U.S. patent application number 11/984812 was filed with the patent office on 2008-08-28 for washing machine and washing control method of the same.
This patent application is currently assigned to SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to Eun Suk Bang, Hyun Sook Kim, Sung Hoon Kim, Jae Ryong Park, Jee Hun Park, Sang Yeon Pyo.
Application Number | 20080201867 11/984812 |
Document ID | / |
Family ID | 39493595 |
Filed Date | 2008-08-28 |
United States Patent
Application |
20080201867 |
Kind Code |
A1 |
Bang; Eun Suk ; et
al. |
August 28, 2008 |
Washing machine and washing control method of the same
Abstract
A washing machine and a washing control method of the same that
squeeze detergent water from the laundry, heat the squeezed
detergent water, and resupply the heated detergent water, thereby
performing heated washing using a minimized amount of water. The
washing machine includes a water tub, a rotary drum mounted in the
water tub to receive laundry, and a circulation unit to supply
water from the water tub into the rotary drum. The washing control
method includes detecting an amount of a load according to a weight
of the laundry, supplying an amount of water set according to the
detected amount of load, supplying the water in the water tub into
the rotary drum through the circulation unit to wet the laundry,
separating the water from the laundry by rotating the rotary drum,
and heating the separated water and resupplying the heated water
into the rotary drum through the circulation unit.
Inventors: |
Bang; Eun Suk; (Seoul,
KR) ; Pyo; Sang Yeon; (Suwon-si, KR) ; Kim;
Hyun Sook; (Suwon-si, KR) ; Park; Jae Ryong;
(Hweseong-si, KR) ; Kim; Sung Hoon; (Suwon-si,
KR) ; Park; Jee Hun; (Suwon-si, KR) |
Correspondence
Address: |
STAAS & HALSEY LLP
SUITE 700, 1201 NEW YORK AVENUE, N.W.
WASHINGTON
DC
20005
US
|
Assignee: |
SAMSUNG ELECTRONICS CO.,
LTD.
Suwon-si
KR
|
Family ID: |
39493595 |
Appl. No.: |
11/984812 |
Filed: |
November 21, 2007 |
Current U.S.
Class: |
8/158 ; 68/12.03;
68/12.04; 68/12.05; 68/12.15; 68/212 |
Current CPC
Class: |
D06F 2202/10 20130101;
D06F 2204/086 20130101; Y02B 40/56 20130101; D06F 35/006 20130101;
Y02B 40/00 20130101; D06F 33/00 20130101 |
Class at
Publication: |
8/158 ; 68/12.03;
68/12.04; 68/12.05; 68/12.15; 68/212 |
International
Class: |
D06F 33/02 20060101
D06F033/02; D06F 23/00 20060101 D06F023/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 26, 2007 |
KR |
2007-19123 |
Claims
1. A washing control method of a washing machine including a water
tub, a rotary drum mounted in the water tub to receive laundry, and
a circulation unit to supply water from the water tub into the
rotary drum, the washing control method comprising: detecting an
amount of a load according to a weight of the laundry; supplying an
amount of water set according to the detected amount of the load
into the water tub; supplying the water in the water tub into the
rotary drum through the circulation unit to wet the laundry;
separating the water, absorbed in the laundry, from the laundry by
rotating the rotary drum; and heating the separated water and
resupplying the heated water into the rotary drum through the
circulation unit.
2. The washing control method according to claim 1, wherein the set
amount of water is a minimum water supply amount set based on the
detected amount of the load.
3. The washing control method according to claim 1, wherein the
water supplied into the water tub is detergent water including
detergent and wash water mixed with each other.
4. The washing control method according to claim 3, wherein the
separating the water, absorbed in the laundry, from the laundry
includes squeezing out the detergent water absorbed in the laundry
from the laundry by rotating the rotary drum at a minimum RPM at
which the laundry is spin-dried.
5. The washing control method according to claim 4, wherein the
minimum RPM is approximately 50 to 300 RPM.
6. The washing control method according to claim 1, further
comprising: detecting a water level of the water before heating the
water, wherein the detected water level is compared with a
predetermined water level, and, when the detected water level is
below the predetermined water level, water is supplied into the
water tub.
7. The washing control method according to claim 6, wherein the
predetermined water level is a heater safety water level at which
the water is heated.
