Patent Publication Number: US-2022234273-A1

Title: Blow molding device

Description:
TECHNICAL FIELD 
     This application relates to a blow molding apparatus that blow molds a synthetic resin preform into a container having a predetermined shape, in particular to a blow molding apparatus that uses an incompressible fluid, such as a liquid, as a pressurizing medium for performing blow molding. 
     BACKGROUND 
     Synthetic resin containers, typical examples of which include polypropylene (PP) bottles and polyethylene terephthalate (PET) bottles, are used to contain a variety of contents, such as beverages, cosmetics, pharmaceuticals, liquid detergents, or shampoo. Such a container is typically manufactured by blow molding a synthetic resin preform into a predetermined shape using a blow molding apparatus, after the preform is heated to a temperature at which a stretching effect may be achieved. 
     Blow molding apparatuses that use incompressible fluids, such as pressurized liquids, instead of pressurized air, as pressurizing media to be supplied into preforms are known. In this case, contents which are to be ultimately filled into containers as products may be used as pressurizing media. By doing so, the step of filling contents into a container may be omitted, and the production process and the configuration of manufacturing apparatus may be simplified. 
     For example, Patent Literature (PTL) 1 describes a blow molding apparatus including a mold for blow molding, a blow nozzle configured to be disposed above the mold, a pressurized fluid supply unit configured to supply a pressurized liquid to the blow nozzle, and a blow nozzle moving unit configured to cause a relative movement of the blow nozzle between a connected position in which the blow nozzle is connected to a mouth tubular portion of a preform that has been placed in the mold and a standby position in which the blow nozzle is upward and away from the mouth tubular portion. In the described blow molding apparatus, the preform is molded into a container having a shape corresponding to a cavity of the mold, by supplying the pressurized liquid into the preform through the blow nozzle which is in the connected position. 
     CITATION LIST 
     Patent Literature 
     PTL 1: JP 2013-208834 A 
     SUMMARY 
     Technical Problem 
     In a known blow molding apparatus as described in PTL 1, after a container has been blow molded and when the blow nozzle is raised to its standby position so as to be disconnected from the mouth tubular portion of the container, a liquid (incompressible fluid) can drip down from the surface of the blow nozzle to which it has adhered. In particular, in a case in which a relatively highly viscous liquid, such as shampoo or liquid detergent, is used as a pressurized medium for blow molding, it takes long for the dripping down of the liquid to start from the blow nozzle after blow molding, and moreover, the liquid continues to run in a thin stream for a while. Accordingly, the liquid is likely to drip down from the blow nozzle onto the molded container or the mold from which the molded container has been removed, thus causing the problem of spoiling them. 
     It would be helpful to provide a blow molding apparatus capable of preventing an incompressible fluid from dripping down from the blow nozzle and adhering to a molded container or a mold, after the container has been blow molded and the blow nozzle has been separated from the mouth tubular portion of the preform. 
     Solution to Problem 
     One aspect of the present disclosure resides in a blow molding apparatus including: 
     a mold for blow molding; 
     a blow nozzle configured to be disposed above the mold; 
     a pressurized fluid supply unit configured to supply a pressurized incompressible fluid to the blow nozzle; and 
     a blow nozzle moving unit configured to cause a relative movement of the blow nozzle between a connected position in which the blow nozzle is connected to a mouth tubular portion of a preform that has been placed in the mold and a standby position in which the blow nozzle is upward and away from the mouth tubular portion, wherein 
     the preform is molded into a container having a shape corresponding to a cavity of the mold, by supplying the pressurized incompressible fluid into the preform through the blow nozzle which is in the connected position, the blow molding apparatus including: 
     a drawing member including a drawing port; 
     a drawing pump configured to be connected to the drawing member; and 
     a drawing member moving unit configured to move the drawing member so that the drawing port is positioned below the blow nozzle, after the container has been molded and the blow nozzle has been moved from the connected position to the standby position. 
     In a preferred embodiment of the blow molding apparatus configured as above, the drawing port is open in a horizontal direction. 
     In another preferred embodiment of the blow molding apparatus configured as above, the blow molding apparatus further includes: 
     a saucer; and 
     a saucer moving unit configured to move the saucer to below the blow nozzle on a lower side of the drawing member, after the container has been molded and the blow nozzle has been moved from the connected position to the standby position. 
