EP1956961B2 - Domestic dishwasher having a metering device, and method of metering active substances - Google Patents

Description

The invention relates to a household dishwasher with a housing in which a washing compartment is arranged and with at least one dosing device arranged inside the housing for the program-controlled addition of an active substance into the washing compartment. In addition, the invention relates to a method for dosing cleaning agent and bleach into the washing compartment of a household dishwasher with a housing and with at least one dosing device arranged inside the housing for separate storage and dispensing of the liquid or paste-like cleaning agent and the liquid or paste-like bleaching agent, the dosing device being equipped with storage containers for this purpose, which have a capacity that exceeds the amount of cleaning agent or bleaching agent required for a single washing process and the capacity of the supply tanks are different.

Household dishwashers are generally known ( EP 1 329 187 A2 ), whose dosing systems are suitable for storing a large amount of liquid rinse aid, with a fraction of this amount then being dosed into the wash tub in each wash program. In addition, dosing systems are known ( DE 199 28 040 A1 ), in which liquid aftertreatment agents can also be stored. These dosing systems also have a receiving chamber into which detergent in the form of powder or tablets is filled for each wash cycle and which is then emptied into the wash tub by the program control during the corresponding program step. In the case of these devices, it is considered disadvantageous that the user has to fill the receiving chamber with detergent for each washing program. Another disadvantage is that the dosage of the cleaner is made by the user himself with a rough estimate of the amount actually required (when using powder) or without any possibility of variable dosage (when using tablets).

Storing large quantities of cleaning tablets or powder in the area of influence of the rinsing compartment of a dishwasher has proven to be impractical, since these agents clump together as a result of the effects of moisture and temperature increases and can therefore no longer be dosed automatically, stick to their storage compartments or are impaired in their effectiveness.

Commercially used cleaning and disinfection devices are also known ( DE 196 43 270 A1 ), in which the required amount of active substance is fed from a sales container to the rinsing container of the device by means of a dosing pump. Using sales containers is impractical since they require additional storage space or installation space within the device. In addition, an agent that can be used in household dishwashers and has the same cleaning properties as conventional powders or tablets cannot be stored in a liquid or pasty formulation. The reason for this is the sensitivity of the enzymes required for the breakdown of starch and protein to oxidizing substances, which an effective bleaching system requires. In liquid or pasty media, these opponents can be separated less effectively than in powder or tablet detergents.

From the DE 103 58 969 A1 a dishwasher with a dosing device is known in which larger amounts of so-called basic chemicals can be stored. The bleaching agent required for the rinsing process is produced here in the form of gaseous active chlorine in a microreactor. The use of chlorine gas leads to an unpleasant odor development, and chlorine gas is even poisonous in large quantities.

From the DE 195 11 789 A1 a washing machine or dishwasher with a dosing chamber is known. The dosing chamber has a variable volume.

From the DE 85 02 661 U1 a device for supplying cleaning agents to dishwashers is known, in which two separate storage chambers for cleaning agents are offered. This means that detergent can be added to the pre-rinse and cleaning. The chambers have different intake volumes in a ratio of 1:2.

The EP 0423044 B1 describes a distributor for a liquid product with a reservoir arranged, for example, on the door of a dishwasher.

The U.S. 2002/0088502 discloses a dosing device for dosing a liquid product into a dishwasher with a reservoir.

The WO 03/027377 A1 describes a storage metering device for installation in a washing machine or a dishwasher, which has a plurality of storage containers.

The invention therefore addresses the problem of disclosing a household dishwasher of the type mentioned, which allows for the storage of larger amounts of detergent and thus, if necessary, their automatic dosing with improved handling Domestic dishwasher allowed. According to the invention, this problem is solved by a household dishwasher having the features of claim 1.

The invention also faces the problem of disclosing a method for dosing such a cleaning agent, in which the refilling process is simplified. According to the invention, this problem is solved by a method having the features of claim 10.

Advantageous refinements and developments of the invention result from the subclaims which follow in each case.

