Patent Description:
In general, a washing machine is a device that washes laundry using a driving force of a motor to agitate laundry, wash water, and detergent introduced into a washing tub together so that washing is performed by mutual friction.

A detergent supply apparatus is an apparatus that allows a detergent to be evenly mixed and supplied together with water being supplied in a process of supplying water to the inside of a tub of the washing machine. When the detergent is a liquid detergent, the liquid detergent may be directly supplied into the tub.

The detergent supply apparatus is provided to be embedded in a front portion of an upper part of a main body of the washing machine, and includes a box-shaped housing having a front that is openable, and a detergent box mounted to enter the housing through the open front of the housing and detachable in the form of a drawer.

Recently, there is a use of a washing machine equipped with a liquid detergent supply apparatus in which a detergent box has a detergent input space formed inside for a liquid detergent such that a liquid detergent, such as a rinsing agent and a bleach, is used.

A detergent pump may be fixed to the housing to perform pumping to suction a detergent in the detergent box and discharge the detergent to the housing. Upon the detergent box entering the housing and being docked onto the detergent pump, the detergent in the detergent box may be suctioned into the detergent pump by the detergent pump and then discharged into the housing. The detergent discharged into the housing may be supplied into the tub together with water being supplied.

The detergent pump is provided with a detergent detecting unit for detecting the amount of a residual detergent. The detergent detecting unit is provided to, upon insufficiency of the detergent in the detergent box, display the result on a display unit of the washing machine. When the display unit of the washing machine indicates that the detergent is insufficient, the user undocks the detergent box from the detergent pump to replenish the detergent box. When the detergent box is undocked from the detergent pump, a detergent remaining in the detergent pump may fall to the bottom of the housing and may harden. When the detergent hardens on the bottom of the housing, the user may have an inconvenience of cleaning the detergent.

The detergent detecting unit is installed in a suction portion, which suctions a detergent of the detergent box upon the detergent box being docked onto the detergent pump, to detect the amount of a remaining detergent. The detergent detecting unit is provided in a form of a pair of sensors installed in the suction portion, and since all of the pair of sensors need to be installed in the suction portion, the suction portion may need to have a large diameter. In proportion to the increasing diameter of the suction portion, the amount of the detergent remaining in the suction portion may increase when the detergent box is undocked from the detergent pump, in which case the amount of the detergent falling to the bottom of the housing may also increase. <CIT> discloses a washing machine which includes a detergent supply apparatus comprising a detergent box and a detergent pump.

One aspect of the invention provides a detergent supply apparatus improved to prevent hardening of a detergent that falls to the bottom of a housing when a detergent box is undocked from a detergent pump to replenish detergent, and a washing machine having the same.

Another aspect of the invention provides a detergent supply apparatus having an improved installation position of a detergent detecting unit for detecting a remaining amount of detergent, and a washing machine having the same.

According to the invention, there is provided a washing machine according to claim <NUM>. Preferred features are set out in the dependent claims.

According to embodiments of the invention, a detergent remaining in a detergent pump can be prevented from directly falling to the bottom of a housing when a detergent box is separated.

The detergent pump may include: a fixing portion including a suction portion configured to suction a detergent from the detergent box and a discharge portion configured to discharge the detergent, which may be suctioned into the suction portion, to the housing; and a pumping portion configured to perform pumping so that detergent in the detergent box may be suctioned into the suction portion and then discharged by the discharge portion into the housing.

The auxiliary tank includes a water storage portion in which water is stored, and a drain port through which the water stored in the water storage portion may be drained, wherein the drain port may include a drain hole through which the water is drained, and a distribution rib at a lower side of the drain hole that distributes the water drained from the drain hole to the bottom of the housing.

The detergent box may include a detergent discharge portion configured to be docked to the suction portion to discharge the detergent to the suction portion, and an opening and closing member configured to, upon the detergent discharge portion being docked to the suction portion, close the drain hole, and upon the detergent discharge portion being undocked from the suction portion, open the drain hole.

The detergent discharge portion and the opening and closing member each protrude rearward from a rear surface of the detergent box with the detergent discharge portion protruding further from the rear surface of the detergent box than the opening and closing member.

The detergent discharge portion may be formed to protrude further than the opening and closing member such that, in a case the detergent discharge portion being undocked from the suction portion, the opening and closing member may open the drain hole before the detergent discharge portion is completely undocked from the suction portion.

The detergent box may be configured so that before the detergent discharge portion is completely undocked from the suction portion, the water stored in the water storage portion may be drained to the bottom of the housing through the drain hole.

The housing may include: an opening portion that may be open to allow a part of the fixing portion to pass therethrough; an extending portion extending from the opening portion, into which a remaining part of the fixing portion may be insertable to be fixed to the extending portion; and a water supply portion allowing detergent discharged from the discharge portion into the housing and through the opening portion to be supplied to the tub together with water.

The detergent box may include a first detergent box configured to hold a main detergent, and a second detergent box configured to hold a preliminary detergent, the detergent pump being configured to individually suction and discharge to the housing the main detergent and the preliminary detergent individually.

The detergent pump may include a first detergent pump configured to suction the main detergent from the first detergent box and discharge the main detergent to the housing, and a second detergent pump configured to suction the preliminary detergent from the second detergent box and discharge the preliminary detergent to the housing.

