Patent Publication Number: US-2023148033-A1

Title: Air conditioner

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a Continuation Application of U.S. patent application Ser. No. 16/695,715 filed on Nov. 26, 2019, which is a Continuation Application of U.S. patent application Ser. No. 15/145,322 filed on May 3, 2016, which claims the benefit of Korean Patent Application Nos. 10-2015-0148070 and 10-2016-0036288, filed on Oct. 23, 2015 and Mar. 25, 2016, respectively in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Field 
     Embodiments of the present disclosure relate to arrangement of components inside of a housing of an air conditioner. 
     2. Description of the Related Art 
     An air conditioner is an apparatus that includes a compressor, a condenser, an expansion valve, an evaporator, a blowing fan, and the like and adjusts indoor temperature, humidity, airflow, and the like using a refrigerating cycle. The air conditioner may be classified into a split type air conditioner including an indoor unit disposed inside of a building and an outdoor unit disposed outside of a building and a window type air conditioner including an indoor unit and an outdoor unit both disposed inside a single housing. 
     The indoor unit of the air conditioner includes a heat exchanger for exchanging heat between refrigerant and air, a blower fan for causing air to flow, and a motor for driving the blower fan, thereby cooling or heating the interior of a room. 
     When the heat exchanger is provided in an annular shape, an annular discharge port may be provided to correspond to the heat exchanger, and in this case, the formation of the discharge port may be limited by components in the housing such as a drain pump disposed inside the housing or a refrigerant pipe connected to the heat exchanger. 
     Accordingly, when the discharge port is formed into an irregular shape, a problem may arise that air discharged from the air conditioner is irregularly delivered to the interior of the room. 
     SUMMARY 
     Therefore, it is an aspect of the present disclosure to provide an air conditioner that may secure a discharge port regularly disposed by an appropriate arrangement of components in the housing. 
     It is another aspect of the present invention to provide an air conditioner in which some of the internal components of an indoor unit of the air conditioner formed in a circular shape may be arranged on a protrusion cover protruding from a circular housing, thereby maximizing a discharge port. 
     It is still another aspect of the present invention to provide an air conditioner in which a condensate water collecting space disposed outside of the housing may be provided in a drain tray of the air conditioner. 
     It is yet another aspect of the present invention to provide an air conditioner in which components of an indoor unit of the air conditioner may be coupled to one another by a coupling member disposed outside. 
     It is yet another aspect of the present invention to provide an air conditioner in which a discharge port of the air conditioner which does not includes a blade may be easily opened and closed. 
     Additional aspects of the disclosure will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the disclosure. 
     In accordance with one aspect of the present disclosure, an air conditioner includes: a housing that includes a cylindrical portion; a heat exchanger that is provided inside the housing; and a refrigerant pipe connecting unit that connects the heat exchanger to an external refrigerant pipe, wherein the housing includes a first protrusion portion that protrudes from the cylindrical portion to cover the refrigerant pipe connecting unit. 
     Here, the first protrusion portion may include a first surface that extends in a tangential direction of an outer circumferential surface of the cylindrical portion. 
     Also, the first protrusion portion may further include a second surface that connects an end of the first surface and the outer circumferential surface of the cylindrical portion, and the refrigerant pipe connecting unit is connected to the external refrigerant pipe through the second surface. 
     Also, the air conditioner may further include a drain extraction unit that includes a drain pump for collecting condensate water generated from the heat exchanger and a drain pipe connecting portion for connecting the drain pump to an external drain pipe, wherein the housing further includes a second protrusion portion that protrudes from the cylindrical portion to cover the drain extraction unit. 
     Also, each of the first and second protrusion portions may include a first surface that extends in a tangential direction of an outer circumferential surface of the cylindrical portion and a second surface that connects an end of the first surface and the outer circumferential surface of the cylindrical portion, the refrigerant pipe connecting unit may pass through the second surface of the first protrusion portion, and the drain pipe connecting portion may pass through the second surface of the second protrusion portion. 
     Also, the first surface of the first protrusion portion and the first surface of the second protrusion portion may extend in the same direction. 
     Also, the air conditioner may further include a plurality of discharge ports including an arc shape; and at least one blocking region that is provided between the plurality of discharge ports, wherein the refrigerant pipe connecting unit is disposed to correspond to one of the at least one blocking region. 
     Also, the air conditioner may further include a drain extraction unit that includes a drain pump for collecting condensate water generated from the heat exchanger, wherein the drain extraction unit is disposed to correspond to the other one of the at least one blocking region. 
     Also, the air conditioner may further include an airflow control fan that is provided inside the housing so that a part of the air discharged from the plurality of discharge ports is drawn into the housing, wherein the airflow control fan is disposed to correspond to the at least one blocking region. 
     Also, the first protrusion portion may protrude in an axial direction of the cylindrical portion. 
     Also, the air conditioner may further include a drain tray that is provided to collect condensate water generated from the heat exchanger, and includes an annular shape having a radius larger than a radius of the cylindrical portion, wherein the drain tray includes an outer rib that protrudes upward along an outer perimeter side of the drain tray. 
     Also, the air conditioner may further include a heat insulating material that is disposed to abut an inner circumferential surface of the housing, wherein the drain tray further includes an inner rib that protrudes upward along an inner circumferential surface of the heat insulating material to abut the inner circumferential surface of the heat insulating material. 
     Also, at one side of the inner circumferential surface of the housing, a wire accommodation portion that protrudes in a radial direction may be provided along the inner circumferential surface of the housing, so that a wire for electrically connecting electronic components of the air conditioner is accommodated in the wire accommodation portion. 
     In accordance with another aspect of the present disclosure, an air conditioner includes: a first housing; a heat exchanger that is provided inside the first housing; a drain tray that is disposed to collect condensate water generated from the heat exchanger; and a coupling member that couples the first housing to the drain tray, wherein the coupling member includes a first portion that is inserted into the first housing, and a second portion that extends from the first portion and protrudes to the outside of the first housing to be coupled to the drain tray. 
     Here, the air conditioner may further include a second housing that is disposed at one side of the drain tray, wherein the second housing is coupled to the second portion. 
     Also, the air conditioner may further include a cover member that covers a boundary side of the second housing, wherein the cover member is coupled to the second portion. 
     Also, the second housing and the drain tray may respectively include a first assembling unit and a second assembling unit which respectively protrude to the outside from boundaries of the second housing and the drain tray, and the first assembling unit, the second assembling unit, and the cover member may be stacked on the second portion and coupled to the second portion. 
     Also, the coupling member may include a bolt coupling portion that extends from the first portion to the outside of the first housing and is coupled to a bolt. 
     Also, the first housing may further include a cylindrical outer circumferential surface, the drain tray may include an outer circumferential surface having a radius lager than a radius of the first housing, the coupling member may further include a third portion that connects the first portion and the second portion, and the third portion may extend to the outside of the first housing by a difference between the radius of the drain tray and the radius of the first housing. 
     Also, the second housing may be hook-coupled to the drain tray. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other aspects of the disclosure will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG.  1    is a perspective view showing an air conditioner according to an embodiment of the present invention; 
         FIG.  2    is a side cross-sectional view taken along a line I-I shown in  FIG.  1   ; 
         FIG.  3    is an enlarged view showing a part of  FIG.  2   ; 
         FIG.  4    is an exploded perspective view showing an air conditioner according to an embodiment of the present invention; 
         FIG.  5    is an exploded perspective view showing an intermediate housing and a lower housing of an air conditioner according to an embodiment of the present invention; 
         FIG.  6    is a rear view showing a state in which an inner first lower housing and a second lower housing of an air conditioner according to an embodiment of the present invention are removed; 
         FIG.  7    is a rear view showing a state in which an inner first lower housing of an air conditioner is additionally removed from  FIG.  6   ; 
         FIG.  8    is a rear view showing a state in which a lower housing, an intermediate housing, and a drain tray of an air conditioner according to an embodiment of the present invention are removed; 
         FIG.  9    is a perspective view showing a state in which an upper housing of an air conditioner according to an embodiment of the present invention is removed; 
         FIG.  10    is a rear view showing a region of a discharge flow passage in a state in which a suction panel of an air conditioner according to an embodiment of the present invention is removed; 
         FIG.  11    is a perspective view showing an air conditioner according to an embodiment of the present invention; 
         FIG.  12    is a perspective view showing an air conditioner according to another embodiment of the present invention; 
         FIG.  13    is a perspective view showing a drain tray of an air conditioner according to an embodiment of the present invention; 
         FIG.  14    is a side cross-sectional view showing a part of a drain tray and an upper housing of an air conditioner according to an embodiment of the present invention; 
         FIG.  15    is a side cross-sectional view showing a part of a drain tray and an upper housing of an air conditioner according to another embodiment of the present invention; 
         FIG.  16    is a partial perspective view showing a drain tray and an upper housing of an air conditioner according to an embodiment of the present invention; 
         FIG.  17    is a view showing the inside of an upper housing of an air conditioner according to an embodiment of the present invention; 
         FIG.  18    is a view showing a state in which a drain tray and a lower housing of an air conditioner according to an embodiment of the present invention are coupled; 
         FIG.  19    is a view showing a state in which a cover member, a lower housing, a drain tray, and an upper housing of an air conditioner according to an embodiment of the present invention are coupled; 
         FIG.  20    is a view showing a state in which a cover member, a lower housing, a drain tray, and an upper housing of an air conditioner according to an embodiment of the present invention are disassembled; 
         FIG.  21    is an exploded perspective view showing some of components of an air conditioner according to another embodiment of the present invention; 
         FIG.  22    is a schematic rear view showing a state in which an opening and closing unit is opened while a second lower housing of an air conditioner according to another embodiment of the present invention is removed; 
         FIG.  23    is a schematic rear view showing a state in which an opening and closing unit is closed while a second lower housing of an air conditioner according to another embodiment of the present invention is removed; 
         FIG.  24    is a side cross-sectional view showing a portion A of  FIG.  23   ; 
         FIG.  25    is a schematic rear view showing a state in which an opening and closing unit is opened while a first lower housing of an air conditioner according to another embodiment of the present invention is removed; 
         FIG.  26    is a schematic rear view showing a state in which an opening and closing unit is closed while a first lower housing of an air conditioner according to another embodiment of the present invention is removed; 
         FIG.  27    is an exploded perspective view showing some of components of an air conditioner according to another embodiment of the present invention; 
         FIG.  28    is a schematic rear view showing a state in which an opening and closing unit is closed while a second lower housing of an air conditioner according to another embodiment of the present invention is removed; 
         FIG.  29    is a schematic rear view showing a state in which an opening and closing unit is opened while a second lower housing of an air conditioner according to another embodiment of the present invention is removed; 
         FIG.  30    is a schematic rear view showing a state in which an opening and closing unit is opened while a first lower housing of an air conditioner according to another embodiment of the present invention is removed; 
         FIG.  31    is a schematic rear view showing a state in which an opening and closing unit is closed while a first lower housing of an air conditioner according to another embodiment of the present invention is removed; 
         FIG.  32    is an exploded perspective view showing some of components of an air conditioner according to another embodiment of the present invention; 
         FIG.  33    is a schematic rear view showing a state in which a second lower housing of an air conditioner according to another embodiment of the present invention is removed; 
         FIG.  34    is a schematic rear view showing a state in which an opening and closing unit is closed while a first lower housing of an air conditioner according to another embodiment of the present invention is removed; 
         FIG.  35    is a schematic rear view showing a state in which an opening and closing unit is opened while a first lower housing of an air conditioner according to another embodiment of the present invention is removed; 
         FIG.  36    is a schematic rear view showing a state in which an opening and closing unit is closed while a first lower housing of an air conditioner according to still another embodiment of the present invention is removed; and 
         FIG.  37    is a schematic rear view showing a state in which an opening and closing unit is opened while a first lower housing of an air conditioner according to still another embodiment of the present invention is removed. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments disclosed in the present specification and the configurations shown in the drawings are just preferred embodiments of the present invention and do not cover all the technical idea of the present invention. Thus, it should be appreciated that such embodiments may be replaced by various equivalents and modifications at a point of time when the present application is filed. 
     Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. 
     In addition, terminologies used in the present specification are to describe the exemplary embodiments and not to limit the present invention. In the present specification, unless particularly described in the description, a singular form includes a plural form. “Comprises/includes” and/or “comprising/including” used in the specification does not exclude the presence or addition of at least one another constituent element, step, operation, and/or device with respect to the described constituent element, step, operation/or device. 
     It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present invention. As used here, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     In addition, as to terms such as “upper side”, “upper”, “lower side”, and “lower” used in the present specification, the side at which the a suction port is provided in the air conditioner in  FIG.  1    will be described as the lower side, and the side above the lower side will be described as the upper side in the vertical direction of an air conditioner according to an embodiment of the present invention shown in  FIG.  1   . 
     An air conditioner according to an embodiment of the present invention is an air conditioner that does not include a blade for conditioning discharged air. However, without being limited to an embodiment of the present invention, the present invention may be applied to an air conditioner including a blade. 
     In addition, the air conditioner according to an embodiment of the present invention is an air conditioner including a heat exchanger provided in an annular shape. However, without being limited to an embodiment of the present invention, the present invention may be applied to an air conditioner including a heat exchanger provided in a rectangular shape or in various shapes. 
     Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
     With reference to  FIGS.  1  to  7   , a schematic configuration of an air conditioner according to an embodiment of the present invention will be described. 
     An indoor unit  1  of the air conditioner may be installed in the ceiling L. At least a part of the indoor unit  1  of the air conditioner may be embedded in the ceiling L. 
     The indoor unit  1  of the air conditioner includes a housing  10  having a suction port  11  and a discharge port  33 , a heat exchanger  80  provided inside the housing  10 , and a blower fan  40  for causing air to flow. 
     The housing may have a substantially circular shape when viewed in the vertical direction. The housing  10  may be constituted of an upper housing  20  disposed inside the ceiling L, an intermediate housing  21  disposed below the upper housing  20 , and a lower housing  30  coupled to the bottom of the intermediate housing  21 . 
     However, although the intermediate housing  21  and the lower housing  30  have been differentiated using terms such as intermediate, and lower for convenience of the description, the intermediate housing  21  and the lower housing  30  may be formed as a separable single component. 
     That is, the intermediate housing  21  may be seen as a single configuration of the lower housing  30 . Thus, the intermediate housing according to an embodiment of the present invention, a first lower housing, and a second lower housing which will be described later may be respectively named as a first lower housing, a second lower housing, and a third lower housing, but without being limited thereto, they may also be named in various ways. 
     The lower housing  30  may include a first lower housing  31  that is coupled to a lower portion of the intermediate housing  21  and has an annular shape formed along a perimeter of the intermediate housing  21  and a second lower housing  32  that is coupled to a lower portion of the first lower housing  31  and covers the lower portion of the first lower housing  31 . 
     The first lower housing  31  may be constituted with an outer first lower housing  31   a  that is disposed along a perimeter at a lower side of the intermediate housing  21  and formed in an annular shape and an inner first lower housing  31   b  that is disposed radially inside of the outer first lower housing  31   a  and provided in an annular shape. The outer first lower housing  31   a  and the inner first lower housing  31   b  may be provided to be detachable as shown in the embodiment of the present invention but also may be integrally formed (see  FIG.  5   ). 
     A suction port  11  which communicates with the outside to the blower fan  40  and suctions external air may be provided at the center portion of the lower housing  30 . That is, the center portion of the second lower housing  32  is open, and an opening of the second lower housing  32  communicates with the blower fan  40  via a space such that external air may be introduced into the housing  10 . 
     A suction panel  15  that covers the suction port  11  and includes a suction grill  16  provided with a plurality of holes so that air is suctioned into the suction port  11  may be provided at the lower side of the suction port  11 , and a discharge port  33  through which air is discharged may be formed radially outside of the suction panel  15 . The discharge port  33  may have a substantially circular shape when viewed in the vertical direction. 
     The discharge port  33  may be formed in the first lower housing  31 . That is, the discharge port  33  may be formed in a separation space formed between the radial directions of the outer first lower housing  31   a  and the inner first lower housing  31   b.  Specifically, the discharge port  33  may be defined as a space formed between an inner circumferential surface of the outer first lower housing  31   a  and an outer circumferential surface of the inner first lower housing  31   b  from an opening of the intermediate housing  21  (see  FIGS.  2  and  5   ). 
     However, the discharge port  33  may be an opening formed in the lower housing  30  without being limited to the definition described as being the space that communicates with the outside so that air heat-exchanged in the heat exchanger  80  is discharged to the outside of the lower housing  30  and may be formed in a different configuration. 
     The upper housing  20  may be provided to cover the heat exchanger  80 . The heat exchanger  80  may include the annular shape so that the upper housing  20  may include a cylindrical portion  20   d  having a cylindrical shape to cover the heat exchanger  80 . 
     By such a structure, the indoor unit  1  of the air conditioner may suction air from the lower side thereof, cool and heat the suctioned air, and then discharge the cooled and heated air to the lower side again. 
     A coanda curved surface portion  34  that guides the air discharged through the discharge port  33  may be formed on the inner circumferential surface of the outer first lower housing  31   a.  The coanda curved surface portion  34  may make airflow discharged through the discharge port  33  flow in a close contact with the coanda curved surface portion  34 . 
     A filter  17  for filtering dust from the air suctioned into the suction grill  16  may be coupled to an upper surface of the suction panel  15 . 
     A suction guide  35  for guiding air passing through the suction panel  15  to flow up to the blower fan  40  may be provided at the center portion of the second lower housing  32 . The heat exchanger  80  may have a substantially circular shape when viewed in the vertical direction. 
     The heat exchanger  80  may be placed on a drain tray  90  so that condensate water generated from the heat exchanger  80  may be collected in the drain tray  90 . 
     The blower fan  40  may be provided radially inside of the heat exchanger  80 . The blower fan  40  may be a centrifugal fan for suctioning air in an axial direction and discharging the suctioned air in a radial direction. A blower motor  41  for driving the blower fan  40  may be provided in the indoor unit  1  of the air conditioner. By such a structure, the indoor unit  1  of the air conditioner may suction air in a room, cool or heat the suctioned air, and then discharge the cooled or heated air into the room. 
     The indoor unit  1  of the air conditioner may further include an airflow controller  50  for controlling a discharged airflow. 
     The airflow controller  50  may suction air in the vicinity of the discharge port  33  and change the pressure, thereby controlling the direction of the discharged airflow. In addition, the airflow controller  50  may control the amount of the air suctioned in the vicinity of the discharge port  33 . That is, the airflow controller  50  may control the direction of the discharged airflow by controlling the amount of the air drawn in the vicinity of the discharge port  33 . 
     Here, controlling the direction of the discharged airflow means controlling the angle of the discharged airflow. 
     The airflow controller  50  may suction air at one lateral side in the advancing direction of the discharged airflow when suctioning the air in the vicinity of the discharge port  33 . 
     That is, as shown in  FIG.  3   , assuming the advancing direction of the discharged airflow when the airflow controller  50  is not operated is a direction A 1 , the airflow controller  50  may be operated to suction air at one lateral side in the direction A 1  so that the advancing direction of the discharged airflow may be switched to a direction A 2 . 
