GB2280519A - Clothes washing machine with motor speed control - Google Patents

Clothes washing machine with motor speed control Download PDF

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Publication number
GB2280519A
GB2280519A GB9415821A GB9415821A GB2280519A GB 2280519 A GB2280519 A GB 2280519A GB 9415821 A GB9415821 A GB 9415821A GB 9415821 A GB9415821 A GB 9415821A GB 2280519 A GB2280519 A GB 2280519A
Authority
GB
United Kingdom
Prior art keywords
motor
rotational speed
command
voltage
voltage value
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.)
Granted
Application number
GB9415821A
Other versions
GB9415821D0 (en
GB2280519B (en
Inventor
Masahiro Imai
Yosiyuki Makino
Hiroshi Ikeda
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.)
Toshiba Corp
Toshiba AVE Co Ltd
Original Assignee
Toshiba Corp
Toshiba Audio Video Engineering Co Ltd
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
Priority claimed from JP2226917A external-priority patent/JP2786729B2/en
Application filed by Toshiba Corp, Toshiba Audio Video Engineering Co Ltd filed Critical Toshiba Corp
Publication of GB9415821D0 publication Critical patent/GB9415821D0/en
Publication of GB2280519A publication Critical patent/GB2280519A/en
Application granted granted Critical
Publication of GB2280519B publication Critical patent/GB2280519B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

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
    • D06F37/00—Details specific to washing machines covered by groups D06F21/00 - D06F25/00
    • D06F37/30—Driving arrangements 
    • D06F37/304—Arrangements or adaptations of electric motors
    • 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
    • D06F34/08—Control circuits or arrangements thereof
    • 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
    • D06F2105/46—Drum speed; Actuation of motors, e.g. starting or interrupting
    • D06F2105/48—Drum speed
    • 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
    • D06F34/10—Power supply arrangements, e.g. stand-by circuits
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B40/00—Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers

Landscapes

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

Abstract

A clothes washing machine includes an agitator driven by a dc brush less motor 3 and a microcomputer-based control device 21. The rotational speed of the motor 3 is detected 13 and compared with a target speed. Voltage command means supply motor drive control means with a value of voltage to be applied to the motor based on the target speed. Voltage value command changing means compare the detected speed of the motor with the target speed and change the voltage value command in accordance with the difference between the speed of the motor and the target speed, preferably in a stepwise manner. <IMAGE>

