Patent Publication Number: US-11039729-B2

Title: Dishwasher

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage application under 35 U.S.C. § 371 of International Application No. PCT/KR2017/008420, filed on Aug. 3, 2017, which claims the benefit of Korean Application No. 10-2016-0099558, filed on Aug. 4, 2016. The disclosures of the prior applications are incorporated by reference in their entirety. 
     TECHNICAL FIELD 
     The present invention relates to a dishwasher, and more particularly, to a dishwasher including an air jet generator for generating an air bubble therein. 
     BACKGROUND ART 
     A dishwasher is a household appliance that removes foreign matter remaining on a cleaning target object by spraying washing water on the cleaning target object. The dishwasher sprays washing water to the cleaning target object accommodated in a rack according to a cleaning course selected by a user to remove the dirt from the cleaning target object. 
     As a method for effectively removing foreign matter adhered to the dishes, a method of using a detergent having a strong cleaning ability, a method of increasing the spraying pressure of the washing water can be utilized, or a method of containing an air bubble in the washing water may be utilized. 
     The washing water containing the air bubble generates free radicals having excellent sterilizing power and chemical decomposing ability while the air bubble is dissipated, thereby effectively removing foreign matter adhered to the dishes. 
     However, in the air bubble, as the size of the bubble becomes smaller, the total interfacial area becomes larger, the surfacing speed becomes slower, and internal pressure becomes larger, thereby having an excellent adsorption of hydrophobic molecule, and increasing the availability of gas. 
     In the process of washing the dishes, since the foreign matter adhered to the dishes falls down to the bottom surface of the tub, the bottom surface of the tub can be easily contaminated by the fallen foreign matter. 
     The washing water flowing in the dishwasher is supplied from the sump to a spray nozzle and is sprayed to the dishes. Therefore, the washing water having the air bubbles should flow to the sump. When the washing water having the air bubbles is introduced into the sump through the bottom surface of the tub, the bottom surface of the tub may be cleaned together with the dishes. In addition, when the washing water falls to the bottom surface of the tub, the pressure of the falling washing water is added. Thus, the bottom surface of the tub can be effectively cleaned. 
     DISCLOSURE 
     Technical Problem 
     It is an object of the present invention to provide a dishwasher which cleans tableware with washing water containing air bubbles while removing contamination on the bottom surface of a tub. 
     It is an object of the present invention to provide a dishwasher which can perform chemical washing on the bottom surface of a tub with washing water containing air bubbles while performing mechanical washing with washing water falling from a certain height. 
     It is an object of the present invention to provide a dishwasher which can supply washing water containing air bubbles into a tub by utilizing a structure disposed in the outer surface of the tub. 
     It is an object of the present invention to provide a dishwasher which forms air bubbles in washing water by sucking outside air without a separate apparatus for injecting air. 
     It is an object of the present invention to provide a dishwasher which forms air bubbles in washing water by using a conventional pump for dishwashing without a separate pump for supplying washing water to an air jet generator for forming air bubbles. 
     The object of the present invention is to provide a dishwasher which forms air bubbles of minute size by crushing the air bubbles formed in the washing water to the utmost. 
     The problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description. 
     Technical Solution 
     In an aspect, there is provided a dishwasher, including: a tub in which a dish washing space is formed; a sump which contains washing water supplied into the tub; a spray module which sprays washing water toward dishes; a pump which supplies the washing water stored in the sump to the spray module; an air jet generator which receives a part of the washing water discharged from the pump to form an air bubble in the washing water; and a discharge module which discharges the washing water containing the air bubble discharged from the air jet generator to a side surface of the tub, thereby cleaning the bottom surface of the tub by supplying washing water containing air bubbles to the side surface of the tub. 
     A side surface hole for discharging the washing water introduced into the discharge module into the tub is formed on a side surface of the tub, and the side surface hole is formed at a height of being equal to or less than half a full height of the tub, thereby minimizing the amount of washing water flowing along the side surface. 
     The discharge module includes: a main discharge pipe to which the washing water discharged from the air jet generator is introduced; a tub discharge pipe which is connected to the main discharge pipe and connected to the tub; and a sealer which seals a space between the main discharge pipe and the tub discharge pipe, thereby stably supplying the washing water containing the air bubbles to the side surface of the tub. 
     The main discharge pipe includes: a first main discharge pipe which is connected to the air jet generator; and a second main discharge pipe which connects the first main discharge pipe and the tub discharge pipe, wherein the first main discharge pipe and the second main discharge pipe are coupled by a fusion method. 
     The first main discharge pipe forms a first flow path change coupling portion where a flow path cross-section is vertically extended to one side at a portion where the first main discharge pipe is coupled with the second main discharge pipe, the second main discharge pipe forms a second flow path change coupling portion where a flow path cross-section is vertically extended to one side at a portion where the second main discharge pipe is coupled with the first main discharge pipe, and the first flow path change coupling portion is coupled with the second flow path change coupling portion to form a bent flow path in a flow path of the first main discharge pipe. 
