Hot runner mold and resin-made container manufacturing apparatus

Abstract

The present invention relates to a hot runner mold and a resin-made container manufacturing apparatus. The hot runner mold includes a hot runner mold main body portion fixed to a fixing plate and supplying molten resin received from a resin inlet to an injection mold; a nozzle receiving portion obliquely arranged from a position orthogonal to the resin inlet of the hot runner mold main body portion and coaxially connected to a nozzle of an injection device supplying the molten resin; a relay portion having a resin flow path with a bent portion inside and guiding the molten resin from the nozzle receiving portion to the resin inlet; and a restriction portion fixed to the fixing plate and restricting movement of the nozzle receiving portion or the relay portion relative to the hot runner mold main body portion.

Description

Technical Field

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

[0002] Previously, a type of resin-based release container was known, which had a double-layered structure with an inner and outer layer, the inner layer peeling off from the outer layer as the contents were discharged. This type of release container was also called a layered bottle or vacuum bottle, and was used, for example, as a container for condiments such as soy sauce or cosmetic liquids.

[0003] Currently, in the manufacturing of such peelable containers, extrusion blow molding is commonly used, while stretch blow molding is rarely used (see Patent Document 1).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 5267901 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] For example, from the perspective of improving the appearance, dimensional accuracy, and physical strength of release containers, and reducing environmental impact by suppressing unnecessary materials, research is being conducted on the application of hot preform blow molding, a one-step hot preform blow molding method and blow molding machine (one-step blow molding method, one-step blow molding machine) in the manufacture of release containers, which involves a continuous process from injection molding to blow molding.

[0009] Typically, a one-step blow molding machine comprises a four-station structure consisting of an injection molding section, a temperature control section, a blow molding section, and a take-off section, or a three-station structure that omits the temperature control step. These three or four molding stations are arranged in a roughly equilateral triangular or square shape on the lower base of the molding machine. Preforms or containers are fed to these molding stations by the intermittent rotation of a rotary plate equipped with a neck mold.

[0010] In the injection molding section, the injection mold and the hot runner mold are arranged adjacent to the injection unit. The resin material, plasticized / molten by the injection unit, is injected and introduced into the molding space of the injection mold via the hot runner mold. At this time, the nozzle of the injection unit is positioned in close contact with the sprue (resin inlet) of the hot runner mold to prevent resin leakage. Furthermore, the hot runner mold is heated to a temperature above the melting point of the resin material to prevent the resin material flowing inside from solidifying.

[0011] Furthermore, in one-step blow molding machines, multiple preforms are injection molded simultaneously to increase container production. Therefore, the injection capacity (amount of molten resin) per injection increases. To ensure this large injection capacity, the injection unit needs to be longer (larger). If there are three or four molding stations, the injection unit can be configured orthogonally to the hot runner, with the sprue and nozzle arranged in a straight line. In this case, adjusting the position of the injection unit and the nozzle contact force, taking into account the thermal expansion of the hot runner, is easier, and the overall installation area (space occupied) of the molding machine is also reduced.

[0012] In a one-step blow molding machine that performs two-layer molding, two injection molding sections are required, resulting in a 5- or 6-station structure. These stations are arranged in a roughly pentagonal or hexagonal shape on the lower base. Therefore, if the two injection units are arranged orthogonally to the front of the hot runner mold as before, the injection units would extend obliquely from the two faces of the pentagon or hexagon. This increases the overall installation area of ​​the molding machine, and depending on the situation, it may become too small to fit entirely into the delivery container. Therefore, it is desirable to have a structure in which the two injection units are arranged parallel and at an angle relative to the front of the hot runner.

[0013] However, in structures where the hot runner's sprue and the injection nozzle are not aligned in a straight line but are arranged at an angle, adjusting the positions of the components and optimizing the nozzle contact force becomes difficult. Therefore, resin leakage is prone to occur between the sprue and the nozzle. Furthermore, if the nozzle contact force is increased to suppress resin leakage, the hot runner mold and injection cavity mold will be pressed down by the injection unit, causing tilting and positional displacement relative to the lower base, which will also lead to uneven thickness of the preform.

[0014] Therefore, the present invention was made in view of such a problem, and its object is to provide a hot runner mold that can suppress resin leakage and form a well-formed preform even when the injection device is arranged at an angle from a position orthogonal to the front of the hot runner.

