Patent Publication Number: US-6214282-B1

Title: Simultaneous filling blow molding method and apparatus

Description:
This application is a Division of application Ser. No. 08/803,752, filed Feb. 21, 1997, now U.S. Pat. No. 5,962,039. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a simultaneous filling blow molding method and apparatus, and more particularly to a simultaneous filling blow molding method and apparatus which prevents pollution to a molded article arising from invasion of foreign substances and eliminates germs from the molded article. 
     2. Description of the Related Art 
     When a medicine or food is filled into a hollow article molded by a blow molding apparatus, prevention of pollution to and elimination of germs from the inside of the hollow article must be achieved. One of conventionally known blow molding methods and apparatus of the type mentioned is disclosed, for example, in Japanese Patent Publication Application No. Heisei 7-35089 and is described below with reference to FIGS. 1 to  4 . 
     As shown in FIG. 1, a parison molding nozzle  71  which opens downwardly is provided on a cross head  70  attached to an end portion of an extruder (not shown). A metallic mold  74  held on a movable frame  72  by means of a holding plate  73  is opened and closed by a driving cylinder (not shown) incorporated in the movable frame  72 . The movable frame  72  is supported on a frame  76  by means of a pair of link arms  75 . A connection block  77  is provided projectingly on the rear face of the movable frame  72 , and a driving cylinder  78  is disposed between the connection block  77  and the frame  76 . As the driving cylinder  78  is expanded and contracted, the movable frame  72  can be moved back and forth between a parison receiving position (solid line in FIG. 1) in which the metallic mold  74  is positioned just below the cross head  70  and a blow position (imaginary line in FIG. 1) in which the metal mold  74  is positioned just below blow cylinders  79  which will be hereinafter described. 
     As seen from FIG. 2, each of the blow cylinders  79  is formed from a fixed casing  80  and a movable rod  81 , and an air mandrel  82  is connected to an end of the rod  81 . The blow cylinder  79  can drive the rod  81  and the air mandrel  82  upwardly and downwardly by an air pressure or a hydraulic pressure, and the air mandrel  82  can jet clean air from an end thereof when an air source is connected to the air mandrel  82 . An accommodating case  84  is mounted on the lower face of a horizontal base  83  to which the blow cylinders  79  are attached. The accommodating case  84  has a fully enclosed structure except that it has, in a bottom wall thereof, round holes  84   a  for passing the rods  81  and the air mandrels  82  therethrough. Air pipes  87  for supplying clean air are accommodated in the accommodating case  84 , and the accommodating case  84  is normally filled with clean air. It is to be noted that the accommodating case  84  can accommodate the entire of the air mandrels  82  when the air mandrels  82  is moved upwardly. 
     As shown in FIG. 3, seal dies  85  are provided between the lower face of the accommodating case  84  and the upper face of the metallic mold  74  and are opened or closed by a cylinder not shown to seal an upper end portion of a parison. 
     Operation of the blow molding apparatus is described below. 
     When parisons  86  are extruded to a fixed length from the parison molding nozzles  71 , the metallic mold  74  is closed, and the parisons  86  is cut by cutter apparatus not shown provided on the cross head  70 . Then, the movable frame  72  is moved to the blow position. Then, if the blow cylinders  79  are expanded there, then the ends of the blow cylinders  79  are inserted into the parisons  86  in the metallic mold  74  (imaginary line in FIG.  2 ), and therefore, the parisons  86  can be blow molded by blowing clean air into the parisons  86 . It is to be noted that, as seen in FIG. 3, before the air mandrel  82  is moved upwardly, the seal dies  85  stand by at a position a little above the level of the upper face of the metallic mold  74  at which they hold the air mandrels  82  therebetween, and if the air mandrels  82  are moved upwardly, then the seal dies  85  are closed to mold and seal upper end portions of the parisons  86 . Thereafter, if the metallic mold  74  is opened and the seal dies  85  are opened, then such hollow articles each having such a cap element as shown in FIG. 4 are discharged downwardly. By thereafter repeating similar operations, hollow articles can be produced successively. In the operations described above, the air mandrels  82  are cleaned by clean air supplied from the air pipes  87  while they remain accommodated in the accommodating case  84 . 
     Since the blow molding method and apparatus described in the prior art is constructed in such a manner as described above, it has the following subjects. 
