EP2428608B1 - Method for operating a pump in a washing machine, mechatronic system and washing machine - Google Patents

Description

The invention relates to a method for operating a pump with an electronically commutated motor for a Umfluteinrichtung or drain device in a washing machine, comprising a tub for receiving washing liquid for treating laundry within the tub, wherein the method has at least one washing phase, in the Lye container washing liquid is, being promoted to the end of the washing phase by means of the drainage device out of the tub.

For washing laundry in a drum washing machine, the laundry is moved in the rotating drum, whereby the wetting of the laundry with the washing liquid and the washing mechanism are effected. In this case, there is water in the tub or in the drum, wherein the dirt is flushed out by the movement of the laundry. In order to bring the wash as completely as possible in connection with the laundry, it is known to raise the laundry and a portion of the washing liquid by means of drum rotation from the lower region, so that the laundry items located in the drum are sprinkled from above with washing liquid or with the Washing liquid are mixed. After washing, the washing liquid is pumped, wherein the washing liquid is expelled from the laundry due to the centrifugal force occurring from the laundry by a so-called intermediate centrifuging.

The disadvantage here is that in strongly absorbent laundry when spinning much water exits the laundry, which can not be completely pumped by a constantly driven pump drainage. In order to avoid the undesirable effect of the so-called water jacket, the spinning is interrupted until the washing liquid has fallen below a predetermined level in the tub. Thereafter, the spin is activated again. The disadvantage here is that extends the entire wash program and due to the repeated spin ramps increased mechanical stress on the laundry can take place.

The US 2004/078902 A1 discloses a method of operating a pump with an electronically commutated motor in a washing machine. The method further defines that to start pumping, the pump is supplied with an increased frequency, to achieve a higher flow rate for a specified period of 1 to 2 minutes. Thereafter, the applied frequency is reduced to reduce noise when there is too little water and the pump sucks in air.

From the US 2004/0088797 A1 It is known to control a pump with an electronically commutated motor for a Umfluteinrichtung or drain device by means of a frequency converter. Here, the pump power over the If there is a risk that the pump will suck in air when the water level in the machine falls below a lower limit.

From the EP 1 638 201 B1 It is known to control the drain pump of a drain device by means of an electrical switch to make an adjustment of the engine operation to the pump load. In this case, a partial load operation is detected and then the engine briefly or switched off or off or switched in a predetermined duty cycle.

The invention is therefore based on the object to provide a method for operating a pump, in which an optimal operation of a water-conducting device is achieved.

The object is achieved by a method having the features of claim 1, by a mechatronic system according to claim 8 and by a washing machine according to claim 9. Advantageous embodiments will be apparent from the respective dependent claims.

In the method according to the invention, it is provided that the delivery rate of the pump is varied as a function of the detected level of the washing liquid in the treatment container. As a result, based on the program that defines a treatment procedure in the washing machine, the delivery rate of the pump can be specifically influenced or specified, so that the treatment process does not have to be adapted or hardly adapted to the properties of the pump.

In an advantageous embodiment, when a predetermined upper level of the washing liquid in the tub treatment container is exceeded, the delivery rate of the pump is at least temporarily increased, compared to the nominal delivery rate. This state, also known as boost mode, makes it possible to use a pump with a smaller nominal delivery capacity, which is perfectly adequate for normal continuous operation. For the time-limited, increased load, the pump or the motor of the pump is suitable or the time limit is such that no destruction of the pump or the motor occurs.

It is advantageous that falls below a lower limit, the capacity of the pump is reduced, compared to the nominal flow rate. As a result, the time of the boost operation can be shortened if the level before the expiration of the maximum allowable time for this overload operation permits.

In an expedient embodiment, the increase and / or the reduction of the delivery rate are gradual. For example, in a simple embodiment, the boost mode can be carried out with 1.2 to 2 times the nominal delivery rate.

