EP2579760A1 - Method for controlling a dosing appliance for a flowable detergent or washing agent - Google Patents

Abstract

The invention relates to a method for controlling a dosing appliance (5) of a stand-alone dosing system for a flowable detergent or washing agent, preferably for using in a dishwasher machine. Said dosing system (4) consists of a dosing appliance (5) and a container for at least one washing agent, that is embodied as a cartridge (11). Said dosing appliance (5) comprises a housing (6), at least one energy source (7) arranged inside the housing, at least one actuator (16) for carrying out the dosing, and an electronic control unit (8) for controlling at least the actuator (16). A conductivity sensor (8) connected to the control unit (8) in a circuit and open to the surroundings of the dosing appliance (5) is arranged on the housing (6). The method for such a dosing appliance (5) is carried out in such a way that, during the running of a washing cycle comprising at least two different rinsing stages (S1, S2), the conductivity measuring value (L) respectively instantaneously determined by the conductivity sensor (18) is continuously or discontinuously assessed by the control unit (8); the sequence of determined conductivity measuring values (L) is evaluated by the control unit (8) in terms of the course of the absolute value of the conductivity (L) and in terms of the gradient of the course (dL/dt) of the conductivity; and then, if the instantaneously measured conductivity measuring value (L) exceeds a maximum conductivity measuring value (Lmax) determined in the first rinsing phase (S1), and the gradient of the course (dL/dt) of the conductivity measuring value exceeds a certain threshold value (D), this is evaluated by the control unit (8) as being a water renewal and beginning of the next rinsing stage (S2).

Description

 Method for controlling a dosing device for

 flowable detergents or cleaners

The invention relates to a method for controlling a dosing of a self-sufficient

Dosing system for flowable detergents or cleaners, preferably for use in a dishwasher with the features of the preamble of claim 1.

The invention also relates to a dosing device with which this method can be carried out.

One of the major goals of the machine cleanser manufacturers is to improve the cleaning performance of these agents, with a recent focus on cleaning performance in low temperature or reduced water consumption cleaning cycles. For this purpose, the cleaning agents were preferably added to new ingredients, for example, more effective surfactants, polymers, enzymes or bleach. However, since new ingredients are available only to a limited extent and the amount of ingredients used for each cleaning cycle can not be increased to any extent for ecological and economic reasons, this approach has natural limits.

In this context, in particular devices for the

Multiple dosing of detergents and cleaners in the field of view of

Advised product developers. In these devices can between in the

Dishwasher or Textilwaschmasch ine integrated metering chambers on the one hand and stand-alone, independent of the dishwasher or textile washing machine devices on the other hand be distinguished. By means of these devices, which are several times necessary for carrying out a cleaning process

Detergent amount contain detergent or detergent portions are dosed in an automatic or semi-automatic manner in the course of several successive cleaning process in the interior of the cleaning machine. For the

 Consumers eliminate the need for manual dosing with each cleaning or washing cycle.

The starting point for the teaching of the present invention is a metering system according to WO 2010/006761 A2. The following statements relate primarily to the example of a dishwasher, because the method according to the invention and the metering device according to the invention can also be used particularly expediently in a dishwashing machine. However, the statements are generally to be understood that they also apply to other devices in which pose similar problems, in particular

 Textile washing machines, which also work with several rinses within a cleaning cycle.

In the known method, from which the invention proceeds (WO 2010/006761 A2), the metering unit of the metering system initially has a sensor which is intended and suitable for detecting the water temperature in the dishwasher.

The control of the process of the process is largely on the determined

Water temperature. In particular, the beginning of the rinse cycle of the

Dishwasher detected by the fact that there is a higher water temperature than the normal cleaning rinse or intermediate rinse.

In addition to a temperature sensor, the metering device of the known metering system has a sensor for detecting the conductivity, which is open to the environment of the metering device, in other words, is accessible to the water that is in the dishwasher. In the known dosing device, the conductivity sensor at the bottom of the dosing device on two open towards the environment contacts, which are preferably designed as protruding down from the ground contact pins. One contact is connected as an anode contact, the other contact is connected as a cathode contact with respect to the energy source. These contacts may each be covered with an electrically conductive silicone to less easily corrode. The spacing of the contacts is typically between 2 and 25 mm.

