Dishwasher comprising a sensor unit for determinig a rotation movement of a spray arm

Abstract

The invention proposes a dishwasher comprising a working chamber (2), comprising at least one spray arm (5, 6) which is arranged in a rotatable manner in the working chamber (2), and comprising a metering apparatus (9) for supplying and metering a substance, such as detergent, rinse aid etc., into the working chamber (2), wherein the metering apparatus (9) is designed as an insert part (9) comprising a housing (20, 21) for insertion into a recess in an inner wall (7) of the working chamber (2), for example in the door (7) of the warning chamber (2), and comprising a sensor unit (27, 28) for identifying a spray arm movement in the working chamber (2) of the dishwasher, which sensor unit is arranged at least partially in a housing (20, 21) of the metering apparatus (6), wherein the dishwasher has improved program control. According to the invention, this is achieved in that at least one inlet opening (17) in an interior (22) of the metering apparatus (9) is arranged at least partially in the jet (23) of water/liquid from a spray nozzle (24) of the spray arm (5, 6) during the rotation of the spray arm (5, 6), wherein the sensor unit (27, 28) is arranged at least partially in the/on the interior (22) and/or on a wall of the interior (22).

Claims

1. A dishwasher comprising a working chamber (2), comprising at least one spray arm (5, 6) which is arranged in a rotatable manner in the working chamber (2), and comprising a metering apparatus (9) for supplying and metering a substance, such as detergent, rinse aid etc., into the working chamber (2), wherein the metering apparatus (9) is designed as an insert part (9) comprising a housing (20, 21) for insertion into a recess in an inner wall (7) of the working chamber (2), for example in the door (7) of the working chamber (2), and comprising a sensor unit (27, 28) for identifying a spray arm movement in the working chamber (2) of the dishwasher, which sensor unit is arranged at least partially in a housing (20, 21) of the metering apparatus (6), characterized in that at least one inlet opening (17) in an interior (22) of the metering apparatus (9) is arranged at least partially in the jet (23) of water/liquid from a spray nozzle (24) of the spray arm (5, 6) during the rotation of the spray arm (5, 6), wherein the sensor unit (27, 28) is arranged at least partially in the/on the interior (22) and/or on a wall of the interior (22).

2. The dishwasher according to claim 1, characterized in that the interior (22) has at least one drain opening (15) for draining/outflow of the water/liquid.

3. The dishwasher according to claim 2 characterized in that the drain opening (15) and/or the interior (22) have/has at least one restrictor apparatus (26) for building up and/or restricting the water/liquid in the interior (22).

4. The dishwasher according to claim 1 wherein the sensor unit (27, 28) comprises at least one conductance sensor for detecting a conductance of the water/liquid.

5. The dishwasher according to claim 1 wherein the sensor unit (27, 28) comprises at least one pressure sensor for detecting a water/liquid pressure.

6. The dishwasher according to claim 1 wherein the sensor unit (27, 28) comprises at least one optical sensor apparatus for detecting the water/liquid.

7. The dishwasher according to claim 1 wherein the housing (20, 21) of the metering apparatus (9) has guide elements (16) in order to keep the interior (22) and/or the sensor unit (27, 28) at least partially free of water running off from the housing (20, 21).

8. The dishwasher according to claim 7 wherein the guide elements (16) are designed as a roof (16) over the inlet opening (177) through which the jet of water/liquid passes and/or over the interior (22).

9. The dishwasher according to claim 1 wherein the sensor unit (27, 28) is arranged such that it is not situated directly in a jet of water/liquid from a spray arm nozzle (24, 30).

10. The dishwasher according to claim 1 further comprising a time sequence of the sensor signal is detected and an evaluation unit is provided in order to detect the periodicity and/or frequency of the sensor signal which is induced by the rotating splay arm (5, 6).

