JP4255350B2 - Muffler body shell deformation prevention structure - Google Patents

Description

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

  2. Description of the Related Art Conventionally, a muffler body of a vehicle is formed in a hollow shape in which both open end portions of a shell body portion formed in a hollow elliptical cylindrical shape are closed by front and rear outer plates, and the inside of the hollow portion is a plurality of inner panels. Is partitioned in the axial direction (for example, Patent Document 1).

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

  In the conventional muffler as described above, the moisture contained in the exhaust gas at the time of cold start etc. condenses by contacting the low temperature exhaust pipe or the muffler body, so that water accumulates in the hollow part of the muffler body, When the muffler body is heated by the exhaust gas, the water is vaporized and discharged to the outside together with the exhaust gas.

  However, as shown in the vertical side view of FIG. 10, in the muffler in which the cylindrical shell body 101 constituting the muffler body is composed of two layers of the inner shell 102 and the outer shell 103, As shown in the figure, the water 104 accumulated in the hollow portion of the muffler main body enters the gap between the inner shell 102 and the outer shell 103 as shown in the figure (b), and this water is shown in the figure (c). When the exhaust gas is heated to the temperature of the exhaust gas, it 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 vaporize the water that has entered between the inner shell and the outer shell in the muffler in which the cylindrical shell main body constituting the muffler body is composed of two layers of the inner shell and the outer shell. An object of the present invention is to provide a shell deformation preventing structure for a muffler body that can prevent deformation of the shell due to the above.

In order to solve the above-mentioned problem, the shell deformation preventing structure for a muffler body according to claim 1 comprises the shell body portion in a muffler body in which a cylindrical shell body portion is composed 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 outer shell, an opening communicating with the space is formed at a predetermined position of the inner shell or the outer shell , and the space is The inner shell is formed by a gap formed in the axial direction between the outer shell and the both sides of the lock seam formed on the connecting portion when the inner shell is formed into a sheet metal shape in the cylindrical shape, Cut out a part of the plate member constituting the lock seam part of the inner shell or a part of the plate member constituting the outer shell overlapping the lock seam part. And a means which is characterized in that it is formed by Rukoto.

The shell deformation prevention structure for a muffler body according to claim 2 is the shell deformation prevention structure for a muffler body according to claim 1, wherein the openings are formed at both axial ends of the inner shell or the outer shell. A feature means.

In the invention according to claim 1, since it is configured as described above, 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 becomes the inner shell. Between the inner shell and the outer shell, and is immediately discharged to the outside through an opening formed in a predetermined portion of the inner shell or the outer shell through a space formed in an axially extending state. The pressure in the gap with the outer shell will not increase.
Therefore, the effect that the deformation | transformation of the shell by the vaporization of the water which penetrate | invaded between the inner shell and the outer shell can be prevented is acquired.
The opening is formed by notching a part of a plate material constituting the lock seam part of the inner shell or a part of a part overlapping the lock seam part of the plate material constituting the outer shell, so that the lock seam is formed. It is possible to reliably establish a communication state between the space portion formed by the gap formed in the axial direction between the both side portions of the portion and the outer shell and the inside of the inner shell.

  3. The structure for preventing shell deformation of a muffler body according to claim 2, as described above, both sides of the lock seam portion formed on the connecting portion with outward protrusions when the space portion forms the inner shell into a sheet metal shape. Since it is composed of a gap formed in the axial direction between the inner shell and the outer shell, it is possible to save the trouble of forming the space portion in a state extending in the axial direction between the inner shell and the outer shell. Thus, the manufacturing cost can be reduced.

In the shell deformation prevention structure of the muffler main body according to claim 2, the steam generated in the gap between the inner shell and the outer shell is formed by forming the openings at both ends in the axial direction of the outer shell as described above. Thus, it can be efficiently discharged from both openings.

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

First , the structure for preventing shell deformation of the muffler body of the first embodiment will be described with reference to the drawings.