By means of the control unit, the track resistance of the distance between the two contacts can be determined, which are in the conductivity of the contacts wetting

Medium, in particular the cleaning liquid in the dishwasher, can convert. If there is no liquid bridge between the contacts, the conductivity is very low, it is close to zero. If there is water in the dishwasher, ie if there is a rinse cycle, then the conductivity sensor which is open to the environment in the dishwasher is subjected to cleaning liquid, and a cleaning liquid is produced

Liquid bridge between the contacts, the conductivity has become much higher. In the above-described prior art, it is only determined by means of the control unit with the aid of the conductivity sensor whether water is present in the dishwasher or whether it is dry. The actual control of the dosing over the course of rinses - cleaning rinse, intermediate rinse, rinse - away, however, takes place by the control unit based on the measurement signals of the temperature sensor.

The teaching is now based on the problem, the control of the dosing

more practical and sensitive. The aforementioned problem is solved in a method having the features of the preamble of claim 1 by the features of the characterizing part of claim 1.

The essential idea of the method according to the invention is the course of the

Method of the rinses of the cleaning cycle, - cleaning rinse,

Intermediate rinse or intermediate rinses, rinse cycle - not or at least not only by means of the temperature sensor to control, but also or primarily the

Conductivity sensor and its conductivity readings to use.

It should be repeated again that the representation of the invention takes place here with reference to the preferred example of a dishwasher. The application to others

However, facilities with similar issues, in particular a textile washing machine, are expressly implied.

The teaching of the invention is based on the fundamental knowledge that the electrical conductivity in the cleaning fluid of the concentration of the electrolyte in the

Cleaning fluid depends. As the electrolyte concentration increases, the conductivity increases. The electrolyte concentration increases when detergent enters the water

is added and / or if the dirt dissolves slowly in the cleaning liquid. The conductivity reaches its maximum during the Reinigungsspülganges as soon as the detergent is completely dosed into it and dissolved and also the entire dirt has detached and passed into the cleaning liquid.

In the course of the further rinsing process, the conductivity changes only slightly by increasing or decreasing the temperature of the cleaning liquid or by

Dilution processes when, for example, fresh water is added. Only when at least a partial change of water, the conductivity changes significantly. This situation is exploited according to the invention in order to control the course of the process. A significant change in conductivity usually means a change from one rinse to the next rinse. In particular, this initially applies to the transition from the first, the Reinigungsspülgang, in the second, the intermediate rinse cycle.

According to the invention, the course of the conductivity over time during the

Abiaufens the rinsing determined by the control unit by means of the conductivity sensor. In addition, the gradient of the course of the ability to measure readiness is evaluated. A change from rinse cycle to rinse cycle is only detected if not only the maximum conductivity value determined in the first rinse cycle is exceeded, but only if, in addition, the conductivity drops at a certain minimum speed, ie a certain gradient.

The second criterion provides a high certainty that the change in the

Conductivity actually takes place due to a complete water change and not only due to the addition of smaller amounts of fresh water. With the method according to the invention, the control of the self-sufficient metering system is independent of which temperature boundary conditions at the expiration of the

Dishwasher available. This takes into account the fact that modern dishwashing products manage with lower temperatures than formerly usual. The temperature curves over a dishwashing cycle are therefore no longer always to the extent clearly attributable to the different types of rinses. The same applies to modern detergents, rinse aids and fabric softeners for textile washing machines.

Of particular importance is the doctrine of the invention as to where in the rinse cycle no renewed heating of the cleaning liquid. Particularly affected are those dishwashers in which no more heat energy has to be supplied for the drying following the rinse cycle. There, the dehumidification is usually done rather by adsorption or absorption. The hitherto typical high temperature in the rinse cycle can not be detected here, the temperature sensor is not helpful in this respect. For particular, the determination of the rinse cycle apply the other versions of the dependent claims, the claims 2 to 6 in particular. Further preferred embodiments and further developments of the method according to the invention are then the subject matter of claims 7 and 8. According to claim 9, the inventive method is executed with the program control of a program-controlled electronic control unit or causes the corresponding method steps.

