Method, computer program product and dishwasher

Abstract

The invention relates to a method for operating a dishwasher (1), in particular a household dishwasher, which has a control device (15) for carrying out a washing program (SP1, SP1*) from a number of washing programs, wherein a respective washing program (SP1, SP1*) comprises a number of sub-program steps (TP0 - TP4) which are carried out sequentially when carrying out the washing program (SP1, SP1*), wherein at least one specific washing program (SP1, SP1*) of the number comprises a pre-wash sub-program step (TP1) and a subsequent cleaning sub-program step (TP2), the method comprising carrying out the specific washing program (SP1, SP1*), which comprises: in the pre-wash sub-program step (TP1): A) supplying (S1) water into a washing chamber (4) of the dishwasher (1) to provide a washing solution, B) dosing (S2) a predetermined amount of a cleaning agent into the washing solution,C) Circulating (S3) the rinsing liquor and applying the rinsing liquor to the items to be washed arranged in the rinsing chamber (4), wherein a heater for heating the rinsing liquor is inactive during the pre-rinsing (TP1), and in the sub-program step cleaning (TP2): D) Heating (S4) the rinsing liquor to a predetermined temperature (T1), and E) Circulating (S5) the heated rinsing liquor and applying the heated rinsing liquor to the items to be washed arranged in the rinsing chamber (4), wherein no further cleaning agent is added to the rinsing liquor except in step B) during the pre-rinsing (TP1) and the cleaning (TP2).

Description

[0001] The present invention relates to a method for operating a dishwasher, a computer program product and a dishwasher.

[0002] Conventional dishwashers offer users a variety of wash programs for cleaning dishes. These programs are optimized for a specific type of dishware, such as glass, plastic, porcelain, or metal, a specific degree of soiling, or a preferred wash duration. Each wash program typically comprises a number of steps that are performed sequentially. Typically, these include a pre-wash step, a main wash step, a final rinse step, and a drying step. For each of these steps, parameters such as duration, water volume, temperature, and so on can be adjusted.

[0003] EP 3 087 869 A1 discloses a method for washing dishes in a program-controlled dishwasher, in which cleaning, intermediate rinsing and final rinsing are carried out successively as rinsing steps, wherein the cleaning rinsing step begins with a water inlet, followed by a first rinsing phase, a water heating phase and a second rinsing phase, wherein the rinsing duration of the first rinsing phase of the cleaning is selected to be longer than the rinsing duration of the second rinsing phase of the cleaning.

[0004] EP 2 179 684 A1 discloses a dishwasher with a pre-wash option that a user can activate in combination with one of the wash programs. When the pre-wash option is activated, the water temperature and duration of the individual steps of the respective wash program are increased, thereby increasing the cleaning performance.

[0005] WO 2017 / 137072 A1 discloses a dishwasher programmed to perform at least one cleaning phase and then at least one first rinsing phase. A dosing system can be used to introduce a flocculant into the washing liquid, which promotes the formation of flocs from detergent and dirt particles. The dosing system is controlled such that it is activated at least at the end of the cleaning phase, i.e., before the first rinsing phase. A separating agent can be used to separate the formed flocs from the washing liquid, thus making the washing liquid sufficiently clean for reuse in the subsequent first rinsing phase.

[0006] EP 2 181 636 A1 discloses a method for operating a dishwasher, wherein a plurality of washing programs are provided which can be selected by the user and which comprise: (a) a first washing program in which the circulation pump is operated at a nominal speed, and (b) a second washing program in which the circulation pump is operated at a speed reduced from the nominal speed for at least part of the program and in which at least one soaking step is provided during which the circulation pump is inactive.

[0007] A cleaning agent can be added to the circulating water during a pre-rinse step.

[0008] Against this background, one object of the present invention is to improve the cleaning of dishes by means of a dishwasher.

[0009] Accordingly, a method for operating a dishwasher, in particular a household dishwasher, is proposed. The dishwasher has a control device for executing a washing program from a number of washing programs, wherein each washing program comprises a number of sub-program steps that are performed sequentially during the execution of the washing program, wherein at least one specific washing program of the number comprises a pre-wash sub-program step and a subsequent cleaning sub-program step. The method comprises executing the specific washing program, which comprises: in the pre-wash sub-program step: A) supplying water to a washing chamber of the dishwasher to provide a washing liquor, B) dosing a predetermined amount of a cleaning agent into the washing liquor, C) circulating the washing liquor and applying the washing liquor to items arranged in the washing chamber, wherein a heater for heating the washing liquor is inactive during the pre-wash, and in the cleaning sub-program step: D) heating the washing liquor to a predetermined temperature, and E) circulating the heated washing liquor and applying the heated washing liquor to items arranged in the washing chamber.

