JP2016168801A - Blow molding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blow molding device capable of preventing a non-compressive fluid from dropping from a nozzle and adhering to a container and a mold after molding, when the nozzle is detached from a mouth part after blow molding.SOLUTION: A blow molding device 1 comprises: a mold 11; a nozzle 15 inserted into a mouth part 3 of a preform 2; a pressurized fluid supply part 18 for supplying a pressurized non-compressive fluid to the nozzle 15; and a seal body 20 for opening and closing the nozzle 15. The seal body 20 comprises: a seal body main body part 20a for contacting an upper end of the nozzle 15 when the seal body 20 is at a close position; and an extension part 20b disposed in the nozzle 15 with a slight gap to an inner peripheral face of the nozzle 15 when the seal body 20 is at the close position. When the seal body 20 is at the close position, a lower end of the extension part 20b is in proximity to a lower end face of the nozzle 15.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a blow molding apparatus that blow-molds a resin preform into a container having a predetermined shape, and particularly relates to a device that uses an incompressible fluid such as a liquid as a pressurized fluid for performing blow molding.

  Resin containers such as polypropylene (PP) housings and polyethylene terephthalate (PET) housings (pet bottles) are used for various beverages, cosmetics, medicines, detergents, toiletries such as shampoos, etc. Used to contain contents. In such a container, a resin preform formed into a bottomed cylindrical shape by injection molding or the like is heated to a temperature at which a stretching effect can be exhibited, and in this state, a biaxial is formed using a blow molding device. In general, it is formed into a predetermined shape by stretch blow molding.

  As a blow molding apparatus, an apparatus that uses an incompressible fluid such as a pressurized liquid instead of pressurized air is known as a pressurized fluid supplied into a preform. In this case, by using the contents that are finally filled in the container as a product such as a beverage as the pressurizing fluid, the filling process of the contents into the container is omitted, and the production process and the blow molding device The configuration can be simplified.

  For example, Patent Document 1 discloses a blow molding die on which a preform heated to a temperature at which stretching can be performed, a nozzle inserted into a mouth portion of the preform attached to the die, and through the nozzle. A pressurized fluid supply unit that supplies pressurized liquid to the preform and a stretching rod that is movable in the vertical direction are added to the preform while the preform is stretched in the longitudinal direction (axial direction) by the stretching rod. A blow molding apparatus is described in which a pressurized liquid is supplied and the preform is stretched in the lateral direction (radial direction) to form the preform into a container having a shape along the cavity of the mold. .

JP2013-208834A

  In the conventional blow molding apparatus as shown in Patent Document 1, when the nozzle is raised after blow molding and the nozzle is detached from the mouth of the container, the liquid adhering to the surface of the nozzle or the surface of the stretching rod (Incompressible fluid) may sag downward. In particular, when a relatively high-viscosity liquid such as shampoo or liquid detergent is used as an incompressible fluid for blow molding, it takes a long time for the liquid to drip from the nozzle after blow molding. However, since the liquid keeps dripping for a while so as to pull the yarn, the liquid drops on the molded container and the mold after the container is taken out, which causes a problem of contamination.

  The present invention has been made in view of such a problem, and the object thereof is to form a container after molding because an incompressible fluid drips from the nozzle when the nozzle is detached from the mouth after blow molding. Another object of the present invention is to provide a blow molding apparatus capable of preventing adhesion to a metal mold.

  The blow molding apparatus of the present invention is a blow molding apparatus for blow molding a resin preform into a container having a predetermined shape, and a blow molding die in which the preform is disposed, and the preform from the lower end side. A cylindrical nozzle to be inserted into the mouth, a pressurized fluid supply part for supplying pressurized incompressible fluid to a supply flow path connected to the nozzle from the upper end side, and an upper end of the nozzle A sealing body that is movable between a closed position that closes the nozzle and an open position that opens the nozzle away from the upper end of the nozzle, and the sealing body is in the closed position. A seal body main body that is in contact with the upper end of the nozzle, and a slight gap with respect to the inner peripheral surface of the nozzle when the seal body is in a closed position and protrudes downward from the seal body main body. Open the nozzle And a extension portion disposed, the seal body characterized in that the lower end of said extension portion when in the closed position is close to the lower end surface of the nozzle.

  The blow molding apparatus of the present invention has the above-described configuration, wherein a plurality of suction holes provided side by side in the axial direction of the nozzle on the inner peripheral surface of the nozzle, and a plurality of suction holes extending in the axial direction are provided in the nozzle. A suction hole that connects the suction holes to each other, and a suction pump that is connected to the vertical hole via a suction path and applies suction force to suck the incompressible fluid adhering to the nozzle to the plurality of suction holes. It is preferable to have further.

