RU2637893C2 - Household appliance for laundry care - Google Patents

Abstract

FIELD: satisfaction of human life necessities.

SUBSTANCE: invention refers to the laundry care device with a device for foam registration in the detergent tank, which includes a pressure recording device designed to register the first fluid pressure in the detergent tank for the first moment time and the second fluid pressure for the second moment of time at a stationary position of the laundry drum, and an identification device for foam determination depending on the first and second fluid pressure, and to a method for foam registration in the laundry care device.

EFFECT: improved device reliability.

15 cl, 5 dwg

Description

Technical field

This invention relates to a laundry care appliance with a metering device for registering foam in a washing solution tank, and to a method for registering foam in a laundry care appliance.

State of the art

Due to the chemical composition and erroneous dosing of detergents by the user during the washing process, an excess of foam often forms in the laundry care appliance. Excess foam produced will deteriorate the wash result and may result in damage to the laundry care appliance itself. Various methods are already known for determining the presence of foam in a laundry care appliance.

DE 19549044 C1 describes a method of washing clothes in a washing machine with a laundry drum configured to be moved in a washing solution tank by controlling an engine during reversal cycles consisting of reversal phases and interruptions in reversal during rotational movements, in which foaming is observed by measuring the pressure and at which, given the pressure parameters in the tank for the washing solution, a signal is generated characterizing this position.

DE 102011052619 A1 relates to a method for recording the position of excessive foaming in a laundry treating device using several components for executing an automatic washing program, including a liquid receiving tank, a drum surrounding the processing chamber and rotatably placed in the tank, a pressure sensor, which communicates with the tank and gives a signal informing about the amount of water in the tank, and a control system that is connected to these components. The method also includes rotating the drum, while the reservoir contains a foamable liquid, recording the time parameters of the oscillation of the signal from the pressure sensor when the drum is rotated, setting the position of excessive foaming if this oscillation exceeds a predetermined threshold value, and changing the work program in accordance with fixed position of excessive foaming.

DE 102007042968 A1 describes a method for recognizing foam in a drum washing machine with a program control system for controlling a program sequence with a drum rotatable in a washing solution tank, with a water supply system, with a washing solution removal system located in the tank for washing solution, with a drive motor for the drum and a sensor for signaling the liquid in the tank for washing solution and possibly containing foam.

DE 102007033492 A1 describes a method for controlling the formation of foam when treating laundry with foam from an aqueous solution of a surfactant in a programmed washing machine having a washing solution drain system with a washing solution pump located in the bottom of the washing solution tank, a rotary drum and a heating device.

Patent document EP 0278239 A1 describes a method for automatically washing laundry in a washing solution tank using detergents dissolved in water, heating energy and mechanical energy in the form of activating a device for mixing laundry in a washing machine, to which a washing solution tank is connected as a level sensor a water pressure sensor that provides at least multi-stage output signals.

Known from the prior art, solutions for accounting for foaming conduct it indirectly, only due to the recorded pressure values during movement of the laundry drum. Pressure measurements during the movement of the laundry drum can provide only limited reliability of the recorded fluid pressure values. With a moving drum for laundry, the influence of fluid movement on the registration of its pressure is possible.

Disclosure of invention

The task underlying the invention is to provide such a device for the care of linen, in which it is possible to detect foaming in the tank for washing solution, in particular, in the initial phase of washing, with increased reliability and preventing the appearance of excess foam.

This problem is solved by objects of the invention having features in accordance with the independent clauses. Preferred embodiments of the invention are the subject of images in the figures, descriptions and dependent items.

According to an aspect of the invention, the problem is solved by a laundry care device with a metering device for registering foam in a washing solution tank, which device includes a pressure metering device for recording a first liquid pressure in a washing solution tank at a first time and a second liquid pressure at a second time with a stationary drum for laundry and includes a determining device for determining the presence of foam depending on the first value of the liquid pressure and the second value of the pressure of the liquid dots. Each liquid pressure is taken into account at a certain point in time when the laundry drum is stationary. The first and second fluid pressure values are recorded, for example, in the same phase of the stop of the laundry drum. In addition, to determine the presence of foam in the tank for washing solution, it is possible to use the registered first and second values of the liquid pressure, without determining the average value of the liquid pressure.

Due to this, a technical advantage is achieved, consisting, for example, in that it is possible to account for the foam generated in the tank for the washing solution with increased reliability, which helps to prevent the appearance of excess foam.

