JP2008149134A - Method for controlling washing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method with which the functionality of a washing process or operating process of a washing machine or the evaluation of a conductance sensor can be improved. <P>SOLUTION: This washing machine is constructed with a special control unit and the conductance sensor in a washing liquid container for detecting a water level including whether the water is above or below a given water level. The control unit can control the operation of a pump, as well as the addition of fresh water for eliminating excessive foam in the washing liquid container and in a drum. It is also possible to stop the drum to discharge disturbing foam. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for controlling the operation of a washing machine, in which a conductivity sensor is arranged in a washing or washing soap container of the washing machine.

In order to control the operation of the washing machine, for example according to US 2006/0191496 A1 or EP 633 342 A1, a conductivity sensor is arranged inside the washing machine, for example in the lower part of the washing container It is well known. The measured value of this conductivity sensor is judged and evaluated by the washing machine control device. However, the possibilities for further processing or utilization of these measurements as described in said patent are limited.
US Patent No. 2006/0191496 A1 European Patent No. 633 342 A1

  An object of the present invention is to provide a method capable of improving the functionality of the washing process or the operation process of the washing machine or the evaluation of the conductivity sensor.

  This object is achieved by a method having the features of claim 1, 3, 5, 6, 9 or 12. Advantageous and preferred developments of the invention form the subject matter of further claims and are described in more detail below. In particular, it is also possible to combine some of the embodiments according to the invention. By express reference, the wording of the claims is incorporated into the contents of this specification.

BEST MODE FOR CARRYING OUT THE INVENTION

  In the first basic development form of the present invention, the conductivity sensor detects the water level, and when the water level falls below the position of the conductivity sensor, the drainage of the washing container, that is, the drainage by the pump in particular. Stopped. This makes it possible to prevent the pump from operating when the drainage of the washing container pump is completely finished, thereby avoiding unnecessary power consumption on the one hand and accurately on the other hand. This prevents unpleasant audible noise when the drum is not rotating.

  In particular, when the pump is used for draining the washing container, it is advantageous that the pump is switched off with a delay of a few seconds after the water level drops below the conductivity sensor. Such a delay is particularly consistent with the fact that at a standard pumping capacity, the water level is indeed reduced somewhat below the conductivity sensor, but the pump is prevented from operating or inhaling air in the pump. It can be said. As a result, it is possible to ensure that the pump is operated in an almost optimal range, that is, that the washing container is drained to just above the pump or the water level is lowered. However, this is not critical because the pump can be switched off when the water level falls below the pump. The important thing is to determine where the water level is relative to the pump to prevent any noise.

  According to yet another basic development of the invention, the conductivity sensor is configured to detect whether it is surrounded by foam in the washing process. This can be detected in cooperation with the washing machine controller or the conductivity sensor controller, rather than by the conductivity sensor alone. Fresh water is added as a measure to reduce or eliminate foam. This will at least dilute the foam or wash liquid and remove as much foam as possible. Therefore, the detection of bubbles on the conductivity sensor is possible with a high reliability level within the scope of the present invention. In particular, in the case of a capacitive conductivity sensor, the measured value of the bubble state in the conductivity sensor is between the measured value for air and the measured value for when the sensor is surrounded by water.

  Here, advantageously, as a measure when foam is present, it is ensured that the conductivity value is substantially or particularly preferably always surrounded by water during the washing process or during drum rotation. It is also possible to add fresh water in an amount or time. This prevents the negative effect of excessive foam during washing.

  According to another basic development form of the present invention, it is possible to detect the surface tension of the washing liquid or the washing liquid in the drum by using the conductivity sensor as a means to judge the ion concentration in the washing liquid. become. Based on this, it is possible to determine whether or not a specific surface tension has been exceeded and whether or not washing or rinsing of the laundry can be terminated. In this way it is possible to determine whether the detergent has been properly rinsed from the laundry. This makes it possible, for example, to adapt the length or number of rinsing steps as a function of the detected ion concentration. The rinsing process is continued until, in particular, the ionic concentration or surface tension has already exceeded a certain predetermined value, so that the laundry is considered properly rinsed.

