EP2292133B1 - Dishwasher and method for performing a washing cycle with a dishwasher - Google Patents

Description

The present invention relates to a dishwasher, in particular a domestic dishwasher, with a control device in which at least one wash program for controlling a wash cycle for cleaning items is deposited, and with a water inlet device, which controllable by the control device hot water valve and controllable by the control device cold water valve wherein the hot water valve for receiving hot water from an external hot water supply, in particular from a at least partially powered by a solar thermal system hot water supply, and the cold water valve for receiving cold water from an external cold water supply is provided, and wherein the at least one rinse program provides at least one rinsing step of a receiving phase for receiving water by means of the water inlet device and a spraying phase for spraying dishes located in a washing chamber with a rinse liquor containing water.

From the EP 1 683 904 A1 A method of regulating the temperature of mixed water fed from separate cold and hot water feeds is known in which, at the start of the water inlet, the control system is adjusted so that the cold water inlet is shut off and the hot water inlet is fully open, and during the water inlet the control of the mixed water temperature when exceeding the predetermined setpoint occurs in such a way that the amount of inflowing hot water throttled and the cold water inlet is partially increased, and that on reaching the set temperature in the mixed water, the amounts of the two inflowing streams are kept constant.

From the EP 2 286 710 A2 is a water-conducting household appliance with a hot water connection and a cold water connection known. In this case, a first temperature measuring device is arranged in the hot water connection, which established is to measure the temperature of the hot water coming from the hot water network.

The object of the present invention is to improve the efficiency of a dishwasher comprising a hot water inlet and a cold water inlet.

The object is achieved in a dishwasher of the type mentioned above in that the at least one rinsing program provides a first phase of the receiving phase, while the hot water valve takes a recording of hot water and during the means of at least one downstream of the water inlet temperature sensor arranged a measurement of a temperature the recorded hot water takes place.

In the dishwasher according to the invention, the items to be washed, in particular items to be rinsed, are introduced into a rinsing container and cleaned there in a rinsing process, which is also called rinse, with the aid of rinsing liquor and then dried. The goal is to do a rinse so that a predefined cleaning result and a predefined drying result are achieved as efficiently as possible. Demanded is a high overall efficiency, which results in particular from the cleaning efficiency and the drying efficiency. The cleaning efficiency corresponds in particular to the ratio of the cleaning result achieved by means of a rinse cycle and the effort required for this purpose, wherein the effort can include several dimensions, for example the energy requirement, the water requirement and / or the time required. Furthermore, the drying efficiency corresponds in particular to the ratio of the drying result achieved by means of a rinse cycle and the effort required for this purpose, wherein the effort here can also include several dimensions, for example the energy requirement and / or the time required.

Under a rinsing liquor is understood to mean a liquid which is intended to be applied to the items to be washed in order to clean this and / or treat it in a different way. For example, rinsing liquor may also be provided for heating the items to be washed, which is customary, for example, during a rinsing step. A rinse liquor usually consists to a large extent of water. Depending on the operating phase of the dishwasher, the rinsing liquor can be enriched with cleaning agents, with cleaning aids, such as, for example, rinse aid and / or with dirt that has been removed from the items to be washed.

In the dishwasher according to the invention, a control device is provided in which one or more wash programs for controlling a wash cycle for cleaning items to be washed are stored. The control device can be designed as a so-called sequence control, in particular as an electronic sequence control. Advantageously, several wash programs are provided, one of which can be selected and started by the operator. This makes it possible to adjust the sequence of a rinse cycle in particular to the load, to the type of loading, to the degree of soiling of the items to be washed and / or to the desired duration of the rinse cycle.

In the dishwasher, which has both a hot water inlet and a cold water inlet, the hot water inlet has a hot water valve and the cold water inlet on a cold water valve. The hot water valve and the cold water valve are separately controllable by a control device of the dishwasher according to the invention. Thus, it is possible during the execution of a rinse to record hot water and / or cold water depending on a called wash program. The inventive temperature measurement of the dishwasher makes it possible for the washing programs stored there to realize the possible increase in efficiency through the use of hot water.

At least one rinsing program for cleaning the items to be washed expediently comprises a rinsing step, in which water is taken up, a rinsing liquor comprising absorbed water is formed, and the items to be rinsed in the rinsing chamber are sprayed with rinsing liquor. Conveniently, the rinse program provides several such rinsing steps. This may in particular be a pre-rinse step, a cleaning step, an intermediate rinse step and a rinse step in this order. However, it is also possible to provide rinsing programs in which one or more of these program steps are hidden. Also, rinse programs are possible in which one or more of these program steps are repeated several times. Furthermore, a typical washing program includes an adjoining drying step for drying the cleaned items to be washed.

A pre-rinse step serves primarily to remove coarse contaminants from the items to be washed. The purpose of a subsequent cleaning step is to completely remove contaminants from the dishes. In this case, the rinsing liquor can expediently be mixed with cleaning agent in order to improve the cleaning effect. An intermediate rinsing step which may now be carried out serves, in particular, for the removal of cleaning agent residues which adhere to the items to be washed. A subsequent rinse step is intended in particular to avoid stains on the items to be washed, which could be caused by dissolved substances in the water, such as, for example, salt and / or lime. For this purpose, the rinsing liquor can be mixed with rinse aid during the rinse step. The dishwasher can provide so-called self-drying, in which case a further task of the rinsing step consists in the subsequent drying step prepare. In this case, the items to be washed are heated to a high temperature during the rinsing step by the rinsing liquor, so that water droplets adhering to the hot items to be evaporated in the subsequent drying step and precipitate on the inside of the rinse container due to the lower temperature prevailing there.

