METHOD FOR OPERATING A WASHING MACHINE AND WASHING MACHINE

Description

[0001] The invention relates to a method for operating a washing machine and a washing machine designed to carry out the method. In particular, the method is intended to enable the determination of a type of laundry or fiber type primarily or exclusively in the washing machine, so that a washing program can be adapted accordingly in various advantageous ways.

[0002] It is known from EP 3144425 A1 to monitor humidity and / or temperature profiles during the drying of laundry in a tumble dryer. From these profiles and by comparing an actually recorded profile with profiles stored in a tumble dryer control system for different fiber types, the specific fiber type predominantly or exclusively present in the laundry can then be determined.

[0003] EP 3608466 A1 discloses determining the fiber type of laundry in a tumble dryer by monitoring the behavior of swirling laundry as the dryer rotates. Here, too, a comparison is made between an actually measured curve or a number of curves and stored curves in a tumble dryer control system.

[0004] WO 92 / 09017 A1 discloses a washing machine having a rotatable drum for washing laundry. It includes a water supply system with an inlet device for the drum, water lines, a temperature sensor, a heating device, and a pump. For washing laundry, a predefined amount of water, assuming a known weight of dry laundry, is heated to a predefined temperature by the heating device and then applied to the laundry.

[0005] US 2018 / 0080164 A1 discloses another washing machine with a drum that rotates around a vertical or horizontal axis. A sensor device can detect the volume of dry laundry on the one hand and wet laundry on the other. This allows for better control of the washing process for better washing results. The laundry volume is detected using a distance sensor, which can also detect excessive water levels or excessive foam formation in the drum.

[0006] EP 1 870 504 B1 discloses another washing machine and washing method. Various sensors are provided to determine, among other things, the amount of laundry and the water temperature. This allows the laundry to be washed particularly gently and carefully. Task and solution

[0007] The invention is based on the object of creating a method as mentioned above and a washing machine designed to carry out this method, with which problems of the prior art can be solved and, in particular, it is possible to determine the fiber type of laundry in the washing machine and to be washed. This then forms the basis for a coordinated, optimized washing process or program.

[0008] This object is achieved by a method having the features of claim 1 and by a washing machine having the features of claim 12. Advantageous and preferred embodiments of the invention are the subject of the further claims and are explained in more detail below. Some of the features are described only for the method or only for the washing machine. However, they are intended to be able to apply independently and independently of one another both to the method and to a corresponding washing machine for its implementation. The wording of the claims is incorporated into the description by express reference.

[0009] The washing machine has a rotatable drum with a drum drive that can rotate the drum as required. The drum is permeable to water or has a water-permeable wall and has a drum container in which the drum is arranged, so that the drum container surrounds the drum. Such a drum is usually perforated or provided with openings on the outer circumference and may be provided with drivers or the like on the inside. The drum container is not rotatable and surrounds the drum, being essentially leak-proof. It can have a conventional sump in the lower area, but can advantageously also be designed without a sump. Furthermore, an inlet device is provided for bringing water into the drum onto the laundry contained therein. It is advantageous to have a so-called recirculation washing machine, in which water is not simply allowed into the drum container, so that the water level in the drum also rises accordingly.Rather, the inlet device applies the water directly to the laundry in the drum, for example by means of injection nozzles or spray devices. These can be rigid or alternatively have a controllable direction for the targeted application of the water to the laundry, as is known, for example, from EP 3777639 A1. Furthermore, at least one temperature sensor is provided, which can be arranged on the drum container, advantageously on the outside, or alternatively a temperature sensor on a water pipe, possibly behind the drum container. It should detect the temperature in this area as accurately as possible, in particular of water that impacts the drum container or is located there. Advantageously, several temperature sensors are provided, which will be explained in more detail below.

[0010] Furthermore, at least one pump and water lines are provided to pump water into the washing machine and, in particular, to the inlet device. A conventional and advantageous pump can be used for this purpose. This will be explained in more detail below. The water lines can be rigid or flexible, i.e., they can comprise both rigid pipes and flexible hoses. Furthermore, valves are advantageously provided to control water flow.

[0011] A heating device for heating water in the washing machine is provided so that a suitable and optimal water temperature can be set depending on the selected process or washing program. Furthermore, the heating device is also used for the method according to the invention, as explained in more detail below. The washing machine also has a washing machine control system, which is connected to the temperature sensor, the pump, the heating device, and the drum drive. This washing machine control system advantageously controls all processes in the washing machine, for example also dosing of detergent, and thus also carries out the method according to the invention. It can also be connected to the aforementioned valves in the washing machine to control them to set a desired water flow.

[0012] According to the invention, the following steps are carried out in the method. Initially, dry laundry is placed in the drum or is already in it. Dry laundry is advantageously understood to mean laundry that is completely dry or contains no residual moisture. In particular, it is laundry that is as dry as if it had been dried for such a long time at normal humidity, advantageously 30% to 70% or 40% to 60%, in a living room or laundry room, that its dryness or moisture content no longer changes. This defined state of the laundry is advantageously used to establish defined starting conditions.

[0013] In a further step, the weight of the laundry in the drum is determined or is known, or the result ensures that the washing machine control system knows the weight of this dry laundry. Methods for this are known. Under certain circumstances, a user can also enter it manually. This is also considered important in order to have defined and known conditions for implementing the method according to the invention. The method should be capable of being carried out for different quantities or weights of laundry.

