Abstract:
An additive-storing tank assembly includes: a tank body having an additive-storing space defined in the tank body, in which an additive is stored; a plunger-holding tube provided at one side of the tank body in order to connect the additive-storing space with a water supply pipe for supplying water to a dispenser of a refrigerator; and an opening/closing means for selectively connecting the additive-storing space with the water supply pipe so that the additive stored in the additive-storing space is dissolved in the water flowing through the water supply pipe.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the invention 
     The present invention relates to a refrigerator, and more particularly to an additive-storing tank assembly for putting an additive, such as carbonic acid gas, into water dispensed from a dispenser and a refrigerator having the same. 
     2. Description of the Prior Art 
       FIG. 1  illustrates an internal structure of a conventional refrigerator. 
     As shown, the conventional refrigerator has a storage space defined in a refrigerator body  1 , which is partitioned into a freezer compartment and a fresh food compartment disposed at left and right sides, respectively. The freezer compartment and the fresh food compartment are selectively opened and closed by a freezer compartment door  3  and a fresh food compartment door  5 , respectively. 
     A filter  7  is mounted inside of the refrigerator body  1 . The filter  7  filters water supplied through a first water supply pipe p 1  from an external water source (WS). The first water supply pipe p 1  is equipped with a first valve v 1  for regulating the quantity of the water supplied to the filter  7  from the water source. 
     A water tank  9  is installed in the fresh food compartment. The water tank  9  stores the water supplied through a second water supply pipe p 2  after being filtered by the filter  7 . The water stored in the water tank  9  is maintained at a low temperature by the cool air in the fresh food compartment. The second water supply pipe p 2  is equipped with a second valve v 2  for regulating the quantity of the water supplied to the water tank  9  after being filtered by the filter  7 . 
     The cool water stored in the water tank  9  is transferred through a third water supply pipe p 3  to a dispenser  11  disposed at the front surface of the freezer compartment door  3 . Further, according to the operation of the dispenser  11 , the cool water stored in the water tank  9  is transferred through the third water supply pipe p 3  to the dispenser  11  and is then dispensed out of the dispenser  11 . 
     In the meantime, the freezer compartment is equipped with an ice maker  13  which produces ice by using the water supplied through a fourth water supply pipe p 4  after being filtered by the filter  7  and then supplies the produced ice to the dispenser  11 . The fourth water supply pipe p 4  is branched from a portion of the first water supply pipe p 1  between the filter  7  and the water tank  9 . The fourth water supply pipe p 4  is equipped with a third valve v 3  for regulating the quantity of the water supplied to the ice maker  13  after being filtered by the filter  7 . 
     However, the conventional refrigerator having the above-mentioned structure has the following problems. 
     In the conventional refrigerator as described above, the water from the water source is simply dispensed out through the dispenser  11  after being filtered by the filter  7  and then cooled in the water tank  9 . However, the conventional refrigerator cannot provide water having various savors and flavors according to users&#39; tastes. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide an additive-storing tank assembly and a refrigerator having the same, which can dispense water with various added flavors and fragrance through a dispenser. 
     In order to accomplish this object, there is provided an additive-storing tank assembly comprising: a tank body having an additive-storing space defined in the tank body, in which an additive is stored; a plunger-holding tube provided at one side of the tank body in order to connect the additive-storing space with a water supply pipe for supplying water to a dispenser of a refrigerator; and an opening/closing means for selectively connecting the additive-storing space with the water supply pipe so that the additive stored in the additive-storing space is dissolved in the water flowing through the water supply pipe. 
     Preferably, the additive-storing tank assembly may further comprise a mounting bracket having a shape of a hollow cylinder having one open end, which is provided at and connected to the water supply pipe, wherein the plunger-holding tube has a shape of a hollow cylinder which has an outer diameter and a length corresponding to an inner diameter and a length of the mounting bracket, both ends of the plunger-holding tube are open, and the plunger-holding tube is inserted in the mounting bracket, so that the additive stored in the additive-storing space is dissolved in the water when the water flowing through the water supply pipe passes through the plunger-holding tube, and the dissolved additive-containing water is then transferred to the dispenser. 
