JP4298402B2 - Bottle can, bottle with cap and method for producing bottle can - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a bottle can, a bottle can with a cap, and a method for manufacturing a bottle can, and in particular, provides a sealing property between a curled portion provided at an opening end of a base portion of a bottle can and a cap attached to the base portion. It relates to technology to improve.
[0002]
[Prior art]
In general, a bottle can widely used as a beverage can is formed by drawing a metal plate made of aluminum or its alloy and then performing an ironing process (Ironing). being called.
[0003]
In such a bottle can, the bottle can is formed from the metal plate, and the opening of the bottle can is reduced by a neck forming process to form a base part, and then the base part is screw-molded. As a result, a thread (male thread) portion and a fogged portion are formed, and further, curl forming processing is performed in which the opening end of the base portion is folded back from the inside to the outside, thereby forming a curled portion 5 as shown in FIG. For example, see Patent Document 1).
[0004]
The curled portion 5 has an opening wall 5a provided continuously to the base portion 2, an outer peripheral wall 5b provided by being folded back to the outside of the opening wall 5a, and a connecting portion 5c that couples the two 5a and 5b. ing. In the molding process of the curled part 5, a slot process is performed in which the outer peripheral wall 5 b is pressed inward in the radial direction of the base part 2 in order to secure an area of close contact with the sealing material of the cap described later on the outer peripheral wall 5 b.
In FIG. 6, reference numeral 1 is a bottle can, 2 is a cap portion, 3 is a screw (male screw) portion, and 4 is a fogged portion.
[0005]
Thereafter, when the bottle can 1 is filled with the contents, a cap 6 is attached to the cap portion 2 of the bottle can 1 as shown in FIG.
[0006]
As shown in FIG. 8, the cap 6 to be attached to the cap portion 2 of the bottle can 1 has a bottomed cylindrical shape, and a sealing material as a sealing material along the inside of the top surface portion 61. 67 is installed. The sealing material 67 is made of synthetic resin such as polyethylene having high heat resistance, EVA having high pressure resistance, and further ethylene propylene rubber (EPR). Reference numeral 62 is a knurl, 63 is a groove, 64 is a bead, 65 is a score, and 66 is a flare.
When this cap 6 is attached to the base part 2 of the bottle can 1, as shown in FIG. 7, the peripheral part of the sealing material 67 comes into contact with the curled part 5 of the base part 2, so that the sealing performance is good. It is supposed to be kept.
[0007]
Further, as a can different from the above, a can having a configuration in which the curl portion of the base portion is a multiple winding with two or more windings has been proposed (for example, see Patent Document 2).
[0008]
[Patent Document 1]
JP 2001-213417 A
[Patent Document 2]
Japanese Examined Patent Publication No. 62-42691
[0009]
[Problems to be solved by the invention]
By the way, in the bottle can 1 described in Patent Document 1, when the cap 6 is attached to the base portion 2, the sealing material 67 and the curled portion 5 are in close contact with each other to ensure sealing performance. When beer or carbonated drinking water not containing alcohol is filled as the contents, when the cap once opened is resealed, the adhesion between the sealing material 67 and the curled portion 5 is difficult to obtain as in the initial stage. Therefore, there is a problem that the taste of the contents is impaired. Therefore, in such a bottle can 1, higher sealing performance between the cap 6 and the base portion 2 has been demanded.
[0010]
Moreover, in this bottle can 1, since the curvature radius R of the front-end | tip outer periphery part shown in FIG. 6 becomes small about the curl part 5 of the nozzle | cap | die part 2, the torque at the time of resealing becomes large, and resealing is not made correctly. There was a problem.
That is, in the molding process of the curled part 5, as described above, the slot process is performed in which the outer peripheral wall 5b is pressed inward in the radial direction of the base part 2. At this time, the outer peripheral part of the tip of the curled part 5 projects sharply. Thus, the radius of curvature R of the outer periphery of the tip is reduced. And when resealing the cap 6 to this nozzle | cap | die part 2, when the outer-periphery edge part of the sealing material 67 shown in FIG. 7 is bend | folded below to a can axis direction, the end surface 67A of the outer-periphery edge part is shown in FIG. The curled portion 5 hits a sharply projecting portion and is locked to this portion. At this time, the resealing torque is increased, so that the consumer can be completely resealed, that is, the cap 6 is completely screwed to the base portion 2. There has been a problem that the content is leaked when it is misunderstood that the sealing performance of the content is ensured and the bottle can with the cap is subsequently carried.
