Dishwasher, method for operating a dishwasher, and computer program product

Abstract

A dishwasher includes a dishwasher interior for washing items to be washed with washing liquor. Arranged at a lower end of the dishwasher interior is a pump sump for collecting the washing liquor, and a sensor is arranged in the pump sump for outputting a sensor signal as a function of a presence of washing liquor at the sensor. A control apparatus configured to carry out a washing program selected from a number of washing programs is designed to determine a malfunction of a component of a hydraulic assembly as a function of the sensor signal and of a current operating state of the dishwasher.

Claims

1. A dishwasher, comprising: a dishwasher interior for washing items to be washed with washing liquor; a pump sump arranged at a lower end of the dishwasher interior for collecting soiled washing liquor; an optical sensor arranged in the pump sump for outputting a sensor signal as a function of a presence of the soiled washing liquor at the optical sensor arranged in the pump sump; a drain pump arranged in the pump sump for pumping the soiled washing liquor out of the pump sump into an outlet hose; a drain check valve arranged between the drain pump and the outlet hose to retain the soiled washing liquor pumped into the outlet hose; a hydraulic assembly; and a control apparatus configured to perform operations comprising: executing a washing program selected from a number of washing programs; activating the drain pump to pump the soiled washing liquor out of the pump sump into the outlet hose while an inlet valve is closed; subsequent to activating the drain pump to pump the soiled washing liquor out of the pump sump into the outlet hose while the inlet valve is closed, receiving, from the optical sensor arranged in the pump sump, the sensor signal as the function of the presence of the soiled washing liquor at the optical sensor arranged in the pump sump; and detecting a malfunction of the drain check valve based on the receiving, from the optical sensor arranged in the pump sump, the sensor signal as the function of the presence of the soiled washing liquor at the optical sensor arranged in the pump sump, wherein the malfunction of the drain check valve comprises a failure of the drain check valve to retain the soiled washing liquor pumped into the outlet hose.

2. The dishwasher of claim 1, constructed in the form of a household dishwasher.

3. The dishwasher of claim 1, wherein the inlet valve is for connecting the dishwasher to an external water supply pipe for supplying fresh water, and wherein the control apparatus is further configured to perform operations comprising determining a malfunction of the inlet valve.

4. The dishwasher of claim 1, further comprising a flow-through sensor arranged between the inlet valve and the dishwasher interior to detect a fresh water volume supplied via the inlet valve, and wherein the control apparatus is further configured to perform operations comprising detecting a malfunction of the optical sensor, the flow-through sensor and/or the inlet valve as a function of the fresh water volume and of a sensor signal detected by the flow-through sensor.

5. The dishwasher of claim 1, wherein the dishwasher further comprises: a liquor reservoir for temporary storage of washing liquor; a valve arranged between the liquor reservoir and the dishwasher interior, said valve retaining in a closed state the temporarily stored washing liquor in the liquor reservoir and releasing in an open state the temporarily stored washing liquor into the dishwasher interior; and wherein the control apparatus is further configured to perform operations comprising detecting a leakiness of the valve arranged between the liquor reservoir and the dishwasher interior.

6. The dishwasher of claim 5, wherein the control apparatus is configured to perform the operation of detecting the leakiness of the valve arranged between the liquor reservoir and the dishwasher interior after the liquor reservoir has been filled and before the temporarily stored washing liquor is released and/or fresh water is supplied into the dishwasher interior.

7. The dishwasher of claim 1, wherein the dishwasher further comprises: a heat exchanger for receiving fresh water to support a drying process and for heating the received fresh water; and a valve arranged between the heat exchanger and the dishwasher interior, said valve retaining in a closed state the fresh water in the heat exchanger and releasing in an open state the fresh water into the dishwasher interior, and wherein the control apparatus is further configured to perform operations comprising detecting leakiness of the valve arranged between the heat exchanger and the dishwasher interior.

8. The dishwasher of claim 7, wherein the control apparatus is configured to perform the operation of detecting the leakiness of the valve arranged between the heat exchanger and the dishwasher interior after the heat exchanger has been filled and before the received fresh water is drained out and/or fresh water is supplied into the dishwasher interior.

9. The dishwasher of claim 1, wherein the optical sensor is arranged in the pump sump in such a way that the optical sensor is surrounded by washing liquor with a washing liquor volume of 0.4 liters.

10. The dishwasher of claim 1, wherein the optical sensor is arranged in the pump sump in such a way that the optical sensor is surrounded by washing liquor with a washing liquor volume of 0.3 liters.

