Resinous container and method for manufacturing resinous container

Abstract

This resinous container is provided with: a neck part that forms an entrance and exit part for a liquid; a barrel part that is connected to the neck part; and a bottom part that is connected to the barrel part and formed to close an opening of the resinous container. The barrel part has an opposed surface that faces another resinous container when joined thereto or separated therefrom. The opposed surface has a joining part that is capable of joining to or separating from another resinous container. The joining part has a recessed part recessed toward the center of the resinous container from the opposed surface and a protruding part protruding from the opposed surface in the direction opposite to the direction in which the recessed part is recessed. This resinous container has been configured so that when a plurality of the resinous containers are jointed together by inserting the protruding part of one resinous container into the recessed part of another resinous container, then said one resinous container can take either a loosely fitted position in which the protruding part has fitted into the recessed part so as to leave a space therebetween or a fitted position in which the protruding part has fitted into the recessed part. The loosely-fitted position is shifted to the fitted position by rotationally moving said one resinous container relatively to said another resinous container on, as an axis, the direction of insertion of the protruding part into the recessed part.

Description

Resin container and method for manufacturing resin container

[0001] The present disclosure relates to a resin container and a method for manufacturing a resin container.

[0002] Patent Document 1 discloses a resin container having a connecting portion, in which two or more containers of the same shape are configured to be connectable or separable through the connecting portions facing each other.

[0003] Japan Special Publication No. 2022-542654 Japanese Special Publication No. 4-36937

[0004] The coupling portion of Patent Document 1 is configured such that a groove formed along the vertical direction of one container engages with a protrusion formed along the vertical direction of the other container. This coupling portion acts to resist separation of the containers when a force attempting to separate the containers is applied in a direction other than the vertical direction. However, when a force attempting to separate the containers is applied in the vertical direction, the coupling portion is less likely to resist separation of the containers.

[0005] In addition, Patent Document 2 also considers forming recesses and protrusions on two resin containers, and then fitting the protrusions and recesses of the resin containers together to join them. However, since the joining and separating operations of the containers are performed repeatedly, it is desirable that the resin containers do not deform when they are fitted together. If the resin containers are deformed, the joining and separating of the resin containers may not be performed reproducibly.

[0006] An object of the present disclosure is to provide a resin container that is resistant to undoing and has good reproducibility in bonding and separation, and a method for manufacturing such a resin container.

[0007] A resin container according to one aspect of the present disclosure is a resin container comprising: a neck portion forming an inlet / outlet portion for a liquid; a body portion connected to the neck portion; and a bottom portion connected to the body portion and configured to close an opening of the resin container, wherein the body portion has opposing surfaces that face each other when the resin container is joined to or separated from another resin container, and the opposing surfaces are provided with joining portions that allow the resin container to be joined to or separated from the other resin container, and the joining portions include a recess that is recessed from the opposing surface toward the center of the resin container, and a protrusion that protrudes from the opposing surface in a direction opposite to the recessed direction of the recess, and when a plurality of the resin containers are joined together, the resin containers are configured to be able to take a loose-fitting position in which the protrusion of one resin container is inserted into the recess of the other resin container, so that the protrusion fits into the recess with a gap therebetween, and a fitted position in which the protrusion is fitted into the recess, One of the resin containers is rotated relative to the other of the resin containers about an axis that is the insertion direction of the convex portion into the concave portion, thereby shifting from the loose-fitting position to the fitted position.

[0008] According to the present disclosure, it is possible to provide a resin container that is difficult to come loose and has good reproducibility in bonding and separation, and a method for manufacturing a resin container.

[0009] FIG. 1 is a perspective view and a partially enlarged view of a resin container according to a first embodiment. FIG. 2 is a side view and a partially enlarged view of a resin container according to the first embodiment. FIG. 3A is a view illustrating how resin containers according to the first embodiment are joined together. FIG. 3B is a view illustrating how resin containers according to the first embodiment are joined together. FIG. 3C is a view illustrating how resin containers according to the first embodiment are joined together. FIG. 4 is a perspective view of a resin container according to a second embodiment. FIG. 5 is a side view of a joining portion according to the second embodiment. FIG. 6 is a front view of a joining portion according to the second embodiment. FIG. 7 is a view illustrating how resin containers according to the second embodiment are joined together. FIG. 8 is a view illustrating how resin containers according to the second embodiment are joined together. FIG. 9 is a functional block diagram of an apparatus for manufacturing a resin container according to the first or second embodiment.