     The mounting bracket may have an inlet port for introducing the water from the water supply pipe and an outlet port for discharging the water to the water supply pipe, and the plunger-holding tube has an inlet port and an outlet port connected with the inlet port and the outlet port of the mounting bracket, respectively. 
     Preferably, the opening/closing means may comprise a plunger having a shape of a cylinder having an outer diameter corresponding to an inner diameter of the plunger-holding tube, the plunger being longer than the plunger-holding tube, the plunger being inserted in the plunger-holding tube in such a manner that the plunger is movable in a longitudinal direction in the plunger-holding tube, the plunger having a fluid channel formed in the plunger, the fluid channel connecting the additive-storing space with the inlet port and the outlet port of the plunger-holding tube only when the plunger is located at a predetermined position in the plunger-holding tube; and an elastic member for applying elastic force to the plunger so as to move the plunger toward a position at which the fluid channel is not connected with the inlet port and the outlet port of the plunger-holding tube and the plunger blocks the additive-storing space from the inlet port and the outlet port of the plunger-holding tube, wherein, when the plunger-holding tube is inserted in the mounting bracket, the plunger is pushed against the elastic force of the elastic member by a portion of the mounting bracket, so that the additive-storing space is connected with the inlet port and the outlet port of the plunger-holding tube through the fluid channel. 
     Preferably, a spring seat for seating the elastic member is formed on an inner cylindrical surface of the plunger-holding tube; a guide rib is provided on a portion of an outer cylindrical surface of the plunger, so that the guide rib moves within the spring seat when the plunger moves in a longitudinal direction of the plunger-holding tube; and the elastic member includes a coil spring having both ends held by one end of the spring seat and one side of the guide rib. 
     The additive-storing tank assembly may further comprise a locking means for preventing the plunger-holding tube from being unintentionally separated after being assembled with the mounting bracket. 
     Preferably, the locking means may comprise a locking flange extending radially outward from the open end of the mounting bracket and having a plurality of locking hooks formed at a rim of the locking flange, the locking hooks being spaced apart a predetermined interval along the rim of the locking flange; and a locking plate extending radially outward from a portion of an outer cylindrical surface of the plunger-holding tube and having a plurality of locking holes corresponding to the locking hooks, wherein, when the locking plate is inserted into the locking flange by passing the locking hooks the locking holes and is then rotated a predetermined angle, the locking hooks are engaged with the locking plate, so as to prevent the plunger-holding tube from being unintentionally separated from the mounting bracket. 
     The additive-storing tank assembly may further comprise a sealing means for sealing clearance between the mounting bracket and the plunger-holding tube. 
     Preferably, the sealing means comprises a sealing ring inserted in sealing grooves formed on the mounting bracket and the plunger-holding tube, which are opposed to each other. 
     More preferably, the additive stored in the additive-storing space includes carbonic acid gas. 
     According to another aspect of the present invention, there is a filter for filtering water supplied through a first water supply pipe from an external water source; a water tank for storing and cooling the water supplied through a second water supply pipe after being filtered by the filter; and an additive-storing tank assembly assembled with a third water supply pipe for supplying the water from the water tank to a dispenser so that additive stored in the additive-storing tank assembly is dissolved in the water flowing through the third water supply pipe. 
     The refrigerator may further comprise an ice maker for supplying ice to the dispenser after producing the ice by using the water supplied through a fourth water supply pipe after being filtered by the filter, the fourth water supply pipe being branched off from the second water supply pipe. 
     According to a further aspect of the present invention, there is a first water supply pipe through which water supplied from an external water source flows; a filter for filtering the water supplied through the first water supply pipe; a second water supply pipe through which the water filtered by the filter flows; a water tank for storing and cooling the water supplied through second water supply pipe after being filtered by the filter; a third water supply pipe through which the water from the water tank flows; an additive-storing tank assembly for storing additive which will be dissolved in the water flowing through the third water supply pipe from the water tank; a dispenser for storing and dispensing the additive-containing water supplied through the third water supply pipe; a fourth water supply pipe through which the water flows after being filtered by the filter, the fourth water supply pipe being branched off from the second water supply pipe; and an ice maker from supplying ice to the dispenser after producing the ice by using water supplied through the fourth water supply pipe, which a part of the water filtered by the filter. 
