WO2012107264A1

WO2012107264A1 - Dishwasher and method for detecting faults in a dishwasher

Info

Publication number: WO2012107264A1
Application number: PCT/EP2012/050788
Authority: WO
Inventors: Andreas Heidel; Reinhard Hering; Bernd KRÄNZLE
Original assignee: BSH Bosch und Siemens Hausgeräte GmbH
Priority date: 2011-02-07
Filing date: 2012-01-19
Publication date: 2012-08-16
Also published as: EP2672875B1; PL2672875T3; DE102011003688A1; EP2672875A1

Abstract

The invention relates to a dishwasher, comprising a dishwashing compartment (1) in which items to be cleaned can be arranged, and a liquid circuit for supplying liquid to the items to be cleaned, wherein at least one machine-driven circulation pump (13) for delivering the liquid is connected in the liquid circuit. During a partial filling phase, the dishwashing compartment (1) can be filled by a water feeding means (15, 16) with a water quantity (Δm) which is less than an operating water quantity for cleaning items to be washed. During a test phase following the partial filling phase, at least one operating parameter (P) of the circulation pump (13) or of a drive unit associated with the circulation pump (13) is recorded with the aid of a sensor system (31), wherein the at least one operating parameter (P) can be varied depending on a volume flow delivered in the liquid circuit. An evaluation unit (32) then detects an excessive water supply to the dishwasher compartment (1) depending on the at least one recorded operating parameter (P).

Description

Dishwasher and method for fault detection in one

dishwasher

The invention relates to a dishwasher, in particular a domestic dishwasher, with a rinsing container in which to be cleaned items can be arranged, and with a liquid circuit for applying to be cleaned ware with liquid, wherein in the liquid circuit at least one mechanically driven circulation pump for conveying the Liquid is switched. Dishwashers can be connected via fresh water supply lines to the water supply network. If the inflow of water through the fresh water supply line is excessively large, the supply of water may be incorrectly over-inflated, which may result in malfunctioning of the rinse container overflowing with water and a resulting "overflow" of the dishwasher Repair customer service.

The object of the invention is to provide a dishwasher, in particular a domestic dishwasher, as well as a method for fault detection in a dishwasher, by means of which an excessive water supply is detected in a simple manner.

According to the invention, the dishwasher water supply means, for example in the form of a fresh water supply with a water inlet valve provided therein, by means of which the rinsing is filled during a Teilfüllphase in a predetermined period of time with a quantity of water that is less than an amount of operating water for cleaning items to be washed. Subsequently, as part of a test procedure, at least one operating parameter of the circulating pump or of a drive unit assigned to the circulating pump is detected as a function of a volumetric flow conveyed in the fluid circuit and thus also dependent on the quantity of water supplied. The amount of operating water is so dimensioned that the circulation pump operated in a non-air-sucking concentricity can be. In contrast, the supplied during the Teilfüllphase amount of water is such that the circulating pump sucks air and thus can not be operated in the concentricity, but is so large that changes in the amount of water supplied a change in the operating parameters of the circulation pump or the associated drive unit, eg the power consumption of the circulation pump driving electric motor, the result. Thus, the amount of water can be such that they z. B. is smaller than the amount of operating water by a factor of 5-20, which is required to clean items in the dishwasher.

The partial filling of the washing container can be effected in that a control device of the dishwasher opens a water inlet valve in the fresh water supply line during the partial filling phase. For detecting operating parameters, at least one sensor system is provided, and an evaluation unit is provided for evaluating the operating parameters or variables derived therefrom. The partial filling of the washing container according to the invention ensures that an excessive supply of water can be reliably detected without there being any "real" overfilling of the washing container with the potential risk of overflow of the dishwasher. The operating parameters are, for example, the electric current consumption or the electrical power of the electric motor derived therefrom, which change substantially in proportion to the load on the pump and thus proportionally to the delivered volume flow Partial filling phase supplied excessively much water, so the circulation pump must deliver correspondingly much water and thus a correspondingly high volume flow, whereby their current consumption and power is correspondingly large e Power consumption and power low when only a reduced amount of water is supplied during the partial filling process. Alternatively to the electrical power consumption or electrical power, the operating parameter may also be an electrical voltage, a torque and / or a rotational speed of the drive motor of the circulation pump. Of course you can too several such operating parameters, possibly by a plurality of sensor systems, detected and further processed in the evaluation.