To the intended for spraying the items to be washed rinse with the respective cleaning and / or cleaning aids such. As rinse aid to be able to provide the dishwasher may have an automatic metering device.

In principle, the cleaning effect of a rinse cycle is the higher, the higher the temperatures of the rinsing liquors of the individual rinsing steps. In the case of self-drying, the effect of the drying effect is to increase with the temperature of the rinse cycle. In order to ensure the temperatures of the respective rinsing liquor provided in the individual rinsing steps under all environmental conditions, the dishwasher according to the invention may comprise a preferably electric heating device.

The water required for carrying out rinses will be taken up in the dishwasher according to the invention via a water inlet device, which has a hot water inlet and a cold water inlet. To operate the dishwasher, the hot water supply is connected to an external hot water supply and the cold water supply to an external cold water supply. Such a water inlet device may also be referred to as a bithermic water inlet device.

In this case, the hot water supply a hot water valve and the cold water inlet include a cold water valve, the hot water valve and the cold water valve are independently controllable by the controller. The hot water valve and / or the cold water valve may be formed as solenoid valves, which have only an open state and a closed state. By using such valves, it is possible in a simple manner to form a rinsing liquor, depending on the particular rinse program, which includes hot water from the hot water supply and / or cold water from the cold water supply. But it would also be possible to use throttle valves, which make it possible to precisely control the flow of hot water or cold water. In both cases can be dispensed with an external device for controlling the water absorption.

Furthermore, it can be provided that the hot water valve is arranged at an upstream end of a hot water hose and is adapted to be fastened to a fitting of the external hot water supply, and / or that the cold water valve is arranged at an upstream end of a cold water hose and designed such that it is attachable to a connector of the external cold water supply. For this purpose, the hot water valve and / or the cold water valve can have, for example, connection threads which correspond to threads of domestic taps. Such valves are also known as Aquastop valves.

The arrangement of the hot water valve and / or the cold water valve at the upstream end of the water inlet device has the advantage that practically no leakage water can escape from the dishwasher even in the event of damage as long as the valves are closed. If the valves are designed to close when not energized, leaking of leakage water from a switched-off dishwasher is prevented in virtually all cases. In order also to prevent leakage of leakage water from a switched-on dishwasher, the flow control device may be associated with a leak water sensor for detecting leakage water, so that the flow control device can close the valves when leak water occurs during operation of the dishwasher.

Furthermore, it may be provided that a downstream end of the hot water hose and a downstream end of the cold water hose are connected via a connecting piece in liquid-conducting manner to a supply hose, which is connected to a housing-fixed connection piece of the dishwasher. Such a design of the water inlet device is structurally simple and significantly shortens the total hose length required in many cases, in particular if the connection points of the external hot water supply and the external cold water supply are further away from the place of installation of the dishwasher, as in this case can be dispensed with two longer parallel tubes.

The use of hot water from an external hot water supply usually leads to a saving in electrical energy, since so the energy requirements of the electric heater of the dishwasher for heating rinse liquor can be reduced. However, in the context of generally increased operating costs of household heating systems, the additional costs of operating the domestic hot water supply caused by the removal of hot water in many cases exceed the saved costs of electricity. Therefore, it makes sense to feed the external hot water supply at least partially with a thermal solar system.

A thermal solar system is a technical system for converting solar energy into usable thermal energy. Here, thermal solar systems usually provide hot water in a temperature range of, for example, 40 ° C to 70 ° C ready, which makes a direct use of hot water for heating buildings but also as service water possible. Thermal solar systems typically include a plurality of solar collectors having an absorber surface that is heated by the electromagnetic solar radiation. From there, the heat can be transported by means of a fluid to a heat exchanger that generates the hot water. Alternatively or additionally, the hot water supply can also be fed by other low-cost hot water production facilities, such as gas burners, heat pumps, power plants and others.

In the dishwasher according to the invention, the temperature of the hot water provided by the hot water supply is measured at the beginning of the intake phase for receiving water for a rinse step. This makes it possible to control the further course of the rinsing step in an efficient manner.

The measurement of the temperature of the hot water takes place in that received during a first phase of the intake phase via the hot water valve hot water and the temperature of the recorded hot water with at least one temperature sensor is arranged downstream of the water inlet device. Such a measured value of the temperature of the hot water represents the temperature of the hot water, which actually has the hot water when it is inside the dishwasher. Such a value of the temperature of the hot water is more meaningful with regard to the further control of the rinsing step than a value which is measured, for example, in the region of the water feed device or in the region of the external hot water supply. The reason for this is that a cooling of the incoming hot water on its way into the interior of the dishwasher can be automatically taken into account by the invention.

In addition, practically all modern dishwashers have a temperature sensor arranged downstream of the water feed device, which can serve, for example, for controlling the heating device of the dishwasher. This already existing temperature sensor can be used during the intake of water for the rinsing step for measuring the temperature of the hot water. In this way, it is possible to dispense with an additional temperature sensor. By using an internal temperature sensor of the dishwasher for temperature measurement, it is also possible to dispense with external transmission lines for transmitting measured values of the temperature of the hot water. In particular, it is possible to dispense with such a transmission line which would connect the control device of the dishwasher to a control device of the external hot water supply or to an external measuring device.

