WO2020110516A1

WO2020110516A1 - Blow molding device

Info

Publication number: WO2020110516A1
Application number: PCT/JP2019/041392
Authority: WO
Inventors: 星野　英明; 満塩川; 雄一奥山
Original assignee: 株式会社吉野工業所
Priority date: 2018-11-27
Filing date: 2019-10-21
Publication date: 2020-06-04

Abstract

A blow molding device (1) is provided with a nozzle (7), a pressurized fluid supply source (10), a seal body (11), and a rod (16). The seal body (11) is provided with a cylinder wall (11b). An inner peripheral surface of the seal body (11) has a communication recessed part (17) extending from the lower end of the cylinder wall (11b) to a communication hole (18) opening onto an outer peripheral surface of the cylinder wall (11b). The nozzle (7) has a communication path (20). The blow molding device (1) is further provided with at least one of a fluid suction source (22) that is capable of sucking an incompressible fluid from the communication recessed part (17) via the communication path (20) and the communication port (18) and a pressurized gas supply source that is capable of supplying pressurized gas for blowing the incompressible fluid from the communication recessed part (17) via the communication path (20) and the communication port (18).

Description

Blow molding equipment

The present invention relates to a blow molding device.

Resin containers such as bottles made of polypropylene (PP) and bottles made of polyethylene terephthalate (PET) (pet bottles) can be used in a variety of beverages, cosmetics, chemicals, detergents, toiletries such as shampoo, etc. It is used as a container for contents. In such a container, a resin-made preform formed into a bottomed tubular 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 molding is performed using a blow molding device. It is generally formed into a predetermined shape by stretch blow molding.

As a blow molding device, it is known to use a non-compressible fluid such as a pressurized liquid instead of pressurized air as the pressurized fluid supplied into the preform. In this case, by using the content that is finally filled into the container as a product as a fluid for pressurization, the step of filling the content into the container is omitted, and the production process and the configuration of the blow molding device are simplified. Can be converted.

For example, in Patent Document 1, a mold in which a preform can be arranged, a nozzle that can be engaged with a mouth portion of the preform, a pressurized fluid supply source that can supply a liquid pressurized to the nozzle, and a vertical direction A movable stretching rod is provided, and while the stretching rod stretches the preform in the longitudinal direction (axial direction), the pressurized liquid is supplied into the preform to stretch the preform in the lateral direction (radial direction). Then, a blow molding device for molding the preform into a container having a shape along the cavity of the mold is described.

JP, 2013-208834, A

In the conventional blow molding apparatus as shown in Patent Document 1, when the nozzle is lifted after blow molding and the nozzle is detached from the mouth of the container, the liquid adhered to the surface of the nozzle or the surface of the stretching rod ( Incompressible fluid) may drip downwards. In particular, when a relatively high-viscosity liquid such as shampoo or liquid detergent is used as the non-compressible fluid for blow molding, it takes a long time until the liquid drips from the nozzle after the blow molding, and Since the liquid continues to hang down like a string for a while, the liquid is likely to drip into the molded container or the mold after the container is taken out, and the liquid may adhere to these.

The present invention has been made in view of such a problem, and its object is to prevent the incompressible fluid from dripping from the nozzle when the nozzle is separated from the mouth after blow molding, and thus, An object of the present invention is to provide a blow molding device capable of suppressing the fluid from adhering to a container or a mold after molding.

The blow molding apparatus of the present invention includes a cylindrical nozzle, a pressurized fluid supply source capable of supplying an incompressible fluid pressurized to the nozzle, a closed position for closing the nozzle, and an open position for opening the nozzle. And a rod that has an outer peripheral surface facing the inner peripheral surface of the seal body and that is movable in the vertical direction. A sealing wall, which has an outer peripheral surface facing the nozzle when the body is in the closed position, and the inner peripheral surface of the seal body has a communication opening that opens from the lower end of the cylindrical wall to the outer peripheral surface of the cylindrical wall. A communication recess is formed that extends to a recess, and the nozzle is provided with a communication passage that communicates with the communication opening when the seal body is in the closed position. A fluid suction source capable of sucking the non-compressible fluid from the communication recess through the communication port, and a pressurized gas capable of blowing the non-compressible fluid from the communication recess through the communication passage and the communication port. At least one of a compressed gas supply source is further provided.