The advantages that can be achieved with the invention consist, in addition to a simplification of the operating process, in the fact that the amount of detergent can be automatically adapted to the degree of soiling of the dishes, the degree of filling and/or the washing program selected in each case. In addition, the separate storage of the cleaning and bleaching components offers the advantage that they can be added at different times and in different quantities and can then develop their optimum effect in the respective program section.

In an advantageous embodiment, the reservoirs are arranged in the upper area of an appliance door that closes the washing compartment. This facilitates their filling.

It is also advantageous if the storage containers are thermally insulated from the rinsing container. This prevents the components from being too exposed to the temperature fluctuations in the washing tank, which could impair their effectiveness.

For the simple realization of an automatic, program-controlled dosing, dosing chambers are connected to the reservoir, the transition openings between the reservoir and the dosing chamber being separable from one another by first sealing elements. By opening these sealing elements, a defined amount is admitted into the dosing chambers, which is then emptied through outlet openings in the dosing chambers by opening second sealing elements. It is particularly advantageous if the first and second sealing element are each coupled to one another in such a way that closing a transition opening causes an outlet opening to open and opening a transition opening causes an outlet opening to close. As a result, only one actuator per reservoir is required to move the first and second sealing element. There is even the possibility of coupling the sealing elements of both reservoirs to one another and thereby saving a further actuator. However, this has the disadvantage that metering of the two components that is independent of time or quantity has to be dispensed with.

The sealing elements can expediently be moved by an electric motor or electromagnetically.

When using a device for generating at least one liquid jet in the dishwasher, it is also advantageous if the second sealing elements are arranged in the impingement area of the liquid jet. This achieves cleaning of the sealing elements and thus ensures their tight fit.

In a particularly advantageous embodiment, the capacity of a metering chamber is a fraction of the maximum amount of active ingredient metered in a washing program. As a result, a variable amount of active substance, adapted for example to the degree of soiling of the dishes, the degree of filling and/or the respectively selected washing program, can be supplied to the washing process by actuating the dosing device several times.

It is also advantageous if the storage containers have different capacities. In this way, account can be taken of the fact that less bleach than cleaning agent is required in a rinsing process. The method for dosing cleaning agent and bleaching agent according to claim 11 is used here in an advantageous manner. The fact that the cleaning agent and the bleach are dosed in amounts within a washing program, the ratio of which corresponds to the ratio of the capacity of the reservoirs, ensures that both reservoirs are always empty at the same time and can therefore be refilled in a single step.

Figur 1

die Schemaskizze der Frontseite einer erfindungsgemäß aufgebauten Haushaltsgeschirrspülmaschine;

Figur 2

einen Querschnitt durch den oberen Bereich der Gerätetür der Haushaltsgeschirrspülmaschine nach Figur 1;

Figuren 3a, b

die Dosiereinrichtung für Reinigungs- und Bleichmittel als Einzelheit während der Befüllung der Dosierkammern (Figur 3a) und während der Entleerung der Dosierkammern (Figur 3b).

An embodiment of the invention is shown purely schematically in the drawings and is described in more detail below. It shows

figure 1

the schematic sketch of the front of a household dishwasher constructed according to the invention;

figure 2

a cross section through the upper area of the appliance door of the household dishwasher figure 1 ;

Figures 3a, b

the dosing device for cleaning and bleaching agents as a detail during the filling of the dosing chambers ( Figure 3a ) and during the emptying of the dosing chambers ( Figure 3b ).

