Muffler for vehicle

A muffler for a vehicle may include a main muffler in front of a rear suspension when viewing from a front of the vehicle, a plurality of baffles dividing an interior of the main muffler into a plurality of chambers, an inlet pipe installed substantially at an center of one side of the main muffler and passing through the plurality of the baffles, a discharge pipe installed at a lower side of the other side of the main muffler and passing through the plurality of the baffles, wherein the discharge pipe exhausts an exhaust gas flowed in the inlet pipe to an exterior of the main muffler, an intermediate pipe in fluidic communication with an outlet port of the inlet pipe, and a variable valve selectively opened or closed in response to a back pressure of the exhaust gas from an outlet port of the intermediate pipe.

CROSS-REFERENCE(S) TO RELATED APPLICATIONS

The present application claims priority of Korean Patent Application Number 10-2012-0087688, filed on Aug. 10, 2012, the entire contents of which application is incorporated herein for all purposes by this reference.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to a muffler for a vehicle, and particularly to a muffler for a vehicle which makes it possible to minimize oscillation booming noises.

2. Description of Related Art

In order to reduce the noise from exhaust gas, a muffler is generally installed on an exhaust line installed to guide the exhaust gas to the rear side of the vehicle in an exhaust system configured to discharge the exhaust gas generating from the engine of a vehicle.

As shown inFIG. 1, a main muffler10of the conventional art is engaged at a rear side of a vehicle, the installation position of which is determined based on a limited lower structure of a vehicle. The installation position of the main muffler10inevitably becomes a rear side of a vehicle and is critical in an attempt to avoid any interference with a fuel tank and a suspension. Here, as the main muffler10is positioned at a rear side of the vehicle, the prevention of booming becomes hard, and the loss due to insertion is more worsened.

Given the above background, there is a need in the art for an improved main muffler.

SUMMARY OF INVENTION

Various aspects of the present invention are directed to provide a muffler for a vehicle which features in that a main muffler is installed in front of a rear suspension when viewing from the front side of a vehicle, thus minimizing an oscillation booming noise.

Various aspects of the present invention provide a muffler for a vehicle comprising a main muffler disposed in front of a rear suspension when viewing from a front of the vehicle, a plurality of baffles dividing an interior of the main muffler into a plurality of chambers, an inlet pipe installed substantially at an center of one side of the main muffler and passing through the plurality of the baffles, a discharge pipe installed at a lower side of the other side of the main muffler and passing through the plurality of the baffles, wherein the discharge pipe is provided for exhausting an exhaust gas flowed in the inlet pipe to an exterior of the main muffler, an intermediate pipe in fluidic communication with an outlet port of the inlet pipe, and a variable valve selectively opened or closed in response to a back pressure of the exhaust gas from an outlet port of the intermediate pipe.

The interior of the main muffler may include first, second, third, fourth and fifth chambers which are partitioned by means of first, second, third and fourth baffles. A first array of punched holes, a second array of punched holes and a third array of punched holes may be formed on an outer circumferential surface of the inlet pipe passing through the second chamber, the third chamber and the fourth chamber respectively, and a fourth array of punched holes and a fifth array of punched holes may be formed on an outer circumferential surface of the discharge pipe passing through the first chamber and the second chamber respectively.

The inlet pipe may be configured to pass through the first, second, third and fourth baffles, and the outlet port of the inlet pipe is positioned in the fifth chamber. The discharge pipe may be configured to pass through the first, second, third and fourth baffles, and an inlet port of the discharge pipe is positioned in the first chamber. The intermediate pipe may be positioned in the fourth chamber and pass through the third baffle and the fourth baffle, and may be in fluidic communication with the third chamber and the fifth chamber.

Various aspects of the present invention provide the variable valve that may open when the back pressure of the exhaust gas from the outlet port of the intermediate pipe exceeds a certain pressure level, thereby providing a fluidic communication between the second chamber and the third chamber. The variable valve may remain closed if the back pressure of the exhaust gas from the outlet port of the intermediate pipe is lower than a certain pressure level, thereby forcing an amount of the exhaust gas passing through the first array of punched holes of the inlet pipe and through the fifth array of punched holes of the discharge pipe and then discharged to the exterior of the main muffler.

In addition, glass wool may be filled in the fourth chamber through which the inlet pipe passes. A plurality of flow holes may be formed on the surfaces of the third baffle and the fourth baffle which are configured to partition the fourth chamber. A plurality of flow holes may be formed in the first baffle so that the exhaust gas passing through the variable valve by way of the third chamber can pass through the first chamber.

According to various aspects of the present invention, the main muffler is installed in front of a rear suspension when viewing from the front side of a vehicle, so the length of a shaft can be prolonged, thus increasing the volume and reducing booming noises.

DETAILED DESCRIPTION

FIG. 2is a view illustrating an exemplary muffler for a vehicle according to various embodiments of the present invention. As shown inFIG. 2, the muffler for a vehicle according to various embodiments of the present invention comprises a main muffler100configured to have a certain volume. The main muffler100has a distant portion generally configured to have an elliptical cross section and has a certain length prolonged in a direction that a vehicle drives. In various embodiments, when viewing from the front side of a vehicle, the main muffler100may be positioned in front of a rear suspension connected to the rear wheels of a vehicle for absorbing vibrations, the construction of which helps obtain more spaces as compared to the conventional main muffler. As the length of the shaft can be prolonged, larger volume can be obtained. For example, the volume of 33 liters can be obtained, which is greater than 27 liters in the conventional art.

