JP2013238160A - Exhaust muffling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase reduction effect of columnar resonance noise by a resonance chamber by allowing the resonance chamber in a muffler body to approach an antinode position of a standing wave as much as possible, in an exhaust muffling device disposed under a floor of a vehicle.SOLUTION: An exhaust gas introduction pipe 30 connected to a muffler body 10 is bent toward an end wall 13 at one side in the muffler body 10, has opening parts 34, 35 opened to an expansion chamber 24, and is provided with a branch pipe 36 bent toward an end wall 12 at the other side, upstream of the opening parts 34, 35. The branch pipe 36 is opened to a resonance chamber 25.

Description

  The present invention relates to an exhaust silencer that is arranged under the floor of a vehicle such as an automobile, and that enhances the silencing performance by enhancing the effect of reducing the air column resonance by the resonance chamber in the silencer body. About.

  The shell 10 includes a pair of end walls 11 and 12 on one side and the other side closing both ends of the shell 10, and partition walls 14 and 14 provided between the pair of end walls 11 and 12. 14 is connected to the silencer body 1 through the shell 10 between the pair of end walls 11 and 12, and the silencer body 1 in which the expansion chambers 20 and 21 are formed on one side and the resonance chamber 21R on the other side. The exhaust gas introduction pipes 2L and 2R for guiding the exhaust gas discharged from the engine to the expansion chambers 20 and 21 and the exhaust gas discharge pipe for discharging the exhaust gas in the expansion chambers 20 and 21 to the outside of the silencer body 1 5 and 5 are well known (see Patent Document 1 below).

JP 2010-255518 A

  By the way, the engine exhaust noise includes a combustion explosion sound of fuel in the engine cylinder, an air flow sound caused by the flow of exhaust gas, a standing wave air column resonance sound existing in the flow path of the exhaust gas, and the like.

  Among these, in order to reduce air column resonance noise, a resonance chamber having a resonance frequency tuned to the frequency of the standing wave at the antinode position (position where the amplitude is maximum) of the standing wave in the flow path of the exhaust gas. It is effective to provide a silencer equipped with an exhaust pipe, but there are other fuel tanks, cross members, side frames, rear axles, etc. Since the components are also arranged, there is a restriction on the arrangement of the muffler that is bulky, and the muffler may have to be arranged at a position deviated from the antinode position of the standing wave.

  In particular, in the exhaust silencer shown in Patent Document 1 described above, an exhaust gas introduction pipe disposed along the longitudinal direction of the vehicle passes through the shell between a pair of end walls and is connected to the silencer body. Therefore, in order to connect the exhaust gas introduction pipe and the silencer body, the pair of end walls face each other in the vehicle width direction, that is, the longitudinal direction of the silencer body is along the vehicle width direction. Preferably, the silencer body is provided with not only a resonance chamber but also an expansion chamber, and the silencer body is enlarged. Therefore, in the exhaust silencer described above, the silencer body must be arranged behind the vehicle. In many cases, the resonance chamber is arranged at a position biased downstream in the flow direction of the exhaust gas from the antinode position of the standing wave in the flow path of the exhaust gas. To increase the effect of reducing resonance There is a problem that Shii.

  In view of such a situation, the present invention provides the above-described exhaust silencer, in which the resonance chamber in the silencer main body approaches the antinode position of the standing wave as much as possible, thereby reducing the air column resonance noise by the resonance chamber. An object of the present invention is to provide a novel exhaust silencer that can improve the above-described problem and solve the above-mentioned problems.

In order to solve the above-mentioned problem, the invention described in claim 1 includes a shell, a pair of end walls on one side and the other side closing both ends of the shell, and a partition wall provided between the pair of end walls. A silencer body having an expansion chamber formed between one end wall and the partition wall, a resonance chamber formed between the other end wall and the partition wall, and a pair of end walls An exhaust gas introduction pipe for passing exhaust gas exhausted from the engine to the expansion chamber and exhausting the exhaust gas in the expansion chamber to the outside of the silencer main body. In an exhaust silencer comprising a discharge pipe,
The exhaust gas introduction pipe has an opening that is bent toward the end wall on one side and opens into the expansion chamber inside the silencer main body, and to the end wall on the other side upstream of the opening. A branch pipe that is bent in a direction is provided, and the branch pipe opens into the resonance chamber.

