Water draining method of washing machine

Abstract

Disclosed is a water draining method of a washing machine. The water draining method comprises the following steps in order: a draining step, controlling a water drainage pump ( 4 ) to work intermittently until the water level inside an outer drum ( 2 ) reaches a set drainage water level; and a spin-drying step, controlling the electric motor to drive the inner drum to rotate to remove water, while also controlling the water drainage pump ( 4 ) to work intermittently. By controlling the water drainage pump ( 4 ) to work intermittently, when the water drainage pump ( 4 ) is working, the washing water inside the outer drum ( 2 ) enters a water drain pipe ( 3 ), and is then pumped by the water drainage pump ( 4 ) to be discharged via a riser segment of the water drain pipe ( 3 ); when the water drainage pump ( 4 ) stops working, the washing water in the riser segment of the water drain pipe ( 3 ) flows back under the action of gravity, and the water drainage pump ( 4 ) alternately working and stopping makes the washing water in the riser segment also flow back intermittently, and that facilitates foam floating on the washing water being discharged outside the washing machine. Therefore, the rinsing effect of the washing machine is improved and foam overflow is avoided.

1 . A water draining method of washing machine, wherein the washing machine is an upper-drain type and further including a first outer container configured to receive washing water, a first inner container provided within the first outer container, a motor configured to drive the first inner container rotating, a first draining system, which is communicated with the bottom of the first outer container, including a first draining conduit and a draining pump, comprising:
 initiating a drain cycle, during which keeping the draining pump working at an alternate operation mode until the liquid level within the first outer container decreasing to a preset draining level; and   initiating a spin cycle, during which controlling the motor to drive the first inner container rotating and spinning while keeping the draining pump working at an alternate operation mode.   
     
     
         2 . The water draining method according to  claim 1 , wherein the alternate operation mode comprising keeping the draining pump running 10 to 20 seconds and pausing 2 to 10 seconds alternately. 
     
     
         3 . The water draining method according to  claim 1 , further comprising:
 initiating a load balancing cycle before the spin cycle, during which controlling the motor to drive the first inner container spinning at a set distributed rotation speed and during which determining whether the load is evenly distributed based on rotation speed values detected.   
     
     
         4 . The water draining method according to  claim 3 , wherein the load balancing cycle further comprising:
 detecting real-time rotation speed values of the driveshaft of the motor at a plurality of points respectively;   comparing those detected speed values with set values corresponding to each of them; and   determining the fact that the laundry load is evenly distributed within the first inner container if all of the differences between the detected speed values and the set values belong to a preset range and terminating the load balancing cycle; or determining the fact that the laundry load is unevenly distributed within the first inner container if any one of the difference value is beyond the set range and resuming the load balancing cycle.   
     
     
         5 . The water draining method according to  claim 4 , wherein the spin cycle further comprising a low-speed spin, the low-speed spin comprising:
 a. controlling the motor to drive the first inner container spinning at an increasing rotation speed while keeping the draining pump working at the alternate operation mode; wherein the highest rotation speed capable of reaching in the low-speed spin is set as a first rotation speed;   b. determining whether an over-suds condition occurs in the washer by detecting the liquid level within the first outer container; if the over-suds condition occurs, then entering into a step c followed; if the over-suds condition does not occur, entering into a defoaming mode and then back to the step a sequentially; wherein the defoaming mode comprises: reducing the rotation speed of the first inner container to the distributed rotation speed, and sequentially supplying fresh water into the washer in a period while keeping the draining pump working at the alternate operation mode;   c. detecting the rotation speed of the first inner container and determining whether it meets the first rotation speed or not; if the rotation speed reaches the first rotation speed, the low-speed spin ends; if the rotation speed is lower than the first rotation speed, performing the defoaming mode and back to step a sequentially.   
     
     
         6 . The water draining method of  claim 5 , wherein the alternate operation mode in the low-speed spin is keeping the draining pump running 8 to 12 seconds and pausing 2 to 6 seconds alternately. 
     
     
         7 . The water draining method of  claim 5 , wherein the occurrence of the over-suds condition is determined by comparing the liquid level within the first outer container with a preset foaming liquid level; if the liquid level within the first outer container detected is higher than or meets the set foaming liquid level, the over-suds condition exists in the first outer container. 
     
     
         8 . The water draining method of  claim 5 , wherein the spin cycle further comprising a high-speed spin, the high-speed spin comprising:
 A. controlling the motor to drive the first inner container spinning at an increasing rotation speed while keeping the draining pump working at the alternate operation mode; wherein the highest rotation speed capable of reaching in the high-spin is set as a second rotation speed;   B. determining whether an over-suds condition is occurred in the washer by detecting whether the rotation speed reaches the second rotation speed in a set period of time; if an over-suds condition does not occur, the high-speed spin ends and the motor is being stopped; if an over-suds condition occurs, entering a deforming mode and back to the step A sequentially; wherein the deforming mode comprising: reducing the rotation speed of the first inner container to the distributed rotation speed, and sequentially supplying fresh water into the washer in a period while keeping the draining pump working at the alternate operation mode.   
     
     
         9 . The water draining method of  claim 8 , further comprising a timing spin followed the high-speed spin, wherein the timing spin comprising: increasing the rotation speed of the first inner container which is driven by the motor to a third rotation speed and spinning while keeping the draining pump working at the alternate operation mode; stopping the motor and shutting down a first draining valve as the time expires. 
     
     
         10 . The water draining method of  claim 1 , which is utilized in a dual-drum washing machine further including a second washing system, wherein the second washing system including a second outer container, a second draining conduit communicated with the second outer container, a second draining valve provided on the second draining conduit; the first draining conduit further including a bottom section, which is communicated with the first outer container and provided with a first draining valve and the draining pump, an upward section and a free section, and the second draining conduit connected with the portion of the bottom section between the first draining valve and the first draining conduit;
 further comprising:   initiating an occupation detecting cycle preceding the drain cycle, during which sensing whether the draining pump is working for another washing system; if it is being occupied, remaining the current status.