In figure 1 the front side of a household dishwasher 1 is shown. In a known manner, this has a washing container 2 which is open towards the front and can therefore be closed by a pivoting appliance door 3 . The figure shows the machine with the door 3 closed, which is why the in figure 2 indicated flush tank 2 in figure 1 not is visible. The upper area of the door 3 can carry a control panel 4, in which there are rotary selector switches 5 and/or pushbuttons 6 for selecting a program and also display devices 7 for displaying user information. The device control 8 and other electrical and electronic components are arranged inside the control panel, which is symbolized by the dashed box. Door 3 is as in figure 2 recognizable, formed from an outer door panel 9 and an inner door panel 10 . The inner door panel 10 is provided with a beveled edge 11 so that a closed hollow body 12 is formed by joining the outer panel 9 and inner panel 10 . The dosing devices or reservoirs described below are arranged in this hollow body 12 and are therefore indicated by dashed structures; the valves, hose connections, electrical lines or similar that are also required. are not the subject of the invention and are therefore not shown here. In the middle door area there is a known way (see e.g. EP 1 329 187 A2 ) A so-called combi-dosing device 13, which is suitable for receiving powdered or tablet-shaped detergent for one wash cycle and for receiving rinse aid for several wash cycles. In addition, a salt container can be provided, which accommodates the regeneration salt required for regenerating a softening device. According to the invention, a further dosing device 15 is arranged in the upper left half of the appliance door 3 .

The other dosing device 15 is for the program-controlled dispensing of liquid or pasty cleaning agent 16 and liquid or pasty bleaching agent 17 (see Fig. Figure 3a and b ) suitable. The active ingredient components are stored separately from one another in two different containers 18 and 19 . Thus, the components enzyme/alkalinity and bleaching agent that are incompatible with one another in liquid and/or pasty formulations are only mixed in the washing container and can develop their full effect there.

In the exemplary embodiment shown, the further dosing device is provided as a supplement to the combination dosing device 13, so that the user can choose between conventional powder or tablet cleaning agents and liquid components. A less convenient embodiment can dispense with the combination dosing device 13, in which case the dosing device 15 must then be expanded to include a chamber for rinse aid (not shown).

The dosing device 15 consists, as in figure 3 can be seen from the two reservoirs 18 and 19 with molded dosing chambers 20 and 21, each of which is associated with a closure device 22 and 23 respectively. It can be manufactured as a one-piece plastic component, in which case a common housing 24 is divided into the two containers 18 and 19 by means of a partition 25 . Alternatively, a separate construction of both containers 18 and 19 is possible. The dosing device 15 is in the cavity 12 between the outer panel 9 and the inner panel 10 deployed. The reservoirs 18 and 19 are surrounded by a thermal insulation layer 26 at least on the side facing the washing compartment 2 . Alternatively, all container walls can be made of a heat insulating material (not shown). The outlet openings 27 and 28 for dosing the media 16 and 17 are designed as channels 29 (see Fig. figure 2 ), which penetrate the inner door panel 10 approximately at the level of the access flaps 30 to 32 of the salt container 14 and the combination dosing device 13. The filling openings are also designed as channels 33 and protrude through the folded edge 11 of the inner door panel 10, so that the containers 18 and 19 can be easily filled when the appliance door 3 is slightly open. A mechanism not shown in the drawings can ensure that the door is held in this slightly open position, so that the user has both hands free for filling.

The closure means consist of pushers 34 and 35 connecting respectively rods 36 and 37 of electromagnets 38 and 39 between a first, in Figure 3a shown position and a second, in Figure 3b shown position are movable. The upper ends 34.1 and 35.1 of the tappets 34 and 35 are rounded and thus form upper sealing surfaces through which the transition openings 40 and 41 between the storage containers 18 and 19 and the metering chambers 20 and 21 can be closed, as in Figure 3b shown. The lower ends 34.2 and 35.2 are also rounded and form lower sealing surfaces with which the inlets of the channels 29 and thus the outlet openings 27 and 28 to the washing container 2 can be closed, see FIG Figure 3a . Outside of the dosing process, the plunger 34 remains lowered and closes the outlet opening 27 with its lower sealing surface 34.2. As a result, the reservoir 18 is open to the dosing chamber 20 and the dosing chamber 20 is consequently filled. To carry out a dosing process, the plunger 34 is then raised so that the upper sealing surface 34.1 closes the transition opening 40 and prevents the medium 16 from running into the dosing chamber 27. At the same time, this removes the lower sealing surface 34.2 from the channel inlet and releases the outlet opening 27. The supply of cleaning agent 16 in the dosing chamber 20 is thus emptied into the washing container 2 . The dosing of bleach 17 from the reservoir 19 by means of the closure device 23 is analogous.

