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TECHNICAL FIELD 
       [0001]    The present invention relates to a ventilation system for a bathroom, and particularly, to a ventilation system for a bathroom that uses a blower to forcedly discharge air out of the bathroom to refresh the inside the bathroom. 
       BACKGROUND ART 
       [0002]    In general, an apartment building, office building or other human life space has a bathroom(s). In the past, the bathroom was placed at a location isolated from the living space to treat the human excreta. However, a recent trend is towards the bathroom being housed inside the living space as the apartment is favored as a dwelling. 
         [0003]    Following such trend, the toilet and basin installed in the bathroom goes on evolving for more sanitation. Further, a change in function of the bathroom from a mere space to treat human waste to a multi-functional room for bathing and makeup led to people staying longer in the bathroom, and the waste treatment space is thus in the trend of being equipped with higher-class facilities. 
         [0004]    Meanwhile, an air exhausting facility mostly comes with the bathroom of an apartment house. The air exhausting facility is installed on a ceiling panel inside the bathroom, and a fan is provided on the top or a side of the facility for smooth exhaust. The air exhausting system draws the moisture or odor out of the bathroom. 
         [0005]    However, such air exhausting facility simply exhausts air from the bathroom and cannot respond to the satisfaction when the bathroom door remains closed, i.e., in the airtight bathroom. 
         [0006]    In other words, although for ventilation an air intake should be the same as the amount of air exhaust, the air intake in the door-closed state fails to reach the amount of air exhaust, thus rendering ventilation difficult. 
       SUMMARY 
     Objects 
       [0007]    The present invention has been designed to address the above issues, and an object of the present invention is to provide a bathroom ventilation system that has a bi-directional ventilation tube for externally exhausting internal air while simultaneously supplying external air to the bathroom, which enables quick ventilation in the bathroom and which discharges the internal air and odor from the bathroom through an internal air traveling tube, thus preventing odors. 
       Solution 
       [0008]    To achieve the above objects, according to the present invention, a ventilation system for a bathroom comprises: an external air traveling tube  100  provided at an upper side of a ceiling panel of the bathroom and having an air intake fan  150  that takes air in from an outside and moves the taken-in air to an inside of the bathroom; an internal air traveling tube  200  provided at the upper side of the ceiling panel of the bathroom and having an air exhausting fan  250  that draws air from the inside of the bathroom to the outside; and a bi-directional ventilation tube  300  provided at a ceiling of the bathroom, the bi-directional ventilation tube  300  including an air exhausting part  310  having a side connected with the external air traveling tube  100  and another side connected with the inside of the bathroom and an air intake part  320  having a side connected with the internal air traveling tube  200  and another side connected with the inside of the bathroom. 
         [0009]    The air intake part  320  is formed to pass through the inside of the air exhausting part  310  to be opened toward the bathroom, and wherein, a guiding plate  330  is provided at the other side of the air intake part  320 , which faces the bathroom, along a periphery thereof, the guiding plate  330  projected towards the ceiling of the bathroom. 
         [0010]    The ventilation system further comprises an intake adjusting member  400  provided at the other side of the air exhausting part  310 , which faces the bathroom, to be movable in a longitudinal direction of the air exhausting part  310  to adjust an air intake. 
         [0011]    The intake adjusting member  400  includes: 
         [0000]    a fixed part  410  provided at the other side of the air exhausting part  310 , the fixed part  410  including a threaded groove part  411  in a middle of the fixed part  410  and an opening  412  formed outside the threaded groove part  411  to connect the inside of the air exhausting part  310  with the inside of the bathroom; and
 
a moving part  420  including a bolt part  421  and a cover  422 , the bolt part  421  screw-connected to the nut part  411 , the cover  422  rotated to move up and down along the nut part  411  to open and close the opening  412 .
 
         [0012]    The internal air traveling tube  200  includes: a first exhaust pathway  210  provided at the upper side of the ceiling panel of the bathroom and having a side connected with the bi-directional ventilation tube  300 , wherein air in the bathroom is sucked through the first exhaust pathway  210 ; a second exhaust pathway  220  extended along the upper side of the ceiling panel of the bathroom to a side wall of the bathroom and having a side connected with a toilet  10  disposed in the bathroom, wherein air around the toilet  10  is sucked and flows through the second exhaust pathway  220 ; and a third exhaust pathway  230  provided at the upper side of the ceiling panel of the bathroom and connected with the first exhaust pathway  210  and the second exhaust pathway  220 , wherein the third exhaust pathway  230  is connected with the air exhausting fan  250  to exhaust the air inside the bathroom and the air around the toilet  10  to the outside. 
