Washing machine

Abstract

The present invention relates to a washing machine. The washing machine includes a tub ( 20 ) for holding washing water, the tub ( 20 ) having a plurality of venting portions ( 200, 201 ) formed on an outside circumferential surface, a drum ( 30 ) rotatably mounted in the tub ( 20 ), and a blocking member ( 300, 322 ) for blocking discharge of air from the tub ( 20 ) through the venting portions ( 200, 201 ) in spin-drying.

1 . A washing machine comprising:
 a drum having an opening at a front portion thereof to allow laundry to be entered through;   a tub in which the drum is rotatably placed and water for washing is held, the tub having at least one venting portion on a circumferential surface thereof behind the opening of the drum; and   a blocking member for blocking discharge of air from the tub through the venting portion spin-drying when a spin-drying is performed.   
     
     
         2 . The washing machine as claimed in  claim 1 , wherein the blocking member blocks the discharge when the drum reaches to a preset rotation speed. 
     
     
         3 . The washing machine as claimed in  claim 2 , wherein the preset rotation speed is over 400 RPM. 
     
     
         4 . The washing machine as claimed in  claim 1 , wherein the blocking member blocks the discharge when an inside pressure of the tub reaches a pressure higher than a preset pressure at the time of high speed rotation of the drum. 
     
     
         5 . The washing machine as claimed in  claim 4 , further comprising a pressure sensor to sense the inside pressure. 
     
     
         6 . The washing machine as claimed in  claim 4 , wherein the blocking member includes a pressure valve which is closed at the preset pressure. 
     
     
         7 . The washing machine as claimed in  claim 1 , wherein the tub has a hole in front of the opening of the drum to allow air to flow into the drum when the spin-drying is performed. 
     
     
         8 . The washing machine as claimed in  claim 1 , wherein the blocking member includes a check valve member. 
     
     
         9 . The washing machine as claimed in  claim 8 , wherein the check valve member is of a passive control type. 
     
     
         10 . The washing machine as claimed in  claim 9 , wherein the check valve member is a flapper. 
     
     
         11 . The washing machine as claimed in  claim 9 , wherein the check valve member includes a blocking portion of shape memory alloy for blocking the second venting portion as the blocking portion is unfolded by a steam temperature when steam discharges through the venting portion. 
     
     
         12 . The washing machine as claimed in  claim 9 , wherein the check valve member is of a floating type, which includes;
 a supporting portion for closing the venting portion when a washing is performed, the supporting portion having a side opening for venting the air, and   a floating portion movably mounted to the supporting portion having an opening to be in communication with the side opening, for moving upward when a pressure difference is generated by detergent foam or steam to close the side opening.   
     
     
         13 . The washing machine as claimed in  claim 8 , wherein the check valve member is of an active control type. 
     
     
         14 . The washing machine as claimed in  claim 8 , wherein the check valve member is of a magnet type which opens or closes the venting portion by magnetic force. 
     
     
         15 . The washing machine as claimed in  claim 14 , wherein the check valve member includes;
 a magnetic force supply portion mounted in the venting portion for supplying magnetic force if the power is supplied to the washing machine,   a fixed plate fixed to an inside of the magnetic force supply portion having a central hole, and   a movable plate mounted under the fixed plate for moving upward when the magnetic force is supplied to close the central hole.   
     
     
         16 . The washing machine as claimed in  claim 15 , wherein the check valve member further includes a stopper projected from an underside of the magnetic force supply portion for supporting the movable plate which moves down by gravity when the magnetic force is turned off from an underside of the movable plate. 
     
     
         17 . The washing machine as claimed in  claim 1 , wherein the venting portion is formed at a rear of a top side of the tub, or at a center of the top side of the tub. 
     
     
         18 . The washing machine as claimed in  claim 17 , wherein the venting portion comprises a plurality of venting portions spin-drying and the blocking member comprises a plurality of blocking members corresponding to the plurality of venting portions. 
     
     
         19 . The washing machine as claimed in  claim 1 , further comprising:
 a driving unit including a rotation shaft, a bearing housing for rotatably supporting the rotation shaft, and a motor for rotating the rotation shaft, and   a flexible material to prevent the water inside the tub from leaking toward the driving unit and allow the driving unit to move relatively to the tub.   
     
     
         20 . The washing machine as claimed in  claim 1 , further comprising:
 a driving unit including a rotation shaft, a bearing housing for rotatably supporting the rotation shaft, and a motor for rotating the rotation shaft, and   a suspension unit attached to the bearing housing for reducing vibration of the drum.   
     
     
         21 . The washing machine as claimed in  claim 1 , wherein the tub is supported more rigidly than the drum is.