JP7803764B2 - Cap unit, manufacturing method thereof, and capped container - Google Patents

Description

The present invention relates to a cap unit, a method for manufacturing the same, and a capped container.

Conventionally, there have been capped containers equipped with a cap unit (stopper) that is removably attached to the neck of a container body that has an open top, thereby closing the top opening of the container body (see, for example, Patent Document 1 below).

Such a cap unit has a cap body that closes the top opening of the container body, and is structured so that the cap body is attached to the container body by screwing. The cap unit also has a waterproof gasket that is detachably attached to the cap body, and this waterproof gasket seals (watertightly seals) the space between the container body and the cap body.

The waterproof gasket is made of a ring-shaped elastic member and is attached by fitting to the outer periphery of the lower end of the inside plug, which is fitted inside the container body of the cap body. When the cap body is screwed onto the container body, the waterproof gasket abuts against the protruding portion that protrudes all around from the inside of the container body, causing it to elastically deform and come into close contact with the protruding portion all around. This makes it possible to seal (watertightly seal) the gap between the container body and the cap body.

Japanese Patent Application Laid-Open No. 2021-187058

In some of the cap units mentioned above, the waterproof gasket is formed integrally with the inner plug of the cap body by insert molding. Specifically, a mold is used to form a cavity space between the inner plug and the waterproof gasket, and the material for the waterproof gasket is sealed into this cavity, forming the waterproof gasket integrally with the cap body.

In this case, using a mold that is divided in the axial direction of the cap body, rather than using a mold that is divided in a direction perpendicular to the axial direction of the cap body, makes it possible to increase the number of cap units (yield) produced in a single molding run, due to the mold structure and the shape of the inner plug of the cap body that is inserted.

On the other hand, when using a mold that is divided in the axial direction of the cap body, the inner plug of the cap body placed inside the mold must be firmly pressed down by the mold in the axial direction to prevent flash from forming. In this case, the inner plug of the cap body is generally made of a resin material, and the mold generally presses down the inner plug from the opposite direction to prevent it from deforming due to the pressure and heat generated when the mold is closed. Furthermore, even if it is pressed down from the opposite direction, if the ends of two axially elongated parts are pressed together, it is susceptible to dimensional variations, and the inner plug is likely to deform due to the pressure generated when the mold is closed.

For this reason, by making the outer diameter of the inner plug of the cap body larger than the outer diameter of the watertight gasket, a portion (pressing allowance) is secured on the outside of the watertight gasket, which is molded integrally with the inner plug, to press the inner plug in the axial direction (see, for example, Figure 3C of Patent Document 1).

However, when the majority of the overall height of the inner stopper is fitted into the inside of the container body from the top opening of the container body, the outer diameter of the watertight gasket is smaller than the outer diameter of the inner stopper of the cap body, which means that the inner diameter of the protruding portion of the container body that abuts against the watertight gasket to seal off water is also small. This results in a large difference between the inner diameter of the top opening of the container body and the inner diameter of the protruding portion, and in order to ensure an appropriate inner diameter of the protruding portion, the diameter of the top opening of the container body or the outer diameter of the container body must be large, which means the container body itself becomes larger.

The present invention was proposed in light of these conventional circumstances, and aims to provide a suitable cap unit in which a waterproof gasket is integrally formed with the cap body, a method for manufacturing the same, and a capped container equipped with such a cap unit.

In order to achieve the above object, the present invention provides the following means.
[1] A cap unit that can be detachably attached to a container body having an open top,
a cap body that closes the upper opening of the container body when fitted into the container body from the upper opening,
The cap body includes an inside plug that is fitted into the container body from an upper opening of the container body;
a waterproof packing that is integrally formed on the outer periphery of the lower end of the inside plug and seals the gap between the container body and the inside plug;
The cap unit is characterized in that the inner plug has a boundary surface facing the upper surface of the watertight gasket, an inclined surface that slopes upward from outside the watertight gasket on the boundary surface, and an outer peripheral surface that rises upward from outside the inclined surface.
[2] The cap unit according to [1], wherein the inclined surface is linearly inclined in a cross section along the axial direction of the inside plug.
[3] The cap unit according to [1], wherein the inclined surface is inclined in a curved shape in a cross section along the axial direction of the inside plug.
[4] The cap unit described in [1], characterized in that the inner plug has a first recess shaped to correspond to a first convex portion protruding inward from the upper end of the inner periphery of the watertight gasket, and a second recess shaped to correspond to a second convex portion protruding upward from the lower end of the inner periphery of the watertight gasket.
[5] The cap unit described in [4], characterized in that the inner plug has a third convex portion located between the first concave portion and the second concave portion and having a shape corresponding to the third concave portion formed between the first convex portion and the second convex portion of the water-stopping gasket.
[6] A cap unit described in any one of [1] to [5], characterized in that the outer end of the boundary surface is located outside the outer upper end of the waterproof gasket.
[7] The cap unit according to any one of [1] to [6], wherein the bottom surface of the inside plug is flush with the bottom surface of the watertight packing.
[8] A method for manufacturing the cap unit according to any one of [1] to [7],
When the watertight gasket is integrally formed with the cap body using a mold that forms a cavity space corresponding to the shape of the watertight gasket between the inside plug and the mold,
A method for manufacturing a cap unit, comprising forming the cavity space between the mold and the inside plug while the mold is in contact with the inclined surface.
[9] The method for manufacturing the cap unit according to [8], characterized in that a mold that is divided in the axial direction of the cap body is used.
[10] The method for manufacturing the cap unit according to [8] or [9], wherein the waterproof packing is molded from liquid silicone.
[11] The cap unit according to any one of [1] to [7] above;
A capped container comprising: a container body to which the cap unit is attached.
[12] The capped container according to [11], wherein the container body has a vacuum insulation structure.

