JP3748316B2 - Automotive exhaust muffler - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is applied to a sub-muffler that is mounted in order to supplement the muffled volume of a main muffler or improve the resonance characteristics of an exhaust muffler system, and belongs to the technical field of an automobile exhaust muffler having a muffler inner chamber as a resonator chamber. .
[0002]
[Prior art]
Conventionally, as sub-mufflers having a muffler inner chamber as a resonator chamber, those shown in Japanese Utility Model Laid-Open Nos. 59-526 and 61-142114 are known.
[0003]
As shown in FIG. 5, the sub-muffler described in Japanese Utility Model Publication No. 59-526 has a structure in which a resonator pipe is fixed to the muffler pipe by welding. As shown in Fig. 4, the large-diameter pipe acting as a resonator pipe concentrically with the muffler pipe is fixed.
[0004]
[Problems to be solved by the invention]
However, in the conventional sub-muffler in which the inner chamber of the muffler is a resonator chamber, the muffler pipe and the resonator pipe are configured by different parts, so that there is a problem that the number of parts increases.
[0005]
In addition, the muffler pipe and the resonator pipe are integrally fixed by welding, but high welding strength is required to maintain the fixing of the resonator pipe even during operation receiving high heat and vibration. If the welding of the resonator pipe is incomplete, it will not be possible to secure the silencing action by a stable resonator, and if the resonator pipe falls off, the resonator action will not be demonstrated and a high noise will be generated due to the impact sound. .
[0006]
Further, in the sub-muffler described in Japanese Utility Model Publication No. 59-526, the resonator pipe weld fixing portion of the muffler pipe protrudes toward the exhaust passage, so that the exhaust resistance increases and abnormal noise such as airflow noise is generated. End up.
[0007]
An object of the present invention is to provide an automobile exhaust muffler that achieves a combination of suppressing an increase in exhaust resistance, ease of welding, and reducing the number of parts.
[0008]
[Means for Solving the Problems]
(Solution 1)
The invention according to claim 1, which solves the above problem, is a cylindrical shell;
End plates provided at both ends of the cylindrical shell;
A muffler pipe provided through the center of the two end plates;
In an automobile exhaust muffler comprising the muffler pipe and a resonator pipe communicating with a resonator chamber inside the muffler,
The muffler pipe is formed by presetting plate overlapping portions that overlap each other in the circumferential direction when roll forming one plate material,
A resonator pipe extending in the axial direction is integrally formed by an inner plate portion and an outer plate portion of the plate overlap portion of the muffler pipe,
The resonator pipe has a muffler pipe communication hole and a resonator chamber communication hole formed at both ends thereof.
[0009]
(Solution 2)
The invention according to claim 2 for solving the above-described problem is the exhaust muffler for an automobile according to claim 1,
By forming an axial groove on the inner plate part of the plate overlapping portion, and covering the axial groove with an outer plate part, a resonator pipe is obtained,
A muffler pipe communication hole is created by opening a notch previously inserted in the circumferential direction with respect to the inner plate part by embossing, and the hole formed in the outer plate part at a position corresponding to the closed end of the axial recess is connected to the resonator chamber. It is characterized by a hole.
[0010]
(Solution 3)
The invention according to claim 3 for solving the above-mentioned problem is the exhaust muffler for an automobile according to claim 1,
An axial ridge is formed on the outer plate portion of the plate overlapping portion, and a resonator pipe is formed by covering the axial ridge with the inner plate portion,
Opening in the circumferential direction to the outer plate in advance by embossing makes a resonator chamber communication hole, and the hole opened in the inner plate at the position corresponding to the closed end of the axial ridge is connected to the muffler pipe It is characterized by a hole.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
First, the configuration will be described.
[0012]
The first embodiment corresponds to the first and second aspects of the invention.
[0013]
FIG. 1 is an overall sectional view showing an automobile exhaust muffler according to the first embodiment, and FIG. 2 is a view showing a resonator pipe integrated muffler pipe of the automobile exhaust muffler according to the first embodiment.
[0014]
In FIG. 1, M is an exhaust muffler for an automobile of the first embodiment, 1 is a cylindrical shell, 2 is a front end plate, 3 is a rear end plate, 4 is a muffler pipe, 5 is a resonator pipe, 6 is a resonator chamber, and 7 is a muffler pipe. A communication hole 8 is a resonator chamber communication hole.
[0015]
The cylindrical shell 1 has a shape such as a cylinder, an elliptic cylinder, or a long cylinder according to a vehicle type to which a muffler is applied.
[0016]
The front end plate 2 and the rear end plate 3 are provided at both ends of the cylindrical shell 1.
