Active silencer

Abstract

The invention provides an active silencer, and belongs to the field of silencers. A baffle and a porous material layer are arranged in a shell, a rotating shaft is installed in the center of the baffle, and a plurality of airflow holes are formed in the baffle; the end of an output shaft of a motor is connected with a first belt wheel, and a second belt wheel is installed at the front end of the rotating shaft and is in transmission connection with the first belt wheel through a belt; the motor is electrically connected with a computer through a motor driver; a rigid wall is installed on the rear portion of the porous material layer, a first sound pressure sensor is installed in front of the baffle, a second sound pressure sensor is installed in front of the rigid wall, and the two sound pressure sensors are electrically connected with the computer; and a first through hole is formed in the side wall, between the porous material layer and the rigid wall, of the shell, and an electromagnetic valve is installed in the first through hole and electrically connected with the computer. According to the active silencer, under the condition that the noise frequency is continuously changed,a sound absorption coefficient of the silencer is kept at an optimal value all the time by collecting information and adjusting the structure, and the silencer is novel, unique and high in sound absorption efficiency.

Description

technical field [0001] The invention belongs to the technical field of mufflers, and in particular relates to an active muffler. Background technique [0002] In the field of sound absorption technology, the most widely used sound absorption technologies are the following three: sound absorption material sound absorption, perforated plate sound absorption, and impedance composite sound absorption. The sound absorption principle of the sound-absorbing material is: use the sound-absorbing performance of the sound-absorbing material itself to absorb the noise so as to achieve the sound-absorbing effect. The sound absorption principle of the perforated plate is: there are several small holes on the metal plate or wooden plate, and they are installed at a distance D in front of the rigid wall to form several parallel Helmholtz resonators. When the sound wave reaches the resonator, the gas in the small hole will reciprocate like a piston under the pressure of the sound wave. The...

AI Technical Summary

Problems solved by technology

[0003] The above three sound absorption technologies are all passive sound absorption, which cannot properly adjust the sound absorption performance according to the change of noise frequency during use

However, the exhaust noise frequency of the engine is constantly changing according to the operating conditions of the engine, so the above three mufflers cannot achieve a more ideal sound absorption effect

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