Mold and resin-made container manufacturing apparatus

Abstract

A mold is provided with a position adjustment mechanism that receives a shaft portion extending from a cavity mold that houses a preform and adjusts the position at which the cavity mold is held in a plane that intersects the extending direction of the shaft portion. The position adjustment mechanism includes a first member that has a linear cam hole that receives the shaft portion, and a second member that is arranged so as to overlap the first member in the extending direction of the shaft portion and rotates relative to the first member along the plane. The second member has an elongated hole that intersects the cam hole in the plane direction and positions the shaft portion together with the cam hole. Further, by the rotation of the second member, the position at which the cam hole and the elongated hole intersect moves in the lengthwise direction of the cam hole.

Description

Technical Field

[0001] This invention relates to an apparatus for manufacturing molds and resin containers. Background Technology

[0002] Previously, hot preform blow molding was known as one of the methods for manufacturing resin containers. Hot preform blow molding is a method of blow molding resin containers by retaining heat during the injection molding of a preform. Compared with cold preform blow molding, it has the advantage of being able to manufacture a variety of aesthetically pleasing resin containers.

[0003] The preform after injection molding may have uneven temperature in the circumferential direction due to factors such as core misalignment of the injection molding die. In order to eliminate this uneven temperature or to give a temperature distribution suitable for the shape of the container, a scheme has been proposed to house the preform after injection molding in a temperature-adjusting mold and adjust the temperature before blow molding (e.g., Patent Document 1, etc.).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 3330677 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] To properly adjust the temperature of the preform, the position of the temperature adjustment mold needs to be adjusted so that the surface of the preform is at an appropriate distance from the inner surface of the mold. This adjustment is performed frequently during molding and is very tedious for the operator.

[0009] Therefore, the present invention was made in view of such a problem, and its object is to provide a mold that can achieve proper positional adjustment of the cavity mold relative to the preform with good workability.

[0010] Methods for solving problems

[0011] One aspect of the invention is a mold comprising a position adjustment mechanism that receives a shaft extending from a cavity mold housing a preform and adjusts the position of the cavity mold held in a plane intersecting the extending direction of the shaft. The position adjustment mechanism comprises: a first member having a linear cam hole for receiving the shaft; and a second member that overlaps with the first member in the extending direction of the shaft and rotates relative to the first member along a plane. The second member has an elongated hole that intersects the cam hole in the planar direction and, together with the cam hole, positions the shaft. Furthermore, by rotating the second member, the position where the cam hole intersects the elongated hole moves along the long side of the cam hole.

[0012] Invention Effects

[0013] According to one aspect of the invention, it is possible to achieve proper positioning of the cavity mold relative to the preform with good workability. Attached Figure Description

[0014] Figure 1 This is a diagram schematically illustrating the structure of the blow molding apparatus according to the first embodiment.

[0015] Figure 2 This is a diagram showing an example of the structure of the temperature adjustment unit.

[0016] Figure 3 This is a top view of the position adjustment mechanism.

[0017] Figure 4 It is a three-dimensional diagram showing the positional relationship between the fixed plate, the movable plate, and the lower mold.

[0018] Figure 5 (a) is a top view of the movable plate, and (b) is a top view of the fixed plate.

[0019] Figure 6 (a) is a top view showing the movable plate overlapping the fixed plate, and (b) is a view showing the state from which the movable plate overlaps the fixed plate. Figure 6 (a) is a diagram showing the state of the movable plate after it has been rotated.

[0020] Figure 7 This is a flowchart illustrating the steps involved in the blow molding process.

[0021] Figure 8 (a) is a top view of the movable plate of the second embodiment, and (b) is a top view of the fixed plate of the second embodiment.

[0022] Figure 9 This is a diagram showing the rotational states of the movable plate and the fixed plate in the second embodiment.

[0023] Figure 10 It means and Figure 9 A cross-sectional view showing the positional relationship between the intermediate mold and the preform. Detailed Implementation

[0024] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0025] In the embodiments, for ease of understanding and explanation, descriptions of structures or elements other than the main parts of the invention are simplified or omitted. Furthermore, in the drawings, the same elements are labeled with the same symbols. Additionally, the shapes, dimensions, etc., of the elements shown in the drawings are schematic and do not represent actual shapes, dimensions, etc.

[0026] First Implementation Method

[0027] <Description of Blow Molding Equipment>

[0028] First, refer to Figure 1 A blow molding apparatus 20 for manufacturing resin containers (hereinafter referred to as containers) will be described. Figure 1 This is a block diagram schematically showing the structure of the blow molding apparatus 20. The first type of blow molding apparatus 20 is a hot preform method (also known as a one-stage method) that effectively utilizes the heat retained during injection molding (internal heat) to perform blow molding without cooling the preform 10 to room temperature.

[0029] The blow molding apparatus 20 includes an injection molding section 21, a temperature adjustment section 22, a blow molding section 23, a take-out section 24, and a conveying mechanism 26. The injection molding section 21, temperature adjustment section 22, blow molding section 23, and take-out section 24 are positioned after rotating each of them by a given angle (e.g., 90 degrees) around the conveying mechanism 26. The blow molding apparatus 20 includes at least one row of neck molds 27 (described later). Furthermore, when the blow molding apparatus 20 has multiple rows (e.g., two or three rows) of neck molds, the molds for each part (the cavity mold 31 of the temperature adjustment section 22 described later) are also configured with the same number of rows.

