Cap and method for manufacturing the same

Abstract

To provide a cap and manufacturing method therefor, capable of completely preventing drop-off of a seal member without damaging a skirt part.SOLUTION: A cap 1 includes: a cap body 11 with a top plate part 21 and a cylindrical skirt p-art 22 mounted on the top plate part 21; a seal member 12 separated from the cap body 11 and mounted in the cap body 11 to face the top plate part 21; a plurality of locking parts 31 in the peripheral direction of the skirt part 22 and supporting the seal member 12 while projecting inward in the radial direction of the skirt part 22; a plurality of small-diameter parts 35a provided between the locking part 31 and the top plate part 21 of the skirt part 22, and provided respectively on the sides of the top plate part 21 of the locking part 31 in the axial direction; and a plurality of large-diameter parts 35b provided adjacent to the small-diameter part 35a in the peripheral direction and each having an inscribed circle diameter larger than the inscribed circle diameter of each of the plurality of small-diameter parts 35a.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a cap for sealing a can container containing a beverage and a method for manufacturing the cap. [Background technology]

[0002] Conventionally, caps for sealing the mouth of can containers have been configured to have a sealing member made of a resin material attached to the inner surface of the cap body so as to be in close contact with the mouth. For such caps, a technique is known in which the cap body and the sealing member are not bonded to each other in order to reduce the opening torque required when opening the cap (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-217295 A [Patent Document 2] JP 2017-178421 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned cap, the sealing member is engaged with the vent slit protruding inwardly from the skirt portion to prevent it from falling off. However, when the pressure inside the container becomes negative, the sealing member tends to stick to the mouth of the container, and there is a risk that the sealing member will fall off from the cap body when the container is opened.

[0005] On the other hand, if the vent slit is formed deep in the radial direction in order to sufficiently lock the sealing member, there is a risk of cracks occurring at the end of the vent slit. It is also possible to provide a recess in the skirt portion that protrudes inward from the skirt portion that does not have a slit. However, even if the sealing member is locked by a recess provided in the skirt portion, if the recess is formed too deep, there is a risk of the skirt portion being damaged.

[0006] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a cap that can reliably prevent a sealing member from falling off without damaging the skirt portion, and a method for manufacturing the cap. [Means for solving the problem]

[0007] A cap according to one aspect of the present invention includes a cap body having a top plate portion and a cylindrical skirt portion provided on a peripheral portion of the top plate portion, a sealing member provided within the cap body separately from the cap body and facing the top plate portion, a plurality of locking portions provided in a circumferential direction of the skirt portion, the locking portions protruding radially inward from the skirt portion to support the sealing member, and Multiple a plurality of small diameter portions provided between the locking portion and the top plate portion, each of which is provided on the top plate portion side of the locking portion in the axial direction; and a plurality of large diameter portions provided adjacent to the small diameter portions in the circumferential direction, each of which has an inscribed circle diameter larger than the inscribed circle diameters of the plurality of small diameter portions. The small diameter portion is adjacent to the locking portion and the top plate portion. .

[0008] A method for manufacturing a cap according to one embodiment of the present invention includes placing a molded product having a top plate portion and a skirt portion formed integrally with the top plate portion via annular and curved corners on a first tool having multiple first protrusions on its outer peripheral surface, as well as multiple large diameter portion molding portions adjacent to the first protrusions in the axial direction and a small diameter portion molding portion adjacent to the large diameter portion molding portion in the circumferential direction, and rotating the first tool and a second tool having second protrusions arranged between adjacent first protrusions of the first tool relatively to insert the second protrusions between the adjacent first protrusions to mold multiple recesses, multiple small diameter portions, and multiple large diameter portions in the skirt portion. Effect of the Invention

[0009] According to the present invention, it is possible to provide a cap and a method for manufacturing a cap that can reliably prevent a sealing member from falling off without damaging a skirt portion. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic configuration of a cap and a can container according to an embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. 4 is an enlarged cross-sectional view showing the configuration of the cap. [Figure 6] FIG. 4 is an enlarged cross-sectional view showing the configuration of the cap. [Figure 7] FIG. [Figure 8] 5A to 5C are explanatory diagrams showing an example of a manufacturing method of the cap. [Figure 9] 5A to 5C are explanatory diagrams showing an example of a manufacturing method of the cap. [Figure 10] FIG. 4 is an explanatory diagram showing an example of a manufacturing device for the cap. [Figure 11] FIG. 4 is a cross-sectional view showing an example of a manufacturing apparatus for the cap. [Figure 12] FIG. 4 is a cross-sectional view showing an example of a manufacturing apparatus for the cap. [Figure 13] FIG. 4 is a cross-sectional view showing an example of a manufacturing apparatus for the cap. [Figure 14] FIG. 2 is a perspective view showing a configuration of a first tool of the manufacturing apparatus. [Figure 15] FIG. 2 is an enlarged perspective view showing the configuration of the first tool. [Figure 16] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a cap 1, a manufacturing method for the cap 1, and a manufacturing apparatus 200 for the cap 1 according to one embodiment of the present invention will be described with reference to FIGS. Fig. 1 is a cross-sectional view showing a schematic configuration of a cap 1 and a can container 100 according to one embodiment of the present invention, Fig. 2 is a perspective view showing the configuration of the cap 1, Fig. 3 is a side view showing the configuration of the cap 1, and Fig. 4 is a cross-sectional view showing the configuration of the cap 1. Fig. 5 is a cross-sectional view showing an enlarged view of a portion V in Fig. 4, showing the configuration of the cap 1, and Fig. 6 is a cross-sectional view showing an enlarged view of a portion VI in Fig. 4, showing the configuration of the cap 1. Fig. 7 is a cross-sectional view showing the configuration of the cap 1 along the line VII-VII in Fig. 4.

