CROSS-REFERENCE TO RELATED APPLICATION
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The present invention relates to a washing machine and a rinsing control method thereof,
and, more particularly, to a washing machine that performs a rinsing operation while
rotating a drum at a predetermined RPM and a rinsing control method thereof.
2. Description of the Related Art
[0003] Generally, a washing machine (normally, a drum type washing machine) is a machine,
including a water tub to receive water (wash water or rinse water), a cylindrical
drum rotatably mounted in the water tub to receive laundry, and a motor to generate
a drive force necessary to rotate the drum, which lifts the laundry along the inner
wall of the drum and drops the laundry, during the rotation of the drum, to wash the
laundry.
[0004] The washing machine performs washing through a series of operations, e.g., a washing
operation to separate contaminants from the laundry with water containing detergent
(specifically, wash water), a rinsing operation to rinse out bubbles or residual detergent
from the laundry with water containing no detergent (specifically, rinse water), and
a spin-drying operation to spin-dry the laundry. In the rinsing operation, the drum
is stopped, and water draining and intermediate spin-drying processes are performed,
after the completion of the washing operation, and then the laundry is brought into
contact with water and, at the same time, is lifted and dropped, while alternatively
rotating the drum at a velocity (approximately 30 to 50 RPM) to rinse the laundry
using a fall of water during the supply of water, thereby rinsing the laundry. In
other words, the rinsing operation is performed through a series of processes, e.g.,
the stoppage of the drum, the drainage, the spin drying, and the rinsing (the alternating
rotation of the drum at a velocity of 30 to 50 RPM).
[0005] The rinsing operation is achieved by repeating the above-mentioned series of processes
several times. To spin-dry the laundry after the drainage, a process to uniformly
distribute the laundry W in the drum 12 as shown in FIG. 1 is needed. This is because
the drum 12 is rotated at a predetermined RPM (approximately 1000 RPM or more) to
spin-dry the laundry at high velocity such that the spin-drying process, performed
during the rinsing operation, drains water contained in the laundry W outside by a
centrifugal force. If the drum 12 is rotated at the predetermined RPM (approximately
1000 RPM or more) in an unbalanced state in which the laundry W is nonuniformly distributed
along the inner wall of the drum 12 as shown in FIG. 2, an eccentric force is applied
to a rotary shaft of the drum 12 with the result that great vibration is generated.
Also, when the spin-drying process is performed in the unbalanced state, spin-drying
time may increase and spin-drying errors may occur due to the unbalance. Furthermore,
when the laundry W is picked out after the completion of washing, a large amount of
force is necessary to untangle the tangled laundry, which causes dissatisfaction of
housewives, main users of the washing machine.
[0006] In order to solve the problem, according to the related art, a laundry untangling
process is performed to untangle the tangled laundry W through the alternating rotation
of the drum 12 before the drum 12 is rotated at the predetermined RPM (approximately
1000 RPM or more) at the time of every spin-drying process in the rinsing operation,
which is repeated several times, and the unbalance value is measured. When the measured
unbalance value is within an allowable value, the drum 12 is rotated at the predetermined
RPM (approximately 1000 RPM or more) to perform the spin-drying process to drain water
contained in the laundry W outside by a centrifugal force. On the other hand, when
the measured unbalance value exceeds the allowable value, the laundry untangling process
is reperformed to untangle the tangled laundry W through the alternating rotation
of the drum 12.
[0007] In the washing machine above, however, the laundry untangling process is performed
before the drum 12 is rotated at the predetermined RPM (approximately 1000 RPM or
more) at the time of every spin-drying process in the rinsing operation, which is
repeated several times, and the unbalance value is measured. As a result, the total
rinsing time increases. Also, a velocity (alternating rotation of 30 to 50 RPM) of
water passing through the laundry W is low in the rinsing process using the fall of
water, with the result that the detergent contained in the laundry W does not well
dissolve, or the dissolved detergent does not flow out of the laundry W. Consequently,
the residual detergent is left in the laundry, whereby the rinsing efficiency is lowered.
To raise the rinsing efficiency, it is required to supply a large amount of water
sufficient to fully wet the laundry, which increases the water consumption.
