and smooth connection of exhaust between the upstream portion 16 and the extension portion 15 is achieved.
Further, the extension 15 is fixed to the outer surface of the end plate 3 at an appropriate location by welding X9.
The other end portion of the upstream portion 16 passes through both the baffle plates 8 and 9 and communicates with the sound deadening chamber R3.

  In addition, each component of the vehicle silencer 1 is made of metal. However, the sound absorbing member 12 may be made of glass wool.

Next, the operation will be described.
<Exhaust noise suppression>
In the muffler 1 for a vehicle thus configured, the other end of the inlet pipe 6 is connected to an exhaust pipe on the engine side (not shown) while the other end of the downstream part 14 of the outlet pipe 7 is not shown. Connected to the tail pipe.

As shown in FIG. 2, the exhaust gas (shown by broken line arrows in the figure) flowing in from the connection pipe on the engine side first flows through the inlet pipe 6 downstream and then flows into the muffler chamber R <b> 3.
At this time, the noise energy of the exhaust gas passing through the inlet pipe 6 enters the outer cylinder 13 through the plurality of small holes 11 and is silenced by the buffering action of the sound absorbing member 12.

Next, the noise energy of the exhaust gas flowing into the muffling chamber R3 is muffled by receiving the expansion and contraction action by entering the muffling chamber R2 and the muffling chamber R1 through the communication holes 10 of the baffle plates 8 and 9. .
Further, the exhaust gas flowing into the silencer chamber R3 flows through the upstream portion 16, the extension portion 15, and the downstream portion 14 of the outlet pipe 7 in this order, and then is discharged to the outside from the tail pipe.
At this time, as shown in FIG. 5, a long passage length (exhaust pipe 7 length) of the exhaust (illustrated by a broken arrow in the figure) can be secured by the extension portion 15 of the outlet pipe 7 in particular. The low frequency component in the inside can be greatly reduced.
Further, the noise energy of the exhaust gas passing through the downstream portion 14 enters the outer cylinder 19 through the plurality of small holes 17 and is silenced by the buffering action of the sound absorbing member 18.

<Reducing end plate radiation>
In the first embodiment, as described above, a part of the extension portion 15 is fixed to the end plate 3 by welding at an appropriate location with welding.
Therefore, the rigidity of the end plate 3 can be improved, and the radiation noise due to the exhaust pulsation can be reduced.

<Design flexibility inside silencer body>
In the first embodiment, a part of the outlet pipe 7, that is, the extension 15 is arranged outside the silencer body 5.
Therefore, the degree of freedom in design can be expanded without complicating the internal structure of the silencer body 5.

<About miniaturization of extension and extension of flow path>
In the first embodiment, as described above, the one end portion 15a and the other end portion 15b of the extension portion 15 are spaced apart from each other in the width direction of the end plate 3, and the inlet pipe 6 is disposed between them. Yes.
Then, after turning around the inner edge of the outer peripheral edge of the end plate 3 while bending at a curvature that can be practically manufactured from the one end 15a of the extension 15, the inlet pipe 6 and the downstream It is connected to the other end part 15b via the part 14.
Accordingly, the outer shape of the extension 15 can be accommodated within the outer peripheral edge of the end plate 3 to achieve downsizing, and at the same time, the exhaust flow path length can be maximized by bending only in the vertical plane of the end plate 3. it can.

<About vehicle layout in the longitudinal direction of the extension and appearance design>
In the first embodiment, the extension 15 is disposed along the end plate 3 on the vehicle front side.
Accordingly, the extension portion 15 is cooled by receiving the vehicle traveling wind from the front of the vehicle, and can obtain a silencing effect due to the volume reduction action of the exhaust flowing inside.
Moreover, since the extension part 15 is not visible from the vehicle rear side, the appearance design is not impaired.

Finally, the effects are listed.
As described above, in the invention of the first embodiment, the silencing chambers R1 to R3 are provided in the inside surrounded by the cylindrical shell 2 and the two end plates 3 and 4 closing both ends of the shell 2. In the vehicle silencer 1 having the silencer body 5, the inlet pipe 6 for introducing exhaust gas into the silencer chambers R 1 to R 3, and the outlet pipe 7 for discharging exhaust gas from the silencer chambers R 1 to R 3, a part of the outlet pipe 7 is used. Since the end plate 3 is disposed along the outer surface, the low frequency components in the exhaust noise can be significantly reduced without complicating the internal structure of the vehicle silencer 1 and reducing the degree of design freedom.

  In addition, since a part of the outlet pipe 7 is disposed in the outer peripheral edge portion of the end plate 3, the vehicle silencer 1 can be made compact.

  Further, since a part of the outlet pipe 7 is fixed in close contact with the outer surface of the end plate 3, the rigidity of the end plate 3 can be improved and the radiated sound can be reduced.

  In addition, since a part of the outlet pipe 7 is disposed along the outer surface of the end plate 3 on the front side of the vehicle, it can be cooled by the vehicle running wind, and exhaust noise can be reduced by reducing the volume of the exhaust. In addition, the appearance design can be improved.

Although the embodiments have been described above, the present invention is not limited to the above-described embodiments, and design changes and the like within the scope not departing from the gist of the present invention are included in the present invention.
The internal structure of the silencer body 5 can be set as appropriate.
Similarly, the detailed shape of the extension, for example, the channel cross-sectional shape, the channel length, the bending angle, the number of bendings, and the like can be set as appropriate.

  Furthermore, an extension can also be provided on the end plate 4 side, one end of which can be connected to the other end of the downstream portion 14, and the other end can be bent outward and connected to the tail pipe. In this case, the outlet pipe 7 can be further extended.

It is a top view which shows the silencer for vehicles of Example 1. It is a figure explaining the internal structure of the silencer main body of Example 1. FIG. It is sectional drawing in the S3-S3 line | wire of FIG. It is sectional drawing in the S4-S4 line | wire of FIG. It is sectional drawing in the S5-S5 line | wire of FIG.

Explanation of symbols

X1, X2, X3, X4, X5, X6, X7 Welding 1 Vehicle silencer 2 Shell 3, 4 End plate 3a, 3b, 3c, 4a Burring part 5 Silencer body 6 Inlet pipe 7 Outlet pipe 8, 9 Baffle plate 10 communication hole 11 small hole 12 sound absorbing member 13 outer cylinder 14 downstream part 14a (downstream part) one end part 15 extension part 15a (extension part) one end part 15b (extension part) other end part 16 upstream part 16a (upstream part) 1) one end 17 small hole 18 sound absorbing member 19 outer cylinder

Claims (4)

A silencer body having a silencer chamber in an interior surrounded by a cylindrical shell and two end plates closing both ends of the shell;
An inlet pipe that allows exhaust to flow into the muffler chamber;
In a vehicle silencer having an outlet pipe for discharging exhaust from the silencer chamber,
A muffler for a vehicle, wherein a part of the outlet pipe is disposed along an outer surface of the end plate. The muffler for a vehicle according to claim 1,
A muffler for a vehicle, wherein a part of the outlet pipe is disposed in an outer peripheral edge portion of an end plate. The muffler for a vehicle according to claim 1 or 2,
A muffler for a vehicle, wherein a part of the outlet pipe is fixed in close contact with an outer surface of an end plate. The muffler for vehicles according to any one of claims 1 to 3,
A muffler for a vehicle, wherein a part of the outlet pipe is disposed along an outer surface of an end plate on a vehicle front side.

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