Cleaning robot

A cleaning robot to prevent a suction member from moving upwards when the suction member is rotated during a collision with an obstacle, and which completely unfolds the suction member when a lower surface of the suction member travels on an uneven floor. The cleaning robot includes a main body to travel on a floor to be cleaned, a dust collecting unit, and a corner cleaning unit. The corner cleaning unit includes a suction member having a suction arm with a rotatable cylinder, a movable member rotatably coupled around the rotatable cylinder by a torsion spring such that the movable member can move upwards and downwards together with the suction member, a driving unit, supporting brackets, at least one elevation guide face to allow the movable member to move upwards and downwards along the elevation guide face as the movable member rotates, and at least one guide knob.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under Korean Patent Application No. 2006-129456, filed on Dec. 18, 2006, respectively, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present general inventive concept relates to a cleaning robot, and more particularly to a cleaning robot having a corner cleaning unit to clean a corner adjacent to a wall, and a method thereof.

2. Description of the Related Art

A conventional cleaning robot is a cleaning apparatus that draws foreign materials such as dust from a floor while independently traveling in a cleaning area. The cleaning robot having a corner cleaning unit for cleaning a corner adjacent to a wall is disclosed in Japanese Patent Application Publication No. 2004-337301.

The corner cleaning unit disclosed in this document includes a suction member that is rotatably coupled to a main body to be unfolded outwards and is provided with a suction port at a lower portion thereof, and a rotational support that rotatably supports the suction member. The rotational support is provided with spiral guide slots on an inner surface thereof to allow the suction member to be raised and lowered by means of rotation, and the suction member is provided with protrusions inserted into the guide slots. Further, a torsion spring is interposed between the suction member and the rotational support.

With the above construction, the suction member can be unfolded by the elasticity of the torsion spring to maintain the unfolded state.

In the above corner cleaning unit, because the protrusions of the suction member are guided to be lowered by the guide slots of the rotational support when the suction member is unfolded outwards by means of rotation, the suction member is lowered. In contrast, because the suction member is rotated in an opposite direction when the suction member is folded toward the main body, and the protrusions of the suction member are guided to be raised by the guide slots of the rotational support, the suction member is raised.

However, the corner cleaning unit of the cleaning robot is adapted to allow the suction member to be rotated and folded when the suction member collides with an obstacle (e.g. the leg of a sofa, the leg of a chair, etc.) while the main body is traveling. In this case, the suction member is raised, and is greatly separated from the floor. As a result, a cleaning effect is degraded.

Further, when the cleaning robot travels on an uneven floor like a carpet, its wheels are buried under the surface of the carpet by means of the weight of the main body, the suction member is not sufficiently unfolded, and thus all the desired corner regions cannot be covered. Moreover, when the corner cleaning unit is not used, the suction member must be manually rotated and folded. Thus, the cleaning robot is inconvenient to use.

SUMMARY OF THE INVENTION

The present general inventive concept provides a cleaning robot to prevent a suction member from moving upwards when the suction member is rotated during a collision with an obstacle.

The present general inventive concept also provides a cleaning robot to completely unfold a suction member when a lower surface of the suction member travels along an uneven floor, such as a carpet.

The present general inventive concept also provides a cleaning robot to automatically fold and unfold the suction member.

The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing a cleaning robot, which includes a main body to travel on a floor to be cleaned, a dust collecting unit installed in the body, and a corner cleaning unit installed in the body. The corner cleaning unit may include a suction member having a suction arm unfolded from the main body by means of rotation and a rotatable cylinder connected to the suction arm, a movable member rotatably coupled around the rotatable cylinder of the suction member by means of a torsion spring such that the movable member is able to move upwards and downwards together with the suction member, a driving unit to rotate the movable member, supporting brackets provided in the body to support the driving unit, at least one elevation guide face formed at one of the supporting brackets to allow the movable member to move upwards and downwards along the elevation guide face as the movable member rotates, and at least one guide knob provided to the movable member in such a manner that the guide knob can move upwards and downwards along the elevation guide face.

