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
  • D06F2103/18—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
  • D06F2103/00—Parameters monitored or detected for the control of domestic laundry washing machines, washer-dryers or laundry dryers
  • D06F2103/44—Current or voltage
• • 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
  • D06F2105/02—Water supply

Definitions

• the present invention refers to a system to be applied to automatic laundry machines, which allows detecting a load of clothes put into the laundry machine and automatically selecting the level of the washing liquid to be supplied to the machine according to the washing program selected by the user.
• the invention further relates to a process for detecting a load of clothes put into the laundry machine and for automatically selecting the level of the washing liquid to be supplied to the machine, as a function of the detected load of clothes.
• An electronic control unit which is operatively associated with the height sensing means of the load of clothes, processes the signal coming from the height sensing means and which is representative of the height of the load of clothes, so as to determine the adequate level of the washing liquid to be admitted into the tub and to control the operation of a washing liquid inlet device, in order to maintain the latter opened, until a level sensing means detects the obtainment of the washing liquid level determined by the control unit .
• the height sensing means comprises means for transmitting and receiving sonic pulses that act on the load of clothes within the basket under rotation. While adequately operating, this prior art system requires complex expensive means and constructions.
• Patent US 6,460,381. a pressure sensor is provided, mounted jointly with the suspension of the tub and which is constructed so as to have its magnetic characteristics altered as a function of the stresses to which it is subjected. The variations of the magnetic characteristics are converted in inductance variations in a coil, generating oscillating signals whose frequency varies as a function of the inductance, allowing detecting the load on the sensor.
• the load of clothes placed in the basket can be determined, as well as the load of the washing liquid to be subsequently supplied to the tub of the machine, and the clothes-washing liquid total load is converted into a corresponding adequate level of the washing liquid.
• the supply of the washing liquid is automatically interrupted by actuation of an electronic control unit.
• This type of prior art system may present mechanical errors produced during manufacture or have the weight sensor located in an inadequate position, impairing the accuracy in detecting the weight of both the clothes and the washing liquid, resulting in washing operations presenting an amount of water out of the desirable standards.
• Still another known prior art system is described in Patent US 4,862,710.
• This prior system uses a load detecting means in the motor to detect an electrical value representative of a rise characteristic of the motor, which varies in accordance with a load acting on a motor which drives the movable washing means of the machine. During the spin cycle of the machine, the time in which the value detected by the load detector reaches a second reference value is measured, from a first reference value.
• the first and the second reference values are voltage values measured in the load detector, and the time the motor takes in the spin cycle, to provoke a rise in the voltage and reference values, is associated with a certain level of load of clothes within the basket .
• This prior art solution uses the voltage rise time between two reference values, which are corrected as a function of the supply voltage, to determine the load of clothes in the basket and the corresponding operational parameters of the machine in the subsequent operations .
• the system for detecting a load of clothes of the present invention is designed to be applied to an automatic laundry machine of the type which comprises a tub, a basket mounted in the interior of the tub and which is dimensioned to receive a load of clothes to be washed, and an electric motor, which rotatively drives the basket in a spin cycle to be executed by the machine .
• the present system comprises a voltage sensor to detect the value of the voltage supplied to the electric motor; a rotation sensor, operatively associated with the electric motor to detect the rotation of the latter; and a control unit, operatively associated with a timer, with the voltage sensor, and with the rotation sensor, and which is supplied, in a presetting step of the machine, with data representative of the medium torque of the electric motor in different voltage ranges, and with data representative of the acceleration and deceleration reference times of the electric motor with the basket in the unloaded condition, between two distinct and predetermined rotation values of the electric motor, in order to calculate the reference moment of inertia of the unloaded basket, said control unit receiving, selectively, at the beginning of each operation of the machine, data representative of the acceleration and deceleration operation times of the electric motor, with the basket containing a load of clothes, between said rotation values of the electric motor, and processing the data representative of the medium torque of the electric motor in the voltage range detected by the voltage sensor, and the data of the reference and operation times, in order
