KR20130033726A

KR20130033726A - Complex noise decreasing type muffler

Info

Publication number: KR20130033726A
Application number: KR1020110097587A
Authority: KR
Inventors: 공승태
Original assignee: 현대자동차주식회사; 기아자동차주식회사
Priority date: 2011-09-27
Filing date: 2011-09-27
Publication date: 2013-04-04

Abstract

PURPOSE: A composite noise reduction method muffler is provided to partition an internal space of the muffler into a high frequency noise reduction section using a glass wool and a specific frequency booming noise reduction section using a Helmholtz resonance action. CONSTITUTION: A composite noise reduction method muffler comprises a housing body(1) a baffle plate(4), a sound-absorbing material, and a resonator(10). A pipe where exhaust gas flows is penetrated through the housing body. The baffle plate is joined to the pipe and partitions the housing body into two front chamber(5) and a rear chamber(6). The sound-absorbing material is filled in the front chamber in a direction where the exhaust gas flows, thereby reducing noise of high frequencies with a sound-absorbing mode. The resonance discharges the exhaust gas to the rear chamber, thereby obtaining specific frequency booming noise reduction through a Helmholtz resonance action. [Reference numerals] (AA,CC) Inflow of exhaust gas; (BB,DD) Discharge of exhaust gas;

Description

Complex Noise Decreasing type Muffler

The present invention relates to a silencer, and more particularly, to a composite noise reduction type silencer capable of realizing noise reduction through an expansion method together with a sound absorption method.

In general, the muffler acts to lower the low frequency and high frequency airflows before the engine exhaust goes to the atmosphere, while increasing the back pressure to reduce the idle and low frequency booms, which can also cause adverse effects such as reduced output.

3 shows the internal construction of a conventional silencer.

As shown, the silencer is a sealed housing body 100 forming an interior space, an inlet pipe 20 through which exhaust gas is introduced and penetrated inside the housing body 100, and an interior of the housing body 100. Is connected to the inlet pipe 20 in the outlet pipe 30 to discharge the exhaust gas to the outside of the housing body 100, the inner space of the housing body 100 to the front chamber 50 and the rear end chamber 60 It is comprised by the baffle plate 40 to divide.

Two through holes 20a and 20b are formed in the inlet pipe 20 to discharge exhaust gas into the inner space of the housing body 100, and the two through holes 20a and 20b are located at the front and rear positions of the baffle plate 40. It is formed.

The baffle plate 40 is further provided with a plurality of holes baffle (40a) through which the exhaust gas passes, so that the exhaust gas from the through holes (20a, 20b) of the inlet pipe 20 and the shear chamber 50 The rear end chamber 60 can be circulated.

The front chamber 50 and the rear chamber 60 is filled with a sound absorbing material, the sound absorbing material is glass fiber (GLASS WOOL) is applied.

The silencer configured as described above can lower the high frequency bumming and high frequency airflow sounds, and in particular, improve the high frequency noise reduction performance by using a sound absorbing material.

Korean Patent Publication No. 10-2003-0041320 (2003.05.27) relates to a resonator, see FIGS. 1 and 2 on page 34 to 3 on page 26 on line.

However, the sound absorbing material has a limitation that the effect of reducing the booming noise on a specific frequency generating the booming noise by using the sound absorbing action can not be implemented at all.

In particular, when the sound absorbing material filling the inner space of the silencer is applied to glass fiber glass, the cost increase due to glass fiber as well as the cause of the weight increase of the sound absorber compared to the noise reduction effect due to the sound absorbing material. There is no choice but to work.

Accordingly, the present invention in view of the above point by applying the Helmholtz resonance section to replace the glass fiber (GLASS WOOL) in the silencer interior space, the sound-absorbing performance of the sound-absorbing method through the glass fiber (GLASS WOOL) as it is It aims to provide a composite noise reduction type silencer which greatly improves the cost and weight reduction, as well as the reduction performance of specific frequency booming noise through Helmholtz resonance.