11. The dishwasher of claim 1, wherein the optical sensor is arranged in the pump sump in such a way that the optical sensor is surrounded by washing liquor with a washing liquor volume below 0.3 liters in the pump sump.

12. The dishwasher of claim 1, further comprising a user interface designed to output the malfunction of the drain check valve.

13. The dishwasher of claim 12, further comprising a memory unit designed to store the malfunction of the drain check valve, said user interface outputting the malfunction of the drain check valve stored in the memory unit.

14. A method for operating a dishwasher, said method comprising: activating a drain pump to pump soiled washing liquor out of a pump sump into an outlet hose while an inlet valve is closed, wherein the pump sump is arranged at a lower end of a dishwasher interior for collecting washing liquor used for washing items to be washed in the dishwasher interior, wherein the drain pump is arranged in the pump sump, and wherein a drain check valve is arranged between the drain pump and the outlet hose to retain the soiled washing liquor pumped into the outlet hose; subsequent to activating the drain pump to pump the soiled washing liquor out of the pump sump into the outlet hose while the inlet valve is closed, receiving, from an optical sensor arranged in the pump sump, a sensor signal as a function of a presence of the soiled washing liquor at the optical sensor arranged in the pump sump; determining a malfunction of the drain check valve based on the receiving, from the optical sensor arranged in the pump sump, the sensor signal as the function of the presence of the soiled washing liquor at the optical sensor arranged in the pump sump, wherein the malfunction of the drain check valve comprises a failure of the drain check valve to retain the soiled washing liquor pumped into the outlet hose.

15. The method of claim 14, wherein the method is for operating a household dishwasher.

16. A computer program product for operating a dishwasher, comprising a computer program embodied in a non-transitory computer readable medium, wherein the computer program, when loaded into a computer and executed by the computer, causes the computer to execute the steps of: activating a drain pump to pump soiled washing liquor out of a pump sump into an outlet hose while an inlet valve is closed, wherein the pump sump is arranged at a lower end of a dishwasher interior for collecting washing liquor used for washing items to be washed in the dishwasher interior, wherein the drain pump is arranged in the pump sump, and wherein a drain check valve is arranged between the drain pump and the outlet hose to retain the soiled washing liquor pumped into the outlet hose; subsequent to activating the drain pump to pump the soiled washing liquor out of the pump sump into the outlet hose while the inlet valve is closed, receiving, from an optical sensor arranged in the pump sump, a sensor signal as a function of a presence of the soiled washing liquor at the optical sensor arranged in the pump sump; and determining a malfunction of the drain check valve based on the receiving, from the optical sensor arranged in the pump sump, the sensor signal as the function of the presence of the soiled washing liquor at the optical sensor arranged in the pump sump, wherein the malfunction of the drain check valve comprises a failure of the drain check valve to retain the soiled washing liquor pumped into the outlet hose.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantageous embodiments and aspects of the invention form the subject matter of the subclaims and of the exemplary embodiments of the invention that are described below. The invention is described below in greater detail on the basis of preferred embodiments with reference to the attached figures.

(2) FIG. 1 shows a schematic perspective view of an exemplary embodiment of a dishwasher;

(3) FIG. 2 shows a schematic view of a second embodiment of a dishwasher;

(4) FIG. 3 shows a schematic view of a third embodiment of a dishwasher;

(5) FIG. 4 shows a schematic view of a fourth embodiment of a dishwasher;

(6) FIG. 5 shows an exemplary diagram of a sequence of sensor signals;

(7) FIG. 6 shows a further exemplary diagram of a sequence of sensor signals;

(8) FIG. 7 shows a further exemplary diagram of a sequence of sensor signals; and

(9) FIG. 8 shows a schematic block diagram of an exemplary embodiment of a method for operating a dishwasher.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE PRESENT INVENTION

(10) In the figures, elements that are identical or have the same function are provided with the same reference characters unless otherwise stated.

(11) FIG. 1 shows a schematic perspective view of an embodiment of a dishwasher 1, which is embodied here as a household dishwasher. The household dishwasher 1 has a dishwasher cavity 2, which can be closed by a door 3, in particular in a watertight manner. A sealing facility can be provided for this purpose between the door 3 and the dishwasher cavity 2. The dishwasher cavity 2 is preferably cuboid in shape. The dishwasher cavity 2 may be arranged in a housing of the household dishwasher 1. The dishwasher cavity 2 and the door 3 may form a dishwasher interior 4 for washing items to be washed.

