EP3561170A1 - Household device for cleaning items of laundry and method for operating a household device - Google Patents

Abstract

The invention relates to a domestic appliance (1) for the care of items of laundry, comprising a washing tub (4) in which a washing drum (3) designed to receive the laundry items is arranged, and to a pumping system (7) comprising a circulating pump by means of which a fluid from a lower region (13) of the tub (4) in an upper region (14) of the tub (4) is conveyed. A control device (20) provided for activating the circulation pump is designed to determine a delivery rate of at least the circulation pump on the basis of at least one operating parameter of the circulation pump. The domestic appliance (1) comprises a flow measuring device (23), by means of which a flow of the fluid through a line (16) of the pumping system (7) can be detected, via which the fluid of the circulation pump can be supplied. The control device (20) is designed to take into account at least one measured value of the flow measuring device (23) when determining the delivery rate of the circulation pump. Furthermore, the invention relates to a method for operating such a household appliance (1).

Description

The invention relates to a domestic appliance for the care of items of laundry, with a tub, in which a laundry drum designed to receive the items of laundry is arranged, and with a pumping system, which comprises a circulation pump. By means of the circulation pump, a fluid from a lower region of the tub in an upper region of the tub can be conveyed. A control device of the domestic appliance provided for driving the circulation pump is designed to determine a delivery rate of the circulation pump on the basis of at least one operating parameter of the circulation pump. Furthermore, the invention relates to a method for operating such a household appliance.

In modern washing appliances or household appliances for the care of laundry, which allow ever larger loads of laundry, there is a challenge to realize the best possible drainage of the laundry after the washing process as well as in a program step of Spülschleuderns or Endschleudern. This challenge is becoming more and more demanding due to the increased load of such household appliances. Because of structural conditions of the vibration system of the household appliance, ie a unit which comprises the tub and the laundry drum, the drainage process has made procedurally difficult. This is primarily due to the fact that in these novel washing devices, the fluid to be pumped is no longer single-phase. Rather, the fluid is present as a two-phase foam-water mixture. This is due in particular to the tight installation space conditions and the associated, narrow gap geometries in the oscillating system and the resulting steep velocity gradients of the fluid. Thus, the requirements for the dewatering process and the implementation of the dewatering process are changing dramatically, or the requirements for the discharge process are redefined.

Due to the increased load on modern washing machines, the lint per wash cycle has increased disproportionately. This is due to the equally increased washing mechanics, ie the changed mechanical conditions during the washing process. Such increased demands on dewatering but also on the introduction of washing fluid or wash into the laundry during washing, as well as the increased fluff accumulation are observed in particular in washing machines, which have a load of more than 8 kilograms, for example, a load of one Range from 8 kg to 12 kg.

In order to be able to better adapt the washing processes to such a large or increased laundry load, modern, large-volume washing appliances are generally equipped with a pumping system which, in addition to a drainage pump, comprises a circulation pump. This circulation pump conveys the wash liquor or the fluid better and, above all, faster into the laundry. Because the circulation pump delivers fluid from a lower portion of the tub in an upper region of the tub. As a result, not only does the rotation of the laundry drum in the washing operation need to ensure the introduction of the fluid into those laundry items which are located in the upper region of the laundry drum. Rather, in particular by the operation of the circulation pump, the fluid or the wash liquor transported upwards. Also, rinsing the wash liquor from the laundry items can be done faster and more efficiently by providing the circulation pump.

In such a washing device thus usually a pumping system is used, which includes a pumping function and a Umpumpfunktion. As drives of the circulation pump, which causes the pumping, and the drain pump, which causes the pumping, separate electric motors are used. In such electric motors, it is possible to infer the physical pump states via the operating parameters of the respective electric motor. For example, for this purpose, the torque of the pump forming stream can be used.

A corresponding method for detecting the load state of a pump of a household appliance designed, for example, as a washing machine is shown in FIG WO 2009/156326 A2 described.

By detecting the strength of the electrical current with which the pump is acted upon in pumping operation, it can be detected indirectly, for example, whether the corresponding pump delivery flow adjusts at a selected rotational speed of the pump. Furthermore, it can be determined whether, despite a rotation of a drive wheel or impeller of the pump, no appreciable flow rate is established, for example because there is a blockage of the drainage flow paths.

However, it turns out to be difficult to deduce from the operating parameters of the pump precisely to the actual delivery capacity of the pump. Because corresponding characteristic curves, which can be for example for a certain speed of the pump on the flow rate of the pump depending, for example, on the current consumption of the pump close, apply to a specific density of funded by the pump fluid. However, due to the increased seizure of lint in modern household appliances for the care of laundry and due to the formation of the fluid as a two-phase foam-water mixture, there may be deviations of the actual density of the fluid from the density, which underlies the respective characteristic. This makes it difficult to correctly determine the delivery rate of the pump. This makes it more difficult to take appropriate countermeasures by driving the pump at an insufficient flow, such as when the pump has sucked air and so does not promote the desired flow.

Object of the present invention is therefore to provide a household appliance of the type mentioned, in which the flow rate of the circulation pump can be determined particularly reliable, and to provide a corresponding, particularly reliable method for operating a household appliance.

This object is achieved by a household appliance and a method according to the respective independent claims.

The household appliance according to the invention for the care of items of laundry comprises a tub in which a laundry drum designed to receive the items of laundry is arranged. A pumping system of the household appliance comprises a circulation pump, by means of which a fluid from a lower region of the tub can be conveyed into an upper region of the tub. A control device of the household appliance is used to control the circulation pump. The control device is designed to determine a delivery rate of at least the circulation pump based on at least one operating parameter of the circulation pump. The household appliance comprises a flow measuring device. By means of the flow measuring device, a flow of the fluid through a line of the pumping system can be detected, via which the fluid of the circulation pump can be supplied. The control device is designed to take into account at least one measured value of the flow measuring device when determining the delivery rate of the circulation pump. In particular, the control device is designed to close based on the at least one operating parameter to a flow of the circulation pump.

By means of the flow measuring device arranged on a suction side of the pumping system or upstream on the suction side, it is possible to obtain information about the flow velocity of the fluid which is actually supplied to the circulation pump via the line during operation of the pumping system. By the at least one measured value, which is provided by the flow measuring device of the control device, in addition to the at least one operating parameter of the circulation pump, a further parameter is provided which allows the control device to the operating state of the pumping system, in particular to the operating state of the circulation pump , and to conclude on the properties of the fluid to be pumped. These properties may in particular comprise a density of the fluid and / or fractions of a solid phase, a liquid phase and / or a gaseous phase in the fluid. The flow measuring device thus serves as a second or redundant measuring system, which enables the control device, not only taking into account the at least one operating parameter of at least one electric motor of the pumping system, but also taking into account the at least one measured value of the flow measuring device, ie via the flow measurement on to infer the operating state of the pumping system, in particular the flow rate or the flow rate of the circulation pump. The delivery rate or the delivery rate of at least the circulation pump can thus be determined particularly reliable.

