EP2848729A1 - Laundry dryer - Google Patents

Abstract

The invention relates to a laundry drying device 1, in particular a tumble dryer 1, comprising a rotatably mounted drum 6, in the interior laundry items can be introduced and through the process air in the context of a drying program the laundry process can be passed and subsequently via a lint filter 11 is conductive. In this case, a measuring device 12 is provided for measuring the conductivity of the items of laundry, which comprises electrodes 13, 14 which can be brought into contact with the items of laundry during the drying program for measuring the conductivity. In order to provide a laundry drying device in which a reliable moisture analysis is possible, but at the same time an optimal operation can be realized, the lint filter 11 carries a first electrode 13 of the measuring device 12. The invention further relates to a lint filter 11 for a laundry drying device 1, as well A method of operating a clothes drying apparatus 1.

Description

The invention relates to a laundry drying apparatus, in particular a tumble dryer, comprising a rotatably mounted drum, in the interior of which laundry items can be introduced and through which process air can be conveyed as part of a drying program of the laundry items and subsequently passed through a fluff filter, wherein a measuring device is provided for measuring the conductivity of the laundry items, which comprises electrodes that can be brought into contact with the items of laundry during the drying program for measuring the conductivity. Furthermore, the invention relates to a lint filter for a laundry drying apparatus, and a method for operating a laundry drying apparatus.

Laundry drying devices are used to dry items of laundry, ie a reduction of residual moisture remaining in the laundry items after a previous washing process. In order to be able to effectively design a respective drying program of the laundry drying apparatus, a residual moisture of the laundry items is detected at certain time intervals in the context of the respective drying program in order to determine whether a drying of the laundry is to continue or already sufficient drying has been achieved, so that the drying program can be stopped accordingly. Here, different methods for detecting the residual moisture of the laundry items are used, wherein a common variant is the determination of a conductance of the laundry, which is proportional to the moisture content of the laundry.

From the DE 102 60 149 A1 goes out a laundry dryer in the form of a tumble dryer, which has a rotatably mounted drum, in which laundry items can be introduced for drying. During a selected drying program process air is then passed through the drum and then passed over a lint filter to prevent entrained by the process air fluff on another Mitströmen with the process air. The tumble dryer also has a measuring device, by means of which a conductance of the laundry items can be detected within the scope of a moisture analysis. This measuring device has electrodes which are used during the drying program and in the moisture measurement each can be brought into contact with the laundry items. In this case, the electrodes are combined in a device which protrudes into the region of an interior space of the drum, so that the laundry items accommodated in the drum can come into contact with both electrodes for conductivity measurement. During conductance measurement, a voltage is applied to the two electrodes via a resistor, which results in a current flow through the adjacent laundry items. The laundry voltage dropping on the laundry items is then measured at the electrodes and the conductance is determined therefrom, which is proportional to the respective moisture content of the laundry items.

Starting from the above-described prior art, it is now the object of the present invention to provide a laundry drying apparatus, in which a reliable humidity measurement is possible, but at the same time an optimal operation can be realized.

From a device technical point of view, this object is achieved on the basis of the preamble of the independent claim in conjunction with its characterizing features. A lint filter for an inventive laundry drying device is also apparent from the corresponding independent claims. From a procedural point of view, a solution of the problem is based on the preamble of the corresponding independent claim in conjunction with its characterizing features.

According to the invention, a laundry drying device comprises a rotatably mounted drum, in the interior of which laundry items can be introduced and through which process air can be conveyed as part of a drying program of the laundry items and subsequently be conducted via a lint filter. In addition, a measuring device is provided for measuring the conductivity of the items of laundry, which comprises electrodes which can be brought into contact with the items of laundry as part of the drying program for measuring the conductivity value. In the context of an operation of the laundry drying apparatus, a conductivity measurement of the items of laundry for determining a respective residual moisture is triggered during a drying program by applying a voltage between the two coils of the measuring device.

For the purposes of the invention, the laundry drying apparatus is preferably a tumble dryer, which can then be designed in particular as an exhaust air dryer, condensation dryer or as a heat pump dryer. Alternatively, the laundry drying apparatus may under certain circumstances also be a washer-dryer, in which both a washing of introduced laundry items and their subsequent drying can be displayed.

A Leitwertmessung the garments takes place in the context of the invention in that between the two electrodes of the measuring device via a resistor voltage is applied, which is subsequently determined by measurement on a voltage divider, series resistor to the laundry resistance, the conductance, which is proportional to the residual moisture content the laundry is.

