Patent Description:
<CIT> Al relates to a robot according to the preamble of independent claim <NUM> including: a body defining an exterior appearance of the robot cleaner; a cleaning module coupled to the body and capable of performing cleaning with water; a water tank capable of being withdrawn from the body, and storing water to be supplied to the cleaning module; and a light source disposed inside the body, and preset to allow emitted light to pass through the water tank and be then discharged to an outside of the body.

<CIT>relates to a wet wiping device with a housing, a cleaning element for cleaning a surface and a liquid tank that can be removably arranged on the housing.

Robot cleaners for cleaning the floor, which is a surface to be cleaned, have been launched, in which while moving on the surface to be cleaned, the robot cleaner removes foreign materials by sucking them from the surface, or while being in contact with the surface to be cleaned, the robot cleaner cleans the surface to be cleaned by wiping foreign materials from the surface.

A robot cleaner capable of mopping the surface to be cleaned performs cleaning by moving on the surface by rotational friction while rotating about a rotation axis, which is approximately perpendicular to the surface to be cleaned, and by mopping the surface with the rotational friction. Further, there is also disclosed a robot cleaner having a function of mopping the surface to be cleaned with a wet mop, in which a water tank is mounted in the robot cleaner to supply water in the water tank to spin mops which move by rotating to mop the floor.

In a robot cleaner having a water tank fixed thereto, it is a stable structure that water in the water tank is supplied to spin mops. However, a robot cleaner having a detachable water tank has a problem in that when water in the water tank is supplied to the spin mops while the water tank is mounted, water may leak from a connection portion.

Korean Laid-open Patent Publication No. <CIT> discloses a structure of a robot cleaner having a detachable water tank, but a fixing and a pressing means are not provided separately for a portion, at which water is supplied from the water tank to a mounting structure, causing a problem in that the water supplied into a body may partially leak to the outside.

Furthermore, if a strong fixing and pressing means are provided for the water tank and the mounting structure, there are problems in that it is difficult to separate the water tank from the mounting structure, and when a user attempts to separate the water tank, the water tank may be damaged or water in the water tank may leak.

It is an object of the present invention to provide a robot cleaner including a detachable water tank, in which the mounted water tank may be stably fixed.

It is another object of the present invention to provide a robot cleaner including a detachable water tank, in which water leakage, occurring at a portion where the water tank is connected, may be minimized.

It is yet another object of the present invention to provide a robot cleaner, in which while maintaining strong fixation at a connection portion between the water tank and the body, little force is required for a user to separate the water tank.

It is still another object of the present invention to provide a robot cleaner, in which a fixing means is disposed at one side of a water tank, and while rotating about the other side of the water tank as a center of rotation, the water tank may be connected to or separated from the body, thereby allowing smooth connection and separation between the water tank and the body.

The objects of the present invention are not limited to the aforementioned objects and other objects not described herein will be clearly understood by those skilled in the art from the following description.

In order to achieve the above objects, the present invention provides a robot cleaner, in which a fixing means generating a magnetic force is disposed at one side of a water tank, and while rotating about the other side of the water tank, the water tank may be connected to or separated from the body.

Specifically, in accordance with one aspect of the present invention, the above objects are accomplished by providing a robot cleaner, including: a water tank forming a space for storing water; a body having a water tank housing formed at a rear side thereof, the water tank housing forming a mounting space in which the water tank is mounted; a pair of spin mops rotatably mounted at a lower side of the body, and adapted to move the body by rotating and to mop a surface to be cleaned; a supply nozzle disposed at one side of the water tank housing, and when being connected to the water tank, supplying the water stored in the water tank to each of the pair of spin mops; a discharge nozzle disposed at a position spaced apart from a center of the water tank in a first direction, and when the water tank is mounted in the water tank housing, being connected to the supply nozzle to communicate the water tank with the supply nozzle: a fixing unit providing a coupling force between the water tank housing and the water tank by generating a magnetic force, and being spaced apart from the center of the water tank in the first direction; and a separation prevention unit being spaced apart from the center of the water tank in a direction opposite the first direction, and restricting forward and backward movement of the water tank in the mounting space.

The water tank is separated from the water tank housing by rotating about a point, adjacent to the separation prevention unit, in a forward direction.

The water tank may be connected to the water tank housing by rotating about the point, adjacent to the separation prevention unit, in a reverse direction.

The water tank may be separated from the water tank housing by rotating in the forward direction about an edge of the water tank housing adjacent to the separation prevention unit.

The fixing unit may include: a water-tank side fixing member disposed at the water tank; and a body-side fixing member disposed corresponding to the water tank-side fixing member in the water tank housing.

The water tank housing may include: an opening, through which the water tank enters; a housing front surface disposed to face the opening; and a first housing side surface and a second housing side surface, intersecting the housing front surface, having one end which defines a portion of the edge of the opening and the other end which is connected to the housing front surface, and being disposed to face other, wherein the body-side fixing member may be disposed on the housing front surface.

The body-side fixing member may be disposed on the housing front surface at a position adjacent to the first housing side surface.

The separation prevention unit may further include a separation prevention groove formed at the second housing side surface, and defining a space in which a portion of the water tank is locked.

The separation prevention groove may be biased toward the edge of the opening from a center of the second housing side surface.

The water tank may include a water tank case forming a space for storing water; and the water tank case has a case front surface being disposed to face the housing front surface when the water tank is connected to the water tank housing, a first case side surface and a second case side surface being disposed to face the first housing side surface and the second housing side surface, and a case rear surface being exposed to the outside, wherein the water tank-side fixing member may be disposed at the case front surface.

The separation prevention unit may include a separation prevention rib protruding from the second case side surface.

The separation prevention rib may include: a first portion extending from the second case side surface in a direction intersecting the second case side surface; and a second portion connected to the first portion, and extending in a direction intersecting the first portion.

The separation prevention unit may include: a stopper having an elastic restoring force to the mounting space from the second housing side surface; and a stopper groove, which is formed at the second case side surface and into which the stopper is inserted.

The water tank may further include an edge locking portion being locked on the edge of the opening of the water tank housing.

While being locked on the edge of the opening by the edge locking portion, the water tank may rotate to be separated from the water tank housing.

In accordance with another aspect of the present invention, the above objects are accomplished by providing a robot cleaner, including: a water tank forming a space for storing water; a body having a water tank housing formed at a rear side thereof, the water tank housing forming a mounting space in which the water tank is mounted; a pair of spin mops rotatably mounted at a lower side of the body, and adapted to move the body by rotating and to mop a surface to be cleaned; a water tank-side fixing member disposed at the water tank and connected to the water tank housing; a separation prevention unit disposed at a position opposite the water tank-side fixing member relative to a center of the water tank, and restricting forward and backward movement of the water tank in the mounting space; and an edge locking portion disposed at a position opposite the water tank-side fixing member relative to the center of the water tank, and being locked on an edge of an opening of the water tank housing.

While being locked on the edge of the opening by the edge locking portion, the water tank may rotate in a forward direction to be separated from the water tank housing.

While being locked on the edge of the opening by the edge locking portion, the water tank may rotate in a reverse direction to be connected to the water tank housing.

The edge locking portion and the separation prevention unit may be disposed on one same surface of the water tank.

The water tank-side fixing member may be disposed at another surface of the water tank intersecting the one surface of the water tank, on which the edge locking portion and the separation prevention unit are disposed.

Details of other embodiments are included in the detailed description and the accompanying drawings.

According to the present invention, the robot cleaner has one or more of the following effects.

Firstly, as a water tank-side fixing member and a body-side fixing member are disposed at a water tank and a water tank housing, respectively, such that the water tank may be mounted stably in the water tank housing. Particularly, in the case where a magnet is used as the body-side fixing member and the water tank-side fixing member, a strong attractive force is generated therebetween, such that the water tank may be fixed stably.

Secondly, a fixing means for fixing the water tank is only disposed near a pipe for supplying water, and a separation prevention unit for preventing the water tank from being separated from the body is disposed at a position opposite the pipe, such that a strong coupling force generated near the pipe may prevent leakage, and the water tank may be separated easily by a leverage effect produced by rotating the water tank with respect to the separation prevention unit, thereby reducing damage of the water tank during the separation.

Thirdly, an edge locking portion, being exposed at an outer surface of the body when the water tank and the body are connected, is provided at a position opposite the fixing means for fixing the water tank, such that the water tank rotates while being locked to the outer surface of the body, to be separated from the body, thereby producing a leverage effect, and facilitating separation of the separation prevention means.

Fourthly, each of the body-side fixing member and the water tank-side fixing member is arranged in a ring shape around a circumference of a supply nozzle and a discharge nozzle being provided for the flow of water, and the body-side fixing member and the water tank-side fixing member are firmly pressed against each other to prevent water leakage, thereby enabling smooth supply of water to spin mops.

Fifthly, a sealer is disposed at a portion where the fixing member is provided, to prevent water from flowing to the magnet, thereby maintaining a magnetic force, generated by the magnet, for an extended period of time, and securing a long service life of the magnet.

Sixthly, a handle for withdrawing the water tank from the water tank housing is disposed at a position where the fixing member is provided, thereby allowing a user to easily draw out the water tank, and providing convenience in using the water tank.

However, the effects of the present invention are not limited to the aforesaid, and other effects not described herein will be clearly understood by those skilled in the art from the following description of the appended claims.