SUMMARY OF THE INVENTION
[0008] Therefore, it is an aspect of the invention to provide a washing machine and a rinsing
control method thereof that are capable of performing a rinsing operation, while rotating
a drum in a predetermined RPM, thereby improving rinsing efficiency.
[0009] It is another aspect of the invention to provide a washing machine and a rinsing
control method thereof that are capable of performing a rinsing operation at a predetermined
RPM to maintain a balanced state without stopping a drum after spin-drying, thereby
omitting a laundry untangling process performed at the time of every spin-drying,
and therefore, reducing the total rinsing time.
[0010] It is a further aspect of the invention to provide a washing machine and a rinsing
control method thereof that are capable of performing further rinsing within reduced
rinsing time, thereby achieving much more rinsing within the total rinsing time, and
therefore, improving rinsing efficiency.
[0011] In accordance with one aspect, the present invention provides a rinsing control method
of a washing machine including a drum to receive laundry and a motor to rotate the
drum, the rinsing control method including rotating the drum to perform spin-drying
and decelerating the drum to a predetermined velocity to perform rinsing.
[0012] Preferably, the rinsing control method further includes performing a laundry untangling
process to uniformly distribute the laundry in the drum to perform the spin-drying,
and the laundry untangling process is performed only once during the rinsing, which
is performed several times.
[0013] Preferably, the predetermined velocity is a balance maintenance velocity to uniformly
distribute the laundry in the drum though the deceleration of the drum after the spin-drying.
[0014] Preferably, the balance maintenance velocity is a velocity to cling the laundry to
the inner wall of the drum while maintaining balance without eccentricity.
[0015] Preferably, the balance maintenance velocity is approximately 100 RPM or more.
[0016] Preferably, the performing rinsing includes performing the supply of water, rinsing,
and drainage of water for rinsing while rotating the drum at the balance maintenance
velocity.
[0017] Preferably, the performing rinsing includes rotating the drum to perform spin-drying
after the drainage and continuously performing the supply of water, rinsing, and drainage
of water for the next rinsing while rotating the drum at the balance maintenance velocity.
[0018] Preferably, the balance maintenance velocity is a velocity in which the water passes
through the laundry by a centrifugal force to dissolve detergent contained in the
laundry.
[0019] Preferably, the balance maintenance velocity is a velocity in which the water passes
through the laundry by a centrifugal force to immediately discharge detergent remaining
in the laundry.
[0020] In accordance with another aspect, the present invention provides a rinsing control
method of a washing machine including a drum to receive laundry and a motor to rotate
the drum, the rinsing control method including rotating the drum to perform spin-drying
and decelerating the drum to a predetermined velocity to supply water.
[0021] In accordance with a further aspect, the present invention provides a washing machine
including a drum to receive laundry, a motor to rotate the drum, and a control unit
to control the velocity of the drum such that the drum is rotated to perform spin-drying
and is decelerated to a predetermined velocity to perform rinsing.
[0022] Preferably, the control unit controls a laundry untangling process to be performed
to uniformly distribute the laundry in the drum to perform the spin-drying, the laundry
untangling process being performed only once during the rinsing, which is performed
several times.
[0023] Preferably, the washing machine further includes a water supply unit, and the control
unit controls the motor to rotate the drum at the balance maintenance velocity and
the water supply unit to supply water, during the rotation of the drum, to perform
the rinsing.
[0024] Preferably, the washing machine further includes a drainage unit, and the control
unit controls the drainage unit to drain the water during the rotation of the drum.
