EP3332059B1 - Laundry-care appliance having a circulation system - Google Patents

Description

The present invention relates to a laundry care device with a circulation system.

The disclosure EP 2 754 743 A1 shows a washing machine with a circulation pump.

The disclosure JP 2010 046125 A shows a washing machine with a circulation pump.

In conventional laundry care devices, circulation systems are used to pump washing liquor out of the tub by means of a pump, and to feed the pumped-out washing liquor back into the tub by means of the pump through the circulation system. Here, the wash liquor supplied to the tub is passed directly onto the laundry in the washing drum in order to wet the laundry with wash liquor. If the pump has a constant pumping capacity, the washing liquor is led into the middle of the laundry in the washing drum, as a result of which the washing liquor supplied may not evenly wet the laundry.

It is the object of the invention to provide a laundry care device with a circulation system in which the wetting of the laundry with washing liquor in the washing drum can be improved.

This object is achieved by an object with the features according to the independent claims. Advantageous embodiments are the subject of the dependent claims, the description and the drawings.

According to one aspect, the object according to the invention is achieved by a laundry care device with a rotatably mounted washing drum for receiving laundry, a tub for receiving washing liquor, the tub having an outlet opening and an inlet opening, a circulation system which fluidically connects the outlet opening to the inlet opening, wherein the Circulation system comprises a pump for pumping washing liquor into the washing drum, the pump being designed to pump the washing liquor into the washing drum with different pump pressures within the same washing process in order to vary a location of the washing liquor in the rotating washing drum, the pump being designed Pumping wash liquor into the washing drum within the same washing process with periodically changing pump pressures, the periodically changing pump pressures corresponding to a sinusoidal pump pressure change, the laundry care device comprising a drum drive for driving the washing drum with a rotation frequency, the pump being designed, To pump wash liquor into the washing drum with a pump pressure changing according to a pump frequency, the pump frequency differing from the rotation frequency or from a multiple of the rotation frequency, the pump frequency is lower than the rotation frequency.

This achieves the technical advantage that, due to the changing location of the wash liquor, which is introduced into the rotating washing drum, different areas of the laundry in the rotating washing drum come into contact with washing liquor, so that the laundry is uniformly and thus completely wetted is ensured in the washing drum.

In conventional laundry care devices with circulation systems, the pump is operated at a constant speed during the circulation process, as a result of which a constant flow of wash liquor in the circulation system is obtained. Due to the constant flow of wash liquor, the wash liquor is pumped through the inlet opening with a uniform injection pattern into the wash drum, whereby a constant point of occurrence of the wash liquor supplied in the wash drum is obtained when the wash liquor is at rest. If the washing drum rotates rapidly, the laundry may be pressed against the drum wall of the washing drum due to the centrifugal forces which occur, as a result of which a laundry tunnel can form in the middle of the washing drum. The wash liquor injected through the inlet opening wets the laundry tunnel and is pressed outwards in a radial direction by the laundry due to the centrifugal forces that occur. However, the laundry lying against the front of the washing drum can under certain circumstances only be insufficiently wetted.

In order to obtain complete wetting of the laundry even when the washing drum rotates rapidly, the pump is designed to pump washing liquor into the washing drum with different pump pressures through the circulation system within the same washing process. The different pump pressures result in different flow rates of the wash liquor in the circulation system. Because of the different flow rates of wash liquor, there are therefore different injection patterns of the wash liquor passed through the inlet opening into the wash drum and consequently a different point of occurrence of the injected wash liquor on the laundry in the rotating wash drum.

Thus, a large area of the laundry in the washing drum can come into contact with washing liquor as a result of the changing point of occurrence of the washing liquor introduced onto the laundry in the rotating washing drum, which results in complete washing of the laundry with washing liquor.

A laundry care device is understood to mean a device that is used for laundry care, such as a washing machine or a tumble dryer. Such a laundry care device is understood in particular to mean a household laundry care device. So a laundry care device, which is used in the context of housekeeping, and with which laundry is treated in normal household quantities.
In an advantageous embodiment of the laundry care device, the laundry care device comprises a nozzle which is arranged at the inlet opening, the pump being designed to pump the wash liquor through the nozzle into the washing drum.