In a dosing device according to the invention, the control unit is thus programmed in such a way that, during operation in a dishwasher, it is capable of exerting the previously explained method steps.

In the following, the invention will now be described with reference to an only preferred

Exemplary embodiments illustrative drawing explained in more detail. In the drawing shows

Fig. 1 is a schematic view of a large appliance, shown here as

 Dishwasher, with a dispensing system according to the invention arranged in a drawer,

2 shows the metering system from FIG. 1 once with the cartridge detached from the metering device and secondly with the cartridge coupled to the metering device, FIG.

3 shows a concrete embodiment of a metering system according to the invention with the cartridge still dissolved by the metering device,

4 is a flowchart of a dishwashing cycle based on the course of the

 Conductivity readings in the cleaning fluid.

Fig. 1 shows first a large household appliance, here in the form of a dishwasher 1 with an interior, which is accessible in this illustration because of the front door 2 folded down to the outside. In the interior there is a drawer 3, shown as a dish rack, in which a metering system 4 is according to the invention. It can be seen that the metering system 4 can in principle be positioned anywhere within the drawer 3 of the dishwasher 1. It is advantageous to have a similar to a plate shaped metering system 4, so that it can be set in a corresponding plate receptacle of the drawer 3.

In Fig. 1, a dosing chamber is indicated on the front door 2 of the dishwasher 1, in which a detergent tablet or the like. can be entered. But is that the case? Dosing system 4 according to the invention inside the dishwasher 1, a use of the metering chamber is not required because the delivery of the washing or

Detergent is implemented in the interior of the dishwasher by the metering system 4.

The basic principle of the dosing system 4 can be found in FIG. 2.

In Fig. 2 in the housing 6 is indicated by dashed lines on the right an energy source 7, typically a battery or a rechargeable battery, and left next to an electronic control unit 8, typically equipped with a microprocessor or a microcontroller and conventional further components of such a control unit. At the front of the

Housing 6 are indicated display and / or controls 9, which indicate the operating state of the dosing device 5 and / or can act on this.

At the top of the housing 6 of the dosing device 5 you can see a, designed here as a peripheral edge connecting portion 10 for releasably coupling a above the dosing device 5 shown cartridge 1 first This cartridge 1 1 is thus shown here solved by the metering device 5. The cartridge 1 1 has at least one cartridge chamber 12. In the illustrated and preferred embodiment, the cartridge 1 1 has two cartridge chambers 12, so that two different flowable washing or

Cleaning agents can be stored.

WO 2010/006761 A2 explains very comprehensively what these washing or cleaning agents typically are and what the compositions are. Also in this respect may be made to the state of the art.

At the bottom of the cartridge 1 1 can be found at the two cartridge chambers 12 each outlet 13 of the cartridge chambers 12th

To the outlet openings 13 of the cartridge chambers 12 of the cartridge 1 1 Dosierkammereinlässe 14 correspond to the top of the housing 6 of the dosing device 5. The Dosierkammereinlässe 14 further comprise means which open upon insertion / coupling of the cartridge 1 1 to the housing 6 of the dosing device 5 cause the outlet 13, so that in the coupled state of the cartridge 1 1 and metering device 5, the interior of the cartridge chambers 12 communicating with the Dosierkammereinlässen 14 is connected. Fig. 2 shows the situation on the right, which is present when the cartridge 1 1 is coupled to the dosing device 5. Here the dosing system 4 is complete and ready for use. 3 shows more detailed details of the various cartridge chambers 12 of the cartridge 11, the outlet openings 13 and the metering chamber inlets 14. In particular, FIG. 3 shows in the metering device 5 below the metering chamber inlets 14 the dosing chambers 15 with associated actuators 16 and closure elements 17. All this is described in detail in WO 2010/006761 A2 and requires no further details here

Explanation.

