JP2004332643A - Muffler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide appropriate exhaust characteristics according to a driving condition by reducing a size without deteriorating muffler performance. <P>SOLUTION: In the muffler including an exhaust pipe directly or indirectly connected to an exhaust port of an internal combustion engine, a finisher arranged in a lower stream side of exhaust gas flow direction on an extended line of the exhaust pipe, and a muffling mechanism provided between the exhaust pipe and the finisher, a pulsation reducing passage constructing a complicated route is formed by providing a plurality of inner pipes of different diameters in the muffling mechanism. The exhaust pipe is communicated to an end part in an upper stream side of the exhaust gas flow of an inner pipe arranged in an innermost part and the finisher is communicated to an end part in the lower stream side of the exhaust gas flow. An exhaust gas pressure regulating valve relieving exhaust gas when pressure of exhaust gas exceeds a predetermined value is provided at the end part in the lower stream side of the exhaust gas flow of the inner pipe to change exhaust characteristics according to the driving condition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a muffler for exhaust of an internal combustion engine mounted on an automobile or the like.
[0002]
[Prior art]
Conventional techniques relating to a muffler (muffler) include an operating mechanism including a casing, a gas suction pipe to the casing, a pipe incorporated in the casing, a diaphragm, a support elastic body, a piston rod, and a pressure connection. A muffler, comprising: a pressure overpressure vessel, a valve closing element associated with the piston rod, and a pressure conduit for transmitting the total gas pressure to the overpressure side of the diaphragm, wherein the operation vessel has a plurality of chambers separated by a diaphragm. Some diaphragms are supported by elastic bodies, each chamber has a pressure connection, and another pressure conduit transmits static gas pressure to the low pressure side of the diaphragm (see Patent Document 1). It is stated that this makes it possible to provide a silencer having a variable attenuation characteristic curve without providing an external control device.
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 9-166010
[Problems to be solved by the invention]
In the above conventional silencer, as shown in FIG. 1 of Patent Literature 1, a plurality of pipes 3.1 and 1 through which gas flows between the inside and outside of the casing 2 and the three expansion chambers 21, 23, and 35. 3.2, 3.3, 3.4 are arranged in parallel or vertically. For this reason, there is a problem that the entire apparatus must be large.
[0005]
Therefore, an object of the present invention is to provide a muffler that achieves downsizing without impairing the muffling performance and realizes appropriate exhaust characteristics according to a running state.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides an exhaust pipe directly or indirectly connected to an exhaust port of an internal combustion engine, a finisher disposed on an extension of the exhaust pipe on the downstream side in the exhaust direction, A muffler comprising a muffling mechanism provided between a pipe and the finisher, wherein a body pipe constituting an outermost part of the muffling mechanism and a predetermined distance from an inner wall of the body pipe are provided. A first inner pipe provided therein, a second inner pipe provided at a predetermined distance from an inner wall of the first inner pipe, and a predetermined distance from an inner wall of the second inner pipe; A third inner pipe having an exhaust-direction upstream end that communicates with the exhaust pipe and an exhaust-direction downstream end that communicates with the finisher, the body pipe, and the first inner pipe. A pipe, the second inner pipe, the third inner pipe, and a predetermined partitioning member are defined outside the third inner pipe, and an exhaust-direction upstream end is defined by the third inner pipe. A pulsation reducing passage communicating with the internal space and having a downstream end in the exhaust direction communicating with the finisher; and a downstream end in the exhaust direction of the third inner pipe, the pressure of the exhaust gas being equal to or higher than a predetermined value. And an exhaust pressure regulating valve that is opened when the pressure becomes negative.
