U.S. patent application number 09/758334 was filed with the patent office on 2001-08-09 for method for determining the loading weight of a laundry drum and a laundry-processing machine for carrying out the method.
Invention is credited to Heyder, Reinhard, Skripper, Jorg.
Application Number | 20010011395 09/758334 |
Document ID | / |
Family ID | 7874481 |
Filed Date | 2001-08-09 |
United States Patent
Application |
20010011395 |
Kind Code |
A1 |
Skripper, Jorg ; et
al. |
August 9, 2001 |
Method for determining the loading weight of a laundry drum and a
laundry-processing machine for carrying out the method
Abstract
A method and appliance for determining the angular position of a
laundry drum and a power consumption of an electric motor driving
the drum to derive therefrom a laundry weight in the drum includes
directly driving the drum with the motor from a lower laundry
position to a raised position where a laundry center of gravity is
offset from a rotation axis to produce a loading weight from the
driving current of the electric motor measured when the raised
position is reached. Alternatively or additionally, the drum is
turned until the controller detects a power consumption of the
electric motor corresponding to a stored maximum current value to
derive a weight of the laundry from a signal corresponding to the
angular distance. The controller stores a predetermined, defined
maximum current value and measures a power consumption of the
electric motor.
Inventors: |
Skripper, Jorg; (Priort,
DE) ; Heyder, Reinhard; (Berlin, DE) |
Correspondence
Address: |
LERNER AND GREENBERG, P.A.
Post Office Box 2480
Hollywood
FL
33022-2480
US
|
Family ID: |
7874481 |
Appl. No.: |
09/758334 |
Filed: |
January 10, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09758334 |
Jan 10, 2001 |
|
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|
PCT/EP99/04983 |
Jul 14, 1999 |
|
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Current U.S.
Class: |
8/159 ;
68/12.04 |
Current CPC
Class: |
D06F 2103/24 20200201;
D06F 2105/48 20200201; D06F 2105/56 20200201; D06F 34/18 20200201;
D06F 2103/46 20200201; D06F 2103/04 20200201 |
Class at
Publication: |
8/159 ;
68/12.04 |
International
Class: |
D06F 033/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 17, 1998 |
DE |
198 32 292.5 |
Claims
We claim:
1. A method for determining a loading weight of a horizontally
mounted laundry drum, which comprises: providing a laundry drum
driven by an electric motor controlled by a controller, the laundry
drum having an axis of rotation, the laundry drum defining a
vertical plane extending through the axis of rotation; directly
driving the laundry drum with the electric motor; turning the
laundry drum with the electric motor from a 0.degree. angular
position, in which laundry is lying in a lower position in the
laundry drum, through a rotational angle until reaching an angular
position at which the laundry is in a raised position and at which
a center of gravity of the laundry is at a lateral distance from
the vertical plane; detecting the reaching of the angular position
with the controller; and producing a measured value corresponding
to a loading weight of the laundry from a driving current of the
electric motor measured when the angular position is reached.
2. The method according to claim 1, wherein the providing step is
performed by providing a washing machine having the laundry
drum.
3. The method according to claim 1, wherein the providing step is
performed by providing a washer/dryer having the laundry drum.
4. The method according to claim 1, wherein the controller is an
electronic control device.
5. The method according to claim 1, wherein the controller is an
electronic regulating device.
6. The method according to claim 1, wherein the electric motor has
at least one of power consumption signals and control signals, and
which further comprises: producing the control signals with the
controller dependent on angular positions of a rotor of the
electric motor relative to a stator of the electric motor; and
defining with the controller an angular distance through which the
laundry drum is turned from the 0.degree. angular position to reach
the angular position using fluctuations in at least one of the
power consumption signals and control signals.
7. The method according to claim 6, wherein the electric motor is
an electronically commutated d.c. motor, and which further
comprises defining the angular position using a number of
commutation steps from the 0.degree. angular position of the
laundry drum to the angular position at which the loading weight is
determined.
8. The method according to claim 1, wherein the electric motor is
an electronically controlled reluctance motor.
9. The method according to claim 1, which further comprises:
detecting an angular position of the laundry drum with a
tachogenerator as a function of angular movements of the laundry
drum to produce electric pulses; and measuring angular distance
traveled with a number of the electric pulses.