In Fig. 3 can be seen in the left half of the housing 6 of the metering device 5, the control unit 8 with the power source 7, all shown schematically.

In Fig. 3 can be seen at the bottom of the housing 6 of the dosing device 5 indicated a conductivity sensor 18. In this conductivity sensor 18 are outwardly guided contacts, which are wrapped according to preferred teaching of the invention with an electrically conductive silicone to protect against corrosion to be. Towards the inside, these contacts are connected in terms of circuitry to the energy source 7 and the control unit 8, so that the corresponding conductivity measurement can be carried out via the contacts of the conductivity sensor 18 in the cleaning liquid in the dishwasher.

The basic construction of the conductivity measurement in the metering device 5 according to the invention is known from the prior art described above and requires no further explanation here. Rather, reference may be made in this respect to WO 2010/006761 A2.

This is about the process by which the dosing device of the dosing system 4 is controlled during use in a dishwasher during a rinsing cycle. This control is performed by the control unit 8.

According to the method according to the invention, it is provided that, during the execution of a cleaning cycle, in this case a dishwashing cycle, with at least two different rinses S _2, S _2, the conductivity measurement sensor L determines continuously or discontinuously from the control unit 8 the conductivity value currently determined by the conductivity sensor 18 is that of the control unit 8, the sequence of measured keitligkeit- measured values L with respect to the course of the absolute value of the conductivity and with respect the gradient of the curve dL / dt of the conductivity is evaluated and that when the currently measured readability measurement value L falls below a maximum conductivity measured value L _max determined in the first rinse ST and the gradient of the profile dL / dt of the conductivity Measured values exceeds a certain limit value D, which is evaluated by the control unit 8 as a water change and the beginning of the next wash cycle S ₂ .

The typical course of the conductivity L in the cleaning liquid in one

Dishwasher during a dishwashing cycle, Fig. 4.

At the beginning, no water has yet flowed into the interior of the dishwasher 1, the conductivity sensor 18 is dry, and the conductivity reading is as good as zero. This is because the track resistance between the contacts of the conductivity sensor 18 is extremely high, it is practically only an air gap.

Now fresh water flows into the interior of the dishwasher 1. The dishwasher dishwashing arms begin to rotate, and the conductivity sensor 18 begins to rotate

Cleaning fluid, which is still essentially clean water, is applied. The conductivity increases abruptly to the typical conductivity for fresh water.

The control unit 8 has therefore first determined by means of the conductivity sensor that the dishwasher is now in operation. Therefore, a time measurement function of

Run control unit 8, so that the time can be adjusted, at which the first detergent must be dosed into the cleaning liquid. In parallel, it is determined by the temperature sensor, not mentioned here, whether the cleaning liquid in the dishwasher 1 has already reached the correct temperature for optimum cleaning by means of the first cleaning agent. When the first cleaning agent is metered into the cleaning liquid - point R -, this leads to an abruptly increasing electrolyte concentration. The conductivity, which is measured via the conductivity sensor 18, increases abruptly. It can be seen in Fig. 4 at this point very well. During the further cleaning cycle, dirt dissolves, the

Temperature conditions change slightly, the conductivity readings (L) change slightly. This can be seen from the relatively uniform, flat course of the curve of the conductivity measured values (L) in FIG. 4.

At the end of the cleaning cycle, the dirty cleaning liquid is pumped out. The measured conductivity value L, which is determined via the conductivity sensor, drops, decreases with a gradient dL / dt, which is considerably larger than a previously defined one

Limit D. This is evaluated by the control unit 8 as the end of the Reinigungsspülgangs. The dosing device 5 "knows" now that it enters the next rinse S ₂ , the intermediate rinse cycle.

