Laundry care appliance with a control device

Abstract

A laundry care appliance 100 comprising a tub 105 for holding washing liquid, a washing drum 107 for holding laundry 129, wherein the washing drum 107 is arranged in the tub 105, the tub 105 having a drain opening 111 and a feed element 113 which are fluidly connected by a transfer line 115, a pump 117 which is designed to pump washing liquid out of the tub 105 through the drain opening 111 during a transfer process, and to pump the pumped washing liquid back into the tub 105 through the transfer line 115 and through the feed element 113, a power sensing element 131 for sensing an electrical power parameter of the pump 117, a water level sensing element 129 for sensing a water level in the tub 105 and a control unit 119, which is controlled in conjunction with pump 117,is connected to the power measurement element 131 and the water level measurement element 129.

Description

[0001] The present invention relates to a laundry care device with a control unit.

[0002] In a conventional laundry washing machine, high drum speeds and / or an overdose of laundry detergent can sometimes lead to excessive foaming in the machine's tub. This excessive foaming can cause the foam to overflow from the tub into the detergent dispenser, potentially soiling the area around the machine. Furthermore, excessive foaming can negatively impact the washing results of a cycle.

[0003] Foam detection strategies known from the prior art in laundry care appliances often aim to detect foam formation late in the laundry care process by observing washing parameters over a longer period. Foam formation that occurs very rapidly during a laundry care process is often not detected by these prior art strategies.

[0004] From EP 2 781 640 A1, a washing machine is known which comprises a washing drum arranged in a tub, a transfer line which fluidically connects a drain opening of the tub to a feed element of the tub, a transfer pump which is configured to circulate washing liquid through the transfer line, a control unit for controlling at least one wash cycle and one rinse cycle, a power sensing element for detecting the power consumption of the transfer pump, and a water level sensing element. The control unit of the washing machine is configured to deactivate the transfer pump when a predetermined change in the detected power consumption of the transfer pump is detected.

[0005] German patent DE 10 2020 213 390 A1 discloses a laundry care machine and a method for determining foam when treating laundry items with a liquid in the laundry care machine. The laundry care machine comprises sensors that continuously record operating data and a control system connected to the sensors, comprising a virtual sensor to which the recorded operating data is fed and which determines a measure of the amount of foam present from the operating data.

[0006] From FR 3079849 A1 a washing machine with means for detecting anomalies occurring during operation of the washing machine is known.

[0007] The object of the invention is to provide a laundry care device in which the presence of foam in a lye container of the laundry care device can be determined in a timely manner during a laundry care process.

[0008] This problem is solved by the items with the features according to the independent claims. Advantageous embodiments are the subject of the dependent claims, the description, and the drawings.

[0009] According to a first aspect, the problem according to the invention is solved by a laundry care device comprising a tub for holding washing liquid, a washing drum for holding laundry, wherein the washing drum is arranged in the tub, wherein the tub has a drain opening and a feed element which are fluidly connected by a transfer line, a pump which is designed to pump washing liquid out of the tub through the drain opening during a transfer process, and to pump the pumped washing liquid back into the tub through the transfer line and the feed element, a power sensing element for detecting an electrical power parameter of the pump, a water level sensing element for detecting a water level in the tub, and a control unit which is control-technically connected to the pump,the power sensing element and the water level sensing element, wherein the controller is configured to activate the pump during the pumping process during a sensing period, and wherein the controller is configured to determine the presence of foam in the lye tank if, during the sensing period, the electrical power parameter of the pump detected by the power sensing element is less than a power parameter threshold, and if, during the sensing period, the water level in the lye tank detected by the water level sensing element is greater than a water level threshold.

[0010] In particular, the water level sensing element is configured as a pressure sensing element for detecting pressure in the alkaline tank, and the control is configured to determine the presence of foam in the alkaline tank when, during the detection period, the electrical power parameter of the pump detected by the power sensing element is less than a power parameter threshold, and when, during the detection period, the pressure in the alkaline tank detected by the pressure sensing element is greater than a pressure threshold.

[0011] This achieves the technical advantage that, during the recording period, the presence of foam in the laundry care appliance can be reliably and promptly determined by recording and evaluating only two parameters: the electrical power parameter of the pump and the water level, especially pressure, in the washing container.