     Preferably, the first water supply pipe is equipped with a first valve for regulating a quantity of the water supplied to the filter from the water source. 
     Preferably, the third water supply pipe is equipped with a second valve for regulating a quantity of the water supplied to the dispenser, in which the additive is dissolved. 
     More preferably, the fourth water supply pipe is provided with a third valve for regulating a quantity of the water supplied to the ice maker after being filtered by the filter. 
     The additive-storing tank assembly may be assembled with a portion of the third water supply pipe adjacent to the water tank. 
     The additive-storing tank assembly may comprise a tank body having an additive-storing space defined in the tank body, in which an additive is stored; a plunger-holding tube provided at one side of the tank body in order to connect the additive-storing space with the third water supply; and an opening/closing means for selectively connecting the additive-storing space with the third water supply pipe so that the additive stored in the additive-storing space is dissolved in the water flowing through the third water supply pipe. 
     The refrigerator may further comprise a mounting bracket having a shape of a hollow cylinder having one open end, which is provided at and connected to the third water supply pipe, wherein the plunger-holding tube has a shape of a hollow cylinder which has an outer diameter and a length corresponding to an inner diameter and a length of the mounting bracket, both ends of the plunger-holding tube are open, and the plunger-holding tube is inserted in the mounting bracket, so that the additive stored in the additive-storing space is dissolved in the water when the water flowing through the third water supply pipe passes through the plunger-holding tube, and the dissolved additive-containing water is then transferred to the dispenser. 
     Preferably, the mounting bracket has an inlet port for introducing the water from the third water supply pipe and an outlet port for discharging the water to the third water supply pipe, and the plunger-holding tube has an inlet port and an outlet port connected with the inlet port and the outlet port of the mounting bracket, respectively. 
     The opening/closing means may comprise a plunger having a shape of a cylinder having an outer diameter corresponding to an inner diameter of the plunger-holding tube, the plunger being longer than the plunger-holding tube, the plunger being inserted in the plunger-holding tube in such a manner that the plunger is movable in a longitudinal direction in the plunger-holding tube, the plunger having a fluid channel formed in the plunger, the fluid channel connecting the additive-storing space with the inlet port and the outlet port of the plunger-holding tube only when the plunger is located at a predetermined position in the plunger-holding tube; and an elastic member for applying elastic force to the plunger so as to move the plunger toward a position at which the fluid channel is not connected with the inlet port and the outlet port of the plunger-holding tube and the plunger blocks the additive-storing space from the inlet port and the outlet port of the plunger-holding tube, wherein, when the plunger-holding tube is inserted in the mounting bracket, the plunger is pushed against the elastic force of the elastic member by a portion of the mounting bracket, so that the additive-storing space is connected with the inlet port and the outlet port of the plunger-holding tube through the fluid channel. a spring seat for seating the elastic member is formed on an inner cylindrical surface of the plunger-holding tube; 
     Preferably, a guide rib is provided on a portion of an outer cylindrical surface of the plunger, so that the guide rib moves within the spring seat when the plunger moves in a longitudinal direction of the plunger-holding tube; and the elastic member includes a coil spring having both ends held by one end of the spring seat and one side of the guide rib. 
     The refrigerator may further comprise a locking means for preventing the plunger-holding tube from being unintentionally separated after being assembled with the mounting bracket. 
     The locking means may comprise a locking flange extending radially outward from the open end of the mounting bracket and having a plurality of locking hooks formed at a rim of the locking flange, the locking hooks being spaced apart a predetermined interval along the rim of the locking flange; and a locking plate extending radially outward from a portion of an outer cylindrical surface of the plunger-holding tube and having a plurality of locking holes corresponding to the locking hooks, wherein, when the locking plate is inserted into the locking flange by passing the locking hooks the locking holes and is then rotated a predetermined angle, the locking hooks are engaged with the locking plate, so as to prevent the plunger-holding tube from being unintentionally separated from the mounting bracket. 
     Preferably, the refrigerator may further comprise a sealing means for sealing clearance between the mounting bracket and the plunger-holding tube. 
     The sealing means may comprise a sealing ring inserted in sealing grooves formed on the mounting bracket and the plunger-holding tube, which are opposed to each other. 
