JPH0441911A - Exhaust device for engine - Google Patents

Abstract

PURPOSE:To facilitate the tuning for reducing booming noise by communicating a closed tail pipe having a cover in the middle to the resonator chamber of a muffler partitioned into expansion chambers and the resonator chamber inside, and changing the position of the cover. CONSTITUTION:Partition plates 8, 9 are provided in a muffler 5 to partition it into a resonator chamber 10 and two expansion chambers 11, 12, and the resonator chamber 10 and the expansion chamber 11 are communicated by a pipe 13 provided on the partition plate 8. The expansion chambers 11, 12 are communicated by a pipe 14 provided on the partition plate 9. An exhaust pipe 2 connected to an engine at one end is opened to the expansion chamber 11 across the expansion chamber 12, and one of two tail pipes 6 is opened to the expansion chamber 12 across the resonator chamber 10 and the expansion chamber 11. A cover 15 is fitted in the middle of the other tail pipe 7, the tail pipe 7 is opened to the resonator chamber 10, thus the portion from the opening section to the cover 15 functions as the extension section of the resonator chamber 10.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an exhaust system for an engine used in an automobile.

(Prior Art) As shown in FIGS. 3 and 4, an exhaust pipe 2 is provided under the floor of a car body 1, and exhaust gas from an engine 3 is passed from a catalytic converter 4 to a muffler 5 into the atmosphere. It should be drained. A tail vibro 7 is attached to the rear end of the muffler 5. Note that the shaded areas in these figures indicate that a heat shield plate has been installed, and the muffler 5
Even if the engine has multiple cylinders, there is only one, and this can provide sufficient noise reduction, but the tailpipe is sufficient to prevent back pressure from increasing and reducing exhaust efficiency. It is necessary to have an opening area. For this purpose, one tailpipe is sufficient if the tailpipe has a certain diameter, but due to appearance requirements, especially in sporty cars, two tailpipes are required. There are many.

FIG. 5 shows two tail vibros 7 provided at the rear of the muffler 5, and FIG. 6 shows its internal structure. A partition plate 8.9 is installed inside the muffler 5.
is provided, and is divided into three chambers, a resonator chamber 10 and an expansion chamber I1.12, by this partition plate 8.9. A pipe 13 is attached to the partition plate 8 to communicate between the 5 resonator chamber In and the expansion chamber 11. Further, a pipe 14 is attached to the partition plate 9, and an exhaust pipe 2 whose one end (not shown) is connected to the engine extends between the expansion chambers 12 and opens into the expansion chamber 11. The tail vibro 7 opens into the expansion chamber 12 across the resonator chamber lO and the expansion chamber opening.

(Problem to be Solved by the Invention) In the muffler 5 having such a structure, the exhaust gas entering the expansion chamber 11 from the exhaust pipe 2 is expanded here, and then enters the expansion chamber 12 from the vibrator 14 and expanded again. And expansion room +
2 to 2 tail vibro, going into 7. The exhaust gases are muffled by this expansion.

The size of the muffler 5 is determined depending on the characteristics of the engine, but in some cases, "muffled noise" may not be removed. Therefore, a resonator chamber (resonance chamber) 10 is provided to eliminate this "muffled sound". Jitsugyo 6
The inventions disclosed in Japanese Patent Nos. 3 to 21685 also relate to this technique.

Providing a resonator chamber will effectively suppress "muffled noise," but the resonator chamber
If 0 is provided, the external dimensions of the muffler 5 will increase, and the volume of the muffler body will become smaller. Further, in order to finely adjust the resonance frequency, it is necessary to change the volume of the resonator chamber 10. However, since the device described in this publication does not have an adjustment mechanism, it is not possible to change the volume of the resonator chamber.

The present invention has been made in view of this point, and makes it possible to change the volume of the resonator chamber to enable tuning over a wide range, while also maintaining the same external appearance as the conventional one. The present invention provides an exhaust system for an engine.

(Means for Solving the Problems) The present invention provides a first method for solving the problems described above.
As shown in Figures and Figure 2, the interior is partitioned into an expansion chamber N.
, +2 and one of the two tail vibros is connected to the expansion chamber 12 of the muffler 5 formed in the resonator chamber lO.
The other tail vibe 7 in this book is closed by providing a lid 15 in the middle, and the part on the side of the remuffler 5 from this [15] is configured to communicate with the resonator chamber IO.

(Function) With the above configuration, the exhaust gas that has entered the interior of the muffler 5 enters the resonator chamber IO from the vibrator 13 in the process of being muffled by expansion and being discharged from the tail vibro. The resonance effect that takes place here lowers the exhaust level of exhaust noise. The exhaust gas is then exhausted to the outside through the tail vibro.

By changing the position of i15 in the tail vibrator 7, tuning to reduce the muffled sound J can be easily performed.

