JP3199630U - Silencer for internal combustion engine - Google Patents

Abstract

Provided is a silencer for an internal combustion engine that has a simple structure, less man-hours and costs, and prevents the inner pipe from being melted when the inner pipe is welded to a shell, while reducing the weight of the inner pipe. A silencer for an internal combustion engine is formed by welding an inner pipe to a shell. The inner pipe 20 is formed of a stainless steel plate 21 having a thickness of 0.4 to 0.8 mm, and an end 23 of the inner pipe 20 welded to the shell 10 is a double cylinder portion on which the stainless steel plates 21 are stacked. The remaining part 24 of the pipe 20 is a single cylinder part of the stainless steel plate 21. The length of a double cylinder part is 5-40 mm. [Selection] Figure 1

Description

  The present invention relates to a silencer provided in an exhaust system of an internal combustion engine.

  Many silencers for internal combustion engines include a shell (outer cylinder) and an inner pipe extending through the shell. To fix the shell and the inner pipe, a short cylindrical burring part is formed in the shell, the inner pipe is inserted into the burring part, and the end of the inner pipe is welded to the burring part over the entire circumference of the inner pipe. (Patent Document 1).

JP 2006-170151 A

  In recent years, automobiles have been required to be lighter in order to improve fuel consumption, and mufflers have been required to be lighter. The present inventor has studied thinning of the inner pipe as one means to meet this demand. Many of the conventional inner pipes are formed of a stainless steel plate having a thickness of 1.0 to 1.2 mm, and if this is thinned, weight reduction can be expected.

  However, as described above, since the end portion of the inner pipe is welded to the burring portion over the entire circumference, there is a possibility that it will melt during welding if the thickness is reduced. For this reason, it has been difficult to reduce the weight of the inner pipe while preventing the inner pipe from being melted.

  Therefore, the object of the present invention is to reduce the weight of the inner pipe while preventing the inner pipe from being melted when the inner pipe is welded to the shell with a simple structure, less man-hours and cost, and thus the silencer for the internal combustion engine. The goal is to reduce weight.

  The present invention provides a silencer for an internal combustion engine in which an inner pipe is welded to a shell, the inner pipe is formed of a stainless steel plate having a thickness of 0.4 to 0.8 mm, and an end portion of the inner pipe welded to the shell is It is a double cylinder part on which stainless steel plates are stacked, and the remaining part (intermediate part other than the end part) of the inner pipe is a single cylinder part of the stainless steel sheet.

  According to the present invention, a stainless steel plate having a thickness of 0.4 to 0.8 mm is doubled at the end of the inner pipe to be welded to the shell. It is possible to reduce the weight of the pipe while preventing the pipe from being melted.

  Here, it is preferable that the stainless steel plate is folded and overlapped from the end edge in that the double tube portion has a small number of materials. The bending from the edge of the stainless steel plate is preferably the bending to the inner peripheral side of the inner pipe from the viewpoint of ease of making, and the inner pipe is reduced from the point of eliminating the inner peripheral step and reducing the airflow resistance. It is preferable to bend to the outer peripheral side.

  Further, the double cylindrical portion may be formed by fitting another ring-shaped stainless steel plate on the inner peripheral side or the outer peripheral side of the stainless steel plate by fitting.

  The double cylinder part is preferably spot welded while being overlapped. This is in order not to leave the overlap.

  The double cylindrical portion is preferably brazed between the overlapping portions. This is in order not to leave the overlap.

  The reason why the thickness of the stainless steel plate is 0.4 to 0.8 mm is that when the thickness is less than 0.4 mm, the strength is insufficient and deformation easily occurs, and when the thickness exceeds 0.8 mm, the effect of reducing the weight is reduced. The thickness is more preferably 0.45 to 0.55 mm.

  The length of the double cylinder part (length in the length direction of the inner pipe) is not particularly limited, but is preferably 5 to 40 mm. This is because if it is less than 5 mm, melt-down during welding tends to occur, and if it exceeds 40 mm, the effect of reducing the weight is reduced. The length is more preferably 10 to 30 mm.

  Although the structure of the junction part of a shell and an inner pipe is not specifically limited, The aspect with which the burring part formed in the shell and the edge part of the inner pipe were welded can be illustrated.

  According to the present invention, the inner pipe is reduced in weight while preventing the inner pipe from being melted when the inner pipe is welded to the shell with a simple configuration, less man-hours and costs, thereby reducing the weight of the silencer for the internal combustion engine. Can be achieved.

