Patent Publication Number: US-11035601-B2

Title: Refrigerator

Description:
RELATED APPLICATION(S) 
     This application claims the benefit of Korean Patent Application No. 10-2015-0028610, filed on Feb. 27, 2015 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
     BACKGROUND 
     Embodiments of the present disclosure relate to a refrigerator having an ice-making tray which stores ice-making water, cools the ice-making water, and generates ice. 
     In general, a refrigerator is an apparatus that includes storage chambers and a cold air supply unit that supplies cold air to the storage chambers, and stores food freshly. A refrigerator may further include an ice-making chamber and an ice-making apparatus for generating ice. 
     An automatic ice-making apparatus includes an ice-making tray that stores ice-making water, an ejector that separates ice made by the ice-making tray, an ice-ejecting heater that heats the ice-making tray when the ice is separated from the ice-making tray, and an ice bucket that stores the ice separated from the ice-making tray. 
     Among ice-making methods for cooling ice-making water, a direct cooling method has a refrigerant pipe provided to extend inside an ice-making chamber for cooling ice-making water and to be in contact with an ice-making tray. In such a direct cooling method, an ice-making tray receives cooling energy from a refrigerant pipe by thermal conduction. Accordingly, the direct cooling method has a merit in that a cooling speed of ice-making water is fast. However, when the cooling speed of ice-making water is excessively fast, ice that is not transparent and is turbid is generated. 
     SUMMARY 
     Therefore, it is an aspect of the present disclosure to provide an ice-making tray capable of generating ice of which transparency is improved by decreasing conductivity of cooling energy slightly, and a refrigerator having the same. Here, the ice-making tray is in contact with a refrigerant pipe, receives a cooling energy from the refrigerant pipe by thermal conduction, and generates ice. At this time, the efficiency of a cooling function of an ice-making chamber by the ice-making tray, that is, the function in which the ice-making tray cools the ice-making chamber while exchanging heat with air in the ice-making chamber, does not decrease. 
     It is another aspect of the present disclosure to provide an integrated ice-making tray in which the ice-making tray and related parts of the ice-making tray are integrated. 
     It is still another aspect of the present disclosure to provide an ice-making tray having an improved structure capable of fixing a position of a temperature sensor which measures temperature of water or ice accommodated in an ice-making cell. 
     It is yet another aspect of the present disclosure to provide a refrigerator having an improved structure in which a drain duct rotatably coupled to an ice-making tray rotates in a predetermined range. 
     It is yet another aspect of the present disclosure to provide a refrigerator having an improved structure in which cooling energy transferred from a refrigerant pipe uniformly transfers to an ice-making tray. 
     It is yet another aspect of the present disclosure to provide a refrigerator having an improved structure capable of preventing an ice-ejecting motor coupled to an ice-making tray from sagging. 
     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, a refrigerator includes a main body, an ice-making chamber formed inside the main body, an ice-making tray installed inside the ice-making chamber, wherein ice-making water is stored and ice is generated in the ice-making tray, and a refrigerant pipe installed so that at least a part thereof is in contact with the ice-making tray, wherein a refrigerant flows in the refrigerant pipe, wherein the ice-making tray includes an ice-making cell that stores ice-making water, and a temperature sensor accommodation portion that accommodates a temperature sensor that measures temperature of water or ice stored in the ice-making cell, and the temperature sensor accommodation portion includes an accommodation portion that is formed in a groove shape and has an open upper side so that the temperature sensor moves in or out, and a fixing portion which is coupled to a wire connected to a part of the temperature sensor or the temperature sensor and fixes a position of the temperature sensor. 
     The temperature sensor accommodation portion may further include a connecting portion that is provided as a path through which the wire connected to the temperature sensor extends toward an outside of the ice-making tray, and the fixing portion may be formed to be bent toward one side of the accommodation portion. 
     An ice-making water contact portion, of which at least a part of a side surface facing the ice-making cell is open, may be formed at the temperature sensor accommodation portion, and the connecting portion may be formed to extend in a direction opposite to the ice-making water contact portion. 
     The ice-making tray may further include a first tray in contact with the refrigerant pipe to receive cooling energy from the refrigerant pipe, and a second tray coupled to overlap a top surface of the first tray to receive cooling energy from the first tray, and formed of a material having thermal conductivity lower than that of the first tray, wherein the ice-making cell is formed in the second tray. 
     The temperature sensor accommodation portion may be formed at a position facing the ice-making cell in the second tray. 
     The refrigerant pipe may include a first refrigerant pipe that extends in a length direction of the ice-making tray, a second refrigerant pipe disposed in parallel to the first refrigerant pipe, and a third refrigerant pipe that connects the first refrigerant pipe and the second refrigerant pipe, and has a U shape, and the ice-making tray may include a protrusion formed on a bottom surface thereof so that the third refrigerant pipe is spaced apart from the ice-making tray. 
     The protrusion may be formed at a region facing the third refrigerant pipe on the bottom surface of the ice-making tray. 
     The refrigerator may further include a drain duct coupled to a lower portion of the ice-making tray to collect defrosted water of the ice-making tray, wherein the drain duct may include a hinge-coupling portion coupled to the ice-making tray to rotate around one side of the ice-making tray and to be open, and a rotation limiting portion that limits a range within which the drain duct rotates. 
     The rotation limiting portion may be formed in a radius of rotation of the drain duct. 
     The rotation limiting portion may be formed at an inner side surface of the ice-making tray. 
     The refrigerator may further include an ejector that separates ice from the ice-making tray, and an ice-ejecting motor portion coupled to one side of the ice-making tray, wherein an ice-ejecting motor that rotates the ejector is installed inside the ice-ejecting motor portion, wherein a locking step that protrudes in a side direction may be formed at one side surface of the ice-ejecting motor portion, and a supporting member provided at a position corresponding to the locking step to support the locking step may be formed at the ice-making tray. 
     The ice-ejecting motor portion may include a screw-coupling portion screw-coupled to the ice-making tray, and the locking step may be formed to be spaced a predetermined gap from the screw-coupling portion to prevent the ice-ejecting motor portion from sagging. 
     The screw-coupling portion and the locking step may be formed at the same plane of the ice-ejecting motor portion, and a distance between the screw-coupling portion and the ice-making cell may be less than a distance between the locking step and the ice-making cell. 
     The ice-ejecting motor portion may further include a seating guide provided so that a part of a coupling surface of the ice-making tray coupled to the screw-coupling portion is seated. 
