An exhaust muffler with automatic adjustment of magnetorheological damping

Abstract

The invention relates to the field of exhaust silencing equipment, particularly to an exhaust silencer capable of automatically regulating the magnetorheological damping. The exhaust silencer comprises a hollow barrel, an intake pipe and an escape pipe are arranged along the two ends of the barrel; the barrel comprises a casing, a felt and a perforated plate; the barrel is divided into a first cavity body, a second cavity body and a third cavity body in the direction perpendicular to the axis of the barrel by a left partition plate and a right partition plate, the intake pipe and the first cavity body communicate, and the escape pipe and the third cavity body communicate; the left partition plate is provided with a rotating shaft coaxial with the barrel, a sound absorption blade is installed on the rotating shaft extending into the first cavity body and is formed by adhering a piezoelectric crystal plate and a metal substrate, and a damping unit is arranged on the rotating shaft extending into the second cavity body. An air flow is blown to the sound absorption blade to transform the kinetic energy of the air flow to the mechanical energy, and the piezoelectric effect of the piezoelectric crystal plate is used to actively absorb sound. The exhaust silencer has the advantages and characteristics that: the kinetic energy of the air flow is transformed to the mechanical energy through the sound absorption blade, the sound absorption capability is strong, the absorption band is wide, the damping unit is supplied with power by utilizing the piezoelectric effect of the piezoelectric crystal plate, no external power supply is needed, and the cost is lowered.

Description

technical field [0001] The invention relates to the field of exhaust muffler equipment, in particular to an exhaust muffler for automatically adjusting magnetorheological damping. Background technique [0002] The exhaust muffler is a device that prevents sound transmission and allows airflow to pass through, and is an important measure to eliminate aerodynamic noise. Exhaust muffler is a noise reduction device installed in the exhaust system of aerodynamic equipment (such as blower, air compressor, boiler exhaust, generator, water pump and other equipment with high exhaust noise). There are many types of exhaust mufflers, which are developed according to the principle of anti-spray and resistance compound noise reduction, mainly including small hole injection and expansion sound absorption. [0003] In the prior art, the exhaust muffler effect of the exhaust muffler is not satisfactory because of the following reasons: 1. Since each hole has its own natural frequency in th...

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Problems solved by technology

[0003] In the prior art, the exhaust muffler effect of the exhaust muffler is not satisfactory because of the following reasons: 1. Since each hole has its own natural frequency in the method of muffler based on small hole injection, there are only certain frequencies near the natural frequency of the mesh. The sound wave of the frequency can only pass through the mesh, so the sound absorption coefficient is low, the absorption frequency band is narrow, and it is not easy to control; 2. The sound absorption method based on impedance matching has a good effect on low frequencies and poor high frequency effects

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