WO2019216564A1

WO2019216564A1 - Muffler having noise reduction structure using spiral steel pipe and method for manufacturing same

Info

Publication number: WO2019216564A1
Application number: PCT/KR2019/004588
Authority: WO
Inventors: 김영권
Original assignee: 주식회사 코어볼트
Priority date: 2018-05-09
Filing date: 2019-04-16
Publication date: 2019-11-14
Also published as: KR101890335B1

Abstract

Disclosed is a muffler having a noise reduction structure using a spiral steel pipe. The present invention comprises: an outer shell having a hollow formed therein and having open both ends; an inner shell mounted inside the outer shell to correspond longitudinally to the outer shell; a sound absorbing material surrounding the inner shell and filled in the outer shell; a pair of closing caps coupled to the both ends of the outer shell; and a spiral blade of a spiral structure having pitches at equal intervals. Here, the inner shell, which has a pipe shape in which both ends thereof are opened and a plurality of through holes being perforated and formed along the outer circumferential surface thereof, is a spiral steel pipe formed in a spiral shape while fixing an overlapping portion of a band steel to form a fixture portion, wherein a spiral groove is formed to be repeated at the same pitch as the fixture portion, and wherein a spiral end portion of the spiral blade is threaded into the spiral groove to be mounted and fixed inside the inner shell.

Description

Muffler with noise reduction structure using spiral steel pipe and manufacturing method thereof

The present invention relates to a muffler used to reduce intake and exhaust noise of an internal combustion engine and directional noise generated in an exhaust system.

More specifically, it relates to a muffler having a noise reduction structure using a spiral steel pipe.

Mufflers are used to reduce noise from internal combustion engines and ventilators.

Noise reduction is achieved through the sound insulation effect using transmission loss or the sound absorption effect to minimize wave reflection. In general, the noise reduction structure increases the resistance to the exhaust flow, thus improving the noise reduction capability of the muffler and lowering the output of the internal combustion engine. Tends to lead to

Therefore, the muffler should be designed in a structure that effectively reduces noise but does not cause an increase in exhaust pressure.

1 illustrates the structure of a muffler according to the prior art.

Figure 1 (a) is a type of straight muffler in which air flow introduced into the muffler is discharged as it is in a straight line. By forming a plurality of through holes on the outside of the pipe to allow a part of the air flow to flow into the space inside the shell, it is possible to reduce the noise due to pressure drop.

Since the high-pressure air flow is discharged in a straight line, the noise is relatively high, but the resistance to the exhaust flow is not great, which helps maintain the performance of the internal combustion engine.

Figure 1 (b) is a maze type muffler in which the inlet pipe and the exhaust pipe are separated from each other instead of being connected in a straight line.

The inside of the shell is divided into a plurality of compartments, and through the through-holes formed in the inlet pipe, the air flow exited into the space inside each compartment is pushed into the through-holes formed in the exhaust pipe is transferred to the next compartment.

Although the noise reduction efficiency is high in structure, there is a disadvantage in that resistance to exhaust flow is increased because it is discharged by back pressure.

That is, although the noise reduction effect is excellent, there is a disadvantage that the performance of the internal combustion engine is lowered.

An object of the present invention is to provide a muffler that minimizes the decrease in performance by adopting a straight pipe structure and significantly reduces noise through a spiral flow path. That is, an object thereof is to provide a muffler having a high noise reduction efficiency while minimizing performance reduction.

On the other hand, another object of the present invention is to omit the welding process at all, or to minimize the welding process by inserting the member of the spiral structure along the spiral groove formed in the spiral steel pipe and simply fixing at both ends The present invention provides a muffler structure that can be manufactured.

Muffler having a noise reduction structure using a spiral steel pipe according to an embodiment of the present invention to achieve the above object,

An outer shell having a hollow formed therein and having open ends at both ends thereof;

An inner shell mounted inside the outer shell to coincide with a length direction of the outer shell;

Sound absorbing material surrounding the inner shell and filled in the outer shell;

A pair of closing caps coupled to both ends of the outer shell; And

And spiral wings of a spiral structure having pitches at equal intervals.

