Laundry care appliance with control device

Abstract

The present invention relates to a laundry care appliance comprising: a lye container; a turbidity sensor for detecting turbidity of washing liquid in the lye container, the turbidity sensor being arranged in a turbidity detection area located in the lye container or in a pipeline fluidically connected to the lye container; a fresh water supply element fluidically connected to the turbidity detection area and supplying fresh water to the turbidity detection area; a discharge pipeline connecting the turbidity detection area to a discharge outlet; a pump arranged in the discharge pipeline and pumping washing liquid from the turbidity detection area through the discharge pipeline out of the laundry care appliance; and a control device control-connected to the fresh water supply element, the turbidity sensor, and the pump. The control device activates the pump to pump washing liquid from the turbidity detection area to the discharge pipeline, activates the fresh water supply element to supply fresh water to the turbidity detection area, and after supplying fresh water to the turbidity detection area, stores the turbidity of the washing liquid in the turbidity detection area detected by the turbidity sensor as a zero value to calibrate the turbidity sensor.

Description

Technical Field

[0001] The invention relates to a laundry care appliance with a control device. Background Art

[0002] In order to ensure particularly optimized laundry care in conventional laundry care appliances, a turbidity sensor is often used, which is configured to detect the turbidity of the washing liquid. By means of the turbidity of the washing liquid detected by the turbidity sensor, the progress of the laundry care program can be advantageously monitored by the laundry care appliance. In particular, during or after the washing process or rinsing process of the laundry care program, it is advantageous to detect when the turbidity of the washing liquid reaches an upper limit value or a lower limit value. For example, the washing process can be terminated when the washing lye reaches a high turbidity, or the rinsing process can be terminated when the turbidity is low enough. In particular, alternatively or additionally, the concentration of the laundry care substance in the washing liquid can be monitored by means of a turbidity sensor. However, it is usually troublesome to calibrate the turbidity sensor used accordingly in conventional laundry care appliances. Here, calibration is understood to mean setting the zero point (or reference value) of the sensor.

[0003] DE 10 2007 031 480 A1 discloses a sensor device and a method for detecting the turbidity of a rinse liquid.

[0004] A method for operating a turbidity sensor is disclosed in DE 10 2009 002 153 B1. Summary of the Invention

[0005] The object underlying the present invention is to provide a laundry care appliance having a turbidity sensor and a method for calibrating a turbidity sensor of the laundry care appliance, which turbidity sensor can be operated particularly advantageously.

[0006] This object is achieved by the subject matter having the features according to the independent claims. Advantageous embodiments are the subject matter of the dependent claims, the description and the drawings.

[0007] According to a first aspect, the object of the present invention is achieved by a laundry care appliance, which comprises: a lye container for receiving washing liquid; a turbidity sensor for detecting the turbidity of the washing liquid received in the lye container, wherein the turbidity sensor is arranged in a turbidity detection area, the turbidity detection area is located in the lye container or in a pipeline connected to the lye container in terms of fluid technology; a fresh water supply element, the fresh water supply element is connected to the turbidity detection area (in particular to the lye container) in terms of fluid technology and is configured to: supply fresh water to the turbidity detection area (in particular to the lye container); a discharge line, the discharge line connects the turbidity detection area (in particular to the lye container) to the discharge outlet of the laundry care appliance in terms of fluid technology; a pump, the pump being arranged in the discharge line and being configured to: supply the washing liquid a fresh water supply element, a turbidity sensor, and a pump, wherein the control device is configured to activate the pump in order to pump washing liquid from the turbidity detection area (in particular from the alkali liquid container) into the discharge line; wherein the control device is configured to activate the fresh water supply element in order to supply fresh water to the turbidity detection area (in particular the alkali liquid container); and wherein the control device is configured to, after supplying fresh water to the turbidity detection area (in particular the alkali liquid container), store the turbidity of the washing liquid in the turbidity detection area (in particular in the alkali liquid container) detected by the turbidity sensor as a zero value for the turbidity sensor in order to calibrate the turbidity sensor. Activating the pump, activating the fresh water supply element, and detecting the turbidity as a zero value for the turbidity sensor are understood as a turbidity sensor calibration process.

[0008] The area within the lye container (or a pipeline connected to the lye container) in which at least a portion of the turbidity sensor is arranged is referred to as the turbidity detection area. The turbidity detection area is a spatial region within the lye container or within a pipeline fluidically connected to the lye container that has a sufficient spatial extent to allow the turbidity of the washing liquid in this region to be detected by the turbidity sensor.

[0009] The turbidity sensor is preferably arranged in the lye container. In this arrangement, the turbidity detection area is located inside the lye container. Alternatively, the turbidity sensor can also be arranged in a pipeline that is fluidically connected to the lye container, wherein in this arrangement, the turbidity detection area is located outside the lye container. This pipeline can be designed as a bypass line, a circulation line (through which the washing liquid pumped out of the lye container can be fed back to the lye container), or a liquid chamber. Furthermore, the turbidity sensor can also be arranged in a supply line, a pump, or a discharge line. In other words, the turbidity sensor is arranged so that it can detect the washing liquid (or fresh water) supplied to the lye container (or to the turbidity detection area). To this end, it is sufficient if the turbidity sensor is arranged in a pipeline or container that is connected to the lye container according to the principle of a connecting line.

[0010] This provides the following technical advantages: the fresh water supplied to the alkaline solution container (or to the turbidity detection area) via the fresh water supply element is free of any turbidity, since any washing liquid (or washing water) present in the area of ​​the turbidity sensor is removed by the pump activation, and the supplied fresh water is free of laundry care substances and generally free of contaminants that would cause turbidity in the fresh water. Therefore, during the turbidity sensor calibration process, the absence of turbidity in the fresh water can be stored as a zero value for the turbidity sensor, thereby ensuring effective calibration of the turbidity sensor.

