Laundry care appliance with a control device

Abstract

The present invention relates to a laundry care appliance 100 comprising a tub 105, a laundry drum 107, wherein the laundry drum 107 is arranged in the tub 105 and is rotatable by a drum drive 109 of the laundry care appliance 100, a fresh water supply device 118-1, wherein the tub 105 has a drain opening 111, a ventilation element 131, which is designed to supply an air flow to the tub 105, a state detection element 129 for detecting a state of the laundry care appliance 100 and a controller 119, which is connected for control purposes to the ventilation element 131, the drum drive 109 and the state detection element 129 and which is designed to initiate a method step if the state detected by the state detection element 129 indicates that in the tub 105 and / or in the washing drum 107 the formation of foam is promoted or foam has formed.The controller 119 is configured to activate the ventilation element 131 in the method step when the state detected by the state detection element 129 is an exceeding of a fill level threshold value 147, an exceeding of a predetermined minimum speed and / or a detection of foam in order to reduce foam present in the tub 105 and / or in the laundry drum 107 and / or to prevent the formation of foam in the tub 105 and / or in the laundry drum 107.

Description

[0001] The present invention relates to a laundry care appliance with a control system.

[0002] In a conventional laundry care appliance, excessive foaming can occur in the detergent dispenser when the washing drum is rotating and / or when an overdose of laundry care substance is present, if the level of washing liquid in the detergent dispenser is so high that the rotating laundry drum is submerged in the detergent dispenser. Such excessive foaming can under certain circumstances lead to the foam from the detergent dispenser penetrating into the detergent dispenser drawer of the laundry care appliance and to detergent overflowing from the detergent dispenser drawer of the laundry care appliance, thus soiling the area in which the laundry care appliance is installed. Such excessive foaming can under certain circumstances also negatively affect the laundry care result of a laundry care process in the laundry care appliance.

[0003] Foam control strategies are known from the prior art in which the amount of foam present in the tub is attempted to be reduced by alternately pumping out washing liquid and refilling with fresh water. However, this often has the disadvantage that the resulting dilution of the laundry care substance in the washing liquid can often adversely affect the laundry care result and that water consumption increases.

[0004] EP 2 158 350 B1 discloses a method for treating laundry items.

[0005] DE 10 2017 222 088 A1 discloses a foam-dependent adjustment of the dosage amount of laundry care substance supplied to a laundry care appliance.

[0006] The object underlying the invention is to provide a laundry care appliance in which the amount of foam occurring during a laundry care process can be effectively reduced or its formation can be effectively avoided.

[0007] This object is achieved by the subject matter having the features according to the independent claims. Advantageous embodiments are the subject of the dependent claims, the description, and the drawings.

[0008] According to a first aspect, the object of the invention is achieved by a laundry care appliance, comprising a tub for receiving washing liquid, a laundry drum for receiving laundry, wherein the laundry drum is arranged in the tub and is rotatable by a drum drive of the laundry care appliance, a fresh water supply device which is fluidly connected to the tub by a fresh water line, wherein the tub has a drain opening, a ventilation element which is designed to supply an air stream to the tub, a state detection element for detecting a state of the laundry care appliance and a controller which is connected to the ventilation element, the drum drive and the state detection element and which is configured to initiate a method step when the state detected by the state detection element indicatesthat the formation of foam is promoted or foam has formed in the tub and / or in the laundry drum, wherein the controller is designed to activate the ventilation element in the method step to supply an air flow to the tub and / or to the laundry drum if the state detected by the state detection element is an exceeding of a fill level threshold, an exceeding of a predetermined minimum speed or a detection of foam, in particular if the laundry has absorbed a predetermined amount of washing liquid, in order to reduce foam present in the tub and / or in the laundry drum and / or to prevent the formation of foam in the tub and / or in the laundry drum.

[0009] In particular, the predetermined amount of washing liquid is the amount of washing liquid required to care for the laundry placed in the washing drum. The predetermined amount of washing liquid can depend on the amount and / or type of laundry and / or a selected laundry care process. Preferably, the predetermined amount of washing liquid is reached when the laundry is completely saturated with washing liquid, i.e., the laundry has absorbed the maximum possible amount of washing liquid.

[0010] This achieves the technical advantage that by supplying the air flow generated by the ventilation element into the tub and / or the laundry drum of the laundry care appliance, foam present in the tub can be effectively combated or the formation of foam can be prevented, since the air flow generated can immediately destroy any foam bubbles that have formed and any foam bubbles that may form.

[0011] A condition that favors the formation of foam occurs particularly when the washing drum is in contact with the washing liquid containing a laundry care substance and agitates it due to the rotation of the drum, or when the washing liquid contains too high a proportion of laundry care substance, i.e., an overdose. These conditions can also occur together and, depending on the specific severity of the condition, particularly favor the formation of foam.To detect such conditions, a fill level detection element for detecting a fill level of washing liquid in the tub, a flow element for detecting the amount of washing liquid supplied, a speed detection element for detecting the speed of the washing drum or the drum drive or a sensor for detecting an amount of laundry care substance supplied and / or a concentration of the laundry care substance in the washing liquid, for example a surfactant sensor, are provided in particular as a condition detection element.

[0012] The particular advantage is achieved by the fact that a foam-promoting condition can be detected before the foam has formed, and measures can be initiated to prevent the formation of foam without having to terminate the foam-promoting condition itself. This means that the laundry care process can otherwise be carried out as if no foam were present, allowing the process to be carried out in a particularly resource-saving manner without affecting the result of the process. In particular, a renewed supply of washing liquid and a reduction in the concentration of the laundry care substance are avoided.

[0013] The condition detection element can, in particular, also be a foam detection device to detect foam that has already formed in the tub and / or the laundry drum. A foam detection device can, for example, be a fill level detection element, a pressure detection element, or an optical sensor.