The supporting brackets may be formed with rotation guide faces which extend from a lower end of each elevation guide face in the same direction as a rotating direction of the suction member to guide a rotational movement of the guide protrusion that has moved downwards along the elevation guide face.

A space may be formed above the elevation guide face and the rotation guide faces to allow the guide knob to move upwards.

The driving unit may include a cylindrical rotor installed on an outer surface of the movable member to rotate the movable member, and may be formed with long guide slots aligned in a longitudinal direction in order to guide upward and downward movement of the guide protrusion, and a driving motor coupled with the support bracket to rotate the cylindrical rotor in a forward or reverse direction.

The driving unit may also include a driving gear coupled to a shaft of the driving motor to transmit rotational force of the driving motor to the cylindrical rotor, and a driven gear provided at an outer surface of the cylindrical rotor to be engaged with the driving gear.

The cylindrical rotor may be rotatably supported on the support bracket in a state in which the upward and downward movement of the cylindrical rotor is restricted.

Also, the cylindrical rotor may be provided therein with a coil spring to bias the movable member in a downward direction.

The rotatable cylinder may be provided therein with a suction channel, and the suction channel may be connected to the dust collecting unit through a connecting pipe.

The guide knobs may be provided with rollers, respectively, in such a manner that the rollers are able to roll along the elevation guide faces and the rotation guide faces.

The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing a cleaning robot, which includes a main body to travel on a floor to be cleaned, a dust collecting unit installed in the main body, and a corner cleaning unit installed in the main body. The corner cleaning unit may include a suction member having a suction arm unfolded from the main body by means of rotation and a rotatable cylinder connected to the suction arm, and a driving motor to rotate the rotatable cylinder in a forward or reverse direction to automatically fold or unfold the suction arm.

The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing a cleaning robot, including a main body, and a corner cleaning unit having a suction member, and to move the suction member in a folding direction and an unfolding direction with respect to the main body, and to move the suction member in an upward direction and a downward direction with respect to the main body, when the suction member moves to the folding direction and the unfolding direction.

The corner cleaning unit may control the suction member to simultaneously move in the unfolding direction and the downward direction, and to simultaneously move in the folding direction and the upward direction.

The corner cleaning unit may include a driving unit mounted to the main body to control the suction member to move in one of the folding direction and the unfolding direction, and a bracket mounted to the main body to guide the suction member to move in one of the downward direction and the upward direction.

The cleaning robot may further include a movable member disposed between the driving unit and the suction member, wherein the driving unit includes a rotor having a slot to allow the movable member in the upward and downward direction with respect to the rotor.

The bracket may include an elevation guide face inclined with respect to the slot of the rotor to guide the movable member in the upward and downward directions when the movable member moves along the slot.

The bracket may further include a rotation guide face extended from the elevation guide face to guide the suction member between the folding direction and the unfolding direction when the suction member has been moved to the downward direction along the elevation guide face.

The bracket may further include a rotation guide face to maintain a downward position while moving between the folding direction and the unfolding direction.

The bracket may further include a rotation guide face to guide the suction member to move between the folding direction and the unfolding direction when the driving unit does not control the suction member.

The bracket may include a rotation guide face to maintain the suction member in an unfolding state after the suction member moves to the unfolding direction.

The cleaning robot may further include an elastic unit coupled between the suction member and the driving unit to control the suction member and the driving unit to control the suction member to move along the rotation guide face in the unfolded state.

The cleaning robot may further include an elastic member coupled between the suction member and the driving unit to control the suction member to move with respect to the rotation guide face in the unfolded state.

The corner cleaning unit may control the suction member to maintain an unfolded state after moving to the unfolding direction and the downward direction.

The corner cleaning unit may control the suction member to move in a first direction and a second direction in the unfolded state according to a height of a first reference and a distance of a second reference with respect to the main body.

The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing a method of cleaning a surface using a cleaning robot with a main body and a suction member, the method including moving the suction member in a folding direction and an unfolding direction with respect to the main body, and moving the suction member in an upward direction and a downward direction with respect to the main body, when the suction member moves to the folding direction and the unfolding direction.

