JP2020111381A - Plastic cap and method of manufacturing the same - Google Patents

Abstract

To provide a plastic cap which has an inside plug cut apart after being molded integrally with a cap body to be combined with a top lid.SOLUTION: A plastic cap consists of: a cap body 1 which is formed of a top plate part and a skirt part and has a pouring nozzle formed surrounding an opening predetermined part, the cap body being fitted and fixed to a container mouth part; and a top lid which consists of a top surface and a circumferential wall hanging from an outer peripheral edge of the top surface. The top lid has a projection part which protrudes downward from a top surface inner face and has an engagement part, and the cap body 1 has an inside plug formed having an annular side wall formed to an outer diameter large enough to come into contact with a pouring nozzle inner face and a bottom part formed below the annular side wall. The inside plug is formed integrally with the cap body 1 across a weakened part which is breakable below a seal part, having an inner diameter large enough to come into contact with the inside plug, of the pouring nozzle, and the annular side wall has an engaged part formed to vertically engage an engaging part of the projection part.SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD The present invention relates to a plastic cap composed of a cap body having a spout which is fixedly used at a container mouth and an upper lid. More specifically, the present invention relates to a plastic cap formed integrally with the cap body and then separated to form an upper lid. The present invention relates to a plastic cap having an inner stopper to be combined and excellent in sealing property and opening property, and a manufacturing method capable of molding the plastic cap with high productivity.

In order to ensure the airtightness of the plastic cap consisting of the cap body and the upper lid that are fixed to the mouth of the container, the pull ring formed at the planned opening of the top plate of the cap body when the contents are first taken out. By pulling up and breaking the weakened portion, an opening for pouring out the contents is formed.
For caps applied to containers filled with viscous contents, the contents are poured out by pressing the body of the container. Is preferably small in diameter. However, with a cap having a small diameter spout, it is difficult to form a pull ring at the planned opening portion, and even if it can be formed, it is difficult to hold with a finger because the pull ring has a small diameter. The opening cannot be easily formed at the beginning.

There is also known a cap having no pull ring at a planned opening portion. For example, in Patent Document 1 below, a cap main body having a top wall provided with a spout cylinder and a hinge connected to the cap main body through a hinge portion are used. The inner lid is provided with an outer lid that is openable and closable with the portion as a fulcrum, and an inner lid that is held in the outer lid and seals the opening of the pouring tube. Also has an inner ring formed inward and fitted into the opening of the spout tube when the upper lid is closed, and the outer lid is continuous with the ceiling wall and the ceiling wall. A skirt wall and a cylinder wall provided on the inner surface of the ceiling wall inward of the skirt wall and having a diameter larger than the opening of the spout cylinder, and the cylinder wall covers the inner lid. A hinge cap having a holding means for holding the inner ring, wherein the inner ring is formed so that at least the hinge portion side is longer than the wall portion, and the inner lid is inside the cylindrical wall, A cap is proposed, which is held so as to be slidable at least in the height direction and moves together with the outer lid when the outer lid is opened and closed.

Since it is not necessary to pull up the pull ring to form an opening when using the hinge cap, the hinge cap can be opened in one action to take out the contents. Further, since the inner lid is a two-piece type cap that is assembled separately from the cap body and the outer lid, the inner lid can move separately from the upper lid, and also has excellent sealing performance. Is.

JP, 2014-162499, A

However, since the hinge cap is a two-piece type cap, two steps of forming the inner lid and assembling the inner lid to the outer lid are added, and the mold for forming the inner lid is added. Therefore, it is still not sufficiently satisfactory in terms of productivity and economy as compared with the molding of a one-piece type cap.
In order to solve such a problem, the present inventors have proposed a plastic cap including a cap body and an upper lid, in which the upper lid is provided with a protruding portion protruding downward from the inner surface of the top surface and having an engaging portion on the outer surface. The cap body is formed with an annular side wall having an outer diameter that allows close contact with the inner surface of the pouring nozzle, and an inner plug having a bottom portion formed below the annular side wall. The protrusion is formed integrally with the cap body through a weakened portion that can be broken below the seal portion having an inner diameter that allows close contact with the inner plug of the pouring nozzle. A plastic cap characterized in that a mating portion and an engaged portion that can be engaged in the vertical direction is formed (Japanese Patent Application No. 2017-129504).