[0011] Therefore, a corresponding calibration process for the turbidity sensor is necessary because, in laundry care appliances, some washing liquid may remain in the appliance after the wash cycle has concluded. In particular, in laundry care appliances that do not have a closure in the lower area of ​​the lye container (the so-called lye container bottom closure), this remaining washing liquid may flow back into the lye container or into a pipeline connected to the lye container. Consequently, this washing liquid may also reach the area of ​​the lye container (or pipeline) where the turbidity sensor is located.

[0012] Typically, the washing liquid from the previous laundry care program that flows back into the lye container contains contaminated washing liquid with a high turbidity, wherein the corresponding high turbidity does not correspond to the turbidity of the fresh water. If fresh water is now supplied to the lye container (or the turbidity detection area) at the start of a new laundry care program, the supplied fresh water mixes with the washing liquid with a high turbidity already present in the lye container (or the turbidity detection area), so that the resulting mixture has a turbidity state that does not correspond to the turbidity of the fresh water.

[0013] For this reason, the determination of a reference value for the turbidity of the washing liquid, which is usually carried out in conventional laundry care appliances at the beginning of a laundry care process, often leads to inaccurate measurements when determining the reference value for the washing liquid due to the mixture of fresh water and washing liquid flowing back from a previous laundry care process present in the lye container.

[0014] For this reason, the laundry care appliance according to the present disclosure performs a turbidity sensor calibration process in order to ensure effective calibration of the turbidity sensor at the beginning of the laundry care process.

[0015] By activating the pump during the turbidity sensor calibration process, the pump arranged in the discharge line generates a pump pressure, thereby pumping the washing liquid remaining in the lye container (or turbidity detection area) from the previous laundry care program out of the lye container (or turbidity detection area), so that the filling level (liquid level) of the washing liquid in the lye container (or turbidity detection area) drops, in particular to below the liquid level detected by the turbidity sensor. The so-called turbidity sensor level is the liquid level at which the washing liquid level is still just below the turbidity sensor or at which the washing liquid has just not reached the turbidity detection area.

[0016] Fresh water is now supplied to the lye container (or turbidity detection area) via the activated fresh water supply element. As the level of the pumped-out contaminated washing liquid in the lye container (or turbidity detection area) decreases, the fresh water fills the lower area of ​​the lye container (or turbidity detection area) with fresh water, so that the level of the supplied fresh water rises above the liquid level detected by the turbidity sensor. This means that the level of the supplied fresh water is above the turbidity sensor level, in particular, above the turbidity detection area.

[0017] Therefore, after fresh water has been supplied to the turbidity detection area, the turbidity of the washing liquid detected by the turbidity sensor corresponds to the turbidity of the fresh water, because the supplied fresh water cannot be contaminated by the contaminated washing liquid pumped out from the previous laundry care program, or such contamination is minimized so that it does not significantly hinder the zero value measurement of the turbidity sensor.

[0018] Therefore, after fresh water has been fed into the turbidity detection region, the turbidity of the washing liquid detected by the turbidity sensor can advantageously be stored as a zero value for this turbidity sensor in order to calibrate the turbidity sensor.

[0019] Preferably, the pump is activated first, and then the fresh water supply element is activated, as this prevents residual wash water from mixing with the supplied fresh water in the turbidity detection area. However, the pump and fresh water supply element can also be activated simultaneously or in the opposite order. The preferred embodiment depends in particular on how quickly the laundry can be removed from the turbidity detection area by the pumping process and how quickly fresh water can be supplied to the turbidity detection area by means of the fresh water supply element. If, for example, the fluid-based arrangement and configuration means that the supply of fresh water to the turbidity detection area lasts longer than the removal of wash liquid from this area, the fresh water supply process can also be activated before the pumping process to shorten the overall duration of the turbidity sensor calibration process.

[0020] When the wash liquor turbidity is detected further in the laundry care program with the aid of a calibrated turbidity sensor, this wash liquor turbidity actually arises during the ongoing laundry care program and not as a result of a deviation (or measurement error) caused by a calibration error.

[0021] Thus, advantageous control of the laundry care program can be ensured depending on the turbidity of the wash liquor detected by means of a calibrated turbidity sensor.

[0022] In particular, the controlled removal of contaminated washing liquid from a previous laundry care process ensures that the pump completely removes any contaminated washing liquid remaining in the lye container (or in the turbidity detection area) from the previous laundry care process. This advantageously ensures that the turbidity sensor calibration process is performed with fresh water.

[0023] In particular, the controlled pumping out of contaminated washing liquid from a preceding laundry care process ensures that contaminated washing liquid is not pumped out of the drain line or is pumped out only in very small quantities, so that only a small amount of fresh water has to be supplied to the lye container during the turbidity sensor calibration process, so that virtually no additional water consumption occurs.

[0024] In particular, contaminated washing liquid remains in the discharge line (in particular remains completely in the discharge line) during the pumping out.

[0025] The turbidity sensor comprises, in particular, an optical transmitter (in particular a light source) arranged in the washing liquid and emitting light, and an optical receiver (in particular an optical detector) arranged in the washing liquid, which receives the light emitted by the optical transmitter and guided via the washing liquid, wherein the electronic analysis device of the turbidity sensor can determine the turbidity of the washing liquid based on a comparison between the light emitted by the optical transmitter and the light received by the optical receiver.

[0026] A laundry care appliance is understood to be an appliance that is used for laundry care, such as a washing machine or a laundry dryer. In particular, such a laundry care appliance is understood to be a household laundry care appliance, i.e. a laundry care appliance that is used within the framework of housework and with which a typical household load of laundry is processed.

