Cap, cap manufacturing device, and cap manufacturing method

Abstract

To provide cap, cap manufacturing device, and cap manufacturing methods that are free of molding defects such as air traps and can enhance aesthetic appearance and strength.SOLUTION: The inner cylindrical portion 11 has an outer diameter R2 that is smaller than the inner diameter R1 of the outer cylindrical portion 10, and the upper end connection portion 12 connects the upper end portion 10a of the outer cylindrical portion 10 to the upper end portion 11a of the inner cylindrical portion 11. The cover portion 13 is provided at a predetermined position P1 below the inner circumferential surface of the inner cylindrical portion 11 from the upper end portion 11a of the inner cylindrical portion 11, and blocks the opening 11b of the inner cylindrical portion 11. The gate mark 15 is provided at a predetermined position P2 below the outer peripheral surface of the outer cylindrical portion 10 from the upper end portion 10a of the outer cylindrical portion 10. The inner connection portion 16 is provided in the lateral and front-rear directions of the cap 1, near the position P3 behind the gate mark 15 on the inner circumferential surface of the outer cylindrical portion 10, and connects a portion of the inner circumferential surface of the outer cylindrical portion 10 with a portion of the outer circumferential surface of the inner cylindrical portion 11 in the vertical direction of the cap 1.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a cap, a cap manufacturing apparatus, and a cap manufacturing method.

Background Art

[0002] Conventionally, a cap, which is a lid for a container, has been manufactured, for example, by injection molding molten resin into a predetermined mold. It is known that this injection molding of the cap greatly affects the aesthetic appearance (e.g., appearance) and strength of the cap depending on the shape of the cap. Therefore, there are various techniques for enhancing the aesthetic appearance of the cap by appropriately designing the shape of the cap.

[0003] For example, Japanese Patent Application Laid-Open No. 2000-108167 (Patent Document 1) discloses a method for manufacturing a resin molded product having an opening hole by injection molding a synthetic resin using a mold. In this method, the mold for molding the resin molded product has a protrusion for providing an opening hole in its cavity, and the cavity around the protrusion surrounding the protrusion has a flow rate changing means for making the flow rate of the injected synthetic resin different on both sides of the protrusion. Further, synthetic resin is injected from a resin injection port into the cavity of the mold and molded. The flow rate changing means is a means for making the cross-sectional areas of the cavity around the protrusion on both sides of the protrusion different. Thereby, it is said that no weld is generated at the meeting portion of the flow of the synthetic resin, and the surface appearance and strength are excellent.

[0004] Furthermore, Japanese Patent Application Laid-Open No. 2008-296980 (Patent Document 2) discloses a hinge cap. This hinge cap is formed by a molding die composed of an upper die part and a lower die part, and includes a pouring cylinder, an engaging cylinder part fitted to the container mouth cylinder part and having an outer cylinder, and an outer peripheral cylinder part continuously provided with a hinge at the upper outer periphery. Also, this hinge cap consists of a connecting piece, a cap body, and an upper lid. The lower ends of the outer cylinder and the outer peripheral cylinder part of the connecting piece are provided on the side opposite to the hinge. The cap body is continuously provided by a plurality of breakable weakening pieces arranged at intervals, and the upper lid is continuously provided via the hinge. An auxiliary flow path is formed in a cylindrical part that forms the outer periphery of the outer cylinder of the engaging cylinder part of the cap body and the inner periphery of the outer peripheral cylinder part of the upper die part. By means of the auxiliary flow path, a flow path piece that extends from the outer peripheral surface of the outer cylinder on the hinge side to the inner peripheral surface of the outer peripheral cylinder part is formed between the outer periphery of the outer cylinder of the cap body and the inner periphery of the outer peripheral cylinder part. Thereby, during molding, even if the flow path for forming the weakening piece that connects the outer cylinder of the engaging cylinder part of the cap body and the lower end of the outer peripheral cylinder part is narrow and blocks the flow of the molten resin, the molten resin flows through the auxiliary flow path and is guided from the engaging cylinder part to the space forming the outer peripheral cylinder part, the hinge, and the upper lid, so it is said that the hydraulic pressure can be stably flowed. Also, although a flow path piece that extends from the outer peripheral surface of the outer cylinder on the hinge side to the inner peripheral surface of the outer peripheral cylinder part is formed between the outer periphery of the outer cylinder of the cap body and the inner periphery of the outer peripheral cylinder part by the auxiliary flow path of the die, since the flow path piece forms a small-diameter connecting part and a large-diameter connecting part, when the die is released, the small-diameter connecting part is broken and the flow path piece is deformed with the large-diameter connecting part as a fulcrum, and it is said that the releasability of the die is not impaired.

[0005] Further, Japanese Patent Application Laid-Open No. 2023-066434 (Patent Document 3) discloses a cap having a cap body to be attached to the mouth of a container. This cap body is integrally formed by molding a main body portion that surrounds the mouth of the container around the axis of the container, a pouring tube provided within the main body portion, and a flow rate adjustment portion provided within the pouring tube. Further, the main body portion has a pouring tube support portion that connects to the outer peripheral surface of the pouring tube and partitions the inside of the main body portion into an outer region and an inner region. Furthermore, the pouring tube has a tubular portion, a bottom end portion, and a pouring outlet. The tubular portion consists of an outer region that extends outward from the container with the pouring tube support portion as a boundary in the axial direction of the cap body and an inner region that extends inward from the container. The bottom end portion forms the inner end surface of the inner region, and the extraction port opens at the bottom end portion. And the flow rate adjustment portion has a plurality of air replacement holes formed around the pouring outlet along the circumference of the cap body's axis within the inner region of the pouring tube, and ribs that divide the apertures of the air replacement holes into a plurality in the circumferential direction of the pouring tube. It is stated that suppressing the number of installed air replacement holes and the opening area can suppress the cause of weld lines generated when the molten resin bypasses the mold portion corresponding to the air replacement holes during injection molding and then merges. Also, by installing ribs that divide the apertures of the air replacement holes into a plurality in the circumferential direction of the pouring tube, during injection molding, the molten resin flows through the cavity of the rib of the mold. As a result, the molten resin that bypasses the mold portion of the air replacement holes flows in opposite directions and merges at the meeting portion. The molten resin that has flowed out of the cavity of the rib flows into the meeting portion, and the meeting portion of the molten resin is pushed out in the flow direction of the molten resin. Therefore, when the molten resin merges at the meeting portion, the meeting angle becomes shallow, the merging of the molten resin becomes smooth, the generation of weld lines is suppressed, and the groove depth of the weld can be reduced.

