U.S. patent application number 13/755283 was filed with the patent office on 2013-08-08 for washing machine and control method thereof.
This patent application is currently assigned to SAMSUNG ELECTRONICS CO., LTD.. The applicant listed for this patent is SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to Jung Ran JUNG, Hyun Bae KIM, Jung Soo LIM.
Application Number | 20130198969 13/755283 |
Document ID | / |
Family ID | 47715869 |
Filed Date | 2013-08-08 |
United States Patent
Application |
20130198969 |
Kind Code |
A1 |
KIM; Hyun Bae ; et
al. |
August 8, 2013 |
WASHING MACHINE AND CONTROL METHOD THEREOF
Abstract
A washing machine includes a drum, a water supply device, and a
controller. The drum accommodates laundry, and the water supply
device supplies water to the inside of the drum. The controller
controls supply of water so that water is supplied into the drum
from when rotational speed of the drum reaches a first
predetermined speed, is decelerated and reaches a second
predetermined speed, to when the rotational speed of the drum
reaches to a third speed more than the second speed and less than
the first speed, in a spin-drying cycle.
Inventors: |
KIM; Hyun Bae; (Yongin,
KR) ; LIM; Jung Soo; (Hwaseong, KR) ; JUNG;
Jung Ran; (Suwon, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAMSUNG ELECTRONICS CO., LTD.; |
Suwon |
|
KR |
|
|
Assignee: |
SAMSUNG ELECTRONICS CO.,
LTD.
Suwon
KR
|
Family ID: |
47715869 |
Appl. No.: |
13/755283 |
Filed: |
January 31, 2013 |
Current U.S.
Class: |
8/137 ;
68/200 |
Current CPC
Class: |
D06F 23/02 20130101;
D06F 2204/086 20130101; D06F 33/00 20130101; D06F 2204/084
20130101; D06F 39/088 20130101; D06F 35/005 20130101; D06F 2202/085
20130101; D06F 2204/04 20130101; D06F 2202/065 20130101 |
Class at
Publication: |
8/137 ;
68/200 |
International
Class: |
D06F 23/02 20060101
D06F023/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 3, 2012 |
KR |
10-2012-0011215 |
Claims
1. A washing machine comprising: a drum accommodating laundry; a
water supply device supplying water to the inside of the drum; and
a controller controlling supply of water so that water is supplied
into the drum from when the rotational speed of the drum reaches a
first predetermined speed, to when the rotational speed of the drum
is decelerated, reaches a second predetermined speed and then
reaches a third speed more than the second speed and less than the
first speed, in a spin-drying cycle.
2. The washing machine according to claim 1, wherein the water
supply device includes: an injection nozzle injecting water into
the drum; and a water supply valve adjusting supply of water from
the outside of the washing machine to the injection nozzle.
3. The washing machine according to claim 2, wherein the first
speed is a rotational speed greater than the second speed, and the
second speed is a resonant speed.
4. The washing machine according to claim 3, wherein the controller
adjusts at least one of an opening and closing time and an opening
and closing degree of the water supply valve.
5. The washing machine according to claim 3, wherein the controller
stops injection of water into the drum by closing the water supply
valve if the rotational acceleration of the drum is greater than a
predetermined acceleration while the rotational speed of the drum
reaches the second speed and then reaches the third speed.
6. The washing machine according to claim 2, wherein the controller
causes water to be supplied to the inside of the drum until the
rotational speed of the drum reaches the second speed, maintains
the second speed and then reaches the third speed.
7. The washing machine according to claim 6, wherein the first
speed is a rotational speed greater than the second speed, and the
second speed is a rotational speed smaller than a resonant
speed.
8. The washing machine according to claim 7, wherein the controller
adjusts at least one of an opening and closing time and an opening
and closing degree of the water supply valve.
9. The washing machine according to claim 8, wherein the controller
stops injection of water into the drum by closing the water supply
valve if the rotational acceleration of the drum is greater than a
predetermined acceleration while the rotational speed of the drum
reaches the second speed and then reaches the third speed.
10. A control method of a washing machine comprising: injecting
water into a drum accommodating laundry using an injection nozzle
from when the rotational speed of the drum reaches a first
predetermined speed in a spin-drying cycle; and stopping injection
of water into the drum when the rotational speed of the drum is
decelerated and reaches a second predetermined speed and then the
rotational speed of the drum reaches to a third speed more than the
second speed and less than the first speed.
11. The control method according to claim 10, wherein the first
speed is a rotational speed greater than the second speed, and the
second speed is a resonant speed.
12. The control method according to claim 11, wherein the injection
of water into the drum using the injection nozzle includes
injecting water into the drum by adjusting at least one of an
opening and closing time and an opening and closing degree of a
water supply valve adjusting supply of water to the injection
nozzle.
13. The control method according to claim 11, wherein the stoppage
of injection of water into the drum includes stopping injection of
water into the drum if the rotational acceleration of the drum is
greater than a predetermined acceleration while the rotational
speed of the drum reaches the second speed and then reaches the
third speed.
14. The control method according to claim 10, wherein the stoppage
of injection of water into the drum includes stopping injection of
water into the drum when the rotational speed of the drum reaches
the second speed, maintains the second speed and then reaches the
third speed.
15. The control method according to claim 14, wherein the first
speed is a rotational speed greater than the second speed, and the
second speed is a rotational speed smaller than a resonant
speed.