The plastic cap has excellent productivity because it can integrally mold the inner plug, which was conventionally formed as a separate part from the cap body and the upper lid, with the cap body, and also exhibits excellent sealing and opening properties. It is possible to
However, the above-mentioned cap is formed by pushing up the inner plug portion from below in a state where the upper lid is set and sealed on the cap body and separating the inner plug from the cap body and simultaneously assembling it on the upper lid. When pushing up from below, the internal pressure in the sealed upper lid rises, so that a gap is created in the sealing portion between the upper lid and the cap body, or the upper lid opens when subjected to heat treatment. There was a problem. If there is a slight gap between the top lid and the sealing part of the cap body, washing water may flow into the cap during shower washing after filling the contents, and when the top lid is open, The inside may be contaminated. On the other hand, if the fitting between the upper lid and the cap body is excessively strengthened so that the sealed state between the upper lid and the cap body is not affected even when the internal pressure in the upper lid rises, the unsealing property becomes poor.

Therefore, an object of the present invention is to provide a plastic cap having an inner plug which is molded integrally with the cap body and then cut off and assembled to the upper lid, in which the inner plug is detached from the cap body and assembled to the upper lid. It is an object of the present invention to provide a plastic cap which is effectively prevented from increasing in pressure and is excellent in sealing property and opening property, and a manufacturing method capable of molding the plastic cap with high productivity.

According to the present invention, a cap body, which is composed of a top plate portion and a skirt portion, and in which an injection nozzle is formed on the outer surface of the top plate portion so as to surround a planned opening portion, and which is fitted and fixed to the container mouth portion, In a plastic cap consisting of a top surface and an upper lid formed of a peripheral wall hanging down from the outer peripheral edge of the top surface, the upper lid is formed with a protruding portion protruding downward from the inner surface of the top surface and having an engaging portion, The cap body is formed with an inner side wall having an outer diameter capable of being in close contact with the inner surface of the pouring nozzle, and an inner plug having a bottom portion formed below the annular side wall. The protrusion is formed integrally with the cap body through a weakened portion that can be broken below a seal portion having an inner diameter that allows close contact with the inner plug of the dispensing nozzle. And an engaged portion that can be engaged in the up-and-down direction are formed, and a portion capable of forming a ventilation path is formed on the inner surface of the pouring nozzle with the outer surface of the annular side wall of the inner plug separated from the cap body. A plastic cap is provided, characterized in that the air passage forming portion is located below the seal portion and above the breakable weakening portion.

In the plastic cap of the present invention,
1. A plurality of ribs projecting inward are formed on the inner surface of the pouring nozzle, and the air passages are formed between adjacent ribs.
2. The air passage forming portion is located below the engaging portion of the protrusion,
3. The ribs have the same circumferential length, and rib-free regions in which the ribs do not exist are located in diametrically opposite regions of the ribs.
4. The inner plug is formed from an end edge of a planned opening portion of the top plate through a fragile weakened portion,
5. The upper lid is hinged to the cap body,
6. In the state where the upper lid is sealed to the cap body, the fragile weakened portion is ruptured, and the engaged portion of the inner plug separated from the cap body passes over the engaging portion of the projecting portion and can be engaged with each other. At the same time, the outer surface of the annular side wall and the inner surface of the pouring nozzle are in close contact with each other, and when the inner plug passes over the rib, a gap serving as the air passage is formed between the outer surface of the annular side wall and the inner surface of the pouring nozzle. ,
Is preferred.