The temperature sensor may be a thermistor, also called an NTC resistor, or a PTC thermistor. The electrical resistance of such devices is dependent on their temperature. Taking advantage of this property can be generated with a simple electronic circuit corresponding to the temperature of the hot water electrical signal generated by the control device of the dishwasher can be evaluated. The temperature sensor can in principle be arranged in each area of the dishwasher, in which a thermal contact with the recorded hot water is ensured.

According to an expedient development of the invention, it is provided that the at least one rinsing program provides for a second phase of the receiving phase, during which the water supply device is controlled on the basis of the measured temperature of the hot water. By such a control, it is possible to directly influence the adjusting temperature of the rinsing liquor for the rinsing step. In this way, the efficiency of the rinsing step can be increased in particular if the temperature of the hot water supplied by the external hot water supply is highly variable, which may occur, for example, when the external hot water supply is fed by a thermal solar system.

According to an advantageous embodiment of the invention, a recording of hot water and cold water is provided during the second phase of the recording phase, when the temperature of the hot water is greater than a designated for the rinsing step temperature of the rinse. The ratio of recorded hot water and cold water taken can thereby be adjusted so that the adjusting temperature corresponds exactly to the intended temperature of the wash liquor. In this case, the use of the heating device of the dishwasher in the respective rinsing step can be completely dispensed with. At the same time, only as much hot water is taken from the external hot water supply as absolutely necessary. When determining the quantities of hot or cold water to be taken during the second phase, the amount of hot water taken during the first phase can be taken into account. In this way, a precise adjustment of the temperature of the wash liquor is possible.

According to an advantageous embodiment of the invention, a recording of hot water, but not cold water is provided during the second phase of the recording phase, when the temperature of the hot water is less than or equal to the intended for the rinsing step temperature of the rinse. In this way results for the rinsing liquor, a temperature which corresponds to the temperature of the hot water, since during the entire recording phase no cold water is absorbed. In this way, the electrical energy requirement of the heater can be minimized, which is required to bring the wash liquor to the intended temperature. If the temperature of the hot water corresponds to the intended temperature of the rinsing liquor, it can even be dispensed with switching on the heating device of the dishwasher.

According to an expedient development of the invention, the first phase of the absorption phase of the spraying phase proceeds. Characterized in that the items to be washed only after the first phase of the recording phase, ie after the measurement of the temperature of the hot water is sprayed, prevents the items to be washed with a rinsing liquor of unknown temperature is sprayed. This can in particular be prevented that the items to be washed is damaged due to too high a temperature of the rinsing liquor, which can occur, for example, when using a solar thermal system in strong sunlight and low hot water withdrawal by other consumers.

According to a further expedient development of the invention, the spraying phase is provided after the recording of a determined based on the temperature of the hot water amount of cold water when the temperature of the hot water is greater than a designated for the rinsing step temperature of the rinse. In this way it is prevented that the items to be washed are sprayed with a rinsing liquor whose temperature exceeds the temperature intended for the rinsing step.

According to the invention, the hot water is circulated during the first phase of the intake phase by means of a circulating pump controlled by the control device. This makes it possible to generate more meaningful measured values, since this way local fluctuations in the temperature in the volume of the hot water used for the measurement are averaged out. Thus, the circulation of the warm water causes warmer components of the hot water and colder components of the hot water are mixed,
so that there is a better temperature measurement of the state of the hot water.

According to a particularly advantageous embodiment of the invention, the hot water is circulated during the first phase of the intake phase by pumped by means of a controlled by the controller circulating pump from a collecting pot of the washing chamber and is returned via a arranged in the washing chamber spraying such in the collecting pot that the In Spülkammerpositionierte items remains unaffected by the circulating hot water. Virtually all modern dishwashers have such a circulating pump, which is connected on the input side to a collecting pot of the washing chamber and on the output side to a spraying device arranged in the washing chamber, wherein the circulating pump and the spraying device are primarily intended to spray the dishes during a spraying phase. By now a usually already existing circulating pump and spraying device for circulating the hot water can be used during the measurement phase, the design effort to implement the invention can be kept low. It is necessary to circulate neither an additional circulation pump nor an additional means for returning the circulated water at its starting point. By the circulation takes place so that the items to be washed during the measurement phase hardly or not at all supplied with hot water, but largely unsprayed, especially largely dry, remains, damage to the items to be washed can be reliably prevented by too hot water.

According to the invention, during the first phase of the intake phase, a rotational speed of the circulating pump is controlled such that it is less than during the spraying phase. In this way, it can be prevented in many cases that the hot water emerging from the spray system can reach the items to be washed. At least this goal can be supported.

According to an expedient development of the invention, the spraying device has a plurality of spraying elements which can be individually connected to the circulating pump via a water diverter, the water diverter being controlled in such a way that during the first phase of the intake phase, the hot water is essentially returned to the collecting pot via a spray element arranged in a lower region of the rinsing chamber. This may increase the risk that the recirculated hot water during the first phase of the recording phase reaches the dishes, be further reduced.

Furthermore, the invention relates to a method for carrying out a rinse cycle with a dishwasher, in particular with a dishwasher according to the invention, which comprises a water inlet device for receiving water, wherein the water inlet device for receiving hot water with an external hot water supply, in particular with a at least partially by a thermal solar system fed hot water supply, and is connected to receive cold water with an external cold water supply, wherein at least one rinsing step is carried out in which received in a recording phase on the water inlet water and sprayed in a Besprühphase in a washing chamber befindliches ware with a water containing rinse containing.

In the method according to the invention, hot water is taken up during a first phase of the intake phase and the temperature of the hot water taken in is measured with at least one temperature sensor, which is arranged downstream of the water supply device.