[0006] Furthermore, Japanese Unexamined Patent Application Publication No. 2023-091100 (Patent Document 4) discloses a hinge cap formed in a main body cavity communicating with a filling gate of a mold. This hinge cap is integrally injection-molded from a cap body, an upper lid portion, a center hinge, and side hinges. The cap body is attached to the mouth portion of the container, and the upper lid portion is formed in the upper lid cavity of the mold and is detachable from the cap body. The center hinge is formed in the center cavity of the mold that forms a flow path communicating the main body cavity and the upper lid cavity, and connects the cap body and the upper lid portion. The side hinges are formed in the side cavities of the mold that form a flow path communicating the main body cavity and the upper lid cavity, and the volume provided on both sides of the center hinge is smaller than the volume of the center hinge. Furthermore, this hinge cap has a speed adjustment portion at the connection site between the cap body and each side hinge. The speed adjustment portion has a recess provided in the cap body, and the flow path cross-sectional area decreases around the mold portion corresponding to the recess during injection molding, forming a flow rate delay structure in which the inflow of the molten resin flowing from the main body cavity to the side cavity is delayed. As a result, the inflow of the molten resin flowing from the main body cavity to the side cavity during injection molding is delayed, and this delay time varies depending on the shape of the recess and can be controlled by adjusting the cross-sectional area of the flow path around the recess, and is adjusted according to the shape and volume of the center hinge and the side hinges. By delaying the inflow speed of the molten resin flowing into the side cavity during injection molding, it is said that the inflow timing of the molten resin flowing through the side cavity reaching the upper lid cavity can be adjusted. Also, by adjusting this inflow timing, it becomes possible to set the inflow timing of the molten resin flowing through the side cavity to be equal to or later than the inflow timing of the molten resin flowing through the center cavity, and it is said that it is possible to suppress the molten resin flowing through the side cavity from reaching the upper lid cavity earlier than the molten resin flowing through the center cavity. As a result, it is possible to avoid the confluence site where the molten resin flowing through the side cavities on both sides merges in the upper lid cavity from being at the base of the center hinge on the upper lid side, and it is possible to avoid the occurrence of a weld line at the base of the center hinge, suppress damage to the center hinge, and obtain a hinge cap with no problem in hinge strength.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0008] In injection molding of a cap, generally, in the structure of the cap, by providing a flow rate adjusting part such as a rib or a protrusion and an auxiliary flow path around a part where the molten resin is difficult to flow, the inflow speed and inflow amount of the molten resin during injection molding are adjusted, and the generation of a weld (or weld line) at the confluence part of the molten resin is prevented to enhance the aesthetic appearance and strength.

[0009] Incidentally, in the injection molding of the cap, the generation of air traps (for example, air pockets) also becomes a problem, similar to the generation of the above-mentioned welds. An air trap refers to a situation where when injecting molten resin from a gate portion at a specific location in the cylindrical portion of the cap, the injected molten resin flows around both sides of the gate portion into the cylindrical portion and converges at a position facing the gate portion. At this time, air does not properly escape to the outside within the flow path into which the molten resin flows, and air accumulates at the convergence point. Such air traps, although depending on the structure of the cap, are said to occur frequently in caps with a complex structure, for example, caps in which an outer cylindrical portion and an inner cylindrical portion are provided doubly, and an upper end connecting portion connects the upper end portion of the outer cylindrical portion and the upper end portion of the inner cylindrical portion (also referred to as a double cap). In such a cap, since the molten resin flowing in from the gate portion flows into each of the outer cylindrical portion and the inner cylindrical portion, differences are likely to occur in the inflow speed and inflow amount of the molten resin flowing into the two cylindrical portions, which causes the generation of air traps.

[0010] Here, in the technology described in Patent Document 1 mentioned above, by providing means for making the cross-sectional areas of the cavities around the protrusion body on both sides of the protrusion body different as a flow rate changing means, the generation of welds is prevented. Also, in the technology described in Patent Document 2 mentioned above, by providing an auxiliary flow path in the cylindrical portion of the hinge cap body, the hydraulic pressure of the molten resin is stabilized. Furthermore, in the technology described in Patent Document 3 mentioned above, by providing ribs that divide the opening of the air replacement hole into a plurality in the circumferential direction of the pouring cylinder, the factors causing the generation of weld lines are suppressed. Also, in the technology described in Patent Document 4 mentioned above, by providing a speed adjustment portion at the connection portion between the cap body and each side hinge in the hinge cap, the generation of a weld line at the root of the center hinge is avoided.

[0011] However, in the technologies described in Patent Documents 1-4 mentioned above, the types of caps are different, and it is unclear whether the generation of air traps can be suppressed when applied to the above-mentioned caps. Also, when the above-mentioned caps are injection molded, a technology that prevents the generation of air traps and has an excellent aesthetic appearance has been demanded.

[0012] Therefore, the present invention has been made to solve the above problems, and even for a cap in which the upper end portion of the outer cylindrical portion and the upper end portion of the inner cylindrical portion are connected by an upper end connection portion, there are no molding defects such as air traps, and it is possible to enhance the aesthetic appearance and strength. An object of the present invention is to provide a cap, a cap manufacturing apparatus, and a cap manufacturing method.

Means for Solving the Problems

[0013] The cap according to the present invention includes an outer cylindrical portion, an inner cylindrical portion, an upper end connection portion, a lid portion, a screw portion, a gate mark, and an inner connection portion. The inner cylindrical portion has an outer diameter smaller than the inner diameter of the outer cylindrical portion. The upper end connection portion connects the upper end portion of the outer cylindrical portion and the upper end portion of the inner cylindrical portion. The lid portion is provided at a predetermined position below the inner peripheral surface of the inner cylindrical portion from the upper end portion of the inner cylindrical portion, and closes the opening of the inner cylindrical portion. The screw portion is provided near the lower end portion of the inner cylindrical portion. The gate mark is provided at a predetermined position below the outer peripheral surface of the outer cylindrical portion from the upper end portion of the outer cylindrical portion. The inner connection portion is provided in the vicinity of the position behind the gate mark on the inner peripheral surface of the outer cylindrical portion in the left-right direction and the front-rear direction of the present cap, and in the vertical direction of the present cap, a part of the inner peripheral surface of the outer cylindrical portion and a part of the outer peripheral surface of the inner cylindrical portion are connected.

