KR101693887B1 - Muffler with multi-resonator for construction equipment - Google Patents

Abstract

The present invention relates to a silencer for a multi-resonator insert construction machine, and an object of the present invention is to provide a multiple resonator silencer capable of reducing noise in various frequency bands by providing a multiple resonator in a silencer for reducing exhaust gas noise of an engine There is.
The structure of the present invention comprises a cylindrical silencer case (1); An exhaust gas inflow pipe (2) of a porous structure penetrating in the lateral direction of the case (1); A first baffle 4 of a disk structure provided with a woodpipe 13 which forms an exciting first resonator 3 which is spaced apart from the one end of the case by a predetermined distance to isolate the space and reduce the noise of the main frequency band, and; And a second resonator (5) that is spaced apart from the other end of the case by a predetermined distance to isolate the space and reduce noise of a frequency band different from that of the first resonator, A baffle 6; A third baffle 11 and a fourth baffle 12 installed between the first baffle 4 and the second baffle 6 to isolate the case interior space; An exhaust gas outlet 19 provided above the space formed by the third baffle 11 and the fourth baffle 12 and penetrating the case; The first, third, and fourth baffles are disposed in the longitudinal direction of the case and are closed at both ends of at least one of the first, second, third, and fourth baffles (4, 6, 11, 12) (7, 8, 9, 10) of a multi-resonator insertion silencer for a construction equipment.

Description

Muffler with multi-resonator for construction equipment

The present invention relates to a silencer for a construction equipment in which a multi resonator capable of reducing noise in various frequency bands is inserted, and more particularly, to a silencer in which exhaust resonance noise is drastically reduced by inserting multiple resonators in a silencer for a construction equipment .

Generally, in automobiles and construction equipment, various types of silencers are installed to reduce the exhaust gas noise emitted from the engine.

Types of silencers include reflection type, interference type, complex type of interference reflection, absorption type, complex absorption type, and resonance type.

The reflective silencer is a silencer configured to attenuate noise by impact reflection action by continuously arranging a plurality of spaces in a row and arranging a through pipe in a partition forming each space to block the course of the pulsating exhaust gas several times,

The interference silencer is a silencer configured to eliminate noise by reducing the energy of the exhaust gas because the exhaust pipe has a structure of repeatedly branching and collecting,

The interference reflex type silencer is a silencer configured to attenuate the exhaust noise while simultaneously reflecting the exhaust noise through a plurality of noise tubes and a partitioned space,

The absorption silencer is a silencer constructed by a plurality of partition spaces, a partially perforated sound plate, and a porous sound absorbing material, and configured to introduce noise into the sound absorbing material charged into the partition space through holes drilled in the sound pipe,

Resonant silencer is a silencer constructed by using helmholtz resonance principle to reduce the volume of exhaust by designing multi-branched resonator with dimensions and shape suitable for exhaust noise reduction.

Here we briefly introduce the Helmholtz resonance principle. FIG. 7 is an illustration showing a general Helmholtz resonance principle and a principle disclosed in the prior art section of Korean Patent Application No. 10-2005-7020861. Hereinafter, reference numerals in FIG. 7 are used for descriptive convenience.