It is sectional drawing when the silencer for internal combustion engines of an Example is mounted in a front pipe and a tail tail. (A) is a perspective view of a stainless steel plate used for the inner pipe of the silencer, (b) is a perspective view when the stainless steel plate is bent from the end edge and the end portions are overlapped, and (c) is the stainless steel plate. The perspective view of the inner pipe formed by rolling a steel plate into a pipe shape from the side edge, (b) is a sectional view of the inner pipe. The other example of the inner pipe used for the silencer is shown, (a) is a sectional view of another example, (b) is a sectional view of another example 2, and (c) is a sectional view of another example 3. The other example 4 of the inner pipe used for the silencer is shown, (a) is a front view of the brazing material to be used, (b) is a cross-sectional view of the inner pipe in which the brazing material is arranged, and (c) is the brazing material. It is sectional drawing of the brazed inner pipe.

  A silencer for an internal combustion engine is formed by welding an inner pipe to a shell. The inner pipe is formed of a stainless steel plate having a thickness of 0.4 to 0.8 mm, and the end portion of the inner pipe welded to the shell is a double tube portion in which the stainless steel plate is bent and overlapped from the end edge, The remaining part of the inner pipe is a single cylinder part of the stainless steel plate. The length of a double cylinder part shall be 5-40 mm. The bending from the edge of the stainless steel plate is to the inner peripheral side of the inner pipe.

  An embodiment in which the present invention is embodied in a silencer for an internal combustion engine of an automobile will be described with reference to FIGS. 1 and 2. The silencer 1 for an internal combustion engine includes a shell 10 and an inner pipe 20, and when mounted on an automobile, a front pipe 2 extending from the internal combustion engine is connected to one end of the inner pipe 20, and a tail pipe 3 is connected to the other end. .

  The shell 10 includes a cylindrical portion 11 and an end plate 12 that closes each end of the cylindrical portion 11, and the cylindrical portion 11 and the end plate 12 are joined by a joining portion 13. The end plate 12 is formed with a short cylindrical burring portion 14 through which the inner pipe 20 is inserted. Each part of the shell 10 is formed of a stainless steel plate, but may be formed of a metal plate such as another steel plate.

  The inner pipe 20 has a cylindrical shape, is inserted through the burring portion 14, extends through the shell 10, and protrudes from the burring portion 14 to the outside of the shell 10 by several mm to tens of mm. The inner pipe 20 is formed of a stainless steel plate 21 having a thickness of 0.5 mm, and a plurality of through holes 22 are formed at locations extending in the shell 10. Both end portions 23 of the inner pipe 20 that overlap with each burring portion 14 and are welded to the burring portion 14 are double cylindrical portions in which a stainless steel plate 21 is folded and overlapped from the end edge to the inner peripheral side of the inner pipe 20. Yes, the remaining part 24 of the inner pipe is a single cylinder part of the stainless steel plate.

  The dimensions and weight of the inner pipe 20 are, for example, an outer diameter of 48.6 mm, a length of 300 mm (the length of each end 23 is 20 mm, the length of the remaining portion 24 is 260 mm), and a weight of 202 g. As a comparative example, an inner pipe having an outer diameter of 48.6 mm and a length of 300 mm, which is formed of a stainless steel plate having a thickness of 1.0 mm that has been conventionally used, has a weight of 352 g. Therefore, compared with this comparative example, the present embodiment was reduced in weight by about 43%.

  As shown in FIG. 2A to FIG. 2B, the inner pipe 20 is formed by bending a flat stainless steel plate 21 from the end edge along a fold line 25 and overlapping the end portion 23 in a double-layered manner. 2 As shown by the change from (b) to (c), the stainless steel sheet 21 can be bent from the side edge into a pipe shape, and can be manufactured with a small number of man-hours by welding the abutted side edges, It doesn't cost much.

  Welding by arc welding or the like between the burring portion 14 and the end portion 23 of the inner pipe 20 (more specifically, a portion of the end portion 23 protruding from the burring portion 14 to the outside of the shell 10) over the entire circumference of the end portion 23. Joined by the portion 26. Even if a stainless steel plate 21 having a thickness of 0.5 mm, which is much thinner than before, is used, the end 23 of the inner pipe 20 is a double cylinder that is folded, so that the end 23 melts during welding. Never fall.

  Further, at the time of mounting in an automobile, the end of the front pipe 2 is inserted into one end 23 of the inner pipe 20, and the end of the tail pipe 3 is inserted into the other end 23, respectively. And the end 23 and the tail pipe 3 are joined by a welded portion 27 by arc welding or the like over the entire circumference of the end 23. Even at the time of this welding, the end 23 of the inner pipe 20 is not melted down for the above reason.