8. The washing control method according to claim 1, further
comprising: detecting a temperature of the water, wherein the
detected temperature is compared with a predetermined target
temperature, and, when the detected temperature is below the target
temperature, the water is heated until the temperature of the water
reaches the target temperature.
9. The washing control method according to claim 8, wherein the
heating the separated water includes activating a washing heater
until the temperature of the water reaches the target temperature,
and, when the detected temperature has reached the target
temperature, deactivating the washing heater to maintain the water
resupplied into the rotary drum at an optimum temperature.
10. A washing machine comprising: a water tub to receive water; a
rotary drum mounted in the water tub to receive laundry; a
circulation unit to supply the water in the water tub into the
rotary drum; a water supply unit to control the supply of water; a
washing heater to heat water; and a control unit to control the
water supply unit to supply water into the water tub, control the
circulation unit to supply the water in the water tub into the
rotary drum such that the laundry is wetted by the water, control
the washing heater to heat the water in the water tub after the
water, absorbed in the laundry, is separated from the laundry by
the rotation of the rotary drum, and control the heated water to be
resupplied into the rotary drum such that washing is performed
using the heated water.
11. The washing machine according to claim 10, wherein the control
unit detects an amount of a load according to a weight of the
laundry and controls the water supply unit to supply an amount of
water set according to the detected amount of the load into the
water tub.
12. The washing machine according to claim 11, wherein the set
amount of water is a minimum water supply amount set based on the
detected amount of the load.
13. The washing machine according to claim 10, wherein the water
supplied into the water tub is detergent water including detergent
and wash water mixed with each other.
14. The washing machine according to claim 13, wherein the control
unit rotates the rotary drum, at a minimum RPM at which the laundry
is spin-dried to squeeze out the detergent water absorbed in the
laundry from the laundry.
15. The washing machine according to claim 14, wherein the minimum
RPM is approximately 50 to 300 RPM.
16. The washing machine according to claim 10, further comprising:
a water level detection unit to detect a water level of the water,
wherein the control unit compares the water level detected by the
water level detection unit with a predetermined water level before
heating the water, and, when the detected water level is below the
predetermined water level, controls the water supply unit to supply
water into the water tub.
17. The washing machine according to claim 16, wherein the
predetermined water level is a heater safety water level at which
the water is heated.
18. The washing machine according to claim 10, further comprising:
a temperature detection unit to detect a temperature of the water,
wherein the control unit compares the temperature detected by the
temperature detection unit with a predetermined target temperature,
and activates the washing heater until the temperature of the water
reaches the target temperature when the detected temperature is
below the target temperature.
19. The washing machine according to claim 18, wherein the heating
the separated water includes when the detected temperature has
reached the target temperature, deactivating the washing heater to
maintain the water resupplied into the rotary drum at an optimum
temperature.
20. A controller for a washing machine, comprising: means for
detecting an amount of a load according to a weight of laundry;
means for causing an amount of water set according to the detected
amount of the load to be supplied into the water tub; means for
causing the water in the water tub to be supplied into the rotary
drum through the circulation unit to wet the laundry; means for
causing the rotary drum to rotate and separate the water absorbed
in the laundry from the laundry; and means for causing the
separated water to be heated and, after heating to a predetermined
temperature, to be resupplied into the rotary drum through the
circulation unit.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Patent
Application No. 2007-19123, filed on Feb. 26, 2007 in the Korean
Intellectual Property Office, the disclosure of which is
incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] The present invention relates to a washing machine and a
washing control method of the same to perform heated washing using
a small amount of water.
[0004] 2. Description of the Related Art
[0005] 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) and a cylindrical rotary drum rotatably
mounted in the water tub to receive laundry, that washes the
laundry by lifting and dropping the laundry in the rotary drum
along the inner surface of the rotary drum during the rotation of
the rotary drum.
[0006] This washing machine detects the weight of laundry (the
amount of a load) to decide the amount of wash water according to a
user's selection of a washing course, supplies water having an
amount sufficient to wet the laundry and detergent into the water
tub according to the decided amount of wash water, heats the water
and the detergent supplied into the water tub using a heater
disposed between the water tub and the rotary drum, when heated
washing is to be performed, and performs a washing operation while
detergent water (water+detergent), the temperature of which is
increased by the heater, is forwarded to the laundry, and the
laundry is dropped by the rotation of the rotary drum.