[0027] In an advantageous embodiment of the laundry care appliance, the control device is designed to activate the fresh water supply element simultaneously with the pump or with a time offset in order to supply fresh water to the lye container (or the turbidity detection area) simultaneously with the pumping of washing liquid from the lye container (or from the turbidity detection area) or with a time offset in order to supply fresh water to the lye container (or the turbidity detection area) simultaneously with the pumping of washing liquid from the lye container (or from the turbidity detection area).

[0028] This achieves the technical advantage that, when supplying fresh water at a time offset relative to the pumping out of the washing liquid, it can be ensured that while the contaminated washing liquid is being pumped out of the alkaline solution container (or the turbidity detection area), the falling level of the contaminated washing liquid is reduced to a sufficient extent so that no significant mixing of the supplied fresh water and the contaminated washing liquid occurs within the turbidity detection area.

[0029] Alternatively, the pump and the fresh water supply element can be activated simultaneously. Due to the time delay until the fresh water supplied by the fresh water supply element reaches the lower area of ​​the lye container (or the turbidity detection area), this is sufficient to avoid significant mixing of fresh water and contaminated washing liquid, especially when the pump power is high and / or when there is a small amount of contaminated washing liquid in the lye container (or in the turbidity detection area).

[0030] In an advantageous embodiment of the laundry care appliance, the control device is designed to terminate the fresh water supply after the fresh water supply period.

[0031] This achieves the technical advantage that the termination of the fresh water supply after the fresh water supply period ensures that the amount of fresh water supplied is kept low, thereby avoiding excessive water consumption. In particular, the fresh water supply period is selected to be so short that it corresponds to the time period required for the fresh water supplied by the fresh water supply element to reach the pump.

[0032] In an advantageous embodiment of the laundry care appliance, the laundry care appliance has a liquid level sensor, which is arranged in the lye container (in particular in the lower area of ​​the lye container) and is configured to: detect the liquid level of the washing liquid in the lye container (or in the turbidity detection area), wherein the control device is configured to: terminate the supply of fresh water when the liquid level of the washing liquid detected by the liquid level sensor exceeds a liquid level threshold.

[0033] This achieves the following technical advantage: the filling level sensor ensures that the fresh water supply is terminated when the filling level of the fresh water supplied to the alkali liquid container (or in the turbidity detection area) exceeds a filling level threshold value (that is, it is large enough so that the turbidity sensor arranged in the turbidity detection area is wetted by the supplied fresh water to ensure effective calibration).

[0034] In an advantageous embodiment of the laundry care appliance, the laundry care appliance has a power detection element, which is configured to detect an electrical power value of a pump drive of the pump, wherein the control device is configured to deactivate the pump when the electrical power value detected by the power detection element exceeds a power threshold value.

[0035] The electrical power value of the pump drive comprises in particular the electrical power or the supply current of the pump drive.

[0036] This achieves the technical advantage that the fresh water supply is terminated when the supplied fresh water reaches the pump. After the washing liquid is pumped out of the turbidity detection area (especially from the lye container), the delivery flow decreases, and thus the electrical power value also decreases. If the supplied fresh water now reaches the pump and the pump begins to pump the supplied fresh water, the delivery flow increases, and thus the electrical power value of the pump drive increases again. If the electrical power value detected by the power detection element exceeds a power threshold, the control device recognizes that the supplied fresh water has reached the pump and switches it off.

[0037] In an advantageous embodiment of the laundry care appliance, the control device is designed to terminate the fresh water supply simultaneously or at a time offset after the pump has been deactivated.

[0038] This achieves the technical advantage that, depending on the duration and amount of the fresh water supply, the fresh water supply is terminated simultaneously (ie immediately) after the pump is deactivated, or the fresh water supply is terminated after a certain duration.

[0039] In an advantageous embodiment of the laundry care appliance, the control device is designed to terminate the fresh water supply when the electrical power value detected by the power detection element exceeds a power threshold value.

[0040] This achieves the technical advantage that, as a result of the power value exceeding the power threshold value, not only can the pump be deactivated, but the fresh water supply can also advantageously be terminated.

[0041] In an advantageous embodiment of the laundry care appliance, the turbidity sensor is configured to detect the turbidity of the washing liquid in a turbidity detection area, and the control device is configured to calibrate the turbidity sensor when the level of the washing liquid in the turbidity detection area is higher than the level of the turbidity sensor. In particular, the turbidity detection area is arranged in a lower area of ​​the lye container.

[0042] This achieves the technical advantage that the calibration is not performed with the turbidity sensor in a dry state, but rather ensures that the calibration is performed only when a sufficient amount of fresh water has been supplied to the turbidity detection region to ensure wetting of the turbidity sensor.

[0043] In particular, the turbidity sensor itself can detect the degree of dryness, and the control device is configured to prevent calibration of the turbidity sensor when the turbidity sensor is dry. This advantageously utilizes the effect that the values ​​detected by the turbidity sensor in a dry state differ significantly from the values ​​detected in the presence of liquid. Therefore, by evaluating the values ​​detected by the turbidity sensor, it is also possible to determine whether the turbidity sensor is dry.

[0044] In an advantageous embodiment of the laundry care appliance, there is no laundry container seal between the turbidity detection area (in particular the laundry container) and the discharge line, in order to improve the exchange of washing liquid between the laundry container and the discharge line and to accelerate the discharge of washing liquid from the turbidity detection area (or from the laundry container).

[0045] This achieves the technical advantage that, due to the absence of a lye container seal, an effective fluidic connection is ensured between the turbidity detection area and the discharge line. This effective fluidic connection ensures the removal of contaminated washing liquid, thereby enabling effective calibration of the turbidity sensor with fresh water.