16. The control method according to claim 15, wherein the injection
of water into the drum using the injection nozzle includes
injecting water into the drum by adjusting at least one of an
opening and closing time and an opening and closing degree of a
water supply valve adjusting supply of water to the injection
nozzle.
17. The control method according to claim 15, wherein the stoppage
of injection of water into the drum includes stopping injection of
water into the drum if the rotational acceleration of the drum is
greater than a predetermined acceleration while the rotational
speed of the drum reaches the second speed, maintains the second
speed and then reaches the third speed.
18. A control method of a washing machine, comprising: draining
water from a tub to outside the washing machine; driving a drum of
the washing machine at an accelerated speed; sensing an RPM of the
drum; judging whether or not the rotational speed of the drum
reaches a first reference speed, and stop driving the drum upon
judging that the rotational speed of the drum reaches the first
predetermined reference speed; during deceleration of the drum
after stopping the driving of the drum, begin injecting water into
the drum; re-driving the drum motor to a second reference speed;
judging whether or not the rotational acceleration of the drum is
greater than a predetermined reference acceleration; upon judging
that the rotational acceleration of the drum is greater than the
predetermined reference acceleration, stopping injection of water
into the drum; accelerating the drum to a maximum speed; and
stopping the driving of the drum.
19. the control method according to claim 18, wherein the first
predetermined reference speed is greater than a resonant speed of
the washing machine.
20. the control method according to claim 19, where the resonant
speed is a rotational speed of the drum at the moment when
vibration is rapidly generated due to properties of the washing
machine.
21. The control method according claim 20, wherein the second
reference speed is the resonant speed.
22. The control method according claim 18, wherein injecting water
into the drum comprises injecting water into the drum for a
designated time.
23. The control method according claim 22, wherein the designated
time is about 20 seconds.
24. The control method according claim 18, wherein injecting water
into the drum comprises injecting a designated amount of water into
the drum.
25. The control method according claim 18, wherein the
predetermined reference acceleration is 6 rpm/s.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Patent
Application No. 10-2012-0011215, filed on Feb. 3, 2012 in the
Korean Intellectual Property Office, the disclosure of which is
incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] Embodiments of the present disclosure relate to a washing
machine which executes a spin-drying cycle by rotating a drum
accommodating laundry and using centrifugal force applied to the
laundry, and a control method thereof.
[0004] 2. Description of the Related Art
[0005] In general, a washing machine includes a tub to contain
water (wash water or rinse water), a drum rotatably installed in
the tub and accommodating laundry, and a motor generating driving
force to rotate the drum, and achieves washing of the laundry
through an operation of raising and then dropping the laundry in
the drum when the cylindrical drum is rotated.
[0006] Such a washing machine executes washing of laundry through a
series of cycles, such as a washing cycle of separating
contaminants from the laundry using water containing detergent
(wash water), a rinsing cycle of removing foam or remaining
detergent from the laundry using water not containing detergent
(rinse water), and a spin-drying cycle of dehydrating the laundry.
Prior to execution of washing of the laundry through such a series
of cycles, a user places the laundry in the washing machine.
[0007] The conventional washing machine rinses the laundry and
separates contaminants from the laundry by repeating an operation
including water supply, rinse and drainage while executing the
rinsing cycle. Further, when the rinsing cycle has been completed,
the washing machine separates remaining contaminants from the
laundry by rotating the drum and using centrifugal force applied to
the laundry within the drum while executing the spin-drying cycle.
Therefore, the conventional washing machine requires a long time
and a large amount of water (wash water or rinse water) to execute
such an operation.
SUMMARY
[0008] Therefore, it is an aspect of the present disclosure to
provide a washing machine which injects water into a drum when the
rotational speed of the drum reaches a designated speed and then is
reduced while executing the spin-drying cycle of the washing
machine, and a control method thereof.
[0009] It is another aspect of the present disclosure to provide a
washing machine which stops injection of water into a drum when the
rotational acceleration of the drum is greater than a designated
acceleration, and a control method thereof.
[0010] Additional aspects of the disclosure will be set forth in
part in the description which follows and, in part, will be
apparent from the description, or may be learned by practice of the
disclosure.
[0011] In accordance with one aspect of the present disclosure, a
washing machine includes a drum accommodating laundry, a water
supply device supplying water to the inside of the drum, and a
controller controlling supply of water so that water is supplied
into the drum from when the rotational speed of the drum reaches a
first predetermined speed, to when the rotational speed of the drum
is decelerated, reaches a second predetermined speed and then
reaches a third speed more than the second speed and less than the
first speed, in a spin-drying cycle.
[0012] The water supply device may include an injection nozzle
injecting water into the drum and a water supply valve adjusting
supply of water from the outside of the washing machine to the
injection nozzle.
[0013] The first speed may be a rotational speed greater than the
second speed, and the second speed may be a resonant speed.
[0014] The controller may adjust at least one of an opening and
closing time and an opening and closing degree of the water supply
valve.
[0015] The controller may stop injection of water into the drum by
closing the water supply valve if the rotational acceleration of
the drum is greater than a predetermined acceleration while the
rotational speed of the drum reaches the second speed and then
reaches the third speed.
[0016] The controller may cause water to be supplied to the inside
of the drum until the rotational speed of the drum reaches the
second speed, maintains the second speed and then reaches the third
speed.