[0012] Fig. 8 and Fig. 9 are explanatory views showing an example of a manufacturing method for the cap 1. Fig. 10 is an explanatory view showing the configuration of an example of a manufacturing apparatus 200 for the cap 1, and Figs. 11 to 13 are cross-sectional views showing the example of the manufacturing apparatus 200 in different positions. Fig. 14 is a perspective view showing the configuration of a first tool 211 used in the manufacturing apparatus 200, and Fig. 15 is a perspective view showing the configuration of the first tool 211 in an enlarged manner in the same position as in Fig. 11. Fig. 16 is a perspective view showing the configuration of the first tool 211 in a position different from that in Fig. 11.

[0013] As shown in Fig. 1, the cap 1 is fastened by wrapping around a mouth portion 110 of a can container 100 in a capping state, thereby sealing the mouth portion 110. First, the can container 100 will be described with reference to Fig. 1.

[0014] As shown in FIG. 1, the can container 100 is a so-called bottle-shaped container for containing beverages and the like. For example, the can container 100 is made of a metal material such as an aluminum alloy or a surface-treated steel plate with resin films laminated on both sides. The can container 100 is formed into a cylindrical shape having a different outer diameter with one end being reduced in diameter. The can container 100 has a mouth portion 110 at one end for discharging the contained beverage. The mouth portion 110 has a jaw portion 111, a male screw portion 112, and a curl portion 113 on its outer circumferential surface from the bottom side of the can container 100 toward the end.

[0015] The jaw portion 111 is configured to protrude in an annular shape. The curled portion 113 is formed to have a smaller diameter than the male screw portion 112. The curled portion 113 is also configured to be smaller than the inner diameter of the cap 1. The curled portion 113 is formed by bending the end of the mouth portion 110 one or more times. The curled portion 113 forms an opening for discharging the beverage stored in the can container 100.

[0016] As shown in FIGS. 1 to 6, the cap 1 includes a cap body 11 and a sealing member 12 provided separately within the cap body 11.

[0017] The cap body 11 is made of a material in which a resin coating layer is formed on a metal material such as an aluminum alloy. The cap body 11 is formed into a cup shape by forming the thin, flat plate-like material by various forming processes such as drawing, knurling, roll-on forming, and press forming.

[0018] 1 to 4, the cap body 11 includes a disk-shaped top plate portion 21 and a cylindrical skirt portion 22 that hangs down from the peripheral edge of the top plate portion 21. The cap body 11 is configured such that the top plate portion 21 and the skirt portion 22 are integrally formed continuously with a circular ring-shaped, curved corner portion 23.

[0019] The top plate portion 21 is formed in a disk shape. As shown in Figures 1 and 4, the main surface of the top plate portion 21 is formed in a flat shape. Note that the top plate portion 21 may be partially embossed or debossed.

[0020] The skirt portion 22 has one end connected to the top plate portion 21 via a corner portion 23, and the other end open. As shown in Figures 1 to 4, the skirt portion 22 has a plurality of locking portions 31, a plurality of vent slit portions 32, a female screw portion 33, a tamper evidence band portion 34, and an upper annular portion 35. In the skirt portion 22, for example, the upper annular portion 35, the plurality of locking portions 31, the plurality of vent slit portions 32, the female screw portion 33, and the tamper evidence band portion 34 are formed in this order between the end portion on the top plate portion 21 side and the open end portion.

[0021] By performing processes such as knurling and roll-on molding on the cup-shaped molded product 11A, which is composed of the top plate portion 21, the cylindrical skirt portion 22 in which the multiple engagement portions 31, the multiple vent slit portions 32, the female screw portion 33, and the tamper evidence band portion 34 are not formed, and the corner portion 23, the multiple engagement portions 31, the multiple vent slit portions 32, the female screw portion 33, and the tamper evidence band portion 34 are formed in the skirt portion 22. In addition, the female screw portion 33 is formed in a state in which the cap 1 is attached to the can container 100.

[0022] The multiple locking portions 31 restrict the movement of the sealing member 12 and hold the sealing member 12 by recessing the skirt portion 22 radially inward. The locking portions 31 are recesses in which no slits penetrating the skirt portion 22 are formed. As shown in FIG. 5, the locking portions 31 have an upper inclined surface 31a that is inclined downward from the upper annular portion 35 toward the radial inside of the cap 1 in the vertical cross section, and a lower inclined surface 31b that is inclined upward from the skirt portion 22 below the locking portions 31 toward the radial inside of the cap 1 in the vertical cross section. The multiple locking portions 31 restrict the movement of the sealing member 12 and hold the sealing member 12 by locking the sealing member 12 to the inner surfaces of the multiple upper inclined surfaces 31a.