     In this case, the angle to which the advancing direction of the discharged airflow is switched may be controlled by the amount of the air suctioned. That is, when the suction is reduced, the advancing direction may be changed by a small angle, and when the suction is increased, the advancing direction may be changed by a large angle. 
     The airflow controller  50  may discharge the suctioned air to the opposite lateral side in the advancing direction A 1  of the discharged airflow. Accordingly, an angle of the discharged airflow may be increased, and airflow control may become smoother. 
     The airflow controller  50  may suction air radially outside of the discharge port  33 . In this manner, the airflow controller  50  suctions air radially outside of the discharge port  33 , and therefore the discharged airflow may be widely spread radially outside the discharge port  33  from a radial center portion of the discharge port  33 . 
     The airflow controller  50  includes an airflow control fan  60  that generates a suction force for suctioning air in the vicinity of the discharge port  33 , an airflow control motor  61  that drives the airflow control fan  60 , an airflow control fan case  62  that covers the airflow control fan  60  and the airflow control motor  61 , and a guide flow passage  70  that guides air drawn by the airflow control fan  60 . 
     The airflow control fan  60  may be accommodated inside the lower housing  30 . Specifically, the airflow control fan case  62  may be provided in a space formed at a lower side of the first lower housing  31 . However, without being limited thereto, the airflow control fan  60  may be disposed inside the lower housing  30  and may be disposed in a space provided by the second lower housing  32  as well as a space provided by the lower side of the first lower housing  31  (see  FIGS.  5  and  6   ). 
     In the present embodiment, three airflow control fans  60  are provided at an angle of 120°, but without being limited thereto, the number and arrangement of the airflow control fans  60  may be variously designed. 
     In addition, in the present embodiment, a centrifugal fan is used as the airflow control fan  60 , but the airflow control fan  60  is not limited thereto, and a variety of fans such as an axial-flow fan, a cross-flow fan, a mixed-flow fan, and the like may be used according to design specifications. 
     The guide flow passage  70  connects an inlet  71  for suctioning air in the vicinity of the discharge port  33  and an outlet  72  for discharging the suctioned air. 
     The inlet  71  may be formed at a side of the coanda curved surface portion  34  of the first lower housing  31 . Specifically, the inlet  71  may be provided on an inner surface of the outer first lower housing  31   a.    
     The outlet  72  may be positioned in the vicinity of the discharge port  33  at the opposite side of the inlet  71 . Specifically, the outlet  72  may be provided in the inner first lower housing  31   b.    
     By such a structure, as described above, the airflow controller  50  may discharge the suctioned air to the opposite lateral side of the advancing direction A 1  of the discharged airflow, and an angle of the discharged airflow may be increased, and airflow control may become smoother. 
     The guide flow passage  70  may include a first flow passage  70   a  that is formed in the circumferential direction of the lower housing  30  and communicates with the inlet  71 , a second flow passage  70   b  that extends radially inward from the first flow passage  70   a,  and a third flow passage  70   c  that is formed in a region in which the airflow control fan  60  is seated. 
     Accordingly, air suctioned via the inlet  71  may pass through the first flow passage  70   a,  the second flow passage  70   b,  and the third flow passage  70   c,  and then may be discharged via the outlet  72 . 
     The guide flow passage  70  may be formed by the intermediate housing  21 , the first lower housing  31 , and the second lower housing  32 . 
     Specifically, the first flow passage  70   a  and the second flow passage  70   b  may be formed by an inner space formed by the intermediate housing  21  and the outer first lower housing  31   a,  and the third flow passage  70   c  may be formed by an inner space formed by the inner first lower housing  31   b  and the airflow control fan case  62  (see  FIGS.  5  to  7   ). 
     However, such a structure of the guide flow passage  70  may be merely an example, and there is no limitation in the structure, shape, and arrangement of the guide flow passage  70  as long as the guide flow passage  70  connects the inlet  71  and the outlet  72 . 
     By such a structure, the indoor unit of the air conditioner according to an embodiment of the present invention may control the discharged airflow even without the blade structure, compared to a conventional structure in which a blade is provided at the discharge port and the discharged airflow is controlled by rotation of the blade. Accordingly, since there is no interference with the blade, a discharge rate may be increased, and flow noise may be reduced. 
     In addition, a discharge port of an indoor unit of a conventional air conditioner may have only a linear shape in order to rotate the blade, but the discharge port of the indoor unit according to an embodiment of the present invention may be provided in a circular shape so that the housing, the heat exchanger, and the like may be provided in the circular shape, and therefore aesthetics may be improved with a differentiated design, and, considering the blower fan generally has a circular shape, the airflow may become more natural and the pressure loss may be reduced such that an improved cooling or heating performance of the air conditioner may result. 
     Hereinafter, a blocking region  100  for blocking a part of a discharge flow passage  36  will be described in detail. 
     As shown in  FIG.  8   , the annular discharge flow passage  36  in which discharged air flows may be provided in a space between the outside of the heat exchanger  80  and the inner surface of the cylindrical housing  10 . 
     Air in the discharge flow passage  36  may be air that is heat-exchanged with the heat exchanger  80  by the blower fan  40  and then moved in the radially outside direction of the heat exchanger  80  and may be discharged to the outside of the housing  10  along the discharge port  33 . 
     As shown in  FIGS.  9  and  10   , the blocking region  100  that extends by a preset length in the circumferential direction of the discharge port  33  may be provided at one side of the discharge flow passage  36 . Three blocking regions  100  may be provided and spaced apart from one another by a preset interval along the circumferential direction. 
     When the discharge port  33  is provided in a closed-loop annular shape to correspond to the discharge flow passage  36  so that air is discharged in all directions, a relatively high pressure is formed in the vicinity of the discharge port  33 , and a relatively low pressure is formed in the vicinity of the suction port  11 . In addition, since air is discharged in all directions of the discharge port  33  and an air curtain is formed, air to be suctioned through the suction port  11  may not be supplied to a side of the suction port  11 . In this situation, the air discharged from the discharge port  33  is re-suctioned through the suction port  11 , the re-suctioned air causes a dew formation phenomenon inside the housing  10 , and the discharged air is lost to result in a reduction in the quality of air sensed by body. 
     Accordingly, the blocking regions  100  according to an embodiment of the present invention may be provided at one side of the discharge flow passage  36  and partition the discharge port  33  by a preset length from a complete annular shape, and the discharge port  33  may be formed in an annular shape of which a part is blocked. In other words, the discharge port  33  may be provided in an arc shape. 
     The blocking regions  100  may be provided on the intermediate housing  21 , the first lower housing  31 , and the drain tray  90  (a region provided to partition the discharge port  33  from the first lower housing  31  among the blocking regions  100  is separately defined as a bridge  110 ). 
     According to an embodiment of the present invention, a section that partitions three discharge ports  33  is provided in the first lower housing  31 , so that three bridges  110  may be provided. 
     The bridge  110  may be a space that partitions the discharge port  33  in the first lower housing  31  as described above and form a part of the second flow passage  70   b.    
     Accordingly, the discharge flow passage  36  may be divided into a discharge section S 1  in which air passes through the discharge port  33  along a region other than the blocking region  100  in which air flows and is discharged and a non-discharge section S 2  in which air is blocked by the blocking region  100  and is not discharged. 
     That is, the blocking region  100  may form the non-discharge section S 2  that supplies air suctioned through the suction port  11 . In addition, the blocking region  100  may reduce a pressure difference between the low pressure in the vicinity of the suction port  11  and the high pressure in the vicinity of the discharge port  33 . 
     Accordingly, as the area of the blocking region  100  is increased, the non-discharge section S 2  increases, and the discharge section S 1  correspondingly decreases. 
     However, the discharge section S 1  and the non-discharge section S 2  shown in  FIGS.  9  and  10    are schematically shown for convenience of description, and they are not divided by boundary lines in a dichotomous manner as shown in  FIGS.  9  and  10    and are divided only by a flow of air. 
     In the indoor unit  1  of the air conditioner, although the three blocking regions  100  are provided with the same interval between one another, that is, at every 120 degrees, the present invention is not limited thereto, and only one blocking region  100  may be provided. Also, two blocking regions  100  may be provided at an angle of 180°, and four blocking regions  100  may be provided at an angle of 90°. 
     In addition, a plurality of blocking regions  100  may be disposed at mutually different angles. Also, five blocking regions  100  or more may be provided. That is, the number of the blocking regions  100  is not limited. However, the sum of lengths in the circumferential direction of such blocking regions  100  may be provided with 5% or more and 40% or less of the length in the circumferential direction of the discharge port  33  or the circumferential length of the discharge flow passage  36 . That is, a ratio of the sum of the discharge section S 1  and the non-discharge section S 2  to the non-discharge section S 2  may be provided to be 5% or more and 40% or less. 
     By such blocking regions  100 , air from the discharge port  33  may be spread and discharged in order to cool or heat a room without being re-suctioned by the suction port  11  as described above. 
     The airflow controller  50  may be disposed in the blocking region  100 . The discharge flow passage  36  is provided in the annular shape outside the heat exchanger  80 , and this is for being able to restrict a flow of air introduced into the discharge port  33  when the airflow controller  50  is disposed in a space other than the blocking region  100 . 
     Air in the discharge flow passage  36  may be discharged to the outside of the housing  10  through the discharge port  33  along a region other than the blocking region  100 , and when a component such as the airflow controller  50  is disposed in the region other than the blocking region  100 , the discharge section S 1  in which air is discharged to the discharge port  33  may be reduced so that the flow of the air may be limited and efficiency of the air conditioner may be reduced. 
     That is, when the airflow controller  50  is disposed at the discharge port  33 , the region itself in which the airflow controller  50  is disposed becomes the blocking region  100 , so that the non-discharge section S 2  is increased. Accordingly, the airflow controller  50  may be provided in the blocking region  100 , thereby maximizing the discharge section S 1 . 