[0017] The first speed may be a rotational speed greater than the
second speed, and the second speed may be a rotational speed less
than a resonant speed.
[0018] The controller may adjust at least one of an opening and
closing time and an opening and closing degree of the water supply
valve.
[0019] The controller may stop injection of water into the drum by
closing the water supply valve if the rotational acceleration of
the drum is greater than a predetermined acceleration while the
rotational speed of the drum reaches the second speed and then
reaches the third speed.
[0020] In accordance with another aspect of the present disclosure,
a control method of a washing machine includes injecting water into
a drum accommodating laundry using an injection nozzle from when
the rotational speed of the drum reaches a first predetermined
speed in a spin-drying cycle, and stopping injection of water into
the drum when the rotational speed of the drum is decelerated and
reaches a second predetermined speed and then the rotational speed
of the drum reaches to a third speed more than the second speed and
less than the first speed.
[0021] The first speed may be a rotational speed greater than the
second speed, and the second speed may be a resonant speed.
[0022] The injection of water into the drum using the injection
nozzle may include injecting water into the drum by adjusting at
least one of an opening and closing time and an opening and closing
degree of a water supply valve adjusting supply of water to the
injection nozzle.
[0023] The stoppage of injection of water into the drum may include
stopping injection of water into the drum if the rotational
acceleration of the drum is greater than a predetermined
acceleration while the rotational speed of the drum reaches the
second speed and then reaches the third speed.
[0024] The stoppage of injection of water into the drum may include
stopping injection of water into the drum when the rotational speed
of the drum reaches the second speed, maintains the second speed
and then reaches the third speed.
[0025] The first speed may be a rotational speed greater than the
second speed, and the second speed may be a rotational speed
smaller than a resonant speed.
[0026] The injection of water into the drum using the injection
nozzle may include injecting water into the drum by adjusting at
least one of an opening and closing time and an opening and closing
degree of a water supply valve adjusting supply of water to the
injection nozzle.
[0027] The stoppage of injection of water into the drum may include
stopping injection of water into the drum if the rotational
acceleration of the drum is greater than a predetermined
acceleration while the rotational speed of the drum reaches the
second speed, maintains the second speed and then reaches the third
speed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] These and/or other aspects of the disclosure will become
apparent and more readily appreciated from the following
description of the embodiments, taken in conjunction with the
accompanying drawings of which:
[0029] FIG. 1 is a perspective view schematically illustrating the
external appearance of a washing machine in accordance with one
embodiment of the present disclosure;
[0030] FIG. 2 is a cross-sectional view schematically illustrating
the configuration of the washing machine in accordance with the
embodiment of the present disclosure;
[0031] FIG. 3 is a block diagram schematically illustrating a
control system of the washing machine in accordance with the
embodiment of the present disclosure;
[0032] FIG. 4 is a flowchart schematically illustrating a control
method of a washing machine in accordance with one embodiment of
the present disclosure;
[0033] FIG. 5 is a graph schematically illustrating the operating
state of a sub-water supply valve of the washing machine according
to time in the control method of FIG. 4;
[0034] FIG. 6 is a flowchart schematically illustrating a control
method of a washing machine in accordance with another embodiment
of the present disclosure;
[0035] FIG. 7 is a graph schematically illustrating the operating
state of a sub-water supply valve of the washing machine according
to time in the control method of FIG. 6;
[0036] FIG. 8 is a flowchart schematically illustrating a control
method of a washing machine in accordance with a further embodiment
of the present disclosure; and
[0037] FIG. 9 is a graph schematically illustrating the operating
state of a sub-water supply valve of the washing machine according
to time in the control method of FIG. 8.
DETAILED DESCRIPTION
[0038] Reference will now be made in detail to the embodiments of
the present disclosure, examples of which are illustrated in the
accompanying drawings, wherein like reference numerals refer to
like elements throughout.
[0039] FIG. 1 is a perspective view schematically illustrating the
external appearance of a washing machine in accordance with one
embodiment of the present disclosure, and FIG. 2 is a
cross-sectional view schematically illustrating the configuration
of the washing machine in accordance with the embodiment of the
present disclosure.
[0040] With reference to FIGS. 1 and 2, a washing machine 1
includes a main body 10 forming the external appearance of the
washing machine 1, a drum-type tub 11 installed in the main body 10
and storing water (wash water or rinse water), and a cylindrical
drum 20 rotatably installed in the tub 11 and provided with a
plurality of holes 24.
[0041] A motor 30 serving as a drive device to rotate a rotary
shaft 31 connected to the drum 20 so as to execute washing, rinsing
and spin-drying cycles is installed at the outside of the rear
surface of the tub 11.
[0042] The drum 20 includes a cylindrical part 21, a front panel 22
arranged at the front portion of the cylindrical part 21, and a
rear panel 23 arranged at the rear portion of the cylindrical part
21. An opening 26 through which laundry is put into and taken out
of the drum 20 is formed on the front panel 22, and the rotary
shaft 31 to transmit the driving force of the motor 30 is connected
to the rear panel 23.
[0043] The rotary shaft 31 is disposed between the drum 20 and the
motor 30. One end of the rotary shaft 31 is connected to the rear
panel 23 of the drum 20, and the other end of the rotary shaft 31
is extended to the outside of the rear wall of the tub 11. When the
motor 30 drives the rotary shaft 31, the drum 20 connected to the
rotary shaft 31 is rotated about the rotary shaft 31.
