EP1897479A2

EP1897479A2 - Method of controlling vacuum cleaner

Info

Publication number: EP1897479A2
Application number: EP07101390A
Authority: EP
Inventors: Gun Ho Ha; Jin Wook Seo; Chang Ho Yun; Jin Young Kim; Chang Hoon Lee; Yun Hee Park
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2006-09-06
Filing date: 2007-01-30
Publication date: 2008-03-12
Anticipated expiration: 2027-01-30
Also published as: AU2007200408A1; KR20080022468A; CN101138478B; KR100876694B1; JP4705052B2; CN101138478A; JP2008062017A; RU2346643C2; EP1897479A3; RU2007103560A; EP1897479B1; AU2007200408B2

Abstract

There is provided a method of controlling a vacuum cleaner having a dust collection unit in which dusts separated from air sucked by a suction motor are stored. The method includes operating the suction motor with a first driving force, determining an amount of the dusts stored in the dust collection unit, and operating the suction motor with a second driving force greater than the first driving force as the amount of the dusts increases.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a vacuum cleaner control method, and more particularly, to a vacuum cleaner control method that can allow the vacuum cleaner to suck dusts with a uniform suction by varying a driving force of the suction motor in accordance with an amount of the dusts stored in a dust collection unit.

Description of the Related Art

Generally, a vacuum cleaner is a device that can suck air containing dusts using vacuum pressure generated by a suction motor mounted in a main body and filter off the dusts in a main body.
The vacuum cleaner is classified into a canister type and an upright type. The canister type vacuum cleaner includes a main body and a suction nozzle connected to the main body by a connection pipe. The upright type vacuum cleaner includes a main body and a suction nozzle integrally formed with the main body.
Meanwhile, a dust collection unit mounted in a cyclone type vacuum cleaner separates dusts from air using a cyclone principle and the air whose dusts are removed is discharged out of the main body.
In more detail, the cyclone dust collection unit includes a dust collection body, an air inlet through which the air is sucked into the dust collection body, a cyclone unit for separating dusts from the air sucked into the dust collection body, a dust storing unit for storing the separated dusts, and an air outlet through which the air whose dusts are filtered off in the cyclone unit is discharged.
Meanwhile, the dusts stored in a lower space of the dust collection body, i.e., in the dust storing unit, rotates along an inner circumference of the dust collection body by a rotational current generated in the dust collection body during the operation of the vacuum cleaner.
Furthermore, when the vacuum cleaner is turned off, the dusts are settled down in a low-density state.
In the conventional vacuum cleaner, even when the suction motor is driven with a uniform driving force, the suction force of the vacuum cleaner is reduced as an amount of the dusts sucked into the dust collection unit increases.
That is, when the vacuum cleaner is turned on, the suction motor is driven with a uniform driving force (e.g., 100kW).
At this point, as an amount of the dusts collected in the dust collection unit increases, the suction efficiency (suction force) of the vacuum cleaner is reduced,
Accordingly, in order to improve the reliability of the vacuum cleaner, an effort to uniformly maintain a suction force of the vacuum cleaner has been endeavored.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a vacuum cleaner control method that substantially obviates one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a vacuum cleaner control method that can uniformly maintain suction efficiency of the vacuum cleaner even when an amount of dusts collected in the dust collection unit increases.
Another object of the present invention is to provide a vacuum cleaner control method that can vary a driving force of a suction motor in accordance with a variation of an amount of dusts.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a method of controlling a vacuum cleaner having a dust collection unit in which dusts separated from air sucked by a suction motor are stored, the method including: operating the suction motor with a first driving force; determining an amount of the dusts stored in the dust collection unit; and operating the suction motor with a second driving force greater than the first driving force as the amount of the dusts increases.
In another aspect of the present invention, there is provided a method of controlling a vacuum cleaner having a dust collection unit in which dusts separated from air sucked by a suction motor is stored, the method including: operating the suction motor; determining an amount of the dusts stored in the dust collection unit; and stopping the operation of the suction motor when the amount of the dusts is greater than a reference amount.
According to the above-described present invention, since the dusts stored in the dust collection unit is compressed by a pair of the pressing members and thus the volume thereof can be minimized, the dust collection capacity in the dust collection unit can be maximized.
In addition, since the dust collection capacity is maximized, there is no need for the user to frequently empty the dust collection unit.
Since the compression state of the dusts in the dust collection unit can be maintained even when the operation of the vacuum cleaner is stopped, the dusts stored in the dust collection unit can be easily discharged during empting the dust collection unit.
Since the dust discharge request is displayed when the predetermined amount or more of the dusts are collected in the dust collection unit, the user can easily know the dust collection unit empty timing.
