CN110656468B - Washing machine with unbalance compensation ring - Google Patents
Washing machine with unbalance compensation ring Download PDFInfo
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- CN110656468B CN110656468B CN201910553084.4A CN201910553084A CN110656468B CN 110656468 B CN110656468 B CN 110656468B CN 201910553084 A CN201910553084 A CN 201910553084A CN 110656468 B CN110656468 B CN 110656468B
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- 238000005406 washing Methods 0.000 title claims abstract description 180
- 239000012530 fluid Substances 0.000 claims abstract description 66
- 238000001035 drying Methods 0.000 claims abstract description 11
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- 239000007788 liquid Substances 0.000 claims description 22
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- 238000012544 monitoring process Methods 0.000 claims description 6
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
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- 239000003513 alkali Substances 0.000 description 1
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- 239000011888 foil Substances 0.000 description 1
- 239000011796 hollow space material Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
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Classifications
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- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
- D06F37/00—Details specific to washing machines covered by groups D06F21/00 - D06F25/00
- D06F37/20—Mountings, e.g. resilient mountings, for the rotary receptacle, motor, tub or casing; Preventing or damping vibrations
- D06F37/22—Mountings, e.g. resilient mountings, for the rotary receptacle, motor, tub or casing; Preventing or damping vibrations in machines with a receptacle rotating or oscillating about a horizontal axis
- D06F37/225—Damping vibrations by displacing, supplying or ejecting a material, e.g. liquid, into or from counterbalancing pockets
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- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
- D06F33/00—Control of operations performed in washing machines or washer-dryers
- D06F33/30—Control of washing machines characterised by the purpose or target of the control
- D06F33/48—Preventing or reducing imbalance or noise
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- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
- D06F2103/00—Parameters monitored or detected for the control of domestic laundry washing machines, washer-dryers or laundry dryers
- D06F2103/26—Imbalance; Noise level
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- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
- D06F34/00—Details of control systems for washing machines, washer-dryers or laundry dryers
- D06F34/14—Arrangements for detecting or measuring specific parameters
- D06F34/16—Imbalance
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- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Main Body Construction Of Washing Machines And Laundry Dryers (AREA)
- Control Of Washing Machine And Dryer (AREA)
Abstract
The invention relates to a washing machine having a rotatable washing drum and an imbalance compensation ring which is arranged concentrically to the washing drum and can be rotated together with the washing drum, wherein an annular cavity of the imbalance compensation ring is at least partially filled with magnetorheological fluid, the cavity is wound with at least one balancing coil for generating a magnetic field in the cavity, and the washing machine has a stationary magnetic field generating device which is provided and arranged for inducing a coil current in the balancing coil. A method for operating a washing machine, wherein the magnitude of an imbalance of a washing drum is monitored during the accelerated rotation of the washing drum in a subcritical speed range during spin-drying, by means of an imbalance detection device, and when the magnitude of the imbalance reaches or falls below a predetermined threshold value, a magnetorheological fluid is solidified by activating a magnetic field generating device. The present invention can be applied to, for example, a household washing machine.
Description
Technical Field
The invention relates to a washing machine having a rotatable washing drum and an imbalance compensation ring which is arranged concentrically to the washing drum and can rotate together with the washing drum, wherein an annular cavity of the imbalance compensation ring is at least partially filled with a magnetorheological fluid. The invention also relates to a method for operating a washing machine. The invention can be applied particularly advantageously to domestic washing machines, in particular independent washing machines or washing dryers.
Background
EP 1,154,064 A2 discloses a device for limiting the unbalance of a washing unit of a washing machine, which washing unit has a washing drum rotatably supported in a lye container and is suspended in a machine housing in order to effect vibrations by means of springs, inertia, vibration dampers and drive motors, wherein a plurality of sensors distributed over the circumference of the lye container detect bending due to the unbalance during a spin cycle and corresponding countermeasures are taken for limiting the paths and forces occurring. The washing unit is protected from overload, independently of the load in the washing drum, due to the unbalance during the spin cycle, as follows: the sensor is perpendicular and/or parallel to the axis of rotation of the washing drum and detects not only the displacement but also the phase shift between said displacements. The control and/or regulation parameters are fed to the spin cycle as a function of the determined displacement and phase shift and the speed of the washing drum and the drive motor.
EP 1,167,609 A1 discloses a washing machine with an acceleration measuring device or an optical device, which is oriented in a direction that is sensitive to the action of a load that is not dynamically compensated. The direction is preferably a direction parallel to the rotation axis of the drum. Different methods of identifying laundry imbalance are also disclosed.