[0025] Additional aspects and/or advantages of the invention will be set forth in part in
the description which follows and, in part, will be obvious from the description,
or may be learned by practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] These and/or other aspects and advantages of the invention will become apparent and
more readily appreciated from the following description of the embodiments, taken
in conjunction with the accompanying drawings, of which:
FIG. 1 is a view illustrating the balanced state of laundry in a drum of a washing
machine;
FIG. 2 is a view illustrating the unbalanced state of laundry in a drum of a washing
machine;
FIG. 3 is a sectional view illustrating the structure of a washing machine according
to an embodiment of the present invention;
FIG. 4 is a rinsing control block diagram of the washing machine according to the
embodiment of the present invention;
FIGS. 5A and 5B are flow charts illustrating a rinsing control method of the washing
machine according to the embodiment of the present invention; and
FIG. 6 is a graph illustrating a rinsing operation of the washing machine according
to the embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] Reference will now be made in detail to the embodiment of the present invention,
examples of which are illustrated in the accompanying drawings, wherein like reference
numerals refer to like elements throughout. The embodiment is described below to explain
the present invention by referring to the figures.
[0028] FIG. 3 is a sectional view illustrating the structure of a washing machine according
to an embodiment of the present invention.
[0029] Referring to FIG. 3, the washing machine includes a water tub 11 mounted in a machine
body 10 to receive water (wash water or rinse water) and a cylindrical drum 12 rotatably
mounted in the water tub 11. The drum 12 has a plurality of spin-drying holes.
[0030] Outside a rear 11 c of the water tub 11 is mounted a motor 15 to rotate a rotary
shaft 13 connected to the drum 12 to perform washing, rinsing, and spin-drying operations.
The motor 15 includes a stator 15a fixed to the rear 11 c of the water tub 11, a rotor
15b rotatably mounted around the stator 15a, and a rotary plate 15c connected between
the rotor 15b and the rotary shaft 13.
[0031] At the inside bottom of the water tub 11 is mounted a wash heater 16 to heat water
(specifically, wash water) supplied into the water tub 11. To this end, a heater receiving
part 17 is formed at the bottom of the water tub 11 such that the heater receiving
part 17 protrudes downward to receive the wash heater 16 and, at the same time, collect
a predetermined amount of water. This is because the wash heater 16 can be immersed
in the water collected in the heater receiving part 17, and the drum can be rotated
without the interference with the wash heater 16 since the wash heater 16 is received
in the heater receiving part 17.
[0032] Also, the machine body 10 is provided at the front thereof with an inlet 10b which
corresponds to an inlet 12b of the drum 12 and an inlet 11b of the water tub 11 such
that laundry W is put in or taken out from the drum 12 through the inlet 10b. At the
machine body 10 is also mounted a door 18 to open and close the inlet 10b. Between
the inlet 10b of the machine body 10 and the inlet 11 b of the water tub 11 is mounted
a cylindrical diaphragm 11 d to prevent the leakage of wash water.
[0033] Above the water tub 11 are mounted a detergent supply unit 19 to supply detergent
and a water supply unit 20 to supply water (wash water or rinse water).
[0034] The detergent supply unit 19 has several partitioned spaces. The detergent supply
unit 19 is mounted at the front side of the machine body 10 such that a user easily
puts detergent and rinse in the respective partitioned spaces.
[0035] The water supply unit 20 includes a first water supply pipe 22 connected between
an external water supply pipe 21, through which water (wash water or rinse water)
is supplied into the water tub 11, and the detergent supply unit 19, a second water
supply pipe 23 connected between the detergent supply unit 19 and the water tub 11,
and a water supply valve 24 mounted on the first water supply pipe 22 to control the
supply of water. Consequently, water is supplied into the water tub 11 via the detergent
supply unit 19 such that detergent is supplied into the water tub 11 together with
the water.
[0036] The washing machine further includes a drainage unit 30 to drain the water in the
water tub 11 and a circulation unit 40 to supply the water in the water tub 11 into
the drum 12. The drainage unit 30 includes a first drainage pipe 31 connected to a
drainage port 17a formed at the heater receiving part 17 in the bottom of the water
tub 11 to guide the water in the water tub 11 outside, a drainage pump 32 mounted
on the first drainage pipe 31, and a second drainage pipe 33 connected to the outlet
of the drainage pump 32. The circulation unit 40 includes a flow channel switching
valve 41 mounted on the second drainage pipe 33, a circulation pipe 42 extending from
the flow channel switching valve 41 to the inlet 12b of the drum 12, and a spray nozzle
43 mounted at the outlet of the circulation pipe 42. The flow channel switching valve
41 serves to switch flow channels such that the water from the outlet of the drainage
pump 32 is drained outside or flows to the circulation pipe 42. The flow channel switching
valve 41 may be an electric three-way valve. The spray nozzle 43 is mounted adjacent
to the inlet 12b of the drum 12 such that the spray nozzle 43 sprays water into the
drum 12 through the inlet 12b of the drum 12.