The washing machine may include a detergent detecting unit may be installed in the pumping portion to detect a detergent remaining in the detergent pump, the detergent detecting unit including a first detecting unit including a first sensor and a second sensor in the first detergent pump and a second detecting unit including a third sensor and a fourth sensor in the second detergent pump.

The first sensor and the second sensor have different heights from the bottom of the housing, and the third sensor, and the fourth sensor have different heights from the bottom of the housing.

In addition, a suction portion of a detergent pump is provided with a smaller diameter so that the amount of a detergent remaining in the suction portion can be reduced.

Embodiments described in the specification and configurations shown in the accompanying drawings are merely exemplary examples of the present disclosure, and various modifications may replace the embodiments and the drawings of the present disclosure at the time of filing of the present application.

Further, identical symbols or numbers in the drawings of the present disclosure denote components or elements configured to perform substantially identical functions.

Further, it should be understood that, although the terms "first," "second," etc. may be used herein to describe various elements, the elements are not limited by the terms, and the terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element without departing from the scope of the present disclosure. The term "and/or" includes combinations of one or all of a plurality of associated listed items.

Meanwhile, the terms "front", "rear", "upper", "lower", "front", "rear", "top" and "bottom" used in the following description are defined based on drawings, and the shape and position of each component are not limited by the terms.

Hereinafter, embodiments according to the disclosure will be described in detail with reference to the accompanying drawings.

<FIG> is a perspective view illustrating a state in which a door of a washing machine is opened and a detergent box is withdrawn according to an embodiment of the disclosure. <FIG> is a cross-sectional view illustrating a washing machine according to an embodiment of the disclosure.

Hereinafter, a direction in which a detergent box <NUM> of a detergent supply apparatus <NUM> is withdrawn from a housing <NUM> is defined as a front, and based on which a rear side, left and right sides, and upper and lower sides may be defined.

As shown in <FIG> and <FIG>, a washing machine may include a cabinet <NUM> forming the external appearance and accommodating various components therein, a tub <NUM> provided inside the cabinet <NUM> to store mixed water in which water and detergent are mixed, a drum <NUM> provided inside the tub <NUM> and configured to rotate while accommodating laundry therein, a driving device <NUM> rotating the drum <NUM>, and a detergent supplying detergent <NUM> providing a detergent to the tub <NUM>.

The cabinet <NUM> may be formed in a substantially hexahedral shape. The cabinet <NUM> may be formed in a box shape having an open front. The cabinet <NUM> may include a front panel 11a provided on the open front, side plates 11b and 11c disposed on the opposite lateral sides rearward of the front panel 11a, and a rear plate 11d provided at a rear of the cabinet <NUM>. In the embodiment of the disclosure, the rear plate 11d and the side plates 11b and 11c of the cabinet <NUM> are integrally formed with each other, but the aspect of the disclosure is not limited thereto. The cabinet <NUM> may include a base <NUM> provided on the bottom and a top cover 11e provided on the upper surface thereof.

The cabinet <NUM> may be provided on the front surface thereof with a control panel <NUM> including an input unit 16a for receiving operation commands from a user and a display unit 16b for displaying operation information of the washing machine.

The base <NUM> may include a lower frame 19a formed to cover a lower portion of the cabinet <NUM> and a lower reinforcing frame 19b formed to extend from the lower frame 19a.

The front panel 11a may be formed with an opening <NUM> through which laundry may be inserted into the drum <NUM>. The tub <NUM> and the drum <NUM> may be provided with openings through which laundry may be inserted or withdrawn through the front of cabinet <NUM>, and the openings of the tub <NUM> and the drum <NUM> may be provided at positions corresponding to the position of the opening <NUM> of the front panel 11a.

The opening <NUM> provided in the front panel 11a may be opened and closed by a door <NUM>. The door <NUM> may be rotatably mounted on the front panel 11a of the cabinet <NUM> by a hinge member (not shown). The door <NUM> may include a door frame <NUM> and a door glass <NUM>. The door glass <NUM> may be formed of a transparent tempered glass material to enable the inside of the cabinet <NUM> to be seen through.

A water supply device <NUM> including a water supply pipe 14a and a water supply valve 14b for controlling supply of water may be provided on an upper side of the tub <NUM>. In addition, a detergent supply apparatus <NUM> for supplying a detergent to the inside of the tub <NUM> during a water supply process may be installed on a front upper side of the tub <NUM>.

The detergent supply apparatus <NUM> may be connected to the tub <NUM> through a supply pipe <NUM>. Water supplied through the water supply pipe 14a, while passing through the detergent supply apparatus <NUM>, may be mixed with detergent, and the mixture of water and detergent may be supplied into the tub <NUM>. When the detergent is a liquid detergent, water of the water supply pipe 14a may be directly supplied into the tub <NUM> through a separate control valve (not shown), and the liquid detergent may be supplied into the tub <NUM> through a detergent supply pipe (not shown) via the detergent supply apparatus <NUM>, and then, finally. to the inside of the tub <NUM>.

A driving unit <NUM> may be provided behind the drum <NUM>. The driving unit <NUM> may be a component for rotating the drum <NUM> and may be provided to rotate the drum <NUM> by transmitting a driving force generated by a motor <NUM> to a rotary shaft <NUM>.

