ES2309667T3 - DISHWASHER AND DRYING PROCEDURE OF THE DISHWASHER IN SAID DISHWASHER. - Google Patents

Abstract

The machine has a drying air intake system (8), and a washing tank (1) whose sides (15, 16) support racks (2) containing dishes. Electromechanical vibration generators include ferrite plates (3) associated to electromagnets. The vibration generators are mechanically connected to the racks, and make the water drops remaining on the dishes and on the racks, after washing cycle, to drop. An independent claim is also included for a method for drying the dishes in a dish washing and drying machine.

Description

Dishwasher and drying procedure of the dishes in said dishwasher.

The present invention relates to dishwasher comprising a washing tank where the walls they adapt to support some baskets destined to contain the crockery and that is tightly closed during the cycles of washing and drying.

The present invention relates, in particular, to a draining and drying system of the dishes contained in said Cuba.

It also refers to a drying process of dishes carried out in said washing machine and drying the crockery.

In general, this invention relates to dishwasher in which a wash cycle of an amount of tableware is followed by a drying cycle of said tableware.

Said machine for washing and drying dishes It includes a washing tank and sliding mounted baskets about some guides in that Cuba.

The dishes to be washed are placed in at least one basket that includes some rods that allow the draining of the tableware so that water circulation can occur during different phases of the dishwashing and drying cycle.

To perform this dish drying cycle In the dishwasher wash tank, there are three types of drying of the dishes.

A first means of drying the dishes consists of in drying by natural convection with the help of resistances electric heaters mounted on the bottom of the washing tank machine.

This type of solution presents the inconveniences of not being economical and of getting low benefits.

A second solution is to dry the dishes with the help of a condenser arranged in the washing tank. In this case, to evaporate the water in contact with the dishes, it is it is necessary to circulate a curtain of cold water along the less one of the walls of the wash tank. This procedure is  complex to perform and expensive. In addition, it does not guarantee that it will be obtained. satisfactory drying performance.

A third drying medium consists of drying the tableware by forced convection with the help of a mounted fan in the structure of the dishwasher. In this case, we must anticipate ventilation ducts that allow to connect the washing tank with a air-water exchanger placed outside of said washing tank.

This type of solution presents the inconveniences linked to the presence of the fan and the air-water exchanger, large dimensions, of generating noise in the case of the fan and of being expensive.

In these state-of-the-art machines, the water slides through the dishes and then through the rods of the baskets to be evacuated later by the treatment circuit of the wash water thanks to a conditioned outlet in the bottom of the wash tank, in communication with the circuit wash water treatment.

Generally, this water outlet hole washing is located at the bottom of the washing tank, preferably in the center of the wash tank.

However, due to the slippage of water on the dishes, which form drops of water in the intersection of the rods of the baskets and the dishes.

The high surface tension of these drops of water prevents these drops of water from falling to the bottom of the tank Washing the washing machine and drying the dishes.

In addition, the contact points of the dishes with basket rods are more important in the upper basket of the washing tank, since they contain the small pieces of dishes placed on top of the tank because of its size. Water drops in contact with the basket rods upper and said small pieces of crockery have the inconvenience of wetting the dishes placed in the basket bottom of the wash tank. This phenomenon is verified above all when the user removes the dishes from the washing tank.

This inconvenience is further accentuated by drying large amounts of small tableware, since this crockery is placed mostly on the top of the tank washed.

The use of the three drying techniques cited above is not optimized, so that the dishwashers of the Current technical status shows low drying results along with high energy consumption

These high energy consumptions are explained due to the fact that it is necessary to have a long duration of drying to obtain a correct drying of the dishes.

A washing procedure of parts, used for medical purposes or in laboratories, which are washed in a dishwasher, according to document DE3625784 A1. The parts to be washed are washed and dried by evaporation of the liquid that is adheres to them. The procedure includes a phase in which Shake the pieces after washing.

In this document, media such as cams are used Eccentric to generate the vibrations of a basket of dishes. Said eccentric cams are arranged under the wheels of the basket of crockery.

