Patent Publication Number: US-2023148832-A1

Title: Dishwasher

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a continuation application, under 35 U.S.C. §  111  (a), of international application No. PCT/KR2021/006611, filed on May 27, 2021, which claims priority to Korean Patent Application No. 10-2020-0082755, filed Jul. 6, 2020, in the Korean Intellectual Property Office, the disclosures of which are incorporated by reference herein in their entirety. 
    
    
     BACKGROUND 
     Field 
     The disclosure relates to a dishwasher having an improved structure to improve usability of installation space and washing power. 
     Description of Related Art 
     A dishwasher is a device for washing dishes by spraying water onto the dishes. 
     As a configuration of a general dishwasher, the dishwasher includes a machine room including a sump, a washing pump, and the like inside a main body thereof, a washing tub, a basket installed inside the washing tub to accommodate dishes, and a spray nozzle for spraying water, etc. The water sprayed from the spray nozzle by the washing pump is capable of washing the dishes. 
     In order to supply and discharge water, it is essential to install a water supply structure for receiving water supplied from the outside and a drainage structure in the dishwasher. In addition, in order to increase washing efficiency and spray high-pressure water, a machine room having a high-performance pump and sump structure is required. 
     Based on the installation method, conventional dishwashers may be classified into: a built-in dishwasher that is installed in an empty space provided by detaching a part of a furniture cabinet, which is an external support; a free-standing dishwasher that may be placed independently; a counter-top dishwasher that is placed on an upper counter of a furniture cabinet or the like; and an in-sink dishwasher that is manufactured and installed integrally with a sink. 
     The built-in dishwasher has a lot of restrictions in installation space because it is bulky and requires a separate space provided by removing a part of a furniture cabinet, and the free-standing dishwasher has limitations for home use because it occupies a large space in a kitchen due to its large volume. In addition, the counter-top dishwasher and the in-sink dishwasher, which have a relatively small volume, have a limitation in securing a volume of a machine room, resulting in weak washing power, and also have such a small internal space that the number of accommodatable dishes is limited. 
     Therefore, there has been a demand for a dishwasher capable of securing washing power by increasing a volume of a machine room while increasing usability of space. 
     SUMMARY 
     According to an embodiment of the disclosure, a dishwasher includes: a first body; and a second body including a rack configured to hold an object to be washed, a spray nozzle configured to spray water onto the object, and a washing channel connectable to the spray nozzle, the second body being coupleable to or decoupleable from an upper surface of the first body. The first body includes a washing pump configured to supply water, a supply channel configured to supply the water to the washing channel of the second body, a drain port configured to receive the water from the second body, and an upper housing coupleable to an opening formed in an upper surface of an external support so that while the upper housing is coupled to the opening the first body is positionable at a lower end of the upper surface of the external support. 
     The drain port may be in a predetermined area of the first body, and the second body may include a drain housing having an opening at a position opposite to a position of the drain port. 
     The first body may further include a valve at an upper portion of the drain port to selectively open or close an upper portion of the first body, and when the second body is coupled to the first body, the valve may move downward so that a flow path is formed between the drain housing and the drain port. 
     The first body may include a fixing plate positioned above a center of the drain port, with an upper surface of the fixing plate having an area smaller than a cross-sectional area of the drain port, the valve may have a shape to surround the fixing plate, and while the second body is decoupled from the first body, the valve may be positioned on a side surface of the fixing plate by moving upward. 
     The second body may further include a fixing groove formed in a central portion of the drain housing, and the fixing groove may have a bent shape corresponding to a shape of the fixing plate to fix the second body in contact with the fixing plate when the second body is coupled to the first body. 
     The first body may include a coupling housing at the upper portion of the first body, and having a shape to support the second body while the second body is coupled to the first body and surround the valve while the second body is decoupled from the first body. 
     When the second body is decoupled from the first body, the fixing plate, the valve, and the coupling housing may be positioned on the same plane. 
     The dishwasher may further include a cover configured to selectively cover the upper surface of the first body, and the cover may cover the first body in a state where an upper surface of the cover is parallel to the upper surface of the external support. 
     The cover may have a shape corresponding to a shape of the upper surface of the first body and a shape of the upper surface of the second body to selectively cover one of the upper surface of the first body and the upper surface of the second body. 
     The cover may be coupled to the first body to open or close the upper surface of the first body in a door type. 
     The rack may include a first rack and a second rack, the second body may include a first housing forming an exterior of the first rack, a second housing forming an exterior of the second rack, and a hinge connecting one side of the first housing and one side of the second housing to each other, and the other side of the first housing and the other side of the second housing may be selectively joined together or separated from each other. 