[0010] This process has the advantage that, by adding the detergent during the pre-wash sub-program step, a chemical cleaning effect, achieved by the detergent dissolved in the wash liquor, is already developed during the pre-wash phase. This increases the chemical integral, which is determined, for example, by the time integral of the concentration of chemical substances active in the wash liquor. Overall, therefore, the pre-wash increases the cleaning performance, thus improving the cleaning efficiency of the dishwasher.

[0011] The control device can be implemented in hardware and / or software. In a hardware implementation, the control device can be embodied, for example, as a computer, a microprocessor such as a CPU (central processing unit), an application-specific integrated circuit (ASIC), or a programmable logic controller (PLC). In a software implementation, the control device can be embodied as a computer program product, a function, a routine, an algorithm, a part of a program code, or an executable object.

[0012] The number of washing programs, for example, includes several washing programs that differ from one another in their respective sequences. Examples of different washing programs are a standard washing program, an intensive washing program, an economical washing program, a glass washing program, and the like. The intensive washing program aims for particularly high cleaning performance; for example, the temperature of the washing solution is regulated to a particularly high value and the circulation pump is operated at a particularly high speed. In contrast, the economical washing program aims, for example, to achieve the lowest possible energy and resource consumption; the temperature of the washing solution is regulated to a particularly low value and, for example, the running time of sub-program steps of the washing program is extended.It should be noted that the above examples are not exhaustive but merely serve as examples to illustrate different dishwashing programs. A wide variety of different dishwashing programs can be provided, and the dishwashing programs can also be dynamically adapted depending on recorded measured values, such as the quantity of dishes to be washed, the type of dishes to be washed, the degree of soiling, and the like.

[0013] The sub-program steps provided for in a particular dishwashing program are carried out sequentially. This means, for example, that only one sub-program step is active at any one time during the dishwashing program. Partial or complete pumping out of the dishwashing liquor and / or dilution of the dishwashing liquor with fresh water may be provided between individual sub-program steps, but this is not mandatory. For example, a standard dishwashing program comprises the following sub-program steps in their chronological sequence: pre-wash - cleaning - final rinse - drying. In this standard dishwashing program, the pre-wash takes place, for example, without heating the dishwashing liquor and without adding detergent. At the end of the pre-wash, the dishwashing liquor is partially pumped out, and at the start of the cleaning process, the dishwashing liquor is topped up to a specific target volume, for example with fresh water or stored water.Furthermore, the wash water is heated to a specific temperature during cleaning and detergent is added. At the end of cleaning, for example, the wash water is completely pumped out and water is added again to begin the final rinse. Rinse aid can be added during the final rinse. Depending on the drying technology used, the wash water can be heated during the final rinse. If zeolite drying is used, heating of the wash water during the final rinse is not necessary. After the final rinse, the wash water is completely pumped out, although it can also be temporarily stored for use in a later sub-program step or wash program. During drying, the air in the wash chamber can be circulated to achieve better drying. It should be noted that each of the number of wash programs can comprise the sub-program steps explained above, possibly in a modified form.In particular, the specific washing program may correspond to the standard washing program.

[0014] The specific washing program may correspond to any of the washing programs in the number. In particular, each of the washing programs in the number may include the sub-program steps of pre-wash and cleaning, as specified for the specific washing program.

[0015] The specific dishwashing program comprises at least the pre-wash and cleaning sub-program steps. In a conventional dishwashing program, the pre-wash sub-program step is particularly distinguished by the fact that it occurs before the cleaning sub-program step, whereby the dishwashing liquor is not heated by a heater during the pre-wash. The pre-wash of the proposed method differs from such a conventional pre-wash in that, in this case, detergent is dosed during the pre-wash.

[0016] The supplied water may include fresh water from a supply network and may include stored water, for example, that was temporarily stored in a previously performed washing program. In particular, water used for rinsing in a previous washing program may be temporarily stored in this way and reused in the subsequent washing program.

[0017] The special feature of the proposed method is that the cleaning agent intended for cleaning the washware is dosed into the wash liquor during the pre-wash phase, particularly at the beginning of the pre-wash phase. As already explained at the beginning, this allows the chemical cleaning effect achieved by the cleaning agent to take effect early on and thus, with the same sub-program step duration, to have a longer duration of effect compared to a conventional wash program, in which the cleaning agent is only dosed in a sub-program step called "cleaning."

[0018] The circulating wash water is achieved, in particular, by a circulation pump, which is located, for example, in a pump sump at the bottom of the wash chamber. The circulation pump conveys the wash water, for example, through a hydraulic system of the dishwasher, which in particular comprises one or more spray devices, such as spray arms or spray nozzles. The spray devices dispense the wash water onto the washware at a specific pressure. This exposure of the wash water to the washware cleans the washware.