     (a) After a hollow article wherein an opening of a vessel body is temporarily closed up with a cap element is molded, it is transported to a filling apparatus provided separately. Then, by the filling apparatus, only the outside of the hollow article is sterilized and the upper end is unsealed, and then filling and sealing are performed. Where the blow molding apparatus and the filling apparatus are formed separately from each other in this manner, temporary sealing, unsealing, filling and capping steps are required to produce a filled up hollow article. Consequently, the process is complicated, and a sterilizing operation must be performed in each of the steps. 
     (b) In a process wherein the metallic mold is moved back and forth in an inclined direction between the parison receiving position just below the cross head and the blow position in which the metallic mold is positioned just below the blow cylinder, there is the possibility that some foreign substances may be admitted into the inside of the parison. 
     (c) Since the ends of the air mandrels are inserted into parisons in the metallic mold and air from the air source is blown into the parisons to blow mold the parisons, there is the possibility that some foreign substances may be admitted into the insides of the parisons from the air source or a pipe system. 
     (d) The risk that, if hydraulic operating fluid leaks from the driving cylinders, hydraulic units or the pipe system used for the movement of the metallic mold, for the opening and closing of the metallic mold or for the upward and downward movement of the air mandrels, then hollow articles may be polluted or mist of the hydraulic operating fluid may enter the insides of the parisons or otherwise the inner faces of the hollow articles may be polluted is always present. Particularly, if hydraulic operating fluid leaks from the driving cylinders for the air mandrels, then since hollow articles are present below the driving cylinders, there is the possibility that the hydraulic operating fluid may enter the hollow articles via the air mandrels. 
     (e) Where the cutter of each of the cutter apparatus for cutting a parison is an electrothermal hot cutter, there is the possibility that the parison (plastic) may be molted by the heated cutter until volatile gas or fine carbonized particles of the plastic are scattered into the air and the inside of the parison is polluted with them. 
     (f) Since a filling cylinder which sucks and discharges a fixed amount of liquid is usually used for filling of liquid by a filling apparatus, the liquid is likely to stay in the inside of the filling cylinder and so forth and cleaning or sterilization of it cannot be performed readily. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a simultaneous filling blow molding method and apparatus which can prevent invasion of germs or foreign substances into the inside of a hollow article molded by the blow molding apparatus when a medicine or food is filled into the vessel. 
     In order to attain the object described above, in a simultaneous filling blow molding method and apparatus according to the present invention, a cross head mounted at an end portion of an extruder for extruding a parison between a pair of elements of a metallic mold and a filling nozzle lifting apparatus having a filling nozzle are provided in parallel, and opening and closing of the metallic mold by a mold clamping apparatus, back and forth movement of the mold clamping apparatus between a parison receiving position and a filling position by a metallic mold feeding apparatus, upward and downward movement of the filling nozzle and back and forth movement of a parison cutter of a parison cutting apparatus are electrically operated. Further, a metallic mold body of the metallic mold is formed from a ventilation material, through which air in the metallic mold is sucked by vacuum to expand the parison. Furthermore, a clean air box is constructed so that it can accommodate the filling nozzle, and clean air is jetted from a jetting hole provided in a lower wall of the clean air box so that a clean air atmosphere may be provided above the metallic mold. In addition, a liquid filling apparatus is constructed with a pipe construction, and a fixed amount filling solenoid valve is provided to prevent staying of liquid in a liquid flow path. 
     By constructing the simultaneous filling blow molding apparatus in this manner, prevention of pollution to and elimination of germs from a molded article can be achieved. 
