EP0962577B1 - Method for filling water in a program controlled washing machine - Google Patents

Description

The invention relates to an improvement in the washing result in washing machines with washing drum rotating in a tub by optimization the free liquor available in the tub for rinsing, according to the procedure specified in the main claim.

According to DE 39 09 021 A1, the amounts of water required for the respective washing program sections depending on the amount of laundry and Type of laundry and regardless of the influence of different pressure conditions in the Line network can be set by means of the program control device, that the computer of the program control device in a first program part measures the different switch-on times of the solenoid valve and adds them up until the The water level in the tub has reached a level switch. The value of this The sum is stored in a memory of the program control device and multiplied by a factor of a value table by the valve switch-on time for the following program section, for example for a rinse cycle determine. For example, the system adapts at the end of the washing process the existing conditions with regard to laundry filling and their suction behavior, and the entire one thereafter intended for the following rinse cycle The amount of fresh water gets into the tub right at the beginning of the wash cycle fed. However, it was not recognized in that prior publication that this Approach for practical needs is not sufficient because the compact laundry filling of the drum which is stationary during the measuring process noticeably lower absorbency than the loosened laundry filling in the Rinsing revolving drum. The result of this is that before insertion Free fleet made available for the rinse cycle at the start of the drum rotation partially soaked up in the then loosened laundry filling and therefore no longer the optimal volume for the actual rinsing process is available in the free fleet.

In a washing machine according to DE 41 38 636 A1, the water supply takes place in one Standstill phase of the loaded laundry drum until it reaches over a level switch predetermined target levels. Then the laundry moved for a limited time, so that depending on the absorbency of the laundry sets a water level that falls below the target level. Now it is at the target level refilled and the elapsed time measured. The measurement result is the amount of water to be refilled in the subsequent washing processes. So again there is not the suction behavior and thus the water requirement during the actual rinsing, but during at least one preceding one Program section determined. Added to this is the considerable one additional control engineering effort for only temporarily moving the Laundry and to determine the starting level for the next following Refill process up to the switching level. That seems inadequate because for optimal moistening in the rinse cycle depending on the type and nature the laundry needs a water before the free fleet is made available exists, which is not optimal from the switching level of the necessary for washing Can derive water level. Sufficient free liquor in the rinse cycle (and more than in the wash cycle) is a prerequisite for the fact that at the least Water consumption the dirt residues and detergent residues optimally from the Items to be washed out.

GB 20 54 907 A, FR 2 550 560 A and DE 28 18 062 A deal under different aspects with the determination of a tub for the Amount of fresh water supplied to the wash cycle by measuring the inflow time to Response of a level switch, but without taking into account the pumping speed the filling currently in the tub and therefore in particular also without the problem of an optimal one with regard to the free fleet Flushing process. For rinse cycles, however, is as a rule as already mentioned to aim for a higher water level than for washing processes: the amount of free fleet, i.e. the amount of water not bound in the laundry, should Rinse cycles should be larger than for wash cycles. The object of the invention is a method of the beginning Specify the type mentioned by the tax-related simple way to fill the water in rinses adapted to the respective laundry is improved.

According to the invention, the above object is characterized by the features of characterizing part of claim 1 solved.

It is assumed that the laundry is out previous washes is wet and that before Start the rinse cycle with the water in the tub the target level or is pumped out. To The rotation of the washing drum begins at the beginning of the wash cycle switched on and the filling valve opened. The length of time from opening the filling valve to reaching the Target levels elapse, is by the control unit measured. This length of time is a measure of how much Water the respective laundry when moving in the Rinse cycle starting from the moist state receives. If the period is short, this is due to the fact that the laundry only absorbs a little water. Is this Time longer, then this is due to the fact that the Laundry absorbs more water and / or the pro The amount of water flowing in is small - for example at low water pressure Water supply network -. After this pre-fill phase it will Filling valve is not closed and preferably too the rotation of the laundry drum is not interrupted, but water will continue to flow as the drum rotates let in during a filling time (Filling phase), which - determined by the control unit - with a long pre-filling phase longer than with a short one Pre-filling phase. The filling phase is preferred proportional to the pre-fill phase.

After the filling phase, the filling valve is closed, whereby the laundry drum can continue to rotate. It will a water level that is higher for rinse cycles than in wash cycles and the respective pumping speed of the Items to be washed in the rinse cycle are adjusted.

There is no additional one for the described method Level switch or a level switch with one for the Additional switching level necessary for rinse cycle. The water level in the rinse cycle is from the same level or level switch determined that for the level in previous Wash cycles is provided. This represents one technical simplification for the washing machine.

The filling process described comprises two phases. He is one stage, however, because between the two phases Filling valve is not switched on and off. Moreover the filling process runs during the rinsing movement of the Washing drum. Both have the consequence that the Control unit, which is usually a program drum has, can be easily set up because less Program steps as required in the prior art are. Also in connection with the program drum standing microprocessor can be of a simple type his.

Advantageous refinements of the invention result from the subclaims and the following description of an embodiment.

The figure shows filling diagrams of a rinse cycle.

A washing machine has one in a tub rotating drum. Water is in the Solution container can be admitted through a filling valve. At the A level switch is provided on the tub a target level Ns responds. Wash liquor is by means of a Pump can be pumped out of the tub. The functions the washing machine - especially water intake, heating, Drum movements, draining - are done by one Control unit, for example a hybrid control unit with program drum and microprocessor, controlled. Essential parts of the program are washing, rinsing, Fling. Such washing machines are state of the art.