(12) The door 3 is shown in its opened position in FIG. 1. The door 3 can be closed or opened by pivoting about a pivot axis 5 provided on a lower end of the door 3. A loading opening 6 of the dishwasher cavity 2 can be closed or opened with the aid of the door 3. The dishwasher cavity 2 has a bottom 7, a ceiling 8 arranged opposite the bottom 7, a rear wall 9 arranged opposite the closed door 3 and two side walls 10, 11 arranged opposite one another. The bottom 7, the ceiling 8, the rear wall 9 and the side walls 10, 11 may be manufactured from a stainless steel sheet for example. Alternatively, the bottom 7 may be manufactured from a plastic material.

(13) Furthermore, the household dishwasher 1 has at least one receptacle for items to be washed 12 to 14. A number of, for instance three, receptacles for items to be washed 12 to 14 can preferably be provided, wherein the receptacle for items to be washed 12 can be a lower receptacle for items to be washed or a bottom basket, the receptacle for items to be washed 13 can be an upper receptacle for items to be washed or an upper basket and the receptacle for items to be washed 14 can be a cutlery drawer. As additionally shown in FIG. 1, the receptacles for items to be washed 12 to 14 are arranged above one another in the dishwasher cavity 2. Each receptacle for items to be washed 12 to 14 is optionally able to be shifted into or out from the dishwasher cavity 2. In particular, each receptacle for items to be washed 12 to 14 is able be inserted or pushed into the dishwasher cavity 2 in an insertion direction E and extracted or pulled out from the dishwasher cavity 2 in an extraction direction A opposite to the insertion direction E.

(14) A control apparatus 20 is arranged on the door 3 of the dishwasher 1, which control apparatus is here implemented as hardware, for example, and is designed to carry out one of a number of washing programs. Furthermore, a pump sump 50 is arranged at the lower end of the dishwasher interior 4, in which pump sump a sensor 40 and a hydraulic assembly 30 are arranged. The sensor 40 is designed to output a sensor signal 102 (see FIGS. 5-7), which indicates which fluid is currently surrounding the sensor 40, such as for example air or washing liquor. In embodiments, the sensor 40 can also be designed to determine a degree of soiling of the washing liquor. In this example, the hydraulic assembly 30 comprises for example a drain check valve 36 (see FIG. 3), which is arranged between a drain pump and an outlet hose 70.

(15) The control apparatus 20 is also designed to detect or determine a current operating state of the household dishwasher 1. The current operating state of the household dishwasher 1 depends in particular on a currently running program sub-step of the washing program being carried out and the action last performed or started. Accordingly, the current operating state comprises all current operating parameters of the household dishwasher 1, such as for example a current volume of washing liquor, a current recirculating pump speed, a current washing liquor temperature and the like.

(16) The control apparatus 20 is designed in particular to determine a malfunction of the hydraulic assembly 30 as a function of the current operating state and of the sensor signal 102. Specific exemplary embodiments hereto are explained with reference to the figures described below.

(17) FIG. 2 shows a schematic view of a second embodiment of a dishwasher 1, which is embodied as a household dishwasher and in particular has all components as described for the household dishwasher from FIG. 1, even if these are not shown in FIG. 2. The household dishwasher 1 is shown in FIG. 2 in a schematic side view. The pump sump 50 is arranged at the lower end of the dishwasher cavity 4, on the side of which pump sump the sensor 40 is arranged. The pump sump 50 can furthermore have different filter assemblies, which are not shown in FIG. 2 for the sake of clarity. The hydraulic assembly 30, which here comprises a water connection with an inlet valve 32 and a flow-through sensor 34, is shown to the side of the dishwasher interior 4. The flow-through sensor 34 is designed to measure the supplied volume of fresh water. The inlet valve 32 is connected to an external water supply pipe 60. The arrow in the water supply pipe 60 indicates the flow direction of the water when the inlet valve 32 is open.

(18) With the household dishwasher 1, it is advantageously possible to determine whether the hydraulic assembly 30, in particular the inlet valve 32 or the flow-through sensor 34 or also the sensor 40 has a malfunction or a defect.

(19) According to a first scenario, all components operate as intended. Once the inlet valve 32 has opened, the flow-through sensor 34 measures the supplied volume of fresh water, which is indicated by a rising sensor signal 104 (see FIG. 5). The flow-through sensor 34 is embodied for example as a flowmeter, which emits a pulse for each 5 ml of fluid that passes through the flowmeter. After a defined time interval t (see FIG. 5, 6), if the required volume of fresh water has been supplied, the pump sump 50 will be filled with the supplied fresh water to such an extent that the sensor 40 is now surrounded by the fresh water. The sensor signal 102 changes accordingly, wherefrom it can be concluded that the sensor 40 is surrounded by water. FIG. 5 shows an exemplary temporal sequence of the sensor signal 102 of the sensor 40 and of the sensor signal 104 of the flow-through sensor 34, as they can occur in this scenario.

