Household appliance and a controlling method for such a household appliance

Abstract

A household appliance includes a circulation pump for circulating dishwashing liquid in a washing compartment of the household appliance. A drain pump empties the dishwashing liquid from the washing compartment. For the purposes of ventilating the drain pump, a control device is provided to activate the drain pump after the washing compartment has been filled with the dishwashing liquid and before or during operation of the circulation pump.

Claims

1. A household appliance, comprising: a washing compartment; a circulation pump for circulating dishwashing liquid in the washing compartment; a drain pump for emptying dishwashing liquid from the washing compartment; and a control device configured to activate the circulation pump and drain pump in program steps of a wash cycle and to ventilate the drain pump in each program step after the washing compartment has been filled with dishwashing liquid and before operation of the circulation pump.

2. The household appliance of claim 1, constructed in the form of a dishwasher.

3. The household appliance of claim 1, wherein the control device is configured to activate the drain pump for ventilation thereof for a defined length of time of between 2 and 5 seconds.

4. The household appliance of claim 1, wherein the control device is configured to activate the drain pump for ventilation thereof for a defined length of time of between 2.5 and 3.5 seconds.

5. The household appliance of claim 1, wherein the control device is configured to activate the drain pump for ventilation thereof for a defined length of time of 3 seconds.

6. The household appliance of claim 1, wherein the control device is configured to set a length of time for activating the drain pump for ventilation thereof on the basis of a predefined conveying characteristic of the drain pump.

7. The household appliance of claim 1, wherein the control device is configured to activate the drain pump for ventilation thereof after each filling of the washing compartment with the dishwashing liquid and before or during operation of the circulation pump.

8. The household appliance of claim 1, wherein the control device is configured to activate the drain pump for ventilation thereof between filling of the washing compartment with the dishwashing liquid and activation of the circulation pump.

9. The household appliance of claim 1, wherein the control device is configured to activate the drain pump for ventilation thereof in such a way that dishwashing liquid is pumped out of the washing compartment after the washing compartment has been filled with dishwashing liquid and before or during operation of the circulation pump.

10. The household appliance of claim 1, wherein the control device is configured to activate the drain pump for ventilation thereof after the washing compartment has been filled with dishwashing liquid and before or during operation of the circulation pump.

11. The household appliance of claim 1, wherein the control device is configured to control the drain pump and the circulation pump.

12. The household appliance of claim 1, wherein the control device is configured as controller of the household appliance.

13. A household appliance, comprising: a washing compartment; a circulation pump for circulating dishwashing liquid in the washing compartment; a drain pump for emptying dishwashing liquid from the washing compartment; and a control device configured to activate the circulation pump and drain pump and to ventilate the drain pump during a wash cycle before a change of liquid that takes place after an execution of an individual program stage as well as before the start of a next individual program stage that follows the individual program stage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other advantageous embodiments or aspects of the invention are the subject of the subclaims and of the exemplary embodiments of the invention described below. The invention is also described in more detail below using preferred embodiments and with reference to the attached figures, in which:

(2) FIG. 1 shows a schematic view of a first exemplary embodiment of a dishwasher;

(3) FIG. 2 shows an execution diagram of a first exemplary embodiment of a method of controlling a dishwasher;

(4) FIG. 3 shows an execution diagram of a second exemplary embodiment of a method of controlling a dishwasher, and

(5) FIG. 4 shows a schematic view of a second exemplary embodiment of a dishwasher.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE PRESENT INVENTION

(6) In the figures, reference signs that are the same denote the same or similar components unless otherwise indicated.

(7) FIG. 1 represents a schematic view of a first exemplary embodiment of a dishwasher 10.

(8) The dishwasher 10 has a circulation pump 13 and a drain pump 19. The circulation pump 13 can be used to circulate dishwashing liquid in the washing compartment 1 (see FIG. 4) of the dishwasher 10. The drain pump 19 can be used to empty the dishwashing liquid from the washing compartment 1. For the purposes of ventilating the drain pump 19, the controlling means 23 is configured to activate the drain pump 19 after the washing compartment 1 has been filled with the dishwashing liquid 1 and before or during operation of the circulation pump 13. This means that the controlling means 23 controls the drain pump 19 in such a way that it is ventilated; it is activated after the washing compartment 1 has been filled and before or during activation of the circulation pump 13.

(9) To this end, the controlling means 23 controls the drain pump 19 by means of a first control signal S1 and the circulation pump 13 by means of a second control signal S2.

(10) For the purposes of ventilating the drain pump 19, the controlling means 23 activates it for a defined length of time of between 2 and 5 seconds. Specifically, this length of time is between 2.5 and 3 seconds. The length of time can be determined by the controlling means 23 on the basis of the drain pump 19 used, and particularly on the basis of the conveying characteristic of the drain pump 19.

