Patent Publication Number: US-2005126601-A1

Title: Dishwashing machine and method for controlling the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims the benefit of Korean Patent Application No. 2003-91388, filed on Dec. 15, 2003 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a dishwashing machine using heated wash water and a method for controlling the same, and more particularly to a dishwashing machine in which tableware is washed by heated wash water and is then dried by circulated hot air, and a method for controlling the dishwashing machine  
      2. Description of the Related Art  
      A dishwashing machine has a box-shaped structure provided with an opened front surface, and comprises a main body having a washing compartment in which tableware to be washed is contained and a door to open and close the opened front surface.  
      A tableware basket for stably mounting the tableware thereon and washing the tableware by means of sprayed wash water is installed in the washing compartment, and a collecting reservoir for collecting the wash water therein, a wash water circulating unit for circulating the wash water, and a discharging unit for discharging the wash water are installed under the washing compartment. Further, a plurality of spraying nozzles, connected to the wash water circulating unit, for spraying the wash water to the tableware basket are arranged in the washing compartment. The dishwashing machine further comprises a heating unit for heating the wash water, and a hot air circulating unit for circulating hot air to dry the tableware.  
      The dishwashing machine is designed such that the door can be opened from the front surface of the main body even while the tableware is being washed or dried. Since the inner surface of the door, arranged adjacent to the heating unit, has a high temperature during the heating of the wash water, if the inner surface of the door comes into contact with a user when the door is opened from the front surface of the main body, the user may suffer burns. Further, in case that the door is opened when the tableware is being washed by the heated wash water, the heated wash water can flow from the main body through the door and contact the user.  
      Moreover, in case that hot air is being circulated for drying the tableware, if the door is opened from the front surface of the main body when the inner temperature of the washing compartment is very high, the hot air escapes to the outside through the door, thus causing startling and discomfort to the user.  
     SUMMARY OF THE INVENTION  
      Therefore, an aspect of the invention is to provide a dishwashing machine, in which opening of a door is restricted in a washing or drying mode, and a method for controlling the dishwashing machine, to provide safe and convenient use by consumers.  
      In accordance with one aspect, the present invention provides a dishwashing machine comprising: a washing compartment to wash tableware contained therein; a first heater heating wash water; a water temperature sensor sensing a temperature of the wash water; a door opening and closing the washing compartment; a door locking unit selectively locking the door; and a controller controlling the door locking unit to lock the door when the temperature of the wash water sensed by the water temperature sensor is greater than a first predetermined temperature.  
      According to one aspect, the controller controls the door locking unit to unlock the door when the temperature of the wash water sensed by the water temperature sensor is not greater than the first predetermined temperature:  
      According to one aspect, the door locking unit comprises a lever to lock the door, controlled by the controller.  
      According to one aspect, the dishwashing machine further comprises a water collecting reservoir collecting the wash water therein, wherein the first heater and the water temperature sensor are installed in the water collecting reservoir.  
      According to one aspect, the dishwashing machine further comprises spraying nozzles spraying the wash water heated by the first heater; and a motor pumping the wash water collected in the water collecting reservoir to the spraying nozzles to circulate the wash water.  
      According to one aspect, the dishwashing machine further comprises a hot air circulating unit circulating hot air into the washing compartment to dry the tableware; and a compartment temperature sensor sensing a temperature in the washing compartment.  
      According to one aspect, the hot air circulating unit comprises a second heater and a blowing fan.  
      According to one aspect, the compartment temperature sensor is installed adjacent to the second heater.  
      According to one aspect, the controller controls the door locking unit to lock the door when the temperature of the washing compartment sensed by the compartment temperature sensor is greater than a second predetermined temperature.  
      According to one aspect, the controller controls the door locking unit to unlock the door lock when the temperature of the washing compartment sensed by the compartment temperature sensor is not greater than a second predetermined temperature. [ 0018 ] In accordance with another aspect, the present invention provides a dishwashing machine comprising: a washing compartment to wash tableware contained therein; a wash water heater heating wash water; a dry heater heating air in the washing compartment; a water temperature sensor sensing a temperature of the wash water; a compartment temperature sensor sensing a temperature in the washing compartment; a door opening and closing the washing compartment; a door locking unit selectively locking the door; and a controller controlling the door locking unit by comparing at least one of the temperature of the wash water sensed by the water temperature sensor and the temperature of the washing compartment sensed by the compartment temperature sensor to a predetermined temperature.  
      According to one aspect, the controller controls the door locking unit to lock the door when the temperature of the wash water is greater than a first predetermined temperature or the temperature of the washing compartment is greater than a second predetermined temperature.  
      According to one aspect, the controller controls the door locking unit to unlock the door when the temperature of the wash water is not greater than the first predetermined temperature or the temperature of the washing compartment is not greater than the second predetermined temperature.  