[0014] In a subsequent step, the laundry in the drum is moistened. This is preferably done with a defined amount of water or up to a defined degree of moistening. This can possibly be related to and dependent on the weight of the laundry, for example a proportional amount of water. The ratio can be 1:3, i.e. 1 kg of water for 3 kg of laundry. Alternatively, it can be a certain predefined value of a physical parameter, for example a certain electrical conductivity of the moistened laundry. A degree of moistening can, for example, be such that after a water level has been set in the lower area of ​​the drum container in a subsequent step, which is done by pumping out, water has dripped out of the laundry for a predefined period of time, for example 1 min to 10 min.By pumping out water from the bottom of the drum container in such a way that the drum and therefore the laundry it contains are no longer submerged in standing water, advantageously by completely emptying the lower section of the drum container, the amount of water in the washing machine can be set or reduced to a relatively precisely known or defined amount. The emptying of the drum container can be detected, for example, by the pump's operating behavior, or alternatively it can be recorded by water or fill level sensors. This means that a amount of water remains in the laundry as moisture, which does not drip out so easily or is initially stored by the laundry. This amount of water in the laundry depends on the type of fiber being used; it is relatively high for cotton and relatively low for synthetic fibers.

[0015] In a subsequent step, a predefined amount of water is brought to a predefined temperature by means of the heating device. The pump is advantageously used for this purpose; for example, it can pump this amount of water several times through the heating device or past the heating device for heating, for example in a circulating or oscillating manner, or rocking back and forth. Once the predefined amount of water has reached the predefined temperature, which can advantageously be monitored and detected by a corresponding temperature sensor, it is applied to the laundry in the drum by means of the pump through the water pipes and through the inlet device. From this point on, a temperature is recorded by the temperature sensor arranged on the drum container, and advantageously by all temperature sensors arranged on the drum container or the water pipes. The measured temperatures orTemperature curves are monitored and recorded by the washing machine control system, and if necessary recorded or stored.

[0016] The heated water, which has been drawn into the drum and onto the laundry by the inlet device, flows out of the laundry immediately or quickly, in particular within a maximum of 5 to 10 seconds, and then collects at the bottom of the drum container. From there, it is pumped out of the drum container by the pump. Preferably, the water is pumped out continuously after the pump has pumped the predefined amount of water at the predefined temperature into the drum. Once the pump has pumped water out of the bottom of the drum container, this water is no longer heated. However, this water can then be drawn directly back into the drum and onto the laundry inside by the pump via the inlet device.This previously described step is either carried out at least once, preferably at least two to five times, or it is carried out until a total of at least two to five times the predefined amount of water has been pumped out of the drum container by the pump and applied back to the laundry. The heated water therefore circulates in the washing machine through the drum and through the laundry therein. In other words, a predefined amount of water is heated to a predefined temperature and then applied to the moistened or thoroughly damp laundry. After this, no further heating takes place; instead, this amount of water at the defined temperature circulates multiple times, so to speak, or passes through the washing machine and the laundry multiple times.The water is advantageously introduced into the drum by means of the inlet device in such a way that it always hits the laundry first, runs through it or penetrates it, and only then collects at the bottom of the drum container. During this entire process, at least one temperature sensor on the drum container, and in particular all of the temperature sensors, record the temperature profile. This makes it possible to record, in particular, how this temperature changes predictably, and qualitatively. This is primarily due to the fact that the damp laundry, due to its heat capacity and its lower temperature than the water, draws heat from the water. The pump, the water pipes, the drum container and the drum itself can also draw heat from the water, which also happens. However, these influences are known because they are always the same for one and the same washing machine.In particular, they are each identical in terms of design. Since this can either be calculated out or is no longer noticeable in recorded curves for different fiber types in the laundry due to the constant influence, this principle can be used to determine the main or sole fiber type of laundry in the washing machine. The heat capacity of dry laundry does depend on the fiber type used. Very roughly and generally speaking, laundry has a heat capacity of around 1.5 to 2.5 kJ / kgK, so this difference is not that great. Cotton is towards the lower end, linen towards the upper end, and synthetic fibers such as polyester, polyamide and polyacrylic are in between. Water, however, has a significantly higher heat capacity of 4.18 kJ / kgK, i.e. about twice as high. The method is carried out with damp laundry, namely with laundry that is defined and known to be damp or thoroughly damp.

[0017] This is how the heat capacity of damp laundry is determined, and this depends more on the amount of water stored than on the type of fiber used, i.e. the laundry itself. And here it should be noted that cotton stores considerably more water than the other fiber types. Damp cotton laundry therefore has a relatively high heat capacity for laundry. The aforementioned synthetic fibers store very little water. Damp synthetic fiber laundry therefore has a relatively low heat capacity for laundry. This can be detected with the invention. Depending on the existing heat capacity of the damp laundry in the drum, heat is extracted from the defined amount of water added, and thus its temperature drops from the initially defined temperature. If the temperature drops quickly and for a longer period of time, the laundry has a high heat capacity and is therefore more likely to be cotton.If the temperature drops slowly and for a shorter period of time, the laundry has a low heat capacity and is therefore more likely to be made of synthetic fibers. If a defined amount of warm water is applied to the damp laundry several times or over a certain period of time, the temperature of the water coming out of this damp laundry can be measured and this temperature will rise. The temperature will rise from room temperature or from the temperature of the damp laundry before the warm water is applied, because the relatively colder laundry initially draws a lot of heat from the relatively warm water supplied. The temperature then rises to a maximum value, although it cannot rise higher than the initial defined temperature to which the predefined amount of water was heated.

[0018] The next step is to determine, based on the detected and recorded temperature profiles of the at least one temperature sensor on the drum container, which fiber type the laundry in the drum predominantly or exclusively contains. For this purpose, the washing machine control system has a memory in which temperature profiles for temperatures at the at least one temperature sensor are stored, which were recorded when carrying out the method according to the aforementioned steps with the same predefined amount of water and the same predefined water temperature. These stored temperature profiles do not necessarily have to have been carried out specifically with this washing machine. It is sufficient if they are detected as examples based on the type or design and then stored in the aforementioned memories. The temperature profiles are divided into groups or grouped together.Several groups of temperature profiles for different weights of dry laundry have been saved as a single parameter. This is considered necessary and advantageous in order to be able to measure the temperature as accurately as possible depending on the weight of the laundry present, for example, in 100-gram or 500-gram increments. Finally, the total heat capacity and water absorption capacity of the laundry in the drum also depend heavily on the amount of laundry, i.e., its weight. The minimum weight can be 1 kg or even just 0.5 kg. The maximum weight can be between 5 kg and 7 kg, depending on the drum capacity.

