FR2883890A1 - METHOD FOR SERVICING ONE OR MORE PARAMETERS OF A WASHING PROCESS AND MACHINE USING SUCH A METHOD OF SERVICING - Google Patents

Abstract

A method of controlling one or more parameters of a washing process is adapted to set the value of the parameter (s) according to at least one dependent function of the type and / or amount of detergent used in the washing process. Use in particular for controlling the rinsing of the textile in a washing machine (10).

Description

The present invention relates to a method for controlling one or

  several parameters of a washing process.

  It also relates to a washing machine, and especially to wash the laundry, washing machine type or washer-dryer for domestic use, adapted to implement the servo process according to the invention.

  In general, the present invention relates to the field of washing and aims to enslave one or more parameters of the washing process (washing, rinsing, spinning) to adapt it to the washing conditions.

  The present invention thus aims in particular to improve the effectiveness of the washing or rinsing implemented.

  Washing machines are already known which propose several washing programs, depending in particular on the type of textile to be washed.

  These washing programs are thus generally modified in terms of the duration of the washing phase, or else the maximum speed of rotation of the drum during a spinning phase between different rinsing phases.

  In addition, these conventional washing processes generally comprise several intermediate spinning operations intended to evacuate a maximum of dirty water from the laundry between different rinsing phases.

  Indeed, the greater the amount of water discharged in each rinsing phase is important, the greater the amount of detergent extracted from the textile rinse bath following is important, and therefore will be the best rinse result.

  Also, in current washing machines, the intermediate spinning are relatively long, between 5 and 8 minutes, and made at high speed of the rotary drum, of the order of 1050 revolutions / minute. These intermediate spinning have the disadvantage of accelerating the wear of the laundry and its crumpling. They also cause significant noise, of the order of 70 dBA.

  The present invention aims to optimize the performance of a washing process while minimizing the consumption of water and energy, and possibly the noise constraints.

  For this purpose, the present invention relates to a method for controlling one or more parameters of a washing process, in which the value of the parameter or parameters is set according to a function dependent on at least the type and / or the quantity. detergent used in said washing process.

  The Applicant has found that the type and / or amount of detergent used, which may be for example in the form of liquid, compact or dispersed powder, have a strong influence on the efficiency of the rinsing and washing.

  By adapting a parameter of the washing process to the type and / or quantity of detergent used, it is possible to enslave the washing process in the best possible manner and thus to limit the mechanical stresses to the strict minimum necessary.

  According to a practical embodiment of the invention, the servo-control method comprises a step of determining the type and / or amount of detergent used in the washing process, this determining step comprising a step of measuring the conductivity of a detergent bath.

  It is thus possible from the measurement of the conductivity of a washing bath in which the detergent has been introduced, to discriminate the type of detergent used and in particular to separate liquid detergents from powder detergents, as well as possibly from classify the detergent according to the amount of detergent used.

  In practice, the step of determining the type and / or amount of detergent used comprises a step of calculating a ratio of a predetermined value of the conductivity associated with the feedwater and the measured value of the conductivity of a detergent bath, and a step of comparing said ratio with one or more predetermined threshold values, thus making it possible to classify the detergent used in different categories of detergent.

  When the invention is applied to textile washing, preferably the value of the parameter (s) is set according to a further dependent function of at least the type of textile and the weight of textile to be washed.

  According to one embodiment of the invention, one of said parameters is an intermediate spinning time in a rinsing phase of the textile washing process.

  It is thus possible to adapt the drying time to the type of detergent used, and possibly to the type of textile and the weight of textile to be washed.

  Furthermore, the parameter can also be a maximum rotation speed of a washing drum adapted to contain textile.

  According to another characteristic of the invention, the servo-control method further comprises the following steps: periodic measurement of the conductivity of a rinsing bath during a rinsing phase; - comparison of the conductivity values measured periodically; and determining the end of a rinsing phase when at least two consecutive conductivity measurements are substantially identical.

  Thus, from a measurement of the conductivity of a rinsing bath, it is possible to better control the duration of this rinsing bath, and in particular to stop a rinsing phase when it does not. is more effective in extracting the detergent from the textile.