[0023] 6, the vent slit portion 32 has a recess 32a and a vent slit 32b formed in a part of the recess 32a. The vent slit portion 32 protrudes from the inner peripheral surface of the skirt portion 22. The vent slit 32b is a cut that exhausts gas from within the can container 100 when the can container 100 is opened.

[0024] For example, in this embodiment, the locking portions 31 are provided at 13 locations and the vent slit portions 32 are formed at four locations in the circumferential direction of the skirt portion 22. The multiple vent slit portions 32 are set at equal or nearly equal intervals in the circumferential direction of the skirt portion 22, and the multiple locking portions 31 and the multiple vent slit portions 32 are set at equal or nearly equal intervals in the circumferential direction of the skirt portion 22. The multiple locking portions 31 are provided closer to the top plate portion 21 (upper annular portion 35) in the axial direction of the skirt portion 22 than the multiple vent slit portions 32.

[0025] The female screw portion 33 is configured to be capable of screwing into the male screw portion 112 of the can container 100. The female screw portion 33 is molded together with the can container 100. That is, the female screw portion 33 is not molded in the completed product of the cap 1 before it is attached to the can container 100, but is molded when it is combined integrally with the can container 100.

[0026] The tamper evidence band portion 34 engages with the jaw portion 111 of the can container 100 in the direction in which the cap 1 moves away from the can container 100 and in the axial direction of the cap 1. The tamper evidence band portion 34 also has a breaking portion 34a that breaks when the cap 1 is opened and is detached from the skirt portion 22. That is, the tamper evidence band portion 34 is configured by forming a slit on the end side of the skirt portion 22 while leaving the breaking portion 34a, and similarly to the female screw portion 33, when combined integrally with the can container 100, it is shaped into the shape of the jaw portion 111 of the can container 100, thereby engaging with the jaw portion 111.

[0027] The upper annular portion 35 is formed in a portion located between the top plate portion 21 and the multiple locking portions 31 of the skirt portion 22. For example, the upper annular portion 35 is formed in a part of the corner portion 23. The upper annular portion 35 has multiple small diameter portions 35a and multiple large diameter portions 35b in the circumferential direction. The inscribed circle diameters (inner diameters) of the multiple small diameter portions 35a are relatively smaller than the inscribed circle diameters (inner diameters) of the multiple large diameter portions 35b.

[0028] The small diameter portion 35a is adjacent to the locking portion 31 in the axial direction of the cap 1. The inscribed circle diameters (inner diameters) of the multiple small diameter portions 35a are set to be smaller than the outer diameter of the sealing member 12, and the inscribed circle diameters (inner diameters) of the multiple large diameter portions 35b are set to be larger than the outer diameter of the sealing member 12.

[0029] When the multiple locking portions 31 are molded, the multiple small diameter portions 35a are formed in the upper annular portion 35 by drawing in and recessing the portions of the upper annular portion 35 adjacent to the upper portions of the respective locking portions 31 in the radially inward direction. Also, the upper annular portion 35 has multiple large diameter portions 35b in the portions where the multiple small diameter portions 35a are not formed, i.e., between the multiple small diameter portions 35a in the circumferential direction.

[0030] In this embodiment, the multiple vent slit portions 32 are set at equal or nearly equal intervals in the circumferential direction of the skirt portion 22, and the multiple locking portions 31 and the multiple vent slit portions 32 are set at equal or nearly equal intervals in the circumferential direction of the skirt portion 22. Therefore, the circumferential length of the large diameter portion 35b corresponding to the portion where the two locking portions 31 are adjacent in the circumferential direction of the skirt portion 22 is shorter than the circumferential length of the large diameter portion 35b corresponding to the portion where the two locking portions 31 between which the vent slit portion 32 is arranged are adjacent in the circumferential direction of the skirt portion 22.

[0031] 4, the sealing member 12 is formed separately from the cap body 11. The sealing member 12 is disk-shaped with an outer diameter larger than the inscribed circle diameter of the multiple locking portions 31 provided on the skirt portion 22 of the cap body 11 and the inscribed circle diameter of the multiple small diameter portions 35a. The sealing member 12 is provided integrally with the cap body 11 by engaging the upper inclined surface 31a of the locking portion 31, which protrudes radially from the inner peripheral surface of the skirt portion 22, with the cap body 11 in the axial direction.

[0032] 1 and 4 to 6, the sealing member 12 includes a disk-shaped sliding layer 41 and a disk-shaped sealing layer 42 laminated integrally with the sliding layer 41. In the sealing member 12, the sliding layer 41 and the sealing layer 42 are formed of different synthetic resins. In the sealing member 12, the sealing layer 42 is laminated integrally with the sliding layer 41.

[0033] 1, the sealing member 12 has a flat plate portion 12a in which the area contacting the mouth portion 110 on the outer periphery side is formed thicker than the central side, and a curved surface portion 12b in which the outer surface of the outer periphery on the top plate portion 21 side is formed as a curved surface. In other words, the sealing member 12 is formed in a disk shape, and the ridge portion on the top plate portion 21 side is formed as a curved surface with a predetermined curvature. Note that the sealing member 12 may have a configuration in which the thickness of the flat plate portion 12a is formed uniformly, for example.