     The above and other objects, features, and advantages of the present invention will become apparent from the following description based on the accompanying drawings which illustrate an example of a preferred embodiment of the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a view showing a conventional blow molding apparatus; 
     FIG. 2 is an enlarged view illustrating upwardly and downwardly moved conditions of an air mandrel shown in FIG. 1; 
     FIG. 3 is a vertical sectional view of the air mandrel of FIG. 2; 
     Fig. 4 is a perspective view of an entire conventional hollow article; 
     FIG. 5 is a schematic view showing a first embodiment of a simultaneous filling blow molding apparatus of the present invention; 
     FIG. 6 is a side elevational view of the simultaneous filling blow molding apparatus of FIG. 5; 
     FIG. 7 is a plan view of a mold clamping apparatus shown in FIG. 6; 
     FIG. 8 is a sectional view of a metallic mold; 
     FIG. 9 a  is a view showing a parison extruded between the metallic mold; 
     FIG. 9 b  is a view showing the metallic mold body in a closed condition; 
     FIG. 9 c  is a view showing the parison in an expanded condition; 
     FIG. 9 d  is a view showing a molded article in which fluid is being filled; 
     FIG. 9 e  is a view showing a pressure sealing metallic mold in a closed condition; 
     FIG. 9 f  is a view showing the metallic mold in an opened condition; 
     FIG. 10 is a schematic view showing a second embodiment of a simultaneous filling blow molding apparatus of the present invention; 
     FIG. 11 is a schematic view of an exhaust air hood; 
     FIG. 12 is a side elevational view of the exhaust air hood of FIG. 11; 
     FIG. 13 a  is a view showing a parison extruded between a metallic mold; 
     FIG. 13 b  is a view showing the metallic mold body in a closed condition; 
     FIG. 13 c  is a view showing a parison in an expanded condition; 
     FIG. 13 d  is a view showing a molded article in which liquid is being filled; 
     FIG. 13 e  is a view showing a pressure sealing metallic mold in a closed condition; 
     FIG. 13 f  is a view showing the metallic mold in an opened condition; 
     FIG. 14 is a schematic view showing a third embodiment of a simultaneous filling blow molding apparatus of the present invention; 
     FIG. 15 is a schematic sectional view showing a drop preventing solenoid valve; 
     FIG. 16 a  is a view illustrating a condition of a liquid drop at an end of a filling nozzle; and 
     FIG. 16 b  is a view illustrating a condition wherein the liquid drop at the end of the filling nozzle is absorbed. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention are described below with reference to the drawings. 
     (First Embodiment) 
     FIG. 5 is a schematic view showing a first embodiment of a simultaneous filling blow molding apparatus of the present invention, and FIG. 6 is a side elevational view of the simultaneous filling blow molding apparatus. 
     Referring to FIGS. 5 and 6, denoted by reference numeral  21  is a frame of a blow molding apparatus, and a filling nozzle lifting apparatus  35  having a filling nozzle  36  for filling liquid is placed at an upper portion of the frame  21 . An extruder  22  and a cross head  23  connected to an end portion of the extruder  22  are located on the left side of the filling nozzle lifting apparatus  35  in FIG. 5. A parison cutting apparatus  25  for cutting a parison  24  extruded from the cross head  23  using a parison cutter is located just below the cross head  23 . The parison cutting apparatus  25  is driven by a motor (not shown). A molded article supporting apparatus  62  having support pins  61  is located below the filling nozzle lifting apparatus  35 . 
     An AC servomotor  27  having a rotary encoder  26  is provided at a lower portion of the frame  21 . A ball screw  29  is connected for rotation to the AC servomotor  27  via a coupling  28 , and a ball nut  30  is held in threaded engagement with the ball screw  29 . A connection member  31  is secured to the ball nut  30 , and a metallic mold feeding apparatus  33  fitted for movement on a guide bar  32  is disposed above the connection member  31 . A mold clamping apparatus  34  for opening or closing a metallic mold  1  is mounted on the metallic mold feeding apparatus  33 . In particular, the mold clamping apparatus  34  and the metallic mold  1  mounted on the metallic mold feeding apparatus  33  are movable back and forth between a filling position B indicated by solid lines in FIG. 5 and a parison receiving position A (indicated by imaginary in FIG.  5 ). 
     A molded article holding apparatus  63  which is moved back and forth between the filling position B and a molded article discharging position C by the back and forth movement of the mold clamping apparatus  34  is mounted on a side portion (right sight in FIG. 5) of the mold clamping apparatus  34 . 
     A selecting apparatus  64  for selectively separating a molded article and burrs from each other is provided below the molded article holding apparatus  63  at the molded article discharging position C. In particular, the selecting apparatus  64  includes an inclined movable chute  66  provided just below the molded article holding apparatus  63  and movable back and forth in the leftward and rightward directions in FIG. 5 by an electric motor  65 , a belt conveyor  67  provided at a lower location on the right side of the movable chute  66  for transporting a molded article, and another belt conveyor  68  provided below the molded article holding apparatus  63  for receiving and transporting burrs dropping thereto. 
     A liquid filling apparatus  90  is connected to the filling nozzle  36  of the filling nozzle lifting apparatus  35 . It is to be noted that the liquid filling apparatus is described in detail in the description of Embodiment 3. 
