Exhaust muffler for vehicle

Abstract

An exhaust muffler for a vehicle includes a muffler body coupled to an exhaust pipe and a tailpipe coupled to the muffler body. The muffler body has a plurality of expansion chambers, an exit communication pipe that discharges exhaust to the tailpipe from one of the plurality of expansion chambers positioned in a most downstream part of an exhaust flow path, and a spark arrester arranged in the exit communication pipe. An exhaust flow path narrowing portion is provided at an entrance portion of the exit communication pipe.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to an exhaust muffler for a vehicle. In particular, the present invention relates to a spark arrester provided in an exhaust muffler for a vehicle.[0003]2. Description of the Related Art[0004]Conventionally, an exhaust muffler for a vehicle including a spark arrester is known. In general, the spark arrester is formed by a mesh-like member made of metal.[0005]Meanwhile, since the spark arrester is arranged in an exhaust flow path in the exhaust muffler and exposed to exhaust gas, it is required to be so durable that it does not deform under conditions of high temperatures and high back pressure with an exhaust pulse. Accordingly, the spark arrester is provided with a frame member for reinforcing a mesh-like member made of a metal mesh. Thus, the spark arrester is prevented from deforming under the foregoing conditions. There is Prior Technique Document JP 8-61046 A.[0006]That is, the spark a...

AI Technical Summary

Benefits of technology

[0009]With the structure described above, the spark arrester is not arranged in the expansion chamber but in the exit communication pipe. Further, the exhaust flow path narrowing portion is provided at the entrance portion of the exit communication pipe. Thus, the back pressure acting on the spark arrester can be reduced, whereby deformation due to back pressure of the spark arrester can be suppressed. As a result, the reinforce member can be dispensed with, and designing of the spark arrester can be streamlined.

[0012]With the structure (1), since the spark arrester is structured by a mesh-like member, the productivity of the spark arrester can be improved and costs can be reduced.

[0013]Furthermore, since no reinforce member covers the surface of the spark arrester, the filter portion of the spark arrester can be secured for the entire surface. As a result, the spark arrester can be structured in a compact manner.

[0015]With the structure (2), the exhaust flow path narrowing portion can be easily formed. Further, as compared with the case where a tapered narrowing portion is formed, the exhaust flow path can be sharply narrowed, and the back pressure in the exit communication pipe can be more effectively reduced. Thus, deformation caused by the back pressure of the spark arrester can be further suppressed.

[0017]With the structure (3), while realizing a reduction in the back pressure, it becomes possible to secure the exhaust flow path of proper size, and to avoid a reduction in the engine performance attributed to an excessive increase in the back pressure.

[0019]With the structure (4), it becomes possible to avoid an excessive increase in the diameter of the exit communication pipe, whereby the muffler body can be structured in a compact manner.

Problems solved by technology

Therefore, since the structure is complicated, manufacturing of the spark arrester is not easy and involves high costs.

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