     The dishwasher may further include: a sensor configured to detect whether the second body is coupled; and a control processor configured to operate the washing pump based on a detection result of the sensor. 
     The dishwasher may further include a third body, and the second body may further include a joining member selectively joined to the third body. 
     The second body may further include a delivery channel configured to provide the water delivered from the supply channel to the third body. 
     The third body may further include a second spray nozzle configured to spray water, and a second washing channel configured to receive the water delivered from the delivery channel, the second washing channel being connected to the second spray nozzle. 
     The third body may further include a third rack configured to hold additional objects to be washed, and the second spray nozzle may spray the water onto the additional objects to be washed. 
     The second spray nozzle may also spray the water onto the object held on the rack of the second body to be washed. 
     The dishwasher may further include: a sensor configured to detect whether the second body and the third body is coupled; and a control processor configured to control the washing pump to be operated at a first strength while the second body is coupled to the first body, and to be operated at a second strength stronger than the first strength while the first body and the third body are sequentially coupled to one another. 
     The dishwasher may further include a cover having a shape corresponding to a shape of the upper surface of the first body, a shape of the upper surface of the second body, and a shape of the upper surface of the third body to selectively cover one of the upper surface of the first body, the upper surface of the second body, and the upper surface of the third body. 
    
    
     
       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 embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG.  1    is a perspective view illustrating a dishwasher installed on an external support according to an embodiment of the disclosure; 
         FIG.  2    is a perspective view illustrating a second body according to an embodiment of the disclosure; 
         FIG.  3    is a plan view illustrating a first body according to an embodiment of the disclosure; 
         FIG.  4    is a bottom view illustrating the first body according to an embodiment of the disclosure; 
         FIG.  5 A  is a cross-sectional view illustrating the first body and the second body of the dishwasher according to an embodiment of the disclosure; 
         FIG.  5 B  is a cross-sectional view illustrating the first body and a cover of the dishwasher according to an embodiment of the disclosure; 
         FIGS.  6 A and  6 B  are cross-sectional views each illustrating a drainage structure between the first body and the second body according to an embodiment of the disclosure; 
         FIGS.  7 A and  7 B  are perspective views each illustrating the first body and the cover according to an embodiment of the disclosure; 
         FIG.  8    is a plan view illustrating the second body according to an embodiment of the disclosure; and 
         FIG.  9    is a perspective view illustrating the second body and a third body according to an embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments of the disclosure will be described in more detail with reference to the accompanying  FIGS.   1  to  9   . The embodiments to be described below will be embodiments most suitable for understanding the technical features of the disclosure. Such embodiments do not limit the technical features of the disclosure, but exemplify that the disclosure may be implemented like the embodiments to be described below. 
     Therefore, the disclosure may be variously modified within the technical scope of the disclosure through the embodiments to be described below, and such modifications will fall within the technical scope of the disclosure. In addition, concerning the reference signs provided in the accompanying drawings to help the understanding of the embodiments to be described below, related components among components having the same function between the embodiments are denoted by the same or extending reference numerals. 
     The disclosure provides a dishwasher having an improved structure to improve both usability of installation space and washing power. 
     The dishwashers according to various embodiments of the disclosure are advantageous in that washing power can be improved by increasing a volume of a machine room and usability of installation space can be improved. 
       FIG.  1    is a perspective view illustrating a dishwasher  10  installed on an external support according to an embodiment of the disclosure. 
     Referring to  FIG.  1   , the dishwasher  10  may include a first body  100 , a second body  200 , a third body  300 , and a fourth body  400 . Specific structures of the first body  100  to the fourth body  400  will be described in detail below. 
     The first body  100  may include an upper housing  140  coupled to an opening formed in an upper surface of the external support to position the first body at a lower end of the upper surface of the external support. As a result, the first body  100  may be installed on the external support  15  such as a furniture cabinet. 
     Although it is illustrated as an example, for convenience of explanation, that the first body  100  is installed in a counter of the furniture cabinet that is the external support  15 , the installation structure of the first body  100  is not limited thereto, and the first body  100  including the upper housing  140  may be fixed to any type of external support  15 . 
     As in the embodiment of  FIG.  1   , the upper housing  140  may have a structure to contact the upper surface of the external support  15  around the opening in which the first body  100  is positioned. As a result, the first body  100  is fixed by the upper housing  140 , and the upper housing  140  is fixed to the external support  15 , thereby fixing an upper portion of the first body  100  to the external support  15 . 