The means for shaking the dishes described in DE3625784 A1 generates vibrations according to oscillations predetermined by the manufacturer that are linked to the profile of the eccentric cams. These means to shake dishes they have the disadvantage that they do not overcome surface tension that joins the drops of water to the dishes and the rods of a basket of dishes to make those drops of Water.

The present invention aims at solve the aforementioned problems and propose in general a means of drying the dishes contained in the washing tank of a dishwasher minimizing energy consumption, improving drying results and, above all, eliminating water droplets that they are formed at the intersection of the rods of the baskets and of the crockery.

For this, the present invention relates to a machine to wash and dry the dishes comprising a bowl of washing whose walls are suitable for supporting baskets containing crockery.

Said drying medium is complementary to one of the drying means already known.

The dishwasher is equipped with a medium vibration generator intended to make the drops of water left after the wash cycle.

According to the invention, said means of generating vibrations is arranged to emit at least two frequencies Fixed different.

In this way, the vibrations transmitted to the less than one of the baskets preferably drain the dishes of so that the water fall on the dishes is improved allowing the evaporation of this on the dishes.

According to one of the preferred characteristics of the invention, the vibration generator is associated with at least One of the baskets.

In this way, the drying of the dishes is carried out directly in one of the basins of the wash tank and can be generated with means of transmitting the waves to others baskets

Water draining is optimized in this way in contact with the dishes and the rods of the baskets in the tank washing

According to another preferred feature of the invention, the vibration generator is mechanically attached to the At least one of the baskets.

In this way, drying can be obtained by tableware vibrations with a simple displacement of at least one of the baskets in a horizontal or vertical plane.

The vibration generator is set to a frequency in a range of 7 to 25 Hz. Preferably, the vibration generator is adjusted to a frequency of the order 20 Hz. for vibrations in a horizontal plane.

According to another preferred feature of the invention, each basket has the general shape of a parallelepiped, so the vibration generator is electromechanical and comprises a transmitter connected to one of the angles of said basket. The vibration generator is conditioned to transmit a horizontal vibration according to the angle bisector of that basket.

In this way, the transmitted vibrations horizontally at least one of the baskets allow to make it slide the water droplets on the horizontal rods of the baskets and especially at the points of contact. In this way, the water drops cover a larger surface of the rod and is more Easy to dry. Choosing this angle allows you to shake all horizontal rods, either horizontal or transverse.

According to a second aspect, the invention is refers to a procedure of drying the dishes in a dishwasher comprising a washing tank whose walls are suitable for holding baskets with dishes, including said tableware drying procedure a stage of generating vibrations in the wash tank emitted at least two different fixed frequencies successively in order to make that the drops of water fall in contact with the dishes and baskets after the wash cycle.

This tableware drying procedure allows to use the traditional drying medium better and reduce thus the energy consumption during drying.

The problem to fine tune this drying procedure is that fragility must be taken into account  of the dishes. This drying procedure will reveal how this feature was taken into account to carry out the invention.

The following description will show others particularities and advantages of the invention.

In the accompanying drawings, given by way of examples non-limiting:

- Figure 1 is a schematic sectional view cross section of a washing tank of a machine for washing and drying the dishes according to a first embodiment of a generating means of vibrations according to the invention;

- Figure 2 is a schematic sectional view cross section of a washing tank of a machine for washing and drying the dishes according to a first embodiment of the invention, which shows an electrical wiring of the generator medium of vibrations;

- Figure 3 is a schematic sectional view cross section of a washing tank of a machine for washing and drying the dishes according to a first embodiment according to figure 1

- Figure 4 is a schematic sectional view cross section of a washing tank of a machine for washing and drying the dishes according to a second embodiment of the invention;

- Figure 5 is a schematic sectional view cross section of a washing tank of a machine for washing and drying the dishes according to a third embodiment of a generating means of vibrations according to the invention;

- Figure 6 is a schematic representation enlarged basket vibration generator shown in the figure 5; drying air suction circuit 8 represented only schematically.

Of course, the set is described in a Machine housing 5 which is not necessary to describe here.

