Closure plug structure and container with the same

Abstract

To provide a closure plug structure which enables easy opening operation of a cap, and to provide a container with the closure plug structure.SOLUTION: A closure plug structure 100 includes: a cap 1; and a spout 20 having a mouth portion 21 to which the cap 1 is attached. The cap 1 includes: a top plate portion 2; and a tube portion 3 extending downward from the peripheral edge of the top plate portion 2. The tube portion 3 is divided into a main portion 8 and a tamper evidence ring portion 9 connected to the main portion 8 by a bridge 7. The inner-circumferential surface of the main portion 8 is provided with a threaded portion 10. The outer-circumferential surface of the main portion 8 is provided with: an upper knurl 40 formed at a position including the upper end of the outer-circumferential surface; and a side knurl 50 formed at a position lower than the upper knurl 40.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a closure structure and a container with a closure structure. [Background technology]

[0002] A closure structure is used that includes a cap and a spout. The cap is attached to the spout. The closure structure is attached to the container. A knurled portion is formed on the outer peripheral surface of the cap (see, for example, Patent Document 1). The knurled portion has a function of preventing a user from slipping when gripping and rotating the cap. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-217966 A Summary of the Invention [Problem to be solved by the invention]

[0004] Depending on the container to which it is attached, the closure structure may need to have a reduced height (i.e., a low profile). Because the cap of this closure structure is low profile, the area of ​​the outer circumferential surface that can be gripped by the user is small. This can make it difficult to grip and rotate the cap.

[0005] One aspect of the present invention aims to provide a closure structure and a container with a closure structure that facilitates the operation of opening a cap. [Means for solving the problem]

[0006] One aspect of the present invention provides a closure structure comprising a cap and a spout having a mouth portion to which the cap is attached, the cap having a top plate portion and a tubular portion depending from the periphery of the top plate portion, the tubular portion being partitioned into a main portion and a tamper evidence ring portion connected to the main portion by a bridge, a threaded portion being formed on the inner surface of the main portion, and an upper knurl being formed on the outer surface of the main portion at a position that includes the upper end of the outer surface, and a side knurl being formed at a position lower than the upper knurl.

[0007] The plugging structure preferably has a smooth annular lower region formed on the outer circumferential surface of the main portion at a position lower than the side knurls.

[0008] It is preferable that the closure structure has an annular recess formed along the circumferential direction of the main portion at a position on the outer peripheral surface of the main portion that includes the upper end, and the upper knurl has a plurality of upper knurl protrusions protruding from the inner surface of the annular recess.

[0009] The upper knurled protrusion is preferably formed in a plate shape perpendicular to the circumferential direction.

[0010] One aspect of the present invention provides a container with a closure structure comprising the closure structure and a container to which the closure structure is attached. Effect of the Invention

[0011] According to one aspect of the present invention, it is possible to provide a closure structure and a container with a closure structure that facilitates the operation of opening a cap. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is a perspective view of a cap of the closure structure of the embodiment. [Diagram 2] FIG. 2 is a partial cross-sectional view of the capping structure of the embodiment. [Diagram 3] FIG. 2 is a partial cross-sectional view of the capping structure of the embodiment. [Figure 4]FIG. 2 is a perspective view of a capping structure according to an embodiment. [Diagram 5] 1 is a cross-sectional view of a container having an embodiment of a closure structure attached thereto. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] [Closure structure] Fig. 1 is a perspective view of a cap 1 of a capping structure 100 of an embodiment. Fig. 2 is a partial cross-sectional view of the capping structure 100. Fig. 3 is a partial cross-sectional view of the capping structure 100. Fig. 4 is a perspective view of the capping structure 100.

[0014] In the following explanation, the vertical positional relationship of the closure structure 100 will be provisionally defined based on FIG. 2. The central axis C1 is the central axis of the cap 1 and the mouth portion 21. The vertical direction is the direction along the central axis C1. The vertical direction is also called the "height direction." The direction around the central axis C1 is called the "circumferential direction." The direction perpendicular to the central axis C1 is called the "radial direction." The positional relationship defined here does not limit the posture of the closure structure 100 during use.