This invention is based on the knowledge of the fact that to determine the presence of foam in the detergent solution tank of the laundry care appliance, it is possible to use the backflow time of washing water to the detergent solution tank with the laundry drum stationary. If there is no foaming, then the raised and sprayed washing water flows back to the bottom of the tank for the washing solution immediately. This, in turn, leads to a rapid increase in the pressure of the liquid in the tank for the washing solution from the first pressure to the second. If, on the contrary, foam formed in the washing phase with the movement of the laundry drum, then with the stationary drum for washing, the washing water takes quite a long time to drain back into the tank for the washing solution. This leads to a slower increase in fluid pressure in the tank for the washing solution from the first pressure to the second.

Under the device for the care of linen is understood, in particular, a household appliance, that is, such a device for the care of linen, which is used for housekeeping and serves to process the laundry in the usual amounts for households. In particular, the laundry care appliance is a washing machine or a washer-dryer.

In a preferred embodiment, the laundry care device includes a calibration device for determining a calibration parameter before recording the first and second liquid pressure. Calibration is possible, for example, during prewash, in which the detergent has not yet been introduced into the wash water. In addition, the calibration parameters may depend on the amount of laundry loaded in the laundry care appliance; after all, the absorbency of different textiles can vary. If the prewash is not performed, it is also possible to pre-set the calibration parameters for different quantities of laundry, provided in the factory settings, or to determine them based on the prewash cycles previously performed.

Due to this, a technical advantage is achieved, consisting, for example, in that it is possible to register the presence of foam with increased reliability, in accordance with the amount of linen in the device for care of linen.

In a further preferred embodiment, the calibration device is configured to record the first reference value of the liquid pressure at the first time point of calibration and the second reference pressure of the liquid at the second time point of calibration without adding surfactants to the wash water. Perhaps a calibration device provided as a separate device or as part of a metering device. The first and second reference fluid pressure values are recorded when the laundry drum is stationary. The first and second reference fluid pressure values at the first or second time point of calibration are recorded in the same way as the first and second liquid pressure at the first or second time point, recorded to determine the presence of foam with washing water containing surfactants . Registration of the first reference value of the fluid pressure at the first instant of calibration time and the second reference value of the fluid pressure at the second instant of calibration time allows the formation of various calibration parameters.

Due to this, a technical advantage is achieved, consisting, for example, in that a direct comparison is possible between the first and second reference values of the fluid pressure at the first and second instants of the calibration time, on the one hand, and the first and second values of the fluid pressure at the first and second instants of time , on the other hand, and this allows us to draw conclusions about the presence of foam.

In a further preferred embodiment, the calibration device is configured to determine the dependence of one of the calibration parameters a, Δtk _o on the first reference value of the fluid pressure for the first time point of calibration and the second reference pressure at the second time point of calibration. To determine the presence of foam, it is possible to determine one or two different calibration parameters (a, Δtk _o ).

Due to this, a technical advantage is achieved, consisting, for example, in that it is possible to determine the presence of foam based on the parameter or calibration parameters. Direct comparison of the recorded fluid pressures or time values with each other is not required.

In a further preferred embodiment, the calibration device is configured to determine one of the calibration parameters as the ratio between the second reference value of the liquid pressure and the first reference value of the liquid pressure. Moreover, the value of the calibration parameter (a), formed as the ratio of the pressure values, is between 1 and 1.5, preferably between 1.3 and 1.4.

Due to this, a technical advantage is achieved, consisting, for example, in that it is possible to determine the presence of foam based on the recorded pressure ratios. A comparison between the absolute values of the recorded fluid pressures is not required.

In a further preferred embodiment, the calibration device is configured to determine one of the calibration parameters as a time interval Δtk _o between the second calibration time and the first calibration time. The time interval between the second calibration time and the first calibration time indicates the necessary time during which the fluid pressure rises from the first reference value to the second reference value if foam does not form.

Due to this, a technical advantage is achieved, consisting, for example, in that it is possible to determine the presence of foam based on the recorded time intervals. Comparison of the recorded time instants with each other is not required, which makes the comparison easier.

In a further preferred embodiment, the metering device is configured to determine a period of time between a first point in time and a second point in time at which the second liquid pressure exceeds the first liquid pressure by a predetermined amount. The set time interval corresponds to the time that is required when the fluid pressure recorded with the drum is stationary increases from the first value to the second. After a certain period of time, a predetermined target value is recorded as the second fluid pressure. As a result of this, it is possible to compare the progress of the pressure increase in the phase with surfactants with the progress of the pressure increase during the prewash phase.