DE 10 2016 220 112 A1 discloses a household appliance for caring for laundry, comprising a washing drum for receiving the laundry, and at least one imbalance compensation device having a housing in which a plurality of compensation elements are movably contained, wherein the imbalance compensation device has a magnetic field generating device by means of which, viewed in a rotational direction about a rotational axis of the washing drum, a magnetic field acting on the compensation elements can be dynamically generated variably at specific azimuthal locations, wherein, when the rotational speed of the washing drum is less than or equal to a reference rotational speed of the washing drum, a magnetic field acting on the compensation elements is generated by the magnetic field generating device in a region of azimuthal angles about the rotational axis, wherein a change in the azimuthal angle of the region is coupled to the rotational speed of the washing drum.
DE 10 2014108 856b3 discloses a washing machine having a lye container for receiving a washing liquid, a drum rotatably supported in the lye container for receiving a washing product, and a compensating device having a plurality of spherical weights which are arranged in a tube mounted concentrically to the drum, in which tube the liquid is in which the spherical weights can move relative to an equilibrium position as a reaction to an imbalance of the drum during rotation of the drum, the washing machine having means for applying an electric and/or magnetic field to the liquid in the channel, wherein the liquid is an electrorheological and/or magnetorheological liquid which increases the viscosity of the electrorheological and/or magnetorheological liquid upon addition of the electric and/or magnetic field in order to position at least a part of the weight in a positionally fixed manner.
Disclosure of Invention
The object of the present invention is to at least partially overcome the disadvantages of the prior art and in particular to provide a particularly simple and cost-effective possibility of compensating for laundry unbalance during the rotation of the washing drum of a washing machine.
This object is achieved according to the features of the invention. Advantageous embodiments are the content of the description and of the figures.
This object is achieved by a washing machine having a rotatable washing drum and a ring (hereinafter referred to without limitation to generality as an "unbalance compensation ring" or "balancing ring") which is arranged concentrically to the washing drum and rotatable therewith, wherein an annular cavity of the compensation ring is at least partially filled with magnetorheological fluid, the cavity is wound with at least one coil for generating a magnetic field in the cavity (hereinafter referred to without limitation to generality as a "balancing coil"), and the washing machine has a stationary magnetic field generating device which is provided and arranged for generating an induction current ("coil current") by means of induction in the balancing coil.
The washing machine has the advantage that the hollow space is wound by the at least one balancing coil, which provides the possibility of compensating for the unbalance caused by the laundry in the rotating drum, which is particularly simple in construction and robust and thus durable. The advantage is furthermore achieved that, on account of the winding of the unbalance compensation ring, a highly uniform magnetic field for changing the viscosity of the magnetorheological fluid in the cavity can be generated, in particular over the circumference of the unbalance compensation ring or the entire length of the cavity.
Further advantages include shortening the spin-start time until the nominal rotational speed is reached, reducing the noise during spin-drying, reducing the mechanical load of the vibration system supporting the washing drum, reducing the required vibration amplitude and then increasing the drum volume of the washing drum. A further advantage is achieved with respect to the imbalance compensation loop filled with water, since the density of the magnetorheological fluid is at most four times greater than that of water, a significantly higher imbalance compensation capacity can be achieved in the same installation space.
The washing machine may be a stand alone washing machine or a washer dryer. Washing machines, in particular domestic washing machines. The washing machine is in particular arranged for performing at least one spin-drying process. In a still further development, the washing drum is rotatably arranged in the lye container.
The unbalance compensation ring is arranged concentrically with the washing drum, in particular comprises that the rotation axis of the unbalance compensation ring corresponds to the rotation axis of the washing drum. The unbalance compensation ring may be fixed on the washing drum or may be fixed on the shaft driving the washing drum. The unbalance compensation ring can rotate with the washing drum, in particular comprises that the unbalance compensation ring can rotate at the same rotational speed as the washing drum.
The rotatable washing drum is for receiving laundry to be washed. The washing drum in particular has a horizontal or at least approximately horizontal axis of rotation, and the washing machine with the washing drum can be configured as a front-end loader.
The annular cavity is in particular a closed, through cavity. The cavity may have the same shape and/or cross-sectional size throughout its perimeter. The cavity has a cross-sectional shape, in particular circular or rectangular. Ribs, vanes, etc. are disposed in the cavity to effect entrainment of the magnetorheological fluid upon rotation of the imbalance compensation ring.
Filling the cavity at least partially with the magnetorheological fluid includes filling the cavity completely or only partially with the magnetorheological fluid. When partially filled, the remaining volume of the cavity may be present as a gas volume and/or filled by a weight, also as constructed in further detail below.
The induction of the coil current in the balancing coil can be achieved, for example, by generating a static magnetic field, in particular spatially inhomogeneous, in the section of the balancing coil by means of a magnetic field generating device. When the balance coil rotates, then the balance coil rotates also in the magnetic field, thereby generating a coil current. Alternatively or additionally, the magnetic field generated by the magnetic field generating means is a magnetic alternating field.