      In accordance with yet another aspect, the present invention provides a method for controlling a dishwashing machine, comprising: heating wash water to wash tableware contained in a washing compartment; sensing a temperature of the wash water; comparing the sensed temperature of the wash water to a first predetermined temperature; and controlling a door locking unit to lock a door to the washing compartment when the sensed temperature of the wash water is greater than the first predetermined temperature.  
      According to one aspect, the controlling the door locking unit to lock the door to the washing compartment when the sensed temperature of the wash water is greater than the first predetermined temperature comprises controlling the door locking unit to unlock the door when the sensed temperature of the wash water in a door locked state is not greater than the first predetermined temperature.  
      According to one aspect, the method further comprises: circulating hot air into the washing compartment after the washing of the tableware; sensing a temperature in the washing compartment; comparing the sensed temperature in the washing compartment to a second predetermined temperature; and controlling the door locking unit to lock the door to the washing compartment when the sensed temperature in the washing compartment is greater than the second predetermined temperature.  
      According to one aspect, the controlling the door locking unit to lock the door to the washing compartment when the sensed temperature in the washing compartment is greater than the second predetermined temperature comprises controlling the door locking unit to unlock the door when the sensed temperature in the washing compartment is not greater than the second predetermined temperature.  
      Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, of which:  
       FIG. 1  is a perspective view of a dishwashing machine in accordance with an embodiment of the present invention;  
       FIG. 2  is a cross-sectional view of the dishwashing machine of  FIG. 1 , taken along the line II-II;  
       FIG. 3  is a block diagram illustrating a control process applied to the dishwashing machine of  FIG. 1 ; and  
       FIG. 4  is a flow chart illustrating a method of controlling the dishwashing machine of  FIG. 1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures.  
       FIGS. 1 and 2  illustrate a structure of a dishwashing machine in accordance with an embodiment of the present invention.  
      As is shown in  FIGS. 1 and 2 , the dishwashing machine comprises a box-shaped main body  1  provided with an opened front surface, and a door  5  to open and close the opened front surface of the main body  1 .  
      A door locking unit  30  to lock and unlock the door  5  is installed at the door  5 . The door locking unit  30  includes a lever  31  operated under the control of a controller, which will be described later. When the lever  31  is inserted into a groove (not shown) located in a corresponding position of the main body  1 , the door  5  is in a locked state. When the lever  31  is removed from the groove, the door  5  is in an unlocked state.  
      An input unit  2  allowing a user to set input instructions is provided at an outside of the main body  1 . A washing compartment  4 , in which tableware is washed, is positioned in the main body  1 .  
      A pair of tableware baskets  6  are respectively installed on upper and lower inner surfaces of the washing compartment  4  so that the tableware baskets  6  are movable back and forth. A water collecting reservoir  7 , a circulating motor  8  operating a circulating pump to circulate wash water, and a drain motor  9  operating a drain pump to discharge the wash water therethrough are positioned at a lower surface of the washing compartment  4 .  
      A first heater  12  heating the wash water, and a first temperature sensor  13  sensing the temperature of the heated wash water are installed in the water collecting reservoir  7 .  
      The wash water, which is collected in the water collecting reservoir  7 , is heated by the first heater  12 , pumped through a connection pipe  10  by the operation of the circulating motor  8 , and is sprayed by a plurality of spraying nozzles  11 , thereby being used to wash the tableware.  
      The dishwashing machine of the present invention further comprises a hot air circulating unit  20  circulating hot air to remove the remainder of the wash water from the tableware after the washing of the tableware.  
      The air circulating unit  20  includes a case  21  installed in the door  5 . The case  21  includes a second heater  25 , a blowing fan  23 , and a fan motor  24 . A cover unit  22  is connected to an opening of the case  21 , and provided with a plurality of air vents, formed therethrough, which serve to transfer the hot air blown by the air blowing fan  23  to the washing compartment  4  and to introduce the air circulated through the washing compartment  4  into the case  21 .  
      The dishwashing machine further comprises a second temperature sensor  26 , installed in the case  21 , sensing the temperature in the washing compartment  4 . Since the second temperature sensor  26  is installed in the case  21 , the second temperature sensor  26  recognizes the temperature of the hot air, which is heated by the second heater  25  and blown by the blowing fan  23 , as the inner temperature of the washing compartment  4 . According to one aspect, as long as the second temperature sensor  26  can sense the inner temperature of the washing compartment  4 , the second temperature sensor  26  may be installed in any place other than the case  21 .  
      With reference to  FIG. 3 , the dishwashing machine further comprises a controller  40  controlling an operation of washing the tableware with the heated wash water, an operation of drying the tableware with the hot air, and an operation of controlling the door lock according to the temperatures of the wash water and the washing compartment  4 .  
