Internal combustion engine silencer

Abstract

A muffler for internal combustion engines, in order to achieve a high attenuating effect without reducing the attenuating effect in the high revolution range of the engine, comprising one or more expanding chambers 11 through 13 formed in a muffler 1, an inlet pipe 5 which opens into a expanding chamber 11 and introduces exhaust gas into the muffler 1, and an outlet pipe 6 which opens into other expanding chamber 13 and introduces exhaust gas out of the muffler 1. In the muffler, the exhaust gas discharged through an aperture 5a of this inlet pipe 5 is inverted once or more times in the muffler 1 and is introduced into an aperture 6a of the outlet pipe 6. In a contraflow area L2 in which the flowing direction C of exhaust gas flowing in the expanding chambers 11 through 13 and the flowing direction E of exhaust gas flowing in the outlet pipe 6 are not the same, interference holes 7 composing of a plurality of small holes communicating with the expanding chambers 11 through 13 are bored in the outlet pipe 6. The aperture area of the small holes 7 is kept at not less than 1% but not more than 5% of the surface area of the outlet pipe in the contraflow area L2.

Description

TECHNICAL FIELD [0001] The present invention relates to an international combustion engine silencer, or a muffler for internal combustion engines. BACKGROUND ART [0002] Among mufflers to be disposed on the exhaust line of an internal combustion engine are conventionally known ones having a U-turn structure in which exhaust gas is inverted once or more in the muffler. As a muffler having such a U-turn structure, the muffler illustrated in FIG. 11, for instance, is disclosed in the Japanese Utility Model Unexamined Publication JP-U-61-194718. [0003] The muffler, as shown in FIG. 11, is provided within its housing 101, successively from the upstream side (left side in the drawing) onward, a first expanding chamber 102, a second expanding chamber 103, a third expanding chamber 104 and a resonator chamber 105 partitioned from one another. In the third expanding chamber 104 opens an inlet pipe 106 for introducing exhaust gas into the muffler, and the first expanding chamber 102 is provide...

AI Technical Summary

Benefits of technology

[0005] The present invention, therefore, is intended to provide a muffler capable of achieving a high attenuating effect without reducing the attenuating effect in the high revolution range of the engine.

[0016] This configuration proves effective in attenuating noise in the low revolution area by virtue of its bypass holes.

[0018] With this configuration, an even greater attenuating effect can be achieved without reducing the attenuating effect in the high revolution range of the engine by boring the interference holes in the inlet pipe.

Problems solved by technology

With this configuration, exhaust noise flowing in the expanding chamber in one direction flows into the outlet pipe through the interference holes bored in the outlet pipe, interferes with exhaust noise flowing in the outlet pipe in the direction reverse to the flowing direction in the expanding chamber, and is attenuated by that interfering action.

Images