FIG. 3is a cross sectional view illustrating an exemplary muffler for a vehicle according to various embodiments of the present invention. As shown inFIG. 3, a plurality of baffles such as baffles111,112,113,114are disposed at substantially regular intervals for the purpose of sectioning the interior of it into a plurality of chambers such as chambers101,102,103,104,105. The plurality of the baffles111,112,113,114include a first baffle111, a second baffle112, a third baffle113and a fourth baffle114. A first chamber101, a second camber102, a third chamber103and a fourth chamber104are respectively formed between the neighboring portions formed from the first baffler111, the second baffle112, the third baffle113and the fourth baffler114.

At one side of the main muffler100, for example, substantially at the center of one side of the main muffler100is disposed an inlet pipe120which passes from the first chamber101to the fifth chamber105. In other words, the inlet pipe120is arranged passing through the first baffle111, the second baffler112, the third baffler113and the fourth baffle115. Here, an inlet port121of the inlet pipe120communicates with an outer side of the main muffler100, and an outlet port122of the input pipe120is positioned at the fifth chamber105.

At the lower side of the other side of the main muffler100is arranged a discharge pipe130passing from the first chamber101to the fifth chamber105. The discharge pipe130is configured to pass the first baffle111, the second baffler112, the third baffle113and the fourth baffle114. Here, an inlet port of the discharge pipe130is positioned in the interior of the first chamber101, and an outlet port132of the discharge pipe130communicates with an outer side of the main muffler100.

In addition, an intermediate pipe140is prolonged from the inlet pipe120while communicating with the outlet port122through which exhaust gas is discharged. The intermediate pipe140is installed in the fourth chamber104while passing through the third baffle113and the fourth baffle114, so the third chamber103and the fifth chamber105come to communicate with each other. In various embodiments, glass wool (G) may be filled in the interior of the fourth chamber104. Since the main muffler100is disposed in front of the rear suspension when viewing from the front side of the vehicle, the temperature of the exhaust gas increases, and the flow speed/turbulent flow energy increases, so the flow-induced noises generate, and the high frequency is more worsened. In various embodiments of the present invention, glass wool (G) is filled in the interior of the fourth chamber104in order to improve the above mentioned problems. One would appreciate that other materials similar to glass wool may be used.

A plurality of flow holes such as flow holes113aand114amay be formed on the whole portions of the third baffle113and the fourth baffle114. The formation of the plurality of the flow holes113aand114amay help effectively eliminate the high frequency noises.

At the second baffle112is disposed a valve150configured to transfer the exhaust gas from the outlet port142of the intermediate pipe140to the second chamber102. At a variable valve150is disposed a gate152which is configured to close during the idle operation of the vehicle and to open when the revolution of the engine increases or the back pressure in the interior of the main muffler100increases. As another example, at the variable valve150is provided an elastic member with an elastic modulus, with the aid of which the variable valve150can open or close depending on the back pressure if the revolution of the engine of the vehicle is lower or higher than a normal range, for example, a revolution of 2500 rpm.

On the outer circumferential surface of the inlet pipe120are formed a plurality of punched holes such as punched holes120a,120band120cwhich help change the flow of the exhaust gas in each section of the revolution of the engine: the first array of punched holes120aof the inlet pipe120passing through the second chamber102, the second array of punched holes120bof the inlet pipe120passing through the third chamber103, and the third array of punched holes120cof the inlet pipe120passing through the fourth chamber104. Here, the number of the punched holes each passing through a corresponding chamber may vary depending on results of the experiments or other factors.

On the outer circumferential surface of the discharge pipe130are formed punched through holes such as punched through holes130aand130b: the fourth array of punched holes130aof the discharge pipe130positioned in the first chamber101, and the fifth array of punched holes130bof the discharge pipe130passing through the second camber102.

The operations of the exemplary muffler for a vehicle according to various embodiments of the present invention will be described.

If the revolution of the engine of a vehicle belongs to a low load section, the exhaust gas is introduced by way of the inlet pipe120and moves toward the variable valve150by way of the inlet port141of the intermediate pipe140in the fifth chamber105. Here, due to the low pressure of the exhaust gas, the gate152of the variable valve150keeps closed, so a small amount or some amount of the exhaust gas is forced to pass through the first array of punched holes120aof the inlet pipe120in the second chamber102and to discharge to the outside by way of the fifth array of punched holes130bof the discharge pipe130. In addition, the first chamber101and the second chamber102are formed like a resonance chamber, the construction of which helps reduce the booming noises, such as the booming noises of 110 Hz.

If the revolution of the engine of a vehicle belongs to a high load section, the high pressure exhaust gas passes through the outlet port122of the inlet pipe120and reaches the variable valve150by way of the inlet port141of the intermediate pipe140. At this time, since an external force exceeding the elastic force is generated and applied due to the pressure of the exhaust gas within the elastic modulus of the elastic member of the variable valve150, the gate152is forced to open. Afterward, the exhaust gas flows into the first chamber101by way of the flow hole111aformed at a partial portion of the first baffle111and flows toward the discharge pipe130by way of the inlet port131of the discharge pipe130in the first chamber101and the fourth array of punched holes130aand then is discharged to the outside. At this time, due to the construction that the main muffler100is positioned in front of the rear suspension when viewing from the front side of the vehicle as compared to the conventional art, the temperature of the exhaust gas is high, and the flow speed/turbulent flow energy increases, the operations of which might worsen the flow-induced noises and the high frequency noises; however such noises are reduced while the exhaust gas passes through the glass wool G filled in the fourth chamber104and a plurality of the flow holes113aand114aformed on the whole surfaces of the third baffle113and the fourth baffle114.

For convenience in explanation and accurate definition in the appended claims, the terms “interior” or “exterior”, and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.