[0011]
Further, in the can described in Patent Document 2, the wall portions forming the curled portion that is wound in multiple layers are in close contact with each other, and in particular, the inner curl wall is in close contact with the opening wall. The entire curl portion has a rigid structure. Therefore, when the cap is attached to the cap portion of the can, there is a problem that the curled portion is not easily adapted to the sealing material of the cap, and there is a problem that there is a limit in improving the sealing performance. Further, the curl portion of the can has a large space in the upper part in the curl portion because the wall portion located at the uppermost end and the tip of the inner curl wall are largely separated from each other. When the above-described slot processing is applied to the curled portion, the outer peripheral portion of the curled portion protrudes sharply when the space is pressed and crushed, and is described in Patent Document 1 above. Similarly, there is a problem that the radius of curvature R of the outer peripheral portion of the curled portion is formed small.
[0012]
The present invention has been made in consideration of such circumstances, and its purpose is to increase the rigidity of the curl portion of the base portion to improve the sealing performance between the cap and to reduce the reseal torque. It is providing the manufacturing method of the bottle can with a cap, the bottle can with a cap, and a bottle can.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present invention proposes the following means.
The invention according to claim 1 forms a curled part at the opening end of the base part, and when the cap is attached to the base part, the curled part and the sealing material attached to the cap are brought into close contact and sealed. In the bottle can, the curl portion is outside the opening wall of the base portion. Bent from the inside to the outside via the second connection part Outer curled wall and this outer curled wall Folded between the outer curl wall and the opening wall through the first connection portion inside Configured with an inner curled wall, The opening wall, the outer curl wall, and the inner curl wall are arranged substantially in parallel, and a gap is provided between the tip of the inner curl wall and the second connection portion. It is characterized by.
[0014]
According to the bottle can of the present invention, since the double curl portion including the outer curl wall and the inner curl wall disposed inside the cap portion of the bottle can is provided, the cap is covered on the cap portion. When worn, the outer curl wall and the inner curl wall of the curl part are pressed in the centripetal direction, The opening wall, the outer curl wall, and the inner curl wall are arranged substantially in parallel, and a gap is provided between the tip of the inner curl wall and the second connection portion. From the above, the curl portion can be improved in rigidity, while both the inner curl wall and the outer curl wall have their own elastic force acting in the outer peripheral direction, so that the curl portion is stronger than the cap sealing material. It is possible to improve the sealing performance between the cap sealing material and the curl portion of the base portion more reliably. Further, since the radius of curvature of the outer peripheral portion of the tip of the curled portion can be increased, it is possible to reduce the reseal torque when resealing the cap.
[0015]
The invention according to claim 2 is the bottle can according to claim 1, When the height dimension from the upper end of the second connection part to the lower end of the first connection part is a, and the height dimension from the upper end of the inner curl wall to the lower end of the first connection part is b, The relationship is 0.18 <b / a <0.86.
According to the bottle can according to the present invention, Height dimension from the upper end of the second connection part to the lower end of the first connection part a, Height dimension from the upper end of the inner curl wall to the lower end of the first connection part Since b has a relationship of 0.18 <b / a <0.86, the sealing performance between the cap sealing material and the curl portion of the cap portion can be more reliably improved.
[0016]
The invention according to claim 3 is the bottle can according to claim 1 or 2, wherein the double curled portion is provided with a flat portion on the outer curled wall, and a length L of the flat portion is 0.1 mm or more. It is said that it is said.
According to the bottle can according to the present invention, since the flat portion having the length L of 0.1 mm or more is formed on the outer periphery of the outer curl wall, when the cap is attached to the cap portion, the seal of the cap Since the contact area between the material and the flat part can be reliably increased, the sealing performance between the base part and the sealing material is further enhanced.
[0017]
The invention according to claim 4 is the bottle can according to any one of claims 1 to 3, wherein either the outer curl wall and the inner curl wall or between the inner curl wall and the opening wall. A clearance is formed on one or both sides, and the dimension of the clearance is in the range of 0.05 to 0.2 mm.