     The upper surface of the external support  15  contacting the upper housing  140  may have a separate support groove corresponding to a shape of the upper housing  140 , and the support groove may have the same height as the upper housing  140 . Therefore, the upper surface of the external support  15  to which the upper housing  140  is coupled may maintain a smooth plate shape without a curve. 
     Although not illustrated in the drawings, the upper housing  140  may be coupled to the counter of the external support  15  in a sliding manner. 
     The upper housing  140  may be fixed inside the external support  15  to support a side surface or a lower surface of the first body  100 . In this case as well, the upper housing  140  may have a structure to fix the first body  100  and position an upper surface of the first body  100  in the opening of the upper surface of the external support  15 , so that the first body  100  is not exposed to the upper surface of the external support  15 . 
     For a built-in dishwasher, it is required to make a space by completely decoupling a part of a storage closet of the furniture cabinet that is the external support  15 , and the storage closet needs to be reformed elaborately such that its upper surface serves as a support. In addition, if a width of a furniture cabinet designed to be disassembled does not exactly match the specifications of the dishwasher, it is required to reform three or more pieces of the furniture cabinet to install the dishwasher. In a case where the dishwasher is replaced after the furniture cabinet is reformed, there are more restrictions. 
     In the dishwasher  10  according to an embodiment of the disclosure, it is only needed to provide an opening in the counter of the furniture cabinet, which is the upper surface of the external support  15 , in accordance with the specifications of the upper housing  140  of the first body  100  in a reformed manner. Therefore, a dishwasher in this type may be more convenient to install than a dishwasher in built-in type. 
     In addition, a built-in dishwasher and a counter-top dishwasher, which are generally used for home use, have limitations in increasing a volume of a machine room in which a motor, a pump, etc. are disposed. In contrast, in the dishwasher  10  according to an embodiment of the disclosure, only the first body  100  including a sump  110 , a circulation pump  117 , a washing pump  105 , etc. is positioned inside the furniture cabinet, thereby making it possible to form the first body  100  to have a relatively larger volume than those in other types of dishwashers. As a result, it is possible to improve the performance of the dishwasher  10  by increasing a water spraying power of the dishwasher  10  and enhancing a washing power and a drying power. 
     Therefore, due to the feature in which the first body  100  is positioned in the opening of the upper surface of the external support  15 , the dishwasher  10  according to the disclosure can secure a larger volume of the machine room than a conventional dishwasher for home use, resulting in an improvement in performance, and is more convenient to install than a dishwasher in built-in type. 
     The second body  200  may be coupled to or decoupled from the upper surface of the first body  100 . The structures of the second body  200  to the fourth body  400  may be different from each other, or may be similar or identical to each other. 
     Although not illustrated in the drawings, racks and spray nozzles in the second body  200  to the fourth body  400  may have different structures to be distinguishably used, for example, according to types of dishes that are objects to be washed. 
     For convenience of explanation, a component coupled to the first body  100  will be referred to as the second body  200 , a component coupled to the second body  200  will be referred to as the third body  300 , and a separated component will be referred to as the fourth body  400 . 
     The second body  200  may be connected to the first body  100  for supply and drainage of water. The second body  200  may be selectively fixed to the first body  100 , by forming the upper surface of the first body  100  and the lower surface of the second body  200  to have a corresponding shape and contact each other, or by including a connecting member such as a joint or a curve. 
     The second body  200  may be fixed to the first body  100  when the dishwasher  10  is in operation, and may otherwise be used for various purposes such as a dish drying rack or a dish storage box while being separated from the first body  100 . 
     Since the second body  200  is detachable and the first body  100  is positioned inside the furniture cabinet that is the external support  15 , the dishwasher  10  according to the disclosure does not always occupy a space on the counter of the furniture cabinet, making it possible to improve the space utilization of the counter. 
     Since the second body  200  is fixed to or separated from the upper surface of the first body  100  positioned in the opening of the counter, when moving objects to be washed from the counter to the dishwasher  10 , the second body  200  may be moved only in a horizontal direction on the counter. 
     Therefore, a user does not need to move a rack  210  filled with objects to be washed in a vertical direction to use the dishwasher  10  as in an in-sink dishwasher or a built-in dishwasher, which is advantageous in that the user does not bear the load of the rack  210  filled with the objects to be washed. 
     In addition, the second body  200  may be detachable and easily movable, which is advantageous in that the dishwasher  10  can be used in an easy way, because the user brings the second body  200  directly onto a table, puts used dishes into the second body  200 , and fixes the second body  200  to the first body  100 , rather than collecting the used dishes, moving the used dishes to a position near the dishwasher  10 , and then placing the used dishes on the rack  210 . 