[0030] (Conveying mechanism 26)

[0031] Conveying mechanism 26 is equipped with the ability to transport Figure 1 A transfer plate (not shown) moves by rotating around a central axis perpendicular to the paper surface. On the transfer plate, one or more neck molds 27 are arranged at given angles to hold the neck of the preform 10 or the container. Figure 1 (Not shown in the diagram). The conveying mechanism 26 moves the transfer plate in 90-degree increments, sequentially conveying the preform 10 (or container) held by the neck mold 27 to the injection molding section 21, the temperature adjustment section 22, the blow molding section 23, and the removal section 24. Furthermore, the conveying mechanism 26 also includes a lifting mechanism (a longitudinal mold opening and closing mechanism), a mold opening mechanism for the neck mold 27, and performs actions related to lifting the transfer plate, mold closing, and mold opening (demolding) with the injection molding section 21, etc. Additionally, the transfer plate can be a circular plate-shaped component that holds all the neck molds at each molding station, or it can be a structure composed of a collection of fan-shaped components that hold the neck molds at each molding station.

[0032] (Injection Molding Section 21)

[0033] The injection molding unit 21 includes an injection cavity mold and an injection core mold (not shown in the figure), which manufacture a preform 10. An injection device 25 for supplying resin material, which serves as the raw material for the preform 10, is connected to the injection molding unit 21.

[0034] In the injection molding section 21, the aforementioned injection cavity mold, injection core mold, and neck mold 27 of the delivery mechanism 26 are closed to form a mold space in the shape of a preform. Then, by injecting resin material from the injection device 25 into such a preform-shaped mold space, a preform 10 is manufactured in the injection molding section 21.

[0035] Here, the preform 10 has an overall shape that is a bottomed cylindrical shape with one end open and the bottom 14 closed at the other end. A neck 12 is formed at the open end of the preform 10.

[0036] Furthermore, the material of the container and the preform 10 is a thermoplastic synthetic resin, which can be appropriately selected according to the intended use of the container. Specific types of materials include, for example, PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PCTA (polycyclohexanediol terephthalate), Tritan (TRITAN: a copolyester manufactured by Eastman Chemical Company), PP (polypropylene), PE (polyethylene), PC (polycarbonate), PES (polyethersulfone), PPSU (polyphenylsulfone), PS (polystyrene), COP / COC (cyclic olefin polymers), PMMA (polymethyl methacrylate: acrylic acid), PLA (polylactic acid), nylon, etc.

[0037] Furthermore, when the injection molding section 21 is opened, the neck mold 27 of the conveying mechanism 26 remains closed and the preform 10 is conveyed unchanged. The number of preforms 10 simultaneously molded by the injection molding section 21 (i.e., the number of containers that can be simultaneously molded by the blow molding device 20) can be appropriately set.

[0038] (Temperature adjustment unit 22)

[0039] The temperature adjustment unit 22 homogenizes and removes temperature deviations in the preform 10 manufactured by the injection molding unit 21, and adjusts the temperature of the preform 10 to a temperature suitable for blow molding (e.g., approximately 90°C to 105°C) and has a temperature distribution suitable for the shape of the container to be shaped. In addition, the temperature adjustment unit 22 can also cool the preform 10 at a high temperature after injection molding.

[0040] Figure 2This diagram illustrates a structural example of the temperature adjustment unit 22. The temperature adjustment unit 22 has a cavity mold (temperature regulating tank) 31 capable of accommodating the preform 10. The cavity mold 31 has a temperature adjustment space with a shape substantially similar to the shape of the preform 10 manufactured by the injection molding unit 21. Additionally, although not particularly limited, the temperature adjustment unit 22 may also include a mold component (temperature adjusting rod) inserted into the interior of the preform 10. Furthermore, depending on the requirements, the horizontal cross-sectional shape of the temperature adjustment space of the cavity mold 31 accommodating the preform can be circular, elliptical, or polygonal.

[0041] The cavity mold 31 of the first embodiment is composed of one or more layers along the axial direction of the preform 10. Preferably, the cavity mold 31 is divided into multiple layers along the axial direction of the preform 10, for example, into three layers, including an upper mold 32, a middle mold 33, and a lower mold 34. The upper mold 32 is the mold facing the outer surface near the neck 12 of the preform 10. The middle mold 33 is the mold facing the outer surface of the main body 13 of the preform 10. The lower mold 34 is the mold facing the outer surface of the bottom 14 of the preform 10. The bottom surface of the upper mold 32 engages with the upper surface of the middle mold 33 via a first fitting portion 35, and the bottom surface of the middle mold 33 engages with the upper surface of the lower mold 34 via a second fitting portion 36. Furthermore, a cylindrical shaft portion 34a protruding towards the bottom side along the vertical direction (axial direction of the preform 10) is formed at the center of the bottom surface of the lower mold 34.

[0042] Heating components, such as belt heaters (not shown), are installed in the upper mold 32, middle mold 33, and lower mold 34 of the cavity mold 31. Therefore, the temperatures of the upper mold 32, middle mold 33, and lower mold 34 are maintained at a given temperature by the heating components. Furthermore, by changing the temperature of the heating components in the upper mold 32, middle mold 33, and lower mold 34, the axial temperature distribution of the preform 10 can also be changed. Additionally, the number of layers constituting the cavity mold 31 can be appropriately varied from one to approximately ten layers depending on the length of the main body 13 of the preform 10.