[0019] According to one embodiment of the method, a switchable pretreatment sub-program step is provided, which, when switched on, is performed directly before the pre-rinsing sub-program step. The pretreatment comprises: Supplying water into the washing chamber of the dishwasher to provide a washing solution, heating the washing solution to a predetermined temperature, and circulating the heated washing solution and applying the washing solution to the items arranged in the washing chamber.

[0020] Pretreatment differs significantly from the pre-rinse of a specific wash program. In particular, pretreatment takes place in addition to pre-rinse. Pretreatment occurs without adding a detergent from a program-controlled dosing unit to the wash liquor. In other words, during pretreatment, the wash liquor is free of, for example, detergent added separately from a program-controlled dosing unit. However, the wash liquor may contain traces of detergent or rinse aid if it is provided by temporarily stored water from a previous wash program.

[0021] In embodiments, the addition of detergent can occur before or during the pretreatment subprogram step. For example, a dosing unit can have an "open chamber" intended to hold detergent and from which the detergent is dispensed into the wash chamber, for example, when the dishwasher door is closed. Or the open chamber can be designed so that the detergent is discharged from the chamber and enters the wash liquor when the wash liquor is circulated. This type of addition corresponds to a manual addition of detergent and is therefore to be distinguished from program-controlled addition via the dosing unit. The detergent can also be added directly into the wash chamber by a user, so that it is already absorbed by the wash liquor during pretreatment.

[0022] "Immediately preceding" means that the pretreatment takes place immediately before the pre-rinse. This means that the pre-rinse directly follows the pretreatment. A partial or complete exchange of the rinse liquor and / or dilution of the rinse liquor with fresh water between the two sub-program steps can be provided. The pretreatment sub-program step and the pre-rinse sub-program step can be differentiated from each other, for example, by the rinse liquor being partially or completely exchanged and / or diluted during the transition from pretreatment to pre-rinse.

[0023] Because pretreatment is performed at an elevated wash water temperature, the washware in the wash chamber heats up during pretreatment. This heat therefore stores a certain amount of heat, which is then released back into the wash water in a later sub-program step, particularly pre-wash and cleaning. As a result, the wash water is warmer during pre-wash than if pretreatment is not performed. This effect is particularly advantageous if the wash water is partially or completely replaced after pretreatment.

[0024] In this context, replacement means that a specific volume of the washing solution is pumped out using a pump and the pumped-out volume is replaced at a later time, for example with fresh water. The washing solution can have a different volume before pumping out and after refilling, which means that the exact volume pumped out does not necessarily have to be replaced, but more or less volume than that pumped out can be added. This dilutes the washing solution in the sense that the concentration of dirt in the washing solution is reduced. This can help maintain the washing solution's ability to absorb dirt. Even if the washing solution is completely replaced, the temperature of the washing solution during pre-rinsing will be higher than if no pre-treatment is carried out.

[0025] Dilution means that no rinse water is pumped out, but rather additional fresh water is added. This increases the volume of the rinse water. When the rinse water is diluted, the absolute amount of dirt in the rinse water remains the same, but the dilution also enables the rinse water to absorb additional dirt.

[0026] The increased temperature of the wash liquor during pre-rinsing has the advantageous effect that the cleaning agent dissolves particularly well in the wash liquor, i.e., it dissolves particularly quickly and can therefore be present in a high concentration more quickly. Furthermore, thermally activated components of the cleaning agent, such as enzymes, can already exert their effect during pre-rinsing due to the increased temperature. The other chemical effects exerted by the cleaning agent are also more pronounced at elevated temperatures, and in particular, they are accelerated. This is due, for example, to the fact that most dissolution processes are endothermic reactions whose kinematics benefit from elevated temperatures.

[0027] The pretreatment sub-program step can be activated by a user through a corresponding input. For example, the user presses a corresponding function key on a control unit for controlling the dishwasher. The activation can be optionally performed for each of the multiple wash programs.

[0028] According to a further embodiment of the method, step B) of pre-rinsing is carried out only when the pre-treatment sub-program step has been completed.

[0029] This means that the detergent is only added during the pre-rinse if the pre-treatment has been completed. If the pre-treatment has not been completed, the detergent is only added during the cleaning process, for example.

[0030] According to a further embodiment of the method, this comprises at least partial pumping out of the washing liquor between the pretreatment sub-program step and the pre-rinse sub-program step.

[0031] The pumped-out amount of rinse water is replaced at the beginning of the pre-rinse cycle, for example, with fresh water, so that the rinse water has a sufficiently high volume. This sufficiently high volume corresponds, in particular, to the minimum required flow rate for the circulation pump to run smoothly and, for example, to avoid drawing in air, which can lead to increased noise and reduced efficiency of the circulation pump.

