Patent Publication Number: US-11661871-B2

Title: Muffler for vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2019-0143687, filed on Nov. 11, 2019, the entire contents of which are incorporated herein by reference. 
     FIELD 
     The present disclosure relates to a muffler for a vehicle. 
     BACKGROUND 
     The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
     A muffler for a vehicle receives exhaust gases discharged from an internal combustion engine or a diesel engine for the purpose of reducing noise produced by the exhaust gas flow. In general, the muffler includes a muffler shell, a plurality of baffles disposed within the muffler shell, and a plurality of pipes mounted between adjacent baffles. The interior space of the muffler shell may be divided into a plurality of chambers by the plurality of baffles, and the plurality of pipes may pass through adjacent baffles to connect between adjacent chambers. A plurality of micro holes may be formed in a wall of each pipe to attenuate sound waves and reduce noise level. 
     In order to reduce the exhaust noise, a variable valve may be mounted on any one of the plurality of baffles. The variable valve includes a valve body having an opening through which the exhaust gas passes, a valve plate pivotally mounted on the valve body to open and close the opening of the valve body, and a torsion spring elastically supporting the valve plate. When the pressure of the exhaust gas is greater than a spring force of the torsion spring, the valve plate may be spaced apart from the valve body. When the pressure of the exhaust gas is less than the spring force of the torsion spring, the valve plate may be brought into contact with the valve body by the elastic force of the torsion spring. When the pressure of the exhaust gas is less than the spring force of the torsion spring (when the pressure of the exhaust gas is relatively low), the torsion spring may serve as a biasing element applying the spring force (biasing force) to bias the valve plate toward a closed position. 
     In a variable valve according to the related art, as the pressure of the exhaust gas varies, the valve plate is spaced apart from or is brought into contact with the valve body to open and close the opening of the valve body. Accordingly, the valve plate moves in the same direction as a direction of the exhaust gas flow. When the valve plate opens and closes the opening of the valve body, noise due to shaking or vibrations of the valve plate itself and noise due to a contact or impact between the valve plate and the valve body may be produced. In order to prevent such noises, a shock absorbing material such as a metal mesh may be interposed between the valve plate and the valve body. However, the assembly of an additional component such as the shock absorbing material increases manufacturing cost and weight. 
     By considering corrosion resistance, oxidation resistance, etc. for the torsion spring, which is a biasing element used in the related art variable valve, an expensive material such as INCONEL is applied. The torsion spring has a larger size than a coil spring, and the manufacturing thereof is relatively difficult, and thus the manufacturing cost and weight are relatively increased. 
     The above information described in this background section is provided to assist in understanding the background of the inventive concept, and may include any technical concept which is not considered as the prior art that is already known to those skilled in the art. 
     SUMMARY 
     The present disclosure has been made to solve the above-mentioned problems occurring in the prior art while advantages achieved by the prior art are maintained intact. 
     An aspect of the present disclosure provides a muffler for a vehicle, capable of minimizing or preventing various noises produced by the opening and closing of a variable valve. 
     According to an aspect of the present disclosure, a muffler for a vehicle may include: a muffler shell; a baffle disposed within the muffler shell, and having a first opening and a second opening, which allow an exhaust gas to pass therethrough; and a variable valve mounted on the baffle. In particular, the variable valve may include: a valve plate rotatably mounted to open and close the first opening of the baffle; a valve aim connected to the valve plate; and a valve actuator configured to move the valve arm by variations in pressure of the exhaust gas. The valve plate may be capable of rotating in a plane parallel to a plane of the baffle. 
     In one form, the valve plate may be rotatably mounted on the baffle through a shaft to maintain a contact with a surface of the baffle. 
     In another form, the valve actuator may include: an actuator housing having a receiving space which receives the exhaust gas through the second opening, and the receiving space of the actuator housing may directly communicate with the second opening of the baffle. 
     In other form, the valve plate may have a lug extending from an outer peripheral edge thereof, and the lug may be rotatably mounted on the baffle through the shaft. 
     In some forms of the present disclosure, the valve arm may be moved by the pressure of the exhaust gas received in the receiving space of the actuator housing. The lug may have a guide projection protruding in a direction away from the baffle, and the valve arm may have a guide recess by which a movement of the guide projection is guided. As the valve arm moves, the guide projection of the lug may be guided along the guide recess of the valve arm so that the valve plate may rotate. 