[0012] The water level, and in particular the pressure, detected by the water level sensor, especially the pressure sensor, in the washing container rises with an increasing amount of washing liquid in the container. However, the water level, and in particular the pressure, detected by the water level sensor, and in particular the pressure sensor, also rises if foam is present in the washing container.

[0013] The control system cannot distinguish, solely from the fact that the water level threshold, in particular the pressure threshold, is exceeded by the water level, in particular the pressure, detected by the water level sensor in the alkaline container, whether there is foam formation in the alkaline container or whether there is merely an increase in the fill level of the washing liquid in the alkaline container.

[0014] In order for the control system to determine whether a water level, in particular pressure, detected by the water level sensing element, in particular the pressure sensing element, in the alkaline container is due to the presence of foam in the alkaline container and not to an increase in the fill level of washing liquid in the alkaline container, the control system also takes into account the electrical power parameter of the pump detected by the power sensing element.

[0015] In particular, the electrical power parameter of the pump detected by the power sensing element includes the motor current of the pump.

[0016] If the electrical power parameter, especially the motor current, of the pump increases, the control system can conclude that washing liquid is being pumped by the pump, and therefore there is a high power consumption of the pump.

[0017] If the electrical power parameter of the pump, as measured by the power sensing element, falls below the predetermined power parameter threshold, the pump has a low power consumption, which correlates with the pump running idle, i.e., pumping air.

[0018] If the electrical power parameter of the pump is below the predetermined power parameter threshold, the pump will not pump any washing liquid through the transfer line, and consequently, no washing liquid can be present in the washing tank. However, if, at the same time, the water level, and in particular the pressure, detected by the water level sensor, and in particular the pressure sensor, in the washing tank is above the water level threshold, and in particular the pressure threshold, then the detected water level, and in particular the pressure, can only be attributed to the presence of foam in the washing tank.

[0019] This enables effective foam detection in the washing machine container, which can very quickly detect foam formation, so that appropriate countermeasures can be initiated promptly by the control of the washing machine to reduce foam formation.

[0020] A laundry care appliance is understood to be a device used for laundry care, such as a washing machine or a tumble dryer, especially a tumble dryer that has a washing and drying function. Specifically, such a laundry care appliance is understood to be a household laundry care appliance. That is, a laundry care appliance used in the course of household management and with which laundry in typical household quantities is treated.

[0021] In an advantageous embodiment, the control system is configured to determine the presence of foam in the lye container if, during the detection period, the electrical power parameter of the pump detected by the power sensing element is lower than the power parameter threshold for a minimum period of time, in particular for a minimum period of at least 5 seconds.

[0022] This achieves the technical advantage that recording the electrical power parameter of the pump for a minimum period of time ensures that an idle operation of the pump is reliably detected for foam detection, and thus a short-term fluctuation of the electrical power parameter does not lead to a false positive result.

[0023] In an advantageous embodiment, the electrical power parameter of the pump detected by the power sensing element includes a motor current of the pump.

[0024] This achieves the technical advantage that, by evaluating the motor current of the pump, the control system can effectively distinguish whether the pump is conveying washing liquid or merely conveying air during idle operation.

[0025] In an advantageous embodiment, the control system is configured to determine the absence of foam in the alkaline container if, during the detection period, the electrical power parameter of the pump detected by the power sensing element is greater than a power parameter threshold value, and / or if, during the detection period, the water level in the alkaline container detected by the water level sensing element is less than a water level threshold value.

[0026] This achieves the technical advantage of effectively preventing foam formation in the laundry appliance. Either criterion alone, or the combination of both, excludes the presence of foam in the washing machine's tub.

[0027] If the measured electrical power parameter of the pump is greater than the power parameter threshold, the pump will pump washing liquid.

[0028] If the water level detected by the water level sensor in the washing container is less than the water level threshold, there is no washing liquid or foam in the washing container.

[0029] In an advantageous embodiment, the laundry care appliance has a fresh water supply device which is fluidically connected to the washing container and control-technically connected to the control system, and the control system is designed to activate the fresh water supply device to supply fresh water to the washing container during a supply period that takes place before the detection period.

[0030] This achieves the technical advantage that only after the addition of fresh water, possibly with appropriate laundry care substance added from the dispenser tray, is there a significant risk of foam formation in the detergent container.