[0014] Further, a cap manufacturing apparatus according to the present invention is a cap manufacturing apparatus for manufacturing the cap, and includes a first mold, a second mold, a third mold, a fourth mold, a fifth mold, a gate portion, an inflow control portion, and a take-out control portion. The first mold forms the outer cylindrical portion. The second mold forms the inner cylindrical portion. The third mold forms the upper end connection portion. The fourth mold forms the screw portion. The fifth mold forms the inner connection portion. The gate portion is provided corresponding to the position of the gate mark. The inflow control portion flows the molten resin from the gate portion after assembling the first mold to the fifth mold. The take-out control portion disassembles the first mold to the fifth mold after the inflow of the molten resin and takes out the cap.

[0015] Moreover, the manufacturing method of the cap according to the present invention is a manufacturing method of the manufacturing apparatus of the cap, and includes an inflow control step and a take-out control step. Each control step of the manufacturing method of the cap according to the present invention corresponds to the control unit of the manufacturing method of the cap according to the present invention.

Effect of the Invention

[0016] According to the present invention, even in the case of a cap in which the upper end portion of the outer cylindrical portion and the upper end portion of the inner cylindrical portion are connected by an upper end connection portion, there are no molding defects such as air traps, and it is possible to enhance the aesthetic appearance and strength.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Embodiments for Carrying Out the Invention

[0018] Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described to facilitate understanding of the present invention. It should be noted that the following embodiments are an example of embodying the present invention and do not have the character of limiting the technical scope of the present invention.

[0019] As shown in FIGS. 1-2, the cap 1 according to the present invention includes an outer cylindrical portion 10, an inner cylindrical portion 11, an upper end connecting portion 12, a lid portion 13, a threaded portion 14, a gate mark 15, and an inner connecting portion 16.

[0020] Here, the inner cylindrical portion 11 has an outer diameter R2 smaller than the inner diameter R1 of the outer cylindrical portion 10. Also, the outer cylindrical portion 10 and the inner cylindrical portion 11 are each cylindrical.

[0021] Further, the upper end connection portion 12 connects the upper end portion 10a of the outer cylindrical portion 10 and the upper end portion 11a of the inner cylindrical portion 11. Here, the upper end connection portion 12 is, for example, flat and annular, and the outer cylindrical portion 10, the upper end connection portion 12, and the inner cylindrical portion 11 are configured in a U shape in a cross-sectional view.

[0022] Further, the lid portion 13 is provided at a predetermined position P1 (first position) below the inner peripheral surface of the inner cylindrical portion 11 from the upper end portion 11a of the inner cylindrical portion 11, and closes the opening portion 11b of the inner cylindrical portion 11. Here, the lid portion 13 is, for example, flat and disc-shaped.

[0023] Further, the screw portion 14 is provided near the lower end portion 11c of the inner cylindrical portion 11. Here, the screw portion 14 is provided, for example, on the inner peripheral surface of the inner cylindrical portion 11 from below the lid portion 13 to the lower end portion 11c of the inner cylindrical portion 11.

[0024] Further, the gate trace 15 is provided at a predetermined position P2 below the outer peripheral surface of the outer cylindrical portion 10 from the upper end portion 10a of the outer cylindrical portion 10. Here, the gate trace 15 is provided in a (substantially) circular shape at a predetermined position P2 (second position).

[0025] Further, the inner connection portion 16 is provided near a position P3 (third position) behind the gate trace 15 on the inner peripheral surface of the outer cylindrical portion 10 in the left-right direction and the front-rear direction of the present cap 1, and connects a part of the inner peripheral surface of the outer cylindrical portion 10 and a part of the outer peripheral surface of the inner cylindrical portion 11 in the up-down direction of the present cap 1. Here, the inner connection portion 16 is provided at the third position P3 behind the gate trace 15 in the left-right direction and the front-rear direction of the present cap 1, and connects between the upper end portion 10a of the outer cylindrical portion 10, the upper end portion 11a of the inner cylindrical portion 11, and a position P4 (fourth position) below the second position P2 behind the gate trace 15 in the up-down direction of the present cap 1.

[0026] Thereby, even in the case of a cap in which the upper end portion 10a of the outer cylindrical portion 10 and the upper end portion 11a of the inner cylindrical portion 11 are connected by the upper end connection portion 12, there are no molding defects such as air traps, and it is possible to enhance the aesthetic appearance and strength.

[0027] That is, in the present invention, in the injection molding process, as shown in FIG. 3, when molten resin flows in (is injected) from the gate portion corresponding to the gate mark 15 using a mold corresponding to the cap as described above, the inner connection portion 16 existing at the third position behind the gate mark 15 causes the molten resin to radially spread in the front, rear, left, right, up, and down directions of the outer cylindrical portion 10 and flow evenly into each part such as the outer cylindrical portion 10 and the inner cylindrical portion 11.

[0028] Therefore, as shown in FIG. 4, the speed at which the molten resin flows through the inner connection portion 16 into the screw portion 14 and the lid portion 13, the speed at which the molten resin loops around from the upper end portion 10a of the outer cylindrical portion 10 through the upper end connection portion 12 to the upper end portion 11a of the inner cylindrical portion 11, the speed at which the molten resin loops around both sides of the outer cylindrical portion 10, and the speed at which the molten resin loops around both sides of the inner cylindrical portion 11 are all substantially equal.

[0029] Then, the molten resin will flow into each part of the cap in an orderly manner, and it will be possible to appropriately push out the air existing in each part of the cap to the outside. In particular, before the molten resin flows into the periphery of the upper end portion 10a of the outer cylindrical portion 10, it flows through the inner cylindrical portion 11 into the lid portion 13 and the screw portion 14 and is sequentially filled from each part below the cap 1, thus preventing air from staying. As a result, the molten resin fills the inner cylindrical portion 11, the lid portion 13, and the screw portion 14 first instead of filling the periphery of the upper end portion 10a of the outer cylindrical portion 10 first. Even if the molten resin merges at a predetermined merging region A (including the merging point) of the inner cylindrical portion 11 facing the gate mark 15, after the filling of the lower inner cylindrical portion 11, the lid portion 13, and the screw portion 14 is completed, the periphery of the upper end portion 10a of the outer cylindrical portion 10 located above the merging region A is filled. Therefore, it is possible to prevent the occurrence of an air trap where air accumulates in the merging region.