The method may further include controlling the suction member to simultaneously move in the unfolding direction and the downward direction, and to simultaneously move in the folding direction and the upward direction.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As illustrated inFIGS. 1 and 2, a cleaning robot according to an embodiment of the present general inventive concept includes a dust collecting unit20installed in a main body10, a traveling unit30to move the main body10, and a corner cleaning unit40to clean a corner adjacent to a wall.

The main body10has a roughly circular shape to facilitate easy turning. The main body10includes a lower case11, and an upper case12disposed above the lower case11to cover the lower case11and components installed therein. As illustrated inFIG. 2, the main body10is provided with a plurality of obstacle sensors13at predetermined intervals at an outer circumferential portion of the main body10thereof. The obstacle sensors13can measure a distance between the main body10and an obstacle or between the main body10and a wall by sending out a signal such as an ultrasonic wave, and receiving a reflected signal.

The traveling unit30includes two traveling wheels31and32that are diagonally installed to a lower central portion of the main body10, two traveling motors33and34to independently drive the traveling wheels31and32, respectively, and a turn wheel35installed at a lower front portion of the main body10. The traveling unit30causes the traveling motors33and34to rotate the traveling wheels31and32, respectively, in a forward or backward direction according to a control signal of a controller (not illustrated), thereby allowing the main body10to travel. The traveling direction of the main body10is determined by differentially controlling rotating directions and speeds of the traveling motors33and34. The turn wheel35has the structure of a caster capable of freely pivoting in the traveling direction of the main body10.

Although not illustrated in detail, the dust collecting unit20in the main body10may include a suction fan (not illustrated) to draw in foreign material such as dust and dirt together with air through a main suction port21formed on a lower surface of the main body10, a suction motor which drives the suction fan, and a filtering unit which filters the foreign materials from the drawn-in air. The filtering unit can include a regular cyclone or dust bag.

A suction duct22and a suction guide pipe23, all of which guide the suction of the foreign materials and air, are interposed between the dust collecting unit20and the main suction port21. As illustrated inFIG. 2, the main suction port21can be rotatably provided with a brush24. The brush24can include a turbine brush rotated by the force of wind or a power brush rotated by an electric motor.

As illustrated inFIGS. 2 and 3, the corner cleaning unit40is radially installed at a rear edge of the main body10. As illustrated inFIG. 4, the corner cleaning unit40includes an upper supporting bracket41and a lower supporting bracket42coupled to the main body10, a suction member50rotatably and elevatably coupled to both the upper supporting bracket41and the lower supporting bracket42, and a driving unit70to move and/or rotate the suction member50.

As illustrated inFIGS. 4 and 5, the suction member50includes a suction arm51that is formed long in a transverse direction and is provided therein with a horizontal suction channel51a, and a rotatable cylinder52that extends upwards from one end of the suction arm51and is provided therein with a vertical suction channel52ato communicate with the horizontal suction channel51aof the suction arm51and the connecting pipe80and the dust collecting unit20. The suction arm51is provided with a suction port53, which draws foreign materials together with air, at a lower surface thereof. As illustrated inFIGS. 2 and 3, the suction arm51rotates about the rotatable cylinder52, so that the suction port53allows the suction arm51to be unfolded from or folded to the main body10. That is, the suction arm51moves during a folded state and an unfolded state with respect to the main body10.

As illustrated inFIGS. 4 and 5, the rotatable cylinder52of the suction member50has a cylindrical movable member44fitted therearound, which can move up and down together with the suction member50while simultaneously rotating relative to the rotatable cylinder52. In order to install the movable member44, the rotatable cylinder52is provided with a ring groove54on an outer surface thereof, and the ring groove54is fitted with a snap ring55to restrict the movable member44to the upward and the downward movement with respect to the rotatable cylinder52. Specifically, the movable member44is first fitted around the rotatable cylinder52, and then the snap ring55is fitted into the ring groove54of the rotatable cylinder52such that a top surface of the movable member44is caught.

