EP0879913A1 - Method for ensuring a correct dynamic trim of the washing assembly of washing machines and washing machine implementing said method - Google Patents

Method for ensuring a correct dynamic trim of the washing assembly of washing machines and washing machine implementing said method Download PDF

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Publication number
EP0879913A1
EP0879913A1 EP98106693A EP98106693A EP0879913A1 EP 0879913 A1 EP0879913 A1 EP 0879913A1 EP 98106693 A EP98106693 A EP 98106693A EP 98106693 A EP98106693 A EP 98106693A EP 0879913 A1 EP0879913 A1 EP 0879913A1
Authority
EP
European Patent Office
Prior art keywords
washing
washing machine
assembly
stationary structure
phase
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP98106693A
Other languages
German (de)
English (en)
French (fr)
Inventor
Mario Tabasso
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Electrolux Zanussi Elettrodomestici SpA
Electrolux Zanussi SpA
Original Assignee
Electrolux Zanussi Elettrodomestici SpA
Electrolux Zanussi SpA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Electrolux Zanussi Elettrodomestici SpA, Electrolux Zanussi SpA filed Critical Electrolux Zanussi Elettrodomestici SpA
Publication of EP0879913A1 publication Critical patent/EP0879913A1/en
Withdrawn legal-status Critical Current

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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 
    • D06F33/50—Control of washer-dryers characterised by the purpose or target of the control
    • D06F33/76—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
    • D06F2103/26—Imbalance; Noise level