     The dishwasher further includes a side surface structure disposed outside the side surface of the tub, and the side surface structure includes: a tub discharge flow path which is connected to the discharge module and flows washing water; and a discharge port which discharges the washing water flowing in the tub discharge flow path into the tub, thereby supplying the washing water containing the air bubbles to the tub by utilizing the side surface structure disposed outside the tub. 
     The dishwasher further includes a generator connection port which is disposed at a lower end of the tub discharge flow path and is connected to the discharge module, thereby connecting the discharge module and side surface structure. 
     The discharge module is configured of a main discharge pipe which connects the air jet generator and the tub discharge flow path. 
     The main discharge pipe includes a discharge pipe fixing portion which fixes the discharge module to a cabinet that forms an external shape of dishwasher, thereby minimizing the influence of vibration of the air jet generator. 
     The air jet generator includes: an impeller which applies centrifugal force to the washing water that flows; a decompression portion which decreases a pressure of the washing water that passed through the impeller; an air suction portion which injects air into the decompression portion; a pressing portion which increases pressure so as to crush the air introduced from the air suction portion; and an air tap which has a plurality of holes so as to crush the air contained in washing water that passed through the pressing portion, thereby forming air bubbles of minute size in the washing water. 
     The details of other embodiments are included in the detailed description and drawings. 
     Advantageous Effects 
     According to an air jet generator of a dishwasher of the present invention, there are one or more of the following effects. 
     First, the dishwasher according to the present invention discharges the washing water containing the air bubbles through the side surface of the tub to flow into the sump through the bottom surface of the tub, which is advantageous in that the washing water containing the air bubbles can clean the dishes while cleaning the bottom surface of the tub. 
     Secondly, in the dishwasher according to the present invention, the washing water containing the air bubbles is discharged from the side surface of the tub and dropped onto the bottom surface of the tub, so that the bottom surface of the tub is cleaned by the air bubbles and a physical cleaning due to the drop of the washing water is added, which is advantageous in that the bottom of the tub can be effectively cleaned. 
     Third, the air jet generator of the dishwasher according to the present embodiment branches a part of the washing water supplied from the pump and generates air bubbles in the washing water through a branched flow, which is advantageous in that the air bubbles occur continuously when the pump of the dishwasher is operated for washing dishes. 
     Fourth, there is an advantage that an air bubble can be generated at a low pressure by using a pump disposed inside a conventional dishwasher without using a separate pump. 
     Fifth, there is an advantage that some of the flow branched from the pump rotates along the impeller vane, air is sucked and crushed along the air crushing pipe, and the amount of generated air bubbles is maximized while passing through the air tap. 
     Sixth, there is also an advantage that the washing water that passed through the air jet generator to the side surface of the tub by utilizing the side surface structure such as a water jacket disposed in the side surface of the tub. 
     The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the claims. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic front cross-sectional view of a dishwasher according to an embodiment of the present invention. 
         FIG. 2  is a block diagram illustrating a flow of washing water in a dishwasher including an air jet generator according to an embodiment of the present invention. 
         FIG. 3  is an exploded perspective view of an air jet generator according to the present embodiment. 
         FIG. 4  is a side cross-sectional view for explaining an internal flow path of an air jet generator according to the present embodiment. 
         FIG. 5  is a diagram for explaining the disposition of an air jet generator according to the present embodiment. 
         FIG. 6  is a diagram for explaining a side disposition of an air jet generator according to the present embodiment. 
         FIG. 7  is a block diagram of a dishwasher including an air jet generator and a high pressure pump according to another embodiment of the present invention. 
         FIG. 8  is a diagram illustrating a structure in which a discharge module is connected to a side surface of a tub according to an embodiment of the present invention. 
         FIG. 9  is a diagram illustrating a discharge module directly connected to a tub according to an embodiment of the present invention. 
         FIG. 10  is an exploded view of a configuration of a discharge module used in  FIG. 9  according to an embodiment. 
         FIG. 11  is an exploded view of a configuration of a discharge module used in  FIG. 9  according to another embodiment. 
         FIG. 12  is a diagram illustrating a side surface structure for forming a tub discharge path and a discharge module connected to the side surface structure according to another embodiment of the present invention. 
         FIG. 13A  is a diagram illustrating a frame which is a configuration of the side surface structure used in  FIG. 12 . 
         FIG. 13B  is a diagram illustrating a guide cover which is a configuration of the side surface structure used in  FIG. 12 . 
         FIG. 14  is a diagram for explaining a height of a discharge port according to an embodiment of the present invention. 
         FIG. 15  is a diagram illustrating a side surface structure and a discharge module connected to the side surface structure according to another embodiment of the present invention. 
         FIG. 16  is a diagram illustrating an inflow pipe and a discharge module that include a fixing portion according to an embodiment of the present invention. 
         FIG. 17  is a diagram illustrating a state in which the inflow pipe and the discharge module of  FIG. 16  are disposed in a dishwasher. 
     