[0037] Consequently, when the drainage pump 32 is operated while the flow channel switching
valve 41 is operated such that water flows to the circulation pipe 42, water in the
bottom of the water tub 11 is supplied into the rotary drum 12 through the first drainage
pipe 31 and the circulation pipe 42. Also, when the drainage pump 32 is operated while
the flow channel switching valve 41 is operated such that water flows to the second
drainage pipe 33, the water in the water tub 11 is drained outside.
[0038] FIG. 4 is a rinsing control block diagram of the washing machine according to the
embodiment of the present invention. The washing machine further includes an input
unit 50, a water level detection unit 52, a temperature detection unit 54, a control
unit 56, a drive unit 58, a velocity detection unit 60, and a current detection unit
62.
[0039] The input unit 50 inputs operation information, such as a washing course, a washing
temperature, spin-drying RPM, and the addition of rinsing, which are selected by a
user, to the control unit 56. The water level detection unit 52 detects the water
level of water supplied into the water tub 11, and the temperature detection unit
54 detects the temperature of water supplied into the water tub 11.
[0040] The control unit 56 is a microprocessor to control the overall operation of the washing
machine, such as washing, rinsing, and spin-drying, based on the operation information
inputted from the input unit 50. The control unit 56 stores the amount of rinse water,
motor RPM and operation rate (motor on-off time), and rinsing time set according to
the amount of load (the weight of laundry) in the selected washing course. The control
unit 56 controls the rinsing operation, including the supply of water, rinsing, and
drainage of water, to be performed, while continuously rotating the drum 12 at a velocity
(100 to 150 RPM) to maintain a balanced state without stopping the motor 12 after
spin-drying, such that the water passes through the laundry W at high velocity and
is drained.
[0041] Also, the control unit 56 controls intermediate spin-drying (initial spin-drying)
to be performed after the drainage of wash water (detergent and water) to perform
rinsing after the washing. At this time, as shown in FIG. 1, a laundry untangling
process is performed to uniformly distribute the laundry W in the drum 12 such that
the laundry W is maintained in a balanced state, and then the unbalance value is measured,
which is necessary to smoothly spin-dry the laundry W. When the measured unbalance
value is within an allowable value, the control unit 45 controls the drum 12 to be
rotated at a predetermined RPM (approximately 800 to 1000 RPM) such that spin-drying
is performed. After the completion of the spin-drying, the control unit 56 lowers
the velocity of the drum 12 to a velocity to maintain the balanced state, e.g., approximately
100 to 150 RPM, without stopping the drum 12, and control the rinsing operation, including
the supply of water, rinsing, and drainage of water, to be performed while continuously
rotating the drum 12. At this time, the balanced state is continuously maintained,
and therefore, the control unit 56 controls spin-drying to be immediately performed
without the execution of a laundry untangling process.
[0042] In the rinsing operation, which is repeatedly performed, the laundry W is maintained
in the balanced state in which the laundry W is uniformly distributed along the inner
wall of the drum 12. Consequently, control unit 56 omits a laundry untangling process
and an unbalanced state measuring process at the time of every spin-drying. As a result,
the total rinsing time is reduced. Also, when the control unit 56 controls further
rinsing to be performed within the reduced rinsing time, it is possible to perform
much more rinsing within rinsing time necessary for the related art washing machine,
thereby improving rinsing efficiency.
[0043] Also, the control unit 56 controls the operations of the motor 15, the water supply
unit 20 and the drainage unit 30 such that a rinsing operation, including the supply
of water, rinsing, and drainage of water, is performed, while the drum 12 is rotated
at a velocity (approximately 100 to 150 RPM) to maintain the balanced state in one
direction, with the result that water (specifically, rinse water) passes through the
laundry W at high velocity by a centrifugal force to dissolve the detergent contained
in the laundry W, and the water having passed through the laundry W is immediately
drained to fully remove the residual detergent from the laundry W.