     Specifically, the airflow control fan  60  may be disposed on the bridge  110 , and at least a part of the second flow passage  70   b  that communicates the airflow control fan  60  and the inlet  71  provided in the first lower housing  31  may be formed by the bridge  110 . A part of the intermediate housing  21  that forms the other part of the second flow passage  70   b  may be provided on the blocking region  100 , thereby maximizing the discharge section S 1  (see  FIG.  7   ). 
     In addition, the indoor unit  1  of the air conditioner may include a display unit  28  that displays an operating status of the air conditioner to a user, and the display unit  28  may be also disposed in the blocking region  100  in order to maximize the discharge section S 1 . An electronic unit (not shown) for driving the display unit  28  may be also disposed at an upper side of the display unit  28  and disposed in the blocking region  100  (see  FIG.  7   ). 
     As shown in  FIG.  9   , a drain extraction unit  94  and a refrigerant pipe connecting unit  85  may be provided on the blocking region  100 . This is to maximize the discharge section S 1  by disposing the drain extraction unit  94  and the refrigerant pipe connecting unit  85  in the blocking region  100 , as described above. 
     The drain extraction unit  94  may be provided in the drain tray  90  to discharge condensate water collected in the drain tray  90  to the outside of the indoor unit  1  of the air conditioner. The drain extraction unit  94  may include a drain pump that discharges condensate water to the outside of the indoor unit  1  of the air conditioner by pumping the condensate water and a drain pipe connecting portion  93  that connects an external drain pipe to the drain pump  92 . 
     The refrigerant pipe connecting unit  85  connects to a refrigerant pipe  84  for supplying refrigerant from the outside to the heat exchanger  80 . The refrigerant pipe connecting unit  85  includes a pipe portion that passes through the upper housing  20 , so that the refrigerant pipe  84  is connected to the heat exchanger  80 . 
     The refrigerant pipe connecting unit  85  may include a header  83  that is connected to a part of tubes  82  that is provided to make a refrigerant flow in the heat exchanger  80  and to the pipe portion of the refrigerant pipe connecting unit  85  to supply or collect refrigerant to the tubes  82 . 
     In particular, the drain extraction unit  94  and the refrigerant pipe connecting unit  85  are disposed in the blocking region  100 , so that the shape of the annular heat exchanger  80  may be maintained. 
     Specifically, the drain extraction unit  94  and the refrigerant pipe connecting unit  80  may be disposed at a height corresponding to the height at which the heat exchanger  80  is disposed, and because of this, when the drain extraction unit  94  and the refrigerant pipe connecting unit  85  are disposed in the region other than the blocking region  100 , partial sections of the heat exchanger  80  may be provided in a shape having a bent portion rather than an annular shape in order to secure discharge section S 1  corresponding to each disposed component. 
     When the bent portion is formed in the heat exchanger  80 , heat exchange fins  81  which are disposed in the tubes  82  passing through the entire heat exchanger  80  to enlarge a heat exchange area cannot be disposed at regular intervals in the bent portion, so that the heat exchange efficiency may be reduced. 
     That is, the heat exchanger  80  according to an embodiment of the present invention may be provided in the circular and annular shape so that each of the heat exchange fins  81  may be disposed at regular intervals, but a bent portion may be formed in a partial section of the heat exchanger  80 . In this case, due to the irregular intervals of the heat exchange fins  81 , a flow of the suctioned air is not constant, and therefore the heat exchange efficiency may be reduced. 
     In addition, in the case of the conventional air conditioner, the heat exchanger is disposed in a rectangular shape and the drain extraction unit and the refrigerant pipe connecting unit are disposed at corner sides of a rectangular shape, and the bent portion is included in the heat exchanger in order to secure a space for allowing each component to be disposed at the corner sides. 
     Accordingly, the problem of the reduction in the efficiency of the heat exchanger due to the bent portion has occurred as described above, and therefore the heat exchanger is formed asymmetrically due to the formation of the bent portion and the corresponding discharge port is also formed asymmetrically, thereby failing to form uniformly discharged airflow into a room. 
     However, according to an embodiment of the present invention, the heat exchanger  80  is provided in the circular and annular shape, and the drain extraction unit  94  and the refrigerant pipe connecting unit  85  are disposed in the blocking region  100  so that the heat exchanger is provided in a certain symmetric shape so that the heat exchange efficiency may not be reduced and, at the same time, a discharge port having a symmetric shape may be formed, thereby solving the conventional problem. 
     Hereinafter, a protrusion portion  25  that protrudes radially outside of the housing  10  in order for the cylindrical housing  10  to cover the drain extraction unit  94  and the refrigerant pipe connecting unit  85  will be described. 
     As shown in  FIG.  11   , the upper housing  20  may be provided in the cylindrical shape, and the protrusion portion  25  that protrudes from the cylindrical portion  20   d  of the upper housing  20  may be provided in order to cover the drain extraction unit  94  and the refrigerant pipe connecting unit  85  disposed in the blocking region  100  as described above. 
     The drain extraction unit  94  and the refrigerant pipe connecting unit  85  should be disposed radially outside of the heat exchanger  80  while being disposed in the blocking region  100 , in order to improve the performance of the air conditioner as described above. 
     Here, when the protrusion portion  25  is not formed, the drain extraction unit  94  and the refrigerant pipe connecting unit  85  may be located inside the cylindrical housing  10 , and some components of the drain extraction unit  94  and the refrigerant pipe connecting unit  85  may be disposed radially inside of the heat exchanger  80  such that the drain extraction unit  94  and the refrigerant pipe connecting unit  85  may not be efficiently disposed. 
     Accordingly, the protrusion portion  25  may be provided in the upper housing  20  and disposed in the blocking region  100 , so that it is possible to cover some components of the drain extraction unit  94  and the refrigerant pipe connecting unit  85  which can be disposed radially outside of the upper housing  20 . 
     The protrusion portion  25  may include a first protrusion surface  25   a  that extends in a direction tangential to the outer circumferential surface of the cylindrical portion  20   d  of the upper housing  20  and a second protrusion surface  25   b  that abuts on the first protrusion surface  25   a  and extends in a direction normal to the outer circumferential surface of the upper housing  20  (since the cylindrical portion  20   d  includes the outer circumferential surface side of the cylindrical upper housing  20 , the outer circumferential surface of the cylindrical portion  20   d  and the outer circumferential surface of the upper housing  20  have the same meaning). 
     The first protrusion surface  25   a  may extend in a direction corresponding to the tangential direction of the outer circumferential surface of the upper housing  20 , and the second protrusion surface  25   b  may extend in a direction corresponding to the normal direction of the outer circumferential surface of the upper housing  20 , and therefore the first protrusion surface  25   a  and the second protrusion surface  25   b  may be formed to extend substantially in the vertical direction. 
     A part of each of the drain extraction unit  94  and the refrigerant pipe connecting unit  85  may be provided in a space provided between the first protrusion surface  25   a  and the second protrusion surface  25   b,  so that a part of each of the drain extraction unit  94  and the refrigerant pipe connecting unit  85  which are disposed outside of the outer circumferential surface of the upper housing  20  may not be exposed to the outside. 
     A plurality of protrusion portions  25  may be provided to cover each of the drain extraction unit  94  and the refrigerant pipe connecting unit  85 . Specifically, a plurality of first protrusion surfaces  25   a  may be provided to extend in each corresponding direction, and a plurality of second protrusion surfaces  25   b  that extend from the first protrusion surfaces  25   a  may each be provided to face the same one side, so that the plurality of protrusion portions  25  may be provided in a substantially symmetrical shape with respect to the outer circumferential surface of the upper housing  20 . 
     A plurality of connection holes  25   c  through which the drain pipe connecting portion  93  and the refrigerant pipe  84  pass may be provided in the plurality of protrusion portions  25 , so that the refrigerant pipe  84  connected to the drain pipe connection portion  93  and the heat exchanger  80  may extend outside of the upper housing  20 . 
     A plurality of connection holes  25   c  may each be provided in the plurality of second protrusion surfaces  25   b.  The plurality of second protrusion surfaces  25   b  may be disposed to face the same one side, so that the plurality of connection holes  25   c  may be also disposed to face the same one side. 
     Accordingly, the drain pipe connecting portion  93  and the refrigerant pipe  84  which pass through the plurality of connection holes  25   c  may each extend to the outside of the housing  10  toward the same direction. 
     The drain pipe connecting portion  93  and the refrigerant pipe  84  extend to the same side, so that there may be an effect of facilitating pipe when the indoor unit  1  of the air conditioner is embedded in the ceiling. 
     In addition, the plurality of connection holes  25   c  may be provided in the same plane as the plurality of second protrusion surfaces  25   b,  so that an operation of forming the connection holes  25   c  may be easily performed. When the protrusion portion  25  is provided in the form of a curved surface without including the first protrusion surface  25   a  and the second protrusion surface  25   b,  the connection holes  25   c  should be formed on the curved surface, and this is because a process of forming holes on the curved surface is more difficult than a process of forming holes on a flat surface. 
     Accordingly, the plurality of connection holes  25   c  may be easily formed on the plurality of second protrusion surfaces  25   b.  However, without being limited thereto, the plurality of connection holes  25   c  may be also formed on the plurality of the first protrusion surfaces  25   a,  but each formed on the plurality of second protrusion surfaces  25   b  each facing the same side so that directions of the plurality of connection holes  25   c  coincide as described above. 
       FIG.  12    is a perspective view showing an upper housing  20  according to another embodiment of the present invention. As shown in  FIG.  12   , a single protrusion portion  25 ′ is provided so that the drain pipe connecting portion  93  and the refrigerant pipe  94  may extend from the single protrusion portion  25 ′. 