[0015] As shown in FIG. 2, the capping structure 100 includes a cap 1 and a spout 20. The spout 20 includes a mouth portion 21 and a base portion 24. The base portion 24 extends radially outward from the lower end of the mouth portion 21. The base portion 24 is formed in an annular shape. The base portion 24 is in the form of a plate perpendicular to the central axis C1.

[0016] The mouth portion 21 includes a tubular portion 30 and a flange portion 29. The tubular portion 30 includes a first reduced diameter portion 25, a main tube portion 26, a second reduced diameter portion 27 (reduced diameter portion), and an upward extension portion 28. The tubular portion 30 is formed in a generally cylindrical shape. The tubular portion 30 is formed so as to protrude generally upward from the inner peripheral edge of the base portion 24.

[0017] The first reduced diameter section 25 is formed in a cylindrical shape that increases while decreasing in diameter from the inner peripheral edge of the base section 24. The main tube section 26 is formed in a cylindrical shape that extends upward from the upper end of the first reduced diameter section 25. The second reduced diameter section 27 is formed in a cylindrical shape that increases while decreasing in diameter from the upper end of the main tube section 26.

[0018] The upward extension portion 28 is formed in a cylindrical shape extending upward from the upper end of the second reduced diameter portion 27. The upward extension portion 28 is located at a higher position than the main tube portion 26. The outer diameter D1 of the upward extension portion 28 is preferably equal to or smaller than the inner diameter D2 of the main tube portion 26 (specifically, the inner diameter of the main tube portion 26 in the height range where the male thread 22 is formed). That is, the outer diameter D1 of the upward extension portion 28 is preferably equal to or smaller than the inner diameter D2 of the main tube portion 26. By making the outer diameter D1 of the upward extension portion 28 equal to or smaller than the inner diameter D2 of the main tube portion 26, the rigidity of the mouth portion 21 can be increased. The outer diameter D1 of the upward extension portion 28 is equal to the outer diameter of the upper end of the first reduced diameter portion 25 (the minimum outer diameter of the first reduced diameter portion 25).

[0019] The flange portion 29 extends radially outward from the upper end of the cylindrical portion 30 (more specifically, the upper end of the upward extension portion 28). The flange portion 29 is formed in an annular shape. The flange portion 29 is in the form of a plate perpendicular to the central axis C1. The upper surface of the flange portion 29 abuts against the inner surface (lower surface) of the top plate portion 2. The outer peripheral surface 29a of the flange portion 29 abuts against the inner peripheral surface 15a of the downward extension portion 15 (see FIG. 3). In this embodiment, the outer peripheral surface 29a of the flange portion 29 abuts against the downward extension portion 15, and the upper surface of the flange portion 29 abuts against the inner surface (lower surface) of the top plate portion 2, but the upper surface of the flange portion 29 does not have to abut against the inner surface of the top plate portion 2 as long as the outer peripheral surface abuts against the downward extension portion 15.

[0020] The outer diameter of the flange portion 29 (outer diameter when the cap 1 is not attached) is preferably larger than the inner diameter of the downward extension portion 15 of the cap 1 (inner diameter when the cap 1 is not attached to the mouth portion 21). As a result, when the flange portion 29 is fitted inside the downward extension portion 15, the flange portion 29 and the downward extension portion 15 come into contact with each other in a state where at least one of them is elastically deformed. The flange portion 29 is in a state of being elastically deformed in a contracted diameter. The downward extension portion 15 is in a state of being elastically deformed in a expanded diameter. Therefore, the flange portion 29 and the downward extension portion 15 come into contact with each other in a state where an elastic force acts in a direction in which they approach each other. One of the flange portion 29 and the downward extension portion 15 may be deformed, or both may be deformed. Therefore, the adhesion between the outer peripheral surface 29a of the flange portion 29 and the inner peripheral surface 15a of the downward extension portion 15 can be improved, and the sealing property of the closure structure 100 can be improved.