[0015] Technical solutions for solving the problem

[0016] A hot runner mold according to one aspect of the present invention comprises: a hot runner mold body fixed to a fixed plate and supplying molten resin received from a resin inlet to an injection mold; a nozzle receiving portion disposed obliquely from a position orthogonal to the resin inlet of the hot runner mold body and coaxially connected to the nozzle of an injection device supplying molten resin; a relay portion having a resin flow path with a bend inside, guiding molten resin from the nozzle receiving portion to the resin inlet; and a limiting portion fixed to the fixed plate, limiting the movement of the nozzle receiving portion or the relay portion relative to the hot runner mold body.

[0017] Invention Effects

[0018] According to one aspect of the invention, when the injection device is configured at an angle from a position orthogonal to the front of the hot runner, it is also possible to suppress resin leakage and form a well-formed preform. Attached Figure Description

[0019] Figure 1 This is a diagram schematically illustrating the structure of the blow molding apparatus of this embodiment.

[0020] Figure 2 This is a diagram illustrating the manufacturing process of the preform according to this embodiment.

[0021] Figure 3 (a) is a view showing the area near the bottom of the first layer in the first injection molding section, and (b) is a view showing the area near the bottom of the preform in the second injection molding section.

[0022] Figure 4 This is a diagram showing an example of the structure of the connection between the hot runner mold and the injection device.

[0023] Figure 5 It is shown Figure 4 A diagram of the structure on the side.

[0024] Figure 6 It is shown Figure 4 Another variation of the diagram.

[0025] Figure 7 yes Figure 6 Side view.

[0026] Figure 8 This is a longitudinal sectional view of the preform in this embodiment. Detailed Implementation

[0027] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0028] In the embodiments, for ease of understanding and explanation, structures and elements other than the main parts of the invention are simplified or omitted in the description. Furthermore, in the accompanying drawings, the same elements are labeled with the same reference numerals. Additionally, the shapes, dimensions, etc., of the elements shown in the drawings are schematic representations and do not represent actual shapes, dimensions, etc.

[0029] <Description of the manufacturing apparatus for the stripping container>

[0030] Figure 1This diagram schematically illustrates the structure of the blow molding apparatus 30 of this embodiment. The blow molding apparatus 30 of this embodiment is an example of a manufacturing apparatus for a release container, which employs a hot preform method (also known as a one-step method) to blow mold the release container without cooling the preform 10 to room temperature by effectively utilizing the heat retained during injection molding (internal heat).

[0031] The blow molding apparatus 30 of this embodiment uses two-stage injection molding, such as... Figure 8 As shown, a preform 10 has a double-layer structure, with a second layer (inner layer) 12 stacked inside the first layer (outer layer) 11. The preform 10 has an overall cylindrical shape with one open end and the other closed end. The preform 10 includes a cylindrical body 14, a bottom 15 closing the other end of the body 14, and a neck 13 with an opening at one end of the body 14. Furthermore, in the bottom 15 of the preform 10, an opening 16 is formed through the first layer 11 at its center. The opening 16 of the first layer 11 is sealed from the inside by the second layer 12.

[0032] Furthermore, the following description illustrates the case where the first layer 11 is injection molded first, and then the second layer 12 is injection molded inside the first layer 11. However, when forming a preform 10 with a double-layer structure, the second layer 12 may be injection molded first, and then the first layer 11 may be injection molded outside the second layer 12.

[0033] return Figure 1 The blow molding apparatus 30 includes a first injection molding unit 31, a first temperature adjustment unit 32, a second injection molding unit 33, a second temperature adjustment unit 34, a blow molding unit 35, a take-out unit 36, and a conveying mechanism 37. The first injection molding unit 31, the first temperature adjustment unit 32, the second injection molding unit 33, the second temperature adjustment unit 34, the blow molding unit 35, and the take-out unit 36 ​​are positioned at a position that rotates by the same predetermined angle (e.g., 60 degrees) around the conveying mechanism 37 each time. Alternatively, the blow molding apparatus 30 may be configured to omit the first temperature adjustment unit 32 (in which case, each molding station is positioned at a position that rotates by 72 degrees around the conveying mechanism 37 each time). Furthermore, a core mold lifting mechanism (not shown) is provided above the conveying mechanism 37 in the first injection molding unit 31 and the second injection molding unit 33.

[0034] (Conveying mechanism 37)

[0035] Conveying mechanism 37 is equipped with Figure 1A rotating plate (transfer plate) 37a rotates around an axis perpendicular to the paper surface. A neck mold 37b holds the neck 13 (or the neck of the peeling container) of the preform 10 on the rotating plate 37a. Figure 1 (Not shown in the diagram) One or more are arranged at predetermined angles. The conveying mechanism 37, by rotating the rotating plate 37a, sequentially conveys the preform 10 (or release container) held by the neck mold 37b to the first injection molding section 31, the first temperature adjustment section 32, the second injection molding section 33, the second temperature adjustment section 34, the blow molding section 35, and the take-off section 36. In addition, the conveying mechanism 37 can also raise and lower the rotating plate 37a, and also perform the actions involved in mold closing and mold opening (demolding) in the first injection molding section 31 and the second injection molding section 33.