According to the bottle can according to the present invention, since the clearance is formed between the outer curl wall and the inner curl wall, and between the inner curl wall and the opening wall, the elastic restoring force can be obtained well, and the sealing performance is further improved. It can improve and can improve sealing performance.
[0018]
The invention according to claim 5 is characterized in that a cap is attached to the cap portion of the bottle can according to any one of claims 1 to 4.
According to the bottle can with a cap according to the present invention, by attaching the cap to the bottle can, the adhesion between the bottle can base and the cap is further increased, and therefore, carbonated drinking water not containing beer or alcohol, etc. If the content of the product is put in, it is possible to obtain a good sealing property even if the product is opened after being opened by the consumer, so that the taste of the content can be prevented from being impaired. High reliability as a bottle can with a cap that is repeated is obtained.
[0019]
According to a sixth aspect of the present invention, when the curled portion is formed at the opening end of the base portion and the cap is attached to the base portion, the curled portion and the sealing material attached to the cap are in close contact with each other. A method for manufacturing a bottle can in which sealing is performed, wherein when the curled portion is formed, an outer curled wall in which an opening wall of a base portion is folded outward, and a tip of the outer curled wall is connected to the outer curled wall and the opening. After forming the inner curl wall folded back with the wall, the outer curl wall, the inner curl wall, and the opening wall are joined together by pressing the outer curl wall inward in the radial direction of the base. It is characterized by crushing densely in the radial direction.
According to the bottle can manufacturing method of the present invention, the base part of the bottle can is formed in a state in which the outer curl wall, the inner curl wall, and the opening wall are crushed in the radial direction of the base part. Since the rigidity is increased and the inner curl wall is positioned between the outer curl wall and the opening wall, a bottle can having a large radius of curvature at the outer periphery of the tip of the curl part is obtained.
[0020]
The invention according to claim 7 is the bottle can manufacturing method according to claim 6, wherein either or both of the outer curl wall and the inner curl wall, or the inner curl wall and the opening wall are included. The pressing is performed so that a clearance is formed.
According to the bottle can manufacturing method of the present invention, the clearance is formed between one or both of the outer curl wall and the inner curl wall and between the inner curl wall and the opening wall. It is possible to obtain a bottle can which can obtain a good force, further improve the sealing performance and enhance the sealing performance.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are views showing a bottle can according to an embodiment of the present invention. FIG. 1 is an enlarged explanatory view of a main part showing a curled portion provided in a base part of the bottle can. FIG. It is an enlarged view of the principal part which shows the state by which the cap was attached to the bottle can.
The bottle can 1 of this embodiment shown in FIG. 1 is an enlarged portion of the base part 2, and a curl part 50 is provided in the base part 2. The curled portion 50 is formed as a double curled portion including an inner curled wall 51 provided outside the opening wall 5 a of the base portion 2 and an outer curled wall 52 provided outside the inner curled wall 51. ing.
[0022]
That is, the curled portion 50 is provided with an outer curled wall 52 that is bent from the inside to the outside substantially parallel to the opening wall 5a via the second connecting portion 54 on the outside of the opening wall 5a of the base portion 2. The inner curl wall 51 is formed on the inner side of the wall 52 through the first connection portion 53 so that the inner curl wall 51 is bent substantially in parallel, so that the inner curl wall 51 is provided on the outer side of the opening wall 5a. After the opening end of the portion 2 is folded from the inside to the outside to form the inner curled wall 51, the portion is further folded in the same manner to form the outer curled wall 52.
[0023]
In this case, the second connecting portion 54 connecting the outer curl wall 52 and the opening wall 5a is bent downward by having a predetermined radius of curvature, while the outer curl wall 52 and the inner curl wall 51 are connected to each other. The continuous first connecting portion 53 is also bent upward by having a predetermined radius of curvature, but neither of the first and second connecting portions 53, 54 is a single arc. Further, it may be formed so that arcs having a plurality of curvature radii are continuous. Such a curled portion 50 is formed with a slight separation between the inner curled wall 51 and the outer curled wall 52.
[0024]
Such a curled portion 50 has a double curled portion configuration having an inner curled wall 51 and an outer curled wall 52, while ensuring rigidity. On the other hand, as shown in FIG. When the cap 6 is attached, the cap 6 and the sealing material 67 attached to the cap 6 receive a tightening force inward of the base portion 2, so that the diameter of the cap 6 is reduced. The outer curl wall 52 is adapted to have an elastic restoring force acting in the outer circumferential direction as indicated by an arrow X.