[0046] In an advantageous embodiment of the laundry care appliance, the control device is designed to activate the pump during the calibration process of the turbidity sensor in order to pump washing liquid from the laundry container up to a pump-out level in the outlet line.

[0047] This achieves the technical advantage that pumping out the washing liquid up to the outlet level in the outlet line ensures that the washing liquid is not pumped out of the outlet line but rather remains in the outlet line, so that water consumption can be advantageously reduced.

[0048] In an advantageous embodiment of the laundry care appliance, the laundry care appliance comprises a laundry care substance supply element, which is configured to supply laundry care substance to the washing liquid in the alkaline liquid container, and the control device is configured to activate the laundry care substance supply element after calibrating the turbidity sensor in order to supply laundry care substance to the washing liquid in the alkaline liquid container and the turbidity detection area, wherein the control device is configured to detect the concentration of the laundry care substance in the washing liquid based on the turbidity of the washing liquid in the turbidity detection area detected by the calibrated turbidity sensor.

[0049] This provides the following technical advantage: the turbidity of the washing liquid detected by the calibrated turbidity sensor provides the control device with useful information about the concentration of the laundry care substance dissolved in the washing liquid. In particular, the control device can terminate the supply of the laundry care substance during a laundry care program when the turbidity of the washing liquid detected by the calibrated turbidity sensor exceeds a turbidity threshold value.

[0050] In one advantageous embodiment of the laundry care appliance, the control device is configured to execute a laundry care program for the laundry care appliance after calibrating the turbidity sensor. The control device is configured to alter the wash and / or rinse steps of the laundry care program based on the turbidity of the washing liquid in the lye container (or turbidity detection area) detected by the calibrated turbidity sensor. For example, the wash and / or rinse steps may be terminated or their duration may be extended. Furthermore, the control device may take additional measures based on the detected turbidity, such as re-dosing the laundry care substance, switching on the heating device again, switching off the heating device to prevent foaming, or initiating an additional rinse step. Furthermore, the control device may also be configured to execute or repeat the calibration process during the laundry care program (e.g., between the wash and rinse steps).

[0051] This provides the technical advantage that the turbidity of the washing liquid detected by the calibrated turbidity sensor after the washing and / or rinsing step can provide information about the purity of the washing liquid rinsed from the laundry. In particular, the control device can terminate the rinsing step of the laundry care program when the turbidity of the washing liquid detected by the calibrated turbidity sensor falls below a further turbidity threshold.

[0052] According to a second aspect, the object of the invention is achieved by a method for calibrating a turbidity sensor of a laundry care appliance, wherein the laundry care appliance comprises: a lye container for receiving washing liquid; a turbidity sensor for detecting the turbidity of the washing liquid received in the lye container, wherein the turbidity sensor is arranged in a turbidity detection area, which is located in the lye container or in a pipeline that is fluidically connected to the lye container; a fresh water supply element that is fluidically connected to the turbidity detection area (especially to the lye container) and is configured to supply fresh water to the turbidity detection area (especially to the lye container); a discharge line that fluidically connects the turbidity detection area (especially the lye container) to an outlet of the laundry care appliance; a pump that is arranged in the discharge line and a control device connected to the fresh water supply element, the turbidity sensor and the pump in terms of control technology, wherein the method comprises the following method steps: activating the pump by the control device to pump the washing liquid from the turbidity detection area (especially from the alkali liquid container) into the discharge line; activating the fresh water supply element by the control device to supply fresh water to the turbidity detection area (especially the alkali liquid container); and storing, by the control device, the turbidity of the washing liquid in the turbidity detection area (especially in the alkali liquid container) detected by the turbidity sensor after the fresh water is supplied to the turbidity detection area (especially to the alkali liquid container) as a zero value for the turbidity sensor in order to calibrate the turbidity sensor.

[0053] This achieves the technical advantage that effective calibration of the turbidity sensor is ensured.

[0054] In an advantageous embodiment of the method, the activation of the pump and the activation of the fresh water supply element are carried out simultaneously or with a time offset by the control device, so that fresh water is supplied to the alkaline liquid container (or the turbidity detection area) simultaneously with the pumping out of the washing liquid from the alkaline liquid container (or the turbidity detection area) or with a time offset.

[0055] This achieves the technical advantage that a particularly effective fine adjustment is ensured between pumping out consumed washing liquid from the lye container (or from the turbidity detection area) and feeding fresh water into the lye container (or into the turbidity detection area).

[0056] In an advantageous embodiment of the method, the laundry care appliance comprises a laundry care substance supply element which is designed to supply laundry care substance to the washing liquid in the lye container, and the method comprises the further method steps of: activating the laundry care substance supply element by a control device after calibration of the turbidity sensor in order to supply laundry care substance to the washing liquid in the lye container and in the turbidity detection area; and detecting the concentration of the laundry care substance in the washing liquid as a function of the turbidity of the washing liquid in the lye container (or in the turbidity detection area) detected by the calibrated turbidity sensor.

[0057] This achieves the technical advantage that the concentration of the laundry care substance can be effectively monitored by the control device during the laundry care program by means of a calibrated turbidity sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] An embodiment of the invention is shown in the drawings and described in more detail below. The drawings show:

[0059] Figure 1 A schematic illustration of a laundry care appliance according to one embodiment in an initial state;

[0060] Figure 2 Shown in Figure 1 A schematic illustration of the laundry care appliance of the embodiment shown in FIG during the pumping out of the washing liquid;

[0061] Figure 3 Shown according to Figure 1 and 2 Schematic illustration of the laundry care appliance of the embodiment shown in FIG during the supply of fresh water with the pump activated;

[0062] Figure 4 Shown according to Figure 1 、 2 and a schematic view of the laundry care appliance of the embodiment shown in 3 in the final state; and

[0063] Figure 5 A schematic illustration of a method for calibrating a turbidity sensor in a laundry care appliance according to one embodiment is shown. DETAILED DESCRIPTION

[0064] Figure 1 The schematic diagram shows a general laundry care appliance 100, such as a washing machine. The laundry care appliance 100 has a lye container 101 for receiving washing liquid 103. The laundry care appliance 100 has a laundry drum 105 arranged in the lye container 101 for receiving laundry.