[0036] (First Injection Molding Section 31)

[0037] The first injection molding unit 31 includes a cavity mold 40, a core mold 41, and a hot runner mold (or hot runner device) 42, and cooperates with the neck mold 37b conveyed during molding to manufacture the first layer 11 of the preform 10. The cavity mold 40 is composed of a first cavity mold 40A on the opening side (upper side) and a second cavity mold 40B on the bottom side (lower side). A first injection device 38 that supplies the first resin material to the hot runner mold 42 is connected to the first injection molding unit 31. The cavity mold 40 and the hot runner mold 42 are fixed to the machine base of the blow molding apparatus 30 in an integrated state. The core mold 41 is fixed to the core mold lifting mechanism.

[0038] Figure 2 (a) and (b) show the first injection molding section 31 that forms the first layer 11 of the preform 10 of this embodiment. Figure 3 (a) is a diagram showing the area near the bottom of the first layer 11 in the first injection molding section 31.

[0039] Cavity mold 40 defines the shape of the outer periphery of the first layer 11. First cavity mold 40A is the mold facing the opening side of cavity mold 40 (the side that abuts against neck mold 37b when closed), defining the shape of the outer periphery of the body of the first layer 11. Second cavity mold 40B is the mold facing the bottom side of cavity mold 40 (the side that abuts against hot runner mold 42), defining the shape of the bottom outer periphery of the first layer 11. Second cavity mold 40B also includes a gate portion 40Ba for guiding resin material from hot runner mold 42 to the cavity surface. Additionally, hot runner mold 42 has a resin supply portion 42a for introducing the first resin material, plasticized (molten) in the first injection device 38, into cavity mold 40. Core mold 41 is the mold defining the shape of the inner periphery of the first layer 11, inserted from above into the inner periphery of cavity mold 40. In addition, the neck mold 37b conveyed during molding specifies the shape of the neck 13 of the preform 10 (first layer 11).

[0040] like Figure 2 As shown in (a) and (b), in the first injection molding section 31, the cavity mold 40, the core mold 41, and the neck mold 37b of the conveying mechanism 37 are closed to form a mold space for the first layer 11. Then, by allowing the first resin material to flow in from the bottom of the mold space through the hot runner mold 42, the first layer 11 of the preform 10 is manufactured in the first injection molding section 31.

[0041] On the upper surface (cavity side) of the second cavity mold 40B facing the bottom outer periphery of the first layer 11, a cylindrical (or conical cylindrical, prismatic) first protrusion 44 is provided at a predetermined position. At least one of the first protrusions 44 is arranged radially spaced apart from the bottom center where the resin supply section 42a is located. Figure 3 As shown in (a), the protrusion h1 of the first protrusion 44 from the cavity reference surface of the second cavity mold 40B (the cavity surface that defines the shape of the lower end of the bottom outer peripheral surface of the first layer 11) is almost the same as the thickness of the first layer 11. Therefore, when the first injection molding section 31 is closed, the top end of the first protrusion 44 faces the surface of the core mold 41 (located near the surface of the core mold 41). Thus, during the injection molding of the first injection molding section 31, the first protrusion 44 forms a circular or similar recess 11a in the first layer 11 at a position corresponding to the recess 17 of the preform 10. The recess 11a of the first layer 11 can either penetrate the first layer 11 or have a thin film formed by the core mold 41 and the first protrusion 44. Furthermore, the recess 11a of the first layer 11 formed by the first injection molding section 31 is also referred to as the first recess.

[0042] In addition, such as Figure 2 As shown in (b), a valve pin 43 (a rod-shaped component for opening and closing the resin supply section 42a) is provided in the resin supply section 42a of the hot runner mold 42, which can move axially upwards to a position close to the core mold 41. The valve pin 43 is housed inside the hot runner mold 42 before the first resin material is filled into the mold space, and after the first resin material is filled into the mold space, it protrudes to a position closer to the core mold 41 than the cavity-side opening end of the gate section 40Ba. By moving the valve pin 43 during injection molding in this way, a thin film section 18 of resin material with a wall thickness thinner than the peripheral portion can be formed at the bottom center of the first layer 11.

