Patent Publication Number: US-11383210-B2

Title: Washing machine and micro-bubble generator thereof

Description:
TECHNICAL FIELD 
     The disclosure relates to a washing machine and a micro-bubble generator for the same. 
     BACKGROUND 
     A washing machine is a device for separating contaminants from laundry using wash water and detergent, and may separate contaminants from the laundry by chemical action using a detergent dissolved in the wash water and mechanical action of the wash water and an inner basket. 
     The detergent is usually put in with wash water and dissolved in the wash water during the washing process to remove the contaminants from the laundry by the chemical action. However, depending on the temperature and amount of the wash water, the amount of the introduced detergent, etc., the detergent may not dissolve in the wash water and may remain in the laundry. When the detergent is not sufficiently dissolved, cleaning action may not be sufficient, and accordingly, contaminants may remain in the laundry. Detergent or foreign matter remaining in the laundry may reduce the user&#39;s satisfaction and may cause skin troubles. 
     Various techniques have been proposed to eliminate the detergent or foreign matter remaining in laundry. For example, a micro-bubble method has been proposed. A micro-bubble refers to a small bubble having a diameter of a few micrometers to a few nanometers, and can be characterized as being invisible in water. Specifically, micro-bubbles may be generally understood as a concept collectively encompassing micro-bubbles having a diameter of 50 μm or less, micro/nano-bubbles (having diameters of 10 nm or more and less than 1 μm), and nano-bubbles (having diameters of less than 10 nm). Micro-bubbles have high internal pressures, so that if the micro-bubbles burst in the water, they may impact any nearby laundry, thereby effectively separating the detergent or foreign matter from the nearby laundry. 
     In order to generate the micro-bubbles, a micro-bubble generator is provided in the washing machine. Micro-bubble generators include a separate power device such as a compressor and a pump that may be directly used to generate the bubbles, and a flow characteristic that may be used without the separate power device. 
     However, since power-based micro-bubble generators may use a high-performance power device to generate the micro-bubbles, there are disadvantages in that the structure is complicated, the maintenance cost is high, the noise and vibration are serious, and the production unit cost is high. In contrast, mechanical micro-bubble generators (without the power device) have advantages in that the structure may be simple, the maintenance cost may be low, the noise and vibration may be relatively weak, and the manufacturing cost may be low. 
     However, in the case of a micro-bubble generator which does not use a power device, micro-bubbles generated in or through a flow path having a predetermined shape are discharged primarily to the outside of the micro-bubble generator, so that there is a disadvantage that is difficult to generate sufficient micro-bubbles. 
     In addition, in the prior art, after the micro-bubbles are generated, the wash water containing micro-bubbles is transferred to a predetermined discharging position using a hose. During the movement along the hose, the micro-bubbles disappear, so that there is a disadvantage in that the amount of micro-bubbles introduced into the inner basket (that substantially performs washing) is small. 
     SUMMARY 
     Various embodiments of the disclosure have been proposed in order to solve the above problems and provide a washing machine and a micro-bubble generator for the washing machine that can increase the amount of microbubbles and improve the washing power and the rinsing power of the washing machine. 
     Further, embodiments of the disclosure provide a washing machine and a micro-bubble generator for the washing machine that supply generated micro-bubbles to inside of the inner basket in which washing is performed without being extinguished. 
     In accordance with an aspect of the present invention, there is provided a washing machine, comprising: a cabinet; an outer basket in the cabinet and configured to accommodate wash water an inner basket in the outer basket and configured to accommodate laundry; a water supply valve unit in the cabinet and connected to an external water supply source to receive wash water; and a micro-bubble generator configured to receive the wash water from the water supply valve unit, generate micro-bubbles, and supply the micro-bubbles to a washing space (e.g., in the washing machine), wherein the micro-bubble generator includes a dissolving unit configured to mix or dissolve gas into the wash water from the water supply valve unit, and wherein the dissolving unit includes a water supply line connection connected indirectly to the water supply valve unit to introduce the wash water (e.g., to the dissolving unit); a supply hole providing a path in which gas is introduced into a dissolution space in the dissolving unit; and a dissolved water drain portion discharging the wash water in which gas is dissolved or mixed. 
     A partition wall may be in the dissolving unit, and the partition wall may partition the dissolution space into an inner dissolution space and an outer dissolution space. 
     The partition wall may extend a set distance upward from an inner bottom surface of the dissolving unit. 
     The partition wall may include a residual water discharge hole to drain the wash water remaining inside (e.g., the dissolving unit). 
     The dissolved water drain portion may be on or in an outer circumferential surface of the dissolving unit, and the residual water discharge hole may be oriented in a direction opposite to a direction in which the dissolved water drain portion is oriented. 
     The inner bottom surface of the dissolving unit inside the partition wall may be angled or inclined toward the residual water discharge hole. 
     The bottom surface inside the dissolving unit, but outside the partition wall, may be angled or inclined in a direction toward the dissolved water drain portion from the residual water discharge hole. 
     The micro-bubble generator may further include a nozzle unit attached to the dissolving unit configured to form micro-bubbles in the wash water from the dissolved water drain portion and discharge the same. 
     The nozzle unit may include a micro-bubble generator in the dissolved water drain portion and having a decomposition unit including a path through which the wash water flows; and a nozzle portion coupled to the dissolving unit so that the micro-bubble generator is fixed in the dissolved water drain portion, the nozzle portion being configured to discharge the wash water. 
     The decomposition unit may comprise a cone (e.g., a tube having a larger diameter along the direction of the wash water flow from the dissolving unit). 
     The nozzle unit may further include a gasket in the nozzle unit at an end of the micro-bubble generator and against an end of the dissolved water drain portion. 
     The dissolving unit may be above the inner basket. 
     The washing machine may further comprise a control unit configured to control components of the washing machine, including the water supply valve unit to supply the wash water to a flow path passing through the dissolving unit until a set time has elapsed, and when a set amount of the wash water has not been supplied at the set time, to supply the wash water with the wash water in a flow path not passing through the dissolving unit. 
     In accordance with another aspect of the present invention, there is provided a micro-bubble generator to be installed in a washing machine, configured to receive wash water, generate micro-bubbles and supply the wash water containing the micro-bubbles to an inner basket of the washing machine (e.g., where laundry is received). The micro-bubble generator includes a dissolving unit, and the dissolving unit includes a dissolving body having a cylindrical or tubular shape, an open upper end and a dissolved water drain portion at one side, configured to discharge wash water having mixed or dissolved gas therein; and a cap fastened to the open upper end of the dissolving body having a water supply line connection unit configured to receive the wash water, and a supply hole configured to introduce gas into a dissolution space in the dissolving body. 
     A partition wall in the dissolving unit may extend a set distance upward from an inner bottom surface of the dissolving unit. 
     The partition wall may include a residual water discharge hole oriented in a direction opposite to a direction in which the dissolved water drain portion is oriented. 
     The micro-bubble generator may further include a nozzle unit attached to the dissolving unit, configured to form micro-bubbles in the wash water from the dissolved water drain portion and discharge the same, and the nozzle unit may include a micro-bubble generator in the dissolved water drain portion and having a decomposition unit including a path through which wash water flows; and a nozzle portion coupled to the dissolving unit so that the micro-bubble generator is fixed in the dissolved water drain portion and configured to discharge wash water. 
     In accordance with yet another aspect of the present invention, there is provided a washing machine, comprising a cabinet; an outer basket in the cabinet and configured to accommodate wash water an inner basket in the outer basket and configured to accommodate laundry; a water supply valve unit in the cabinet and connected to an external water supply source to receive wash water; a micro-bubble generator configured to receive wash water from the water supply valve unit, generate micro-bubbles, and supply the micro-bubbles to a washing space (e.g., in the washing machine); and a control unit configured to control components of the washing machine, including the water supply valve unit to supply the wash water to a flow path passing through the dissolving unit until a set time has elapsed, and when a set amount of the wash water has not been supplied at the set time, to supply the wash water with the wash water in a flow path not passing through the dissolving unit. 
     The dissolving unit may include a water supply line connection unit connected indirectly to the water supply valve unit to introduce the wash water (e.g., to the dissolving unit); a supply hole providing a path in which gas is introduced into a dissolution space in the dissolving unit; and a dissolved water drain portion discharging wash water in which gas is dissolved or mixed. 
     A partition wall may be in the dissolving unit, may extend a set distance upward from an inner bottom surface of the dissolving unit, and may partition the dissolution space into an inner dissolution space and an outer dissolution space. The partition wall may include a residual water discharge hole configured to drain the wash water remaining inside the dissolving unit. 
     In a washing machine and a micro-bubble generator of a washing machine according to the embodiments of the disclosure, there is an advantage in that it is possible to increase the amount of micro-bubbles to be produced to improve the washing power and the rinsing power. 
     Further, there is an effect in that the generated micro-bubbles can be supplied to the inside of the inner basket where the washing is performed without being extinguished. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view showing a schematic configuration of an exemplary washing machine according to an embodiment of the disclosure; 
         FIG. 2  is a view showing a configuration of an exemplary micro-bubble generator; 
         FIG. 3  is a perspective view of an exemplary dissolving unit and nozzle unit; 
         FIG. 4  is an exploded perspective view of the dissolving unit and the nozzle unit in  FIG. 3 ; 
         FIG. 5  is a view of an upper portion of the cap in the dissolving unit of  FIG. 3 ; 
         FIG. 6  is a cross-sectional view taken along the line A-A in  FIG. 3 ; 
         FIG. 7  is a cross-sectional view taken along the line B-B in  FIG. 3 ; 
         FIG. 8  is a perspective view of an exemplary pressure regulating unit; 
         FIG. 9  is an exploded perspective view of the pressure regulating unit in  FIG. 8 ; 
         FIG. 10  is a sectional view taken along the line C-C in  FIG. 8 ; 
         FIG. 11  is a view showing a configuration of an exemplary micro-bubble generator according to another embodiment; 
         FIG. 12  is a cross-sectional view of a pressure regulating unit taken along the line D-D in  FIG. 11 ; 
         FIG. 13  is a view showing a schematic configuration of an exemplary washing machine according to another embodiment; 
         FIG. 14  is a view showing a configuration of an exemplary micro-bubble generator connected to a door gasket of the washing machine of  FIG. 13 ; 
         FIG. 15  is a perspective view of an exemplary nozzle unit; 
         FIG. 16  is an exploded perspective view of the nozzle unit of  FIG. 14 ; 
         FIG. 17  is a sectional view taken along the line E-E in  FIG. 15 ; 
         FIG. 18  is a block diagram showing a path to which wash water is supplied; and 
         FIG. 19  is a flowchart showing an exemplary process of supplying wash water in a washing machine. 
     
    
    
     DETAILED DESCRIPTION 
     A washing machine is for washing laundry, and various types of washing machines are known, including a top loading type washing machine, a front-loading type drum washing machine, and a hybrid type washing machine combining the top loading type and the front-loading type. Typically, such washing machines include an inner basket where laundry is received, an outer basket where the wash water is accommodated, a motor that drives the inner basket, and the like. 
     In one embodiment, the top loading type washing machine is described as an example, but an idea of the disclosure may be applicable to other types of washing machines. 
       FIG. 1  is a schematic view showing a washing machine according to an embodiment of the disclosure. 
     Referring to  FIG. 1 , a washing machine  1  according to an embodiment of the disclosure includes a cabinet  10  having an outer appearance, a base  12  coupled to a lower portion of the cabinet  10 , a cabinet cover  14  coupled to an upper portion of the cabinet  10 , and a door  16  which is coupled to the cabinet cover  14  and which may be opened or closed. 
     Specifically, the cabinet  10  may have upper and lower surfaces and may have or form one or more side surfaces of the washing machine  1 . The base  12  supporting the washing machine  1  may be on the lower side of the cabinet  10 , and a cabinet cover  14  may be coupled to the upper side of the cabinet  10 . The cabinet cover  14  on the upper side of the cabinet  10  may include an input hole for placing laundry into the washing machine  1 . In addition, a door  16  is on or above the cabinet cover  14 , and the door  16  may close or open the input hole for loading or unloading the laundry. The user may open or close the door  16  to load the laundry in the washing machine  1  when a washing process is to be performed, or unload the laundry when the washing process is completed, and may shield the laundry by covering the input hole with the door  16  when performing the washing process. 