[0021] A male thread 22 is formed on the outer circumferential surface of the main cylindrical portion 26. The male thread 22 protrudes radially outward from the outer circumferential surface of the main cylindrical portion 26. The male thread 22 is screwed into the threaded portion 10 of the cap 1. A plurality of locking protrusions 23 are formed on the outer peripheral surface of the first reduced diameter portion 25. The locking protrusions 23 are block-shaped protrusions that protrude radially outward from the outer peripheral surface of the upper part of the first reduced diameter portion 25. The locking protrusions 23 are formed at a position lower than the male threads 22. The multiple locking protrusions 23 are formed at intervals in the circumferential direction. At least a portion of the locking protrusions 23 is at a height position that allows them to be locked with the locking projection 11 of the cap 1.

[0022] The bending rigidity of the cylindrical portion 30 is, for example, lower than the bending rigidity of the cylindrical portion 3 of the cap 1. The bending rigidity can be evaluated, for example, by a three-point bending test in accordance with JIS K7171:2016.

[0023] The spout 20 is formed of, for example, a synthetic resin such as polyethylene or polypropylene. The spout 20 is formed of, for example, low-density polyethylene. When low-density polyethylene is used, heat fusion to the container 200 becomes easy.

[0024] The cap 1 includes a top plate portion 2 and a cylindrical portion 3 . The top plate portion 2 has a circular shape. The top plate portion 2 is perpendicular to the central axis C1. An inner seal projection 12 is formed on the inner surface (lower surface) of the top plate portion 2. The inner seal projection 12 protrudes downward from the inner surface (lower surface) of the top plate portion 2. The inner seal projection 12 is formed in an annular or cylindrical shape. The inner seal projection 12 fits into the mouth portion 21 and abuts against the inner peripheral surface of the mouth portion 21. More specifically, the inner seal projection 12 abuts against the inner peripheral surface of the upward extension portion 28 or the second reduced diameter portion 27.

[0025] The tubular portion 3 hangs down from the peripheral edge of the top plate portion 2. The tubular portion 3 is formed in a cylindrical shape. The tubular portion 3 is divided by a score 6 (weakened portion) into a main portion 8 and a tamper-evidence ring portion (TE ring portion) 9. The TE ring portion 9 is connected to the lower end of the main portion 8 by a bridge 7.

[0026] A plurality of locking projections 11 are formed on the inner peripheral surface of the TE ring portion 9 (see FIG. 4). The locking projections 11 lock with the locking protrusions 23 of the spout 20 when the cap is opened to prevent the TE ring portion 9 from moving. The locking projections 11 extend in the circumferential direction. The multiple locking projections 11 are formed at intervals in the circumferential direction.

[0027] The main portion 8 includes a downward extension portion 15, an expanded diameter portion 16, and a main tube portion 17. The downward extension portion 15 is formed in a cylindrical shape extending downward from the periphery of the top plate portion 2. The expanded diameter portion 16 descends while expanding in diameter from the lower end of the downward extension portion 15. The main tube portion 17 is formed in a cylindrical shape extending downward from the lower end of the expanded diameter portion 16. A threaded portion 10 is formed on the inner peripheral surface of the main portion 8 (specifically, the inner peripheral surface of the main cylindrical portion 17). The threaded portion 10 is screwed into a male thread 22 of the spout 20.

[0028] The outer peripheral surface of the main portion 8 has an upper region 8A, a middle region 8B, and a lower region 8C. The upper region 8A is an annular region including the upper end of the outer peripheral surface of the main portion 8. The lower region 8C is an annular region including the lower end of the outer peripheral surface of the main portion 8. The middle region 8B is an annular region interposed between the upper region 8A and the lower region 8C. The middle region 8B is located lower than the upper region 8A and higher than the lower region 8C. The upper region 8A, the middle region 8B, and the lower region 8C are annular regions along the circumferential direction. The widths (height dimensions) of the upper region 8A, the middle region 8B, and the lower region 8C are constant in the circumferential direction.