[0044] A bearing housing 33 rotatably supporting the rotary shaft
31 is installed on the rear wall of the tub 11. The bearing housing
33 may be formed of an aluminum alloy, and may be inserted into the
rear wall of the tub 11 when the tub 11 is formed through injection
molding. Bearings 32 are installed between the bearing housing 33
and the rotary shaft 31 so as to effectively rotate the rotary
shaft 31
[0045] During the washing cycle, the motor 30 rotates the drum 20
at a low speed in regular and reverse directions and thereby,
contaminants are removed from the laundry in the drum 20 through
repetition of raising and dropping of the laundry. During the
spin-drying cycle, when the motor rotates the drum 20 at a high
speed in one direction, water is separated from the laundry by
centrifugal force applied to the laundry.
[0046] A plurality of holes 24 for circulation of wash water is
formed through the circumferential surface of the drum 20, and a
plurality of lifters 25 is installed on the inner circumferential
surface of the drum 20 so as to raise and drop the laundry when the
drum 20 is rotated.
[0047] A balancer 15 formed in a disc shape and being concentric
with the center of rotation of the drum 20 is installed on each of
the front and rear surfaces of the drum 20. Such a balancer 15 may
reduce vibration generated due to the unbalanced eccentric
structure of the drum 20 and eccentricity of the laundry within the
drum 20 when the drum 20 is rotated.
[0048] The motor 30 may employ a universal motor including a field
coil and an armature or a brushless direct (BLDC) motor including
permanent magnets and electric magnets, or may employ any motor
which may be applied to small and medium-sized drums. Here, the RPM
and rotating direction of the motor 30 are controlled according to
the intensity and direction of current supplied to the motor
30.
[0049] A water level sensor 13 detecting a frequency varied
according to the water level so as to detect the amount (level) of
water within the tub 11 and a washing heater 12 heating water
within the tub 11 are installed in the lower portion of the tub
11.
[0050] Vibration sensors 14 are installed on the upper surface of
the tub 11. The vibration sensors 14 are installed at front and
rear ends of the tub 11 and detect vibration of the tub 11.
[0051] A door 17 opening and closing an inlet 27 through which
laundry is put into and taken out of the inside of the drum 20 is
installed on the front surface of the main body 10.
[0052] A detergent supply device 61 to supply detergents (for
example, a synthetic detergent or a natural soap detergent) and a
water supply device 40 to supply water (wash water or rinse water)
are installed above the tub 11.
[0053] The inside of the detergent supply device 61 is divided into
plural spaces, and the detergent supply device 61 is installed on
the front surface of the main body 10 so that a user easily puts
detergents and a fabric rinse into the respective spaces.
[0054] The water supply device 40 includes a main water supply pipe
43 connecting an external water supply pipe and the detergent
supply device 61 to supply water (wash water or rinse water) to the
inside of the tub 11, a main water supply valve 41 installed on the
main water supply pipe 43 and controlling supply of water, and a
connection pipe 46 connecting the detergent supply device 61 and
the tub 11. Such configuration allows water to be supplied to the
inside of the tub 11 via the detergent supply device 61, thereby
allowing the detergent within the detergent supply device 61
together with water to be supplied to the inside of the tub 11.
[0055] Further, the water supply device 40 includes a sub-water
supply pipe 44 provided with one end branching off from the main
water supply pipe 43 to supply water directly to the inside of the
drum 20, and an injection nozzle 45 installed at the other end of
the sub-water supply pipe 44 and injecting water of a high pressure
into the drum 20. A sub-water supply valve 42 is installed on the
sub-water supply pipe 44 and controls water supply through the
sub-water supply pipe 44. Such configuration allows water to be
supplied directly to the injection nozzle 45 not via the detergent
supply device 61. Thereby, water not mixed with detergent is
injected into the drum 20.
[0056] A control panel 70 on which various buttons to control the
washing machine 1 and a display unit are arranged is provided at
the upper portion of the front surface of the main body 10, and a
detergent feeding part 60 connected to the detergent supply device
61 so that detergent for washing machines is fed to the detergent
supply device 61 through the detergent feeding part 60 is provided
at one side of the control panel 70.
[0057] Various buttons to receive instructions from a user so as to
control the operation of the washing machine 1 and the display unit
to display the operating state of the washing machine 1 and the
manipulating state of the user are arranged on the control panel
70.
[0058] Further, the washing machine 1 in accordance with this
embodiment of the present disclosure includes a drain device 50 to
drain water from the inside of the tub 11, and the drain device 50
includes a first drain pipe 51 connected to the lower portion of
the tub 11 so as to drain water from the inside of the tub 11 to
the outside, a drain pump 52 installed on the first drain pipe 51,
and a second drain pipe 53 connected to the outlet of the drain
pimp 52.
[0059] Further, the washing machine 1 in accordance with this
embodiment of the present disclosure includes a damper 16 reducing
vibration under the tub 11 to damp vibration generated during the
operating process of the washing machine 1. The damper 16 is
provided under the tub 11 and movably supports the tub 11. That is,
the tub 11 is excited by vibration exciting force generated while
rotating the drum 20 and is thus vibrated in all directions,
namely, forward and backward, leftward and rightward, and upward
and backward directions. Such vibration of the tub 11 is reduced by
the damper 16.