• the system mentioned above allows, through the provision of the voltage and rotation sensors and by providing the control unit with a timer, establishing reference data adjusted for each machine in the manufacturing phase, and operational data related to each load of clothes put into the basket, the processing of said data allowing comparing the respective moments of inertia and thence produce a signal which represents, with high accuracy, the load of clothes inserted in the basket and which will be washed, independently of the voltage variations of the power source of the electric motor.
• the signal representative of the load of clothes is associated with a washing liquid level which, when reached, makes the control unit produce a blocking signal to an inlet valve means, interrupting the supply of the washing liquid to the machine.
• the invention further relates to a process for detecting the load of clothes in an automatic laundry machine of the type defined above, comprising the following steps : - rotatively driving the electric motor with the basket unloaded, maintaining its energization until a maximum rotation has been reached, the electric motor being then de-energized and decelerated to a reduced rotation value, as a function of the friction between the movable parts;
• the process may further include an additional step of associating the signal representative of the mass of load of clothes with an adequate washing liquid level in the interior of the basket, in order to interrupt the supply of liquid to said machine after said level has been reached.
• the control unit Upon reaching the washing liquid level calculated as a function of the detected mass of the load of clothes, the control unit instructs an inlet valve means to interrupt the supply of the washing liquid.
• Figure 1 is block diagram of the system of the present invention associated with an automatic laundry machine
• Figure 2 is a graph with the curves showing the variation of rotation of the electric motor for obtaining the reference and operation times during acceleration and deceleration.
• an automatic laundry machine of the type which comprises a structural casing 1, generally defined by a prismatic cabinet, within which is mounted, through suspension means, not illustrated and which may present any adequate construction belonging or not to the state of the art; a tub 2, generally cylindrical and within which is coaxially rotatively mounted a basket 3, generally in the form of a cylindrical drum, having perforated lateral and bottom walls and which is superiorly open and dimensioned to contain a load of clothed to be washed.
• the basket 3 has its bottom wall 3a centrally affixed to a tubular shaft 4 projecting vertically downwardly and outwardly from the tub 2, so as to be supported by bearings 5 mounted on a bearing support 6 secured to the bottom wall 2a of the tub 2.
• This assembly allows the basket 3 to rotate freely around its axis, in the interior of the tub 2 and seated on the tubular axis 4.
• the lower end of the central shaft 8 projects outwardly from the tubular shaft 4 , in order to receive a driven pulley 13 which is operatively coupled, through a belt 12, to a drive pulley 11 secured to the shaft of an electric motor 10 mounted to the structural casing 1 of the machine, usually being directly or indirectly attached to the bottom wall 2a of the tub 2.
• the laundry machine generally further comprises a locking device to lock the tubular shaft 4 in relation to the structural casing 1 during the wash cycles to be performed by the machine, when only the agitator 9 is impelled by the electric motor 10 in opposite directions, to effect the movement of the load of clothes immersed in the washing liquid inside the basket 3.
• the automatic laundry machine might present different constructions, as long as it is provided with a basket provided in a tub and which is selectively rotatively driven by an electric motor.
• a control unit 20 for the electronic processing of data and which is operatively associated with a voltage sensor 30, a rotation sensor 40, a level meter 50, and an inlet valve means 60 to control the admission of the washing liquid, generally water, to the interior of the basket 3 .
• the voltage sensor 30 is usually defined by a voltmeter mounted in the machine to detect the value of the voltage supplied to the electric motor 10 an to send to the control unit 20 signals representative of the detected voltage values.
• the provision of the voltage sensor 30 allows the control unit 20 to consider the voltage value of the power source of the electric motor 10 in any processing operation to be performed thereby.
• the rotation sensor 40 takes the form of a tachometer that is operatively associated with the electric motor 10 to supply the control unit 20 with signals to be converted in data representative of the rotation of the electric motor 10.
• a level sensor 50 is provided, usually in the form of a pressure switch that sends, to the control unit 20, signals representative of different, generally three, levels of the washing liquid to fill the basket 3.
• the level meter 50 sends a respective signal to the control unit 20, which processes this signal and sends a signal to the inlet valve means 60, closing the latter and interrupting the supply of the washing liquid to the machine.
• the inlet valve means 60 can take the form of an electrovalve, for example, whose energization is commanded by the control unit 20.
• the control unit 20 is constructed to process the signals received from the different components operatively associated therewith, in order to produce a signal representative of the load of clothes inserted in the basket 3.
