Patent Publication Number: US-2022219371-A1

Title: Blow molding apparatus and blow molding method

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a blow molding apparatus and a blow molding method. 
     Description of the Related Art 
     Conventionally, a hot parison type blow molding apparatus has been known as one of apparatuses for manufacturing a resin container. The hot parison type blow molding apparatus is configured to blow-mold a resin container using residual heat during injection molding of a preform, and is advantageous in that it is possible to manufacture a resin container which is diversified and excellent in aesthetic appearance as compared with a cold parison type. 
     Further, as a configuration of a blow molding apparatus, a rotary blow molding apparatus that blow-molds a resin container by intermittently conveying an injection-molded preform by a transport plate that is rotationally driven is well known (See, for example, Japanese Patent No. 4319863.). In this type of blow molding apparatus, an upper base that holds a transport plate and various drive mechanisms are fixed to a machine bed at intervals in the vertical direction. Then, in an injection molding part, a blow molding part, and the like of the blow molding apparatus, the transport plate moves up and down with respect to the upper base to perform processing of each step. 
     An axial length of the preform handled by the blow molding apparatus varies depending on the container to be manufactured. For example, when an axial length of the preform is short, the stroke of the transport plate in the vertical direction required to advance and retract the preform from each part of the blow molding apparatus can be shorter than that when the length is long. 
     However, in the configuration of the conventional blow molding apparatus, a stroke of the transport plate in the vertical direction is defined by interval between the position of the upper base and the machine bed, and is constant regardless of the type of the preform. That is, according to the conventional blow molding apparatus, when the axial length of the preform is short, the transport plate is reciprocated in the vertical direction more than the stroke required for advancing and retracting the preform. Therefore, depending on the type of preform, the operation time (dry cycle) of the machine becomes unnecessarily long, and thus the molding cycle of the container also becomes longer accordingly. 
     SUMMARY OF THE INVENTION 
     A blow molding apparatus according to one aspect of the present invention includes: an injection molding part configured to injection-mold a resin preform having a bottomed shape; a blow molding part configured to blow-mold the preform to manufacture a resin container; a machine bed; an upper base disposed at intervals in a vertical direction from the machine bed; a transport plate configured to rotate at a height position of the upper base to convey the preform between the injection molding part and the blow molding part; and an elevation mechanism configured to move the transport plate or the upper base up and down in the vertical direction with respect to a mold disposed on the machine bed. A support pillar includes a height adjusting part configured to adjust a stroke of the transport plate or the upper base in the vertical direction with respect to the machine bed. 
     Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view schematically illustrating a configuration of a blow molding apparatus. 
         FIG. 2  is a side view of the vicinity of an injection molding part of the blow molding apparatus. 
         FIG. 3  is a view illustrating a configuration example of a support pillar and a height adjusting part in a non-extended state. 
         FIG. 4  is a view illustrating a configuration example of the support pillar and the height adjusting part in a extended state. 
         FIGS. 5A and 5B  are views schematically illustrating a hydraulic cylinder and a guide mechanism of the height adjusting part. 
         FIGS. 6A to 6C  are views showing a configuration example of a stopper member and a spacer member. 
         FIG. 7  is a flowchart showing steps of a blow molding method. 
         FIG. 8  is a graph showing an example of temperature change of a preform in the blow molding method of the present embodiment and a comparative example. 
         FIG. 9  is a view schematically illustrating a configuration of an injection molding apparatus. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, embodiments of the present invention will be described with reference to the drawings. 
     In the embodiment, for easy understanding, structures and elements other than the main part of the present invention will be described in a simplified or omitted manner. In addition, in the drawings, the same elements are denoted by the same reference numerals. Note that the shapes, dimensions, and the like of the respective elements illustrated in the drawings are schematically illustrated, and do not indicate actual shapes, dimensions, and the like. 
     (Blow Molding Apparatus  1 ) 
       FIG. 1  is a plan view schematically illustrating a configuration of a blow molding apparatus  1  for manufacturing a resin container (Hereinafter, also referred to as a container.).  FIG. 2  is a side view of the vicinity of an injection molding part of the blow molding apparatus. 
