JP2002303117A - Muffler for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a muffler for an internal combustion engine capable of reducing noise with low frequency even when it is small. SOLUTION: This muffler comprises a resonance duct 12 that is disposed in an exhaust flow channel of exhaust gas discharged from the internal combustion engine and opens at one end to a resonance chamber 2 formed in a muffler body 1 of the muffler for the internal combustion engine for reducing the exhaust noise and an exhaust duct 14 interposed in the exhaust flow channel. The other end of the resonance duct 12 is opened to the exhaust duct 14, and the resonance duct 12 is formed along the exhaust duct 14. The inside of a passage pipe 4 is partitioned by a partition 10 axially, one is the resonance duct 12, and the other is the exhaust duct 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a muffler for an internal combustion engine which is provided in an exhaust passage of exhaust gas discharged from an internal combustion engine and reduces exhaust noise.

[0002]

2. Description of the Related Art Conventionally, an exhaust system of a vehicle equipped with an internal combustion engine has a catalytic converter 200 for purifying exhaust gas and a main muffler 2 for reducing exhaust noise as shown in FIG.
02 and a sub-muffler 204. When the main muffler 202 has a large capacity and is difficult to mount, the sub muffler 204 is disposed between the catalytic converter 200 and the main muffler 202.
Alternatively, unlike the case of FIG. 15, the main muffler 202
When the rear is longer than the main muffler 202, the sub-muffler 204 may be disposed downstream of the main muffler 202.

As shown in FIG. 16, the sub muffler 204 is provided with an exhaust pipe 210 penetrating a resonance chamber 208 formed in the muffler main body 206, and one end of the sub muffler 204 is connected to the exhaust pipe 210 in the resonance chamber 208. Provided resonance tube 212 is provided. The other end of the resonance tube 212 is opened in the resonance chamber 208. The sub muffler 204 resonates at a specific frequency, thereby reducing exhaust noise.

The resonance frequency f at which the sub-muffler 204 resonates
Is generally represented by the following Helmholtz equation:
Here, c is the speed of sound, V is the volume of the resonance chamber 208, S is the cross-sectional area of the resonance pipe 212, and L is the length of the resonance pipe 212.

[0005]

(Equation 1) The main muffler 202 is also provided with a resonance chamber and a resonance tube in the same manner to reduce exhaust noise by resonance.

[0006]

However, in such a conventional apparatus, in order to effectively reduce the primary muffled sound at a rotational speed of the internal combustion engine of 2000 rpm or less, the volume V of the resonance chamber 208 must be increased. The length of the resonance tube 212 in the resonance chamber 208 must be increased, and there is a problem that the sub-muffler 204 and the main muffler 202 become large.

An object of the present invention is to provide a muffler for an internal combustion engine that can reduce low frequency noise even if it is small.

[0008]

In order to achieve the above object, the present invention takes the following means to solve the problem. That is, in a muffler for an internal combustion engine that is provided in an exhaust passage of exhaust gas discharged from the internal combustion engine and reduces exhaust noise,
A resonance pipe having one end opened to a resonance chamber formed in the muffler main body, and an exhaust pipe interposed in the exhaust flow path, the other end of the resonance pipe being opened to the exhaust pipe, A muffler for an internal combustion engine, wherein the resonance pipe is formed along the exhaust pipe.

[0009] The inside of the passage pipe may be partitioned by a partition plate along the axial direction, and one may be the resonance pipe and the other may be the exhaust pipe. Alternatively, the inner pipe and the outer pipe may be arranged in a double tube, the inner pipe may be used as an exhaust pipe, and the space between the outer pipe and the inner pipe may be used as a resonance pipe. Further, an inner pipe penetrating the resonance chamber in the muffler main body is provided to form the exhaust pipe, and an outer pipe covering the inner pipe in the resonance chamber is provided in the resonance chamber in a double tubular shape. The resonance pipe is formed between the pipe and the outer pipe, and a through-hole communicating with the resonance chamber is provided at one end of the outer pipe, and a through-hole is formed in the inner pipe at the other end of the outer pipe. The configuration may be formed.