  The blow molding apparatus of the present invention has the above-described configuration, wherein the preform is provided at the axial center of the seal body so as to be relatively movable in the axial direction with respect to the seal body, and moves downward when blow molding. The stretching rod includes a stretching rod that extends in the axial direction, and the stretching rod has a lower end that coincides with a lower end of the sealing body when the sealing body is in a closed position after the preform is stretched. It is preferable that it rises to a position and rises in synchronism with the seal body when the seal body rises with the nozzle relative to the mouth.

  In the blow molding apparatus of the present invention, in the above configuration, the viscosity of the incompressible fluid when supplied to the preform is preferably 10,000 mPa · s or less.

  According to the present invention, there is provided a blow molding apparatus capable of preventing an incompressible fluid from dripping from the nozzle and adhering to a molded container or mold when the nozzle is detached from the mouth after blow molding. Can be provided.

It is sectional drawing which expands and shows the principal part of the blow molding apparatus which is one embodiment of this invention. It is a longitudinal cross-sectional view of the nozzle shown in FIG. It is a bottom view of the nozzle shown in FIG. It is sectional drawing at the time of blow molding of the blow molding apparatus shown in FIG. It is sectional drawing when a sealing body is closed after blow molding of the blow molding apparatus shown in FIG. It is sectional drawing when a nozzle detaches | leaves from an opening | mouth part after blow molding of the blow molding apparatus shown in FIG.

  Hereinafter, the present invention will be described in more detail with reference to the drawings.

  A blow molding apparatus 1 according to an embodiment of the present invention shown in FIG. 1 blows a resin preform 2 into a container having a predetermined shape, and is a blow molding gold on which the preform 2 is disposed. A mold 11 is provided. Although only a part is shown in the drawing, the cavity 12 of the mold 11 has a bowl shape and opens upward on the upper surface of the mold 11. The preform 2 is mounted on the mold 11 in an upright posture with the mouth portion 3 as an upper side, and the mouth portion 3 projects upward from the cavity 12. Although details are not shown, the mold 11 can be opened left and right, and the molded container can be taken out from the mold 11 by opening the mold 11.

  As the preform 2, for example, a thermoplastic resin material that exhibits stretchability by heating, such as polypropylene (PP), polyethylene terephthalate (PET), polyethylene (PE), etc., is bottomed by injection molding, compression molding, extrusion molding, or the like. What was formed in the cylinder shape can be used.

  A nozzle unit 13 is provided on the upper side of the mold 11 so as to be movable relative to the mold 11 in the vertical direction. The nozzle unit 13 has a main body block 14. In the illustrated case, the main body block 14 is configured by combining a plurality of members, but a detailed description thereof will be omitted.

  The nozzle unit 13 is provided with a cylindrical nozzle 15. The nozzle 15 has a nozzle body 15a formed in a cylindrical shape whose outer diameter is smaller than the inner diameter of the mouth portion 3 of the preform 2, and a large-diameter clamping portion 15b integrally provided on the upper side of the nozzle body 15a. And is clamped and fixed to the inner surface of the main body block 14 at the clamping portion 15b. The nozzle 15 can be formed of, for example, a steel material or a resin material.

  The nozzle 15 is arranged coaxially with the cavity 12 of the mold 11, and when the nozzle unit 13 is lowered to a predetermined position, the nozzle body 15 a is opened from the lower end side of the preform 2 attached to the mold 11. To be inserted.

  A supply channel 16 extending in the vertical direction is provided inside the main body block 14, and the supply channel 16 is connected to the nozzle 15 from the upper end side. In addition, a pressurized fluid supply unit 18 is connected to the supply channel 16 via a pipe 17. The pressurized fluid supply unit 18 can supply the incompressible fluid pressurized to a predetermined pressure to the supply channel 16 through the pipe 17. That is, the pressurized fluid supply unit 18 can supply the incompressible fluid pressurized to the preform 2 through the pipe 17, the supply channel 16, and the nozzle 15 at the time of blow molding.

  As the pressurized fluid supply unit 18, for example, a configuration using a plunger pump as a pressurizing source is preferably used, but an incompressible fluid pressurized to a predetermined pressure is supplied to the supply channel 16. Other configurations can be used as long as they can be used.