The inventive method enables efficient operation of a dishwasher, in particular a dishwasher according to the invention. Further developments of the method according to the invention are explained in the description of the claimed dishwasher.

Other embodiments and further developments of the invention are given in the dependent claims. The above-explained and / or reproduced in the dependent claims advantageous embodiments and developments of the invention can be used individually or else in any combination with each other in the dishwasher according to the invention and the inventive method for use.

The invention, their training and further developments and their advantages will be explained below with reference to drawings.

Figur 1

ein vorteilhaftes Ausführungsbeispiel einer erfindungsgemäßen Haushaltsgeschirrspülmaschine in einer schematischen Seitenansicht,

Figur 2

einen beispielhaften Ablauf eines Spülgangs bei der erfindungsgemäßen Geschirrspülmaschine der Figur 1 und

Figur 3

einen weiteren beispielhaften Ablauf eines Spülgangs bei der erfindungsgemäßen Geschirrspülmaschine der Figur 1.

Show it:

FIG. 1

an advantageous embodiment of a domestic dishwasher according to the invention in a schematic side view,

FIG. 2

an exemplary sequence of a wash cycle in the dishwasher according to the invention the FIG. 1 and

FIG. 3

a further exemplary sequence of a wash cycle in the dishwasher according to the invention the FIG. 1 ,

In FIG. 1 only those components of a dishwasher are provided with reference numerals and explained which are necessary for the understanding of the invention. It goes without saying that the dishwasher according to the invention can comprise further parts and assemblies.

FIG. 1 shows an embodiment of a household dishwasher according to the invention 1 in a schematic side view. The dishwasher 1 has a control device 2, in which at least one wash program for controlling a wash cycle for washing dishes, in particular dishes, is deposited. Expediently, a plurality of washing programs are stored, so that by selecting a suitable washing program, the sequence of a controlled by the control unit 2 rinse, for example, to the load, to the type of load, to the degree of contamination of the dishes and / or to the desired duration of the wash can be adjusted. The one or more washing programs may comprise at least one pre-rinsing step, at least one cleaning step, at least one intermediate rinsing step, at least one rinsing step and / or at least one drying step.

The control device 2 is assigned an operating interface 3, which allows an operator of the dishwasher 1 to call up and start one of the washing programs.

The dishwasher 1 further comprises a rinsing container 4, which can be closed by a door 5, so that a closed rinsing chamber 6 is formed for rinsing dishes. In FIG. 1 the door 5 is shown in its closed position. The door 5 can be brought into an open position by pivoting about an axis arranged perpendicular to the plane of the drawing, in which it is aligned substantially horizontally and enables the introduction or removal of items to be washed. In the embodiment shown in Figure 1, the operating device 3 is arranged in a user-friendly manner at an upper portion of the door 5. The control device 2 is also positioned there, so that the required signal connections between the operating device 3 and the control device 2 can be kept short. In principle, however, it is possible to arrange the operating device 3 and / or the control device 2 elsewhere. The control device 2 could also be designed decentralized, which is understood to include spatially separated components, which are connected via communication means such that they can cooperate.

The dishwasher 1 has an upper dish rack 7 and a lower dish rack 8 for positioning dishes. The upper dish rack 7 is arranged on extension rails 9, which are each attached to a side wall of the washing compartment 4. The crockery basket 7 is extendable with the door 5 open by means of the extension rails 9 from the washing container 4, which facilitates the loading and unloading of the upper crockery basket 7. The lower dish rack 8 is arranged in an analogous manner on extension rails 10.

Furthermore, the dishwasher 1 comprises a schematically illustrated water inlet device 11. This has a hot water inlet 12, 13 and a cold water inlet 14, 15, wherein the hot water inlet 12, 13 for receiving hot water WW from an external hot water supply WH and the cold water inlet 14, 15 for receiving of cold water KW from an external cold water supply KH is provided. Such a water inlet device 11 is also referred to as a bithermic water inlet device 11.

Here, the hot water inlet 12, 13 comprises a hot water valve 12 and the cold water inlet 14, 15, a cold water valve 14. The hot water valve 12 and cold water valve 14 are constructed by the control device 2 controllable and basically identical. For example, both valves 12, 14 may be formed as a solenoid valve. The inlet sides of the valves 12, 14 are each formed so that they can be attached to fittings WH, KH a household water supply, for example, to faucets WH, KH, can be attached. The connection can be made in each case by means of a screw connection, a snap connection or the like. Such valves 12, 14 are also known by the name Aquastop valve 12, 14. The bithermic water feed device 11 can therefore also be referred to as a bithermic aquastop device 11.

Advantageously, the valves 12, 14 are closed when they are not activated, so that the dishwasher 1 is disconnected from the water supply in the off state. In this way, leakage of leakage water from the switched-off dishwasher 1 can be avoided in the event of a fault.

Intended are in FIG. 1 the input side of the hot water valve 12 to a hot water tap WH and the input side of the cold water valve 14 connected to a cold water tap KH. The output side of the hot water valve 12 is connected to a hot water hose 13 and the output side of the cold water valve 14 with a cold water hose 15, wherein the downstream ends of the hot water hose 13 and the cold water hose 15 are connected to an input side of a connecting piece 16. At its output side, a common inlet hose 17 for hot water and cold water connects, which in turn is connected to a connector 18 to a housing 19 of the dishwasher 1. By means of the water inlet device 11, it is consequently possible to individually direct hot water WW into the interior of the dishwasher 1 from an external hot water supply WH and / or cold water KW from an external cold water supply KH.