     In addition, the washing machine  1  may include an outer basket  20 , which is housed in the cabinet  10  and which may contain wash water, and an inner basket  22 , which is in the outer basket  20  and which receives the laundry. The outer basket  20  and the inner basket  22  are inside the cabinet  10 , and the outer basket  20  and the inner basket  22  have a similar shape, wherein the inner basket  22  may have a diameter that is smaller than the diameter of the base  20  by a predetermined length. That is, the inner basket  22  may be spaced apart from the outer basket  20  by a predetermined distance on the inside of the outer basket  20 . A plurality of holes for fluid communication with fluid in the outer basket  20  may be in or around the inner basket  22 . The outer basket  20  and the inner basket  22  are in fluid communication with each other through the plurality of holes in the inner basket  22 , such that the wash water of the inner basket  22  may flow into the outer basket  20 . Likewise, the wash water of the outer basket  20  may flow into the inner basket  22 . The outer basket  20  and the inner basket  22  may have a cylindrical shape, but are not limited thereto. 
     The top-loading washing machine  1  as in the present embodiment may further include a pulsator  24 . The pulsator  24  may be joined to or integrated with the lower portion of the inner basket  22  to form a bottom surface of the inner basket  22 . The pulsator  24  is on the bottom of the inner basket  22  and forms a rotating flow and vortex in the wash water in the laundry space. As used herein, the laundry space is a space inside the outer basket  20 , and includes an inner space of the inner basket  22 . Accordingly, the laundry space refers to a space where the laundry and the wash water may be accommodated. The pulsator  24  is connected to a gear assembly  26  and may be rotated by a rotational force from the motor  28  through the gear assembly  26 . A strong vortex may be formed in the radial direction by the rotational force of the pulsator  24 , and the washing process may be performed while the wash water and laundry in the inner basket  22  are rotated by the strong vortex. During the washing process, the wash water between the inner basket  22  and the outer basket  20  may rise upwards due to the strong radial vortex in the inner basket  22 . Accordingly, the wash water circulates in the washing space, including the outer basket  20  and the inner basket  22 , during the washing time, and the laundry may be washed while the vortex is present. In some cases, as the pulsator  24  rotates, the inner basket  22  may or may not rotate together with the pulsator  24 . For example, when the inner basket  22  and the pulsator  24  are integral with each other, the inner basket  22  may rotate together with the pulsator  24  when the pulsator  24  rotates, but when the pulsator  24  and the inner basket  22  are separate and/or fastened to each other, only the pulsator  24  rotates to form the vortex. 
     Meanwhile, when the washing machine  1  includes a drum  22 ′ ( FIG. 13 ) without the pulsator  24 , the gear assembly  26  and the motor  28  may be connected directly to the outer basket  20  or the inner basket  22 . 
     Further, the washing machine  1  may include a detergent container  30 , a water supply valve unit  32 , a main drain hose  34  and a main drain valve  36 . 
     The detergent container  30  may have a drawer or tray shape that moves in the cabinet cover  14  in a sliding manner. As an example, the cabinet cover  14  may include a detergent container accommodating portion  15  ( FIG. 11 ), and the detergent container  30  may be in the detergent container accommodating portion  15 . The detergent container  30  may include a space for the detergent and a space for a fabric softening agent. The detergent container  30  may be opened and closed by sliding it away from and toward the inside of the washing machine  1 , respectively, and a water supply valve unit  32  may be connected to an outer surface of the detergent container  30 . (Hereinafter, the space within the inner basket  22  where the laundry is received may be referred to as an “inner side,” and the surface[s] of the cabinet  10  forming the outer appearance of the washing machine  1  may be referred to as an “outer side”.) The wash water may be supplied to the detergent container  30  through the water supply valve unit  32  (which is connected to an external water supply source), then to the inner basket  22  through the detergent container  30 . Since the wash water is supplied to the inner basket  22  through the detergent container  30 , the wash water supplied to the inner basket  22  may contain a detergent or softening agent mixed or dissolved therein. 
     The water supply valve unit  32  may be on the cabinet cover  14  and may be connected to an external water supply source via an external hose (not shown) to receive the wash water from the external water supply source. The water supply valve unit  32  may be or comprise a four-way valve (not shown). Although not shown in the drawings, the four-way valve may include a hot water supply valve for supplying hot water, a cold water supply valve for supplying cold water, and a micro-bubble generating water supply valve for supplying cold water to generate micro-bubbles. The hot water supply valve may be in fluid communication with the space for the detergent. In addition, the cold water supply valve may be or comprise a two-way valve, one outlet of which is in fluid communication with the space for the detergent, and the other outlet of which is in fluid communication with the space for the softening agent. The micro-bubble generating water supply valve may be connected to a dissolving unit  100  for producing micro-bubbles. 
     Meanwhile, according to one or more embodiments, the water supply valve configured to generate the micro-bubbles may be omitted. In this case, a cold water feed valve or hot water feed valve may be connected directly to the dissolving unit  100  to supply the wash water. 
     The main drain valve  36  may be at a lower portion (e.g., a lowermost surface) of the outer basket  20  and may control discharge of the wash water from the outer basket  20 . Specifically, the main drain valve  36  may communicate with the lower portion of the outer basket  20 , and the main drain hose  34  may be connected to the main drain valve  36 . When the wash water used for washing is discharged to the outside, the main drain valve  36  may be opened to discharge the wash water through the main drain hose  34 , and when the wash water is supplied for performing the washing process, the main drain valve  36  may be closed to allow the wash water to be received in the outer basket  20  and the inner basket  22 . 
     In addition, the washing machine  1  may include a control unit  40  and an operation unit  42 . The operation unit  42  may include a user interface unit on the cabinet cover  14  and be configured to input a predetermined command by the user or output certain information to the user. The control unit  40  may control components of the washing machine including the motor  28 , the pulsator  24 , the water supply valve unit  32 , the operation unit  42 , and the like. For example, when the user sets a washing course, a washing time, and the like through the operation unit  42 , the control unit  40  may control the motor  28 , the pulsator  24 , the water supply valve unit  32  or the like to perform the washing process corresponding to the settings. 
     Meanwhile, the washing machine  1  may include a micro-bubble generator configured to receive wash water from the water supply valve unit  32 , generate micro-bubbles, and supply the micro-bubbles to a washing space. The micro-bubble generator may include a dissolving unit  100  and a nozzle unit  200  ( FIG. 2 ). 
     In addition, the washing machine  1  may include a water supply line L 1  in  FIG. 2  and a leaked water discharge line L 2  in  FIG. 2  for interconnecting the micro-bubble generator. The water supply line L 1  may supply the wash water to the dissolving unit  100 , and the leaked water discharge line L 2  may connect the dissolving unit  100  with the nozzle unit  200  outside the dissolving unit  100  to provide wash water (e.g., excess wash water) from the dissolving unit  100  the nozzle unit  200 . 
     The dissolving unit  100  may dissolve or mix gas into the wash water from the water supply valve unit  32 . In this embodiment, the gas is exemplified by air in the dissolving unit  100 , but the gas may be from a gas providing means (not shown), or a mechanism connected to or provided along with the dissolving unit  100 . 
     The dissolving unit  100  may receive the wash water from the water supply line L 1  connected to the water supply valve unit  32  and may generate bubbles in the wash water using the water supply pressure of the wash water from the water supply line L 1  without using a power unit. In other words, the gas in the dissolving unit  100  may be dissolved or mixed in the wash water supplied into the dissolving unit  100 , thereby generating bubbles in the wash water. The dissolving unit  100  may be above the inner basket  22  and on the upper portion of the washing machine  1 . As an example, the dissolving unit  100  may be fixed to the cabinet cover  14 . 
     The nozzle unit  200  may generate the micro-bubbles from water and gas in the dissolving unit  100  by supplying the wash water with gas. Specifically, the nozzle unit  200  may generate the micro-bubbles by splitting the bubbles generated as the gas dissolves, mixes or disperses in the wash water in the dissolving unit  100 . This nozzle unit  200  may be connected at or near the input hole, and the wash water with the micro-bubbles therein may be directed into the inner basket  22  immediately after the micro-bubbles are formed. The micro-bubbles in the nozzle unit  200  gradually disappear over time or when they move along a predetermined flow path. In the present embodiment, as soon as the micro-bubbles are generated in the nozzle unit  200 , the micro-bubbles are discharged into the inner basket  22 . As a result, the amount of micro-bubble extinction may be minimized, and the effect of micro-bubble-containing wash water may be improved. 
     Hereinafter, a specific configuration of a micro-bubble generator according to an embodiment of the disclosure will be described with reference to the drawings. 
       FIG. 2  is a view showing a configuration of an exemplary micro-bubble generator suitable for the washing machine shown in  FIG. 1 ,  FIG. 3  is a perspective view of an exemplary dissolving unit and an exemplary nozzle unit of the exemplary micro-bubble generator shown in  FIG. 2 ,  FIG. 4  is an exploded perspective view of the exemplary dissolving unit and the exemplary nozzle unit in  FIG. 2 ,  FIG. 5  is a view of the upper portion of the cap of the exemplary dissolving unit,  FIG. 6  is a cross-sectional view taken along the line A-A in  FIG. 3 ,  FIG. 7  is a cross-sectional view taken along the line B-B in  FIG. 3 ,  FIG. 8  is a perspective view of the exemplary pressure regulating unit in  FIG. 2 ,  FIG. 9  is an exploded perspective view of the exemplary pressure regulating unit in  FIG. 8 , and  FIG. 10  is a sectional view taken along the line C-C in  FIG. 8 . 
     Referring to  FIGS. 2 to 10 , the micro-bubble generator may include the dissolving unit  100  and the nozzle unit  200 , as described above. 
     First, the dissolving unit  100  may receive the wash water and dissolve or mix the gas therein in the wash water. The dissolving unit  100  may be above the cabinet  10 . As an example, the dissolving unit  100  may be fixed to the inner side wall of the cabinet cover  14 . Hereinafter, the upper and/or lower direction(s) may mean the direction of gravity with reference to  FIG. 1 , and may be referred to as a vertical direction. Furthermore, the left and right direction(s) with reference to  FIG. 1  may be referred to as a horizontal direction or a direction parallel to the paper surface. 
     Further, the dissolving unit  100  may be adjacent to the water supply valve unit  32 . 
     Herein, referring to  FIGS. 2 to 7 , the dissolving unit  100  may include a dissolving body  110  and a cap  150  coupled to the top of the dissolving body  110 . 
     The dissolving body  110  may have a tubular or cylindrical shape with an open upper end to receive the gas and wash water and to provide a dissolution space in which the gas is dissolved or mixed in the wash water. The term “dissolution space” refers to the space in which the wash water and the gas meet within the outer tube  510  to dissolve the gas. The dissolving body  110  may include a dissolved water drain portion  111  and a cap fixing portion  112 . 
     The dissolved water drain portion  111  may supply the wash water in which the gas is dissolved or mixed to the nozzle unit  200 , and may be on the outer circumferential surface of the dissolving body  110 . In particular, the dissolved water drain portion  111  may be on the lower portion of the outer circumferential surface of the dissolving body  110 . 
     The cap fixing unit  112  may be on the upper end of the dissolving body  110  and coupled with the dissolving body  110  and the cap  150  together. The cap fixing unit  112  may be or comprise a rib or lip extending outward along the outer circumferential surface of the upper end of the dissolving body  110 . In addition, the cap fixing unit  112  may have a groove into which the lower end portion of the cap  150  is inserted. 
     A cabinet fixing unit  113  may be provided on the outer surface of the dissolving unit  100 . The cabinet fixing unit  113  is configured to fix the dissolving unit  100  to the cabinet  10  and may be fastened to the cabinet  10 . As an example, the cabinet fixing unit  113  may have a hole extending from the outer surface of the dissolving body  110  into which bolts or the like are inserted for fastening. The cabinet fixing unit  113  may be fastened to the inside of the cabinet cover  14 . 
     A partition wall  120  ( FIG. 4 ) may be inside the dissolving unit  100 . The partition wall  120  extends a set distance upward from an inner bottom surface of the dissolving unit  110 . The partition wall  120  may have a length corresponding to the vertical direction length of the dissolving body  110  so that the upper end or edge of the partition wall  120  may correspond to the upper end or edge of the dissolving body  110 . At least a portion of the outer circumference of the partition wall  120  may be spaced apart from the inner circumferential surface of the dissolving body  110 . For example, substantially the entire outer surface of the partition wall  120  may be spaced apart from the inner surface of the dissolving body  110 . However, the outer surface of the partition wall  120  is not limited to being spaced apart from the inner surface of the dissolving body  110 . For example, one side of the partition wall  120  may be in contact with the inner surface of the dissolving body  110 , and another side may be spaced apart from the inner surface of the dissolving body  110 . The dissolution space in the inner surface of the dissolving body  110  may be partitioned into an inner dissolution space and an outer dissolution space by the partition wall  120 . 