     In still another preferred embodiment of the blow molding apparatus configured as above, after the drawing member moving unit has moved the drawing member so that the drawing port is positioned below the blow nozzle, the saucer moving unit moves the saucer to below the blow nozzle. 
     Advantageous Effect 
     According to the present disclosure, a blow molding apparatus capable of preventing an incompressible fluid from dripping down from the blow nozzle and adhering to a molded container or a mold, after the container has been blow molded and the blow nozzle has been separated from the mouth tubular portion of the preform can be provided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the accompanying drawings: 
         FIG. 1  illustrates a blow molding apparatus according to an embodiment of the present disclosure; 
         FIG. 2  is an enlarged sectional view illustrating a portion of the blow molding apparatus of  FIG. 1 ; 
         FIG. 3  is a plan view illustrating a mold and a drawing device of  FIG. 1 ; 
         FIG. 4  illustrates the blow molding apparatus in a state in which a blow nozzle has been moved from its standby position to its connected position; 
         FIG. 5  illustrates the blow molding apparatus in a state in which a preform is being blow molded; 
         FIG. 6  illustrates the blow molding apparatus in a state in which a drawing member has been moved so that a drawing port is positioned below the blow nozzle, after a container has been molded and the blow nozzle has been moved from its connected position to its standby position; 
         FIG. 7  is a plan view illustrating a positional relationship between the mold and the drawing device in the state of  FIG. 6 ; 
         FIG. 8  illustrates a blow molding apparatus including a liquid receiving device according to a modification; 
         FIG. 9  illustrates the blow molding apparatus in a state in which a drawing member has been moved so that a drawing port is positioned below a blow nozzle and in which a saucer has been moved to below the blow nozzle, after a container has been molded and the blow nozzle has been moved from its connected position to its standby position; and 
         FIG. 10  is a sectional view illustrating a blow nozzle according to a modification. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, the present disclosure will be described by illustration in more detail with reference to the drawings. 
     A blow molding apparatus  1  according to an embodiment of the present embodiment as illustrated in  FIG. 1  blow molds a synthetic resin preform  2 , using an incompressible fluid, which is to be ultimately filled into a container, as a pressurizing medium. Thus, the container C having a predetermined shape for containing the incompressible fluid as the contents is manufactured. The blow molding apparatus  1  includes a mold  10  for blow molding. 
     As illustrated in  FIG. 2 , the mold  10  includes a cavity  11  that defines a molding surface. The cavity  11  of the mold  10  has a bottle shape with an opening  11   a  provided in its upper end, so that the opening  11   a  is open at an upper surface of the mold  10 . 
     The preform P can be placed (fitted) in the mold  10 . In the present embodiment, as the preform P to be placed in the mold  10 , a preform that integrally includes a test tube-shaped body P 1  having a large-diameter upper portion and a cylindrical-shaped mouth tubular portion P 3  is illustrated as being used. The preform also integrally includes an undercut portion P 4  that is provided in an upper portion of the mouth tubular portion P 3  and protrudes toward the outer side in the radial direction, and a neck ring P 2  that is provided in a lower end of the mouth tubular portion P 3  and extends toward the outer side in the radial direction. In this case, the preform P is placed in the mold  10  in an upright position, with the mouth tubular portion  3  being arranged on the upper side, so that the mouth tubular portion P 3  protrudes above the upper surface of the mold  10  while the neck ring P 2  is placed on the upper surface of the mold  10  and that the body P 1  is positioned in the cavity  11  through the opening  11   a.  Additionally, the central axis of the preform P that has been placed in the mold  10  coincides with the central axis of the opening  11   a.    
     Although not illustrated in detail, the mold  10  is configured to be opened into left and right mold halves along the central axis of the opening  11   a.  By opening the mold  10  into left and right mold halves, a molded container can be removed from the mold  10 . 
     The preform P is not limited to a preform with the above shape, and preforms with various shapes, which include the mouth tubular portion P 3  and can be placed in the cavity  11  of the mold  10 , may be used. As the preform  2 , for example, it is possible to use a preform that has been obtained by forming a thermoplastic synthetic resin material, which exhibits stretchability when being heated, into a desired shape by injection molding, compression molding, extrusion molding, or the like. The thermoplastic synthetic resin material may be polypropylene (PP), polyethylene terephthalate (PET), polyethylene (PE), or the like. 
