WO2015004611A1

WO2015004611A1 - Method for controlling a household appliance adapted to carry out at least one laundry drying cycle, and household appliance operating according to said controlling method

Info

Publication number: WO2015004611A1
Application number: PCT/IB2014/062965
Authority: WO
Inventors: Giuseppina Pia Potena; Luca Bossi; Giuseppe PASSARETTI; Adriana VOTO; Aldo Liberatore
Original assignee: Indesit Company S.P.A.
Priority date: 2013-07-12
Filing date: 2014-07-09
Publication date: 2015-01-15
Also published as: ITTO20130586A1; EP3019658A1; EP3019658B1

Abstract

Method for controlling a household appliance (1) adapted to carry out a laundry drying cycle as well as household appliance (1) for implementing same, wherein said household appliance (1) is equipped with a drum (10) into which laundry to be dried is loaded and, wherein the method comprises the steps of: starting a drying cycle; during the execution of said drying cycle, determining a first parameter (P1) as a function of at least one of: time elapsed since the cycle was started, temperature of the drying air, humidity of said laundry; making a first comparison between said first parameter (P1) and a predetermined first threshold (Ref1); based on said first comparison, generating a notification signal (NS) and interrupting said drying cycle; resuming said drying cycle; determining a second parameter (P2) as a function of at least one of: time elapsed since the cycle was started or resumed, temperature of the drying air, humidity of said laundry; making a second comparison between said second parameter (P2) and a predetermined second threshold (Ref2) and, based on said second comparison, ending said drying cycle.

Description

" METHOD FOR CONTROLLING A HOUSEHOLD APPLIANCE ADAPTED TO CARRY OUT AT LEAST ONE LAUNDRY DRYING CYCLE, AND HOUSEHOLD APPLIANCE OPERATING ACCORDING TO SAID CONTROLLING METHOD " DESCRIPTION

The present invention relates to a method for controlling a household appliance adapted to carry out at least one laundry drying cycle.

The present invention further relates to a household appliance adapted to perform a laundry drying cycle and operating according to said control method.

As known, drying machines and some washing machines are adapted to perform drying cycles, by means of suitable drying systems.

Drying cycles can be selected by the user according to the type of loaded clothes and to the desired drying level .

This selection is performed by means of an appropriate user interface, comprising for example a keyboard and/or a display.

During the execution of drying cycle, the machine performs periodic checks on parameters representing the drying degree of the clothes loaded in the drum.

When the desired drying level, determined according to the drying program initially selected by user, has been reached, the appliance finishes the cycle and enters a condition of substantial deactivation.

Known type of drying cycles briefly described above are unsatisfactory and inadequate in some circumstances wherein, for example, cloths made of different fabrics are loaded in the machine (e.g. cotton and synthetic) or when it is desirable to have different drying levels for cloths made of the same fabric. As a way of example consider, in this regard, shirts made of cotton, which should remain slightly wet for a satisfactory ironing, and towels also made in cotton, which must instead be dried in the best possible way.

Object of the present invention is thus to provide a method and an appliance that allow to perform drying operations in an effective and versatile way.

This and other objects are substantially achieved by a method and equipment as described in the appended claims.

An idea underlying the present invention provides for the execution of a drying cycle in several stages, wherein at least an intermediate level and at least a final level are set: depending on certain parameters representative of the cloths drying level, comprising for example, the time elapsed since the beginning of the cycle and/or the drying air temperature and/or the clothes humidity, the drying cycle is divided into two or more phases. At the end of each phase the user will have the possibility to extract from the drum those clothes which, at that particular stage, have reached the required drying level.