Description

CLOTHES WASHING MACHINE This invention relates to a clothes washing machine wherein a drive motor for driving an agitator and a rotational tub is driven at a target number of revolution.
An agitator is provided in a rotational tub serving both as a washing tub and a dehydrating tub, for example, in full automatic clothes washing machines. The agitator is rotated alternately forward and backward by a drive motor in a washing step while the rotational tub and the agitator are rotated by the drive motor in a dehydration step. It has recently been proposed that a brushless motor be employed as the drive motor in the above-described type clothes washing machine and that the brushless motor be driven at a target rotational speed by an inverter drive circuit. More specifically, a microcomputer-based control device is provided for controlling various loads of the clothes washing machine based on inputs from switches in accordance with a previously stored operation program. The control device comprises a rotational speed command section for commanding a target rotation speed to drive the motor at it and a voltage command section for supplying the inverter drive circuit with the voltage applied to the motor based on the command from the revolution command section. A revolution detecting section is also provided for detecting rotational speed Of the motor so that a feedback control is performed based on the detected rotational speed of the motor.
The drive motor needs to be deenergized immediately when locked for the reason, for example, that clothese are caught in between the agitator and the rotational tub during the washing operation. Further, the user needs to be warned against such an abnormal condition.
In this case it is generally considered that whether or not rotational speed of the motor can reach a predetermined value can be determined for the purpose of detecting such a locked motor condition. However, an amount of load applied to the motor is varied because of the position of the clothes in the rotational tub or the like, resulting in unevenness in the rotational speed.
Consequently, it is difficult to detect the locked motor condition with reliability or to determine whether the locked motor condition is temporary and safe or continuous and dangerous.
Further, in the feedback control of the motor speed, the rotational speed detected by the motor speed detecting section is compared with the target rotational speed at that time. The voltage applied to the motor is increased by a predetermined value when the detected rotational speed is smaller than the target rotationals peed while the applied voltage is decreased by a-predetermined value when the detected rotational speed in the rotational tub as described above or when the clothes are put into or taken out of the rotational tub during the washing operation. In such a case the conventional feedback control requires much time for the motor to reach the target rotational speed.
An object of the invention is to provide a clothes washing machine which is provided with a drive motor driven at a target rotational speed and wherein the rotational speed of the drive motor can be promptly controlled so as to reach the target rotational speed.
According to the present invention, there is provided a washing machine comprising: a) an agitator driven for agitating clothes to be washed; b) a motor for driving the agitator; c) motor drive control means for controlling a voltage applied to the motor in accordance with a voltage value command; d) rotational speed detecting means for detecting the rotational speed of the motor; e) rotational speed command means for producing a command of a target rotational speed for the motor; f) voltage command means for supplying the motor drive control means with a value of voltage applied to the motor based on the command of the target rotational speed produced by the voltage command means; and g) voltage value command changing means comparing the rotational speed of the motor detected by the rotational speed detecting means with the target rotational speed produced by the rotational speed command means, the voltage value command changing means changing the voltage value command produced by the voltage command means in accordance with the difference between the rotational speed of the motor and the target rotational speed.
Preferably, the voltage value command changing means changes the voltage value command stepwise in accordance with the difference between the detected rotational speed of the motor and the target rotational speed.
The invention will be described, merely by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a flowchart for explaining a voltage value command changing manner in the washing machine according to the invention; and Fig. 2 is a block diagram showing an overall electrical arrangement of the washing machine.
An electrical'arrangement of the washing machine is schematically shown in Fig. 2. The washing machine comprises a rotational tub (not shown) mounted within an outer cabinet (not shown) for both of the washing and dehydration. Clothes to be washed is contained in the rotational -tub (not shown). The washing machine is provided with a water supply value 1 for supplying water to the rotational tub and a drain valve 2 for discharging the wash liquid. An agitator (not shown) is mounted in the rotational tub for causing water streams for the washing. The agitator is rotated forward and backward alternately by the drive motor 3 repeatedly in a wash step. The rotational tub and the agitator are simultaneously rotated by the drive motor 3 in a dehydration step. Various switches 4 and a display section 5 for displaying the washing period of time, the washing course and the like are provided in the top of the outer cabinet. These switches 4 include selection switches for the user to select a desired washing course and a start switch.