     As illustrated in  FIG. 1  and  FIG. 2 , a nozzle unit  20  is provided above the mold  10 . The nozzle unit  20  includes a body block  21 , and a blow nozzle  22  fixed to a lower end of the body block  21 . In the present embodiment, the body block  21  is configured by combining a plurality of members, although a detailed description thereof will be omitted. 
     As illustrated in  FIG. 2 , in the body block  21 , there is provided a supply flow path  23  extending in the vertical direction. The supply flow path  23  has a lower end that is connected to the blow nozzle  22 . 
     The blow nozzle  22  includes a nozzle body  22   a  formed in a cylindrical shape having a smaller diameter than the inner diameter of the mouth tubular portion P 3  of the preform P, and a large-diameter holding portion  22   b  integrally provided on the upper side of the nozzle body  22   a.  At the holding portion  22   b,  the blow nozzle  22  is held by and fixed to the inner surface of the body block  21 . The blow nozzle  22  is coaxial with the opening  11   a  of the mold  10 . 
     Additionally, the blow nozzle  22  does not necessarily need to have a cylindrical shape, and may have various shapes, such as an elliptical or polygonal tube shape, by which the blow nozzle  22  can be connected to the mouth tubular portion P 3  of the preform P. 
     A pressurized fluid supply unit  30  is connected to the supply flow path  23 . The pressurized fluid supply unit  30  may supply the incompressible fluid that has been pressurized to a predetermined pressure to the blow nozzle  22  through the supply flow path  23 . As the pressurized fluid supply unit  30 , for example, it is preferable to use a configuration in which a plunger pump is used as a pressure source. It is, however, possible to use another configuration, by which the incompressible fluid that has been pressurized to a predetermined pressure can be supplied to the blow nozzle  22 . 
     As the incompressible fluid that is to be supplied to the blow nozzle  22  by the pressurized fluid supply unit  30 , for example, a relatively highly viscous liquid, such as shampoo or liquid detergent, may be used. In this case, the incompressible fluid is preferably an incompressible fluid having a viscosity of not more than 10000 mPa·s during its supply into the preform P. 
     In the supply flow path  23 , a seal body  24  is disposed in a manner such that it is movable in the vertical direction, so as to open and close the blow nozzle  22 . When the seal body  24  is moved to its lower stroke end, a tapered lower end surface of the seal body  24  abuts against a tapered upper surface of the holding portion  22   b  of the blow nozzle  22 , and the blow nozzle  22  is thus closed. On the other hand, when the seal body  24  moves upward and away from the tapered upper surface of the holding portion  22   b,  the blow nozzle  22  is opened. 
     The nozzle unit  20  is driven by a blow nozzle moving unit  40 , so as to be raised and lowered along the central axis of the opening  11   a.  As the blow nozzle moving unit  40 , for example, it is possible to use a configuration in which a linear guide with a linear rail extending in the vertical direction and a slider movably arranged thereon is combined with a ball screw mechanism for converting rotational motion of an electric motor into linear motion. It is, however, possible to use another configuration. 
     When the nozzle unit  20  is moved to its lower stroke end by the blow nozzle moving unit  40 , the blow nozzle  22  is brought into its connected position (position illustrated in  FIG. 2 ), in which the nozzle body  22   a  is inserted into the mouth tubular portion P 3  of the preform P that has been placed in the mold  10 , so as to be connected to the mouth tubular portion P 3 . On the other hand, when the nozzle unit  20  is moved to its upper stroke end by the blow nozzle moving unit  40 , the blow nozzle  22  is brought into its standby position (position illustrated in  FIG. 1 ), in which the nozzle body  22   a  is positioned above and away from the mouth tubular portion P 3  of the preform P that has been placed in the mold  10 , so as to be disconnected from the mouth tubular portion P 3 . 
     As illustrated in  FIG. 2 , the body block  21  is provided, at a lower end thereof, with an annular-shaped sealing claw portion  25  that surrounds the outer periphery of the nozzle body  22   a.  When the nozzle unit  20  is moved to its lower stroke end and the nozzle body  22   a  is connected to the mouth tubular portion P 3  of the preform P, the sealing claw portion  25  abuts against an upper surface of the neck ring P 2 , so that the preform P is fixed and held in the mold  10 . 
     The blow molding apparatus  1  may also be configured to include a stretching rod  26  for stretching the preform P in its longitudinal direction. The stretching rod  26  is slidably fitted in a hole provided along the axial center of the seal body  24 , and the stretching rod  26  is movable in the axial direction, that is, the vertical direction relative to the seal body  24 . At the time of blow molding, the preform P that has been placed in the mold  10  can be axially (longitudinally) stretched by the stretching rod  26  in the cavity  11 , by moving the stretching rod  26  downward relative to the seal body  24 . 
