A magneto-rheological active sound-absorbing muffler for automobile engine exhaust system

Abstract

The invention relates to the field of exhaust silencing equipment, in particular to a magneto-rheological active sound absorption silencer for an automobile engine exhausting system. The magneto-rheological active sound absorption silencer comprises a hollow cylindrical barrel, an air inlet pipe and an air outlet pipe are arranged at two axial ends of the barrel, the barrel comprises a shell, glass cotton and a hole penetrating plate, a plurality of air holes are formed in the hole penetrating plate, the barrel is divided into a first cavity, a second cavity and a third cavity by a left pistonand a partition plate along the direction perpendicular to the axis of the barrel, a piston rod coaxial with the barrel is fixedly arranged on the left piston, a rainbow-type piezoelectric vibrator is arranged on a thin shaft of the piston rod extending into the first cavity in a sleeving manner, and a magnetorheological fluid damping unit is arranged on a piston rod extending into the second cavity. The silencer has the advantages that chamber volume and the size of damping force of a damping unit can be automatically adjusted according to change of rotating speed of an engine, so that dynamic automatic sound absorption is achieved by the aid of the piezoelectric ceramics, hole penetrating plates and glass cotton, and an absorption band is wide.

Description

technical field [0001] The invention relates to the field of exhaust muffler equipment, in particular to a magneto-rheological active sound-absorbing muffler used in an automobile engine exhaust system. Background technique [0002] With the improvement of the degree of industrialization, the degree of noise hazards is increasing day by day. Car noise has become the most important noise source in the current urban environmental noise, while exhaust noise is the main noise source of car engines. The exhaust muffler prevents sound transmission and allows airflow to pass through. A device is an important measure to eliminate aerodynamic noise. There are many types of exhaust mufflers, and the muffler performance of most exhaust mufflers depends on fixed structural parameters. In the prior art, the exhaust silencer effect of the exhaust muffler is not ideal, the reason is that: the exhaust noise of the engine changes with the speed of the engine, and the silencer frequency of t...

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Problems solved by technology

In the prior art, the exhaust silencer effect of the exhaust muffler is not ideal, the reason is that: the exhaust noise of the engine changes with the speed of the engine, and the silencer frequency of the exhaust muffler cannot be automatically adjusted with the change of the engine speed, so the sound absorption coefficient is low. The absorption frequency band is narrow and difficult to control

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