According to the present invention, in the method for manufacturing the plastic cap described above, after molding the cap body and the upper lid, the bottom portion of the inner plug is pressed from below while the upper lid is sealed to the cap body. The breakable weakened portion is broken, and the internal pressure of the space formed by the upper lid and the cap body top plate portion is released from the air passage formed between the outer surface of the annular side wall and the inner surface of the pouring nozzle. At the same time, there is provided a method of manufacturing a plastic cap, characterized in that the engaging portion of the projecting portion and the engaged portion of the inner plug can be engaged with each other, and the outer surface of the annular side wall and the inner surface of the pouring nozzle are brought into close contact with each other. It

In the plastic cap of the present invention, the inner plug, which has conventionally been formed as a separate component from the cap body and the upper lid, can be integrally molded with the cap body, and therefore has excellent productivity. The inner plug integrally formed with the cap body via the weakened portion is separated from the cap body by pressing the bottom portion of the cap body from below the cap body, and at the same time, the engagement of the protruding portion formed on the upper lid. Since the mating portion and the engaged portion of the inner plug can be engaged with each other, the assembling is easy, and the productivity and the economy are excellent.
Furthermore, when separating the inner plug from the cap body and assembling it on the upper lid, the internal pressure of the inner space of the cap formed by the upper lid and the top plate of the cap body is effectively prevented from rising, and the seal between the upper lid and the cap body is effectively prevented. There is no loss of condition. Particularly in the case of a large-diameter spouting nozzle, the plastic cap of the present invention is effective because a large compressive force is applied to the space inside the cap by pushing up the inside plug.

Further, since the inner plug has an outer diameter capable of closely adhering to the inner surface of the pouring nozzle, in the closed state, it can firmly adhere to the sealing portion of the pouring nozzle to ensure liquid tightness. On the other hand, since the engaging portion of the projecting portion of the upper lid and the engaged portion of the inner stopper are formed to have a vertical gap, the inner stopper is movable with respect to the upper lid. Therefore, since the movement of the upper lid is followed after the movement of the upper lid, the opening force is dispersed and the initial opening force of the upper lid does not increase. Further, even when the upper lid receives a drop impact, the inner stopper does not move together with the upper lid, so that the hermeticity can be maintained.

It is a top view in the state where the upper lid was opened in the hinge cap which is an example of the plastic cap of the present invention. It is a sectional side view in the state where the upper lid of the hinge cap shown in FIG. 1 was opened. It is a sectional side view in the state where the upper lid of the hinge cap shown in FIG. 1 was fitted into the cap body and sealed. FIG. 4 is a side sectional view for explaining a step of setting the inner plug on the upper lid from the state shown in FIG. 3. FIG. 5 is a side cross-sectional view showing a state where the inner plug is pushed up from the state shown in FIG. 4 and a gap serving as a ventilation path is formed between the annular side wall of the inner plug and the inner surface of the pouring nozzle. It is a side sectional view showing the state where the upper lid was closed after the inner stopper engaged with the protrusion of the upper lid. FIG. 7 is a side cross-sectional view showing a state in which the upper lid has started to be opened from the state shown in FIG. 6. FIG. 8 is a side sectional view of the state shown in FIG. 7 with the upper lid opened. It is a sectional side view in the state where the upper lid of the hinge cap in another mode of the cap of the present invention was fitted in the cap body and sealed.

The plastic cap of the present invention will be described with reference to the accompanying drawings.
An example of the plastic cap of the present invention shown in FIGS. 1 to 8 is a cap body 1, an upper lid 20 connected to the cap body 1 by a hinge 2, and a cap body 1 which is separated via a breakable weakening portion 3. It is a hinge cap that is formed integrally and is formed integrally with the inner lid 30 that can be integrated with the upper lid 20 after being separated from the cap body 1.
The cap body 1 fitted and fixed to a container opening (not shown) is composed of a top plate portion 4 and a skirt portion 5 hanging from the peripheral edge of the top plate portion 4. On the inner surface of the skirt portion 5, there are annular projections 6, 6... Which are engaged with engagement recesses of a container mouth 60, which will be described later, and which project inwardly for fixing the cap body 1 to the container mouth. Has been formed.
Further, an annular protrusion 7 for engaging the upper lid 20 and fixing the upper lid 20 is formed at an end portion on the outer surface side of the top plate portion 4, and a pouring direction inside the annular protrusion 7 (opposite to the hinge portion). The pouring nozzle 8 is formed on the (side) side. The pouring nozzle 8 has a high axial height in the pouring direction (left in the drawing) and a low inclination on the hinge 2 side. On the inner surface of the pouring nozzle 8, a plurality of ribs 9, 9... The space between the adjacent ribs 9 and 9 serves as a ventilation path capable of releasing the internal pressure of the cap inner space formed by the upper lid and the cap body top plate portion when the inner plug is separated from the cap body and assembled to the upper lid. As will be described later, the formation positions of the ribs 9, 9... (Below air passage formation portion) are below the engaging portion of the projecting portion of the upper lid, and the pouring nozzle 8 and the inner plug 30 are closed. It is below the seal portion in the state and above the breakable weakening portion 3. On the other hand, on the inner surface of the top plate portion 4, an inner ring 10 that is in close contact with the inner surface of the container mouth portion 60 is formed.