[0014] As a prerequisite for initiating the method step for activating the ventilation element, the control system determines, in particular, that the drum drive rotates the laundry drum and that the fill level of washing liquid in the tub is sufficiently high for the rotating laundry drum to immerse itself in the laundry drum, which corresponds to the usual parameters required for foam formation in the tub, particularly when the washing liquid is oversaturated with laundry care substance. Such oversaturation of the washing liquid can also be understood as an overdose of the laundry care substance, for example, if the customer doses more laundry care substance than is required for the laundry care process for the laundry to be cared for.In particular, the requirement can already be met from the start of a washing cycle, whereby it can be assumed that a laundry care substance has been added to the washing liquid to support the treatment of the laundry.

[0015] Thus, the control system can intervene in a particularly preventative manner, i.e. before foam can even form in the tub and / or the washing drum, by activating the ventilation element, so that effective foam control or even complete foam avoidance is possible.

[0016] As an alternative prerequisite for initiating the process step for activating the ventilation element, the controller can determine that foam has already formed in the tub and / or in the laundry drum. Thus, the controller can intervene, in particular with the same preventative measure by activating the ventilation element, enabling effective foam control without significantly changing the washing process. Monitoring for the alternative prerequisite has the particular advantage that other possibilities for foam formation than the conditions mentioned above can be taken into account and eliminated, as the process step can be initiated even if an amount of foam greater than a predetermined level is detected.It is particularly advantageous to determine whether the laundry has already absorbed the predetermined amount of washing liquid in order to initiate further measures to reduce foam, for example pumping the washing liquid out of the laundry care appliance, whereby the further washing process can be continued despite the further measure without adding more washing liquid.

[0017] The present invention thus prevents excessive foaming and also ensures that no unnecessary dilution of the washing liquid occurs, thus eliminating the need to add laundry care substance. Laundry care efficiency does not decrease during the laundry care process despite the foam control measures. Furthermore, fresh water consumption is reduced, potentially also reducing the energy consumption of the laundry care appliance.

[0018] A laundry care appliance is a device used for laundry care, such as a washing machine or a washer-dryer, especially a washer-dryer that has a washing and drying function. In particular, such a laundry care appliance is understood to be a household laundry care appliance. That is, a laundry care appliance that is used in the context of household management and with which laundry is treated in normal household quantities.

[0019] In an advantageous embodiment, the state detection element is a fill level detection element connected to the controller for detecting a fill level of washing liquid in the tub, and the controller is designed to activate the ventilation element for supplying an air flow to the tub when the drum drive rotates the laundry drum and when the fill level of washing liquid in the tub detected by the fill level detection element is above a fill level threshold value, wherein the fill level threshold value corresponds to the fill level which is necessary for the rotating laundry drum to immerse itself in the washing liquid in order to reduce foam present in the tub and / or in the laundry drum and / or to prevent the formation of foam in the tub and / or in the laundry drum.

[0020] This achieves the technical advantage that a condition for foam formation in the tub and / or in the washing drum can be detected by the control system through a rotation of the washing drum, which comes into contact with the washing liquid, whereby a preventive measure to avoid foam can be initiated.

[0021] In an advantageous embodiment, the control is designed to activate the ventilation element for supplying an air flow to the tub and / or to the laundry drum when the drum drive rotates the laundry drum at a minimum speed and when the filling level of washing liquid in the tub detected by the filling level detection element is above the filling level threshold value, wherein the minimum speed is in particular 50 revolutions per minute.

[0022] This achieves the technical advantage that rotation of the laundry drum at the minimum speed for the control is an additional advantageous condition that foam formation occurs in the tub and / or in the laundry drum.

[0023] The minimum speed corresponds in particular to the system speed of the laundry drum, whereby the system speed corresponds to the speed of the laundry drum at which the laundry held in the laundry drum is attached to the laundry drum due to the centrifugal force acting on the laundry and a laundry tunnel is formed inside the laundry.

[0024] The rotation of the laundry drum at the minimum speed, in particular at a minimum speed of 50 revolutions per minute, in particular at the system speed, ensures during wetting that, for example, washing liquid can fully wet the laundry, since, in particular when the laundry drum rotates at the system speed, the washing liquid can be advantageously injected into a laundry tunnel formed in the laundry, and thus sufficient wetting of the laundry is achieved.

[0025] On the other hand, the minimum speed, in particular the system speed, is sufficiently high so that rotation of the laundry drum at the minimum speed, in particular the system speed, makes the occurrence of foam (in connection with a correspondingly high filling level of washing liquid in the tub) likely, and thereby necessitates the foam control measures according to the present invention.

[0026] In particular, the minimum speed, in particular the system speed, is more than 50 revolutions per minute, in particular more than 60 revolutions per minute, in particular more than 70 revolutions per minute, in particular more than 80 revolutions per minute, in particular more than 90 revolutions per minute and in particular more than 100 revolutions per minute.

[0027] In an advantageous embodiment, a distance between the lowest area of ​​the tub and the lowest area of ​​the laundry drum corresponds to the fill level threshold value.

[0028] This achieves the technical advantage that the corresponding distance enables a simple and effective determination of the fill level threshold value or the corresponding fill level.

[0029] For the rotating laundry drum to be immersed in the washing liquid, contact must obviously exist between the lowest part of the laundry drum and the washing liquid contained in the tub. Since the height of the lowest part of the tub determines the zero level of the corresponding fill level or fill level threshold, the distance between the lowest part of the tub and the lowest part of the laundry drum defines the corresponding fill level or fill level threshold required for the rotating laundry drum to be immersed in the washing liquid.

[0030] In an advantageous embodiment, the ventilation element has a ventilation duct with an outlet opening which is fluidically connected to the tub or to the laundry drum, and the ventilation element has a fan which is arranged in the ventilation duct and is designed to blow air from the ventilation duct through the outlet opening into the tub and / or into the laundry drum.