  Furthermore, according to another practical feature of the invention, the servo-control method comprises the following steps: measurement of the conductivity of a rinsing bath during a rinsing phase; comparing the measured conductivity with a predetermined value of the conductivity associated with the feedwater; and implementing a final rinsing phase when the measured conductivity value is substantially equal to the predetermined value of the conductivity of the feed water.

  By thus comparing the conductivity of a rinsing bath with the conductivity of the supply water of the network, it is possible to best determine the need to implement or not complementary rinsing phases, and thus reduce the overall time of the rinsing bath. washing process, and water consumption, while ensuring an effective rinsing.

  According to a second aspect of the invention, it relates to a washing machine adapted to implement the servo method according to the invention. This machine comprises in particular means for determining the type and / or the amount of detergent.

  This washing machine has characteristics and advantages similar to those described above with reference to the servo-control method which it implements.

  Other features and advantages of the invention will become apparent in the description below.

  In the accompanying drawings, given by way of nonlimiting examples: FIG. 1 illustrates a washing machine adapted to implement the servo-control method according to the invention; FIG. 2 is a curve illustrating the evolution of the conductivity of a detergent bath for different types and / or quantity of detergent; and FIG. 3 is a curve illustrating the profile of the speed of rotation of a drum over the duration of an intermediate spin.

  A washing machine 10 suitable for carrying out the present invention will be described first with reference to FIG.

  This washing machine may be a household washing machine or a washer-dryer.

  In this embodiment, an overhead loading machine has been illustrated. Of course, the present invention applies to all types of washing machine, including front loading.

  In a conventional manner, such a washing machine 10 comprises a washing tub 11 and a drum 12 rotatably mounted, here along a horizontal axis 13, inside this washing tub 11.

  A door (not shown) located on the upper face of the machine allows the user to access the inside of the tank and the drum to introduce or remove the laundry.

  A control panel 14 is also provided in the upper part of the machine.

  Only the specific means for implementing the servo-control method according to the invention will be described hereinafter.

  Of course, the washing machine according to the invention comprises all the equipment and means necessary for the implementation of a conventional washing process in such a rotary drum machine.

  In particular, in this embodiment, the control board 14 includes means for determining the type of detergent.

  Thus, the user can indicate with a selection button the type of detergent used.

  Illustrative here is a possible choice of detergent from an assembly comprising detergents in the form of liquid, gel, compacted (tablet) or dispersed powder.

  Of course, the present invention is not limited to this type of detergent and can be applied to any other presentation.

  On the other hand, the means for determining the type of detergent could be different as long as they are suitable for classifying the detergent among a set of detergents as described above.

  In particular, a sensor placed in a detergent receiving pan could determine the type of detergent used automatically, without user intervention.

  The user must then place the detergent in the tray.

  In addition, the determination of the type and amount of detergent used can be carried out automatically, without user intervention, by means of a conductivity sensor 16 placed in the tank 11 and preferably at the bottom of the tank. The operation of this sensor 16 will be described later.

  In particular, this sensor 16 makes it possible to periodically or continuously measure the conductivity of the washing or rinsing bath present in the tank.

  The washing machine further comprises means for determining the type of textile 17, illustrated here, in a nonlimiting manner, by a selection button allowing the user to select the type of textile from a set consisting for example of cotton type , synthetic, wool.

  Finally, the washing machine in this embodiment comprises means for determining the textile weight introduced into the drum.

  This measurement of the weight can be performed by one of the known weight measuring means based on a pressure switch placed in relation to the tank. Depending on the electrical value measured at the terminals of this pressure switch, it is possible to determine the weight of the laundry introduced into the drum.

  These textile weight determination means can be adapted to define load families associated with a weight range.

  For example, a first family CV1 corresponds to a textile load of between 0 and 2 kilos, a second family CV2 corresponds to a textile load of between 2 and 3 kilos, a third family CV3 corresponds to a textile load of between 3 and and 4 kilos and a fourth CV4 family corresponds to a textile load of between 4 and 5 kilos.

  Of course, these values are given by way of examples and are in no way limiting.

