DE4410589C2 - Method for controlling the program of a washing machine - Google Patents

Description

The invention relates to a method for controlling a washing machine with water level- and level-controlled water supply, at which the start of a wash programs, preferably in a main wash program in at least one part a first program section until a target level is reached first partial flow of water is detected by direct or indirect measurement and is used as a basis for the calculation of further partial water volumes, and in which Depending on the first amount of water, one for the entire washing program required total amount of water is determined.

Such a method for controlling a washing machine with water level and level-controlled water supply is known from DE-OS 39 09 021. Although there the total water volume is not explicitly the sum of the partial water volumes and thus is formed as a numerical value, however, this is implicit in the control by Calculation of the individual summands of this sum available. So it will be there too first the first part of the water used for the main wash cycle, which from the first partial water volume, the following partial water volumes are then calculated for the following rinses or wash cycles are determined and distributed to them in a defined manner. In order to is also the difference between the total amount of water and the first Partial water volume Existing residual water volume as the further partial water volumes has been distributed to the following program sections, although there is not an explicit one there Difference was calculated mathematically. The type of assignment of the Total water volume for the first partial water volume is not disclosed there.

In the aforementioned method, it has proven to be disadvantageous that one of adjusts the absorbency and the load quantity dependent water consumption, the limits of which are determined only by the drum or tub volume are. In addition, the consumption data of such a washing program show a lot large scatter due to the working behavior (hysteresis) of the pressure switch result.

The invention thus presents the problem of a method of the type mentioned at the beginning To create a way to control the program of a washing machine, in which the  Consumption tolerances and, as a result, overall consumption are reduced will.

According to the invention, this problem is solved with those specified in claim 1 Features resolved. Appropriate further developments and refinements result from the following subclaims.

The achievable with the inventive design of the subject matter The advantage is that a defined target amount of water consumption is specified and so the water consumption of a washing machine can be reduced.

A particularly advantageous embodiment of the method according to the invention is characterized in that the increase in the area of low water consumption in first program section is higher than in the area of high water consumption.

Because the area of average water consumption is statistically most common occurring loading case, d. H. with almost fully used loading capacity and medium suction behavior of the load occurs, in this area the water supply need kept constant, which further reduces the consumption values. Only in rarely occurring cases, namely an underloading or a loading with very high suction behavior, the amount of water required is varied.

An embodiment of the invention is shown purely schematically in the drawings represents and is explained in more detail below. Show it:

Figure 1 is a schematic representation of a washing machine for performing the method according to the invention.

Fig. 2 is a diagram of the further partial water quantities and the total water consumption depending on the first partial water quantity in the main wash.

The washing machine drum ( 1 ) is rotatably mounted in a known manner in the tub ( 2 ). As a water level controller, a conventional level switch ( 3 ) is provided, which is connected in terms of circuitry to the central control unit of the program control device ( 4 ).

The fresh water is fed in via a feed line ( 5 ) in which there is a solenoid valve ( 6 ) which receives control commands for opening from the program control device ( 4 ). Solenoid valves ( 6 ) with a small volume flow tolerance range are preferably used over the largest possible pressure range. The water supply is shown in simplified form in the drawing, so that only the inflow via the detergent dispenser drawer ( 7 ) is symbolized.

In the first part of the program, generally in the main wash (HW), the water flow is level-controlled. The water enters the tub ( 2 ) until a set level N is reached, after which a moistening phase begins, in which the laundry absorbs water. If the switch-back level N _R falls below the target level N, water is re-introduced until the target level N is reached. This refueling process can be repeated. The total amount of water that flows in is directly dependent on the amount of laundry and the absorbency of the laundry and is therefore not constant. To save water, refueling is no longer permitted when a predetermined temperature value T setpoint has _been reached.

The computer of the program control measures the switch-on times of the solenoid valve ( 6 ) during the main wash (HW) and adds them up to a first switch-on time _t1 . At constant pressure conditions, this is proportional to the amount of water that has entered. Depending on the resulting first on-time _t1 of the main wash (HW) from a memory of the program control device (4) is at the end of a total ON time t _ges accessed. From this total switch-on t _tot is subtracted t₁ and the remaining difference t _{d is distributed} to the other program sections.