     In some forms of the present disclosure, the actuator housing may have a guide opening by which a movement of the valve arm is guided, and edges of the actuator housing may be coupled to the baffle by welding all around. 
     In some forms of the present disclosure, the valve arm may include a disc located within the receiving space of the actuator housing, and the disc may have a contact surface with which the exhaust gas received in the receiving space of the actuator housing directly comes into contact. 
     In one form, the disc may have a shape and a size conforming to the receiving space of the actuator housing. 
     The contact surface of the disc may be perpendicular to a longitudinal axis of the valve arm. 
     The valve actuator may include a spring interposed between an inner surface of the actuator housing and the disc. 
     Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which: 
         FIG.  1    illustrates a perspective view of a muffler for a vehicle according to an exemplary form of the present disclosure; 
         FIG.  2    illustrates an enlarged view of portion A of  FIG.  1   ; 
         FIG.  3    illustrates a state in which a valve plate opens a first opening of a baffle, which is viewed from a direction indicated by arrow B of  FIG.  2   ; 
         FIG.  4    illustrates a state in which a valve plate closes a first opening of a baffle; 
         FIG.  5    illustrates a perspective view of a valve plate in a muffler for a vehicle according to an exemplary form of the present disclosure; and 
         FIG.  6    illustrates a perspective view of a valve arm in a muffler for a vehicle according to an exemplary form of the present disclosure. 
     
    
    
     The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
     DETAILED DESCRIPTION 
     The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. 
     Hereinafter, exemplary forms of the present disclosure will be described in detail with reference to the accompanying drawings. In addition, a detailed description of well-known techniques associated with the present disclosure will be ruled out in order not to unnecessarily obscure the gist of the present disclosure. 
     Terms such as first, second, A, B, (a), and (b) may be used to describe the elements in exemplary forms of the present disclosure. These terms are only used to distinguish one element from another element, and the intrinsic features, sequence or order, and the like of the corresponding elements are not limited by the terms. Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meanings as those generally understood by those with ordinary knowledge in the field of art to which the present disclosure belongs. Such terms as those defined in a generally used dictionary are to be interpreted as having meanings equal to the contextual meanings in the relevant field of art, and are not to be interpreted as having ideal or excessively formal meanings unless clearly defined as having such in the present application. 
     Referring to  FIG.  1   , a muffler  10  for a vehicle, according to an exemplary form of the present disclosure, may include: a muffler shell  11 , a plurality of baffles  12 ,  13 , and  14  disposed within the muffler shell  11 , and a plurality of pipes  15 ,  16 , and  17  mounted between adjacent baffles  12 ,  13 , and  14 . 
     The interior space of the muffler shell  11  may be divided into a plurality of chambers  11   a,    11   b ,  11   c,  and  11   d  by the plurality of baffles  12 ,  13 , and  14 , and the plurality of pipes  15 ,  16 , and  17  may pass through adjacent baffles to connect between adjacent chambers. A plurality of micro holes may be formed in a wall of each pipe, thereby attenuating sound waves and reducing noise level. 
     The muffler  10  for a vehicle, may include a variable valve  20  mounted on at least one baffle  12  of the plurality of baffles  12 ,  13 , and  14 . The baffle  12  may have a first opening  31  and a second opening  32  that allow an exhaust gas to pass therethrough. The first opening  31  may be opened and closed by the variable valve  20  depending on variations in pressure of the exhaust gas. 
     Referring to  FIG.  2   , the variable valve  20  may include a valve plate  21  opening and closing the first opening  31  of the baffle  12 , a valve arm  22  connected to the valve plate  21 , and a valve actuator  25  moving the valve arm  22  linearly by the variations in the pressure of the exhaust gas. 
     The valve plate  21  may be rotatably mounted to be adjacent to the first opening  31  of the baffle  12  through a shaft  24 . A diameter of the valve plate  21  may be greater than a diameter of the first opening  31 , and an axis of the shaft  24  may be perpendicular to the baffle  12 . As the valve plate  21  rotates around the shaft  24 , the valve plate  21  may open and close the first opening  31 . Specifically, the valve plate  21  may rotate in a first rotation direction R 1  or a second rotation direction R 2 . The first rotation direction R 1  refers to a rotation direction in which the valve plate  21  opens the first opening  31 , and the second rotation direction R 2  refers to a rotation direction in which the valve plate  21  closes the first opening  31 . 