Composite noise reduction type silencer of the present invention for achieving the above object and a housing body through which the pipe through which the exhaust gas flows;

A baffle plate coupled to the pipe and partitioning the housing body into two blocked front and rear chamber sections;

A sound absorbing material which is filled in a shear chamber in a direction in which the exhaust gas flows and reduces high frequency noise by a sound absorbing method;

A resonator provided in the rear chamber which is blocked by the front chamber and the baffle plate, and discharges exhaust gas to the rear chamber to implement a specific frequency booming noise reduction by Helmholtz resonance action;

And a control unit.

The pipe is composed of an inlet pipe leading from the front chamber to the rear chamber of the housing body and introducing the exhaust gas, and an outlet pipe connected to the inlet pipe at the rear chamber of the housing body.

The sound absorbing material surrounds the through hole drilled in the inlet pipe, and is made of glass fiber.

The resonator is formed in the inlet pipe at the portion before the outlet pipe is connected.

The resonator includes a neck portion communicating with the inside of the inlet pipe, and a resonance space portion protruding to the outer circumferential surface of the inlet pipe so as to form an expansion space following the neck portion and discharging exhaust gas into the rear end space.

The resonance space portion forms an open outlet opened in only one direction, and the open outlet is formed in a direction in which exhaust gas passes.

The present invention divides the interior space of the silencer into a sound absorbing method using a glass fiber glass (GLASS WOOL) by partitioning the high frequency noise reduction section and a specific frequency booming noise using a Helmholtz resonance action, a sound absorbing method through a glass fiber (GLASS WOOL) It will be effective to realize both the advantages of and the advantages of the resonance method.

In addition, the present invention by reducing the glass fiber (GLASS WOOL) filling section by adding the Helmholtz resonance action section, while reducing the specific frequency booming noise significantly improved performance and cost and weight reduction due to glass fiber (GLASS WOOL) There is also an effect.

1 (a), (b) is a block diagram of a composite noise reduction silencer according to the present invention, Figure 2 is a noise reduction operation of the composite noise reduction silencer according to the present invention, Figure 3 is a single conventional Noise reduction type Silencer

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Since the exemplary embodiments of the present invention may be embodied in various different forms, one of ordinary skill in the art to which the present invention pertains may be described herein. It is not limited to the Example to make.

1 shows a configuration of a composite noise reduction type silencer according to the present embodiment.

As shown in Figure 1 (a), the silencer is a sealed housing body (1) forming an internal space,

The inlet pipe 2 which flows in the exhaust gas and penetrates the inside of the housing body 1 and is connected to the inlet pipe 2 inside the housing body 1 to discharge the exhaust gas to the outside of the housing body 1. The outlet pipe 3 and the inner space of the housing body 1 are divided into the front chamber 5 and the rear chamber 6, and the baffle plate 4 which completely closes them between the front chamber 5 and the front chamber 5 is provided. It is composed of a sound absorbing material is filled with a sound absorbing method to reduce the high frequency noise by the sound absorbing method, and a resonator (10) provided with a rear stage chamber to implement a specific frequency booming noise reduction by the Helmholtz resonance action.

The sound absorbing material is glass fiber (GLASS WOOL) is applied.

The front chamber 5 is formed relatively shorter than the rear chamber 6 in the overall length of the housing body 1, but if the sound absorbing characteristics of the sound absorbing method to increase the noise reduction method can be formed vice versa do.

Figure 1 (b) is a cross-sectional structure of the silencer, as shown in the inlet pipe 2 is a single through hole (2a) to discharge the exhaust gas into the interior space of the housing body (1), the one through hole ( 2a) is formed in the front position of the baffle plate 4.

In addition, the resonator 10 is inserted into the inlet pipe (2) inside the neck portion 11 and communicated with the inside, and formed integrally with the neck portion 11 protrudes to the outer peripheral surface of the inlet pipe (2) to resonate the volume It consists of a resonance space portion 12 to form.

Here, the resonance space portion 12 forms an open outlet 12a opened only in the direction in which the exhaust gas passes.

2 shows a resonator operation of the composite noise reduction silencer according to the present embodiment.