[0060] FIG. 3 is a block diagram schematically illustrating a
control system of the washing machine in accordance with the
embodiment of the present disclosure.
[0061] With reference to FIG. 3, the washing machine includes an
input unit 111, a water level sensing unit 112, a vibration sensing
unit 113, an RPM sensing unit 114, a controller 120, and a driving
unit 130.
[0062] The input unit 111 serves to input driving information, such
as the washing cycle, the rinsing cycle and the spin-drying cycle
of the washing machine, by user manipulation, and may include keys,
buttons, switches, a touch pad, etc. The input unit 111 includes
any device which generates designated input data by manipulation,
such as push, contact, pressure, and rotation.
[0063] Further, the input unit 111 is provided on the control panel
70, and includes plural buttons to input driving information
regarding the operation of the washing machine (buttons to select
power, a reservation function, a wash water temperature, soaking,
washing, rinsing, spin-drying and a detergent kind, etc.)
[0064] The water level sensing unit 112 senses the level of water
supplied to the tub using water level sensor 13, the vibration
sensing unit 113 senses vibration of the tub using vibration
sensors 14, and the RPM sensing unit 114 senses the RPM of the
motor 30. Then, the water level sensing unit 112, the vibration
sensing unit 113 and the RPM sensing unit 114 input the sensed
water level, vibration and RPM to the controller 120.
[0065] The controller 120 is a microcomputer controlling the
overall operation of the washing machine, such as washing, rinsing
and spin-drying, according to input information, and sets amounts
of wash water and rinse water, a motor RPM and a motor operation
factor (motor on/off time), washing time and rinsing time according
to the weight of laundry (load) in a selected washing course.
[0066] The driving unit 130 drives the motor 30, the washing heater
12, water supply valves 140, and the drain pump 52, regarding the
operation of the washing machine according to a driving control
signal from the controller 120. Here, the water supply valves 140
include the main water supply valve 41 and the sub-water supply
valve 42.
[0067] Hereinafter, a control method of a washing machine and a
driving state of a sub-water supply valve in accordance with one
embodiment of the present disclosure will be described in
detail.
[0068] FIG. 4 is a flowchart schematically illustrating a control
method of a washing machine in accordance with one embodiment of
the present disclosure.
[0069] With reference to FIG. 4, the controller 120 drives the
drain pump 52 through the driving unit 130 to drain water from the
tub 11 to the outside (Operation S410). Thereby, water in the tub
11 is drained to the outside via the first drain pipe 51 and the
second drain pipe 53.
[0070] Further, the controller 120 drives the motor 30 through the
driving unit 130 to rotate the drum 20 at an accelerated speed
(Operation S411). Then, the RPM sensing unit 114 senses the RPM of
the motor 30. Here, since the RPM of the motor 30 corresponds to
the RPM of the drum 20, the controller 120 may calculate the
rotational speed and the rotational acceleration of the drum 20
through the RPM of the motor 30 sensed by the RPM sensing unit
114.
[0071] Thereafter, the controller 120 judges whether or not the
rotational speed of the drum 20 reaches a first predetermined
reference speed, and stops driving of the motor 30 through the
driving unit 130 upon judging that the rotational speed of the drum
20 reaches the first predetermined reference speed (Operation
S412).
[0072] The first predetermined reference speed may be greater than
the resonant speed of the washing machine 1. This is to resolve
eccentricity of laundry within the drum 20 while adjusting the
rotational speed of the drum 20, and to pass through the resonant
speed. Here, the resonant speed means the rotational speed of the
drum 20 at the moment when vibration is rapidly generated due to
properties of the washing machine 1.
[0073] Further, when the rotational speed of the drum 20 reaches
the first predetermined reference speed and then is decelerated,
the controller 120 causes water to be injected into the drum 20 by
opening the sub-water supply valve 42 through the driving unit 130
(Operation S413). Although driving of the motor 30 is stopped, the
rotational speed of the drum 20 is decelerated by frictional force
while maintaining rotation of the drum 20 due to rotational inertia
of the drum 20. Here, the controller 120 causes water to be
injected into the drum 20 by opening the sub-water supply valve 42
through the driving unit 130. Further, the controller 120 may cause
water to be injected into the drum 20 for a designated time by
adjusting the opening and closing time of the sub-water supply
valve 42, and cause a designated amount of water to be injected
into the drum 20 by adjusting the opening and closing degree of the
sub-water supply valve 4.
[0074] Thereby, since water of a high pressure injected into the
drum 20 passes through laundry and thus separates remaining
contaminants from the laundry, the laundry is cleanly rinsed in a
short time.
[0075] Thereafter, the controller 120 judges whether or not a
designated time after deceleration of the rotational speed of the
drum 20 has elapsed, and rotates the drum 20 at an accelerated
speed by re-driving the motor 30 through the driving unit 130 upon
judging that the designated time has elapsed (Operation S414). For
example, the designated time may be about 20 seconds.
[0076] As described above, although driving of the motor 30 is
stopped based on whether or not the rotational speed of the drum 20
reaches the first predetermined reference speed, driving of the
motor 30 may be stopped based on other criteria. For example, the
controller 120 may stop driving of the motor 30 through the driving
unit 130 by judging the degree of eccentricity of laundry. For this
purpose, the controller 120 may judge the degree of eccentricity of
laundry from the degree of vibration of the tub 11 sensed by the
vibration sensing unit 113, and stop driving of the motor 30
through the driving unit 130 when the degree of eccentricity of
laundry is greater than a predetermined reference degree of
eccentricity.