     In particular, the valve plate  21  may be mounted on the baffle  12  by the shaft  24  to slidably rotate on a surface of the baffle  12 . Specifically, the valve plate  21  may be rotatably mounted to the baffle  12  by the shaft  24  so that the valve plate  21  may maintain a contact with the baffle  12  when the valve plate  21  rotates (that is, the first opening  31  of the baffle  12  is opened and closed). In particular, the valve plate  21  may be capable of rotating in a plane parallel to a plane of the baffle  12 . Thus, even when the valve plate  21  is slightly spaced apart from the baffle  12 , shaking or vibrations of the valve plate itself may be prevented. 
     The valve plate  21  may have a lug  23  radially extending outwards from an outer peripheral edge thereof, and the lug  23  may be rotatably mounted on the baffle  12  through the shaft  24 . A guide projection  28  may protrude from a free end of the lug  23  in a direction away from the baffle  12 . An axis of the guide projection  28  may be perpendicular to a longitudinal axis of the lug  23 . For example, the axis of the guide projection  28  may be parallel to the axis of the shaft  24 . 
     The valve arm  22  may have a shape of a bar having a predetermined length. The valve arm  22  may have a first end portion connected to the valve plate  21 , and a second end portion  42  connected to the valve actuator  25 . The valve arm  22  may be linearly moved by the valve actuator  25 . Specifically, the valve arm  22  may move in a first direction F 1  or a second direction F 2 . The first direction F 1  refers to a direction in which the first end portion  41  of the valve arm  22  is away from the valve actuator  25 , and the second direction F 2  refers to a direction in which the first end portion  41  of the valve arm  22  is close to the valve actuator  25 . 
     The valve arm  22  may have a guide recess  45  by which a movement of the guide projection  28  of the valve plate  21  is guided. 
     For example, as illustrated in  FIGS.  2  to  4 , and  6   , the valve arm  22  may have two fingers  43  and  44  extending from the first end portion  41  toward the valve plate  21 , and the guide recess  45  defined by the fingers  43  and  44 . As the guide recess  45  is defined by the two fingers  43  and  44 , it may be a slot of which one end is open (that is, an end open slot). As the two fingers  43  and  44  are spaced apart from each other in a longitudinal direction of the valve arm  22 , the guide recess  45  may be defined by the fingers  43  and  44 . 
     A length of the guide recess  45  may be greater than a diameter of the guide projection  28  so that the guide projection  28  of the valve plate  21  may be guided along the guide recess  45  of the valve arm  22 . Thus, the linear movement of the valve arm  22  may be converted into the rotational movement of the valve plate  21 . 
     As another example, the guide recess  45  may be an arc-shaped slot of which both ends are closed. The guide recess  45  may be formed in the first end portion  41  of the valve arm  22  or a portion of the valve arm  22  adjacent to the first end portion  41 . 
     Referring to  FIGS.  3 ,  4 , and  6   , the valve arm  22  may have a disc  46  attached to the second end portion  42 , and the disc  46  may have a contact surface  46   a  with which the exhaust gas passing through the second opening  32  directly comes into contact. The disc  46  may have a predetermined area such as a circular section, and the contact surface  46   a  of the disc  46  may be perpendicular to the longitudinal axis of the valve arm  22 , so that a contact area between the contact surface  46   a  of the disc  46  and the exhaust gas may be secured. Thus, the disc  46  may be sensitive to variations in the pressure of the exhaust gas, so that the pressure of the exhaust gas may be efficiently transmitted to the valve arm  22 . The valve actuator  25  may drive the valve arm  22  and the valve plate  21  using the pressure of the exhaust gas. 
     According to an exemplary form, the valve actuator  25  may include an actuator housing  26  coupled to the baffle  12  to surround the second opening  32  of the baffle  12 . The actuator housing  26  may have a space  26   a  receiving the exhaust gas which has passed through the second opening  32  of the baffle  12 . The valve aim  22  may be moved linearly by variations in the pressure of the exhaust gas received in the space  26   a  of the actuator housing  26 . 