     Although not shown, this may be a shape obtained when a single blocking region  100  is provided as described above. This is because a circumferential length of the blocking region  100  may be provided long even though a single blocking region  100  is formed so that the drain extraction unit  94  and the refrigerant pipe connecting unit  85  are both disposed in the single blocking region  100 . 
     Hereinafter, the drain tray  90  and the upper housing  20  to which the drain tray  90  is coupled will be described in detail. 
     The drain tray  90  may be disposed below the heat exchanger  80  so as to collect condensate water generated from the heat exchanger  80 . In addition, an opening  95  through which the discharge section S 1  may penetrate may be provided in a section of the drain tray  90  other than the blocking region  100 , and the opening  95  is not formed in order to block the discharge flow passage  36  in the section of the drain tray  90  disposed in the blocking region  100 . 
     As shown in  FIGS.  13  and  14   , a top surface  90   a  of the drain tray  90  may be provided to extend outside of the outer circumferential surface  20   a  of the upper housing  20 . An outer rib  96  that protrudes upward may be provided outside of the top surface  90   a  that extends outside of the outer circumferential surface  20   a  of the upper housing  20 . 
     In addition, an extension portion  20   b  that extends radially outside of the upper housing  20  by the length which the top surface  90   a  of the drain tray  90  extends outward may be provided at a bottom side of the upper housing  20 . 
     The upper housing  20  and the drain tray  90  may be coupled to each other while abutting on each other in the vertical direction, and when the upper housing  20  and the drain tray  90  are coupled to each other, the extension portion  20   b  may be coupled to abut an inner circumferential surface of the outer rib  96 . 
     This is to maintain an airtightness between each of the components when the drain tray  90  and the upper housing  20  are coupled to each other so that the discharged airflow may be prevented from being leaked to the outside of the upper housing  20  and to form an external water collecting space  99   b  which will be described later. 
     That is, by the extension portion  20   b  and the outer rib  96 , upper housing  20  and the drain tray  90  are coupled to each other in a state in which a bottom surface of the extension portion  20   b  and the top surface  90   a  of the drain tray  90  abut each other and an outer circumferential surface of the extension portion  20   b  and the inner circumferential surface of the outer rib  96  abut each other, so that a double-sealing effect may be generated. 
     An inner rib  97  that is disposed radially inside of the outer circumferential surface  20   a  of the upper housing  20  and protrudes upward may be provided in the top surface  90   a  of the drain tray  90 . 
     A heat insulating material  19  may be disposed on the inner circumferential surface of the upper housing  20  in order to prevent heat exchange efficiency from being reduced due to a difference between cold air in the discharge flow passage  36  and the indoor temperature outside the upper housing  20  and to prevent condensate water from being generated on the outer surface of the housing  10  due to a temperature difference between the inside and outside of the housing  10 . In addition, the heat insulating material  19  may be additionally disposed at a lower side of the drain tray  90 . 
     Here, the inner rib  97  may be provided to abut a lower side of the heat insulating material  19  in order to maintain an airtightness between the heat insulating material  19  and the upper housing  20  and between the heat insulating material  19  and the drain tray  90 . Accordingly, when the heat insulating material  19  and the drain tray  90  are coupled to each other, an outer circumferential surface of the inner rib  97  and an inner peripheral surface of the heat insulating material  19  as well as a lower surface of the heat insulating material  19  and the top surface  90   a  of the drain tray  90  may be additionally sealed, and therefore the airtightness may be maintained when coupling between the upper housings  20 , thereby minimizing the leakage of the discharged airflow. 
     That is, the drain tray  90  includes the inner rib  97  and the outer rib  96  which are respectively formed radially inside and outside of the heat insulating material  19  and the upper housing  20 , so that the drain tray  90  may doubly abut to couple to the heat insulating material  19  and the upper housing  20 , and a double-sealing effect in which the airtightness is maintained may be generated. 
       FIG.  15    shows a coupling structure of the drain tray  90  and the upper housing  20  according to still another embodiment of the present invention, and a coupling rib  98  that protrudes upward may be further formed between the inner rib  97  and the outer rib  96 . 
     The coupling rib  98  may be inserted into the lower surface of the heat insulating material  19  so that an additional sealing effect between the heat insulating material  19  and the drain tray  90  may be generated. 
     The coupling rib  98  is not limited to an example of  FIG.  15    and may be disposed at a side to which the upper housing  20  is coupled and inserted into a lower surface of the upper housing  20 . Accordingly, the coupling rib  98  may generate an additional sealing effect between the upper housing  20  and the drain tray  90 . 
     Condensate water is collected in the drain tray  90  as described above, and the drain extraction unit  94  may be disposed in the drain tray  90  in order to discharge the collected condensate water to the outside of the indoor unit  1  of the air conditioner. 
     A water collecting unit  99  in which the condensate water is collected may be disposed at a side in which the drain extraction unit  94  is disposed. The condensate water generated from the heat exchanger  80  is dropped downward and collected on the drain tray  90 , and in this instance, the condensate water may be collected in the water collecting unit  99  by a gradient formed on the top surface  90   a  of the drain tray  90 . 
     The condensate water collected in the water collecting unit  99  may be discharged to the outside of the indoor unit  1  of the air conditioner by the drain extraction unit  94 . 
     The condensate water may be generated from the outer circumferential surface  20   a  of the upper housing  20  as well as the heat exchanger  80 . This is because a part of the discharge flow passage  36  that is a section in which cold air is discharged is formed on the inner circumferential surface of the upper housing  20  and the outer circumferential surface  20   a  of the upper housing  20  is exposed to the indoor temperature, so that a temperature difference between the inside and outside of the upper housing  20  is generated. 
     As described above, the heat insulating material  19  is disposed on the inner circumferential surface of the upper housing  20  in order to prevent this, but when the indoor temperature is high, the condensate water may be generated on the outer circumferential surface  20   a  of the upper housing  20  due to a large temperature difference between the inside and outside of the upper housing  20 . 
     The condensate water generated on the outer circumferential surface  20   a  may drop into the interior space and thereby may degrade the reliability of the air conditioner. However, since the air conditioner according to an embodiment of the present invention includes the external water collecting space  99   b  formed by the above-described outer rib  96  and extension portion  20   b,  this may be prevented. 
     Specifically, a space formed by one side of the outer circumferential surface  20   a,  the extension portion  20   b,  and the inner circumferential surface of the outer rib  96  may be provided as the external water collecting space  99   b  that can collect the condensate water dropped along the outer circumferential surface  20   a,  thereby preventing the condensate water generated from the outside from dripping into the interior space (see  FIG.  14   ). 
     That is, the concave shape external water collecting space  99   b  is disposed at the bottom side of the upper housing  20 , so that the condensate water dropped downward along the outer circumferential surface  20   a  of the upper housing  20  is collected in the external water collecting space  99   b  rather than the interior space. 
     As shown in  FIG.  16   , an incised portion  20   c  may be provided at one side of the upper housing  20  in order to prevent the condensate water collected in the external water collecting space  99   b  from overflowing to the outside. In  FIG.  16   , for convenience of description, components except for the heat insulating material  19  are shown. 
     Specifically, by moving the condensate water collected in the external water collecting space  99   b  to the water collecting unit  99 , the condensate water on the external water collecting space  99   b  may be prevented from dripping outside. 
     The incised portion  20   c  is a space obtained by cutting one side of the extension portion  20   b.  Here, a slightly separated space may be generated between the upper housing  20  and the drain tray  90  at a side in which the extension portion  20   b  is not disposed, and the condensate water generated from the outside may flow into the upper housing  20  by passing through the outer circumferential surface  20   a  of the upper housing  20  and the heat insulating material  19  through the separated space and then flow into the water collecting unit  99 . 
     Preferably, the incised portion  20   c  may be disposed at a position corresponding to a position in which the external water collecting space  99   b  is disposed. This is to prevent the condensate water flowed into the drain tray  90  through the incised portion  20   c  from flowing to spaces other than the external water collecting space  99   b.    
     Accordingly, the condensate water collected in the external water collecting space  99   b  may flow into the drain tray  90  without dropping outside. 
     In addition, although not shown, a sealing member may be disposed between the upper housing  20  and the drain tray  90 , so that the airtightness of the upper housing  20  and the drain tray  90  may be improved. 
     In this case, the sealing member may block the flow of air flowing between the upper housing  20  and the drain tray  90  and at the same time, make the water collected in the external water collecting space  99   b  move to the water collecting unit  99  through the sealing member. 
     Specifically, the sealing member may be formed of a member capable of absorbing moisture and make the condensate water flow to a side of the inner circumferential surface of the upper housing  20  by absorbing the condensate water collected in the external water collecting space  99   b,  so that the condensate water flowing into the upper housing  20  may flow to the water collecting unit  99  by the gradient. 
     Accordingly, when the sealing member is disposed, the water collected in the external water collecting space  99   b  may flow to the water collecting unit  99  even without a separate incised portion  20   c,  such that the upper housing  20  may not include the incised portion  20   c.    
     Hereinafter, a wire insertion unit disposed in the upper housing will be described in detail. 
     As shown in  FIG.  17   , a wire insertion unit  26  in which a wire for electrically connecting components (the drain pump  92 , etc.) disposed inside the housing  10  is inserted may be provided at one side of the upper housing  20 . 
     When the wire is disposed inside the housing in the case of the conventional air conditioner, the air conditioner has been assembled in the sequence in which the wire is disposed outside the housing in order to assemble the drain tray, the drain tray and the heat insulating material are assembled, and then the wire is disposed inside the housing. 