The motor <NUM> may include a fixed stator <NUM> and a rotor <NUM> that rotates by electromagnetically interacting with the stator <NUM>, to convert electrical power into mechanical rotational force.

The tub <NUM> may be provided to store mixed water in which water is mixed with detergent, and formed in a substantially cylindrical shape. The tub <NUM> may be fixed inside the cabinet <NUM>. The opening <NUM> of the front panel 11a may be connected to the tub <NUM> by a diaphragm <NUM>.

The diaphragm <NUM> may be provided at one side thereof with a spray nozzle <NUM> that is connected to a circulation hose <NUM> to inject circulating mixed water into the drum <NUM>. The spray nozzle <NUM> may be provided to evenly spray the mixed water to the entire laundry accommodated in the drum <NUM>. The circulation hose <NUM> may be connected to a circulation pump <NUM> for pumping the mixed water stored in a lower portion of the tub <NUM>.

The drum <NUM> may rotate inside the tub <NUM> in which laundry is lifted and dropped so that washing is performed. A plurality of lifters <NUM> may be provided inside the drum <NUM>.

A drain device (not shown) including a drain pipe (not shown) for draining water inside the tub <NUM>, a drain valve (not shown), and the like may be installed below the tub <NUM>.

The tub <NUM> may be provided to be elastically supported from the cabinet <NUM> by springs (not shown) provided on the upper side thereof and dampers <NUM> provided on the lower side thereof. That is, the springs and the dampers <NUM> absorb vibration energy between the tub <NUM> and the cabinet <NUM> when vibration generated during rotation of the drum <NUM> is transmitted to the tub <NUM> and the cabinet <NUM>, thereby attenuating the vibration.

<FIG> is an exploded view illustrating a part of a detergent supply apparatus according to an embodiment of the disclosure. <FIG> is a view illustrating a process in which a detergent pump of a detergent supply apparatus is fixed to a housing according to an embodiment of the disclosure. <FIG> is a side cross-sectional view illustrating a detergent supply apparatus according to an embodiment of the disclosure. <FIG> is a view illustrating a state in which an entry of a detergent discharge portion is completely submerged in a detergent according to an embodiment of the disclosure. <FIG> is a view illustrating a state in which an end tip of a second bent portion among bent portions is immersed in a detergent according to an embodiment of the disclosure. <FIG> is a view illustrating a state in which a detergent box is provided at a rear side thereof with a detergent discharge portion and an opening and closing member according to an embodiment of the disclosure. <FIG> is a view illustrating a state in which a detergent discharge portion protrudes further than an opening and closing member according to an embodiment of the disclosure. <FIG> is a view illustrating a process in which a detergent box is docked onto a detergent pump according to an embodiment of the disclosure.

Referring to <FIG>, the detergent supply apparatus <NUM> may include a housing <NUM> provided to have an opening <NUM> on the upper side of the tub <NUM> of the washing machine, a detergent box <NUM> inserted into or withdrawn from the housing <NUM> through the opening <NUM>, and a detergent pump <NUM> fixed to the housing <NUM> (see <FIG>).

The housing <NUM> may include the opening <NUM> provided in the front portion of the housing <NUM> to allow the detergent box <NUM> to be inserted or withdrawn therethrough, an opening portion <NUM> that is open to allow the detergent pump <NUM> fixed to the housing <NUM> to be connected to the detergent box <NUM>, an extending portion <NUM> extending from the opening portion <NUM> and allowing a part of the detergent pump <NUM> to be inserted and fixed thereto, a water supply portion <NUM> allowing a detergent discharged from the detergent box <NUM> to the housing <NUM> by the detergent pump <NUM> to be supplied to the tub <NUM> together with water, and a housing cover <NUM> covering an upper side of the housing <NUM> (see <FIG>).

The detergent box <NUM> in which detergent is stored may be inserted into and withdrawn from the housing <NUM> through the opening <NUM>. Upon the detergent box <NUM> being inserted into the housing <NUM> through the opening <NUM>, the detergent box <NUM> may be docked onto the detergent pump <NUM>.

The detergent box <NUM> may be docked onto the detergent pump <NUM> through the opening portion <NUM> of the housing <NUM>. Upon the detergent box <NUM> being docked onto the detergent pump <NUM> through the opening portion <NUM>, the detergent from the inside the detergent box <NUM> and passing through the detergent pump <NUM> may be discharged into the housing <NUM> through the opening portion <NUM>.

The extending portion <NUM> may extend from the opening portion <NUM> rearward of the opening portion <NUM>. The detergent pump <NUM> fixed to the rear side of the housing <NUM> may be fixed while with a fixing portion <NUM>, which will be described below, is inserted into the extending portion <NUM>.

The water supply portion <NUM> may be provided on the bottom of the housing <NUM>. The water supply portion <NUM> may be connected to the tub <NUM> through the supply pipe <NUM>. Detergent discharged from the detergent box <NUM> to the bottom of the housing <NUM> by the detergent pump <NUM> may be mixed with water, and supplied to the tub <NUM> through the water supply portion <NUM> (see <FIG>).