[0010] Further, a passage pipe penetrating the resonance chamber in the muffler body is provided, and the passage pipe is partitioned by a partition plate along an axial direction to form the resonance pipe and the exhaust pipe. The resonance chamber may be divided into two by a partition, and the resonance pipe may be divided into two by a partition, and a through-hole communicating each resonance chamber and the resonance pipe may be formed in the passage pipe. . A partition may be provided to partition the inside of the muffler body into the resonance chamber and the sound absorbing chamber, and a large number of small holes communicating the exhaust pipe and the sound absorbing chamber may be formed in the passage pipe. Alternatively, a structure in which a sound absorbing tube that covers the passage tube is provided in the muffler main body to form a sound absorbing room, and a number of small holes communicating the sound absorbing room and the exhaust line are formed in the passage tube. Good.

In addition, an inlet pipe and an outlet pipe are connected to the muffler main body, the muffler main body is partitioned into the resonance chamber and two expansion chambers, and the inlet pipe is provided along an axially extending partition plate. Partitioning the resonance pipe and the exhaust pipe, connecting the resonance pipe to the resonance chamber, connecting the exhaust pipe to one of the expansion chambers, and connecting the outlet pipe to the other expansion chamber. May be connected.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, reference numeral 1 denotes a muffler main body of a sub-muffler.
Is formed, and a passage pipe 4 penetrating the resonance chamber 2 in the muffler main body 1 is provided. An exhaust pipe 6 on the upstream side is connected to one end of the passage pipe 4, and an exhaust pipe 8 on the downstream side is connected to the other end of the passage pipe 4. It is interposed in the exhaust flow path of the exhaust gas to be discharged.

Along the axial direction of the passage tube 4, the passage tube 4 is
A partition plate 10 is provided for partitioning into two. In the present embodiment, as shown in FIG. 2, the cross-sectional shape of the passage pipe 4 is substantially elliptical, and the partition plate 10 is arranged at the center of the passage pipe 4 in the axial direction, and divides the inside of the passage pipe 4 almost equally. Thus, a resonance pipe 12 and an exhaust pipe 14 are formed.

On the upstream side of the passage pipe 4, the resonance pipe 12 and the exhaust pipe 14 partitioned by the partition plate 10 are both connected to the exhaust pipe 6 on the upstream side. On the downstream side of the passage pipe 4,
The partition plate 10 is bent toward the resonance pipe 12 to close the resonance pipe 12, and the exhaust pipe 14 is formed to communicate with the exhaust pipe 8 on the downstream side. A through-hole 16 is formed in the passage pipe 4 in the resonance chamber 2. One end of the resonance pipe 12 is opened to the resonance chamber 2, and the other end of the resonance pipe 12 is opened to the exhaust pipe 6. ing.

Next, the operation of the muffler for an internal combustion engine according to the first embodiment will be described. Exhaust gas discharged from an internal combustion engine (not shown) passes through an exhaust pipe 14 from an exhaust pipe 6 on the upstream side, is discharged to a main muffler and the like via an exhaust pipe 8 on the downstream side, and is further discharged outside. The so-called Helmholtz resonator formed by the resonance chamber 2 and the resonance pipe 12 reduces exhaust noise at a specific frequency.

The frequency of the reduced exhaust noise is calculated by the above-described Helmholtz equation. If the length of the resonance pipe 12 is increased, the frequency of the reduced exhaust noise is reduced, and the rotation of the internal combustion engine is reduced. 1 when the number is less than 2000rpm
The next muffled sound can be reduced. At that time, the resonance room 2
Even if the length of the resonance pipe 12 is increased, the exhaust noise of low frequency can be reduced even if the length of the resonance pipe 12 is increased without increasing the volume. That is, the passage pipe 4 is separated from the resonance pipe 12 and the exhaust pipe 14 by the partition plate 10, and the resonance pipe 12 is connected to the exhaust pipe 14.
Therefore, even if the resonance pipe 12 is lengthened, it does not increase in size.