[0019] A further grouping of the temperature profiles is a subdivision of the stored temperature profiles into subgroups for at least two different fiber types of the laundry. These at least two different fiber types are synthetic fiber or polyester on the one hand, and cotton on the other. These are the most commonly used fiber types. Advantageously, further fiber types can be provided for subdivision, for example polyamide, polyacrylic, linen, silk or wool. For these subgroups, each with the same fiber type of laundry, the process is carried out exactly as before for the different weights, and the temperature profiles are recorded or captured and saved at the at least one temperature sensor on the drum container, preferably at all temperature sensors on the drum container.

[0020] A multitude of known temperature profiles are stored in the memory. In a further step, the washing machine control then compares the temperature profile recorded for at least one temperature sensor with all stored temperature profiles. Naturally, based on the known weight of the dry laundry in the washing machine from the first process step, the group of temperature profiles corresponding to the weight is examined. This occurs in the final step, and there, in the corresponding group of the same weight, the stored temperature profile is selected that most closely matches or best matches the recorded temperature profile, or is identical to it.From this, the washing machine control system, designed for this purpose, can then conclude that the primary or sole fiber type underlying the stored temperature profile also applies to the laundry in the drum in this case. The laundry is thus defined by the primary or sole fiber type of this matching or corresponding temperature profile.

[0021] In highly simplified terms, the invention involves moistening laundry in the drum with a defined amount of water, with the degree of moistening varying depending on the fiber type of the laundry. A predefined amount of water is then applied to the laundry at a predefined temperature. The washing machine's control system can determine the fiber type of the laundry based on how quickly and how much heat is extracted from this amount of water. The temperatures are measured using temperature sensors on the drum container.

[0022] The method can advantageously take into account the fact that laundry made from more than one fiber type is often not meant to be washed together. The laundry can either be a blend of different fiber types or, alternatively, items of laundry that each consist exclusively of one fiber type but have different fiber types can be placed in the drum together. This allows for a further subdivision of the stored temperature profiles, and therefore also for their recording, into different distributions of the proportions between two or more different fiber types. This is advantageously done for different proportions of cotton on the one hand and polyester, polyamide, or synthetic fiber on the other.For example, these proportions can vary in 10% increments, starting with 10% cotton and 90% polyester / polyamide and ending with 90% cotton and 10% polyester / polyamide. Admittedly, it is not very likely that a temperature profile actually recorded and stored during the process can be precisely assigned to a single stored temperature profile, so that the laundry in the drum actually contains only this fiber or this distribution of fiber types. However, an approximate assignment, especially when several fiber types are present, is possible and is considered sufficient.

[0023] In a further embodiment of the invention, the predefined water quantity, and possibly also the predefined water temperature, is adapted to the determined weight of the dry laundry at the start of the process; in fact, it can be selected differently in each case. At least for the predefined water quantity, it can advantageously be greater the higher the determined weight of the dry laundry in the drum, i.e. the more laundry there is. This can advantageously be proportional and not just more water for more laundry and less water for less laundry. For example, the predefined water quantity can be between 20% and 100% of the weight of the dry laundry, particularly advantageously between 30% and 70%.

[0024] In an advantageous embodiment of the invention, two temperature sensors are provided, preferably on the drum container and arranged at different heights, i.e. at different vertical heights. These two temperature sensors can be arranged along a water line and / or on the drum container. In an advantageous embodiment of the invention, two temperature sensors are arranged at different heights on the drum container, and each of them produces its own temperature profile, which is recorded. By differentiating according to vertical height, a better distinction can be made between the fiber types of the laundry, possibly depending on the weight of the laundry. By means of a temperature sensor on the water line behind the drum container, the water temperature can be monitored at an even further location and, advantageously, a temperature profile can also be recorded and recorded.

[0025] A predefined water quantity can be between 0.2 and 5 liters, but preferably between 0.5 and 2 liters or between 0.75 and 1.25 liters. Such water quantities can be easily heated to the predefined water temperature in the washing machine before the water is applied to the laundry. Alternatively, the water quantity can be determined proportionally to the weight of the dry laundry, for example, between 20% and 100%, preferably between 50% and 90%.

[0026] The predefined temperature can be between 25°C and 70°C, but preferably between 30°C and 40°C, or even up to 45°C. This avoids very high temperatures that could potentially damage certain fiber types, as the fiber type is unknown at the beginning of the process. Furthermore, the higher the temperature, the higher the energy consumption. After all, heating to higher temperatures also takes longer than heating to lower temperatures.

[0027] In an embodiment of the invention, it can be provided that the complete pumping of the predefined amount of water from the drum or from the drum container through the pump and back into the drum takes 1 to 10 seconds, preferably 2 to 5 seconds. This is then essentially the circulation time of a water molecule. By pumping relatively quickly, the heat loss from the heated water to the water pipes or other parts of the washing machine can be reduced. The influence of the laundry itself on the water temperature, or its changes, then increases, which is desirable for increased accuracy.

[0028] In an advantageous development of the invention, the drum is rotated at least temporarily, in particular continuously, during the process, in particular while the heated water is applied to the laundry and especially subsequently. The rotation speed can be from 50 to 1,800 revolutions per minute or a maximum rotation speed of the washing machine. A medium or rather low rotation speed is advantageously selected, in particular from 400 to 800 revolutions per minute. In this case, an embodiment of the invention can provide that the drum is rotated so quickly that, on the one hand, the laundry is distributed around the drum due to centrifugal force. Advantageously, the laundry is evenly distributed.Secondly, the drum's rotation speed can be selected so that the water applied to the laundry doesn't flow downwards inside the drum and only through the laundry at the bottom into the drum container, but rather flows outward through the laundry through radial rotation, thus also due to centrifugal force. This allows as much water as possible to reach all areas of the drum container and thus also all the temperature sensors provided there for accurate temperature measurement.