[0043] The cavity mold 31 is clamped and fixed from both sides by the upper support plate 37 and the lower support plate 38.

[0044] The upper support plate 37 has an opening 37a with a shape corresponding to the neck mold 27 and is disposed on the upper surface side of the upper mold 32. Furthermore, the upper support plate 37 is connected to the lower support plate 38 by a plurality of fixing bolts (fixing members) 39 extending in the vertical direction. Additionally, when the neck mold 27 is lowered relative to the cavity mold 31, the neck mold 27 is disposed in the opening 37a of the upper support plate 37, and the preform 10 held in the neck mold 27 is received in the cavity mold 31.

[0045] The lower support plate 38 is fixed to the lower base (not shown) of the blow molding apparatus 20. A position adjustment mechanism 40 for adjusting the position of the cavity mold 31 is provided on the upper surface of the lower support plate 38. Furthermore, the lower support plate 38 holds the shaft portion 34a of the lower mold 34 via the position adjustment mechanism 40.

[0046] Next, the position adjustment mechanism 40 of the temperature adjustment unit 22 will be described.

[0047] The position adjustment mechanism 40 is responsible for adjusting the position of the cavity mold 31 in one dimension (or horizontal direction) on the plane of the lower support plate 38, which is orthogonal to the vertical direction. Figure 2 As shown, the position adjustment mechanism 40 includes a fixed plate 41 fixed to the lower support plate 38, a movable plate 42, a spacer 49, and a pressing member 44. The fixed plate 41 is an example of the first member, and the movable plate 42 is an example of the second member.

[0048] The fixed plate 41, movable plate 42, and spacer 49 are, for example, components with an overall disc shape. In the assembled state of the position adjustment mechanism 40, the fixed plate 41, movable plate 42, and spacer 49 are sequentially stacked on the lower support plate 38 from bottom to top. The fixed plate 41, movable plate 42, and spacer 49 are inserted through the shaft portion 34a of the lower mold 34. Furthermore, Figure 4 This is a perspective view showing the positional relationship between the fixed plate 41, the movable plate 42, and the lower mold 34. Figure 4 For simplicity, the illustration of spacer 49 has been omitted.

[0049] like Figure 3 As shown, the pressing member 44 is composed of, for example, two open-ring-shaped block members. The pressing member 44 has a space on its inner side for arranging the fixed plate 41, the movable plate 42, and the spacer 49, and is fixed to the lower support plate 38 by bolts (fixing members) 45. The pressing member 44 surrounds and holds the fixed plate 41, the movable plate 42, and the spacer 49 from the outer periphery. Furthermore, the pressing member 44 presses the movable plate 42 against the fixed plate 41 from above via the spacer 49, thereby maintaining the position of the movable plate 42 relative to the rotational direction of the fixed plate 41. Additionally, to prevent positional displacement of the fixed plate 41, the fixed plate 41 and the lower support plate 38 can be fixed by means of locating pins or the like (not shown).

[0050] Figure 5(a) is a top view of the movable plate 42. The movable plate 42 has a disc-shaped movable plate body 42a and a cylindrical protrusion 42b formed on the bottom side of the movable plate body 42a. The protrusion 42b is formed at a position eccentric to the center of the movable plate body 42a. In addition, an elongated hole (first elongated hole) 42c is formed in the movable plate 42, penetrating the movable plate body 42a and the protrusion 42b. The width W of the elongated hole 42c in the short side direction is set to a size that allows the shaft portion 34a of the lower mold 34 to pass through.

[0051] Figure 5 (b) is a top view of the fixing plate 41. The fixing plate 41 has a disc-shaped fixing plate body 41a and a bottomed cylindrical recess 41b formed on the upper surface side of the fixing plate body 41a. The recess 41b is formed at a position eccentric to the center of the fixing plate body 41a, and rotatably receives the protrusion 42b of the movable plate 42 disposed on the upper surface side. The recess 41b has a shape corresponding to the protrusion 42b and is set to a size that can support the protrusion 42b.

[0052] Furthermore, a cam hole (second elongated hole) 41c for receiving the shaft portion 34a of the lower mold 34 is formed on the bottom surface of the recess 41b of the fixed plate 41. The cam hole 41c is shaped to extend linearly along its long side through the center of the fixed plate body 41a. The width W of the short side of the cam hole 41c is set to a size that allows the shaft portion 34a of the lower mold 34 to pass through. In addition, the position of the cam hole 41c partially overlaps with that of the elongated hole 42c of the movable plate 42, but the long side of the cam hole 41c is formed to intersect with the elongated hole 42c.

[0053] Figure 6 (a) is a top view of the state in which the movable plate 42 is superimposed on the fixed plate 41. Figure 6 (b) indicates from Figure 6 (a) is a diagram showing the state of the movable plate 42 after it has been rotated.

[0054] With the movable plate 42 and the fixed plate 41 overlapping vertically, the protrusion 42b of the movable plate 42 is axially supported by the recess 41b of the fixed plate 41, allowing the movable plate 42 to rotate about the protrusion 42b and the recess 41b as rotation axes. Alternatively, the protrusion 42b of the movable plate 42 can be embedded in the recess 41b of the fixed plate 41, and the protrusion 42b can be rotated relative to the recess 41b while its outer peripheral surface abuts against the inner peripheral surface of the recess 41b, thereby causing the movable plate 42 to rotate.