Definitions

  • the present invention generally refers to washing machines, in particular, although not limited to, residential-type clothes washing and combined clothes washing and drying machines, that are provided with a washing assembly including a rotating drum mounted inside an outer stationary structure.
  • washing machines usually those with a substantially horizontal-axis drum, which have at least a washing speed and a markedly higher spin-extraction speed which may reach up to 1800 to 2000 rpm.
  • These machines generally pose a quite demanding challenge to their manufacturers in view of being ensured a correct dynamic trim of their washing assembly, so as to enable the machines to operate without vibrations and with a very low noise levels.
  • tachometric or accelerometric (usually iterative) methods have been incorporated in washing machines to control the displacements of the washing assembly with respect to the outer stationary structure.
  • Such methods comprise a first phase in which signals are detected that are correlated to the rotational speed (rpm) of the electric motor driving the drum, said signals being indicative of the above cited displacements, as well as a second phase in which operation parameters of the machine are modified accordingly, in order to eliminate the causes of unbalance of the rating drum or, at least, to minimize the effects thereof.
  • Control methods of this kind which operate mainly during the acceleration of the rotating drum from the washing speed to the spin-extraction one, are undeniably effective, although they are based on an indirect detection of the displacements of the washing assembly.
  • the devices needed to implement said methods may considerably affect the overall manufacturing costs of a washing machine, since they require the use of quite sophisticated component parts such as accelelometers, tachometers or speedometers and universal electric motors, with the therewith associated microprocessor and related means.
  • the method is also known consisting in connecting a normally closed microswitch in series with a tachometer which is in turn connected with the electronic drum motor driving module that controls the speed, ie. the rpm, thereof.
  • Said microswitch is arranged to detect an unbalance condition of the drum and, when such an unbalance rises over a pre-determined threshold, it cuts off the connection between the tachometer and the module controlling the motor that drives the rotating drum.
  • this solution fails to make the washing machine less expensive to any significant extent, since it anyway keeps requiring the use of such sophisticated component parts as the tachometer.
  • it is tied up to the use of such a device as a microswitch, the operation of which is of the "on-off" type.
  • a method for ensuring a correct dynamic trim of the washing assembly comprises the phases shown in Figure 1.
  • the block 1 in Figure 1 represents the operating state (ON) of the clothes washing machine or, more precisely, the phase of the programmed cycle during which the drum 11, which is driven by an electric motor (not shown in Figure 2 for greater simplicity), is for instance at the beginning of an acceleration from a washing speed of 60 rpm up to a spin-extraction speed of 1500 rpm.
  • the drum 11 and the non-perforated tub 12 enclosing it are part of a so-called washing assembly, which is generally shown at 13. It has a front opening 19 surrounded by a bellows-type gasket for loading the washload items into the drum 11.
  • the washing assembly 13 is connected to the outer stationary structure 14, which is in the shape of an outer casing or cabinet, through suspension springs 15 and friction-type shock-absorber struts 16 that are mounted between the tub 12 and the base 17 of the machine.
  • the distance from the washing assembly 13 and the outer casing 14 in fact varies, with respect to the condition in which the machine is at a standstill with no washload in its drum, owing to the effects of the washload, which is constituted by both the clothes items to be washed and the wash liquor itself.
  • the washing assembly 13 When, during the phase of acceleration from the washing speed to the spin-extraction speed, the washload items happen to be evenly distributed all along the periphery of the rotating drum 11, the washing assembly 13 is balanced, ie. it has a correct dynamic trim. Even at the highest possible spin-extraction speeds , said distance from the washing assembly 13 to the outer casing 14 will in fact remain substantially unaltered, ie. will not decrease to such values as to be likely to cause other parts of the washing machine to suffer damages due to the oscillations of the washing assembly 13, which is usually provided with appropriate counterweights (not shown in Figure 2), with respect to the outer casing 14.
  • the washing assembly 13 becomes unbalanced and is therefore subject to oscillations or fluctuating displacements S, with respect to the trim it assumes when in a balanced condition (block 2 in Figure 1).
  • the present invention ensures a correct dynamic trim of the washing assembly 13 which therefore prevents, even under these circumstances, the other parts of the machine from being damaged.
  • the method according to the present invention provides for converting, as this is represented by the block 3 in Figure 1, the afore mentioned fluctuating displacements S of the washing assembly 13 into variations ⁇ p in the pressure of the medium contained in a transducer 20, which will be described in greater detail further on, as well as making use of such pressure variations in a therewith associated manometric device 27.
  • the instantaneous value ⁇ p I of such a function is constantly monitored and detected (block 4 in Figure 1) throughout the operating cycle of the washing machine or, at least, during the acceleration of the drum 11 from washing speed to spin-extraction speed.
  • said instantaneous value ⁇ p I is compared with a limit value ⁇ M (block 5 in Figure 1) which is either pre-set at the design stage of the washing machine or, possibly, pre-selected by the same user of the washing machine among a plurality of available options, for instance according to the type of clothes to be washed.
  • the method according to the present invention provides for an instantaneous modification of operation parameters of the washing machine to take place along the line N, as this is represented by the block 7.
  • Another operation parameter of the washing machine that can be modified, in the presence of a "yes" output in the block 5 of Figure 1 and when the friction-type shock-absorber struts 16 contain a magnetorheological medium, consists of an increase in the vabration damping power of the friction-type shock-absorber struts through a variation in the voltage and/or current that generates the magnetic field in said magnetorheological medium. This does not enable the cause of the unbalance condition of the rotating drum 11 to be eliminated, actually, but the effect thereof is correspondingly reduced since the extent of the fluctuating displacements S is forcedly limited.
  • the method of the present invention can most advantageously be integrated with the method described in the pending Italian patent application no. PN97A000029 filed on May 15, 1997 by the same Applicant.
  • transducer means adapted to convert into pressure variations ⁇ p the afore mentioned fluctuating displacements S of the washing assembly 13 of the machine, and a therewith associated manometric device.
  • An embodiment of said means is illustrated, albeit schematically, in Figure 3.
  • the transducer means 20 substantially consists of a hollow body with a roughly cylindrical configuration, formed by mutually opposing first and second portions 21 and 22 that are made of a rigid material. eg. metal, and are in the shape of a cup, as well as a third portion 23 for connecting said first and second portions 21 and 22 to each other, which is made of an elastically deformable material, eg. rubber, and has a bellows-like shape.
  • the above cited end portions 21 and 22 are provided with an elongated appendix 24 and 25, respectively, that enables them to be rigidly attached to the tub 12 and a side wall 18 of the outer casing 14 of the washing machine, respectively.
  • Such an attachment of the tansducer 20 can for instance be carried out by means of nuts (not shown) if said appendices 24 and 25 are threaded and appropriate eyelet-like seats (not shown, either) are provided on the tub 13 and the inner face of the side wall 18. Since air is most suitably used as a working fluid, in the same second portion 22 of the transducer 20 there is provided a compensating hole 28.
  • the diplacements S (represented by an arrow in Figure 3) of the washing assembly 13, and therefore of the first end portion 21 of the transducer 20, with respect to the outer casing 14, and therefore of the second end portion 22, are converted in the transducer 20 into pressure variations ⁇ p of the therein contained medium owing to the elastic deformations of the bellows-like portion 23.
  • the pressure switch 27 which is rated and adjusted in accordance with the pre-deterinined limit value ⁇ M , the instantaneous values ⁇ p I of the pressure variations are therefore detected, compared and used, according to the afore described principle and method, to accordingly modify, when the circumstances are such as to require this, operation parameters of the washing machine.

