Device and Method for Preventing Foreign Matters from Adhering in Dishwasher

Abstract

Device and method for preventing foreign matters from adhering in a dishwasher, the device including a circulating pump including a washing motor for providing a driving source to pump up washing water from a sump, an impeller designed to receive driving force from the washing motor and rotate for pumping the washing water from the sump to spray nozzles, and a disposer designed to receive driving force from the washing motor and rotate, for removing foreign matters introduced together with the washing water, sensing means for sensing a rotation speed of the washing motor, and a system control unit for controlling a rotation direction and/or speed of the washing motor according to the rotation speed sensed at the sensing means, thereby preventing the washing motor from being restricted by food remnants to improve product reliability by providing means for effective removal of the food remnants adhered to the washing motor.

1 . A device for preventing foreign matters from adhering in a dishwasher comprising: 
 a circulating pump including a washing motor for providing a driving source to pump up washing water from a sump, an impeller designed to receive driving force from the washing motor and rotate for pumping the washing water from the sump to spray nozzles, and a disposer designed to receive driving force from the washing motor and rotate, for removing foreign matters introduced together with the washing water;    sensing means for sensing a rotation speed of the washing motor; and    a system control unit for controlling a rotation direction and/or speed of the washing motor according to the rotation speed sensed at the sensing means.    
     
     
         2 . The device as claimed in  claim 1 , wherein the sensing means is a hole sensor mounted on the washing motor.  
     
     
         3 . The device as claimed in  claim 1 , wherein the impeller and the disposer are mounted on a rotation shaft of the washing motor on a straight line so that the impeller and the disposer rotate together with the washing motor.  
     
     
         4 . The device as claimed in  claim 1 , wherein the impeller and the disposer are mounted on a rotation shaft of the washing motor on a straight line so that the impeller and the disposer rotate together with the washing motor, and the disposer is mounted on the rotation shaft between the washing motor and the impeller.  
     
     
         5 . The device as claimed in  claim 1 , wherein the disposer includes at least one blade for rotating and smashing foreign matters introduced together with the washing water.  
     
     
         6 . A device for preventing foreign matters from adhering in a dishwasher comprising: 
 a circulating pump having a washing motor and impeller, for pumping washing water from a sump;    a hole sensor for sensing a rotation speed of the washing motor; and    a system control unit for rotating the washing motor in one direction under a washing cycle order, sensing a rotation speed of the washing motor through the hole sensor at fixed intervals during the washing cycle is progressed, and controlling a rotation direction of the washing motor according to the rotation speed of the washing motor.    
     
     
         7 . The device as claimed in  claim 6 , wherein the system control unit determines that the washing motor is in a restricted state if the rotation speed of the washing motor sensed is lower than a preset level, and changes the present rotation direction of the washing motor in an opposite direction.  
     
     
         8 . The device as claimed in  claim 6 , wherein the system control unit determines that the washing motor is in a restricted state if the rotation speed of the washing motor sensed is lower than a preset level, and alternates the rotation direction of the washing motor, repeatedly.  
     
     
         9 . A method for preventing foreign matters from adhering in a dishwasher comprising: 
 a first step for rotating a washing motor of a circulating pump in a first direction upon starting of a washing cycle, and sensing rotation speed of the washing motor at fixed intervals; and    a second step for controlling a rotation direction of the washing motor according to the rotation speed of the washing motor sensed.    
     
     
         10 . The method as claimed in  claim 9 , wherein the first step includes the steps of; 
 setting the rotation direction of the washing motor to the first direction upon reception of a cycle starting order from a user for pumping up the washing water,    starting rotation of the washing motor in the set first direction, and    reading the rotation speed of the washing motor at fixed intervals during the washing motor is rotated in the first direction.    
     
     
         11 . The method as claimed in  claim 9 , wherein the second step includes the steps of; 
 performing the washing cycle while maintaining the rotation direction of the washing motor in the first direction if the rotation speed of the washing motor sensed is higher than a preset level, and    determining that the washing motor is in a restricted state if the rotation speed of the washing motor sensed is lower than the preset level, and changing the rotation direction of the washing motor for a preset time period, to perform a foreign matter removal cycle.    
     
     
         12 . The method as claimed in  claim 9 , wherein the second step includes the steps of; 
 performing the washing cycle while maintaining the rotation direction of the washing motor in the first direction if the rotation speed of the washing motor sensed is higher than a preset level, and    determining that the washing motor is in a restricted state if the rotation speed of the washing motor sensed is lower than the preset level, and changing the present rotation direction of the washing motor to a second direction opposite to the first direction for a preset time period, to perform a foreign matter removal cycle.    
     
     
         13 . The method as claimed in  claim 9 , wherein the second step includes the steps of; 
 performing the washing cycle while maintaining the rotation direction of the washing motor in the first direction if the rotation speed of the washing motor sensed is higher than a preset level, and    determining that the washing motor is in a restricted state if the rotation speed of the washing motor sensed is lower than the preset level, and alternating the rotation direction of the washing motor in the first, and the second directions different from each other for a preset time period, to perform a foreign matter removal cycle.    
     
     
         14 . The method as claimed in  claim 9 , wherein the second step includes the steps of; 
 performing the washing cycle while maintaining the rotation direction of the washing motor in the first direction if the rotation speed of the washing motor sensed is higher than a preset level,    determining that the washing motor is in a restricted state if the rotation speed of the washing motor sensed is lower than the preset level, and changing the rotation direction of the washing motor for a preset time period, to perform a foreign matter removal cycle,    sensing the rotation speed of the washing motor while rotating the washing motor in the first direction again, if the foreign matter removal cycle is finished,    performing the washing cycle while maintaining the rotation direction of the washing motor in the first direction, if the rotation speed of the washing motor sensed after the foreign matter removal cycle is higher than the preset level, and    displaying an error state of the washing motor, if the rotation speed of the washing motor sensed after the foreign matter removal cycle is lower than the preset level.