[0065] The lower region 101 - 1 of the laundry container 101 is fluidically connected to a drain line 107 of the laundry care appliance 100 , wherein the drain line 107 is connected to a drain opening 109 of the laundry care appliance 100 .

[0066] A pump 111 is arranged in the discharge line 107 , which is designed to pump the washing liquid 103 out of the laundry container 101 and out of the laundry care appliance 100 through the discharge line 107 .

[0067] The laundry care appliance 100 also has a fresh water supply element 113, which is fluidically connected to the laundry container 101 via a fresh water supply line 115 and is designed to supply fresh water to the laundry container 101. In particular, the fresh water supply element 113 comprises a valve that is connected to a fresh water connection of the laundry care appliance 100.

[0068] The laundry care appliance 100 further comprises a laundry care substance supply element 117 which is fluidically connected to the lye container 101 via a substance supply line 119 and is configured to supply laundry care substance to the lye container 101. In particular, the laundry care substance supply element 117 comprises Figure 1 A flushing receptacle (not shown) for receiving a laundry care substance, to which fresh water can be supplied in terms of fluid technology, in order to dissolve the laundry care substance in the fresh water and supply it as laundry care substance dissolved in the washing liquid 103 to the alkaline solution container 101 via the substance supply line 119. In particular, the laundry care substance supply element 117 comprises a further valve that is connected to the fresh water connection of the laundry care appliance 100.

[0069] Furthermore, a turbidity sensor 121 is arranged in the alkali liquid container 101 for detecting the turbidity of the washing liquid 103 received in the alkali liquid container 101. Therefore, in this preferred embodiment, the turbidity detection area in the area around the portion of the turbidity sensor 121 that performs the detection function is located in the lower area of ​​the alkali liquid container 101-1. Figure 1 Obviously, in the laundry care appliance 100 Figure 1 In the initial state shown in FIG, the liquid level 123 of the washing liquid 103 is located below the turbidity sensor 121 .

[0070] The laundry care appliance 100 Figure 1 A control device 125 , which is shown only schematically in FIG. 1 , is connected in terms of control technology to the turbidity sensor 121 , the pump 111 , the fresh water supply element 113 and the laundry care substance supply element 117 .

[0071] The turbidity sensor 121 particularly comprises an optical transmitter (particularly a light source emitting light) arranged in the washing liquid 103 and an optical receiver (particularly an optical detector) arranged in the washing liquid 103, which receives the light emitted by the optical transmitter, wherein the electronic analysis and processing device of the turbidity sensor 121 can determine the turbidity of the washing liquid 103 based on a comparison between the light emitted by the optical transmitter and the light received by the optical receiver, wherein, here, the turbidity detection area is the area between the optical transmitter and the optical receiver.

[0072] Since the turbidity of the washing liquor 103 is correlated in particular with the concentration of the laundry care substance in the washing liquor 103 , the concentration of the laundry care substance in the washing liquor 103 can be determined from the detected turbidity of the washing liquor 103 .

[0073] The laundry care appliance 100 Figure 1 The initial state shown in FIG1 represents the inactive state of the laundry care appliance. Due to the height difference between the outlet 109 and the liquid level 123 of the washing liquid 103 in the lye container 101, even after the previous pumping process, some of the washing liquid 103 that could not be pumped out remains in the laundry care appliance 100. In particular, if the laundry care appliance 100 does not have a lye container seal between the lye container 101 and the outlet line 107, after the pump 111 is turned off, some of the washing liquid 103 that was present during the previous pumping process may flow back from the outlet line 107 into the lye container 101, resulting in a liquid level 123 of the washing liquid 103 that may also be above the turbidity sensor 121 (i.e., above the turbidity detection area).

[0074] In alternative embodiments (not shown), the turbidity sensor 121 can also be arranged in the drain line 107 or in the antechamber of the pump 111. In such embodiments, the turbidity detection area is located outside the lye container 101. The turbidity detection area is fluidically connected to the lye container, so that the turbidity of the washing liquid 103 in the lye container 101 can be determined by detecting the turbidity of the washing liquid in the turbidity detection area outside the lye container 101, since the washing liquid 103 in the lye container 101 also reaches the turbidity detection area via the interconnected connection. In addition, the washing liquid 103 can be moved by activating the pump 111 or moving the laundry drum 105, thereby ensuring that the washing liquid moves within the interconnected connection and that the washing liquid in the turbidity detection area has the same state as the washing liquid 103 in the lye container 101. In embodiments with a turbidity detection area outside the lye container 101, the washing liquid 103 can also be fresh water, which can also be supplied from the lye container 101 via a fluidically connected connection to the turbidity detection area outside the lye container 101. Alternatively, the fresh water supply element 113 and / or the laundry care substance supply element 117 can be directly fluidically connected to the turbidity detection area outside the lye container 101 via a connection (not shown). This is particularly advantageous when the turbidity detection area is arranged below the lye container 101.

[0075] Because in Figure 1 The washing liquid 103 shown in the drain line 107 and the lye container 101 contains not only pollutants but also laundry care substances from previous laundry care processes, so that the washing liquid 103 does not correspond to fresh water, and thus the turbidity of the washing liquid 103 does not correspond to the turbidity of fresh water. For this reason, Figure 1 The turbidity of the washing liquid 103 shown in FIG is disadvantageous if it is used as a zero value when calibrating the turbidity sensor 121 .