    
    
     MODE FOR INVENTION 
     Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In describing the present embodiment, the same designations and the same reference numerals are used for the same components, and further description thereof will be omitted. 
     Hereinafter, an air jet generator of a dishwasher according to embodiments of the present invention will be described with reference to the drawings. 
       FIG. 1  is a schematic front cross-sectional view of a dishwasher according to an embodiment of the present invention. 
     Referring to  FIG. 1 , the dishwasher  10  according to the present embodiment includes a cabinet assembly  12  which forms an outer shape, a rack  22  which is disposed inside the cabinet assembly  12  and on which the dishes are placed, a spray module  24  which is disposed inside the cabinet assembly  12  and sprays washing water toward the dishes, a sump  20  which is disposed inside the cabinet assembly  12  and supplies washing water to the spray module  24 , a water supply module  38  which supplies water to the sump  20  or the spray module  24 , a drainage module  32  which is connected to the sump  20  and discharges the washing water to the outside, and a filter assembly  30  which is installed in the sump  20  and filters the washing water. In addition, the dishwasher  10  may further include a heater module  42  which is installed in the sump  20  and heats the washing water. 
     The cabinet assembly  12  forms an outer shape of the dishwasher, and includes a cabinet  14 , a door  16  coupled to the cabinet  14  for opening and closing the cabinet  14 , and a tub  18  which is installed inside the cabinet  14  and to which washing water or steam is applied, 
     The rack  22  is installed inside the tub  18 , and the dishes are placed on the rack  22 . 
     The spray module  24  is implemented to spray washing water toward the dishes. The spray module  24  includes a spray nozzle  26  and a nozzle flow path  28  for supplying washing water to the spray nozzle  26 . 
     A plurality of spray nozzles  26  may be disposed, and a plurality of nozzle flow paths  28  corresponding to the spray nozzle  26  may be disposed. In addition, a nozzle flow path switching portion  44  for selectively supplying washing water to the nozzle flow path  28  may be disposed. 
     In the present embodiment, the spray module  24  is configured to receive the washing water from the sump  20  storing the washing water and spray the washing water. However, unlike the present embodiment, water may be directly supplied through the water supply module  38 . 
     The water supply module  38  can be configured to receive water from the outside and supply the water to the sump  20 , and can be configured to supply water to the sump  20  through the filter assembly  30 . In addition, in the dishwasher, the water stored in a water storage portion of a water jacket  400  (see  FIG. 12 ) described below can be supplied to the sump  20 . 
     The discharge module  32  is implemented to discharge the washing water stored in the sump  20  to the outside, and includes a drainage flow path  34  and a drainage pump  36 . 
     The filter assembly  30  is implemented to filter foreign matter such as food waste contained in the washing water, and is disposed in a flow path of the washing water flowing from the tub  18  into the sump  20 . 
     To this end, the sump  20  may be provided with a filter mounting portion where the filter assembly  30  is installed, and a filter flow path connecting the filter mounting portion and the inside of the sump  20  may be disposed. 
     The sump  20  is provided with a sump storage portion for storing the washing water therein, and further includes a pump  40  for pumping the stored washing water to the spray module  24 . 
     The pump  40  pumps the washing water stored in the sump  20  to the spray module  24 . The pump  40  is connected to the spray module  24  through a pump flow path. 
     The pump  40  according to the present embodiment supplies washing water to the air jet generator  100  in addition to the spray module  24  through a branch pipe  230 . The air jet generator  100  is supplied with washing water through a flow path branched from the pump, and sucks gas into the supplied washing water and crushes to generate minute air bubbles. The air jet generator  100  is connected to the tub  18 . When the pump is operated, the washing water having the air bubbles generated by the air jet generator  100  is supplied into the sump  20  via the tub  18 , and then, the washing water containing the air bubbles supplied to the sump  20  is pumped to the spray module  24 , thereby increasing cleaning power by using the washing water containing minute air bubbles so as to wash the dishes. 
     The sump  20  is connected to a steam flow path and a steam nozzle that spray the steam generated by the heater module  42  into the tub  18 . A valve (not shown) for intermitting steam may be installed in the steam flow path. Through the valve, the steam sprayed into the tub  18  may be intermitted and the amount of steam may be adjusted upon occasions. 
     Here, the steam generated in the sump  20  may be supplied into the tub  18  through the filter flow path and the filter mounting portion, not through the steam nozzle. The sump  20  may be connected to the tub  18  in both directions through the steam flow path and the filter flow path. 
       FIG. 2  is a block diagram illustrating a flow of washing water in a dishwasher including an air jet generator according to an embodiment of the present invention.  FIG. 3  is an exploded perspective view of an air jet generator according to the present embodiment.  FIG. 4  is a side cross-sectional view according to the present embodiment.  FIG. 5  is a diagram for explaining the disposition of an air jet generator according to the present embodiment.  FIG. 6  is a diagram for explaining a side disposition of an air jet generator according to the present embodiment.  FIG. 7  is a block diagram of a dishwasher including an air jet generator and a high pressure pump according to another embodiment of the present invention. 
     Referring to  FIG. 2 , the flow of washing water is described. The washing water stored in the sump  20  of the dishwasher  10  is supplied to the spray module  24  through the pump  40 , and flows into the sump  20  again through the tub  18 . In the dishwasher  10  according to the present embodiment, a part of the washing water that passed through the pump  40  flows into the air jet generator  100  which generates air bubbles in the washing water. 