The magnetic field in the cavity is generated by at least one balancing coil by inducing a coil current in the balancing coil, which magnetic field causes a change in the viscosity of the magnetorheological fluid. The viscosity of magnetorheological fluids increases, in particular, with increasing strength of the magnetic field. The viscosity may be increased so much that the magnetorheological fluid becomes solid for the practical purposes of the present invention. For generating the coil current, the magnetic field generating means are provided for generating an excitation magnetic field which induces the coil current in the balancing coil. The magnetic field generating means can be activated automatically by the washing machine. Typically the magnetic field generating means may be operated such that the viscosity can be adjusted or varied. The unbalance compensation ring is composed in particular of a material, for example plastic, which is permeable to the magnetic field energy.
In one embodiment, at least one solid ("weight") movable in the cavity, in particular a plurality of at least one, is additionally arranged in the cavity. The at least one weight body, which typically has a specific weight greater than the magnetorheological fluid, advantageously serves to more efficiently compensate for laundry unbalance or imbalance than in the case of filling the unbalance compensation ring with magnetorheological fluid alone. Furthermore, the costs are significantly lower than in the case of filling the unbalance correction ring with magnetorheological liquid alone, since the amount of relatively expensive magnetorheological liquid can be significantly reduced. The viscosity range of the magnetorheological fluid can also be selected significantly variably because the magnetorheological fluid need not be oriented at a defined location. The viscosity is thus chosen to be very high, since the magnetorheological fluid can be used only as a lubricant without energizing the coil. At least one weight can be in the form of a ball or a roller. The at least one weight body is movable in the cavity, in particular comprises, that the at least one weight body is movable along the cavity. In other words, the cavity serves as a guide rail for the at least one weight body.
In a further embodiment, the cavity is filled with magnetorheological fluid only, i.e. no additional moving weight is arranged in the cavity. This has the advantage that the operation of the washing machine can be made lower in sound, since no weight is involved, for example due to a ball collision, which produces a noise emission.
In one embodiment, the balancing coil is a short-circuit coil. This achieves in a structurally particularly simple manner that the cavity passes uniformly through the magnetic field generated by the balancing coil. The short-circuit coils may in particular be designed or function like a short-circuit rotor of an induction motor or an asynchronous motor.
The stationary arrangement of the magnetic field generating means comprises that the magnetic field generating means does not rotate with the washing drum. The magnetic field generating means may for example be arranged on the lye container.
In one embodiment, the magnetic field generating device has at least one electrically excited coil. This has the advantage that a particularly strong, if necessary also variable, induction current is induced in the balancing coils. The magnetic field generating device may have at least one power source for energizing the electrically excited coil. The power supply may be arranged to generate a direct current and/or an alternating current through the exciting coil.
In one embodiment, the magnetic field generating device additionally has at least one permanent magnet, and the at least one electrically excited coil can be energized in order to be able to compensate the magnetic field generated by the at least one permanent magnet at the balancing coil. This achieves the advantage that, also in the event of a failure of the electrically excited coil, an electric current is induced by the rotation of the unbalance compensation ring in the constant magnetic field of the permanent magnet, which increases the viscosity of the magnetorheological fluid. In turn, the magnetorheological fluid can remain solidified, for example, during the braking process of the washing drum, which, for example, enables the imbalance compensation ring to be reliably braked over all relevant rotational speed ranges. By being able to compensate the magnetic field generated in the cavity by the at least one permanent magnet, no magnetic field is generated by the magnetic field generating means at the location of the balancing coil and thus the magnetorheological fluid can optionally also be kept in a liquid state. In other words, the magnetic fields of the permanent magnets are compensated by the magnetic field generated by the electrically excited coils, in particular the two magnetic fields act in a manner that at least offset one another in the position of the unbalance compensation ring or the balancing coil. The "deactivated" magnetic field generating device with respect to the magnetorheological fluid may then correspond to a state of the magnetic field generating device in which the magnetic field of the permanent magnet is compensated by the magnetic field generated by the electrically excited coil.
A further solution that facilitates efficient compensation of the magnetic fields of the permanent magnet and the field coil is that the field coil surrounds the permanent magnet.
In one embodiment, the balancing coil is arranged outside the unbalance compensation ring or is embedded in the unbalance compensation ring. The balancing coil or its conductor tracks are present as wires or as foil strips.
In one embodiment, the cavity has a free gas volume, i.e. is not completely filled. The advantage achieved thereby is that the magnetorheological fluid can be used particularly efficiently to compensate for imbalances. In addition, relatively expensive magnetorheological fluids can be saved. The gas of the free gas volume may be air or a shielding gas.
In one embodiment, the cavity has a free gas volume if additionally at least one weight is arranged in the cavity in a movable manner. This achieves a particularly inexpensive structure. The volume of the magnetorheological fluid is simultaneously selected such that the magnetorheological fluid can reliably fix the weight at least in the subcritical speed range, in the resonance speed range and, if appropriate, in the supercritical speed range.