[0031] This achieves the technical advantage that the fan arranged in the ventilation duct can supply an effective air flow through the outlet opening to the tub and / or the laundry drum.

[0032] In an advantageous embodiment, the tub has an appliance opening that can be closed by a door of the laundry care appliance, wherein the appliance opening is sealed by an elastic sleeve of the laundry care appliance, and wherein the outlet opening of the ventilation duct is arranged on the plastic sleeve.

[0033] This achieves the technical advantage that the arrangement of the outlet opening of the ventilation duct on the elastic sleeve ensures an effective supply of air into the tub, in particular directly into the laundry drum.

[0034] In an advantageous embodiment, the ventilation element comprises a heating element for heating the air flow, in particular the air flow provided by the fan, wherein the controller is designed to activate the heating element and the ventilation element to supply a heated air flow to the tub and / or to the laundry drum when the state detected by the state detection element is an exceeding of a fill level threshold, an exceeding of a predetermined minimum speed and / or a detection of foam, wherein the controller is designed in particular to activate the heating element and the ventilation element to supply a heated air flow when the drum drive rotates the laundry drum and when the fill level of washing liquid in the tub detected by the fill level detection element is above the fill level threshold.

[0035] This achieves the technical advantage that the air flow, in particular the air flow heated by the heating element, achieves particularly effective foam control or foam prevention.

[0036] In an advantageous embodiment, the laundry care appliance has a pumping device which is fluidically connected to the tub, in particular to the drain opening, and which is control-technically connected to the controller, wherein the controller is designed to activate the pumping device for pumping washing liquid out of the tub when the condition detected by the condition detection element is an exceeding of a fill level threshold value, an exceeding of a predetermined minimum speed and / or a detection of foam, wherein the controller is designed in particular to heat the laundry after pumping washing liquid out of the tub by circulating hot air which is provided by the ventilation element comprising a heating element.

[0037] This achieves the technical advantage that, by pumping the washing liquid out of the tub, the level of washing liquid in the tub drops below the fill level threshold, preventing the rotating laundry drum from immersing itself in the washing liquid, which can hinder the formation of foam. Furthermore, some of the foam is removed from the tub along with the pumped-out washing liquid.

[0038] In particular, if the laundry in the washing drum is already wetted with a sufficient amount of washing liquid and laundry care substance, in particular if it is completely saturated, it is not necessary to add further fresh water during the further course of the laundry care process.

[0039] If, after the washing liquid has been pumped out, there is no longer any warm washing liquid available to heat the laundry, the ventilation element comprising a heating element can advantageously blow a heated air stream into the tub in order to effectively heat the laundry held in the washing drum.

[0040] In an advantageous embodiment, the fill level detection element is designed as a pressure detection element for detecting a pressure of washing liquid in the tub.

[0041] This achieves the technical advantage that the pressure of washing liquid detected by the pressure sensing element can be effectively correlated with a corresponding filling level of washing liquid in the tub.

[0042] Thus, the fill level threshold is particularly correlated with a corresponding pressure threshold.

[0043] In an advantageous embodiment, the fill level detection element, in particular the pressure detection element, comprises a riser pipe arranged in sections in the lye container, wherein a pressure sensor for detecting a pressure in the riser pipe is arranged at an end of the riser pipe facing away from the lye container in order to detect the pressure in the lye container.

[0044] This provides the technical advantage of enabling effective pressure detection in the lye container.

[0045] In this case, the riser pipe has in particular an end facing the suds container, into which end, for example when the washing liquid level in the suds container rises, the washing liquid can penetrate into the riser pipe and compresses the air column above in the riser pipe, so that the pressure sensor, which is arranged at the end of the riser pipe facing away from the suds container, can detect the corresponding compression of the air column as a pressure increase and can correlate it with an increase in washing liquid in the suds container or with foam development in the suds container.

[0046] In an advantageous embodiment, the riser pipe is designed as a siphon, which comprises a curved section that can be filled with washing liquid, and which comprises a vertically extending riser pipe section that can be filled with air and in which the pressure sensor is arranged.

[0047] This achieves the technical advantage that the curved section of the riser pipe designed as a siphon ensures that a stable column of washing liquid is maintained in the riser pipe in order to carry out an effective pressure measurement.

[0048] In an advantageous embodiment, the riser pipe has a riser pipe opening at an end facing the tub, which is fluidically connected to the interior of the tub to allow washing liquid and / or foam to penetrate from the interior of the tub into the riser pipe, wherein the riser pipe is mounted in the tub in particular in such a way that the liquid level of washing liquid in the tub is arranged below the riser pipe opening during the detection time period.

[0049] This achieves the technical advantage that the riser opening allows washing liquid and / or foam to penetrate the riser, thus enabling pressure measurement. If the washing liquid level is below the riser opening during the detection period, a pressure signal detected by the controller during the detection period indicates the penetration of foam into the riser.

[0050] In an advantageous embodiment, the control is designed to deactivate the ventilation element again after a predetermined period of time, or the control is designed to deactivate the ventilation element again when the drum drive rotates the laundry drum at a speed which is less than or equal to a maximum speed.

[0051] This achieves the technical advantage that when the laundry drum rotates at a speed below the maximum speed, the speed remains correspondingly low, so that the risk of foam formation is very low, allowing the ventilation element to be deactivated by the control system. Alternatively, the control system can also deactivate the ventilation element after a sufficiently long predetermined period of time, when the risk of foam formation no longer exists.

[0052] In an advantageous embodiment, the laundry care appliance has a heating element arranged in the tub, which is designed to directly heat the washing liquid arranged in the tub.

[0053] This achieves the technical advantage that, in addition to the heating element arranged in the ventilation element, the heating element arranged in the tub enables direct heating of the washing liquid in the tub.