[0034] The sliding layer 41 is made of a resin material that is relatively harder (harder) than the sealing layer 42. The sliding layer 41 is also made of a resin material that is not adhesive or sticky to the resin film layer of the cap body 11. That is, the sliding layer 41 is not adhesive to the top plate portion 21, and slides on the top plate portion 21 while being in contact with the top plate portion 21.

[0035] Examples of the resin material used for the sliding layer 41 include olefin resins such as polypropylene resin and polyethylene resin, polyester resins such as polyethylene terephthalate, styrene resins, and acrylic resins. In this embodiment, the sliding layer 41 is made of, for example, polypropylene resin. Note that, the resin material used for the sliding layer 41 may contain appropriate additives such as pigments, lubricants, and softeners. In this embodiment, the hardness of the sliding layer 41 is D10 to D70 in terms of durometer D hardness according to JIS-K7215.

[0036] As shown in FIG. 1 and FIG. 4 to FIG. 6, the sliding layer 41 is provided separately from the cap body 11, facing the top plate portion 21 of the cap body 11. The sliding layer 41 is configured to be slidable with the top plate portion 21 of the cap body 11 by the resin material used. The sliding layer 41 is configured in a disk shape. The outer diameter of the sliding layer 41 is smaller than the inner diameter of the skirt portion 22. The outer diameter of the sliding layer 41 is larger than the inscribed circle of the multiple engagement portions 31 and the inscribed circle of the multiple small diameter portions 35a, and is smaller than the inscribed circle of the multiple large diameter portions 35b. The outer diameter of the sliding layer 41 is configured to be larger than the outer diameter of the curl portion 113 of the mouth portion 110.

[0037] 5 and 6, the sliding layer 41 includes, for example, a first flat plate portion 41a having a uniform thickness, and a first curved surface portion 41b having a curved outer surface of the outer periphery on the top plate portion 21 side. In addition, for example, the sliding layer 41 includes a protrusion portion 41c provided on the sealing layer 42 side of the first curved surface portion 41b. The first flat plate portion 41a has a uniform thickness from the center of the sliding layer 41 to the outer periphery side of the portion facing the curled portion 113 of the mouth portion 110.

[0038] The first curved surface portion 41b is configured such that the thickness of a portion from the outer periphery side of the portion facing the curled portion 113 of the mouth portion 110 to the outer periphery gradually decreases toward the outer periphery. The protrusion portion 41c is configured in the shape of an annular protrusion that is inclined with respect to the axial direction of the sliding layer 41 and the surface direction of the top plate portion 21 and curved or inclined toward the end side where the skirt portion 22 opens. The thickness of the protrusion portion 41c gradually decreases from the first curved surface portion 41b toward the tip.

[0039] The sealing layer 42 is made of a resin material that is relatively lower in hardness (softer) than the sliding layer 41. Examples of the resin material used for the sealing layer 42 include olefin resins, polyester resins, styrene resins, and acrylic resins, and more preferably, a blend of a styrene elastomer and a polypropylene resin, a blend of a low-density polyethylene and a styrene elastomer, and a polyester elastomer. The resin material used for the sealing layer 42 has adhesive properties with the resin material used for the sliding layer 41. In this embodiment, the sealing layer 42 is made of, for example, a blend of a styrene elastomer and a polypropylene resin. Note that a pigment, a lubricant, a softener, and the like can be appropriately added to the resin material used for the sealing layer 42.

[0040] As shown in Figs. 1, 4 to 6, the sealing layer 42 is integrally provided on the main surface of the sliding layer 41 facing the mouth portion 110. The sealing layer 42 is configured in a disk shape. The outer diameter of the sealing layer 42 is smaller than the inner diameter of the skirt portion 22. The outer diameter of the sealing layer 42 is larger than the inscribed circle of the multiple engagement portions 31 and the inscribed circle of the multiple small diameter portions 35a, and is smaller than the inscribed circle of the multiple large diameter portions 35b. The outer diameter of the sealing layer 42 is configured to be larger than the outer diameter of the curl portion 113 of the mouth portion 110. The outer diameter of the sealing layer 42 is set to be the same as the outer diameter of the sliding layer 41, for example.

[0041] As shown in Figs. 5 and 6, the sealing layer 42 includes a second flat plate portion 42a having a uniform thickness, a second curved surface portion 42b having a curved outer surface of the outer periphery on the top plate portion 21 side, and a thick portion 42c provided on the second flat plate portion 42a. The second flat plate portion 42a has a flat main surface facing the curled portion 113. For example, the second flat plate portion 42a is configured to have the same diameter as the first flat plate portion 41a of the sliding layer 41. The second flat plate portion 42a, together with the first flat plate portion 41a, constitutes the flat plate portion 12a of the sealing member 12. In this embodiment, the first flat plate portion 41a and the second flat plate portion 42a are set to have the same thickness, for example.

[0042] The second curved surface portion 42b has, for example, a main surface that is flush with the main surface of the second flat plate portion 42a that faces the curled portion 113. The second curved surface portion 42b is configured such that the thickness of a portion from the outer periphery side of the portion that faces the curled portion 113 of the mouth portion 110 to the outer periphery gradually decreases toward the outer periphery. The second curved surface portion 42b is layered on the first curved surface portion 41b and the protruding portion 41c. The second curved surface portion 42b constitutes the curved surface portion 12b of the sealing member 12 together with the first curved surface portion 41b and the protruding portion 41c.