In one embodiment, the cavity is completely filled if, in addition, at least one weight is arranged in the cavity in a movable manner. The imbalance compensation effect is then achieved primarily by the uneven location of the at least one weight in the cavity. The advantage achieved by completely filling the cavity is that the at least one weight body is reliably and positionally held in the magnetorheological fluid in a particularly accurate manner at any time during the solidification of the magnetorheological fluid.
In one embodiment, the washing machine has an imbalance detection device. This achieves the advantage that it can be precisely determined when the magnetorheological fluid compensates for the laundry imbalance particularly effectively and then when the magnetorheological fluid can be solidified and thus can be fixed in the cavity. The magnitude of the offset of the washing drum, i.e. its excitation and/or phase with respect to the rotational frequency of the washing drum, can be determined in particular by means of the unbalance detection device. Unbalance detection devices for washing drums are known in principle and are described, for example, in EP 1 154 064 A2 and EP 1 167 609 A1.
This object is also achieved by a method for operating a washing machine as described above. The method may be similar to a washing machine design and vice versa, with the same advantages.
One design scheme is:
the washing machine has an unbalance recognition device,
monitoring the magnitude of the unbalance of the washing drum during the accelerated rotation of the washing drum in the subcritical speed range during the spin-drying process by means of the unbalance detection device, and
then, when the magnitude of the imbalance reaches or falls below a predetermined threshold value, the magnetorheological fluid is solidified by activating the magnetic field generating device.
This practical solution has the advantage that the magnetorheological fluid can be fixed independently of the rotational speed in a position in which it is advantageous for reducing the unbalance of the laundry, so that a low unbalance of the washing drum can also be maintained in the subsequent resonance rotational speed range. The magnitude of the unbalance of the washing drum is understood to be the unbalance position relative to the reference point of the washing drum in addition to the amplitude of the signal proportional to the unbalance.
The accelerated rotation of the washing drum increases during the spin-drying process, in particular with respect to the rotational speed of the washing drum from rest until the target rotational speed is reached.
In a further embodiment, the threshold value may be a fixedly predefined threshold value.
In a still further aspect, the threshold may be a threshold derived from monitoring the magnitude of the imbalance. This achieves the advantage that the threshold value can be adapted to the load of laundry and the unbalance of laundry currently present in the washing drum. If, for example, the magnitude of the unbalance is determined when the unbalance is detected, the unbalance fluctuates for a determined rotational position of the washing drum over a plurality of rotational cycles, the threshold value can be set at the minimum value measured so far for this rotational position or at a value range comprising a predefined value for the local minimum value of this rotational position. That is, the threshold may also be determined dynamically. In order to dynamically determine the threshold value, in particular, a monitoring time window can be provided, within which the imbalance is analyzed and the threshold value is determined from the analysis result. The rotational speed can in particular be kept constant over a monitoring time window. The monitoring time window may cover a predefined value of the rotation circumference of the washing drum.
When the magnitude of the imbalance reaches or falls below a predetermined, optionally rotational position-dependent threshold value, the magnetorheological fluid is solidified by activating the magnetic field generating device, which may include activating the magnetic field generating device over time or at a "correction angle" or the like, for example, in order to be able to take into account delay effects, for example, evaluation durations, durations of the magnetic field for forming the balancing coil, durations for solidifying the magnetorheological fluid, etc.
When the magnetic field generating device has an excitation coil, then "activating" the magnetic field generating device corresponds to energizing or switching on the excitation coil by means of a suitable excitation current. "deactivated" may approximately comprise the disconnection of at least one excitation coil. If the magnetic field generating device additionally has at least one permanent magnet, then the "activation" of the magnetic field generating device is understood to mean that the at least one excitation coil is energized by the excitation current in such a way that the magnetic field generated by the at least one permanent magnet and by the at least one excitation coil at the location of the balancing coil is sufficient for increasing the viscosity of the magnetorheological fluid, in particular for solidifying the magnetorheological fluid, by induction of the coil current. By "deactivated" magnetic field generating means is understood approximately that the at least one excitation coil is energized by an excitation current in such a way that the magnetic field of the at least one permanent magnet generated by the at least one permanent magnet at the location of the balancing coil is practically counteracted.
In this embodiment, it is fully utilized that the spin-drying process can be theoretically divided into four rotational speed ranges. This is explained in detail below with reference to the acceleration of the rotation of the washing drum from rest. However, the present invention may be used independently of the following description.
In the first "low rotational speed range" of the spin-drying process, the washing drum is operated from rest at an increased rotational speed. The rotational speed is also so low that the laundry located in the washing drum falls back from the height determined in the washing drum. The liquid in the unbalance compensation ring remains at least in the lower region adjacent to the unbalance compensation ring or the corresponding cavity due to the effect of gravity.
With further increasing drum speeds, a "subcritical speed range" is engaged in the low speed range, in which the speed is so high that centrifugal forces acting on the laundry press the laundry onto the drum and remain there in a fixed position. The rotational speed or rotational frequency at which the laundry is at least largely applied to the washing drum may also be referred to as a "set rotational speed". The set rotational speed is, for example, related to the diameter or radius of the washing drum, the type of laundry and/or the filling quantity of the washing drum.