[0010] Hereinafter, a resin container will be described as an embodiment of the present disclosure with reference to the drawings. For the sake of convenience, the dimensions of each component shown in the drawings may differ from the actual dimensions of each component.

[0011] Also, for ease of explanation, the terms "up-down direction," "left-right direction," and "front-rear direction" will be referred to as appropriate. Here, the "up-down direction" is a direction that includes the "upward direction" and the "downward direction." The "left-right direction" is a direction that includes the "leftward direction" and the "rightward direction." The "front-rear direction" is a direction that includes the "forward direction" and the "rearward direction." In the figures described below, the symbol U indicates the upward direction. The symbol D indicates the downward direction. The symbol L indicates the leftward direction. The symbol R indicates the rightward direction. The symbol F indicates the forward direction. The symbol B indicates the rearward direction. Unless otherwise specified, the direction in which the opening of the resin container is provided will be described as the upward direction.

[0012] (First embodiment) Fig. 1 is a perspective view and a partially enlarged view of a resin container 100 according to the first embodiment. Fig. 2 is a side view and a partially enlarged view of the resin container 100. The resin container 100 comprises a neck 110, a body 120, and a bottom 130. The neck 110 forms an inlet / outlet for liquid. The body 120 is connected to the neck 110. The bottom 130 is connected to the body 120. The bottom 130 is configured to close the opening of the resin container 100. A shoulder is provided between the neck 110 and the body 120, which expands in diameter from the lower end of the neck 110 and is connected at an angle to the body 120.

[0013] The body 120 has an opposing surface 121 (mating surface 121) that faces when connecting or disconnecting from another resin container 100. The opposing surface 121 is provided with a connecting portion 122 that can connect or disconnect from another resin container 100. The connecting portion 122 includes a recess 123 and a protrusion 124. The recess 123 is recessed from the opposing surface 121 toward the center of the resin container 100. Here, "toward the center of the resin container 100" does not strictly mean toward the central axis of the resin container 100. "Toward the center of the resin container 100" means generally a direction approaching the central axis of the resin container 100. The protrusion 124 protrudes from the opposing surface 121 in the direction opposite to the recessed direction of the recess 123. The recess 123 and the protrusion 124 are adjacent to each other. At this adjacent portion, the side of the protrusion 124 and the side of the recess 123 are configured to be flush with each other. The side surfaces of the convex portion 124 and the concave portion 123 in the adjacent areas are linear and parallel to the central axis of the resin container 100 .

[0014] As illustrated in FIGS. 1 and 2 , the recess 123 includes a common defining portion 123a, a first defining portion 123b, and a second defining portion 123c. The common defining portion 123a is disposed on the bottom 130 side, while the first defining portion 123b and the second defining portion 123c are disposed on the neck 110 side. The first defining portion 123b has a semicircular shape, and the second defining portion 123c has a shape in which two semicircular shapes overlap. The second defining portion 123c is provided closer to the convex portion 124 than the first defining portion 123b. The recess formed by the common defining portion 123a and the first defining portion 123b is referred to as the first recess 123A. The recess formed by the common defining portion 123a and the second defining portion 123c is referred to as the second recess 123B. In this case, it is desirable that the second recess 123B be formed to have a smaller area than the first recess 123A.

[0015] The recess 123 is provided with a rotation suppressing portion 125 that suppresses the relative rotation of the resin containers 100 with respect to the protrusion 124' (see FIG. 3A) of another resin container 100' (see FIG. 3A) about the axis of the front-rear direction, which is the insertion direction. In this embodiment, the rotation suppressing portion 125 is formed so as to separate the first defining portion 123b and the second defining portion 123c. The rotation suppressing portion 125 is formed so as to protrude toward the center of the recess 123.

