WO2007122971A1

WO2007122971A1 - Metal can

Info

Publication number: WO2007122971A1
Application number: PCT/JP2007/056790
Authority: WO
Inventors: Yasuhisa Yokota; Zenrou Shirane; Eiji Tsuda; Yousuke Ogawa
Original assignee: Toyo Seikan Kaisha, Ltd.
Priority date: 2006-04-17
Filing date: 2007-03-29
Publication date: 2007-11-01
Also published as: CN101421169B; JP5051394B2; KR20080106420A; CN101421169A; JPWO2007122971A1; KR101020379B1

Abstract

A metal can having a cap (20) that is fixedly fastened to the periphery of a bead part (14) and is opened by breaking up a score by pulling a tab, in which the bead part (14) is formed by curing outward the opening peripheral edge at the end of a mouth (13) that continues to a body and is tilted inward. Since the bead part is tilted inward, the can can provide sufficient airtightness even if a small-diameter maxicap of a common structure is used, where, in the common structure, the airtightness is secured at a portion closer to some extent to the center of the cap.

Description

Specification

Metal can

Technical field

[0001] The present invention relates to a metal can in which a maxi cap is fastened and fixed to a mouth portion continuing from a trunk portion.

Background art

Conventionally, a metal can with a maxi cap tightened has been proposed (see Patent Document 1). This metal can is scored by pulling a tab on a bead formed by curling the opening edge of the mouth formed continuously from the metal can body (body) by pulling a tab (a line-shaped weakening). The maxi cap that is torn and open the part is clamped and fixed. According to such a metal can, it is possible to realize a metal can that is easy to pour the inner solution from the mouth portion that can be made smaller in diameter than the body portion and that is easy to open.

Patent Document 1: Japanese Utility Model Publication No. 58-88328

Disclosure of the invention

Problems to be solved by the invention

[0003] Meanwhile, a maxi cap having a relatively small diameter is widely used as a stopper for a bottle container, and this general small-cap maxi cap has a structure as shown in FIG. In FIG. 1, the maxi cap 20 has a metal cap body 23 composed of a disc-shaped cap head portion 23a and a side portion 23b erected from the outer periphery of the cap head portion 23a. The liner member 24 made of synthetic resin is fixed to the inner surface of the 23a. The liner member 24 substantially covers the inner surface of the cap head portion 23a of the cap body 23, and a receiving portion 24a for receiving a bead portion on the metal can side and ensuring airtightness is formed on the peripheral portion thereof. Yes. The receiving portion 24a is formed with a groove 24aa over the entire circumference.

[0004] A gap 25 is formed between the receiving portion 24a formed on the peripheral portion of the liner member 24 and the inner surface of the side portion 23b of the cap body 23. The gap 25 is caused by a technique for forming the liner member 24 on the inner surface of the cap body 23. This liner member 24 is As shown in FIGS. 2 (a), 2 (b) and FIG. 3, it is formed on the inner surface of the cap body 23 by injection molding.

[0005] That is, as shown in FIG. 2 (a), the softened lump P is set on the inner surface of the cap head portion 23a of the cap body 23 set in the lower mold (not shown). The upper die is composed of a center punch 100, a center bushing 101 disposed on the outer periphery of the center punch 100, and a positioning sleeve 102 slidably disposed on the outer periphery of the center pushing 101. Mold opening is possible.

[0006] As described above, in the state where the soft lump P is set on the inner surface of the cap head portion 23a of the cap body 23 set in the lower mold, first, the upper mold positioning sleeve 102 is formed. The front end of the injured cap body 23 is set so as to abut the boundary between the cap head 23a and the side 23b along the inner surface of the side 23b. This restricts the movement of the cap body 23 (positioning). Next, the upper die center punch 100 and the center bushing 101 are integrally lowered, and the upper die and the lower die are clamped. Then, as shown in FIG. 2 (b), the softened lumps P move into the cavity formed by the center punch 100, the center push 101 and the mouth categorizing sleeve 102, or contact the upper mold. Is formed into the shape of the tip surface of the center punch 100 and the center pushing 101.