     Herein, the volume of the inner dissolution space on the inner side of the partition wall  120  may be smaller than the volume of the outer dissolution space on the outer side of the partition wall  120 . For example, the volume of the inner dissolution space may be less than one-third of the volume of the outer dissolution space. For example, the distance from the center of the inner side of the dissolving body  110  to the partition wall  120  may be less than the distance from the center of the inner side of the dissolving body  110  to the inner surface of the dissolving body  110 . Thus, the amount of gas dissolved or mixed into the wash water in the dissolving unit  100  may be increased. Specifically, the gas in the dissolution space may be dissolved or mixed in the wash water supplied to the inner side of the partition wall  120  through the water supply line connection unit  151 , and substantially, the gas may be dissolved or mixed while moving the wash water overflowing from the partition wall  120  to the outer dissolution space. That is, as the volume difference between the dissolving body  110  and the partition wall  120  increases, a space for storing the gas in the dissolving body  110  and a space where the gas is dissolved or mixed may increase. In this case, the inner diameter of the inner dissolution space may be twice or more the inner diameter of the space inside the water supply part  151 . Accordingly, in relation to the amount of wash water supplied to the water supply unit  151 , the inner dissolution space overflows the wash water to the outer dissolution space when a proper amount of wash water is received so that the bubbles may be effectively generated. When the inner diameter of the inner dissolution space is smaller than twice the inner diameter of the water supply portion  151 , the amount of wash water in the inner dissolution space and overflowing to the outer dissolution space is reduced, and the bubble generation amount is not effectively achieved. 
     When the wash water supplied from the water supply line connection unit  151  is supplied to the inner side of the partition wall  120 , and the wash water overflows from the partition wall  120 , the wash water may fall into the outer dissolution space between the partition wall  120  and the dissolving body  110 . In this case, the gas may be dissolved or mixed in the wash water in the dissolution space to generate bubbles. 
     The partition wall  120  may have a residual water discharge hole  121  therein. The residual water discharge hole  121  is a hole configured to drain wash water remaining inside the partition wall  120 . The residual water discharge hole  121  is at the lower portion of the partition wall  120 . For example, the residual water discharge hole  121  may be at the lowermost end of the partition wall  120 . The diameter of the residual water discharge hole  121  may be smaller than the diameter of the upper end opening of the partition wall  120 . Thus, the amount of wash water flowing into the partition wall  120  may be larger than the amount of wash water flowing through the drain, and the wash water may overflow the partition wall  120 . 
     The bottom side of the inner side of the dissolving body  110  on the inner side of the partition wall  120  may have a different height, depending on the regions. Specifically, the bottom surface of the inner side of the dissolving body  110  inside the partition wall  120  may have the lowest region in contact with the residual water discharge hole  121 . For example, the bottom side of the inner side of the dissolving body  110  inside the partition wall  120  may have a downward inclination toward the residual water discharge hole  121 . In addition, the bottom of the inner side of the dissolving body  110  inside the partition wall  120  may be connected to the residual water discharge hole  121  and may have a residual water guide groove  122  in a shape crossing the inner side bottom surface of the dissolving body  110 . The residual water guide grooves  122  may have the form of a groove shaped downwardly from the bottom of the inner side of the adjacent dissolving body  110 . The residual water guide groove  122  has a set length and one end configured to interface with the residual water discharge hole  121  and another end extending to the partition wall  120  opposite from the residual water discharge hole  121 . Accordingly, the wash water remaining on the inner side of the partition wall  120  may be effectively discharged toward the residual water discharge hole  121 . 
     The residual water discharge hole  121  may be in a direction toward the center of the dissolved water drain portion  111  at the center of the inner side bottom surface of the partition wall  120  and toward a set angle (for example, 90 degrees or more). For example, the residual water discharge hole  121  may face the direction opposite from the dissolved water drain portion  111  by being opened at an angle of 180 degrees with respect to the direction of the dissolved water drain portion  111 . Accordingly, a flow path having a set length may be formed until the wash water discharged to the residual water discharge hole  121  is discharged to the dissolved water drain portion  111 . Thus, a sufficient amount of wash water supplied to the inner side of the partition wall  120  may flow into the outer dissolution space in a form that overflows through the upper end of the partition wall  120 . 
     Meanwhile, the bottom side of the inner side of the dissolving body  110  on the outer side of the partition wall  120  may also have a different height depending on the region. Specifically, the bottom surface of the inner side of the dissolving body  110  on the outer side of the partition wall  120  may have a highest region in contact with the residual water discharge hole  121 . For example, the bottom surface of the inner side of the dissolving body  110  on the outer side of the partition wall  120  may be downwardly inclined in the direction toward the dissolved water drain portion  111  from the residual water discharge hole  121 . Accordingly, the residual water discharged from the residual water discharge hole  121  may be smoothly guided to the dissolved water drain portion  111 . 
     The cap  150  may be fastened to the upper portion of the dissolving body  110  to shield an opening of the dissolving body  110 . As the cap  150  and the dissolving body  110  may be fastened, the movement of the gas may be blocked so that the gas may be stored in the dissolution space of the dissolving unit  100 , and thus the gas may be stored in the dissolving unit  100 . 
     The cap  150  may further include a water supply direction switching unit  152  and a cap connection unit  154  as well as the water supply line connection unit  151  described above. 
     Specifically, the cap  150  including the water supply line connection unit  151  and the water supply direction switching unit  152  may be connected to the upper end of the dissolving body  110  to shield the dissolving body  110 , the wash water may be supplied from the water supply line connection unit  151 , and the water supply direction switching unit  152  may switch the direction of the wash water flowing through the water supply line connection unit  151  towards the interior of the partition wall  120 . 
     The water supply line connection unit  151  may be connected to the water supply line L 1  to supply the wash water provided from the water supply valve unit  32  into the dissolving unit  100 . 
     The water supply line connection unit  151  may extend horizontally from the cap  150  to allow the wash water to be introduced horizontally into the cap  150 . Specifically, the wash water supplied from the water supply valve unit  32  at one side (for example, the upper side) of the dissolving unit  100  may have a flow direction switched at least once in order to be horizontally supplied to the water supply line connection unit  151 . Thus, the wash water may be introduced into the water supply line connection unit  151  in a horizontal direction, and then be switched inside the cap  150  and discharged to the inner space of the partition wall  120  in a vertical direction. 
     The water supply direction switching portion  152  may communicate with the discharging side or end of the water supply line connection unit  151 , and has at least a portion thereof that is oriented in the vertical direction at the end of the horizontally-oriented water supply line connection unit  151 . Thus, the supply direction switching portion  152  may switch the direction of the wash water from the water supply line connection unit  151  towards the partition wall  120 . 
     The water supply direction switching portion  152  may be at a position corresponding to the center of the partition wall  120 , such that the supplied wash water may be discharged into the partition wall  120 . 
     For example, the water supply line connection unit  151  and the water supply direction switching portion  152  may be at an angle of 90 degrees or in an ‘L’ shape. This ‘L’ shape can prevent the wash water from the water supply line L 1  from being directly injected into the partition wall  120 . The wash water may be uniformly supplied by passing through the ‘L’ shape. On the other hand, when the water supply line connection unit  151  has a shape allowing only a linear flow of wash water, the wash water is directly injected from the water supply line L 1 . When being supplied by direct injection, the water supply is discharged relatively less uniformly. As a result, the overflow of the wash water in the partition wall  120  may occur irregularly, and the dissolution of the gas in the dissolving unit  100  may not be performed smoothly. However, in accordance with the embodiment shown in  FIGS. 2-6 , the wash water spreads out relatively uniformly after colliding with the side wall of the water supply direction switching portion  152  and discharging into the inner tube, and the wash water may be relatively uniformly supplied to the partition wall  120 . Accordingly, it is possible to smoothly dissolve and/or mix the gas with the overflowing wash water. 
     Moreover, the water supply line connection unit  151  may be connected to an intermediate point of the water supply direction switching portion  152  along the vertical direction. Accordingly, the wash water supplied from the horizontal direction may enter the water supply direction switching portion  152  oriented in the vertical direction, may hit the inner wall of the water supply direction switching portion  152 , and may be spread out along the vertical direction of the water supply direction switching portion  152 . Specifically, the wash water may be not directly injected into the partition wall  120  by changing from the horizontal direction to the vertical direction, but may be spread in the vertical direction by colliding against the inner wall of the water supply direction switching portion  152 . Accordingly, the flow of the wash water may be made more uniform. Since the wash water is more uniformly supplied to the partition wall  120 , the gas in the dissolution space may be more uniformly supplied to the wash water, and the bubbles may be more uniformly formed. 
     In summary, the dissolving unit  100  may receive the wash water flowing from the water supply valve unit  32  in the horizontal direction and change the flow of the wash water to the vertical direction, and it is possible to prevent direct injection of water from the water supply valve unit  32  into the interior of the partition wall  120 . 
     The gas supply unit  170  may be spaced apart from the water supply line connection unit  151  and have a set angle with respect to the water supply direction switching unit  152 . The gas supply unit  170  may supply the gas into the internal space of the dissolving unit  100 . 
     The gas supply unit  170  may comprise at least in part a pipe and have a cylindrical shape and/or a set length. The gas (e.g., air) supply unit  170  may also have a curved part or portion that is connected to the cap  150 . For example, the gas supply unit  170  may include a cap fastening portion  171 , which extends upward from one end connected to the cap  150 , and a guide portion  172  that extends from the cap fastening portion  171 . The guide portion  172  may be bent at an interface with the cap fastening portion  171  and extend in a direction away from the cap fastening portion  171 . The cross-sectional area of the inner space of the cap fastening portion  171  may be larger than the cross-sectional area of the inner space of the guide portion  172 . 
     A gas supply unit fastening portion  160  may be formed in an upper portion of the cap  150 . The gas supply unit fastening portion  160  may be spaced apart from the water supply line connection unit  151  by a set angle and/or distance relative to the water supply direction switching unit  152 . The gas supply unit fastening portion  160  may include a plurality of fastening ribs  161  and a supply hole  162 . The fastening ribs  161  may be arranged in a ring shape corresponding to the inner surface of the cap fastening portion  171 . The fastening ribs  161  may have a set interval between adjacent ribs  161 . For example, four fastening ribs  161  may be provided along the circumference of the supply hole  162  with the set interval between adjacent ribs  161 . When the gas supply unit  170  is in the gas supply unit fastening portion  160 , the fastening rib  161  may be inserted into the air supply unit  170 , such that the air supply unit  170  is aligned with the cap  150  at a set position. 
     A sealing groove  163  having a ring shape may be on the outer side circumference of the fastening rib  161 . A gasket  164  having a shape corresponding to the sealing groove  163  may be in the sealing groove  163  between the cap  150  and the gas supply unit  170 . 
     The supply hole  162  may be in the region inside the fastening ribs  161 . The supply hole  162  may provide a path through which the gas from the gas supply unit  170  is supplied to the dissolution space. In addition, one or more supply holes  162  may be on the inside of the portion where the fastening ribs  161  are spaced apart from one another. For example, when four fastening ribs  161  are provided, four supply holes  162  may be in the space where the fastening ribs  161  is spaced apart from one another. 
     An opening and closing member (e.g., a valve)  180  may be between the cap  150  and the gas supply unit  170 . The opening and closing member  180  may comprise an elastically deformable material such as synthetic rubber, silicone, synthetic resin and the like. The opening and closing member  180  may include a shield unit (or stopper)  181  having a set area. The shield unit  181  may have an area larger than the area of the flow path in the guide portion  172  above the cap fastening portion  171 . The lateral area of the shield unit  181  may correspond to (e.g., be slightly smaller than) the inside region of the fastening ribs  161 , so that the opening and closing member  180  may move up and down in the space inside the cap fastening portion  171 . 
     When the wash water is supplied to the dissolving unit  100 , the internal pressure of the dissolving unit  100  increases as the internal space of the dissolving unit  100  fills with the wash water. In addition, due to the water pressure of the wash water flowing into the interior space of the dissolving unit  100 , a portion of the wash water may flow into the supply hole  162 . Thus, gas and/or wash water flowing in the direction of the bottom surface of the shield unit  181  and passing through the supply hole  162  may exert an upward force on the shield unit  181  so that the shield unit  181  may shield the gas supply unit  170  come into contact with the step in the cap fastening portion  171  or between the cap fastening portion  171  and the guide portion  172 . Otherwise, the opening and closing member  180  may move downward, and the may be supplied to the dissolving unit  100  through the open gas supply unit  170 . 
     The shield unit  181  may have a downward convex shape. The shield unit  181  may have a downward convex or upward concave shape. Thus, when pressure is applied to the opening and closing member  180  from the downward direction to the upward direction (i.e., from the dissolving unit  100  to the guide portion  172 ), the rim of the upper surface of the shield unit  181  may be elastically deformed to a certain level while contacting the upper inside surface of the cap fastening portion  171 , thereby shielding the flow path of the gas supply unit  170  and blocking gas inflow and wash water discharge into the guide portion  172 . In addition, when the opening and closing member  180  moves downward, the bottom surface of the opening and closing member  180  may be spaced apart from the supply hole  162  by a support protrusion or ring  166 , so that gas may be effectively supplied to the dissolving unit  100 . 
