JP2018193137A - Bottle can, bottle can with cap and production method of bottle can - Google Patents

Abstract

To provide a bottle can where sealability is ensured even when internal pressure of the can is high and heat sterilization is performed, boiling over at cap opening is hardly caused and the misrecognition of resealing is suppressed by improving the curled part shape of the bottle can.SOLUTION: In a bottle can, a curled part is provided at the opening end of a mouth part, the curled part is provided with an outer wall part extending downward from an upper edge curved part, the outer wall part is provided with a first curved part ranging downward from the upper edge curved part and forming a locking part in an outward projecting state, a second curved part ranging downward from the first curved part and being in an inward projecting state and a third curved part making the locking part as a first locking part and forming a second locking part at the lower side of the second curved part in an outward projecting state, and the third curved part is continued to the second curved part.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a bottle can, a bottle can with a cap, and a method for producing the bottle can.

  The bottle can is manufactured by drawing and ironing a metal plate made of aluminum or its alloy to obtain a bottomed cylindrical molded body, and then the neck is formed into a neck to process the shoulder. And mouth are formed. Further, a screw forming process is performed on the mouth part, and a curled part is formed at the opening end of the mouth part by a curl forming process.

  Various processed shapes have been proposed for the curl portion formed in the mouth portion of such a can in consideration of the sealing performance with the sealing material of the cap attached to the mouth portion.

  For example, in the prior art described in Patent Document 1 below, the outer surface side wall portion in which the curled portion formed by folding the periphery of the opening portion radially outward extends in a direction substantially parallel to the can axis direction of the bottle can. And an outer surface side curved portion extending radially inward from the upper end of the outer surface side wall portion, and an inner surface side convex curved portion further extending radially inward from the outer surface side curved portion, the outer surface side wall portion having a predetermined length or more. In addition, the connection part between the outer side wall part and the outer side convex curved part that are linearly formed by crushing is formed in a shape separated from the upper end (upper end of the mouth part) of the bottle can. Yes.

JP 2004-217305 A

  In the prior art described above, the connecting portion of the curled portion between the outer side wall portion and the outer curved portion is separated from the upper end of the bottle can. The sealing performance of the bottled can with the cap to which the cap provided with the material is attached is ensured.

  However, in this prior art, when the internal pressure of the bottle can with the cap filled with the contents is increased, the above-mentioned seal point is separated from the liner material due to the cap rising due to the pressure, and is substantially parallel to the axial direction of the can. Only the outer side wall extending in the direction comes into contact with the liner material. At this time, the contact length between the liner material and the outer side wall portion varies depending on conditions such as the filling temperature of the contents and the top load in the capping process. Therefore, sufficient sealing performance can be secured depending on these conditions. It may disappear. In particular, when heat sterilization is performed after filling the contents, according to the above-described conventional technology, the pressure inside the can increases during sterilization, which may reduce the sealing performance.

  In addition, in order to reduce the thickness of non-carbonated beverage cans with positive pressure, bottle caps with caps are generally filled with liquid nitrogen in the head space in the can, and the head space in the can is filled with nitrogen. Pressurized. If the bottled can with a cap filled with the contents is shaken as described above and the contents in the can become foamed, the foamed contents are easily blown out by the pressure in the can when the cap is opened. . In the prior art described above, since the internal pressure of the can is released to the atmosphere immediately after the cap is opened, there is a problem that the above-described problem of overflow is likely to occur.

  On the other hand, it is possible to reduce the above-described problem of overflow by making the liner material of the cap wrap around the can shaft side below the curled portion (undercut shape). However, if the undercut amount is increased in such an undercut shape, when the cap is once opened and resealed, the undercut portion of the liner material becomes resistance and the reseal torque increases, and reseal There is a problem that misrecognition of reseal that is not sufficiently resealed when it is felt that it has been completed is likely to occur. Misidentification of reseal is likely to cause an accident in which the bottled can with the contents left behind is left in a bowl or the like because it was resealed, and the inside of the bowl gets wet due to liquid leakage. Therefore, it is necessary to optimally control the undercut amount of the liner material. However, the undercut amount varies depending on the filling temperature of the contents, the capping conditions, and the like, and it is difficult to ensure stably.

  An object of the present invention is to deal with such a problem. That is, by improving the curl shape of the bottle can, it ensures high sealing performance even during high can internal pressure or heat sterilization, makes it difficult to cause overflow when the cap is opened, and prevents misidentification of reseal. That is the subject of the present invention.

In order to solve such a problem, the present invention has the following configuration.
A bottle can provided with a curled portion at an opening end of a mouth portion, wherein the curled portion includes an outer wall portion extending downward from an upper end curved portion, and the outer wall portion extends downward from the upper end curved portion and protrudes outwardly. A first bending portion that forms a locking portion, and a second bending portion that extends downward from the first bending portion and protrudes inward. The locking portion serves as a first locking portion, and the second A bottle can comprising: a third bending portion that forms a second locking portion with a convex outwardly below the bending portion, wherein the third bending portion is connected to the second bending portion.