     The air jet generator  100  is supplied with a part of the washing water discharged from the pump  40 . The air jet generator  100  generates air bubbles in the washing water by passing the introduced washing water, through an air tap  180  and an air crushing pipe  110  including an impeller  170 , an air suction portion  140 , a decompression portion  120 , and a pressing portion  130 . The washing water containing the air bubbles is discharged to tub  18  again and flows into the sump  20 . According to the present embodiment, the washing water is discharged to the side surface of the tub  18 . Therefore, when the pump  40  is operated due to the operation of the dishwasher  10 , air bubbles are generated in the washing water, and the washing water containing the air bubbles is introduced into the sump through the tub and then supplied to the spray module through recirculation. 
     Referring to  FIGS. 3 and 4 , the air jet generator  100  according to the present embodiment will be described. 
     The air jet generator  100  according to the present embodiment includes the impeller  170  for applying centrifugal force to the washing water that flows, the decompression portion  120  for reducing the pressure of the washing water that passed through the impeller, the air suction portion  140  which is opened to allow air to be introduced into the decompression portion, the pressing portion  130  for increasing a pressure to crush the air introduced from the air suction portion, and the air tap  180  having a plurality of holes for crushing the air contained in the washing water passed through the pressing portion. 
     The decompression portion  120  has a cross-sectional area of the flow path that is decreased in the traveling direction of the washing water. The pressing portion  130  is formed in such a manner that the rate of increase in the cross-section of the flow path per flow path length is larger than the rate of decrease in the cross-section of the flow path per flow path length of the decompression portion. The air suction portion  140  is disposed in a portion where the flow path area of the decompression portion  120  is decreased. 
     The decompression portion  120  and the pressing portion  130  form a single air crushing pipe  110 . 
     The air jet generator  100  is connected to an inflow pipe  210  for allowing a part of the washing water passed through the pump  40  to flow to the air crushing pipe  110 , and is connected to a discharge pipe  220  for discharging the washing water passed through the air crushing pipe  110 . 
     The discharge module  300  according to the present embodiment discharges the washing water introduced from the air jet generator  100  to the side surface  19  of the tub  18 . The discharge module  300  may be connected directly to the side surface of the tub  18  or may be disposed in the side surface of the tub  18  to supply the washing water containing air bubbles to the side surface of the tub  18  through the side surface structure forming a tub discharge flow path. 
     The discharge module  300  includes a main discharge pipe  310  connected to the air jet generator  100 . 
     The inflow pipe  210  is connected to the air crushing pipe  110  and sends part of the washing water discharged from the pump  40  to the air crushing pipe  110 . The discharge pipe  220  connects the air crushing pipe  110  and the sump  20  or the tub  18  to flow the washing water discharged from the air crushing pipe  110  to the tub  18 . 
     An inflow end surface  112  of the air crushing pipe  110  and an end surface of the inflow pipe  210  are coupled to each other in a fusing manner at a portion where they are in contact with each other. A discharge end surface  114  of the air crushing pipe  110  and the end surface of the discharge pipe  220  are coupled to each other in a fusing manner at a portion where they are in contact with each other. 
     Referring to  FIG. 4 , the impeller  170  is mounted in an impeller mounting portion  150  of the air crushing pipe  110  described below. The impeller  170  is disposed before the decompression portion  120  of the air crushing pipe  110  in the direction in which the washing water flows. Thus, the impeller  170  is not mounted in the impeller mounting portion  150  of the air crushing pipe  110  but may be disposed inside the inflow pipe  210  or between the decompression portion  120  and the inflow pipe  210 . 
     The impeller  170  according to the present embodiment is mounted and fixed to the impeller mounting portion  150 . The impeller  170  includes an impeller circumferential portion  172  having an annular outer shape and a vane  174  disposed inside the impeller circumferential portion  172  to apply centrifugal force to the washing water. The impeller circumferential portion  172  abuts against the impeller mounting portion  150  and is fixed. 
     The washing water passed through the impeller  170  rotates as it passes through the vane  174  to generate a swirling flow. The vane  174  of the impeller  170  applies a centrifugal force to the washing water flowing to the decompression portion  120 . The vane  174  of the impeller  170  may be fixed or rotated and applies centrifugal force to the washing water passing through the impeller  170 . 
     The air crushing pipe  110  includes the decompression portion  120  for decompressing the washing water and increasing the speed of the washing water and the pressing portion  130  in which the cross-sectional area of the flow path is drastically increased. The decompression portion  120  is provided with an air suction portion  140  which sucks air from a portion where the washing water is decompressed to form a negative pressure. 
     The air crushing pipe  110  further includes the impeller mounting portion  150  in which the impeller  170  is mounted and an air tap mounting portion  160  in which the air tap  180  is mounted. 
     The air crushing pipe  110  is disposed in the order of the impeller mounting portion  150 , the decompression portion, the pressing portion, and the air tap mounting portion  160  in the direction in which the washing water flows. The air suction portion  140  is formed at a portion where the flow path cross-sectional area of the decompression portion  120  is reduced. The air suction portion  140  forms a suction port opened upward at a portion where the decompression of the decompression portion  120  is terminated. 
     The impeller mounting portion  150  is connected to the end of the inflow pipe  210 , and the inner circumference of the impeller mounting portion  150  is formed to correspond to the outer circumference of the impeller circumferential portion  172  such that the impeller  170  is mounted and fixed to the impeller mounting portion  150 . 