The invention thus also makes it possible to determine the water volume flow in the fresh water supply line by evaluating operating parameters of already existing device components. This determination can be made, for example, by the evaluation unit. Thus, an additional flow meter, such as an impeller counter, can be dispensed with. Instead, you can. Alternatively, however, a direct detection of the supplied water volume flow can take place, e.g. by an impeller meter, which is arranged in a line section of the dishwasher.

The operating parameters detected by the sensor, such as the current consumption of the drive motor of the circulation pump, or a variable derived therefrom, such as. the electrical power of the drive motor of the circulation pump or the water volume flow in the fresh water supply line can be compared by the evaluation unit with a limit value. When the limit value is exceeded, an excessive water supply to the washing container can be detected. In this case, the limit value can correspond to a desired amount of water to be supplied during the partial filling phase in the fault-free state. Such a desired amount of water results at a given water line pressure and error-free operation of the device components involved in the fresh water supply. The involved device components may be e.g. a water inlet valve and / or a pressure reducer, which may be provided separately from the water inlet valve or integrated therein. Upon detection of an excessive water supply to the rinsing container, an error signal can be generated, which indicates that the guided to the dishwasher water flow and thus the amount of water supplied are excessively large. The error signal can also be output as an error message. The error signal can also be stored so that it can be read at a later time, e.g. from customer service, can be retrieved.

In a preferred embodiment, the method according to the invention is carried out automatically before the beginning of each rinse cycle. In this case, the partial filling of the rinsing container in the Teilfüllphase preferred for accurate detection deactivated, ie switched-off circulating pump, done. After the partial filling phase, the dishwasher is filled to a certain level with the amount of water supplied. At the beginning of the test phase following the partial filling phase, the circulating pump is activated, that is to say switched on, and then remains activated during the test phase at least until the operating parameter of the circulating pump or its drive unit is detected.

For the accuracy of measurement, it is important that an aging and / or a certain stiffness of the circulation pump is taken into account in the course of their life. Against this background, the circulation pump can be calibrated before the beginning of a partial filling phase. For this purpose, liquid can be conveyed out of the dishwasher before the partial filling phase by activation of a drain pump and thus the washing container can be completely emptied. As a result, the circulation pump can be operated in an idle mode in order, for example, to perform pump calibration during pump calibration. to detect the current consumption of the drive motor in idle mode. To empty the washing container, the drain pump can first withdraw liquid from the dishwasher when the circulating pump is switched off. Subsequently, the circulation pump can be turned on to confirm the empty state of the washing container based on the monitored operating parameters. Further features and advantages of the invention will become apparent from the following description of an embodiment with reference to the accompanying figures.

1 shows a schematic block diagram of a dishwasher according to the invention; and

Fig. 2 is a flowchart for error detection according to the invention in a dishwasher.

FIG. 1 shows a dishwasher with a washing container 1 delimiting a washing compartment. In the washing compartment of the washing container 1, a not shown to be cleaned dishes in dish racks 3, 5 are arranged. In the shown rinsing Container 1 are exemplified two, provided in different spray levels spray arms 7, 8 are arranged, via which the wash ware is treated with rinsing liquid. In Spülbehälterboden a pump pot 11 with only roughly indicated sieve assembly 10 is provided. Starting from the pump pot 1 1, a circulation line 9 with circulating pump 13 arranged therein and downstream water heater 12 is led away. Downstream of the water heater 12, a water distributor 21 is provided, branch off at the two supply lines 14 of the circulation line 9. About the supply lines 14, the circulation line 9 is connected to the spray arms 7, 8. The rinsing liquid sprayed out of the spray arms 7, 8 collects on the rinsing container bottom and is introduced again via the pumping pot 11 into the circulation line 9, so that a liquid circuit is formed.

On the pump pot 11 also connected to the water supply network fresh water supply line 16 and a drain line 17 is provided, in which a drain pump 18 is arranged for pumping out rinsing liquid from the washing compartment 1. In the fresh water supply line 16, a water inlet valve 15 is arranged, which forms a water supply means together with the fresh water supply line 16.

In the water inlet valve 15 is a not-shown, known pressure reducer integrated, which can reduce a required during a rinse water volume flow rh to the dishwasher.

To carry out a rinse cycle, the dishwasher has a control device 27 with which the program steps known per se, namely pre-rinsing, cleaning, intermediate rinsing, rinsing and drying, can be carried out. For this purpose, the control device 27 can control the respective device components via signal lines 26 shown in dashed lines.