     The seating guide may include a first seating guide and a second seating guide that respectively support a bottom surface and one side surface of the coupling surface of the ice-making tray coupled to the screw-coupling portion. 
     In accordance with another aspect of the present disclosure, a refrigerator includes a main body, an ice-making chamber formed inside the main body, an ice-making tray installed inside the ice-making chamber, wherein ice-making water is stored and ice is generated in the ice-making tray, and a refrigerant pipe installed so that at least a part thereof is in contact with the ice-making tray, wherein a refrigerant flows in the refrigerant pipe, wherein the refrigerant pipe includes a first refrigerant pipe that extends in a length direction of the ice-making tray, a second refrigerant pipe disposed in parallel to the first refrigerant pipe, and a third refrigerant pipe that connects the first refrigerant pipe and the second refrigerant pipe, and has a U shape, and the ice-making tray includes a protrusion formed on a bottom surface thereof so that the third refrigerant pipe is spaced apart from the ice-making tray. 
     The protrusion may be formed at a region facing the third refrigerant pipe on the bottom surface of the ice-making tray. 
     The ice-making tray may further include a first tray in contact with the refrigerant pipe to receive cooling energy from the refrigerant pipe, and a second tray coupled to overlap a top surface of the first tray to receive cooling energy from the first tray, and formed of a material having thermal conductivity lower than that of the first tray, wherein the ice-making cell is formed in the second tray, and the protrusion may be formed at a region facing the third refrigerant pipe on a bottom surface of the first tray. 
     In accordance with still another aspect of the present disclosure, a refrigerator includes a main body, an ice-making chamber formed inside the main body, an ice-making tray installed inside the ice-making chamber, wherein ice-making water is stored and ice is generated in the ice-making tray, a refrigerant pipe installed so that at least a part thereof is in contact with the ice-making tray, wherein a refrigerant flows in the refrigerant pipe, and a drain duct that is coupled to a lower portion of the ice-making tray to collect defrosted water of the ice-making tray, wherein the drain duct includes a hinge-coupling portion coupled to the ice-making tray to rotate around one side of the ice-making tray and to be open, and a rotation limiting portion that limits a range within which the drain duct rotates. 
     The rotation limiting portion may be formed in a radius of rotation of the drain duct in an inner side surface of the ice-making tray. 
     The ice-making tray may further include a first tray in contact with the refrigerant pipe to receive cooling energy from the refrigerant pipe, and a second tray coupled to overlap a top surface of the first tray to receive cooling energy from the first tray, and formed of a material having thermal conductivity lower than that of the first tray, wherein the ice-making cell is formed in the second tray, and the rotation limiting portion may be formed in a radius of rotation of the drain duct in an inner side surface of the first tray. 
     In accordance with yet another aspect of the present disclosure, a refrigerator includes a main body, an ice-making chamber formed inside the main body, an ice-making tray installed inside the ice-making chamber, wherein ice-making water is stored and ice is generated in the ice-making tray, a refrigerant pipe installed so that at least a part thereof is in contact with the ice-making tray, wherein a refrigerant flows in the refrigerant pipe, an ejector that separates ice from the ice-making tray, and an ice-ejecting motor portion coupled to one side of the ice-making tray, wherein an ice-ejecting motor that rotates the ejector is installed inside the ice-ejecting motor portion, wherein a screw-coupling portion screw-coupled to the ice-making tray and a locking step that is spaced a predetermined gap from the screw-coupling portion and protrudes toward a side thereof are formed at one side surface of the ice-ejecting motor portion, and a supporting member provided at a position corresponding to the locking step to support the locking step is formed at the ice-making tray. 
     The ice-making tray may further include a first tray in contact with the refrigerant pipe to receive cooling energy from the refrigerant pipe, and a second tray coupled to overlap a top surface of the first tray to receive cooling energy from the first tray, and formed of a material having thermal conductivity lower than that of the first tray, where in the ice-making cell is formed in the second tray, and the supporting member may be provided at a position corresponding to the locking step of the ice-ejecting motor portion coupled to the second tray. 
     The ice-ejecting motor portion may further include a seating guide provided so that a part of a coupling surface of the ice-making tray coupled to the screw-coupling portion is seated, and the seating guide may include a first seating guide and a second seating guide that respectively support a bottom surface and one side surface of the coupling surface of the ice-making tray coupled to the screw-coupling portion. 
    
    
     
       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 view illustrating an exterior of a refrigerator according to an embodiment of the present disclosure; 
         FIG. 2  is a schematic cross-sectional view illustrating an internal structure of the refrigerator of  FIG. 1 ; 
         FIG. 3  is a schematic enlarged cross-sectional view illustrating a structure of an ice-making chamber of the refrigerator of  FIG. 1 ; 
         FIG. 4  is a perspective view illustrating an ice maker of the refrigerator of  FIG. 1 ; 
         FIG. 5  is an exploded perspective view illustrating the ice maker of  FIG. 4 ; 
         FIG. 6  is a cross-sectional view illustrating a cross-section of the ice maker of  FIG. 4 ; 
         FIG. 7  and  FIG. 8  are exploded top perspective views illustrating an ice-making tray of the ice maker of  FIG. 4 ; 
         FIG. 9  is an exploded bottom perspective view illustrating the ice-making tray of the ice maker of  FIG. 4 ; 
         FIG. 10  is a view illustrating a top surface of a first tray of the ice maker of  FIG. 4 ; 
         FIG. 11  is a view illustrating a bottom surface of the first tray of the ice maker of  FIG. 4 ; 
         FIG. 12  is a view illustrating a cross-section of a part in which a protrusion formed at the bottom surface of the first tray in the ice maker of  FIG. 4  is installed; 
         FIG. 13  is an enlarged view illustrating a temperature sensor accommodation portion formed at a second tray of the ice maker of  FIG. 4 ; 
         FIG. 14  is an enlarged view illustrating the temperature sensor accommodation portion of the ice maker of  FIG. 4  seen from the side; 
         FIG. 15  is a view illustrating a cross-section of the temperature sensor accommodation portion formed at the second tray of the ice maker of  FIG. 4 ; 
         FIG. 16  is a view for describing a structure of an ice-making chamber for coupling the ice-making tray of  FIG. 4  to the ice-making chamber; 
         FIG. 17  is a cross-sectional view for describing an air insulating portion of the ice-making tray of  FIG. 4 ; 
         FIG. 18  is a view illustrating a state in which a drain duct and the ice-making tray are coupled to each other, seen from one side of the ice maker of  FIG. 4 ; 
         FIG. 19  and  FIG. 20  are views illustrating an operation in which the drain duct of  FIG. 18  rotates and opens at a predetermined angle; 
         FIG. 21  is a view illustrating a coupling relation between an ice-ejecting motor portion and the ice-making tray in the ice maker of  FIG. 4 ; 
         FIG. 22  is a view illustrating a supporting member formed at an inner side surface of the ice-making tray in the ice maker of  FIG. 4 ; and 
         FIG. 23  is a view illustrating a state in which the ice-ejecting motor portion of  FIG. 21  and the ice-making tray are coupled to each other. 