[0029] An annular recess 13 is formed in a position on the outer peripheral surface of the main portion 8 including the upper end. The annular recess 13 is annular along the circumferential direction. The annular recess 13 is formed in the upper region 8A. The annular recess 13 is a recess formed by making the outer diameters of the downward extension portion 15 and the enlarged diameter portion 16 smaller than the outer diameter of the main tube portion 17.

[0030] The inner surface of the annular recess 13 has a first inner surface 13a and a second inner surface 13b. The first inner surface 13a has, for example, a curved convex shape when viewed from the circumferential direction. The first inner surface 13a is, for example, a curved convex surface whose inclination angle with respect to the top plate portion 2 increases from the upper end of the main portion 8 toward the radial expansion direction. The tangent direction at the lower end of the first inner surface 13a is approximately parallel to the up-down direction. The first inner surface 13a is the outer surface of the downward extension portion 15. The second inner surface 13b is, for example, linear when viewed in the circumferential direction. The second inner surface 13b is, for example, an inclined surface that descends while expanding in diameter from the lower end of the first inner surface 13a. The lower end of the second inner surface 13b reaches the lower edge of the upper region 8A. The second inner surface 13b is the outer surface of the expanding diameter portion 16.

[0031] As shown in FIGS. 1 and 2, an upper knurl 40 and a side knurl 50 are formed on the outer circumferential surface of the main portion 8. The side knurl 50 is formed in the middle region 8B of the outer circumferential surface of the main portion 8. The side knurl 50 has a plurality of side knurl protrusions 51. The side knurl protrusions 51 protrude radially outward from the middle region 8B. The side knurl protrusions 51 are formed linearly along the up-down direction from the upper portion to the lower portion of the middle region 8B. The multiple side knurl protrusions 51 are formed at intervals in the circumferential direction.

[0032] The protruding height of the side knurl protrusions 51 (height from the middle region 8B) is preferably 0.1 mm or more (preferably 0.3 mm or more). By setting the protruding height of the side knurl protrusions 51 within the above range, fingers can easily engage with the side knurl protrusions 51 when opening the bottle. The protruding height of the side knurl protrusions 51 can be, for example, 0.5 mm or less. By setting the protruding height of the side knurl protrusions 51 within the above range, pain in the fingers when opening the bottle can be alleviated.

[0033] The width of the side knurl protrusions 51 is preferably 0.2 mm or more (preferably 0.5 mm or more). The width of the side knurl protrusions 51 can be, for example, 1.5 mm or less. The pitch of the side knurl protrusions 51 is preferably 0.5 to 3 mm (preferably 1 to 3 mm). The pitch is the distance between the apexes of two adjacent side knurl protrusions 51 (circumferential distance). By setting the pitch of the side knurl protrusions 51 within the above range, fingers can be easily engaged with the side knurl protrusions 51 when opening the bottle, and pain in the fingers can be alleviated.

[0034] It is desirable that the upper ends of the side knurl protrusions 51 are located lower than the upper edge of the intermediate region 8B. The lower ends of the side knurl protrusions 51 reach the lower edge of the intermediate region 8B. The side knurls 50 are formed at a lower position than the upper knurl 40 .

[0035] The upper knurl 40 is formed in the upper region 8A of the outer circumferential surface of the main portion 8. The upper knurl 40 has a plurality of upper knurl protrusions 41. The upper knurl protrusions 41 protrude radially outward from the inner surface of the annular recess 13. The upper knurl protrusions 41 are formed from the upper end to the lower end of the annular recess 13. The plurality of upper knurl protrusions 41 are formed at intervals in the circumferential direction. The upper knurl protrusions 41 are formed, for example, in a plate shape perpendicular to the circumferential direction.

[0036] The upper knurl protrusion 41 has, for example, a curved convex shape protruding from the inner surface of the annular recess 13 when viewed in the circumferential direction. The outer edge of the upper knurl protrusion 41 curves, for example, so that the inclination angle with respect to the top plate portion 2 increases from the upper end of the main portion 8 toward the radially expanding direction. The tangent direction at the upper end of the outer edge of the upper knurl protrusion 41 is approximately parallel to the top plate portion 2. The tangent direction at the lower end of the outer edge of the upper knurl protrusion 41 is approximately parallel to the up-down direction.