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Control Of Washing Machine And Dryer (AREA)
EP98106693A 1997-05-21 1998-04-11 Method for ensuring a correct dynamic trim of the washing assembly of washing machines and washing machine implementing said method Withdrawn EP0879913A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT97PN000030A IT1294131B1 (it) 1997-05-21 1997-05-21 Metodo per assicurare un corretto assetto dinamico del gruppo lavante di una macchina lavatrice e macchina per l'attuazione
ITPN970030 1997-05-21

Publications (1)

Publication Number Publication Date
EP0879913A1 true EP0879913A1 (en) 1998-11-25

Family

ID=11395261

Family Applications (1)

Application Number Title Priority Date Filing Date
EP98106693A Withdrawn EP0879913A1 (en) 1997-05-21 1998-04-11 Method for ensuring a correct dynamic trim of the washing assembly of washing machines and washing machine implementing said method

Country Status (3)

Country Link
EP (1) EP0879913A1 (nl)
JP (1) JPH10328479A (nl)
IT (1) IT1294131B1 (nl)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0967318A1 (de) 1998-06-27 1999-12-29 Miele & Cie. GmbH & Co. Waschmaschine mit einem Niveausensor und mit einem System zur Messung von unwuchtbedingten Auslenkungen des Laugenbehälters
US6418581B1 (en) 1999-06-24 2002-07-16 Ipso-Usa, Inc. Control system for measuring load imbalance and optimizing spin speed in a laundry washing machine

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101286819B1 (ko) * 2010-03-24 2013-07-22 가부시끼가이샤 도시바 세탁기
JP5597439B2 (ja) * 2010-05-06 2014-10-01 株式会社東芝 ドラム式洗濯機
EP2568070A4 (en) * 2010-05-06 2018-01-10 Toshiba Lifestyle Products & Services Corporation Washing machine
JP5489104B2 (ja) * 2010-05-21 2014-05-14 株式会社東芝 ドラム式洗濯機
JP2017113310A (ja) * 2015-12-24 2017-06-29 青島海爾洗衣机有限公司ＱｉｎｇＤａｏ Ｈａｉｅｒ Ｗａｓｈｉｎｇ Ｍａｃｈｉｎｅ Ｃｏ．，Ｌｔｄ． 洗濯機

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2079791A (en) * 1980-07-19 1982-01-27 Licentia Gmbh Washing machine
US5277281A (en) * 1992-06-18 1994-01-11 Lord Corporation Magnetorheological fluid dampers
US5375282A (en) * 1993-09-20 1994-12-27 General Electric Company System and method for detecting and interrupting an out-of-balance condition in a washing machine
EP0750065A1 (de) * 1995-06-23 1996-12-27 Miele & Cie. GmbH & Co. Vorrichtung und Verfahren zur Bestimmung der Unwucht bei einer Trommelwaschmaschine
DE19616635A1 (de) * 1996-04-26 1997-10-30 Aeg Hausgeraete Gmbh Verfahren zur Unwuchterfassung einer Waschmaschine

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2079791A (en) * 1980-07-19 1982-01-27 Licentia Gmbh Washing machine
US5277281A (en) * 1992-06-18 1994-01-11 Lord Corporation Magnetorheological fluid dampers
US5375282A (en) * 1993-09-20 1994-12-27 General Electric Company System and method for detecting and interrupting an out-of-balance condition in a washing machine
EP0750065A1 (de) * 1995-06-23 1996-12-27 Miele & Cie. GmbH & Co. Vorrichtung und Verfahren zur Bestimmung der Unwucht bei einer Trommelwaschmaschine
DE19616635A1 (de) * 1996-04-26 1997-10-30 Aeg Hausgeraete Gmbh Verfahren zur Unwuchterfassung einer Waschmaschine

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0967318A1 (de) 1998-06-27 1999-12-29 Miele & Cie. GmbH & Co. Waschmaschine mit einem Niveausensor und mit einem System zur Messung von unwuchtbedingten Auslenkungen des Laugenbehälters
US6418581B1 (en) 1999-06-24 2002-07-16 Ipso-Usa, Inc. Control system for measuring load imbalance and optimizing spin speed in a laundry washing machine
US6564592B2 (en) 1999-06-24 2003-05-20 Ispo-Usa, Inc. Control system for measuring load imbalance and optimizing spin speed in a laundry washing machine

Also Published As

Publication number Publication date
JPH10328479A (ja) 1998-12-15
ITPN970030A1 (it) 1998-11-21
IT1294131B1 (it) 1999-03-22
ITPN970030A0 (nl) 1997-05-21

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