This achieves the technical advantage that the nozzle arranged at the inlet opening ensures a particularly effective introduction of the washing liquor into the washing drum. The nozzle has an advantageous shape to effectively redirect the liquid flow of the wash liquor pumped through the nozzle, whereby the wash liquor can effectively wet the laundry in the washing drum. The circulation system is fluidly connected to the inlet opening and the nozzle arranged at the inlet opening, so that the pump pumps wash liquor through the nozzle at different pump pressures, as a result of which the wash liquor pumped through the nozzle is directed into the washing drum with different injection patterns.

According to the invention, the pump is designed to pump wash liquor into the washing drum within the same washing process with pump pressures that change periodically over time, the pump pressures that change periodically over time corresponding in particular to a sinusoidal pump pressure change.
This achieves the technical advantage that a periodic change in the pump pressures of the pump can advantageously be realized by correspondingly controlling the pump drive, which enables advantageous control of the changing point of occurrence of the wash liquor in the rotating washing drum. In particular, the periodic change in the pump pressure can cause the wash liquor to appear in the washing drum at the same time changes periodically, whereby a uniform distribution of the wash liquor on the laundry is achieved.

In a further advantageous embodiment of the laundry care device, the circulation system comprises a circulation hose which fluidically connects the drain opening to the inlet opening, the pump being connected to the circulation hose in order to pump wash liquor through the drain opening out of the tub into the circulation hose and the pumped wash liquor out of the Pump the circulation hose through the inlet opening into the washing drum.

This achieves the technical advantage that the circulation hose of the circulation system enables an effective circulation of washing liquor from the tub in the circulation hose and from the circulation hose into the washing drum, which enables an effective supply of washing liquor to the laundry in the washing drum.

In a further advantageous embodiment of the laundry care device, the laundry care device comprises a pump drive for driving the pump and a controller for controlling the pump drive, the controller being designed to operate the pump drive at a first speed during a first time interval of the washing process in order to wash water during the first Pumping time interval with a first pump pressure in the washing drum, and wherein the controller is designed to operate the pump drive at a second speed, which is different from the first speed, during a second time interval following the first time interval, to wash water during the second Pump time interval with a second pump pressure, which is different from the first pump pressure, in the washing drum.

This has the technical advantage that changing the speed of the pump drive and the resulting change in pump pressure, the resulting change in the flow of wash liquor in the circulation system, and the resulting change in the spraying behavior of the wash liquor into the washing drum effective change of the location of the wash liquor is achieved in the rotating washing drum.

According to the invention, the laundry care device comprises a drum drive for driving the washing drum with a rotation frequency, and the pump is designed to pump washing liquor into the washing drum with a pump pressure that changes according to a pumping frequency, the pumping frequency being dependent on the rotation frequency or a multiple of the rotation frequency different.
This has the technical advantage that the different values of the pumping frequency of the pump and the rotation frequency of the washing drum ensure that the changing point of occurrence of the washing liquor pumped into the washing drum by the pump is directed to a large area of the drum shell of the washing drum. The pump frequency of the changing pump pressure of the pump, which differs from the rotation frequency of the washing drum, ensures that different wetting paths on the surface of the washing drum are traversed by the introduced washing liquor during different revolutions of the washing drum. This ensures complete wetting of the laundry in the washing drum.

According to the invention, the pump frequency is lower than the rotation frequency.
This achieves the technical advantage that the low pumping frequency ensures that the laundry is advantageously wetted in the washing drum. During a change in the pump pressure by the pump, the washing drum rotates several times under the introduced wash liquor jet several times. Thus, different areas of the laundry in the washing drum are wetted each time the pump pressure changes.
In a further advantageous embodiment of the laundry care device, the pump can be deactivated during a period of the washing process in order to stop the pumping of wash liquor into the washing drum during the period.

This achieves the technical advantage that the pump is designed to stop the pumping of washing liquor into the washing drum during the period of time, so that the washing present in the washing drum can be sufficiently flooded by washing liquor already present in the washing drum, thereby uniformly wetting the laundry is achieved.

In a further advantageous embodiment of the laundry care device, the laundry care device comprises a fill level sensor which is designed to detect a fill level of wash liquor in the suds container, the pump being designed to change the pump pressure as a function of the detected fill level of wash liquor.

