JPH0573892B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention [Field of Industrial Application] The present invention relates to a muffler for internal combustion engines, particularly for motorcycles and passenger cars.

[Conventional technology]

This type of muffler is required to reduce the noise level and increase the output by reducing the back pressure to the engine.

Factors contributing to the above-mentioned output improvement are determined not only by the internal structure of the silencer but also by the pipe size. However, if the diameter of the pipe is increased, the layout of the pipes within the silencer becomes impossible.

[Problem that the invention seeks to solve]

Therefore, these pipes are divided into multiple small diameter pipes, but the exhaust inlet side of the exhaust pipe (joint pipe, tail pipe, etc.) generally penetrates the partition plate and protrudes into the expansion chamber. However, there is a problem in that the resistance to the exhaust gas flowing into the small-diameter pipe increases, making it difficult to achieve the intended purpose.

It is an object of the present invention to solve this problem and also to improve the silencing function.

B. Structure of the Invention [Means for Solving Problems] The present invention provides a silencer for an internal combustion engine having at least two or more exhaust pipes from one expansion chamber partitioned by a partition plate. The exhaust inlet of the exhaust pipe is located approximately on the same plane as the partition plate, and a common exhaust guide member having a substantially semicircular cross section is arranged in front of the exhaust inlet and is fixed to the partition plate, and the end face of the exhaust guide member is fixed to the partition plate. This is a muffler for an internal combustion engine in which the expansion chamber is opened to the expansion chamber.

[Effect]

The exhaust flow flowing along the partition plate surface enters the exhaust guide member and flows into the exhaust gas introduction ports of the plurality of exhaust pipes opening on the partition plate surface, so that the resistance to flow into the exhaust pipe is small.

In addition, the amount of exhaust DC waves passing through the exhaust pipe is reduced, and together with the interference effect, the noise reduction effect is improved.

〔Example〕

Figure 1 shows a container 1 divided into 3 chambers 4 to 6 by partition plates 2 and 3.
The exhaust gas is introduced into the first expansion chamber 4 from the introduction pipe 7, and is sequentially discharged into the second and third expansion chambers 5 and 6 through the connecting pipes 8 and 9, and then divided into two from the third expansion chamber 6. This is an example in which the present invention is applied to a muffler configured to discharge through tail pipes (discharge pipes) 10 and 11.

That is, the inlets 10a, 11 of the tail pipes 10, 11
a is located on the surface of the partition plate 2 that forms the expansion chamber 6 (the amount of protrusion from the partition plate 2 to the expansion chamber 6 is made approximately zero), and a common exhaust guide member is provided in front of the inlet ports 10a and 11a. 12 will be provided.

The guide member 12 has a substantially semicircular cross section as shown by the dotted line in FIG. It is formed along the partition plate surface and welded to the partition plate 2. Further, an opening 13 is provided in the longitudinal end face of the exhaust guide member 12 to serve as an exhaust introduction port. The opening 13 may be at one end or both ends, but it should be provided at both ends and from each end to the nearest inlet port 10a, 11a.
Interference silencing effect can be improved by making the distances different.

Since the exhaust gas discharged from the coupling pipe 9 into the third expansion chamber 6 basically flows along the chamber wall surface, the exhaust gas flowing along the surface of the partition plate 2 enters the semicircular groove of the guide member 12.
Tail pipe inlet 10a, 1 that opens on the partition plate surface
1a. That is, the opening 13 of the guide member 12,
Since it naturally flows into the two introduction ports, the introduction resistance can be minimized even if the pipes 10 and 11 are formed with small diameters. Its introduction ports 10a, 11
a. It is desirable that the opening 13 widens its entrance into a trumpet shape as shown in the first figure.

Figure 3 shows the second expansion chamber 15 and the third and fourth expansion chambers 1.
This is an example in which the present invention is applied to connection pipes (discharge pipes) 18 and 19 connected to pipes 6 and 17. Note that the structure of the silencer may be applied to various types other than those illustrated.

C. Effects of the Invention As described above, when the exhaust pipe such as the coupling pipe or tail pipe of a muffler is divided into small diameter pipes in order to reduce output loss due to exhaust back pressure, the present invention can be applied to The resistance to introducing the exhaust gas into the pipes is reduced to improve the output, and furthermore, the DC wave leakage from the exhaust pipes is avoided. Furthermore, the inlet opening 10 of the pipes 10 and 11 is connected to the inlet opening 13 of the exhaust guide member 12.
It has the effect of attenuating the sound pressure level due to interference based on the difference in distance to a and 11a.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a silencer according to an embodiment of the present invention applied to a tail pipe, Fig. 2 is a front view of the main parts thereof, and Fig. 3
The figure is a longitudinal sectional view of a silencer in which the present invention is applied to a coupling pipe. 1... Instrument barrel, 2, 3... Partition plate, 4, 5, 6...
...Expansion chamber, 10, 11...Tail pipe, 10a/11a
...Exhaust inlet, 12...Exhaust guide member, 13...
...Opening, 18, 19...Joining pipe.

Claims (1)

[Claims] 1. In a silencer for an internal combustion engine having at least two or more exhaust pipes from one expansion chamber partitioned by a partition plate, the exhaust inlets of the plurality of exhaust pipes are abbreviated as the partition plate. An internal combustion engine in which a common exhaust guide member having a substantially semicircular cross section is arranged on the same plane in front of the exhaust inlet and is fixed to a partition plate, and the end face of the exhaust guide member is opened into the expansion chamber. silencer. 2. The muffler for an internal combustion engine according to claim 1, wherein one or both ends of the exhaust guide member are opened to the expansion chamber. 3. The muffler for an internal combustion engine according to claim 1, wherein the outlet ports of the plurality of exhaust pipes are opened into the same chamber or into separate chambers.