Advantages and features of the present disclosure and methods for accomplishing the same will be more clearly understood from exemplary embodiments described below with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments, but may be implemented in various different forms. The embodiments are provided only to complete invention of the present invention and to fully provide a person having ordinary skill in the art to which the present invention pertains with the category of the present invention, and the present invention will be defined by the scope of the appended claims. Wherever possible, like reference numerals generally denote like elements through the specification.

In the description of a robot cleaner and a water tank, a direction in which the water tank is drawn out is defined as a rear direction, a direction opposite to the rear direction is defined as a front direction, a direction in which a spin mop is disposed is defined as a lower direction, a direction opposite to the lower direction is defined as an upper direction. Further, a direction of both sides which is perpendicular to the front direction, the rear direction, the upper direction and the lower direction is defined as a left-right direction. A configuration of the water tank will be described based on the above directions when the water tank is mounted in a water tank housing.

Specifically, a direction parallel to a virtual line, formed by connecting a central axis Osa of a left spin mop 41a and a central axis Osb of a right spin mop 41b, is defined as a left-right direction; a direction, which vertically intersects the left-right direction, and in which the water tank is positioned, is defined as a rear direction.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings provided for explaining a robot cleaner.

Referring to <FIG>, the overall configuration of a robot cleaner <NUM> according to an embodiment of the present invention will be described below.

The robot cleaner <NUM> according to the embodiment includes: a body <NUM> forming an exterior of the robot cleaner <NUM> and having an internal space; a pair of spin mops <NUM> being disposed at a lower side of the body <NUM>, moving the body <NUM> by rotating, and mopping a surface to be cleaned (floor surface); a water tank <NUM> being mounted at the body <NUM> and storing water to be supplied to the pair of spin mops <NUM>; and a water supply module, being disposed on the inside of the body <NUM> and supplying the water, stored in the water tank <NUM>, to each of the pair of spin mops <NUM>.

The robot cleaner <NUM> may include: a bumper <NUM> being mounted at the front of the body <NUM>, and when coming into contact with an obstacle located in front of the body <NUM>, detecting the obstacle or absorbing shock caused by the contact with the obstacle; and a sensor <NUM> disposed to recognize a position of the body <NUM>.

The body <NUM> may have a flat disc shape. In the internal space of the body <NUM>, a printed circuit board (not shown) is disposed, which includes a controller for adjusting the water supply module (not shown) and a rotation speed of the pair of spin mops <NUM> or adjusting an amount of water to be supplied from the water tank <NUM> to the pair of spin mops <NUM>. In the internal space of the body <NUM>, external power is supplied for charging, and the charged power is provided to the printed circuit board (not shown) or to a motor (not shown) for rotating the pair of spin mops <NUM>.

The water supply module may include: a supply nozzle <NUM> connected to the water tank <NUM> mounted at the body <NUM>; a supply hose (not shown) for connecting the supply nozzle <NUM> and each of the pair of spin mops <NUM>; and a pump (not shown) being disposed on the supply hose, and suctioning water stored in the water tank <NUM> to deliver the water to each of the pair of spin mops <NUM>.

The pair of spin mops 41a and 41b mop the floor by rotating clockwise or counterclockwise when viewed from the top. The pair of spin mops 41a and 41b include the left spin mop 41a and the right spin mop 41b. In this embodiment, the pair of spin mops <NUM> are provided to rotate about rotation axes Osa and Osb which extend substantially in an up-down direction.

The pair of spin mops 41a and 41b are disposed at a lower side of the body <NUM>. The pair of spin mops 41a and 41b are disposed in front of the water tank <NUM>.

Hereinafter, a water tank housing <NUM> according to an embodiment of the present disclosure will be described with reference to <FIG> and <FIG>.

The body <NUM> includes a water tank housing <NUM>, being disposed at the rear of the body <NUM> and forming a mounting space <NUM> in which the water tank <NUM> is mounted. The water tank housing <NUM> may be integrally formed with the body <NUM>. Alternatively, the water tank housing <NUM> may be provided separately from the body <NUM> and may be disposed at the rear of the body <NUM>. The water tank housing <NUM> forms the mounting space <NUM> corresponding to an outer shape of the water tank <NUM>, so that the water tank <NUM> may be mounted in the mounting space <NUM>.

For example, the water tank housing <NUM> is formed by a side surface 10b of the body <NUM> which is recessed inwardly, such that when the water tank <NUM> is coupled to the water tank housing <NUM>, at least one surface of the water tank <NUM> may be exposed to the outside. In this case, the exposed surface of the water tank <NUM> defines a portion of the side surface 10b of the body <NUM>.

Further, the water tank housing <NUM> may be formed as a space of the body <NUM> having an opening which is open to the side surface and the lower side of the body <NUM>. The open space at the lower side of the body <NUM> serves to expose a handle <NUM> of the water tank <NUM>.

The water tank housing <NUM> has a housing front surface <NUM>, a first housing side surface 104a, a second housing side surface 104b, a housing upper surface, and a housing lower surface <NUM>.

The housing front surface <NUM> comes into contact with or is disposed closest to the water tank <NUM> when the water tank <NUM> is mounted in the water tank housing <NUM>. The housing front surface <NUM> is disposed to face the opening of the water tank housing <NUM> or the side surface 10b of the body <NUM>. Specifically, the housing front surface <NUM> may define a surface which intersects a front-rear direction and is in parallel with an up-down direction and a left-right direction.

The first housing side surface 104a and the second housing side surface 104b form surfaces facing both side surfaces of the water tank <NUM>, and guide the water tank <NUM> when the water tank <NUM> is inserted into or withdrawn from the water tank housing <NUM>. One end of the first housing side surface 104a and the second housing side surface 104b defines a portion of an edge 104c of the opening of the water tank housing <NUM>. The other end of the first housing side surface 104a and the second housing side surface 104b is connected to the housing front surface <NUM>. The first housing side surface 104a and the second housing side surface 104b are disposed to intersect with the housing front surface <NUM>. The other end of the first housing side surface 104a and the second housing side surface 104b is connected to the side surface 10b of the body <NUM>, and defines both sides of the edge 104c of the opening of the water tank housing <NUM>.

The housing upper surface is disposed to face an upper surface of the water tank <NUM> when the water tank <NUM> is mounted in the water tank housing <NUM>. The housing upper surface coverts the top of the water tank <NUM> when the water tank <NUM> is mounted in the water tank housing <NUM>.

The housing lower surface <NUM> supports the water tank <NUM> when the water tank <NUM> is mounted in the water tank housing <NUM>. The housing lower surface <NUM> has a width smaller than the housing upper surface, and has a width smaller than the width of the water tank <NUM>, such that when the water tank <NUM> is mounted in the water tank housing <NUM>, the handle <NUM> of the water tank <NUM> is exposed.

The housing front surface <NUM>, the first housing side surface 104a, the second housing side surface 104b, the housing upper surface (not shown), and the housing lower surface <NUM> form the mounting space <NUM> in which the water tank <NUM> is mounted. The opening of the water tank housing <NUM> is formed with one side facing the housing front surface <NUM> and a portion of the housing lower surface <NUM> which are open.

Here, the time when the water tank <NUM> is mounted in the water tank housing <NUM> may refer to a state in which the front surface of the water tank <NUM> comes into contact with, or is disposed closest to, the housing front surface <NUM>, and a state in which a discharge nozzle <NUM> disposed at the water tank <NUM> and the supply nozzle <NUM> disposed at the water tank housing <NUM> are connected to each other, which will be described later.

At the housing front surface <NUM>, the supply nozzle <NUM> is disposed, which is connected to the water tank <NUM> when the water tank <NUM> is mounted in the water tank housing <NUM>. The supply nozzle <NUM> is spaced apart from the center of the water tank <NUM> in a first direction. Specifically, the supply nozzle <NUM> is spaced leftwardly apart from the center of the water tank <NUM>. More specifically, the supply nozzle <NUM> may be disposed at a position which is biased toward the first housing side surface 104a from the housing front surface <NUM>.

The supply nozzle <NUM> has: an insertion part <NUM>, forming an insertion space <NUM> for the discharge nozzle <NUM> of the water tank <NUM> to be inserted into the front of the housing front surface <NUM>; a connection nozzle <NUM>, having a hollow inner space and extending forward from the center of the insertion part <NUM>; a pressing nozzle <NUM>, having a hollow inner space and extending from the center of the insertion part <NUM> toward the water tank <NUM>; an insertion part sealer <NUM>, disposed at the insertion space <NUM> and pressed against the discharge nozzle <NUM> inserted into the insertion space <NUM>.

The insertion part <NUM> protrudes forward from the housing front surface <NUM> and forms the insertion space <NUM> inside the insertion part <NUM>. The insertion part <NUM> has: an insertion part circumferential surface <NUM>, protruding forward from the housing front surface <NUM> and forming the insertion space <NUM> in a cylindrical shape inside the insertion part <NUM>; and an insertion part front surface <NUM> disposed on an end portion of the insertion part circumferential surface <NUM>.

