BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a drying machine, and more particularly, to a drying machine with a moisture sensor for sensing the level of moisture in vapor passing through the drum of the drying machine. 
   2. Description of the Related Art 
   Modern washing machines are able to automatically perform an entire washing course, where a one-time setting of controls sets automated wash, rinse, and spin cycles. 
   Additionally, washing machines, with an added function for drying laundry that has been washed, are now being manufactured, which can also be used as a dedicated dryer to dry laundry that has already been washed. 
   A drum dryer is a home appliance that dries laundry by circulating hot, dry air within a drying drum to dry laundry inserted therein. 
   In detail, drum dryers are divided into condenser dryers that circulate air between the drying drum and a heater to dry laundry inside the drum, and vented dryers that direct from the outside into the dryer, whereupon it is heated by a heater and directed into the drying drum to dry laundry, after which the air is exhausted from the drying drum to the outside. 
   In a vented dryer, indoor air flows into the dryer, past the heater and the drum, and through a lint filter which removes it of lint. The air that passes through the lint filter then flows through an exhaust assembly formed at the bottom of the dryer, to be exhausted to the outside. 
   The air that is heated by the heater to become hot, dry air enters the drying drum and absorbs moisture from laundry therein. The air that has absorbed the moisture within the laundry drum is exhausted from the drum in the state of hot, moist vapor. 
   Here, the drying cycle is continuously performed until the moisture level of the vapor leaving the drying drum falls below a preset value, whereupon the drying cycle is completed. Therefore, it is necessary to install a sensor that can measure the moisture level of vapor passing through the drying drum at a predetermined interval. 
   SUMMARY OF THE INVENTION 
   Accordingly, the present invention is directed to a drying machine that substantially obviates one or more problems due to limitations and disadvantages of the related art. 
   An object of the present invention is to provide a drying machine with an installed moisture sensor that can accurately measure the moisture level of vapor passing through the drum. 
   Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
   To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a drying machine including: a base lower unit forming a passage within; a base upper unit mounted on a top of the base lower unit for covering the passage; a moisture sensor mounting portion formed on a top of the base upper unit; and a moisture sensor mounted on the moisture sensor mounting portion, for sensing a moisture level of air flowing through the passage. 
   In another aspect of the present invention, there is provided a drying machine of the type having a drum within for drying laundry, the drying machine including: a base forming a passage for water vapor exiting the drum; a moisture sensor formed on a side of the passage, for measuring a moisture level of the water vapor; and a microcomputer for reading the moisture level of the water vapor measured by the moisture sensor and determining whether to stop a drying cycle based on the reading. 
   In yet another aspect of the present invention, there is provided a drying machine including: a drum; a base forming a passage for air exiting the drum, the passage including a main passage intersecting with a sub passage; and a moisture sensor formed on an upper portion of the main passage or the sub passage, for measuring a moisture level of the air. 
   The above drying machine can quickly stop a drying cycle by accurately measuring the change in moisture level in air that changes to a hot, moist state as it passes through the drum. 
   It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 


   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings: 
       FIG. 1  is an exploded perspective view of a drying machine according to the present invention; 
       FIG. 2  is a perspective view of a base installed in a drying machine according to the present invention; 
       FIG. 3  is a perspective view of a base lower unit according to the present invention; 
       FIG. 4  is a perspective view of a base upper unit according to the present invention; 
       FIG. 5  is a plan view of the bottom of the base upper unit in  FIG. 4 ; 
       FIG. 6  is a perspective view showing airflow within a base according to the present invention; 
       FIG. 7  is an enlarged perspective view showing a mounting portion for a moisture sensor formed on a base upper unit according to an embodiment of the present invention; and 
       FIG. 8  is an enlarged perspective view showing an installed moisture sensor according to an embodiment of the present invention. 
   


   DETAILED DESCRIPTION OF THE INVENTION 
   Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     FIG. 1  is an exploded perspective view of a drying machine according to the present invention. 
   Referring to  FIG. 1 , a drying machine  10  according to the present invention includes a drum  14  for putting laundry into, a cabinet  11  installed outside the drum  14  for protecting the drum  14 , a base  20  installed below the drum  14  and having an air exhaust duct formed within, and a motor  15  mounted on the upper portion of the base  20  for rotating the drum  14 . 