As described above, the present invention makes it possible to provide a suitable cap unit in which a waterproof gasket is integrally formed with the cap body, a method for manufacturing the same, and a capped container equipped with such a cap unit.

1 is a perspective view showing the appearance of a capped container equipped with a cap unit according to one embodiment of the present invention; 2 is a cross-sectional view showing the configuration of a capped container equipped with the cap unit shown in FIG. 1. FIG. FIG. 2 is a cross-sectional perspective view showing the configuration of the cap unit shown in FIG. 1 . FIG. 2 is a bottom view showing the configuration of the cap unit shown in FIG. 1 . 2A is a perspective view of an outer lid provided in the cap unit shown in Fig. 1, as seen from above, and FIG. 2B is a perspective view of an outer lid provided in the cap unit shown in Fig. 1, as seen from below. 2A and 2B are perspective views of the inside plug of the cap unit shown in Fig. 1, as viewed from above and below, respectively; 2 is a cross-sectional view showing a state before an inside plug is attached to the outer lid of the cap unit shown in FIG. 1 . 4 is a cross-sectional view illustrating a state in which an inside plug is attached to the outer lid of the cap unit shown in FIG. 1 . FIG. 4 is a cross-sectional view illustrating a state in which an inside plug is attached to the outer lid of the cap unit shown in FIG. 1 . FIG. 2 is an enlarged cross-sectional view of a main part of an inside plug and a watertight gasket provided in the cap unit shown in FIG. 1 . 10 is a cross-sectional view illustrating a state in which a watertight gasket is integrally formed with an inside plug using a mold. FIG. FIG. 12 is an enlarged cross-sectional view of a main part shown in FIG. 11 . 11 is a cross-sectional view showing another shape of the inclined surface shown in FIG. 10.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(Cap unit and capped container)
First, as one embodiment of the present invention, a capped container 100 including a cap unit 1 shown in, for example, FIGS. 1 to 10 will be described.

1 is a perspective view showing the appearance of a capped container 100 equipped with a cap unit 1. FIG. 2 is a cross-sectional view showing the configuration of a capped container 100 equipped with a cap unit 1. FIG. 3 is a cross-sectional perspective view showing the configuration of the cap unit 1. FIG. 4 is a bottom view showing the configuration of the cap unit 1. FIG. 5(A) is a perspective view of the outer lid 9 equipped with the cap unit 1 shown in FIG. 1, seen from above. FIG. 5(B) is a perspective view of the outer lid 9 equipped with the cap unit 1 shown in FIG. 1, seen from below. FIG. 6(A) is a perspective view of the inside stopper 10 equipped with the cap unit 1 shown in FIG. 1, seen from above. FIG. 6(B) is a perspective view of the inside stopper 10 equipped with the cap unit 1 shown in FIG. 1, seen from below. FIG. 7 is a cross-sectional view showing the state before the inside stopper 10 is attached to the outer lid 9 of the cap unit 1. FIG. 8 is a cross-sectional view illustrating the state of attaching the inside stopper 10 to the outer lid 9 of the cap unit 1. FIG. 9 is a cross-sectional view illustrating the state of attaching the inside stopper 10 to the outer lid 9 of the cap unit 1. Figure 10 is an enlarged cross-sectional view of the main parts of the inner plug 10 and waterproof gasket 15 included in the cap unit 1.

As shown in Figures 1 and 2, the capped container 100 of this embodiment is a beverage container that includes a container body 2 that is open at the top and a cap unit 1 that can be detachably attached to the container body 2, and is capable of keeping the beverage (contents) contained in the container body 2 hot or cold.

Specifically, the container body 2 has an outer container 3 and an inner container 4 made of metal, such as stainless steel. The container body 2 has a vacuum insulation structure in which the outer container 3, which also has an open end, houses the inner container 4, which also has an open end, inside the outer container 3, which also has an open end, with the open ends of the two containers joined together, and a vacuum insulation layer 5 is provided between the outer container 3 and the inner container 4.

