SU1469193A1 - Silencer - Google Patents

Abstract

The invention relates to engine building and makes it possible to increase the efficiency of noise suppression of a silencer due to hydraulic losses of energy of resonant oscillations and their damping. The flow of gases, pressure in the housing 1, in the first chamber 7 expands and through the overflow pipe 8 installed in the partition 6 separating the first chamber 7 from the next upstream chamber 7 enters the latter. At least one tube 8 is provided with openings 9, made in one transverse plane and arranged according to a predetermined relationship, due to which, and given that the antinodes of sound pressure for certain resonant oscillations are established in the middle of tube 8, the medium in the openings 9 of tube 8 makes an intense oscillatory motion from the tube 8 into the chamber 7 and back. Due to the hydraulic losses, the energy of the resonant oscillations is reduced, and therefore, the noise at the frequencies of these oscillations is reduced. Performing the specified ratios of the cross-sectional areas of the tube 8 and the openings 9 of the tube 8 provides the effect of damping resonant vibrations and a corresponding reduction in noise. 1 3.p. f-ly. 1 il. (L

Description

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The invention relates to mechanical engineering, in particular, to an engine-building, namely, to silencers of noise, mainly intake and exhaust — an internal combustion engine.

The purpose of the invention is to increase the efficiency of noise suppression.

The drawing shows a silencer, longitudinal section. TO

The muffler contains the body -1

with input 2 and output 3 TORTSOV1FSh

walls and inlet 4, partially placed in housing 1, and outlet 5 nozzles, at least one 15 transverse partition 6 dividing the housing into chambers 7, and an overflow tube 8 installed in the partition 6 and connecting adjacent ka-7, At least one 20 flexible tube 8 is provided with openings 9, which are formed in one transverse plane and located in chamber 7 according to the relations:

0.4 1g 1, f 0.6 1; 25 0.2 S S -0.5 S, - where 1- and S is the length and area of the passage section of the overflow pipe 8;

1. - the distance from the centers of 30 holes 9 to the end of the overflow pipe 8, Sg - the total area of the openings of the overflow pipe 8.0 25 The inlet 4 in the area of the chamber 7 can be provided with openings 10 made in one transverse plane.

The silencer operates in a manner that follows 40.

The gas flow through the inlet pipe 4 enters the first chamber 7 along the flow direction, where it expands. Next, the gas passes through the bypass tube B to the next one along the route, adjacent to the previous chamber 7 and, continuing to move, from the last chamber 7 through the outlet 5 is emitted into the atmosphere. The process of passing gas through the silencer is characterized by the reduction of noise levels. However, at the same time in the tube 8 resonant oscillations of the medium occur in the axial direction, the consequence of which is a decrease in the efficiency of damping noise at the frequencies of these oscillations. In tube 8, in the zones of its middle, the antinodes of the sound pressure of those resonant oscillations are established at which the length of tube 8 is equal to an odd integer number of half-waves. In the antinodes, the sound pressure varies over time in a wide dynamic range from vacuum to overpressure. At the same time, the medium in the holes 9 of the tube 8 makes an intensive oscillatory motion from the tube 8 into the chamber 7 and back. Due to the hydraulic energy loss of the resonant oscillations, the noise is reduced and, consequently, the noise is reduced by 4acTOTak of these oscillations. If the holes 9 are located at ratios 1 0.6 1 or 1. 0.4 1 of the antinodes of the sound pressure do not coincide with the holes 9, and consequently, the intensity of the oscillatory process from the tube 8 into the chamber 7 decreases, which reduces the noise attenuation efficiency.

. Performing the total area So of the openings 9 of the overflow tube 8 within the prescribed limits provides the effect of damping resonant oscillations and correspondingly reducing noise. When So 0.2 SJ-, the complex resistance of the holes 9 is excessively large, therefore, for resonant oscillations, they seem to be absent, and vice versa, with Sff 0.5 Sf, the total area of the holes 9 is so large that a significant part of the sound energy prodos Of these, mine is part of the tube 8, which practically does not participate in the process of noise suppression, as a result of which the efficiency of the silencer decreases.

When performing the inlet 4 with the holes 10, it works similarly to the overflow pipe 8.

Claims (2)

1. A silencer comprising a housing with inlet and outlet end walls, inlet partially dispersed in the housing and outlet nozzles and at least one transverse partition dividing the housing into chambers and provided with an overflow pipe connecting adjacent chambers, differing in That, in order to increase the efficiency of sound attenuation, at least one the overflow pipe is provided with openings made in the same transverse plane and located in the chamber according to the ratios 0.4 1g 1, 0.6 0.2 Sr BO, 0.5 S where IT and ST are respectively the length and area of the passage section of the overflow pipe; R - total area of the holes of the overflow tube; distance from the centers of the holes to the end of the overflow tube. 2. A silencer according to claim 1, characterized in that the inlet pipe in the area of the chamber is provided with openings made in one transverse plane.