In order to solve the above-mentioned problem, the invention described in claim 2 includes a shell, a pair of end walls on one side and the other side closing both ends of the shell, and a partition wall provided between the pair of end walls. A silencer body having an expansion chamber formed between one end wall and the partition, a resonance chamber formed between the other end wall and the partition, and one end Exhaust gas introduction pipe that leads exhaust gas exhausted from the engine to the expansion chamber and penetrates the shell between the wall and partition wall, and exhaust gas in the expansion chamber to the outside of the silencer main body In an exhaust silencer equipped with an exhaust gas exhaust pipe for discharging,
The exhaust gas introduction pipe has an opening that bends toward one end wall inside the expansion chamber and opens into the expansion chamber, and is upstream of the opening and toward the other end wall. And the branch pipe is characterized in that it opens through the partition wall into the resonance chamber.

  According to the invention described in each of the claims, the resonance chamber is connected to the exhaust gas flow passage on the upstream side of the expansion chamber by the branch pipe provided in the exhaust gas introduction pipe. It is possible to approach the antinode position of the standing wave in the gas flow path, and the effect of reducing the air column resonance noise by the resonance chamber can be enhanced.

The side view which shows the relationship between the exhaust system of the vehicle engine provided with this invention exhaust silencer, and the standing wave which generate | occur | produces in an exhaust pipe 1 is an enlarged sectional view taken along the arrow 2 in FIG. Enlarged cross-sectional view along line 3-3 in FIG. Enlarged cross-sectional view along line 4-4 in FIG. Enlarged sectional view taken along line 5-5 in FIG. 3 is an enlarged cross-sectional view taken along line 6-6 in FIG. FIG. 7 is an enlarged sectional view taken along line 7-7. Schematic showing a comparison between the exhaust silencer of the embodiment and the exhaust silencer of the prior art

  Hereinafter, an embodiment in which the exhaust silencer of the present invention is implemented in an exhaust system connected to an automobile engine will be described with reference to FIGS.

  In the following description, front and rear, left and right, and top and bottom are based on the forward direction of the automobile.

  In FIG. 1, an exhaust pipe 1 that is mounted on a front part of a vehicle body B of an automobile and extends from an exhaust port of an engine E to a tail pipe 2 that is opened to the atmosphere is disposed under the floor of the vehicle body B of the automobile. The exhaust pipe 1 runs vertically under the floor in the front-rear direction, and in order from the upstream side to the downstream side, the primary catalyst CA1, the secondary catalyst CA2, the front silencer (prim muffler) PM, and the main silencer (main muffler). M and an auxiliary muffler (sub muffler) AM are connected in series, and a tail pipe 2 is connected to the downstream end of the auxiliary muffler AM. The main silencer M corresponds to the “exhaust silencer” according to the present invention.

  Therefore, the large-sized main silencer M that mainly silences the exhaust noise is disposed on the rear side of the vehicle for the reasons described above, and the flow of the exhaust gas at a position biased upstream of the main silencer M. An antinode position P of the standing wave W in the path is located.

  The exhaust gas discharged from the engine E and flowing through the exhaust pipe 1 is silenced through the front silencer PM, the main silencer M, and the auxiliary silencer AM, and then released to the atmosphere via the tail pipe 2.

  The main silencer M as an exhaust silencer according to the present invention is disposed in a direction in which the longitudinal direction along the longitudinal center axis LL crosses the longitudinal direction of the vehicle body B, that is, in the vehicle width direction. The silencer body 10 that forms the main body, the exhaust gas introduction pipe 30 that guides the exhaust gas from the engine E to the silencer body 10, and the exhaust gas that exhausts the exhaust gas in the expansion chamber 24 in the silencer body 10 to the outside. And a discharge pipe 40.

  2 and 3, the silencer main body 10 constitutes a housing of the main silencer M, and is airtightly fixed to an elliptical cylindrical shell 11 whose left and right end faces are open, and a left opening end of the shell 11. The left end wall 12 and the right end wall 13 hermetically fixed to the right opening end of the shell 11 are formed, and a sound deadening chamber 14 is formed therein. The main silencer M is suspended and supported by the vehicle body B via support means (not shown) with the longitudinal center axis L-L directed in the left-right direction.