[0016] As illustrated in Fig. 2, the convex portion 124 is provided with a groove portion 124a recessed in a direction intersecting the rearward direction, which is the insertion direction, at a portion close to or connected to the opposing surface 121. The groove portion 124a is recessed in a direction intersecting the rearward direction, which is the insertion direction, (downward or toward the bottom portion 130). The second recess portion 123B (more specifically, the second defining portion 123c) is provided with a protruding portion 123Ba protruding in a direction intersecting the rearward direction, which is the insertion direction, (downward or toward the bottom portion 130). The recessed depth of the groove portion 124a and the protruding height of the protruding portion 123Ba do not need to be uniform. When the resin containers 100 are joined together and in a mated position, which will be described later, the groove portion 124a and the protruding portion 123Ba are configured to engage with each other. Such groove portion 124a and protrusion portion 123Ba can be formed by using movable mold parts in the corresponding positions of groove portion 124a and protrusion portion 123Ba in a blow molding mold (a blow cavity mold consisting of a pair of split molds and a bottom mold that abuts against the blow cavity mold).

[0017] Next, the joining of the resin containers 100, 100' to each other will be described. Figures 3A to 3C illustrate an example of how the resin containers 100, 100' are joined together. The resin container 100 is configured to be joined to another resin container 100' via a joining portion 122. As shown in Figure 3A, the convex portion 124 of one resin container 100 is inserted backward into the concave portion 123' of the other resin container 100'. The backward direction is an example of the insertion direction. As shown in Figure 3B, when the convex portion 124 is inserted into the concave portion 123', the convex portion 124 fits into the concave portion 123' with a gap between them. In this state, the resin container 100 is in a loose-fitting position. Furthermore, by rotating the resin containers 100, 100' relative to each other around an axis in the forward / backward direction, which is the insertion direction, the resin containers are shifted from the loose-fitting position to a fitted position as illustrated in Figure 3C. In the mating position, the convex portion 124 is mated with the concave portion 123' and is held so as not to fall out of the concave portion 123'. In the mating position, the protrusion 123Ba' of one resin container 100 is engaged with the groove portion 124a of the other resin container 100.

[0018] 3B, when the resin containers 100, 100' are in a loosely fitted position, the central axes X, X' of the two resin containers 100, 100' are twisted relative to each other. In a fitted position in which the resin containers 100, 100' are rotated relatively around an axis in the front-to-rear direction, which is the insertion direction, it is desirable that the central axes X, X' of the two resin containers 100, 100' be parallel to each other.

[0019] As illustrated in Figures 3B and 3C, the common defining portion 123a' contacts the convex portion 124 of the resin container 100 in the loose-fitting position and the fitted position. The first defining portion 123b' is configured to be able to contact the convex portion 124 of another resin container 100' in the loose-fitting position. The second defining portion 123c' is configured to be able to contact the convex portion 124' of another resin container 100' in the fitted position. In the loose-fitting position, the convex portion 124 is accommodated in the first recess 123A' with a gap therebetween. The second recess 123B' is formed to have a smaller area than the first recess 123A', and in the fitted position, the convex portion 124 is accommodated in a fitted state in the second recess 123B'.

[0020] When the resin containers 100, 100' are rotated relative to each other and transition from the loose-fitting position to the fitted position, the rotation suppression portion 125' suppresses the movement of the convex portion 124 from the first recess 123A' to the second recess 123B'. When the resin containers 100, 100' are rotated relative to each other and transition from the fitted position to the loose-fitting position, the rotation suppression portion 125' suppresses the movement of the convex portion 124 from the second recess 123B' to the first recess 123A'. When the resin containers 100, 100' are rotated relative to each other with less than a predetermined force, the rotation suppression portion 125' suppresses the movement of the convex portion 124 between the first recess 123A' and the second recess 123B'.

[0021] As described above, when the protrusion 124 is fitted into the second recess 123B' in the fitted position, the groove 124a and the protrusion 123Ba' are configured to engage with each other. This prevents the protrusion 124 from being displaced forward, which is the opposite direction to the insertion direction. This prevents the resin containers 100, 100' from separating from each other.

[0022] Conventional connectable resin containers are configured to be connected by pressing two resin containers together in a direction that brings them closer together and fitting their respective recesses and projections together. In other words, the forces that connect the two resin containers and the forces that separate them are formed in opposite directions on a straight line. However, moving the resin containers in the direction opposite to the connecting direction can easily cause the containers to become disconnected, and conventional configurations are insufficient for providing resin containers that are difficult to disconnect. Furthermore, when such resin containers are repeatedly connected and separated, the recesses and projections of the containers can deform during the connecting process, making it difficult to reproducibly connect and separate them.

