Method for operating an automatic washing device and automatic washing device

Abstract

The present application relates to a method for operating a washing machine (1), the washing machine (1) comprising a tub (2), a rotatable washing drum (4), a drum drive, a circulation pump (5) for conveying liquid located in the tub (2) to textiles located in the washing drum (4), at least one level sensor device (7) with at least one level sensor (8) and a control device (9).

Description

[0001] The invention relates to a method for operating a washing machine according to claim 1. Furthermore, the present application relates to a washing machine for washing textiles according to claim 16.

[0002] The washing machine comprises a tub in which a washing drum is mounted so as to be rotatably driven. The washing machine also has a drum drive by means of which the washing drum can be driven so as to rotate about its axis of rotation. The washing machine further comprises a circulation pump by means of which liquid contained in the tub can be circulated into the tub, wherein the circulation pump is configured such that the liquid can be conveyed onto textiles located in the washing drum. For this purpose, the circulation pump can cooperate in particular with a liquid line by means of which the liquid conveyed by the circulation pump can be guided to an upper end of the washing drum, so that during operation of the circulation pump, the liquid, which is typically drawn from near the bottom of the tub, can be directed from above onto the textiles located in the washing drum.The washing machine further comprises at least one fill level sensor device, which in turn comprises at least one fill level sensor. This is suitable for detecting information regarding the liquid fill level of the tub. To process this information, the washing machine further comprises a control device that is connected to the fill level sensor device in a data-transmitting manner, so that the information detected by the fill level sensor can be transmitted to the control device and processed by it.

[0003] It is already known in the art to determine the saturation level of the textiles in the washing drum. This is important for a water supply control system, which is intended to automatically control how much water is introduced into the tub for a particular wash cycle. To determine the saturation level of the textiles, it is first necessary to determine the volume flow that can be or is expelled from the textiles during a specific expulsion period.

[0004] In the current technology, to determine this volume flow, the circulation pump is activated and the washing drum's discharge speed is simultaneously increased until a predefined pressure level is reached at a pressure sensor installed in the tub. Due to its design, this method requires the washing drum's discharge speed to be raised to a very high level, which places both significant mechanical stress on the washing machine's components and results in high noise emissions. Increasing the discharge speed to this high level is necessary to expel sufficient water from the textiles so that a pressure increase can be reliably measured at the pressure sensor.

[0005] Document DE 10 2016 212490 A1 discloses an automatic washing machine which, by detecting electrical conduction values of the pumping device, enables an effective indirect determination of volume flows of the washing liquid pumped by the pumping device in the pumping system.

[0006] The present application is based on the object of being able to determine the volume flow of liquid expelled from the textiles more easily.

[0007] The underlying problem is solved according to the invention by means of the method having the features of claim 1. Advantageous embodiments emerge from the associated subclaims.

[0008] The method according to the invention is carried out as follows: The washing drum is driven to rotate about its axis of rotation. This can be done, in particular, such that the washing drum has a constant speed. Simultaneously, the circulation pump is operated so that liquid in the tub is pumped onto the textiles. This operating state is maintained until the tub fill level reaches a previously defined value. The fill level is monitored by the level sensor device, which records the corresponding information.

[0009] Preferably, the information is continuously recorded by the fill level sensor device. "Continuously" in this context means recording the information using at least one fill level sensor at a specific sampling frequency. The latter is advantageously at least 50 Hz, preferably at least 100 Hz.

[0010] Once the fill level in the suds container has reached the defined value, the circulation pump is switched off. The defined value that leads to this break can, in particular, be 0 mm water column. In this scenario, the circulation pump is therefore only switched off after all of the liquid in the suds container has been pumped onto the textiles by the circulation pump, so that no liquid remains in the suds container. It can be assumed that, due to the rotary drive of the washing drum, liquid will constantly escape from the textiles into the suds container. However, this liquid is immediately circulated back onto the textiles by the circulation pump. Alternatively, it is also conceivable that the defined fill level, after which the circulation pump is switched off, corresponds to the suds container being filled with a specific volume of liquid that is different from zero.