       FIG.  2    is a perspective view illustrating the second body  200  according to an embodiment of the disclosure. 
     Referring to  FIG.  2   , the second body  200  may include a rack  210 , a first spray nozzle  220 , a first washing channel  230 , and a delivery channel  240 . 
     The rack  210  may hold objects to be washed. The rack  210  may have a shape to hold objects to be washed. Also, the rack  210  may be coupled to or decoupled from the second body  200 , and may include a separate holder for holding a spoon or a baby bottle. 
     The objects to be washed by the dishwasher  10  may include, but are not limited to, not only dishes such as bowls, plates, and cups, and cutlery such as spoons, chopsticks, knives, and forks but also frying pans, pots, and ladles. 
     The rack  210  may enable the objects to be washed to stand in a tilted state to cause water sprayed from an upper surface or a lower surface thereof to evenly contact each of the objects to be washed throughout its entire area. 
     The rack  210  may be made of a material having high thermal conductivity with rigidity, such as a synthetic material, e.g., metal or plastic. 
     The first spray nozzle  220  may spray water onto objects to be washed. The first spray nozzle  220  may include a plurality of nozzles, and may spray water at a strong pressure. The first spray nozzle  220  may have various shapes to evenly spray the water onto the objects to be washed. 
     The first spray nozzle  220  may be disposed below the rack  210  to spray water in an upward direction as illustrated in  FIG.  2   , or may be disposed above the rack  210  to spray water downward, or may also be disposed to extend to a side surface of the rack  210  to evenly spray water onto the objects to be washed. 
     The first spray nozzle  220  may have a washing wing shape as illustrated in  FIG.  2   . The wing-shape structure may be divided into two opposite sides and may rotate about its central portion. The rotation of the first spray nozzle  220  may be realized by the pressure at which the water is delivered. The first spray nozzle  220  may change a rotation direction to spray the water onto the objects to be washed in a different direction, thereby increasing the washing power. 
     The spraying direction and the spraying pressure of the first spray nozzle  220  may be controlled by the washing pump  105  of the first body  100 , and the washing pump  105  may be controlled by a control processor  550  of the dishwasher  10 . 
     The first washing channel  230  may be connected to the first spray nozzle  220  to supply water. The first washing channel  230  may receive the water supplied from a supply channel  120  of the first body  100 , and may supply the water to the delivery channel  240  if the third body  300  is connected to the second body  200 . A relationship between the first washing channel  230  and the delivery channel  240  will be described with reference to  FIG.  9    below. 
       FIG.  3    is a plan view illustrating the first body  100  according to an embodiment of the disclosure. 
     Referring to  FIG.  3   , the first body  100  may include a supply channel  120 , a drain port  160 , and a coupling housing  130 . 
     The supply channel  120  may receive the water delivered from the washing pump  105 , and supply the water to the first washing channel  230  in a state where the second body  200  is coupled to the first body  100 . 
     Although not illustrated in the drawings, the supply channel  120  may have a separate opening/closing device. An opening/closing operation of the supply channel  120  may be controlled by a user or by the control processor  550 . Alternatively, the supply channel  120  may be provided with a separate opening/closing stopper. The opening/closing stopper may be opened when the supply channel  120  is coupled to the first washing channel  230  of the second body  200  to couple the first body  100  to the second body  200 , and the opening/closing stopper may be closed when the supply channel  120  is decoupled from the first washing channel  230 . 
     For example, since the supply channel  120  is basically a one-way flow channel through which water moves only upward, an opening/closing structure is formed at an end of the supply channel  120  to be pushed only downward, so that water is not supplied upward in a state where the second body  200  is not coupled to the first body  100 , and the first washing channel  230  of the second body  200  is connected to the supply channel  120  by pushing the opening/closing structure downward, thereby structurally preventing in advance a problem that water is sprayed from the supply channel  120  when the second body  200  is not coupled to the first body  100 . 
     The drain port  160  may accommodate the water having been used for washing the objects to be washed in the second body  200  as the water is delivered to the first body  100 , and may include a separate filtering structure. 
     Like a filter net in a sink drain, the filtering structure filters out solid matter such as food contained in the water, and allows only the water to pass through the first body  100 . The filtering structure protrudes upward from the first body  100  to prevent the drain port  160  from being clogged. 
     The drain port  160  may be opened and closed either manually or by the control processor  550 , but the opening/closing of the drain port  160  may be realized in a structurally easy way by coupling the first body  100  and the second body  200  to each other as illustrated in  FIGS.  5 A and  5 B  to be described below. 
