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
  • D06F34/16—Imbalance
• • 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 
  • D06F33/48—Preventing or reducing imbalance or noise
• • 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
  • D06F2103/24—Spin speed; Drum movements
• • 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
  • D06F2103/00—Parameters monitored or detected for the control of domestic laundry washing machines, washer-dryers or laundry dryers
  • D06F2103/44—Current or voltage
  • D06F2103/46—Current or voltage of the motor driving the drum
• • 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
  • D06F2105/52—Changing sequence of operational steps; Carrying out additional operational steps; Modifying operational steps, e.g. by extending duration of steps
• • 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
  • D06F33/40—Control of operational steps, e.g. optimisation or improvement of operational steps depending on the condition of the laundry of centrifugal separation of water from the laundry

Definitions

• the present invention relates to a method for determining unbalanced load, which provides an efficient operation of the washing machine by determining the unbalanced load created by the uneven distribution of the laundry being washed in the tub, during the spinning cycle.
• the rotational axis and the center of gravity do not match with each other when the clothes in the drum which are stuck to the inner walls of said drum by the centrifugal force, are not distributed stably.
• the dangerous centrifugal forces that occur in this case may cause an overstrain of the washing machine strength, formation of harmful vibrations and even the moving of the washing machine itself.
• the unbalanced load occurred due to the distribution of the laundry in the rotating drum during the spinning cycle is determined according to the unloaded drum reference.
• the unbalanced load accumulated at a certain area in the drum looses its potential energy due to the gravitational force, during the downward movement of the drum and produces a moment, which is directly proportional with the distance of the unbalanced load from the center of rotation.
• the unbalanced load is raised upwards, it gains potential energy and the motor generates additional moment that is proportional with the distance between the unbalanced load and the center of rotation, in addition to the torque required to drive a balanced system.
• the measurement can be made at low rpm drum speed values such as 100 rpm at which drum speed, the sticking of the laundries to the inner peripheral wall of the drum is ensured; and the principle of calculating the variation of speed oscillations in direct proportion with the amount of unbalanced load, is evaluated by waiting for a certain time and inputting an error band, and then estimating the amount of the unbalanced load. As each unbalanced load creates a different standard deviation, this serves for determining whether spinning cycle will be started or at which maximum speed the spinning can be performed.
• load is estimated by raising the laundry to a certain angle and by reading the maximum current drawn at that moment in a direct drive structure in a direct drive structure or by applying voltage until a certain current is attained, then observing the angle reached at that current.
• total load and unbalanced load are determined by signals obtained from the motor.
• German Patent Application No. 4336349 the inertia of the amount of wet laundry is determined by means of a spinning procedure.
• the object of the present invention is to develop a method for determining an unbalanced load depending on the amount of laundry loaded in washing machines, which ensure a safe operation of the washing machine particularly during the spinning cycle.
• Figure la is the flow chart of the method for determining unbalanced load
• Figure lb is the flow chart of an embodiment of the method for determining unbalanced load
• Figure 2 is a graphic showing the number of cycles and steps in the method for determining unbalanced load.
• the domestic appliances preferably washing machines of a front loading type
• a drum in which the clothes to be washed defined as "the load” are placed and which performs the washing and spinning procedures by rotating about an axis
• an electronic control card that provides control.
• Said control card comprises at least one micro controller and at least one internal/external data storage unit.
• the data storage unit may be an external unit on said control card or may be an internal unit within the micro controller, such as RAM; ROM; EEPROM. In the preferred embodiment, data is recorded on a ROM included in the micro controller.
• TK double pole noof the tachogenerator
• TK tachogenerator double poles
• KKO belt-pulley spin rates
• the PI controller arranges data with determined periods or frequencies for calculating the firing angle and dutycycle and then the motor is driven. In this manner, the motor rotates at desired cycles and the data obtained from the motor can be interpreted in a time-dependent manner in order to be used.
• the microcontroller is also provided with a memory containing the experimental data determined in the production or design stages entered by the manufacturer, so that the data received can be compared and interpreted.
• the unbalanced load determining method detects the unbalanced load in relation with the balanced load present in the washing machine. Said method, by determining correctly the balanced and unbalanced loads during spinning, enables the spinning cycle to be performed at spinning rates wherein the centrifugal forces and vibrational amplitudes to be created by the balanced and unbalanced loads are within acceptable ranges, and/or provides a more efficient spinning performance.
• the unbalanced load determining system comprises the steps of; water discharge (100), distribution (200), pre-spinning (300) and spinning (400). Said method brings the unbalanced state of the load in the machine to a balanced state, in the distribution step (200), then starts the spinning operation, determines the unbalanced load by checking the speed variations and motor potential profiles obtained during the pre-spinning step (300) and provides a safe spinning during the spinning step (400) according to the unbalanced load values obtained. In order to calculate the number of distributing cycles (m) and the number of pre spinning cycles (n) to be performed after the washing cycle, the initial values of the number of distributing cycles (m) and the number of prespinning cycles (n) are defined as "0" by the control card. In the unbalanced load determining method that is started after identifications, water in the drum of the washing machine is drained before each spinning, until it falls below a certain level (100) (A).