[0029] Preferably, during the aforementioned pumping, the water is continuously circulated or pumped during the process, in particular with the pump output as consistent as possible. The amount of water applied to the laundry through the inlet device may be somewhat lower during the further course of the process than when the predefined amount of water at the predefined temperature is initially applied. However, it should at least remain as constant as possible thereafter. The pumped amount of water can advantageously be recorded at the pump itself, preferably based on its operating data. This is known from the prior art.

[0030] In a further embodiment of the invention, there should be no warm water in the drum container before the predefined amount of water with the predefined temperature is introduced, and in particular no water at all if possible. For example, a sump formed at the bottom of the drum container should be as empty as possible. If water has run out and collected here when the laundry was moistened, it should be removed. In this way, any distorting influence on the process from water still in the system, which has a very high heat capacity, can be reduced or completely avoided. This would be detrimental because its amount and temperature are unknown and are not related to the fiber type of the laundry. The amount of water in the laundry should be characteristic of the fiber type of the laundry, and any excess water should be removed.

[0031] In an advantageous embodiment of the invention, it can be provided that, in order to heat the predefined amount of water to the predefined temperature, the pump pumps the corresponding amount of water through the heating device several times, without reaching the inlet device or the drum container. Thus, the entire amount of water does not have to be heated in one location or in one container, for example, similar to a heatable water tank, although this is also possible. Instead, the water can be pumped by the pump either in a circulating manner or with alternating flow direction through or past the heating device, depending on what results in heating.Preferably, the water can be circulated along a type of circulating water line, which is either already provided and necessary for the washing machine's operation, or which is at least partially dedicated to this purpose and can, for example, be enlarged. This allows the water to be heated slightly more each time it flows through or past the heating device. If this is a closed water circuit, so to speak, then the full heating power can be permanently applied to the predefined amount of water.

[0032] With a changing flow direction of the predefined amount of water through the heating device, a water tank can be provided in the washing machine, which is advantageously thermally insulated and which is designed so that the pump pumps water into and out of it when heating the predefined amount of water to the predefined temperature. The water flows past the heating device at least once, advantageously both times. So here too, water is heated almost most of the time, if not all of the time, by means of the heating device. By means of an appropriately cleverly arranged temperature sensor, advantageously on the pump, on the heating device, on a water pipe, or on the aforementioned water tank, the temperature profile and, in particular, the attainment of the predefined temperature can be precisely monitored.This allows water to be rocked back and forth, advantageously even flowing through the pump. If the pump is designed as an impeller pump, it cannot pump in both directions, except by using multiple valves to direct the water flow in the same direction through the pump, but in a different direction through the water pipes. However, if the pump pumps the water into a higher section of a water pipe or a water tank and then stops pumping, the water can flow back through the pump automatically. This is described in DE 102020213968.7, filed on November 6, 2020, by the same applicant, which is hereby incorporated by reference.

[0033] The water tank holds at least half of the predefined water volume or the maximum predefined water volume. The remainder can be stored in the water pipes. Advantageously, the water tank holds the predefined water volume or the entire maximum water volume. This allows for maximum heating of this water volume to the predefined temperature through continuous or frequent pumping with simultaneous heating.

[0034] In an advantageous embodiment of the invention, a temperature sensor can be arranged on the pump and / or on the heating device. This can be used to detect the temperature of the water flowing through or being pumped through. The washing machine control system can then calculate the heating energy previously expended or introduced into the water as the heating power times the heating time. A temperature sensor can, for example, be integrated into the pump and / or the heating device, for example, as an integral part thereof. A temperature sensor can be provided specifically for one of the heating devices as a protective mechanism to protect it from overheating.This temperature sensor can also be used to detect and record a temperature and then compare it with a stored temperature profile, similar to what was described at the beginning for the at least one temperature sensor that can be arranged on the drum container.

[0035] In an advantageous embodiment of the invention, the heating device, in particular including the temperature sensor, is integrated into the pump. Such a pump with an integrated heating device is known, for example, from DE 102013211180 A1, to which explicit reference is hereby made.

[0036] In a further advantageous embodiment of the invention, it can be provided that the aforementioned temperature sensor on the drum container is arranged as a first temperature sensor in the height range of the lower half of the drum container on the outside thereof. A further temperature sensor is arranged as a second temperature sensor at the vertical height of the upper half of the drum container and on the outside thereof. Advantageously, the lower first temperature sensor is arranged at at least 10% of the vertical height of the drum container above its lowest point, preferably 20% to 40% of its height. The upper second temperature sensor can be arranged at the corresponding vertical height, namely 60% to 80% or even 90% of the vertical height of the drum container.

[0037] Another temperature sensor is advantageously located on a water line leading to the inlet device and upstream of it in the direction of flow. This allows the water temperature to be recorded and possibly checked before it is applied to the laundry via the inlet device. The distance between the temperature sensor and the inlet device is advantageously less than 10 cm or even less than 5 cm. At this short distance, a significant or noticeable temperature drop as the water flows through is unlikely.

[0038] This procedure can be performed primarily to check whether a washing machine program set by a user is suitable for the actual laundry or fiber type. For example, if a high-temperature program is set because the user assumes the laundry is cotton, but the washing machine detects that the laundry consists primarily or entirely of synthetic fibers or delicate wool, the washing machine can issue an error message or warning. Alternatively, it can automatically reduce the temperature to avoid damaging the synthetic or woolen laundry.