• the control unit 20 is supplied, in a presetting phase of the machine, with data representative of the medium torque of the electric motor 10 in different voltage values of the power source, generally in different voltage ranges of about 5V.
• control unit 20 is able to process the voltage signal received from the voltage sensor 30 and to determine the value of the medium torque of the electric motor 10 for the detected voltage of the power source.
• the basket 3 in the presetting phase of the machine, which generally occurs during manufacture, the basket 3 is rotatively driven upon the energization of the electric motor 10, from a rest condition, accelerating until reaching a predetermined rotation of the electric motor of about 1.300 rpm, the latter being de-energized so as to decelerate, jointly with the basket, to reduced rotation values, including the rest zero value.
• the control unit 20 detects, by means of the rotation sensor 40, the instants in which the rotation of the shaft of the electric motor 10 reaches two distinct and predetermined rotation values, both in the acceleration and in the deceleration phases of the basket 3.
• These distinct and predetermined rotation values of the electric motor 10 can be, for example of about 660rpm and 1120rpm, with a difference of about 460rpm between said values.
• the control unit 20 receives, through a timer 21 incorporated thereto, data representative of the acceleration reference time Tal and deceleration reference time Tdl of the electric motor 10 between said distinct and predetermined rotation values.
• the control unit 20 determines the medium torque Mmot of the electric motor for that voltage value and then calculates the moment of inertia Jv in the unloaded condition of the basket 3, establishing initially zero value for the resistive torque Mres (friction torque) of the rotary assembly, using the following equations:
• Mres Resistive torque (friction torque)
• the control unit 20 processes the already received data, in order to calculate a first value for the moment of inertia Jv of the basket 3 in the unloaded condition. With the initial value of the moment of inertia Jv in the unloaded condition, the control unit 20 calculates the resistive moment Mres by means of the formula (2) and subsequently utilizes said value to recalculate the moment of inertia Jv in the unloaded condition by the formula (1) , repeating this procedure until the difference between the Jv values reach a determined value close to or equal to zero.
• the control unit 20 records, by means of the voltage sensor 30, the voltage supplied to the electric motor 10, so as to select the respective value of the medium torque Mmot, and energizes the motor, in order to accelerate it jointly with the basket 3 already containing the load of clothes to be detected, until the predetermined maximum rotation has been reached, passing by said distinct and predetermined rotation values under acceleration and then, after the de-energization of the motor, under deceleration, allowing the control unit 20 to record the data representative of the acceleration and deceleration times Ta2 and Td2 during operation with the load of clothes. With the data representative of the medium torque Mmot and of the acceleration and deceleration times Ta2 and
• the control unit 20 calculates the moment of inertia Jc of the basket 3 containing the load of clothes to be detected, by using the same procedure described in relation to the determination of the moment of inertia Jv of the empty, i.e. unloaded, basket 3.
• the control unit 20 begins to calculate the load of clothes by the difference between the moments of inertia Jc in the loaded condition and the moment of inertia Jv in the unloaded condition, producing a respective signal to be used in a subsequent operation of the machine to be performed with at least one parameter depending on the value of the load of clothes placed in the basket 3.
• the control unit 20 associates the data representative of the load of clothes with a determined level of the washing liquid inside the basket 3.
• control unit 20 When this level, which is determined as adequate by the control unit 20, is detected by the level meter 50, the control unit 20 instructs the closing of the inlet valve means 60, interrupting the supply of the washing liquid to the machine .
• the subsequent operations may vary as a function of the operation programs associated with the control unit and which are generally selected by the user.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Control Of Washing Machine And Dryer (AREA)
• Force Measurement Appropriate To Specific Purposes (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=36642304

Family Applications (1)

Country Status (10)

Cited By (5)

Families Citing this family (18)

Citations (4)

Family Cites Families (8)

• 2003
  • 2003-03-13 BR BR0300737-5A patent/BR0300737A/pt not_active IP Right Cessation
• 2004
  • 2004-03-11 AR ARP040100780A patent/AR043546A1/es not_active Application Discontinuation
  • 2004-03-12 JP JP2006504052A patent/JP2006519641A/ja not_active Withdrawn
  • 2004-03-12 US US10/549,404 patent/US20070193310A1/en not_active Abandoned
  • 2004-03-12 KR KR1020057017141A patent/KR20050110670A/ko not_active Application Discontinuation
  • 2004-03-12 CL CL200400511A patent/CL2004000511A1/es unknown
  • 2004-03-12 CN CNA2004800103816A patent/CN1795300A/zh active Pending
  • 2004-03-12 MX MXPA05009784A patent/MXPA05009784A/es unknown
  • 2004-03-12 CA CA002519067A patent/CA2519067A1/en not_active Abandoned
  • 2004-03-12 WO PCT/BR2004/000029 patent/WO2004081276A1/en active Application Filing

Patent Citations (4)

Also Published As

Similar Documents

Legal Events