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
  • D06F34/00—Details of control systems for washing machines, washer-dryers or laundry dryers
  • D06F34/14—Arrangements for detecting or measuring specific parameters
  • D06F34/18—Condition of the laundry, e.g. nature or weight
• • 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
  • D06F2103/02—Characteristics of laundry or load
  • D06F2103/04—Quantity, e.g. weight or variation of weight
• • 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
  • D06F2103/26—Imbalance; Noise 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
• • 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
  • D06F37/00—Details specific to washing machines covered by groups D06F21/00 - D06F25/00
  • D06F37/20—Mountings, e.g. resilient mountings, for the rotary receptacle, motor, tub or casing; Preventing or damping vibrations
  • D06F37/22—Mountings, e.g. resilient mountings, for the rotary receptacle, motor, tub or casing; Preventing or damping vibrations in machines with a receptacle rotating or oscillating about a horizontal axis

Definitions

• the invention relates to a method for determining a loading weight of a vibrating system of a domestic appliance for the care of laundry, in which vibrations of the oscillating system are attenuated by means of at least one shock absorber against a device housing of the household appliance, and wherein by means of a displacement sensor measured values are provided which a displacement indicate the oscillating system with respect to a reference position, and the determination of the loading weight by means of a control device based on the measured values takes place.
• the invention also relates to a domestic appliance for the care of laundry items, which is designed for carrying out such a method.
• the laundry care device includes a detection device which serves to detect an operating parameter, namely in particular a water load of a laundry container.
• the detection device is coupled to a capacitor whose capacitance is correlated with the operating parameter.
• a capacitor a film capacitor is used here, which in contrast to a conventional capacitor has a much smaller space requirement and can be arranged due to its geometric flexibility without much effort in an optimal position within the household appliance. This will improve the detection of the Operating parameters ensured.
• one electrode of the film capacitor are fixed in position to a housing of the household appliance and the other electrode or the counter electrode are fixed in position to the tub. In this way, in addition to determining the water load as a function of the geometric arrangement of the two electrodes, the position or the movement of the tub inside the housing can be determined, whereby a total load of the tub and a static and dynamic imbalance can be determined.
• the document DE 101 04 682 B4 describes a method for measuring the loading and unbalance of the drum of a washing machine, wherein the capacitance curve of a capacitive sensor is measured during a washing process and from this the movement of the tub is determined.
• at least one conductive surface of the sensor is electrically isolated as a capacitive sensor between the tub and the device housing fixed to the housing attached.
• the interest is directed to the determination of the loading or a loading weight of the washing drum of a washing machine, in particular to the detection of the so-called dry mass of laundry items, which are introduced by the user into the laundry drum.
• the commonly used method uses the measurement of the movement of the spring-loaded oscillating system with increasing load for determining the mass in the drum.
• a symmetrical system with a one-dimensional sensor is described in this regard, for example, in the document DE 10 2009 028 772 A1.
• Another method which can also be used for asymmetrical systems for determining a loading amount of a laundry treatment appliance is known from the document DE 10 2006 034 190 A1.
• the use of a displacement sensor for determining the loading weight of a washing machine is furthermore known from the document DE 10 2004 043 838 B3.
• the evaluation of the measured values of the displacement sensor takes place in such a way that the rest position of the oscillating system is detected and stored with the aid of the displacement sensor, and the control is switched into the active mode when the detected values change.
• the detected rest position of the oscillating system is taken into account.
• the determination of the rest position thus takes place here in the time in which the control unit is inactive, that is in sleep mode.
• the displacement sensor is read in at least once again, this value read in under load being subtracted from the value for the rest position detected in sleep mode and the result from this calculation being used as weight for the laundry.
• At least one shock absorber - this is designed in particular as a spring piston friction damper - vibrations of the oscillating system are damped against a housing of the household appliance.
• a displacement sensor By means of a displacement sensor, measured values are provided which indicate a displacement of the oscillating system-in particular in the vertical direction of the domestic appliance-relative to a reference position, ie a relative position with respect to the reference position.
• the determination of the loading weight is carried out on the basis of the measured values by means of an electronic control device, which can be designed, for example, as a digital signal processor.
• a chronological course of the measured values is evaluated by the control device and, based on the chronological progression, a slipping of the shock absorber during loading of the oscillating system is detected is, wherein a caused by the slipping change value of the displacement is determined by the control device and compensated in the determination of the loading weight.
• the invention is based on the finding that the measurement of the load weight in a domestic appliance for the care of laundry items is adversely affected by slippage of a friction lining of the shock absorber. This slippage can occur in particular during the loading process. Another finding is that slippage of the friction lining of the shock absorber generates a typical course of the measured values of the displacement sensor. This typical waveform can detected during the loading process by the control device and interpreted as slippage of the friction lining. If such slipping is detected, an offset value or a change value of the displacement is simultaneously determined and compensated for in the determination of the loading weight.