This achieves the technical advantage that the pump pressure of the pump can be changed as a function of the detected fill level of the wash liquor in the tub, thereby ensuring that the pump pressure can be adapted to the amount of wash liquor in the tub not bound to the laundry , This ensures that the pump does not have to be switched off when the wash liquor level is low, or that the tub is not pumped empty.

In a further advantageous embodiment of the laundry care device, a flow sensor is arranged in the circulation system, which is designed to detect a flow rate of wash liquor in the circulation system, the pump being designed to change the pump pressure as a function of the detected flow rate of wash liquor.

This has the technical advantage that the pump pressure can be changed as a function of the detected flow rate of wash liquor in the circulation system, in particular in the circulation hose, thereby ensuring that the pump pressure can be adapted to the detected flow rate of the wash liquor. This ensures that in the event of a possible blockage in the circulation system and a resulting reduction in the flow rate, the pump pressure of the pump can be changed accordingly in order to ensure an effective circulation of the wash liquor in the circulation system.

In a further advantageous embodiment of the laundry care device, the inlet opening is arranged on a front side or on an upper side of the suds container, and the outlet opening is arranged on an underside of the suds container.

This achieves the technical advantage that the corresponding positioning of the drain opening and the inlet opening on the tub enables an effective drainage of washing liquor from the tub, or an effective supply of washing liquor into the tub. The inlet opening is located on a top or on a front of the laundry care device, e.g. in the vicinity of a sleeve arranged on the tub, thereby allowing washing liquor to circulate effectively in the circulation system.

In a further advantageous embodiment of the laundry care device, the washing drum comprises a device for moving laundry in the washing drum or a device for moving washing liquor in the washing drum.

This has the technical advantage that the device for moving laundry in the washing drum or the device for moving washing liquor in the washing drum, such as e.g. Laundry driver, the wetting of the laundry in the washing drum with wash liquor is improved. When the washing drum rotates, items of laundry get caught in the device for moving laundry in the washing drum and are carried along by the washing drum in the direction of rotation of the washing drum. Likewise, wash liquor can be moved in the direction of rotation of the wash drum by the device for moving wash liquor.

In a further advantageous embodiment of the laundry care device, the circulation system comprises a recess for depositing contaminants.

This achieves the technical advantage that impurities can be collected in the depression of the circulation system, as a result of which these can subsequently advantageously be removed from the circulation system.

In a further advantageous embodiment of the laundry care device, the laundry care device comprises a filter unit, the filter unit being arranged in the circulation system, and the filter unit preferably comprising a foreign body trap for removing foreign bodies.
This achieves the technical advantage that foreign bodies, such as impurities, can be effectively removed from the circulation system by the filter unit or foreign body trap.
According to a second aspect of the invention, the object is achieved by a method for varying a point of occurrence of wash liquor in a rotating washing drum in a laundry care device, the laundry care device comprising the rotatably mounted washing drum for receiving laundry, a tub for receiving washing liquor, and the tub has a drain opening and an inlet opening, and comprises a circulation system which fluidically connects the drain opening to the inlet opening, the circulation system comprising a pump for pumping wash liquor into the washing drum, the method comprising pumping wash liquor within the same washing process with different pump pressures into the washing drum in order to vary a point of occurrence of the washing liquor in the rotating washing drum, the pump being designed to wash liquor within the same washing process with periodically changing pump pressures n to be pumped into the washing drum, the periodically changing pump pressures corresponding to a sinusoidal pump pressure change, the laundry care device comprising a drum drive for driving the washing drum with a rotation frequency, the pump being designed, washing liquor with a pump pressure changing in accordance with a pump frequency pump the washing drum, the pumping frequency being different from the rotation frequency or a multiple of the rotation frequency, the pumping frequency being less than the rotation frequency.

Fig. 1

eine schematische Ansicht eines Wäschepflegegeräts;

Fig. 2

eine schematische Ansicht eines Wäschepflegegeräts mit einem Zirkulationssystem; und

Fig. 3

einen Ablauf eines Verfahrens zum Variieren eines Auftrittsorts von Waschlauge, welche in die Waschtrommel eines Wäschepflegegeräts geleitet wird.