[0011] In the context of the present application, switching off the circulation pump "after reaching the defined value" can, on the one hand, mean an immediate shutdown at the moment the defined value is reached. On the other hand, it is conceivable that the circulation pump is only switched off after a certain grace period after reaching the defined value, for example, after a few seconds. Thus, it is conceivable that the fill level of the lye container reaches the defined value, for example, 0 mm water column, and the circulation pump is not switched off until, for example, five seconds after this point in time.

[0012] In any case, the washing drum continues to rotate, with the liquid expelled from the textiles gradually collecting in the tub because the circulation pump is no longer active. The expulsion speed at which the washing drum operates after the circulation pump is switched off can be the same as the washing drum's speed when the circulation pump was switched on. It is also conceivable that the washing drum's expulsion speed is changed from its previous speed. In particular, the expulsion speed can be between 50 rpm and 900 rpm.

[0013] While the washing drum continues to rotate, information regarding the liquid fill level in the tub is recorded by the fill level sensor device. This information is sent to the control device and processed by it. A volume flow of the expelled liquid is then determined. For this purpose, the information from the fill level sensor device is processed, whereby, for example, a respective fill level in the tub can correspond to a known volume of expelled liquid. The relationship between the fill level and the volume of expelled liquid that is in the tub at the fill level is given by the geometry of the tub. Since this geometry is known, the volume of expelled liquid can be directly derived from a respectively recorded fill level.It is conceivable that the volume of expelled liquid can be represented as a function of the fill level of the suds container. Furthermore, it is conceivable that the volume of liquid present in the suds container is known for at least one defined fill level, which is detected by means of at least one fill level sensor of the fill level sensor device. Preferably, the information that a certain volume of liquid is present in the suds container at a defined fill level is known for several different fill levels. The different fill levels can be detected by means of exactly one fill level sensor or by means of different fill level sensors of the fill level sensor device. The volume of expelled liquid corresponds to the difference between the volumes of liquid present in the suds container that existed at the two fill levels.

[0014] With the known volume of expelled liquid, it is necessary to determine the volume flow rate by dividing the volume by the duration of an expulsion period over which the volume was expelled from the textiles. The result describes a volume flow rate, for example, in liters per minute [l / m], that was averaged out of the textiles during the expulsion period. The expulsion period extends from a beginning to an end, with one of the two volumes forming the difference described above being in the lye container at the beginning and the other at the end.

[0015] The method according to the invention has many advantages. In particular, it is not necessary, as in the prior art, to increase the expulsion speed of the washing drum to the described high level (in the prior art, over 1000 rpm is regularly required). Instead, the volume flow of the expelled liquid can be determined using a significantly lower expulsion speed of the washing drum, for example, with an expulsion speed of 350 rpm. The mechanical stress on the components of the washing machine is thus reduced when using the method according to the invention, as are the noise emissions from the washing machine during the process.

[0016] In a particularly preferred embodiment, the expulsion period extends between two points in time at which the volume of liquid in the suds container is known. A first point in time can in particular be the point in time at which the circulation pump is switched off, at which point in time, according to the above description, the fill level in the suds container can be, for example, 0 mm water column. The second point in time can in particular be a point in time at which a specific fill level in the suds container with liquid, different from zero, is detected by means of at least one fill level sensor of the fill level sensor device. In this embodiment, the volume that was expelled from the textiles during the expulsion period corresponds to the volume that results from the fill level detected by the fill level sensor at the second point in time.The duration of the expulsion period advantageously corresponds to the time difference between the two specified times. This means that all values for the above-described division of the volume by the duration of the expulsion period are known, allowing the average volume flow of the expelled liquid to be determined.

[0017] According to the above explanation, it is advantageous if the points in time that define the beginning and end of the expulsion period are those at which the liquid level in the lye container has reached a previously defined value. This procedure has the advantage that the volume of expelled liquid can be determined particularly easily at these fill levels, since the fill levels, whose values are defined, can be linked to the volumes of liquid in the lye container. This can be achieved, in particular, by pre-filling the lye container with liquid up to a specific fill level, after which the volume of liquid admitted into the lye container is measured ("calibration"). This can, of course, also be determined digitally using appropriate design models.