[0054] In an advantageous embodiment, the condition detection element of the laundry care appliance is a foam detection device for detecting foam, which is control-technically connected to the controller. The controller is configured to activate the ventilation element to supply an air flow to the tub when the foam detection device detects foam. Alternatively or additionally, the ventilation element can be activated when the drum drive rotates the laundry drum, if the fill level of washing liquid in the tub, detected by the fill level detection element, is above a fill level threshold.

[0055] This achieves the technical advantage that the fan activation can be controlled particularly optimally by the control system due to the additional detection of foam by the foam detection device.

[0056] In an advantageous embodiment, the tub has a feed element which is fluidically connected to the drain opening by a pumping line, the laundry care appliance comprises a pump which is designed to pump washing liquid out of the tub through the drain opening during a pumping process and to pump the pumped-out washing liquid through the pumping line and through the feed element back into the tub, and the foam detection device comprises a power detection element for detecting an electrical power parameter of the pump, wherein the controller is designed to activate the pump during a detection period as part of the pumping process, and wherein the controller is designed to determine the presence of foam in the tub,if, during the detection period, the electrical power parameter of the pump detected by the power detection element is less than a power parameter threshold value, and if, during the detection period, the fill level in the tub detected by the fill level detection element is greater than another fill level threshold value.

[0057] This achieves the technical advantage of enabling particularly effective foam detection. If the electrical performance parameter of the pump evaluated by the control system, in particular the motor current, is lower than a performance parameter threshold, the control system can effectively determine that the pump is only pumping air during idle operation. If, at the same time, the wash liquid level in the tub is greater than another level threshold, the corresponding level value must be based on the presence of foam, since the pump is only pumping air even though wash liquid is still present in the tub.

[0058] In particular, foam detection also includes level measurement via pressure measurement, especially during the pumping process, measurement of the presence of foam by electrodes, and / or methods based on machine learning that use all available sensor signals.

[0059] According to a second aspect, the object is achieved by a method for reducing foam in a laundry care appliance, wherein the laundry care appliance has a tub for receiving washing liquid, a laundry drum for receiving laundry, wherein the laundry drum is arranged in the tub and is rotatable by a drum drive of the laundry care appliance, a fresh water supply device which is fluidly connected to the tub via a fresh water line, which has a drain opening, a ventilation element which is designed to supply an air stream to the tub, a state detection element for detecting a state of the laundry care appliance and a controller which is control-relatedly connected to the pump, the ventilation element, the drum drive and the state detection element, wherein the method initiates a method step,if the condition detected by the condition detection element indicates that foam formation is favored or has formed in the tub and / or in the laundry drum, the method step comprising: activating the ventilation element to supply an air flow to the tub and / or to the laundry drum by the controller if the condition detected by the condition detection element is that a fill level threshold has been exceeded, a predetermined minimum speed has been exceeded, and / or foam has been detected, in particular if the laundry has absorbed a predetermined amount of washing liquid, in order to reduce foam present in the tub and / or to prevent the formation of foam in the tub. A method for reducing foam in a laundry care appliance is also understood to mean a method in which the formation of foam is prevented,because foam reduction measures can prevent foam if the process steps are carried out proactively before foam is formed.

[0060] Alternatively or additionally, activation can occur when the drum drive rotates the laundry drum and when the level of washing liquid in the tub detected by the level detection element is above a level threshold, wherein the level threshold corresponds to the level necessary for the rotating laundry drum to be immersed in the washing liquid.

[0061] This achieves the technical advantage of ensuring effective foam reduction and foam avoidance.

[0062] The embodiments mentioned for the laundry care appliance according to the first aspect are also embodiments for the method according to the second aspect.

[0063] Embodiments of the invention are illustrated in the drawings and are described in more detail below.

[0064] They show: Fig. 1 shows a schematic view of a laundry care appliance according to one embodiment; Fig. 2 shows a schematic view of a laundry care appliance with a controller according to one embodiment; Fig. 3 shows a graphical representation of a laundry care process according to a first embodiment; and Fig. 4 shows a schematic representation of a method for reducing foam in a laundry care appliance according to one embodiment.

[0065] Fig. 1 shows a schematic view of a general laundry care appliance 100 according to one embodiment, such as a washing machine. The laundry care appliance 100 comprises a dispenser tray 101 into which detergent or other laundry care substances can be poured. The laundry care appliance 100 has a device housing 102 with a device opening 104, which can be closed by a device door 103 for loading the laundry care appliance 100. In addition, the laundry care appliance 100 also has operating elements 106 for operating the laundry care appliance 100.

[0066] Fig. 2 shows a schematic view of a laundry care appliance with a controller according to an embodiment.

[0067] The laundry care appliance 100 has a tub 105 for holding washing liquid and a laundry drum 107 for holding laundry. The laundry drum 107 is arranged in the tub 105. A drum drive 109 rotates the laundry drum 107. The tub 105 has a drain opening 111.

[0068] The laundry care appliance 100 comprises a fresh water supply device 118-1, which has a Fig. 2 The not shown dispenser tray 101 of the laundry care appliance 100 supplies fresh water through a fresh water line 118-2 to the tub 105 or the laundry held in the laundry drum 107.

[0069] In particular, in a particular embodiment, the laundry care appliance 100 comprises a feed element 113. The drain opening 111 is fluidically connected to the feed element 113 by a pumping line 115, wherein a pump 117 for pumping washing liquid through the pumping line 115 is arranged in the pumping line 115. In the particular embodiment, the pump 117 can pump washing liquid through the drain opening 111 from the tub 105 during a Fig. 2 pumping process (not shown) into the pumping line 115 and resupply the washing liquid through the pumping line 115 and through the supply element 113 to the tub 105 and the laundry drum 107. This allows the washing liquid to be effectively pumped through the pumping line 115 during a laundry care process and resupplied to the laundry in the laundry drum 107.