[0031] In an advantageous embodiment, the control system is configured to activate the pump during the feed time period as part of a pumping process.

[0032] This achieves the technical advantage that by pumping the washing liquid supplied during the feed time period, effective wetting of the laundry with washing liquid is ensured.

[0033] In an advantageous embodiment, the control system is configured to activate the pump during a pumping process during a pumping period following the detection period.

[0034] This achieves the technical advantage that effective laundry care is ensured by pumping the washing liquid after the recording period.

[0035] In an advantageous embodiment, the water level sensing element comprises a riser pipe arranged sectionally in the alkaline container, wherein a water level sensor is arranged at an end of the riser pipe facing away from the alkaline container in order to detect the water level in the alkaline container.

[0036] This achieves the technical advantage of enabling effective water level monitoring in the lye container.

[0037] In this case, the riser pipe has, in particular, an end facing the tubing container, into which, for example, when the washing liquid level in the tubing container rises, the washing liquid can enter the riser pipe and compress the column of air above in the riser pipe, so that the water level sensor, which is arranged at the end of the riser pipe facing away from the tubing container, can detect the corresponding compression of the air column as a rise in water level and correlate it with a rise in washing liquid in the tubing container or with foam development in the tubing container.

[0038] In an advantageous embodiment, the riser pipe is designed as a siphon which includes a curved section that can be filled with washing liquid, and which includes a vertically extending riser pipe section that can be filled with air, in which the water level sensor is arranged.

[0039] 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 effective water level measurement.

[0040] In an advantageous embodiment, the riser pipe has a riser pipe opening at an end facing the alkaline container, which is fluidically connected to the interior of the alkaline container to allow washing liquid and / or foam to penetrate from the interior of the alkaline container into the riser pipe, wherein the riser pipe is in particular mounted in the alkaline container such that during the detection period the liquid level of washing liquid in the alkaline container is located below the riser pipe opening.

[0041] This achieves the technical advantage that the riser pipe opening allows washing liquid and / or foam to enter the riser pipe, thus enabling water level measurement. If the washing liquid level is below the riser pipe opening during the detection period, the water level signal detected by the control system during this period is triggered by the ingress of foam into the riser pipe.

[0042] In an advantageous embodiment, the laundry care device has a drum drive for rotating the washing drum, wherein the drum drive is connected to the control system, wherein the control system is particularly designed to activate the drum drive for rotating the washing drum at a constant speed during the detection time period, during the feed time period and / or during the pumping time period.

[0043] This achieves the technical advantage that the rotation of the washing drum ensures effective wetting and thus laundry care of the laundry in the washing drum.

[0044] In an advantageous embodiment, the control system is configured, after determining the presence of foam in the tub during a change phase following the detection phase, to activate the drum drive to rotate the washing drum at a reduced rotational speed in order to reduce the amount of foam present in the tub.

[0045] This achieves the technical advantage that the rotation of the washing drum at the reduced rotation speed ensures that no further foam is created, thus effectively reducing the amount of foam present in the tub.

[0046] In an advantageous embodiment, the control system is configured to activate a fresh water supply device of the laundry care appliance to supply fresh water to the washing container after determining the presence of foam in the washing container during a further change phase following the detection period.

[0047] This achieves the technical advantage that the amount of foam in the lye container can be advantageously reduced by supplying fresh water, especially cold fresh water.

[0048] In an advantageous embodiment, the control system is configured to deactivate a heating device of the laundry care appliance for heating the washing liquid in the washing container after determining the presence of foam in the washing container during a further change phase following the detection phase, and / or the control system is configured to activate a pumping device of the laundry care appliance for pumping washing liquid out of the washing container after determining the presence of foam in the washing container during a further change phase following the detection phase.

[0049] This achieves the technical advantage that reducing the temperature of the washing liquid in the tub counteracts foam formation or leads to a reduction in the amount of foam. By pumping out washing liquid from the tub, any foam already present in the tub can also be effectively pumped out.