At this time, the inner shell has a pipe shape in which both ends are opened, and a plurality of through holes are formed along the outer circumferential surface,

The inner shell is a spiral steel pipe which is formed in a spiral shape by fixing the overlapping portions of the strip steel, and is formed in a spiral shape, and a spiral groove which is repeated at the same pitch as the fixing part may be formed. At this time, the fixing portion and the spiral groove may be spaced apart or overlap a predetermined distance.

On the other hand, the spiral end portion of the spiral blade is fitted into the spiral groove can be mounted and fixed inside the inner shell.

On the other hand, at least one of both ends of the inner shell, the fixing frame having a border of the shape corresponding to the cross-sectional shape of the inner shell or outer shell; may be further provided, the center portion of the fixing frame is formed by drilling or recessed insert The ball may be provided.

Protruding portions protruding by a predetermined length may be provided at both sides of the rotating shaft of the spiral blade, and the protruding portions may be inserted into the insertion holes of the fixing frame.

On the other hand, to achieve the above object, a muffler having a noise reduction structure using a spiral steel pipe according to this embodiment of the present invention, a pipe-shaped inner shell of which both ends are opened;

Spiral wings having a pitch of equal intervals; And

And a pair of closing caps fastened to both ends of the inner shell.

At this time, the inner shell is a spiral steel pipe formed by fixing the overlapping portion of the band steel to form a spiral, spirally formed, and the spiral groove repeated at the same pitch as the fixing portion spaced apart from the fixed portion or a predetermined distance Formed,

The spiral end portion of the spiral blade is inserted into the spiral groove to be mounted and fixed inside the inner shell.

On the other hand, in order to achieve the above object, a method of manufacturing a muffler having a noise reduction structure using a spiral steel pipe according to the present invention,

Preparing an inner shell by cutting a spiral steel pipe having a spiral groove;

Inserting a spiral blade into the inner shell of the inner shell, and screwing the spiral end portion of the spiral blade into the spiral groove of the inner shell;

Wrapping the sound absorbing material to the outside of the inner shell, and inserting the sound absorbing material and the inner shell into the outer shell; And

Fastening the closing cap; may include.

According to the present invention, it is possible to effectively reduce the exhaust noise by the dual structure of the sound absorption for the noise leaked through the sound insulation and through the hole by the spiral structure.

On the other hand, since the airflow discharged from the internal combustion engine is discharged in a straight line, the resistance to the flow of the exhaust does not increase significantly. Therefore, there is an effect capable of bringing out performance comparable to that of the straight muffler.

In addition, by using a spiral steel pipe with ribs, it is possible to mount the spiral structure inside the muffler by simple assembly without welding. Accordingly, not only the defect rate in the assembly process is significantly lowered, but also the manufacturing cost is significantly lowered.

1 is a view showing the structure of a muffler according to the prior art,

2 is a view showing a coupling relationship between the components of the noise reduction muffler using a spiral steel pipe according to an embodiment of the present invention,

3 is a cross-sectional view of the noise reduction muffler using the spiral steel pipe illustrated in FIG.

4 is a view for explaining a principle that noise is reduced in the process of the discharged air flow is discharged,

5 is a view showing a state that the spiral wing is inserted along the spiral groove,

6 is a view for explaining the structure of the inner shell made of spiral steel pipe,

7 is a view for explaining a method of fixing the spiral blade using a fixing frame,

8 is a view showing a coupling relationship between the components of the noise reduction muffler using spiral steel pipe according to this embodiment of the present invention;

9 is a flowchart illustrating a method of manufacturing a noise reduction muffler using a spiral steel pipe according to the present invention in time series.

Explanation of Drawing References

110: outer shell

120: incoming pipe

130: discharge pipe

131: filter

140: finishing cap

150: fixed frame

151: insertion hole

153: fastening member

160: sound absorbing material

170: spiral wing

171: protrusion

172: long study

180: inner shell

181: fixed part

182: spiral groove

183: through

Hereinafter, with reference to the preferred embodiments of the present invention and the accompanying drawings will be described in detail, the same reference numerals in the drawings will be described on the assumption that the same components.

When any one element in the description or claims of the invention "includes" another element, unless otherwise stated, it is not limited to consisting only of that element, and other elements are not interpreted. It should be understood that it may include more.

2 is a view showing a coupling relationship between the components of the noise reduction muffler using a spiral steel pipe according to an embodiment of the present invention.