11. The dishwasher according to claim 1 further comprising an analog evaluation circuit.

12. A metering apparatus (9) for supplying and metering a substance, such as detergent, rinse aid etc., into a working chamber (2) of a dishwasher according to one of the preceding claims, which metering apparatus is designed as an insert part (9) comprising a housing (20, 21) for insertion into a recess in an inner wall (7) of the working chamber (2), for example in the door (7) of the working chamber (2), and comprises a sensor unit (27, 28) for identifying a spray arm movement in the working chamber (2) of the dishwasher, which sensor unit is arranged at least partially in the housing (20, 21), characterized in that at least one inlet opening (17) in an interior (22) of the metering apparatus (9) is arranged at least partially in the jet (23) of water/liquid from a spray nozzle (24) of the spray arm (5, 6) during the rotation of the spray arm (5, 6), wherein the sensor unit (9) is arranged at least partially in the/on the interior (22) and/or on a wall of the interior (22).

Description

[0043] An exemplary embodiment of the invention is illustrated in the drawing and will be explained in more detail below with reference to the figures.

[0044] Specifically:

[0045] FIG. 1 shows a schematic cross section through a warewasher comprising a spray arm,

[0046] FIG. 2 shows a schematic plan view of the inside of the door of a warewasher,

[0047] FIG. 3 is a schematic illustration of a metering apparatus in cross section together with a spray arm, and

[0048] FIG. 4 shows a schematic example of a sensor signal which can be generated by means of a water build-up sensor.

[0049] FIG. 1 schematically illustrates a warewasher 1 comprising a dishwashing chamber 2 in section. Two dish racks 3, 4 are located in the dishwashing chamber 2, and a spray arm 5, 6 is arranged in a rotatable manner beneath each of said dish racks.

[0050] A warewasher door 7 is fitted to the front side of the dishwashing chamber 2 in a rotatable manner, as is indicated by a rotation axis 8. A metering apparatus 9 for adding dishwashing agent is located in the warewasher door 7.

[0051] A sump container 11 is located in the base 10 of the warewasher 1, said sump container containing, for example, the customary filters and a water outlet 12.

[0052] FIG. 2 shows the arrangement of the metering apparatus 9 in a plan view of the door 7. The metering apparatus 9 is inserted into the warewasher door 7, as already described with reference to FIG. 1. The metering apparatus 9 comprises a housing upper part 20 of a housing 21 and, on its top side in a customary manner, a flap 14 or cover 14 for closing a dishwashing agent chamber and a flap 13 for closing a rinse aid chamber.

[0053] An evaluation and control unit 18 or an operator control unit 18 for the user/operator can also be arranged in the interior of the warewasher door 7, as indicated in FIG. 1. In the location of the evaluation and control unit 18 indicated in FIG. 1, said evaluation and control unit can be connected directly to the displays, buttons and other operator control elements required to operate the machine.

[0054] FIGS. 2 and 3 additionally illustrate the arrangement of an inlet opening 17 and a drain opening 15 of an interior 22 according to the invention of the metering apparatus 9. In FIG. 2, a canopy 16 or a drip tray 16 is arranged separately above the inlet opening 17. In FIG. 3, the canopy 16 or the drip tray 16 is integrated/integrally formed virtually in the form of a “nose” or drain protection means directly in/with a housing upper part 20 of the housing 21 or is designed as an upper edge of the inlet opening 17 of the interior 22 according to the invention of the metering apparatus 9. The canopy 16 serves as a guide element in order to divert water or washing solution which is running down.

[0055] As is clear primarily in FIG. 3, a jet 23 of water or liquid from a spray nozzle 24 which is arranged on the end of the rotating spray arm 5, 6 passes directly through the inlet opening 17 into the interior 22 of the apparatus 9. Other jets 29 of water or liquid from spray nozzles 30 which are arranged more centrally on the rotating spray arm 5, 6 do not pass through the inlet opening 17 into the interior 22 of the apparatus 9.

[0056] The water/liquid/washing solution which has entered the interior 22 collects in a build-up region 25 which has a restrictor point 26 or narrow point 26 on its lower section, so that the water/liquid collects/builds up in the interior 22 (in a defined manner) as schematically depicted. A drain 21 comprising the drain opening 15 of the interior 22 is provided “behind” or “beneath” the narrow point 26 in the direction of flow.

[0057] The narrow point 26 has a prespecified clear/free cross section, so that, by virtue of the spray arm 5, 6 which rotates past, enough water/liquid collects/builds up above the narrow point 26 in order to detect the presence of the built-up water/liquid in the build-up region 25 using a build-up sensor 27 or an alternative sensor 28. The sensor 27 is preferably arranged in the build-up region 25, said sensor being designed, amongst other things, as a light barrier, pressure sensor or conductance sensor. The water/liquid flows away automatically through the drain or the outflow opening 15, so that the build-up region 25 is emptied again or the filling level of the built-up water/liquid drops again.