[0043] Furthermore, when the first injection molding section 31 is opened, the neck mold 37b of the conveying mechanism 37 remains closed and the first layer 11 of the preform 10 is conveyed as is. The number of preforms 10 simultaneously formed by the first injection molding section 31 (i.e., the number of release containers that can be simultaneously formed by the blow molding device 30) can be appropriately set.

[0044] (First temperature adjustment unit 32)

[0045] The first temperature adjustment unit 32 includes a temperature adjustment mold (not shown) for adjusting the temperature of the first layer 11 from the outside, and a heating rod, temperature adjustment rod, or air inlet rod for adjusting the temperature of the first layer 11 from the inside. The first temperature adjustment unit 32 cools (or heats) the first layer 11, which is in a high-temperature state after injection molding, by placing it in the temperature adjustment mold and maintaining it at a predetermined temperature. In addition, the first temperature adjustment unit 32 also functions to adjust the temperature distribution of the first layer 11 to a predetermined state before it is conveyed to the second injection molding unit 33.

[0046] (Second Injection Molding Section 33)

[0047] The second injection molding unit 33 includes a cavity mold 50, a core mold 51, and a hot runner mold 52. It cooperates with the neck mold 37b, which is conveyed during molding, to injection mold the second layer 12 onto the inner circumferential side of the first layer 11. The cavity mold 50 is composed of a first cavity mold 50A on the opening side (upper side) and a second cavity mold 50B on the bottom side (lower side). A second injection device 39, which supplies the second resin material to the hot runner mold 52, is connected to the second injection molding unit 33.

[0048] Figure 2 (c) shows the second injection molding section 33 for molding the second layer 12 of the preform 10. Figure 3 (b) is a diagram showing the area near the bottom of the preform 10 in the second injection molding section 33.

[0049] Cavity mold 50 is a mold that houses the first layer 11. First cavity mold 50A is the mold facing the opening side of cavity mold 50, housing the body of the first layer 11. Second cavity mold 50B is the mold facing the bottom side of cavity mold 50, housing the bottom of the first layer 11. Second cavity mold 50B also includes a gate portion 50Ba for guiding resin material from hot runner mold 52 to the cavity surface. Additionally, hot runner mold 52 has a resin supply portion 52a for introducing the second resin material plasticized (molten) in the second injection unit 39. Core mold 51 is a mold that defines the shape of the inner circumferential side of the second layer 12, inserted from above into the inner circumferential side of cavity mold 50. Furthermore, neck mold 37b, which is conveyed during molding, defines the upper end face (top surface) of the neck 13 of the preform 10 (second layer 12). Furthermore, hot runner mold 52 can also have a valve pin structure like hot runner mold 42.

[0050] like Figure 2As shown in (c), the second injection molding section 33 houses the first layer 11 of the preform 10 after injection molding by the first injection molding section 31. With the second injection molding section 33 closed, a mold space is formed between the inner circumferential side of the first layer 11 and the surface of the core mold 51. In the second injection molding section 33, a second resin material flows in from the bottom of the mold space via the hot runner mold 52, forming a preform 10 with a second layer 12 stacked on the inner circumferential side of the first layer 11.

[0051] Furthermore, on the upper surface (cavity side) of the second cavity mold 50B facing the bottom outer periphery of the first layer 11, a second protrusion 54, such as a cylinder, corresponding to the shape of the recess 17 of the preform 10, is provided at a predetermined position corresponding to the first protrusion 44 of the first injection molding part 31. When the second injection molding part 33 is received in the first layer 11, the second protrusion 54 is inserted into the recess 11a of the first layer 11. Thus, the basic structure of the protrusion in the second cavity mold 50B is almost the same as that of the second cavity mold 40B of the first injection molding part 31.

[0052] Here, as Figure 3 As shown in (b), the protrusion h2 of the second protrusion 54 from the cavity reference surface of the second cavity mold 50B (the cavity surface that abuts against the lower end side region of the bottom outer peripheral surface of the first layer 11) is a dimension larger than the thickness of the first layer 11. That is, the protrusion h2 of the second protrusion 54 is larger than the protrusion h1 of the first protrusion 44 (h2>h1). Therefore, when the second injection molding section 33 is closed, the top end of the second protrusion 54 penetrates the recess 11a of the first layer 11 and protrudes to the inner peripheral side of the first layer 11. By providing the second protrusion 54 in the second cavity mold 50B of the second injection molding section 33, a recess 17 can be formed in the bottom 15 of the preform 10.

