JP2009083910A - Hinged cap with separating mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel hinged cap without requiring formation of a slit to divide a cylindrical side wall into the outer side wall and the inner side wall like a conventional hinged cap. <P>SOLUTION: The hinged cap includes a cap body 10 having a cylindrical side wall 13 provided with a peak plate portion 11 and a latch peripheral protrusion 12 suspended from a peripheral edge of the peak plate portion 11 to latch a container opening portion 50 with the inner circumferential face of the cylindrical side wall 13 and provided with a pouring cylinder 14 in the peak plate portion, and an outer cap 30 having an upper lid 34 hinge-coupled to the upper end of a skirt wall 32 extending downward from a peripheral edge of an annular top face wall 31 and provided with a protrusion 35 for latching the upper lid with the top face wall. A pair of axial weakening lines 36 are formed in the skirt wall in the vicinity of both ends of the hinge coupled portion so as to extend in an axial direction from the upper end to the lower end of the skirt wall. A notch 37 is formed in the top face wall and the protrusion for latching corresponding to the line. A connecting portion 38 is provided between the lines and between the lower outer circumferential face of the cylindrical side wall and the lower inner circumferential face of the skirt wall of the outer cap corresponding to the hinge coupled portion, that is connected by adhesion or melt-adhesion. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hinge cap with a separation mechanism that has an excellent separation and disposal property that can be easily removed from a container mouth after use and discarded, and more specifically, a cap body fitted and fixed to a container mouth. Further, the present invention relates to a hinge cap having a two-piece structure including an upper cap that can be freely opened and closed to cover the cap body, and an outer cap that is bonded or welded to the cap body.

  A resin hinge cap fitted and fixed to a container mouth is widely used in various applications as a cap of a container filled with various beverages or seasonings. Recently, from the viewpoints of resource reuse, garbage incineration, etc., such caps are required to be separated and disposed of. For example, used caps after taking out the container contents can be used without using special tools. Caps having various structures have been proposed so that can be removed from the container mouth.

For example, in Patent Document 1, the cylindrical side wall of the cap body has an inner wall portion in which a plurality of engagement protrusions with the container mouth portion are formed at appropriate intervals in the circumferential direction, and the inner wall portion is more than the inner wall portion. It is formed from a long outer wall portion, and a tear region and a fixing region are formed on such a cylindrical side wall, and more than 1/4 of the entire circumference of the cylindrical side wall is torn. A hinged cap is described in which an axial weakening line extending in the axial direction from the upper end to the lower end is formed on the outer wall portion at the boundary between the tear region and the fixed region. .
JP 2001-348049 A

  In the conventional hinge cap described in Patent Document 1, the thickness of the cylindrical side wall of the cap body is such that the slit extending downward from the upper end of the hinge connecting portion side is near the lower end of the cylindrical side wall. The cylindrical side wall consists of a double side wall divided into an outer side wall and an inner side wall by this slit, and when the hinge cap is plugged into the container mouth, the outer side wall tightens the inner side wall. It was formed to work. However, the formation of the slit that divides the cylindrical side wall into an outer wall and an inner wall is formed by using a thin-blade slit forming tool (part of a mold) having a curvature at the time of injection molding, A very precise molding method is required to leave a thin skin at the lower end of the cylindrical side wall, and sometimes the slit forming tool may interfere with the mold installed under the cylindrical side wall. In some cases, the lifespan of the product was shortened.

  Accordingly, an object of the present invention is to provide a novel hinge cap that does not require the formation of a slit that divides a cylindrical side wall into an outer wall and an inner side wall as in a conventional hinge cap. An object of the present invention is to provide a hinge cap that is easily separated and can be removed from the container mouth portion.