In addition, all of the other components necessary for the operation of a dishwasher, as per example control means, power supply and power of water, have not been represented or described as they can be identical to those already known by experts in the field.

This machine for washing and drying dishes it first comprises a washing tank 1, so parallelepipedic The washing tank 1 comprises a cover 11 in U-shape, a roof 12, a bottom wall 13 and a door 10 that it allows to plug the wash tank 1. The walls of the roof are suitable for supporting at least one basket 2, in this case two baskets, intended to receive dishes. In the state of the art, the Baskets 2 present the general shape of a rectangle parallelepiped and are formed by crisscrossed and welded rods that form a bottom and a flange with four practically straight angles.

This wash tank 1 is mounted in a housing 5 also in a parallelepipedic way.

Classically in these machines to wash and drying the dishes, an air inlet opening 6 is included in the roof 12 of the wash tank 1 and an air outlet opening 7 on the bottom wall 13 of the wash tank 1, so that the used air can enter the drying phase of the dishes and,  Once loaded with moisture, evacuate from the wash tank 1. These two openings are connected to a suction circuit of the drying air 8. The drying air circuit 8 comprises a conduit 4 mounted on the outside of the wash tank 1.

To ensure the circulation of drying air through that conduit 4, a fan (not shown) is provided mounted on the ventilation duct 4 in a suitable place.

In addition, an air-water exchanger (no represented) is placed in conduit 4 near the drying air outlet opening 7. Said air exchanger - water can be in a known way a water damper in which moisture-laden air comes into contact with the cooled wall by water and a part of the moisture condenses.

This embodiment allows adapting several variants in which the air treatment circuit can Be open or semi-open. It is considered that the circuit of treatment is open when an introduction opening of Drying air provides ambient air. A treatment circuit of semi-open air is a circuit in which the mixing air of the washroom is mixed with an air intake environmental.

Finally, they are usually placed heating means (not shown) in conduit 4 near a drying air inlet opening 6 in the washing tank 1 to raise the temperature of the drying air intended to enter contact with the dishes to be dried.

These means of drying air treatment in the air circulation duct 4, formed by a air-water exchanger and a heating medium, are indicated only by way of non-limitation in this embodiment. Any other drying device could also be applied, by condensation or evaporation in this type of washing machine and Dry the dishes.

A machine for washing and drying dishes It also includes a washing water treatment circuit and rinse of the dishes. Said water treatment circuit of washing and rinsing has not been represented in the figures so that Be more readable. The washing water treatment circuit and rinsing comprises a conduit mounted on the outside of the tank wash 1 and put in communication with the interior of the tank washing 1 at the level of the floor 14 and the roof 12 of the washing tank one.

A motor pump (not shown) mounted under the solera 14 of the washing tank 1 allows to circulate the water in the washing and rinsing water treatment circuit.

The wash tank 1 is manufactured with a non-ferrous material, such as non-magnetic stainless steel.

According to the invention, the dishwasher is equipped with a vibration generator medium intended to make drop the drops of water left in the dishes and in the basket (s) 2 after the wash cycle.

In this way, the emitted vibrations can generate by resonance the vibration of the raindrops or the tableware vibration favoring the sliding and falling of these drops of water.

An embodiment according to the invention is to vibrate the dishes contained in the baskets according to a vertical plane to the horizontal plane going through basket 2 that It contains the dishes.

According to a preferred embodiment, the medium vibration generator is associated with at least one of the baskets 2; in the figures represented by two baskets.

The application made has revealed that the time necessary for the drops to fall is of the order of 1 minute.

These experiments allow us to conclude that the drying performance with respect to additional energy consumption necessary has not been significantly improved.

In addition, trials have shown that it is it is preferable to increase savings to obtain a drying performance high. This setting parameter allows to obtain amplitudes of strong vibrations but you run the risk of damaging the crockery.

The main parameter revealed in This experience plan is the amplitude of the vibrations. He instant of vibration generation and duration of Vibrations do not have great influence on the result.