[0053] Furthermore, the protrusion amount h2 of the second protrusion 54 is set to be smaller than the thickness of the preform 10. That is, during injection molding in the second injection molding section 33, the second resin material flows between the core mold 51 and the second protrusion 54, so a hole that penetrates the second layer 12 will not be formed due to the second protrusion 54.

[0054] (Second temperature adjustment unit 34)

[0055] The second temperature adjustment unit 34 includes a mold unit (not shown) for temperature adjustment (a heating tank or temperature adjustment tank (temperature regulating tank) for externally adjusting the temperature of the preform 10, and a heating rod, temperature regulating rod (temperature regulating rod), or air inlet rod for internally adjusting the temperature of the preform 10). The second temperature adjustment unit 34 homogenizes and removes temperature deviations by housing the preform 10, which is conveyed from the second injection molding unit 33, within the mold unit and maintaining it at a predetermined temperature, thereby adjusting the temperature of the preform 10 to a temperature suitable for final blow molding (e.g., approximately 90°C to 105°C). Furthermore, the second temperature adjustment unit 34 also functions to cool the preform 10 at its high temperature after injection molding.

[0056] (Blow molding section 35)

[0057] The blow molding section 35 blow molds the pre-plasticized preform 10 after temperature adjustment by the second temperature adjustment section 34 to manufacture a release container.

[0058] The blow molding section 35 includes a pair of parting dies corresponding to the shape of the release container, namely a blow molding cavity mold, a bottom mold, a stretching rod, and an air inlet component (all not shown). The blow molding section 35 performs blow molding while stretching the pre-plasticized preform 10. Thus, the pre-plasticized preform 10 can be shaped into the shape of the blow molding cavity mold to manufacture the release container.

[0059] (Removal section 36)

[0060] The removal section 36 is configured to open the neck of the release container manufactured by the blow molding section 35 from the neck mold 37b, and remove the release container to the outside of the blow molding apparatus 30.

[0061] (Configuration of injection molding equipment and hot runner mold)

[0062] In addition, such as Figure 1 As shown, in the blow molding apparatus 30, the first injection device 38 and the second injection device 39 are positioned along the long side of the apparatus ( Figure 1 The blow molding apparatus 30 is arranged side-by-side, extending in the left-right direction. In this case, the projected area of ​​the blow molding apparatus 30 from a top view is reduced, enabling miniaturization of the blow molding apparatus 30. Furthermore, in Figure 1 In the case of the structure, the first injection device 38 and the second injection device 39 are obliquely connected to the front of the corresponding injection molding part.

[0063] However, during injection molding, the hot runner mold of the injection molding section is heated to a predetermined temperature (e.g., 255°C) due to the inflow of molten resin, resulting in thermal expansion. The amount of this thermal expansion varies depending on the temperature of the hot runner mold.

[0064] For example, when the injection unit is positioned orthogonal to the front of the injection molding unit (the front of the hot runner mold with the runner), the nozzle of the injection unit (injection nozzle) is positioned opposite the expansion direction of the hot runner mold. In other words, according to this configuration, the direction in which the nozzle bearing of the hot runner mold moves due to thermal expansion acts approximately coaxially with the force generated at the nozzle of the injection unit due to the injection of molten resin and nozzle holding (the force exerted by the nozzle of the injection unit on the nozzle bearing). Therefore, in this configuration, it is easier to adjust the force during alignment and connection between the nozzle bearing of the hot runner mold and the nozzle of the injection unit, and it is less likely to cause leakage of molten resin at the connection between the hot runner mold and the injection unit.

[0065] However, as Figure 1 As shown by the dashed line, when the injection unit is obliquely connected to the front of the hot runner mold of the injection molding part, the nozzle of the injection unit is tilted relative to the expansion direction of the hot runner mold. That is, the direction of movement of the nozzle bearing portion of the hot runner mold due to thermal expansion is not coaxial with the force generated by the nozzle of the injection unit due to the injection of molten resin, nozzle holding, etc. (the force of the nozzle of the injection unit affecting the nozzle bearing portion). Therefore, in Figure 1 In the case of this structure, it is difficult to align (align) the nozzle receiving part of the hot runner mold with the nozzle of the injection device, and to adjust the force (nozzle contact force) when connecting the nozzle to the nozzle receiving part. It is also easy to cause leakage of molten resin at the connection between the hot runner mold and the injection device.

[0066] Figure 4 This is a diagram showing an example of the structure of a hot runner mold used to suppress resin leakage at the aforementioned connection. Figure 4 The structure of the hot runner mold shown is common in the first injection molding section and the second injection molding section.

