U.S. patent application number 11/184962 was filed with the patent office on 2006-08-03 for washing machine and suds sensing method thereof.
This patent application is currently assigned to SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to Chang Joo Chai, Yo Chul Ha.
Application Number | 20060168740 11/184962 |
Document ID | / |
Family ID | 35717551 |
Filed Date | 2006-08-03 |
United States Patent
Application |
20060168740 |
Kind Code |
A1 |
Ha; Yo Chul ; et
al. |
August 3, 2006 |
Washing machine and suds sensing method thereof
Abstract
A washing machine and a suds sensing method thereof, in which a
generation of suds is precisely sensed using discharge
characteristics of suds in a water discharging operation. The suds
sensing method of a washing machine includes determining whether a
water level reaches a water discharge completion level in a
predetermined water discharging time in a water discharging
operation, determining whether the water level reaches a suds
sensing level in a predetermined suds discharging time by
controlling a drainage device such that the drainage device is
turned on and off when the water level does not reach the water
discharge completion level in the predetermined water discharging
time, and sensing the suds by controlling the drainage device such
that the drainage device is turned on and off in a predetermined
range of the water level when the water level reaches the suds
sensing level in the predetermined suds discharging time.
Inventors: |
Ha; Yo Chul; (Suwon-Si,
KR) ; Chai; Chang Joo; (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: |
35717551 |
Appl. No.: |
11/184962 |
Filed: |
July 20, 2005 |
Current U.S.
Class: |
8/158 ; 68/12.02;
68/12.05; 68/12.21; 68/208; 8/159 |
Current CPC
Class: |
D06F 2103/20 20200201;
D06F 34/22 20200201; D06F 2103/18 20200201; D06F 33/00 20130101;
D06F 34/08 20200201; D06F 33/42 20200201; D06F 2105/08 20200201;
D06F 39/083 20130101; D06F 39/06 20130101; D06F 2103/38
20200201 |
Class at
Publication: |
008/158 ;
008/159; 068/012.02; 068/012.05; 068/012.21; 068/208 |
International
Class: |
D06F 33/02 20060101
D06F033/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 2, 2005 |
KR |
2005-9573 |
Claims
1. A suds sensing method of a washing machine comprising:
discharging water by determining whether a water level reaches a
water discharge completion level in a predetermined water
discharging time in a water discharging operation; discharging suds
by controlling a drainage device such that the drainage device is
turned on and off when the water level does not reach the water
discharge completion level in the predetermined water discharging
time; and sensing the suds by detecting a water level varying
according to the turning on and off of the drainage device.
2. The suds sensing method as set forth in claim 1, wherein the
predetermined water discharging time is set to a water discharge
completion time, which is time taken to discharge the maximum
amount of the water during operations of the washing machine.
3. The suds sensing method as set forth in claim 1, wherein, in the
discharging of the suds, the drainage device is controlled such
that the drainage device is turned on and off during a
predetermined time to distinguish between the suds and foreign
substances in the drainage device.
4. The suds sensing method as set forth in claim 3, wherein the
predetermined time is a suds discharging time, which is time taken
to discharge the suds according to the turning on and off of the
drainage device.
5. The suds sensing method as set forth in claim 4, wherein the
suds discharging time is determined by a volume of the washing
machine and a capacity of the drainage device.
6. The suds sensing method as set forth in claim 1, wherein, in the
sensing of the suds, it is determined that the water level reaches
a suds sensing level in a predetermined suds discharging time
according to the turning on and off of the drainage device.
7. The suds sensing method as set forth in claim 6, wherein the
drainage device is controlled such that the drainage device is
turned on and off in a predetermined range of the water level to
distinguish between the suds and the foreign substances in the
drainage device, when the water level reaches the suds sensing
level in the predetermined suds discharging time.
8. The suds sensing method as set forth in claim 7, wherein the
predetermined range of the water level is set to lower than the
suds sensing level, and comprises an upper limit and a lower limit
for controlling the drainage device such that the drainage device
is turned on/off.
9. The suds sensing method as set forth in claim 7, wherein a
number of suds-sensing times according to the turning on and off of
the drainage device is sensed, and it is determined that suds are
generated when the number of suds-sensing times is more than a
designated number.