  In the present invention having such a feature, by providing the first curved portion and the second curved portion on the outer wall portion of the curled portion of the bottle can, the undercut of the liner material is caught on the locking portion. High sealing performance can be ensured even during pressure or heat sterilization. Moreover, it is possible to make it difficult to cause overflow when the cap is opened by undercutting the liner material between the first curved portion and the second curved portion. In addition, the adjustment of the undercut amount by the first bending portion and the second bending portion can suppress an increase in reseal torque, thereby preventing misrecognition of reseal.

It is explanatory drawing which showed the whole structure of the bottle can which concerns on embodiment of this invention. It is explanatory drawing (sectional drawing) which showed the curl part of the bottle can which concerns on embodiment of this invention. It is explanatory drawing which showed the bottle can with a cap concerning embodiment of this invention. It is explanatory drawing (sectional drawing) which showed the curl part of the bottle can which concerns on other embodiment of this invention. It is explanatory drawing (sectional drawing) which showed the curl part of the bottle can which concerns on other embodiment of this invention. It is explanatory drawing which showed the example of the shaping | molding method of a curl part ((a) shows shaping | molding of a 1st step, (b) shows shaping | molding of a 2nd step). It is explanatory drawing ((a) is a front view and (b) is AA sectional drawing of (a)) which showed the structural example of the outer tool for shape | molding of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals in different drawings indicate parts having the same function, and repeated description in each drawing will be omitted as appropriate.

  As shown in FIG. 1, the bottle can 1 includes, for example, a bottom 1A, a trunk 1B, a shoulder 1C, and a mouth 1D. Such a bottle can 1 is formed by punching a metal plate made of an aluminum alloy into a circular shape, drawing it to obtain a bottomed cylindrical body, redrawing it, and ironing it to obtain a predetermined thickness. A cylindrical can is obtained once. Thereafter, by neck-in processing, the shoulder 1C and the mouth 1D are formed by reducing a predetermined length from the opening end of the cylindrical can. Then, the skirt portion 21 and the screw portion 22 are formed in the mouth portion 1D by spinning, and then the neck shoulder portion 20 inclined upward inward is formed above the screw portion 22 by neck-in processing. A curled portion 10 is formed at the opening end above 20.

  The curled portion 10 of the bottle can 1 according to the embodiment of the present invention has a cross-sectional shape as shown in FIG. The curled portion 10 includes an upper end curved portion 11 that curves outward from the neck shoulder portion 20, and further includes an outer wall portion 12 that extends downward from the upper end curved portion 11. The upper end bending portion 11 includes, for example, an inner bending portion 11A having a curvature radius Ra and an outer bending portion 11B having a curvature radius Rb.

  Then, the outer wall portion 12 continues downward from the upper end bending portion 11 and protrudes outwardly from the first bending portion 12A (curvature radius R1), and extends downward from the first bending portion 12A and protrudes inwardly from the second bending portion 12B ( Radius of curvature R2). In the illustrated example, the outer wall portion 12 includes an outwardly convex third curved portion 12C (curvature radius R3), an outwardly convex fourth curved portion in addition to the first curved portion 12A and the second curved portion 12B. 12D (curvature radius R4) is provided.

  According to such a bottle can 1, the outer wall portion 12 of the curled portion 10 includes the first curved portion 12 </ b> A that protrudes outward and the second curved portion 12 </ b> B that protrudes inward, so that the locking portion (first A locking part) is formed. Here, the locking portion refers to a form in which the lower part is narrower than the upper part of the outer surface of the object. The bottle can 1 having such a curled portion 10 includes the above-described locking portion (first locking portion), so that after capping, the liner material of the cap enters under the locking portion and undercuts ( 1st undercut) is formed and acts to catch the undercut on the locking part, so that the cap can be prevented from rising even when the pressure inside the can is high or during heat sterilization, ensuring high sealing performance. can do.

  In addition, the undercut described above ensures close contact between the undercut and the locking part even if the cap is lifted immediately after the cap is opened. It is also possible to suppress the phenomenon of overflowing.

  Furthermore, since the outer wall portion 12 of the curled portion 10 can regulate the undercut amount of the liner material due to the presence of the second curved portion 12B, the reseal torque can be reduced. As a result, it is possible to suppress an excessive increase in resistance at the time of resealing due to undercutting, and it is possible to prevent misidentification of resealing.