     Next, the mold clamping apparatus  34  is described with reference to FIGS. 6 and 7. 
     A metallic mold body  2  of the metallic mold  1  is composed of a first metallic mold body  2 A and a second metallic mold body  2 B. The second metallic mold body  2 B is connected to a toggle mechanism  43  formed from a pair of foldable first and second toggle members  41  and  42  via a second metallic mold holding member  44  and a clevis  45 . A guide block  47  which holds a pivotally supporting portion  46  which connects the first and second toggle members  41  and  42  for folding movement to each other is guided by a pair of guide bars  48  and  49 . 
     The guide block  47  is supported for back and forth movement in an axial direction by a feed screw member  51  such as a ball screw which is rotated by a servomotor  50 . A first metallic mold holding member  52  is provided on the first metallic mold body  2 A. 
     A pair of rods  55  and  56  are connected to a rear plate  54  which is connected to the second toggle member  42  by a clevis  53 . The rods  55  and  56  are fixedly connected to a connection member  57  connected to the first metallic mold holding member  52 , and the rod  55  extends for operation through the second metallic mold holding member  44 . The rear plate  54 , rods  55  and  56 , and connection member  57  construct a metal mold opening and closing mechanism  58  for the metallic mold  1 . A fixed table  33 a having holes in which the rods  55  and  56  are fitted for sliding movement is securely mounted on the metallic mold feeding apparatus  33 , and the servomotor  50  for operating the toggle mechanism  43  is provided at an upper portion of the fixed table  33   a.    
     Accordingly, if the servomotor  50  in the construction described above is rendered operative to move the guide block  47  via the feed screw member  51 , then the first and second toggle members  41  and  42  exhibit a linearly aligned condition or a folded condition along the positions (imaginary line in FIG.  7 ), respectively. When the first and second toggle members  41  and  42  exhibit a linearly aligned condition, since the metallic mold holding members  44  and  52  are moved in mutually approaching directions by the metallic mold opening and closing mechanism  58 , the metallic mold bodies  2 A and  2 B are put into a closed condition. But, when the toggle members  41  and  42  exhibit a folded condition, the metallic mold holding members  44  and  52  are moved in directions opposite to those described above and the metallic mold bodies  2 A and  2 B are put into an open condition. 
     While the mold clamping apparatus  34  employing the toggle mechanism  43  is described in detail above, the mold clamping apparatus may otherwise be constructed with a direct mechanism using a servomotor and a rotatable screw. Further, while the servomotor is employed in the foregoing description, some other electric motor including a step motor may be used instead. 
     Next, the metallic mold  1  is described with reference to FIG.  8 . The metallic mold  1  is composed of the metallic mold body  2 , a cooling member  3 , a pressure sealing metallic mold  4  provided for sliding movement above the metallic mold body  2  and the cooling member  3 , and a parison sucking plate  5  located above the pressure sealing metallic mold  4 . In particular, the metallic mold body  2  is mounted on the metallic mold holding members  52  and  44  with the cooling member  3  interposed therebetween. The metallic mold body  2  is formed from a porous material serving as a ventilation member such as, for example, a sintered metal of stainless steel or a ceramic material, and a cavity  2   a  is formed on opposing faces of the two components of the metallic mold body  2 . A suction jacket or suction hole serving as an air suction path  2   b  for sucking air from the cavity  2   a  is formed on the metallic mold body  2  such that it surrounds the cavity  2   a,  and is connected to a vacuum pump (not shown) serving as a suction apparatus. A cooling water jacket or cooling water hole serving as a cooling water path  3   a  for cooling the metallic mold body  2  is formed on the cooling member  3  and connected to a cooling water pump (not shown). It is to be noted that, while, in the embodiment described above, a porous material as a ventilation member is used for the metallic mold body  2 , alternatively a large number of holes of a small diameter or elongated slits of a small width may be worked on the surface of the cavity. 
     Next, a simultaneous filling step by the simultaneous filling blow molding apparatus described above is described with reference to FIG.  5  and FIGS. 9 a  to  9   f.    
     The metallic mold  1  stands by at the filling position B in a condition wherein it is opened by the mold clamping apparatus  34 . This position of the metallic mold  1  is detected by the rotary encoder  26 . A molten resin supplied from the extruder  22  to the cross head  23  is extruded downwardly as a tubular parison  24  from the cross head  23 . 
