ITTO20130003A1 - PROCEDURE FOR CHECKING THE FILLING WITH WATER OF A WATER-CONDUCTED HOUSEHOLD APPLIANCE - Google Patents

Description

â € œProcedure for checking the water filling of a water-conducting applianceâ €,

TEXT OF THE DESCRIPTION

Field of invention

The present invention relates to water-conducting household appliances in general, such as dishwashing machines and washing machines, and has been developed with particular reference to the methods for filling water into such household appliances.

Prior art

Water-conducting household appliances such as dishwashers and washing machines have a treatment container designed to receive items to be washed. In general, a treatment program of such a household appliance comprises a plurality of operating phases, at least some of which are carried out with water, such as pre-washing, washing, rinsing, soaking phases. Each of these phases involves the loading of water into the treatment container, the execution of a respective part of the treatment and then the discharge of the liquid used. In some cases, after an initial filling of water into the treatment container, the control system commands one or more top-ups to be carried out during the same program phase.

The water is usually taken from a domestic water network and its dosage is carried out by means of a filling sensor, usually a pneumatic sensor (such as a pressure switch), a volumetric sensor (such as a impeller flow) or an optical type sensor (such as a device including an emitter and a light receiver).

It is possible that, for various reasons, the filling sensor is not working correctly and / or not providing a respective signal to the machine control system. EP 2276388 A discloses a procedure for checking the filling of a water-conduction household appliance, according to which the possible total failure state of a filling sensor is detected using a washing pump and evaluating the characteristic curve of range of the latter.

Purpose and summary of the invention

The present invention proposes to carry out an alternative procedure to the one known from EP 2276388 A, to be used in the event of the absence of a signal from a sensor designed to detect the supply of water to the treatment container, but simpler and more immediate. intervention. An auxiliary object of the invention is to provide a process which allows to control the filling of water in a water-conducting household appliance even in the presence of anomalous signals from a sensor of the aforesaid type.

One or more of these objects is achieved, according to the present invention, by a process for controlling the filling of water in a water-conducting household appliance having the characteristics indicated in claim 1. Preferred characteristics of the invention are indicated in the sub-claims. The claims form an integral part of the technical teaching provided in relation to the invention.

Brief description of the drawings

Further objects, characteristics and advantages of the present invention will become clear from the following description, made with reference to the attached drawings, provided purely by way of non-limiting example, in which:

- Figure 1 is a schematic sectional representation of a dishwasher which implements the process according to the present invention.

Description of preferred embodiments of the invention

The reference to "an embodiment" within this description indicates that a particular configuration, structure, or feature described in relation to the embodiment is included in at least one embodiment. Thus, the terms â € œin one embodimentâ € and the like, present in different parts within this description, are not necessarily all referring to the same embodiment. Furthermore, the particular configurations, structures or features can be combined in any suitable way in one or more embodiments. The references used below are for convenience only and do not define the scope of protection or the scope of the forms of implementation.

It should also be noted that in the following of the present description only the elements useful for understanding the invention will be described, assuming that the household appliance according to the invention includes all the elements known per se for its operation, such as its possible external cabinet, a user interface, a water heating resistance, a dispenser of washing agents, etc.

Figure 1 schematically represents a water-conduction household appliance according to a possible embodiment of the present invention, represented here by a domestic dishwasher, illustrated limitedly to the parts of immediate interest for understanding the present invention.

The machine 1 has a structure 2 which comprises a treatment container, here represented by a washing tank 3, below which a housing space is defined in which various functional components of the machine 1 are positioned, including a pump washing 4 and a well 5 for collecting the water, as well as other components not shown in the figure for reasons of greater clarity of the drawing. The washing tank 3, of a generally known concept, comprises an upper wall, a lower wall and four side walls, one of which - the front wall - is constituted by an internal shell of the machine door, not shown here (the so-called â € œ counter doorâ €). Inside the tank 3 there is at least one basket for dishes: in the example shown, the machine 1 has a lower basket 6 and an upper basket 7, intended to contain respective loads of dishes.