[0018] Accordingly, it can be particularly advantageous if the volume of liquid expelled over the duration of the expulsion period is determined based on fill levels that existed at the times between which the expulsion period extends. The fill levels correspond to a filling of the lye container with a specific volume of liquid. The resulting advantages have already been explained above.

[0019] It is also conceivable that the fill levels, which when reached define the expulsion period, are not determined in advance, but rather the expulsion period is determined conversely, i.e. the two points in time that define the start and end of the expulsion period. At these defined points in time, the fill level of the lye container with liquid is determined using the fill level sensor device, whereby the fill levels each correspond to a volume of liquid that was in the lye container at the respective times. The volume of liquid expelled in the expulsion period is calculated from the difference between the volumes of the liquid at the start and end of the expulsion period. The duration of the expulsion period is also known (time difference between the start and end of the expulsion period), so that all values for determining the average volume flow are available.

[0020] In an advantageous embodiment of the method, the speed of the washing drum can be accelerated to a desired discharge speed before the circulation pump is switched off. The discharge speed can, in particular, be determined automatically by the control device.

[0021] Preferably, the discharge speed remains unchanged after the circulation pump is switched off. A value between 50 rpm and 900 rpm, preferably between 100 rpm and 500 rpm, and more preferably between 200 rpm and 400 rpm, is particularly conceivable as the discharge speed.

[0022] Regardless of whether the expulsion speed of the washing drum is changed after the circulation pump is switched off, it can be particularly advantageous if the expulsion speed is kept constant at least during the expulsion period. This is advantageous for using the determined value of the average volume flow of the expelled liquid over the duration of the expulsion period. In particular, it is possible to use the value of the average volume flow for further evaluations, in particular by drawing on empirically determined relationships between the average volume flow and other parameters. In order to be able to use the average volume flow as an input variable for such relationships, it is advantageous if the expulsion speed is kept constant during the expulsion period.

[0023] Furthermore, it can be particularly advantageous to determine the mass of all textiles in the washing drum. This can be done, in particular, using a mass inertia method, with the mass of the textiles preferably being determined while they are in a dry state. The parameter of the mass of the textiles, preferably in a dry state, can also be used as an input parameter for further evaluations.

[0024] For the same reason, it can be particularly advantageous to measure the amount of liquid introduced into the lye tank, preferably using an inlet sensor. Such a sensor can be formed, for example, by an impeller meter, which measures the volume of liquid introduced into the lye tank. This makes it possible to determine the total amount of liquid in the lye tank while the process is being carried out.

[0025] If both the mass of the textiles and the amount of liquid introduced are determined, it is particularly advantageous if the expulsion speed is automatically determined by the control device based on the amount of liquid introduced into the tub and the mass of all textiles in the washing drum. This automatically determines the expulsion speed for each individual case, allowing the average volume flow to be determined with particular reliability. The function of the expulsion speed as a function of the mass of the textiles and the amount of liquid can be determined in advance based on empirical studies.

[0026] Furthermore, such a method is particularly advantageous in which an empirical model is used to determine the theoretical moisture content that the textiles would have at the end of the expulsion period if they were made entirely of a defined material. The input variables for the empirical model can preferably be the averaged volume flow of the liquid expelled from the textiles over the expulsion period, the expulsion speed at which the washing drum was rotated during the expulsion period, and the volume of liquid introduced into the tub. In particular, it is conceivable that the theoretical moisture content is determined for various defined materials, with a correspondingly calibrated empirical model being used for each material. In particular, it can be advantageous if the theoretical moisture content is determined at least for the materials terry cloth and synthetics.Experience has shown that these materials represent two opposing extremes in their ability to retain liquids. Terry cloth is particularly well-suited to retaining liquids, while synthetic materials, on the other hand, exhibit particularly poor retention.

[0027] In a further development of the method, it is particularly advantageous if the actual moisture content of the textiles is also determined. This is done by dividing the total volume of liquid introduced into the tub by the mass of all textiles in the washing drum. The resulting calculated value describes the actual moisture content of the textiles in the washing drum, for example, in liters per kilogram [I / kg].