     As illustrated in  FIG. 1 , the blow molding apparatus  1  includes a drawing device  50 . The drawing device  50  is used after blow molding of a container, so as to prevent the incompressible fluid from dripping down from the blow nozzle  22  and adhering to the molded container or the mold  10 . The drawing device  50  is disposed beside the blow nozzle  22 . 
     As illustrated in  FIG. 1  and  FIG. 3 , the drawing device  50  has a drawing member  51 , a drawing pump  52 , and a drawing member moving unit  53 . 
     The drawing member  51  is formed of a pipe material including a drawing passage  51   a,  and the drawing member  51  has a drawing port  51   b  formed at its end. An end portion of the pipe member is bent in an L-shape along the horizontal direction, and the drawing port  51   b  is open in the horizontal direction. 
     For example, the drawing pump  52  is configured by a vacuum pump, and is connected to the drawing passage  51   a  at a base end of the drawing member  51 . The drawing pump  52  can generate drawing force for drawing, into the drawing port  51   b  through the drawing passage  51   a,  the incompressible fluid that drips down from the blow nozzle  22 . 
     The drawing member moving unit  53  is configured by a cylinder with a guide. The drawing member moving unit  53  includes a cylinder body  53   a,  a piston rod  53   b  that makes advancing and retracting movements with respect to the cylinder body  53   a,  and a guide  53   c  that is fixed to an end of the piston rod  53   b.  The cylinder body  53   a  is fixed to the nozzle unit  20  using a fixing bracket  54 . 
     A holding plate  55  that is bent in an L-shape is fixed to the guide  53   c,  and the drawing member  51  is fixed to and held by the holding plate  55 . In a state in which the drawing member  51  is fixed to and held by the holding plate  55 , an end of the drawing member  51  is positioned away from the holding plate  55  on the front side (that is closer to the mold  10 ) in the advancing and retracting direction of the piston rod  53   b,  and the drawing port  51   b  faces a direction that is perpendicular to the advancing and retracting direction of the piston rod  53   b.    
     The drawing member moving unit  53  can cause the drawing member  51  to move from beside the blow nozzle  22  to its drawing position in which the drawing port  51   b  is positioned below the blow nozzle  22 , by causing the piston rod  53   b  to make an advancing movement to the front side with respect to the cylinder body  53   a.    
     Additionally, although in this embodiment the drawing member moving unit  53  is configured by a cylinder with a guide, the present disclosure is not limited to this example, and various configurations that allow the drawing member  51  to move can be used. Further, the drawing member moving unit  53  does not necessarily need to cause the drawing member  51  to move in a linear path and may cause it to move in a curved path. 
     Although an illustration is omitted, the blow molding apparatus  1  includes a preform feeding means for feeding the preform P to the mold  10 , and a conveyor means for removing a molded container from the mold  10  and conveying it to the subsequent step. As the preform feeding means and the conveyor means, for example, a guided cylinder including a holder for holding a preform or a container therein may be used. It is however also possible to use those with various configurations. Additionally, without using the preform feeding means and the conveyor means, an operator may manually perform the feeding of a preform or cap or the removal of a container. 
     Next, a procedure for blow molding the preform P into a container having a predetermined shape using the blow molding apparatus  1  having the above configuration will be described. 
     First, as illustrated in  FIG. 1 , in a state in which the nozzle unit  20  has been moved to its upper stroke end so that the blow nozzle  22  is in its standby position and in which the drawing member  51  has been withdrawn to beside the blow nozzle  22 , the preform P is placed in the mold  10 , and the mold  10  is closed. Additionally, in a state in which the preform P has been placed in the mold  10 , the drawing member  51  may be configured to be positioned below the blow nozzle  22  while the drawing pump  52  is being operated, until immediately before the blow nozzle  22  starts to move from its standby position to its connected position so as to be connected to the mouth tubular portion P 3  of the preform P. In this case, the drawing member  51  may be configured to move to beside the blow nozzle  22  thereafter. 
     Subsequently, as illustrated in  FIG. 4 , the blow nozzle  22  is moved downward to its connected position by the blow nozzle moving unit  40 , so that the blow nozzle  22  is connected to the mouth tubular portion P 3  of the preform P. 