The machine 1 has a sprinkler system, which includes at least one sprinkler member, for sprinkling the dishes contained in a basket with water. In the case shown, since the machine has two baskets, the sprinkler system includes two sprinkler members 8 and 9, to sprinkle the dishes contained in the baskets 6 and 7, respectively, with water. The sprinkler system is powered by means of the washing pump 4 and a known device 10 for alternating power supply of sprinklers 8 and 9; the device 10 has at least one inlet, connected to the delivery of the pump 4, and at least two outlets, connected by means of ducts 10a and 10b to the sprinklers 8 and 9, respectively.

The machine 1 has a supply duct 11, for connection to a domestic water network, on which there is a controllable filling valve 12, for example a solenoid valve. The machine also comprises a sensor device, hereinafter also referred to as the filling sensor, designed to detect the water supply into the tank 3 from the water mains, or to generate signals representative of a level of the filled water or its volume. In a preferred embodiment, such as the one shown, the aforesaid sensor device is a sensor of the volumetric type with impeller, indicated by 13. Sensors of this type are well known in the field. For example, refer to EP 0599341 for the description of a flow meter of this type, suitable for use on machine 1.

In general terms, such a sensor includes an impeller rotated by the fluid, said impeller integrating or having associated one or more excitation elements; a stationary part of the sensor then includes a detector, adapted to be excited by the excitation elements movable with the impeller. The excitation element or elements may be of the magnetic type, in which case the detector is a magnetic field detector; alternatively, the detection of the rotation of the impeller can be performed by means of an optical detector, in which case a part of the same impeller realizes the excitation means.

Very briefly, a fluid entering the sensor device causes the rotation of the impeller, and the number of revolutions of the latter - proportional to the volume of fluid entering - is detected by means of the aforementioned detector. In the example, the impeller filling sensor 13 is operatively arranged between the duct 11 and a duct 14 for feeding the water into the tank 3.

Again in the figure, 15 indicates a visual signaling device, such as a warning light or a display placed on a control panel of the machine. 16 indicates an acoustic signaling device, such as a buzzer. With 17 a machine control system is indicated, preferably including a microprocessor control unit, to which memory means are associated which contain program information and data for the execution of a plurality of possible programs treatments that can be carried out by the machine 1. The control system 17 also includes means for selecting and starting the aforementioned programs, not shown.

In normal operation, a user - after loading the dishes into the tank 3 of the machine 1 - selects a desired treatment program and starts it, for example by pressing a specific button. At the start of each of the water treatment phases foreseen by the program, the system 17 commands the opening of the valve 12, which is kept open until the system itself detects, through the filling sensor 13, the filling in the tank 3 of a certain volume of liquid. In the meantime, or later, the system 17 commands the start-up of the washing pump 4, after any switching of the device 10, if required. The water loaded into the tank reaches one or both sprinklers 8, 9 and is sprayed on the contents of the baskets 6, 7. The water then falls on the bottom of the tank, to flow back into the well 5, from where it is put back into circulation by means of pump 4. At the end of the treatment phase, the control system commands the stop of the wash pump 4 and the start of a drain pump, not shown. Once the evacuation of the water previously used has been completed, the drain pump is stopped and the system 17 commands a new opening of the valve 12, in order to load the volume of water necessary for the execution of a subsequent phase of the treatment program.

As we have seen, after the selection and start of a treatment program, in the phase of loading water from the external water mains, the control system 17 monitors a return signal from the filling sensor 13 and uses it to control closing the valve 12.

According to the invention, in the absence of any signal from the filling sensor 13 until the end of a first period of time after the opening of the filling valve 12, the control system 17 activates a signal, by means of at least one between the visual signaling device 15 and the acoustic signaling device 16. In a preferred embodiment, both signals are activated. In this way, the user is immediately notified in relation to a possible malfunction of the machine 1, due to a failure of its filling sensor 13 or to an anomalous condition of the water supply network, such as the closing condition of a tap. connection of the machine or the absence of water in the network.

The aforementioned first period of time preferably has a relatively short predetermined duration, indicatively not exceeding one minute and preferably comprised between 10 and 30 seconds, most preferably about 15 seconds. It should be noted that the first water filling of a treatment program generally takes place a few moments after the start of the program itself: therefore, according to a preferred embodiment of the invention, the anomaly is signaled in any case after a relatively short time after starting the program, when the user is presumably still near the machine 1.