     The decompression portion  120  is disposed in the next position of the impeller mounting portion  150  of the air crushing pipe  110  in the direction in which the washing water flows. The decompression portion  120  is a part of the air crushing pipe  110  through which the washing water that passed through the impeller  170  flows. In the decompression portion  120 , the cross sectional area of the flow path is decreased in the progress direction of the washing water such that the pressure of the washing water flowing through the decompression portion  120  is decreased and the speed is increased. 
     In the decompression portion  120 , the cross section of the flow path is gradually decreased in the progress direction of the washing water. 
     The decompression portion  120  forms an air suction portion  140  at a portion where the decompression is terminated. The air suction portion  140  is formed at a portion where the cross-section of the flow path of the decompression portion  120  is reduced. The air suction portion  140  forms an air suction port  142  opened toward the upper side of the dishwasher opposite to the ground to prevent the water from flowing toward the air suction portion and being accumulated even if the pump does not operate. 
     The air suction portion  140  forms an air suction port  142  opened upward from one side of the decompression portion  120 . The air suction portion  140  includes an air suction pipe  144  protruding from one side of the decompression portion  120  to form a flow path through which air is sucked therein. The air suction pipe  144  is connected to a connection pipe (not shown) connected to suck the outside air. The connection pipe is connected to the outside of the dishwasher  10  or into the tub  18 . The connection pipe may be coupled to the air suction pipe  144  in a fusing manner. 
     The air suction pipe  144  may be integrally formed with the connection pipe and directly connected to the outside of the dishwasher  10  or to the tub  18 . 
     In the decompression portion  120 , the area of the flow path is decreased toward the progress direction of the washing water so that the pressure of the washing water is lowered, and a negative pressure lower than the atmospheric pressure is formed at a portion where the suction port  42  of the air suction portion  140  is formed such that the outside air is sucked in by itself. The air sucked into the air crushing pipe  110  is primarily crushed by the speed and the swirling force of the washing water flowing inside the decompression portion  120 . The air suction unit  140  can be connected with an air pump (not shown) so as to inject more air into the air crushing pipe  110 . 
     The washing water containing the primarily crushed air flows to the pressing portion  130 . 
     The pressing portion  130  is disposed in the next part of the decompression portion  120  of the air crushing pipe  110  in the direction in which the washing water flows. The pressing portion  130  receives the washing water that passed through the decompression portion  120 . 
     The pressing portion  130  increases the pressure to such an extent that the air introduced from the air suction portion  140  is crushed. In the pressing portion  130 , the cross-sectional area of the flow path is rapidly increased in the direction in which the washing water flows so that the air contained in the washing water can be crushed. The increasing ratio (ΔH2/L2) of the radius of the flow path cross section per flow path length of the pressing portion  130  is larger than the decreasing ratio (ΔH1/L1) of the radius of the flow path cross section per flow path length of the decompression portion. 
     The flow path cross-sectional area of a discharge end portion of the pressing portion  130  is formed wider than the flow path cross-sectional area of an inflow end portion of the decompression portion  120 . The pressing portion  130  expands larger than the flow path cross-section of the inflow pipe  210  so that the air crushing through a pressure difference occurs effectively. 
     As the cross-sectional area of the flow path rapidly increases, the speed of the washing water decreases, and the pressure rapidly increases. Due to a sudden increase in pressure, the air in the washing water is secondarily crushed. 
     In the direction in which the washing water flows, a side end surface of the flow path of the pressing portion  130  increases like a curved line of a quadratic function, and then, is bent in a stepped shape and a side end surface of the flow path is widened. Since the cross section of the flow path of the pressing portion  130  is gradually expanded in a narrow section, air crushing in the washing water through the pressure difference effectively proceeds. 
     The air tap mounting portion  160  is disposed in the next position of the pressing portion  130  of the air crushing pipe  110  in the direction in which the washing water flows. The air tap mounting portion  160  maintains a constant flow path extended from the pressing portion  130 , and the air tap  180  is mounted inside the air tap mounting portion  160 . 
     The air tap  180  is mounted in the air tap mounting portion  160  of the air crushing pipe  110 . The air tap  180  is fixed to the air tap mounting portion  160 . The air tap  180  is disposed at a position spaced apart from the pressing portion  130  by a certain distance. 
     The air tap  180  has a disk shape, and is provided with a plurality of holes  182  penetrating the inside thereof. The washing water passed through the pressing portion  130  passes through the air tap. The air in the washing water is thirdly crushed while passing through the plurality of holes  182  formed in the air tap  180 . 
     The holes  182  formed in the air tab  180  are disposed closely to the disk-shaped air tab  180  at regular intervals. The air tap  180  may be provided with a hollowed type hole or a slot type hole elongated in the left and right direction. In addition, it may be a cross slot type hole in which an elliptical shape elongated in the vertical direction and an elliptical shape elongated in the left and right direction are combined. 
     In the hole  182  formed in the air tap  180 , as the contact area with the air bubble increases, the shearing force acting on the air bubble increases to increase the amount of generated air bubbles. Thus, the slot type hole is preferable to the hollowed type hole. However, when the size of the hole is excessively increased as in the case of the cross slot type, the air tap may have a reliability problem. Thus, it is preferable that the air tap  180  has a slot type hole. 