Referring to the drawings, the Helmholtz resonator is a chamber having an open throat. The amount of air located in the chamber and neck vibrates due to periodic compression of air in the chamber. This Helmholtz resonator can be attached to the exhaust pipe of the internal combustion engine and cancels the noise (usually 30 to 400 Hz) caused by the ignition of the piston of the internal combustion engine. A Helmholtz resonator 54 including a neck portion 54a having an inner diameter D _T and a length L _{T as} shown and a chamber portion 54b having an inner diameter D _C and a length L _C , And schematically shows a muffler 50 including a shell 52. As shown in Fig. Normally, the frequency at which the apex damping frequency of sound energy, that is, the transmission loss, is maximum is a function of the volume of the neck portion having the chamber portion 54b and the inner diameter D _T and the length L _T of the Helmholtz resonator 54 . For example, if the chamber volume increases and the neck with the inner diameter (D _T ), length (L _T ) remains the same, the peak damping frequency decreases and the chamber volume decreases, the peak damping frequency increases. When the Helmholtz resonator 54 is attached as a side branch, the side branch has both mass (inertia) and compliance. This acoustic system is a so-called Helmholtz resonator and works very much like a simple mass-spring damping system. This resonator has a neck with a diameter D _T , an area S _b , an effective neck length L _eff of L + 0.85D _T and a cavity volume V (a function of D _C and L _c ) . The cavity volume is resonant in frequency and interacts with energy during the course of resonance. All of the energy absorbed by the resonator in a portion of the acoustic cycle is returned to the pipe later in the cycle. The phase relationship is a relationship where energy is returned back to the source, that is, not sent below the duct. Since no energy is removed from the system, the actual part of the branch impedance (R _b ) is zero. The imaginary part of the impedance is expressed in terms of the compliance and inertia of the resonator and X _b = p (wL _eff / S _b - c ² / wV) and the sound power transmission coefficient .

식 (1)

Equation (1)

The transmitted force is such that the resonant frequency of the resonator is w = w ₀ in equation (1) when all of the energy is reflected back toward the source. These filters reduce the sound within the resonant frequency circumference band and pass all other frequencies. The narrow frequency range at which interference occurs is not a desirable condition in automotive exhaust, as the engine speed (RPM) changes and the frequency of acoustic energy changes as the temperature of the exhaust gas changes.

The application structure of a general resonance type silencer among various silencers as described above is shown in FIG. Fig. 8 is a technique disclosed in the prior art of Korean Utility Model Application No. 20-1996-0067175. Hereinafter, reference numerals in FIG. 8 are used for descriptive convenience. A three-way catalytic converter 107 connected by an exhaust manifold 103 and a bellows pipe 105, a front silencer 109, and a rear silencer 111 as shown in FIG. The rear silencer 111 represents a resonator for attenuating the main frequency noise. However, the silencer having such a resonator as a separate type requires a separate silencer such as a rear silencer 111 in order to remove noise in the main frequency band, so that the work process is increased and thus the cost is increased.

A conventional technique in which a resonator structure is integrally incorporated in a silencer to solve such a problem is Korean Utility Model Application No. 20-1996-0067175 shown in Fig. This technology is a technology that reduces the number of parts and the number of work processes due to the addition of a silencer, and simplifies the silencer manufacturing method by installing a complete resonance type noise attenuator in a small single silencer having a small cross-sectional area. Hereinafter, reference numerals in FIG. 9 will be used for descriptive convenience.

The case 3 includes a case 3 formed with an outer pipe and a plurality of through holes 5 formed in the outer circumferential face of the case 3 to be inserted into a space 10 defined by a baffle 7 inside the case 3, A plurality of through holes 15 are formed in the outer circumferential surface of the baffle 9 and the baffle 9 and another baffle 9 and the opposite side of the inlet pipe 11 is guided A bifurcation 21 is divided into a pipe 17 and an outlet pipe 19 through which a plurality of through holes 25 are passed. An outlet pipe 19 of the branch pipe 21 is connected to the baffle 9 And a sound absorbing material 27 surrounded by an outer circumferential surface exposed to the partitioned complete resonance chamber 23.

Such a conventional silencer having a damping branch has a great advantage, though only a small part of the exhaust gas flows into the resonator through the branch structure corresponding to the 'neck' structure of the Helmholtz resonator, The noise can be cut off and the remaining exhaust gas is discharged and the processing capacity for the entire exhaust gas is weak to apply to large construction equipment,

In addition, it has a disadvantage in that it can reduce only one selected frequency noise component of various noises, and thus has a weak expanding power such as attenuation ability for various frequency noises.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a multiple resonator insertion silencer capable of attenuating noise in various frequency bands by providing a resonator in a silencer for reducing exhaust gas noise of an engine.

Another object of the present invention is to provide a multiple resonator insertion silencer having a plurality of Helmholtz resonator structures, such as construction equipment, in which the exhaust gas noise of a capacity generated from an engine having a larger engine output than an automobile can be greatly attenuated.