The partition plate 10 is not limited to the case described above.
As shown in FIG. 3, the upstream partition plate 10 is connected to the resonance line 12.
Side, the resonance pipe 12 is closed, a through hole 17 is formed in the partition plate 10, and one end of the resonance pipe 12 is connected to the exhaust pipe 14.
It is good also as a structure made to be opened.

Next, a second embodiment different from the above-described first embodiment will be described.
The muffler for an internal combustion engine according to the embodiment will be described with reference to FIGS. Reference numeral 21 denotes a muffler main body of a sub-muffler, in which a resonance chamber 22 is formed. A double pipe 24 is connected to the muffler main body 21, and the double pipe 24 includes an inner pipe 26 and an outer pipe 28 into which the inner pipe 26 is inserted and which has a larger diameter than the inner pipe 26. One end of the outer tube 28 has the resonance chamber 22.
The plug member 30 is inserted and closed at one end of the outer tube 28 in the resonance chamber 22. Inner tube 26
Penetrates the plug member 30, further penetrates the resonance chamber 22,
It extends outside the muffler body 21.

Outer tube 2 extended outside muffler body 21
The other end of 8 is reduced in diameter so as to contact the outer periphery of the inner tube 26, and the other end of the outer tube 28 is also closed. In the second embodiment, the exhaust pipe 32 is formed by the inner pipe 26 and the inner pipe 2
Both ends of 6 are connected to an exhaust pipe (not shown), respectively, and are interposed in an exhaust passage. A resonance pipe 34 is formed between the inner pipe 26 and the outer pipe 28.

The outer tube 28 in the resonance chamber 22 is provided with a through hole 36 in the outer periphery thereof, whereby the resonance pipe 3
One end of 4 is open to the resonance chamber 22. The other end of the resonance pipe 34 is provided with a through-hole 3 formed in the outer circumference of the inner pipe 26.
8, an opening is provided in the exhaust pipe 32.

Also in the case of the second embodiment, the exhaust gas is exhausted through the exhaust pipe 32, and is connected to the resonance pipe 34 and the resonance chamber 2.
The noise of the specific frequency is reduced by the action of the Helmholtz resonator according to 2 above. Exhaust line 32 and resonance line 34
Are formed in a double tubular shape, so that even if the length of the resonance pipe 34 is increased, the size of the resonance pipe 34 is not increased, and even if the resonance pipe 34 is small, low-frequency exhaust noise can be reduced.

Next, a muffler for an internal combustion engine according to a third embodiment will be described with reference to FIG. Reference numeral 41 denotes a muffler main body of a sub-muffler, in which a resonance chamber 42 is formed. An inner pipe 44 penetrating through the resonance chamber 42 of the muffler main body 41 is provided, and exhaust pipes (not shown) are connected to both ends of the inner pipe 44 and are interposed in the exhaust flow path.

The inner tube 44 in the resonance chamber 42 is provided with an outer tube 46 having a larger diameter than the inner tube 44 so as to cover the inner tube 44 in a double tube shape. Both ends of the outer tube 46 are connected to the inner tube 4 respectively.
The diameter is reduced so as to be in contact with the outer periphery of the fourth member 4 and both ends thereof are closed. As shown in FIG. 7, the outer tube 46 is pressed so that both side surfaces thereof come into contact with the outer periphery of the inner tube 44.

A resonance pipe 48 is formed between the inner pipe 44 and the outer pipe 46, and an exhaust pipe 50 is formed by the inner pipe 44.
Are formed. A through hole 52 is formed in the outer circumference of one end of the outer tube 46, and one end of the resonance pipe 48 is connected to the resonance chamber 42.
It is open to. Also, the inner tube 44 on the other end side of the outer tube 46
A through hole 54 is formed in the outer periphery of the exhaust pipe 50, and the other end of the resonance pipe 48 is opened to the exhaust pipe 50.