     The actuator housing  26  may be coupled to the baffle  12  by welding and/or the like, and the receiving space  26   a  of the actuator housing  26  may directly communicate with the second opening  32  of the baffle  12 . The disc  46  of the valve arm  22  may be located within the receiving space  26   a  of the actuator housing  26 , and the contact surface  46   a  of the disc  46  may directly contact the exhaust gas which has passed through the second opening  32  of the baffle  12 . 
     According to an exemplary form, the disc  46  may have a shape and a size conforming to the receiving space  26   a  of the actuator housing  26 , so that the disc  46  and the valve aim  22  may be moved more easily by variations in the pressure of the exhaust gas received in the space  26   a.    
     The actuator housing  26  may have a guide opening  26   b,  and the guide opening  26   b  of the actuator housing  26  may guide the movement of the valve arm  22 . In particular, edges of the actuator housing  26  may be coupled to the baffle  12  by welding all around. Thus, the actuator housing  26  may be tightly sealed from the outside, except for the second opening  32  and the guide opening  26   b.    
     The valve actuator  25  may include a spring  27  interposed between an inner surface of the actuator housing  26  and the disc  46 . The spring  27  may be a coil spring disposed around the valve arm  22 , and an axis of the spring  27  may be aligned with an axis of the valve arm  22 . When the pressure of the exhaust gas is less than a spring force of the spring  27  (that is, the pressure of the exhaust gas is relatively low), the spring  27  may serve as a biasing element applying the spring force (biasing force) to bias the valve plate  21  toward a closed position. 
     Referring to  FIG.  3   , when the pressure of the exhaust gas received in the space  26   a  of the actuator housing  26  through the second opening  32  is greater than the spring force of the spring  27 , the exhaust gas received in the space  26   a  of the actuator housing  26  may push the contact surface  46   a  of the disc  46  of the valve arm  22  to allow the valve arm  22  to move to the first direction F 1 . As the guide projection  28  of the valve plate  21  moves along the guide recess  45  of the valve arm  22 , the valve plate  21  may rotate in the first rotation direction R 1 , and the valve plate  21  may open the first opening  31 . 
     Referring to  FIG.  4   , when the pressure of the exhaust gas received in the space  26   a  of the actuator housing  26  through the second opening  32  is less than the elastic force of the spring  27 , the elastic force of the spring  27  may overcome the pressure of the exhaust gas to allow the valve arm  22  to move to the second direction F 2 . As the guide projection  28  of the valve plate  21  moves along the guide recess  45  of the valve arm  22 , the valve plate  21  may rotate in the second rotation direction R 2 , and the valve plate  21  may close the first opening  31 . 
     As set forth above, according to exemplary forms of the present disclosure, the valve plate  21  may slidably rotate around the first opening  31  of the baffle  12  of the muffler  10 , thereby opening and closing the first opening  31  of the baffle  12 . Since the valve plate  21  and the baffle  12  are not spaced apart from each other, noise due to the shaking or vibrations of the valve plate itself, and noise due to an impact between the valve plate and the valve body may be prevented or minimized. 
     According to exemplary forms of the present disclosure, when the valve plate  21  opens and closes the first opening  31  of the baffle  12 , the valve plate  21  may maintain the contact with the baffle  12 , without the need of a shock absorbing material, and thus the weight and manufacturing cost may be reduced. 
     According to exemplary forms of the present disclosure, the spring  27  may be used as the biasing element which biases the valve plate  21  under the low pressure condition of the exhaust gas, and accordingly axial elasticity of the spring  27  may be used as a whole, so that driving stability and driving performance of the valve plate  21  may be secured. Meanwhile, according to the related art, a torsion spring may be used as the biasing element. On the other hand, according to exemplary forms of the present disclosure, the spring  27  may be used as the biasing element. Since the size of the spring is significantly reduced, the consumption of a material (for example, INCONEL) may be reduced, and thus the manufacturing cost and weight may be reduced. 
     Hereinabove, although the present disclosure has been described with reference to exemplary forms and the accompanying drawings, the present disclosure is not limited thereto, but may be variously modified and altered by those skilled in the art to which the present disclosure pertains without departing from the spirit and scope of the present disclosure.