   Also included are, a blower  18  connected to the drive shaft of the motor  15  for suctioning indoor air, and a blower cover  23  for protecting the blower  18 . 
   In more detail, the cabinet  11  includes a front cover  111  for supporting the front portion of the drum  14 , a side cover  112  installed on the side of the drum  14 , a top cover  113  provided at a top of the drum  14 , and a back cover  114  supporting the rear of the drum  14 . 
   The drying machine  10  also includes a door  12  pivotally installed at the front of the front cover  111  to open and close the opening at the front of the drum  14  for inserting and extracting laundry, a control panel  13  installed above the door  12  and having buttons for inputting washing/drying settings and operation, a drying duct  17  installed at the rear of the back cover  114  to guide outside air into the drying drum, and a heater  16  installed inside the drying duct  17  to heat the outside air drawn in. 
   The operation of the above-described drying machine  10  will now be explained. 
   First, a user opens the door  12  and inserts laundry into the drum  14 . Then, using the setting portion on the control panel  13 , the user inputs washing/drying settings. When the start button is pressed, the motor  15  and the heater  16  installed inside the drying duct  17  operate. A suctioning blower installed below the base  20  rotates to suction outside air into the drying machine  10 . 
   In more detail, outside air enters the drying duct  17  through an outside air intake port (described later) formed at the bottom of the back cover  114 , and is heated while passing through the drying duct  17 . The heated air enters the drum  14  through a rear wall of the drum  14 . The heated air that enters the drum  14  absorbs moisture imbued in laundry and becomes water vapor. The air that becomes hot and moist leaves the drum  14  by passing through a lint filter (not shown) formed on the front cover  111 , shedding impurities such as lint in the process. 
   The air that passes through the lint filter flows along the exhaust passage (described below) installed on the base  20 , and is ultimately exhausted out from the drying machine  10 . Here, the base  20  forms a passage within for air to be exhausted, and exhaust ports are formed on the sides and rear of the base  20 . One of the exhaust ports may be open while the remaining ports may be sealed. The air passage formed within the base  20  will be described in further detail below with reference to the diagrams. 
     FIG. 2  is a perspective view of a base installed in a drying machine according to the present invention. 
   Referring to  FIG. 2 , the base  20  of the drying machine according to the present invention includes a base lower portion  21  and a base upper portion  22  mounted on top of the base lower portion  21 . 
   In detail, the motor  15  is mounted on top of the base lower portion  21 , and the passage for exhausting air is formed within the upper part of the base lower portion  21 . The base upper portion  22  covers the air passage, so that the exhausting air is not dispelled but directed to flow in a predetermined direction. 
   In further detail, the base lower portion  21  and the base upper portion  22  are respectively plastic injection molded and coupled together in one piece by means of fasteners. However, the manufacturing method of the base  20  is not limited thereto, and may include being formed in a single piece. A drum connecting passage  203  is formed at the front upper portion of the base  20 , and a side exhaust port  201  is formed at the side and a rear exhaust port  202  is formed at the rear of the base  20 . The motor  15  is mounted to one side on top of the base  20 , and a blower is connected to the rotating motor shaft to suction air from inside the drum. The blower  18  is protected by a blower cover  23 . Here, the blower is installed at the front of the motor  15 , as shown in  FIG. 1 . Moreover, a suctioning blower (installed at the rear of the base  20  and not depicted in  FIG. 2 ) is attached to and operates by means of a separate motor. 
   In the above-described structure, the hot, moist discharged from the front of the drum  14  enters the drum connecting passage  203  and is exhausted back to the outside through the side exhaust port  201  and/or the rear exhaust port  202 . Below, a detailed description of the air passages formed within the base  20  will be given, with reference to the diagrams. 
     FIG. 3  is a perspective view of a base lower portion according to the present invention. 
   Referring to  FIG. 3 , the base  20  according to the present invention, as described above, includes a base lower portion  21  and a base upper portion  22  mounted on top of the base lower portion  21 . 