Furthermore, since the driving force of the suction motor varies in accordance with a variation of an amount of dusts collected in the dust collection unit, the vacuum cleaner has a uniform suction force.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:
Fig. 1 is a perspective view of a dust collection unit of a vacuum cleaner according to an embodiment of the present invention, when the dust collection unit is separated from the vacuum cleaner;
Fig. 2 is a perspective view of a dust collection mounting portion and a dust collection unit of the vacuum cleaner of Fig. 1, when the dust collection unit is separated from the dust collection unit mounting portion;
Fig. 3 is a partially-cutaway perspective view of the dust collection unit;
Fig. 4 is an enlarged view of a portion A in Fig. 3;
Fig. 5 is a perspective view illustrating a coupling arrangement between a dust collection unit and a driving unit provided to compress the dusts stored in the dust collection unit;
Fig. 6 is a perspective view of a dust separating unit and a dust collection container of the dust collection unit;
Fig. 7 is a lower perspective view of Fig. 6;
Figs. 8 and 9 is a flowchart illustrating a compression process of dusts in the dust collection unit;
Fig. 10 is a top view illustrating an operation state of a first pressing member when a dust discharge alarming is performed;
Fig. 11 a block diagram illustrating a control unit of a vacuum cleaner according to an embodiment of the present invention;
Fig. 12 is a flowchart illustrating a dust compressing process in the dust collection unit and a dust discharge alarming;
Fig. 13 is a waveform of a pulse signal that varies in accordance with an amount of the dusts collected in the dust collection unit;
Fig. 14 is a flowchart illustrating a control method of a suction motor according to an embodiment of the present invention;
Fig. 15 is a view illustrating a relationship between an amount of dusts and a suction force of a suction motor according to the prior art; and
Fig. 16 is a view illustrating a relationship between an amount of dusts and a suction force of a suction motor according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
Fig. 1 is a perspective view of a dust collection unit of a vacuum cleaner according to an embodiment of the present invention, when the dust collection unit is separated from the vacuum cleaner.
Referring to Fig. 1, a vacuum cleaner includes a main body 100 in which a suction for generation unit for generating vacuum pressure in the vacuum cleaner is provided and a dust collection unit 200 for separating the dusts in air and storing the same.
The vacuum cleaner includes a suction nozzle 20 sucking the air containing the dusts, a handle 40 allowing the user to manipulate the operation of the vacuum cleaner, an extension pipe 30 connecting the suction nozzle 20 to the handle 40, and a connection hose 50 connecting the suction nozzle 20 to the main body 100.
In this embodiment, the suction nozzle 20, the extension 30, the handle 40, and the connection hose 50 are well known in the art, the detailed description thereof will be omitted herein.
In this embodiment, the suction nozzle and the extension pipe are well known in the art, the detailed description thereof will be omitted herein.
A main body suction portion 110 through which the air containing the dusts are sucked through a suction nozzle 20 is formed at a front-lower end of the main body 100.
A main body discharge portion 120 through which the air whose dusts are separated is formed at a side of the main body. The dust collection unit 200 includes a dust separation portion 210 for separating the dusts from the air and a dust collection container 220 for storing the dusts separated from the dusts.
Here, the dust separation unit 210 includes a cyclone unit 211 that separate the dusts from the air using a cyclone theory, i.e., a centrifugal force difference. Therefore, the dusts separated by the cyclone unit 211 are stored in the dust collection container 220.
Meanwhile, it is preferable that the dust collection unit 200 is designed to maximize the dust collection capacity of the dusts stored therein. Therefore, the dust collection unit 200 is preferably provided with additional unit for minimizing the volume of the dusts stored in the dust collection container 220.
The following will describe the dust collection unit that is maximized in the dust collection capacity according to the present invention with reference to Figs. 2 and 5.
Fig. 2 is a perspective view of a dust collection mounting portion and a dust collection unit of the vacuum cleaner of Fig. 1, when the dust collection unit is separated from the dust collection unit mounting portion, Fig. 3 is a partially-cutaway perspective view of the dust collection unit, Fig. 4 is an enlarged view of a portion A in Fig. 3, and Fig. 5 is a perspective view illustrating a coupling arrangement between a dust collection unit and a driving unit provided to compress the dusts stored in the dust collection unit;
Referring to Figs. 2 and 5, the dust collection unit 200 is detachably mounted on the main body 100.
The main body 100 is provided with a dust collection unit mounting portion 130 on which the dust collection unit 200 is mounted.
A pair of pressing members 310 and 320 are provided in the dust collection unit 200 to reduce the volume of the dusts stored in the dust collection container 220, thereby increasing the dust collection capacity.
Here, the pair of pressing members 310 and 320 compress the dusts by the interaction thereof and thus reduce the volume of the dusts. Therefore, the density of the dusts stored in the dust collection container 220 decreases and thus the maximum dust collection capacity of the dust collection container 220 increases.
For descriptive convenience, the pair of the pressing members 310 and 320 are respectively referred as first and second pressing members 310 and 320.
In this embodiment, at least one of the first and second pressing members 310 and 320 is movably provided in the dust collection container 220 so that the dusts are effectively compressed by the pressing members 310 and 320.
That is, when the first and second pressing members 310 and 320 are rotatably provided in the dust collection container 220, the first and second pressing members 310 and 320 rotate and move toward each other so that a gap between the first and second plates 310 and 320 is reduced and thus the dusts between the first and second plates 310 and 320 are compressed.
