FR2796659A1 - DEVICE FOR MONITORING THE DEGREE OF FILLING IN THE TANK OF A PROGRAM-CONTROLLED WASHING MACHINE - Google Patents

Abstract

The invention relates to a device for monitoring the degree of filling of the detergent tank of a washing machine controlled by program. The washing machine comprises an electronic program control installation, respectively a microprocessor control as well as a level sensor making it possible to detect at least one return switching point which corresponds to a minimum water level in the detergent tank as well. that a plurality of different switching points which each correspond to a determined filling level. The monitoring device is characterized in that a plurality of filling volumes of the detergent tank are defined by a corresponding value respectively depending on the water level to which the level sensor is supposed to react, and these values and the quantities of associated filling volumes are stored in the program control. The invention is particularly applicable to washing machines.

Description

The invention relates to a device for monitoring the degree of

  filling in the washing tub of a washing machine controlled by program, in particular of a washing machine comprising an installation for electronic program control respectively microprocessor control and a level sensor by means of which at least one point can be detected rear switching point which corresponds to a minimum water level in the detergent tank, and a plurality of different switching points which each correspond to a determined filling volume. o It is known from document DE 39 09 021 A1 a method of filling the detergent tank of a washing machine o at the very start of the program, the quantity of water conveyed is detected by a measuring device by the intermediate of the operating times of the magnetic valve until a set level is reached, and the measured influx duration then serves as the basis for the calculation of other water influx durations during the stages of following program. In this filling process taking place as a function of time, it is however necessary to take into account the effect of the different pressure ratios in the network of water pipes so that the measured service life of the magnetic valve can also be evaluated as a characteristic quantity of the quantity of water supplied to the control unit of the program control installation. To eliminate fluctuating or insufficient water pressures as a possible source of error, it is also known to control the inflow of fresh water for different water levels in the detergent tank by a water level regulator. (pressure switch, level selector). Such a water level regulator operates in such a way that when the desired water level (set level) is reached, by a switch or an electronic component, a magnetic valve controlling the flow of fresh water is closed and therefore the flow of water to the detergent tank is interrupted. When a certain level of water (reverse switching level) in the detergent tank is reached by the absorption of fresh water supplied to the detergent tank, the flow of fresh water for replenishment is returned possible again by opening

of the magnetic valve.

  In the case of the filling operation of the detergent tank controlled in this way, however, depending on the geometry of the detergent tank, three equidistant levels in the detergent tank of, for example, 10 mm of filling level or 20 mm filling level or 30 mm filling level do not necessarily correspond to equal amounts of water, i.e. for example to fill the detergent tank to a filling level of 20 mm , for a filling level present of 10 mm, 1.5 liters of water must be conveyed. On the other hand, to obtain a filling level of 30 mm in the detergent tank, when

  from a filling level of 20 mm, 2.5 liters of water are required.

  Achieving filling levels determined in the detergent tank of a washing machine using differential values is therefore completely imprecise and is not suitable in practice for filling detergent tanks with

different geometries.

  The object of the invention is therefore to indicate a device for filling the washing tub of a washing machine which operates, on the one hand, independently of the flow oscillations in the network of water pipes and by which is excluded, on the other hand, an unnecessary influx of water into the laundry tub

  and therefore a waste of water is avoided.

  This object is achieved by the device according to the invention because a plurality of filling volumes of the detergent tank are determined respectively by a corresponding value depending on the water level, to which the level sensor must each times, and that these values and the corresponding filling volume quantities of the detergent tank are stored in the program control. To do this, it is useful to proceed in such a way that the different quantities of the filling volume of the detergent tank and the values depending on the water level, characterizing a determined filling volume of the detergent tank, for the reaction of the level, are kept in the form of a table and are memorized. According to another characteristic of the invention, it can be derived from the respective values depending on the level of water in the detergent tank.

  corresponding pressure value for the reaction of the level sensor.

  According to yet another characteristic of the invention, the filling volumes of the detergent tank are indicated on the table in liters, and the corresponding values (quantities) for the reaction of the level sensor are

  refer to the state of water in the detergent tank.

