JP2004293538A - Deformation preventing structure for shell of muffler body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deformation preventing structure for a shell of a muffler body of such a configuration that the shell body part in cylindrical shape constituting the muffler body is formed from two layers, an inner shell and an outer shell, capable of preventing the shell from deformation caused by vaporization of the water having intruded to between the inner shell and the outer shell. <P>SOLUTION: The deformation preventing structure applies to the shell of the muffler body of such a configuration that the shell body part 1 in cylindrical shape is formed from two layers, the inner shell 11 and the outer shell 12, in which the space extending in the axial direction of the shell body part 1 between the inner shell 11 and the outer shell 12 constituting the shell body part 1 is formed from gaps 13 in the axial direction between the sides of a lock seam part 11a formed in an outward facing ridge shape in a coupling part when the inner shell 11 is formed cylindrically through sheet metal working and the outer shell 12, and openings 14 having communication with the gaps 13 are formed at the end in the axial direction of the outer shell 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a structure for preventing a shell deformation of a muffler main body in which a cylindrical shell main body is composed of two layers, an inner shell and an outer shell.

  Conventionally, a muffler main body of a vehicle is formed in a hollow shape in which both open ends of a shell main body formed in a hollow elliptical cylindrical shape are closed by front and rear outer plates, respectively, and a plurality of inner panels are formed in the hollow portion. (See, for example, Patent Document 1).

JP-A-2002-97922 (specification (3) page, FIG. 2)

  In the conventional muffler described above, water contained in the exhaust gas is condensed by coming into contact with the low-temperature exhaust pipe and the muffler main body at the time of a low temperature start or the like, so that water accumulates in the hollow portion of the muffler main body. This water is vaporized when the muffler body is heated by the exhaust gas, and is discharged to the outside together with the exhaust gas.

  However, as shown in the longitudinal side view of FIG. 10, in a muffler in which a cylindrical shell main body 101 constituting a muffler main body is constituted by two layers of an inner shell 102 and an outer shell 103, FIG. As shown in the drawing, water 104 accumulated in the hollow portion of the muffler body enters the gap between the inner shell 102 and the outer shell 103 as shown in FIG. When heated at the temperature of the exhaust gas, the gas is vaporized, and the pressure in the gap between the inner shell 102 and the outer shell 103 rises. As a result, as shown in FIG. There was a problem of deforming.

  The problem to be solved by the present invention is to evaporate water that has entered between an inner shell and an outer shell in a muffler in which a cylindrical shell body that constitutes a muffler body has two layers, an inner shell and an outer shell. An object of the present invention is to provide a shell deformation preventing structure of a muffler main body, which can prevent deformation of a shell due to the above.

  In order to solve the above-mentioned problem, the muffler main body shell deformation preventing structure according to claim 1 forms the shell main body part in a muffler main body in which a cylindrical shell main body is formed of two layers of an inner shell and an outer shell. A space portion extending in the axial direction of the shell main body portion is formed between the inner shell and the outer shell, and an opening communicating with the space portion is formed at a predetermined position of the outer shell. And

  According to a second aspect of the present invention, there is provided the muffler main body shell deformation preventing structure according to the first aspect, wherein the space portion faces outward to the connecting portion when the inner shell is formed into a sheet metal sheet. The means is characterized in that it is constituted by a gap formed in the axial direction between both sides of the lock seam portion formed on the ridge and the outer shell.

  4. The muffler main body shell deformation preventing structure according to claim 3, wherein the inner shell and the outer shell constituting the shell main body part in a muffler main body in which a cylindrical shell main body is formed of two layers of an inner shell and an outer shell. A space extending in the axial direction of the shell main body is formed between the inner shell and the inner shell, and an opening communicating with the space is formed at a predetermined position of the inner shell.

According to a fourth aspect of the present invention, there is provided the muffler main body shell deformation preventing structure according to the third aspect, wherein the space portion is directed outward to the connecting portion when the inner shell is formed into a sheet metal shape. It consists of a gap formed in the axial direction between both sides of the lock seam portion formed on the ridge and the outer shell,
The opening is formed by cutting out a part of a plate material constituting the lock seam portion.

  A muffler body shell deformation preventing structure according to claim 5, wherein in the muffler body shell deformation preventing structure according to any one of claims 1 to 4, both ends in the axial direction of the outer shell or the inner shell are provided. It is a means characterized by being formed in.