In Fig. 4 can be seen right at the end of the last rinse cycle S ₃ , the rinse cycle, now that the rinsing agent with rinsed cleaning liquid finally from the

Dishwasher 1 has been pumped. The conductivity sensor 18 is dry again, the conductivity keits- measured value L has dropped to virtually zero. The metering device 5 recognizes after a certain time, which is to be defined over a predetermined time window, that the entire dishwashing cycle has now been completed.

According to the invention, it is further provided in accordance with a preferred teaching that when the second control unit 8 starts the second wash cycle S ₂ again determines that the gradient of the curve dL / dt of the conductivity (L) the limit value D or another, for the second Rinse S ₂ stored limit exceeds D ', this of the

Control unit 8 is evaluated as a water change and the beginning of the next wash cycle S ₃ . Since in the intermediate rinse cycle, even if one should again add a cleaning agent, in all likelihood will not set conductivity readings L which is as high as in the cleaning rinse cycle, one will possibly also work with a different limit value D 'for the gradient, to determine the next change to the third rinse.

In some cleaning cycles, there is not only an intermediate rinse, but several intermediate rinses. For another intermediate rinse from the last rinse, the

Rinse, to distinguish, can be considered in the context of the method according to the invention further criteria.

In the rinse cycle, it is necessary to trigger the dosage of a further cleaning agent, in this case the drying and rinse aid. According to a further preferred teaching applies to this particular situation that a minimum conductivity keits- measured value L _{min is} predetermined in the control unit 8 or determined and stored by the control unit 8 and that it is from the control unit 8 as the beginning of the last rinse S ₃ , the

Rinse cycle, only then evaluated, if in addition also the minimum

Conductivity value L _{min is} undershot. A first possibility for determining a suitable minimum conductivity measured value L _min is to determine and store it at the beginning of the cleaning cycle, ie with clear fresh water in the dishwasher. Another possibility is to determine and store the minimum conductivity measured value L _min when changing from the first wash cycle S _T to the second wash cycle S ₂ . The latter has the advantage of usually even lower error rate of the control process.

So has the control unit 8 of the dosing device 5 found that there is a

Was given cleaning rinse and now the intermediate rinse is completed, so the dosing device 5, regardless of the temperature in the cleaning liquid or in the interior of the dishwasher 1, the dosing of rinse and / or

Trigger drying agent. In this case, the minimum conductivity measured value L _min in the control unit 8 can be predefined from the outset or can result from the minimum conductivity measured value determined during the transition from the cleaning rinse cycle to the intermediate rinse cycle and stored by the control unit 8. Which of the variants one chooses will depend on the practical test.

To be sure that now really the last, the rinse cycle has begun, it may be advisable to introduce yet another criterion, namely to provide that it is evaluated by the control unit 8 as the beginning of the last wash cycle S ₃ , the rinse cycle, only then is, if the minimum conductivity reading L _min below and within a predetermined time window after _falling below the minimum

Conductivity measured value L _{min is} again exceeded by the current conductivity measured value (L). This prevents you from prematurely or intentionally ending the

Dishwashing cycle accidentally from the metering 5 the rinse and / or

Desiccant is metered.

In principle, it is possible to determine the conductivity measured values L in different ways with the conductivity sensor 18. The determination of the conductivity readings L is preferably carried out by the control unit 8 by means of a discrete, discontinuous measurement at the conductivity sensor 18. Experience has shown that it is expedient if at least 100, preferably at least 200, conductivity measurements or resistance measurements per second be made by the control unit 8 by means of the conductivity sensor 18. In order to avoid polarization effects, it is also recommended that after each

Conductivity measurement or any particular number of conductivity measurements on the conductivity sensor 18 is a polarity reversal.

The above explanations have already made it clear that one has to assume in the first place of a program-controlled electronic control unit 8, which corresponds to today's state of modern development and will regularly include a microprocessor or microcontroller. Of course, the control unit 8 also has corresponding other modules, in particular electronic data storage.

According to the invention, it is therefore recommended that it is a program-controlled electronic control unit 8 and that the method steps are executed or initiated by the program of the control unit 8.