     The shield unit  181  may have a modulus of elasticity such that it does not enter the guide portion  172 , even when the wash water is supplied at the set maximum water pressure. 
     An upper protrusion  181  protruding upward may be on the upper surface of the opening and closing member  180 . The upper protrusion  181  may have a set length and may be in the inner space of the gas supply unit  170  above the cap fastening portion  171 . When the opening and closing member  180  contacts the gas supply unit  170 , the upper end of the upper protrusion  181  may contact with the inner surface of the gas supply unit  170  and elastically deform to a certain level. As a result, the upward movement of the shield unit  180  may be restricted to a certain level. In addition, when the pressure acting on the opening and closing member  180  is removed, the opening and closing member  180  may be prevented from falling off or out of the gas supply unit  170 , and after the supply of the wash water is terminated, the flow path of the gas supply unit  170  is quickly opened so that air may be re-introduced into the inner portion of the dissolving unit  100 . 
     A lower protrusion  183  extending downward may be on the lower surface of the opening and closing member  180 . The lower projection  183  may be in the central region (e.g., the center) of the lower surface of the opening and closing member  180 . A guide groove, hole or depression  165  may be in region of the gas supply unit fastening portion  160  corresponding to the lower projection  183  inside the fastening ribs  161 . The lower projection  183  may prevent the opening and closing member  180  from tilting or leaning. 
     The opening and closing member  180  may have a shape resembling an inverted umbrella. 
     The cap  150  may have support protrusions  166  inside the fastening ribs  161 . The support protrusions  166  may support the bottom surface of the shield unit  181  (for example, the bottom surface of the shield unit  181  along the circumference of the lower protrusion  183 ) when moving downwardly. The support protrusions  166  may be in one or more spaces between adjacent supply holes  162 . For example, when four supply holes  162  are provided, four support protrusions  166  may be in the spaces between the supply holes  162 . The support protrusions  166  may support the bottom surface of the opening and closing member  180  to prevent the opening and closing member  180  from closing the supply hole  162 . 
     The cap connection unit  154  may couple and fix the cap  150  and the dissolving body  110  together. The cap connection unit  154  may be a rib or ring extending downward along the outer circumferential surface at the lower end of the cap  150  and may fit to or mate with the cap fixing unit  112 . 
     In this case, in order to couple and fix the dissolving body  110  and the cap  150  together, the cap connection unit  154  of the cap  150  may be inserted into the cap fixing unit  112  of the dissolving body  110 . The dissolving body  110  and the cap  150  may be sealed while the cap fixing unit  112  and the cap connection unit  154  are fastened. As an example, the cap fixing unit  112  and the cap connection unit  154  may be thermally fused so that the dissolving unit  100  may be sealed. However, the cap fixing unit  112  and the cap connection unit  154  are not limited to a rib or ring shape, but may comprise a flange or the like. 
     Next, the nozzle unit  200  may generate micro-bubbles by receiving the wash water in which the gas is dissolved or mixed from the dissolving unit  100 . Specifically, the nozzle unit  200  may break the bubbles contained in the wash water supplied from the dissolving unit  100  into micro-bubbles, or increase the amount of bubbles in the wash water to be discharged into the inner basket  22 . 
     The nozzle unit  200  includes a micro-bubble generator  220  configured to generate the micro-bubbles, a gasket  230  and a nozzle portion  240  for discharging the wash water containing micro-bubbles into the inner basket  22 . 
     The nozzle unit  200  may be connected directly to the dissolved water drain portion  111  at one side of the dissolving unit  100 . 
     The dissolved water drain portion (e.g., drain)  111  may be provided such that the flow path formed on the inner side has a set cross-sectional area and a length. Specifically, the dissolved water drain portion  111  may correspond to the size, shape, and cross-sectional area of the micro-bubble generator  220  so that the micro-bubble generator  220  may be inserted into the drain  111 . 
     In the dissolving unit  100 , a nozzle portion connection unit  115  may be on the outside circumference of the dissolving body  110  adjacent or proximate to the dissolved water drain portion  111 . The nozzle portion connection unit  115  may be connected to the body connection unit  248  of the nozzle portion  240  to fix the nozzle portion  240  to the dissolving unit  100 . The nozzle portion connection unit  115  may receive one or more fasteners fastening the nozzle portion  240  to the dissolving body  110 , and the nozzle portion connection units  115  may extend from the outer circumferential surface of the dissolving body  110  on opposite sides (e.g., above and below, left and right, etc.) of the dissolved water drain portion  111 . Each nozzle portion connection unit  115  may include a hole into which a fastening member (e.g., a screw) may be inserted. A total of four nozzle portion connection units  115  may be arranged in a ring, square or rectangular shape on the outer circumferential surface of the dissolving body  110  adjacent or proximate to the dissolved water drain portion  111 . 
     In addition, an auxiliary fixing unit  250  for fixing the nozzle unit  200  to the cabinet  10  may be provided on the outside surface of the nozzle portion  240 . As an example, the auxiliary fixing unit  250  may be flat or planar, or have a plate shape and/or a set area, and the auxiliary fixing unit  250  may have a hole into which a fastening means such as a bolt or a screw is inserted. 
     The micro-bubble generator  220  may be inserted into the dissolved water drain portion  111 . In this case, the dissolved water drain portion  111  may have a shape protruding to a set distance to the outside of the dissolving body  110 , thereby forming an outer dissolution space, and one end of the micro-bubble generator  220  may have a shape suitable for being inserted into the outer dissolution space. The micro-bubble generator  220  includes a housing  222  that can be accommodated in the dissolved water drain portion  111  and decomposition units  224  disposed at set intervals along the circumference of the housing  222  on the inside of the housing  222 . In an embodiment of the disclosure, three decomposition units  224  are in the housing  222 , but not limited to three, and one or more decomposition units  224  may be present. Since the micro-bubble generator  220  may be configured to be inserted into the dissolved water drain portion  111 , the nozzle unit  200  may be coupled to the dissolving unit  200  with a compact shape in which the length protruding to the outside from the dissolving unit  200  is minimized. 
     The decomposition unit  224  may be or comprise a cone (e.g., a tube whose diameter is widened along the traveling direction of the fluid flowing from the outer dissolution space), and may indicate a flow path inside the housing  222 . The micro-bubble generator  220  may include a plurality of decomposition units  224 , and the decomposition units  224  may communicate with the outer dissolution space. In addition, the wash water entering the decomposition unit  224  from the outer dissolution space may pass through the decomposition unit  224  to generate micro-bubbles. In this case, the opening at the side where the wash water is introduced into the decomposition unit  224  may be called the inlet  224   a  of the decomposition unit  224 , and the opening at the side where the wash water is discharged from the decomposition unit  224  may be called the outlet  224   b . The inlet  224   a  and the outlet  224   b  may be centered on one another, and the inlet  224   a  may have a smaller cross-sectional area than the outlet  224   b . Thus, the decomposition unit  224  may be extend from the inlet  224   a  to the outlet  224   b  and have a tapered cross-sectional shape. 
     The wash water in which the gas is dissolved or mixed may contain relatively large bubbles, and such wash water may flow from the outer dissolution space into the inlet  224   a  of the decomposition unit  224  to the outlet  224   b . The wash water flowing into the inlet  224   a  from the outer dissolution space may be introduced at an increased flow rate, as the diameter of the inlet  224   a  communicating with the outer dissolution space is orders of magnitude less than the diameter of the drain  111 . And, the wash water passing through the decomposition unit  224  may gradually expand, and at the same time, the flow rate of the wash water may decrease and the pressure may increase. As a result, the bubbles in the wash water are split to generate micro-bubbles, or new bubbles may be generated in the wash water. In this case, one end of the micro-bubble generator  220  is inserted into the outer dissolution space. The outer dissolution space may have dimensions such that the volume of the region into which the wash water flows into the micro-bubble generator  220  may be smaller than the volume of the adjacent upstream region. Accordingly, the wash water flowing in the direction of the micro-bubble generator  220  may be pressurized before entering the micro-bubble generator  220 . As the pressure increases, the amount of bubble generation in the wash water may increase. Thus, the pressure of the wash water may be increased before being introduced into the micro-bubble generator  220  to supply the wash water to the decomposition units  224 . 
     A gasket  230  may be around the outlet side of the decomposition units  224  of bubble generating portion  220 . The gasket  230  may press at the end of the dissolved water drain portion  111  while surrounding the bubble generating portion  220  at the inside of the nozzle portion  240  when the bubble generating portion  220  is in the nozzle portion  240 . Accordingly, the gasket  230  may be pressurized and fixed by the dissolved water drain portion  111  and the nozzle portion  240 , thereby preventing leakage of micro-bubbles and/or the micro-bubble-containing wash water. The gasket  230  may be or comprise an O-ring, but is not limited thereto. 
     The nozzle portion  240  may be coupled to the dissolved water drain portion  111  so that the bubble generating portion  220  may be accommodated and fixed in place in the dissolved water drain portion  111 , and may serve to discharge the wash water containing micro-bubbles into the inner basket  22 . The nozzle portion  240  may include a first part  240   a  forming a first mixing space  242  and a second part  240   b  connected to the first part  240   a , configured to discharge the wash water containing micro-bubbles toward an upper portion of the inner basket  22 . The first part  240   a  and the second part  240   b  may have blocking surfaces  243  and  245 , which block at least a portion of the flow of wash water from the decomposition units  224  so as not to directly inject the wash water into the inner basket  22 , and may include micro-bubble mixing portions  242  and  244  configured to mix the micro-bubbles generated in the decomposition unit  224  with the washing water that has been discharged from the decomposition unit  224  and slow down the flow of the wash water. 
     Specifically, the first part  240   a  may include a first mixing space  242  communicating with the dissolving unit  224  and having the same cross-sectional area as the cross-sectional area of the housing  222 , and a first blocking surface  243  that alters the flow of the wash water. Similarly, the second part  240   b  may include a second mixing space  244  connected to the first mixing space  242  and having a smaller cross-sectional area than the first mixing space  242 , and a second blocking surface  245  that alters the flow of the wash water flowing in the second mixing space  244 . 
     The first mixing space  242  and the second mixing space  244  may increase the amount of the micro-bubble generation by preventing direct injection of the wash water into the inner basket  22 , while maximizing the flow path of the wash water through the nozzle portion  240 . 
     The first mixing space  242  may have a diameter corresponding to the diameter of the bubble generating portion  220  and a cylindrical shape corresponding to the external shape of the bubble generating portion  220 . The first mixing space  242  is a space where the wash water having the micro-bubbles from the decomposition unit  224  is mixed with wash water that has been previously discharged from the decomposition unit  224  and whose flow rate has slowed down. Specifically, after passing through the decomposition unit  224 , the wash water with a slow flow rate (e.g., that strikes the first blocking surface  243 ) may be discharged to the first mixing space  242 , and some of the wash water with the slow flow rate may stay in the first mixing space  242 . In this case, the wash water continuously injected from the decomposition unit  224  and the wash water staying in the first mixing space  242  may collide and mix, the bubbles in the wash water may be further split, and the micro-bubbles may be more uniformly distributed in the wash water. 
     The second mixing space  244  allows the wash water discharged from the first mixing space  242  to stay for a certain period of time. At this time, additional micro-bubbles may be generated while the wash water in the second mixing space  244  collides with the wash water that is rapidly discharging from the first mixing space  242 . 
     In the embodiment, the second mixing space  244  may have a smaller diameter than the first mixing space  242 , and the first mixing space  242  and the second mixing space  244  may have a step at an interface between them. In this case, one side of the step leading from the first mixing space  242  to the second mixing space  244  may be the first blocking surface  243 . The step may have an edge at a height corresponding to the center line ‘C’ connecting the center of the inlet  224   a  of the decomposition unit  224  and the center of the outlet  224   b.    
     The first blocking surface  243  may extend from the side of the first mixing space  242  and may be parallel to the outlet  224   b  side of the decomposition unit  224 , or be inclined so as to protrude or extend toward the decomposition unit  224 . As an example, the first blocking surface  243  may be a predetermined distance from the outlet of the nozzle portion  240 , and may function as one side forming the first mixing space  242 . In this example, the end of the first blocking surface  243  may be at a height corresponding to 90% to 110% of the distance from the side (e.g., the outermost periphery or outer circumference) of the first mixing space  242  to the extension line of the centerline C of the decomposition unit  224 . The embodiment shown in  FIGS. 4 and 6  is an example in which the end of the first blocking surface  243  is at a height corresponding to the extension line of the center line C of the decomposition unit  224 . As such, the first blocking surface  243  enables simplifying the configuration of the nozzle portion  240 , while blocking the direct injection and discharge of the wash water from the decomposition unit  224  and maximizing the size of the flow path through which the wash water with micro-bubbles therein is supplied. 