1, both the circulation pump 13 and the drain pump 18 each have a drive unit in the form of an electric motor 28 or 28 ', which drive the respective pump 13 or 18 via drive shafts 29 and 29'. The electric motors 28, 28 'can be designed, for example, as so-called BLDC motors, that is, brushless three-phase synchronous motors. The electric motors 28, 28 'may also be assigned not shown inverter or inverter, the respective Electric motor 28 and 28 'supply with electrical energy. The converters or inverters thereby generate the required electrical three-phase voltages for the respective electric motor 28 or 28 ', ie electrical voltages with the required frequency and the required effective value. About the inverter or inverter, the controller 27 can control the electric motors 28 and 28 'of the pump 13 and 18, optionally also regulate.

By sensors 31 and 31 ', in each case an electrical current consumption I or Γ of the respectively associated electric motor 28 or 28' can be detected during pump operation. The thus detected electrical current consumption I and Γ be performed as operating parameters via signal lines 30 and 30 'to the controller 27 and evaluated there in an evaluation unit 32. Optionally, the water volume flow rh in the fresh water supply line can also be determined by the evaluation unit 32, which enters the liquid circuit of the dishwasher during the wash cycle with the water inlet valve 15 open. In the illustrated embodiment, the evaluation unit 32 is integrated into the control device 27. Alternatively, however, the evaluation unit 32 can also be realized separately.

An embodiment of the method for error detection according to the invention will now be described with reference to FIG. First, in a first method step, the rinsing container 1 together with the sump 11 is completely emptied of liquid located therein. To empty the washing container 1, the drain pump 18 is activated by means of the control device 27, while the circulating pump 13 is deactivated, i. remains off. On the basis of the detected by the sensor 31 'current consumption Γ of the electric motor 28' of the drain pump 18 can be determined by an evaluation, preferably the evaluation unit 32, at which time the drain pump 18 has sucked all the liquid from the washing compartment 1. To check the empty state, the circulating pump 13 can then be activated, in which case the empty state of the dishwasher can be confirmed on the basis of the current consumption I of the circulating pump 13 detected with the aid of the sensor system 31.

When the circulating pump 13 is idle, ie when the rinsing container 1 is completely emptied, a pump calibration can be carried out, in which an operating parameter P of the Circulating pump 13 driving electric motor 28 detected in the form of the electric current consumption I of the electric motor 28 in the idle mode of the circulating pump 13 as a reference value and can be stored in the control device 27.

After the pump calibration, a partial filling phase is started in which the control device 27 opens the water inlet valve 15 for a predetermined first time interval, whereby during the first time interval an amount of water λm is introduced into the washing container 1. In this case, the amount of water Äm is smaller than an amount of operating water, which is required to clean dishes in the dishwasher. The circulation pump 13 is deactivated during the partial filling phase.

After expiration of the first time interval Eti, the water inlet valve 15 is closed again and a test phase is started. For this purpose, first the circulating pump 13 is activated for a second time interval At ₂ . As part of the test phase, the operating parameter P in the form of the current consumption I of the electric motor 28 of the circulating pump 13 is detected with the aid of the sensor system 31. The current consumption I of the electric motor 28 of the circulation pump 13 behaves proportionally to the voltage applied to the circulation pump 13 load. That is, for a large volume flow in the liquid circuit, the current consumption I of the electric motor 28 is correspondingly large, while at low flow in the liquid circuit, the current consumption I of the electric motor 28 is correspondingly low.

The detected current consumption I of the electric motor 28 of the circulating pump 13 is supplied to the evaluation unit 32 and compared by this with a limit value. When the limit value is exceeded, a fault is detected in which, in the partial filling phase during the first time interval A, an excessive, ie excessively large, amount of water A m is supplied. Such an excessive water supply results, for example, when the pressure reducer in the water supply line 16 is defective or removed. Upon detection of an excessive water supply, the water supply is stopped, for example by the water inlet valve 15 is closed by the controller 27. In addition, an error signal generated and z. B. in the evaluation unit 32 or the control device 27 is stored. The error signal or the error information contained is then available eg for customer service and can be output. The abovementioned limit value is dimensioned such that it corresponds approximately to a nominal amount of water to be supplied during normal operation during the first time interval et.sub.i, ie in the fault-free state.

By way of example, this limit value can be chosen such that the nominal amount of water A m supplied during the partial filling phase is 300 ml during normal operation. During normal operation, that is to say in the case of a properly functioning water supply means, this quantity of water is thus fed into the washing container 1 during the partial filling process. The detected during subsequent activation of the circulation pump 13 current consumption I is thus correspondingly lower in normal operation than in the event of a fault.

