Engine exhaust system silencer

Abstract

The invention relates to the technical field of silencing, and discloses an engine exhaust system silencer. The engine exhaust system silencer comprises a cylinder, a front end cover and a back end cover fixed on the cylinder, an intake guide pipe communicated with an intake port in the front end cover, and an exhaust guide pipe communicated with an exhaust port in the back end cover; the internal of the cylinder is divided into a resistance silencing cavity and a blockage silencing cavity by a separation plate; the exhaust guide pipe penetrates through the separation plate, and an intake port thereof is positioned in the resistance silencing cavity; the intake guide pipe is inserted in the exhaust guide pipe from the intake port of the exhaust guide pipe, and the intersecting length of the two pipes is 300-400 mm; the intake guide pipe and the exhaust guide pipe are coaxially arranged; and the single-edge interval is 4-5 mm. The engine exhaust system silencer has a silencing effect on noise of low, medium and high frequency sections of an engine, in particular, has an obvious silencing effect on low-frequency noise under common rotating speed of the engine, and facilitates improvement of NVH performance of the engine.

Description

technical field [0001] The invention relates to the technical field of noise reduction, in particular to a muffler for an engine exhaust system. Background technique [0002] The muffler is the main noise reduction component of the engine exhaust system. The frequency range of automobile exhaust noise is between 50Hz and 2000Hz. The function of the muffler is to reduce noise in this frequency range. [0003] A muffler is a device that allows airflow to pass through and attenuates noise. According to the principle of noise reduction, it can be divided into resistive mufflers, resistive mufflers and impedance composite mufflers. Resistive mufflers are sound energy absorbed by sound-absorbing materials and converted into heat energy. In order to achieve the purpose of noise reduction, it is mainly used to eliminate high-frequency noise, and its representative structure is shown in the structure of the muffler disclosed in the patent literature of Chinese Patent Publication No. ...

AI Technical Summary

Problems solved by technology

Through the simulation analysis of the transmission loss of the muffler, it can be seen that the muffler has a good effect above 600Hz, but the transmission loss gradually decreases as the frequency decreases below 600Hz, and the transmission loss is below 4dB below 100Hz, which has almost no noise reduction ability.

For the 2000rpm common speed of the four-cylinder engine, the noise frequency corresponding to 67Hz, the use of this kind of muffler is likely to generate a large resonance noise near this frequency, which will affect the NVH performance of the vehicle

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