The insertion space <NUM> may be formed in an annular shape. The pressing nozzle <NUM> may be disposed in the middle of the insertion space <NUM>. The insertion part sealer <NUM> is disposed in the insertion space <NUM>. The insertion part sealer <NUM> is pressed against the discharge nozzle <NUM> of the water tank <NUM> when the water tank <NUM> is mounted in the water tank housing <NUM>, thereby preventing water, supplied from the discharge nozzle <NUM>, from leaking to the outside.

The insertion part sealer <NUM> may be disposed along the circumferential surface of the pressing nozzle <NUM>. The insertion part sealer <NUM> has: an end contact surface <NUM> disposed at the insertion part front surface <NUM> to come into contact with an end portion of an insertion nozzle <NUM> of the discharge nozzle <NUM>; a pressing nozzle contact surface <NUM>, connected to the end contact surface <NUM> and extending along the circumferential surface of the pressing nozzle <NUM>; and at least one contact protrusion <NUM> protruding from the pressing nozzle contact surface <NUM> toward the insertion space <NUM>.

The contact protrusion <NUM> protrudes from the pressing nozzle contact surface <NUM> toward the insertion part front surface <NUM> in a hopper shape.

The connection nozzle <NUM> protrudes forward from the insertion part front surface <NUM> and is connected to a supply hose (not shown) disposed inside the body <NUM>.

The pressing nozzle <NUM> protrudes rearward from the insertion part front surface <NUM> and presses one side of a discharge port valve <NUM> when the water tank <NUM> is mounted in the water tank housing <NUM>. The pressing nozzle <NUM> and the connection nozzle <NUM> are disposed in a front-rear direction and have hollow inner portions which communicate with each other.

The pressing nozzle <NUM> protrudes rearward of the housing front surface <NUM>. A spacing protrusion <NUM>, protruding rearward from a tubular portion formed by the pressing nozzle <NUM>, is disposed at an end portion of the pressing nozzle <NUM>. A plurality of spacing protrusions <NUM> are spaced apart along the tubular portion formed by the pressing nozzle <NUM>. Accordingly, even when the pressing nozzle <NUM> is in contact with the discharge port valve <NUM>, the pressing nozzle <NUM> is not blocked.

A body-side fixing member <NUM> for fixing the arrangement of the water tank <NUM>, mounted in the water tank housing <NUM>, is disposed at the water tank housing <NUM>. The body-side fixing member <NUM> and a water tank-side fixing member <NUM> may be collectively referred to as a fixing unit.

The body-side fixing member <NUM> may be disposed corresponding to the water tank-side fixing member <NUM> in the water tank housing <NUM>. The body-side fixing member <NUM> is disposed at the housing front surface <NUM>. Specifically, the body-side fixing member <NUM> is disposed at the housing front surface <NUM> at a position adjacent to the first housing side surface 104a.

In order to maintain a coupling force between the supply nozzle <NUM> and the discharge nozzle <NUM>, the body-side fixing member <NUM> may be disposed adjacent to the supply nozzle <NUM>. Specifically, the body-side fixing member <NUM> may have a ring shape disposed on the circumference of the insertion part <NUM>. As the body-side fixing member <NUM>, a permanent magnet generating a magnetic force may be used. A rare earth magnet having a strong magnetic force may also be used as the body-side fixing member <NUM>.

Referring to <FIG>, an auxiliary wheel <NUM> for supporting a rear portion of the body <NUM> may be disposed below the housing lower surface <NUM>.

Hereinafter, the water tank <NUM> according to an embodiment of the present disclosure will be described with reference to <FIG> and <FIG>.

The water tank <NUM> includes: a water tank case <NUM> forming a space for storing water; an opening cover for opening and closing an opening (not shown) formed at an upper side of the water tank case <NUM>; the discharge nozzle <NUM> connected to the supply nozzle <NUM> when the water tank <NUM> is mounted in the water tank housing <NUM>; and a water tank-side fixing member for maintaining the water tank <NUM> mounted in the water tank housing <NUM>.

The water tank case <NUM> has a shape corresponding to the mounting space <NUM> formed by the water tank housing <NUM>. Accordingly, the water tank case <NUM> may be inserted into or withdrawn from the mounting space <NUM> formed by the water tank housing <NUM>.

The water tank case <NUM> has: a case front surface <NUM> facing the housing front surface <NUM> when the water tank <NUM> is mounted in the water tank housing <NUM>; a first case side surface 206a and a second case side surface facing the first housing side surface 104a and the second housing side surface 104b; a case upper surface <NUM> facing the housing upper surface; a case lower surface <NUM> facing the housing lower surface <NUM>; and a case rear surface <NUM> disposed at the rear side and exposed to the outside.

An opening (not shown), which is open to supply water into the inside of the water tank case <NUM>, is formed on the upper side of the water tank case <NUM>, and the opening is provided with an opening cover <NUM> for opening and closing the opening. The opening cover <NUM> is disposed at the case upper surface <NUM>, and the opening cover <NUM> is disposed at the case upper surface <NUM> at which the opening is formed.

An air passage 222a for communicating the inside and outside of the water tank <NUM> is formed at the upper side of the water tank case <NUM>. The air passage 222a may be formed at a separate passage member <NUM> mounted at the upper side of the water tank case <NUM>. That is, as illustrated in <FIG>, the passage member <NUM>, having the air passage 222a, may be disposed at the case upper surface <NUM>.

The air passage 222a is formed at the case upper surface <NUM>. The case upper surface <NUM> may be spaced apart from the housing upper surface by a predetermined distance when the water tank <NUM> is mounted in the water tank housing <NUM>. Accordingly, even when water in the water tank <NUM> is discharged to the outside of the water tank <NUM> through the discharge nozzle <NUM> while the water tank <NUM> is mounted in the water tank housing <NUM>, external air may be drawn into the water tank <NUM> through the air passage 222a.

The discharge nozzle <NUM> is disposed at the case front surface <NUM>. The discharge nozzle <NUM> may be biased in a first direction on the case front surface <NUM>. The discharge nozzle <NUM> may be biased to the left side or to the right side of the case front surface <NUM>. The discharge nozzle <NUM> according to an embodiment of the present disclosure is biased to the left side of the case front surface <NUM>. A connection hose fixing member <NUM>, which will be described below, is biased to the left side of the case lower surface <NUM>, such that a length of the connection hose (not shown) may be minimized. The discharge nozzle <NUM> is connected to the supply nozzle <NUM> when the water tank <NUM> is mounted in the water tank housing <NUM>.

The discharge nozzle <NUM> includes: the insertion nozzle <NUM>, inserted into the insertion space <NUM> and having the discharge port 232a which is open to the front side; a discharge port valve <NUM> disposed behind the insertion nozzle <NUM> and serving to open and close the discharge port 232a by moving forwards and backwards; an elastic member <NUM> for applying an elastic force to the discharge port valve <NUM> in one direction; and a nozzle housing <NUM>, mounted into the water tank case <NUM> and forming a space for mounting the discharge port valve <NUM>.

The insertion nozzle <NUM> has a cylindrical shape and protrudes forward from the case front surface <NUM>. The insertion nozzle <NUM> is inserted into the insertion space <NUM> when the water tank <NUM> is mounted in the water tank housing <NUM>. When the water tank <NUM> is mounted in the water tank housing <NUM>, the insertion nozzle <NUM> may be disposed between the pressing nozzle <NUM> and the insertion part circumferential surface <NUM>. When the water tank <NUM> is mounted in the water tank housing <NUM>, the insertion nozzle <NUM> may be pressed against the insertion part sealer <NUM>.

The discharge port valve <NUM> is disposed in an inner space formed by the nozzle housing <NUM>, to move forwards and backwards. The discharge port valve <NUM> has: a first surface 234a being pressed against the pressing nozzle <NUM> when the water tank <NUM> is mounted in the water tank housing <NUM>; a second surface 234b being spaced apart rearward from the first surface 234a, and coming into contact with an internal sealer <NUM> to restrict forward movement of the discharge port valve <NUM>; and a guide protrusion 234c protruding rearward from the second surface 234b and moving the discharge port valve <NUM> along a valve moving guider <NUM> formed at the nozzle housing <NUM>.

A diameter 234aD of the first surface 234a is smaller than a diameter 234bD of the second surface 234b. The first surface 234a is spaced apart forward from the second surface 234b. The diameter 234aD of the first surface 234a is smaller than a diameter 250D of an inner circumferential surface of the internal sealer <NUM>. The diameter 234bD of the second surface 234b is greater than the diameter 250D of the inner circumferential surface of the internal sealer <NUM>. The second surface 234b comes into contact with the elastic member <NUM> disposed at the rear side. Accordingly, when no force is applied separately to the discharge port valve <NUM>, the discharge port valve <NUM> moves forward by the elastic member <NUM>. When no force is applied separately to the discharge port valve <NUM>, the discharge port valve <NUM> comes into contact with the internal sealer <NUM> by the elastic force of the elastic member <NUM>.

The guide protrusion 234c protrudes rearward from the second surface 234b. Referring to <FIG>, the discharge port valve <NUM> includes a pair of guide protrusions 234c in an up-down direction. A guide groove 234d, in which the valve moving guider <NUM> is disposed, is formed between the pair of guide protrusions 234c.

The nozzle housing <NUM> is mounted into the inside of the water tank case <NUM>. The nozzle housing <NUM> may be fixed to the inside of the water tank case <NUM> via a separate coupling member <NUM>.

