EP2489295B1 - Dishwasher with a rotation monitoring unit and method for operating the same - Google Patents

Description

The invention relates to a dishwasher, in particular a domestic dishwasher, with a washing chamber for receiving items to be washed, with an inlet through which the washing liquid can flow into the dishwasher, with an inlet valve, via which the amount of the incoming washing liquid can be regulated, with a measuring device, with whose help the amount of washing liquid flowing into the dishwasher and / or the position of the inlet valve can be determined, with a circulating pump for circulating the washing liquid flowing in within the dishwasher, and with a control / regulating device, the control / regulating device being designed that To regulate the amount of washing liquid flowing into the dishwasher by activating the inlet valve and wherein the control / regulating device comprises a concentricity monitoring unit, with the aid of which a concentricity check of the circulating pump can be carried out. In addition, a method for operating a dishwasher, in particular a domestic dishwasher, with a washing chamber for receiving items to be washed, with an inlet via which washing liquid can flow into the dishwasher, with an inlet valve, via which the amount of washing liquid flowing in is regulated a measuring device, with the aid of which the amount of washing liquid flowing into the dishwasher and / or the position of the inlet valve can be determined, with a circulating pump for circulating the washing liquid within the dishwasher, and with a control / regulating device, the control / regulating device being proposed. Control device is designed to regulate the amount of washing liquid flowing into the dishwasher by activating the inlet valve and wherein the control / regulating device comprises a concentricity monitoring unit, with the aid of which a concentricity check of the circulating pump can be carried out.

In the prior art, it is known to fill dishwashers with washing liquid, in particular fresh water, in order to finally enable washing ware to be cleaned with the aid of this washing liquid, possibly provided with cleaning agents and / or other additives. To monitor the amount of washing liquid flowing into the dishwasher at the beginning of the washing program or during operation, a measuring device such as an impeller meter is conventionally provided, with the aid of which the amount of washing liquid flowing into the dishwasher and / or the position of the inlet valve can be determined. A corresponding dishwasher is for example in the DE 10 2008 021 371 B3 described.

The object of the invention is to propose a dishwasher and a method that allow reliable filling with washing liquid, even if the measuring device, with the help of which the amount of washing liquid flowing into the dishwasher and / or the position of the inlet valve in normal operation, ie when it is functional Measuring device, is determined, is no longer or no longer fully functional.

The object is achieved in terms of device with a dishwasher according to independent claim 1.

The dishwasher according to the invention has a control / regulating device, i.e. a control device for automatically carrying out operating sequences of the dishwasher. For this purpose, the control / regulating device can be designed as a so-called sequence controller, in particular as an electronic sequence controller.

At least one wash program for performing or controlling a wash process, also called a wash cycle, for washing items to be washed, in particular for washing dishes, is stored in the control / regulating device. A plurality of washing programs are advantageously provided, one of which can be selected and started by the operator. This makes it possible to adapt the sequence of a wash cycle, in particular to the load quantity, to the type of load, to the degree of soiling of the items to be washed and / or to the desired duration of the wash cycle.

The stored wash programs can preferably be designed in such a way that the wash cycle controlled by them, in particular, has at least one pre-wash cycle for pre-cleaning wash ware, at least one cleaning cycle for thorough cleaning of wash ware, at least one intermediate wash cycle for removing contaminated washing liquid from the wash ware, at least one final rinse cycle for avoidance of stains on the items to be washed and / or in preparation for a drying cycle, and / or at least one Includes drying cycle for drying the items to be washed. The pre-wash cycle, cleaning cycle, intermediate wash cycle and final rinse cycle are referred to as water-bearing partial wash cycles, since the wash items brought into the wash chamber are treated with a washing liquid while they are being carried out. The use of rinsing liquid is generally not intended during the drying process.

The items to be washed are treated with washing liquid in an essentially closed washing chamber, in particular a washing container, of the dishwasher. The rinsing chamber is assigned an inlet valve which enables rinsing liquid to be poured into the rinsing chamber, the inlet valve being able to be opened and closed by the control / regulating device in order to influence the inlet of rinsing liquid.

A washing liquid is understood here in particular as a liquid which is intended to be applied to the items to be washed in order to clean them and / or treat them in another way. For example, the rinsing liquid can also be provided for heating the items to be washed, which is customary, for example, during a final rinse step.

The rinsing liquid flowing into the rinsing chamber via the inlet valve is usually fresh water. The washing liquid in the washing chamber can be enriched with cleaning agents, with cleaning aids, such as rinse aid, and / or with dirt that has been loosened from the items to be washed, depending on the operating phase of the dishwasher. However, cases are also conceivable in which already enriched water, which is temporarily stored in a storage tank, for example, is poured into the washing chamber as washing liquid via the inlet valve.

Furthermore, the washing chamber is assigned a typically electrically driven circulating pump for circulating the washing liquid that has been filled in, which makes it possible to remove the washing liquid in the washing chamber, for example, from a collection device for washing liquid and to apply it to the items to be washed via a spray system assigned to the washing chamber. The speed of the circulating pump can be variably controlled and / or regulated by the control / regulating device of the dishwasher.

The dishwasher also includes a run-out monitoring unit for performing a run-out check of the circulating pump. The concentricity monitoring unit can be viewed as a component of the control / regulating device, since the results of concentricity tests can be used to influence operating processes, in particular washing cycles, of the dishwasher. At least during the concentricity check, a power signal fed to the concentricity monitoring unit is usually monitored and / or evaluated, which signal can in particular be a signal which corresponds to the current consumption of the circulating pump.