As has already been stated above, the subject of the invention is also a dosing device 5 as such, whose control unit 8 is programmed so that the method steps described above can be carried out.

Claims

claims Method for controlling a dosing device (5) of a self-sufficient dosing system for flowable detergents or cleaning agents, preferably for use in a dishwasher,  wherein the metering system (4) consists of the metering device (5) and a storage container for at least one washing or cleaning agent, in particular designed as a cartridge (1 1) detachably coupled to the metering device (5),  wherein the dosing device (5) has a housing (6) in the housing (6) at least one  Energy source (7), at least one actuator (16) for carrying out a dosage and an electronic control unit (8) for controlling at least the actuator (16) and the housing (6) connected to the control unit (8) circuitry, to the environment of the dosing device (5) has an open conductivity sensor (18), characterized that during the execution of a cleaning cycle with at least two different rinses (S ^ S ₂ ) of the control unit (8) of the  Conductivity sensor (18) each currently determined Le ility keits- measured value (L) is determined continuously or discontinuously,  in that the control unit (8) evaluates the sequence of determined conductivity readings (L) with regard to the course of the absolute value of the conductivity (L) and with respect to the gradient of the curve (dL / dt) of the conductivity, and if the currently measured conductivity reading (L) falls below a maximum conductivity reading (L _max ) determined in the first wash cycle (S 1) and the gradient of the course (dL / dt) of the conductivity readings falls below a certain limit ( D), this is evaluated by the control unit (8) as a water change and the beginning of the next rinse cycle (S ₂ ). Method according to claim 1, characterized in that in that, after the start of a second rinse cycle (S ₂ ), the control unit (8) again ascertains that the gradient of the curve (dL / dt) of the conductivity exceeds the limit value (D) or another, for the second rinse cycle (S ₂ ) stored limit value (D '), this is evaluated by the control unit (8) as a water change and the beginning of the next rinse cycle (S ₃ ). 3. The method according to claim 2, characterized that a minimum conductivity keits- measured value (L _min ) in the control unit (8) given or determined by the control unit (8) and stored and that it from the control unit (8) as the beginning of the last rinse cycle (S ₃ ), the Rinse cycle, is only evaluated if in addition the minimum conductivity value (L _min ) is exceeded. Method according to claim 3, characterized the minimum conductivity measured value (L _min ) is determined and stored by the control unit (8) at the beginning of the first wash cycle (S 1) of the cleaning cycle. Method according to claim 3, characterized that the minimum conductivity measured value (L _min ) is determined and stored by the control unit (8) when changing from the first rinse cycle (S 1 to the second rinse cycle (S ₂ ) of the cleaning cycle. Method according to one of claims 3 to 5, characterized that it from the control unit (8) as the beginning of the last rinse cycle (S ₃ ), the Rinse cycle, is only evaluated if the minimum conductivity reading (L _min ) falls below and within a predetermined time window after the Fall below the minimum conductivity reading (L _min ) from the current one  Conductivity reading (L) is exceeded again. Method according to one of the preceding claims, characterized in that per second at least 100, preferably at least 200 conductivity measurements or resistance measurements by the control unit (8) by means of the conductivity sensor (18) are made. Method according to one of the preceding claims, characterized in that after each conductivity measurement or any particular number of  Conductivity measurements on the conductivity sensor (18) a polarity reversal takes place. Method according to one of the preceding claims, characterized in that it is a program-controlled electronic control unit (8) and the method steps are executed or initiated by the program of the control unit (8). 10. Dosing device for a self-sufficient dosing system (4) for flowable washing or Cleaning agent, preferably for use in a dishwasher, with a housing (6), in the housing (6) at least one energy source (7), at least one actuator (16) for performing a dosage, an electronic control unit (8) for controlling at least the actuator (16) and the housing one with the Control unit (8) connected in terms of circuitry, to the environment of the dosing device (5) open towards conductivity sensor (18), characterized, in that the control unit (8) of the dosing device (5) is programmed in such a way that during operation of the dosing device (5) it carries out or causes the method steps of a method according to one of claims 1 to 9.