(1) The hinge cap with a separation mechanism of the present invention has a cylindrical side wall provided with a top plate portion and a locking protrusion that descends from the periphery of the top plate portion and engages with the container mouth portion on the inner peripheral surface, A cap body provided with a pouring tube extending upward from the upper surface of the top plate portion, an annular top surface wall, a skirt wall descending from the periphery of the top surface wall, and an upper end of the skirt wall are connected via a hinge connection portion An outer cap having an upper lid and an outer cap provided with a locking projection for closing and locking the upper lid on the top wall, wherein the skirt wall of the outer cap is adjacent to both ends of the hinge connecting portion A pair of axially weakening lines extending in the axial direction that can be torn from the upper end to the lower end of the skirt wall are formed, and the top wall and the locking projection corresponding to the axially weakening line are provided with notches, The pair of axial weakening lines A connecting portion connected by bonding or welding is provided between a lower outer peripheral surface of the cylindrical side wall of the cap main body corresponding to the hinge connecting portion and a lower inner peripheral surface of the skirt wall of the outer cap. It is characterized by being.
(2) The hinge cap with a separation mechanism of the present invention has a cylindrical side wall provided with a top plate portion and a locking protrusion that descends from the periphery of the top plate portion and engages with the container mouth portion on the inner peripheral surface, A cap body provided with an extraction tube extending upward from the upper surface of the top plate portion;
An annular top surface wall, a skirt wall descending from the peripheral edge of the top surface wall, and an upper lid coupled to the upper end of the skirt wall via a hinge coupling portion, and a locking projection for closing and locking the upper lid to the top surface wall The outer cap is provided with an outer cap, and the skirt wall of the outer cap has an axially weakening line extending in the axial direction that can be torn from the upper end to the lower end of the skirt wall in the vicinity of one end of the hinge connecting portion. The top wall and the locking projection corresponding to the axial direction weakening line are provided with a notch, on the side opposite to the hinge connection portion with respect to the axial direction weakening line and in the vicinity of the axial direction weakening line. Is provided with a connecting portion connected by adhesion or welding between a lower outer peripheral surface of the cylindrical side wall of the cap body and a lower inner peripheral surface of the skirt wall of the outer cap.
(3) In the hinge cap with a separation mechanism of the present invention according to (1) or (2), the top plate portion of the cap body extends upward from the top plate portion and is engaged with the inner peripheral edge of the annular top wall of the outer cap. An engaging projection is provided.
(4) In any one of the above (1) to (3), the hinge cap with a separation mechanism of the present invention has a cylindrical side wall of the cap body facing the position of the pair of axial weakening lines of the outer cap. A pair of axial direction weakening lines 40 extending from the lower end of the cylindrical side wall to a position above the locking protrusion is formed.

  The hinge cap with a separation mechanism according to the present invention includes a cap body that is fitted and fixed to a container mouth portion, and an outer cap that has an upper lid that can be opened and closed to cover the cap body, and is bonded or welded to the cap body Therefore, when the cap is fixed to the container mouth, the cylindrical side wall of the outer cap is hooked by the skirt wall of the cap body, and the cap is firmly engaged with the container mouth and held high. The strength and sealability can be ensured, and after use, the cap can be easily removed from the container mouth and discarded, and the waste is excellent in separation and disposal. In addition, there is no need to form a slit portion with a thin blade slit forming tool at the time of injection molding to form a double side wall divided into an outer wall and an inner side wall, and there is no risk of damage to the thin blade slit forming tool. Therefore, productivity can be improved.

The present invention will be described below based on embodiments shown in the accompanying drawings.
(Embodiment 1)
FIG. 1 is a side cross-sectional view showing a state in which the upper lid of the hinge cap according to the first embodiment of the present invention is closed and fitted to the container mouth, and FIG. Fig. 3 is a top view of the hinge cap according to the first embodiment, Fig. 3 is a bottom view of the hinge cap according to the first embodiment when the upper lid is opened, and Fig. 4 is a diagram of the upper lid of the hinge cap according to the first embodiment. FIG. 5 is a cross-sectional view of the cylindrical side wall and the skirt wall at each position in FIG. 3.

The hinge cap of Embodiment 1 will be described in detail with reference to FIGS.
First, referring to FIG. 1, the hinge cap according to the first embodiment is composed of a so-called two piece of an outer cap 30 having a cap body 10 and an upper lid 34, and the cap body 10 mainly includes a top plate portion 11 and a top plate portion 11. And a locking ridge 12 that locks with the container mouth 50 on the inner peripheral surface of the cylindrical side wall 13 that is lowered from the periphery of the top plate portion of the cap body 10. Is provided.
The outer cap 30 includes an annular top wall 31 and a skirt wall 32 descending from the periphery of the top wall 31, and an upper lid 34 is coupled to the upper end of the skirt wall 32 via a hinge coupling portion 33. The upper lid 34 can be locked to a locking projection 35 provided on the top wall 31.