The surface tension of water droplets is too important and does not allow such drops to fall despite of the vertical acceleration transmitted by the generator vibrations

This embodiment that has the objective of generating vibrations in a vertical plane allows responding to needs to drain the baskets 2 containing the dishes.

However, the drying efficiency of the dishes It can be improved with another embodiment.

From this observation, the applicant has made the vibration setting of the baskets 2 in a plane horizontal. This mode of vibrations allows to make the drops of water slide on the dishes, on the rods of the baskets 2 and, above all, on the contact points between the dishes and the baskets 2. The more surface the drop covers and therefore less Its thickness will be easier to dry.

In addition, the size of the water droplets has importance in the result of drying. The larger the size of the drops the greater the surface tension of these. In Consequently, the drying performance is of lower quality. Is it is preferable to generate the vibrations at the level of the basket 2 in a relatively short time after the rinse cycle.

This embodiment of vibration drying has allowed to characterize the set-up parameters of this system in a dishwasher according to the invention. Then these parameters are described.

The vibrations are generated by scanning frequency. This mode of vibration of the drops allows to create a progressive acceleration in water droplets.

The vibrations are generated by an increase of two or several frequencies. This vibration mode allows you to create a sharp acceleration in the drops of water.

The vibration generator is set to less at a frequency in the range of 7 to 25 Hz.

Preferably, the vibration generator is set to a fixed frequency of the order of 20 Hz.

In one embodiment, the generator vibrations is set to emit at least two frequencies Fixed different.

For example, a first frequency allows drain the small-sized dishes and a second frequency allows to drain the large dishes.

These frequencies should not correspond to the resonance frequency of the dishwasher structure since the aforementioned resonance frequency would cause vibrations of the structure and consequently noise outside the dishwasher.

In addition, the frequencies emitted by the vibration generator correspond to the frequencies of excitation of the drops in contact with the dishes and baskets 2. These frequencies are different for each type of dishes and depend on the shape of the contacts between the dishes and the baskets or of the tableware itself, for example, the bottoms of the cups and the vessels need a specific frequency so that you can drain the water that has stagnated in a concavity formed at the bottom of the cup.

In addition, these frequencies are set according to of the surface tension of the materials that constitute the Different types of dishes.

Said at least two fixed frequencies are suitable for not generating noise in the wash tank 1. In In any case, the frequencies emitted by the generator vibrations must correspond to the resonance frequencies of the dishes or baskets.

Therefore, the vibration generator must allow to generate vibrations at different fixed frequencies or by sweeping or in intensity.

The fixed frequencies that interest for Drain the most different types of dishes are those of 17, 20 and 25 Hz.

The frequency of 17 Hz corresponds to the optimal frequency to drain the cutlery, the frequency of 20 Hz. Is for saucers and glasses and the frequency of 25 Hz. For cups.

The optimal fixed frequency for each type of tableware is also suitable for other types of tableware so that no noise is generated. Each fixed frequency emitted by the vibration generator allows to drain at least partially All kinds of dishes.

The vibration generator is adapted to emit said at least two fixed frequencies successively. These at least two fixed frequencies are emitted for periods of time determined according to the type of dishes that are going to drain.

In one embodiment, the generator vibrations emits waves whose amplitude is in the range 0.6 to 1 mm in a vertical plane.

Or in another embodiment, the generator vibrations emits waves whose amplitude is in the range 0.5 to 0.7 mm in a horizontal plane.

The generation of vibrations is emitted preferably in a horizontal plane.

In addition, the vibrations are oriented in a particular direction to make the most amount of water drops on the set of rods in the baskets 2. This direction is according to the bisector of the angle of the basket 2.

We will describe now, more particularly referring to figures 1 to 3, the means of generating vibrations meant to make the raindrops fall that remain after the wash cycle and optimize the drying cycle combining it with a drying mode as described above. In this first embodiment, the transmission of vibrations is effect by means of a magnetic system.

The vibration generator is associated with the baskets 2 without direct relationship between the parties located in the inside and outside the washing tank 1. The generator of vibrations is electromechanical type and comprises a transmitter connected to at least one of the angles of the basket 2. Said transmitter comprises a plate 3 of magnetic material fixed on the minus an angle to transmit horizontal vibrations according to the bisector of said angle of the basket.