       FIG.  4    is a bottom view illustrating the first body  100  according to an embodiment of the disclosure. 
     Referring to  FIG.  4   , the first body  100  includes a sump  110 , a washing pump  105 , a circulation channel  115 , a circulation pump  117 , etc., and may further include a heating device, a control processor  550 , a detergent storage box, and a rinse storage box, etc. 
     Hereinafter, circulation of water in a structure including the sump  110 , which corresponds to the machine room of the dishwasher  10 , will be described. 
     The water introduced through a water supply pipe  113  is stored in the sump  110 . The water is delivered from the sump  110  to the supply channel  120  by the washing pump  105 , and the water is sprayed at a high pressure from the first spray nozzle  220  of the second body  200  according to a pressure level of the washing pump  105  during a washing process to wash the objects to be washed. The sprayed water may fall after being used for washing the objects to be washed, and then may be delivered back to the first body  100  through the drain port  160 . 
     The delivered water may be drained directly to the outside, or may be stored in the sump  110 . The circulation pump  117  may circulate the water stored in the sump  110  through the circulation channel  115 , and purify the water through a filter. The filth purified by the filter may be discharged to the outside. 
     During the washing process, the detergent storage box and the rinse storage box may deliver a detergent and a rinse to the water. 
     In the washing process, the above-described process is repeated one or more times, and the water is circulated by the sump  110  when used. 
     A drying method may be a hot air drying method in which hot air is applied and circulated, or a latent heat drying method in which latent heat is used by spraying high-temperature water. 
     The heating device may heat water and spray the heated water to increase a temperature of the objects to be washed, so that residual moisture is removed by latent heat. The high-temperature water may have a sterilizing effect. 
     Through these washing, sterilizing, and drying processes, the dishwasher  10  washes objects to be washed. Therefore, the performance of the dishwasher  10  may be determined by the configuration including the washing pump  105  and the sump  110  installed in the machine room. 
     In particular, the washing pump  105  is a structure including a motor. In order to improve the performance of the washing pump  105 , a large-volume motor and pump structure has been required. 
     In general, in a built-in dishwasher and a counter-top dishwasher, which are commonly used at home, a washing tub accommodating objects to be washed takes up a lot of space. In order to increase a capacity for accommodating objects to be washed, there is a limit in securing the volume of the machine room. 
     As a result, there has not been enough space to accommodate a sump  110  and a washing pump  105  each having a large volume with improved performance, resulting in a deterioration in washing power, which is a purpose of the dishwasher  10 . Accordingly, a home-use dishwasher, which has a weak cleaning power, has required a user to wash the objects to be washed in advance for primary washing and put them into the dishwasher  10 . 
     However, in the dishwasher  10  according to the disclosure, by separating the first body  100  containing the sump  110  and the washing pump  105 , etc. from the second body  200  for accommodating objects to be washed, and disposing only the first body in the furniture cabinet that is the external support  15 , the sump  110  and the washing pump  105  can be provided in a larger size in the same furniture cabinet, which is advantageous in improving a washing power and a drying power. 
       FIG.  5 A  is a cross-sectional view illustrating the first body  100  and the second body  200  of the dishwasher  10  according to an embodiment of the disclosure. 
     Referring to  FIG.  5 A , the first body  100  may further include a drain port  160 , a coupling housing  130 , and a fixing plate  155 , and the second body  200  may further include a drain housing  270 . 
     The water delivered from the second body  200  may flow into the drain port  160 . The drain port  160  may be disposed in a predetermined area of the first body  100 , and may be connected to the sump  110 , or the water may be directly delivered to the circulation channel  115  for a filtering process. 
     The drain housing  270  may have an opening at a position opposite to the position of the drain port  160  to induce the water to be discharged from the second body  200  to the first body  100  and delivered directly to the drain port  160 . 
     The drain housing  270  may have a shape to protrude downward, and may form a flow path to enable the water to flow thereinto. The drain housing  270  may have a step shape as illustrated in  FIGS.  6 A and  6 B , but is not limited thereto, and may be inclined at an angle or have a funnel shape. 
     Due to the protruding shape of the drain housing  270 , the drain housing  270  may have a structure to push the valve  150  downward to be fixed to the coupling housing  130  to couple the second body  200  to the first body  100 . This structure will be described with reference to  FIGS.  6 A and  6 B  below. 
       FIG.  5 B  is a cross-sectional view illustrating the first body  100  and a cover  500  of the dishwasher  10  according to an embodiment of the disclosure. 
     Referring to  FIG.  5 B , the dishwasher  10  may further include a cover  500  capable of selectively covering the upper surface of the first body  100 . 