     When the wire is disposed after the heat insulating material is assembled, the inside of the housing is surrounded by the heating insulating material, the wire is temporarily fixed and disposed using a component such as a separate tape due to the absence of a component such as a hook capable of supporting the wire, and then an operation of electrically connecting the internal components is performed. At this point, a problem of an increased failure rate may occur caused by an unnecessary component added in the process of fixing the wire and the complicated operation. 
     In order to solve this, in the air conditioner according to an embodiment of the present invention, the wire insertion unit  26  is formed at one side of the upper housing  20 , so that the wire may be inserted into the wire insertion unit  26  before assembling the drain tray  90  and the heat insulating material  19 . 
     Accordingly, the heat insulating material  19  may be assembled in a state in which the wire is disposed inside the housing  10 , so that an additional operation in which the wire is disposed outside, the heat insulating material  19  is assembled, and then the wire is disposed inside may be omitted. 
     That is, the wire insertion unit  26  may secure a space that protrudes in the radial direction of the upper housing  20  from one side of the upper housing  20  and thereby may fix the wire on the inner circumferential surface of the upper housing. 
     In addition, the wire is fixed on the inner circumferential surface of the upper housing  20 , so that the corresponding operation may be easily performed without the interference of the wire when the drain tray  90  and the heat insulating material  19  are assembled, and the wire insertion unit  26  may include a removal prevention hook  26   a  for preventing the removal of the wire from the wire insertion unit  26  and a fixing rib  26   b  for preventing the wire from being laterally pushed to the side. 
     Accordingly, when the internal components are assembled, the wire may be fixed in the wire insertion unit  26 , so that an additional operation of temporarily fixing the wire using a tape may be omitted. 
     Hereinafter, a hook coupling between the lower housing  30  and the drain tray  90  will be described in detail. 
     In the indoor unit  1  of the air conditioner, the lower housing  30 , the intermediate housing  21 , the drain tray  90 , and the upper housing  20  may be coupled to one another by a coupling member  200  which will be described later. In this case, when the coupling member  200  is disassembled, a problem occurs where each of the components is easily separated. 
     In particular, in the case of a ceiling-embedded type air conditioner according to an embodiment of the present invention, when the indoor unit  1  of the air conditioner is disassembled due to a malfunction of the air conditioner or the like, a user who disassembles the components may be injured by the dropping of the components caused by each of the components that are easily separated. 
     In order to solve this, the indoor unit  1  of the air conditioner according to an embodiment of the present invention may include a coupling hook to which each of the components can be temporarily coupled even when the coupling member  200  is disassembled, as shown in  FIG.  18   . 
     Specifically, a coupling hook  38  and a latched jaw may be provided between the lower housing  30  and the drain tray  90 . A plurality of coupling hooks  38  that protrude to a side of the drain tray  90  may be disposed on the outer circumferential surface of the lower housing  30 , and the latched jaw may be disposed in a position corresponding to the coupling hook  38  of the drain tray  90 . The coupling hook  38  and the latched jaw may be disposed vice versa. 
     According to an embodiment of the present invention, the coupling hook  38  may protrude from and be provided on the outer circumferential surface of the outer first lower housing  31   a  but, without being limited thereto, may be provided in any location of the lower housing  30  disposed at a side adjacent to the drain tray  90  so that the lower housing  30  and the drain tray  90  are easily hook-coupled to each other. 
     In the air conditioner  1  according to an embodiment of the present invention, the intermediate housing  21  is disposed between the lower housing  30  and the drain tray  90 , so that in a case in which a hook coupling is achieved only between the lower housing  30  and the drain tray  90 , the intermediate housing  21  may be supported by the lower housing  30  and may not drop even when the coupling member  200  is removed. 
     However, unlike an embodiment of the present invention, an additional coupling hook may be provided even in the intermediate housing  21  so that the intermediate housing  21  may be hook-coupled to the lower housing  30  or the drain tray  90 , and the intermediate housing  21  can be seen as a single component of the lower housing  30  as described above, and therefore it is obvious that the coupling hook coupled to the drain tray  90  may be provided even in the intermediate housing  21 . 
     Hereinafter, characteristics in which the components of the indoor unit of the air conditioner are assembled by the coupling member  200  will be described. 
     Referring to  FIG.  1   , a cover member  18  that covers an exterior portion of the lower housing  30  may be disposed at a bottom side of the indoor unit  1  of the air conditioner. An auxiliary cover member  18   a  that is detachably disposed on the cover member  18  may be provided at four corners of the cover member  18 . 
     In the indoor unit  1  of the air conditioner, the cover member  18 , the lower housing  30 , the intermediate housing  21 , the drain tray  90 , and the upper housing  20  are disposed sequentially layered on one another and coupled. 
     In the case of a conventional air conditioner, particularly, in the case of an air conditioner that generally controls the discharged airflow with a blade, the cover member, the drain tray, and the housing may be sequentially layered on one another and coupled, but the air conditioner according to an embodiment of the present invention may include the airflow controller provided at the lower side of the drain tray instead of including a blade, so that the number of components that are additionally layered and disposed such as the lower housing  30  and the intermediate housing  21  or the lower housing  30  including a plurality of components may be increased compared to the conventional air conditioner and result in a problem with the coupling between each of the components. 
     In particular, when the layered components are assembled, the assembling may be difficult due to the increased number of the layered components, and each of the components may be mainly formed as injection-molded products having plastic properties, and therefore the respective components may be damaged by contact caused by even a small impact when the components are assembled, resulting in a reduction in the durability of the indoor unit  1  of the air conditioner. 
     Accordingly, as shown in  FIGS.  19  and  20   , in order to solve this, each of the components may be coupled to the coupling member  200  which is coupled to the outer circumferential surface of the indoor unit  1  of the air conditioner rather than being coupled to one another, thereby improving the durability. 
     The coupling member  200  may be screw-coupled to each of the layered components while extending in the vertical direction of the outer circumferential surface of the indoor unit  1  of the air conditioner and include a material having a high strength such as steel. 
     At least a part of the coupling member  200  may include an insertion portion  209  that is inserted into the upper housing  20  and extend in the vertical direction. The insertion portion  209  may extend in the vertical direction inside the upper housing  20  and be fixed inside the upper housing  20 . 
     The coupling member  200  may be exposed to the outside by extending outside of the upper housing  20  from the lower side of the upper housing  20 . At the position where the coupling member  200  is exposed to the outside, a coupling portion  210  in which the drain tray  90 , the lower housing  30 , and the cover member  18  are coupled to one another may be provided. In addition, a connection portion  211  that extends to connect the insertion portion  209  and the coupling portion  210  may be provided between the insertion portion  209  and the coupling portion  210 . 
     The coupling portion  210  may be screw-coupled to a first assembling unit  91  that protrudes outside of the outer circumferential surface from the outer perimeter side of the drain tray  90 , a second assembling unit  39  that protrudes outside of the outer circumferential surface of the lower housing  30 , and a screw hole (not shown) that is disposed in the cover member in a state in which they are layered. 
     In addition, although not shown, an additional assembling unit that protrudes outside of the outer circumferential surface of the intermediate housing  21  may be disposed between the first assembling unit  91  and the second assembling unit  39 , so that the additional assembling unit may be screw-coupled to the first assembling unit  91  and the second assembling unit  39  in a state in which they are layered. 
     As shown in  FIG.  19   , three screw fastening holes may be provided in the coupling portion  210 , and three screws may be screwed into the three screw fastening holes, so that the first assembling unit  91 , the second assembling unit  39 , and the cover member  18  may each be coupled. 
     In addition, a bolt coupling portion  220  that extends from the inserted coupling member  200  may penetrate one side of the upper housing  20 . A fully threaded bolt coupled to one side of the ceiling may be coupled to the bolt coupling portion  220  so that the indoor unit  1  of the air conditioner may be embedded in the ceiling and supported at one side of the ceiling. Specifically, the bolt coupling portion  220  may extend radially outside of the upper housing  20  from the insertion portion  209 , and thereby may protrude outside of the upper housing  20 . The insertion portion  209  may extend in the axial direction of the upper housing  20  as described above, whereas the bolt coupling portion  220  may extend in the radial direction of the upper housing  20 . 
     The bolt coupling portion  220  may include a steel member, and preferably, the bolt coupling portion  220  may be integrally formed with the coupling member  200  having a high strength as shown in an embodiment of the present invention and inserted into the upper housing  20 . 
     The insertion portion  209  and the coupling portion  210  may be connected to each other through the connection portion  211 . The connection portion  211  may be bent from the axial direction of the upper housing  20  in which the insertion portion  209  extends to the radial direction and extend outside of the upper housing  20 . 
     The connection portion  211  may pass through the upper housing  20  and extend to the outside while passing through the bottom of the upper housing  20 . 
     The connection portion  211  may extend to an outer side in the radial direction of the drain tray  90 . This is because the radius of the outer circumferential surface of the drain tray  90  is provided larger than the radius of the outer circumferential surface of the upper housing  20  as described above. 
     The connection portion  211  that extends to the outer side in the radial direction of the drain tray  90  may be bent toward the axial direction of the upper hosing  20  again and extend along the axial direction of the upper housing  20 . In other words, the connection portion  211  may be primarily bent toward radially outside of the upper housing  20  from the insertion portion  209  that extends in the vertical direction, extend to the outer side in the radial direction of the drain tray  90 , and then bent in the vertical direction again. 
     The connection portion  211  that is bent in the vertical direction may extend downward up to a side at which the first assembling unit  91  is disposed and be bent to be connected to the coupling portion  210 . 
     In summary, the coupling member  200  may include a first portion (the insertion portion  209 ) where at least a part of the coupling member  200  is inserted into the upper housing  20  and fixedly coupled inside the upper housing  20 , a second portion (the coupling portion  210 ) where the drain tray  90 , the lower housing  30 , and the cover member  18  are layered and coupled, and a third portion (the connection portion  211 ) that connects the first portion  209  and the second portion  210 . 