[0007] Then, as shown in FIG. 3, the center punch 100, the center pushing 101, and the positioning sleeve 102 are integrally isolated from the cap body 23 at an appropriate timing when the resin is expected to harden (mold). Opening) completes the maxi cap 20 in which the liner member 24 (resin layer) having a predetermined shape is formed on the inner surface of the cap head portion 23a of the cap body 23. As described above, the positioning sleeve 102 is set along the inner surface of the side portion 23b of the cap body 23 so that the tip end of the positioning sleeve 102 abuts on the boundary between the cap head portion 23a and the side portion 23b. Since the mold clamping is performed, a gap 25 corresponding to the shape of the tip portion of the positioning sleeve 102 is formed between the receiving portion 24a of the liner member 24 and the side portion 23b of the cap body 23.

[0008] Referring back to FIG. 1, the relative positional relationship between the maxi cap 20 and the mouth 51 of the metal can 50 is that of the bead 52 formed by curling the tip of the mouth 51 outward. The exterior is maxi The top portion of the bead portion 52 contacts the groove 23aa of the receiving portion 24a located at the peripheral edge portion of the liner member 24 formed on the inner surface of the maxicap 20 and contacts the inner surface of the side portion 23b of the top plate 20. I must. Otherwise, when the side portion 23b of the maxi cap 20 is fastened to the bead portion 52, the top portion of the bead portion 52 does not fit into the groove 24aa of the receiving portion 24a of the liner member 24, and the liner member There is a risk that 24 will not provide sufficient sealing.

[0009] In the conventional metal can 50 in which the mouth portion 51 rises straight up to the curl start position Pes of the bead portion 52 and the inner diameter Din thereof is substantially constant, the gap portion 25 approaches the center direction of the cap head portion 23a. The width Lc (curl width) of the bead portion 52 needs to be relatively large so that the top of the bead portion 52 faces the groove 2 4aa of the receiving portion 24a of the liner member 24 (part for ensuring airtightness). There is. However, when the width Lc of the bead portion 52 is increased, there is a problem that the strength of the bead portion 52 is lowered. If the strength of the bead portion 52 is thus reduced, the maxi cap 20 cannot be firmly clamped to the bead portion 52, and sufficient airtightness may not be obtained.

[0010] The present invention solves the conventional problems as described above, and has a small-diameter maxi cap having a general structure in which a hermeticity is secured at a portion slightly deviated in the central direction. The present invention provides a metal can capable of obtaining sufficient airtightness even when used.

Means for solving the problem

[0011] The metal can according to the present invention has a cap for tearing and opening the score by pulling a tab on a bead portion formed by curling the tip of the mouth portion following the trunk portion outward. A metal can that is fastened and fixed, wherein the bead portion is inclined inward.

[0012] With such a configuration, the bead portion formed at the distal end portion of the mouth portion is inclined inward, so that airtightness is ensured at a portion slightly deviated in the central direction. When a maxi cap with a small diameter, which is a general structure, is fastened to the bead portion, even if the width of the bead portion is not particularly large, the bead portion of the bead portion is located to a certain extent in the central direction of the cap. You will be able to receive the top.

[0013] Even if the bead portion is entirely inclined, the bead portion is partially inclined. It may be. In the latter case, the metal can according to the present invention can be configured such that the upper end portion of the bead portion is inclined inward.

[0014] Further, in the metal can according to the present invention, the inner diameter of the can at the start of curling outward of the bead portion is smaller than the inner diameter of the can corresponding to the lower end portion of the bead portion. can do.

With such a configuration, the inner diameter of the can at the curl start position located above the lower end portion of the bead portion is smaller than the inner diameter of the can corresponding to the lower end portion, so that the bead portion is inclined inward. It becomes the structure.

[0016] In the metal can according to the present invention, the bead portion may have a structure in which a curled tip portion is in contact with an outer surface of the mouth portion.