The magnetic material plate 3 is preferably ferrite.

Preferably, the basket comprises two plates of ferrite 3, the second ferrite plate 3 being arranged in the opposite angle.

The magnetic material plates 3 also They can be made of ferromagnetic steel.

In front of said plates of magnetic material 3, the washing tank 1 comprises on its sides 15, 16 some electromagnets 17 each with a solenoid 20.

As shown in figures 1 and 2, the machine to wash and dry the dishes includes a pair of ferrite plates 3 in each basket 2 and with an electromagnet 17 associated with each plate of ferrite 3 thus forming a means of generating vibrations by basket 2.

To guarantee the vibrations of one or several baskets 2, a means of control 18 of the periods of vibration or simply its absence is placed before the electromagnets 17. Said control means 18 has switching means for activate or deactivate the vibration generation system.

This control means 18 also has a frequency generator

In this exemplary embodiment, the system of vibration generation is powered with 230V alternates and a 50 Hz frequency

The results obtained in the trials, we have allowed to observe that the drops of water slide along the rods of baskets 2 when vibrations are emitted in a plane parallel to the longitudinal axis 23 of the washing machine and Dry the dishes.

This observation is important since the drops of water are easier to drain when spread over a large area that if several drops of water are grouped in a single point This finding comes from the fact that the tension The surface is smaller the larger the contact surface. This  It is even more important to keep in mind since the water contains still some particles of active ingredients after finishing the rinse cycle. Said particles of active ingredients contained in the water increase the surface tension of the water that It is on the dishes and on the baskets 2.

In a preferred embodiment, this vibration generation system forms a means of transmission of the vibrations by magnetism that allows to vibrate the baskets 2 in a horizontal plane and according to the bisector of the angle of said basket 2. The orientation of the vibrations with respect to the basket 2 is equivalent to giving a direction that forms an angle? with respect to the longitudinal plane that crosses the wash tank 1. Said angle? Takes a value close to 45 ° given the shape of basket 2 containing the dishes as it is known currently.

Of course, this provision could be of 90º.

It will be described below, referring to the Figure 4, a mode of transmission of the waves by link direct.

In this embodiment, only needed a ferrite plate 3 and a single electromagnet 17 with a core magnetic 19 and a solenoid 20.

In this way, the electromagnet 17 is part active frequency generator for the transmission of vibrations to basket 2 containing the dishes.

Preferably, this electromagnet 17 is placed at an angle of the basket 2 and generates the vibrations according to the bisector of said angle of the basket 2.

In this way, the vibrations are transmitted according to a 45º direction with respect to the rods of the basket.

The electromagnet 17 flows into the wash tank 1 through an opening 9 placed on the side 15 of the washing tank 1 and the bottom wall 13 of the wash tank 1.

The retraction of the basket 2 is carried out by elastic means. A spring sheet 21 is placed on the counter-door 22 of door 10 at the angle opposite to the one in which the electromagnet is placed 17. The blade spring 21 is formed by two fins that rest on the basket 2 of the dishes. The fixing means of the spring leaf 21 are preferably elastic retention means.

Conversely, the spring sheet 21 may be attached to basket 2 and lean against the counter-door 22

In this way, the basket 2 of dishes can be put into vibration according to a horizontal plane and in a direction of 45º with respect to the longitudinal axis 23 of the washing machine and Dry the dishes.

The opening 9 disposed between the side 15 of the wash tank 1 and bottom wall 13 of wash tank 1 it can have any form and have for example a form circular.

Due to the effect of water pressure during dishwashing created with spray media placed in the washing tank 1, the water is projected at the level of the opening 9 on the side 15 of the washing tank 1 and the bottom wall 13 of the wash tank 1. The water found in wash tank 1 is  it can infiltrate the opening 9 and damage the electromagnet 17.