Due to this, a technical advantage is achieved, consisting, for example, in that it is possible to determine the presence of foam based on a comparison of the values of the recorded time interval and the calibration parameter.

In a further preferred embodiment, the metering device is configured to determine a target value based on calibration parameter (a). The second fluid pressure is recorded when it becomes (a) times higher than the first fluid pressure. Therefore, the target value based on calibration parameter (a) corresponds to the product of the first fluid pressure and calibration parameter (a).

Due to this, a technical advantage is achieved, consisting, for example, in that it is possible to determine the presence of foam at a given pressure increase from the first to the second liquid pressure based on the calibration parameter and comparing the values of the recorded time intervals.

In a further preferred embodiment, the metering device is configured to compare a time period Δt with a calibration time period Δto in order to determine the presence of foam. For this, it is possible to determine the time elapsing from the moment of recording the first liquid pressure until the second liquid pressure is reached, in particular, such a second liquid pressure that is increased by a predetermined amount.

Due to this, a technical advantage is achieved, consisting, for example, in that it is possible to determine the presence of foam, made on the basis of the calibration parameter and comparing the values of the recorded time intervals.

In a further preferred embodiment, the metering device is configured to determine a second fluid pressure p2 after registering a first fluid pressure p1 and after a time period Δtk _{o has} elapsed. If, after a time period Δtk _o defined as a calibration parameter, the detected second liquid pressure is less than the second reference pressure value pk2 of the liquid, foam formation occurs. Over the time period Δtk _o due to the formation of foam back, less washing water will drain into the tank for the washing solution than would be without the formation of foam. Therefore, a comparison of the second reference pressure value pk2 of the liquid pressure with the second liquid pressure p2 recorded after the time period Δtk _{o has} elapsed makes it possible to determine the presence of foam.

Due to this, a technical advantage is achieved, consisting, for example, in the fact that the formation of foam can be carried out by comparing the second liquid pressure recorded when using washing water with surfactants and the reference value of the liquid pressure recorded when using washing water, not containing surfactants.

In a further preferred embodiment, the metering device is configured to determine the registration of the foam depending on the ratio of the second fluid pressure p2 to the first fluid pressure p1. If, from the ratio of the value of the second liquid pressure p2 to the value of the first liquid pressure p1, a value is determined that differs from the predetermined pressure ratio, then the presence of foam is determined.

Due to this, a technical advantage is achieved, consisting, for example, in that it is possible to determine the presence of foam by comparing two pressure ratios.

In a further preferred embodiment, the metering device is configured to compare the ratio of the pressure values with the calibration parameter (a) in order to determine the presence of foam. If, from the ratio of the value of the second liquid pressure p2 to the value of the first liquid pressure p1, a value is determined that is less than the established calibration parameter (a), i.e. p2 / p1 <a, then the presence of foam is determined as a result of this.

Due to this, a technical advantage is achieved, consisting, for example, in that it is possible to determine the presence of foam by comparing the pressure ratio during the calibration operation and the pressure ratio during the washing phase.

In a further preferred embodiment, the metering device is configured to register a first liquid pressure and a second liquid pressure conducted in a washing solution tank using washing water containing surfactants. For this, the metering device is connected to a pressure recording device or includes a pressure recording device. The pressure recording device is preferably located in the lower region of the washing solution tank, so that it is possible to register a pressure increase from the first liquid pressure to the second liquid pressure.

In addition, a determining device is connected to, or integrated into one of them, a metering device and a pressure recording device. Registration of the first and second pressure in washing water containing surfactants makes it possible to draw conclusions about the presence of foam.

Due to this, a technical advantage is achieved, consisting, for example, in that it is possible to determine the presence of foam by measuring the pressure of the liquid or the pressure of the liquid after a period of time in the water with surfactants without the need to determine the concentration of detergent dissolved in water for washing.

According to a further aspect of the invention, the problem is solved by a method for registering foam in a laundry care appliance, including the steps of registering a first liquid pressure in a washing solution tank at a first moment of time and a second liquid pressure at a second moment of time with a stationary drum and detecting the presence of foam depending on the first fluid pressure and the second fluid pressure.

The registration of the first and second values of the fluid pressure is performed when the laundry drum is in the same phase. In this case, it is possible to register the first and second liquid pressure values for several phases in which the laundry drum is located, in particular, at the end of the washing phase in which the laundry drum moved and foam was formed. When the laundry drum is stationary, shocks of the pressure recording unit cannot occur, which could affect the measurement result of the recorded liquid pressure or even distort it.