[0030] Moreover, since it is possible to prevent the generation of air traps and the generation of welds in the molten resin, the aesthetic appearance of the cap can be improved. Furthermore, by preventing the generation of air traps and welds, unevenness and defects in the solidified resin can be prevented, so that the strength of the cap can be increased as a whole.

[0031] Particularly, in a cap in which the upper end portion 10a of the outer cylindrical portion 10 and the upper end portion 11a of the inner cylindrical portion 11 are connected by the upper end connection portion 12, the molten resin first flows into the outer cylindrical portion 10, and then from the upper end portion 10a of the outer cylindrical portion 10 through the upper end connection portion 12 and into the upper end portion 11a of the inner cylindrical portion 11, and then flows into the inner cylindrical portion 11. Therefore, in the above-described cap, a difference is likely to occur between the speed at which the molten resin flows into the outer cylindrical portion 10 and the speed at which the molten resin flows into the inner cylindrical portion 11. Further, since the molten resin flows from the upper end portion 10a of the outer cylindrical portion 10 through the upper end connection portion 12 and into the upper end portion 11a of the inner cylindrical portion 11 and then flows into the inner cylindrical portion 11, the outer cylindrical portion 10 is likely to be filled with the molten resin earlier, while in the inner cylindrical portion 11 and the subsequent screw portion 14 and lid portion 13, the filling of the molten resin is likely to be delayed. Then, the molten resin fills the upper end portion 10a of the outer cylindrical portion 10 first and then fills the inner cylindrical portion 11, the lid portion 13, and the screw portion 14, which causes an air trap at the subsequent confluence point. Due to such differences in the inflow speed of the molten resin and filling delays, air traps and welds are likely to occur.

[0032] Therefore, in the present invention, an inner connection portion 16 that connects the outer cylindrical portion 10 and the inner cylindrical portion 11 is provided near the gate portion corresponding to the gate mark 15. Thereby, before allowing the molten resin to flow into the periphery of the upper end portion 10a of the outer cylindrical portion 10, the molten resin is made to flow into the lid portion 13 and the screw portion 14 through the inner cylindrical portion 11, so that the respective parts below the cap 1 are filled sequentially to prevent an air trap. Along with this, molding defects can be prevented, and the aesthetic appearance and strength can be enhanced.

[0033] Here, the shapes of the outer cylindrical portion 10 and the inner cylindrical portion 11 are not particularly limited. For example, the outer circumference can be a cylindrical shape with a perfect circle, an elliptical cylindrical shape, or a polygonal cylindrical shape. Also, the thicknesses of the outer cylindrical portion 10 and the inner cylindrical portion 11 are not particularly limited. For example, the thicknesses of the outer cylindrical portion 10 and the inner cylindrical portion 11 can be the same, or the thickness of the outer cylindrical portion 10 can be made thicker or thinner than the thickness of the inner cylindrical portion 11.

[0034] Also, the length between the inner diameter R1 of the outer cylindrical portion 10 and the outer diameter R2 of the inner cylindrical portion 11 is not particularly limited. For example, as shown in FIG. 2, it can be within the range of 1 / 10 to 1 / 5 of the inner diameter R1 of the outer cylindrical portion 10.

[0035] Also, the shape of the upper end connection portion 12 is not particularly limited. For example, as shown in FIGS. 1 - 2, it can be flat, or it can be a curved surface or an inverse curved surface with some irregularities. Also, the thickness of the upper end connection portion 12 is not particularly limited. For example, the thickness of the upper end connection portion 12 can be the same as the thickness of the outer cylindrical portion 10 or the inner cylindrical portion 11, or the thickness of the upper end connection portion 12 can be made thicker or thinner than the thickness of the outer cylindrical portion 10 or the inner cylindrical portion 11.

[0036] Also, the shape of the lid portion 13 is not particularly limited. For example, as shown in FIGS. 1 - 2, it can be flat, or it can be a curved surface or an inverse curved surface with some irregularities. Also, the thickness of the lid portion 13 is not particularly limited. For example, it can be the same as the thickness of the inner cylindrical portion 11, or it can be made thicker or thinner than the thickness of the inner cylindrical portion 11.

[0037] Also, the shape of the lid portion 13 can be provided with a needle portion 17 protruding upward, for example, as shown in FIG. 5. This needle portion 17 is used, for example, when placed in a container having an opening for attaching the cap 1 and the opening is covered with a predetermined sealing member, to press the needle portion 17 of the cap 1 against the sealing member to break the sealing member and open the opening. In this way, by providing the needle portion 17, the functionality of the cap 1 can be enhanced.

[0038] Here, there is no particular limitation on the outer diameter of the needle portion 17. For example, as shown in FIG. 5, the outer diameter R3 of the needle portion 17 is configured to be smaller than the outer diameter R4 of the lid portion 13, and can be, for example, within the range of 1 / 5 to 4 / 5 of the outer diameter R4 of the lid portion 13. In FIG. 5, the outer diameter R3 of the needle portion 17 is approximately 1 / 2 of the outer diameter R4 of the lid portion 13.

[0039] Also, there is no particular limitation on the configuration of the needle portion 17. For example, as shown in FIG. 5, by protruding from below the lid portion 13, a configuration with a hollow interior may be used, or by connecting a conical shape above the lid portion 13, a configuration with a filled interior may also be acceptable. As shown in FIG. 5, the needle portion 17 has a configuration in which the lower surface of a cone is connected to the upper surface of a cylinder, but it is not limited to this. For example, it may be a cone, a triangular pyramid, or a polygonal pyramid. Also, there is no particular limitation on the thickness of the needle portion 17. For example, in the case where the needle portion 17 protrudes from below the lid portion 13, the thickness of the needle portion 17 may be the same as the thickness of the lid portion 13, or may be thicker or thinner than the thickness of the lid portion 13.