[0017] With such a configuration, the curled tip of the bead portion is in contact with the outer surface of the mouth portion. Therefore, when the cap is tightened on the bead portion, a force is applied in the direction of crushing the curled bead portion. Even if it acts, it will be able to resist the force in the direction of stretching at its tip. As a result, the cap can be tightened relatively strongly, and the airtightness of the metal can can be maintained relatively high.

[0018] Furthermore, the metal can according to the present invention may have a structure in which the curled tip of the bead portion is substantially perpendicular to the outer surface of the mouth portion.

[0019] With such a configuration, the curled tip of the bead portion comes into contact with the outer surface of the mouth portion so as to substantially perpendicularly strike, so that the degree of tension at the tip can be further strengthened. As a result, the cap can be tightened more firmly, and the hermeticity of the metal can can be maintained higher.

[0020] Further, the metal can according to the present invention can be configured such that the outer corner of the curled tip of the bead portion abuts against the outer surface of the mouth portion.

[0021] With such a configuration, the curled tip of the bead part comes into contact with the outer surface of the mouth so that the outer corner of the bead hits, so that the degree of tension at the tip is maintained to some extent, but the tip Can be relaxed compared to the case where it hits the outer surface of the mouth substantially vertically. As a result, the cap can be tightened to the bead portion relatively strongly, while the cap can be removed relatively easily. The invention's effect

[0022] According to the metal can according to the present invention, a small-diameter maxi cap having a general structure in which airtightness is ensured at a portion somewhat deviated in the center direction is fastened to the bead portion. In this case, even if the width of the bead portion is not particularly large, the top portion of the bead portion can be received at the portion of the cap that is somewhat away from the central direction. Even with a caliber maxi cap, sufficient airtightness can be obtained.

Brief Description of Drawings

FIG. 1 is a diagram showing a relative positional relationship between a bead portion formed in a mouth portion and a cap in a conventional metal can.

[FIG. 2] FIG. 2 is a diagram showing a state (a) in which a fat mass is set in the cap in a step of molding the cap, and a state (b) in which the resin is molded in the cap.

FIG. 3 is a view showing a state in which a liner member made of resin is formed in the cap.

FIG. 4 is a front view (a) and a side view showing the metal can according to the first embodiment of the present invention.

(b), (c) and plan view (d).

FIG. 5 is a cross-sectional view taken along the line AA in FIG. 4 (a).

FIG. 6 is a detailed cross-sectional view of a B part in FIG. 4 (c).

[FIG. 7] FIG. 7 is a diagram showing intermediate steps (a) and (b) of forming a bead portion at the mouth portion of a metal can.

FIG. 8 is a diagram showing a final process of forming a bead portion in the mouth portion of a metal can.

[FIG. 9] FIG. 9 is a cross-sectional view showing in detail the relative positional relationship between a bead portion formed at the mouth portion of a metal can and a cap.

[FIG. 10] FIG. 10 is a view showing a main part of the tightening machine.

[FIG. 11] FIG. 11 is a diagram showing intermediate processes (a) and (b) in which the cap is fastened and fixed to the mouth of the metal can.

[FIG. 12] FIG. 12 is a diagram showing a final process in which the cap is clamped and fixed to the mouth portion of the metal can.

FIG. 13 is a cross-sectional view showing the main part of a metal can according to the second embodiment of the present invention. It is.

14 is a cross-sectional view showing in detail a bead portion in the metal can shown in FIG.

[FIG. 15] FIG. 15 is a table showing the results of a drop airtightness evaluation test.