     (a) In a condition wherein a predetermined length of the parison  24  is extruded from the cross head  23 , the AC servomotor  27  of the metallic mold feeding apparatus  33  is driven to rotate in the advancing direction. Consequently, the ball screw  29  is rotated via the coupling  28 , and this rotational movement is converted into a linear movement by the ball nut  30  which is held in meshing engagement with the ball screw  29 . In particular, the ball nut  30  is advanced in the leftward direction in FIG. 5, and the connection member  31 , metallic mold feeding apparatus  33 , mold clamping apparatus  34  and metallic mold  1  which are integrated with the ball nut  30  are advanced from the filling position B to the parison receiving position A. It is to be noted that the location above the metallic mold  1  is normally covered with germ-free air of the class 100 or less. The class 100 signifies a condition wherein less than 100 fine particles of 0.5 μm or more are included in air of 1 cubit feet. 
     (b) The parison  24  extruded from the cross head  23  is held between the two components of the metallic mold body  2  and a lower end of the parison  24  is pressed into a sealed condition, and then an upper portion of the parison  24  is cut by the parison cutting apparatus  25 . Since the parison  24  is not held in close contact with the face of the cavity  2   a  of the metallic mold body  2  being cooled, the temperature of the resin is higher than 120° C. at the lowest and a sufficient sterilization effect is achieved. 
     (c) The AC servomotor  27  for the metallic mold feeding apparatus  33  is driven to rotate in the retracting direction so that the metallic mold  1  holding the parison  24  which is open at the top thereof is fed from the parison receiving position A to the filling position B. During the movement, the parison  24  is sucked by vacuum to the face of the cavity  2   a  of the metallic mold body  2  so that a hollow article of a predetermined shape is molded. Further, an upper portion of the parison  24  is closely contacted with the parison sucking plate  5 . During feeding and vacuum suction of the metallic mold  1 , since the location above the metallic mold  1  is in a clean air atmosphere, germs or foreign substances are not admitted into the inside of the vessel. 
     (d) The filling nozzle  36  is moved down and inserted into the hollow article, and liquid is filled into the hollow article. The molded article filled with the liquid is cooled from the outer face thereof by the metallic mold  1  and from the inner face thereof by the filled liquid. 
     (e) The filling nozzle  36  is moved up and the pressure sealing metallic mold  4  is closed to seal the opening of the molded article filled with the liquid. Then, the upper portion of the parison  24  is released from the parison sucking plate  5 . 
     (f) The support pins  61  of the molded article supporting apparatus  62  provided below the metallic mold  1  are moved up and inserted into a location below the molded article to support the the molded article thereon, and then the metallic mold  1  is opened. 
     In the steps a to d described above, air present in the inside of the parison  24  is heated and sterilized by the temperature (higher than 120° C. at the lowest) of the parison. Further, since the air in the inside of the parison  24  is expanded by the heat and flows out to the outside because it is higher in temperature than the external air, foreign substances or polluted air is not sucked into the parison  24  at all. 
     Then, as seen in FIG. 5, when the metallic mold  1  opened as described above moves to the parison receiving position A in order to hold the parison  24  extruded from the cross head  23 , the molded article holding apparatus  63  mounted on the right side of the mold clamping apparatus  34  in FIG. 5 is moved to the filling position B, at which it holds the molded article. Then, when the metallic mold  1  holding the parison  24  thereon is moved to the filling position B, the molded article holding apparatus  63  is moved to the molded article discharging position C. Since the inclined movable chute  66  which is moved back and forth by the electric motor  65  is provided below the molded article holding apparatus  63  at the molded article discharging position C, when the molded article is to be dropped, the movable chute  66  is moved to the location below the molded article holding apparatus  63  to receive the molded article, and the molded article is carried out to the outside of the machine by the belt conveyor  67  provided at the lower location on the right side of the movable chute  66 . Further, when burrs are to be dropped, the movable chute  66  is moved from the location below the molded article holding apparatus  63 , and the burrs are received on the belt conveyor  68  provided below the molded article holding apparatus  63  and then carried out to the outside of the machine. 
     (Embodiment 2) 
     FIG. 10 is a general schematic view showing a second embodiment of a simultaneous filling blow molding apparatus of the present invention. As seen from FIG. 10, in the present embodiment, a filling nozzle  36  is constructed so that it can be accommodated into a clean air box  11  and an upper portion of an electrothermal hot cutter  25  of a parison cutting apparatus is covered with an exhaust air hood  15 . Since the other construction is substantially similar to that of the first embodiment, description thereof is omitted here. 