[0007] However, it is necessary to fill a space defined between the
water tub and the rotary drum with water to perform the washing. As
a result, a large amount of water is used, and therefore, a large
amount of energy is required to increase the temperature of the
water. Also, as water consumption increases, a large amount of
detergent is used to perform high-concentration washing.
[0008] Furthermore, when the amount of water supplied is small, the
amount of water gathered in the water tub is also small, because
the water is absorbed in the laundry during the wetting of the
laundry. As a result, the heater is exposed, and therefore, it is
not possible to perform heated washing. Although the water is
gathered in the water tub, only the gathered water is heated, and
therefore, the heated water does not reach the center of the
laundry. Consequently, the temperature of the laundry is not
uniformly distributed, whereby the washing efficiency is
variable.
SUMMARY
[0009] Therefore, it is an aspect of the invention to provide a
washing machine and a washing control method of the same to rotate
a rotary drum, at the minimum RPM at which laundry is spin-dried,
to squeeze out water from the laundry, heating the squeezed water,
and resupplying the heated water to the laundry, thereby performing
heated washing using a minimized amount of water.
[0010] In another aspect of the invention, a washing machine and a
washing control method of the same supply water during the
squeezing out of water from laundry by the rotation of a rotary
drum at the minimum RPM at which the laundry is spin-dried, and
heat the squeezed water when the squeezed water is below a heater
safety water level, thereby securing the safety of heated
washing.
[0011] In a further aspect of the invention, a washing machine and
a washing control method of the same increase the temperature of
water to a target temperature during the squeezing out of water
from laundry, by the rotation of a rotary drum at the minimum RPM
at which the laundry is spin-dried, and heat the squeezed water,
and uniformly distribute the heated water throughout the laundry,
thereby accomplishing uniform washing efficiency.
[0012] In accordance with one aspect of the present invention, a
washing control method of a washing machine that includes a water
tub, a rotary drum mounted in the water tub to receive laundry, and
a circulation unit to supply water from the water tub into the
rotary drum, the washing control method includes detecting the
amount of the load according to the weight of the laundry,
supplying an amount of water set according to the detected amount
of the load into the water tub, supplying the water in the water
tub into the rotary drum through the circulation unit to wet the
laundry, separating the water absorbed in the laundry from the
laundry by rotating the rotary drum, and heating the separated
water and resupplying the heated water into the rotary drum through
the circulation unit.
[0013] Generally, the set amount of water is the minimum water
supply amount set based on the detected amount of the load.
[0014] Typically, the water supplied into the water tub is
detergent water including detergent and wash water mixed with each
other.
[0015] Generally, the operation of separating the water absorbed in
the laundry from the laundry includes squeezing out the detergent
water absorbed in the laundry from the laundry by rotating the
rotary drum at the minimum RPM at which the laundry may be
spin-dried.
[0016] Typically, the minimum RPM is approximately 50 to 300
RPM.
[0017] Generally, the washing control method further includes
detecting the water level of the water before heating the water.
The detected water level is compared with a predetermined water
level, and, when the detected water level is below the
predetermined water level, water is supplied into the water
tub.
[0018] Typically, the predetermined water level is a heater safety
water level at which the water may be heated.
[0019] Generally, the washing control method further includes
detecting the temperature of the water. The detected temperature is
compared with a predetermined target temperature, and, when the
detected temperature is below the target temperature, the water is
heated until the temperature of the water reaches the target
temperature.
[0020] Typically, the operation of heating the separated water
includes activating a washing heater to heat the water until the
temperature of the water reaches the target temperature, and, when
the detected temperature has reached the target temperature,
deactivating the washing heater to maintain the water resupplied
into the rotary drum at the optimum temperature.
[0021] In another aspect, a washing machine includes a water tub to
receive water, a rotary drum mounted in the water tub to receive
laundry, a circulation unit to supply the water in the water tub
into the rotary drum, a water supply unit to control the supply of
water, a washing heater to heat water, and a control unit to
control the water supply unit to supply water into the water tub,
control the circulation unit to supply the water in the water tub
into the rotary drum such that the laundry is wetted by the water,
control the washing heater to heat the water in the water tub after
the water absorbed in the laundry is separated from the laundry by
the rotation of the rotary drum, and control the heated water to be
resupplied into the rotary drum such that washing is performed
using the heated water.