[0037] The protruding height of the upper knurl convex portion 41 (the maximum height from the inner surface of the annular recess 13) is preferably 0.1 mm or more (preferably 0.3 mm or more). By setting the protruding height of the upper knurl convex portion 41 within the above range, it becomes easier for fingers to engage with the upper knurl convex portion 41 when opening the bottle. The protruding height of the upper knurl convex portion 41 can be, for example, 0.8 mm or less. By setting the protruding height of the upper knurl convex portion 41 within the above range, pain in the fingers when opening the bottle can be alleviated.

[0038] The width of the upper knurl convex portion 41 is preferably 0.1 mm or more. The width of the upper knurl convex portion 41 can be, for example, 1 mm or less. The pitch of the upper knurl convex portion 41 is preferably 0.5 to 3 mm (preferably 1 to 3 mm). The pitch is the distance between the apexes of two adjacent upper knurl convex portions 41 (circumferential distance). By setting the pitch of the upper knurl convex portion 41 within the above range, it becomes easier for fingers to engage with the upper knurl convex portion 41 when opening the bottle, and pain in the fingers can be alleviated.

[0039] It is desirable that the upper knurl 40 is located at a position spaced upward from the side knurl 50. If the upper knurl 40 is spaced from the side knurl 50, the user's fingers will be wedged between the upper knurl 40 and the side knurl 50 when gripping the cap 1. Therefore, the locking force at the lower end of the upper knurl protrusion 41 and the upper end of the side knurl protrusion 51 is increased. It is desirable that the radial position of the upper knurl protrusion 41 coincides with the radial position of the side knurl protrusion 51. It is preferable that the number of the upper knurl protrusions 41 is equal to the number of the side knurl protrusions 51. It is preferable that the pitch of the upper knurl protrusions 41 is equal to the pitch of the side knurl protrusions 51.

[0040] No knurls are formed in the lower region 8C. The lower region 8C is formed smoothly without any irregularities.

[0041] The height H1 of the cap 1 can be set to, for example, equal to or less than the radius R1 (half the outer diameter of the cap 1) of the cap 1. This can improve the storage capacity of the container with the closure structure (see FIG. 5). The cap 1 is formed of, for example, a synthetic resin such as polyethylene, polypropylene, etc. The cap 1 is formed of, for example, high-density polyethylene.

[0042] [Container with closure structure] FIG. 5 is a cross-sectional view of a container 200 to which the closure structure 100 is attached (a container with a closure structure). As shown in Fig. 5, the container 200 includes a bottom 201, a body 202, a pair of upper plate portions 203, and a joint portion 204. The bottom 201 is formed in a rectangular shape. The body 202 is formed in a rectangular tubular shape. The body 202 extends upward from the periphery of the bottom 201. The upper plate portion 203 extends obliquely upward from the upper end of the body 202. In detail, the upper plate portion 203 extends from two opposing edges 202a of the upper end of the body 202 in directions approaching each other while rising.

[0043] The joint portion 204 is formed by overlapping a first extending portion 204A and a second extending portion 204B and joining them to each other by fusion or the like. The first extending portion 204A extends upward from the upper end of one upper plate portion 203. The second extending portion 204B extends upward from the upper end of the other upper plate portion 203.

[0044] The container 200 is formed, for example, of a laminate sheet including a base material and a resin layer. The base material is formed of paper, resin, or the like. The resin layer is made of low-density polyethylene or the like. The resin layer is the innermost layer facing the internal space of the container 200. A container whose base material is formed of paper is a paper pack container. The laminate sheet may have a metal layer formed of an aluminum alloy or the like between the base material and the resin layer.