[0039] These and other features emerge not only from the claims but also from the description and the drawings. The individual features may be implemented individually or in combination in one embodiment of the invention and in other fields, and may represent advantageous and protectable embodiments for which protection is claimed here. The division of the application into individual sections and subheadings does not limit the generality of the statements made therein. Brief description of the drawings

[0040] Embodiments of the invention are illustrated schematically in the drawings and explained in more detail below. The drawings show: Fig. 1 a simplified schematic representation of a washing machine according to the invention with a water guide and several temperature sensors, Fig. 2 the washing machine from Fig. 1during the implementation of the method according to the invention with application of water to the laundry in a drum, Fig. 3 shows temperature profiles at the temperature sensors for cotton and Fig. 4 shows the temperature profiles at the temperature sensors for synthetic fiber. Detailed description of the implementation examples

[0041] In the Fig. 11 shows a washing machine 11 according to the invention with a rotatable drum 13 in which laundry W is present, here shown as individual items of laundry W. Drivers 14 are arranged on the inside of the drum. The drum 13 has a water-permeable outer wall, advantageously perforated as usual, and is rotatably mounted in a drum receiving container 15, here with a horizontal axis of rotation. At the bottom of the drum receiving container 15, a sump line 17 leads from an outlet 16 as a water line via a valve V1 to a water reservoir 20. From this water reservoir 20, a further pump line 22a leads to a pump 24. This pump 24 is designed as explained in the prior art mentioned at the outset, for example according to DE 102011003467 A1, advantageously as an impeller pump. It has an integrated heating device 25, which is shown very schematically here.The heating device 25 serves to heat water pumped by the pump, in particular in the pump chamber, for which purpose it is advantageously arranged in the pump chamber itself or adjacent to a wall of the pump chamber.

[0042] Another pump line 22b leads from the pump 24 to a three-way valve, designated as pump valve V2. In one valve position, water can flow from the pump 24 or pump line 22b to a water outlet 27 leading out of the washing machine 11. Water can thus be removed or drained from the washing machine 11 via the water outlet 27.

[0043] In another position of the pump valve V2, water flows from the pump line 22b via a supply line 29 to an injection nozzle 31, the aforementioned inlet device, with a certain pressure for the water. The injection nozzle 31 is located at the highest point of the drum receiving container 15 and is designed such that, although it does not extend directly into the rotatable drum 13, it can apply, spray, or inject water F onto the laundry W arranged therein through openings provided therein in a known manner. Reference is made to the prior art, which illustrates this sufficiently well.

[0044] A detergent container 33 is arranged at the top left of the drum receiving container 15, from which detergent or other additives for a washing process can be introduced into the drum receiving container 15 or onto the laundry W in the drum 13 by means of a water line 34 and a dosing valve V3, alternatively also by means of a nozzle (not shown). In yet another alternative, which will be discussed below, Fig. 4 As explained, detergent can be introduced either into the lowest area of ​​the drum receptacle 15 just before the outlet 16 or into the sump line 17 so that it first mixes with or dissolves in the water before being applied to the laundry W. A motor 40 is provided as a drum drive for the drum 13 by means of a drive belt 41, as is known per se. The motor 40 can be controlled as desired.

[0045] In the Fig. 1It is also shown how a first temperature sensor 35 is arranged on the outside right and in the lower area on the outside of the drum container 15. The first temperature sensor 35 is advantageously a conventional temperature sensor with temperature-dependent electrical resistance, for example a PTC, an NTC or a PT100 / PT1000, which can measure very quickly and very accurately in the temperature range discussed here. It is advantageously connected to the drum container 15 in a way that conducts heat well. It can be arranged at a height of approximately 20% of the total height of the drum container 14 or the vertical height between the outlet 16 and the highest point on the injection nozzle 31. Viewed from the side, it can be arranged in a central area between the front and rear.

[0046] Furthermore, slightly above the first temperature sensor 35, a second temperature sensor 36 is attached to the outside of the drum container 15 in the same manner. The second temperature sensor 36 is advantageously identical to the first temperature sensor 35. It is located at approximately 80% of the vertical height of the drum container 15. Viewed from the side, it can also be located in a central area between the front and rear. However, one of the two temperature sensors would also be sufficient.

[0047] A third temperature sensor 38, which is advantageously also identical to the other two, is additionally arranged on the supply line 29 just before the injection nozzle 31. It serves to measure the temperature of the water introduced directly behind it via the injection nozzle 31. This can also be done in the pump.

[0048] The three temperature sensors 35, 36, and 38 are connected to a washing machine control unit 39, as are the pump 24, the heating device 25, the temperature sensor 26, and the motor 40. This connection is also shown for the first temperature sensor 35, but not for the others for the sake of clarity. The washing machine control unit 39 can thus measure and record the water temperature at the respective point using the aforementioned temperature sensors 35, 36, and 38, as well as the temperature sensor 26, and possibly also store it. The washing machine control unit 39 advantageously also has a memory for the aforementioned profiles, as described above but not shown here.

[0049] In order to carry out the method according to the invention as described in Fig. 2As shown, laundry W in a dry state, for example 3 kg of laundry, is first placed into the drum 13 according to the definition mentioned at the beginning. The known weight is either manually entered by a user into the washing machine control 39 or it is determined beforehand by the washing machine control 39 of the washing machine 11 itself in a manner known from the prior art, for example when the drum 13 is rotated quickly. The laundry is then moistened with, for example, 1 l or 2 l of water. This can, for example, run via a supply line through the detergent container 33 and the dosing valve V3 first into the drum 13 and then be pumped out by the pump 24 and distributed onto the laundry W by means of the injection nozzle 31 so that it is absorbed into the laundry. This can be done until the pump 24 can no longer suck in any more water.The drawing-in process can be assisted by slow or intermittent rotation of the drum 13 by means of the motor 40. With the stated quantity of 3 kg of laundry, 1 liter of water will most likely be completely absorbed, and only a little or none of it will run out of the laundry W. Thus, the washing machine control system 39 knows the weight of previously dry laundry in the drum 13 and the amount of water that has been added to moisten it. The defined quantity of 1 liter of water can be adjusted so that it is completely absorbed by 3 kg of dry cotton laundry. With more or less laundry, this amount of water for moistening could then be greater or lesser.With 3 kg of synthetic laundry, it may not be able to fully absorb this defined amount of 1 liter of water, and thus some of the water will leak out, collect at the bottom of the drum, and then drain out or be pumped out. This otherwise identical amount of synthetic laundry can then retain less water and thus has a lower heat capacity when fully damp. The heat capacity when fully damp depends on the type of fiber in the laundry. If the heat capacity can be determined, at least qualitatively, then one can deduce the type of fiber.