This is based on the finding that in domestic appliances for the care of laundry now increasingly variable-speed electric motors are used as drives of pumps. For example, in washing machines, liquor pumps and pump systems with an additional circulation pump are used, in which variable-speed, permanently excited synchronous motors are controlled by a control device as drives. In particular, when using a variable-speed and variable in the direction of rotation electric motor as a drive of such pumps can be detected on the control-related detection of the operating parameters such as the speed and torque of the current state of the pump. For example, it is possible to detect whether the pump used pumps the complete flow or, for example, has sucked in air. Then namely the flow is torn off, and the pump has only built up a pressure column and is thus in the so-called snorkeling or sniffing operation. Furthermore, it can be detected on the detection of the operating parameters of the pump, if the pump with a constant remaining, but reduced compared to pumping a single-phase fluid power demand a two-phase fluid or a two-phase wash with a density, which compared to the single-phase, ie less or as good as no foam-containing wash liquor is reduced.

Because for these different operating conditions is also a different power requirement of the pump. This respective power requirement can be detected, for example, via the respective torque of the electric motor and thus via the torque-forming current, which is also referred to as "Iq" or abbreviated to "Iq".

By providing the flow measuring device, however, the operating state of the pumping system, in particular the delivery rate or the delivery rate of the circulation pump, can be determined particularly reliably. Because it can be verified whether the boundary conditions assumed by the control device when determining the delivery rate are correct. This applies in particular to the density of the fluid, which is based on the dependence of the delivery rate of the pump on the rotational speed of the electric motor and the delivery flow. Thus, for example, if the circulation pump promotes more dense fluid due to the presence of lint than would be the case with less lint, the power requirement of the circulation pump is greater to provide a desired flow. By virtue of the fact that the actual flow of the fluid through the line of the pumping system can be detected by means of the flow measuring device, the actual flow rate of the fluid delivered at a certain drive power of the circulation pump can be realistically detected. In fact, the actual delivery rate of the circulation pump is less than would be the case for the given speed and the instantaneous torque-forming current Iq, but of lesser density of the fluid.

The same applies analogously when the pump delivers a fluid or mixture of reduced density due to the presence of more foam in the two-phase foam-water mixture. Here, at a given rotational speed of the circulation pump and a given torque-forming current Iq, there is a greater actual flow rate than would be the case with the same drive power of the circulation pump and the same speed but with a higher density fluid. This can also be taken into account by taking into account the at least one measured value provided by the flow measuring device of the control device. Thus, the actual delivery rate of the pumping system, in particular the circulation pump and / or a drain pump of the pumping system, can be determined particularly reliably.

The improved determination of the operating state of the circulation pump and / or the drain pump of the pumping system thus applies in particular to operating conditions in which there is a two-phase fluid to be pumped, and in which therefore of the torque-forming current is no longer directly on the value pair of pressure and flow or delivery can be closed for a known speed.

Furthermore, not only improved from the operating parameters of the circulation pump, which are detectable via the control device or the pump drive control, on the operating state of the pumping system, in particular the circulation pump, closed. Rather, procedural process steps can also be initiated, for example in order to prevent the snorkeling operation or snoring operation of the circulation pump and / or the drain pump connected with annoying noises. Furthermore, it is possible, depending on the requirements, for example, at full, single-phase flow rate to promote the fluid optimized in terms of efficiency. As a result, heating of the drive of the pump, that is the electric motor of the circulation pump and / or the drain pump is minimized.

In addition, it can be ensured that in the presence of the two-phase fluid, ie in the presence of a two-phase medium or foam-water mixture, the pumping system is operated such that the circulation pump and / or the drain pump promotes at a high pressure but a slow flow rate , This ensures that the two phases of the two-phase fluid do not separate in a suction region of the pumping system. Rather, the two-phase, the reduced density fluid having continued to be promoted homogeneous and uniform at reduced flow rate or reduced flow rate. In order to achieve a flow state of the fluid, in which the flow rate is reduced and the pump promotes high pressure, can be provided in particular that a direction of rotation of a drive wheel or impeller of the pump is reversed. In this way, it can be achieved that the two-phase lye mixture or fluid can be conveyed without the two phases separating due to the low flow velocities.

The household appliance comprising the flow measuring device thus makes it possible to provide a procedural solution for drainage in which a torn-off pump delivery flow can be rebuilt after the intake of air by the pump after only a relatively short time. In the presence of a suction-side Rückstaumenge to fluid this suction-side Rückstaumenge can be reduced to fluid so very quickly again. This also applies to heavily foamed pumping, in particular umzupumpendem or to be pumped fluid. Again, it can be ensured comparatively quickly that the complete desired nominal flow rate of the pump, be it the circulation pump or the drainage pump, is rebuilt, even if the reduced-density, two-phase medium or fluid is present.

The flow rate, in particular of the pumped circulation system, can thus be controlled in an improved manner by detecting the at least one operating parameter on the one hand and by taking into account the at least one measured value of the flow measuring device on the other hand. Because the redundancy measurement method, which can be carried out by means of the flow measuring device, allows the adjustment of the flow rate or the flow rate, for example on the basis of the flow velocity detectable by the flow meter.

By the flow of the fluid at a known location, so at a point with a known constructive flow cross-section can be detected, can be deduced on the basis of the flow velocity with the aid of the flow meter on the flow of the fluid. This allows even more accurate differentiation of the operating states of the pump, be it the circulation pump, by means of which the pumping of the fluid is effected, be it the drain pump of the pumping system, by means of which the dewatering or pumping out of the fluid can be effected. By providing the flow measuring device so the home appliance is supplemented by a redundancy measuring system, which allows to determine the actual flow rate of the pumping system particularly reliable.

Furthermore, a particularly load-adequate flow of the laundry can be achieved, in particular by a flow rate of the pumping system or the circulation pump adapted in the speed. In this way, depending on the load of the laundry drum with laundry always good wash results can be achieved. So it can be achieved an improved washing performance.

In addition, blockages can be avoided or detected particularly early. This applies both to the pumping paths when pumping over the fluid or of water and / or wash liquor as well as the pumping or emptying of the tub by means of the drain pump of the pump system. In particular, a degree of clogging of a filter device can be detected improved. By means of such a filter device it is also possible to ensure that the laundry or the items of laundry are always subjected to filtered fluid or filtered wash liquor when pumping over. For a quasi lint-free washing device or household appliance for the care of laundry is provided, which is particularly low maintenance.

Furthermore, a user or an operator of the household appliance can be communicated, in particular visualized, the presence of blockages or a degree of clogging of a filter device. For the user or the operator, the provision of the flow meter means increased comfort in the use of the household appliance and a secure device operation in the laundry care.

The flow measuring device preferably comprises an impeller arranged in the line of the pump system. By detecting a rotation of the impeller can be particularly easily and reliably detected the flow velocity as the fluid flows through the conduit. Accordingly, by means of the flow meter comprising the impeller, it is also very easy to determine a volumetric flow of the fluid as it flows through the conduit.

Furthermore, by providing the flow measuring device comprising the impeller, it can be ensured that those properties of the fluid which influence the delivery rate of the pumping system are also present in the region of the impeller and are thus detected in a particularly realistic manner.

Additionally or alternatively it can be provided that the flow measuring device comprises an impeller which is arranged in a bypass line. Here, the bypass line leads from a branch point of the line of the pumping system to a mouth opening. At the mouth opening, the bypass line is connected to a chamber of a pump housing of the pumping system and / or to the line of the pumping system. By providing the bypass line can be suction side a realize parallel bypass flow, which serves to measure the flow through the line of the pumping system. This bypass flow or bypass flow is to be understood as similar to an electrical parallel circuit in which a high-resistance resistor is arranged in a parallel line branch or bypass branch in order to detect the current intensity of the electrical current flowing through the main line.