To eliminate leaks through the opening 9 provided between the side 15 of the washing tank 1 and the wall of the bottom 13 of the washing tank 1, a sealing means 24 is adapted to insulate the interior of the wash tank 1 of the casing 5 of the machine to wash and dry the dishes and protect the 17 electromagnet of moisture.

These water sealing means 24 are extend between the side 15 of the wash tank 1 and the wall of the bottom 13 of the wash tank 1.

In the embodiment shown in the Figure 4, these water sealing means 24 comprise a rubber bellows 24 which in this embodiment is extends between the side 15 of the wash tank 1 and the wall of the bottom 13 of the wash tank 1.

This bellows 24 extends from so that it is in contact with the electromagnet 17. The bellows of tightness 24 is in physical contact with the basket 2 for guarantee the generation of vibrations and their control in basket 2 containing the dishes.

Of course, the sealing means 24 of the water between the side 15 of the wash tank 1 and the bottom wall 13 of the wash tank 1 could be different and, for example, include at least one O-ring seal placed around the electromagnet 17.

The generation of vibrations can be also perform in a different way in a third way of embodiment of the invention, as shown in figures 5 and 6.

The common elements with the first two modes of embodiment shown in Figures 1 to 3 have the same numerical references, so they will not be described in new.

These common elements are fundamentally the housing 5, wash tank 1, door 10 and basket 2 which It contains the dishes.

In this third embodiment, the machine to wash and dry the dishes includes generation means of the vibrations of the basket 2 by means of a gear train 25 and 26 comprising an imbalance 27 in at least one 25 of the gears

The gear 26 is integral with the washing tank 1 and is dragged directly by an electric motor 28. The second gear 25 which includes an imbalance 27 in its axis is lodges in basket 2.

To guarantee the generation of vibrations of the basket 2 by imbalance 27, a readjustment of lateral play on the motor 28 and its gear 26 with respect to the gear 25.

The readjustment of play between the gears can be carried out using axes of said gears that have an elastic characteristic. In addition, gears can be mount so that the interlocking of said gears is tight.

Thus, gears 25, 26 remain in contact during the entire phase of vibration generation.

The generation of vibrations is produced by the imbalance 27 put into rotation. This imbalance 27 generates pulses transmitted to basket 2 containing the crockery.

A first embodiment consists of make up the side games of the side game guides of the baskets 2 and in absorbing the vibrations of the basket 2 generated by the imbalance 27.

In a second embodiment, the gear 25 in basket 2 has a radial flexibility with respect to axis of imbalance 27, to absorb games and vibrations. On the contrary, the imbalance shaft guide 27 is integral to basket 2 to impose rotating vibration.

The experiences made during the development of this invention have shown that a particular frequency range to vibrate the basket 2 that It contains the dishes. This frequency range is between 7 and 25 Hz.

Preferably, the drying is optimized with a frequency of the order of 20 Hz. in a horizontal plane.

Another advantage of these embodiments is the drained from the dishes that comprise a hollow area, like glasses and saucers placed turned around. Of this mode, the water that is in said hollow area is evacuated with the vibrations transmitted to basket 2 containing the crockery.

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In a fourth embodiment as shown in figure 8, the vibration generator 32 of the dishes and of the basket 2 is physically joined by a sliding means of said basket 2.

The sliding means of the basket 2 includes a guide rail 30 of the basket 2, fixed wheels 31 and attached to the wash tank 1 and wheels 29 mounted on the basket 2. This telescopic sliding means allows basket 2 to exit the wash tank 1 when sliding on the fixed wheels attached to the wash tank 1 and then a guide rail 30 allows the basket 2 slide with the wheels 29 attached to said basket 2.

The wheels 31 mounted in the washing tank 1 also allow transmitting the vibrations transmitted by a vibration generator 32 located under each wheel. This means of Vibration generation allows the basket 2 to vibrate in one vertical plane

Elastic and watertight elements are arranged between the wash tank 1 and the wheel holders 31.

To eliminate the noise problems generated by the vibration of the basket 2 transmitted by the wheels 31, it they can place rubber noise absorbers between the washing tank 1 and the axle of the wheels 31.