Again in accordance with the invention, in the absence of a signal from the filling sensor 13 even up to the end of a second period of time, subsequent to the aforementioned first period of time, the control system 17 commands the end of the treatment program. Preferably, during the second lapse of time the system 17, in addition to monitoring the filling sensor 13, keeps active the acoustic signal and / or the acoustic signal generated by means of the device 15 and / or the device 16.

In a preferred embodiment, the second period of time has a predetermined duration greater than the first period of time, indicatively not exceeding five minutes, preferably between 200 and 250 seconds, most preferably about 220 seconds. In this way, after having signaled to the user with certainty the existence of an anomaly in the course of water filling, the user himself is offered a sufficiently long time (preferably at least 2 - 3 minutes) to perform a € ™ any corrective action. In other words, even after the start of the anomaly signaling, the system 17 remains in a waiting condition for a certain period, continuing to monitor the status of the filling sensor 13: if during this period - the aforementioned second time lapse - the signal from sensor 13 occurs, the treatment program can continue in the usual way; such a case may occur, for example, if the tap of the connection fitting of the machine 1, initially closed, is opened by the user after the start of the visual and / or acoustic signal.

Conversely, in the case of a persistent absence of the signal from the sensor 13 for the entire second period of time, the program is terminated by the control system 17, which then goes into a quiescent state. Of course, the end of the program implies the closing of the loading valve 12. Preferably, but not necessarily, the end of the program also implies the deactivation of the signaling means 15, 16: in a preferred embodiment, however, before ending the program, the control system 17 generates an error code which is in any case highlighted visually and / or acoustically upon subsequent use of the machine. From what has been described it can be seen that, after a relatively short time from the opening of the filling valve 12 (between 210 and 270 seconds after the opening of the valve 12, in the example provided) the program is in any case terminated, if the absence of signal from sensor 13 persists. As mentioned, the absence of signal from sensor 13 can possibly be remedied during the second period of time. For example, this may be the case - already mentioned - of an initially closed tap of the connection of the machine to the water mains, or the case of a momentary jamming of the impeller of the sensor 13, due to any reason. The absence of a signal that persists for the entire second period of time is instead indicative of circumstances such as a total absence of water in the water network, or a failure of the sensor 13 of such significance as not to enable the emission of any signal , or even the accidental disconnection of one of its connectors.

It is also possible that the filling sensor 13 generates a signal, but that this signal cannot be interpreted or used effectively by the control system 17 for the purpose of dosing the volume of water necessary for the operation of the machine.

For example, in a common impeller sensor 13 the number of output signal pulses is substantially proportional to the volume of water that passes through the sensor itself. Given that domestic water networks have a substantially constant flow rate, the number of pulses generated by the sensor in a unit of time is on average included in a determined range or field of values, which can be stored in the control system 17 (yes note, among other things, that often the filling solenoid valves of household appliances or the impeller meters themselves include a flow or pressure regulator, also having the function of stabilizing the flow rate of the water in transit; see for example EP 1456576 A ). However, it is possible that, due to a sensor failure, the number of impulses in the unit of time does not fall within the aforementioned range: for example, think of a sensor 13 whose impeller, due to damage to its rotation or of the latterâ € ™ s supports, rotates slowly in jerks or conversely rotates too quickly, or even due to a malfunction of the impeller rotation detector.

In a preferred embodiment of the invention, in the presence of such an â € œanomalâ € signal from sensor 13 - that is, a signal that is not compatible with a stored value or range of reference values, or in any case not interpretable or not usable effectively by the system 17 to determine the volume of water that is loaded into the tank - the control system 17 keeps the filling valve 12 open until a predetermined period of time has elapsed, hereinafter also defined for simplicity as a third period of time, for example comprised between 40 and 80 seconds, preferably about 60 seconds.