         [0013]    The third exhaust pathway  230  includes: a joining section  231  connected with the first exhaust pathway  210  and the second exhaust pathway  220 , wherein an internal cross-sectional area of the joining section  231  is larger than a sum of an internal cross-sectional area of the first exhaust pathway  210  and an internal cross-sectional area of the second exhaust pathway  220 ; a exhausting section  232  having a side connected with the joining section  231  and another side connected with the air exhausting fan  250 , wherein an internal cross-sectional area of the exhausting section  232  is larger than a sum of the internal cross-sectional area of the first exhaust pathway  210  and the internal cross-sectional area of the second exhaust pathway  220  and is smaller than the internal cross-sectional area of the joining section  231 ; an adjusting plate  240  provided in the joining section  231  to, depending on a difference in amount between the air sucked through the first exhaust pathway  210  and the air sucked through the second exhaust pathway  220 , shift in a direction towards one, through which a smaller amount of air is sucked, of the first exhaust pathway  210  and the second exhaust pathway  220 . 
         [0014]    The external air traveling tube  100  includes an air purifying filter  500  to rid the sucked external air of foreign substances and dust. 
       Effects 
       [0015]    The bathroom ventilation system according to the present invention, as described above, provides the following effects. 
         [0016]    The intake of air in the bathroom and supply of external air are simultaneously performed through the bi-directional ventilation tube  300 . Accordingly, even in the airtight state where the bathroom door stands closed, more loads are prevented from being applied to the air exhausting fan  250 , and air circulation is swiftly done. Therefore, the bathroom may remain at a pleasant atmosphere. 
         [0017]    Formation of the downwardly-inclined guiding plate  330  along the periphery of the air intake part  320  enables the air discharged from the air exhausting part  310  to flow evenly passing the walls of the bathroom, thus quickly removing the moisture of the walls of the bathroom. 
         [0018]    The intake adjusting member  400  is provided at a lower side of the air intake part  320  to move up and down. Accordingly, the user may adjust the amount of air exhausted from the inside of the bathroom and from around the toilet  10 , thus allowing for easier use. 
         [0019]    The internal air traveling tube  200  includes the second exhaust pathway  220  connected with the toilet  10 . Accordingly, the odors around the toilet  10  may be quickly drawn out through the toilet  10  without passing through the inside of the bathroom, thus minimizing germ proliferation. Therefore, the bathroom may remain clean. 
         [0020]    The adjusting plate  240  is provided in the third exhaust pathway  230  to be movable toward the first exhaust pathway  210  and the second exhaust pathway  220  depending on air intakes, thus reducing occurrence of a vortex in the joining section  231  while preventing the air sucked through the second exhaust pathway  220  from flowing back to the first exhaust pathway  210 . 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0021]      FIG. 1  is a view illustrating a side cross-sectional structure of a bathroom ventilation system according to an embodiment of the present invention. 
           [0022]      FIG. 2  is a perspective view illustrating a bi-directional ventilation tube  300  of a bathroom ventilation system according to an embodiment of the present invention. 
           [0023]      FIG. 3  is a view illustrating an operation state of an intake adjusting member  400  of a bathroom ventilation system according to an embodiment of the present invention. 
           [0024]      FIG. 4  is a perspective view illustrating a third exhaust pathway  230  of a bathroom ventilation system according to an embodiment of the present invention. 
           [0025]      FIG. 5  is an expanded view illustrating a side cross-sectional structure of a second exhaust pathway  220  and a toilet  10  of a bathroom ventilation system according to an embodiment of the present invention. 
       
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0026]      FIG. 1  is a view illustrating a side cross-sectional structure of a bathroom ventilation system according to an embodiment of the present invention.  FIG. 2  is a perspective view illustrating a bi-directional ventilation tube  300  of a bathroom ventilation system according to an embodiment of the present invention.  FIG. 3  is a view illustrating an operation state of an intake adjusting member  400  of a bathroom ventilation system according to an embodiment of the present invention.  FIG. 4  is a perspective view illustrating a third exhaust pathway  230  of a bathroom ventilation system according to an embodiment of the present invention.  FIG. 5  is an expanded view illustrating a side cross-sectional structure of a second exhaust pathway  220  and a toilet  10  of a bathroom ventilation system according to an embodiment of the present invention. 
         [0027]    As shown in  FIGS. 1 to 5 , according to an embodiment of the present invention, the bathroom ventilation system includes an external air traveling tube  100 , an internal air traveling tube  200 , a bi-directional ventilation tube  300 , an intake adjusting member  400 , and an air purifying filter  500 . 
