Abstract:
A muffler for a vehicle is disposed in a channel for discharging exhaust gas from the engine. The muffler uniformly reduces all of a flow-induced noise, a high-frequency noise, and a low-frequency booming noise generated by the exhaust gas passing through the channel, and maximize effect of reducing the noises to keep the vehicle silent and comfortable.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority to Korean Patent Application Number 10-2009-0095504 filed Oct. 8, 2009, the entire contents of which application is incorporated herein for all purposes by this reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a muffler of a vehicle, in more detail, a technology about the structure of a muffler reducing noise produced by vehicles while passing exhaust gas discharged from the engine. 
         [0004]    2. Description of Related Art 
         [0005]    Internal combustion engines producing force for driving vehicles discharge high-temperature and high-pressure exhaust gas and the exhaust gas causes a loud noise in discharging as it is into the atmosphere. Therefore, a muffler is provided in the exhaust system of vehicles to discharge exhaust gas with a noise reduced in passing therethrough. 
         [0006]    The noise due to the exhaust gas includes a flow-induced noise, a high-frequency noise, and a low-frequency booming noise and theses noises should be uniformly reduced. Further, it is required to reduce the noises as much as possible to keep vehicle silent and comfortable. 
         [0007]    The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    Various aspects of the present invention are directed to provide a muffler for a vehicle disposed in a channel for discharging exhaust gas from the engine, uniformly reducing all of a flow-induced noise, a high-frequency noise, and a low-frequency booming noise generated by the exhaust gas passing through the channel, and maximize effect of reducing the noises to keep the vehicle silent and comfortable. 
         [0009]    An aspect of the present invention provides a muffler for a vehicle, comprising an outer barrel formed long in a hollow tubular shape, a first baffle, a second baffle, and a third baffle sequentially disposed in the outer barrel to divide the outer barrel into four chambers in the longitudinal direction, an inlet cap connected to one end of the outer pipe to define a first chamber between the first baffle and the inlet cap, an outlet cap connected to the other end of the outer pipe to define a fourth chamber between the third baffle with the outlet cap, an inlet pipe disposed sequentially through the inlet cap and the first baffle to the third baffle, an outlet pipe disposed sequentially through the first baffle to the third baffle and the outlet cap, an intermediate pipe disposed through first baffle and second baffle, and a sound-absorbing material filled in a second chamber between the first baffle and the second baffle. 
         [0010]    According to the present invention, it is possible to uniformly reduce all of a flow-induced noise, a high-frequency noise, and a low-frequency booming noise generated by the exhaust gas passing through the channel, and maximize effect of reducing the noises to keep the vehicle silent and comfortable, using a muffler for a vehicle disposed in a channel for discharging exhaust gas from the engine. 
         [0011]    The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a view showing the structure of an exemplary muffler for a vehicle according to the present invention. 
           [0013]      FIG. 2  is a view showing another muffler for a vehicle similar to that shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]    Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims. 
         [0015]    Referring to  FIG. 1 , various embodiments of the present invention may include an outer pipe  1  having a long, hollow tubular shape, a first baffle  3 , a second baffle  5 , and a third baffle  7  sequentially disposed in outer pipe  1  to divide outer pipe  1  into four chambers in the longitudinal direction, an inlet cap  11  connected to one end of outer pipe  1  to define a first chamber  9  between first baffle  3  and inlet cap  11 , an outlet cap  13  connected to the other end of outer pipe  1  to define a fourth chamber between third baffle  7  with outlet cap  13 , an inlet pipe  15  disposed sequentially through inlet cap  11  and first baffle  3  to third baffle  7 , an outlet pipe  17  disposed sequentially through first baffle  3  to third baffle  7  and outlet cap  13 , an intermediate pipe  19  disposed through first baffle  3  and second baffle  5 , and a sound-absorbing material  21  filled in a second chamber  23  between first baffle  3  and second baffle  5 . One will appreciate that pipe  1  is long in that extends substantially the length of the muffler. 
         [0016]    Sound-absorbing material  21  is made of glass wool. The inlet cap  11  is a member sealing the inlet of outer pipe  1 , with only inlet pipe  15  therethrough, and outlet cap  13  is a member sealing the outlet of outer pipe  1 , with only outer pipe  17  therethrough. 
         [0017]    A first communication hole  25  communicating with second chamber  23  is formed at the portion in second chamber  23  of inlet pipe  15  and a second communication hole  27  communicating with second chamber  23  is formed at the portion in second chamber  23  of outlet pipe  17 . 
         [0018]    Exhaust gas from the engine flows into inlet pipe  15  and of which the flow-induced noise is reduced by first communication hole  25  when it passes second chamber  23 . Further, in discharging outside the muffler through outlet pipe  17 , the flow-induced noise is reduced by second communication hole  27  when the exhaust gas passes second chamber  23 . 
         [0019]    At least one or more third holes  29  connecting first chamber  9  with second chamber  23  are formed in first baffle  3  and at least one or more fourth communication holes  33  connecting third chamber  31  between second baffle  5  and third baffle  7  with second chamber  23  are formed in second baffle  5 . 
         [0020]    Third communication hole  29  of first baffle  3  and fourth communication hole  33  of second baffle  5  reduces an unpleasant high-frequency noise at both sides. 
         [0021]    Assuming the total distance is the distance from inlet cap  11  to outlet cap  13 , second baffle  5  is positioned within ½ of the total distance from inlet cap  11 . 
         [0022]    Therefore, it is possible to ensure the space at the right side of second baffle  5 , which makes it possible to ensure a space for reducing a low-frequency noise. 
         [0023]    A fifth communication hole  35  communicating with third chamber  31  is formed at the portion in third chamber  31  of inlet pipe  15 , such that it effectively reduce a low-frequency booming noise in the large chamber ensured at the right side of second baffle  5 . 
         [0024]    That is, the noise is additionally reduce by reflection of a low-frequency noise while the exhaust gas uniformly flows by fifth communication hole  35 . 
         [0025]    At least one or more sixth communication holes  39  connecting third chamber  31  with a fourth chamber  37  is formed in third baffle  7 . Fourth chamber  37  is a space defined between third baffle  7  and outlet cap  13 . 
         [0026]    Therefore, the noise passing through sixth communication hole  39  of third baffle  7  and the noise passing through fifth communication hole  35  interfere with each other, such that the effect of reducing a noise is maximized. 
         [0027]    A seventh communication hole  41  communicating with second chamber  23  is formed at the portion in second chamber  23  of intermediate pipe  19 . 
         [0028]    Consequently, the exhaust gas flowing into the muffler flows inside through inlet pipe  15 , is uniformly discharged out of third chamber  31 , and turns and flows out along a large path through third baffle  7  and fourth chamber  37 , such that the noise is more effectively reduced by interference and reflection of the low-frequency noises. 
         [0029]    Further, the exhaust gas flows into third chamber  31  flows into first chamber  9  through intermediate pipe  19  and is discharged through outlet pipe  17 , such that performance of reducing a noise increases. 
         [0030]    On the other hand, another embodiment of the present invention is shown in  FIG. 2 , in which third communication hole  29  of first baffle  3 , fourth communication hole  33  of second baffle  5 , and sixth communication hole  39  of third baffle  7  are removed. All the third communication hole  29 , fourth communication hole  33 , and sixth communication hole  39  may be removed, however, other combinations of theses hole with some the holes removed may be possible. 
         [0031]    For convenience in explanation and accurate definition in the appended claims, the terms “inside” or “outside”, and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. 
         [0032]    The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.