In the blow molding device of the present invention, in the above-mentioned configuration, the communication recess is composed of a plurality of vertical grooves that are provided at equal intervals in a circumferential direction of the cylindrical wall and extend along a vertical direction. It is preferable that the inner peripheral surface of the cylindrical wall located between the vertical grooves of the above-mentioned groove is in contact with the outer peripheral surface of the rod.

In the blow molding device of the present invention, in the above configuration, it is preferable that the outer peripheral surface of the seal body is provided with an outer communication concave portion that is a concave shape extending from the lower end of the cylindrical wall to the communication port.

In the blow molding device of the present invention, in the above-mentioned configuration, the outer communication recesses are constituted by a plurality of outer vertical grooves that are provided at equal intervals in the circumferential direction of the cylindrical wall and extend along the vertical direction. Is preferred.

According to the present invention, it is possible to prevent the incompressible fluid from dripping from the nozzle when the nozzle is detached from the mouth after blow molding, and thus the fluid is attached to the container or the mold after the molding. It is possible to provide a blow molding apparatus that can suppress the blow molding.

It is a longitudinal section showing the blow molding device concerning one embodiment of the present invention in a standby state. It is a bottom view of the extending|stretching rod shown in FIG. 1, a sealing body, and a nozzle. It is a longitudinal cross-sectional view which shows the blow molding apparatus shown in FIG. 1 in the state at the time of blow molding. It is a longitudinal cross-sectional view which shows the blow molding apparatus shown in FIG. 1 in the state which removed the nozzle from the container after blow molding. (A) is a longitudinal sectional view showing a modified example of the blow molding apparatus shown in FIG. 1, and (b) is a bottom view of the stretch rod, the seal body and the nozzle shown in (a). (A) is a longitudinal sectional view showing another modified example of the blow molding apparatus shown in FIG. 1, and (b) is a bottom view of the stretch rod, the seal body and the nozzle shown in (a).

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

In this specification, the vertical direction means the vertical direction. Further, in the embodiment of the present invention described below, the nozzle 7, the seal body 11, and the rod 16 have a common central axis line O along the vertical direction. In the present embodiment, the vertical cross section means a cross section along a plane including the central axis O, and the horizontal cross section means a cross section along a plane perpendicular to the central axis O. The radial direction of the central axis O is also simply referred to as the radial direction, the circumferential direction of the central axis O is simply referred to as the circumferential direction, and the axial direction of the central axis O is also simply referred to as the axial direction.

As shown in FIG. 1, a blow molding device 1 according to an embodiment of the present invention is a device for blow molding a bottomed cylindrical preform 2 having a mouth 2a into a container C (see FIG. 3). The blow molding apparatus 1 has a mold 3 on which the preform 2 can be placed. Although only a part is shown in the figure, the cavity 4 of the mold 3 has a bottle shape and is open on the upper surface of the mold 3. The preform 2 is placed in the mold 3 in a standing posture with its mouth 2a facing upward. When the preform 2 is placed in the mold 3, the mouth 2a projects upward from the cavity 4. Although not shown in detail, the mold 3 can be opened right and left, and the container C after molding can be taken out from the mold 3 by opening the mold 3.

As the preform 2, a thermoplastic resin material, such as polypropylene (PP), polyethylene terephthalate (PET), polyethylene (PE), which exhibits extensibility by heating, is subjected to bottom molding by injection molding, compression molding, extrusion molding, or the like. A tubular member can be used.

A nozzle unit 5 is provided above the mold 3 so as to be vertically movable relative to the mold 3. The nozzle unit 5 has a main body block 6. The main body block 6 is configured by combining a plurality of members, but illustration and description of details thereof are omitted.

The nozzle unit 5 is provided with a cylindrical nozzle 7 that can be engaged with the opening 2a of the preform 2. The nozzle 7 has a nozzle tip 7a formed in a cylindrical shape having an outer diameter smaller than the inner diameter of the mouth 2a of the preform 2, and the lower end surface of the nozzle tip 7a has the mouth 2a of the preform 2. Is contacted with a step formed on the inner surface of the. The outer diameter of the nozzle tip 7a may be equal to the inner diameter of the mouth 2a of the preform 2 so that the outer peripheral surface of the nozzle tip 7a abuts the inner peripheral surface of the mouth 2a. The nozzle 7 can be engaged with the mouth 2a by inserting the nozzle tip 7a into the mouth 2a of the preform 2. Further, the nozzle 7 has a sandwiching portion 7b integrally provided on the upper side of the nozzle tip 7a, and is sandwiched and fixed to the inner surface of the main body block 6 at the sandwiching portion 7b. The nozzle 7 can be formed of, for example, a steel material or a resin material.