[0044] The drive unit 58 drives the motor 15, the wash heater 16, the water supply valve
24, the drainage pump 32, and the flow channel switching valve 41 according to a drive
control signal of the control unit 56. The velocity detection unit 60 inputs a motor
velocity signal corresponding to the rotation velocity of the drum 12 to the control
unit 56 to detect whether the velocity of the drum 12 has lowered due to the velocity
reduction of the motor 15. The current detection unit 62 inputs a motor current signal
corresponding to the rotation velocity of the drum 12 to the control unit 56 to measure
an unbalanced state.
[0045] Hereinafter, the operation of the washing machine with the above-stated construction
and a rinsing control method thereof will be described.
[0046] FIGS. 5A and 5B are flow charts illustrating a rinsing control method of the washing
machine according to the embodiment of the present invention.
[0047] A washing operation to perform washing with water and detergent is identical to the
operation of a general washing machine, and therefore, a detailed description thereof
will not be given.
[0048] When a user puts laundry W in the drum 12 and selects operation information, such
as a washing course, spin-drying RPM, and the addition of rinsing, based on the kinds
of the laundry W, the operation information selected by the user is inputted to the
control unit 56 through the input unit 54.
[0049] Subsequently, the control unit 56 determines whether the power is on so as to perform
a rinsing operation based on the operation information inputted from the input unit
54 (100).
[0050] When the power is on, the control unit 56 detects the amount of load (the weight
of laundry) put in the drum 12, and sets the minimum amount of water, motor operation
rate (motor on-off time), and washing and rinsing time for washing and rinsing based
on the detected amount of load.
[0051] Subsequently, the control unit 56 controls a washing operation to be performed such
that water (specifically, wash water) necessary to wash the laundry W is supplied
into the water tub 11 together with detergent to supply water having an amount set
based on the amount of load, the washing is performed by a frictional force with the
drum 12 and a falling force of the laundry W while the wash water (water and detergent)
is well absorbed into the laundry, by the rotation of the drum 12 and the operation
of the circulation unit 40 (102).
[0052] During the washing process, the control unit 56 determines whether washing time set
based on the amount of load has elapsed (104). When the washing time has not elapsed,
the procedure returns to Operation 102 to continue the washing operation to perform
washing with wash water.
[0053] When it is determined at Operation 104 that the washing time has elapsed, the control
unit 56 drains the wash water through the drainage unit 30 (106), and controls a laundry
untangling process to be performed in which the motor 15 is controlled through the
drive unit 58 to smoothly perform spin-drying, such that the drum 15 is alternately
rotated, thereby untangling the tangled laundry W (108).
[0054] The laundry untangling process is a process in which an operation to stop the drum
for a predetermined time (approximately 5 seconds) after the motor 26 is rotated in
the forward direction at a predetermined RPM (e.g. approximately 40 to 45 RPM) for
a predetermined time (e.g. approximately 5 seconds) and an operation to stop the drum
for a predetermined time (e.g. approximately 5 seconds) after the motor 26 is rotated
in the reverse direction at a predetermined RPM (e.g. approximately 40 to 45 RPM)
for a predetermined time (e.g. approximately 5 seconds) are repeatedly performed in
an alternating fashion. In the laundry untangling process, therefore, the drum 12
is alternately rotated to untangle the laundry W, with the result that the laundry
W is uniformly distributed in the drum 12 to maintain the balance state, as shown
in FIG. 1.
[0055] After the completion of the laundry untangling process, the control unit 56 measures
an unbalance value through the current detection unit 62 from a predetermined unbalance
measurement velocity before the rotation of the drum 12 at a predetermined RPM (e.g.
approximately 800 to 1000 RPM) (110), and determines whether the measured unbalance
value is equal to or less than a predetermined allowable value (112).
[0056] A method of measuring the unbalance value by the control unit 56 is to estimate the
size of unbalance in the drum 12 utilizing weight information of the laundry W and
a control variable, such as a velocity ripple or a current ripple. This method is
disclosed in Korean Patent Application No.