In this embodiment, the first pressing member 310 is rotatably provided in the dust collection container 220 and the second pressing member 220 is fixed in the dust collection container 220.
Accordingly, the first pressing member 310 becomes a rotational plate and the second pressing member 310 becomes a stationary plate.
Meanwhile, the dust collection container 320 is provided with a dust storing portion 221 defining a space on which the dusts are stored. The dust storing unit 221 is formed surrounding a rotational locus of a free end 311 of the first pressing member 310.
That is, the second pressing member 320 may be provided between an axis of the rotational shaft 312, which is a rotational center of the first pressing member 310, and an inner circumference of the dust storing portion 221.
That is, the second pressing member 320 is provided on a plan connecting the axis of the rotational shaft 312 to the inner circumference of the dust storing portion 221. At this point, the second pressing member 320 shields partly or completely the space defined between the inner circumference of the dust storing portion 221 and the axis of the rotational shaft 312 so that the dusts are pushed and compressed against the first pressing member 310.
A first end 321 of the second pressing member 320 is integrally formed on the inner circumference of the dust storing portion 221 and a second end of the second pressing member 320 is integrally formed on the fixing shaft 322 provided on a common axis with the rotational shaft 312 of the first pressing member 310.
Alternatively, only the first end of the second pressing member 320 is integrally formed on the inner circumference of the dust storing portion 221 or only the second end of the second pressing member is integrally formed on the fixing shaft 322. That is, the second pressing member 320 is fixed on at least one of the inner circumference of the dust storing portion 221 and the fixing shaft 322.
However, even when the first end of the second pressing member 320 is not integrally formed on the inner circumference of the dust storing portion 221, it is preferably that the first end of the second pressing member 320 is positioned near the inner circumference of the dust storing portion 221.
Furthermore, even when the second end of the second pressing member 320 is not integrally connected to the fixing shaft 322, it is preferable that the second end of the second pressing member 320 is positioned near the fixing shaft 322.
The reason for positioning the second pressing member 320 is to prevent the dusts rushing in by the first pressing member 310 from leaking through a gap formed in a side direction of the second pressing member 320.
The first and second pressing members 310 and 320 are formed of rectangular plates. The rotational shaft 312 of the first pressing member 310 may be provided on a common axis with the axis defining the center of the dust storing portion 221.
Meanwhile, the fixing shaft 322 protrudes inward from an end of the dust storing portion 221. The fixing shaft 322 is provided with a hollow portion extending in the axial direction. The rotational shaft 312 is assembled in the hollow portion. That is, a portion of the rotational shaft 312 is inserted downward into the hollow portion of the fixing shaft 322.
With the above-described structure, the vacuum cleaner of this embodiment further includes a driving unit 400 connected to a rotational shaft 312 of the first pressing member 310 and rotating the first pressing member 310.
The following will describe the dust collection unit 200 and the driving unit 400 with reference to Figs. 4 and 5.
The driving unit 400 includes a compression motor 430 generating driving power, and power transmission units 410 and 420 rotating the first pressing member 310 by transmitting the driving power of the compression motor 430 to the first pressing member 310. A micros switch 440 that is turned on/off in response to rotation of the driving gear 420 is provided under the dust collection unit mounting portion 130.
That is, the power transmission units 410 and 420 includes a driven gear 410 coupled to the rotational shaft 312 of the first pressing member 310 and a driving gear 420 transmitting power to the driven gear 410.
The driving gear 420 is coupled to the rotational shaft 870 of the compression motor 430 to rotate by the compression motor 430.
Therefore, when the compression motor 430 rotates, the driving gear 420 coupled to the compression motor 430 rotates. The rotational force of the compression motor 430 is transmitted to the driven gear 410 and thus to the first plate 310, thereby rotating the first pressing member 310.
A plurality of gear teeth 422 are formed along an outer circumference of the driving gear 420 at predetermined intervals. In the following description, portions where the gear teeth 422 are formed will be referred as "top lands" and portions where the gear teeth 422 are not formed will be referred as "bottom-lands."
A terminal extending from a side of the micro switch 440 is positioned corresponding to a lower portion of each of the top-lands of the driving gear 420.
Therefore, the terminal extending from the micro switch 440 periodically detects the top-lands and bottom-lands as the driving gear 420 rotates.
When the terminal is positioned at the top-land, the micro switch 440 is turned on. When the terminal is positioned at the bottom-land, the micro switch 440 is turned off. The on-off signal of the micro switch is applied to a counter 880 so that a predetermined pulse signal is output. That is, the counter 880 outputs a high level pulse signal when the micro switch 440 is turned on and outputs a low level pulse signal when the micro switch 440 is turned off.
Therefore, by measuring the number of pulses (i.e., a switch on-off period), the degree of the rotation of the driving gear 420 can be measured.
Meanwhile, the compression motor 430 is provided at a lower portion of the dust collection unit mounting portion 130 and the driving gear 420 is coupled to the rotational shaft of the compression motor 430 and provided on a bottom of the dust collection unit mounting portion 130.