The nozzle 7 is arranged coaxially with the cavity 4 of the mold 3. Therefore, by lowering the nozzle unit 5 to a predetermined position, the nozzle tip 7a can be inserted into the mouth 2a of the preform 2 arranged in the mold 3.

A supply path 8 extending vertically is provided inside the main body block 6, and the supply path 8 is connected to the nozzle 7 from above. A pressurized fluid supply source 10 is connected to the supply passage 8 via a pipe 9. The pressurized fluid supply source 10 can supply the incompressible fluid pressurized to a predetermined pressure to the nozzle 7 through the pipe 9 and the supply passage 8. That is, the pressurized fluid supply source 10 can supply the pressurized incompressible fluid to the preform 2 via the pipe 9, the supply passage 8 and the nozzle 7 during blow molding.

As the pressurized fluid supply source 10, it is preferable to use, for example, a configuration using a plunger pump as a pressurized source, but to supply the supply passage 8 with an incompressible fluid pressurized to a predetermined pressure. Other configurations can also be used as long as the above can be achieved.

As the non-compressible fluid supplied from the pressurized fluid supply source 10 to the nozzle 7, that is, the preform 2, a relatively viscous liquid such as shampoo or 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.

A cylindrical seal body 11 for opening and closing the nozzle 7 is arranged inside the supply passage 8. The seal body 11 is vertically movable between a closed position where it abuts against the nozzle 7 from above and closes the nozzle 7 and an open position where the nozzle 7 is separated from the nozzle 7 and opened. The seal body 11 includes a cylindrical shaft body (not shown), a cylindrical large-diameter portion 11a integrally connected to the lower end of the shaft body and having an outer diameter larger than that of the shaft body, and the large-diameter portion. The cylindrical wall 11b is integrally connected to the lower end of 11a and has a cylindrical outer diameter smaller than the large diameter portion 11a. A downward conical inclined surface 12 is provided at the lower end of the large diameter portion 11a.

The seal body 11 is composed of a single member made of a steel material, a resin material, or the like. The seal body 11 may be composed of a plurality of members.

The upper surface of the nozzle 7, that is, the upper surface of the sandwiching portion 7b of the nozzle 7 has a downward conical closing surface 15. The seal body 11 moves to the closed position that is the lower stroke end, and the inclined surface 12 provided at the lower end of the large diameter portion 11a comes into contact with the closed surface 15 from above, whereby the supply passage 8 and the nozzle tip 7a. The nozzle 7 can be closed by blocking the communication with the seal body 11. Further, the seal body 11 moves upward from the closed position to the open position, and the inclined surface 12 separates upward from the closed surface 15 of the nozzle 7, whereby the supply path 8 and the nozzle tip 7a communicate with each other. The nozzle 7 can be opened. The shapes of the inclined surface 12 and the closed surface 15 can be changed appropriately. Further, the nozzle 7 may be configured to be opened and closed by abutting and releasing the outer peripheral surface of the cylindrical wall 11b and the inner peripheral surface of the nozzle 7.

The nozzle tip 7a is inserted into the mouth 2a of the preform 2 placed in the mold 3, and the nozzle 7 is opened by the seal body 11 in a state where the pressurized fluid supply source 10 is operated, thereby providing the pressurized fluid supply source. A pressurized non-compressible fluid can be supplied from the nozzle 10 through the nozzle 7 into the preform 2 to blow mold the preform 2. Further, by closing the nozzle 7 with the seal body 11 after blow molding, it is possible to stop the supply of the incompressible fluid to the container C after molding.

The blow molding apparatus 1 includes a rod 16 which is surrounded by the seal body 11 and is movable in the vertical direction. In this embodiment, the rod 16 is used as a rod for biaxial stretching. Therefore, in the following description, the rod 16 is also referred to as the stretch rod 16. The extension rod 16 is slidably mounted in a hole provided at the axial center of the seal body 11 and is movable relative to the seal body 11 in the axial direction, that is, in the vertical direction. At the time of blow molding, by moving the stretch rod 16 downward with respect to the seal body 11, the preform 2 arranged in the mold 3 is axially (longitudinally) moved by the stretch rod 16 inside the cavity 4. ). That is, the blow molding apparatus 1 can biaxially stretch blow mold the preform 2. The extension rod 16 has a solid cylindrical shape.