The housing cover <NUM> may cover the open upper side of the housing <NUM>. The housing cover <NUM> may include a plurality of water supply holes <NUM> for supplying water into the housing <NUM>. Water falling through the water supply holes <NUM> provided in a rear portion of the housing cover <NUM>, among the plurality of water supply holes <NUM>, may be supplied to an auxiliary tank <NUM>, which will be described below, to fill the water storage portion <NUM>.

The detergent box <NUM> may be inserted into or withdrawn from the housing <NUM> through the opening <NUM> of the housing <NUM>. The detergent box <NUM> may store a main detergent (a powder detergent or a liquid detergent), a preliminary detergent, fabric softener, and bleach. The detergent box <NUM> may include a first detergent box <NUM> in which the main detergent is stored, and a second detergent box <NUM> in which the preliminary detergent, fabric softener, and bleach are stored. For the sake of convenience of description, the main detergent (a powder detergent or a liquid detergent), the preliminary detergent, the fabric softener, and the bleach may each be referred to as detergent. The first detergent box <NUM> may include a first inlet 121a for injecting a detergent into the first detergent box <NUM> and a first cover 121b for opening and closing the first inlet 121a. The second detergent box <NUM> may include a second inlet 123a for injecting a detergent into the second detergent box <NUM> and a second cover 123b for opening and closing the second inlet 123a.

The detergent box <NUM> may include a detergent discharge portion <NUM> for discharging a detergent stored in the detergent box <NUM>. The detergent discharge portion <NUM> may be docked onto the detergent pump <NUM>. The detergent discharge portion <NUM> may be provided to protrude from the rear side of the detergent box <NUM> so as to be docked onto the detergent pump <NUM>. The detergent box <NUM> may be docked onto the detergent pump <NUM> to discharge a detergent to the detergent pump <NUM> through the detergent discharge portion <NUM>. The detergent discharge portion <NUM> may include a first detergent discharge portion 125a for discharging the detergent stored in the first detergent box <NUM> and a second detergent discharge portion 125b for discharging the detergent stored in the second detergent box <NUM>.

The detergent box <NUM> may include a bent portion <NUM> bent to have an "L" shape and provided on the upper side of the detergent discharge portion <NUM>. The bent portion <NUM> may be provided inside the detergent box <NUM>. The bent portion <NUM> may include a first bent portion 126a provided to extend forward from the upper side of the detergent discharge portion <NUM>, and a second bent portion 126b provided to extend vertically downward from the first bent portion 126a.

The detergent in the detergent box <NUM> may be discharged to the detergent pump <NUM> through the detergent discharge portion <NUM>. The detergent pump <NUM> may, based on a difference in pressures at an entry of the detergent discharge portion <NUM>, suction the detergent inside the detergent box <NUM> and discharge the suctioned detergent into the housing <NUM>.

The bent portion <NUM> may reduce the amount of unused detergent inside the detergent box <NUM>. That is, as shown in <FIG>, when the entry of the detergent discharge portion <NUM> is completely submerged in the detergent, the detergent pump <NUM> may form a normal pressure difference so that a desired amount of detergent may be suctioned into the detergent pump <NUM> and the detergent suctioned into the detergent pump <NUM> may be discharged to the housing <NUM>.

However, when a portion of the entry of the detergent discharge portion <NUM> is exposed to the air, the detergent pump <NUM> may not form a normal pressure difference, and thus a less amount of detergent than desired may be suctioned into the detergent pump <NUM>. In this case, since the amount of detergent suctioned into the detergent pump <NUM> is small, the amount of detergent discharged to the housing <NUM> is also small. Accordingly, the detergent that remains in the detergent box <NUM> without being suctioned into the detergent pump <NUM> may become unused detergent that may not be used for washing. As the amount of unused detergent increases, the washing performance may be lowered.

In order to reduce the amount of unused detergent, the bent portion <NUM> may be provided on the upper side of the detergent discharge portion <NUM> as shown in <FIG>. When the detergent inside the detergent box <NUM> is in an amount in which a part of the entry of the detergent discharge portion <NUM> is exposed to the air, the bent portion <NUM> may prevent the entry of the detergent discharge portion <NUM> from being exposed to the air. That is, when the end tip of the second bent portion 126b among the bent portions <NUM> is immersed in the detergent, the entry of the detergent discharge portion <NUM> may be prevented from being exposed to the air. As a result, the amount of unused detergent may be reduced by the length of the second bent portion 126b.

The detergent box <NUM> may include an opening and closing member <NUM> that opens and closes a drain hole <NUM> of the auxiliary tank <NUM> to be described below. The opening and closing member <NUM> may be provided to protrude from the rear side of the detergent box <NUM>. The opening and closing member <NUM> may close the drain hole <NUM> upon the detergent box <NUM> being inserted into the housing <NUM> and docked onto the detergent pump <NUM>. The opening and closing member <NUM> may open the drain hole <NUM> upon the detergent box <NUM> being undocked from the detergent pump <NUM>. Details thereof will be described below.