Explanation of symbols

10 Metal can

11 Torso

12 shoulder

13 mouth

14 Bead section

14a Tip

14aa outside corner

14ab inner corner

20 Cap (Maxi Cap)

21 tabs

22a, 22b score

23 Cap body

23a Cap head

23b side

23ba Bottom edge

24 Liner material

24a receiving part

24aa groove

25 Clearance

100 center punch

101 center pushing

102 Locating sleeve

201 1st tool 202 Second Tour

203 3rd Tour

301 Plunger

302i, 302j sealing sleeve

302ia, 302ja sealing protrusion

302ib, 302jb inclined surface

303 Pushing sleeve

304 compression panel

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0026] The metal can according to the first embodiment of the present invention is configured as shown in Figs. 4 is a front view (a), a side view (b), (c) and a plan view (d) of the metal can according to the first embodiment of the present invention, and FIG. FIG. 4A is a cross-sectional view taken along line AA in FIG. 4A, and FIG.

4 and 5, the metal can 10 has a structure that extends from the bottomed cylindrical body portion 11 through the shoulder portion 12 to the mouth portion 13. A maxi cap 20 is attached to the open end of the mouth 13 by opening the tab 21 to open and open the scores 22a and 22b (see FIG. 4 (d)). As shown in detail in FIG. 6 together with FIG. 5, a bead portion 14 is formed in the mouth portion 13 by curling the tip portion outward. The specific structure of the maxi cap 20 is erected from the disc-shaped cap head portion 23a and the outer periphery of the cap head portion 23a in the same manner as the maxi cap of the small diameter (see FIG. 1), which is the general structure described above. A metal cap main body 23 composed of side portions 23b is provided, and a synthetic resin liner member 24 is fixed to the inner surface of the cap head portion 23a of the cap main body 23. A receiving portion 24a is formed on the peripheral portion of the liner member 24 to receive the bead portion 14 of the metal can 10 to ensure airtightness. The receiving portion 24a has a groove 24aa formed on the entire circumference thereof. Yes.

[0028] Then, the maxicap 20 is set in the mouth 13 of the metal can 10 so that the top of the bead part 14 faces the groove 24aa of the receiving part 24a of the liner member 24, and the side part 23b of the maxicap 20 is Fastened to the bead part 14 by fastening. For tightening the side part 23b to the bead part 14. As a result, the receiving portion 24a of the liner member 24 comes into close contact with the bead portion 14, thereby ensuring the airtightness of the metal can 10 with the maxi cap 20 clamped thereto.

Next, a method for forming the bead portion 14 described above will be described.

First, as shown in FIG. 7 (a), a first tool 201 having a ring-shaped predetermined curved surface is set at the tip end portion 13a of the mouth portion 13 of the metal can 10, and the first tool By lowering 201, the tip portion 13 a is bent along the curved surface of the first tool 201. Next, as shown in FIG. 7 (b), the second tool 202 having a ring-shaped curved surface that is shaped so as to further wind the tip portion 13a is set in the bent tip portion 13a of the mouth portion 13. Then, the second tool 202 is lowered. As a result, the bent distal end portion 13a is further wound, and the distal end abuts on the outer surface of the mouth portion 13 substantially perpendicularly. Then, by further lowering the second tool 202 in this state, the tip portion 13a in which the tip is in contact with the outer surface of the mouth portion 13 is stretched along the curved surface of the second tool 202. It is formed.

[0031] Finally, as described above, as shown in FIG. 8, the third tool 203 is set at the tip portion 13a of the mouth portion 13 where the tip end is in contact with the outer surface of the mouth portion 13 substantially perpendicularly. Is done. The third tool 203 has a curved surface that is shaped like a ring and applies pressure inward by a downward movement. By lowering the third tool 203 as described above, the upper end portion of the curled portion formed at the tip portion 13 a of the mouth portion 13 is inclined toward the inside of the metal can 10. As a result, a bead portion 14 is formed at the distal end portion of the mouth portion 13, and the upper end portion of the bead portion 14 is inclined inward by an angle a. Due to the inclination of the bead part 14, the inner diameter Din2 of the bead part 14 at the outward curl start position Pes of the bead part 14 is such that the curled tip 14a of the bead part 14 abuts the outer surface of the mouth part 13. Can inner diameter corresponding to the lower end is smaller than Dinl (see Fig. 6).