[0067] The hot runner mold (or hot runner device) 42 (52) has at least a hot runner body (manifold) 62, a relay (relay block) 63, a runner (runner bushing) 69, and a hot runner fixing plate 64. The runner 69 has a first interface (first pipe head, first opening connector) 61 and a second interface (second pipe head, second opening connector) 65. The hot runner mold 42 (52) also has a bracket (connecting component, supporting component) 66 and a connecting pin 67.

[0068] Heating components (not shown), such as rod heaters and strip heaters, are provided in the hot runner body 62, relay section 63, and runner section 69. The hot runner body 62 is fixed to the hot runner fixing plate 64 via heat insulation components (not shown). In addition, multiple pressure plates (not shown) are erected on the hot runner fixing plate 64, forming a predetermined gap with the hot runner body 62 and surrounding the hot runner body 62, and abutting against the lower surface of the cavity mold 40 (50).

[0069] The sprue section 69 (more specifically, the first interface section 61) is a component that has a nozzle receiving section 61a at one end that receives the nozzle (not shown) of the injection device 38 (39), and is inserted into the second interface section 65 at the other end. Furthermore, the first interface section 61 has insertion portions for a plurality of connecting pins 67 arranged on the outer periphery of the nozzle receiving section 61a. In addition, the first interface section 61 and the second interface section 65 are arranged at an angle from a position orthogonal to the resin inlet 62b of the hot runner mold body section 62, and are connected substantially coaxially to the nozzle of the injection device.

[0070] The hot runner body 62 has branch flow paths (first runner section) 62a that distribute and supply molten resin to each cavity of the injection molding part 40 (50). The branch flow paths are formed from the side of the hot runner body 62 to the interior and the upper surface, and hot runner nozzles (not shown) communicating with each cavity are provided on the upper surface of the hot runner body 62.

[0071] The relay section 63 is a block that connects the resin inlet 62b of the hot runner body 62 to the gating section 69 (more specifically, the second interface section 65). The relay section 63 has a curved resin flow path (second flow path) internally, functioning to tilt the flow path connected to the second interface section 65 relative to the resin inlet of the hot runner body 62. The relay section 63 is fixed to the front side (the side with the protrusion 64a described later) of the hot runner body 62 in a manner that its resin flow path communicates with the resin inlet 62b and the branch flow path 62a. The relay section 63 is, for example, a generally cylindrical component with a first cut. The first cut is formed by obliquely cutting the side surface of the cylindrical component from the end face (circular surface) of the side that does not abut against the hot runner body 62. The gating section 69 (second interface section 65) is connected to the first cut.

[0072] Additionally, a hot runner mounting plate 64, which at least secures the hot runner main body 62, is installed on the outer (lower) side of the hot runner body 62 and the relay section 63. The hot runner mounting plate 64 has a protrusion 64a, which is approximately triangular in shape when viewed from above, on the mounting side of the relay section 63. The protrusion 64a is sized to include the relay section 63 when viewed from above, and a bracket 66 is mounted on one side of the protrusion 64a. Furthermore, the relay section 63 may also be fixed to the hot runner mounting plate 64 as needed.

[0073] The second interface section 65 is a component that allows the other end of the first interface section 61 to be inserted into on one side and is connected (fixed) to the flow path of the relay section 63 on the other side.

[0074] The bracket 66 is continuously provided with the protrusion 64a of the hot runner fixing plate 64, covering the connection portion between the relay section 63 and the second interface section 65. The bracket 66 has a rectangular (block-shaped) main body 66a facing the outer peripheral surface (or lower side) of the second interface section 65 and a rectangular (flat) connecting portion 66b connected to one end of the first interface section 61. A hole for receiving the connecting pin 67 is formed in the connecting portion 66b of the bracket 66. In addition, a through hole of a predetermined size is provided in the connecting portion 66b of the bracket 66, and the second interface is inserted with a gap between it and the inner surface of the through hole. This gap allows for positional changes in the second interface section 65 due to thermal expansion.

[0075] Here, the first interface portion 61 is configured to loosely engage with the connecting portion 66b of the bracket 66 via the connecting pin 67, allowing axial tilting relative to the bracket 66 and the second interface portion 65. Therefore, even in the event of deformation caused by thermal expansion of the hot runner mold, the relative movement of the first interface portion 61 and the second interface portion 65 (more specifically, the positional change of the first interface portion 61 in a predetermined direction between the second interface portion 65 and the nozzle) can properly maintain the connection between the nozzle of the injection device and the hot runner mold, suppressing leakage of molten resin. In other words, the first interface portion 61, the second interface portion 65, and the bracket 66 function as limiting portions that prevent inappropriate movement of the nozzle receiving portion 61a.

