Dishwasher and method for operating a dishwasher

Abstract

A dishwasher includes a pump device operated by a pump current for supply of washing liquor to a first spray device via a first hydraulic arrangement for providing a first washing zone and to a second spray device via a second hydraulic arrangement for providing a second washing zone. A third spray device is connected to one of the first and second hydraulic arrangements for providing an intensive washing zone. In a first switching state, the third spray device is isolated from the one hydraulic arrangement, and in a second switching state the third spray device is connected to the one hydraulic arrangement. A control device determines a current switching state of the third spray device as a function of a difference between the pump current when washing liquor is supplied to the first hydraulic arrangement and when washing liquor is supplied to the second hydraulic arrangement.

Claims

1. A household dishwasher, comprising: a first hydraulic arrangement; a second hydraulic arrangement; a pump device operated by a pump current for supply of a washing liquor to the first hydraulic arrangement and to the second hydraulic arrangement; a first spray device connected to the first hydraulic arrangement for providing a first washing zone; a second spray device connected to the second hydraulic arrangement for providing a second washing zone; a third spray device connected to one of the first and second hydraulic arrangements for providing an intensive washing zone, said third spray device having a first switching state in which the third spray device is isolated from the one of the first and second hydraulic arrangements, and a second switching state in which the third spray device is connected to the one of the first and second hydraulic arrangements; and a control device configured to determine a current switching state of the third spray device as a function of a difference between the pump current when washing liquor is supplied to the first hydraulic arrangement and when washing liquor is supplied to the second hydraulic arrangement, the control device configured to determine the current switching state of the third spray device by detecting a first pump current when the first hydraulic arrangement is supplied with washing liquor, detecting a second pump current when the second hydraulic arrangement is supplied with washing liquor, and determining a delta value as a difference between the first pump current and the second pump current, the control device further configured to compare the delta value with a predefined threshold value, with the delta value being greater than the threshold value in the first switching state of the third spray device and smaller than the threshold value in the second switching state of the third spray device.

2. The dishwasher of claim 1, wherein the control device is configured to detect a first temporal mean value of the first pump current when the first hydraulic arrangement is supplied during a first predetermined time interval, to detect a second temporal mean value of the second pump current when the second hydraulic arrangement is supplied during a second predetermined time interval, and to determine the delta value as a difference between the first temporal mean value and the second temporal mean value.

3. The dishwasher of claim 1, wherein the control device is configured to perform a dishwashing program selected from a number of dishwashing programs, each of the dishwashing programs being determined by a plurality of dishwashing program parameters, said control device adjusting at least one dishwashing program parameter from the plurality for the dishwashing program currently being performed as a function of the current switching state of the third spray device and as a function of a dishwashing program currently being performed.

4. The dishwasher of claim 3, wherein the control device determines the current switching state of the third spray device at a start of each performance of the dishwashing program.

5. The dishwasher of claim 1, wherein the pump device operates at a pump speed which is constant during determination of the current switching state of the third spray device.

6. The dishwasher of claim 1, wherein the control device monitors a smooth running of the pump device when determining the current switching state of the third spray device.

7. The dishwasher of claim 1, further comprising a manually operated switching device to switch the third spray device from the first switching state to the second switching state, and vice versa.

8. The dishwasher of claim 7, wherein the switching device comprises a valve.

9. The dishwasher of claim 8, wherein the valve is a switching valve.

10. The dishwasher of claim 1, wherein each of the first and second spray devices comprises a spray arm.

11. The dishwasher of claim 1, wherein the third spray device comprises a spray arm or a spray nozzle or both.

12. The dishwasher of claim 1, further comprising an output unit configured to output the current switching state of the third spray device to a user.

13. The dishwasher of claim 12, wherein the output unit transmits the current switching state to a mobile device of the user.