     
    
    
     DETAILED DESCRIPTION 
     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. 
       FIG. 1  is a view illustrating an exterior of a refrigerator according to an embodiment of the present disclosure.  FIG. 2  is a schematic cross-sectional view illustrating an internal structure of the refrigerator of  FIG. 1 .  FIG. 3  is a schematic enlarged cross-sectional view illustrating a structure of an ice-making chamber of the refrigerator of  FIG. 1 . 
     Referring to  FIGS. 1 to 3 , a refrigerator  1  according to an embodiment of the present disclosure may include a main body  2 , a refrigerator compartment  10  and a freezer compartment  11  capable of keeping food refrigerated or frozen, an ice-making chamber  60  formed to be partitioned off from the refrigerator compartment  10  and the freezer compartment  11  by an ice-making chamber wall  61 , and a cooling unit  50  to supply cold air to the refrigerator compartment  10  and the freezer compartment  11  and the ice-making chamber  60 . 
     The main body  2  may include an inner box  3  forming the refrigerator compartment  10  and the freezer compartment  11 , an outer box  4  coupled to cover the inner box  3  thus forming an exterior, and an insulating material  5  foamed between the inner box  3  and the outer box  4 . 
     The refrigerator compartment  10  and the freezer compartment  11  may be formed such that a front side thereof is open, and may be partitioned into the refrigerator compartment  10  at an upper side thereof and a freezer compartment  11  at a lower side thereof by a horizontal partition  6 . The horizontal partition  6  may include an insulating material configured to block heat exchange between the refrigerator compartment  10  and the freezer compartment  11 . 
     Shelves  9  on which food is put and which vertically divide a storage space of the refrigerator compartment  10  may be disposed in the refrigerator compartment  10 . The open front side of the refrigerator compartment  10  may be hinge-coupled to the main body  2 , and be opened and closed by a pair of doors  12  and  13  that are rotatable. Handles  16  and  17  configured to open and close the doors  12  and  13  may be respectively provided at the doors  12  and  13 . 
     A dispenser  20  capable of extracting ice from the ice-making chamber  60  to an outside thereof without opening a door  12  may be provided at the door  12 . The dispenser  20  may include an extraction space  24  through which ice is extracted, a lever  25  by which ice is determined whether to be extracted or not, and a chute  22  which guides the ice discharged through an ice discharging orifice  93  to the extraction space  24 . 
     An open front side of the freezer compartment  11  may be opened and closed by a sliding door  14  capable of sliding in the freezer compartment  11 . A storage box  19  capable of accommodating food may be provided at a rear surface of the sliding door  14 . A handle  18  configured to open and close the sliding door  14  may be provided at the sliding door  14 . 
     The cooling unit  50  may include a compressor  51  that compresses a refrigerant using high pressure, a condenser  52  that condenses the compressed refrigerant, expansion units  54  and  55  that expand the refrigerant to low pressure, evaporators  34  and  44  that evaporate the refrigerant and generate cold air, and a refrigerant pipe  56  that guides the refrigerant. 
     The compressor  51  and the condenser  52  may be disposed in a machine compartment  70  provided at a rear lower side of the main body  2 . In addition, the evaporators  34  and  44  may be respectively disposed at a refrigerator compartment cold air supply duct  30  that is provided at the refrigerator compartment  10 , and a freezer compartment cold air supply duct  40  that is provided at the freezer compartment  11 . 
     The refrigerator compartment cold air supply duct  30  may include an inlet  33 , a cold air discharge orifice  32 , and a blower fan  31 , and may circulate cold air in the refrigerator compartment  10 . In addition, the freezer compartment cold air supply duct  40  may include an inlet  43 , a cold air discharge orifice  42 , and a blower fan  41 , and may circulate cold air in the freezer compartment  11 . 
     The refrigerant pipe  56  may be divided at one dividing position so that a refrigerant flows to the freezer compartment  11  or the refrigerant flows to the refrigerator compartment  10  and the ice-making chamber  60 , and a switching valve  53  that switches a flow path of the refrigerant may be installed at the dividing position. 
     A part of the refrigerant pipe  56  may be disposed inside the ice-making chamber  60  to cool the ice-making chamber  60 . The part disposed inside of the ice-making chamber  60  may be in contact with an ice-making tray  281 , and may directly supply cooling energy to the ice-making tray  281  by thermal conduction. 
     Hereinafter, the part of the refrigerant pipe  56  disposed inside the ice-making chamber  60  to be in contact with the ice-making tray  281  is referred as an ice-making chamber refrigerant pipe  57 . A refrigerant in a liquid state may pass through the expansion unit  55  to become a low temperature and low pressure state, flow inside the ice-making chamber refrigerant pipe  57  to absorb heat inside the ice-making tray  281  and the ice-making chamber  60 , and evaporate in a gas state. Accordingly, the ice-making chamber refrigerant pipe  57  and the ice-making tray  281  may perform a function of an evaporator in the ice-making chamber  60 . 
     An ice maker  80  according to one embodiment of the present disclosure includes the ice-making tray  281  that stores ice-making water, an ejector  84  that separates ice from the ice-making tray  281 , an ice-ejecting motor  82  that rotates the ejector  84 , an ice-ejecting heater  87  that heats the ice-making tray  281  to eject ice easily when the ice is separated from the ice-making tray  281 , an ice bucket  90  that stores ice generated by the ice-making tray  281 , a drain duct  500  that collects defrosted water of the ice-making tray  281  and simultaneously guides an air flow inside the ice-making chamber  60 , and an ice-making chamber fan  97  that circulates air inside the ice-making chamber  60 . 
     The ice bucket  90  is disposed under the ice-making tray  281  to collect ice that falls from the ice-making tray  281 . The ice bucket  90  is provided with an auger  91  that transfers stored ice to the ice discharge orifice  93 , an auger motor  95  that drives the auger  91 , and a grinding unit  94  capable of grinding ice. 
