U.S. patent application number 10/584817 was filed with the patent office on 2007-06-14 for method for washing laundry in a process-controlled household washing machine.
This patent application is currently assigned to BSH Bosch und Hausgerate GmbH. Invention is credited to Gundula Czyzewski, Christine Meissner, Ingo Schulze, Martina Wobkemeier.
Application Number | 20070130699 10/584817 |
Document ID | / |
Family ID | 34683904 |
Filed Date | 2007-06-14 |
United States Patent
Application |
20070130699 |
Kind Code |
A1 |
Czyzewski; Gundula ; et
al. |
June 14, 2007 |
Method for washing laundry in a process-controlled household
washing machine
Abstract
The washing process W does not immediately begin with a heating
phase t.sub.IK-t.sub.OS at the beginning of a wash program with an
untypically cold supply of water when a heating device is turned
on, but rather once a delay phase D has elapsed. Said washing
process ends after a post-wash phase without adding any heat energy
once a defined constant time t.sub.EK-t.sub.OK has elapsed after
the delay phase. The temperature of the water or lye at the end of
or after the end of the period during which water is added F is
determined. If the determined temperature is less than a standard
value S for the amount of water which has freshly run into the lye
container prior to the beginning of the washing process W, the
heating device is turned on and the beginning of the washing
process is postponed according to a defined duration of time D.
Inventors: |
Czyzewski; Gundula; (Berlin,
DE) ; Meissner; Christine; (Berlin, DE) ;
Schulze; Ingo; (Panketal, DE) ; Wobkemeier;
Martina; (Berlin, DE) |
Correspondence
Address: |
BSH HOME APPLIANCES CORPORATION;INTELLECTUAL PROPERTY DEPARTMENT
100 BOSCH BOULEVARD
NEW BERN
NC
28562
US
|
Assignee: |
BSH Bosch und Hausgerate
GmbH
Carl-Wery-Strasse
Munich
DE
81739
|
Family ID: |
34683904 |
Appl. No.: |
10/584817 |
Filed: |
December 28, 2004 |
PCT Filed: |
December 28, 2004 |
PCT NO: |
PCT/EP04/53720 |
371 Date: |
June 27, 2006 |
Current U.S.
Class: |
8/158 |
Current CPC
Class: |
D06F 33/36 20200201;
D06F 2105/28 20200201; D06F 2204/04 20130101; D06F 2103/16
20200201; D06F 34/24 20200201; D06F 2202/04 20130101; D06F 35/006
20130101; D06F 2103/52 20200201 |
Class at
Publication: |
008/158 |
International
Class: |
D06F 35/00 20060101
D06F035/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 29, 2003 |
DE |
103 61 406.0 |
Claims
1-5. (canceled)
6. A method for washing laundry in a process-controlled household
washing machine comprising a wash liquid container for receiving
laundry and wash liquid intended for washing the laundry, wherein a
heating device and a temperature sensor are attached, wherein water
for washing is poured into the wash liquid container during a
filling phase and the temperature sensor delivers signals for the
respective temperature of the water or the wash liquid to the
process control system during the washing phase and said process
control system derives commands for controlling the heating device
for heating the wash liquid from the temperature signals and
wherein the typical washing process runs at a temperature of the
water or the wash liquid at the level of a standard value with a
heating phase which begins with switching on the device and a
post-wash phase without adding further heat energy, and lasts for a
defined constant time from the beginning of switching on the
heating device until the end of the post-wash phase, wherein: the
temperature of the water or the wash liquid is determined at or
after the end of the filling with water; that at a determined
temperature of less than a standard value for the amount of water
which has freshly run into the wash liquid container before the
beginning of the washing process the heating device is switched on;
and that the beginning of the washing process is delayed by a
defined time interval (t.sub.OK-t.sub.0S) but from there on lasts
the same time as the typical washing process.
7. The method according to claim 6, wherein the temperature is
first determined during the filling with water or wash liquid and
before or during switching off the heating device.