As shown in Figure 2, the muffler having a noise reduction structure using a spiral steel pipe according to the present invention, both the outer shell 110 and the outer shell of the outer shell having a hollow formed inside and both ends of the structure is open. It has a closing cap 140 is fastened to. One end cap 140 may be provided with an inlet pipe 120 through which air flows from an internal combustion engine or a ventilation device. Inlet pipe 120 may be manufactured integrally with the closing cap 140, or may be manufactured and assembled as a separate member.

The other end cap 140 is further provided with a separate discharge pipe 130 may discharge the air flow passing through the outer shell 110 to the outside. The discharge pipe 130 may be manufactured as a separate product, commonly referred to as a muffler tip, and may be fastened to the other end cap 140.

The outer shell 110, the closing cap 140, the inlet pipe 120 and the discharge pipe 130 are each made of a metal material and can be fastened or fixed to each other by a fastening means such as rivets, welding or screws.

In the example of FIG. 2, the outer shell 110 is shown as having a cylindrical shape with both ends open, but this is merely illustrative and the shape of the outer shell 110 may be a square pillar or other shape.

However, as will be described later, since the inner shell 180 has a cylindrical shape, it is preferable that the outer shell 110 also has a cylindrical shape to ensure ease of assembly and a uniform noise reduction effect.

Meanwhile, inside the outer shell 110, the suction member 160, the inner shell 180, and the spiral wing 170 are mounted, and the fixing frame 150 is mounted on both sides of the inner shell 180.

3 is a cross-sectional view of a noise reduction muffler using a spiral steel pipe according to the embodiment shown in FIG. 2.

As shown in FIG. 3, the inner shell 180 is inserted into the outer shell 110 in parallel to the longitudinal direction of the outer shell 110, and the outer circumferential surface of the inner shell 180 and the outer shell 110 are provided. Sound absorbing material 160 is filled into the space between the inner peripheral surface of the.

The inner shell 180 is made of spiral steel as described below, and has a cylindrical shape with both ends open.

Meanwhile, the inner shell 180 is formed by drilling a plurality of through holes 183 along the outer circumferential surface.

Known sound absorbing materials include a porous sound absorbing material and a plate vibration absorbing material. The sound absorbing material 160 of the present invention uses a non-combustible porous sound absorbing material such as glass wool or rock wool to simplify the manufacturing process. This is preferred.

Spiral wing 170 is a member having a spiral structure, the material is preferably a metal. On the other hand, the spiral blade 170 has a pitch of equal intervals.

4 illustrates the principle that noise is reduced in the process of discharging the introduced airflow.

Since the spiral end portion of the spiral wing 170 is in close contact with the inner circumferential surface of the inner shell 180 as described below, there is no gap between the spiral wing 170 and the inner shell 180, and thus the inlet pipe 120 Air flow introduced through the) is transported to the discharge pipe 130 along the flow path formed by the spiral wing 170.

In the case of the straight pipe muffler shown in FIG. 1 (a), the air flow is transferred in a straight path from the inlet pipe 120 to the discharge pipe 130. In the present invention, the feed path of the air flow is caused by the spiral wing 170. It will be much longer.

At this time, as shown in Figure 4, each pitch of the spiral wing 170 serves as a sound insulation wall.

The effect of the sound insulation is explained by the transmission loss (Transmission Loss) by the following equation (1).

However, P _i : energy of incident sound, P _t: transmission energy

[Equation 1]

A part of the noise introduced into the muffler is lost due to transmission loss when the spiral wing 170 penetrates, and a part of the noise is introduced into the sound absorbing material 160 through a minute through hole 183 formed along the outer circumferential surface of the inner shell 180 and then the sound absorbing material. (160) In the voids inside the medium is converted into heat energy by the change of the medium is lost.

On the other hand, the spiral wing 170 has a structure that is extended by the same pitch is repeated, at this time, by the air spring (Air Spring) formed between each pitch can obtain the sound insulation performance of the same principle as a multi-wall.

The noise is reduced by the mechanism of sound insulation and sound absorption.

That is, the noise of the airflow introduced through the inlet pipe 120 is primarily reduced while passing through the sound insulation wall formed by the spiral wing 170 and the inner shell 180 and flows out through the air hole 183. Since the noise has a secondary disappearance in the cavity inside the sound absorbing material 160, the exhaust is made to the discharge pipe 130 with most of the noise removed.