14. A method for operating a household dishwasher, said method comprising: operating a pump device by a pump current for supply of washing liquor to a first spray device via a first hydraulic arrangement for providing a first washing zone and for supply of washing liquor to a second spray device via a second hydraulic arrangement for providing a second washing zone; connecting a third spray device to one of the first and second hydraulic arrangements for providing an intensive washing zone, allowing the third spray device to be switched between a first switching state in which the third spray device is isolated from the one of the first and second hydraulic arrangements, and a second switching state in which the third spray device is connected to the one of the first and second hydraulic arrangements; and determining with a control device a current switching state of the third spray device as a function of a difference between the pump current when washing liquor is supplied to the first hydraulic arrangement and when washing liquor is supplied to the second hydraulic arrangement by detecting a first pump current when the first hydraulic arrangement is supplied with washing liquor, detecting a second pump current when the second hydraulic arrangement is supplied with washing liquor, determining a delta value as a difference between the first pump current and the second pump current, and comparing the delta value with a predefined threshold value, with the delta value being greater than the threshold value in the first switching state of the third spray device and smaller than the threshold value in the second switching state of the third spray device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantageous configurations and aspects of the invention are set out in the subclaims and the exemplary embodiments of the invention described in the following. The invention is also described in more detail based on preferred embodiments with reference to the accompanying 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 further exemplary embodiment of a dishwasher;

(4) FIG. 3 shows an exemplary diagram of a profile of a pump current; and

(5) FIG. 4 shows a block diagram of an exemplary method for operating a dishwasher.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE PRESENT INVENTION

(6) Identical elements or those of identical function are shown with the same reference characters in the figures, unless otherwise specified.

(7) FIG. 1 shows a schematic perspective view of an embodiment of a dishwasher 1. The dishwasher 1 is configured as a household dishwasher 1 here. The household dishwasher 1 comprises a washing container 2, which can be closed, in particular in a water-tight manner, by a door 3. To this end a sealing facility (not shown) can be provided between the door 3 and the washing container 2. The washing container 2 is preferably box-shaped. The washing container 2 can be arranged in a housing of the household dishwasher 1. The washing container 2 and door 3 can form a washing chamber 4 for washing items to be washed.

(8) 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 at a lower end of the door 3. A loading opening 6 of the washing container 2 can be closed or opened with the aid of the door 3. The washing container 2 has a base 7, a top 8 arranged opposite the base 7, a rear wall 9 arranged opposite the closed door 3 and two opposing side walls 10, 11. The base 7, top 8, rear wall 9 and side walls 10, 11 can be made of stainless steel sheet for example. Alternatively the base 7 for example can be made of a plastic material.

(9) The household dishwasher 1 also has at least one receptacle 12, 13, 14 for items to be washed. A number of receptacles 12, 13, 14 for items to be washed, for example three, can preferably be provided, it being possible for the receptacle 12 for items to be washed to be a lower receptacle for items to be washed or a lower rack, the receptacle 13 for items to be washed to be an upper receptacle for items to be washed or an upper rack and the receptacle 14 for items to be washed to be a flatware drawer. As also shown in FIG. 1, the receptacles 12, 13, 14 for items to be washed are arranged one above the other in the washing container 2. Each receptacle 12 to 14 for items to be washed can be moved into or out of the washing container 2 as required. In particular each receptacle 12, 13, 14 for items to be washed can be pushed into the washing container 2 in an insertion direction E and pulled out of the washing container 2 in a pull-out direction A counter to the insertion direction E.

(10) The household dishwasher 1 also has a first spray device 112 assigned to a first hydraulic arrangement 110 and configured as a spray arm, a second spray device 122 assigned to a second hydraulic arrangement 120 and also configured as a spray arm and a third spray device 132 assigned to the second hydraulic arrangement. The first spray arm 112 is arranged on the base 7 of the washing container 2, the second spray arm 122 is arranged on the top 8 of the washing container 2 and the third spray device 132, which is configured as a number of spray nozzles, is arranged on the side wall 9 of the washing container 2. The first hydraulic arrangement 110 and the second hydraulic arrangement 120 can be supplied with washing liquor by means of a pump device 140 during operation of the household dishwasher 1. A control device 150 arranged on the door 3 of the household dishwasher 1 is also shown.

(11) The control device 150 is designed in particular to detect a pump current 142 (see FIG. 3) for operating the pump device 140. Because the control device 150 detects and compares the pump current 142 when the first hydraulic arrangement 110 is supplied with washing liquor and when the second hydraulic arrangement 120 is supplied with washing liquor, the control device 150 can determine the current switching state of the third spray device 132.