  According to yet another basic development of the invention, in the centrifugal dewatering process, in particular, the pump is always operated, just until the conductivity sensor is roughly continuously or even constantly surrounded by water. It becomes possible to increase the speed. This is because initially the laundry is still very moist so that enough water is drained from the laundry so that the water level is above the conductivity sensor. It means that a dehydration rate is used. Typically, the pumping capacity is limited, or the pump is always operated at maximum capacity, so if the water cannot be drained by the pump in a timely and sufficiently rapid manner, the laundry will be centrifuged at a higher speed. It does not make much sense to dehydrate and drain more water. Furthermore, the laundry in the drum should always be swung under the water at the bottom of the washing container and become wet again, which should be prevented.

  In addition, it is advantageous that the centrifugal dehydration is only performed when the conductivity sensor is completely or substantially no longer surrounded by water after being continuously or substantially surrounded by water for a long time, in particular several minutes. It becomes possible to increase the speed. This means that the pump can cope with the moisture removed from the laundry and the moisture can be removed, so that centrifugal dehydration can be carried out at a higher strength and speed. Particularly preferably, the centrifugal dewatering rate can be slowly increased until the conductivity sensor is again substantially or constantly surrounded by water. This can be repeated multiple times and the centrifugal dewatering rate can be increased even further. By slowly increasing the centrifugal dewatering speed in this manner, unnecessary and early or rapid rotation of the drum and the accompanying power consumption and bearing wear can be prevented.

  Advantageously, the operation of the pump can be controlled by means of the conductivity sensor and the measured value of the sensor. For example, when the maximum centrifugal dewatering rate is reached, the pump can be switched off again if the conductivity sensor is completely or substantially not surrounded by water. Advantageously, the pump is switched on again only when the conductivity sensor is constantly or substantially surrounded by water. This makes it possible to ensure that the pump is not operated continuously at the maximum centrifugal dewatering speed. Certainly, the operation of the pump with air suction is much less noise than the centrifugal dehydration operation, so that it is not serious with respect to the noise problem especially at high speed centrifugal dehydration. However, unnecessary power consumption and pump wear can be reduced.

  Particularly advantageously, the state change in the conductivity sensor, i.e. the state when the sensor is substantially surrounded by water and the state when the sensor is substantially exposed and the switch on and off of the pump. Between cuts, as described above, it is possible to provide a waiting time over a time interval of several seconds. This time interval can be, for example, in the range of 5 to 30 seconds, in particular 10 to 20 seconds. By providing this short time interval as described above, it can also be ensured that when the pump continues to run, additional water is drained by the pump until the pump is about to run. If the water level rises while the pump is stationary, it will wait until the water level is just above the conductivity sensor but not reaching the laundry again. Thereby, the frequency of pump operation decreases.

  According to another basic development form of the present invention, as described above, it is possible to determine whether the sensor is surrounded by water, bubbles or air on the conductivity sensor. Become. Thereby, in the centrifugal dehydration process, when bubbles are detected by the conductivity sensor, the drum speed can be decreased. Lowering the drum speed is a measure to reduce foam formation because it reduces or eliminates the impact of foam by the drum passing through the foam. The deceleration can be 10-30%, for example. In particular, the speed can be slow or reduced in steps until the conductivity sensor is no longer surrounded by bubbles. In certain situations it is even possible to stop the drum completely if the conductivity sensor is still surrounded by bubbles. Particularly advantageously, it is possible to wait for several minutes, for example up to 5 minutes, after the drum has stopped. If the conductivity sensor is still surrounded by foam or detects foam, yet another measure can be used to introduce fresh water to rinse the foam. After the introduction of a certain amount of time or a certain amount of fresh water, a test is performed again to determine whether the conductivity sensor is surrounded by bubbles. If surrounded, additional fresh water can be added until the bubbles are resolved. As still another inspection means, the pump can be started. And when the pump is idling, the idling of this pump can be easily determined by measuring the power consumption of the pump, and if this continues for a few seconds to a few minutes, there is still a bubble in the conductivity sensor. Become.

  According to yet another basic development of the present invention, the washing or rinsing step is more particularly performed in the method of operating the conductivity sensor or when measuring the conductivity in the washing container or in the washing liquid. It is possible to temporarily interrupt the dehydration process and perform conductivity measurements. In particular, in the case of interruption or conductivity measurement, the drum can be stopped and then the conductivity is measured with the drum stationary. This prevents the washing liquid from being shocked by the operation of the drum in the washing container to form bubbles. Furthermore, it is possible to calm the water in the washing container, which also allows a better and more reliable conductivity sensor evaluation.