[0043] The thick portion 42c is a circular protrusion protruding from the main surface of the second flat portion 42a opposite to the sliding layer 41. The thick portion 42c constitutes a sealing portion that abuts against the mouth portion 110 of the can container 100. The sliding layer 41 may be configured to have a thin portion that is a recess in a portion facing the thick portion 42c, so that the thick portion 42c protrudes in a circular shape from both main surfaces of the second flat portion 42a, thereby ensuring a crushing allowance for the thick portion 42c.

[0044] The sliding layer 41 and the sealing layer 42 are configured such that the first curved surface portion 41b, the protruding portion 41c, and the second curved surface portion 42b are thinner than the first flat plate portion 41a and the second flat plate portion 42a, respectively.

[0045] Next, a method for manufacturing the cap 1 thus configured will be described with reference to FIGS.

[0046] First, a sheet-shaped metal material is squeezed by a shell press device to form the molded product 11A (step ST1). Next, a slide layer forming device forms the slide layer 41 on the top plate portion 21 of the molded product 11A (step ST2).

[0047] Next, the sealing layer 42 is formed on the sliding layer 41 in the molded product 11A by the sealing layer forming device (step ST3), whereby the sealing member 12 is formed in the molded product 11A.

[0048] Next, the sealing member 12 in the molded product 11A is removed by the sealing member transport device (step ST4). Next, the molded product processing device molds a plurality of locking portions 31, a plurality of vent slit portions 32, a tamper evidence band portion 34, and an upper annular portion 35 in the molded product 11A from which the sealing member 12 has been removed (step ST5).

[0049] Next, the sealing member 12 is inserted into the molded product 11A having the multiple locking portions 31, the multiple vent slit portions 32, the tamper-evidence band portion 34, and the upper annular portion 35 by a sealing member conveying device (step ST6). Through these steps, the cap 1 is manufactured (step ST7).

[0050] For example, the manufactured caps 1 are collected in a collection section. When a certain number of caps 1 are collected, they are transported to the next process, an inspection and packaging process, where they are inspected for quality and packaged.

[0051] Next, a method of capping the mouth 110 of the can container 100 with the manufactured cap 1 will be described. For example, the cap 1 is placed on the mouth 110 of the can container 100 so that the curled portion 113, which is the tip of the mouth 110 of the can container 100, comes into contact with the sealing layer 42 of the sealing member 12. In this state, a load is applied to the top plate portion 21 of the cap body 11, and the skirt portion 22 is rolled on while drawing the corner portion 23 downward (toward the can container 100). As a result, as shown in FIG. 1, a female screw portion 33 is formed in the skirt portion 22 of the cap 1, and the cap 1 is fixed to the mouth 110 of the can container 100 by rolling and tightening. This capping method is performed in a state where the can container 100 is filled with a beverage. In addition, for example, the can container 100 capped with the cap 1 is subjected to a retort process depending on the contents.

[0052] Next, an example of the configuration of a manufacturing apparatus 200 that is used in a molded product processing apparatus and that molds the multiple engagement portions 31, the multiple vent slit portions 32, and the upper annular portion 35 of the cap 1 in the above-mentioned step ST5 will be described with reference to Figures 10 to 16.

[0053] 11 to 13, in order to explain the combination of the first tool 211 and the second tool 212 at each position, Fig. 10 is labeled with a, b, and c to define the position of each tool 211, and A, B, and C to define the position of 212. Fig. 11 shows a cross section in which the tools 211 and 212 are combined at aA, Fig. 12 shows a cross section in which the tools 211 and 212 are combined at bB, and Fig. 13 shows a cross section in which the tools 211 and 212 are combined at cC.

[0054] 10 to 16, the manufacturing apparatus 200 includes a first tool 211, a second tool 212, and a driving device 213. The manufacturing apparatus 200 is an apparatus that performs knurling on the skirt portion 22 of the cap body 11 (molded product 11A) to form a plurality of engagement portions 31, a plurality of vent slit portions 32, a tamper evidence band portion 34, a plurality of small diameter portions 35a, and a plurality of large diameter portions 35b in the skirt portion 22. The manufacturing apparatus 200 molds a portion of the skirt portion 22 located between the first tool 211 and the second tool 212 by, for example, relatively rotating the first tool 211 and the second tool 212 by the driving device 213.

[0055] 10 to 16, the first tool 211 includes a first base 221, a plurality of first projections 222, a plurality of cutter portions 223, a plurality of small diameter portion molding portions 224, a plurality of large diameter portion molding portions 225, a first tamper evidence band portion molding portion 226 provided on the first base 221, and a rotation shaft 227 provided on the first base 221. In the first tool 211, the first base 221 and the plurality of first projections 222 are disposed within the cap body 11. The first tool 211 is constructed by combining a plurality of parts.

[0056] The first base portion 221 is disposed within the skirt portion 22 of the cap body 11. The first base portion 221 is cylindrical with an outer diameter smaller than the inner diameter of the skirt portion 22. The first base portion 221 has, for example, a hole 221a into which the rotating shaft 227 is inserted. The hole 221a has, for example, a key groove.