[0050] According to a second aspect, the problem is solved by a method for detecting foam in a laundry care appliance, wherein the laundry care appliance has a tub for holding washing liquid, a drum for holding laundry, the drum being arranged in the tub, the tub having a drain opening and a feed element fluidly connected by a transfer line, a pump designed to pump washing liquid out of the tub through the drain opening during a transfer process and to pump the pumped washing liquid back into the tub through the transfer line and the feed element, a power sensing element for detecting an electrical power parameter of the pump, a water level sensing element for detecting a water level in the tub, and a control system which is controllably connected to the pump.the power sensing element and the water level sensing element, wherein the method comprises the following process steps: activating the pump during the pumping process by the controller during a sensing period, and determining the presence of foam in the caustic tank by the controller if, during the sensing period, the electrical power parameter of the pump detected by the power sensing element is less than a power parameter threshold, and if, during the sensing period, the water level in the caustic tank detected by the water level sensing element is greater than a water level threshold.

[0051] This achieves the technical advantage of ensuring effective foam capture.

[0052] The embodiments identified as advantageous for the laundry care device according to the first aspect are also advantageous embodiments for the method according to the second aspect.

[0053] Exemplary embodiments of the invention are shown in the drawings and are described in more detail below.

[0054] They show: Fig. 1 a schematic view of a laundry care device according to one embodiment; Fig. 2 a schematic view of a laundry care device with a control unit according to one embodiment; Fig. 3 a graphical representation of a laundry care process according to a first embodiment; Fig. 4 a graphical representation of a laundry care process according to a second embodiment; Fig. 5 a schematic representation of a water level sensing element in a washing tub of a laundry care device according to one embodiment; and Fig. 6 a schematic representation of a method for caring for laundry in a laundry care device according to one embodiment.

[0055] Fig. 1 Figure 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 includes a dispenser 101 into which detergents or other liquid laundry care substances can be poured. The laundry care appliance 100 has a housing 102 with an opening 104, which can be closed by a door 103 for loading the laundry care appliance 100. The laundry care appliance 100 also has operating elements 106 for operating the laundry care appliance 100.

[0056] Fig. 2 shows a schematic view of a laundry care appliance with a control system according to one embodiment.

[0057] The laundry care appliance 100 has a tub 105 for holding washing liquid and a drum 107 for holding laundry. The drum 107 is located inside the tub 105. A drum drive 109 rotates the drum 107. The tub 105 has a drain opening 111. The laundry care appliance 100 has a feed element 113. The drain opening 111 is fluidically connected to the feed element 113 by a transfer line 115, and a pump 117 is located in the transfer line 115 to pump washing liquid through it.

[0058] The pump 117 can pump washing fluid through the drain opening 111 from the tub 105 during a cycle. Fig. 2 During the pumping process (not shown), the washing liquid is pumped into the pumping line 115 and fed back through the pumping line 115 and the feed element 113 to the tub 105 and the drum 107. This allows the washing liquid to be effectively pumped through the pumping line 115 during a laundry care process and fed back to the laundry in the drum 107.

[0059] In particular, the laundry care appliance 100 includes a fresh water supply unit 118-1, which has a Fig. 2 detergent dispenser 101 of the laundry care appliance 100 (not shown) and / or one in Fig. 2 The fresh water connection of the laundry care appliance 100, which is not shown, supplies fresh water to the washing container 105, or to the laundry held in the washing drum 107, via a fresh water line 118-2.

[0060] The laundry care appliance 100 further comprises a control unit 119, which is connected to the pump 117 by a first control connection 121, which is connected to the drum drive 109 for rotating the washing drum 107 by a second control connection 123, and which is connected to the fresh water supply device 118-1 for supplying washing liquid to the washing drum 107 by a third control connection 125.

[0061] The control unit 119 is further connected via a fourth control connection 127 to a water level sensing element 129 for detecting a water level in the alkaline container 105. The water level sensing element 129 described in the exemplary embodiments for detecting a water level in the alkaline container 105 is here designed as a pressure sensing element 129 for detecting a pressure in the alkaline container 105.

[0062] The control unit 119 is also equipped with a Fig. 2 The power measurement element 131, shown only schematically, is connected to the pump 117 for recording an electrical power parameter, in particular a motor current.

[0063] The laundry care device 100 also includes an outlet line 133, which is fluidically connected to the transfer pump line 115. A Fig. 2 The pumping device 135, shown only schematically, is designed during a process in Fig. 2 The pumping process (not shown) involves pumping the washing liquid out of the washing container 105 through the drain opening 111, through the transfer line 115 and through the outlet line 133 from the laundry care appliance 100.