[0055] Furthermore, when viewing the fixed plate 41 and the movable plate 42 from above and below, as... Figure 6As shown in (a) and (b), the elongated hole 42c of the movable plate 42 is arranged to intersect with the cam hole 41c of the fixed plate 41. Therefore, when the shaft portion 34a of the lower mold 34 is inserted into the movable plate 42 and the fixed plate 41, the shaft portion 34a is positioned by being constrained by the inner surface of the cam hole 41c in the short side direction and the inner surface of the elongated hole 42c intersecting the cam hole 41c in the short side direction. Thus, the cavity mold 31 can be positioned and held by the movable plate 42 and the fixed plate 41.

[0056] In addition, such as Figure 6 As shown in (a) and (b), when the movable plate 42 is rotated relative to the fixed plate 41, the overlapping position of the cam hole 41c and the elongated hole 42c moves along the long side direction of the cam hole 41c. That is, by rotating the movable plate 42 relative to the fixed plate 41, the position held by the shaft portion 34a can be adjusted in the long side direction of the cam hole 41c. Thus, the position adjustment (distance adjustment) of the cavity mold 31 facing the preform 10 can be performed by means of the movable plate 42 and the fixed plate 41. That is, the position through which the shaft portion 34a can be inserted is moved a given distance in the long side direction of the cam hole 41c according to the rotation angle of the movable plate 42 relative to the fixed plate 41, and the movement distance of the cavity mold 31 is determined (specified) with high precision. Moreover, the fixed plate 41 can be fixed in a state where it is rotated a given angle relative to the lower support plate 38. Therefore, for the preform 10 which is supported by the neck mold 27 and cannot rotate on its own, the circumferential part that is to be heated can be aligned with the cavity mold 31.

[0057] (Blow Molding Section 23)

[0058] The blow molding section 23 stretches and blow molds the pre-plasticized preform 10, which has been temperature-adjusted by the temperature adjustment section 22, to manufacture a container.

[0059] The blow molding section 23 includes a pair of parting dies corresponding to the shape of the container, namely a blow molding cavity mold and a bottom mold, a stretching rod, and an air inlet component (all not shown). The blow molding section 23 performs blow molding while stretching the pre-plasticized preform 10. As a result, the pre-plasticized preform 10 can be shaped into the shape of the blow molding cavity mold to manufacture a container.

[0060] (Removal section 24)

[0061] The removal section 24 is configured to release the neck of the container manufactured by the blow molding section 23 from the neck mold 27 and remove the container to the outside of the blow molding apparatus 20.

[0062] <Explanation of Blow Molding Method>

[0063] Next, the blow molding method of the blow molding apparatus 20 of the first embodiment will be described.

[0064] Figure 7This is a flowchart illustrating the steps of the blow molding method. In the first embodiment, before each step (S101 to S104) of the blow molding method described later, a temperature adjustment step (S100) is performed to adjust the position of the mold of the temperature adjustment unit 22 based on the results of test operation.

[0065] (Step S100: Temperature Adjustment Process)

[0066] The temperature adjustment process (temperature adjustment cavity mold position adjustment process) is a process of adjusting the position of the cavity mold 31 of the temperature adjustment unit 22 according to the temperature distribution of the preform 10 injection molded during test operation or the wall thickness distribution of the container blow molded during test operation.

[0067] First, the blow molding apparatus 20 is tested to obtain information on the temperature distribution of the preform 10 or the wall thickness distribution of the container before adjustment. If the test results show that the temperature distribution of the preform 10 or the wall thickness distribution of the container differs from the desired state, the position of the cavity mold 31 in the temperature adjustment unit 22 is adjusted as follows. In the following description, as an example, the adjustment is made to reduce the deviation of the temperature distribution of the preform 10 or the wall thickness distribution of the container in the circumferential direction.

[0068] For example, if there is a temperature distribution deviation in the circumferential direction of the main body 13 of the preform 10, the operator removes the upper support plate 37, the cavity mold 31, and the pressing member 44. Alternatively, the pressing member 44 is removed, and the upper support plate 37, the cavity mold 31, the spacer 49, the movable plate 42, and the fixed plate 41 are loosened to a position that allows for adjustment. Then, the fixed plate 41 is rotated relative to the lower support plate 38 so that the circumferential position of the main body 13 of the preform 10, where there is a temperature deviation, is positioned on the extension line of the long axis (long side direction) of the cam hole 41c of the fixed plate 41.

[0069] Next, the operator rotates the movable plate 42 of the position adjustment mechanism 40 to adjust the position of the shaft portion 34a held in the cam hole 41c of the fixed plate 41. At this time, by adjusting the position of the shaft portion 34a held by the position adjustment mechanism 40, the distance between the high-temperature part of the preform 10 and the cavity mold 31 is widened (reducing the amount of heating), and the distance between the low-temperature part of the preform 10 and the cavity mold 31 is brought closer (increasing the amount of heating). As a result, the high-temperature parts of the preform 10 in the circumferential direction during test operation are less likely to be heated by the cavity mold 31, and the deviation of the circumferential temperature distribution of the preform 10 can be reduced. In addition, by rotating the fixed plate 41 relative to the lower support plate 38 by a given angle and fixing it, the circumferential part of the preform 10 that needs to be heated can be reliably aligned with the cavity mold 31. Alternatively, the position adjustment (distance adjustment) of the cavity mold 31 and the pre-plasticized blank 10 can also be performed by the following method: only the pressing member 44 is removed, and the movable plate 42 is rotated to adjust the distance between the cavity mold 31 and the pre-plasticized blank while the shaft part 34a of the cavity mold 31 is inserted through the elongated hole 42c of the movable plate 42 and the cam hole 41c of the fixed plate. Then, the pressing member 44 is used to fix it again.