  Furthermore, within the scope of the present invention, it is possible to determine whether or not the heater is in water within the above-described water level measurement frame using a conductivity sensor. It is also possible to eliminate one of the safety circuits. Thereby, the structure of a washing machine can be made simpler.

  These and other features are set forth in the following claims, description, and drawings, and individual features may be implemented in the embodiments of the present invention and in other fields, either individually or in combination. And may represent an advantageous structure that can be protected independently, claiming protection here. The subdivision of this application into sub-items and subheadings do not limit the general effectiveness of the contents described below in any way.

  Embodiments of the invention will now be described in conjunction with the accompanying drawings.

  FIG. 1 illustrates a washing machine having a drum 13 containing a laundry object or laundry 14 according to an embodiment of the present invention. The drum 13 is driven by a motor 15 using belt transmission. The washing or soap bar is disposed under the drum 13 and surrounds the drum and has an outflow portion 18. The outflow part 18 leads from the washing machine 11 to the pump 20 that drains the water in the washing container 17 through the drain hose 21. The heater 23 protrudes into the washing container 27 and heats the water or the washing liquid in the container. In FIG. 1, the inflow portion of fresh water and detergent mixed water is not shown. However, in the same way as the washing machine described in this regard, the inflow can be configured in the same way as in the prior art.

  In the illustrated embodiment, the conductivity sensor 24 protrudes in the washing container 17 in the vicinity of the heater 23, as is known, for example, from US 2006/0191496 A1. In other words, the conductivity sensor 24 defines a dashed water level 25 that indicates the maximum height at which it can detect water or bubbles, as will be further described below. This conductivity sensor 24 is also connected to a control device 26 which is also connected to the pump 20 and / or the heater 23 and in particular can control the pump and / or the heater or evaluate its operating state. . The motor 15 can also be connected to the control device 26 and controlled by the control device and additionally or alternatively can detect its operating state as described above.

  As described above, the conductivity sensor 24 can determine, for example, whether water or bubbles are located above or below the water level 25 or whether the sensor is immersed in water. This can be critical especially with regard to the pump operation described above. Furthermore, it is pointed out here that the conductivity sensor 24 and the water level 25 are well below the lowest point of the drum 13. Thus, the water level can rise far above the conductivity sensor 24 or the water level 25 without reaching the drum 13 and the laundry object 14 in the drum and rewetting the laundry. Taking into account this height difference in relation to the possibility of the hysteresis curve, the pump 20 is after a certain time when the water rises above the water level 25. Must always be switched on in a timely manner before the water reaches the drum 13. The same applies to the case where water is lowered below the water level 25 to the extent that the pump 20 does not operate during drainage.

  The different possible methods have already been described and will become more apparent in connection with FIG. 1 without further elaboration here.

  FIG. 2 shows a method which makes it possible to measure the surface tension of the contents of the drum 13, in particular the laundry liquid containing the laundry 14, based on the surfactant concentration. There is a certain relationship between the surface tension and the surfactant concentration, and in particular the controller 26 can derive the conclusion from this relationship.

  Similarly, conductivity and surfactant concentration are in a certain correlation as shown in FIG.

  Finally, according to FIG. 4, the conductivity can be related to the surface tension of the washing liquid in the drum 13 or the washing container 17. Thus, a linear relationship is obtained for different surfactants and different surfactant concentration ranges, ie, ranges 1-4 in FIG. If the surfactant concentration range is known, for example, if the surfactant concentration is very high during the washing process, a conclusion regarding the surfactant concentration can be derived based on the conductivity from the conductivity of the wash liquor. . However, when the surfactant concentration is low, for example, when the laundry 14 is rinsed in the drum 13, the conductivity can be determined from the predetermined relationship. Advantageously, the control device 26 is aware of the predetermined program sequence in order to constitute a complete control device for the washing machine 11, so it is also known whether the washing step or the rinsing step is performed. ing. The exact type of surfactant used is not necessarily known because it is based on an initial value and a change in concentration can be detected using a random surfactant. Thereby, the said washing | cleaning and rinse process can fully be optimized. In particular, different curves according to FIG. 4 can be stored in the controller 26 and used for detection.

  This specification is based on the disclosure content of German Patent Application No. 102006060256.0 filed on Dec. 14, 2006, and the disclosure content of this German Patent Application No. 102006060256.0 is Part of it.