[0050] The temperature of this water for wetting is preferably room temperature, i.e., approximately 22°C. This room temperature can also be determined by the washing machine control system 39 itself using its own temperature sensors, alternatively, for example, using the third temperature sensor 38 located just before the injection nozzle 31. Thus, the washing machine control system 39 knows the heat capacity present in the drum 13; only the fiber type of the laundry W is unknown.

[0051] The predefined amount of water for a burst of warm water, here for example 1 l, is then brought to a predefined temperature, here for example a particularly high temperature for illustration purposes, namely 60°C. In practice, the process is advantageously carried out at the aforementioned lower temperatures, since otherwise it would not be possible to avoid damaging sensitive fiber types as subgroups due to excessively high temperatures. Even at these lower temperatures, the temperature profiles differ sufficiently. On the one hand, water can be completely sucked out of the drum container 15 via the outlet 16 and the sump line 17 through the outlet valve V1. If necessary, additional water can be admitted, for example again at the top via a supply line through the detergent container 33 and the dosing valve V3. The aforementioned water quantity of 1 l can, for example, easily be absorbed in the water reservoir 20.By means of the pump 24, water can be sucked from the water reservoir 20 and pumped further or upwards into the pump line 22b and also into the adjoining supply line 29. The heating device 25 is operated and heats this water; the temperature of this water can advantageously be detected via a temperature sensor arranged in the pump 24, which is also arranged, for example, on the heating device 25, and / or via the temperature sensor 26 shortly after the pump 24. The pumping operation is then stopped, and the water pumped upwards in the lines 22b and 29 can flow back through the pump 24 into the water reservoir 20. In the process, it can possibly be heated again by the heating device 25. This process can be repeated several times until the desired temperature of 60°C is reached.This represents a simple way of bringing a larger, predefined amount of water to a predefined temperature using the pump 24 and the heating device 25 attached to it, which are actually designed for multiple-pass heating. Alternatively, a heating device could, of course, also be arranged on the water reservoir 20 to bring the predefined amount of water therein, and in a quasi-static state, to the predefined temperature. This could, in turn, be monitored by a temperature sensor.

[0052] Then, the drum 13 with the laundry W inside is set in rotation and at the same time, the pump 24 pumps the predefined amount of water at the predefined temperature through the pump line 22b and the supply line 29 by means of the injection nozzle 31 into the drum 13 and onto the laundry W therein. The rotational speed can be, for example, 600 or 800 revolutions per minute. This ensures that the laundry W is evenly applied to the inside of the drum 13. Furthermore, water striking the laundry W from the inside is forced through the laundry W and can escape through the water-permeable wall of the drum 13. The pumping and application of the water should be relatively strong or sudden, i.e., quick. Fig. 2it can be seen how water F, which has previously passed through the laundry W, flows downwards at various points in the drum container 15 towards the outlet 16. The system, including the lines, should be designed such that the water reservoir 20 is empty when water that has just been applied flows in from above through the outlet 16 and the sump line 17. This water can then be immediately applied to the laundry W by the continuously operated pump 24, but this time without heating, via the pump line 22b and the feed line 29 by means of the injection nozzle 31. This takes place for a duration of, for example, 6 to 10 seconds, because it takes that long to apply the predefined amount of water to the laundry W through the injection nozzle 31. The water can then either be collected again and first heated up to the predefined temperature in accordance with the predefined amount of water.This heated amount of water can then be applied again. Alternatively, water F immediately running off the laundry W can be collected again and applied to the laundry W again by the pump 24, which can then be done several times, for example two to five times. Thus, a total of between 2 l and 5 l would have been applied to the laundry W by means of the injection nozzle 31, but always only the same predefined water quantity of 1 l. This water quantity is also not heated again. In principle, however, it may also be sufficient to apply the defined heated and predefined amount of water to the laundry just once and then record the resulting temperature curves.

[0053] It is important that the three temperature sensors 35, 36 and 38 measure the temperature of the water at them. For the first alternative, Fig. 3The diagram shows, over time t, how the predefined water quantity of 1 liter with the predefined temperature of 60°C is introduced into the system of the drum container 15, the drum 13, the moistened laundry W and the lines including pump 24, i.e. how it is pumped from the pump 24 into the pump line 22b, in the course with diamonds. Thus, at a time t = 5 seconds, water with a temperature of 60°C is suddenly in this system, and this temperature remains until t = 12 seconds. Then the pump 24 stops operating for a few seconds. The course with the diamonds essentially represents the temperature course at sensor 26. The laundry W here has the fiber type of the subgroup cotton.

[0054] Also shown are the temperature curves at the three temperature sensors 35, 36, and 38. The temperature rise is predictably fastest and highest at the third sensor 38, at the very top of the injection nozzle 31, because this is where the warm water flow, corresponding to the predefined water volume and temperature, arrives first, virtually without cooling. This temperature curve, represented by the triangles, rises very quickly to the same temperature of 60°C, corresponding to the temperature of the predefined water volume. If no further water is pumped in, the temperature remains high as long as there is a water flow.