[0057] The first protrusion 222 is, for example, a semi-cylindrical shape whose axial direction is aligned with the axial direction of the first base portion 221, or a triangular prism shape with both portions curved. The first protrusions 222 are spaced apart from each other at a predetermined interval in the circumferential direction. Here, the predetermined interval is set to a width larger than the circumferential width of a second protrusion 232 of the second tool 212, which will be described later.

[0058] The cutter portion 223 is a protrusion that, together with the second protrusion 232 of the second tool 212, shears, breaks or cuts the portion where the vent slit 32b of the skirt portion 22 is to be formed. The cutter portion 223 is provided on one end side of adjacent first protrusions 222 among the multiple first protrusions 222 and between the adjacent first protrusions 222.

[0059] The small diameter portion molding portion 224 is a recess provided adjacent to the end side in the axial direction from the first protrusion 222 of the first base portion 221. The large diameter portion molding portion 225 is a protrusion formed adjacent to the small diameter portion molding portion 224 in the circumferential direction. In addition, the large diameter portion molding portion 225 is provided in a range adjacent to the cutter portion 223 in the axial direction. Such a plurality of small diameter portion molding portions 224 and a plurality of large diameter portion molding portions 225 are unevennesses provided in the circumferential direction at the end portion of the first base portion 221.

[0060] The first tamper evidence band portion molding portion 226 molds the skirt portion 22 into the shape of the tamper evidence band portion 34, and also forms slits intermittently to form a plurality of breakage portions 34a.

[0061] The rotating shaft 227 is fixed to a hole 221a of the first base portion 221. The rotating shaft 227 is connected to the driving device 213.

[0062] The second tool 212 is disposed on the outer peripheral surface side of the skirt portion 22, and is a tool that, together with the first tool 211, forms the plurality of engagement portions 31, the plurality of vent slit portions 32, the tamper evidence band portion 34, the plurality of small diameter portions 35a, and the plurality of large diameter portions 35b in the skirt portion 22. As shown in Figs. 10 to 16, the second tool 212 includes a second base portion 231, a plurality of second protrusions 232, and a second tamper evidence band portion forming portion 233 provided on the second base portion 231.

[0063] The second base 231 is, for example, an arc plate shape. The outer diameter of the second base 231 is set to be, for example, larger than the outer diameter of the first base 221 and the outer diameter of the skirt portion 22. The second base 231 may be disk-shaped, quarter-circular, or semicircular as long as it has an outer peripheral surface with a curvature that can suitably form the multiple locking portions 31, the multiple vent slit portions 32, the multiple small diameter portions 35a, and the multiple large diameter portions 35b together with the first tool 211. The second base 231 may be rotatable, or may be configured not to rotate when the first base 221 rotates.

[0064] The second protrusion 232 has, for example, a curved tip and one end side in the axial direction (the top plate portion 21 side of the skirt portion 22) formed on a flat surface. The second protrusion 232 is formed in a shape whose width gradually narrows in the axial direction and in a direction perpendicular to the axial direction toward the tip.

[0065] 10, the second protrusion 232 includes, for example, a first tooth 232A that forms the vent slit portion 32 and a second tooth 232B that forms the locking portion 31. Here, the first tooth 232A and the second tooth 232B are formed in different shapes so that the vent slit portion 32 and the locking portion 31 can be suitably formed, respectively, but may be the same shape as long as the locking portion 31 and the vent slit portion 32 can be suitably formed.

[0066] The second tamper evidence band portion molding portion 233, together with the first tamper evidence band portion molding portion 226, molds the skirt portion 22 into the shape of the tamper evidence band portion 34, and forms slits intermittently to form multiple breakage portions 34a.

[0067] The second projections 232 have their end faces at the tips inserted between the adjacent first projections 222 to press the skirt portion 22 and form the recesses. As a specific example of step ST5 of the above-mentioned manufacturing method, the first tool 211 and the second tool 212 are moved relative to each other in a state where the first base portion 221 of the first tool 211 is inserted into the molded product 11A. Then, as shown in Figs. 11 to 13, the end faces at the tips of the second projections 232 are inserted between the adjacent first projections 222 in sequence to press the skirt portion 22. At this time, the end faces of the second projections 232 are located closer to the center of the first base portion 221 than the outer surface of the small diameter portion molding portion 224 in the radial direction of the first tool 211.

[0068] For example, when the cutter portion 223 is adjacent to adjacent first protrusions 222 in the axial direction, as shown in Figure 11, a vent slit 32b is formed in a part of the recess by the cutter portion 223 and the first tooth 232A of the second protrusion 232 when the recess is molded, and the recess constitutes the vent slit portion 32.

[0069] When the cutter portion 223 is not adjacent to the ends of the first protrusions 222 adjacent in the axial direction, the recess formed by the second teeth 232B of the second protrusion 232 constitutes the locking portion 31 as shown in FIG. 12.

