RU2333369C2 - Internal combustion engine silencer - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: silencer incorporates, primarily, rectangular casing, inlet and outlet branch pipes, a lengthwise partition separating the casing into two, normally symmetric and identical resonance chambers. A variable-section opening is cut in the partition. For the improvement of the silencing effect, consecutively connected such silencers can be used.

EFFECT: efficient use of the silencer inner volume.

1 dwg

Description

The invention relates to the field of engineering and is intended primarily to damp exhaust noise in internal combustion engines.

Known silencer of gas flow noise for an internal combustion engine, comprising a housing and at least one perforated pipe placed therein, or a curved gas duct of three perforated pipes forming a common resonance chamber with the housing (see German application No. 3740341 of 11.27.97, cl F01N 1/08).

The design drawback is that the perforated hole does not absorb sound energy of the high-frequency spectrum of the noise field poorly. The silencer has a complex structure and detects a lack of technological development.

A gas flow silencer is also known, comprising a case with corrugations, in which parallel curved partitions are located, forming a curved channel that divides the body into three resonant chambers, interconnected by slots formed by the gap between the shelves of the partitions and the wall of the body (see.c. 1773279, CL F01N 1/10 dated 09.21.90).

The design flaws include the fact that the Helmholtz principle of resonant absorption of high-frequency sound in narrow channels that communicate with resonant cameras is not effectively used. The design is taken as a prototype.

The objective of the invention is the most efficient use of the volume of the muffler for sound absorption in a wide range of frequencies, including the high-frequency spectrum.

The problem is solved by the fact that in the gas flow silencer in a longitudinal partition dividing the housing into two resonant chambers, a window of a special shape is made that provides an inhomogeneous connection between the resonant chambers.

The invention is illustrated in the drawing, which shows a General view of the muffler.

The gas flow silencer comprises a rectangular housing 6 with end walls and parallel inlet 1 and 2 outlet pipes and a longitudinal partition 4 dividing the housing into two resonant chambers. The muffler works as follows. The exhaust gas stream enters through the inlet pipe 1 to the resonant chamber 3 of the duct, in which sound waves are partially reflected from the walls of the chamber 3. Then, passing through a window of a special shape of variable section 7 in the longitudinal partition, re-reflection and interference absorption occur due to the variable section of the window sound waves in the resonant chamber 5. The efficiency of reflection of sound energy is ensured by a specially selected window shape in the longitudinal partition, correctly selected widths and lengths of resonant chambers.

As practice shows, the frequency response of such a silencer has a pronounced form of a band-pass filter with a wide obstacle band and a very narrow pass band. With the correct selection of the shape of the window in the longitudinal partition, the correctly selected width and length of the resonance chambers, the frequency response of the silencer's fence band is superimposed on the spectrum of sound waves generated by the engine, which ensures effective noise reduction in a wide frequency range.

This design of the silencer provides high efficiency with the smallest dimensions of the housing 6, while the silencer has a small hydraulic resistance to gas flow.

Claims (1)

A gas flow silencer comprising a predominantly rectangular-shaped housing with end walls and parallel inlet and outlet pipes, characterized in that a window of variable cross section is made in the longitudinal partition dividing the housing into two resonant chambers.