Due to this, a technical advantage is achieved, consisting, for example, in the fact that with a stationary drum for laundry it is possible to take into account the pressure of the liquid with increased reliability.

In a further preferred embodiment, the method includes a calibration operation for determining a calibration parameter, carried out before recording the first and second liquid pressure. Determination of the calibration parameter in water for washing that does not contain surfactants is possible based on the ratio of the first reference pressure pk1 of the liquid pressure to the second reference value pk2 of the liquid pressure in the form of the ratio a = pk2 / pk1 of the pressure values. The determination of the calibration parameter Δtk _{o is} also possible in the form of a time interval Δtk _o between the second calibration time tk2 and the first calibration time tk1.

Due to this, a technical advantage is achieved, consisting, for example, in that it is possible to calibrate before each washing in water containing surfactants, if the calibration is carried out during prewash, with washing water that does not contain surfactants.

Brief Description of the Drawings

Embodiments of the invention are presented in the drawings and are further described in more detail.

Showing:

FIG. 1 is a schematic external view of a laundry care appliance;

FIG. 2 is a schematic inside view of a laundry care appliance;

FIG. 3 is a diagram with a full cycle of a program of a laundry care appliance according to the invention;

FIG. 4 is a fragment of the diagram of FIG. 3, which shows the increase in pressure when the laundry drum is stationary without foam; and

FIG. 5 is a fragment of the diagram of FIG. 4, which shows the increase in pressure when the laundry drum is stationary with the presence of foam.

The implementation of the invention

In FIG. 1 shows an outside view of the laundry care apparatus 100. The laundry care device 100 is a washing machine with menu items 102 and buttons 104 for serving menu items 102. In addition, the laundry care device 100 has a door 106 in the form of a round porthole with a door handle 108 thereon.

In FIG. 2 shows an internal view of the laundry care apparatus 100. In the interior of the laundry care apparatus 100 is a laundry drum 117, which is surrounded by a washing solution tank 115. Along the inner side surface of the laundry drum, laundry grippers 114 are provided for gripping laundry from the wash water 125. The pressure recording device 110 allows you to register the fluid pressure in the tank 115 for the washing solution. The pressure recording device 110 is connected to a metering device 130 located in the upper region of the laundry care appliance. The metering device is used to control and manage individual technological operations during the washing process. Therefore, the metering device 130 is connected, in addition, to the drive motor 112, the water supply system 116 and the water pump 124 for washing the laundry care appliance 100. In addition, a determining device 119 is integrated into the metering device 130, which determines the calibration parameters a, Δtk _o . It is possible to record the calibration parameters a, Δtk _o after determining them by means of the accounting device 130.

In FIG. 3 shows the progress of the entire washing cycle, with prewash, in the appliance 100 for care of linen. The time on the abscissa axis is 150, and on the ordinate axis the recorded fluid pressure 170 in units of 140 pressure. In addition, the progress of the rotation speed 160 of the drum 117 for laundry over time 150 is shown.

In FIG. 4 shows a fragment of FIG. 3, which shows the prewash phase without foam. During the prewash in the laundry care appliance 100, the laundry to be washed is moistened with washing water 125 in which the detergent is not dissolved. Consequently, the laundry is moistened with washing water 125 without surfactants, while the laundry drum 117 is in motion at a speed of 160. In the stop phase 180, while the laundry drum 117 is stationary, the speed 160 of the laundry drum 117 is lowered to zero. During a stop 180 with the laundry drum 117 stationary, the first reference pressure pk1 recorded at the first calibration time tk1 rises when the second calibration time tk2 is reached to an increased second reference pressure pk2. The time interval between the first calibration time tk1 and the second calibration time tk2 is defined as the calibration parameter Δtk _o . The further calibration parameter (a) is determined according to the formula a = pk2 / pk1 as the ratio of the second reference pressure pk2 to the first reference pressure pk1. By recording the time interval Δtk _o during which the pressure rises from the first reference pressure pk1 to the second reference pressure pk2 increased in accordance with the calibration parameter (a), it is possible to determine the rate of change of pressure.