[0045] An insertion hole 205 is formed in one of the pair of upper plate portions 203. Mouth portion 21 of spout 20 is inserted into insertion hole 205. The upper surface of substrate portion 24 is placed on the inner surface of upper plate portion 203. The upper surface of substrate portion 24 contacts the inner surface of upper plate portion 203. Substrate portion 24 is attached to the inner surface of upper plate portion 203 by heat fusion or the like. More specifically, substrate portion 24 is heat fused to a resin layer provided on the inner surface of upper plate portion 203. Substrate portion 24 is joined to upper plate portion 203 in a liquid-tight manner.

[0046] The cap 1 has a low height. Therefore, when viewed from above the container 200, the cap 1 does not protrude outward from the side of the container 200. Therefore, multiple containers with closure structures can be stored side by side with no gaps. The cap 1 is located lower than the upper end of the joint 204. Therefore, multiple containers with closure structures can save space even when stacked one above the other. The container with the closure structure can store beverages such as fruit juice, tea, coffee, milk, and the like.

[0047] [How to use the closure structure] Next, a method for opening the cap 1 of the capping structure 100 will be described. A user grasps the cap 1. The user's fingers come into contact with the outer peripheral surface of the cap 1. More specifically, the user's fingers come into contact with the side knurl 50 and the upper knurl 40, and engage with the side knurl protrusion 51 and the upper knurl protrusion 41.

[0048] When the user turns the cap 1 in the opening direction, the main portion 8 rotates while the locking projection 11 locks with the locking protrusion 23. This prevents the TE ring portion 9 from rotating. A tensile force acts on the bridge 7 connecting the main portion 8 and the TE ring portion 9. This tensile force breaks the bridge 7, and the TE ring portion 9 is separated from the main portion 8. This clearly indicates that the cap 1 has been opened. As the main portion 8 rises, the inner seal projection 12 is pulled out of the mouth portion 21, and the sealing is released.

[0049] [Effects of the plugging structure of the embodiment] In the capping structure 100, not only the side knurls 50 but also the upper knurls 40 are formed on the outer peripheral surface of the main portion 8 of the cap 1. When a user holds the cap 1, the fingers of the user are engaged with the side knurls 50 and the upper knurl 40, enhancing the anti-slip effect. This makes it easy to open the cap 1.

[0050] A smooth lower region 8C is formed on the outer peripheral surface of the main portion 8 at a position lower than the side knurl 50. When a user grips the cap 1, the user's fingers bite into the lower region 8C, so that the locking force at the lower end of the side knurl protrusion 51 is increased.

[0051] In the plug structure 100, an annular recess 13 is formed in the upper region 8A of the main portion 8. The upper knurl protrusion 41 of the upper knurl 40 is formed to protrude from the inner surface of the annular recess 13. Therefore, the protruding dimension of the upper knurl protrusion 41 can be reduced without reducing the locking force. Therefore, the cap 1 can be made smaller.

[0052] The upper knurl protrusion 41 of the upper knurl 40 is formed in a plate shape perpendicular to the circumferential direction, so that the locking force when the user grips the cap 1 is increased.

[0053] In the capping structure 100, the mouth portion 21 of the spout 20 has a tubular portion 30 and a flange portion 29. The outer peripheral surface 29a of the flange portion 29 abuts against the inner peripheral surface of the main portion 8 of the cap 1. Since the outer peripheral surface 29a of the flange portion 29 is the main sealing surface, the contact area of ​​the sealing surfaces can be reduced. This makes it possible to reduce the opening torque of the cap 1. This makes it easier to open the cap 1. In the closure structure 100, the outer peripheral surface 29a, which has a small area, serves as the sealing surface, and the outward pressing force from the flange portion 29 is concentrated and acts to improve the adhesion between the outer peripheral surface 29a of the flange portion 29 and the inner peripheral surface of the main portion 8. Therefore, the sealing performance of the closure structure 100 can be improved.

[0054] The tubular portion 30 of the spout 20 comprises a main cylinder portion 26 and an upward extension portion 28. The outer diameter D1 of the upward extension portion 28 is equal to or smaller than the inner diameter D2 of the main cylinder portion 26. By making the upward extension portion 28 thinner, the rigidity of the mouth portion 21 can be increased. Therefore, even if the spout 20 is formed from a material (e.g., low-density polyethylene) that has a lower strength than the cap 1, the spout 20 can be given sufficient strength.