According to the first aspect of the present invention, when the water that has entered the gap between the inner shell and the outer shell is vaporized by being heated at the temperature of the exhaust gas, the steam is converted into the inner shell. Through the space formed in the state extending in the axial direction between the inner shell and the outer shell, and is immediately discharged to the outside from the opening formed at a predetermined position of the outer shell. The pressure in the gap between them does not rise.
Therefore, an effect is obtained that the deformation of the shell due to the vaporization of the water that has entered between the inner shell and the outer shell can be prevented.

  In the shell deformation preventing structure of the muffler body according to claim 2, as described above, the both sides of the lock seam portion are formed such that the space portion is formed as an outwardly projecting ridge in the connecting portion when the inner shell is formed into a sheet metal. Since it is constituted by a gap formed in the axial direction between the portion and the outer shell, it is possible to save the trouble of forming a space portion in a state of extending in the axial direction between the inner shell and the outer shell. Thus, the manufacturing cost can be reduced.

In the muffler body shell deformation preventing structure according to the third aspect, when the water that has entered the gap between the inner shell and the outer shell is vaporized by being heated at the temperature of the exhaust gas, the steam is formed between the inner shell and the outer shell. Through a space formed in a state extending in the axial direction between the inner shell and the outer shell, whereby the inner shell and the outer shell are immediately discharged from the opening formed at a predetermined position of the inner shell. Between the inner shell and the inner shell does not rise more than the internal pressure.
Therefore, an effect is obtained that the deformation of the shell due to the vaporization of the water that has entered between the inner shell and the outer shell can be prevented.

  In the shell deformation prevention structure of the muffler body according to claim 4, both sides of the lock seam portion formed with outwardly projecting ridges in the connecting portion when the inner shell is formed into a sheet metal shape in a cylindrical shape, as described above. Since it is constituted by a gap formed in the axial direction between the portion and the outer shell, it is possible to save the trouble of forming a space portion in a state of extending in the axial direction between the inner shell and the outer shell. Thus, the manufacturing cost can be reduced.

  Further, the opening is formed by cutting out a part of a plate material constituting the lock seam portion, so that the opening is formed by a gap formed in the axial direction between both sides of the lock seam portion and the outer shell. The communication between the space and the inner shell can be reliably established.

  In the shell deformation preventing structure of the muffler body according to the fifth aspect, as described above, since the opening is formed at both axial ends of the outer shell, steam generated in the gap between the inner shell and the outer shell can be removed. , Can be efficiently discharged from both openings.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The shell deformation preventing structure of the muffler body according to the first embodiment corresponds to the first, second, and fifth aspects of the present invention.
First, a structure for preventing a shell deformation of a muffler body according to the first embodiment will be described with reference to the drawings.

  FIG. 1 is a plan view showing a muffler to which a shell deformation preventing structure of a muffler body according to a first embodiment is applied, FIG. 2 is a longitudinal sectional view taken along the line II-II of FIG. 1, and FIG. FIG. 4 is an enlarged sectional view of a portion B of FIG. 2, FIG. 5 is a longitudinal sectional view taken along line VV of FIG. 1, and FIG. 6 shows a muffler to which a shell deformation preventing structure of the muffler body of the first embodiment is applied. In these drawings, M is a muffler, 1 is a shell body, 2, 3 is an outer plate, 4 is an inner panel, 5, 6 are inlet pipes, 7 is an inner pipe, and 8 is an outlet pipe. .

More specifically, the shell body 1 is composed of two layers, an inner shell 11 and an outer shell 12.
The inner shell 11 is formed by winding a single stainless steel plate into a substantially elliptical shape and overlapping and bending both end edges to form a lock seam portion 11a protruding outward at a right end edge, thereby forming an inner surface. On the side, it is formed in a cylindrical shape having a substantially elliptical cross section without a protrusion (see FIGS. 3 and 5).

  The outer shell 12 is a lock seam portion projecting outward at the right edge by winding a single stainless steel plate in a substantially elliptical shape along the outer peripheral surface of the inner shell 11 and folding and bending both edges. 12a is formed, whereby the inner surface is formed in a cylindrical shape having a substantially elliptical cross section without a protruding portion (see FIG. 4).