[0070] The laundry care appliance 100 further comprises a controller 119, which is connected in particular to the pump 117 by a first control connection 121, which is connected to the drum drive 109 for rotating the laundry drum 107 by a second control connection 123, and which is connected by a third control connection 125 to the fresh water supply device 118-1 for supplying washing liquid into the laundry drum 107.

[0071] The controller 119 is further connected for control purposes by a fourth control connection 127 to a state detection element in the form of a fill level detection element 129 for detecting a state of the laundry care appliance 100, which represents, for example, a fill level in the tub 105.

[0072] The laundry care appliance 100 is further characterized in that it has a ventilation element 131 which is designed to supply an air flow to the laundry received in the laundry drum 107.

[0073] In particular, the ventilation element 131 has a ventilation duct 133 with an outlet opening 135, which is fluidically connected to the tub 105. A corresponding intake opening of the ventilation duct 133 for sucking in air is provided in the Fig. 2 not shown. The ventilation element 131 further comprises a fan 137, which is arranged in the ventilation duct 133 and is designed to blow air from the ventilation duct 133 through the outlet opening 135 into the tub 105. A corresponding air flow can advantageously be used to dry laundry held in the laundry drum 107.

[0074] In particular, the exit opening 135 is arranged at a Fig. 2 The ventilation element 133 is arranged in a plastic sleeve (not shown) of the laundry care appliance 100, the plastic sleeve sealing the appliance opening 104 of the laundry care appliance 100. In particular, in such an embodiment, the air flow can be supplied directly to the laundry drum 107 with the ventilation element 133.

[0075] As in the Fig. 2 As shown schematically, the ventilation element 131 further comprises, in particular, a heating element 139 for supplying a heated air flow into the tub 105 and / or into the laundry drum 107. The heating element 139 is arranged, in particular, downstream of the fan 137 in the ventilation duct 133, so that the air moved by the fan 137 can be effectively heated by the heating element 139 and the heated air can then be guided into the tub 105 and / or into the laundry drum 107.

[0076] Accordingly, a supply of heated air can also be used, for example, as part of a drying process following the laundry care process to dry the laundry held in the laundry drum 107. However, the correspondingly heated air can also be used during the laundry care process itself to directly heat the washing liquid held in the tub 105, so that optionally even an additional heating element for heating the washing liquid in the laundry care appliance 100 can be dispensed with.

[0077] It is further noted that the fan 137 and the heating element 139 are Fig. 2 further control connections not shown are connected to the controller 119.

[0078] The fan 137 and the heating element 139 can also be advantageously used in the context of foam control in the tub 105, wherein corresponding foam can be generated by an overdose of laundry care substance into the washing liquid and / or wherein corresponding foam can also be generated by an intensive drum movement at a correspondingly high fill level of washing liquid due to impact.

[0079] In this case, the air supplied to the foam by the ventilation element 131, which can comprise cold air or heated air, causes the foam bubbles of the foam to burst, thereby achieving a timely foam reduction in the tub 105. Furthermore, supplying the air provided by the ventilation element 131 during a laundry care process causes any foam bubbles that form to be immediately destroyed, whereby essentially no foam can form. For further details, please refer to the explanations for the following Fig. 3 referred to.

[0080] The laundry care appliance 100 further comprises an outlet line 141, which is fluidically connected to the circulation line 115. A Fig. 2 The pumping device 143, which is only shown schematically, is designed during a Fig. 2 not shown, to pump washing liquid through the drain opening 111 from the tub 105, through the pumping line 115 and through the outlet line 141 from the laundry care appliance 100.

[0081] Furthermore, the Fig. 2 a distance 145 between a lowermost region of the tub 105 and a lowermost region of the laundry drum 107 is shown, which defines a minimum fill level or fill level threshold 147 of washing liquid in the tub 105 at which the rotating laundry drum 107 is immersed in the washing liquid.

[0082] Fig. 3 shows a graphical representation of a laundry care process according to a first embodiment.

[0083] The Fig. 3 The laundry care process shown in illustrations (a), (b), (c), (d), (e) and (f) shows two different test runs each, once with activated ventilation element 131 (in Fig. 3 highlighted by triangles) and once with deactivated ventilation element 131 (in Fig. 3 highlighted by circles), whereby the laundry drum 107 was filled with a 3 / 4 load and an overdose of laundry care substance was present.

[0084] The Fig. 3 shown first and second curves 140-1, 140-2, third and fourth 140-3, 140-4, fifth and sixth curves 140-5, 140-6, seventh and eighth curves 140-7, 140-8, ninth and tenth curves 140-9, 140-10, as well as eleventh and twelfth curves 140-11, 140-12 each show along the ordinate axis 144 in illustration (a) the speed of the laundry drum 107 of the laundry care appliance 100 in revolutions per minute, in illustration (b) the amount of fresh water in liters supplied to the tub 105 by a fresh water supply device 118-1 of the laundry care appliance 100, in illustration (c) the amount of fresh water in liters supplied by a fill level or- pressure detection element 129 detected pressure in the tub 105 in Pascal, in illustration (d) the speed of a pump 117 of a pumping system in revolutions per minute, in illustration (e) the rotational speed of the fan 137 of the ventilation element 131 in revolutions per minute, and in illustration (f) the temperature of the washing liquid measured by a temperature sensor, in each case as a function of time, which is shown in illustrations (a), (b), (c), (d), (e) and (f) along the abscissa axis 148.

[0085] The first, third, fifth, seventh, ninth and eleventh curves 140-1, 140-3, 140-5, 140-7, 140-9, and 140-11 (in Fig. 3 highlighted by circles) show a laundry care process with a deactivated fan 137, whereas the second, fourth, sixth, eighth, tenth and twelfth curves 140-2, 140-4, 140-6, 140-8, 140-10 and 140-12 (in Fig. 3 highlighted by triangles) shows a state with activated fan 137, as particularly shown by the illustration (e) of the Fig. 3 is clarified.