Referring to <FIG>, the nozzle housing <NUM> includes an internal nozzle <NUM> protruding to the inside of the water tank <NUM>. The internal nozzle <NUM> protrudes downward from the nozzle housing <NUM>. A separate connection hose (not shown), extending to the case lower surface <NUM> of the water tank <NUM>, may be connected to the internal nozzle <NUM>. The connection hose fixing member <NUM> for fixing the other end of the connection hose may be disposed at the case lower surface <NUM>.

Referring to <FIG>, the nozzle housing <NUM> includes the valve moving guider <NUM>, protruding forward from a rear surface of the nozzle housing <NUM> and guiding the movement of the discharge port valve <NUM>. The valve moving guider <NUM> may be disposed at the guide groove 234d formed at the discharge port valve <NUM>. As the valve moving guider <NUM> is inserted into the guide groove 234d, the discharge port valve <NUM> may move forward and backward.

A plurality of sealers <NUM> and <NUM> are disposed between the nozzle housing <NUM> and an inner surface of the water tank <NUM>. An internal sealer <NUM> and an external sealer <NUM> are disposed between the nozzle housing <NUM> and the inner surface of the water tank <NUM>, in which the internal sealer <NUM> is disposed at a portion where the discharge port 232a is formed, and the external sealer <NUM> is disposed on an outer circumferential surface of the nozzle housing <NUM>.

The internal sealer <NUM> is disposed at the water tank case <NUM> having the discharge port 232a and restricts the movement of the discharge port valve <NUM> moving forward and backward. When the water tank <NUM> is not mounted in the water tank housing <NUM>, the discharge port valve <NUM> is pressed against the internal sealer <NUM>. The internal sealer <NUM> may have a ring shape. The internal sealer <NUM> may have a sealer opening 250a, formed at the center thereof and communicating with the discharge port 232a.

The external sealer <NUM> has a greater radius than the internal sealer <NUM>, which may be spaced apart from the external sealer <NUM> in a radial direction. The external sealer <NUM> may have an annular shape. The water tank-side fixing members 254a and 254b may be disposed between the internal sealer <NUM> and the external sealer <NUM>. Accordingly, the internal sealer <NUM> and the external sealer <NUM> may prevent water from flowing into the water tank-side fixing members 254a and 254b disposed between the internal sealer <NUM> and the external sealer <NUM>.

The water tank-side fixing members 254a and 254b, generating a magnetic force, are disposed between the nozzle housing <NUM> and the inner surface of the water tank <NUM>. The water tank-sider fixing members 254a and 254b are interposed between the external sealer <NUM> and the internal sealer <NUM>.

The water tank-side fixing members 254a and 254b are disposed at the case front surface <NUM>. When the water tank <NUM> is mounted in the water tank housing <NUM>, the water tank-side fixing members 254a and 254b are disposed adjacent to the body-side fixing members 140a and 140b.

As the water tank-side fixing members 254a and 254b, a permanent magnet generating a magnetic force may be used. Further, a rare earth magnet having a strong magnetic force may also be used as the water tank-side fixing members 254a and 254b.

The water tank <NUM> has a handle <NUM> being disposed at one side of the water tank case <NUM> and having a shape which allows a user to easily hold the water tank <NUM> when the user draws out the water tank <NUM> mounted in the water tank housing <NUM>. Referring to <FIG>, the handle <NUM> is disposed at the case lower surface <NUM>. Specifically, the handle <NUM> may be biased in a first direction (direction in which the water tank-side fixing member is biased) from the center of the case lower surface <NUM>.

As the handle <NUM> is formed at a position biased to the left from the center of the case lower surface <NUM>, torque may be provided easily to rotate the water tank <NUM> in one direction when a user pulls the handle <NUM>.

The fixing unit, generating a magnetic force, provides a coupling force between the water tank housing <NUM> and the water tank <NUM>, and is spaced apart from the center of the water tank <NUM> in the first direction.

A separation prevention unit limits forward and backward movement of the water tank <NUM> in the mounting space <NUM>. The separation prevention unit is spaced apart from the center of the water tank <NUM> in a direction opposite the first direction. The separation prevention unit and the fixing unit may be disposed in opposite directions relative to the center of the water tank <NUM>. Accordingly, the separation prevention unit may supplement a weakened coupling strength at the other end of the water tank <NUM> due to the fixing unit disposed at one side of the water tank <NUM>. Further, as will be described below, the separation prevention unit may provide the center of rotation of the water tank <NUM> at the beginning when the water tank <NUM> is separated from the water tank housing <NUM>.

For example, the separation prevention unit may include a separation prevention rib <NUM> and a separation prevention groove <NUM>. However, the separation prevention unit may have other structure, as will be described below.

The separation prevention rib <NUM> may be formed at the water tank <NUM> or the water tank housing <NUM>. The following description will be given based on a structure in which the separation prevention rib <NUM> is disposed at the water tank <NUM>. The separation prevention rib <NUM> protrudes outward from an outer surface of the water tank <NUM>. Specifically, the separation prevention rib <NUM> protrudes from the second case side surface 206b.

The separation prevention rib <NUM> may have a shape extending rightward from the second case side surface 206b. In this case, however, if the separation prevention groove <NUM> has a size similar to that of the separation prevention rib <NUM>, it is difficult for the separation prevention rib <NUM> to be connected to or separated from the separation prevention groove <NUM> when the water tank <NUM> rotates. Further, if a width (front-rear direction) of the separation prevention groove <NUM> is greater than a width of the separation prevention rib <NUM>, there is also a drawback in that the forward and rearward movement of the water tank <NUM> may not be restricted when the water tank <NUM> is connected to the water tank housing <NUM>.

In order to solve the above problems, the separation prevention rib <NUM> has a first portion 203a extending from the second case side surface 206b in a direction intersecting the second case side surface 206b; and a second portion 203b connected to the first portion 203a, and extending in a direction intersecting the first portion 203a. The separation prevention rib <NUM> may protrude rightward and may be bent forward.

In this case, a width of the first portion 203a in the front-rear direction is smaller than a length of the second portion 203b in the front-rear direction and is smaller than a width of the separation prevention groove <NUM> in the front-rear direction. Accordingly, there are effects in that when the water tank <NUM> is connected to the water tank housing <NUM>, the second portion 203b may limit the forward and backward movement of the water tank <NUM>; and when the water tank <NUM> rotates to be separated from the water tank housing <NUM>, the first portion 203a having a smaller width allows the separation prevention rib <NUM> to be easily separated from the separation prevention groove <NUM>. Further, at the beginning when the water tank <NUM> is connected to the water tank housing <NUM>, the first portion 203a also allows the separation prevention rib <NUM> to be easily inserted into the separation prevention groove <NUM>.

The separation prevention groove <NUM> is formed at one surface of the water tank housing <NUM>. The separation prevention groove <NUM> is formed at the second housing side surface 104b, and defines a space in which a portion of the water tank <NUM> (separation prevention rib <NUM>) is locked. A length of the separation prevention groove <NUM> in the left-right direction may be greater than a length of the separation prevention rib <NUM>. A width of the separation prevention groove <NUM> in the front-rear direction may be greater than a width of the first portion 203a in the front-rear direction or may be greater than or equal to a width of the second portion 203b in the front-rear direction.

There is no limitation on the position of the separation prevention groove <NUM> and the separation prevention rib <NUM>, but in order to rotate the water tank <NUM> about a position adjacent to the separation prevention means so that the water tank <NUM> may be separated, the separation prevention groove <NUM> may be biased toward the edge 104c of the opening from the center of the second housing side surface 104b. In this case, the separation prevention rib <NUM> may be biased toward the case rear surface <NUM> from the second case side surface 206b.

Referring to <FIG>, by rotating in a forward direction about a position adjacent to the separation prevention unit, the water tank <NUM> may be separated from the water tank housing <NUM>. By rotating in a reverse direction about the position adjacent to the separation prevention unit, the water tank <NUM> may be connected to the water tank housing <NUM>. Here, the forward direction may be a counterclockwise direction, and the reverse direction may be a clockwise direction, or vice versa.

Specifically, the water tank <NUM> may be separated from the water tank housing <NUM> in such a manner that when a user pulls the handle <NUM>, the water tank-side fixing member <NUM> is separated from the body-side fixing member <NUM>, and the water tank <NUM> rotates about a position, at which an outer surface of the water tank <NUM> comes into contact with the water tank housing <NUM>.

In this case, the water tank <NUM> may further include an edge locking portion <NUM>, limiting inward movement of the water tank <NUM> when the water tank <NUM> rotates, and creating a leverage effect for the water tank <NUM>. The edge locking portion <NUM> allows the water tank <NUM> to rotate about the edge 104c of the water tank housing <NUM>, and allows the water tank-side fixing member <NUM> and the body-side fixing member <NUM> to be easily separated from each other.

The edge locking portion <NUM> and the separation prevention unit may be disposed on one same surface of the water tank <NUM>. The edge locking portion <NUM> and the separation prevention unit may be disposed on one surface of the water tank <NUM>, which intersects the surface where the water tank-side fixing member <NUM> is disposed.

The edge locking portion <NUM> is locked in the opening of the water tank housing <NUM>. The edge locking portion <NUM> may protrude from a lower end of the second housing side surface 104b. The edge locking portion <NUM> may be inclined upward toward the right side. The edge 104c of the water tank housing <NUM> may be locked between the edge locking portion <NUM> and the second housing side surface 104b.