[0077] Further, when a designated time after stoppage of driving of
the motor 30 has elapsed, when the degree of eccentricity of
laundry is smaller than the reference degree of eccentricity, or
when the rotational speed of the drum 20 reaches a second reference
speed, the controller 120 causes the balancer to reach a position
reducing excessive vibration of the tub 11 while rotating the drum
20 at an accelerated speed by re-driving the motor 30 through the
driving unit 130. Here, the second reference speed may be the
resonant speed.
[0078] During such a process, the controller 120 may accelerate the
rotational speed of the drum 20 according to predetermined section
or predetermined time.
[0079] Further, the controller 120 judges whether or not the
rotational acceleration of the drum 20 is greater than a
predetermined reference acceleration (Operation S415). Upon judging
that the rotational acceleration of the drum 20 is greater than the
predetermined reference acceleration, the controller 120 stops
injection of water into the drum 20 by closing the sub-water supply
valve 42 through the driving unit 130 (Operation S416). On the
other hand, upon judging that the rotational acceleration of the
drum 20 is not greater than the predetermined reference
acceleration, the controller 120 maintains the open state of the
sub-water supply valve 42 through the driving unit 130 so as to
continuously inject water into the drum 20.
[0080] With reference to FIG. 5, when the rotational speed of the
drum 20 reaches the first predetermined reference speed, driving of
the motor 30 is stopped and thus the rotational speed of the drum
20 is decelerated, and the sub-water supply valve 42 is opened and
thus water is injected into the drum 20.
[0081] Further, when the designated time after deceleration of the
rotational speed of the drum 20 has elapsed or when the rotational
speed of the drum 20 reaches the second reference speed, the motor
30 is re-driven and thus the drum 20 is rotated at an accelerated
speed. Here, the rotational speed of the drum 20 is accelerated
according to predetermined section or predetermined time, as
described above. On the assumption that the predetermined reference
acceleration is 6 rpm/s, in a section where the rotational
acceleration of the drum 20 is 2 rpm/s, the rotational acceleration
of the drum 20 is not greater than the reference acceleration, and
thus the open state of the sub-water supply valve 42 is maintained
and water is continuously injected into the drum 20. However, in a
section where the rotational acceleration of the drum 20 is 8
rpm/s, the rotational acceleration of the drum is greater than the
reference acceleration, and thus the sub-water supply valve 42 is
closed and injection of water into the drum 20 is stopped.
[0082] On the other hand, when the rotational acceleration of the
drum 20 is not greater than the reference acceleration while the
drum 20 is rotated at an accelerated speed by re-driving the motor
30, in a section where the rotational speed of the drum 20 reaches
a third reference speed, the open state of the sub-water supply
valve 42 is maintained and water is continuously injected into the
drum 20. Here, the third reference speed may be more than the
second reference speed and be less than the first reference speed.
Hereinafter, for convenience of description, the third reference
speed will be described as being the first reference speed.
[0083] The reason for the above operation is that if the rotational
acceleration of the drum 20 is greater than the reference
acceleration, the amount of water discharged from laundry during
the spin-drying cycle is increased, and at this time, when water is
injected into the drum 20, the amount of water discharged from the
laundry is more increased, and as a result, water in the tub 11 is
not discharged to the outside by the drain pump and remains between
the tub 11 and the rotating drum 20. In order to prevent such a
drawback, in the control method of the washing machine in
accordance with this embodiment of the present disclosure,
injection of water into the drum 20 is stopped when the rotational
acceleration of the drum 20 is greater than the reference
acceleration.
[0084] When the rotational speed of the drum 20 is gradually
accelerated and reaches the third reference speed, the controller
120 maintains the rotational speed of the drum 20 by adjusting the
RPM of the motor 30 through the driving unit 130 (Operation S417).
While the rotational speed of the drum 20 maintains the third
reference speed, water in the tub 11 is continuously discharged to
the outside by the drain pump 52, and thus water discharged from
the laundry to the tub 11 does not remain between the tub 11 and
the drum 20 and is effectively drained.
[0085] Thereafter, the controller 120 judges whether or not a
designated time has elapsed, and rotates the drum 20 at an
accelerated speed by re-driving the motor 30 through the driving
unit 130 upon judging that the designated time has elapsed
(Operation S418).
[0086] Further, the controller 120 judges whether or not the
rotational speed of the drum 20 sensed by the RPM sensing unit 114
reaches the maximum speed, and stops driving of the motor 30
through the driving unit 130 upon judging that the rotational speed
of the drum 20 reaches the maximum speed (Operation S419). Although
driving of the motor 30 is stopped, the rotational speed of the
drum 20 is decelerated by frictional force while maintaining
rotation of the drum 20 due to rotational inertia of the drum
20.
[0087] Thereafter, the controller 120 judges whether or not the
drum 20 is stopped (Operation S420). Upon judging that the drum 20
is stopped, the controller 120 stops driving of the drain pump 52
through the driving unit 130 (Operation S421).