The vacuum insulation layer 5 can be formed, for example, by sealing a vent hole in the center of the bottom surface of the outer container 3 with brazing material in a chamber that has been depressurized (evacuated) to a high vacuum.

By having this vacuum insulation structure, the container body 2 can be endowed with the aforementioned heat or cold insulation functions. Furthermore, by having this vacuum insulation structure, the container body 2 is constantly under tension due to the difference between the internal pressure (vacuum pressure) and the external pressure (atmospheric pressure), increasing the mechanical strength of the outer container 3 and inner container 4. This makes it possible to increase the rigidity of the container body 2 even when the plate thicknesses of the outer container 3 and inner container 4 are reduced, thereby enabling the container body 2 to be made lighter.

The container body 2 has a substantially circular bottom surface 2b, a body portion 2c that rises in a substantially cylindrical shape from the outer periphery of the bottom surface 2b, and a mouth/neck portion 2d that rises in a substantially cylindrical shape from the upper side of the body portion 2c. The upper end of the mouth/neck portion 2d opens in a circular shape as the upper opening 2a of the container body 2.

A female thread 6 is provided on the inner surface of the neck portion 2d. Furthermore, below the female thread 6, a ring-shaped protrusion 7 is provided, protruding from the inner surface of the inner container 4 around the entire circumference.

Note that, although the capped container 100 of this embodiment has an overall, generally cylindrical external shape, the external shape of the capped container 100 is not particularly limited and can be modified as appropriate to suit the size, design, etc. In addition, the outer peripheral surface of the container body 2 (outer container 3) may be painted, printed, etc.

The cap unit 1 of this embodiment constitutes a lid that opens and closes the upper opening 2a of the container body 2. Specifically, as shown in Figures 3 and 4, this cap unit 1 includes a cap body 8 that closes the upper opening 2a of the container body 2 when fitted inside the container body 2 from the upper opening 2a, and is structured so that this cap body 8 is attached to the container body 2 by screwing.

The cap body 8 has an outer lid 9 that covers the upper opening 2a of the container body 2, an inner stopper 10 that fits inside the container body 2 through the upper opening 2a, and a detachment mechanism 11 that detachably attaches the inner stopper 10 to the outer lid 9.

As shown in Figures 2 and 5(A) and (B), the outer lid 9 is made of, for example, heat-resistant resin, and has a peripheral wall portion 9a formed in a generally cylindrical shape so that its appearance is continuous with the barrel portion 2c of the container body 2, and an upper wall portion 9b that closes the upper part of the peripheral wall portion 9a.

As shown in Figures 2 and 6 (A) and (B), the inside plug 10 is made of, for example, heat-resistant resin and has a substantially circular bottom wall portion 10a, a substantially cylindrical peripheral wall portion 10b rising from the periphery of the bottom wall portion 10a, a top wall portion 10c closing the upper part of the peripheral wall portion 10b, and a flange portion 10d where the top wall portion 10c protrudes further in the radial direction than the peripheral wall portion 10b.

The inner plug 10 has a bottomed, generally cylindrical lower plug member 12 that forms the bottom wall portion 10a and peripheral wall portion 10b, and a generally circular upper plug member 13 that forms the top wall portion 10c and flange portion 10d. The lower plug member 12 is integrally attached to the underside of the upper plug member 13 by welding or other means. The interior of the inner plug 10 is not limited to air as an insulating layer, and may instead contain insulating material S.

Furthermore, a male thread portion 14 is provided on the outer peripheral surface of the peripheral wall portion 10b (inner plug 10). In the capped container 100, the cap body 8 (cap unit 1) is detachably attached to the container body 2 by threading this male thread portion 14 into the female thread portion 6. Furthermore, the female thread portion 6 and the male thread portion 14 are double-threaded threads that are complementary to each other. When a double-threaded thread is used, the cap body 8 (cap unit 1) can be attached and detached from the container body 2 with a small rotational movement (approximately 180° in this embodiment).

A waterproof gasket 15 is attached integrally to the outer periphery of the lower end of the inner stopper 10. The waterproof gasket 15 is a ring-shaped sealing member that seals the gap between the protruding portion 7 of the container body 2 and the inner stopper 10, and is made of an elastic material such as a heat-resistant rubber or elastomer, such as silicone rubber. The waterproof gasket 15 is formed integrally with the inner stopper 10 (cap body 8) by insert molding, as described below.

The inner plug 10 has a first recess 10e shaped to correspond to the first protrusion 15a that protrudes inward from the upper end of the inner periphery of the watertight gasket 15, and a second recess 10f shaped to correspond to the second protrusion 15b that protrudes upward from the lower end of the inner periphery of the watertight gasket 15. The inner plug 10 also has a third protrusion 10g shaped to correspond to the third recess 15c of the watertight gasket 15 that is formed between the first recess 10e and second recess 10f of the inner plug 10 and is located between the first protrusion 15a and second protrusion 15b of the watertight gasket 15.