[0025]
That is, when the cap 6 is attached to the base part 2, a large elastic restoring force is generated in the outer circumferential direction in the curled part 50 including the outer curled wall 52 and the inner curled wall 51, so that the sealing material 67 and the curled part are formed. Adhesion with 50 is strengthened, whereby the sealing performance between the two 67 and 50 is further enhanced. The chain line shown in FIG. 1 shows a state in which the curled portion 50 is reduced in diameter by the cap 6 being attached to the base portion 2.
Accordingly, when the cap 6 is attached to the base portion 2, the curled portion 50 strongly adheres to the sealing material 67 of the cap 6 by elastically restoring the outer curled wall 52 and the inner curled wall 51 in the outer circumferential direction. It is supposed to be.
[0026]
In the above configuration, the curled portion 50 has an average plate thickness t (unit: mm) in FIG. 1, a height dimension of the outer curled wall 52 a, and a height dimension of the inner curled wall 51 b in FIG. And when
2t ≦ b <a <10t, a−b ≧ t / 2
However, 0.1mm ≦ t ≦ 0.4mm
It is said that
[0027]
This is because if ab is smaller than t / 2, the tip of the inner curl wall 51 comes into contact with the connecting portion 54, and there is a risk that the connecting portion 54 will crack and the beverage will leak. Further, if b is smaller than 2t, the rigidity expected for the curled portion 50 cannot be secured. Further, if a is 10 t or more, the cap becomes large and the cost is increased, and the threading start position at the time of capping is lowered downward, so that the sealing performance is deteriorated.
Also, a and b described above are 0.18 <b / a <0.86, more preferably 0 so that the outer curl wall 52 and the inner curl wall 51 can obtain a good elastic restoring force in the outer circumferential direction. .65 <b / a <0.80.
[0028]
This is because if the length dimension b of the inner curl wall 51 is too short, not only the elastic restoring force of the inner curled wall 51 is difficult to act, but also the elastic restoring force of the outer curled wall 52 may not be exhibited. If the length dimension b of 51 is too long so as to extend to the bent portion of the outer curl wall 52, the outer curl wall 52 may be damaged and broken when the outer curl wall 52 is bent. Therefore, the inner curl wall 51 obtains its own elastic restoring force well, and the elastic curling force of the outer curl wall 52 can be exhibited well while accurately forming the outer curled wall 52. It is desirable to have a dimensional relationship.
[0029]
Further, a flat portion 55 that forms a flat surface is formed on the outer periphery of the outer curl wall 52 by slot processing. The length L of the flat portion 55 is set to 0.1 mm or more in order to ensure adhesion with the sealing material.
[0030]
In order to manufacture the bottle can 1 of this embodiment, a single metal plate made of aluminum or an alloy thereof is drawn and ironed to form a bottomed cylindrical bottle can, and the base is attached to the bottle can. After forming the part 2, the screw part 3 and the fogged part 4 as shown in FIG.
[0031]
Here, when forming the curled portion 50, first, as shown in FIG. 3A, the die 101 having the recess 100 is relatively moved with respect to the mouthpiece portion 2 of the bottle can, thereby leading the tip of the mouthpiece portion 2. The portion is guided along the recess 100, and an inner curl wall 51 and an outer curl 52 are formed outside the opening wall 5a as shown in FIG. Then, after the base part 2 is detached from the mold 101, the outer curl wall 52 is placed on the base part 2 by the roller 104 against the piece 103 arranged inside the base part 2 as shown in FIG. By pressing inward in the radial direction, the outer curl wall 52, the inner curl wall 51 and the opening wall 5a are densely crushed in the same radial direction (slot processing). By doing so, as shown in FIG. 4D, the outer curl wall 52, the inner curl wall 51, and the opening wall 5a closely approach each other, and these walls 52, 51, and 5a are substantially straight in cross section. It is formed in a shape.
[0032]
By forming the curled portion 50 in this way, the walls 52, 51, and 5a are closely and closely positioned, so that the rigidity of the curled portion 50 can be increased, and the opening wall 5a and the outer curled wall are provided. 1 between the connecting portion 54 and the outer curled wall 52 shown in FIG. 1, since the inner peripheral curled wall 51 exists between the connecting portion 54 and the outer curled wall 52 shown in FIG. The radius of curvature R can be made large.