A torsion spring56is installed between the suction arm51of the suction member50and the movable member44. The torsion spring56is fitted around the rotatable cylinder52. The torsion spring56can be fixed to the movable member44at one end thereof and can be fitted into a spring hook groove57on an upper surface of the suction arm51at the other end thereof. The torsion spring56may be first fitted around the rotatable cylinder52before the movable member44is mounted.

The torsion spring56acts as a connector between the movable member44and the suction member50. Thereby, the suction member50is allowed to be rotated when the movable member44is rotated by the operation of a driving unit70that will be described below, and be relatively rotated within a range of elastic deformation when the suction arm51collides with an obstacle during cleaning. In other words, as illustrated inFIG. 2, when the suction arm51collides with an obstacle while the main body10is traveling with the suction arm51unfolded, the suction arm51can be folded toward the main body10. After passing through the obstacle, the suction arm51is again unfolded by elasticity of the torsion spring56.

The driving unit70includes a rotor71fitted on an outer surface of the movable member44, a driving motor72fixed to the upper supporting bracket41, a driving gear73coupled to a shaft72aof the driving motor72to transmit a rotating force of the driving motor72to the rotor71, and a driven gear74formed on an outer surface of the rotor71to be engaged with the driving gear73.

The rotor71has a cylindrical shape to be able to move up and down the movable member44fitted therein, and is rotatably coupled to the upper supporting bracket41at an upper portion thereof such that the rotor itself can be restricted to upward and downward movement, and is also rotatably coupled to the lower supporting bracket42at a lower portion thereof. Further, the rotor71can be provided with long guide slots75in a vertical direction to be able to transmit the rotating force of the rotor71to the movable member44and to simultaneously move the movable member44upwards and downwards. The movable member44is provided with guide knobs45fitted into the guide slots75on the outer surface thereof, so that the cylindrical movable member44moves up and down with respect to the rotor71.

The lower supporting bracket42is provided with spiral-shaped elevation guide faces47around the rotor71such that the movable member44can move upwards and downwards by the elevation guide faces47while the movable member44is rotated by the rotor71. The elevation guide faces47support the guide knobs45that protrude outwards from the movable member44through the guide slots75. Further, the guide knobs45are provided with rollers46to roll along the elevation guide faces47, respectively. Thereby, when the rotor71is rotated by an operation of the driving motor72, the suction arm51can be unfolded from the main body10while the suction member50is rotating together with the movable member44. While the above operations are occurring, the guide knobs45can simultaneously move downwards along the elevation guide faces47, thereby allowing the movable member44and the suction member50to move downwards.

Further, the lower supporting bracket42is provided with a rotation guide face48, which extends from a lower end of each elevation guide face47in a same direction (i.e., a horizontal direction) as the rotating direction of the suction member50, such that the guide knobs45which move downwards along the elevation guide faces47can be rotated within a predetermined central angle with no change in height. Thus, as illustrated inFIG. 8, the suction member50can be unfolded while rotating in a counterclockwise direction without additional downward movement after moving downwards to approach a surface to be cleaned.

As illustrated inFIGS. 3 and 4, spaces extending upwards from the elevation guide faces47and the rotation guide faces48serve as open spaces to allow the guide knobs45to move upwards and downwards. The rotor71is provided therein with a coil spring49pressing the movable member44in a downward direction. This allows the suction member50to move upwards and downwards without rotation depending on a change of a height of the floor to be cleaned while the cleaning robot travels on an uneven floor, and thus to accommodate the height change of the uneven floor. Accordingly, the guide knobs45can move upwards along the guide slots75of the rotor71together with the movable member44, thereby separating from the rotation guide face48. Thus, when the cleaning robot travels on the uneven floor, which can include a carpet, etc., the lower surface of the suction arm51can be in close vicinity to the uneven floor, and simultaneously the suction arm51can be maintained in a completely unfolded state.