2005-105681, which has been filed in the name of the applicant of the present application. Also,
a generally known technology may be applied, and therefore, a detailed description
thereof will not be given.
[0057] When it is determined at Operation 112 that the unbalance value exceeds the allowable
value, the control unit 56 determines that the state of the laundry is the unbalanced
state and controls the operation of the motor 15 through the drive unit 58 such that
the drum 12 is stopped (113). After that, the procedure returns to Operation 108 to
reperform the laundry untangling process to maintain the balanced state.
[0058] When it is determined at Operation 112 that the unbalance value is equal to or less
than the allowable value, the control unit 56 determines that the state of the laundry
is the balanced state and performs a spin-drying process in which the operation of
the motor 15 is controlled through the drive unit 58, such that the drum 12 is rotated
at the predetermined RPM (approximately 800 to 1000 RPM), to drain the water contained
in the laundry W outside by a centrifugal force (114).
[0059] Subsequently, the control unit 56 determines whether the spin-drying has been completed
(116). When the spin-drying has not been completed, the procedure returns to Operation
114 to continue the spin-drying. On the other hand, when the spin-drying has been
completed, the control unit 56 reduces the velocity of the motor 15 through the drive
unit 58 to reduce the rotation velocity of the drum 12 to a velocity (approximately
100 to 150 RPM) to maintain the balanced state without stopping the drum 12 (118).
[0060] At this time, the velocity detection unit 60 detects a motor velocity signal corresponding
to the rotation velocity of the drum 12 and inputs the detected motor velocity signal
to the control unit 56.
[0061] Subsequently, the control unit 56 determines whether the rotation velocity of the
drum 12, detected by the velocity detection unit 60, is a predetermined balance maintenance
velocity (a velocity in which the laundry is maintained in the balanced state while
remains clung to the inner wall of the drum; approximately 100 to 150 RPM) (120).
When the rotation velocity of the drum 12 is not the balance maintenance velocity,
the control unit reduces the velocity of the motor 15 and thus the rotation velocity
of the drum 12.
[0062] When it is determined at Operation 120 that the rotation velocity of the drum 12
is the balance maintenance velocity, the control unit 56 performs rinsing operation,.
[0063] At this time, the control unit 56 controls the drum 12 to be rotated in one direction
while maintaining the rotation velocity of the drum 12 at the balance maintenance
velocity (approximately 100 to 150 RPM), such that the laundry W remains clung to
the inner wall of the drum 12, to reduce rinsing time and improve rinsing efficiency.
During the rotation of the drum 12, the control unit 56 controls the water supply
unit 20 to supply rinse water. As a result, the water supply valve 24 is opened, and
therefore, water (rinse water) is supplied into the water tub 11 through the supply
water pipes 21, 22, and 23 (122).
[0064] During the supply of rinse water for rinsing, the water level detection unit 52 detects
the water level of the rinse water supplied into the water tub 11, and the control
unit 56 determines whether the detected water level is a predetermined water level
(124). The predetermined water level may be set at various different levels.
[0065] When the water level of the rinse water is not the predetermined water level, the
control unit 56 controls water to be continuously supplied into the water tub 11 until
the water level of the rinse water reaches the predetermined water level. When the
water level of the rinse water is the predetermined water level, the control unit
56 controls the control valve 24 to be closed such that the supply of water is interrupted
(126).
[0066] After the supply of water is interrupted, the control unit 56 controls the rinsing
operation to be performed in which the drum is rotated in one direction while the
rotation velocity of the drum 12 is continuously maintained at the balance maintenance
velocity (e.g. approximately 100 to 150 RPM) such that the laundry W remains clung
to the inner wall of the drum 12, and the rinse water is supplied into the drum 12
through the circulation unit 40, to rinse the laundry W with the rinse water supplied
into the water tub 11.
[0067] Water is supplied during the rotation of the drum in one direction at the velocity
(approximately 100 to 150 RPM) at which the balanced state is maintained while the
laundry W remains clung to the inner wall of the drum 12. After the supply of water
is completed, the drum 12 is continuously rotated in one direction to continue the
rinsing, with the result that the rinse water passes through the laundry at high velocity.