[0017]
The muffler pipe 4 is provided so as to penetrate through the central portions of the two end plates 2 and 3.
[0018]
The resonator pipe 5 is a pipe that connects the muffler pipe 4 and the resonator chamber 6 inside the muffler, and a muffler pipe communication hole 7 that communicates with the muffler pipe 4 and a resonator chamber communication hole 8 that communicates with the resonator chamber 6 are opened at both ends. It is holed.
[0019]
The configuration of the resonator pipe-integrated muffler pipe will be described with reference to FIG.
[0020]
The muffler pipe 4 is formed by setting in advance a plate overlapping portion 9 that overlaps each other in the circumferential direction when a single plate material is roll-formed, and the inner plate portion 9a and the outer side of the plate overlapping portion 9 of the muffler pipe 4 are formed. The resonator pipe 5 extending in the axial direction is integrally formed by the plate portion 9b. That is, the axial recess 9c is formed on the inner plate portion 9a of the plate overlapping portion 9 by embossing, and the axial recess 9c is covered with the outer plate portion 9b to form the resonator pipe 5.
[0021]
Then, a muffler pipe communication hole 7 is formed by opening a notch previously inserted in the circumferential direction with respect to the inner plate portion 9a by embossing, and is formed on the outer plate portion 9b at a position corresponding to the closed end portion 9d of the axial recess 9c. The opened hole is a resonator chamber communication hole 8.
[0022]
Next, the operation will be described.
[0023]
[Manufacture of muffler pipe with integrated resonator pipe]
An example of manufacturing a muffler pipe will be described. One plate material is prepared. First, a cut is made in the circumferential direction at a position corresponding to the muffler pipe communication hole 7 of the inner plate portion 9a of the plate overlapping portion 9, and the outer plate portion 9b is cut. A hole to be the resonator chamber communication hole 8 is opened.
[0024]
Next, an axial recess 9c is formed by embossing the inner plate portion 9a of the plate overlapping portion 9 in an axial direction while opening a notch on one end side and a closed end portion 9d on the other end side.
[0025]
Next, a single plate material that has been pre-processed is roll-formed to obtain a pipe diameter at which plate overlapping portions 9 that overlap each other in the circumferential direction are formed.
[0026]
Next, the end portion of the inner plate portion 9a is welded to the outer plate portion 9b, and the end portion of the outer plate portion 9b is welded to the inner plate portion 9a, whereby the muffler pipe 4 integrally including the resonator pipe 5 is manufactured. .
[0027]
[Silent action]
The exhaust gas from the engine flows through the muffler pipe 4 as shown by the arrows in FIG. 1 and a part of the exhaust gas is introduced into the resonator pipe 5 from the muffler pipe communication hole 7, and the resonator chamber through the resonator chamber communication hole 8. The exhaust noise in the resonance frequency range determined by the length of the resonator pipe 5 and the volume of the resonator chamber 6 is reduced by the resonance action.
[0028]
Next, the effect will be described.
[0029]
(1) The muffler pipe 4 is formed by setting in advance a plate overlapping portion 9 that overlaps each other in the circumferential direction when one plate material is roll-formed, and the inner plate portion 9a of the plate overlapping portion 9 of the muffler pipe 4 Since the resonator pipe 5 extending in the axial direction is integrally formed by the outer plate portion 9b, and the muffler pipe communication hole 7 and the resonator chamber communication hole 8 are opened at both ends of the resonator pipe 5, an increase in exhaust resistance is suppressed. Further, it is possible to provide an automobile exhaust muffler M that achieves both ease of welding and reduction in the number of parts.
[0030]
That is, an increase in exhaust resistance is suppressed by arranging the muffler pipe 4 and the resonator pipe 5 in parallel along the flow of the exhaust gas.
[0031]
Further, since the muffler pipe 4 and the resonator pipe 5 are integrated, for example, even if the welding is somewhat incomplete, a stable silencing action can be secured by a resonator as long as no gap is formed. The resonator pipe 5 does not fall off even if the distance is completely separated, and high welding strength is not required.
[0032]
Further, the muffler pipe 4 and the resonator pipe 5 are configured by only one part number, and the number of parts is reduced as compared with the conventional muffler having the number of parts of 2.