10. The suds sensing method as set forth in claim 1, wherein, in
the discharging of the suds, the drainage device is controlled such
that the drainage device is turned on/off in a predetermined range
of the water level during a predetermined time to distinguish
between the suds and the foreign substances in the drainage
device.
11. The suds sensing method as set forth in claim 10, wherein the
predetermined time is a suds sensing time, which is time taken to
sense the suds according to the turning on and off of the drainage
device.
12. A suds sensing method of a washing machine comprising:
determining whether a water level reaches a water discharge
completion level in a predetermined water discharging time in a
water discharging operation; determining whether the water level
reaches a suds sensing level in a predetermined suds discharging
time, by controlling a drainage device such that the drainage
device is turned on and off when the water level does not reach the
water discharge completion level in the predetermined water
discharging time; and sensing the suds by controlling the drainage
device such that the drainage device is turned on and off in a
predetermined range of the water level when the water level data
reaches the suds sensing level in the predetermined suds
discharging time.
13. The suds sensing method as set forth in claim 12, wherein the
predetermined range of the water level is set lower than the suds
sensing level, and comprises an upper limit and a lower limit for
controlling the drainage device such that the drainage device is
turned on and off.
14. The suds sensing method as set forth in claim 13, wherein a
number of suds-sensing times according to the turning on and off of
the drainage device is sensed, and it is determined that suds are
generated when the number of suds-sensing times is more than a
designated number.
15. A washing machine having a drainage device for discharging
washing water and a detergent, comprising: a water level sensing
unit to detect a water level varying according to the operation of
the drainage device; and a control unit to determine whether the
water level reaches a water discharge completion level in a
predetermined water discharging time, discharging suds by
controlling the drainage device such that the drainage device is
turned on and off when the water level does not reach the water
discharge completion level, and to sense the suds by detecting the
variation in the water level.
16. The washing machine as set forth in claim 15, wherein the
control unit determines whether the water level reaches a suds
sensing level in a predetermined suds discharging time according to
the turning on and off of the drainage device, and controls the
drainage device such that the drainage device is turned on and off
in a predetermined range of the water level when the water level
reaches the suds sensing level.
17. A method for sensing suds in a washing machine having a
drainage pump, the method comprising: discharging water from the
washing machine after a washing or rinsing operation has been
performed by turning on the drainage pump; sensing a generation of
suds by detecting whether a water level of the washing machine has
reached a water discharge completion level in a predetermined time
period; preliminary suds sensing by controlling the turning on and
off of the drainage pump to distinguish between the suds and
foreign substances in the drainage pump, when the water level does
not reach the water discharge completion level in the predetermined
time period; main suds sensing for controlling the turning on and
off of the drainage pump, to distinguish between the suds and the
foreign substances in the drainage pump, when the water level
reaches the suds sensing level in the predetermined suds
discharging time during the performing of the preliminary suds
sensing; and eliminating the suds by repeatedly performing the
rinsing operation, a discharging operation and a dehydrating
operation of the washing machine.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Patent
Application No. 2005-9573, filed Feb. 2, 2005, in the Korean
Intellectual Property Office, the disclosure of which is
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method for sensing suds
in a washing machine, and more particularly, to a washing machine,
which senses a generation of suds using discharge characteristics
of the suds, and suds sensing method thereof.
[0004] 2. Description of the Related Art
[0005] Generally, a conventional drum-type washing machine is an
apparatus for washing laundry in a cylindrical rotary drum by
lifting the laundry and then dropping the laundry when the rotary
drum is rotated. Compared to a conventional pulsator-type washing
machine, the drum-type washing machine has a longer washing time,
but minimizes damage to the laundry and has a low water consumption
rate, thus being increasingly demanded.
[0006] In the conventional drum-type washing machine, when a user
uses a large amount of a detergent exceeding a reference amount or
a detergent which lathers well, a large amount of suds are
generated by a detergent component remaining in laundry in a
dehydrating operation after a discharging operation. The suds are
leaked to the front surface of the washing machine (for example,
through a detergent inlet), or serves as a load obstructing the
driving of a motor, thereby causing a difficulty in reaching a
normal dehydration rpm (revolutions per minute).