  The sensors for measuring weight and conductivity described above and the selection buttons are connected to the input of a control circuit including in particular a micro processor adapted to implement from the different parameters measured the washing process. This microprocessor is particularly suitable for controlling the rotational speed of the drum, the operation of the heating elements, the duration and succession of the different phases of washing, rinsing and wringing in the washing process, the feeding and the drying. evacuation of the different washing or rinsing baths ...

  This control circuit is preferably integrated on an electronic card placed at the control panel 14.

  We will now describe the servo process implemented in a washing machine as described above.

  In principle, the servo-control method according to the invention is adapted to enslave the value of at least one parameter of the washing process according to at least the type and / or the amount of detergent used in the washing process. .

  In general, a washing process can be broken down as follows: a wash phase (possibly preceded by a prewash phase); - an intermediate spin; a first rinsing phase; - an intermediate spin; a second rinsing phase; - an intermediate spin; a final rinsing phase; and - a final spin.

  Of course, the number of rinsing phases in a conventional program may be different, and in particular greater than three.

  As will be seen below, the number of rinsing phases can be further determined by the control method itself.

  The method of determining the type and / or amount of detergent used in the washing process will first be described in the context of the servo-control method according to the invention.

  To date, there are on the market various types of usable detergent, including liquid detergents, detergents in the form of encapsulated gel, and dispersed powder detergents, or compacted in the form of tablets.

  Of course, the present invention is not limited to the aforementioned forms of detergent.

  The detergent in a washing process is generally introduced by the user at the beginning of the process, either directly into the drum 13 containing the laundry, or into a receiving tray provided for this purpose.

  The determination of the type of detergent can be carried out directly by the user using the selector button 15 previously described.

  Preferably, this can be done automatically by measuring the conductivity of a detergent bath using the conductivity sensor 16.

  In this regard, FIG. 2 illustrates, by way of nonlimiting example, the evolution of the conductivity of a washing bath, as a function of the type of detergent used and of its dosage.

  In this practical embodiment, the conductivity is measured by a sensor integrated in an oscillator assembly. The frequency generated by this oscillator is proportional to the conductivity of the bath, so that the microprocessor of the electronic board can determine the conductivity of the bath from the frequency, or the period, of the signal measured at the output of the oscillator .

  FIG. 2 diagrammatically shows the value of the conductivity measured by the sensor immersed in various detergent baths.

  Here, the signal period is represented as a function of time in seconds.

  As an indication, the YO value of the sensor in the air has been illustrated.

  The conductivity increases slightly when the sensor is immersed in water and has a value Y. The value Y of the conductivity of the water of the supply network is taken into account in the control method which will be described.

  This value is measured and stored during a previous wash cycle during the last rinsing phase.

  A default value can be further memorized to initialize the process. For example, this default value corresponds to a period of 1700 s.

  The evolution of the conductivity in the detergent bath was then illustrated for different types and amounts of detergent.

  Thus, the curve in solid line illustrates the evolution of the conductivity for a detergent in liquid form or gel, in an amount between 50 and 80 ml.

  The short dashed curve illustrates the change in conductivity for a compacted powder detergent in an amount of 40 g.

  The dashed line curve illustrates the change in conductivity for a dispersed powder detergent in an amount of about 100 g.

  Finally, the long dotted line curve illustrates the change in conductivity for powdered detergent in an amount greater than 200 g, corresponding in practice to an overdose of the detergent.

  The evolution of the conductivity thus illustrated corresponds to the beginning of a washing phase of a washing process. The beginning of the washing process can be broken down as follows.

  A first phase corresponds to filling the tank with water, the drum being stationary. The detergent introduced into the receiving tank is thus entrained in the water of the tank. There is then a sudden rise in the conductivity which corresponds to the passage of the detergent in the wash bath.

  A second phase corresponds to a mixing phase of water and lye, the drum being rotated so that the water is absorbed by the laundry and the detergent dissolves little by little.

  It should be noted in this respect that a liquid detergent dissolves relatively gradually in water. On the other hand, the dissolution of a compacted powder detergent (tablet) is relatively longer than that of a dispersed powder.