     When the hole of the air tap  180  having the slot type hole is elongated in the left and right direction, and the ratio of the vertical height to the horizontal length of the slot type hole is 1: 4 to 6, the amount of generated air bubbles increases, and it is also suitable for the reliability of the air tap. Thus, it is preferable that the ratio of the height to the horizontal length of the slot type hole is 1: 4 to 6. 
     As the washing water passes through the pressing portion  130 , the sucked air is secondarily crushed. The air tap  180  is spaced apart from the pressing portion  130  at a predetermined interval. When the air tab  180  is spaced from the pressing portion  130  at regular intervals, the sucked air is sufficiently secondarily crushed through the pressing portion  130 , and then, passes through the air tap  180  again, thereby increasing the amount of generated air bubbles. Therefore, it is preferable that the distance L 3  of the air tap  180  spaced from the pressing portion  130  maintains a distance of the diameter size D or more of the cross section of the air tap so as to maximize the amount of generated air bubbles. 
     As the thickness of the air tap  180  becomes thinner, the possibility of clogging due to foreign substances is lowered, and there is an advantage that mass production is easy. Since the effect of crushing the air is not significantly different depending on the thickness of the air tap  180 , it is preferable that the thickness of the air tab  180  is manufactured with a thickness ranging from 2 to 5 mm. 
     The discharge pipe  220  has a shape in which a side end surface of the flow path is reduced at a portion where the washing water is introduced. In the discharge end of the air crushing pipe  110 , the flow path is expanded for the air crushing, and the discharge pipe  220  has a shape in which a side end surface of the flow path is reduced at a portion where the washing water is introduced, in order to reduce the size of the flow path volume of the discharge pipe  220  connected to the tub  18  or the sump  20 . 
     Referring to  FIG. 5 , the air jet generator  100  is disposed in the side surface of the lower portion of the dishwasher  10 . The air jet generator  100  sucks air, is disposed in the lower portion of the dishwasher  10  in consideration of vibration and noise generated in the process of forming the air bubbles, and is disposed in the side surface close to the pump  40  to minimize the flow path volume. 
     Referring to  FIG. 6 , the height (Oh) of the center of the discharge end of the pressing portion  130  from the lower end of the dishwasher  10  is disposed higher than the height (Ih) of the center of the inflow end of the decompression portion  130  from the lower end of the dishwasher  10 . Since the center of the discharge end of the air crushing pipe  110  is disposed higher than the center of the inflow end, even if the pump stops operating, residual water remaining in the air jet generator  100  is discharged to the inflow pipe  210 , so that the water is not accumulated inside the generator  100 . 
     Referring to  FIG. 7 , in the dishwasher  10  according to another embodiment of the present invention, the washing water stored in the sump  20  is supplied to the spray module  24  through the pump  40 , and flows into the sump  20  through the tub  18 . 
     The air jet generator  100  may be provided with washing water through a separate high pressure pump  240  without being connected to the branch pipe  230  branched from the pump  40 . Accordingly, the washing water stored in the sump  20  flows to the spray module  24  through the pump  40  or flows to the air jet generator  100  through the high pressure pump  240  to form an air bubble. 
     According to another embodiment of the present invention, when the dishwasher  10  includes a separate high pressure pump  240 , the pressure of the washing water flowing into the air crushing pipe  110  is strongly formed, which is advantageous in forming air bubbles. 
       FIG. 8  is a diagram illustrating a structure in which a discharge module is connected to a side surface of a tub according to an embodiment of the present invention.  FIG. 9  is a diagram illustrating a discharge module directly connected to a tub according to an embodiment of the present invention.  FIG. 10  is an exploded view of a configuration of a discharge module used in  FIG. 9  according to an embodiment.  FIG. 11  is an exploded view of a configuration of a discharge module used in  FIG. 9  according to another embodiment.  FIG. 12  is a diagram illustrating a side surface structure for forming a tub discharge path and a discharge module connected to the side surface structure according to another embodiment of the present invention.  FIG. 13  is a diagram illustrating a frame and a guide cover which are a configuration of the side surface structure used in  FIG. 12 .  FIG. 14  is a diagram for explaining a height of a discharge port according to an embodiment of the present invention.  FIG. 15  is a diagram illustrating a side surface structure and a discharge module connected to the side surface structure according to another embodiment of the present invention.  FIG. 16  is a diagram illustrating an inflow pipe and a discharge module that include a fixing portion according to an embodiment of the present invention.  FIG. 17  is a diagram illustrating a state in which the inflow pipe and the discharge module of  FIG. 16  are disposed in a dishwasher. 
     Referring to  FIG. 8 , the discharge module  300  according to the present embodiment discharges the washing water introduced from the air jet generator  100  to the tub  18 . The discharge module  300  connects the air jet generator  100  and the tub  18 , and, specifically, to the side surface  19  of the tub  18 . Since the washing water containing the air bubbles flows to the bottom of the tub along the tub side surface  19 , the dirt on the bottom of the tub is removed due to the air bubbles 
     A side surface hole  19   a  is formed in the side surface  19  of the tub  18 , and the washing water discharged from the air jet generator  100  is discharged into the tub through the side surface hole  19   a  formed on the side surface of the tub  18  through the discharge module  300 . 