  As the incompressible fluid that the pressurized fluid supply unit 18 supplies to the supply channel 16, that is, the preform 2, for example, a relatively viscous liquid such as a shampoo or a liquid detergent can be used. In this case, the incompressible fluid preferably has a viscosity of 10,000 mPa · s or less when supplied to the preform 2.

  Inside the supply channel 16, a seal body 20 for opening and closing the nozzle 15 is disposed so as to be movable in the vertical direction. As shown in the figure, this seal body 20 includes, for example, a cylindrical rod-shaped seal body main body portion 20a extending along the axis of the supply flow path 16 and an extension portion projecting downward from the lower end of the seal body main body portion 20a. 20b can be provided integrally.

  The upper end of the nozzle 15, that is, the upper surface of the clamping portion 15 b of the nozzle 15 is a tapered closing surface 15 c, and the seal body 20 moves to the closed position where it becomes the lower stroke end to the lower end of the seal body main body portion 20 a. When the provided tapered surface 20c abuts against the closing surface 15c, the communication between the supply flow channel 16 and the nozzle body 15a is blocked by the seal body 20 so that the nozzle 15 is closed. On the other hand, when the seal body 20 moves upward from the closed position to the open position, the tapered surface 20 c is separated from the closing surface 15 c of the nozzle 15, and the nozzle 15 is opened to communicate with the supply flow path 16.

  Accordingly, the nozzle body 15a is inserted into the mouth 3 of the preform 2 arranged in the mold 11, and the pressurized fluid supply unit 18 is opened by the seal body 20 in a state where the pressurized fluid supply unit 18 is activated, thereby supplying pressurized fluid. The preform 2 can be blow-molded by supplying a pressurized incompressible fluid from the portion 18 through the nozzle 15 to the inside of the preform 2. Moreover, the supply of the incompressible fluid to the container after molding can be stopped by closing the nozzle 15 with the seal body 20 after blow molding.

  The extension 20b of the seal body 20 is formed in a cylindrical shape having an outer diameter slightly smaller than the inner diameter of the nozzle body 15a. When the seal body 20 is in the closed position, the extension 20b is formed on the inner peripheral surface of the nozzle body 15a. In contrast, the nozzle body 15a is arranged inside the nozzle body 15a with a slight gap. When the seal body 20 is in the closed position, the lower end of the extension portion 15b is close to the lower end surface of the nozzle body 15a. In the illustrated case, when the seal body 20 is in the closed position, the lower end of the extension portion 15b is positioned slightly above the lower end surface of the nozzle body 15a.

  The blow molding apparatus 1 includes a stretching rod 21 for stretching the preform 2 in the longitudinal direction. The extending rod 21 is slidably mounted in a hole provided in the axial center of the seal body 20, and is movable relative to the seal body 20 in the axial direction, that is, in the vertical direction. During the blow molding, the stretching rod 21 is moved downward with respect to the seal body 20, so that the preform 2 disposed in the mold 11 is axially (longitudinal) by the stretching rod 21 inside the cavity 12. ). That is, the blow molding apparatus 1 can perform biaxial stretch blow molding of the preform 2.

  A claw portion 14a is provided at the lower end of the main body block 14, and when the nozzle unit 13 is lowered to a predetermined position and the nozzle main body 15a is inserted into the mouth portion 3 of the preform 2, the claw portion 14a. And the upper surface of the mold 11, the neck support portion 4 is sandwiched between them and the preform 2 is fixed to the mold 11.

  The blow molding apparatus 1 is provided with a suction mechanism for preventing incompressible fluid from dripping from the nozzle 15 after blow molding. This suction mechanism is connected to the vertical hole 31 via a plurality of suction holes 30 provided on the inner peripheral surface of the nozzle 15, a vertical hole 31 provided in the nozzle body 15 a extending along the axial direction, and a suction path 32. A suction pump 33 is provided.

  As shown in FIGS. 2 and 3, four suction holes 30 are arranged on the inner peripheral surface of the nozzle body 15 a so as to be arranged at equal intervals in the circumferential direction on the clamping portion 15 b side. In addition to the four suction holes 30, a set of three suction holes 30 arranged in the axial direction on the lower side of the suction holes 30 is provided on the inner peripheral surface of the nozzle body 15 a in the circumferential direction. Eight sets are arranged in equal intervals. That is, a total of 28 suction holes 30 are provided on the inner peripheral surface of the nozzle body 15a.