8. The method according to claim 6, wherein the standard value lies
in the range of 10.degree. C. to 15.degree. C.
9. The method according to claim 6, wherein the time interval
(t.sub.OK-t.sub.0S) is defined by reaching the standard value.
10. The method according to claim 6, wherein the time interval
(t.sub.OK-t.sub.0S) has a pre-defined length.
11. A method for washing laundry in a washing machine comprising a
process control system for controlling operation of the washing
machine, a wash liquid container for receiving laundry and water, a
heating device for heating the water within the wash liquid
container, and a temperature sensor for detecting the temperature
of the water, the method comprising the acts of: providing wash
liquid to the wash liquid container during a during a filling
phase; detecting an initial temperature of the water with the
temperature sensor; activating the heating device to heat the water
during a heating phase; performing a delay phase if the temperature
of the water is below a pre-determined standard value, the delay
phase continuing until the temperature of the water reaches the
standard value; performing a washing phase and continuing the wash
phase for a pre-determined period of time; turning off the heating
device when the temperature of the water reaches a pre-determined
washing temperature.
12. The method according to claim 11, wherein the duration of the
washing phase has a pre-defined length.
13. The method according to claim 12, wherein the duration of the
delay phase is variable in response to the period of time required
for the temperature of the water to reach the standard value.
14. The method according to claim 11, wherein the standard value is
between about 10.degree. C. to 15.degree. C.
Description
[0001] The invention relates to a method for washing laundry in a
process-controlled household washing machine comprising a wash
liquid container for receiving laundry and wash liquid intended for
washing the laundry, wherein or whereon a heating device and a
temperature sensor are attached, wherein water for washing is
poured into the wash liquid container during a filling phase and
the temperature sensor delivers signals for the respective
temperature of the water or the wash liquid to the process control
system during the washing phase and said process control system
derives commands for controlling the heating device for heating the
wash liquid from the temperature signals and wherein the washing
process runs with a heating phase which begins with switching on
the heating device and a post-wash phase at largely the same
temperature, and lasts for a defined constant time from the
beginning of switching on the heating device until the end of the
post-wash phase.
[0002] Washing machines of the type specified initially have been
manufactured for many years by the proprietor of this patent and
form a well-known prior art. The background for defining the
duration of the washing process by specifying it from the beginning
of the heating phase and the end of the post-wash phase is to
ensure uniformly good washing results as a result of the time
factor of the so-called Sinnersch cycle which prescribes a sum
which is always the same for the factors temperature, time,
mechanics and chemistry, remaining constant for the pure washing
process.
[0003] Now, however, under extreme conditions the temperature of
the intake water is no longer within the postulated frame which
assumes an inlet temperature of about 12.degree. C. Fluctuations of
.+-.3.degree. are of little importance in this connection. Under
extreme conditions, however, the predicted inlet temperature may
specifically have deviated further downwards so that inlet
temperatures of, for example, 5.degree. C. are possible. Then
however, the heating phase is extended so significantly that the
subsequent post-wash phase is too short because of the entire
washing process being the same length. Then the mechanics factor
has the same fraction but the temperature factor is reduced because
the temperature is too low over a large fraction of the washing
process (in the heating phase).
[0004] In order to remedy this and guarantee that the temperature
factor always has the same fractions, EP 0 859 304 B1 has proposed
that the input of thermal energy should be monitored and always
kept the same under otherwise the same conditions.
[0005] At the same time, for washing household laundry the laundry
in a washing machine is washed in different program steps using a
washing solution at varying temperature. For this purpose, the
laundry is inserted in a laundry drum rotatably mounted in a wash
liquid container and the washing solution (water with added
cleansing agent) is supplied to the wash liquid container or the
laundry drum. Different temperatures can be set in the washing
program, usually ranging from tap water temperature (cold) up to
95.degree. C. for a boil wash. The washing machine has a heating
device for heating the supplied water or the washing solution to
the set temperature. Mechanical temperature sensors such as, for
example, liquid expansion sensors or bimetallic sensors or
electronic temperature sensors such as thermistors (NTC resistors)
are arranged in the washing container to regulate the temperature
of the washing solution.