The inner plug, which is generally designated by 30, is a boundary between the pouring nozzle 8 and the inner surface of the top plate portion 4 so as to close a planned opening defined by a boundary portion between the pouring nozzle 8 and the inner surface of the top plate portion 4. It is formed integrally with the cap body 1 through a rupturable score (weakened portion) 3 at a portion (end edge of the opening planned portion). In the specific example shown in FIG. 3, the corner portion of the boundary portion between the pouring nozzle 8 and the inner surface of the top plate portion 4 is formed with a tapered surface 8a so that the inner diameter becomes wider as it goes downward.
The inner plug 30 has a bottom portion 32 formed so as to close an annular side wall 31 extending downward from the breakable score 3 and an axial lower end of the annular side wall 31. Further, as described above, the outer diameter of the annular side wall 31 is such a size as to be in close contact with the inner surface of the spouting nozzle 8, and the axial length of the entire inner plug is approximately the hinge side height in the specific example shown in the drawing. It is formed to have the same length. Further, in the specific example shown in the drawings, the bottom portion 32 is formed with an inclined portion 32a such that the diameter thereof decreases as it goes axially downward, and the inner plug 30 is separated from the cap body and integrated with the upper lid. The fitting into the pouring nozzle 8 is easy.
Further, above the inner surface of the annular side wall 31 of the inner plug 30, an annular upper lid engaging portion (engaged portion) for engaging with an inner plug engaging portion (engaging portion) formed on an upper lid described later. 33 is formed.
Further, an annular guide portion 34 extending axially upward is formed on the bottom portion 32 of the inner plug 30.

An upper lid, generally designated by 20, is formed integrally with the cap body 1 via a hinge 2 at a position opposite to the pouring direction at the upper end of the skirt portion 5 of the cap body 1.
The upper lid 20 is composed of a top surface 21 and a peripheral wall 22 that hangs down from the outer peripheral edge of the top surface 21, and the lower part of the inner surface of the peripheral wall 22 is engaged with the annular projection 7 of the cap body 1 described above. An annular ridge 23 for fixing the upper lid 20 to the cap body 1 in the closed state is formed. A knob 24 for lifting the upper lid 20 upward is formed at the lower end of the circumferential wall 22 at a position opposite to the hinge 2. In the present specification, the term “upper or lower” in the axial direction with respect to the upper lid 20 refers to the upper or lower side with the top surface 21 facing upward (as shown in FIG. 3 ).
Further, on the top surface 21, in the closed state, a peripheral projection 25 extending downward is formed so that the tip of the annular side wall 31 of the inner stopper 30 and the tip thereof coincide. By positioning the circumferential projection 25 at the tip of the annular side wall 31 of the inner plug 30, it is possible to prevent the inner plug 30 from going too far upward when setting the inner plug on the upper lid.