         [0028]    The external air traveling tube  100  is shaped as a hollow tube including a pathway through which air may flow. The external air traveling tube  100  is provided at an upper side of a bathroom ceiling panel. The external air traveling tube  100  is connected with an air intake fan  150  that takes air in from the outside and moves the taken-in air to the inside of the bathroom. 
         [0029]    Here, the external air traveling tube  100  is preferably formed of a flexible hose for allowing the external air traveling tube  100  to be freely adjusted in shape and arrangement upon installation. The air intake fan  150  has the same structure as that of a typical blower and detailed description thereof is skipped. 
         [0030]    Further, the air purifying filter  500  to be described below is provided in a middle section of the external air traveling tube  100  to remove foreign substances or dust from the air taken in from the outside. 
         [0031]    Like the external air traveling tube  100 , the internal air traveling tube  200  is shaped as a hollow tube including a pathway through which air may flow. The internal air traveling tube  200  is provided at an upper side of the bathroom ceiling panel. The internal air traveling tube  200  is connected with an air exhausting fan  250  that draws air from the inside of the bathroom to the outside. 
         [0032]    Here, the internal air traveling tube  200  is preferably formed of a flexible hose for allowing the external air traveling tube  100  to be freely adjusted in shape and arrangement upon installation. The air exhausting fin  250  has the same structure as that of a typical blower and detailed description thereof is skipped. 
         [0033]    Further, the internal air traveling tube  200  sucks the air in the bathroom through the bathroom ceiling and is connected with the toilet  10  installed in the bathroom to suck odors around the toilet  10  and to draw the odors to the outside. 
         [0034]    Specifically, the internal air traveling tube  200  includes a first exhaust pathway  210 , a second exhaust pathway  220 , and a third exhaust pathway  230 . 
         [0035]    As shown in  FIG. 1 , the first exhaust pathway  210  is mounted at an upper side of the ceiling panel of the bathroom, and its side, i.e., left side, is connected with the bi-directional ventilation tube  300 , and the other side, i.e., right side, is connected with the third exhaust pathway  230  to be described below. 
         [0036]    The air in the bathroom is sucked and is rendered to flow the third exhaust pathway  230  through the first exhaust pathway  210 . 
         [0037]    The second exhaust pathway  220  is extended along the upper side of the ceiling panel of the bathroom and is bent to a right side wall of the bathroom. A side, i.e., a lower end, of the second exhaust pathway  220  is connected with the toilet  10  provided in the bathroom, and another side, i.e., an upper end, thereof is connected with the third exhaust pathway  230  to be described below. 
         [0038]    The air around the toilet  10  is sucked and is rendered to flow the third exhaust pathway  230  through the second exhaust pathway  220 . 
         [0039]    Here, as shown in  FIGS. 1 and 5 , the toilet  10  is formed of a toilet seat  10 . Specifically, the toilet  10  includes a main body  11  having a hollow  11   a  and a water tank  12  including an overflow tube  12   a  communicating with the hollow  11   a.    
         [0040]    A coupling structure  13  is provided in the toilet  10 . The coupling structure  13  has an end mounted on an upper end of the overflow tube  12   a  and another end connected with the second exhaust pathway  220 . 
         [0041]    The coupling structure  13  is shaped as a hollow tube. A middle part of the coupling structure  13  is bent to about 90 degrees. The coupling structure  13  is formed of rubber for easy angling upon installation. 
         [0042]    The above configuration enables the odors created in the hollow  11   a  to be sucked to the second exhaust pathway  220  through the overflow tube  12   a  and the coupling structure  13  and to be exhausted to the outside. 
         [0043]    Of course, the toilet  10  may also be configured to form a separate pathway communicating with the hollow  11   a  in the main body  11  to be connected with the second exhaust pathway  220  without passing through the overflow tube  12   a.    
         [0044]    As such, the internal air traveling tube  200  includes the second exhaust pathway  220  connected with the toilet  10 . Accordingly, the odors around the toilet  10  may be quickly drawn out through the toilet  10  without passing through the inside of the bathroom, thus minimizing germ proliferation. Therefore, the bathroom may remain clean. 
         [0045]    Meanwhile, the third exhaust pathway  230  is provided at an upper side of the ceiling panel of the bathroom and is connected with the first exhaust pathway  210  and the second exhaust pathway  220 . The air inside the bathroom, together with the air around the toilet  10 , is exhausted through the third exhaust pathway  230 . 
         [0046]    The third exhaust pathway  230 , as shown in  FIG. 4 , is divided into a joining section  231  and an exhausting section  232 . 