  A chamber 4 is formed between the inner surface of the shell 10 and the outer peripheral surface of the inner pipe 20, and the chamber 4 and the inner pipe 20 communicate with each other through the through-hole 22, so that a predetermined frequency of exhaust gas passing through the inner pipe 20 is obtained. Resonance is generated to reduce exhaust noise. Further, a sound absorbing material 5 such as glass wool is interposed in the room 4 as necessary, and exhaust noise can also be reduced by the sound absorbing action.

  As described above, according to the silencer for an internal combustion engine of the present embodiment, the inner pipe 20 can be prevented from being burned out when the inner pipe 20 is welded to the shell 10 with a simple configuration, less man-hours and costs. It is possible to reduce the weight of the pipe 20 and thereby reduce the weight of the silencer for the internal combustion engine.

  In addition, this invention is not limited to the said Example, In the range which does not deviate from the meaning of invention, it can change suitably and can be actualized.

(1) Like the inner pipe 20 of the other example 1 shown in FIG. 3A, the double cylinder portion may be one in which the stainless steel plate 21 is folded from the edge to the outer peripheral side of the inner pipe 20 and overlapped. .

(2) Like the inner pipe 20 of another example 2 shown in FIG. 3 (b), the double tube portion is another short (2) on the inner peripheral side or the outer peripheral side of the stainless steel plate 21 that is not bent at the end. A ring-shaped stainless steel plate 28 (the length of the heavy cylinder portion) may be overlapped by fitting.

(3) Like the inner pipe 20 of another example 3 shown in FIG. 3C, the double cylinder portion may be spot welded by resistance welding or the like while being overlapped. Reference numeral 29 denotes the welded portion. In each double cylinder part, the number of the welding parts 29 may be one or more.

(4) Like the inner pipe 20 of another example 4 shown in FIG. 4C, the double cylinder portion may be brazed while being overlapped. Reference numeral 31 indicates the brazed portion by a bold line. For brazing, a ring-shaped brazing material 30 made of silver brazing, nickel alloy or the like as shown in FIG. 9A is arranged on the mating side of the double cylinder portion as shown in FIG. The inner pipe 20 is put in a furnace and heated, and the molten brazing material 30 is allowed to permeate while the double cylinder portions are stacked.

(5) The shell may be one in which the cylindrical portion and the end plate are integrally formed.
(6) The portion of the shell where the end of the inner pipe is welded may be other than the burring portion.
(7) It is possible to embody a silencer in which only one end of the inner pipe is welded to the shell and the other end ends in the shell and opens. Only the above-mentioned end portion may be the above-described double tube portion.

DESCRIPTION OF SYMBOLS 1 Silencer for internal combustion engines 2 Front pipe 3 Tail pipe 4 Room 5 Sound absorbing material 10 Shell 11 Tube part 12 End plate 13 Joint part 14 Burring part 20 Inner pipe 21 Stainless steel plate 22 Through hole 23 End part 24 Remaining part 25 Folding line 26 Weld part 27 Welded portion 28 Another stainless steel plate 29 Welded portion 30 Brazing material 31 Brazed portion

Claims (8)

In the silencer (1) for an internal combustion engine in which the inner pipe (20) is welded to the shell (10),
The inner pipe (20) is formed of a stainless steel plate (21) having a thickness of 0.4 to 0.8 mm,
The end part (23) of the inner pipe (20) welded to the shell (10) is a double cylinder part on which the stainless steel plate (21) is superimposed,
The silencer for an internal combustion engine, wherein the remaining part (24) of the inner pipe (20) is a single cylinder part of the stainless steel plate (21).   2. The silencer for an internal combustion engine according to claim 1, wherein the double cylindrical portion is formed by folding the stainless steel plate (21) from the end edge to the inner peripheral side or the outer peripheral side of the inner pipe (20).   2. The muffler for an internal combustion engine according to claim 1, wherein the double cylindrical portion is formed by stacking another ring-shaped stainless steel plate (28) by fitting on the inner peripheral side or the outer peripheral side of the stainless steel plate (21). vessel.   The silencer for an internal combustion engine according to any one of claims 1 to 3, wherein the double cylinder portion is spot welded while being overlapped.   The silencer for an internal combustion engine according to any one of claims 1 to 3, wherein the double cylinder portion is brazed between overlapping portions.   The silencer for an internal combustion engine according to any one of claims 1 to 5, wherein the stainless steel plate (21) has a thickness of 0.45 to 0.55 mm.   The silencer for an internal combustion engine according to any one of claims 1 to 6, wherein the length of the double cylinder portion is 5 to 40 mm.   The silencer for an internal combustion engine according to any one of claims 1 to 7, wherein a burring portion (14) formed in the shell (10) and an end portion (23) of the inner pipe (20) are welded.

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