After the third period of time has elapsed, the control system 17 commands the closing of the loading valve 12 and activates the motor of the washing pump 4 at a first predetermined speed, preferably a speed lower than the normal washing speed. The fact that the sensor 13 generates a signal, however anomalous, should be indicative of the fact that water is still entering the appliance: the activation of the pump is essentially aimed at verifying the actual presence of water in the tub 3.

The system 17 monitors a signal characteristic of the operation of the motor of the pump 4 and evaluates it, comparing it with a first threshold value. If the characteristic signal does not reach and / or does not exceed the first threshold value, the control system 17 commands a new opening of the valve 12 and then evaluates again the characteristic signal of the operation of the motor of the pump 4: when this characteristic signal reaches the first threshold value, the system 17 commands the closing of the valve 12.

The aforesaid characteristic signal can be for example the quantity of current absorbed by the motor of the pump 4, which is representative of its characteristic curve, and therefore of its load. Obviously, there is nothing to prevent the monitoring of other controllable quantities of the motor, representative of the characteristic curve or of the pump load. In one embodiment, the motor of the pump 4 is an electronically controlled brushless motor, that is a speed-controllable permanent magnet motor.

It will be appreciated that, since the characteristics of the hydraulic circuit of the machine 1 are known, through experimental tests it is possible to determine, for various speeds of the motor of the pump 4 and for the relative values of current absorption, corresponding volumes or range of volumes or levels of water in the tub. This information is suitably coded in the memory means of the control system 17 and can be used for the purposes of implementing the procedure described here. The activation phase of the pump at the aforementioned first speed is essentially aimed at verifying, by the control system 17, that a volume or level of water is actually loaded into the tank - even if minimal - without thereby bringing the pump itself at its normal washing speed.

In one embodiment it is envisaged that, if after the aforementioned new opening of the valve 12, the current absorption by the motor of the pump 4 (or other monitored characteristic signal) does not reach and / or exceed the aforementioned first value within a further predetermined period of time, the control system 17 ends the treatment program (and therefore the closure of the valve 12), after generating at least one signal for the user, via the device 15 and / or the device 16, and / or after generating an error code to be highlighted when the machine is subsequently used. Such a circumstance can be considered indicative of the fact that the flow of water entering the machine 1 from the water mains is very low, such as to involve excessively long times for reaching the volume of water necessary for the execution of a treatment phase. . The aforesaid further predetermined period of time can be, for example, between 60 and 120 seconds, preferably between 40 and 80 seconds, and most preferably about 60 seconds.

After the closure of the valve 12 which occurs after the aforementioned third period of time, or in any case after the aforementioned first threshold value has been reached, the control system 17 brings the motor of the pump 4 to a second speed, preferably greater than the first speed, most preferably at the washing speed. Subsequently, the system 17 evaluates again the current absorption (or other characteristic signal) of the motor of the pump 4: if this signal reaches and / or exceeds a second threshold value, the system 17 commands the continuation of the treatment in the usual way. Otherwise, the system 17 commands a new opening of the valve 12, evaluates again the absorption (or other characteristic signal) and when this signal reaches the second threshold value - indicative of the achievement of at least one volume or level of water in tank suitable for the execution of the treatment - the control system 17 commands the closure of the valve 12 and controls the continuation of the treatment program, in the usual way.

In fact, it will be appreciated that, on the basis of the experimental data stored in the control system 17, the latter is able to know what is the value or range of current absorption values which, at the washing speed of the pump motor 4 , corresponds to a level of water in the tank considered sufficient for carrying out an efficient treatment.

From the above description the characteristics of the present invention are clear, as well as its advantages, mainly represented by the possibility of managing in a simple and rapid way the case of absence of any signal from a filling sensor of the household appliance, and possibly to manage also the case of generation of anomalous signals with respect to usual values.

It is clear that numerous variants are possible for the person skilled in the art to the process described as an example, without thereby departing from the scope of the invention as defined in the attached claims.

The invention has been exemplified in relation to a water-conduction household appliance using an impeller volumetric meter, but the invention can also be used in the case of other types of filling sensors, such as for example pneumatic sensors or optical sensors.

It is also known that some washing machines are equipped with an internal tank, aimed at allowing the reuse of at least part of the washing liquid already used for a treatment: the filling sensor provided according to the invention can be a sensor arranged on a supply line that extends from such a tank inside the appliance to its treatment container.