[0064] Fig. 3 shows a graphical representation of a laundry care process according to a first embodiment.

[0065] The one in Fig. 3 The first curve 140-1, second curve 140-2, third curve 140-3, and fourth curve 140-4 shown along the ordinate axis 137, in figure (a) the rotational speed of a washing drum 107 of the laundry appliance 100 in revolutions per minute, in figure (b) the quantity of fresh water supplied to the washing tub 105 by a fresh water supply device 118-1 of the laundry appliance 100 in liters, in figure (c) the water level or pressure in the washing tub 105 detected by a water level sensor 129 or by the pressure sensor 129, respectively, in Pascals, and in figure (d) the motor current of the pump 117 detected by a power sensor 131, each as a function of time, which is shown in figures (a), (b), (c) and (d) along the abscissa axis 139.

[0066] In the Fig. 3 The depicted laundry care process encompasses a time period of a laundry care process shown along the abscissa axis 139 in all representations (a), (b), (c), and (d), which extends from approximately second 490 to approximately second 570 of the laundry care process.

[0067] The in Fig. 3 The laundry care process shown begins with the feed time section 141 during which the control unit 119 is configured to activate a fresh water supply device 118-1 of the laundry care appliance 100 to supply fresh water to the tub 105, as can be seen from illustration (b).

[0068] Furthermore, it can be seen from illustration (c) that the water level in the alkaline container 105, as detected by the water level detection element 129, also rises during the supply time period 141 due to the fresh water supplied to the alkaline container 105.

[0069] The supply time section 141 is followed by the detection time section 143, whereby at the beginning of the detection time section 143, the controller 119 activates the pump 117 as part of the transfer process in order to pump washing liquid through a transfer line 115 of the laundry care appliance 100. The activation of the pump 117 by the controller 119 at the beginning of the detection time section 143 leads to a complete transfer of the fresh water supplied to the washing tank 105, as can be seen from the significant increase in the detected motor current of the pump 117 in diagram (d). Fig. 3 can be extracted.

[0070] According to a representation (d) of the Fig. 3 Despite the observed fluctuation in the measured motor current of pump 117, the motor current of pump 117 stabilizes at a constant level during the remainder of the measurement period 143. This level is below a power parameter threshold value 145, indicating that pump 117 is running idle. During idle operation, pump 117 does not pump washing liquid, but rather air, which is characterized by an extremely low motor current. Therefore, the idle operation of pump 117 indicates that the washing liquid has been completely absorbed by the laundry in the washing drum 107.

[0071] Thus, the idling operation of pump 117 recorded during the recording period 143 excludes the possibility that free, i.e. unbound, washing liquid is still present in the lye container 105.

[0072] As shown in illustration (c) of the Fig. 3 However, even if the water level can be removed, the water level sensing element 129 also detects a water level in the washing tank 105 during the detection period 143 and during the pump 117's idle operation, which is above a water level threshold 144 (in this case zero). The water level threshold 144 can also be set greater than zero, for example, to compensate for tolerances. The water level threshold 144 is preferably set such that a detected water level that is less than or equal to the water level threshold 144 indicates that no washing liquid is present in the washing tank 105.

[0073] Since the presence of washing liquid in the detergent tank 105 is excluded by the detected idling operation of the pump 117, the water level in the detergent tank 105 detected during the detection period 143 is based in this case on the presence of foam in the detergent tank 105, which results in the correspondingly detected water level value in the detergent tank 105, so that the control unit 119 can detect the presence of foam in the detergent tank 105 immediately and promptly after the activation of the pump 117.

[0074] The recording time period 143 is followed by a pumping time period 147 during which the pump 117 continues to operate in idle mode.

[0075] As can be seen from illustrations (a), (b), (c), and (d) of the Fig. 3 As can be seen, the control unit 119 activates the drum drive during the feed time section 141, during the detection time section 143 and during the pumping time section 147 in order to rotate the washing drum 107 at a constant speed.

[0076] The generation of the water level value recorded during the recording period 143 is based on the fact that the water level sensing element 129 in particular comprises a riser pipe which is designed as a siphon, which includes a curved section that can be filled with washing liquid, and which includes a vertically extending riser pipe section that can be filled with air.

