EP2794973B1 - Device for evaluating the hygiene status of water-carrying domestic appliance as well as such an appliance, and a method for evaluating a hygiene status of a corresponding domestic appliance - Google Patents

Description

The invention relates to a device for assessing a hygiene state of a water-bearing domestic appliance, in particular a domestic appliance for the care of laundry items. The invention also relates to a corresponding water-conducting domestic appliance as well as a method for assessing a hygiene state of a water-conducting domestic appliance, in particular a domestic appliance for the care of laundry items.

In a water-bearing domestic appliance, such as a washing machine, other washing equipment for the care and / or cleaning of laundry items or dishes of a coffee machine or other beverage preparation machine, it may come under specific installation and / or operating conditions to form a biofilm. Such a biofilm can be easily recognized, for example, in the dispenser shell of a washing machine by a user, and a corresponding cleaning measure can be taken immediately. For components of a household appliance, which are more difficult to access and also difficult to see, such biofilament detection can be difficult or even impossible due to visual inspection.

Thus, even such a biofilm formation in a tub of a washing machine by a user virtually can not be perceived and is only noticed when an unpleasant odor has arisen.

The later one tries to reduce such biofilm formation by the appropriate measures, the lower the cleaning effect.

A regular use of appropriate care measures, even without the presence of a present need, to a certain extent makes it possible to prevent one such biofilm formation, however, energy is unnecessarily consumed and the environment is polluted by the detergent having chemicals.

It is an object of the present invention to provide a device for assessing a hygiene state of a water-conducting household appliance, such a domestic appliance as well as a method for assessing a hygiene state of a domestic appliance, with which or with which a reliable and early detection of an undesirable hygiene state of hard or non-visible components of a household appliance is achieved.

This object is achieved by a device and a water-conducting domestic appliance as well as a method according to the independent claims.

A device according to the invention for assessing a hygiene state of a water-conducting domestic appliance for the care of laundry items comprises a water guide, in particular a hose, and / or a container, in particular a tub, and an electrical detection device. The detection device is coupled to the water guide and / or the container, in particular tub, and it is designed to carry out a capacitance measurement. It is also designed to assess a hygiene state of the water supply and / or the container, in particular the tub, depending on the capacitance measurement. By means of the device according to the invention, it is now also achieved that components of a household appliance which are difficult or unobservable can be monitored with regard to their hygiene state. In particular, it is now ensured that a reliable and quick statement about the hygiene state is made possible by a relatively simple device. In the context of the invention, a water supply is understood to mean one or more components which can lead or guide water or an aqueous solution.

In addition, the device ensures a very robust method of measurement, especially in a humid environment.

It is preferably provided that the detection device has two conductive electrodes which are connected to the water guide and / or the container, in particular the Lye containers are arranged. These are in particular plate-like. The capacitive measurement can be carried out particularly advantageous. In addition, a corresponding mechanically stable attachment is guaranteed.

The electrodes are preferably arranged on an outer side of the water guide and / or the container, in particular on a rear wall of the suds container. As a result, they are accessible for maintenance and the like. Furthermore, this arrangement in a domestic appliance for the care of laundry no space between the tub and an existing drum for receiving laundry, reduced in size.

Preferably, in a domestic appliance for the care of laundry items is provided that the electrodes are arranged adjacent to a bearing of a tub. This is a particularly advantageous place, as in the area of the bearing of the tub very often unwanted impurities form. The detection of this contamination is thus ensured very quickly.

It is preferably provided that the detection device is designed for the assessment of a property of a biofilm formed on the water guide and / or on the container, in particular on the tub, depending on a measured capacitance.

In particular, it is provided that a characterization of a biofilm formed on the water guide and / or on the container, in particular on the tub, can be carried out as a function of the measuring frequency, depending on a spectrum of the capacitance measured by the detection device. In a preferred manner, it is provided that the detection device has a control unit, whereby a defined spectrum of the measurement frequency can be generated.

Preferably, a characteristic characterizing the biofilm is the composition of the biofilm and / or the thickness of the biofilm and / or the volume density of the biofilm.