  1 is a plan view showing a muffler to which a shell deformation preventing structure for a muffler body according to the first embodiment is applied, FIG. 2 is a longitudinal sectional view taken along line II-II in FIG. 1, and FIG. FIG. 4, FIG. 4 is an enlarged cross-sectional view of part B of FIG. 2, FIG. 5 is a vertical cross-sectional view taken along line VV of FIG. 1, and FIG. 6 shows a muffler to which a shell deformation preventing structure of 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 is an inlet pipe, 7 is an inner pipe, and 8 is an outlet pipe. .

More specifically, the shell main body 1 is composed of two layers of an inner shell 11 and an outer shell 12.
The inner shell 11 has a lock seam portion 11a that protrudes outward at the right end edge portion by winding a single stainless steel plate in a substantially oval shape and bending the two end edge portions, thereby forming an inner surface. On the side, it is formed in a cylindrical shape having a substantially elliptical cross section with no protrusions (see FIGS. 3 and 5).

  The outer shell 12 is a lock seam portion that protrudes outward at the right edge portion by winding a single stainless steel plate in a substantially elliptical shape along the outer peripheral surface of the inner shell 11 and bending the two edge portions. 12a is formed, so that the inner surface is formed in a cylindrical shape having a substantially elliptical cross section without a protrusion (see FIG. 4).

  As described above, the shell body portion 1 is formed into two layers of the inner shell 11 and the outer shell 12 by sheet metal forming, whereby both side portions of the lock seam portion 11a in the inner shell 11 are formed as shown in FIGS. And the outer shell 12 are formed with gaps (space portions) 13 and 13 extending over the entire length in the axial direction.

  As shown in FIGS. 1 and 5, openings 14 communicating with gaps (space portions) 13 and 13 extending over the entire length in the axial direction between the outer shell 12 and the outer shell 12 as shown in FIGS. , 14 are formed.

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

Next, operations and effects of the first embodiment will be described.
Since the first embodiment is configured as described above, moisture contained in the exhaust gas at the time of cold start or the like is condensed by contacting each part in the low temperature exhaust pipe or the muffler main body, and the muffler main body is hollow. When water accumulates in the section and this water enters the gap between the inner shell 11 and the outer shell 12, the muffler body is heated with exhaust gas, and the water that has entered the gap vaporizes. Is formed between the inner shell 11 and the outer shell 12 through two gaps (space portions) 13 and 13 formed in the axial direction, and the openings 14 and 14 formed at both axial ends of the outer shell 12. Therefore, the pressure in the gap between the inner shell 11 and the outer shell 12 does not increase.

  FIG. 7 is experimental data showing the pressure reduction effect in the first embodiment. As is clear from this experimental data, the case where the opening indicated by the black corner is not provided and the arbitrary position indicated by the black circle are simply shown. When a hole was made, the pressure in the gap increased as the number of repeated experiments increased, whereas in the case of Example 1 indicated by *, the pressure in the gap increased only slightly.

  Therefore, the effect that the deformation | transformation of the shell main-body part 1 by the vaporization of the water which penetrate | invaded between the inner shell 11 and the outer shell 12 can be prevented is acquired.

  Further, as a space portion communicating with the openings 14, 14, the outer shell 12 and the outer shell 12 and both sides of the lock seam portion 11 a formed on the connecting portion when the inner shell 11 is formed into a metal plate in a cylindrical shape are formed. Since the gaps 13 and 13 are formed between the inner shell 11 and the outer shell 12 in the axial direction, it is possible to save the trouble of forming the space portion in a state of extending in the axial direction. As a result, the effect of reducing the manufacturing cost can be obtained.

  Next, another embodiment of the present invention will be described. In the description of the other embodiments, the same components as those of the first embodiment are not shown or described, or the same reference numerals are given and the description thereof is omitted, and only the differences are described. To do.