[0077] For example, the rotation of the washing drum 107, when using a correspondingly overdosed amount of laundry care substance, generates a corresponding amount of foam within the tub 105. This foam then penetrates the riser pipe of the water level sensing element 129, creating a corresponding water level reading which decreases only slowly during the pumping time period 147, as shown in illustration (c) of the Fig. 3 can be removed. Any foam generated in the alkaline container 105 can therefore only drain away slowly after the liquid level in the alkaline container 105 has dropped.

[0078] The present invention thus enables very rapid detection of the occurrence of foam in the lye container 105 immediately after activation of the pump 117, so that an unacceptably large amount of foam can be prevented in a timely manner.

[0079] A corresponding reduction of foam following foam capture can be ensured, for example, by rotating the washing drum 107 at a reduced rotation speed in order to reduce the amount of foam present in the tub 105.

[0080] Alternatively or additionally, it is also possible to activate the fresh water supply device 118-1 of the laundry care appliance 100 to supply fresh water to the tub 105, and / or to deactivate a heating device of the laundry care appliance 100 to heat the washing liquid in the tub 105, and / or to activate a pumping device 135 of the laundry care appliance 100 to pump washing liquid out of the tub 105 in order to initiate effective foam control measures.

[0081] Fig. 4 shows a graphical representation of a laundry care process according to a second embodiment.

[0082] The subject of the in Fig. 4 The embodiment shown differs from the one in Fig. 3 the embodiment shown, in that in the Fig. 4 In the embodiment shown, no foam is present in the lye container 105.

[0083] This can be detected by the control unit 119 in such a way that during the detection period 143 the water level value shown in the illustration (c) does not exceed the water level threshold value 144 during the corresponding idle operation of the pump 117 shown in the illustration (d) or only to an extremely small extent.

[0084] Fig. 5 Figure 1 shows a schematic representation of a water level detection element in a detergent container of a laundry care appliance according to one embodiment.

[0085] In the Fig. 5 The figure only schematically shows a section of a tub 105 of a laundry care appliance 100 with a liquid level 149 of the washing liquid.

[0086] The water level sensing element 129 comprises a Fig. 5 schematically represented riser pipe 151.

[0087] The in Fig. 5 The riser pipe 151, shown only schematically and designed as a siphon, has a riser pipe opening 155 at one end 153 facing the alkali container 105, which is fluidically connected to the alkali container 105.

[0088] As the liquid level 149 of washing liquid rises, the washing liquid penetrates the interior of the riser tube 151 through the riser tube opening 155 and compresses air which is contained within a Fig. 5 not shown, vertical section of the riser pipe 151, so that a Fig. 5 The water level sensor of the riser pipe 151 (not shown) can detect a rise in water level.

[0089] In the Fig. 5 In the measurement situation shown during the recording period 143, the liquid level 149 of the washing liquid is significantly below the riser pipe opening 155, so that a rise in the water level in the riser pipe 151 detected during the recording period 143 is not caused by the penetration of washing liquid into the riser pipe 151, but results from foam being accelerated by the rotating washing drum 107 and penetrating through the riser pipe opening 155.

[0090] Thus, the water level detection element 129, which includes the schematically depicted riser pipe 151, can detect not only the fill level of washing liquid in the alkaline container 105, but also the presence of foam in the alkaline container 105.

[0091] Fig. 6 shows a schematic representation of a method for capturing foam in a laundry care appliance according to one embodiment.

[0092] The procedure 200 includes as its first step the activation 201 of the pump 117 during the pumping process by the control unit 119 during a detection period 143.

[0093] The procedure 200 comprises, as a second procedure step, determining 203 the presence of foam in the caustic tank 105 by the controller 119 if, during the detection period 143, the electrical power parameter of the pump 117 detected by the power detection element 131 is less than a power parameter threshold value 145, and if, during the detection period 143, the water level in the caustic tank 105 detected by the water level detection element 129 is greater than a water level threshold value 144.

[0094] All features explained and shown in connection with individual embodiments of the invention can be provided in different combinations in the object according to the invention in order to simultaneously realize their advantageous effects.