  On the top surface of the top plate portion 11, a pouring tube 14 for guiding the pouring liquid is formed extending upward, and an endless score 16 is formed on the top plate portion 11 surrounded by the pouring tube 14. A pull ring 17 for tearing the score 16 is connected to the upper surface of the top plate in the score via a support column 18. In use, the content liquid poured out through the pouring opening formed by grasping and pulling up the pull ring 17 and breaking and removing the score 16 is guided by the pouring cylinder 14. Yes. The upper end of the dispensing cylinder 14 spreads out in a trumpet shape so that the liquid can be smoothly discharged. Further, on the hinge connecting portion 33 side, the dispensing cylinder 14 is formed with a low back so that the upper lid 34 is When closing, the upper lid 34 is configured not to interfere with the upper lid when the upper lid 34 is turned.

Next, the outer cap 30 that fits the cap body so that the outside of the cap body 10 is hooked will be described. An upper lid 34 that forms the upper portion of the outer cap 30 is connected to the upper end of the skirt wall 32 that forms the lower portion of the outer cap 30 via a hinge connecting portion 33 to constitute the outer cap 30. The hinge connecting portion 33 is formed of a central wide band portion 33a and small width band portions 33b and 33c on both sides thereof.
The skirt wall 32 of the outer cap 30 has a pair of axial weakening lines 36a and 36b extending in the axial direction that can be torn from the upper end to the lower end of the skirt wall 32 in the vicinity of both ends of the hinge connecting portion 33. By tearing the axial weakening lines 36a, 36b of the skirt wall 32, the cylindrical side wall 13 of the cap body 10 is released from the tagging state, and the hinge cap can be easily removed from the container mouth portion 50. As the shape of the axial direction weakening lines 36a and 36b, it is preferable that the score of the wall of the skirt wall 32 is made partially thin (thin line, see FIG. 5A) because it can be easily broken.

  Further, the top wall 31 and the locking projection 35 corresponding to the axial direction weakening line are provided with a notch 37 having a short dimension at a position where the axial direction weakening lines 36a and 36b are extended. The notches 37 are resin missing portions (portions without resin) provided on the top wall 31 and the locking projections 35 for easily tearing the axial direction weakening lines 36a and 36b.

  Further, the upper cap 34 is hingedly connected to the upper end portion of the skirt wall 32 of the outer cap 30, and a top plate portion 34a is formed on the ceiling of the upper lid 34. On the inner surface of the top plate portion 34a, A circumferential projection 34b for sealing is formed, and when the upper lid 34 is turned and closed, the circumferential projection 34b for sealing comes into close contact with the inner surface of the dispensing cylinder 14 for guiding the dispensing liquid, The sealing performance after forming the dispensing opening is secured.

  The top plate portion 11 of the cap body 10 is provided with an engagement protrusion 15 extending upward from the top plate portion 11 so as to engage with the inner peripheral edge 39 of the annular top wall 31 of the outer cap 30. By this engagement, the outer cap 30 is fixed to the cap body 10 and the floating of the outer cap 30 is prevented.

  Furthermore, a locking projection 35 is provided above the annular top wall 31, and when the upper lid 34 is closed, the recess 34 c formed on the lower inner surface of the upper lid 34 is locked, thereby lowering the lower surface of the upper lid 34. It can adhere to the upper surface of the annular top wall 31 without any gaps, and the closed state of the upper lid can be maintained.

  Next, a description will be given of a connecting portion in which the cap body and the outer cap are integrated into a hinge cap. That is, between the pair of axial weakening lines 36 a and 36 b, between the lower outer peripheral surface of the cylindrical side wall 13 of the cap body 10 corresponding to the hinge connecting portion 33 and the lower inner peripheral surface of the skirt wall 32 of the outer cap 30. A connecting portion 38 connected by adhesion or welding is provided therebetween. The connecting portion 38 is formed by connecting the cylindrical side wall 13 and the skirt wall 32 via an adhesive or by melting a part of the cylindrical side wall 13 and / or the skirt wall 32. Means such as laser and ultrasonic waves can be used for melting. Note that a connecting portion 38 exists between the pair of axial weakening lines 36a and 36b, but there is no connection between the lower outer peripheral surface of the cylindrical side wall 13 and the lower inner peripheral surface of the skirt wall 32 of the outer cap 30. It is a connection part 38x. However, a part of the region with the non-connection portion 38x may be connected by welding or the like. In particular, a connecting portion may be provided at a portion opposite to the hinge connecting portion 33.