[0032] According to a further embodiment of the method, this additionally comprises the steps: Detecting a quantity of dirt dissolved in the rinsing solution at the end of pre-treatment, determining a volume of rinsing solution to be pumped out depending on the quantity of dirt detected, and pumping out the determined volume before starting pre-rinsing.

[0033] This has the advantage that the smallest possible amount of the rinsing liquor is exchanged, which on the one hand reduces water consumption and on the other hand also reduces energy consumption, since the heat energy stored in the rinsing liquor remains usable for the further sub-program steps.

[0034] The amount of dissolved dirt can also be referred to as the dirt load. The dirt load is expressed, for example, in units of particles / volume or grams / volume, where the volume refers to the rinse water. The dirt load can be measured using various methods, for example, optical measuring techniques based on transmission measurements and / or light scattering by the rinse water, conductivity or impedance measurements of the rinse water, determination of sieve loading, and the like. These and other methods for measuring the dirt load are known.

[0035] The volume to be pumped out is determined, for example, based on a predetermined threshold for the dirt load at the beginning of the pre-rinse. This means that the proportion of the wash liquor that needs to be pumped out is determined so that the wash liquor reaches or falls below the predetermined threshold for the dirt load at a volume predetermined for the pre-rinse. In particular, the predetermined volume corresponds at least to the circulation volume. The predetermined volume is achieved, for example, by topping up the wash liquor with fresh water.

[0036] If the predetermined volume for pre-rinsing is equal to the volume during pre-treatment, the pumped-out volume is preferably replaced by supplying fresh water, for example at the beginning of pre-rinsing.

[0037] According to a further embodiment of the method, the predetermined temperature is in an interval between 30°C - 70°C, preferably between 40°C - 60°C, more preferably between 50°C - 60°C.

[0038] For example, the predetermined temperature is 55°C, and the wash liquor is heated to this temperature once, for example, at the beginning of the pretreatment. Subsequently, the temperature slowly drops due to heat losses from the dishwasher through conduction and radiation.

[0039] According to a further embodiment of the method, the cleaning agent dosed in step B) is a solid cleaning agent.

[0040] A solid detergent includes, for example, powder, granules, pellets, or even tablets. In particular, it can be a multifunctional tablet, which contains several different active substances, which are arranged in layers within the tablet, so that the different active substances enter the wash water at different times (namely, only when the outer layers have dissolved).

[0041] According to the invention, no further cleaning agent is added to the rinsing liquor except in step B) during the pre-rinsing and cleaning.

[0042] The addition of detergent in step B) is therefore the only program-controlled addition of detergent during the wash program. It should be noted that this does not preclude the addition of rinse aid during the final rinse.

[0043] For example, a dishwasher with a program-controlled dosing unit configured to add a single dose of detergent during a respective wash program is involved. The dosing unit comprises, for example, a chamber for holding the detergent. The chamber is initially closed at the start of the wash program, for example, by means of a spring-loaded flap, so that there is no contact between the wash water and the detergent. The chamber is then opened programmatically at a time specified in the wash program, so that from this point onward, the detergent comes into contact with the wash water and can be dissolved by the wash water.

[0044] According to a further embodiment of the method, a respective sub-program step of a respective washing program is defined by a plurality of parameters with associated parameter values, wherein the parameter values ​​of the sub-program steps pre-wash and clean of the specific washing program correspond to the parameter values ​​specified in a standard for determining an energy label determined in accordance with the standard for a specific region.

[0045] In Europe, the EN 60436:2020+AC:2020 standard applies to determining the performance characteristics of dishwashers, particularly energy consumption. This standard specifies a standard measurement method for determining the energy consumption of dishwashers. The energy label for the dishwasher is assigned based on the energy consumption determined in accordance with the standard. The washing program to be performed according to this standard is also referred to as the label program.

[0046] Each dishwasher manufacturer is interested in achieving the most favorable energy label possible, which is why the heating is deactivated, especially during the pre-wash phase of the label program, to save energy. Other wash programs, such as intensive wash programs or similar, may deviate from the label program and not achieve its energy efficiency.

[0047] The specific wash program may differ from the labeled program, but the parameter values ​​for pre-wash and cleaning will correspond to the labeled program. This means that the specific wash program may, for example, include the pre-treatment subprogram step, which is not part of the labeled program.

[0048] According to a further embodiment of the method, a pump speed is reduced during pre-rinsing and / or cleaning compared to a rinsing program in which step B) is not carried out during pre-rinsing but during cleaning.

[0049] This embodiment is particularly advantageous if the pretreatment subprogram step was performed before the pre-rinse. Due to the increased chemical cleaning performance of the proposed method, the pump speed can be reduced without compromising cleaning performance compared to the conventional rinse program. Thus, noise emissions during cleaning and energy consumption of the circulation pump can be reduced without compromising cleaning performance.