[0023] The resin container 100 configured as described above can assume a loose-fitting position and a fitted position when the resin containers 100, 100' are coupled together. The resin containers 100 can transition from the loose-fitting position to the fitted position by rotating the resin containers 100 relative to each other around the axis of the insertion direction. In other words, coupling and separation of the resin containers 100, 100' requires rotation in a direction different from the direction in which the resin containers 100, 100' approach and separate from each other. Because the insertion direction and the rotation direction are different, separation of the resin containers 100 is difficult without rotating the resin containers 100 from the fitted position to the loose-fitting position. This provides a resin container 100 that is difficult to uncouple. Furthermore, compared to the operation of applying force in the opposite direction to the insertion direction to separate the resin containers 100, rotation makes the coupling portion 122 more likely to slide (move) in the rotation direction and is less likely to deform, thereby providing a resin container 100 with good coupling and separation reproducibility.

[0024] Generally, connectable resin containers are often transported in a connected state. In the resin container 100 configured as described above, the central axes X, X' of the resin containers 100, 100' are twisted relative to each other in the loose-fitting position, but the central axes X, X' of the two resin containers 100, 100' are aligned parallel to each other in the fitted position. This provides a resin container 100 that is easy to transport in a connected position.

[0025] The resin container 100 configured as described above is provided with a rotation suppression portion 125, which suppresses the resin containers 100, 100' from rotating relative to each other. Even if the resin containers 100, 100' are rotated relative to each other with less than a predetermined force, they are unlikely to transition from the fitted position to the loose-fit position, making it less likely that the resin containers 100, 100' will unintentionally become uncoupled.

[0026] In the resin container 100 configured as described above, the second recess 123B is formed to have a smaller area than the first recess 123A. This makes it easy to insert the protrusion 124' of another resin container 100' into the first recess 123A in the loose-fitting position, while easily realizing a resin container 100 that is difficult to come loose in the fitted position.

[0027] The resin container 100 having the above-described configuration is configured so that the groove 124a of the convex portion 124 and the protrusion 123Ba' of the concave portion 123' are engaged in the fitted position, thereby making it difficult for the resin containers 100, 100' to come loose from each other.

[0028] Second Embodiment Next, a resin container 200 according to a second embodiment will be described. Fig. 4 is a perspective view of the resin container 200 according to the second embodiment. The resin container 200 also includes a connecting portion 222 formed of a protrusion 224 and a recess 223, but the shape of the connecting portion 222 is different from the connecting portion 122 of the resin container 100 according to the first embodiment.

[0029] FIG. 5 is a side view of the joint portion 222 of the resin container 200. FIG. 6 is a front view of the joint portion 222 of the resin container 200. As illustrated in FIGS. 4 to 6, the recessed portion 223 and the protruding portion 224 are adjacent to each other on the opposing surfaces of the body of the resin container 200. The recessed portion 223 and the protruding portion 224 are semicircular in shape with the adjacent side linear in a front view (viewed from the opposing surface). The recessed portion 223 has a recessed side surface 223a on the side adjacent to the protruding portion 224. The recessed side surface 223a is flush with the protruding portion side surface 224a of the protruding portion 224 and has a main surface portion 223a1 that determines the loose fit posture and a recessed portion 223a2 that determines the fitting posture. In a front view, the main surface portion 223a1 is located on the bottom side, and the recessed portion 223a2 is located on the neck side, relative to the center (center) of the protruding portion side surface 224a (straight line). The recessed portion 223a2 is configured so as not to be visible from the front view due to the protruding portion 224. In other words, the recessed portion 223a2 is inclined from the upper end of the main surface portion 223a1 toward the protruding portion 224 and is located behind the protruding portion 224. Such a recessed portion 223a2 can be formed by employing a movable mold part at a position corresponding to the recessed portion 223a2 in the blow molding mold. Furthermore, in the front view, the protruding portion side surface 224a (straight line) is configured to be inclined with respect to the central axis of the resin container 200 or the recessed portion 223a2 (straight line).

[0030] As shown in FIG. 4 , a first flange 211 and a second flange 212 are provided on the neck portion 210 of the resin container 200. The first flange 211 and the second flange 212 are provided at different heights. In this embodiment, the second flange 212 is provided below the first flange 211. A through hole 211a is formed in the first flange 211. A protrusion 212a is formed in the second flange 212. In this embodiment, the protrusion 212a protrudes upward from the second flange. The protrusion 212a is configured to be insertable into the through hole 211a. The shapes of the first flange 211 and the second flange 212 are determined by an injection molding die (a neck die consisting of a pair of split dies and an injection cavity die abutting against the neck die) when a preform is produced in an injection molding process.