     The blow molding apparatus  1  according to the present embodiment is a hot parison type (also referred to as a one-stage type) apparatus that performs blow molding by utilizing residual heat (internal heat quantity) during injection molding without cooling a preform  10  to room temperature. 
     As illustrated in  FIGS. 1 and 2 , the blow molding apparatus  1  includes a machine bed  2  and an upper base  3  disposed above the machine bed  2  (Z direction in the drawing). The upper base  3  is supported by a plurality of (four) support pillars  4  erected upward from the machine bed  2 . Each support pillar  4  includes a height adjusting part  5  that adjusts an interval in the vertical direction (Z direction in the drawing) between the machine bed  2  and the upper base  3 . 
     In the blow molding apparatus  1 , an injection molding part  11 , a temperature adjusting part  12 , a blow molding part  13 , and a take-out part  14  are arranged in a space between the machine bed  2  and the upper base  3 . The injection molding part  11 , the temperature adjusting part  12 , the blow molding part  13 , and the take-out part  14  are arranged at positions rotated by a predetermined angle (for example, 90 degrees) with respect to a rotation center O of a transport plate  15  described later. Note that, in the blow molding apparatus  1 , the temperature adjusting part  12  and the take-out part  14  may not be arranged. 
     Here, at the position of the injection molding part  11  of the upper base  3 , an upper mold clamping plate  27  of the injection molding part  11  and an injection core mold  23  illustrated in  FIG. 2  are arranged on the upper surface side. At the position of the temperature adjusting part  12  of the upper base  3 , a heating core and an elevation mechanism of the heating core (both not shown) are arranged on the upper surface side. At the position of the blow molding part  13  of the upper base  3 , a stretching rod and an elevation mechanism of the stretching rod (both not illustrated) are arranged on the upper surface side. In addition, at the position of the take-out part  14  of the upper base  3 , a take-out cam (not illustrated) is disposed on the upper surface side. 
     Further, four fan-shaped transport plates  15  are arranged at predetermined angles (for example, 90 degrees) on the lower surface of the upper base  3  above the machine bed  2 . The four transport plates  15  are guided by a plurality of receiving members  32  (see  FIG. 2 ) fixed around the upper base  3 , respectively, and intermittently circulate and move along a rotation direction with a rotation center O as a rotation axis. The preform  10  (or the container) held by the transport plate  15  is conveyed through the injection molding part  11 , the temperature adjusting part  12 , the blow molding part  13 , and the take-out part  14  in this order by the rotation of the transport plate  15 . Note that, the transport plate  15  may have a single disk shape and may not be divided for each molding part. 
     Further, as illustrated in  FIG. 2 , a neck mold  16  for holding the preform is provided on the lower surface of each transport plate  15  so that the axial direction of the preform  10  is along the vertical direction. An opening is formed on the upper surface side of the neck mold  16  in each transport plate  15 , and an injection core mold  23 , a blow core, the stretching rod, and the like can be inserted into the preform  10  from above through the opening. 
     (Injection Molding Part  11 ) 
     The injection molding part  11  includes an injection mold  21  and an elevation mechanism  30  of the transport plate  15 . An injection device  17  that supplies a resin material, which is a raw material of the preform, is connected to the injection molding part  11 . 
     The injection mold  21  includes an injection core mold  23  that defines the internal shape of the preform  10 , an injection cavity mold  24  that defines the external shape of the preform  10 , and a hot runner mold  25  that guides the molten resin supplied from the injection device  17  to a mold space of the injection mold  21 . The injection cavity mold  24  and the hot runner mold  25  are fixed to the lower base  2   a  side of the machine bed  2 . On the other hand, the injection core mold  23  is attached to the upper mold clamping plate  27  supported by tie bars  26 , and can move up and down in the vertical direction. 
     The elevation mechanism  30  has a function of moving the neck mold  16  attached to the lower surface of the transport plate  15  up and down with respect to the injection cavity mold  24 . The elevation mechanism  30  includes a lifting cylinder (not illustrated) that moves the receiving member  32  up and down in the vertical direction via a lifting rod  31 , and is configured such that the transport plate  15  held by the receiving member  32  moves up and down in the vertical direction by the up-and-down movement of the receiving member  32 . As a power source of the elevation mechanism  30 , for example, a hydraulic cylinder or an air cylinder can be used. Note that, as a power source of the elevation mechanism  30 , a hydraulic or toggle elevation mechanism or a ball screw mechanism by an electric motor may be used. 