This achieves the technical advantage that by pumping washing liquor with different pump pressures and the resulting different flows of washing liquor in the circulation system, a different spraying behavior of the washing liquor introduced into the washing drum is achieved, as a result of which the washing liquor occurs in the rotating washing drum can be varied to ensure advantageous wetting of the laundry in the washing drum.
Further exemplary embodiments are explained with reference to the attached drawings. Show it:

Fig. 1

a schematic view of a laundry care device;

Fig. 2

a schematic view of a laundry care device with a circulation system; and

Fig. 3

a sequence of a method for varying a location of wash liquor, which is passed into the washing drum of a laundry care device.

Figure 1 shows a schematic view of a general laundry care appliance 100, such as a washing machine. The laundry care device 100 comprises a induction bowl 101, into which washing care substance, such as, for example, detergent, can be filled. The laundry care device 100 comprises a door 103 for loading the laundry care device 100 with laundry.

Figure 2 shows a schematic view of a laundry care device with a circulation system. The laundry care device 100 comprises a circulation system 105, as well as a washing drum 107 for receiving laundry, a tub 109 for receiving washing liquor, which has an inlet opening 111 and a drain opening 113. The inlet opening 111 and the outlet opening 113 are fluidly connected by a circulation hose 115, the circulation hose 115 being connected to a pump 117. Arranged at the inlet opening 111 is a nozzle 118 which is designed to guide washing liquor into the washing drum 107 and, if appropriate, to wet laundry present in the washing drum 107. The pump 117 is designed to pump wash liquor through the drain opening 113 from the tub 109 into the circulation hose 115 and to pump the pumped wash liquor out of the circulation hose 115 through the inlet port 111 and through the nozzle 118 into the tub 109 again. The laundry care device 100 further comprises a pump drive 119 for driving the pump 117.

The use of the circulation system 105 optimizes the washing liquor transport in the laundry care device 100. Through the inlet opening 111 on a sleeve arranged on the tub 109, the washing liquor conveyed in the circulation system 105 is pumped through the nozzle 118 directly onto the laundry in the washing drum 107. When the washing drum 107 is fully loaded, the washing liquor injected into the washing drum 107 through the nozzle 118 can be removed from the laundry bounce off and run back into the tub 109 without completely flooding the laundry.

If the washing drum 107 is rotated very quickly, the laundry is pressed against the drum wall of the washing drum 107 due to the centrifugal forces which occur, as a result of which a laundry tunnel is formed in the washing drum 107. The wash liquor is pumped by the pump 117 through the circulation hose 115 to the nozzle 118 and then introduced into the washing tunnel which forms in the washing drum 107. In conventional laundry care devices 100, the pump drive 119 of the pump 117 is operated at a constant rotational speed, as a result of which a constant flow of the wash liquor is provided in the circulation system 105 while the wash liquor is being pumped around. When the washing liquor is introduced into the washing drum 107 through the nozzle 118, the laundry in the middle of the washing tunnel forming in the washing drum 107 is advantageously wetted, and, due to the centrifugal forces that occur, the washing in the washing drum 107 is flooded in a way away from the washing tunnel outward radial direction. In a conventional injection mode, the laundry lying on the end of the tub 109 is insufficiently wetted, since the constant point of occurrence of the wash liquor jet directed through the nozzle 118 into the washing drum 107 is directed at the center of the washing tunnel in the washing drum 107 when the pump pressure of the pump 117 is constant ,

In the present invention, the pump 117 is designed to pump the wash liquor with different pump pressures through the circulation system 105, or through the circulation hose 115, through the inlet opening 111 and through the nozzle 118 into the rotating washing drum 107 within the same washing process. The change in the pump pressure of the wash liquor pumped by the pump 117 in the circulation system 105 leads to correspondingly different flow rates of the wash liquor conveyed by the pump 117 in the circulation system 105. If the wash liquor conveyed in the circulation system 105 is passed through the nozzle 118 into the wash drum 107, the different delivery flows of the wash liquor in the circulation system 105 lead to a correspondingly different injection behavior of the wash liquor into the wash drum 107 through the nozzle 118 and thereby to one vary accordingly The point of occurrence of the wash liquor in the rotating washing drum 107. In the case of a rotating washing drum 107, almost any area of the washing drum 107 can be controlled by changing the point of occurrence of the washing liquor fed into the washing drum 107, and thereby laundry located in the washing drum 107 completely with washing liquor be wetted.