On the other hand, the maze type muffler shown in FIG. 1 (b) has a problem in that the exhaust resistance is increased due to a large number of partition walls, leading to a decrease in output of an internal combustion engine, but the muffler according to the present invention has a high airflow over the entire section. Since it is discharged to the discharge pipe 130 while maintaining the pressure and the flow rate, the output of the internal combustion engine, such as compared to the straight pipe muffler shown in Figure 1 (a) was confirmed to the test results to a slight level.

That is, while maintaining the same performance as the straight muffler shown in Fig. 1 (a), it was confirmed that the noise reduction effect of the maze type muffler as shown in Fig. 1 (b) at the same time.

On the other hand, Figure 5 is a view showing a state in which the spiral blade is inserted along the spiral groove.

The muffler is generally made of metal because the muffler is to be discharged after reducing the noise from the high temperature and high pressure air flow discharged from the internal combustion engine or the like, and it is generally manufactured by joining each member by welding.

Therefore, in the case of a structure that is inappropriate for joining by a welding method, the manufacturing cost may be greatly increased or manufacturing itself may be impossible.

It can be seen that the prior art shown in (a) and (b) of FIG. 1 also has an easy structure for welding each member.

By the way, the muffler according to the present invention should be fixed in close contact with the spiral wing 170 inside the inner shell 180, but the structural welding is impossible.

However, when the spiral wing 170 is simply pushed into the inner shell 180 to be fixed at both ends, the inner shell 180 may rotate and may cause a secondary noise, as well as durability. This greatly lowers the risk of breakage.

To solve this problem, an inner shell 180 having a structure of a spiral steel pipe as shown in FIG. 6 is used.

The spiral steel pipe may be manufactured by winding two sheets of long metal sheets (strap steel) and then rolling them in a manner such that the overlapped portions are fixed by folding the overlapped portions to form a lock seam.

In addition, a method of joining, crimping, welding, or the like may be used to fix the overlapped portions of the strip steel. Although FIG. 6 shows a spiral steel pipe manufactured in a manner of forming a lock core, the steel sheet may be manufactured by other methods. It's okay.

Hereinafter, the overlapping portion of the band steel is referred to as a fixed portion 181, but is shown in the shape of the lock core in Figure 6, but is not limited thereto.

On the other hand, according to the present invention, the inner shell 180 is further provided with a spiral groove 182 recessed in a predetermined depth in the outward direction, in parallel with the fixing portion 181 leading in a spiral. In addition, countless through holes 183 are formed through the entire area.

On the other hand, in the example shown in Figure 6, although the fixed portion 181 and the spiral groove 182 is shown as being spaced apart a predetermined distance, the separation distance between the fixed portion 181 and the spiral groove 182 is not determined and the design Accordingly, the spiral groove 182 may be formed to overlap with the fixing portion 181.

After forming the spiral groove 182 in the metal plate formed with a number of through holes 183, the spiral steel pipe can be manufactured by the method of winding the lock seam, and cutting it to manufacture the inner shell 180.

The spiral groove 182 and the fixed portion 181 have the same pitch. Therefore, the spiral groove 182 and the fixed portion 181 are connected in a spiral in parallel with each other.

As shown in FIG. 5, the spiral end portion of the spiral wing 170, that is, the corner portion extending in the spiral direction, is fitted into the spiral groove 182.

The spiral blade 170 may be inserted by turning the spiral blade 170 in a state where a spiral end portion of the spiral blade 170 is inserted into one end of the spiral groove 182.

It is preferable that the pitch of the spiral blade 170 and the spiral groove 182 have the same pitch, and make the diameter of the spiral groove 182 the same as the diameter of the spiral wing 170 or the diameter of the spiral groove 182. By making it slightly smaller within the error range, it can be secured when the spiral wing 170 is mounted inside the inner shell 180 by a twisting method.

Therefore, it is possible to securely fix the spiral blade 170 even when the spiral blade 170 is not bonded to the inner shell 180 by the welding method. By adopting such a structure, the manufacturing process can be simplified and the cost can be reduced.