     The wash water will slow down in the first mixing space  242 , where the flow path widens from the narrower decomposition units  224 . The first blocking surface  243  may prevent some of the wash water from discharging by direct injection from the decomposition unit  224  to the second mixing space  244 . Therefore, the wash water, part of which is slowed and temporarily retained in the first mixing space  242  by the first blocking surface  243 , may collide with the wash water injected from the dissolving unit  224 , striking the first blocking surface  243  and then entering into the first mixing space  242 , thereby generating additional micro-bubbles. The first blocking surface  243  may be formed at an angle to prevent the direct injection of the wash water discharged from the decomposition unit  224 . By preventing the direct injection, it is possible to allow the micro-bubbles generated in the decomposition unit  224  to spread evenly throughout the wash water and/or to prevent the micro-bubbles from being discharged immediately without being dissolved or suspended in the wash water for a sufficient time. Also, it is possible to generate additional micro-bubbles in the first mixing space  242 . 
     In summary, according to the nozzle unit  200  of an embodiment of the disclosure, when the bubbles introduced from the dissolving unit  100  pass through the expanding decomposition unit  224 , the pressure increases and the flow slows down at the same time. Accordingly, the bubbles may then be split into micro-bubbles, and additional (micro) bubbles may be generated. The slow-flow, micro-bubble-containing water passing through the decomposition unit  224  may be discharged to the first mixing space  242 . In this case, a portion of the micro-bubble-containing water may be relatively slowly discharged from the first mixing space  242  to the second mixing space  244 , and another portion of the micro-bubble-containing water may collide with the first blocking surface  243  to prevent the direct injection. The micro-bubble-containing water colliding with the first blocking surface  243  may not be directly injected into the second mixing space  244 , but may be injected into the first mixing space  242 , so that a collision may occur between the bubbles in the water in the first mixing space  242 , and then the bubbles may be split into micro-bubbles, and the amount of bubbles and/or micro-bubbles may increase. Thus, since the micro-bubbles may collide with the first blocking surface  243  so as not to be fed directly into the second mixing space  244  by direct injection, and additional micro-bubbles may be generated by the first blocking surface  243 , the amount of micro-bubbles may increase. 
     The micro-bubbles in the first mixing space  242  are discharged to the second mixing space  244 . The second mixing space  244  may serve as a guide to direct the micro-bubbles to a discharging position where they are discharged into the inner basket  22 . The second blocking surface  245  may be at a location in the second mixing space  244  near or approaching the discharging position. The micro-bubbles discharged from the first mixing space  242  collide with the second blocking surface  245 , and the direct injection may be prevented once more. The bubbles discharged in the bubble state from the first mixing space  242  may collide with the second blocking surface  245  and may be split into micro-bubbles, which may increase the amount of micro-bubble generation. In addition, since the second blocking surface  245  may be near the discharging position, the micro-bubbles discharged from the second blocking surface  245  may be supplied directly into the inner basket  22 . In addition, the nozzle portion  240  may further include a discharging portion  246  and a body connection unit  248 . 
     The wash water containing the micro-bubbles may be discharged to the washing space in the inner basket  22  through the discharging portion  246 . The discharging portion  246  may have a wider cross-section toward the discharging port, and the second blocking surface  245  may be adjacent to the discharging portion  246 . In addition, the discharging portion  246  may be at a predetermined angle between the second mixing space  244  the inner basket  22  (e.g., with regard to a central axis of the inner basket  22 , a lowermost [horizontal] surface of the inner basket  22 , etc.). The second blocking surface  245  may be at a predetermined angle with regard to the inner basket  22  so as to correspond to the discharging portion  246 . Since the discharging portion  246  is angled and open or directed toward the inner basket  22 , it may prevent scattering of the micro-bubbles discharged to the inner basket  22 . 
     The body connection unit  248  may include a surface extending from one end of the nozzle portion  240  in the vertical direction (e.g., perpendicular to the flow path of water in the nozzle unit  200 ) and may include holes at a position corresponding to the nozzle connection units  115  on the exterior surface of the body portion  110 . Fastening members (e.g., screws, bolts, etc.) may pass through or be inserted into the holes. Thus, the body connection unit  248  is brought into contact with the nozzle connection units  115 , and the fastening members may be inserted into or pass through the holes into the nozzle portion connection units  115  to fasten the dissolving body  110  and the nozzle portion  240 . 
     A leaked water inflow portion  249  may be in or on an upper surface of the nozzle portion  240 . The leaked water inflow portion  249  may have a vertical longitudinal direction. The leaked water inflow portion  249  may be in the second portion  240   b  of the nozzle  240 . Alternatively, the leaked water inflow portion  249  may be in first portion  240   a  of the nozzle  240 , or between the first and second portions  240   a  and  240   b . The leaked water inflow portion  249  may be connected to the gas supply unit  170  by a tube or piping. When the wash water is supplied to the dissolving unit  100  from the water supply line connection unit  151 , water may leak from the gas supply unit  170 . For example, when the wash water is supplied to the dissolving unit ( 100 ), the gas supply unit  170  may be shielded by the opening and closing member  180 . However, at the beginning of the wash water supply, the opening and closing member  180  may not completely shield the gas supply unit  170 , such that water may leak into the gas supply unit  170 . In addition, in the course of use, the opening and closing member  180  may deteriorate or become dirty, the responsiveness of the opening and closing member  180  may deteriorate, and water may leak into the gas supply unit  170  even when the opening and closing member  180  is closed (i.e., shields the gas supply unit  170 ). In this case, the wash water leaking into the gas supply unit  170  may flow into the leaked water inflow portion  249  and be discharged to the inner basket. 
     That is, when the wash water is supplied to the dissolving unit  100 , the flow path of the gas supply unit  170  may be shielded by the opening and closing member  180 , and the wash water may pass through the inner portion of the dissolving unit  100  and the nozzle unit  200  and be discharged to the inner basket  22  after the micro-bubbles are generated. In this case, while the wash water flows, wash water leaking into the gas supply unit  170  may flow into the nozzle unit  200  through the leaked water inflow portion  249  and may be discharged into the inner basket  22  together with the micro-bubbles. And, when the supply of wash water to the dissolving unit  100  stops, the gas may be effectively supplied from two directions (e.g., from the gas supply unit  170  and/or the path in which the micro-bubbles are discharged through the nozzle unit  200  to the inner portion of the dissolving unit  100 ). As described above, the micro-bubble generator according to embodiments of the present disclosure may effectively generate micro-bubbles, even though the dissolving unit  100  and the nozzle unit  200  have a compact structure. In addition, the path through which leaking water may be discharged when the wash water is supplied and the path through which the gas may be supplied when the wash water is not supplied may discharge the leaking water and supply the gas effectively. 
     In an embodiment of the disclosure, the principle of the wash water flowing in, through and/or from the nozzle unit  200  may be summarized below. When the wash water from the dissolving unit  100  passes through the decomposition unit  224 , the bubbles in the wash water may be split into micro-bubbles, and/or additional micro-bubbles may be created. The wash water discharged from the decomposition unit  224  to the first mixing space  242  may be blocked or redirected by a first blocking surface  243  in the first mixing space  242 , and the wash water may stay or reside for a predetermined time in the first mixing space  242  after striking the first blocking surface  243 , such that additional micro-bubbles may generated, and the micro-bubbles may be more uniformly distributed in the wash water. In addition, the micro-bubbles passing through the first mixing space  242  may further collide with the second blocking surface  245  of the second mixing space  244 , thereby preventing direct injection of the micro-bubble-containing wash water into the inner basket  22  and possibly increasing the amount of micro-bubble generation. Therefore, the amount of micro-bubble formation may be increased, to improve the washing power and rinsing power of the wash water. 
     The nozzle unit  200  may enter the inner side of the input hole of the cabinet cover  14  and be located above the inner basket  22 . Accordingly, the micro-bubbles generated in the dissolving unit  100  and the nozzle unit  200  may be supplied into the inner basket  22  where washing is performed without being extinguished. Meanwhile, a pressure regulating unit  300  may be on or in the water supply line L 1 . The pressure regulating unit  300  includes a first body portion  310  connecting the water supply valve unit  32  and the dissolving unit  100  and a second body portion  350  discharging the wash water when the set pressure is applied. 
     The first body portion  310  may be on or in the water supply line L 1  to supply the wash water from the water supply valve unit  32  to the dissolving unit  100 . The first body portion  310  may include a wash water inflow portion  311  and a wash water supply portion  312 . 
     The first body portion  310  may have one or more tubular or cylindrical shapes, and an upper flow path portion  313  and a regulated flow path portion  314  are in an inner central region of the first body portion  310 . The upper flow path portion  313  and the regulated flow path portion  314  may be connected to each other and may be on or along the same central axis. The cross-sectional area of the regulated flow path portion  314  may be larger than the cross-sectional area of the upper flow path portion  313  and may be below the upper flow path portion  313 . 
     The wash water inflow portion  311  may be connected to a front water supply line L 1   a  (which is connected to the water supply valve unit  32 ) and may receive inflowing wash water. The wash water inflow portion  311  may be connected to the upper flow path portion  313 . 
     The wash water supply portion ( 312 ) may communicate with the wash water inflow portion  311 . The wash water supply portion  312  may be connected to the dissolving unit  100  through a rear water supply line L 1   b  to supply the wash water from the wash water inflow portion  311  to the dissolving unit  100 . The wash water supply portion  312  may be connected to the upper flow path. 
     The wash water inflow portion  311  and the wash water supply portion  312  may form flow paths that correspond to each other and may be linear. For example, the wash water inflow portion  311  and the wash water supply portion  312  may comprise a linear pipe or tube, and the central region thereof is connected to the upper flow path portion  313 . 
     The second body portion  350  may be coupled to one side of the first body portion  310  so that when the pressure in the wash water inflow portion  311  and the wash water supply portion  312  equals or exceeds a set or predetermined pressure, the wash water is discharged to reduce the pressure. The second body portion  350  may have a tubular or cylindrical shape having a flow path connected to the upper flow path portion  313  and the regulated flow path portion  314  in the inner central region. The second body portion  350  may include an accommodating portion  351 , a lower flow path portion  352  and an auxiliary drain  355 . 
     The accommodating portion  351  may be coupled with the first body portion  310  and/or receive the lower portion of the first body portion  310 . For example, the inner surface of the accommodating portion  351  may have a shape corresponding to the lower outside surface of the first body portion  310 . A fixing unit  358  may be inside the accommodating portion  351 . Two or more fixing units  358  may be spaced apart from each other at a set distance along the circumference of the lower flow path portion  352 . 
     The fixing unit  358  may include an insertion path  353   a  and a rotation path  353   b . The insertion path  353   a  may be a groove or opening extending downward along the inner surface of the upper end of the second body portion  350 , and the rotation path  353   b  may be a groove or opening extending a set length along the circumference of the second body portion  350  at the lower end of the insertion path  353   a . The first body portion  310  may couple with the second body portion  350  by rotating after aligning the fixing protrusion  317  on the outside surface of the lower portion with the insertion path  353   a , and then inserting the fixing protrusion  317  by the set length in the direction of the second body portion  350 . In addition, the outer surface of the first body portion  310  and the outer surface of the second body portion  350  may include auxiliary fastening portions  318  and  357  aligned with and/or facing each other. One of the auxiliary fastening portions  318  and  357  may comprise a hole and the other may comprise a groove or hole with a set depth. The auxiliary fastening portion  318  may be fastened to the auxiliary fastening portion  357  by a fastening means such as a bolt, screw or the like. 
     The lower flow path portion  352  may be between the auxiliary drain  355  and the accommodating portion  351  so that the regulated flow path portion  314  and the auxiliary drain  355  are connected to each other. The cross-sectional area of the lower flow path portion  352  may be less than the regulated flow path portion  314  and greater than the auxiliary drain. The lower end of the first body portion  310  and the bottom surface of the inside of the accommodating portion  351  are spaced apart from each other by a set distance, and a gasket  320  may be between the bottom surface of the inside of the accommodating portion  351  and the lower end of the first body portion  310 . 
     A guide  358  may be in the lower flow path portion  352 . The guide  358  may comprise a rib or tongue that may be longitudinally oriented the vertical direction. A plurality of guides  358  may be a set distance apart along the circumference of the lower flow path portion  352 . An upper end portion of the guide  358  may protrude and/or incline toward the inside of the lower flow path portion  352  from the upper side to the lower side. 