[0068] The passage of the rinse water through the laundry will be described in more detail.
[0069] When laundry having mass m performs a circular movement along the circumference of
the drum 12 having a radius r at uniform velocity, a centrifugal force F is represented
by the following equation:
Where, w is angular velocity and v is circular movement velocity of the drum 12 (v=
rw).
[0070] Consequently, when the drum 12 is rotated in one direction at a velocity (e.g. approximately
100 to 150 RPM) higher than the rotation velocity (approximately 30 to 50 RPM) of
the drum 12 of the related art washing machine, rinse water passes through the laundry
at high velocity by a centrifugal force, with the result that detergent contained
in the laundry is rapidly dissolved, and therefore, rinsing efficiency is improved.
[0071] During the rinsing operation, the control unit 56 determines whether predetermined
rinsing time has elapsed (130). When the rinsing time has not lapsed, the procedure
returns to Operation 128 to continue the rinsing operation while maintaining the rotation
velocity of the drum 12.
[0072] When it is determined at Operation 130 that the rinsing time has lapsed, the control
unit 56 controls the drainage pump 32 and the flow channel switching valve 41 to drain
the rinse water.
[0073] Even during the drainage of the rinse water, to improve rinsing efficiency, the control
unit 56 controls the drum 12 to be rotated in one direction while the rotation velocity
of the drum 12 is maintained at the balance maintenance velocity (e.g. approximately
100 to 150 RPM) such that the laundry W remains clung to the inner wall of the drum
12 (132).
[0074] When the drum 12 is rotated in one direction at the velocity (approximately 100 to
150 RPM) to maintain the balanced state while the laundry W remains clung to the inner
wall of the drum 12 to drain the rinse water, the water having passed through the
laundry W is immediately drained. Consequently, the amount of detergent left in the
laundry W is reduced to further improve rinsing efficiency, as compared to the related
art in which water is drained while the drum is stopped.
[0075] After the drainage of the rinse water, the control unit 56 raises the rotation velocity
of the drum 12 according to the operation of the motor 15 such that the drum is rotated
at a predetermined number of rotations (approximately 1000 RPM) to perform intermediate
spin-drying (134).
[0076] That is, the present invention omits a laundry untangling process, which was performed
at the time of every spin-drying to smoothly perform spin-drying after the drainage
of the rinse water, and accelerates the rotation velocity of the drum 12 to the predetermined
number of rotations (approximately 1000 RPM) such that the spin-drying is immediately
performed.
[0077] More specifically, the laundry untangling process is performed at the time of every
spin-drying to smoothly achieve spin-drying after the drainage in the related art.
According to the present embodiment, however, the rinsing operation, including the
supply of water, rinsing, and drainage of water, is performed while the drum is continuously
rotated at a velocity (100 to 150 RPM) to maintain the balanced state without stopping
the drum 12, as shown in FIG. 6, after the initial spin-drying (intermediate spin-drying
after washing). Consequently, the laundry untangling process to smoothly achieve spin-drying
may only be performed once (even though the present invention does not limit the laundry
untangling process to be performed only once) after the initial spin-drying (intermediate
spin-drying after washing). Although the laundry untangling process may be omitted
at subsequent spin-drying processes, the laundry W is continuously maintained in the
balanced state in which the laundry W is uniformly distributed along the inner wall
of the drum 12. Consequently, the laundry untangling process and the process to measure
the unbalanced state after the laundry untangling process may be omitted, and therefore,
the total rinsing time is reduced.
[0078] Subsequently, the control unit 56 determines whether the rinsing operation is the
final rinsing (136). When the rinsing operation is not the final rinsing, the procedure
returns to Operation 114 to continuously perform the supply of water, rinsing, and
drainage of water for the next rinsing while rotating the drum 12 at a velocity (100
to 150 RPM) to maintain the balanced state without stopping the drum 12. When the
rinsing operation is the final rinsing, the spin-drying is performed at a predetermined
final spin-drying RPM (approximately 1100 RPM or more) (138), and then the drum 12
is stopped to end the operation.