(20) According to a second scenario, the inlet valve 32 has a malfunction or the household dishwasher 1 is not properly connected to the external water supply pipe 60, so that no or very little fresh water can be supplied. Once the control apparatus 20 has actuated the inlet valve 32 to open, the flow-through sensor 34 will not measure any water flow. In addition, the sensor signal 102 will not have changed after the defined time interval t. It is therefore possible to conclude that no fresh water is being supplied and there is therefore a problem with the inlet valve 32 or the connection to the water supply pipe 60.

(21) According to a third scenario, the flow-through sensor 34 has a malfunction. For example, the flow-through sensor 34 outputs no measurement signal at all or it outputs an incorrect measurement signal. This can be caused, for example, by a defect or blockage of the flow-through sensor 34. Once the inlet valve 32 has opened, for example no measurement signal of the flow-through sensor 34 is detected, which indicates that no fresh water is being supplied. If however the sensor signal 102 changes its level after the defined time interval t, it is possible to conclude from this situation that the flow-through sensor 34 has a malfunction. FIG. 6 shows an exemplary temporal sequence of the sensor signal 102 of the sensor 40 and of the sensor signal 104 of the flow-through sensor 34, as they can occur in this scenario.

(22) According to a fourth scenario, the sensor 40 in the pump sump 50 has a malfunction. Once the inlet valve 32 has opened, the flow-through sensor 34 will output the expected measurement signal, which indicates that fresh water is being supplied properly. However, the sensor signal 102 will not change even once the required volume of fresh water has been supplied, as the sensor 40 is defective. The defective sensor 40 can therefore be determined unambiguously.

(23) FIG. 3 shows a schematic view of a third embodiment of a dishwasher 1, which is embodied as a household dishwasher and in particular has all components as described for the household dishwasher from FIGS. 1 and 2, even if these are not shown in FIG. 3. The household dishwasher 1 is shown in FIG. 3 in a schematic side view. The pump sump 50 is arranged at the lower end of the dishwasher interior 4, on the side of which pump sump the sensor 40 is arranged. A drain pump (without a reference character) is arranged at the lower end of the pump sump 50, which drain pump is designed to pump the washing liquor out of the pump sump 50 into the outlet hose 70, which is connected to the pump sump 50. A drain check valve 36 is disposed between the drain pump and the outlet hose 70, which drain check valve is designed to allow the pumped-out washing liquor to flow into the outlet hose 70 but not to allow the washing liquor present in the outlet hose 70 to flow back into the pump sump 50 and thus into the dishwasher interior 4. The outlet hose 70 is in turn connected to a wastewater pipe, which is disposed for example at a height of approximately 80 cm above the connection to the pump sump 50 (not shown).

(24) If, once the soiled washing liquor has been pumped away, for example after cleaning, the drain check valve 36 has a malfunction because for example food residue has become trapped therein and is preventing the drain check valve 36 from closing tightly, some of the washing liquor will flow from the outlet hose 70 back into the pump sump 50. After a defined time interval t (see FIG. 7), the pump sump 50 will have filled up to such an extent that the sensor 40 is once again surrounded by the soiled washing liquor. This can be determined on the basis of the sensor signal 102 output by the sensor 40. FIG. 7 shows an exemplary temporal sequence of the sensor signal 102 of the sensor 40, as it could occur in this scenario. In this way, therefore, a malfunction of the drain check valve 36 can be concluded and detrimental effects, such as a poor washing result or the formation of unpleasant odors, can be avoided.

(25) FIG. 4 shows a schematic view of a fourth embodiment of a dishwasher 1, which is embodied as a household dishwasher and in particular has all components as described for the household dishwasher from FIG. 1, even if these are not shown in FIG. 4. The household dishwasher 1 is shown in FIG. 4 in a schematic side view. The pump sump 50 is arranged at the lower end of the dishwasher interior 4, on the side of which pump sump the sensor 40 is arranged. A liquor reservoir 80 is arranged on the side of the household dishwasher 1, which liquor reservoir is connected to the dishwasher interior 4 by way of two connecting pipes (without a reference character). A valve 38, with which the content of the liquor reservoir 80 can be released into the dishwasher interior 4, is disposed on the lower supply pipe. Not shown is a recirculating pump, which serves to fill the liquor reservoir 80 with washing liquor by pumping the washing liquor into the liquor reservoir 80.