The hot water hose 13, the cold water hose 15 and / or the common inlet hose 17 can be used as safety hoses with an inner water-carrying Pressure hose and an outer Hüllschlauch be formed, wherein between the pressure hose and Hüllschlauch each a leakage water channel for discharging any leak water may be provided. In this case, the connecting piece 16 may be formed so that the leakage channels of the hot water hose 13, the cold water hose 15 and the common inlet hose 17 are interconnected, so that leakage water, which occurs during operation of the dishwasher 1 in the region of the water inlet device 11, via the housing fixed connector 18 is directed into the interior of the dishwasher 1. Here it can be detected by a leak water sensor, not shown, so that appropriate measures, such as closing the hot water valve 12 and cold water valve 14, can be initiated.

The dishwasher 1 also has in FIG. 1 components not shown, which make it possible to direct the absorbed water WW, KW from the outlet of the housing-fixed connector 18 in the washing chamber 6. It is expediently provided that the recorded water WW, KW is first performed via a water treatment device, not shown for processing the recorded water WW, KW and / or a heat exchanger for preheating the recorded water WW, KW, before it enters the washing chamber 6 ,

At a bottom 20 of the washing container 4, a collecting pot 21 is formed, in which collects the introduced into the washing chamber 6 water WW, KW due to its gravity. The collecting pot 21 stands in connection with a circulating pump 22, with the aid of which an introduced water WW, KW comprehensive rinsing fluid S can be pumped from the collecting pot 21 via a heater 23 to a water separator 24.

The circulating pump 22, the heating device 23 and the water diverter 24 are controlled by the control device 2 during operation of the dishwasher 1.

The circulation pump 22 preferably has a brushless electric motor, preferably a brushless permanent magnet motor, which serves as a DC motor, an AC motor or synchronous motor can be formed. The rotor of a brushless permanent magnet motor comprises at least one permanent magnet, whereas the stator has a plurality of electromagnets. These electromagnets are commutated via a control electronics. About the control electronics, the direction of rotation of the permanent magnet motor can be clearly defined, so that the water-carrying parts of the circulation pump 22 can be fluidly optimized with respect to a designated direction of rotation. This results in a high flow rate with low energy consumption. In addition, the speed of the motor and thus the delivery rate of the circulation pump 22 can be controlled as needed by means of the control electronics. Furthermore, the brushless permanent magnet motor can be designed as a wet rotor, so that elaborate sealing measures are eliminated.

The heater 23 is provided for heating rinse S and designed as a continuous heating 23. Alternatively or additionally, an openly arranged heating element, for example a heating element arranged in the rinsing chamber 6 or in the collecting pot 21, could also be provided.

The water switch 24 allows a controlled forwarding of the supplied from the circulation pump 22 rinse water S. It has in the embodiment of two outputs, of which a first with an upper rotatable spray arm 25 and a second with a lower rotatable spray arm 26 is connected. The spray arms 25 and 26 form a spraying device 25, 26 arranged in the washing chamber 6, which makes it possible to apply wash liquor S to the wash ware. But it could also be provided other outputs, for example, to allow the feeding of other spray arms or fixed spray elements. The water diverter 24 is controllable such that the rinsing liquor S conveyed by the circulation pump 22 is selectively conveyed into the rinsing chamber 6 by none of the spray arms 25, 26, by one of the spray arms 25, 26 or by both spray arms 25, 26.

In order to control the heater 23 as needed, a temperature sensor 27 is further provided, which is designed to detect the temperature of the recirculation pump circulated by de circulating 22 S rinse. The temperature sensor 27 is arranged in the collecting pot 21 in the exemplary embodiment. He could, however, also be provided elsewhere, where a thermal contact with the circulating water WW, KW is possible.

The dishwasher 1 may further comprise a metering device 28, which is arranged for example on the inside of the door 5. The metering device 28 can be controlled by the control device 2 and makes it possible for the wash liquor S to be automatically supplemented with cleaning agents and / or cleaning auxiliaries, for example rinse aid, during a wash cycle. Furthermore, the dishwasher 1 comprises a drain pump 29, with the aid of which no longer required wash liquor S can be pumped out of the collecting pot 21 via a waste water connection 30 as wastewater AW. The sewage connection 30 can be connected to an external sewage disposal plant with a sewage hose (not shown).

The function of the dishwasher 1 is now the following: First, the operator opens the door 5 and loads the baskets 7, 8 with items to be washed. Then he selects on the operating device 3 a wash program and starts it. Then, the control device 2 takes over the control of a wash cycle based on the activated wash program. The wash program provides for at least one wash step, in which the items to be washed are sprayed with a wash liquor S in order to treat the items to be washed.

At the beginning of such a rinsing step, the hot water valve 12 is opened in a first phase of a water intake phase in order to introduce hot water WW into the rinsing chamber 6 of the dishwasher 1. The thus recorded hot water WW collects at the bottom 20 of the washing compartment 4 and runs there by its gravity into the collecting pot 21. The collecting pot 21 is associated with a temperature sensor 27, which is now in thermal contact with the hot water WW.

In order to prevent erroneous measurement of the temperature of the hot water WW taken, which may be caused by the fact that the recorded hot water WW has an inhomogeneous temperature distribution, the hot water WW is circulated during the first phase as recirculation flow US. On in this way, the hot water WW located in the dishwasher 1 is mixed. When the hot water WW has been circulated for a sufficient time, the temperature of the hot water WW can be measured with the temperature sensor 27 and the measured value used to control the water inlet device 11 in a subsequent second phase of the picking up phase.