In the cap unit 1 of this embodiment, the first convex portion 15a protruding inward of the watertight gasket 15 is formed integrally with the first concave portion 10e of the inside plug 10, and the second convex portion 15b protruding upward of the watertight gasket 15 is formed integrally with the second concave portion 10f of the inside plug 10. Furthermore, the third concave portion 15c of the watertight gasket 15 and the third convex portion 10g of the inside plug 10 are molded integrally, which increases the adhesive strength of the watertight gasket 15 attached integrally to the inside plug 10 (cap body 8) due to the anchor effect of each.

The underside of the inner plug 10 has a bottom wall 10a that is recessed upward, but is flush with the underside of the watertight gasket 15. This makes it difficult for the watertight gasket 15 to peel off from the inner plug 10 at the boundary between the undersides of the inner plug 10 and the watertight gasket 15. Furthermore, because there are no gaps near the boundary, water droplets are less likely to accumulate, making it hygienic.

In addition, two elastic flanges 15d are provided on the outer peripheral surface of the watertight gasket 15, protruding in the radial direction. When the cap body 8 (cap unit 1) is attached to the container body 2, the elastic flanges 15d elastically deform and the watertight gasket 15 comes into close contact with the protruding portion 7 of the container body 2 around the entire circumference. This makes it possible to seal (stop water) the gap between the protruding portion 7 (container body 2) and the inside plug 10 (cap body 8).

The waterproof gasket 15 is not necessarily limited to the shape described above. For example, the number of elastic flange portions 15d is not limited to the two described above, but can be one or more.

Furthermore, the waterproof gasket 15 is not necessarily limited to a configuration provided with the elastic flange portion 15d described above, and its shape, etc., can be modified as appropriate. For example, the waterproof gasket 15 may be configured with an elastic flange portion that protrudes downward and curves from the upper end of the outer periphery.

As shown in Figures 2 to 9, the detachment mechanism 11 is structured so that the inner plug 10 is attached to the outer lid 9 by abutting the upper surface of the inner plug 10 at a position offset from the center of the inner underside of the outer lid 9 and then sliding the inner plug 10 toward the center of the inner underside of the outer lid 9 (the attachment direction).

Specifically, this detachment mechanism 11 includes a guide engagement portion 18 having an engagement hole 16 provided in the outer lid 9 and an engagement piece 17 provided in the inner plug 10, with the engagement piece 17 engaging with the engagement hole 16; a first click locking portion 19 provided in the outer lid 9 and an elastic piece 21 including a second click locking portion 20 provided in the inner plug 10, with a click locking portion 22 that locks either the first click locking portion 19 or the second click locking portion 20 with the other locking portion (in this embodiment, the first click locking portion 19) of the first click locking portion 19 or the second click locking portion 20 (in this embodiment, the second click locking portion 20); and a slide locking portion 24 having a first slide locking portion 23 provided in the outer lid 9, with the flange portion (second slide locking portion) 10d of the inner plug 10 locking with the first slide locking portion 23.

The engagement hole 16 is formed by a hole in the peripheral wall portion 9a located at one radial end of the outer lid 9, with a shape corresponding to the engagement piece 17. Meanwhile, the engagement piece 17 is formed by a protrusion that protrudes outward beyond the flange portion 10d located at one radial end of the inside plug 10.

With the engagement piece 17 inserted into the engagement hole 16, the guide engagement portion 18 can guide the inner plug 10 to slide freely radially relative to the outer lid 9, and when the inner plug 10 is slid to the center of the inner underside of the outer lid 9, the engagement piece 17 can engage with the engagement hole 16.

The first click locking portion 19 is located at the other radial end of the outer lid 9 and consists of a convex portion that protrudes downward from the upper wall portion 9b. Meanwhile, the elastic piece 21 extends in the radial direction from between a pair of slits 25 that cut out the flange portion 10d located at the other radial end of the inside plug 10. The second click locking portion 20 is formed by a recess in which part of the elastic piece 21 is recessed downward in a shape corresponding to the first click locking portion 19.

The click locking portion 22 allows the first click locking portion 19 to lock into the second click locking portion 20 of the elastically deformable elastic piece 21 when the inner plug 10 is slid to the center of the underside of the inner side of the outer lid 9.

The click locking portion 22 also functions as a click mechanism that provides a clicking sensation when the inner plug 10 is slid to the center of the underside of the inside of the outer lid 9. This mechanism allows the elastic piece 21 to elastically deform, providing a clicking sensation when the first click locking portion 19 locks into the second click locking portion 20.

The first slide locking portion 23 is located at the other radial end of the outer lid 9 and is composed of a pair of rib walls that protrude inward from the peripheral wall portion 9a on both sides of the elastic piece 21, approximately parallel to the upper wall portion 9b.

As shown in Figure 4, when the inside plug 10 is slid to the center of the underside of the inside of the outer lid 9, the slide locking portion 24 allows the flange portion (second slide locking portion) 10d to be locked onto the first slide locking portion 23.