It is a diagram which shows the inside of the washing machine of this invention. FIG. 5 is a different graph showing the relationship and relationship among surfactant concentration, surface tension and conductivity. FIG. FIG. 5 is a different graph showing the relationship and relationship among surfactant concentration, surface tension and conductivity. FIG. FIG. 5 is a different graph showing the relationship and relationship among surfactant concentration, surface tension and conductivity. FIG.

Claims (18)

  In a method of controlling the operation of a washing machine having a control device, a washing container, and a conductivity sensor disposed in a lower portion of the washing container, a measured value of the conductivity sensor is detected and the method A method in which a point in time when the water level drops below the position of the conductivity sensor is detected and the drainage of the washing container is stopped as a result.   The method according to claim 1, wherein a pump is provided for draining the washing container, and the pump is switched off after several seconds.   The delay is a reasonable delay to reduce the water level even further below the position of the conductivity sensor without causing operation or inhalation of air into the pump from the pump. Item 3. The method according to Item 2.   In a method for controlling the operation of a washing machine having a control device, a washing container, and a conductivity sensor disposed in a lower portion of the washing container, a measurement value of the conductivity sensor is detected, and the control In the washing process, the conductivity sensor detects whether or not it is surrounded by foam, and if it is surrounded by foam, as a measure for dilution of the foam in the washing machine How fresh water is added.   The method of claim 4, wherein sufficient fresh water is added to ensure that the conductivity sensor is substantially surrounded by water during the washing step or rotation of the drum.   In a method of controlling the operation of a washing machine having a control device, a washing container, and a conductivity sensor disposed in a lower portion of the washing container, a measurement value of the conductivity sensor is detected, The conductivity sensor, which is supplied to the control device, detects the surface tension of the water in the drum or the washing liquid by detecting the ion concentration in the washing liquid, and first exceeds a predetermined surface tension. A method in which whether or not the laundry is rinsed and the length or number of times of the rinsing process is adapted independently of the ion concentration.   In a method of controlling the operation of a washing machine having a control device, a washing container, and a conductivity sensor disposed in a lower portion of the washing container, a measurement value of the conductivity sensor is detected, In the centrifugal dehydration process, the increase in the centrifugal dehydration speed is limited to the time when the conductivity sensor is constantly surrounded by water.   The method according to claim 7, wherein a pump is provided for draining the washing container, and the pump is continuously operated during the centrifugal dehydration step.   8. The method of claim 7, wherein the centrifugal dewatering rate is increased only when the conductivity sensor is surrounded by the water for a long time and is no longer surrounded by the water.   The method of claim 9, wherein the centrifugal dewatering rate is slowly increased until the conductivity sensor is again substantially surrounded by water.   The method of claim 9, wherein the extended time is a few minutes.   The method according to claim 11, wherein operation of the pump is controlled by using the conductivity sensor or a measured value of the sensor as a means.   When the conductivity is not surrounded by the water when the centrifugal dewatering speed reaches a maximum, the pump is switched off and the conductivity sensor is surrounded by the water. 13. A method according to claim 12, wherein only the switch is switched on again.   14. The method of claim 13, wherein there is a time interval of a few seconds between a change in function in the conductivity sensor and switching on or off of the pump.   In a method of controlling the operation of a washing machine having a control device, a washing container, and a conductivity sensor disposed in a lower portion of the washing container, a measurement value of the conductivity sensor is detected, When the presence of the foam is detected in the centrifugal dehydration process, it is determined whether the sensor is surrounded by water, foam, or air. As a countermeasure for reducing the formation of water, a method in which the centrifugal dehydration speed of the drum is reduced.   Using the conductivity sensor as a means, it is determined that the foam has already been properly reduced or not surrounding the conductivity sensor, otherwise the drum is completely stopped. 15. The method according to 15.   17. If the foam is still detected by the conductivity sensor after the stop of the drum, fresh water is introduced into the drum after waiting for several minutes to rinse off the foam. Method.   In a method of controlling the operation of a washing machine having a control device, a washing container, and a conductivity sensor disposed in a lower portion of the washing container, a measurement value of the conductivity sensor is detected, Supplied to the control device, the washing or rinsing process is temporarily interrupted to perform the conductivity measurement, and for the interruption, the drum is stopped, and then the conductivity with the drum stopped. The method by which the measurement is made.

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