[0040] Also, there is no particular limitation on the configuration of the threaded portion 14. For example, as shown in FIGS. 1 - 5, a male-thread configuration protruding from the inner peripheral surface of the inner cylindrical portion 11 may be used, or a female-thread configuration recessed from the inner peripheral surface of the inner cylindrical portion 11 may also be acceptable.

[0041] Also, there is no particular limitation on the shape of the gate mark 15. For example, as shown in FIGS. 1 - 5, it may be circular, or other shapes such as an elliptical shape or a polygonal shape, as long as it is a shape that can be recognized as the gate mark 15, there is no particular limitation.

[0042] Furthermore, although there is no particular limitation on the thickness of the inner connection portion 16, for example, as shown in FIG. 2, the thickness of the inner connection portion 16 may be the same as the thickness of the outer cylindrical portion 10 or the inner cylindrical portion 11, or may be thinner than the thickness of the outer cylindrical portion 10 or the inner cylindrical portion 11. Also, since the inner connection portion 16 is also a location where the molten resin flowing in from the gate portion G of the gate trace 15 passes through, as shown in FIG. 6, it is preferable that the thickness t1 of the inner connection portion 16 is configured to be the same as or thinner than the thickness t2 of the outer cylindrical portion 10 or the thickness t3 of the inner cylindrical portion 11. For example, the thickness t1 of the inner cylindrical portion 11 can be within the range of 2 / 3 to 1 of the thickness t2 of the outer cylindrical portion 10 or the thickness t3 of the inner cylindrical portion 11. Incidentally, in FIG. 6, the thickness t1 of the inner connection portion 16 is the same as the thickness t2 of the outer cylindrical portion 10.

[0043] Moreover, there is no particular limitation on the configuration of the inner connection portion 16. For example, as shown in FIG. 2, in the vertical direction of this cap 1, the upper end portion 10a of the outer cylindrical portion 10, the upper end portion 11a of the inner cylindrical portion 11, and the fourth position P4 may be connected. Alternatively, as shown in FIG. 6, the fourth position P4 may be adjusted between the second position P2 of the gate trace 15 and the lower end portion 11c of the inner cylindrical portion 11. For example, as shown in FIG. 6, the fourth position P4 may be below the second position P2 of the gate trace 15 in the vertical direction of this cap 1. For example, the height h1 from the second position P2 of the gate trace 15 to the fourth position P4 may be set to be the same as or lower than the height h2 from the second position P2 of the gate trace 15 to a predetermined position P5 (fifth position) of the lower end portion 11c of the inner cylindrical portion 11.

[0044] In addition, there is no particular limitation on the shape of the inner connection portion 16. For example, as shown in FIG. 2, it may be a rectangle that is long in the vertical direction, or a trapezoid with a tapered surface provided on the side surface that widens downward so that the lower surface is wider than the upper surface. By providing the tapered surface, demolding can be facilitated. Here, there is no particular limitation on the angle of the tapered surface, and it is preferably within the range of 0.1 degrees to 0.5 degrees with respect to the vertical direction.

[0045] Furthermore, although there is no particular limitation on the number of the inner connection portions 16, for example, as shown in FIG. 2, only one inner connection portion 16 may be provided at a third position P3 behind the gate trace 15 on the inner circumferential surface of the outer cylindrical portion 10, and the number of the inner connection portions 16 may be one. Alternatively, as shown in FIG. 7A, the inner connection portions 16 may be provided at the third position P3 and at a position P6 (sixth position) facing the third position P3 with respect to the center C of the cap 1 on the inner circumferential surface of the outer cylindrical portion 10, respectively, and the number of the inner connection portions 16 may be two. Thereby, the connection points between the outer cylindrical portion 10 and the inner cylindrical portion 11 can be increased, the inflow rate of the molten resin can be made more uniform, and the occurrence of molding defects can be further suppressed. Also, in terms of the aesthetic appearance, the arrangement of the inner connection portions 16 confirmed in the bottom view forms a kind of pattern, enhancing the decorativeness and making the cap 1 visually harmonious. Note that in the bottom view, the inner connection portions 16 are confirmed as protruding ribs-like ornaments.

[0046] Alternatively, as shown in FIG. 7B, the inner connection portions 16 may be provided at the third position P3, the sixth position P6, a position P7 (seventh position) at 60 degrees, a position P8 (eighth position) at 120 degrees, a position P9 (ninth position) at 240 degrees, and a position P10 (tenth position) at 300 degrees with respect to the third position P3 and the center C of the cap 1 on the inner circumferential surface of the outer cylindrical portion 10, respectively, and the number of the inner connection portions 16 may be six. That is, the inner connection portions 16 may be provided at the third position P3 and may be provided radially with respect to the center C of the cap 1.

[0047] Furthermore, there is no particular limitation on the installation position of the inner connection portions 16. For example, as shown in FIG. 2, the inner connection portions 16 may be provided at the third position P3 or may be provided near the third position P3 in the left-right direction and the front-rear direction of the cap 1. For example, as shown in FIG. 7C, the inner connection portions 16 may be provided at a position P11 (eleventh position) which is the intersection of an inclined line L2 inclined at a predetermined angle α with respect to a connection line L1 between the third position P3 and the center C of the cap 1 and the inner circumferential surface of the outer cylindrical portion 10. The angle α between the connection line L1 and the inclined line L2 is preferably in the range of, for example, 0.1 degrees to 15.0 degrees, and more preferably in the range of 0.1 degrees to 10.0 degrees.

[0048] Also, along with the change in the installation position of the inner connection portion 16, the installation positions of the other inner connection portions 16 may be changed. For example, as shown in FIG. 7D, the inner connection portion 16 is provided at the eleventh position P11 of the intersection of the inclined line L2 and the inner peripheral surface of the outer cylindrical portion 10. Next, the other inner connection portions 16 are provided at the position P12 (the twelfth position) that is 90 degrees with respect to the eleventh position P11 and the center C of the cap 1, the position P13 (the thirteenth position) that is 180 degrees, and the position P14 (the fourteenth position) that is 270 degrees, respectively. The number of the inner connection portions 16 may be four. Thus, the configuration and installation position of the inner connection portion 16 can be appropriately changed in design.