         [0047]    Left and right sides of the joining section  231  are connected with the first exhaust pathway  210  and the second exhaust pathway  220 , respectively. The internal cross-sectional area of the joining section  231  is formed to be larger than the sum of the internal cross-sectional area of the first exhaust pathway  210  and the internal cross-sectional area of the second exhaust pathway  220 . 
         [0048]    The exhausting section  232  is disposed at an upper side of the joining section  231 . A side, i.e., a lower side, of the exhausting section  232  is connected with the joining section  231 , and another side, i.e., an upper side, thereof is connected with the air exhausting fan  250 . The internal cross-sectional area of the exhausting section  232  is formed to be the same as the sum of the internal cross-sectional area of the first exhaust pathway  210  and the internal cross-sectional area of the second exhaust pathway  220 . 
         [0049]    Meanwhile, the joining section  231  has an adjusting plate  240  that may shift towards the first exhaust pathway  210  and the second exhaust pathway  220 . 
         [0050]    The adjusting plate  240  is disposed midway between the first exhaust pathway  210  and the second exhaust pathway  220 , i.e., at a middle of the exhausting section  232 . The adjusting plate  240  is shaped as a rectangular plate. 
         [0051]    The adjusting plate  240  prevents a vortex that may occur when the air sucked through the first exhaust pathway  210  and the air sucked through the second exhaust pathway  220  meet each other in the joining section  231  and allows the air to be smoothly drawn out. 
         [0052]    Further, the adjusting plate  240  shifts depending on a difference in amount between the air sucked through the first exhaust pathway  210  and the air sucked through the second exhaust pathway  220 . For example, the adjusting plate  240  moves in a direction in which a smaller amount of air is sucked. 
         [0053]    The amount of air sucked through the first exhaust pathway  210  may be varied by the intake adjusting member  400  to be described below. In this case, if the air intake through the first exhaust pathway  210  is smaller than the air intake through the second exhaust pathway  220 , the adjusting plate  240  shifts toward the first exhaust pathway  210 , and the inlet of the third exhaust pathway  230  communicating with the first exhaust pathway  210  is narrowed, and the inlet of the third exhaust pathway  230  communicating with the second exhaust pathway  220  is broadened. 
         [0054]    In case the adjusting plate  240  remains at a fixed position, even when the inlet of the intake adjusting member  400 , through which air is taken in is narrowed, the inlet of the third exhaust pathway  230  connected with the first exhaust pathway  210  remains the same area. Thus, the air pressure in the first exhaust pathway  210  is decreased while the air pressure in the second exhaust pathway  220  is increased. Hence, the air around the toilet  10 , which is sucked to the exhaust pathways, is rendered to flow back to the first exhaust pathway  210 . Accordingly, the adjusting plate  240  is preferably provided to be movable in order to keep the air pressure in the first exhaust pathway  210  equal to the air pressure in the second exhaust pathway  220 . 
         [0055]    As such, the adjusting plate  240  is provided in the third exhaust pathway  230  to be movable toward the first exhaust pathway  210  and the second exhaust pathway  220  depending on air intakes, thus reducing occurrence of a vortex in the joining section  231  while preventing the air sucked through the second exhaust pathway  220  from flowing back to the first exhaust pathway  210 . 
         [0056]    Here, in order to enable such shift of the adjusting plate  240 , for example, guide rails (not shown) may be formed on both an upper surface and/or lower surface of the third exhaust pathway  230 , and guide blocks or rollers may be formed on both an upper surface and/or lower surface of the adjusting plate  240  to be slid on the guide rails. 
         [0057]    Meanwhile, as shown in  FIGS. 1 to 3 , the bi-directional ventilation tube  300  is installed at the center of the bathroom ceiling, and the external air traveling tube  100  and the internal air traveling tube  200  each are connected to the inside of the bathroom. 
         [0058]    Specifically, the bi-directional ventilation tube  300  includes an air exhausting part  310  and an air intake part  320 . 
         [0059]    The air exhausting part  310  has a lower end opened and is shaped as a cylinder. A side part of the air exhausting part  310  is connected with the external air traveling tube  100 , and the lower end thereof is connected with the inside of the bathroom. 
         [0060]    Further, the inner diameter of the air exhausting part  310  is formed to be about twice as large as the inner diameter of the external air traveling tube  100 . 
         [0061]    The air intake part  320  is of a hollow shape having ends opened. The air intake part  320  is bent at about 90 degrees to be shaped as the letter “L.” A side, i.e., a right side, of the air intake part  320  is connected with the internal air traveling tube  200 , and another side, i.e., a lower side, thereof is connected with the inside of the bathroom. 
         [0062]    Further, a guiding plate  330  is provided at a lower side of the air intake part  320  along the periphery thereof. The guiding plate  330  is projected towards the bathroom ceiling. 