The edge locking portion <NUM> allows the center of rotation of the water tank <NUM> to be biased toward a rear right side of the water tank <NUM> from the outside of the water tank <NUM>, thereby facilitating separation of the water tank <NUM>.

The water tank <NUM> may be separated from the water tank housing <NUM> by rotating, in a forward direction, about the edge 104c of the water tank housing <NUM> being positioned adjacent to the separation prevention unit. Specifically, the water tank <NUM> rotates about the edge 104d of the water tank housing <NUM> as a central axis, in which the edge 104d is defined by connection of the second housing side surface 104a and the side surface 10b of the body <NUM>. The rotation axis of the water tank <NUM> may be in parallel with the up-down direction.

In another example, the water tank <NUM> rotates about the edge locking portion <NUM> as a central axis. While being locked on the edge 104c of the opening by the edge locking portion <NUM>, the water tank <NUM> rotates in the forward direction to be separated from the water tank housing <NUM>. While being locked on the edge 104c of the opening by the edge locking portion <NUM>, the water tank <NUM> rotates in the reverse direction to be connected to the water tank housing <NUM>.

Referring to <FIG>, a configuration of a water tank <NUM>, and a water tank housing <NUM> in which the water tank <NUM> is mounted, will be described below.

The overall configuration of the water tank <NUM> and the water tank housing <NUM> illustrated in <FIG> is broadly the same as that described above with reference to <FIG>. Accordingly, the water tank <NUM> and the water tank housing <NUM> illustrated in <FIG> will be described below based on configurations different from the water tank <NUM> and the water tank housing <NUM> described above with reference to <FIG>.

In another embodiment, a configuration of the separation prevention unit is different when compared to the embodiment of <FIG>.

The separation prevention unit according to another embodiment may include a stopper <NUM> and a stopper groove <NUM>. The stopper <NUM> is disposed at the second housing side surface 104b. The stopper <NUM> has an elastic restoring force to the mounting space <NUM> by a stopper elastic member <NUM>. When external pressure is applied, the stopper <NUM> may be inserted into the stopper groove <NUM> formed at the second housing surface 104b. The stopper <NUM> may reciprocate in a direction (left-right direction) intersecting the second housing side surface 104b. When there is no external force, the stopper <NUM> protrudes outside of the stopper groove <NUM> and protrudes inward from the second housing side surface 104b.

The stopper <NUM> includes: an inclined surface 160a being inclined rearwardly and downwardly, and a locking surface 160b extending toward the stopper groove <NUM>. When no external force is applied, the inclined surface 160a and the locking surface 160b of the stopper <NUM> protrude into the mounting space <NUM>. Accordingly, when the water tank <NUM> is inserted into the mounting space <NUM>, the water tank <NUM> comes into contact with the inclined surface 160a, such that the stopper <NUM> may move to the stopper groove <NUM>. However, once the water tank <NUM> is mounted in the water tank housing <NUM>, the stopper <NUM> is inserted into the stopper groove <NUM>, and the locking surface 160b prevents the water tank <NUM> from being withdrawn from the water tank housing <NUM>.

The water tank <NUM> has the stopper groove <NUM>, into which the stopper <NUM> is inserted when the water tank <NUM> is mounted in the water tank housing <NUM>, so as to fix the arrangement of the water tank <NUM>. The stopper groove <NUM> may have a shape corresponding to the inclined surface 160a and the locking surface 160b of the stopper <NUM>. The stopper groove <NUM> is formed at the second case side surface 206b.

The stopper <NUM> is disposed adjacent to the rear end of the second housing side surface 206b, and a portion connecting the inclined surface 160a and the locking surface 160b may be formed in a curved shape.

Referring to <FIG>, as illustrated in the embodiment of <FIG>, the water tank <NUM> may be separated from the water tank housing <NUM> by rotating about the edge stopper <NUM>.

A pair of spin mops 41a and 41b may be detachably mounted as a module at the body <NUM>. A module including the pair of spin mops 41a and 41b is defined as a mop module <NUM>.

Referring to <FIG> and <FIG>, the mop module <NUM> includes at least one floor cloth <NUM> which wipes the floor while rotating. The mop module <NUM> includes at least one spin mop <NUM>, which when viewed from above, rotates clockwise or counterclockwise while being in contact with the floor. The mop module <NUM> may include the pair of spin mops 41a and 41b. When viewed from above, the pair of spin mops 41a and 41b mop the floor by rotating clockwise or counterclockwise. The pair of spin mops 41a and 41b includes the left spin mop 41a and the right spin mop 41b. In the embodiment, the spin mops <NUM> are adapted to rotate about rotary shafts Osa and Osb extending substantially in an up-down direction.

The mop module <NUM> is disposed at a lower side of the body <NUM>. The mop module <NUM> is disposed behind a collecting module <NUM>.

Each of the left spin mop 41a and the right spin mop 41b includes the floor cloth <NUM>, a rotary plate <NUM>, and a spin shaft <NUM>. Each of the left spin mop 141a and the right spin mop 141b includes a water receiving part <NUM>. Each of the left spin mop 141a and the right spin mop 141b has a slave joint <NUM>.

The floor cloth <NUM>, the rotary plate <NUM>, the spin shaft <NUM>, the water receiving part <NUM>, and the slave joint <NUM>, which will be described below, may be understood to be provided for each of the left spin mop 41a and the right spin mop 41b.

The body <NUM> and the mop module <NUM> may be detachably coupled to each other. A state, in which the body <NUM> and the mop module <NUM> are coupled to each other, may be referred to as a "coupled state. " Further, a state, in which the body <NUM> and the mop module <NUM> are separated from each other, may be referred to as a "separated state. " The robot cleaner <NUM> includes a detaching module <NUM> which detachably engages the mop module <NUM> with the body <NUM>. In the coupled state, the detaching module <NUM> may release the engagement of the mop module <NUM> from the body <NUM>. The detaching module <NUM> operates to allow the mop module <NUM> and the body <NUM> to be detachably coupled to each other. In the separated state, the detaching module <NUM> may allow the mop module <NUM> to be engaged with the body <NUM>. The detaching module <NUM> may be disposed across a gap between the water tank <NUM> and the battery Bt.

The robot cleaner <NUM> includes a base <NUM> forming a lower surface of the body <NUM>. The base <NUM> forms a lower surface, a front surface, a rear surface, a left surface, and a right surface of the body <NUM>. The mop module <NUM> is coupled to the base <NUM>. The collecting module <NUM> is coupled to the base <NUM>. A controller Co and the battery Bt are disposed in an internal space formed by the case <NUM> and the base <NUM>. Further, a mop driving part <NUM> is disposed at the body <NUM>. A water supply module (not shown) is disposed at the body <NUM>. The detaching module <NUM> is disposed at the body <NUM>. The water supply module supplies water stored in the water tank <NUM> to the mop module <NUM>.

The robot cleaner <NUM> includes a module housing <NUM> forming an exterior of the mop module <NUM>. The module housing <NUM> is disposed at a lower side of the body <NUM>. The robot cleaner <NUM> includes a module cabinet <NUM> forming an exterior of the collecting module <NUM>. The module cabinet <NUM> is disposed at a lower side of the body <NUM>. The module housing <NUM> and the module cabinet <NUM> are spaced apart from each other in the front-rear direction.

The mop module <NUM> is detachably coupled to the body <NUM>. The mop module <NUM> is coupled to the lower side of the body <NUM>. The body <NUM> is coupled to the upper side of the mop module <NUM>. The body <NUM> includes a module mounting part <NUM>, and the mop module <NUM> includes a body mounting part <NUM>. The body mounting part <NUM> is detachably coupled to the module mounting part <NUM>.

The module mounting part <NUM> is provided at the lower side of the body <NUM>. The body mounting part <NUM> is provided at an upper side of the mop module <NUM>. The module mounting part <NUM> is disposed at a lower surface of the base <NUM>. The body mounting part <NUM> is dispose at an upper surface of the module housing <NUM>.

Any one of the module mounting part <NUM> and the body mounting part <NUM> protrudes in the up-down direction, and the other one thereof is recessed in the up-down direction to be engaged with the any one thereof.

In this embodiment, the body mounting part <NUM> protrudes upward from the mop module <NUM>. The module mounting part <NUM> is recessed upward from the body <NUM> to be engaged with the body mounting part <NUM>.

When viewed from the top, the body mounting part <NUM> has an asymmetric shape in the front-rear direction. If the mop module <NUM> is coupled to the body <NUM> while the front and rear sides of the mop module <NUM> are inverted, the body mounting part <NUM> may not be engaged with the module mounting part <NUM>. Accordingly, the body mounting part <NUM> having an asymmetric shape may allow the mop module <NUM> and the body <NUM> to be coupled to each other in a predetermined direction.

The mop module <NUM> includes a pair of body mounting parts 43a and 43b being spaced apart from each other. The pair of body mounting parts 43a and 43b correspond to the pair of spin mops 41a and 41b. The pair of body mounting parts 43a and 43b correspond to the pair of module mounting parts 36a and 36b.

The body <NUM> includes a pair of module mounting parts 36a and 36b being spaced apart from each other. The pair of module mounting parts 36a and 36b correspond to the pair of body mounting parts 43a and 43b.