[0086] In the Fig. 3 In the laundry care process shown, the time period of a laundry care process shown along the abscissa axis 148 in all representations (a), (b), (c), (d), (e) and (f) comprises a range which extends from approximately second 0 to approximately second 1000 of the laundry care process.

[0087] The Fig. 3 The laundry care process shown begins with a first supply time period 149 during which the controller 119 is designed to activate a fresh water supply device 118-1 of the laundry care appliance 100 for supplying fresh water into the tub 105, as can be seen from the illustration (b).

[0088] It can also be seen from illustration (c) that the pressure in the suds container 105 detected by the fill level or pressure detection element 129 also increases during the first supply time period 149 due to the fresh water supplied to the suds container 105.

[0089] During the first feed time period 149, the fan 137 is deactivated, as can be seen from illustration (d).

[0090] The first feed time period 149 is followed by a detection time period 151, which begins with the activation of the rotation of the laundry drum 107, as can be seen from illustration (a). At the beginning of the detection time period 151, the laundry drum 107 is rotated at a minimum speed, in the present special case, for example, at a high system speed of up to 800 revolutions / minute, whereby the laundry received in the laundry drum 107 is pressed against the laundry drum 107 by the acting centrifugal forces, whereby a laundry tunnel is formed within the laundry in the laundry drum 107, into which the pumped washing liquid can advantageously be injected in order to fully and effectively wet the laundry. The corresponding activation of the pump 117 of the pumping system is shown in illustration (d) of the Fig. 3 out.

[0091] As can be seen from illustration (c) of the Fig. 3 As can be seen, the level of washing liquid drops due to the absorption of washing liquid by the laundry and the activation of the pumping process and the pumping of the washing liquid at the beginning of the detection time period, but not necessarily completely, so that depending on the washing situation, at least a small amount of washing liquid remains in the tub 105, into which the rotating laundry drum 107 can dip, which can cause foam formation in the tub 105.

[0092] A corresponding foam formation in the tub 105 can be detected during the detection section in the illustration (c) of the Fig. 3 be detected. If, according to the fifth curve 140-5, the fan 137 is deactivated, the fill level sensor 129 detects a pressure increase due to the formation of foam in the tub 105. Thus, with the state detection element in the form of the fill level sensor 129, a state of the laundry care appliance can be detected which indicates the presence of foam, ie, the state is a detection of foam.

[0093] In particular, the formation of foam cannot be visually detected through the appliance door 103 of the laundry care appliance 100, since the rotation of the laundry drum 107 during the detection phase, which in the present embodiment is approximately 100 revolutions per minute, displaces the foam in the tub 105, and the sharp-edged outer surface of the laundry drum 107 strikes the foam. However, after the laundry drum 107 comes to a standstill, the tub 105 completely fills with foam again.

[0094] If, however, the fan 137 is activated to destroy and dissolve the foam in the tub 105, according to the sixth curve 140-6 in illustration (c), no foam can be detected in the tub 105 due to the significantly reduced pressure value during the detection section, so that an effective preventive avoidance of foam formation can be achieved by activating the fan 137.

[0095] It is emphasized again that effective preventive foam prevention can be achieved solely by the supplied air flow of the fan 139 of the ventilation element 131, without necessarily activating a heating element 139 optionally arranged in the ventilation duct 133. However, the heating element 139 can optionally be activated to heat the air flow, so that the foam is destroyed even more quickly.

[0096] Another aim of the present invention is to prevent the formation of foam in the tub 105, so that a foam detection that can be carried out beforehand in the laundry care appliance 100 is not necessarily necessary.

[0097] According to the present invention, the controller 119 is configured to activate the ventilation element 131 to supply an air flow to the tub 105 when the condition detected by the condition detection element 129 is that a fill level threshold 147 is exceeded and / or a predetermined minimum speed is exceeded. The detected condition is reached, in particular, when the drum drive 109 rotates the laundry drum 107 and when the fill level of washing liquid in the tub 105 detected by the fill level detection element 129 is above a fill level threshold 147, wherein the fill level threshold 147 corresponds to the fill level required for the rotating laundry drum 107 to be immersed in the washing liquid.

[0098] Thus, the two criteria relevant to the controller 119 for activating the ventilation element 131 are, in particular, a sufficiently high fill level of washing liquid in the tub 105 so that the laundry drum 107 is immersed in the washing liquid, and rotation of the laundry drum 107 by the drum drive 109. In alternative embodiments, other criteria may also be used, the presence of which may promote foam formation. Thus, in addition to reaching and exceeding a sufficiently high fill level, a sufficiently high amount of washing liquid supplied, a detected amount of laundry, a type of laundry, a type and / or amount of added laundry care substance or detergent, and / or a selected laundry care process could be further criteria that promote foam formation.

[0099] In order to make the foam control even more effective, it is optionally further possible for the controller 119 to activate a pumping device 143 for pumping washing liquid out of the tub 105 when the state detected by the state detection element 129 is an exceeding of a fill level threshold value 147, an exceeding of a predetermined minimum speed and / or a detection of foam, in particular when the drum drive 109 rotates the laundry drum 107, and when the fill level of washing liquid in the tub 105 detected by the fill level detection element 129 is above the fill level threshold value 147, wherein the fill level threshold value 147 corresponds to the fill level which is necessary for the rotating laundry drum 107 to be immersed in the washing liquid.

[0100] By optionally pumping out washing liquid by means of the pumping device 143, the fill level in the suds container 105 can be advantageously reduced, so that renewed foam formation by the rotating laundry drum 107 can be effectively prevented, and so that foam already present in the suds container 105 disintegrates by itself or is destroyed by the supplied air flow.

[0101] Since the ventilation element 131 of the laundry care appliance 100 has, in particular, a heating element 139 through which heated air can be supplied to the tub 105, subsequent heating of the laundry by the heated air can also be carried out when the washing liquid has been pumped out of the tub 105 by the pumping device 143, as described above.