The laundry which is usually placed against the washing drum is not distributed uniformly over the circumference of the washing drum with respect to its weight, but a center of gravity which is offset from the axis of rotation is formed by the laundry concentration and which leads to an imbalance of the washing drum (laundry imbalance). The laundry unbalance in turn causes the resiliently mounted washing drum to be deflected or to be deflected accordingly at a corresponding excitation frequency. The mechanical support of the washing drum is usually designed as a spring/damper system. The washing drum can be arranged, for example, directly or indirectly on the damper and be connected to the spring upwards against the force of gravity.
In the subcritical speed range, the excitation frequency corresponds at least approximately to the rotation frequency, however, this phase difference is a relatively small phase angle (for example in the range of 30 °).
In the subcritical speed range, the liquid is likewise held at least initially in the lower region of the compensating ring, or may already rotate together in the imbalance compensating ring, depending on the viscosity, but generally does not rotate together at the rotational speed of the drum. That is, the relative angular position of the center of gravity of the fluid with respect to the center of gravity of the laundry about the rotation axis is constantly changing in both cases. Thus, the liquid more or less effectively compensates for the laundry unbalance and even strengthens the laundry unbalance depending on the current relative angular position with respect to the centre of gravity of the laundry. The magnitude of the resulting maximum imbalance of the washing drum (which represents the superposition of the laundry imbalance and the imbalance caused by the liquid) can be changed by a plurality of rotations.
If the rotational speed of the washing drum still continues to increase, the subcritical rotational speed range transitions into a "critical rotational speed range" or a "resonant rotational speed range", in which the excitation frequency of the washing drum falls within a resonant range, which is determined by the mechanical support of the washing drum. In this stage, the phase difference between the rotation frequency and the excitation frequency is about 90 °. If the liquid in the compensating ring is still in the liquid state in the third phase, the liquid will also strengthen the offset of the washing drum or the unbalance of the washing drum at least for a certain angular position. The stiffening of the deflection is particularly disadvantageous in the resonance speed range, since the suspension load of the washing drum is particularly high due to the unbalance.
If the rotational speed also continues to increase, the resonant rotational speed range transitions into a "supercritical rotational speed range" in which the washing drum is out of its resonant range. In the supercritical rotation speed range, the phase difference between the rotation frequency and the excitation frequency is about 180 °. The magnetorheological fluid is in the region of the compensation ring, on which the angle of the center of gravity of the compensation ring about the axis of rotation differs by 180 ° relative to the angle of the center of gravity of the laundry about the axis of rotation. In the supercritical speed range, the liquid is thus particularly effective in compensating for laundry unbalance created by the laundry concentration.
The preceding phases are again carried out in reverse order when the washing drum is braked or decelerated.
The above description applies in a sense to an arrangement in which additionally at least one movable weight is arranged in the cavity, to be precise not only when the cavity has a free air volume, but also when the cavity is completely filled, in which arrangement additionally at least one movable weight is arranged in the cavity.
The use of a magnetorheological fluid and at least one balancing coil makes it possible to solidify the magnetorheological fluid in a targeted manner during the passage through the subcritical speed range, in order to reduce the build-up of unbalance by the fluid position independently of the speed or in order to compensate for the laundry unbalance in particular also in the following resonance speed range.
The time point when the magnetic field generating means is activated is particularly easy to determine when the magnetorheological fluid and/or the at least one weight body does not rotate with the unbalance compensation ring, but remains at least substantially in the lower region of the unbalance compensation ring. In this case, the laundry imbalance can be compensated particularly effectively when the center of gravity of the laundry is located at the upper apex of the washing drum. This can be determined particularly easily. This occurs in particular when switching from the low rotational speed range into the subcritical rotational speed range or into the lower part of the subcritical rotational speed range.
In one embodiment, the magnetic field generating device is deactivated when the supercritical speed range is reached. The object of the invention is to provide a method for controlling a washing machine, which allows a particularly efficient compensation of washing imbalance, in which the magnetorheological fluid and/or the at least one weight body are/is automatically moved in the supercritical rotational speed range into a position in which the magnetorheological fluid or the at least one weight body is located opposite the center of gravity of the washing machine with respect to the rotational axis. In this case, in one variant, the magnetic field generating device can be kept activated for a predetermined period of time and/or until a predetermined rotational speed, for example a target rotational speed, is reached when the supercritical rotational speed range is reached.
In one embodiment, the magnetic field generating device is activated in the supercritical rotational speed range and remains activated at least in the resonance rotational speed range when the washing drum rotates at a reduced speed from its supercritical rotational speed range (i.e. when the rotational speed of the washing drum decreases, also referred to as deceleration or braking). The advantage achieved thereby is that the magnetorheological fluid is fixed in the supercritical rotational speed range at a position at which it compensates for the laundry unbalance in a particularly efficient manner. The magnetorheological fluid is also held in the cavity at the same position during the passage of the resonance speed range, so that the laundry imbalance is compensated particularly effectively by the magnetorheological fluid also during the resonance speed range.