[0032] Since the upper end portion of the bead portion 14 formed at the tip end portion of the mouth portion 13 is inclined inward in this way, the width Lc of the bead portion 14 is made very large as shown in FIG. Even when the maxi cap 20 is set in the mouth portion 13 so that the inner surface of the side portion 23b contacts the outermost surface of the bead portion 14, the top portion of the bead portion 14 is formed on the inner surface of the maxi cap 20. It comes to face the groove 24aa of the receiving portion 24a of the liner member 24 (see the one-dot chain line portion in FIG. 9). In this state, when the side portion 23b of the maxi cap 20 is fastened to the bead portion 14, the top portion of the bead portion 14 is securely fitted into the groove 24aa of the receiving portion 24a of the liner member 24, as described above (see FIG. 6). ), The receiving portion 24a of the liner member 24 comes into close contact with the bead portion 14. In this way, even if the width Lc of the bead portion 14 is not particularly large, the top portion of the bead portion 14 can be received by the receiving portion 24a that is slightly offset in the center direction of the cap body 23. Adequate airtightness can be obtained even with a small-diameter maxicap 20 with a simple structure (see Figs. 1 and 6).

In the example shown in FIGS. 6 and 8, the bead portion 14 is bent at a predetermined position between the lower end force and the outward curl start position Pes. By bending at the lower end, the entire bead portion 14 is inclined inward.

Furthermore, as described above, a method for tightening the maxi cap 20 on the bead portion 14 formed at the distal end portion of the mouth portion 13 will be described.

[0035] The main part of the crimping machine used for the metal can 10 is configured as shown in FIG. This tightening machine has a generally cylindrical plunger 301, a sealing sleeve 302i, which is arranged so as to surround the outside of the plunger 301 and which has a tip divided into a plurality of parts (for example, 20 pieces). , 302j,..., And a compression sleeve 304 that constantly urges the plunger 301 downward. A receiving surface 301a that is a curved surface corresponding to the upper corner shape of the cap body 23 of the maxi cap 20 is formed on the lower end surface of the plunger 301 that is urged downward by the compression panel 304. Each sealing sleeve 302i (302j) is swingable in the radial direction of the maxi cap 20 disposed inside with the upper end as a fulcrum, and a sealing projection having a curved tip on the surface facing the maxi cap 20 302ia (30¾a) is formed. In addition, the opposite side of the surface of each sealing sleeve 302i (302j) where the sealing portion 302ia (302ja) is formed is an inclined surface 302ib (302jb), and the pushing that moves up and down outside each sealing sleeve 302i (302j). The front end of the sleeve 303 is in contact with the inclined surface 302ib (302jb).

[0036] The maxicap 20 is made of a metal by the tightening machine having such a structure as follows. It is attached to the tip of the mouth 13 of the can 10.

[0037] As shown in FIG. 10, the metal can 10 and the maxi cap 20 set at the front end of the mouth portion 13 so that the outer corner surface of the maxi cap 20 is along the receiving surface 301a of the plunger 301 Loaded into the fastening machine. When the tightening machine is operated in this state, as shown in FIG. 11 (a), the maxi cap 20 is pressed by the plunger 301 to form the groove of the receiving portion 24a of the liner member 24 formed on the inner surface of the cap body 23. The top part of the bead part 14 formed in the mouth part 13 of the metal can 10 is fitted into 24aa, and the liner member 24 is in close contact with the bead part 14. Then, the pushing sleeve 303 moves downward (Sa), and the tip thereof pushes the inclined surface 302ib (302jb) of each sealing sleeve 302i (302j) downward. Then, each sealing sleeve 302i (302j) swings toward the center of the maxicap 20 with the upper end as a fulcrum (Sb), and the sealing projection 302ia (302ja) covers the bead portion 14 on the side 2 of the cap body 23. Go to 3b.