  A pair of left and right inner partition walls 17 and 18 are fixed to a central portion of the inner surface of the silencer body 10 in the longitudinal direction so as to be substantially parallel to the left and right side end walls 12 and 13. Further, an outer partition wall 20 is fixed to a portion of the inner surface of the silencer body 10 near the right end wall 13 in the longitudinal direction in parallel with the pair of left and right inner partition walls 17 and 18. The right inner partition wall 18 and the outer partition wall 20 are respectively provided with a plurality of small holes 16 and 19 each having a punching hole (see FIGS. 6 and 7). By these small holes 16, 19, a first chamber 21 between the left and right inner partition walls 17, 18, a second chamber 22 between the right inner partition wall 18 and the outer partition wall 20, and a third chamber between the outer partition wall 20 and the right end wall 13. 23, and the first, second and third chambers 21, 22, and 23 form one expansion chamber 24, and a resonance chamber is provided between the left end wall 12 and the left inner partition wall 17. 25 is formed.

  The left inner partition wall 17 that divides the resonance chamber 25 and the expansion chamber 24 is provided with a plurality of small holes 15 (see FIG. 4) communicating with both the chambers 25, 24. Is for adjusting the resonance frequency of the resonance chamber 25 and is not necessarily required for the exhaust silencer according to the present invention.

  The right inner partition wall 18 and the outer partition wall 20 have a plurality of jig through holes 27 (see FIGS. 6 and 7) for assembling the partition walls 18 and 20 to the shell 11, respectively.

  An exhaust gas introduction pipe 30 for guiding exhaust gas into the silencer main body 10 is connected to the downstream end of the exhaust pipe 1 through a joint 5. The exhaust gas introduction pipe 30 passes through the shell 11 between the left and right inner partition walls 17 and 18 and is connected to the silencer body 10, and the right end wall between the left and right inner partition walls 17 and 18 in the silencer body 10. 13, and extends straight along the longitudinal direction of the silencer body 10, penetrates and is supported by the right inner partition wall 18 and the outer partition wall 20, and the open end 32 thereof is the third end. It is in the chamber 23 and is closed by a cap 33 to become a closed free end. Openings 34 and 35 made up of a number of punching holes are respectively opened in portions corresponding to the second chamber 22 and the third chamber 23 of the exhaust gas introduction pipe 30 and introduced into the exhaust gas introduction pipe 30. The exhaust gas flows through the openings 34 and 35 to the second chamber 22, the third chamber 23, and the first chamber 21 that constitute the expansion chamber 24.

  As shown in FIGS. 2 and 3, the exhaust gas introduction pipe 30 has a branch pipe 36 branched upstream of the openings 34 and 35 to the expansion chamber 24, and the branch pipe 36 is composed of a silencer body. 10, extends straight along the longitudinal direction of the silencer body 10 toward the left end wall 12, and an opening end 37 thereof opens into the resonance chamber 25. A part of the exhaust gas introduced into the exhaust gas introduction pipe 30 is made to flow to the resonance chamber 25 through the branch pipe 36 on the upstream side of the openings 34 and 35 to the expansion chamber 24. Yes.

  An exhaust gas exhaust pipe 40 that exhausts exhaust gas in the expansion chamber 24 to the outside of the silencer body 10 is penetrated and supported by the right inner partition wall 18, the right outer partition wall 20, and the right end wall 13 in the silencer body 10. The upstream end 41 is expanded in a divergent shape and is opened in the first chamber 21 constituting the expansion chamber 24. The downstream end 42 is opened to the outside and connected to the auxiliary silencer AM.

  Next, the operation of this embodiment will be described.

  Now, according to the operation of the engine E, the exhaust gas discharged from the engine E flows into the exhaust pipe 1 and sequentially flows through the primary and secondary catalysts CA1 and CA2 to purify harmful components such as Nx, CO, and HC. After that, it flows to the front silencer PM, where it is temporarily silenced, and flows through the exhaust gas introduction pipe 30 to the main silencer M as an exhaust silencer according to the present invention. After being made, it flows to the auxiliary silencer AM and is silenced auxiliary, and then is discharged to the outside through the tail pipe 2.

  By the way, most of the exhaust gas introduced into the silencer main body 10 from the exhaust gas introduction pipe 30 passes through the openings 34 and 35 to the second and third chambers 22 and 23 as shown by the arrow a in FIG. And flow. The exhaust gas in the third chamber 23 flows into the second chamber 22 through the small hole 19, and the exhaust gas in the second and third chambers 22 and 23 passes through the small hole 16 to the first chamber 21. The exhaust gas that flows into the first chamber 21 and flows into the first chamber 21 is discharged to the outside through the exhaust gas discharge pipe 40. Since the first, second and third chambers 21, 22, and 23 substantially form one expansion chamber 24, the exhaust gas in the expansion chamber 24 is expanded in stages and effectively silenced. Is done.