  As described above, the shell main body 1 is formed in two layers of the inner shell 11 and the outer shell 12 by sheet metal forming, so that both side portions of the lock seam portion 11a in the inner shell 11 as shown in FIGS. Clearances (spaces) 13, 13 extending over the entire length in the axial direction are formed between the outer shell 12 and the outer shell 12.

  As shown in FIGS. 1 and 5, openings 14 communicating with gaps (spaces) 13 extending over the entire length in the axial direction between the outer shell 12 and the outer shell 12 are provided at both ends in the axial direction of the outer shell 12. , 14 are formed.

  The inlet pipes 5, 6, the inner pipe 7, and the outlet pipe 8 are provided with a large number of communication holes 5a, 6a, 7a, 8a on the outer periphery thereof as shown by the circles in FIG. It is in communication with the room.

Next, the operation and effect of the first embodiment will be described.
In the first embodiment, since the configuration is as described above, the moisture contained in the exhaust gas is condensed by coming into contact with the low-temperature exhaust pipe and each part in the muffler main body at the time of a low-temperature start or the like, and is condensed. When water enters the gap between the inner shell 11 and the outer shell 12 and the muffler body is heated by the exhaust gas, the water that has entered the gap is vaporized. The openings 14, 14 formed at both axial ends of the outer shell 12 pass through two gaps (spaces) 13, 13 formed in a state extending in the axial direction between the inner shell 11 and the outer shell 12. Is discharged immediately and efficiently to the outside, so that the pressure in the gap between the inner shell 11 and the outer shell 12 does not increase.

  FIG. 7 shows experimental data showing the pressure reducing effect in the first embodiment. As is clear from the experimental data, FIG. 7 shows a case where the opening indicated by a black angle is not provided, and an arbitrary point indicated by a black circle. When a hole was made, the pressure in the gap increased as the number of repetitions of the experiment increased, whereas in the case of Example 1 indicated by *, the pressure in the gap increased only slightly.

  Therefore, an effect is obtained that the deformation of the shell main body 1 due to the vaporization of the water that has entered between the inner shell 11 and the outer shell 12 can be prevented.

  Further, as a space communicating with the openings 14, 14, the outer shell 12 and both sides of the lock seam portion 11 a formed as an outwardly protruding ridge at the connecting portion when the inner shell 11 is formed into a sheet metal in a cylindrical shape. Since the gaps 13 are formed in the axial direction between the inner shell 11 and the outer shell 12, it is possible to save time and effort for forming a space between the inner shell 11 and the outer shell 12. Thus, the effect that the manufacturing cost can be reduced can be obtained.

  Next, another embodiment of the present invention will be described. In the description of the other embodiments, illustration and description of the same components as those in the first embodiment will be omitted, or the same reference numerals will be given, and the description thereof will be omitted, and only the differences will be described. I do.

The shell deformation preventing structure of the muffler body according to the second embodiment corresponds to the third to fifth aspects of the present invention.
The shell deformation preventing structure of the muffler main body according to the second embodiment extends in the axial direction of the shell main body 1 as shown in FIGS. 8 (plan view) and 9 (enlarged sectional view taken along line IX-IX in FIG. 8). A gap 13 extending over the entire length in the axial direction between the outer shell 12 and both sides of the lock seam portion 11a formed with outwardly projecting ridges at the connecting portion when the inner shell 11 is formed into a cylindrical sheet metal form. , 13 are the same as those in the first embodiment, but in the second embodiment, the openings 15 are formed on the inner shell 11 side, so that the gaps 13, 13 and the inner side of the inner shell 11 are formed. Is different from that of the first embodiment.

  That is, in the second embodiment, the gap 13 and the inside of the inner shell 11 are communicated with each other by cutting out a part of a plate material forming the lock seam portion 11 a at both axial end portions of the inner shell 11. An opening 15 is formed.

Next, the operation and effect of the second embodiment will be described.
In the second embodiment, since the structure is as described above, the moisture contained in the exhaust gas is condensed by coming into contact with the low-temperature exhaust pipe and each part in the muffler body at the time of a low-temperature start or the like, and the water is condensed. When water enters the gap between the inner shell 11 and the outer shell 12 and the muffler body is heated by the exhaust gas, the water that has entered the gap is vaporized. A lock seam portion 11a is formed at both axial ends of the inner shell 11 through two gaps (spaces) 13, 13 formed in a state extending in the axial direction between the inner shell 11 and the outer shell 12. By notching a part of the plate material, the openings 15, 15 formed in a state where the gap 13 and the inside of the inner shell 11 communicate with each other are immediately cut into the inside of the inner shell 11. One efficient but well discharged, thereby, thereby preventing the pressure in the gap between the inner shell 11 and outer shell 12 rises above the internal pressure of the inner shell 11.
Therefore, an effect is obtained that the deformation of the shell due to the vaporization of the water that has entered between the inner shell 11 and the outer shell 12 can be prevented.