     The cover  500  may be coupled to the upper surface of the first body  100  from which the second body  200  is decoupled, to cover the first body  100  and the drain port  160 . The shape and the structure of the cover  500  are not limited, but the cover  500  may have a structure to be coupled and fixed to the coupling housing  130  of the first body  100 . The cover  500  will be described in detail with reference to  FIGS.  7 A and  7 B . 
       FIGS.  6 A and  6 B  are cross-sectional views each illustrating a drainage structure between the first body and the second body  200  according to an embodiment of the disclosure. 
     Referring to  FIGS.  6 A and  6 B , the first body  100  may further include a valve  150 , and the second body  200  may further include a fixing groove  260 . 
     The valve  150  may be disposed at an upper portion of the drain port  160  to selectively open or close the upper portion of the first body  100 . 
     The valve  150  may have a structure to entirely open or close the drain port  160 , or may be disposed at the upper portion of the drain port  160  as illustrated in  FIG.  6 A  to open or close the upper portion of the first body  100 , thereby opening or closing the drain port  160  existing in the first body. 
     The valve  150  may have a structure to move downward when external pressure is applied thereto, and move upward back when the pressure is eliminated. 
     The movement of the valve  150  may be controlled by a user or by the control processor  550 , or the valve  150  may be structurally moved due to its elastic force. 
     The valve  150  may open or close the upper portion of the first body  100 . When the second body  200  is coupled to the first body  100 , the valve  150  may move downward to form a flow path between the drain housing  270  and the drain port  160 . 
     Although not illustrated in the drawings, when the second body  200  is coupled to the first body  100  in a state where one side of the valve  150  is fixed to the first body  100 , the other side of the valve  150  may be pushed downward to form a flow path between the drain housing  270  and the drain port  160 . 
     If the drain port  160  is open at all times, odors may come out of the water delivered after being used for washing as well as filth, or foreign substances may flow into the sump  110  and cause malfunction. Therefore, the valve  150  may move only when the second body  200  is coupled to the first body  100  to form a flow path to the drain port  160 , and close the flow path to close the drain port  160  when the second body  200  is decoupled from the first body  100 . 
     Although not illustrated in the drawings, when the second body  200  is coupled to the first body  100  in a state where one side of the valve  150  is fixed to the first body  100 , the other side of the valve  150  may be pushed downward to form a flow path between the drain housing  270  and the drain port  160 . 
     The fixing plate  155  may be positioned above the center of the drain port  160 , and an upper surface of the fixing plate  155  may have an area smaller than a cross-sectional area of the drain port  160 . When the second body  200  is decoupled from the first body  100 , the valve  150  may be positioned on a side surface of the fixing plate  155  by moving upward. 
     The fixing plate  155  may have a plate shape with its lower surface being supported by a column. Although not illustrated in the drawings, the fixing plate  155  may have a shape to be connected to the upper portion of the first body  100  to be supported laterally. 
     As illustrated in  FIG.  6 B , the fixing groove  260  may be formed in a central portion of the drain housing  270  and may have a bent shape corresponding to the shape of the fixing plate  155 . 
     When the second body  200  is connected to the first body  100 , the fixing groove  260  may fix the second body  200  in contact with the fixing plate  155 . In a state where the second body  200  is coupled to the first body  100 , the fixing groove  260  and the fixing plate  155  may serve as connecting members, while preventing the second body  200  from escaping. 
     The coupling housing  130  may be disposed at the upper portion of the first body  100 , and may have a shape to support the second body  200  when the second body  200  is connected to the first body  100  and surround the valve  150  when the second body  200  is disconnected from the first body  100 . 
     When the second body  200  is disconnected from the first body  100 , the fixing plate  155 , the valve  150 , and the coupling housing  130  may be positioned on the same plane. As a result, the first body  100 , from which the second body  200  is disconnected, can be disposed on the horizontally same plane as the counter of the furniture cabinet, which is the upper surface of the external support  15 . With this structure, when the user does not use the dishwasher  10 , the upper surface of the first body  100  can be used as a counter. 
     Therefore, unlike a counter-top dishwasher and a free-standing dishwasher, the dishwasher  10  according to the disclosure does not occupy a separate space in a kitchen, and does not restrict the use of the counter of the furniture cabinet, which is the upper surface of the external support  15 , when the dishwasher  10  is not used, thereby making it possible to enhance space utilization in installing and using the dishwasher  10 . 
       FIGS.  7 A and  7 B  are perspective views each illustrating the first body and the cover  500  according to an embodiment of the disclosure. 