A circulating pump is generally running smoothly when there is sufficient washing liquid in the collecting device of the washing chamber to prevent air being sucked in by the circulating pump. Whether or not air is sucked in in an individual case depends in particular on the one hand on the amount of wash liquid in the wash chamber and on the other hand on the speed of the circulating pump. The reason for this is that as the speed of the circulating pump increases, an ever smaller part of the total washing liquid present in the washing chamber is in the collecting device, since it takes a certain time for the washing liquid sprayed onto the items to be washed back into the collecting device.

Finally, the dishwasher includes a measuring device with the aid of which the amount of washing liquid flowing into the dishwasher via the feed valve and / or the position of the feed valve can be determined. The measuring device can include, for example, an impeller sensor, the movable wing element of which is integrated into the feed line of the dishwasher and generates signals as soon as washing liquid flows into the washing chamber via the feed line. Pressure or liquid level sensors can also be used. The only prerequisite for such sensors is that they are suitable for qualitatively and / or quantitatively detecting an inflow of washing liquid into the dishwasher. In any case, the measuring device serves to monitor the liquid flowing into the dishwasher during normal operation of the dishwasher, in which all components function properly. With the inlet valve open, this always gets into the dishwasher when the washing program provides for a (new) filling of the same, for example at the beginning of a water-carrying partial wash cycle of the respective selected dishwashing program, or after a corresponding pumping process. A washing liquid supply can also be necessary during operation of the dishwasher if only part of the washing liquid is pumped out with the aid of the drain pump, for example as part of a cleaning step of a washing liquid filter system. If the measuring device is now defective, it was customary according to the prior art to stop the washing program, since it can no longer be determined with certainty whether or when the amount of washing liquid required for operating the dishwasher has flowed into the dishwasher.

According to the invention it is now provided that the control / regulating device is designed to check the functionality of the measuring device, with the help of which the amount of washing liquid flowing into the dishwasher and / or the position of the inlet valve can be determined, at least when the inlet valve is open and the inlet valve in In the event of a malfunction of the measuring device, depending on the results of the concentricity test.

The inventive construction of the dishwasher makes it possible in a simple manner to control the inlet valve as a function of the measuring device even if the measuring device is defective (for example if the power and / or data lines connected to the measuring device are damaged or one or more components of the measuring device have a hardware defect) to enable the amount of washing liquid that has flowed into the dishwasher or is already present therein. In this case, the inlet valve opened by the control / regulating device is no longer closed as a function of the measured values of the measuring device. Rather, the closing takes place after it has been recognized with the help of the concentricity monitoring device that the circulation pump is running in concentricity, since this is a sign that sufficient washing liquid has run into the dishwasher. As a result, it is finally ensured that the dishwasher can continue to be operated reliably even in the event of a malfunction of the measuring device, without the cleaning or drying function being influenced. In this context, it should finally be mentioned that the closing of the inlet valve can also be initiated before the circulating pump is finally running, ie when a certain load value or a characteristic load profile for the circulating pump is detected by means of the concentricity monitoring unit. For example, it would be conceivable that the inlet valve is already closed, if the concentricity monitoring device detects that washing liquid has run into the dishwasher (because, for example, the power requirement of the circulating pump increases), however, complete concentricity cannot yet be determined. This would also be conceivable, for example, in the event that additional washing liquid is fed into the dishwasher from an additional container arranged in the wall of the dishwasher, so that the total amount of washing liquid required for the washing program is available to ensure that the circulating pump runs smoothly.

According to a first alternative of the invention, the control / regulating device is designed to close the inlet valve as soon as the concentricity test shows that the circulating pump is in concentricity. In this embodiment, the inflow of the washing liquid is finally controlled in such a way that the amount of washing liquid is just sufficient to ensure the desired concentricity. In this way, with the aid of the concentricity monitoring device, the amount of washing liquid filled can be automatically adapted to the actual need for washing liquid, in particular depending on the load of washing items. For example, the amount of washing liquid that has been filled in, which adheres to the wash ware due to the type and amount of wash ware, is automatically taken into account, since the filling valve is only closed when the amount of wash liquid available for circulation, i.e. the total amount minus the adhering amount, is sufficient to prevent the circulation pump from sucking in air. In this way, the consumption of rinsing liquid can be minimized and an intended cleaning effect can still be ensured.

According to a further alternative of the invention, the control / regulating device is designed to close the inlet valve after a defined period of time has passed from the point in time at which the concentricity test shows that the circulating pump is in concentricity. This means that, compared to the previous example, an additional amount of washing liquid gets into the dishwasher. Any additional liquid that may later collect on the items to be washed (for example, items that have been tipped over during the wash program, for example a bowl) does not in this case directly result in the circulation pump sucking in air.

According to an advantageous development of the invention, the concentricity monitoring unit is designed to carry out the concentricity check on the basis of the power consumption or the power consumption of the circulation pump. This is due to the fact that the flushing liquid has a higher flow resistance than the air previously present in the circulation pump. As soon as the circulating pump is finally running, the stated amounts finally stagnate, so that the fill level of the circulating pump can be precisely monitored by evaluating the stated physical variables on the part of the control / regulating device.