[0050] According to a further embodiment of the method, a duration of the pre-rinsing sub-program step and / or the cleaning sub-program step is reduced compared to a rinsing program in which step B) is not carried out during the pre-rinsing but during the cleaning.

[0051] This embodiment is particularly advantageous when the pretreatment sub-program step was performed before the pre-wash. Due to the increased chemical cleaning performance of the proposed method, the duration of the pre-wash and / or cleaning can be reduced without compromising the cleaning performance compared to the conventional wash program. Thus, the overall duration of the wash program can be shortened without compromising the cleaning performance.

[0052] According to a second aspect, a computer program product is proposed which comprises instructions which, when the program is executed by a computer, cause the computer to carry out the method according to the first aspect.

[0053] For example, the computer is linked to a dishwasher and set up to control it accordingly.

[0054] A computer program product, such as a computer program means, can be provided or delivered, for example, as a storage medium, such as a memory card, USB stick, CD-ROM, DVD, or in the form of a downloadable file from a server in a network. This can be done, for example, in a wireless communications network by transmitting a corresponding file with the computer program product or the computer program means.

[0055] According to a third aspect, a dishwasher, in particular a household dishwasher, is proposed. The dishwasher has a control device for executing a washing program from a number of washing programs, wherein a respective washing program comprises a number of sub-program steps that are performed sequentially during the execution of the washing program, wherein at least one specific washing program of the number comprises a pre-wash sub-program step and a subsequent cleaning sub-program step, and wherein the control device is configured to control the dishwasher using a method according to the first aspect.

[0056] This dishwasher has the same advantages as those explained for the method according to the first aspect. The embodiments and features explained for the method apply accordingly to the proposed dishwasher.

[0057] The dishwasher may, in particular, comprise a washing chamber, a hydraulic system with spray devices, a circulation pump, a heater, a dish basket for holding dishes, a dosing unit for adding detergent, and the like. The dosing unit is, in particular, configured for the program-controlled, one-time addition of a single dose of a solid detergent.

[0058] Further possible implementations of the invention also include combinations of features or embodiments described above or below with respect to the exemplary embodiments that are not explicitly mentioned. In this case, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention.

[0059] Further advantageous embodiments and aspects of the invention are the subject of the dependent claims and the exemplary embodiments of the invention described below. The invention will be explained in more detail below using preferred embodiments with reference to the accompanying figures. Fig. 1 shows a schematic perspective view of an embodiment of a dishwasher; Fig. 2 shows a schematic flow diagram for a conventional dishwashing program; Fig. 3 shows a schematic flow diagram for a rinsing program according to a first embodiment; Fig. 4 shows a schematic flow diagram for a washing program according to a second embodiment; and Fig. 5 shows a schematic block diagram of an embodiment of a method for operating a dishwasher.

[0060] In the figures, identical or functionally identical elements have been given the same reference numerals unless otherwise stated.

[0061] The Fig. 1 shows a schematic perspective view of an embodiment of a dishwasher 1, which in this example is designed as a household dishwasher. The household dishwasher 1 comprises a washing container 2, which can be closed by a door 3, in particular in a watertight manner. For this purpose, a sealing device can be provided between the door 3 and the washing container 2. The washing container 2 is preferably cuboid-shaped. The washing container 2 can be arranged in a housing of the household dishwasher 1. The washing container 2 and the door 3 can form a washing chamber 4 for washing dishes.

[0062] Door 3 is in the Fig. 1 shown in its open position. The door 3 can be closed or opened by pivoting about a pivot axis 5 provided at a lower end of the door 3. With the help of the door 3, a loading opening 6 of the washing container 2 can be closed or opened. The washing container 2 has a base 7, a ceiling 8 arranged opposite the base 7, a rear wall 9 arranged opposite the closed door 3 and two side walls 10, 11 arranged opposite one another. The base 7, the ceiling 8, the rear wall 9 and the side walls 10, 11 can be made, for example, from a stainless steel sheet. Alternatively, the base 7 can, for example, be made from a plastic material.

[0063] The household dishwasher 1 further comprises at least one dishware receptacle 12 to 14. Preferably, several, for example three, dishware receptacles 12 to 14 can be provided, wherein the dishware receptacle 12 can be a lower dishware receptacle or a lower basket, the dishware receptacle 13 can be an upper dishware receptacle or an upper basket, and the dishware receptacle 14 can be a cutlery drawer. Fig. 1 As further shown, the dishware receptacles 12 to 14 are arranged one above the other in the washing container 2. Each dishware receptacle 12 to 14 can be selectively moved into or out of the washing container 2. In particular, each dishware receptacle 12 to 14 can be pushed or moved into the washing container 2 in an insertion direction E and pulled or moved out of the washing container 2 in an extension direction A opposite to the insertion direction E.