[0007] In order to solve the above problem, Korean Patent
Publication No. 10-0282343 discloses a method for sensing the
generation of suds and eliminating the suds, where a washing
machine determines whether suds are generated by sensing whether a
load applied to a motor is increased, and, when a large amount of
the suds are generated, eliminates the suds through a suds
eliminating process in which a water supplying operation, a rinsing
operation, and a water discharging operation are repeated.
[0008] In the conventional suds sensing method, there is a high
probability of an error due to a variation of an output of the
motor according to a variation in an amount of laundry to be washed
or a variation in voltage power. Accordingly, the above
conventional suds sensing method is disadvantageous in that the
washing performance of the washing machine is deteriorated or
electricity is wasted due to the error in precisely sensing the
suds.
SUMMARY OF THE INVENTION
[0009] Accordingly, it is an aspect of the present invention to
provide a washing machine, which precisely senses the generation of
suds using discharging characteristics of the suds, and a suds
sensing method thereof.
[0010] Additional aspects and/or advantages of the invention 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 invention.
[0011] It is another aspect of the present invention to provide a
washing machine, which precisely senses whether a discharge pump
malfunctions or foreign substances are present in the discharge
pump, and whether suds are generated according to a variation in a
water level during a water discharging operation of the washing
machine, and a suds sensing method thereof.
[0012] The foregoing and/or other aspects of the present invention
are achieved by providing a suds sensing method of a washing
machine including discharging water by determining whether a water
level reaches a water discharge completion level in a predetermined
water discharging time in a water discharging operation,
discharging suds by controlling a drainage device such that the
drainage device is turned on and off when the water level does not
reach the water discharge completion level in the predetermined
water discharging time, and sensing the suds by detecting a water
level varying according to the turning on and off of the drainage
device.
[0013] The predetermined water discharging time may be set to a
water discharge completion time, which is time taken to discharge a
maximum amount of the water during operations of the washing
machine.
[0014] When discharging the suds, the drainage device may be
controlled such that the drainage device is turned on and off
during a predetermined time to distinguish between the suds and
foreign substances in the drainage device.
[0015] The predetermined time may be a suds discharging time, which
is time taken to discharge the suds according to the turning on and
off of the drainage device, and the suds discharging time may be
determined by a volume of the washing machine and a capacity of the
drainage device.
[0016] Further, it may be determined that the water level data
reaches a suds sensing level in a predetermined suds discharging
time according to the turning on and off of the drainage
device.
[0017] The drainage device is controlled such that the drainage
device is turned on and off in a predetermined range of the water
level to distinguish between the suds and foreign substances in the
drainage device, when the water level reaches the suds sensing
level in the predetermined suds discharging time.
[0018] The predetermined range of the water level may be set lower
than the suds sensing level, and include an upper limit and a lower
limit for controlling the drainage device such that the drainage
device is turned on and off.
[0019] A number of suds-sensing times according to the turning on
and off of the drainage device may be sensed, and it may be
determined that suds are generated when the number of suds-sensing
times is more than a designated number.
[0020] When discharging the suds, the drainage device is controlled
such that the drainage device is turned on and off in a
predetermined range of the water level during a predetermined time
to distinguish between the suds and foreign substances in the
drainage device.
[0021] The predetermined time may be a suds sensing time, which is
taken to sense the suds according to the turning on and off of the
drainage device.
[0022] It is another aspect of the present invention to provide a
suds sensing method of a washing machine including determining
whether a water level reaches a water discharge completion level in
a predetermined water discharging time in a water discharging
operation, determining whether the water level reaches a suds
sensing level in a predetermined suds discharging time by
controlling a drainage device such that the drainage device is
turned on and off, when the water level does not reach the water
discharge completion level in the predetermined water discharging
time, and sensing the suds by controlling the drainage device such
that the drainage device is turned on and off in a predetermined
range of the water level when the water level reaches the suds
sensing level in the predetermined suds discharging time.