[0033]
(2) An axial recess 9c is formed in the inner plate portion 9a of the plate overlapping portion 9, and the axial recess 9c is covered with the outer plate portion 9b to form the resonator pipe 5, and in advance around the inner plate portion 9a. The cut in the direction is opened by embossing to form a muffler pipe communication hole 7. The hole formed in the outer plate portion 9 b at a position corresponding to the closed end portion 9 d of the axial recess 9 c is connected to the resonator chamber communication hole 8. Therefore, the muffler pipe communication hole 7 is arranged orthogonal to the flow of the exhaust gas, and the dynamic pressure of the exhaust gas is effectively introduced into the resonator chamber 6 via the resonator pipe 5, so that a high resonator effect can be exhibited. .
[0034]
(Embodiment 2)
First, the configuration will be described.
[0035]
The second embodiment corresponds to the first and third aspects of the invention.
[0036]
3 is an overall cross-sectional view showing the automobile exhaust muffler according to the second embodiment, and FIG. 4 is a view showing a resonator pipe integrated muffler pipe of the automobile exhaust muffler according to the second embodiment.
[0037]
In FIG. 3, M ′ is an automobile exhaust muffler according to the second embodiment, 1 is a cylindrical shell, 2 is a front end plate, 3 is a rear end plate, 4 is a muffler pipe, 5 is a resonator pipe, 6 is a resonator chamber, and 7 is A muffler pipe communication hole 8 is a resonator chamber communication hole.
[0038]
The configuration of the resonator pipe-integrated muffler pipe will be described with reference to FIG.
[0039]
The muffler pipe 4 is formed by setting in advance a plate overlapping portion 9 that overlaps each other in the circumferential direction when a single plate material is roll-formed, and the inner plate portion 9a and the outer side of the plate overlapping portion 9 of the muffler pipe 4 are formed. The resonator pipe 5 extending in the axial direction is integrally formed by the plate portion 9b. That is, the axial ridge 9e is formed on the outer plate portion 9b of the plate overlapping portion 9 by embossing, and the axial ridge 9e is covered with the inner plate portion 9a to form the resonator pipe 5.
[0040]
Then, the resonator chamber communication hole 8 is formed by opening a notch that is previously made in the circumferential direction with respect to the outer plate portion 9b by embossing, and the inner plate portion 9a at a position corresponding to the closed end portion 9f of the axial ridge 9e. The muffler pipe communication hole 7 is formed in the hole.
[0041]
Therefore, in the automobile exhaust muffler of the second embodiment, the following effect is added to the effect of (1) of the first embodiment.
[0042]
(3) An axial ridge 9e is formed on the outer plate portion 9b of the plate overlapping portion 9, and the axial ridge 9e is covered with the inner plate portion 9a to form the resonator pipe 5, and in advance around the outer plate portion 9b. The cut in the direction is opened by embossing to form a resonator chamber communication hole 8, and the hole formed in the inner plate portion 9 a at a position corresponding to the closed end portion 9 f of the axial ridge 9 e is connected to the muffler pipe communication hole 7. Therefore, the cross-sectional shape of the exhaust passage of the muffler pipe 4 is kept substantially circular, and an increase in exhaust gas flow resistance due to the addition of the resonator pipe 5 can be minimized.
[0043]
(Other embodiments)
In the first and second embodiments, an example of an exhaust muffler in which one resonance chamber is set is shown, but the present invention can also be applied to an exhaust muffler in which two or more resonance chambers are set.
[0044]
In the first embodiment, an example is shown in which a resonator pipe is formed by forming an axial recess in the inner plate portion of the plate overlap portion of the muffler pipe. In the second embodiment, a shaft is formed on the outer plate portion of the plate overlap portion of the muffler pipe. An example of forming a resonator pipe by forming directional ridges was shown, but an axial ridge was formed on the inner plate portion of the plate overlap portion of the muffler pipe, an axial ridge was formed on the outer plate portion, and both A resonator pipe having a substantially circular cross section may be formed.
[0045]
【The invention's effect】
In the first aspect of the invention, the cylindrical shell, the end plates provided at both ends of the cylindrical shell, the muffler pipe provided through the central part of the two end plates, and the muffler pipe And an exhaust muffler for an automobile having a resonator pipe communicating with a resonator chamber inside the muffler, by previously setting plate overlapping portions that overlap each other in the circumferential direction when a single plate material is roll-formed. A resonator pipe extending in the axial direction is integrally formed by an inner plate portion and an outer plate portion of a plate overlap portion of the muffler pipe, and the resonator pipe has a muffler pipe communication hole and a resonator chamber communication hole at both ends thereof. Therefore, it is possible to reduce the number of parts by reducing the increase in exhaust resistance, ease of welding, and reducing the number of parts. It is possible to provide a muffler.