[0076] In addition, according to Figure 4 The structure does not require excessive nozzle contact force to suppress resin leakage. Therefore, it can suppress tilting and positional displacement relative to the lower base caused by the hot runner mold and injection cavity mold being pressed by the injection device, and it is also difficult to produce uneven thickness of the preform.

[0077] Figure 5 It is shown Figure 4 A diagram showing the side structure of the hot runner mold 42(52). Figure 5 In the structure, a side-view L-shaped bracket 66 is installed on the hot runner fixing plate 64. The second interface portion 65 is held by the connecting portion (connecting plate) 66a of the bracket 66 and the relay portion 63. The first interface portion 61 is connected to the second interface portion 65 in a state where it is loosely fitted into the connecting portion 66b of the bracket 66 by the connecting pin 67.

[0078] Figure 6 , Figure 7 It is shown Figure 4 A diagram of the structure of a further modified example. In Figure 6 , Figure 7 In the structure, a pressure-bearing block 70, which bears the load of the relay section 63 generated by contact with the nozzle of the injection device 38 (39), is fixed to the hot runner fixing plate 64. In addition, a runner section (runner bushing section) 71 is connected to the relay section 63. A nozzle receiving section 71a is formed at the top end of the runner section 71, which abuts against the nozzle of the injection device 38 (39).

[0079] like Figure 6 As shown, the resin inlet 63a of the relay section 63 (relay block) and its mating surface with the gating section 71 are arranged obliquely relative to the resin inlet 62b of the hot runner body section 62 when viewed from above. Furthermore, a pressure-bearing block 70 is disposed on the side of the relay section 63 located opposite to the resin inlet 63a. A heat insulation plate 72 is disposed between the side of the relay section 63 and the pressure-bearing block 70.

[0080] like Figure 7 As shown, a locating pin 73 is inserted into the lower side of the pressure block 70, through which the hot runner fixing plate 64 is supported on the lower base (not shown). The pressure block 70 is positioned on the hot runner fixing plate 64 by the locating pin 73. Furthermore, the pressure block 70 is fixed to the hot runner fixing plate 64 by bolts (not shown) inserted from the top into bolt holes 74. The pressure block 70 forms a predetermined gap with respect to the hot runner body 62 and is fixed to the hot runner fixing plate 64 without contacting the hot runner body 62. The relay part 63 is, for example, a generally cylindrical component having a first cut and a second cut. The first cut is formed by obliquely cutting the side surface of the cylindrical component from the end face (circular surface) of the side that does not abut against the hot runner body 62. The second cut is formed by cutting the side surface of the cylindrical component. A sprue section 69 (second interface section 65) is connected to the first cut section, and a pressure block 70 is connected to the second cut section via a heat insulation plate 72.

[0081] The intermediate section 63 has a resin inlet 63a at the mating surface with the gating section 71. The intermediate section 63, as... Figure 6 As shown by the middle arrow, the mating surface with the gating section 71 is used to withstand the forces generated in the gating section 71 due to the injection of molten resin, the holding of the nozzle of the injection device, etc. The mating surface of the relay section 63 with the gating section 71 is inclined relative to the resin inlet 62b of the hot runner body 62, so the forces generated in the gating section 71 and the relay section 63 are a combination of the first component force acting in the depth direction (Y direction in the figure) of the hot runner body 62 and the second component force acting in the width direction (X direction in the figure) of the hot runner body 62.

[0082] Through the second component force described above, the relay section 63 presses the heat insulation plate 72 and the pressure block 70 in the X direction of the figure. Correspondingly, the relay section 63, which supports (or abuts) the pressure block 70, experiences a reaction force from the pressure block 70 fixed to the hot runner fixing plate 64. Therefore, in Figure 6 , Figure 7 In this structure, the pressure block 70 bears the second component of the force generated by the nozzle in the X direction in the figure, suppressing the positional displacement of the relay part 63 and the gating part 71, and properly maintaining their connection state. That is, the pressure block 70 functions as a limiting part to prevent improper movement of the relay part 63 or the nozzle bearing part 71a.

[0083] In addition, according to Figure 6 , Figure 7 The structure also eliminates the need for excessive nozzle contact force to suppress resin leakage. Therefore, it can suppress tilting and positional displacement relative to the lower base caused by the hot runner mold and injection cavity mold being pressed by the injection device, and it is also difficult to produce uneven thickness of the preform.