However, structurally, the inner shell 180 and the spiral wing 170 mounted on the inner shell 180 are not fixed and are seated on the outer shell 110 by the sound absorbing material 160. The lower portion of the 160 is pressed, which causes internal play, and the sound absorbing performance may be significantly reduced. This problem is solved by using the fixing frame (150).

7 illustrates a method of fixing a spiral wing using a fixing frame.

Fixing frame 150 has an edge 152 corresponding to the cross-sectional shape of the outer shell 110, the diameter of the edge 152 is slightly smaller than the diameter of the outer shell 110, so that the outer shell 110 It can be mounted inward.

On the other hand, the fixing frame 150 has a shape in which the inside of the rim is mostly opened, it has an insertion hole 151 formed by drilling or recessing the inner central portion.

Spiral wing 170 is formed along the axis of rotation, protruding portion 171 protruding by a predetermined length in both sides in the longitudinal direction, the projection 171 is inserted into the insertion hole (170) by pushing the fixing frame 150 into the shell (110). 151 is inserted into the interior.

The protrusion 171 may have a cylindrical shape filled inside or a hollow pipe inside, and may protrude to both sides in the longitudinal direction of the spiral wing 170.

The spiral wing 170 has a hollow pipe-shaped shaft in the central longitudinal direction in order to take advantage of processing advantages and to suppress weight increase.

By forming an axis in the shape of a pipe having a predetermined diameter, it is possible to minimize breakage or deformation in the manufacturing process.

When the protrusion 171 has a shape as illustrated in FIG. 7, a separate fastening member 153 may be further provided to block both ends of the protrusion and at the same time fix the fixing part 150.

After the protrusion 171 is inserted into the insertion hole 151 of the fixing frame 150 and assembled to be exposed to the outside, the thread formed along the outer circumferential surface of the protrusion 171 is rotated to engage the thread of the inner circumferential surface of the fastening member 153. Can be tightened.

By adopting the structure as described above, it is possible to securely seat and fix the spiral blade 170 inside the outer shell 110 without welding. In particular, while manufacturing the inner shell 180 using a spiral steel pipe, by forming a spiral groove 182 parallel to the fixed portion 181 by screwing the spiral wing 170 inside the spiral wing mounting portion 180 It is possible to assemble, which simplifies the process, lowers the defect rate and reduces manufacturing costs.

Hereinafter, a structure of a noise reduction muffler using a spiral steel pipe according to this embodiment of the present invention will be described with reference to FIG. 8.

8 is a view showing a coupling relationship between the components of the noise reduction muffler using a spiral steel pipe according to this embodiment of the present invention.

As shown in FIG. 8, unlike the embodiment of the present invention shown in FIG. 2, the outer shell and the suction member are excluded.

That is, according to this embodiment of the present invention shown in Figure 8, the noise reduction muffler has a pipe-shaped inner shell 180, which is open at both ends, and has a pitch of equal intervals to the inner shell 180; It has a spiral wing 170 of the spiral structure to be mounted and a pair of closing caps 140 which are fastened to both ends of the inner shell 180.

At this time, the inner shell 180 is a spiral steel pipe formed in a spiral shape to form a fixing portion 181 by fixing the overlapping portion of the band steel as in one embodiment, the spiral is repeated at the same pitch as the fixing portion 181 Grooves 182 are formed.

However, unlike the embodiment, since the inner shell 180 is not surrounded by the sound absorbing material, the inner shell 180 preferably does not form a through hole on the outer circumferential surface thereof, and the rest of the configuration is the same as that of the embodiment.

Meanwhile, as illustrated in FIG. 8, a filter 131 may be further provided to prevent the inflow of foreign substances into the discharge pipe 130.

Hereinafter, a method of manufacturing a noise reduction muffler using a spiral steel pipe according to the present invention will be described with reference to FIG. 9.

First, a spiral groove 182 is formed in a strip steel, and then spiral steel pipes are manufactured by stacking two strips of steel and rolling a lock core. Then, the inner shell 180 is prepared by cutting it to an appropriate length (S1).

In order to manufacture the noise reduction muffler according to the embodiment, a band steel in which a plurality of through holes 183 are formed is used, and in the manufacture of the noise reduction muffler according to this embodiment, a band steel in which no through holes are formed is used.