  Finally, according to another characteristic of the invention, the table can present an additional column in which are written the average values of the pressures obtained during a movement of the washing drum in accordance with the individual filling volumes and are set up.

  memory in program control.

  The invention will be better understood, and other objects, characteristics, details and advantages thereof will appear more clearly during the course of the invention.

  explanatory description which will follow made with reference to the single figure

  attached, representing a table, indicated only by way of example

  illustrating an embodiment of the invention.

  In the table, it is indicated in a column the volume of filling of the detergent tank in liters, and in another column the level of water indicating each time a filling volume determined in the detergent tank in millimeters. From the values depending on the water level in the detergent tank can be deduced a pressure value

  corresponding to the reaction of the level sensor.

  According to the exemplary embodiment, a quantity of water of 1.5 liters must be added to the detergent tank, during the course of a program. In the detergent tank was detected a current water level of 6 mm which, according to the table, corresponds to a filling volume of the detergent tank in the size of 2 liters and thus produces a corresponding initial pressure A. By the influx of 1.5 liters of water, a total quantity of water of 3.5 liters is then obtained in the detergent tank which, according to the table, is characterized by a water level of 15 mm in the laundry tub. This

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  water level corresponds to a defined pressure value B by which a level sensor or the like is triggered and which causes in a way

  experienced an interruption in the flow of water to the laundry tub.

  However, this filling operation is generally carried out when the drum is stopped. In order to be able to carry out such filling operations also when the drum is rotating, it is necessary to complete the table with an additional column in which the average values of the pressures obtained during the movement of the drum are recorded in accordance with the different filling volumes.

  and are stored in the program control.

  The table stored in the program control, during a correspondingly designed program control installation, also allows the execution of a calculation operation for

  determine the average flow rate.

  Example: An operation of filling the detergent tank with a water level of 12 to 19 mm takes 12 sec. Thus, in the case of a corresponding initial filling volume of 2.8 liters up to the corresponding final filling volume of 4.4 liters, 1.6 liters of water flow during this period of time. This inflow corresponds to 0.13 liters per second respectively to 8 liters per minute. By this calibration step, also temporary inflows can be integrated with greater precision, or we can see how much water was transported in total during a step of

  program or during the program.

  On the one hand, the table can be stored in memory, for all devices, from the start in software. However, it is also possible, during manufacture, during a precisely defined influx of water, to fill in the table at the end (storage in the range of the processor EEPROM memory by a selective interface). Thus, each washing machine receives a table which corresponds, free from tolerances, to the geometry of its

Laundry.

  The proposed device is achievable at an advantageous cost since additional components such as sensors, if necessary with evaluation electronics, are not required. The quantities used are already present on the complete electronics and can be processed in the microprocessor also already present which controls the functions of the

washing machine.

Claims (5)

Claims   1. Device for monitoring the degree of filling in the detergent tank of a washing machine controlled by program, in particular of a washing machine comprising an electronic installation for program control, respectively a microprocessor control as well as a sensor for level by which at least one return switching point can be detected, which corresponds to a minimum water level in the detergent tank as well as a plurality of different switching points which each correspond to a determined filling volume, characterized in that a plurality of filling volumes of the detergent tank are defined respectively by a corresponding value, depending on the water level, to which the level sensor must react respectively, and that these values and the volume quantities associated fill are set   memory in program control.   2. Device according to claim 1, characterized in that the different quantities of filling volume of the detergent tank and the values depending on the water level, characterizing a determined filling volume of the detergent tank, are kept in the form of table for the reaction of the level sensor and are stored as a table in   installation of program control.   3. Device according to one of claims 1 or 2, characterized in that it   can be derived from the respective values, depending on the water level in the detergent tank, a corresponding pressure value for the reaction of the level sensor.   4. Device according to one of claims 1 to 3, characterized in that   the filling volumes of the detergent tank are indicated in the table in liters, and that the corresponding values (quantities) for the reaction of the   level sensor relate to the water level in the laundry tub.   5. Device according to claim 2, characterized in that the table is provided with an additional column in which are written the average values of the pressures determined during a movement of the washing drum in accordance with the individual filling volumes and are set   memory in program control.