The outlet openings 27 and 28 should be placed so that they are hit by a spray jet through one of the spray arms (e.g. the middle one, not shown), which gives the possibility that the spray jets can clean the sealing seat between outlet and metering chamber 20 or 21. The spray jets can even partially wash out the dosing chamber 20 or 21 .

In the Figures 3a and b It can be seen that the right reservoir 19 for bleach 17 and the right dosing chamber 21 have a smaller volume than their left neighbors. The reason for this is the fact that smaller amounts of bleaching agent 17 than cleaning agent 16 are needed for a rinse cycle. If dosing chambers 20 and 21 and reservoirs 18 and 19 are dimensioned in such a way that the ratio of the two reservoirs 18 and 19 corresponds exactly to the ratio of the dosing chambers 20 and 21 and if the same number of dosing processes for detergent 16 and bleach 17 is also carried out in each wash program, this ensures that both containers 18 and 19 are empty at the same time.

The metering chambers 20 and 21 are also dimensioned in such a way that their capacity is only a fraction of the maximum amount of active substance metered in a washing program. In this way, such a fraction can be dosed several times in the course of a washing program. On the one hand, there is then the possibility of varying the metered amount of cleaning agent, either as a function of the program set and/or as a function of parameters of the items to be washed and/or the washing liquid determined by sensors. The detergent consumption can thus be optimized depending on the load, the level of dirt or the program, for example by measuring the turbidity of the suds using a corresponding turbidity sensor (not shown). On the other hand, the subsets can be supplied to the washing container at different time intervals of the washing program. In order to counteract the aging-related reduction in the cleaning or bleaching power of the agents 16 and 17 used, higher dosages can also be used as the level in the reservoirs 18 and 19 decreases. For this purpose, at least one level sensor (not shown in the drawings) or a device for detecting that the container is empty or that the container is full is required, with the latter also having to count the number of meterings that have already taken place.

If the (highly) concentrated individual components of the cleaning or bleaching agent come into contact with the user's skin, allergic reactions can be triggered. In order to avoid this, no medium must escape when filling the reservoir. This can be achieved in that, for example, the refill container is opened by a corresponding counterpart on the storage container in such a way that the closure is only unlocked when it is correctly positioned (not shown). The well-known principle of quick-release fasteners in compressed air systems could be used for this purpose.

• großer freier Querschnitt der Übergangs- und Auslassöffnungen 40, 41, 27 und 28;
• ausreichend großer Hub der Stößel 34 und 35;
• Versehen der Stößel 34 und 35 mit Rippen auf der Oberfläche, die insbesondere spiralförmig ausgebildet sein können, dadurch wird das zu dosierende Medium 16 bzw. 17 in Bewegung versetzt (nicht dargestellt);
• Drehen der Stößel 34 und 35 während der Hubbewegung um ihre Hubachse;
• schräge Ausbildung der Dichtebenen der Dichtelemente 34.1, 34.2, 35.1 und 35.2, so dass sich Luftblasen gezielt an einer definierten Stelle sammeln können.

Since the enzyme/alkali and/or bleach components have different viscosities, which can vary from thin to honey-like, the dosing mechanism must be able to ensure safe inflow and outflow from the dosing chamber 20 or 21 at all viscosities to ensure. This can be achieved by the following measures, used individually or in combination:

• large free cross section of the transition and outlet openings 40, 41, 27 and 28;
• sufficiently large stroke of the plunger 34 and 35;
• Providing the tappets 34 and 35 with ribs on the surface, which can in particular be spiral-shaped, as a result of which the medium 16 or 17 to be metered is set in motion (not shown);
• Rotating the rams 34 and 35 about their stroke axis during the stroke movement;
• oblique formation of the sealing planes of the sealing elements 34.1, 34.2, 35.1 and 35.2, so that air bubbles can collect in a targeted manner at a defined point.