[0102] Even if foam detection is not absolutely necessary, prior foam detection nevertheless simplifies the corresponding pumping process, as it can effectively prevent renewed foam formation before the heating phase following the wetting phase when the washing liquid is oversaturated with laundry care substance.

[0103] As can be seen from the second curve 140-2 according to the illustration (a) of the Fig. 3 As can be seen, from approximately second 900, the control unit 119 controls the laundry care appliance 100 in such a way that the laundry drum 107 is rotated in particular reversibly at low speeds below a maximum speed critical for foam formation in different directions of rotation, so that from this point in time, the risk of renewed foam formation is significantly reduced. Thus, from this point in time, the control unit 119 deactivates the fan 137, as can be seen from the illustration (e) of the Fig. 3 can be removed. Alternatively, the controller 119 can deactivate the fan 137 again after a predetermined period of time.

[0104] Fig. 4 shows a schematic representation of a method for reducing foam in a laundry care appliance according to one embodiment.

[0105] The method 200 comprises the method step of activating the ventilation element 131 to supply an air flow to the tub 105 by the controller 119 when the state detected by the state detection element 129 is an exceeding of a fill level threshold value 147, an exceeding of a predetermined minimum speed and / or a detection of foam, and in particular when the drum drive rotates the laundry drum 107 and when the fill level of washing liquid in the tub 105 detected by the fill level detection element 129 is above a fill level threshold value 147, wherein the fill level threshold value 147 corresponds to the fill level which is necessary for the rotating laundry drum 107 to immerse itself in the washing liquid in order to reduce foam present in the tub 105.

[0106] All features explained and shown in connection with individual embodiments of the invention can be provided in different combinations in the subject matter according to the invention in order to simultaneously realize their advantageous effects.

[0107] The scope of the present invention is given by the claims and is not limited by the features explained in the description or shown in the figures. Bezugszeichenliste

[0108] 100 Laundry care appliance 101 Dispensing tray 102 Appliance housing 103 Appliance door 104 Appliance opening 105 Soil container 106 Control element 107 Laundry drum 109 Drum drive 111 Drain opening 113 Feed element 115 Circulation line 117 Pump 118-1 Fresh water supply device 118-2 Fresh water line 119 Control system 121 First control connection 123 Second control connection 125 Third control connection 127 Fourth control connection 129 Level detection element 131 Ventilation element 133 Ventilation duct 135 Outlet opening 137 Fan 139 Heating element 140-1 First curve 140-2 Second curve 140-3 Third curve 140-4 Fourth curve 140-5 Fifth curve 140-6 Sixth curve 140-7 Seventh curve 140-8 Eighth curve 140-9 Ninth curve 140-10 Tenth curve 140-11 Eleventh curve 140-12 Twelfth curve 141 Outlet line 143 Drain device 144 Ordinate axis(es) 145 Distance between tub and laundry drum 147 Fill level threshold 148 Abscissa axis 149 First feed time period 151 Detection time period 200 Method for reducing foam201Procedure step: Activating the ventilation element

Claims

1. A laundry care appliance (100) comprising a tub (105) for receiving washing liquid, a laundry drum (107) for receiving laundry, wherein the laundry drum (107) is arranged in the tub (105) and is rotatable by a drum drive (109) of the laundry care appliance (100), a fresh water supply device (118-1) which is fluidly connected to the tub (105) by a fresh water line (118-2), wherein the tub (105) has a drain opening (111), a ventilation element (131) which is designed to supply an air flow to the tub (105), a state detection element (129) for detecting a state of the laundry care appliance (100), and a controller (119) which is control-technically connected to the ventilation element (131), the drum drive (109), and the state detection element (129). and which is designed to initiate a process step,if the condition detected by the condition detection element (129) indicates that foam is being produced in the tub (105) and / or in the laundry drum (107) or that foam has been produced, characterized in that the controller (119) is designed, in the method step, to activate the ventilation element (131) to supply an air flow to the tub (105) and / or to the laundry drum (107) when the state detected by the state detection element (129) is an exceeding of a fill level threshold value (147), an exceeding of a predetermined minimum speed and / or a detection of foam, in particular when the laundry has absorbed a predetermined amount of washing liquid, in order to reduce foam present in the tub (105) and / or in the laundry drum (107) and / or to prevent the formation of foam in the tub (105) and / or in the laundry drum (107).

2. Laundry care appliance (100) according to claim 1, a level detection element (129) for detecting a level of washing liquid in the tub (105) and the level detection element (129), characterized in thatthe state detection element is a fill level detection element (129) connected to the controller (119) for detecting a fill level of washing liquid in the tub (105), and in that the controller (119) is designed when the drum drive (109) rotates the laundry drum (107) and when the fill level of washing liquid in the tub (105) detected by the fill level detection element (129) is above a fill level threshold value (147), wherein the fill level threshold value (147) corresponds to the fill level which is necessary for the rotating laundry drum (107) to immerse itself in the washing liquid in order to reduce foam present in the tub (105) and / or in the laundry drum (107) and / or to prevent the formation of foam in the tub (105) and / or in the laundry drum (107).

3. Laundry care appliance (100) according to claim 2, characterized in thatthe controller (119) is designed to activate the ventilation element (131) for supplying an air flow to the tub (105) and / or to the laundry drum (107) when the drum drive (109) rotates the laundry drum (107) at a minimum speed and when the fill level of washing liquid in the tub (105) detected by the fill level detection element is above the fill level threshold value (147), wherein the minimum speed is in particular 50 revolutions per minute.

4. Laundry care appliance (100) according to one of the preceding claims, characterized in that a distance (145) between the lowest area of the tub (105) and the lowest area of the laundry drum (107) corresponds to the fill level threshold value (147).