The pair of body mounting parts 43a and 43b protrude upward from the mop module <NUM>. The pair of module mounting parts 36a and 36b are recessed upward to be engaged with the pair of body mounting parts 43a and 43b.

The module mounting part <NUM> includes a lower surface part <NUM> forming a lower surface. In the coupled state described above, the lower surface part <NUM> comes into contact with an upper surface part <NUM> of the body mounting part <NUM>. The lower surface part <NUM> is directed toward the lower side. The lower surface part <NUM> may be formed to be horizontal. The lower surface part <NUM> is disposed at an upper side of a corresponding peripheral part <NUM>.

The module mounting part <NUM> includes the corresponding peripheral part <NUM> disposed along the circumference of the lower surface part <NUM>. In the coupled state, the corresponding peripheral part <NUM> comes into contact with a periphery part <NUM> of the body mounting part <NUM>. The corresponding peripheral part <NUM> forms an inclined surface extending a lower surface of the base <NUM> and the lower surface part <NUM>. The corresponding peripheral part <NUM> has a slope which rises from the lower surface of the base <NUM> toward the lower surface part <NUM>. The corresponding peripheral part <NUM> is disposed to surround the lower surface part <NUM>.

The pair of module mounting parts <NUM> include a pair of locking surfaces 363a inserted into a space between the pair of body mounting parts <NUM>. In the corresponding peripheral part <NUM> of any one module mounting part <NUM>, the pair of locking surfaces 363a are disposed in a region close to the other adjacent module mounting part <NUM>. The locking surfaces 363a are disposed in a region which is relatively adjacent to a central perpendicular plane Po in the corresponding peripheral part <NUM>. The locking surfaces 363a form a portion of the corresponding peripheral part <NUM>.

The module mounting part <NUM> has a joint hole <NUM>, to which at least a portion of the master joint <NUM> is exposed. The joint hole <NUM> is formed at the lower surface part <NUM>. The master joint <NUM> may be disposed while passing through the joint hole <NUM>. The master joint <NUM> is coupled with the slave joint <NUM> to transmit a driving force of the mop driving part (not shown) to the spin mops <NUM>.

Protruding locking portions <NUM> and <NUM> are provided on a surface of any one of the module mounting part <NUM> and the body mounting part <NUM>, and corresponding locking portions <NUM> and <NUM>, being recessed to be engaged with the locking portions <NUM> and <NUM> in the coupled state, are provided on a surface of the other one of the module mounting part <NUM> and the body mounting part <NUM>.

The body mounting part <NUM> includes an upper surface part <NUM> forming an upper surface. The upper surface part <NUM> comes into contact with the lower surface part <NUM> of the module mounting part <NUM> in the coupled state. The upper surface part <NUM> is directed toward the upper side. The upper surface part <NUM> may be formed to be horizontal. The upper surface part <NUM> is disposed at the upper side of the peripheral part <NUM>.

The body mounting part <NUM> has the peripheral part <NUM> disposed along the circumference of the upper surface part <NUM>. In the coupled state, the peripheral part <NUM> comes into contact with the corresponding peripheral part <NUM> of the module mounting part <NUM>. The peripheral part <NUM> forms an inclined surface extending the upper surface of the module housing <NUM> and the upper surface part <NUM>. The peripheral part <NUM> has a slope which rises from the upper surface of the module housing <NUM> toward the upper surface part <NUM>. The peripheral part <NUM> is disposed to surround the upper surface part <NUM>.

The body mounting part <NUM> has a corresponding locking surface 433a coming into contact with the locking surface 363a in the coupled state. The pair of body mounting parts <NUM> has a pair of corresponding locking surfaces 433a. The pair of corresponding locking surfaces 433a are disposed to diagonally face each other on the left and right sides. The pair of corresponding locking surfaces 433a are disposed between the pair of body mounting parts <NUM>. In the peripheral part <NUM> of any one body mounting part <NUM>, the corresponding locking surfaces 433a are disposed in a region close to the other adjacent body mounting part <NUM>. The corresponding locking surfaces 433a are disposed in a region which is relatively adjacent to the central perpendicular plane Po in the peripheral part <NUM>. The corresponding locking surfaces 433a form a portion of the peripheral part <NUM>.

The body mounting part <NUM> has a drive hole <NUM>, to which at least a portion of the slave joint <NUM> is exposed. The drive hole <NUM> is formed at the upper surface part <NUM>. In the coupled state, the master joint <NUM> may be inserted into the drive hole <NUM> to be coupled to the slave joint <NUM>.

The corresponding locking portions <NUM> and <NUM> may be holes or grooves formed at the surface of the body mounting part <NUM>. The corresponding locking portions <NUM> and <NUM> may be disposed at the peripheral part <NUM>. A plurality of corresponding locking portions <NUM> and <NUM> may be provided, which correspond to the locking portions <NUM> and <NUM>.

The corresponding locking portions <NUM> and <NUM> include the first corresponding locking portion <NUM>, in which the first locking portion <NUM> is locked. The first corresponding locking portion <NUM> is formed at the corresponding locking surface 433a.

The corresponding locking portions <NUM> and <NUM> include a second corresponding locking portion <NUM>, in which the second locking portion <NUM> is locked. The second corresponding locking part <NUM> is formed at the peripheral part <NUM>.

The mop module <NUM> includes at least one spin mop <NUM>. The at least one spin mop <NUM> may include a pair of spin mops <NUM>. The pair of spin mops <NUM> may be symmetrical to each other with respect to a virtual central perpendicular plane. A left spin mop 41a and a right spin mop 41b are disposed to be bilaterally symmetrical to each other.

A lower surface of the left spin mop 41a and a lower surface of the right spin mop 41b are inclined. An overall lower surface of the left spin mop 41a is inclined leftwardly and downwardly. An overall lower surface of the right spin mop 41b is inclined rightwardly and downwardly. The lower surface of the left spin mop 41a has a lowest point on the left side. The lower surface of the left spin mop 41a has a highest point on the right side. The lower surface of the right spin mop 41b has a lowest point on the right side. The lower surface of the right spin mop 41b has a highest point on the left side.

The robot cleaner <NUM> moves by a frictional force with a ground surface, which is generated by the mop module <NUM>.

The mop module <NUM> may generate "a forward movement frictional force" for moving the body <NUM> forward, or a "rearward movement frictional force" for moving the body <NUM> backwards. The mop module <NUM> may generate a "leftward moment frictional force" for turning the body <NUM> to the left, or a "rightward moment frictional force" for turning the body <NUM> to the right. The mop module <NUM> may generate a frictional force by combining any one of the forward movement frictional force and the rearward movement frictional force with any one of the leftward moment frictional force and the rightward moment frictional force.

In order for the mop module <NUM> to generate the forward movement frictional force, the left spin mop 41a spins at a predetermined rpm R1 in a first forward direction wlf, and the right spin mop 41b spins at the predetermined rpm R1 in a second forward direction w2f.

In order for the mop module <NUM> to generate the rearward movement frictional force, the left spin mop 41a spins at a predetermined rpm R2 in a first reverse direction wlr, and the right spin mop 41b spins at the predetermined rpm R2 in a second reverse direction w2f.

The spin mop <NUM> includes the slave joint <NUM> rotating while being engaged with the master joint <NUM>. The master joint <NUM> is exposed outside of the body <NUM>. At least a portion of the slave joint <NUM> is exposed outside of the mop module <NUM>.

In the separated state, the master joint <NUM> and the slave joint <NUM> are separated from each other; and in the coupled state, the master joint <NUM> and the slave joint <NUM> are engaged with each other.

Any one of the master joint <NUM> and the slave joint <NUM> has a plurality of driving protrusions 65a disposed in a circumferential direction with respect to a rotation axis of the any one, and the other one thereof has a plurality of driving grooves <NUM> disposed in a circumferential direction with respect to a rotation axis of the other one.

The plurality of driving protrusions 65a are spaced apart from each other at predetermined intervals. The plurality of driving grooves <NUM> are spaced apart from each other at predetermined intervals. In the coupled state, the driving protrusions 65a are inserted into the driving grooves <NUM>. In the separated state, the driving protrusions 65a are separated from the driving grooves <NUM>.

Any one of the master joint <NUM> and the slave joint <NUM> has the plurality of driving protrusions 65a being spaced apart from each other in a circumferential direction with respect to a rotation axis of the any one, and the other one thereof has a plurality of facing protrusions 415a being spaced apart from each other in a circumferential direction with respect to a rotation axis of the other one. The plurality of facing protrusions 415a protrude in a direction of the any one thereof.

The plurality of facing protrusion 415a are spaced apart from each other at predetermined intervals. In the coupled state, any one of the driving protrusions 65a is disposed between two adjacent facing protrusions 415a. In the separated state, the driving protrusion 65a is separated from the two adjacent facing protrusions 415a. In the coupled state, at least one of the facing protrusion 415a is disposed between two adjacent driving protrusions 65a. According to the embodiment of the present disclosure, in the coupled state, two facing protrusions 415a are disposed between two adjacent driving protrusions 65a.