[0028] The actual moisture content of the textiles determined in this way can then be used to determine the composition of the textiles in the washing drum. In a further advantageous embodiment of the method, this is achieved by interpolating the actual moisture content of the textiles between at least two theoretical moisture contents for different materials. Thus, for example, the actual moisture content can be interpolated between the theoretical moisture contents of the terry cloth and synthetic materials. In this way, it is possible, in particular, to determine the mixing ratio of the textiles in the washing drum with respect to the materials between which the interpolation was carried out.

[0029] The underlying problem is further solved by means of a washing machine having the features of claim 16. Advantageous embodiments emerge from the associated subclaims.

[0030] The control device of the washing machine according to the invention is provided and configured to operate the drum drive and the circulation pump depending on the information detected by the fill level sensor device in such a way that the method steps of the method according to the invention are carried out. The washing machine is therefore particularly well suited to carrying out the method according to the invention. The resulting advantages have already been explained above. In particular, a volume flow of liquid expelled from the textiles in the washing drum over the duration of an expulsion period can be determined particularly easily, whereby the washing machine and its components are protected and noise emissions are reduced compared to the prior art.

[0031] The washing machine is particularly advantageous if it has at least one inlet sensor for detecting information regarding the amount of liquid introduced into the tub. The inlet sensor can be designed, in particular, to determine the volume of all liquid introduced into the tub. For this purpose, the inlet sensor can be formed, for example, by an impeller meter.

[0032] Furthermore, such an automatic washing machine can be advantageous in which at least one fill level sensor of the fill level sensor device is arranged at a vertically measured distance from a bottom of the tub. In this embodiment, the information from the fill level sensor can be interpreted to mean that at the moment the fill level sensor comes into contact with liquid, the tub is filled with a certain volume of liquid, which corresponds to a fill level of the tub with liquid that corresponds to the distance of the fill level sensor from the bottom of the tub. With knowledge of the geometry of the tub, the volume of liquid in the tub is thus known. In this case, the fill level sensor can be formed in particular by a pressure sensor or a contact sensor, wherein the latter can be used to determine the moment at which the fill level sensor comes into contact with liquid.Using a pressure sensor, the fill level can be determined based on the hydraulic pressure acting on the pressure sensor. Knowing the geometry of the suds container, this information can also be used to determine the volume of liquid in the suds container.

[0033] It is also conceivable for a fill level sensor to be arranged in the bottom of the tub. In this embodiment, the fill level sensor can be formed, in particular, by a pressure sensor, by means of which the hydraulic pressure of a liquid column resting on the pressure sensor can be detected. The height of the liquid column and thus the fill level of the tub can be determined from the hydraulic pressure. The arrangement of the fill level sensor in the bottom of the tub allows the level sensor to determine that there is no or almost no liquid in the tub.

[0034] Furthermore, it can be particularly advantageous if the fill level sensor device comprises a plurality of fill level sensors arranged at different distances from the bottom of the tub. In this way, at different times during the expulsion of liquid from the textiles in the washing drum, the volumes of liquid that were in the tub at these times can be determined. In this embodiment, the times can be defined in particular by the fact that the fill level sensors each came into contact with the liquid for the first time. From this, it can be concluded that the tub is or was filled at these times with a volume of liquid that corresponds to a fill level of the tub that corresponds to the distance of the respective fill level sensor from the bottom of the tub.The times at which the fill level sensors come into contact with the liquid are particularly well suited to defining the beginning and end of the expulsion period, while the volumes corresponding to the detected fill levels are particularly well suited to determining the volume expelled from the textiles during the expulsion period. In this embodiment, the fill level sensors are preferably contact sensors.

[0035] An embodiment of the invention is shown purely schematically in the drawings and is described in more detail below. It shows: Figure 1A schematic representation of a washing machine according to the invention.

[0036] An example of implementation that Figure 1 illustrated, comprises a washing machine 1, which has a lye container 2 and one inside the tub 2 rotating washing drum4 The washing drum 4 is about an axis of rotation 3 mounted on a rotatable drive, whereby the washing drum 4 is rotatably driven by a drum drive not shown in the figure. In the washing drum 4 are textiles 6 stored, which are to be washed using the washing machine 1.