     Here, the injection cavity mold  24  of the injection mold  21  is fixed to the lower base  2   a  side of the machine bed  2 , and the transport plate  15  rotates at the height position of the upper base  3  to convey the preform  10 . Therefore, the stroke of the transport plate  15  in the vertical direction by the elevation mechanism  30  when advancing and retracting the preform  10  with respect to the injection mold  21  is defined by the interval in the vertical direction between the machine bed  2  or the lower base  2   a  and the upper base  3 . 
     The injection molding part  11  closes the injection cavity mold  24 , the injection core mold  23 , and the neck mold  16  of the transport plate  15  to form a preform-shaped mold space. Then, by pouring the resin material from the injection device  17  into such a preform-shaped mold space, the preform  10  is manufactured by the injection molding part  11 . 
     Note that, also when mold opening of the injection molding part  11  is performed, the neck mold  16  of the transport plate  15  is not opened and directly holds and conveys the preform  10 . The number (That is, the number of containers that can be simultaneously molded by the blow molding apparatus  1 ) of the preforms  10  simultaneously molded by the injection molding part  11  can be appropriately set. As an example,  FIG. 1  illustrates a configuration in which four preforms are conveyed. 
     (Temperature Adjusting Part  12 ) 
     The temperature adjusting part  12  includes a mold unit (conditioning pot and conditioning rod) for temperature adjustment (not illustrated) and an elevation mechanism (not illustrated) of the mold unit. The temperature adjusting part  12  performs temperature equalization and removal of nonuniform temperature of the preform  10  manufactured by the injection molding part  11  using the conditioning pot, and adjusts the temperature of the preform  10  to a blow temperature (for example, about 90° C. to 105° C.) suitable for final blow. In addition, the temperature adjusting part  12  of the present embodiment also has a function of cooling the high temperature preform  10  after injection molding. Note that, the temperature adjusting part  12  may also include an elevation mechanism (not shown) of the transport plate  15  having the same configuration as the injection molding part  11 . 
     (Blow Molding Part  13 ) 
     The blow molding part  13  includes a blow-molding mold (a blow mold and a bottom mold), a stretching rod, a blow-air introducing member, and an elevation mechanism of the transport plate  15  (all not illustrated). The blow molding part  13  stretches the preform  10  disposed in the blow-molding mold in the axial direction with a stretching rod, and introduces high-pressure air into the preform to perform biaxial stretching blow molding, thereby manufacturing a container. 
     (Take-Out Part  14 ) 
     The take-out part  14  opens the neck mold  16  with the take-out cam, and takes out the container manufactured by the blow molding part  13  from the blow molding apparatus  1 . The container taken out by the take-out part  14  is boxed or conveyed to the filling line. Note that, the take-out part  14  may also include an elevation mechanism (not illustrated) of the transport plate  15  having the same configuration as the injection molding part  11 . 
     (Support Pillar  4 , Height Adjusting Part  5 ) 
       FIG. 3  is a diagram illustrating a configuration example of the support pillar  4  and the height adjusting part  5  in the non-extended state.  FIG. 4  is a diagram illustrating a configuration example of the support pillar  4  and the height adjusting part  5  in the extended state.  FIGS. 5A and 5B  are diagrams schematically illustrating a hydraulic cylinder and a guide part of the height adjusting part. 
     Note that, since the configurations of the four pairs of support pillars  4  and the height adjusting parts  5  in the present embodiment are common, the configuration of one pair of support pillar  4  and the height adjusting part  5  will be described, and redundant description will be omitted. 
     As illustrated in  FIGS. 3 and 4 , each of the support pillars  4  includes an upper support pillar  41  and a lower support pillar  42  arranged along the vertical direction. The upper support pillar  41  is connected to the lower side of the upper base  3 , and has a pedestal  41   a  protruding laterally at the lower end side. The lower support pillar  42  is erected on the machine bed  2 . The upper support pillar  41  and the lower support pillar  42  are connected in the vertical direction by a cylinder rod  51   b  and a guide part  52  described later. In the non-extended state shown in  FIGS. 3 and 5A , the upper end surface of the lower support pillar  42  is configured to receive the lower end surface of the upper support pillar  41 . 