(11) In addition, the drain pump 19 is ventilated through being activated by the controlling means 23 after each filling of the washing compartment 1 with dishwashing liquid. For example, the controlling means 23 can also activate the drain pump 19 in such a way that, for the purposes of ventilating the drain pump 19, dishwashing liquid is pumped out of the washing compartment 1 after the washing compartment 1 has been filled with the dishwashing liquid and before or during operation of the circulation pump 13. For example, if, at the stage when the washing compartment 1 is being filled with dishwashing liquid, more dishwashing liquid is introduced than is necessary for the washing process, then, for the purposes of ventilation, a smaller amount of the dishwashing liquid can be pumped out. For example, at the filling stage, four liters of dishwashing liquid are introduced when the quantity of dishwashing liquid required is three liters and one liter is pumped out again at the ventilation stage.

(12) Alternatively, or in addition, ventilation of the drain pump 19 can be triggered by the controlling means 23 during operation of the circulation pump 13.

(13) The controlling means 23 can also be implemented as part of the controller of the household appliance.

(14) FIG. 2 is an execution diagram of a first exemplary embodiment of a method of controlling a dishwasher 10.

(15) In step 201, a dishwasher 10 is provided that has at least one circulation pump 13 for circulating dishwashing liquid in the washing compartment 1 of the dishwasher 10 and a drain pump 19 for emptying dishwashing liquid from the washing compartment 1 (see FIGS. 1 and 4).

(16) In step 202, for the purposes of ventilating the drain pump 19, the latter is activated after the washing compartment 1 has been filled with dishwashing liquid and before or during operation of the circulation pump 13.

(17) FIG. 3 is an execution diagram of a second exemplary embodiment of a method of controlling dishwasher 10.

(18) In step 301, the soiled dishwashing liquid remaining in the washing compartment 1 is pumped out.

(19) In step 302, washing compartment 1 is filled with fresh dishwashing liquid.

(20) In step 303, the drain pump 19 is activated in such a way that it is ventilated.

(21) In step 304, the circulation pump 13 is activated in order that the dishwashing liquid circulates in the washing compartment 1 for the purpose of washing the items introduced into the dishwasher to be washed. After the wash cycle has ended, and thus after the circulation pump 13 has been deactivated, the process starts again with process step 301. It is therefore preferable for steps 301, 302, 303 and 304 to be executed cyclically.

(22) FIG. 4 is a schematic view of a second exemplary embodiment of a dishwasher 10.

(23) The dishwasher 10 has a washing compartment 1 in which items to be washed (not shown) can be arranged in baskets 3, 5. In the washing compartment 1 shown, for example, two spray arms 7, 9 arranged at different spraying levels are provided as examples of sprayers with which dishwashing liquid is applied to the items to be washed. In the floor of the washing compartment is a pump well 11 with a corresponding circulation pump 13 that connects the flow of dishwashing liquid to the spray arms 7, 9 via liquid lines 14, 15, 16.

(24) In addition, the pump well 11 is connected to a fresh water inlet pipe 17 that is connected to the external water supply, as well as to an outlet pipe 18, to which the drain pump 19 for pumping out soiled dishwashing liquid from the washing compartment 1 is connected. Also, a non-return valve 27 is fitted downstream from the discharge pump 19. Downstream from the non-return valve 27 is a siphon section 29 in the waste pipe, with converging vertical sections of pipe, so that a liquid column of a predefined height creates liquid pressure in the reverse-biased direction to the non-return valve 27.

(25) A filter system for cleaning the dishwashing liquid that circulates within the hydraulic circuit is provided in the pump well 11. The filter system has a two-dimensional, funnel shaped fine mesh filter 21 that sits on the upper side of the pump well 11 and a hollow, cylindrical, well-shaped coarse meshed filter 22 that sits in the middle of the pump well 11.

(26) During a wash cycle of the dishwasher 10 the operation of the pumps 13, 19 and of other appliance components not shown here is controlled by the controlling means 23. A wash cycle can have individual program stages in which liquid may or may not be used, such as Pre-rinse, Wash, Intermediate Rinse, Rinse and Dry.

(27) Between two successive program stages in which liquid is used, for example between Pre-rinse and Wash, the dishwashing liquid is changed. When the dishwashing liquid is changed the soiled dishwashing liquid that is no longer needed is drained from the washing compartment 1 into the external drainage network by activation of the drain pump 19. In addition to this, fresh water is fed into the pump well via the fresh water inlet pipe.

(28) The drain pump 19 can be activated during the wash cycle before a change of liquid that takes place after the execution of an individual program stage, such a Pre-rinse, and before the start of the program stage that follows it, for example Wash. A gas bubble trapped in the pump chamber could increase the length of time before the drain pump 19 operates at maximum efficiency. The gas bubble is therefore displaced from the pump chamber by means of the ventilation process described with reference to FIGS. 1 to 3. The ventilation of the drain pump 19 takes place directly after the washing compartment 1 is filled with dishwashing liquid and before activation of the circulation pump 13.

(29) Although the present invention has been described using exemplary embodiments, it can be modified in many ways.