In particular, according to a first aspect the invention relates to a method for controlling a household appliance adapted to perform at least one clothes drying cycle, said appliance being provided with a drum in which clothes to be dried are loaded, said method comprising: a. starting a drying cycle;

b. during the execution of said drying cycle, determining a first parameter as a function of at least one of: time elapsed since the cycle was started, temperature of the drying air, humidity of said laundry; c. making a first comparison between said first parameter and a predetermined first threshold; d. as a function of on said first comparison, interrupting said drying cycle and generating a notification signal;

e. resuming said drying cycle;

f. determining a second parameter as a function of at least one of: time elapsed since the cycle was started or resumed, temperature of the drying air, humidity of said laundry;

g. making a second comparison between said second parameter and a predetermined second threshold;

h. as a function of said second comparison, ending said drying cycle.

According to a further aspect, the invention relates To a household appliance configured to carry out at least one laundry drying cycle, comprising:

a. a drum;

b. a drying system for drying laundry items loaded in said drum;

c. a processing unit associated with said drum and with said drying system and configured for:

^ activating said drying system in order to start a drying cycle;

during the execution of said drying cycle, determining a first parameter as a function of at least one of: time elapsed since the cycle was started, temperature of the drying air, humidity of the laundry;

making a first comparison between said first parameter and a predetermined first threshold;

as a function of said first comparison, generating a notification signal and interrupting said drying cycle;

^ resuming said drying cycle;

^ determining a second parameter as a function of at least one of: time elapsed since the cycle was started or resumed, temperature of the drying air, moisture of said laundry;

making a second comparison between said second parameter and a predetermined second threshold;

^ as a function of said second comparison, ending said drying cycle.

In accordance with one or more of the above aspects, the invention comprises one or more of the optional features described below.

Preferably said first and second parameter are a same parameter, said first and second threshold being representative of said different values of the same parameter .

Preferably said first and second threshold are representative of different levels of drying of clothes made of a same material.

Preferably said first and second threshold levels are representative of drying of clothes made of different materials.

Preferably said method further comprises receiving an input setting signal of a drying cycle at multiple levels.

Preferably said processing unit is also configured to receive an input setting signal of a drying cycle at multiple levels.

Preferably said drying cycle is resumed after input of a consent signal by user.

Preferably, drying cycle is resumed after a predetermined time if an access door to said drum is not opened.

Further characteristics and advantages will appear from a description of a preferred and not exclusive embodiment of the invention. This description is thereafter provided with reference to the accompanying drawings, also having purely a purpose of example and therefore not limiting, wherein :

- Figure 1 shows a block diagram of an appliance according to the present invention;

Figure 2 shows a flow diagram representative of the method according to the present invention;

- Figure 3 shows a representative diagram of a possible operation of equipment of Figure 1 when controlled by a method according to flow diagram of Figure 2.

Drawings illustrate different aspects and embodiments of the present invention and, where appropriate, structures, components, materials and/or similar elements in different drawings are indicated by the same reference numerals.

[DE TAILED DESCRIPTION OF THE INVENTION ]

With reference to the accompanying drawings, 1 denotes in its entirety a household appliance adapted to perform at least one clothes drying cycle.

The appliance 1 may be a dryer, or a washing machine having also a drying functionality.

Both these types of equipment are well known themselves and will not therefore be described in detail.

Appliance 1 (schematically represented in Figure 1) comprises a drum 10 wherein clothes are loaded which should be subjected to a drying operation. The basket 10 is advantageously associated with a door 20 movable between an open condition, wherein access into drum 10 is allowed (for example, for clothes loading or removing) and a closing condition, wherein it prevents access into drum 10 itself.

Appliance 1 further comprises a drying system 30 associated with drum 10 and configured to promote drying of clothes loaded in the same. Preferably drying system 30 includes means for moving drum 10 in rotation, means adapted to promote the circulation of drying air through the drum 10 itself and drying air heating means. Heating means may comprise, for example, an electrical resistance or a heat exchanger being part of a heat pump circuit.

Appliance 1 also comprises a processing unit 40 associated with drying system 30 to manage drying process in an appropriate way.

By way of example, processing unit 40 may be disposed on an electronic card, or can also be distributed on two or more electronic cards.