(26) The liquor reservoir 80 is used for the temporary storage of washing liquor so that this can be used at a later time, in particular in a subsequent washing cycle. The valve 38 retains the washing liquor in the liquor reservoir 80. If however the valve 80 is leaky, then the content of the liquor reservoir 80 will run out even though the valve 38 is deemed closed. Accordingly, the content of the liquor reservoir 80 is no longer available at the later time when the temporarily stored washing liquor is to be used. If the washing liquor which has run out has in the meantime been pumped away, for example at the start of the next washing cycle, insufficient washing liquor is therefore present in the dishwasher interior 4 to ensure a good washing result. By the sensor signal 102 (see FIGS. 5-7) being evaluated at regular intervals while the washing liquor is stored in the liquor reservoir 80, it is possible to determine whether the valve 38 is leaky if the pump sump 50 is filled with washing liquor despite the valve 38 being closed.

(27) In a further exemplary embodiment (not shown), a heat exchanger can be provided instead of the liquor reservoir 80, which heat exchanger is connected to the household dishwasher 1 in the same way as the liquor reservoir 80 but is in thermal contact with the dishwasher interior 4, so that an effect which supports drying can be achieved by introducing cold fresh water into the heat exchanger. In accordance with the aforementioned example, a further valve, which is designed to retain the fresh water in the heat exchanger, can be checked for a malfunction, in particular a leak.

(28) FIGS. 5 and 6 in each case show an exemplary diagram of a sequence of sensor signals 102, 104 of a flow-through sensor 34 (see FIG. 2) and of a sensor 40 of a household dishwasher 1, for example the household dishwasher 1 from FIG. 2. The sensor signals 102, 104 change along a time axis t as a function of the current operating state of the household dishwasher 1. At a time instant t0, the inlet valve 32 of the household dishwasher 1 is opened, so that fresh water is supplied. In FIG. 5, the sensor signal 104 of the flow-through sensor 34 thereupon rises linearly. Once a certain volume of fresh water, for example 0.3 liters, has been supplied within the time interval t, the sensor signal 102 of the sensor 40 changes at a time instant t1. This indicates that the sensor 40 is now surrounded by water. The flow-through sensor 34 and the sensor 40 thus have no malfunction. In FIG. 6, the sensor signal 104 of the flow-through sensor 34 remains constant, even though the inlet valve 32 has been opened at the time instant t0. After expiration of the time interval t, in this example the sensor signal 102 of the sensor 40 changes at the time instant t2, wherefrom it can be concluded that fresh water has actually been supplied. Accordingly, there is a malfunction in the flow-through sensor 34.

(29) FIG. 7 shows a further exemplary diagram of a sequence of a sensor signal 102 of a sensor 40 (see FIG. 3) of a household dishwasher 1, for example the household dishwasher 1 from FIG. 3. The sensor signal 102 changes along the time axis t as follows: The sensor signal 102 initially has a high level, which indicates that the sensor 40 is surrounded by washing liquor. At a time instant t0, for example the drain pump is activated in order to pump the washing liquor away. At a time instant t1, the washing liquor has for example been pumped away to such an extent that the sensor 40 is now surrounded by air, on account of which the level of the sensor signal 102 falls. At a time instant t2, the level of the sensor signal 102 rises again. Provided that no washing liquor has been supplied deliberately in the time interval t between t1 and t2, for example fresh water from the external water supply pipe 60 (see FIG. 2), it is possible to conclude from this rise that the drain check valve 36, which retains the pumped-off washing liquor in the outlet hose 70, is leaky and thus has a malfunction.

(30) FIG. 8 shows a schematic block diagram of an exemplary embodiment of a method for operating a dishwasher 1, for example one of the household dishwashers previously described with reference to FIGS. 1-4. In a first method step S1, a current operating state of the household dishwasher 1 is determined. This takes place in particular by way of the control apparatus 20 of the household dishwasher 1. In a second method step S2, a sensor signal 102 of a sensor 40 arranged in a pump sump 50 is detected and output to the control apparatus 20. In a third method step S3, a malfunction of a component 32-38 of a hydraulic assembly 30 of the household dishwasher 1 is determined as a function of the current operating state and of the sensor signal 102.

(31) Although the present invention has been described with reference to exemplary embodiments, it can be modified in numerous different ways. In particular, all exemplary embodiments described can be combined with one another.