[0064] In the door 3 of the dishwasher 1, a control device 15 and a dosing unit 16 are arranged. The control device 15 is for carrying out a washing program SP1, SP1* (see Fig. 3 or 4 ) from a number of washing programs. Each washing program SP1, SP1* comprises a number of sub-program steps TP0 - TP4 (see Fig. 2 - 4 ), which are carried out sequentially during the execution of the washing program SP1, SP1*, wherein at least one specific washing program SP1, SP1* of the number comprises a pre-wash sub-program step TP1 and a subsequent cleaning sub-program step TP2. The dosing unit 16 is designed in particular for the program-controlled addition of a cleaning agent into the washing chamber 4. For example, the dosing unit 16 is designed for the one-time addition of a single dose of the cleaning agent during a respective washing program. To add the cleaning agent, the dosing unit 16 is controlled by the control device 15 at an addition time predetermined for a respective washing program.

[0065] The pre-rinse sub-program step TP1 comprises at least supplying water to the wash chamber 4 of the household dishwasher 1 to provide a wash liquor. Fresh water or temporarily stored water from a previously run wash program can be used here. The supply of fresh water is controlled, for example, by activating a valve arranged in a water connection line (not shown). Temporarily stored water can, for example, be stored in a tank of the dishwasher 1 and admitted into the wash chamber 4 in this step (not shown). Furthermore, the pre-rinse TP1 comprises dosing a predetermined amount of a cleaning agent into the wash liquor. The predetermined amount is, in particular, the amount of cleaning agent filled into the dosing unit 16 by a user of the household dishwasher 1.In addition, the pre-rinse TP1 includes circulating the wash liquor and applying the wash liquor to the washware arranged in the wash chamber 4, for example, by means of a circulation pump (not shown). A heater (not shown) for heating the wash liquor is inactive during the pre-rinse TP1, so that a temperature of the wash liquor is established based on an initial temperature of the supplied water and the temperature of the washware and the wash chamber 4.

[0066] The sub-program step cleaning TP2 comprises heating the washing liquor to a predetermined temperature and circulating the heated washing liquor and applying the heated washing liquor to the items to be washed arranged in the washing chamber 4.

[0067] The control device 15 is particularly designed to carry out the Fig. 3 and Fig. 4 explained washing programs SP1, SP1* and the one based on the Fig. 5 explained procedure.

[0068] Fig. 2 shows a schematic flow diagram for a conventional dishwashing program SP. Two diagrams are shown one above the other, each representing a temporal sequence along a horizontal time axis t. The upper diagram shows the individual sub-program steps TP1 - TP4, and the lower diagram shows an example of a temperature profile of the dishwashing liquor during the execution of the dishwashing program SP. Identical points in time on the time axes t correspond to one another.

[0069] At a time t0, the wash program SP is started. First, a pre-wash TP1 is performed. The wash liquor is not heated during the pre-wash TP1, so its temperature T0 is adjusted based on the initial temperature of the supplied water and the temperature of the washware and the wash chamber 4, and remains essentially constant. In this example, the temperature T0 is room temperature. During the pre-wash TP1, the wash liquor is circulated and exposed to the washware.

[0070] At time t1, pre-wash TP1 ends and cleaning TP2 begins. At this time t1, the wash liquor is heated to a target temperature T1. In addition, at the beginning of cleaning TP2, detergent DET is added, as indicated by the arrow. During cleaning TP2, the wash liquor is circulated and exposed to the washware. The temperature of the wash liquor slowly drops during this period, for example, due to heat losses from dishwasher 1.

[0071] At time t2, cleaning TP2 is finished. In this example, the wash liquor is now completely pumped out. The final rinse TP3 begins, for which fresh water is added. During the final rinse TP3, a rinse aid can be added (not shown). During the final rinse TP3, the wash liquor is circulated and the washware is exposed to it. Towards the end of the final rinse TP3, the wash liquor is heated to bring the washware to an elevated temperature, which supports the subsequent drying step TP4. Finally, in the final rinse TP3, the wash liquor is pumped out and the drying process TP4 begins.

[0072] In the drying step TP4, the dishes rest and dry by dripping and evaporating the adhering moisture.

[0073] Fig. 3 shows a schematic flow diagram for a washing program SP1 according to a first embodiment. The washing program SP1 comprises, for example, the same sub-program steps TP1 - TP4, which are based on the Fig. 2 In contrast to the conventional SP washing program of the Fig. 2 In the SP1 wash program, the Fig. 3 The detergent DET is dosed at the beginning of the pre-rinse TP1. This results in an extended contact time of the chemical active ingredients of the detergent, namely the combined duration of the pre-rinse TP1 and the cleaning TP2, and thus an improved cleaning performance. The temperature profile of the wash liquor in this example is also the same as that of the Fig. 2 .