Also in the case of the third embodiment, the exhaust gas from the internal combustion engine is discharged through the exhaust pipe 50. The action of the Helmholtz resonator formed by the resonance pipe 48 and the resonance chamber 42 reduces the exhaust noise at a specific frequency. Since the outer tube 46 is provided in the muffler main body 41, it is small and can reduce low frequency exhaust noise.

Next, a muffler for an internal combustion engine according to a fourth embodiment will be described with reference to FIG. Reference numeral 61 denotes a muffler main body of a sub-muffler. The inside of the muffler main body 61 is partitioned into two resonance chambers 64 and 66 by a partition wall 62. The muffler body 6
1 and a passage pipe 68 penetrating the partition wall 62. An exhaust pipe 70 on the upstream side and an exhaust pipe 72 on the downstream side are connected to both ends of the passage pipe 68, respectively.

The passage tube 68 is provided with a partition plate 74 along its entire length in the axial direction. In addition, passage pipe 6
A partition 76 is provided at substantially the same position as the partition 62 in one of the passages partitioned by the partition 74 in the inside 8. Thus, the upstream and downstream exhaust pipes 70 and 72 are provided in the passage pipe 68.
Is formed, and an exhaust pipe 78 communicating with the partition wall 76 is formed.
, A resonance pipe 80 opening toward the exhaust pipe 70 on the upstream side and a resonance pipe 82 opening toward the exhaust pipe 72 on the downstream side are formed. Both resonance lines 8
In the outer periphery of the passage tube 68 at one end of the
86 is formed, and one end of each of the resonance pipes 80 and 82 is opened to the resonance chamber 64.

Also in the case of the fourth embodiment, the exhaust line 78
Exhaust gas is exhausted through. In addition, both resonance lines 8
Two Helmholtz resonators are formed by the resonance chambers 0, 82 and the two resonance chambers 64, 66, so that the exhaust noise at a specific frequency is reduced, the size is small, and the exhaust noise at a low frequency can be reduced. The length of both resonance pipes 80 and 82 and both resonance chambers 6
By making the capacities of 4,66 different, it is also possible to reduce the exhaust noise of two different specific frequencies.

Next, a muffler for an internal combustion engine according to a fifth embodiment will be described with reference to FIG. The same members as those in the first embodiment described above are denoted by the same reference numerals, and detailed description is omitted. Reference numeral 91 denotes a muffler main body of a sub-muffler, and the inside of the muffler main body 91 is partitioned by a partition wall 92.
However, a resonance chamber 96 is formed on the other side. The sound absorbing chamber 94 is filled with a sound absorbing material 98 such as glass wool. First
Unlike the embodiment, the passage pipe 4 in the sound absorbing chamber 94 is provided with a large number of small holes 100 communicating the exhaust pipe 14 and the sound absorbing chamber 94.

Also in the case of the fifth embodiment, the exhaust gas is exhausted through the exhaust pipe 14. By the action of the Helmholtz resonator formed by the resonance pipe 12 and the resonance chamber 96, the exhaust noise at a specific frequency is reduced. In addition, the sound absorbing chamber 94 reduces high frequency exhaust noise.

Next, a muffler for an internal combustion engine according to a sixth embodiment will be described with reference to FIG. The same members as those in the fifth embodiment described above are denoted by the same reference numerals, and detailed description thereof will be omitted. The passage pipe 4 in the muffler main body 91 is
2 to form a sound absorbing chamber 104. The sound absorbing chamber 104 is filled with a sound absorbing material 106. In this case, as in the fifth embodiment, low-frequency noise and high-frequency noise can be reduced.

Next, a muffler for an internal combustion engine according to a seventh embodiment will be described with reference to FIG. Reference numeral 111 denotes a muffler main body of a main muffler.
The first expansion chamber 116, the second expansion chamber 118, and the resonance chamber 120 are partitioned by 114. Exhaust pipe 1 upstream at one end
22 are connected, the first expansion chamber 116 and the second expansion chamber 118
, And the other end thereof reaches the resonance chamber 120.
Is provided.