In one embodiment, processing unit 40 may be constituted by or comprise an electro-mechanical timer.

Control method implemented by processing unit 40 is schematically represented by flow diagram of Figure 2.

This process preferably allows the user to enter a command for setting a drying cycle at multiple levels (step 100) .

This command can be entered through a suitable user's interface (not shown) , comprising for example a keyboard and/or a display, the latter preferably of touch-screen type .

By means of said user's interface a signal for drying cycle execution at multiple levels is then sent to processing unit 40.

Processing unit 40 then provides to activate drying system 30 to start a drying cycle.

During said drying cycle execution, processing unit 40 determines a first parameter PI as a function of at least one of: time elapsed since cycle beginning, drying air temperature, clothes humidity.

Time elapsed since drying cycle beginning can be determined by processing unit 40 via its own internal time reference .

Drying air temperature can be determined by a suitable sensor, positioned in a duct for feeding air to drum, or in an air outlet pipe from drum, or even inside drum 10.

Similarly, humidity of clothes contained within drum 10 can be determined by a suitable sensor, positioned within drum 10 or otherwise associated with the latter.

Note that quantities of interest mentioned above can be determined by means of both "physical" and so-called "virtual" sensors; "virtual sensor" of a given physical quantity of interest to be determined comprises "physical" sensor means of one or more physical quantities actually measured and processing means which, by applying a predetermined algorithm to actual measurements, allow to obtain "virtual" measures of physical quantity of interest .

It is also expected that values mentioned above can not be detected directly, but indirectly derived from observation of other characteristic quantities of appliance operativity 1.

First parameter PI is then calculated, as said, a function of one or more between time elapsed since drying cycle beginning, drying air temperature, clothes humidity.

Processing unit 40 then provides to perform a first comparison (step 110) between first parameter PI and a predetermined first threshold Refl.

Advantageously, calculation of first parameter PI and/or relative comparison with first threshold Refl can be performed in a periodic or substantially continuous way .

First threshold Refl is representative of a first intermediate drying level, wherein the user may be given the opportunity to extract some items, leaving others in the drum to continue or to finish drying cycle.

According to the first comparison processing unit 40 can interrupt drying cycle and generate a notification signal NS .

In particular, if the first threshold Refl has not yet been reached by the first parameter PI, then the drying cycle is continued (step 120) .

When, instead, the first parameter PI reaches or exceeds the first threshold Refl, the notification signal NS is generated and the drying cycle is interrupted.

Preferably, after verifying first threshold Refl achievement by first parameter PI and before stopping drying cycle, a cooling phase or cool tumble (step 130) is carried out, after which the signal notification NS (step 140) is generated and the cycle interrupts.

The cooling phase consists in performing a movement of drum with drying air circulation, being however aforementioned heating means of drying air disabled, so as to produce a gradual cooling of drum and clothes contained therein, to allow its extraction by the user preventing the user from being exposed to the same risk of contact with bodies at high temperatures.

Notification signal NS can be an acoustic and/or visual alarm; this signal has the task to indicate to the user that cycle first phase is over and that it is therefore possible to extract some of loaded clothes.

The user then has the possibility to pull out clothes from the drum 10 which are considered to be at a required drying level at the end of first phase.

In one embodiment, before resuming, processing unit 40 waits until the user enters a permission signal (step 150) .

In practice, once alerted by signal notification NS, the user can open door 20, extract part of the clothes, close door 20 itself and provide a consensus (for example, by the above user interface) to drying cycle resuming.

In addition or alternatively, processing unit 40 keeps appliance 1, and in particular drying system 30, in a stand-by state for a predetermined time. If no door opening 20 is detected in that span of time, drying cycle is resumed.

Processing unit 40 then provides to re-activate drying system 30 to resume drying cycle.

Block 160 of Figure 2 represents control method implementation until the substantial conclusion of the same.