According to an advantageous development of the invention, the circulation pump comprises a brushless electric motor, which can be designed as a brushless DC motor, also called BLDC motor, or as a brushless AC motor, also called BLAC motor. The rotor of the electric motor comprises at least one permanent magnet, whereas the stator has several electromagnets. The electromagnets are commutated via control electronics, in particular via a frequency converter. In comparison to other possible motor concepts, this allows both the direction of rotation and the speed of the motor to be controlled in a simple manner. By operating the motor in exactly one direction of rotation, it is also possible to optimize the flow of the water-carrying parts of the circulation pump. This results in a high delivery rate with little use of energy. Furthermore, the brushless permanent magnet motor can be designed as a wet rotor, so that complex sealing measures are not required. Finally, both the BLAC motor and the BLDC motor have the advantage that the connection with the control / regulating device can be used to determine how high the current power consumption or the current power consumption of the motor is. As soon as the circulation pump comes into contact with the washing liquid while it is flowing in, these values rise so that it can be recognized on their basis when washing liquid is flowing into the dishwasher. Finally, the values mentioned reach a maximum value when the circulating pump is running, since from this point in time no more air is sucked in, and the flow resistance within the pump is therefore maximum.

According to an advantageous development of the invention, the control / regulating device is designed, the functionality of the measuring device on the basis of the power consumption or the power consumption of the measuring device. This is always useful when active, ie power-consuming, measuring devices are used. If one of the mentioned measured values drops to an unusually low value or even to zero, this is usually a sign that the measuring device is no longer working correctly.

According to an advantageous development of the invention, the control / regulating device is designed to check the functionality of the measuring device on the basis of the comparison of the measured values of the measuring device with the result of the concentricity test. For example, there is a malfunction if the measured value device does not provide any measurement results indicating the inflow of washing liquid, although the concentricity check shows that the circulating pump is at least partially flooded with washing liquid.

According to an advantageous development of the invention, the control / regulating device is designed to check the functionality of the measuring device by comparing the measured values of the measuring device with the desired position of the inlet valve. Since the inlet valve is usually activated by the control / regulating device, there is always a setpoint value for the position of the inlet valve (setpoint position) in the control / regulating device, either "valve open" or "valve closed" (conceivable Of course, there would also be corresponding intermediate positions in which the volume flow of the inflowing rinsing liquid is correspondingly throttled). If a signal has now been sent to the inlet valve, which results in the opening of the same, then the measuring device should also send a signal to the control / regulating device that indicates an inflow of rinsing liquid. If this is not the case, although the desired position in the control / regulating device signals an open inlet valve, this is a sign that the measuring device is not working properly.

According to an advantageous development of the invention, the control / regulating device is designed to close the inlet valve in the event of a malfunction of the measuring device as a function of the time after it has been closed as a function of the results of the concentricity test and reopened for the additional inflow of flushing liquid. In this case it is conceivable, for example, that the filling of the dishwasher with washing liquid, which is necessary at the beginning of each washing program, takes place on the basis of the concentricity monitoring of the circulation pump. Used in the course of the washing program Finally, some of the washing liquid is removed from the dishwasher by the drain pump, so it may be necessary at a later point in time to feed an additional amount of washing liquid into the dishwasher. For this purpose, the inlet valve is opened and closed again after a certain time, which corresponds to a corresponding amount of flushing liquid. In this case, the concentricity monitoring is only used when the dishwasher is filled for the first time or when the washing water is changed completely later, in order to monitor the amount of the washing liquid flowing in.

According to an advantageous further development of the invention, the control / regulating device is designed to operate the dishwasher according to a wash program, in particular selectable by an operator, which includes several wash cycles, for example in the form of a pre-wash cycle, a cleaning cycle, an intermediate wash cycle, a rinse cycle and / or a drying cycle, and wherein the control / regulating device is designed to skip at least one of the rinsing cycles, to modify it and / or to replace it with an alternative rinsing cycle in the event of a malfunction of the measuring device. Thus it is usually not possible with the help of the concentricity monitoring device to detect a further increase in liquid after the concentricity, since the flow resistance within the circulation pump no longer increases as soon as the circulation pump is completely filled. If the rinsing water supply is now stopped as soon as the circulating pump is operated in rotation, only a very specific amount of rinsing liquid is also present in the dishwasher. If this amount is less than in the normal case, in which the amount can assume almost any amount due to the measuring device, then in the event of a malfunction of the measuring device it would be advisable to extend the cleaning phase, for example, in order to achieve a satisfactory wash result.

According to an advantageous development of the invention, the control / regulating device is designed to operate the dishwasher according to a washing program that can be selected in particular by an operator and to check the functionality of the measuring device after each start of the washing program, the inlet valve only in the event of a malfunction of the Measuring device is closed depending on the results of the concentricity test and otherwise depending on the measured values of the measuring device. This avoids that the dishwasher after one time Detection of a malfunction of the measuring device is only filled according to the alternative method according to the present invention. Rather, it is ensured that the filling takes place again on the basis of the measured values of the measuring device as soon as it is established that the malfunction of the measuring device has been eliminated.