In FIG. 5 shows another fragment of FIG. 3, which shows the recorded values of the pressure 170 and the number of revolutions 160 in the washing phase with a moving laundry drum 117 and with a stationary laundry drum 117. With the beginning of the phase 180 of the stationary position of the drum 117 for laundry through the pressure recording device 110 connected to the metering device 130, the first liquid pressure p1 is recorded at the first time t1. At this point, the laundry drum is in the stopped position 180, at which the rotation speed 160 of the laundry drum 117 has dropped to zero. The second fluid pressure p2 is recorded at the second time t2. As soon as the laundry care device 100 transitions from the stationary laundry drum phase 180 to the washing phase with the moving laundry drum 117, the detected liquid pressure 170 in the washing solution tank 115 decreases to a certain liquid pressure value due to the fact that with the movement of the drum 117 for laundry water for washing rises.

The various modes of operation of the laundry care appliance 100 are described below, based on which it is possible to determine the presence of foam.

In the first mode of operation, to determine the value of the calibration parameter, the laundry drum 117 is stopped after the wetting phase for washing without surfactants so that it enters phase 180 with the stationary laundry drum. Upon reaching the stop position 180, the pressure recording device 110 registers the first reference fluid pressure value pk1 at the first calibration time tk1. Upon reaching the second reference pressure value pk2 of the liquid pressure, which corresponds to an increase in the reference pressure value of the liquid pressure by a factor of two, at the second instant of calibration time tk2, the calibration parameter (a) and the time period required to achieve the increased reference value of the liquid pressure are determined as the calibration parameter Δtk _o .

In the phase of washing with water containing surfactants, after the phase with the movable laundry drum 117, the latter is transferred to the stationary drum phase. Upon reaching the stopping position 180 of the laundry drum 117, a first fluid pressure p1 is determined. When, after a lapse of time, the liquid pressure, having increased by a (calibration parameter) times, reaches the second value p2 = a * p1 of the liquid pressure, the time interval until the second liquid pressure p2 is reached is recorded. To assess the presence of foam, the calibration parameter Δtk _{o is} compared with the recorded time interval Δt. If it is registered that Δt> Δtk _o is true, the presence of foam is fixed.

In the second mode of operation, to determine the calibration parameter after the wetting phase of the washing liquid containing no surfactants, the laundry drum 117 is stopped to enter phase 180 with the stationary laundry drum. Upon reaching a stationary position 180, the recording device 110 registers the first reference value pk1 of the fluid pressure at the first calibration time tk1. When the second reference pressure value pk2 of the liquid pressure is reached, which corresponds to the shelf а and the increased reference value of the liquid pressure, at the second instant of calibration time tk2, the calibration parameter (a) and the time period required to achieve the increased reference value of the liquid pressure are determined as the calibration parameter Δtk _o .

In the washing phase with surfactants, after the phase with the movable laundry drum 117, it is transferred to the stationary drum phase. Upon reaching the stopping position 180 of the laundry drum 117, a first fluid pressure value p1 is recorded. After the time period Δtk _o , an increased second liquid pressure p2 is recorded. To assess the presence of foam, determine the ratio of pressure values - the ratio of the second liquid pressure p2 to the first liquid pressure p1 and compare it with the calibration parameter (a). If it is registered that p2 / p1 <a is true, the presence of foam is fixed.

In the third mode of operation in the washing phase with surfactants, after the phase with the movable laundry drum 117, it is transferred to the stationary drum phase. The calibration parameter Δtk _o , the time during which when washing without surfactants the first reference value pk1 of the liquid pressure increases to the second reference value pk2 of the liquid pressure, is predefined in the metering device 130. In this case, the second reference value pk2 of the liquid pressure is the value increased by a factor of time, or the condition is fulfilled: p2 = p1 * a.

In the phase of washing with water with surfactants after the phase with a movable drum 117 for linen, it is transferred to the phase with a stationary drum. Upon reaching a stationary position 180 of the drum 117 for linen is determined by the first value p1 of the liquid pressure. If the fluid pressure reaches a value increased by a (calibration parameter) times, i.e. the second pressure p2 = a * p1 of the liquid, the period of time elapsed before the second pressure p2 of the liquid is reached is recorded. To assess the presence of foam, a predetermined calibration parameter Δtk _{o is} compared with the recorded time interval Δt. If it is registered that Δt> Δtk _o is true, the presence of foam is fixed.

The described operating modes for detecting the presence of foam are carried out when the laundry drum is stationary, and their implementation is possible during the early or late phase of washing in the appliance for the care of linen. The determination of average fluid pressure values for determining the presence of foam is not required. Thus, a laundry care device and a care method with a simplified monitoring system for detecting the presence of foam are provided.

