JP4369842B2 - Vehicle silencer - Google Patents

Description

  The present invention relates to a muffler for a vehicle.

Conventionally, as a muffler for a vehicle, for example, as shown in a process diagram of FIG. 9, an inlet pipe 103 and an outlet pipe 104 are attached to inner plates 101 and 102 that partition the inside of the muffler for a vehicle, and end plates are provided at both ends. An intermediate assembly A to which 105 and 106 are attached is formed, and a metal plate 107 a is wound around the outer periphery of the intermediate assembly A to form a shell 107 composed of two layers of an outer shell and an inner shell. A structure in which both end opening edges and end plates 105 and 106 are integrated by welding over the entire circumference is known (see Patent Documents 1 and 2).
JP 2003-138935 A JP 2002-206422 A

  However, in the vehicle silencer described in Patent Documents 1 and 2, water accumulated inside the vehicle silencer enters the gap between the inner shell and the outer shell, and this water is heated at the temperature of the exhaust gas. As a result, the pressure between the two shells increases and the two parts deform.

  The present invention has been made to solve the above-mentioned problems, and the object of the present invention is to make the space between the outer shell and the inner shell communicate with the outside while suppressing a large leak of exhaust gas. Therefore, it is providing the silencer for vehicles which can prevent a deformation | transformation of both shells.

  In the first aspect of the present invention, the metal plate is wound in multiple cylinders to form the outer shell and the inner shell, and the opening edge portion of the both shells and the end plate are extended over the entire circumference excluding a predetermined portion. A second welded portion in which the shell and the end plate are welded in the circumferential direction so as to overlap a predetermined portion at a position offset in the axial direction from the first welded portion. A welded portion is formed, and a labyrinth structure is formed by the first welded portion and the second welded portion, whereby the space between both shells is brought into communication with the outside via a predetermined portion. .

  According to a second aspect of the present invention, in the vehicle silencer according to the first aspect, the first welded portion or the second welded portion is formed by laser welding.

  In the muffler for a vehicle according to claim 1, a metal plate is wound in multiple cylinders to form an outer shell and an inner shell, and the opening edges and end plates of both shells except for a predetermined portion are all removed. A first welded portion welded over the circumference is formed, and both the shell and the end plate are welded in the circumferential direction so as to overlap a predetermined portion at a position offset in the axial direction from the first welded portion. Since the second welded portion is formed and the labyrinth structure is formed by the first welded portion and the second welded portion, the space between both shells is brought into communication with the outside through a predetermined portion. Water vapor generated in the space between the two shells can be guided to the outside while suppressing a large gas leak, thereby preventing a rise in pressure in the space and preventing deformation of both shells.

  In the vehicle silencer according to claim 2, since the first welded portion or the second welded portion is formed by laser welding, it is easy to manage the length in the circumferential direction of these welded portions and ensure the welding accuracy. It becomes.

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

Example 1 will be described below.
1 is a side sectional view of a vehicle silencer according to a first embodiment of the present invention, FIG. 2 is a top view thereof, FIG. 3 is a bottom view thereof, and FIG. 4 is a sectional view taken along line S4-S4 of FIG.
5 is an enlarged sectional view taken along line S5-S5 in FIG. 3, FIG. 6 is an enlarged sectional view taken along line S6-S6 in FIG. 3, and FIG. 7 is a diagram for explaining the manufacture of the vehicle silencer of the first embodiment. .

First, the overall configuration will be described.
As shown in FIGS. 1-3, the silencer for vehicles of Example 1 of this invention has the intermediate assembly 1, the shell main body 2, and the end plates 3a and 3b as the main structures.

The intermediate assembly 1 is composed of two inner plates 1a, 1b, an inlet pipe 1c, and an outlet pipe 1d, and the silencer is partitioned into three chambers 1e, 1f, 1g.
Further, the outer shape of the inner plates 1a and 1b is formed in a flat oval shape.
The inlet pipe 1c is assembled so as to pass through a fixing hole 3d of an end plate 3a, which will be described later, and two inner plates 1a, 1b.
The outlet pipe 1d is assembled so as to pass through the two inner plates 1a and 1b and the fixing hole 3d of the end plate 3b.
A plurality of communication holes (not shown) are formed in the inner plates 1a and 1b.