     Subsequently, as illustrated in  FIG. 5 , the seal body  24  is raised so as to open the blow nozzle  22 , while the stretching rod  26  is lowered to thereby stretch the preform P in the longitudinal direction. A pressurized incompressible fluid is therefore supplied into the preform P from the pressurized fluid supply unit  30  through the blow nozzle  22  that is in its connected position. Thus, the preform P is subject to biaxial stretch blow molding and molded into a container C having a predetermined shape conforming to the shape of the cavity  11  of the mold  10 . 
     When blow molding is complete, the stretching rod  26  is raised, the blow nozzle  22  is closed by the seal body  24 , and the supply of the pressurized incompressible fluid from the pressurized fluid supply unit  30  to the blow nozzle  22  is stopped. Then, the blow nozzle  22  is driven upward by the blow nozzle moving unit  40 , so that the blow nozzle  22  is moved from its connected position to its standby position. 
     Subsequently, as illustrated in  FIG. 6  and  FIG. 7 , the drawing member  51  is moved forward toward a position below the blow nozzle  22  by the drawing member moving unit  53 , so that the drawing port  51   b  is positioned below the blow nozzle  22 . At this time, although the drawing port  51   b  may be disposed on the central axis of the blow nozzle  22 , the drawing port  51   b  is preferably disposed at a position a predetermined distance apart from the central axis of the blow nozzle  22  in the horizontal direction. In this case, the predetermined distance between the drawing port  51   b  and the central axis O of the blow nozzle  22  is appropriately changed in accordance with the drawing force generated in the drawing port  51   b,  the viscosity and amount of the incompressible fluid, or the like. Additionally, the drawing member  51  may start to move after the blow nozzle  22  has moved to its standby position, or may start to move while the blow nozzle  22  is moving from its connected position to its standby position. 
     Further, the drawing pump  52  is operated so as to apply drawing force to the drawing port  51   b.  Although it is preferable to operate the drawing pump  52  in advance before the drawing port  51   b  is positioned below the blow nozzle  22 , the drawing pump  52  may be operated after the drawing port  51   b  is positioned below the blow nozzle  22 . 
     After the molding of the container C and when the blow nozzle  22  is raised to its standby position, the incompressible fluid can drip down from the blow nozzle  22  to which it has adhered. In particular, in a case in which a relatively highly viscous liquid, such as shampoo or liquid detergent, is used as the incompressible fluid, it takes long for the dripping down of the incompressible fluid to start from the blow nozzle  22  after blow molding, and moreover, the incompressible fluid continues to run in a thin stream for a while. 
     In the blow molding apparatus  1  according to the present embodiment, however, after the container C has been molded and the blow nozzle  22  has been moved from its connected position to its standby position, the drawing port  51   b  of the drawing member  51 , which generates drawing force, is positioned below the blow nozzle  22 . Accordingly, even when the incompressible fluid adheres to the blow nozzle  22  during blow molding and drips down from the blow nozzle  22  when it is moved to its standby position, the dripped down incompressible fluid can be drawn into the drawing passage  51   a  of the drawing member  51  through the drawing port  51   b.  Thus, the dripping down onto the molded container C or the mold  10  can be prevented. 
     Thus, in the blow molding apparatus  1  according to the present embodiment, after the container C has been molded and the blow nozzle  22  has been moved from its connected position to its standby position, the drawing port  51   b  of the drawing member  51 , which generates drawing force, is positioned below the blow nozzle  22 . Accordingly, even when the incompressible fluid drips down from the blow nozzle  22  that is moved to its standby position, it is possible to prevent the dripped down incompressible fluid from adhering to the molded container C or the mold  10 . 
     Further, in the blow molding apparatus  1  according to the present embodiment, the drawing port  51   b  of the drawing member  51  is caused to open in the horizontal direction, and therefore, the incompressible fluid can be drawn into the drawing passage  51   a  of the drawing member  51  from the side when it is dripping down from the blow nozzle  22 . Thus, the incompressible fluid that drips down from the blow nozzle  22  can be drawn into the drawing passage  51   a  of the drawing member  51 , and at the same time, the incompressible fluid that drips down from the blow nozzle  22  can be prevented from adhering to the drawing member  51 . Accordingly, the adhesion of the incompressible fluid to the drawing member  51  can be prevented, so that the blow molding apparatus  1  will not be spoiled. 