A portion of the outer circumference of the driving gear 420 is exposed at the bottom of the dust collection unit mounting portion 130.
Therefore, it is preferable that a motor receiving portion (not shown) in which the compression motor 430 is installed is provided under the bottom of the dust collection unit mounting portion 130. The dust collection unit mounting portion 130 is provided at an approximately-center of the bottom with an opening 131 through which a portion of the outer circumference of the driving gear 420 is exposed.
Meanwhile, the rotational shaft 312 of the first pressing member 310 is inserted downward into the hollow portion of the fixing shaft 322 and the driven gear 410 is inserted upward into the hollow portion of the fixing shaft 322, thereby being coupled to the rotational shaft 312.
The rotational shaft 312 is provided with a stepped portion 312c supported on the upper end of the fixing shaft 322. The rotational shaft 312 is divided into upper and lower shafts 312a and 312b with reference to the stepped portion 312c. The upper shaft 312a is coupled to the first pressing member 310 and the lower shaft 312b is coupled to the driven gear 410.
Here, in order to allow the lower shaft 312b to be coupled to the driven gear 410, the lower shaft 312b is provided with a groove 312d in which a gear shaft of the driven gear 410 is inserted.
Here, the groove 312d may be formed in a variety of shapes such as circle, square and the like. The gear shaft of the driven gear 410 is formed in a shape corresponding to the groove 312d.
Therefore, when the driven gear 410 is coupled to the rotational shaft 312, the driven gear 410 is exposed out of the dust collection container 220.
As the driven gear 410 is exposed to an external side of the dust collection container 220, the driven gear 410 is engaged with the driving gear 420 when the dust collection unit mounting portion 130 is mounted on the dust collection unit 200.
Meanwhile, the compression motor 430 may be a reversible motor.
That is, the compression motor 430 may be a synchronous motor (since the synchronous motor is well known in the art, the detailed description thereof will be omitted herein. The feature that the reversible motor 430 is the synchronous motor is one of the sprit of the present invention).
At this point, the direction conversion point of time of the compression motor 430 is set by determining a point of time when the driving gear 420 cannot rotate at the predetermined period by the first pressing member 310 that cannot rotate by the dusts.
That is, the compression motor 420 stops temporarily with reference to a point of time where the micro switch 440 detects a point of time where the driving gear 420 cannot rotate no longer due to the dusts and then the compression motor 430 rotates in a reverse direction.
When the first pressing member 310 reaches a peak point where it cannot rotate by the compressed dusts, it is preferable that the first pressing member 31 keeps pressing the dusts for a predetermined time.
When the first pressing member 310 stops rotating in a first direction, the power rotating the first pressing member 310, i.e., electric power applied to the compression motor 430 is cut off for a predetermined time so that the first pressing member 310 keeps the pressing state of the dusts. When the predetermined time passes, the electric power is applied again to the compression motor 430 so that the first pressing member 31 moves.
When a predetermined amount or more of the dusts are collected in the dust collection container 220, indications 510 and 520 for allowing the user to empty the dust collection container 220 is displayed in order to prevent the deterioration of the dust collection performance and the overload of the motor.
To realize this, the indicators 510 and 520 are provided on the main body 100 or the handle 40. When the predetermined amount or more of the dusts are collected in the dust collection container 220 and thus the rotational range of the first pressing member 310 becomes a predetermined angle or less, the indication for letting the user to know the empty timing is displayed on the indicator.
To realize this, indicators 510 and 520 are provided on the main body 100 or the handle 40. When the predetermined amount or more of the dusts are collected in the dust collection container 220 and thus the rotational range of the first pressing member 310 is a predetermined level or less. The indication for allowing the user to empty the dust collection container 220 is transmitted to the user through the indicators 510 and 520.
The indicator may be a light emitting diode (LED) 510 for visually letting the user know that it is time to empty the dust collection container. Alternatively, the indicator may be a speaker 520 for aurally letting the user know when it is time to empty the dust collection container.
The LED 510 and the speaker 520 may be simultaneously applied so that the indication for allowing the user to empty the dust collection container 220 can be more effectively transmitted to the user. In this case, the LED 510 may be provided on the handle 40 while the speaker 520 may be provided any one of the main body 100 and the handle 40.
Fig. 6 is a perspective view of the dust separating unit and dust collection container of the dust collection unit and Fig. 7 is a bottom perspective view of Fig. 6.
Referring to Figs. 6 and 7, the dust separation unit 210 is coupled to an upper portion of the dust collection container 220 and thus the dusts are separated in the dust separation unit 210 are directed downward and stored in the dust collection container 220.
The dust separation unit 210 is provided at an outer circumference with an air inlet 211a formed on a normal direction of the dust separation portion 210. A cover 221d is detachably provided on a top of the dust separation unit 210.
The cover 211d is provided at a center with an air outlet 211b through which the air whose dusts are separated by the cyclone unit 211 in the separation unit 210.
A hollow air exhaust member 211c is coupled to the air outlet 211b and the hollow air exhaust member 211c is provided at a circumference with a plurality of through holes for exhausting the air directed from the cyclone unit 211.
