Noise attenuator and vehicle air intake duct provided therewith

Abstract

A noise attenuator which can reduce time and cost for installation thereof as compared with the conventional configuration and a vehicle air intake duct provided with the noise attenuator are provided. The noise attenuator includes a pair of circular through holes formed through a duct wall, a pair of wave transmitting/receiving membrane which are stretched so as to close the circular through holes, and a seesaw member which connects between central portions of the paired transmitting/receiving membranes. Accordingly, when one of the membranes receives a sound wave of noise thereby to be vibrated at a predetermined frequency, the other membrane follows it and is also vibrated while shifted by a half cycle. As a result, a cancellation wave with a phase opposite to the sound wave received by the one membrane is transmitted from the other membrane, whereupon the noise can be attenuated.

Dependencies are inferred from the claim text.