[0055] The bending rigidity of the cylindrical portion 30 of the spout 20 is preferably lower than the bending rigidity of the cylindrical portion 3 of the cap 1. This makes it easier for the cylindrical portion 30 to bend and deform radially inward. The radially inward deformation of the cylindrical portion 30 enhances the adhesion between the upward extension portion 28 and the inner seal projection 12. This enhances the sealing performance of the closure structure 100.

[0056] As for the specific configuration of the plug structure, the configurations given in the above-mentioned embodiments can be selected or changed to other configurations as appropriate without departing from the spirit of the present invention. The cross-sectional shape of the side knurl protrusion (the shape of the cross section perpendicular to the central axis of the cap) is not particularly limited. The cross-sectional shape of the side knurl protrusion can be, for example, an arc shape, a polygonal shape (for example, a triangular shape, a rectangular shape), or the like.

[0057] The shape of the upper knurl convex portion is not particularly limited. For example, the shape of the upper knurl convex portion as viewed from the circumferential direction is not limited to a curved convex shape, and may be a polygonal shape (e.g., a triangular shape, a rectangular shape, etc.). The cross-sectional shape of the upper knurl convex portion (the shape of the cross section perpendicular to the central axis of the cap) may be, for example, an arc shape, a polygonal shape (e.g., a triangular shape, a rectangular shape, etc.). The lower region of the main portion need not necessarily be formed with a knurled portion. The lower region is not limited to a cylindrical surface, but may be a flat surface or a shape formed by combining a plurality of flat surfaces.

[0058] In the embodiment of the plugging structure 100, the tubular portion 30 of the spout 20 includes a first reduced diameter portion 25, a main tubular portion 26, a second reduced diameter portion 27, and an upward extension portion 28, but it is also possible to have a configuration without the upward extension portion 28. In that case, the tubular portion has the first reduced diameter portion, the main tubular portion, and the second reduced diameter portion. The flange portion extends radially outward from the upper end of the second reduced diameter portion.

[0059] The cap of the embodiment has the following configuration: The cap has a top plate portion and a tubular portion hanging down from the periphery of the top plate portion, the tubular portion is partitioned into a main portion and a tamper evidence ring portion connected to the main portion by a bridge, a thread portion is formed on the inner peripheral surface of the main portion, and an upper knurl formed at a position including the upper end of the outer peripheral surface and a side knurl formed at a position lower than the upper knurl are formed on the outer peripheral surface of the main portion. [Explanation of symbols]

[0060] 1 Cap 2 Top plate 3 Cylinder part 7. Bridge 8 Main Section 8C lower area 9 TE Ring (Tamper Evidence Ring) 10 Threaded part 13 Annular recess 20 Spout 21 Mouth area 40 Upper Naal 41 Upper knurl convex part 50 Side Knurl

Claims

1. A cap and a spout having a mouth portion to which the cap is attached, The cap has a top plate portion and a tubular portion hanging down from a periphery of the top plate portion, The cylindrical portion is divided into a main portion and a tamper-evidence ring portion connected to the main portion by a bridge, A threaded portion is formed on an inner circumferential surface of the main portion, An upper knurl formed at a position including the upper end of the outer peripheral surface of the main portion and a side knurl formed at a position lower than the upper knurl are formed on the outer peripheral surface of the main portion. Closure structure.

2. A smooth annular lower region is formed on the outer peripheral surface of the main portion at a position lower than the side knurl. The closure structure of claim 1.

3. an annular recess is formed along a circumferential direction of the main portion at a position including the upper end of the outer circumferential surface of the main portion; The upper knurl has a plurality of upper knurl protrusions protruding from the inner surface of the annular recess. The closure structure of claim 1.

4. The upper knurl convex portion is a plate-like portion perpendicular to the circumferential direction. The closure structure of claim 3.

5. A plugging structure according to any one of claims 1 to 4, a container having the closure structure attached thereto; A container with a closure structure.

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