[0070] At this time, as shown in Fig. 12, the second projection 232 moves the portion of the skirt portion 22 that constitutes the upper annular portion 35 on the top plate portion 21 side toward the small diameter portion forming portion 224, which is a recess. As a result, the portion adjacent to the locking portion 31 of the skirt portion 22 on the top plate portion 21 side is pulled toward the small diameter portion forming portion 224 and plastically deformed to be recessed, forming the small diameter portion 35a. In addition, the portion adjacent to the small diameter portion 35a in the circumferential direction is pressed against the large diameter portion forming portion 225, and the large diameter portion 35b is formed adjacent to the small diameter portion 35a. Note that the portion adjacent to the vent slit portion 32 of the upper annular portion 35 is formed as the large diameter portion 35b.

[0071] The driving device 213 is a driving source that rotates the first tool 211 and the second tool 212 relatively. The driving device 213 rotates, for example, the rotating shaft 227. The driving device 213 is, for example, a motor or a transmission mechanism that transmits the rotation of the motor to the rotating shaft 227. The driving device 213 rotates the first tool 211 in one direction.

[0072] The driving device 213 may be configured to rotate the first tool 211 and the second tool 212 relatively, and may be configured to rotate the second base 231 of the second tool 212 instead of rotating the first base 221 via the rotation shaft 227 of the first tool 211, or may rotate both the first base 221 and the second base 231. The driving device 213 may be configured to be movable between, for example, an initial position where the cap body 11 is placed on the first tool 211, and a molding position where the first tool 211 and the second tool 212 are in a predetermined positional relationship and the cap body 11 is molded.

[0073] The cap 1 and the manufacturing method of the cap 1 thus configured have a small diameter portion 35a in the skirt portion 22 (upper annular portion 35) between the multiple locking portions 31 and the top plate portion 21, the inner diameter of which above the locking portions 31 is smaller than the inner diameter above the portion where the locking portions 31 are not formed. Therefore, the metal material that was at the position where the small diameter portion 35a is to be formed before the small diameter portion 35a is formed is drawn radially inward when the locking portions 31 are formed. Therefore, the locking portions 31 can be formed deep radially inward without damaging the skirt portion 22, and the inscribed circle diameter of the multiple locking portions 31 can be made small. That is, the inscribed circle diameter of the multiple locking portions 31 can be made smaller than the outer diameter of the sealing member 12. Since the sealing member 12 can be supported by the multiple locking portions 31, it is possible to reliably prevent the sealing member 12 from falling off the cap body 11.

[0074] Moreover, by setting the inner diameter of the inscribed circle of the small diameter portions 35a smaller than the outer diameter of the sealing member 12, the inner peripheral surface of the small diameter portion 35a abuts against the outer peripheral edge of the sealing member 12, so that the inner peripheral surface of the small diameter portion 35a holds the sealing member 12. Thus, in addition to being supported by the multiple locking portions 31, the cap body 11 can fix the outer peripheral portion of the sealing member 12 by the small diameter portion 35a, and can more reliably prevent the sealing member 12 from falling off from the cap body 11. In addition, the sealing member 12 arranged in the cap body 11 is aligned in the radial direction by the inner peripheral surfaces of the small diameter portions 35a. Thus, when the cap 1 is attached to the can container 100, the thick portion 42c of the sealing member 12 reliably faces the mouth portion 110 of the can container 100, so that the cap 1 can reliably seal the can container 100.

[0075] As described above, according to the cap 1 and the manufacturing method of the cap 1 according to one embodiment of the present invention, it is possible to form a plurality of locking portions 31 that support the sealing member 12 without damaging the skirt portion 22, and to make the locking portions 31 deep. Therefore, the cap 1 and the manufacturing method of the cap 1 can reliably prevent the sealing member 12 from falling off the cap body 11.

[0076] The present invention is not limited to the above-described embodiment. For example, in the above-described example, one example of the number of the plurality of locking portions 31 and the plurality of vent slit portions 32 was given, but the number of the locking portions 31 and the vent slit portions 32 can be set as appropriate. That is, the number of the locking portions 31 and the vent slit portions 32 may be the same, or the number of the locking portions 31 may be more or less than the number of the vent slit portions 32. The shapes of the locking portions 31 and the vent slit portions 32 can also be set as appropriate. The position and opening area of ​​the vent slits 32b of the vent slit portions 32 can also be set as appropriate.

[0077] In other words, as long as the sealing member 12 can be supported by multiple engaging portions 31, the number and shape of the engaging portions 31 and vent slit portions 32 can be appropriately set depending on the shape of the cap 1 and the can container 100, the contents to be contained in the can container 100, the internal pressure within the can container 100, etc.