(12) FIG. 2 shows a schematic view of a further exemplary embodiment of a dishwasher 1, which is also configured as a household dishwasher. The household dishwasher 1 for example has the same features as the exemplary embodiment illustrated in FIG. 1 but with many of the features not shown for greater clarity. The pump device 140 is now arranged below the base 7 of the washing container 2, the base 7 having a drain for the washing liquor, which is designed to supply the washing liquor to the pump device 140. The third spray device 132 here is configured as a third spray arm and assigned to the second hydraulic arrangement 120. A switching device 160, configured here as a manually switchable valve, is also arranged at the connection between the third spray arm 132 and the second hydraulic arrangement 120. The manually switchable valve 160 has an opened state and a closed state.

(13) When the valve 160 is in the closed state, the third spray arm 132 is isolated from the second hydraulic arrangement 120, in other words the third spray arm 132 is in the first switching state. When the third spray arm 132 is in the first switching state and the second hydraulic arrangement 120 is supplied with washing liquor by the pump device 140, the washing liquor only passes to the second spray arm 122 and only the second washing zone is provided. A first volumetric flow of washing liquor results as a function of a pump speed of the pump device 140.

(14) When the valve 160 is in the opened state, the third spray arm 132 is connected to the second hydraulic arrangement 120, in other words the third spray arm 132 is in the second switching state. When the third spray arm 132 is in the second switching state and the second hydraulic arrangement 120 is supplied with washing liquor by the pump device 140, the washing liquor passes to the second spray arm 122 and to the third spray arm 132, providing both the second washing zone and the intensive washing zone. A second volumetric flow of washing liquor results as a function of the pump speed.

(15) If the pump speed is the same in both switching states of the third spray arm 132, the second volumetric flow is greater than the first volumetric flow. The greater volumetric flow requires a higher consumption of electrical energy. As the terminal voltage of the pump device 140 is constant or essentially constant when the pump speed is constant, the greater electrical energy is supplied by an increased pump current 142 (see FIG. 3). It is therefore possible to conclude the current switching state of the third spray device 132 from the pump current 142.

(16) In order to exclude error sources, which can result in an increased pump current 142, for example sluggishness of the pump device 140, a manner of calibration is performed on the pump current 142. To this end the pump current 142 required to supply the hydraulic arrangement 110, 120, to which the third spray device 132 is not assigned, is detected as the reference pump current. In the present exemplary embodiment this is the first hydraulic arrangement 110. The reference pump current is detected again every time the current switching state of the third spray device 132 is determined.

(17) The third spray device can alternatively also be assigned to the first hydraulic arrangement 110 (not shown). The pump current 142 required to supply the second hydraulic arrangement 120 is then detected as the reference pump current.

(18) FIG. 3 shows a schematic exemplary diagram D of a pump current 142 over a time period from a start time to t.sub.0 an end time t.sub.2. The illustrated pump current 142 is detected for example during operation of a household dishwasher 1 in FIG. 1 or FIG. 2. At a switching time t.sub.1, which is between the start time to and the end time t.sub.2, a water switch for example is repositioned, so that washing liquor is supplied to the second hydraulic arrangement 120 instead of the first hydraulic arrangement 110. In other words during the period t.sub.0-t.sub.1 washing liquor is supplied to the first hydraulic arrangement 110 and during the period t.sub.1-t.sub.2 washing liquor is supplied to the second hydraulic arrangement 120.

(19) The pump current 142 is shown on the y-axis of the diagram D. Three values I.sub.0, I.sub.1 and I.sub.2 in particular are marked. In this example I.sub.0 for example corresponds to the pump current 142 required to supply the first hydraulic arrangement 110 with washing liquor. This pump current 142 can also be referred to as the first pump current I.sub.0. I.sub.1 for example corresponds to the pump current 142 required to supply the second hydraulic arrangement 120, when the third switching device 132 is in the first switching state, in other words isolated from the second hydraulic arrangement 120. I.sub.2 for example corresponds to the pump current 142 required to supply the second hydraulic arrangement 120, when the third switching device 132 is in the second switching state, in other words connected to the second hydraulic arrangement 120. I.sub.1 and I.sub.2 can also be referred to as the second pump current.