[0058] This build up and outflow again takes place periodically in the case of a properly rotating spray arm 5, 6. FIG. 4 schematically shows an exemplary sensor signal of a sensor 27 which is designed as a conductance sensor, wherein a periodic change in signal or respectively a signal peak P.sub.1 and P.sub.2 owing to a lower and an upper spray arm 5, 6 can be identified. When the spray arm 5, 6 is stationary or damaged, the corresponding signal peak P.sub.1 and/or P.sub.2 would be absent. This can be detected/evaluated and possibly signaled by means of an advantageous checking unit.

[0059] The sensor 28, in a manner designed, for example, as a proximity sensor 28 and/or by means of distance measurement or level detection of the built-up volume or water/liquid, can likewise detect/monitor the rotation of the spray arm 5, 6.

[0060] In principle, a sensor 27, 28 can be used to detect and evaluate both a rotation of the rotary arm 5, 6 and advantageously a pump pressure or water/liquid pressure, in particular the level of the build-up region 25 and/or the distance from the surface of the built-up volume or water/liquid, is a parameter which can be advantageously evaluated. Therefore, a pump pressure or pressure of the jet 23 is also substantially proportional to the sensor signal P (cf. FIG. 4). A conclusion about or monitoring of the pump or its function, in particular problem-free operation, can advantageously be generated as a result.

[0061] FIG. 4 illustrates, by way of example, a time sequence of a sensor signal. The horizontal axis of the graph shows the time t, while the vertical axis illustrates the intensity I. The sensor signal or a schematically illustrated envelope of the sensor signal exhibits different peaks P.sub.1 and P.sub.2 which are each arranged periodically as a function of time t. The respective time points t1 to t4 are correspondingly marked.

[0062] Interference peaks which are not illustrated in more detail could be identified and eliminated by suitable evaluation by means of the evaluation unit 18. This evaluation can be configured, for example, in such a way that only periodically recurring signals P1 and P2 are perceived as real sensor signals, non-periodic signals however being perceived as interference signals. Another way of identifying the interference signals involves, for example, integrating the corresponding signal peaks with respect to time, as a result of which the area which is covered by the peaks is mathematically determined. Since an integral value is to be expected within a specific interval given regular sensor signals, other signals, such as linear interference signals for example, can be identified and ruled out in this way.

[0063] These exemplary methods or else further methods for identifying interference signals, for example by means of threshold values in respect of the intensity or the like, can be used on their own or else in combination with one another.

[0064] If a malfunction, for example a stationary spray arm or a spray arm which is rotating too slowly, is identified on the basis of the sensor signal, this can be displayed to the operator in a display or by the operator control unit 18.

[0065] The warewasher according to the invention can also be controlled depending on the sensor signal. For example, the quantity of water and/or the pump pressure can be varied. Nozzles which are controllable in respect of the orientation of the jet and/or shape of the jet are also optionally conceivable.

LIST OF REFERENCE SYMBOLS

[0066] 1 Warewasher [0067] 2 Dishwashing chamber [0068] 3 Dish rack [0069] 4 Dish rack [0070] 5 Spray arm [0071] 6 Spray arm [0072] 7 Warewasher door [0073] 8 Rotation axis [0074] 9 Metering apparatus [0075] 10 Base [0076] 11 Sump container [0077] 12 Outflow [0078] 13 Flap [0079] 14 Flap [0080] 15 Outflow opening [0081] 16 Canopy [0082] 17 Inlet opening [0083] 18 Evaluation and control unit [0084] 20 Housing upper part [0085] 21 Housing [0086] 22 Interior [0087] 23 Jet of water [0088] 24 Nozzle [0089] 25 Build-up region [0090] 26 Narrow point [0091] 27 Sensor [0092] 28 Sensor [0093] 29 Jet of water [0094] 30 Nozzle [0095] t Time [0096] I Intensity [0097] P1 Peak [0098] P2 Peak [0099] t1 Time point [0100] t2 Time point [0101] t3 Time point [0102] t4 Time point