     The auger motor  95  may be disposed at a rear of the ice-making chamber  60 , and the ice-making chamber fan  97  may be disposed above the auger motor  95 . A guiding path  96  which guides air discharged from the ice-making chamber fan  97  toward a front side of the ice-making chamber  60  may be provided above the ice-making chamber fan  97 . 
     Air that forcibly flows by the ice-making chamber fan  97  may circulate inside the ice-making chamber  60  in an arrow direction denoted in  FIG. 3 . That is, the air discharged upward from the ice-making chamber fan  97  may flow through the guiding path  96  and may flow between the ice-making tray  281  and the drain duct  500 . At this time, the air may exchange heat with the ice-making tray  281  and the ice-making chamber refrigerant pipe  57 , and the cooled air may flow to a side of the ice discharge orifice  93  of the ice bucket  90  and may be suctioned by the ice-making chamber fan  97 . 
     A lower portion of the ice-making tray  281  according to an embodiment of the present disclosure may include a first tray  300  (see  FIG. 2 ) formed of an aluminum material, which will be described below. Since a heat exchanging rib  380  (see  FIG. 6 ), which expands an area which transfers heat to air inside the ice-making chamber  60 , is provided at the first tray  300 , the efficiency of exchanging heat of internal air between the ice-making tray  281  and the ice-making chamber  60  is increased, and accordingly, an inside of the ice-making chamber  60  may be efficiently maintained to be cooled and chilled. 
       FIG. 4  is a perspective view illustrating an ice maker of the refrigerator of  FIG. 1 ,  FIG. 5  is an exploded perspective view illustrating the ice maker of  FIG. 4 ,  FIG. 6  is a cross-sectional view illustrating a cross-section of the ice maker of  FIG. 4 ,  FIGS. 7 and 8  are exploded top perspective views illustrating an ice-making tray of the ice maker of  FIG. 4 ,  FIG. 9  is an exploded bottom perspective view illustrating the ice-making tray of the ice maker of  FIG. 4 ,  FIG. 10  is a view illustrating a top surface of a first tray of the ice maker of  FIG. 4 , and  FIG. 11  is a view illustrating a bottom surface of the first tray of the ice maker of  FIG. 4 . 
     Referring to  FIGS. 1 to 11 , the ice-making tray  281  includes the first tray  300  that is in contact with the ice-making chamber refrigerant pipe  57 , receives cooling energy from the ice-making chamber refrigerant pipe  57  by thermal conduction, and is positioned at a lower portion thereof, and a second tray  400  that is coupled to overlap a top surface of the first tray  300  to receive the cooling energy from the first tray  300 , and includes an ice-making cell  410  that stores ice-making water. 
     Since the first tray  300  is provided under the second tray  400 , the first tray  300  may be referred as a lower tray, and the second tray  400  may be referred as an upper tray. 
     In the above-described structure, cooling energy is sequentially transferred from the ice-making chamber refrigerant pipe  57  through the first tray  300  to the second tray  400 , ice-making water stored in the ice-making cell  410  of the second tray  400  may be cooled, and ice may be generated. 
     The first tray  300  may include ice-making cell accommodation portions  310  concavely formed to accommodate the ice-making cell  410  of the second tray  400 , and a first base portion  320  forming the ice-making cell accommodation portion  310 . 
     The ice-making cell accommodation portion  310  of the first tray  300  may have a shape corresponding to the ice-making cell  410  to accommodate the ice-making cell  410  of the second tray  400 . The number of ice-making cell accommodation portions  310  may be equal to that of the ice-making cells  410 . The ice-making cell accommodation portions  310  may be partitioned from each other by first partition portions  330 . First communication portions  331  that enable ice-making cells  410  to communicate with each other may be provided at the first partition portions  330 . Ice-making water may be sequentially supplied to the ice-making cells  410  through the first communication portions  331 . 
     A heat exchanging rib  380  which expands an area which transfers heat to air inside the ice-making chamber  60 , and facilitates heat exchange of internal air between the first tray  300  and the ice-making chamber  60  may protrude. 
     A refrigerant pipe accommodation portion  390  which accommodates the ice-making chamber refrigerant pipe  57 , and an ice-ejecting heater accommodation portion  391  which accommodates the ice-ejecting heater  87  may be formed at an outside of a lower portion of the first tray  300 . Each of the refrigerant pipe accommodation portion  390  and the ice-ejecting heater accommodation portion  391  may have a concave shape. The refrigerant pipe accommodation portion  390  and the ice-ejecting heater accommodation portion  391  may be formed between the heat exchanging ribs  380 . 
     Each of the ice-making chamber refrigerant pipe  57  and the ice-ejecting heater  87  may be provided in a roughly U shape, and the refrigerant pipe accommodation portion  390  and the ice-ejecting heater accommodation portion  391  of the first tray  300  may also have a roughly U shape to correspond thereto. The refrigerant pipe accommodation portion  390  may be provided inside the ice-ejecting heater accommodation portion  391 . As illustrated in  FIG. 9 , the ice-making chamber refrigerant pipe  57  may include a first refrigerant pipe portion  57   a  that extends in a length direction of the ice-making tray  281 , a second refrigerant pipe portion  57   b  disposed in parallel to the first refrigerant pipe portion  57   a , and a third refrigerant pipe portion  57   c  that connects the first refrigerant pipe portion  57   a  and the second refrigerant pipe portion  57   b , and has a U shape. 
     The ice-making chamber refrigerant pipe  57  may be accommodated in the refrigerant pipe accommodation portion  390  to be in contact with the first tray  300 , and the ice-ejecting heater  87  may be accommodated in the ice-ejecting heater accommodation portion  391  to be in contact with the first tray  300 . 
     The first tray  300  may be formed of a material having high thermal conductivity to accelerate thermal conduction of cooling energy. For example, the first tray  300  may be formed of an aluminum material. The first tray  300  may be integrally formed. 
     A drain orifice  392  that drains defrosted water of frost frosted between the first tray  300  and the second tray  400  may be formed at the first tray  300 . The drain orifice  392  may be formed at each of the ice-making cell accommodation portions  310  of the first tray  300 . 
     The drain orifice  392  may decrease a heat transfer area of the first tray  300  and the second tray  400 , and may serve a function that decreases an ice-making speed. 
       FIG. 12  is a view illustrating a cross-section of a part in which a protrusion formed at the bottom surface of the first tray in the ice maker of  FIG. 4  is installed. 