The device ensures that a simple, robust and inexpensive way of measuring moisture-containing coverings without direct contact with this medium can be carried out. The concrete relation between measured values and biofilm nature allows a very fast and reliable statement about the extent to which the biofilm has already developed and to what extent more or less comprehensive cleaning measures are required.

In the present invention, the phenomenon is exploited that biofilms remain moist for a while after wetting with water and therefore are electrically conductive. This conductivity can be determined by the capacitance between the two conductive plates representing the electrodes. The measured capacity allows conclusions to be drawn on the coherently wetted area and thus on the areal density of the biofilm. The images of a spectrum, that is, the measurement of the capacitance as a function of the measurement frequency, also allows statements about additional properties, such as the type and / or the thickness and / or the volume density of the biofilm. Low frequencies up to a few megahertz can be included in the frequency spectrum and used for the measurement. Preferably, it is provided by the control unit, which may include a microprocessor, that this frequency control and transmission and thus the measurement over a large frequency interval can be performed. In particular, this is programmed in the microprocessor and thereby minimizes the component-specific effort and the other design.

Furthermore, the invention relates to a water-conducting domestic appliance, in particular a domestic appliance for the care and / or cleaning of laundry items or dishes, such as a washing machine or a dishwasher, or a beverage preparation machine, with a device according to the invention or an advantageous embodiment thereof.

Moreover, the invention relates to a method for assessing a hygiene state of a water-conducting domestic appliance, in which an electrical detection device of the domestic appliance with a water supply and / or a container, in particular a tub, the domestic appliance is electrically coupled and dependent on a capacitance measurement by the detection device of the hygiene state the water supply and / or the container, in particular the tub, is judged.

Advantageous embodiments of the device according to the invention are to be regarded as advantageous embodiments of the method according to the invention.

Fig. 1

eine schematisch perspektivische Darstellung eines Ausführungsbeispiels eines erfindungsgemäßen Hausgeräts;

Fig. 2

eine schematische Ansicht von hinten auf einen Laugenbehälter einer erfindungsgemäßen Vorrichtung mit einer Detektionseinrichtung; und

Fig. 3

eine schematische Schnittdarstellung durch den Laugenbehälter gemäß Fig. 2.

An embodiment of the invention will be explained in more detail with reference to schematic drawings of a washing machine. Show it:

Fig. 1

a schematic perspective view of an embodiment of a domestic appliance according to the invention;

Fig. 2

a schematic view from behind of a tub of a device according to the invention with a detection device; and

Fig. 3

a schematic sectional view through the tub according to Fig. 2 ,

In the figures, identical or functionally identical elements are provided with the same reference numerals.

In Fig. 1 is a front view of a washing machine 1 shown. The washing machine 1 comprises a drum 2 for receiving the laundry items. The drum 2, which is rotatable about an axis perpendicular to the plane of the figure, has a front loading opening 3, via which the items of laundry can be introduced into the drum 2 and taken out.

In addition, the washing machine 1 comprises a tub 4, which surrounds the drum 2 in regions. The washing machine 1 moreover also comprises an induction bowl 5 and an operating device 6.

In addition, the washing machine 1 comprises a device 7, which is designed to assess a hygiene state of the tub 4. The device 7 is based on the FIGS. 2 and 3 explained in more detail.

So is in Fig. 2 a schematic view of the tub 4 shown from the rear. It is thus a rear wall 8, which is opposite to the feed opening 3 shown. The Rear wall 8 is beyond the outside, which faces away from an inner volume 9 of the drum 2 and also of the tub 4. The device 7 comprises in addition to the tub 4, an electrical detection device 10. This is designed for capacitance measurement. It comprises two plates as electrodes 11 and 12, which are formed on the rear wall 8. The plate-like electrodes 11 and 12 are connected via signal lines 13 and 14 to a control and evaluation unit 15. The capacitance measurement by the detection device 10 makes it possible in a very fast and precise manner to make a statement about the hygiene state of the tub 4, in particular about the presence of a biofilm 16 (FIG. Fig. 3 ), as it can form on an inner side 17 of the tub 4, in particular in the region of a bearing 18.