[0031] 7 and 8 show an example of how resin containers 200 are joined together. The resin container 200 of this embodiment is also configured to be able to assume a loose-fitting position and a fitted position. That is, in the loose-fitting position, the convex portion 224 of the resin container 200 fits into the concave portion 223' of another resin container 200' with a gap therebetween, and in the fitted position, the resin container 200 is fitted into the other resin container 200'. The transition from the loose-fitting position to the fitted position is achieved by rotating the resin containers 200, 200' relatively around an axis in the insertion direction.

[0032] In the mating position, the recessed portion 223a2' of one resin container 200' is configured to engage with the protruding portion 224 of the other resin container 200. This prevents the resin containers 200, 200' from moving apart in the direction opposite to the insertion direction.

[0033] Furthermore, in the first flange 211′ and the second flange 212 provided on the neck portion 210, the protrusion 212a is not received in the through hole 211a′ in the loose-fitting position. However, in the fitted position, the protrusion 212a is inserted into and received in the through hole 211a′.

[0034] In this way, the resin container 200 in the second embodiment can also take a loose-fitting position and a fitted position, and can be shifted from the loose-fitting position to the fitted position by rotating the resin containers 200, 200' relatively around the axis of the insertion direction. This makes it possible to realize a resin container 200 that is difficult to come loose and can be connected and separated with high reproducibility.

[0035] Furthermore, a first flange 211 and a second flange 212 are formed on the neck 210 of the resin container 200 of the second embodiment. In the fitted position, a protrusion 212a formed on the second flange 212 is configured to be insertable into a through-hole 211a' formed in the first flange 211' of another resin container 200'. This prevents the resin containers 200, 200' from separating away from each other or from shifting from the fitted position to the loose-fit position at an unintended timing.

[0036] Furthermore, the resin containers 200, 200' are configured so that the recessed portion 223a2 and the protruding portion 224' engage with each other when the containers are in the mated position. This prevents the resin containers 200, 200' from separating from each other in the direction opposite to the insertion direction. Furthermore, because a structure for engaging the contact surfaces of the protruding portion 224' and the recessed portion 223 is provided, the recessed portion 223a2, which is the engaging structure, is small, which facilitates simplifying the configuration of the mold for blow molding.

[0037] (Description of Manufacturing Apparatus and Manufacturing Method) A manufacturing apparatus 10 and a manufacturing method for manufacturing the resin containers 100 and 200 will be described with reference to Fig. 9. Fig. 9 is a functional block diagram of the manufacturing apparatus 10.

[0038] As shown in Fig. 9, the manufacturing apparatus 10 includes an injection molding section 11 for manufacturing bottomed preforms and a temperature control section 12 for adjusting the temperature of the manufactured preforms. An injection device 15 for supplying raw resin material is connected to the injection molding section 11. The manufacturing apparatus 10 also includes a blow molding section 13 for blowing the preforms to manufacture containers, and an ejection section 14 for ejecting the manufactured containers. The manufacturing apparatus 10 is a hot parison type (one-step) blow molding apparatus that manufactures resin containers 100, 200 by utilizing the heat (calorific value) remaining in the preforms after injection molding.

[0039] The injection molding section 11, the temperature control section 12, the blow molding section 13, and the removal section 14 are located at positions rotated by a predetermined angle (90 degrees in this embodiment) around the conveying means 16. The conveying means 16 is composed of a rotating plate or the like. Neck molds are attached to the underside of the rotating plate at positions corresponding to each section. Preforms or resin containers 100, 200 whose necks are supported by the neck molds are configured to be conveyed to each section as the rotating plate rotates.