A partition plate 230 is formed at a lower portion of the dust separation unit 210. The partition plate 230 functions to divide the dust separation unit 210 and the dust collection unit 220. The partition plate 230 prevents the dusts from flying into the dust collection container 220 in a state where the dust separation unit 210 is coupled to the dust collection container 220.
The partition plate 230 is provided with a dust discharge hole 231 for discharging the dusts from the cyclone unit 211 to the dust separation unit 210.
At this point, the dust discharge hole 231 may be formed at an opposite side of the second pressing member 320.
The reason for forming the dust discharge holes 231 at the opposite side of the second pressing member 320 is to maximize an amount of the dusts compressed by the opposite sides of the second pressing member 320 to maximize the dust collection capacity and to prevent the dusts from flying during the collection of the dusts.
As described above, the dust separation unit 210 and the dust collection container 220 are respectively provided with upper and lower handles 212 and 223.
The dust collection unit 200 is provided with a hook device so that the dust collection container 220 can be coupled to the dust separation unit 210 in a state where the dust collection container 220 is mounted on the dust separation unit 210.
That is, a hook receiver 241 is provided on the lower end of the dust separation unit 210 and a hook 242 hooked on the receiver 241 is formed on an upper end of the outer circumference of the dust collection container 220.
Meanwhile, when the cyclone unit 211 is referred as a main cyclone unit and the dust storing unit 221 is referred as a main storing unit, the dust collection unit 200 may further includes at least one sub-cyclone unit provided on the main body and a sub-storing unit 224 provided on the dust collection unit 200.
Here, the sub-storing unit 224 functions to secondarily separate the dusts contained in the air exhausted from the main cyclone 211 and the sub-storing unit 224 functions to store the dusts separated by the sub-cyclone unit.
The sub-storing unit 224 is provided on an outer circumference of the dust collection unit 200 in a state where an upper end thereof is opened.
In this embodiment, the sub-storing unit 224 is provided on the outer circumference of the dust collection container 220 and a sub-dust inlet portion 213a communicating with the sub-storing unit 224 is provided on the circumference of the dust separation portion 210.
Here, a sub-dust inlet portion 213a selectively communicating with the dust discharge hole 141 of the sub-cyclone unit 140 is formed on an outer wall of the sub-dust inlet portion 213. A bottom of the sub-dust inlet portion 213a is opened to communicate with the sub-storing unit 224.
Accordingly, when the main cyclone unit 211 is mounted on the main body 100, the sub-dust inlet hole 213a is connected to the dust discharge hole 140 of the sub-cyclone unit. When the dust collection container 220 is mounted on the main body 100 under the main cyclone unit 211, the sub-dust inlet portion 213 communicates with the sub-storing portion 224.
Therefore, the dusts separated in the sub-cyclone unit are stored in the sub-storing unit 224 through the sub-dust inlet portion 213a.
The following will describe the operation of the vacuum cleaner of the embodiment.
First, when power is applied to the vacuum cleaner and the air containing the dusts is sucked into the suction nozzle 40 by the vacuum pressure generated by the suction force generating unit.
The air directed into the suction nozzle 40 is introduced into the main cyclone unit through the air inlet 211a via the main body suction unit 110. The air introduced into the main cyclone unit is guided in a tangential direction of the inner wall of the main cyclone unit 211 to create spiral current. Therefore, the dusts contained in the air are separated from the air by a centrifugal difference between them.
The dusts spirally moving downward along the inner wall of the main cyclone unit 211 are stored in the main storing unit 221 after passing through the dust discharge hole 231 of the partition plate 230.
The air whose dusts are primarily separated by the main cyclone unit 211 is exhausted through the air outlet 211b via the air exhaust member 211c and then directed into the sub-cyclone unit.
Accordingly, the dusts separated in the sub-cyclone unit are stored in the sub-storing unit 224 and the dusts separated in the sub-cyclone unit are discharged from the sub-cyclone unit. Then, the dusts are introduced into the main body 100 and discharged from the main body through the main body discharge unit 120.
Meanwhile, most of the dusts introduced into the vacuum cleaner are stored in the main storing unit 221 during cleaning. The dusts stored in the main storing unit 221 are compressed by the first and second pressing members 310 and 320 to a minimum volume. Therefore, a large amount of dusts can be stored in the main storing unit 221.
Since the operation and interaction of the first and second pressing members 310 and 320 are already described, a detailed description thereof will be omitted herein.
When a predetermined amount or more of the dusts is stored in the dust collection container 220, the indicators 510 and 520 operate so that the user knows the fact that the dust collection container 220 must be empted.
Then, the user separates the dust collection unit 200 from the main body 100 and empties the same.
Figs. 8 and 9 are top views of the dust collection container, illustrating a compression process of the dusts in the dust collection unit and Fig. 10 is a top view illustrating an operation state of the first pressing member during a dust discharge indication is performed.