     As described above, in the course of or after the drawing of the incompressible fluid that drips down from the blow nozzle  22  using the drawing member  51 , the mold  10  is opened, and the molded container C is removed and conveyed to the next step. Additionally, the blow molding apparatus  1  may be equipped with a cap fitting mechanism, and a cap may be fitted to the mouth tubular portion of the container C in a state in which the container C is placed in the mold  10 . 
       FIG. 8  illustrates a blow molding apparatus including a liquid receiving device according to a modification, and  FIG. 9  illustrates the blow molding apparatus in a state in which a drawing member has been moved so that a drawing port is positioned below a blow nozzle and a saucer has been moved to below the blow nozzle, after a container has been molded and the blow nozzle has been moved from its connected position to its standby position. Note that in  FIG. 8  and  FIG. 9  the same reference numerals are assigned to the members corresponding to those described above. 
     As illustrated in  FIG. 8 , the blow molding apparatus  1  according to the modification may be configured to include a liquid receiving device  60 , in addition to the drawing device  50 . The liquid receiving device  60  has a saucer  61  and a saucer moving unit  62 . 
     The saucer moving unit  62  is configured by a cylinder with a guide. The saucer moving unit  62  includes a cylinder body  62   a,  a piston rod  62   b  that makes advancing and retracting movements with respect to the cylinder body  62   a,  and a guide  62   c  fixed to an end of the piston rod  62   b.  The cylinder body  62   a  is fixed to the nozzle unit  20  using a fixing bracket  63 . 
     The saucer  61  is formed in a flat plate shape with a base end portion formed as an L-shape bent portion, at which the saucer  61  is fixed to the guide  62   c.    
     As illustrated in  FIG. 9 , the saucer moving unit  62  operates to move the saucer  61  to below the blow nozzle  22  on the lower side of the drawing member  51 , after the container C has been molded and the blow nozzle  22  has been moved from its inserted position to its standby position. In the present modification, the saucer moving unit  62  operates to move the saucer  61  to below the blow nozzle  22 , after the drawing member moving unit  53  has moved the drawing member  51  so that the drawing port  51   b  is positioned below the blow nozzle  22 . 
     Thus, since the blow molding apparatus  1  according to the modification includes the liquid receiving device  60 , in addition to the drawing device  50 , even when the incompressible fluid adheres to the blow nozzle  22  during blow molding and drips down from the blow nozzle  22  when it is moved to its standby position, the dripped down incompressible fluid can be drawn into the drawing passage  51   a  of the drawing member  51  through the drawing port  51   b.  Besides, the saucer  61  receives the incompressible fluid when it has dripped down after failing to be drawn by the drawing member  51 . In this way, the dripping down of the incompressible fluid onto the molded container C or the mold  10  can be prevented even more reliably. 
     Further, in the blow molding apparatus  1  according to the modification, after the drawing member moving unit  53  has moved the drawing member  51  so that the drawing port  51   b  is positioned below the blow nozzle  22 , the saucer moving unit  62  moves the saucer  61  to below the blow nozzle  22 . Accordingly, it is possible to ensure that the timing of the movement of the saucer  61  to below the blow nozzle  22  is after the dripping down of the incompressible fluid has been addressed at an early stage by the drawing member  51  drawing the incompressibility fluid that drips down from the blow nozzle  22 . For example, in a case in which the incompressible fluid that drips down from the blow nozzle  22  runs down in a thin stream extending from the blow nozzle  22  to the molded container C, the movement of the saucer  61  to below the blow nozzle  22  is timed to coincide with the incompressible fluid, which runs in the thin stream, having being drawn by the drawing member  51  and cut off. Thus, the incompressible fluid is prevented from adhering to a lower surface or the like of the saucer  61  and dripping down onto the molded container C or the mold  10 . 
       FIG. 10  is a sectional view illustrating a blow nozzle according to a modification. In  FIG. 10 , the same reference numerals are assigned to members corresponding to those described above. 
     As illustrated in  FIG. 10 , the blow nozzle  22  may be configured to include drawing holes  70  on its inner peripheral surface. In the present modification, the inner peripheral surface of the blow nozzle  22  is provided with a plurality of drawing holes  70  that is arranged at an interval in the circumferential direction and that is also arranged at an interval in the axial direction. 