Even with a hydraulic system, the bypass line is thus preferably realized with a small flow cross section of the provided by the bypass line parallel measuring section. By providing the bypass line can be ensured that the flow resistance of the pumping system is not increased in the line of the pumping system despite the provision of the flow measuring device. This is conducive to efficient operation of the pumping system.

Preferably, a flow cross section of the bypass line is chosen so small that the flow resistance through the line of the pumping system fails significantly smaller than the flow resistance over the measuring section or via the bypass line. In particular, it can be ensured in this case that the impeller arranged in the bypass line begins to turn just as soon as a flow of fluid through the line of the pumping system takes place.

In order to keep a leakage current via the measuring line or bypass line as low as possible, a braking device can also be provided which then brakes or brakes the impeller of the flow measuring device, if no evaluation of the data or measured values detected by the flow measuring device is provided. By this braking of the arranged in the bypass impeller even higher flow resistance can be generated as needed. As a braking device, a mechanical brake can be used. Additionally or alternatively, a braking effect can be realized via a magnetic field, which can be generated by energizing a coil. The impeller then preferably has at least one magnetic portion on which the magnetic field generated by the coil can act for braking.

By detecting the flow velocity in the bypass or the bypass line can on the degree of contamination of the line of the pumping system or the main line. Thus, a suction-side blockage of the pumping system or a suction-side increase in the flow resistance in the pumping system can be detected reliably.

The rotation of the arranged in the line of the pumping impeller and / or disposed in the bypass line impeller can be reliably detected by a mechanical counter. At the same time, however, it is particularly easy to ensure the tightness of the pumping system if the rotation of the impeller is detected without contact.

Therefore, it is preferably provided that a rotation of the impeller can be detected without contact by means of a sensor of the flow measuring device arranged on an outer side of the line of the pumping system and / or on an outer side of the bypass line. For example, by the rotation of the impeller a corresponding rotation of a magnet can be effected, such as by a portion of the impeller, which rotates about an axis of the impeller, is magnetically formed. Such a magnet can induce a voltage pulse in a coil, which can be detected as a measured value of the flow measuring device. Furthermore, the sensor arranged on the outside of the line of the pumping system or on the outside of the bypass line can be designed as a Hall sensor. In this way, the non-contact detection of the rotation of the impeller can be realized particularly easily.

Additionally or alternatively, the flow measuring device can be designed as a magnetic-inductive flow meter. This is based on the finding that both the fluid flowing through the line during operation of the pumping system in the form of water and in particular in the form of wash liquor has sufficient electrical conductivity to enable the magnetic-inductive flow measurement. With the provision of the bypass line, the flow of the fluid through the bypass line can also be detected simply and reliably via the magnetic-inductive flow measurement, alternatively or additionally to the provision of the impeller in the bypass line. The magnetic-inductive flow measurement also has the advantages associated with the non-contact detection of the at least one measured value, wherein the measured value can in particular indicate the flow velocity of the fluid through the line. In the magnetic-inductive flow velocity detection is caused by the measuring principle excludes clogging or blocking the flow measuring device, as they can otherwise occur in a flow measuring device having an impeller or a measuring wheel.

Preferably, the pumping system comprises a drain pump, to which the fluid can be supplied via the line. In other words, the line is then designed as a suction line or part of a suction line of both the circulation pump and the drain pump. Preferably, the circulation pump and the drain pump are arranged in a common pump housing of the pumping system. This makes it possible to realize a large compactness of the pumping system.

It has also proven to be advantageous if a filter device is arranged in the line of the pumping system upstream of the flow measuring device and / or downstream of the flow measuring device. By arranging the filter device upstream of the flow measuring device, it is possible to avoid an impairment of the flow measurement in the event that the flow measuring device has a mechanical component that can be moved by the flow of the fluid, for example an impeller such as a worm wheel and / or an impeller. However, even with an arrangement of the filter device downstream of the flow measuring device, the filter device at least ensures that flow paths of the pump system used during the pumping circulation by means of the circulation pump do not clog. This makes it possible to avoid a functional impairment of the pumping system, in particular of the circulation pump.

The filter device can be designed in the manner of a sieve, which serves in particular for the retention of hair, fluff and the like. Additionally or alternatively, the filter device may be formed as a foreign body trap, which serves to retain larger foreign bodies such as coins, hair clips or the like small parts. If such a filter device is provided, it is also possible to conclude that the filter device has been attached by means of the flow measuring device.

If the filter device is designed as a foreign body trap, then it can be provided that, although foreign body on the suction side or through the foreign body trap However, lint can be pumped at least to a small extent by means of the pumping system, in particular the circulation pump, further pumped. It is thereby achieved that maintenance intervals are comparatively long, or that maintenance does not need to be carried out unnecessarily often and thus in a troublesome frequency for an operator or a user of the household appliance.

In the structural design of the filter device as a foreign body trap and / or as a lint filter different priorities can be set depending on specifications or requirements or aspects are taken into account. Such aspects may pump protection of the pumping system, frequency of maintenance or intervals of maintenance, foreign matter retention, a potential of the pumping system, fluff-added fluid, accessibility to the filter device, visibility of the pumping system to the user or for the operator of the household appliance and the like.

For the development of the designed as a foreign body trap or mesh filter or the like filter device so it is important to find an optimal compromise, in which preferably a number of criteria are jointly realized in the best possible way. These criteria may include foreign body retention due to the geometry of the filter device, misfire-proof mounting, accessibility, and / or visibility of that portion of the pumping system in which the filter device is disposed, a possibility to disassemble the filter device even if due to at least one Foreign body is a blockage of the filter device, a possibility of cleaning the filter device by an operation of the pumping system, and a Abspülfunktionalität for removing hair and / or lint from the filter device.

This can be taken into account if according to a further preferred embodiment of the household appliance, the filter device is arranged in an inlet-side chamber of the pump housing, from which the fluid of the drain pump can be supplied. In this case, the filter device can be realized by a Saugrohrschirmung so that both the circulation pump and the drain pump a filter grid or the like as the filter device is connected upstream. Furthermore, a labyrinth filter may be provided as a filter device for the drain pump and the circulation pump.

However, in particular with regard to the possibility of self-cleaning or rinsing off of the filter device, it has proven to be advantageous if the filter device has at least one wall area formed for retaining solids from the fluid, from which solids can be removed by operating the drainage pump. Thus, in particular by a sequential, temporally offset activating once the circulation pump and then the drain pump, a cleaning of the filter device can be effected. For by operating the drain pump following operation of the circulation pump, it is ensured that the solids retained on the at least one wall region are rinsed off the wall region again.

Such a self-cleaning function can be easily realized if, for example, a parallel suction pipe guide is provided in the filter device. Accordingly, suction regions, via which the fluid is supplied on the one hand to the circulation pump and on the other hand to the drain pump, are aligned substantially parallel to one another in the region of the filter device. This facilitates the rinsing off of lint and / or hair or of such solids from the at least one wall region of the filter device by the operation of the drainage pump. In this case, the filter device can be arranged in an inlet-side chamber of the pump housing designed as a pot housing and / or designed in the manner of a pot housing.

However, it can also be provided for an improved self-cleaning function, that in the filter device, a concept is realized in which a suction region or a suction tube of the circulation pump and a suction region or a suction tube of the drainage pump are aligned substantially perpendicular to each other.