Meanwhile, a spiral wing 170 having a spiral structure having the same pitch as that of the spiral groove 182 of the inner shell 180 is prepared, and is mounted by being screwed into the inner shell 180 (S2).

When manufacturing the noise reduction muffler according to one embodiment, the inner shell 180 is wrapped in the sound absorbing material 160 and inserted into the outer shell 110 as follows (S3).

However, this step is omitted in the manufacture of the noise reduction muffler according to this embodiment.

Thereafter, the fixing frame 150 is seated at both ends of the outer shell 110 and / or the inner shell 180.

At this time, the protrusions 171 at both ends of the spiral wing 170 is pushed into the outer shell 110 so that the fixing frame 150 is inserted into the insertion hole 151 formed in the center of the fixing frame 150 (S4). .

When the spiral wing 170 is secured by the fixing frame 150 as described above, the cap armor cap 140 is brought into close contact with both ends of the outer shell 110 and fastened or welded using bolts and nuts. Finish (S5).

Inlet pipe 120 or discharge pipe 130 may be separately mounted to the closing cap 140.

By such a process, a muffler having a noise reduction structure using a spiral steel pipe according to the present invention is manufactured. In particular, the spiral wing 170 may be mounted on the inner shell 180 or may be firmly fixed without welding in the process of fixing the fixing blade 150.

The technical spirit of the present invention has been described through several embodiments.

It will be apparent to those skilled in the art that the present invention may be variously modified or changed from the description of the present invention. In addition, even if not explicitly shown or described, those skilled in the art to which the present invention pertains various modifications, including the technical idea according to the present invention from the description of the present invention. Is obvious, and still belongs to the scope of the present invention. The above embodiments described with reference to the accompanying drawings are described for the purpose of illustrating the present invention, and the scope of the present invention is not limited to these embodiments.

The present invention can be applied to an exhaust system of a ventilation facility or an internal combustion engine.

Claims

An outer shell having a hollow formed therein and having open ends at both ends thereof;

An inner shell mounted inside the outer shell to coincide with a length direction of the outer shell;

Sound absorbing material surrounding the inner shell and filled in the outer shell;

A pair of closing caps coupled to both ends of the outer shell; And

Spiral wings of the spiral structure having a pitch of equal intervals; provided with,

The inner shell has a pipe shape in which both ends are opened, and a plurality of through holes are formed along the outer circumferential surface thereof.

The inner shell is a spiral steel pipe formed in a spiral shape by fixing the overlapping portions of the band steel, the spiral groove is formed to be repeated at the same pitch as the fixing portion,

Muffler having a noise reduction structure using a spiral steel pipe, characterized in that the spiral end portion of the spiral blade is inserted into the inner side of the spiral groove is mounted and fixed inside the inner shell.
The method of claim 1,

And a fixing frame having at least one edge of a shape corresponding to a cross-sectional shape of the inner shell or the outer shell, on at least one of both ends of the inner shell.

Muffler having a noise reduction structure using a spiral steel pipe, characterized in that the insertion hole formed by drilling or recessing the central portion of the fixing frame is further formed.
The method of claim 2,

To both sides of the rotating shaft of the spiral blade, a protrusion formed to protrude by a predetermined length is further provided,

The protrusion has a noise reduction structure using a spiral steel pipe, characterized in that inserted into the insertion hole of the fixing frame.
An inner shell of a pipe shape having both ends opened;

Spiral wings having a pitch of equal intervals; And

A pair of closing caps fastened to both ends of the inner shell;

The inner shell is a spiral steel pipe formed in a spiral shape by fixing the overlapping portions of the band steel, the spiral groove is formed to be repeated at the same pitch as the fixing portion,

Muffler having a noise reduction structure using a spiral steel pipe, characterized in that the spiral end portion of the spiral blade is inserted into the inner side of the spiral groove is mounted and fixed inside the inner shell.
Preparing an inner shell by cutting a spiral steel pipe having a spiral groove;

Inserting a spiral blade into the inner shell of the inner shell, and screwing the spiral end portion of the spiral blade into the spiral groove of the inner shell; And

Fastening the closing cap; Method of manufacturing a muffler comprising a.
The method of claim 5,

Wrapping the sound absorbing material to the outside of the inner shell, inserting the sound absorbing material and the inner shell into the outer shell; manufacturing method of the muffler further comprising.