Broadband active silencer for automobile

Abstract

A broadband active silencer for an automobile comprises a cylindrical shell. A piezoelectric material layer is coated on the inner wall of the cylindrical shell, a first polyvinylidene fluoride film is coated on the inner wall of the piezoelectric material layer, a rubber layer is coated on the inner surface of the first polyvinylidene fluoride film, a second polyvinylidene fluoride film is coated on the inner surface of the rubber layer, a porous material layer is coated on the inner side of the second polyvinylidene fluoride film, and the first polyvinylidene fluoride film and the second polyvinylidene fluoride film are connected with a controller through leads and dischargers. The two polyvinylidene fluoride films are used for detecting incident sound pressure and reflected sound pressure of the piezoelectric material layer, the controller is used for computing voltage needing to be loaded on piezoelectric materials, the piezoelectric materials can vibrate, the acoustic impedance of the surfaces of the piezoelectric materials is matched with that of air inside the silencer, and energy of noise inside the silencer is completely consumed by the piezoelectric materials, so that the purpose of active noise control is achieved.

Description

technical field [0001] The invention relates to vehicles, in particular to a vehicle vibration and noise control device, in particular to a wide-band active muffler for automobiles. Background technique [0002] The muffler is an effective structure to reduce vehicle engine noise. There are many types of it. According to its muffler mechanism, it can be divided into resistive muffler, resistive muffler and impedance composite muffler. The principle of muffler is to use the sound-absorbing material in the pipeline to partially absorb the sound energy propagating along the pipeline. Resistant mufflers use pipes of various shapes and sizes and perforated pipe resonance sound-absorbing structures, etc., to cause impedance mismatch of sound waves in the system, so that sound waves are reflected and lost back and forth in the pipes and resonant cavity, so as to achieve the purpose of noise reduction. Impedance composite muffler is a combination of resistive muffler and resistive ...

AI Technical Summary

Problems solved by technology

[0003] The object of the present invention is to provide a kind of broadband active muffler for automobile, said this kind of broadband active muffler for automobile should solve the problem that the muffler in the prior art is a passive muffler, which cannot be adjusted with the engine noise frequency, thus causing its Technical problems with poor noise reduction effect

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