Furthermore, a transverse perforation may be provided in the wall region. In such Saugrohrquerlochung is preferably ensured that the number of Transverse holes multiplied by the cross section of the individual transverse hole is greater than a minimum flow cross section of the circulation pump, that is, for example, greater than the diameter of a suction mouth of the circulation pump. As a suction mouth, the entry into that chamber of the circulation pump may be referred to, in which there is a drive wheel or impeller of the pump.

Preferably, the inlet-side chamber of the pump housing has a closure element, wherein after opening of the closure element, the filter device is accessible or can be viewed for maintenance and / or can be removed from the inlet-side chamber. Thus, maintenance of the filter device can be realized in a particularly simple manner, in particular if it is concluded from the measured values of the flow measuring device that the filter device is blocked.

Preferably, the control device is adapted to change a rotational speed and / or a direction of rotation of an electric motor of the circulation pump and / or an electric motor of a drain pump of the pumping system, if a determined based on at least one operating parameter of the circulation pump and / or the drainage pumping capacity of an under deviates from the at least one measured value of the flow measuring device determined delivery capacity of the circulation pump and / or the drain pump. This is based on the finding that by changing the speed of the electric motor, a state can be restored particularly easily, in which the circulation pump or the drain pump actually promotes the desired flow rate. This can be realized, for example, after sucking in air or sucking a foam-water mixture with a high foam content by reducing the rotational speed of the electric motor.

However, the achievable by means of the circulation pump or the drainage pump capacity can also be dependent on a direction of rotation of a drive wheel or impeller of the respective pump. Then, by reversing the direction of rotation at a constant speed, the delivery rate of the circulation pump or the drain pump can be changed. Preferably, the electric motor of the circulation pump and / or the electric motor of the drain pump are designed as variable-speed and flexible in the direction of rotation or variable, permanent-magnet synchronous motors. Because of the use of such electric motors, a desired tightness of the pumping system can be realized particularly easily.

As further advantageous, it has been shown that the control device is designed to detect and / or locate a blockage in the pumping system. For this too, the control device preferably uses the at least one measured value, which is made available to the control device by the flow measuring device. By combining the different measuring methods for detecting the operating states of the pumping system, not only the actual operating states of the circulation pump and / or the drainage pump of the pumping system can be determined more reliably. If, for example, the drainage pump functions, ie the delivery flow determined on the basis of the electricity demand of the drainage pump coincides with the delivery flow, which results taking into account the at least one measured value of the flowmeter, then it can be concluded that there is a blockage in that region of the pumping system which the circulation pump leads or that the blockage is downstream of the circulation pump.

The control device is preferably designed to communicate the presence of the blockage to an operator or a user of the household appliance. The operator or the user of the household appliance can thus be informed about the degree of clogging in particular of a filter device in a suction chamber of the pumping system or be warned accordingly.

Thus, the operator can be presented with concrete cleaning suggestions or maintenance suggestions, such as that a filter device should be cleaned and / or that a suction region of the pumping system should be examined for the presence of the solids and / or foreign bodies causing the blockage. A degree of blockage, in particular the filter device of the pumping system, can by a Decrease in the delivery rate of the circulation pump and / or a drain pump of the pumping system can be detected.

Additionally or alternatively, the control device may be designed to at least reduce the blockage by activating the circulation pump and / or the drain pump of the pump system. It can therefore be achieved in particular by mutual operation of the circulation pump and the drain pump, a corresponding cleaning of the suction side of the pumping system. Thus, the blockage can be at least reduced or at least partially eliminated in a simple manner.

It has also proven to be advantageous if the control device is designed to change a delivery rate of the circulation pump as a function of loading of the laundry drum with items of laundry, and to control the changing of the delivery rate using the at least one measured value of the flow rate meter. So it can be adjusted depending on the laundry load of the laundry drum to the respective load, the amount of water. Here, according to the flow rate or the delivery rate of the circulation pump is changed, for example by changing the speed of an electric motor of the circulation pump. This change in the delivery rate can be controlled particularly easily with the help of the flow measuring device. Thus, by a, in particular variable speed, control of the circulation pump a controllable, load-adequate laundry flow can always be ensured.

In the inventive method for operating a household appliance for the care of laundry, with a tub, in which a arranged to receive the laundry laundry drum is arranged, and with a pumping system, which comprises a circulation pump which a fluid from a lower portion of the tub in a Promotes the upper portion of the tub, a control device of the household appliance controls the circulation pump. In this case, the control device determines, based on at least one operating parameter of the circulation pump, a delivery rate of at least the circulation pump. The household appliance comprises a flow measuring device, by means of which a flow of the fluid is detected by a line of the pumping system. About the direction of the Pumping system, the fluid is supplied to the circulation pump. The control device takes into account at least one measured value of the flow measuring device when determining the delivery rate of the circulation pump. In this way, the delivery rate of the circulation pump is determined particularly reliable. Furthermore, by taking into account the at least one measured value, a delivery rate of an emptying pump of the pumping system can also be determined particularly reliably.

The advantages and preferred embodiments described for the household appliance according to the invention also apply to the method according to the invention and vice versa.

With indications such as "top", "bottom", "front", "rear", "horizontal", "vertical", "depth direction", "width direction", "height direction" and the like are the intended use and proper arrangement of the household appliance and indicated in a given then in front of the device and in the direction of the appliance viewing observer given positions and orientations.

The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and / or in the figures alone can be used not only in the respectively specified combination but also in other combinations or in isolation, without the scope of To leave invention. Thus, embodiments are also included and disclosed by the invention, which are not explicitly shown or explained in the figures, however, emerge and can be produced by separated combinations of features from the embodiments explained. Thus, embodiments and combinations of features are also to be regarded as disclosed which do not have all the features of an originally formulated independent claim. Moreover, embodiments and combinations of features, in particular by the embodiments set out above, are to be regarded as disclosed which go beyond the feature combinations set out in the back references of the claims or deviate therefrom.

Fig. 1

eine schematische Frontansicht eines Haushaltsgeräts zur Pflege von Wäschestücken;

Fig. 2

perspektivisch ein Pumpsystem des Haushaltsgeräts, wobei eine Zirkulationspumpe und eine Entleerungspumpe des Pumpsystems in einem gemeinsamen Pumpengehäuse des Pumpsystems untergebracht sind;

Fig. 3

schematisch den Strömungsweg eines Fluids durch das Pumpsystem, und zwar von einem Zulauf über eine Filtereinrichtung hin zu einem Druckstutzen der Entleerungspumpe, also beim Abpumpen;

Fig. 4

schematisch den Strömungsweg des Fluids durch das Pumpsystem über die Filtereinrichtung hin zu einem Druckstutzen der Zirkulationspumpe, also beim Umpumpen;

Fig. 5

eine teilweise geschnittene Darstellung eines Strömens des Fluids durch das Pumpsystems und der Filtereinrichtung, wobei eine parallele Saugrohrführung realisiert ist;

Fig. 6

eine teilweise geschnittene Darstellung einer Variante des Pumpsystems, bei welcher in den Wänden der Filtereinrichtung Querlöcher vorgesehen sind;

Fig. 7

eine erste Variante einer Durchflussmesseinrichtung, welche ein Schneckenrad umfasst, das in einer Ansaugleitung beziehungsweise in einem Saugstutzen des Pumpsystems angeordnet ist;

Fig.8

eine teilweise geschnittene Darstellung einer Variante des Pumpsystems, bei welcher ein Flügelrad in der Ansaugleitung beziehungsweise in dem Saugstutzen angeordnet ist;