An outlet pipe 126 having one end opened to the first expansion chamber 116 extends through the second expansion chamber 118 and the resonance chamber 120 to the outside of the muffler main body 111. Partition wall 11 that separates first expansion chamber 116 and second expansion chamber 118
A number of small holes 128 are formed in 2.

The inlet pipe 124 is partitioned by a partition plate 130 provided along the axial direction, and an exhaust pipe 132 is formed on one side and a resonance pipe 134 is formed on the other. The partition plate 130 is bent toward the exhaust pipe 132 on the side of the resonance 120 chamber to close the exhaust pipe 132, and the resonance pipe 134 is closed.
Are formed so as to open to the resonance chamber 120. Further, a large number of small holes 136 are formed in the inlet pipe 124 in the second expansion chamber 118 so that the exhaust pipe 132 is connected to the second expansion chamber 1.
18.

In the muffler for an internal combustion engine according to the seventh embodiment,
The exhaust gas discharged from the internal combustion engine is supplied to the exhaust pipe 122, the exhaust pipe 132, the small hole 136, the second expansion chamber 118, the small hole 1
28, discharged through the first expansion chamber 116 and the outlet pipe 126. Even in this case, low-frequency exhaust noise can be reduced despite its small size. In addition, the action of the Helmholtz resonator formed by the resonance pipe 134 and the resonance chamber 120 reduces exhaust noise at a specific frequency. The second expansion chamber 118 from the exhaust pipe 132 through the small hole 136.
At the time of flowing into the small hole 128 from the second expansion chamber 118.
When the air flows into the first expansion chamber 116 via the air outlet, the high frequency exhaust noise is reduced due to the expansion effect and the interference effect.

Next, a muffler for an internal combustion engine according to an eighth embodiment will be described with reference to FIG. Note that the same members as those in the above-described seventh embodiment are denoted by the same reference numerals, and detailed description is omitted. In the muffler body 111 of the main muffler,
The first expansion chamber 116, the second expansion chamber 118, and the resonance chamber 120 are formed by being partitioned by partition walls 112 and 114.
The inlet pipe 138 is provided with a partition plate 14 provided along the axial direction.
By 0, it is partitioned into an exhaust pipe 142 and a resonance pipe 144.

The inlet pipe 138 is connected to the muffler main body 111 from the resonance chamber 120 side, and the resonance pipe 144 is opened to the resonance chamber 120. Further, an inlet pipe 138 extends so that the exhaust pipe 142 penetrates through the resonance chamber 120 and the second expansion chamber 118 and opens to the first expansion chamber 116.

The outlet pipe 126 is connected to the muffler main body 111 from the first expansion chamber 116 side, and the outlet pipe 126 is formed so as to penetrate the first expansion chamber 116 and open to the second expansion chamber 118. ing. Further, a large number of small holes 128 are formed in the partition wall 114, and communicate the first expansion chamber 116 and the second expansion chamber 118.

According to the muffler for an internal combustion engine of the eighth embodiment, similarly to the seventh embodiment, the resonance pipe 144 and the resonance chamber 120 are provided.
The exhaust noise at a specific frequency is reduced by the action of the Helmholtz resonator formed by the above. Even in this case, low-frequency exhaust noise can be reduced despite its small size. From the exhaust pipe 142 to the first expansion chamber 116,
Further, when flowing into the second expansion chamber 118 from the first expansion chamber 116 through the small hole 128, the expansion effect and the interference effect cause
High frequency exhaust noise is reduced.

Next, a muffler for an internal combustion engine according to a ninth embodiment will be described with reference to FIG. Reference numeral 151 denotes a muffler main body.
54 and a resonance chamber 156. Muffler body 1
An inlet pipe 158 is connected to 51.
Is connected to the expansion chamber 154. Also, the outlet pipe 160
And the outer tube 162 are formed in a double tubular shape, and the muffler body 1
51.