[0088] The spin-drying cycles of the washing machine may be divided
into an intermediate spin-drying cycle and a final spin-drying
cycle. Here, the intermediate spin-drying cycle means the
spin-drying cycle in which the drum 20 is rotated while draining
wash water from the tub 11 after the washing operation has been
completed, or means the spin-drying cycle in which, if plural
rinsing operations are executed, the drum 20 is rotated while
draining rinse water from the tub 11 between the respective rinsing
operations. Further, the final rinsing operation means the
spin-drying cycle in which the drum 20 is rotated to drain
remaining water from the tub 11 and to separate remaining water
from the laundry after the washing operation and the rinsing
operation have been completed.
[0089] The controller 120 may cause water to be injected into the
drum 20 by opening the sub-water supply valve 42 through the
driving unit 130, even while the rotational speed of the drum 20
reaches the maximum speed and is then decelerated, in case of the
intermediate spin-drying cycle. Thereby, the amount of water
consumed in the rinsing operation may be reduced while increasing
the rinsing effect of the laundry. Further, the controller 120
causes water not to be injected into the drum 20 while the
rotational speed of the drum 20 reaches the maximum speed and is
then decelerated, in order to minimize the amount of water
remaining in the laundry, in case of the final spin-drying
cycle.
[0090] FIG. 6 is a flowchart schematically illustrating a control
method of a washing machine in accordance with another embodiment
of the present disclosure. Hereinafter, a detailed description of a
process from Operation S610 to Operation S617 of FIG. 6 which is
the same as the process of FIG. 4 will be omitted.
[0091] With reference to FIG. 6, the controller 120 judges whether
or not a designated time has elapsed, and rotates the drum 20 at an
accelerated speed by re-driving the motor 30 through the driving
unit 130 upon that the designated time has elapsed (Operation
S618). Here, the controller 120 executes high-speed spin-drying of
laundry by driving the motor 30 to the maximum RPM.
[0092] During such a process, the controller 120 does not
continuously accelerate the motor 30 through the driving unit 130.
When the motor 30 is continuously accelerated, water between the
tub 11 and the drum 20 is not discharged by the drain pump 52 and
remains, and vibration and noise of the tub 11 is more increased
due to remaining water. Therefore, the controller 120 divides the
high-speed spin-drying process into plural sections, judges the
level of eccentricity of laundry from the level of vibration of the
tub 11 sensed by the vibration sensing unit 113 when the RPM of the
motor 30 reaches a predetermined RPM in each section, and drives
the motor 30 through the driving unit 130 according to the judged
level of eccentricity so as to gently increase the rotational speed
of the drum 20.
[0093] Thereafter, the controller 120 judges whether or not the
rotational speed of the drum 20 reaches the maximum speed, and
maintains the rotational speed of the drum 20 by adjusting the RPM
of the motor 30 through the driving unit 130 upon judging that the
rotational speed of the drum 20 reaches the maximum speed
(Operation S619). The controller 120 judges whether or not a
designated time has elapsed, and stops driving of the motor 30
through the driving unit 130 upon judging that the designated time
has elapsed (Operation S620). Although driving of the motor 30 is
stopped, the rotational speed of the drum 20 is decelerated by
frictional force while maintaining rotation of the drum 20 due to
rotational inertia of the drum 20. Thereafter, the controller 120
judges whether or not the drum 20 is stopped (Operation S621).
Then, upon judging that the drum 20 is stopped, the controller 120
stops driving of the drain pump 52 thorough the driving unit
130.
[0094] With reference to FIG. 7, when the rotational speed of the
drum 20 reaches the first predetermined reference speed, driving of
the motor 30 is stopped and thus the rotational speed of the drum
20 is decelerated, and the sub-water supply valve 42 is opened and
thus water is injected into the drum 20. Further, when the
designated time after deceleration of the rotational speed of the
drum 20 has elapsed or when the rotational speed of the drum 20
reaches the second reference speed, the motor 30 is re-driven and
thus the drum 20 is rotated at an accelerated speed. Here, the
rotational speed of the drum 20 is accelerated according to
predetermined section or predetermined time, as described above.
Here, maintaining of the open state of the sub-water supply valve
42 or closing of the sub-water supply valve 42 by comparing the
rotational acceleration of the drum 20 with the predetermined
reference acceleration is the same as that of FIG. 5.
[0095] FIG. 8 is a flowchart schematically illustrating a control
method of a washing machine in accordance with a further embodiment
of the present disclosure. Hereinafter, a detailed description of a
process of Operation S810 and Operation S811 of FIG. 8 which is the
same as the processes of FIG. 4 and FIG. 6 will be omitted.
[0096] With reference to FIG. 8, the controller 120 judges whether
or not the rotational speed of the drum 20 reaches a first
predetermined reference speed, and maintains the rotational speed
of the drum 20 by adjusting the RPM of the motor 30 through the
driving unit 130 upon judging that the rotational speed of the drum
20 reaches the first predetermined reference speed (Operation
S812).
[0097] The controller 120 judges whether or not a designated time
after maintenance of the rotational speed of the drum 20 has
elapsed, and stops driving of the motor 30 through the driving unit
130 upon judging that the designated time has elapsed (Operation
S813). Then, when the rotational speed of the drum 20 is
decelerated, the controller 120 causes water to be injected into
the drum 20 by opening the sub-water supply valve 42 through the
driving unit 130 (Operation S814).
[0098] Thereafter, the controller 120 judges whether or not a
designated time after deceleration of the rotational speed of the
drum 20 has elapsed, and maintains the rotational speed of the drum
20 by adjusting the RPM of the motor 30 while re-driving the motor
30 through the driving unit 130 when the designated time has
elapsed or when the rotational speed of the drum 20 reaches a
second reference speed (Operation S815).