According to an advantageous development of the invention, the concentricity monitoring unit comprises a filter arrangement with a bandpass behavior for generating a filtered power signal and an evaluation arrangement connected downstream of the filter arrangement for evaluating the filtered power signal. A filter arrangement with bandpass behavior is understood to mean a filter arrangement which allows only one frequency band to pass from an input signal fed to it, that is to say the frequencies in a pass band. Through a suitable choice of the pass band of the filter arrangement, frequency components of the power signal can be blocked or attenuated which are not directly related to whether the circulating pump is running or not. For example, frequency components can be blocked which are typically generated by the control and / or regulating activity of a speed control / regulating device assigned to the circulating pump, and which are typically located in a low frequency range. High-frequency frequency components that can occur, for example, when an electric motor of the circulating pump is commutated, can also be blocked in this way. Since the power signal filtered in this way is now evaluated by the downstream evaluation arrangement, the error susceptibility of the concentricity monitoring unit is considerably reduced. The filter arrangement can, in particular if the power signal is a time-continuous and / or value-continuous signal, be designed as an analog passive filter arrangement which comprises components from the group of coils, capacitors and resistors. However, it can also be designed as an analog active filter arrangement which additionally comprises an amplifier, in particular an operational amplifier. Furthermore, the filter arrangement, in particular if the power signal is a time-discrete and / or value-discrete signal, can be a digital filter arrangement which comprises a digital computer, for example a signal processor or a microprocessor. Especially when the power signal fed to the filter arrangement is a time-discrete and / or value-discrete signal, in particular if it is a time-discrete and value-discrete digital signal, the advantages of the described development of the invention are particularly evident. So in this case in the power signal contained frequency components are suppressed, which arise due to the temporal sampling of an initially analog signal that corresponds to the power and / or the quantization of the values of the initially analog signal. This effect is particularly important when the analog signal is sampled at a constant sampling rate and the circulating pump is operated in a high speed range, since the sampling errors are higher the less frequently the analog signal is sampled per revolution of the circulating pump. The invention thus ensures reliable true running detection even in the upper speed range of the circulating pump, in particular at its intended maximum speed.

The method according to the invention for operating a dishwasher, in particular a domestic dishwasher, is finally characterized in that the functionality of the measuring device is checked with the aid of the control device at least when the inlet valve is open and the inlet valve is closed in the event of a malfunction of the measuring device depending on the results of the concentricity test , reference being made to the previous description with regard to the advantages. According to the invention, the

Control / regulating device the inlet valve as soon as the concentricity test shows that the circulation pump is in concentricity. This results in an operation of the dishwasher that is particularly advantageous from an ecological and economic point of view, since only as much washing liquid flows into the dishwasher as is actually required to ensure that the circulating pump runs smoothly.

According to an advantageous development of the invention, the functionality of the measuring device is checked after each start of the wash program and the inlet valve is closed only in the event of a malfunction of the measuring device depending on the results of the concentricity test and otherwise depending on the measured values of the measuring device. As already mentioned, this ensures that the dishwasher is only filled in accordance with the solution according to the invention when there is actually a malfunction of the measuring device.

The advantageous embodiments and developments of the invention explained above and / or reproduced in the subclaims can - except z. B. in the cases clear dependencies or incompatible alternatives - can be used individually or in any combination with one another.

Figur 1

ein Ausführungsbeispiel einer erfindungsgemäßen Haushaltsgeschirrspülmaschine in einer schematischen Seitenansicht,

Figur 2

eine alternative Darstellung der Geschirrspülmaschine der Figur 1, und

Figur 3

ein Ablaufdiagramm eines Teils eines Spülprogramms umfassend das erfindungsgemäße Verfahren.

The invention and its advantageous designs and developments as well as their advantages are explained in more detail below with reference to drawings. It shows, each in a schematic sketch:

Figure 1

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

Figure 2

an alternative representation of the dishwasher of the Figure 1 , and

Figure 3

a flowchart of a part of a washing program comprising the method according to the invention.

In the following figures, parts that correspond to one another are provided with the same reference symbols. Only those components are provided with reference symbols and explained which are necessary for an understanding of the invention.

Figure 1 shows an advantageous embodiment of a dishwasher 1 according to the invention in a schematic side view. The dishwasher 1 has a control / regulating device 2 or control device in which at least one wash program for controlling a wash cycle for washing items to be washed, in particular dishes, is stored. A number of wash programs are expediently stored so that, by selecting a suitable wash program, the sequence of a wash cycle controlled by the control / regulating device 2 is adapted, for example, to the load quantity, to the type of load, to the degree of soiling of the items to be washed and / or to the desired duration of the wash cycle can be.

The control / regulating device 2 is generally assigned an operating device 3 which allows an operator of the dishwasher 1 to call up one of the washing programs and thereby start it. Furthermore, the control / regulating device 2 can be assigned an output device 4 which enables messages to be output to the operator. The output device 4 can output optical messages Display lamps, light emitting diodes, an alpha-numeric display and / or a graphic display. Furthermore, the output device 4 can have a buzzer, a loudspeaker and / or the like for outputting acoustic messages.

The dishwasher 1 further comprises a washing compartment 5, which can be closed by a door 6, so that a closed washing chamber 7 is created for washing items to be washed. The washing container 5 can optionally be arranged in the interior of a housing 8 of the dishwasher 1. In the case of built-in dishwashers, the housing 8 is not required and can be partially or completely omitted. In Figure 1 the door 6 is shown in its closed position, whereby it can be brought into an open position by pivoting about an axis arranged perpendicular to the plane of the drawing, in which it is oriented essentially horizontally and enables the insertion and removal of items to be washed. In the in Figure 1 The embodiment shown, the operating device 3 is arranged in a user-friendly manner on an upper section of the door 6. The output device 4 is also arranged on the upper section of the door 6, so that optical messages are clearly visible and acoustic messages are clearly audible. In principle, however, it is possible to arrange the operating device 3 and / or the output device 4 at a different location.

