WASHING MACHINE AND METHOD FOR OPERATING A WASHING MACHINE

Abstract

A washing machine has a drum-receiving container and a rotatable drum therein and a water routing system which has a water inlet from an external water supply into the washing machine, water lines and valves, as well as a water outlet from the washing machine. An injection device for water into the drum, a container outlet at the bottom of the drum-receiving container, a pump, a filter and a washing machine controller are provided. The water routing system drive has an adjustable pressure-reducing device arranged between, on the one hand, the water inlet into the washing machine and, on the other hand, the pump and/or the injection device. The pressure-reducing device is connected, for adjustment, to the washing machine controller.

Claims

1. A washing machine having: a drum for washing laundry therein, a drum-receiving container with said drum being rotatably arranged therein, a water routing system having: a water inlet from an external water supply into said washing machine, water lines and valves, a water outlet from said washing machine, an injection device for water into said drum, a container outlet at a bottom of said drum-receiving container, a pump being connected by way of water lines, on the one hand, to said container outlet and, on the other hand, to said injection device, a filter for filtering water flowing through said filter, a washing machine controller, wherein said pump is connected to said washing machine controller, wherein: said water routing system has an adjustable pressure-reducing device, said pressure-reducing device is arranged between, on the one hand, said water inlet into said washing machine and, on the other hand, said pump or said injection device, said pressure-reducing device is connected, for adjustment, to said washing machine controller.

2. The washing machine as claimed in claim 1, wherein said pressure-reducing device is arranged between said water inlet into said washing machine and further regions of said water routing system and upstream of said filter and upstream of said pump.

3. The washing machine as claimed in claim 2, wherein said water inlet is routed to said filter and only one of said water lines is arranged between said pressure-reducing device and said filter, wherein said water line is without any valve.

4. The washing machine as claimed in claim 1, wherein said water routing system has at least one pressure sensor in said drum-receiving container in a lower region of said drum-receiving container at or close to said container outlet.

5. The washing machine as claimed in claim 1, wherein said water routing system has a flow sensor at said water inlet into said washing machine.

6. The washing machine as claimed in claim 1, wherein said filter is arranged in one said water line between said container outlet and said pump.

7. The washing machine as claimed in claim 1, wherein said filter has a filter inlet, a filter outlet and a backflush inlet, wherein said pressure-reducing device is directly connected to said backflush inlet by way of one of said water lines without any valve.

8. The washing machine as claimed in claim 7, wherein a valve is arranged between said container outlet and said filter or said filter inlet.

9. The washing machine as claimed in claim 7, wherein a first three-way valve is arranged downstream of said filter outlet and in one of said water lines from said filter outlet to said pump, wherein one connection of said first three-way valve is routed to said injection device by way of said water lines.

10. The washing machine as claimed in claim 9, wherein a further, second three-way valve is arranged downstream of said connection of said first three-way valve to said injection device, wherein one connection of said second three-way valve is routed to said injection device and another connection of said second three-way valve is routed to said pump.

11. The washing machine as claimed in claim 10, wherein a further, third three-way valve is arranged downstream of said other connection of said second three-way valve to said injection device, wherein one connection of said third three-way valve is routed to said water outlet from said washing machine and another connection of said third three-way valve is routed to said injection device.

12. The washing machine as claimed in claim 1, wherein said washing machine has a dispensing device for apportioning laundry detergents or other substances for laundry treatment in said washing machine, wherein said dispensing device is arranged in said water line upstream of said pump.

13. The washing machine as claimed in claim 12, wherein the dispensing device is arranged in said water line between said filter and said pump at a distance of less than cm from said pump.

14. The washing machine as claimed in claim 1, wherein said washing machine has a heating means for said water in said water routing system, wherein said heating means is separate from said pump and arranged at a distance of between 5 cm and 30 cm from said pump.

15. The washing machine as claimed in claim 1, wherein said pressure-reducing device is arranged in an independently handleable module within a lower region of said washing machine and is configured to be movable as a movable module.

16. The washing machine as claimed in claim 15, wherein water lines, a pump, a valve and a filter are arranged in said movable module.

17. A method for operating said washing machine as claimed in claim 1, wherein a defined water pressure, which is between 1.5 bar and 4 bar, is set at a beginning of an operation of said washing machine by way of said pressure-reducing device in order, in accordance with a preset program, to feed water at said water pressure into said washing machine from said external water supply, in a further method step, said filter is backflushed, for which purpose a water pressure of at least 5 bar is set by way of said pressure-reducing device, in a further method step for a washing process with repeated introduction of water into said drum by way of said injection device, a water pressure of between 2 bar and 3 bar is set by way of said pressure-reducing device.

18. The method as claimed in claim 17, wherein, for backflushing said filter, said water pressure is varied by at least 50%.

19. The method as claimed in claim 18, wherein said water pressure is varied by at least 50% at least every 0.5 sec to 10 sec in such manner that said water pressure is varied in abrupt or pulsed manner.