     As seen in FIG. 10, the filling nozzle  36  can be accommodated into the clean air box  11 . In particular, the filling nozzle  36  projects, when it is moved down, from the clean air box  11 , but is accommodated into the clean air box  11  when it is moved up. A clean air pipe  12  is connected to the clean air box  11  so that clean air is supplied to the clean air box  11  via a flow rate control valve  13 . Since the filling nozzle  36  is accommodated in the clean air box  11  except during filling as described above, germs or foreign substances do not stick to the filling nozzle  36  at all. Further, jetting holes  14 , including a hole through which the filling nozzle  36  moves up and down, for jetting clean air therethrough are formed in a lower wall of the clean air box  11 . 
     FIG. 11 is a schematic view of the exhaust air hood, and FIG. 12 is a side elevational view of the exhaust air hood. 
     As seen in FIGS. 11 and 12, an upper portion of the electrothermal hot cutter  25  provided between the metallic mold  1  at the parison receiving position A and the cross head  23  is covered with the exhaust air hood  15 , and an air sucking pipe  16  which is communicated with a blower or the like is connected to an upper portion of the exhaust air hood  15 . 
     Next, the function of the exhaust air hood  15  is described. In particular, when a parison  24  is to be cut by the electrothermal hot cutter  25 , the parison  24 , that is, the plastic, is melted by the heated cutter  25 , and volatile gases and/or carbonized fine particles of the plastic are scattered into the air, admitted into the inside of the parison  24  and sticks to or is dissolved into liquid, which is filled in a later step, to pollute the filled liquid. Therefore, immediately after the parison  24  is cut, those volatile gases and carbonized fine particles are sucked by the exhaust air hood  15  provided above the electrothermal hot cutter  25  and discharged to another location, for example, to the outside of the clean room via the air sucking pipe  16 . 
     As shown in FIG. 12, an inlet hole  17  for clean air is formed through a central portion of the cross head  23 , and a clean air pipe  18  is connected to the top end of the inlet hole  17 . Clean air supplied into the inlet hole  17  via a flow rate control valve  19  provided for the clean air pipe  18  is filled into the parison  24  from the lower end of the inlet hole  17 . 
     Next, a simultaneous filling blow molding process by the simultaneous filling blow molding apparatus described above is described with reference to FIGS. 13 a  to  13   f.    
     (a) A cylindrical parison  24  is extruded from the cross head  23  into the metallic mold  1 . Upon extrusion of the parison  24 , in order to keep the parison  24  in a cylindrical shape, germ-free clean air of the class 100 or less at the lowest is filled by a small amount into the parison  24  through the inlet hole  17  provided at the central portion of the cross head  23 . 
     (b) The parison  24  extruded from the cross head  23  is held between the two components of the metallic mold body  2  and a lower end of the parison  24  is pressed into a sealed condition, and then an upper portion of the parison  24  is cut by the electrothermal hot cutter  25  serving as a parison cutting apparatus. Thereupon, air filled in the parison  24  flows out to the outside through the cut portion of the parison  24 . Since the parison  24  is not held in close contact with the face of the face of the cavity  2   a  of the metallic mold body  2  being cooled, the temperature of the resin is higher than 120° C. at the lowest and a sufficient sterilization effect is achieved. 
     volatile gases and/or carbonized fine particles of the plastic produced when the parison  24  is cut by the electrothermal hot cutter  25  are sucked by the exhaust air hood  15  provided above the electrothermal hot cutter  25  and discharge d to the outside of the clean room. The suction by the exhaust air hood  15  is performed always or immediately after the parison  24  is cut. 
     (c) The metallic mold  1  holding the parison  24  which is open at the top thereof is fed from the parison receiving position A to the filling position B. During the movement, the parison  24  is sucked by vacuum to the face of the cavity  2   a  of the metallic mold body  2  so that a hollow article of a predetermined shape is molded. 
     (d) The filling nozzle  36  accommodated in the clean air box  11  is moved down and inserted into the hollow article, and liquid is filled into the hollow article. The molded article filled with the liquid is cooled from the outer face thereof by the metallic mold  1  and from the inner face thereof by the filled liquid. 