[0040] The injection molding unit 11 illustrated in FIG. 9 is responsible for the preform injection molding process and includes an injection cavity mold, an injection core mold, a neck mold consisting of a pair of split molds, and the like (not shown). The injection cavity mold determines the outer surface shape of the body and bottom of the preform. The injection core mold determines the inner surface shape of the neck (neck 110, 210 of the resin container 100, 200) and body and bottom of the preform. The neck mold determines the outer surface shape of the neck (neck 110, 210 of the resin container 100, 200). A bottomed preform is manufactured by pouring molten resin material (e.g., thermoplastic resin such as polyethylene terephthalate (PET)) from an injection device 15 into a preform-shaped molding space (cavity) formed by clamping these molds. The preform has an optimum wall thickness distribution (shape) depending on the container, and the thickness (average thickness, wall thickness) of the body is set to, for example, 1.0 to 8.0 mm, preferably 2.0 to 4.0 mm. The manufactured preform is transported to the temperature control unit 12 in a state where it has retained heat.

[0041] When manufacturing the resin container 200 of the second embodiment, a molding space for forming the first flange 211 and the second flange 212 is provided on at least one or both of the lower surface of the neck mold and the upper surface of the injection cavity mold. This allows the first flange 211 and the second flange 212 to be formed in the injection molded portion 11 with high dimensional accuracy and good fitting performance.

[0042] The temperature control unit 12 is responsible for a temperature control step of adjusting the temperature of the injection-molded preform to a temperature suitable for blow molding, and is equipped with a temperature control mold (not shown). The temperature control unit eliminates or reduces temperature deviations in the preform caused by injection molding, and provides the preform with a temperature distribution suitable for the resin containers 100, 200. The temperature-controlled preform is transported to the blow molding unit 13.

[0043] The blow molding unit 13 is responsible for the blow molding process of shaping the temperature-controlled preform into the resin container 100, 200, and includes a stretch rod, a blow core mold, a blow cavity mold consisting of a pair of split molds, a bottom mold, etc. (not shown). The blow cavity mold includes a molding space that defines the outer surface shapes of the shoulder and body of the resin container 100, 200, and a molding space that defines the outer diameter shape of the joint portion 122, 222. The bottom mold defines the outer surface shape of the bottom of the resin container 100, 200.

[0044] When manufacturing the resin container 100 of the first embodiment, the blow cavity mold is provided with movable mold parts that form the groove 124a of the convex portion 124 and the protrusion 123Ba of the second recess 123B (second defining portion 123c). When manufacturing the resin container 200 of the second embodiment, the blow cavity mold is provided with movable mold parts that form the recess 223a2.

[0045] The following steps are performed in the blow molding section 13. After a preform is loaded into the open blow cavity mold, the blow cavity mold is closed and the preform is placed inside the blow cavity mold. At approximately the same time, the bottom mold rises from its standby position to its molding position, the blow core mold descends from its standby position to abut against the neck of the preform, and the stretch rod descends from its standby position to insert into the preform. Note that at this time (before the preform expands), the movable mold parts remain in their standby (retracted) positions without being driven. Next, the stretch rod descends to stretch the preform vertically, and air is introduced into the preform from the blow core mold to stretch (expand) the preform horizontally. Once the preform reaches the cavity surface of the joint, the movable mold parts are driven to move (advance) to the shaping position, forming the groove 124a and the protrusion 123Ba or the depression 223a2. After these portions are formed, the movable mold parts are returned to their standby positions. When the production of the resin container 100, 200 is completed, the blow cavity mold is opened to release the resin container 100, 200, and the bottom mold, blow core mold, and stretch rod are returned to their standby positions. The blow-molded resin container 100, 200 is transported to the removal section 14.

[0046] The removal unit 14 is responsible for the removal process of removing the resin containers 100, 200 from the manufacturing apparatus 10. The removal unit 14 opens the neck molds and releases the neck portions 110, 210 from the neck molds, thereby removing the resin containers 100, 200 from the manufacturing apparatus 10, dropping them, and discharging (removing) them outside the apparatus.

[0047] Although the embodiments of the present disclosure have been described above, it goes without saying that the technical scope of the present disclosure should not be interpreted as being limited by the description of the present embodiments. The present embodiments are merely examples, and it will be understood by those skilled in the art that various modifications of the embodiments are possible within the scope of the invention described in the claims. The technical scope of the present disclosure should be determined based on the scope of the invention described in the claims and its equivalents.

[0048] For example, in the second embodiment, a resin container having a first flange with a through hole and a second flange with a protrusion is exemplified, but the resin container in the first embodiment may be configured to have the above-mentioned first flange and second flange.