• the force impressed into the system by the shock absorber is fundamentally dependent on the lowering of the oscillating system.
• the weight of the oscillating system including loading is in equilibrium with the spring forces of a spring assembly and the impressed by the at least one shock absorber forces.
• a change in position is compensated, which results by changing the equilibrium when the at least one shock absorber comes in a non-linear working area and slips.
• the invention has the advantage that the total loading weight can be determined very precisely, since the main disturbing influence of the loading amount - namely the nonlinear damping force - is compensated. It can also be used with a lower stiction spring piston damper, which has particular advantages in terms of noise reduction. Accordingly, costly, speed-dependent dampers, such as oil hydraulic dampers, do not need to be used.
• the slippage of the shock absorber is detected when a change in the displacement of the oscillating system which is greater than a predetermined limit value is detected based on the time profile of the measured values within a time interval of a predetermined length.
• This embodiment is based on the recognition that a large change in the position of the oscillating system within a very short time interval can basically only be caused by the slipping of the shock absorber, but not by the introduction of the laundry items in the laundry drum. If the position of the oscillating system changes abruptly within, for example, two milliseconds, it can be assumed that this change in position is due to the slipping friction lining and not to an additional load. Thus, the slippage of the shock absorber can be detected particularly reliable and the load weight can be precisely determined.
• this can also be implemented in such a way that, based on the chronological course of the measured values, a rate of change as a change in the shift per Time unit is determined by the controller.
• the detection of the slipping of the shock absorber can then be made depending on the rate of change. If the rate of change exceeds a predetermined limit, slippage is detected because it is unlikely that a relatively high rate of change can be caused by the introduction of laundry into the laundry drum.
• a household appliance for the care of items of laundry is understood in particular a washing machine or a washer-dryer.
• the oscillating system comprises in particular a tub, which is supported on the at least one shock absorber and in particular suspended on a spring assembly.
• the oscillating system also includes in particular a laundry drum, which is rotatably mounted in the tub.
• a displacement sensor is understood to mean a sensor which is designed to detect the altitude of the oscillating system.
• This displacement sensor can be based on any physical principle, for example on optical and / or electrical and / or electromechanical and / or electromagnetic effects.
• the output signal of the displacement sensor may be an analog or a digital signal.
• slippage of the shock absorber means a movement or slippage of a friction lining of the damper relative to its friction partner, in particular a cylinder of the damper A1 is described.
• the displacement of the oscillating system is detected by means of the displacement sensor relative to a reference position of the system.
• this reference position can be a rest position of the oscillating system that occurs in an unloaded system.
• This rest position can be detected, for example, after completion of each operating program after unloading the laundry drum.
• a dry mass of laundry items is determined as the load weight, which is introduced into the laundry drum of the oscillating system. This means that the loading weight of the laundry drum is determined before activating an operating program of the household appliance.
• the control device determines the abovementioned change value of the offset, which is compensated in the determination of the loading weight. This can in particular be effected in such a way that the change value of the displacement caused by the slippage is subtracted from a current measured value of the displacement sensor (after slipping) and the loading weight is determined as a function of the subtraction result. A distortion of the load weight can thus be prevented.
• the invention also relates to a domestic appliance for the care of laundry items, comprising a vibrating system including a laundry drum for holding the laundry items, with at least one shock absorber for damping vibrations of the oscillating system against a housing of the household appliance, with at least one displacement sensor for providing measured values indicate a displacement of the oscillating system relative to a reference position, and with a control device for determining a loading weight of the oscillating system on the basis of the measured values.
• the control device is designed to evaluate a time characteristic of the measured values during a loading process of the oscillating system (16), to detect, based on the time course, slippage of the shock absorber during loading of the oscillating system, to determine a change value of the displacement caused by the slipping to compensate for the determination of the loading weight and then to detect slippage, if, based on the time profile of the measured values, a change in the displacement within a time interval of a predetermined length is detected, which is greater than a predefined limit value.
• Figure 1 is a schematic representation of a household appliance according to an embodiment of the invention.
• FIG. 2 shows a dependence of a damping force on a lowering of a swinging system of the domestic appliance
• FIG. and FIG. 3 shows a dependency of a measured loading weight on an actual weight of introduced laundry items, wherein a method according to an embodiment of the invention is explained in more detail.
• FIG. 1 home appliance 1 is a washing machine in the embodiment.
• the household appliance 1 comprises a tub 2, in which a laundry drum 3 is rotatably mounted.
• laundry items 4 which are washed in the household appliance 1 during a care process.
• the tub 2 is suspended by a spring assembly 5 on a device housing 6 of the household appliance 1.
• the spring arrangement 5 comprises a first and a second spring 7, 8, wherein the number of springs can be basically arbitrary.
• the tub 2 is further supported on a damper assembly 9, which includes a first and a second shock absorber 10, 1 1 in the embodiment.