  On the other hand, eight vertical holes 31 are provided in the nozzle body 15a of the nozzle 15 at regular intervals in the circumferential direction, and the three suction holes 30 of each set are connected to each other by the corresponding vertical holes 31. The four suction holes 30 on the most clamping part 15b side are connected to the other suction holes 30 by corresponding vertical holes 31, respectively.

  In the case shown in the figure, three annular slits 34 extending along the circumferential direction of the inner peripheral surface are arranged on the inner peripheral surface of the nozzle body 15a with an interval in the axial direction (vertical direction) of the nozzle 15. Is provided. Each of the annular slits 34 is formed to a depth reaching the vertical hole 31, and the three suction holes 30 on the lower side of each set are respectively formed at portions intersecting with the vertical holes 31 of the annular slit 34. ing. That is, the vertical hole 31 formed in the nozzle body 15 a opens on the inner peripheral surface of the nozzle body 15 a at a portion intersecting with each annular slit 34, and the opening serves as the suction hole 30. With such a configuration, a plurality of suction holes 30 connected to each other by the vertical holes 31 can be easily formed in the nozzle body 15a.

  In FIG. 1, for convenience, only one suction hole 30, vertical hole 31, and annular slit 34 are denoted by reference numerals.

  As shown in FIG. 1, each of the vertical holes 31 is connected to a suction pump 33 via a suction path 32 at the upper end thereof. The suction pump 33 can be constituted by, for example, a vacuum pump or the like, and is connected to each suction hole 30 via the suction path 32 and the vertical hole 31. The suction pump 33 can generate a suction force for sucking the incompressible fluid adhering to the nozzle body 15 a in each suction hole 30.

  Of the plurality of suction holes 30 provided on the inner peripheral surface of the nozzle body 15a, the suction hole 30 disposed at the lowermost position is preferably disposed in the vicinity of the lower end of the nozzle body 15a. With this arrangement, as shown in FIG. 1, when the seal body 20 is in the closed position, the lower end of the extension 20b of the seal body 20 is close to the suction hole 30 disposed at the lowest position. Therefore, the incompressible fluid adhering to the lower end surface of the seal body 20 can be effectively sucked by the lowermost suction hole 30.

  In this case, the lowermost suction hole 30 can be arranged so as to be positioned slightly above the lower end of the extension 20b of the seal body 20 when the seal body 20 is in the closed position. It can also be arranged at the same height as the lower end of the extension part 20b of the body 20, or can be arranged so as to be located slightly below the lower end of the extension part 20b of the opening / closing body 20.

  In the illustrated case, the lower end of the vertical hole 31 is opened at the lower end surface of the nozzle body 15a, thereby forming a downward suction hole 35 on the lower end surface of the nozzle body 15a. The downward suction hole 35 is also connected to the suction pump 33 through the vertical hole 31 and the suction path 32. Therefore, the incompressible fluid adhering to the lower end surface of the nozzle body 15a can be efficiently sucked by the downward suction holes 35.

  Next, a procedure for blow-molding the preform 2 using such a blow-molding apparatus 1 will be described.

  In a state where the seal body 20 is in the closed position and the nozzle 15 is closed, the preform 2 is placed (attached) to the mold 11, the nozzle unit 13 is then lowered, and the nozzle body 15 a is moved to the mouth 3 of the preform 2. (The state shown in FIG. 1). At this time, the extending rod 21 is at the origin position where the lower end is located above the lower end of the extension 20 b of the seal body 20.

  Next, the nozzle 15 is opened by the seal body 20 moving to the open position. When the nozzle 15 is opened, the pressurized incompressible fluid is supplied from the pressurized fluid supply unit 18 to the inside of the preform 2 through the supply channel 16 and the nozzle 15, and the preform 2 is not compressed. Blow molding (liquid blow molding) is performed with a sexual fluid. Further, during blow molding, the preform 2 is stretched in the axial direction (longitudinal direction) by the stretch rod 21 by moving the stretch rod 21 downward. By such biaxial stretch blow molding, the preform 2 is molded into a bowl-shaped container C along the cavity 12 of the mold 11 (state shown in FIG. 4).

  When blow molding is completed, the seal body 20 moves downward to the closed position, the nozzle 15 is closed, the supply of the incompressible fluid is stopped, and the lower end of the stretching rod 21 is an extension of the seal body 20. It rises to a position coinciding with the lower end of the portion 20b (state shown in FIG. 5).

  In addition, after the blow molding is completed, the suction pump 33 starts operating, and the incompressible fluid attached to the surfaces of the nozzle 15, the seal body 20, and the stretching rod 21 is sucked from the suction holes 30 and 35.