[0099] The controller 120 judges whether or not a designated time
after maintenance of the rotational speed of the drum 20 has
elapsed, and rotates the drum 20 at an accelerated speed by
re-driving the motor 30 through the driving unit 130 upon judging
that the designated time has elapsed (Operation S816). Such control
of driving of the motor 30 may serve to cause the balancer to reach
a position reducing excessive vibration of the tub 11, in order to
resolve eccentricity of laundry in the same manner as in FIG.
4.
[0100] Thereafter, the controller 120 judges whether or not the
rotational acceleration of the drum 20 is greater than a
predetermined reference acceleration (Operation S817). Upon judging
that the rotational acceleration of the drum 20 is greater than the
predetermined reference acceleration, the controller 120 stops
injection of water into the drum 20 by closing the sub-water supply
valve 42 through the driving unit 130 (Operation S818). On the
other hand, upon judging that the rotational acceleration of the
drum 20 is not greater than the predetermined reference
acceleration, the controller 120 maintains the open state of the
sub-water supply valve 42 through the driving unit 130 so as to
continuously inject water into the drum 20.
[0101] With reference to FIG. 9, when the designated time from
maintenance of the first predetermined reference speed of the drum
20 has elapsed, driving of the motor 30 is stopped and thus the
rotational speed of the drum 20 is decelerated, and the sub-water
supply valve 42 is opened and thus water is injected into the drum
20. Further, when the designated time after deceleration of the
rotational speed of the drum 20 has elapsed or when the rotational
speed of the drum 20 reaches the second reference speed, the
rotational speed of the drum 20 is maintained by adjusting the RPM
of the motor 30.
[0102] The controller 120 judges the level of eccentricity of
laundry from the level of vibration of the tub 11 sensed by the
vibration sensing unit 113 while the rotational speed of the drum
is uniformly maintained. Further, the controller 120 judges the
position of the balancer based on the level of eccentricity of the
laundry, and rotates the drum 20 at an accelerated speed by
re-driving the motor 30 when the balancer is located at a position
reducing the excessive vibration of the tub 11.
[0103] On the assumption that the predetermined reference
acceleration is 6 rpm/s, in a section where the rotational
acceleration of the drum 20 is 0 rpm/s, the rotational acceleration
of the drum 20 is not greater than the reference acceleration, and
thus the open state of the sub-water supply valve 42 is maintained
and water is continuously injected into the drum 20. However, in a
section where the drum 20 is rotated at an accelerated speed, i.e.,
where the rotational acceleration of the drum 20 is 8 rpm/s, the
rotational acceleration of the drum is greater than the reference
acceleration, and thus the sub-water supply valve 42 is closed and
injection of water into the drum 20 is stopped.
[0104] When the rotational speed of the drum 20 is gradually
accelerated and reaches a third reference speed, the controller 120
maintains the rotational speed of the drum 20 by adjusting the RPM
of the motor 30 through the driving unit 130 (Operation S819).
Thereafter, the controller 120 judges whether or not a designated
time has elapsed, and rotates the drum 20 at an accelerated speed
by re-driving the motor 30 through the driving unit 130 upon
judging that the designated time has elapsed (Operation S820).
[0105] Further, the controller 120 judges whether or not the
rotational speed of the drum 20 sensed by the RPM sensing unit 114
reaches the maximum speed, and maintains the rotational speed of
the drum 20 by adjusting the RPM of the motor 30 through the
driving unit 130 upon judging that the rotational speed of the drum
20 reaches the maximum speed (Operation S821). Thereafter, the
controller 120 judges whether or not a designated time has elapsed,
and stops driving of the motor 30 through the driving unit 130 upon
judging that the designated time has elapsed (Operation S822).
Although driving of the motor 30 is stopped, the rotational speed
of the drum 20 is decelerated by frictional force while maintaining
rotation of the drum 20 due to rotational inertia of the drum 20.
Thereafter, the controller 120 judges whether or not the drum 20 is
stopped (Operation S823). Upon judging that the drum 20 is stopped,
the controller 120 stops driving of the drain pump 52 through the
driving unit 130 (Operation S824).
[0106] Although one embodiment of the present disclosure sets the
maximum speed of the drum 20 at about 1,000 rpm, the rotational
speed of the drum 20 may be changed according to the capacity or
structure of the washing machine.
[0107] As is apparent from the above description, in a washing
machine and a control method thereof in accordance with one
embodiment of the present disclosure, when the rotational speed of
a drum reaches a designated speed and is then decelerated while
executing the spin-drying cycle of the washing machine, water is
injected into a drum. Therefore, a contact time of water with
laundry is secured, the injected water separates remaining
contaminants from the laundry while passing through the laundry,
and thus the laundry may be rinsed in a short time. Further, since
injection of water into the drum is stopped when the rotational
acceleration of the drum is greater than a designated acceleration,
thus a phenomenon in which the amount of water discharged to a tub
is increased and water in the tub is not discharged to the outside
and remains between the tub and the rotating drum may be
prevented.
[0108] Although a few embodiments of the present disclosure have
been shown and described, it would be appreciated by those skilled
in the art that changes may be made in these embodiments without
departing from the principles and spirit of the disclosure, the
scope of which is defined in the claims and their equivalents.
* * * * *