[0033]
In the above processing, the pressing is performed so that a clearance is formed between one of or both of the outer curl wall 52 and the inner curl wall 51 and between the inner curl wall 51 and the opening wall 5a. . If a clearance of about 0.05 to 0.2 mm is formed between the outer curl wall 52 and the inner curl wall 51 and between the inner curl wall 51 and the opening wall 5a, the elastic restoring force is excellent. Thus, as will be described later, the curled portion 50 is adapted to the sealing material 67 of the cap 6 so that the sealing performance is further improved and the sealing performance can be improved. It is preferable to provide clearances between the outer curl wall 52 and the inner curl wall 51 and between the inner curl wall 51 and the opening wall 5a as described above. The structure which touches may be sufficient.
In the processing of the curled part 50, the radius of curvature R between the connecting part 54 and the outer curled wall 52 shown in FIG. 1 is 0.5 to 2.0 mm, preferably 0.7 to 1.0 mm. Is done.
In FIG. 2, reference numeral 8 indicates a shoulder portion (described later) provided on the cap 6.
[0034]
Since the bottle can 1 of this embodiment is configured as described above, the bottle can 1 is now formed from a single metal plate and the bottle can 1 is filled with a desired type of content. When the cap 6 is put on the base 2, as shown in FIG. 4, a cylindrical pressure block 71, and a pressure block insert 72 provided in the center of the pressure block 71 so as to be movable in the axial direction, The cap 6 is attached by the capping device 7 including the RO roller 73 and the PP roller 74, and the so-called bottle can 1 with a cap is formed.
[0035]
For example, as shown in FIG. 5A, the pressure block insert 72 presses and holds the top surface portion 61 of the cap 6 covered on the cap portion 2 of the bottle can 1 in the direction of the bottom of the can. Next, as shown in FIG. 5 (b), the pressure block 71 draws in the depth direction and the radial direction while pressing the outer peripheral side of the top surface portion 61 in the can bottom direction, so that a stepped portion is formed on the shoulder portion of the cap 6. 8 and the RO roller 73 rotates along the threaded portion 3 of the base portion 2 in this state, thereby forming a female screw around the cap 6 and the PP roller 74 rolls along the fogged portion 4. As a result, the flare 66 is wound and the cap 6 is attached.
[0036]
In the operation of attaching the cap 6, since the curled portion 50 of the base portion 2 is composed of a double curled portion, the rigidity of the curled portion 50 is increased, and drawing can be more strongly performed at the time of capping. Thus, high sealing performance is secured between the sealing material 67 of the cap 6 and the curled portion 50. Moreover, since the base part 2 is not deformed at the time of capping, the sealing performance is also improved from this point.
[0037]
Further, when the cap 6 is attached, when the pressure block 71 is drawn in the depth direction and the radial direction while pressing the outer peripheral side of the top surface portion 61 in the can bottom direction, the outer curl wall 52 and the inner curl wall 51 are correspondingly reduced. Is pressed in the centripetal direction as shown by the chain line in FIG. 1 or the solid line in FIG. 2, but the height dimension a of the outer curl wall and the height dimension b of the inner curl wall are as described above. , 0.18 <b / a <0.86, so that both the inner curl wall 51 and the outer curl wall 52 have their own elastic force and the arrow X shown in FIG. In this way, the elastic force acts in the outer peripheral direction, so that the curled portion 50 is strongly in close contact with the sealing material 67 of the cap 6, thereby obtaining a high sealing performance that prevents the contents from leaking.
[0038]
In this case, the elastic restoration is performed by forming a clearance of about 0.05 to 0.2 mm as described above between the outer curl wall 52 and the inner curl wall 51 and between the inner curl wall 51 and the opening wall 5a. A good force can be obtained, and the curled portion 50 can be adapted to the sealing material 67 of the cap 6 so that the sealing performance can be further improved and the sealing performance can be enhanced.
[0039]
As a result, when the cap 6 is attached to the base portion 2, the curled portion 50 is strongly brought into close contact with the sealing material 67 of the cap 6 by the elastic restoring force of the outer curled wall 52 and the inner curled wall 51. Of course, the leakage prevention effect can be enhanced, and the sealing performance between the sealing material 67 and the curled portion 50 can be more reliably enhanced.
