Washing machine and method of controlling the same

Abstract

A washing machine which prevents wash water in a plurality of tubs from being simultaneously drained, and a method of controlling the washing machine. The washing machine includes a plurality of tubs, a plurality of drain devices to discharge wash water in the plurality of tubs to the outside, and a control device connected to the plurality of tubs to selectively drain the wash water in the plurality of tubs.

1 . A washing machine comprising:
 a plurality of tubs;   a plurality of drain devices to discharge wash water in the plurality of tubs to the outside; and   a control device connected to the plurality of tubs to selectively drain the wash water in the plurality of tubs.   
     
     
         2 . The washing machine according to  claim 1 , wherein:
 the plurality of tubs includes a first tub and a second tub; and   the plurality of drain devices includes a first drain device connected to the first tub, and a second drain device connected to the first tub and the first drain device.   
     
     
         3 . The washing machine according to  claim 2 , wherein:
 the first drain device includes a first drain pipe provided with one end communicated with the first tub and the other end extended to the outside; and   the second drain device includes a second drain pipe provided with one end communicated with the second tub and the other end communicated with the first drain pipe, and a drain valve to open and close the second drain pipe.   
     
     
         4 . The washing machine according to  claim 3 , wherein the first drain device further includes a drain valve to open and close the first drain pipe. 
     
     
         5 . The washing machine according to  claim 3 , wherein the first drain device further includes a drain pump provided downstream of a junction of the first drain pipe and the second drain pipe. 
     
     
         6 . The washing machine according to  claim 3 , wherein:
 the other end of the second drain pipe is extended to the outside of the main body; and   the first drain device further includes a connection pipe provided with one end communicated with the first drain pipe and the other end communicated with the second drain pipe.   
     
     
         7 . The washing machine according to  claim 6 , wherein at least one of the connection pipe and the second drain pipe includes a connector to facilitate connection between the connection pipe and the second drain pipe. 
     
     
         8 . The washing machine according to  claim 4 , wherein the control device is a microcomputer to selectively open and close the first and second drain valves. 
     
     
         9 . The washing machine according to  claim 8 , wherein the microcomputer closes the second drain valve and opens the first drain valve when draining the first tub. 
     
     
         10 . The washing machine according to  claim 8 , wherein the microcomputer closes the first drain valve and opens the second drain valve when draining the second tub. 
     
     
         11 . The washing machine according to  claim 2 , wherein, when instructions indicating simultaneous draining of the first and second tubs are input to the control device, the control device first drains any one of the first and second tubs and then drains the other one of the first and second tubs. 
     
     
         12 . The washing machine according to  claim 3 , wherein the control device is an opening and closing device to selectively open and close the first and second drain pipes by flows of wash water in the first and second drain pipes. 
     
     
         13 . The washing machine according to  claim 12 , wherein the opening and closing device includes an opening and closing member provided to be rotatable by the flows of wash water in the first and second drain pipes. 
     
     
         14 . The washing machine according to  claim 13 , wherein the opening and closing device further includes stoppers to prevent excessive rotation of the opening and closing member. 
     
     
         15 . The washing machine according to  claim 14 , wherein the stoppers include a first stopper to support the opening and closing member, if the opening and closing member closes the first drain valve, and a second stopper to support the opening and closing member, if the opening and closing member closes the second drain valve. 
     
     
         16 . The washing machine according to  claim 13 , wherein:
 the first drain device further includes a drain pump provided in the middle of the first drain pipe; and   the opening and closing member, when the drain pump is driven, is rotated by a pump pressure of the drain pump and thus opens the first drain pipe and closes the second drain pipe.   
     
     
         17 . The washing machine according to  claim 16 , wherein:
 the second tub is disposed above the first tub; and   the opening and closing member, when only the drain valve among the drain valve and the drain pump is driven, is rotated by the pressure of wash water in the second tub and thus opens the second drain pipe and closes the first drain pipe.   
     
     
         18 . The washing machine according to  claim 1 , wherein the plurality of tubs includes a first tub and a second tub disposed at upper and lower parts of the washing machine, respectively. 
     
     
         19 . A washing machine comprising:
 a first tub;   a second tub disposed above the first tub;   a first drain pipe to discharge wash water in the first tub to the outside;   a second drain pipe to discharge wash water in the second tub to the outside; and   an opening and closing device to selectively open and close the first and second drain pipes.   
     
     
         20 . The washing machine according to  claim 19 , wherein the opening and closing device closes the second drain pipe while opening the first drain pipe, and closes the first drain pipe while opening the second drain pipe. 
     
     
         21 . The washing machine according to  claim 19 , further comprising:
 a drain pump provided in the middle of the first drain pipe; and   a drain valve provided in the middle of the second drain pipe.   
     
     
         22 . The washing machine according to  claim 19 , wherein the opening and closing device is an opening and closing member moving by pressures of wash water in the first and second drain pipes. 
     
     
         23 . The washing machine according to  claim 22 , wherein the opening and closing member is rotatably connected to a connection portion between the first and second drain pipes. 
     
     
         24 . A washing machine comprising:
 a first tub;   a second tub disposed above the first tub;   a first drain pipe to discharge wash water in the first tub to the outside;   a second drain pipe to discharge wash water in the second tub to the outside;   a pair of drain valves to respectively open and close the first and second drain pipes; and   a control device to selectively open and close the pair of drain valves.   
     
     
         25 . The washing machine according to  claim 24 , further comprising:
 a junction provided where the wash water in the first drain pipe and the wash water the second drain pipe are joined; and   a drain pump provided downstream of the junction.   
     
     
         26 . The washing machine according to  claim 25 , wherein the control device closes the drain valve to open and close the second drain pipe and drives the drain pump while opening the drain valve to open and close the first drain pipe. 
     
     
         27 . The washing machine according to  claim 25 , wherein the control device closes the drain valve to open and close the first drain pipe while opening the drain valve to open and close the second drain pipe. 
     
     
         28 . A method of controlling a washing machine, which has a plurality of tubs, and drain devices to discharge wash water in the plurality of tubs to the outside, comprising:
 judging whether or not drain cycles of all the plurality of tubs are performed; and   controlling the drain devices such that wash water in the plurality of tubs is sequentially drained, when it is judged that the drain cycles of all the plurality of tubs are performed.   
     
     
         29 . The method according to  claim 28 , wherein:
 the plurality of tubs includes first and second tubs; and   the sequential draining of the plurality of tubs is achieved by first draining any one of the first and second tubs and then draining the other one of the first and second tubs.