  As shown in an enlarged view in FIG. 5A, the cylindrical side wall 13 of the cap body 10 facing the position of the pair of axial weakening lines 36a and 36b, which are scores formed on the outer cap 30, has a cylindrical shape. It is preferable that a pair of axial direction weakening lines 40 extending from the lower end of the side wall 13 to a position above the locking protrusion 12 is formed. After this axial direction weakening line 40 is provided and the cylindrical side wall 13 is thinned to a position above the locking protrusion 12, the axial direction weakening lines 36a and 36b are torn and the skirt wall 32 is separated. Further, by tearing the axial direction weakening line 40, the locking ridge 12 of the cylindrical side wall 13 easily extends outward from the container mouth portion 50, and the hinge cap can be easily removed from the container mouth portion 50. In this embodiment, the axial direction weakening line 40 is a score formed to be thin enough to be torn, but may be formed from a slit that is completely cut out. 5B is a cross section of a portion where the connection portion 38 is provided, and FIG. 5C is a cross section of a portion where the connection portion 38 is not provided (non-connection portion 38x). is there.

Next, the removal from the container mouth part of the hinge cap of Embodiment 1 is demonstrated.
6 is a side sectional view showing a state in which the outer cap is pulled forward, and FIG. 7 is a side sectional view showing a state in which the hinge cap is removed from the container mouth and separated. The removal of the cap main body 10 from the container mouth portion 50 starts from the first stage by holding the upper lid 34 by hand and pulling it forward (in the direction of the arrow in FIG. 6) and tearing the axial weakening lines 36a and 36b. Next, the upper lid 34 is lifted upward (in the direction of the arrow in FIG. 7) and removed from the container mouth portion 50. At this time, the axial direction weakening line 40 is torn.
In this case, the axial direction weakening lines 36a and 36b are formed in the skirt wall 32, and the upper top wall 31 and the locking projection 35 corresponding to the axial direction weakening lines 36a and 36b are provided with notches 37. Therefore, the inner peripheral edge 39 of the annular top wall of the outer cap 30 can be easily detached from the engaging projection 15 of the cylindrical side wall 13 of the cap body 10 and can be pulled toward the front. Then, the hinge cap in the state of FIG. 6 is removed from the container mouth portion 50 in a state where the cap body 10 and the outer cap 30 are connected by the connection portion 38 (see FIG. 7).

(Embodiment 2)
FIG. 8 is a side cross-sectional view showing a state in which the upper lid of the hinge cap according to the second embodiment of the present invention is closed and fitted to the container mouth, and FIG. 9 is a plan view of the hinge cap according to the second embodiment when the upper lid is opened. FIG. 10 is a bottom view of the hinge cap of the second embodiment with the upper lid opened, and FIG. 11 is a top view of the hinge cap of the second embodiment opened. FIG. 12 is a cross-sectional view of the cylindrical side wall and the skirt wall at each position in FIG. 11.
The hinge cap of Embodiment 2 is the same as the hinge cap of Embodiment 1.
(A) A pour-out that extends downward from the top surface of the top plate portion and has a cylindrical side wall provided with a locking ridge that descends from the periphery of the top plate portion and engages with the container mouth portion on the inner peripheral surface. A cap body provided with a cylinder, an annular top surface wall, a skirt wall descending from the periphery of the top surface wall, and an upper lid connected to the upper end of the skirt wall via a hinge connecting portion. An outer cap provided with a locking projection for locking the lid, and an axial weakening line extending in the axial direction that can be torn from the upper end to the lower end of the skirt wall is formed on the skirt wall of the outer cap It is the same in that the top wall corresponding to the axial direction weakening line and the locking projection are provided with notches,
(B) A point where the axial direction weakening line is formed near one end of the hinge connecting portion, the connecting portion is opposite to the hinge connecting portion with respect to the axial direction weakening line, and near the axial direction weakening line, the cap The difference is that it is provided between the lower outer peripheral surface of the cylindrical side wall of the main body and the lower inner peripheral surface of the skirt wall of the outer cap.