[0078] That is, the present invention is not limited to the above-mentioned embodiment, and various modifications can be made in the implementation stage without departing from the gist of the invention. In addition, the embodiments may be implemented in appropriate combination, and in that case, the combined effect can be obtained. Furthermore, the above-mentioned embodiment includes various inventions, and various inventions can be extracted by combinations selected from the multiple components disclosed. For example, if the problem can be solved and the effect can be obtained even if some components are deleted from all the components shown in the embodiment, the configuration from which the components are deleted can be extracted as an invention. The following provides a description equivalent to the invention described in the original claims of this application. [1] A cap body having a top plate portion and a cylindrical skirt portion provided on a peripheral portion of the top plate portion; a sealing member provided within the cap body opposite the top plate portion and separate from the cap body; a plurality of locking portions provided in a circumferential direction of the skirt portion, the locking portions protruding radially inwardly from the skirt portion and supporting the sealing member; a plurality of small diameter portions provided between the locking portion and the top plate portion of the skirt portion, the small diameter portions being each provided on the top plate portion side of the locking portion in the axial direction; a plurality of large diameter portions provided adjacent to the small diameter portions in the circumferential direction, the large diameter portions having an inscribed circle diameter larger than the inscribed circle diameters of the plurality of small diameter portions; A cap comprising: [2] The cap described in [1], wherein the inscribed circle diameter of the multiple small diameter portions is smaller than the outer diameter of the sealing member. [3] A cap as described in [1] or [2], which has multiple vent slit portions provided in the circumferential direction of the skirt portion. [4] A molded product having a top plate portion and a skirt portion integrally formed with the top plate portion via annular and curved corner portions is placed on a first tool having a plurality of first protrusions on an outer circumferential surface, a plurality of large diameter portion molding portions adjacent to the first protrusions in the axial direction, and a small diameter portion molding portion adjacent to the large diameter portion molding portions in the circumferential direction; a second tool having a second protrusion disposed between adjacent first protrusions of the first tool and the first tool are rotated relatively to move the second protrusions between adjacent first protrusions, thereby forming a plurality of recesses, a plurality of small diameter portions, and a plurality of large diameter portions in the skirt portion; A method for manufacturing a cap. [5] The method for manufacturing a cap described in [4], further comprising inserting a sealing member into the molded product after the recess and the small diameter portion are molded. [6] The method for manufacturing a cap described in [5], wherein the inscribed circle diameter of the multiple small diameter portions is smaller than the outer diameter of the sealing member. [7] A method for manufacturing a cap described in any one of [4] to [6], wherein the first tool has a plurality of cutter portions that form vent slits in a portion of the recess. [Explanation of symbols]

[0079] 1...cap, 11...cap body, 11A...molded product, 12...sealing member, 12a...flat plate portion, 12b...curved surface portion, 21...top plate portion, 22...skirt portion, 23...corner portion, 31...engagement portion, 31a...upper inclined surface, 31b...lower inclined surface, 32...vent slit portion, 32a...recess, 32b...vent slit, 33...female screw portion, 34...tamper evidence band portion, 34a...fracture portion, 35...upper annular portion, 35a...small diameter portion, 35b...large diameter portion, 41...sliding layer, 41a...first flat plate portion, 41b...first curved surface portion, 41c...projection portion, 42...sealing layer, 42a...second flat plate portion , 42b...second curved portion, 42c...thick portion, 100...can container, 110...mouth portion, 111...jaw portion, 112...male screw portion, 113...curled portion, 200...manufacturing apparatus, 211...first tool, 212...second tool, 213...driving device, 221...first base portion, 221a...hole, 222...first protrusion, 223...cutter portion, 224...small diameter portion molding portion, 225...large diameter portion molding portion, 226...first tamper evidence band portion molding portion, 227...rotating shaft, 231...second base portion, 232...second protrusion, 232A...first tooth, 232B...second tooth, 233...second tamper evidence band portion molding portion.

Claims

1. a cap body having a top plate portion and a cylindrical skirt portion provided on a peripheral edge portion of the top plate portion; a sealing member provided within the cap body opposite the top plate portion and separate from the cap body; a plurality of locking portions provided in a circumferential direction of the skirt portion, the locking portions protruding radially inwardly from the skirt portion and supporting the sealing member; a plurality of small diameter portions provided between the plurality of locking portions of the skirt portion and the top plate portion, the small diameter portions being respectively provided on the top plate portion side of the locking portions in the axial direction; a plurality of large diameter portions provided adjacent to the small diameter portions in the circumferential direction, the large diameter portions having an inscribed circle diameter larger than the inscribed circle diameters of the plurality of small diameter portions; Equipped with The small diameter portion is adjacent to the locking portion and the top plate portion.

2. The cap according to claim 1 , wherein an inscribed circle diameter of the plurality of small diameter portions is smaller than an outer diameter of the sealing member.

3. The cap according to claim 1 or 2, further comprising a plurality of vent slits provided in the circumferential direction of the skirt portion.

4. a molded product having a top plate portion and a skirt portion integrally formed with the top plate portion via annular and curved corner portions is placed on a first tool having a plurality of first protrusions on an outer circumferential surface, a plurality of large diameter portion molding portions adjacent to the first protrusions in the axial direction, and a small diameter portion molding portion provided adjacent to the large diameter portion molding portions in the circumferential direction; a second tool having a second protrusion disposed between adjacent first protrusions of the first tool and the first tool are rotated relatively to move the second protrusions between adjacent first protrusions, thereby forming a plurality of recesses, a plurality of small diameter portions, and a plurality of large diameter portions in the skirt portion; A method for manufacturing a cap.

5. The method for producing a cap according to claim 4, further comprising inserting a sealing member into the molded product after the recess and the small diameter portion are molded.

6. The method for manufacturing a cap according to claim 5 , wherein an inscribed circle diameter of the plurality of small diameter portions is smaller than an outer diameter of the sealing member.

7. The method for manufacturing a cap according to claim 4 , wherein the first tool has a plurality of cutter portions that form a vent slit in a part of the recess.

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