In a further development, the magnetic field generating device is deactivated when the rotational speed of the washing drum is in the subcritical rotational speed range or in the low rotational speed range. This achieves the advantage that electrical energy is saved for operating the magnetic field generating device for relatively low rotational speeds at which the strengthening of the imbalance by the magnetorheological fluid is small.
Drawings
The foregoing features, and advantages of the invention as well as a manner of attaining them will become more apparent and be better understood by reference to the following illustrative description of embodiments of the invention taken in conjunction with the accompanying drawings.
Fig. 1 shows a simplified diagram of a washing machine according to a first embodiment in rest as a sectional view in front view;
fig. 2 shows a schematic view of the washing machine according to the first embodiment in a supercritical rotational speed range as a cross-sectional view;
fig. 3 shows a schematic view of a washing machine according to a second embodiment in a supercritical rotation speed range as a cross-sectional view;
fig. 4 shows a schematic view of a washing machine according to a third embodiment in rest as a cross-sectional view;
fig. 5 shows a schematic view of a washing machine according to a third embodiment in a supercritical rotation speed range as a cross-sectional view.
Detailed Description
Fig. 1 shows a washing machine 1 having a rotatable washing drum 2 and an imbalance compensation ring 3 arranged concentrically to the washing drum 2 and rotatable with the washing drum 2. The annular cavity 4 of the imbalance compensation ring 3 is partially filled with magnetorheological fluid 5, i.e., also has a free (e.g., air-filled) gas volume 10. The cavity 4 is wound by at least one balancing coil 6 for generating a magnetic field in the cavity 4.
The washing machine 1 further has magnetic field generating means 7 provided and arranged for inducing a coil current in the balancing coil 6. The magnetic field generating device 7 has an exciting coil 8 and a power supply 9 connected to the exciting coil. The power supply 9 in particular generates a current I which excites the excitation coil 8 to generate a magnetic field. The magnetic field induces an induced current in the balancing coil 6 which in turn generates a magnetic field through the cavity 4. Since the balancing coil 6 is wound around the entire circumference of the unbalance correction ring 3 and is designed as a short-circuit coil, the magnetic field passes through the balancing coil virtually uniformly over the entire circumference. The balancing coil 6 may be arranged outside the unbalance compensation ring 3 or embedded in the unbalance compensation ring 3.
The magnetic field generating means 7 are arranged stationary relative to a lye container 11 in which the washing drum 2 is rotatably received.
In this figure, the washing drum 2 is not rotating, i.e. is in rest. The magnetic field generating means 7 are not activated and thus do not generate a magnetic field in the cavity 4, which magnetic field causes the magnetorheological fluid 5 to solidify. The magnetorheological fluid 5 is thus in its liquid state and remains in the lower section of the unbalance compensation ring 3 due to its weight. In rest, the laundry W located in the washing drum 2 is also at the bottom of the washing drum 2.
If the washing drum 2 starts to rotate about its rotation axis D at the beginning of the spin-drying process, the laundry W falls back to the bottom of the washing drum 2 from the upper region of the washing drum 2, although being driven by the washing drum 2. The magnetorheological fluid 5 is also held in the lower section of the imbalance compensation ring 3 with sufficient free flowing properties. The state may also be referred to as a "low rotation speed range".
As the rotational speed continues to increase, a set rotational speed is reached at which the laundry W is held on the inside of the washing drum 2 by centrifugal force. A laundry imbalance is thereby usually produced, which causes the washing drum 2 to shift. In this "subcritical speed range", the magnetorheological fluid can likewise be held at least substantially in the lower section of the unbalance compensation ring 3, or already be brought about by the rotation of the washing drum 2, depending on the viscosity, but not necessarily at the same speed as the washing drum 2. In both cases, the relative angular position of the wash thing W with respect to the magnetorheological fluid 5 may be continuously changed.
In a further version of the washing machine 1, the washing machine is equipped with unbalance recognition means 12, which are arranged, for example, in the lye container 11. The unbalance detection device 12 is connected to a control device 13 which controls the power supply 9.
The magnitude of the unbalance of the washing drum 2 is monitored by means of the unbalance detection device 12 during the accelerated rotation of the washing drum 2 in the subcritical speed range during the spin-drying process. When the magnitude of the unbalance reaches or falls below a predefined threshold value, the control device 13 can be activated in order to solidify the magnetorheological fluid 5 by activating the magnetic field generating device 7. The magnetorheological fluid 5 is fixed in the cavity 4 by solidifying the magnetorheological fluid, so that the magnetorheological fluid remains in the region of the subsequent resonance rotational speed, which is advantageous for reducing the imbalance.