     Preferably, the additive stored in the additive-storing space may include carbonic acid gas. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a front view of a conventional refrigerator, which illustrates an internal structure thereof; 
         FIG. 2  is a front view of a refrigerator having an additive-storing tank assembly according to a preferred embodiment of the present invention, which illustrates an internal structure thereof; and 
         FIG. 3  is a sectional view of an additive-storing tank assembly assembled with a mounting bracket in the refrigerator shown in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, an additive-storing tank assembly and a refrigerator having the tank assembly according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. 
       FIG. 2  is a front view of a refrigerator having an additive-storing tank assembly according to an embodiment of the present invention, and  FIG. 3  is a sectional view of the additive-storing tank assembly installed in the refrigerator shown in  FIG. 2 . 
     As shown, a storage space is defined in a refrigerator body  31 . Although the storage space in the refrigerator shown in  FIG. 2  is partitioned into left and right sides for a freezer compartment and a fresh food compartment, respectively, it is possible to partition the storage space into upper and lower sides. The freezer compartment and the fresh food compartment are opened or closed by a freezer compartment door  33  and a fresh food compartment door  35 , respectively, which are rotatably assembled with the refrigerator body  31 . 
     A filter  37  is installed in the refrigerator body  31 . Water is supplied from an external water source (WS) through a first water supply pipe p 1  to the filter  37 . The filter  37  filters the water supplied from the water source. 
     The first water supply pipe p 1  is provided with a first valve v 1  for regulating the quantity of the water supplied to the filter  37  from the water source. 
     A water tank  39  is installed in the fresh food compartment. The water tank  39  stores the water supplied through a second water supply pipe p 2  after being filtered by the filter  37 . The water stored in the water tank  39  is maintained at a low temperature by the cooling air circulating in the fresh food compartment. 
     The water stored in the water tank  39  is supplied to a dispenser  41  through a third water supply pipe p 3 . The dispenser  41  is installed at a portion of the front surface of the freezer compartment door  33 . According to user&#39;s operation, the dispenser  41  dispenses the water supplied through the third water supply pipe p 3  from the water tank  39 . 
     The third water supply pipe p 3  is equipped with a second valve v 2  for regulating the quantity of the water supplied to the dispenser  41  from the filter  37 . 
     An ice maker  43  is installed in the freezer compartment. The ice maker  43  receives the water supplied through a fourth water supply pipe p 4  after being filtered by the filter  37  and produces ice from the received water. To this end, the fourth water supply pipe p 4  is branched from a portion of the second water supply pipe p 2 , specifically, a portion of the second water supply pipe p 2  between the filter  37  and the water tank  39 . 
     The fourth water supply pipe p 4  is provided with a third valve v 3  for regulating the quantity of the water supplied to the ice maker  43  after being filtered by the filter  37 . 
     Further, the third water supply pipe p 3  is equipped with a mounting bracket  50  for holding an additive-storing tank assembly  60  which will be described later in more detail. The mounting bracket  50  is installed at a portion of the third water supply pipe p 3  adjacent to the water tank  39 , in order to help the additive stored in the additive-storing tank assembly  60  to be more easily dissolved in the water flowing through the third water supply pipe p 3 . For example, let us consider carbonic acid gas as an example of the additive stored in the additive-storing tank assembly  60 . The cooler the solution in which the carbonic acid gas is dissolved, the higher the solubility of the carbonic acid gas. Therefore, the mounting bracket  50  is installed to a portion of the third water supply pipe p 3  adjacent to the water tank  39  in which relatively cooler water flows, so that the additive stored in the additive-storing tank assembly  60  can be more effectively dissolved in the water supplied to the dispenser  41 . 
     Referring to  FIG. 3 , the mounting bracket  50  has a shape of a hollow cylinder having one open end. The mounting bracket  50  has an inlet port  51   i  and an outlet port  51   o  formed through a cylindrical wall of the mounting bracket  50 . The water flowing through the third water supply pipe p 3  is introduced into the mounting bracket  50  through the inlet port  51   i  and then discharged out of the mounting bracket  50  through the outlet port  51   o.    