That is, in the hinge cap according to the second embodiment, the connecting portion 38 that connects the lower end of the cylindrical side wall and the skirt wall 32 is formed on the lower outer peripheral surface of the cylindrical side wall 13 of the cap body 10 and the lower inner periphery of the skirt wall 32 of the outer cap 30. A predetermined length is formed between the surface and the axial weakening line 36 on the side opposite to the hinge connecting portion 33 and in the vicinity of the axial weakening line 36.
In addition, the connecting portion 38 in the second embodiment starts from the axial direction weakening line 36 formed on the skirt wall 32 and starts in the opposite direction to the hinge connecting portion 33, for example, 1 / of the entire circumference of the skirt wall 32. It is formed to extend in the circumferential direction over about 6 (about 60 degrees).

Also in the hinge cap of the second embodiment, as shown in detail in FIG. 12 (d), the cylindrical side wall 13 of the cap body 10 facing the position of the axial direction weakening line 36, which is a score formed on the outer cap 30, It is preferable that a pair of axial direction weakening lines 40 extending from the lower end of the cylindrical side wall 13 to a position above the locking protrusion 12 is formed.
Further, as shown in FIG. 12G, the axial direction weakening line 40 is also formed on the cylindrical side wall 13 corresponding to the notch 37 formed on the top surface wall 31 and the locking projection 35. Is desirable. By providing the notches 37, as shown in FIG. 13, when the skirt wall 32 is separated by pulling the upper lid, the skirt wall 32 bends outward, and an axial direction weakening line 40 is provided. By being made, it can peel from the cylindrical side wall 13 easily.
In addition, FIG.12 (e) is a cross section of the part in which the connection part 38 is provided, FIG.12 (f) is a cross section of the part (non-connection part 38x) in which the connection part 38 is not provided, FIG. 12G is a cross section of a portion where the connecting portion 38 is not provided (non-connecting portion 38x) and a portion where the notch 37 is formed in the top wall 31 and the locking projection 35. This portion becomes a bent portion as shown in FIG. 13 to facilitate peeling of the skirt wall 32.

Next, removal of the hinge cap of the second embodiment from the container mouth will be described.
FIG. 13 is a top view showing a state where the outer cap is pulled toward the front and the outer cap is removed from the cap body, and FIG. 14 is a side view of FIG.
To remove the cap body 10 from the container mouth portion 50, hold the upper lid 34 with your hand and pull the axial weakening line 36 to the front, hold the upper lid 34 pulled toward you with your hand, what is the axial weakening line 36? The skirt wall 32 can be sequentially pulled away from the tubular side wall 13 in the direction of the arrow q in FIG. 13 (see FIG. 13).

In the hinge cap according to the second embodiment, no connection portion is provided below the hinge coupling portion 33, and the upper top wall 31 and the locking protrusion 35 corresponding to the axial direction weakening line 36 are notched 37. Therefore, the inner peripheral edge 39 of the annular top wall 31 of the outer cap 30 is disengaged from the engaging projection 15 of the cylindrical side wall 13 of the cap body 10, and the skirt wall 32 of the upper lid 34 is easily removed from the cylindrical side wall 13. Can be peeled off.
The hinge cap in the state shown in FIG. 13 is released from the state in which the cylindrical side wall 13 of the cap body 10 is tightened by the skirt wall 32 of the outer cap 30, so that the upper lid 34 is lifted upward and the container mouth part 50. Can be removed from.

The hinge cap with a separation mechanism of the present invention comprises two pieces: a cap body that is fitted and fixed to a container mouth portion, and an outer cap that has an upper lid that is provided on the cap body so as to be openable and closable via a hinge connecting portion. Therefore, when the cap is fixed to the container mouth portion, the cylindrical side wall is hooked by the skirt wall, and the cap can be firmly engaged with the container mouth portion to ensure high holding force and sealing performance. After use, the cap can be easily removed from the container mouth and discarded, which is excellent in separation and disposal.
In addition, there is no need to form a slit portion with a thin blade slit forming tool at the time of injection molding to form a double side wall divided into an outer wall and an inner side wall, and there is no risk of damage to the thin blade slit forming tool. Therefore, productivity can be improved.