The invention comprises the technical teaching that the lint filter, via which the process air led out of the drum is passed, carries a first electrode of the measuring device. For this purpose, the lint filter in particular comprises a screen housing to which the electrode is attached. In this case, this screen housing preferably has a portafilter which is covered with a fine-meshed screen material and on which a lint filter head is mounted with perforations, the process air pass through these perforations from the interior of the drum into the interior of the lint filter and thus of the screen housing and on the Portafilter can escape through the fine-meshed material again. In this case, corresponding, entrained by the process air lint are deposited on the screen material.

Such an embodiment of a laundry drying apparatus has the advantage that a better contacting between the laundry items and the electrodes of the measuring device for Leitwertmessung is realized because the laundry items are pressed by the process air flowing through the drum in the direction of the lint filter and thereby with the there get in contact electrode. Since contact measurement of at least one item of laundry with both electrodes is necessary for conductance measurement, the probability of such a contact is thereby determined by the appropriate arrangement of the measuring device favors. Furthermore, only a second electrode of the measuring device has to be arranged elsewhere, which offers more space for optimized air guidance, in particular in the area of a bearing plate of the laundry drying device.

On the other hand, a query can be realized by placing one of the electrodes of the measuring device on the lint filter in a simple manner, whether the lint filter is inserted properly. For this purpose, in the context of a method according to the invention for operating a laundry drying device, in the event of the absence of the coil provided by the lint filter, it is detected that conductance measurement of the laundry items introduced can not be carried out, as a result of which the current drying program of the laundry drying device is aborted. Because if there is no lint filter, one of the two coils of the conductivity measurement is accordingly also not present, so that the conductance measurement and thus the moisture measurement can not be carried out during the respective drying program. Since a lack of lint filter leads to a heavy soiling of the airways of the laundry dryer by fluff and these airways, especially in heat pump dryers are difficult to clean, a quick detection of a lint filter failure can improve the life of the laundry dryer and the quality of a drying process.

In contrast, in the case of DE 102 60 149 A1 attached the measuring device for conductivity measurement on a front bearing plate or a part of the holder of the drum. As a result, an appropriate space for accommodating the measuring device in the area of the front bearing plate or the holder of the drum is planned, which may affect the process air flow accordingly. Furthermore, a simultaneous detection of whether a lint filter of the laundry dryer is used, not possible.

According to a preferred embodiment of the invention, a second electrode of the measuring device is attached to a housing part. In a further development of this embodiment, this housing part is a bearing plate, in which the lint filter is inserted in an inserted state into a shaft, via which the process air can be removed from the drum. The placement of the second electrode on the part of a housing part, and in particular on the part of a front bearing plate has the advantage that the second electrode is thus placed spatially very close to the first, sitting on the lint filter electrode, so that at a coming to this area lying down laundry both a contact to the one as well as to the other electrode. Apart from that, the second electrode may, in principle, however, also be provided on the part of the drum, either on the drum body or on a driver, or else on another housing part. In this case, it is only necessary to ensure that the spatial distance to the first electrode of the measuring device does not become too great, so that a piece of laundry which comes into contact with the first electrode also comes into contact with the second electrode at the same time and a conductance measurement is possible as a result.

According to a further advantageous embodiment of the invention, the first electrode is attached to a head of the lint filter. Preferably, the electrode is designed as a sheet metal strip, which is attached to the head of the screen housing of the lint filter. As a result, the first electrode can be easily provided in the region of an inner space of the drum. In particular, the electrode can be encapsulated on the lint filter, clamped or secured by another method.

It is a further embodiment of the invention that the lint filter is provided with an external, electrical contact, which is electrically connected to the first electrode and in an inserted state of the lint filter on a housing-side, electrical contact is applied, so that an electrical supply of the attached to the lint filter electrode is the housing side represented. The screen housing of the lint filter is therefore provided with an external electrical contact, which is electrically connected to the first electrode. As a result, a voltage can be applied to the first electrode for conductance measurement in a simple manner on the housing side. Furthermore, this can also be the query whether the lint filter is inserted properly, can be realized in a reliable manner, as a conductance measurement is not possible if no contact of the housing-side contact with the flusensiebseitigen contact is made. In this way, for example, be detected if the onset of the lint filter while not forgotten, but it was not done properly. Particularly preferably, the fluff filter side contact is designed as a wide metal contact, while the housing-side contact is realized as a resilient metal clip, so that this housing-side clamp presses against the flusensiebseitigen contact and establishes the electrical connection.

In a further development of the invention, in the case of the termination of the drying program, if there is no lint filter, an error message is output. As a result, the respective operator of the clothes dryer is informed that the lint filter is missing and a drying program can not be continued. This error indication can be present in particular as a warning signal in the form of a luminous control lamp, an acoustic signal and / or a reference to a control element.