     The height adjusting part  5  includes a hydraulic cylinder  51  as an example of a drive part, a guide part  52  that guides the upper support pillar  41  in the vertical direction, and a locking part  53  that fixes the position of the upper support pillar  41  in the vertical direction. 
     The hydraulic cylinder  51  includes a cylinder body  51   a  fixed inside the upper support pillar  41  and a cylinder rod  51   b  extending below the cylinder body  51   a.  As shown in  FIGS. 5A and 5B , the cylinder rod  51   b  is connected to the upper end surface of the lower support pillar  42 , and expands and contracts in the vertical direction by the hydraulic pressure of the cylinder body  51   a.  Therefore, the upper support pillar  41  can be moved in the vertical direction by the hydraulic cylinder  51 . 
     As shown in  FIGS. 5A and 5B , the guide part  52  is disposed on one side surface of the upper support pillar  41  and the lower support pillar  42 . In addition, as illustrated in  FIGS. 3 and 4 , the locking part  53  is disposed on another side surface of the upper support pillar  41  and the lower support pillar  42  different from the side surface on which the guide part  52  is disposed. 
     The guide part  52  includes a guide rod  52   a  disposed along the vertical direction. The guide rod  52   a  is fixed to the pedestal  41   a  of the upper support pillar  41  and is attached so as to penetrate a guide block  42   a  fixed to the lower support pillar  42 . The guide rod  52   a  is slidable with respect to the guide block  42   a.  Therefore, the movement of the upper support pillar  41  in the horizontal direction (XY direction in the drawing) is restricted by the guide rod  52   a,  and the upper support pillar  41  is stably movable only in the vertical direction. 
     In the extended state shown in  FIGS. 4 and 5B , a spacer member  54  that defines an interval in the vertical direction between the machine bed  2  and the upper base  3  is inserted between the upper end surface of the lower support pillar  42  and the lower end surface of the upper support pillar  41 . As shown in  FIG. 6C , the spacer member  54  is a block having a rectangular shape overall, and a groove portion  54   a  extending in the vertical direction is formed on one side surface portion. The width of the groove portion  54   a  of the spacer member  54  is set larger than the diameter of the cylinder rod  51   b.    
     Note that, for the spacer member  54 , a member having an arbitrary height h can be selected from a plurality of types having different heights in the vertical direction so that the stroke of the transport plate  15  in the vertical direction has an appropriate dimension for advancing and retracting the preform  10 . 
     When the spacer member  54  is attached, the spacer member  54  is horizontally inserted into a gap between the upper support pillar  41  and the lower support pillar  42  formed by the operation of the hydraulic cylinder  51 , and the spacer member  54  is disposed such that the cylinder rod  51   b  is sandwiched between the groove portions  54   a.  By disposing the spacer member  54  between the upper support pillar  41  and the lower support pillar  42 , the interval in the vertical direction between the machine bed  2  and the upper base  3  can be adjusted by the height h of the spacer member  54 . 
     The locking part  53  includes a lock cylinder  55  and a stopper member  56 . 
     The lock cylinder  55  is fixed to a support base  57  so as to face the second side surface of the upper support pillar, and expands and contracts a rod  55   a  serving as a stopper in the horizontal direction toward the side surface of the upper support pillar  41 . In a state in which the rod  55   a  of the lock cylinder  55  is expanded, the position of the upper support pillar  41  in the vertical direction is fixed by the rod  55   a  being engaged with the stopper member  56 . On the other hand, in a state where the rod  55   a  is contracted, the engagement between the rod  55   a  and the stopper member  56  is released, and the upper support pillar  41  can be moved in the vertical direction. 
     The stopper member  56  is a member that is attached to an attachment portion  41   b  provided on a side surface of the upper support pillar  41  and receives the rod  55   a  of the lock cylinder  55 . The stopper member  56  is a flat plate-shaped member, and has bolt holes opened in the thickness direction. In addition, the stopper member  56  receives the rod  55   a  of the lock cylinder  55  on the upper surface. 