In another expedient embodiment, the increase and / or the reduction of the delivery rate are carried out continuously. Thus, an on-demand boost mode may be provided in which the overload factor varies during the boost operation, depending on the conditions or levels of liquid present in the treatment vessel.

When using the method in a washing machine, which comprises within the tub a horizontally or inclined rotatably mounted drum, which is driven by a motor, and the method comprises a spin phase for dewatering the laundry, it is advantageous that the capacity during the spin phase in Depending on the detected level of the washing liquid is increased or decreased within the tub. Shortly after the start of the spin phase an increased amount of liquid must be very quickly conveyed out of the suds container so that no so-called water jacket between the drum wall and the suds container wall is formed by entrained liquid. Increasing the capacity at the beginning of the spin phase avoids this effect.

Overall, it is expedient to limit the predetermined period in which the delivery rate of the pump is increased to a time which is in the range of 3 to 15 seconds. It must also be ensured that a boost operation is followed by a phase that is at least 5 times longer than the boost mode, during which phase the motor is switched off or operated at nominal power. Such relatively short thermal overload phases do not cause damage to the motor.

A frequency converter for energizing at least one electronically commutated motor for driving a pump for conveying washing liquid in a water-conducting device is also provided, which is adapted for a given period of time the motor increased electrical power in the form of increased voltage, current and / or Supply frequency which is adapted to cause an increased flow rate of the pump for the predetermined period of time, wherein the predetermined period for the increased electrical conduction can be supplied to the frequency converter. Thereby, a corresponding existing pump can be set up with a simple modification of the converter for a demand-oriented operation of the liquid delivery.

The invention further relates to a mechantronic system comprising a frequency converter as described above and at least one motor for driving a pump, wherein the motor is a permanent magnet synchronous motor. The mechatronic system provides optimum engine function for on-demand pump operation because the components and switching behavior of all components in the frequency converter are optimally matched to the characteristics of the engine.

In an advantageous development, the mechatronic system comprises a further electronically commutated motor for driving a further pump, wherein the frequency converter is adapted to supply one of the two motors with increased electrical power for a predetermined period, and the other motor with at most rated power supply. This avoids overloading the frequency converter if only one single motor is supplied with the increased electrical power. Thus, all components of the designed for two motors frequency converter can be designed for nominal load, without causing overheating damage.

The invention further relates to a washing machine with a tub for holding washing liquid for treating laundry, a horizontally rotatably mounted drum in the tub, a motor for rotating the drum, a radiator, a drainage device comprising a mechatronic system as described above, a water inlet device and a Control means for controlling the individual phases of the selected washing program, and further at least one sensor for detecting the liquid level within the tub, which is in operative connection with the control means, wherein the control means is in operative connection with the frequency converter for controlling the motor for the pump and adapted to supply the period for the increased electrical power supplied to the motor to the frequency converter, during the spin phase, depending on the detected level of the washing fluid within of the tub. In this way, the pump operation can be specifically adjusted based on the parameters recorded in the washing process, so that a shortening and an increase in the effectiveness is achieved.

In a washing machine, comprising a Umfluteinrichtung with a Umflutpumpe, which is adapted to at least temporarily to promote washing liquid from the lower region of the tub in the upper region, based on the operational installation position of the washing machine, is the mechatronic system for driving the other Motors intended for driving the circulating pump.

Fig. 1:

eine Waschmaschine in einer skizzierten Schnittdarstellung,

Fig. 2:

ein Waschprogramm als Diagramm im zeitlichen Ablauf und

Fig. 3a - 3c:

die Ansteuerung des Heizkörpers und der Umfluteinrichtung in zeitlicher Abfolge.

An embodiment of the invention is shown purely schematically in the drawings and will be described in more detail below. Show it

Fig. 1:

a washing machine in a sketched sectional view,

Fig. 2:

a washing program as a diagram in chronological order and

3a-3c:

the control of the radiator and the Umfluteinrichtung in time sequence.