• a spinning test speed that is much lower than the resonance spinning speed but able to provide the sticking of the laundry to the peripheral walls of the drum is attained (204) from the washing speed with a low acceleration, in a long time range; and a distribution step (200) is performed at this test speed that is kept constant for a certain time range (205), during which step, the change in the speed values measured sequentially is compared to the data obtained in the experiments made during design and production stages, in order to make the first decision about the amount of the unbalanced load.
• the discharge pump operates continuously and evacuates water when required.
• the drum When the test speed (205) is reached, the drum is given a short time to run in the test speed and it is checked if an absolute deviation from the test speed has entered a certain range.
• speed measurements are taken along the "k" number of revolutions in order to obtain sufficient statistical data and the desired unbalanced load differentiation.
• the required measurement number is obtained by using the function N (k) formed by the coefficient of the tachogenerator value and the belt-pulley revolution rate.
• Absolute value deviations of the speed values measured (hi) from the test speed (h tes t) are calculated ( I hi - h tes t I ).
• the deviation (h ⁇ j e viation) (equation 2) from the test speed during the spinning cycle (205) is calculated.
• the value of deviation from the test speed obtained (h dev ( 20 5) ) is compared to the values obtained in the reference measurement found during the production stage and recorded to the microprocessor, and the unbalanced load values in the unloaded drum are found. These values correspond to the smallest amount of unbalanced load with respect to other balanced load positions. In case this value is not sufficient to allow topass to the rinsing cycle, the drum is stopped before passing to the algorithm of determining balanced load, and the distribution step (A) is restarted after increasing the number (m) of distribution revolutions by one more revolution. If the level is still above the limit determined by the manufacturer, said distribution step (200) is repeated "m max " times as defined by the manufacturer. In case of a failure, the procedure is terminated. If such a restriction is not seen, pre-spinning step (300) starts after the distribution step (200), (B).
• a prespinning speed rate which is almost 2 fold the resonance spinning speed, is attained in a short time, with a high acceleration rate (301).
• This high acceleration which is also referred to as the ramp, serves to avoid the moment of the washing machine or the crashing of the components in the machine by passing the resonance frequencies rapidly.
• Spinning is performed for a certain period at the prespinning speed (t set ti ⁇ ng (302)) (302). This period (t set tiing ( 302) ) ensures both the running of the drum in the prespinning speed, and that water has been evacuated in such an amount that an excessive impact between the tank and the drum is avoided.
• the proportion between the rms voltage (Vrms) and the rms input voltage (Vrms.jnput), corresponds to a certain firing angle ( ⁇ ) used for adjusting the motor voltage AC -motor phase angle controlled drive systems or to the duty cycle ( ⁇ ) in systems with DC chopper (Equation 3).
• V rms (V rms i npUt ) x ((( ⁇ - )/2+sin(2 ⁇ )/4)/ ⁇ ) (equation 3.2)
• the average (h deviatio n ( 3 0 4 )) and ((h deviatio n (2o 5 )) test speed measurement values is used instead of using only the test speed measurement value (h deviation(304))-
• the load (Y) value is determined after the equation 6.1 or 6.2 is solved by means of the constant values (SI, S2, S3, S4 .%) to which the data received are entered end which is recorded in the data storage unit after being found by the experimental data.
• the load value (Y) and other data collected, are placed in the equation 7.1 or 7.2 and solved by means of the constant values (SI, S2, S3, S4 .7) to which the data received are entered and which are obtained by the experimental data and recorded in the data storage unit, and thus the unbalanced load value (DY) is obtained.
• the unbalanced load (DY) value is found by using the equation 6.1 and 7.1 in systems with DC chopper, and by using the equation 6.2 and 7.2 in systems with AC phase control.
• the microcontroller determines the spinning profiles, including such parameters as the speed, time etc. to define the speed rates and durations of the spinning according to the state of the unbalanced load (C).
• Options for spinning profiles comprises the spinning stages (400) such as:
• a test speed rate of 100 rpm and a prespinning speed rate of 400 m are applied for a domestic appliance having a resonance frequency of approximately 200 rpms (Fig. 2).
• the balanced and unbalanced loads at the beginning of spinning will be determined accurately and suitable distribution or spinning algorithms can be employed. It will be possible to develop washing machines with higher load capacities at smaller volumes. As reliable and efficient spinning profiles are provided, such problems that may arise due to spinning, as opening of the drum, bearing fractures, wearing of the damper, etc. are avoided and the service load can be decreased. Furthermore, by virtue of the reliable and efficient spinning profiles provided by the method according to the invention, a reduction in uses for testing pu ⁇ oses under design or production conditions as well as strength is provided.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Control Of Washing Machine And Dryer (AREA)
• Mechanical Treatment Of Semiconductor (AREA)
• Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
• Sorption Type Refrigeration Machines (AREA)
• Testing Of Balance (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=21623533

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (8)

Family Cites Families (6)

• 2002
  • 2002-11-29 TR TR2004/01250T patent/TR200401250T1/xx unknown
  • 2002-11-29 WO PCT/TR2002/000068 patent/WO2003046271A1/en not_active Application Discontinuation
  • 2002-11-29 AT AT02795472T patent/ATE391803T1/de not_active IP Right Cessation
  • 2002-11-29 EP EP02795472A patent/EP1461487B1/de not_active Expired - Lifetime
  • 2002-11-29 DE DE60226075T patent/DE60226075T2/de not_active Expired - Lifetime
  • 2002-11-29 AU AU2002360235A patent/AU2002360235A1/en not_active Abandoned

Non-Patent Citations (1)

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