The detergent pump <NUM> may be fixed to the rear side of the housing <NUM>. The detergent pump <NUM> may include: a fixing portion <NUM> including a suction portion <NUM> configured to suction a detergent from the detergent box <NUM> upon the detergent pump <NUM> being docked onto the detergent pump, and a discharge portion <NUM> configured to discharge the detergent, which is suctioned to the suction portion <NUM>, to the housing <NUM>; and a pumping portion <NUM> configured to perform pumping such that the detergent is suctioned into the suction portion <NUM> and then discharged to the discharge portion <NUM>. The pumping portion <NUM> may be formed inside a cylinder <NUM>.

The detergent pump <NUM> may include a first detergent pump <NUM> suctioning a detergent from the first detergent box <NUM> and discharging the suctioned detergent into the housing <NUM>, and a second detergent pump <NUM> suctioning a detergent from the second detergent box <NUM> and discharging the suctioned detergent to the housing <NUM>.

The first detergent pump <NUM> may include: a first suction portion <NUM> configured to suction a detergent upon the first detergent discharge portion 125a of the first detergent box <NUM> being docked onto the first detergent pump <NUM>; a first discharge portion <NUM> configured to discharge the detergent, which is suctioned into the first suction portion <NUM>, to the housing <NUM>; and a first pumping portion <NUM> configured to perform pumping such that the detergent in the first detergent box <NUM> is suctioned into the first suction portion <NUM> and then discharged into the housing <NUM> through the first discharge portion <NUM> (see <FIG>).

The second detergent pump <NUM> may include: a second suction portion <NUM> configured to suction a detergent upon the second detergent discharge portion 125b of the second detergent box <NUM> being docked onto the second detergent pump <NUM>; a second discharge portion <NUM> configured to discharge the detergent which is suctioned into the second suction portion <NUM>, to the housing <NUM>; and a second pumping portion <NUM> configured to perform pumping such that the detergent in the second detergent box <NUM> is suctioned into the second suction portion <NUM> and then discharged into the housing <NUM> through the second discharge portion <NUM> (see <FIG>).

The detergent pump <NUM> may be provided with a detergent detecting unit <NUM> for detecting the remaining amount of detergent. The detergent detecting unit <NUM> may detect the remaining amount of detergent and display a notification that the detergent is insufficient on the display unit 16b of the washing machine when the amount of the detergent is insufficient. Upon a notification that the detergent is insufficient being displayed on the display unit 16b, the user may undock the detergent box <NUM> from the detergent pump <NUM> and withdraw the detergent box <NUM> from the housing <NUM> to replenish the detergent. Details of the detergent detecting unit <NUM> will be described below.

An auxiliary tank <NUM> is provided inside the housing <NUM>. The auxiliary tank <NUM> may be provided on a rear wall inside the housing <NUM>. The auxiliary tank <NUM> includes a water storage portion <NUM> for storing water therein and a drain port <NUM> for draining the water stored in the water storage portion <NUM>.

The water storage portion <NUM> may be filled with water falling through some of the plurality of water supply holes <NUM> provided in the housing cover <NUM>. That is, when water is supplied by the water supply device <NUM>, water falling through the water supply holes <NUM> provided in the rear portion of the housing cover <NUM> among the plurality of water supply holes <NUM> may be supplied to the water storage portion <NUM> and filled in the water storage portion <NUM>.

The drain port <NUM> may be provided in a front lower portion of the water storage portion <NUM>. The drain port <NUM> may include a drain hole <NUM> through which the water stored in the water storage portion <NUM> is drained, and a distribution groove <NUM> through which the water drained from the drain hole <NUM> is distributed and falls to the bottom of the housing <NUM>.

The drain hole <NUM>, upon the detergent box <NUM> being docked onto the detergent pump <NUM>, may be closed by the opening and closing member <NUM> of the detergent box <NUM>. While the drain hole <NUM> is closed by the opening and closing member <NUM>, water may be supplied from the water supply device <NUM> to fill the water storage portion <NUM> (see <FIG>).

The distribution groove <NUM> may be formed as a circular groove at a circumference of the drain hole <NUM>. Water falling to the bottom of the housing <NUM> through the drain hole <NUM> may be distributed by the distribution groove <NUM> and fall.

The opening and closing member <NUM> provided together with the detergent discharge portion <NUM> on the rear side of the detergent box <NUM> and serving to open and close the drain hole <NUM> may protrude at a length shorter than a length of the detergent discharge portion <NUM>. Since the opening and closing member <NUM> protrudes at a length shorter than a length of the detergent discharge portion <NUM>, in a case in which the detergent box <NUM> is undocked from the detergent pump <NUM>, the opening and closing member <NUM> may open the drain hole <NUM> earlier than it. That is, in a case in which the detergent box <NUM> is undocked from the detergent pump <NUM>, the opening and closing member <NUM> opens the drain hole <NUM> before the detergent box <NUM> is completely undocked from the detergent pump <NUM> such that water stored in the water storage portion <NUM> may fall to the bottom of the housing <NUM> through the drain hole <NUM>. This is to allow water to fall to the bottom of the housing <NUM> before a detergent remaining in the detergent pump <NUM> falls to the bottom of the housing <NUM>, subsequent to the detergent box <NUM> being undocked from the detergent pump <NUM>. Since a detergent remaining in the detergent pump <NUM> directly falling to the bottom of the housing <NUM> may harden on the bottom of the housing <NUM>, the user may need clean the detergent personally. However, when the opening and closing member <NUM> opens the drain hole <NUM> before the detergent box <NUM> is completely undocked from the detergent pump <NUM>, water falls to the bottom of the housing <NUM> through the drain hole <NUM>, after which the detergent box <NUM> may be completely undocked from the detergent pump <NUM>. That is, after the water first dropped on the bottom of the housing <NUM> forms a water film, the detergent box <NUM> is completely undocked from the detergent pump <NUM>, and thus the detergent may fall onto the water film. When the detergent falls onto the water film, the detergent together with the water may be supplied to the tub <NUM> through the water supply portion <NUM> (see <FIG>).