[0040]
Further, since the curled portion 50 is configured such that the inner curled wall 51 exists between the opening wall 5a and the outer curled wall 52, the outer peripheral portion of the end of the curled portion 50 is excessively deformed even when slot processing is performed. Therefore, the radius of curvature R between the connection portion 54 and the outer curl wall 52 can be increased, and therefore, the peripheral end surface 67A of the sealing material 67 is connected to the connection portion 54 and the outer curl when the cap 6 is resealed. Without being locked with the wall 52, the reseal torque can be reduced when the cap 6 is resealed.
[0041]
Thereby, even if the cap 6 of the bottle can 1 filled with contents such as carbonated drinking water not containing beer or alcohol is closed again after opening, it is possible to prevent the taste and the like from being impaired, and Content leakage can be prevented. The sealing material 67 is sized along the top surface portion 61 when it is provided on the top surface portion 61 of the cap 6 before being deposited (see FIG. 8), but the cap 6 is capped on the base portion 2. By being attached by the device 7, the peripheral portion thereof is bent so as to cover the opening end of the base portion 2 as shown in FIG. 2 and FIG. 5 (b). In FIG. 5, reference numeral 75 denotes a spring that biases the pressure block insert 72 toward the bottom of the can.
[0042]
Further, in the curled part 50, since the flat part 55 is formed on the outer periphery of the outer curled wall 52, when the cap 6 is attached to the base part 2, the inner peripheral surface of the sealing material 67 of the cap 6 The contact area between the flat portions 55 can be increased, and the adhesion between the base portion 2 and the sealing material 67 is further enhanced.
[0043]
And since the sealing performance between the nozzle | cap | die part 2 of the bottle can 1 and the cap 6 increases further by attaching the cap 6 to the said bottle can 1, the reliability as a bottle can with a cap increases, therefore, for example, When contents such as carbonated drinking water that does not contain beer or alcohol are put in, even after being opened by a consumer, a good sealing property can be obtained, so the taste of the contents can be improved. It can also be prevented from being damaged.
[0044]
As the bottle can 1 described above, a curl portion having a dimension of t = 0.3 mm, a = 2.1 mm, and b = 1.5 mm is manufactured, and the bottle can be filled with contents and wrapped with a cap. When tightened, a good bottle can with no leakage and low reseal torque was obtained.
[0045]
In the illustrated embodiment, the bottomed cylindrical bottle can 1 is formed of a single metal plate, and the bottle can 1 is formed of aluminum or an alloy thereof. The same effect can be obtained by applying to a bottle can formed by using a metal plate of a material different from the above as well as a bottle can formed by integrally fixing a metal plate different from this to the bottom of the bottle can. Can do.
[0046]
【The invention's effect】
As described above, according to the first and second aspects of the invention, the double curl portion including the outer curl wall and the inner curl wall is provided in the mouthpiece portion of the bottle can, and the outer curl wall is provided. The height of the inner and inner curl walls is regulated so that the elastic restoring force can be exerted, so that it is possible to increase the rigidity of the curled part, while the outer curled wall can be strongly in close contact with the cap. As a result, the sealing performance between the sealing material of the cap and the curled portion of the cap portion can be improved more reliably, and the effect of enhancing the content leakage prevention effect can be obtained. In addition, since the radius of curvature of the outer periphery of the tip of the curled portion can be increased, the reseal torque can be reduced when the cap is resealed, and the effect of preventing leakage of the contents after reseal is obtained. .
[0047]
According to the invention of claim 3, since the flat portion is formed on the outer periphery of the outer curl wall, when the cap is attached to the base portion, the contact area between the sealing material of the cap and the flat portion is ensured. The effect of further increasing the sealing performance between the base part and the sealing material can be obtained.
According to the invention of claim 4, since the clearance is formed between the outer curl wall and the inner curl wall, and between the inner curl wall and the opening wall, the elastic restoring force can be obtained well, and the sealing performance is further improved. It can improve and can improve sealing performance.