The inner peripheral surface of the nozzle 7 (nozzle tip 7a and sandwiching portion 7b) has a cylindrical inner peripheral surface shape. The cylindrical wall 11b of the seal body 11 has an outer peripheral surface that faces the inner peripheral surface of the nozzle 7 when the seal body 11 is in the closed position. A small gap is provided between the outer peripheral surface of the cylinder wall 11b and the inner peripheral surface of the nozzle 7 in order to reduce the sliding resistance between them. The outer peripheral surface of the cylindrical wall 11b may be provided so as to be in sliding contact with the inner peripheral surface of the nozzle 7. The cylindrical wall 11b is configured such that the lower end of the cylindrical wall 11b is flush with the lower end of the nozzle tip 7a when the seal body 11 is in the closed position.

The blow molding apparatus 1 is provided with a suction mechanism to prevent the non-compressible fluid from dropping from the stretch rod 16, the seal body 11 and the nozzle 7 after blow molding. This suction mechanism includes a communication recess 17 provided on the inner peripheral surface of the seal body 11, a communication port 18 opening on the outer peripheral surface of the cylindrical wall 11b, a communication passage 20 provided on the nozzle 7, and the communication passage 20. And a fluid suction source 22 connected via an on-off valve 21.

As shown in FIGS. 1 and 2, the communication passage 20 is composed of eight radial passages 20a provided at equal intervals in the circumferential direction. Each radial passage 20a has a cylindrical inner peripheral surface shape that extends in the radial direction from one end that opens to the inner peripheral surface of the sandwiching portion 7b to the other end that opens to the outer peripheral surface of the sandwiching portion 7b. Each radial passage 20a may have a cross-sectional shape other than a circular shape, or may extend in a direction inclined to at least one of the axial direction and the circumferential direction with respect to the radial direction. An annular recess 19 concentric with the central axis O is provided on the outer peripheral surface of the sandwiching portion 7b, and the other end of each radial passage 20a is open to this annular recess 19. The annular recess 19 cooperates with the inner peripheral surface of the main body block 6 to form an annular passage 23. Therefore, the other end of each radial passage 20 a is connected to the fluid suction source 22 via the annular passage 23 and the opening/closing valve 21.

The inner peripheral surface of the seal body 11 is provided with a communication recess 17 that has a concave shape and extends from the lower end of the cylindrical wall 11b to the communication port 18 that opens to the outer peripheral surface of the cylindrical wall 11b. The communication recess 17 is composed of eight vertical grooves 17a that extend in the up-down direction and that are provided at equal intervals in the circumferential direction of the cylindrical wall 11b. Each of the vertical grooves 17a has a U-shaped cross-sectional shape that is open radially inward over the entire length (vertical direction). The cross-sectional shape of each vertical groove 17a is not limited to such a U-shape. Further, each vertical groove 17a is not limited to extend in the vertical direction, and may extend spirally around the central axis O, for example. The inner peripheral surface of the cylindrical wall 11b located between the eight vertical grooves 17a is configured to contact the outer peripheral surface of the stretching rod 16. Therefore, the cylindrical wall 11b can exhibit the guiding function of the stretch rod 16. The inner peripheral surface of the cylindrical wall 11b located between the eight vertical grooves 17a may be configured so as not to contact the outer peripheral surface of the stretching rod 16. The lower end of each vertical groove 17a extends to the lower end of the cylindrical wall 11b. The upper end of each vertical groove 17 a extends to the communication port 18. The communication port 18 is composed of an opening 18a having a cylindrical inner peripheral surface, to which the upper ends of the eight vertical grooves 17a are connected. That is, the communication port 18 is composed of such eight openings 18a.