According to an aspect of the present invention, there is provided a muffler case comprising: a cylindrical muffler casing;

An exhaust gas inlet pipe of a porous structure penetrating in the lateral direction of the case;

A first baffle having a disc-shaped disc structure provided with a first resonator for noise reduction of a target frequency, the first baffle being installed at one end of the case at a predetermined interval to isolate the space portion;

A second baffle having a disc-shaped disc structure in which a space is separated from the other side end of the case by a predetermined distance to form a second resonator for reducing frequency noise from the first resonator;

A third baffle and a fourth baffle installed between the first baffle and the second baffle to isolate the case interior space;

An exhaust gas outlet provided above the space formed by the second baffle and the fourth baffle and penetrating the case;

A first porous member which is installed in the longitudinal direction of the case and which has both side ends that pass through at least one of the first baffle, the second baffle, the third baffle, and the fourth baffle, A third multi-hole pipe, and a fourth multi-pipe pipe. The multi-resonator insertion muffler for a construction equipment according to the present invention is provided.

In a preferred embodiment of the present invention, the first porous pipe and the second porous pipe are installed at one side of the first baffle, and the other side of the first porous pipe and the second porous pipe may pass through the third baffle.

In a preferred embodiment of the present invention, the third porous pipe and the fourth porous pipe are installed on the third baffle, and the other side can be installed on the second baffle through the fourth baffle.

The first resonator and the second resonator may be spaced apart from each other by different distances from each other. The first resonator and the second resonator may be spaced apart from each other by a distance between the first baffle and the second baffle. Woodwinds formed in two baffles can have different lengths and cross-sectional areas.

In a preferred embodiment of the present invention, a plurality of wooden tubes formed in the first baffle and the second baffle may be formed.

As described above, according to the present invention, since two resonators are provided in the muffler, the mufflers can be reduced in noise of two or more frequency bands in one muffler,

In addition, a plurality of Helmholtz neck structures into which exhaust gas flows into the resonator chamber are provided so that the main frequency band noise of the exhaust gas of the capacity generated from the engine having a larger engine output, such as construction equipment, Which is advantageous in industrial use because it is advantageous in that the exhaust gas noise treatment efficiency is increased.

FIG. 1 is a cross-sectional view illustrating a structure of a multiple resonator insertion muffler according to an embodiment of the present invention.
FIG. 2 is a side view illustrating a structure of a multi-resonator insert muffler according to an embodiment of the present invention,
3 is a sectional view taken along line A-A 'in Fig. 1,
4 is an exemplary view showing a first baffle according to an embodiment,
5 is an exemplary view showing a second baffle according to an embodiment,
FIG. 6 is an exemplary view showing third and fourth baffles according to an embodiment,
FIG. 7 is an exemplary view showing a general Helmholtz resonance principle,
FIG. 8 is an exemplary view showing a conventional silencer using a resonator,
9 is an exemplary view showing a monolithic silencer in which a conventional resonator is inserted.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

FIG. 1 is a cross-sectional view illustrating a structure of a multiple resonator insertion type silencer according to one embodiment of the present invention, FIG. 2 is a side view illustrating a structure of a multiple resonator insertion silencer according to one embodiment of the present invention, 1 is a sectional view taken along the line A-A ', 4 is an exemplary view showing a first baffle according to one embodiment, FIG. 5 is an exemplary view showing a second baffle according to an embodiment, and FIG. Fig. 4 is a view showing the third and fourth baffles according to the present invention.

As shown in the drawings, the multiple resonator type silencer of the present invention has a porous exhaust gas inlet pipe 2, which is formed in a direction of one side of a cylindrical silencer case 1 and receives exhaust gas discharged from a manifold of the engine through the hole, As shown in Fig. The exhaust gas inflow pipe 2 is configured such that the surface thereof is formed in a porous structure having a plurality of holes formed therein, so that the exhaust gas is discharged into the case 1.

The case (1) is configured to divide and isolate the inner space by forming a plurality of disk-shaped baffles therein.