As shown in FIG. 4, the shell body 2 is composed of two layers of an outer shell 2a and an inner shell 2b formed by winding a metal plate in a cylindrical shape, and the cross section thereof is the inner plates 1a, 1b. In the same manner as the outer shape, the shape is flat and elliptical, whereby the small arc portions 5 and the large arc portions 6 are alternately formed.
The circumferential ends of the shells 2a and 2b are overlapped on the upper portion of the shell body 2, and an overlap portion 2c is formed here, and the overlap portion 2c is spot welded in several axial directions. It is fixed by S.

As shown in FIGS. 5 and 6, the opening edge portions of both ends of the shells 2 a and 2 b and the cylindrical portion 3 c of the end plates 3 a and 3 b to be described later are all except for a predetermined portion 2 d disposed at the lower part of the shell body 2. The first welds X are fixed by laser welding over the circumference.
The shells 2a, 2b and the end plates 3a, 3b are welded in the circumferential direction so as to overlap the predetermined part 2d at a position offset by a predetermined distance W1 in the axial direction from the first weld X. Two welds Y are formed respectively.
Therefore, the labyrinth structure is formed by the first welded portion X and the second welded portion Y when the circumferential length W3 of the second welded portion Y is longer than the circumferential length W2 of the predetermined portion 2d. The space between the shells 2a and 2b is in communication with the outside via the predetermined portion 2d.

  The end plates 3a and 3b are for closing the opening portions at both ends of the shells 2a and 2b. A cylindrical portion 3c bent in the axial direction is formed on the outer periphery of the end plates 3a and 3b. Each hole 3d is formed.

Next, manufacture of the vehicle silencer of the present embodiment will be described based on the process explanatory diagram of FIG.
First, as shown in FIG. 7A, the intermediate assembly 1 is assembled by assembling the two inner plates 1a and 1b through the inlet pipe 1c and the outlet pipe 1d.

  Next, as shown in FIG. 7 (b), the metal plates are wound twice around the outer peripheries of the inner plates 1a and 1b, and the overlap portion 2c is spot-welded S at several locations in the axial direction, whereby both shells 2a , 2b are fixed to the inner plates 1a, 1b.

  Next, as shown in FIG. 7 (c), the cylindrical portions 3c of both end plates 3a, 3b are respectively attached to the inner sides of the both end opening edges of the outer shell 2a. By forming the welded portion Y and fixing both, the manufacture of the vehicle silencer is completed.

Next, the operation will be described.
In the vehicle silencer configured as described above, the inlet pipe 1c is connected to the exhaust gas upstream exhaust pipe (not shown), and the outlet pipe 1d is connected to the exhaust gas downstream exhaust pipe (not shown). As a result, the exhaust gas flowing in from the upstream side exhaust pipe is guided to the chamber 1g, and then undergoes expansion / contraction action while flowing in the order of the chamber 1f and the chamber 1e through the communication holes of the inner plates 1a and 1b. The sound is silenced and discharged from the outlet pipe 1d to the downstream exhaust pipe.
At this time, since the shell body 2 has a two-layer structure of the outer shell 2a and the inner shell 2b, radiated sound can be reduced.
When the condensed water of the exhaust gas accumulated in the chambers 1e, 1f, and 1g enters the gap between the outer shell 2a and the inner shell 2b, it is vaporized by being heated at the temperature of the exhaust gas, whereby both shells 2a, 2a, The pressure between 2b tries to rise.

As described with reference to FIG. 4, the cross section of the shell main body 2 such as the vehicle silencer of the first embodiment has alternating small arc portions 5 and large arc portions 6 such as a polygon, an ellipse, or a race track type. In the case where it is formed in a cylindrical cross section other than a perfect circle formed in the above, since the shells 2a and 2b are in close contact with each other in the small arc portions 5 formed on the left and right sides thereof, the gap is closed, There is almost no escape space for water vapor generated between the shells 2a, 2b in the lower large arc portion 6, and as a result, the pressure between the shells 2a, 2b rises, and the two are deformed so as to expand.
In addition, since the large circular arc part 6 has low rigidity compared with the small circular arc part 5, it is especially easy to deform | transform.

  However, in the vehicle silencer of the first embodiment, as shown in FIG. 3, water vapor (shown by the broken arrows) between the shells 2a and 2b in the lower part of the shell body 2 is exposed to the outside through the predetermined portion 2d. Thus, the pressure rise in the space between both shells 2a and 2b can be suppressed, and deformation of both shells 2a and 2b can be prevented.