[0023] It is another aspect of the present invention to provide a
washing machine having a drainage device for discharging washing
water and a detergent, including a water level sensing unit to
detect a water level varying according to the operation of the
drainage device, and a control unit to determine whether the water
level reaches a water discharge completion level in a predetermined
water discharging time, to discharge suds by controlling the
drainage device such that the drainage device is turned on and off
when the water level does not reach the water discharge completion
level, and to sense the suds by detecting a variation in the water
level.
[0024] The control unit may determine whether the water level
reaches a suds sensing level in a predetermined suds discharging
time according to the turning on and off of the drainage device,
and control the drainage device such that the drainage device is
turned on and off in a predetermined range of the water level when
the water level reaches the suds sensing level.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] 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:
[0026] FIG. 1 is a sectional view of a washing machine of the
present invention;
[0027] FIG. 2 is a block diagram of a suds sensing apparatus of a
washing machine in accordance with an embodiment of the present
invention;
[0028] FIG. 3 is a flow chart illustrating a suds sensing method of
the washing machine in accordance with an embodiment of the present
invention;
[0029] FIG. 4 is a flow chart illustrating an operation of
discharging water in the suds sensing method of FIG. 3;
[0030] FIG. 5 is a graph illustrating the operation of discharging
water of FIG. 4;
[0031] FIG. 6 is a flow chart illustrating an operation of
preliminary suds sensing in the suds sensing method of FIG. 3;
[0032] FIG. 7 is a graph illustrating the operation of preliminary
suds sensing of FIG. 6;
[0033] FIG. 8 is flow chart illustrating an operation of main suds
sensing of the suds sensing method of FIG. 3; and
[0034] FIG. 9 is a graph illustrating the operation of main suds
sensing of FIG. 8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] Reference will now be made in detail to the embodiment of
the present invention, an example of which is illustrated in the
accompanying drawings, wherein like reference numerals refer to
like elements throughout. The embodiments are described below to
explain the present invention by referring to the figures.
[0036] FIG. 1 is a sectional view of a washing machine of an
embodiment of the present invention.
[0037] In FIG. 1, the washing machine of the present invention
comprises a drum-type tub 11 installed in a main body 10 for
containing washing water therein, and a rotary drum 12 rotatably
installed in the tub 11.
[0038] The tub 11 slopes toward an installation ground of the
washing machine at a designated angle (.alpha.) so that a front
surface 11a of the tub 11, through which an opening 11b is formed,
is located at a position higher than that of a rear surface 11c of
the tub 11. The rotary drum 12 installed in the tub 11 has a same
structure as that of the tub 11, so that a front surface 12a of the
rotary drum 12, through which an opening 12b is formed, is located
at a position higher than that of a rear surface 12c of the rotary
drum 12.
[0039] That is, the front surface 12a of the rotary drum 12
provided with the opening 12b slantedly ascends forward such that a
rotary central line A of the rotary drum 12 meets the installation
ground of the washing machine at the designated angle (.alpha.).
Since a rotary shaft 13 connected to a central portion of the rear
surface 12c of the rotary drum 12 is rotatably supported by the
central portion of the rear surface 11c of the tub 11, the rotary
drum 12 is rotated in the tub 11.
[0040] A plurality of through holes 12d are formed through the
cylindrical surface of the rotary drum 12, and a plurality of
lifters 14 for lifting and dropping the laundry when the rotary
drum 12 is rotated are installed on the inner surface of the rotary
drum 12.
[0041] A motor 15, serving as a driving device for rotating the
rotary shaft 13 connected to the rotary drum 12 so that the washing
machine performs washing, rinsing, and dehydrating operations, is
installed outside the rear surface 11c of the tub 11. A heater 16
for heating washing water supplied to an inside of the tub 11 is
installed in a lower part of the tub 11.
[0042] The motor 15 comprises a stator 15a fixed to the rear
surface 11c of the tub 11, a rotor 15b rotatably disposed outside
the stator 15a, and a rotary plate 15c connecting the rotor 15b and
the rotary shaft 13.