As shown in the drawing, when the exhaust gas passes through the inlet pipe 2, a part of the exhaust gas exits the shear chamber 5 through the through hole 2 of the inlet pipe 2 and is absorbed by the sound absorbing material, thereby absorbing high frequency noise in a sound-absorbing manner. Will be reduced.

Subsequently, the exhaust gas flowing through the through hole 2 of the inlet pipe 2 flows out to the resonator 10 of the inlet pipe 2 before exiting with the flow out of the silencer through the outlet pipe 3. To form.

At this time, the exhaust gas stream exiting to the resonator 10 of the inlet pipe 2 reduces the specific frequency booming noise by implementing the Helmholtz resonance action.

That is, some of the exhaust gas reaching the resonator 10 branched to flow into the neck 11, and the exhaust gas passing the narrow cross-sectional area A of the neck 11 is the volume space of the resonance space 12. As it expands through (V) it is spread out to the rear chamber (6).

As described above, the exhaust gas passes through a narrow cross-sectional area (A) and then expands into a large volume space (V), thereby implementing Helmholtz resonance, thereby greatly reducing the specific frequency booming noise of the exhaust gas.

In general, the noise reduction performance of the resonator 10 is proportional to the neck cross-sectional area (A) and inversely proportional to the neck length and the volume of the resonant space, and thus the neck cross-sectional area (A) and the neck length (B), which are the performance factors of the resonator 10 And the correlation between the volume space (V) and the resonance space is selected at an appropriate ratio.

Experimentally, the maximum performance using the resonator 10 in this embodiment is a specific frequency booming through the resonator 10 when the total length L of the resonant space portion 12 is about 74 mm in consideration of the exhaust gas temperature. It is proved that noise reduction is realized to the maximum.

As described above, the silencer according to the present embodiment includes a chamber having a resonator 10 implementing sound absorption type high frequency noise reduction interval and Helmholtz resonance using the chamber 5 filled with glass fiber (GLASS WOOL) in its inner space ( 6) By dividing the specific frequency booming noise into the reduction section, in addition to the advantages of the sound absorbing method through the glass fiber (GLASS WOOL), while significantly improving the reduction performance of the specific frequency booming noise and the cost due to the glass fiber (GLASS WOOL) Weight reduction can also be implemented.

1: housing body 2: inlet pipe
2a: through hole 3: outlet pipe
4 baffle plate 5 shear chamber
6: rear chamber 10: resonator
11: neck 12: resonance space
12a: open exit
A: Resonance tree cross section L: Resonance tree length

Claims

A housing body through which the exhaust gas flows;
A baffle plate coupled to the pipe and partitioning the housing body into two blocked front and rear chamber sections;
A sound absorbing material which is filled in a shear chamber in a direction in which the exhaust gas flows and reduces high frequency noise by a sound absorbing method;
A resonator provided in the rear chamber which is blocked by the front chamber and the baffle plate, and discharges exhaust gas to the rear chamber to implement a specific frequency booming noise reduction by Helmholtz resonance action;
Composite noise reduction method silencer, characterized in that configured to include.

The pipe according to claim 1, wherein the pipe is composed of an inlet pipe which extends from the front chamber to the rear chamber section of the housing body and introduces the exhaust gas, and an outlet pipe connected to the inlet pipe at the rear chamber section of the housing body. Compound noise reduction type silencer

The method of claim 2, wherein the sound absorbing material surrounds the through-holes drilled in the inlet pipe, composite noise reduction type silencer, characterized in that made of glass fiber.

The silencer according to claim 2, wherein the resonator is formed in the inlet pipe at a portion before the outlet pipe is connected.

The resonator of claim 4, wherein the resonator comprises a neck portion communicated with the inside of the inlet pipe, and a resonance space portion protruding to the outer circumferential surface of the inlet pipe so as to form an expansion space following the neck portion and discharging exhaust gas to the rear end space. Compound noise reduction type silencer characterized by.

The silencer according to claim 5, wherein the resonance space portion forms an open outlet opened only in one direction.

The method of claim 6, wherein the open exit composite noise reduction silencer, characterized in that formed in the direction in which the exhaust gas passes.