<FIG> is a view illustrating a configuration in which a drain port includes distribution ribs according to another embodiment of the disclosure.

As shown in <FIG>, the drain port <NUM> may include a drain hole <NUM> through which the water stored in the water storage portion <NUM> is drained, and a distribution rib <NUM> that allows the water drained from the drain hole <NUM> to be distributed and fall to the bottom of the housing <NUM>.

The configuration of the drain hole <NUM> and the configuration in which the drain hole <NUM> is opened and closed by the opening and closing member <NUM> of the detergent box <NUM> are the same as those shown in <FIG>, and thus descriptions thereof will be omitted.

The distribution rib <NUM> may be provided on the rear side of the drain hole <NUM>. The distribution rib <NUM> may be a V-shaped rib and may allow water falling from the drain hole <NUM> to be distributed and fall to the bottom of the housing <NUM>. Although only a configuration in which the distribution rib <NUM> is provided at a lower side of the drain hole <NUM> is illustrated as the embodiment, the distribution rib <NUM> may be provided in other forms as long as it can allow the water falling from the drain hole <NUM> to be distributed and fall to the bottom of the housing <NUM>.

<FIG> is a view illustrating a state in which a detergent detecting unit is fixed to a detergent pump according to an embodiment of the disclosure.

As shown in <FIG>, the detergent pump <NUM> may be provided with a detergent detecting unit <NUM> for detecting the remaining amount of detergent. The detergent detecting unit <NUM> may be provided with a plurality of sensors. The detergent detecting unit <NUM> may be installed in the pumping portion <NUM> to detect the remaining amount of detergent. The detergent detecting unit <NUM> may be fixed to the outside of a cylinder <NUM> that forms the pumping portion <NUM>.

Each of the detergent detecting units <NUM> including a plurality of sensors may be provided as a conductor so as to be directly connected to a wire W for transmitting a detected signal to a control unit (not shown). Since the detergent detecting unit <NUM> may be provided as a conductor and may be directly connected with the electric wire W, a separate connection part for connecting the electric wire W may not be required, thereby reducing the material cost. The detergent detecting unit <NUM> may include an electrode rod <NUM> fixed to the cylinder <NUM> while fixing the electric wire W, a washer <NUM> located on a lower side of the electrode rod <NUM>, and a sealing <NUM> provided on a lower side of the washer <NUM> and sealing the pumping portion <NUM>, which is an inside of the cylinder <NUM>. An end tip located at a side opposite to the electrode rod <NUM> of the detergent detecting unit <NUM> may be located in the pumping portion <NUM>, which is an inside of the cylinder <NUM>, to detect the remaining amount of detergent.

The detergent detecting unit <NUM> may include a first detecting unit <NUM> installed as a pair of sensors in the first pumping portion <NUM> and a second detecting unit <NUM> installed as a pair of sensors in the second pumping portion <NUM>.

The first detecting unit <NUM> may include a first sensor <NUM> and a second sensor <NUM> installed to have different heights based on the bottom of the housing <NUM>. The first sensor <NUM> may be installed at a position lower than that of the second sensor <NUM>. The remaining amount of detergent may be detected based on a difference in heights between the first sensor <NUM> and the second sensor <NUM>. That is, when both the first sensor <NUM> and the second sensor <NUM> detect the detergent, the amount of detergent stored in the detergent box <NUM> may be sufficient for use. However, when only the first sensor <NUM> at a relatively low position detects the detergent and the second sensor <NUM> at a relatively high position does not detect the detergent, the insufficiency of the detergent may be delivered to the control unit, and may be displayed on the display unit 16b of the washing machine (see <FIG>).

Since the first sensor <NUM> and the second sensor <NUM>, which form the first detecting unit <NUM>, are all installed in the first pumping portion <NUM>, the diameter of the first suction portion <NUM> for suctioning a detergent from the detergent box <NUM> may be minimized. That is, when the first sensor <NUM> and the second sensor <NUM> for detecting the remaining amount of detergent are installed in the first suction portion <NUM>, there is a restriction in minimizing the diameter of the first suction portion <NUM>, but when both the first sensor <NUM> and the second sensor <NUM> are installed in the first pumping portion <NUM>, the diameter of the first suction portion <NUM> may be minimized. Since the diameter of the first suction portion <NUM> is minimized, the amount of the detergent remaining in the first suction portion <NUM> upon the detergent box <NUM> being undocked from the detergent pump <NUM> may be reduced. Accordingly, the amount of the detergent falling from the detergent pump <NUM> to the bottom of the housing <NUM> upon the detergent box <NUM> being undocked from the detergent pump <NUM> may be reduced (see <FIG>).