[0007]
As described above, in the silencer of the present invention, the first, second, and third inner pipes having different diameters are sequentially provided inside the body pipe, and the space defined between these members is exhausted. This is a gas flow passage, that is, a pulsation reduction passage, whereby the size can be reduced without impairing the noise reduction performance. When the pressure of the exhaust gas from the internal combustion engine becomes equal to or higher than a predetermined value, the exhaust pressure regulating valve is opened, and the exhaust gas is sent to the finisher by short-circuiting the pulsation reducing passage. As a result, the exhaust resistance is reduced, and the engine output is improved. Further, in the present invention, since the exhaust pressure adjusting valve is provided at the downstream end of the third inner pipe in the exhaust direction, that is, immediately before the finisher, the exhaust gas flowing out of the exhaust pipe is subjected to the exhaust pressure adjusting valve. Regardless of the open / closed state of the valve, it is first expanded by the space in the third inner pipe. Thereby, the silencing performance can be improved.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. A muffler 1 shown in FIGS. 1 and 2 includes an exhaust pipe 2 directly or indirectly connected to an exhaust port of an internal combustion engine, a finisher 3 disposed on an extension of the exhaust pipe 2 on the downstream side in the exhaust direction, A muffling mechanism 4 provided between the exhaust pipe 2 and the finisher 3 for short-circuiting an exhaust path formed between the exhaust pipe 2 and the finisher 3 when the pressure of the exhaust gas exceeds a predetermined value. The exhaust pressure adjusting valve 5 is provided.
[0009]
The muffling mechanism 4 is a cylindrical body pipe 10 constituting the outermost shell, a cylindrical member having a smaller diameter than the body pipe 10, a first inner pipe 11 provided inside the body pipe 10, a first inner pipe, A second inner pipe 12 provided inside the first inner pipe 11; a second cylindrical member having a smaller diameter than the second inner pipe 12; It has a third inner pipe 13 provided inside the pipe 12.
[0010]
The body pipe 10 has a front end 10a connected to the exhaust pipe 2 via a front cover member 15, and a rear end 10b connected to the finisher 3 via a rear cover member 16. I have. The third inner pipe 13 has a front end 13a connected to a rear end 2a of the exhaust pipe 2 and a rear end 13b connected to a front end of a pressure regulating valve 5 described later. The second inner pipe 12 has a rear end portion 12b connected to a front end portion 3a of the finisher 3 and a caulking portion 12c formed at a portion upstream of the rear end portion 12b in the exhaust direction. It is fixed to the third inner pipe 13. The first inner pipe 11 is fixed to the third inner pipe 13 by a fixed closing member 17 disposed in the vicinity of the front end thereof, and the first inner pipe 11 is formed by the caulking portion 11c formed in the vicinity of the rear end thereof. 2 is fixed to the inner pipe 12.
[0011]
The front end 12a of the second inner pipe 12 is located rearward (closer to the finisher 3) than the fixed closing member 17. The fixed closing member 17 is a wall-shaped member extending over the entire periphery of the third inner pipe 13, and closes a space 20 defined between the first and third inner pipes 11, 13. The caulked portions 11c and 12c are formed in a plurality at predetermined intervals in the circumferential direction, and do not prevent passage of exhaust gas. A plurality of through holes 22 are formed in a portion of the third inner pipe 13 closer to the front end 13a than the fixed closing member 17.
[0012]
The exhaust pressure adjusting valve 5 is disposed at the rear end 13 b of the third inner pipe 13, that is, immediately before the finisher 3, and includes a fixing member 30, a rod member 31, a valve body 32, a valve seat 33, and a spring 34. , A spring receiver 35 and an urging force adjusting means 36.
[0013]
The fixing member 30 is fixed to the rear end 13b of the third inner pipe 13, has a shape through which exhaust gas can pass, and the front end of the rod member 31 is fixed. A spring receiver 35 is fixed to the rear end of the rod member 31. The valve body 32 is a substantially conical member, and is fixed to the rod member 31 so as to be slidable in the axial direction. The valve seat 33 is provided at a rear end of the fixing member 30 and has a shape with which the valve body 32 abuts airtightly. The spring 34 has a front end fixed to the inner surface of the valve body 32 and a rear end fixed to the spring receiver 35. The urging force adjusting means 36 adjusts the urging force of the spring 34 by sliding the fixed position of the spring receiver 35 along the rod member 31 and has a structure using a hexagon wrench or the like. .
