KR101326511B1 - Muffler for vehicle - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile exhaust system muffler mounted on a vehicle to reduce exhaust noise of an engine. More particularly, the present invention relates to an automobile exhaust system muffler for improving fuel efficiency and reducing thermal damage of peripheral components by reducing the weight of components. .
To this end, the present invention, the case outer layer of the plastic material disposed at the outermost, the intermediate insulation layer disposed inside the case outer layer and containing an airgel material and the case inner layer of stainless steel material disposed inside the intermediate insulation layer Provided is a vehicle exhaust system muffler comprising a hollow case of a triple material formed by laminating (iii).

Description

Exhaust system muffler for automobiles {Muffler for vehicle}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile exhaust system muffler mounted on a vehicle to reduce exhaust noise of an engine. More particularly, the present invention relates to an automobile exhaust system muffler for improving fuel efficiency and reducing thermal damage of peripheral components by reducing the weight of components. .

In general, an exhaust system for discharging exhaust gas generated from an engine of a vehicle is provided with a muffler capable of attenuating exhaust noise on an exhaust line leading the exhaust gas to the rear side of the vehicle.

Such a muffler lowers the exhaust noise by lowering the temperature and pressure of the exhaust gas discharged from the engine, and is classified into various types according to its structure.

Conventional automobile main muffler is made of metal material to withstand high temperature exhaust gas in reducing engine exhaust noise generated in engine combustion process, and is mostly made of stainless steel to prevent corrosion promotion by high temperature environment. Was prepared.

The conventional muffler has a structure in which the internal space is divided into a plurality of chambers through a plurality of partitions (baffles) in order to increase the attenuation effect of the exhaust noise therein, and the noise of the exhaust gas passes through the chambers in the muffler. Noise is gradually attenuated by the interference of sound waves, a decrease in pressure fluctuations, and a decrease in exhaust temperature.

However, the conventional muffler made of stainless steel has a high thermal conductivity, which causes hot exhaust gas to be transferred to the surrounding parts (lower body and fuel tank) in the form of convection, radiation, and conduction, causing thermal damage. In spite of the application of stainless steel material, external corrosion occurs due to high temperature environment by exhaust gas along with corrosion-promoting materials such as salt water such as seawater or snow removing material used in winter, and through corrosion caused by internal condensate There is a problem that the engine exhaust noise is exposed as it is lost the silencer function.

Accordingly, in order to solve the problems of the conventional main muffler as described above, a plastic main muffler has been proposed to which the case 1 of the plastic material is applied (see FIG. 3). It is composed of sound-absorbing structure that is used to reduce noise of high frequency, but low frequency booming sound deteriorates and cannot be applied to mass production. In particular, noise tuning corresponding to engine frequency (Hz) or engine rpm also has a limited problem. In addition, since a large amount of expensive glass fibers are used as a heat insulating material and a sound absorbing material, there is a fear of causing problems such as deterioration of assembly properties and environmental pollution, and there are disadvantages in mass production applications.

In addition, the conventional plastic main muffler has a problem that the possibility of melting when running after the actual product production due to the structure in which the exhaust gas is in direct contact with the plastic case.

The present invention has been invented to solve the above problems, to prevent thermal damage of the peripheral parts by the high temperature exhaust gas, to prevent loss of function due to external corrosion, and to improve fuel efficiency through light weight, noise It is an object to provide a tunable automotive exhaust system muffler.

In order to achieve the above object, the present invention, the outer case of the plastic material disposed in the outermost (outer box), the intermediate insulation layer disposed inside the case outer layer and containing an airgel material and the stainless steel disposed inside the intermediate insulation layer Provided is a vehicle exhaust system muffler comprising a hollow case of a triple material formed by stacking a case inner layer of a steel material.

Preferably, the intermediate insulation layer is made of a non-woven fabric impregnated with an airgel, characterized in that formed in a thickness of 1 ~ 20 mm according to the temperature environment by the exhaust gas.

In addition, the case outer layer is made of a material in which the reinforcing material is further mixed with the plastic material, characterized in that the composition consisting of 30 to 95% by weight of the plastic material and 5 to 70% by weight of the reinforcing material.

And, the reinforcing material is characterized in that the ratio of the length and diameter of 30: 1 or more.

In addition, the case may include first and second baffles for partitioning an internal space into first, second and third chambers, and the front side of the case may be supported by the first and second baffles and be supported by the first and second baffles. An exhaust gas input pipe passing through the chamber to the third chamber and an exhaust gas output pipe supported by the second baffle and drawn out to the rear side of the case through the second and third chambers are installed.

Exhaust system muffler for automobile according to the present invention, by using a high heat-resistant plastic material and a high-temperature insulation airgel material in the case it is possible to reduce the weight and volume of the components, thereby improving fuel economy and assembly and improved design freedom of the peripheral parts The effect of (easy layout) can be obtained.