An exhaust pipe 164 is formed in the outlet pipe 160, and a resonance pipe 166 is formed between the outlet pipe 160 and the outer pipe 162. The outlet pipe 160 is connected to the resonance chamber 156.
The partition 152 is opened to the expansion chamber 154. One end of the outer tube 162 is reduced in diameter and is brought into contact with the outer periphery of the outlet tube 160 to be closed. The other end of the outer tube 162 is open to the resonance chamber 156. One end of the resonance pipe 166 is opened to the exhaust pipe 164 by a through hole 168 formed in the outlet pipe 160.

Even in the case of the muffler for an internal combustion engine according to the ninth embodiment, the exhaust noise of a specific frequency is reduced by the action of the Helmholtz resonator formed by the resonance pipe 166 and the resonance chamber 156. Even in this case, low-frequency exhaust noise can be reduced despite its small size. Further, when flowing into the expansion chamber 154 from the inlet pipe 158, high frequency exhaust noise is reduced due to expansion effects and interference effects.

Next, a muffler for an internal combustion engine according to a tenth embodiment will be described with reference to FIG. Note that the same members as those in the ninth embodiment described above are denoted by the same reference numerals, and detailed description is omitted. The inside of the muffler body 151 is partitioned into a first expansion chamber 174, a second expansion chamber 176, and a resonance chamber 178 by a first partition 170 and a second partition 172. 1st partition 1
A plurality of small holes 180 are formed in 70 to communicate the first expansion chamber 174 and the second expansion chamber 176.

The inlet pipe 158 and the outlet pipe 160 are opened to the first expansion chamber 174, and are connected to the outlet pipe 1 in the second expansion chamber 176.
A plurality of through holes 182 are formed in 60. Also,
The outlet pipe 160 outside the muffler body 151 is connected to the sound absorbing pipe 18.
4 to form a sound absorbing chamber 186. The sound absorbing chamber 186 is filled with a sound absorbing material 188. A plurality of through holes 190 are formed in the outlet pipe 160 in the sound absorbing chamber 186. Thereby, high frequency exhaust noise is reduced.

Also in this case, as in the ninth embodiment, the action of the Helmholtz resonator formed by the resonance pipe 166 and the resonance chamber 178 reduces the exhaust noise at a specific frequency. Even in this case, low-frequency exhaust noise can be reduced despite its small size. Also, when flowing into the first expansion chamber 174 and the second expansion chamber 176 from the inlet pipe 158,
The high frequency exhaust noise is reduced by the expansion effect and the interference effect.

As described above, the present invention is not limited to such embodiments at all, and can be implemented in various modes without departing from the gist of the present invention.

[0047]

As described above, the muffler for an internal combustion engine according to the present invention extends the length of the resonance pipe along the exhaust pipe without increasing the volume of the resonance chamber. This produces an effect that low frequency exhaust noise can be reduced even in a small size.

[Brief description of the drawings]

FIG. 1 is a sectional view of a muffler for an internal combustion engine as a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a sectional view of a main part of another embodiment in which a resonance pipe is opened to an exhaust pipe.

FIG. 4 is a sectional view of a muffler for an internal combustion engine as a second embodiment.

FIG. 5 is a sectional view taken along the line BB of FIG. 4;

FIG. 6 is a sectional view of a muffler for an internal combustion engine as a third embodiment.

FIG. 7 is a sectional view taken along the line CC in FIG. 6;

FIG. 8 is a sectional view of a muffler for an internal combustion engine as a fourth embodiment.

FIG. 9 is a sectional view of a muffler for an internal combustion engine as a fifth embodiment.

FIG. 10 is a sectional view of a muffler for an internal combustion engine as a sixth embodiment.

FIG. 11 is a sectional view of a muffler for an internal combustion engine as a seventh embodiment.

FIG. 12 is a sectional view of an muffler for an internal combustion engine as an eighth embodiment.

FIG. 13 is a sectional view of a muffler for an internal combustion engine as a ninth embodiment.

FIG. 14 is a sectional view of a muffler for an internal combustion engine as a ninth embodiment.

FIG. 15 is an explanatory diagram showing an exhaust system of the internal combustion engine.

FIG. 16 is a sectional view of a conventional muffler for an internal combustion engine.

