Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
  • D06F33/00—Control of operations performed in washing machines or washer-dryers 
  • D06F33/30—Control of washing machines characterised by the purpose or target of the control 
  • D06F33/32—Control of operational steps, e.g. optimisation or improvement of operational steps depending on the condition of the laundry
  • D06F33/42—Control of operational steps, e.g. optimisation or improvement of operational steps depending on the condition of the laundry of draining
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
  • D06F2103/00—Parameters monitored or detected for the control of domestic laundry washing machines, washer-dryers or laundry dryers
  • D06F2103/18—Washing liquid level
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
  • D06F2105/00—Systems or parameters controlled or affected by the control systems of washing machines, washer-dryers or laundry dryers
  • D06F2105/08—Draining of washing liquids
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
  • D06F39/00—Details of washing machines not specific to a single type of machines covered by groups D06F9/00 - D06F27/00 
  • D06F39/08—Liquid supply or discharge arrangements
  • D06F39/083—Liquid discharge or recirculation arrangements
  • D06F39/086—Arrangements for avoiding detergent wastage in the discharge conduit
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
  • D06F39/00—Details of washing machines not specific to a single type of machines covered by groups D06F9/00 - D06F27/00 
  • D06F39/08—Liquid supply or discharge arrangements
  • D06F39/087—Water level measuring or regulating devices