The laundry care appliance 100 further comprises a controller 121, which is connected to the pump drive 119 by a control connection 123 and is designed to control the pump drive 119, in particular to change the speed of the pump drive 119. A change in the speed of the pump drive 119 also changes the pump pressure caused by the pump 117 when pumping wash liquor through the circulation system 105. The pump 117 can pump the wash liquor into the washing drum 107 with periodically changing pump pressures, the periodically changing pump pressures corresponding in particular to a sinusoidal pump pressure change.

Due to the time-changing location of the injected wash liquor in the washing drum 107, in particular in the case of a rotating washing drum 107, and when the frequency of rotation of the washing drum 107 is known, the pump pressure of the pump 117 can be changed in such a way that when the washing drum 107 rotates completely in time almost exactly one sine wave of the change in pump pressure is complete, but not exactly one. It is thereby achieved that, when the washing drum 107 rotates again, the laundry tunnel of the laundry in the washing drum 107 is sprayed offset to the first round trip. For this reason, it is advantageous to select the pump frequency of the pump 117 differently with regard to the rotation frequency or a multiple of the rotation frequency of the washing drum 107, since at identical frequencies, otherwise exactly the same wetting path as in the rotations of the washing drum 107 is followed beforehand.

Due to the time-changing pump pressure of the pump 117 and the resulting time-changing point of occurrence of the wash liquor passed through the nozzle 118 into the washing drum 107 on the laundry in the washing drum 107, for example, soiling such as blood, which tends to be difficult to remove when the moisture is uneven to be washed out better become. As a result, a significant improvement in washing performance can be achieved overall. As a result, the wetting times can be reduced, whereby the overall program duration of the washing process can also be shortened. Lower levels of washing liquor during washing enable a better ecological assessment in the label device assessment, since less energy is required to heat the smaller amount of liquid in the washing liquor not bound to the laundry. Therefore, less energy and, above all, less time is required when the wash liquor is heated to the same predetermined process end temperature, so that a program time reduction is also achieved with this measure.

Figure 3 shows a sequence of a method for varying the point of occurrence of wash liquor which is passed into the washing drum of a laundry care device, the laundry care device according to Figure 2 is described.

The method 200 comprises, as a method step, pumping 201 of washing liquor into the washing drum 107 with different pump pressures within the same washing process in order to vary a location of the washing liquor in the rotating washing drum 107.

All of the features explained and shown in connection with individual embodiments of the invention can be provided in different combinations in the subject matter of the invention in order to simultaneously realize their advantageous effects.

The scope of the present invention is given by the claims and is not limited by the features explained in the description or shown in the figures.

LIST OF REFERENCE NUMBERS

100

Laundry care device

101

dispenser tray

103

door

105

circulation system

107

washing drum

109

tub

111

inlet port

113

drain hole

115

circulation hose

117

pump

118

jet

119

pump drive

121

control

123

control connection

200

Process for varying the location of wash liquor

201

Process step: Pumping wash liquor within the same washing process with different pump pressures

Claims (12)