      The input unit  2  for allowing a user to set input instructions, the first temperature sensor  13  sensing the temperature of the wash water, and the second temperature sensor  26  sensing the temperature of the washing compartment  4  are electrically connected to an input terminal of the controller  40 .  
      A door locking unit operating unit  41  operating the door locking unit  30 , a circulating motor operating unit  42  operating the circulating motor  8  circulating the wash water, a drain motor operating unit  43  operating the drain motor  9  discharging the waste wash water after the washing of the tableware, a fan motor operating unit  44  operating the fan motor  24  forcibly blowing the heated air, and a heater operating unit  45  operating the first heater  12  installed in the water collecting reservoir  7  heating the wash water and the second heater  25  installed at the inner side of the door  5  generating hot air by heating are electrically connected to an output terminal of the controller  40 .  
      When the tableware is placed in the washing compartment  4 , and washed by the heated wash water or dried by the hot air, the controller  40  selectively restricts the opening of the door  5 .  
      Hereinafter, a method  100  for controlling the dishwashing machine will be described in detail with reference to the drawings.  
      After the door  5  is opened from the opened front surface of the main body  1  and the baskets  6  are drawn out, tableware to be washed is placed in the baskets  6 , the baskets  6  containing the tableware are drawn in, and then the door  5  is closed to the opened front surface of the main body  1 .  
      In operation  101 , the controller  40  operates the first heater  12  heating wash water supplied to the water collecting reservoir  7 . When the wash water is heated, the controller  40  operates the door locking unit  30  for locking the door  5  in-operation  103 . Since the lever  31  is inserted into the groove in a door locked state, the door  5  cannot be opened from the main body  1  even if a user grips and pulls the door  5  from the main body  1 . The controller  40  then operates the circulating motor  8  to spray the heated wash water on the tableware in operation  105 . The heated wash water is supplied to the spraying nozzles  11  through the connection pipe  10 , and is then sprayed onto the tableware, thus removing dried food residue from the tableware.  
      Next, in operation  107 , the first temperature sensor  13  senses the temperature of the wash water, and supplies a signal communicating the sensed temperature of the wash water to the controller  40 . The controller  40  receives the signal, and recognizes the signal as the temperature of the wash water. In operation  109 , the controller  40  compares the temperature of the wash water to a first predetermined temperature. That is, the controller  40  determines whether or not the temperature of the wash water is greater than the first predetermined temperature. If the temperature of the wash water is greater than the first predetermined temperature, since the opening of the door  5  is unsuitable, the controller  40  returns to operation  103  and maintains the locked state of the door  5 , while continuing to monitor the temperature of the wash water. On the other hand, once the temperature of the wash water is not greater than the first predetermined temperature, since the wash water does not pose any danger to the user, the controller  40  unlocks the door in operation  111 .  
      Thereafter, in operation  113 , the controller  40  determines whether or not the washing of the tableware using the heated wash water is terminated. If the washing of the tableware is not terminated, the controller  40  returns to operation  107  to complete the washing of the tableware using the heated wash water. On the other hand, once the washing of the tableware is terminated, the controller  40  stops the operation of the circulating motor  8  in operation  115 .  
      After the washing of the tableware is terminated in operation  117 , the controller  40  operates the second heater  25  and the blowing fan  23  to circulate hot air in the washing compartment  4 . The hot air heated by the second heater  25  is forcibly blown to the air-blowing fan  23 , and the circulation of the hot air rapidly dries water on the tableware. After beginning operation of the second heater  25  and the blowing fan  23 , the controller  40  operates the door locking unit  30  to lock the door  5  in operation  119 .  
      In operation  121 , the second temperature sensor  26  senses the temperature of the hot air, and supplies a signal communicating the sensed temperature to the controller  40 . The controller  40  receives the signal, and recognizes the signal, denoting the temperature of the hot air, as the temperature in the washing compartment  4 . In operation  123 , the controller  40  compares the temperature of the washing compartment  4  to a second predetermined temperature. That is, the controller  40  determines whether or not the temperature of the washing compartment  4  is greater than the second predetermined temperature. If the temperature of the washing compartment  4  is greater than the second predetermined temperature, since the opening of the door  5  is unsuitable, the controller  40  returns to operation  119  and maintains the locked state of the door  5  while continuing to monitor the temperature of the washing compartment  4 . Once the temperature of the washing compartment  4  is not greater than the second designated temperature, since the hot air in the washing compartment  4  does not pose any danger to the user, the controller  40  unlocks the door in operation  125 .  
      As is apparent from the above description, in accordance with embodiments of the present invention, the locking of a door is controlled according to the temperature of wash water in a washing mode of a dishwashing machine, and is controlled according to the temperature in a washing compartment in a drying mode of the dishwashing machine. Accordingly, the dishwashing machine of the present invention allows the door to be opened only in a proper state, thereby being conveniently and safely used by consumers and improving reliability of dishwashing machine products.  
      Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.