[0070] In addition, when making various adjustments in the temperature adjustment process based on the wall thickness distribution of the container manufactured during test operation, it can be done in the following manner.

[0071] In one-stage blow molding, the high-temperature regions of the preform 10 retain a large amount of heat, making it easy to stretch. That is, the thinner-walled regions of the container correspond to the high-temperature regions of the preform 10. Conversely, the low-temperature regions of the preform 10 retain less heat compared to the high-temperature regions, making it difficult to stretch. That is, the thicker-walled regions of the container correspond to the low-temperature regions of the preform 10.

[0072] Therefore, in the case of various adjustments in the temperature adjustment process based on the wall thickness distribution of the container, it is sufficient to regard the thinner parts of the container wall as the parts with higher temperature of the preform 10 and the thicker parts of the container wall as the parts with lower temperature of the preform 10, and make the adjustments in the same way as described above.

[0073] Once the above-mentioned temperature adjustment process is completed, execute the following blow molding cycle processes.

[0074] (Step S101: Injection Molding Process)

[0075] In step S101, in the injection molding section 21, resin is injected from the injection device 25 into the mold space of the preform shape formed by the injection cavity mold, the injection core mold and the neck mold 27 of the conveying mechanism 26 to manufacture the preform 10.

[0076] In step S101, when the injection molding of the preform 10 is completed, the injection molding section 21 is opened to demold the preform 10 from the injection cavity mold and the injection core mold. Then, the transfer plate of the conveying mechanism 26 moves by rotating a given angle, and the preform 10 held in the neck mold 27 is conveyed to the temperature adjustment section 22.

[0077] (Step S102: Temperature Adjustment Process)

[0078] Next, in the temperature adjustment unit 22, temperature adjustment is performed to bring the temperature of the preform 10 close to the temperature suitable for final blow molding.

[0079] like Figure 2 As shown, in the temperature adjustment process, the preform 10 is housed in the temperature adjustment space of the cavity mold 31. In addition, since the shape of the cavity mold 31 corresponds to that of the preform 10, the shape of the preform remains unchanged during the temperature adjustment process.

[0080] In the temperature adjustment process, by positioning the preform 10 facing the cavity mold 31, the temperature of the preform 10 is adjusted to a temperature below that suitable for blow molding, thereby reducing the temperature deviation during injection molding. In particular, in the first embodiment, since the position of the cavity mold 31 is appropriately adjusted by the position adjustment mechanism 40 in the temperature deviation adjustment process (S100), the circumferential temperature deviation of the preform 10 can be reduced.

[0081] After the temperature adjustment process, the transfer plate of the conveying mechanism 26 moves by rotating a given angle, and the pre-plasticized preform 10, which has been temperature adjusted and is held in the neck mold 27, is conveyed to the blow molding section 23.

[0082] (Step S103: Blow molding process)

[0083] Next, the container is blow-molded in the blow molding section 23.

[0084] First, the blow molding cavity mold is closed, housing the preform 10 within the mold space. The air inlet member (blow molding core) is lowered, bringing it into contact with the neck of the preform 10. Then, the tension rod (longitudinal tension member) is lowered, pressing the bottom of the preform 10 from its inner surface. While performing longitudinal tension as needed, blow molding air is supplied from the air inlet member, thereby performing transverse tension on the preform 10. As a result, the preform 10 bulges out and fits tightly against the mold space of the blow molding cavity mold, thus being shaped and blow-molded into a container. Furthermore, the bottom mold remains in a position below the bottom of the preform 10 before the blow molding cavity mold closes, and rapidly rises to the molding position before or after mold closing.

[0085] (Step S104: Container Removal Process)

[0086] When the blow molding process is complete, the blow molding cavity mold and the bottom mold are opened. As a result, the container can be moved from the blow molding section 23.

[0087] Next, the transfer plate of the conveying mechanism 26 moves by rotating a given angle, and the container is conveyed to the take-out section 24. In the take-out section 24, the neck of the container is released from the neck mold 27, and the container is taken out of the blow molding apparatus 20.

[0088] The above completes the series of processes in the blow molding cycle. Then, by moving the transfer plate of the conveyor mechanism 26 by rotating it at a given angle, the processes S101 to S104 described above are repeated. While the blow molding apparatus 20 is operating, the manufacturing of four sets of containers, each with a time difference of one process, is performed in parallel.

[0089] The effects of the first embodiment will be explained below.

[0090] The blow molding apparatus 20 of the first embodiment includes a position adjustment mechanism 40 for adjusting the position of the cavity mold 31 of the temperature adjustment unit 22. The position adjustment mechanism 40 includes: a fixed plate 41 having a linear cam hole 41c for receiving a shaft portion 34a of the cavity mold 31; and a movable plate 42, which overlaps with the fixed plate 41 in the extending direction of the shaft portion 34a and rotates relative to the fixed plate 41 along a plane. The movable plate 42 has an elongated hole 42c that intersects the cam hole 41c in the planar direction and, together with the cam hole 41c, positions the shaft portion 34a. Furthermore, by rotating the movable plate 42, the position where the cam hole 41c intersects with the elongated hole 42c moves along the long side direction of the cam hole 41c.