As illustrated inFIGS. 3 and 5, the rotatable cylinder52of the suction member50extends beyond the rotor71. The rotatable cylinder52is connected, at the upper portion thereof, with the suction guide pipe23of the dust collecting unit20by means of a connecting pipe80. Thus, when the dust collecting unit20is actuated, air and foreign materials can be drawn through the suction port53of the suction member50.

An operation of the corner cleaning unit of the cleaning robot will be described below.

When the corner cleaning unit40is not used, the roller46of the guide knobs45are located on the elevation guide faces47, as illustrated inFIGS. 3 and 7. Thus, the movable member44is in a raised state, and the suction member50is also in a raised state. The suction arm51is also folded toward the main body10.

As illustrated inFIGS. 2 and 6, when the cleaning robot travels toward a wall100and cleans a corner adjacent to the wall100, the suction arm51of the suction member50is unfolded from the main body10by an operation of the driving motor72. Accordingly, the rotating force of the driving motor72is transmitted to the rotor71through the driving gear73and the driven gear74. The rotating force of the rotor71is transmitted to the movable member44through the guide knobs45, and the rotating force of the movable member44is transmitted to the suction member50through the torsion spring56. As illustrated inFIGS. 6 and 8, when the driving motor72is driven, the suction arm51of the suction member50is unfolded from the main body10while rotating in a counterclockwise direction, the guide knobs45of the movable member44move downwards along the elevation guide faces47, and the suction port53of the suction member50is lowered to be adjacent to the floor to be cleaned.

Further, after the suction member50is lowered to be adjacent to the floor to be cleaned and when the driving motor72is additionally driven, the guide knobs45are guided along the rotation guide face48. At this time, the suction member50is no longer rotated, and the suction arm51is unfolded while rotating at a predetermined central angle. After the suction member50is completely unfolded, the driving motor72is stopped. In this state, the cleaning robot can travel along the wall100and clean the corner, as illustrated inFIG. 2. Since the space above the rotation guide face48is an open space in which the guide knob45is freely movable upward, it is possible that suction member50moves up according to a height of the uneven floor surface.

When the suction arm51of the suction member50collides with an obstacle while the cleaning robot is traveling, the suction arm51is pushed backwards from the obstacle, and is rotated toward the main body10, so that it can pass by the obstacle. At this time, the movable member44is not rotated, but only the suction member50is rotated according to the rotation guide face48and the torsion spring56. After passing by the obstacle, the suction member50is restored to an original position by means of the elasticity of the torsion spring56. Further, because the suction member50is rotated without upward and downward movement by means of the collision with the obstacle, the suction member50maintains a fixed interval with respect to the floor to be cleaned. As a result, a cleaning effect can be increased.

When the cleaning robot travels on the uneven floor, the lower surface of the suction member50can be pushed upwards in close vicinity to the floor to be cleaned. In this case, because the guide knobs45can move upwards and downwards in the open space above the elevation guide faces47and the rotation guide faces48, the suction member50can move upwards and downwards in response to the height change of the uneven floor. In other words, because the movable member44can move upwards and downwards without rotation of the suction member50, the cleaning can be carried out with the suction member50unfolded completely.

When the cleaning of the corner is completed, the driving motor72is reversely driven, and thereby the suction arm51of the suction member50can be folded toward the main body10. At this time, because the guide knobs45moves upwards along the elevation guide faces47, the suction member50can move upwards.

As described above, according to a cleaning robot of the present general inventive concept, because a suction member of a corner cleaning unit is rotatably coupled to a movable member through the torsion spring, the suction member can be prevented from moving upwards although the suction arm of the suction member is rotated by a collision with an obstacle. Therefore, a cleaning effect can be increased.

Further, the suction member and the movable member can move upwards without rotation. As such, although a lower surface of the suction member may be pushed upwards in close vicinity to an uneven floor to be cleaned while the cleaning robot is traveling on the uneven floor like a carpet, this change in height can be accommodated, and the cleaning can be carried out while the suction member is unfolded completely in close vicinity to the uneven floor.

Further, because the suction member is rotated during operation of the driving motor, the suction member can be automatically folded and unfolded.