After resuming, a second parameter P2 is determined as a function of at least one of: time elapsed since cycle beginning or resuming beginning, drying air temperature, clothes humidity.

Detection can be advantageously performed periodically or with substantial continuity.

Second parameter P2 may coincide with first parameter PI, that is, present the same functional relationship with respect to time elapsed since cycle beginning or resuming beginning and/or with respect to drying air temperature and/or with respect clothes humidity.

In practice, the first and second parameters PI, P2 can be determined/calculated according to the same algorithm and, being determined/calculated in different circumstances, they may assume different values.

In a different embodiment, first and second parameters PI, P2 are calculated in a different way from one another, i.e. as a function of different variables and/or as a function of different algorithms.

Processing unit 40 then provides to make a second comparison of second parameter P2 and a second predetermined threshold Ref2.

This second threshold Ref2 is representative of a second drying level of clothes present in drum 10.

Conveniently, second threshold Ref2 represents drying level at which cycle is ended (step 170) .

In practice, the processing unit 40 compares, periodically or continuously, second parameter P2 to relative threshold Ref2: when threshold is reached, the processing unit 40 then provides to perform a cooling or cool tumble step and, at the end of the latter, to turn off drying system 30 completely and to drive the whole appliance 1 in rest condition/deactivation .

In correspondence to cycle conclusion, processing unit 40 may generate a further alarm, for example of acoustic and/or visual type, in order to warn the user that the machine has completed its operations.

Preferably first and second threshold Refl, Ref are representative of different drying levels of clothes substantially made of a same material.

Consider, in this regard, shirts and towels made of cotton: the first threshold Refl can allow the user to extract shirts to a certain level of humidity (to facilitate subsequent ironing) , while the second threshold Ref2 represents drying cycle actual conclusion, wherein towels can be extracted as completely dry.

In a different embodiment, first and second threshold Refl, Ref2 represent instead desired drying levels of clothes made of different materials.

Consider, in this regard, a load composed of clothes made of synthetic material and cotton: the first threshold Refl represents drying level at which cloths made of synthetic material (which takes less time to dry) can be extracted from drum, while the second threshold Ref2 represents complete drying level of cotton cloths.

Note that, although in the present description only an intermediate level has been taken into account, defined by the aforementioned first threshold Refl, it is possible that cycle may also provide for a greater number of intermediate thresholds, before arriving at its conclusion. Operations which processing unit 40 can perform with respect to each of said intermediate thresholds are quite similar to those described above with reference to the first threshold Refl.

Figure 3 shows schematically an example of equipment 1 operation.

X-axis represents time, while on ordinate axis parameters PI, P2, relative thresholds Refl, Ref2 and temperature trend Temp measured in an air outlet conduit from drum 10 are presented.

The parameters PI, P2 are representative, as mentioned, of drying level of clothes within drum 10.

As it can be seen, in the cycle initial phase, until the first parameter PI is less than the first threshold Refl, the heating means of the drying system 30 remain active and the temperature Temp within drum 10 continues to grow.

In correspondence to the first threshold Refl achievement by the first parameter PI, a cooling step is performed wherein the drying system 30 heating means are deactivated, and the temperature Temp then undergoes a decrease .

At the end of this cooling step, the drying cycle is interrupted and the user can access the drum and remove clothes for which the first part of drying cycle is sufficient .

As drying system 30 is re-activated, the temperature Temp within drum starts to grow, until the second parameter P2 reaches the second threshold Ref2.

At this point, a new cooling phase is performed wherein heating means of drying system 30 are deactivated, at the end of which the whole machine turns off and drying cycle is complete; the user can then remove the remaining clothes from drum 10.