[0043] An opening 17b is formed through a front surface of the main
body 10 at a position corresponding to the opening 12b of the
rotary drum 12 and the opening 11b of the tub 11 so that the
laundry is inserted into or taken out of the rotary drum 12 through
the opening 17b, and a door 17 for opening and closing the opening
17b is installed on the front surface of the main body 10.
[0044] A detergent supply device 18 for supplying a detergent and a
water supply device 20 for supplying washing water are installed
above the tub 11, and a drainage device 19 including a drainage
pipe 19a, a drainage valve 19b and a drainage pump 19c for
discharging water from the inside of the tub 11 to an outside of
the tub 11 is installed below the tub 11.
[0045] An inside of the detergent supply device 18 is divided into
a plurality of spaces, and the detergent supply device 18 is
installed in the front surface of the main body 10 so that a user
can easily put the detergent and a softener into the spaces of the
detergent supply device 18.
[0046] The water supply device 20 comprises a water supply pipe 21
for supplying water to the tub 11, and a water supply valve 22
installed in the water supply pipe 21 for controlling a supply of
the water by the water supply pipe 21. Here, the water supply pipe
21 is connected to the detergent supply device 18 so that water is
supplied from the outside to the detergent supply device 18. A
connection pipe 23 is installed between the detergent supply device
18 and the tub 11 so that the water, passed through the detergent
supply device 18, is supplied to the tub 11, and a water supply
nozzle 24 is installed at an outlet of the connection pipe 23. The
above structure causes the water supplied to the inside of the tub
11 to pass through the detergent supply device 18, thereby causing
the detergent in the detergent supply device 18, which dissolves in
water, to be supplied to the tub 11.
[0047] FIG. 2 is a block diagram of a suds sensing apparatus of a
washing machine in accordance with an embodiment of the present
invention. The suds sensing apparatus comprises a signal input unit
100, a temperature sensing unit 110, a water level sensing unit
120, a control unit 130, and an operating unit 140.
[0048] The signal input unit 100 inputs operating data, such as a
washing operation, a washing temperature, a dehydration rpm, and
whether a rinsing operation is added, which are selected by a user,
to the control unit 130. The temperature sensing unit 110 senses
the temperature of the washing water.
[0049] The water level sensing unit 120 senses a level of the
washing water. Particularly, the water level sensing unit 120
senses data associated with a water level varying according to an
amount of the washing water or suds discharged, and inputs the
sensed data to the control unit 130.
[0050] The control unit 130 comprises a microcomputer for
controlling an operation of the discharge pump 19c according to a
variation in the water level data inputted from the water level
sensing unit 120 and sensing a generation of suds, a malfunction of
the discharge pump 19c, or a presence of foreign substances in the
discharge pump 19c. The control unit 130 comprises a timer for
counting an operating (on/off) time of the discharge pump 19c, and
a table storing data, such as washing operations, capacities of the
washing machine, and predetermined times and predetermined water
levels according to capacities of the discharge pump 19c.
[0051] The control unit 130 senses the generation of suds by
detecting whether the water level reaches a water discharge
completion level in a discharge completion time predetermined when
discharging the water. The control unit 130 then senses the
generation of suds by detecting whether the water level reaches
suds sensing water level in suds discharging time predetermined by
rapidly discharging suds in sensing of preliminary suds performed
to discriminate between the suds and foreign substances in the
discharge pump 19c when the water level does not reach the water
discharge completion level in the predetermined discharge
completion time. Further, the control unit 130 senses the
generation of suds by detecting whether a number of suds-sensing
times is more than a designated number in suds sensing time
predetermined during the operation of the main suds sensing
performed to distinguish between the suds and the foreign
substances in the discharge pump 19c when the water level reaches
the suds sensing water level in the predetermined suds discharging
time.
[0052] The driving unit 140 drives the motor 15, the heater 16, the
drainage valve 19b, the drainage pump 19c, and the water supply
valve 22 based on an operation control signals of the control unit
130.
[0053] Hereinafter, an operation of the above washing machine and
the suds sensing method thereof will be described.
[0054] FIG. 3 is a flow chart illustrating the suds sensing method
of the washing machine of the present invention. The suds sensing
method of the present invention is exhibited by suds sensing
algorithm in a water discharging operation, which may be performed
after a washing operation or after a rinsing operation.