10. A method for determining a loading weight of a horizontally
mounted laundry drum, which comprises: providing a laundry drum
driven by an electric motor controlled by a controller, the laundry
drum having an axis of rotation, said drum defining a vertical
plane extending through the axis of rotation; directly driving the
laundry drum with the electric motor; storing a predetermined,
defined maximum current value in the controller; measuring a power
consumption of the electric motor; rotating the laundry drum with
the electric motor out of a 0.degree. angular position, in which
laundry lies in a lower position in the laundry drum, until the
controller detects, during the rotation of the laundry drum, a
power consumption of the electric motor corresponding to the stored
maximum current value, the rotation resulting in a raising of the
laundry into a position in which a center of gravity of the laundry
is at a lateral distance from the vertical plane, and the rotation
resulting in an angular traveling of the laundry drum to an angular
distance from the 0.degree. angular position; and producing a
measured value corresponding to a loading weight of the laundry
from a signal corresponding to the angular distance.
11. The method according to claim 10, wherein the providing step is
performed by providing a washing machine having the laundry
drum.
12. The method according to claim 10, wherein the providing step is
performed by providing a washer/dryer having the laundry drum.
13. The method according to claim 10, wherein the controller is an
electronic control device.
14. The method according to claim 10, wherein the controller is an
electronic regulating device.
15. The method according to claim 10, wherein the electric motor
transmits and receives at least one of power consumption signals
and control signals, and which further comprises: producing the
control signals with the controller dependent on angular positions
of a rotor of the electric motor relative to a stator of the
electric motor; and calculating with the controller the angular
distance through which the laundry drum is turned from the
0.degree. angular position to reach an angular position at which
the loading weight of the laundry is determined by the controller
using fluctuations in at least one of the power consumption signals
and control signals.
16. The method according to claim 15, wherein the electric motor is
an electronically commutated d.c. motor, and which further
comprises calculating the angular distance using a number of
commutation steps from the 0.degree. angular position of the
laundry drum to the angular position at which the loading weight is
determined.
17. The method according to claim 10, wherein the electric motor is
an electronically controlled reluctance motor.
18. The method according to claim 10, which further comprises:
detecting an angular position of the laundry drum with a
tachogenerator as a function of angular movements of the laundry
drum to produce electric pulses; and measuring angular distance
traveled with a number of the electric pulses.
19. A washing appliance, comprising: a stationary component; a
laundry drum rotatably mounted on said stationary component about a
horizontal axis of rotation, said drum moving through a 0.degree.
angular position, in which laundry is lying in a lower position in
said laundry drum, and through an angular position at which the
laundry is in a raised position and at which a center of gravity of
the laundry is at a lateral distance from a vertical plane
extending through said axis of rotation; an electric motor directly
connected to said laundry drum for driving said laundry drum; a
controller connected to said electric motor, said controller
configured to determine a loading weight of said laundry drum when
said laundry drum is driven from said 0.degree. angular position to
said angular position by measuring an electric driving current of
said electric motor at said angular position to produce a measured
value corresponding to the loading weight of the laundry.
20. The appliance according to claim 19, wherein the appliance one
of a washing machine and a washer/dryer.
21. The appliance according to claim 19, wherein the controller is
one of an electronic control device and an electric regulating
device.
22. A washing appliance, comprising: a stationary component; a
laundry drum rotatably mounted on said stationary component about a
horizontal axis of rotation, said drum moving through a 0.degree.
angular position, in which laundry is lying in a lower position in
said laundry drum, and through an angular position at which the
laundry is raised and at which a center of gravity of the laundry
is at a lateral distance from a vertical plane extending through
said axis of rotation; an electric motor directly connected to said
laundry drum for driving said laundry drum; and a controller
connected to said electric motor for detecting a power consumption
of said electric motor, said controller having a stored
predetermined, defined maximum current value, said controller
configured to determine a loading weight of said laundry drum when
said laundry drum is driven from said 0.degree. angular position
stored in said controller until said controller detects during
rotation of said laundry drum that a power consumption of said
electric motor corresponds to said stored maximum current value,
and to measure an angular distance traveled from said 0.degree.
angular position for producing a measured value corresponding the
loading weight of the laundry.
23. The appliance according to claim 22, wherein the appliance one
of a washing machine and a washer/dryer.
24. The appliance according to claim 22, wherein the controller is
one of an electronic control device and an electric regulating
device.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of copending
International Application No. PCT/EP99/04983, filed Jul. 14, 1999,
which designated the United States.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention lies in the field of household appliances. The
invention relates to a method for determining the loading weight of
a laundry drum in a washing machine or in a washer dryer, the drum
being driven directly by an electric motor controlled by an
electronic control or regulating device, and to an electric machine
in the form of a washing machine or a washer dryer for carrying out
a method according to the invention.