Fig. 8 illustrates a dust compressing state of the first pressing member 310 rotating counterclockwise. Fig. 8 illustrates a dust compressing state of the first pressing member 310 rotating clockwise. Fig. 10 shows that a large amount of dusts are filled in the dust collection container 220 at left and right spaces with reference to the second pressing member 320 by repeating the operations of Figs. 8 and 9.
The following will describe a method for controlling the indication of the dust discharge timing and the compression of the dusts collected in the dust collection container 220.
Fig. 11 a block diagram illustrating a control unit of the vacuum cleaner according to an embodiment of the present invention, Fig. 12 is a flowchart illustrating the dust compression process in the dust collection unit and the dust discharge request indication, and Fig. 13 is a waveform of a pulse signal varying according to an amount of the dusts collected in the dust collection unit.
Referring first to Fig. 11, the vacuum cleaner of this embodiment includes a control unit 810 formed of a microcomputer, an operation signal input unit 820 for selecting a suction power of the dusts (e.g., high, middle, low power modes), a dust discharge signal display unit 830 formed of a light emitting device, a suction motor driver 840 for operating the suction motor 850 that is a driving motor for sucking the dusts into the dust collection unit according to the operation mode, a compression motor driver 860 for operating the compression motor 430 used for compressing the dusts collected in the dust collection unit, and a counter unit 880 for measuring a degree of the rotation clockwise and counterclockwise (e.g., reciprocal rotation time) of the compression motor 430.
In operation, when the user selects one of the high, middle and low modes representing the suction power using the operation signal input unit 820, the control unit 810 controls the suction motor driver 840 so that the suction motor 850 can be operated with the suction power corresponding to the selected power mode. That is, the suction motor driver 840 operates the suction motor 850 with the suction power according to a signal transmitted from the control unit 810.
Meanwhile, the control unit 810 operates the compression motor 430 simultaneously with or right after the operation of the suction motor driver 840.
When the suction motor 850 operates, the dusts starts being sucked into the dust collection unit through the suction nozzle 20. The dusts introduced into the dust collection unit are compressed by the first compressing member 310 rotating clockwise and counterclockwise by the compression motor 430.
The counter unit 880 measures the reciprocal time (period) of the compression motor 430 and transmits the corresponding signal to the control unit 810.
As an amount of the dusts compressed in the dust collection unit increases, the reciprocal rotation time of the compression motor is reduced. When the amount of the dusts reaches to a predetermined level and thus the reciprocal rotation time is less than a predetermined time, the control unit 810 displays an empty request signal through the indicator 830.
Then, the user is notified from the indicator 830 that the dust collection unit must be empted.
Fig. 12 is a flowchart illustrating a method of controlling the vacuum cleaner. That is, Fig. 12 shows the operation concept of the block diagram of Fig. 11 in more detail.
First, the user operates the vacuum cleaner by selecting one of the high, middle and low modes of the operation signal input unit 820. The control unit 810 controls the suction motor driver 840 so that the suction motor 850 can be operated with the suction power corresponding to the selected power mode (S110).
When the suction motor 850 operates, the dusts starts being sucked into the dust collection unit through the suction nozzle 20. The sucked dusts are collected in the dust collection unit, i.e., in the dust collection container 220.
As described above, the dusts collected in the dust collection container 220 are compressed by the pressing members 310 and 320.
Therefore, the control unit 810 drives the compression motor 430 to compress the dusts sucked in the dust collection container (S120).
Here, although the compression motor 430 is driven after the suction motor 850 is driven, the suction and compression motors 850 and 870 may be simultaneously operated.
In step S120, when the compression motor 430 is driven, the driving gear 420 coupled to the rotational shaft of the compression motor 430 rotates. When the driving gear 410 rotates, the driven gear 410 starts rotating. When the driven gear 410 rotates, the rotational shaft 312 coupled to the driven gear 410 and the first pressing member 310 rotate toward the second pressing member 320 to compress the dusts.
During the rotation of the driving gear 420, the terminal of the micro switch 440 is periodically turned on/off. The counter 880 receives the on-off signal of the micro switch to output a pulse signal corresponding to the received on-off signal to the control unit 810.
That is, as an amount of the dusts compressed by the first and second pressing members 310 and 320 increases, the reciprocal rotation time of the driven gear 410 is reduced and thus the reciprocal rotation time of the driving gear 420 engaged with the driven gear 410 is also reduced.
At this point, the reduction of the reciprocal rotation time of the driving gear 420 means that the number of on-off operations of the micro switch M is reduced. That is, the number of the pulse signals output from the counter unit 880 is reduced.
Here, the output of the pulse signals will be described hereinafter with reference to Fig. 13.
When the first pressing member 310 compresses the dusts while moving toward the second pressing member 320, the driven and driving gears 410 and 420 rotate with a predetermined period and thus the micro switch 440 is turned on and off with a predetermined period according to the rotation of the driving gear 420.
However, when the first pressing member 310 cannot rotate toward the second pressing member 320 as the dusts are fully compressed, the driven and driving gears 410 and 420 do not rotate any more. This means that no pulse signal is generated. Therefore, the control unit determines that the dusts are fully compressed by the rotation of the first pressing member 310. This determining process is done with reference to whether the pulse signal is regularly generated.