[0037] Furthermore, the washing machine includes 1 a circulation pump 5, which is intended and equipped to be used in the lye container 2 liquid in the washing drum 4 textiles 6 To do this, the circulation pump 5 with a liquid line 12 together, which directs the circulated liquid to an upper end of the washing drum 4 so that the circulated liquid flows from above onto the textiles 6 This can be done by connecting one of the circulation pumps5 opposite end of the liquid line 12 a nozzle (not shown in the figure) can be arranged, by means of which the liquid is sprayed onto the textiles 6 The suction of the liquid from the lye container 2 using the circulation pump 5 occurs in the area of the floor 13 the suds container 2, so that the circulation pump 5 all in the lye container 2 liquid from the lye container 2 can be seen.

[0038] Furthermore, the washing machine includes 1 a supply line 14, by means of the liquid from a liquid supply not shown in the figure into the tub 2 can be introduced, whereby to convey the liquid into the tub 2 in the example shown a pump 11 is provided. In the supply line 14In the example shown, an inlet sensor 10 which here is formed by a vane meter. The inlet sensor 10 is therefore suitable for storing information concerning a volume of 2 introduced liquid.

[0039] Furthermore, the washing machine includes 1 a level sensor device 7, which in the example shown is a level sensor 8 This is in a floor 13 the suds container 2 The level sensor 8 is formed here by a pressure sensor which is intended and set up to continuously record information concerning a hydraulic pressure applied to a sensor surface, which is exerted on the level sensor by a water column 8 acts.

[0040] This information becomes a control device 9 of the washing machine1 so that the control device 9 which is measured by means of the level sensor device 7 information collected to ensure the operation of the washing machine 1 to control. The control device 9 In the example shown, it is also connected to the inlet sensor in a data transmitting manner 10 connected so that the inlet sensor 10 recorded information to the control device 9 conductive and can also be processed by means of them.

[0041] When carrying out the method according to the invention, before introducing liquid into the lye container 2 using a mass inertia method, a mass of all textiles 6 is determined which, in the dry state, are in the washing drum 4 Then, using the pump 11 Liquid through the supply line 14 into the suds container 2The inlet sensor is used to 10 the total volume of liquid introduced is recorded. Furthermore, the washing drum 4 around its axis of rotation 3 by means of the drum drive and at the same time the circulation pump 5 operated. The washing drum 4 is hereby referred to a control device 9 automatically determined speed, which depends on the mass of the textiles 6 and the amount of liquid introduced.

[0042] Using the circulation pump 5 the solution in the tub 2 liquid contained in the liquid line 12 on the washing drum 4 textiles 6 This process is maintained until the level sensor device 7detects that the filling level of the lye container 2 0 mm water column. In other words, at this point, all the liquid in the tub is 2 is located in the textiles 6 After a waiting time of five seconds, the circulation pump is then 5 deactivated while the washing drum 4 continues to operate at the speed to which it was previously accelerated. This speed thus forms the discharge speed of the washing drum 4, that is, the speed at which the washing drum 4 is also operated during the expulsion period. In the example shown, it remains after the circulation pump is switched off 5 constant.

[0043] Due to the continuous rotation of the washing drum 4 liquid is released from the textiles 6 expelled, which then settles in the lye container 2This means that the level of the lye container increases 2 This change is detected by the level sensor 8 the level sensor device 7 Since the fill level of the lye container 2 using the level sensor device 7 is continuously recorded, here at a frequency of 200 Hz, information is available regarding a change in the fill level over time. At a defined time after the circulation pump is switched off 5, For example, after 20 seconds, the filling level of the solution container at that time is 2 recorded.

[0044] To determine the average volume flow, a corresponding volume of the liquid in the lye container is determined at the fill level that existed at the defined time. 2is or was at this time. The value of this volume, which depends on the fill level of the lye container 2 corresponds, can be known in particular from a previous determination. Since at the time the circulation pump is switched off 5 the fill level of the suds container 2 was zero, the volume determined at the defined time corresponds to the volume that has been measured since the circulation pump was switched off 5 from the textiles 6 was expelled. The corresponding times, ie the time of switching off the circulation pump 5 and the defined time one minute after switching off the circulation pump 5, mark the beginning and end of an expulsion period, during which the determined volume from the textiles 6was expelled. This duration is also one minute. The average volume flow is finally determined by dividing this volume by the duration of the expulsion period.