[0095] The scope of protection of the present invention is defined by the claims and is not limited by the features explained in the description or shown in the figures. Bezugszeichenliste

[0096] 100 Laundry appliance 101 Detergent dispenser 102 Appliance housing 103 Appliance door 104 Appliance opening 105 Tub 106 Control panel 107 Washing drum 109 Drum drive 111 Drain opening 113 Feed element 115 Pump line 117 Pump 118-1 Fresh water supply device 118-2 Fresh water line 119 Control unit 121 First control connection 123 Second control connection 125 Third control connection 127 Fourth control connection 129 Water level sensor 131 Power sensor 133 Outlet line 135 Drain pump 137 Ordinary axis 139 Abscissa axis 140-1 First curve 140-2 Second curve 140-3 Third curve 140-4 Fourth curve 141 Feed time section 143 Detection time section 144 Water level threshold 145 Performance parameter threshold 147 Pumping time section 149 Liquid level 151 Riser pipe 153 End of riser pipe facing the tub 155 Riser pipe opening 200 Method for detecting foam in a laundry care appliance 201 First process step: Activation of the pump by the controller 203 SecondProcess step: Determining the presence of foam in the lye container by means of the control system.

Claims

1. Laundry care appliance (100) with an outer tub (105) for receiving washing liquid, a laundry drum (107) for receiving laundry (129), wherein the laundry drum (107) is arranged in the outer tub (105), wherein the outer tub (105) has a drain opening (111) and a supply element (113), which are fluidically connected by way of a recirculation line (115), a pump (117) which, within the scope of a recirculation process, is embodied to discharge washing liquid out of the outer tub (105) through the drain opening (111), and to pump the discharged washing liquid through the recirculation line (115) and through the supply element (113) back into the outer tub (105), a performance recording element (131) for recording an electrical performance parameter of the pump (117), a water level recording element (129) for recording a water level in the outer tub (105) and a controller (119), which is connected by way of control technology to the pump (117), the performance recording element (131) and the water level recording element (129), wherein the controller (119) is embodied to activate the pump (117) within the scope of the recirculation process during a recording time segment (143), and that the controller (119) is embodied to detect the electrical performance parameter of the pump (117) during the recording time segment (143) by way of the performance recording element (131) and during the recording time segment (143) to detect the water level in the outer tub (105) by way of the water level recording element (129), characterised in that the controller (119) is embodied to determine the presence of foam in the outer tub (105), when, during the recording time segment (143), the electrical performance parameter of the pump (117) detected by the performance recording element (131) is less than a performance parameter threshold value (145), and when, during the recording time segment (143), the water level in the outer tub (105) recorded by the water level recording element (129) is greater than a water level threshold value (144).

2. Laundry care appliance (100) according to claim 1, characterised in that the controller (119) is embodied to determine the presence of foam in the outer tub (105), when, during the recording time segment (143), the electrical performance parameter of the pump (117) recorded by way of the performance recording element (131) is less than the performance parameter threshold value (145) for a minimum duration, in particular for a minimum duration of at least 5 seconds.

3. Laundry care appliance (100) according to claim 1 or 2, characterised in that the electrical performance parameter of the pump (117) recorded by the performance recording element (131) comprises a motor current of the pump (117).

4. Laundry care appliance (100) according to one of the preceding claims, characterised in that the controller (119) is embodied to determine the absence of foam in the outer tub (105), when, during the recording time segment (143), the electrical performance parameter of the pump (117) recorded by the performance recording element (131) is greater than a performance parameter threshold value (145), and / or when, during the recording time segment (143), the water level in the outer tub (105) recorded by the water level recording element (129) is less than a water level threshold value (144).

5. Laundry care appliance (100) according to one of the preceding claims, characterised in that the laundry care appliance (100) has a fresh water supply facility (118-1), which is fluidically connected to the outer tub (105) and via control technology to the controller (119), that the controller (119) is embodied, during a supply time segment (141) which takes place before the recording time segment (143), to activate the fresh water supply facility (118-1) in order to supply fresh water in the outer tub (105).

6. Laundry care appliance (100) according to claim 5, characterised in that the controller (119) is embodied, during the supply time segment (141), to activate the pump (117) within the scope of a recirculation process.

7. Laundry care appliance (100) according to one of the preceding claims, characterised in that the controller (119) is embodied, during a recirculation time segment (147) which follows on from the recording time segment (143), to activate the pump (117) within the scope of a recirculation process.