In Fig. 1 is a purely schematic representation of a washing machine 1, shown with a trained as a tub 2 treatment tank. The position and direction information refer to the operational installation position of the washing machine 1. Within the tub 2 a rotatably mounted and driven by an electric motor 13 drum 3 is arranged, which moves the laundry items located in the tub 2 8. The drum 3 is made in the present embodiment of stainless steel and provided with a plurality of openings for the flooding. The housing 4 has a loading opening 9, via which the interior of the drum 3 can be reached through the sealing sleeve 6. The loading opening 9 can be closed by means of a door 5. In the lower region of the tub 2, a radiator 7 is arranged, which can heat the washing liquid in the tub. In the upper part of the machine 1, an inlet valve 15 is sketched, which provides the running in of the water from the supply network. About the Einspülkasten 11, the water is passed through the connecting pipe 14 in the tub 2, wherein in the dispenser 11 entered detergent is flushed into the tub 2. Below the tub 2, a drain device 12 is arranged, which leads the spent washing liquid or the rinse water from the tub 2 to the drain line 12c, which usually opens into a sewer. The control device 18 controls the inlet valve 15, the activity of the drainage device 12, the drive motor 13, which is energized via the power unit or a frequency converter (not shown), and the radiator 7. In the lower part of the tub 2, based on the Aufstellsgemäße installation position of the washing machine 1, the pump 17a is mounted in a flooding device. The pump 17a is connected to the drain pipe 12b on the inlet side and suction side, respectively, and can convey the washing liquid 19 therein through the pipe 17b into the upper portion of the tub 2 and the drum 3, respectively. The washing liquid 19 is injected or flows onto the laundry items 8 through the nozzle or the outlet 17c.

In Fig. 1 is also shown that the level of the washing liquid 19 is just below the maximum value Max. At the critical level Crit the heater 7 is just covered with washing liquid, so that no dry heating takes place. Below the minimum Level Min, there is a risk that the circulating pump 17a can no longer completely suck in liquid, so that it can lead to increased noise.

In Fig. 1 is also shown schematically that the pumps 12a and 17a each include an electric motor 12d, 17d, which serves to drive the pump 12a, 17a. In this example, both the motor 12d of the drain pump and the motor 17d of the bypass pump 17a are energized by the frequency converter 16. The frequency converter 16 is operatively connected to the control device 18, so that the control device 18 transmits the specifications to the frequency converter 16 via a signal connection, when the respective pump motors 12d, 17d are to be activated and when the operation should take place with the increased power supply.

In Fig. 2 By way of example, a complete sequence of a washing program WP is shown in a diagram. The individual phases within the wash program WP are shown on the time axis t. The program sequence WP shown here comprises a washing phase Wa, a rinsing phase Sp and a spinning phase Sc. In these individual phases of the water inlet 15 and the outlet 12 is controlled accordingly. Also, the radiator 7 and the Umfluteinrichtung 17 are controlled accordingly to heat the washing liquid 19 to the predetermined temperature. At the beginning of the washing phase, the water is introduced into the flushing device or the dispenser 11, whereby the processing agent stored therein, such as washing powder, is introduced through the connecting tube 14 into the tub 2. This is followed by the heating-up section Hz, in which the washing liquid is heated by means of the activated heating element 7 to the temperature preset by the control device 18 by the selected program. After reaching the predetermined temperature of the radiator 7 is turned off and the so-called Nachwaschabschnitt Na follows. In this Nachwaschabschnitt Na, the laundry 8 is moved by means of rotating drum 3, wherein the washing liquid 19 cools. The washing phase Wa is ended with the pumping, wherein the drain device 12, in particular the pump 12a or a drain valve is activated. When pumping can also be spun so that the scrubbing added with detergent washing liquid 19 is removed from the fabric of the laundry items 8. This is followed by the flushing section Sp, in which fresh water is introduced into the tub 2 and the items of laundry 8 are moved therein. At the end of the rinsing section Sp, the rinse water is pumped out, followed by the final spin Sc for dewatering the laundry items 8. In the final spin, the drum 3 is rotated at a higher speed compared to the washing process, in which the laundry items 8 abut the drum shell and the water or the washing liquid due to the centrifugal force out of the fabric out through the drum openings is thrown. The drain device 12 is activated in this case, so that the liquid is removed from the tub 2.