The recirculation flow US is generated by hot water WW pumped out of the collection pot 21 by means of the circulation pump 22 and pumped via the heater 23 and the water separator 24 to the lower spray arm 26. The circulation flow US is in FIG. 1 represented by drawn lines. The heater 23 is turned off during the first phase of the water absorption phase, so that the measurement of the temperature of the hot water WW is not disturbed.

During the first phase of the water absorption phase, the circulation pump 22 is operated at such a low rotational speed that the hot water WW exiting at an upper side of the spray arm 26 reaches the lower dish basket 8 only slightly or not at all. This ensures that the items to be washed during the first phase of the water absorption phase is hardly or not at all acted upon by hot water WW in an inadmissible manner, but remains largely unsprayed by hot water too largely dry in particular. As a result, damage to the items to be washed is prevented by a too high temperature even if the recorded hot water WW has a temperature which is significantly higher than the temperature provided for the respective rinsing step.

Since the upper spray arm 25 is hardly or not at all acted upon by hot water WW by a corresponding control of the water switch 24 during the first phase of the water absorption phase, there is also no risk that warm water dripping down from an upper region of the wash chamber 6 will be present in the lower dish rack 8 could be damaged.

When the first phase of the water absorption phase is completed, the control device 2 can calculate whether and how much cold water KW and how much hot water WW are taken up for the respective rinsing step should. In this case, it is possible to use the experience that household-standard cold water supplies KH provide cold water KW with a relatively small fluctuation range of the temperature of the cold water KW. It would also be possible to additionally measure the temperature of the cold water KW.

When the temperature of the hot water WW is above the intended temperature of the wash liquor S, both cold water KW and hot water WW are recorded in the remaining intake phase. As a result, the resultant temperature inside the dishwasher 1 can decrease until it corresponds to the intended temperature for the rinsing liquor S. When the intake of cold water KW is completed, the rotational speed of the circulation pump 22 can be heard, so that the rinsing fluid S now exits the lower spray arm 26 at a higher speed. The rinse liquor S can then treat the dishes located in the dish rack 8. By appropriate control of the water gate 24 is also ensured that in the Besprühphase rinse S at least temporarily exits from the upper spray arm 25 and so can handle the dishes located in the upper dish rack 7. The water switch 24 may be controlled so that the water alternately exits from the lower and the upper spray arm or simultaneously from both spray arms 25, 26. The outlet of the wash liquor S from the spray arms 25, 26 is shown by dotted arrows.

If, on the other hand, the temperature of the hot water WW is lower than the temperature intended for the wash liquor S, hot water WW, but not cold water KW, will continue to be received after the first phase of the water absorption phase. The speed of the circulation pump 22 can be increased in this case immediately after the first phase of the water absorption phase, ie after the measurement of the temperature of the hot water WW, as damage to the items to be washed by excessive temperatures is not to be feared. By early spraying of the items to be washed, the duration of the rinsing step can be reduced in this case, since ultimately the treatment of the items begins earlier. In order to bring the wash liquor S now to the intended temperature, the heater 23 is turned on accordingly. Nevertheless, their electrical energy requirement is minimized, since the already too low temperature of the hot water WW not further lowered by the intake of cold water KW. In an end phase of the rinsing step, the spent rinse liquor S can then be pumped out as wastewater AW by means of the drain pump 29 via the wastewater connection 30 to the outside.

FIG. 2 shows the timing of an exemplary rinse SG according to a method of the invention in an inventively designed dishwasher 1.

On a common time axis t, a curve Z12 shows the operating state of the hot water valve 12, a curve Z14 the operating state of the cold water valve 14, a curve Z22 the operating state of the circulation pump 22, a curve Z23 the operating state of a heater 23, a curve Z24 the operating state of the water switch 24th and a curve T is the actual temperature of the rinse liquor S present in the dishwasher 1. The rinse cycle SG controlled by a rinse program comprises a pre-rinse cycle VG, a cleaning cycle RG, a rinse cycle KG and a drying cycle TG. Here, the items to be washed during the pre-wash VG, during the cleaning cycle RG and during the rinse cycle KG treated with rinse S. In the initial pre-wash VG is initially a recording phase A1, A2 for receiving water, namely for receiving hot water WW and / or cold water KW, provided.

The recording phase A1, A2 comprises a first phase A1, during which a measurement of the temperature of the hot water WW is provided. For this purpose, the hot water valve 12 is brought into an open state "1", so that an inflow of hot water WW takes place in the washing chamber 6. In this case, the circulation pump 22 is turned on and operated at a low speed, which in FIG. 2 is represented by taking the operating state "1". The water switch 24 is controlled so that the circulated hot water WW is supplied only to the lower spray arm 26. Such a control of the circulation pump 22 and the water diverter 24 ensures that the hot water WW circulated during the first phase A1 hardly or not at all impacts the items to be washed in the rinsing chamber 6. Nevertheless, the hot water WW is in a closed circulating flow US circulated so that temperature fluctuations within the hot water WW are compensated. In this way, by means of the temperature sensor 27, a meaningful measured value with respect to a temperature TW of the hot water WW can be determined. Such a measured value is available at the end of the first phase A1 and can be used by the control device 2 to further control the pre-wash cycle VG, in particular to control the remaining second phase A2 of the intake phase A1, A2.