[0091] When adjusting the position of the mold using set screws or similar devices, it is necessary to individually adjust the horizontal position of each layer constituting the cavity mold 31 (e.g., upper mold 32, middle mold 33, and lower mold 34) before connecting (fixing them), making the position adjustment operation cumbersome. On the other hand, in the position adjustment mechanism 40 of the first embodiment, by rotating the movable plate 42 relative to the fixed plate 41, the position of the shaft portion 34a of the cavity mold 31, which is held, moves along the cam hole 41c. Therefore, according to the first embodiment, by simply adjusting the position of the movable plate 42, the appropriate position adjustment of the cavity mold 31 relative to the preform 10 can be performed with good workability, and the circumferential temperature adjustment (heating degree) of the preform 10 can be achieved with high precision. That is, by simply rotating the fixed plate 41 and the movable plate 42 relative to each other in the horizontal direction, the circumferential temperature adjustment of the preform 10 can be performed with high precision. Furthermore, according to the first embodiment, by marking the position of the movable plate 42 relative to the fixed plate 41, the adjusted position of the cavity mold 31 can be easily restored, thereby ensuring the reproducibility of the temperature adjustment conditions (heating conditions) for the preform 10.

[0092] In the first embodiment, the position adjustment mechanism 40 has a fixed plate 41 and a movable plate 42 overlapping each other in the extension direction (elongation direction) of the shaft portion 34a. Therefore, the projected area of ​​the position adjustment mechanism 40 and the cavity mold 31 in a top view is very small. Thus, in the first embodiment, when multiple or multiple rows of cavity molds 31 are arranged in the blow molding apparatus 20, it is easy to reduce the spacing between them to arrange the cavity molds 31, which can save space when molding multiple cavity molds at the same time, and easily increase the number of containers that can be manufactured in one blow molding cycle.

[0093] Furthermore, when mechanisms such as set screws are arranged on the side of the mold, it is difficult to reduce the spacing between them when arranging the mold. Although it is possible to reduce the spacing between the molds by arranging multiple set screws diagonally, the operability of adjusting the mold position is significantly reduced in the above-described structure. The first embodiment is advantageous in that it avoids these problems.

[0094] Second Implementation Method

[0095] The second embodiment is a variation of the first embodiment, and is a structure provided with a positioning part consisting of a fixed plate 41 and a movable plate 42. The positioning part in the second embodiment consists of a plunger 46 that moves a locking piece 46a on the fixed plate 41 side and a receiving groove 43 that serves as a receiving part for receiving the locking piece on the movable plate 42 side. The structures of the fixed plate 41 and the movable plate 42 of the position adjustment mechanism 40 in the second embodiment differ from those in the first embodiment. Therefore, in the description of the second embodiment, the same symbols are used for structures identical to those in the first embodiment, and repeated descriptions are omitted.

[0096] Figure 8 (a) is a top view of the movable plate 42 according to the second embodiment. In the movable plate 42 of the second embodiment, at least two, for example five, recessed receiving grooves 43 are formed on the lower surface (bottom surface) side of the movable plate body 42a and on the cylindrical protrusions 42b, serving as receiving portions. The receiving grooves 43a-43e are arranged along the outer periphery of the cylindrical protrusions 42b, and each receiving groove 43a-43e receives the locking piece 46a on the side of the fixed plate 41, which will be described later. In addition, a cut (first marking portion) 47 for marking the alignment with the fixed plate 41 is formed on the outer periphery of the movable plate body 42a. Furthermore, the structure and function of the protrusions 42b and the elongated holes 42c are the same as in the first embodiment. The shape of the cut (first marking portion) 47 is preferably... Figure 8 It can be a cut-out shape like (a), but it can also be a convex shape protruding from the outer periphery of the movable plate body 42a.

[0097] Figure 8 (b) is a top view of the fixing plate 41 of the second embodiment. In the fixing plate 41 of the second embodiment, a plunger (locking member) 46 is embedded in the inner peripheral surface of the recess 41b. The plunger 46 has a spherical locking piece 46a, for example, which is exerted with force on the inside of the recess 41b by a spring (not shown). Alternatively, the locking piece 46a may be pin-shaped.

[0098] With the movable plate 42 and the fixed plate 41 overlapping vertically, the protrusion 42b of the movable plate 42 is axially supported by the recess 41b of the fixed plate 41, allowing the movable plate 42 to rotate about the protrusion 42b and the recess 41b as rotation axes. Alternatively, the protrusion 42b of the movable plate 42 can be embedded in the recess 41b of the fixed plate 41, and the protrusion 42b can be rotated relative to the recess 41b while its outer peripheral surface abuts against the inner peripheral surface of the recess 41b, thereby causing the movable plate 42 to rotate.

[0099] Here, when the plunger 46 overlaps with any of the receiving grooves 43a-43e in the circumferential direction, the locking piece 46a, which is forceped towards the inside of the recess 41b, engages with the receiving groove of the protrusion 42b, and the movable plate 42 is positioned relative to the fixed plate 41. Thus, at the five positions where the receiving grooves 43a-43e overlap with the plunger 46, the movable plate 42 is positioned relative to the fixed plate 41. Furthermore, by applying a force in a given or greater rotational direction to the movable plate 42, the spring of the plunger 46 is compressed due to elastic deformation, and the locking piece 46a retracts outward, thereby easily releasing the locking piece 46a from the receiving grooves 43a-43e.