[0049] Also, in the present invention, as shown in FIGS. 1-2, a locking portion 18 protruding outward may be provided on the outer peripheral surface of the inner cylindrical portion 11 of the cap 1. Thereby, when the mouth portion is attached between the outer cylindrical portion 10 and the inner cylindrical portion 11, the locking portion 18 locks to the mouth portion, so that the cap 1 can be gripped with a predetermined strength on the mouth portion.

[0050] By the way, the present invention can provide a manufacturing apparatus 100 for the cap 1. The manufacturing apparatus 100 for the cap 1 will be described. As shown in FIG. 8, it includes a first mold K1, a second mold K2, a third mold K3, a fourth mold K4, a fifth mold K5, a gate portion G, an inflow control portion 101, and a take-out control portion 102.

[0051] Here, the first mold K1 forms the outer cylindrical portion 10, and the second mold K2 forms the inner cylindrical portion 11. The first mold K1 constitutes a cavity (concave portion), and the second mold K2 constitutes a core (convex portion). There is no particular limitation on the configuration of the first mold K1 and the second mold K2. For example, as shown in FIG. 8, the first mold K1 forms the outer cylindrical portion 10 from the outer peripheral surface, and the second mold K2 is mounted between the outer cylindrical portion 10 and the inner cylindrical portion 11 to form the inner peripheral surface of the outer cylindrical portion 10 and the outer peripheral surface of the inner cylindrical portion 11.

[0052] Further, the third mold K3 forms an upper end connection portion 12 and a lid portion 13, and the fourth mold K4 forms a screw portion 13. The third mold K3 constitutes a cavity insert, and the fourth mold K4 constitutes a screw core. Here, the configurations of the third mold K3 and the fourth mold K4 are not particularly limited. For example, as shown in FIG. 8, the third mold K3 forms from the upper surface of the upper end connection portion 12 to the inner peripheral surface of the inner cylindrical portion 11 and the upper surface of the lid portion 13, and the fourth mold K4 abuts from below the inner peripheral surface of the inner cylindrical portion 11 to form the lower surface of the lid portion 13 and the screw portion 13.

[0053] Further, the fifth mold K5 forms an inner connection portion 16, and the gate portion G is provided corresponding to the third position P3 of the gate trace 15. Here, for example, as shown in FIG. 8, the fifth mold K5 is configured as a part of the second mold K2, and is provided as a rectangular slit between the outer cylindrical portion 10 and the inner cylindrical portion 11 corresponding to the gate portion G (the position P3 behind the gate trace 15), and forms a part of the inner peripheral surface of the outer cylindrical portion 10, a part of the outer peripheral surface of the inner cylindrical portion 11, and the lower surface of the inner connection portion 16.

[0054] Here, since the second mold K2 is provided in a cylindrical shape and the fifth mold K5 is provided as a slit obtained by cutting out a part of the cylindrical portion of the second mold K2, the mold release of the second mold K2 can be made smooth. Further, the gate portion G is provided in the first mold K1 facing the fifth mold K5 corresponding to the third position P3 of the gate trace 15.

[0055] Further, a stripper S for pressing the cap 1 serving as a workpiece may be provided between the lower portion of the first mold K1 and the lower portions of the second mold K2 and the fifth mold K5. As will be described later, the stripper S has a role of removing the manufactured cap 1 from the second mold K2 and the fifth mold K5.

[0056] And after assembling the first mold K1 to the fifth mold K5, the inflow control unit 101 allows the molten resin to flow in from the gate part G. Here, for example, as shown in FIG. 8, the inflow control unit 101 installs the first mold K1, the second mold K2, the third mold K3, the fourth mold K4, and the fifth mold K5 to complete the assembly of the molds.

[0057] Note that the order of assembling the molds is not particularly limited. For example, the inflow control unit 101 may move the fourth mold K4 upward and then install the first mold K1, the second mold K2, the third mold K3, and the fifth mold K5.

[0058] Then, the inflow control unit 101 injects the preheated molten resin from the gate part G to pour the molten resin into each part of the cap 1. As a result, since the inner connection part 16 is provided near the gate part G as described above, it becomes possible to evenly fill each part of the cap 1 with the molten resin, without molding defects such as air traps, and it is possible to enhance the aesthetic appearance and strength.

[0059] Also, after the molten resin has flowed in, the ejection control unit 102 disassembles (ejects the mold) the first mold K1 to the fifth mold K5 to take out the cap 1. Here, for example, as shown in FIG. 9, the ejection control unit 102 first separates the third mold K3 and then separates the first mold K1. Here, the ejection control unit 102 may separate the third mold K3 and the first mold K1 together. Next, as shown in FIG. 10, the ejection control unit 102 separates the fourth mold K4 while rotating it and separates the second mold K2 and the fifth mold K5 downward. Here, since the stripper S holds the cap 1 after manufacturing, it is possible to smoothly separate the fourth mold K4, the second mold K2, and the fifth mold K5. Thereby, the disassembly of the mold is completed.

[0060] Here, there are no particular limitations on the method of separating the second mold K2 and the fifth mold K5. For example, the ejection control unit 102 may separate the cap 1 and the stripper S from the second mold K2 and the fifth mold K5 by moving the stripper S upward.

[0061] In addition, there are no particular limitations on the order of disassembling the molds. For example, the ejection control unit 102 may separate the fourth mold K4, then separate the second mold K2 and the fifth mold K5, and then separate and disassemble the third mold K3 and the first mold K1. As a result, since no air trap occurs, the cap 1 with excellent aesthetic appearance and strength can be manufactured.

[0062] Furthermore, the present invention can provide a manufacturing method for the cap 1. The manufacturing method of the cap 1 will be described. It is a manufacturing method of a manufacturing apparatus 100 including a first mold K1, a second mold K2, a third mold K3, a fourth mold K4, a fifth mold K5, and a gate portion G, and includes an inflow control step and an ejection control step. The inflow control step is to flow the molten resin from the gate portion G after assembling the first mold K1 to the fifth mold K5. The ejection control step is to disassemble the first mold K1 to the fifth mold K5 and take out the cap 1 after the molten resin has flowed in. Even with such a configuration, there are no molding defects such as air traps, and it is possible to enhance the aesthetic appearance and strength.

[0063] Now, the effects of the cap 1 according to the present invention will be described. In order to confirm the effects of the present invention, simulation software for a predetermined molten resin was used. In this simulation software, a cap having a predetermined shape is created, a predetermined gate portion G is set for the cap, and by flowing the molten resin from that, the inflow rate, inflow amount, and filling condition of the molten resin can be confirmed at predetermined time intervals.