     Referring to  FIGS. 2 to 12 , according to one embodiment, the first tray  300  may further include a protrusion  340  which separates a bottom surface of the first tray  300  and the ice-making chamber refrigerant pipe  57 . The protrusion  340  may be formed at the bottom surface of the first tray  300 , and may decrease a contact area between the ice-making chamber refrigerant pipe  57  and the first tray  300 . 
     The protrusion  340  may be formed at a bottom surface of the ice-making tray  281  so that the third refrigerant pipe portion  57   c  is separated from the ice-making tray  281 . The protrusion  340  may be formed at a region of the bottom surface of the first tray  300  which faces the third refrigerant pipe portion  57   c . The protrusion  340  may be installed at the refrigerant pipe accommodation portion  390  in a plural number at predetermined gaps. 
     Since a contact area between the third refrigerant pipe portion  57   c  and the bottom surface of the first tray  300  is greater than a contact area between the first refrigerant pipe portion  57   a  and the second refrigerant pipe portion  57   b , the ice-making chamber refrigerant pipe  57  may be excessively cooled. Accordingly, in the above-described structure, the contact area between the third refrigerant pipe portion  57   c  and the bottom surface of the first tray  300  may decrease, and cooling energy received from the ice-making chamber refrigerant pipe  57  may be uniformly controlled in the first tray  300 . 
     The first tray  300  may be formed of a material having high thermal conductivity to accelerate thermal conduction of cooling energy. For example, the first tray  300  may be formed of an aluminum material. The first tray  300  may be integrally formed. 
     The second tray  400  may be coupled to be in close contact with the top surface of the first tray  300 . As the second tray  400  is simply put on the top surface of the first tray  300 , the second tray  400  may be coupled to the first tray  300 . 
     However, a first coupling portion  370  may be provided at the first tray  300  and a second coupling portion  480  may be provided at the second tray  400  to increase a coupling force between the first tray  300  and the second tray  400 . 
     The first coupling portion  370  and the second coupling portion  480  may be respectively provided at a side surface of the first tray  300  and a side surface of the second tray  400 . The first coupling portion  370  and the second coupling portion  480  may be elastically coupled to each other. The first coupling portion  370  may include a coupling protrusion  371  (see  FIG. 15 ) and the second coupling portion  480  may include a coupling groove  481  (see  FIG. 15 ) coupled to the coupling protrusion  371 . 
     The second tray  400  may include an ice-making cell  410  that stores ice-making water, a second base portion  420  forming the ice-making cell  410 , second partition portions  430  that partition the ice-making cells  410  from each other, and second communication portions  431  that enable the ice-making cells  410  to communicate with each other to supply water to all of the ice-making cells  410  when the water is supplied. 
     When the ice-making speed of ice-making water is excessively high, a gas such as oxygen or carbon dioxide and other impurities melted in the ice-making water are not discharged, and a turbidity phenomenon in which ice is turbid may occur. 
     In order to solve the above-described turbidity phenomenon, the second tray  400  of the ice-making tray  281  according to an embodiment of the present disclosure is formed of a material having low thermal conductivity. For example, the second tray  400  may be formed of a plastic material. As a result, as the speed of thermal conduction of cooling energy decreases, the cooling speed of ice-making water may decrease, and accordingly, transparency of ice may be improved. 
     However, materials of the first tray  300  and the second tray  400  are not respectively limited to an aluminum material and a plastic material, and as long as the second tray  400  is formed of a material that has a lower thermal conductivity than that of the first tray  300 , it may be consistent with the scope of the present disclosure. 
     That is, materials of the first tray  300  and the second tray  400  may be properly selected as long as the first tray  300  positioned thereunder is formed with a comparatively high thermal conductivity and effectively serves as a heat exchanger that cools the ice-making chamber  60 , the second tray  400  positioned thereabove decreases a speed of thermal conduction of cooling energy slightly, and thus ice whose transparency is improved is generated. 
     The second tray  400  may be integrally formed. Accordingly, since each of the first tray  300  and the second tray  400  are formed, and the second tray  400  is simply coupled to overlap the top surface of the first tray  300 , the ice-making tray  281  may be easily assembled, and thus all objectives of maintaining cooling performance inside the ice-making chamber  60  and improving transparency of ice may be achieved. 
     In the above description, as the second tray  400  is formed of a material having a lower thermal conductivity than that of the first tray  300 , a speed of thermal conduction of cooling energy and a speed of cooling ice-making water may be decreased; however, alternatively or additionally, as a heat transfer area of the ice-making chamber refrigerant pipe  57  and the first tray  300  is decreased, a speed of thermal conduction of cooling energy and a speed of cooling ice-making water may be decreased. 
     To this end, even though it is not illustrated, a heat-transfer-area-reducing orifice (not shown) that reduces a heat transfer area of the ice-making chamber refrigerant pipe  57  may be formed at a portion in contact with the ice-making chamber refrigerant pipe  57  of the first tray  300 . That is, a heat-transfer-area-reducing orifice  170  may be formed at the refrigerant pipe accommodation portion  390  of the first tray  300 . 
     With the above-described structure, the ice-making tray  281  may receive cooling energy from the ice-making chamber refrigerant pipe  57  by the direct cooling method, and may quickly generate ice, and ice having improved transparency may be obtained. In addition, the same cooling performance of the ice-making chamber  60  of the ice-making tray  281  as that of a conventional ice-making tray may be maintained. 
     The second tray  400  may be coupled to be in close contact with the top surface of the first tray  300 . The second tray  400  may be simply put on the top surface of the first tray  300 , and coupled to the first tray  300 . 
     However, the first coupling portion  370  may be provided at the first tray  300  and the second coupling portion  480  may be provided at the second tray  400  to increase a coupling force between the first tray  300  and the second tray  400 . 
     The first coupling portion  370  and the second coupling portion  480  may be respectively provided at a side surface of the first tray  300  and a side surface of the second tray  400 . The first coupling portion  370  and the second coupling portion  480  may be elastically coupled to each other. The first coupling portion  370  may include the coupling protrusion  371  and the second coupling portion  480  may include the coupling groove  481  coupled to the coupling protrusion  371 . 
     The second tray  400  may include an ice-making cell  410  that stores ice-making water, the second base portion  420  forming the ice-making cell  410 , second partition portions  430  that partition the ice-making cells  410  from each other, and second communication portions  431  that enable the ice-making cells  410  to communicate with each other to supply water to all of the ice-making cells  410  when the water is supplied. 