  At this time, since a plurality of suction holes 30 are arranged in the axial direction on the inner peripheral surface of the nozzle main body 15a, the nozzle main body 15a adheres to the inner peripheral surface of the nozzle main body 15a during blow molding. The incompressible fluid that hangs down from the upper side to the lower side can be effectively sucked by these suction holes 30. In particular, when the suction hole 30 is provided at the intersection of the annular slit 34 and the vertical hole 31 as in the present embodiment, the nozzle adheres to the inner peripheral surface of the nozzle body 15a during blow molding. Since the incompressible fluid that hangs down from the upper side to the lower side of the main body 15a can be sucked from the suction holes 30 while being held by these annular slits 34, the incompressible fluid is sucked more effectively. can do. Therefore, as shown in FIG. 6, when the nozzle unit 13 is lifted after blow molding and the nozzle body 15a is detached from the mouth 3 of the container C, the incompressible fluid attached to the inner surface of the nozzle body 15a is removed. It is possible to prevent dripping down toward the container C and the mold 11 after molding.

  That is, in this blow molding apparatus 1, since the plurality of suction holes 30 are arranged side by side in the axial direction on the inner peripheral surface of the nozzle body 15a, the incompressible fluid attached to the inner peripheral surface of the nozzle body 15a. Can be effectively sucked by the suction hole 30 to prevent the incompressible fluid from dripping from the nozzle 15. In particular, even when a relatively high-viscosity liquid such as a shampoo or liquid detergent is used as the incompressible fluid, the liquid can be prevented from dripping and efficiently blown without increasing the cycle time. Molding can be performed.

  In this blow molding apparatus 1, by providing the seal body 20 with the extension 20b, the space inside the nozzle body 15a when the seal body 20 is closed is extended with the inner peripheral surface of the nozzle body 15a. The amount of the incompressible fluid adhering to the inner peripheral surface of the nozzle body 15a can be reduced by using only a small gap between the outer peripheral surface of the portion 20b. Further, the incompressible fluid in the gap can be effectively sucked from the plurality of suction holes 30. Therefore, in this blow molding apparatus 1, when the nozzle unit 13 is raised after blow molding and the nozzle body 15 a is detached from the mouth 3 of the container C, the container C or the like can be removed from the lower surface of the nozzle body 15 a or the seal body 20. It is possible to more reliably prevent the incompressible fluid from dripping toward the mold 11.

  In particular, as in the present embodiment, among the plurality of suction holes 30 provided on the inner peripheral surface of the nozzle body 15a, the suction hole 30 disposed at the lowermost position is disposed near the lower end of the nozzle body 15a. For this purpose, the incompressible fluid adhering to the lower end surface of the nozzle body 15a and the seal body 20 can be effectively sucked along the lower end surface to more reliably prevent the incompressible fluid from dripping. it can.

  Further, in this blow molding apparatus 1, since the downward suction hole 35 is also provided on the lower end surface of the nozzle body 15a, the uncompressed material that has flowed down from the upper side of the nozzle body 15a and adhered to the lower end surface of the nozzle body 15a. The sex fluid can be reliably sucked through the suction hole 35. Thereby, the dripping of the incompressible fluid from the nozzle body 15a toward the container C and the mold 11 can be prevented more reliably. Moreover, the incompressible fluid adhering to the lower end surface of the seal body 20 can be effectively sucked by the downward suction hole 35.

  By the way, if the extending rod 21 is raised to the origin position where the lower end of the extending rod 21 is located above the lower end of the extension 20b of the sealing body 20 after blow molding, the extending rod 21 is not disposed inside the sealing body 20. A space is created (see FIG. 1), and the incompressible fluid adheres to the inner surface of the space. Then, when the nozzle unit 13 is raised in this state, the incompressible fluid attached to the inner surface of the space is pushed out toward the lower end of the seal body 20 by the stretching rod 21 and hangs down from the lower end of the seal body 20. It will be.

  On the other hand, in this blow molding apparatus 1, after the blow molding, the stretching rod 21 is once raised to a position where the lower end thereof coincides with the lower end of the extension 20 b of the seal body 20. A space for the incompressible fluid to enter inside is prevented. Further, by sucking from the suction hole 30 in this state, the incompressible fluid attached to the surface of the seal body 20 is sucked. Then, when the nozzle unit 13, that is, the nozzle 15 is raised with respect to the mouth 3 of the container C and the nozzle body 15 a is detached from the mouth 3 of the container C, as shown in FIG. Are synchronized with the nozzle 15 and the seal body 20, that is, the extending rod 21 is raised integrally with the seal body 20. This prevents the incompressible fluid from adhering to the inner surface of the seal body 20 as described above and the adhering incompressible fluid from being pushed downward, so that the incompressible fluid drips from the seal body 20. Can be effectively prevented.