[0006] The known method for adjusting the temperature of the
washing solution in the washing process provides that, as usual,
the temperature of the washing solution is regulated between a
maximum and a minimum value for a pre-defined regulating interval,
during the regulation process the sum of the thermal energy
supplied since the beginning of this regulating process should be
determined continuously and the supply of thermal energy should be
interrupted if the sum of the thermal energy supplied exceeds a
pre-determined process energy value. These measures however no
longer take into consideration the uniform duration of these
regulated washing processes so that on the one hand the time factor
can fluctuate and the rules of the Sinnersch cycle are no longer
taken into account. This has the result that the cleaning effect is
no longer uniformly good. On the other hand, the customer can no
longer reckon on a total process duration of the same length for
specific washing programs.
[0007] It is thus the object of the invention to ensure that in the
process described initially the influences of the temperature and
time factors involved should be guaranteed if the temperature of
the intaken water departs from the provided standard value.
[0008] According to the invention, this object is solved by the
temperature of the water or the wash liquid being determined at or
after the end of the filling with water, that at a determined
temperature of less than a standard value for the amount of water
which has freshly run into the wash liquid container before the
beginning of the washing process the heating device is switched on
and that the beginning of the washing process is delayed by a
defined time interval.
[0009] Since the beginning of the washing process, that is so that
the beginning of the guaranteed duration of the cleaning process
for the laundry can be specified automatically depending on the
initial temperature of the intaken water, the time duration for the
cleaning process is determined independently of the initial
temperature. It is thereby possible to adapt both the temperature
factor, i.e. the quantity of input thermal energy and also the time
factor to meet the requirements specified by the Sinnersch cycle.
This also means maintaining the desired duration of washing
processes under typical household conditions.
[0010] If according to an advantageous further development of the
method according to the invention, the temperature is first
determined during the filling with water or wash liquid and before
or during switching off the heating device, the duration of the
washing process can be calculated with the highest accuracy.
[0011] The standard value is best located in the range of
10.degree. C. to 15.degree. C. because the inlet temperature will
regularly lie in this range. Under extreme conditions the inlet
temperature can deviate substantially downwards, for example if the
washing machine is located in a room subjected to large temperature
fluctuations. After water having a temperature higher or lower than
the standard value has been taken in, during the subsequent course
of the filling process approximately uniformly
temperature-controlled water (e.g. at 12.degree. C.) is passed
through the cold or warm piping system exposed in the room.
However, the quantity of water which has run into the wash liquid
container will have a mixing temperature which differs
substantially (e.g. 12.degree. C.) from the standard value.
[0012] At the same time, upward deviations tend to be unharmful for
maintaining the cleaning effect even if as a result, the washing
process is carried out with an overall slightly higher input of
thermal energy with a constant effective washing time. Downward
deviations will have no harmful effects as a result of postponing
the beginning for the washing process because despite the washing
solution beginning to act on the laundry at lower temperature and
the heating phase thereby being lengthened, the duration of the
effective washing process as a whole is maintained.
[0013] According to an advantageous further development of the
invention, the time interval can be defined by reaching the
standard value. If the inlet temperature should lie below the
standard value, it is possible to precisely set the beginning of
the washing process by beginning the heating phase by switching on
the heating device and waiting until the temperature of the washing
solution has reached the standard value (e.g. 12.degree. C.). The
beginning of the washing process is only defined at this time so
that after a pre-determined time has elapsed from this time, the
post-wash phase is ended for example by pumping away the washing
solution or by adding further unheated water (cool down) to the
wash liquid container.
