Household laundry washing machine with improved spinning phase

Abstract

Washing machine comprising a rotating drum, an electric motor apt to put the drum into rotation, measurement means of the drum rotational speed, means able to detect the torque provided by said motor, computing and control means able to determine and control the instantaneous speed of the drum, wherein, before of the spinning phase, said computing and control means activates the machine into rotation at a predefined speed (Wmain) with the laundry retained on the drum inner wall, compute the static unbalance (m) and the elevation moment (Mel), check if both the following conditions are met: the static unbalance mass (m) is less than a pre-determined value and the absolute value of the elevation moment is less of a predetermined value; if at least one of the unbalancing mass values, or one of the values of said elevation momentum (Mel) are higher than a predetermined respective values, said computing means calculate the difference between the value of said unbalancing mass and the respective said predetermined maximum value, and if said difference is higher than a predetermined limit, said computing and control means will command a predermined speed increase; if not, they command a predetermined speed reduction.

1 . Washing or washing-drying machine comprising: 
 a rotating drum,    an electric motor apt to put the drum into rotation,    measurement means of the drum rotational speed,    means able to detect the torque provided by said motor,    computing and control means able to determine and control the instantaneous speed,    characterized in that, before of beginning the spinning phase, said computing and control means:    do make the measurement of the total drum inertia (J TOTAL ),    activate the machine into rotation at a predefined speed Ω MAIN  (2) corresponding to a complete laundry distribution retained on the drum inner cylindrical surface,    compute the static unbalance mass (m) and the elevation torque (T ELEVATION ).    
   
   
       2 . Washing machine according to  claim 1 , characterized in that, after having performed the operation of  claim 1 , said computing and control means determine a working mode according to which they activate the spinning phase if both of the following conditions are met: 
 the static unbalance mass (m) is less than a pre-determined value (S) ( 6 ), and the absolute value of the elevation torque is less than a predetermined value (T ELEVATION   MAX ) ( 7 ),    said unbalance mass and said elevation torque being calculated according to the drum total inertia, and said conditions being checked also in times not successive to said calculations.    
   
   
       3 . Machine according to  claim 2 , characterized in that, is at least one of the unbalance mass values (m), on or more of the absolute values of the elevation torque (T ELEVATION ) are higher than the respective predetermined values, (S, T ELEVATION ), said computing means calculate the difference between the value of said unbalance mass (m) and the respective said predetermined maximum Value (S), and if said difference is less than a predetermined limit (β·|T ELEVATION |) (9), said computing and control means will command a predetermined speed increase ( 10 ).  
   
   
       4 . Machine according to  claim 2 , characterized in that, if at least one of the values of said unbalance mass (m) or of said absolute value of the elevation torque (T ELEVATION ) are higher of a respective pre-defined value, said computing means calculate the difference between the value of said unbalance mass (m) and the respective said maximum predetermined limit (S), and if said difference is higher than a predetermined limit (β·|T ELEVATION |) said computing and control means will command to the drum a predetermined speed reduction ( 12 ).  
   
   
       5 . Machine according to  claim 3  or  4 , characterized in that, after having achieved said predetermined speed increase or decrease, said computing means check whether the resulting speed is comprised into a pre-defined interval (Ω MINd ÷Ω MAZd  ( 27 ,  28 ) and if such condition is positively met, a further comparison is made ( 29 ) whether the working time from the beginning of the operation as per  claim 1  is less than a predefined maximum time interval t M , and if such condition is met the machine operation is brought to the beginning of  claim 2  ( 5 ).  
   
   
       6 . Machine according to  claim 3  or  4 , characterized in that of the resulting speed is outside of a predefined speed interval (Ω MINd ÷Ω MAZd ), said computing and control mans activate the drum to rotate at a predefined speed (Ω MINd  or Ω MAZd ) ( 27 B,  28 B) and after that a further comparison is made ( 29 ) whether the working time from the beginning of the operation as per  claim 1  is less than a predefined maximum time interval (t M ), and if such condition is met the machine operation is brought to the beginning of  claim 2 .  
   
   
       7 . Machine according to  claim 1 , characterized in that said computing and control means are able to perform the following operation: before of commanding the spinning phase, they command the drum speed ( 21 ) to the predetermined speed (Ω MAIN ) as in  claim 1 , and then the machine operation is brought to the beginning of  claim 2 .  
   
   
       8 .  8 . Machine according to  claim 7 , characterized in that, after having determined the drum speed, it is able of check that: 
 the drum speed is the same of said predetermined speed (Ω MAIN ,  23 ), and    said unbalance mass (m) is less of a predetermined value (S;  24 ),    and if said check gives a positive result, it increments the number of said operations in a specific adding register ( 25 ),    and if the actual number in said register is the same of a predetermined number (N,  26 ), then said computing and control means command the spinning phase.—