[0022] Generally, the control unit detects the amount of the load
according to the weight of the laundry and controls the water
supply unit to supply an amount of water set according to the
detected amount of the load into the water tub.
[0023] Typically, the control unit rotates the rotary drum at the
minimum RPM at which the laundry may be spin-dried to squeeze out
the detergent water absorbed in the laundry from the laundry.
[0024] Generally, the washing machine further includes a water
level detection unit to detect the water level of the water. The
control unit compares the water level detected by the water level
detection unit with a predetermined water level before heating the
water, and, when the detected water level is below the
predetermined water level, controls the water supply unit to supply
water into the water tub.
[0025] Typically, the washing machine further includes a
temperature detection unit to detect the temperature of the water.
The control unit compares the temperature detected by the
temperature detection unit with a predetermined target temperature,
activating the washing heater until the temperature of the water
reaches the target temperature when the detected temperature is
below the target temperature, and deactivating the washing heater
to maintain the water resupplied into the rotary drum at the
optimum temperature when the detected temperature has reached the
target temperature.
[0026] 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
[0027] 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:
[0028] FIG. 1 is a sectional view illustrating the supply of water
to laundry in a washing machine according to an embodiment of the
present invention;
[0029] FIG. 2 is a sectional view illustrating the squeezing out of
water from the laundry supply of water to laundry in the washing
machine according to an embodiment of the present invention;
[0030] FIG. 3 is a perspective view of a rotary drum applied to an
embodiment of the present invention;
[0031] FIG. 4 is a sectional view of the rotary drum;
[0032] FIG. 5 is a control block diagram of the washing machine
according to an embodiment of the present invention; and
[0033] FIGS. 6A and 6B are flow charts illustrating a washing
control method of the washing machine according to an embodiment of
the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0034] 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.
[0035] FIG. 1 is a sectional view illustrating the supply of water
to laundry in a washing machine according to an embodiment of the
present invention, and FIG. 2 is a sectional view illustrating the
squeezing out of water from the laundry in accordance with an
embodiment of the present invention.
[0036] Referring to FIGS. 1 and 2, the washing machine includes a
drum-type water tub 11 mounted in a machine body 10 to receive
water (wash water or rinse water) and a cylindrical rotary drum 12
rotatably mounted in the water tub 11.
[0037] The water tub 11 is mounted at a predetermined angle .alpha.
to the installation surface of the washing machine such that a
front part 11a, having an inlet 11b formed therein, is located at a
higher position than a rear part 11c. The rotary drum 12 is mounted
in the water tub 11 in the same inclination angle as the water tub
11 such that a front part 12a, having an inlet 12b formed therein,
is located at a higher position than a rear part 12c.
[0038] Outside the rear part 11c of the water tub 11 is mounted a
drive unit, such as a motor 15, to rotate a rotary shaft 13
connected to the rotary drum 12 such that washing, rinsing, and
spin-drying operations are performed. The motor 15 includes a
stator 15a fixed to the rear part 11c of the water tub 11, a rotor
15b rotatably disposed around the stator 15a, and a rotary plate
15c connected between the rotor 15b and the rotary shaft 13.
[0039] At the inside bottom of the water tub 11 is mounted a
washing heater 16 to heat water (specifically, detergent water)
supplied into the water tub 11. For the installation of the washing
heater 16, a heater receiving part 17 is formed in the bottom of
the water tub 11. The heater receiving part 17 protrudes downward
such that a predetermined amount of water is gathered in the heater
receiving part 17 while the washing heater 16 is received in the
heater receiving part 17. Consequently, the washing heater 16 is
immersed in the water gathered in the heater receiving part 17.
Since the washing heater 16 is received in the heater receiving
part 17, the rotary drum 12 may be rotated without interference
between the rotary drum 12 and the washing heater 16.
[0040] In the front of the machine body 10 is formed an inlet 18b
corresponding to the inlet 12b of the rotary drum 12 and the inlet
11b of the water tub 11 such that laundry may be put into or taken
out from the rotary drum 12. At the machine body 10, adjacent to
the inlet 18b, is mounted a door 18 to open and close the inlet
18b. Between the inlet 10b of the machine body 10 and the inlet 11b
of the water tub 11 is mounted a cylindrical diaphragm 11d to
prevent the leakage of wash water.