  Here, the bead depth (difference between the outermost portion of the first bending portion 12A and the innermost portion of the second bending portion 12B) t formed by the first bending portion 12A and the second bending portion 12B is 0.05 to. It is preferable to be about 0.2 mm. When the bead depth t is less than 0.05 mm, it becomes difficult to obtain the above-described undercut action, and therefore, the problem of deterioration in sealing performance at the time of heat sterilization and overflowing at the time of cap opening is likely to occur. Further, if the bead depth t exceeds 0.2 mm, a gap is likely to be generated between the liner material and the concave portion (bead) by the second curved portion 12B, and even if the bead depth t is further increased, an undercut occurs. The catching action due to is not increased.

  Thus, in order to obtain an appropriate bead depth t, the curvature radius R1 of the first bending portion 12A is set to 0.5 to 3 mm, and the curvature radius R2 of the second bending portion 12B is set to 0.5 to 2 mm. It is preferable.

  Further, since the seal point when the cap is attached is the upper end curved portion 11, in order to appropriately secure the amount of the upper end curved portion 11 that bites into the liner material at the seal point, the inner curved portion 11 </ b> A in the upper end curved portion 11. It is preferable that the curvature radius Ra is larger than the curvature radius Rb of the outer curved portion 11B (Ra> Rb), Ra is 0.5 to 2 mm, and Rb is 0.3 to 0.8 mm.

  When Rb is less than 0.3 mm, the upper end curved portion 11 bites into the liner material too much, and the riser material is likely to be damaged. When Rb is greater than 0.8 mm, the liner material of the upper end curved portion 11. The bite into the surface becomes small, making it difficult to obtain a desired sealing property at the seal point.

  In addition, the shape of the upper end curved portion 11 affects the deformation resistance at the time of a drop impact. When Ra is less than 0.5, the axial component increases at the time of the drop impact, and the curled portion 10 is deformed in the axial direction. Becomes larger. If Ra exceeds 2 mm, the amount of the upper-end curved portion 11 that bites into the liner material becomes small, so that it becomes difficult to obtain a desired sealing property at the seal point, and the angle of the neck shoulder portion 20 lies down, thereby buckling. The strength will decrease.

  Then, as shown in the example, in the case where the outer wall portion 12 of the curled portion 10 has the third bending portion 12C and the fourth bending portion 12D, a locking portion (first portion) is provided below the outermost portion of the third bending portion 12C. 2), the cap liner material is covered up to the second locking portion to form the second undercut, so that the sealing performance at the time of high internal pressure as described above is achieved. Can be further increased, and overflow when the cap is opened can be more reliably suppressed. In addition, since the first undercut and the second undercut are provided side by side to enhance the sealing performance, the amount of both undercuts can be suppressed, so the resistance during resealing can be reduced, and misrecognition of resealing is possible. It can prevent more reliably. The third bending portion 12C and the fourth bending portion 12D may be formed with different curvature radii R, or one curvature radius R. The curvature radius R3 of the third bending portion 12C and the fourth bending portion 12D It is preferable that the curvature radius R4 is set to 0.3 to 2 mm from the viewpoint of obtaining the effect of the second undercut as in the case of the first undercut described above.

  FIG. 3 shows a bottle can with a cap. The bottle can with the cap is provided with the cap 2 wound around the mouth portion 1D of the bottle can 1. The cap 2 includes a liner material 3 inside the top plate portion. In the illustrated example, the curled portion 10 of the bottle can 1 is provided with a first curved portion 12A, a second curved portion 12B, a third curved portion 12C, and a fourth curved portion 12D on the outer wall portion 12, and is a wound cap. Two liner materials 3 are attached so as to cover the first bending portion 12A, the second bending portion 12B, the third bending portion 12C, and the fourth bending portion 12D.

  FIG. 4 shows another embodiment of the curled portion 10. In this example, a flat surface portion 12F is provided between the second bending portion 12B and the third bending portion 12C in the outer wall portion 12. Also in this example, the first locking portion is formed in a portion from the first bending portion 12A to the second bending portion 12B, and the second locking portion is formed in the third bending portion 12C from below the flat surface portion 12F. Is formed. Providing such a flat surface portion 12F can also adjust the undercut amount of the liner material and suppress an increase in reseal torque.

  FIG. 5 shows a further different embodiment of the curled portion 10. In this example, the lower end inner edge 12P of the outer wall portion 12 is in line contact with the neck shoulder portion 20, and an open angle θt is provided between the lower end surface 12E of the outer wall portion 12 and the neck shoulder portion 20. For example, an angle of 10 ° to 70 ° is set as the angle θt.

  According to such an example, the lateral compression rigidity of the curled portion 10 is enhanced by the bead formed by the inwardly convex second curved portion 12B described above, whereby the deformation resistance due to the drop impact of the curled portion 10 can be enhanced. it can. In addition, when a lower end inner edge 12P of the outer wall portion 12 is brought into contact with the neck shoulder portion 20 and an open angle θt is provided between the lower end surface 12E of the outer wall portion 12 and the neck shoulder portion 20, a drop impact is applied. In addition, the curled portion 10 is easily deformed so as to fall outward, and the adhesion with the liner material can be maintained. The contact between the lower end inner edge 12P of the outer wall portion 12 and the neck shoulder portion 20 is preferably a line contact. Thereby, the sealing performance maintenance effect at the time of falling by falling after filling and capping of contents can be enhanced.