The control / regulating device 2 is accommodated, for example, in a base assembly below the washing compartment 5. However, it is also possible to arrange the control / regulating device 2 at another point on the dishwasher 1. The control / regulating device 2 could, however, also be designed in a decentralized manner, which is understood to mean that it comprises spatially separated components which are connected via communication means in such a way that they can interact.

According to an alternative embodiment, the control / regulating device 2 or at least one of its decentralized components can be positioned in the door 6 so that the required signal connections between the operating device 3, the output device 4 and the control / regulating device 2 can be kept short.

The dishwasher 1 has an upper crockery basket 9 and a lower crockery basket 10 for positioning dishes. The upper crockery basket 9 is arranged in particular on extension rails 11, which are each on opposite sides and side walls of the washing container 5 extending in the depth direction of the washing container 5 are attached. When the door 6 is open, the upper crockery basket 9 can be moved out of the washing container 5 by means of the extension rails 11, which facilitates the loading and unloading of the upper crockery basket 9. The lower crockery basket 10 is arranged in an analogous manner, in particular on extension rails 12.

The wash program (s) stored in the control / regulating device 2 can each provide several partial wash cycles, for example at least one pre-wash cycle, at least one cleaning cycle, at least one intermediate wash cycle, at least one rinse cycle and / or at least in this order a drying cycle. The pre-wash cycle, cleaning cycle, intermediate wash cycle and final rinse cycle are referred to as water-carrying partial wash cycles, since the wash items positioned in the wash chamber 7 are treated with a wash liquid S while they are being carried out. Treatment of the items to be washed with washing liquid S is generally not provided during the drying cycle.

In the exemplary embodiment, fresh water or inlet water ZW, which can be taken up by an external water supply device WH, in particular a drinking water supply network, and filled into the washing chamber 7, is used as the washing liquid S for treating the items to be washed. Typically, at the beginning of each water-carrying partial wash cycle, a washing liquid S formed from fresh inlet water ZW is filled in, which is then discharged to an external waste water disposal device AR as waste water AW at the end of the respective partial wash cycle. It is also possible, however, to store a washing liquid S of a wash part in a storage container (not shown) and to fill it again into the wash chamber 7 in a later wash part or a subsequent dishwashing program.

The dishwasher 1 of the Figure 1 comprises an inlet 13, which is provided for connection to the external water supply device WH. As in Figure 1 The external water supply device WH can be a tap of a building-side water installation that provides pressurized inlet water ZW. The inlet 13 comprises a connection piece 14 which is provided for connection to the faucet. The connection can take place, for example, via a thread arrangement, a bayonet arrangement or the like. Downstream of the connection piece 14, a connection hose 15 is provided, which is preferably designed to be flexible. The downstream end of the connection hose 15 is connected to a connection piece 16 which is fixed to the housing.

Downstream of the connector 16 fixed to the housing, a supply line 17 is provided, which is connected to an input side of an inlet valve 18 that can be switched by means of the control / regulating device 2. An outlet side of the inlet valve 18 is in turn connected to a liquid inlet 19 of the rinsing chamber 7. In this way, it is possible, by means of the inlet 13, to conduct inlet water ZW as washing liquid S into the interior of the washing chamber 7 of the dishwasher 1. The inlet valve 18 can be designed as a switchable solenoid valve which only has an open position and a closed position. A water treatment system (not shown), for example a softening system, can be provided in the supply line 17.

Instead of or in addition to the device-side inlet valve 18, an external inlet valve, in particular a so-called aqua-stop valve, can also be provided between the connection piece 14 and the water tap or on the connection piece 14, which can preferably be switched, in particular shut off and opened, by means of the control / regulating device 2 . For this purpose, it is connected to the control / regulating device 2 via one or more control lines. The external inlet valve can, if necessary, be coupled directly to the water tap as an end or connection piece of the water hose 15. The internal inlet valve 18 can advantageously be omitted.

The rinsing liquid S flowing into the rinsing chamber 7 via the liquid inlet 19 arrives due to its weight in a collecting device formed on a base 20 of the rinsing container 5, which can preferably be formed as a collecting pot 21. An input side of a circulating pump 22 is connected to the collecting pot 21 in a fluid-conducting manner. Furthermore, an output side of the circulating pump 22 is connected to a spray device comprising a lower spray arm 24 and an upper spray arm 23, which makes it possible to apply washing liquid S to the items to be washed in the washing chamber 7.

In the exemplary embodiment, the circulation pump 22 has a brushless AC motor, also called a BLAC motor. In principle, however, other motor concepts would also be conceivable, as long as they are suitable for being checked with the help of the concentricity monitoring unit 25 as part of a concentricity test to determine whether they are in concentricity (for the definition of the term concentricity, see the explanations above).

In the embodiment of Figure 1 the spray device comprises an upper rotatable spray arm 23 and a lower rotatable spray arm 24. However, fixed spray elements could also be provided as an alternative or in addition.