     A locking flange  53  is formed at the open end of the mounting bracket  50 . The locking flange  53  extends radially outward from the open end of the mounting bracket  50 . The locking flange  53  has a plurality of locking hooks  55  formed at a rim of the locking flange  53 . The locking hooks  55  are spaced apart a predetermined interval along the rim of the locking flange  53 . 
     Further, a spring seat  69  is formed on a portion of an inner cylindrical surface of the mounting bracket  50 . A sealing groove  57  of the mounting bracket  50  has a semi-circular sectional shape and is formed in a circle transversely along the inner cylindrical surface of the mounting bracket  50 . A sealing ring  77 , which will be described later in more detail, is inserted in the sealing groove  57  of the mounting bracket  50 . 
     The additive-storing tank assembly  60  is installed in the mounting bracket  50 . The additive-storing tank assembly  60  contains additive which will be dissolved in the water which flows through the third water supply pipe p 3 , that is, the cool water stored in the water tank  39 . As shown in  FIG. 3 , the additive-storing tank assembly  60  includes a tank body  61 , a plunger-holding tube  63 , and a plunger  71 . 
     The tank body  61  has an additive-storing space  62  defined in the tank body  61 , in which the additive is stored. The additive-storing space  62  may store various additives according to users&#39; tastes, including carbonic acid gas. Further, the additive stored in the additive-storing space  62  is dissolved in the water flowing through the third water supply pipe p 3 . 
     The plunger-holding tube  63  has a shape of a hollow cylinder which has an outer diameter corresponding to the inner diameter of the mounting bracket  50 . The plunger-holding tube  63  has a length corresponding to the length of the mounting bracket  50 , and both ends of the plunger-holding tube  63  are open. The plunger-holding tube  63  is disposed at one side of the tank body  61 , and the hollow space inside of the plunger-holding tube  63  communicates with the additive-storing space  62 . The plunger-holding tube  63  is inserted in the mounting bracket  50 . 
     The plunger-holding tube  63  has an inlet port  63   i  and an outlet port  63   o . The inlet port  63   i  and the outlet port  63   o  of the plunger-holding tube  63  are formed at locations corresponding to the inlet port  51   i  and the outlet port  51   o  of the mounting bracket  50 , respectively. The water flowing through the third water supply pipe p 3  is introduced through the inlet port  51   i  of the mounting bracket  50  and the inlet port  63   i  of the plunger-holding tube  63  into a fluid channel  73  which will be described later in more detail. While the water flows through the fluid channel  73 , the additive stored in the additive-storing space  62  is added to the water. Then, the additive-containing water is discharged through the outlet port  63   o  of the plunger-holding tube  63  and the outlet port  51   o  of the mounting bracket  50  into the third water supply pipe p 3 . 
     A locking plate  65  is provided around a portion of an outer cylindrical surface of the plunger-holding tube  63  adjacent to the tank body  61 . The locking plate  65  extends radially outward from the portion of the outer cylindrical surface of the plunger-holding tube  63 . When the plunger-holding tube  63  is inserted and fitted in the additive-storing tank assembly  60 , the locking plate  65  is inserted in the locking flange  53 . 
     The locking plate  65  has a plurality of locking holes (not shown). The locking plate  65  has as many locking holes as the locking hooks  55 , and the locking holes have shapes corresponding to the shapes of the locking hooks  55 . When the locking plate  65  is inserted into the locking flange  53 , the locking hooks  55  are inserted through the locking holes. 
     A sealing groove  67  is formed on an outer cylindrical surface of the plunger-holding tube  63 . When the plunger-holding tube  63  has been inserted and fitted in the mounting bracket  50 , the sealing groove  67  of the plunger-holding tube  63  is located at a position corresponding to the sealing groove  57  of the mounting bracket  50 . The sealing groove  67  of the plunger-holding tube  63  also has a semi-circular sectional shape and is formed in a circle transversely around the outer cylindrical surface of the plunger-holding tube  63  while being opposed to the sealing groove  57  of the mounting bracket  50 . 
     The spring seat  69  is formed on an inner cylindrical surface of the plunger-holding tube  63 . The spring seat  69  is formed by caving a portion of the inner cylindrical surface of the plunger-holding tube  63  so that the inner diameter of the spring seat  69  is larger than the inner diameter of the plunger-holding tube  63 . A coil spring  79 , which will be described later in more detail, is seated in the spring seat  69 . 