     The discharge module  300  is directly connected to the side surface of the tub  18  or disposed in the side surface of the tub  18  and discharges the washing water from the side surface of the tub  18  through the side surface structure  400 ,  500  forming the tub discharge flow path  440  and  510 . The side surface structure  400 ,  500  may be a water jacket for supplying washing water to the sump  20 , or a drying duct for drying the dishes. 
     First, referring to  FIGS. 9 to 11 , a structure in which the discharge module  300  is directly connected to the side surface of the tub will be described. 
     Referring to  FIG. 9 , the discharge module  300  directly connects the air jet generator  100  and the tub  18 . The discharge module  300  is connected to the side surface hole  19   a  formed in the side surface of the tub. In one side of the side surface  19  of the tub  18 , the side surface hole  19   a  for discharging the washing water flowing in the discharge module  300  into the tub  18  is formed. 
     The discharge module  300  flows the washing water discharged from the air jet generator  100  into the tub  18  through the side surface hole  19   a  of the tub  18 . The washing water containing the air bubbles is discharged into the tub through the discharge module  300  and the side surface hole  19   a  and flows into the sump  20 . 
     Referring to  FIG. 10 , the discharge module  300  according to the present embodiment includes a main discharge pipe  310  to which the washing water discharged from the air jet generator is introduced, a tub discharge pipe  320  which connects the main discharge pipe  310  and the tub  18 , and a sealer  330  which seals a space between the main discharge pipe  310  and the tub discharge pipe  320 . 
     The main discharge pipe  310  is connected to the discharge end of the air jet generator  100 . In the main discharge pipe  310 , the cross section of the flow path is partially reduced in the flow direction of the washing water at a portion adjacent to the air jet generator  100 . Since maintaining the extended sectional area of the flow path in the pressing portion  130  is inefficient in utilizing a lower space, the discharge pipe  310  has a shape in which the side end surface of the flow path is reduced, at a portion where the washing water is introduced. 
     The inflow end of the main discharge pipe  310  and the discharge end of the air jet generator  100  are coupled in a fusing manner. 
     The main discharge pipe  310  is bent at some sections to be connected to the tub discharge pipe  320 . One side of the main discharge pipe  310  is connected to the air jet generator  100 , and the other side is connected to the tub discharge pipe  320 . 
     A part of the outer circumference of the main discharge pipe  310  is fitted into a part of the inner circumference of tub discharge pipe  320 . The sealer  330  is disposed between the main discharge pipe  310  and the tub discharge pipe  320 . The sealer  330  is disposed between the main discharge pipe  310  and the tub discharge pipe  320  and seals a portion where the main discharge pipe  310  and the tub discharge pipe  320  are coupled. 
     The tub discharge pipe  320  connects the main discharge pipe  310  and the tub  18 , and sends the washing water into the tub  18 . The tub discharge pipe  320  extends along the side surface  19  of the tub  18 , and is bent at a portion where the side surface hole  19   a  is formed and connected to the side surface hole  19   a.    
     The tub discharge pipe  320  forms a coupling portion  325  at a portion where the tub discharge pipe  320  is coupled with the main discharge pipe  310 . The coupling portion  325  is formed to be wider than the flow path cross-section of the tub discharge pipe  320  and has a size for surrounding the outer circumference of the main discharge pipe  310 . The outer circumference of the main discharge pipe  310  is fitted to the inner circumference of the coupling portion  325 . The sealer  330  is disposed between the inner circumference of the coupling portion  325  and the outer circumference of the main discharge pipe  310 . 
     Referring to  FIG. 11 , the main discharge pipe  310  may be configured of two pipes including a first main discharge pipe  310   a  and a second main discharge pipe  310   b . The first main discharge pipe  310   a  is a pipe connected to the air jet generator  100 . In a portion adjacent to the air jet generator  100 , the flow path cross-section is partially reduced in the flow direction of the washing water. The first main discharge pipe  310   a  is disposed in the lower side of the bottom surface of the tub  18  to be parallel to the bottom surface of the tub, or partially inclined. The first main discharge pipe  310   a  forms a first flow path change coupling portion  315   a  where the flow path cross-section is vertically extended to one side at a portion where the first main discharge pipe  310   a  is coupled with the second main discharge pipe  310   b.    
     The second main discharge pipe  310   b  connects the tub discharge pipe  320  and the first main discharge pipe  310   a . The second main discharge pipe  310   b  may include a partly bent section, but is disposed in parallel to the side surface of the tub as a whole. The second main discharge pipe  310   b  is connected to the tub discharge pipe  320 . The second main discharge pipe  310   b  forms a second flow path change coupling portion  315   b  where the flow path cross-section is vertically extended to one side at a portion where the second main discharge pipe  310   b  is coupled with the first main discharge pipe  310   a.    
     The first flow path change coupling portion  315   a  of the first main discharge pipe  310   a  and the second flow path change coupling portion  315   b  of the second main discharge pipe  310   b  are coupled to each other to form a vertical or curved flow path in the flow path of the first main discharge pipe  310   a.    
     The flow direction of the washing water is changed at a portion where the first main discharge pipe  310   a  and the second main discharge pipe  310   b  are coupled to each other. The first main discharge pipe  310   a  and the second main discharge pipe  310   b  are coupled by a fusing method at a portion where both pipes are abutted. The first flow path change coupling portion  315   a  and the second flow path change coupling portion  315   b  are coupled by a fusing method. 
     Hereinafter, a discharge module connected to the side surface structure will be described with reference to  FIGS. 12 to 15 . 
     Referring to  FIGS. 12 and 13 , the dishwasher according to the present embodiment may have the side surface structure  400  disposed outside the side surface  19  of the tub  18 . The side surface structure  400  according to the present embodiment may be a water jacket for supplying washing water. 