An annular protruding portion 27 that protrudes downward for fixing the inner plug 30 separated from the cap body 1 is formed inside the circumferential protrusion 25 of the upper lid. On the outer peripheral surface of the distal end of the annular protruding portion 27, an inner plug engaging portion (engaging portion) 28 protruding outward is formed in a vertical direction with the upper lid engaging portion (engaged portion) 33 of the inner stopper 30 described above. Is formed so as to be engageable with. It is desirable that the above-mentioned ribs 9, 9... Are located below the engaging portion 28 of the annular protruding portion 27. Thereby, the resistance when the inside plug 30 gets over the rib 9 can be reduced.
By inserting the above-mentioned annular guide portion 34 of the inner stopper 30 into the annular protruding portion 27, the inner stopper 30 separated from the cap body 1 is prevented from tilting, and the protruding portion 27 inclines inward when the upper lid is opened. It is possible to prevent the inner plug 30 from being detached from the upper lid 20. The tip 34a of the annular guide portion 34 is located axially above the engaging portion 28 of the annular protrusion 27 and the upper lid engaging portion of the inner stopper 30 with the inner stopper integrated with the upper lid. It is located below the (engaged portion) 33 in the axial direction (see FIG. 6 ). Accordingly, when the inner plug is set on the upper lid, the engaging portion 28 of the protruding portion 27 can escape inward in the radial direction, and the upper lid engaging portion (engaged portion) 33 of the inner stopper 30 can be smoothly overcome. It will be possible.
The inner diameter of the annular protruding portion 27 is larger than the outer diameter of the annular guide portion 34 and deeper than the length of the guide portion 34. As a result, the inner plug 30 has a movable region with respect to the upper lid 20, and the sealing performance can be improved without increasing the initial opening force of the upper lid as described above.

In the plastic cap of the present invention, after being molded in the state shown in FIGS. 1 and 2, as shown in FIG. 3, the upper lid 20 is put on the cap main body 1 to form the annular projection 7 and the upper lid 20 of the cap main body 1. After the ring-shaped protrusions 23 are engaged and fixed, the bottom 32 of the inner plug 30 is pushed up from below the cap body 1 using the pressing jig 50 as shown in FIG. As a result, the score 3 is broken, and at the same time, the inside plug 30 starts to rise into the pouring nozzle 8. The inner plug 30 starts to rise in the pouring nozzle 8, the guide portion 34 of the inner plug 30 is inserted into the annular protruding portion 27, and the upper lid engaging portion (engaged portion) 33 is in the annular shape of the upper lid 20. The projecting portion 27 can get over the inner plug engaging portion (engaging portion) 28 and can be engaged with each other. Further, the outer surface of the annular side wall 31 comes into contact with a plurality of inwardly protruding ribs 9, 9,... Formed below the inner surface of the pouring nozzle 8 (FIG. 5).
A plurality of ribs 9, 9,... Are formed at intervals along the same axial height of the inner surface of the pouring nozzle 8. In the specific example shown in the drawing, each of the ribs 9, 9,... Has a width of 40° in the circumferential direction, and three ribs are formed at equal intervals. The portion of the annular side wall 31 not in contact with the ribs 9, 9... On the lower outer surface, that is, the portion between the ribs adjacent in the circumferential direction, is between the inner surface of the pouring nozzle 8. A gap 40 is formed as an air passage by the amount of protrusion of the rib 9 inward (FIG. 5).
Therefore, when the inner plug 30 is pushed upward, the air compressed in the space inside the cap defined by the upper lid 20, the cap body top plate portion 4 and the upper surface of the inner plug 30 passes through the gap 40 to the outside (cap Since it is released to the lower side of the main body), the internal pressure of the inner space of the cap does not rise, and the sealed state between the upper lid 20 and the cap main body 1 is maintained. As a result, it is possible to effectively prevent the possibility of invasion of cleaning water in the case of shower washing and the possibility that the upper lid will come off the cap body in the case of heat sterilization.