[0046]
In the invention according to claim 2, in the exhaust muffler for an automobile according to claim 1, an axial recess is formed in the inner plate portion of the plate overlapping portion, and the axial recess is covered with the outer plate portion. In the resonator pipe, a muffler pipe communicating hole was opened by embossing a notch previously inserted in the circumferential direction with respect to the inner plate portion, and was opened in the outer plate portion at a position corresponding to the closed end portion of the axial recess. Since the hole is a resonator chamber communication hole, in addition to the effect of the invention of claim 1, the muffler pipe communication hole is arranged perpendicular to the flow of the exhaust gas, so that the dynamic pressure of the exhaust gas is effectively transferred to the resonator chamber via the resonator pipe. By being introduced, a high resonator effect can be exhibited.
[0047]
According to a third aspect of the present invention, in the automobile exhaust muffler according to the first aspect, an axial ridge is formed on the outer plate portion of the plate overlapping portion, and the axial ridge is covered with the inner plate portion. Resonator pipes are formed in the circumferential direction with respect to the outer plate portion in advance by embossing to form a resonator chamber communication hole, which is opened in the inner plate portion at a position corresponding to the closed end of the axial ridge. In addition to the effect of the invention of claim 1, the exhaust passage cross-sectional shape of the muffler pipe is maintained in a substantially circular shape, and an increase in exhaust gas flow resistance due to the addition of the resonator pipe is minimized. be able to.
[Brief description of the drawings]
1 is an overall cross-sectional view showing an automobile exhaust muffler according to a first embodiment;
FIG. 2 is a diagram showing a muffler pipe integrated with a resonator pipe of an automobile exhaust muffler according to the first embodiment;
3 is an overall cross-sectional view showing an automobile exhaust muffler according to a second embodiment. FIG.
FIG. 4 is a diagram illustrating a muffler pipe integrated with a resonator pipe of an exhaust muffler for an automobile according to a second embodiment.
FIG. 5 is a cross-sectional view showing a first example of a conventional sub-muffler in which a muffler inner chamber is a resonator chamber.
FIG. 6 is a cross-sectional view showing a second example of a conventional sub-muffler in which the muffler inner chamber is a resonator chamber.
[Explanation of symbols]
M Exhaust Muffler for Automobile of Embodiment 1 M 'Exhaust Muffler for Automobile of Embodiment 2 Tubular Shell 2 Front End Plate 3 Rear End Plate 4 Muffler Pipe 5 Resonator Pipe 6 Resonator Chamber 7 Muffler Pipe Communication Hole 8 Resonator Chamber Communication Hole 9 Plate overlap portion 9a Inner plate portion 9b Outer plate portion 9c Axial recess 9d Closed end 9e Axial protrusion 9f Closed end

Claims (3)

A cylindrical shell (1);
End plates (2) and (3) provided at both ends of the cylindrical shell (1) and a muffler pipe (4 provided through the center of the two end plates (2) and (3) )When,
In an automobile exhaust muffler comprising the muffler pipe (4) and a resonator pipe (5) communicating with a resonator chamber inside the muffler,
The muffler pipe (4) is formed by presetting plate overlapping portions (9) that overlap each other in the circumferential direction when roll forming one plate material,
A resonator pipe (5) extending in the axial direction is integrally formed by the inner plate portion (9a) and the outer plate portion (9b) of the plate overlap portion (9) of the muffler pipe (4),
An exhaust muffler for an automobile, wherein a muffler pipe communication hole (7) and a resonator chamber communication hole (8) are opened at both ends of the resonator pipe (5). The exhaust muffler for an automobile according to claim 1,
An axial recess (9c) is formed in the inner plate portion (9a) of the plate overlapping portion (9), and the axial recess (9c) is covered with an outer plate portion (9b) to thereby form a resonator pipe (5). age,
A muffler pipe communication hole (7) is formed by opening an incision previously made in the circumferential direction with respect to the inner plate portion (9a) by embossing, and at a position corresponding to the closed end portion (9d) of the axial recess (9c). An exhaust muffler for an automobile characterized in that a hole formed in the outer plate portion (9b) is a resonator chamber communication hole (8). The exhaust muffler for an automobile according to claim 1,
An axial ridge (9e) is formed on the outer plate portion (9b) of the plate overlapping portion (9), and the axial ridge (9e) is covered with the inner plate portion (9a) to thereby form a resonator pipe (5). age,
A position that corresponds to the closed end (9f) of the axial ridge (9e) is formed by opening a cut in the circumferential direction with respect to the outer plate (9b) in advance by embossing to form a resonator chamber communication hole (8). The exhaust muffler for automobiles is characterized in that a hole formed in the inner plate portion (9a) of the motor is a muffler pipe communication hole (7).

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