Washing Machine

Abstract

The present invention provides a washing machine configured such that a gas having a cleaning function is prevented from leaking to the outside. The washing machine performs an ozone cleaning step for cleaning dry laundry by supplying ozone to the laundry prior to a washing step. Before the start of the ozone cleaning step, a dehumidification water valve ( 14 ) is opened to once retain dehumidification water in a bottom of an outer tub ( 7 ). Then, water is retained in an overflow trap ( 45 ) by utilizing the dehumidification water, whereby a flow passage extending from the outer tub ( 7 ) to the outside is sealed with the water. Further, a detergent valve ( 55 ) or a finishing agent valve ( 56 ) is opened to retain water in a water supply trap ( 24 ), whereby a flow passage extending from the outer tub ( 7 ) to the outside is sealed with the water.

1 . A washing machine comprising:
 a treatment tub in which laundry and water are contained, and washing, dehydrating and other operations are performed;   water supply means which supplies water to the treatment tub;   a drain passage through which the water contained in the treatment tub is drained to the outside;   an overflow passage through which excess water is drained if an amount of the water contained in the treatment tub is not less than a predetermined amount, the overflow passage being connected to the drain passage;   a drain trap provided as a part of at least one of the drain passage and the overflow passage for retaining water;   gas supply means which generates a laundry cleaning gas and supplies the gas into the treatment tub; and   water supply control means which controls the water supply means to retain water in the drain trap before the gas is supplied into the treatment tub.   
   
   
       2 . A washing machine as set forth in  claim 1  further comprising:
 a drain valve provided in the drain passage upstream of a junction of the overflow passage and the drain passage for opening and closing the drain passage;   wherein the water supply control means closes the drain valve and controls the water supply means to retain a predetermined amount of water in the treatment tub, and then opens the drain valve to retain water in the drain trap.   
   
   
       3 . A washing machine as set forth in  claim 2  further comprising:
 a water level sensor which detects a water level in the treatment tub;   wherein the water supply control means opens the drain valve to retain water in the drain trap if the water level sensor detects that the water level reaches a predetermined water level.   
   
   
       4 . A washing machine as set forth in  claim 3 , wherein the water supply control means performs a water supply error process if the water level sensor does not detect that the water level reaches the predetermined water level. 
   
   
       5 . A washing machine as set forth in  claim 3 , wherein, if a difference between a first water level detected by the water level sensor after a lapse of a first predetermined water supply period from start of water supply to the treatment tub and a second water level detected after a lapse of a second predetermined water supply period is not less than a predetermined threshold, the water supply control means opens the drain valve to retain water in the drain trap. 
   
   
       6 . A washing machine as set forth in  claim 1 ,
 wherein the water supply means includes:   a water supply passage through which water is introduced into the treatment tub;   a detergent containing portion provided in the water supply passage for containing a detergent and a finishing agent to be dissolved in the supplied water; and   a water supply trap provided in the water supply passage downstream of the detergent containing portion for retaining the supplied water,   wherein the water supply control means retains water in the water supply trap before the gas is supplied into the treatment tub.   
   
   
       7 . A washing machine as set forth in  claim 6 ,
 wherein the water supply passage includes a bypass water supply passage which bypasses the detergent containing portion to supply water into the treatment tub,   wherein the water supply control means supplies water through the bypass water supply passage to retain water in the water supply trap.   
   
   
       8 . A washing machine comprising:
 a treatment tub in which laundry and water are contained, and washing, dehydrating and other operations are performed;   a drain passage through which the water contained in the treatment tub is drained to the outside;   an overflow passage through which excess water is drained if an amount of the water contained in the treatment tub is not less than a predetermined amount, the overflow passage being connected to the drain passage;   a drain trap provided as a part of at least one of the drain passage and the overflow passage for retaining water;   gas supply means which generates a laundry cleaning gas and supplies the gas into the treatment tub;   an air circulation duct having opposite ends, one of which is connected to a lower portion of the treatment tub and the other of which is connected to a portion of the treatment tub other than the lower portion, and configured to circulate air flowing out of the treatment tub from the one end thereof to introduce the air into the treatment tub from the other end thereof;   dehumidification water supply means connected to the air circulation duct, and configured to supply dehumidification water into the air circulation duct for dehumidifying the air flowing through the air circulation duct; and   water supply control means which controls the dehumidification water supply means to supply water into the drain trap from the air circulation duct through the lower portion of the treatment tub to retain water in the drain trap before the gas is supplied into the treatment tub.   
   
   
       9 . A washing machine as set forth in  claim 8  further comprising:
 a drain valve provided in the drain passage upstream of a junction of the overflow passage and the drain passage for opening and closing the drain passage;   wherein the water supply control means closes the drain valve and controls the dehumidification water supply means to retain a predetermined amount of water in the treatment tub, and then opens the drain valve to retain water in the drain trap.   
   
   
       10 . A washing machine as set forth in  claim 4 , wherein, if a difference between a first water level detected by the water level sensor after a lapse of a first predetermined water supply period from start of water supply to the treatment tub and a second water level detected after a lapse of a second predetermined water supply period is not less than a predetermined threshold, the water supply control means opens the drain valve to retain water in the drain trap.