As shown in FIG. 6, the inside of the pouring nozzle 8 of the inner plug 30 is further raised, the annular side wall 31 of the inner plug 30 gets over the ribs 9, 9,... If the outer diameter of the rib 32a and the diameter formed by the inner tips of the ribs 9, 9,... Are the same, the inner surface of the pouring nozzle 8 and the annular side wall 31 are irrespective of the presence or absence of the ribs 9, 9,. The outer surface of the cap closely contacts and forms a sealed state in which the liquid tightness of the cap can be secured. That is, the seal portion 35 formed by the inner surface of the pouring nozzle 8 and the outer surface of the annular side wall 31 is formed above the ribs 9, 9,... The seal portion 35 can maintain the pouring property of the contents of the pouring nozzle 8 without being affected by the burr of the score 3 after the breakage.
Further, the guide portion 34 of the inner plug 30 is inserted into the annular protrusion 27, so that the annular side wall 31 of the inner plug 30 is removed even when the inner plug 30 is removed from the pouring nozzle 8 (see FIG. 8 ). Is effectively prevented from tilting, and the inner plug does not fall off.

Further, as is apparent from FIG. 6, the inner plug engaging portion (engaging portion) 28 of the annular protrusion 27 and the upper lid engaging portion (engaged portion) 33 of the inner stopper 30 are axially moved when the cap is opened. Although engaged with each other, these engagement relationships are formed so as to have a gap by the distance L in the axial direction. That is, when the upper lid 20 is completely closed, the inner plug engaging portion (engaging portion) 28 of the annular protrusion 27 and the upper lid engaging portion (engaged portion) 33 of the inner plug 30 are as shown in FIG. Since the outer diameter of the guide portion 34 is smaller than the inner diameter of the annular protruding portion 27 and the axial length thereof is short, the upper lid 20 is unsealed. Even if the annular protrusion 27 is slightly pulled up to make the inner protrusion 30 slightly inclined, the position of the inner stopper 30 does not change, and only the annular protrusion 27 rises at the same time as the upper lid 20 so that the inner stopper 30 is discharged from the nozzle. No move from 8 (see FIG. 7). Therefore, in the initial opening of the upper lid 20 (specifically, when trying to release the engagement between the annular projection 7 of the cap body 1 and the annular projection 23 of the upper lid 20), the inner plug 30 almost moves. Since the initial opening force of the upper lid 20 is not increased because it is in close contact with the spouting nozzle 8 without any damage, the openability is not impaired. Moreover, the sealing property of the cap is not released in the initial state of opening.
The upper lid 20 is further pulled up, the annular protruding portion 27 rises by the distance L, and the inner plug engaging portion (engaging portion) 28 of the annular protruding portion 27 becomes the upper lid engaging portion (engaged portion) 33 of the inner stopper 30. By engaging, the inner plug 30 is also pulled up together with the upper lid 20, and the inner plug 30 is integrated with the upper lid 20 and removed from the pouring nozzle 8 as shown in FIG. At this time, since the guide portion 34 of the inner plug 30 is inserted into the annular protruding portion 27, the protruding portion 27 is effectively prevented from falling inward. That is, even when the outer surface of the annular side wall 31 of the inner plug 30 and the inner surface of the pouring nozzle 8 are relatively strongly adhered to each other to improve the sealing property, the inner plug 30 can be prevented from coming off from the upper lid 20.

The above-described plastic cap of the present invention has a relatively large diameter relative to the diameter of the top plate portion of the cap body, which easily raises the internal pressure of the inner space of the cap when the inner plug is cut off from the cap body and pushed up for assembly to the upper lid. Although the hinge cap in which the pouring opening is formed has been described, it is not necessary to form the pouring opening by the pull ring at the start of use of the content, and thus the pouring opening having a small diameter can be used. With a cap having such a small-diameter pouring opening, it is possible to pour only the amount of pressing the container, and squeeze back can be performed easily, so that dripping can be effectively prevented. In the present specification, the small diameter pouring opening means a pouring opening (a planned opening portion) having a diameter such that a pull ring cannot be formed at the planned opening portion, but is not limited to this. A pouring opening (planned opening portion) having a diameter of about 18 mm. The cap having such a small-diameter pouring opening can be suitably used for a container of the type that squeezes out the contents such as a squeeze bottle.