  After this mixing, a third phase is to add water into the tank, the drum being kept stationary.

  Then a fourth phase with cold stirring and different additions of water is implemented, the drum being driven at low rotational speed. The mixture of water and detergent gradually becomes homogeneous.

  Finally, a fifth brewing phase is carried out with the start of heating the water.

  The drum is also rotated during this fifth phase.

  A measurement of the conductivity of the detergent bath can thus be carried out after the stirring phases, and for example after heating the detergent bath, for example at a temperature substantially equal to 30 C. Thus, a conductivity measurement Y 'is obtained, this value of conductivity with a different value depending on the type and amount of detergent used.

  In practice, the microprocessor implements a step of calculating a ratio of this measured value Y 'of the conductivity of the detergent bath and the predetermined value Y of the conductivity associated with the feed water.

  A comparison step of this ratio is then implemented according to different predetermined threshold values for classifying detergents.

  These threshold values are dependent on the value measured across the oscillator integrating the conductivity sensor and taken into account by the microprocessor.

  These predetermined threshold values may be calibrated during the manufacture of the machine by tests and measurement routines accessible to those skilled in the art.

  In practice, when the ratio Y / Y 'is less than a minimum threshold value, the detergent is of the liquid or gel type, hereinafter referred to as DT1. This minimum threshold value is for example equal to 1.2.

  When the Y / Y 'ratio is between this minimum threshold value and an average threshold value, the detergent used is a compacted powder, hereinafter referred to as DT2. This average threshold value is for example equal to 1.5.

  When the Y / Y 'ratio is between the average threshold value and a maximum threshold value, the detergent used is a dispersed powder, used at a normal dose of the order of 100 g, hereinafter referred to as DT3. This maximum threshold value is for example equal to 3.5.

  Finally, when the Y / Y 'ratio is greater than the maximum threshold value, the detergent used is an overdosed dispersed powder, in an amount greater than for example 150 g, hereinafter referred to as DT4.

  Of course, the method for determining the type of detergent and classification of detergents in the different categories DT1, DT2, DT3, DT4 is given here by way of non-limiting example. In particular, the determination process could be refined by taking into account other conductivity measurements of the detergent bath at different times of the washing process, and for example taking into account a conductivity measurement made at the end of the second phase. , after stirring and before the third water booster phase, thus making it possible to discriminate the compacted powders from the dispersed powders as a function of their more or less rapid dissolution in the water.

  In principle, the process for determining the type and amount of detergent is based on the fact that powdered detergents have a richer and more diverse composition than detergents in liquid form.

  In addition, the liquid detergents are diluted regularly with each addition of water unlike detergents in the form of compacted powder which disintegrate before dissolving in the bath.

  Thus, the classification carried out detergents DT1, DT2, DT3, DT4 allows in particular to classify detergents according to their speed of dissolution in water, from the fastest to the slowest.

  With this recognition of the type and amount of detergent used, it is possible to enslave parameters of the washing process. In practice, we can take into account not only the type of laundry and its dosage, but also the hardness of the feed water used in the machine, the type of textile (cotton, synthetic, wool) and its quantity that can be defined by load family CV1, CV2, CV3, CV4, as indicated previously.

  In particular, one of the parameters that can be controlled by taking into account the type and / or the amount of detergent, is the number of rinsing phases programmed in a washing process.

  In practice, a theoretical washing process is programmed at the microprocessor level, when the user chooses a predefined program. This predefined wash program generally takes into account the type of fabric to be washed, a user-specified wash temperature, and possibly other parameters.

  By virtue of the classification of the detergent used, the slaving process may be adapted to reduce or increase the number of rinsing stages of the theoretical wash process.

  In practice, for example, when the detergent is of the DT3 or DT4 type, the number of rinsing phases can be increased, for example by four, whereas, when the detergent is of the DT1 type, the number of phases of rinsing can be reduced, for example equal to two.

  Similarly, the theoretical duration programmed for each rinsing phase can be increased or decreased from the knowledge of the type of detergent used.

  In addition, in one embodiment of the invention, the servo-control method makes it possible to regulate parameters of an intermediate spin in a textile washing process.