The second detecting unit <NUM> may include a third sensor <NUM> and a fourth sensor <NUM> installed to have different heights based on the bottom of the housing <NUM>. The third sensor <NUM> may be installed at a position lower than that of the fourth sensor <NUM>. The remaining amount of detergent may be detected based on a difference in heights between the third sensor <NUM> and the fourth sensor <NUM>. That is, when both the third sensor <NUM> and the fourth sensor <NUM> detect the detergent, the amount of detergent stored in the detergent box <NUM> may be sufficient for use. However, when only the third sensor <NUM> at a relatively low position detects the detergent and the fourth sensor <NUM> at a relatively high position does not detect the detergent, the insufficiency of the detergent may be delivered to the control unit, and may be displayed on the display unit 16b of the washing machine (see <FIG>).

Since the third sensor <NUM> and the fourth sensor <NUM>, which form the second detecting unit <NUM>, are all installed in the second pumping portion <NUM>, the diameter of the second suction portion <NUM> for suctioning a detergent from the detergent box <NUM> may be minimized. That is, when the third sensor <NUM> and the fourth sensor <NUM> for detecting the remaining amount of detergent are installed in the second suction portion <NUM>, there is a restriction in minimizing the diameter of the second suction portion <NUM>, but when both the third sensor <NUM> and the fourth sensor <NUM> are installed in the second pumping portion <NUM>, the diameter of the second suction portion <NUM> may be minimized. Since the diameter of the second suction portion <NUM> is minimized, the amount of the detergent remaining in the second suction portion <NUM> upon the detergent box <NUM> being undocked from the detergent pump <NUM> may be reduced. Accordingly, the amount of the detergent falling from the detergent pump <NUM> to the bottom of the housing <NUM> upon the detergent box <NUM> being undocked from the detergent pump <NUM> may be reduced (see <FIG>).

The first sensor <NUM>, installed at a lower position, of the first detecting unit <NUM> and the third sensor <NUM>, installed at a lower position, of the second detecting unit <NUM> may be located at the same height. In addition, the second sensor <NUM>, installed at a higher position, of the first detecting unit <NUM> and the fourth sensor <NUM>, installed at a higher position, of the second detecting unit <NUM> may be located at the same height.

<FIG> is a view illustrating a state in which a detergent detecting unit is fixed to a detergent pump according to another embodiment of the disclosure.

As shown in <FIG>, when the distance between the first sensor <NUM> and the third sensor <NUM> located at the same height is shorter than the distance between the second sensor <NUM> and the fourth sensor <NUM>, the first sensor <NUM> and the third sensor <NUM> located at a shorter distance therebetween may be integrally formed with each other. When the first sensor <NUM> and the third sensor <NUM> are integrally formed with each other, the number of wires W individually connected to the first sensor <NUM> and the third sensor <NUM> may be reduced to one, thereby reducing the material costs. Although the first sensor <NUM> and the third sensor <NUM> located at a shorter distance therebetween may be integrally formed with each other, the first sensor <NUM> and the third sensor <NUM> may separately informed and connected to each other by a conductor. Even in this case in which the first sensor <NUM> and the third sensor <NUM> are connected to each other by a conductor, the number of wires W may be reduced to one, thereby reducing the material cost.

In the drawing, the first sensor <NUM> and the third sensor <NUM> are illustrated as being located at a distance shorter than a distance between the second sensor <NUM> and the fourth sensor <NUM>, and thus integrally formed with each other, but the disclosure is not limited thereto. That is, when the distance between the second sensor <NUM> and the fourth sensor <NUM> is shorter than the distance between the first sensor <NUM> and the third sensor <NUM>, the second sensor <NUM> and the fourth sensor <NUM> located at a shorter distance may be integrally formed with each other. When the second sensor <NUM> and the fourth sensor <NUM> are integrally formed with each other, the number of wires W connected to the second sensor <NUM> and the fourth sensor <NUM> may be reduced to one, thereby reducing the material costs. Although the second sensor <NUM> and the fourth sensor <NUM> installed at a shorter distance therebetween may be integrally formed, the second sensor <NUM> and the fourth sensor <NUM> may be formed separately and connected to each other by a conductor. Even in this case in which the second sensor <NUM> and the fourth sensor <NUM> are connected to each other by a conductor, the number of wires W may be reduced to one, thereby reducing the material cost.

Next, with reference to <FIG>, an operation of docking or unlocking the detergent box onto or from the detergent pump will be described in detail.

<FIG> is a view illustrating a state in which, upon a detergent box being docked onto a detergent pump, a detergent in a detergent box is suctioned into the detergent pump according to an embodiment of the disclosure. <FIG> is a view illustrating a process in which, upon a detergent box being docked onto a detergent pump, a detergent suctioned by a suction portion of the detergent pump is discharged via a pumping portion to a discharge portion according to an embodiment of the disclosure. <FIG> is a view illustrating a state in which, upon a detergent box being docked onto a detergent pump, a detergent detecting unit detects the remaining amount of detergent according to an embodiment of the disclosure. <FIG> is a view illustrating a state in which, upon a detergent box being docked onto a detergent pump, a detergent in the detergent box is discharged to the bottom of a housing by a detergent pump, and water supplied through a water supply hole is stored in a water storage portion according to an embodiment of the disclosure. <FIG> is a view illustrating a state in which a detergent detecting unit detects that the remaining amount of detergent is insufficient according to an embodiment of the disclosure. <FIG> is a view illustrating a state in which, upon a detergent box being undocked from a detergent pump to replenish the detergent box due to insufficiency of the remaining amount of detergent stored in the detergent box, an opening and closing member is opened for the water stored in an auxiliary tank is drained to the bottom of the housing according to an embodiment of the disclosure. <FIG> is a view illustrating a state in which upon a detergent box being completely undocked from a detergent pump, the detergent remaining in a suction portion of the detergent pump falls onto a water film on the bottom of the housing according to an embodiment of the disclosure. <FIG> is a view illustrating a state in which a detergent remaining in a suction portion of a detergent pump falls onto a water film on the bottom of a housing and is supplied to a water supply portion together with water.