     (e) The filling nozzle  36  is moved up and accommodated into the clean air box  11 , and the pressure sealing metallic mold  4  is closed so that the opening of the molded article filled with the liquid is sealed. It is to be noted that, in the steps described above, since the atmosphere above the metallic mold  1  is such that clean air continuously supplied into the clean air box  11  flows out from jetting holes  14  and covers over the opening of the parison  24 , there is no possibility at all that germs or foreign substances may be admitted into the parison  24 . 
     (f) The metallic mold  1  is opened, and the molded article is dropped from the metallic mold  1  or held by the molded article holding apparatus  63  and transported to a next step. 
     While, in the first and second embodiments described above, a parison  24  is sucked by vacuum to the face of the cavity  2   a  of the metallic mold body  2  to mold a hollow article, clean air may alternatively be blown into the inside of the parison  24  to mold a hollow article. Further, while, in the second embodiment, a small amount of clean air is filled into the parison  24  in order to hold the parison  24  in a cylindrical shape when the parison  24  is to be extruded, clean air need not be inserted into the parison  24  depending upon the characteristic or the condition of the parison  24 . Further, while the parison cutter of the parison cutting apparatus is formed as the electrothermal hot cutter  25  and the upper portion of the electrothermal hot cutter  25  is covered with the exhaust air hood  15 , where a cold cutter is used for the parison cutter instead, the exhaust air hood  15  is not required. 
     (Embodiment 3) 
     A liquid filling apparatus  90  of a simultaneous filling blow molding apparatus is described in detail with reference to FIG.  14 . 
     As seen in FIG. 14, the liquid filling apparatus  90  is composed of a liquid pressure feeding system D and a liquid filling system E. The liquid pressure feeding system D includes a liquid storage tank  91 , a pump  92 , and a heat exchanger  93 , which are connected in series by means of a pipe line. The pipe line from the heat exchanger  93  is branched into two pipe lines. One of the pipe lines is connected to the liquid filling system E, and a pressure gage  94  and a thermometer  95  are attached to the connection pipe line. The other pipe line is connected to the suction side of the pump  92 . 
     The pressure gage  94  is connected to a diaphragm valve  96  interposed in the pipe line between the pump  92  and the heat exchanger  93 . The thermometer  95  is connected to another diaphragm valve  97  provided on the entrance side of a pipe for cooling water or a heating medium for the heat exchanger  93 . 
     The liquid filling system E includes a fixed amount filling solenoid valve  98 , a drop preventing solenoid valve  99  and a throttle valve  100 , which are connected in series by means of a pipe line. It is to be noted that the fixed amount filling solenoid valve  98  is connected to a connection circuit to the liquid pressure feeding system D, and the throttle valve  100  is connected to the filling nozzle  36  via a pipe line. 
     The fixed amount filling solenoid valve  98  allows filling of a fixed amount of liquid by means of a timer provided for the solenoid valve  98 . The timer can be set with and store a numerical value. Further, since the solenoid valve  98  used has a high responsibility, a high degree of accuracy of filling can be obtained repetitively. 
     As shown in FIG. 15, the drop preventing solenoid valve  99  includes bellows  101  provided on a side face of the pipe line of the drop preventing solenoid valve  99  and having a curved face portion, an iron core  102  for pressing the curved face portion of the bellows  101 , and a coil  103  for operating the iron core  102 . 
     The curved face portion of the bellows  101  is normally pressed by the weight of the iron core  102  or a spring (not shown) so that it exhibits a condition of a flat face, but if the coil  103  is energized, then the iron core  102  is moved upwardly to put the curved face portion of the bellows  101  into a curved face condition as indicated by an imaginary line to increase the volume of the pipe line of the drop preventing solenoid valve  99  to suck a liquid drop  104  at the end of the filling nozzle  36  immediately after filling as shown in FIG. 16 a  into the filling nozzle  36  as shown in FIG. 16 b.    
     The throttle valve  100  is principally used to enable or disable supply of liquid to the filling nozzle  36 . 
     As shown in FIG. 14, the filling nozzle  36  of the filling nozzle lifting apparatus  35  is moved down, when filling is to be performed, to insert the end thereof into a hollow article and is then pulled up after the filling is completed, by rotating a ball screw  39  held in meshing engagement with a ball nut  38  of a nozzle supporting plate  37  by means of a motor  40 . 
     Next, operation of the liquid filling apparatus described above is described with reference to FIG.  14 . 