  With reference to FIGS. 6 and 7, a method of forming the curl portion in the bottle can manufacturing process will be described. The curled portion 10 is formed by reforming the curled portion shown in FIGS. 6 (a) and 6 (b) after the curled primary processing is performed on the opening end of the can body by spinning. In this reforming molding, the inner tool 30 is arranged inside the can, and the outer tool 40 arranged outside the can is pressed against the curled portion 10 to form the upper curved portion 11 and the outer wall portion 12 of the curled portion 10 into a desired shape. To do.

  At this time, in the first stage of the reform molding, as shown in FIG. 6A, an outer tool 40 (40A) having a flat surface 41 along the can axis is pressed against the curled portion 10, and the first stage is performed. In the second stage of remodeling, as shown in FIG. 6B, the outer tool 40 (40B) having the protrusions 42 is pressed against the curled portion 10, and the radius of curvature of the upper end curved portion 11 is set. At the same time, the first bending portion 12A and the second bending portion 12B (and the third bending portion 12C and the fourth bending portion 12D) in the outer wall portion 12 are formed.

  FIG. 7 shows a specific example of the outer tool 40. The outer tool 40 rotates around a rotation axis Os parallel to the can axis. In one rotation, the first stage molding shown in FIG. 6A is performed in the range of the first angle θ1 (for example, θ1 = 120 °), and the subsequent range of the second angle θ2 (for example, for example, The second stage molding shown in FIG. 6B is performed at θ2 = 120 °. By using such an outer tool 40, the curling part 10 can be efficiently formed without positioning the position of the bead.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the design can be changed without departing from the scope of the present invention. Is included in the present invention. In addition, the above-described embodiments can be combined by utilizing each other's technology as long as there is no particular contradiction or problem in the purpose and configuration.

1: bottle can, 1A: bottom, 1B: trunk, 1C: shoulder, 1D: mouth
10: Curled part,
11: upper end curved portion, 11A: inner curved portion, 11B: outer curved portion,
12: Outer wall portion, 12A: First curved portion, 12B: Second curved portion,
12C: 3rd bending part, 12D: 4th bending part, 12E: Lower end surface,
12F: plane part, 12P: lower end inner edge,
20: Neck shoulder part, 21: Skirt part, 22: Screw part,
30: Inner tool, 40 (40A, 40B): Outer tool,
41: flat surface, 42: protrusion

Claims (9)

A bottle can provided with a curled portion at the opening end of the mouth,
The curl portion includes an outer wall portion extending downward from the upper end curved portion,
The outer wall portion is
A first curved portion that forms a locking portion with an outward convex line extending downward from the upper-end curved portion; and a second curved portion with an inward convex shape that continues downward from the first curved portion; and A first locking portion, and a third bending portion that forms a second locking portion with an outward projection below the second bending portion,
The bottle can characterized in that the third bending portion is connected to the second bending portion.   The bottle can according to claim 1, wherein a bead depth formed by the first curved portion and the second curved portion is 0.05 to 0.2 mm.   The bottle can according to claim 1 or 2, wherein a radius of curvature of the first curved portion is 0.5 to 3 mm, and a radius of curvature of the second curved portion is 0.5 to 2 mm.   The said upper end curved part has an inner side curved part and an outer side curved part, The curvature radius of the said inner side curved part is larger than the curvature radius of the said outer side curved part, The Claim 1 characterized by the above-mentioned. The bottle can described.   The bottle can according to claim 4, wherein a radius of curvature of the inner curved portion is 0.5 to 2 mm, and a radius of curvature of the outer curved portion is 0.3 to 0.8 mm.   The bottle can according to any one of claims 1 to 5, wherein an open angle is provided between a lower end surface of the outer wall portion and the neck shoulder portion.   The bottle can according to claim 6, wherein an inner edge at a lower end of the outer wall portion is in contact with a neck shoulder portion.   The bottle can with a cap by which the cap provided with a liner material which forms an undercut so that a liner material covers the said latching | locking part in the bottle can of any one of Claims 1-7 was wound up. It is a manufacturing method of the bottle can according to any one of claims 1 to 7,
Press the outer tool rotating around the rotation axis parallel to the can axis against the curled part, and perform reforming of the curled part,
The outer tool presses the flat surface within the range of the first angle θ1 in one rotation to perform the first stage molding, and then in the direction perpendicular to the can axis within the range of the second angle θ2. A method of manufacturing a bottle can, characterized by pressing a protruding portion to protrude to perform a second stage molding.

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