In the detachment mechanism 11 configured as described above, the inner plug 10 is inserted into the inside of the outer lid 9 from the position shown in Figure 7. At this time, as shown in Figure 8, the engagement piece 17 is inserted into the engagement hole 16, and then the upper surface of the inner plug 10 is brought into contact with a position offset from the center of the inner underside of the outer lid 9, as shown in Figure 9. From this position, the inner plug 10 is slid toward the center of the inner underside of the outer lid 9 (in the installation direction).

At this time, as shown in Figures 1 to 4, the engagement piece 17 engaged with the engagement hole 16 becomes substantially flush with the side surface of the outer lid 9. Furthermore, the first click engagement portion 19 engages with the second click engagement portion 20, preventing the inside plug 10 from sliding radially (outward) relative to the outer lid 9. Furthermore, the engagement piece 17 of the inside plug 10 engages with the engagement hole 16 located at one radial end of the outer lid 9, and the flange portion (second slide engagement portion) 10d of the inside plug 10 engages with the first slide engagement portion 23 located at the other radial end of the outer lid 9, preventing the inside plug 10 from falling off the outer lid 9 and preventing rotational misalignment of the inside plug 10 relative to the outer lid 9. This leaves the inside plug 10 attached to the center of the underside of the inside of the outer lid 9.

In addition, when the inner plug 10 is attached to the center of the inner underside of the outer lid 9, the inner surface abutment portion 9c on the inner side of the outer lid 9 shown in Figure 5(A) abuts against the straight portion 10h provided on the flange portion 10d shown in Figure 6(A), preventing rattling or misalignment.

As shown in Figure 6 (A), the top wall 10c of the inside plug 10 has upper surface protrusions 10i. The upper surface protrusions 10i are provided at equal intervals, rotating 90° in plan view, so as to protrude upward. The upper surface protrusions 10i prevent deviations in the gap distance between the inside plug 10 and the central underside of the outer lid 9 due to dimensional errors of the inside plug 10 caused by molding when or after the inside plug 10 is attached to the central underside of the outer lid 9. In other words, by fine-tuning the dimensions of the upper surface protrusions 10i, dimensional errors of the inside plug 10 can be absorbed, making it possible to stably attach the inside plug 10 to the central underside of the outer lid 9.

Meanwhile, the detachment mechanism 11 performs the reverse operation of the above-described operation, i.e., by sliding the inside plug 10 relative to the outer lid 9 in the opposite direction (removal direction) to the direction described above, the first click locking portion 19 is released from the second click locking portion 20, and the flange portion (second slide locking portion) 10d is released from the first slide locking portion 23. Next, the engagement of the engagement piece 17 with the engagement hole 16 is released. This allows the inside plug 10 to be removed from the outer lid 9.

In the cap unit 1 of this embodiment, the inner stopper 10 is detachably attached to the outer lid 9, which allows the outer lid 9 and inner stopper 10 to be washed separately, keeping the space between them hygienic.

In the cap unit 1 of this embodiment, as shown in FIG. 10, the lower plug member 12 (inner plug 10) has a boundary surface 12a that faces the upper surface of the watertight gasket 15, an inclined surface 12b that slopes upward from the outside of the watertight gasket 15 on the boundary surface 12a, and an outer peripheral surface 12c that rises upward from the outside of the inclined surface 12b.

The inclined surface 12b forms a linearly inclined surface (C-surface) in a cross section along the axial direction of the lower plug member 12 (inner plug 10). Furthermore, it is preferable that the inclined surface 12b be inclined at an angle θ of 30° to 60° (45° ± 15°) relative to the axial direction of the lower plug member 12 (inner plug 10).

The outer edge of the boundary surface 12a may coincide with the outer upper edge, which is the upper edge of the adhesive surface of the integrated watertight gasket 15, or may be positioned slightly outward (extending) beyond the outer upper edge of the watertight gasket 15. In this case, the distance D by which the boundary surface 12a extends beyond the watertight gasket 15 is preferably 2.0 mm or less.

The smaller the distance D, the more the inclined surface 12b and the outer upper end of the watertight gasket 15 appear to be one continuous, integrated shape, resulting in a more aesthetically pleasing appearance. Furthermore, if the outer upper end of the watertight gasket 15 is located further outboard than the outer end of the boundary surface 12a, this is not desirable, as it may cause peeling on the upper end of the watertight gasket 15 depending on the area where the primer is applied, as described below.

(Method for manufacturing cap unit)
Next, a method for manufacturing the cap unit 1 will be described with reference to FIGS.
11 is a cross-sectional view illustrating the state in which the watertight gasket 15 is integrally formed with the inside plug 10 using a mold 200. FIG. 12 is an enlarged cross-sectional view of the main part shown in FIG.

Note that in Figure 11, the inside plug 10 (lower plug member 12) is upside down compared to the other figures. Therefore, the upward direction in Figures 1 to 10, 12, and 13 is the downward direction in Figure 11, and the downward direction in Figures 1 to 10, 12, and 13 is the upward direction in Figure 11.