Claims (13)

CLAIMS 1. A process for controlling the water filling of a water-conducting household appliance (1) having a control system (17), such as a dishwashing machine or a washing machine, in which, after starting a appliance treatment program (1): a) the control system (17) commands the opening of a filling valve (12) placed on a line (11, 14) for the supply of water to a treatment container (3) of the household appliance (1); b) the control system (17) monitors a sensor (13) designed to detect the water supply to the treatment container (3); c) in the absence of a signal from the sensor (13) until the end of a first period of time after the opening of the filling valve (12), the control system (17) commands the activation of a signal ( 15, 16); And d) in the absence of a signal from the sensor (13) even up to the end of a second period of time following the first period of time, the control system (17) commands the end of the treatment program. The process according to claim 1, wherein the first period of time does not exceed one minute and is preferably comprised between 10 and 30 seconds. The method according to claim 1 or claim 2, wherein the second time span is not more than five minutes and is preferably between 200 and 250 seconds. The method according to any one of the preceding claims, in which the end of the treatment program is commanded between 210 and 270 seconds after the opening of the loading valve (12). 5. The method according to claim 1, in which, after steps a) and b), and in the presence of a signal from the sensor (13), the control system evaluates whether this signal is compatible with a value or a range of predetermined values and, if positive, controls the continuation of the treatment program. 6. The process according to claim 1, in which, after steps a) and b), and in the presence of a signal from the sensor (13), the control system evaluates whether this signal can be used for the purposes of dosing the water and, if not: - the control system (17) keeps the loading valve (12) open until a predetermined period of time has elapsed; - after the expiry of the predetermined period of time, the control system (17) commands the closing of the loading valve (12) and commands the motor of a treatment pump (4) at a first speed; - the control system (17) evaluates a characteristic signal of the operation of the pump motor (4) e - if the signal characteristic of the operation of the pump motor (4) reaches or exceeds a first threshold value, the control system (17) commands the pump motor (4) at a second speed, preferably higher than the first speed, or - if the signal characteristic of the operation of the pump motor (4) does not reach the first threshold value, the control system (17) commands a new opening of the filling valve (12), evaluates the characteristic signal of the operation of the motor of the pump (4) and once the characteristic signal of the pump motor operation (4) has reached the first threshold value, the control system (17) commands the closing of the filling valve (12) and controls the motor of the pump (4) at the aforementioned second speed; - with the pump motor (4) at the aforementioned second speed, the control system (17) evaluates the characteristic signal of the operation of the pump motor (4); And - if the characteristic signal of the pump motor operation (4) reaches or exceeds a second threshold value, the control system (17) controls the continuation of the treatment program, or - if the signal characteristic of the operation of the pump motor (4) does not reach the second threshold value, the control system (17) commands a further opening of the filling valve (12), evaluates the characteristic signal of the operation of the motor of the pump (4) and once the characteristic signal of the pump motor operation (4) has reached the second threshold value, the control system (17) commands the closing of the filling valve (12) and controls the continuation of the treatment program. The method according to claim 6, wherein the predetermined time span is between 40 and 80 seconds. The process according to claim 6 or claim 7, wherein the second rate is a processing rate. The method according to any one of the preceding claims, wherein the sensor is an impeller meter. The method according to claim 6, wherein, if after the aforementioned new opening of the loading valve (12), the characteristic signal of the operation of the pump motor (4) does not reach the aforementioned first threshold value within a further period of predetermined time, the control system (17) commands the end of the treatment program. The method according to any one of the preceding claims, in which the sensor (13) is arranged on a water supply line from an external water mains to which the household appliance (1) is connected. The method according to any one of claims 1-10, wherein the sensor is arranged on a water supply line extending from a tank inside the household appliance to its treatment container (3). 13. A water conduction household appliance, which implements the process according to one or more of claims 1-12, comprising a treatment container (3), a loading valve (12) placed on a line (11, 14 ) for the water supply to the treatment container (3), a sensor (13) designed to detect the water supply to the treatment container (3), a control system (17).