The eight vertical grooves 17a, the openings 18a, and the radial passages 20a do not have to be provided at equal intervals in the circumferential direction. Further, the cross-sectional area of the vertical groove 17a may be individually different. Further, the numbers of the vertical grooves 17a, the openings 18a, and the radial passages 20a are not limited to eight sets, and can be appropriately increased or decreased. Further, the communication port 18 may extend in the circumferential direction of the central axis O so as to communicate with the plurality of vertical grooves 17a. In this case, the number of the vertical grooves 17a and the number of the radial passages 20a may be different from each other. Further, the number of the radial passages 20a may be one, and the opening/closing valve 21 may be provided at the other end of the radial passages 20a. May be connected (that is, the annular passage 23 is not provided). Note that, in FIGS. 1 and 2 and the like, for convenience, only one set of vertical grooves 17a, openings 18a, and radial passages 20a are denoted by reference numerals.

The communication recess 17 is not limited to the vertical groove 17a. For example, the communication recess 17 may include a vertical groove 17a and one or more annular recesses that extend around the entire circumference of the central axis O. The communication recess 17 may be an annular recess that extends from the lower end of the cylindrical wall 11b to the communication port 18 and extends over the entire circumference of the central axis O.

The on-off valve 21 is preferably provided inside the nozzle unit 5, but may be provided outside the nozzle unit 5. The on-off valve 21 is composed of an electric control valve and can be opened/closed by a control means (not shown). However, the on-off valve 21 may be configured by, for example, a pneumatic or hydraulic type control valve or the like.

The fluid suction source 22 is composed of, for example, a vacuum pump, and can suction the incompressible fluid from the annular passage 23 and the communication passage 20 when the opening/closing valve 21 is opened. Therefore, when the seal body 11 is in the closed position and the lower end of the stretching rod 16 is substantially flush with the nozzle tip 7a and the cylindrical wall 11b, the fluid suction source 22 adheres to these lower ends of the incompressible material. The fluid can be sucked through the communication recess 17, the communication port 18, the communication passage 20, and the annular passage 23, and the incompressible fluid can be prevented from dripping.

Next, an example of a procedure for blow-molding the preform 2 with such a blow-molding apparatus 1 will be shown.

First, as shown in FIG. 1, the preform 2 is placed in the mold 3 with the seal body 11 in the closed position and the nozzle 7 closed. Next, the nozzle unit 5 descends and the nozzle tip 7a is inserted into the mouth 2a of the preform 2. At this time, the extending rod 16 is at the origin position where the lower end thereof is flush with the lower end of the cylindrical wall 11b of the seal body 11.

Next, the nozzle 7 is opened by moving the seal body 11 to the open position. When the nozzle 7 is opened, the pressurized incompressible fluid is supplied from the pressurized fluid supply source 10 into the inside of the preform 2 through the supply passage 8 and the nozzle 7, and the preform 2 is incompressible. Blow molding (liquid blow molding) is performed with a sex fluid. Further, during the blow molding, the draw rod 16 descends so that the preform 2 is drawn by the draw rod 16 in the axial direction (longitudinal direction). By such biaxial stretch blow molding, the preform 2 is molded into a bottle-shaped container C along the cavity 4 of the mold 3, as shown in FIG.

When the blow molding is completed, the seal body 11 descends to the closed position, the nozzle 7 is closed and the supply of the incompressible fluid is stopped, and the stretch rod 16 is moved to the closed position as shown by the two-dot chain line in FIG. The lower end moves up to a position where the lower end is flush with the lower end of the cylindrical wall 11b of the seal body 11, that is, the origin position. Then, as shown in FIG. 4, the nozzle unit 5 rises and the nozzle tip 7a is separated upward from the mouth Ca of the container C. The timing at which the stretching rod 16 moves up to the origin position may be before or after the nozzle tip 7a is separated from the mouth Ca of the container C. At this time, the stretching rod 16 rises and is withdrawn from the incompressible fluid inside the container C, so that a head space corresponding to the volume of the drawn rod is formed inside the container C. However, the headspace may be formed by other methods. The rod 16 may be used not as a rod for biaxial stretching but as a rod for forming a head space.

Further, after the completion of blow molding, the on-off valve 21 is opened, the fluid suction source 22 starts to operate, and the incompressible fluid attached to the nozzle tip 7a, the cylinder wall 11b and the lower end of the stretching rod 16 is discharged as shown in FIG. As indicated by a dashed arrow, the suction is made from the communication recess 17, the communication port 18, the communication passage 20, and the annular passage 23. When the stretching rod 16 rises after blow molding, since the incompressible fluid adhering to the outer peripheral surface of the stretching rod 16 can be directly sucked from the communicating recess 17 provided on the inner peripheral surface of the seal body 11, the stretching is performed. The incompressible fluid attached to the outer peripheral surface of the rod 16 can be effectively sucked. Further, at this time, since the stretch rod 16 is handled by the seal body 11, the non-compressible fluid attached to the outer peripheral surface of the stretch rod 16 can be stored near the upper end of the communication recess 17, and from this point as well, The incompressible fluid attached to the outer peripheral surface of the stretching rod 16 can be effectively sucked.