  A part of the exhaust gas introduced into the exhaust gas introduction pipe 30 passes through the branch pipe 36 upstream of the openings 34 and 35, that is, the expansion chamber 24, as shown by an arrow b in FIG. The sound flows into the resonance chamber 25 and is effectively silenced by resonance in the resonance chamber 25.

  In this embodiment, the resonance chamber 25 is connected to the exhaust gas flow path on the upstream side of the expansion chamber 24 by the branch pipe 36 provided in the exhaust gas introduction pipe 30. 25 can be brought closer to the antinode position P of the standing wave W in the flow path of the exhaust gas, whereby the effect of reducing the air column resonance noise by the resonance chamber 25 can be enhanced.

  FIG. 8 shows the positional relationship between the expansion chamber and the resonance chamber in the exhaust gas flow path between this embodiment (A) and the prior art (the one disclosed in Patent Document 1) (B).

  In the prior art, the resonance chamber is connected to the exhaust gas flow path via the communication pipe in the expansion chamber downstream of the exhaust gas introduction pipe with the flow of the exhaust gas. It is arranged at a position deviated downstream in the flow direction of the exhaust gas from the antinode position of the standing wave in the gas flow path, and the distance L2 from the resonance chamber to the antinode position becomes longer, and the air column resonance sound by the resonance chamber The reduction effect cannot be increased.

  On the other hand, in this embodiment, the resonance chamber is connected to the exhaust gas flow path upstream of the expansion chamber by the branch pipe provided in the exhaust gas introduction pipe. Approaching the antinode position of the standing wave in the path, the distance L1 from the resonance chamber to the antinode position is shorter than that of the prior art (L1 <L2), and the effect of reducing the air column resonance noise by the resonance chamber is enhanced. It is done.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, in the above embodiment, the exhaust gas introduction pipe 30 passes through the shell 11 between the right end wall 13 and the left inner partition wall 17 and is connected to the silencer body 10. The left end wall 12 and the left inner partition wall 17 may pass through the shell 11 and be connected to the silencer body 10. In this case, the branch pipe 36 does not penetrate the left inner partition wall 17.

10 Silencer body 11 Shell 12 End wall on the other side (left end wall)
13 One end wall (right end wall)
17 Bulkhead (Left inner bulkhead)
24 expansion chamber 25 resonance chamber 30 exhaust gas introduction pipe 34 opening 35 opening 36 branch pipe 40 exhaust gas exhaust pipe E engine

Claims (2)

A shell (11), a pair of end walls (13, 12) on one side and the other side closing both ends of the shell (11), and a partition wall (17) provided between the pair of end walls (13, 12) Between the end wall (13) on one side and the partition wall (17), and between the end wall (12) on the other side and the partition wall (17). A silencer body (10) having a resonance chamber (25) formed in
Between the pair of end walls (13, 12), the shell (11) passes through and is connected to the silencer body (10), and exhaust gas discharged from the engine (E) is guided to the expansion chamber (24). An exhaust gas introduction pipe (30);
An exhaust gas exhaust pipe (40) for exhausting exhaust gas in the expansion chamber (24) to the outside of the silencer body (10);
In the exhaust silencer equipped with
The exhaust gas introduction pipe (30) has openings (34, 35) that are bent toward the end wall (13) on one side and open to the expansion chamber (24) inside the silencer body (10). And a branch pipe (36) bent toward the other end wall (12) on the upstream side of the opening (34, 35), and the branch pipe (36) opens into the resonance chamber (25). An exhaust silencer, characterized by: A shell (11), a pair of end walls (13, 12) on one side and the other side closing both ends of the shell (11), and a partition wall (17) provided between the pair of end walls (13, 12) Between the end wall (13) on one side and the partition wall (17), and between the end wall (12) on the other side and the partition wall (17). A silencer body (10) having a resonance chamber (25) formed in
Between the end wall (13) on one side and the partition wall (17), the shell (11) is connected to the silencer body (10), and the exhaust gas discharged from the engine (E) is expanded. An exhaust gas introduction pipe (30) leading to the chamber (24);
An exhaust gas exhaust pipe (40) for exhausting exhaust gas in the expansion chamber (24) to the outside of the silencer body (10);
In the exhaust silencer equipped with
The exhaust gas introduction pipe (30) has openings (34, 35) that are bent toward the end wall (13) on one side inside the expansion chamber (24) and open to the expansion chamber (24). And a branch pipe (36) bent toward the other end wall (12) upstream of the opening (34, 35), and the branch pipe (36) penetrates the partition wall (17). An exhaust silencer characterized by opening to the resonance chamber (25).

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