[0064] Here, as Comparative Example 1, based on FIGS. 1-2, a cap without an inner connection portion 16 was adopted. In this cap, an outer cylindrical portion 10, an inner cylindrical portion 11, an upper end connection portion 12, a lid portion 13, and a screw portion 14 are provided, and an upper end portion 10a of the outer cylindrical portion 10 and an upper end portion 11a of the inner cylindrical portion 11 are connected by the upper end connection portion 12 to form a cap (for example, a double cap). The gate portion G corresponds to the gate trace 15.

[0065] On the other hand, as Example 1, based on FIGS. 1-2, a cap 1 with only one inner connection portion 16 was configured. In this Example 1, an outer cylindrical portion 10, an inner cylindrical portion 11, an upper end connection portion 12, a lid portion 13, a screw portion 14, and an inner connection portion 16 are provided. The configurations of the outer cylindrical portion 10, the inner cylindrical portion 11, and the upper end connection portion 12 in Example 1 are the same as those in Comparative Example 1. Here, the thickness of the inner connection portion 16 is configured to be thinner than the thickness of the outer cylindrical portion 10 or the inner cylindrical portion 11. The installation position of the inner connection portion 16 is set as a third position P3 in the left-right direction and the front-back direction of this cap 1. The configuration of the inner connection portion 16 is to connect between the upper end portion 10a of the outer cylindrical portion 10, the upper end portion 11a of the inner cylindrical portion 11, and a fourth position P4 in the up-down direction of this cap 1.

[0066] Now, the simulation software was started, and molten resin was made to flow into each of Comparative Example 1 and Example 1 to confirm the inflow rate, inflow amount, and filling condition of the molten resin. Here, taking the time required from the start of inflow to the completion of inflow of the molten resin as 10, the state from 10% filling to 100% filling was observed.

[0067] As a result, as shown in FIG. 11, at 20% filling, the filling conditions of the molten resin were almost the same in both Comparative Example 1 and Example 1. However, in Comparative Example 1, at 80% filling and 90% filling, a difference was seen in the inflow rate of the molten resin in the outer cylindrical portion 10 and the inflow rate of the molten resin in the inner cylindrical portion 11. Before the molten resin flowed into the lid portion 13 and the screw portion 14 through the inner cylindrical portion 11, it flowed into the periphery of the upper end portion 10a of the outer cylindrical portion 10 located above the confluence region A, causing air to stagnate inside and generating a portion that seems to be an air trap T.

[0068] On the one hand, in Example 1, even when the filling is 80% or 90%, the inflow rate of the molten resin in the outer cylindrical portion 10 is equal to the inflow rate of the molten resin in the inner cylindrical portion 11. Before the molten resin flows into the periphery of the upper end portion 10a of the outer cylindrical portion 10 located above the confluence region A, it flows into the lid portion 13 and the screw portion 14 through the inner cylindrical portion 11, and is sequentially filled from each part below the cap 1, and no air trap T portion was generated. Therefore, it was found that in Example 1, the generation of the air trap T can be prevented. Incidentally, a photograph of the cap in which the air trap T is generated and a cavity is formed at 90% filling in Comparative Example 1 of FIG. 9 is shown for reference.

[0069] Next, the needle portion 17 provided on the upper surface of the lid portion 13 was examined. As Example 2, in the same configuration as Example 1, another inner connection portion 16 was provided at a position (the sixth position P6) facing the installation position (the third position P3) of the inner connection portion 16, and an elongated needle portion 17 was provided on the lid portion 13. The outer diameter R3 of the needle portion 17 in Example 2 is 1 / 5 of the outer diameter R4 of the lid portion 13.

[0070] Also, as Example 3, a cap was configured in the same configuration as Example 1, with another inner connection portion 16 provided at a position (the sixth position P6) facing the installation position (the third position P3) of the inner connection portion 16, and a thick needle portion 17 provided on the lid portion 13. The outer diameter R3 of the needle portion 17 in Example 3 is 4 / 5 of the outer diameter R4 of the lid portion 13. Then, in the same manner as described above, the simulation software was started, and the molten resin was made to flow into each of Example 2 and Example 3, and the inflow rate, inflow amount, and filling condition of the molten resin were confirmed.

[0071] As a result, as shown in FIG. 12, in both Example 2 and Example 3, at 80% filling and 90% filling, in the same manner as described above, before the molten resin flows into the periphery of the upper end portion 10a of the outer cylindrical portion 10 located above the confluence region A, it flows into the lid portion 13 and the screw portion 14 through the inner cylindrical portion 11, and no air trap T portion was generated. Therefore, it was found that in both Example 2 and Example 3, the generation of the air trap T can be prevented.

[0072] Next, the shape of the needle portion 17 and the number of inner connection portions 16 were examined. As Example 4, to the same configuration as Example 1, another inner connection portion 16 was provided at a position facing the installation position (third position P3) of the inner connection portion 16 (sixth position P6), and a medium-sized needle portion 17 was provided on the lid portion 13. The outer diameter R3 of the needle portion 17 of Example 4 is 1 / 2 of the outer diameter R4 of the lid portion 13.

[0073] Also, as Example 5, to the same configuration as Example 4, inner connection portions 16 were provided at positions P7 (seventh position) at 60 degrees, position P8 (eighth position) at 120 degrees, position P9 (ninth position) at 240 degrees, and position P10 (tenth position) at 300 degrees with respect to the installation position (third position P3) of the inner connection portion 16 and the center C of the cap 1, and the number of inner connection portions 16 was six. Then, in the same manner as described above, the simulation software was started, and the molten resin was caused to flow into each of Example 4 and Example 5, and the flow rate, inflow amount, and filling condition of the molten resin were confirmed.

[0074] As a result, as shown in FIG. 13, in both Example 4 and Example 5, at 80% filling and 90% filling, as described above, before the molten resin flows into the periphery of the upper end portion 10a of the outer cylindrical portion 10 located above the confluence region A, it flows into the lid portion 13 and the screw portion 14 through the inner cylindrical portion 11, and no air trap T portion was generated. Therefore, it was found that the generation of the air trap T can be prevented in both Example 4 and Example 5.