[0048]
According to the invention of claim 5, the sealing performance between the cap portion of the bottle can and the cap is further enhanced. Therefore, when contents such as carbonated drinking water not containing beer or alcohol are put in, it is opened by the consumer. Even if it is closed after being plugged, a good sealing property can be obtained, so that the taste of the contents can be prevented from being impaired, and high reliability as a bottle can with a cap that is repeatedly opened Is obtained.
[0049]
According to the invention of claim 6, since the base part of the bottle can is formed in a state in which the outer curl wall, the inner curl wall, and the opening wall are crushed in the radial direction of the base part, the rigidity of the base part is increased. Since the inner curl wall is positioned between the outer curl wall and the opening wall, a bottle can having a large radius of curvature at the tip outer periphery of the curl portion is obtained, the sealing performance is good, and the reseal resistance can be reduced. A bottle can is obtained.
[0050]
According to the seventh aspect of the invention, since the clearance is formed between one or both of the outer curl wall and the inner curl wall and between the inner curl wall and the opening wall, the elastic restoring force of the curled portion is good. Thus, a bottle can that can be further improved in sealing performance and improved in sealing performance can be obtained.
[Brief description of the drawings]
FIG. 1 is an enlarged explanatory view showing a curled portion provided in a cap portion of a bottle can according to an embodiment of the present invention.
FIG. 2 is an enlarged explanatory view of a main part showing a state where a cap is attached to a bottle can.
FIGS. 3A to 3D are explanatory views showing a method for processing a curled portion of a bottle can.
FIG. 4 is a schematic view showing a capping device for attaching a cap to a bottle can.
FIG. 5 is a view when the capping device attaches a cap, where (a) is an explanatory view showing a state in which the cap is pressed against a bottle can, and (b) is a state in which the cap is wound around a base part. It is explanatory drawing which shows.
FIG. 6 is an explanatory view showing a curled portion provided in a base portion of a conventional bottle can.
FIG. 7 is an explanatory view showing a state in which a cap is attached to the cap portion of the bottle can.
FIG. 8 is a half sectional view showing a cap.
[Explanation of symbols]
1 bottle can
2 base part
50 curl
5a Open wall
51 inner curl wall
52 Outer curl wall
55 Flat part
6 Cap
67 Sealing material

Claims (7)

In the bottle can that forms a curled portion at the opening end of the base portion and seals the curled portion and the sealing material attached to the cap in close contact when the cap is attached to the base portion,
The curl portion is bent from the inside to the outside via a second connection portion outside the opening wall of the base portion, and the outer curl wall is located inside the outer curl wall via the first connection portion. And an inner curl wall folded between the opening wall and the opening wall, the outer curl wall and the inner curl wall are arranged substantially in parallel,
A bottle can characterized in that a gap is provided between a tip of the inner curl wall and the second connecting portion . The bottle can according to claim 1,
When the height dimension from the upper end of the second connection part to the lower end of the first connection part is a, and the height dimension from the upper end of the inner curl wall to the lower end of the first connection part is b,
0.18 <b / a <0.86
A bottle can characterized by that. In the bottle can according to claim 1 or 2,
The bottle can characterized in that the double curled portion is provided with a flat portion on the outer curled wall, and the flat portion L has a length of 0.1 mm or more. In the bottle can according to any one of claims 1 to 3,
A clearance is formed between one of or both of the outer curled wall and the inner curled wall, between the inner curled wall and the opening wall,
A bottle can characterized in that a dimension of the clearance is in a range of 0.05 to 0.2 mm. A bottle can with a cap, wherein the cap is attached to the base portion of the bottle can according to any one of claims 1 to 4. Manufacture of a bottle can in which a curled part is formed at the opening end of the base part, and when the cap is attached to the base part, the curled part and the sealing material attached to the cap are in close contact with each other to be sealed A method,
When forming the curled portion, an outer curled wall in which the opening wall of the base portion is folded outward and an inner curled wall in which the tip of the outer curled wall is folded back between the outer curled wall and the opened wall are formed. Then, the outer curl wall, the inner curl wall, and the opening wall are densely crushed in the same radial direction by pressing the outer curl wall radially inward of the base. A method for manufacturing cans. In the manufacturing method of the bottle can of Claim 6,
A bottle can characterized in that the pressing is performed so that a clearance is formed between one of or both of the outer curled wall and the inner curled wall and between the inner curled wall and the opening wall. Production method.

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