Referring to Fig. 2, the drive motor 3 rotating the agitator and the rotational tub is driven under control of the motor drive control circuit 8 as the motor drive control means so that the voltage applied to the motor 3 can be varied in accordance with the voltage value command. The motor drive control circuit 8 comprises the drive circuit 11 to which a dc output is supplied via the dc power supply circuit from the ac power source 9 and the control circuit 12 which performs switching of the drive circuit 11 to execute timing of the energization of the motor 3 and the PWM control. The motor 3 is provided with the position sensor 13 for sensing the rotational position of the motor 3. The timing of energization of the motor drive control circuit 8 is specified based on the position signal from the position sensor 13. The position signal from the position sensor 13 is supplied to the control device 21 and the position sensor 13 constitutes a part of the rotational speed detecting means for detecting the rotational speed of the motor 3.
A microcomputer-based control device 21 is supplied with signals from the switches 4, the water level sensor 7 and the like. Based on these input signals, the control device 21 controls the water supply valve 1, the drain valve 2, the display section 5 and the like in accordance with the operation program previously stored in it. The control device 21 further controls the drive motor 3 via the motor drive control circuit 8 as motor drive control means so that the steps of the washing operation are performed. The control device 21 also delivers to the control circuit 12 the command of voltage value applied to the motor 3, operation start and stop signals and forward and backward rotation signals for the drive motor 3.
A power feed circuit for the drive motor 3 will be described. A dc power supply circuit 10 comprising a diode bridge and a smoothing capacitor is connected to an ac power source 9. The dc output of the dc power supply circuit 10 is supplied to a drive circuit 11 forming a part of the motor drive control circuit 8.
The control device 21 operates to control various mechanisms in accordance with the previously stored program so that the washing operation is performed, as described above. In addition, the control device 21 is arranged in the software arrangement to serve as rotational speed command means, voltage value command means and voltage value command changing means as well as the above-described rotational speed detecting means.
The rotational speed command means is arranged to output a command for the target rotational speed of the drive motor 3. The target rotational speed differs depending upon a selected washing course. Based on the command of the target rotational speed from the rotational speed command means, the voltage command means operates to determine the value of'voltage applied to the drive motor 3 and output the determined voltage value to the control circuit 12.of the motor drive control circuit 8.
The voltage value command changing means compares the rotational speed of the motor 3 detected by the revolution detecting means with the target rotational speed output from the rotational speed command means and changes the voltage value command from the voltage value command means in accordance with the difference between them. When the difference between the detected rotational speed and the target rotational speed is relatively large, for example 10 r. p. m. or more, the voltage applied to the motor 3 is increased or redcued by an amount larger than in the case where the difference is below 10 r. p. m.
In the embodiment, the voltage value command is output from the control device 21 in the manner shown in Fig. 1. More specifically, when the drive motor 3 is driven, the voltage value command is supplied to the motor drive control circuit 8 from the voltage value command means based on the target rotational speed output from the rotational speed command means (step S32), thereby driving the motor 3. Then, the rotational speed of the motor 3 is detected by the rotational speed detecting means (step S33). The detected rotational speed is compared with the target. rotational speed at step S34. When there is no difference between the detected rotational speed and the target rotational speed, the voltage value command is maintained at the value at that time since the motor 3 is being driven at the target rotational speed. On the other hand, when there is some difference between the detected rotational speed and the target rotational speed, it is determined whether the difference is small or large (step S35).
When the difference is small or below 10 r.p.m., the output of the voltage value command is increased or decreased by 1 bit, for example, at step S36. In this case when the detected rotational speed is smaller than the target rotational speed, the voltage applied to the motor 3 is increased while it is decreased when the detected rotational speed is larger than the target rotationl speed.
When the difference between the detected rotational speed and the target rotational speed is large or 10 r. p. m. or above, the output of the voltage value command is increased or decreased by 5 bits, for example, at step S37. After the voltage value command is changed in the manner described above, the rotational speed of the motor 3 is again detected. The detected rotational speed is then compared with the target rotational speed so that the rotationl speed of the motor 3 is controlled in the manner as described above.
The above-described control manner is performed both in the forward and backward rotation of the motor 3.
Consequently, when the difference between the detected rotational speed and the target rotational speed is large, the voltage applied to the motor 3 is increased or decreased by an amount larger than in the case where the difference is small. As a result, the target rotational speed can be reached by the drive motor 3 in a short period of time.
Differing from the conventional arrangement wherein the applied voltage is increased or decreased by a predetermined value by the feedback control, the target rotational speed of the motor 3 can be reached in a short period of time even when the position of the clothes in the rotational tub or another cause rapidly changes the rotational speed of the motor 3.
Although the voltage value command is changed in two stages in the foregoing embodiment, it may be changed in three or more stages.
The foregoing disclosure and drawings are merely illustrative of the present invention and are not to be interpreted in a limiting sense. The only limitation is to be determined from the scope of the appended claims.