     These drawing holes  70  are each connected to a drawing pump  72  via a flow passage  71  provided between the blow nozzle  22  and the body block  21 . The drawing pump  72  is configured by, for example, a vacuum pump, which can generate drawing force for drawing, into the respective drawing holes  70 , the incompressible fluid adhered to the blow nozzle  22 . 
     Additionally, the number or position of drawing holes  70  provided in the blow nozzle  22  can be appropriately changed. 
     In the illustrated example, the blow nozzle  22  is provided with a plurality of auxiliary drawing holes  73 , in addition to the plurality of drawing holes  70 . The plurality of auxiliary drawing holes  73  is open side by side at an interval from one another in the circumferential direction on a lower end surface of the nozzle body  22   a  of the blow nozzle  22 . Each auxiliary drawing hole  73  is connected to the drawing pump  72  through the flow passage  71 , as is the case with each drawing hole  70 . The drawing pump  72  can generate drawing force for drawing, into the respective drawing holes  70  and also into the respective auxiliary drawing holes  73 , the incompressible fluid adhered to the blow nozzle  22 . 
     Additionally, the number or position of auxiliary drawing holes  73  provided in the blow nozzle  22  can be changed in various ways. Further, the blow nozzle  22  may be configured to be provided only with the drawing holes  70  or the auxiliary drawing holes  73 . 
     According to the blow nozzle  22  of the modification that is configured as above, the incompressible fluid adhered to the blow nozzle  22  during blow molding can be drawn through the plurality of drawing holes  70  and auxiliary drawing holes  73 . It is therefore possible to reduce the amount of the incompressible fluid that drips down from the blow nozzle  22  when it is moved to its standby position. Thus, the incompressible fluid can be even more reliably prevented from dripping down from the blow nozzle  22  and adhering to the molded container C or the mold  10 , by ensuring that the incompressible fluid that drips down from the blow nozzle  22  when it is moved to its standby position can be drawn by the drawing member  51  of the drawing device  50 . 
     Needless to say, the present disclosure is not limited to the above embodiment, and various changes may be made without departing the gist of the present disclosure. 
     For example, although in the above embodiment the blow nozzle moving unit  40  is configured to move the nozzle unit  20  or the blow nozzle  22  upward with respect to the mold  10 , the present disclosure is not limited to this example. For example, the mold  10  may be configured to be moved downward with respect to the nozzle unit  20  or the blow nozzle  22 . Alternatively, the nozzle unit  20  or the blow nozzle  22 , and the mold  10  may be configured to be moved in a direction away from each other. 
     Further, the blow molding apparatus  1  may be configured without the liquid receiving device  60 , the drawing holes  70 , or the auxiliary drawing holes  73 . 
     Moreover, the blow molding apparatus  1  may be configured to perform a suck-back operation by which a predetermined amount of the incompressible fluid is sucked back from the inside of the molded container C toward the supply flow path  23 , by operating the pressurized fluid supply unit  30  in an opposite direction after blow molding and immediately before the seal body  24  is closed. 
     Moreover, although in the above embodiment the drawing device  50  and the liquid receiving device  60  are fixed to the nozzle unit  20 , the drawing device  50  and the liquid receiving device  60  may be fixed to a member or the like other than the nozzle unit  20 . 
     REFERENCE SIGNS LIST 
       1  Blow molding apparatus 
       10  Mold 
       11  Cavity 
       11   a  Opening 
       20  Nozzle unit 
       21  Body block 
       22  Blow nozzle 
       22   a  Nozzle body 
       22   b  Holding portion 
       23  Supply flow path 
       24  Seal body 
       25  Sealing claw portion 
       26  Stretching rod 
       30  Pressurized fluid supply unit 
       40  Blow nozzle moving unit 
       50  Drawing device 
       51  Drawing member 
       51   a  Drawing passage 
       51   b  Drawing port 
       52  Drawing pump 
       53  Drawing member moving unit 
       53   a  Cylinder body 
       53   b  Piston rod 
       53   c  Guide 
       54  Fixing bracket 
       55  Holding plate 
       60  Liquid receiving device 
       61  Saucer 
       62  Saucer moving unit 
       62   a  Cylinder body 
       62   b  Piston rod 
       62   c  Guide 
       70  Drawing hole 
       71  Flow passage 
       72  Drawing pump 
       73  Auxiliary drawing hole 
     P Preform 
     P 1  Body 
     P 2  Neck ring 
     P 3  Mouth tubular portion 
     P 4  Undercut portion 
     C Container 
     O Central axis