     A tub discharge flow path  440  is formed inside the side surface structure  400 , and a discharge port  450  for discharging the washing water flowing to the tub discharge flow path  440  into the tub is formed in one side of the tub discharge flow path  440 . In addition, the side surface hole  19   a  is formed in the tub  18  at a position corresponding to the discharge port  450 . 
     Referring to  FIG. 13 , the side surface structure  400  includes a frame  420  disposed to abut on the side surface  19  of the tub  18  and a guide cover  410  coupled to the frame in a shape corresponding to the frame  420 . The frame  420  and the guide cover  410  form both side surfaces of the side surface structure  400 , and form the tub discharge flow path  440  therein. 
     The frame  420  is provided with the discharge port  450  formed at a position corresponding to the side surface hole  19   a  of the tub  18 . The frame  420  of the water jacket may further include a tub hole  460  communicating with a water supply flow path inside the water jacket. The washing water introduced from the main discharge pipe  310  flows along the tub discharge flow path  440  and is discharged to the tub  18  through the discharge port  450 . 
     The tub discharge flow path  440  is connected to the main discharge pipe  310  at a lower portion. Inside the guide cover and the frame, the tub discharge flow path  440  through which the washing water introduced from the main discharge pipe  310  flows is formed. 
     A lower portion of the tub discharge flow path  440  includes a generator connection port  430  for connecting with the main discharge pipe  310 . The outer circumference of the main discharge pipe  310  is fitted to the inner circumference of the lower portion of the generator connection port  430 . A sealer for sealing may be disposed between the generator connection port  430  and the main discharge pipe  310 . 
     The main discharge pipe  310  may be integrally formed or formed of the first main discharge pipe  310   a  and the second main discharge pipe  310   b.    
     The height O of the discharge port  450  from the bottom surface of the tub  18  is equal to or less than half of the height M of the tub  18 . Therefore, the height of the side surface hole  19   a  is also formed in a portion of being equal to or less than half of the tub height. The height O of the discharge port  450  from the bottom surface of the tub  18  is formed to be lower than the height N of the tub hole  460  from the bottom surface of the tub  18 . 
     The height O of the discharge port  450  from the bottom surface of the tub  18  is formed to be equal to or less than half of the height M of the tub  18  so as to reduce the amount of the washing water that flows unnecessarily by reducing the length of the tub discharge flow path  440 . 
     Referring to  FIG. 15 , the side surface structure  500  disposed outside the side surface  19  of the tub  18  may be a drying duct for discharging the air of washing tub. Similarly, in the case of the drying duct, the tub discharge flow path  510  and the discharge port  520  are formed inside the drying duct, and the tub discharge flow path  510  is connected to the main discharge pipe  310  at the lower portion, so that the washing water containing air bubbles introduced from the air jet generator  100  is discharged into the tub  18 . 
     Hereinafter, a fixing portion formed in the inflow pipe and the discharge module will be described with reference to  FIGS. 16 to 17 . 
     Since any vibrations occur in the process of sucking and crushing the air, the air jet generator  100  includes a fixing portion  212 ,  312  for fixing the inflow pipe  210  and the discharge module  300  to the cabinet of the dishwasher. 
     The inflow pipe  210  includes an inflow pipe fixing portion  212  for fixing the inflow pipe  210 . The inflow pipe fixing portion  212  according to the present embodiment is fixed to the lower portion of the cabinet  14 . The discharge module  300  includes a discharge pipe fixing portion  312  for fixing the discharge module  300 . The discharge pipe fixing portion  312  according to the present embodiment is fixed to the side surface of the cabinet  14 . The discharge pipe fixing portion  312  is formed in the main discharge pipe  310  disposed adjacent to the air jet generator  100 . When the main discharge pipe  310  is divided into the first main discharge pipe  310   a  and the second main discharge pipe, it is preferable that the discharge pipe fixing portion  312  is formed in the second main discharge pipe  310   b  in that it is fixed at the side surface of the cabinet. 
     Although the exemplary embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Accordingly, the scope of the present invention is not construed as being limited to the described embodiments but is defined by the appended claims as well as equivalents thereto. 
     DESCRIPTION OF NUMERAL 
     
       
         
           
               
               
               
               
             
               
                   
               
             
            
               
                  10:  
                 dishwasher 
                  18: 
                 tub 
               
               
                  19:  
                 side surface 
                  20: 
                 sump 
               
               
                  40:  
                 pump 
                 100:  
                 air jet generator 
               
               
                 110:  
                 air crushing pipe 
                 120: 
                 decompression portion 
               
               
                 130:  
                 pressing portion 
                 140:  
                 air suction portion 
               
               
                 170:  
                 impeller 
                 180:  
                 air tap 
               
               
                 210:  
                 inflow pipe 
                 300:  
                 discharge module 
               
               
                 310:  
                 main discharge pipe 
                 320: 
                 tub discharge pipe 
               
               
                 330:  
                 sealer 
                 400, 500:  
                 side surface structure 
               
               
                 440, 510: 
                 tub discharge flow path