The plastic cap of the present invention is not limited to the specific example shown in the above figures, and various modifications can be made.
That is, in the plastic cap shown in the figure, the cap body and the upper lid are connected by the hinge, and the cap body, the upper lid, and the inner plug are integrally molded, but the upper lid is molded as a separate body from the cap body. It may be fixed to the cap body by screw engagement or the like. Even in this case, since the inner plug can be integrally molded with the cap body, the molding is easier than the conventional cap, and the productivity and the economy are excellent.
In addition, the cap body shown in the figure was a cap with a single-layered skirt that is fitted and fixed to the container mouth by the engaging parts. It is also possible to have a double structure having an outer cylindrical wall on which a score is formed. Further, it is of course possible to use a cap body in which a screw portion is formed on a skirt portion that is fixed to the container mouth portion by screw engagement.

The inner plug shown in FIGS. 1 to 8 has an axial length of about 75% of the axial length of the pouring nozzle on the pouring direction side. Can be appropriately changed depending on the size (caliber and length), the shape of the bottom of the inside plug, and the like.
Further, the shape of the bottom portion of the inner stopper is not limited to the specific example shown in the figure, and various modifications can be made. However, from the viewpoint of easy fitting of the inner stopper to the ejection nozzle, the shape of the bottom portion is It is preferable that the boundary portion between the annular side wall and the bottom has a slanted truncated cone shape, a hemispherical shape, or a stepped shape so that the diameter is smaller than that of the annular side wall.

The circumferential length of each rib formed on the inner surface of the pouring nozzle is the same, and the rib is formed at a position symmetrical to the radial center of the pouring nozzle at the position where the rib is formed. It is preferable that a non-existing region is formed. As a result, the resistance when riding over the rib can be further reduced.
The ribs shown in the drawing were formed at three equal intervals in the height of the pouring nozzle in the same axial direction, but the present invention is not limited to this. Depending on the inner diameter of the pouring nozzle and the circumferential width of the rib, A plurality of them may be provided as appropriate. Further, depending on the axial length of the pouring nozzle and the axial length of the ribs, the plurality of ribs may not necessarily have the same axial height.

Further, the breakable weakening portion, which is a connecting portion between the inner plug and the cap body, is a rib formed on the inner surface of the pouring nozzle below the seal portion having an inner diameter capable of closely adhering to the outer surface of the annular side wall of the inner plug. It is necessary to be positioned further downward than the above.In the specific example shown in the figure, the lower end of the pouring nozzle matches the top plate portion, and a fragile weakened portion is formed at the edge of the opening portion of the cap body. Although the inner plug was integrally formed through the above, the present invention is not limited to this mode. For example, when the lower end of the pouring nozzle is located below the top plate portion, the inner plug may be integrally formed via a weakened portion that can be broken at the lower end of the pouring nozzle. Or, in the case where the inner surface of the pouring nozzle is partially reduced in diameter and the reduced diameter portion serves as a seal portion, the pouring nozzle below the seal portion and ribs. The inner plug may be integrally formed via a weakened portion that can be broken on the inner surface.
Further, in the specific example shown in the drawing, the tapered surface 8a is formed at the boundary between the pouring nozzle 8 and the inner surface of the top plate portion, and the weakened rupturable portion is formed at the upper end of the tapered surface. As shown in FIG. 7, the fragile weakened portion 3 can be formed at the lower end of the boundary portion without forming such a tapered surface. As a result, the axial distance between the rib 9 and the weakened portion 3 becomes longer, and when the inner stopper is set in the pouring nozzle, the weakened portion is not broken and the ribs pass over at the same timing, and the inner stopper is set. It is possible to reduce the resistance when doing.

In the hinge cap, the plastic cap of the present invention can be integrally formed by injection molding or the like with the upper lid opened. Then, after the upper lid is bent and fixed to the cap body, the inner plug portion is pushed upward from below with a pressing jig or the like to tear the fragile weakened portion formed at the boundary between the cap body and the upper end of the inner plug, and It becomes possible to fix the stopper to the top lid.
The cap of the present invention can be molded by a conventionally known method such as injection molding using a resin that has been conventionally used for molding a plastic cap such as an olefin resin such as polyethylene or polypropylene.