[0014] In another variant for an advantageous further development
of the invention, a pre-defined length is set for the duration of
the postponement of the beginning of the washing process. It can be
assumed that the deviations of the inlet temperature from the
standard value rarely have extreme values or fluctuate
substantially and a standard deviation is thus specified which is
always assumed when the determined inlet temperature deviates
downwards by a pre-determined value from the standard value. The
value of this deviation can be 3.degree. for example. If this
deviation is achieved or exceeded, a fixed pre-determined time
interval is inserted for the postponement of the beginning of the
washing process. If the total input of thermal energy and time is
then too great, the cleaning effect will at least not become
inferior to that desired. On the other hand, a loss for those
factors caused by a too-short postponement if the actual inlet
temperature should be lower than that corresponding to the
pre-determined time interval for the displacement, is only very
small and the resulting reduction in the cleaning effect would
probably no longer be measurable.
[0015] The inventive method is explained hereinafter with reference
to two diagrams shown in the drawings. In the drawings
[0016] FIG. 1 shows a temperature profile of the washing solution
as a function of the time after a water intake with typical inlet
temperature (standard value) and
[0017] FIG. 2 shows a temperature profile compared with that in
FIG. 1 after a water intake with an inlet temperature below the
standard value.
[0018] The temperature profile during washing programs in a washing
machine is typically as shown in FIG. 1. At time 0 the washing
program begins with an intake of unheated water, for example, from
a domestic water supply. The incoming water has a temperature
according to a standard value S assumed for this example, namely
15.degree. C. It is further assumed for simplification purposes
that the filling phase F is completed at time t.sub.0S. A water
level sensor not described in further detail can now, for example,
cause the closure of a switch in the circuit of the heating device.
As a result, the continuous heating of the washing solution (the
water which has flowed in has entrained washing agent from a
flushing container) begins until the target value for the set
washing temperature (e.g. 60.degree. C.) is reached. The heating
device is then switched off again and the washing solution cools
downs to a value below the target temperature, e.g. 50.degree. C.,
by the end of the washing process W which is substantially
characterised by the introduction of mechanics as a result of
rotations of the drum at intervals. The end of the washing process
W is determined by a fixed time interval t.sub.ES-t.sub.0S which is
stored in the washing program and a further supply of unheated
water is initiated at time t.sub.ES whereby a cooling phase
(so-called cool down) and the rinsing phase R begins.
[0019] If the temperature of the inflowing water differs only
slightly from the standard value S=15.degree. C., e.g. by only
3.degree., the washing process is operated further according to the
profile shown in the diagram in FIG. 1. This means that although
the initial temperature is now slightly lower than typical, the
washing process W now begins with a lower temperature so that the
heating phase t.sub.1S-t.sub.0S now takes a longer time than when
beginning at 15.degree. C., which time is now lost to part of the
washing process W wherein the washing solution cools down again
until the end t.sub.ES. This guarantees that the time factor is
observed. However, the time interval within the washing process W
in which the laundry is washed with a temperature of the washing
solution at least in the vicinity of the target temperature is
shortened compared with the typical profile shown.
[0020] FIG. 2 shows an example wherein considerably cooler water
(e.g. only 6.degree. C. warm water) flows in at the beginning of a
washing program. For comparison with the typical profile, the curve
from FIG. 1 is also plotted as thin lines. Here the heating
naturally also begins after the end of the filling phase F. Unlike
in the typical profile however, the beginning of heating does not
coincide with the beginning of the washing phase W. Rather, a delay
phase D is switched on here which, as in the example shown, can
either last until the temperature of the washing solution being
heated has reached the standard value S or has a pre-determined
duration which is approximately of similar length to the duration
shown in the example.
[0021] At the end of the delay phase D, however, the washing
process W begins again with a pre-determined time interval
t.sub.EK-t.sub.0K which is the same length as t.sub.ES-t.sub.0S.
This ensures that in any case of the inlet temperature in the
washing process, the time factor cannot be too short.
* * * * *