     The second tray  400  may include a separation preventing wall  440  that extends upward from one end of a widthwise side of the second base portion  420  to guide movement of ice when the ice is separated from the ice-making cell  410 . When the ejector  84  rotates and lifts ice of the ice-making cell  410 , the separation preventing wall  440  may prevent the ice from falling to the other side opposite to one side in which a slider  88  is provided. A slit  441  which prevents heat from vertically transferring through the separation preventing wall  440  may be formed at the separation preventing wall  440 . The slit  441  may be formed long in a horizontal direction at the separation preventing wall  440 . 
     The second tray  400  may include cutting ribs  432  that cut links between ice pieces generated at the ice-making cells  410  when the ice pieces are separated from the ice-making cell  410 . 
     The second tray  400  may include a water supplying orifice  460  provided at a lengthwise end thereof to supply water to the ice-making cell  410 . As the second tray  400  is provided to be inclined, water introduced from the water supplying orifice  460  may be sequentially supplied from the ice-making cell  410  most adjacent to the water supplying orifice  460  to the ice-making cell  410  farthest therefrom. 
     The second tray  400  may include an excessively supplied water discharge orifice  450  that discharges excessively supplied water through the drain duct  500  when the ice-making cell  410  is supplied with water more than a predetermined amount of water. The excessively supplied water discharge orifice  450  may be formed at one position of the separation preventing wall  440 . 
     The second tray  400  may include a structure which supports the ejector  84 , which separates ice generated at the ice-making cell  410 . The second tray  400  may include rotating shaft accommodation portions  401  and  402  that rotatably accommodate a rotating shaft  85  of the ejector  84 . The rotating shaft accommodation portions  401  and  402  may be respectively formed at a front end and a rear end of the second tray  400  in a lengthwise direction. 
       FIG. 13  is an enlarged view illustrating a temperature sensor accommodation portion formed at a second tray of the ice maker of  FIG. 4 ,  FIG. 14  is an enlarged view illustrating the temperature sensor accommodation portion of the ice maker of  FIG. 4  seen from the side, and  FIG. 15  is a view illustrating a cross-section of the temperature sensor accommodation portion formed at the second tray of the ice maker of  FIG. 4 . 
     Referring to  FIGS. 2 to 15 , the second tray  400  may include a temperature sensor accommodation portion  403  which accommodates a temperature sensor  600  which measures temperature of water or ice accommodated in the ice-making cell  410 . The temperature sensor accommodation portion  403  may be formed at one lengthwise end of the second tray  400 , and accordingly, the temperature sensor  600  may measure temperature of water or ice accommodated in the ice-making cell  410  most adjacent to the lengthwise end of the second tray  400 . 
     According to one embodiment, the temperature sensor accommodation portion  403  may include an accommodation portion  403   a  and a fixing portion  403   d . The accommodation portion  403   a  may be formed in a groove shape of which an upper side is open through which the temperature sensor  600  moves in or out. The temperature sensor  600  may move through the upper side of the accommodation portion  403   a  to a lower portion thereof, and may be installed at the second tray  400 . 
     The temperature sensor accommodation portion  403  may further include an ice-making water contact portion  403   c . The ice-making water contact portion  403   c  may be formed at one side of the accommodation portion  403   a . The ice-making water contact portion  403   c  may be provided in a shape in which at least a part of a side thereof facing the ice-making cell  410  is opened. The temperature sensor  600  accommodated in the temperature sensor accommodation portion  403  may be in contact with ice-making water through the ice-making water contact portion  403   c , and may measure a temperature thereof. Optionally, the ice-making water contact portion  403   c  may also be omitted. 
     The temperature sensor accommodation portion  403  may further include a connecting portion  403   b . The connecting portion  403   b  may be formed at one side of the accommodation portion  403   a . The connecting portion  403   b  may be formed to extend from one side of the accommodation portion  403   a  in a direction different from the ice-making water contact portion  403   c . The connecting portion  403   b  may be formed to extend in a direction opposite to the ice-making water contact portion  403   c . The connecting portion  403   b  may be provided as a path through which a wire (not shown) connected to the temperature sensor  600  extends toward an outside of the ice-making tray  281 . The connecting portion  403   b  may be provided as a path through which a wire (not shown) connected to the temperature sensor  600  extends toward an outside of the second tray  400 . 
     The fixing portion  403   d  may be provided to be coupled to a part of the temperature sensor  600  or the wire (not shown) connected to the temperature sensor  600 , and may fix a position of the temperature sensor  600 . The fixing portion  403   d  may be formed to be bent toward one side of the accommodation portion  403   a . The fixing portion  403   d  may be provided so that the wire (not shown) connected to the temperature sensor  600  is fixed at a space which is formed to be bent toward one side of the accommodation portion  403   a.    
     The fixing portion  403   d  may be formed to extend from the accommodation portion  403   a  along the connecting portion  403   b . Accordingly, the wire (not shown) connected to the temperature sensor  600  may extend along the connecting portion  403   b  toward the outside of the second tray  400  while coupled to the fixing portion  403   d.    
     According to the above-described structure, in a state in which the temperature sensor  600  is accommodated in the temperature sensor accommodation portion  403 , the wire (not shown) connected to the temperature sensor  600  may be coupled to the fixing portion  403   d , and the temperature sensor  600  may be fixed. 
     The position of the temperature sensor  600  may be vertically changed according to the accommodation portion  403   a  while ice-making water is introduced to the ice-making cell  410  or is discharged therefrom. In addition, the position of the temperature sensor  600  may be vertically changed with ice-making water according to the accommodation portion  403   a  while ice-making water is being frozen. In this case, since the temperature sensor  600  may not measure temperature at the same position, a correct temperature may not be measured. In addition, when the measured temperature is not correct, a reliability of a freezing system may be lowered such as excessive freezing and the like. According to the above-described structure, temperature of ice-making water may be measured under the same condition, and thus reliability of a freezing system of the refrigerator may be improved. 
       FIG. 16  is a view for describing a structure of an ice-making chamber for coupling the ice-making tray of  FIG. 4  to the ice-making chamber, and  FIG. 17  is a cross-sectional view for describing an air insulating portion of the ice-making tray of  FIG. 4 . 
     Referring to  FIGS. 2 to 17 , the second tray  400  may include an air insulating portion  490  which insulates the ice-making tray  281  from an ice-ejecting motor  82 . Since the air insulating portion  490  insulates the ice-making tray  281  from the ice-ejecting motor  82 , malfunction of the ice-ejecting motor  82  and unnecessary heat loss may be prevented. 