The unit 15 comprises a microprocessor 19. By measuring the capacitance, it is possible to draw conclusions about the coherently wetted surface and thus on the surface density of the biofilm 16. In particular, a spectrum is recorded, for which purpose the capacitance is recorded as a function of the measurement frequency. It is therefore also possible to determine further properties, such as, for example, the type and thus the material composition of the biofilm 16 and / or the thickness of the biofilm 16 and / or the volume density of the biofilm 16.

The described embodiment can be applied mutatis mutandis to other water-bearing household appliances.

LIST OF REFERENCE NUMBERS

1

Washing machine

2

drum

3

loading port

4

tub

5

dispenser tray

6

operating device

7

contraption

8th

rear wall

9

internal volume

10

detection device

11, 12

plates

13, 14

signal lines

15

Control and evaluation unit

16

biofilm

17

inside

18

camp

19

microprocessor

Claims (13)

1. Apparatus (7) for assessing a hygiene state of a water-conducting domestic appliance (1), wherein the apparatus (7) comprises at least one part (4) which can conduct or guide water or an aqueous solution and which is configured in the form of a hose or container, and an electric detection facility (10), which is coupled to the part (4), characterised in that the detection facility (10) is configured to perform a capacitance measurement and to assess the hygiene state of the part (4), as a function of the capacitance measurement, which means that the detection facility (10) is configured to perform an assessment, as a function of a measured capacitance, of a property of a biofilm (16) formed on the inner face (17) of the part (4).
2. Apparatus (7) according to claim 1, wherein the detection facility (10) has two conductive electrodes (11, 12), which are arranged on an outer face of the part (4).
3. Apparatus (7) according to one of the preceding claims, characterised in that the container (4) is a tub.
4. Apparatus (7) according to claim 3, wherein the electrodes (11, 12) are arranged on an outer face of the one rear wall (8) of the tub (4).
5. Apparatus (7) according to claim 4, wherein the vessel is a tub of a domestic appliance for the care of laundry items and the electrodes (11, 12) are arranged adjacent to a bearing (18) of the tub (4).
6. Apparatus (7) according to one of the preceding claims, wherein it is possible to characterise a biofilm (16) formed on the part (4), as a function of a capacitance spectrum measured by the detection facility (10) based on the measurement frequency.
7. Apparatus (7) according to claim 6, wherein the detection facility (10) has a control unit (19), in particular a microprocessor, allowing a defined measurement frequency spectrum to be generated.
8. Apparatus (7) according to one of claims 1 to 7, wherein a property characterising the biofilm (16) is the composition of the biofilm (16) and/or the thickness of the biofilm (16) and/or the volume density of the biofilm (16).
9. Water-conducting domestic appliance having an apparatus (7) according to one of the preceding claims.
10. Water-conducting domestic appliance according to claim 9, characterised in that the domestic appliance is configured as a domestic appliance for the care and/or cleaning of laundry items or dishes, such as a washing machine (1) or dishwasher.
11. Water-conducting domestic appliance according to claim 9, characterised in that the domestic appliance is a beverage preparation machine, which comprises an apparatus according to one of claims 1 to 4 and 6 to 8.
12. Method for assessing a hygiene state of a water-conducting domestic appliance (1), wherein an electric detection facility (10) of the domestic appliance (1) is coupled electrically to at least one part (4) of the domestic appliance (1) conducting or guiding water or an aqueous solution, wherein the part is configured in the form of a hose or container (4), characterised in that a capacitance measurement is performed using the detection facility (10) and the hygiene state of the part (4) is assessed by the detection facility (10) as a function of the capacitance measurement, which means that an assessment, as a function of a measured capacitance, of a property of a biofilm (16) formed on the inner face of the part (4) is performed using the detection facility (10).
13. Method according to claim 12, characterised in that the part (4) is configured as a tub.

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