[0038] Further, as the pushing sleeve 303 continues to move downward (Sa), each sealing sleeve 302i (302j) further swings in the central direction (Sb) of the maxicap 20 as shown in FIG. 11 (b). Each of the sealing protrusions 302ia (30¾a) presses the side portion 23b of the cap body 23 against the mouth portion 13 side of the metal can 10, and the side portion 23b of the cap body 23 is wound around the bead portion 14. Further, when the pushing sleeve 303 continues to move downward (Sa), as shown in FIG. 12, the maxi cap 20 of each sealing projection 302ia (302ja) due to the swinging of each sealing sleeve 302i (30¾) Due to the movement in the central direction (Sb), the maxi cap 20 having the side portion 23b sown by the bead portion 14 is pushed upward (Sc). As a result, the side portion 23b of the cap body 23 sandwiched between the receiving surface 30la of the plunger 301 and the sealing projection 302ia (302ja) urged downward by the compression panel 304 (see FIG. 10) becomes the bead portion 14. It can be tightened firmly. As a result, the maxi cap 20 is fastened to the bead portion 14 formed in the mouth portion 13 of the metal can 10 while the liner member 24 formed on the inner surface of the cap body 23 is firmly attached to the bead portion 14. It is fixed (see Fig. 6).

[0039] In the above-described tightening machine (see Figs. 10 to 12), the side portion 23b of the cap body 23 is determined by the urging force of the compression panel 304 and the height of the bead portion 14 that determines the push-up amount of the maxi cap 20. The tightening force to the bead part 14 is determined. And the bead part 14 is curled When the maxicap 20 is tightened (see FIGS. 11 (a), (b), and 12), the curled bead 14 is made of metal. Forces act in the center direction of can 10 (Sb in Figs. 11 (a), 11 (b) and 12) and its axial direction (the opposite direction of Sa in Figs. 11 (a), (b) and Fig. 12). However, since the tip of the curled bead 14 that contacts the outer surface of the mouth 13 becomes a resistance and can resist the force in the central direction, the axial force acts without being attenuated, The liner member 24 of the maxi cap 20 can be in a state of being firmly adhered to the bead portion 14. Thereby, the airtightness of the metal can 10 can be maintained relatively high. Further, as described above, the curled tip 14a of the bead portion 14 is in contact with the outer surface of the mouth portion 13 substantially perpendicularly (see FIGS. 8 and 9), so that the maxi cap 20 When tightening, the curled bead 14 is stretched at its tip 14a, and the tip of the bead 14 is more deformed by the force in the center direction and the axial direction of the metal can 10. You will be able to resist. As a result, a metal can 10 with higher airtightness can be realized.

[0040] In the above-described example, the curled tip of the bead portion 14 is in contact with the outer surface of the mouth portion 13 substantially perpendicularly, but the bead portion 14 is inclined inward (Fig. 8, Fig. 8). 9), the bead portion 14 may have a structure in which the tip portion is wound in the same manner as in the prior art (see FIG. 1).

[0041] Next, a metal can according to a second embodiment of the present invention will be described.

[0042] A metal can according to the second embodiment of the present invention is configured as shown in FIGS. FIG. 13 is a cross-sectional view showing the main part of the metal can according to the second embodiment of the present invention, and FIG. 14 is a cross-sectional view showing details of the bead part in the metal can shown in FIG. It is. Further, in FIGS. 13 and 14, the same parts as those shown in FIGS. 6 and 9 are denoted by the same reference numerals.

[0043] In the metal can 10 shown in Figs. 13 and 14, the outer corner 14aa of the curled tip 14a of the bead portion 14 hits the outer surface of the mouth portion 13, while the curled tip 14 of the bead portion 14 The inner corner 14ab has a structure that does not contact the outer surface of the mouth portion 13. With such a structure, the curled tip of the bead portion 14 comes into contact with the outer surface of the mouth portion 13 so that the outer corner 14aa abuts against the outer surface of the mouth portion 13. Against power Although the tip portion can resist deformation, the degree of tension of the tip portion with respect to the force in the center direction can be relaxed as compared to the case where the tip portion 14a hits the outer surface of the mouth portion 13 substantially vertically. As a result, when the maxi cap 20 is fastened to the bead portion 14, the lower end portion of the maxi cap 20 easily hits the lower portion of the bead portion 14, and the lower end of the maxi cap 20 fastened to the bead portion 14. Tightening of the part to the bead part 14 is suppressed. As a result, the maxi cap 20 fastened to the bead portion 14 can be removed (opened) relatively easily.