     The plunger  71  has a shape of a cylinder having an outer diameter corresponding to the inner diameter of the plunger-holding tube  63 . The plunger  71  is longer than the plunger-holding tube  63 . The plunger  71  is inserted in the plunger-holding tube  63  in such a manner that the plunger  71  is movable in a longitudinal direction in the plunger-holding tube  63 . 
     More specifically, before the plunger-holding tube  63  is fitted in the mounting bracket  50 , a portion of the plunger  71  protrudes out of one end of the plunger-holding tube  63 , which is located at the opposite side of the tank body  61 , that is, at the right end of the plunger-holding tube  63  in  FIG. 3 . While the plunger-holding tube  63  is inserted and fitted in the mounting bracket  50 , the portion of the plunger  71  is pushed leftward in  FIG. 3  by the closed end of the mounting bracket  50 . 
     The fluid channel  73  is formed in a shape of the letter “T” in the plunger  71 . The fluid channel  73  selectively interconnects the additive-storing space  62  with the inlet port  63   i  and the outlet port  63   o  of the plunger-holding tube  63 . That is, only when the plunger  71  is located at a predetermined position in the plunger-holding tube  63 , the additive-storing space  62  communicates with the inlet port  63   i  and the outlet port  63   o  of the plunger-holding tube  63  through the fluid channel  73 . At this time, the three ends of the fluid channel  73  are connected to the additive-storing space  62 , the inlet port  63   i  of the plunger-holding tube  63 , and the outlet port  63   o  of the plunger-holding tube  63 , respectively. 
     A guide rib  75  is provided on a portion of an outer cylindrical surface of the plunger  71 . The guide rib  75  protrudes radially outward from the outer cylindrical surface of the plunger  71 . When the plunger  71  is fitted in the plunger-holding tube  63 , the guide rib  75  is located within the spring seat  69 . When the plunger  71  moves in the longitudinal direction of the plunger-holding tube  63 , the guide rib  75  moves within the spring seat  69 . 
     The sealing ring  77  is inserted in and between the sealing groove  57  of the mounting bracket  50  and the sealing groove  67  of the plunger-holding tube  63 . The sealing ring  77  seals the clearance between the mounting bracket  50  and the plunger-holding tube  63 . To this end, it is preferred that the sealing ring  77  is made from a flexible material. 
     Meanwhile, the coil spring  79  is seated in the spring seat  69 . The coil spring  79  is wound around the plunger  71 . Both ends of the coil spring  79  are held by the left end of the spring seat  69  and the left surface of the guide rib  75  in  FIG. 3 , respectively. 
     The coil spring  79  applies elastic force to the plunger  71  in the rightward direction in  FIG. 3 , that is, the coil spring  79  pushes the plunger  71  rightward so that the fluid channel  73  is not aligned with the inlet port  63   i  and the outlet port  63   o  of the plunger-holding tube  63  and the plunger  71  blocks the inlet port  63   i  and the outlet port  63   o  of the plunger-holding tube  63 . Therefore, by the elastic force provided by the coil spring  79 , the fluid channel  73  is not aligned with the inlet port  63   i  and the outlet port  63   o  of the plunger-holding tube  63  and the plunger  71  blocks the inlet port  63   i  and the outlet port  63   o  of the plunger-holding tube  63 . 
     Hereinafter, the operations of an additive-storing tank assembly and a refrigerator having the tank according to the present invention will be described. 
     First, a process for assembling the additive-storing tank assembly according to the present invention with the mounting bracket will be described in detail. 
     Before the additive-storing tank assembly  60  is assembled with the mounting bracket  50 , the first valve v 1  and the second valve v 2  are locked, so as to prevent the water from flowing through the third water supply pipe p 3 , thereby preventing water leakage during the course of assembling the additive-storing tank assembly  60  with the mounting bracket  50 . 