[0004] The prior art includes a washing machine with a laundry drum
that is driven about a horizontal axis of rotation by an electric
motor and that has a closable loading aperture disposed on its
periphery. The laundry drum can be loaded with laundry when it
stops in a rotational position at which the loading aperture is at
the top. An electronic control or regulating device for controlling
the electric motor that drives the drum is configured such that it
always stops the drum in the rotational position at which its
loading aperture is at the top.
[0005] German Published, Non-prosecuted Patent Application DE 44 31
846 A1 discloses a method for controlling and/or regulating a
washing machine or a washer dryer. The method is used for a laundry
drum when the drum is rotating at a speed at which the laundry
comes to rest in a manner distributed around the inner
circumference. The method is also used to calculate the unbalance
of laundry distributed in a non-uniform manner around its
circumference of the drum. Further, the method is used to calculate
the total weight of the laundry (loading) contained in the laundry
drum and to control or regulate as a function of these two values
the speed of a motor that drives the laundry drum. The method is
carried out with the laundry drum loaded (filled with laundry) when
the drum is rotating at least at a "spreading speed". The
"spreading speed" is the speed of the laundry drum at which the
laundry distributes itself around the inner circumference of the
drum. While the laundry drum is starting up, high unbalance torques
can occur because they are not taken into account. The method
furthermore requires a complicated and expensive electronic device
for detecting angular accelerations of the laundry drum.
[0006] German Published, Non-prosecuted Patent Application DE 195
46 185 A1, corresponding to U.S. Pat. No. 5,809,809, discloses a
washing machine having a laundry drum that is driven directly by an
electric motor rather than through a drive belt. As such, a rotor
of an electric motor is connected firmly in terms of rotation to a
drive shaft of the laundry drum, and the stator of the electric
motor is secured non-rotatably on the rear wall of the laundry drum
housing (washing-liquid container). Precise synchronism between the
motor and the laundry drum is thereby achieved.
SUMMARY OF THE INVENTION
[0007] It is accordingly an object of the invention to provide a
method for determining the loading weight of a laundry drum and a
laundry-processing machine for carrying out the method that
overcomes the hereinafore-mentioned disadvantages of the
heretofore-known methods and devices of this general type and that
precisely determines the loading of the laundry drum (the weight of
the laundry contained in the laundry drum) in a simple and
economical manner, even when the machine is not rotating at the
operating speed, and that can be used for any desired purpose, in
particular, for indicating the loading weight and/or for
controlling or regulating the speed and/or acceleration of the
laundry drum and/or the duration of processing of the batch of
laundry in the laundry drum.
[0008] With the foregoing and other objects in view, there is
provided, in accordance with the invention, a method for
determining a loading weight of a horizontally mounted laundry
drum, including the steps of providing a laundry drum driven by an
electric motor controlled by a controller, the laundry drum having
an axis of rotation, directly driving the laundry drum with the
electric motor, turning the laundry drum with the electric motor
from a 0.degree. angular position, in which laundry is lying in a
lower position in the laundry drum, through a rotational angle
until reaching an angular position at which the laundry is in a
raised position and at which a center of gravity of the laundry is
at a lateral distance from a vertical plane extending through the
axis of rotation, detecting the reaching of the angular position
with the controller, and producing a measured value corresponding
to a loading weight of the laundry from a driving current of the
electric motor measured when the angular position is reached.
[0009] With the objects of the invention in view, there is also
provided a method for determining a loading weight of a
horizontally mounted laundry drum, including the steps of providing
a laundry drum driven by an electric motor controlled by a
controller, the laundry drum having an axis of rotation, directly
driving the laundry drum with the electric motor, storing a
predetermined, defined maximum current value in the controller,
measuring a power consumption of the electric motor, rotating the
laundry drum with the electric motor out of a 0.degree. angular
position, in which laundry lies in a lower position in the laundry
drum, until the controller detects, during the rotation of the
laundry drum, a power consumption of the electric motor
corresponding to the stored maximum current value, the rotation
resulting in a raising of the laundry into a position in which a
center of gravity of the laundry is at a lateral distance from a
vertical plane extending through the axis of rotation, and the
rotation resulting in an angular traveling of the laundry drum to
an angular distance from the 0.degree. angular position, and
producing a measured value corresponding to a loading weight of the
laundry from a signal corresponding to the angular distance.
[0010] In accordance with another mode of the invention, the
electric motor recives and transmits at least one of power
consumption signals and control signals, and further includes the
steps of producing the control signals with the controller
dependent on angular positions of a rotor of the electric motor
relative to a stator of the electric motor, and defining or
calculating with the controller an angular distance through which
the laundry drum is turned from the 0.degree. angular position to
reach the angular position at which the loading weight of the
laundry is determined by the controller using fluctuations in at
least one of the power consumption signals and control signals.