5. Laundry care appliance (100) according to one of the preceding claims, characterized in thatthe ventilation element (131) has a ventilation duct (133) with an outlet opening (135) which is fluidically connected to the tub (105) or the laundry drum (107), and in that the ventilation element (131) has a fan (137) which is arranged in the ventilation duct (133) and is designed to blow air from the ventilation duct (133) through the outlet opening (135) into the tub (105) and / or the laundry drum (107).

6. Laundry care appliance (100) according to one of the preceding claims, characterized in thatthe ventilation element (131) comprises a heating element (139) for heating the air flow, and in that the controller (119) is designed to activate the heating element (139) and the ventilation element (131) to supply a heated air flow to the tub (105) and / or to the laundry drum when the state detected by the state detection element (129) is an exceeding of a fill level threshold value (147), an exceeding of a predetermined minimum speed and / or a detection of foam.

7. Laundry care appliance (100) according to one of the preceding claims, characterized in thatthe laundry care appliance (100) has a pumping device (143) which is fluidically connected to the tub (105), in particular to the drain opening (111), and which is control-wise connected to the controller (119), wherein the controller (119) is designed to activate the pumping device (143) to pump washing liquid out of the tub (105) when the state detected by the state detection element (129) is an exceeding of a fill level threshold value (147), an exceeding of a predetermined minimum speed and / or a detection of foam, wherein the controller (119) is designed in particular to heat the laundry after the washing liquid has been pumped out of the tub (105) by circulating hot air which is provided by the ventilation element (131) comprising a heating element (139).

8. Laundry care appliance (100) according to one of claims 2 to 7, characterized in thatthe fill level detection element (129) is designed as a pressure detection element for detecting a pressure of washing liquid in the tub (105).

9. Laundry care appliance (100) according to one of claims 2 to 8, characterized in that the fill level detection element (129), in particular pressure detection element, comprises a riser pipe arranged in sections in the lye container (105), wherein a pressure sensor for detecting a pressure in the riser pipe is arranged at an end of the riser pipe facing away from the lye container (105) in order to detect the pressure in the lye container (105).

10. Laundry care appliance (100) according to claim 9, characterized in that the riser pipe is designed as a siphon which comprises a curved section which can be filled with washing liquid, and which comprises a vertically extending riser pipe section which can be filled with air and in which the pressure sensor is arranged.

11. Laundry care appliance (100) according to claim 9 or 10, characterized in that the riser pipe has a riser pipe opening at an end facing the suds container (105), which is fluidically connected to the interior of the suds container (105) in order to enable washing liquid and / or foam to penetrate from the interior of the suds container (105) into the riser pipe, wherein the riser pipe is mounted in the suds container (105) in particular in such a way that during the detection time period (151) the liquid level of washing liquid in the suds container (105) is arranged below the riser pipe opening.

12. Laundry care appliance (100) according to one of the preceding claims, characterized in thatthe controller (119) is designed to deactivate the ventilation element (131) again after a predetermined period of time, or that the controller (119) is designed to deactivate the ventilation element (131) again when the drum drive (109) rotates the laundry drum at a speed which is less than or equal to a maximum speed.

13. Laundry care appliance (100) according to one of the preceding claims, characterized in that the condition detection element (129) is a foam detection device for detecting foam, which is control-technically connected to the controller (119), wherein the controller (119) is designed to activate the ventilation element (131) for supplying an air flow to the tub (105) when the drum drive (109) rotates the laundry drum (107) when the foam detection device detects foam.

14. Laundry care appliance (100) according to claim 13, characterized in thatthe tub (105) has a feed element (113) which is fluidically connected to the drain opening (111) by a pumping line (115), and the laundry care appliance comprises a pump (117) which is designed to pump washing liquid out of the tub (105) through the drain opening (111) during a pumping process and to pump the pumped-out washing liquid through the pumping line (115) and through the feed element (113) back into the tub (105), that the foam detection device comprises a power detection element (131) for detecting an electrical power parameter of the pump (117), wherein the controller (119) is designed to activate the pump (117) during a detection time period (151) during the pumping process, and that the controller (119) is designed to detect the presence of foam in the tub (105) determine,if during the detection period (151) the electrical power parameter of the pump (117) detected by the power detection element (131) is less than a power parameter threshold value, and if during the detection period (151) the state detected by the state detection element (129), in particular the fill level in the tub (105) detected by the fill level detection element (129), is greater than a fill level threshold value (147).

15. Method (200) for reducing foam in a laundry care appliance (100), wherein the laundry care appliance (100) has a tub (105) for receiving washing liquid, a laundry drum (107) for receiving laundry, wherein the laundry drum (107) is arranged in the tub (105) and is rotatable by a drum drive (109) of the laundry care appliance (100), a fresh water supply device (118-1) which is fluidly connected to the tub (105) by a fresh water line (118-2), which has a drain opening (111), a ventilation element (131) which is designed to supply an air flow to the tub (105), a state detection element (129) for detecting a state of the laundry care appliance (100) and a controller (119) which is control-technically connected to the pump (117), the ventilation element (131), the drum drive (109) and the condition detection element (129), wherein a method step is initiated,if the condition detected by the condition detection element (129) indicates that foam is being produced in the tub (105) and / or in the laundry drum (107) or that foam has been produced, characterized in thatthe method step comprises: activating (201) the ventilation element (131) to supply an air flow to the tub (105) and / or to the laundry drum (107) by the controller (119) when the drum drive (109) rotates the laundry drum (107), and when the state detected by the state detection element (129) is an exceeding of a fill level threshold value (147), an exceeding of a predetermined minimum speed and / or a detection of foam, in particular when the laundry has absorbed a predetermined amount of washing liquid, in order to reduce foam present in the tub (105) and / or in the laundry drum (107) and / or to prevent the formation of foam in the tub (105) and / or in the laundry drum (107).

Images