INDUSTRIAL APPLICABILITY The plastic cap of the present invention can form the cap body and the inner plug in one piece, is excellent in productivity and sealing property, and does not need to form the pouring opening by pulling up the pull ring, so that the liquid substance can be formed. It can be suitably used as a cap of a container as a content. INDUSTRIAL APPLICABILITY The plastic cap of the present invention is not only a plastic cap having a small-diameter pouring opening in which it is difficult to form a pull ring and easily adjusting the pouring amount of the contents, but also the removal of the inner plug from the cap body. It can be suitably used as a plastic cap having a large-diameter pouring opening, which causes a large increase in internal pressure of the inner space of the cap when assembled to the upper lid.

1 cap body, 2 hinge, 3 weakened part, 4 top plate part, 5 skirt part, 6 annular convex part, 7 annular projection, 8 pouring nozzle, 9 rib, 10 inner ring, 20 upper lid, 21 top surface, 22 rounds Wall, 23 annular projection, 24 knob, 25 circumferential projection, 26 arcuate projection, 27 annular projection, 28 inner plug engaging part (engaging part), 30 inner plug, 31 annular side wall, 32 bottom part, 33 Upper lid engaging portion (engaged portion), 34 guide portion, 40 gap (vent passage), 50 pressing jig, 60 container mouth portion.

Claims (8)

A cap main body that is composed of a top plate portion and a skirt portion, and a pouring nozzle is formed on an outer surface of the top plate portion so as to surround a portion to be opened, a cap body fitted and fixed to a container mouth portion, a top surface and the top surface. In a plastic cap consisting of an upper lid consisting of a peripheral wall hanging from the outer peripheral edge,
The upper lid is formed with a protruding portion protruding downward from the inner surface of the top surface and having an engaging portion,
The cap body is formed with an inner side wall having an outer diameter capable of being in close contact with the inner surface of the pouring nozzle, and an inner plug having a bottom portion formed below the annular side wall. The protrusion is formed integrally with the cap body through a weakened portion that can be broken below a seal portion having an inner diameter that allows close contact with the inner plug of the dispensing nozzle. And an engaged portion that can be engaged in the vertical direction is formed,
The inner surface of the pouring nozzle has a portion capable of forming a ventilation path with the outer surface of the annular side wall of the inner plug separated from the cap body, and the ventilation path forming portion is located below the sealing portion. A plastic cap characterized by being located above the breakable weakened portion. The plastic cap according to claim 1, wherein a plurality of ribs projecting inward are formed on the inner surface of the pouring nozzle, and the ventilation passages are formed between adjacent ribs. The plastic cap according to claim 1, wherein the air passage forming portion is located below the engaging portion of the protrusion. The plastic cap according to claim 2 or 3, wherein each of the ribs has the same circumferential length, and rib-free regions in which the ribs do not exist are located in diametrically opposite regions of each of the ribs. The said inner plug is a plastic cap in any one of Claims 1-4 formed from the edge of the opening part of a top plate part via the weakened part which can be fractured|ruptured. The plastic cap according to claim 1, wherein the upper lid is hinged to the cap body. In the state where the upper lid is sealed to the cap body, the fragile weakened portion is ruptured, and the engaged portion of the inner plug separated from the cap body passes over the engaging portion of the projecting portion and can be engaged with each other. At the same time, the outer surface of the annular side wall and the inner surface of the pouring nozzle are in close contact with each other, and when the inside plug passes over the rib, a gap serving as the air passage is formed between the outer surface of the annular side wall and the inner surface of the pouring nozzle. Item 7. The plastic cap according to any one of Items 2 to 6. It is a manufacturing method of the plastic cap in any one of Claims 1-7, Comprising: After shape|molding the said cap main body and an upper cover, the said upper cover is the state sealed by the cap main body, and the bottom part of the said inside stopper is from below. By pressing, the breakable weakened portion is broken, and the internal pressure of the space formed by the upper lid and the top plate of the cap body from the vent passage formed between the outer surface of the annular side wall and the inner surface of the pouring nozzle. A method of manufacturing a plastic cap, characterized in that the engaging portion of the protruding portion and the engaged portion of the inner plug can be engaged with each other, and the outer surface of the annular side wall and the inner surface of the pouring nozzle are brought into close contact with each other. ..