The rinsing liquid S exiting the spraying device when the circulating pump 22 is switched on returns to the sump 21 due to its weight within the rinsing chamber 7. While the rinsing liquid S is circulating in the rinsing chamber 7, the aim is to operate the circulating pump 22 in rotation. The circulating pump 22 is then in rotation when such a large amount of flushing liquid S is available here that it only delivers flushing liquid S - or, to put it the other way around - does not convey any air. By operating the circulating pump 22 in rotation, on the one hand, a pump pressure that is sufficient for the intended cleaning effect can be achieved and, on the other hand, the formation of disruptive slurping noises can be avoided. In order to determine whether the circulating pump 22 is running or not, a running monitoring unit 25 is provided. This is integrated into the control / regulating device 2 in the exemplary embodiment. The concentricity monitoring unit 25 could, however, also be designed as a separate module.

According to the present invention, it is now provided that this concentricity monitoring unit 25 is used not only for monitoring the concentricity of the circulating pump 22 and thus also the water level inside the dishwasher 1. Rather, the concentricity monitoring unit 25 also serves to monitor a measuring device 38. Thus, the normal case provides that the amount of washing liquid S flowing into the dishwasher 1 is determined with the aid of a measuring device 38, which is integrated in the supply line 17 in the example shown. For this purpose, the measuring device 38 is designed, for example, as an impeller meter, the measuring signals of which are transmitted to the control / regulating device 2 and are evaluated by the latter. Likewise can about the measuring device 38 also indirectly recognizes the position of the inlet valve 18, since the measuring device 38 only delivers signals when the inlet valve 18 is open. On the other hand, the fact that no signals are supplied by the measuring device 38 normally shows that the inlet valve 18 is closed.

If there is no malfunction of the measuring device, the control / regulating device 2 opens the inlet valve 18 after the start of the washing program, so that washing liquid S can flow into the dishwasher 1, which in turn is circulated by the circulating pump 22. If a sufficient amount of washing liquid S has now flowed into the dishwasher 1, this amount being determined with the aid of said measuring device 38, then the inlet valve 18 is closed again.

If, on the other hand, the measuring device 38 has a malfunction, then no further measured values are supplied to the control / regulating device 2, even if the inlet valve 18 is open. In this case, however, it is now possible to detect the inflow of the rinsing liquid S with the aid of the concentricity monitoring unit 25. If the liquid level rises within the dishwasher 1, the point is finally reached at which the circulating pump 22 comes into contact with the washing liquid S and sucks it in. This increases the power requirement of the electric motor of the circulating pump 22, since the flushing liquid S has a higher flow resistance than the air previously present in the circulating pump 22. If the power requirement (or some other characteristic variable, such as power consumption, for example) exceeds a previously defined limit value, the controller finally recognizes that washing liquid S is flowing into the dishwasher 1. If the measuring device 38 still does not supply a signal, this is a sign that it is malfunctioning.

According to the invention, it is now proposed for this case that the inlet valve 18 is closed as a function of the results of the concentricity test. Thus, the inlet valve 18 is no longer closed, as is normally provided, after a certain amount of flushing liquid detected by means of the measuring device 38. Rather, the closing only takes place when it is recognized by means of the concentricity monitoring device 25 that the circulating pump 22 is in concentricity. This is the case when no air but only rinsing liquid S is sucked in, as explained in more detail above. Through this Finally, it is ensured that the dishwasher 1 can be safely filled with washing liquid S even in the event of a malfunction of the measuring device 38.

Furthermore, the dishwasher 1 has a conventional metering device 26 which enables the washing liquid S introduced into the washing chamber 7 to be mixed with detergents, rinse aid and / or cleaning aids and / or additives such as softeners, etc ... to improve the cleaning effect and / or the drying effect of a wash cycle.

Furthermore, the Figure 1 Dishwasher 1 shown has a drainage device 27 which is used to pump washing liquid S that is no longer required as waste water AW from the washing chamber 7 to the outside. The drainage device 27 comprises a drain pump 28, the inlet side of which is connected to the collecting pot 21. The output side of the drain pump 28, on the other hand, is connected to a connecting line 29, the downstream end of which is connected to a connection 30 of the dishwasher 1 that is fixed to the housing.

In the exemplary embodiment, the drain pump 28, like the circulation pump 22, has a brushless AC motor, also called a BLAC motor. However, other engine concepts would also be conceivable here.

A sewage hose 31, which is designed to be flexible, is attached to an outlet of the connection 30 which is fixed to the housing. At the downstream end of the sewage hose 31, a connection piece 32 is arranged, which is provided to connect the drainage device 27 to a sewage disposal device AR. The sewage disposal device AR can be a sewage pipe of a building-side water installation. The connection between the connection piece 32 and the sewer pipe can be designed as a screw connection, a bayonet connection, a plug connection or the like.

Figure 2 shows a block diagram of the domestic dishwasher 1 of Figure 1 , whereby in particular the control and communication concept is shown. In the exemplary embodiment, a signal line 33 is provided which connects the operating device 3 to the control / regulating device 2 in such a way that operating commands from an operator can be transmitted from the operating device 3 to the control / regulating device 2. Furthermore, a signal line 34 is provided which connects the control / regulating device 2 to the output device 4, so that information provided by the control / regulating device 2 can be transmitted to the output device 4 and output there to the operator.

Furthermore, a control line 35 is provided which connects the control / regulating device 2 to the switchable inlet valve 18 in such a way that the inlet valve 18 can be closed or opened by the control / regulating device 2. In this way, the filling of washing liquid S into the washing chamber 7 can be controlled by the control / regulating device 2. There is also a signal line 39 with which the measuring device 38 is connected to the control / regulating device 2.