In the subject matter of the invention, it is possible that all the features explained and shown in relation to individual embodiments of the invention, in different combinations, are possible in order to simultaneously realize their preferred effects.

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

Designation List

100 laundry care appliance

102 menu items

104 buttons

106 door

108 door handle

110 pressure recording device

112 drive motor

114 clothes

115 tank for cleaning solution

116 water supply system

117 laundry drum

119 determining device

120 calibration device

124 washing water pump

125 washing water

130 metering device

140 pressure

150 time

160 speed

170 recorded fluid pressure

180 stops (phase with the laundry drum stationary)

p1 first fluid pressure

P2 second fluid pressure

tk1 first point in time calibration

tk2 second point in time calibration

t1 first time

t2 second point in time

Δt time period

Δtk _o calibration parameter

and the calibration parameter

Claims (17)

1. A laundry care device (100) with a metering device (130) for registering foam in a tank (115) for a washing solution, including a pressure recording device (110) for detecting a first liquid pressure (p1) in a tank (115) for a washing solution at the first moment of time (t1) and a second pressure (p2) of liquid at the second moment of time (t2) with the drum drum (117) stationary, and a determining device (119) for determining the presence of foam depending on the first pressure (p1 ) fluid and second fluid pressure (p2). 2. A laundry care device (100) according to claim 1, characterized in that the laundry care device (100) comprises a calibration device (120) for determining a calibration parameter (a, Δtо) before registering the first and second liquid pressure. 3. A laundry care device (100) according to claim 1 or 2, characterized in that the calibration device (120) is configured to register the first reference value (pk1) of the liquid pressure at the first time point (tk1) of the calibration and the second reference value (pk2) liquid pressure at the second time point (tk2) calibration, in the presence of washing water that does not contain surfactants. 4. A laundry care device (100) according to claim 3, characterized in that the calibration device (120) is configured to determine one of the calibration parameters (a, Δtk _o ) depending on the first reference value (pk1) of the liquid pressure for the first time point (tk1) of the calibration and the second reference value (pk2) of the pressure at the second time point (tk2) of the calibration. 5. The laundry care device (100) according to claim 4, characterized in that the calibration device (120) is configured to determine one of the calibration parameters (a) as the ratio of the pressure values — the second reference value (pk2) of the liquid pressure to the first reference value (pk1) of fluid pressure. 6. Device (100) for laundry care according to claim. 4, characterized in that the calibration device (120) adapted to determine the calibration parameter (Δtk _o) as a time interval (Δtk _o) between the second point in time (tk2) calibration and first point in time (tk1) calibration. 7. A laundry care device (100) according to claim 6, characterized in that the metering device (130) is configured to determine a time interval Δt between the first time (t1) and the second time (t2) at which the second pressure (p2) fluid exceeds the first fluid pressure (p1) by a predetermined amount. 8. A laundry care device (100) according to claim 7, characterized in that the metering device (130) is configured to determine a target value based on a calibration parameter (a). 9. A laundry care device (100) according to claim 7 or 8, characterized in that the metering device (130) is configured to compare a time period (Δt) with a calibration time period (Δto) for determining the presence of foam. 10. Laundry care device (100) according to claim 9, characterized in that the metering device (130) is configured to determine a second liquid pressure (p2) after registering the first liquid pressure (p1) and after a time period (Δtk _o ) 11. Laundry care device (100) according to claim 10, characterized in that the metering device (130) is configured to determine the registration of the foam depending on the ratio of the pressure values - the second pressure (p2) of the liquid to the first pressure (p1) of the liquid . 12. Laundry care device (100) according to claim 10 or 11, characterized in that the metering device (130) is configured to compare the ratio of pressure values with the calibration parameter (a) for determining the presence of foam. 13. The device (100) for the care of linen according to one of paragraphs. 1, 2, 4-8, 10, 11, characterized in that the metering device (130) is configured to register the first liquid pressure and the second liquid pressure in the tank (115) for the washing solution, in the presence of washing water containing surface active substances. 14. A method for registering foam in a laundry care appliance, characterized by the following operations: - registration of the first liquid pressure in the tank (115) for the washing solution at the first time (t1) and the second liquid pressure at the second time (t2) with the drum drum (117) stationary; and - determining the presence of foam depending on the first liquid pressure and the second liquid pressure. 15. The method according to p. 14, characterized in that the method includes a calibration operation to determine the calibration parameter (a, Δtk _o ) before registering the first and second liquid pressure.

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