The invention is not limited to the specified combination of the features of the independent claims or the claims dependent thereon. It also results in ways to combine individual features, even if they emerge from the claims, the following description of a preferred embodiment of the invention or directly from the drawings. The reference of the claims to the drawings by use of reference numerals is not intended to limit the scope of the claims.

Fig. 1

eine schematische Ansicht eines Wäschetrocknungsgeräts;

Fig. 2

eine perspektivische Ansicht eines Lagerschilds des Wäschetrocknungsgeräts aus Fig. 1, mit darin aufgenommenem Flusensieb;

Fig. 3

eine weitere perspektivische Ansicht des Lagerschilds des Wäschetrocknungsgeräts aus Fig. 1, ohne darin platziertem Flusensieb; und

Fig. 4

eine perspektivische Einzelansicht des Flusensiebs des Wäschetrocknungsgeräts aus Fig. 1.

An advantageous embodiment of the invention, which is explained below, is shown in the drawings. It shows:

Fig. 1

a schematic view of a laundry dryer;

Fig. 2

a perspective view of a bearing plate of the laundry dryer Fig. 1 , with lint filter received therein;

Fig. 3

another perspective view of the bearing plate of the laundry dryer from Fig. 1 , without lint filter placed in it; and

Fig. 4

a single perspective view of the lint filter of the laundry dryer Fig. 1 ,

Out Fig. 1 is a schematic view of a laundry dryer 1, it being in this laundry drying device 1 is a clothes dryer 1, which may be designed in particular as exhaust air dryer, as a condensation dryer or as a heat pump dryer with a principle known in the art. The tumble dryer 1 has a machine housing 2, which is provided on a front side 3 with an opening 4, wherein this opening 4 can be closed by a door 5.

In the machine housing 2, a drum 6 is rotatably mounted, which is equipped on one of the front side 3 facing side with a feed opening 7, via which laundry items can be introduced from the front side 3 forth in an interior 8 of the drum 6. For rotatable mounting in the machine housing 2, the drum 6 is mounted on the one hand in the rear region on a drive shaft 9, and on the front side via a bearing plate 10, which is part of the machine housing 2. Furthermore, a rear wall of the drum 6 is provided with a perforation, via which heated process air can be supplied to the interior 8 of the drum 6 and can flow around the laundry located therein. In the process, this process air absorbs moisture from the items of laundry and continues to flow in the direction of the feed opening 7 of the drum 6, the process air laden with moisture then being discharged again in the area of the end shield 10.

Out Fig. 2 and also out Fig. 3 is a partial perspective view of the bearing plate 10 of the tumble dryer 1 to see, in Fig. 2 the bearing plate 10 is shown with a lint filter 11 inserted, while in Fig. 3 is removed. When the lint filter 11 is inserted, a measuring device 12 is configured in the region of the end shield 10, by means of which a guide value of the items of laundry can be determined during a drying program of the items of laundry introduced into the drum 6, thus making it possible to conclude a residual moisture of the items of laundry.

As in Fig. 2 can be seen, the measuring device 12 comprises two electrodes 13 and 14, of which a first electrode 13 on the lint filter 11 and a second electrode 14 is attached to the bearing plate 10. In operation, a residual moisture content of the laundry items is determined by these two electrodes 13 and 14 by applying a voltage to both electrodes 13 and 14 via a controller (not shown) which is applied when the laundry item contacts both electrodes 13 and 14 a current flow through this laundry has the result. The thereby dropping on the laundry laundry voltage is measured in the sequence on the control of the measuring device and determined from this the conductance of each garment. This conductivity in turn is proportional to the residual moisture content in the laundry, so that can be closed accordingly to the residual moisture.

As in Fig. 2 and also in Fig. 3 can be seen, the second electrode 14 is doing on the bearing plate 10 via an in Fig. 2 attached lid 15 is fixed and arranged spatially close to the first electrode 13, which on a head 16 of the in Fig. 4 provided in a single view lint filter 11 is provided. In this case, the first electrode 13 and also the second electrode 14 are placed so that they are in the region of perforations 17 of the head 16 of the lint filter 11, so that items of laundry, which are drawn over the perforations 17 escaping process air in this area, with high probability at the two electrodes 13 and 14 come to rest.