Claims (3)

1. A washing machine comprising: a) an agitator driven for agitating clothes to be washed; b) a motor for driving the agitator; c) motor drive control means for controlling a voltage applied to the motor in accordance with a voltage value command; d) rotational speed detecting means for detecting the rotational speed of the motor; e) rotational speed command means for producing a command of a target rotational speed for the motor; f) voltage command means for supplying the motor drive control means with a value of voltage applied to the motor based on the command of the target rotational speed produced by the voltage command means; and g) voltage value command changing means comparing the rotational speed of the motor detected by the rotational speed detecting means with the target rotational speed produced by the rotational speed command means, the voltage value command changing means changing the voltage value command produced by the voltage command means in accordance with the difference between the rotational speed of the motor and the target rotational speed.
2. A washing machine according to claim 5, wherein the voltage value command changing means changes the voltage value command stepwise in accordance with the difference between the detected rotational speed of the motor and the target rotational speed.
3. A washing machine substantially as herein described with reference to the accompanying drawings.
GB9415821A 1990-08-28 1991-08-02 Clothes washing machine Expired - Fee Related GB2280519B (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2226917A JP2786729B2 (en) 1990-08-28 1990-08-28 Washing machine
GB9116721A GB2247579B (en) 1990-08-28 1991-08-02 Clothes washing machine

Publications (3)

Publication Number Publication Date
GB9415821D0 GB9415821D0 (en) 1994-09-28
GB2280519A true GB2280519A (en) 1995-02-01
GB2280519B GB2280519B (en) 1995-05-10

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ID=26299343

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9415821A Expired - Fee Related GB2280519B (en) 1990-08-28 1991-08-02 Clothes washing machine

Country Status (1)

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GB (1) GB2280519B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011122849A2 (en) * 2010-03-30 2011-10-06 엘지전자 주식회사 Motor control method and device, and washing machine and control method

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4371819A (en) * 1980-12-11 1983-02-01 Pako Corporation Pulse width modulation speed control
WO1983002341A1 (en) * 1981-12-21 1983-07-07 Beckman Instruments Inc Improved motor speed control system
US4623827A (en) * 1985-02-09 1986-11-18 Ricoh Company, Ltd. Device for controlling motor rotation speed
US4749927A (en) * 1986-04-11 1988-06-07 Ampex Corporation Adaptive digitally controlled motor drive system and method
EP0310116A2 (en) * 1987-10-02 1989-04-05 Mitsubishi Denki Kabushiki Kaisha Motor driving power supply apparatus including switching regulator control loop
EP0331259A1 (en) * 1988-03-04 1989-09-06 Whirlpool Europe B.V. Control circuit for a permanent magnet or constant excitation direct current motor, particularly for washing machines

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4371819A (en) * 1980-12-11 1983-02-01 Pako Corporation Pulse width modulation speed control
WO1983002341A1 (en) * 1981-12-21 1983-07-07 Beckman Instruments Inc Improved motor speed control system
US4623827A (en) * 1985-02-09 1986-11-18 Ricoh Company, Ltd. Device for controlling motor rotation speed
US4749927A (en) * 1986-04-11 1988-06-07 Ampex Corporation Adaptive digitally controlled motor drive system and method
EP0310116A2 (en) * 1987-10-02 1989-04-05 Mitsubishi Denki Kabushiki Kaisha Motor driving power supply apparatus including switching regulator control loop
EP0331259A1 (en) * 1988-03-04 1989-09-06 Whirlpool Europe B.V. Control circuit for a permanent magnet or constant excitation direct current motor, particularly for washing machines

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011122849A2 (en) * 2010-03-30 2011-10-06 엘지전자 주식회사 Motor control method and device, and washing machine and control method
WO2011122849A3 (en) * 2010-03-30 2013-07-18 엘지전자 주식회사 Motor control method and device, and washing machine and control method

Also Published As

Publication number Publication date
GB9415821D0 (en) 1994-09-28
GB2280519B (en) 1995-05-10

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 20070802