[0055] In operation 100, when discharging water after the washing
or rinsing operation is started, the generation of suds is sensed
by detecting whether the water level reaches a water discharge
completion level in a discharge completion time (T.sub.end; i.e.,
the time for discharging a maximum amount of water according to
washing operations) predetermined in the normal water discharging
operation, in which the drainage pump 19c is turned on.
[0056] From operation 100, the process moves to operation 200,
where preliminary suds sensing for controlling the turning on and
off of the drainage pump 19c to distinguish between the suds and
the foreign substances in the drainage pump 19c is performed, when
the water level does not reach the water discharge completion level
in the discharge completion time (T.sub.end), thereby more rapidly
discharging suds. Therefore, in the preliminary suds sensing
operation 200, it is determined whether the water level reaches a
suds sensing level in a predetermined suds discharging time
(T.sub.pre).
[0057] The preliminary suds sensing operation 200 serves to
determine whether the reason that the water level does not reach
the water discharge completion level in the discharge completion
time (T.sub.end) is caused by the generation of suds, or the
malfunction of drainage pump 19c and foreign substances in the
drainage pump 19c.
[0058] From operation 200, the process moves to operation 300,
where main suds sensing for setting a designated water level and
controlling the turning on and off of the drainage pump 19c to
distinguish between the suds and the foreign substances in the
drainage pump 19c is performed, when the water level reaches the
suds sensing level in the predetermined suds discharging time
(T.sub.pre) in the preliminary suds sensing operation 200. Thereby,
in operation 300, it is determined whether the number (N.sub.c) of
suds-sensing times is more than a designated number in a
predetermined suds sensing time (T.sub.main).
[0059] The main suds sensing operation serves to determine whether
the reason that the water level does not reach the suds sensing
level in the predetermined suds discharging time (T.sub.pre) is
caused by the generation of suds or foreign substances in a small
amount present in the drainage pump 19c.
[0060] When the number (N.sub.c) of suds-sensing times is more than
the designated number in the predetermined suds sensing time
(T.sub.main) in operation 300, it is determined that suds is
generated, and the process moves to operation 400, where a suds
eliminating operation is performed.
[0061] The suds eliminating operation is performed by a general
process in which water is re-supplied to the tub 11 and a rinsing
operation by agitating the motor 15, a discharging operation and a
dehydrating operation are repeated.
[0062] Hereinafter, with reference to FIGS. 4 and 5, the water
discharging operation 100 will be described in detail.
[0063] A time (T) taken to discharge water in a course requiring
the maximum amount of water is measured, and a time (T.times.2)
obtained by doubling the time (T) is set to the discharge
completion time (T.sub.end; approximately 1 minute).
[0064] In operation 110, the drainage pump 19c is turned on to
normally discharge washing water, from operation 110 the process
moves to operation 120, where a normal water discharging time
(T.sub.cn) according to the turning on of the drainage pump 19c is
measured.
[0065] From operation 120, the process moves to operation 130,
where it is determined whether the measured normal water
discharging time (T.sub.cn) is less than the predetermined
discharge completion time (T.sub.end). When the measured normal
water discharging time (T.sub.cn) is less than the predetermined
water discharge completion time (T.sub.end) in operation 130, the
process moves to operation 140, where it is determined whether the
water level reaches the predetermined water discharge completion
level (the minimum water level for determining a point of time the
discharge of water is completed or the water level for performing
the next operation after the operation of the drainage pump) by the
discharging operation.
[0066] When the water level reaches the water discharge completion
level in the predetermined water discharge completion time
(T.sub.end), andt suds are not generated, as shown in FIG. 5, the
discharge of water is generally completed in the water discharge
completion time (T.sub.end), from operation 140, the process moves
to operation 150 where the dehydrating operation is performed.
[0067] However, when suds are generated or foreign substances are
present in the drainage pump 19c, the water level ddoes not reach
the predetermined water discharge completion level in the water
discharge completion time (T.sub.end).