A drying procedure will now be described. according to the invention and its different phases that can be performed after a rinse phase in a dishwashing cycle, so that the drying procedure is directly chained after the end of the wash cycle.

Thus, when performing the procedure of drying, a first drying phase can be foreseen in which the dishes are drained naturally for example a time t 5 minutes

During this phase, it is not useful to start drying of the dishes with vibrations since the washing water has not Finished running on the dishes.

At the end of this period of natural draining, water drops form at the intersection points of the dishes and of the rods of the baskets 2 as shown in figure 8 or for example in the hollow parts of cups and saucers. These Water drops should be removed to improve the drying result  of a machine for washing and drying dishes.

In a second drying phase, the vibrations with a vibration generator at a frequency f between the range of 7 to 25 Hz. according to a plane parallel to the plane of the largest surface that passes through the basket. This type Drying is particularly advantageous when dishes include numerous small parts, since the number of contact points of the dishes with the rods of the baskets 2 is more numerous.

In that horizontal plane, the water drains preferably through the rods of the baskets 2.

The period T of vibration generation is order of 15 seconds for a frequency f of 7 to 25 Hz. Preferably, the vibrations are emitted during a period T of 15 seconds at a frequency f of 20 Hz.

The various experiments and tests have allowed to define these data relative to frequencies and durations of the vibrations transmitted to the basket. The Frequently used frequencies are fixed. In this way, the means that must be applied to perform this drying principle They are relatively simple and economical.

In another embodiment, the means for generate the vibrations can emit waves by scanning frequency. In practice, a regular frequency sweep is more difficult to perform that emit vibrations with a fixed frequency. In addition, the results obtained in the trials have not allowed us to see a saving in energy consumption with this mode of realization.

In the case of drying the fragile dishes, it is it is preferable to generate reduced vibration amplitudes and preferably vibration generation durations are sufficient reduced This drying mode of fragile dishes is effective and enough to drain the dishes.

In another embodiment of the invention, You can drain the dishes generating vibrations at the end of each washing and rinsing phase of an operating cycle of the dishwasher.

At the end of the wash and rinse phases, the amount of liquid left from the bathroom in the dishes and baskets 2 is of the order of 0.3 L. This amount of bath liquid is formed by water, soaps and food waste. This amount of bath liquid is diluted in the bath of the next phase of the cycle during filling. This dilution decreases the effectiveness of rinsing phases

A procedure of drained from the dishes according to the invention and its different phases which can be applied after a washing phase and / or a phase of rinsing of a dishwasher operating cycle.

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Thus, when applying the procedure of drained from the dishes, a first phase of drained in which the dishes are drained naturally during a t time of a few seconds.

During this phase, it is not useful to start the drained from the dishes by vibrations since the wash water does not He has finished running on the dishes.

At the end of this period of natural draining, water drops form at the intersection points of the dishes and of the rods of the baskets 2 as shown in figure 8 or for example in the hollow parts of cups and saucers. These Water drops should be removed to improve the drying result  of a machine for washing and drying dishes.

In at least a second draining phase of the tableware, vibrations are emitted with a vibration generator at a frequency f between the range of 7 to 25 Hz.

Said at least second draining phase of the tableware is preferably performed for at least one phase of wash or rinse.

In a preferred embodiment of the invention, the vibration generator is started during at least one phase of washing or rinsing.

Said at least dishwashing phase it is carried out during the emptying period of the wash tank 1 in at least one phase of washing or rinsing.

The emptying period may correspond to the less at a stage of draining the dishes naturally followed by a phase of drained by vibrations. These two phases of drained are followed by a phase of emptying the washing tank 1 in which a pump is put into operation. During the phase of emptying of the washing tank 1, the natural draining phase or of drained by vibrations can continue during the phase of emptying

This type of draining is particularly advantageous when the dishes contain numerous small pieces, since that the number of tableware contact points with the rods of baskets 2 is more numerous.

This procedure has the advantage of limiting the amount of dirty bath liquid left in the dishes and that It is diluted in the next bath liquid.