The shell deformation prevention structure of the muffler main body of 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 on the connecting portion when the inner shell 11 is formed into a cylindrical shape by the space. , 13 is the same as the first embodiment, but in this second embodiment, the opening 15 is formed on the inner shell 11 side, so that the gaps 13 and 13 and the inner shell 11 inner side are formed. Is different from 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 notching a part of the plate material constituting the lock seam portion 11 a at both axial ends of the inner shell 11. An opening 15 is formed.

Next, operations and effects of the second embodiment will be described.
Since the second embodiment is configured as described above, the moisture contained in the exhaust gas at the time of cold start or the like is condensed by contacting each part in the low temperature exhaust pipe or the muffler main body, and the muffler main body is hollow. When water accumulates in the section and this water enters the gap between the inner shell 11 and the outer shell 12, the muffler body is heated with exhaust gas, and the water that has entered the gap vaporizes. Is formed between the inner shell 11 and the outer shell 12 through two gaps (space portions) 13 and 13 formed in the axial direction so as to form the lock seam portion 11a at both axial end portions of the inner shell 11. By cutting out a part of the plate material, the openings 15 and 15 formed in a state where the gap 13 and the inner shell 11 communicate with each other are immediately passed into 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, the effect that the deformation | transformation of the shell by the vaporization of the water which penetrate | invaded between the inner shell 11 and the outer shell 12 can be prevented is acquired.

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 embodiment, the openings 14 and 14 or the openings 15 and 15 are formed at both end portions in the axial direction of the outer shell 12, but only one place or three or more places may be provided at an arbitrary place.

  Further, in the embodiment, a space portion communicating with the openings 14 and 14 is formed by the gaps 13 and 13 formed in the axial direction between the both side portions of the lock seam portion 11a and the outer shell 12. For example, a gap forming body such as a wire or a square member is interposed between the inner shell 11 and the outer shell 12 along the axial direction, or the inner surface of the outer shell 12 is recessed along the axial direction. A space part may be formed.

  Moreover, in Example 2, although the opening part 15 which connects between the clearance gap 13 and the inner shell 11 was formed by notching a part of board | plate material which comprises the lock seam part 11a, inner shell 11 itself You may make it comprise an opening part with the hole opened in.

It is a top view which shows the muffler to which the shell deformation | transformation prevention structure of the muffler main body of Example 1 was applied. It is a longitudinal cross-sectional view in the II-II line of FIG. It is the A section expanded sectional view of FIG. It is the B section expanded sectional view of FIG. It is a longitudinal cross-sectional view in the VV line of FIG. FIG. 3 is a schematic diagram showing a muffler to which a shell deformation preventing structure for a muffler body of Example 1 is applied. It is an experimental data which shows the pressure reduction effect in the muffler to which the shell deformation | transformation prevention structure of the muffler main body of Example 1 was applied. It is a top view which shows the muffler to which the shell deformation | transformation prevention structure of the muffler main body of Example 2 was applied. It is a longitudinal cross-sectional view in the IX-IX line of FIG. It is a longitudinal cross-sectional view which shows the muffler main body of a prior art example.

Explanation of symbols

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 part 13 Clearance (space part)
14 Opening 15 Opening

Claims (2)

In the muffler body in which the cylindrical shell body part is composed 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 outer shell constituting the shell main body,
An opening communicating with the space is formed at a predetermined portion of the inner shell or the outer shell ,
The space portion is configured by a gap formed in the axial direction between the outer shell and the both sides of the lock seam portion formed on the connecting portion when the inner shell is formed into a cylindrical shape by sheet metal. ,
The opening is formed by notching a part of a plate material constituting the lock seam part of the inner shell or a part of a part overlapping the lock seam part of the plate material constituting the outer shell. The shell deformation prevention structure of the main body. The shell deformation prevention structure for a muffler body according to claim 1, wherein the opening is formed at both axial ends of the inner shell or the outer shell .

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