[0079] As apparent from the above description, the washing machine and the rinsing control
method thereof according to the present invention have the effect of performing a
rinsing operation, including the supply of water, rinsing, and drainage of water,
while rotating the drum at a predetermined RPM, such that water can pass through laundry
at high velocity and be drained by a centrifugal force, thereby improving rinsing
efficiency.
[0080] Also, the washing machine and the rinsing control method thereof according to the
present invention have the effect of performing a rinsing operation at a predetermined
RPM to maintain a balanced state without stopping the drum after spin-drying, thereby
omitting a laundry untangling process performed at the time of every spin-drying,
and therefore, reducing the total rinsing time. Furthermore, the washing machine and
the rinsing control method thereof according to the present invention have the effect
of performing further rinsing within reduced rinsing time, thereby improving rinsing
efficiency.
[0081] Although a few embodiments of the present invention have been shown and described,
it would be appreciated by those skilled in the art that changes may be made in this
embodiment without departing from the principles and spirit of the invention, the
scope of which is defined in the claims and their equivalents.
1. A rinsing control method of a washing machine including a drum to receive laundry
and a motor to rotate the drum, the rinsing control method comprising:
rotating the drum to perform spin-drying; and
decelerating the drum to a predetermined velocity to perform rinsing operation.
2. The rinsing control method according to claim 1, further comprising:
performing a laundry untangling process to uniformly distribute the laundry in the
drum to perform the spin-drying, wherein
the laundry untangling process is performed only once during the rinsing operation,
which is performed several times.
3. The rinsing control method according to claim 1, wherein the predetermined velocity
is a balance maintenance velocity to uniformly distribute the laundry in the drum
though the deceleration of the drum after the spin-drying.
4. The rinsing control method according to claim 3, wherein the balance maintenance velocity
is a velocity to cling the laundry to the inner wall of the drum while maintaining
balance without eccentricity.
5. The rinsing control method according to claim 3, wherein the balance maintenance velocity
is approximately 100 RPM or more.
6. The rinsing control method according to claim 3, wherein the performing rinsing operation
includes performing the supply of water, rinsing, and drainage of water for rinsing
operation while rotating the drum at the balance maintenance velocity.
7. The rinsing control method according to claim 6, wherein the performing rinsing operation
includes
rotating the drum to perform spin-drying after the drainage, and
continuously performing the supply of water, rinsing, and drainage of water for the
next rinsing operation while rotating the drum at the balance maintenance velocity.
8. The rinsing control method according to claim 6, wherein the balance maintenance velocity
is a velocity in which the water passes through the laundry by a centrifugal force
to dissolve detergent contained in the laundry.
9. The rinsing control method according to claim 6, wherein the balance maintenance velocity
is a velocity in which the water passes through the laundry by a centrifugal force
to immediately discharge detergent remaining in the laundry.
10. A rinsing control method of a washing machine including a drum to receive laundry
and a motor to rotate the drum, the rinsing control method comprising:
rotating the drum to perform spin-drying; and
decelerating the drum to a predetermined velocity to supply water.
11. A washing machine comprising:
a drum to receive laundry;
a motor to rotate the drum; and
a control unit to control the velocity of the drum such that the drum is rotated to
perform spin-drying and is decelerated to a predetermined velocity to perform rinsing
operation.
12. The washing machine according to claim 11, wherein the control unit controls a laundry
untangling process to be performed to uniformly distribute the laundry in the drum
to perform the spin-drying, the laundry untangling process being performed only once
during the rinsing operation, which is performed several times.
13. The washing machine according to claim 11, wherein the predetermined velocity is a
balance maintenance velocity to uniformly distribute the laundry in the drum though
the deceleration of the drum after the spin-drying.
14. The washing machine according to claim 13, further comprising:
a water supply unit, wherein
the control unit controls the motor to rotate the drum at the balance maintenance
velocity and the water supply unit to supply water, during the rotation of the drum,
to perform the rinsing.
15. The washing machine according to claim 14, further comprising:
a drainage unit, wherein
the control unit controls the drainage unit to drain the water during the rotation
of the drum.