     The stopper member  56  is exchangeably attached to the second side surface of the upper support pillar with a bolt (not illustrated) by selecting a member having an arbitrary height from a plurality of types having different heights in the vertical direction. For example,  FIG. 6A  is a view illustrating a stopper member  56   a  corresponding to the non-extended state in  FIG. 3 , and  FIG. 6B  is a view illustrating a stopper member  56   b  corresponding to the extended state in  FIG. 4 . 
     As illustrated in  FIGS. 3 and 4 , while the position of the lock cylinder  55  in the vertical direction is fixed by the support base  57 , the position of the attachment portion  41   b  of the upper support pillar  41  changes in the vertical direction between the extended state and the non-extended state. Therefore, the dimension h 2  in the vertical direction of the stopper member  56   b  corresponding to the extended state is set shorter by the height h of the spacer member  54  than the dimension h 1  in the vertical direction of the stopper member  56   a  corresponding to the non-extended state. As a result, the upper surface of the stopper member  56  can be aligned with the position of the lock cylinder  55  in both the extended state and the non-extended state. 
     When attached to the upper support pillar  41 , the upper surface of the stopper member  56  forms a wedge-shaped inclined surface that is inclined downward with distance from the side surface of the upper support pillar. As illustrated in  FIGS. 3 and 4 , when the rod  55   a  of the lock cylinder  55  stretches, the inclined surface of the stopper member  56  is pressed downward, while the stopper member  56  fixed to the upper support pillar  41  generates an upward reaction force, so that the upper support pillar  41  is strongly fixed. 
     &lt;Description of Blow Molding Method&gt; 
       FIG. 7  is a flowchart illustrating steps of a blow molding method performed by the blow molding apparatus  1  according to the present embodiment. In the present embodiment, before each step (S 101  to S 104 ) to be described later of the blow molding method is performed, a height adjusting step (S 100 ) of adjusting the interval in the vertical direction between the machine bed  2  and the upper base  3  is performed. 
     (Step S 100 : Height adjusting step) 
     The height adjusting step is a step of adjusting the interval in the vertical direction between the machine bed  2  and the upper base  3  according to the axial length of the preform  10  used for blow molding. In the following description, assuming a case where the preform  10  is switched from a preform having a long axial length to a preform having a short axial length, a case where the blow molding apparatus  1  is adjusted from the extended state illustrated in  FIG. 4  to the non-extended state illustrated in  FIG. 3  will be described. 
     First, the rod  55   a  of the lock cylinder  55  is contracted to release the fixation of the upper support pillar  41 , and then the cylinder rod  51   b  of the hydraulic cylinder  51  is slightly expanded. As a result, the upper support pillar  41  moves upward with respect to the lower support pillar  42 , and the spacer member  54  sandwiched between the upper support pillar  41  and the lower support pillar  42  can be removed. 
     Secondly, the spacer member  54  is removed from between the upper support pillar  41  and the lower support pillar  42 . Further, the stopper member  56   b  attached to the upper support pillar  41  is replaced with a stopper member  56   a  corresponding to the non-extended state. 
     Third, the cylinder rod  51   b  of the hydraulic cylinder  51  is contracted to bring the lower end surface of the upper support pillar  41  and the upper end surface of the lower support pillar  42  into contact with each other, thereby bringing the support pillar  4  into a non-extended state. As a result, the interval in the vertical direction between the machine bed  2  and the upper base  3  is shortened by the height h of the removed spacer member  54 . The stroke of the transport plate in the vertical direction is adjusted to a dimension suitable for advancing and retracting the preform having a short axial length. 
     Fourth, the rod  55   a  of the lock cylinder  55  is stretched to be engaged with the stopper member  56   a.  As a result, the position of the upper support pillar  41  in the vertical direction is fixed. 
     As described above, in the height adjusting step, the interval in the vertical direction between the machine bed  2  and the upper base  3  can be adjusted. The above example is merely an example, and in the height adjusting step, the height adjusting part  5  may be adjusted from the non-extended state to the extended state. Alternatively, the height adjustment may be performed by replacing the spacer member  54  with a different member so that the stroke of the transport plate  15  in the vertical direction has an appropriate dimension for advancing and retracting the switched preform. 
     When the height adjusting step is completed, each step of the blow molding method described below is performed. 