8. Laundry care appliance (100) according to one of the preceding claims, characterised in that the water level recording element (129) comprises a riser pipe (151) arranged in sections in the outer tub (105), wherein a water level sensor for recording a water level in the riser pipe (151) is arranged on an end of the riser pipe (151) which faces away from the outer tub (105), in order to record the water level in the outer tub (105).

9. Laundry care appliance (100) according to claim 8, characterised in that the riser pipe (151) is embodied as a siphon, which comprises a curved segment which can be filled with washing liquid, and which comprises a riser pipe segment, which extends vertically and can be filled with air, and in which the water level sensor is arranged.

10. Laundry care appliance (100) according to claim 8 or 9, characterised in that the riser pipe (151) has a riser pipe opening (155) on an end (153) facing the outer tub (105), which is fluidically connected to the interior space of the outer tub (105), in order to enable washing liquid and / or foam to penetrate out of the interior space of the outer tub (105) into the riser pipe (151), wherein the riser pipe (151) is assembled in the outer tub (151) in particular such that during the recording time segment (141) the liquid level (149) of washing liquid in the outer tub (105) is arranged below the riser pipe opening (155).

11. Laundry care appliance (100) according to one of the preceding claims, characterised in that the laundry care appliance (100) has a drum drive (109) for rotating the laundry drum (107), wherein the drum drive (109) is connected via control technology to the controller (119), wherein the controller (119) is embodied in particular, during the recording time segment (143), during the supply time segment (141) and / or during the recirculation time segment (147), to activate the drum drive (109) in order to rotate the laundry drum (107) at a constant speed.

12. Laundry care appliance (100) according to claim 11, characterised in that the controller (119) is embodied, after determining the presence of foam in the outer tub (105) during a change segment which follows on from the recording time segment (143), to activate the drum drive (109) in order to rotate the laundry drum (107) at a reduced rotational speed, in order to reduce the quantity of foam present in the outer tub (105).

13. Laundry care appliance (100) according to one of the preceding claims, characterised in that the controller (119) is embodied, after determining the presence of foam in the outer tub (105) during a further change segment which follows on from the recording time segment (143), to activate a fresh water supply facility (118-1) of the laundry care appliance (100) in order to supply fresh water in the outer tub (105).

14. Laundry care appliance (100) according to one of the preceding claims, characterised in that the controller (119) is embodied, after determining the presence of foam in the outer tub (105) during a further change segment which follows on from the recording time segment (143), to deactivate a heating facility of the laundry care appliance (100) in order to heat up the washing liquid in the outer tub (105), and / or that the controller (119) is embodied, after determining the presence of foam in the outer tub (105) during a further change segment which follows on from the recording time segment (143), to activate a discharge facility (135) of the laundry care appliance (100) in order to discharge washing liquid out of the outer tub (105).

15. Method (200) for recording foam in a laundry care appliance (100), wherein the laundry care appliance (100) has an outer tub (105) for receiving washing liquid, a laundry drum (107) for receiving laundry (129), wherein the laundry drum (107) is arranged in the outer tub (105), wherein the outer tub (105) has an outlet opening (111) and a supply element (113), which are fluidically connected by way of a recirculation line (115), a pump (117), which is embodied, within the scope of a recirculation process, to discharge washing liquid out of the outer tub (105) through the drain opening (111), and to pump the discharged washing liquid through the recirculation line (115) and through the supply element (113) back into the outer tub (105), a performance recording element (131) for recording an electrical performance parameter of the pump (117), a water level recording element (129) for recording a water level in the outer tub (105) and a controller (119), which is connected via control technology to the pump (117), the performance recording element (131) and the water level recording element (129), wherein the method (200) comprises the following method steps: activating (201) the pump (117) within the scope of the recirculation process by way of the controller (119) during a recording time segment (143), in which the electrical performance parameter of the pump (117) is recorded by way of the performance recording element (131) and the water level in the outer tub (105) is recorded by way of the water level recording element (129), characterised by the method steps: determining (203) the presence of foam in the outer tub (105) by way of the controller (119), when, during the recording time segment (143), the electrical performance parameter of the pump (117) recorded by the performance recording element (131) is less than a performance parameter threshold value (145), and when, during the recording time segment (143), the water level in the outer tub (105) recorded by way of the water level recording element (129) is greater than a water level threshold value (144).

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