A protruding end of the facing protrusions 415a is formed to be rounded. A protruding end of the facing protrusions 415a is formed to be rounded in an arrangement direction of the plurality of facing protrusions 415a. The protruding end of the facing protrusions 415a has a rounded corner, which is rounded in a direction of adjacent facing protrusions 415a with respect to a central axis of a protruding direction. In this manner, when the separated state is changed to the coupled state, the driving protrusions 65a may be moved smoothly along the rounded protruding end of the facing protrusions 415a, to be inserted into the driving grooves <NUM>.

In this embodiment, the master joint <NUM> has the driving protrusions 65a, and the slave joint <NUM> has the driving grooves <NUM>. In this embodiment, the slave joint <NUM> includes the facing protrusions 415a. The following description will be given based on this embodiment.

The slave joint <NUM> is fixed to an upper end of the spin shaft <NUM>. The slave joint <NUM> has a driven shaft 415b fixed to the spin shaft. The slave joint <NUM> has the facing protrusions <NUM> protruding from the driven shaft 415b. The facing protrusions <NUM> protrude from the driven shaft 415b toward the master joint <NUM> in the up-down direction.

The module housing <NUM> connects the pair of spin mops 41a and 41b. By the module housing <NUM>, the pair of spin mops 41a and 41b may be separated together from the body <NUM> and may be connected together to the body <NUM>. The body mounting part <NUM> is disposed at an upper side of the module housing <NUM>. The spin mops <NUM> may be rotatably supported by the module housing <NUM>. The spin mops <NUM> may be disposed to pass through the module housing <NUM>.

The module housing <NUM> may have an upper cover <NUM> forming an upper part, and a lower cover <NUM> forming a lower part. The upper cover <NUM> and the lower cover <NUM> are connected to each other. The upper cover <NUM> and the lower cover <NUM> form an inner space which partially accommodates the spin mops <NUM>.

Suspension units <NUM>, <NUM>, and <NUM> may be disposed at the module housing <NUM>. The suspension units <NUM>, <NUM>, and <NUM> may be disposed in the inner space formed by the upper cover <NUM> and the lower cover <NUM>. The suspension units <NUM>, <NUM>, and <NUM> support the spin shaft <NUM> in a manner that allows the spin shaft <NUM> to be movable in an up-down direction within a predetermined range. In the embodiment, the suspension units <NUM>, <NUM>, and <NUM> has a tilting frame <NUM>, a tilting shaft <NUM>, and an elastic member <NUM>.

The module housing <NUM> may have a limit for restricting a rotation range of the tilting frame <NUM>.

The limit may include a lower limit <NUM> for limiting a downward rotation range of the tilting frame <NUM>. The lower limit <NUM> may be disposed at the module housing <NUM>. Once the tilting frame <NUM> rotates downward to the maximum, the lower limit <NUM> comes into contact with a lower limit contact part <NUM>. When the robot cleaner <NUM> is normally disposed on an external horizontal plane, the lower limit contact part <NUM> is spaced apart from the lower limit <NUM>. As there is no force pushing the lower surface of the spin mop <NUM> upward, the tilting frame <NUM> rotates to a maximum angle, the lower limit contact part <NUM> comes into contact with the lower limit <NUM>, and an inclination angle is maximum.

The limit may include an upper limit (not shown) for limiting an upward rotation range of the tilting frame <NUM>. In the embodiment, as the master joint <NUM> is pressed against the slave joint <NUM>, an upward rotation range of the tilting frame <NUM> may be limited. When the robot cleaner <NUM> is normally disposed on an external horizontal plane, the master joint <NUM> is pressed against the slave joint <NUM> to the maximum, and an inclination angle is minimum.

The module housing <NUM> has a second support <NUM> for fixing an end portion of the elastic member <NUM>. When the tilting frame <NUM> rotates, the elastic member <NUM> is elastically deformed or elastically restored by the second support <NUM> fixed to the module housing <NUM>.

The module housing <NUM> has a tilting shaft support <NUM> for supporting the tilting shaft <NUM>. The tilting shaft support <NUM> supports both ends of the tiling shaft <NUM>.

The mop module <NUM> includes a module water supply part <NUM> for guiding water, introduced from the water tank <NUM>, to the spin mops <NUM> in the coupled state described above. The module water supply part <NUM> guides water from top to bottom. A pair of module water supply parts <NUM> may be provided corresponding to the pair of spin mops 41a and 41b.

The module water supply part <NUM> may include a corresponding water supply part <NUM> for receiving water from the water tank <NUM>. The corresponding water supply part <NUM> is connected to a water supply connection part <NUM>. The corresponding water supply part <NUM> has a groove, into which the water supply connection part <NUM> is inserted. The corresponding water supply part <NUM> is disposed at the body mounting part <NUM>. The corresponding water supply part <NUM> is disposed at the upper surface part <NUM> of the body mounting part <NUM>. The corresponding water supply part <NUM> is formed at a surface of the body mounting part <NUM> which is recessed downwardly.

The module water supply part <NUM> has a water delivery part <NUM> for guiding water, introduced into the corresponding water supply part <NUM>, to a water supply guide part <NUM>. The water delivery part <NUM> may be disposed at the module housing <NUM>. The water delivery part <NUM> may protrude downward from an upper inner surface of the upper cover <NUM>. The water delivery part <NUM> may be disposed below the corresponding water supply part <NUM>. The water delivery part <NUM> may be provided to allow water to drop down. The corresponding water supply part <NUM> and the water delivery part <NUM> may have holes vertically communicating with each other, and water falls through the holes.

The module water supply part <NUM> includes the water supply guide part <NUM> for guiding the water, introduced into the corresponding water supply part <NUM>, to the spin mops <NUM>. The water, introduced into the corresponding water supply part <NUM>, flows into the water supply guide part <NUM> through the water delivery part <NUM>.

The water supply guide part <NUM> is disposed at the tilting frame <NUM>. The water supply guide part <NUM> is fixed to a frame base <NUM>. Water flows into a space, formed by the water supply guide part <NUM>, through the corresponding water supply part <NUM> and the water delivery part <NUM>. By minimizing scattering of water, the water supply guide part <NUM> may guide all of water to flow into the water receiving part <NUM>.

The water supply guide part <NUM> may include an inflow part 445a forming a space which is recessed from top to bottom. The inflow part 445a may accommodate a lower end portion of the water delivery part <NUM>. The inflow part 445a may form a space having an open upper side. The water, passing through the water delivery part <NUM>, flows in through the upper opening of the space of the inflow part 445a. One side of the space of the inflow part 445a is connected to a flow path at which a flow path part 445b is formed.

The water supply guide part <NUM> may have the flow path part 445b connecting the inflow part 445a and a discharge part 445c. One end of the flow path part 445b is connected to the inflow part 445a, and the other end of the flow path part 445b is connected to the discharge part 445c. A space formed by the flow path part 445b serves as a water passage. The space of the flow path part 445b is connected to the space of the inflow part 445a. The flow path part <NUM> may be formed as a channel having an open upper side. The flow path part 445b may have a slope which decreases from the inflow part 445a toward the discharge part 445c.

The water supply guide part <NUM> may have the discharge part 445c for discharging water into a water supply space Sw of the water receiving part <NUM>. A lower end of the discharge part 445c may be disposed in the water supply space Sw. The discharge part 445c has a hole connected to an upper space of the rotary plate <NUM> in an inner space of the module housing <NUM>. The hole of the discharge part 445c vertically connects the two spaces. The discharge part 445c has a hole vertically passing through the tilting frame <NUM>. The space of the flow path part 445b is connected to the hole of the discharge part 445c. The lower end of the discharge part 445c may be disposed in the water supply space Sw of the water receiving part <NUM>.

The tilting frame <NUM> is connected to the module housing <NUM> via the tilting shaft <NUM>. The tilting frame <NUM> rotatably supports the spin shaft <NUM>.

The tilting frame <NUM> is adapted to be rotatable about tilting rotation axes Ota and Otb within a predetermined range. The tilting rotation axes Ota and Otb extend in a direction crossing rotation axes Osa and Osb of the spin shaft <NUM>. The tilting shaft <NUM> is disposed on the tilting rotation axes Ota and Otb. The left tilting frame <NUM> is rotatable about the tilting rotation axis Ota within a predetermined range; and the right tilting frame <NUM> is rotatable about the tilting rotation axis Otb within a predetermined range.

The tilting frame <NUM> may be tilted within a predetermined angular range relative to the mop module <NUM>. The tiling frame <NUM> may allow the inclination angle to be changed depending on a floor condition. The tiling frame <NUM> may function as a suspension (supporting weight and mitigating vertical vibration at the same time) of the spin mops <NUM>.

The tilting frame <NUM> has a frame base <NUM> forming a lower surface thereof. The spin shaft <NUM> is disposed to vertically pass through the frame base <NUM>. The frame base <NUM> may be formed in a plate shape having a vertical thickness. The tilting shaft <NUM> rotatably connects the module housing <NUM> and the frame base <NUM>.

A bearing Ba may be provided between a rotary shaft support <NUM> and the spin shaft <NUM>. The bearing Ba may include a first bearing B1 disposed at a lower side, and a second bearing B2 dispose at an upper side.

A lower end of the rotary shaft support <NUM> is inserted into the water supply space Sw of the water receiving part <NUM>. An inner peripheral surface of the rotary shaft support <NUM> supports the spin shaft <NUM>.