(Example) Next, an example of the present invention will be described with reference to FIG. A partition plate 8.9 is provided inside the muffler 5, and the partition plate 8.9 divides the muffler 5 into an expansion chamber resonator chamber 10 and two expansion chambers 11.12. A vibrator 13 is attached to the partition plate 8, which communicates between the resonator chamber l opening and the expansion chamber 11, and the partition plate 9 connects the expansion chamber 1.
1. The exhaust pipe 2, whose one end (not shown) is connected to the engine, communicates between the expansion chamber 12 and the expansion chamber 1.
1, and one of the two tail vibros straddles the resonator chamber 10 and the expansion chamber 11 and opens into the expansion chamber 12.

A lid 15 is attached to the middle (near the tip) of the other one of the two tail vibrators 7 to close off the tail vibrator 7 from the inside. Since this tail vibe 7 opens into the resonator chamber 10, the area from this opening to i15 is formed as an extension of the resonator chamber 10.

In the muffler 5 having such a structure, the exhaust pipe 2 enters the expansion chamber 11 and is expanded, and the vibrator 11 enters the expansion chamber! 2
and expand again here. Thereafter, it enters the tail vibro opened into the expansion chamber 12 from the expansion chamber 12 and is discharged into the atmosphere.

The portion of the tail vibe 7 that communicates with the resonator chamber 1o does not enter the exhaust gas flow path together with the resonator chamber 1O, but resonates with the exhaust pressure in the expansion chamber 11, reducing the exhaust level of exhaust sound.

The material of the lid 15 must be sufficiently resistant to the temperature of the exhaust gas, and it is preferable that the lid 15 has a mounting structure that allows its position to be adjusted inside the tail vibe 7. Specifically, it is conceivable to screw a metal plate or ceramic plate into the tail vibe 7 while taking measures to prevent it from loosening.
A part of the tail vibe 7 is manufactured as a unit,
This may be connected in the middle of the tail vibrator 7. By using such a unit and changing the position of M15, it becomes easy to adjust the frequency characteristics as a resonator. FIG. 2 shows that when the position of iF+5 is changed in this way, the peak fllI of the 5 resonance frequency decreases as shown by the broken line in the range indicated by symbol A in the figure.

(Effects of the Invention) As explained above, the present invention connects one of the two tail vibes to the expansion chamber of the muffler, which is internally partitioned to form an expansion chamber and a resonator chamber, and One tail vibrator has a structure in which a lid is provided in the middle to close it off, and the part on the muffler side from the face communicates with the resonator chamber, so it has a simpler structure than the one described in the above-mentioned publication. With this, it is possible to obtain the necessary and sufficient resonator effect. Since there is no need to increase the external dimensions of the muffler, there will be no problems with mounting it to the vehicle body, and the interior dimensions will not be narrowed.The volume of the resonator chamber can be changed, allowing tuning to reduce the level of "muffled noise" etc. becomes easier. Since two tail vibes are attached to the muffler, the appearance remains unchanged from the conventional one.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a one-day embodiment of the present invention, Fig. 2 is a graph showing the characteristics when the position of the lid of Fig. 1 is changed, and Fig. 3 is a graph showing the characteristics when the position of the lid is changed.
Figure 4 is a bottom view of the car, Figure 4 is a side view showing the main parts of Figure 3. Figure 5 is a perspective view showing the area around the muffler, Figure 6 is a side view showing the main parts of the car.
The figure is a sectional view taken along the line A-A of the conventional structure shown in FIG. 2... Exhaust pipe 5... Muffler 6.7 - Tail vibe 8.9... Partition plate 10... Resonator chamber 1.12... Expansion chamber 13, 14... Vibe + 5 ・... Lid Figure 1 Patent Applicant: Suzuki Automobile Industry Co., Ltd. Concave Handshake (F!PH) Figure 3 Procedure Name Book ■, Case Indication 1990 Patent Application No. 145869 2, Name of Invention Engine Exhaust system 3, relationship with the person making the amendment Patent applicant name (208) Suzuki Motor Co., Ltd. 4, agent address 1-6 Kanda Surugadai, Chiyoda-ku, Tokyo Ochanomizu Square B Building 5 Figure 6 Figure 7 , Contents of the amendment (11 Specification, page 5, line 18: ``The partition plate 9 is the expansion chamber 1
1 and 12 are communicated with each other," is corrected to read, "The vibrator 14 of the partition plate 9 communicates between the expansion chambers 11 and 12." (2) On page 6, line 11 of the specification, ``Vibe IJ to J'' is corrected to ``Vibe 14''. (3) Figures 3 and 4 in the drawings are corrected to the attached ones.

Claims (1)

[Claims] (1) Connect one of the two tail pipes to the expansion chamber of the muffler, which has been partitioned into an expansion chamber and a resonator chamber, and insert a lid in the middle of the other tail pipe. What is claimed is: 1. An exhaust system for an engine, characterized in that the lid is closed, and a portion closer to the muffler than the lid communicates with the resonator chamber.