   In detail, an air passage, through which air is exhausted from the drum  14 , is formed in the base lower portion  21 . A complete air passage is formed by covering the bottom half of the air passage with the base upper portion  22 . 
   In more detail, a drum air descending passage  205 , for the air passing from the drum  14  to descend, is formed at the front of the base lower portion  21 . A blower entrance  206  is formed on one side of the drum air descending passage  205  for the descending air to be suctioned toward the blower. A blower compartment  211  is formed for mounting the blower at the blower entrance  206 . An expanded passage portion  212  that bends at a predetermined angle and expands in diameter is connected to an end of the blower compartment  211 . A main passage  213  that extends to the rear end of the base lower unit  21  is connected at the end of the expanded passage portion  212 . 
   A sub passage  214  is formed to intersect with the main passage  213 , forming the side exhaust ports  201  at either side of the base lower portion  21 . A condensation pan  214   a  is respectively formed a predetermined depth into the floors at the rear exhaust port  202  and side exhaust ports  201 , to collect condensing moisture from the exhausting air. A passage intersection  215  of the main passage  213  and the sub passage  214  is biased toward the rear of the base lower portion  21  from its center. That is, the sub passage  214  is closer to the rear of the base lower portion  21  than its front. 
   At least one base upper portion guiding protrusion  217  is formed on the top surface of the base lower portion  21 , in order to guide the mounting position of the base upper portion  22  over the base lower portion  21 . A fastening hook  219  is formed to protrude a predetermined height from along the perimeters of the main and sub passages  213  and  214 , in order to tightly couple the base upper portion  22  to the base lower portion  21 . Also, a plurality of fastening holes  216  are formed in the upper surface of the base lower portion  21 , so that a fastening member (for fastening the base upper portion  22 ) can insert through the fastening hole  216 . Specifically, the fastening holes  216  are formed symmetrically at the edges on either sides of the sub and main passages  214  and  213 . 
   An outside air intake port  204  is formed at the rear of the base lower portion  21 , to allow outside air to pass through the drying duct  17  into the drying drum. A suctioning blower is installed outside of the outside air intake port  204  in order to suction outside air. Here, the outside air suctioned through the outside air intake port  204  is air within the cabinet  11  of the drying machine  10 . A lint entry preventing slot  207  recessed at a predetermined depth is formed at the front of the outside air intake port  204  for trapping lint and other impurities contained in outside air suctioned through the outside air intake port  204 . 
   In more detail, a small amount of the water vapor that may leak through small gaps between the coupling portions of the base upper portion  22  and the base lower portion  21  may mix with the outside air suctioned through the outside air intake port  204 . Also, lint particles may be contained in the air from the drum  14  that passes through the passages. Despite this, the impurities contained within the outside air suctioned through the outside air intake port  204  will be caught in the lint entry preventing slot  207 , thereby reducing the amount of impurities that enters the drying duct  17 . 
   A lint entry preventing ledge  218  is formed to protrude a predetermined height from around the perimeter of the lint entry preventing slot  207 . That is, by forming the lint entry preventing ledge  218 , impurities that leak through gaps between the coupling regions of the base upper portion  22  and the base lower portion  21  are blocked in a first stage. The air filtered in a first stage by the lint entry preventing ledge  218  is filtered once more in the lint entry preventing slot  207 . 
   A motor mount  215   a  for mounting the motor  15  is formed in the space between the blower compartment  211  and the sub passage  214 , where a motor supporting insert slot  215   b  is formed for supporting a motor supporter (not shown). 
   In the above structure, the water vapor that descends through the drum air descending passage  205  flows through the blower entrance  206  into the blower compartment  211 . The air that enters the blower compartment  211  flows through the expanded passage portion  212  to the main passage  213 . The air that flows to the main passage  213  branches at the passage intersection  215  and flows through at least one of the side exhaust ports  201  and/or the rear exhaust port  202  to the outside. 
   Here, a portion of the two side exhaust ports  201  and the rear exhaust port  202  may be sealed with caps. For example, if the drying machine  10  is installed in a corner, one of the side exhaust ports  201  and the rear exhaust port  202  may sealed with caps, with only the remaining side exhaust port  201  opened. That is to say that caps can be used to selectively seal the exhaust ports, as mandated by the installed location of the drying machine  10 . 