The control / regulating device 2 is designed in such a way that information generated by the concentricity monitoring unit 25 when switching, in particular when controlling the closing and / or opening times of the inlet valve 18, possibly also when controlling and / or regulating the filling flow can be taken into account.

A supply line 36 connects the control / regulating device 2 to the circulating pump 22. As a result, the circulating pump 22 can also be switched by the control / regulating device 2. The control / regulating device 2 is designed to switch the circulating pump 22 on and off and, in particular, to control and / or regulate the speed of the circulating pump 22. Furthermore, a supply line 37 is provided which connects the control / regulating device 2 to the drain pump 28, so that the drain pump 28 can also be switched, in particular switched off and on, by the control / regulating device 2. The speed of the drain pump 28 can also be controllable and / or regulatable by the control / regulating device 2.

Figure 3 finally shows part of a schematic sequence of a washing program according to the invention.

After the start ST of the washing program, a functional test F of the filling system takes place after the inlet valve 18 has been opened. If the measuring device 38, such as an impeller meter, delivers measuring signals and thus detects an inflow of rinsing liquid S, so it can be assumed that the filling system works as required. In this case, the measured values of the measuring device 38 according to the standard program A are used in order to determine the amount of the washing liquid S flowing into the dishwasher 1. If a sufficient amount has flowed in, the inlet valve 18 is closed again. Finally, the washing program is run through until a previously defined end point E is reached.

If, on the other hand, the measuring device 38 does not display any signals during the functional test F, the circulating pump 22 is checked for concentricity with the help of the concentricity monitoring unit 25. If this test shows that washing liquid S flows into the dishwasher 1, although the measuring device 38 does not provide any corresponding signals, it works the control / regulating device 2 assumes that there is a malfunction of the measuring device 38. In this case, the dishwasher 1 is operated according to an alternative washing program B. This differs from the standard program A in that the amount of the inflowing rinsing liquid S is no longer determined on the basis of the measured values of the measuring device 38, but rather as a function of the results of the concentricity test. If the concentricity check shows that the circulating pump 22 is being operated in concentricity, then the inlet valve 18 is closed again, since it can be assumed that there is sufficient washing liquid S in the dishwasher 1. Of course, the inlet valve 18 does not have to be closed immediately after the true running has been detected. Rather, it is also conceivable to allow a predetermined period of time to elapse between the two events in order to be able to reliably exclude an insufficient amount of flushing liquid. Finally, in this case too, the washing program is run through according to the specifications of the control / regulating device 2 and likewise ends in an end point E.

In the context of a last exemplary embodiment, it is provided that in the event of the detection of a faulty measuring device 38 (eg a flow meter designed as an impeller meter), an emergency program is activated with the aid of a BLAC circulating pump 22. In this case, certain program sequences are skipped or replaced by modified sequences. The dishwasher 1 is finally filled with a load-dependent filling algorithm.

The advantages of the invention are that the performance of the cleaning performance or drying performance is kept at a similar level as is the case with a functioning measuring device 38. This reduces customer service calls.

Otherwise, the invention is not restricted to the exemplary embodiments shown. Rather, all combinations of the individual features described, as shown or described in the claims, the description and the figures and as far as a corresponding combination appears technically possible or sensible, are the subject matter of the invention.

Generally speaking, a malfunction or failure of the measuring device when the inlet valve is open is recognized by the fact that, as part of the concentricity monitoring, it is examined whether the circulating pump is subjected to a specific load or a load profile characteristic of a water inlet. If this is the case, this indicates for the control / regulating device that the water is running into the washing container. The control / regulating device then closes the inlet valve as a function of the load detection. In this way, the dishwasher can be filled with a specific, desired amount of water for the respective water-carrying partial wash cycle of a selected dishwasher program, even without a functioning or malfunctioning measuring device.

List of reference symbols

1

dishwasher

2

Control / regulating device

3

Control device

4th

Output device

5

Rinsing container

6th

door

7th

Rinsing chamber

8th

casing

9

upper basket

10

lower basket

11

Pull-out rail

12th

Pull-out rail

13th

Intake

14th

Connector

15th

Connection hose

16

connection piece fixed to the housing

17th

supply line

18th

Inlet valve

19th

Liquid inlet

20th

ground

21

Collecting pot

22nd

Circulation pump

23

upper spray arm

24

lower spray arm

25th

Runout monitoring unit

26th

Dosing device

27

Drainage facility

28

Drain pump

29

Connecting line

30th

connection fixed to the housing

31

Sewer hose

32

Connector

33

Signal line

34

Signal line

35

Control line

36

supply line

37

supply line

38

Measuring device

39

Signal line

WH

Water supply facility

ZW

Inlet water

S.

Rinsing liquid

AR

Sewage disposal facility

AW

sewage

ST

Start of the washing program

F.

Functional test

A.

Standard program

E.