In the example of FIG. 2 the temperature TW of the hot water WW determined in this way is higher than a setpoint temperature TS for the wash liquor S provided for the pre-wash cycle VG. At the same time, the temperature TK of the cold water KW is substantially lower than the setpoint temperature TS. From the measured temperature TW of the hot water WW, from the assumed assumed temperature TK of the cold water KW, from the amount of already taken hot water WW and from the total required amount of water can now be calculated, which amount of cold water KW and what amount of additional hot water WW during the remaining second phase A2 of the recording phase A1, A2 must be supplied to bring the self-adjusting temperature T to the setpoint TS.

The appropriate amounts of hot water and cold water are then absorbed by an appropriate control of the hot water valve 12 and the cold water valve 14. In the example of FIG. 2 In this case, the hot water valve and the cold water valve 12, 14 are simultaneously opened during the second phase A2, which is symbolized in each case by the fact that the curves Z12 and Z14 have the value "1" at the beginning of the second phase A2. However, it could also be provided that the intake of cold water and the additional intake of hot water is carried out sequentially. In the illustrated case, however, the time duration of the recording phase A1, A2 can be minimized overall.

In the example of FIG. 2 During the second phase A2 of the intake phase A1, A2, the actual temperature of the wash liquor S initially drops slowly, since both hot water DHW and cold water KW are taken up. When the required amount of cold water KW is received, the hot water valve 12 is closed again, so that the curve Z12 assumes the value "0". Now only further cold water KW is taken, so that the temperature T of the rinsing S further drops. At the end of the recording phase A1, A2 and the cold water valve 14 is closed. At this time, the rinsing liquor S reaches its setpoint temperature TS. Depending on the temperature TK, the cold water KW, the temperature of the hot water WW and the target temperature of the wash liquor, of course, cases may arise in which first the cold water valve 14 and then the hot water valve 12 is closed.

When the wash liquor S has reached the intended setpoint temperature TS, the spraying phase B can be initiated during which the washware is treated with wash liquor S. For this purpose, the rotational speed of the circulation pump 22 is increased to its intended rated speed, which is illustrated by taking the operating state "2". The water switch 24 is controlled so that alternately the lower spray arm 26 and the upper spray arm 25 is supplied with wash liquor S, which is represented by the alternate assumption of the operating states "1" and "2". After completing the spraying phase B, the circulation pump 22 can be switched off, the alternating activation of the water separator 24 is ended and the spent washing liquor S is pumped out.

The subsequent cleaning cycle RG and the subsequent rinse cycle KG are carried out according to the same flow chart. It goes without saying that, for the cleaning cycle RG and / or for the rinse cycle KG, another, in particular a higher setpoint temperature TS for the rinsing liquor S could be provided. In the final drying cycle TG, the drying of the items to be washed takes place, for example according to the principle of self-drying outlined above.

FIG. 3 shows the basic sequence of a wash cycle SG, when the temperature TW of the hot water WW is lower than the target temperature TS of the wash liquor S. This is, as the example of FIG. 2 explains, a recording phase A1, A2 performed, wherein the temperature T of the wash liquor S during the first phase A1 is measured. Due to the present at the end of the first phase A1 value of the temperature TW of the hot water WW is the further absorption of water during the second phase A2 of the recording phase A1, A2 compared to the example of FIG. 2 changed. Thus, during the second phase A2, only further hot water WW is taken in order to prevent the average temperature of the total absorbed water from falling further. Since it is determined at the end of the first phase A1 that the temperature TW of the hot water WW is below the target temperature TS for the wash liquor S, the spray phase B can be initiated immediately after completion of the first phase A1. In order to bring the rinsing fluid S to the intended temperature TS, the heating device 23 is switched on temporarily during the spraying phase B, so that the curve Z23 temporarily assumes the value "1". In this case, the heater 23 expediently be turned on immediately at the beginning of Besprühphase B. The timing of turning off the heater 23 may be determined by the temperature sensor 27.

In an advantageous embodiment of the invention, a dishwasher for saving energy in addition to its cold water connection to an external hot water supply is connected, which is fed in particular by the heat energy of a solar system partially or completely. Since the inlet temperature of the hot water from the external hot water supply system is not known for the time being, a small amount of hot water in the dishwasher, in particular filled their liquid system, circulated through the circulation pump at low speed and thereby measured via an NTC temperature. Depending on the inlet temperature and the selected program, hot and / or cold water is then fed in via a bithermic Aquastop water inlet device, thus achieving the temperature specified in the program. This prevents an excessively high temperature from setting in the device and damaging the dishes. This advantage can be realized in various washing programs, for example in a fine program or gentle program and / or in a quick program.

LIST OF REFERENCE NUMBERS

1

dishwasher

2

control device

3

operating device

4

rinse tank

5

door

6

rinsing chamber

7

upper dish rack

8th

lower crockery basket

9

out rail

10

out rail

11

Water inlet device

12

Hot water valve

13

Hot water hose

14

Cold water valve

15

Cold water hose

16

joint

17

inlet hose

18

fixed housing

19

casing

20

Bottom of the washing container

21

collecting pot

22

circulating pump

23

heater

24

water points

25

upper spray arm

26

lower spray arm

27

temperature sensor

28

metering

29

Drain pump

30

Waste water connection

KW

cold water

WW

hot water

S

rinsing

US

recycle stream

AW

sewage

KH

Cold water supply, cold water tap

WH

Hot water supply, hot water tap

TSA

Thermal solar system

SOK

solar panel

WT

heat exchangers

ZH

additional heating

SG

rinse

VG

prewash

RG

cleaning cycle

KG

rinse cycle

TG

drying cycle

A1

first phase of the admission phase

A2

second phase of the admission phase

B

Besprühphase

Z12

Operating status of hot water valve

Z14

Operating state cold water valve

Z22

Operating condition of circulating pump

Z23

Operating state heating device

Z24

Operating condition of water separator

TW

Temperature of the hot water

TK

Temperature of the cold water

T

Actual temperature of the rinsing liquor

TS

Target temperature of the rinsing liquor

Claims (9)