Further, the water vapor between the shells 2a and 2b in the upper part of the shell body 2 passes through the gap end portion 8 of the inner shell 2b to the outside of the vehicle silencer via the gap end portion 7 of the outer shell 2a in the overlapping portion 2c. Can be led into the vehicle silencer.
Further, since the labyrinth structure is formed between the second welded portion Y and the first welded portion X, there is no possibility that a large amount of exhaust gas is discharged through the predetermined portion 2d during normal times.

  As described above, in the vehicle silencer according to the first embodiment, the outer shell 2a and the inner shell 2b are formed by winding the metal plate in a cylindrical shape, and the opening edges of both shells 2a and 2b are formed. 1st welded part X is formed by welding a part and end plate 3a, 3b over the perimeter except predetermined part 2d, and it is a predetermined part in the position offset from the 1st welded part X in the axial direction. A second weld Y is formed by welding the shells 2a, 2b and the end plates 3a, 3b in the circumferential direction so as to overlap 2d, and the labyrinth is formed by the first weld X and the second weld Y. By forming the structure, the space between the two shells 2a and 2b is in communication with the outside through the predetermined portion 2d, so that the water vapor between the two shells 2a and 2b can be transferred to the outside while suppressing large leakage of exhaust gas. This increases the pressure rise between the shells 2a and 2b. Ete both shells 2a, a deformation of 2b can be prevented.

  In addition, since the first and second welds X and Y are formed by laser welding, it is easy to manage the circumferential lengths of both the welds X and Y and ensure the welding accuracy.

Although the present embodiment has been described above, the present invention is not limited to the above-described embodiment, and design changes and the like within a scope not departing from the gist of the present invention are included in the present invention.
For example, in the present embodiment, the first and second welds X and Y are laser welded, but hybrid welding combining seam welding, laser welding, MIG welding, and TIG welding may be employed.

  Further, as shown in FIG. 8, the first weld X may be formed at the open ends of both shells 2a and 2b.

Further, the number, position, and shape of the predetermined portion 2d can be changed as appropriate. For example, the predetermined portion 2d may be provided only on one side of both open end portions of the shells 2a and 2b.
Further, the outer shell 2a at the predetermined portion 2d is partially cut away to communicate with the outside, or the length W1 in the circumferential direction of the predetermined portion 2d and the length W2 in the circumferential direction of the second welded portion Y are appropriately changed. Therefore, it is natural to adjust the discharge amount of water vapor.
Of course, the vehicle silencer of the present invention can also be implemented when the cross-sectional shape of both shells is a perfect circle.

It is a sectional side view of the silencer for vehicles of Example 1 of the present invention. It is a top view of the silencer for vehicles of the present Example 1. It is a bottom view of the muffler for vehicles of the present Example 1. It is sectional drawing in the S4-S4 line | wire of FIG. It is an expanded sectional view in the S5-S5 line of FIG. It is an expanded sectional view in the S6-S6 line of FIG. It is a figure explaining manufacture of the silencer for vehicles of the present Example 1. It is a figure explaining the silencer for vehicles of other examples. It is a figure explaining manufacture of the conventional silencer for vehicles.

Explanation of symbols

S spot welding X first welded portion Y second welded portion 1 intermediate assembly 1a, 1b inner plate 1c inlet pipe 1d outlet pipe 1e, 1f, 1g chamber 2 shell body 2a outer shell 2b inner shell 2c overlapped portion 2d predetermined portion 3a, 3b End plate 3c Cylinder part 3d Fixing hole 5 Small arc part 6 Large arc part 7, 8 Clearance edge part

Claims (2)

A metal plate is wound in multiple cylinders to form an outer shell and an inner shell,
Forming a first welded portion in which the opening edges of the shells and the end plate are welded over the entire circumference except for a predetermined portion;
Forming a second welded portion in which both the shell and the end plate are welded in the circumferential direction so as to overlap a predetermined portion at a position offset in the axial direction with the first welded portion;
A muffler for a vehicle, wherein a labyrinth structure is formed by the first welded portion and the second welded portion so that the space between both shells is in communication with the outside through a predetermined portion. The muffler for a vehicle according to claim 1,
A muffler for a vehicle, wherein the first welded portion or the second welded portion is formed by laser welding.

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