     (Step S 101 : Injection Molding Step) 
     First, in the injection molding part  11 , a resin is injected from the injection device  17  into a preform-shaped mold space formed by the injection cavity mold  24 , the injection core mold  23 , and the neck mold  16  of the transport plate  15  to manufacture the preform  10 . 
     In step S 101 , mold opening of the injection molding part  11  is performed immediately after the completion of the resin filling or after the minimum cooling time provided after the resin filling. That is, the preform  10  is released from the injection cavity mold  24  and the injection core mold  23  in a high temperature state in which the outer shape of the preform  10  can be maintained. Thereafter, the transport plate  15  rotates by a predetermined angle, and the preform  10  held by the neck mold  16  is conveyed to the temperature adjusting part  12 . 
     Here, a temperature change of the preform  10  in the blow molding method of the present embodiment will be described with reference to  FIG. 8 . The vertical axis in  FIG. 8  represents the temperature of the preform  10 , and the horizontal axis in  FIG. 8  represents time. In  FIG. 8 , an example of temperature change of the preform of the present embodiment is illustrated in (A) of  FIG. 8 . An example of temperature change of the preform of comparative example (conventional method) described later is shown in (B) of  FIG. 8 . The blank between the respective steps is the time required to transport the preform  10  or the container, and is the same. 
     In the present embodiment, when the resin material is injection-molded at a temperature equal to or higher than the melting point of the resin material, only minimum cooling of the preform  10  after injection molding is performed in the injection molding part  11 , and cooling and temperature adjustment of the preform  10  are performed in the temperature adjusting part  12 . In the present embodiment, the time (cooling time) for cooling the resin material after completion of injection of the resin material in the injection molding part  11  is preferably ½ or less with respect to the time (injection time) for injecting the resin material. The time for cooling the resin material can be made shorter than the time for injecting the resin material depending on the weight of the resin material. The time for cooling the resin material is more preferably ⅖ or less, still more preferably ¼ or less, and particularly preferably ⅕ or less with respect to the time for injecting the resin material. Since the cooling time is significantly shortened as compared with the comparative example, the skin layer (surface layer in a solidified state) of the preform is formed to be thinner than before, and the core layer (inner layer in a softened or molten state) is formed to be thicker than before. That is, as compared with the comparative example, a preform having a large thermal gradient between the skin layer and the core layer and having high residual heat at a high temperature is formed. 
     In the present embodiment, the injection-molded preform  10  is released from the injection molding part  11  at a higher release temperature than in the comparative example, and is conveyed to the temperature adjusting part  12 . With the movement to the temperature adjusting part  12 , the temperature of the preform  10  is equalized by heat exchange (heat conduction) between the skin layer and the core layer. Further, the preform  10  is slightly cooled from the outer surface by the contact with the outside air. However, the temperature of the preform  10  is maintained at a substantially high release temperature until the preform is carried into the temperature adjusting part  12 . In the temperature adjusting part  12 , the temperature of the preform  10  is lowered from the high release temperature to the blow temperature, and then the temperature of the preform  10  is maintained at the blow temperature until blow molding is performed. 
     Here, due to the structure of the blow molding apparatus  1 , the standby times of an injection molding step, a temperature adjusting step, a blow molding step, and a container take-out step are the same. Similarly, the conveyance time between the respective steps is the same. 
     The conveyance time between the respective steps includes a time for reciprocating the transport plate  15  in the vertical direction. In the present embodiment, the stroke of the transport plate  15  in the vertical direction is adjusted in advance to a dimension suitable for advancing and retracting the preform by the height adjusting step. Therefore, in the present embodiment, when the transport plate  15  is reciprocated in the vertical direction, the transport plate  15  does not need to be moved excessively. 
     On the other hand, as a comparative example, an example of temperature change of the preform ((B) of  FIG. 8 ) when the preform  10  is cooled in the injection molding step will be described. 
     In the comparative example, the preform  10  is cooled to a temperature lower than or substantially equal to the blow temperature in the mold of the injection molding part  11 . As a result, in the comparative example, the time of the injection molding step is longer than that in the present embodiment. Then, since the time of each step is set in accordance with the time of the longest injection molding step, the time of the molding cycle of the container becomes long as a result. 
     (Step S 102 : Temperature Adjusting Step) 
     Subsequently, the temperature adjusting part  12  performs temperature adjustment for bringing the temperature of the preform  10  close to a temperature suitable for the final blow. 