     In the liquid pressure feeding system D, liquid of the liquid storage tank  91  is fed into the heat exchanger  93  by the pump  92 . The liquid is controlled to a fixed temperature (an arbitrary temperature within the range of approximately 20 to 25° C.) by the heat exchanger  93  so that it has a fixed viscosity, and then it is returned to the entrance of the pump  92  so that it is thereafter circulated. It is to be noted that the temperature of the liquid is detected by the thermometer  95  provided for the connection pipe line between the liquid pressure feeding system D and the liquid filling system E and a diaphragm valve  97  provided on the entrance side of the pipe line for the cooling water or heating medium of the heat exchanger  93  is controlled based on the detected temperature of the liquid to keep the temperature of the liquid to the fixed temperature. The pressure of the liquid is detected by the pressure gage  94  provided for the connection pipe line between the liquid pressure feeding system D and the liquid filling system E and the diaphragm valve  96  provided for the pipe line between the pump  92  and the heat exchanger  93  is controlled based on the detected pressure of the liquid to keep the pressure of the liquid to a fixed pressure (an arbitrary pressure within the range of 0.1 to 2 kgf/cm 2 ). T he liquid kept to the fixed temperature and the fixed pressure by the liquid pressure feeding system D is filled, when the fixed amount filling solenoid valve  98  of the liquid filling system E is opened, into the inside of a hollow article from the filling nozzle  36  by a fixed amount defined by the timer provided for the solenoid valve  98 . Further, since the solenoid valve  98  has a high responsibility (the responsibility is 5 to 10 ms), a high degree of accuracy of filling can be achieved. 
     For example, in order to fill liquid by 5 ml or less, filling is performed with a filling pressure of 1 kgf/cm 2  or less, a filling tolerance of 5 ml ±3% or less, a filling nozzle diameter of 2 mm or less and a filling time of 2 sec or less. 
     If the fixed amount filling solenoid valve  98  is closed to end the filling, then the drop preventing solenoid valve  99  is energized to increase the volume of the flow path of the valve  99  to suck a liquid drop  104  at the end of the filling nozzle  36  immediately after the filling into the filling nozzle  36 . By the suction of the liquid drop  104 , it can be prevented that the liquid drop  104  sticking to the end of the filling nozzle  36  drops into the molded article by vibrations or the like when the filling nozzle  36  is moved up. This effect is particularly significant where the filling amount is small, and a dispersion in filling amount can be prevented. 
     Since the present invention is constructed in such a manner as described above, the following effects are exhibited. 
     (a) Since the simultaneous filling blow molding apparatus has a characteristic of an electrically driven blow molding apparatus, prevention of pollution to and elimination of germs from a molded particle can be anticipated. In particular, since the driving mechanism for the filling nozzle lifting apparatus and the driving mechanisms for the mold clamping apparatus, mold feeding apparatus and parison cutting apparatus which are located above the metallic mold are not driven hydraulically but electrically, pollution to a molded article arising from leakage of the hydraulic operating liquid or from oil mist is prevented. 
     (b) Since the location above the metallic mold which is moved between the parison receiving position and the filling position is covered with clean air, germs or foreign substances are prevented from entering the parison through an opening (cut portion) of the parison like. 
     (C) Where expansion of a parison is performed by vacuum suction, elimination of germs is easy comparing with an alternative case wherein such expansion is performed by blowing in of air. 
     (d) Where the filling nozzle is constructed such that it can be accommodated into the clean air box, since the filling nozzle is accommodated in the clean air box except during filling, germs or foreign substances are prevented from sticking to the filling nozzle. 
     (e) Where the location above the electrothermal hot cutter is covered with the exhaust air hood, volatile gases and/or carbonized fine particles produced when a parison is cut by the electrothermal hot cutter are sucked by the exhaust air hood and discharged to the outside of the clean room, and consequently, the inside of the parison is prevented from being polluted at all. 
     (f) Since the liquid filling apparatus is connected by a pipe and the solenoid valves and other components are simplified in flow path structure and include no staying location, they can be cleaned and sterilized readily. Further, since the solenoid valves of a high responsibility and the drop preventing solenoid valve are used, a filling amount with a high degree of accuracy can be obtained repetitively. 
     It is to be understood, however, that although the characteristics and advantages of the present invention have been set forth in the foregoing description, the disclosure is illustrative only, and changes may be made in the arrangement of the parts within the scope of the appended claims.