     The air insulating portion  490  may include an air wall portion  492  that protrudes from a lengthwise front end of the second tray  400 , and an air accommodation portion  491  formed inside the air wall portion  492 . A side of the air wall portion  492  may be formed in a closed loop shape, and a front side of the air wall portion  492  may be open. The open front side of the air wall portion  492  may be closed by an ice-ejecting motor case  542  which accommodates the ice-ejecting motor  82 . Accordingly, an inside of the air accommodation portion  491  may be a closed space. As the air accommodation portion  491  is filled with air, the air accommodation portion  491  may insulate the ice-making tray  281  from the ice-ejecting motor  82 . 
     The ice-ejecting motor case  542  may be formed by coupling a front case  544  and a rear case  543 , and the air wall portion  492  may be provided to be in close contact with the rear case  543 . An ice-ejecting motor portion  540  may include the ice-ejecting motor  82  and the ice-ejecting motor case  542 . 
     The second tray  400  may include a fixing portion which fixes the ice-making tray  281  inside the ice-making chamber  60 . That is, the ice-making tray  281  may be directly fixed inside the ice-making chamber  60  without an additional fixing member. 
     The fixing portion may couple the second tray  400  to a ceiling of the inner box  3  of the ice-making chamber  60 . To this end, the fixing portion may include a groove portion  471  coupled to a hook portion  3   a  provided at the ceiling of the inner box  3  of the ice-making chamber  60 . 
     The groove portion  471  may include a large diameter portion  472  that is comparatively large, and a small diameter portion  473  that is comparatively small. The large diameter portion  472  may have a size through which the hook portion  3   a  may enter, and the small diameter portion  473  may have a size through which the hook portion  3   a , which passed through the large diameter portion  472 , may not move out. 
     When the ice-making tray  281  is inserted into the ice-making chamber  60 , the hook portion  3   a  may be inserted into the large diameter portion  472  of the second tray  400 , and may move toward the small diameter portion  473 . Since the hook portion  3   a  that moves toward the small diameter portion  473  is not separated from the small diameter portion  473 , the ice-making tray  281  may be fixed to the ice-making chamber  60 . 
     The fixing portion may include a mounting portion  474  in which the second tray  400  is put on a supporting portion  98  provided at the ice-making chamber  60  and is supported thereby. The supporting portion  98  may also be integrally formed with the inner box  3  of the ice-making chamber  60 , and may also be formed in a separate structure provided inside the ice-making chamber  60 . 
     The above-described fixing portion may be formed at a front outside or a rear outside of an upper portion of the ice-making cell  410  of the second tray  400 . That is, the upper portion of the ice-making cell  410  of the second tray  400  may be open. The reason is that injection molding of the second tray  400  in which the fixing portion is integrally formed is performed easily. When the fixing portion is not positioned at the outside of the upper portion of the ice-making cell  410  of the second tray  400  but is positioned at a direct upper portion thereof, it may not be easy to inject the second tray  400  using a general mold. 
     In the above-described structure, according to an embodiment of the present disclosure, an ice-making speed of the ice-making tray  281  is decreased and transparency of ice is improved. In addition, components of related parts of the ice-making tray  281  are integrally formed with the ice-making tray  281 , the number of components is decreased, and thus performance of assembly and productivity may be improved. 
     The drain duct  500  may be provided under the ice-making tray  281  and collect defrosted water fallen from the ice-making tray  281  or the ice-making chamber refrigerant pipe  57 . A path for cold air may be formed between the ice-making tray  281  and the drain duct  500 . 
     The drain duct  500  may include a drain plate  510  that collects defrosted water, and a frost preventing cover  520  that surrounds a lower portion of the drain plate  510  to prevent freezing of the drain plate  510 . 
     The drain plate  510  may be disposed to be inclined so that collected water flows toward a drain orifice. 
     The drain plate  510  may include a refrigerant pipe fixing portion  515  that presses the ice-making chamber refrigerant pipe  57  and presses and fixes the ice-making chamber refrigerant pipe  57  against and to the bottom surface of the first tray  300 . The refrigerant pipe fixing portion  515  may include a protrusion  515   a  that protrudes upward from the drain plate  510 , and an elastic portion  515   b  provided at an end portion of the protrusion  515   a . The elastic portion  515   b  may be formed of a rubber material. Since the elastic portion  515   b  has an elastic force, the elastic portion  515   b  smoothly presses the ice-making chamber refrigerant pipe  57 , and accordingly, prevents damage of the ice-making chamber refrigerant pipe  57  from impact. In addition, the elastic portion  515   b  may prevent cold air from being directly transferred from the ice-making chamber refrigerant pipe  57  to the drain plate  510 , and may prevent frost from occurring at the drain plate  510 . 
     The drain plate  510  may include an ice-ejecting heater contact portion  516  that is in contact with the ice-ejecting heater  87 , fixes the ice-ejecting heater  87 , and receives heat from the ice-ejecting heater  87 . Since heat of the ice-ejecting heater  87  is transferred through the ice-ejecting heater contact portion  516  to the drain plate  510 , frost is prevented from occurring at the drain plate  510 , and, even when frost occurs, the frost may be easily defrosted. 
     According to one embodiment, the drain plate  510  may include a first drain plate  511  and an insulating plate  512 . The first drain plate  511  may be disposed above the insulating plate  512 , and may be provided to collect defrosted water that falls from the ice-making tray  281  or the ice-making chamber refrigerant pipe  57 . 
     The insulating plate  512  may be coupled to the first drain plate  511  to form an insulating space  513 . The insulating plate  512  may be formed of a material having thermal conductivity lower than that of the first drain plate  511 . 
     The frost preventing cover  520  may be formed of a plastic material having a low thermal conductivity. 
     An air insulating layer  530  that insulates the drain plate  510  from the frost preventing cover  520  may be formed between the drain plate  510  and the frost preventing cover  520 . That is, the drain plate  510  and the frost preventing cover  520  are provided to be spaced a predetermined gap from each other, and air may be filled therebetween. 
       FIG. 18  is a view illustrating a state in which a drain duct and the ice-making tray are coupled to each other, seen from one side of the ice maker of  FIG. 4 , and  FIGS. 19 and 20  are views illustrating an operation in which the drain duct of  FIG. 18  rotates and opens at a predetermined angle. 