[0045] Furthermore, the process is operated in such a way that a composition of the substances in the washing drum 4 textiles 6 For this purpose, two values for a theoretical moisture content of the textiles 6 determined which the textiles 6 at the end of the expulsion period if they were made entirely of the respective materials. To do this, before introducing liquid into the lye tank 2 using an inertia method the mass of the textiles 6 which, when dry, can be stored in the washing drum 4 This mass is 4.0 kg in this example. Furthermore, the inlet sensor 10It has been determined that a volume of 6.4 l of liquid in the lye container 2 The average volume flow of expelled liquid determined according to the above method is 1.5 l / min in the example shown. The washing drum was 4 operated at an output speed of 325 rpm, whereby this speed depends on the mass of the textiles 6 and the amount of liquid introduced was automatically determined. Knowing this ejection speed, the mass of the liquid entering the washing drum 4 introduced textiles 6 and the averaged volume flow, the theoretical moisture of the textiles is determined using an empirical model 6determined what they would have if they were made entirely of terry cloth and synthetic material. The theoretical moisture content for terry cloth is 2.0 l / kg, and the theoretical moisture content for synthetic material is 1.2 l / kg. It is also known how much liquid is released from the textiles at the end of the expulsion period. 6 has been expelled, so that conversely it is also known how much liquid is still in the textiles 6 In addition, the actual moisture content of the textiles can be determined, which in the example shown is 1.6 l / kg.

[0046] After all, the actual moisture content of the textiles 6 geometrically exactly in the middle between the theoretical moisture content of terry cloth and synthetic material. This allows conclusions to be drawn about the material from which the textiles are made. 6 are educated. List of reference symbols

[0047] 1 Washing machine 2 Tub 3 Rotary axis 4 Washing drum 5 Circulation pump 6 Textiles 7 Level sensor device 8 Level sensor 9 Control device 10 Inlet sensor 11 Pump 12 Liquid line 13 Floor 14 Supply line

Claims

1. Method for operating a washing machine (1), the washing machine (1) comprising - a suds container (2), - a washing drum (4) arranged in the suds container (2) and rotationally drivable about an axis of rotation (3), - a drum drive for rotationally driving the washing drum (4) about its axis of rotation (3), - a circulation pump (5) for pumping liquid in the suds container (2) onto textiles (6) in the washing drum (4), - at least one filling level sensor device (7) having at least one level sensor (8) for capturing information relating to a fill level of liquid in the suds container (2), - a control device (9), the method comprising the following method steps: a) the washing drum (4) is rotationally driven about its axis of rotation (3); b) the circulation pump (5) is operated in order to pump liquid in the suds container (2) onto the textiles (6) until the information captured by the filling level sensor device (7) indicates that the fill level of the suds container (2) corresponds to a previously defined value; c) after the fill level has reached the defined value, the circulation pump (5) is switched off while the washing drum (4) continues to be rotated, whereby liquid is expelled from the textiles (8) and collects in the suds container (2); d) information relating to the fill level of the suds container (2) is captured by means of the filling level sensor device (7) and is transmitted to the control device (9); e) the information is processed by means of the control device (9) in such a way that a volume of expelled liquid, which is determined on the basis of at least one fill level, is divided by a duration of an expulsion period, whereby a volume flow of the expelled liquid averaged over the expulsion period is determined.

2. Method according to claim 1, characterised in that the fill level at which the circulation pump (5) is switched off is 0 mm water column.

3. Method according to any of the preceding claims, characterised in that the expulsion period spans two points in time at which the volume of liquid with which the suds container (2) was filled is known.

4. Method according to claim 3, characterised in that the points in time that define the expulsion period are those at which the fill level has reached a previously defined value.

5. Method according to claim 3 or 4, characterised in that the volume of the liquid expelled over the duration of the expulsion period is determined on the basis of fill levels that occurred at the points in time spanned by the expulsion period, wherein the fill levels each correspond to a filling of the suds container (2) with a certain volume of the liquid.

