Patent ID: 6386317
Filing Date: 2002-05-14
Classification: F02M,F05C,F16L

Abstract:
A sound-absorbing duct structure for an intake system of an automotive internal combustion engine, comprising:a duct defining thereinside a gas passage, a part of said duct being formed with a plurality of small holes, said duct being connected to an air intake duct of an air cleaner so that the gas passage forms part of an air intake passage through which intake air is supplied to the engine; and a sound-absorbing section arranged in communication with the gas passage, through the small holes, including: a piezoelectric material exhibiting a piezoelectric effect, said piezoelectric material being adapted to generate electric charge upon application of sound pressure in the gas pressure, and an electrically conductive material in contact with said piezoelectric material and adapted to be supplied with the electric charge from said piezoelectric material so as to consume the electrical charge.