As described above, in the blow molding apparatus 1, since the communication recess 17 extending from the lower end of the cylinder wall 11b to the communication port 18 is provided on the inner peripheral surface of the seal body 11, the nozzle tip 7a, the cylinder wall 11b, and the extension. Not only the incompressible fluid attached to the lower end of the rod 16 but also the incompressible fluid attached to the outer peripheral surface of the stretching rod 16 is effectively sucked by the communication recessed portion 17 to drip the incompressible fluid from the nozzle 7. Therefore, it is possible to prevent the incompressible fluid from adhering to the container C or the mold 3 after molding. In particular, according to the blow molding apparatus 1, even when a liquid having a relatively high viscosity such as shampoo or liquid detergent is used as the non-compressible fluid, the liquid is suppressed from dripping and the cycle is reduced. Blow molding can be efficiently performed while suppressing an increase in time.

Further, after the blow molding is completed, the stretch rod 16 is raised to a position where its lower end is flush with the upper end of the communication recess 17, as shown by the solid line in FIG. The incompressible fluid attached to the lower end of 16 may be sucked through the communication recess 17, the communication port 18, and the communication passage 20. The timing at which the stretching rod 16 is raised to the position may be before or after the nozzle tip 7a is separated from the mouth Ca of the container C. By doing so, the incompressible fluid attached to the lower end of the stretching rod 16 can be efficiently sucked. Further, after sucking the incompressible fluid attached to the lower end of the stretching rod 16 in this way, the stretching rod 16 is lowered to the origin position, and in this state, the nozzle tip 7a, the cylinder wall 11b and the stretching rod 16 are The incompressible fluid attached to the lower end may be sucked through the communication recess 17, the communication port 18, and the communication passage 20. By doing so, it is possible to more efficiently suck the incompressible fluid.

Next, a modification of the blow molding device 1 will be described.

As shown in FIGS. 5A and 5B, in the blow molding apparatus 1 of the present modification, the nozzle 7 has eight vertical holes 24 that open at the lower end of the nozzle tip 7 a and the inner peripheral surface of the nozzle 7. It has three annular grooves 25 which are provided in an annular shape centered on the central axis O provided. Note that, in FIGS. 5A and 5B, for convenience, only one vertical hole 24 and one annular groove 25 are denoted by reference numerals. Further, in FIG. 5A, illustration of the mold 3 and the preform 2 is omitted. In FIGS. 5A and 5B, parts corresponding to the parts shown in the above-described embodiment are designated by the same reference numerals.

Each of the vertical holes 24 extends in the vertical direction and has an opening at the upper end thereof in the radial passage 20a. The three annular grooves 25 are arranged side by side in the axial direction. Each annular groove 25 intersects with eight vertical holes 24, and an opening is formed at each intersection. The number of the vertical holes 24 can be appropriately increased or decreased according to the number of radial passages. The number of annular grooves 25 can be appropriately increased or decreased. The annular groove 25 may not be provided. Other configurations are similar to those of the above-described embodiment.

With such a configuration, the incompressible fluid can be sucked not only from the communication recess 17 but also from the vertical hole 24 and the annular groove 25 provided in the nozzle 7, so that the nozzle tip 7a, the cylinder wall 11b, and the extension. The incompressible fluid attached to the lower end of the rod 16 can be sucked particularly effectively.

Next, another modification of the blow molding apparatus 1 will be described.

As shown in FIGS. 6(a) and 6(b), the blow molding apparatus 1 of the present modified example has ten vertical grooves 17a extending in the up-down direction and provided at equal intervals in the circumferential direction of the cylindrical wall 11b. It has a communicating recessed part 17 composed of.