[0041] 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).
[0042] 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. The detergent supply unit 19
includes a preliminary washing detergent box to store detergent
used for preliminary washing, a main washing detergent box to store
detergent used for main washing, and a rinse box to store rinse
used for rinsing. The details of the detergent supply unit 19 are
disclosed in Korean Patent Application No. 2003-0011317, which has
been filed in the name of the applicant of the present application.
Of course, other well-known technologies may be applied to the
detergent supply unit 19.
[0043] 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.
[0044] 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, heated by the washing heater 16, in the water tub
11 into the rotary 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 to the 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 rotary drum
12, and an injection nozzle 43 mounted at the outlet of the
circulation pipe 42. The flow channel switching valve 41 serves to
switch flow channels such that water from the outlet of the
drainage pump 32 is drained to the outside or flows to the
circulation pipe 42. The flow channel switching valve 41 may be an
electric three-way valve. The injection nozzle 43 is mounted
adjacent to the inlet 12b of the rotary drum 12 such that the
injection nozzle 43 injects water into the rotary drum 12 through
the inlet 12b of the rotary drum 12.
[0045] 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 injected 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 to the outside.
[0046] FIG. 3 is a perspective view of a rotary drum applied to an
embodiment of the present invention, and FIG. 4 is a sectional view
of the rotary drum.
[0047] Referring to FIGS. 3 and 4, the rotary drum 12 is mounted
such that a rotation axis A of the rotary drum 12 is at a
predetermined angle .alpha. to the installation surface of the
washing machine while the front part 12a, having the inlet 12b
formed therein, is directed forward. In this case, the rotary shaft
13, coupled to the center of the rear part 12c of the rotary drum
12, is rotatably supported at the rear central part of the water
tub 11 such that the rotary drum 12 may be rotated in the water tub
11.
[0048] The reason why the rotation axis A of the rotary drum 12 is
at the predetermined angle .alpha. to the installation surface of
the washing machine is that, when water is supplied into the rotary
drum 12, a predetermined amount of water necessary for washing and
rinsing is gathered in the rotary drum 12 such that laundry is
wetted by the water.
[0049] In the front part 12a of the rotary drum 12 are formed a
plurality of spin-drying holes 12d. Inside the rotary drum 12 are
mounted a plurality of lifters 14 to raise and drop laundry in the
rotary drum 12 during the rotation of the rotary drum 12. The
reason why the circumference of the rotary drum 12 is at a
predetermined angle .beta. to the rotation axis A of the rotary
drum 12 and the holes 12d are formed along the edge of the front
part 12a is to guide water, moving in the radial direction of the
rotary drum 12 due to a centrifugal force caused when the rotary
drum 12 is rotated at the minimum RPM at which laundry may be
spin-dried, to the holes 12d of the front part 12a along the
incline such that the water is drained out of the rotary drum 12.
For effective drainage, the tilt angle .beta. at the circumference
of the rotary drum 12 is generally 0.5 degrees or more.
[0050] FIG. 5 is a control block diagram of the washing machine
according to an embodiment of the present invention. In addition to
the components shown in FIGS. 1 and 2, the washing machine further
includes a signal input unit 50, a water level detection unit 52, a
temperature detection unit 54, a control unit 56, and a drive unit
58.
[0051] The signal 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.
[0052] The control unit 56 is a microcomputer to control the
washing machine based on the operation information inputted from
the signal input unit 50. The control unit 56 stores the amount of
wash water, motor RPM and operation rate (motor on-off time), and
washing time set according to the amount of the load (the weight of
laundry) in the selected washing course.
[0053] For heated washing, therefore, the control unit 56 supplies
the water (specifically, detergent water) in the water tub 11 into
the rotary drum 12 through the circulation unit 40 to wet laundry
after the supply of a predetermined amount of wash water, rotates
the rotary drum 12, at the minimum RPM at which the laundry may be
spin-dried, to squeeze out water from the laundry, and detects the
water level of the squeezed water. The control unit 56 controls the
driving of the motor 15, the washing heater 16, the water supply
unit 20, and the circulation unit 40 such that, when the detected
water level is below a predetermined heater safety water level,
water is supplied through the water supply unit 20 until the water
level reaches the heater safety water level, and, when the detected
water level reaches the predetermined heater safety water level,
water is heated by activating the washing heater 16 until the
temperature of the water reaches a target temperature, and the
heated water is resupplied into the rotary drum 12.