[0100] Additionally, at least two, for example five, cuts (second markings) 48 (48a-48e) are formed on the outer periphery of the fixed plate 41 for alignment with the cuts (first markings) 47 of the movable plate 42. Cut 48a is formed at a position where it overlaps with cut 47 when the locking piece 46a is engaged with the receiving groove 43a. Cut 48b is formed at a position where it overlaps with cut 47 when the locking piece 46a is engaged with the receiving groove 43b. Cut 48c is formed at a position where it overlaps with cut 47 when the locking piece 46a is engaged with the receiving groove 43c. Cut 48d is formed at a position where it overlaps with cut 47 when the locking piece 46a is engaged with the receiving groove 43d. Cut 48e is formed at a position where it overlaps with cut 47 when the locking piece 46a is engaged with the receiving groove 43e. Furthermore, the shape of the cuts (second markings) 48 is preferably... Figure 8 It can be a cut-out shape like (b), but it can also be a convex shape protruding from the outer periphery of the fixing plate 41.

[0101] Furthermore, the fixing plate 41 has a plurality of pin holes 41d spaced at constant intervals in the circumferential direction. The pin holes 41d of the fixing plate 41 receive positioning pins (not shown) that pass through the lower support plate 38 and are inserted from below. In this way, the fixing plate 41, which is disposed on the lower support plate 38, is positioned on the lower support plate 38 by the positioning pins. As a result, the circumferential position of the main body 13 of the preform 10, which has a temperature deviation, can be positioned with high precision without positional offset along the extension line of the long axis (long side direction) of the cam hole 41c of the fixing plate 41. Moreover, by moving the cavity mold 31 as described later, the temperature state of the main body 13 can be appropriately adjusted before blow molding.

[0102] Figure 9 Figures (a)-(e) are diagrams showing the rotational states of the movable plate 42 and the fixed plate 41 in the second embodiment. Figure 9 (a) to Figure 9 (e) shows the change when the movable plate 42 is rotated clockwise. With the movable plate 42 rotated, first remove the cavity mold 31, then remove the pressing member 44 and spacer 49 of the position adjustment mechanism 40 for adjustment. Alternatively, the pressing member 44 can be removed, and the upper support plate 37, cavity mold 31, spacer 49, movable plate 42, and fixed plate 41 can be loosened to a degree that allows for position adjustment.

[0103] exist Figure 9 In (a), the locking piece 46a engages with the receiving groove 43a, and the cutout 47 is located at a position overlapping with the cutout 48a. Furthermore, the elongated hole 42c of the movable plate 42 is arranged to intersect with the cam hole 41c of the fixed plate 41. Therefore, in Figure 9In state (a), when the shaft portion 34a of the lower mold 34 is inserted into the movable plate 42 and the fixed plate 41, the shaft portion 34a is positioned by being constrained by the inner surface of the short side direction of the cam hole 41c and the inner surface of the short side direction of the elongated hole 42c that intersects the cam hole 41c.

[0104] When from Figure 9 (a) When the movable plate 42 rotates clockwise, it becomes Figure 9 The state of (b). Figure 9 In (b), the locking piece 46a is engaged with the receiving groove 43b, and the cut 47 is located at a position overlapping with the cut 48b. Additionally, in Figure 9 In (b), the shaft portion 34a is held in the same position as... Figure 9 (a) moves to the upper side of the graph compared to (a).

[0105] When from Figure 9 (b) When the movable plate 42 rotates clockwise, it becomes Figure 9 The state of (c). In Figure 9 In (c), the locking piece 46a is engaged with the receiving groove 43c, and the cut 47 is located at a position overlapping with the cut 48c. Additionally, in Figure 9 In (c), the shaft portion 34a is held in the same position as... Figure 9 Compared to (b), it moves to the upper side of the figure.

[0106] When from Figure 9 When (c) causes the movable plate 42 to rotate clockwise, it becomes Figure 9 The state of (d). In Figure 9 In (d), the locking piece 46a is engaged with the receiving groove 43d, and the cut 47 is located at the position overlapping with the cut 48d. Additionally, in Figure 9 In (d), the shaft portion 34a is held in the same position as... Figure 9 (c) moves to the upper side of the diagram.

[0107] When from Figure 9 When (d) causes the movable plate 42 to rotate clockwise, it becomes Figure 9 The state of (e). In Figure 9 In (e), the locking piece 46a is engaged with the receiving groove 43e, and the cut 47 is located at a position overlapping with the cut 48e. Additionally, in Figure 9 In (e), the shaft portion 34a is held in the same position as... Figure 9 (d) moves to the upper side of the diagram.

[0108] In addition, whenever the locking position of the locking piece 46a and the receiving groove 43 is moved to an adjacent position, that is, whenever the overlapping position of the cut (first marking part) 47 and the cut (second marking part) 48 is moved to an adjacent position, the shaft part 34a or the cavity mold 31 moves (approaches or moves away) a constant distance (e.g., 0.3 mm or 0.5 mm) relative to the main body 13 of the preform 10.

[0109] in addition, Figure 10 (a)-(e) are cross-sectional views showing the positional relationship between the middle mold 33 and the preform 10. Figure 10 (a)-(e) respectively correspond to Figure 9 The position of shaft 34a of (a)-(e) is adjusted.