     As an example of the cover  500 , the cover  500  of  FIG.  5   b    may cover the upper surface of the first body  100  in a state in which the second body  200  is not coupled to the first body  100 , and prevent the drain port  160 , the supply channel  120 , etc. from being exposed to the outside. 
     The upper housing  140  may be fixed such that the upper surface of the first body  100  and the upper surface of the external support  15  are parallel to each other, and the upper surface of the first body  100  is positioned at a lower height than the upper surface of the external support  15 . 
     When the cover  500  covers the upper surface of the first body  100 , an upper surface of the cover  500  may be parallel to the upper surface of the external support  15 . Since the upper surface of the cover  500  is parallel to and flat with respect to the upper surface of the external support  15 , when the upper surface of the external support  15  is used in a state where the second body  200  is not coupled to the first body  100 , stuff can be placed on the upper surface of the cover  500 , and thus, the space utilization of the dishwasher  10  can be enhanced. Further, while the upper surface of the cover  500  is formed at the same height as the upper surface of the external support  15 , the upper surface of the external support  15  may form a flat plane. 
     As an example of the cover  500 , a cover  500  of  FIG.  7 A  may have a shape corresponding to the shape of the upper surface of the first body  100  and the shape of the upper surface of the second body  200  to selectively cover one of the upper surface of the first body  100  and the upper surface of the second body  200 . 
     When the dishwasher  10  according to the disclosure is operated by coupling the second body  200  to the first body  100 , the cover  500  may be attached to the upper surface of the second body  200  to prevent water from being sprayed to the outside. In addition, when the dishwasher  10  according to the disclosure is not operated by decoupling the second body  200  from the first body  100 , the cover  500  may cover the upper surface of the first body  100 . 
     As an example of the cover  500 , a cover  510  of  FIG.  7 B  may be coupled to the first body  100  to open or close the upper surface of the first body  100  in a door type. 
     One side of the cover  510  may be coupled to the upper surface of the first body  100  by a separate hinge to move upward or downward in an opening or closing manner. The cover  510  may cover the upper surface of the first body  100  in a state where the second body  200  is decoupled from the first body  100 , and may be opened by moving upward about the hinge only when the second body  200  is coupled to the first body  100 . 
     The cover  510  may be slidable to cover or open the upper surface of the first body  100  by sliding by a user or by the control processor  550 . 
     Like the valve  150  described above, the covers  500  and  510  of  FIGS.  5 B,  7 A, and  7 B  described above may close the drain port  160  to prevent odors that may come out of the drain port  160 , and to protect the sump  110  by blocking foreign substances from flowing into the sump  110 . 
     The covers  500  and  510  may increase the usability of the counter of the furniture cabinet, which is the upper surface of the external support  15 , making it possible to enhance the space utilization of the dishwasher  10 . 
       FIG.  8    is a plan view illustrating the second body  200  according to an embodiment of the disclosure. 
     The rack  210  may include a first rack  213  and a second rack  215 , the second body  200  may include a first housing  212  forming an exterior of the first rack  213 , a second housing  214  forming an exterior of the second rack  215 , and a hinge  217  connecting one side of the first housing  212  and one side of the second housing  214  to each other, and the other side of the first housing  212  and the other side of the second housing  214  may be selectively joined together or separated from each other. 
     The second body  200  may be opened by the hinge  217  to increase convenience in taking objects to be washed into or out of the rack  210 . Even in a case where the second body  200  is decoupled from the first body  100  for use as a dish drying rack and the dish rack  210 , its usability can be increased. 
     Although not illustrated in the drawings, the rack  210  may be separated from the second body  200 , and may have a different design and a different racking structure to secure aesthetics. Also, the rack  210  may be independently used as a dish rack  210  to exhibit additional functions. 
     Although not illustrated in the drawings, the dishwasher  10  according to an embodiment of the disclosure may further include a sensor  540  and a control processor  550 . 
     The sensor  540  may detect whether or not the second body  200  is connected to the first body  100 , and the control processor  550  may operate the washing pump  105  based on a detection result of the sensor  540 . 
     The control processor  550  may control the operations of the washing pump  105 , the circulation pump, the valve  150 , the water supply pipe  113 , etc. 
     The sensor  540  may transmit the detection result to the control processor  550 , and the control processor  550  may operate the dishwasher  10  immediately. Alternatively, the control processor  550  may be used as a safety sensor based on the detection result of the sensor  540  to prevent malfunction of the dishwasher  10  when the second body  200  is not connected to the first body  100 . 
     The sensor  540  may display the detection result on a control panel. When a user inputs an operation through the control panel, the control processor  550  may operate the washing pump  105 , the circulation pump  117 , etc. on the basis of an input value. 