1. Laundry care appliance (100) having a rotatably mounted washing drum (107) for accommodating laundry, a tub (109) for accommodating water, wherein the tub (109) has an outlet opening (113) and an inlet opening (111), and a circulation system (105) which fluidically connects the outlet opening (113) to the inlet opening (111), wherein the circulation system (105) comprises a pump (117) for pumping water into the washing drum (107), wherein the pump (117) is designed to pump the water into the washing drum (107) at different pump pressures within the same washing operation, in order to vary a location of the water in the rotating washing drum (107), characterised in that the pump (117) is designed to pump water into the washing drum (107) within the same washing operation at periodically changing pump pressures, wherein the periodically changing pump pressures correspond to a sinusoidal pump pressure change, wherein the laundry care appliance (100) comprises a drum drive for driving the washing drum (107) at a rotational frequency, wherein the pump (117) is designed to pump water into the washing drum (107) at a pump pressure changing in accordance with a pump frequency, wherein the pump frequency differs from the rotational frequency or from a multiple of the rotational frequency, wherein the pump frequency is less than the rotational frequency.
2. Laundry care appliance (100) according to claim 1, characterised in that the laundry care appliance (100) comprises a nozzle (118) which is arranged at the inlet opening (111), wherein the pump (117) is designed to pump the water through the nozzle (118) into the washing drum (107).
3. Laundry care appliance (100) according to one of the preceding claims, characterised in that the circulation system (105) comprises a circulation hose (115) which fluidically connects the outlet opening (113) to the inlet opening (111), in that the pump (117) is connected to the circulation hose (115) in order to pump water through the outlet opening (113) out of the tub (109) into the circulation hose (115) and to pump the pumped water out of the circulation hose (115) through the inlet opening (111) into the washing drum (107).
4. Laundry care appliance (100) according to one of the preceding claims, characterised in that the laundry care appliance (100) comprises a pump drive (119) for driving the pump (117) and a controller (121) for controlling the pump drive (119), in that the controller (121) is designed to operate the pump drive (119) at a first speed during a first time interval of the washing operation, in order to pump water into the washing drum (107) at a first pump pressure during the first time interval, and in that the controller (121) is designed to operate the pump drive (119) at a second speed, which is different from the first speed, during a second time interval following on from the first time interval, in order to pump water into the washing drum (107) during the second time interval at a second pump pressure which is different from the first pump pressure.
5. Laundry care appliance (100) according to one of the preceding claims, characterised in that the pump (117) can be deactivated during a time period of the washing operation in order to stop water being pumped into the washing drum (107) during the time period.
6. Laundry care appliance (100) according to one of the preceding claims, characterised in that the laundry care appliance (100) comprises a level sensor, which is designed to detect a level of water in the tub (109), wherein the pump (117) is designed to change the pump pressure as a function of the detected level of water.
7. Laundry care appliance (100) according to one of the preceding claims, characterised in that a flow sensor is arranged in the circulation system (105), and is designed to detect a flow rate of water in the circulation system (105), wherein the pump (117) is designed to change the pump pressure as a function of the detected flow rate of water.
8. Laundry care appliance (100) according to one of the preceding claims, characterised in that the inlet opening (111) is arranged on a front or on an upper side of the tub (109) and in that the outlet opening (113) is arranged on an underside of the tub (109).
9. Laundry care appliance (100) according to one of the preceding claims, characterised in that the washing drum (107) comprises a device for moving laundry in the washing drum (107) or a device for moving water in the washing drum (107).
10. Laundry care appliance (100) according to one of the preceding claims, characterised in that the circulation system (105) comprises a depression for depositing impurities.
11. Laundry care appliance (100) according to one of the preceding claims, characterised in that the laundry care appliance (100) comprises a filter unit, wherein the filter unit is arranged in the circulation system (105), and in that the filter unit preferably comprises a foreign body trap for removing foreign bodies.
12. Method (200) for varying a location of water in a rotating washing drum (107) in a laundry care appliance (100), wherein the laundry care appliance (100) comprises the rotatably mounted washing drum (107) for accommodating laundry, a tub (109) for accommodating water, wherein the tub (109) has an outlet opening (113) and an inlet opening (111), and a circulation system (105) which fluidically connects the outlet opening (113) to the inlet opening (111), wherein the circulation system (105) comprises a pump (117) for pumping water into the washing drum (107), wherein the method (200) comprises the pumping (201) of water into the washing drum (107) at different pump pressures within the same washing operation, in order to vary a location of the water in the rotating washing drum (107), characterised in that the pump (117) is designed to pump water into the washing drum (107) within the same washing operation at periodically changing pump pressures, wherein the periodically changing pump pressures correspond to a sinusoidal pump pressure change, wherein the laundry care appliance (100) comprises a drum drive for driving the washing drum (107) at a rotational frequency, wherein the pump (117) is designed to pump water into the washing drum (107) at a pump pressure changing in accordance with a pump frequency, wherein the pump frequency differs from the rotational frequency or from a multiple of the rotational frequency, wherein the pump frequency is less than the rotational frequency,
    such that the water is pumped into the washing drum (107) within the same washing operation at periodically changing pump pressures, wherein the periodically changing pump pressures correspond to a sinusoidal pump pressure change, wherein the water is pumped into the washing drum at a pump pressure changing in accordance with a pump frequency, wherein the pump frequency differs from the rotational frequency or from a multiple of the rotational frequency, wherein the pump frequency is less than the rotational frequency.

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