| 摘要 |
<p>PURPOSE:To suitably cool the housing of an active muffler, which surrounds at least the sound outlet side of a sound wave outlet device. CONSTITUTION:An active muffler comprises a sound wave output device 5 located around the outlet of an exhaust pipe 3 of an internal combustion engine, a housing 40 surrounding the outlet of the exhaust pipe 3 and at least the sound wave outlet side of the sound wave output device 5 and having an opening separated away from the device 5 by a specified distance, and a residual sound detector 6 located around the opening so as to be exposed to the inside of the housing 40. Further, cooling fins 40f are formed in at least a part of the outer surface of the housing 40. Thus, exhaust sound from the exhaust pipe 30 interferes with sound waves having a reverse phase and issued from the device 5 so as to be suppressed.</p> |