1. Dishwashing machine, in particular a domestic dishwashing machine (1), comprising a control device (2), in which at least one wash program is stored for controlling a wash cycle (SG) for cleaning items to be washed, and comprising a water inlet device (11) which has a hot-water valve (12) which can be controlled by the control device (2) and a cold-water valve (14) which can be controlled by the control device (2), wherein the hot-water valve (12) is provided for taking in hot water (WW) from an external hot-water supply (WH), in particular from a hot-water supply (WH) fed at least in part by a thermal solar installation (TSA), and the cold-water valve (14) is provided for taking in cold water (KW) from an external cold-water supply (KH), and wherein the at least one wash program provides at least one wash step (VG, RG, KG), which comprises an intake phase (A1, A2) for taking in water (WW, KW) via the water inlet device (11) and a spraying phase (B) for spraying items to be washed located in a washing chamber (6) with a washing liquor (S) containing water (WW, KW) which has been taken in, wherein the at least one wash program provides a first phase (A1) of the intake phase (A1, A2), during which an intake of hot water (WW) is effected via the hot-water valve (12) and during which a measurement of a temperature (TW) of the hot water (WW) which has been taken in is effected by means of at least one temperature sensor (27) arranged downstream of the water inlet device (11), characterised in that the hot water (WW) is circulated during the first phase (A1) of the intake phase (A1, A2) by means of a circulation pump (22) controlled by the control device (2) and a rotational speed of the circulation pump (22) is controlled such that this is lower than during the spraying phase (B) .
2. Dishwashing machine according to one of the preceding claims, characterised in that the at least one wash program provides a second phase (A2) of the intake phase (A1, A2), during which control of the water inlet device (11) is effected on the basis of the measured temperature (TW) of the hot water (WW).
3. Dishwashing machine according to claim 2, characterised in that during the second phase (A2) of the intake phase (A1, A2) an intake of hot water (WW) and of cold water (KW) is provided if the temperature (TW) of the hot water (WW) is greater than an intended temperature (TS) of the washing liquor (S) for the wash step (VG, RG, KG).
4. Dishwashing machine according to one of claim 2, characterised in that during the second phase (A2) of the intake phase (A1, A2) an intake of hot water (WW), but not of cold water (KW), is provided if the temperature (TW) of the hot water (WW) is less than or equal to the intended temperature (TS) of the washing liquor (S) for the wash step (VG, RG, KG).
5. Dishwashing machine according to one of the preceding claims, characterised in that the first phase (A1) of the intake phase (A1, A2) precedes the spraying phase (B).
6. Dishwashing machine according to one of the preceding claims, characterised in that the spraying phase (B) is provided after the intake of a quantity of cold water (KW) determined on the basis of the temperature (TW) of the hot water (WW), if the temperature (TW) of the hot water (WW) is greater than an intended temperature (TS) of the washing liquor (S) for the wash step (VG, RG, KG).
7. Dishwashing machine according to one of the preceding claims, characterised in that the hot water (WW) is circulated during the first phase (A1) of the intake phase (A1, A2) in that it is pumped out of a collection sump (21) of the washing chamber (6) by means of a circulating pump (22) controlled by the control device (2) and is returned into the collection sump (21) via a spray device (25, 26) arranged in the washing chamber (6) such that the items to be washed positioned in the washing chamber (6) remain untouched by the circulated hot water (WW).
8. Dishwashing machine according to one of the preceding claims, characterised in that the spray device (25, 26) has several spray elements (25, 26) which can be individually connected via a water diverter (24) to the circulating pump (22), wherein the water diverter (24) is controlled such that during the first phase (A1) of the intake phase (A1, A2) the hot water (WW) is returned into the collection sump (21) substantially via a spray element (26) arranged in a lower area of the washing chamber (6).
9. Method for executing a wash cycle (SG) with a dishwashing machine (1), in particular with a dishwashing machine (1) according to at least one of the preceding claims, said machine comprising a water inlet device (11) for taking in water (WW, KW), wherein the water inlet device (11) is connected, for taking in hot water (WW), to an external hot-water supply (WH), in particular to a hot-water supply (WH) fed at least in part by a thermal solar installation (TSA), and, for taking in cold water (KW), to an external cold-water supply (KH), wherein at least one wash step (VG, RG, KG) is executed in which in an intake phase (A1, A2) water (WW, KW) is taken in via the water inlet device (11) and in a spraying phase (B) items to be washed located in a washing chamber (6) are sprayed with a washing liquor (S) containing water (WW, KW) which has been taken in, wherein during a first phase (A1) of the intake phase (A1, A2) hot water (WW) is taken in and the temperature (TW) of the hot water (WW) which has been taken in is measured by means of at least one temperature sensor (27) which is arranged downstream of the water inlet device (11), characterised in that the hot water (WW) is circulated during the first phase (A1) of the intake phase (A1, A2) by means of a circulation pump (22) controlled by the control device (2) and a rotational speed of the circulation pump (22) is controlled such that this is lower than during the spraying phase (B) .

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