Claims (11)

1. Domestic dishwasher (1) comprising a housing in which a washing container (2) is arranged, and comprising at least one metering device (13; 15), which is arranged within the housing, for adding an active substance to the washing container in a program-controlled manner,

   the metering device (15) being configured to separately store and dispense a liquid and/or pasty cleaning agent (16) and a liquid and/or pasty bleaching agent (17), the metering device (15) being equipped for this purpose with storage containers (18, 19) which have a capacity that goes beyond the amount of cleaning agent (16) or bleaching agent (17) required for a single washing procedure,

   characterised in that

   the metering device (15) is equipped with integrally formed metering chambers (20, 21), the capacity of the storage containers (18, 19) being different, and the metering chambers (20, 21) and the storage containers (18, 19) being dimensioned in such a way that the ratio of the capacity of the storage containers (18, 19) corresponds to the ratio of the volume of the metering chambers (20, 21).
2. Domestic dishwasher (1) according to claim 1,
   characterised in that
   the storage containers (18, 19) are arranged in the upper region of an appliance door (3) which closes the washing container (2).
3. Domestic dishwasher (1) according to at least one of the preceding claims,
   characterised in that
   the storage containers (18, 19) are thermally insulated with respect to the washing container (2).
4. Domestic dishwasher (1) according to at least one of the preceding claims,
   characterised in that
   metering chambers (20, 21) adjoin the storage containers (18, 19), the transition openings (40, 41) between storage containers (18, 19) and metering chambers (20, 21) each being separable from one another by first sealing elements (34.1, 35.1).
5. Domestic dishwasher (1) according to claim 4,
   characterised in that
   the metering chambers (20, 21) have outlet openings (27, 28) pointing towards the washing container (2) which can each be closed by a second sealing element (34.2, 35.2).
6. Domestic dishwasher (1) according to claims 4 and 5,
   characterised in that
   the first (34.1, 35.1) and second (34.2, 35.2) sealing elements are coupled to one another in such a way that closing a transition opening (40, 41) causes an outlet opening (27, 28) to be opened and opening a transition opening (40, 41) causes an outlet opening (27, 28) to be closed.
7. Domestic dishwasher (1) according to at least one of claims 4 to 6,
   characterised in that
   the sealing elements (34, 35) can be moved by means of an electric motor or electromagnetically.
8. Domestic dishwasher (1) according to at least one of claims 4 to 7, comprising a device for generating at least one liquid jet,
   characterised in that
   the second sealing elements (34.2, 35.2) and/or the metering chambers (20, 21) are arranged in the impingement region of the liquid jet.
9. Domestic dishwasher (1) according to at least one of claims 4 to 8, characterised in that
   the capacity of a metering chamber (20, 21) is a fraction of a maximum amount of active substance added in a washing program.
10. Method for metering a cleaning agent (16) and a bleaching agent (17) into the washing container (2) of a domestic dishwasher (1) comprising a housing and comprising at least one metering device (20, 21), which is arranged within the housing, for separately storing and dispensing the liquid and/or pasty cleaning agent (16) and the liquid and/or pasty bleaching agent (17),
    characterised in that

    the metering device (15) is equipped for this purpose with storage containers (18, 19) which have a capacity that goes beyond the amount of cleaning agent (16) or bleaching agent (17) required for a single washing procedure and the capacities of the storage containers (18, 19) are different,

    and that the metering device (15) is equipped with integrally formed metering chambers (20, 21), the metering chambers (20, 21) and the storage containers (18, 19) being dimensioned in such a way that the ratio of the capacity of the storage containers (18, 19) corresponds to the ratio of the volume of the metering chambers (20, 21),

    the cleaning agent (16) and the bleaching agent (17) being dispensed in a washing program in amounts of which the ratio corresponds to the ratio of the capacity of the storage containers (18, 19).
11. Metering method according to claim 10,
    characterised in that
    the cleaning agent (16) and/or the bleaching agent (17) are dispensed in an amount which is dependent on the set program and/or on parameters of the washware which are determined by a sensor and/or on the washing fluid.

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