         [0063]    The guiding plate  330  is formed of an inclined plate of to truncated cone shape inclined downwards. The guiding plate  330  is disposed at a lower part of the outlet of the air exhausting part  310 . The guiding plate  330  is formed to be larger in diameter than the air exhausting part  310 . 
         [0064]    The guiding plate  330  guides the air discharged from the air exhausting part  310  to be widely spread to and the ceiling wall of the bathroom. 
         [0065]    As such, formation of the downwardly-inclined guiding plate  330  along the periphery of the air intake part  320  enables the air discharged from the air exhausting part  310  to flow evenly passing the walls of the bathroom, thus quickly removing the moisture of the walls of the bathroom. 
         [0066]    Meanwhile, the intake adjusting member  400  is provided at a bathroom-facing side of the air intake part  320 . The intake adjusting member  400  moves up and down to adjust the air intake of the air intake part  320 . 
         [0067]    More specifically, the intake adjusting member  400 , as shown in  FIGS. 2 and 3 , includes a fixed part  410  and a moving part  420 . 
         [0068]    The fixed part  410  is shaped as a cylinder and is fixed to the other side of the air intake part  320 . The fixed part  410  includes a nut part  411  a threaded inner circumferential surface in the middle of the fixed part  410  and an opening  412  formed through outside the nut part  411  to connect the inside of the air intake part  320  with the inside of the bathroom. 
         [0069]    The moving part  420  includes a bolt part  421  and a cover  422 . The bolt part  421  is shaped as a long cylinder and has a threaded outer circumferential surface, like a bolt. The cover  422  is coupled with the nut part  411  and rotates to move up and down along the nut part  411 . 
         [0070]    The cover  422  is formed at a lower end of the bolt part  421 . The cover  422  is shaped as a disc. The diameter of the cover  422  is equal or larger than the diameter of the opening  412 . 
         [0071]    The cover  422 , as shown in  FIGS. 2 and 3 , adjusts the degree of opening and closing of the opening  412  as the bolt part  421  moves up and down along the nut part  411 . 
         [0072]    Such intake adjusting member  400 , in case the cover  422  ascends to narrow the opening  412 , reduces the air intake from the inside of the bathroom while increasing the air intake from around the toilet  10  through the second exhaust pathway  220 . 
         [0073]    As such, the intake adjusting member  400  is provided at a lower side of the air intake part  320  to move up and down. Accordingly, the user may adjust the amount of air exhausted from the inside of the bathroom and from around the toilet  10 , thus allowing for easier use. 
         [0074]    Meanwhile, the external air traveling tube  100  includes an air purifying filter  500  to rid the sucked external air of foreign substances and dust. 
         [0075]    The air purifying filter  500  may be a honeycomb filter that may be semi-permanently used, and in some cases, various typical filters may be employed as the air purifying filter  500 . 
         [0076]    In the bathroom ventilation system configured above according to the present invention, the intake of air in the bathroom and supply of external air are simultaneously performed through the bi-directional ventilation tube  300 . Accordingly, even in the airtight state where the bathroom door stands closed, more loads are prevented from being applied to the air exhausting fan  250 , and air circulation is swiftly done. Therefore, the bathroom may remain at a pleasant atmosphere. 
         [0077]    It should be understood that the present invention is not limited to the above described embodiments, and various changes in form and details may be made thereto by one of ordinary skill in the art without departing from the spirit and scope of the present invention defined in the following claims, and such also should belong to the scope of the present invention.

Summary:
The present invention aims to provide a bathroom ventilation system having a bi-directional ventilation tube that exhausts internal air to the outside while supplying external air into the bathroom to allow for quick ventilation in the bathroom and to draw toilet odors as well as air in the bathroom out of the bathroom through an internal air traveling tube, thereby minimizing occurrence of odors. 
     To achieve the above object, according to the present invention, a ventilation system for a bathroom comprises: an external air traveling tube 100 provided at an upper side of a ceiling panel of the bathroom and having an air intake fan 150 that takes air in from an outside and moves the taken-in air to an inside of the bathroom; an internal air traveling tube 200 provided at the upper side of the ceiling panel of the bathroom and having an air exhausting fan 250 that draws air from the inside of the bathroom to the outside; and a bi-directional ventilation tube 300 provided at a ceiling of the bathroom, the bi-directional ventilation tube 300 including an air exhausting part 310 having a side connected with the external air traveling tube 100 and another side connected with the inside of the bathroom and an air intake part 320 having a side connected with the internal air traveling tube 200 and another side connected with the inside of the bathroom.