[0014]
According to the silencer 1 having the above configuration, when the pressure of the exhaust gas from the internal combustion engine is smaller than the urging pressure (and the atmospheric pressure) of the spring 34 (during normal running), as shown in FIG. When the body 32 is closed, the exhaust gas flowing out of the exhaust pipe 2 first enters the first space S1 defined inside the third inner pipe 13 as shown by the arrow A, and then passes through the first space S1. The hole enters the second space S2 defined by the third inner pipe 13, the first inner pipe 11, the fixed closing member 17, the front cover 15, and the like via the hole 22, and the body pipe 10 and the second It passes through a third space S3 defined between the first inner pipe 11 and the like, and passes through a fourth space S4 defined between the first inner pipe 11 and the second inner pipe 12. , The second inner pipe 12 and the third inner pipe Through the fifth space S5, is defined between the type 13, it is discharged to the outside via the finisher 3. As described above, in the exhaust path during normal traveling, the exhaust gas follows the complicated pulsation reducing passage constituted by the spaces S1, S2, S3, S4, and S5, and the pulsation is sufficiently suppressed.
[0015]
On the other hand, when the pressure of the exhaust gas from the internal combustion engine is higher than the biasing pressure (and atmospheric pressure) of the spring 34 (during high-power running), the valve 32 moves to the open position as shown in FIG. Then, as shown by the arrow A ', the exhaust gas short-circuits the space after the space S2 in the pulsation reducing passage and directly reaches the finisher 3 from the first space S1. Therefore, the exhaust resistance is reduced, and the engine output is improved.
[0016]
Further, since the exhaust pressure adjusting valve 5 is provided at the downstream end of the third inner pipe 13 in the exhaust direction, that is, immediately before the finisher 3, the exhaust gas flowing out of the exhaust pipe 2 is discharged from the exhaust pipe 2 Regardless of the open / closed state of 5, the first space S1 is expanded. Thereby, the silencing performance can be improved.
[0017]
【The invention's effect】
As described above, according to the present invention, inner pipes having different diameters are sequentially provided inside the body pipe, and the space defined between these members is defined as the exhaust gas flow path, that is, the pulsation reduction path. Therefore, the size can be reduced without deteriorating the noise reduction performance. When the pressure of the exhaust gas from the internal combustion engine becomes equal to or higher than a predetermined value, the exhaust pressure regulating valve is opened, and the exhaust gas is sent to the finisher by short-circuiting the pulsation reducing passage. As a result, the exhaust resistance is reduced, and the engine output can be improved. Furthermore, since the exhaust pressure regulating valve is provided at the downstream end of the third inner pipe in the exhaust direction, that is, immediately before the finisher, the exhaust gas flowing out of the exhaust pipe is affected by the open / close state of the exhaust pressure regulating valve. First, it is expanded by the space in the third inner pipe. Thereby, a silencer excellent in silencing performance can be provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a structure of a silencer according to an embodiment of the present invention and a state during normal running.
FIG. 2 is a cross-sectional view showing a structure of the silencer according to the embodiment of the present invention and a state during high-power running.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 muffler 2 exhaust pipe 3 finisher 4 muffler 5 exhaust pressure control valve 10 body pipe 11 first inner pipe 12 second inner pipe 13 third inner pipe 22 through hole 32 valve body 34 spring S1 first space S2 second space S3 third space S4 fourth space S5 fifth space

Claims (1)

An exhaust pipe connected directly or indirectly to an exhaust port of the internal combustion engine, a finisher disposed on the extension of the exhaust pipe on the downstream side in the exhaust direction, and a silencing mechanism provided between the exhaust pipe and the finisher And a muffler configured with
A body pipe constituting the outermost shell of the silencing mechanism,
A first inner pipe provided at a predetermined interval from an inner wall of the body pipe;
A second inner pipe provided at a predetermined distance from an inner wall of the first inner pipe;
A third inner pipe which is provided at a predetermined distance from an inner wall of the second inner pipe and whose upstream end in the exhaust direction communicates with the exhaust pipe and whose downstream end in the exhaust direction communicates with the finisher; Pipe and
The body pipe, the first inner pipe, the second inner pipe, the third inner pipe, and a predetermined partitioning member are defined outside the third inner pipe, and are located at an upstream end in an exhaust direction. A pulsation reducing passage having a portion communicating with the space inside the third inner pipe and a downstream end in the exhaust direction communicating with the finisher;
A muffler provided at a downstream end of the third inner pipe in the exhaust direction, the exhaust pressure regulating valve being opened when an exhaust gas pressure becomes equal to or higher than a predetermined value.

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