     An elevating member or valve  330  may be inside the first body portion  310  and the second body portion  350 . The elevating member  330  may include a plate in the regulated flow path portion  314  that is larger (i.e., has a larger diameter) than the cross-sectional area of the upper flow path portion  313  and the lower flow path portion  352 , but smaller than the cross-sectional area of the regulated flow path portion  314 . An elastic member or spring  340  may be between the elevating member  330  and a lowermost inner surface of the second body portion  350 . The upper end of the elastic member  340  may contact the elevating member  330 , and the lower end of the elastic member  340  may contact a step formed between the lower flow path portion  352  and the auxiliary drain  355 . The upper surface of the elevating member  330  may have an upper guide  331  extending in the direction of the upper flow path portion  313  and having a cross-sectional area or width smaller than the cross-sectional area of the upper flow path portion  313 . The upper end portion of the upper guide  331  may be inclined so as to protrude upward in the downward direction. The elevating member  330  may move up and down in alignment with the upper flow path portion  313  by the upper guide  331  in the upper flow path portion  313 . 
     In addition, the lower surface of the elevating member  330  may have a lower guide  332  extending in the direction of the lower flow path portion  352  and inside the elastic member  340 . The cross-sectional area of the lower guide  332  may be smaller than the cross-sectional area of the lower flow path portion  352  and the diameter of the elastic member  340 . The lower end of the lower guide  332  may be tapered or pointed (e.g., inclined toward the center as it goes downward). The lower guide  332  enables the elevating member  330  to move up and down in alignment with the lower flow path portion  352 . 
     So that the gas may be effectively dissolved or mixed into the wash water in the dissolving unit  100 , the wash water supplied to the dissolving unit  100  should have a set pressure or be within a predetermined range of pressures. If the pressure of the wash water supplied to the dissolving unit  100  is lower than the set pressure or minimum predetermined pressure, the gas will not effectively dissolve in or mix with the wash water. On the other hand, if the pressure of the wash water supplied to the dissolving unit  100  becomes too high or exceeds the maximum predetermined pressure, the water supply line may be damaged by the pressure of the wash water. 
     In order to prevent wash water from entering the micro-bubble generator with excessively high pressure, one may include a decompression packing at the outlet of the water supply valve unit  32 . However, in this case, since the total water pressure entering the micro-bubble generator is relatively low, the micro-bubble generator may not operate when the water pressure is low. 
     According to the present disclosure, the pressure regulating unit  300  may be set such that the pressure in or applied to the water supply line (e.g., by the elastic member  340 , which may have a predetermined elastic modulus) may be controlled to a set pressure or a pressure within a set range. When the pressure of the water supply line L 1  equals or exceeds the set pressure, a force applied to or on the elevating member  330  by wash water in the upper flow path portion  313  may be greater than the force applied to the elevating member  330  by the elastic member  340 , and thus, the elevating member  330  may move downward. Thus, the upper flow path portion  313  may be connected to the regulated flow path portion  314  so that the wash water of the water supply line L 1  may discharge through the auxiliary drain  355 , and the water supply line L 1  may be prevented from being broken by excessive pressure. In this case, the distance that the elevating member  330  moves downwardly may be limited by the distance that the elastic member  340  is elastically deformable. In addition, the oblique shape of the upper end of the guide  358  prevents impedance of the elastic deformation of the elastic member  340  when the elastic member  340  moves downwardly. 
     The wash water discharged to the auxiliary drain  355  may flow into the inner basket  22  (or the outer basket  20 ). As an example, the auxiliary drain  355  may be above the inner basket  22  and/or the flow direction of the wash water may be directed toward the inner basket  22  (e.g., using a separate nozzle). Further, an adjustment line or tube (not shown) may be connected to the auxiliary drain  355 , and the end of the adjustment line or tube may be positioned above the inner basket  22  so that the discharged wash water may flow into the inner basket  22 . Depending on the embodiment, the auxiliary drain  355  may be connected to the leaked water discharge line L 2  or the nozzle portion  240 . 
     When the pressure of the water supply line L 1  returns to the set pressure or to a pressure within the set range, the elastic member  340  may lift or force the elevating member  330  back to a default (e.g., closed) position that shields the upper flow path portion  313  and the regulated flow path portion  314 . 
     Hereinafter, the operation and effect of the washing machine  1  and the micro-bubble generator BG, and a method of supplying wash water including micro-bubbles according to one or more embodiments of the disclosure, will be described. 
     First, the wash water may be supplied from an external water supply source via a water supply valve unit  32 . Next, the gas may be dissolved or mixed in the wash water in the dissolving unit  100 . 
     Herein, in order to dissolve or mix the gas in the wash water in the dissolving unit  100 , the wash water may be supplied through the water supply line connection unit  151  of the cap  150  in the horizontal direction from the water supply valve unit  32  above the dissolving unit  100 , and the horizontal flow direction of the wash water in the cap  150  may change to the vertical direction by the water supply direction switching portion  152  of the cap  150 . The wash water may be relatively uniformly discharged by the water supply direction switching portion  152 , and may fill the partition wall  120  and then overflow. The wash water overflowing from the partition wall  120  may enter the space between the partition wall  120  and the dissolving body  110  to allow the gas to dissolve or mix in the wash water. 
     By this process, the wash water in which the gas is dissolved or mixed is supplied from the dissolving unit  100  to the nozzle unit  200 , and the nozzle unit  200  may form micro-bubbles by splitting the bubbles in the wash water. 
     The bubbles formed by dissolving or mixing the gas in the wash water in the dissolving unit  100  may enter the inlet  224   a , where the flow rate may increase. Subsequently, the bubbles in the water with the increased flow rate pass through the outlet  224   b  of the decomposition unit  224 . Since the flow slows down and the pressure increases while passing through the decomposition unit  224 , the bubbles may be split into micro-bubbles. A portion of the micro-bubbles discharged from the decomposition unit  224  may be indirectly injected into the first mixing space  242  by contacting the first blocking surface  243  in the nozzle portion  240 , and the amount of micro-bubble generation may increase during the collisions between the bubbles. The wash water discharged from the first mixing space  242  may pass through the second mixing space  244 , may be prevented again from being directly injected (e.g., to the inner basket  22 ) by the second blocking surface  245 , and may then be discharged through a discharging portion  246 , during which the amount of micro-bubble generation may increase. In the course of the above processes, the discharged micro-bubbles may flow into the inner basket  22  by the aid of the inner surface of the discharging portion  246  and/or the second blocking surface  245 . Thus, the nozzle unit  200  may discharge the wash water containing the micro-bubbles into the inner basket  22 , where the laundry is accommodated. 
     During the operation of the micro-bubble generating unit, some wash water may remain inside the micro-bubble generating unit. In order to discharge the wash water remaining in the micro-bubble generating unit (hereafter, residual wash water), a hole in the micro-bubble generating unit may discharge the residual wash water, and hole may be connected to the main drain valve or a separate valve structure on a path through which the residual wash water is discharged. However, when the micro-bubble generating unit is constructed as described above, there is a problem that it is difficult to generate the micro-bubbles by supplying the wash water to the micro-bubble generating unit before discharging the residual wash water from the micro-bubble generating unit. Accordingly, there is a problem that it is difficult to use the micro-bubble generating unit in a plurality of washing processes. Thus, if the valve discharges the residual wash water in one washing process, the user may mistakenly think that the wash water in the outer basket has been drained due to the sound generated during the residual wash water discharge process. 
     In contrast, according to one embodiment of the present disclosure, the washing machine may be configured such that the wash water remaining in the dissolving unit  100  may be minimized, and the residual wash water may be drained without operating a separate valve. Accordingly, the micro-bubbles may be supplied by operating the dissolving unit  100  a plurality of times without concern for the user even in a single washing process. In addition, the nozzle unit  200  and the dissolving unit  100  may have a compact integral-type structure. Thus, the micro-bubble generator may be installed above the inner basket  22  without restriction of the installation space, and micro-bubble-containing water may be supplied to the laundry immediately after the micro-bubbles are generated. 
       FIG. 11  is a view showing a configuration of a micro-bubble generator according to another embodiment, and  FIG. 12  is a cross-sectional view of a pressure regulating unit taken along a line D-D in  FIG. 11 . 
     Referring to  FIGS. 11 and 12 , the micro-bubble generator may include a dissolving unit  100 ′ and a nozzle unit  200 ′. The construction and operation of the dissolving unit  100 ′ and the nozzle unit  200 ′ may be the same as or similar to the dissolving unit  100  and the nozzle unit  200  of  FIGS. 3 to 7 , and thus the repeated explanations are omitted. 
     The dissolving unit  100 ′ may be connected to the water supply valve unit  32  through the water supply line L 1 ′, similarly to the micro-bubble generator of  FIG. 2 , so that the micro-bubbles may be generated by receiving the wash water and supplied to the laundry. 
     The water supply line L 1 ′ may include a front water supply line L 1   a ′, a rear water supply line L 1   b ′ and a branch line L 1   c ′. One side or end of the front water supply line L 1   a ′ may be connected to the water supply valve unit  32 . The rear water supply line L 1   b ′ may connect the dissolving unit  100 ′ to the other side or end of the front water supply line L 1   a ′. The branch line L 1   c ′ may be branched at the point where the front water supply line L 1   a ′ and the rear water supply line L 1   b ′ are connected, and the branch line L 1   c ′ may be connected to the detergent container accommodating portion  15 . 
     A pressure regulating unit  300 ′ may be at the point where the branch line L 1   c ′ and the detergent container accommodating portion  15  are connected. 
     The pressure regulating unit  300 ′ may include a first body portion  310 ′ and a second body portion  350 ′. A wash water inflow portion  311 ′ connected to the branch line L 1   c ′ may be at one side of the first body portion  310 ′. 
     An elevating member or valve  330 ′ and an elastic member or spring  340 ′ may be in the space inside the first body portion  310 ′ and the second body portion  350 ′ so that when the pressure of the water supply line L 1 ′ exceeds the set pressure, the pressure regulating unit  300 ′ allows the wash water to be discharged to the inside of the detergent container accommodating portion  15 . Thus, it is possible to allow the pressure inside the water supply line L 1 ′ to maintain the set pressure or a pressure within a set range. Some of the components of the pressure regulating unit  300 ′ may be integral with the detergent container accommodating portion  15 , or be fixedly inserted in a hole in the detergent container accommodating portion  15 , so that the pressure regulating unit  300 ′ may be on one side of the accommodating portion  15 .  FIGS. 11 and 12  illustrate that, as an example, the second body portion  350 ′ may be integral with a detergent container accommodating portion  15 . The configuration and operation of the pressure regulating unit  300 ′ is the same as or similar to that of the pressure regulating unit  300  of  FIGS. 8 to 10 , except that the wash water supply portion  312  in the pressure regulating unit  300  of  FIGS. 8 to 10  is omitted, so repeated descriptions are omitted. 
       FIG. 13  is a view showing a schematic configuration of a washing machine according to another embodiment. 
     Referring to  FIG. 13 , according to another embodiment of the present disclosure, a washing machine  1 ′ may include a cabinet  10 ′, a tub  20 ′, and a drum  22 ′ as a front loading-type washing machine. 
     The cabinet  10 ′ provides the overall appearance of the washing machine  1 ′ and may function as an external case. The cabinet  10 ′ may protect various components of the washing machine  1 ′ that may have, among other things, a heat radiation structure. The space in the cabinet  10 ′ may include the components of the washing machine  1 ′. 
     A door  16 ′ may be on one side of the cabinet  10 ′. The door  16 ′ may shield (e.g., close) or open one side of the cabinet  10 ′ for loading or unloading the laundry. When the user loads the laundry to be washed into the washing machine  1 ′, or unloads the completely washed laundry from the washing machine  1 ′, the user may open the door  16 ′ to load or unload the laundry into or from the washing machine  1 ′. In addition, when the washing process is performed, the user may cover the opening into the washing machine  1 ′ with the door  16 ′. 
     A tub  20 ′ may be inside the cabinet  10 ′. The tub  20 ′ may have a cylindrical structure capable of receiving the wash water and may be tilted relative to a vertical plane so that an open end of the tub  20 ′ may face the door  16 ′ in the front of the cabinet  10 ′. 
     The tub  20 ′ may be supplied with detergent from the detergent container and may receive the wash water from the water supply valve unit  32 ′. 
     A drum  22 ′ may be inside the tub  20 ′. The drum  22 ′ may be rotated in the tub  20 ′ by the motor  28 ′. A washing space  31  for washing the laundry may be inside the drum  22 ′. The laundry may be washed by the wash water and detergent supplied in the tub  20 ′ and may move in conjunction with the drum  22 ′ during the rotation of the drum  22 ′. 
     The main drain valve  36 ′ may be at the bottom of the tub  20 ′ and may control drainage of the wash water in the tub  20 ′. Specifically, the main drain valve  36 ′ may communicate with the lower portion of the tub  20 ′, and a main drain hose  34 ′ may be connected to the main drain valve  36 ′. 