     In order to assemble the additive-storing tank assembly  60  with the mounting bracket  50 , the plunger-holding tube  63  is inserted in the mounting bracket  50 . At this time, the locking plate  65  is inserted in the locking flange  53  by passing the locking hooks  55  through the locking holes. Then, the tank body  61  is rotated a predetermined angle, so that the locking hooks  55  are engaged with the solid portions of the locking plate  65 . Then, the plunger-holding tube  63 , or actually the additive-storing tank assembly  60 , is fixedly assembled with the mounting bracket  50  and is prevented from being unintentionally separated from the mounting bracket  50 . 
     While the plunger-holding tube  63  is inserted into the mounting bracket  50 , the plunger  71  is pushed toward the inside of the plunger-holding tube  63 , that is, leftward of  FIG. 3 , by the inner bottom of the closed end of the mounting bracket  50 . Therefore, the plunger  71  moves leftward against the elastic force of the coil spring  79  from the position at which the plunger  71  blocks the additive-storing space  62  and the inlet port  63   i  and the outlet port  63   o  of the plunger-holding tube  63 . When the plunger-holding tube  63  has been completely inserted and fitted in the mounting bracket  50 , the plunger  71  is located at a position at which the fluid channel  73  of the plunger  71  connects the additive-storing space  62  with the inlet port  63   i  and the outlet port  63   o  of the plunger-holding tube  63 . 
     When the additive-storing space  62  is connected with the inlet port  63   i  and the outlet port  63   o  of the plunger-holding tube  63 , the water flowing through the third water supply pipe p 3  is introduced into the fluid channel  73  through the inlet port  51   i  of the mounting bracket  50  and the inlet port  63   i  of the plunger-holding tube  63 . Then, the water flowing through the fluid channel  73  is discharged again to the third water supply pipe p 3  through the outlet port  63   o  of the plunger-holding tube  63  and the outlet port  51   o  of the mounting bracket  50 . At this time, additive (e.g. carbonic acid gas) stored in the additive-storing space  62  is dissolved in the water flowing through the fluid channel  73 . 
     The clearance between the mounting bracket  50  and the plunger-holding tube  63  is blocked by the sealing ring  77 . Therefore, the water introduced from the third water supply pipe p 3  or the additive stored in the additive-storing space  62  is prevented from leaking out. 
     Next, a process of dispensing water from an additive-storing tank assembly and a refrigerator having the tank according to the present invention will be described in more detail. 
     When the first valve v 1  is opened, water is supplied from the water source (WS) through the first water supply pipe p 1  to the filter  37 . The water from the water source is filtered by the filter  37 , supplied through the second water supply pipe p 2  to the water tank  39 , and then stored in the water tank  39 . The water stored in the water tank  39  is cooled and maintained at a low temperature by the cool air circulating in the fresh food compartment. 
     When a user operates the dispenser  41 , the second valve v 2  is opened, so that the water stored in the water tank  39  is supplied through the third water supply pipe p 3  to the dispenser  41  which dispenses out the water. At this time, additive supplied by the additive-storing tank assembly  60  provided at the third water supply pipe p 3  is dissolved in the water supplied to the dispenser  41 . Therefore, the user can take and enjoy the water to which various flavors and savors are added. 
     In the meantime, a part of the water filtered by the filter  37  is supplied to the ice maker  43  through the fourth water supply pipe p 4 . The ice maker  43  produces ice by using the water supplied through the fourth water supply pipe p 4 . The ice produced by the ice maker  43  is supplied to the dispenser  41  so that the dispenser  41  can dispense out the ice. 
     The water supply to the ice maker  43  can be controlled by the third valve v 3 . That is to say, when it is unnecessary to produce ice by the ice maker  43 , the third valve v 3  may be locked, so that all of the water filtered by the filter  37  can be transferred to the water tank  39 . 
     An additive-storing tank assembly and a refrigerator having the tank according to the present invention can provide the following effects. 
     According to the present invention, various additives stored in an additive-storing tank assembly are dissolved in the cool water supplied to the dispenser from the water tank. 
     Further, according to the present invention, an additive-storing tank assembly is disposed at a portion of a water supply pipe, from which water is discharged, that is, the portion through which relatively cooler water flows. Therefore, the present invention improves the solubility of the additive stored in the additive-storing tank assembly and enables the additive to be more effectively dissolved in the water. 
     Although a preferred embodiment of the present invention has been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.