Washing machine

Abstract

A direct drive washing machine is disclosed which is capable of performing a washing operation by efficiently converting electric energy supplied into an electric motor ( 10 ) into mechanical energy or with less vibration and noise. When a washing operation is carried out with efficient energy conversion, an acceleration time and a deceleration time of an agitator ( 8 ) rotated by the motor ( 10 ) are controlled on the basis of a measured value of a vibration sensor ( 25 ) or a measured value of clothes weight so that vibration of a water-receiving tub ( 4 ) becomes maximum. On the other hand, when a quiet washing operation with less vibration is carried out, the acceleration time and the deceleration time of an agitator ( 8 ) rotated by the motor ( 10 ) are controlled on the basis of the measured value of the vibration sensor ( 25 ) or the measured value of clothes weight so that vibration of the water-receiving tub ( 4 ) becomes minimum.

1 . A washing machine which comprises: 
 a water-receiving tub elastically suspended in an outer cabinet;    a rotating tub provided in the water-receiving tub;    an agitator provided in the rotating tub;    an electric motor provided on an underside of the water-receiving tub for direct driving the agitator; and    a control device controlling the motor and the overall washing machine, characterized in that the control device controls either one or both of an acceleration time and a deceleration time of the motor in a washing operation so that vibration of the water-receiving tub becomes maximum.    
   
   
       2 . A washing machine according to  claim 1 , characterized in that the control device detects a weight of clothes put into the rotating tub prior to the washing operation and subsequently reads an acceleration time corresponding to a detected weight value from a chart storing relationship between weight of clothes and an acceleration time required for the vibration of the water-receiving tub to become maximum corresponding to the weight of clothes, and that the control device controls either one or both of the acceleration time and the deceleration time of the motor in the washing operation so that the acceleration time and/or the deceleration time corresponds to the read time.  
   
   
       3 . A washing machine which comprises: 
 a water-receiving tub elastically suspended in an outer cabinet;    a rotating tub provided in the water-receiving tub;    an agitator provided in the rotating tub;    a vibration sensor detecting vibration of the water-receiving tub;    an electric motor provided on an underside of the water-receiving tub for direct driving the agitator; and    a control device controlling the motor and the overall washing machine, characterized in that the control device controls either one or both of an acceleration time and a deceleration time of the motor in a washing operation so that a value of vibration detected by the vibration sensor during the wash operation becomes maximum.    
   
   
       4 . A washing machine which comprises: 
 a water-receiving tub elastically suspended in an outer cabinet;    a rotating tub provided in the water-receiving tub;    an agitator provided in the rotating tub;    an electric motor provided on an underside of the water-receiving tub for direct driving the agitator; and    a control device controlling the motor and the overall washing machine, characterized in that the control device controls either one or both of an acceleration time and a deceleration time of the motor in a washing operation so that vibration of the water-receiving tub becomes minimum.    
   
   
       5 . A washing machine according to  claim 4 , characterized in that the control device detects a weight of clothes put into the rotating tub prior to the washing operation and subsequently reads an acceleration time corresponding to a detected weight value from a chart storing relationship between weight of clothes and an acceleration time required for the vibration of the water-receiving tub to become maximum corresponding to the weight of clothes, and that the control device controls either one or both of the acceleration time and the deceleration time of the motor in the washing operation so that the acceleration time and/or the deceleration time corresponds to the read time.  
   
   
       6 . A washing machine which comprises: 
 a water-receiving tub elastically suspended in an outer cabinet;    a rotating tub provided in the water-receiving tub;    an agitator provided in the rotating tub;    a vibration sensor detecting vibration of the water-receiving tub;    an electric motor provided on an underside of the water-receiving tub for direct driving the agitator; and    a control device controlling the motor and the overall washing machine, characterized in that the control device controls either one or both of an acceleration time and a deceleration time of the motor in a washing operation so that a value of vibration detected by the vibration sensor during the wash operation becomes minimum.