End point

B.

alternative washing program

Claims (12)

1. Dishwasher, in particular household dishwasher, with a washing chamber (7) for receiving items to be washed, with an inlet (13), by way of which washing liquid (S) can flow into the dishwasher (1), with an inlet valve (18), by way of which the quantity of inflowing washing liquid (S) can be regulated, with a measuring device (38), with the aid of which the quantity of washing liquid (S) flowing into the dishwasher (1) and/or the position of the inlet valve (18) can be determined, with a recirculation pump (22) for recirculating the inflowing washing liquid (S) within the dishwasher (1), and with a control/regulation device (2), wherein the control/regulation device (2) is embodied to adjust the quantity of washing liquid (S) flowing into the dishwasher (1) by activating the inlet valve (18), wherein the control/regulating device (2) comprises a rotation monitoring unit (25), with the aid of which a rotation monitoring of the recirculation pump (22) can be carried out, and wherein the control/regulation device (2) is embodied to monitor the functionality of the measuring device (38) at least when the inlet valve (18) is opened, and to close the inlet valve (18) in the event of a malfunction of the measuring device (38) as a function of the result of the rotation monitoring, characterised in that the control/regulation device (2) is embodied to close the inlet valve (18) as soon as the rotation monitoring indicates that the recirculation pump (22) is rotating and/or that the control/regulation device (2) is embodied to close the inlet valve (18) after a defined period of time has elapsed from the point in time at which the rotation monitoring indicates that the recirculation pump (22) is rotating, wherein during rotation the power consumption or the power uptake of the recirculation pump stagnates.
2. Dishwasher according to the preceding claim, characterised in that the rotation monitoring unit (25) is embodied to carry out the rotation monitoring based on the power consumption or the power uptake of the recirculation pump (22).
3. Dishwasher according to one or more of the preceding claims, characterised in that the recirculation pump (22) comprises a brushless direct current motor or a brushless alternating current motor.
4. Dishwasher according to one or more of the preceding claims, characterised in that the control/regulation device (2) is embodied to monitor the functionality of the measuring device (38) on the basis of the power consumption or the power uptake of the measuring device (38).
5. Dishwasher according to one or more of the preceding claims, characterised in that the control/regulation device (2) is embodied to monitor the functionality of the measuring device (38) on the basis of the comparison of the measured values of the measuring device (38) with the result of the rotation monitoring.
6. Dishwasher according to one or more of the preceding claims, characterised in that the control/regulation device (2) is embodied to monitor the functionality of the measuring device (38) by comparing the measured values of the measuring device (38) with the required position of the inlet valve (18).
7. Dishwasher according to one or more of the preceding claims, characterised in that the control/regulation device (2) is embodied to close the inlet valve (18), in the event of a malfunction of the measuring device (38) as a function of the time, after it was closed as a function of the result of the rotation monitoring and was reopened in order additionally to allow washing liquid (S) to flow in.
8. Dishwasher according to one or more of the preceding claims, characterised in that the control/regulation device (2) is embodied to operate the dishwasher (1) according to a wash programme which can be selected in particular by an operator and which comprises a number of wash cycles, for instance in the form of a prewash cycle, a cleaning cycle or an intermediate wash cycle, a rinse aid cycle and/or a drying cycle, and wherein the control/regulation device (2) is embodied, in the event of a malfunction of the measuring device, to skip or modify at least one of the wash cycles or to replace the same with an alternative wash cycle.
9. Dishwasher according to one or more of the preceding claims, characterised in that the control/regulation device (2) is embodied to operate the dishwasher (1) according to a wash programme which can be selected in particular by an operator, and to monitor the functionality of the measuring device (38) after each start of the wash programme, wherein the inlet valve (18) is closed exclusively in the event of a malfunction of the measuring device (38) as a function of the result of the rotation monitoring and on the other hand as a function of the measured values of the measuring device (38).
10. Dishwasher according to one or more of the preceding claims, characterised in that the rotation monitoring unit (25) comprises a filter arrangement with a bandpass behaviour for generating a filtered output signal and an evaluation arrangement downstream of the filter arrangement for evaluating the filtered power signal.
11. Method for operating a dishwasher (1), in particular a household dishwasher, preferably according to one or more of the preceding claims, with a washing chamber (7) for receiving items to be washed, with an inlet (13), by way of which washing liquid (S) can flow into the dishwasher (1), with an inlet valve (18), by way of which the quantity of inflowing washing liquid (S) is regulated, with a measuring device (38), with the aid of which the quantity of washing liquid (S) flowing into the dishwasher (1) and/or the position of the inlet valve (18) can be determined, with a recirculation pump (22) for recirculating the washing liquid (S) within the dishwasher (1), and with a control/regulation device (2), wherein the control/regulation device (2) is embodied to adjust the quantity of washing liquid (S) flowing into the dishwasher (1) by activating the inlet valve (18), wherein the control/regulation device (2) comprises a rotation monitoring unit (25), with the aid of which a rotation monitoring of the recirculation pump (22) can be carried out, and wherein the functionality of the measuring device (38), at least when the inlet valve (18) is opened, is monitored with the aid of the control/regulation device (2) and the inlet valve (18) is closed in the event of a malfunction of the measuring device (38) as a function of the result of the rotation monitoring, characterised in that the control/regulation device (2) closes the inlet valve (18) as soon as the rotation monitoring indicates that the recirculation pump (22) is rotating, wherein during rotation the power consumption or the power uptake of the recirculation pump stagnates.
12. Method according to claim 11, characterised in that the functionality of the measuring device (38) is monitored after each start of the wash programme and that the inlet valve (18) is closed exclusively in the event of a malfunction of the measuring device (38) as a function of the result of the rotation monitoring and on the other hand as a function of the measured values of the measuring device (38).

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