In Fig. 3a to 3c the control of the motor 12d of the drain pump 12a according to the inventive method is shown in a diagram. The time points on the time axis t are given here only symbolically, in the real process, these markings correspond to a time unit. At the time t = 1, there is already so much washing liquid 19 in the tub 2, as is provided for the normal washing operation. From the time t = 2, the washing phase Wa is completed and the washing liquid 19 is pumped out of the tub 2, in which the pump 12a of the drain device 12 is activated ( Fig. 3a). Fig. 3c It can be seen that the liquid level within the tub 2 is reduced from the maximum value Max. As soon as the liquid level reaches the minimum Min, the pump 12a is switched off, otherwise there is a risk that the pump 12a runs dry or draws in air, which would lead to undesirable noise. At the time t = 2a, the spinning begins, wherein the drum 3 is rotated at a steady or unsteadily increasing speed. ( Fig. 3b ). In Fig. 3c can be seen that the liquid level increases in the tub despite activated drain pump 12a, as at the beginning of the spin phase Sc very much liquid from the still heavily liquid-washed laundry items 8 exits. At the time t = 3, a critical level Krit is detected, so that the drain pump 12d from this time t = 3 with an increased flow rate, the boost, is operated. The spin-up is continued, as the liquid level drops due to the increased flow rate. From the time t = 3a, the limited period TB is over, then the pump 12a is switched back from the boost mode to the nominal mode. The level now rises more slowly, because from the laundry 8 a large part of the liquid was driven out. From the time t = 4, the delivery rate of the pump 12a in nominal operation is even higher, as liquid is expelled from the laundry 8, so that the level drops. Upon reaching the lower limit Min, the pump 12a is turned off to prevent dry running of the pump 12a.

This control behavior is achieved in that the frequency converter 16, which energizes the pump motor 12d, receives the commands from the control device 18 by means of a signal connection or data connection in order to operate the pump motor 12d in a demand-oriented manner as a function of the conditions occurring in the washing process.

The in Fig. 3a to 3c said sequence is suitable in a corresponding manner for the operation of a circulating pump 17a, for example, if the Umflutbetrieb associated with a centrifugal operation, in which the drum 3 at a speed above the Startup speed is rotated and for a limited period of increased delivery capacity of the bypass pump 17a is required.

The method may also be used in accordance with the operation of the circulating pump and / or the drain pump in a dishwasher.

Claims (10)

1. Method for operating a pump (12a, 17a) with an electronically commutated motor (12d, 17d) for a flow device (17) or discharge device (12) in a washing machine, comprising a suds container (2) for receiving washing liquid (19) for treating material (8) inside the suds container (2), the method including at least one washing stage (WA) in which washing liquid (19) is located in the suds container (2), a discharge away from the suds container (2) being carried out by means of the discharge device (12) at the end of the washing stage, characterised in that the capacity of the pump (12a, 17a) is varied depending on the level (Min, Krit) of the washing liquid (19) in the suds container (2), said level being detected by a sensor (20).
2. Method according to claim 1, characterised in that when the washing liquid (19) in the suds container (2) exceeds a predetermined upper level (Krit), the capacity of the pump (12a, 17a) is increased, at least for a predetermined period of time (TB), with respect to a nominal capacity of the pump (12a, 17a).
3. Method according to claim 1, characterised in that when a lower level (Min) is not reached, the capacity of the pump (12a, 17a) is reduced with respect to a nominal capacity of the pump (12a, 17a).
4. Method according to either claim 1 or claim 2, characterised in that the increase and/or reduction in the capacity takes place in stages.
5. Method according to either claim 1 or claim 2, characterised in that the increase and/or reduction in the capacity takes place continuously.
6. Method for operating a washing machine (1) according to any of claims 1 to 5, the washing machine (1) comprising a drum (3) that is rotatably mounted in a horizontal or an inclined manner inside the suds container (2) and is driven by a motor (13), the method including a spinning stage (Sc) for draining the laundry items (8), characterised in that the capacity is increased or reduced during the spinning stage (Sc) depending on the detected level (Min, Krit) of the washing liquid (19) inside the suds container (2).
7. Method according to any of claims 2 to 6, wherein the predetermined period of time (TB) in which the capacity of the pump (12a, 17a) is increased is in the range of 3 to 15 seconds.
8. Mechatronic system, comprising