20. The method as claimed in claim 17, wherein, in an event that said drum has previously been emptied by way of said pump, said water pressure while said drum is being filled with said water is increased by way of said pressure-reducing device up to a maximum pressure of a connecting line to said water inlet.

21. The method as claimed in claim 17, wherein, when said pump is empty and prior to starting operation of said pump, water is admitted into said pump or into said pump chamber thereof at a water pressure being above said water pressure for a washing process.

22. The method as claimed in claim 21, wherein, for this purpose, said water pressure of at least 5 bar is set by way of said pressure-reducing device, wherein to said end said water pressure in said water routing system or of said water admitted into said washing machine at said water inlet into said washing machine is not reduced or decreased by way of said pressure-reducing device.

23. The method as claimed in claim 21, wherein the following steps are provided: within at most 5 sec of setting said water pressure, a valve at said water inlet is opened, a valve between said filter and said container outlet is opened or is already open, and a valve between said filter and said pump is closed or is in a closed state, said filter is vented into said drum-receiving container or through said container outlet, said valve between said filter and said pump is then opened, then, said pump is vented through said opened valves and said water lines into said drum or into said drum-receiving container and filled with water through said filter, water is recirculated by said pump in a circuit through said pump without said water reaching said drum-receiving container or said drum, wherein said water is here heated by way of a heating means past which said water flows, once a desired temperature has been reached by said water, said heated water is then introduced into said drum or into said drum-receiving container through said opened valves and said water lines.

24. The method as claimed in claim 23, wherein said valve at said water inlet is opened simultaneously with setting said water pressure.

25. The method as claimed in claim 17, wherein, for emptying said washing machine, a valve between said container outlet and said filter is closed, wherein fresh water is introduced into said drum via a water line and a valve in order to rinse said drum, wherein a valve downstream of said pump is then closed, such that one of said water lines from said valve to a further valve, which further valve is arranged between said filter and said pump, is open and is rinsed, wherein, once said water line has been rinsed, said valve downstream of said pump is set such that said water can be pumped by said pump via one of said water lines and a further valve to said water outlet out of said washing machine.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Further advantages and aspects of the invention are revealed by the claims and the description of exemplary embodiments of the invention, which are explained below with reference to the FIGURE.

[0033] FIG. 1 is a diagram of a washing machine with an internal structure and a water routing system with lines as well as a pressure reducer.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0034] FIG. 1 shows a washing machine 11 with a housing 12 in which is arranged a drum-receiving container 14 with a drum (not shown) in which laundry is washed. At the bottom of the drum-receiving container 14 with a container outlet to a water line l9 there is a valve V4, downstream of which there is a filter 20. Upstream of the filter 20, a water line l7 goes to a three-way valve V3, one of the outlets of which goes to a dispensing means 22 and then to a pump 24. The outlet of the latter is provided with a heater 27 by way of a water line l5 and leads to a further three-way valve V5, one of the outlets of which goes by way of a water line 14 back to the three-way valve V3. In this way, a circuit as described above can be formed, in which the pump 24 can circulate water in the circuit or loop, preferably in order to slowly heat it to a desired temperature by way of the heater 27.

[0035] Upstream of the valve V5, a water line l2 goes to a three-way valve V2, the right-hand outlet of which forms a water outlet WA from the washing machine 11. Its left-hand outlet leads by way of a water line l1 to an injection device 16 for water into the drum-receiving container 14 or into the drum.

[0036] A water inlet into the washing machine 11 is provided by an external connecting line, advantageously as a flexible hose, from a supply line in the building, as is known from the prior art. A screw connection, frequently with a water-stop device, is conventionally provided at the water inlet. A flow sensor 31 is here provided, with which it can be detected how much water has been admitted from the valve V1 at the water inlet WE into the washing machine 11 or into its water routing system. A water line l6 leads to the filter 20 or to a backflush inlet of the filter 20. In this way, a maximally high water pressure for backflushing can be applied directly to the filter 20. An adjustable pressure reducer 29 according to the invention is arranged in this water line l6. The pressure reducer 29 is controlled by a controller 25 which is connected to all the influenceable or controllable functional units of the washing machine 11; a connection to the pump 24 and to the heater 27 is shown here. Advantageously, the controller 25 is also connected to the valves, the pressure sensor 18, the dispensing means 22 and the flow sensor 31 for the control thereof.

[0037] The pressure reducer 29 is set as previously explained, for example a pressure of 2 bar for the normal washing process. This enables protection of the appliance and a defined pressure in the washing machine 11 irrespective of a water pressure predetermined in the building. The operation or adjustment thereof, in particular setting or allowing the passage of a maximally high water pressure, advantageously for backflushing the filter 20, proceeds as previously described. This is readily conceivable on the basis of FIG. 1. Impurities rinsed out during backflushing can be removed from the washing machine 11 via valve V3, water line l4, valve V5 together with water line l2 and valve V2 to water outlet WA.

[0038] On starting operation of the washing machine 11, the valve V1 is opened and a defined pressure, for example 2 bar, set via the pressure reducer. In this way, the washing machine 11 can be protected and a defined pressure prevails in the system irrespective of the building installation. The pressure reducer 29 can be controlled by the controller 25.