Definitions

• the invention relates to a method for operating a laundry treatment machine and a laundry treatment machine.
• it relates to a method in which a delayed start of the washing routine is conducted.
• laundry treatment machines are for "simple" laundry washing machines (i.e. laundry washing machines which can only wash and rinse laundry) and laundry washing-drying machines (i.e. laundry washing machines which can also dry laundry), or drying machines (i.e. drying machines which can dry laundry).
• Washing machines in households also called domestic washing machines, are well- known and usually are used for washing laundry.
• Washing machines usually comprise washing tubs in which a rotatable drum is housed for receiving goods to be washed, usually laundry. Washing liquid is introduced into the washing tub, which washing liquid consists only of water or mainly of water and detergents
• washing or cleaning agents added to or dissolved in the water for improving the washing quality.
• Laundry treatment machine will refer to simple laundry washing machines or laundry washing-drying machines (washer/dryers).
• Laundry treatment machines such as washing or washing-drying machines generally comprise an external casing provided with a washing tub which contains a rotatable perforated drum where the laundry is placed. A loading/unloading door ensures access to the drum.
• Laundry treatment machines typically comprise a water supply unit and a products supply unit or detergent feeding device, preferably a drawer, for the introduction of water and washing/rinsing products (i.e. detergent, softener, rinse conditioner, etc.) into the tub.
• Known laundry treatment machines are also provided with water draining devices that may operate during different phases of the washing program to drain the dirty water from the tub.
• Washing machines or washing-drying machines typically comprise a detergent dispenser or detergent feeding device, especially a drawer, which comprises at least one compartment for a laundry treatment agent such as detergent, rinsing agent, bleaching agent, softener.
• the detergent feeding device can comprise a compartment or box for both solid (i.e. powder) and liquid treatment agents, usually comprising a flap suitable to retain the liquid in case of liquid treatment agents provided on said compartment. Due to the required tolerances, and to the necessity to wash the bottom of the compartment, a small clearance must to be assured between the flap and the respective compartment; due to this clearance, in case of a delay start, the liquid starts leaking through the flap and starts flowing / dripping into the washing tub.
• Some kinds of machines are provided with a delay start function; said function allows the user to set the start of the laundry treating cycle after a set time has been elapsed; usually, just after the setting of the delay start, the delay time, namely the time set by the user to postpone the start of the laundry treating cycle, triggers from the switch of a machine start command.
• the phase to calibrate a water level sensor including a draining step is provided just before the start of the laundry treating cycle, i.e. before the main washing step; due to the draining step, the liquid detergent provided on said compartment which has dipped already into the tub due to the clearance between the flap and the liquid compartment, is drained in case of a delay start.
• the washing step is then started, less liquid detergent is available for the washing cycle, yielding a laundry treatment with a loss of quality and a reduction of cleaning efficiency.
• the aim of the invention is to provide a method for operating a laundry treatment machine in which a delay start of a washing process is performed without the loss of available liquid detergent into the drawer/tub. It is a further aim of the invention to provide a laundry treatment machine which delivers a washing cycle with delay start with an optimized cleaning efficiency.
• the invention relates to a method for operating a laundry treatment machine comprising a washing tub for receiving laundry to be treated and a detergent feeding device and at least one draining pump connected to the tub, the draining pump being connected to a draining circuit for draining liquid collected in the tub when the draining pump is activated, the method comprising
• the invention is based on the consideration that a problem of known procedures to conduct a delay start is that a liquid laundry treatment agent, especially detergent, is not fully confined in the respective compartment until needed but is slowly dripping into the tub.
• a liquid laundry treatment agent especially detergent
• the water level sensor is calibrated and water is drained from the tub, the treatment agent which has already entered the tub is drained / removed from the tub and is not available for the treatment of laundry.
• the amount of treatment agent needed for an adequate treatment of the laundry is therefore reduced, leading to a low-quality treatment of the laundry. This fact also results in a low-quality estimation of the washing machine by the user.
• the laundry treatment machine is preferably built as a washing machine or a washing/dryer, i.e. a combined washing and drying machine.
• the detergent feeding device is preferably built as a drawer with at least one compartment for a laundry treatment product such as detergent, bleaching agent, rinsing agent, softener.
• the detergent feeding device preferably comprises a compartment suitable for both a liquid treatment product and a powder treatment product, said compartment further comprising a closure means, preferable a movable flap, to close the compartment to collect said liquid treatment product and to open the chamber to collect said powder treatment product.