[0076] For this reason, it is advantageous to calibrate the turbidity sensor 121 with the aid of fresh water in the lye container 101. For further details in this respect, reference is made to the detailed description of the subsequent figures.

[0077] As in Figure 2 As shown in FIG, the control device 125 is designed to activate the pump 111 during the turbidity sensor calibration process in order to pump the washing liquid 103 from the alkaline solution container 101 into the discharge line 107 .

[0078] from Figure 2It is clear that the pump 111 is activated by the control device 125, in particular with a pumping power that is sufficient to pump the washing liquid 103 from the lye container 101 up to a pumping level 127 in the discharge line 107, but the pumping level 127 is not high enough, however, to pump the washing liquid 103 out of the laundry care appliance 100 through the discharge opening 109.

[0079] In addition, as from Figure 2 Obviously, the control device 125 is configured to activate the fresh water supply element 113 during the turbidity sensor calibration process in order to supply fresh water 113-1 to the alkaline solution container 101. In particular, the control device 125 opens the valve of the fresh water supply element 113 simultaneously with or at a time offset from the pumping of the washing liquid 103 by the pump 111 in order to supply fresh water 113-1 to the alkaline solution container 101.

[0080] In particular, the control device 125 does not activate the laundry care substance supply element 117 , so that laundry care substance cannot be supplied to the lye container 101 , which could hinder the calibration of the turbidity sensor 121 .

[0081] In one of the not shown embodiments of the laundry care appliance 100 having a turbidity detection area outside the lye container 101, the turbidity sensor 121 is arranged in the laundry care appliance 100 such that the turbidity detection area is arranged upstream of the pump 111 in a line fluidically connected to the lye container 101, so that the washing liquid 103 present in the turbidity detection area can be removed by activating the pump 111.

[0082] Figure 3 Shown according to Figure 1 and Figure 2 Schematic illustration of a laundry care appliance 100 of the embodiment shown in FIG during fresh water supply.

[0083] Depend on Figure 3 It can be seen that the fresh water 113 - 1 supplied to the alkaline solution container 101 by the fresh water supply element 113 flows through the discharge line 107 and reaches the pump 111 .

[0084] It is particularly advantageous here to switch off the pump 111 as soon as the supplied fresh water 113 - 1 reaches the pump 111 .

[0085] In particular, after the fresh water supply period, the control device 125 can terminate the supply of fresh water 113 - 1 by deactivating the fresh water supply element 113 after the fresh water supply period. The fresh water supply period can be specified according to the appliance.

[0086] In particular, the laundry care appliance 100 may have Figure 3 A power detection element not shown in the figure is configured to detect an electrical power value of a pump drive of the pump 111, wherein the control device 125 is configured to deactivate the pump 111 when the electrical power value detected by the power detection element exceeds a power threshold.

[0087] When the supplied fresh water 113 - 1 reaches the pump 111 and is conveyed via the pump 111 , the electrical power requirement of the pump 111 increases, so that the electrical power value of the pump drive of the pump 111 exceeds a power threshold value.

[0088] By switching the pumping of the washing liquid 103 from the alkaline solution container 101 and the supply of fresh water 113 - 1 in a time-dependent manner, it is ensured in particular that no washing liquid 103 or only a small amount of washing liquid 103 is pumped out through the outlet 109 .

[0089] In this case, the control device 125 is designed in particular to terminate the fresh water supply simultaneously with the deactivation of the pump 111 or at a time offset therewith.

[0090] Figure 4 Shown according to Figure 1 、 2 3 are schematic illustrations of the laundry care appliance 100 of the embodiment shown in FIG. 3 in the final state.

[0091] exist Figure 4 In the end state shown in FIG, the pump 111 and the fresh water supply element 113 are deactivated, and equilibrium has already occurred between the washing liquid 103 in the alkaline solution container 101 and the washing liquid 103 in the discharge line 107 .

[0092] In particular, the control device 125 deactivates the fresh water supply element 113 at a point in time that ensures that the subsequent level 123 of the washing liquid 103 in the alkaline solution container 101 is above the turbidity sensor level 129 .

[0093] With the pump 111 switched off, the washing liquid 103 tends to flow back through the pump 111 and the discharge line 107 toward the lye container 101. However, since fresh water 113-1 is already present in the discharge line 107 and in the lye container 101, the returning washing liquid 103 now forces the fresh water 113-1 back into the lye container 101. This occurs until the liquid levels in the lye container 101 and in the discharge line 107 are once again equal.

[0094] During this return phase, a mixed state with respect to turbidity occurs in the immediate vicinity of the contact surface between the washing liquid 103 and the fresh water 113-1. However, in the area of ​​the turbidity sensor 121, only fresh water 113-1 is present in the final state, thus achieving the target state for advantageously calibrating the turbidity sensor 121.

[0095] During the calibration process of the turbidity sensor calibration, the control device 125 is configured to store the turbidity of the washing liquid 103 in the washing liquid container 101 detected by the turbidity sensor 121 as a zero value for the turbidity sensor 121 after fresh water 113-1 has been supplied to the alkali liquid container 101, in order to calibrate the turbidity sensor 121. Alternatively, if the turbidity detection area is already filled with fresh water 113-1, the turbidity sensor 121 can also be calibrated during the supply of fresh water 113-1. This can be confirmed by ensuring that the turbidity sensor 121 is not dry, which can be confirmed by measuring the fill level 123 of the washing liquid (here, fresh water) or by the turbidity sensor 121 itself.