In the manufacturing method of the cap unit 1, the watertight gasket 15 is formed integrally with the lower plug member 12 (inner plug 10) by insert molding using a mold 200 that forms a cavity space K shaped to correspond to the watertight gasket 15 between the lower plug member 12 (inner plug 10) and the mold 200.

In addition, insert molding uses a mold 200 that is divided in the axial direction of the lower plug member 12 (inner plug 10). In this embodiment, the mold 200 is divided into three molds 201, 202, and 203.

Of these, the lower mold 201 in Figure 12 forms a cavity space K shaped to correspond to the watertight gasket 15 between it and the lower plug member 12. Meanwhile, the upper mold 202 in Figure 12 is butted against the mold 201 on the outside of the lower plug member 12. A gap G is provided in the mold 202, separating it from the male thread portion 14. Meanwhile, the upper mold 203 in Figure 12, located inside the mold 202, is abutted against the step portion 12d provided on the inside of the lower plug member 12 and the inner circumferential surface 12e rising upward from the outside of the step portion 12d on the inside of the lower plug member 12.

In the manufacturing method of the cap unit 1 of this embodiment, first, plasma discharge treatment is performed on the surface of the molded lower plug member 12, performing a surface modification process to generate polar functional groups on the surface of the resin. Note that the process of generating polar functional groups is not limited to plasma discharge treatment; surface modification processes such as flame treatment, corona discharge treatment, and itro treatment can also be used selectively.

Next, a primer is applied to the surface of the surface-modified lower plug member 12, and the lower plug member 12 is placed in the mold 200. The primer is applied to the boundary surface 12a of the lower plug member 12, as well as to the first recess 10e, second recess 10f, and third protrusion 10g, which will form the boundary surface with the watertight gasket 15.

There are no particular limitations on the composition of the primer, as long as it chemically bonds with the surface of the heat-resistant resin material that forms the lower plug member 12 (inner plug 10), which has been surface-modified in a previous process, and also chemically bonds with the elastic material, such as heat-resistant silicone rubber, that forms the watertight packing 15, improving adhesion.

The method for applying the primer can also be selected as appropriate. For example, if the viscosity of the primer is low, it can be applied by spraying, etc. If the viscosity is high, it can be applied by brush, etc. Other methods include application with a dispenser or dipping.

Next, the mold is closed, forming a cavity space K between the mold 201 and the lower plug member 12, with the mold 201 abutting the inclined surface 12b against the lower plug member 12 placed inside the mold 200. Note that the upward arrow in Figure 12 indicates the direction in which the mold 201 is closed.

At this time, as shown in Figure 12, a force F is applied to the inclined surface 12b that is in contact with the mold 201 in a direction perpendicular to this inclined surface 12b. This distributes the axial force applied from the mold 201 to the lower plug member 12, allowing the mold 201 and inclined surface 12b to come into contact with each other with an appropriate contact pressure, preventing deformation of the lower plug member 12.

Then, molten resin (e.g., liquid silicone) that will become the watertight gasket 15 is injected into the cavity space K using insert molding, and is then retained and molded, thereby forming the watertight gasket 15 integrally with the inner plug 10 (cap body 8).

Generally, when molding liquid silicone rubber, the resin has high fluidity during filling, so even the slightest gap when the mold is closed will result in burrs. For this reason, it is necessary to manufacture the mold with high precision.

Furthermore, in insert molding, it is necessary to minimize gaps while pressing the insert (lower plug member 12 in this embodiment) to prevent deformation. When the insert is made of a resin material, as in this embodiment, even if it is a heat-resistant resin, pressing it too hard into the mold may cause deformation due to the heat of molding and the pressure of closing the mold.

In contrast, in this embodiment, as described above, the inclined surface 12b is inclined at an angle θ, so the mold 201 and inclined surface 12b abut at a 45° angle relative to the axial direction of the mold closure, resulting in appropriate pressure and preventing gaps from forming.

In addition, because the distance between the inclined surface 12b and the step portion 12d and inner peripheral surface 12e that abut against the mold 203 is short, even if there is a dimensional error in the lower plug member 12, it is possible to keep the amount of deformation of the lower plug member 12 caused by closing the mold small.

For this reason, the manufacturing method of the cap unit 1 of this embodiment minimizes deformation of the lower plug member 12 described above, and makes it possible to mold the lower plug member 12 placed in the mold 200 integrally with the waterproof gasket 15 while firmly pressing the lower plug member 12 in the axial direction by the mold 200.

When molding a resin insert with ordinary solid or semi-solid silicone rubber with low fluidity, the shape of the cavity space K must avoid so-called undercut shapes, particularly deep undercut shapes, which are convex or concave in the direction perpendicular to the mold opening and closing direction (the axial direction in this embodiment).