• the draining of liquid from the tub is preferably conducted as a preparatory step or as a part of a calibration procedure of a water level sensor.
• the delay start of the machine is preferably set by a user.
• the laundry treatment machine comprises a user interface comprising at least one user interface element for setting the delay start.
• at least one display element such as an LCD display is arranged on the user interface to display the delay time which is set.
• a delay interval is set by the user through his interaction with a user interaction element by which a timer /counter is set.
• the user interaction element preferably is built as a button and/or knob located on a user interface on the machine.
• the delay start interval is preferably set by rotating a rotatable knob.
• the button and the knob can be combined in a push-button.
• the delay time interval is set by interacting with keys or buttons on the user interface.
• a delay start absolute time is set by the user which can be achieved by the user interface controls described above.
• the washing step is preferably started without any further action needed by the user.
• the time interval between the activating step and the draining step is small compared to the delay interval, especially less than 1 ⁇ 4 or 1/10 or even smaller.
• the draining step is the next step being performed by the laundry treatment machine after the activating step.
• the draining step is preferably performed entirely before the delay interval starts, i.e. it is preferably completed before start of the delay interval. In other words, preferably the delay interval starts running after the draining step has been performed and completed.
• no further draining of liquid from the tub is performed.
• no further draining of liquid from the tub is performed.
• the draining step is part of a calibrating procedure for calibrating a water level sensor in which a reference level value is determined.
• the reference level preferably corresponds to an empty water level of the tub.
• the water level sensor is a sensor which is configured to measure at least one quantity which can represent in a direct or indirect way the level of water and/or washing liquid in the tub.
• the washing procedure preferably is started based on the determined reference level value of the water level sensor.
• the water level is measured and in a setting step the value of the water level sensor is set to the reference level value representing an empty level of liquid in the tub.
• the measuring and setting steps are advantageously conducted immediately after the draining step.
• an alarm is issued.
• the allowed variations are expressed as a tolerance band which is a parameter band, preferably with a lower and a higher border.
• the alarm can also be issued as described above if behaviour of the signal as a function of time decreases from an expected behaviour by more than a tolerance criterion.
• the alarm is advantageously issued acoustically and/or visually, especially on a display of the washing machine.
• the reference level value is preferably compared with a reference level value obtained in a previous calibration procedure, and whereby an alarm is issued if the new value differs from the old value by more than a predetermined tolerance band.
• the delay time interval is advantageously larger than 10 minutes, especially larger than 1 5 minutes.
• the detergent feeding device comprises at least one compartment adapted to receive liquid detergent, whereby the compartment comprises a closure means with a clearance.
• the detergent feeding device preferably comprises at least one compartment adapted to receive both liquid and powder detergent, whereby the compartment comprises a closure means with a clearance.
• the compartment preferably comprises a movable flap.
• the flap is preferably mounted on hinges in such a way that it can swing to the discharge side of the compartment when water is flushed into the compartment.
• the compartment preferably comprises a removable flap.
• the flap can be preferably removed fully from the compartment and/or holding elements are provided in the compartment to which the user can attach the flap when it is not needed, especially when powder is filled into the compartment.
• the flap is moveable from a first position in which it retains liquid within the compartment to a second position in which it essentially allows a free passage of detergent/liquid from the compartment into the tub.
• the flap preferably provides a clearance at the bottom of the compartment.
• the invention in a second aspect, relates to a laundry treatment machine comprising a washing tub for receiving laundry to be treated and a detergent feeding device and at least one draining pump connected to said tub, said draining pump being connect- ed to a draining circuit for draining liquid collected in said tub when said draining pump is activated, further comprising a control unit in which a method according to one of the previous claims is implemented.
• the detergent feeding device is built as a drawer with at least one compartment for a laundry treatment product.
• the liquid box in the dispenser into which the liquid is filled does not need to have a special seal, by which production costs for the box are reduced.
• FIG. 1 shows a front-loading laundry washing machine in a perspective view
• FIG. 2 shows the laundry washing machine according to FIG. 1 in a perspective view with the casing removed
• FIG. 3 shows the laundry washing machine according to FIG. 1 in another perspective view with the casing removed
• FIG. 4 shows a cross section of the laundry washing machine according to
• FIG. 5 shows a view of a portion of the hydraulic circuit of the laundry washing machine according to FIG. 1 ;
• FIG. 6 shows the laundry washing machine of FIG. 1 with a drawer in an extracted state in a perspective view