In the event of an error, ie, for example, when the pressure reducer is defective or removed, an amount of water which is substantially larger than the abovementioned 300 ml is supplied during the partial filling phase in the first time interval Ati. In this case, after activation of the circulating pump 13, the detected current consumption I would be substantially greater than the limit value, whereby it can be concluded that an error has occurred in the form of an excessive water supply.

LIST OF REFERENCE NUMBERS

1 washing container

3, 5 baskets

7, 8 spray arms

10 sieve arrangement

1 1 pump pot

12 water heating

13 circulation pump

14 supply lines

15 water inlet valve

16 fresh water supply

18 lye pump

21 water switch

26 signal lines

27 control device

28, 28 'electric motors

29, 29 'drive shafts

30, 30 'signal lines

31, 31 'sensors

32 evaluation unit

A first time interval

At ₂ second time interval

P operating parameters

I current consumption

Claims

Dishwasher, in particular domestic dishwasher, with a rinsing container (1), in which to be cleaned items can be arranged, and a liquid circuit for applying the cleaning agent to be cleaned with liquid, wherein in the liquid circuit at least one mechanically driven circulating pump (13) for conveying the Liquid is connected, characterized by

Water supply means (15, 16) through which the rinsing tank (1) can be filled in a partial filling phase with an amount of water (λm) which is less than a quantity of operating water for cleaning items to be washed,

a sensor system (31) which detects at least one operating parameter (I) of the circulation pump (13) or drive unit associated with the circulating pump (13) in a test phase following the partial filling phase, the at least one operating parameter (P) being dependent on a fluid pumped in the fluid circuit Volumetric flow is variable, and

an evaluation unit (32) which detects an excessive water supply to the washing container (1) as a function of the at least one detected operating parameter.

Dishwasher according to claim 1, characterized in that the at least one operating parameter (P) is an operating parameter (P) of an electric motor (28) driving the circulating pump (13).

Dishwasher according to claim 2, characterized in that the at least one operating parameter (P), the electrical current consumption (I) of the circulating pump (13) driving the electric motor (28).

Dishwasher according to one of claims 1 to 3, characterized in that the evaluation unit (32) for comparing the at least one operating parameter (P) or a size derived therefrom with a limit value is formed, and that the evaluation unit (32) detects an excessive water supply to the washing container (1) when the limit value is exceeded.

Dishwasher according to one of the preceding claims, characterized in that the dishwasher has a control device (27) which stops the supply of water upon detection of an excessive water supply, the

Dishwasher according to one of the preceding claims, characterized in that the evaluation unit generates an error signal upon detection of an excessive water supply.

Dishwasher according to one of the preceding claims, characterized in that the dishwasher has a drain pump (18), by the activation of the washing container (1) is completely emptied before the partial filling.

Method for fault detection in a dishwasher, in particular a domestic dishwasher, which has a rinsing container (1), in which to be cleaned items can be arranged, and a liquid circuit for applying the cleaning items to be cleaned with liquid, wherein in the liquid circuit at least one machine driven circulation pump (13) is connected for conveying the liquid, in which

in a Teilfüllphase the washing container (1) is filled with an amount of water (Äm), which is less than an amount of operating water for cleaning items to be washed, and

in a test phase following the partial filling phase

• at least one operating parameter (P) of the circulating pump (13) or of a drive unit associated with the circulating pump (13) is detected, which is variable as a function of a volume flow conveyed in the liquid circuit, and

• an excessive water supply to the washing container (1) is detected if the at least one detected operating parameter (P) or a variable derived therefrom exceeds a predefinable limit value.

9. The method according to claim 8, characterized in that in the test phase at least one operating parameter (P) of the circulating pump (13) driving the electric motor (28) is detected. 10. The method according to claim 9, characterized in that in the test phase at least the electrical current consumption (I) of the circulating pump (13) driving the electric motor (28) is detected.

11. The method according to any one of claims 8 to 10, characterized in that upon detection of an excessive water supply, the water supply is stopped.

12. The method according to any one of claims 8 to 1 1, characterized in that upon detection of an excessive water supply, an error signal is generated. 13. The method according to claim 12, characterized in that the error signal is stored.

14. The method according to any one of claims 8 to 13, characterized in that the circulation pump (13) is deactivated during the partial filling, is activated at the beginning of the test phase and remains activated at least for a portion of the test phase.

15. The method according to any one of claims 8 to 14, characterized in that before demrTeilfüllphase

- The washing container (1) is completely emptied by activating a drain pump (18) and

the at least one operating parameter (P), in particular for pump calibration, is recorded and stored when the circulation pump (13) is idle.