The tilting frame <NUM> includes a first support <NUM> supporting one end of the elastic member <NUM>. The other end of the elastic member <NUM> is supported by a second support <NUM> disposed at the module housing <NUM>. When the tilting frame <NUM> is tilted with respect to the tilting shaft <NUM>, the position of the first support <NUM> is changed, and the length of the elastic member <NUM> is changed.

The first support <NUM> is fixed to the tilting frame <NUM>. The first support <NUM> is disposed on a left side of the left tilting frame <NUM>. The first support <NUM> is disposed on a right side of the right tilting frame <NUM>. The second support <NUM> is disposed in a left region of the left spin mop 41a. The second support <NUM> is disposed in a right region of the right spin mop 41b.

The first support <NUM> is fixed to the tilting frame <NUM>. When the titling frame <NUM> is tilted, the first support <NUM> is tilted along with the tilting frame <NUM>. At a minimum inclination angle, a distance between the first support <NUM> and the second support <NUM> is minimum; and at a maximum inclination angle, a distance between the first support <NUM> and the second support <NUM> is maximum. At a minimum inclination angle, the elastic member <NUM> is elastically deformed to provide a restoring force.

The tilting frame <NUM> has the lower limit contact part <NUM> provided to come into contact with the lower limit <NUM>. A lower surface of the lower limit contact part <NUM> may come into contact with an upper surface of the lower limit <NUM>.

The tilting shaft <NUM> is disposed at the module housing <NUM>. The tilting shaft <NUM> serves as a rotation axis of the tilting frame <NUM>. The tilting shaft <NUM> may extend in a direction perpendicular to a tilting direction of the spin mops <NUM>. In the embodiment, the tilting shaft <NUM> may be disposed to extend in a horizontal direction. In the embodiment, the tilting shaft <NUM> extends in a direction tilted at an acute angle in the front-rear direction.

The elastic member <NUM> applies an elastic force to the tilting frame <NUM>, so that a tilt angle of the lower surface of the spin mops <NUM> relative to the horizontal plane increases.

When the tilting frame <NUM> rotates downward, the elastic member <NUM> expands, and when the tilting frame <NUM> rotates upward, the elastic member <NUM> contracts. The elastic member <NUM> allows the tilting frame <NUM> to act in a shock-absorbing manner (elastically). The elastic member <NUM> applies a moment force to the tilting frame <NUM> in a direction in which an inclination angle increases.

The spin mops <NUM> have the rotary plate <NUM> provided to rotate at a lower side of the body <NUM>. The rotary plate <NUM> may be a circular plate-shaped member centered on the spin shaft <NUM>. The floor cloth <NUM> is fixed to a lower surface of the rotary plate <NUM>. The rotary plate <NUM> rotates the floor cloth <NUM>. The spin shaft <NUM> is fixed to the center of the rotary plate <NUM>.

The rotary plate <NUM> includes a right rotary plate <NUM> being spaced apart from a left rotary plate <NUM>. A lower surface of the left rotary plate <NUM> forms a downward slope which is inclined leftwardly and forwardly, and a lower surface of the right rotary plate <NUM> forms a downward slope which is inclined rightwardly and forwardly.

The rotary plate <NUM> has a floor cloth fixing part 412c for fixing the floor cloth <NUM>. The floor cloth fixing part 412c may detachably fix the floor cloth <NUM>. The floor cloth fixing part 412c may be Velcro and the like disposed at the lower surface of the rotary plate <NUM>. The floor cloth fixing part 412c may be a hook disposed at an edge of the rotary plate <NUM>.

A water supply hole 412a, vertically penetrating the rotary plate <NUM>, is provided. The water supply hole 412a connects the water supply space Sw and the lower side of the rotary plate <NUM>. Water in the water supply space Sw flows to the lower side of the rotary plate <NUM> through the water supply hole 412a. Water in the water supply space Sw flows to the floor cloth <NUM> through the water supply hole 412a. The water supply hole 412a is disposed at the center of the rotary plate <NUM>. The water supply hole 412a is disposed at a position except a position of the spin shaft <NUM>. Specifically, the water supply hole 412a is disposed at a position where the water supply hole <NUM> does not overlap with the spin shaft <NUM> in a vertical direction.

The rotary plate <NUM> may have a plurality of water supply holes <NUM>. A connection part 412b is disposed between the plurality of water supply holes 412a. The connection part 412b connects a portion of the rotary plate <NUM> in a centrifugal direction XO and a portion of the rotary plate <NUM> in an opposite direction XI of the centrifugal direction. Here, the centrifugal direction XO refers to a direction moving away from the spin shaft <NUM>, and the opposite direction XI of the centrifugal direction refers to a direction moving toward the spin shaft <NUM>.

The plurality of water supply holes 412a may be spaced apart from each other along a circumferential direction of the spin shaft <NUM>. The plurality of water supply holes <NUM> may be spaced apart from each other at predetermined intervals. The plurality of connection parts 412b may be spaced apart from each other along a circumferential direction of the spin shaft <NUM>. The water supply hole 412a is disposed between the plurality of connection parts 412b.

The rotary plate <NUM> includes a slope 412d disposed at the lower end portion of the spin shaft <NUM>. Water in the water supply space S2 flows down by gravity along the slope 412d. The slope 412d is formed along a circumference of the lower end of the spin shaft <NUM>. The slope 412d is inclined downward in the opposite direction XI of the centrifugal direction. The slope 412d may form a lower surface of the water supply hole 412a.

The spin mops <NUM> have the floor cloth <NUM> being connected to the lower side to the rotary plate <NUM> to come into contact with a floor. The floor cloth <NUM> may be replaceably mounted at the rotary plate <NUM>. The floor cloth <NUM> may be detachably fixed to the rotary plate <NUM> using Velcro, hook, and the like. The floor cloth <NUM> may be provided alone or in combination with a spacer (not shown). The floor cloth <NUM> is a part for wiping the floor while being in direct contact with the floor.

The spin mop <NUM> has the spin shaft <NUM> for rotating the rotary plate <NUM>. The spin shaft <NUM> is fixed to the rotary plate <NUM> to transmit torque of the mop driving part <NUM> to the rotary plate <NUM>. The spin shaft <NUM> is connected to the upper side of the rotary plate <NUM>. The spin shaft <NUM> is disposed at the center of the upper side of the rotary plate <NUM>. The spin shaft <NUM> is fixed to the center of rotations Osa and Osb (rotary shaft) of the rotary plate <NUM>. The spin shaft <NUM> has a joint fixing part 414a for fixing the slave joint <NUM>. The joint fixing part <NUM> is disposed at the upper end of the spin shaft <NUM>.

The mop module <NUM> has the water receiving part <NUM> being disposed at the upper side of the rotary plate <NUM> to receive water. The water receiving part <NUM> forms the water supply space Sw, in which water is received. The water receiving part <NUM> forms the water supply space Sw by surrounding the circumference of the spin shaft <NUM>, while being spaced apart therefrom. The water receiving part <NUM> collects water in the water supply space Sw until water, supplied to the upper side of the rotary plate <NUM>, passes through the water supply hole <NUM>. The water supply space Sw is disposed at the center of the upper side of the rotary plate <NUM>. The water supply space Sw has a cylindrical volume on the whole. The water supply space Sw has an open upper side. Water is introduced into the water supply space Sw through the upper side of the water supply space Sw.

The water receiving part <NUM> protrudes upward from the rotary plate <NUM>. The water receiving part <NUM> extends in a circumferential direction of the spin shaft <NUM>. The water receiving part <NUM> may be a ring-shaped rib. The water supply hole 412a is disposed at an inner lower surface of the water receiving part <NUM>. The water receiving part <NUM> is spaced apart from the spin shaft <NUM>.

A lower end of the water receiving part <NUM> is fixed to the rotary plate <NUM>. An upper end of the water receiving part <NUM> has a free end <NUM>.

Claim 1:
A robot cleaner (<NUM>), comprising:
a water tank (<NUM>) forming a space for storing water;
a body (<NUM>) having a water tank housing (<NUM>) formed at a rear side thereof, the water tank housing (<NUM>) forming a mounting space (<NUM>) in which the water tank (<NUM>) is mounted;
a pair of spin mops (<NUM>) rotatably mounted at a lower side of the body (<NUM>), and adapted to move the body (<NUM>) by rotating and to mop a surface to be cleaned;
a supply nozzle (<NUM>) disposed at one side of the water tank housing (<NUM>), and when being connected to the water tank (<NUM>), supplying the water stored in the water tank (<NUM>) to each of the pair of spin mops (<NUM>);
a discharge nozzle (<NUM>) disposed at a position spaced apart from a center of the water tank (<NUM>) in a first direction, and when the water tank (<NUM>) is mounted in the water tank housing (<NUM>), being connected to the supply nozzle (<NUM>) to communicate the water tank with the supply nozzle (<NUM>);
a separation prevention unit being spaced apart from the center of the water tank (<NUM>) in a direction opposite the first direction, and restricting forward and backward movement of the water tank (<NUM>) in the mounting space (<NUM>);
characterized in that the robot cleaner (<NUM>) further comprises a fixing unit providing a coupling force between the water tank housing (<NUM>) and the water tank (<NUM>) by generating a magnetic force, and being spaced apart from the center of the water tank (<NUM>) in the first direction; whereby the water tank (<NUM>) is separated from the water tank housing (<NUM>) by rotating about a point, adjacent to the separation prevention unit, in a forward direction.