Fig. 9

eine weitere Perspektivansicht der Variante gemäß Fig. 8, bei welcher die Durchflussmesseinrichtung das Flügelrad umfasst;

Fig. 10

eine weitere perspektivische Ansicht der Variante gemäß Fig. 8;

Fig. 11

eine weitere perspektivische Ansicht der Variante gemäß Fig. 8;

Fig. 12

eine weitere perspektivische Ansicht der Variante gemäß Fig. 8, wobei das Flügelrad vergrößert dargestellt ist;

Fig. 13

eine weitere Variante der Durchflussmesseinrichtung, bei welcher ein Schneckenrad in einer Bypassleitung angeordnet ist;

Fig. 14

schematisch den Zusammenhang der elektrischen Antriebsleistung der Zirkulationspumpe in Abhängigkeit von einer Verschmutzung beziehungsweise Verstopfung der Filtereinrichtung;

Fig. 15

das Pumpsystem gemäß Fig. 2, wobei ein Verschlussdeckel von einer einlassseitigen Kammer des Pumpengehäuses abgenommen ist;

Fig. 16

eine teilweise geschnittene, perspektivische Ansicht des Pumpsystems gemäß Fig. 15;

Fig. 17

das Entnehmen der Filtereinrichtung aus dem Pumpengehäuse in einer ersten perspektivischen Darstellung; und

Fig. 18

das Entnehmen der Filtereinrichtung aus dem Pumpengehäuse in einer zweiten perspektivischen Darstellung.

Further advantages, features and details of the invention will become apparent from the claims, the following description of preferred embodiments and from the drawings. Showing:

Fig. 1

a schematic front view of a household appliance for the care of laundry;

Fig. 2

in perspective, a pumping system of the household appliance, wherein a circulation pump and a drain pump of the pumping system are housed in a common pump housing of the pumping system;

Fig. 3

schematically the flow path of a fluid through the pumping system, namely from an inlet via a filter device to a discharge nozzle of the drain pump, ie when pumping;

Fig. 4

schematically the flow path of the fluid through the pumping system through the filter device towards a discharge nozzle of the circulation pump, ie when pumping;

Fig. 5

a partially sectioned view of a flow of the fluid through the pumping system and the filter device, wherein a parallel Saugrohrführung is realized;

Fig. 6

a partially sectioned view of a variant of the pumping system, in which transverse holes are provided in the walls of the filter device;

Fig. 7

a first variant of a flow measuring device, which comprises a worm wheel, which is arranged in an intake pipe or in a suction nozzle of the pumping system;

Figure 8

a partially sectioned view of a variant of the pumping system, in which an impeller is arranged in the intake pipe or in the suction nozzle;

Fig. 9

another perspective view of the variant according to Fig. 8 in which the flow measuring device comprises the impeller;

Fig. 10

a further perspective view of the variant according to Fig. 8 ;

Fig. 11

a further perspective view of the variant according to Fig. 8 ;

Fig. 12

a further perspective view of the variant according to Fig. 8 wherein the impeller is shown enlarged;

Fig. 13

a further variant of the flow measuring device, in which a worm wheel is arranged in a bypass line;

Fig. 14

schematically the relationship of the electrical drive power of the circulation pump in response to contamination or clogging of the filter device;

Fig. 15

the pumping system according to Fig. 2 wherein a closure cap is removed from an inlet side chamber of the pump housing;

Fig. 16

a partially sectioned perspective view of the pumping system according to Fig. 15 ;

Fig. 17

the removal of the filter device from the pump housing in a first perspective view; and

Fig. 18

the removal of the filter device from the pump housing in a second perspective view.

In the figures, identical or functionally identical elements are provided with the same reference numerals.

In Fig. 1 is a highly schematic representation of a household appliance 1 for the care of laundry items, which may be, for example, a washing machine or a washer-dryer. The household appliance 1 comprises a housing 2, in which a laundry drum 3 is rotatably mounted. An axis of rotation of the laundry drum 3 is shown in FIG Fig. 1 oriented perpendicular to the plane of the figure. The household appliance 1 also includes a Lye container 4, which is also arranged in the housing 2, and which surrounds the laundry drum 3. The laundry drum 3 comprises a hollow cylindrical shell and a rear end wall (not shown). The front side of the laundry drum 3 is formed open, so that the laundry drum 3 has a feed opening through which the laundry items can be introduced into a receiving space 5 of the laundry drum 3. The loading opening can be closed by a door 6, which is movably arranged on the housing 2. A high direction (y direction), a width direction (x direction), and a depth direction (z direction) are in Fig. 1 illustrated by a rectangular coordinate system.

In the housing 2 of the household appliance 1, a pumping system 7 is arranged, which comprises a circulation pump 8 and a drain pump 9 (see Fig. 2 ). A first electric motor 10 serves as a drive of the circulation pump 8, and a second electric motor 11 serves as a drive for the drainage pump 9. The circulation pump 8 and the drainage pump 9 are arranged in a common pump housing 12 of the pumping system 7. The circulation pump 8 serves to convey a fluid such as a wash liquor and / or, for example, in a rinse step of a washing program of the household appliance 1, water from a lower portion 13 of the tub 4 in an upper portion 14 of the tub 4 (see Fig. 1 ). In this way, the wash liquor or water is better and above all transported faster in the laundry, as is the case with a solely caused by the rotation of the laundry drum 3 conveying such a fluid.

The fluid originating from the lower region 13 of the tub 4 is supplied to the pumping system 7 and thus also to the circulation pump 8 via a suction line 15, from which a suction connection 16 belonging to the pumping system 7 is provided Fig. 2 is shown in perspective. Via the same suction nozzle 16 or such a line of the pumping system 7, the fluid to be pumped out of the tub 4 by means of the drainage pump 9 is also supplied to the drainage pump 9. A discharge nozzle 17 of the drain pump 9 is in Fig. 2 shown in perspective. The pressure port 17 serves as a water outlet for pumping. A likewise in Fig. 2 in perspective pressure port 18 of the circulation pump 8 serves as a water outlet for the pumping. From the discharge port 18 performs an in Fig. 2 Sectionally shown line 19 to the upper portion 14 of the tub 4 (see Fig. 1 ).

For controlling the circulation pump 8 and the drain pump 9, a control device 20 is provided, which in Fig. 1 is shown schematically. The control device 20 or the control device of the household appliance 1 is designed to operate parameters of the circulation pump 8 and the drain pump 9, such as a rotational speed of the respective electric motor 10, 11, a direction of rotation of means of the electric motors 10, 11 paddle wheels 21, 22 of the respective pump and to detect and evaluate the like. The paddle wheel 21 of the circulation pump 8 is in Fig. 6 can be seen, and the paddle wheel 22 of the drain pump 9 is in Fig. 16 shown. Furthermore, the control device 20 processes the electric current received by the respective electric motor 10, 11, the size of which or the magnitude of which relies on the torque which is applied by the respective blade wheel 21, 22.

In the present case, on the basis of such operating parameters of the circulation pump 8 on the one hand and the drain pump 9 on the other hand on the flow rate of the circulation pump 8 on the one hand and the drain pump 9 on the other hand closed. If the pumped by the respective pump of the pumping system 7 fluid having a known density, so results in a respective current consumption of the electric motor 10, 11 and a respective speed of the paddle wheel 21, 22, a corresponding capacity of the circulation pump 8 and the drain pump 9. The flow or the delivery rate changes, however, if at the same speed of the electric motor 10, 11 or of the paddle wheel 21, 22, a density of the fluid to be delivered changes. On the one hand, the density of the fluid may increase if lint is conveyed together with the wash liquor or the water. On the other hand, the density of the fluid may decrease when the fluid contains comparatively much foam and thus is no longer single-phase, but as a two-phase foam-water mixture. If such changes in density occur, then a characteristic used for determining the delivery rate of the circulation pump 8 or the drainage pump 9 from the control device 20, which can be stored in a memory of the household appliance 1, in particular in a memory of the control device 20, no longer applies unrestricted.