     According to the present embodiment, the tub  20 ′ and the drum  22 ′ may correspond to the outer basket  20  and the inner basket  22  of the washing machine of  FIG. 1 , respectively, in terms of accommodating the wash water and the laundry. Therefore, the tub  20 ′ and the drum  22 ′ according to the present embodiment may be referred to as an outer basket  20 ′ and an inner basket  22 ′, respectively, in order to correspond to the name. 
     A door gasket  50  may be between the cabinet  10 ′ and the tub  20 ′ in the region of the door  16 ′. The door gasket  50  may have a generally cylindrical shape so that one open side may face the cabinet  10 ′ where the door  16 ′ is located and the other open side may face the tub  20 ′. 
     The door gasket  50  may comprise a soft material such as rubber, silicone, and the like, and may have a stretchable or pliable structure. Opposing sides or surfaces of the door gasket  50  may be in contact with the cabinet  10 ′ and the tub  20 ′ to prevent the wash water from leaking between the cabinet  10 ′ and the tub  20 ′. 
     In addition, the washing machine  1 ′ may include a control unit  40 ′ and an operation unit  42 ′. The operation unit  42 ′ may be on the outside upper portion of the cabinet  10 ′. 
       FIG. 14  is a view showing a configuration of an exemplary micro-bubble generator connected to a door gasket,  FIG. 15  is a perspective view of an exemplary nozzle unit,  FIG. 16  is an exploded perspective view of the nozzle unit of  FIG. 15 , and  FIG. 17  is a sectional view of the nozzle unit of  FIG. 15  taken along the line E-E. 
     According to another embodiment of this disclosure, the micro-bubble generator may include a dissolving unit  100 ″ and a nozzle unit  400 . 
     The micro-bubble generator may be in the upper inside portion of the washing machine  1 ′. 
     The dissolving unit  100 ″ may be connected to the water supply valve unit  32 ′ through a water supply line L 1 ″. The dissolving unit  100 ″ may be connected to the nozzle unit  400  through a supply line L 3 , and the wash water discharged from the dissolving unit  100 ″ may flow into the nozzle unit  400 . The water leaking from the dissolving unit  100 ″ may be discharged through the leaked water discharge line L 2 ″ and the nozzle unit  400  into the tub  20 ′. The nozzle unit  400  may be connected to the drain  111 ″ of the dissolving unit  100 ″ through the supply line L 3 , and the flow path inside the drain  111 ″ may be the same as or similar to that of  FIGS. 2 to 7 , except that the flow path may be smaller than that inside the drain  111  of the dissolving unit  100  of  FIGS. 2 to 7 , so repeated descriptions are omitted. 
     Further, a pressure regulating unit  300 ″ may be on or in the water supply line L 1 ″. The pressure regulating unit  300 ″ also includes a path through which the wash water flows into the tub  20 ′, without passing through the dissolving unit  100 ″, through an adjustment line L 4 . When the water supply line L 1 ″ reaches a set or predetermined pressure, the wash water is discharged from the pressure regulating unit  300 ″ towards the adjustment line L 4 . The adjustment line L 4  may be connected to the door gasket  50 . The construction and operation of the pressure regulating unit  300 ″ may be the same as or similar to the pressure regulating unit  300  of  FIGS. 2 to 8 , and thus the repeated descriptions are omitted. 
     The nozzle unit  400  may generate the micro-bubbles by receiving the wash water in which gas is dissolved or mixed from the dissolving unit  100 . Specifically, the nozzle unit  400  may split or increase the bubbles in the water from the dissolving unit  100 ″ and then discharge the micro-bubble-containing water to the inner basket  22 ′. The nozzle unit  400  may be fixed to and/or inserted into a hole in the door gasket  50 . The hole to which the nozzle unit  400  is fixed or inserted may be in the upper portion and/or region of the door gasket  50 . 
     The nozzle unit  400  may include a body portion  410  connected to the dissolving unit  100 ″, a micro-bubble generator  420  configured to generate micro-bubbles, a gasket  430  and a nozzle portion  440  for discharging the wash water containing micro-bubbles to the inner basket  22 ′. 
     The body portion  410  may include a dissolving unit connection unit  412 , and the dissolving unit connection unit  412  may be connected to the supply line L 3  to receive the water in which the gas is dissolved or mixed from the dissolving unit  100 ″. 
     The body portion  410  may be supplied with the wash water in which the gas is dissolved or mixed, and the wash water may be pressurized inside the body portion  410 . This body portion  410  may include the dissolving unit connection unit  412 , a micro-bubble generator accommodating portion  414 , a pressurizing space  415  and nozzle portion connection units  418 . 
     The dissolving unit connection unit  412  may be connected to the supply line L 3  to supply the wash water in which the gas is dissolved or mixed from the dissolving unit  100 ″ into the nozzle unit  400 . 
     The micro-bubble generator accommodating portion  414  may be connected to the pressurizing space  415  to receive the micro-bubble generator  420 . The micro-bubble generator accommodating portion  414  may communicate with the dissolving unit connection unit  412  and may extend or protrude toward the nozzle portion  440 . The micro-bubble generator accommodating portion  414  may have a diameter that is larger than the dissolving unit connection unit  412 . Specifically, the micro-bubble generator accommodating portion  414  may correspond to or have a size and shape accommodating the size, shape, and cross-sectional area of the micro-bubble generator  420  so that the micro-bubble generator  420  may be inserted therein. However, the micro-bubble generator accommodating portion  414  may be longer than the micro-bubble generator  420 , and after the micro-bubble generator  420  is inserted, the pressurizing space  415  may be formed between the dissolving unit connection unit  412  and the micro-bubble generator  420 . 
     The micro-bubble generator accommodating portion  414  may include a step a predetermined distance from one end of the micro-bubble generator accommodating portion  414  (e.g., connected to the dissolving unit connection unit  412 ), which may form the pressurizing space  415  by separating the micro-bubble generator  420  from the one end connected to the dissolving unit connection unit  412  by the predetermined distance. By engaging the micro-bubble generator  420  with the step, when the micro-bubble generator  420  is inserted into the micro-bubble generator accommodating portion  414 , it may be spaced a predetermined distance apart from the dissolving unit connection unit  412 . The pressurizing space  415  may be the space between the end of the dissolving unit connection unit  412  and the micro-bubble generator  420 . 
     The dissolving unit connection unit  412  may be connected to one end of the pressurizing space  415 , and the wash water containing the bubbles may be introduced into the pressurizing space  415 . The pressurizing space  415  may be supplied with the wash water in which the gas is dissolved or mixed from the dissolving unit  100 ″, and the wash water may be pressurized within the pressurizing space  415 . Specifically, the wash water in which the gas is dissolved or mixed may pass through the supply line L 3  with a narrow flow path, enter the pressurizing space  415  having a cross-sectional area wider than the supply line L 3 , and be pressurized before passing through the micro-bubble generator  420  having a cross-sectional area smaller than the cross-sectional area of the pressurizing space  415 . As the pressure increases, the amount of bubble generation in the wash water may increase. Therefore, water containing bubbles may be supplied to the decomposition unit  424  by increasing the pressure of the wash water in which the gas is dissolved or mixed in the pressurizing space  415 . 
     The nozzle portion connection units  418  may be at the circumference of the micro-bubble generator accommodating portion  414  and may be connected to the body connection unit  448  of the nozzle portion  440  to fix the body portion  410  to the nozzle portion  440  or vice versa. The nozzle portion connection units  418  may fasten the body portion  410  and the nozzle portion  440 , and may extend from opposite sides of the micro-bubble generator accommodating portion  414 . Each nozzle portion connection unit  418  may include a hole into or through which a fastening member may be inserted. A total of four nozzle portion connection units  418  may form a square or rectangle around the outer circumferential surface of the micro-bubble generator accommodating portion  414 . 
     The micro-bubble generator  420  may be inserted into the micro-bubble generator accommodating portion  414  on one side of the pressurizing space  415 . The micro-bubble generator  420  may include a housing  422  accommodatable in the body portion  410 , and a plurality of decomposition units  424  at predetermined intervals inside the housing  422  along a circumference of the housing  422 . In an embodiment of the present disclosure, three decomposition units  424  are in the housing  422 . However, the present disclosure is not limited to three decomposition units, and may include one or more decomposition units  424 . 
     The decomposition unit  424  may be or comprise a cone or a tube whose diameter widens along the direction of the fluid flow from the pressurizing space  415 , indicating the flow path within the housing  422 . A plurality of decomposition units  424  may be in the housing  422 , and the decomposition unit(s)  424  may communicate with the pressurizing space  415 . The wash water entering the decomposition unit  424  from the pressurizing space  415  may pass through the decomposition unit  424  to generate micro-bubbles. In this case, the opening at the side where the wash water is introduced into the decomposition unit  424  may be referred to as the inlet  424   a  of the decomposition unit  424 , and the opening at the side where the wash water is discharged from the decomposition unit  424  may be referred to as the outlet  424   b . The inlet  424   a  and the outlet  424   b  are centered on one another (e.g., may have a common linear axis), and the inlet  424   a  may have a smaller cross-sectional area than the outlet  424   b . Thus, the decomposition unit  424  may extend from the inlet  424   a  to the outlet  424   b  and have a tapered cross-sectional shape along the flow path therein. 
     The wash water in which the gas is dissolved or mixed may contain relatively large bubbles, and the wash water may be introduced from the pressurizing space into the inlet  424   a  of the decomposition unit  424  and discharged from the outlet  424   b . The diameter of the inlet  424   a  communicating with the pressurizing space  415  may be much less than the diameter of the pressurizing space  615 , and at the same time, the wash water may flow into and/or through the inlet  424   a  from the pressurizing space  415  at an increased rate. The wash water may gradually expand as it passes through the decomposition unit  424 , and the flow rate of the wash water may decrease and the pressure may increase at the same time. Thus, the bubbles contained in the wash water may be split to generate micro-bubbles, or new bubbles may be generated in the wash water. 
     The gasket  430  may be at the circumference of the outlet side of the decomposition unit  424  of the micro-bubble generator  420 . The gasket  430  may surround the micro-bubble generator  420  inside the nozzle portion  440  and press the end of the body portion  410  when the micro-bubble generator  420  is inserted into the nozzle portion  440 . Thus, the gasket  430  is pressurized and fixed by the body portion  410  and the nozzle portion  440 , thereby preventing leakage of water containing micro-bubbles from the nozzle unit  400 . The gasket  430  may comprise an o-ring, but is not limited thereto. 
     The nozzle portion  440  may be coupled to the body portion  410  so that the micro-bubble generator  420  may be fixed inside the body portion  410  to discharge the micro-bubble-containing water to the inner basket  22 . The first portion  440   a  may include a first mixing space  442 , and the second portion  440   b  connected to the first portion  440   a  may discharge the wash water in which micro-bubbles are dissolved or mixed into the upper portion of the inner basket  22 . The first portion  440   a  and the second portion  440   b  may include blocking portions  443  and  445  to prevent at least a portion of the wash water discharged from each decomposition unit  424  from being directly injected (e.g., into the inner basket  22 ), and micro-bubble mixing units  442  and  444  configured to mix micro-bubbles from the micro-bubble generating unit  424  with wash water having a slow flow after being discharged from the decomposition unit  424 . 
     Specifically, the first part  440   a  may include a first mixing space  442  communicating with the decomposition unit  424  and having the same cross-sectional area as the cross-sectional area of the housing  422 , and a first blocking surface  443  that alters the flow of the wash water in the first mixing space  442 . In addition, the second portion  440   b  may include a second mixing space  444  connected to the first mixing space  442  and having a smaller cross-sectional area than the first mixing space  442 , and a second blocking surface  445  that alters the flow of the wash water in the second mixing space  444 . 
     As such, the first mixing space  442  and the second mixing space  444  may increase the amount of micro-bubble generation by preventing direct spraying or injection, while maximizing the flow path. 
     The first mixing space  442  may be a cylinder or tube having a shape corresponding to the cross-sectional shape of the micro-bubble generator  420 , and may have a diameter corresponding (e.g., equal) to the diameter of the micro-bubble generator  420 . The first mixing space  442  may be a space in which wash water having a slow flow after being discharged from the decomposition unit  424  is mixed with micro-bubble-containing water discharged from the decomposition unit  424 . Specifically, after passing through the decomposition unit  424 , the wash water with the slow flow may be discharged into the first mixing space  442 , and some of the wash water with the slow flow may stay or reside in the first mixing space  442 . In this case, the wash water continuously injected from the decomposition unit  424  and the wash water staying in the first mixing space  442  may collide and mix, the bubbles in the wash water may be further split, and the micro-bubbles may be more uniformly distributed in the wash water. 