     In the temperature adjusting step, first, the preform  10  is accommodated in the preform-shaped conditioning space in the conditioning pot. Subsequently, a heating core capable of blowing air is introduced into the preform  10  accommodated in the conditioning pot, and cooling blow of the preform  10  is performed. 
     By the cooling blow in the temperature adjusting step, the preform  10  receives air pressure from the inside and continues to come into contact with the conditioning pot kept at a predetermined temperature. Therefore, in the temperature adjusting step, the temperature of the preform  10  is adjusted so as not to be equal to or lower than the blow temperature from the outside, and the nonuniform temperature generated during the injection molding is also reduced. Note that, since the conditioning pot has a preform-shaped space, the shape of the preform is maintained in the conditioning pot and does not greatly change. 
     After the temperature adjusting step, the transport plate  15  rotates by a predetermined angle, and the preform  10  after the temperature adjustment held in the neck mold  16  is conveyed to the blow molding part  13 . 
     (Step S 103 : Blow Molding Step) 
     Subsequently, the blow molding of the container is performed in the blow molding part  13 . 
     First, when the preform  10  is accommodated in the blow molding mold of the blow molding part  13 , the blow molding mold is closed, and a mold space corresponding to the shape of the container is formed. Subsequently, a blow air introduction member (blow core) and a stretching rod are inserted into the preform  10 , and the preform  10  is stretched in the axial direction by lowering of the stretching rod. Thereafter, the blow air is introduced into the preform  10  from the opening of the blow air introduction member. As a result, the preform  10  bulges so as to be in close contact with the blow molding mold and is blow-molded to a container. 
     (Step S 104 : Container Take-Out Step) 
     When the blow molding is completed, the blow molding mold is opened. Subsequently, the transport plate  15  rotates by a predetermined angle, and the container is conveyed to the take-out part  14 . In the take-out part  14 , the neck portion of the container is released from the neck mold  16 , and the container is taken out to the outside of the blow molding apparatus  1 . 
     Thus, the series of steps of the blow molding method is completed. Thereafter, by rotating the transport plate  15  by a predetermined angle, the respective steps of S 101  to S 104  described above are repeated. 
     Hereinafter, effects of the present embodiment will be described. 
     According to the blow molding apparatus  1  of the present embodiment, the interval in the vertical direction between the machine bed  2  and the upper base  3  can be adjusted by the height adjusting part  5  of the support pillar  4 . By adjusting the interval in the vertical direction between the machine bed  2  and the upper base  3  according to the axial length of the preform  10  used for the blow molding, the stroke of the transport plate in the vertical direction when the preform is conveyed in each step of the blow molding becomes an appropriate dimension for advancing and retracting the preform. 
     The conveyance time between the respective steps of the blow molding includes a time for reciprocating the transport plate  15  in the vertical direction, and the longer the time, the longer the molding cycle of the container in the blow molding. When the interval in the vertical direction between the machine bed  2  and the upper base  3  is individually adjusted according to the axial length of the preform  10  as described above, the transport plate  15  does not need to be moved excessively when the transport plate  15  is reciprocated in the vertical direction, and the operation time of the machine and the molding cycle of the container are optimized. 
     In other words, according to the present embodiment, as compared with the case where the same preform  10  is used but the height adjustment is not performed, the time for reciprocating the transport plate  15  in the vertical direction is shortened, so that the molding cycle of the container can be speeded up. 
     Further, in the present embodiment, the position of the upper base  3  with respect to the machine bed  2  is fixed at the time of blow molding, and the transport plate  15  holding the preform  10  moves up and down in the vertical direction. As described above, in the present embodiment, the heavy upper base  3  supporting various components such as the injection core mold  23  and the stretching rod, and these drive mechanisms do not need to be moved up and down at the time of blow molding. That is, according to the configuration of the present embodiment, the load during the operation is reduced as compared with the configuration in which the upper base  3  is moved up and down during the blow molding, so that the power consumption of the blow molding apparatus  1  can be significantly suppressed. In addition, it is easy to stabilize the operation of the blow molding apparatus  1 , and it is possible to easily cope with the speed-up of the molding cycle of the container. 