In order nevertheless to be able to determine the actual delivery flow or the actual delivery rate of the circulation pump 8 and the drainage pump 9, the domestic appliance 1 has a flow measuring device or a flow sensor 23, which in Fig. 1 is shown schematically. Via the flow sensor 23, a flow of fluid through the suction nozzle 16 or intake manifold can be detected. It is thus detectable by means of the flow sensor 23, with which volume flow, the fluid of the circulation pump 8 and the drain pump 9 is supplied.

Because the control device 20 takes into account at least one measured value detectable by means of the flow sensor 23 in addition to the operating parameters of the circulation pump 8 or the drain pump 9, the actual delivery rate of the circulation pump 8 or the drainage pump 9 can be determined particularly reliably. For by means of the flow sensor 23, the flow or the flow of the fluid is detected by the suction nozzle 16, that is, by a line through which the circulation pump 8 and the drain pump 9, the fluid is supplied. For this purpose, the flow sensor 23 can detect a flow velocity of the fluid and output corresponding measured values to the control device 20. Due to the known permeable cross section of the suction nozzle 16 can then be inferred to the flow of the fluid.

Due to a derivable knowledge of the volume flow, which can thus be detected by means of the flow sensor 23, for example, the characteristic curve can be adjusted, which at a determined rotational speed of the respective paddle wheel 21, 22 and at a certain, recorded by the respective electric motor 10, 11 current a respective delivery rate of the circulation pump 8 and the drain pump 9.

So on the one hand a blockage of the pumping system 7 can be detected and located. Furthermore, the rotational speed of the respective paddle wheel 21, 22 and / or the Direction of rotation of the respective paddle wheel 21, 22 are changed approximately in the event that the circulation pump 8 and the drain pump 9 sucks air in an undesirable manner. By reducing the rotational speed and / or changing the direction of rotation of the impeller 21, 22 can be ensured in such a case that the circulation pump 8 and the drain pump 9 again the desired flow itself a reduced due to the presence of foam in its density, two-phase Actually promotes fluids.

Out Fig. 2 It can be seen that a removable closure element 25 is arranged on an inlet-side chamber 24 of the pump housing 12. By opening the closure element 25, which may be formed, for example, as a screw cap with a handle portion 26, access to a filter device 27 can be produced, which is arranged in the chamber 24 and in Fig. 3 is shown schematically and in perspective.

In Fig. 3 is also shown by arrows 28, the flow path from the water inlet or suction nozzle 16 to the water outlet or discharge nozzle 17 of the drain pump 9. Analogously, in Fig. 4 Arrows 29, the flow path from the suction nozzle 16 to the discharge nozzle 18 of the circulation pump 8, so to the water outlet used in pumping.

The overall tubular filter device 27 has an inlet 30, via which both the operation of the circulation pump 8 and the operation of the drain pump 9, the coming of the suction nozzle 16 fluid enters an interior 31 of the filter device 27. By way of an outlet 32 which is oriented perpendicularly to the suction nozzle 16, the fluid can pass from the interior 31 into a pressure chamber 33 of the drainage pump 9, in which the paddle wheel 22 of the drainage pump 9 is located (see FIG Fig. 16 ).

Furthermore, the filter device 27 has a wall region 34, which has a first wall part 35 with passage openings 36 (see FIG Fig. 3 ) and a second impermeable trained wall portion 37 comprises. The wall portion 34 is V-shaped, wherein the wall portion 35 with the passage openings 36 and the wall portion 37, which is impermeable, forming the legs of the V-shape. A vertex of the V-shape extends into the interior 31. At the wall portion 34 Fluff and hair can be retained when the fluid passes through the passage openings 36. Furthermore, the wall portion 34 serves as a foreign body trap for retaining larger small parts, so that these small parts or foreign matter can not get into a pressure chamber 38 of the circulation pump 8, in which the paddle wheel 21 of the circulation pump 8 is arranged (see Fig. 6 ). By removing the closure element 25 not only access to the filter device 27 is possible, but the filter device 27 can preferably also be removed from the chamber 24.

Furthermore, in the present case, hair and lint, which are retained on the side of the wall part 35 facing the interior 31, can be removed or rinsed off by a sequential, delayed activation of the circulation pump 8 and then the drain pump 9. Because the fluid, which leaves the filter device 27 via the outlet 32, takes with it the hair and fluff, which are retained on the wall part 35 by means of the filter device 27.

In Fig. 5 is the chamber 24 (see Fig. 2 A first, thick line 39 illustrates the inflow of the fluid via the suction port 16 into the interior 31 of the filter device 27. Another line 40 illustrates the flow of fluid through the filter device 27 and then further over the Pressure chamber 33 of the drain pump 9 (see Fig. 4 ) to the discharge nozzle 17 for pumping. Another line 41 illustrates the flow of fluid from the interior 31 towards a wall 42 of the filter device 27 (see FIG Fig. 4 ), at which the fluid is deflected and thus conveyed to the pressure chamber 38 of the circulation pump 8. In the area of the filter device 27, the lines 40, 41 run parallel. Accordingly, in Fig. 5 a variant of the filter device 27 shown, in which a parallel Saugrohrführung is realized.

In Fig. 6 a variant of the filter device 27 is shown, in which a Saugrohrquerlochung is realized. Again, the thick line 39 illustrates the entry of the fluid through the suction port 16 in an interior 43 of the filter device 27. From this interior space 43, the fluid passes through a plurality of transverse holes 44 to the pressure chamber 38, in which the impeller 22 of the circulation pump. 8 located. Corresponding thin lines 45 illustrate the flow path through the transverse holes 44. An arrow 46 illustrates the leakage of the fluid through the discharge port 18 of the circulation pump 8, and an arrow 47 illustrates the leakage of the fluid through the discharge port 17 of the drain pump 9.

Also at the in Fig. 6 shown variant of the filter device 27 hair and lint are retained on a wall portion of the filter element or the filter device 27, in which the transverse holes 44 are formed, which can be removed by operating the drain pump 9 again from this wall portion. Also at the in Fig. 6 shown variant of the filter device 27, in which the Saugrohrquerlochung is realized, so a self-cleaning of the filter device 27 can be achieved.

In Fig. 7 a variant is shown in which the flow sensor 23 comprises a worm wheel 48 as an impeller. A longitudinal axis 49 of the worm wheel 48 is aligned with a longitudinal axis of the suction nozzle 16. In the manner not shown here, a worm 50 of the worm wheel 48 has at least one portion formed of a magnetic material. A rotation of the worm wheel 48 about the longitudinal axis 49 can thus be detected, for example, by means of a Hall sensor 51 of the flow measuring device. The Hall sensor 51 is in this case arranged on an outer side of the suction nozzle 16.

At the in Fig. 8 the impeller of the flow sensor 23 is not formed as a worm wheel 48, but as impeller 52. Here, a rotation axis 53 of the impeller 52 is perpendicular to a flow direction of the fluid as it passes through the suction nozzle 16. In Fig. 8 the impeller 52 as well as the filter device 27 are shown in section.