The magnetic field generating means 7 are deactivated when the supercritical speed range is reached, since in the supercritical speed range the liquid is automatically arranged in the cavity 4 in such a way that the unbalance of the washing drum 2 is actually compensated for maximally, as is shown in fig. 2.
When the washing drum 2 is rotated or braked from its supercritical speed range, the magnetic field generating device 7 is activated in the supercritical speed range, so that the magnetorheological fluid 5 is also held in a position in which it compensates for the laundry unbalance in a particularly efficient manner when it leaves the supercritical speed range. The magnetic field generating means 7 are kept activated at least in the resonance speed range.
Fig. 3 shows a schematic view of a washing machine 21 according to a second embodiment in a supercritical rotational speed range as a cross-sectional view. The washing machine 21 is constructed similarly to the washing machine 1, however the magnetic field generating device 22 additionally has at least one permanent magnet 23. Furthermore, the electric excitation coil 8 can be energized by means of the control device 13, so that the magnetic field generated by the at least one permanent magnet 23 at the balancing coil 6 can be compensated.
Thereby achieving a "pre-calibration" of the viscosity of the magnetorheological fluid 5. That is, if a fault condition occurs in which the exciting coil 8 can no longer be energized, a magnetic field is induced in the balancing coil 6 by the permanent magnet 23, so that the viscosity of the magnetorheological fluid 5 is increased and the magnetorheological fluid 5 is fixedly held also in the fault condition. In this case, the excitation coil 8 is wound directly around the permanent magnet 23. Whereby the generated magnetic field can be completely eliminated.
Fig. 4 shows a schematic view of a washing machine 31 according to a third embodiment in rest as a sectional view. The washing machine 31 is constructed similarly to the washing machine 1, however, in this case there are a plurality of weights in the form of balls 32 in the cavity 4. The ball 32 is able to move in the cavity 4 so that the cavity 4 acts as a guide for the ball 32. The cavity 4 also has a large free gas volume 10.
Fig. 5 shows a schematic view of a washing machine 31 according to a third embodiment in a supercritical rotational speed range as a cross-sectional view. In the supercritical rotational speed range, the magnetorheological fluid 5 can be distributed, for example, annularly throughout the cavity 4, however, the balls 32 remain in a position opposite the laundry W in the cured state, where the balls 32 maximally compensate for the laundry unbalance. That is, the weight required to compensate for the unbalance of the laundry is mainly provided by the ball 32.
Of course the invention is not limited to the embodiments shown.
Generally, "a" is understood to mean either singular or plural, especially "at least one" or "one or more", etc., provided that this is not specifically excluded, for example, by the expression "exactly one" etc. For example, a washing machine having an imbalance compensation ring 3 arranged concentrically to the washing drum 2 and rotatable with the washing drum 2 can also be constructed with two imbalance compensation rings 3 arranged concentrically to the washing drum 2 and rotatable with the washing drum 2.
List of reference numerals
1. Washing machine
2. Washing drum
3. Unbalance compensation ring
4. Cavity cavity
5. Magnetorheological fluid
6. Balance coil
7. Magnetic field generating device
8. Exciting coil
9. Power supply
10. Free gas volume
11. Alkali liquor container
12. Unbalance recognition device
13. Control device
21. Washing machine
22. Magnetic field generating device
23. Permanent magnet
31. Washing machine
32. Ball with ball body
D axis of rotation
I current
W washes.
Claims (9)
1. A washing machine (1; 21; 31) having a rotatable washing drum (2) and an imbalance compensation ring (3) arranged concentrically to the washing drum (2) and rotatable together with the washing drum (2), wherein,
the annular cavity (4) of the unbalance compensation ring (3) is at least partially filled with a magnetorheological fluid (5),
-the cavity (4) is wound by at least one balancing coil (6) for generating a magnetic field in the cavity (4), and
the washing machine (1; 21; 31) has a stationary magnetic field generating device (7; 22) which is provided and arranged for inducing a coil current in the balancing coil (6),
the washing machine (1; 21; 31) has an imbalance detection device (12) for determining the amplitude of the offset of the washing drum (2), i.e. its excitation and/or phase with respect to the rotational frequency of the washing drum (2),
the washing machine (1; 21; 31) is configured to monitor the magnitude of an imbalance of the washing drum (2) by means of the imbalance detection device (12) during an accelerated rotation of the washing drum (2) in a subcritical speed range during spin-drying,
the washing machine (1; 21; 31) is arranged to solidify the magnetorheological liquid (5) by activating the magnetic field generating means (7; 22) when the magnitude of the unbalance reaches or falls below a predetermined threshold value,
-the washing machine (1; 21; 31) is arranged to be able to determine the point in time of activation of the magnetic field generating means when the magnetorheological liquid does not rotate with the unbalance compensation ring but remains at least substantially in the lower region of the unbalance compensation ring.