[0074] Fig. 4 shows a schematic flow diagram for a washing program SP1* according to a second embodiment. The washing program SP1* of the Fig. 4 is based on the SP1 rinsing program of the Fig. 3 However, a pretreatment TP0 is carried out before the pre-rinse TP1.

[0075] Pretreatment TP0 begins at a time t0* that precedes time t0. As can be seen from the corresponding temperature curve, the wash liquor is heated during pretreatment TP0, in this example to temperature T1. During pretreatment TP0, the wash liquor is circulated and exposed to the washware. The temperature of the wash liquor slowly drops. At the end of pretreatment TP0, in this example, the wash liquor is completely pumped out. In some embodiments, partial pumping may be provided.

[0076] At time t0, the pre-wash TP1 begins again, with water being added first. Since the wash items and the wash chamber 4 are still at an elevated temperature, the supplied wash liquor, which is supplied in particular at temperature T0, heats up to temperature T2. This elevated temperature T2 of the wash liquor has the advantageous effect that the cleaning agent DET added at the beginning of the pre-wash TP1 dissolves better in it and achieves greater effectiveness. The further sequence of the wash program SP1* corresponds, for example, to the wash program SP1 of the Fig. 3 .

[0077] A distinction can be made between the sub-program steps pretreatment TP0 and pre-rinse TP1 based on the composition of the rinse liquor, whereby the soil load of the rinse liquor is higher at the end of pretreatment TP0 than at the beginning of pre-rinse TP1. This is achieved by partially or completely replacing the rinse liquor and / or by diluting it with fresh water.

[0078] It should be noted that the individual sub-program steps can also have an internal subdivision, for example into several phases. Thus, phases with different parameter values, for example for the speed of the circulation pump or for setting a water diverter and the like, can be provided. In the wash programs SP1, SP1*, a partial or complete exchange of the wash liquor can take place between two respective sub-program steps. This can be carried out in particular depending on the dirt load of the wash liquor at a particular time. In the drying step TP4, the air in the wash chamber 4 can be circulated and an inner wall of the wash chamber 4 can be cooled in order to accelerate the condensation of moisture. As an alternative to heating the wash liquor in the final rinse TP3 to heat the washware, a zeolite drying device can also be provided.

[0079] It should also be noted that the temperature curves shown are only examples and variations are possible.

[0080] Fig. 5 shows a schematic block diagram of an embodiment of a method for operating a dishwasher 1, for example the one shown in the Fig. 1 household dishwasher shown. The process steps S1 - S5 shown relate to a specific washing program SP1, SP1* (see Fig. 3 or 4 ), which contains a sub-program step pre-rinse TP1 (see Fig. 3 or 4 ) and a sub-program step Cleaning TP2 (see Fig. 3 or 4 ) includes.

[0081] The pre-rinse sub-program step TP1 comprises, in a first step S1, the supply of water into a rinsing chamber 4 (see Fig. 1 ) of the dishwasher 1 for providing a wash liquor, in a second step S2 the dosing of a predetermined amount of a cleaning agent into the wash liquor and in a third step S3 the circulating of the wash liquor and the application of the wash liquor to the wash ware arranged in the wash chamber 4. The dosing of the cleaning agent is in particular a program-controlled, one-time dosing of a single dose of the cleaning agent for the wash program SP1, SP1*. A heater for heating the wash liquor is inactive during the pre-wash TP1. The sub-program step cleaning TP2 comprises in a step S4 the heating of the wash liquor to a predetermined temperature T1 (see Fig. 3 or 4 ), and in a further step S5, the heated rinsing liquor is circulated and the heated rinsing liquor is applied to the items to be washed arranged in the rinsing chamber 4.

[0082] It should be noted that the method may include further method steps that are carried out before step S1 or after step S5. An example of this are additional method steps for carrying out the sub-program step Pretreatment TP0 (see Fig. 4 ) before step S1 and additional process steps for carrying out the partial program steps rinsing TP3 and / or drying TP4 (see Fig. 3 or 4 ). In addition, the pre-rinsing TP1, which in this example comprises steps S1 - S3, and the cleaning TP2, which comprises steps S4 and S5, can comprise further process steps, provided that these do not contradict the steps shown.