[0084] Moreover, in Figure 6 , Figure 7 In the structure, with Figure 4 Compared to the previous structure, this design reduces the number of connecting parts around the nozzle without requiring increased machining precision for each part, thus reducing manufacturing costs.

[0085] Here, in the manufacturing of the release container, the first layer 11 of the preform 10 is formed in the first injection molding section 31 (first injection molding step). Then, by moving the rotating plate 37a, the first layer 11 of the preform 10 is temperature-adjusted in the first temperature adjustment section 32 (first temperature adjustment step) and then sequentially conveyed to the second injection molding section 33. Alternatively, the first temperature adjustment step in the first temperature adjustment section 32 can be omitted. In the second injection molding section 33, a second layer 12 is stacked on the inner circumferential side of the first layer 11 of the preform 10 (second injection molding step). Then, the preform 10 is temperature-adjusted in the second temperature adjustment section 34 (second temperature adjustment step) and shaped into a release container by stretch blow molding in the blow molding section 35 (blow molding step). Finally, the shaped release container is removed in the removal section 36 (removal step). Then, by rotating the rotating plate 37a of the conveying mechanism 37 by a predetermined angle, the above-mentioned processes are repeated. In addition, during the operation of the blow molding apparatus 30, the manufacturing of six sets of peeling containers with a time difference of one process is performed in parallel.

[0086] 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.

[0087] In the above embodiments, an example of a mold for the injection molding section of a peelable container manufacturing apparatus was described. However, the present invention is not limited to the injection molding section of a peelable container manufacturing apparatus, and can be widely applied to cases where the nozzle of the injection apparatus is arranged at an angle from a position orthogonal to the resin inlet of the hot runner mold.

[0088] In the above embodiments, a blow molding apparatus 30 for molding a double-layer preform for manufacturing a release container has been described. However, the structure of the blow molding apparatus of the present invention is not limited to the manufacture of release containers and can be widely applied to blow molding apparatuses having two injection molding sections. For example, the structure of the blow molding apparatus of the present invention can also be applied to the manufacture of decorative containers obtained by shaping multi-layer preforms of different colors, and the manufacture of resin containers with a double-layer structure using recycled plastic for the outer layer.

[0089] Furthermore, the embodiments disclosed herein should be considered illustrative rather than restrictive in all respects. The scope of the invention is set forth in the claims rather than in the foregoing description, and is intended to include all modifications of the same meaning and scope as the claims.

[0090] Explanation of reference numerals in the attached figures

[0091] 10…Pre-plastic preform, 11…First layer, 11a…Recess, 12…Second layer, 16…Opening, 17…Recess, 18…Film part, 30…Blow molding device, 31…First injection molding part, 33…Second injection molding part, 35…Blow molding part, 38…First injection device, 39…Second injection device, 40B, 50B…Cavity mold, 44…First protrusion, 54…Second protrusion.

Claims

1. A hot runner mold comprising: a hot runner mold main body portion fixed to a fixed plate and supplying molten resin received from a resin inlet to an injection mold; a nozzle receiving portion obliquely arranged from a position orthogonal to the resin inlet of the hot runner mold main body portion and coaxially connected to a nozzle of an injection device that supplies the molten resin; a relay portion having a first portion facing the nozzle receiving portion and a second portion on the opposite side of the first portion on the outside and having a resin flow path having a bent portion on the inside and guiding the molten resin from the nozzle receiving portion to the resin inlet; and a restriction portion fixed to the fixed plate and restricting movement of the nozzle receiving portion or the relay portion with respect to the hot runner mold main body portion, the restriction portion supporting the second portion of the relay portion at a position spaced apart from the hot runner mold main body portion in the extension direction of the resin inlet without contacting the hot runner mold main body portion and receiving a part of a force received by the relay portion from the nozzle.

2. The hot runner mold according to claim 1, wherein the nozzle receiving portion has a first member abutting against the nozzle and a second member connected to the first member and inserted into the relay portion, the first member is loosely fitted with respect to the restriction portion and allows tilting of the first member with respect to the second member in the axial direction caused by thermal expansion of the hot runner mold main body portion.

3. A resin container manufacturing apparatus comprising: an injection molding portion having the hot runner mold according to claim 1 or 2 and performing injection molding on a bottomed tubular preform; and a blow molding portion performing blow molding on the preform obtained by the injection molding portion in a state of retaining heat at the time of injection molding and manufacturing a resin container.

4. The resin container manufacturing apparatus according to claim 3, wherein the manufacturing apparatus has a plurality of the injection molding portions, and the blow molding portion performs blow molding on a multilayer preform obtained by stacking a plurality of injection molding. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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