That is, the control unit determines if the regular pulses are generated from the counter unit 880.
When the regular pulses are generated, this means that there is still a space for compressing the dusts between the first and second pressing members 310 and 320. In this case, the process is returned to the step 120 to continue the compression process.
On this other hand, when no regular pulse is generated, i.e., when the dusts are fully compressed by the first pressing member 310, the control unit 810 stops the operation of the compression motor 430.
That is, during the application of the periodical pulses through the counter unit 880, when the regular periodical pulses are collapsed, the control unit 810 detects this and stops the compression motor 430 using the compression motor driver 860. Therefore, the rotation of the first pressing member 310 is stopped.
Next, the control unit 870 maintains the stopped state of the compression motor 430 for a predetermined time (e.g., 3 seconds). This predetermined time is a stand by time for driving the compression motor 430 in a reverse direction and is a time for keeping a dust compression state by the stopped first pressing member 310.
Next, the control unit 810 determines if the number N of the pulses from the former compression motor stop point (time T1) to the current compression motor stop point (time T2) is less than a reference number. For example, when an amount of the dusts is greater than a reference amount, the reciprocal time of the first pressing member 310 is reduced in response to the reduction of the number of the pulses output from the counter unit 880 during the period.
That is, the determination if the amount of the dusts compressed in the dust collection container 220 is higher than the reference amount is done by measuring the reciprocal time of the first pressing member (the number of the pulses generated from the counter unit 880).
In the step S170, it is determined that the number N of the pulses from the former compression motor stop point (time T1) to the current compression motor stop point (time T2) is greater than the reference number, it means that there is still a space for further compressing the dusts in the dust collection container. Therefore, the process is returned to the step S120. At this point, the compression motor 430 is controlled by the control unit 810 such that it rotates in a direction opposite to that of step S150.
On the other hand, in the step S170, it is determined that the number N of the pulses from the former compression motor stop point (time T1) to the current compression motor stop point (time T2) is less than the reference number, the control unit 810 determines if the number of the results where the number of the pulses determined in the step S170 is less than the predetermined number reaches a reference number of times (e.g., 3 times). By doing this, it is possible to more accurately determine if the amount of the dusts in the dust collection container 220 is higher than the reference amount. Furthermore, an error that may occur as the first pressing member 310 cannot normally rotate in both directions due to the affection of the dusts can be prevented.
In the step S180, when the number of the results is less than the reference number of times, the process is returned to the step S130.
On the other hand, in the step S180, it is determined that the results reaches the reference number of times, the control unit stops the suction motor 850 that is the main driving motor. That is, when the dust suction operation is continued even when the amount of the dusts collected in the dust collection container 220 is higher than the predetermined amount, the dust suction efficiency is deteriorated and the suction motor 850 may be overloaded. Therefore, the control unit 810 stops the operation of the suction motor 850.
Next, the control unit 810 transmits an empty request signal to a dust discharge request signal display unit 830 so that the user can concern this. As another embodiment, the dust discharge request signal may be represented by sound using a buzzer circuit.
Fig. 13 is an example of a waveform of the pulse signal that varies in accordance with the amount of the dusts collected in the dust collection unit.
That is, Fig. 13a shows a case where few dusts are in the dust collection container 220. Fig. 13b shows a case where the dusts are being filled in the dust collection container 220, and Fig. 13c shows a case where the amount of the dusts reaches the reference amount.
Referring to Fig. 13, the pulse waveform is a signal that is output from the counter unit 880 and input to the control unit 810. The pulse signal is output from the counter unit 880 receiving a signal of the micro switch 440 that is turned on and off according to the rotation of the driving gear 420.
First, when the compression motor 430 drives, the first pressing member 310 will be positioned at a certain location. Therefore, for example, the control unit starts normally operating from a point A where the compression motor 430 rotates counterclockwise and initially stops (here, a section a-b is 3 seconds). That is, after reaching the point A, the control unit determines that the pulse signals input from the counter unit 880 are the normal pulse signals.
As can be noted from Fig. 13, when the amount of the dusts collected in the dust collection container 220 is relatively small, the first pressing member 310 can rotate to the maximum clockwise and counterclockwise and thus 10 pulses will be output as shown in Fig. 13a.
When the amount of the dusts increases as the time goes, the reciprocal rotation time of the first pressing member will be gradually reduced (i.e., the rotational angle of the first pressing member 310 will be reduced).
As shown in Fig. 13c, when the number of the pulse signals is three and the generation of these pulse signals is repeated by a reference number of times (3 times in this embodiment), the control unit generates an empty request signal.
The dust compression process in the dust collection unit and the empty request timing display process are controlled as described above.
The following will describe a method of controlling a driving force of the suction motor in accordance with an amount of the dusts introduced into the vacuum cleaner.
Fig. 13 is a waveform of a pulse signal which varies in accordance with an amount of the dusts collected in the dust collection unit, Fig. 14 is a flowchart illustrating a control method of a suction motor according to an embodiment of the present invention, Fig. 15 is a view illustrating a relationship between an amount of dusts and a suction force of a suction motor according to the prior art, and Fig. 16 is a view illustrating a relationship between an amount of dusts and a suction force of a suction motor according to an embodiment of the present invention.