It is side surface sectional drawing of the state fitted and fixed to the container mouth part in the state which closed the upper cover of the hinge cap of Embodiment 1 of this invention. It is a top view in the state where the upper lid in the hinge cap of Embodiment 1 was opened. It is a bottom view in the state where the upper lid in the hinge cap of Embodiment 1 was opened. It is side surface sectional drawing in the state which opened the upper cover in the hinge cap of Embodiment 1. It is sectional drawing of the cylindrical side wall and skirt wall in each position of FIG. It is side surface sectional drawing which shows the state which pulled the outer cap of the hinge cap of Embodiment 1 to this side. It is side surface sectional drawing which shows the state which removes and separates the hinge cap of Embodiment 1 from a container opening part. It is side surface sectional drawing of the state fitted and fixed to the container mouth part in the state which closed the upper cover of the hinge cap of Embodiment 2 of this invention. It is a top view in the state where the upper lid in the hinge cap of Embodiment 2 was opened. It is a bottom view in the state where the upper lid in the hinge cap of Embodiment 2 was opened. It is side surface sectional drawing in the state which opened the upper cover in the hinge cap of Embodiment 2. It is sectional drawing of the cylindrical side wall and skirt wall in each position of FIG. It is a top view which shows the state which pulled the outer cap in the hinge cap of Embodiment 2, and removed the outer cap from the cap main body. FIG. 14 is a side view of FIG. 13.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10: Cap main body 11: Top plate part 12: Locking protrusion 13: Cylindrical side wall 14: Extraction cylinder 15: Engagement protrusion 16: Score 17: Pull ring 18: Support | pillar 23: Engagement protrusion 30: Outer cap 31: Annular Top wall 32: Skirt wall 33: Hinge connection part 33a, 33b, 33c: Band part 34: Upper lid 34a: Top plate part 34b: Circumferential protrusion 34c: Recess 35: Locking protrusion 36, 36a, 36b: Axial direction weakening Line 37: Notch 38: Connection part 38x: Non-connection part 39: Inner peripheral edge 40: Axial direction weakening line 50: Container mouth part

Claims (4)

A top plate portion and a cylindrical side wall provided with locking ridges that descend from the periphery of the top plate portion and engage with the container mouth portion are provided on the inner peripheral surface, and an extraction tube extending upward from the upper surface of the top plate portion is provided. A cap body, an annular top wall, a skirt wall descending from the periphery of the top wall, and an upper lid connected to the upper end of the skirt wall via a hinge connecting portion, and the upper lid is closed on the top wall In the hinge cap comprising an outer cap provided with a locking projection for locking,
The skirt wall of the outer cap is formed with a pair of axial weakening lines extending in the axial direction that can be torn from the upper end to the lower end of the skirt wall in the vicinity of both ends of the hinge connecting portion, and a ceiling corresponding to the axial weakening line. The face wall and the locking projection are provided with a notch, which is between the pair of axial weakening lines, the lower outer peripheral surface of the cylindrical side wall of the cap body corresponding to the hinge connecting portion, and the outer cap. A hinge cap with a separation mechanism, characterized in that a connection portion connected by adhesion or welding is provided between the inner peripheral surface of the skirt wall lower portion. A top plate portion and a cylindrical side wall provided with locking ridges that descend from the periphery of the top plate portion and engage with the container mouth portion are provided on the inner peripheral surface, and an extraction tube extending upward from the upper surface of the top plate portion is provided. A cap body, an annular top wall, a skirt wall descending from the periphery of the top wall, and an upper lid connected to the upper end of the skirt wall via a hinge connecting portion, and the upper lid is closed on the top wall In the hinge cap comprising an outer cap provided with a locking projection for locking,
An axial weakening line extending in the axial direction that can be torn from the upper end to the lower end of the skirt wall is formed in the skirt wall of the outer cap in the vicinity of one end of the hinge connecting portion, and the top wall corresponding to the axial weakening line and The locking projection is provided with a notch, on the opposite side of the axial weakening line from the hinge connecting portion and in the vicinity of the axial weakening line, a lower outer peripheral surface of the cylindrical side wall of the cap body A hinge cap with a separation mechanism, characterized in that a connection portion connected by adhesion or welding is provided between the outer peripheral surface of the lower portion of the skirt wall of the outer cap. The top plate portion of the cap body is provided with an engaging protrusion that extends upward from the top plate portion and engages with the inner peripheral edge of the annular top surface wall of the outer cap. Hinge cap. A pair of axial direction weakening lines extending from the lower end of the cylindrical side wall to a position above the locking protrusion is formed on the cylindrical side wall of the cap body facing the position of the pair of axial direction weakening lines of the outer cap. The hinge cap according to claim 1, wherein the hinge cap is formed.

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