[0054] The drive unit 58 drives the motor 15, the washing 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.
[0055] Hereinafter, the operation of the washing machine with the
above-stated construction and a washing control method of the
washing machine will be described.
[0056] FIGS. 6A and 6B are flow charts illustrating a washing
control method of the washing machine according to an embodiment of
the present invention.
[0057] First, when a user puts laundry in the rotary drum 12 and
selects operation information, such as a washing course, washing
temperature, spin-drying RPM, and the addition of rinsing, based on
the kinds of the laundry, the operation information selected by the
user is inputted to the control unit 56 through the signal input
unit 54.
[0058] Subsequently, the control unit 56 determines whether the
power is on so that a washing operation is performed based on the
operation information inputted from the signal input unit 54
(S100).
[0059] When the power is on, the control unit 56 detects the amount
of the load (the weight of laundry) put in the rotary drum 12
(S102), and sets the minimum amount of wash water, motor operation
rate (motor on-off time), and washing time for each washing course
based on the detected amount of the load (S104).
[0060] Subsequently, the control unit 56 controls the water supply
unit 20 to supply the minimum amount of wash water set for each
washing course based on the amount of the load. As a result, the
water supply valve 24 is opened, and water (wash water) flows
through the water supply pipes 21 and 22, the detergent supply unit
19, and the second water supply pipe 23, whereby detergent water,
(water+detergent) is supplied into the water tub 11 (S106).
[0061] During the supply of detergent water for washing, the water
level detection unit 52 detects the water level of the detergent
water supplied into the water tub 11 to determine whether the
detected water level is at a predetermined first water level (a
water level decided according to the set amount of wash water)
(S108).
[0062] When the detected water level has not reached the
predetermined first water level, the control unit 56 controls water
to be continuously supplied into the water tub 11 until the water
level reaches the first water level. When the detected water level
reaches the predetermined first water level, the control unit 56
closes the water supply valve 24 such that the water supply is
interrupted (S110).
[0063] After the interruption of the water supply, the control unit
56 controls the circulation unit 40 such that laundry is wetted by
the detergent water supplied into the water tub 11. As a result,
the flow channel switching valve 41 of the circulation unit 50 is
operated such that the outlet of the drainage pump 32 communicates
with the circulation pipe 42. As the drainage pump 32 is operated,
the detergent water in the bottom of the water tub 11 is supplied
into the rotary drum 12 through the drainage pipe 31 and the
circulation pipe 42 (S112). At this time, the detergent water,
supplied into the rotary drum 12, is injected to the laundry
through the injection nozzle 43 such that the laundry is uniformly
wetted by the detergent water.
[0064] After a wetting operation to supply the detergent water in
the water tub 11 into the rotary drum 12 through the circulation
unit 40 is performed for a predetermined period of time (time
decided according to the amount of the load; approximately 4
minutes), the control unit 56 rotates the rotary drum 12 at a
predetermined first RPM (the minimum RPM at which laundry may be
spin-dried; approximately 50 to 300 RPM) for a predetermined period
of time (approximately 1 minute) to secure a heater safety water
level at which the detergent water may be heated.
[0065] As the rotary drum 12 is rotated at the first RPM, detergent
water absorbed in the laundry is separated from the laundry and is
introduced into the water tub 11 through the holes 12d formed in
the front part 12a of the rotary drum 12. The water level of the
detergent water gathered in the water tub 11 is detected
(S114).
[0066] The control unit 56 determines whether the water level of
the detergent water gathered in the water tub 11 has reached a
predetermined second water level (a heater safety water level
necessary for heated washing; a water level at which the washing
heater is immersed in the detergent water) (S116). When the water
level of the detergent water does not reach a level of the second
water level, the control unit 56 controls the water supply unit 20
to resupply water into the water tub 11 until the water level of
the detergent water reaches the second water level (S118).