     Referring to  FIGS. 18 to 20 , the drain duct  500  may be coupled to the ice-making tray  281  to be opened while rotating around one side of the ice-making tray  281 . A hinge-coupling portion  550  that is coupled to rotate around one side of the first tray  300  may be formed at the drain duct  500 . A coupling portion  551  of the drain duct  500  and a coupling portion  379  of the first tray  300  may be hinge-coupled in the hinge-coupling portion  550 . 
     According to one embodiment, the first tray  300  may further include a rotation limiting portion  360  that limits a range in which the drain duct  500  rotates. The rotation limiting portion  360  may be formed in a radius of rotation of the drain duct  500 . Accordingly, the rotation limiting portion  360  may be provided so that the drain duct  500  rotates only in a predetermined range. 
     An inclined surface  361  may be formed at a bottom surface of the rotation limiting portion  360  to be in contact with a contact surface of the drain duct  500 . Accordingly, destruction of the drain duct  500 , which may occur when the coupling portion  551  of the drain duct  500  rotates and is in contact with the rotation limiting portion  360 , may be prevented. The rotation limiting portion  360  may also be provided of an elastic material. The rotation limiting portion  360  may be formed at an inner side surface of the first tray  300 . The rotation limiting portion  360  may be formed at an inner side surface of the coupling portion  379  to which the first tray  300  is hinge-coupled. 
     Since the ice-making chamber refrigerant pipe  57 , the ice-ejecting heater  87 , and the like are disposed between the drain duct  500  and the ice-making tray  281 , the drain duct  500  is constituted to be openable. Accordingly, as described above, when the drain duct  500  is opened, since an angle thereof is limited, it does not need to control rotation of the drain duct  500 , and thus user&#39;s convenience may be improved. 
       FIG. 21  is a view illustrating a coupling relation between an ice-ejecting motor portion and the ice-making tray in the ice maker of  FIG. 4 ,  FIG. 22  is a view illustrating a supporting member formed at an inner side surface of the ice-making tray in the ice maker of  FIG. 4 , and  FIG. 23  is a view illustrating a state in which the ice-ejecting motor portion of  FIG. 21  and the ice-making tray are coupled to each other. 
     Referring to  FIGS. 21 to 23 , the ice-ejecting motor portion  540  inside which the ice-ejecting motor  82  is installed may be coupled to the ice-making tray  281 . The ice-ejecting motor portion  540  may be coupled to one side of the second tray  400 . The ice-ejecting motor portion  540  may include a screw-coupling portion  548  which is screw-coupled to one side of the second tray  400 . 
     According to one embodiment, a locking step  545  that protrudes toward a side thereof may be formed at one side surface of the ice-ejecting motor portion  540 . The locking step  545  may be formed to be spaced a predetermined gap from the screw-coupling portion  548 . The locking step  545  and the screw-coupling portion  548  may be formed at the same plane, the locking step  545  may be disposed at one end thereof, and the screw-coupling portion  548  may be disposed at a position facing the locking step  545 . A distance between the screw-coupling portion  548  and the ice-making cell  410  may be less than a distance between the locking step  545  and the ice-making cell  410 . Alternatively, the distance between the screw-coupling portion  548  and the ice-making cell  410  may also be greater than the distance between the locking step  545  and the ice-making cell  410 . 
     A supporting member  475  provided at a position corresponding to the locking step  545  to support the locking step  545  may be formed at the ice-making tray  281 . The supporting member  475  may be formed at the position corresponding to the locking step  545  inside the second tray  400 . In a state in which the ice-ejecting motor portion  540  is coupled to the ice-making tray  281 , the supporting member  475  may be provided to support the locking step  545 . 
     According to the above-described structure, the ice-ejecting motor portion  540  may be coupled so that a sagging phenomenon from the ice-making tray  281  does not occur. 
     In addition, the ice-ejecting motor portion  540  may include a seating guide  547 . The seating guide  547  may be formed to support a part of a coupling surface  477  of the ice-making tray corresponding to the screw-coupling portion  548  of the ice-making tray  281 . The seating guide  547  may include a first seating guide  547   a  that supports a bottom surface of the coupling surface  477  of the ice-making tray, and a second seating guide  547   b  that supports one side surface of the coupling surface  477  of the ice-making tray. In a state in which the ice-ejecting motor portion  540  is coupled to the ice-making tray  281 , the seating guide  547  may be constituted to support the coupling surface  477  of the ice-making tray. 
     According to the above-described structure, the ice-ejecting motor portion  540  may be more stably coupled to the ice-making tray  281 . In addition, since the ice-ejecting motor portion  540  is coupled to the ice-making tray  281  along the seating guide  547 , a coupling convenience thereof may be improved. 
     As is apparent from the above description, a direct cooling ice-making tray according to an embodiment of the present disclosure can generate ice having improved transparency by decreasing a cooling speed of ice-making water slightly compared to a conventional direct cooling ice-making tray formed of only an aluminum material. In addition, the direct cooling ice-making tray according to an embodiment of the present disclosure can still have a cooling speed faster than that of an indirect cooling method. 
     An ice-making tray according to an embodiment of the present disclosure can be easily assembled using a method in which each of an aluminum tray and a plastic tray is integrally formed, and the plastic tray is simply disposed to overlap a top surface of the aluminum tray. 
     Since an aluminum tray having excellent thermal conductivity is disposed at a lower portion of a direct cooling ice-making tray according to an embodiment of the present disclosure, and a heat exchanging rib that expands an area that transfers heat to air inside an ice-making chamber is formed at the aluminum tray, the performance for cooling an inside of the ice-making chamber can be maintained the same as that of a conventional ice-making tray. 
     According to an embodiment of the present disclosure, since related parts of an ice-making tray are integrally unified to the ice-making tray, and the number of the parts is decreased, assembly performance and productivity can be improved. 
     According to an embodiment of the present disclosure, since a position of a temperature sensor coupled to an ice-making tray is fixed, the reliability of the temperature sensor can be improved. 
     According to an embodiment of the present disclosure, since a rotation range of a drain duct is limited to a predetermined range, parts such as a refrigerant pipe installed inside the drain duct can be easily assembled or disassembled. 
     According to an embodiment of the present disclosure, cooling energy can be uniformly transferred to an ice-making tray regardless of a shape of a refrigerant pipe. 
     According to an embodiment of the present disclosure, since an ice-ejecting motor portion and an ice-making tray are stably coupled to each other, sagging of the ice-ejecting motor portion can be prevented. 
     While the present disclosure has been described above in detail with reference to specific shapes, the present disclosure may be understood by those skilled in the art that the embodiment may be variously changed or modified without departing from the scope of the present disclosure.