  As illustrated in FIG. 3, an intermediate spinning has different levels of variable duration, corresponding to different speeds of rotation of the drum.

  In the exemplary embodiment illustrated in FIG. 3, the intermediate spinning comprises a first phase of duration D1 for a rotation speed of the drum of the order of 800 revolutions / minute, then a second phase of duration D2 for a speed maximum V rotation drum, shown in Figure 3 at 1050 rpm.

  The servo-control method thus makes it possible in particular to adjust the values of the parameters D1, D2 and V. In particular, the duration parameter D1 and / or D2 of the intermediate spin can be adjusted in the following manner.

  The duration varies between a minimum threshold value for a washing textile weight of less than 2 kilograms (CV1 load) and a fast dissolving detergent (DT1) and a maximum threshold value for a weight of washing textile greater than 4 kilograms (CV4) and slow dissolving detergent (DT3).

  Thus, the duration D1 can vary from 20 seconds for a load of the type CV1 and a detergent of the type DT1 at 120 seconds for a load of the type CV4 and a detergent of the type DT3.

  Similarly, the duration parameter D2 can vary from 20 seconds for a load type CV1 and a detergent type DT1 200 seconds for a CV4-type load and a detergent type DT3.

  The maximum speed parameter V of rotation of the washing drum can also be regulated by the servo-control method.

  This rotation parameter V can vary between a minimum threshold value for a weight of textile to be washed less than 2 kilos (type CV1 load) and a fast dissolving detergent (DT1) and a maximum threshold value for a textile weight washing greater than 4 kilograms (CV4 type charge) and slow dissolving detergent (DT3).

  Thus, the speed V can vary from 1050 revolutions / minute for a CV3-type load and a DT3-type detergent at 800 revolutions / minute for a load of the type CV1 and a detergent of the type DT1.

  Finally, in the case of the determination of an overdose DT4 detergent, the maximum speed may be limited to 800 rpm, for example, in order to avoid the significant creation of foam.

  The variation of the drum rotation time and speed during an intermediate spin phase depending on the weight of the textile to be washed and the type and amount of detergent used has been indicated above.

  Of course, the type of textile to be washed can also be taken into account to modify the values of the various parameters.

  Moreover, the servo-control method can also take into account different periodic measurements of the conductivity of a rinsing bath using the conductivity sensor 16 described above.

  Thus, the method of servocontrol from a periodic measurement of the conductivity of a rinsing bath during a rinsing phase, implements a step of comparing the conductivity values measured periodically and successively, in order to determine the end a rinsing phase when at least two consecutive conductivity measurements are substantially identical.

  Indeed, during a rinsing phase, the detergent trapped in the textile fibers is gradually extracted. The ideal brewing time of a rinsing phase corresponds to the moment when there is a balance between the concentration of detergent in the rinsing bath and that contained in the laundry, any additional extraction of detergent being then impossible.

  In practice, this equilibrium phase results in a conductivity value of the rinsing bath which no longer evolves. Also, by calculating the difference between two successive values of conductivity measurement, with a predetermined periodicity of the order of 1 minute for example, it is possible to determine a rinse phase end when this difference is less than a threshold value. prefixed.

  This servo-control method thus makes it possible to reduce the theoretical or predetermined duration at the beginning of a washing process as indicated above, to take account of the actual evolution of the rinsing phase.

  It makes it possible to shorten the rinsing phases when they are no longer effective and thus to reduce the total duration of the washing process and the water consumption, without affecting the quality of the rinsing.

  Similarly, the control method is adapted, from the measurement of the conductivity of a rinsing bath during a rinsing phase, to compare the value of the measured conductivity with the predetermined value Y of the conductivity associated with the rinsing phase. feed water, to identify the penultimate rinse required.

  This test is based on the principle that the higher the conductivity value measured in the rinse bath is close to the Y conductivity value of the feed water, the less detergent is removed from the laundry. By comparing the conductivity of the water in a rinse bath at the end of each rinse phase, it is possible to determine whether the next rinse can be the last rinse.