According to a feature of the invention, the vibration generator is set to emit at least two different fixed frequencies.

In this way, the efficiency of the phases is improved of dishwashing.

Therefore, the dishwashing quality It is better in every dishwasher operating cycle.

In addition, this draining procedure of the tableware allows you to better use the bath liquid of each phase of the operating cycle of the dishwasher and thus reduce consumption energy and also reduce the time of said cycle.

The preferred vibration generator for the embodiment of the invention is that of the electromechanical type. Further, This vibration generator is mechanically connected to the basket 2 which contains the dishes.

Thus, if there are many small pieces of dishes in the baskets, the vibrations allow to drain effectively the dishes before the end of the cycle. This avoids the inconvenient of wetting the dishes when removing them from the dishwasher.

In this way, the duration of the drying, thus limiting the consumption of electrical energy.

Of course, many can be provided modifications to the embodiments described above without leave the scope of the invention.

Claims (16)

1. Dishwasher comprising a washing tank (1) whose walls (15, 16) are adapted to support baskets (2) containing the dishes, said dishwasher being equipped with a vibration generating means (3, 17, 19, 20, 21, 25, 26, 27, 32) intended to cause the drops of water that remain in the dishes and in the basket (2) to fall after the washing cycle, characterized in that said vibration generating means ( 3, 17, 19, 20, 21, 25, 26, 27, 32) so that it emits at least two different fixed frequencies. 2. Dishwasher according to claim 1, characterized in that the vibration generator is associated with at least one of the baskets (2). 3. Dishwasher according to claims 1 or 2, characterized in that the vibrations are generated by frequency scanning. 4. Dishwasher according to any one of claims 1 to 2, characterized in that the vibrations are generated by an increase of two or several frequencies. 5. Dishwasher according to any one of claims 1 to 4, characterized in that the vibration generator is adjusted to at least a frequency in the range of 7 to 25 Hz. 6. Dishwasher according to claim 5, characterized in that the vibration generator is set to a fixed frequency of the order of 20 Hz. 7. Dishwasher according to claims 5 or 6, characterized in that the vibration generator emits waves whose amplitude is in the range of 0.6 to 1 mm in a vertical plane. 8. Dishwasher according to claims 5 or 6, characterized in that the vibration generator emits waves whose amplitude is in the range of 0.5 to 0.7 mm in a horizontal plane. 9. Dishwasher according to any one of claims 1 to 8, characterized in that the vibration generator is arranged to transmit a horizontal vibration according to the bisector of one of the angles of said basket (2). A dishwasher according to any one of claims 1 to 9, characterized in that each basket (2), which has the general shape of a parallelepiped, is associated with at least one vibration generator that is electromechanical and comprises a transmitter connected to the at least one of the angles of said basket (2). 11. Dishwasher according to claim 10, characterized in that the vibration generator is associated with elastic recovery means (21) of the basket (2) containing the dishes. 12. Dishwasher according to any one of claims 2 to 11, characterized in that the vibration generator (32) of the dishes and the basket (2) is physically connected by means of sliding means to said basket (2). 13. Method of drying the dishes in a dishwasher comprising a washing tank (1) whose walls (15, 16) are adapted to support some baskets (2) containing the dishes, characterized in that said method of drying the dishes it comprises a stage of generating vibrations in the washing tank (1) emitted at least two different fixed frequencies successively with the aim of causing the drops of water to fall in contact with the dishes and the baskets (2) after the cycle of washed. 14. Drying method according to claim 13, characterized in that the vibrations are transmitted to the baskets (2) by a vibration generator and emitted at a frequency in the range of 7 to 25 Hz, according to a plane parallel to the plane of the larger surface that passes through the basket (2). 15. Drying method according to claim 14, characterized in that after washing a drying cycle is carried out during which the vibrations are emitted from a drying time t according to a period T of the order of 15 seconds at a frequency f comprised between 7 and 25 Hz. 16. Drying method according to claim 15, characterized in that the vibrations are emitted from a time of 5 minutes of drying according to a period of 15 seconds at a frequency of 20 Hz.