[0049] The resin containers of the first and second embodiments may be manufactured using a hot parison blow molding apparatus (one-step injection stretch blow molding method) such as that disclosed in FIG. 1 of Japanese Patent No. 6505344. The blow molding apparatus preferably includes at least an injection device, an injection molding section equipped with an injection mold, and a blow molding section equipped with a blow mold. A temperature control section for adjusting the temperature distribution of the preform between the injection molding section and the blow molding section, and a removal section between the blow molding section and the injection molding section may also be provided.

[0050] This application is based on a Japanese patent application (Patent Application No. 2022-197985) filed on December 12, 2022, the contents of which are incorporated herein by reference.

[0051] 100, 200 Resin container 110, 210 Neck portion 120 Body portion 121 Opposing surface (fitting surface) 122, 222 Joining portion 123, 223 Recess 123a Common defining portion 123A First recess 123b First defining portion 123B Second recess 123Ba Projecting portion 123c Second defining portion 124, 224 Convex portion 124a Groove portion 125 Rotation suppressing portion 130 Bottom portion 211 First flange 211a Through hole 212 Second flange 212a Protrusion 223a Convex portion side surface 223a1 Main surface portion 223a2 Depression portion 224a Convex portion side surface

Claims

1. a neck portion forming an inlet / outlet portion for a liquid; a body portion connected to the neck portion; A resin container comprising: a bottom portion connected to the body portion and configured to close an opening of the resin container; the body portion has opposing surfaces that face each other when the body portion is connected to or separated from another resin container, a connecting portion that can be connected to or separated from another resin container is provided on the opposing surface, The joining portion includes a recessed portion recessed from the opposing surface toward the center of the resin container, and a protruding portion protruding from the opposing surface in a direction opposite to the recessed direction of the recessed portion, When a plurality of the resin containers are joined together, the resin containers are a loose fitting posture in which the convex portion of one of the resin containers is inserted into the concave portion of the other of the resin containers, so that the convex portion fits into the concave portion with a gap therebetween; a fitting posture in which the protrusion is fitted into the recess; It is configured to be able to take One of the resin containers is rotated relative to the other of the resin containers about an axis in a direction in which the protrusion is inserted into the recess, thereby transitioning from the loose-fitting posture to the fitted posture. Resin container.

2. In the loose fitting position, the central axes of the two resin containers are twisted relative to each other, In the fitted position, the central axes of the two resin containers are parallel to each other. The resin container according to claim 1.

3. The recessed portion includes a rotation suppressing portion that suppresses the resin containers from rotating relative to the protruding portion of another resin container around the insertion direction as an axis. The resin container according to claim 1.

4. The neck portion includes a first flange and a second flange formed to extend toward the coupling portion, The first flange and the second flange are provided at different heights, a through hole formed in the first flange; The second flange is formed with a protrusion, In the fitted position, the protrusion formed on one of the resin containers is configured to be insertable into the through hole formed on the other of the resin containers. The resin container according to claim 1.

5. The recessed portion includes a common defining portion that comes into contact with the convex portion of the other resin container in the loose-fitting position and the fitted position, a first defining portion that can come into contact with the convex portion of the other resin container in the loose-fitting position, and a second defining portion that is provided closer to the convex portion than the first defining portion and can come into contact with the convex portion of the other resin container in the fitted position, When the recess formed by the common defining portion and the first defining portion is defined as a first recess, and the recess formed by the common defining portion and the second defining portion is defined as a second recess, the second recess has an area smaller than that of the first recess. The resin container according to any one of claims 1 to 4.

6. The protrusion is provided with a groove recessed in a direction intersecting the insertion direction, The second recess is provided with a protruding portion that protrudes in a direction intersecting the insertion direction, When the resin containers are joined together and in the fitted position, the groove and the protrusion engage with each other to prevent the resin containers from separating from each other. The resin container according to claim 5.

7. the recess has a recess side surface adjacent to the protrusion, the recess side surface includes a main surface portion that is flush with the protrusion side surface of the protrusion and determines the loose-fitting posture, and a recess portion that determines the fitting posture, In the fitted position, the recessed portion of one of the resin containers is engaged with the protruding portion of the other of the resin containers to prevent the resin containers from separating from each other in a direction opposite to the insertion direction. The resin container according to any one of claims 1 to 4.

8. A method for manufacturing the resin container according to claim 1, an injection molding unit connected to the injection device for injection molding a resin preform with a bottom; a blow molding section for blow-molding the preform.