In addition, the muffler of the present invention can prevent the thermal damage of the peripheral parts by the high temperature exhaust gas, can prevent the functional loss due to external corrosion, and from the low frequency to high frequency radiation noise by the exhaust gas through noise tuning Can be effectively reduced.

1 shows a muffler mounted on an exhaust line of an automobile
Figure 2 is a block diagram showing a cross-sectional structure of the exhaust system muffler for automobiles according to an embodiment of the present invention
3 is a cross-sectional view showing a vehicle exhaust system muffler having a conventional plastic case.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention relates to a vehicle exhaust system muffler mounted on an exhaust line of a vehicle to reduce exhaust noise of an engine, and in particular, a muffler case made of a triple material capable of improving fuel efficiency and reducing thermal damage of peripheral components through weight reduction. It is characterized by an internal structure capable of noise tuning.

Referring to FIG. 2, an automobile muffler according to an embodiment of the present invention is disposed inside the case outer layer 11 and the case outer layer 11 made of a plastic material disposed at an outermost side, and an airgel material is used. The hollow case 10 of the triple material formed by stacking the (included) intermediate insulation layer 12 and a case inner layer 13 of a stainless steel case disposed inside the intermediate insulation layer 12 is laminated. It is configured to include, the case inner layer 13 is applied to the noise tuning structure of the same extension / resonance method as the existing muffler.

Specifically, the case outer layer 11 is manufactured in a substantially box shape using a high heat resistance thermosetting or thermoplastic plastic material, and prevents corrosion by a high temperature environment of the corrosion promoting material and exhaust gas and reduces the weight due to the characteristics of the plastic material. Can be provided.

The case outer layer 11 is formed by general injection molding or press molding, and is made of polypropylene, polyethylene, polyamide, polyphenylene sulfide, polybutylene tereph There is no limitation of the materials used such as rallate (Polybutylene Terephthalate), it is possible to select and apply a material in the range that does not cause thermal damage depending on the thickness and thermal insulation temperature of the intermediate insulation layer (12).

In addition, the case outer layer 11 is preferably formed by containing a reinforcing material to ensure noise reduction performance and component rigidity.

Specifically, the case outer layer 11 may be molded of a material in which a reinforcing material is additionally mixed in a plastic material, and is preferably molded in a composition in which 30 to 95% by weight of the plastic material and 5 to 70% by weight of the reinforcing material are mixed.

The reinforcing material is not limited to materials such as glass fiber, mineral fiber, bio fiber, carbon fiber, nano clay, etc., the length and diameter ratio of 30: 1 or more, that is, the length of the reinforcing material is 30 times or more of the diameter It can be used and manufactured by various methods such as general injection molding and press molding.

The reinforcing material may vary in composition within the above range depending on the temperature environment due to the exhaust gas, if less than 5% by weight of the material may be easily melted or broken due to lack of heat resistance, strength, rigidity, etc., 70% by weight In case of exceeding the injection molding or press moldability during product manufacturing and brittleness is increased, it is not preferable because it can be easily damaged by external impact.

Meanwhile, as shown in FIG. 2, the intermediate insulation layer 12 is manufactured in a substantially box shape to be stacked on the inner wall surface of the case outer layer 11, and has a thickness of 1 to 20 mm depending on the temperature environment caused by the exhaust gas. It may be appropriately formed.

The intermediate insulation layer 12 is formed using a non-woven fabric impregnated and attached with a nano-sized airgel in order to improve sound absorption and high temperature thermal insulation effects.

In general, aerogels have a high surface area, porosity, and low density by allowing the wet gel prepared by the sol-gel reaction to dry without shrinkage in supercritical conditions without a gas-liquid interface to maintain the pore structure of the gel. As a substance, it has a structure in which air is trapped about 90 to 99.8% due to the intertwined microfibers of ten thousandths of the thickness of hair, in particular, 40 times of thermal insulation effect of glass fiber and 2 times lower thermal conductivity of polymer foam material. Has a degree.

In the embodiment of the present invention, the intermediate insulation layer 12 is impregnated with nano-sized silica airgel on the nonwoven fabric, and then dried under supercritical carbon dioxide conditions to form an aerogel in which the aerogel is contained (exists) inside the nonwoven fabric. It is manufactured and constructed using impregnated nonwovens.

In addition, the case inner layer 13 is formed in a substantially box shape to be stacked on an inner wall surface of the intermediate insulation layer 12 using a stainless steel material.

On the other hand, the muffler for automobile according to the present invention has an internal structure capable of noise tuning in order to reduce the radiation noise in the high frequency as well as the low frequency region, the same expansion / resonance noise tuning of the muffler having a conventional stainless steel case Apply the structure.