[0055] The temperature curve at the second upper temperature sensor 36 with the squares rises somewhat more slowly and only to approximately 50°C. This water must first pass through the damp laundry W due to the rotation of the drum 13 before being spun into the drum container 15 in the area of ​​the second temperature sensor 36. This water therefore first transfers some of its heat energy to the damp and colder laundry, and the temperature rises more slowly.

[0056] What's even clearer is the temperature curve marked with crosses at the first temperature sensor 35: it is even more delayed or slowed down, reaching a maximum temperature of only about 30°C. Here, it simply takes longer for the water, which first hits the inside of the drum container 15 at sensor 36, to flow downwards and past the first temperature sensor 35. Furthermore, this water has already transferred more of its heat to the drum container 15, which is why a significantly lower temperature is recorded there overall.

[0057] The temperature trends according to Fig. 3On the one hand, the delays and also the absolute heights naturally depend on the structural design of the washing machine 11, especially with regard to the lines 22b and 29, the injection nozzle 31 as well as the drum container 15 and the drum 13. These conditions are always the same for this washing machine 11 or its type, i.e. other identically constructed washing machines, regardless of the fiber type of the laundry W contained therein. Additional differences between the curves for these temperatures, in particular at the first sensor 35 and the second sensor 36, are therefore only due to the type of laundry itself. For this reason, it is also advantageous if, when the amount of laundry is known, an appropriate amount of water is added in order to moisten the laundry according to the invention before the actual process of recording the temperatures begins.

[0058] In Fig. 4 the temperature curves are accordingly Fig.3for laundry W of the same quantity made of synthetic fiber. The laundry W here therefore has the subgroup synthetic fiber as its fiber type. The temperature curve with the diamonds up to 60°C naturally remains the same. The fastest and highest temperature rise is again predictably at the third temperature sensor 38 at the very top of the injection nozzle 31. This temperature curve with the triangles rises even faster here to the same temperature of 60°C, corresponding to the temperature of the predefined water quantity.

[0059] The temperature curve at the second upper temperature sensor 36 with the squares increases somewhat more slowly than at the third temperature sensor 38, but significantly faster than in Fig. 3. Furthermore, the temperature rises to approximately 55°C. This is even more evident in the temperature curve marked with crosses at the first temperature sensor 35. Although it rises faster here than before, it reaches a maximum temperature of approximately 38°C.

[0060] Since the washing machine control system 39 controls the entire process, in particular also the pump 24, it knows when temperature changes are to be expected at which temperature sensors 35, 36 and 38, and possibly also 26, so that the temperature can be recorded. The washing machine control system 39 now stores example curves for the temperature profiles at the temperature sensors 35, 36 and 38, and possibly also 26, depending on the amount or weight of dry laundry, the water added for moistening, preferably including its temperature, and above all on the fiber type of the laundry. If the amount or weight of dry laundry is less, the curves for the temperature profiles rise more quickly, possibly even higher, and vice versa. If the fiber type of the laundry is cotton, the curves for the temperature profiles rise more slowly, possibly even less steeply, than with synthetic fibers.Such temperature curves can also be recorded and saved for other frequently used fiber types, varying the aforementioned parameters (amount or weight of dry laundry and the amount of water added for wetting), preferably including the water temperature. Such fiber types can include linen, silk, and wool, as well as possibly various synthetic fibers, as mentioned above.

[0061] Similar methods for using step responses in a system dependent on a heat surge or a sudden increase in temperature are known from DE 102006014515 A1, to which explicit reference is hereby made. There, the temperature in an oven is suddenly increased to determine the humidity inside. This humidity largely determines the heat capacity of the air inside.

Claims

1. Method of operating a washing machine (11), the washing machine (11) comprising: - a rotatable drum (13) having a water permeable wall, and a drum drive (40) for rotating the drum (13), - a drum container (15) in which the drum (13) is located, the drum container (15) surrounding the drum (13), - a inlet device (31) for introducing water (F) into the drum (13) onto laundry (W) located therein, - a pump (24) and water pipes (17, 22a, 22b, 29, 34) for pumping water (F) to the inlet device (31), - at least one temperature sensor (35, 36, 38, 26) on the drum container (15) or on a water pipe (17, 22a, 22b, 29, 34), - a heating device (25) for heating water (F), the heating device (25) being connected to the pump (24) in a water-conducting manner, - a washing machine control (39) which is connected to the temperature sensor (35, 36, 38, 26), the pump (24), the heating device (25) and the drum drive (40), with the following steps: a) dry laundry (W) is in the drum (13), b) the weight of the dry laundry (W) in the drum (13) is known in the washing machine control (39), preferably the weight of the dry laundry (W) in the drum (13) is determined by the washing machine control (39), c) the laundry (W) in the drum (13) is thoroughly moistened, d) a water level in the lower area of the drum container (15) is set by means of the pump (24) so that the drum (13) is not immersed in standing water (F), in particular the drum container (15) is pumped empty, e) a predefined quantity of water is heated to a predefined temperature by means of the heating device (25), f) the predefined quantity of water at the predefined temperature is pumped by means of the pump (24) through the water pipes (17, 22a, 22b, 29) and through the inlet device (31) into the drum (13) onto the laundry (W) therein, g) water is pumped out of the drum container (15) by means of the pump (24) and is applied to the laundry (W) by means of the water pipes (17, 22a, 22b, 29) and the inlet device (31) in the drum (13), h) the above step g) is carried out at least once, preferably at least twice to five times, or is carried out until at least two to five times the predefined amount of water has been pumped out of the drum container (15) and applied to the laundry (W), i) the temperature at the temperature sensor (35, 36, 38, 26) is detected and recorded during the application of the water (F) to the laundry (W), and j) temperature curves for temperatures at the temperature sensor (35, 36, 38, 26) are stored in a memory in the washing machine control (39), which temperature curves were recorded when carrying out the method according to steps a) to i) with the same predefined water quantity and the same predefined water temperature, j1) wherein a plurality of groups of temperature curves have been recorded for different weights of dry laundry (W) in the drum (13), j2) wherein the stored temperature curves are additionally subdivided into subgroups for at least two different types of fiber of the laundry (W), wherein the method according to steps a) to i) has been carried out for the subgroups with the same type of fiber of the laundry (W) in each case, in order to detect and store the temperature curves, k) the washing machine control (39) compares the recorded temperature curves with the stored temperature curves and searches for the greatest match, l) if the weight of the dry laundry (W) corresponds, the washing machine control (39) determines the subgroup of the fibre type of the laundry (W) in the drum (13) in this group on the basis of the greatest correspondence of the recorded temperature curve with the stored temperature curves.