Claims

1. A method for controlling a household appliance adapted to carry out at least one laundry drying cycle, said appliance (1) being equipped with a drum (10) into which laundry to be dried is loaded, said method comprising :

a. starting a drying cycle;

b. during the execution of said drying cycle, determining a first parameter (PI) as a function of at least one of: time elapsed since the cycle was started, temperature of the drying air, humidity of said laundry; c. making a first comparison between said first parameter (PI) and a predetermined first threshold (Refl) ;

d. based on said first comparison, generating a notification signal (NS) and interrupting said drying cycle ;

e. resuming said drying cycle;

f. determining a second parameter (P2) as a function of at least one of: time elapsed since the cycle was started or resumed, temperature of the drying air, humidity of said laundry;

g. making a second comparison between said second parameter (P2) and a predetermined second threshold (Ref2) ;

h. based on said second comparison, ending said drying cycle .

2. A method according to claim 1, wherein said first and second parameters (PI, P2) are one same parameter, said first and second thresholds (Refl, Ref2) being representative of different values of said same parameter.

3. A method according to claim 1 or 2, wherein said first and second thresholds (Refl, Ref2) are representative of different drying levels of laundry items made of one same material.

4. A method according to claim 1 or 2, wherein said first and second thresholds (Refl, Ref2) are representative of drying levels of laundry items made of different materials.

5. A method according to any one of the preceding claims, further comprising receiving an input signal for setting a multi-level drying cycle.

6. A method according to any one of the preceding claims, wherein said drying cycle is resumed after the user has issued an enable signal.

7. A method according to any one of claims 1 to 5, wherein said drying cycle is resumed after a predetermined time, if a door (20) allowing access to said drum (10) is not opened.

8. A method according to any one of the preceding claims, wherein, after having verified that said first parameter (PI) has reached said first threshold (Refl) and before interrupting said drying cycle, a step of cooling said laundry is carried out.

9. A household appliance configured to carry out at least one laundry drying cycle, comprising:

a . a drum (10) ;

b. a drying system (30) for drying laundry items loaded in said drum (10);

c. a processing unit (40) associated with said drying system (30) and configured for:

^ activating said drying system (30) in order to start a drying cycle;

during the execution of said drying cycle, determining a first parameter (PI) as a function of at least one of: time elapsed since the cycle was started, temperature of the drying air, humidity of said laundry; making a first comparison between said first parameter (PI) and a predetermined first threshold (Refl) ;

based on said first comparison, generating a notification signal (NS) and interrupting said drying cycle ;

^ resuming said drying cycle;

^ determining a second parameter (P2) as a function of at least one of: time elapsed since the cycle was started or resumed, temperature of the drying air, humidity of said laundry;

making a second comparison between said second parameter (P2) and a predetermined second threshold (Ref2) ;

^ based on said second comparison, ending said drying cycle.

10. An appliance according to claim 9, wherein said first and second parameters (PI, P2) are one same parameter, said first and second thresholds (Refl, Ref2) being representative of different values of said same parameter.

11. An appliance according to claim 9 or 10, wherein said first and second thresholds (Refl, Ref2) are representative of different drying levels of laundry items made of one same material.

12. An appliance according to claim 9 or 10, wherein said first and second thresholds (Refl, Ref2) are representative of drying levels of laundry items made of different materials.

13. An appliance according to any one of claims 9 to 12, wherein said processing unit (40) is also configured to receive an input signal for setting a multi-level drying cycle .

14. An appliance according to any one of claims 9 to 13, wherein said processing unit (40) is also configured to resume said drying cycle after a user has issued an enable signal .

15. An appliance according to any one of claims 9 to 13, wherein said processing unit (40) is also configured to resume said drying cycle after a predetermined time, if a door (20) allowing access to said drum (10) is not opened.

16. An appliance according to any one of claims 9 to 15, wherein said processing unit (40), after having verified that said first parameter (PI) has reached said first threshold (Refl) and before interrupting said drying cycle, controls said drying system (30), in particular means for driving the drum (10) and means adapted to promote the circulation of drying air in said drum (10) included in said drying system (30), in order to carry out a step of cooling said laundry.