Washing machine with drying function

Abstract

A washing machine with a drying function includes a water tub, a rotating tub mounted in the water tub so as to be rotatable, a driver rotating the rotating tub, a circulation passage defined so as to communicate with the water tub, a warm-air supply unit circularly supplying warm air through the circulation passage into the water tub and the rotating tub, a water-supply unit supplying water into the water tub, a control unit controlling the driver, the warm-air supply unit and the water-supply unit thereby to be capable of controlling wash, rinse, dehydration and drying steps, and a preheating unit executing a preheating operation in which warm air is supplied into the water tub and the rotating tub during rotation of the rotating tub before the wash step is executed.

1 . A washing machine with a drying function, comprising: 
 a water tub;    a rotating tub provided in the water tub so as to be rotatable;    a driver rotating the rotating tub;    a circulation passage defined so as to communicate with the water tub;    a warm-air supply unit circularly supplying warm air through the circulation passage into the water tub and the rotating tub;    a water-supply unit supplying water into the water tub;    a control unit controlling the driver, the warm-air supply unit and the water-supply unit thereby to be capable of controlling wash, rinse, dehydration and drying steps; and    a preheating unit executing a preheating operation in which warm air is supplied into the water tub and the rotating tub during rotation of the rotating tub before the wash step is executed.    
   
   
       2 . The washing machine according to  claim 1 , wherein the preheating unit executes the preheating operation while a small amount of water is reserved in the water tub.  
   
   
       3 . The washing machine according to  claim 1 , further comprising a heat exchanger including a water pouring unit provided midway in the circulation passage for pouring water for dehumidification of air passing through the circulation passage, wherein the preheating unit executes the preheating operation when the water pouring unit has poured water.  
   
   
       4 . The washing machine according to  claim 1 , wherein the wash step includes a main wash and a preliminary wash carried out while water whose amount is smaller than in the main wash is reserved in the wash tub.  
   
   
       5 . The washing machine according to  claim 1 , further comprising a laundry temperature sensor detecting a temperature of laundry in the rotating tub, wherein the preheating unit executes the preheating operation until the temperature of laundry reaches a previously set target temperature.  
   
   
       6 . The washing machine according to  claim 5 , wherein the target temperature is set to 60° or below.  
   
   
       7 . The washing machine according to  claim 5 , further comprising an ambient temperature sensor detecting an ambient temperature, wherein the target temperature is changed according to the ambient temperature.