Specifically, a plurality of baffles according to the present invention are installed at one end of the case at a predetermined distance to isolate the space, thereby forming a first resonator 3 having a space volume for reducing noise. And a second baffle 6 of a disc structure which forms a second resonator 5 which is spaced apart from the other end of the case to isolate the space and reduce noise of a frequency band different from that of the first resonator, And a plurality of first porous pipes 7 installed in the same longitudinal direction as the case 1 installed between the first baffle 4 and the second baffle 6 to perform noise reduction and contaminant filtering, A third baffle 11 and a fourth baffle 12 through which a fourth porous baffle 10 and a second porous baffle 8, a third porous baffle 9 and a fourth porous baffle 10 are inserted.

The first resonator and the second resonator have different space capacities, thereby reducing the noise of various frequency bands according to the principle of the Helmholtz resonator.

The first porous pipe 7, the second porous pipe 8, the third porous pipe 9 and the fourth porous pipe 10 have a porous structure only in the circumferential direction, And the gas is discharged only through the porous structure in the circumferential direction.

The exhaust gas inlet pipe 2 is installed between the first baffle 4 and the third baffle 11.

The first multi-hole pipe 7, the second multi-hole pipe 8, the third multi-hole pipe 9 and the fourth multi-hole pipe 10, which are the plurality of pores, are installed at different positions on the baffle.

First, the first porous pipe 7 and the second porous pipe 8 are located inside the case 1 so as to be vertically symmetrical in the cross direction with respect to the exhaust gas inflow pipe 2 having a porous structure at the center, 1 baffle 4 and the other side is installed in the fourth baffle 12 through the third baffle 11.

Also, the third porous pipe 9 and the fourth porous pipe 10 are installed in a direction of one side of the exhaust gas inflow pipe 2 having a porous structure. The first porous pipe 7, And is symmetrically installed in the left-right direction in which the porous tube 8 is not located. The third porous pipe 9 and the fourth porous pipe 10 are provided so as to be in contact with the third baffle 11 at one side and the other side pass through the fourth baffle 12 to be brought into contact with the second baffle 6 do.

A plurality of resonator bobbins 13 protruding toward the first resonator 3 are formed in the first baffle 4. In the drawing, two right and left sides are formed. Also, the first baffle is pierced by the upper and lower pores of the pores, so that the first pores (7) and the second pores (8) pass through.

The second baffle 6 is also provided with a plurality of resonator bobbins 15 protruding toward the second resonator 5. In the drawing, three are formed in a triangular structure. In addition, the second baffle is pierced with the porous pipe holes 16 to the left and right so that the third porous pipe 9 and the fourth porous pipe 10 pass through.

The first resonator and the second resonator may be spaced apart from each other by different distances from each other. The first resonator and the second resonator may have different spatial volumes, Are formed to have different lengths and cross-sectional areas, noise of various frequency bands according to the Helmholtz resonator principle is reduced. That is, the role of the mass formed by the cross-sectional area and length of the wooden pipe depends on the relationship between the spring force provided by the air by the space volume formed by the first resonator and the second resonator, and the frictional resistance of air passing through the wooden pipe As the resonance takes place, the acoustic energy is reduced by converting into thermal energy accompanied by a violent vibration. Since the above description itself is a principle of a general Helmholtz resonator, the above-mentioned contents are sufficient, and the Helmholtz resonator principle itself is not invented in the present invention, and therefore, a detailed description thereof will be omitted.

The third and fourth baffles 11 and 12 are provided with a first porous pipe 7, a second porous pipe 8, a third porous pipe 9 and a porous pipe hole for the fourth porous pipe 10 17 and 18 are formed so that the first porous pipe 7, the second porous pipe 8, the third porous pipe 9 and the fourth porous pipe 10 pass through and are supported.

An exhaust gas outlet 19 is formed in the upper part of the space formed by the fourth baffle 12 and the second baffle 6 and through the first resonator 3 and the second resonator 5 The exhaust gas whose noise in various frequency bands is reduced is discharged.