The program sequence is structured in such a way that the main wash (HW) is followed by a lye cooling (LA) followed by a rinse with two or three rinse cycles (SP1, SP2, SP3). The assignment of the additional partial water quantities in the individual program sections, which results from the respective switch-on times of the solenoid valve ( 6 ), is shown in FIG. 2 as a function of the first partial water quantity in the main wash (HW). In addition, the dependence of the total water quantity on the first partial water quantity is shown in FIG. 2. For this purpose, the first partial water quantity is entered on the abscissa and the other water quantities on the ordinate.

A constant second portion flows in during the alkali cooling (LA). With a consumption of up to approx. 9 liters in the main wash (HW), a third portion, proportional to the first, is distributed over two rinse cycles (SP1, SP2). In the range from 9 to 13 liters, the third portion, which is proportional to the first, is distributed over three rinse cycles (SP1, SP2, SP3). This results in a total amount M _total proportional to the first partial amount in this area with low water consumption in the main wash (HW). Efficient rinsing is thus ensured in this area of low loading, which is mostly used by single households.

With a consumption in the range of 13 to 17 liters in the main wash (HW), a third partial quantity, which is inversely proportional to the first partial quantity, is distributed over three rinse cycles (SP1, SP2, SP3). This third subset is in each case dimensioned such that a constant total amount M _{tot is} established in this area of average water consumption in the main wash (HW).

In the area of high water consumption in the main wash (HW) from 17 liters, the third part is again distributed proportionally to the first part over three rinse cycles (SP1, SP2, SP3). Here, the proportionality factor, however, is kept lower than in the range of 9 13 liters in the main wash (HW), so that the increase in the total quantity of water M _ges depending on the first Teilwas sermenge low on water consumption in the main wash (HW) is higher than in Area of high water consumption.

In order to achieve safety and emergency running properties, the rinse cycles (SP1, SP2, SP3) are also monitored for levels. If level N is not reached in one of the rinse cycles (SP1, SP2, SP3), the solenoid valve ( 6 ) remains open until this level is reached. Such a case can e.g. B. occur with strong pressure fluctuations or when the calculated value for the required valve switch-on time is no longer available due to a power failure. In the case of a level-controlled monitoring of the rinse cycles (SP1, SP2, SP3), the refueling used in the main wash is suppressed when the switch-back level N _{R is} undershot if the water intake to level N is reached within a set time t _s . In this case, the laundry has soaked up very little water and therefore only a very small amount of rinse water, so no refueling is required. The suppression of the refueling process prevents a greater water consumption when the lower pressure switch N _{R is switched} on due to strong water movements.

Claims (7)

1.Method for controlling a washing machine with water supply controlled by water level and level, in which at the beginning of a washing program, preferably in a main washing program, at least part of a first program section receives a first partial water quantity which has flowed in until a desired level is reached, by direct or indirect measurement and is used as a basis for the calculation of further partial water quantities, and in which, depending on the first partial water quantity, a total water quantity required for the entire washing program is determined, characterized in that the residual water quantity consisting of the difference between the total water quantity and the first partial water quantity follows as the further partial water quantities Program sections is distributed, the assignment of the total amount of water to the first partial amount of water takes place in such a way that

• - In an area of low water consumption in the first program section, the total amount of water increases proportionally to the first partial water
• - A constant total amount of water is supplied in an area of medium water consumption in the first program section.
• - In an area of high water consumption in the first program section, the total amount of water increases proportionally to the first partial amount of water.

2. A method for controlling a washing machine according to claim 1, characterized, that the increase in the total amount of water depending on the first part amount of water in the area of low water consumption in the first program section higher than in the area of high water consumption in the first program section. 3. A method for controlling a washing machine according to one of the claims 1 or 2, whereby one of the program sections consists of a rinse with at least there is a rinse cycle, characterized, that the number of rinse cycles depends on the first partial water volume is determined.   4. A method of controlling a washing machine according to one of claims 1 to 3, characterized in that after reaching a defined temperature state of the incoming partial water quantity at the beginning of the program, refueling when the switch-back level (N _R ) is undershot is prevented during this program section. 5. A method for controlling a washing machine according to one of the claims 1 to 4, characterized, that additional monitoring of the water level is carried out in the rinse cycles. 6. A method for controlling a washing machine according to claim 5, characterized in that in the wash cycles when a reference level (N) is reached in a target time (t _s ) refueling when the switch-back level (N _R ) is undershot is overridden. 7. A method for controlling a washing machine according to one of the claims 1 to 6, characterized, that the measurement or calculation of the water quantities indirectly by measurement or Valve switch-on times are calculated.