[0096] The use of the described functions ensures that the zero value of the turbidity sensor 121 is set in a medium corresponding to the turbidity of the supplied fresh water 113-1. This ensures that the turbidity subsequently measured during the washing and rinsing processes actually occurs during these processes, minimizing calibration errors.

[0097] Processes such as the re-dosing of laundry care substances or the turbidity-dependent control of the washing process and / or the rinsing process can thus be adjusted more precisely to the requirements of the laundry care program.

[0098] Setting a zero value in a pre-turbid medium, which is inconsistent with the present disclosure, can lead to a difference between the turbidity of the medium and that of fresh water. This difference is included as a measurement error in the turbidity measurement during the washing process. This results in the measured turbidity being less than the actual value, and reduces the possibility of re-dosing detergent during the washing process or adding an additional rinse cycle during the rinse cycle. Consequently, the washing and rinsing results of corresponding conventional laundry care appliances may be reduced.

[0099] The regulated (or controlled) switching of the pump 111 disclosed herein ensures that no or only a small amount of washing liquid 103 is pumped out of the discharge line 107. Consequently, it is not necessary to refill with fresh water 113-1, or only a small amount of fresh water 113-1 is necessary to achieve the same fill level in the lye container 101 as when this process is not being performed. Therefore, this zeroing process results in virtually no additional water consumption.

[0100] Figure 5 A schematic illustration of a method for calibrating a turbidity sensor in a laundry care appliance 100 according to one exemplary embodiment is shown.

[0101] A first method step includes activating 201 the pump 111 by the control device 125 during the turbidity sensor calibration process in order to pump the washing liquid 103 from the alkaline solution container 101 into the discharge line 107 .

[0102] The second method step includes activating 203 the fresh water supply element 113 by the control device 125 during the turbidity sensor calibration process in order to supply fresh water 113 - 1 to the alkaline solution container 101 .

[0103] The third method step includes storing 205 the turbidity of the washing liquid 103 in the alkali liquid container 101 detected by the turbidity sensor 121 as a zero value for the turbidity sensor 121 by the control device 125 after the fresh water 113 - 1 has been supplied to the alkali liquid container 101 , in order to calibrate the turbidity sensor 121 .

[0104] All features explained and shown in conjunction with individual embodiments of the invention can be provided in various combinations in the subject matter according to the invention in order to simultaneously achieve their advantageous effects.

[0105] The scope of protection of the present invention is given by the claims and is not limited by the features explained in the description or shown in the drawings.

[0106] Reference Signs List

[0107] 100 laundry care appliances

[0108] 101 Lye container

[0109] 101-1 Lower area of ​​lye container

[0110] 103 detergent

[0111] 105 laundry drum

[0112] 107 discharge line

[0113] 109 outlet

[0114] 111 Pump

[0115] 113 Fresh water supply element

[0116] 113-1 Fresh Water

[0117] 115 Fresh water supply line

[0118] 117 laundry care material supply element

[0119] 119 Material supply pipeline

[0120] 121 Turbidity Sensor

[0121] 123 Washing fluid level

[0122] 125 Control Device

[0123] 127 Pump out level

[0124] 129 Turbidity sensor level

[0125] 200 Method for calibrating turbidity sensors

[0126] 201 First method step: Pump activation

[0127] 203 Second method step: Activation of the fresh water supply element

[0128] 205 Third method step: Calibration of turbidity sensor

Claims

1. A laundry care appliance (100), comprising: a lye container (101) for receiving a washing liquid (103), a turbidity sensor (121) for detecting the turbidity of the washing liquid (103) received in the lye container (101), wherein: The turbidity sensor (121) is arranged in a turbidity detection area, which is located in the alkali liquid container (101) or in a pipeline that is fluidically connected to the alkali liquid container (101); a fresh water supply element (113) that is fluidically connected to the turbidity detection area and is configured to supply fresh water (113-1) to the turbidity detection area; a discharge line (107) that fluidically connects the turbidity detection area to an outlet (109) of the laundry care appliance (100); a pump (111) that is arranged in the discharge line (107) and is configured to pump the washing liquid (103) out of the turbidity detection area and out of the laundry care appliance (100) via the discharge line (107); and A control device (125) is connected to the fresh water supply element (113), to the turbidity sensor (121) and to the pump (111) in terms of control technology, characterized in that the control device (125) is configured to: activate the pump (111) to pump the washing liquid (103) from the turbidity detection area into the discharge line (107), and the control device (125) is configured to: activate the pump (111) during a turbidity sensor calibration process to pump the washing liquid (103) from the lye container (101) to a pump-out level (127) in the discharge line (107), wherein the pump-out level (127) is higher than the level of the lye container (101). 1), but not so high that the washing liquid (103) is pumped out of the laundry care appliance (100) through the outlet (109), the control device (125) is configured to: activate the fresh water supply element (113) so as to supply fresh water (113-1) to the turbidity detection area, and the control device (125) is configured to: after the fresh water (113-1) is supplied to the turbidity detection area, store the turbidity of the washing liquid (103) in the turbidity detection area detected by the turbidity sensor (121) as a zero value for the turbidity sensor (121) so as to calibrate the turbidity sensor (121).

2. The laundry care appliance (100) according to claim 1, characterized in that: The control device (125) is configured to activate the fresh water supply element (113) simultaneously with or with a time offset with the pump (111) so as to supply fresh water (113-1) to the alkaline solution container (101) simultaneously with or with a time offset with the pumping of the washing liquid (103) from the turbidity detection area.

3. The laundry care appliance (100) according to claim 1 or 2, characterized in that: The control device (125) is configured to terminate the supply of the fresh water (113-1) after a fresh water supply period.