     The present invention is not limited to the above embodiments, and various improvements and design changes may be made without departing from the gist of the present invention. 
     For example, an air cylinder, a toggle elevation mechanism, a ball screw mechanism by an electric motor, or the like may be used as the drive part of the height adjusting part  5 . 
     For example, the drive part of the height adjusting part  5  does not need to be provided in all the height adjusting parts. For example, in a range in which the upper base  3  can be stably moved in the vertical direction, a height adjusting part having no drive part may be disposed in some of the support pillars  4 . 
     In addition, the position of the height adjusting part  5  in the blow molding apparatus  1  is not limited to the configuration of the above embodiment. For example, the height adjusting part  5  may be provided on the lower surface of the upper base  3 . 
     In the above embodiment, the configuration example of the blow molding apparatus in which the upper base is supported by the plurality of support pillars erected on the machine bed and the transport plate moves up and down with respect to the machine bed has been described. However, in the present invention, in the blow molding apparatus in which the upper base holding the transport plate is moved up and down with respect to the machine bed by the lifting apparatus, the stroke of the upper base in the vertical direction with respect to the machine bed may be adjusted by the spacer. 
     The configuration of the height adjusting part  5  of the above embodiment is not limited to application to a hot parison type blow molding apparatus. For example, the height adjusting part  5  of the above embodiment may be applied to an injection molding apparatus used for manufacturing the preform  10  at a high speed. 
       FIG. 9  is a diagram schematically illustrating a configuration of an injection molding apparatus  60 . The injection molding apparatus  60  in  FIG. 9  is a apparatus used for manufacturing the preform  10  at a high speed, and corresponds to the blow molding apparatus  1  of the above embodiment excluding the blow molding part  13 . Therefore, in the description of  FIG. 9 , the same components as those of the above embodiment are denoted by the same reference numerals, and redundant description is omitted. 
     The injection molding apparatus  60  includes a machine bed  2  and an upper base  3  disposed above the machine bed  2 . The interval in the vertical direction (the direction perpendicular to the paper surface of  FIG. 9 ) between the machine bed  2  and the upper base  3  can be adjusted by the height adjusting part  5 . Further, the injection molding apparatus  60  includes an injection molding part  11 , a post cooling part  61 , a take-out part  14 , and a transport plate  15  in a space between the machine bed  2  and the upper base  3 . The post cooling part  61  has a configuration capable of cooling the preform in a short time to such an extent that the preform  10  can be discharged in a cured state by the take-out part  14 , and is a kind of the temperature adjusting part  12  in a broad sense. 
     The injection molding part  11 , the post cooling part  61 , and the take-out part  14  are arranged at positions rotated by a predetermined angle (for example, 120 degrees) in the circumferential direction of the transport plate  15 . The configuration of the transport plate  15  is the same as that of the above embodiment except that the rotation angle is different for each step. 
     In the injection molding apparatus  60 , the preform  10  held by the neck mold  16  is conveyed through the injection molding part  11 , the post cooling part  61 , and the take-out part  14  in this order by the rotation of the transport plate  15 . 
     In the injection molding apparatus  60 , the post cooling part  61  is provided on the downstream side of the injection molding part  11 , so that the post cooling part  61  can additionally cool the preform  10 . By additionally cooling the preform  10  by the post cooling part  61 , the preform  10  can be released from the injection molding part  11  even in a high temperature state as in the above-described embodiment, and the cooling time of the preform  10  in the injection molding part  11  can be significantly shortened. As a result, since the molding of the next preform  10  can be started early, the molding cycle time of the preform  10  in the injection molding apparatus  60  can be shortened. 
     Further, according to the injection molding apparatus  60 , the stroke of the transport plate  15  in the vertical direction can be set to an appropriate dimension for advancing and retracting the preform by adjusting the interval in the vertical direction between the machine bed  2  and the upper base  3  by the height adjusting part  5 . As a result, the time for reciprocating the transport plate  15  in the vertical direction is shortened, so that the molding cycle of the preform  10  can be speeded up. 
     It should be considered that the embodiment disclosed herein is illustrative in all respects and not restrictive. The scope of the present invention is indicated not by the above description but by the claims, and it is intended that meanings equivalent to the claims and all modifications within the scope are included.