[0075] Next, the installation position of the inner connection portion 16 was examined. As Example 6, to the same configuration as Example 1, a medium-sized needle portion 17 was provided on the lid portion 13, and regarding the installation position of the inner connection portion 16, the angle α between the connection line L1 and the inclined line L2 was changed to 5.0 degrees. Also, as Example 7, to the same configuration as Example 6, regarding the installation position of the inner connection portion 16, the angle α between the connection line L1 and the inclined line L2 was changed to 10.0 degrees. Then, in the same manner as described above, the simulation software was started, and the molten resin was caused to flow into each of Example 6 and Example 7, and the flow rate, inflow amount, and filling condition of the molten resin were confirmed.

[0076] As a result, as shown in Fig. 14, in both Example 6 and Example 7, when the filling rate is 80% or 90%, similar to the above, before the molten resin flows into the periphery of the upper end portion 10a of the outer cylindrical portion 10 located above the confluence region A, it flows into the lid portion 13 and the screw portion 14 through the inner cylindrical portion 11, and no air trap T is generated. Therefore, it was found that the generation of the air trap T can be prevented in both Example 6 and Example 7.

Industrial Applicability

[0077] As described above, the cap, the cap manufacturing apparatus, and the cap manufacturing method according to the present invention are useful for caps, cap manufacturing apparatuses, and cap manufacturing methods for accommodating liquid contents such as food seasonings, drugs, cosmetics, shampoos, rinses, and liquid soaps. Even for a cap in which the upper end portion of the outer cylindrical portion and the upper end portion of the inner cylindrical portion are connected by an upper end connection portion, it is effective as a cap, a cap manufacturing apparatus, and a cap manufacturing method that have no molding defects such as air traps and can enhance the aesthetic appearance and strength.

Explanation of Reference Numerals

[0078] 1 Cap 10 Outer cylindrical portion 11 Inner cylindrical portion 12 Upper end connection portion 13 Lid portion 14 Screw portion 15 Gate mark 16 Inner connection portion

Claims

1. An outer cylindrical portion, an inner cylindrical portion having an outer diameter smaller than the inner diameter of the outer cylindrical portion, an upper connecting portion connecting the upper end portion of the outer cylindrical portion and the upper end portion of the inner cylindrical portion, a lid portion provided at a predetermined position below the inner peripheral surface of the inner cylindrical portion from the upper end portion of the inner cylindrical portion to close the opening of the inner cylindrical portion, a threaded portion provided near the lower end portion of the inner cylindrical portion, a gate trace provided at a predetermined position below the outer peripheral surface of the outer cylindrical portion from the upper end portion of the outer cylindrical portion, an inner connecting portion provided in the vicinity of a position behind the gate trace on the inner peripheral surface of the outer cylindrical portion in the left - right direction and the front - rear direction of the present cap, and connecting a part of the inner peripheral surface of the outer cylindrical portion and a part of the outer peripheral surface of the inner cylindrical portion in the up - down direction of the present cap, A cap comprising the above.

2. The inner connecting portion connects, in the up - down direction of the present cap, between the upper end portion of the outer cylindrical portion, the upper end portion of the inner cylindrical portion, and a position below the position behind the gate trace. The cap according to Claim 1.

3. An outer cylindrical portion, an inner cylindrical portion having an outer diameter smaller than the inner diameter of the outer cylindrical portion, an upper connecting portion connecting the upper end portion of the outer cylindrical portion and the upper end portion of the inner cylindrical portion, a lid portion provided at a predetermined position below the inner peripheral surface of the inner cylindrical portion from the upper end portion of the inner cylindrical portion to close the opening of the inner cylindrical portion, a threaded portion provided near the lower end portion of the inner cylindrical portion, a gate trace provided at a predetermined position below the outer peripheral surface of the outer cylindrical portion from the upper end portion of the outer cylindrical portion, an inner connecting portion provided in the vicinity of a position behind the gate trace on the inner peripheral surface of the outer cylindrical portion in the left - right direction and the front - rear direction of the present cap, and connecting a part of the inner peripheral surface of the outer cylindrical portion and a part of the outer peripheral surface of the inner cylindrical portion in the up - down direction of the present cap, A cap manufacturing apparatus for manufacturing a cap comprising the above, a first mold for forming the outer cylindrical portion, a second mold for forming the inner cylindrical portion, a third mold for forming the upper connecting portion, a fourth mold for forming the threaded portion, a fifth mold for forming the inner connecting portion, a gate portion provided corresponding to the position of the gate trace, an inflow control portion for flowing molten resin from the gate portion after assembling the first mold to the fifth mold, a take - out control portion for disassembling the first mold to the fifth mold after the inflow of the molten resin and taking out the cap, A cap manufacturing apparatus comprising the above.

4. an outer cylindrical portion, an inner cylindrical portion having an outer diameter smaller than the inner diameter of the outer cylindrical portion, an upper connecting portion connecting the upper end portion of the outer cylindrical portion and the upper end portion of the inner cylindrical portion, a lid portion provided at a predetermined position below the inner peripheral surface of the inner cylindrical portion from the upper end portion of the inner cylindrical portion to close the opening of the inner cylindrical portion, a threaded portion provided near the lower end portion of the inner cylindrical portion, a gate trace provided at a predetermined position below the outer peripheral surface of the outer cylindrical portion from the upper end portion of the outer cylindrical portion, an inner connecting portion provided in the vicinity of a position behind the gate trace in the inner peripheral surface of the outer cylindrical portion in the left - right direction and the front - rear direction of the present cap, and connecting a part of the inner peripheral surface of the outer cylindrical portion and a part of the outer peripheral surface of the inner cylindrical portion in the up - down direction of the present cap, A manufacturing method of a manufacturing apparatus for a cap comprising: The manufacturing apparatus includes: a first mold for forming the outer cylindrical portion, a second mold for forming the inner cylindrical portion, a third mold for forming the upper connecting portion, a fourth mold for forming the threaded portion, a fifth mold for forming the inner connecting portion, a gate portion provided corresponding to the position of the gate trace, and comprises The manufacturing method includes: an inflow control step of flowing molten resin from the gate portion after assembling the first mold to the fifth mold, a take - out control step of disassembling the first mold to the fifth mold after the inflow of the molten resin and taking out the cap, A manufacturing method of a cap comprising the above steps.

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