The essential processes according to the invention are in described the following:

After a wash cycle, the wash liquor is suctioned off. If necessary, it is thrown in between. The laundry is moist and the water level in the tub (free fleet) is low or approaches zero. In any case, it is below the target level Ns.

A rinse cycle should now follow. For this switches the control unit rotates the laundry drum and opens the filling valve so that when turning Washing drum fresh water flows into the tub and the laundry moved by the laundry drum water up to the limit of its absorbency.

The control unit measures the time period tv from the beginning the wash cycle until the target level Ns is reached elapses.

The target level Ns is not one for the rinse cycle necessary water level, but to one for the previous ones Measure the necessary water level for washing and thus lower than desired for a rinse cycle. The Desired level Ns is preferably such that at one Wash cycle with the smallest water level required Sufficiently large amount of not bound in the laundry Water is available. This is usually in the cooking program or the case in colored laundry programs.

Is the target level Ns reached in the rinse cycle, i.e. the Run through the pre-filling phase, then the laundry drum turns continues and the filling valve remains open. The The program drum does not have to be a previous switching state change and thus have no relevant cams.

The filling valve remains during a filling phase (Filling time tz) opened further. Their duration is of the Control unit, specifically its microprocessor, determined in proportion to the duration of each Pre-filling.

In the figure there are two possible example curves for different water-absorbent laundry loads shown. Curve 1 shows a case in which the duration tv1 Pre-fill time is comparatively short, the target level Ns is achieved comparatively quickly because that is already in the previous wash cycle only dampened laundry absorbs comparatively little water. Accordingly the control unit provides a comparatively short duration tz1 for the filling time.

After the filling time tz1, the control unit does this Filling valve closed. It is then the water level N1 in reached the tub. This water level N1 includes one of the loading type of the Drum and component dependent on the type of laundry. He is about the fill time stored in the control unit tz1 set so that it for the rinse this Items to be washed are sufficiently high, but for reasons of Water saving is not unnecessarily high. After this Closing the filling valve runs the laundry drum in the Rinse cycle, at the end of which a pump down he follows.

Curve 2 shows a case in which a longer one Pre-fill time tv2 from opening the fill valve to Reaching the target level Ns is measured. This longer one The pre-fill time tv2 arises because that comes from the previous wash cycle moistened current laundry more Water soaks up as the laundry leading to curve 1. As a result, the control unit sets a fill time tz2, which is longer than the filling time tz1. At the Switching off the filling valve is therefore a water level N2 reached, which is higher than the water level N1. This is expedient because for the rinse cycle on the laundry load, which is more until the target level Ns is reached Water absorbs as the laundry load according to curve 1, one larger amount of free water is advantageous.

Influencing the filling time tz as a function of the pre-fill time tv is also different Water network pressures and / or water inflow quantities per Unit of time in their influence on the respective Water level N1 or N2 off. Because if water inflows more slowly, for example, the target level becomes Ns reached later, so that the filling time tz from the Control unit is easily extended accordingly, so that despite the slow water inflow again the water level N1 or N2 is reached.

The for the rinse cycle of the respective laundry load or respective items to be washed, favorable water levels N1, N2 thus achieved without the level N1 and / or N2 through the level switch or additional Level switch must be detected.

If there are several rinse cycles in the program, then the processes described are repeated for everyone Rinse cycle, so that in each rinse cycle always with the for water volume optimized for each laundry becomes.

If there is a requirement that in successive Rinse cycles - with the same load of laundry - with different water levels N1 or N2 worked this can be stored in the control unit. The control unit then provides, for example, each next rinse a gradually longer filling time tz on if in successive rinse cycles increased water level is desired.

The filling time tz can also be taken by other measures to be influenced. For example, is that Operating option "intensive rinsing" on the washing machine provided, then can be controlled by the user the filling time tz are extended, whereupon the Rinse cycle a higher water level than N1 or N2 established.

If the foam formation in the laundry drum is detected, then the control unit can respond to a corresponding signal extend the filling time tz accordingly.

Claims (4)

1. Method of rinsing laundry washed in a washing machine, in which the washing machine has a control unit and a washing-solution container with a sensor for the desired level of the water during the washing cycle, and with a laundry drum for holding the laundry as well as with a feed or inlet system and a pumping-out system, and
   in which the rinsing cycle is carried out with a water level which is higher than that of the washing cycles,
   in which the washing solution from a just completed washing cycle is pumped out of the washing-solution container, at which point
   the laundry drum containing the laundry soaked through by the preceding washing cycle is again set rotating and
   the water-inlet valve is opened,
   so that, as the laundry drum revolves, fresh water flows into the washing-solution container,
   the open period (tv) until the level sensor responds being measured, during which period the laundry has first of all absorbed the incoming water to the limit of its absorptive capacity, prior to the water level of the now free quantity of liquid rising until the desired-level sensor responds, and
   the water-inlet valve then remains open during the continued rinsing motion of the laundry drum over a further period, i.e. filling-up time (tz), which is proportional to the earlier open period up to the response of the desired-level sensor,
   after which the water-inlet valve is again closed and thus, irrespective of the absorptive capacity of the laundry, the rinsing cycle is completed with a quantity of water which is optimized in respect of the actual loading of the drum.
2. Method according to Claim 1,
   characterized in that
   the duration of the filling-up time (tz), i.e. the filling-up stage, is extended, particularly in stages, from rinsing cycle to rinsing cycle.
3. Method according to one of the preceding claims,
   characterized in that
   the duration of the filling time (tz) can be extended by a control option.
4. Method according to one of the preceding claims,
   characterized in that
   the duration of the filling time (tz) can be influenced as a function of a signal registering suds in the laundry drum.

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