For the sake of convenience of description, the following description will be made in relation that the detergent discharge portion <NUM> of the detergent box <NUM> shown in <FIG> is the first detergent discharge portion 125a, and the suction portion <NUM> of the detergent pump <NUM> is the first suction portion <NUM>.

As shown in <FIG>, when the detergent box <NUM> is inserted into the housing <NUM> and the first detergent discharge portion 125a of the detergent box <NUM> is docked onto the first suction portion <NUM> of the detergent pump <NUM>, the detergent in the detergent box <NUM> may be suctioned into the first suction portion <NUM> through the first detergent discharge portion 125a by a pumping of the detergent pump <NUM>.

As shown in <FIG>, the detergent suctioned into the first suction portion <NUM> through the first detergent discharge portion 125a may be discharged to the first discharge portion <NUM> via the first pumping portion <NUM>. The detergent suctioned into the second suction portion <NUM> through the second detergent discharge portion 125b may be discharged to the second discharge portion <NUM> through the second pumping portion <NUM>. In this case, as shown in <FIG>, both the first sensor <NUM> and the second sensor <NUM> of the detergent detecting unit <NUM> are immersed in the detergent, and thus the control unit may receive a signal indicating that the amount of the detergent is sufficient from the detergent detecting unit <NUM>.

As shown in <FIG>, when the detergent box <NUM> is docked onto the detergent pump <NUM> and the detergent stored in the detergent box <NUM> is discharged to the bottom of the housing <NUM> by the detergent pump <NUM>, water supplied from the water supply device <NUM> may be supplied to the water storage portion <NUM> of the auxiliary tank <NUM> through the water supply holes <NUM>. In this case, since the drain hole <NUM> of the auxiliary tank <NUM> is in a state closed by the opening and closing member <NUM> of the detergent box <NUM>, water supplied through the water supply holes <NUM> may fill the water storage portion <NUM>.

As shown in <FIG>, when only the first sensor <NUM> is immersed in the detergent as the remaining amount of detergent decreases, the detergent detecting unit <NUM> may transmit, to the control unit, a signal indicating that the amount of the detergent is insufficient, and the signal may be displayed on the display unit 16b of the washing machine (see <FIG>).

As shown in <FIG>, when the amount of detergent is insufficient, the detergent box <NUM> may be withdrawn from the housing <NUM> to replenish the detergent in the detergent box <NUM>. In a case in which the detergent box <NUM> is withdrawn from the housing <NUM>, the opening and closing member <NUM> may open the drain hole <NUM> of the auxiliary tank <NUM> before the first detergent discharge portion 125a of the detergent box <NUM> is completely undocked from the first suction portion <NUM> of the detergent pump <NUM>. Upon the drain hole <NUM> being opened, water stored in the water storage portion <NUM> may fall to the bottom of the housing <NUM>. The water falling to the bottom of the housing <NUM> may form a water film.

As shown in <FIG>, when the detergent box <NUM> is further withdrawn from the housing <NUM> and thus the first detergent discharge portion 125a of the detergent box <NUM> is completely unlocked from the first suction portion <NUM> of the detergent pump <NUM>, the detergent remaining in the first suction portion <NUM> may fall onto the water film on the bottom of the housing <NUM>. Since the detergent remaining in the first suction portion <NUM> does not directly fall to the bottom of the housing <NUM> but falls onto the water film, the detergent may be mixed with water and thus prevented from being hardened.

Claim 1:
A washing machine comprising:
a cabinet (<NUM>);
a tub (<NUM>) provided inside the cabinet to store water therein; and
a detergent supply apparatus (<NUM>) configured to supply detergent to the tub, the detergent supply apparatus including:
a housing (<NUM>) provided to have an opening (<NUM>) at an upper side of the tub;
a detergent box (<NUM>) provided to be inserted into and withdrawn from the housing through the opening;
a detergent pump (<NUM>) fixed to the housing to allow the detergent box to be docked thereonto or undocked therefrom, the detergent pump configured to, upon the detergent box being docked onto the detergent pump, suction a detergent from the detergent box and discharge the detergent to the housing;
characterized in that the washing machine further comprises:
an auxiliary tank (<NUM>) provided in the housing to store water therein, and including:
a water storage portion (<NUM>) in which water is stored, and
a drain port (<NUM>) through which the water stored in the water storage portion (<NUM>) is drained to the bottom of the housing to prevent the detergent from hardening on the bottom of the housing.