Sound absorbing materials 20 and 21 made of fiberglass materials are provided on one side and the other side of the first resonator 3 and the second resonator 5 which are not in contact with the case where no baffle is provided, .

The sound absorption process in the first and second resonators using the exhaust gas flow path and Helmholtz resonance of the present invention will be described.

The exhaust gas from each cylinder discharged from the combustion process of the engine is supplied to the exhaust gas inflow pipe 2 through the manifold located at the upper portion of the engine and flows through the porous structure of the exhaust gas inflow pipe into the first baffle 4 and the third baffle 4, A part of the exhaust gas discharged into the space provided by the first baffle 11 flows into the first resonator through the plurality of bokeh pipes 13 formed in the first baffle 4, 1 and the second porous pipe 8 and some of the exhaust gas that has not flowed into the first resonator flows into the first porous pipe 7 and the second porous pipe 8 through the pores of the first porous pipe 7 and the second porous pipe 8 .

The introduced exhaust gas is discharged to one end area of the first porous pipe 7 and the second porous pipe 8, that is, the space formed by the third baffle 11 and the fourth baffle 12, And flows through the holes formed in the cavity 9 and the fourth porous tube 10.

The exhaust gas flowing into the third porous pipe 9 and the fourth porous pipe 10 is discharged to the space formed by the fourth baffle 12 and the second baffle 6 through the second baffle 6, The noise is reduced in a plurality of frequency bands due to the structure of the second resonator 5 through the woodwind 15 formed in the first resonator 5, And is exhausted through the exhaust port 19.

The exhaust gas passing through the silencer of the present invention as described above can pass through two resonators having different spatial volumes so that a maximum of two specific frequencies can be processed in one silencer. The exhaust gas is exhausted in multiple stages through the first resonator and the second resonator while passing through the exhaust passage composed of multiple stages, so that the noise reduction performance is also increased.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims and their equivalents. Of course, such modifications are within the scope of the claims.

Description of the Related Art
(1): Case (2): Exhaust gas inlet pipe
(3): first resonator (4): first baffle
(5): second resonator (6): second baffle
(7): first porous pipe (8): second porous pipe
(9): third porosity (10): fourth porosity
(11): third baffle (12): fourth baffle
(13, 15): Woodwinds (14, 16, 17, 18): Perforated pipe holes
(19): Outlets (20, 21): Sound absorbing material

Claims (5)

A cylindrical silencer case (1);
An exhaust gas inflow pipe (2) of a porous structure penetrating in the lateral direction of the case (1);
A first baffle (4) of a circular plate structure provided with a wooden pipe (13) which forms an exciting first resonator (3) installed at one end of the case at a predetermined interval to isolate the space portion and reduce a specific frequency;
And a second resonator (5) which is spaced apart from the other end of the case at a predetermined interval to isolate the space and reduce noise in a frequency band different from that of the first resonator, and a second baffle (6);
A third baffle 11 and a fourth baffle 12 installed between the first baffle 4 and the second baffle 6 to isolate the case interior space;
An exhaust gas outlet 19 provided above the space formed by the second baffle 6 and the fourth baffle 12 and penetrating the case;
Both ends of the first baffle (4), the second baffle (6), the third baffle (11), and the fourth baffle (12) A first porous pipe 7, a second porous pipe 8, a third porous pipe 9 and a fourth porous pipe 10,
The first porous pipe 7 and the second porous pipe 8 are installed on the first baffle 4 at one side and the fourth baffle 12 through the third baffle 11 Multi resonator insert silencer for construction equipment.
delete The method according to claim 1,
The third porous pipe 9 and the fourth porous pipe 10 are installed on the third baffle 11 on one side and the second baffle 6 penetrates the fourth baffle 12 on the other side Multiple resonator inserts Silencers for construction equipment.
The method according to claim 1,
The first baffle and the second baffle forming the first resonator and the second resonator have different spacing distances from each other to have different spatial volumes,
Wherein the first baffle and the second baffle are formed to have different lengths and cross-sectional areas.
The method according to claim 1,
Wherein a plurality of woodwinds (13) formed in the first baffle and the second baffle are formed.

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