As in particular from Fig. 12 but also out Fig. 9 is clearly visible, at least one blade 54 of the impeller 52 has a portion 55 made of a magnetic material or a magnetic rod. The rotation of this portion 55 about the axis of rotation 53 can be detected by means of the Hall sensor 51 of the flow measuring device. From the view in Fig. 9 It can be clearly seen how the impeller 52 is located upstream of the inlet 30 of the filter device 27 in the suction nozzle 16. And also out Fig. 10 It will be readily apparent how, due to the passage of fluid through the suction port 16, the impeller 52 may be placed in rotation about the axis of rotation 53. Out Fig. 11 In turn, it is clear how the fluid can pass through the outlet 32 of the filter device 27 into the pressure chamber 33 of the drainage pump 9.

Fig. 12 shows the impeller 52 of the flow sensor 23 in an enlarged perspective view, wherein the formed of the magnetic material portion 55 of the blade 54 is just at the height of the Hall sensor 51.

At the in Fig. 13 the variant shown, the flow sensor 23 is realized by a worm wheel 56 or (not shown) impeller is arranged in a bypass line 57 and bypass line. On an outer side of the bypass line 57, in turn, the Hall sensor 51 is arranged. The bypass line 57 branches off at a branch point 58 from the suction nozzle 16. At a mouth opening 59 enters a partial flow of the fluid, which has passed through the bypass line 57 and the bypass line, again in the pump housing 12 of the pumping system 7 a. Within the pump housing 12, the fluid to be pumped is then supplied to the circulation pump 8. In the present case, the mouth opening 59 for this purpose is connected to the inlet-side chamber 24 of the pump housing 12 (cf. Fig. 2 ) connected. However, it can also be provided that the mouth opening 59 is connected to the suction nozzle 16.

The flow resistance through the bypass line 57 is so large, in particular due to the arrangement of the worm wheel 56 in the bypass line 57 and a flow-through cross section of the bypass line 57 so small that the main flow of the fluid always via the suction port 16 into the chamber 24 (see Fig. 2 ) entry. However, flowing through the suction nozzle 16 causes the rotation of the worm wheel 56 or such an impeller of the flow sensor 23. This rotation is detected by means of the Hall sensor 51. Also, by providing the parallel measuring flow through the bypass line 57 or bypass line, the flow velocity of the fluid as it flows through the suction nozzle 16 can thus be determined without contact, and thus the volume flow of the fluid, which is supplied to the circulation pump 8 or the drain pump 9. Also by the hydraulic parallel connection of the flow sensor 23 can thus the Flow rate or the flow rate in the suction-side Pumpenanströmung be detected.

Based on Fig. 14 Let the connection between the electrical drive power of the circulation pump 8 and a blockage of the filter device 27 be schematically illustrated. The drive power provided by the electric motor 10 is in this case on an ordinate 62 of an in Fig. 14 Plotted graph 63 shown. In contrast, the degree of clogging is indicated on an abscissa 64 of the graph 63 in percent. A curve 65 schematically illustrates how the drive power of the electric motor 10 of the circulation pump 8 decreases when the filter device 27 is increasingly clogged. With increasing blockage of the filter device 27 increasingly less water passes to the paddle wheel 21 of the circulation pump 8. As a result, a lower drive power of the electric motor 10 is required to cause the rotation of the paddle wheel 21.

If the filter is clogged to 100 percent, then the paddle wheel 21 of the circulation pump 8 turns virtually dry, so that only a small drive power of the electric motor 10 of the circulation pump 8 is required to reach a certain speed of the paddle wheel 21. The pump motor power of the corresponding drive or electric motor 10,11 of the respective pump can be evaluated by the measured variables of the engine speed, the motor current and thus quasi also the engine torque. However, here the clogging of the filter device 27 plays a role, as indicated by the curve 65 in FIG Fig. 14 is illustrated schematically.

In Fig. 15 the pump housing 12 is shown with the closure element 25 removed. Accordingly, the filter device 27 is accessible. Also from the sectional view in Fig. 16 is clearly seen that after opening the closure element 25, the filter device 27 is accessible to a user of the household appliance 1.

In particular from Fig. 17 It can be seen that the closure element 25 may have an external thread 60 which can be brought into engagement with an internal thread 61 provided on the sides of the pump housing 12 in order to fasten the closure element 25 to the pump housing 12 and thus to the Filter device 27 in position to secure. In Fig. 17 However, the filter device 27 is shown taken out of the chamber 24 of the pump housing 12. Fig. 18 shows the taken out of the chamber 24 of the pump housing 12 filter device 27 in a further perspective view.

In the household appliance 1 described above, both pump motors, namely the electric motor 10 of the circulation pump 8 and the electric motor 11 of the drain pump 9, are connected to a common pump pre-chamber, namely the inlet-side chamber 24 of the pump housing 12. This inlet-side chamber 24 can also be referred to as a suction chamber or as a filter chamber if, as is preferred in this case, the filter device 27 is arranged in the chamber 24. In the region of the suction nozzle 16, or downstream of the suction-side filter insert or the suction-side filter device 27, in this case the flow sensor 23 is provided, which makes it possible to detect the flow velocity of the fluid at a location with a known flow-through cross-section.

As described here, the flow velocity can be determined contactlessly by means of the Hall sensor 51 or directly, for example, by using a turbine wheel meter. Furthermore, as a flow measuring device and a magneto-inductive flow meter can be used. The flow sensor 23 can be integrated into the flow before the filter element or the filter device 27 or after the filter device 27. In the figures, the flow sensor 23 is shown integrated in the suction-side pump flow, with reference to FIGS Fig. 13 variant described a hydraulic parallel connection of the flow sensor 23 is realized. Here, the flow sensor 23 is arranged on or in the bypass line 57, and the flow sensor 23 still makes it possible to detect the flow velocity and thus the volume flow in the suction nozzle 16.

Furthermore, in the present case, the water supply or the liquor supply via the common suction nozzle 16 is realized. However, the outlet for the waste water and the outlet for pumping are each realized separately, so that the pressure port 18 are provided for the function of pumping and the discharge nozzle 17 for the function of dewatering. Preferably, for the pumping system 7 common, by removing the closure member 25 accessible and preferably removable filter device 27 or such a filter system provided. As a result, lint and / or foreign matter can be kept away from the paddle wheels 21, 22 of the circulation pump 8 and the drainage pump 9. In addition, it can be provided that such a filter device keeps lint and / or foreign bodies away from an impeller of the flow sensor 23.

The electric motors 10, 11 of the pumps are preferably designed as synchronous motors with permanent magnets, ie as permanent-magnet synchronous motors, which are driven or driven by a common inverter electronics. Such an inverter electronics can be integrated in the control device 20. In particular, a corresponding relay can then switch the respective electric motor 10, 11 to be triggered.

By means of the integrated flow sensor 23, which detects the volume flow of the fluid which passes through the suction nozzle 16, and the operating data or operating parameters of the circulation pump 8 and the drain pump 9, the delivery rate of the circulation pump 8 and the drain pump 9 can be determined. By evaluating the measured values supplied by the flow sensor 23 and additionally the operating parameters, it is then possible, for example, to obtain information about the degree of clogging of the pumping system 7 or else further routes of the fluid or water through the tub 4. The evaluation of the detected measured variables on the degree of clogging of the pumping system 7 or other waterways can be evaluated for the user or such an operator of the household appliance 1. Thus, the user can be presented with concrete cleaning suggestions or maintenance suggestions, such as that the chamber 24 and / or the filter device 27 inserted into the chamber 24 should be cleaned. A need for cleaning is illustrated by the decrease in pump drive power. Furthermore, in response to such a decrease in the driving power of the pump, respective cleaning methods may be provided, in particular, by alternately driving the circulation pump 8 and the drain pump 9.