  When the nozzle unit 13 is raised after blow molding, the lower end of the nozzle body 15a is slightly separated from the upper surface of the incompressible fluid (for example, 1.4 mm upward from the position during blow molding). The nozzle unit 13 is temporarily raised to the position), and suction from the suction hole 30 is performed for a predetermined time (for example, 3 seconds) in that state, and then the nozzle unit 13 is raised to the predetermined position shown in FIG. It can also be. With such a configuration, suction by the suction holes 30 and 35 is performed while the lower end of the nozzle body 15a is drained from the incompressible fluid in the container C, so that the incompressible fluid can be more reliably dropped. Can be prevented.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

  For example, the blow molding apparatus 1 can be configured not to be provided with the stretching rod 21, or can be configured to be configured without the suction mechanism, that is, the suction hole 30, the vertical hole 31, and the suction pump 33, and is stretched after blow molding. A configuration in which the rod 21 does not rise in synchronism with the nozzle 15 after being temporarily stopped but rises as it is to the original position after blow molding can be employed.

  Further, in the case where a plurality of suction holes 30 are arranged side by side in the axial direction of the nozzle 15 on the inner peripheral surface of the nozzle body 15a, the number and positions of the suction holes 30 and the vertical holes 31 provided in the nozzle 15 The shape and the like can be arbitrarily set. Further, the suction hole 30 can be provided directly on the inner peripheral surface of the nozzle body 15a without using the annular slit 34.

  Further, after blow molding, immediately before closing the seal body 20, the pressurized fluid supply unit 18 is operated in the reverse direction to suck back a predetermined amount of incompressible fluid from the container C toward the supply flow path 16. It can also be configured.

DESCRIPTION OF SYMBOLS 1 Blow molding apparatus 2 Preform 3 Mouth part 4 Neck support part 11 Mold 12 Cavity 13 Nozzle unit 14 Main body block 14a Claw part 15 Nozzle part 15a Nozzle body 15b Clamping part 15c Closed surface 16 Supply flow path 17 Pipe 18 Supply of pressurized fluid Part 20 Seal body 20a Seal body body part 20b Extension part 20c Tapered surface 21 Stretching rod 30 Suction hole 31 Vertical hole 32 Suction path 33 Suction pump 34 Annular slit 35 Suction hole C Container

Claims (4)

A blow molding device for blow molding a resin preform into a container of a predetermined shape,
A mold for blow molding in which the preform is disposed;
A cylindrical nozzle inserted into the mouth of the preform from the lower end side;
A pressurized fluid supply section for supplying a pressurized incompressible fluid to a supply flow path connected to the nozzle from the upper end side;
A seal body that is movable between a closed position that contacts the upper end of the nozzle to close the nozzle and an open position that opens the nozzle away from the upper end of the nozzle;
The sealing body is
A seal body main body that contacts the upper end of the nozzle when the seal body is in a closed position;
An extension that is provided projecting downward from the seal body main body and disposed inside the nozzle with a slight gap from the inner peripheral surface of the nozzle when the seal body is in the closed position. With
A blow molding apparatus, wherein a lower end of the extension portion is close to a lower end surface of the nozzle when the seal body is in a closed position. A plurality of suction holes provided side by side in the axial direction of the nozzle on the inner peripheral surface of the nozzle;
A vertical hole provided in the nozzle so as to extend along the axial direction, and connecting the plurality of suction holes to each other;
2. The blow molding apparatus according to claim 1, further comprising: a suction pump that is connected to the vertical hole via a suction path and applies a suction force for sucking the incompressible fluid attached to the nozzle to the plurality of suction holes. . Provided at the axial center of the seal body so as to be relatively movable in the axial direction with respect to the seal body, and provided with a stretching rod that moves downward in blow molding to stretch the preform in the axial direction;
The stretching rod, after stretching the preform, rises to a position where the lower end of the stretching rod coincides with the lower end of the sealing body when the sealing body is in the closed position, and the sealing body is The blow molding apparatus according to claim 1, wherein the blow molding device rises in synchronization with the seal body when the nozzle rises together with the nozzle.   The blow molding apparatus according to any one of claims 1 to 3, wherein the incompressible fluid has a viscosity of 10,000 mPa · s or less when supplied to the preform.

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