• FIG. 7 shows the laundry washing machine according to FIG. 6 with a detailed view of the drawer in a perspective view with a flap in a first position
• FIG. 7a shows the laundry washing machine according to FIG. 6 with a detailed view of the drawer in a perspective view with a flap in a second position;
• a laundry treatment machine 1 which is built as a front-loading washing machine which comprises an external housing or casing 2 comprising two side walls, a front wall, a back wall (not shown) and a top plate.
• Washing machine 1 further comprises a front panel 6b with a user interface 6c, preferably comprising indicators for the current state of the machine and/or user elements.
• Front panel 6b further comprises a user element 6d for interacting with the machine which is preferably built as a rotatable push button.
• an extractable drawer 6a is provided, as described below.
• Compartment 6f preferably comprises a flap 7a which acts as a closing means or element for this compart and which is arranged in compartment 6f at two hinges 7b, 7c. Facing bottom part 8a of compartment 6f, the flap 7a comprises a small clearance 8b. The clearance 8b is required due to tolerances and the necessity to clean / wash the bottom of compartment 6f at the end of the laundry treatment cycle.
• the flap 7a mounted rotatable on hinges 7b 7c allows the passage of water + powder through the recess 7i (see Fig.
• the flap 7a is therefore provided to close, at least partially, the compartment 6f for the collection of the liquid detergent; on the other hand, the flap 7a is movable/removable to open the chamber on the discharge side when the powder detergent is inserted on said compartment.
• the flap 7a is seen in another position to which it can be moved by the user.
• holding elements are provided which keep flap 7a stable in the posi- tion shown.
• compartment 6f is in an optimized configuration to receive powder treatment agent.
• the discharge side of compartment 6f does not need to be closed in the case of powder detergent, thus the flap 7a is not needed to retain powder treatment agent in compartment 6f.
• a liquid detergent compartment can be provided, preferably without a know syphon, having a barrier on the discharge side of the container that must assure a small clearance between the said barrier and the compartment walls.
• Laundry treatment machine 1 comprises an air chamber 25a (see FIG. 2) connecta- ble to a device suited to sense (or detect) the liquid level inside the tub 3, especially a water level sensor (not shown in the FIGs).
• the water level sensor preferably comprises or is built as a water pressure sensor which senses the pressure in the tub 3. From the values sensed by the sensor device it is possible to determine the liquid level of the liquid inside the tub 3.
• laundry treatment machine 1 may preferably comprise (in addition to or as a replacement of the pressure sensor) a level sensor (for example mechanical, electro-mechanical, optical, etc.) adapted to sense (or detect) the liquid level inside the tub 3.
• the supply pipe 1 10 is preferably arranged laterally with respect to the tub 3 and preferably terminates at an upper region of the tub 3. More preferably, the supply pipe terminates at a rear side of the washing tub 3.
• the main pipe 17 connects the bottom region of the tub 3 to the filtering device 12.
• An inlet end 17a of the main pipe is advantageously positioned at the lower point of the tub 3, more preferably at the lower point of the sump 34.
• An outlet end of the main pipe is connected to a front part of the filtering device 12.
• the filtering device 12 may be provided directly in the tub 3, preferably obtained in a single piece construction with the latter. In this case the filtering device 12 is fluidly connected to the outlet of the tub 3, in such a way that water and washing liquid drained from the tub 3 enters the filtering device 12.
• the draining pump 26 is preferably connected to the body of the filtering device 12 (see Fig.5) and conveys the liquid to the outlet pipe 28 through an outlet. Activation of the drain pump 26 drains the liquid, i.e. dirty water or water mixed with washing and/or rinsing products, from the tub 3 to the outside.
• Laundry washing machine 1 preferably comprises a first recirculation circuit 20 adapted to drain liquid from the bottom region 7a of the tub 3 and to re-admit the liquid into a second region 20a, or upper/higher region, of the tub 3; in other words, the outlet 23a of the first recirculation circuit 20 is located at a position higher that the position of the inlet 17a of the first recirculation circuit 20 corresponding to the inlet of the main pipe 17 connected to the bottom side of the tub 3.
• Laundry washing machine 1 advantageously or alternatively comprises a second recirculation circuit 30 or mixing circuit.
• the mixing circuit is adapted to drain liquid from the bottom region of the tub 3 and to re-admit such a liquid (recirculated mixing liquid) into a first region of the tub, which corresponds substantially to the same bottom region of the tub 3.
• the second recirculation circuit 30 is adapted to drain liquid from the bottom of the sump 34 and to re-admit such a liquid (recirculated mixing liquid) again into the sump 34. More preferably, the liquid is re-admitted again into the sump 34 below the heater 10. More preferably, the outlet 34a (see Fig.
• the heater 10 is arranged in the drainage area of the washing machine 1 , whereby near the first and/or the second circulation pump 21 , 31 and/or near the first and/or second circulation pipe a water level in a drainage area is increased by means of a rinsing / spinning phase or a water charge while the heater 10 is turned off, and wherein the water level is increased until the heater 10 is at least partially submerged by washing liquid.