[0044] (Experimental example)

The inventor of the present invention has a conventional metal can as shown in FIG. 1 and a metal can 10 having the structure shown in FIGS. 13 and 14 (a metal can according to the second embodiment of the present invention). A drop airtightness evaluation test was conducted for and. The result is shown in FIG. In FIG. 15, the conventional can is a metal can having the structure shown in FIG. 1, and the improved can is a metal can 10 having the structure shown in FIGS.

[0045] The test method is that a metal can with a capacity of 100 ml is filled with water at a positive pressure, the maxi cap is clamped to the mouth, and the metal can is singly attached to an iron plate inclined at an angle of 10 degrees. Inverted fall (falling with the mouth down) was checked for airtightness (leakage) with or without decompression. Ten pieces were dropped from 20cm, 30cm, 40cm and 50cm height.

[0046] From the results shown in Fig. 15, the conventional can has a force that has been confirmed to be leaking from only 2 of 10 in the case of a 20cm high force drop Height exceeding that (30cm, 40cm, 50cm) In the case of force drop, leakage was confirmed from all 10 pieces. On the other hand, in the improved cans, no leaks were found in all 10 of the 20cm, 3Ocm, and 40cm height drops. In this improved can, only 3 out of 10 leaks were found when dropping as high as 50cm.

[0047] From this drop hermeticity evaluation test, the metal can 10 having the structure shown in FIG. 13 and FIG. 14 should maintain higher airtightness against dropping compared to the metal can having the conventional structure. I found that I could do it.

[0048] For the metal can having the structure shown in FIG. 6 (metal can according to the first embodiment of the present invention), the above-described drop airtightness evaluation test has not been performed. But the fall airtight The improved can (see Fig. 13 and Fig. 14) used for the property evaluation test shows that only the outer corner 14aa of the curled tip 14a of the bead portion 14 hits the outer surface of the mouth portion 13, and the stagnation of the bead portion 14 is somewhat In contrast to the permissible structure, both metal cans have the bead portion 14 bent as much as possible when the curled tip 14a of the bead portion 14 abuts the outer surface of the mouth portion 13 substantially vertically. Since it has a suppressed structure, it is presumed that the airtightness is superior to the improved can used in the drop airtightness evaluation test.

Industrial applicability

As described above, the metal can according to the present invention is sufficient even if a small-diameter maxi cap having a general structure in which a sealing property is ensured at a portion close to the center direction is sufficient. It is useful as a metal can with a maxi cap clamped and fixed to the mouth part following the trunk part.

Claims

The scope of the claims

[1] Torso force A metal can that is secured by tightening a cap that tears and opens the score by pulling a tab on a bead formed by curling the tip of the following mouth outward. And

The bead part is a metal can characterized by being inclined inward.

[2] The metal can according to [1], wherein an upper end portion of the bead portion is inclined inward.

[3] The metal can according to claim 1, wherein the inner diameter of the can at the position where the bead portion curls outward is smaller than the inner diameter of the can corresponding to the lower end portion of the bead portion.

4. The metal can according to claim 1, wherein the bead portion has a structure in which a curled tip portion is in contact with an outer surface of the mouth portion.

[5] The metal can according to [4], wherein the curled tip of the bead portion has a structure that abuts on the outer surface of the mouth portion substantially vertically.

6. The metal can according to claim 4, wherein the outer corner of the curled tip of the bead portion is in contact with the outer surface of the mouth portion.