(20) Diagram D shows how the pump current 142 changes at switching time t.sub.1, when the switch is made from the first hydraulic arrangement 110 to the second hydraulic arrangement 120. It shows both possibilities in respect of the current switching state of the third spray device 132, the continuous line showing the pump current 142 in the first switching state and the broken line showing the pump current 142 in the second switching state. It can be seen that the pump current 142 is different in the two switching states. The difference ΔI.sub.01, ΔI.sub.02 is also shown for each switching state. The resulting difference ΔI.sub.01, ΔI.sub.02 is greater, the faster the pump speed of the pump device 140. In this sense it can be advantageous to increase the pump speed when determining the current switching state of the third spray device 132.

(21) The control device 150 (see FIG. 1) is designed in particular to determine this difference ΔI.sub.01, ΔI.sub.02 and to determine the current switching state of the third spray device 132 as a function of the magnitude or size of the difference ΔI.sub.01, ΔI.sub.02. For example the control device 150 compares the determined difference ΔI.sub.01, ΔI.sub.02 with a predetermined threshold value for this purpose.

(22) The concept described with reference to FIGS. 1 to 3 can be extended to any number of hydraulic arrangements 110, 120, of which any except one can have an additional, for example manually switchable, spray device assigned to it. It is therefore sufficient for one of the hydraulic arrangements 110, 120 to have a clearly defined and unchangeable state, so that a reference pump current can be detected when said hydraulic arrangement 110, 120 is supplied with washing liquor.

(23) It is also conceivable for a fourth spray device to be assigned for example to the second hydraulic arrangement 120 and to have two switching states like the third spray device 132. The control device 150 is then designed for example to determine, as a function of the difference between the pump current 142 when the first hydraulic arrangement 110 is supplied with washing liquor and when the second hydraulic arrangement 120 is supplied with washing liquor, whether the third spray device 132 or the fourth spray device is in the second switching state or whether the third spray device 132 and the fourth spray device are in the second switching state.

(24) FIG. 4 shows a block diagram of an exemplary method for operating a dishwasher 1, for example a household dishwasher according to FIG. 1 or FIG. 2. The exemplary method allows a control device 150 to determine a current switching state of a third spray device 132 as a function of a difference ΔI.sub.01, ΔI.sub.02 between the pump current 142 when the first hydraulic arrangement 110 is supplied with washing liquor and when the second hydraulic arrangement 120 is supplied with washing liquor.

(25) The method comprises the following method steps S1-S5 for example. In a first method step S1 washing liquor is supplied to the hydraulic arrangement 110. To this end a pump device 140 is operated at a predetermined speed. In a second method step S2, which takes place in particular during the performance of the first method step S1, the control device 150 detects the pump current 142 required to operate the pump device 140 when the first hydraulic arrangement 110 is supplied. The control device 150 in particular detects a first pump current I.sub.0. Provision can be made here in particular for the control device 150 to detect the pump current 142 over a predetermined time interval and to detect a temporal mean value of the pump current 142 in this time interval. Provision can also be made for the control device 150 to monitor the smooth running of the pump device 140 while the pump current 142 is detected. In a third method step S3 the second hydraulic arrangement 120 is supplied with washing liquor. During this process the pump device 140 is operated in particular at the same pump speed as in method steps S1 and S2.

(26) In a fourth method step S4, which takes place in particular during the performance of the third method step S3, the control device 150 detects the pump current 142 required to operate the pump device 140 when the second hydraulic arrangement 120 is supplied. The control device 150 in particular detects a second pump current I.sub.1, I.sub.2. The exemplary embodiments cited for the second method step S2 apply accordingly to the fourth method step S4. In a fifth method step S5 the control device 150 determines the current switching state of the third spray device 132 as a function of the difference ΔI.sub.01, ΔI.sub.02 between the pump currents 142, in particular the first pump current I.sub.0 and the second pump current I.sub.1, I.sub.2. To this end for example the control device 150 forms a difference between the first pump current I.sub.0 and the second pump current I.sub.1, I.sub.2 and compares the result with a predefined threshold value. The control device 150 can determine the current switching state depending on whether the difference is greater than the threshold value or smaller than the threshold value.

(27) Although the present invention has been described based on exemplary embodiments, it can be modified in many different ways.