Although the present embodiment has been described above, the present invention is not limited to the above-described embodiment, and includes any design change or the like within a range not departing from the gist of the present invention.
For example, in the embodiment, the openings 14, 14 or the openings 15, 15 are formed at both ends in the axial direction of the outer shell 12. However, only one or three or more openings may be provided at arbitrary positions.

  In the embodiment, the gaps 13 formed in the axial direction between the both sides of the lock seam portion 11a and the outer shell 12 form the space communicating with the openings 14 and 14. For example, by interposing a gap forming body such as a wire or a square bar between the inner shell 11 and the outer shell 12 along the axial direction, or by depressing the inner surface of the outer shell 12 along the axial direction, A space may be formed.

  In the second embodiment, the opening 15 for communicating between the gap 13 and the inside of the inner shell 11 is formed by cutting out a part of the plate material forming the lock seam portion 11a. The opening may be constituted by a hole formed in the opening.

It is a top view which shows the muffler to which the shell deformation prevention structure of the muffler main body of Example 1 was applied. FIG. 2 is a longitudinal sectional view taken along line II-II of FIG. 1. FIG. 3 is an enlarged sectional view of a part A in FIG. 2. FIG. 3 is an enlarged sectional view of a portion B in FIG. 2. FIG. 5 is a vertical sectional view taken along line VV in FIG. 1. FIG. 2 is a schematic diagram illustrating a muffler to which the shell deformation preventing structure of the muffler body according to the first embodiment is applied. 4 is experimental data showing a pressure reducing effect in a muffler to which the shell deformation preventing structure of the muffler body according to the first embodiment is applied. It is a top view which shows the muffler to which the shell deformation prevention structure of the muffler main body of Example 2 was applied. FIG. 9 is a longitudinal sectional view taken along line IX-IX in FIG. 8. It is a longitudinal section showing a conventional muffler main part.

Explanation of reference numerals

M Muffler 1 Shell body 2 Outer plate 3 Inner plate 4 Inner panel 5 Inlet pipe 5a Communication hole 6 Inlet pipe 6a Communication hole 7 Inner pipe 7a Communication hole 8 Outlet pipe 8a Communication hole 11 Inner shell 11a Lock seam part 12 Outer shell 12a Lock Seam 13 Gap (space)
14 opening 15 opening

Claims (5)

In a muffler main body in which a cylindrical shell main body is constituted by two layers of an inner shell and an outer shell,
A space extending in the axial direction of the shell main body is formed between the inner shell and the outer shell constituting the shell main body,
An opening for communicating with the space portion is formed at a predetermined position of the outer shell, and the muffler body has a shell deformation preventing structure.   The shell deformation preventing structure of the muffler body according to claim 1, wherein the space portion is formed on a connecting portion with an outwardly protruding ridge at both sides of a lock seam portion when the inner shell is formed into a sheet metal shape. A muffler body shell deformation preventing structure, comprising a gap formed in the axial direction between the outer shell and the outer shell. In a muffler main body in which a cylindrical shell main body is constituted by two layers of an inner shell and an outer shell,
A space extending in the axial direction of the shell main body is formed between the inner shell and the outer shell constituting the shell main body,
An opening for communicating with the space portion is formed at a predetermined position of the inner shell, and the muffler body has a shell deformation preventing structure. The shell deformation preventing structure of the muffler body according to claim 3, wherein the space portion is formed with outwardly projecting ridges at both sides of a lock seam portion formed at a connecting portion when the inner shell is formed into a sheet metal shape. 5. It consists of a gap formed in the axial direction between the outer shell,
A shell deformation preventing structure for a muffler main body, wherein the opening is formed by cutting out a part of a plate material constituting the lock seam portion.   5. The muffler body shell according to claim 1, wherein the opening is formed at both axial ends of the outer shell or the inner shell. 6. Deformation prevention structure.

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