     The first portion  209  is a section which extends in the axial direction of the upper housing  20  and is inserted into the upper housing  20 , the second portion  210  is a section which extends radially outside of the upper housing  20  to couple the drain tray  90 , the lower housing  30 , and the cover member  18 , and the third portion  211  is a section that connects the first portion  209  and the second portion  210 . Here, the third portion  211  may first be bent in the radial direction of the upper housing  20  from the first portion  209 , extend up to the radius of the drain tray  90 , bent again in the axial direction of the upper housing  20 , and then extend to the second portion  210 . 
     However, without being limited to an embodiment of the present invention, the coupling member  200  may be screw-coupled to the upper housing  20  outside the upper housing  20  while extending in the vertical direction of the outer circumferential surface of the upper housing  20  without being inserted into the upper housing  20 . 
     Hereinafter, an opening and closing unit  300  of an air conditioner according to yet another embodiment of the present invention shown in  FIGS.  21  to  26    will be described. Components other than the opening and closing unit  300  to be descried below may be the same as those of the above-described air conditioner  1  according to an embodiment of the present invention, and thus repeated description thereof will be omitted. 
     In the above-described air conditioner  1  according to an embodiment of the present invention, a blade is not disposed at a side of the discharge port  33 . Thus, the discharge port  33  is disposed in a state of being always opened to the outside, so that external substances such as dust may be introduced into the housing  10  through the discharge port  33  when the air conditioner is not operated, and therefore component such as the heat exchanger  80  that is disposed inside the housing  10  may be contaminated. 
     That is, in the case of the conventional air conditioner, when the air conditioner is not operated, the blade closes the discharge port and restricts the external substances from entering the discharge port, but according to an embodiment of the present invention, a component similar to the blade is not disposed at the side of the discharge port  33 , so that there is no component capable of restricting ingress of the external substances. 
     In order to solve this, the air conditioner  1  according to yet another embodiment of the present invention shown in  FIGS.  21  to  26    may include an opening and closing unit  300  at the side of the discharge port  33  that closes the discharge port  33  when the air conditioner  1  is not operated and opens the discharge port  33  only when the air conditioner  1  is operated. 
     The opening and closing unit  300  may slidably move in inward and outward directions corresponding to the radial direction of the first lower housing  31  in a space between the inner circumferential surface of the outer first lower housing  31   a  that forms the discharge port  33  and the outer circumferential surface of the inner first lower housing  31   b,  thereby opening and closing the discharge port  33 . 
     The opening and closing unit  300  may include an opening and closing plate  310  with a first length corresponding to a separation distance between the inner circumferential surface of the outer first lower housing  31   a  and the outer circumferential surface of the inner first lower housing  31   b  and a second length corresponding to a circumferential direction of the discharge port  33  and include a sliding extension portion  320  that extends from one side of the opening and closing plate  310  so that the opening and closing plate  310  may be slidably moved. 
     The opening and closing plate  310  may be provided to have a size corresponding to the discharge port  33  as described above and slidably moved in the radial direction of the first lower housing  31  to open and close the discharge port  33 . 
     Specifically, the opening and closing plate  310  may be provided to be positioned radially inside of the inner first lower housing  31   b  in order to maintain an open state of the discharge port  33  when the air conditioner  1  is operated as shown in  FIG.  22   . 
     When the air conditioner is not operated, the opening and closing plate  310  may pass through the outer circumferential surface of the inner first lower housing  31   b  through a through-hole  31   b ′ provided in the inner first lower housing  31   b,  be slidably moved in the radial direction of the inner first lower housing  31   b,  and then reach a side of the inner circumferential surface of the outer first lower housing  31   a,  as shown in  FIG.  23   . 
     By slidably moving the opening and closing plate  310  between the inner circumferential surface of the outer first lower housing  31   a  and the outer circumferential surface of the inner first lower housing  31   b  as shown in  FIG.  24   , the discharge port  33  may be opened and closed. 
     As shown in the drawing, the air conditioner includes three discharge ports  33 , so that three opening and closing plates  310  may be provided to correspond to the number of the discharge ports  33 . However, without being limited thereto, the opening and closing plate  310  may be provided by the number corresponding to the number of the discharge ports  33  when the number of the discharge ports  3  of the air conditioner is less or greater than  3 . 
     The opening and closing unit  300  may include a sliding driving motor  330  that slidably moves the opening and closing plate  310  and a pinion gear  340  that transfers a rotational force of the sliding driving motor  330 . 
     The sliding extension portion  320  may be provided to extend toward the center of the first lower housing  31  from the opening and closing plate  310 . A rack portion  342  that is disposed to be engaged with the pinion gear  340  may be provided at one side of the sliding extension portion  320 . 
     Accordingly, as the sliding driving motor  330  is driven, the pinion gear  340  and the rack portion  342  may be engaged with each other, and the sliding extension portion  320  may slidably reciprocate in the radial direction of the first lower housing  31  due to the linear motion of the rack portion  342 . The opening and closing plate  310  may be slidably moved between the discharge ports  33  in conjunction with the sliding extension portion  320 . 
     A sliding slit  341  into which a guide protrusion  350  protruding downward from the intermediate housing  21  is inserted may be provided at a center portion of the sliding extension portion  320  to guide the reciprocating motion of the sliding extension portion  320 . 
     When slidably moving, due to the guide protrusion  350  inserted into the sliding slit  341 , the sliding extension portion  320  may linearly reciprocate without being detached. 
     As shown in  FIGS.  25  and  26   , the opening and closing unit  300  may be coupled to the intermediate housing  21 . That is, the sliding driving motor  330 , the pinion gear  340 , and the guide protrusion  350  are supported by the lower surface of the intermediate housing  21 , and the opening and closing plate  310  may be disposed at a side corresponding to each of the components and slidably moved. However, without being limited thereto, the opening and closing unit  300  may be disposed in the first lower housing  31  and supported. 
     As shown in  FIG.  25   , when the opening and closing unit  300  is opened, due to opening all of the openings of the intermediate housing  21 , air moving to the discharge port  33  and discharging to the outside of the housing  10  is not limited. 
     In addition, as shown in  FIG.  26   , when the opening and closing unit  300  is closed, foreign substances may be prevented from entering the discharge port  33  that communicates with the inside of the housing  10  by closing all of the openings of the intermediate housing  21 . 
     Hereinafter, an opening and closing unit  400  of an air conditioner according to yet another embodiment of the present invention which is shown in  FIGS.  27  to  31    will be described. Components other than the opening and closing unit  400  to be descried below may be the same as those of the above-described air conditioner  1  according to an embodiment of the present invention, and thus repeated description thereof will be omitted. 
     As shown in yet another embodiment of the present invention shown in  FIGS.  21  to  26    described above, the opening and closing unit  400  may be moved between the inner circumferential surface of the outer first lower housing  31   a  and the outer circumferential surface of the inner first lower housing  31   b,  and thereby may open and close the discharge port  33 . 
     The opening and closing unit  400  may include an opening and closing plate  410  whose one side is rotatably fixed, a rotation driving motor  430  that transfers rotational force to rotate the opening and closing plate  410 , and a rotating shaft  420  that transfers the rotational force of the rotation driving motor  430  to the opening and closing plate  410 . 
     The rotating shaft  420  may be disposed at one side of the opening and closing plate  410  so that the opening and closing plate  410  may be rotated in the direction from the outer circumferential surface of the inner first lower housing  31   b  to the inner circumferential surface direction of the outer first lower housing  31   a  or in the opposite direction with respect to the rotating shaft. 
     As shown in  FIG.  28   , when the air conditioner  1  is not operated, the opening and closing plate  410  may pass through a through-hole  31   b ′ of the inner first lower housing  31   b  and be rotated toward the inner circumferential surface of the outer first lower housing  31   a  from the outer circumferential surface of the inner first lower housing  31   b,  thereby closing the discharge port  33 . 
     In addition, as shown in  FIG.  29   , when the air conditioner  1  is operated, the opening and closing plate  410  may be rotated toward the inner first lower housing  31   b  from the inner circumferential surface of the outer first lower housing  31   a  with respect to the rotating shaft  420 , pass through the inner first lower housing  31   b  through the through-hole  31   b ′, and be rotated to an inner side in the radial direction of the inner first lower housing  31   b.    
     Accordingly, the opening and closing plate  410  may be located radially inside of the discharge port  33  and disposed not to restrict the flow of air discharged through the discharge port  33 . 
     As shown in  FIG.  30   , the opening and closing unit  400  may be disposed to be supported by the intermediate housing  21 . Specifically, the rotation driving motor  430  may be coupled to the lower surface of the intermediate housing  21 , and the rotating shaft  420  of the opening and closing plate  410  may be coupled to the rotation driving motor  430 . However, without being limited to yet another embodiment of the present invention, the opening and closing unit  400  may be disposed in the first lower housing  31  and supported. 
     As shown in  FIG.  30   , when the opening and closing unit  400  is opened, due to opening all of the openings of the intermediate housing  21 , air moving to the discharge port  33  and discharging to the outside of the housing  10  is not limited. 
     In addition, as shown in  FIG.  31   , when the opening and closing unit  400  is closed, foreign substances may be prevented from entering the housing  10  by closing the discharge port  33  that communicates with the inside of the housing  10 . 
     Hereinafter, an opening and closing unit  500  of an air conditioner according to yet another embodiment of the present invention which is shown in  FIGS.  32  to  35    will be described. Components other than the opening and closing unit  500  to be descried below may be the same as those of the above-described air conditioner  1  according to an embodiment of the present invention, and thus repeated description thereof will be omitted. 