[0068] Accordingly, when the water level does not reach the water
discharge completion level in the predetermined water discharge
completion time (T.sub.end), the preliminary suds sensing operation
200 for controlling the turning on and off of the drainage pump 19c
to distinguish between the suds and the foreign substances in the
drainage pump 19c is performed.
[0069] Hereinafter, with reference to FIGS. 6 and 7, operation 200,
the sensing of the preliminary suds will be described in
detail.
[0070] The main objective of preliminary suds sensing in operation
200 is to distinguish between the suds and the foreign substances
in the drainage pump 19c before main suds sensing in operation 300
is performed.
[0071] The minimum time taken to reach the suds sensing level
according to turning-on/off of the drainage pump 19c is set to the
suds discharging time (T.sub.pre; approximately 2 minutes), and the
suds discharging time (T.sub.pre) is determined by the volume of
the washing machine and the capacity of the drainage pump 19c.
[0072] From operation 200 the process moves to operation 210 where
the drainage pump 19c is turned on and off so as to rapidly
discharge the suds, and a preliminary suds sensing time (T.sub.cp)
according to the turning on and off of the drainage pump 19c is
measured.
[0073] From operation 220 the process moves to operation 230, where
It is determined whether the measured preliminary suds sensing time
(T.sub.cp) is less than the suds discharging time (T.sub.pre). When
the measured preliminary suds sensing time (T.sub.cp) is less than
the suds discharging time (T.sub.pre) in operation 230, the process
moves to operation 240, where it is determined whether the water
level data reaches the predetermined suds sensing level (the
minimum water level for discriminating between the suds and the
foreign substances in the drainage pump or the water level in an
amount of approximately 20% of that of the washing water) by
discharging the suds.
[0074] That is, as shown in FIG. 7, the foreign substances in the
drainage pump 19c are discharged at a designated angle even when
the drainage pump 19c is intermittently turned on/off. On the other
hand, as shown in FIG. 7, the suds are discharged at a higher speed
when the drainage pump 19c is intermittently turned on/off compared
to when the drainage pump 19c is turned on, thereby allowing the
water level data to reach the suds sensing level in the suds
discharging time (T.sub.pre).
[0075] Accordingly, when the water level data reaches the suds
sensing level in the predetermined suds discharging time
(T.sub.pre), in operation 300, the main suds sensing operation for
setting a designated water level and controlling the turning on and
off of the drainage pump 19c, to more precisely distinguish between
the suds and the foreign substances in the drainage pump 19c, is
performed.
[0076] However, when foreign substances are present in the drainage
pump 19c, the water level data does not reach the predetermined
suds sensing level in the suds discharging time (T.sub.pre).
[0077] When the water level data does not reach the suds sensing
level in the predetermined suds discharging time (T.sub.pre), in
operation 100, the discharging of normal water, in which the
drainage pump 19c is turned on to discriminate between the presence
of foreign substances in the drainage pump 19c and the malfunction
of the drainage pump 19c is performed.
[0078] When the drainage pump 19c malfunctions, the above-described
procedure is repeated and the discharge of water is not achieved
for a time set by a designer (discharge error time), thereby
causing a discharge error.
[0079] Hereinafter, with reference to FIGS. 8 and 9, operation 300,
the main suds sensing operation will be described in detail.
[0080] The main suds sensing operation is performed to distinguish
between any suds and foreign substances (in a small amount) in the
drainage pump 19c passed by the preliminary suds sensing performed
in operation 200, thereby more precisely sensing only the suds.
[0081] In order to more precisely sense the suds, a designated
water level range (the maximum and minimum water levels of a
designated range lower than the suds sensing level) is set, and a
time limit when the number (N.sub.c) of suds-sensing times
according to the turning-on/off of the drainage pump 19c is more
than a designated number (N.sub.s); the number for determining that
the generation of the suds is secured) is set to suds sensing time
(T.sub.main). The suds sensing time (T.sub.main) is determined by
the volume of the washing machine and the capacity of the drainage
pump 19c.
[0082] In operation 310, the drainage pump 19c is turned on so as
to discharge the suds (S310), and from operation 310, the process
moves to operation 320 where a main suds sensing time (T.sub.cm) is
measured.