Accordingly, according to the present invention, the case 10 made of a triple material made of plastic, aerogel-impregnated nonwoven fabric, and stainless steel material may include: a first partitioning an inner space into first, second, and third chambers 21, 22, and 23; And the second baffles 31 and 32 and the front side of the case 10 and are supported by the first and second baffles 31 and 32 and pass through the first and second chambers 21 and 22. A case through (through) the exhaust gas input pipe (15) leading to the third chamber (23) and the second baffle (32) and through the second and third chambers (22, 23) An exhaust gas output pipe 17 drawn out to the rear side of the 10 is provided.

In addition, the second baffle 32 or the first and second baffles 31 and 32 move the exhaust gas introduced into the case 10 (flows from the exhaust gas input pipe to the exhaust gas output pipe) and At least one perforation hole 34 is formed to increase the noise reduction effect.

Specifically, the first and second baffles 31 and 32 are spaced apart from each other in the inner space of the case 10, and the first and second baffles 31, 32 are sequentially disposed from the front to the rear toward the rear. The three chambers 21, 22, and 23 are partitioned, respectively.

The exhaust gas input pipe 15 serves to inject the exhaust gas discharged from the engine through the exhaust line into the inner space of the case 10, and the inner space of the case 10 at the front side of the case 10. It is installed to be drawn in and the front end is supported to protrude to the front side of the case (10).

The exhaust gas input pipe 15 penetrates through the first chamber 21 in the inner space of the case 10 and penetrates through the second chamber 22 while being supported by the first baffle 30. It is supported by the two baffles 50 and installed to develop up to the third chamber 23.

The exhaust gas output pipe 17 is for discharging the exhaust gas introduced into the case 10 to the outside and is supported by the second baffle 32 in the inner space of the case 10. The second and third chambers 22 and 23 are installed to be drawn out to the rear side of the case 10.

That is, the exhaust gas output pipe 17 has a front end supported by the second baffle 32 through the second chamber 22, and then rear end of the exhaust gas output pipe 17 through the third chamber 23 toward the rear side of the case 10. It is installed to protrude.

As described above, the muffler according to the present invention has a structure in which an internal space is divided into a plurality of chambers 21, 22, and 23 through a plurality of baffles 31 and 32 to increase the attenuation effect of exhaust noise. In the course of the passage, exhaust noise is gradually attenuated by interference of sound waves, a decrease in pressure fluctuations, and a decrease in exhaust temperature.

In the noise tuning structure as described above, the first and second baffles 31 and 32 may be disposed at an optimal position with respect to the case 10 to effectively reduce radiation noise by exhaust gas.

In addition, in order to optimize noise tuning, for example, by changing and adjusting the size and / or position of the pipes 15 and 17, or by changing and adjusting one or more of the position, number and size of the perforation holes 34, etc. The radiation noise by the gas can be effectively reduced.

In addition, in addition to the pipes 15 and 17, a pipe may be additionally installed so as not to sequentially pass through the chambers 21, 22, and 23, as described above, in any one of the chambers 21, 22, and 23. Noise can also be reduced by collecting exhaust gases to induce sound cancellation.

Therefore, the number of chambers 21, 22, 23, and pipes 15, 17 is not limited in order to efficiently reduce engine type, rpm, and Hz noise, and the flow of exhaust gas does not have to be sequentially progressed in one direction. .

In the embodiment of the present invention in adopting the conventional noise tuning structure as described above in the case 10, the airgel impregnated nonwoven material between the case outer layer 11 of the plastic material and the case inner layer 13 of the stainless steel material By constructing the intermediate heat insulating layer 12, the high temperature of the case inner layer 13 may be prevented from being transferred to the outside due to the high temperature exhaust gas, thereby preventing thermal damage of the outermost case 11 of the plastic case 11 and the peripheral parts. In this case, the case of the stainless steel material (corresponding to the inner layer of the case in the present invention), which was composed of two layers in the existing muffler, may be configured to be reduced to one layer, and may also be configured in two or more layers as necessary.

In the present invention, the noise tuning structure configured inside the case is not limited to the noise tuning structure described above, and may be variously modified by applying a known noise tuning structure.

The muffler according to the present invention can be significantly reduced in volume (or component size) by the configuration as described above, and can reduce exhaust noise from low frequency to high frequency through the existing expansion / resonance noise tuning structure. do.

In particular, it is possible to reduce the noise of the low-frequency booming sound by noise tuning for each frequency domain / engine rpm, it is possible to improve the discharge airflow sound in the high frequency region of 600Hz or more.