[0083] Although the present invention has been described using exemplary embodiments, it can be modified in many ways. Reference symbols used:

[0084] 1 Dishwasher 2 Washing container 3 Door 4 Washing chamber 5 Swivel axis 6 Loading opening 7 Floor 8 Ceiling 9 Rear wall 10 Side wall 11 Side wall 12 Dishwasher receptacle 13 Dishwasher receptacle 14 Dishwasher receptacle 15 Control device 16 Dosing unit AExtraction direction DETDetergent addition EInsertion direction S1Process step S2Process step S3Process step S4Process step S5Process step SPWash program SP1Wash program SP1*Wash program tTime TTemperature T0Temperature value T1Temperature value T2Temperature value t0Time t0*Time t1Time t2Time t3Time t4Time TP0Sub-program step TP1Sub-program step TP2Sub-program step TP3Sub-program step TP4Sub-program step

Claims

1. A method for operating a dishwasher (1), in particular a household dishwasher, which has a control device (15) for executing a washing program (SP1, SP1*) from a number of washing programs, wherein a respective washing program (SP1, SP1*) comprises a number of sub-program steps (TP0 - TP4) which are carried out sequentially during the execution of the washing program (SP1, SP1*), wherein at least one specific washing program (SP1, SP1*) of the number comprises a pre-wash sub-program step (TP1) and a subsequent cleaning sub-program step (TP2), the method comprising the execution of the specific washing program (SP1, SP1*), which comprises: in the pre-wash sub-program step (TP1): A) supplying (S1) water into a washing chamber (4) of the dishwasher (1) to provide a washing solution, B) dosing (S2) a predetermined amount of a cleaning agent into the washing solution,C) Circulating (S3) the washing liquor and applying the washing liquor to the items to be washed arranged in the washing chamber (4), wherein a heater for heating the washing liquor is inactive during the pre-wash (TP1), and in the sub-program step cleaning (TP2): D) Heating (S4) the washing liquor to a predetermined temperature (T1), and E) Circulating (S5) the heated washing liquor and applying the heated washing liquor to the items to be washed arranged in the washing chamber (4), characterized in that except in step B) during the pre-rinse (TP1) and cleaning (TP2) no further cleaning agent is added to the rinsing liquor.

2. Method according to claim 1, characterized bya switchable pretreatment sub-program step (TP0), which is carried out directly before the pre-rinse sub-program step (TP1), the pretreatment (TP0) comprising: supplying water into the washing chamber (4) of the dishwasher to provide a washing liquor, heating the washing liquor to a predetermined temperature (T1), and circulating the heated washing liquor and applying the washing liquor to the items to be washed arranged in the washing chamber (4).

3. Method according to claim 2, characterized in that that step B) of pre-rinsing (TP1) is only carried out when the sub-program step pre-treatment (TP0) has been completed.

4. Method according to claim 2 or 3, characterized by : at least partial pumping out of the rinsing liquor between the pre-treatment sub-program step (TP0) and the pre-rinse sub-program step (TP1).

5. Method according to claim 4, characterized by: Determining a quantity of dirt dissolved in the rinsing solution at the end of pre-treatment (TP0), determining a volume of rinsing solution to be pumped out depending on the detected quantity of dirt, and pumping out the determined volume before starting pre-rinsing (TP1).

6. Method according to one of claims 2 to 5, characterized in that the predetermined temperature (T1) lies in an interval between 30°C - 70°C, preferably between 40°C - 60°C, more preferably between 50°C - 60°C.

7. Method according to one of claims 1 to 6, characterized in that the cleaning agent dosed in step B) is a solid cleaning agent.

8. Method according to one of claims 1 to 7, characterized in thata respective sub-program step (TP0 - TP4) of a respective washing program (SP1, SP1*) is defined by a plurality of parameters with associated parameter values, wherein the parameter values ​​of the sub-program steps pre-wash (TP1) and cleaning (TP2) of the specific washing program correspond to the parameter values ​​specified in a standard for determining an energy label specified in accordance with the standard for a specific region.

9. Method according to one of claims 1 to 8, characterized in that a pump speed is reduced during pre-rinsing (TP1) and / or cleaning (TP2) compared to a rinsing program in which step B) is not carried out during pre-rinsing (TP1) but during cleaning (TP2).

10. Method according to one of claims 1 to 9, characterized in thata duration of the pre-rinse sub-program step (TP1) and / or the cleaning sub-program step (TP2) is reduced compared to a washing program in which step B) is not carried out during the pre-rinse (TP1) but during the cleaning (TP2).

11. A computer program product comprising instructions which, when executed by a computer, cause the computer to carry out the method according to any one of claims 1 to 10.

12. Dishwasher (1), in particular a household dishwasher, with a control device (15) for carrying out a washing program (SP1, SP1*) from a number of washing programs, wherein a respective washing program (SP1, SP1*) comprises a number of sub-program steps (TP0 - TP4) which are carried out sequentially when carrying out the washing program (SP1, SP1*), wherein at least one specific washing program (SP1, SP1*) of the number comprises a pre-wash sub-program step (TP1) and a subsequent cleaning sub-program step (TP2), and wherein the control device is designed to control the dishwasher (1) using a method according to one of claims 1 to 10.

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