Further, in the present modification, the outer peripheral surface of the seal body 11 is provided with an outer communication concave portion 26 having a concave shape extending from the lower end of the cylindrical wall 11b to the communication port 18. The outer communication recessed portion 26 is composed of eight outer vertical grooves 26a that are provided at equal intervals in the circumferential direction of the cylindrical wall 11b and that extend along the vertical direction. Each outer vertical groove 26a has a U-shaped cross-sectional shape that is open radially outward over the entire length (up and down direction). The lateral cross-sectional shape of each outer vertical groove 26a is not limited to such a U-shape. Further, each outer vertical groove 26a is not limited to one extending in the vertical direction, and may be one extending spirally around the central axis O, for example. The outer peripheral surface of the tubular wall 11b located between the eight outer vertical grooves 26a may be spaced apart from the inner peripheral surface of the nozzle tip 7a, or the inner peripheral surface of the nozzle tip 7a. It may be arranged so as to contact with. The lower end of each outer vertical groove 26a extends to the lower end of the cylindrical wall 11b. The upper end of each outer vertical groove 26a extends to the communication port 18.

The communication port 18 is provided on the outer peripheral surface of the seal body 11, and has an annular groove 18b centered on the central axis O to which the upper ends of the outer longitudinal grooves 26a are connected, and ten longitudinal grooves 17a with respect to the annular groove 18b. And a cylindrical inner peripheral surface-shaped opening 18a connecting the upper ends of the respective. Further, in this modification, the communication passage 20 is composed of one radial passage 20a. One end of the radial passage 20a is connected to the annular groove 18b, and the on-off valve 21 is connected to the other end.

6(a) and 6(b), for convenience, only one vertical groove 17a, the opening 18a, and the outer vertical groove 26a are denoted by reference numerals. Further, in FIG. 6A, illustration of the mold 3 and the preform 2 is omitted. In FIGS. 6A and 6B, parts corresponding to the parts shown in the above-described embodiment are designated by the same reference numerals.

Note that the 10 sets of vertical grooves 17a and openings 18a may not be provided at equal intervals in the circumferential direction. The eight outer vertical grooves 26a may not be provided at equal intervals in the circumferential direction. The cross-sectional area of the outer vertical groove 26a may be different. The number of the vertical grooves 17a and the openings 18a is not limited to 10 and can be increased or decreased as appropriate. The number of outer vertical grooves 26a is not limited to eight and can be increased or decreased as appropriate. Further, the communication port 18 is not limited to the one configured by the annular groove 18b and the opening 18a. Also in this modification, the shape of each vertical groove 17a can be changed in various ways as described above. The communication recess 17 is not limited to the vertical groove 17a, and various modifications described above are possible.

According to such a configuration, since the incompressible fluid can be sucked not only from the communication recess 17 but also from the outer communication recess 26 provided on the outer peripheral surface of the seal body 11, the nozzle tip 7a, the cylinder wall 11b, and The incompressible fluid attached to the lower end of the stretching rod 16 can be sucked particularly effectively.

Needless to say, 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, in the above-described embodiment and various modifications thereof, the blow molding device 1 includes the fluid suction source 22 capable of sucking the incompressible fluid from the communication recess 17 via the opening/closing valve 21, the communication passage 20 and the communication port 18. have. However, in the blow molding device 1, instead of or in addition to the fluid suction source 22, the non-compression from the communication recess 17 (or the communication recess 17 and the outer communication recess 26) via the on-off valve 21, the communication passage 20 and the communication port 18. You may have a pressurized gas supply source which can supply the pressurized gas which blows off a sexual fluid. The pressurized gas supply source can be composed of, for example, a plunger pump. According to such a configuration, not only the incompressible fluid attached to the nozzle tip 7a, the cylinder wall 11b and the lower end of the rod 16 but also the incompressible fluid attached to the outer peripheral surface of the rod 16 is blown out from the communication recess 17. Since it can be dropped into the container C as it is, it is possible to prevent the incompressible fluid from dripping from the nozzle 7, so that the incompressible fluid adheres to the container C and the mold 3 after molding. Can be suppressed.

Further, in the above-described embodiment and its modification, the nozzle tip 7a and the cylinder wall 11b have a cylindrical shape, but the nozzle tip 7a and the cylinder wall 11b have a cylindrical shape having a cross-sectional shape such as a polygon or an ellipse. May be done. However, when the mouth 2a of the preform 2 has a cylindrical shape, it is preferable that the outer peripheral surface of the nozzle tip 7a has a cylindrical shape. Further, the lower end of the cylindrical wall 11b may have an annular inclined surface that inclines upward from the outer peripheral edge to the inner peripheral edge inward in the radial direction. For example, the lower end of the cylindrical wall 11b may be composed of an annular horizontal surface and an annular inclined surface located radially inside the annular horizontal surface. In this case, the position where the lower end of the rod 16 matches the upper end of the annular inclined surface can be the origin position of the rod 16.