In general, the swelling of the muffler parts may be slightly deteriorated according to the volume reduction of the muffler component. However, in the present invention, the noise of the muffler is reduced by applying the casing 10 of the triple material, so that the overall noise reduction performance is reduced. Equivalent or increased relative to

In addition, by providing the intermediate insulation layer 12 of the nonwoven fabric type containing the airgel as the heat insulating material of the present invention, the same thickness as that of urethane foam or glass fiber, which is generally used, has excellent heat insulating properties, and in the same heat insulating performance The thickness of the insulation (intermediate insulation layer) can be reduced by one third, and the volume reduction improves the assemblability and the design freedom of the peripheral parts.

In addition, since the surface temperature of the muffler due to the exhaust gas in the exhaust system reaches up to 400 ℃, the application of organic insulating material is limited, and most of the inorganic insulating material such as glass fiber is being applied, but in the present invention, an airgel impregnated nonwoven fabric is used. By using the heat insulating material because the heat resistance temperature exceeds 600 ℃ it is possible to prevent the heat insulating material (that is, the intermediate insulation layer) to be melted or degraded by the exhaust gas temperature.

In addition, as the heat resistance is improved, it is also possible to prevent external corrosion of the case 10 through self-rusting.

On the other hand, the evaluation test was carried out as follows for the muffler according to the present invention.

1. Noise performance evaluation

A muffler prototype (A) having a casing of a triple material according to the present invention was manufactured using a material of PA6 + GF35% (which is a mixed material of polyamide 6 and glass fiber) in a thermoplastic resin, and was compared with the prior art as a comparative product. Thus, a muffler prototype (B) having a stainless steel case was produced.

As a result of comparing and evaluating the actual vehicle noise performance by making the same volume to exclude the noise performance difference due to the volume difference with respect to A and B, the radiation noise of A was about 2 ~ 3dBA in the area of 3000 ~ 4000RPM compared to B. It was measured low, even in the high-speed booming noise area of more than 3000RPM measured about 7 ~ 10dBC low, it could be confirmed that the muffler according to the present invention improves the noise performance compared to the existing muffler.

2. Back pressure rating

As a result of measuring and evaluating the exhaust pressure resistance of the muffler prototype according to the present invention manufactured with 17 L compared to the muffler having a stainless steel case of 21 L which is an existing mass production product, the muffler prototype according to the present invention is 32.3 kPa while the existing mass product is 35.8 kPa. It was confirmed that it was reduced to kPa.

When the exhaust pressure is lowered, the engine output is improved, thereby improving fuel efficiency.

3. Drainage Evaluation

The drainage evaluation was conducted to confirm the corrosion protection performance of the internal condensate.

After a certain amount of water was injected into the case of the muffler prototype according to the present invention, the engine was started and the residual amount was measured after 5 minutes. As a result, the possibility of condensation was very low.

4. Pipe connection endurance test

Deformation was measured within 6% of the exhaust gas input pipe and exhaust gas output pipe of the muffler prototype according to the present invention by measuring 0.5 to 30 Hz for 300 seconds. Since it is 1/3 level of damage standard, it was confirmed that the durability is excellent.

10: Case
11: case outer layer
12: middle insulation layer
13: case inner layer
15: exhaust gas input pipe
17: exhaust gas output pipe
21: first chamber
22: second chamber
23: third chamber
31: the first baffle
32: second baffle
34: perforation hole

Claims (7)

A case outer layer made of a plastic material disposed at the outermost part, an intermediate insulation layer disposed inside the case outer layer and containing an airgel material, and a case inner layer made of a stainless steel material disposed inside the intermediate insulation layer are laminated. And a hollow case of a triple material formed and
The intermediate insulation layer is impregnated and attached to a non-woven fabric of a nano-sized airgel, the exhaust system muffler for automobiles, characterized in that made of an airgel impregnated nonwoven fabric containing the airgel inside the nonwoven fabric.
delete The method according to claim 1,
The intermediate insulation layer is a vehicle exhaust system muffler, characterized in that formed in a thickness of 1 ~ 20 mm according to the temperature environment by the exhaust gas.
The method according to claim 1,
The case outer layer is an automobile exhaust system muffler, characterized in that made of a material in which a reinforcement is further mixed with a plastic material.
The method according to claim 1,
The case outer layer is a vehicle exhaust system muffler, characterized in that made of a composition of 30 to 95% by weight of the plastic material and 5 to 70% by weight of the reinforcing material.
The method according to claim 5,
The reinforcing material is a vehicle exhaust system muffler, characterized in that the ratio of the length and diameter of 30: 1 or more.
The method according to claim 1,
The case includes first and second baffles that divide an interior space into first, second and third chambers, and are introduced into the front side of the case and supported by the first and second baffles and define the first and second chambers. And an exhaust gas input pipe leading to the third chamber and an exhaust gas output pipe supported by the second baffle and drawn out to the rear side of the case through the second and third chambers.

Images