This is because if solid or semi-solid silicone rubber is filled into the cavity space K, the silicone rubber will not reach the deepest part of the undercut, which can easily result in molding defects. Therefore, by shaping the cavity space K in the same axial direction as the mold opening and closing direction and providing it with a slope similar to that of the draft taper, it is possible to make it easier to fill with silicone rubber.

In contrast, in the manufacturing method of the cap unit 1 of this embodiment, liquid silicone rubber is used to integrally mold the waterproof gasket 15 by injection molding. Liquid silicone rubber has high fluidity and can easily be filled into any shape. Therefore, even if the undercut shape is deep, it is not affected and the silicone rubber can reach the deepest part of the undercut and be molded, so the shape of the cavity space K in insert molding does not matter.

In addition, in this embodiment, the first recess 10e of the lower plug member 12 (inner plug 10) has a deep undercut shape that extends inward in the opening and closing direction of the mold 200. This, combined with the second recess 10f that opens in the opening and closing direction of the mold 200, increases the contact area between the lower plug member 12 (inner plug 10) and the watertight gasket 15 in the undercut direction, thereby increasing the adhesion strength.

The two elastic flange portions 15d on the outer peripheral surface of the waterproof gasket 15 also have an undercut shape that faces outward in the opening and closing direction (axial direction) of the mold 203. However, because the waterproof gasket 15 is molded from silicone rubber, the elastic flange portions 15d are elastically deformed when removed from the mold 203 after molding is complete. This allows for so-called forced removal, which means there are fewer restrictions on the shape of the cavity space K and allows for greater freedom in the shape of the cavity space K.

Furthermore, with the manufacturing method of the cap unit 1 of this embodiment, there is no need to secure a portion (pressure allowance) on the outside of the watertight gasket 15 to press the lower plug member 12 in the axial direction, so it is possible to prevent the outer diameter of the watertight gasket 15 from becoming smaller than the outer diameter of the inner plug 10.

Furthermore, rather than using a mold that is divided in a direction perpendicular to the axial direction of the cap body 8, a mold that is divided in the axial direction of the cap body 8 is used. Therefore, due to the mold structure and the shape of the inner plug 10 of the cap body 8 that is inserted, it is possible to increase the number of cap units 1 produced in a single molding run (yield), making it possible to produce large quantities in a short period of time.

The present invention is not necessarily limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, the inclined surface 12b shown in Fig. 10 forms a linearly inclined surface (C surface) in a cross section taken along the axial direction of the inside plug 10, but is not limited to this shape, and may form a convexly inclined surface (R surface) in a cross section taken along the axial direction of the inside plug 10, as in the inclined surface 12f shown in Fig. 13. Fig. 13 is a cross-sectional view showing another shape of the inclined surface 12b shown in Fig. 10.

In this case, too, a force is applied to the inclined surface 12f that comes into contact with the mold 201 in a direction perpendicular to the tangent of this inclined surface 12f, which makes it possible to prevent deformation of the lower plug member 12 while dispersing the axial force applied to the lower plug member 12 from the mold 201. While the inclined surface 12f has a convex curve, a similar effect can be achieved even if it has a concave curve.

For example, the cap unit 1 is configured so that the inner stopper 10 is attached to the container body 2 by screwing it into the upper opening 2a of the container body 2, as described above, but this configuration is not necessarily limited to this. For example, the cap unit 1 can also be configured so that the outer lid 9 is attached to the container body 2 by screwing it into the upper opening 2a of the container body 2 from the outside.

In this configuration, instead of the female thread portion 6 and male thread portion 14 described above, the outer lid 9 (cap body 8) can be removably attached to the container body 2 by threading a male thread portion provided on the outer peripheral surface of the neck portion 2d with a female thread portion provided on the inner peripheral surface of the peripheral wall portion 9a that constitutes the outer lid 9.

Furthermore, the capped container 100 is configured to directly open and close the upper opening 2a of the container body 2, as described above, but is not necessarily limited to this configuration. For example, it is also possible to configure the cap unit 1 to be detachably attached to a shoulder member attached to the container body 2.

Furthermore, it is also possible to configure the lid to be freely opened and closed on the cap body attached to the container body 2. In this configuration, the lid may be attached to the cap body by screwing, or the lid may be attached to the cap body via a hinge portion so that it can be freely rotated.

In the above embodiment, the present invention is illustrated as being applied to a beverage container that has a heat-retaining (or cold-retaining) function provided by the container body 2 having the vacuum insulation structure described above. However, the present invention can be widely applied to a lidded container that includes a container body and a lid that can be detachably attached to the container body.