  Thus, when the value of the measured conductivity is substantially equal to the predetermined value Y of the conductivity of the feedwater, a last rinsing phase is used, during which a softener may optionally be introduced.

  This servo-control method also serves to control the number of theoretical or predetermined rinse phases at the beginning of the washing process as indicated above.

  It is thus possible to limit the number of rinsing phases, and to reduce the duration of the washing process and the quantity of water consumed, without impairing the quality of the rinsing.

  The present invention thus makes it possible, by measuring the conductivity of the rinsing and washing baths throughout a washing process, to control various parameters of this washing process in order, in particular, to limit the mechanical stresses on the laundry and to limit the acoustic nuisance.

  Of course, many modifications can be made to the embodiment described above without departing from the scope of the invention.

  In particular, the invention has been described for a washing machine. It can also be applied to a dishwasher, the servo process being adapted to adjust for example the duration of the washing phase or the number and duration of the rinsing phases depending on the type and / or quantity of detergent used.

Claims (15)

  A method of controlling one or more parameters of a washing process, characterized in that the value of the parameter (s) is set according to a function dependent on at least the type and / or amount of detergent used in said washing process.   2. Servo-control method according to claim 1, characterized in that it comprises a step of determining the type and / or amount of detergent used in said washing process, said determining step comprising a step of measuring the conductivity of a detergent bath.   3. Control method according to claim 2, characterized in that said step of determining the type and / or amount of detergent used further comprises a step of calculating a ratio of a predetermined value (Y) the conductivity associated with the feed water and the measured value (Y ') of said conductivity of a detergent bath, and a step of comparing said ratio with one or more predetermined threshold values.   4. Servo-control method according to one of claims 2 to 3, characterized in that said step of measuring the conductivity of a detergent bath is carried out after mixing said detergent bath.   5. Servo-control method according to one of claims 1 to 4, characterized in that the value of the parameter or parameters of a textile washing process is set according to a further dependent function of at least the type of textile and the weight of textile to be washed.   6. Control method according to one of claims 1 to 5, characterized in that one of said parameters is a duration (D1, D2) of intermediate spin in a textile washing process.   7. A servo-control method according to claim 6, characterized in that said duration varies between a minimum threshold value for a textile weight to be washed less than 2 kg and a fast-dissolving detergent and a maximum threshold value for a weight of washing textile greater than 4 kg and a slow dissolving detergent.   8. Servo control method according to one of claims 1 to 7, characterized in that one of said parameters is a maximum speed (V) of rotation of a washing drum (12) adapted to contain textile.   9. Servo-control method according to claim 8, characterized in that the maximum speed (V) of rotation of the drum (12) varies between a minimum threshold value for a weight of washing textile less than 2 kg and a detergent rapidly dissolving and a maximum threshold value for a washing textile weight of more than 4 kg and a slow dissolving detergent.   10. Servo control method according to one of claims 1 to 9, characterized in that said parameters are the number of rinsing phases of a washing process and the respective duration of said rinsing phases.   11. Servo-control method according to one of claims 1 to 10, characterized in that it further comprises the following steps: -methical measurement of the conductivity of a rinsing bath during a rinsing phase; comparing said periodically measured conductivity values (Y '); and determining the end of said rinsing phase when at least two consecutive conductivity measurements are substantially identical.   12. Servo control method according to one of claims 1 to 11, characterized in that it comprises the following steps: - measuring the conductivity of a rinsing bath during a rinsing phase; comparing said measured value (Y ') of conductivity with a predetermined value (Y) of the conductivity associated with the feed water; and carrying out a final rinsing phase when said measured conductivity value (Y ') is substantially equal to the predetermined value (Y) of the conductivity of the feed water.   13. Washing machine adapted to implement a servo process according to one of claims 1 to 12, characterized in that it comprises means for determining the type and / or amount of detergent.   14. Washing machine according to claim 13, characterized in that it further comprises means for determining the weight of textile 5 to be washed and means for determining the type of textile.   15. Washing machine according to one of claims 13 or 14, characterized in that said means for determining the type of detergent are adapted to select said detergent from a set of detergents comprising at least detergents in the form of liquid or compacted or dispersed powder.