[Explanation of symbols]

1, 21, 41, 61, 111, 151 ... muffler body 2, 22, 42, 64, 96, 120, 156, 208
... Resonance chamber 4,68 ... Path tube 6,8,70,72,122,210 ... Exhaust tube 10,74,130,140 ... Partition plate 12,34,48,80,82,134,144,16
6 Resonance pipeline 14, 32, 50, 78, 132, 142, 164 Exhaust pipeline 16, 17, 36, 38, 52, 54, 84, 168
Through hole 24 Double pipe 26, 44 Inner pipe 28, 46, 162 Outer pipe 30 Plug member 62, 76, 92, 112, 114, 152 Partition wall 94, 104 Sound absorbing chamber 98, 106 Sound absorbing material 100, 128, 136 Small hole 102 Sound absorbing tube 116 First expansion chamber 118 Second expansion chamber 124, 138, 158 Inlet pipe 126, 160 Outlet pipe 154 Expansion chamber 200 Catalyst converter 202 Main muffler 204: Sub-muffler 212: Resonance tube

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) F01N 1/08 F01N 1/08 J 7/08 7/08 A F term (reference) 3G004 BA01 BA09 CA02 CA07 CA13 DA01 DA08 DA09 DA14

Claims (8)

[Claims] 1. A muffler for an internal combustion engine provided in an exhaust flow path of exhaust gas discharged from an internal combustion engine to reduce exhaust noise, comprising: a resonance pipe having one end opened to a resonance chamber formed in a muffler body. An exhaust pipe interposed in the exhaust flow path, the other end of the resonance pipe is opened to the exhaust pipe, and the resonance pipe is formed along the exhaust pipe. Muffler for internal combustion engines. 2. The muffler for an internal combustion engine according to claim 1, wherein the inside of the passage pipe is partitioned by a partition plate along the axial direction, one of which is the resonance pipe, and the other is the exhaust pipe. 3. An inner pipe and an outer pipe are arranged in a double tube, the inner pipe is used as an exhaust pipe, and a space between the outer pipe and the inner pipe is used as a resonance pipe. Item 7. A muffler for an internal combustion engine according to Item 1. 4. An exhaust pipe is formed by providing an inner pipe penetrating through the resonance chamber in the muffler main body, and an outer pipe covering the inner pipe in the resonance chamber is provided in the resonance chamber in a double tubular shape. The resonance pipe is formed between the inner pipe and the outer pipe, and a through hole communicating with the resonance chamber is provided at one end of the outer pipe, and the inner pipe at the other end of the outer pipe is formed in the inner pipe. The muffler for an internal combustion engine according to claim 1, wherein a through hole is formed. 5. A passage pipe penetrating through the resonance chamber in the muffler main body, and the passage pipe is partitioned by a partition plate along an axial direction to form the resonance pipe and the exhaust pipe. The resonance chamber is partitioned into two by a partition, and the resonance pipe is partitioned into two by a partition, and a through-hole communicating each of the resonance chambers and the resonance pipe is formed in the passage pipe. The muffler for an internal combustion engine according to claim 1, wherein 6. A partition wall for partitioning the inside of the muffler main body into the resonance chamber and the sound absorbing chamber, and a large number of small holes communicating the exhaust pipe line and the sound absorbing chamber are formed in the passage pipe. The muffler for an internal combustion engine according to claim 2, wherein 7. A sound absorbing chamber is formed in the muffler main body to cover the passage pipe, and a number of small holes communicating the sound absorbing chamber and the exhaust pipe are formed in the passage pipe. The muffler for an internal combustion engine according to claim 2, characterized in that: 8. A partition plate which connects an inlet pipe and an outlet pipe to the muffler main body, partitions the muffler main body into the resonance chamber and two expansion chambers, and provides the inlet pipe along an axial direction. Partitioning the resonance pipe and the exhaust pipe, connecting the resonance pipe to the resonance chamber, connecting the exhaust pipe to one of the expansion chambers, and connecting the outlet pipe to the other expansion chamber. The muffler for an internal combustion engine according to claim 1, wherein