[0039] Valve V4 is open to ensure venting on start-up. Valve V3 is closed in the direction of pump 24. Line 19 permits venting of filter 20 and line l9 via the drum-receiving container 14. The water rises up to the inlet of line l9 on the drum-receiving container 14.

[0040] During subsequent start-up, the pump 24 is filled with water through line l7, once valves V3, V5 and V2 are open. Air can be forced via line l5 into the drum-receiving container 14. Due to the volume in filter 20 and in l9, sufficient water is present to fill or flood pump 24 and lines 14 and 15. V3 and V5 are then set such that a circuit around pump 24 with lines 15 and 14 and through valves V3 and V5 is obtained. Pump 24 can be switched on and the water begins to circulate. The heater 27 can here be switched on without danger since dry running with the risk of excessive heating is no longer possible.

[0041] Once the desired temperature has been reached, valve V5 can be opened and water routed into the drum-receiving container 14. In this way, a defined volume at an appropriate temperature can be introduced via the injection device 16 into the drum or into the drum-receiving container 14. The described process can be performed repeatedly until the laundry in the drum is wetted or drenched to a desired extent.

[0042] Depending on the volume of laundry loaded into drum, the process is performed repeatedly until it can be ensured that backflow from the drum-receiving container 14 is possible because water absorption by the laundry has reached saturation. This can be detected by way of sensors or by way of empirical values. Operation can be changed over to continuous recirculation. A desired temperature in the drum or on the laundry can be set since the manner in which the washing machine is constructed as well as the ambient temperature etc. are known, such that temperature control in the circuit can be adjusted by the pump 24 and lines 15 and 14 in accordance with the particular cycle.

[0043] Instead of discontinuous operation, continuous operation can also be used for wetting the laundry. Valve V1 is accordingly opened such that water can continue to flow until the laundry is wetted and backflow from the drum is identified or the calculated water volume (based on load volume, type of textile, etc.) is reached. Precise temperature control on the laundry as in discontinuous operation is conceivable, but significantly more difficult to control. V4 is closed in this case so that no water reaches the drum-receiving container 14 via the filter 20. When valve V1 is opened, a defined pressure, for example 2 bar, can be set via pressure reducer 29, such that the volume is known as determined by the calculation.

[0044] At the beginning of washing, valve V1 at water inlet WE is left open for as long as is necessary, based on the structural embodiment, to allow the appropriate volume of water to be provided. Operation may here be discontinuous or continuous as previously described. Since the laundry is located in the drum, it absorbs water until the pressure sensor 18 which is located on the drum-receiving container 14 responds. Alternatively, the necessary volume can be determined via the measured volume of water and the weight of the laundry. Depending on the type of textile, account must be taken of a different absorption capacity, which is why the pressure sensor for can also be used for corresponding switching off.

[0045] In the described embodiment, the laundry can also be drenched from below, which in essence corresponds to current washing processes (scoop-and-ladle rib system), where the water flows into the tub and thus the drum from above via the detergent drawer. Since the filter can easily be cleaned after each washing process, the laundry is not soiled.

[0046] If the recirculation method is preferred in order to provide as little water as possible, the drum rotates and the water is applied to the laundry in the drum via the injection device 16. In order to prevent switching off here and thus an excessive volume of water in the process, water reflux can likewise be identified via the pressure sensor 18 or, for optimization, via an additional turbidity sensor in line l7 (not shown in FIG. 1). The function of the turbidity sensor is to monitor the filter 20. The change from air to water can additionally be identified with a turbidity sensor. Alternatively, a conductivity measurement can be provided in parallel which, in addition to process parameters, can also identify water backflow. Water backflow can also be identified via temperature monitoring.

[0047] A further solution is to use a pump which is controlled by an inverter and can identify air in the pump via its current characteristic. This solution is, however, not possible for simple pumps. As soon as a sufficient volume is available for the washing process, the washing process can be continued with the appropriate dispensing.

[0048] If water is pumped out during the washing process, this is achieved via valve V2. Lines 17 and 15 are not completely emptied here, since a time limitation is possible via feedback from the pressure sensor 18 and, optionally, the turbidity sensor. Given appropriate feedback from the two sensors, fresh water can be continuously supplied until a stable state is obtained. Filling with fresh water after intermediate spinning is possible in a similar manner to start-up. The position of valve V4 is the same here.

[0049] The washing machine 11 can be emptied at the end of the washing process via pump 24 as complete emptying of the system, so enabling a reduction in microbial contamination therein. If cleaning is also to be carried out, this can be done once the washing machine 11 has been emptied. Valve V4 is closed such that the drum is isolated from the water routing system. Via V2, fresh water for rinsing, possibly preceded by cleaning agent, can be introduced via the dispensing means 22. V5 is here closed such that line l4 is open. Once line l4 has been rinsed, V5 is set such that line l2 conveys the water out via V2. The pump 24 is here continuously rinsed. In addition to being flushed, the filter 20 and pump 24 can also be flooded with water and appropriate cleaning agents for a certain exposure time, which improves the cleaning action.