[0083] In operation 330, the water level data, which is lowered by
the turning-on of the drainage pump 19c, is sensed, and it is
determined whether the sensed water level data reaches the
predetermined minimum water level. From operation 330, the process
moves to operation 340 where then the water level data reaches the
minimum water level, the drainage pump 19c is turned off.
[0084] When the suds are generated, as shown in FIG. 9, the water
level rises again by turning the drainage pump 19c off. From
operation 340, the process moves to operation 350 where the number
of water level-rising times is set and the number (N.sub.c) of
suds-sensing times is measured.
[0085] From operation 350, the process moves to operation 360 where
the water level data, which rises by the turning-off of the
drainage pump 19c, is sensed, and it is determined whether the
sensed water level data reaches the predetermined maximum water
level. When the water level data reaches the maximum water level,
the process moves from operation 360 back to operation 310 so that
the drainage pump 19c is turned on.
[0086] As described above, in operation 370, the designated water
level range is set, the main suds sensing time (T.sub.cm) for
controlling the turning-on/off of the drainage pump 19c is less
than the predetermined suds sensing time (T.sub.main). From
operation 370, the process moves to operation 380 where when the
main suds sensing time (T.sub.cm) is less than the suds sensing
time (T.sub.main), it is determined that the measured number
(N.sub.c) of suds-sensing times is more than the predetermined
number (N.sub.s).
[0087] That is, as shown in FIG. 9, when foreign substances are
present in the drainage pump 19c, the water level is decreased at a
designated angle even when the designated water level range is set
and the drainage pump 19c is intermittently turned on/off. On the
other hand, as shown in FIG. 9, when the suds are generated, the
water level is increased again when the drainage pump 19c is turned
off during the intermittent turning-on/off of the drainage pump
19c, and thus the number (N.sub.c) of suds-sensing times is more
than the predetermined number (N.sub.s) in the limited suds sensing
time (T.sub.main).
[0088] Accordingly, when the number (N.sub.c) of suds-sensing times
is more than the predetermined number (N.sub.s) in the
predetermined suds sensing time (T.sub.main), it is determined that
suds are generated, and in operation 400, the suds eliminating
operation is performed.
[0089] However, when a small amount of foreign substances are
present in the drainage pump 19c, the number (N.sub.c) of
suds-sensing times is not more than the predetermined number
(N.sub.s) in the suds sensing time (T.sub.main).
[0090] When the number (N.sub.c) of suds-sensing times is not more
than the predetermined number (N.sub.s) in the predetermined suds
sensing time (T.sub.main), the normal water discharging step (S100)
for turning the drainage pump 19c on to discriminate between the
presence of the foreign substances in the drainage pump 19c and the
malfunction of the drainage pump 19c is performed so that the above
procedure is repeated.
[0091] As described above, the suds sensing method of the present
invention precisely senses the generation of suds using discharge
characteristics of suds in a water discharging step, and senses an
error generated due to the malfunction of the drainage pump 19c and
foreign substances present in the drainage pump 19c, thereby
preventing the malfunction of the washing machine generated by
erroneously recognizing the error generated due to the malfunction
of the drainage pump 19c and foreign substances present in the
drainage pump 19c as the generation of suds. Further, the suds
sensing method of the present invention precisely senses suds
momentarily generated in a rinsing operation.
[0092] As apparent from the above description, the present
invention provides a washing machine and suds sensing method
thereof, in which the generation of suds is precisely sensed using
discharge characteristics of suds in a water discharging operation,
thereby increasing precision in sensing suds, and performing suds
eliminating operation only when the suds are generated, thus
reducing the waste of electricity due to errors in sensing suds and
preventing the deterioration of washing performance.
[0093] Further, it is possible to precisely distinguish between the
generation of suds, the malfunction of a drainage pump, and the
presence of foreign substances in the drainage pump according to a
variation of a water level in the water discharging operation.
Therefore, the washing machine of the present invention and the
suds sensing method thereof actively cope with the generation of
errors and improve consumer's satisfaction to products.
[0094] Although an embodiment of the invention has 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.
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