• Laundry washing machine 1 comprises a control unit 27 (see FIG. 2), connected to the various parts of the laundry washing machine in order to ensure its operation.
• the control unit 27 is preferably connected to the water inlet or supply circuit 5 (i.e. to supply valve), the water outlet circuit (i.e. to the draining pump 26), the recirculation circuits 20, 30 (i.e. to the recirculation pumps 21 , 31 ), the heater 1 0 and the electric motor and receives information from the various sensors provided on the laundry washing machine 1 , like possibly the pressure sensor, a temperature sensor, etc.
• the user interface 6c is connected to the control unit, accessible to the user and by means of which the user may select and set the washing parameters, like for example a desired washing program. Usually, other parameters can optionally be inserted by the user, for example the washing temperature, the spinning speed, the load in terms of weight of the laundry to be washed, etc.
• the control unit Based on the parameters acquired by the interface 6c, the control unit sets and controls the various parts of the laundry washing machine 1 in order to carry out the desired washing program.
• FIG. 8 a diagram is shown which represents a laundry treatment cycle with a delay start as known from the art.
• An x-axis 68 represents the time, while an y-axis 66 represents a level of activation or an amount of liquid detergent level, as will be described below.
• a curve 70 represents the activation state of the washing machine.
• a steep flank 72 represents the activation of a delay start mode. The user has filled liquid detergent into a compartment of the dispenser / drawer 6a and has inserted laundry into the drum.
• the user has filled the compartment adapted to receive liquid detergent (preferably having at least a small clearance for the detergent passage toward the tub) or to receive either liquid or powder detergent, preferably with a flap positioned to adapt the compartment to receive liquid (preferably assuring at least a small clearance for the detergent passage toward the tub).
• the user has set a delay time interval or a fixed time at which the machine will prepare to start a washing cycle.
• the user has preferably pushed a start button.
• a curve 82 represents a calibration of the water level sensor, which is preferably built as a water pressure sensor which measures the pressure in a pipe connected to the tub.
• the draining of the tub 3 has performed in such a way that the tub can safely be assumed to not contain more liquid than a prescribed value (small amount of liquid can get soaked by the laundry).
• the signal of the water level sensor in this state of the tub 3 then corresponds to an empty liquid / water level in the tub 3 and can be used for the washing cycle.
• the signal of the water level sensor is observed.
• irregularities in the signal-value as a function of time can be found and identifies as characteristics for a sensor failure.
• a failure of the wash- ing machine can be detected, for instance the inability to empty the tub of liquid, if the signal of the sensor is found to be reliable.
• the signal is preferably evaluated and/or processed, especially it is compared with values which correspond to an expected an regular behavior of level sensor and/or machine. If during a specified time interval during the draining step the signal varies more than a tolerance band and/or its values leave a tolerance band of values, preferably an alarm is issued to the user, which can be done acoustically and/or visually.
• a visual alarm is preferably issued on user interface 6c, especially on a display which is arranged on user interface 6c.
• values of previous calibrations or at least one value of a previous calibration of the sensor is stored.
• the new value of the calibration can be compared with one or more previous values. The comparison can reveal that the sensor signal over time shows systematic or irregular behavior. If the calibrated value differs from more or several values, especially also an average of previous value, an irregular condition is recognized and the user is preferably warned with an alarm as described above.
• a preferable delay time of the described delay start of the washing machine is preferably larger than 10 minutes.
• the method is shown in another preferred embodiment in a flow chart.
• detergent is filled into a compartment of the detergent dispenser.
• the laundry treatment cycle is started.
• the laundry treatment cycle encompasses all steps which follow the activation of the machine by the user, especially by pressing a start button.
• the tub 3 is drained.
• the water level sensor which in the preferred embodiment is a water pressure sensor, is calibrated. The reference level value is reset and set to a new value based on the current pressure value, which corresponds to an empty level of the tub 3.
• step 136 the washing machine waits for the selected delay time interval. After the delay time interval has lapsed, the method continues in block 90a as described above. In a block 152, the laundry treatment cycle ends.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Detail Structures Of Washing Machines And Dryers (AREA)
• Control Of Washing Machine And Dryer (AREA)

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Applications Claiming Priority (1)

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ID=59239912

Family Applications (1)

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Cited By (1)

Citations (5)

• 2017
  • 2017-06-27 EP EP17733821.7A patent/EP3645779B1/de active Active
  • 2017-06-27 WO PCT/EP2017/065897 patent/WO2019001690A1/en unknown
  • 2017-06-27 PL PL17733821.7T patent/PL3645779T3/pl unknown

Patent Citations (5)

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