• the shock absorbers 10, 1 1 are in particular friction damper.
• the number of shock absorbers 10, 1 1 used can basically be chosen arbitrarily.
• the damper assembly 9 may also include three or four such shock absorbers 10,
• the laundry drum 3 is in the tub 2 about a horizontal axis of rotation
• Laundry drum 3 be connected in a conventional manner.
• the tub 2 and the laundry drum 3 form a total of a vibrating system 16 which is suspended via the springs 7, 8 movable in the device housing 6.
• the shock absorbers 10, 1 1 are used for damping large amplitudes.
• a central control device 14 and an electronic engine control unit 15 are further arranged. While the central electronic control device 14 is used to control the care processes of the household appliance 1 and thus represents a higher-level control device, it is the task of the motor control unit 15 to control the electric drive motor 13. For example, while the speed of the drive motor 13 is controlled by means of the engine control unit 15.
• the central control device 14 can communicate with the engine control unit 15, for example via a communication bus, not shown, or wirelessly.
• the central control device 14 For controlling the care processes of the household appliance 1, the central control device 14 requires information about the current parameter values of various operating parameters of the household appliance 1, in particular information about the load weight or the dry mass of the laundry items 4.
• a displacement sensor 17 is used, which is located between the vibrating System 16 on the one hand and a bottom 18 of the device housing 6 is clamped and detects the movement of the tub 2 and the entire oscillating system 16 relative to the device housing 6 in the vertical direction z and thus perpendicular to the axis of rotation 12 or optionally in several dimensions.
• the Distance sensor 17 detects a current position or displacement of the oscillating system 16 with respect to a reference position, which corresponds in particular to a rest position of the oscillating system 16.
• the measured values provided by the displacement sensor 17 are transmitted to the control device 14, which then uses these measured values to determine the current load weight.
• Fig. 2 shows the dependence of one of the shock absorbers 10, 1 1 introduced into the vibrating system 16 force F of a lowering A of the oscillating system 16.
• the weight of the vibrating system 16 is inclusive of loading in an equilibrium with the forces of the springs 7, 8 and of the shock absorbers 10, 1 1 impressed force F.
• the linear course of the section 19 shows that the springs of the shock absorbers 10, 1 1 are continuously tensioned.
• a static friction FH of the shock absorber 10, 1 1 is overcome, and the friction lining slips through, which can be recognized by another portion 21, in which the force F decreases.
• section 22 the spring of the respective shock absorber 10, 1 stretched again, whereby after reaching the static friction FH, the friction lining slips again.
• the slippage takes place within a very small time interval T.
• T The interest here is the compensation of the determination of the load weight due to a change in the balance when the shock absorbers 10, 1 1 come into their non-linear working range and slip.
• the control device 14 evaluates the time profile of the measured values of the displacement sensor 17. The control device 14 checks whether a very large change in the measured values occurs within a very short time interval. If such a change is detected within a very short time, for example within two milliseconds, it can be assumed with very high probability that this change is due to a slipping shock absorber 10, 11.
• the measured value changes can basically be assigned to three possible causes:
• the rate of change v is nearly zero and thus less than a predetermined first limit G1: a low rate of change indicates a change in load weight and thus a conventional user loading action.
• the rate of change v is greater than the first threshold G1 and less than a higher second threshold G2.
• This moderate rate of change v indicates manual manipulation of the oscillating system 16 by the user, which is ignored by the controller 14 herein. This position change of the oscillating system 16 is thus not corrected in the determination of the load weight.
• the rate of change v is very large and therefore greater than the second limit G2: If this is detected, it is assumed that a slipping shock absorber 10, 1 1. Slippage of the shock absorber 10, 1 1, i. A displacement of the position of the friction lining within the shock absorber 10, 11, namely, is present when the measured values of the displacement sensor 17 change very rapidly, which can be detected by the control device 14 based on the rate of change v.
• FIG. 1 A typical dependence of the measured loading weight B on the actual load or the actual weight B 'of the introduced laundry items 4 is shown in FIG.
• the rate of change v is initially relatively low and almost equal to zero.
• the position or the displacement of the oscillating system 16 changes abruptly after reaching the static friction of the shock absorbers 10, 11.
• the controller 14 determines a change value 24 of the position of the oscillating system 16 caused by slippage.
• This change value 24 represents an offset, which is then compensated in the determination of the load weight B.
• the result of the determination of the loading weight B without this compensation is denoted by 25 in FIG.
• a Loading weight B determined by the control device 14 which is much more realistic.
• the loading weight B with the compensation according to the invention is designated 26 in FIG.
• the determined change value 24 is subtracted from the current measured values of the displacement sensor 17 detected after the detection of the slippage.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Control Of Washing Machine And Dryer (AREA)

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Citations (2)

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• 2014
  • 2014-03-06 DE DE102014204079.5A patent/DE102014204079A1/de not_active Withdrawn
• 2015
  • 2015-03-03 CN CN201580012290.4A patent/CN106062269B/zh active Active
  • 2015-03-03 WO PCT/EP2015/054444 patent/WO2015132270A1/de active Application Filing
  • 2015-03-03 EA EA201691662A patent/EA033635B1/ru not_active IP Right Cessation
  • 2015-03-03 ES ES15709138.0T patent/ES2690983T3/es active Active
  • 2015-03-03 EP EP15709138.0A patent/EP3114268B1/de active Active
  • 2015-03-03 PL PL15709138T patent/PL3114268T3/pl unknown

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