[0011] In accordance with a further mode of the invention, the
laundry drum is part of a washing machine or a washer/dryer.
[0012] In accordance with an added mode of the invention, the
controller is an electronic control or regulating device.
[0013] In accordance with an additional mode of the invention, the
electric motor is an electronically commutated d.c. motor, and
further includes the step of defining or calculating the angular
distance or position using a number of commutation steps from the
0.degree. angular position of the laundry drum to the angular
position at which the loading weight is determined.
[0014] In accordance with yet another mode of the invention, the
electric motor is an electronically controlled reluctance
motor.
[0015] In accordance with yet a further mode of the invention,
there are also provided the steps of detecting an angular position
of the laundry drum with a tachogenerator as a function of angular
movements of the laundry drum to produce electric pulses, and
measuring angular distance traveled with a number of the electric
pulses.
[0016] With the objects of the invention in view, there is also
provided a washing appliance, including a stationary component, a
laundry drum rotatably mounted on the stationary component about a
horizontal axis of rotation, the drum moving through a 0.degree.
angular position, in which laundry is lying in a lower position in
the laundry drum, and through an angular position at which the
laundry is in a raised position and at which a center of gravity of
the laundry is at a lateral distance from a vertical plane
extending through the axis of rotation, an electric motor directly
connected to the laundry drum for driving the laundry drum, a
controller connected to the electric motor, the controller
configured to determine a loading weight of the laundry drum when
the laundry drum is turned with the electric motor from the
0.degree. angular position to the angular position by measuring an
electric driving current of the electric motor at the angular
position to produce a measured value corresponding to the loading
weight of the laundry.
[0017] With the objects of the invention in view, there is also
provided a washing appliance, including a stationary component, a
laundry drum rotatably mounted on the stationary component about a
horizontal axis of rotation, the drum moving through a 0.degree.
angular position, in which laundry is lying in a lower position in
the laundry drum, and through an angular position at which the
laundry is raised and at which a center of gravity of the laundry
is at a lateral distance from a vertical plane extending through
the axis of rotation, an electric motor directly connected to the
laundry drum for driving the laundry drum, and a controller
connected to the electric motor for detecting a power consumption
of the electric motor and having a stored predetermined, defined
maximum current value, the controller configured to determine a
loading weight of the laundry drum when the laundry drum is driven
from the 0.degree. angular position stored in the controller until
the controller detects during rotation of the laundry drum that a
power consumption of the electric motor corresponds to the stored
maximum current value, and to measure an angular distance traveled
from the 0.degree. angular position for producing a measured value
corresponding the loading weight of the laundry.
[0018] In accordance with yet an added feature of the invention,
the appliance one a washing machine or a washer/dryer.
[0019] In accordance with a concomitant feature of the invention,
the controller is an electronic control or regulating device.
[0020] The invention achieves its objectives by implementing
measurement of loading in a simple and economical manner on a
laundry-processing machine. The results of the measurement are
accurate enough to be used as parameters in control or regulation
of the laundry-processing machine. A laundry-processing machine
equipped in accordance with the invention avoids the dry movement
of the laundry in the laundry drum, which is required by prior art
methods and involves considerable wear on the laundry due to severe
friction between the fibers resting upon one another.
[0021] Other features that are considered as characteristic for the
invention are set forth in the appended claims.
[0022] Although the invention is illustrated and described herein
as embodied in a method for determining the loading weight of a
laundry drum and a laundry-processing machine for carrying out the
method, it is, nevertheless, not intended to be limited to the
details shown because various modifications and structural changes
may be made therein without departing from the spirit of the
invention and within the scope and range of equivalents of the
claims.
[0023] The construction and method of operation of the invention,
however, together with additional objects and advantages thereof,
will be best understood from the following description of specific
embodiments when read in connection with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a diagrammatic, axial cross-sectional view of a
machine with an electronic control or regulating device according
to the invention;
[0025] FIG. 2 is a diagrammatic, cross-sectional view through the
laundry drum of FIG. 1 with laundry lying at a lowest point
according to the invention; and
[0026] FIG. 3 is another diagrammatic, cross-sectional view through
the laundry drum of FIG. 1 with laundry lying at a lowest point
according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] In all the figures of the drawing, sub-features and integral
parts that correspond to one another bear the same reference symbol
in each case.
[0028] Referring now to the figures of the drawings in detail and
first, particularly to FIG. 1 thereof, there is shown an electric
machine in the form of a washing machine or a washer dryer. The
machine includes a laundry drum 2 that is rotatably mounted at the
rear in a washing-liquid container 4 by bearings 6 and can be
loaded with laundry 12 at the front through a door 8 provided in
the washing-liquid container 4 and a loading aperture formed in the
front side 10.