Depending on the load of the laundry drum 3 with laundry items, the amount of water or the flow of the fluid can be changed, which the circulation pump 8 delivers from the lower region 13 of the tub 4 to the upper region 14 of the tub 4 (see FIG Fig. 1 ). This adaptation of the delivery flow or the delivery rate of the circulation pump 8 can be made by a speed control of the electric motor 10 of the circulation pump 8 and controlled by means of the flow sensor 23. Thus, a controllable, load-adequate laundry flow can always be ensured in particular by a variable-speed control of the circulation pump 8.

LIST OF REFERENCE NUMBERS

1. 1 home appliance
2. 2 housings
3. 3 laundry drum
4. 4 tubs
5. 5 recording room
6. 6 door
7. 7 pumping system
8. 8 circulation pump
9. 9 drain pump
10. 10 electric motor
11. 11 electric motor
12. 12 pump housings
13. 13 lower area
14. 14 upper area
15. 15 suction line
16. 16 suction nozzles
17. 17 discharge nozzle
18. 18 discharge nozzles
19. 19 line
20. 20 control device
21. 21 bucket wheel
22. 22 bucket wheel
23. 23 flow sensor
24. 24 chamber
25. 25 closure element
26. 26 handle part
27. 27 Filter device
28. 28 arrow
29. 29 arrow
30. 30 inlet
31. 31 interior
32. 32 outlet
33. 33 pressure chamber
34. 34 wall area
35. 35 wall part
36. 36 passage opening
37. 37 wall part
38. 38 pressure chamber
39. 39 line
40. 40 line
41. 41 line
42. 42 wall
43. 43 interior
44. 44 cross hole
45. 45 line
46. 46 arrow
47. 47 arrow
48. 48 worm wheel
49. 49 longitudinal axis
50. 50 snail
51. 51 Hall sensor
52. 52 impeller
53. 53 rotation axis
54. 54 scoop
55. 55 section
56. 56 worm wheel
57. 57 Bypass line
58. 58 branch point
59. 59 mouth opening
60. 60 external thread
61. 61 internal thread
62. 62 ordinates
63. 63 graph
64. 64 abscissa
65. 65 curve

Claims (15)

Domestic appliance (1) for the care of items of laundry, comprising a tub (4) in which a laundry drum (3) designed to receive the items of laundry is arranged, with a pumping system (7) comprising a circulation pump (8) by means of which a fluid from a lower portion (13) of the tub (4) in an upper portion (14) of the tub (4) is conveyed, and with a control device (20) for driving the circulation pump (8), wherein the control device (20) adapted thereto is, based on at least one operating parameter of the circulation pump (8) to determine a delivery rate of at least the circulation pump (8), characterized in that the household appliance (1) comprises a flow measuring device (23), by means of which a flow of the fluid through a conduit (16) of the pumping system (7) can be detected, via which the fluid of the circulation pump (8) can be supplied, wherein the control device (20) is designed to i st, when determining the delivery rate of the circulation pump (8) to take into account at least one measured value of the flow measuring device (23). Domestic appliance (1) according to claim 1, characterized in that the flow measuring device (23) in the line (16) of the pumping system (7) arranged impeller (48, 52). Domestic appliance (1) according to claim 1 or 2, characterized in that the flow measuring device (23) comprises an impeller (56) which is arranged in a bypass line (57) which from a branch point (58) of the line (16) of the pumping system (7) leads to a mouth opening (59), to which the bypass line (57) to a chamber (24) of a pump housing (12) of the pumping system (7) and / or to the line (16) of the pumping system (7) is connected , Domestic appliance (1) according to claim 2 or 3, characterized in that by means of a on an outer side of the line (16) of the pumping system (7) and / or on an outer side of the bypass line (57) arranged sensor (51) Flow measuring device (23) a rotation of the impeller (48, 52, 56) is detected without contact. Domestic appliance (1) according to one of the preceding claims, characterized in that the flow measuring device (23) is designed as a magneto-inductive flow meter. Domestic appliance (1) according to one of the preceding claims, characterized in that the pumping system (7) comprises a drainage pump (9), via which the fluid can be supplied via the line (16), wherein the circulation pump (8) and the drainage pump (9) in a common pump housing (12) of the pumping system (7) are arranged. Domestic appliance (1) according to one of the preceding claims, characterized in that in the line (16) of the pumping system upstream of the flow measuring device (23) and / or downstream of the flow measuring device (23) a filter device (27) is arranged. Domestic appliance (1) according to claim 6 and 7, characterized in that the filter device (27) in an inlet-side chamber (24) of the pump housing (12) is arranged, from which the fluid of the drain pump (9) can be fed. Household appliance (1) according to claim 8, characterized in that the filter device (27) has at least one wall region (34) designed to retain solids from the fluid, from which solids can be removed by operating the drainage pump (9). Domestic appliance (1) according to claim 8 or 9, characterized in that the inlet-side chamber (24) of the pump housing (12) has a closure element (25), wherein after opening of the closure element (25), the filter device (27) accessible for maintenance and / or from the chamber (24) can be removed. Domestic appliance (1) according to one of the preceding claims, characterized in that the control device (23) is adapted to a speed and / or a direction of rotation of an electric motor (10) of the circulation pump (8) and / or an electric motor (11) of a drainage pump (9) of the pumping system (7), if one based on at least one operating parameter of the circulation pump (8) and / or or the drainage pump (9) determined delivery rate of a determined using the at least one measured value of the flow measuring device (23) conveying capacity of the circulation pump (8) and / or the drain pump (9) differs. Domestic appliance (1) according to one of the preceding claims, characterized in that the control device (23) is adapted to detect and / or locate a blockage in the pumping system (7). Domestic appliance (1) according to claim 12, characterized in that the control device (23) is adapted to communicate to an operator the presence of the obstruction and / or by driving the circulation pump (8) and / or a drain pump (9) of the pumping system ( 7) at least reduce the blockage. Domestic appliance (1) according to any one of the preceding claims, characterized in that the control device (23) is adapted to change depending on a load of the laundry drum (3) with laundry a delivery rate of the circulation pump (8), and changing the flow rate using the at least one reading of the flow meter (23). Method for operating a domestic appliance (1) for the care of items of laundry, comprising a tub (4) in which a laundry drum (3) designed to receive the items of laundry is arranged, with a pumping system (7) comprising a circulation pump (8), which conveys a fluid from a lower region (13) of the tub (4) into an upper region (14) of the tub (4), wherein a control device (23) of the domestic appliance (1) controls the circulation pump (8), the control device (23) based on at least one operating parameter of the circulation pump (8) determines a delivery rate of at least the circulation pump (8), characterized in that the domestic appliance (1) a flow measuring device (23), by means of which a flow of the fluid through a line (16) of the pumping system (7) is detected, via which the fluid of the circulation pump (8) is supplied, wherein the control means (23) in determining the flow rate of Circulation pump (8) takes into account at least one measured value of the flow measuring device (23).

Images