2. Washing machine (1; 21; 31) according to claim 1, wherein the balancing coil (6) is a short-circuit coil.
3. Washing machine (1; 21; 31) according to claim 2, wherein the magnetic field generating means (7; 22) have at least one electrically exciting coil (8).
4. A washing machine (21) according to claim 3, wherein the magnetic field generating means (22) additionally has at least one permanent magnet (23) and the at least one electrically exciting coil (8) can be energized so that the magnetic field generated by the at least one permanent magnet (23) at the balancing coil (6) can be compensated.
5. Washing machine (1; 21; 31) according to any one of claims 2 to 4, wherein the balancing coil (6) is arranged outside the unbalance compensation ring (3) or embedded in the unbalance compensation ring (3).
6. Washing machine (1; 21; 31) according to any one of claims 1-4, wherein the cavity (4) has a free gas volume.
7. Washing machine (1; 21; 31) according to any one of claims 1-4, wherein the cavity (4) is completely filled with the magnetorheological liquid (5).
8. Washing machine (1; 21; 31) according to any one of claims 1-4, wherein additionally at least one weight body movable in the cavity (4) is arranged in the cavity.
9. Method for operating a washing machine (1; 21; 31) according to any one of claims 1-8, wherein,
-monitoring the magnitude of the unbalance of the washing drum (2) by means of the unbalance detection device (12) during the accelerated rotation of the washing drum (2) in the subcritical speed range during spin-drying, and
then solidifying the magnetorheological fluid (5) by activating the magnetic field generating means (7; 22) when the magnitude of the unbalance reaches or falls below a predetermined threshold value,
deactivating the magnetic field generating means (7; 22) when the supercritical speed range is reached,
-the magnetic field generating means (7; 22) are activated in the supercritical speed range and remain activated at least in the resonance speed range, when the washing drum (2) is rotated at reduced speed from its supercritical speed range.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102018210562.6A DE102018210562A1 (en) | 2018-06-28 | 2018-06-28 | Washing machine with balance ring |
| DE102018210562.6 | 2018-06-28 |
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| Publication Number | Publication Date |
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| CN110656468A CN110656468A (en) | 2020-01-07 |
| CN110656468B true CN110656468B (en) | 2023-08-22 |
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| CN201910553084.4A Active CN110656468B (en) | 2018-06-28 | 2019-06-25 | Washing machine with unbalance compensation ring |
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| CN (1) | CN110656468B (en) |
| DE (1) | DE102018210562A1 (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101962901A (en) * | 2009-07-22 | 2011-02-02 | 海尔集团公司 | Gimbal device of rolling drum-type washing machine |
| CN202116870U (en) * | 2011-06-01 | 2012-01-18 | 无锡小天鹅通用电器有限公司 | Ball balancing device of washing machine |
| CN102537186A (en) * | 2012-01-31 | 2012-07-04 | 江南大学 | Magnetorheological fluid balance ring |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10022609C2 (en) | 2000-05-09 | 2003-11-13 | Whirlpool Co | Method for limiting the unbalance effect of a washing unit in a washing machine and device for carrying out the method |
| EP1167609B2 (en) | 2000-06-30 | 2007-09-12 | Whirlpool Corporation | Method for detecting and controlling the dynamic unbalance in a drum of a washing machine and washing machine that uses such method |
| KR101604708B1 (en) * | 2009-01-23 | 2016-03-18 | 엘지전자 주식회사 | Washing machine with unbalance reducing device |
| DE102014108856B3 (en) | 2014-06-25 | 2015-04-30 | Miele & Cie. Kg | Washing machine with imbalance compensation |
| DE102015104933B4 (en) * | 2015-03-31 | 2016-12-01 | Inventus Engineering Gmbh | Damper device for a drum-equipped washing machine or a tumble dryer |
| DE102016220112A1 (en) | 2015-11-12 | 2017-05-18 | BSH Hausgeräte GmbH | Household appliance for the care of laundry items with an azimuthally variable magnetic field imbalance compensation device and method for operating such a domestic appliance |
| CN106884280A (en) * | 2015-12-15 | 2017-06-23 | 青岛海尔智能技术研发有限公司 | Washing machine |
-
2018
- 2018-06-28 DE DE102018210562.6A patent/DE102018210562A1/en active Pending
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- 2019-06-25 CN CN201910553084.4A patent/CN110656468B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101962901A (en) * | 2009-07-22 | 2011-02-02 | 海尔集团公司 | Gimbal device of rolling drum-type washing machine |
| CN202116870U (en) * | 2011-06-01 | 2012-01-18 | 无锡小天鹅通用电器有限公司 | Ball balancing device of washing machine |
| CN102537186A (en) * | 2012-01-31 | 2012-07-04 | 江南大学 | Magnetorheological fluid balance ring |
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| DE102018210562A1 (en) | 2020-01-02 |
| CN110656468A (en) | 2020-01-07 |
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