   The air that flows toward the sealed exhaust ports during the circulation through the passages condenses, and the condensed water accumulates in the condensation pans  214   a.  Also, even when all the exhaust ports  201  and  202  are open, air that flows through the passages condenses, whereupon the condensed water accumulates in the condensation pans  214   a.    
     FIG. 4  is a perspective view of a base upper portion according to the present invention, and  FIG. 5  is a plan view of the bottom of the base upper portion in  FIG. 4 . 
   Referring to  FIGS. 4 and 5 , the base upper portion  22  according to the present invention, as described above, is mounted on top of the base lower portion  21 . 
   Specifically, the base upper portion  22  is formed in a shape corresponding to that of the base lower portion  21  in terms of the passages, in order to seal the upper portion of the passages. A drum connecting passage  203  is formed at the front of the base upper portion  22 , to provide an entrance for water vapor air exiting the drum  14  toward the passages. 
   In more detail, the drum connecting passage  203  extends a predetermined distance upward from the top of the base upper portion  22  to form the interior of a drum connecting duct  221 . A blower connecting portion  221   a  is formed to extend from the side of the drum connecting duct  221 , so that air passes through the drum connecting passage  203  and flows into the blower entrance  206  formed in the base lower portion  21 . 
   A main passage cover  222  and a sub passage cover  223  are formed on the base upper portion  22  to cover the expanded passage portion  212 , the main passage  213 , and the sub passage  214  formed in the base lower portion  21 . The main passage cover  222  and the sub passage cover  223  also intersect with each other. A humidity sensor mount  300  is formed in a portion of the main passage cover  222  for installing a humidity sensor therein, in order to detect the level of humidity of air flowing through the main passage  213 . 
   A fringe  228  is formed to protrude a predetermined distance from the lower portions of the main passage cover  222  and the sub passage cover  223 , and hook insert holes  225  in the fringe  228 . Also, fastening hooks  219  are formed a predetermined distance apart from one another on the upper perimeters of the main passage  213  and the sub passage  214  of the base lower portion  21 . The fastening hooks  219  insert into the hook insert holes  225 . 
   The fastening tab  224  is formed to protrude further from the fringe  228  to fasten the base upper portion  22  to the base lower portion  21  more firmly. Specifically, a fastening hole  224   a  is formed in each fastening tab  224 , so that a fastening member inserted through the fastening hole  224   a  inserts into the fastening hole  216  formed in the base lower portion  21 . That is, the fastening member tightens the coupling of the base upper portion  22  to the base lower portion  21 , so that no gaps are formed between the base upper and lower portions  22  and  21 . In this way, the size of gaps formed between the base upper and lower portions  22  and  21  may be minimized, preventing leakage of air flowing within the passages and the possibility of it re-entering through the outside air intake port  204 . In other words, the air flowing through the inside of the passages is prevented from leaking into the interior space of the cabinet  11  holding the drum  14  and being suctioned into the outside air intake port  204 . 
   In the above structure, the water vapor that exits the drum  14  passes through the drum connecting passage  203  and descends to the drum air descending passage  205 . The air that descends to the drum air descending passage  205  flows to the blower entrance  206 . The air that descends to the drum connecting passage  203  flows along the blower connecting portion  221   a  and into the blower entrance  206 . The air that enters the blower entrance  206  moves through the expanded passage portion  212 , the main passage  213 , and the sub passages  214 . The air that flows through the main and sub passages  213  and  214  condenses and is exhausted to the outside through the rear exhaust port  202  and/or the side exhaust port(s)  201 . 
     FIG. 6  is a perspective view showing airflow within a base according to the present invention. 
   Referring to  FIG. 6 , as described above, the air that passes through the drum  14  passes through the lint filter installed in the front cover  111  to shed impurities in a first stage, and then descends through the drum connecting passage  203 . Then, the air that descends through the drum connecting passage  203  moves to the blower entrance  206  formed at the end of the blower connecting portion  221   a.    