     As shown in yet another embodiment of the present invention shown in  FIGS.  21  to  26    described above, the opening and closing unit  500  may be moved between the inner circumferential surface of the outer first lower housing  31   a  and the outer circumferential surface of the inner first lower housing  31   b,  and thereby may open and close the discharge port  33 . 
     For this, the opening and closing unit  500  may include an opening and closing plate  510  that opens and closes the discharge port  33  by a sliding movement, a rotation frame  530  that slidably moves the opening and closing plate  510  by rotation, a rotation driving motor  550  that transfers a rotational force to the rotation frame  530 , and a fixed frame  540  in which the rotation driving motor  550  is fixed. 
     A sliding extension portion  520  which is provided to allow the opening and closing plate  510  to be slidably moved may extend from one side of the opening and closing plate  510 . In the sliding extension portion  520 , a sliding protrusion  521  that is inserted into a rail  531  of the rotation frame  530  and moved in conjunction with the movement of the rail  531  when the rotation frame  530  is rotated, and a sliding slit  522  that makes the sliding extension portion  520  linearly reciprocate may be provided. 
     The sliding slit  522  may extend to have a length portion in a direction corresponding to the radial direction of the first lower housing  31 . A guide protrusion  560  that extends downward from the intermediate housing  21  may be inserted into the sliding slit  522  and thereby guide the sliding extension portion  520  so that the sliding extension portion  520  may be moved linearly. 
     The rotation frame  530  may be coupled to the rotation driving motor  550  to receive the rotational force by the rotation driving motor  550  and be rotated in one direction or in the opposite direction. 
     The rotation frame  530  may be coupled to a center portion of the intermediate housing  21  and disposed in a flow passage through which air is introduced to the blower fan  40  by the suction port  11 , and therefore the rotation frame  530  may be provided in the form of a grille with a minimized surface area to prevent the air introduced by the rotation frame  530  from being restricted. 
     The rotation frame  530  may include the rail  531  having a curved line that extends in the radial direction and is bent to one side. The rail  531  may be provided in a number corresponding to the number of the opening and closing plates  510 . 
     According to yet another embodiment of the present invention shown in  FIGS.  32  to  35   , three discharge ports  33  may be provided, three opening and closing plates  510  may be provided to correspond to the number of the discharge ports  33 , and three rails  531  may be formed corresponding to the opening and closing plates  510 . 
     A rotating shaft  532  that is connected to the rotation driving motor  550  to transfer a rotational force to the rotation frame  530  may be provided at the center portion of the rotation frame  530 . The rotation frame  530  may be rotated in one side or in the opposite direction with respect to the rotating shaft  532 . 
     A support frame  540  that supports the rotation driving motor  550  and the rotation frame  530  coupled to the rotation driving motor  550  may be provided at the center portion of the intermediate housing  21 . The support frame  540  may be provided at the center portion of the intermediate housing  21  and disposed in the flow passage through which air is introduced in the same manner as in the rotation frame  530 , and therefore the support frame  540  may be formed with a minimized surface area so that interference with the air is minimized. 
     As shown in  FIG.  33   , the opening and closing plate  510  may be provided to pass through the inner first lower housing  31   b  through the through-hole  31   b ′ of the inner first lower housing  31   b.  In addition, the sliding protrusion  521  may be provided inserted in the rail  531 . 
     As shown in  FIG.  34   , when the rotation frame  530  is rotated to one side, the rail  531  may be rotated to one side, and in conjunction with the rotation of the rail  531 , the sliding protrusion  521  may be moved in a direction in which the rail  531  is rotated along the rail  531 . 
     The sliding extension portion  520  may be moved in conjunction with the movement of the sliding protrusion  521  and make linearly reciprocating movements in the radial direction of the first lower housing  31  guided by the guide protrusion  560  inserted in the sliding slit  522 . 
     The sliding slit  522  may extend in the direction corresponding to the radial direction of the first lower housing  31  as described above, and therefore the sliding protrusion  521  may be guided by the guide protrusion  560  inserted in the sliding slit  522  even when the sliding protrusion  521  is rotated along the rail  531  and thereby may make reciprocating movements only in the inward and outward directions along the radial direction of the first lower housing  31 . 
     Accordingly, when the rotation frame  530  is rotated to one side, the sliding extension portion  520  may be moved toward the inner circumferential surface of the outer first lower housing  31   a  from the outer circumferential surface side of the inner first lower housing  31   b,  while the sliding protrusion  521  is moved along the rail  531  in conjunction with the rotation of the rail  531  and moved toward radially outside of the rotation frame  530  in the radial direction of the rotation frame  530 . 
     Thus, the opening and closing plate  510  may pass through the through-hole  31   b ′ of the inner first lower housing  31   b  in conjunction with the movement of the sliding extension portion  520  and be slidably moved to the inner circumferential surface side of the outer first lower housing  31   a.    
     Accordingly, the opening and closing plate  510  may be disposed at the discharge port  33  to close the discharge port  33  and prevent foreign substances from being introduced into the discharge port  33 . 
     On the other hand, when the rotation frame  530  is rotated in the opposite direction, the sliding protrusion  521  may be moved along the rail  531  in conjunction with the rotation of the rail  531  in the opposite direction as shown in  FIG.  35   . 
     The sliding protrusion  521  may be moved toward the center of the rotation frame  530  by the rotation direction of the rail  531  and the guide protrusion  560 , and the sliding extension portion  520  may be moved from the inner circumferential surface side of the outer first lower housing  31   a  toward the inner first lower housing  31   b.    
     Accordingly, the opening and closing plate  510  may pass through the through-hole  31   b ′ of the inner first lower housing  31   b  in conjunction with the movement of the sliding extension portion  520  and be slidably moved to an inner side in the radial direction of the inner first lower housing  31   b.    
     Thus, the opening and closing plate  510  may be positioned inside the inner first lower housing  31   b  and open the discharge port  33 , so that air may flow to the discharge port  33 . 
     Hereinafter, an opening and closing unit  600  of an air conditioner according to yet another embodiment of the present invention shown in  FIGS.  36  and  37    will be described. Components other than the opening and closing unit  600  to be descried below may be the same as those of the above-described air conditioner  1  according to an embodiment of the present invention, and thus repeated description thereof will be omitted. 
     As shown in yet another embodiment of the present invention shown in  FIGS.  21  to  26    described above, the opening and closing unit  600  may be moved between the inner circumferential surface of the outer first lower housing  31   a  and the outer circumferential surface of the inner first lower housing  31   b  and thereby may open and close the discharge port  33 . 
     The opening and closing unit  600  may include an opening and closing plate  610  that opens and closes the discharge port  33 , a sliding protrusion  620  that protrudes from one side of the opening and closing plate  610  so that the opening and closing plate  610  may be slidably moved, a rotating disk  630  that makes the sliding protrusion  620  move through its rotation, and a rotation driving motor  640  that transfers a rotational force to the rotating disk  630 . 
     The rotating disk  630  may include a sliding slit  632  into which the sliding protrusion  620  is inserted and extends in one direction so that the sliding protrusion  620  may perform a translation motion and a rotating shaft  631  that is connected to the rotation driving motor  640  to rotate the rotating disk  630 . 
     As shown in yet another embodiment of the present invention shown in  FIGS.  32  to  36    described above, as the rotating disk  630  is rotated with respect to the rotating shaft  631 , the sliding slit  632  may be rotated in conjunction with the rotation of the rotating disk  630 , so that the sliding protrusion  620  inserted in the sliding slit  632  may be slidably moved along a direction in which the sliding slit  632  extends. 
     Thus, in conjunction with the slidable movement of the sliding protrusion  620 , the opening and closing plate  610  may open and close the discharge port  33  while being slidably moved between the outer first lower housing  31   a  and the inner first lower housing  31   b.    
     When the rotating disk  630  is rotated to one side as shown in  FIG.  36   , the sliding slit  632  may be rotated in conjunction with the rotating disk  630 , and the sliding protrusion  620  inserted in the sliding slit  632  may be moved in conjunction with the rotation of the sliding slit  632 . 
     In this case, the sliding protrusion  620  may be moved along the extension direction of the sliding slit  632 , and when the sliding protrusion  620  is slidably moved in the sliding slit  632  toward one side adjacent to the circumference side of the rotating disk  630 , the opening and closing plate  610  may be slidably moved in the radially outside direction of the intermediate housing  30   a  in conjunction with the sliding protrusion  620  and thereby may be disposed at the discharge port  33  to close the discharge port  33 . 
     On the other hand, when the rotating disk  630  is rotated in the opposite direction as shown in  FIG.  37   , the sliding protrusion  620  may be slidably moved toward the other side of the sliding slit  632  along the sliding slit  632 . 
     In this case, the opening and closing plate  610  may be slidably moved in the radially inside direction of the intermediate housing  21  in conjunction with the sliding protrusion  620  and thereby may be disposed radially inside of the discharge port  33  to open the discharge port  33 . 
     As described above, according to the embodiments of the present invention, some of internal components in the indoor unit of the air conditioner formed in the circular shape may be disposed in the protrusion portion protruding from the circular housing and thereby maximize the discharge port, and the protrusion directions of the protrusion portion may coincide with each other and thereby facilitate the installation of the air conditioner. 
     In addition, components of the indoor unit of the air conditioner may be coupled to one another by the coupling member, thereby improving the durability of the indoor unit of the air conditioner. 
     In addition, a discharge port that is regularly disposed by an appropriate arrangement of the components in the housing may be realized, thereby generating uniform airflow in a room. 
     In addition, a condensate water collecting space that is disposed outside the housing may be provided in the drain tray, thereby preventing a leakage due to condensate water generated outside the housing. 
     In addition, by the opening and closing unit provided at a position corresponding to the discharge port, the discharge port of the air conditioner may be easily opened and closed even without a blade formed inside the housing of the air conditioner. 
     Although a few embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.