[0029] A rotor 14 of an electric motor 16 is connected directly and
firmly in terms of rotation to a drive shaft 18 of the laundry drum
2 such that no differences in rotational position can occur between
the rotor 14 and the drive shaft 18. A stator 20 of the electric
motor 16 is secured non-rotatably on the rear side of a rear wall
22 of the washing-liquid container 4. An electronic control or
regulating device 24 supplies and controls or regulates the
electric motor 16 through lines 28.
[0030] According to preferred embodiments of the invention, the
electric motor 16 is an electronically commutated d.c. motor, an
electrically switched reluctance motor, or an electric motor. The
control or regulating device 24 can determine the angular positions
of the rotor 14 and, therefore, also of the laundry drum 2 by
commutation steps or control pulses, which it must supply to the
electric motor 16 to supply the motor 16 with power, or which
exhibits fluctuations in power consumption as a function of its
rotational position, as in the case of a reluctance motor, which
can be detected by the control or regulating device 24.
[0031] For motors of the type mentioned above, it is not necessary
to use additional sensors, e.g., a tachogenerator 26, to determine
the rotational positions and angular distances by which the laundry
drum 2 rotates. It is, of course, also possible to use a
tachogenerator 26. With other types of electric motors 16, an
additional sensor, preferably a tachogenerator 26 that supplies
appropriate signals to the control or regulating device 24, is
required to detect the respective angular position of and angular
distance traveled by the laundry drum from an initial angular
position to an angular end position. Power-supply and electric
signal lines 28 connect the control or regulating device 24 to the
electric motor 16. Power-supply and/or electric signal lines 29
connect the control or regulating device 24 to the additional
device, e.g., the tachogenerator 26, where present.
[0032] The invention is described below without a tachogenerator
26, using examples in which the control or regulating device 24
contains a position detection device for detecting angular
positions and angular distances of the rotor 14, which is connected
directly to the laundry drum 2 in terms of drive. The electric
motor 16 is an electronically commutated d.c. motor, an
electronically switched reluctance motor, or a similar motor.
[0033] The principles on which the motors are based permit a
relatively high-resolution, i.e., very accurate, position detection
device in the control or regulating device 24 for determining the
angular position of the rotor and angular velocity of the rotor.
With the aid of such a position detection device, the angular
position of and angular distance turned by the laundry drum 2 can
be determined relatively accurately at any time. In contrast to an
indirect drive (V-belt between the electric motor and the drive
shaft of the laundry drum), no additional synchronization devices
are required. Using the invention, determination of the rotational
angle of the laundry drum 2 (rotor 14 of the electric motor 16) is
combined with measurement of the power consumption of the electric
motor 16.
FIRST EXAMPLE
[0034] FIG. 2 shows a cross-section of the laundry drum 2 in a
0.degree. angular position, in which all the laundry 12 loaded into
the drum 2 is at the bottom. Here, the center of gravity of the
laundry 12 is perpendicularly below the drum's axis of rotation 30.
When the laundry drum 2 is turned by the electric motor 16 from the
0.degree. angular position through a defined, predetermined angular
distance 32 to an x.degree. angular position, the distance 32 is
stored in the control or regulating device 24. As such, the laundry
12 has been raised into a raised position just before the point at
which it will fall. The power consumption of the electric motor 16
is measured in the x.degree. angular position by the control or
regulating device 24. The motor current is proportional to the
torque in the x.degree. angular position and, therefore, is a
measure of or value for the weight of the laundry 12 (loading of
the laundry drum 2).
[0035] Paddles 34 can be provided conventionally in the laundry
drum 2 to take the laundry 12 along in rotation.
SECOND EXAMPLE
[0036] With respect to FIG. 3, a defined, predetermined maximum
current value is stored in the electronic control or regulating
device 24. The control or regulating device 24 measures the angular
distance "X", by which the laundry drum 2 must be turned from the
0.degree. angular position before the power consumption of the
motor 16 reaches the stored current value. Therefore, the angular
distance "X" traveled is a measure of the loading or weight of the
laundry 12 in the laundry drum 2.
[0037] In both of these examples, all the laundry 12 is in the
lower part of the laundry drum 2 in the 0.degree. angular position.
By turning the laundry drum 2, the laundry 12 is moved into a
raised position, in which the laundry 12 is offset laterally
relative to the drum's axis of rotation 30. The laterally offset
position is defined by the x.degree. angular position in the first
example illustrated in FIG. 2 and by the angular distance "X" in
the second example illustrated in FIG. 3.
* * * * *