       FIG.  9    is a perspective view illustrating the second body  200  and the third body  300  according to an embodiment of the disclosure. 
     Referring to  FIG.  9   , the second body  200  may further include a joining member  250 . 
     The second body  200  and the third body  300  may be selectively joined together by the joining member  250 . 
     As illustrated in  FIG.  9   , the joining member  250  may be a housing in a structure having a joining groove to allow a lower surface of the third body  300  is joined to the upper surface of the second body  200 . Alternatively, the joining member  250  may a joint formed to fix the third body  300  to the second body  200 . 
     The third body  300  may also include a joining member, and the fourth body  400  may be joined to the third body  300  although not illustrated in the drawings. The joining members of the second body  200  and the third body  300  may have the same shape. 
     The delivery channel  240  may provide the water delivered from the supply channel  120  to the third body  300 . Like the supply channel  120  of the first body  100 , the delivery channel  240  may include a separate opening/closing device, and an opening or closing operation may be controlled by a user or by the control processor  550 . 
     Although not illustrated in the drawings, the delivery channel  240  may have an opening/closing structure to be opened or closed, based on whether the delivery channel  240  is coupled to a second washing channel  330  of the third body  300 , to couple the second body  200  to the third body  300 . 
     The third body  300  may include a second spray nozzle  320  for spraying water and a second washing channel  330  receiving the water delivered from the delivery channel  240  and connected to the second spray nozzle  320 . 
     The third body  300  may further include a third rack  310  for holding additional objects to be washed. The second spray nozzle  320  may spray the water onto the additional objects to be washed. 
     The second spray nozzle  320  may have the same shape as the first spray nozzle  220 . The second spray nozzle  320  may be disposed at an upper portion of the third rack  310  to spray the water downward, or may be disposed to extend to a side surface of the third rack  310  to evenly spray the water onto objects to be washed. 
     The second spray nozzle  320  may have a structure to spray the water onto the objects held on the rack  210  of the second body  200  to be washed. As a result, the objects to be washed on the rack  210  of the second body  200  can be washed with the water sprayed from the first spray nozzle  220  and the second spray nozzle  320 . 
     Although not illustrated in the drawing, the sensor  540  may detect whether or not each of the second body  200  and the third body  300  is connected, and the control processor  550  may control the washing pump  105  to be operated at a first strength when the second body  200  is connected to the first body  100 , and to be operated at a second strength larger than the first strength when the first body  100  to the third body  300  are sequentially connected to one another. 
     In an embodiment of the disclosure in which the third body  300  is included, the cover  500  may have a shape corresponding to an upper surface of the third body  300  as well as the upper surface of the first body  100  and the upper surface of the second body  200  to selectively cover the upper surface of the third body  300  as well. 
     When the third body  300  is coupled to the second body  200 , additional objects to be washed can be washed. This makes it possible to change a capacity for accommodating objects to be washed of the dishwasher  10  according to the disclosure. 
     As an example, each of the second body  200  and the third body  300  may have a capacity for accommodating objects to be washed for one person. For washing after using dishes for one person, only the second body  200  may be coupled. When the number of objects to be washed increases, not only the third body  300  but also the fourth body  400  may be coupled. That is, it is possible to adjust the number of dishes that the dishwasher  10  is capable of washing at once. 
     The capacity-changeable dishwasher  10  can reduce power consumption and water consumption caused when a large-capacity dishwasher  10  is operated to wash a small number of objects to be washed. 
     Even though the number of objects to be washed increases, a strong washing power can be secured by securing a capacity for the machine room as described above, which supplements the disadvantage of the conventional dishwasher  10 . Therefore, the dishwasher  10  can be used from single-person households to multi-person households, while minimizing power consumption and water consumption. 
     In addition, since the second body  200  and the third body  300  can be detached freely, the second body  200  and the third body  300  can be easily replaced. Furthermore, even if a failure occurs in the machine room of the first body  100 , the machine room can be easily opened and parts can be repaired to deal with the failure. 
     Although diverse embodiments of the disclosure have been each individually described above, each of the embodiments is not necessarily implemented alone, and the configuration and operation of each of the embodiments may be implemented in combination with at least one other embodiment. 
     In addition, although the preferred embodiments of the disclosure have been illustrated and described above, the disclosure is not limited to the specific embodiments as described above, and may be variously modified by those skilled in the art to which the disclosure pertains without departing from the gist of the disclosure as claimed in the appended claims. Such modifications should not be individually understood from the spirit or prospect of the disclosure.