     The second mixing space  444  allows the wash water discharged from the first mixing space  442  to stay for a certain time, and the wash water rapidly discharged from the first mixing space  442  may collided with the wash water staying or residing in the second mixing space  444 , so that additional micro-bubbles may be generated. 
     Herein, the second mixing space  444  may have a smaller diameter than the first mixing space  442 , and the first mixing space  442  and the second mixing space  444  may have a step. In this case, the step leading from the first mixing space  442  to the second mixing space  444  may be the first blocking surface  443 . In this case, the step may have a height corresponding to the center line C connecting the center of the inlet  424   a  of the decomposition unit  424  and the center of the outlet  424   b.    
     The first blocking surface  443  may extend from the side of the first mixing space  442  and have a shape or surface that is parallel to the surface of the outlet  424   b  of the decomposition unit  424  or that is inclined or protruding toward the decomposition unit  424 . In one example, the first blocking surface  443  may be at a predetermined distance from the outlet  424   b  of the decomposition unit  424  or the outlet of the nozzle portion  440 , and may form one side or edge of the first mixing space  442 . In this case, the end or inner edge of the first blocking surface  443  may be at a height corresponding to 90% to 110% of the distance from the side surface of the first mixing space  442  to the extension of the center line C of the decomposition unit  424 . In this embodiment, the end of the first blocking surface  443  is at a height corresponding to the extension of the center line C of the decomposition unit  424 , as an example. By forming the first blocking surface  443 , the wash water may be prevented from being directly injected from the decomposition unit  424  and then discharged immediately, and the configuration of the nozzle portion  440  may be simplified while maximizing the size of the flow path through which the wash water is supplied. 
     The wash water may be slowed by running from the decomposition unit ( 424 ) with a narrow flow path to the first mixing space  442  where the flow path is widened. In this case, the first blocking surface  443  may prevent the flow of the slow wash water from being discharged by being directly injected from the decomposition unit  424  to the first mixing space  442  and the second mixing space  444 . Thus, the flow may be slowed in the first mixing space  442  by the first blocking surface  443  and may be injected in the temporarily stayed water and the decomposition unit  424  so that the wash water may be collided with the first blocking surface  443  and the wash water again injected to the first mixing space to generate micro-bubbles. The first blocking surface  443  may be formed at an angle such that it is not formed obliquely to the running direction to prevent the wash water discharged from the decomposition unit  424  from being injected directly. By preventing the direct injection, it is possible to prevent the micro-bubble generated in the decomposition unit  424  from spreading evenly in the wash water or to prevent the micro-bubble being discharged immediately without a sufficient time to be dissolved or mixed, and additional micro-bubbles may be generated in the first mixing space  442 . 
     In summary, according to an embodiment of the present disclosure, in the nozzle unit  400 , the bubbles introduced from the dissolving unit  100 ″ may pass through the outlet  424   b  of the decomposition unit  424 , and the flow of the water in the decomposition unit  424  may slow and the pressure of the water in the decomposition unit  424  may increase at the same time. Thus, the bubbles may be split into micro-bubbles, and additional bubbles may be created. The micro-bubble-containing water with the slow flow passing through the decomposition unit  424  may be discharged to the first mixing space  442 , and some of the micro-bubble-containing water may be discharged to the second mixing space  444 , optionally slowly from the first mixing space  442 . Some of the micro-bubble-containing water may collide with the first blocking space  443 . Thus, it is possible to prevent direct injection (e.g., of the micro-bubble-containing water to the second mixing space  444  and/or the inner basket  22 ). The micro-bubble-containing water impinging on the first blocking surface  443  may be not directly injected into the second mixing space  444 , but may be injected into the first mixing space  442  so that a collision between bubbles in the water may occur in the first mixing space  442 . Such collisions may split the bubbles into micro-bubbles, and the amount of bubble generation may increase. Thus, since the micro-bubbles may strike the first blocking surface  443  and may be not fed directly into the second mixing space  444  by direct injection, but additional micro-bubbles may be generated by the first blocking surface  443 , thereby increasing the amount of micro-bubbles. 
     The micro-bubbles generated in the first mixing space  442  may be discharged to the second mixing space  444 . The second mixing space  444  may serve as a guide to guide the micro-bubble-containing water to a discharge position where the micro-bubble-containing water is discharged into the inner basket  22 . A second blocking surface  445  may be at a portion of the second mixing space  444 , guiding the water to the discharge position. The micro-bubble-containing water discharged from the first mixing space  442  may collide with the second blocking surface  445 , and direct injection (e.g., of the micro-bubble-containing water into the inner basket  22 ) may be prevented once more. The bubbles discharged from the first mixing space  442  may collide with the second blocking surface  445  and may be split into micro-bubbles to increase the amount of micro-bubbles generated. In addition, since the second blocking surface  445  may be at the discharge position, the micro-bubbles discharged after colliding with the second blocking surface  445  may be supplied directly into the inner basket  22 . In addition, the nozzle portion  440  may further include a discharge portion  446  and a body connection unit  448 . 
     The wash water in which the micro-bubbles are dissolved or mixed through the discharge part  446  may be discharged into the washing space. The discharge portion  446  may face the inner basket  22 ′. The inner surface of the discharge portion  446  may be or comprise a second blocking surface  445 . In addition, the discharge portion  446  may have a predetermined angle relative to the second mixing space  444  (or a central axis thereof) toward the inner basket  22  so as to be directed toward the inner basket  22 . The second blocking surface  445  may have an inclination at a predetermined angle in the direction of the inner basket  22  so as to correspond thereto. Since the discharge part  446  may be inclined toward the inner basket  22 , it is possible to prevent scattering of the discharged micro-bubbles. 
     The body connection unit  448  may include a surface extending from one end of the nozzle portion  440  orthogonal to the vertical direction of the flow path in the nozzle unit  400  and include holes at positions corresponding to the nozzle connection units  418  of the body portion  410 . A fastening member may be inserted into the hole. Thus, the body connection unit  448  may be brought into contact with the nozzle connection units  418  of the body portion  410  and a fastening member such as a bolt or screw may be inserted through the body connection unit  448  and into the nozzle connection units  418  to fasten the body portion  410  to the nozzle portion  440 . 
     A leaked water inflow portion  450  may be at one side of the discharge portion  446  to provide a path through which the wash water leaking from the gas supply unit  170  is discharged to the inner basket. The leaked water inflow portion  450  may comprise a pipe or tube with a set length and may be at one side of the nozzle unit  400 . As an example, the leaked water inflow portion  450  may be in the nozzle portion  440 , through the body connection unit  448 . In addition, the leaked water inflow portion  450  may be on one side of the body portion  410  and/or the nozzle portion  440 . 
     According to an embodiment of the present disclosure, in summary of the flow principle of the wash water in the nozzle unit  400 , the wash water flowing through the dissolving unit connection unit  412  may enter into the pressurizing space  415  and be pressurized while staying or residing therein for a predetermined time, Thereafter, when the wash water from the pressurizing space  415  passes through the decomposition unit  424 , the bubbles in the wash water may be split into micro-bubbles, and/or additional micro-bubbles may be generated. At least part of the wash water discharged from the decomposition unit  424  to the first mixing space  442  may collide with or be blocked by the first blocking surface  443  in the first mixing space  442 , and may stay for a certain time in the first mixing space  442 , whereby additional micro-bubbles may be generated and/or the micro-bubbles may be more uniformly distributed in the wash water. In addition, the micro-bubble-containing water passing through the first mixing space  442  may strike the second blocking surface  445  in the second mixing space  444  to prevent the direct injection of the micro-bubble-containing water (e.g., into the inner basket  22 ) and increase micro-bubble generation. Therefore, it is possible to increase washing power and rinsing power by increasing micro-bubble production. 
       FIG. 18  is a block diagram showing a path to which wash water is supplied. 
     Referring to  FIG. 18 , two or more flow paths for supplying the wash water from the water supply valve unit  32 ,  32 ′ to the outer baskets  20 ,  20 ′ and the inner basket  22 ,  22 ′ may be provided. In this case, one of the flow paths supplying the wash water may be a path through which the wash water containing micro-bubbles is supplied via the dissolving unit  100 ,  100 ′, and the other of the flow paths may be a path that does not pass through the dissolving unit  100 ,  100 ′ and through which wash water not containing micro-bubbles passes. The water supply valve unit  32 ,  32 ′ may be configured to include a first water supply valve  510  configured to turn on and/or off the supply of the wash water into the flow path via the dissolving unit  100 ,  100 ′ and a second water supply valve  520  configured to turn on and/or off the supply of the wash water into the flow path that does not pass through the dissolving unit  100 ,  100 ′. Also, a water level sensor  530  may be in the outer basket  20 ,  20 ′ or the inner basket  22 ,  22 ′ where the wash water is received. As an example, the water level sensor  530  may detect the amount of wash water (e.g., in the outer basket  20 ,  20 ′ or the inner basket  22 ,  22 ′) by changes in the frequency of vibrations occurring in the outer basket  20 ,  20 ′ or the inner basket  22 ,  22 ′, depending on the amount of wash water in the outer basket  20 ,  20 ′ or the inner basket  22 ,  22 ′. 
       FIG. 19  is a flowchart showing an exemplary process of supplying wash water. 
     Referring to  FIG. 19 , when a washing stage is performed and wash water containing micro-bubbles is to be supplied, the control unit  40  or  40 ′ causes the first water supply valve  510  to be opened (S 100 ). In this case, the control unit  40 ,  40 ′ may be set to supply a set amount of wash water. Accordingly, the wash water is supplied to the dissolving unit  100 ,  100 ′ to generate the wash water containing micro-bubbles. 
     The supply of wash water containing the micro-bubbles may continue for a set time by opening the first water supply valve  510  (S 110 ). 
     When the set time has elapsed, the control unit  40 ,  40 ′ causes the second water supply valve  520  to be opened while the first water supply valve  510  remains opened (S 130 ). Accordingly, the wash water is supplied through two paths, and the amount of wash water supplied per unit time may be increased. 
     Thereafter, when the set amount of the supplied wash water is reached, the control unit  40 ,  40 ′ closes the first water supply valve  510  and the second water supply valve  520  to stop the supply of wash water. 
     However, the stages S 110  and S 120  described above are performed only when the wash water supplied within the set time does not reach the set amount. That is, if the wash water is supplied in the set amount only by supplying the wash water containing the micro-bubbles before the set time has elapsed, the control unit  40 ,  40 ′ closes the first water supply valve  510  to stop the supply of wash water. 
     In order to supply water containing micro-bubbles to the outer basket  20 ,  20 ′ and the inner basket  22 ,  22 ′ in the above stages, the control unit allows the wash water to be supplied to the dissolving unit  200 ,  200 ′ at set time intervals. Accordingly, when the supply of wash water to the dissolving unit  200 ,  200 ′ is stopped, gas fills the dissolving unit  200 ,  200 ′, and then micro-bubbles may be generated by newly supplied wash water. 
     The dissolving unit  100 ,  100 ′ according to the present disclosure may generate bubbles in the wash water using the water supply pressure of the wash water supplied through the water supply line L 1 , L 1 ′, without using a power device. Accordingly, the flow path passing through the dissolving unit  100 ,  100 ′ is longer than the flow path that does not pass through the dissolving unit  100 ,  100 ′. Therefore, the set amount of wash water may not be supplied to the laundry even after a relatively long period of time passes. 
     according to the method of supplying the wash water according to one embodiment of the present disclosure, if the set amount of wash water is not supplied (e.g., to the outer and/or inner baskets) even after the set time has elapsed, the wash water is supplied through two paths. Therefore, the delay in the wash water supply is reduced while the washing water containing micro-bubbles is supplied to the laundry. 
     As described above, embodiments of the disclosure provide a washing machine and a micro-bubble generator therefor capable of increasing the amount of micro-bubbles and improving washing abilities and rinsing abilities. 
     Further, embodiments of the disclosure provide a washing machine and a micro-bubble generator therefor in which the micro-bubbles do not disappear and may be supplied into an inner basket of the washing machine, in which the washing process is performed. 
     As described above, while the present disclosure has been described in connection with a washing machine, a micro-bubble generator of the washing machine, and a method of supplying wash water having micro-bubbles in the washing machine, it is merely an example, and the present disclosure is not limited thereto. It should be understood that the present disclosure has the widest range in compliance with the basic idea disclosed in the disclosure. Although it is possible for those skilled in the art to combine and substitute the disclosed embodiments to embody other types that are not specifically disclosed in the disclosure, they do not depart from the scope of the present disclosure as well. In addition, it will be apparent to those skilled in the art that various modifications and changes may be made with respect to the disclosed embodiments based on the disclosure, and these changes and modifications also fall within the scope of the present disclosure.