   The air that moves to the blower entrance  206  is redirected by the blower installed in the blower compartment  211 . The air that is redirected by the blower flows to the expanded passage portion  212 . The flow direction of the air is redirected again at the expanded passage portion  212  to the main passage  213 , and the air flows to the rear of the base  20 . A portion of the air flowing through the main passage  213  branches off at the passage intersection  215  (where the main and sub passages  213  and  214  intersect) to the sub passages  214 . The air flowing through the main and sub passages  213  and  214  flow through the rear exhaust port  202  and/or side exhaust port(s)  201  to be exhausted back to the outside. Here, the water vapor that exits the drum  14  cools (and a portion of the moisture in the air condenses) during the time it takes to flow from the drum connecting passage  203  to the exhaust ports  201  and  202 . The condensed moisture accumulates in the condensation pans  214   a  recessed in the floors of the main and sub passages  213  and  214 . 
   The outside air that flows into the rear of drum  14 , that is, outside air with the same temperature and humidity of inside air, re-enters the drum  14  through the drying duct  17  through the outside air intake port  204  formed at the rear of the base  20 . 
     FIG. 7  is an enlarged perspective view showing a mounting portion for a moisture sensor formed on a base upper unit according to an embodiment of the present invention, and  FIG. 8  is an enlarged perspective view showing an installed moisture sensor according to an embodiment of the present invention. 
   Referring to  FIGS. 7 and 8 , fastening holes  320  are formed a predetermined distance apart on an outer or inner perimeter of a moisture sensor mounting portion  300 , in order to fasten a moisture sensor  400  on the upper surface of the base upper unit  22  by inserting predetermined fastening members in the fastening holes  320 . 
   A fastening protrusion  310 , for guiding the moisture sensor  400  to align a fastening holes  402  formed on the moisture sensor  400  with the fastening holes  320  formed on the outer perimeter of the moisture sensor mounting portion  300  during the process of coupling the moisture sensor  400  to the base upper unit  22 , is formed on the outer perimeter of the moisture sensor mounting portion  300 . 
   A fastening tab  401 , having the fastening hole  402  formed therethrough, is formed to extend a predetermined length from the outer perimeter of the moisture sensor  400 . 
   A connector  410  is connected to ends of cables for receiving moisture level values sensed by the moisture sensor  400  in the form of electrical signals. 
   In further detail, the connector  410  is a means for connecting cables extending from the micom (microcomputer) of the drying machine to the cables extending to the moisture sensor  400 . Therefore, when the moisture sensor  400  needs to be serviced or replaced, only the cables connected at the connector  410  need to be disassembled. 
   Also, in order to prevent the moisture sensor  400  and the connector  410  from being shaken during transporting of the drying machine  10 , the moisture sensor  400  and the connector  410  are respectively fixed by the moisture sensor mounting portion  300  and a connector supporting brace  330 . 
   In further detail, in order to install the moisture sensor  400  on the base upper unit  22 , fastening protrusions  310  formed on the outer perimeter of the moisture sensor mounting portion  300  insert into a portion of the fastening holes  402 . 
   Screws or other fastening members are inserted through the remaining fastening holes  402  that do not have the fastening protrusions  310  inserted therein, to insert in the fastening holes  320  formed on the outer perimeter of the moisture sensor mounting portion  300 . 
   Additionally, the connector  410  is mounted within the connector supporting brace  330 , so that the connector  410  is unaffected by vibrations or shaking generated by the drying machine  10 . 
   Because the connector  410  is a connecting member for cable-to-cable connecting, it is essential that the connector supporting brace  330  be impervious to juddering caused by external vibrations. The cables connecting the connector  410  with the micom are mounted between the two parts of the connector supporting brace  330  and extend along the upper surface of the sub passage cover  223  of the base upper unit  22 . 
   It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
A drying machine having a drum mounted within a cabinet on a base unit is provided. The base unit includes a base lower unit, and a base upper unit positioned atop the base lower unit to define passages therebetween. The base unit includes a moisture sensor mounting portion that receives a moisture sensor on a top of the base upper unit. The moisture sensor senses a moisture level of air flowing through the passages.