   - a frequency converter (16) for supplying current to at least one electronically commutated motor (12d, 17d) for driving a pump (12a, 17a) for transporting washing liquid (19) in a water-conducting appliance (1), which frequency convertor is configured to supply increased electrical power in the form of an increased voltage, current and/or frequency to the motor (12d, 17d) for a predetermined period of time (TB), said power being suitable for increasing the capacity of the pump (12a, 17a) for the predetermined period of time (TB), the predetermined period of time (TB) for the increased electrical power being able to be supplied to the frequency converter (16) by means of a signal or a piece of data, in order to operate the motor (12d) as required according to the conditions occurring in the washing process,

   - at least one motor (12d, 17d) for driving a pump (12a, 17a), the motor (12d, 17d) being a permanent-magnet synchronous motor, characterised by

   - a further electronically commutated motor (17d) for driving a pump (17a), the frequency converter (18) being configured to supply one of the two motors (12d, 17d) with increased electrical power for a predetermined period of time, and the other motor (17d, 12d) with no more than nominal power.
9. Washing machine (1) comprising a suds container (2) for receiving washing liquid (19) for treating laundry (8), a drum (3) that is rotatably mounted in a horizontal manner in the suds container (2), a motor (13) for rotating the drum (3), a heating member (7), a discharge device (12) having a mechatronic system, comprising

   - a frequency converter (16) for supplying current to at least one electronically commutated motor (12d, 17d) for driving a pump (12a, 17a) for transporting washing liquid (19) in a water-conducting appliance (1), which frequency converter is configured to supply increased electrical power in the form of an increased voltage, current and/or frequency to the motor (12d, 17d) for a predetermined period of time (TB), said power being suitable for increasing the capacity of the pump (12a, 17a) for the predetermined period of time (TB), the predetermined period of time (TB) for the increased electrical power being able to be supplied to the frequency converter (16) by means of a signal or a piece of data, in order to operate the motor (12d) as required according to the conditions occurring in the washing process,

   - at least one motor (12d, 17d) for driving a pump (12a, 17a), the motor (12d, 17d) being a permanent-magnet synchronous motor, a water supply device (15) and a control device (16) for controlling the individual stages (Wa, Sp, Sc) of the chosen washing programme (WP), characterised by

   - at least one sensor (20) for detecting and/or determining the level (Min, Krit) of liquid inside the suds container (2), which is operatively connected to the control device (16), the control device (16) being operatively connected to the frequency converter (18) for actuating the motor (12d, 17d) of the pump (12a, 17a) and is configured to supply the period of time for the increased electrical power supplied to the motor (12d, 17d) to the frequency converter (18) during the spinning stage (Sc) depending on the detected level (Krit, Min) of the washing liquid (19) inside the suds container (2).
10. Washing machine (1) according to claim 9, further comprising a flow device (17) having a flow pump (17a), which is configured to transport washing liquid (19) out of the lower region of the suds container (2) into the upper region, at least temporarily, based on the proper operational position of the washing machine (1), and further comprising a mechatronic system according to claim 9, wherein the further motor (17d) is designed to drive the flow pump (17a).

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