Further, in the above-described embodiment and its modification, the rod 16 has a solid cylindrical shape. However, the rod 16 may have, for example, in its inside a flow path connected to the pressurized fluid supply source 10. In this case, the rod 16 may be composed of, for example, a cylindrical outer cylinder and a poppet valve-shaped opening/closing rod capable of opening and closing the lower end of the outer cylinder. In addition, a pre-filling step may be provided in which the inside of the preform 2 is filled with an incompressible fluid in advance before the blow molding through the flow path inside the rod 16. In addition, a suck back process may be provided in which the incompressible fluid is sucked back from the inside of the container C after blow molding through the flow path inside the rod 16 toward the pressurized fluid supply source 10. In addition, in the prefill process, an openable/closable air discharge path is provided in the annular passage 23 so that the air inside the preform 2 can be discharged to the outside through the communication recess 17, the communication port 18, the communication passage 20 and the annular passage 23. It may be provided. Even when the flow path is provided in the rod 16, the rod 16 may be used as a rod for biaxial stretching, or the rod 16 may not be used as a rod for biaxial stretching.

Further, in the above-described embodiment and its modification, the cylindrical wall 11b is configured such that the lower end of the cylindrical wall 11b is flush with the lower end of the nozzle tip 7a when the seal body 11 is in the closed position. There is. However, the cylindrical wall 11b is arranged so that the lower end of the cylindrical wall 11b is arranged above or below the lower end of the nozzle tip 7a when the seal body 11 is in the closed position, depending on the type of incompressible fluid. It may be configured.

1 Blow Molding Device 2 Preform 2a Mouth 3 Mold 4 Cavity 5 Nozzle Unit 6 Main Block 7 Nozzle

7a Nozzle Tip

7b Clamping Part 8 Supply Channel 9 Piping 10 Pressurized Fluid Supply Source 11 Sealing Body 11a Large Diameter Section 11b Cylinder Wall 12 inclined surface 15 closed surface 16 rod 17 communication recess 17a vertical groove 18 communication port 18a opening 18b annular groove 19 circular annular recess 20 communication passage 20a radial passage 21 opening/closing valve 22 fluid suction source 23 circular passage 24 vertical hole 25 annular groove 26 Outer communication recessed part 26a Outer vertical groove O Central axis C Container Ca mouth

Claims

A cylindrical nozzle,
A pressurized fluid supply source capable of supplying pressurized incompressible fluid to the nozzle;
A tubular seal body that is vertically movable between a closed position that closes the nozzle and an open position that opens the nozzle;
A rod that has an outer peripheral surface facing the inner peripheral surface of the seal body and is movable in the vertical direction,
The seal body includes a cylindrical wall having an outer peripheral surface facing the nozzle when the seal body is in the closed position,
The inner peripheral surface of the seal body is provided with a communication recessed recess that extends from the lower end of the cylindrical wall to a communication opening that opens to the outer peripheral surface of the cylindrical wall,
The nozzle is provided with a communication passage that communicates with the communication port when the seal body is in the closed position,
A fluid suction source capable of sucking the incompressible fluid from the communication recess through the communication passage and the communication port, and a pressurized gas that blows off the incompressible fluid from the communication recess through the communication passage and the communication port. A blow molding apparatus further comprising at least one of a pressurized gas supply source capable of supplying the gas.
The communication recess is composed of a plurality of vertical grooves extending in the up-down direction provided at equal intervals in the circumferential direction of the cylindrical wall,
The blow molding device according to claim 1, wherein an inner peripheral surface of the cylindrical wall located between the plurality of vertical grooves is in contact with the outer peripheral surface of the rod.
The blow molding device according to claim 1 or 2, wherein the outer peripheral surface of the seal body is provided with an outer communication recess that is a recess extending from the lower end of the cylindrical wall to the communication port.
The blow molding device according to claim 3, wherein the outer communication recesses are formed of a plurality of outer vertical grooves that extend along the up-down direction and that are provided at equal intervals in the circumferential direction of the cylindrical wall.