6. Method according to any of the preceding claims, characterised in that the washing drum (4) is accelerated to an expulsion rotational speed before the circulation pump (5) is switched off.

7. Method according to any of the preceding claims, characterised in that the expulsion rotational speed is kept constant during the expulsion period.

8. Method according to any of the preceding claims, characterised in that a mass of all textiles (6) in the washing drum (4) is determined, in particular by means of a mass inertia method, wherein the mass of the textiles (6) is determined preferably while they are in a dry state.

9. Method according to any of the preceding claims, characterised in that a quantity of the liquid introduced into the suds container (2) is detected, in particular by means of an inlet sensor (10).

10. Method according to claims 8 and 9, characterised in that the expulsion rotational speed is automatically set by means of the control device (9) depending on the quantity of liquid introduced into the suds container and the mass of all textiles in the washing drum (4).

11. Method according to any of the preceding claims, characterised in that the circulation pump (5) is switched off immediately when the fill level has reached the defined value or after a waiting period has elapsed.

12. Method according to any of the preceding claims, characterised in that, by means of an empirical model, a theoretical moisture content is determined, which the textiles would have at the end of the expulsion period if they were completely made of a defined material, wherein at least the average volume flow of the expelled liquid, the expulsion rotational speed at which the washing drum (4) was rotated during the expulsion period, and the mass of the total liquid introduced into the suds container (2) are used as input variables for the empirical model.

13. Method according to claim 12, characterised in that the theoretical moisture content for terry cloth and synthetic material is determined.

14. Method according to claim 12 or 13, characterised in that an actual moisture content of the textiles (6) is determined by F = V / M where: F = actual moisture content of the textiles (6) in the washing drum (4) at the end of the expulsion time V = total volume of the liquid that was introduced into the suds container (2) M = mass of all textiles (6) in the washing drum (4)15. Method according to claim 14, characterised in that a composition of textiles made of different materials is determined by interpolating the actual moisture content of the textiles between theoretical moisture contents for different materials.

16. Washing machine (1) for washing textiles (6), comprising - a suds container (2), - a washing drum (4) arranged in the suds container (2) and rotationally drivable about an axis of rotation (3), - a drum drive for rotationally driving the washing drum (4) about its axis of rotation (3), - a circulation pump (5) for pumping liquid in the suds container (2) onto textiles (6) in the washing drum (4), - at least one filling level sensor device (7) having at least one level sensor (8) for capturing information relating to a fill level of liquid in the suds container (2), - a control device (9), wherein the control device (9) is connected to the filling level sensor device (7) in a data-transmitting manner, wherein the control device (9) is provided and configured to operate the drum drive and the circulation pump (5), depending on the information captured by the filling level sensor device (7), as follows: a) the washing drum (4) is rotationally driven about its axis of rotation (3); b) the circulation pump (5) is operated in order to pump liquid in the suds container (2) onto the textiles (6) until the information captured by the filling level sensor device (7) indicates that the fill level of the suds container (2) corresponds to a previously defined value; c) after the fill level has reached the defined value, the circulation pump (5) is switched off while the washing drum (4) continues to be rotated, whereby liquid is expelled from the textiles (8) and collects in the suds container (2); d) information relating to the fill level of the suds container (2) is captured by means of the filling level sensor device (7) and is transmitted to the control device (9); e) the information is processed by means of the control device (9) in such a way that a volume of expelled liquid, which is determined on the basis of at least one fill level, is divided by a duration of an expulsion period, whereby a volume flow of the expelled liquid averaged over the expulsion period is determined.

17. Washing machine (1) according to claim 16, characterised by at least one inlet sensor (10) for capturing information relating to a quantity of liquid introduced into the suds container (2).

18. Washing machine (1) according to claim 16 or 17, characterised in that at least one level sensor (8) of the filling level sensor device (7) is arranged at a vertically measured distance from a base (13) of the suds container (2).

19. Washing machine (1) according to any of claims 16 to 18, characterised in that the filling level sensor device (7) comprises a plurality of level sensors (8) which are arranged at different vertically measured distances from a base (13) of the suds container (2).

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