4. The laundry care appliance (100) according to claim 1 or 2, characterized in that: The laundry care appliance (100) has a liquid level sensor, which is arranged in the alkaline solution container (101) and is configured to detect the liquid level of the washing liquid (103) in the turbidity detection area, wherein the control device (125) is configured to terminate the supply of the fresh water (113-1) when the liquid level of the washing liquid (103) detected by the liquid level sensor exceeds a liquid level threshold value.

5. The laundry care appliance (100) according to claim 4, characterized in that: The filling level sensor is arranged in the lower region of the lye container (101).

6. The laundry care appliance (100) according to claim 1 or 2, characterized in that: The laundry care appliance (100) has a power detection element, which is configured to detect an electric power value of a pump drive of the pump (111), wherein the control device (125) is configured to deactivate the pump (111) when the electric power value detected by the power detection element exceeds a power threshold value.

7. The laundry care appliance (100) according to claim 6, characterized in that: The control device (125) is designed to terminate the supply of the fresh water (113-1) simultaneously or at a time offset after the pump (111) has been deactivated.

8. The laundry care appliance (100) according to claim 6, characterized in that: The control device (125) is configured to terminate the supply of the fresh water (113-1) when the electric power value detected by the power detection element exceeds a power threshold value.

9. The laundry care appliance (100) according to any one of claims 1, 2, 5, 7, and 8, characterized in that: The turbidity sensor (121) is configured to detect the turbidity of the washing liquid (103) in the turbidity detection area, and the control device (125) is configured to calibrate the turbidity sensor (121) when the liquid level (123) of the washing liquid (103) in the turbidity detection area is higher than the turbidity sensor liquid level (129).

10. The laundry care appliance (100) according to any one of claims 1, 2, 5, 7, and 8, characterized in that: There is no lye container seal between the turbidity detection area and the discharge line (107), so as to ensure the exchange of washing liquid (103) between the lye container (101) and the discharge line (107).

11. The laundry care appliance (100) according to any one of claims 1, 2, 5, 7, and 8, characterized in that: The laundry care appliance (100) has a laundry care substance supply element (117), which is configured to supply laundry care substance to the washing liquid (103) in the alkali liquid container (101), and the control device (125) is configured to activate the laundry care substance supply element after calibrating the turbidity sensor (121) so as to supply laundry care substance to the washing liquid (103) in the alkali liquid container (101) and in the turbidity detection area, wherein the control device (125) is configured to detect the concentration of the laundry care substance in the washing liquid (103) in the turbidity detection area based on the turbidity of the washing liquid (103) detected by the calibrated turbidity sensor (121).

12. The laundry care appliance (100) according to any one of claims 1, 2, 5, 7, and 8, characterized in that: The control device (125) is configured to execute a laundry care program of the laundry care appliance (100) after calibrating the turbidity sensor (121), wherein the control device (125) is configured to change a washing step and / or a rinsing step of the laundry care program according to the turbidity of the washing liquid (103) in the turbidity detection area detected by the calibrated turbidity sensor (121).

13. A method (200) for calibrating a turbidity sensor (121) of a laundry care appliance (100), wherein: The laundry care appliance (100) comprises: - a lye container (101) for receiving a washing liquid (103), - a turbidity sensor (121) for detecting the turbidity of the washing liquid (103) received in the lye container (101), wherein the turbidity sensor (121) is arranged in a turbidity detection area, the turbidity detection area being located in the lye container (101) or in a pipeline connected to the lye container (101) in terms of fluid technology, - a fresh water supply element (113) being connected in terms of fluid technology to the turbidity detection area and being configured to supply fresh water (113-1) to the turbidity detection area, - a discharge line (107) which connects the turbidity detection area in terms of fluid technology to an outlet (109) of the laundry care appliance (100), - a pump (111) arranged in the discharge line (107) and configured to pump the washing liquid (103) out of the turbidity detection area and out of the laundry care appliance (100) via the discharge line (107), and A control device (125) is connected to the fresh water supply element (113), to the turbidity sensor (121) and to the pump (111) in terms of control technology, characterized in that the method (200) comprises the following method steps: the control device (125) activates (201) the pump (111) to pump the washing liquid (103) from the turbidity detection area into the discharge line (107); during the turbidity sensor calibration process, the pump (111) is activated to pump the washing liquid (103) from the lye container (101) up to a pump-out level (127) in the discharge line (107), wherein the pump-out level (127) is higher than the turbidity container ( 101), but not so high that the washing liquid (103) is pumped out of the laundry care appliance (100) through the outlet (109); the control device (125) activates (203) the fresh water supply element (113) to supply fresh water (113-1) to the turbidity detection area; and after the fresh water (113-1) is supplied to the turbidity detection area, the control device (125) stores (205) the turbidity of the washing liquid (103) in the turbidity detection area detected by the turbidity sensor (121) as a zero value for the turbidity sensor (121) to calibrate the turbidity sensor (121).

14. The method (200) according to claim 13, characterized in that The control device (125) activates (201) the pump (111) and activates (203) the fresh water supply element (113) simultaneously or at a time offset, so that fresh water (113-1) is supplied to the turbidity detection area simultaneously with the pumping of the washing liquid (103) from the turbidity detection area or at a time offset.

15. The method (200) according to claim 13 or 14, characterized in that The laundry care appliance (100) has a laundry care substance supply element (117) which is configured to supply laundry care substance to the washing liquid (103) in the lye container (101), and the method comprises the following further method steps: after calibration of the turbidity sensor (121), activating the laundry care substance supply element by the control device (125) to supply laundry care substance to the washing liquid (103) in the lye container (101) and in the turbidity detection area; and detecting the concentration of the laundry care substance in the washing liquid (103) based on the turbidity of the washing liquid (103) in the turbidity detection area detected by the calibrated turbidity sensor (121).

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