[0067] When it is determined at S116 that the water level of the
detergent water gathered in the water tub 11 has reached the second
water level, which means that the heater safety water level for
heating is secured, the control unit 56 controls the washing heater
to heat the detergent water gathered in the water tub 11
(S120).
[0068] At this time, the control unit 56 controls the circulation
unit 40 to be operated such that the laundry is heated by the
heated detergent water. As a result, the heated detergent water in
the water tub 11 is supplied into the rotary drum 12 through the
drainage pipe 31 and the circulation pipe 42 (S122). The detergent
water, supplied into the rotary drum 12, is injected to the laundry
through the injection nozzle 43 with the result that the laundry is
uniformly heated.
[0069] Also, the control unit 56 detects the temperature of the
heated detergent water by utilizing the temperature detection unit
54 (S124), and determines whether the temperature of the detergent
water has reached a predetermined target temperature (a default
value based on washing temperature set by a user or a basic default
value) (S126).
[0070] When it is determined at S126 that the temperature of the
detergent water has not yet reached the target temperature, the
procedure returns to S120 to activate the washing heater 16 until
the temperature of the detergent water has reached the target
temperature.
[0071] When it is determined at S126, on the other hand, that the
temperature of the detergent water has reached the target
temperature, the control unit 56 turns the washing heater 16 off
(i.e., deactivates the washing heater) (S128), and continuously
supplies the detergent water, heated to the target temperature,
into the rotary drum 12 through the circulation unit 40 to
uniformly heat the entire laundry (S130).
[0072] At this time, the control unit 56 controls the motor 15 to
be driven, such that the rotary drum 12 is operated at a
predetermined second RPM (washing RPM) and operation rate, to
perform heated washing that accomplishes uniform washing efficiency
using the minimum amount of water (S132).
[0073] As the heated washing is performed, the temperature of the
detergent water gradually decreases. At this time, the temperature
detection unit 54 detects the temperature of the detergent water
and inputs the detected temperature of the detergent water to the
control unit 56.
[0074] The control unit 56 determines whether the detected
temperature of the detergent water is below a predetermined first
temperature (a temperature of the detergent water at which the
washing heater is redriven) (S136). When the detected temperature
of the detergent water is below the first temperature, the control
unit 56 controls the rotary drum 12 to be rotated at a
predetermined third RPM (approximately 150 RPM) for a predetermined
period of time (approximately 1 minute) such that the detergent
water is separated from the laundry (S138), and the procedure
returns to S120 to heat the detergent water to the target
temperature.
[0075] When it is determined at S136 that the detected temperature
of the detergent water is not below the first temperature, which
means that the temperature of the detergent water is suitable for
heated washing, the control unit 56 determines whether a washing
time set according to the amount of the load has elapsed (S140).
When the washing time has not elapsed, the procedure returns to
S130 to perform a washing operation that washes the laundry using
the heated detergent water.
[0076] When it is determined at S140 that the washing time has
elapsed, the control unit 56 performs a subsequent rinsing and
spin-drying operation set according to the amount of the load
(S142).
[0077] As is apparent from the above description, the washing
machine according to embodiments of the present invention and the
washing control method of the same have the effect of rotating the
rotary drum at the minimum RPM at which laundry may be spin-dried,
after the supply of water, to squeeze out water from the laundry,
heating the squeezed water, and resupplying the heated water to the
laundry, thereby performing heated washing using a minimized amount
of water, and therefore, accomplishing water and power saving.
[0078] Furthermore, the washing machine according to embodiments of
the present invention and the washing control method of the same
have the effect of supplying water, during the squeezing out of
water from laundry, by the rotation of the rotary drum at the
minimum RPM at which the laundry may be spin-dried, and heating the
squeezed water, when the squeezed water is below the heater safety
water level, thereby securing the safety of heated washing. Also,
the washing machine according to embodiments of the present
invention and the washing control method of the same have the
effect of increasing the temperature of water to the target
temperature during the squeezing out of water from laundry by the
rotation of the rotary drum at the minimum RPM at which the laundry
may be spin-dried, and heating the squeezed water when the
temperature of the squeezed water has fallen below the heater
safety water level, and uniformly distributing the heated water
throughout the laundry, thereby accomplishing uniform washing
efficiency.
[0079] 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.
* * * * *