DESCRIPTION OF SYMBOLS 1...Cap unit 2...Container body 3...Outer container 4...Inner container 5...Vacuum insulation layer 6...Female thread portion 7...Protruding portion 8...Cap body 9...Outer lid 10...Inner plug 10d...Flange portion (second slide locking portion) 10e...First recess 10f...Second recess 10g...Third protrusion 10h...Straight portion 10i...Upper surface protrusion 10j...Flange portion 11...Detachment mechanism 12...Lower plug member 12a...Boundary surface 12b...Inclined surface 12c...Outer peripheral surface 12f...Inclined surface 13...Upper plug member 14...Male thread portion 15...Watertight packing 15a...First protrusion 15b...Second protrusion 15c...Third recess 16...Engagement hole 17...Engagement piece 18...Guide engagement portion 19...First click locking portion 20... Second click locking portion 21... Elastic piece 22... Click locking portion 23... First slide locking portion 24... Slide locking portion 25... Slit 100... Capped container 200... Mold K... Cavity space

Claims (14)

A cap unit that can be detachably attached to a container body having an open top,
a cap body that closes the upper opening of the container body when fitted into the container body from the upper opening,
The cap body includes an inside plug that is fitted into the container body from an upper opening of the container body;
a waterproof packing that is integrally molded in close contact with the outer periphery of the lower end of the inside plug and seals the gap between the container body and the inside plug;
The inside plug has a first recess having a shape corresponding to a first protrusion that protrudes horizontally inward from an upper end portion on an inner circumferential side of the watertight gasket,
The inside plug has a boundary surface facing the upper surface of the watertight gasket, an inclined surface inclined upward from the outer side of the watertight gasket on the boundary surface, and an outer peripheral surface rising upward from the outer side of the inclined surface ,
The outer end of the boundary surface is located outside the outer upper end of the watertight packing,
A cap unit characterized in that the distance by which the outer edge of the boundary surface extends beyond the outer upper edge of the watertight gasket is 2.0 mm or less . The cap unit according to claim 1, characterized in that the inclined surface is linearly inclined in a cross section taken along the axial direction of the inside plug. The cap unit according to claim 1, characterized in that the inclined surface is curved and inclined in a cross section along the axial direction of the inside plug. The cap unit according to claim 1, characterized in that the inner plug has a second recess having a shape corresponding to a second convex portion protruding upward from the lower end portion on the inner periphery of the watertight gasket . The cap unit described in claim 4, characterized in that the inside plug has a third convex portion located between the first concave portion and the second concave portion and having a shape corresponding to a third concave portion formed between the first convex portion and the second convex portion of the watertight gasket. The cap unit according to any one of claims 1 to 5 , characterized in that the bottom surface of the inside plug is flush with the bottom surface of the watertight gasket. A method for manufacturing the cap unit according to any one of claims 1 to 6 , comprising:
When the watertight gasket is integrally formed with the cap body using a mold that forms a cavity space having a shape corresponding to the watertight gasket having an undercut shape between the inside plug and the mold,
Using a mold that is divided in the axial direction of the cap body,
The cavity space is formed between the mold and the inside plug while the mold is in contact with the inclined surface,
A method for manufacturing a cap unit, wherein the waterproof packing is molded from liquid silicone . The cap unit according to any one of claims 1 to 6 ,
A capped container comprising: a container body to which the cap unit is attached. the cap unit has a third protrusion that protrudes downward so as to be in contact with the second protrusion,
The cap unit according to claim 4, characterized in that the waterproof gasket has a flange portion located between the upper surface of the waterproof gasket and the lower end of the third convex portion in the height direction and protruding in the radial direction. A cap unit that can be detachably attached to a container body having an open top,
the cap unit closes the upper opening of the container body in a state where it is fitted into the inside of the container body from the upper opening of the container body,
the cap unit has a waterproof gasket that is integrally molded in close contact with the outer periphery of the lower end side of the cap unit and seals the gap between the container body and the cap unit,
The watertight gasket has a first convex portion that protrudes horizontally inward and a second convex portion that protrudes upward,
the cap unit has a first recess that is recessed inward to correspond to the first protrusion, a second recess that is recessed upward to correspond to the second protrusion, and a third protrusion that protrudes downward to come into contact with the second protrusion,
the cap unit has a boundary surface extending horizontally opposite to an upper surface side of the watertight gasket,
an outer end of the boundary surface of the cap unit is located outside an upper end of the outer side of the watertight packing,
The cap unit is characterized in that the waterproof gasket is located between the upper surface of the waterproof gasket and the lower end of the third convex portion in the height direction and has a flange portion that protrudes in the radial expansion direction. The cap unit according to claim 10, wherein the cap unit has an inclined surface that is inclined upward from outside the waterproof packing at the boundary surface. The cap unit described in claim 10, characterized in that the flange portion protrudes in a radial direction from the outer peripheral surface of the water-stopping gasket, and the outer peripheral surface is located radially inward from the outer end of the cap unit at the boundary surface. The cap unit according to claim 10, wherein a lower surface of the cap unit is flush with a lower surface of the waterproof packing. The cap unit according to claim 10, characterized in that the upper surface of the flange portion is located lower than the upper surface of the waterproof gasket, and the lower surface of the flange portion is located higher than the lower end of the third convex portion.