Referring to Fig. 14, when the user turns on the vacuum cleaner (S310), a predetermined driving force (a first driving force) is generated by the suction motor 850 (S320). The first driving force is controlled by the control unit 810 during the initial operation of the vacuum cleaner. The first driving force may vary depending on a maximum driving force of the suction motor 850. For example, the first driving force may be 90% of the maximum driving force.
Next, the control unit measures an amount of dusts accumulated in the dust collection unit using the above described dust amount measuring manner (S330). That is, the control unit 810 measures the amount of the dusts accumulated in the dust collection unit with reference to the number of the pulse signals input from the counter unit 880.
When it is determined in the step 330 that the amount of the dusts is less than a reference amount (S340), the control unit 810 allows the suction motor to keep operating with the first driving force and keeps measuring the amount of the dusts stored in the dust collection unit.
On the other hand, when it is determined in the step 330 that the amount of the dusts is greater than the reference amount (S340), the control unit 810 increases the driving force of the suction motor 850 at a predetermined rate in response to the increase of the amount of the dusts. At this point, the driving force that is increasing is referred as "second driving force." Here, the second driving force may increase in proportion to the increase of the amount of the dusts. Alternatively, the second driving force may increase step by step in accordance with the amount of the dusts.
Here, it can be noted that the amount of the dusts as the driving force of the suction motor is increasing is less than that of the dusts as the suction motor stops driving in Fig. 12. Also, the determination if the amount of the dusts is greater than the reference amount can be done with reference to the number of the pulses generated from the counter unit 880.
As shown in Fig. 15, in the prior art, the driving force of the suction motor is constantly maintained regardless of the amount of the dusts stored in the dust collection unit. Therefore, when the amount of the dusts accumulated in the dust collection unit is greater than the reference amount, the actual suction force for sucking dusts from an external side is reduced.
However, when the control method according to the embodiment of the present invention is used, the suction force can be uniformly maintained regardless of the amount of the dusts collected in the dust collection unit.
According to the present invention, the suction force of the vacuum cleaner can be uniformly maintained by gradually increasing the driving force of the suction motor 850 from a point of time where the amount of the dusts sucked into the air cleaner becomes greater than the reference amount. In addition, when the number of the pulses converted in the counter unit 880 is less than a reference number, the suction motor 850 stops operating and the empty request signal is transmitted to the external side.
Although the present invention is applied to the canister type vacuum cleaner by way of example, the present invention can be also applied to an upright type vacuum cleaner as well as a robot vacuum cleaner.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

A method of controlling a vacuum cleaner having a dust collection unit in which dusts separated from air sucked by a suction motor are stored, the method comprising:
operating the suction motor with a first driving force;

determining an amount of the dusts stored in the dust collection unit; and

operating the suction motor with a second driving force greater than the first driving force as the amount of the dusts increases.
The method of claim 1, wherein the second driving force increases as the amount of the dust increases.
The method of claim 1, wherein the second driving force increases step by step in accordance with the amount of the dusts.
The method of claim 1, wherein, when the amount of the dusts is greater than a reference amount, the suction motor stops operating.
The method of claim 1, wherein, when the amount of the dusts is greater than a reference amount, a dust discharge request signal is displayed.
The method of claim 1, further comprising, at least when the suction motor operates, compressing the dusts stored in the dust collection unit using at least one pressing member.
The method of claim 1, wherein the moving time of the pressing member is continually detected and the determination of the amount of the dusts is done with reference to the moving time.
The method of claim 7, wherein the moving time is converted into a pulse signal by a counter unit.
The method of claim 7, wherein the pressing member can rotate in both directions and the rotational direction of the pressing member is determined in accordance with the moving time.
The method of claim 1, wherein the first driving force is set by a user.
A method of controlling a vacuum cleaner having a dust collection unit in which dusts separated from air sucked by a suction motor is stored, the method comprising:
operating the suction motor;

determining an amount of the dusts stored in the dust collection unit; and

stopping the operation of the suction motor when the amount of the dusts is greater than a reference amount.
The method of claim 11, wherein a driving force of the suction motor increases in response to the amount of the dusts stored in the dust collection unit.
The method of claim 12, wherein the stopping of the operation includes displaying a dust discharge request signal.
The method of claim 11, wherein the dusts stored in the dust collection unit is compressed by a pressing member rotating by a compression motor.
The method of claim 14, wherein a rotating time of the compression motor is continually detected and the determining of the amount of the dusts is done by comparing the rotating time with a reference time.
The method of claim 15, wherein the reference time includes a first reference time and a second reference time longer than the first reference time; and
the suction motor maintains an initial driving force when the reference time is equal to or longer than the first reference time.
The method of claim 16, wherein, when the reference time is between the first and second reference times, a driving force of the suction motor increases in response to the amount of the dusts and, when the reference time is less than the second reference time, the suction motor stops operating.