2. Method according to claim 1, characterized in that two temperature sensors (35, 36, 38, 26) are provided and arranged at different vertical heights on the drum container (15), wherein the temperature sensors (35, 36, 38, 26) are arranged on a water conduit (22b, 29) and / or on the drum container (15), with at least one temperature sensor (35, 36, 38) being arranged on the drum container (15), with one temperature sensor (26) preferably being arranged on the water pipe (22b, 29) downstream of the drum (13).

3. Method according to claim 1 or 2, characterized in that the predefined amount of water is 0.5 I to 2 l, in particular 0.75 l to 1.25 l.

4. Method according to one of the preceding claims, characterized in that the predefined temperature is 25°C to 70°C, preferably 30°C to 40°C.

5. Method according to one of the preceding claims, characterized in that a complete pumping of the predefined amount of water from the drum (13) or from the drum container (15) through the pump (24) and back into the drum (13) takes 1 sec to 10 sec, preferably 2 sec to 5 sec.

6. Method according to one of the preceding claims, characterized in that the drum (13) is rotated at least intermittently, in particular permanently, during steps f) to h), preferably at a speed of 50 to 1800 revolutions per minute, in particular 400 to 800 revolutions per minute.

7. Method according to claim 6, characterized in that the drum (13) is rotated so quickly that the water (F) applied to the laundry (W) does not run down within the drum (13) and through the laundry (W) down into the drum container (15), but passes through the laundry (W) in a radial direction outwards due to the rotation, preferably through the wall of the drum (13) to the drum container (15) and to the temperature sensor (35, 36, 38).

8. Method according to one of the preceding claims, characterized in that the water (F) is continuously recirculated by operating the pump (24).

9. Method according to one of the preceding claims, characterized in that, before the introduction of the predefined quantity of water (F) at a predefined temperature via the inlet device (31), there is no water (F) in the drum container (15) below the drum (13), in particular in a sump formed at the bottom of the drum container (15), and preferably not in a water pipe (17, 22a) between the drum container (15) and the pump (24) either.

10. Method according to one of the preceding claims, characterized in that, to heat the predefined quantity of water (F) to the predefined temperature, water (F) corresponding to the predefined quantity is pumped a plurality of times by the pump (24) through the heating device (25) without reaching the inlet device (31) or the drum container (15), either in a circulating manner or with alternating flow direction through the heating device (25), wherein a water container is preferably provided in the washing machine (11), which is in particular thermally insulated, from and into which the pump (24) pumps the water (F) when heating the predefined quantity of water (F) to the predefined temperature and pumps it out again, preferably the water container holding at least half of the predefined quantity of water (F) or at least the predefined quantity of water (F).

11. Method according to one of the preceding claims, characterized in that at least one temperature sensor is arranged on the pump (24) and / or on the heating device (25) to determine the temperature of the water (F) flowing or being pumped through and / or to measure a heating energy used.

12. Washing machine (11) designed to carry out the method according to one of the preceding claims, wherein the washing machine (11) comprises: - a rotatable drum (13) having a water-permeable wall, together with a drum drive (40) for rotating it, - a drum container (15) in which the drum (13) is arranged, the drum container (15) surrounding the drum (13), - an inlet device (31) for introducing water (F) into the drum (13) onto laundry (W) located therein, - a pump (24) and water pipes (17, 22a, 22b, 29, 34) for pumping water (F) to the inlet device (31), - at least one temperature sensor (35, 36, 38, 26) arranged on the drum container (15) or on a water pipe (17, 22a, 22b, 29) downstream of the drum container (15), - a heating device (25) for heating water, the heating device (25) being connected to the pump (24) in a water-conducting manner, - a washing machine control (39) which is connected to the temperature sensor (35, 36, 38, 26), the pump (24), the heating device (25) and the drum drive (40), the washing machine control (39) having the storage tank and being designed to carry out the method according to one of the preceding claims.

13. Washing machine according to claim 12, characterized in that a water container is provided in the washing machine (11), which is in particular thermally insulated, and the pump (24) pumps the water (F) in and out of said container when heating the predefined quantity of water (F) to the predefined temperature, whereby the water container preferably holds at least half of the predefined quantity of water (F), in particular at least the entire predefined quantity of water (F).

14. Washing machine according to claim 12 or 13, characterized in that at least one temperature sensor (35, 36, 38, 26) is arranged on the pump (24) and / or on the heating device (25) for determining the temperature of the water (F) flowing through and / or for detecting a heating energy used.

15. Washing machine according to one of the claims 12 to 14, characterized in that the temperature sensor is arranged as a first temperature sensor (35) at the level of the lower half of the drum container (15) on the outside of the drum container (15) and a further temperature sensor is arranged as a second temperature sensor (36) at the level of the upper half of the drum container (15) on the outside of the drum container (15), wherein the first temperature sensor (35) is preferably arranged at least 10% of the vertical height of the drum container (15) above the lowest point of the drum container (15), in particular a temperature sensor (26) being arranged on a water pipe (29) towards the inlet device (31) and in front of it in the direction of flow, at a distance of less than 10 cm in front of the inlet device (31).