The lint filter 11 is, as in synopsis of Fig. 2 and Fig. 3 can be seen, taken in a corresponding shaft 18 of the bearing plate 10, via which the process air is discharged again after flowing through the interior 8 of the drum 6. In this case, the lint filter 11 is arranged in the shaft 18 in a manner known to the person skilled in the art such that the process air enters the lint filter 11 via the perforations 17 and thus into the interior of the individual view Fig. 4 the lint filter 11 to see sieve housing 19 passes. In addition to the head 16, this screen housing 19 also comprises a portafilter 20, which has a port Fig. 4 not further shown - carries fine-meshed screen material, through which the process air can escape from the screen housing 19 again, being entrained with the process air lint.

A voltage supply of the first electrode 13 of the measuring device 12 is now on the housing side represented by the bearing plate 10 in the region of the shaft 18, a housing-side, electrical contact 21 is provided, which in one of Fig. 2 resulting inserted state of the lint filter 11 with a contact 22 touched. This contact 22 is out on an outer side of the screen housing 19 of the lint filter 11 steals, as in Fig. 4 you can see. Within the screen housing 19, this contact 22 is then in turn connected to the first electrode 13 provided on the head 16. The lint-side contact 22 is designed as a wide metal contact, while the housing-side contact 21 is realized as a resilient metal clip.

Apart from a conductivity measurement is also realized via the measuring device 12, a query whether the lint filter 11 is inserted properly. Thus, during an operation of the tumble dryer 1 in a drying program, moisture is initially measured by the measuring device 12. If the lint filter 11 is not inserted into the shaft 18 or inserted in such a way that the contacts 21 and 22 do not touch, no conductance measurement can take place due to the first electrode 13 either not in place or due to their lack of power supply and thus also not be closed on the residual moisture of the laundry. In this case, the respective drying program is terminated and an error signal is output to the operator, for example in the form of a luminous warning lamp, an acoustic signal and / or a corresponding display on a control element. In this way it is prevented that the drying program without lint filter 11 is completed, which would otherwise have a correspondingly high input of lint into the airways of the clothes dryer 1 result.

By means of the described embodiment of a laundry drying apparatus, on the one hand, the detection of residual moisture of inserted laundry items can be improved and, in addition, a lint filter can be realized in a simple manner.

reference numeral

1

clothes dryer

2

machine housing

3

front

4

opening

5

door

6

drum

7

loading port

8th

inner space

9

drive shaft

10

end shield

11

lint

12

measuring device

13

electrode

14

electrode

15

cover

16

head

17

perforations

18

shaft

19

screen housing

20

Espresso Machines

21

Contact

22

Contact

Claims (10)

Laundry drying apparatus (1), in particular tumble dryer (1), comprising a rotatably mounted drum (6), in the interior (8) laundry items can be introduced and through the process air in a drying program of the laundry pieces can be passed and subsequently via a lint filter (11) can be conducted in which a measuring device (12) is provided for measuring the conductivity of the items of laundry, which comprises electrodes (13, 14) which can be brought into contact with the items of laundry during the drying program for measuring conductivity, characterized in that the lint filter (11) has a first electrode (13) of the measuring device (12) bears. Laundry drying apparatus according to claim 1,
characterized in that a second electrode (14) of the measuring device (12) is fixed to a housing part. Laundry drying apparatus according to claim 2,
characterized in that the housing part is a bearing plate (10), in which the lint filter (11) is inserted in an inserted state into a shaft (18) through which the process air from the drum (6) can be discharged. Laundry drying apparatus according to claim 1,
characterized in that the first electrode (13) is fixed to a head (16) of the lint filter (11). Laundry drying apparatus according to claim 1,
characterized in that the lint filter (11) is provided with an external electrical contact (22) which is electrically connected to the first electrode (13) and in an inserted state of the lint filter (11) on a housing-side electrical contact ( 21) is applied, so that an electrical supply of the first electrode (13) is on the housing side represented. Lint filter (11) for a laundry drying appliance according to one of claims 1 to 5, comprising a sieve housing (19) to which an electrode (13) of a measuring device (12) is attached for the conductivity measurement of laundry items. Lint filter (11) according to claim 6,
characterized in that on the screen housing (19) on the outside an electrical contact (22) is provided, which is in electrical communication with the electrode (13). Lint filter (11) according to claim 6,
characterized in that the electrode (13) is designed as a sheet metal strip which is attached to a head (16) of the screen housing (19). Method for operating a laundry drying apparatus, wherein a Leitwertmessung the laundry items to determine a respective residual moisture is triggered in the context of a drying program, and wherein in the context of Leitwertmessung a voltage between two coils (13, 14) of a measuring device (12) is to create, characterized in that, in the event of the absence of a lint filter (11) having a coil (13) and the conductance measurement which can not be carried out, the drying program is interrupted. Method according to claim 9,
characterized in that in this abort of the drying program an error indication is issued.

Images