[0110] In Figure 9 (a) corresponds to Figure 10 In (a), the preform 10 is concentrically arranged in the center of the middle mold 33. In contrast, as... Figure 9 As shown in (b)-(e), the position of the shaft portion 34a is moved upwards in the figure, thereby, in Figure 10 In (b)-(e), the position of the cavity mold 31 (intermediate mold 33) also moves upward in the figure. On the other hand, since the position of the preform 10 is constant, the preform 10 becomes eccentrically configured relative to the cavity mold 31 (intermediate mold 33) along with the movement of the cavity mold 31 that accompanies the position adjustment of the shaft portion 34a.

[0111] In addition, the eccentricity of the cavity mold 31 relative to the preform 10 is Figure 10 The largest of (e), according to Figure 10 (d) Figure 10 (c) Figure 10 The order of (b) decreases, in Figure 10 In (a), the eccentricity is zero.

[0112] As described above, according to the second embodiment, by engaging the plunger 46 with any one of the receiving grooves 43a-43e, the rotatable movable plate 42 is positioned relative to the fixed plate 41 at a given position. Therefore, in the temperature adjustment process, the eccentricity of the cavity mold 31 relative to the preform 10 (i.e., the degree of circumferential heating of the preform 10) can be adjusted with high precision through simple operation, and the reproducibility of adjusting the eccentricity can be improved. Furthermore, in the second embodiment, by aligning the cuts 47 with the cuts 48a-48e, the operator can also confirm the eccentricity of the position adjustment mechanism 40, thus improving the workability in the temperature adjustment process.

[0113] This invention is not limited to the above-described embodiments. Various improvements and design changes can be made without departing from the spirit of this invention.

[0114] The structure of the cavity mold 31 in the above embodiment is an example and is not limited to the above embodiment. In addition, the blow molding apparatus 20 in the above embodiment may also be a structure having multiple injection molding sections (a so-called 5-station type structure). In this case, it may also be a structure in which a temperature adjustment section is further added between the injection molding sections (a so-called 6-station type structure).

[0115] Furthermore, the structure of the fixed plate 41 and movable plate 42 in the above embodiment is only one example. For example, a protrusion may be formed on the side of the fixed plate 41, and a recess may be formed on the side of the movable plate 42. Moreover, the movable plate 42 and the fixed plate 41 can rotate complementaryly as long as the protrusion and the recess are able to rotate, and their shapes do not have to be disc-shaped but polygonal. Similarly, the outer diameter of the pressing member 44 can be as long as it can hold the movable plate 42 and the fixed plate 41, and it can also be a polygonal split member with a hollow area on the lower side.

[0116] In addition, it can also be used not only to eliminate the overheating of the main body of the preform, but also to locally heat a portion of the circumferential part of the main body of the preform to form a flat container.

[0117] Furthermore, the embodiments disclosed herein should be considered illustrative in all respects, and not restrictive. The scope of the invention is not shown by the foregoing description, but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0118] Symbol Explanation

[0119] 10…Pre-plasticized preform, 20…Blow molding device, 21…Injection molding section, 22…Temperature adjustment section, 23…Blow molding section, 31…Cavity mold, 34a…Shaft section, 40…Position adjustment mechanism, 41…Fixed plate, 41a…Fixed plate body, 41b…Recess, 41c…Cam hole, 42…Modible plate, 42a…Modible plate body, 42b…Protrusion, 42c…Elongated hole.

Claims

1. A mold comprising a position adjustment mechanism that receives a shaft extending from a cavity mold housing a preform and adjusts the position of the cavity mold held in a plane intersecting the extending direction of said shaft. The position adjustment mechanism includes: The first component has a straight cam hole for receiving the shaft portion; and A second component, which overlaps with the first component in the extension direction of the shaft portion, and rotates relative to the first component along the plane. The second component has an elongated hole that intersects the cam hole in the planar direction and, together with the cam hole, positions the shaft portion. As the second component rotates, the position where the cam hole intersects with the elongated hole moves along the long side of the cam hole.

2. The mold according to claim 1, wherein, The second component rotates about a position offset from the center of the cam hole.

3. The mold according to claim 1, wherein, One of the first and second components has a cylindrical protrusion eccentrically located from the center of the component in the planar direction. The other of the first and second components has a bottomed cylindrical recess that rotatably receives the protrusion. The second component rotates about the convex portion and the concave portion as the rotation axis.

4. The mold according to claim 3, wherein, The other of the first and second components has a locking tab on the inner circumferential surface of the recess that is capable of elastic deformation. One of the first and second components has receiving portions at multiple locations in the circumferential direction, which receive the locking tab at the outer periphery of the protrusion. The second component is positioned relative to the first component by being engaged with the receiving portion by the locking tab.

5. The mold according to any one of claims 1 to 4, wherein, The cavity mold is a temperature adjustment mold used to adjust the temperature of the preform, which retains heat during injection molding. The distance between the temperature adjustment mold and the preform is adjusted by adjusting the position of the shaft.

6. A blow molding apparatus, comprising: Injection molding section, which injection molds preforms made of resin; A temperature adjustment unit adjusts the temperature of the preform, which retains heat during injection molding; and The blow molding section blow molds the pre-plasticized preform under a temperature-adjusted condition to manufacture resin containers. The temperature adjustment unit has the mold as described in claim 5.

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